Gas injector with damper

Abstract

The invention relates to a gas injector for blowing in gaseous fuel, comprising: a magnetic actuator (2) having an armature (20), an inner pole (21) and a coil (22); a closing element (3) having a valve needle (30) and an armature bolt (23), the valve needle (30) releasing and closing a gas path (14) on a sealing seat (11) arranged at a first end of the gas injector, the armature (20) being connected to the armature bolt (23) and the armature bolt (23) being operatively connected to the valve needle (30); a closed lubricant chamber (4), which is filled with a lubricant and in which the armature (20) and the armature bolt (23) are arranged, the lubricant providing a lubricating action in the lubricant chamber (4); a restoring element (10) which resets the closing element (3) into a closed starting position, in which the lubricant chamber (4) is filled with a gas and a liquid lubricant for damping during the movement of the closing element (3), and in which the volume ratio of the liquid to the gas is in the range of 70% / 30 to 95% / 5%.

Description

Technical Field

[0001] The present invention relates to a gas injector for blowing gaseous media (e.g., hydrogen, natural gas, methane, liquefied petroleum gas (LPG), ammonia, etc.) into the combustion chamber of an internal combustion engine, the gas injector having damping characteristics improved by means of a hydraulic damper. Background Technology

[0002] Various gas ejector configurations are known in the prior art. Due to the relatively high gas pressure, especially during shutdown, the shut-off element, particularly the valve needle, may violently impact the sealing seat. To unnecessarily shorten the service life of the gas ejector, a damping device should be incorporated. To unnecessarily increase manufacturing and maintenance costs, a simpler solution should be preferred. Summary of the Invention

[0003] In contrast, the gas injector according to the invention for blowing in gaseous fuel, having the features of claim 1, has the following advantages: a simple and reliable damping shut-off element can be achieved during the shut-off process of the gas injector. Here, damping is ensured throughout the entire service life of the gas injector. This damping is also particularly robust and cost-effective, thus suitable for mass production of gas injectors. Furthermore, the damping according to the invention requires very little installation space. Moreover, this damping prevents vibration excitation of other components of the gas injector during shut-off, thereby significantly reducing the load on other components during operation.

[0004] According to the invention, this is achieved by the following: the gas injector has a magnetic actuator having an armature, an inner pole, and a coil. Furthermore, the gas injector includes a shut-off element with a valve needle, wherein the shut-off element releases and closes the gas path at a sealing seat at a first end of the gas injector. This, for example, allows gas to be blown into the combustion chamber or terminates the blowing. The shut-off element also includes an armature bolt connected to the armature and operatively connected to the valve needle. The valve needle and armature bolt are preferably rod-shaped members, loosely abutting against each other's opposing end faces and capable of moving independently of each other. The gas injector also includes a lubricant chamber sealed by a lubricant housing, the lubricant chamber being filled with lubricant. The armature and armature bolt are arranged in the lubricant chamber, wherein the lubricant provides lubrication to the components within the lubricant chamber. A reset element resets the shut-off element to its initial closed position. The lubricant chamber is preferably partially enclosed by a flexible sealing element, particularly a bellows, which is arranged on the shut-off element. A flexible sealing element here seals the lubricant chamber relative to the gas path passing by. Furthermore, the gas ejector includes a damping device arranged within the lubricant chamber for the closing process of the damping shut-off element. The damping device includes gas arranged within the lubricant chamber, particularly for volume compensation. Therefore, a liquid for damping (especially during the closing process) is provided within the lubricant chamber.

[0005] The lubricant chamber is enclosed by a lubricant housing, which preferably has multiple components. Here, the volume ratio of liquid (i.e., liquid lubricant) to gas in the lubricant chamber is in the range of 70% / 30% to 95% / 5%. Particularly preferably, the liquid to gas volume ratio is in the range of 80% / 20% to 90% / 10%. Even more preferably, the liquid to gas volume ratio in the lubricant chamber is approximately 85% to 15%. This ensures that volume compensation can also be achieved through the gas present in the lubricant chamber.

[0006] Another advantage of partially gas-filled lubricant chambers is that temperature changes can cause the liquid lubricant to expand in volume, which can be compensated for by the gas in the lubricant chamber. When the liquid lubricant expands due to temperature, the gas in the lubricant chamber is slightly compressed, thus compensating for the volume change of the liquid lubricant caused by temperature.

[0007] By using liquids and gases in the lubricant chamber, complex damping can be eliminated, for example, by setting additional metal bellows on the lubricant housing solely for damping.

[0008] Since the lubricant chamber is additionally filled with gas in addition to liquid lubricant, a damping device is integrated into the lubricant chamber. This damping device ensures damping of moving parts within the lubricant chamber, especially during closure. Furthermore, this damping device can compensate for length changes in components within the lubricant chamber or the housing components of the lubricant casing caused by temperature.

[0009] In particular, for example, the length change of the shut-off element caused by heat can be compensated. It is also possible that, for example, the volume change of the liquid lubricant caused by heat can be compensated by the additional compression of the gas in the lubricant chamber.

[0010] Here, the combined compensation and damping device according to the invention in the lubricant chamber is a very cost-effective, compact and very robust solution that is effective throughout the entire service life of the gas injector.

[0011] The dependent claims illustrate preferred modifications of the invention.

[0012] Preferably, the lubricant housing has multiple housing components that define the lubricant chamber. Here, exactly one of the housing components is a metal bellows. This metal bellows is connected to the shut-off element. The metal bellows ensures the axial mobility of the shut-off element during both opening and closing processes. A very robust gas injector is achieved through the metal bellows.

[0013] Particularly preferably, all housing components of the lubricant housing are made of metal. Steel is preferred as the metal.

[0014] For a particularly robust configuration, welded joints are provided to connect the metal housing components of the lubricant housing. These welded joints provide a particularly good connection between the housing components of the lubricant chamber and achieve a reliable seal relative to the gas to be blown in. Hydrogen may diffuse through the metal housing components only when hydrogen is used as the gas.

[0015] According to another preferred embodiment of the invention, at least one housing member of the lubricant housing is made of an elastomeric material. The elastomeric material thus forms part of the outer shell of the lubricant chamber. Here, the elastomeric material in the lubricant housing allows gases, especially hydrogen, to diffuse more easily into and out of the lubricant chamber. In particular, hydrogen can diffuse more easily from the lubricant chamber into the gas path of the gas injector.

[0016] Particularly preferably, the housing member of the lubricant housing, made of an elastomer, is a closure plug or a flat seal. A closure plug can, for example, be simply disposed in an opening in the metal lubricant housing member. An elastomer flat seal is preferably constructed as annular and arranged between two flat regions of the metal housing member of the lubricant housing.

[0017] More preferably, at least one welded joint between the two metal housing members used to connect the lubricant housing is interrupted circumferentially at at least one location. Here, an elastomeric seal, such as an O-ring, is arranged between the metal housing members to be connected for sealing. The interrupted welded joint and the elastomeric seal enable the diffusion process into and out of the lubricant chamber. This configuration of the gas injector is particularly preferred because the seal, made of elastomeric material, is arranged between the two metal housing members of the lubricant housing and is substantially covered by the welded joint. Direct contact between the elastomeric seal and the gas to be injected exists only in the region of the interrupted welded joint.

[0018] If the elastomeric housing component is, for example, a closed plug, then the opening in the lubricant housing can also be used to fill the lubricant chamber with liquid lubricant and gas.

[0019] Preferably, the gas pressure in the lubricant chamber is between atmospheric pressure and 4 x 10⁻⁶. 5 Between Pa pressures.

[0020] The liquid lubricant is preferably a mineral oil, synthetic oil, silicone oil, or perfluoropolyether, especially Fonbilin, or any mixture of the above liquids. More preferably, the liquid lubricant has an anti-foaming additive that prevents foaming.

[0021] The gas located in the lubricant chamber is preferably ambient air, nitrogen, or an inert gas such as helium, neon, or argon.

[0022] The gas injector in the internal combustion engine preferably has a vertical or substantially vertical mounting position. Preferably, the mounting position of the gas injector is within ±20° relative to the vertical direction, and more particularly within ±10° relative to the vertical direction.

[0023] The selection of liquid lubricants depends in particular on the type of lubricant housing, especially its material, the specific solubility of the selected gas in the lubricant chamber, the cavitation resistance and / or shear resistance of the liquid lubricant, lubrication capacity, viscosity, viscosity index and / or coefficient of thermal expansion.

[0024] The choice of gas is preferably coordinated with the implementation type of the lubricant housing and the implementation type of the selected liquid lubricant.

[0025] More preferably, the gas injector is configured to blow gas into the combustion chamber of the internal combustion engine. Attached Figure Description

[0026] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings: Figure 1A schematic cross-sectional view of a gas injector according to a first embodiment of the present invention, and Figure 2 Figure 1 A schematic, enlarged partial cross-sectional view of the gas injector. Detailed Implementation

[0027] Below, we will refer to Figure 1 and Figure 2 A gas injector 1 according to a first preferred embodiment of the present invention is described in detail.

[0028] like Figure 1 As shown, the gas injector 1 for blowing gaseous fuel into the combustion chamber 12 includes a magnetic actuator 2. The magnetic actuator 2 is configured to move the outwardly opening closing element 3 from a closed state to an open state. Figure 1 and Figure 2 This shows the gas injector 1 in the off state.

[0029] The magnetic actuator 2 includes an armature 20, an inner pole 21, and a coil 22.

[0030] The closing element 3 includes a valve needle 30 and an armature bolt 23. The armature 20 is fixed to the armature bolt 23.

[0031] The valve needle 30 and the armature bolt 23 are loosely in contact with each other on their adjacent end faces, allowing the armature bolt 23 and the valve needle 30 to move independently of each other. The valve needle 30 includes a disc-shaped sealing element 300 that closes the gas injector 1 at the sealing seat 11.

[0032] Furthermore, the gas injector 1 includes a main body 7 having a gas inlet 70 through which gaseous fuel is supplied to the gas injector. The gas inlet 70 is introduced into the main body in the axial direction XX of the gas injector. The main body 7 is connected to a valve housing 8, in which a magnetic actuator 2 is arranged. The valve housing 8 also serves as a magnetic circuit element for the magnetic actuator 2.

[0033] In the axial direction XX, the housing sleeve 19 is attached to the valve housing 8. The sealing seat 11 is constructed on the end of the housing sleeve 19 that faces the combustion chamber.

[0034] Reference numeral 13 in the attached figure indicates an electrical attachment, which in... Figure 1 The image is only schematically shown and extends through the body to the magnetic actuator 2. The electrical attachment 13 is used to power the magnetic actuator.

[0035] To reset the opened closing element, the gas injector 1 also includes a reset element 10. In this embodiment, the reset element 10 is a cylindrical spring that resets the closing element 3 to its original position after the opening process. Figure 1 In the closed position shown.

[0036] The gas flow extending through gas injector 1 Figure 1 The diagram schematically shows a gas path 14. The gas path 14 extends from the gas inlet 70 inside the housing member of the gas injector to the sealing seat 11. The gas path 14 extends outside the magnetic actuator 2.

[0037] The gas injector 1 also includes a lubricant chamber 4. The lubricant chamber 4 is an enclosed space that is partially filled with liquid lubricant 47, such as oil, and gas 46 of the damping device 6.

[0038] like Figure 1 As shown, the lubricant housing 400 of the lubricant chamber 4 is defined by a first flexible sealing element 40 in the form of a bellows, a first sleeve 41, an inner pole 21, and a second sleeve 42. The second sleeve 42 is constructed in a can shape.

[0039] The flexible sealing element 40 is fixedly connected to the valve needle 30, and is preferably a metal bellows. The flexible sealing element 40 here ensures the axial mobility of the valve needle 30.

[0040] In the components of the lubricant chamber, or in the components arranged in the lubricant chamber, there is correspondingly provided... Figure 1 The through opening, not shown, allows the fluid distribution in the lubricant chamber to extend from the end on the combustion chamber side to the end in the direction of the gas inlet 70.

[0041] like Figure 2 As shown, the lubricant housing 400 has multiple metal housing components 401, 402, and 403, which are interconnected by welds 44. An opening is provided in the metal housing component 401, which is closed by a sealing plug 48 made of an elastomer. Because the sealing plug 48 is made of an elastomer material, the diffusion of hydrogen into and from the lubricant chamber 4 is significantly simplified. Although hydrogen can also diffuse through the metal components, the diffusion of hydrogen through the metal components is significantly less than the diffusion through the elastomer components.

[0042] The weld 44 between metal shell member 402 and metal shell member 403 has an interruption 44a. This is in Figure 2 The diagram is schematically shown. Two metal housing members 402 and 403 overlap in the axial direction XX, with an elastomeric O-ring 49 for sealing radially between the metal members 402 and 403. An interruption 44a in the weld 44 ensures improved strength of the welded joint. Due to this interruption, a seal can be achieved by the O-ring 49 between the two housing members 402 and 403.

[0043] It should be noted that, instead of the sealing plug 48 at the end of the lubricant chamber 4 away from the combustion chamber, a flat seal may also be provided, which is located between two overlapping flat areas of the housing component of the lubricant housing 400.

[0044] like Figure 2 As shown in detail, by arranging the gas injector 1 vertically or substantially vertically, gas can be concentrated in the area of ​​the lubricant chamber 4 away from the sealing seat 11 and where the sealing plug 48 is arranged.

[0045] The gas injector 1 according to the present invention functions as follows: When the gas injector is open, the armature 20 is attracted toward the inner pole 21, overcoming the armature gap 24. Since the armature 20 is fixedly connected to the armature bolt 23, the armature bolt also moves toward the sealing seat 11. In the closed state, because the armature bolt directly abuts against the valve needle 30 on the side pointing toward the combustion chamber, the valve needle 30 also moves in the axial direction XX and opens at the sealing seat 11. Therefore, the gas injector of the first embodiment is an outwardly opening gas injector.

[0046] Therefore, gas blowing begins.

[0047] During the opening and closing processes, the valve needle 30 is guided at two needle guides 31, 32 on the housing sleeve 19.

[0048] When the gas blowing ends, the energization of the magnetic actuator 2 is stopped, causing the shut-off element 3 to be brought back to its original position by the reset force of the reset element 10. Figure 1 In the closed position shown.

[0049] To prevent the valve disc from impacting the sealing seat 11 too hard, a damping device 6 is provided. The damping device 6 includes a gas 46, which is supplied to a liquid lubricant 47 disposed in a lubricant chamber 4. During the closing process, the lubricant 47 begins to move, and the movement of the closing element is damped by fluid resistance.

[0050] Therefore, no additional bellows is required at the end of the lubricant chamber 4 away from the sealing seat 11, thereby significantly reducing the cost of the gas injector 1. Thus, the gas injector 1 includes exactly one metal bellows 40, which is directly connected to the shut-off element 3, particularly the valve needle 30.

[0051] By only partially filling the lubricant chamber 4 with liquid lubricant 47, the thermally induced length changes of the gas injector components, especially the shut-off element, as well as the thermal expansion of the lubricant 47, can also be compensated.

[0052] The volume ratio of liquid to gas is preferably in the range of 70% / 30% to 95% / 5%.

[0053] Therefore, through this simplification of the gas injector, a very cost-effective and robust gas injector with the possibility of lubricating moving parts can be realized.

Claims

1. A gas injector for blowing in gaseous fuel, the gas injector comprising: A magnetic actuator (2) having an armature (20), an inner pole (21) and a coil (22); The shut-off element (3) has a valve needle (30) and an armature bolt (23), wherein the valve needle (30) releases and shuts off the gas path (14) at a sealing seat (11) located at the first end of the gas injector, wherein the armature (20) is connected to the armature bolt (23), and the armature bolt (23) is operatively connected to the valve needle (30); A closed lubricant chamber (4) is filled with lubricant, and the armature (20) and the armature bolt (23) are arranged in the lubricant chamber, wherein the lubricant provides lubrication in the lubricant chamber (4); The reset element (10) resets the shut-off element (3) to the shut-off initial state. The lubricant chamber (4) is filled with gaseous and liquid lubricant to dampen the movement of the closing element (3), and The volume ratio of the liquid to the gas is in the range of 70% / 30% to 95% / 5%.

2. The gas injector according to claim 1, wherein, The lubricant chamber (4) has a lubricant housing (400) which includes a plurality of housing components, wherein exactly one of the housing components is a metal bellows that is operatively connected to the shut-off element (3).

3. The gas injector according to claim 2, wherein, The lubricant housing (400) has multiple housing components made of metal, especially steel.

4. The gas injector according to claim 3, wherein, The metal shell components are connected to each other by welded joints (44).

5. The gas injector according to claim 4, wherein, At least one welded joint has an interruption (44a), wherein the seal between the two housing components is achieved by means of a seal, in particular an O-ring (42).

6. The gas injector according to any one of the preceding claims, wherein, At least one housing component of the lubricant housing (400) is made of an elastomeric material.

7. The gas injector according to claim 6, wherein, The shell component made of elastomeric material is a closure plug (41) or a flat seal.

8. The gas injector according to any one of claims 1 to 5, wherein, All housing components of the lubricant housing (400) are made of metal.

9. The gas injector according to any one of the preceding claims, wherein, The pressure of the gas in the lubricant chamber (4) is between ambient pressure and 4 x 10⁻⁶. 5 Within the range of Pa.

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