JP2007522428A - Electric ignition detonator with heat dispersion - Google Patents

Abstract

  In accordance with the present invention, an electric ignition detonator is provided between the heater resistance element (17) and its support (16) under the element (17) and the heat generated by the heater resistor element (17). Of the heat spreader (31) to the support (16) and the element (17) while electrically insulating the heat spreader (31) from the heater resistor element (17). Means (32, 33) for allowing the heat transferred to the heat disperser (31). The present invention increases the reliability of the detonator by raising the no-ignition limit value towards the full ignition limit value, thereby reducing the size of the transition zone between them.

Description

  The present invention relates to an electric ignition initiation device.

  The scope of the invention relates to a plurality of devices for improving automobile occupant protection, for example, a plurality of detonators that ignite a plurality of pyrotechnic charges of a plurality of gas generators for an air bag.

  Usually, such a detonator includes a starter ignition actuator and a heater resistor element covered by the starter ignition operating part in order to ignite by the Joule effect. Two electrodes are provided for supplying electricity.

  The operation of the electric ignition detonator is affected by the combination of the resistor element and the starting ignition actuating unit, and further the sensitivity given to such detonator in the combination used.

  Therefore, the limit value (all-fire threshold) of all ignitions coincides with the limit value of the current flowing through the plurality of electrodes. Above the current limit, the detonator must function, i.e., the ignition pyrocharge should ignite.

  The no-fire threshold that is lower than the limit value of the total ignition matches the limit value of the current flowing through the plurality of electrodes. Below the current limit value, the detonator will not function reliably, i.e. the starting ignition actuator should not ignite.

  There is a transition zone (region) between the limit value of no ignition and the limit value of all ignition, and it is not certain whether or not the detonator functions in that zone.

  It is an object of the present invention to achieve an electric ignition detonator that helps to reduce the uncertainty region regarding the function of the electric ignition detonator between the limit value of no ignition and the limit value of full ignition.

For this purpose, the first aspect of the present invention comprises a starting ignition actuating part, a heater resistor element covered by the starting ignition actuating part, two electrodes for supplying electricity to the heater resistor element, and a heater resistance. There is provided an electric ignition initiation device including a container element support portion.
The detonator further includes a heat spreader for dispersing heat generated by the heater resistor element between the support portion and the heater resistor element at least under the heater resistor element toward the support portion. And means for conducting heat generated by the heater resistor element to the heat spreader and electrically insulating the heat spreader from the heater resistor element.

  According to the invention, during operation of the detonator, some of the heat generated by the heater resistor element is distributed towards the support. The limit value of no ignition increases toward the limit value of total ignition. Thereby, the transition zone between them is reduced. While the limit value of no ignition increases, the limit value of total ignition is substantially stable. As a result, the detonator of the present invention provides excellent safety during operation and is more robust against sudden currents. Therefore, the present invention makes it possible to satisfactorily meet the requirements determined by a plurality of automobile manufacturers with respect to the limit values of no ignition and total ignition.

According to other features of the invention:
The electrically insulating and thermally conducting means comprises a first layer of adhesive which is inserted between the heater resistor element and the heat spreader and which conducts and electrically insulates.
A second layer of adhesive that conducts heat and is electrically insulated is inserted between the heat spreader and the support;
-Alternatively, the heat spreader is in direct contact with the support.
The heat spreader is formed of a heat conducting layer;
The heat spreader is made of a material selected from a plurality of metal materials and ceramic materials;
The heat spreader is made of a metal selected from copper, aluminum, their alloys, or their oxides.
The heat spreader is placed under the heater resistor element, and the heater resistor element is covered with two electrical contacts that are separated from each other and contact each one of the two electrodes. Yes.

  The invention will be better understood with the following description of an example without any limitation with reference to the accompanying drawings.

  An electric ignition detonator 1 according to the present invention is shown in FIG. The detonator 1 comprises a cylindrical container 2 that is circular around the vertical axis of the detonator, is splittable, and opens at one of a plurality of tips. A rigid, circular cylindrical body 3 closes the opening of the container 2. The side wall 4 of the main body 3 forms an annular shoulder 5 that supports the open end of the container 2. The container 2 and the main body 3 are wrapped in an outer molded body (overmolding) 6 that holds them together. The container 2 is therefore in the form of a cylindrical cap consisting of a side wall 7 and a flat, closed and rigid top wall 8. As an example, the container 2 also includes a metal tube 20 that reinforces the side wall 7. The container 2 is preferably made of a thin and light metal such as aluminum, for example, and the flat upper wall 8 is preferably weakened so that it can be easily opened by the effect of increasing the pressure present in the container. The outer molded body 6 is preferably made of a resin that softens when heated, for example, polyethylene terephthalate. The main body 3 is made of a dense metal, for example, iron.

  The body 3 has a flat lower surface 15 as well as a flat upper surface 9 and encloses an electrically insulated structure over its entire height h, through the structure, two conductive electrodes 12 and 13. Has passed. This structure through which the two electrodes 12 and 13 are passed is, for example, glassy. The two electrodes 12 and 13 are, for example, in the form of pins. In the illustrated embodiment, the structure through which the two electrodes 12 and 13 are passed is made up of two hollow, electrically insulating glass tubes 10 and 11, which are connected to the two electrodes 12 and 12. Wrap 13 each. In a variant, the structure through which the two electrodes 12 and 13 pass can comprise a single glass tube 10 or 11 that encloses the corresponding electrode 12 or 13. In another variant, the body 3 can be directly wrapped around the electrodes 12 and 13 without using the electrically insulated glass tubes 10 and 11, for example by making it a glass body. In an embodiment not shown, one of the electrodes 12 and 13 encased in the electrically insulated glass tubes 10 and 11 may be of the coaxial type, i.e. via a connection located below it. The main body 3 is electrically connected.

  The flat upper surface 9 of the main body 3 is fixed to the support portion 16 with an adhesive. In the embodiment shown as examples in the drawings, the support 16 is made of an electrically insulating material separated from the electrodes 12 and 13, and is made of an epoxy system filled with glass fiber. It consists of a single plate formed of a mixture of glass and resin such as synthetic polymer. Two penetrating cylindrical passages 22 and 23 are provided in the support 16 through which the two electrodes 12 and 13 pass. Each of the electrodes 12, 13 has a respective front end portion 12 b, 13 b that protrudes beyond the flat upper surface 9 of the main body 3 and the upper surface of the support portion 16, and a second front end portion 12 c that protrudes beyond the bottom surface 14 of the outer molded body 6. 13c.

  The support 16 includes a heater resistor element 17 or a thermal resistance element 17 and holds an electrical circuit 18 that is electrically connected to the electrodes 12 and 13.

  Resistor element 17 is photoetched in a conventional manner. Resistor element 17 is provided with an upper surface 24 that encloses the start-up ignition actuating part contained in container 2 or in the illustrated embodiment in container 2 and metal tube 20. This starting ignition actuating part wraps, for example, an initiation pyrotechnic composition 19 in contact with the heater resistor element 17 and based on lead trinitroresorcin, and an initiating composition or initiation ignition compound 19. And an explosive 21 based on nitrocellulose or a mixture of boron and potassium. As an example, the heater resistor element 17 is flat. For the detonator in the table below, the detonation ignition compound 19 may also be a mixture of zirconium and potassium perchlorate, and the detonation explosive 21 may be a mixture of titanium hydride and potassium perchlorate. .

  As an example, the heater resistor element 17 is made of a metal, for example formed by an intermediate part of the electrically conductive (conductive) layer 25 and another alloy such as a nickel / chromium alloy or a PtW alloy, for example. The Apart from the middle part forming the heater resistor element 17, the layer 25 is covered by two separate electrical contacts 26 and 27 which are in separate contact with the two electrodes 12 and 13. Contacts 26 and 27 are covered by the starting ignition actuator and cooperate with layer 25 to form electrical circuit 18, for example, comprising a copper layer 28 on layer 25. This copper layer is covered, for example, by another metallized layer 29. The outer layer 25 and contacts 26 and 27 of the heater resistor element 17 have electrodes 12 and 13 therethrough.

  2 and 3, a heat spreader 31 is provided between the support 16 and the heater resistor element 17. The heat spreader 31 may be any suitable means that allows the heat produced by the heater resistor element 17 to be conducted toward the heat spreader 31 by means of the electrodes 12 and 13 and the heater resistance. It is electrically insulated from the vessel element 17. 2 and 3, the heat spreader 31 does not contact the heater resistor element 17. The heat spreader 31 conducts heat and assists in the dispersion of heat generated by the heater resistor element 17 toward the support portion 16. As an example, the heat spreader is greater than or equal to 100 milliwatts per centimeter (mW / cm.K) per kelvin (possible by at least a thermally conductive copper-based alloy constantan). Preferably provide a thermal conductivity greater than or equal to 200 mW / cm.K.

  The heat spreader 31 is located below the heater resistor element 17 in the resistor, etc., for example, as indicated by the dotted lines in FIGS. 2 and 3, or otherwise indicated by a continuous line in FIGS. As you can see, it protrudes beyond the location under the contacts 26 and 27. The figures do not have a scale or ratio between dimensions, and the heat spreader 31 is, for example, a resistor that is close to or longer than the length of the heater resistor element 17 between the contacts 26 and 27. It may extend under the vessel element. As an example, the disperser 31 may surround the passages 22 and 23 and the pins 12 and 13 without touching them.

  As shown in FIGS. 2 and 3, the heat disperser 31 includes, for example, a heat conduction layer 31 having a predetermined continuous thickness. As an example, the heat spreader 31 is made of metal such as copper or aluminum, that is, is conductive. Of course, any other heat conducting material can be used for the heat spreader 31.

  In the embodiment shown in FIGS. 2 and 3, in order to electrically insulate the heat spreader 31 from the heater resistor element 17, the first layer 32 of the thermally conductive and electrically insulating adhesive is a heater. It is inserted between the resistor element 17 and the heat spreader 31. The adhesive layer 32 forms a physical contact between the heater resistor element 17 and the heat spreader 31. The adhesive layer 32 has a thickness between the heater resistor element 17 and the heat spreader 31, and the thickness is less than half of the total thickness of the adhesive layer 32 between the circuit 18 and the support 16. .

  In the embodiment shown in FIG. 2, a second layer 33 of adhesive that is thermally conductive and electrically insulating is inserted between the heat spreader 31 and the support 16. The adhesive layer 33 forms a physical contact between the disperser 31 and the support 16. As an example, the first layer 32 and the second layer 33 surround the entire surface of the heat spreader 31 between the support portion 16, the heater resistor element 17, and the passages 22 and 23 for passing the electrodes 12 and 13. The passages 22 and 23 and the thickness of the heat spreader 31 intersect each other. Accordingly, the heat spreader 31 is buried in the first layer and the second layers 32 and 33. The first layer 32 and the second layer 33 meet around the passages 22 and 23 that support the conductive layer 25.

  In the embodiment shown in FIG. 3, the second layer of adhesive 33 is removed under the heat spreader 31, which is in direct contact with the support 16. To do this, the heat spreader 31 is placed at the desired location on the support 16 with a flat top surface, and the layer of adhesive 32 followed by the circuit 18 is placed on the heat spreader 31 and the support 16. The A first layer 32 of adhesive surrounds the top and side of the heat spreader 31 between the support 16, the heater resistor element 17, and the passages 22, 23 through the electrodes 12 and 13, and the passage 22, 23, the heat spreader 31, and the support portion 16. The first layer 32 surrounds the passages 22 and 23 that serve to support the conductive layer 25. The disperser 31 may be partially inserted into the corresponding recess of the support portion 16 in the thickness direction. Therefore, as shown in FIG. 4, the bottom surface 34 and a part of the side surface 35 are in contact with the recess of the support portion 16.

Heat is generated by the heater resistor element 17 when electricity flows through the electrode from an external power source of a circuit for controlling the operation of the initiator (not shown). A part of this heat is diffused through the first layer 32 of the heat disperser 31 and further into the support 16 from the disperser via the second layer 33 or directly from the heat disperser 31. Passes into the support 16. Because of the structure and / or the material from which the structure is made, i.e., in the illustrated embodiment, a material made from an epoxy-filled fiberglass synthetic polymer, the support 16 is a heater resistor element. The heat from 17 is discharged. The presence of the heat spreader 31, as shown in the table below, makes it possible to set and increase the non-ignition limit value so as to reduce the difference between the non-ignition limit value and the total ignition limit value. To do. And in the table, the non-ignition current and the total ignition current have 99.9% reliability, the element 17 is made of NiCr, and in the table, due to the presence of the disperser, no ignition Current has increased by 44% or more. Thereby, the reliability of the operation of the detonator is further improved.

FIG. 1 is a schematic axial sectional view of a detonator according to the present invention. FIG. 2 is a schematic axial cross-sectional view showing the arrangement of heater resistor elements on the support in the first embodiment of the detonator of FIG. FIG. 3 is a schematic axial cross-sectional view showing the arrangement of heater resistor elements on the support in the second embodiment of the detonator of FIG. FIG. 4 is a schematic axial cross-sectional view showing the arrangement of heater resistor elements on the support in the third embodiment of the detonator of FIG.

Claims (9)

A starting ignition actuating part (19, 21);
A heater resistor element (17) wrapped in the start ignition actuating part (19, 21);
Two electrodes (12, 13) for supplying electricity to the heater resistor element (17);
In the electric ignition detonator comprising the heater resistor element (17) support (16),
Between the support (16) and the heater resistor element (17), at least under the heater resistor element (17),
A heat spreader (31) for dispersing heat generated by the heater resistor element (17) toward the support (16);
A first layer of adhesive (32) inserted between the heater resistor element (17) and the heat spreader (31) and thermally conductive and electrically insulating;
The electric ignition detonator characterized by further comprising.   The electric ignition detonator according to claim 1, characterized in that the heat disperser (31) has a thermal conductivity greater than or equal to 100 mW / cm.K.   The second layer (33) of heat conducting and electrically insulating adhesive is inserted between the heat spreader (31) and the support (16). The electric ignition detonator according to claim 2.   The electric ignition initiation device according to claim 1 or 2, wherein the heat disperser (31) is in direct contact with the support portion (16).   The electric ignition initiation device according to any one of claims 1 to 4, wherein the heat disperser (31) is formed of a heat conductive layer (31).   The electric ignition detonator according to any one of claims 1 to 5, wherein the heat disperser (31) is made of a material selected from a metal material and a ceramic material.   Electricity according to any one of the preceding claims, characterized in that the heat spreader (31) is made of a metal selected from copper, aluminum, alloys thereof or oxides thereof. Type ignition detonator.   The electric ignition detonator according to any one of claims 1 to 7, wherein the heat spreader (31) is installed under the heater resistor element (17).   Heater resistor element (17) is covered by two electrical contacts (26, 27) that are separated from each other and in contact with each one of the two electrodes (12, 13). 9. The electric ignition detonator according to any one of 1 to 8.

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