CN117345495A

CN117345495A - Fuel injector flow limiting device

Info

Publication number: CN117345495A
Application number: CN202311521055.2A
Authority: CN
Inventors: 赖学军; 周斌; 鲜苇; 万长久; 蒋宇
Original assignee: Heavy Oil High Tech Electronic Fuel Injection System Co ltd
Current assignee: Heavy Oil High Tech Electronic Fuel Injection System Co ltd
Priority date: 2023-11-15
Filing date: 2023-11-15
Publication date: 2024-01-05

Abstract

The application relates to the technical field of fuel injectors, in particular to a fuel injector flow limiting device, which comprises a valve body, a valve seat, a valve sleeve and a spring; the valve body is of a hollow pipe sleeve structure and comprises an oil inlet end positioned at the left side and an oil outlet end positioned at the right side; a first step and a second step are arranged at one side of the oil outlet end and positioned in the valve body, and an oil outlet is arranged at the right side of the second step; a valve seat is arranged at one side of the oil inlet end, and a first through hole is arranged in the valve seat; the valve seat and the valve body form a valve cavity for the valve sleeve to reciprocate; the right side of the valve sleeve is provided with a first counter bore, the left side of the spring is arranged in the first counter bore, and the right side of the spring is abutted with the second step; the outer wall of the valve sleeve is provided with an oil drain passage, one end of the oil drain passage is communicated with the first through hole, and the other end of the oil drain passage is communicated with the oil outlet through the valve cavity. When the fuel flow is normal, the fuel pressure in the fuel injector is kept stable by the fuel injector flow limiting device, and when the fuel flow is abnormal, the fuel is blocked from flowing out of the valve body, so that the maximum injection flow of the fuel injector is controlled, and accidents are prevented from happening or being amplified.

Description

Fuel injector flow limiting device

Technical Field

The application relates to the technical field of fuel injectors, in particular to a fuel injector flow limiting device.

Background

With the increasing requirements of emission regulations, in order to meet the emission of engines, large diesel engines also gradually adopt an electrically controlled high-pressure common rail fuel injection system, and common rail type electrically controlled fuel injection technology directly or indirectly forms constant high-pressure fuel through a common rail, distributes the constant high-pressure fuel to each fuel injector, and controls the fuel quantity injected into a combustion chamber of the diesel engine by means of opening and closing a high-speed electromagnetic switch valve integrated on each fuel injector at fixed time and quantitatively, so as to ensure that the diesel engine achieves the optimal combustion ratio and good atomization, and optimal ignition time, enough ignition energy and minimum pollution emission. Because large diesel engines are mostly used on generator sets and ships, the price is high, the safety requirement is extremely high, and the reliability and the safety of the use of the electric control high-pressure common rail fuel injector are important.

The fuel injector for the large diesel engine has large flow, and the fuel quantity sprayed by the fuel injector can become uneven due to factors such as pressure fluctuation, pipeline resistance and the like, so that the concentration of the mixed gas is inconsistent, and the combustion efficiency of the engine is affected. And the combustion conditions of the individual cylinders of the engine may also become uneven due to uneven fuel injection, which may lead to engine shake and noise. The amount of fuel sprayed out may be excessive, resulting in an excessive rich mixture, so that part of the fuel is not fully combusted, and fuel consumption is increased. And when the closing oil injection control piece is out of order or the oil nozzle coupling piece is blocked, the oil injection quantity of the oil injector sprayed into the combustion chamber of the cylinder is too large, so that the engine is easy to overheat and the piston is melted, and the engine is damaged.

Therefore, providing a flow-limiting device with stable flow-limiting effect for fuel injector is a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide a fuel injector flow limiting device which has a stable flow limiting effect.

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

the fuel injector flow limiting device comprises a valve body, a valve seat, a valve sleeve and a spring 1, wherein the valve body is of a hollow pipe sleeve structure and comprises a left oil inlet end and a right oil outlet end 1, the left oil inlet end and the right oil outlet end are arranged on one side of the oil outlet end, a first step and a second step are sequentially arranged in the valve body, the right side of the second step is provided with an oil outlet 1, the valve seat is fixedly arranged on one side of the oil inlet end, a first through hole is formed in the valve seat, and a flow limiting step is arranged in the first through hole; the valve seat and the valve body form a valve cavity for the valve sleeve to reciprocate; the right side of the valve sleeve is provided with a first counter bore, the left side of the spring is arranged in the first counter bore, and the right side of the spring is abutted with the second step; the outer wall of the valve sleeve is provided with an oil drain passage, one end of the oil drain passage is communicated with the first through hole, and the other end of the oil drain passage is communicated with the oil outlet through the valve cavity.

Further, the right end face of the valve sleeve corresponds to the first step, and under the driving of fuel flow pressure, the right end face of the valve sleeve and the first step form end face sealing.

Further, a second counter bore is formed in the left side of the valve sleeve, and the oil drain channel is communicated with the first through hole through the second counter bore.

Further, a plurality of oil leakage channels are symmetrically arranged on the outer wall of the valve sleeve.

Further, the oil drain passage comprises a first oil drain passage and a second oil drain passage which are communicated with each other; the first oil drain passage is arranged along the radial direction of the valve sleeve, and the second oil drain passage is arranged along the axial direction of the valve sleeve.

Further, the first oil drain passage is inclined in the axial direction of the valve sleeve, and the inclination of the first oil drain passage is 45-62 degrees.

Further, a notch is formed in the right end face of the outer wall of the valve sleeve.

Further, an expansion part is arranged on the left side of the first step in the valve body.

Compared with the prior art, the invention has the following beneficial effects: through the cooperation of the valve body, the valve sleeve and the spring, when the fuel flow of the fuel injector flow limiting device is normal, the fuel pressure in the fuel injector can be kept stable by the fuel injector flow limiting device, so that the fuel atomization effect is ensured, and the fuel combustion efficiency and the fuel combustion degree can be improved; when the high-pressure fuel flow is abnormal, the fuel can be prevented from flowing out of the valve body to enter the fuel injector after entering the fuel outlet. The fuel flow is limited by the fuel injector flow limiting device, so that the maximum injection flow of the fuel injector is controlled, and when the fault of the electric control fuel injector occurs and the fuel is directly communicated with the combustion chamber, the fuel supply to the fuel injector is cut off, and the occurrence or the amplification of accidents is prevented.

Drawings

FIG. 1 is a schematic cross-sectional view of a fuel injector flow restrictor of the present invention;

FIG. 2 is a schematic cross-sectional view of a fuel injector flow restrictor of the present invention when closed;

FIG. 3 is a schematic view of the valve housing of the present invention;

FIG. 4 is a schematic view of a cross-sectional structure of a valve housing according to the present invention 1

FIG. 5 is a schematic diagram of a scenario in which the fuel injector flow restrictor of the present invention is used.

Reference numerals illustrate: a valve body 100; a first step 1011 and a second step 102; an oil outlet 103; a valve chamber 104; a valve seat 200; a first through hole 201; a valve housing 300; a first counterbore 301; an oil drain passage 302; first drain 30211 second drain 30221 second counterbore 303; a spring 400; an injector body 600; a screen structure 700.

Detailed Description

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, unless otherwise specified and defined, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, mechanical or electrical, or may be in communication with each other between two elements, directly or indirectly through intermediaries, as would be understood by those skilled in the art, and the specific meaning of the terms may be understood as appropriate.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

As shown in fig. 1-5, the present application discloses a fuel injector flow restriction device comprising a valve body 100, a valve seat 200, a valve sleeve 300, and a spring 400; wherein the valve body 100 is in a hollow pipe sleeve structure and comprises an oil inlet end positioned at the left side and an oil outlet end positioned at the right side; on one side of the oil outlet end, a first step 101 and a second step 102 are sequentially arranged in the valve body 100, and an oil outlet 103 is arranged on the right side of the second step 102; the valve seat 200 is fixedly arranged at the oil inlet end, a first through hole 201 is arranged in the valve seat 200, and a flow limiting step is arranged in the first through hole 201; and the valve seat 200 and the valve body 100 form a valve cavity 104 for the reciprocating movement of the valve sleeve 300; the right side of the valve sleeve 300 is provided with a first counter bore 301, the left side of the spring 400 is arranged in the first counter bore 301, and the right side of the spring 400 is abutted with the second step 102; the outer wall of the valve sleeve 300 is provided with a drain passage 302, one end of the drain passage 302 is communicated with the first through hole 201, and the other end of the drain passage 302 is communicated with the oil outlet 103 through the valve cavity 104.

The fuel injector flow limiting device as described above, wherein the valve body 100 is made of stainless steel or carbon steel material to withstand the high pressure and high temperature working environment 1 of the fuel injector flow limiting device structure and the valve body 100 is of a hollow pipe sleeve structure, the left side end of which is used for fuel intake and the right side end of which is used for fuel discharge. A valve seat 200 is fixedly provided at an oil inlet end of the valve body 100, and in particular, the valve seat 200 may be fixed to an end of the valve body 100 by interference fit, and a first through hole 201 is further provided at the valve seat 200 for oil inlet. A flow limiting step is further disposed in the first through hole 201, specifically, two step surfaces are disposed in the first through hole 201, so that the inner diameter of the first through hole 201 gradually decreases toward a direction away from the oil inlet end. On the oil outlet side of the valve body 100, a first step 101 and a second step 102 are sequentially provided inside the valve body 100, so that the inner diameter of the valve body 100 gradually decreases toward a direction away from the oil inlet. A valve sleeve 300 is arranged in the valve body 100, and the valve sleeve 300 is in small clearance fit with the valve cavity 104; the valve body 100 and the valve seat 200 provided at the end of the valve body 100 form a valve chamber 104 in which the valve housing 300 is reciprocally movable left and right. The right side of the valve sleeve 300 is provided with a first counter bore 301, and the inner diameter of the first counter bore 301 is matched with the outer diameter of the spring 400, so that the end part of the spring 400 can be inserted into the first counter bore 301, and the right side of the spring 400 is abutted with a second step 102 arranged on one side of the oil outlet end of the valve body 100. The displacement of the spring 400 is limited through the cooperation of the first counter bore 301 and the second step 102, so that the spring 400 is prevented from falling off from the valve sleeve 300; and both ends of the spring 400 are not fixedly connected to maintain good elastic properties of the spring 400, and rapidly absorb and release energy. The outer wall of the valve housing 300 is provided with a drain passage 302, one end of the drain passage 302 communicates with the first through hole 201, and the other end of the drain passage 302 communicates with an oil outlet located on the right side of the valve body 100 through the valve chamber 104. When the fuel injector flow limiting device is assembled, firstly, the spring 400 is placed into the first counter bore 301 of the valve sleeve 300, then the valve sleeve 300 and the spring 400 are placed into the valve body 100, and the spring 400 is propped against the second step 102 so as to limit the positions of the spring 400 and the valve sleeve 300; finally, the valve seat 200 is interference-fitted at the oil inlet end of the valve body 100, and the first through hole 201 is communicated with the oil drain channel 302.

When the fuel flow of the fuel injector flow limiting device is normal, fuel enters the valve body 100 from the first through hole 201, and the fuel flows into the fuel drain passage 302 after flowing through the first through hole 201 due to the communication between the fuel drain passage 302 and the first through hole 201, and flows out of the valve body 100 from the oil outlet 103 after the fuel flow pressure is reduced due to the fact that the fuel drain passage 302 is the minimum flow aperture of the fuel in the fuel injector flow limiting device, and the fuel flows out of the valve body 100 from the valve cavity 104 after flowing through the fuel cavity 104, thereby participating in the follow-up work of the fuel injector. When the fuel flow is too large, the valve sleeve 200 is pushed to overcome the elasticity of the spring 400 and move towards the oil outlet direction in the valve cavity 104, so that the distance between the valve sleeve 300 and the first step 101 is reduced, namely, the fuel flow path from the valve cavity 104 to the oil outlet 103 is reduced, and excessive fuel is prevented from flowing out of the valve body 100 and entering the fuel injector, and the normal operation of the fuel injector is prevented from being influenced. When the fuel flow is normal, the fuel pressure in the fuel injector can be kept stable by the fuel injector flow limiting device, so that the fuel atomization effect is ensured, and the fuel combustion efficiency and the fuel combustion degree can be improved.

Further preferably, in other embodiments of the present application, the right end surface of the valve sleeve 300 corresponds to the first step 101, and the right end surface of the valve sleeve forms an end surface seal with the first step 101 under the driving of the fuel flow pressure. When the fuel injector works abnormally, namely the high-pressure fuel flow is large to be abnormal, the fuel flowing through the fuel injector flow limiting device enters the position of the fuel drain channel 301 in the fuel injector flow limiting device sleeve 300 from the first through hole 301 in the valve seat 200, and the fuel flow pressure is increased because the fuel drain channel 301 is the position of the minimum flow aperture of the fuel in the fuel injector flow limiting device, the fuel is indicated to be throttled at the position of the fuel drain channel 302, and the fuel flow is blocked. At this time, the fuel overcomes the spring force of the spring 400 by the oil pressure acting on the end of the valve sleeve 200, so as to quickly compress the spring 400, and under the action of the flowing oil pressure of the fuel, the valve sleeve 200 will move rightwards against the spring force, and the right end surface of the valve sleeve 200 contacts and fits with the first step 101 of the valve body 100, so as to form an end surface seal, and the fuel can be prevented from flowing out of the valve body 100 into the fuel injector after entering the oil outlet 103. The fuel flow is limited by the fuel injector flow limiting device, so that the maximum injection flow of the fuel injector is controlled, and when the fault of the electric control fuel injector occurs and the fuel is directly communicated with the combustion chamber, the fuel supply to the fuel injector is cut off, and the occurrence or the amplification of accidents is prevented.

Further preferably, in other embodiments of the present application, a second counterbore 303 is disposed on the left side of the valve sleeve 300, and the drain 302 is in communication with the first through hole 201 through the second counterbore 303. The second counterbore 303 is disposed at the center of the end of the valve housing 300 and is coaxial with the first through hole 201, and the drain passage 302 communicates with the first through hole 201 through the second counterbore 303. I.e., fuel enters the valve body 100 from the first through-hole 201, flows through the second counterbore 303 and then into the relief oil passage 302. Specifically, the second counterbore 303 is a blind hole machined from the right end surface of the valve sleeve 300 toward the interior of the valve sleeve 300, and because the blind hole is coaxially disposed with the first through hole 201, the fuel flows through the first through hole 201 and then directly flows into the second counterbore 303, and the fluid pressure of the fuel directly impacts the end surface of the second counterbore 303. When the fuel flows through the valve sleeve 300, and the same fuel flow flows through the end face of the second counter bore 303 with smaller area, the fuel impact force applied to the valve sleeve 300 is larger, namely the acting force of the valve sleeve 300 against the spring 400 is increased, the rightward displacement of the valve sleeve 300 is conveniently controlled, the opening of the fluid channel between the valve sleeve 300 and the first step 101 can be better controlled, and the fuel flow flowing out of the fuel injector flow limiting device can be more accurately controlled.

As further shown in fig. 5, in other embodiments of the present application, the outer wall of the valve sleeve 300 is symmetrically provided with a plurality of oil drainage channels 302. The oil drain channel 302 is disposed at the outer wall of the valve housing 300, and specifically, the oil drain channel 302 is formed by cutting a part of the outer wall of the cylindrical structural member along the axial direction, so as to circulate fuel. Through set up a plurality of oil drain ways 302 at valve pocket 300 outer wall, not only can increase the oil drain area for the fuel can more quick, more evenly discharge, and make and valve pocket 300 everywhere atress is even, guarantee that valve pocket 300 structure is more stable in the use, extension valve pocket 300's life, prolonged this sprayer current limiter's life promptly.

Further preferably, in other embodiments of the present application, the drain 302 includes a first drain 3021 and a second drain 3022 that are in communication with each other, where the first drain 3021 is disposed along a radial direction of the valve housing 300 and the second drain 3022 is disposed along an axial direction of the valve housing 300. The drain passage 302 is an oil passage provided at the outer wall of the valve housing 300, and specifically, the drain passage 302 is formed by cutting a portion of the outer wall of the valve housing 300 in a cylindrical shape in the axial direction. Through dividing the oil drain channel 302 into a first oil drain channel 3021 and a second oil drain channel 3022, wherein the first oil drain channel 3021 is a channel arranged along the radial direction of the valve sleeve 300, and the second oil drain channel 3022 is a channel arranged along the axial direction of the valve sleeve 300, so that when the oil drain channel 302 is machined by the structural component of the valve sleeve 300, the cutting tools can be used for machining the oil drain channel 302 in parallel along the radial direction of the end surface of the valve sleeve 300 and the axial direction of the side wall of the structural component, and compared with the integral oil drain channel 300, the machining difficulty of the split oil drain channel 302 is lower, the machining time is shortened, and the machining quality of the oil drain channel 302 is improved.

As shown in fig. 3, in other embodiments of the present application, the first drain 3021 is disposed at an inclination of 45 ° -62 ° along the axial direction of the valve housing 300. The first drain 3021 is arranged obliquely in the axial direction of the valve housing 300, i.e. the first drain 3021 is arranged in a slope shape, and the slope guides the fuel to flow to the second drain 3022. The slope-shaped first drain channel 3021 can better guide the fuel to flow to the second drain channel 3022, so that the fuel is not easy to accumulate at the first drain channel 3021, the fuel can flow more smoothly at the valve sleeve 300, and the working efficiency of the fuel injector flow limiting device is improved.

Further optimization, in other embodiments of the present application, a notch may optionally be provided at the outer wall of the right end face of the valve sleeve 300. When the fuel flow through the injector flow restrictor is excessive, the valve sleeve 300 will move to the right against the spring force and will cause the right end face of the valve sleeve 300 to form an end face seal against the first step 101 to isolate the fuel from the outlet 103. The sealing performance between the right end surface of the valve sleeve 300 and the first step 101 is determined by the flatness, roughness and other factors of the first step 101 and the right end surface. In order to ensure a good sealing effect, the right end face of the valve sleeve 300 and the first step 101 are required to be processed to be an absolute plane, and a notch is arranged at the outer wall of the right end face of the valve sleeve 300, so that the area of the right end face is reduced, namely, the processing difficulty of the right end face serving as the sealing plane is reduced, and the processing cost of the valve sleeve 300 and the fuel injector flow limiting device is reduced while the sealing effect is ensured.

Further preferably, in other embodiments of the present application, an enlarged portion is disposed in the valve body 100 at the left side of the first step 101. The enlarged portion is a cavity with an inner diameter larger than the length of the first step 101 and arranged on the left side of the first step 101. Since the first step 101 needs to be matched with the right end surface of the valve housing 300 to realize end surface sealing, it is a first factor to ensure the flatness of the first step 101 when the first step 101 is machined. By providing the enlarged portion on the left side of the first step 101, the operation is more convenient when the first step 101 is machined in the valve body 100, and the machining efficiency of the first step 101, that is, the machining efficiency of the fuel injector flow limiting device is improved.

The foregoing are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in any way, therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims

1. The fuel injector flow limiting device is characterized in that: comprises a valve body (100), a valve seat (200), a valve sleeve (300) and a spring (400); the valve body (100) is of a hollow pipe sleeve structure and comprises an oil inlet end positioned at the left side and an oil outlet end positioned at the right side; a first step (101) and a second step (102) are sequentially arranged in the valve body (100) at one side of the oil outlet end, and an oil outlet (103) is arranged at the right side of the second step (102); the valve seat (200) is fixedly arranged at the oil inlet end, a first through hole (201) is formed in the valve seat (200), and a flow limiting step is arranged in the first through hole (201); the valve seat (200) and the valve body (100) form a valve cavity (104) for the valve sleeve (300) to reciprocate; the right side of the valve sleeve (300) is provided with a first counter bore (301), the left side of the spring (400) is arranged in the first counter bore (301), and the right side of the spring (400) is abutted with the second step (102); the outer wall of the valve sleeve (300) is provided with an oil drain channel (302), one end of the oil drain channel (302) is communicated with the first through hole (201), and the other end of the oil drain channel (302) is communicated with the oil outlet (103) through the valve cavity (104).

2. The fuel injector flow restricting device of claim 1, wherein: the right end face of the valve sleeve (300) corresponds to the first step (103), and under the driving of fuel flow pressure, the right end face of the valve sleeve (300) and the first step (101) form end face sealing.

3. The fuel injector flow restricting device according to claim 1 or 2, characterized in that: a second counter bore (303) is formed in the left side of the valve sleeve (300), and the oil drain channel (302) is communicated with the first through hole (201) through the second counter bore (303).

4. The fuel injector flow restricting device according to claim 1 or 2, characterized in that: a plurality of oil discharge channels (302) are symmetrically arranged on the outer wall of the valve sleeve (300).

5. The fuel injector flow restricting device according to claim 1 or 2, characterized in that: the oil drain passage (302) comprises a first oil drain passage (3021) and a second oil drain passage (3022) which are communicated with each other; wherein the first drain passage (3021) is arranged along the radial direction of the valve housing (300), and the second drain passage (3022) is arranged along the axial direction of the valve housing (300).

6. A fuel injector flow restrictor according to claim 3, characterized in that: the oil drain passage (302) comprises a first oil drain passage (3021) and a second oil drain passage (3022) which are communicated with each other; wherein the first drain passage (3021) is arranged along the radial direction of the valve housing (300), and the second drain passage (3022) is arranged along the axial direction of the valve housing (300).

7. The fuel injector flow restricting device as claimed in claim 6, wherein the first drain passage (3021) is inclined in the axial direction of the valve housing (300) at an inclination of 45 ° -62 °.

8. A fuel injector flow restrictor according to claim 2, 6 or 7, the valve housing (300) being notched at the right end face outer wall.

9. The fuel injector flow restricting device of claim 1, 2, 5 or 7, wherein: an expansion part is arranged on the left side of the first step (101) in the valve body (100).

10. A fuel injector flow restrictor according to claim 3, characterized in that: an expansion part is arranged on the left side of the first step (101) in the valve body (100).