Flow control valve with variably adjustable valve stroke

Abstract

The invention relates to a flow control valve (1) for regulating a gas flow, in particular a flow of gaseous fuel, from a gas inlet (2) to a gas outlet (3), preferably for use in internal combustion engines, in particular large engines, comprising a valve seat element (4) having at least one through-opening (5), a valve plate (6) which reversibly closes the through-opening (5) and which can be moved, by means of a drive group (8), between a flow control valve (1) closing position, in which a gas flow through the flow control valve (1) is blocked and the valve plate (6) rests against the valve seat element (4), and maximum open position, in which a gas flow from the gas inlet (2) to the gas outlet (3) is at a maximum and the valve plate (6) rests against a stop surface (19) of the drive group (8), the stroke (H) of the valve plate (6) between the closed position and the maximum open position being defined by the axial distance (D) between the valve seat element (4) and the stop surface (19) of the drive group (8) in the axial direction (A).

Description

[0001] R. 413708

[0002] - 1 -

[0003] Description

[0004] Flow control valve with variably adjustable valve stroke

[0005] Technical field

[0006] The invention relates to a flow control valve, which is arranged on the intake side, particularly on large engines, and meters gaseous fuel into the intake air.

[0007] State of the art

[0008] A key characteristic of a flow control valve is the cross-sectional area of ​​a flow opening, which limits the gas mass flow through the open valve and must be redesigned according to application and / or customer requirements. This geometric parameter is determined by the distance between the valve plate and the valve seat element when the valve is fully open, a distance known as the stroke, which, according to known solutions, can be set by an adjusting ring. In such solutions, the height of the adjusting ring is the determining factor for changing the opening cross-sectional area. Therefore, high accuracy requirements are placed on this geometric feature and the corresponding components.

[0009] According to the state of the art, the ring height is classified into several classes, each with a class width of 1 micrometer. Depending on the tolerances of the other components, an adjustment ring must be selected to determine the stroke and thus the opening cross-sectional area so that the customer-required gas mass flow rate is achieved. This necessitates constant overproduction and additional stockpiling of adjustment rings. The adjustment process itself also involves R. 413708

[0010] - 2 - Replacing an adjustment ring in the production of the flow control valve is a considerable time expenditure.

[0011] Disclosure of the invention

[0012] The flow control valve according to the invention, comprising the features of claim 1, and the method for adjusting the stroke of a flow control valve, comprising the features of claim 8, have the advantages that an adjusting ring, as known from the prior art, is eliminated, thereby reducing production costs and eliminating the need to stock adjusting rings in multiple height classes. This results in a significant cost advantage, since the manufacture and stocking of high-precision adjusting rings is very expensive. At the same time, it makes it possible to achieve a highly precise adjustment or calibration of the stroke in accordance with manufacturing specifications, even with moderate tolerance requirements for the components.

[0013] The flow control valve according to the invention for regulating a gas flow comprises a valve seat element with at least one flow opening, a valve plate reversibly closing the flow opening, and an actuator assembly that allows the valve plate to be adjusted between a closed position of the flow control valve, in which gas flow through the flow control valve is blocked and the valve plate rests against the valve seat element, and a maximum open position of the flow control valve, in which gas flow from the gas inlet to the gas outlet is at its maximum and the valve plate rests against a stop surface of the actuator assembly. The stroke of the valve plate between the closed position and the maximum open position is determined by an axial distance between the valve seat element and the stop surface of the actuator assembly in an axial direction.The valve plate may have recesses and / or channels by means of which a gas flow in an open position of the flow control valve can be influenced.

[0014] According to the invention, a plurality of balls are arranged radially circumferentially surrounding the valve plate, the balls contacting each other axially on both sides between a frustoconical ball contact surface of the valve seat element and that of a second ball contact surface, be- R. 413708

[0015] - 3 - are preferably arranged on the stop surface of the drive group. The frustoconical ball contact surface is chamfered in the radial direction, so that the distance between the frustoconical ball contact surface and the drive group increases radially outwards, with the balls bearing radially outwards against a frustoconical adjusting ring surface of an adjusting ring. The position specification "radially outwards" refers to the flow control valve. The adjusting ring is designed to be displaceable in the axial direction relative to the drive group, whereby the adjusting ring defines a radial position of the balls on the frustoconical ball contact surface of the valve seat element as a function of an axial position of the adjusting ring, so that the axial distance between the valve seat element and the stop surface of the drive group can be adjusted by axially displacing the adjusting ring.In other words, the radial position of the balls is adjustable and fixed by the adjusting ring, with the radial position of the balls determining the axial distance between the valve seat element and the stop surface of the actuator assembly. Thus, the axial distance between the valve seat element and the stop surface of the actuator assembly is indirectly adjustable via the adjustable adjusting ring.

[0016] The present invention makes particularly advantageous use of the fact that balls are readily and inexpensively available with sufficient accuracy. Furthermore, the adjustment of the stroke of the flow control valve is significantly simplified compared to the prior art, since the stroke is adjusted on the mounted flow control valve and no replacement of adjusting rings is necessary after installation.

[0017] Advantageous further developments of the flow control valve according to the invention are listed in the dependent claims.

[0018] In a first preferred embodiment of the flow control valve, the adjusting ring can be connected to the drive assembly by means of a threaded connection extending along the axial direction, such that the adjusting ring can be displaced axially relative to the drive assembly by rotating it relative to the drive assembly via the threaded connection. A threaded connection provides particularly simple axial adjustability of the adjusting ring. A threaded connection has the advantage that very precise displacement in the axial direction is possible. Ge- R. 413708

[0019] - 4 - Threaded connections can be manufactured without technical difficulties using a sufficiently fine thread pitch, ensuring a sufficiently fine ratio between rotational movement and axial displacement of the adjusting ring. A self-locking thread is particularly advantageous, as self-locking prevents unwanted axial displacement caused by axial loading of the adjusting ring during operation of the flow control valve. Threaded connections are known and proven for setting an axial position.

[0020] In a further, advantageously improved embodiment of the flow control valve, the adjusting ring can have a force-engagement means, preferably an engagement geometry for a tool, and more preferably a wrench flat for interaction with a wrench, by means of which the adjusting ring can be rotated relative to the drive assembly. Force-engagement means allow for particularly easy rotation of the adjusting ring, thus advantageously enabling precise rotation and therefore precise axial displacement of the adjusting ring. A wrench flat for interaction with a wrench is particularly advantageous because such a wrench flat is easy to manufacture. A corresponding tool is also easy and inexpensive to manufacture and / or procure.

[0021] In a further preferred embodiment of the flow control valve, the balls can be made of steel, preferably corrosion-resistant steel. Steel as a material for the balls has advantageously good material properties, particularly with regard to the strength and dimensional stability of the balls. Furthermore, steel is easy to machine, and the production of steel balls is well-known and technically well-established, resulting in a favorable price for steel balls. Corrosion-resistant steel also exhibits advantageously good resistance to aggressive media, such as fuels. Moreover, the use of corrosion-resistant steel prevents corrosion, which could adversely affect the dimensions of the balls and thus lead to a detrimental change in the stroke of the valve plate during operation of the flow control valve.

[0022] In a further preferred embodiment of the flow control valve, an opening cross-section R. 413708 can be formed in the maximum opening position of the flow control valve.

[0023] - 5 - cross-sectional area for a gas flow from the gas inlet to the gas outlet of 10 to 400 mm 2 preferably from 20 to 200 mm 2 , especially preferably from 40 to 80 mm 2The pressure conditions between the gas inlet and the gas outlet, and thus the flow velocity through the flow control valve, in conjunction with the opening cross-sectional area, determine the mass flow rate through the flow control valve. An opening cross-sectional area within the specified size range advantageously allows the flow of a gas mass flow rate through the flow control valve as is necessary for the use of the flow control valve in internal combustion engines, particularly in large engines. In this context, the opening cross-sectional area refers to the opening effective for the gas flow, which results from the valve plate, which can be variably lifted from the valve seat element, and the fixed flow opening in the valve seat element. The valve seat element can have several flow openings.

[0024] In a further preferred embodiment of the flow control valve, the valve can include a return element, preferably a spring, and particularly preferably a helical compression spring, for applying a closing force to the valve plate directed towards the valve seat element. A return element advantageously allows the use of a single-acting actuator assembly configured to move the valve plate to its maximum opening position. This advantageously simplifies the manufacturing and operation of the actuator assembly. In particular, a spring, preferably a helical compression spring, is known and proven as a return element in various valves. Over a long service life of the flow control valve, the return element allows a closing force to be applied without additional actuation. A spring advantageously operates reliably and without wear.Due to the operating characteristics of the flow control valve for metering fuel in an internal combustion engine, it follows that such a flow control valve is mostly closed during operation of the internal combustion engine, so that a restoring force can be applied by means of the restoring device during the majority of the operating time without the need for external energy.

[0025] In an advantageous further development of the flow control valve, the drive unit can include an electromagnet for electromagnetically lifting the valve plate from the valve seat element against the closing force of the return R. 413708

[0026] - 6 - The valve assembly comprises a mechanism in which the valve plate is preferably made of a ferromagnetic material. An electromagnet advantageously enables a very dynamic lifting of the valve plate from the valve seat element, since an electromagnet applies a driving force very dynamically. Furthermore, an electromagnet is advantageously suited for implementing control methods by which the gas mass flow through the flow control valve can be influenced and controlled precisely and with technical ease. Partial opening of the flow control valve is also possible by appropriately controlling the current to the electromagnet. An electromagnet as the actuator of the drive assembly is also advantageously designed without moving parts, which offers significant advantages with regard to wear and operational reliability of the drive assembly.A ferromagnetic valve plate interacts with the electromagnet in a particularly simple way, as no additional components are required. Alternatively, the valve plate can be made in multiple parts and include at least one magnetic component.

[0027] Furthermore, the invention also includes a method for adjusting the stroke of a flow control valve.

[0028] The inventive method for adjusting the stroke of a flow control valve relates to a flow control valve for regulating a gas flow, in particular a flow of gaseous fuel, from a gas inlet to a gas outlet, preferably for use in internal combustion engines, in particular large engines, comprising a valve seat element with at least one flow opening, a valve plate reversibly closing the flow opening, which is adjusted by means of a drive group between a closed position of the flow control valve, in which a gas flow through the flow control valve is blocked, and in which the valve plate rests against the valve seat element, and a maximum opening position of the flow control valve, in which a gas flow from the gas inlet to the gas outlet is at its maximum, and in which the valve plate rests against a stop surface of the drive group.The stroke of the valve plate between the closed position and the maximum open position is defined by an axial distance between the valve seat element and the stop surface of the actuator assembly in an axial direction. R. 413708.

[0029] - 7 -

[0030] According to the invention, the axial distance between the valve seat element and the stop surface of the drive assembly is adjusted by moving an adjusting ring in the axial direction relative to the drive assembly. A plurality of balls are arranged radially circumferentially surrounding the valve plate, with the balls being arranged in axial contact on both sides between a frustoconical ball contact surface of the valve seat element and a second ball contact surface, preferably the stop surface, of the drive assembly.The ball bearing surface on the valve seat element is chamfered in the radial direction, so that the distance between the frustoconical ball bearing surface on the valve seat element and the actuator assembly increases radially outwards. The balls bear radially outwards against a frustoconical adjusting ring surface of the adjusting ring, thus defining a radial position of the balls on the frustoconical ball bearing surface of the valve seat element depending on the axial position of the adjusting ring. The "radially outwards" position refers to the flow control valve.

[0031] The stroke adjustment is advantageously very simple, especially without the need to replace adjusting rings, as is known from the prior art. Using the method according to the invention, the stroke can be adjusted advantageously while the flow control valve is installed. No modification of the flow control valve is necessary to adjust the stroke.

[0032] For the sake of simplicity, reference is made to the effects disclosed in the device with regard to further advantageous effects of the method.

[0033] Advantageous further developments of the inventive method for adjusting the stroke of a flow control valve are listed in the dependent claims.

[0034] In a first preferred embodiment of the inventive method for adjusting the stroke of a flow control valve, the adjusting ring can be displaced axially relative to the drive assembly by rotating the adjusting ring relative to the drive assembly by means of a threaded connection. Threaded connections for converting a rotary movement into an axial displacement are known and proven as positioning elements. Rotating the adjusting ring provides an advantageously very simple manipulation of the adjusting ring for axial displacement, which is advantageously R. 413708

[0035] - 8 - This allows for a particularly simple manual adjustment of the stroke. Advantageously, the stroke adjustment can therefore also be carried out by unskilled and / or semi-skilled workers. A tool for turning the adjusting ring can be used particularly advantageously, wherein the adjusting ring has corresponding force-engaging means, preferably a wrench flat.

[0036] Features disclosed by the device shall also be considered disclosed by the process and be claimable, and vice versa.

[0037] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments of the invention and from the drawings.

[0038] Brief description of the drawings

[0039] Fig. 1 showed a sectional view of a flow control valve according to the prior art,

[0040] Fig. 2 shows a sectional view of a flow control valve in an embodiment according to the invention.

[0041] Embodiments of the invention

[0042] Identical elements or elements with the same function are provided with the same reference numbers in the figures.

[0043] Fig. 1 shows a sectional view of a flow control valve 1 according to the prior art in its installed state. A gas inlet 2 is fluidly connected to a valve chamber 23, which is formed between a valve plate 6 and an actuator assembly 8. The valve plate 6 rests against a valve seat element 4 and is biased towards the valve seat element 4 by means of a return element 7, here designed as a spring 17. Radially, an adjusting ring 22 surrounds the valve plate 6 in a radial direction R. The adjusting ring 22 sets the axial distance D in an axial direction A from the valve seat element 4 R. 413708

[0044] - 9 - to the drive group 8. A stop surface 19 is formed on the drive group 8, wherein the valve plate 6 is movable between the stop surface 19 and the valve seat element 4, so that the valve plate 6 can be lifted against the closing force F of the return element 7 by electromagnetic lifting by means of an electromagnet 18. The valve plate 6 can be lifted from the valve seat by a stroke H, limited by the stop surface 19 on one side and the valve seat element 4 on the other. In an open state of the flow control valve 1, gas flows from the gas inlet 2 into the valve chamber 23 and around the valve plate 6, which is lifted from the valve seat 4, through a flow opening 5 through the valve seat 4 to the gas outlet 3.

[0045] Fig. 2 shows a sectional view of a flow control valve 1 in an embodiment according to the invention in its installed state. Unlike the representation in Fig. 1, no adjusting ring 22 is arranged in the flow control valve 1. A plurality of balls 10 are arranged radially outward in the radial direction R, surrounding the valve plate 6. The balls 10 are advantageously made of corrosion-resistant steel. They bear against a frustoconical ball contact surface 11 of the valve seat element 4 and against a second ball contact surface 21 of the actuator assembly 8. The ball contact surface 11 is frustoconical in such a way that the distance between the ball contact surface 11 and the second ball contact surface 21 increases radially outward in the radial direction R. In the radial direction R, the position of the balls 10 radially outward is determined by a frustoconical adjusting ring surface 12 of an adjusting ring 13.The balls 10 are fixed radially inwards in the radial direction R by the frustoconical ball contact surface 11 of the valve seat element 4. The adjusting ring 13 is connected to the drive group 8 by means of a threaded connection 14, whereby the position of the adjusting ring 13 in the axial direction A relative to the drive group 8 is variable by means of the threaded connection 14.

[0046] The balls 10 define the axial distance D between the valve seat element 4 and the stop surface 19 of the drive assembly 8. Figure 2 shows that this axial distance D is reduced due to the frustoconical ball contact surface 11 when the balls 10 are positioned further outwards in the radial direction R. In this direction, the balls 10 are positioned by the adjusting ring surface 12 of the adjusting ring 13, so that the position of the adjusting ring 13 in the axial direction A directly determines the radial position of the balls 10. 413708

[0047] - 10 - and thus indirectly determines the axial distance D. The stroke H of the valve plate 6 can therefore be adjusted by moving the adjusting ring 13 relative to the drive assembly 8. For rotating the adjusting ring 13, a force engagement element 15 in the form of a wrench flat 16 is advantageously provided radially on the outside of the adjusting ring 13. To adjust the stroke H, a tool can be placed on the wrench flat 16 and used to rotate the adjusting ring 13.

[0048] When the electromagnet 18 is energized, the valve plate 6 is lifted off the valve seat element 4 against the effect of the closing force F, thus releasing a gas flow from the gas inlet 2 into the valve chamber 23, around the valve plate 6 and through the flow opening 5 to the gas outlet 3.

[0049] The flow opening 5 in the valve seat element 4 can be slot-shaped; preferably, several flow openings 5 ​​are formed in the valve seat element 4. The valve plate 6 can have recesses and / or channels which selectively influence the gas flow through the flow control valve 1 when open.

Claims

R. 413708 Claims 1. Flow control valve (1) for regulating a gas flow, in particular a flow of gaseous fuel, from a gas inlet (2) to a gas outlet (3), preferably for use in internal combustion engines, in particular large engines, comprising a valve seat element (4) with at least one flow opening (5), a valve plate (6) reversibly closing the flow opening (5), which is adjustable by means of an actuation assembly (8) between a closed position of the flow control valve (1), in which a gas flow through the flow control valve (1) is blocked, and in which the valve plate (6) rests against the valve seat element (4), and a maximum opening position of the flow control valve (1), in which a gas flow from the gas inlet (2) to the gas outlet (3) is maximal, and in which the valve plate (6) rests against a stop surface (19) of the actuation assembly (8),wherein a stroke (H) of the valve plate (6) between the closed position and the maximum open position is defined by an axial distance (D) between the valve seat element (4) and the stop surface (19) of the drive group (8) in an axial direction (A), characterized in that a plurality of balls (10) are arranged radially circumferentially surrounding the valve plate (6), wherein the balls (10) are arranged in axial direction (A) in contact on both sides between a frustoconical ball contact surface (11) of the valve seat element (4) and that of a second ball contact surface (21), preferably the stop surface (19), of the drive group (8), wherein the frustoconical ball contact surface (11) is chamfered in the radial direction (R) so that the distance between the frustoconical ball contact surface (11) and the drive group (8) increases radially outwards,wherein the balls (10) bear radially outwards against a frustoconical adjusting ring surface (12) of an adjusting ring (13), which is axially oriented (A) relative to the contact, R. 413708 - 12 - drive group (8) is designed to be displaceable, wherein the adjusting ring (13) determines a radial position of the balls (10) on the frustoconical ball contact surface (11) of the valve seat element (4) depending on an axial position of the adjusting ring (13), so that the axial distance (D) between the valve seat element (4) and the stop surface (19) of the drive group (8) is adjustable by axially displacing the adjusting ring (13).

2. Flow control valve (1) according to claim 1 , characterized in that the adjusting ring (13) is connected to the drive group (8) by means of a threaded connection (14) extending along the axial direction (A), so that the adjusting ring (13) can be displaced in the axial direction (A) relative to the drive group (8) by rotating the adjusting ring (13) relative to the drive group (8) by means of the threaded connection (14).

3. Flow control valve (1) according to claim 2, characterized in that the adjusting ring (13) has a force engagement means (15), preferably an engagement geometry for a tool, more preferably a wrench surface (16) for interaction with a wrench, by means of which the adjusting ring (13) can be rotated relative to the drive group (8).

4. Flow control valve (1) according to one of claims 1 to 3, characterized in that the balls (10) are made of steel, preferably of corrosion-resistant steel.

5. Flow control valve (1) according to one of claims 1 to 4, characterized in that in the maximum opening position of the flow control valve (1) an opening cross-sectional area for a gas flow from the gas inlet (2) to the gas outlet (3) of 10 to 400 mm² 2 preferably from 20 to 200 mm 2 , especially preferably from 40 to 80 mm 2 , is released. R. 413708 - 13 - 6. Flow control valve (1) according to one of claims 1 to 5, characterized in that the flow control valve (1) comprises a return means (7), preferably a spring (17), particularly preferably a helical compression spring, for applying a closing force (F) to the valve plate (6) directed towards the valve seat element (4).

7. Flow control valve (1) according to claim 6, characterized in that the drive group (8) comprises an electromagnet (18) for electromagnetically lifting the valve plate (6) from the valve seat element (4) against the closing force (F) of the return means (7), wherein the valve plate (6) is preferably made of a ferromagnetic material.

8. Method for adjusting the stroke of a flow control valve (1) for regulating a gas flow, in particular a flow of gaseous fuel, from a gas inlet (2) to a gas outlet (3), preferably for use in internal combustion engines, in particular large engines, comprising a valve seat element (4) with at least one flow opening (5), a valve plate (6) reversibly closing the flow opening (5), which is adjusted by means of a drive unit (8) between a closed position of the flow control valve (1), in which a gas flow through the flow control valve (1) is blocked, and in which the valve plate (6) rests against the valve seat element (4), and a maximum opening position of the flow control valve (1), in which a gas flow from the gas inlet (2) to the gas outlet (3) is maximal, and in which the valve plate (6) rests against a stop surface (19) of the drive unit (8),wherein a stroke (H) of the valve plate (6) between the closed position and the maximum opening position is defined by an axial distance (D) between the valve seat element (4) and the stop surface (19) of the drive group (8) in an axial direction (A), characterized in that R. 413708 - 14 - that by displacing an adjusting ring (13) in the axial direction (A) relative to the drive group (8) the axial distance (D) between the valve seat element (4) and the stop surface (19) of the drive group (8) is adjusted, wherein a plurality of balls (10) are arranged radially circumferentially surrounding the valve plate (6), wherein the balls (10) are arranged in axial direction (A) in contact on both sides between a frustoconical ball contact surface (11) of the valve seat element (4) and a second ball contact surface (21), preferably the stop surface (19), of the drive group (8), wherein the ball contact surface (11) is chamfered in the radial direction (R) so that the distance between the frustoconical ball contact surface (11) and the drive group (8) increases radially outwards, wherein the balls (10) are radially outside on a frustoconical adjusting ring surface (12) of the adjusting ring (13) concerns,whereby a radial position of the balls (10) on the frustoconical ball contact surface (11) of the valve seat element (4) is determined as a function of an axial position of the adjusting ring (13).

9. Method for adjusting the stroke of a flow control valve (1) according to claim 8, characterized in that the adjusting ring (13) is displaced in the axial direction (A) relative to the drive group (8) by rotating the adjusting ring (13) relative to the drive group (8) by means of a threaded connection (14), wherein the adjusting ring (13) is connected to the drive group (8) by means of the threaded connection (14) extending along the axial direction (A).

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