CN114135430A

CN114135430A - Fuel injection valve

Info

Publication number: CN114135430A
Application number: CN202111512314.6A
Authority: CN
Inventors: 胡凯耀; 周庭波; 顾小磊; 常青; 陈楠; 董森
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2021-12-08
Filing date: 2021-12-08
Publication date: 2022-03-04
Anticipated expiration: 2041-12-08
Also published as: CN114135430B

Abstract

The invention belongs to the technical field of engine fuel injection, and discloses a fuel injection valve which comprises an injection valve body, a valve sleeve, a needle valve body assembly, a long needle valve and a coupling sleeve assembly. The injection valve body is provided with a high-pressure cavity for containing fuel; the valve housing has a first receiving chamber; the needle valve body assembly is provided with a second accommodating cavity and a spray hole; the long needle valve is slidably arranged in the first accommodating cavity and the second accommodating cavity and can periodically open or close the spray hole; the coupling sleeve assembly is slidably sleeved on the long needle valve, an overflowing gap is formed between the coupling sleeve assembly and the injection valve body, one end of the overflowing gap is communicated with the high-pressure cavity, the other end of the overflowing gap is provided with a nozzle pressure accumulation cavity used for being communicated with the spray hole, and the overflowing gap is configured to adjust the pressure difference between the high-pressure cavity and the nozzle pressure accumulation cavity. The fuel injection valve can solve the problem that the existing structure of the fuel injection valve cannot give consideration to opening response and closing response, and can improve effective fuel injection pressure; simple structure, the machining precision requires lowly, reduces the processing cost.

Description

Fuel injection valve

Technical Field

The invention relates to the technical field of engine fuel injection, in particular to a fuel injection valve.

Background

With the continuous upgrading of emission regulations, the market has higher and higher requirements on the emission reduction of diesel engines, which puts higher requirements on fuel supply systems of the diesel engines, and requires the diesel engines to have more accurate injection quantity, injection time, injection consistency and higher injection pressure. The common rail fuel injector is used as a common rail system terminal actuator, and the combustion performance in a cylinder of the diesel engine is directly influenced by the performance of the common rail fuel injector, so that the emission of the diesel engine is influenced. In order to reduce the energy consumption of the system, the structural form of the common rail oil injector is developed from static leakage to intermediate oil feeding without static leakage. CN101743494B discloses a typical structure of an extremely high pressure common rail injector without static leakage, which is provided with a certain throttle position on the long needle head, the throttle position generates a stable pressure drop independent of the fuel reynolds number, so that the throttle effect is independent of the fuel temperature, thereby realizing a constant closing force on the needle to ensure the rapid closing of the needle. CN109681360A discloses a long needle valve for a fuel injection valve, which specifies a throttle range of a throttle section of the long needle valve explicitly, and determines the throttle range to generate a pressure drop range at two ends of the throttle section, thereby ensuring that fuel can be injected in a stable and controllable range, and improving the response speed of an injector. The two patent applications disclose common structures of the conventional common rail fuel injector, namely, a certain throttle valve position or throttle section is arranged at the head part of a long needle valve, the throttle valve position or throttle section is fixed at a certain position of the needle valve and is integrated with the needle valve, and throttling is carried out through the throttle valve position or throttle section, so that pressure drop is generated at two ends of the throttle valve position or throttle section to ensure that the injection valve can respond quickly. However, in the above scheme, the throttle valve position or the throttle section has a certain throttle amount in the operation process of the injection valve, if the throttle is too small, the opening response of the injection valve is fast, but the closing response is slow; if the throttling is too large, the closing response of the injection valve is fast, the opening response is slow, and the opening response and the closing response can not be compatible. In addition, in the scheme, due to the existence of the throttle valve position or the throttle section, the throttling effect can be generated in the injection process of the injection valve, so that the actual injection pressure of the needle valve head is much lower than the working pressure of a fuel system. In addition, the throttle valve position or the throttle section in the above scheme is generally a flat structure and has a guide section, the needle valve structure is complex, the requirement on the processing precision is high, and the processing cost is high.

Disclosure of Invention

The invention aims to provide a fuel injection valve, which can solve the problem that the existing structure of the fuel injection valve can not give consideration to opening response and closing response and can improve effective fuel injection pressure; simple structure, the machining precision requires lowly, reduces the processing cost.

In order to achieve the purpose, the invention adopts the following technical scheme:

a fuel injection valve comprising:

an injection valve body having a high pressure chamber for containing fuel;

the valve sleeve is connected to the injection valve body and blocks one end of the high-pressure cavity, and the valve sleeve is provided with a first accommodating cavity;

the needle valve body assembly is detachably connected to one end of the injection valve body and seals the other end of the high-pressure cavity, the needle valve body assembly is provided with a second accommodating cavity, and one end, far away from the valve sleeve, of the needle valve body assembly is provided with at least one spray hole;

the long needle valve is slidably mounted in the first accommodating cavity and the second accommodating cavity, a control cavity is formed between the long needle valve and the valve sleeve, the control cavity is communicated with the high-pressure cavity, the long needle valve is of an integrated structure, and the long needle valve can periodically open or block the spray hole; and

the coupling cover subassembly, the coupling cover subassembly slip cap is located on the long needle valve, the coupling cover subassembly with it overflows the clearance to have between the injection valve body, it communicates to overflow clearance one end high-pressure chamber, the other end are provided with and are used for the intercommunication the glib talker of orifice holds the pressure chamber, it is configured to adjust to overflow the clearance high-pressure chamber with pressure differential between the glib talker holds the pressure chamber.

As a preferable structure of the present invention, the long needle valve includes a first adjusting section, a connecting section, and a second adjusting section, which are connected in sequence, the first adjusting section is slidably connected in the first accommodating cavity, the second adjusting section is slidably connected in the second accommodating cavity, two ends of the connecting section respectively have a first step surface and a second step surface, and the coupling sleeve assembly is slidably sleeved on the second adjusting section and can abut against the second step surface.

As a preferred structure of the present invention, the coupling sleeve assembly includes:

the coupling sleeve is slidably sleeved outside the second adjusting section;

coupling sleeve pressure regulating spring, coupling sleeve pressure regulating spring set up in glib pressure accumulation intracavity, coupling sleeve pressure regulating spring's one end is connected the coupling sleeve, the other end is connected needle valve body subassembly, coupling sleeve pressure regulating spring be used for to first pretightning force is applyed with the butt to the coupling sleeve the second step face.

As a preferred structure of the present invention, the needle valve body assembly includes:

the needle valve body is provided with at least one spray hole at one end, the other end of the needle valve body is connected with the injection valve body, and the second accommodating cavity is formed in the needle valve body;

the tight cap of glib talker, the tight cap cover of glib talker is located on the needle valve body to can dismantle connect in the injection valve body.

As a preferred structure of the present invention, one end of the needle valve body connected to the injection valve body is provided with a needle valve body sealing surface, one end of the coupling sleeve is provided with a coupling sleeve sealing surface, and the coupling sleeve sealing surface can be attached to the needle valve body sealing surface and seal the oil nozzle pressure accumulation cavity.

As a preferred structure of the present invention, the coupling sleeve assembly further includes a coupling sleeve lift adjusting gasket, one end of the coupling sleeve lift adjusting gasket can abut against the second step surface, and the other end can abut against one end of the coupling sleeve far away from the coupling sleeve pressure regulating spring.

As a preferred structure of the invention, the fuel injection valve further comprises a long needle valve pre-tightening spring, the long needle valve pre-tightening spring is sleeved outside the first adjusting section, one end of the long needle valve pre-tightening spring is connected with the valve sleeve, the other end of the long needle valve pre-tightening spring is connected with the long needle valve, and the long needle valve pre-tightening spring is used for applying a second pre-tightening force to the long needle valve to plug the spray hole.

As a preferred structure of the present invention, the fuel injection valve further includes a long needle valve adjusting shim, the long needle valve adjusting shim is sleeved outside the first adjusting section, one end of the long needle valve adjusting shim is connected to the long needle valve pre-tightening spring, and the other end of the long needle valve adjusting shim abuts against the first step surface.

As a preferable structure of the present invention, the injection valve body is provided with an injection valve fuel inlet port that communicates with the high pressure chamber.

In a preferred configuration of the present invention, the valve housing further has an oil outlet orifice, and the control chamber communicates with an external pressure relief chamber through the oil outlet orifice.

As a preferable structure of the invention, the oil-saving valve further comprises a control valve assembly, wherein the control valve assembly comprises an electromagnet, a valve seat and a ball valve, the valve seat is abutted against the valve sleeve, the ball valve is arranged between the valve seat and the valve sleeve, and the electromagnet can control the ball valve to periodically block the oil outlet orifice.

As a preferable structure of the invention, the long needle valve is matched with the coupling sleeve by adopting a coupling piece.

As a preferable structure of the invention, the long needle valve is matched with the valve sleeve by adopting a matching part.

The invention has the beneficial effects that: the fuel injection valve provided by the invention adopts a static leakage-free structure, and the coupling sleeve assembly slides up and down along with the change of the pressure difference between the high-pressure cavity and the nozzle pressure accumulation cavity, so that the pressure in the nozzle pressure accumulation cavity is changed, and the opening response and the closing response of the fuel injection valve are improved: when the long needle valve is opened, the coupling sleeve assembly slides downwards so as to increase the pressure of the orifice end and improve the opening response speed; when the long needle valve is closed, the coupling sleeve assembly slides upwards to reduce the pressure of the injection hole end, improve the closing response speed and solve the problem that the existing structure of the fuel injection valve cannot give consideration to both opening response and closing response; the coupling sleeve assembly is always in a sliding state in the working process of the fuel injection valve, the volume of the oil nozzle pressure accumulation cavity can be compressed to compensate for pressure drop caused by oil injection, the pressure of the pressure in the oil nozzle pressure accumulation cavity is kept unchanged in the injection process, and the effective oil injection pressure is improved; the long needle valve of integral type structure simple structure need not adopt flat position structure, reduces machining precision and processing cost.

Drawings

Fig. 1 is a schematic structural view of a fuel injection valve provided in an embodiment of the invention;

FIG. 2 is an enlarged schematic view of a portion A in FIG. 1 according to an embodiment of the present invention;

fig. 3 is an enlarged schematic view of a structure of a portion B in fig. 1 according to an embodiment of the present invention.

In the figure:

1. an injection valve body; 11. a high pressure chamber; 12. an injection valve fuel inlet; 2. a valve housing; 21. a first accommodating chamber; 22. a control chamber; 23. an oil outlet orifice; 3. a needle valve body assembly; 31. a second accommodating chamber; 32. spraying a hole; 33. a needle valve body; 331. a needle valve body sealing surface; 34. tightening a cap of the oil nozzle; 4. a long needle valve; 41. a first conditioning segment; 42. a connecting section; 421. a first step surface; 422. a second step surface; 43. a second conditioning section; 5. a coupling sleeve assembly; 51. an over-current gap; 52. a nozzle tip pressure accumulation cavity; 53. a coupling sleeve; 531. a coupling sleeve sealing surface; 54. a coupling sleeve pressure regulating spring; 55. a coupling sleeve lift adjusting gasket; 6. a long needle valve pre-tightening spring; 7. a long needle valve adjusting shim; 8. a control valve assembly; 81. an electromagnet; 82. a valve seat; 83. a ball valve; 84. an armature.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

As shown in fig. 1 to 3, the embodiment of the present invention provides a fuel injection valve, which includes an injection valve body 1, a valve housing 2, a needle valve body assembly 3, a long needle valve 4 and a coupling sleeve assembly 5. The injection valve body 1 has a high-pressure chamber 11 for receiving fuel. The valve housing 2 blocks one end of the high pressure chamber 11, and the valve housing 2 has a first receiving chamber 21. The needle valve body assembly 3 is detachably connected to one end of the injection valve body 1 and seals the other end of the high-pressure cavity 11, the needle valve body assembly 3 is provided with a second accommodating cavity 31, one end of the needle valve body assembly 3, which is far away from the valve sleeve 2, is provided with at least one spray hole 32, and the spray hole 32 is used for spraying high-pressure fuel. The long needle valve 4 is slidably mounted in the first accommodating cavity 21 and the second accommodating cavity 31, a control cavity 22 is formed between the long needle valve 4 and the valve sleeve 2, the control cavity 22 is communicated with the high-pressure cavity 11, and the long needle valve 4 is of an integrated structure, so that the response speed of the long needle valve 4 can be improved. The long needle valve 4 can periodically open or close the nozzle holes 32 so that the fuel injection valve is in an open state or a closed state. The coupling sleeve assembly 5 is slidably sleeved on the long needle valve 4, a flow passing gap 51 is formed between the coupling sleeve assembly 5 and the injection valve body 1, one end of the flow passing gap 51 is communicated with the high pressure cavity 11, the other end of the flow passing gap 51 is provided with a nozzle pressure accumulation cavity 52 used for being communicated with the spray hole 32, and the flow passing gap 51 is configured to adjust the pressure difference between the high pressure cavity 11 and the nozzle pressure accumulation cavity 52. It is understood that the flow-passing gap 51 has a flow-passing cross section, the flow-passing gap 51 can generate throttling when the fuel injection valve operates, and the area of the flow-passing cross section needs to be determined according to the fuel injection quantity of the fuel injection valve, and the specific value of the flow-passing cross section is not limited in this embodiment. When the fuel injection valve is in the open state, the long needle valve 4 opens the nozzle hole 32, and high-pressure fuel enters the nozzle pressure accumulation chamber 52 from the high pressure chamber 11 through the transfer clearance 51 and is ejected through the opened nozzle hole 32, thereby supplying fuel to the combustion chamber of the engine.

According to the fuel injection valve of the embodiment of the invention, when the fuel injection valve is opened, the long needle valve 4 slides upwards and opens the spray hole 32, the pressure in the nozzle pressure accumulation cavity 52 is reduced, the balance state of the coupling sleeve assembly 5 is destroyed, and the pressure difference between the high pressure cavity 11 at the upper end of the coupling sleeve assembly 5 and the nozzle pressure accumulation cavity 52 at the lower end of the coupling sleeve assembly 5 enables the coupling sleeve assembly 5 to slide downwards so as to resist the pressure reduction at the end of the spray hole 32 after the long needle valve 4 is opened, and maintain the pressure balance state of the coupling sleeve assembly 5. As the coupling sleeve assembly 5 slides downward, the nozzle tip pressure accumulation chamber 52 is compressed and the pressure rises, so that the pressure difference between the nozzle tip pressure accumulation chamber 52 and the control chamber 22 increases, thereby increasing the opening response speed of the long needle valve 4. Accordingly, when the fuel injection valve is closed, the long needle valve 4 slides downward, the pressure in the nozzle tip pressure accumulation chamber 52 rises, the equilibrium state of the coupling sleeve assembly 5 is broken, and the pressure difference between the high pressure chamber 11 at the upper end of the coupling sleeve assembly 5 and the nozzle tip pressure accumulation chamber 52 at the lower end of the coupling sleeve assembly 5 causes the coupling sleeve assembly 5 to slide upward, thereby reducing the pressure in the nozzle tip pressure accumulation chamber 52, increasing the pressure difference between the control chamber 22 and the nozzle tip pressure accumulation chamber 52, and improving the closing response speed. In the working process of the fuel injection valve, the coupling sleeve assembly 5 is always in a sliding state, namely the volume of fuel sprayed from the spray hole 32 by the fuel injection valve in unit time is equal to the volume of the coupling sleeve assembly 5 moving downwards, namely the volume of the nozzle pressure accumulation cavity 52 which is compressed, so that the pressure drop caused by oil injection is compensated, the pressure of the pressure in the nozzle pressure accumulation cavity 52 in the injection process is kept unchanged, and the effective oil injection pressure is improved.

The fuel injection valve of the embodiment of the invention adopts a static leakage-free structure, and the coupling sleeve component 5 slides up and down along with the change of the pressure difference between the high-pressure cavity 11 and the nozzle tip pressure accumulation cavity 52, so that the pressure in the nozzle tip pressure accumulation cavity 52 is changed, and the opening response and the closing response of the fuel injection valve are improved: when the long needle valve 4 is opened, the coupling sleeve assembly 5 slides downwards so as to increase the pressure at the end of the spray hole 32 and improve the opening response speed; when the long needle valve 4 is closed, the coupling sleeve assembly 5 slides upwards to reduce the pressure at the end of the spray hole 32, so that the closing response speed is improved, and the problem that the existing structure of the fuel injection valve cannot give consideration to opening response and closing response is solved. The long needle valve 4 has a simple structure, does not need to adopt a flat position structure, and reduces the processing precision and the processing cost.

Further, the long needle valve 4 includes the first regulation section 41, linkage segment 42 and the second regulation section 43 that connect gradually, and first regulation section 41 sliding connection holds the chamber 21 in the first, and second regulation section 43 sliding connection holds the chamber 31 in the second, and the both ends of linkage segment 42 have first step face 421 and second step face 422 respectively, and coupling cover subassembly 5 sliding sleeve is located the second and is adjusted section 43 and can be supported second step face 422. It will be appreciated that the second adjustment section 43 defines the sliding travel of the coupling sleeve assembly 5.

Further, the coupling sleeve assembly 5 includes a coupling sleeve 53 and a coupling sleeve pressure regulating spring 54, as shown in fig. 2. The coupling sleeve 53 is sleeved outside the second adjusting section 43. The coupling sleeve pressure regulating spring 54 is arranged in the oil nozzle pressure accumulation cavity 52, one end of the coupling sleeve pressure regulating spring 54 is connected with the coupling sleeve 53, the other end of the coupling sleeve pressure regulating spring is connected with the needle valve body assembly 3, and the coupling sleeve pressure regulating spring 54 is used for applying a first pretightening force to the coupling sleeve 53. The coupling sleeve 53 in the initial state can be pressed against the second step surface 422 through the coupling sleeve pressure regulating spring 54, so that the choke pressure accumulation cavity 52 has the maximum volume and is convenient for accommodating high-pressure fuel entering. When the pressure difference between the high-pressure chamber 11 and the nozzle tip pressure accumulation chamber 52 can overcome the first preload of the coupling sleeve pressure regulating spring 54, the coupling sleeve 53 can slide downward.

Further, the needle valve body assembly 3 includes a needle valve body 33 and a nipple cap 34. One end of the needle valve body 33 is provided with at least one spray hole 32, the other end is connected with the injection valve body 1, and the needle valve body 33 is internally provided with a second accommodating cavity 31. The nozzle tip cap 34 is sleeved on the needle valve body 33 and detachably connected to the injection valve body 1. The needle valve body 33 is convenient to disassemble and assemble through the oil nozzle tightening cap 34, and the structure is more reasonable.

Further, a needle valve body sealing surface 331 is provided at one end of the needle valve body 33 connected to the injection valve body 1, a coupling sleeve sealing surface 531 is provided at one end of the coupling sleeve 53, and the coupling sleeve sealing surface 531 can be attached to the needle valve body sealing surface 331 and block the nozzle pressure accumulation cavity 52. When the coupling sleeve 53 slides downward to the lowermost end, the coupling sleeve sealing surface 531 will abut the needle valve body sealing surface 331 to form a high pressure sealing surface, preventing the fuel in the nozzle pressure accumulation chamber 52 from being ejected through the nozzle hole 32. When the fuel injection valve of the embodiment of the invention has abnormal phenomena such as straight-through or the long needle valve 4 is blocked and can not be normally closed, and the like, so that the injection flow of the injection hole 32 is overlarge, the pressure difference between the upper end and the lower end of the coupling sleeve 53 is overlarge, the coupling sleeve 53 slides to the lowest end, the coupling sleeve sealing surface 531 at the lower end of the coupling sleeve 53 is attached to the needle valve body sealing surface 331 at the upper end of the needle valve body 33 to form high-pressure sealing, the fuel oil circulation is blocked, and the engine is protected. When the coupling sleeve 53 is designed, the volume of the coupling sleeve 53 which can slide downwards is larger than the maximum fuel injection quantity of the fuel injection valve, so that the sealing surface 531 of the coupling sleeve cannot be attached to the sealing surface 331 of the needle valve body to form a high-pressure sealing surface to block fuel circulation when the maximum fuel injection quantity is reached.

Further, the coupling sleeve assembly 5 further includes a coupling sleeve lift adjusting gasket 55, one end of the coupling sleeve lift adjusting gasket 55 can abut against the second step surface 422, the other end can abut against one end of the coupling sleeve 53 far away from the coupling sleeve pressure adjusting spring 54, and the coupling sleeve lift adjusting gasket 55 is configured to adjust a sliding stroke of the coupling sleeve 53. It will be appreciated that the thickness of the coupling sleeve lift adjustment shim 55 will affect the sliding travel of the coupling sleeve 53 and thus the maximum fuel injection amount of the fuel injection valve.

Further, the fuel injection valve further comprises a long needle valve pre-tightening spring 6, the long needle valve pre-tightening spring 6 is sleeved outside the first adjusting section 41, one end of the long needle valve pre-tightening spring 6 is connected with the valve sleeve 2, the other end of the long needle valve pre-tightening spring is connected with the long needle valve 4, and the long needle valve pre-tightening spring 6 is used for applying a second pre-tightening force to the long needle valve 4. Through the second pretightening force of the long needle valve pretightening spring 6, the long needle valve 4 in the initial state can be tightly abutted against the needle valve body assembly 3 and can block the spray hole 32, so that the high-pressure cavity 11 with stable pressure is formed in the injection valve body 1. When the pressure difference between the control chamber 22 and the nozzle pressure accumulation chamber 52 is enough to overcome the preload difference between the long needle valve preload spring 6 and the coupling sleeve pressure regulating spring 54, the long needle valve 4 starts to move upwards and opens the nozzle hole 32.

Further, the fuel injection valve further comprises a long needle valve adjusting gasket 7, the long needle valve adjusting gasket 7 is sleeved outside the first adjusting section 41, one end of the long needle valve adjusting gasket 7 is connected with the long needle valve pre-tightening spring 6, and the other end of the long needle valve adjusting gasket is abutted to the first step surface 421. By selecting different thicknesses of the long needle valve adjusting shim 7, the stroke of the long needle valve 4 can be adjusted.

Further, the injection valve body 1 is provided with an injection valve fuel inlet 12, and the injection valve fuel inlet 12 communicates with the high pressure chamber 11. The fuel inlet 12 of the injection valve is communicated with an external high-pressure oil way, so that the high-pressure fuel in the high-pressure cavity 11 is maintained stable, and the fuel leakage is avoided.

Further, the valve housing 2 is also provided with an oil outlet orifice 23, and the control chamber 22 communicates with an external relief chamber through the oil outlet orifice 23. Through the oil outlet orifice 23, the pressure in the control chamber 22 can be adjusted, thereby controlling the opening or closing of the long needle valve 4.

Further, the fuel injection valve further includes a control valve assembly 8, as shown in fig. 1 (see fig. 3), the control valve assembly 8 includes an electromagnet 81, a valve seat 82, and a ball valve 83, the valve seat 82 presses against the valve housing 2, the ball valve 83 is disposed between the valve seat 82 and the valve housing 2, and the electromagnet 81 can control the ball valve 83 to periodically block the oil outlet orifice 23. The valve sleeve 2 is connected and assembled with the injection valve body 1 by axial compression of the valve seat 82, forming a high-pressure seal of the high-pressure chamber 11. Preferably, the control valve assembly 8 further includes an armature 84, when the electromagnet 81 is energized, the armature 84 will control the ball valve 83 to open the outlet orifice 23, and the high-pressure fuel in the control chamber 22 can be vented through the outlet orifice 23.

Furthermore, the long needle valve 4 and the coupling sleeve 53 are matched by adopting a coupling piece, so that the guide performance and the sealing performance are good. Furthermore, the long needle valve 4 is matched with the valve sleeve 2 by adopting a matching part; the matching parts can ensure the sealing between the long needle valve 4 and the valve sleeve 2, prevent fuel oil leakage, ensure the effective sealing of the control cavity 22 and can also guide the long needle valve 4 in a sliding way.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations and substitutions will occur to those skilled in the art without departing from the scope of the invention. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A fuel injection valve characterized by comprising:

an injection valve body (1), the injection valve body (1) having a high-pressure chamber (11) for receiving fuel;

a valve sleeve (2), wherein the valve sleeve (2) is connected to the injection valve body (1) and seals one end of the high-pressure cavity (11), and the valve sleeve (2) is provided with a first accommodating cavity (21);

the needle valve body assembly (3) is detachably connected to one end of the injection valve body (1) and seals the other end of the high-pressure cavity (11), the needle valve body assembly (3) is provided with a second accommodating cavity (31), and one end, far away from the valve sleeve (2), of the needle valve body assembly (3) is provided with at least one spray hole (32);

the long needle valve (4) is slidably mounted in the first accommodating cavity (21) and the second accommodating cavity (31) and forms a control cavity (22) between the first accommodating cavity and the valve sleeve (2), the control cavity (22) is communicated with the high-pressure cavity (11), the long needle valve (4) is of an integrated structure, and the long needle valve (4) can be opened periodically or the spray holes (32) can be plugged; and

coupling cover subassembly (5), coupling cover subassembly (5) slip cap is located on long needle valve (4), coupling cover subassembly (5) with it overflows clearance (51) to have between injection valve body (1), it communicates to overflow clearance (51) one end high pressure chamber (11), the other end is provided with and is used for the intercommunication glib talker pressure accumulation chamber (52) of orifice (32), it is configured to adjust to overflow clearance (51) high pressure chamber (11) with pressure differential between glib talker pressure accumulation chamber (52).

2. The fuel injection valve according to claim 1, wherein the long needle valve (4) includes a first adjusting section (41), a connecting section (42) and a second adjusting section (43) which are connected in sequence, the first adjusting section (41) is slidably connected in the first accommodating chamber (21), the second adjusting section (43) is slidably connected in the second accommodating chamber (31), two ends of the connecting section (42) are respectively provided with a first step surface (421) and a second step surface (422), and the coupling sleeve assembly (5) is slidably sleeved on the second adjusting section (43) and can abut against the second step surface (422).

3. The fuel injection valve according to claim 2, characterized in that the coupling sleeve assembly (5) comprises:

the coupling sleeve (53) is slidably sleeved outside the second adjusting section (43);

coupling sleeve pressure regulating spring (54), coupling sleeve pressure regulating spring (54) set up in glib pressure storage chamber (52) are interior, the one end of coupling sleeve pressure regulating spring (54) is connected coupling sleeve (53), the other end is connected needle valve body subassembly (3), coupling sleeve pressure regulating spring (54) be used for to first pretightning force is applyed with the butt in coupling sleeve (53) second step face (422).

4. A fuel injection valve according to claim 3, characterized in that the needle valve body assembly (3) comprises:

the injection valve comprises a needle valve body (33), wherein one end of the needle valve body (33) is provided with at least one spray hole (32), the other end of the needle valve body is connected with the injection valve body (1), and the needle valve body (33) is internally provided with a second accommodating cavity (31);

tight cap (34) of glib talker, the tight cap (34) cover of glib talker is located on the needle valve body (33) to can dismantle connect in injection valve body (1).

5. The fuel injection valve according to claim 4, characterized in that the end of the needle valve body (33) connected to the injection valve body (1) is provided with a needle valve body sealing surface (331), and the end of the coupling sleeve (53) is provided with a coupling sleeve sealing surface (531), wherein the coupling sleeve sealing surface (531) can abut against the needle valve body sealing surface (331) and block off the nozzle tip pressure accumulation cavity (52).

6. The fuel injection valve according to claim 3, characterized in that the coupling sleeve assembly (5) further comprises a coupling sleeve lift adjusting shim (55), one end of the coupling sleeve lift adjusting shim (55) being capable of abutting the second step surface (422) and the other end being capable of abutting an end of the coupling sleeve (53) remote from the coupling sleeve pressure regulating spring (54).

7. The fuel injection valve according to claim 2, further comprising a long needle valve pre-tightening spring (6), wherein the long needle valve pre-tightening spring (6) is sleeved outside the first adjusting section (41), one end of the long needle valve pre-tightening spring (6) is connected with the valve sleeve (2), the other end of the long needle valve pre-tightening spring is connected with the long needle valve (4), and the long needle valve pre-tightening spring (6) is used for applying a second pre-tightening force to the long needle valve (4) to block the nozzle hole (32).

8. The fuel injection valve according to claim 7, further comprising a long needle valve adjusting gasket (7), wherein the long needle valve adjusting gasket (7) is sleeved outside the first adjusting section (41), one end of the long needle valve adjusting gasket (7) is connected with the long needle valve pre-tightening spring (6), and the other end of the long needle valve adjusting gasket abuts against the first step surface (421).

9. A fuel injection valve according to claim 1, characterized in that the injection valve body (1) is provided with an injection valve fuel inlet (12), which injection valve fuel inlet (12) communicates with the high pressure chamber (11).

10. A fuel injection valve according to claim 1, characterized in that the valve sleeve (2) also has an oil outlet orifice (23), the control chamber (22) communicating with an external pressure relief chamber through the oil outlet orifice (23).

11. The fuel injection valve according to claim 10, further comprising a control valve assembly (8), wherein the control valve assembly (8) comprises an electromagnet (81), a valve seat (82) and a ball valve (83), wherein the valve seat (82) presses against the valve housing (2), the ball valve (83) is arranged between the valve seat (82) and the valve housing (2), and the electromagnet (81) can control the ball valve (83) to periodically block the oil outlet orifice (23).

12. A fuel injection valve according to claim 3, characterized in that a coupling is used between the long needle valve (4) and the coupling sleeve (53).

13. A fuel injection valve according to any one of claims 1-12, characterized in that a coupling is used between the long needle valve (4) and the valve housing (2).