CN111373180A

CN111373180A - Metering valve for controlling a gaseous medium

Info

Publication number: CN111373180A
Application number: CN201880074030.3A
Authority: CN
Inventors: H-C·马格尔
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-11-15
Filing date: 2018-09-12
Publication date: 2020-07-03
Also published as: JP2021501292A; JP6968275B2; WO2019096461A1; DE102017220383A1

Abstract

The invention relates to a metering valve (100) for controlling a gaseous medium, in particular hydrogen, having a valve housing (12), wherein a longitudinally movable flat closing element (2) is arranged in the valve housing (12), which element interacts with a valve seat (4) for opening and closing an opening cross section from an inlet region (7) into a flow opening (21), wherein the valve seat (4) is designed as a circumferential sealing edge (20) on a seat surface (1a) of a nozzle (1) received in the valve housing (12) and fixedly connected thereto, which seat surface faces the closing element (10), and wherein the seat surface (1a) of the nozzle (1) is designed conically, wherein the closing element (2) has a radial projection (19) on the circumferential sealing edge (20) in the closed position of the metering valve (100), wherein the radial projection (19) delimits the maximum conical seat surface (2) of the closing element (2) on the seat surface (1a), wherein the angular extent of the conical seat surface (β) is within the range of 172 degrees.

Description

Metering valve for controlling a gaseous medium

Technical Field

The invention relates to a metering valve for controlling a gaseous medium, in particular hydrogen, for example for use in a vehicle having a fuel cell drive.

Background

DE 102012204565 a1 describes a metering valve for controlling gaseous media, in particular hydrogen, which is designed as a proportional valve, wherein the proportional valve comprises a nozzle body, a closing element and an elastic sealing element. At least one through-flow opening is formed in the nozzle body, which can be released or closed at the valve seat by a closing element. In this case, the elastic sealing element seals against the valve seat.

During normal operation of the proportional valve, particularly when the metering valve is used in the anode region of a fuel cell system, frequent opening and closing processes occur. Additional switching processes may also be desirable in order to optimize the scavenging process in the anode path of the fuel cell or in order to operate the ejector pump optimally in the fuel cell assembly. However, frequent opening and closing of the proportional valve leads to wear on the valve seat and tilting of the closing element relative to the valve seat, since angular tolerances may occur between the closing element and the valve seat. This in turn has a negative effect on the sealing of the entire proportional valve.

Disclosure of Invention

In contrast, the metering valve according to the invention for controlling a gaseous medium, in particular hydrogen, has the following advantages: the tightness on the valve seat is ensured even with frequent opening and closing processes of the metering valve.

In addition, the seat surface of the nozzle is conically formed, wherein the closing element has a radial projection on the circumferential sealing edge in the closed position of the metering valve, the radial projection, in the maximally formed inclined state of the closing element, delimits the maximally inclined position of the closing element on the seat surface of the nozzle, wherein the opening angle β of the conical seat surface lies in the value range between 172 ° and 178 °.

With the metering valve according to the invention, a uniform force distribution in the closing element is achieved due to the lowered seat surface even if there is an angular error between the valve seat and the closing element, which in turn leads to an improved sealing.

In a first advantageous development, it is provided that the radial projection extends from the center of the circumferential sealing edge to the outer circumferential edge of the closing element and has a width X of 0.2mm to 2mm, preferably 0.5mm to 1 mm. Advantageously, the circumferential sealing edge of the nozzle has a height R of between 0.04mm and 0.2mm, preferably 0.1 mm. The sealing edge can thus advantageously be inserted with little force into an elastic sealing element arranged between the valve seat and the closing element, so that in the additional inclined position of the closing element and in the additional inclined position of the bearing surface of the radial projection on the nozzle seat surface, a high degree of tightness on the valve seat and thus an optimal functional manner of the metering valve are ensured.

In a further embodiment of the invention, it is advantageously provided that the closing element is movable longitudinally by means of an electromagnet and an electromagnetic armature operatively connected to the closing element. The gaseous medium can thus be controlled by means of a metering valve.

In an advantageous embodiment, it is provided that an inlet channel is formed in the valve housing radially with respect to the longitudinal axis of the metering valve, through which inlet channel an inlet region of the metering valve can be filled with the gaseous medium.

The metering valve is advantageously configured as a proportional valve and is preferably suitable for controlling the supply of hydrogen to the anode region of the fuel cell in a fuel cell assembly. The advantage is that the pressure fluctuations in the anode path are small and the operation is quiet.

Drawings

In the drawing, an embodiment of a metering valve according to the invention for controlling the gas supply, in particular the hydrogen supply, to a fuel cell is shown. The attached drawings are as follows:

figure 1 shows an embodiment of the metering valve of the invention in longitudinal section,

figure 2 shows an enlarged detail of the inventive metering valve of figure 1 in the region of the valve seat in longitudinal section,

fig. 3 shows an enlarged detail of the inventive metering valve of fig. 1 in the region of the valve seat in the event of an inclination of the closing element on the valve seat.

Components having the same function are denoted by the same reference numerals.

Detailed Description

Fig. 1 shows an embodiment of a metering valve 100 according to the invention in longitudinal section. The metering valve 100 has a valve housing 12, in which an inner chamber 26 is formed. Disposed in the interior 26 is an electromagnet 130 comprising an electromagnetic coil 13, an inner pole 10 and an outer pole 11. The inner pole 10 and the valve housing 12 are connected by a spacer sleeve element 14 made of a non-magnetic material.

Furthermore, an armature 6, which carries a rod element 5 and can be moved back and forth, is arranged in an armature chamber 9, which is included in the inner chamber 12, wherein the rod element 5 is fixedly connected to the magnet armature 6 and is received and guided both in a slot 27 of the inner pole 10 and in a slot 28 of the valve housing 12. The armature 6 is designed as a plug-in armature and is received in its stroke movement in a notch 22 of the inner pole 10.

The valve housing 12 and the inner pole 10 delimit a spring chamber 8 into which a disk-shaped end 16 of the rod-shaped element 5 of the magnet armature 6 projects. A closing spring 15 is supported on a disk-shaped end 16 of the rod element 5, by means of which closing spring the magnet armature 6 is prestressed by means of the rod element 5. The end of the rod-shaped element 5 facing away from the closing spring 15 is fixedly connected to the flat closing element 2. The closing element 2 has an elastic sealing element 3 on its end facing away from the rod-shaped element 5 and is arranged in the inlet region 7 of the metering valve 100. The spring chamber 8 and the armature chamber 9 are fluidically connected to one another via a first connecting channel 24, while the armature chamber 9 and the inlet region 7 are fluidically connected to one another via a second connecting channel 25.

An inlet channel 31 is formed radially to the longitudinal axis 18 of the metering valve 100, through which the inlet region 7 of the metering valve 100 can be filled with the gaseous medium. The inlet region 7 is delimited by the valve housing 12 and also by the nozzle 1, in which a through-flow opening 21 is formed. A circumferential sealing edge 20, on which the valve seat 4 is formed, is formed on the conical seat surface 1a of the nozzle 1 facing the elastic sealing element 3 in the radial direction relative to the longitudinal axis 18 of the metering valve 100. The circumferential sealing edge 20 has a height R in the axial direction of between 0.04mm and 0.2mm, preferably 0.1 mm. In the closed position of the metering valve 100, the elastic sealing element 3 bears against the valve seat 4 as a result of the force loading of the closing spring 15, so that the connection between the inlet region 7 and the throughflow opening 21 is closed.

Function mode of the metering valve:

the metering valve 100 is designed here as a proportional valve. In the case of deenergization of the solenoid 13, the closing element 2 is pressed by the closing spring 15 against the valve seat 4, so that the connection between the inlet region 7 and the throughflow opening 21 is interrupted and no gas throughflow takes place.

If the magnet coil 13 is energized, a magnetic force acting on the magnet armature 6 is generated, which is in the opposite direction to the closing force of the closing spring 15, and this magnetic force is transmitted via the rod element 5 to the closing element 2, so that the closing force of the closing spring 15 is overcompensated (ü berkompenserren) and the closing element 2 is lifted from the valve seat 4, and the gas through-flow is released from the inlet region 7 in the direction of the through-flow opening 21.

The stroke of the closing element 2 can be adjusted by the magnitude of the current intensity on the magnetic coil 13. The higher the current intensity at the magnet coil 13, the greater the stroke of the closing element 2 and the higher the gas throughflow in the metering valve 100, since the force of the closing spring 15 is dependent on the stroke. If the current intensity at the magnet coil 13 decreases, the stroke of the closing element 2 also decreases, so that the gas throughflow is throttled.

If the current flow through the magnet coil 13 is interrupted, the magnetic force acting on the magnet armature 6 is reduced, so that the force acting on the closing element 2 by means of the rod element 5 is reduced. The closing element 2 moves in the direction of the throughflow opening 21 and is sealed against the valve seat 4 by means of the elastic sealing element 3. The gas throughflow in the metering valve 100 is interrupted.

Fig. 2 shows an enlarged detail of the inventive metering valve of fig. 1 in the region of the valve seat 4 in longitudinal section. In the closed position of the metering valve 100, the elastic sealing element 3 rests against the valve seat 4, wherein the circumferential sealing edge 20 dips into the elastic sealing element 3. Due to the conical seat surface 1a of the nozzle 1, the closing element 2 with the elastic sealing element 3 has a radial projection 10 which extends from the center of the circumferential sealing edge 20 to the outer circumferential edge 17 of the closing element 10 and has a width X of 0.2mm to 2mm, preferably 0.5mm to 1 mm.

The angular tolerance between the valve seat 4 and the elastic sealing element 3 may lead to tilting of the entire closing element 2 with the elastic sealing element 3, which is shown in fig. 3, the tilted state of the maximum configuration of the closing element 10 is shown here, the radial projection 19 delimits the maximum tilted position of the closing element 2 on the seat surface 1a of the nozzle 1, the opening angle β of the conical seat surface 1a lies in a value range between 172 ° and 178 °, in the tilted state of the maximum configuration of the closing element 2, the contact line 30 of the radial projection 19 with the seat surface 1a forms an angle α, which angle α corresponds to 180 ° - β, which angle α lies in a value range between 2 ° and 8 °, as a result of which, even if the closing element 2 is tilted, a sealing on the valve seat 4 can be achieved in the tilted state of the maximum configuration of the closing element 2.

Claims

1. A metering valve (100) for controlling a gaseous medium, in particular hydrogen, having a valve housing (12), wherein a longitudinally movable flat closing element (2) is arranged in the valve housing (12) and interacts with a valve seat (4) for opening and closing an opening cross section from an inlet region (7) into a flow opening (21), wherein the valve seat (4) is designed as a circumferential sealing edge (20) on a seat surface (1a) facing the closing element (10) of a nozzle (1) which is received in the valve housing (12) and is fixedly connected thereto, characterized in that the seat surface (1a) of the nozzle (1) is conically designed, wherein the closing element (2) has a radial projection (19) on the circumferential sealing edge (20) in the closed position of the metering valve (100), wherein the radial projection (19) delimits the maximum conical seat surface (2) of the closing element (2) on the seat surface (1a), wherein the angular extent of the conical seat surface (β ° lies in the range of the angular extent 178 ° and the seating surface (1a) is conical.

2. The metering valve (100) according to claim 1, characterised in that the radial projection (19) extends from the centre of the circumferential sealing edge (20) to the outer circumferential edge (17) of the closing element (2) and has a width X of 0.2mm to 2mm, preferably 0.5mm to 1 mm.

3. The metering valve (100) according to claim 1 or 2, characterised in that the circumferential sealing edge (20) of the nozzle (1) has a height R of between 0.04mm and 0.2m, preferably 0.1 mm.

4. The metering valve (100) according to one of the preceding claims, characterised in that an elastic sealing element (3) is arranged between the valve seat (4) and the closing element (2), which sealing element seals on the valve seat (4).

5. The metering valve (100) according to one of the preceding claims, characterised in that the closing element (2) is longitudinally movable by means of an electromagnet (130) and an electromagnetic armature (6) operatively connected to the closing element (2).

6. The metering valve (100) according to one of the preceding claims, characterised in that an inlet channel (31) is formed in the valve housing (12) radially to the longitudinal axis (18) of the metering valve (100), through which inlet channel the inlet region (7) of the metering valve (100) can be filled with a gaseous medium.

7. The metering valve (100) according to one of the preceding claims, characterised in that the metering valve (100) is configured as a proportional valve.

8. A fuel cell assembly having a dosing valve (100) according to one of the preceding claims for controlling the supply of hydrogen to a fuel cell.