DE102015017515B4 - Tensioner drive for a seat belt device - Google Patents

Abstract

Tensioner drive (30) for a safety belt device with:
- a gas generator (40),
- a drive wheel (50) and
- a feed pipe (60) connecting the gas generator (40) and the drive wheel (50),
- wherein in the feed pipe (60) there are several thrust bodies (70, 71) which are accelerated after triggering of the gas generator (40) and drive the drive wheel (50),
- wherein at least one of the thrust bodies (71) completely or at least partially seals the feed pipe (60), and
- wherein the tensioner drive (30) is designed such that the sealing effect of the at least one sealing thrust body (71) is terminated or reduced with a time delay after the ignition of the gas generator (40), characterized in that
- the sealing thrust body (71) has at least one flow channel (110) which is closed by a closure element (500, 600, 700) before the ignition of the gas generator (40) and is released when the closure element (500, 600, 700) moves relative to the flow channel (110), in particular driven by the gas pressure of the gas generator (40) after the triggering of the gas generator (40),
- wherein the movement of the closure element (500, 600, 700) is braked by a fluid (540),
- wherein the fluid (540) is located in the sealing thrust body (71), namely - along the flow direction of the gas of the gas generator (40) and thus along the direction of movement (B) of the thrust bodies (70) in the feed pipe (60) - behind the closure element (500, 600, 700), and
- wherein the fluid (540) is pressed out of the thrust body (70) by the movement of the closure element (500, 600, 700) relative to the flow channel (110).

Description

The invention relates to a tensioner drive for a safety belt device.

Such a tensioner drive for a safety belt device is, for example, in the US patent US 6,345,504 B1 described. The previously known tensioner drive comprises a gas generator, a drive wheel, and a feed tube that connects the gas generator and the drive wheel. The feed tube contains several thrust bodies that are accelerated after the gas generator is triggered and drive the drive wheel, thereby tightening a seat belt of the seat belt device. The first thrust body in the feed tube, as seen from the gas generator, has a sealing effect and completely seals the feed tube on its own. With the previously known tensioner drive, the sealing thrust body is destroyed if the gas pressure within the feed tube in the section between the sealing thrust body and the gas generator becomes too great. If a predetermined gas pressure is not exceeded, the sealing thrust body permanently maintains its sealing effect against the feed tube.

Another tensioner drive for a safety belt device is known from the German published application DE 10 2009 051 451 A1 known.

The invention is based on the object of providing a tensioner drive which has improved operating behavior compared to the previously known tensioner drive.

This object is achieved according to the invention by a tensioner drive for a safety belt device comprising a gas generator, a drive wheel, and a feed tube connecting the gas generator and the drive wheel. The feed tube contains a plurality of thrust bodies that are accelerated after the gas generator is triggered and drive the drive wheel. At least one of the thrust bodies completely or at least partially seals the feed tube. The tensioner drive is configured such that the sealing effect of the at least one sealing thrust body is terminated or reduced with a time delay after the gas generator is ignited.

A key advantage of the tensioner drive according to the invention is that it ensures that, after the gas generator is started up, the pressure chamber between the thrust bodies and the gas generator is vented after a time delay has elapsed and a predetermined tensioning effect has been achieved. Pressure relief or venting of the pressure chamber is advantageous, for example, to enable a backward movement of the thrust bodies after the tensioning process has been completed.

Another significant advantage of the tensioner drive according to the invention is that, despite the provided venting, no hot gases from the gas generator can escape directly to the outside. The gas from the gas generator only escapes after it has passed through the leaking thrust body and all other thrust bodies behind it. Because the gas from the gas generator must flow around the previously sealed thrust body and the thrust bodies behind it, the gas loses a significant amount of temperature and pressure, so that the gas leak can no longer pose a significant hazard.

Gas can escape, for example, through the drive wheel or behind the drive wheel, so that the supply pipe can advantageously be designed without holes.

A hole-free design of the feed pipe is therefore considered advantageous.

It is considered particularly advantageous if the sealing thrust body has at least one flow channel which is closed before the gas generator is ignited, and the sealing thrust body has a delay device which, after the gas generator is triggered, releases the flow channel itself with a time delay or causes it to be released.

According to a first particularly preferred embodiment of the tensioner drive, it is provided that the delay device has a pyrotechnic charge or is formed by such a charge, which is ignited after the triggering of the gas generator and actively releases the flow channel itself with a time delay or actively causes the release of the flow channel itself.

It is advantageous if the pyrotechnic charge closes the flow channel before the gas generator is ignited and releases the flow channel by material conversion during or after the pyrotechnic material of the pyrotechnic charge has burned out.

Alternatively, it can be provided that the pyrotechnic charge destroys or moves away a closure element closing the flow channel during or after the combustion of the pyrotechnic material and thereby triggers the release of the flow channel.

With regard to the pyrotechnic charge, it is considered advantageous if it comprises one or more tablets of pyrotechnic material or is formed by one or more such tablets.

It is advantageous if at least one of the tablets or all of the tablets are placed in front of or in the flow channel and serve as the or at least one of the closure elements for closing the flow channel.

The tablets are preferably enclosed, either together or individually, in a water vapor-tight protective sheath, particularly if the pyrotechnic material is hygroscopic. The film thickness is preferably between 0.01 and 0.5 mm.

It is also advantageous if at least one of the tablets is held in a retaining plate and placed together with it in front of or in the flow channel, forming the closure element or at least one of the closure elements. A retaining plate can be used, for example, to compensate for size differences between the tablet and the inner diameter of the flow channel.

With a view to a simple but precise specification of the time delay for the release of the flow channel after ignition of the gas generator, it is considered advantageous if two or more tablets are arranged in a cascaded manner in the flow channel, viewed in the direction of gas flow, and are ignited one after the other or in a cascaded manner. The time delay for the opening of the flow channel after ignition of the gas generator is determined or at least influenced by the time delay of the cascade ignition of the tablets. By changing the number of cascaded tablets and selecting the tablet material, the time delay for the release of the flow channel can be set virtually arbitrarily and yet very precisely.

• - zumindest ein Zeitverzögerungselement vor der Tablette oder im Falle mehrerer Tabletten - in Gasströmrichtung des Gasgenerators gesehen - vor der ersten Tablette angeordnet ist und/oder
• - zumindest ein Zeitverzögerungselement zwischen zwei benachbarten Tabletten angeordnet ist und/oder
• - zumindest ein Zeitverzögerungselement - in Gasströmrichtung des Gasgenerators gesehen - hinter der Tablette oder im Falle mehrerer Tabletten hinter der letzten Tablette angeordnet ist.

A further delay can advantageously be achieved by providing additional time delay elements. Regarding the arrangement of such time delay elements, it is considered advantageous if

• - at least one time delay element is arranged in front of the tablet or, in the case of several tablets - seen in the gas flow direction of the gas generator - in front of the first tablet and/or
• - at least one time delay element is arranged between two adjacent tablets and/or
• - at least one time delay element is arranged behind the tablet or, in the case of several tablets, behind the last tablet, as seen in the gas flow direction of the gas generator.

The time delay element, the time delay elements or at least one of the time delay elements is preferably formed by a film element, in particular a film element made of plastic film.

The film elements are preferably made of plastic film with a thickness between 0.01 mm and 0.5 mm.

According to a second particularly preferred embodiment of the tensioner drive, it is provided that the flow channel is closed by a closure element before the ignition of the gas generator and the tensioner drive has a delay device which, after the triggering of the gas generator, moves the closure element away with a time delay and thereby triggers the release of the flow channel.

It is particularly advantageous if the closure element is a displaceable valve piston, in particular one which is displaceable linearly or translationally along its longitudinal direction, which closes the flow channel in a first piston position before the ignition of the gas generator and opens the flow channel in a second position displaced relative to the first piston position.

It is particularly advantageous if the delay device is a pressure build-up delay device which is arranged upstream of the valve piston and allows the pressure prevailing in the supply pipe after ignition of the gas generator to act on the valve piston only with a time delay.

Preferably, the delay device comprises a pre-chamber which is connected to the supply pipe via at least one inflow opening, wherein the gas of the gas generator flows into the pre-chamber through the at least one inflow opening after the ignition of the gas generator and causes a time-delayed pressure build-up in the pre-chamber.

It is particularly advantageous if the displaceable valve piston is arranged in the prechamber, closes the flow channel in a first piston position before the ignition of the gas generator and opens the flow channel in a second position displaced relative to the first piston position, the piston being moved from the first to the second position when a predetermined pressure is reached in the prechamber.

The flow channel is preferably arranged inside the thrust body, and the closure element seals the thrust body. Alternatively, the flow channel can be arranged on the outer edge of the thrust body, and the closure element seals the thrust body together with the pipe wall of the supply pipe. Of course, both types of flow channels can also be provided.

With a view to a particularly simple, yet very precise adjustment of the time delay between the ignition of the gas generator and the leakage of the thrust body, a thrust body design is also considered advantageous in which the movement of a movable closure element within the sealing thrust body is braked by a fluid.

A configuration is considered to be particularly advantageous which is characterized in that the sealing thrust body has at least one flow channel which is closed by a closure element before the ignition of the gas generator and is only released when the closure element moves relative to the flow channel, in particular driven by the gas pressure of the gas generator after the triggering of the gas generator, wherein the movement of the closure element is braked by a fluid.

The flow channel can be straight or curved.

If the release of the thrust body is to be delayed by the closure element, it is considered advantageous if the flow channel forms a labyrinth, thereby increasing the fluid path length.

It is also advantageous if the flow channel is provided with a filter, in particular a sintered filter, for example to slow down the fluid flow and thereby delay the release by the closure element.

Preferably, the fluid is located in the thrust body, specifically—as seen along the flow direction of the gas from the gas generator and thus along the direction of movement of the thrust bodies in the supply pipe—behind the closure element. The fluid is preferably forced out of the thrust body by the movement of the closure element relative to the flow channel, thereby slowing the movement of the closure element relative to the flow channel.

The aforementioned timing control by means of an upstream fluid can be implemented in a particularly advantageous manner if, viewed along the flow direction of the gas from the gas generator, there is a receiving space in the thrust body behind the closure element, into which the closure element is pressed by the gas pressure of the gas generator as it moves relative to the flow channel. The fluid is preferably located in this receiving space before the gas generator is triggered and, after the gas generator is triggered, is pressed out of the receiving space by the closure element penetrating into the receiving space and out of the thrust body through at least one outflow channel connected to the receiving space.

The time period that should elapse after the ignition of the gas generator before the thrust body becomes leaky can be easily and advantageously influenced by the diameter or cross-section of the outflow channel, the length of the outflow channel, the viscosity of the fluid, the diameter (or cross-section) of the receiving space, the diameter (or cross-section) of the closure element, the volume of the receiving space, the volume of the fluid and the gas pressure of the gas generator and can be adjusted almost arbitrarily by selecting these parameters.

In order to avoid unwanted leakage of the fluid before the gas generator is triggered, it is considered advantageous if the outflow channel is closed to the outside by a sealing element in the initial state, i.e. before the gas generator is triggered, and the fluid is locked in the receiving space.

Alternatively or additionally, the liquid can be enclosed in a film sleeve, forming a fluid sac. The film sleeve is preferably only destroyed or torn open by the pressure of the closure element moving toward the fluid sac. An advantage of this design is simplified assembly of the thrust body, because only a prefabricated fluid sac needs to be inserted into the receiving space.

In order to achieve the longest possible delay between the ignition of the gas generator and the leakage of the thrust body, it is considered advantageous if the cross-section of the outflow channel is smaller than the cross-section of the receiving space.

A particularly long time delay between the ignition of the gas generator and the leakage of the thrust body can be achieved if the leakage of the fluid occurs at least also requires a fluid flow against the direction of movement of the closure element.

Such a reversal of movement of the fluid flow relative to the direction of movement of the closure element can be achieved particularly easily and thus advantageously if the closure element and the receiving space are shaped in such a way that complementary to one another that when the closure element penetrates into the receiving space, a fluid channel delimited by the closure element and the receiving space is formed in the interior of the receiving space, in which fluid channel the fluid must flow against the flow direction of the gas of the gas generator and thus against the direction of movement of the closure element.

With regard to the realization of the aforementioned complementary shape of the closure element and the receiving space, it is considered advantageous if the closure element is at least partially cup-shaped, with a cup bottom of the closure element facing the gas generator and a cup wall extending away from the cup bottom and the gas generator, and the receiving space having an elevation extending in the direction of the closure element and in the direction of the gas generator, for example in the form of a projection. During movement of the closure element, the cup wall is preferably pressed into the receiving space and thereby folded over the elevation, whereby a fluid channel is formed between the cup wall and the elevation, in which the fluid flows counter to the direction of movement of the closure element.

Preferably, an outflow channel is arranged in the elevation, which is fluidly connected to the fluid channel and allows the fluid to flow out of the thrust body along the direction of movement of the closure element.

The flow channel can be opened by the thrust body by moving the closure element out of the flow channel entirely or at least partially. Alternatively, the closure element can have a through-opening that is offset from the flow channel before the gas generator is ignited and is only brought into overlap with the flow channel by a movement of the closure element relative to the flow channel, enabling gas flow through the closure element and the flow channel.

The fluid is preferably a liquid. A silicone fluid or a fluid containing at least silicone is considered particularly suitable.

The viscosity of the liquid is preferably between 100,000 and 4,000,000 cSt.

With a view to ensuring the safe functioning of the tensioner drive, it is considered particularly advantageous if the fluid has a viscosity whose change in temperature range between -40°C and 95°C is less than 1000%.

• 1 ein Ausführungsbeispiel für einen erfindungsgemäßen Strafferantrieb, der in einem Ausführungsbeispiel für einen erfindungsgemäßen Gurtaufroller eingesetzt ist,
• 2-3 ein erstes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 4 ein zweites Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 5 ein drittes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 6 ein viertes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 7 ein fünftes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 8 ein sechstes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 9 ein siebentes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 10 ein achtes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 11 ein neuntes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 12 ein zehntes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 13 ein elftes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 14 ein zwölftes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 15 ein dreizehntes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 16 ein vierzehntes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 17-20 ein fünfzehntes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 21-22 ein sechzehntes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 23-25 ein siebzehntes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 26-27 ein achtzehntes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1,
• 28-30 beispielhaft das Einfüllen eines Fluids in einen Schubkörper anhand des fünfzehnten Ausführungsbeispiels und
• 31 ein neunzehntes Ausführungsbeispiel für einen Antriebskolben für den Strafferantrieb gemäß 1.

The invention is explained in more detail below using exemplary embodiments; by way of example,

• 1 an embodiment of a tensioner drive according to the invention, which is used in an embodiment of a belt retractor according to the invention,
• 2-3 a first embodiment of a drive piston for the tensioner drive according to 1 ,
• 4 a second embodiment of a drive piston for the tensioner drive according to 1 ,
• 5 a third embodiment of a drive piston for the tensioner drive according to 1 ,
• 6 a fourth embodiment of a drive piston for the tensioner drive according to 1 ,
• 7 a fifth embodiment of a drive piston for the tensioner drive according to 1 ,
• 8 a sixth embodiment of a drive piston for the tensioner drive according to 1 ,
• 9 a seventh embodiment of a drive piston for the tensioner drive according to 1 ,
• 10 an eighth embodiment of a drive piston for the tensioner drive according to 1 ,
• 11 a ninth embodiment of a drive piston for the tensioner drive according to 1 ,
• 12 a tenth embodiment of a drive piston for the tensioner drive according to 1 ,
• 13 an eleventh embodiment of a drive piston for the tensioner drive according to 1 ,
• 14 a twelfth embodiment of a drive piston for the tensioner drive according to 1 ,
• 15 a thirteenth embodiment of a drive piston for the tensioner drive according to 1 ,
• 16 a fourteenth embodiment of a drive piston for the tensioner drive according to 1 ,
• 17-20 a fifteenth embodiment of a drive piston for the tensioner drive according to 1 ,
• 21-22 a sixteenth embodiment of a drive piston for the tensioner drive according to 1 ,
• 23-25 a seventeenth embodiment of a drive piston for the tensioner drive according to 1 ,
• 26-27 an eighteenth embodiment of a drive piston for the tensioner drive according to 1 ,
• 28-30 by way of example, the filling of a fluid into a thrust body using the fifteenth embodiment and
• 31 a nineteenth embodiment of a drive piston for the tensioner drive according to 1 .

For the sake of clarity, the same reference symbols are always used in the figures for identical or comparable components.

In the 1 shows a schematic exploded view of an embodiment of a belt retractor 10. The belt retractor 10 has, among other things, a belt spindle 20, a tensioner drive 30 and an inertia coupling 35 connecting the tensioner drive 30 and the belt spindle 20.

The tensioner drive 30 comprises a pyrotechnic gas generator 40, for example in the form of a micro gas generator, a drive wheel 50, a curved supply tube 60 connecting the gas generator 40 and the drive wheel 50, a plurality of mass or thrust bodies 70, and a thrust body in the form of a drive piston 71, which forms the first thrust body in the thrust body chain - viewed from the gas generator 40. The thrust bodies 70 are, for example, spherical and do not form a seal with respect to the supply tube 60 and are pushed by the drive piston 71 after the gas generator 40 is triggered. The drive piston 71 initially seals the supply tube 60, but becomes leaky after a certain period of time after the gas generator 40 is ignited, so that the gas G from the gas generator 40 can flow past the thrust bodies 70.

A spring 75 may be arranged between the gas generator 40 and the drive piston 71.

The drive wheel 50 is rotatably mounted between a retaining cap 51 and a retaining plate 52 and has receiving pockets in the form of receiving shells 80, into which the thrust bodies 70 engage to drive the drive wheel. For this purpose, the thrust bodies 70 are coupled tangentially into the drive wheel 50 and run tangentially past it, engaging in the receiving shells 80, before subsequently reaching a downstream receiving container 81.

The 2 shows a first embodiment of a drive piston 71 which is used in the tensioner drive 30 of the belt retractor 10 according to 1 can be used. The drive piston 71 has a seal 100 that seals the drive piston 71 against the inner wall of the feed pipe 60. A front section 105 of the drive piston 71 drives the thrust bodies 70 located in front of it along the gas flow direction G.

The drive piston 71 is equipped with a flow channel 110, which would allow gas to flow through the drive piston 71 if it were not closed by a pyrotechnic charge 115. The pyrotechnic charge 115 thus forms a closure element that closes the flow channel 110 in the initial state of the tensioner drive 30, i.e., before the ignition of the gas generator 40.

If the gas generator 40 is triggered, hot gases from the gas generator 40 and/or particles, in particular metal particles, of the ignition charge and/or the pyrotechnic drive of the gas generator 40 will impact the drive piston 71 and the pyrotechnic charge 115, resulting in the igniting of the pyrotechnic charge 115. After the igniting of the pyrotechnic charge 115, it will burn and, due to material transformation, lose its sealing effect within the flow channel 110. After a time delay predetermined by the dimensioning or design of the pyrotechnic charge 115—relative to the triggering time of the gas generator 40—the pyrotechnic charge 115 will thus actively lose its sealing effect and open the flow channel 110.

The 3 shows the state of the drive piston 71 after the pyrotechnic charge 115 has been 2 disappeared due to burning and the flow channel 110 is open. The gas stream G can flow through the flow channel 110 through the drive piston 71 and into the area of the supply pipe behind the drive piston 71.

The 4 shows a second embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 In the second embodiment according to 4 A tablet 150 forms a pyrotechnic charge that closes a flow channel 110 of the drive piston 71 in the initial state. The tablet 150 rests on a step 155 within the flow channel 110.

The tablet 150 preferably consists of an early ignition material; the term “early ignition material” is understood here to mean pyrotechnic material having an ignition temperature below 200°C.

As soon as after ignition of the gas generator 40 according to 1 If hot gases hit the tablet 150, it will self-ignite and, due to material transformation, lose its sealing property within the flow channel 110. The flow channel 110 is opened, and a gas flow G through the drive piston 71 becomes possible, as described in connection with the 2 and 3 has already been explained in more detail above using the first exemplary embodiment.

The 5 shows a third embodiment of a drive piston 71, which in the tensioner drive 30 according to 1 can be used. The drive piston 71 has a flow channel 110 in which two tablets 150 and 160 made of pyrotechnic material are arranged and seal the flow channel 110. One of the two tablets, namely tablet 150, rests on a step 155 of the flow channel 110. The two tablets 150 and 160 are preferably made of an early ignition material, i.e., a pyrotechnic material with an ignition temperature below 200°C.

As soon as the gas generator 40 has been ignited, hot gas and/or hot particles from the gas generator 40 will first ignite the tablet 160, which in turn will subsequently ignite the tablet 150, so that the cascaded combustion of the pyrotechnic material of the two tablets 150 and 160 leads to a delayed opening of the flow channel 110 - compared to the ignition time of the gas generator 40 - and the flow channel 110 is opened.

The 6 shows a fourth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 can be used. The drive piston 71 is equipped with a flow channel 110 in which two tablets 150 and 160 made of an early ignition material and one tablet 170 made of a propellant material are arranged. A propellant material is understood here to be a pyrotechnic material that has an ignition temperature of at least 280°C.

As can be seen in the 6 As can be seen, the tablet 170 made of propellant material is smaller than the two tablets 150 and 160. For this reason, the tablet 170 is held in a through-opening of a retaining panel 175. The retaining panel 175 can be made of metal or plastic; however, the retaining panel 175 is preferably a plastic panel. The inner diameter of the aperture of the retaining panel 175, or the diameter of the tablet 170 held therein, is preferably between 1 and 3 mm. The thickness of the retaining panel 175 is preferably between 0.5 and 3 mm.

In the initial state of the drive piston 71, the flow channel 110 is sealed gas-tight by the three tablets 150, 160 and 170. If the gas generator 40 of the tensioner drive 30 is 1 ignited, its hot gas and/or hot particles of the ignition and/or propellant charge of the gas generator 40 will first ignite the first tablet 170 arranged in the tablet cascade, which in turn subsequently ignites the two further tablets 150 and 160 in a cascaded manner with a time delay, whereby the flow channel 110 opens due to the cascaded combustion of the three tablets 150, 160 and 170, so that the gas of the gas generator 40 can subsequently pass through the drive piston 71.

The 7 shows a fifth embodiment of a drive piston 71, which in the tensioner drive 30 according to 1 The drive piston 71 is equipped with two tablets 150 and 160, which correspond to the tablets 150 and 160 according to the 4 to 6 In other words, tablets 150 and 160 are preferably tablets made of an early ignition material.

In the embodiment according to 7 In addition to the two tablets 150 and 160, a total of four time delay elements 200 are provided, two of which are located between the two tablets 150 and 160 and two in the gas flow direction G in front of the 7 left or first tablet 160 as seen in the gas flow direction G.

The time delay elements 200 are preferably made of foil material, preferably of plastic foil material. The function of the time delay elements 200 is, after ignition of the gas generator 40 according to 1 to delay the subsequent ignition of the two tablets 150 and 160 and thus to extend the time offset between the ignition of the gas generator 40 on the one hand and the opening of the flow channel 110 on the other hand.

As soon as the tablets 150 and 160 ignite and burn, the time delay elements 200 will also be destroyed, so that the flow channel 110 is opened and a gas flow G is allowed through the drive piston 71.

The time-delay elements are preferably formed from film, preferably plastic film. The thickness of the film is preferably between 0.01 mm and 0.5 mm. The plastic film is particularly preferably made of PD-LD film.

The 8 shows a sixth embodiment of a drive piston 71, which in the tensioner drive 30 according to 1 can be used. The drive piston 71 has two tablets 150 and 160, which are preferably made of pre-ignition material. In addition, the drive piston 71 is equipped with six time delay elements 200, three of which are arranged between the two tablets 150 and 160 and three in front of the tablet 160 as seen in the gas flow direction G. The function of the six time delay elements 200 is to delay the ignition of the two tablets 150 and 160 after the triggering of the gas generator 40, as is the case in connection with the 7 has already been explained above. The above statements in connection with the 7 apply accordingly here.

The 9 shows a seventh embodiment of a drive piston 71 for the tensioner drive 30 according to 1 The seventh embodiment according to 9 corresponds to the sixth embodiment according to 8 with the difference that not six time delay elements, but eight time delay elements are provided, four of which are arranged between the two tablets 150 and 160 and four in front of the tablet 160 as seen in the gas flow direction G.

Due to the higher number of time delay elements 200, the design variant according to 9 a greater time delay between the ignition of the tablets 150 and 160 after the triggering of the gas generator 40 is achieved than in the embodiment according to 8 . Furthermore, the above statements apply in connection with the 7 and 8 in the embodiment according to 9 accordingly.

The 10 shows an eighth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 The eighth embodiment according to 10 corresponds to the fourth embodiment according to 6 with the difference that two additional time delay elements 200 are provided, which are intended to cause a time delay in the ignition of the two tablets 150 and 160, as has already been exemplified in connection with the 7 to 9 The delay elements 200 are preferably made of a plastic film material. Furthermore, reference is made to the above explanations in connection with the 4 to 9 which apply here accordingly.

The 11 shows a ninth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 can be used. In a flow channel 110 of the drive piston 71, two tablets 150 and 160, which preferably consist of an early ignition material, and two tablets 170 and 180, which preferably consist of a propellant material, are located to seal the flow channel in the initial state.

The two tablets 170 and 180 are smaller than the tablets 150 and 160, so that they are each held in a holding panel 175 and 185. The two holding panels 175 and 185 are preferably made of plastic material.

In order to effect a further time delay of the cascaded ignition of the tablets 150, 160, 170 and 180 after triggering of the gas generator 40, a total of five time delay elements 200 are provided, two of which are provided between the two tablets 170 and 180, two between the two tablets 160 and 170 and one between the two tablets 150 and 160. Regarding the functioning of the two tablets 150 and 160, the two tablets 170 and 180 and the time delay elements 200, reference is made to the above embodiments in connection with the 4 to 10 which apply here accordingly.

The 12 shows a tenth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 The tenth embodiment according to 12 The structure corresponds to the ninth embodiment according to 11 with the sub differs in that a larger number of time delay elements 200 are provided. Thus, it can be seen that a single time delay element 200 is provided between the two tablets 150 and 160, which preferably consist of pre-ignition material. Between the tablet 160 and the tablet 170, which is closest in the gas flow direction G and which preferably consists of propellant material, two time delay elements are preferably provided. Between the tablet 170 and the tablet 180 in front of it, which preferably also consists of propellant material, three time delay elements 200 are provided. Regarding the functioning of the time delay elements 200 and the tablets 150, 160, 170 and 180, reference is made to the above explanations in connection with the 4 to 11 referred to.

The 13 shows an eleventh embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 can be used. Located in a flow channel 110 of the drive piston 71 are two tablets 150 and 160, which preferably consist of an advance ignition material, and one tablet 170, which preferably consists of a propellant material. The tablet 170 is held in a retaining cover 175, which is preferably made of plastic.

In order to make the time delay between the ignition of the gas generator 40 and the opening of the flow channel 110 as long as possible, a plurality of time delay elements 200 are provided. 13 three time delay elements 200 between the two tablets 150 and 160, three time delay elements 200 between the tablets 160 and 170 and a further time delay element 200 arranged in front of the tablet 170.

Regarding the functioning of the drive piston 71, reference is made to the above explanations in connection with the 4 to 12 which apply here accordingly.

The 14 shows a twelfth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 Two tablets 150 and 160 as well as a time delay element 200 can be seen, which, viewed in the gas flow direction G, is positioned in front of the 14 left tablet 160 is arranged.

In addition, one can see in the 14 a closure element 210, which is arranged between the step 155 in the flow channel 110 and the adjacent tablet 150. The closure element 210 thus also automatically closes the flow channel 110.

If, after triggering of the gas generator 40, in particular due to the effect of the time delay element 200, there is a time-delayed ignition of the two tablets 150 and 160, the time delay element 200 and the closure element 210 are also destroyed upon combustion of the two tablets 150 and 160, so that the flow channel 110 is released and flow through the drive piston 71 becomes possible. Furthermore, the above statements in connection with the 4 to 13 accordingly.

The 15 shows a thirteenth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 can be used. A closure element 210 can be seen, which rests on a step 155 in the flow channel 110. Furthermore, three tablets 150, 160, and 190 can be seen, each preferably made of pre-ignition material.

If, after the gas generator 40 is triggered, the three tablets 150, 160 and 190 are ignited, the closure element 210 is also destroyed by the cascaded combustion of the three tablets, so that the flow channel 110 is released and a gas flow through the drive piston 71 is enabled.

The 16 shows a fourteenth embodiment of a drive piston 71. The drive piston 71 is equipped with an internal delay volume 320 in the form of a pre-chamber, into which gas G from the gas generator 40 is introduced via four small inlet openings 330 according to 1 The gas G flows along the arrow direction P1 in the 16 from right to left towards drive piston 71.

The delay volume 320 is shown in the illustration according to 16 closed on the left side by a piston in the form of a valve piston 340, which is equipped with a one-piece molded shear ring 350. The shear ring 350 rests on an outer stop 360 of the drive piston 71 and prevents the valve piston 340 from being displaced to the left.

The valve piston 340 closes large inlet openings 370 through which the gas G of the gas generator 40 could penetrate into the interior of the drive piston 71 if these were not closed by the valve piston 340.

In order to ensure that the valve piston 340 is fixed inside the drive piston 71 in the rest state, a support pin 375 can be provided which is arranged between the 16 right inner surface 310a of the drive piston 71 and the valve piston 340 is arranged. The support pin 375 serves only to define the position of the valve piston 340 before activation of the gas generator 40. It does not exert any preload on the valve piston 340; it is merely loosely arranged between the inner surface 310a and the valve piston 340 for support and, of course, does not close the inlet openings 330 for the gas G of the gas generator 40.

In the 16 Furthermore, one can see outflow openings 380, which point diagonally outward at an angle of 45°. Gas G from the gas generator 40 can flow through the outflow openings 380 as soon as the large inflow openings 370 are opened by the valve piston 340.

• Sobald Gas G des Gasgenerators 40 entlang der Pfeilrichtung P1 auf den Antriebskolben 71 einwirkt, wird dieses durch die kleinen Einströmöffnungen 330 in das Verzögerungsvolumen 320 eindringen. Die Größe der Einströmöffnungen 330 ist derart gewählt, dass es eine gewisse vorgegebene Zeitspanne von ca. 5 ms dauert, bis der Druck im Inneren des Verzögerungsvolumens 320 so groß ist, dass der Abscherring 350 vom übrigen Ventilkolben 340 abgeschert wird und der Ventilkolben 340 entlang der Pfeilrichtung P2 in Richtung auf die in 16 linke Innenfläche 310b des Antriebskolbens 71 bewegt wird. Sobald es zu einem Abscheren gekommen ist, wird der Ventilkolben 340 die großen Einströmöffnungen 370 freigeben, so dass das Gas G des Gasgenerators 40 durch die großen Einströmöffnungen 370 ins Innere des Antriebskolbens 71 gelangen und nachfolgend durch die Abströmöffnungen 380 hindurch in den hinter dem Antriebskolben 71 befindlichen Abschnitt des Zuführungsrohres des Strafferantriebs 30 gelangen kann. Ein unmittelbares Vorbeifließen von Gas G außen am Antriebskolben 71 vorbei ist nicht möglich, da in einer umlaufenden Nut 390 ein Dichtring 395 eingesetzt ist, der den in 16 linken Abschnitt des Antriebskolbens 71 von dem rechten Abschnitt im Zuführungsrohr gasdicht trennt. Erst nachdem das Verzögerungsvolumen 320 mit Gas gefüllt worden ist und der Ventilkolben 340 nach links verschoben worden ist, wird durch die Freigabe der großen Einströmöffnungen 370 ein Gasfluss G durch das Innere des Antriebskolbens 71 hindurch zu den äußeren Abströmöffnungen 380 und damit auf die in 16 linke Seite des Antriebskolbens 71 ermöglicht.

The drive piston 71 preferably operates as follows:

• As soon as gas G from the gas generator 40 acts on the drive piston 71 along the direction of the arrow P1, it will penetrate into the delay volume 320 through the small inlet openings 330. The size of the inlet openings 330 is selected such that it takes a certain predetermined period of time of approximately 5 ms until the pressure inside the delay volume 320 is so great that the shear ring 350 is sheared off from the remaining valve piston 340 and the valve piston 340 moves along the direction of the arrow P2 towards the 16 left inner surface 310b of the drive piston 71 is moved. As soon as shearing has occurred, the valve piston 340 will release the large inlet openings 370, so that the gas G of the gas generator 40 can pass through the large inlet openings 370 into the interior of the drive piston 71 and subsequently through the outlet openings 380 into the section of the feed pipe of the tensioner drive 30 located behind the drive piston 71. A direct flow of gas G past the outside of the drive piston 71 is not possible, since a sealing ring 395 is inserted in a circumferential groove 390, which seals the 16 left section of the drive piston 71 from the right section in the feed pipe in a gas-tight manner. Only after the delay volume 320 has been filled with gas and the valve piston 340 has been moved to the left, a gas flow G is directed through the interior of the drive piston 71 to the outer outlet openings 380 and thus to the 16 left side of the drive piston 71.

The delay volume 320 thus functions as a pressure build-up delay device for the valve piston 340.

The 17 shows a fifteenth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 can be used. A valve piston 400 can be seen, which is held in a form-fitting manner in two holes 420 and 421 in the housing 430 of the drive piston 71 by a form-fitting section 410. The position of the valve piston 400 inside the drive piston 71 is thus fixed by form-fitting before the activation of the tensioner drive 30.

The 17 also shows an inlet opening 440, which allows a gas flow G from the gas generator 40 into a delay volume 450 inside the drive piston 71. As soon as the gas pressure inside the delay volume 450 is sufficiently high, the positive-locking section 410 or the positive-locking connection between the valve piston 400 and the two holes 420 and 421 will break open, and the valve piston 400 will move along the direction of arrow P2. As soon as the valve piston 400 is moved upward in the direction of arrow P2, the two holes 420 and 421 are opened, allowing a gas flow G through the two holes 420 and 421 to outflow openings 460 in the housing 430 of the drive piston 71.

18 shows the drive piston 71 according to 17 in a three-dimensional view obliquely from the side. The hole 420, in which the positive-locking section 410 of the valve piston 400 is engaged, can be seen. Furthermore, the outflow openings 460 can be seen, through which, after the valve piston 400 has been displaced, gas G from the gas generator 40 can flow through the drive piston 71.

The 19 shows the drive piston 71 according to the 17 and 18 after the valve piston 400 has been pushed upwards due to pressure along the direction of arrow P2 and has released the two holes 420 and 421. Furthermore, two arrows P3 can be seen, which symbolize the gas flow of gas from the gas generator 40 through the two holes 420 and 421 to the outflow openings 460 of the drive piston 71.

The 20 shows the drive piston 71 according to the 17 to 19 again in a view from above.

The 21 shows a sixteenth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 who used The drive piston 71 is equipped with a closure element 500, which is in a locked position before the gas generator 40 is triggered. This locked position shows the 21 .

In the blocking position, the closure element 500 closes a flow channel 110 that extends through the drive piston 71. The flow channel 110 begins at an inflow opening 510, which is located on the side of the drive piston 71 facing the gas generator 40, and ends at one or more outflow openings 520, which in the embodiment according to 21 are arranged in the central region of the drive piston 71.

In its closed position, the closure element 500 covers the outflow openings 520 and thereby closes the flow channel 110, so that the gas G of the gas generator 40 cannot flow through the drive piston 71. In the closed position, the drive piston 71 thus acts as a seal.

A receiving chamber 530 is located behind the closure element 500 along the flow direction of the gas G of the gas generator 40 and thus along the direction of movement B of the drive piston 71 and the upstream thrust bodies 70. The receiving chamber 530 is filled with a fluid 540, which can be pressed out of the receiving chamber 530 through an outflow channel 550 connected to the receiving chamber 530. In the 21 In the initial state shown, the outflow channel 550 is preferably closed with a sealing element (not shown) in order to prevent unwanted or premature leakage of the fluid 540 from the receiving space 530.

If the gas generator 40 is operated according to 1 ignited, the gas G of the gas generator 40 will act on the drive piston 71 as a whole and move it in the illustration according to 21 from right to left. In addition, the gas G or the gas pressure will act on the closure element 500 and exert a thrust force that will move the closure element 500 along the direction of movement B - i.e. from right to left in 21 - relative to the other components of the drive piston 71 and in particular relative to the flow channel 110.

The gas pressure of the gas G is transferred from the closure element 500 to the fluid 540 in the receiving space 530, so that the fluid is pushed out of the receiving space 530 toward the outflow channel 550. The sealing element closing the outflow channel 550 in the initial state is broken open or pushed out by the excess pressure, so that fluid movement through the outflow channel 550 to the outside becomes possible.

The 22 shows the drive piston 71 according to 21 after its closure element 500 has been pressed into the receiving space 530 and the fluid 540 has been completely expelled from the receiving space 530. The movement of the closure element 500 releases the outflow openings 520 and thus the flow channel 110, allowing a gas flow G from the inflow opening 510 through the flow channel 110 and the outflow openings 520. In other words, the displacement of the closure element 500 within the drive piston 71 causes the drive piston 71 to lose its sealing effect.

The time delay after triggering of the gas generator 40 according to 1 the opening of the flow channel 110 within the drive piston 71 is significantly influenced by the diameter or cross section of the outflow channel 550, the length of the outflow channel 550, the viscosity of the fluid 540, the diameter (or cross section) of the receiving space 530, the diameter (or cross section) of the closure element 500, the volume of the receiving space 530, the volume of the fluid 540 and the gas pressure of the gas generator 40 and can be adjusted virtually arbitrarily by selecting these parameters.

The 23 shows a seventeenth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 The drive piston 71 according to 23 has - in accordance with the embodiment according to the 21 and 22 - a closure element (here the reference numeral 600) which is arranged in the 23 shown blocking position or in the initial state of the drive piston 71 closes a flow channel 110 through the drive piston 71. In this way, in the 23 recognize that the closure element 600 is arranged spatially in front of an outflow opening 520, which would be in flow connection with an inflow opening 510 if the closure element 600 were not located therebetween.

The closure element 600 is in the embodiment according to 23 cup-shaped and has a cup bottom 610 facing the gas generator 40. Adjoining the cup bottom 610 is a cup wall 620, which extends away from the gas generator 40 in the direction of the thrust body 70 located in front of the drive piston 71.

Located in front of the closure element 600 along the direction of movement B of the thrust bodies 70 and the drive piston 71 in the feed tube 60, as seen, is a receiving space 530 filled with a fluid 540. The receiving space 530 is shaped at least approximately complementary to the cup-shaped closure element 600.

During the movement of the closure element 600 along the direction of movement B, the cup wall 620 is pushed onto a complementarily shaped elevation in the form of a projection 640 on the inner wall of the receiving space 530. During this pushing out, a fluid channel 630 is formed, in which the fluid 540 must flow against the direction of movement B of the closure element 600 in order to reach the outflow channel 550. This shows the 24 in more detail, in which the closure element 600 has a middle position between the blocking position according to 23 and a full release (see 25 ). Due to the inverse flow direction of the fluid or the reversal of movement, the movement of the closure element 600 can be braked very efficiently even with a small receiving space 530.

In the embodiment according to the 23 to 25 the outflow channel 550 is arranged within the projection 640; preferably, the outflow channel 550 is arranged in the central region of the projection 640 and coaxial therewith.

The 25 shows the drive piston 71 according to the 23 and 24 after the closure element 600 has been completely pushed onto the projection 640 or has been completely pushed into the receiving space 530. The fluid previously located in the receiving space 530 (cf. 23 ) has been pushed out of the receiving space 530 through the outflow channel 550.

In the in the 25 In the position shown (release position), the closure element 600 releases the outflow opening 520, so that the outflow opening 520 is in flow connection with the inflow opening 510 or the flow channel 110 between the outflow opening 520 and the inflow opening 510 is released.

The 26 shows an eighteenth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 A closure element 700 can be seen, which is equipped with through-openings 710. In the 26 In the blocking position of the closure element 700 shown, the closure element 700 closes a flow channel 110 between outflow openings 520 and an inflow opening 510 facing the gas generator 40.

If the closure element 700 is moved along the direction of movement B of the drive piston 71 in the feed pipe 60 - that is, in the illustration according to 26 from right to left - into the receiving space 530, it will press the fluid 540 located in the receiving space 530 out of the drive piston 71 through the outflow channel 550, as described in connection with the 21 to 25 has already been explained in detail. The movement of the closure element 700 within the drive piston 71 will in turn cause the through-openings 710 of the closure element 700 to be displaced relative to the outflow openings 520, so that the through-openings 710 are brought into overlap with the outflow openings 520.

The 27 shows the drive piston 71 according to 26 after the through-openings 710 and the outflow openings 520 overlap and the flow channel 110 between the outflow openings 520 and the inflow opening 510 has been opened. Thus, a gas flow from the inflow opening 510 through the drive piston 71 to the outflow openings 520 is possible, so that the drive piston 71 has lost its sealing effect.

The 28 to 30 show by way of example using the sixteenth embodiment (cf. 21 and 22 ), how the receiving space 530 can be filled with a fluid 540. In the 28 a filling device 800 can be seen, which has been inserted from the outside through the outflow channel 550 into the interior of the receiving space 530.

With the filling device 800, the fluid 540 is filled into the receiving space 530, whereby the closure element 500 is pushed in the direction of the inflow opening 510 (cf. 29 ). As soon as the closure element 500 reaches its locking position, as exemplified in connection with the 21 explained, the filling device 800 is pulled out of the outflow channel 550 and the outflow channel 550 is closed with a sealing element 810 (cf. 30 ).

The 31 shows a nineteenth embodiment of a drive piston 71 which is used in the tensioner drive 30 according to 1 can be used. In the embodiment according to 31 a fluid 540 is enclosed in a foil envelope 850 and forms a fluid sac 860.

Due to the foil envelope 850, the fluid 540 cannot leak prematurely through the outflow channel 550, even if it is not sealed by a sealing element, such as the sealing element 810 according to 30 , is closed. Such a sealing element can thus be dispensed with. The fluid 540 can only escape through the outflow channel 550 if the film sleeve 850 bursts or tears due to the excess pressure upon movement of the closure element 500 into the receiving space 530.

The fluid sachet 860 is preferably introduced from the inflow opening 510 before the closure element 500 is inserted.

Furthermore, the explanations in connection with the embodiments apply according to the 21 to 27 in the embodiment according to 31 accordingly.

A fluid as described in connection with the embodiments according to the 21 to 31 explained, can also be used in the embodiments according to the 16 to 20 be used to brake the movement of the valve piston 340 or 400, which acts as a closure element. For this purpose, the fluid is placed in front of the valve piston 340 or 400, as seen along the direction of movement of the valve piston 340 or 400.

List of reference symbols

10

Belt retractor

20

Belt spindle

30

tensioner drive

35

Inertia coupling

40

Gas generator

50

drive wheel

51

retaining cap

52

holding plate

60

feed pipe

70

thrust body

71

drive piston

75

Feather

80

Holder

81

Receptacle

100

seal

105

front section

110

Flow channel

115

pyrotechnic charge

150

tablet

155

Level

160

tablet

170

tablet

175

retaining panel

180

tablet

185

retaining panel

190

tablet

200

Time delay elements

210

locking element

310a

right inner surface of the drive piston

310b

left inner surface of the drive piston

320

Delay volume

330

small inlet opening

340

valve piston

350

Shear ring

360

outer stop

370

large inlet opening

375

Support pin

380

Outlet opening

390

Groove

395

sealing ring

400

valve piston

410

Form-fitting section

420

Hole

421

Hole

430

Housing

440

Inlet opening

450

Delay volume

460

Outlet openings

500

locking element

510

Inlet opening

520

Outlet openings

530

recording room

540

Fluid

550

Outlet channel

600

locking element

610

Cup bottom

620

Cup wall

630

Fluid channel

640

projection, elevation

700

locking element

710

Through openings

800

Filling device

810

Sealing element

850

foil cover

860

Fluid sachets

B

Direction of movement

G

Gas flow direction / Gas stream / Gas flow / Gas

P1

Arrow direction

P2

Arrow direction

P3

arrows

Claims (13)

A tensioner drive (30) for a safety belt device, comprising: - a gas generator (40), - a drive wheel (50), and - a feed tube (60) connecting the gas generator (40) and the drive wheel (50), - wherein a plurality of thrust bodies (70, 71) are present in the feed tube (60), which are accelerated after the gas generator (40) is triggered and drive the drive wheel (50), - wherein at least one of the thrust bodies (71) completely or at least partially seals the feed tube (60), and - wherein the tensioner drive (30) is designed such that the sealing effect of the at least one sealing thrust body (71) is terminated or reduced with a time delay after the ignition of the gas generator (40), characterized in that - the sealing thrust body (71) has at least one flow channel (110) which, before the ignition of the gas generator (40), is Closure element (500, 600, 700) is closed and is released when the closure element (500, 600, 700) moves relative to the flow channel (110), in particular driven by the gas pressure of the gas generator (40) after the triggering of the gas generator (40), - wherein the movement of the closure element (500, 600, 700) is braked by a fluid (540), - wherein the fluid (540) is located in the sealing thrust body (71), specifically - viewed along the flow direction of the gas of the gas generator (40) and thus along the direction of movement (B) of the thrust bodies (70) in the feed pipe (60) - behind the closure element (500, 600, 700), and - wherein the fluid (540) is caused by the movement of the closure element (500, 600, 700) relative to the flow channel (110) is pushed out of the thrust body (70). Tensioner drive (30) after Claim 1 , characterized in that - in the thrust body (70) - seen along the flow direction of the gas (G) of the gas generator (40) - behind the closure element (500, 600, 700) there is a receiving space (530) into which the closure element (500, 600, 700) is pressed by the gas pressure of the gas generator (40) during its movement relative to the flow channel (110), - the fluid (540) is located in this receiving space (530) before the triggering of the gas generator (40), and - the fluid (540) after the triggering of the gas generator (40) is discharged from the receiving space (530) through the closure element (500, 600, 700) penetrating into the receiving space (530) and out of the thrust body through at least one outflow channel (550) connected to the receiving space (530). (70) is pushed out. Tensioner drive (30) after Claim 2 , characterized in that the outflow channel (550) in the initial state, i.e. before the triggering of the gas generator (40), is closed to the outside by a sealing element (810) and the fluid (540) is locked in the receiving space (530). Tensioner drive (30) according to one of the preceding claims, characterized in that the fluid (540) is enclosed in a film sleeve (850) and forms with this a fluid sac (860). Tensioner drive (30) according to one of the preceding claims, characterized in that the cross section of the outflow channel (550) is smaller than the cross section of the receiving space (530). Tensioner drive (30) according to one of the preceding claims, characterized in that the closure element (500, 600, 700) and the receiving space (530) are shaped so as to complement one another in such a way that when the closure element (500, 600, 700) penetrates into the receiving space (530), a fluid channel (630) delimited by the closure element (500, 600, 700) and the receiving space (530) is formed in the interior of the receiving space (530), in which fluid channel the fluid (540) flows counter to the flow direction of the gas (G) of the gas generator (40) and thus counter to the direction of movement (B) of the closure element (500, 600, 700). Tensioner drive (30) according to one of the preceding Claims 2 until 6 , characterized in that - the closure element (500, 600, 700) at least is cup-shaped in sections, wherein a cup bottom (610) of the closure element (500, 600, 700) faces the gas generator (40) and a cup wall (620) extends away from the cup bottom (610) and the gas generator (40), and - the receiving space (530) has a protrusion (640) extending in the direction of the closure element (500, 600, 700) and in the direction of the gas generator (40), - wherein the cup wall (620) is pressed into the receiving space (530) during the movement of the closure element (500, 600, 700) and is turned over the protrusion (640), and in the process a fluid channel (630) is formed between the cup wall (620) and the protrusion (640), in which the fluid (540) flows counter to the direction of movement (B) of the closure element (500, 600, 700) flows. Tensioner drive (30) after Claim 7 , characterized in that an outflow channel (550) is arranged in the elevation (640), which is fluidly connected to the fluid channel (630) and enables the fluid (540) to flow out of the thrust body (70) along the direction of movement (B) of the closure element (500, 600, 700). Tensioner drive (30) according to one of the preceding claims, characterized in that - the closure element (500, 600, 700) has a through-opening which is offset from the flow-through channel (110) before the ignition of the gas generator (40) and is only brought into overlap with the flow-through channel (110) by a movement of the closure element (500, 600, 700) relative to the flow-through channel (110), by means of which a gas flow through the closure element (500, 600, 700) and the flow-through channel (110) is made possible. Tensioner drive (30) according to one of the preceding claims, characterized in that the fluid (540) is a liquid. Tensioner drive (30) according to one of the preceding claims, characterized in that the liquid has a viscosity whose change in a temperature range between -40°C and 95°C is less than 1000%. Tensioner drive (30) according to one of the preceding claims, characterized in that the liquid is a silicone liquid or at least a silicone-containing liquid. Tensioner drive (30) according to one of the preceding claims, characterized in that the liquid has a viscosity between 500,000 cSt and 4,000,000 cSt.

Images