A gas injector

Abstract

The application relates to the technical field of automobile power devices, and particularly discloses a gas injector, wherein the sealing pipe is fixedly connected between the first protruding part and the second protruding part to form a first cavity filled with hydraulic oil; the first piston and the second piston are in sliding fit with the inner wall of the sleeve, the first piston and the second piston are arranged at intervals, and the first piston and the second piston form a second cavity together with the inner wall of the sleeve; the through hole is connected between the inner cavity of the sleeve and the first cavity; the first elastic member is sleeved on the sleeve; the second elastic member is connected between the second piston and the second protruding part; the piezoelectric actuator can drive the first piston to move in the first direction; and the second piston can drive the needle valve to move to open the gas outlet channel. The piezoelectric actuator generates output displacement, the hydraulic mechanism adaptively transmits the mechanical displacement, different ratios of the first piston and the second piston can be set, the displacement is further controlled, and the opening degree of the gas injector is reasonably controlled, so that the different gas injection amount requirements within a certain range can be met.

Description

Technical Field

[0001] This invention relates to the field of automotive power unit technology, and more particularly to a gas injector. Background Technology

[0002] Gas powertrains are one of the important ways to achieve low-carbon and zero-carbon transformation. This has led to the increasing use of clean gaseous fuels such as natural gas or hydrogen in the automotive industry. Gas injectors have been widely adopted. Gas injectors, also known as gas fuel injectors, are one of the core components of gas fuel systems. They can inject fuel into the engine in a timely and quantitative manner, and their jetting performance has a very important impact on engine performance.

[0003] Gas injectors are designed to handle the amount of gas injected based on the engine's power requirements. Existing piezoelectrically driven gas injectors require the output displacement of the piezoelectric actuator to control the injector's opening size. However, due to structural limitations, they cannot reasonably control the injector's opening size to meet different gas injection requirements within a certain range during actual injection, thus failing to meet the engine's gas injection needs and affecting engine performance. Summary of the Invention

[0004] The purpose of this invention is to provide a gas injector that can reasonably control the opening size of the gas injector to adapt to different gas flow requirements within a certain range.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a gas ejector, comprising:

[0007] The housing is provided with a receiving cavity and an air intake channel;

[0008] A hydraulic mechanism is disposed within the accommodating cavity. The hydraulic mechanism includes a first piston, a second piston, a sealing tube, a sleeve, a first elastic element, and a second elastic element. The first piston has a first protrusion, and the sleeve has a second protrusion. The sealing tube is made of elastic material and is fixedly connected between the first protrusion and the second protrusion to form a first cavity. The first cavity is filled with hydraulic oil. The outer diameter of the first piston is larger than the outer diameter of the second piston. Both the first piston and the second piston slide against the inner wall of the sleeve and are spaced apart along a first direction to form a second cavity with the inner wall of the sleeve. The sleeve has several through holes that connect the inner cavity of the sleeve to the first cavity. The first elastic element is sleeved on the sleeve, with one end spaced apart from the first protrusion and the other end abutting against the second protrusion. The second elastic element is connected between the second piston and the second protrusion.

[0009] A piezoelectric actuator is configured to drive the first piston to move along the first direction;

[0010] A needle valve assembly includes a valve body and a needle valve. The valve body has an air outlet channel that communicates with the air inlet channel. The needle valve is disposed within the air outlet channel and is capable of opening or closing the air outlet channel. A second piston can apply force to the needle valve to cause the needle valve to move along the first direction and open the air outlet channel.

[0011] As a preferred embodiment of the aforementioned gas injector, a first protrusion is provided on the inner wall of the sleeve, and the first piston can abut against the first protrusion along the first direction.

[0012] As a preferred embodiment of the above-mentioned gas injector, a second protrusion is provided on the inner wall of the accommodating cavity, and the sealing tube is configured to always have the tendency to drive the first protrusion to abut against the second protrusion in a second direction, the first direction being opposite to the second direction.

[0013] As a preferred embodiment of the gas injector, the gas injector further includes a gasket disposed between the second boss and the first protrusion.

[0014] As a preferred embodiment of the above-mentioned gas injector, the first piston is further provided with a third protrusion, and the output end of the piezoelectric actuator is provided with a groove, and the third protrusion is inserted into the groove.

[0015] As a preferred embodiment of the aforementioned gas injector, the needle valve assembly further includes a third elastic element configured to drive the needle valve to always tend to move toward a position that closes the gas outlet passage.

[0016] As a preferred technical solution of the above-mentioned gas injector, the gas injector further includes a fixing block, the fixing block is provided with an air passage and a guide channel extending along the first direction, the needle valve passes through the guide channel, and the air passage connects the air inlet channel and the air outlet channel.

[0017] As a preferred embodiment of the above-mentioned gas injector, the second piston is provided with a fourth protrusion, and the second elastic member is connected between the fourth protrusion and the second protrusion. The fourth protrusion can abut against the needle valve along the first direction.

[0018] As a preferred embodiment of the above-mentioned gas injector, the gas injector further includes a connecting sleeve, which securely connects the valve body and the fixing block to the housing.

[0019] As a preferred embodiment of the aforementioned gas injector, the first elastic element is a compression spring.

[0020] The beneficial effects of this invention are as follows:

[0021] This invention provides a gas ejector, comprising: a housing, a hydraulic mechanism, a piezoelectric actuator, and a needle valve assembly. The housing has a receiving cavity and an air inlet channel. The hydraulic mechanism is disposed within the receiving cavity and includes a first piston, a second piston, a sealing tube, a sleeve, a first elastic element, and a second elastic element. The first piston has a first protrusion, and the sleeve has a second protrusion. The sealing tube is made of an elastic material and is fixedly connected between the first and second protrusions to form a first cavity. The first cavity is filled with hydraulic oil. The outer diameter of the first piston is larger than the outer diameter of the second piston. Both the first and second pistons slide against the inner wall of the sleeve. The sleeve is spaced apart along the first direction and surrounds the inner wall of the sleeve to form a second cavity. The sleeve has several through holes that connect the inner cavity of the sleeve to the first cavity. A first elastic element is sleeved on the sleeve, with one end of the first elastic element spaced apart from the first protrusion and the other end abutting against the second protrusion. A second elastic element is connected between the second piston and the second protrusion. The piezoelectric actuator is configured to drive the first piston to move along the first direction. The needle valve assembly includes a valve body and a needle valve. The valve body has an air outlet channel that connects to the air inlet channel. The needle valve is located in the air outlet channel and can open or close the air outlet channel. The second piston can apply force to the needle valve to make the needle valve move along the first direction and open the air outlet channel. With this setup, during actual injection, the piezoelectric actuator will input different electrical signals based on different jet volume requirements, thereby generating different mechanical output displacements to drive the hydraulic mechanism to effectively transmit mechanical displacements adaptively. At the same time, according to the jet volume requirements, different ratios of the first and second pistons can be set to further control the displacement, thereby reasonably controlling the opening of the gas injector to adapt to different jet volume requirements within a certain range. Attached Figure Description

[0022] Figure 1 A schematic diagram of the structure of the gas injector provided by the present invention;

[0023] Figure 2 A schematic diagram of the hydraulic mechanism provided by the present invention.

[0024] in:

[0025] 1. Housing; 101. Receiving cavity; 102. Air intake passage;

[0026] 2. First piston; 201. First protrusion; 202. Third protrusion;

[0027] 3. Second piston; 301. Fourth protrusion;

[0028] 4. Sealing tube;

[0029] 5. Sleeve; 501. Second protrusion; 502. Through hole;

[0030] 6. First elastic element; 7. Second elastic element; 8. First cavity; 9. Second cavity; 10. Piezoelectric actuator; 11. Valve body; 12. Needle valve; 13. Air outlet channel; 14. Gasket; 15. Third elastic element; 16. Fixing block; 17. Air passage; 18. Connecting sleeve; 19. Oil passage. Detailed Implementation

[0031] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0033] Unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and connections within two components or interactions between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0034] Unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0036] like Figures 1 to 2 As shown, this embodiment provides a gas injector, which includes: a housing 1, a hydraulic mechanism, a piezoelectric actuator 10, and a needle valve assembly. The housing 1 has a receiving cavity 101 and an air inlet channel 102. The hydraulic mechanism is disposed in the receiving cavity 101 and includes a first piston 2, a second piston 3, a sealing tube 4, a sleeve 5, a first elastic element 6, and a second elastic element 7. The first piston 2 has a first protrusion 201, and the sleeve 5 has a second protrusion 501. The sealing tube 4 is made of an elastic material and is fixedly connected between the first protrusion 201 and the second protrusion 501 to form a first cavity 8. The first cavity 8 is filled with hydraulic oil. The outer diameter of the first piston 2 is larger than the outer diameter of the second piston 3. Both the first piston 2 and the second piston 3 slide against the inner wall of the sleeve 5, and the first piston 2 and the second piston 3 slide along the first... The sleeve 5 is arranged at directional intervals to form a second cavity 9 with the inner wall of the sleeve 5. The sleeve 5 is provided with several through holes 502, which connect the inner cavity of the sleeve 5 and the first cavity 8. The first elastic member 6 is sleeved on the sleeve 5, and one end of the first elastic member 6 is spaced apart from the first protrusion 201, and the other end abuts against the second protrusion 501. The second elastic member 7 is connected between the second piston 3 and the second protrusion 501. The piezoelectric actuator 10 is configured to drive the first piston 2 to move in the first direction. The needle valve assembly includes a valve body 11 and a needle valve 12. The valve body 11 is provided with an air outlet channel 13, which connects to the air inlet channel 102. The needle valve 12 is disposed in the air outlet channel 13 and can open or close the air outlet channel 13. The second piston 3 can apply force to the needle valve 12 to make the needle valve 12 move in the first direction and open the air outlet channel 13. With this configuration, during actual injection, the piezoelectric actuator 10 will input different electrical signals based on different jet volume requirements, thereby generating different mechanical output displacements to drive the hydraulic mechanism to effectively and adaptively transmit mechanical displacements. Furthermore, by setting different ratios of the first piston 2 and the second piston 3 according to the jet volume requirements, displacement control can be further achieved, thus enabling reasonable control of the gas injector opening to adapt to different jet volume requirements within a certain range. Specifically, both the first elastic element 6 and the second elastic element 7 are compression springs.

[0037] When the gas injector is used at a low flow rate, the output displacement generated by the signal input to the piezoelectric actuator 10 is small. At this time, the pressure of the hydraulic oil in the first protrusion 201, the first chamber 8, and the second chamber 9 is slightly changed, which pushes the second piston 3 to drive the second elastic element 7 to move in the first direction, thereby pushing the needle valve 12 to partially open the needle valve 12 to supply a small flow rate of gaseous fuel.

[0038] When the gas injector is used at high flow rates, the signal input to the piezoelectric actuator 10 generates a large output displacement. After the first protrusion 201 compresses the sealing tube 4, it continues to move along the first direction, further compressing the first elastic element 6. Due to the incompressibility of liquids, the pressure of the hydraulic oil in the first chamber 8 and the second chamber 9 increases rapidly, pushing the second piston 3 to move quickly, which in turn drives the second elastic element 7 to move along the first direction. This achieves a gradual opening of the needle valve 12, ultimately resulting in the complete opening of the needle valve 12 to supply a large flow rate of gaseous fuel. The above-mentioned gas injector further incorporates a hydraulic mechanism based on the existing structure, making it suitable for low-pressure or medium-high-pressure gas injection, with good versatility. Specifically, the distance between the first elastic element 6 and the first protrusion 201 is related to the opening degree of the needle valve 12 when the gas injector is used at high flow rates; preferably, the distance is less than 0.5 cm.

[0039] It should be noted that the sealing tube 4 is in a compressed state after the gas injector is assembled, which keeps the hydraulic oil in the first chamber 8 under a certain pressure. The pressure of the hydraulic oil is related to the elastic force of the sealing tube 4. The second elastic element 7 is in a slightly stretched state after the gas injector is assembled. When the first protrusion 201 moves in the first direction, the hydraulic pressure in the first chamber 8 changes, which in turn pushes the second piston 3 to drive the second elastic element 7 to move in the first direction, and the second elastic element 7 is further stretched. When the piezoelectric actuator 10 returns to its original position, the first piston 2 quickly returns to its original position, causing the hydraulic pressure in the second chamber 9 to drop. The second piston 3 and the second elastic element 7 return to their initial state, and the hydraulic oil in the first chamber 8 enters the second chamber 9 through the through hole 502, so that the hydraulic pressure returns to its initial pressure.

[0040] In this embodiment, the ratio of the outer diameter of the first piston 2 to the outer diameter of the second piston 3 is between 1 and 2. For example, the ratio of the outer diameter of the first piston 2 to the outer diameter of the second piston 3 can specifically be 1, 1.2, 1.4, 1.6, 1.8 or 2.

[0041] Specifically, the piezoelectric actuator is a piezoelectric multilayer actuator and is disposed within the accommodating cavity 101.

[0042] Optionally, in order to further ensure that the first piston 2 and the second piston 3 can slide freely on the inner wall of the sleeve 5, a small micro-ring is provided between the first piston 2 and the inner wall of the sleeve 5, and between the second piston 3 and the inner wall of the sleeve 5. The width of the micro-ring is no more than 5 micrometers. The hydraulic oil in the first cavity 8 enters the micro-ring between the first piston 2 and the second piston 3 and the inner wall of the sleeve 5 through the through hole 502, and finally enters the second cavity 9.

[0043] Optionally, in order to ensure that the sliding direction of the first piston 2 and the second piston 3 is stable and does not deviate, a first boss is provided on the inner wall of the sleeve 5, and the first piston 2 can abut against the first boss in the first direction.

[0044] Optionally, in order to limit the first protrusion 201 and ensure that the output displacement of the piezoelectric actuator 10 is stable and does not deviate, a second protrusion is provided on the inner wall of the accommodating cavity 101. The sealing tube 4 is configured to always have the tendency to drive the first protrusion 201 to abut against the second protrusion along a second direction, which is opposite to the second direction. It should be noted that the first direction and the second direction are respectively as shown in the figure. Figure 1 The two arrows in the image indicate the direction.

[0045] Furthermore, the gas injector also includes a gasket 14, which is disposed between the second boss and the first protrusion 201. With this arrangement, the gasket 14 can provide a good seal, preventing gas from flowing into the chamber of the piezoelectric actuator 10 in the second direction. At the same time, it can further reduce the impact force of the output end of the piezoelectric actuator 10 on the upper end surface of the first piston 2.

[0046] Specifically, the following scheme is provided as an example in this embodiment: the output end face of the piezoelectric actuator 10 is kept in close contact with the upper end face of the first piston 2, and their relative relationship is adjusted by the thickness of the shim 14. The hardness of the shim 14 is slightly less than that of the first piston 2. Furthermore, the shim 14 can be made of a metal material with lower hardness or a non-metal material with higher hardness.

[0047] Optionally, in order to ensure that the direction of the force transmitted from the output end of the piezoelectric actuator 10 to the first piston 2 is stable and controllable, the first piston 2 is also provided with a third protrusion 202, the output end of the piezoelectric actuator 10 is provided with a groove, and the third protrusion 202 is inserted into the groove.

[0048] Optionally, the needle valve assembly further includes a third elastic element 15, which is configured to drive the needle valve 12 to always tend to move towards the closed gas outlet passage 13. Further, the needle valve 12 has a first abutment surface, and the valve body 11 has a second abutment surface. With this configuration, before the second piston 3 abuts against the needle valve 12, under the pre-tightening force of the third elastic element 15, the first abutment surface of the needle valve 12 always abuts against the second abutment surface of the valve body 11, thereby achieving a seal. When the second piston 3 abuts against the needle valve 12, it acts on the head of the needle valve 12, thereby overcoming the pre-tightening force of the third elastic element 15, pushing the needle valve 12 to move in the first direction, ultimately causing the first abutment surface to separate from the second abutment surface, thus completing the gas ejection.

[0049] In this embodiment, a locking nut is threaded onto the needle valve 12, and a third elastic element 15 abuts against the locking nut and the valve body 11. Specifically, the third elastic element 15 is a compression spring.

[0050] It should be noted that the stiffness of the sealing tube 4 is comparable to that of the second elastic element 7, but both are less than the stiffness of the first elastic element 6.

[0051] Optionally, in order to ensure that the direction of the force exerted by the second piston 3 on the needle valve 12 is stable and controllable, so that the needle valve 12 does not deviate during the movement along the first direction, the gas injector also includes a fixing block 16. The fixing block 16 is provided with an air passage 17 and a guide channel extending along the first direction. The needle valve 12 passes through the guide channel, and the air passage 17 connects the air inlet channel 102 and the air outlet channel 13.

[0052] Optionally, the second piston 3 is provided with a fourth protrusion 301, and the second elastic member 7 is connected between the fourth protrusion 301 and the second protrusion 501. The fourth protrusion 301 can abut against the needle valve 12 in the first direction.

[0053] Optionally, the gas injector also includes a connecting sleeve 18, which securely connects the valve body 11 and the fixing block 16 to the housing 1.

[0054] Optionally, in order to facilitate timely replenishment of hydraulic oil, the first protrusion 201 is provided with an oil passage 19 that communicates with the first cavity 8.

[0055] As one alternative, the sealing tube 4 and the first elastic element 6 can be combined into a variable stiffness elastic tube, and the stiffness of the side closer to the first protrusion 201 is softer than the stiffness of the side farther from the first protrusion 201.

[0056] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A gas injector, characterized in that, include: The housing (1) is provided with a receiving cavity (101) and an air intake channel (102); A hydraulic mechanism is disposed within the accommodating cavity (101). The hydraulic mechanism includes a first piston (2), a second piston (3), a sealing tube (4), a sleeve (5), a first elastic element (6), and a second elastic element (7). The first piston (2) has a first protrusion (201), and the sleeve (5) has a second protrusion (501). The sealing tube (4) is made of elastic material and is fixedly connected between the first protrusion (201) and the second protrusion (501) to form a first cavity (8). The first cavity (8) is filled with hydraulic oil. The outer diameter of the first piston (2) is larger than the outer diameter of the second piston (3). Both the plug (2) and the second piston (3) are slidably engaged with the inner wall of the sleeve (5), and the first piston (2) and the second piston (3) are spaced apart along the first direction, forming a second cavity (9) with the inner wall of the sleeve (5). The sleeve (5) is provided with a plurality of through holes (502), and the through holes (502) connect the inner cavity of the sleeve (5) with the first cavity (8). The first elastic member (6) is sleeved on the sleeve (5), and one end of the first elastic member (6) is spaced apart from the first protrusion (201), and the other end abuts against the second protrusion (501). The second elastic member (7) is connected between the second piston (3) and the second protrusion (501). The piezoelectric actuator (10) is configured to drive the first piston (2) to move along the first direction; The needle valve assembly includes a valve body (11) and a needle valve (12). The valve body (11) is provided with an air outlet channel (13), which is connected to the air inlet channel (102). The needle valve (12) is disposed in the air outlet channel (13) and can open or close the air outlet channel (13). The second piston (3) can apply force to the needle valve (12) so that the needle valve (12) moves in the first direction to open the air outlet channel (13).

2. The gas injector according to claim 1, characterized in that, The inner wall of the sleeve (5) is provided with a first protrusion, and the first piston (2) can abut against the first protrusion along the first direction.

3. The gas injector according to claim 1, characterized in that, The inner wall of the accommodating cavity (101) is provided with a second protrusion, and the sealing tube (4) is configured to always have the tendency to drive the first protrusion (201) to abut against the second protrusion in a second direction, which is opposite to the second direction.

4. The gas injector according to claim 3, characterized in that, The gas injector also includes a gasket (14) disposed between the second boss and the first protrusion (201).

5. The gas injector according to any one of claims 1-4, characterized in that, The first piston (2) is also provided with a third protrusion (202), and the output end of the piezoelectric actuator (10) is provided with a groove, and the third protrusion (202) is inserted into the groove.

6. The gas injector according to any one of claims 1-4, characterized in that, The needle valve assembly also includes a third elastic element (15) configured to drive the needle valve (12) to always have a tendency to move toward the position of closing the air outlet passage (13).

7. The gas injector according to any one of claims 1-4, characterized in that, The gas injector also includes a fixing block (16), which has an air passage (17) and a guide channel extending along the first direction. The needle valve (12) passes through the guide channel, and the air passage (17) connects the air inlet channel (102) and the air outlet channel (13).

8. The gas injector according to claim 7, characterized in that, The second piston (3) has a fourth protrusion (301) and the second elastic member (7) is connected between the fourth protrusion (301) and the second protrusion (501). The fourth protrusion (301) can abut against the needle valve (12) along the first direction.

9. The gas injector according to claim 7, characterized in that, The gas injector also includes a connecting sleeve (18), which fixes the valve body (11) and the fixing block (16) to the housing (1).

10. The gas injector according to any one of claims 1-4, characterized in that, The first elastic element (6) is a compression spring.

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