CN113944580A

CN113944580A - Ejector and engine

Info

Publication number: CN113944580A
Application number: CN202111324847.1A
Authority: CN
Inventors: 王�华; 顾小磊; 王凌云; 张涛
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2022-01-18
Anticipated expiration: 2041-11-10
Also published as: CN113944580B

Abstract

The invention belongs to the field of internal combustion engines, and discloses an ejector and an engine. The ejector comprises an ejector body, a needle valve, a valve sleeve, a valve seat plate and a valve core, wherein a first control cavity and a second control cavity are arranged on the valve core; the first oil inlet hole is formed in the valve sleeve and communicated with the oil inlet cavity and the third control cavity; the first hole section is communicated with the oil inlet cavity and the fourth control cavity; the second hole section is communicated with the fourth control cavity and the first control cavity; the first elastic assembly applies force towards the needle valve to the valve core; when the valve component closes the oil outlet, the first control cavity and the third control cavity are changed from cut-off to communication, the volume of the third control cavity is increased, the volume of the fourth control cavity is reduced, and the fourth control cavity and the second control cavity are changed from communication to cut-off, so that the needle valve is separated from the valve core. The fuel injector has good opening response performance, and the needle valve can quickly close the fuel injection port, thereby reducing the emission of soot and reducing the fuel consumption.

Description

Ejector and engine

Technical Field

The invention relates to the field of internal combustion engines, in particular to an ejector and an engine.

Background

In an engine, fuel is injected into a combustion chamber via an injector in an amount and for a period of time. The high-pressure common rail technology is as follows: the high-pressure fuel oil is conveyed to the public oil supply pipe by the high-pressure oil pump, and the oil pressure in the public oil supply pipe is accurately controlled, so that the pressure of the high-pressure oil pipe is irrelevant to the rotating speed of the engine, and the degree of the oil supply pressure of the diesel engine changing along with the rotating speed of the engine can be greatly reduced. The high-pressure trend of the high-pressure common rail technology improves the oil injection pressure and the injection efficiency, but the problems that the injection response is slow, the closing of an oil injection port is slow and the like are caused at the same time.

Disclosure of Invention

An object of the present invention is to provide an injector which has good injection opening response and in which an injection port can be closed quickly.

In order to realize the purpose, the following technical scheme is provided:

provided is an ejector including:

the fuel injector comprises an injector body, a fuel inlet and a fuel outlet, wherein an oil inlet cavity is formed on the injector body;

the needle valve penetrates through the oil inlet cavity, and the tail part of the needle valve can open or close the oil injection port;

the valve sleeve is arranged in the oil inlet cavity, and the head of the needle valve is movably inserted into the valve sleeve;

the valve seat plate is arranged on one side, away from the needle valve, of the valve sleeve and used for plugging the oil inlet cavity, and an oil outlet is formed in the valve seat plate;

the valve core is movably arranged in the valve sleeve, a first control cavity and a second control cavity which are communicated are arranged on the valve core, the first control cavity is communicated with the oil outlet, the head part of the needle valve is exposed in the second control cavity, a third control cavity is formed among the valve core, the valve seat plate and the valve sleeve, and a fourth control cavity is formed among the valve core, the valve sleeve and the head part of the needle valve;

the first oil inlet hole is formed in the valve sleeve and communicated with the oil inlet cavity and the third control cavity;

a second oil inlet hole, comprising:

the first hole section is arranged on the valve sleeve and communicated with the oil inlet cavity and the fourth control cavity;

the second hole section is arranged on the valve core and communicated with the fourth control cavity and the first control cavity;

the first elastic assembly is used for applying elastic force towards the needle valve to the valve core;

a valve assembly capable of opening or closing the oil outlet hole;

when the valve component closes the oil outlet, the first control cavity and the third control cavity are switched from cut-off to communication, the volume of the third control cavity is increased, meanwhile, the volume of the fourth control cavity is reduced, the fourth control cavity and the second control cavity are switched from communication to cut-off, and the needle valve is separated from the valve core.

Optionally, when the valve assembly opens the oil outlet, the fourth control chamber and the second control chamber are switched from cut-off to communication, and the volume of the fourth control chamber is increased while the volume of the third control chamber is decreased until the third control chamber and the first control chamber are switched from communication to cut-off.

Optionally, the oil outlet is the shoulder hole, including the first oil outlet and the second oil outlet of intercommunication, the aperture of first oil outlet is greater than the aperture of second oil outlet, first oil outlet is located the second oil outlet is close to the one end in first control chamber, the one end of first elastic component stretches into in the first oil outlet, the other end stretches into in the first control chamber.

Optionally, the first resilient component comprises a spring; or the like, or, alternatively,

first elastic component includes leaf spring and sleeve pipe, the leaf spring set up in the first oil outlet, the sleeve pipe set up in the first control chamber, and stretch into in the first oil outlet with the leaf spring butt, set up the first intercommunicating hole that runs through its wall thickness on the sleeve pipe, first intercommunicating hole with second hole section intercommunication is provided with the second intercommunicating hole on the shown leaf spring, and shown second intercommunicating hole intercommunication sheathed tube inner chamber with the second oil outlet.

Optionally, a first convex ring is arranged on one side, facing the valve core, of the valve seat plate, the first convex ring is arranged around the first oil outlet hole, and when the valve core abuts against an end face of the first convex ring, the first control cavity and the third control cavity are cut off; or the like, or, alternatively,

the case orientation one side of valve seat board is provided with first bulge loop, first bulge loop centers on the accent setting in first control chamber, the terminal surface of first bulge loop with during the valve seat board butt, will first control chamber with the third control chamber cuts off.

Optionally, a second convex ring is arranged on one side of the valve core facing the valve sleeve, and when the end surface of the second convex ring abuts against the valve sleeve, the second convex ring surrounds the head of the needle valve to cut off the second control cavity and the fourth control cavity; or the like, or, alternatively,

and one side of the valve sleeve, which faces the valve core, is provided with a second convex ring, the second convex ring surrounds the head part of the needle valve, and the end surface of the second convex ring is abutted against the valve core to cut off the second control cavity and the fourth control cavity.

Optionally, still include the second elastic component, set up in the oil feed chamber, the one end of second elastic component with the valve barrel is connected, the other end with the needle valve is connected, the second elastic component to the valve barrel is applied towards the elastic force of valve seat board.

Optionally, the second control chamber is a tapered hole, and the aperture of the tapered hole close to one end of the first control chamber is smaller than the aperture of the tapered hole close to one end of the needle valve.

Optionally, the valve assembly is disposed coaxially with the needle valve.

Another object of the present invention is to provide an engine in which the injection opening response is good and the injection port can be closed quickly.

In order to realize the purpose, the following technical scheme is provided:

an engine is provided comprising an injector as described above.

The invention has the beneficial effects that:

in the injector provided by the invention, when the valve component opens the oil outlet, the third control cavity and the first control cavity are cut off, the valve core is separated from the valve sleeve, and the fourth control cavity and the second control cavity are communicated to form a larger first communication cavity. In the process that the valve component closes the oil outlet, the third control cavity is communicated with the first control cavity to form a second communication cavity, and the first oil inlet hole and the second oil inlet hole simultaneously feed oil, so that the volume of the second communicating cavity is rapidly increased from small to large, so that the valve core and the needle valve move downwards rapidly, the volume of a first communication chamber formed by the communication of the second control chamber and the fourth control chamber is reduced from large to small until the valve core is abutted with the valve sleeve to cut off the second control chamber and the fourth control chamber (the volume of the control chamber at the head part of the needle valve is reduced), but the first oil inlet hole and the second oil inlet hole simultaneously feed oil into the valve sleeve, so that the hydraulic pressure of the head part (the second control cavity) of the needle valve is quickly increased, and simultaneously under the effect of the elastic force of the first elastic component, the needle valve moves downwards fast relative to the valve core so as to close the oil injection port fast, reduce the soot emission of the engine and reduce the oil consumption. In addition, when the oil injection is finished, the needle valve is separated from the valve core, so that when the subsequent oil outlet hole is opened and the hydraulic pressure in the second communication chamber is quickly reduced, the hydraulic pressure in the second control chamber of the head part of the needle valve is also quickly reduced, the needle valve is quickly pre-lifted by a small lift before the valve core until the head part of the needle valve is contacted with the valve core, and the oil injection opening response performance of the injector is good.

The engine provided by the invention has good response performance of oil injection opening, and the needle valve can quickly close the oil injection port, reduce the soot emission of the engine and reduce the oil consumption.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a cross-sectional view of an injector (valve assembly energized, injector injecting) provided by an embodiment of the present invention;

FIG. 2 is a cross-sectional view of an injector (with the valve assembly de-energized and the injector de-energized) provided by an embodiment of the present invention;

FIG. 3 is a cross-sectional view of a valve cartridge provided in accordance with an embodiment of the present invention;

FIG. 4 is a sectional view showing a partial structure of an injector (valve assembly energized, injector injecting) according to an embodiment of the present invention;

FIG. 5 is a sectional view showing a partial structure of an injector (the valve assembly is de-energized and the injector stops injecting fuel) according to an embodiment of the present invention;

fig. 6 is a sectional view showing a partial structure of an injector according to another embodiment of the present invention.

Reference numerals:

100. an oil inlet cavity; 200. a third control chamber; 300. a fourth control chamber;

1. an injector body; 2. a needle valve; 3. a valve housing; 4. a valve seat plate; 5. a valve core; 6. a valve assembly; 7. a first elastic member; 8. a second elastic member; 9. a guide plate;

11. an injector upper body; 12. the lower body of the oil injector; 13. a needle valve body; 14. a first integral locking cap;

111. an oil drain hole;

121. a first bore hole; 122. an oil inlet;

131. a second bore; 132. an oil injection port;

31. a first oil inlet hole; 32. a first bore section;

41. an oil outlet hole; 42. a first convex ring;

411. a first oil outlet hole; 412. a second oil outlet hole;

51. a first control chamber; 52. a second control chamber; 53. an orifice; 54. a second bore section; 55. a second convex ring;

61. an electromagnetic valve; 62. an armature; 63. an armature rod; 64. a return spring;

71. a plate spring; 72. a sleeve;

711. a second communication hole; 721. the first through hole.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1 and 2, the present embodiment provides an injector including an injector body 1, a needle 2, a valve sleeve 3, a valve seat plate 4, a valve spool 5, a valve assembly 6, and a first elastic assembly 7.

Specifically, the injector body 1 includes an injector upper body 11, an injector lower body 12, a needle valve body 13, and a first tightening cap 14, which are arranged in this order from top to bottom. The injector upper body 11 and the injector lower body 12 are coaxially disposed and are fixedly connected by a second body locking cap (not shown). The needle valve body 13 is coaxially connected to the bottom end of the lower injector body 12, and both are fixedly connected by a first tightening cap 14. The injector lower body 12 is provided with a first bore 121, the needle valve body 13 is provided with a second bore 131 coaxial and communicated with the first bore 121, and the bottom end of the needle valve body 13 is provided with an oil injection port 132. The needle valve 2 is inserted through the first bore 121 and the second bore 131. An oil inlet chamber 100 is formed between the needle valve 2 and the injector lower body 12 and the needle valve body 13. An oil inlet 122 communicating with the oil inlet chamber 100 is provided in the injector lower body 12. High pressure fuel enters the fuel inlet chamber 100 through the fuel inlet 122. The needle valve 2 is movable in the axial direction of the first bore 121 and the second bore 131, so that the rear portion of the needle valve 2 can open or close the oil jet 132. When the fuel injection port 132 is opened, high-pressure fuel in the oil inlet chamber 100 is injected from the fuel injection port 132; when the oil jet 132 is closed, the injection ends.

The valve sleeve 3 is arranged in the first bore 121 and is positioned at the head of the needle valve 2, and the head of the needle valve 2 is movably inserted in the valve sleeve 3. The valve seat plate 4 is arranged at one end of the valve sleeve 3, which faces away from the needle valve 2, and is tightly matched with the first boring hole 121. The valve seat plate 4 is sealingly connected to the injector body to block the oil inlet chamber 100. The valve seat plate 4 is provided with an oil outlet hole 41.

The valve assembly 6 is located on the side of the valve seat plate 4 remote from the valve sleeve 3. The valve assembly 6 can open or close the oil outlet hole 41. In this embodiment, the valve assembly 6 is disposed at an end of the injector body away from the oil injection port 132 and extends into the first bore 121 to open or close the oil outlet hole 41.

Referring to fig. 1 to 5, a spool 5 is movably disposed in the valve housing 3, the spool 5 is provided with a first control chamber 51, a second control chamber 52 and an orifice 53, and the first control chamber 51 and the second control chamber 52 are communicated through the orifice 53. An end of the first control chamber 51 remote from the orifice 53 communicates with the oil outlet hole 41, and a head portion of the needle valve 2 is exposed to an end of the second control chamber 52 remote from the orifice 53. A third control chamber 200 is formed between the valve core 5, the valve seat plate 4 and the valve sleeve 3. A fourth control chamber 300 is formed between the valve spool 5, the valve sleeve 3 and the head of the needle 2. The injector further includes a first oil inlet hole 31 and a second oil inlet hole. The first oil inlet hole 31 is formed in the valve housing 3 and communicated with the oil inlet chamber 100 and the third control chamber 200, and high-pressure fuel in the oil inlet chamber 100 enters the third control chamber 200 through the first oil inlet hole 31. The second oil inlet hole includes a first hole section 32 and a second hole section 54. The first bore section 32 opens onto the valve housing 3 and communicates with the inlet chamber 100 and the fourth control chamber 300. The second bore section 54 opens in the valve spool 5 and communicates the fourth control chamber 300 with the first control chamber 51. The high-pressure fuel in the oil inlet chamber 100 enters the fourth control chamber 300 through the first orifice section 32, and a portion of the high-pressure fuel entering the fourth control chamber 300 enters the first control chamber 51 through the second orifice section 54. The flow rate of the oil outlet hole 41, the flow rate of the first oil inlet hole 31, the flow rate of the orifice 53, and the flow rate of the second oil inlet hole are sequentially decreased.

It will be appreciated that when the spool 5 moves downwardly to disengage from the valve seat plate 4, the third control chamber 200 communicates with the first control chamber 51; when the spool 5 moves upward to abut against the valve seat plate 4, the third control chamber 200 is shut off from the first control chamber 51. Similarly, when the spool 5 moves upward to disengage from the sleeve 3, the fourth control chamber 300 communicates with the second control chamber 52; when the spool 5 moves down into abutment with the sleeve 3, the fourth control chamber 300 is shut off from the second control chamber 52.

One end of the first elastic member 7 is connected to the valve body 5, and the other end is connected to the valve seat plate 4, and the first elastic member 7 applies an elastic force to the valve body 5 toward the needle 2. That is, the valve body 5 and the needle 2 always tend to move away from the valve seat plate 4 by the elastic force of the first elastic member 7.

When the valve assembly 6 closes the oil outlet hole 41, the first control chamber 51 is changed from the cutoff to the communication with the third control chamber 200, and the volume of the third control chamber 200 is increased while the volume of the fourth control chamber 300 is decreased until the fourth control chamber 300 is changed from the communication to the cutoff with the second control chamber 52, and the needle valve 2 is separated from the spool 5.

Specifically, when oil injection is required, the valve assembly 6 is energized, the oil outlet 41 is opened, the needle valve 2 and the valve core 5 both move upward, the tail portion of the needle valve 2 completely opens the oil injection port 132, and high-pressure fuel in the oil inlet chamber 100 is injected from the oil injection port 132. In this process, the valve element 5 moves upward to abut against the valve seat plate 4, the third control chamber 200 and the first control chamber 51 are shut off, and the valve element 5 is separated from the valve sleeve 3, the fourth control chamber 300 and the second control chamber 52 are communicated to form a large first communication chamber, and at this time, the needle valve 2 moves upward to contact with the valve element 5.

When the fuel injection needs to be stopped, the valve assembly 6 is powered off to close the oil outlet 41, but the high-pressure fuel in the fuel inlet chamber 100 still continues to enter the third control chamber 200 through the first fuel inlet 31, and continues to enter the fourth control chamber 300 through the first hole section 32 (a part of the high-pressure fuel entering the fourth control chamber 300 enters the second control chamber 52 communicated with the fourth control chamber, and a part of the high-pressure fuel enters the first control chamber 51 through the second hole section 54, so that the hydraulic pressure is increased, and therefore, under the combined action of the elastic force of the first elastic assembly 7 and the hydraulic pressure acting on the upper end of the valve core 5 (the hydraulic pressure mainly comes from the third control chamber 200), the valve core 5 (and the needle valve 2) moves downwards and is separated from the valve seat plate 4, the third control chamber 200 is communicated with the first control chamber 51 to form a larger second communication chamber, and the first fuel inlet 31 and the second fuel inlet are simultaneously filled, so that the volume and hydraulic pressure of the first communicating chamber are continuously increased to drive the valve core 5 and the needle valve 2 to rapidly move downwards. Meanwhile, as the hydraulic pressure in the first control chamber 51 increases, the hydraulic pressure in the second control chamber 52 communicated with the first control chamber 51 also increases, so that the needle valve 2 moves downward relative to the valve spool 5 and is separated from the valve spool 5, and the communication between the second communication chamber and the first communication chamber is realized. As the high-pressure fuel in the oil inlet chamber 100 continues to enter, the valve core 5 moves downward rapidly under the action of the hydraulic pressure and the elastic force of the first elastic component 7 until the valve core abuts against the valve sleeve 3, so as to cut off the second control chamber 52 and the fourth control chamber 300, and then as the hydraulic pressure in the second control chamber 52 continues to rise, the head of the needle valve 2 moves downward rapidly until the tail of the needle valve 2 completely closes the oil injection port 132, and the oil injection is finished.

As can be seen from the above, in the process that the valve assembly 6 is de-energized to close the oil outlet 41, the third control chamber 200 and the first control chamber 51 are communicated to form a second communication chamber, and the first oil inlet hole 31 and the second oil inlet hole are simultaneously fed with oil, so that the volume of the second communication chamber is rapidly increased from small to large, so that the valve core 5 and the needle valve 2 are rapidly moved downward, and the volume of the first communication chamber formed by the communication between the second control chamber 52 and the fourth control chamber 300 is decreased from large to small until the valve core 5 abuts against the valve sleeve 3 to cut off the second control chamber 52 and the fourth control chamber 300 (the volume of the control chamber at the head of the needle valve 2 is decreased), but the first oil inlet hole 31 and the second oil inlet hole are simultaneously fed into the valve sleeve 3, so that the hydraulic pressure at the head of the needle valve 2 (the second control chamber 52) is rapidly increased, and at the same time, under the elastic force of the first elastic assembly 7, the needle valve 2 is rapidly moved downward relative to the valve core 5, so as to quickly close the fuel injection port 132, reduce the soot emission of the engine and reduce the fuel consumption. In addition, as can be seen from the above, when the valve body 5 moves downward to abut against the valve sleeve 3, the needle 2 still moves downward a certain distance relative to the valve body 5, that is, the stroke of the downward movement of the needle 2 is larger than that of the downward movement of the valve body 5, and when the oil injection is finished, the needle 2 is separated from the valve body 5, and the distance between the two is set to be L1.

When the valve assembly 6 opens the oil outlet hole 41, the fourth control chamber 300 is changed from the cutoff to the communication with the second control chamber 52, and the volume of the fourth control chamber 300 is increased while the volume of the third control chamber 200 is decreased until the third control chamber 200 is changed from the communication with the first control chamber 51 to the cutoff.

Specifically, when fuel injection is required, the valve assembly 6 is energized to open the oil outlet hole 41, the high-pressure fuel in the second communication chamber flows out through the oil outlet hole 41, the hydraulic pressure in the second communication chamber rapidly decreases, and thus the hydraulic pressure acting in the second control chamber 52 at the head of the needle valve 2 also rapidly decreases, so that the needle valve 2 is quickly pre-lifted by a small lift (L1), the head of the needle valve 2 is in contact with the valve element 5, and the fuel injection opening response performance of the injector is good. Then, as the oil outlet amount continues to increase, the hydraulic pressure in the second communication chamber further decreases, and as the first oil inlet hole 31 and the second oil inlet hole continuously feed oil into the valve core 5, so that the hydraulic pressure below the valve core 5 (which comes from the second control chamber 52 and the fourth control chamber 300) is higher than the hydraulic pressure above the valve core 5 (which comes from the second communication chamber, i.e., the first control chamber 51 and the third control chamber 200), when the hydraulic pressure difference between the upper side and the lower side of the valve core 5 is large enough, the valve core 5 overcomes the elastic force of the first elastic component 7 and moves upward by the distance of L2, the valve core 5 abuts against the valve seat plate 4, thereby cutting off the first control chamber 51 and the second control chamber 52, the high-pressure fuel entering the second control chamber 52 from the first oil inlet hole 31 cannot flow out through the oil outlet hole 41 (the flow rate of the first oil inlet hole 31 is greatly reduced), and only the high-pressure fuel entering the valve sleeve 3 through the second oil inlet hole can flow out through the oil outlet hole 41, that is, the two oil inlet holes are switched to the single oil inlet hole, and at the same time, the needle valve 2 connected to the valve core 5 continues to lift up the L2 due to the decrease of the hydraulic pressure of the second control chamber 52 and contacts the valve core 5 again, thereby effectively reducing the dynamic oil return amount. The lift of the needle valve 2 is firstly small and then large (firstly lifting L1 and then lifting L1+ L2), the fuel injector has good fuel injection opening response, the volume of the second communication cavity is reduced from large to small in the processes of moving the valve core 5 and lifting the needle valve 2, the third control cavity 200 and the first control cavity 51 are cut off, only the second oil inlet hole is filled with fuel, the dynamic oil return amount is effectively reduced, the injection effect that the fuel injection rate is firstly slow and then fast is realized, the ideal fuel injection efficiency of the internal combustion engine is achieved, the combustion noise and particle emission are reduced, and the diffusion combustion is promoted.

It can be understood that the dynamic oil return amount can be adjusted by selecting the number of the first oil inlet hole 31 and the second oil inlet hole.

Optionally, the oil outlet 41 is a stepped hole and includes a first oil outlet 411 and a second oil outlet 412 which are communicated with each other, the aperture of the first oil outlet 411 is larger than that of the second oil outlet 412, the first oil outlet 411 is located at one end of the second oil outlet 412 close to the first control chamber 51, one end of the first elastic component 7 extends into the first oil outlet 411 and abuts against the stepped surface, and the other end extends into the first control chamber 51. The first elastic assembly 7 is arranged in the first oil outlet 411 and the first control cavity 51, so that the installation is stable, the first elastic assembly 7 is prevented from being deformed in a direction deviating from the movement direction of the valve core 5, and effective elastic force is applied to the valve core 5 and the needle valve 2.

In this embodiment, the first elastic component 7 includes a spring, which is easy to obtain, convenient to install and low in cost. The elastic force applied to the valve core 5 and the needle valve 2 can be adjusted by selecting the specification of the spring, so that the valve core 5 and the needle valve 2 can be ensured to move downwards quickly, and the oil injection port 132 can be closed quickly.

Referring to fig. 6, in another embodiment, the first elastic assembly 7 includes a plate spring 71 and a sleeve 72, the plate spring 71 is disposed in the first oil outlet 411, and the sleeve 72 is disposed in the first control chamber 51 and extends into the first oil outlet 411 to abut against the plate spring 71. The sleeve 72 is provided with a first communication hole 721 penetrating the wall thickness thereof, and the first communication hole 721 is communicated with the second hole section 54. The plate spring 71 is provided with a second communication hole 711, and the second communication hole 711 communicates the inner cavity of the sleeve 72 with the second oil outlet 412. The spring is replaced by the plate spring 71 and the sleeve 72, and the pre-compression amount of the plate spring 71 can be adjusted by selecting the sleeve 72 with different lengths, so that the plate spring can apply enough elastic force to the valve core 5 and the needle valve 2.

Referring again to fig. 3 to 5, in the present embodiment, the first projecting ring 42 is provided on the side of the valve seat plate 4 facing the valve body 5, the first projecting ring 42 is provided around the first oil outlet hole 411, and when the valve body 5 abuts against the end surface of the first projecting ring 42, the first control chamber 51 and the third control chamber 200 are shut off. The first convex ring 42 is arranged on one side of the valve seat plate 4 facing the valve core 5, that is, one side of the valve seat plate 4 facing the valve core 5 is a step surface, the structure is simple, the processing is convenient, the sealing effect between the first convex ring 42 and the valve core 5 is good, and the first control cavity 51 and the third control cavity 200 are effectively cut off.

In another embodiment, the first protrusion may be provided on the side of the valve element 5 facing the valve seat plate 4, the first protruding ring 42 may be provided around the opening of the first control chamber 51, when the end surface of the first protruding ring 42 abuts against the valve seat plate 4, the first control chamber 51 and the third control chamber 200 may be cut off, the sealing effect between the first protruding ring 42 and the valve seat plate 4 is good, the first control chamber 51 and the third control chamber 200 may be effectively cut off, the structure is simple, and the processing is convenient.

In this embodiment, the second projecting ring 55 is provided on the side of the valve element 5 facing the valve housing 3, and when the end surface of the second projecting ring 55 abuts against the valve housing 3, the second projecting ring 55 surrounds the head of the needle 2 and cuts off the second control chamber 52 and the fourth control chamber 300. The second convex ring 55 is arranged on one side of the valve core 5 facing the valve sleeve 3, that is, one side of the valve core 5 facing the valve sleeve 3 is a step surface, so that the processing is convenient, the sealing effect between the second convex ring 55 and the valve sleeve 3 is good, and the second control cavity 52 and the fourth control cavity 300 are effectively cut off.

Further, the inner diameter of the second collar 55 is larger than the size of the head of the needle 2, that is, the second control chamber 52 is kept in communication with the fourth control chamber 300 when the head of the needle 2 is in contact with the valve spool 5.

In other embodiments, the second convex ring 55 may be disposed on a side surface of the valve sleeve 3 facing the valve core 5, the second convex ring 55 surrounds a head portion of the needle valve 2, and when an end surface of the second convex ring 55 abuts against the valve core 5, the second control chamber 52 and the fourth control chamber 300 are cut off, which is simple in structure and convenient to machine.

Alternatively, referring to fig. 1 and 2, the injector further includes a second elastic member 8 disposed in the oil inlet chamber 100, and one end of the second elastic member 8 is connected to the valve sleeve 3 and the other end is connected to the needle 2, and the second elastic member 8 applies an elastic force to the valve sleeve 3 toward the valve seat plate 4 to seal the contact surface of the valve sleeve 3 with the valve seat plate 4. At the same time, the second spring assembly 8 also exerts a spring force on the needle valve 2 that is directed away from the valve sleeve 3, so that the needle valve 2 always has a tendency to move away from the valve sleeve 3 in order to close the injection opening 132. The second elastic component 8 and the first elastic component 7 work together to push the needle valve 2 to move downwards to close the oil injection port 132, and after the needle valve 2 lifts up by the lift of the L1, the movement of the needle valve 2 is buffered, so that the needle valve 2 is prevented from lifting too fast. Exemplarily, the second elastic component 8 comprises a spring, which is easy to obtain and convenient to install. Alternatively, the circumferential wall of the needle valve 2 is provided with a flange, a spring is sleeved on the needle valve 2, one end of the spring is connected with the flange, and the other end is connected with the lower end face of the valve sleeve 3.

Optionally, referring to fig. 1 to 5, the second control chamber 52 is a tapered hole, and the diameter of the tapered hole at one end close to the first control chamber 51 is smaller than the diameter of the tapered hole at one end close to the needle valve 2, that is, the head of the needle valve 2 is exposed at the large hole end of the tapered hole, and after passing through the orifice 53, the high-pressure fuel in the first control chamber 51 flows into the tapered hole, and the tapered hole plays a role in reducing the speed and slowing the flow, so as to ensure that the head of the needle valve 2 is uniformly and stably stressed, thereby ensuring the smooth movement of the needle valve 2 and ensuring the injection stability. Further optionally, the head end face of the needle valve 2 is perpendicular to the axial direction of the needle valve, and the head end face of the needle valve 2 is a plane, so that the stress at each position of the head of the needle valve 2 is further ensured to be uniform and stable, and the injection stability is ensured.

Alternatively, referring to fig. 1 and 2, the valve assembly 6 is arranged on the injector body 1 coaxially with the needle valve 2, so that the space of the injector body 1 can be reasonably and effectively utilized, and the overall size of the injector can be reduced.

Illustratively, the valve assembly 6 includes a solenoid valve 61, an armature 62, an armature rod 63, and a return spring 64. The electromagnetic valve 61 is provided in the injector upper body 11. The armature 62 and the armature rod 63 are connected between the solenoid valve 61 and the valve seat plate 4. The return spring 64 is connected between the armature 62 and the solenoid valve 61. When the electromagnetic valve 61 is energized, the armature 62 is driven to move upwards, and the armature 62 drives the armature rod 63 to open the oil outlet 41 on the valve seat plate 4. When the electromagnetic valve 61 is powered off, the return spring 64 drives the armature 62 to move downwards, and the armature 62 drives the armature rod 63 to close the oil outlet 41.

Optionally, the injector further comprises a guide plate 9, the guide plate 9 being disposed in the first bore 121 of the lower injector body 12 and between the valve seat plate 4 and the upper injector body 11. The guide plate 9 is provided with a guide hole which is in dead-against communication with the oil outlet hole 41. The end of the armature 62 remote from the solenoid valve 61 is pierced with a guide hole. The guide hole is used to guide the up-and-down sliding of the armature 62. Further, the injector upper body 11 is provided with a drain hole 111, and one end of the return spring 64 remote from the armature 62 is mounted in the drain hole 111. The fuel flowing out of the oil outlet hole 41 flows between the guide plate 9 and the injector upper body 11 through the guide hole first, and then flows out through the oil discharge hole 111.

The embodiment also provides an engine, which comprises the injector, the fuel injection opening response performance is good, the dynamic oil return amount is less, the injection effect that the fuel injection speed is slow first and then fast can be realized, the ideal fuel injection efficiency of the internal combustion engine is achieved, the combustion noise and particle emission are reduced, the diffusion combustion is promoted, the needle valve 2 can quickly close the fuel injection port 132, the soot emission of the engine is reduced, and the fuel consumption is reduced.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An injector, comprising:

the fuel injection device comprises an injector body (1), wherein an oil inlet cavity (100) is formed in the injector body (1), and an oil injection port (132) is formed in the injector body (1);

the needle valve (2) penetrates through the oil inlet cavity (100), and the tail part of the needle valve (2) can open or close the oil injection port (132);

the valve sleeve (3) is arranged in the oil inlet cavity (100), and the head of the needle valve (2) is movably inserted into the valve sleeve (3);

the valve seat plate (4) is arranged on one side, away from the needle valve (2), of the valve sleeve (3) and used for plugging the oil inlet cavity (100), and an oil outlet (41) is formed in the valve seat plate (4);

the valve core (5) is movably arranged in the valve sleeve (3), a first control cavity (51) and a second control cavity (52) which are communicated with each other are arranged on the valve core (5), the first control cavity (51) is communicated with the oil outlet (41), the head of the needle valve (2) is exposed to the second control cavity (52), a third control cavity (200) is formed among the valve core (5), the valve seat plate (4) and the valve sleeve (3), and a fourth control cavity (300) is formed among the valve core (5), the valve sleeve (3) and the head of the needle valve (2);

the first oil inlet hole (31) is formed in the valve sleeve (3) and communicated with the oil inlet cavity (100) and the third control cavity (200);

a second oil inlet hole, comprising:

a first bore section (32) disposed in the valve housing (3) and communicating the oil inlet chamber (100) and the fourth control chamber (300);

a second bore section (54) provided on the spool (5) and communicating the fourth control chamber (300) and the first control chamber (51);

a first elastic assembly (7) for applying an elastic force to the valve spool (5) toward the needle valve (2);

a valve assembly (6) capable of opening or closing the oil outlet hole (41);

when the valve assembly (6) is closed the oil outlet (41), the first control cavity (51) and the third control cavity (200) are switched from cut-off to communication, the volume of the third control cavity (200) is increased, meanwhile, the volume of the fourth control cavity (300) is reduced, the fourth control cavity (300) and the second control cavity (52) are switched from communication to cut-off, and the needle valve (2) is separated from the valve core (5).

2. The injector as claimed in claim 1, characterized in that when the valve assembly (6) opens the oil outlet hole (41), the fourth control chamber (300) is changed from cut-off to communication with the second control chamber (52), and the volume of the fourth control chamber (300) is increased while the volume of the third control chamber (200) is decreased until the third control chamber (200) is changed from communication with the first control chamber (51) to cut-off.

3. The injector according to claim 2, characterized in that the oil outlet hole (41) is a stepped hole including a first oil outlet hole (411) and a second oil outlet hole (412) which are communicated, the first oil outlet hole (411) has a larger hole diameter than the second oil outlet hole (412), the first oil outlet hole (411) is located at one end of the second oil outlet hole (412) close to the first control chamber (51), one end of the first elastic member (7) extends into the first oil outlet hole (411), and the other end extends into the first control chamber (51).

4. The injector according to claim 3, characterized in that said first elastic assembly (7) comprises a spring; or the like, or, alternatively,

the first elastic assembly (7) comprises a plate spring (71) and a sleeve (72), the plate spring (71) is arranged in the first oil outlet (411), the sleeve (72) is arranged in the first control cavity (51) and extends into the first oil outlet (411) to be abutted against the plate spring (71), a first communication hole (721) penetrating through the wall thickness of the sleeve (72) is formed in the sleeve (72), the first communication hole (721) is communicated with the second hole section (54), a second communication hole (711) is formed in the plate spring (71), and the second communication hole (711) is communicated with an inner cavity of the sleeve (72) and the second oil outlet (412).

5. The injector according to claim 3, characterized in that a first collar (42) is provided on a side of the valve seat plate (4) facing the valve element (5), the first collar (42) is provided around the first oil outlet hole (411), and the first control chamber (51) and the third control chamber (200) are shut off when the valve element (5) abuts on an end surface of the first collar (42); or the like, or, alternatively,

one side of the valve core (5) facing the valve seat plate (4) is provided with a first convex ring (42), the first convex ring (42) surrounds the orifice of the first control cavity (51), and when the end surface of the first convex ring (42) is abutted against the valve seat plate (4), the first control cavity (51) and the third control cavity (200) are cut off.

6. The injector as claimed in claim 3, characterized in that the side of the valve spool (5) facing the valve sleeve (3) is provided with a second collar (55), the second collar (55) surrounding the head of the needle (2) when the end face of the second collar (55) abuts against the valve sleeve (3) and cutting off the second control chamber (52) and the fourth control chamber (300); or the like, or, alternatively,

one side, facing the valve core (5), of the valve sleeve (3) is provided with a second convex ring (55), the second convex ring (55) surrounds the head of the needle valve (2), and when the end face of the second convex ring (55) is abutted to the valve core (5), the second control cavity (52) and the fourth control cavity (300) are cut off.

7. The injector as claimed in claim 2, characterized by further comprising a second elastic member (8) disposed in the oil feed chamber (100), one end of the second elastic member (8) being connected with the valve sleeve (3) and the other end being connected with the needle valve (2), the second elastic member (8) applying an elastic force to the valve sleeve (3) toward the valve seat plate (4).

8. Injector according to any one of claims 1-7, characterized in that the second control chamber (52) is a conical bore, the diameter of which at the end close to the first control chamber (51) is smaller than at the end close to the needle valve (2).

9. Injector according to any one of claims 1-7, characterized in that the valve assembly (6) is arranged coaxially with the needle valve (2).

10. An engine comprising an injector as claimed in any one of claims 1 to 9.