Hydrogen ejector

Abstract

The invention relates to the field of hydrogen injection, and particularly discloses a hydrogen injector which comprises a coil assembly, a spring, a gas outlet connector, a gas inlet connector, a movable core assembly and a valve seat, and the coil assembly comprises a shell, a magnetic conductive support and a coil; the movable core assembly comprises a movable core, a buffer pad and a sealing pad, and an air inlet channel is formed in the movable core; the movable core is in sliding fit with the air outlet joint; the buffer pad and the sealing pad are fixed to the top and the bottom of the movable core respectively, a guide sleeve is arranged on the inner circumference of the coil, the upper portion of the movable core and the lower portion of the air inlet connector are both opposite to the guide sleeve, and the upper portion of the movable core is in sliding fit with the guide sleeve; the valve seat is connected with the air inlet connector, and a circulation hole is formed in the valve seat. The upper portion of the movable core is a centering portion, a gap is formed between the centering portion and the guide sleeve, and an upper ring groove is formed in the centering portion. According to the long-life hydrogen injector for the hydrogen internal combustion engine and the fuel cell system, the problem that the service life is relatively short can be solved.

Description

Technical Field

[0001] The invention relates to the field of hydrogen injection, and in particular to a hydrogen injector. Background Art

[0002] The main ways to utilize hydrogen energy are fuel cells and hydrogen internal combustion engines. In the hydrogen energy utilization mode of fuel cells or hydrogen internal combustion engines, the hydrogen injector is installed after the low-pressure reducing regulator. It is the core component of the hydrogen supply assembly in the fuel cell powertrain and the hydrogen internal combustion engine, and can realize the function of controlling the hydrogen flow.

[0003] The hydrogen injector is a normally closed valve, mainly composed of a coil assembly, a moving core assembly, a valve seat, an air inlet interface, an air outlet interface, a guide sleeve and other structures. The main working principle is that when the hydrogen injector is powered on, the electromagnetic coil generates an electromagnetic force to lift the moving core assembly to overcome the opening resistance such as gas pressure, the hydrogen injector opens, and hydrogen enters the downstream through the internal flow channel of the hydrogen injector; when the power is off, the electromagnetic force disappears, the moving core is reset under the action of the reset spring, and the hydrogen injector is closed. The injection pulse width (i.e., the opening time) of each nozzle on the hydrogen injector is controlled by pulse width modulation (PWM) to achieve precise control of the hydrogen flow rate.

[0004] When the hydrogen injector is turned on, the moving core assembly slides to the side away from the air outlet interface. When the hydrogen injector is turned off, the moving core assembly will reset under the action of the spring force. At this time, there is a collision between the moving core assembly and the valve seat, resulting in a loud noise. The moving core assembly is prone to deformation after long-term use. Secondly, due to the special nature of the hydrogen medium, hydrogen cannot provide lubrication for the internal moving parts of the hydrogen injector like gasoline, diesel and other fuels. Therefore, during the sliding process of the moving core assembly, it will rub against the guide sleeve and other structures. Due to the need for frequent opening and closing, the moving core assembly will be worn after a period of use, resulting in a short service life.

[0005] Later, a hydrogen injector as disclosed in application number CN202122031119.3 appeared, including a main body, on which a hydrogen inlet, a hydrogen outlet, an air inlet pipe and an air outlet pipe are provided, at least two injection chambers are formed on the main body, and the injection chambers are arranged along the length direction of the main body. A solenoid valve is correspondingly arranged in the injection chamber, and the solenoid valve includes a shell, a moving iron core, a static iron core, a valve seat, and a reset spring. An elastic gasket is arranged at the contact position between the valve seat and the moving iron core, and a center hole is arranged in the center of the elastic gasket. The elastic gasket is sleeved on the valve seat through the center hole and connected to the moving iron core. The center hole and the valve seat are arranged concentrically. When the moving iron core moves, part of the center hole moves synchronously with the moving iron core.

[0006] This patent arranges an elastic gasket outside the moving iron core to center the moving iron core to avoid collision between the moving iron core and the valve body. However, it is found in actual use that the hardness of the elastic gasket is relatively low and it is easily worn during use. Once the elastic gasket is worn, the moving iron core can no longer be centered, so the service life of the hydrogen injector is still relatively short. Summary of the invention

[0007] The present invention is intended to provide a hydrogen injector to solve the problem of relatively short service life.

[0008] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a hydrogen injector, comprising a coil assembly, a spring, an air outlet joint, and an air inlet joint, a moving core assembly and a valve seat arranged in sequence along the axial direction, the coil assembly comprising a shell, a magnetic conductive bracket and a coil; the moving core assembly comprising a moving core, a buffer pad and a sealing pad, the upper end of the air outlet joint is connected to the shell, an air inlet channel is axially arranged in the moving core, the air inlet channel is connected to the air inlet joint, and the spring is located between the air inlet joint and the moving core; the lower part of the moving core is located in the air outlet joint and slides with the air outlet joint; the buffer pad and the sealing pad are respectively fixed to the top and bottom of the moving core, a guide sleeve is provided on the inner circumference of the coil, the upper part of the moving core and the lower part of the air inlet joint are both opposite to the guide sleeve, and the upper part of the moving core slides with the guide sleeve; the valve seat is connected to the air inlet joint, and the valve seat is provided with a flow hole that can be sealed by the sealing pad and can be connected with the air inlet channel; the upper part of the moving core is a centering part, a gap is formed between the centering part and the guide sleeve, and an upper annular groove is provided on the centering part.

[0009] The beneficial effects of this program are:

[0010] 1. Since the moving core of the hydrogen injector slides back and forth under the action of magnetic force and the elastic force of the spring, the moving core is prone to lateral deviation during the sliding process, which increases the pressure between the side wall of one side of the moving core and the outer guide sleeve, air outlet joint and other structures, thereby causing serious wear on this side, that is, it also causes different degrees of wear on the two opposite sides of the moving core.

[0011] When the hydrogen injector in the present scheme is closed, the sealing gasket seals the flow hole, and hydrogen cannot flow out through the flow hole; when the hydrogen injector is opened, the sealing gasket moves upward with the moving core to open the flow hole. During the opening process, the buffer gasket has not yet completely abutted against the intake joint, and hydrogen will flow into the upper annular groove from between the intake joint and the moving core through the gap between the centering part and the guide sleeve. When the moving core is offset, a local high-pressure area is formed in the annular groove area. The part of the moving core located in the local high-pressure area is subjected to greater pressure, while the other side opposite to it is subjected to less pressure. The moving core will automatically center under the action of this unbalanced pressure to avoid serious wear of the side wall on one side, thereby increasing the service life of the hydrogen injector.

[0012] Secondly, when the moving core moves upward, the sealing gasket moves upward synchronously, so after the hydrogen just enters the intake joint, it can flow downward from all around the center, and when a local high-pressure area is formed in the annular groove area, the moving core can be automatically centered better. And because the gap between the moving core and the guide sleeve is not directly connected to the intake channel, there will be no interference between the flow of hydrogen in the intake channel and the gap.

[0013] 2. The reduction in the diameter of the center part can, on the one hand, reduce the contact with the guide sleeve, thereby reducing wear. On the other hand, due to the existence of the gap, when the hydrogen injector is turned on, the hydrogen can flow quickly from the gap into the upper ring groove in a shorter time, that is, a more obvious and faster airflow can be formed in the gap and the upper ring groove, accelerating the formation of a local high-pressure area, thereby centering the moving core more quickly.

[0014] Furthermore, a plurality of upper ring grooves are provided, and the plurality of upper ring grooves are axially arranged on the centering portion.

[0015] The beneficial effects of this solution are as follows: the number of upper annular grooves increases, and when the moving core is offset, more local high-pressure areas can be formed, and the force generated to center the moving core is greater, which is conducive to automatic centering of the moving core.

[0016] Furthermore, the lower part of the moving core is a sealing part, and the sealing part is slidably matched with the air outlet joint.

[0017] The beneficial effect of this solution is that the sealing portion can guide the sliding of the moving core and reduce the displacement of the moving core.

[0018] Furthermore, a lower annular groove is provided on the sealing portion.

[0019] The beneficial effect of this solution is that when hydrogen flows through the lower annular groove, if the moving core is offset, a local high-pressure area can be formed at the position of the lower annular groove, thereby further increasing the force that causes the moving core to be centered, which is conducive to the automatic centering of the moving core.

[0020] Furthermore, a connecting portion is provided between the centering portion and the sealing portion, and a diameter of the connecting portion is smaller than diameters of the centering portion and the sealing portion.

[0021] The beneficial effects of this solution are as follows: an annular groove is formed between the connecting portion and the guide sleeve in this solution, and compared with the upper annular groove, the depth of the annular groove here is greater and can accommodate gas. Therefore, during the opening of the hydrogen injector, more hydrogen can flow through the upper annular groove and enter the groove formed at the connecting portion, so a greater force can be formed at the upper annular groove position, which is further beneficial to the centering of the moving core.

[0022] Furthermore, the sealing portion and the centering portion have the same diameter.

[0023] The beneficial effect of this solution is that the moving core in this solution can be installed into the guide sleeve from bottom to top or from top to bottom, which makes installation more convenient.

[0024] Furthermore, an upper groove is provided at the bottom of the air intake joint, and a lower groove connected to the air intake channel is provided at the top of the moving core. The upper groove is opposite to the lower groove, and the upper and lower ends of the spring are respectively located in the upper groove and the lower groove.

[0025] The beneficial effect of this solution is that the side walls of the upper groove and the lower groove in this solution can limit the spring.

[0026] Furthermore, the diameter of the middle portion of the spring is smaller than the diameters of the two ends.

[0027] The beneficial effects of this solution are as follows: compared with ordinary springs, the spring in this solution is designed to be concave, which can assist in positioning the moving core, improve the centering and stability of the moving core, reduce the wear of the moving core, and increase the service life of the hydrogen injector:

[0028] Ordinary springs are cylindrical. If the two ends of an ordinary spring have a clearance fit with the air intake joint and the moving core, the spring can only serve to reset the moving core. If the two ends of an ordinary spring have an interference fit with the air intake joint and the moving core, during the compression and resetting process of the spring, there will be movement between the outer circle of the spring and the moving core, but the interference fit will cause a large friction force between the spring and the moving core, and this friction force may cause the spring to get stuck.

[0029] The middle part of the spring in this solution is concave, which increases the gap between the spring and the lower groove and the upper groove, thereby preventing the spring from being worn. At the same time, even if the spring is interference-fitted with the air intake joint and the moving core, the middle part of the spring will not contact the side walls of the upper groove and the lower groove, and there is no risk of the spring getting stuck.

[0030] Secondly, when the moving core tends to be eccentric, the outer circle of the end of the spring will be eccentric, causing the spring to bend and deform. At this time, the spring will generate an automatic radial force to push the moving core back to the center to ensure that the moving core is in a centered state.

[0031] Furthermore, a plurality of flow holes are provided, and the upper ends of the plurality of flow holes are all directly facing the sealing gasket; an outlet is provided at the lower end of the valve seat, and the plurality of flow holes are all connected to the outlet.

[0032] The beneficial effects of this solution are: multiple flow holes can disperse the force, reduce the impact on the sealing gasket when the hydrogen injector is closed, increase the service life of the sealing gasket, and help to increase the service life of the hydrogen injector. In addition, multiple flow holes are conducive to mixing the gas with the air after entering the intake duct, so that the hydrogen burns more fully and improves the efficiency of the internal combustion engine.

[0033] Furthermore, an annular flow guide channel is provided at the lower part of the moving core, the cross section of the flow guide channel along the axial direction is L-shaped, a plurality of air outlet channels are provided between the air inlet channel and the flow guide channel, and the air outlet channels are distributed along the circumference of the moving core.

[0034] The beneficial effect of this scheme is that the top of the guide channel in this scheme is opposite to the contact position between the moving core and the gas outlet joint. During the opening process of the hydrogen injector, the hydrogen flowing through the gap between the centering part and the guide sleeve can enter the guide channel after flowing downward, and finally flow out from the flow hole. In this way, during the opening process of the hydrogen injector, airflow is further formed in the gap, which is beneficial to the centering of the moving core. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A front view of an embodiment of the present invention;

[0036] Figure 2 for Figure 1 Enlarged view of the middle moving core assembly;

[0037] Figure 3 for Figure 1 Enlarged view of the middle valve seat;

[0038] Figure 4 for Figure 3 Top view of the . DETAILED DESCRIPTION

[0039] The following is further described in detail through specific implementation methods:

[0040] The figure marks in the drawings of the specification include: air inlet connector 1, upper groove 11, coil assembly 2, magnetic bracket 3, coil 4, spring 5, moving core assembly 6, buffer pad 61, moving core 62, sealing pad 63, upper ring groove 64, lower ring groove 65, air inlet channel 66, air outlet channel 67, guide channel 68, lower groove 69, guide sleeve 7, air outlet connector 8, valve seat 9, gas groove 91, flow hole 92, limit groove 93, outlet 94, protrusion 95.

[0041] Example

[0042] The embodiment is basically as follows Figure 1 , Figure 2 and Figure 3 As shown, a hydrogen injector includes a coil assembly 2, a spring 5, an air outlet connector 8, and an air inlet connector 1, a moving core assembly 6, and a valve seat 9 which are coaxially arranged in sequence vertically. The coil assembly 2 includes a housing, a magnetic support 3, and a coil 4. The moving core assembly 6 includes a moving core 62, a buffer pad 61, and a sealing pad 63. The upper part of the moving core 62 and the lower part of the air inlet connector 1 are both located in the housing. The air inlet connector 1 is fixed to the housing. Specifically, the air inlet connector 1 in this embodiment is welded to the housing.

[0043] The outer periphery of the moving core 62 is provided with a guide sleeve 7, the upper part of the moving core 62 and the bottom of the air inlet connector 1 are opposite to the guide sleeve 7, the guide sleeve 7 is fixed to the air inlet connector 1, and specifically the guide sleeve 7 is welded to the air inlet connector 1. The coil 4 is located between the housing and the guide sleeve 7, and the upper end of the coil 4 is higher than the upper part of the moving core 62, the magnetic conductive bracket 3 is located between the coil 4 and the housing, and the coil 4 is arranged on the magnetic conductive bracket 3.

[0044] The top of the moving core 62 is provided with a lower groove 69, and the bottom of the air inlet connector 1 is provided with an upper groove 11. The upper groove 11, the lower groove 69 and the moving core 62 are coaxial. The upper and lower ends of the spring 5 are respectively located in the upper groove 11 and the lower groove 69, and the upper and lower ends of the spring 5 are respectively interference fit with the side walls of the upper groove 11 and the lower groove 69. The diameter of the middle part of the spring 5 is smaller than the diameter of the upper and lower ends. Therefore, when the spring 5 is compressed, the middle part will not contact the side walls of the upper groove 11 and the lower groove 69, so there is no risk of the spring 5 being stuck. The spring 5 in this embodiment is in a compressed state, so that the spring 5 always maintains a large elastic force.

[0045] A buffer pad 61 is bonded to the top of the moving core 62. The diameter of the buffer pad 61 is smaller than the diameter of the top of the moving core 62. The buffer pad 61 is provided with a hole facing the lower groove 69 to ensure the normal installation of the spring 5. An air intake channel 66 is coaxially provided in the moving core 62. The upper end of the air intake channel 66 is connected to the lower groove 69. Therefore, the air intake channel 66 in this embodiment is connected to the air intake joint 1 through the cooperation of the upper groove 11 and the lower groove 69.

[0046] The moving core 62 is composed of a centering part, a connecting part and a sealing part from top to bottom. The diameters of the centering part and the sealing part are equal and larger than the diameter of the connecting part, so that an annular groove is formed on the outer periphery of the connecting part. The diameter of the centering part is smaller than the inner diameter of the guide sleeve 7, so that a gap is formed between the centering part and the guide sleeve 7. A plurality of upper annular grooves 64 are provided on the side wall of the centering part along the axial direction. The upper annular grooves 64 in this embodiment are perpendicular to the axial direction of the centering part.

[0047] The top of the outlet connector 8 is located in the housing and fixed to the housing. Specifically, the outlet connector 8 in this embodiment can be fixed to the housing by welding, bonding and threaded connection. The valve seat 9 is installed in the outlet connector 8, and the valve seat 9 is welded to the outlet connector 8. The sealing part is located in the outlet connector 8 and slidably cooperates with the outlet connector 8. The sealing part is also provided with a plurality of lower annular grooves 65 along the axial direction, and a sealing gasket 63 is bonded to the bottom of the sealing part. The distance between the top of the valve seat 9 and the bottom of the inlet connector 1 is greater than the sum of the length of the moving core 62 and the thickness of the buffer pad 61 and the thickness of the sealing gasket 63, so as to ensure that the moving core 62 can slide up and down vertically.

[0048] An annular flow guide channel 68 is provided at the lower part of the sealing part, and the vertical cross section of the flow guide channel 68 is L-shaped, so that the gas entering the gap between the guide sleeve 7 and the centering part can flow downward into the flow guide channel 68. A plurality of gas outlet channels 67 are provided between the gas inlet channel 66 and the flow guide channel 68, and all the gas outlet channels 67 are evenly distributed along the circumference of the gas inlet channel 66, and are used to connect the gas inlet channel 66 and the flow guide channel 68.

[0049] A limiting groove 93 is provided on the top of the valve seat 9, and the bottom of the sealing part is located in the limiting groove 93. The bottom diameter of the sealing part is smaller than the diameter of the limiting groove 93, so that the bottom of the sealing part and the side wall of the limiting groove 93 form a guide gap for gas to flow through. Figure 4 As shown, the side wall of the limiting groove 93 facing the sealing gasket 63 is evenly provided with four flow holes 92 along the circumferential direction. The flow holes 92 connect the limiting groove 93 and the outlet 94. The tops of the four flow holes 92 are all facing the sealing gasket 63, ensuring that the upper ends of the flow holes 92 can be sealed by the sealing gasket 63. In this embodiment, a circle of protrusions 95 are provided on the outer periphery of the top of the flow hole 92, and the top of the protrusion 95 abuts against the sealing gasket 63 to ensure that the flow hole 92 is sealed. A gas groove 91 is also provided on the side of the protrusion 95 away from the sink, and the end of the gas groove 91 away from the protrusion 95 extends to the outside of the sealing gasket 63. The protrusion 95 in this solution is located between the sink and the gas groove 91. Therefore, when the sealing gasket 63 seals the flow hole 92, the sealing gasket 63 is elastic, so the sealing gasket 63 is deformed at the position relative to the sink, the protrusion 95 and the gas groove 91 under the action of pressure, and becomes an inverted U shape at the protrusion 95, thereby increasing the contact area with the protrusion 95 and improving the sealing effect. One end of the gas groove 91 extends to the outside of the sealing gasket 63, so when the hydrogen injector is turned on, the depth of the gas groove 91 is greater, so that more gas flows through the gas groove 91 to the side close to the flow hole 92, thereby promoting the hydrogen to flow out of the flow hole 92.

[0050] The inner wall of the guide sleeve 7, the outer wall of the moving core 62 and the side wall of the air outlet joint 8 facing the moving core 62 in this embodiment are sprayed with a wear-resistant coating or a self-lubricating coating to reduce friction with the moving core 62 and reduce wear when the moving core 62 slides.

[0051] The specific implementation process is as follows:

[0052] In this embodiment, the air inlet connector 1, the magnetic support 3, the moving core 62 and the air outlet connector 8 are all made of magnetic conductive materials, and other parts are all made of non-magnetic conductive materials.

[0053] Initially, the bottom of the moving core 62 is pressed on the valve seat 9 by the action of the spring 5, and the flow hole 92 is sealed. At this time, the hydrogen injector is in a sealed state. When the hydrogen injector is turned on, the coil 4 is started, and the coil 4 works to generate electromagnetic force, so that the moving core 62 slides upward. When the moving core 62 starts to slide upward, the sealing gasket 63 no longer seals the flow hole 92, and the buffer gasket 61 has not yet completely abutted against the bottom of the intake joint 1. Therefore, after the hydrogen enters from the intake joint 1, it enters the gap between the moving core 62 and the intake joint 1 and enters the gap between the moving core 62 and the guide sleeve 7 and continues to flow downward, and finally flows out of the flow hole 92 through the guide channel 68 and the guide gap. Therefore, a downward airflow is formed on the outside of the moving core 62. When the moving core 62 is eccentric, an obvious local high-pressure area is formed at the upper ring groove 64 and the lower ring groove 65, which promotes the centering of the moving core 62.

[0054] Finally, the buffer pad 61 abuts against the air inlet connector 1, and the hydrogen flows out from the flow hole 92 through the air inlet connector 1, the air inlet channel 66, the air outlet channel 67 and the guide channel 68, completing the injection of the hydrogen.

[0055] When the hydrogen injector needs to be closed, the coil 4 is closed, and the moving core 62 is reset downward under the elastic force of the spring 5 , so that the sealing gasket 63 is pressed against the valve seat 9 again to seal the flow hole 92 .

[0056] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A hydrogen injector, comprising a coil assembly, a spring, an air outlet joint, and an air inlet joint, a moving core assembly and a valve seat arranged in sequence along the axial direction, wherein the coil assembly comprises a housing, a magnetic conductive bracket and a coil; the moving core assembly comprises a moving core, a buffer pad and a sealing pad, characterized in that: The upper end of the air outlet joint is connected to the outer shell, and an air inlet channel is axially provided in the moving core, the air inlet channel is connected to the air inlet joint, and the spring is located between the air inlet joint and the moving core; the lower part of the moving core is located in the air outlet joint and slidingly cooperates with the air outlet joint; the buffer pad and the sealing pad are respectively fixed on the top and bottom of the moving core, and a guide sleeve is provided on the inner periphery of the coil, the upper part of the moving core and the lower part of the air inlet joint are opposite to the guide sleeve, and the upper part of the moving core is slidingly cooperated with the guide sleeve; the valve seat is connected to the air inlet joint, and the valve seat is provided with a flow hole that can be sealed by the sealing pad and can be connected to the air inlet channel; the upper part of the moving core is a centering part, a gap is formed between the centering part and the guide sleeve, and an upper annular groove is provided on the centering part.

2. A hydrogen injector according to claim 1, characterized in that: A plurality of upper ring grooves are provided, and the plurality of upper ring grooves are axially arranged on the centering portion.

3. A hydrogen injector according to claim 2, characterized in that: The lower part of the moving core is a sealing part, and the sealing part is slidably matched with the air outlet joint.

4. A hydrogen injector according to claim 3, characterized in that: The sealing part is provided with a lower annular groove.

5. A hydrogen injector according to claim 4, characterized in that: A connecting portion is provided between the centering portion and the sealing portion, and a diameter of the connecting portion is smaller than diameters of the centering portion and the sealing portion.

6. A hydrogen injector according to claim 3 or 4, characterized in that: The sealing part and the centering part have the same diameter.

7. A hydrogen injector according to claim 1, characterized in that: An upper groove is provided at the bottom of the air inlet joint, and a lower groove connected to the air inlet channel is provided at the top of the moving core. The upper groove is opposite to the lower groove, and the upper and lower ends of the spring are respectively located in the upper groove and the lower groove.

8. A hydrogen injector according to claim 7, characterized in that: The diameter of the spring in the middle is smaller than that at the ends.

9. A hydrogen injector according to claim 1, characterized in that: A plurality of flow holes are provided, and the upper ends of the plurality of flow holes are all directly facing the sealing pad; an outlet is provided at the lower end of the valve seat, and the plurality of flow holes are all communicated with the outlet.

10. A hydrogen injector according to claim 9, characterized in that: An annular flow guide channel is provided at the lower part of the moving core, and the cross section of the flow guide channel along the axial direction is L-shaped. A plurality of air outlet channels are provided between the air inlet channel and the flow guide channel, and the air outlet channels are distributed along the circumference of the moving core.

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