Control valve structure and dual-fuel injector assembly

Abstract

The invention belongs to the technical field of ejectors, and particularly discloses a control valve structure which comprises an ejector body provided with a control cavity. The valve seat assembly is arranged in the ejector body and comprises a valve seat and an armature, the valve seat is provided with a valve seat hole, and the armature slides along the valve seat hole; the valve seat is provided with an oil containing groove communicated with the valve seat hole, fuel enters the control cavity through the oil containing groove, a conical surface structure is arranged between the oil containing groove and the control cavity, and the valve seat is provided with a first groove communicated with the oil containing groove. The metering valve is arranged below the valve seat and provided with a first oil channel, along with lifting or falling of the armature, the conical surface structure closes or opens a circulation channel of the oil containing groove and the control cavity, and meanwhile the armature opens or closes the circulation channel of the first oil channel and the control cavity. According to the control valve structure, fuel oil rapidly flows out of the control cavity, and therefore the opening time of the needle valve is shortened. The invention further discloses a dual fuel injector assembly.

Description

Technical Field

[0001] The invention belongs to the technical field of injectors, and in particular relates to a control valve structure and a dual-fuel injector assembly. Background Art

[0002] The main function of the fuel injector is to inject fuel into the combustion chamber to control the combustion process. How to complete the fuel injection action in a very short time is the goal that industry insiders have been striving for.

[0003] Our company submitted a Chinese invention patent in 2020, publication number CN111535964B, a common rail injector with a fast switching function. When injecting fuel, the solenoid control valve is energized, and the armature is sucked upward by the solenoid control valve, so that the armature shaft is lifted upward, the upper part of the steel ball loses support, and the high-pressure fuel in the oil metering hole pushes up the steel ball, the oil metering hole opens, and the fuel leaks out through the oil metering hole. Since the amount of fuel leaked from the oil metering hole is greater than the amount of fuel entering from the oil inlet metering hole and the oil inlet regulating hole, the fuel pressure inside the control valve sleeve increases rapidly. As the speed decreases, the needle valve is lifted up by the high-pressure fuel at the bottom and the nozzle opens. During this process, as the needle valve moves upward, the lower section of the guide area will gradually block the oil inlet regulating hole until the oil inlet regulating hole is completely closed, causing the amount of fuel entering the control valve sleeve to gradually decrease. This further increases the difference between the amount of fuel flowing out of the oil metering hole and the amount of fuel entering the control valve sleeve. Correspondingly, the fuel pressure difference between the upper and lower ends of the needle valve will also increase further, allowing the needle valve to move upward quickly, allowing the nozzle to quickly reach the maximum opening state, and a large amount of fuel is quickly sprayed out and participates in combustion.

[0004] During use, it was found that the following problems still exist: when the solenoid valve is energized for fuel injection, the amount of fuel entering the control valve sleeve gradually decreases, fuel still enters the control chamber, the pressure in the control chamber drops slowly, and the needle valve is open for a long time, which is not conducive to improving the response performance. Summary of the invention

[0005] The object of the present invention is to provide a control valve structure, in which the amount of fuel flows out of the control chamber quickly, thereby reducing the opening time of the needle valve.

[0006] The objective of the present invention is achieved through such a technical solution, which specifically provides a control valve structure, including:

[0007] The ejector body is provided with a control chamber;

[0008] The valve seat assembly is arranged in the injector body, and includes a valve seat and an armature. The valve seat is provided with a valve seat hole. The valve seat is provided with an oil storage groove connected with the valve seat hole. The fuel enters the control chamber through the oil storage groove. A conical surface structure is provided between the oil storage groove and the control chamber. The valve seat is provided with a first groove connected with the oil storage groove.

[0009] The metering valve is arranged under the valve seat and has a first oil passage.

[0010] As the armature is lifted or dropped along the valve seat hole, the conical surface structure closes or opens the flow passage between the oil storage tank and the control chamber, and at the same time the armature opens or closes the flow passage between the first oil passage and the control chamber.

[0011] Preferably, the conical surface structure includes a conical surface arranged on the armature and a seat surface arranged on the valve seat and matched with the conical surface, and an angle is preset between the seat surface and the conical surface.

[0012] Preferably, the angle is 0.5°.

[0013] Preferably, the injector body is provided with an oil return passage, and the first groove is communicated with the oil return passage.

[0014] Preferably, a buffer groove is provided in the flow channel between the oil storage groove and the control chamber.

[0015] Preferably, a first metering hole and a second metering hole are provided on the end surface of the metering valve, the first metering hole is communicated with the control chamber and the buffer groove, and the second metering hole is communicated with the first oil passage.

[0016] Preferably, a second oil passage is provided in the first metering hole and the control chamber, and the diameter of the second oil passage is greater than the diameter of the first metering hole.

[0017] Preferably, a second groove is provided on the lower end surface of the armature.

[0018] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0019] The control valve structure of the present invention is provided with a conical surface structure, which dynamically closes or opens the flow channel of fuel from the oil tank to the control chamber as the armature is lifted or dropped. At the same time, as the armature is lifted or dropped, the armature dynamically opens or closes the flow channel from the control chamber to the first oil channel. When the armature is lifted, the high-pressure fuel no longer enters the control chamber due to the conical surface structure, which can rapidly reduce the pressure in the control chamber, shorten the opening time of the needle valve, and improve the response performance of the injector. The armature is immersed in the oil tank, and the valve seat is provided with a first groove connected to the oil tank. The fuel in the first groove is lower than the pressure of the oil tank. The fuel flows through the outer surface of the valve seat, and the fuel lubricates the outer surface of the armature. At the same time, the heat generated by the sliding of the armature in the valve seat hole is taken away by the flowing fuel, which has a cooling effect.

[0020] Another object of the present invention is to provide a dual-fuel injector assembly that can be provided with a fuel control valve and a gas control valve according to the application scenario, so as to spray fuel or gas.

[0021] The objective of the present invention is achieved through such a technical solution, specifically providing a dual-fuel injector assembly, including a control valve structure, the control valve structure is provided with two groups, namely a fuel control valve and a gas control valve, and also includes a solenoid valve assembly and a needle valve assembly.

[0022] Preferably, the metering valve of the fuel control valve and the metering valve of the gas control valve are formed integrally.

[0023] Due to the adoption of the above technical solution, the present invention has the following advantages: the injector can inject fuel or gas, improve the application scenario, and can quickly start the injection time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation of the present invention, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0025] Figure 1 It is a structural schematic diagram of a control valve structure of the present invention;

[0026] Figure 2 It is a structural schematic diagram of the valve seat assembly;

[0027] Figure 3 It is a magnified schematic diagram of the cone structure (magnified at point A);

[0028] Figure 4 is a schematic diagram of the injector body;

[0029] Figure 5 It is a schematic diagram of the structure of the dual fuel injector assembly.

[0030] Reference numerals:

[0031] 1- injector body, 11- control chamber, 12- oil return channel,

[0032] 2-valve seat assembly, 21-valve seat, 211-valve seat hole, 212-oil storage groove, 213-buffer groove, 214-first groove, 22-armature, 221-second groove, 23-fuel enters the oil passage,

[0033] 3-metering valve, 31-first oil passage, 32-second metering hole, 33-first metering hole, 34-second oil passage,

[0034] 4-conical surface structure, 41-conical surface, 42-seat surface,

[0035] 5-Fuel control valve, 6-Gas control valve,

[0036] 7-solenoid valve assembly, 71-solenoid valve seat, 72-solenoid valve spring,

[0037] 8-needle valve assembly, 81-needle valve seat, 82-needle valve body, 83-needle valve spring. DETAILED DESCRIPTION

[0038] See also Figure 1 , Figure 2 and Figure 4 , a control valve structure, including: an injector body 1, a valve seat assembly 2 and a metering valve 3.

[0039] The injector body 1 is provided with a control chamber 11; the valve seat assembly 2 is arranged in the injector body 1, including a valve seat 21 and an armature 22, the valve seat 21 is provided with a valve seat hole 211, and the armature 22 slides along the valve seat hole 211; the valve seat 21 is provided with an oil receiving groove 212 connected with the valve seat hole 211, and the fuel enters the control chamber 11 through the oil receiving groove 212, and a conical structure 4 is provided between the oil receiving groove 212 and the control chamber 11, and the valve seat 21 is provided with a first groove 214 connected with the oil receiving groove 212; the metering valve 3 is arranged under the valve seat 21, and the metering valve 3 is provided with a first oil channel 31, and as the armature 22 is lifted or dropped, the conical structure 4 closes or opens the flow channel between the oil receiving groove 212 and the control chamber 11, and at the same time, the armature 22 opens or closes the flow channel between the first oil channel 31 and the control chamber 11. Specifically, the valve seat 21 is provided with a fuel inlet passage 23, and the fuel enters the fuel inlet passage 23 at high pressure, and the fuel enters the oil storage tank 212 through the fuel inlet passage 23, and then enters the control chamber 11. When the armature 22 is lifted, the conical surface structure 4 closes the flow channel between the oil storage tank 212 and the control chamber 11, and the fuel in the oil storage tank 212 cannot enter the control chamber 11. In addition, since the armature 22 is lifted, the end face of the armature 22 is separated from the end face of the metering valve 3, and the first oil passage 31 is connected with the control chamber 11. The fuel in the control chamber 11 flows outward through the first oil passage 31. At this time, the needle valve overcomes the pressure of the control chamber 11, the needle valve is lifted, and the fuel injection starts. When the armature 22 is seated, the end face of the armature 22 is close to the end face of the metering valve 3, and the first oil channel 31 is closed to the control chamber 11. At this time, the conical structure 4 opens the flow channel between the oil storage tank 212 and the control chamber 11, and there is a flow gap. The fuel enters the control chamber 11 through the oil storage tank 212, and the pressure difference between the control chamber 11 and the needle valve is reduced, and the needle valve falls, and the fuel injection stops. When the armature 22 is lifted, the high-pressure fuel no longer enters the control chamber 11 due to the conical structure 4, which can rapidly reduce the pressure in the control chamber 11, shorten the needle valve opening time, and improve the injector response performance. In the prior art, the armature seals the control chamber, and the control chamber is a high-pressure chamber. The armature is subjected to upward liquid pressure and downward spring force, and because F=PS, the higher the fuel pressure, the greater the liquid pressure on the armature, and the higher the spring force required, so that the fuel can be sealed. The higher the spring force, the greater the electromagnetic force required, because the armature can only be lifted when the electromagnetic force overcomes the spring force. The armature 22 seals the first oil channel 31 of the low-pressure oil channel, so the spring force for sealing the low-pressure oil is smaller than that for sealing the high-pressure oil, and the required electromagnetic force is small. The electromagnetic force is positively correlated with the size of the solenoid valve assembly, which plays an important role in the miniaturization of the solenoid valve and facilitates the miniaturization of the injector.

[0040] See also Figure 2 and Figure 3Furthermore, the conical surface structure 4 includes a conical surface 41 provided on the armature 22 and a seat surface 42 provided on the valve seat 21 and matched with the conical surface 41 , and an angle is preset between the seat surface 42 and the conical surface 41 . Specifically, the cone surface angle of the armature 22 is smaller than the seat surface angle on the valve seat 21, the angle α of the cone surface of the entire armature 22 is 89°, the angle β of the seat surface of the entire valve seat 21 is 90°, and the preset angle is 0.5°. If the preset angle is greater than 0.5°, the sliding length of the seat surface 42 and the cone surface 41 is relatively long. If the preset angle is less than 0.5°, the flow gap is relatively small, balancing the flow rate and sliding length of the fuel. The preset angle is 0.5°, which can quickly improve the response performance of the injector. When the armature 22 moves upward, the seat surface 42 and the cone surface 41 form a line seal at the port. At this time, the high-pressure fuel at the oil tank 212 cannot enter the control chamber 11, and the high-pressure fuel in the control chamber 11 flows out through the low-pressure first oil channel 31. The pressure in the control chamber 11 decreases, the needle valve lifts upward, and then the fuel begins to be injected. The conical structure 4 dynamically closes or opens the flow channel as the armature 22 moves, and plays a role in controlling whether the high-pressure fuel in the oil tank 212 can enter the control chamber 11, thereby improving the injector response performance.

[0041] See also Figure 1 , Figure 2 and Figure 5 Furthermore, the injector body 1 is provided with an oil return passage 12, and the first groove 214 is connected to the oil return passage 12. Specifically, the oil return passage 12 is a low-pressure oil passage, and the armature 22 and the upper end surface of the valve seat hole 211 are matched with a small gap. The armature 22 slides up and down in the valve seat hole 211, and the small gap fit has a guiding effect on the sliding of the armature 22. The oil storage groove 212 is a high-pressure groove, and part of the fuel entering from the fuel inlet oil passage 23 flows from the oil storage groove 212 into the first groove 214 through the gap, and then flows out from the oil return passage 12. The fuel flows on the outside of the armature 22. During the flow, the fuel takes away the heat generated by friction during the sliding of the armature 22 in the valve seat hole 211, and has a cooling effect on the rapidly moving armature. At the same time, it has a lubricating effect on the lifting or falling movement of the armature 22, reducing the wear of the armature 22 and the valve seat hole 211.

[0042] See also Figure 1 and Figure 2 Furthermore, a buffer groove 213 is provided in the flow channel between the oil storage groove 212 and the control chamber 11. The buffer groove 213 is provided to buffer the flow stress of the high-pressure fuel and delay the fatigue damage of the high-pressure fuel to the flow channel.

[0043] See also Figure 1 and Figure 2Furthermore, a first metering hole 33 and a second metering hole 32 are provided on the end surface of the metering valve 3. The first metering hole 33 is connected to the control chamber 11 and the buffer groove 213, and the second metering hole 32 is connected to the first oil passage 31. Specifically, one end of the first metering hole 33 is connected to the control chamber 11, and the other end is connected to the buffer groove 213. The first metering hole 33 and the second metering hole 32 are parallel to each other. When the armature 22 is lifted, the first metering hole 31 and the second metering hole 32 are connected, and the fuel in the control chamber 11 flows outward through the first metering hole 33, the second metering hole 32, and the first oil passage 31. When the armature 22 falls, the second oil passage 32 is closed from being connected to the control chamber 11.

[0044] See also Figure 1 and Figure 2 Furthermore, a second oil passage 34 is provided in the first metering hole 33 and the control chamber 11, and the diameter of the second oil passage 34 is larger than the diameter of the first metering hole 33. With this structure, when the high-pressure fuel enters the control chamber 11 from the first metering hole 33 or flows from the control chamber 11 to the second metering hole 32, the second oil passage 34 has a buffering effect on the flow stress of the high-pressure fuel, delays the fatigue damage of the high-pressure fuel to the metering valve 3, and improves the service life of the metering valve 3.

[0045] See also Figure 1 and Figure 2 Furthermore, the lower end surface of the armature 22 is provided with a second groove 221. The second groove 221 can reduce the contact area between the lower end surface of the armature 22 and the metering valve 3. When the armature 22 is fixed by pressure, reducing the area can increase the pressure per unit area, that is, the pressure of the armature 22 on the metering valve 3 is increased, the sealing effect is good, and the fuel is not easy to leak. Preferably, the second groove 221 is arranged just above the second metering hole 32. When the armature 22 is lifted, the fuel in the control chamber 11 flows to the second metering hole 32. The second groove 221 has a buffering effect on the fuel flow stress from the control chamber 11, delays the fatigue damage of the high-pressure fuel to the metering valve 3, and improves the service life of the metering valve 3.

[0046] See also Figure 4 and Figure 5A dual fuel injector assembly includes a control valve structure, which is provided with two groups, namely a fuel control valve 5 and a gas control valve 6, and also includes a solenoid valve assembly 7 and a needle valve assembly 8. Specifically, the solenoid valve assembly 7 is provided with two groups, which respectively control the fuel control valve 5 and the gas control valve 6. The solenoid valve assembly 7 includes a solenoid valve seat 71 and a solenoid valve spring 72. The solenoid valve seat 71 is arranged in the injector body 1, and the solenoid valve spring 72 is arranged in the solenoid valve seat 71. One end of the solenoid valve spring 72 abuts against the solenoid valve seat 71, and the other end is crimped with the valve seat assembly 2. The needle valve assembly 8 includes a needle valve seat 81, a needle valve body 82 and a needle valve spring 83. The needle valve seat 81 is arranged in the injector body 1, and the needle valve body 82 and the needle valve spring 83 are both arranged in the needle valve seat 81. One end of the needle valve spring 83 abuts against the outer surface of the control chamber, and the other end abuts against the needle valve body 82.

[0047] The basic working principle of the dual fuel injector assembly of the present invention is similar to that of the prior art. The working principle is explained by taking the fuel injection control principle as an example: a part of the high-pressure fuel enters the oil storage tank 212 through the fuel inlet oil passage 23, and then enters the control chamber 11 through the buffer groove 213, the first metering hole 33, and the second oil passage 34. When the solenoid valve seat 71 is energized, the armature 22 is lifted up to overcome the pressure of the solenoid valve spring 72, and the two conical surfaces of the conical surface structure 4 have an angle deviation, and are line-sealed after contact, so that the fuel in the oil storage tank 212 cannot enter the control chamber 11, and because the armature 22 is lifted up, the first oil passage 31 is connected with the control chamber 11, and the fuel in the control chamber 11 flows outward through the second oil passage 34, the first metering hole 33, the second metering hole 32, and the first oil passage 31. At this time, the pressure difference of the control chamber 11 on the needle valve body 82 overcomes the elastic force of the needle valve spring 83, and the needle valve body 82 is lifted up to start fuel injection. When the electromagnetic valve seat 71 is powered off, the armature 22 falls, the first oil passage 31 and the control chamber 11 are closed, and at this time there is a flow gap in the conical structure 4, the fuel enters the control chamber 11, the pressure difference between the control chamber 11 and the needle valve body 82 decreases, the spring force of the needle valve spring 83 overcomes the liquid pressure of the control chamber 11, the needle valve body 82 falls, and the fuel injection stops. Similarly, the gas injection control principle is the same.

[0048] See also Figure 1 Furthermore, the metering valve of the fuel control valve 5 and the metering valve of the gas control valve 6 are integrally formed, which is convenient for processing and manufacturing and saves costs.

[0049] The control valve structure and dual-fuel injector assembly of the present invention are provided with a conical surface structure 4 in the control valve structure, and the flow channel of the fuel from the oil tank 212 to the control chamber 11 is dynamically closed or opened as the armature 22 is lifted or dropped. At the same time, the flow channel from the control chamber 11 to the first oil channel 31 is dynamically opened or closed as the armature 22 is lifted or dropped. When the armature 22 is lifted, the high-pressure fuel no longer enters the control chamber 11 due to the conical surface structure 4, which can rapidly reduce the pressure in the control chamber 11, shorten the needle valve opening time, and improve the injector response performance. The second oil channel, the second groove 221 and the buffer groove 213 are provided, which have a buffering effect on the flow stress of the high-pressure fuel, delay the fatigue damage of the high-pressure fuel to the metering valve 3 and the valve seat 21, and improve the service life of the injector. The first groove 214 connected to the oil return channel 12 is provided on the upper end surface of the valve seat hole 211, which also has the effect of cooling, guiding and lubricating the fast-moving armature 22. The armature 22 seals the first oil passage 31 of the bottom pressure oil passage, and requires a small electromagnetic force, which plays an important role in the miniaturization of the electromagnetic valve and facilitates the miniaturization of the injector.

[0050] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the scope of the present invention should be included in the protection scope of the present invention.

Claims

1. A control valve structure, characterized in that: include: The injector body (1) is provided with a control chamber (11); A valve seat assembly (2) is arranged in the injector body (1), comprising a valve seat (21) and an armature (22); the valve seat (21) is provided with a valve seat hole (211); the valve seat (21) is provided with an oil storage groove (212) connected to the valve seat hole (211); fuel enters the control chamber (11) through the oil storage groove (212); a conical surface structure (4) is provided between the oil storage groove (212) and the control chamber (11); and the valve seat (21) is provided with a first groove (214) connected to the oil storage groove (212); The metering valve (3) is arranged under the valve seat (21) and is provided with a first oil passage (31); As the armature (22) is lifted or dropped along the valve seat hole (211), the conical structure (4) closes or opens the flow passage between the oil storage tank (212) and the control chamber (11), and at the same time, the armature (22) opens or closes the flow passage between the first oil passage (31) and the control chamber (11).

2. The control valve structure according to claim 1, characterized in that: The conical surface structure (4) comprises a conical surface (41) arranged on the armature (22) and a seat surface (42) arranged on the valve seat (21) and matching with the conical surface (41); the seat surface (42) and the conical surface (41) are preset at an angle.

3. The control valve structure according to claim 2, characterized in that: The angle is 0.5°.

4. The control valve structure according to claim 1, 2 or 3, characterized in that: The injector body (1) is provided with an oil return passage (12), and the first groove (214) is in communication with the oil return passage (12).

5. The control valve structure according to claim 1.2 or 3, characterized in that: A buffer groove (213) is provided in the flow channel between the oil storage groove (212) and the control chamber (11).

6. The control valve structure according to claim 5, characterized in that: A first metering hole (33) and a second metering hole (32) are provided on the end surface of the metering valve (3); the first metering hole (33) is communicated with the control chamber (11) and the buffer groove (213); and the second metering hole (32) is communicated with the first oil passage (31).

7. The control valve structure according to claim 6, characterized in that: A second oil passage (34) is provided in the first metering hole (33) and the control chamber (11); the diameter of the second oil passage (34) is greater than the diameter of the first metering hole (33).

8. The control valve structure according to claim 1.2.3, 6 or 7, characterized in that: The lower end surface of the armature (22) is provided with a second groove (221).

9. A dual fuel injector assembly, characterized in that: The invention comprises a control valve structure as claimed in any one of claims 1 to 8, wherein the control valve structure is provided with two groups, namely a fuel control valve (5) and a gas control valve (6), and further comprises a solenoid valve assembly (7) and a needle valve assembly (8).

10. The dual fuel injector assembly according to claim 9, characterized in that: The metering valve of the fuel control valve (5) and the metering valve of the gas control valve (6) are integrally formed.

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