JP2010261591A - Gas valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust the amount of fuel with sufficient accuracy regardless of a change in pressure applied state. <P>SOLUTION: A flexible separation wall 28, which is gas-tightly positioned and fixed to a closing body 16 and a valve housing 11, gas-tightly separates a rear side chamber 29 situated on the rear side of the closing body 16 opposite to a sealing seat 17 from a valve chamber 12 and at least one passage 30 for connecting the rear side chamber 29 with a first chamber opening 13 is worked in the closing body 16. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is a metering valve for a gas valve, in particular a gaseous medium, provided with a valve chamber formed in the valve housing, the valve chamber having two chamber openings. And the first chamber opening is annularly surrounded by the valve seat, and a closing body disposed in the valve chamber is provided, and the closing body is mounted on the valve seat. It relates to a type having a sealing seat which can be lifted from the valve seat.

  Known gas valves for metering gaseous fuels used in gas engines or fuel cell drives, such as natural gas, liquid gas or hydrogen (see German Offenlegungsschrift DE 19 05 721 A), are large In order to obtain a flow cross section with a short switching and response time, it is designed as a flat seat valve with a flat valve seat and a closure with a flat sealing element. The sealing element is pressed against the valve seat against the spring force of the valve opening spring acting on the sealing element by a valve closing spring acting on the closing element on the surface facing the valve seat. In order to open the valve, an axial force, which is formed by an electromagnet and exceeds the closing force of the valve closing spring, acts on the closing body.

  When opening the gas valve, the electromagnet and valve are used to open the valve between the upstream pressure on the inlet side of the valve seat and the downstream pressure on the outlet side, coupled with the pneumatically effective surface of the seal element. A pneumatic opening force is formed that strongly changes the opening force provided by the opening spring. As a result of this, the amount of lifting movement of the sealing element from the valve seat, i.e. the valve stroke, is significantly dependent on the amount of upstream and downstream pressure, so that the fuel metering when the pressure situation changes is sufficiently accurate. Don't be.

German Patent Application Publication No. 19905721

  The object of the invention is therefore to improve the gas valve of the type mentioned at the outset so that fuel metering can be performed sufficiently accurately even when the pressure situation changes.

  In order to solve this problem, in the gas valve of the present invention, the backside chamber in which the flexible separating wall fixed in a gastight manner to the closing body and the valve housing is located on the backside of the closing body opposite to the seal seat. In a gastight manner from the valve chamber, and the closure is machined with at least one passage connecting the back chamber to the first chamber opening.

  According to an advantageous embodiment of the gas valve according to the invention, the surface section separating the back chamber on the back side of the closure opposite the valve seat is surrounded by a sealing seat on the front side of the closure facing the valve seat. The separating wall is fixed to the closure so that it is approximately dimensioned to the surface section.

  According to an advantageous embodiment of the gas valve according to the invention, the separating wall is made of a flexible material and is gastightly fixed to the closure and the chamber wall of the valve chamber, respectively.

  According to an advantageous embodiment of the gas valve according to the invention, the separating wall is a bellows, which at the end of one of the bellows is gastight, advantageously on the back side of the closing body, opposite the valve seat. It is fixed in a material connection and is gastight, preferably in a material connection, at the other bellows end to the chamber wall of the valve chamber located opposite the valve seat.

  According to an advantageous embodiment of the gas valve of the invention, the bellows constitutes a spring element with a spring force acting in the bellows axial direction.

  According to an advantageous embodiment of the gas valve according to the invention, the separating wall is a hollow cylinder with a concave wall or an inflatable smooth wall which is gastight by a closing body at one cylinder end. Closed and fixed at the other cylinder end in a gastight manner, preferably in a material connection, to the chamber wall of the valve chamber located opposite the valve seat.

  According to an advantageous embodiment of the gas valve according to the invention, the separating wall is a rigid hollow cylinder, which is gas-tightly closed by a closing body at one cylinder end thereof, The other cylinder end opposite the body is slidably and gas tightly contained in the valve housing.

  According to an advantageous embodiment of the gas valve according to the invention, the separating wall is a diaphragm, which is gastight, preferably material, on the back surface of the closing body opposite the valve seat at the inner diaphragm edge. It is connectedly fixed and is gastight, preferably material-connected, to the chamber wall at the outer diaphragm edge.

  According to an advantageous embodiment of the gas valve according to the invention, the separating wall is made of metal or plastic.

  According to an advantageous embodiment of the gas valve of the invention, the closing body is formed in a disc shape and the valve seat is formed in an annular shape.

  According to an advantageous embodiment of the gas valve of the invention, the closure has a spherical shape with a spherical surface facing the valve seat, and the valve seat has a conical shape.

  According to an advantageous embodiment of the gas valve of the invention, the closing body is fixed to the free end of the valve needle which can be operated against the spring force of the valve closing spring by means of an actuator.

  The gas valve according to the present invention having the features of claim 1 is characterized in that a closed body and a valve housing are gas-tightly connected by a flexible separating wall and separated from each other by a separating wall and the closing body. By providing a connection passage in the closure body that forms a connection with the chamber opening of the chamber, an equal gas pressure is formed on both sides of the closure body, i.e. an equal pressure between the upstream pressure and the downstream pressure applied to the closure body. Has the advantage that a controlled valve is realized. Also, the surface section that partitions the back chamber on one side of the closure is dimensioned to approximately the same size as the surface section partitioned by the seal seat on the other side of the closure facing the valve seat. As described above, the separation wall is fixed to the closing body, so that the axial forces acting in the opening and closing directions on the end surfaces of the closing body opposite to each other, which are loaded with equal pressure, have the same magnitude. Cancel each other during the action of the axial force on As a result, the valve stroke when the valve is opened does not depend on the pressure situation formed in the valve chamber, and the fuel metering acts exclusively on the closing body, for example, the stroke generated electromagnetically or piezoelectrically. High accuracy can be achieved by setting the force.

  By means of the other claims, advantageous configurations and embodiments of the gas valve according to claim 1 are possible.

  According to an advantageous aspect of the invention, the flexible separating wall can be realized in different ways, for example it can be realized by a diaphragm fixed to the closing body and the valve chamber, or the closing body and the valve. May be realized by a bellows fixed to the housing, or a dentable or bulging one end face end fixed to the closure and the other end face end fixed to the chamber wall of the valve chamber It may be realized by a hollow cylinder with a smooth wall shape, which is fixed to the closing body at one cylinder end and slidable in the valve housing at the other cylinder end opposite to this cylinder end It may also be realized by a rigid hollow cylinder housed in a gas tight manner. The separation wall may be made of metal or plastic.

It is a longitudinal cross-sectional view of a gas valve. It is a longitudinal cross-sectional view of the 1st another Example of a gas valve. It is a longitudinal cross-sectional view of the 2nd another Example of a gas valve. It is a longitudinal cross-sectional view of the 3rd another Example of a gas valve. It is a longitudinal cross-sectional view of the gas valve provided with the changed closure body.

  In the following, embodiments for carrying out the invention will be described in detail with reference to the drawings.

  The gas valve shown schematically in part in longitudinal section in FIG. 1 is for metering gaseous media used in gas engines, such as natural or liquid gas or hydrogen used in fuel cell drives. work. The gas valve has a valve housing 11. The valve housing 11 includes a valve chamber 12 formed therein. The valve chamber 12 has at least two chamber openings 13, 14. Of these chamber openings 13, 14, the first chamber opening 13 is annularly surrounded by a flat valve seat 15. A gaseous medium flows from the reservoir into the valve chamber 12 via at least one of the chamber openings, for example both chamber openings 14, and a metered amount of gas via the other chamber opening, for example chamber opening 13. Shaped medium flows to the gas engine or fuel cell drive. However, the chamber openings 13, 14 can interchange their inflow and outflow functions, whereby a reservoir is connected to the first chamber opening 13, and a gas is connected to both second chamber openings 14. An engine or a fuel cell driving device is connected. The first chamber opening 13 and the valve seat 15 surrounding the first chamber opening 13 are formed in the valve body 18. The valve body 18 is gas-tightly inserted into an end portion opened on the end face side of the valve housing 11. A closing body 16 is arranged in the valve chamber 12. The closing body 16 is formed with a seal seat 17 that can be mounted on the valve seat 15 to close the chamber opening 13 and can be lifted from the valve seat 15 to open the chamber opening 13. In the valve closed state, the seal seat 17 and the valve seat 15 are located on top of each other with approximately one circular line or a very narrow annular surface. In the embodiment of FIG. 1, the closing body 16 formed in a disk shape or a plate shape is fixed to a valve needle 19. The valve needle 19 is gas-tightly guided through a closing piece 20 that closes the valve chamber 12 on the side opposite to the valve body 18. A valve closing spring 21 acts on one of the valve needles 19, and an actuator 22 acts on the other. The valve closing spring 21 presses the closing body 16 against the valve seat 15 with its sealing surface 17 via the valve needle 19, and the actuator 22 resists the spring force of the valve closing spring 21 when operating, Lift from the valve seat 15 by an adjustable stroke. In the illustrated embodiment, the actuator 22 comprises a solenoid coil 25, a solenoid core 23, and a solenoid plunger 24 rigidly coupled to the valve needle 19, guided axially within the solenoid core 23. Electromagnet. Alternatively, the actuator may comprise a piezoelectric module for driving the valve needle 19. In order to guide the valve needle 19 through the closing piece 20 in a gas tight manner, a seal member 27 is arranged in an annular groove 26 cut out in the closing piece 20. The seal member 27 is pressed against the valve needle 19.

In order to obtain an optimum valve function for gas metering, one is a flexible separating wall 28 which is fixed on the one hand to the closure body 16 and on the other hand to the valve housing 11. Thereby, the separating wall 28 gas-separates the backside chamber 29 located on the back side opposite to the sealing surface 17 of the closing body 16 from the valve chamber 12, and the other is a passage to the closing body 16. 30 has been processed. This passage 30 connects the back side chamber 29 to the first chamber opening 13. The separating wall 28 is made of a flexible material, such as metal or plastic, and is gas tightly secured not only to the closure 16 but also to the chamber wall of the valve chamber 12 by a material-connective connection such as welding. Yes. In this case, the separation wall 28, the closure body 16, the back side opposite to the valve seat 15, the surface segment A _R partitioning the rear chamber 29 with the separation wall 28, the closure 16, facing the valve seat 15 It is fixed in position on the closure 16 so that on the front side it is dimensioned approximately equal to the surface section _AD surrounded by the seal seat 17.

  In the embodiment of FIG. 1, a corrugated tube or bellows 31 is used as the separation wall 28. One bellows end portion (tube end portion) of the bellows 31 is fixed in material connection, for example, welded to the closing body 16 and the back surface of the closing body 16 opposite to the seal seat 17. The end of the bellows is fixed in material connection, for example welded, to the chamber wall 121 located opposite the valve seat 15. Alternatively, one end of the bellows can be fixed to the peripheral surface of the disc-shaped closing body 16, so that the bellows 31 is completely gas-tight by the closing body 16 on one end face side. It is closed. This passage 30 through the closure body 16 applies equal pressure to both end faces of the closure body 16 and thus ensures that the amount of gas pressure formed in the valve chamber 12 does not affect the valve stroke. Has been. As a result, the stroke distance of the closing body 16 when the valve is opened is defined exclusively by the amount of current supplied to the actuator 22.

  The corrugated tube or bellows 31 is advantageously formed as a spring element with a spring force acting in the bellows axial direction (tube axial direction). This allows the function of the valve closing spring 21 to be taken over by the corrugated tube or bellows 31 and saves a separate valve closing spring.

  The alternative embodiment of the gas valve shown in FIGS. 2 to 4 differs from the previously described embodiment shown in FIG. 1 only by the different configuration of the flexible separating wall 28.

  In FIG. 2, the flexible separation wall 28 is realized by the diaphragm 32. An outer diaphragm edge of the diaphragm 32 is fixed to a chamber wall 122 extending over the entire circumference in a material connection, for example, by welding, and an inner diaphragm edge of the diaphragm 32 is a valve seat 15 of the closing body 16. It is fixed to the back surface opposite to the material, for example, by welding. Here again, the surface of the closing body 16 on the back side opposite to the valve seat 15 and the diaphragm 32 together with the diaphragm 32 is surrounded by the sealing seat 17 on the front side of the closing body 16 facing the valve seat 15. The axial force acting on the closing body 16 when the valve is opened from the back side chamber 29 and the valve chamber 12 becomes equal to each other and cancels each other out.

  In the embodiment of FIG. 3, the flexible separation wall 28 is realized by a hollow cylinder 33 having a smooth wall shape. The hollow cylinder 33 can be recessed or swelled during the stroke movement of the closing body 16. The closing body 16 is inserted in a shape connection in the end of the hollow cylinder 33 facing the valve seat 15, so that the closing body 16 is inserted into the backside chamber 29 and the first chamber when the valve is opened. The end faces formed by the equal pressure formed in the valve opening 13 are again sized to approximately the same size. The end face of the hollow cylinder 33 opposite to the valve seat 15 is supported by the chamber wall 121 of the valve chamber 12 facing the valve seat 15 and is connected to the chamber wall 121 in a material connection. .

  In the embodiment of the gas valve shown in FIG. 4, a rigid hollow cylinder 34 is provided to realize a flexible separating wall 28 between the closing body 16 and the valve housing 11. The closing body 16 is also inserted into the end portion of one end surface of the hollow cylinder 34 in a shape-connected manner and in a gastight manner. The other end face end of the hollow cylinder 34 is slidably and gas tightly accommodated in the valve housing 11. For this purpose, the annular groove 35 is cut out in the chamber wall 122 extending over the entire circumference, and the seal ring 36 is inserted into the annular groove 35. This seal ring 36 is pressed against the hollow cylinder 34, which allows for the stroke movement of the closure body 16 in one part and the valve chamber 12 at the end of the open end face of the hollow cylinder 34. It is securely sealed against.

The gas valve partially shown in longitudinal section in FIG. 5 differs from the previously described gas valve shown in FIG. 1 solely by the different configurations of the closure 16 and the valve seat 15. The valve seat 15 that is also formed in the valve body 18 and surrounds the chamber opening 13 has a conical surface shape, and the closing body 16 has a spherical shape, thereby facing the valve seat 15. A seal seat 17 present on the surface of the spherical closure body and a conical valve seat 15 are located on top of each other along a circular line when the valve is closed. Again, corrugated tube or bellows 31 of the closure 16, the back side opposite to the valve seat 15 or the sealing seat 17, the surface segment A _R partitioning the rear chamber 29, of the closure 16, facing the valve seat 15 It is secured to the flat back surface of the closure 16 so that it is dimensioned approximately equal to the surface section _AD surrounded by a spherically shaped front side.

DESCRIPTION OF SYMBOLS 11 Valve housing 12 Valve chamber 13 1st chamber opening 14 2nd chamber opening 15 Valve seat 16 Closure body 17 Seal seat 18 Valve body 19 Valve needle 20 Closing piece 21 Valve closing spring 22 Actuator 23 Solenoid core 24 Solenoid plunger 25 Solenoid Coil 26 Annular groove 27 Seal member 28 Separation wall 29 Back side chamber 30 Passage 31 Bellows 32 Diaphragm 33 Hollow cylinder 34 Hollow cylinder 35 Annular groove 36 Seal ring 121 Chamber wall 122 Chamber wall A _D Surface section A _R Surface section

Claims (12)

  A gas valve, in particular a metering valve for a gaseous medium, is provided with a valve chamber (12) formed in the valve housing (11), the valve chamber (12) comprising two chambers An opening (13, 14) is provided, and the first chamber opening (13) of both chamber openings (13, 14) is annularly surrounded by the valve seat (15), and the valve chamber (12 ), And a sealing seat (17) which can be mounted on the valve seat (15) and lifted from the valve seat (15). A flexible separating wall (28) gastightly secured to the closure (16) and the valve housing (11), respectively, is provided on the sealing seat (17) of the closure (16). The back chamber (29) located on the back side opposite to Gas-tightly separated from the bar (12), the closure (16) being machined with at least one passage (30) connecting the back chamber (29) to the first chamber opening (13) Features a gas valve. The surface section (A _R ) partitioning the back chamber (29) on the back side opposite the valve seat (15) of the closure (16) is on the front side of the closure (16) facing the valve seat (15). The separating wall (28) is fixed to the closure (16) so as to be dimensioned approximately equally to the surface section (A _D ) surrounded by the sealing seat (17). Gas valve.   Separation wall (28) is made of a flexible material and is gastightly secured to the closure (16) and the chamber wall (121; 122) of the valve chamber (12), respectively. The gas valve described.   The separation wall (28) is a bellows (31), which is advantageously gastight on the back of the closure (16) opposite the valve seat (15) at one bellows end. Is connected in a gas-tight manner to the chamber wall (121) of the valve chamber (12) facing the valve seat (15) at the other bellows end, preferably in a material-connective manner. The gas valve according to claim 3, wherein the gas valve is fixed to the gas valve.   5. The gas valve according to claim 4, wherein the bellows (31) constitutes a spring element with a spring force acting in the bellows axial direction.   The separation wall (28) is a hollow cylinder (33) that can be recessed or swelled, and is closed tightly by a closing body (16) at one cylinder end. Gas-tight, preferably material-connected, to the chamber wall (121) located opposite the valve seat (15) of the valve chamber (12) at the other cylinder end. Item 4. The gas valve according to Item 3.   The separation wall (28) is a rigid hollow cylinder (34), the hollow cylinder (34) being gas tightly closed by a closing body (16) at one cylinder end, the closing body 4. The gas valve according to claim 3, which is slidably and gastightly accommodated in the valve housing (11) at the other cylinder end opposite to (16).   The separation wall (28) is a diaphragm (32), which is advantageously gastight on the inner diaphragm edge on the back of the closure (16) opposite the valve seat (15). 4. The gas valve according to claim 3, wherein the gas valve is fixed in material connection and is gastight, advantageously materially fixed to the chamber wall (122) at the outer diaphragm edge.   Gas valve according to any one of the preceding claims, wherein the separation wall (28) is made of metal or plastic.   The gas valve according to any one of claims 1 to 9, wherein the closing body (16) is formed in a disk shape, and the valve seat (15) is formed in an annular shape.   The closure (16) has a spherical shape with a spherical surface facing the valve seat (15), and the valve seat (12) has a conical shape. The gas valve according to any one of the above.   The closure (16) is secured to the free end of the valve needle (16) operable by the actuator (22) against the spring force of the valve closing spring (21). The gas valve according to any one of claims.

Images