Gas ejector with hydraulic damping

Abstract

The invention relates to the field of gas fuel engines, in particular to a gas injector with hydraulic damping. Which comprises an electromagnetic valve unit, a valve unit and a reset elastic piece, the electromagnetic valve unit comprises an armature, the valve unit comprises a valve needle, and the electromagnetic valve is characterized in that a damping unit is arranged on the side, away from the valve needle, of the armature and comprises a damping valve body, a plunger, a cone valve and a first elastic piece; one end of the plunger is located in the inner cavity and is in sliding seal with the damping valve body, a damping chamber is formed between the plunger and the damping valve body, and the plunger can slide along with the valve needle; an oil inlet channel which is opposite to the plunger and communicated with the damping chamber is arranged on the damping valve body, the cone valve is opposite to the oil inlet channel and can open and close the oil inlet channel, a center damping hole is formed in the cone valve, and the first elastic piece is connected with the cone valve and used for enabling the cone valve to close the oil inlet channel. According to the gas ejector with hydraulic damping, the electromagnetic response speed can be increased while the damping effect is provided.

Description

Technical Field

[0001] This invention relates to the field of gas fuel engines, and more specifically to a gas injector with hydraulic damping. Background Technology

[0002] In the field of internal combustion engines, clean energy sources such as hydrogen and natural gas cause less environmental pollution, so the direct application of these gaseous energy sources has gradually become a research hotspot. However, the physicochemical properties of these gaseous fuels (such as the high diffusivity and low viscosity of hydrogen, and the low surface tension of natural gas) are significantly different from those of traditional liquid fuels, requiring targeted design of injection systems.

[0003] The key to designing a gas ejector lies in meeting the requirements for rapid response and stable operation. The purpose of a common solenoid valve type ejector is to achieve rapid response, but the impact on the sealing surface when the ejector is in continuous reciprocating motion cannot be ignored.

[0004] To address the issue of impact on the sealing surface, existing gas injectors typically employ a method similar to that described in application number 202411355919.2, which is used for injecting gaseous fuel. This includes an electromagnetic actuator with an armature, an inner pole, and a coil; a closing element with a valve needle and an armature post, wherein the valve needle releases at a sealing seat located at a first end of the gas injector and closes the gas path; the armature is connected to the armature post, and the armature post is operatively connected to the valve needle; a sealed lubricant chamber filled with a liquid lubricant and also with gas, and the armature and armature post are arranged within the lubricant chamber, where the lubricant provides lubrication; and a reset element that resets the closing element to a position where... In the initial closed position; a damping device having a damping chamber and a throttling section, wherein the damping device is arranged in a lubricant chamber, wherein the damping device is configured to dampen the closing movement of a closing element; a compensation chamber, which is part of the lubricant chamber, and liquid and gas are arranged in the compensation chamber; and a filling device configured to fill the damping chamber with liquid from the compensation chamber, wherein the filling device has a connection path between the compensation chamber and the damping chamber, wherein a valve assembly is arranged in the connection path, wherein the minimum cross-section of the connection path is greater than the maximum cross-section of the throttling section of the damping device, wherein the valve assembly cuts off the connection path in a first direction from the damping chamber to the compensation chamber and releases it in a second direction from the compensation chamber to the damping chamber.

[0005] While the aforementioned gas injector can buffer the valve needle through a damping device, thereby reducing the impact on the sealing surface, the compensation chamber within the injector is connected to the lubricant chamber and the area where the armature is located via a port, causing the armature to be immersed in liquid. This design leads to a loss of electromagnetic force and a slower electromagnetic response. Summary of the Invention

[0006] The present invention aims to provide a gas injector with hydraulic damping to improve electromagnetic response speed while providing a damping effect.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a gas injector with hydraulic damping, comprising a solenoid valve unit, a valve unit, and a reset spring element. The solenoid valve unit includes an armature, and the valve unit includes a valve needle. A damping unit is provided on the side of the armature away from the valve needle. The damping unit includes a damping valve body, a plunger, a cone valve, and a first elastic element. The damping valve body has an inner cavity. One end of the plunger is located in the inner cavity and slides and seals with the damping valve body. A damping chamber is formed between the plunger and the damping valve body. The plunger can slide with the valve needle. The damping valve body has an oil inlet channel opposite to the plunger and communicating with the damping chamber. The cone valve is opposite to the oil inlet channel and can open and close the oil inlet channel. The cone valve has a central damping hole. The first elastic element is connected to the cone valve and is used to close the oil inlet channel by the cone valve.

[0008] The beneficial effects of this plan are: 1. In this design, the damping unit is located on the side of the armature away from the valve needle. When the gas injector is working, the damping oil only enters the damping chamber and does not come into contact with the armature or other structures, thus avoiding the loss of electromagnetic force. Therefore, the electromagnetic response speed of the gas injector in this design is faster.

[0009] 2. When the gas ejector is working, the high-speed movement of the valve needle and other structures causes friction between them and adjacent structures, generating heat. In this design, the damping oil only enters the damping chamber, and there is a large distance between the damping chamber and the high-speed moving structures such as the valve needle. The heat from the valve needle and other structures is not easily transferred to the damping oil, so the temperature of the damping oil in this design will not rise. Vapor will not form in the damping chamber due to the increased temperature of the damping oil, allowing the damping oil to almost fill the damping chamber. Therefore, compared with existing gas ejectors with damping devices, the damping chamber in this design is smaller. Also, because there is no need to set up a chamber to separate the gas and damping oil, the structure of the damping unit is simpler, and the reliability of the damping unit is higher. Furthermore, the gas ejector in this design is smaller and more suitable for use in places with limited installation space.

[0010] Furthermore, the oil inlet channel is provided with a first conical surface at one end near the damping chamber, and the cone valve is provided with a second conical surface that is opposite to and can abut against the first conical surface.

[0011] The beneficial effects of this solution are as follows: when the second conical surface closes the first conical surface, the sealing effect of the cone valve on the oil inlet channel is better. When the cone valve moves away from the oil inlet channel, it can quickly open the oil inlet channel. At this time, the design of the first conical surface can also guide the cone valve, so that the cone valve will not tilt when it slides into the oil inlet channel again, thereby ensuring that the cone valve can seal the oil inlet channel again.

[0012] Furthermore, the plunger is provided with a groove, and the end of the first elastic element away from the cone valve is located in the groove and abuts against the side wall of the groove.

[0013] The beneficial effects of this solution are: the groove design can limit and guide the first elastic element, ensuring that the first elastic element can be compressed or elongated along the length direction.

[0014] Furthermore, a guide rod is provided on the side of the plunger away from the cone valve. One end of the guide rod is opposite to the valve needle, and the other end can push the plunger to slide closer to the cone valve.

[0015] The beneficial effects of this solution are: the guide rod ensures that the plunger can slide with the valve needle, and when the gas injector is de-energized, the plunger can transfer damping to the valve needle, reducing the collision between the valve needle and the sealing surface.

[0016] Furthermore, the travel of the guide rod is greater than the travel of the plunger.

[0017] The beneficial effects of this design are as follows: When the gas injector is energized, the guide rod slides a greater distance towards the valve needle than the plunger slides towards the valve needle, thus creating a gap between the guide rod and the plunger. When the power is off, the guide rod resets along with the valve needle. At this point, the guide rod does not push the plunger to slide, so the first stage of the valve needle's reset is not subject to damping.

[0018] The guide rod continues to reset before sliding with the plunger and resetting the plunger. In the initial stage of plunger reset, the distance between the plunger end near the oil inlet channel and the oil inlet channel is relatively large. Therefore, the cone valve cannot close the oil inlet channel under the action of the first elastic element. At this time, the oil inlet channel is in the open state, and the damping oil in the damping chamber can be discharged from the space between the outer wall of the cone valve and the oil inlet channel and the central damping hole at the same time. That is, at this time, the damping unit valve needle provides a small damping effect.

[0019] As the guide rod continues to reset, the distance between the plunger and the oil inlet channel further decreases. Under the action of the first elastic element, the cone valve closes the oil inlet channel. At this time, the damping oil in the damping chamber can only be discharged from the central damping hole. Therefore, the damping unit can provide a greater effect for the valve needle.

[0020] In summary, during the process of the gas injector closing and the valve needle resetting, the valve needle goes through three stages: an undamped stage, a stage with a small damping effect, and a stage with a large damping effect. This causes the valve needle speed to gradually decrease. In the first and second stages, the valve needle can also maintain a faster resetting speed, making the gas injector respond faster when it closes, thus enabling it to spray the required amount of gas more accurately.

[0021] Furthermore, the damping unit also includes a second elastic element, one end of which abuts against the plunger and is used to slide the plunger toward the side closer to the valve needle when the valve needle moves away from the plunger.

[0022] The beneficial effects of this solution are as follows: When the amount of gas to be ejected is small, the energization time of the gas injector is short, thus allowing less time for the damping oil to enter the damping chamber. In this solution, when the gas injector is energized, the plunger can slide rapidly under the action of the second elastic element, allowing the cone valve to quickly open the oil inlet channel, thereby enabling the damping oil to enter the damping chamber quickly in a shorter time. Therefore, even if the energization time of the gas injector is short, the damping unit in this solution can still achieve a damping effect.

[0023] Furthermore, the damping unit also includes an oil injection body, which has a cavity. One end of the damping valve body is located in the cavity and is slidably sealed with the oil injection body. An oil injection chamber is formed between the damping valve body and the oil injection body, and the oil inlet channel is connected to the oil injection chamber.

[0024] The beneficial effects of this solution are: the design of the oil injection chamber allows the damping oil to enter the damping chamber quickly and automatically.

[0025] Furthermore, the side wall of the oil filling chamber is provided with an oil inlet, and the oil inlet is provided with a seal for sealing the oil inlet.

[0026] The beneficial effects of this solution are: the damping oil can be added to the oil filling chamber more conveniently through the oil inlet, making it easier to replenish the damping oil in the oil filling chamber in a timely manner.

[0027] Furthermore, a flexible sealing unit is provided between the armature and the damping valve body. The flexible sealing unit includes a flexible sleeve, which is fitted onto the guide rod. The inner side of the flexible sleeve forms a sealing space that is only connected to the damping chamber.

[0028] The beneficial effects of this solution are as follows: When the guide rod slides, the damping oil enters the flexible sleeve and is limited by the flexible sleeve, preventing leakage to the valve needle position. This further avoids the damping oil from contacting the valve needle, which would cause the temperature of the damping oil to rise. Therefore, the damping oil in this solution is less likely to evaporate due to high temperature. Attached Figure Description

[0029] Figure 1This is a frontal vertical sectional view of an embodiment of the present invention; Figure 2 This is a front vertical sectional view of the flexible sealing unit and damping unit in the embodiments of the present invention; Figure 3 for Figure 2 Enlarged view of point A in the middle. Detailed Implementation

[0030] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: sealing seat 1, valve needle 2, return spring 21, pole shoe 22, armature 23, coil 3, damping valve body 4, damping chamber 41, oil inlet channel 42, guide rod 5, bellows 6, mounting seat 61, pressure sleeve 62, oil injection body 7, oil injection chamber 71, oil inlet 72, seal 73, plunger 8, groove 81, connecting hole 82, second elastic element 83, first elastic element 84, cone valve 9, and center damping hole 91.

[0031] Example The implementation examples are basically as follows Figure 1 , Figure 2 and Figure 3 As shown, a gas injector with hydraulic damping includes a solenoid valve unit, a valve unit, and a reset spring. The solenoid valve unit includes an armature 23, an iron core, a coil 3, and a pole shoe 22. The valve unit includes a valve needle 2 and a sealing seat 1. The lower part of the valve needle 2 abuts against the lower end of the sealing seat 1 to seal the sealing seat 1. The upper part of the valve needle 2 passes through the sealing seat 1 upward and extends upward to the top of the sealing seat 1. The reset spring, pole shoe 22, and armature 23 are arranged sequentially from bottom to top. The reset spring is a reset spring 21. The valve needle 2 passes through the reset spring 21, pole shoe 22, and armature 23 sequentially from bottom to top. The coil 3 is sleeved on the outer periphery of the pole shoe 22 and the armature 23. When the coil 3 is energized, a magnetic attraction is formed between the pole shoe 22 and the armature 23, pushing the armature 23 downward. This, in turn, pushes the valve needle 2 downward against the preload of the reset spring 21, opening the sealing seat 1. After the coil 3 is de-energized, the electromagnetic force disappears, the reset spring 21 releases its elastic potential energy, the valve needle 2 and the armature 23 reset, and the valve needle 2 re-seals the sealing seat 1. The specific structure, installation method, and movement process of the solenoid valve unit, valve unit, and reset spring in this embodiment are the same as those in the prior art, and will not be described again in this embodiment.

[0032] A damping unit is provided above the armature 23. The damping unit includes a damping valve body 4, a plunger 8, a cone valve 9, a first elastic element 84, a second elastic element 83, and an oil injection body 7. The damping valve body 4 has a damping chamber 41 with its opening facing downward. The plunger 8 is located in the damping chamber 41, and a guide rod 5 is provided between the plunger 8 and the valve needle 2. The plunger 8, the guide rod 5, and the valve needle 2 are coaxially arranged. A flexible sealing unit is also provided between the plunger 8 and the armature 23. The flexible sealing unit includes a flexible sealing sleeve, a mounting base 61, and a pressure sleeve 62. In this embodiment, the flexible sealing sleeve is a bellows 6. The upper and lower ends of the bellows 6 are fixed to the pressure sleeve 62 and the mounting base 61 respectively by interference fit, thread, or laser welding. The upper end of the valve needle 2 is interference-fitted with the mounting base 61. The guide rod 5 is located inside the bellows 6 and is clearance-fitted with the bellows 6. Because there are gaps between the armature 23, iron core, coil 3, pole shoe 22 and other structures, as well as between the valve needle 2 and the armature 23, iron core, coil 3, pole shoe 22 and other structures, the gaps formed between the bellows 6 and the mounting base 61 and the adjacent structures in this embodiment are all connected to the gas in the gas injector. Therefore, the bellows 6 in this embodiment is located above the armature 23, so that when the gas injector is opened, the valve needle 2 only needs to overcome the elastic force of the return spring 21, ensuring that the electromagnetic force required for the valve needle 2 to open under different working gas pressures is consistent.

[0033] The upper end of the guide rod 5 passes through the pressure sleeve 62 and is fitted with the pressure sleeve 62 with a small clearance, allowing the guide rod 5 to slide downward relative to the pressure sleeve 62 under the action of gravity. The pressure sleeve 62 is interference-fitted with the damping valve body 4 to seal the damping chamber 41. The upper end of the guide rod 5 extends into the damping chamber 41, and when the coil 3 is de-energized, the top of the guide rod 5 in this embodiment is higher than the top of the pressure sleeve 62.

[0034] The vertical cross-section of the plunger 8 is inverted T-shaped, and a step is formed at the bottom of the plunger 8. The first elastic element 84 and the second elastic element 83 are both springs. The second elastic element 83 is sleeved on the plunger 8 and the lower end of the second elastic element 83 abuts against the step. The upper end of the second elastic element 83 abuts against the damping valve body 4, which is used to make the plunger 8 abut against the top of the conductive rod. A gap is formed between the plunger 8 and the pressure sleeve 62, and the maximum stroke of the guide rod 5 is greater than the maximum stroke of the plunger 8.

[0035] The top of the damping valve body 4 is provided with an oil inlet channel 42. The lower part of the oil inlet channel 42 is provided with a first conical surface whose upper diameter is smaller than its lower diameter. The upper part of the cone valve 9 is a second conical surface whose upper diameter is smaller than its lower diameter. The cone valve 9 is located inside the oil inlet channel 42 and is in clearance fit with the oil inlet channel 42, so that the cone valve 9 can slide downward along the oil inlet channel 42. The cone valve 9 is provided with a central damping hole 91 for connecting the upper part of the oil inlet channel 42 with the damping chamber 41. The top of the plunger 8 is provided with a groove 81. The lower end of the first elastic member 84 is located inside the groove 81 and abuts against the bottom of the groove 81. The top of the second elastic member 83 abuts against the cone valve 9, so that the second conical surface abuts against the first conical surface, thereby sealing the oil inlet channel 42. In this embodiment, the bottom of the groove 81 is also provided with a connecting hole 82 for connecting the damping chamber 41 with the gap below the plunger 8.

[0036] The oil injection body 7 has a downward-facing cavity. The top of the damping valve body 4 is located inside the cavity and is press-fitted with the oil injection body 7. An oil injection chamber 71 is formed between the damping valve body 4 and the top of the oil injection body 7. The upper end of the oil inlet channel 42 communicates with the oil injection chamber 71. The top of the oil injection chamber 71 is provided with an oil inlet 72, and a sealing element 73 is clamped in the oil inlet 72. In this embodiment, the sealing element 73 is a steel ball. The damping oil can be injected into the oil injection chamber 71 more quickly and conveniently through the oil inlet 72.

[0037] The specific implementation process is as follows: When coil 3 is energized, valve needle 2 slides downward, mounting base 61 loses the support of valve needle 2 and slides downward, guide rod 5 slides downward accordingly, plunger 8 slides downward under the elastic force of second elastic element 83, first spring extends, and the elastic force of first spring on cone valve 9 is insufficient to support cone valve 9, so that second conical surface no longer abuts against first conical surface, cone valve 9 opens oil inlet channel 42, and damping oil in oil injection chamber 71 simultaneously enters damping chamber 41 from the gap between cone valve 9 and oil inlet channel 42 and the central damping hole 91. During this process, the distance that guide rod 5 slides downward is greater than the distance that plunger 8 slides downward, so there is a gap between guide rod 5 and plunger 8 at this time.

[0038] When the power is off, the guide rod 5 returns to its original position upward along with the valve needle 2. The position L1 is defined as when the guide rod 5 contacts the plunger 8, and the position L2 is defined as when the second conical surface abuts against the first conical surface. The reset of the guide rod 5 and the valve needle 2 includes three processes: First process: Start of reset → L1. Since there is a gap between the guide rod 5 and the plunger 8, the guide rod 5 will not push the plunger 8 to slide at this time. Therefore, the first stage of the valve needle 2's reset will not be damped, and the valve needle 2 can respond quickly.

[0039] The second process: L1→L2, the guide rod 5 contacts the plunger 8 and begins to push the plunger 8 upward, reducing the space of the damping chamber 41. Simultaneously, the damping oil in the damping chamber 41 enters the oil filling chamber 71 from the gap between the cone valve 9 and the oil inlet channel 42, as well as the central damping hole 91. At this time, the damping oil provides a relatively weak damping effect to the valve needle 2. At position L2, the first conical surface abuts against the second conical surface, and the gap between the cone valve 9 and the oil inlet channel 42 is closed.

[0040] Third process: L2 → Guide rod 5 and valve needle 2 are fully reset, gas injector is fully closed. At this time, the damping oil in damping chamber 41 enters oil injection chamber 71 only from the central damping hole 91. At this time, the damping oil provides greater damping effect for valve needle 2, so that valve needle 2 decelerates quickly, thereby better buffering valve needle 2.

[0041] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A gas injector with hydraulic damping, comprising a solenoid valve unit, a valve unit, and a reset spring, wherein the solenoid valve unit includes an armature, and the valve unit includes a valve needle, characterized in that: A damping unit is provided on the side of the armature away from the valve needle. The damping unit includes a damping valve body, a plunger, a cone valve, and a first elastic element. The damping valve body has an inner cavity. One end of the plunger is located in the inner cavity and slides and seals with the damping valve body. A damping chamber is formed between the plunger and the damping valve body. The plunger can slide with the valve needle. The damping valve body has an oil inlet channel opposite to the plunger and communicating with the damping chamber. The cone valve is opposite to the oil inlet channel and can open and close the oil inlet channel. The cone valve has a central damping hole. The first elastic element is connected to the cone valve and is used to close the oil inlet channel.

2. A gas injector with hydraulic damping according to claim 1, characterized in that: The oil inlet channel has a first conical surface at one end near the damping chamber, and the cone valve has a second conical surface that is opposite to and abuts against the first conical surface.

3. A gas injector with hydraulic damping according to claim 2, characterized in that: The plunger has a groove, and the end of the first elastic element away from the cone valve is located in the groove and abuts against the side wall of the groove.

4. A gas injector with hydraulic damping according to claim 1, characterized in that: A guide rod is provided on the side of the plunger away from the cone valve. One end of the guide rod is opposite to the valve needle, and the other end can push the plunger to slide closer to the cone valve.

5. A gas injector with hydraulic damping according to claim 4, characterized in that: The travel of the guide rod is greater than the travel of the plunger.

6. A gas injector with hydraulic damping according to claim 1, characterized in that: The damping unit also includes a second elastic element, one end of which abuts against the plunger and is used to slide the plunger toward the side closer to the valve needle when the valve needle moves away from the plunger.

7. A gas injector with hydraulic damping according to claim 1, characterized in that: The damping unit also includes an oil injection body, which has a cavity. One end of the damping valve body is located in the cavity and is slidably sealed with the oil injection body. An oil injection chamber is formed between the damping valve body and the oil injection body, and the oil inlet channel is connected to the oil injection chamber.

8. A gas injector with hydraulic damping according to claim 7, characterized in that: The side wall of the oil filling chamber is provided with an oil inlet, and the oil inlet is provided with a seal for sealing the oil inlet.

9. A gas injector with hydraulic damping according to claim 4, characterized in that: A flexible sealing unit is provided between the armature and the damping valve body. The flexible sealing unit includes a flexible sleeve, which is fitted onto the guide rod. The inner side of the flexible sleeve forms a sealing space that is only connected to the damping chamber.

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