Tappet sleeve of large-flow electronic unit pump

Abstract

The invention relates to a tappet sleeve of a high-flow electric unit pump, which comprises a sleeve main body, a sleeve main body and a sleeve main body, the oil inlet ring groove is arranged around the outer circle of the sleeve main body, is positioned at one end, provided with the tappet body roller, of the sleeve main body, and is used for receiving pressure oil from a pump box lubricating oil inlet; the symmetrical oil inlet holes are two radial holes formed in the sleeve main body, one end of each radial hole is communicated with the oil inlet ring groove, and the other end of each radial hole is communicated with an annular gap formed between the sleeve main body and the tappet body; the oil drainage groove is formed below the radial hole in the axial direction of the sleeve body and used for communicating the annular gap with a cam shaft cavity in the lower portion of the sleeve body. Through the tappet sleeve, the lubricating mode and the lubricating structure of the tappet body assembly of the electronic unit pump are improved, and the effect of improving the reliability of the electronic unit pump is achieved.

Description

Technical Field

[0001] This application relates to the technical field of electronically controlled unit pump fuel injection systems, and in particular to a tappet sleeve for a high-flow electronically controlled unit pump. Background Technology

[0002] As engine performance continues to improve, higher demands are placed on the fuel supply pressure, injection rate, and maximum speed of the electronically controlled unit pump, thereby increasing the load on its moving parts. As a key moving component of the electronically controlled unit pump, the tappet assembly needs to withstand significant working stress, and its lubrication method directly affects the reliability of the pump.

[0003] Lubricating oil reaches the tappet assembly through the annular gap between the tappet body and the tappet sleeve, and the gap between the tappet sleeve and the pump housing. During the operation of the electronically controlled unit pump, it simultaneously lubricates the roller-cam motion pair and the outer surface of the tappet. In traditional inline pump fuel injection systems for diesel engines, the tappet assembly generally uses integral immersion pressure lubrication, where the lubricating oil fills the camshaft cavity. The tappet assembly is immersed in lubricating oil during operation, and the lubricating oil returns to the oil pan through a dedicated pipeline. This lubrication method may lead to insufficient or uneven lubricating oil flow. If the lubrication effect is poor, the elastic oil film on the surface of the parts is prone to rupture under high contact stress, causing direct metal-to-metal contact, resulting in wear and failure.

[0004] In view of this, this application aims to develop a tappet sleeve for a high-flow-rate electrically controlled unit pump, and to improve the lubrication method and lubrication structure of the tappet assembly of the electrically controlled unit pump through the tappet sleeve, so as to improve the reliability of the electrically controlled unit pump. Summary of the Invention

[0005] The technical problem to be solved by this application is that the tappet assembly of a certain type of electronically controlled unit pump in the prior art has insufficient lubricating oil and unreasonable lubricating oil distribution.

[0006] To solve the above-mentioned technical problems, this application provides a high-flow electronically controlled unit pump tappet sleeve, comprising: a sleeve body, which is a thin-walled cylinder with openings at the top and bottom; an oil inlet annular groove, which is arranged around the outer circumference of the sleeve body and is located at one end of the sleeve body where the tappet roller is installed, for receiving pressurized oil from the lubricating oil inlet of the pump box; symmetrical oil inlet holes, which are two radial holes opened on the sleeve body, one end of the radial holes is connected to the oil inlet annular groove, and the other end is connected to the annular gap formed between the sleeve body and the tappet; and an oil drain groove, which is opened below the radial holes and along the axial direction of the sleeve body, for connecting the annular gap and the camshaft cavity at the bottom of the sleeve body.

[0007] The pressurized lubricating oil from the pump box first enters the oil inlet annular groove on the outer circumference of the sleeve body. The oil in the oil inlet annular groove is directly sprayed into the annular gap between the tappet and the sleeve body through two symmetrical radial holes. The oil entering the annular gap flows downward under the influence of gravity and the movement of the tappet. It is guided to the contact area between the roller and the camshaft at the bottom of the tappet through the oil drain groove at the bottom of the sleeve body. After lubrication, the oil finally collects in the camshaft cavity and flows back to the lubricating oil system through the return oil channel of the pump box, thus achieving recycling.

[0008] According to an embodiment of this application, the sleeve body is further provided with a cylindrical surface that precisely matches the outer circle of the tappet, serving as an inner hole guide surface to provide a flow gap for lubricating oil.

[0009] According to an embodiment of this application, the tappet is assembled inside the sleeve body, and the tappet moves axially within the sleeve body.

[0010] According to an embodiment of this application, the oil drain groove is an axial groove.

[0011] According to an embodiment of this application, a roller is installed at one end of the tappet, and the roller is installed at the lower end of the tappet via a tappet pin. The outer contour of the roller does not exceed the surface of the tappet.

[0012] According to an embodiment of this application, the outer cylindrical surface of the roller is in linear contact with the working surface of the cam, forming a roller-cam kinematic pair.

[0013] According to an embodiment of this application, the tappet sleeve is installed inside the pump housing, and the lubricating oil inlet of the pump housing is connected to the oil inlet ring groove.

[0014] According to an embodiment of this application, the oil enters the fitting gap between the tappet and the sleeve body through two radial oil inlets of the sleeve body, forming a 360° oil film on the outer periphery of the tappet.

[0015] According to an embodiment of this application, the tappet sleeve is made of 18CrNiMo7-6 material by carburizing and quenching, and the surface coating is DLC and TiN.

[0016] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0017] 1. Compared with the prior art, this application changes the lubrication method of the tappet assembly to a combination of annular gap leakage and oil drain groove injection, aiming to optimize the distribution of lubricating oil and increase the flow rate of lubricating oil. The oil in the oil inlet annular groove is directly sprayed into the mating gap between the tappet and the tappet sleeve through two symmetrical oil inlet holes. When the tappet reciprocates, a continuous oil film is formed, which increases the amount of lateral lubricating oil on the outer circle of the tappet, makes the distribution of lubricating oil more conducive to relieving lateral friction, and enhances the lateral lubrication effect on the outer circle. The part of the oil entering the mating gap flows downward under the action of gravity and the movement of the tappet, and is guided to the contact area between the roller and the camshaft at the bottom of the tappet through the oil drain groove at the bottom of the tappet sleeve. The purpose of adding the oil drain groove is to increase the amount of lubricating oil on the contact surface of the roller and the cam, providing sufficient lubrication for the high-speed roller-cam kinematic pair.

[0018] 2. This application improves the lubrication method of the tappet assembly, which significantly increases the fatigue life of the tappet assembly, meets the 100-hour full-speed, full-load test requirements of a certain type of diesel engine electronically controlled unit pump, increases the reliability of the electronically controlled unit pump, and has a positive significance for improving the reliability of the electronically controlled unit pump. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this application, and are not intended to limit this application.

[0020] Figure 1 This is a schematic diagram of the lubrication structure of the original tappet and tappet sleeve in the prior art, as exemplified by the present invention.

[0021] Figure 2 This is a schematic diagram of the improved lubrication structure of the tappet and tappet sleeve as an example of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of a high-flow-rate electrically controlled single-unit pump tappet sleeve, as exemplified by the present invention.

[0023] The annotations in the attached figures are explained as follows:

[0024] 11. Oil inlet ring groove, 12. Tappet, 13. Roller, 20. Pump box, 30. Sleeve body, 31. Radial hole, 32. Oil drain groove, 40. Camshaft cavity. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the described embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a,” and similar terms, do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0027] according to Figure 2 and Figure 3 As shown, this application exemplifies a high-flow-rate electrically controlled unit pump tappet sleeve, including a sleeve body 30 and an oil inlet annular groove 11, symmetrical oil inlet holes, and an oil drain groove 32 provided on the sleeve body 30. This application achieves this by minimizing modifications to the pump housing structure of the electrically controlled unit pump. Figure 1 Based on the existing structure, the lubrication structure of the tappet 12 assembly has been improved. To enhance the lateral lubrication effect on the outer circle of the tappet 12, an oil inlet hole is added at a symmetrical position on the tappet sleeve. To enhance the lubrication effect of the roller-cam motion pair, an oil drain groove 32 is added below the oil inlet hole of each tappet sleeve. By focusing on the tappet sleeve, the lubrication method and lubrication structure of the tappet 12 assembly of the electronically controlled unit pump are improved, thereby achieving the effect of improving the reliability of the electronically controlled unit pump.

[0028] In this embodiment, as Figure 3 As shown, a high-flow electrically controlled single pump tappet sleeve includes a sleeve body 30, which is a thin-walled cylinder with openings at the top and bottom.

[0029] Specifically, the tappet 12 is assembled inside the sleeve body 30, and the tappet 12 moves axially within the sleeve body 30. A roller 13 is installed at one end of the tappet 12, and the roller 13 is installed at the lower end of the tappet 12 through a tappet pin. The outer contour of the roller 13 does not exceed the surface of the tappet 12, and the outer circular surface of the roller 13 is in linear contact with the working surface of the cam, forming a roller-cam kinematic pair.

[0030] Specifically, the sleeve body 30 is also provided with a cylindrical surface that precisely matches the outer circle of the tappet 12, serving as an inner hole guide surface to provide a flow gap for lubricating oil.

[0031] Specifically, the tappet sleeve can be made of 18CrNiMo7-6 material by carburizing and quenching, and the surface coating is DLC and TiN.

[0032] In this embodiment, the oil inlet annular groove 11 is arranged around the outer circle of the sleeve body 30. The oil inlet annular groove 11 is located at one end of the sleeve body 30 where the tappet roller 13 is installed, and is used to receive the pressure oil from the lubricating oil inlet of the pump box 20.

[0033] Specifically, the tappet sleeve is installed inside the pump housing 20. The lubricating oil inlet of the pump housing 20 is connected to the inlet annular groove 11. The annular inlet annular groove 11, located on the upper part of the outer circle of the tappet sleeve, is used to receive the pressurized oil from the lubricating oil inlet of the pump housing 20. The pressurized lubricating oil enters from the lubricating oil inlet of the pump housing 20 and is directly injected into the inlet annular groove 11 on the outer circle of the tappet sleeve. The annular structure of the inlet annular groove 11 allows the oil to be evenly distributed around the outer circle of the tappet sleeve, providing a stable oil source for the two symmetrically arranged oil inlets and achieving circumferentially distributed oil supply.

[0034] In this embodiment, as Figure 2 As shown, the symmetrical oil inlet holes are two radial holes 31 opened on the sleeve body 30. One end of the radial hole 31 is connected to the oil inlet annular groove 11, and the other end is connected to the annular gap formed between the sleeve body 30 and the tappet 12, providing lateral lubrication for the mating surface of the tappet 12 and the tappet sleeve.

[0035] Specifically, the oil enters the mating gap between the tappet 12 and the sleeve body 30 through the two radial oil inlets of the sleeve body 30, forming a 360° oil film on the outer periphery of the tappet 12 to lubricate the mating surface.

[0036] An oil drain groove 32 is provided below the radial hole 31 and along the axial direction of the sleeve body 30. The oil drain groove 32 is used to connect the annular gap with the lower camshaft cavity 40 of the sleeve body 30.

[0037] Specifically, the oil drain groove 32 is an axial groove. Part of the oil entering the annular gap remains in the gap to maintain lateral lubrication, while the other part flows downward under the influence of gravity and the movement of the tappet 12. The downward-flowing oil is precisely guided through the oil drain groove 32 at the bottom of the tappet sleeve to the contact area between the roller 13 at the bottom of the tappet 12 and the camshaft. The oil forms an oil film on the roller-cam contact surface, reducing wear and friction and ensuring reliable operation of the moving parts.

[0038] Specifically, the pressure lubricating oil in the pump box 20 first enters the oil inlet annular groove 11 on the outer circumference of the sleeve body 30. The oil in the oil inlet annular groove 11 is directly sprayed into the annular gap between the tappet 12 and the sleeve body 30 through two symmetrical radial holes 31. The oil entering the annular gap flows downward under the influence of gravity and the movement of the tappet 12. It is guided to the contact area between the roller 13 at the bottom of the tappet 12 and the camshaft through the oil drain groove 32 at the bottom of the sleeve body 30. After lubrication, the oil finally collects in the camshaft cavity 40 and flows back to the lubricating oil system through the return oil channel of the pump box 20, realizing recycling.

[0039] In this embodiment, a lubrication structure for the engagement of a high-flow electrically controlled single-unit pump tappet sleeve and tappet body 12 assembly achieves precise lubrication of the tappet body assembly through the following path: 1) Oil supply start-up: Pressurized lubricating oil enters from the lubricating oil inlet of the pump housing 20 and is directly injected into the oil inlet annular groove 11 on the outer circumference of the tappet sleeve; 2) Circumferential uniform distribution: The annular structure of the oil inlet annular groove 11 allows the oil to be evenly distributed circumferentially on the outer circumference of the tappet sleeve, providing a stable oil source for the two symmetrically arranged oil inlets; 3) Lateral lubrication supply: The oil enters the mating gap between the tappet body 12 and the tappet sleeve through the two radial oil inlets of the tappet sleeve, forming an oil film during the reciprocating motion of the tappet body 12 to lubricate the mating surface; 4) Oil diversion: Part of the oil entering the mating gap remains in the gap to maintain lateral lubrication, while the other part flows downward under the influence of gravity and the movement of the tappet body 12; 5) Guiding to rollers - Cam pair: The downward flowing oil is precisely guided through the oil drain groove 32 at the bottom of the tappet sleeve to the contact area between the roller 13 at the bottom of the tappet body 12 and the camshaft; 6) Lubrication of the kinematic pair: The oil forms an oil film on the roller-cam contact surface, reducing wear and friction and ensuring reliable operation of the kinematic pair; 7) Oil return circulation: The lubricated oil collects in the camshaft cavity 40 and flows back to the lubricating oil system through the lubricating oil return channel of the pump box 20 to enter the next cycle.

[0040] In summary, the technical solution of this application has the following beneficial effects:

[0041] 1. Compared with the prior art, this application changes the lubrication method of the tappet assembly to a combination of annular gap leakage and oil drain groove injection, aiming to optimize the distribution of lubricating oil and increase the flow rate of lubricating oil. The oil in the oil inlet annular groove is directly sprayed into the mating gap between the tappet and the tappet sleeve through two symmetrical oil inlet holes. When the tappet reciprocates, a continuous oil film is formed, which increases the amount of lateral lubricating oil on the outer circle of the tappet and makes the distribution of lubricating oil more conducive to relieving lateral friction, thus enhancing the lateral lubrication effect on the outer circle. The part of the oil entering the mating gap flows downward under the influence of gravity and the movement of the tappet, and is guided to the contact area between the roller and the camshaft at the bottom of the tappet through the oil drain groove at the bottom of the tappet sleeve. The purpose of adding the oil drain groove is to increase the amount of lubricating oil on the contact surface between the roller and the cam, providing sufficient lubrication for the high-speed roller-cam kinematic pair.

[0042] 2. This application improves the lubrication method of the tappet assembly, which significantly increases the fatigue life of the tappet assembly, meets the 100-hour full-speed, full-load test requirements of a certain type of diesel engine electronically controlled unit pump, increases the reliability of the electronically controlled unit pump, and has a positive significance for improving the reliability of the electronically controlled unit pump.

[0043] The above are merely exemplary embodiments of this application and are not intended to limit the scope of protection of this application, which is determined by the appended claims.

Claims

1. A tappet sleeve for a high-flow-rate electrically controlled single-unit pump, characterized in that, include: The main body is a thin-walled cylinder with openings at the top and bottom; An oil inlet annular groove is provided around the outer circle of the sleeve body. The oil inlet annular groove is located at the end of the sleeve body where the tappet roller is installed, and is used to receive pressurized oil from the lubricating oil inlet of the pump box. Symmetrical oil inlet holes are two radial holes opened on the sleeve body. One end of the radial hole is connected to the oil inlet annular groove, and the other end is connected to the annular gap formed between the sleeve body and the tappet. An oil drain groove is provided below the radial hole and along the axial direction of the sleeve body. The oil drain groove is used to connect the annular gap with the camshaft cavity at the lower part of the sleeve body. In this process, the pressurized lubricating oil from the pump box first enters the oil inlet annular groove on the outer circumference of the sleeve body. The oil in the oil inlet annular groove is directly sprayed into the annular gap between the tappet and the sleeve body through two symmetrical radial holes. The portion of the oil entering the annular gap flows downward under the influence of gravity and the movement of the tappet, and is guided to the contact area between the roller and the camshaft at the bottom of the tappet through the oil drain groove at the bottom of the sleeve body. After lubrication, the oil finally collects in the camshaft cavity and flows back to the lubricating oil system through the return oil channel of the pump box, thus achieving recycling.

2. The tappet sleeve for a high-flow electrically controlled single-unit pump according to claim 1, characterized in that, The main body of the sleeve is also provided with a cylindrical surface that precisely matches the outer circle of the tappet, serving as an inner hole guide surface to provide a flow gap for lubricating oil.

3. The tappet sleeve for a high-flow electrically controlled single-unit pump according to claim 1, characterized in that, The tappet is assembled inside the sleeve body, and the tappet moves axially within the sleeve body.

4. The tappet sleeve for a high-flow electrically controlled single-unit pump according to claim 1, characterized in that, The oil drain groove is an axial groove.

5. The tappet sleeve for a high-flow electrically controlled single-unit pump according to claim 1, characterized in that, The roller is installed at one end of the tappet, and the roller is installed at the lower end of the tappet via a tappet pin. The outer contour of the roller does not exceed the surface of the tappet.

6. The tappet sleeve for a high-flow electrically controlled single-unit pump according to claim 1, characterized in that, The outer circular surface of the roller is in linear contact with the working surface of the cam, forming a roller-cam kinematic pair.

7. The tappet sleeve for a high-flow electrically controlled single-unit pump according to claim 1, characterized in that, The tappet sleeve is installed inside the pump housing, and the lubricating oil inlet of the pump housing is connected to the oil inlet ring groove.

8. The tappet sleeve for a high-flow electrically controlled single-unit pump according to claim 1, characterized in that, The oil enters the fitting gap between the tappet and the sleeve body through the two radial oil inlets of the sleeve body, forming a 360° oil film on the outer periphery of the tappet.

9. The tappet sleeve for a high-flow electrically controlled single-unit pump according to claim 1, characterized in that, The tappet sleeve is made of 18CrNiMo7-6 material by carburizing and quenching, and the surface coating is DLC and TiN.

Images