CN114439947A

CN114439947A - Medium metering valve

Info

Publication number: CN114439947A
Application number: CN202111271420.XA
Authority: CN
Inventors: M·库尔茨
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2020-10-30
Filing date: 2021-10-29
Publication date: 2022-05-06
Also published as: DE102020213663A1

Abstract

The invention relates to a media metering valve (100) having a metering opening (105), in particular a nozzle, a media supply channel (22), a media space (21) and a valve closing element (1) for opening and closing the metering opening (105) relative to the media space (21), wherein a sealing seat (51) is provided against which the valve closing element (1) rests when the metering opening (105) is closed, wherein an elastomer element (7) is arranged on an end face (11) of the valve closing element (1) facing the sealing seat (51), wherein the elastomer element (7) is of disc-shaped design, wherein a first side (110) of the elastomer element (7) rests in a surface-like manner against the end face (11) of the valve closing element (1) facing the sealing seat (51), wherein a second side (115) of the elastomer element (7) opposite the first side (110) rests on the sealing seat (51) with the dosing opening (105) closed.

Description

Medium metering valve

Technical Field

The invention relates to a medium metering valve.

Background

A gas valve for dosing gaseous fuel is known from DE 102014223678 a 1. The gas valve comprises a valve closing element for opening and closing the through-hole, a seal seat between the valve closing element and the stationary seal, wherein the valve closing element has a sealing element with an elastomeric seal made of an elastic sealing material and a seal carrier, and wherein the seal carrier has a circumferential recess which is filled with the sealing material and forms a secondary region of the elastomeric seal which is spaced apart from a sealing region of the elastomeric seal on the seal seat.

Disclosure of Invention

In contrast, the media metering valve according to the invention has the following advantages: the media metering valve has a metering opening, in particular a nozzle, and a media supply channel, a media space, and a valve closing element for opening and closing the metering opening relative to the media space, wherein a sealing seat is provided against which the valve closing element rests when the metering opening is closed, wherein an elastomer element is arranged on an end face of the valve closing element facing the sealing seat, wherein the elastomer element is of disc-shaped design, wherein a first side of the elastomer element rests in a face-to-face manner on the end face of the valve closing element facing the sealing seat, and wherein a second side of the elastomer element lying opposite the first side rests on the sealing seat when the metering opening is closed. In this way, a particularly simple construction of the elastomer seal formed by the elastomer element can be achieved, which also seals off various types of media robustly due to its bearing on one side against the end face of the valve closing element facing the sealing seat and on the other side against the sealing seat when the metering opening is closed, without the use of chemical connection types, in particular without the need to vulcanize the elastomer element onto a metal carrier.

Advantageous embodiments and improvements of the media metering valve according to the invention can be achieved by the features listed in the preferred embodiments.

A sufficient sealing effect is already produced if the elastomeric element completely covers the sealing seat with the dosing opening closed.

The sealing effect is enhanced if the elastomeric element completely covers the dosing opening with the dosing opening closed.

It is also advantageous that the elastomer element only bears against the sealing seat when the metering opening is closed. In this way, the elastomeric element can be realized as an integral part of the valve closing element. This improves the robustness of the seal compared to placing the elastomeric element on the seal seat.

The connection between the elastomer element and the valve closing element is particularly robust and stable if the elastomer element is connected to the valve closing element in a force-fitting and/or form-fitting manner, wherein, according to an advantageous configuration, this connection can be realized in a structurally simple and cost-effective manner by the elastomer element being fastened to the valve closing element by means of a clamping sleeve.

In order to arrange the clamping sleeve on the valve closing element in a particularly simple and cost-effective manner, the valve closing element comprises a radial recess for receiving the clamping sleeve.

A further advantage results if the elastomer element comprises a flange, in particular an at least partially circular ring-shaped flange, in particular in the form of an O-ring. In this way, especially in the case of a circular ring-shaped flange, if the flange is pressed against the end face of the valve closing element, a pressure gradient at the elastomer body can be achieved within the diameter of the flange

This pressure gradient presses the elastomer against the end face of the valve closing element and thus improves the sealing effect.

It is also advantageous that the flange is arranged concentrically with the dosing opening. Thus, a rotationally symmetrical seal is obtained which, when the valve element is operated to close the dosing opening, enables a uniform introduction of force onto the elastomeric element and thus a reduced wear.

For the highest possible sealing effect of the elastomeric element, the diameter of the flange is selected to be larger than the diameter of the sealing seat. The flange seals against the valve closing element and the area of the elastomeric element within the inner diameter of the flange seals against the dosing opening by means of the sealing seat.

The sealing effect of the elastomer element with respect to the valve closing element is increased if a first recess, in particular an at least partially annular first recess, is arranged in the valve closing element for receiving the flange, in particular in the clamped condition.

The sealing effect of the elastomer element on the valve closing element is further increased if a second recess, in particular an at least partially annular second recess, is arranged on the clamping sleeve in the first projection facing the end face of the valve closing element, which second recess serves to receive the flange, in particular in the clamped state.

If the internal height of the clamping sleeve is at its maximum, preferably not exactly corresponding to the height of the radial recess of the valve closing element plus the height of the elastomer body, sufficient clamping is produced to achieve as high a sealing effect as possible between the valve closing element and the elastomer body element. Furthermore, the following advantages are also thereby achieved: the sealing function of the sealing seat is present even if the contact between the end face of the valve closing element and the elastomeric element is not present anywhere inside the inner diameter of the flange.

In order to assist the sealing effect of the elastomer element when the elastomer element bears against the sealing seat with the metering opening closed, the sealing seat advantageously has a projection, in particular an at least partially annular projection, on its end face facing the valve closing element, which projection is pressed into the elastomer element with the metering opening closed.

Local strains in the elastomer element can be avoided or reduced if the clamping sleeve comprises a second projection, in particular an at least partially annular second projection, on its side facing away from the end face of the valve closing element, which second projection rests on a metering opening body surrounding the metering opening with the metering opening closed, in order to limit the penetration depth of the projection into the elastomer element. In this way, the impairment of the strength of the elastomeric element and thus the wear on the elastomeric element can be reduced.

Drawings

Embodiments of the invention are illustrated in the drawings and are set forth in more detail in the description that follows.

The figures show:

figure 1 shows a sectional view of a media metering valve according to the invention with the metering opening closed,

figure 2 shows a detail of figure 1 in the region of the sealing seat,

figure 3 shows an exploded view of the media metering valve according to the section of figure 1 in the region of the sealing seat according to figure 2,

fig. 4 shows an alternative embodiment of a media metering valve in the region of a sealing seat in the section according to fig. 1.

Detailed Description

In fig. 1, a media metering valve, for example a gas valve for metering in hydrogen, in particular, is designated by 100, which can be used, for example, in a mobile fuel cell system. The media metering valve 100 is also referred to below simply as a valve. The valve housing 2 of the valve 100 comprises a valve closing element 1, preferably of metal. The valve closing element 1 is guided centrally in the valve housing 2 by means of a first guide 3 and a second guide 4. In the region of the outflow side of the valve 100, the valve housing 2 encloses a metering opening body 5 with a metering opening 105, which is designed as a nozzle, for example. The metering-opening body is therefore also referred to below as nozzle body. The nozzle body 5 is connected to the valve housing 2 in a force-fitting or form-fitting manner. In the central region 135 of the valve closing element 1, the valve closing element 1 is arranged in the magnetic field of the electromagnet group 6 surrounding the valve housing 2. The valve closing element 1 thus forms a magnetic armature, also referred to below simply as armature. The spring 9 is supported on an inner end stop 140 of the valve housing 2, which end stop is opposite the nozzle body 5, and presses the armature 1 against the armature-side end of the nozzle 105 via an abutment surface 145 of the armature 1 in the direction of the preferably metallic sealing seat 51 of the nozzle body 5.

The valve housing 2 further comprises a medium space 21 which is supplied with a medium to be dosed, for example hydrogen, via one or more medium supply channels 22.

According to the invention, an elastomer element 7 of disk-shaped design is arranged on the end face 11 of the armature 1 facing the seal seat 51. As can be seen in fig. 2 and the corresponding exploded view in fig. 3, the first side 110 of the elastomer element 7 in this case bears in a surface-like manner against the end face 11 of the armature 1 facing the seal seat 51. With the nozzle 105 closed, a second side 115 of the elastomer element 7 opposite the first side 110 rests on the seal seat 51. In fig. 2 and 3, the same reference numerals are given to the same elements as in fig. 1.

With the valve 100 closed as shown in fig. 1, 2 and 4, the electromagnet group 6 is currentless and the armature 1 is pressed by the spring 9 against the sealing seat 51. As a result, the end face 11 of the armature 1 bears against the seal seat 51 via the elastomer element 7 and thus separates the medium space 21 from the nozzle 105. In this state, no media is dispensed through the valve 100. To open the valve 100, the electromagnet group 6 is energized, causing the armature 1 to lift from the sealing seat 51 against the force of the spring 9 and release the nozzle 105. In this state, the medium or reagent in the medium space 21 is dispensed through the nozzle 105.

With the nozzle 105 closed, the elastomeric element 7 completely covers the sealing seat 51. If the surface of the sealing seat 51 is circular, the elastomer element 7 must also be at least circular and have a diameter at least corresponding to the diameter of the sealing seat 51. Alternatively, the elastomer element 7 can be configured as a disk, preferably a circular disk, without an opening in the region of the seal seat 51, the diameter of which disk corresponds at least to the diameter of the seal seat 51 and completely covers the seal seat 51 or the nozzle 105 with the nozzle 105 closed.

Since the elastomer element 7 is arranged on the armature 1, it only comes into contact with the seal seat 51 when the nozzle 105 is closed. In the present example, the elastomer element 7 is connected to the armature 1 in a non-positive and/or positive manner. The corresponding fastening of the elastomer element 7 to the armature 1 can take place, for example, by means of a clamping sleeve 8. For this purpose, the armature 1 comprises, at its end facing the end face, a radial recess 12 facing the seal seat 51, for receiving a hollow cylindrical clamping sleeve 8, preferably of metal. The clamping sleeve 8 has a first projection 150 on its end facing the seal seat 51, which first projection faces the end face 11 of the armature 1 and grips the latter in the edge region of the elastomer element 7 at the end face 11 of the armature. The clamping sleeve 8 thus clamps the elastomer element 7 between the first projection 150 and the end face 11 of the armature 1 and clamps it tight. For a particularly stable clamping connection, the first projection 150 can grip the end face 11 at a plurality of locations in the region of the elastomer element 7. According to a simple design variant, the first projection 150 can be annular at least in sections. According to the present example, the first protrusion 150 is configured in a circular ring shape. Here, the inner diameter of the first projection 150 is selected to be larger than the outer diameter of the seal holder 51. In this way, the elastomer element 7 clamped by the first projection 150 projects beyond the sealing seat 51 and is responsible for a reliable sealing of the nozzle 105 against the medium space 21.

In order to achieve a reliable sealing of the nozzle 105 against the medium space 21, on the one hand, the diameter DA of the armature 1 in the region of the radial recess 12 should correspond to the inner diameter DI of the clamping sleeve 8 outside the first projection 150, so that the clamping sleeve 8 is largely free of play and is received in the radial recess in the clamped state. Furthermore, the inner height h8 of the clamping sleeve 8, which does not comprise the first projection 150, is at its maximum, preferably should not correspond exactly to the height h1 of the radial recess 12 of the armature 1 plus the height h7 of the elastomer element 7, so that the elastomer element 7 is clamped between the first projection 150 and the end face 11 with clamping when the clamping sleeve 8 is pushed into the radial recess 12 to the greatest extent. In this way, the elastomeric element 7 can be sealingly clamped or compressed between the first projection 150 and the end face 11 of the armature 1. The corresponding pressing also ensures that the sealing function of the sealing seat 51 is present in any case, even if there is no contact between the end face 11 of the armature 1 and the armature-side face portion 73 of the elastomer element 7. The armature-side face portion 73 is a component of the first side 110 of the elastomer element 7.

According to one embodiment of the invention, as shown in fig. 1 to 4, the elastomer element 7 may comprise a flange 72, in particular an at least partially annular flange. An alternative embodiment of the elastomer element 7 without the flange 72 is indicated by the dashed line 165 in the exploded view according to fig. 3.

In the embodiment described below, the flange 72 is configured in the form of an O-ring in a circular ring shape. The flange 72 is an integral part of the elastomer element 7. The flange may extend in the direction of the end face 11 and/or in the direction of the nozzle body 5. In the present example, the flange 72 extends not only in the direction of the end face 11 but also in the direction of the nozzle body 5. In the present example, the flange 72 is arranged on the elastomeric element 7 concentrically with the nozzle 105 and with the seal seat 51. The inner diameter of the ring formed by the flange 72 is greater than the outer diameter of the seal seat 51. According to fig. 1 to 4, the flange 72 is thus clamped between the first projection 150 and the end face 11 of the armature 1.

As can be seen from fig. 1 to 4, the collar 72 can be received on one side in a corresponding first recess 120 on the end face 11 of the armature 1. The first recess 120 is designed in accordance with the armature-side geometry of the flange 72, in particular at least in sections in the form of a circular ring. In this example, the first recess 120 has an annular geometry for receiving the annular flange 72.

In this case, it can also be seen from fig. 1 to 4 that the flange 72 can be received on the other side in a corresponding second recess 82 on the first projection 150 of the clamping sleeve 8. In this case, the second recess 82 is configured corresponding to the nozzle-side geometry of the flange 72, in particular at least in sections in the form of a circular ring. In the present example, the second recess 82 has an annular geometry for receiving the annular flange 72.

Due to the above-mentioned selected height h1 of the radial recess 12 and the inner height h8 of the clamping sleeve 8, the flange 72 is received in the

recesses

120, 82 in the clamped condition.

Since the collar 72 is received in the first recess 120 and the second recess 82 in the clamped condition, the sealing effect of the elastomer element 7 between the medium space 21 and the nozzle 105 in the closed condition of the valve 100 is further improved, and the elastomer element 7 is additionally prevented from coming loose from the end face 11 of the armature 1. In particular, an improved seal is produced between the medium space 21 and the armature-side surface portion 73 of the elastomer element 7 having the diameter dQ in the cross section of the collar 72, in order to thus prevent said surface portion 73 from becoming detached from the end face 11.

If the flange is formed only in the direction of the end face 11 of the armature 1, it is sufficient to provide the first recess 120, and the second recess 82 can be omitted. If the flange is configured only in the direction of the first projection 150, it is sufficient to provide the second recess 82, and the first recess 120 may be omitted. Similar to the case where the flange 72 is not provided on the elastomer element 7, a recess to receive the flange 72 is in principle not required. However, the sealing effect and the stable arrangement of the elastomer element 7 provided with the flange 72 on the end face 11 of the armature 1 are improved by the provision of the

recesses

120, 82.

According to fig. 1 to 4, the sealing seat 51 optionally has a projection 130 on its end face 155 facing the armature 1, which projection presses into the elastomer element 7 when the nozzle 105 is closed and thus ensures a more reliable seal with respect to the medium space 21 on the nozzle side. In this case, the projection 130 can again be at least in sections of circular configuration. In the present example, the projection 130 is configured as a circular ring and is arranged concentrically with the nozzle 105.

Fig. 4 shows an alternative embodiment with regard to the design of the clamping sleeve 8, wherein the same reference numerals denote the same elements as in fig. 1 to 3. The clamping sleeve according to fig. 4 comprises, on its first projection 150, a second projection 83 facing the nozzle body 5, which second projection, when the nozzle 105 is closed, bears against the nozzle body 5 and thus delimits the penetration depth of the projection 130 into the elastomer element 7. In this way, local strains within the elastomeric element 7 may be avoided or at least reduced, so that the strength of the elastomeric element 7 is compromised as little as possible. In this case, a part of the effective closing force fscliess formed by the spring force of the spring 9 and the generated pneumatic force is received by the second projection 83.

According to the exemplary embodiment of fig. 1 to 4, the valve with its components is designed rotationally symmetrically with respect to the longitudinal axis 160.

According to fig. 1 and 2, a medium pressure or an average pressure pM exists in the medium space 21, which medium pressure or average pressure may lie in a pressure range of 10bar to 25bar in the case of a valve 1 configured as a mobile hydrogen dosing valve in a fuel cell system. With the valve 100 closed, the mean pressure pM acts on the elastomeric element 7 on the nozzle side on a first sealing surface portion 74 which lies outside the sealing seat cross section formed by the projection 130 and having the diameter dD. The first sealing surface portion 74 is an integral part of the second side 115 of the elastomeric element 7.

A nozzle pressure pA, which in the hydrogen metering valve 1 corresponds to the anode pressure and is typically in the pressure range of 1.5bar to 2.5bar, is exerted on the second sealing surface portion 71 of the elastomer element 7 on the nozzle side in the sealing seat cross section. The second sealing surface portion 71 is likewise an integral part of the second side 115 of the elastomer element 7. Since the flange 72 of the elastomer element 7 is designed as an O-ring and delimits the elastomer element 7 outwards in this example and thus forms an edge (umanden) for it, a pressure is prevented from possibly building up between the end face 11 of the armature 1 and the elastomer element 7 on the armature side in the cross section of the O-ring 72 with the diameter dQ. In the closed state of the valve 100 and in the open state, therefore, there is always a pressure gradient at the elastomer element 7, which presses the elastomer element 7 against the end face 11 of the armature 1. This is the average pressure pM in case the valve 100 is open, and the nozzle pressure pA in case the valve 100 is closed.

As shown in fig. 2, an adhesion force Fk may occur at the contact point between the second sealing surface portion 71 of the elastomer element 7 and the projection 130 of the seal holder 51 when the valve 100 is opened by the lifting of the armature 1, which adhesion force is always opposed to an aerodynamic force Fpm that is significantly greater than the adhesion force Fk. Thus, the armature-side face portion 73 of the elastomer element 7 is prevented from being released from the end face 11 of the armature 1 when the valve 100 is opened.

In the open state of the valve 100, a throughflow takes place from the medium supply channel 22 or media supply channels 22 through the medium space 21 via the sealing seat 51 and the nozzle 105 into the anode region of the mobile fuel cell system. In this state, the pressure acting on the second sealing surface portion 71 of the elastomeric element 7 in the sealing seat cross-section increases to the level of the average pressure pM.

Claims

1. A media dosing valve (100) having: a dosing opening (105), in particular a nozzle; a media supply channel (22); a medium space (21); and a valve closing element (1) for opening and closing the dosing opening (105) relative to the medium space (21), wherein a sealing seat (51) is provided against which the valve closing element (1) rests when the metering opening (105) is closed, wherein an elastomer element (7) is arranged on an end face (11) of the valve closing element (1) facing the sealing seat (51), characterized in that the elastomer element (7) is designed in a disk-shaped manner, a first side (110) of the elastomer element (7) bearing in a surface manner against an end face (11) of the valve closing element (1) facing the sealing seat (51), wherein a second side (115) of the elastomer element (7) opposite the first side (110) rests on the sealing seat (51) with the dosing opening (105) closed.

2. Medium dosing valve (100) according to claim 1, characterised in that the elastomeric element (7) completely covers the sealing seat (51) with the dosing opening (105) closed.

3. Medium dosing valve (100) according to any of the preceding claims, characterized in that the elastomeric element (7) completely covers the dosing opening (105) in case the dosing opening (105) is closed.

4. Medium dosing valve (100) according to any of the preceding claims, characterised in that the elastomer element (7) bears against the sealing seat (51) only in the case of a closed dosing opening (105).

5. Medium metering valve (100) according to one of the preceding claims, characterized in that the elastomer element (7) is connected with the valve closing element (1) in a force-locking and/or form-locking manner.

6. Medium metering valve (100) according to claim 5, characterized in that the elastomer element (7) is fastened on the valve closing element (1) by means of a clamping sleeve (8).

7. Media dosing valve (100) according to claim 6, characterised in that the valve closing element (1) comprises a radial recess (12) for receiving the clamping sleeve (8).

8. Medium dosing valve (100) according to any of the preceding claims, characterized in that the elastomer element (7) comprises a flange (72), in particular an at least partially circular ring-shaped flange, in particular a flange in the form of an O-ring.

9. Medium dosing valve (100) according to claim 8, characterised in that the flange (72) is arranged concentrically with the dosing opening (105).

10. Medium dosing valve (100) according to claim 8 or 9, characterised in that the diameter of the flange (72) is larger than the diameter of the sealing seat (51).

11. Medium metering valve (100) according to one of the claims 8 to 10, characterized in that a first recess (120), in particular at least in sections a circular ring shape, is arranged in the valve closing element (1) for receiving the flange (72), in particular in the clamped condition.

12. Medium dosing valve (100) according to one of the claims 8 to 11 when depending on claim 7 or 8, characterised in that a second, in particular at least partially circular ring-shaped, recess (82) is arranged on the clamping sleeve (8) in a first projection (150) facing the end face (11) of the valve closing element (1), said second recess being intended to receive the flange (72), in particular in the clamped condition.

13. Medium dosing valve (100) according to one of the claims 8 to 12 when depending on claim 6 or 7, characterised in that the inner height (h8) of the clamping sleeve (8) is at its maximum, preferably not exactly corresponding to the height (h1) of the radial recess (12) of the valve closing element (1) plus the height (h7) of the elastomer element (7).

14. Medium dosing valve (100) according to any of the preceding claims, characterised in that the sealing seat (51) has a projection (130), in particular an at least sectionally annular projection (130), on its end face (155) facing the valve closing element (1), which is pressed into the elastomer element (7) with the dosing opening (105) closed.

15. Medium dosing valve (100) according to claim 14 as far as dependent on any of claims 6, 7, 12 or 13, characterised in that the clamping sleeve (8) comprises a second projection (83), in particular at least partially circular ring-shaped, on its side facing away from the end face (11) of the valve closing element (1), which second projection rests on a dosing opening body (5) surrounding the dosing opening (105) with the dosing opening (105) closed, for limiting the penetration depth of the projection (130) into the elastomer element (7).