CN113970003A

CN113970003A - Check valve and hydraulic lash adjuster

Info

Publication number: CN113970003A
Application number: CN202010710974.4A
Authority: CN
Inventors: 朱峰
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Holding China Co Ltd
Priority date: 2020-07-22
Filing date: 2020-07-22
Publication date: 2022-01-25

Abstract

The invention relates to a check valve and a hydraulic lash adjuster. The one-way valve comprises a cylindrical valve cover, a valve core and an elastic reset piece, wherein the valve core is installed in the valve cover, the valve cover is provided with a bottom plate at one axial end, the valve core is provided with a bottom end part facing the bottom plate, the bottom end part is cylindrical, and the elastic reset piece is abutted between the bottom end part and the bottom plate in the axial direction. The check valve and the hydraulic lash adjuster of the present invention can ensure more reliable operation of the check valve.

Description

Check valve and hydraulic lash adjuster

Technical Field

The invention relates to the technical field of vehicles. In particular, the present invention relates to a check valve and a hydraulic lash adjuster including such a check valve.

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 typical constructions, 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 one-way valve which only allows liquid to flow from the low pressure chamber into the high pressure chamber.

Existing hydraulic lash adjusters typically use a ball check valve that includes a cylindrical bonnet, a spherical check ball, and a spring as a return member. One end of the valve cover is closed, the other end of the valve cover is opened, and the spring is abutted between the closed end of the valve cover and the check ball along the axial direction. When the check ball is used, the check ball pushes the spring to reciprocate along the axial direction under the action of the liquid pressure. When the relative positions of the various components of the check valve are incorrect, the spring may tip over, thereby causing the check valve to fail.

Disclosure of Invention

Therefore, the technical problem to be solved by the present invention is to provide a more reliable check valve and a hydraulic lash adjuster.

The above technical problem is solved by a non-return valve according to the present invention. The one-way valve comprises a cylindrical valve cover, a valve core and an elastic reset piece, wherein the valve core is installed in the valve cover, and one end of the valve cover in the axial direction is provided with a bottom plate. Wherein, the case has the bottom part towards the bottom plate, and the bottom part is cylindrical, and elasticity reset piece along axial butt between bottom part and bottom plate. Compared with a spherical valve core, the valve core reduces the gap between the bottom end part and the side wall of the valve cover through the cylindrical bottom end part, so that the position relation of the valve core relative to the valve cover is restrained through the matching between the cylindrical bottom end part and the side wall of the valve cover, and the valve core is prevented from being deviated or falling off from the elastic reset piece and falling over of the spring in the axial movement process. In this case, the elastic return member may be a coil spring in general, but may be another form of elastic return member.

According to a preferred embodiment of the invention, the bottom end portion may have a recess axially recessed from the end face, the resilient return member extending into the recess. In this case, the recess receives the end portion of the elastic restoring member, and restrains the positional relationship of the elastic restoring member with respect to the valve element, thereby further preventing the valve element from being disengaged from the elastic restoring member. Preferably, the recess may have a flat bottom surface extending perpendicular to the axial direction, and thus the end of the elastic restoring member may stably abut on the flat bottom surface. In order to better limit the positional relationship of the elastic return element with respect to the valve core by means of the recess, the recess and the elastic return element may preferably have corresponding cross-sectional shapes, for example both have a circular cross-section, so that a form-fitting relationship is formed.

According to another preferred embodiment of the invention, the cartridge may also have a top portion facing away from the base plate, the top portion being axially opposite the bottom portion, the top portion having a circular cross-section and having an outer side surface with a decreasing radius in an axial direction away from the base plate for insertion into the orifice to be closed into a close fitting relationship therewith. For example, the tip portion may be formed in a partial sphere shape.

According to another preferred embodiment of the present invention, the bottom plate may have a communication hole therethrough so that the hydraulic fluid enters and exits the valve cover through the communication hole.

The above technical problem is also solved by a hydraulic lash adjuster according to the present invention. The hydraulic lash adjuster comprises a housing and a plunger having a first end inserted axially into the housing, wherein the hydraulic lash adjuster further comprises a one-way valve having the above-mentioned features, the one-way valve being mounted externally of the first end.

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 shows a schematic view of a check valve according to an embodiment of the invention when installed in a hydraulic lash adjuster;

FIG. 2 shows a cross-sectional view of a one-way valve according to an embodiment of the invention;

FIG. 3 illustrates a perspective view of a valve cover of a one-way valve according to an embodiment of the present invention; and

FIG. 4 illustrates a perspective view of a valve cartridge of a check valve according to an embodiment of the present invention.

Detailed Description

Embodiments of a check valve and 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 check valve is provided, preferably for use in a hydraulic lash adjuster in an engine valve train. Fig. 1 shows a schematic cross-sectional view of a check valve 30 according to this embodiment when installed in a hydraulic lash adjuster. As shown in fig. 1, the hydraulic lash adjuster includes a housing 10, a plunger 20, and a check valve 30 according to the present embodiment. The housing 10 and the plunger 20 are each a hollow cylindrical member. The housing 10 has an open end at one axial end and a closed end at the other axial end, and the plunger 20 has a first end inserted into the housing 10 from the open end in the axial direction. A first hydraulic chamber 11 is formed between the first end of the plunger 20 and the closed end of the housing 10, and a second hydraulic chamber 21 is formed inside the plunger 20. The first hydraulic pressure chamber 11 and the second hydraulic pressure chamber 21 may communicate through a through hole 22 on the first end of the plunger 20. The check valve 30 is installed outside the first end of the plunger 20 and is integrally located in the first hydraulic chamber 11 to selectively close the through hole 22.

As shown in fig. 2, the check valve 30 includes a bonnet 31, a spool 32, and an elastic restoring member 33. As shown in fig. 3, the valve cover 31 has a bottom plate 311 and a side wall 312. The side wall 312 is substantially cylindrical, and a substantially circular bottom plate 311 defines one axial end of the valve cover 31 facing away from the plunger 20, while the other axial end of the valve cover 31 is open toward the plunger 20. Preferably, a communication hole 313 may be further formed at the center of the bottom plate 311 to penetrate therethrough

As shown in fig. 4, the spool 32 has a bottom end portion 321 for abutting the elastic restoring member 33 and a top end portion 322 for abutting the to-be-plunger 20. The bottom end portion 321 is formed in a cylindrical shape. The central area of the end face of the base end portion 321 is recessed in the axial direction, thereby forming a recess 323. Preferably, the recess 323 may have a flat bottom surface extending perpendicular to the axial direction.

The tip portion 322 has a circular cross-section. The tip portion 322 has an outer side surface 324 and a top surface 325. The outboard surface 324 tapers in radius in an axial direction away from the base plate 311. Preferably, the outer side surface 324 may have a curved profile, as viewed in cross-section through the central axis of the valve spool 32. The top surface 325 may be a flat surface extending perpendicular to the axial direction or a surface having a central recess. As shown in FIG. 2, when the check valve 30 is installed in a hydraulic lash adjuster, the outer side surface 324 abuts the edge of the through bore 22, while the top surface 325 is entirely radially inward of the through bore 22. The shape of the outer side surface 324 helps to closely fit the edges of the through-hole 22, thereby sealing the through-hole 22. The central recess in the top surface 325 facilitates increasing the volume of the second hydraulic chamber 21. It should be noted that the shape of the top surface 325 is not required. The shape of the top surface 325 is not particularly required, as only the outer side surface 324 has a mating relationship with the through-hole 22. Thus, the entire tip portion 322 may be formed in a partial sphere shape, where the entire tip portion 322 only has a partial spherical outer side surface 324 and no longer has a top surface 325.

The elastic return element 33 is formed, for example, as a conventional helical spring. The elastic restoring member 33 abuts between the base end portion 321 of the spool 32 and the bottom plate 311 of the cap 31 in the axial direction. The end of the elastic return member 33 facing the plunger 20 extends into the recess 323 and abuts on the flat bottom surface of the recess 323. In order to accommodate the ends of the elastic return element 33 in a form-fitting manner, the recess 323 can have a cross-sectional shape corresponding to the elastic return element 33. For the elastic return member 33 in the form of a helical spring, which is circular in cross-section, the recess 323 correspondingly has a circular cross-section.

When the liquid pressure in the second hydraulic pressure chamber 21 is small, the valve element 32 abuts against the bottom of the plunger 20 by the elastic force of the coil spring 33, thereby closing the through hole 22; when the hydraulic pressure in the second hydraulic pressure chamber 21 is higher than the first hydraulic pressure chamber 11 and the pressure difference is sufficiently large, this pressure difference will push the spool 32 toward the bottom plate 311 against the elastic force of the coil spring 33. During the axial movement of the spool 32, since the base end portion 321 is formed in a cylindrical shape, the clearance between the base end portion 321 and the side wall 312 of the bonnet 31 is small, and by the form fit between the base end portion 321 and the bonnet 31, the radial displacement of the spool 32 can be restrained, thereby ensuring that the spool 32 and the bonnet 31 maintain the correct positional relationship. At the same time, the concave portion 323 of the valve core 32 cooperates with the elastic restoring member 33 to define the positional relationship of the valve core 32 with respect to the elastic restoring member 33 during movement, and thus the positional relationship of the elastic restoring member 33 with respect to the bonnet 31. Therefore, during the operation of the check valve 30, the valve core 32 and the elastic restoring member 33 can always maintain the correct positioning, and are not easy to deflect or dislocate, thereby improving the reliability of the check valve 30. In addition, due to the communication hole 313 on the bottom plate 311, the hydraulic fluid in the bonnet 31 can enter and exit the bonnet 31 through the communication hole 313, thereby avoiding the influence of the cylindrical bottom end part 321 on the fluid flow.

According to another embodiment of the present invention, a hydraulic lash adjuster is also provided. The hydraulic lash adjuster includes the housing 10, the plunger 20, and the check valve 30 in the foregoing embodiment. Such a hydraulic lash adjuster thus has all the features and advantages of the check valve 30 according to the above-described embodiment.

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

10 casing

11 first hydraulic chamber

20 plunger

21 second hydraulic chamber

22 through hole

30 one-way valve

31 valve cover

311 bottom plate

312 side wall

313 communication hole

32 valve core

321 bottom end part

322 tip portion

323 recess

324 outer side surface

325 top surface

33 elastic restoring member

Claims

1. A check valve (30) comprises a cylindrical valve cover (31), a valve core (32) and an elastic reset piece (33), wherein the valve core (32) is installed in the valve cover (31), the valve cover (31) is provided with a bottom plate (311) at one axial end,

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

the valve core (32) is provided with a bottom end part (321) facing the bottom plate (311), the bottom end part (321) is cylindrical, and the elastic resetting piece (33) is abutted between the bottom end part (321) and the bottom plate (311) along the axial direction.

2. A one-way valve (30) according to claim 1, wherein said bottom end portion (321) has a recess (323) axially recessed from the end face, said elastic return member (33) extending into said recess (323).

3. The check valve (30) of claim 2, wherein the recess (323) has a flat bottom surface extending perpendicular to the axial direction.

4. The non-return valve (30) according to claim 2, characterised in that the recess (323) and the elastic return member (33) have a corresponding cross-sectional shape.

5. The non-return valve (30) according to claim 1, characterized in that the spool (32) also has a top portion (322) facing away from the bottom plate (311), the top portion (322) being axially opposite the bottom portion (321), the top portion (322) having an outer side surface (324) with a decreasing radius in an axial direction away from the bottom plate (311).

6. The one-way valve (30) of claim 5, wherein the tip portion (322) is formed in a partial spherical shape.

7. Non-return valve (30) according to claim 1, characterized in that the bottom plate (311) has a communication hole (313) therethrough.

8. The non-return valve (30) according to any one of claims 1 to 7, characterised in that the elastic return member (33) is a helical spring.

9. A hydraulic lash adjuster comprising a housing (10) and a plunger (20), a first end of the plunger (20) being axially inserted into the housing (10), characterized in that the hydraulic lash adjuster further comprises a one-way valve (30) according to any one of claims 1 to 8, the one-way valve (30) being mounted externally of the first end.