阅读说明：本技术 用于气门机构的液压间隙调节器 (Hydraulic lash adjuster for a valve train ) 是由 朱峰 于 2020-03-25 设计创作，主要内容包括：本发明涉及一种用于气门机构的液压间隙调节器。该液压间隙调节器包括筒状的壳体、柱塞和套筒,壳体具有封闭的第一端部和开放的第二端部,柱塞具有第三端部和中空的内腔,第三端部从第二端部沿轴向插入壳体中,其中,该液压间隙调节器还包括独立于柱塞的底板,第三端部为开放端,套筒的至少一端从第三端部插入内腔中,底板在第三端部处安装到柱塞,从而限定内腔的一端。本发明的液压间隙调节器能够有效提高柱塞内的贮油量并且易于组装。(The present invention relates to a hydraulic lash adjuster for a valve train. The hydraulic lash adjuster includes a cylindrical housing having a closed first end and an open second end, a plunger having a third end and a hollow interior cavity, the third end being inserted axially into the housing from the second end, wherein the hydraulic lash adjuster further includes a bottom plate independent of the plunger, the third end being an open end, at least one end of the sleeve being inserted into the interior cavity from the third end, the bottom plate being mounted to the plunger at the third end thereby defining one end of the interior cavity. The hydraulic lash adjuster of the present invention can effectively increase the amount of oil stored in the plunger and is easy to assemble.)

1. A hydraulic lash adjuster for a valve train comprising a cylindrical housing (1), a plunger (2) and a sleeve (3), the housing (1) having a closed first end (11) and an open second end (12), the plunger (2) having a third end (21) and a hollow interior (23), the third end (21) being inserted axially into the housing (1) from the second end (12),

it is characterized in that the preparation method is characterized in that,

the hydraulic lash adjuster further comprises a base plate (4) independent of the plunger (2), the third end (21) being an open end, at least one end of the sleeve (3) being inserted into the internal cavity (23) from the third end (21), the base plate (4) being mounted to the plunger (2) at the third end (21) so as to define one end of the internal cavity (23).

2. A hydraulic lash adjuster according to claim 1 wherein the sleeve (3) has a fifth end (31) and a sixth end (32), the sixth end (32) being inserted into the internal cavity (23) from the third end (21), the fifth end (31) being an open end mounted radially inwardly of the third end (21), the base plate (4) being mounted radially inwardly of the fifth end (31).

3. A hydraulic lash adjuster according to claim 2, wherein the base plate (4) is fixed to the fifth end portion (31) by an interference fit, the fifth end portion (31) being fixed to the third end portion (21) by an interference fit.

4. A hydraulic lash adjuster according to claim 2, characterized in that the plunger (2) has a step (24) radially inside the third end (21), and the sleeve (3) has a radial section (33) at the fifth end (31), the radial section (33) abutting the step (24) axially inwards from the third end (21).

5. A hydraulic lash adjuster according to claim 4, characterized in that the portion of the sleeve (3) extending from the outer periphery of the radial section (33) towards outside the inner cavity (23) constitutes a first axial section (34) of the sleeve (3), the bottom plate (4) being mounted radially inside the first axial section (34) and abutting the radial section (33) axially inwards from the fifth end (31).

6. A hydraulic lash adjuster according to claim 5, characterized in that the part of the sleeve (3) extending from the inner periphery of the radial section (33) into the inner cavity (23) constitutes a second axial section (35) of the sleeve (3), the largest outer diameter of the second axial section (35) being smaller than the inner diameter of the step (24).

7. A hydraulic lash adjuster according to any of claims 2 to 6 further comprising a one-way valve (6) mounted to the third end portion (21), the base plate (4) having a through bore (41) running axially therethrough, the one-way valve (6) selectively closing the through bore (41) such that liquid can only flow out of the internal cavity (23) through the through bore (41) in one direction.

8. A hydraulic lash adjuster according to claim 7, characterized in that the one-way valve (6) is mounted on the side of the bottom plate (4) facing away from the inner cavity (23).

9. A hydraulic lash adjuster according to claim 8 wherein the check valve (6) comprises a valve seat (61), the valve seat (61) having a wing (64) extending radially outwardly at an end towards the base plate (4), the plunger (2) having a mounting slot (25) radially inwardly of the third end portion (21), an outer edge of the wing (64) being inserted into the mounting slot (25) to mount the valve seat (61) to the plunger (2).

10. A hydraulic lash adjuster according to claim 9 wherein the fifth end (31) has a notch (36) in the circumferential direction, the outer edge of the wing (64) being inserted through the notch (36) into the mounting slot (25).

Technical Field

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

Background

In an internal combustion engine of a motor vehicle, a rocker arm for pushing a valve stem to control opening and closing of a valve is generally provided. The rocker arm is typically driven by a cam to swing about a hydraulic lash adjuster, which automatically adjusts the lash between the cam and the rocker arm through telescopic movement of its plunger within the housing. A typical hydraulic lash adjuster configuration is found, for example, in CN 109386334 a. In such a typical configuration, a low pressure chamber for storing liquid is formed in the plunger inner cavity, a high pressure chamber for storing liquid is formed between the plunger bottom and the housing bottom, and the low pressure chamber and the high pressure chamber are communicated through a check valve, thereby allowing liquid to flow from the low pressure chamber into the high pressure chamber. An oil supply hole is formed in a side wall of the plunger, and oil can be supplied to the low pressure chamber in the plunger inner cavity through the oil supply hole. In the stage when the engine is just started, if the amount of oil in the low pressure chamber is insufficient and the low pressure chamber does not have enough liquid to be replenished into the high pressure chamber, noise may be caused. In some internal combustion engines, however, the hydraulic lash adjusters are often tilted, which causes the liquid in the low pressure chamber to flow out of the oil holes in the side wall of the plunger, thereby reducing the amount of liquid in the low pressure chamber.

There have been many prior arts which have been made to solve the above problems. For example, US 5979377a discloses a hydraulic lash adjuster whose plunger is composed of two parts, an upper plunger and a lower plunger. The hydraulic clearance adjuster is characterized in that an elongated sleeve is arranged in an inner cavity of an upper plunger, an oil hole leads to an annular space formed between the sleeve and the inner wall of the upper plunger, and liquid in the sleeve can only flow into the annular space communicated with the oil hole from the space at the top of the sleeve, so that the liquid in the sleeve is not easy to leak from the oil hole under the condition of inclination. In order to fit the sleeve into the interior cavity of the plunger, there must be a sufficiently large access opening in the plunger, and therefore such a sleeve is only suitable for use with a similar two-part plunger arrangement. With the one-piece plunger construction, however, such a sleeve cannot be used because there is no opening to insert the sleeve into the bore.

Disclosure of Invention

Accordingly, an object of the present invention is to provide a hydraulic lash adjuster that can increase the amount of oil stored in a plunger and that is easy to assemble.

The above-mentioned object is achieved by a hydraulic lash adjuster for a valve train according to the present invention. The hydraulic lash adjuster includes a cylindrical housing having a closed first end and an open second end, the first end being axially opposite the second end, a plunger having a hollow interior and axially opposite third and fourth ends, the third end of the plunger being axially inserted into the housing from the second end of the housing; wherein the hydraulic lash adjuster further comprises a base plate independent of the plunger, the third end of the plunger being an open end, at least one end of the sleeve being inserted into the internal cavity from the open third end, the base plate being mounted directly or indirectly to the plunger at the third end, thereby defining one end of the internal cavity. This means that the bottom plate defining the bottom end of the cavity in the plunger is a separate component that is assembled to the plunger, and the bottom end of the cavity can be formed by fitting the sleeve into the cavity through the open end of the plunger before assembling the bottom plate. The sleeve may be fully inserted into the internal cavity away from the base plate or may extend partially into the internal cavity and engage the assembly of the base plate or other components by a structure located outside the internal cavity.

According to a preferred embodiment of the present invention, the sleeve may have a fifth end and a sixth end which are opposite in the axial direction, the sixth end of the sleeve is inserted into the inner cavity from the third end of the plunger, the opposite fifth end is an open end installed radially inward of the third end of the plunger, and the bottom plate may be installed radially inward of the fifth end, such that the plunger, the sleeve and the bottom plate constitute a structure which is nested in sequence from the outside to the inside, thereby enabling the bottom plate to be more firmly installed on the plunger. Preferably, the bottom plate may be secured to the fifth end portion by an interference fit, and the fifth end portion may also be secured to the third end portion by an interference fit, thereby forming a reliable sealing interface that prevents liquid in the interior cavity from leaking through gaps between the mounting surfaces.

According to another preferred embodiment of the invention, the plunger may have a step radially inside of its third end, and correspondingly, the thin-walled sleeve may have a radial section at its fifth end, the radial section of the sleeve abutting the step axially inwardly from the third end, thereby defining the axial position of the sleeve relative to the plunger.

According to a further preferred embodiment of the invention, the portion of the sleeve extending from the outer periphery of the radial section towards the outside of the inner cavity may constitute a first axial section of the sleeve, the bottom plate being mounted radially inside the first axial section and abutting the radial section axially inwards from the fifth end, thereby defining an axial position of the bottom plate relative to the sleeve and the plunger.

According to a further preferred embodiment of the invention, the part of the sleeve extending from the inner periphery of the radial section into the inner cavity may constitute a second axial section of the sleeve, the maximum outer diameter of which is smaller than the inner diameter of the step of the plunger, so that the second axial section can be fully inserted into the inner cavity.

According to another preferred embodiment of the present invention, the hydraulic lash adjuster may further include a check valve mounted to the third end, the base plate having a through bore extending axially therethrough, the check valve selectively closing the through bore such that liquid can only flow out of the internal cavity through the through bore in a single direction, thereby preventing liquid from flowing into the internal cavity from the high pressure chamber between the housing and the plunger. Preferably, the one-way valve may be mounted on a side of the base plate facing away from the internal cavity.

According to another preferred embodiment of the present invention, the check valve may include a valve seat having a wing extending toward a radially outer side at one end toward the bottom plate, the plunger having a mounting groove at a radially inner side of a third end thereof, an outer edge of the wing of the valve seat being inserted into the mounting groove, thereby mounting the valve seat to the plunger. Preferably, the outer edge of the wing may have an interference fit with the mounting groove to fix the position of the valve seat relative to the plunger.

According to another preferred embodiment of the present invention, the fifth end of the sleeve may have a notch in a circumferential direction, and the outer edge of the wing of the valve seat is inserted into the mounting groove through the notch. In this case, the circumferential length of the notches is preferably equal to the circumferential length of the wings, so that the wings of the valve seat can cooperate with the notches of the sleeve to prevent rotation of the sleeve.

Drawings

The invention is further described below with reference to the accompanying drawings. Identical reference numbers in the figures denote functionally identical elements. Wherein:

FIG. 1 illustrates a cross-sectional view of a hydraulic lash adjuster according to an embodiment of the present disclosure;

FIGS. 2 a-2 c respectively show schematic views of various components of a hydraulic lash adjuster according to an embodiment of the present disclosure; and

fig. 3 shows a partially enlarged view of the hydraulic lash adjuster in fig. 1.

Detailed Description

A specific embodiment of a 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 included to illustrate the principles of the invention, which is not to be limited to the preferred embodiments described, but is to be defined by the appended claims.

According to an embodiment of the present invention, a hydraulic lash adjuster for a valve train of an internal combustion engine is provided. FIG. 1 shows a 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 and has a first end portion 11 and a second end portion 12 opposite to each other in the axial direction, wherein the first end portion 11 is a closed end and the second end portion 12 is an open end. The plunger 2 is also substantially cylindrical and has third and fourth end portions 21, 22 opposite to each other in the axial direction. The third end portion 21 of the plunger 2 is an open end that is inserted axially into the housing 1 from the second end portion 12 of the housing 1, while the fourth end portion 22 of the plunger 2 is located outside the housing 1 for supporting a valve rocker (not shown). The plunger 2 has a substantially cylindrical hollow interior 23.

The hydraulic lash adjuster also includes a sleeve 3 and a bottom plate 4. The sleeve 3 is a thin-walled cylindrical structure with both ends open, and has a fifth end 31 and a sixth end 32 opposite to each other in the axial direction. The sixth end portion 32 is inserted axially into the inner cavity 23 from the third end portion 21 of the plunger 2, and the fifth end portion 31 is fixedly mounted radially inside the third end portion 21, for example, by interference fit. A circular base plate 4 is also fixedly mounted, for example by interference fit, radially inside the fifth end 31, so as to define one axial end of the internal cavity 23, in other words, the surface of the base plate 4 facing the fourth end 22 defines an axial end face of the internal cavity 23. A high-pressure chamber 7 for storing liquid is formed between the base plate 4 and the first end 11 of the housing 1, while the inner cavity 23 of the plunger 2 constitutes a low-pressure chamber for storing liquid. The bottom plate 4 is centrally formed with a through hole 41, and the high pressure chamber 7 communicates with the inner chamber 23 through the through hole 41. On the side of the bottom plate 4 facing the first end 11 a one-way valve 6 is mounted, which one-way valve 6 only allows liquid to flow from the inner chamber 23 into the high-pressure chamber 7 and not the reverse flow. A return spring 5, for example in the form of a helical spring, is axially abutted between the bottom plate 4 and the first end 11 of the housing 1, so that the plunger 2, the sleeve 3 and the bottom plate 4 as a whole can slide axially in the housing 1 under the combined action of the elastic force of the return spring 5 and the liquid pressure. In this case, the plunger 2 and the bottom plate 4 together constitute a structure corresponding to the one-piece plunger in the related art.

Fig. 2a to 2c show specific configurations of the plunger 2, the sleeve 3, and the bottom plate 4 according to the present embodiment, respectively. As shown in fig. 2a, the plunger 2 has a second oil hole 26 penetrating in the radial direction at the axial middle portion, and the second oil hole 26 may communicate with the first oil hole 13 in the housing 1 so that the liquid flowing in from the first oil hole 13 can enter the inner chamber 23 through the second oil hole 26. The plunger 2 also has a step 24 and an annular mounting groove 25 radially inward of the third end portion 21. The substantially radially extending surface of the step 24 faces away from the fourth end 22, so that the inner diameter of the plunger 2 narrows on one side of the step 24 in the axial direction toward the fourth end 22 relative to the other side in the axial direction. The step 24 is axially closer to the fourth end 22 than the mounting groove 25.

As shown in fig. 2b, the sleeve 3 has a substantially radially extending radial section 33 at the fifth end 31, the sleeve 3 being divided in the axial direction by the radial section 33 into a first axial section 34 and a second axial section 35. The first axial section 34 extends from the outer periphery of the radial section 33 to one axial side, and the second axial section 35 extends from the inner periphery of the radial section 33 to the other axial side. The first axial section 34 may have a uniform diameter, while the second axial section 35 does not necessarily extend completely axially, but may extend in sections with different diameters and be connected between sections of different diameters by transition sections to accommodate the space in the inner cavity 23. The outer diameter of the first axial section 34 is larger than the largest outer diameter of the second axial section 35. The first axial section 34 has a plurality of circumferentially spaced notches 36 at the end, each notch 36 extending axially from an end face of the first axial section 34.

Fig. 3 shows a partial detail of the section of fig. 1 at the base plate 4. As shown in fig. 3, when the respective components of the hydraulic lash adjuster according to the present embodiment are assembled together, the sixth end 32 of the sleeve 3 is inserted into the internal cavity 23 from the third end 21 of the plunger 2, so that the second axial section 35 of the sleeve 3 is located entirely within the internal cavity 23, thereby forming an annular space between the second axial section 35 and the inner wall of the plunger 2. The maximum outer diameter of the second axial section 35 is smaller than the inner diameter of the step 24, i.e. smaller than the mouth inner diameter of the inner cavity 23, so that the second axial section 35 can be inserted into the inner cavity 23. On the side of the step 24 facing away from the fourth end 22, a first axial section 34 of the sleeve 3 is fixed, for example by interference fit, to the radially inner side of the third end 21 of the plunger 2, and a radial section 33 of the sleeve 3 abuts axially towards the fourth end 22 onto a substantially radially extending surface of the step 24. The base plate 4 is fixed, for example by interference fit, radially on the inside of the first axial section 34, and an axial end face of the base plate 4 facing the fourth end 22 abuts axially on the side of the radial section 33 facing away from the fourth end 22. The outer side of the first axial section 34 is in sealing engagement with the plunger 2 and the inner side of the first axial section 34 is in sealing engagement with the base plate 4 to prevent leakage of liquid from the interior chamber 23.

The check valve 6 has a valve seat 61, a steel ball 62, and a valve spring 63. The valve seat 61 is substantially cylindrical, and has one end closed and the other end opened in the axial direction. The valve seat 61 has a plurality of wings 64 extending radially outward at the open end, the wings 64 being circumferentially spaced apart and corresponding to the notches 36 of the sleeve 3, respectively. The circumferential length of each notch 36 is equal to the circumferential length of the corresponding wing 64. The open end of the valve seat 61 abuts on the bottom plate 4 in the axial direction, and the outer edge of each wing 64 is inserted into the mounting groove 25 on the plunger 2 through the corresponding notch 36, respectively, thereby assembling the check valve 6 with the plunger 2. The outer edges of the wings 64 preferably have an interference fit with the mounting slots 25 to prevent rotation of the valve seat 61 and sleeve 3 relative to the plunger 2. The end of the return spring 5 abuts on the wing portion 64, and further indirectly abuts on the bottom plate 4 through the wing portion 64. A steel ball 62 and a valve spring 63 are mounted inside the valve seat 61. The steel ball 62 may be spherical and the valve spring 63 may be, for example, a coil spring. One side of the steel ball 62 abuts the valve seat 61 via the valve spring 63, while the other side directly abuts the base plate 4 and is aligned with the through hole 41. In order to position the spherical steel ball 62, the side of the through hole 41 facing the non-return valve 6 may have a spherical profile, as shown in fig. 2 c. The steel ball 62 can open or close the through hole 41 by the combined action of the liquid pressure and the elastic force of the valve spring 63.

In the hydraulic lash adjuster according to the embodiment of the invention, the end of the plunger 2 facing the inside of the housing 1 is an open end, and the end of the inner cavity 23 of the plunger 2 is defined by the assembled bottom plate 4, so that the sleeve 3 can be mounted from the open end before the bottom plate 4 is assembled. An annular space formed between the outside of the sleeve 3 and the inner wall of the inner cavity 23 directly communicates with the second oil hole 26, while the annular space communicates with the inside space of the sleeve 3 only near the top of the plunger 2. Therefore, when no liquid flows in from the second oil hole 26 and the hydraulic lash adjuster is placed obliquely, more liquid can be stored inside the sleeve 3 without flowing out directly from the second oil hole 26. The hydraulic lash adjuster is simple in construction and easy to machine and assemble, and is particularly suited for use with a one-piece plunger arrangement.

It should be noted that the present invention aims to simplify the mounting of the sleeve 3 by means of the assembled bottom plate 4, wherein the mutual connection of the plunger 2, the sleeve 3, the bottom plate 4 and the non-return valve 6 is possible in many possible ways and is not limited to the specific way shown in the above described embodiments and the attached drawings. For example, the bottom plate 4 may be mounted directly on the radially inner side of the plunger 2, and correspondingly, the sleeve 3 may be mounted completely in the inner cavity 23. Therefore, various technical solutions for simplifying the installation of the sleeve by the assembled bottom plate belong to the scope of the present invention.

Although possible embodiments have been described by way of example in the above description, it should be understood that numerous embodiment variations exist, still by way of combination of all technical features and embodiments that are known and that are obvious to a person skilled in the art. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. From the foregoing description, one of ordinary skill in the art will more particularly provide a technical guide to convert at least one exemplary embodiment, wherein various changes may be made, particularly in matters of function and structure of the components described, without departing from the scope of the following claims.

List of reference numerals

1 casing

11 first end portion

12 second end portion

13 first oil hole

2 plunger piston

21 a third end part

22 fourth end portion

23 inner cavity

24 step part

25 mounting groove

26 second oil hole

3 sleeve

31 fifth end part

32 sixth end portion

33 radial segment

34 first axial section

35 second axial section

36 gap

4 bottom plate

41 through hole

5 Return spring

6 one-way valve

61 valve seat

62 steel ball

63 valve spring

64 wing part

7 high pressure chamber