WO2021134484A1

WO2021134484A1 - Hydraulic lash adjuster for valve mechanism

Info

Publication number: WO2021134484A1
Application number: PCT/CN2019/130519
Authority: WO
Inventors: 朱峰
Original assignee: 舍弗勒技术股份两合公司
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2021-07-08

Abstract

A hydraulic lash adjuster for a valve mechanism. The hydraulic lash adjuster comprises a cylindrical housing (1) and a plunger (2). The housing (1) has a closed end (11) and an open end (12). A first end (24) of the plunger (2) is inserted axially into the housing (1) from the open end (12). The plunger (2) has a hollow inner cavity (21). The inner cavity (21) has an inwardly and radially constricted neck (26) at the axial middle and an oil hole (23) running through the side wall of the neck. The end of the neck (26) axially facing the closed end (11) forms a first protrusion (22). The hydraulic lash adjuster further comprises a sleeve (3) and a sleeve spring (7) installed in the inner cavity (21). The sleeve (3) has an inwardly and radially constricted second protrusion (31) at the axial middle. The sleeve (3) is installed in an axially slidable manner in the inner cavity (21) between the first protrusion (22) and the first end (24) and can be axially stopped by the cooperation of the first protrusion (22) and the second protrusion (31). The oil hole (23) opens into the inner cavity (21) at the first protrusion (22), and the sleeve spring (7) axially abuts between the first end (24) and the sleeve (3). The hydraulic lash adjuster can effectively improve the oil storage amount in the plunger (2).

Description

Hydraulic lash adjuster for valve train

Technical field

The invention relates to the technical field of engines. Specifically, the present invention relates to a hydraulic lash adjuster for a valve train.

Background technique

In the internal combustion engine of a motor vehicle, a rocker arm for pushing a valve stem to control the opening and closing of the valve is usually provided. The rocker arm generally swings with a hydraulic lash adjuster as a fulcrum under the drive of a cam, and the hydraulic lash adjuster automatically adjusts the gap between the cam and the rocker arm through the telescopic movement of its plunger in the housing. A typical hydraulic lash adjuster structure can be found in CN 109386334 A, for example. In such a typical structure, a low-pressure chamber for storing liquid is formed in the plunger cavity, a high-pressure chamber for storing liquid is formed between the bottom of the plunger and the bottom of the housing, and the low-pressure chamber and the high-pressure chamber are communicated with each other through a one-way valve. This allows liquid to flow from the low-pressure chamber into the high-pressure chamber. An oil supply hole is formed on the side wall of the plunger, and oil can be supplied to the low pressure chamber in the inner cavity of the plunger through the oil supply hole. When the engine is just started, if the amount of oil in the low-pressure chamber is insufficient, and there is not enough liquid in the low-pressure chamber to supplement the high-pressure chamber, noise may be caused. However, in some internal combustion engines, the hydraulic lash adjuster is often placed obliquely, which causes the liquid in the low pressure chamber to flow out of the oil hole on the side wall of the plunger, thereby reducing the amount of liquid in the low pressure chamber.

There are many existing technologies dedicated to solving the above-mentioned problems. For example, US 5979377 A discloses a hydraulic lash adjuster, which installs an elongated sleeve in the plunger cavity, the oil hole opens to the sleeve and the inner wall of the plunger to form an annular space, and the liquid inside the sleeve Only the space at the top of the sleeve can flow into the annular space communicating with the oil hole, so the liquid inside the sleeve is unlikely to leak from the oil hole when it is inclined. However, the processing technology of such a sleeve is complicated, and it is necessary to turn a boss in the plunger to install the sleeve, which greatly increases the production cost.

Summary of the invention

Therefore, the technical problem to be solved by the present invention is to provide a hydraulic lash adjuster that can increase the oil storage in the plunger.

The above technical problem is solved by a hydraulic lash adjuster for a valve train according to the present invention. The hydraulic lash adjuster includes a cylindrical housing and a plunger. The housing has a closed end and an open end. The first end of the plunger is inserted into the housing from the open end in the axial direction. The plunger has a hollow inner cavity. The inner cavity has a neck that narrows inward and radially in the middle of the axial direction and an oil hole penetrating through the side wall of the inner cavity. The end of the neck that faces the closed end in the axial direction forms a first boss portion; wherein, the hydraulic The lash adjuster also includes a sleeve installed in the inner cavity and a sleeve spring. The sleeve has a second boss portion that narrows inward and radially in the middle of the axial direction. The sleeve is located between the first boss portion and the first end. The oil hole is axially slidably installed in the cavity and can be axially stopped by the cooperation of the first boss portion and the second boss portion. The oil hole opens into the cavity at the first boss portion, And the sleeve spring abuts between the first end and the sleeve in the axial direction. The sleeve can slide axially under the combined action of the elastic force of the sleeve spring and the liquid pressure from the oil hole, so that the second boss The part can close or open the oil hole. When no liquid flows to the inner cavity through the oil hole, the elastic force of the sleeve spring can keep the first boss portion and the second boss portion in contact, thereby closing the oil hole and preventing the liquid in the inner cavity from flowing out of the oil hole; When there is liquid flowing to the inner cavity through the oil hole, the liquid pressure generated on the second boss portion can overcome the elastic force of the sleeve spring and push the sleeve toward the first end, thereby opening the oil hole so that the liquid can flow from the oil. The hole enters the inner cavity. In this design, the cooperation of the sleeve and the sleeve spring can automatically open or close the oil hole according to whether there is liquid in the oil hole. During the engine start phase, since no liquid flows into the inner cavity, the sleeve automatically closes the oil hole, so that the liquid in the inner cavity cannot flow out through the oil hole, thereby ensuring sufficient oil storage in the inner cavity and preventing noise. When the engine is running normally, because liquid flows in from the oil hole, the liquid will contact the second boss portion and generate liquid pressure on it. The second boss portion is a transitional section formed by the narrowing of the sleeve diameter. Extending at least partly in the radial direction, the liquid pressure generated on the surface of the second boss part will have at least part of the axial component; the parameters of the sleeve spring are appropriately selected so that the pressure acting on the second boss part at this time The liquid pressure is sufficient to overcome the elastic force of the sleeve spring to push the sleeve to move toward the first end, thereby opening the oil hole, so that the liquid can flow into the inner cavity.

According to a preferred embodiment of the present invention, the extension direction of the oil hole can be inclined from the outside to the inside toward the first end with respect to the radial direction, so that the liquid pressure acting on the second boss portion has a larger axial component, It is convenient to push the sleeve to move axially when liquid flows into the oil hole.

According to another preferred embodiment of the present invention, the axial end of the sleeve spring can abut on the sleeve at the radial inner side of the second boss portion, thereby utilizing the structure that the second boss portion narrows inwardly As the engagement surface of the sleeve spring. Further preferably, the hydraulic lash adjuster may further include an end cover ring, through which the axial end of the sleeve spring can abut the sleeve, so as to prevent the axial end of the sleeve spring from sliding into the sleeve. In the narrower section of the barrel.

According to another preferred embodiment of the present invention, the first boss portion and the second boss portion may have corresponding shapes, so that the two can be attached to each other. This allows the second boss portion to better seal the oil hole when no liquid flows into the oil hole, thereby effectively preventing the liquid in the inner cavity from leaking to the outside through the oil hole.

According to another preferred embodiment of the present invention, when viewed in a longitudinal section, the first boss portion and the second boss portion may have arc-shaped surface profiles. In the prior art, the neck is usually formed by stamping. The first boss portion is generally a circular arc as the transition edge of the neck. Therefore, the second boss is also formed in a corresponding arc. It is not only conducive to the mutual adhesion of the two, but also can reduce the impact of sliding contact. However, as long as the liquid pressure acting on the second boss portion can have an axial component, other shapes such as a straight surface extending radially or obliquely are also possible.

According to another preferred embodiment of the present invention, the sleeve may have a first section adjacent to the second boss portion and extending toward the first end. The first section is straight cylindrical and can follow the inner surface of the inner cavity. slide. This means that the diameter of the straight cylindrical first section can be close to and slightly smaller than the diameter of the corresponding inner cavity section (the section adjacent to the first boss portion and extending toward the closed end), so that the outer portion of the first section The surface can roughly fit the inner surface of the inner cavity, thereby guiding the sleeve to slide in the inner cavity. Similarly, the sleeve may also have a second section adjacent to the second boss portion and extending away from the first end. The second section is straight cylindrical and can slide along the inner surface of the inner cavity. Likewise, this means that the diameter of the second section of the straight cylindrical shape can be close to and slightly smaller than the diameter of the corresponding inner cavity section (the section adjacent to the first boss portion and extending toward the open end), so that the second section The outer surface of the inner cavity can also roughly fit the inner surface of the inner cavity, thereby guiding the sleeve to slide in the inner cavity.

According to another preferred embodiment of the present invention, the plunger may have a plurality of oil holes distributed at intervals along the circumferential direction. This is beneficial to increase the liquid flow into the inner cavity and increase the liquid pressure acting on the second boss portion. In addition, preferably, the oil holes can be evenly distributed along the circumferential direction, so that the second boss portion receives uniform force in the circumferential direction.

Description of the drawings

The present invention will be further described below in conjunction with the drawings. In the figures, the same reference numerals are used to represent elements with the same function. among them:

Figure 1 shows an axial cross-sectional view of a hydraulic lash adjuster according to an embodiment of the present invention;

Figure 2 shows a perspective view of a sleeve of a hydraulic lash adjuster according to an embodiment of the present invention;

Fig. 3 shows a perspective view of an end cover ring of a hydraulic lash adjuster according to an embodiment of the present invention;

Figure 4 shows a detailed schematic diagram of the hydraulic lash adjuster according to an embodiment of the present invention when no liquid enters; and

Fig. 5 shows a detailed schematic diagram of the hydraulic lash adjuster according to an embodiment of the present invention when liquid enters.

Detailed ways

The specific embodiments of the hydraulic lash adjuster according to the present invention will be described below with reference to the accompanying drawings. The following detailed description and drawings are used to exemplarily illustrate the principle of the present invention. The present invention is not limited to the described preferred embodiments, and the protection scope of the present invention is defined by the claims.

According to an embodiment of the present invention, there is provided a hydraulic lash adjuster for a valve train of an internal combustion engine. Fig. 1 shows an axial cross-sectional view of a hydraulic lash adjuster according to an embodiment of the present invention. As shown in FIG. 1, the hydraulic lash adjuster includes a housing 1 and a plunger 2. The housing 1 is cylindrical, one end of which is a closed end 11 in the axial direction, and the other end is an open end 12. The plunger 2 is also substantially cylindrical and has a substantially cylindrical hollow inner cavity 21. The first end 24 of the plunger 2 is axially inserted into the housing 1 from the open end 12 of the housing 1, and the second end 25 opposite to the first end 24 in the axial direction is located outside the housing 1. The plunger 2 may include an upper plunger and a lower plunger, wherein the first end 24 is the lower end of the lower plunger, the second end 25 is the upper end of the upper plunger, and the inner cavity 21 is formed by the upper plunger and the lower plunger. Space formation. A high-pressure chamber 4 for storing liquid is formed between the first end 24 of the plunger 2 and the closed end 11 of the housing 1, and the inner cavity 21 of the plunger 2 constitutes a low-pressure chamber for storing liquid. The high-pressure chamber 4 communicates with the inner cavity 21 through a hole on the first end 24 where the one-way valve 6 is installed. The one-way valve 6 only allows liquid to flow from the inner cavity 21 into the high-pressure chamber 4, and does not allow the liquid to flow in the opposite direction. The valve spring 5 abuts between the first end 24 of the plunger 2 and the closed end 11 of the housing 1 in the axial direction. The plunger 2 can slide axially in the housing 1 under the combined action of the elastic force of the valve spring 5 and the liquid pressure.

A radially penetrating oil hole 13 is formed in the middle of the side wall of the housing 1, and a ring groove 14 is formed on the inner side of the side wall at a position corresponding to the oil hole 13. The plunger 2 has an inwardly narrowed neck 26 formed by rolling in the middle of the axial direction. The neck 26 also forms a ring groove on the outside of the side wall of the plunger 2, and the ring groove corresponds to the ring groove 14 of the housing 1. Ground installation, and a clamp ring 9 is installed between the two, so that the sliding range of the plunger 2 relative to the housing 1 can be limited by the cooperation of the clamp ring 9 and the two ring grooves. The axial end of the neck 26 facing the first end 24 on the radially inner side constitutes the first boss portion 22, and the adjacent inner cavity section above the first boss portion 22 (that is, adjacent to the first boss portion 22 and back The section extending to the first end 24) and the adjacent inner cavity section below (that is, the section adjacent to the first boss portion 22 and extending toward the first end 24) are respectively formed in a straight cylindrical shape, that is, each has a uniform shape. The diameter of the upper section is smaller than the diameter of the lower section. When viewed in a longitudinal section (that is, a section passing through the central axis), the first boss portion 22 has an arc-shaped profile, thereby forming a transition area between the upper section and the lower section thereof. One or more oil holes 23 evenly distributed in the circumferential direction are formed at the neck 26, and each oil hole 23 extends obliquely from the outside to the inside toward the first end 24, so that the oil hole 23 is at the first boss portion 22 Pass into the cavity 21.

The hydraulic lash adjuster also includes a sleeve 3 and a sleeve spring 7 installed in the inner cavity 21. FIG. 2 shows a perspective view of the sleeve 3. As shown in FIG. 2, the sleeve 3 is a cylindrical structure without an end wall, and has a first section 32 and a second section 33 that are straight cylindrical. As shown in FIG. 4, the diameter of the first section 32 is close to and slightly smaller than the diameter of the adjacent cavity section below the first boss portion 22, and the diameter of the second section 33 is close to and slightly smaller than the diameter of the first boss portion 22 The diameter of the upper section adjacent to the inner cavity allows the first section 32 and the second section 33 to roughly fit the inner surface of the inner cavity 21 on both sides of the first boss portion 22, so as to smoothly guide the sleeve 3 Sliding in the cavity 21. The transition section between the first section 32 and the second section 33 forms a second boss portion 31, which axially stops the sleeve 3 through the cooperation of the second boss portion 31 and the first boss portion 22 Sliding makes it impossible for the sleeve 3 to slide over the neck 26 and into the section above the neck 26 close to the second end 25. The second boss portion 31 has a circular arc profile corresponding to the first boss portion 22, so that the two can be closely attached. The sleeve spring 7 abuts between the first end 24 and the sleeve 3 in the axial direction, and its axial end abutting the sleeve 3 engages at the radially inner side of the second boss portion 31. In order to prevent the axial end of the sleeve spring 7 from sliding into the second section 33 along the inner side of the arc-shaped second boss portion 31, it may be between the axial end of the sleeve spring 7 and the sleeve 3 The end cover ring 8 is installed, and the sleeve spring 7 abuts on the sleeve 3 through the end cover ring 8. The structure of the end cover ring 8 is shown in FIG. 3, and its end surface has a large through hole to allow liquid to flow through.

4 and 5 respectively show detailed schematic diagrams of the hydraulic lash adjuster according to an embodiment of the present invention with and without liquid inflow in the oil hole 13. In the state shown in FIG. 4, no liquid from the oil hole 13 flows to the inner cavity 21 through the oil hole 23, and the sleeve 3 abuts the lower end of the neck 26 upward under the elastic force of the sleeve spring 7, so that the second The boss portion 31 is attached to the first boss portion 22, so that the outlet of the oil hole 23 formed on the first boss portion 22 is closed by the second boss portion 31. At this time, the liquid in the inner cavity 21 cannot leak to the outside through the oil hole 23, so even when the hydraulic lash adjuster is installed obliquely, the oil storage in the inner cavity 21 can be guaranteed, which is beneficial to reduce noise during the engine start phase. . In the state shown in FIG. 5, the liquid from the oil hole 13 flows to the inner cavity 21 through the oil hole 23, and the liquid pressure generated by the liquid on the surface of the second boss portion 31 has an axial direction toward the first end 24 Under the action of this component, the sleeve 3 overcomes the elastic force of the sleeve spring 7 and slides toward the first end 24, thereby opening the oil hole 23 so that the liquid from the oil hole 13 can enter the inner cavity 21 through the oil hole 23 , In order to supplement the oil storage in the cavity 21. For this reason, it is necessary to select the parameters of the sleeve spring 7 according to the amount of liquid pressure that the liquid in the oil hole 23 can generate on the second boss portion 31, so that when liquid flows into the oil hole 23, it can easily overcome the sleeve spring. The elastic force of the spring 7 pushes the sleeve 3.

Except for the extension direction of the oil hole 23, the structure of the plunger 2 is consistent with the prior art, which means that there is basically no need to change the plunger structure of the prior art, just by adding the sleeve 3 and the sleeve spring 7. Good oil storage effect can be obtained. Therefore, the hydraulic lash adjuster of the present invention is easy to manufacture and has low cost. However, it should be understood that under the premise that the sleeve 3 can open or close the oil hole 23 according to whether there is liquid inflow, the above-mentioned structural details can also be adjusted, such as the contours of the first boss portion 22 and the second boss portion 31 It may also be formed as a straight line extending obliquely or radially, or the first boss portion 22 and the second boss portion 31 may have different contours and not fit completely, and such changes are all included in the scope of the present invention.

Although possible embodiments are exemplarily described in the above description, it should be understood that there are still a large number of embodiment variations through all known and otherwise easily conceivable technical features and implementation combinations. In addition, it should be understood that the exemplary embodiment is only taken as an example, and this embodiment does not limit the protection scope, application, and configuration of the present invention in any form. Through the foregoing description, it is more to provide technical guidance for the technical personnel to transform at least one exemplary embodiment, in which various changes can be made as long as they do not deviate from the protection scope of the claims, especially regarding the Changes in the function and structure of components.

Reference number table

1 Shell

11 Closed end

12 Open end

13 Oil hole

14 Ring groove

2 Plunger

21 Inner cavity

22 The first boss

23 Oil hole

24 The first end

25 The second end

26 Neck

3 Sleeve

31 The second boss

32 The first segment

33 The second segment

4 High-pressure room

5 Valve spring

6 Check valve

7 Sleeve spring

8 End cover ring

9 Card ring

Claims

A hydraulic lash adjuster for a valve mechanism includes a cylindrical housing (1) and a plunger (2). The housing (1) has a closed end (11) and an open end (12). The first end (24) of the plunger (2) is axially inserted into the housing (1) from the open end (12), and the plunger (2) has a hollow inner cavity (21), The inner cavity (21) has a neck (26) that narrows radially inwardly and an oil hole (23) penetrating through the side wall of the inner cavity (21) in the middle of the axial direction. The end of the closed end (11) forms a first boss portion (22),

It is characterized by

The hydraulic lash adjuster also includes a sleeve (3) and a sleeve spring (7) installed in the inner cavity (21), and the sleeve (3) has a radially narrowing inward in the middle of the axial direction. The second boss portion (31), the sleeve (3) is axially slidably installed in the inner cavity (3) between the first boss portion (22) and the first end (24) 21) and can be axially stopped by the cooperation of the first boss portion (22) and the second boss portion (31), the oil hole (23) is in the first boss The part (23) opens into the inner cavity (21), and the sleeve spring (7) abuts between the first end (24) and the sleeve (23) in the axial direction, The sleeve (3) can slide axially under the combined action of the elastic force of the sleeve spring (7) and the liquid pressure from the oil hole (23), so that the second boss portion (31) ) Can close or open the oil hole (23).
The hydraulic lash adjuster according to claim 1, wherein the extension direction of the oil hole (23) is inclined from the outside to the inside toward the first end (24) with respect to the radial direction.
The hydraulic lash adjuster according to claim 1, wherein the axial end of the sleeve spring (7) abuts against the sleeve at the radial inner side of the second boss portion (31) On the tube (3).
The hydraulic lash adjuster according to claim 3, wherein the hydraulic lash adjuster further comprises an end cover ring (8), and the sleeve spring (7) passes through the end cover ring (8). Abut the sleeve (3).
The hydraulic lash adjuster according to claim 1, wherein the first boss portion (22) and the second boss portion (31) have corresponding shapes, so that they can be attached to each other .
The hydraulic lash adjuster according to claim 5, characterized in that, when viewed in a longitudinal section, the first boss portion (22) and the second boss portion (31) have an arc-shaped surface profile .
The hydraulic lash adjuster according to claim 1, wherein the sleeve (3) has a first portion adjacent to the second boss portion (31) and extending toward the first end (24) Section (32), the first section (32) is straight cylindrical and can slide along the inner surface of the inner cavity (21).
The hydraulic lash adjuster according to any one of claims 1 to 7, characterized in that the plunger (2) has a plurality of the oil holes (23) distributed at intervals in the circumferential direction.
The hydraulic lash adjuster according to claim 8, wherein a plurality of the oil holes (23) are evenly distributed along the circumferential direction.