A gas injector

Abstract

The present invention relates to the technical field of automobile power devices, and in particular to a gas injector. The gas injector includes a housing, a nozzle assembly, and a control valve assembly. The control valve assembly includes an electromagnet structure, an iron core, a valve stem, and a first elastic member. The valve stem is provided with a first connecting portion and a second connecting portion. The first connecting portion is closer to the iron core relative to the second connecting portion. The second connecting portion is in clearance with the hole wall of the intake passage, and the second connecting portion can be separated from the hole wall of the intake passage. The valve stem can be moved along the length direction of the intake passage by the first connecting portion and the second connecting portion. When a small injection amount is required, the gap between the second connecting portion and the intake passage can play a throttling role; when a large injection amount is required, the second connecting portion is separated from the intake passage, meeting different injection amount requirements and achieving the purpose of accurately controlling the gas injection amount.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile power devices, in particular to a gas injector. Background Art

[0002] Transportation is a major area of ​​carbon emissions. Promoting the automotive sector's transition from traditional energy sources to clean fuels such as low-carbon or zero-carbon gases is a key path for my country to achieve its dual carbon goals. Reducing carbon emissions from transportation by using clean, less carbon-intensive hydrogen is considered a key measure for the sustainable development of future road transportation. Gas fuel injectors, as key actuators for hydrogen injection, ensure the timely and quantitative delivery of fuel to the vehicle's power unit, and their performance directly impacts engine reliability and combustion efficiency.

[0003] In the existing technology, gas injectors generally use electromagnets to directly drive the armature assembly to move, separate the sealing surfaces, and use the gas pressure in the cavity to drive the needle valve to open and close. Since it is gas-driven, precise control of the gas injection amount cannot be achieved when the needle valve lift is small or the injection time is short.

[0004] Therefore, a gas injector is urgently needed to solve the above technical problems. Summary of the Invention

[0005] The object of the present invention is to provide a gas injector capable of accurately controlling the gas injection amount.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A gas injector comprising:

[0008] a housing, wherein the housing is provided with an air intake passage passing through the housing;

[0009] an air nozzle assembly connected to the housing, the air nozzle assembly being provided with a first passage communicating with the air intake passage;

[0010] 14. The control valve assembly of claim 13, wherein the control valve assembly includes an electromagnet structure, an iron core, a valve stem and a first elastic member, the electromagnet structure being arranged on the housing, the iron core being arranged on the hole wall of the intake passage, the iron core being provided with a second channel communicating with the intake passage, the valve stem being slidably arranged on the hole wall of the intake passage, the valve stem being provided with a third channel communicating with the second channel, the third channel being communicated with the first channel, the first elastic member being configured to drive the valve stem to always have a tendency to abut against the iron core, the electromagnet structure being capable of driving the valve stem to separate from the iron core, the valve stem being capable of abutting or separating from the air nozzle assembly to open or close the air nozzle assembly, the valve stem being provided with a first connecting portion and a second connecting portion, the first connecting portion being close to the iron core relative to the second connecting portion, the second connecting portion being gap-fitted with the hole wall of the intake passage, and the second connecting portion being capable of being separated from the hole wall of the intake passage.

[0011] As a preferred technical solution of the above-mentioned gas injector, the distance between the first connecting portion and the hole wall of the air inlet channel and the distance between the second connecting portion and the hole wall of the air inlet channel are both 0.01 mm to 0.015 mm.

[0012] As a preferred technical solution of the above-mentioned gas injector, a first limiting portion is provided on the hole wall of the air inlet channel, and the first connecting portion can abut against the first limiting portion.

[0013] As a preferred technical solution of the above-mentioned gas injector, the gas injector further includes a sealing member, which is arranged at an end of the valve stem away from the iron core, and the sealing member can abut against the hole wall of the air inlet channel.

[0014] As a preferred technical solution of the above-mentioned gas injector, the hole wall of the air inlet channel is provided with a second limiting portion, and the iron core can abut against the second limiting portion.

[0015] As a preferred technical solution of the above-mentioned gas injector, the gas injector further includes a first gasket, which is arranged between the second limiting portion and the iron core.

[0016] As a preferred technical solution of the above-mentioned gas injector, the gas nozzle assembly includes a shell, a needle valve and a second elastic member. The first channel is provided in the shell, and the needle valve is slidably provided on the hole wall of the first channel. The valve stem can be abutted against the needle valve and is used to open the first channel. The second elastic member is configured to drive the needle valve to always have a tendency to close the first channel.

[0017] As a preferred technical solution of the above-mentioned gas injector, the gas nozzle assembly also includes a first mounting seat, which is sleeved on the outer periphery of the needle valve, and the two ends of the second elastic member are respectively connected to the first mounting seat and the outer shell.

[0018] As a preferred technical solution of the above-mentioned gas injector, a third limiting portion is provided on the hole wall of the first channel, and the first mounting seat can abut against the third limiting portion.

[0019] As a preferred technical solution of the above-mentioned gas injector, the gas injector further includes a second gasket, which is arranged between the second elastic member and the housing.

[0020] Beneficial effects of the present invention:

[0021] The present invention provides a gas injector. The gas injector includes a housing, a gas nozzle assembly, and a control valve assembly. The housing is provided with an air inlet passage extending through the housing; the gas nozzle assembly is connected to the housing and is provided with a first passage communicating with the air inlet passage; the control valve assembly includes an electromagnet structure, an iron core, a valve stem, and a first elastic member. The electromagnet structure is provided in the housing; the iron core is provided in a hole wall of the air inlet passage and is provided with a second passage communicating with the air inlet passage; the valve stem is slidably provided in the hole wall of the air inlet passage and is provided with a third passage communicating with the second passage, and the third passage is communicated with the first passage. The first elastic member is configured to drive the valve stem to always have a tendency to abut against the iron core; the electromagnet structure is capable of driving the valve stem to separate from the iron core, so that the valve stem can abut or separate from the gas nozzle assembly to open or close the gas nozzle assembly; the valve stem is provided with a first connecting portion and a second connecting portion. The first connecting portion is provided at an end proximal to the iron core and is movable along the length of the air inlet passage; the second connecting portion is provided at an end distal to the iron core and is movable along the length of the air inlet passage and is separable from the hole wall of the air inlet passage. The first connecting part and the second connecting part can enable the valve stem to move along the length direction of the intake channel to prevent the valve stem from being offset. When a small injection amount of gas is required, the gap between the second connecting part and the intake channel can play a throttling role to produce a small injection amount of gas; when a large injection amount of gas is required, the second connecting part is separated from the intake channel to produce a large injection amount of gas, thereby meeting different injection amount requirements and achieving the purpose of accurately controlling the gas injection amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without any creative work.

[0023] Figure 1 A schematic structural diagram of a gas injector provided in an embodiment of the present invention;

[0024] Figure 2 for Figure 1 A partial enlarged view of middle A;

[0025] Figure 3 for Figure 1 A partial enlarged view of B in the middle;

[0026] Figure 4 for Figure 1 A partial enlarged view of C in the middle.

[0027] In the picture:

[0028] 1. Shell; 11. First limiting part; 12. Second limiting part; 2. Air nozzle assembly; 21. Shell; 211. Third limiting part; 22. Needle valve; 23. Second elastic member; 24. First mounting seat; 25. Locking nut; 3. Control valve assembly; 31. Electromagnet structure; 32. Iron core; 33. Valve stem; 331. First connecting part; 332. Second connecting part; 34. First elastic member; 4. Sealing member; 5. First gasket; 6. Second gasket; 7. First locking cap; 8. Second locking cap; 9. Second mounting seat; 10. Inlet pipe. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0030] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0031] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0032] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0033] like Figure 1 As shown, the present invention provides a gas injector, which includes a housing 1 , a gas nozzle assembly 2 and a control valve assembly 3 .

[0034] Specifically, if Figure 1 and Figure 3As shown, the housing 1 is provided with an air intake passage running through the housing 1; the air nozzle assembly 2 is connected to the housing 1, and the air nozzle assembly 2 is provided with a first passage communicating with the air intake passage; the control valve assembly 3 includes an electromagnet structure 31, an iron core 32, a valve stem 33 and a first elastic member 34, the electromagnet structure 31 is provided on the housing 1, the iron core 32 is provided on the hole wall of the air intake passage, the iron core 32 is provided with a second passage communicating with the air intake passage, the valve stem 33 is slidably provided on the hole wall of the air intake passage, the valve stem 33 is provided with a third passage communicating with the second passage, the third passage is communicated with the first passage, and the first elastic member 34 is configured to drive the valve stem 33 to start It eventually tends to counteract the iron core 32. The electromagnet structure 31 can drive the valve stem 33 to separate from the iron core 32. The valve stem 33 can counteract or separate from the air nozzle assembly 2 to open or close the air nozzle assembly 2. The valve stem 33 is provided with a first connection part 331 and a second connection part 332. The first connection part 331 is provided at one end close to the iron core 32. The first connection part 331 can move along the length direction of the air intake channel. The second connection part 332 is provided at one end away from the iron core 32. The second connection part 332 can move along the length direction of the air intake channel, and the second connection part 332 can be separated from the hole wall of the air intake channel. The first connecting part 331 and the second connecting part 332 can enable the valve stem 33 to move along the length direction of the intake channel, preventing the valve stem 33 from being offset and avoiding jamming; when a small injection amount of gas is required, the gap between the second connecting part 332 and the intake channel can play a throttling role, generating a small injection amount of gas; when a large injection amount of gas is required, the second connecting part 332 is separated from the intake channel, generating a large injection amount of gas, thereby meeting different injection amount requirements and achieving the purpose of accurately controlling the gas injection amount.

[0035] Optionally, the first elastic member 34 is a spring, and the first elastic member 34 is sleeved on the outer circumference of the valve stem 33, which can ensure that the valve stem 33 is always subjected to an axial force, thereby preventing the valve stem 33 from deflecting and avoiding jamming.

[0036] Optionally, the distance between the first connecting portion 331 and the wall of the intake passage, and the distance between the second connecting portion 332 and the wall of the intake passage, are both 0.01 mm to 0.015 mm. Specifically, to ensure smooth axial movement of the valve stem 33, the first connecting portion 331 and the second connecting portion 332 are clearance-matched with the wall of the intake passage. This arrangement provides dual guidance during axial movement of the valve stem 33, preventing lateral deviation of the valve stem 33 during movement and causing jamming. In addition, the fitting clearance is small, which has a throttling effect and can form an effective cylindrical seal, further improving the sealing performance of the gas injector during operation; at the same time, the length of the second connecting portion 332 is H. When the valve stem 33 moves in the axial direction to S1 (H>S1), the lower end face of the valve stem 33 contacts the upper end face of the needle valve 22, pushing the needle valve 22 to open to a height of S2 (S2≤H-S1). At this time, the second connecting portion 332 is not completely separated from the air intake channel, and has a throttling effect, which can reduce the sensitivity of the gas volume change and improve the linearity of small gas volumes.

[0037] Optionally, in order to prevent the valve stem 33 from moving too far, a first limiting portion 11 is provided on the hole wall of the air intake channel, and the valve stem 33 is slidably provided on the inner wall of the first limiting portion 11. When the valve stem 33 moves, the first connecting portion 331 can be abutted against the top of the first limiting portion 11, thereby preventing the valve stem 33 from moving too far and causing damage to the air nozzle assembly 2.

[0038] Optionally, the gas injector further includes a seal 4, which is disposed at the end of the valve stem 33 away from the iron core 32 and is capable of abutting against the wall of the intake passage. Specifically, since gas can flow out through the gap between the valve stem 33 and the wall of the intake passage, to improve the sealing performance of the gas injector, the seal 4 is disposed at the end of the valve stem 33 so that the seal 4 abuts against the wall of the intake passage, thereby preventing gas from flowing out through the gap between the valve stem 33 and the wall of the intake passage.

[0039] Optionally, the gas injector further includes a second mounting seat 9, which is mounted on the hole wall of the air inlet channel, and one end of the valve stem 33 is slidably passed through the second mounting seat 9. When the gas injector is not working, the seal 4 can be tightly attached to the lower end surface of the second mounting seat 9 to ensure the sealing of the gas injector; when the gas injector is working, the seal 4 can be separated from the lower end surface of the second mounting seat 9.

[0040] Optionally, the sealing member 4 is a flat gasket made of elastic material. When the sealing member 4 is in close contact with the lower end surface of the second mounting seat 9, a sealing ring can be formed to achieve a plane seal.

[0041] Optionally, the hole wall of the air inlet passage is provided with a second limiting portion 12, and the iron core 32 can abut against the second limiting portion 12. Specifically, the iron core 32 is used to form a magnetic path. In order to effectively maintain the position of the iron core 32 and prevent it from moving, the hole wall of the air inlet passage is provided with the second limiting portion 12, and the iron core 32 can abut against the top of the second limiting portion 12, effectively preventing the iron core 32 from moving.

[0042] Optionally, the gas injector further includes an air intake pipe 10 and a first locking cap 7, one end of the air intake pipe 10 is inserted into the air intake channel and abuts against the iron core 32, and the air intake pipe 10 is connected to the second channel, and the air intake pipe 10 is threadedly connected to the shell 1 through the first locking cap 7 to ensure the sealing of the gas injector.

[0043] Alternatively, as Figure 1 and Figure 2 As shown, the gas injector further includes a first gasket 5, which is disposed between the second limiting portion 12 and the iron core 32. Specifically, the first gasket 5 can adjust the height of the iron core 32, thereby adjusting the contact force between the iron core 32 and the valve stem 33, and further adjusting the elastic force of the first elastic member 34. For example, when the thickness of the first gasket 5 is relatively small, the iron core 32 is positioned lower. In this case, the contact force between the iron core 32 and the valve stem 33 is relatively large, and the elastic force of the first elastic member 34 is also relatively large, thereby overcoming the reaction force of the gas within the gas injector and preventing the valve stem 33 from rebounding.

[0044] Optionally, the gas nozzle assembly 2 includes a shell 21, a needle valve 22 and a second elastic member 23. A first channel is provided in the shell 21. The needle valve 22 is slidably provided on the hole wall of the first channel. The valve stem 33 can be against the needle valve 22 and is used to open the first channel. The second elastic member 23 is configured to drive the needle valve 22 to always have a tendency to close the first channel. The needle valve 22 is pushed to move by the valve stem 33, thereby controlling the size of the opening of the first channel and further controlling the amount of gas injected. When the gas injector is not working, the second elastic member 23 can drive the needle valve 22 to close the first channel to ensure the sealing of the gas injector.

[0045] Optionally, the air nozzle assembly 2 further includes a first mounting seat 24, which is sleeved around the outer periphery of the needle valve 22. The second elastic member 23 has two ends connected to the first mounting seat 24 and the housing 21, respectively. Specifically, the air nozzle assembly 2 is provided with the first mounting seat 24, which is sleeved around the outer periphery of the needle valve 22. The sidewalls of the first mounting seat 24 are clearance-matched with the hole wall of the first passage, enabling the first mounting seat 24 to move along the length of the first passage, ensuring smooth movement of the needle valve 22 and preventing it from getting stuck. The second elastic member 23 is disposed between the first mounting seat 24 and the housing 21, and is capable of driving the first mounting seat 24 to move the needle valve 22, thereby closing the first passage.

[0046] Optionally, the air nozzle assembly 2 further includes a locking nut 25, which is threadedly connected to the needle valve 22, and the lower end surface of the locking nut 25 abuts against the top wall of the first mounting seat 24, thereby improving the stability of the connection between the first mounting seat 24 and the needle valve 22.

[0047] Alternatively, as Figure 1 and Figure 4 As shown, the wall of the first channel is provided with a third limiter 211, and the first mounting seat 24 can abut against the third limiter 211. Specifically, to limit the movement stroke of the needle valve 22, the wall of the first channel is provided with the third limiter 211. When the valve stem 33 drives the needle valve 22 to move, the first mounting seat 24 can abut against the third limiter 211, preventing the needle valve 22 from moving too far and thus affecting the sensitivity of closing the first channel. At the same time, it also reduces the risk of abnormal jetting caused by the reduced stiffness of the second elastic member 23, which leads to an increased lift of the needle valve 22.

[0048] Optionally, the gas injector further includes a second gasket 6, which is disposed between the second elastic member 23 and the housing 21. Specifically, the second gasket 6 can adjust the height of the second elastic member 23, thereby adjusting the height of the needle valve 22, and further adjusting the force acting to open the first channel. For example, when the thickness of the first gasket 5 is relatively large, the second elastic member 23 is positioned higher. At this time, the distance between the needle valve 22 and the valve stem 33 is relatively small. When the valve stem 33 pushes the needle valve 22 to move, the greater the elastic force of the second elastic member 23 that needs to be overcome, the greater the thrust of the valve stem 33 on the needle valve 22. This can overcome the reaction force of the gas in the gas injector, prevent the needle valve 22 from rebounding, and avoid gas leakage.

[0049] Optionally, the second elastic member 23 is a spring, and the second elastic member 23 is sleeved on the outer periphery of the needle valve 22 to ensure that the needle valve 22 is always subjected to an axial force, thereby preventing the needle valve 22 from deflecting and getting stuck.

[0050] Optionally, the gas injector further includes a second locking cap 8 , and the outer shell 21 is threadedly connected to the housing 1 through the second locking cap 8 to ensure the sealing of the gas injector.

[0051] The present invention provides a gas injector capable of accurately controlling the amount of gas injected. The working process of the gas injector is as follows:

[0052] The gas injector air inlet joint is connected to the air inlet pipe 10. When the electromagnet is not powered on, the valve stem 33 is under the action of the pre-tightening force of the first elastic member 34 and the needle valve 22 is under the action of the pre-tightening force of the second elastic member 23, so that the first channel is closed, and the various sealing surfaces of the gas injector are contacted and compressed to form a sealing ring belt; after the electromagnet is powered on, the valve stem 33 overcomes the pre-tightening force of the first elastic member 34 under the action of the electromagnetic force, and the valve stem 33 moves downward in the axial direction, the sealing member 4 is separated from the second mounting seat 9, and the plane seal is opened until it contacts the upper end surface of the needle valve 22, overcomes the pre-tightening force of the second elastic member 23, and the needle valve 22 is separated from the sealing cone surface of the housing 21. When the needle valve When the needle valve 22 is opened slightly, the second connecting part 332 is not completely separated from the hole wall separating the intake channel, which has a throttling effect, reducing the sensitivity of the injection volume, and the small gas volume of the gas injector changes linearly. When the needle valve 22 is fully opened, the second connecting part 332 is separated from the hole wall separating the intake channel, and the injection volume reaches the maximum. Due to the action of the third limit part 211, the injection volume tends to be stable; after the electromagnet is powered off, the valve stem 33 is quickly reset under the action of the pre-tightening force of the first elastic part 34. At this time, the pre-tightening force of the second elastic part 23 is relatively large, and the needle valve 22 can be closed quickly, reducing the risk of abnormal rebound opening of the needle valve 22 caused by excessive residual gas in the injector chamber.

[0053] Furthermore, the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions are possible for those skilled in the art without departing from the scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A gas injector, comprising: A housing (1), wherein the housing (1) is provided with an air intake passage passing through the housing (1); An air nozzle assembly (2), the air nozzle assembly (2) being connected to the housing (1), the air nozzle assembly (2) being provided with a first channel communicating with the air inlet channel; A control valve assembly (3), the control valve assembly (3) comprising an electromagnet structure (31), an iron core (32), a valve stem (33) and a first elastic member (34), the electromagnet structure (31) being arranged on the housing (1), the iron core (32) being arranged on the hole wall of the air intake passage, the iron core (32) being provided with a second channel communicating with the air intake passage, the valve stem (33) being slidably arranged on the hole wall of the air intake passage, the valve stem (33) being provided with a third channel communicating with the second channel, the third channel being communicated with the first channel, the first elastic member (34) being configured to drive the valve stem (33) to always have a tendency to abut against the iron core (32), the electromagnet structure (31) being capable of driving the valve stem (33) to separate from the iron core (32), the valve stem (33) being capable of abutting against or separating from the air nozzle assembly (2) so as to allow the air nozzle to The component (2) is opened or closed, characterized in that the valve stem (33) is provided with a first connecting portion (331) and a second connecting portion (332), the first connecting portion (331) is close to the iron core (32) relative to the second connecting portion (332), the second connecting portion (332) is in clearance fit with the hole wall of the air inlet channel, and the second connecting portion (332) can be separated from the hole wall of the air inlet channel; the distance between the first connecting portion (331) and the hole wall of the air inlet channel and the distance between the second connecting portion (332) and the hole wall of the air inlet channel are both 0.01mm to 0.015mm; when a small amount of gas is required, the gap between the second connecting portion (332) and the air inlet channel can play a throttling role to generate a small amount of gas; when a large amount of gas is required, the second connecting portion (332) is separated from the air inlet channel; a sealing member (4), the sealing member (4) being arranged at an end of the valve stem (33) away from the iron core (32), and the sealing member (4) being capable of abutting against a hole wall of the air inlet passage; a second mounting seat (9), the second mounting seat (9) being mounted on the hole wall of the air inlet passage, one end of the valve stem (33) being slidably disposed through the second mounting seat (9), and the sealing member (4) being able to be in close contact with the lower end surface of the second mounting seat (9) when the gas injector is not in operation; and the sealing member (4) being able to be separated from the lower end surface of the second mounting seat (9) when the gas injector is in operation; When the sealing member (4) is in close contact with the lower end surface of the second mounting seat (9), a sealing ring can be formed to achieve plane sealing.

2. A gas injector according to claim 1, characterized in that: The hole wall of the air inlet channel is provided with a first limiting portion (11), and the first connecting portion (331) can abut against the first limiting portion (11).

3. A gas injector according to claim 1, characterized in that: The hole wall of the air inlet passage is provided with a second limiting portion (12), and the iron core (32) can abut against the second limiting portion (12).

4. A gas injector according to claim 3, characterized in that: The gas injector further comprises a first gasket (5), which is arranged between the second limiting portion (12) and the iron core (32).

5. A gas injector according to any one of claims 1 to 4, characterized in that: The air nozzle assembly (2) comprises a housing (21), a needle valve (22) and a second elastic member (23); the housing (21) is provided with the first channel; the needle valve (22) is slidably arranged on the hole wall of the first channel; the valve stem (33) can abut against the needle valve (22) and is used to open the first channel; the second elastic member (23) is configured to drive the needle valve (22) to always have a tendency to close the first channel.

6. A gas injector according to claim 5, characterized in that: The air nozzle assembly (2) further comprises a first mounting seat (24), the first mounting seat (24) being sleeved on the outer periphery of the needle valve (22), and the two ends of the second elastic member (23) being connected to the first mounting seat (24) and the housing (21) respectively.

7. A gas injector according to claim 6, characterized in that: A third limiting portion (211) is provided on the hole wall of the first channel, and the first mounting seat (24) can abut against the third limiting portion (211).

8. A gas injector according to claim 6, characterized in that: The gas injector further comprises a second gasket (6), which is arranged between the second elastic member (23) and the housing (21).

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