Hydraulic lash adjuster

Abstract

The invention relates to a hydraulic lash adjuster. The hydraulic lash adjuster includes: a housing including an upper port and a lower port in an axial direction; the plunger is axially and movably located in the shell, a low-pressure chamber is formed in an inner cavity of the plunger, a high-pressure chamber is formed by the lower end of the plunger and the lower port of the shell, and a first through hole is further formed in the lower end of the plunger; the first valve assembly is located at the lower end of the high-pressure chamber and abuts against the lower port of the shell, and oil outside the shell is allowed to enter the high-pressure chamber from the lower port; the second valve assembly is located at the upper end of the high-pressure chamber and comprises a sealing ball and a supporting plate, and the supporting plate is located at the lower end of the sealing ball, supports the sealing ball to abut against the first through hole of the plunger and allows oil liquid and bubbles in the high-pressure chamber to enter the low-pressure chamber from the first through hole; and the reset spring is supported between the first valve assembly and the supporting plate in the axial direction.

Description

Technical Field

[0001] The present invention relates to the technical field of engine accessories, and in particular to a hydraulic lash adjuster. Background Art

[0002] Internal combustion engines in motor vehicles typically feature rocker arms that control the opening and closing of valves by pushing valve stems. Driven by a cam, the rocker arm's roller reciprocates, supported by a hydraulic lash adjuster. The hydraulic lash adjuster automatically adjusts the clearances between the cam and rocker arm, and between the rocker arm and valve, by retracting and extending its plunger within a housing (10).

[0003] Typical hydraulic lash adjuster 100 configuration (eg Figure 1 ), includes a housing 10, a plunger 20, a check valve 30, and a return spring 40. In such a typical structure, a low-pressure chamber L for storing oil is formed in the inner cavity of the plunger 20, and a high-pressure chamber H for storing oil is formed between the bottom of the plunger 20 and the bottom of the housing 10. The low-pressure chamber L and the high-pressure chamber H are connected through the check valve 30, which allows oil to flow from the low-pressure chamber L into the high-pressure chamber H.

[0004] Oil supply holes 11 are formed on the sidewalls of both the housing 10 and the plunger 20. Hydraulic oil in the engine cylinder head environment can be supplied to the low-pressure chamber of the plunger 20 through the oil supply holes 11. When the valve train is operating, the cam has a base circle and a cam (i.e., the cam's lifting profile). The rocker arm squeezes the plunger 20 under the action of the cam's extrusion roller. Due to the pressure difference between the high-pressure chamber H and the oil supply hole 11, some of the oil in the high-pressure chamber H leaks through the gap between the housing 10 and the plunger 20. While the cam is in its base circle, the pressure on the top of the plunger 20 is less than the hydraulic pressure in the high-pressure chamber H and the upward restoring force of the return spring. Therefore, the high-pressure chamber H begins to expand, temporarily creating a vacuum-like effect, causing the check valve 30 to open and the leaked oil to be replenished from the low-pressure chamber L to the high-pressure chamber H.

[0005] However, this structure has the problem of frequent oil leakage in the high-pressure chamber H, which requires continuous replenishment of oil from the low-pressure chamber L. Therefore, the low-pressure chamber L needs to be continuously replenished with oil from the cylinder head environment and maintain sufficient oil storage space. To this end, a separate oil pump and an additional oil supply channel need to be provided in the cylinder head, which results in high costs and complex structure.

[0006] In order to avoid oil leakage and avoid the high cost and complex structure caused by the need for continuous oil supply, in another related technology, such as Figure 2 As shown, the oil supply hole 11 of the housing 10 and the plunger 20 is cancelled, the low-pressure chamber L and the high-pressure chamber H are filled with oil when leaving the factory, and a sealing ring 50 is set in the gap between the housing 10 and the upper end of the plunger 20 to prevent oil leakage.

[0007] However, since the plunger 20 needs to reciprocate in the housing 10, the sealing ring 50 often produces a large resistance to the movement of the plunger 20. Therefore, when the engine speed is too fast and the resistance of the sealing ring 50 is too large, the liquid pressure in the high-pressure chamber H and the restoring force of the return spring cannot support the plunger 20 to reset in time. Not only can the gap between the structures of the valve mechanism not be compensated in time, resulting in failure of the hydraulic lash adjuster 100, but the oil in the low-pressure chamber L cannot be replenished to the high-pressure chamber H in time, which may cause the oil in the high-pressure chamber H to easily absorb air from the surrounding environment. After working for a long time, the oil that absorbs air tends to become spongy, easily compressed and reduced in rigidity, which is not conducive to the operation of the hydraulic lash adjuster 100.

[0008] In addition, if Figure 1 As shown, due to the existence of the oil supply hole 11 of the housing 10, the oil storage space of the hydraulic lash adjuster 100 in the related art cannot fill the entire inner cavity of the plunger 20, resulting in a waste of oil storage space and insufficient oil storage.

[0009] In another related technology, in order to increase the volume of the oil storage space, an oil collection shell can be further installed on the outside of the shell 10. However, after the oil collection shell is installed, the radial dimension of the entire hydraulic clearance adjuster 100 becomes larger than the existing radial dimension, which is not conducive to the current hybrid engine's pursuit of a compact structure. Summary of the Invention

[0010] In order to overcome the problems existing in the related art, the present disclosure provides a hydraulic lash adjuster.

[0011] According to a first aspect of an embodiment of the present disclosure, the present disclosure provides a hydraulic clearance adjuster, comprising: a housing, axially including an upper port and a lower port; a plunger, axially movably located in the housing, the inner cavity of the plunger forming a low-pressure chamber, the lower end of the plunger and the lower port of the housing forming a high-pressure chamber, the lower end of the plunger is also provided with a first through hole; a first valve assembly, located at the lower end of the high-pressure chamber, and abutting the lower port of the housing, allowing oil outside the housing to enter the high-pressure chamber from the lower port; a second valve assembly, located at the upper end of the high-pressure chamber, comprising a sealing ball and a support plate, the support plate being located at the lower end of the sealing ball, supporting the sealing ball to abut against the first through hole of the plunger, allowing oil and bubbles in the high-pressure chamber to enter the low-pressure chamber from the first through hole; and a return spring, the return spring being axially supported between the first valve assembly and the support plate.

[0012] In some embodiments, the support plate includes: a limiting hole, which is arranged in the middle of the support plate, and the limiting hole and the first through hole jointly define the position of the sealing ball; and an exhaust hole, which is axially arranged at the edge of the support plate to allow bubbles in the high-pressure chamber to pass through.

[0013] In some embodiments, a spiral groove is provided on the outer wall of the shell, the upper end of the spiral groove is connected to the outside of the shell, and the lower end of the spiral groove is connected to the lower port of the shell. The spiral groove is used to replenish the oil outside the shell into the high-pressure chamber.

[0014] In some embodiments, an outer wall of the shell is provided with an annular first liquid storage cavity, and the first liquid storage cavity divides the spiral groove into an upper spiral groove and a lower spiral groove along the axial direction.

[0015] In some embodiments, the side outer wall of the shell is provided with a radially penetrating second through hole, and the side outer wall of the plunger is provided with a radially penetrating third through hole, and the third through hole forms a second liquid storage chamber in the low-pressure chamber that extends upward from the third through hole to the cylinder head, wherein the third through hole is connected with the second through hole to connect the second liquid storage chamber with the first liquid storage chamber.

[0016] In some embodiments, a third annular groove is provided on the side outer wall of the shell, and the third annular groove is located below the second through hole, so that the first liquid storage cavity is stepped.

[0017] In some embodiments, a first annular groove is provided on the inner side wall of the shell, and a second annular groove is provided on the outer side wall of the plunger, wherein the second annular groove partially overlaps with the first annular groove in the axial direction and encloses a third liquid storage cavity, wherein the second through hole is provided at the first annular groove, and the third through hole is provided at the second annular groove.

[0018] In some embodiments, the hydraulic lash adjuster includes a collar, which is sleeved on the outside of the plunger and located in the third liquid storage chamber to limit the plunger from axially separating from the housing.

[0019] In some embodiments, the first valve assembly includes: a first check ball, the first check ball abutting the lower port; a valve seat, the valve seat covering the first check ball, the lower end of the valve seat is provided with a valve wing, the lower end of the return spring abuts the upper end surface of the valve wing, so that the valve wing remains abutted against the shell, and the valve seat is provided with a connecting hole connected to the high-pressure chamber; and a first spring, located in the valve seat, abutting between the upper end of the first check ball and the inner wall of the valve seat, for supporting the first check ball to open or close the lower port.

[0020] In some embodiments, the plunger includes: an upper plunger; and a lower plunger, which are separately arranged. The lower plunger includes an upper end plate, and the upper end plate abuts against the lower end of the upper plunger to form the bottom wall of the low-pressure chamber. The upper end plate of the lower plunger is provided with the first through hole, and the second valve assembly is located in the lower plunger.

[0021] The technical solutions provided by the embodiments of the present disclosure can provide the following beneficial effects: the lower port of the housing and the first valve assembly allow the high-pressure chamber to absorb oil from outside the housing through the lower port, thereby increasing the volume of the oil reservoir used to replenish the high-pressure chamber. The first through-hole and the second valve assembly at the lower end of the plunger allow the high-pressure chamber to be vented and drained from the upper end, discharging air bubbles within the high-pressure chamber, preventing the oil from becoming cotton-like and reducing its rigidity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0023] Figure 1 is a cross-sectional view of a hydraulic lash adjuster in the related art;

[0024] Figure 2 is a cross-sectional view of a hydraulic lash adjuster in another related art;

[0025] Figure 3 is a cross-sectional view of a hydraulic lash adjuster according to an exemplary embodiment;

[0026] Figure 4 yes Figure 3 A schematic diagram of the three-dimensional structure of the support plate of the hydraulic lash adjuster;

[0027] Figure 5 yes Figure 3 A schematic diagram of the structure of the housing of the hydraulic lash adjuster;

[0028] Figure 6 yes Figure 5 Schematic diagram of the machining process of the spiral groove on the outer wall of the middle shell;

[0029] Figure 7 yes Figure 3 A schematic diagram of the three-dimensional structure of all oil storage spaces of the hydraulic lash adjuster;

[0030] Figure 8 yes Figure 3 A schematic diagram of the three-dimensional structure of the valve cover of the first valve assembly;

[0031] Figure 9 The figure is a schematic diagram showing a combination of a rocker arm with a valve mechanism and a hydraulic lash adjuster according to an exemplary embodiment. DETAILED DESCRIPTION

[0032] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0033] In this disclosure, unless otherwise specified, the axial direction A, radial direction R, and circumferential direction W refer to the axial direction A, radial direction R, and circumferential direction W of the hydraulic lash adjuster 100, respectively; the axial direction A refers to Figure 3 and Figure 9 The vertical direction is represented by , and the radial direction R refers to Figure 3 and Figure 9 The horizontal direction is represented by ; the circumferential direction W refers to Figure 4 Circumferential direction in .

[0034] In order to solve the above-mentioned technical problems, the present disclosure provides a hydraulic lash adjuster 100, such as Figure 3 As shown, the hydraulic lash adjuster 100 includes a housing 10 , a plunger 20 , a first valve assembly 30 , a second valve assembly 40 and a return spring 50 .

[0035] Specifically, the shell 10 is in the shape of a circular sleeve and includes an upper port 11 and a lower port 12 along the axial direction A, that is, both axial ends of the shell 10 have openings that pass through the axial direction A, and the upper port 11 and the lower port 12 allow the entire shell 10 to pass through the axial direction A.

[0036] The lower end of the plunger 20 is inserted into the inner cavity of the housing 10 from the open end of the housing 10 , and the upper end of the plunger 20 protrudes from the upper port 11 of the housing 10 . The upper end of the plunger 20 is used to abut against the supporting end of the rocker arm described below.

[0037] The plunger 20 is a hollow cylindrical structure. The outer wall of the plunger 20 is loosely fitted with the inner wall of the housing 10 to allow the plunger 20 to move axially A relative to the housing 10. The inner cavity of the plunger 20 forms a low-pressure chamber L, which can store oil and is used to supply oil to the high-pressure chamber H during the return stroke of the plunger 20.

[0038] The return spring 50 is supported along the axial direction A between the lower end of the plunger 20 and the lower port 12 of the housing 10, thereby forming a high-pressure chamber H therebetween. The return spring 50 is compressed when the cam is in the convex angle. When the cam is in the base circle, the return spring 50 returns to its original position and pushes the plunger 20 upward, achieving a lift of the plunger 20, thereby compensating for the tolerance clearance of the entire valve train. The operating principle of the return spring 50 will be described in detail in the valve train section below.

[0039] The first valve assembly 30 is located in the high-pressure chamber H, and the lower end of the high-pressure chamber H abuts against the lower port 12 of the housing 10. The first valve assembly 30 is a one-way valve, allowing oil outside the housing 10 to enter the high-pressure chamber H from the lower port 12 of the housing 10.

[0040] The lower end of the plunger 20 is further provided with a first through-hole 21, which extends through the lower end of the plunger 20, allowing the high-pressure chamber H to communicate with the low-pressure chamber L. A second valve assembly 40 is located within the high-pressure chamber H, at its upper end. The second valve assembly 40 is disposed at the first through-hole 21. The first valve assembly 30 is a one-way valve that allows oil or bubbles in the high-pressure chamber H to enter the low-pressure chamber L through the first through-hole 21, while preventing oil in the low-pressure chamber L from entering the high-pressure chamber H. Therefore, the first valve assembly 30 functions as a one-way flow restrictor.

[0041] When the cam is on the base circle and the plunger 20 rises under the action of the return spring 50, the high-pressure chamber H absorbs oil, and the oil in the low-pressure chamber L of the plunger 20 cannot directly enter the high-pressure chamber H from the first through hole 21 at the lower end of the plunger 20. The oil in the low-pressure chamber L of the plunger 20 needs to overflow to the outside of the housing 10 and then enter the high-pressure chamber H from the lower port 12 of the housing 10.

[0042] It can be seen from this that the path for replenishing oil to the high-pressure chamber H is placed at the lower end of the high-pressure chamber H through the lower port 12 of the housing 10 and the first valve assembly 30, so that the high-pressure chamber H can only absorb oil from the outside of the housing 10 through the lower port 12, thereby increasing the volume of the oil storage chamber for replenishing oil to the high-pressure chamber H. When the high-pressure chamber H needs to be replenished with oil, there is no need to provide a separate oil pump and an additional oil supply channel in the cylinder head, thereby reducing costs and simplifying the structure.

[0043] In addition, since the oil storage space is increased, the high-pressure chamber H can be replenished with oil in a timely manner, thereby avoiding unnecessary air being sucked into the high-pressure chamber H, which would cause the oil in the high-pressure chamber H to become spongy, easily compressed, and have reduced rigidity.

[0044] Furthermore, in this embodiment, Figure 3As shown, the second valve assembly 40 includes a sealing ball 41 and a support plate 42. The support plate 42 is located at the lower end of the sealing ball 41. A return spring 50 is supported between the first valve assembly 30 and the support plate 42 along the axial direction A. The return spring 50 supports the sealing ball 41 by supporting the support plate 42, ensuring that the sealing ball 41 always maintains contact with the first through-hole 21. The support force of the return spring 50 is greater than the oil pressure within the low-pressure chamber L of the plunger 20, thereby preventing downward squeezing of the sealing ball 41 and preventing oil from entering the high-pressure chamber H through the first through-hole 21. When bubbles form within the high-pressure chamber H, they migrate along the axial direction A toward the upper end of the high-pressure chamber H. Due to the spherical shape of the sealing ball 41, when the sealing ball 41 abuts the first through-hole 21, there is a linear contact between the two, resulting in a relatively small contact area and range. Therefore, bubbles at the upper end of the high-pressure chamber H are more likely to escape from the linear contact between the sealing ball 41 and the first through-hole 21 and enter the low-pressure chamber L of the plunger 20. It can be seen that the second valve assembly 40 allows the oil or bubbles in the high-pressure chamber H to flow to the low-pressure chamber L from the abutment between the sealing ball 41 and the first through hole 21, but can prevent the oil in the low-pressure chamber L from entering the high-pressure chamber H through the first through hole 21.

[0045] The first through hole 21 and the second valve assembly 40 at the lower end of the plunger 20 allow the high-pressure chamber H to be vented and drained from the upper end, thereby promptly discharging the bubbles in the high-pressure chamber H, thereby preventing the bubbles from causing the oil in the high-pressure chamber H to become cotton-like and preventing the rigidity of the oil in the high-pressure chamber H from being reduced.

[0046] In the related art, a baffle can be used at the first through hole 21 to control the one-way flow of oil at the first through hole 21, that is, the baffle is abutted against the plunger 20 to achieve the sealing of the first through hole 21. The sealing performance of the baffle on the first through hole 21 is related to the flatness and roughness of the contact surface between the baffle and the plunger 20. Since the contact area between the baffle and the plunger 20 is large, the difficulty and cost of the polishing process of the contact surface between the baffle and the plunger 20 will inevitably increase.

[0047] The support plate 42 of the second valve assembly 40 in the present disclosure is spaced apart from the lower end of the plunger 20 axially A and does not contact, so no surface contact is required. The second valve assembly 40 blocks the first through hole 21 through the sealing ball 41. There is line contact between the sealing ball 41 and the first through hole 21, and the contact area and range are small. The processing accuracy requirements for the sealing ball 41 and the first through hole 21 at the lower end of the plunger 20 are also low, thereby reducing the processing difficulty and process cost of the sealing ball 41 and the lower end of the plunger 20.

[0048] Furthermore, the support plate 42 includes a limiting hole 421 and an exhaust hole 422. Figure 4As shown, the support plate 42 has a circular plate-like structure, and the limiting hole 421 is arranged in the middle of the center of the support plate 42. When the support plate 42 supports the sealing ball 41, the lower end of the sealing ball 41 is stuck in the limiting hole 421 of the support plate 42, and the upper end of the sealing ball 41 is stuck in the first through hole 21. It can be seen that the limiting hole 421 and the first through hole 21 jointly limit the position of the sealing ball 41 to avoid displacement of the sealing ball 41 in the radial or axial direction A. At the same time, the limiting hole 421 and the first through hole 21 allow the sealing ball 41 to produce appropriate rolling to discharge bubbles in the high-pressure chamber H.

[0049] Since the limiting hole 421 and the lower end of the sealing ball 41 are also in line contact and the contact area is small, the processing technology of the contact surface between the sealing ball 41 and the limiting hole 421 is small and the processing technology is simple.

[0050] Furthermore, the exhaust hole 422 is provided on the edge of the support plate 42 in the axial direction A to allow the air bubbles in the high pressure chamber H to pass through. The exhaust hole 422 may be provided in plurality, such as Figure 4 As shown, three exhaust holes 422 are provided along the circumferential direction at the edge of the support plate 42 . The three exhaust holes 422 are radially open exhaust holes 422 , which are more conducive to the discharge of bubbles in the high-pressure chamber H.

[0051] In some embodiments, as Figure 5 As shown, the outer wall of the housing 10 is provided with a spiral groove 13, the upper end of the spiral groove 13 is connected to the outside of the housing 10 (i.e., the environment inside the cylinder head), and the lower end of the spiral groove 13 is connected to the lower port 12 of the housing 10. The spiral groove 13 allows the oil outside the housing 10 to be replenished into the high-pressure chamber H.

[0052] When the shell 10 is processed, Figure 6 As shown, the shell blank is formed by cold forming, as shown in FIG. Figure 6 As shown in a, Figure 6 As shown in FIG. 2 , a spiral groove 13 is processed on the outer wall of the shell blank. The shell blank can be provided with multiple spiral parallel spiral grooves 13. Figure 6 As shown in c, the outer wall of the shell 10 can also be recessed to form a first annular liquid storage chamber 14 and a first annular groove 16. The first liquid storage chamber 14 is located in the middle of the shell 10 along the axial direction A, and the spiral groove 13 is divided into an upper spiral groove 131 and a lower spiral groove 132 along the axial direction A.

[0053] In this way, oil from the cylinder head's surroundings can flow through the upper spiral groove 131 into the first reservoir chamber 14. Once the first reservoir chamber 14 is filled with oil, it can be replenished into the high-pressure chamber H through the lower spiral groove 132. Therefore, without the need for an additional oil pump or an oil passage in the cylinder head, the first reservoir chamber 14 can increase the oil storage space. This not only ensures timely replenishment of oil into the high-pressure chamber H and prevents air from being drawn into the oil in the high-pressure chamber H, but also promotes oil circulation within the high-pressure chamber H, ensuring that fresh, bubble-free oil always enters the high-pressure chamber H. This prevents aging of the oil in the high-pressure chamber H, which could reduce the rigidity of the oil in the high-pressure chamber H and cause failure of the hydraulic lash adjuster 100.

[0054] Furthermore, after the spiral groove 13 is machined into the housing 10 blank, the outer and inner walls of the housing 10 need to be ground using a grinding tool to ensure that the inner wall of the housing 10 fits within the plunger 20, and the outer wall of the housing 10 fits within the required tolerances. In the related art, a grinding tool is provided with multiple grinding blades along its circumference, and the grinding tool rotates about a central axis to grind the outer wall of the rotating housing 10.

[0055] If a vertical groove is provided on the outer wall of the shell 10, the grinding knife cannot abut against the outer wall of the shell 10 when the grinding knife is aligned with the vertical groove on the outer wall of the shell 10. Therefore, the grinding knife is disconnected from the outer wall of the shell 10 in the circumferential direction. The momentary disconnection can easily cause the grinding knife to jump, resulting in a change in the position of the rotation center axis of the grinding knife. When the grinding knife touches the outer wall of the shell 10 again, it is easy to scratch the outer wall of the shell 10, causing the roughness of the outer wall of the shell 10 to fail to meet the requirements.

[0056] In the present disclosure, a plurality of spiral parallel spiral grooves 13 are provided on the outer wall of the housing 10, such as Figure 5 As shown, the length of the grinding blade of the grinding tool in the axial direction A can ensure that the grinding blade is always in contact with the outer wall of the shell 10 as the shell 10 rotates, avoiding sudden disconnection or jumping of the grinding blade during the grinding process, thereby ensuring the roughness requirements of the outer wall of the shell 10 and the tolerance requirements between the outer wall and the inner wall of the shell 10.

[0057] In some embodiments, a radially extending second through hole 15 is provided on the side outer wall of the housing 10, and a radially extending third through hole 22 is provided on the side outer wall of the plunger 20. The third through hole 22 forms a second liquid storage chamber 23 in the low-pressure chamber L, which extends upward from the third through hole 22 to the cylinder head, wherein the third through hole 22 is connected to the second through hole 15, so that the second liquid storage chamber 23 is connected to the first liquid storage chamber 14.

[0058] Specifically, when the cam is in the raised position, the cam squeezes the rocker arm to open the valve of the valve mechanism. At the same time, the raised position also squeezes the plunger 20 toward the lower end of the housing 10. The space of the high-pressure chamber H is reduced and the pressure rises. The return spring 50 is compressed, and the first valve assembly 30 is closed, so that the oil in the high-pressure chamber H is squeezed and leaked from the leakage gap between the housing 10 and the plunger 20. A part of the leaked oil flows back to the first liquid storage chamber 14 through the second through hole 15, and a small amount of oil leaks out of the housing 10.

[0059] In this way, the second through hole 15 can not only reduce the oil pressure in the leakage gap, but also recover the leaked oil in time, avoid excessive leakage of the oil in the high-pressure chamber H, and slow down the reduction speed of the oil in the high-pressure chamber H.

[0060] During the cam's base circle, the valve of the valve train is closed, that is, at the end of valve lift, the plunger 20 is no longer squeezed, and the axial pressure A applied to the upper end of the plunger 20 becomes less than the restoring force of the return spring 50. Therefore, the return spring 50 begins to return, pushing the plunger 20 upward, and the high-pressure chamber H expands. Under the oil pressure of the cylinder head environment, the first valve assembly 30 is forced to open, and the oil in the first reservoir 14 can be replenished to the high-pressure chamber H as quickly as possible through the lower spiral groove 132, the lower port 12 of the housing 10, and the first valve assembly 30.

[0061] However, the first liquid storage chamber 14 is connected to the second liquid storage chamber 23 via the second through hole 15 and the third through hole 22. Specifically, the upper end of the plunger 20 further includes a fourth through hole 24. Oil from the external environment surrounding the cylinder head 300 enters the low-pressure chamber L of the plunger 20 through the fourth through hole 24. After the low-pressure chamber L is filled with oil, the oil in the second liquid storage chamber 23 within the low-pressure chamber L can flow into the first liquid storage chamber 14 through the third through hole 22 of the plunger 20 and the second through hole 15 of the housing 10.

[0062] As can be seen, the first liquid reservoir 14 in the outer wall of the housing 10 communicates with the external environment of the cylinder head 300 via the upper spiral groove 131. Simultaneously, the first liquid reservoir 14 also communicates with the external environment of the cylinder head 300 via the second liquid reservoir 23. Therefore, both the second liquid reservoir 23 and the first liquid reservoir 14 within the low-pressure chamber L can collect and store air-free oil from the external environment of the cylinder head 300, significantly increasing the oil storage space available for the high-pressure chamber H. This further ensures sufficient and timely oil supply to the high-pressure chamber H, preventing air from being drawn into the high-pressure chamber H, which could reduce the rigidity of the oil within the high-pressure chamber H.

[0063] In addition, in some embodiments, a first annular groove 16 is provided on the side outer wall of the housing 10. The first annular groove 16 is located below the second through hole 15, giving the first liquid storage chamber 14 a stepped shape. By providing the first annular groove 16, the volume of the first liquid storage chamber 14 can be further increased while ensuring the strength of the housing 10.

[0064] In some embodiments, a second annular groove 17 is provided on the inner side wall of the housing 10, and a third annular groove 25 is provided on the outer side wall of the plunger 20. The third annular groove 25 partially overlaps with the second annular groove 17 in the axial direction A and encloses a third liquid storage chamber 26, wherein the second through hole 15 is provided at the second annular groove 17, and the third through hole 22 is provided at the third annular groove 25. Therefore, the third liquid storage chamber 26 is connected with the first liquid storage chamber 14 through the second through hole 15, and is connected with the second liquid storage chamber 23 through the third through hole 22, thereby further increasing the volume of the oil storage chamber supplying oil to the high-pressure chamber H.

[0065] like Figure 7 As shown, the volume of all oil storage spaces is shown, including the first liquid storage chamber 14 (such as Figure 7 As shown in the upper left figure) and the second liquid storage chamber 23 (as Figure 7 The volume of the third liquid storage chamber 26 (as shown in the lower left figure) Figure 7 The oil storage cavity also includes a liquid storage space formed by the lower port 12 of the housing 10 and the inner wall of the cylinder head (as shown in the upper right figure). Figure 7 The above oil storage spaces are combined to ensure that the amount of oil when replenishing the oil into the high-pressure chamber H is sufficient.

[0066] In some embodiments, as Figure 3 As shown, the hydraulic lash adjuster 100 includes a collar 60 , which is sleeved on the outside of the plunger 20 and located in the third fluid storage chamber 26 to limit the plunger 20 from separating from the housing 10 in the axial direction A.

[0067] In some embodiments, as Figure 3 As shown, the first valve assembly 30 includes a first check ball 31, a valve seat 32 and a first spring 33. The first check ball 31 abuts against the lower port 12, and the valve seat 32 is covered on the first check ball 31. A valve wing 34 is provided at the lower end of the valve seat 32. The lower end of the return spring 50 abuts against the upper end surface of the valve wing 34, so that the valve wing 34 always remains in abutment with the inner wall of the shell 10. The first spring 33 is located in the valve seat 32 and abuts between the upper end of the first check ball 31 and the inner wall of the valve seat 32, for supporting the first check ball 31 to open or close the lower port 12.

[0068] like Figure 8As shown, the valve seat 32 is provided with a communicating hole 321 communicating with the high-pressure chamber H. When the cam is in the base circle, the plunger 20 is no longer subjected to downward extrusion force, the return spring 50 is reset and the high-pressure chamber H expands. At this time, the high-pressure chamber H is in a negative pressure state, causing the oil pressure outside the housing 10 to be greater than the oil pressure in the high-pressure chamber H. However, the elastic force of the first spring 33 is much smaller than the elastic force of the return spring 50. Therefore, the pressure difference between the oil outside the housing 10 and the pressure of the oil in the high-pressure chamber H can only overcome the spring force of the first spring 33 of the first valve assembly 30 to push open the first check ball 31. The oil then enters the high-pressure chamber H through the communicating hole 321, completing the replenishment of the oil in the high-pressure chamber H.

[0069] In some embodiments, the plunger 20 may be integrally formed. Figure 3 As shown, the plunger 20 may include an upper plunger 27 and a lower plunger 28 that are separately provided. The lower plunger 28 may be in the shape of a bottle cap and include an upper end plate 281 that abuts against the lower end of the upper plunger 27 and forms the bottom wall of the low-pressure chamber L. The upper end plate 281 of the lower plunger 28 is provided with a first through hole 21. The second valve assembly 40 is located in the lower plunger 28. Therefore, when the air bubbles in the high-pressure chamber H can be discharged into the low-pressure chamber L through the second valve assembly 40 and the first through hole 21.

[0070] Furthermore, when the high-pressure chamber H is compressed, the oil in the high-pressure chamber H overflows from the gap between the piston and the inner wall of the housing 10 to the outside of the housing 10. A gap exists between the separately molded lower and upper pistons, allowing the overflowing oil to flow back into the low-pressure chamber L of the plunger 20. This allows the overflowing oil to be promptly recovered, preventing excessive leakage of the oil and slowing down the rate of reduction of the oil in the high-pressure chamber H. Furthermore, the separately molded plunger 20 has a simple structure and a simple production process, which can reduce costs.

[0071] In some embodiments, the hydraulic lash adjuster 100 can be applied to a valve mechanism, which can be an exhaust valve mechanism or an intake valve mechanism, without limitation. Figure 9 , which shows a partial structure of a valve mechanism in an embodiment of the present disclosure (the valve stem, spring, valve structure, etc. are not shown), and the valve mechanism may include a hydraulic lash adjuster 100 and a rocker arm 200 .

[0072] In the related art, the engine has a cylinder head 300 and a cylinder (not shown in the figure). The cylinder head 300 is used to seal the cylinder. A through tappet hole (not shown in the figure) is provided in the cylinder head 300. A push rod (also called a valve stem) is provided in the tappet hole. The engine is also provided with a camshaft (not shown in the figure). The camshaft has a cam. When the camshaft drives the cam to rotate, the cam drives the push rod to perform reciprocating linear motion in the tappet hole by driving the roller 70 of the rocker arm, thereby regularly opening and closing the intake valve and exhaust valve of the engine to supply combustible mixture to the cylinder and discharge exhaust gas in time, thereby meeting the intake and exhaust requirements of the engine.

[0073] The hydraulic lash adjuster 100 is a device that, when the valve mechanism is operating, uses the return spring 50 and the hydraulic pressure in the high-pressure chamber H to push the plunger 20 against the support end 80 of the rocker arm to eliminate the gap between the valve mechanism components, thereby ensuring that the cam can always abut against the roller 70 of the rocker arm to achieve valve opening and closing and avoid failure.

[0074] Furthermore, if Figure 9 As shown, the supporting end of the rocker arm is provided with an oil collecting hole 81, wherein the position of the oil collecting hole 81 corresponds to the fourth through hole 24 of the plunger 20, and the oil collecting hole 81 is connected with the low-pressure chamber L through the fourth through hole 24, so that the low-pressure chamber L is connected with the external environment of the cylinder head 300, and can collect oil from the environment around the cylinder head 300. The replenishment of fresh oil and the circulation of oil can also prevent oil aging and remove air in the oil in time, thereby increasing the rigidity of the oil in the high-pressure chamber H.

[0075] The specific manner in which the functions of the hydraulic lash adjuster 100 in the valve mechanism in the above embodiment are implemented has been described in detail in the embodiment of the hydraulic lash adjuster 100 and will not be elaborated on here.

[0076] It is understood that in this disclosure, "plurality" refers to two or more than two, and other quantifiers are similar. "And / or" describes the association relationship of related objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship. The singular forms "a", "the" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0077] It will be further understood that the terms "first," "second," and the like are used to describe various structures, but these structures should not be limited to these terms. These terms are merely used to distinguish structures of the same type from one another and do not indicate a particular order or degree of importance. In fact, the expressions "first," "second," and the like are fully interchangeable. For example, a first structure could also be referred to as a second structure, and similarly, a second structure could also be referred to as a first structure without departing from the scope of this disclosure.

[0078] It can be further understood that the terms "center", "longitudinal", "lateral", "front", "back", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation.

[0079] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered merely as exemplary, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0080] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the scope of the appended claims.

Claims

1. A hydraulic lash adjuster (100), characterized in that: include: A housing (10) including an upper port (11) and a lower port (12) along the axial direction; A plunger (20) is axially movable in the housing (10), wherein the inner cavity of the plunger (20) forms a low-pressure chamber (L), and the lower end of the plunger (20) and the lower port (12) of the housing (10) form a high-pressure chamber (H), and the lower end of the plunger (20) is further provided with a first through hole (21); a first valve assembly (30) located at the lower end of the high-pressure chamber (H) and abutting against the lower port (12) of the housing (10), allowing oil outside the housing (10) to enter the high-pressure chamber (H) from the lower port (12); a second valve assembly (40), located at the upper end of the high-pressure chamber (H), comprising a sealing ball (41) and a support plate (42), wherein the support plate (42) is located at the lower end of the sealing ball (41) and supports the sealing ball (41) to abut against the first through hole (21) of the plunger (20), allowing the oil and air bubbles in the high-pressure chamber (H) to enter the low-pressure chamber (L) through the first through hole (21); and A return spring (50) is axially supported between the support plates (42) of the first valve assembly (30) and the second valve assembly (40).

2. The hydraulic lash adjuster (100) according to claim 1, characterized in that The support plate (42) comprises: A limiting hole (421) is provided in the middle of the support plate (42), and the limiting hole (421) and the first through hole (21) jointly define the position of the sealing ball (41); An exhaust hole (422) is axially provided on the edge of the support plate (42) to allow air bubbles in the high-pressure chamber (H) to pass through.

3. The hydraulic lash adjuster (100) according to claim 1, characterized in that The outer wall of the housing (10) is provided with a spiral groove (13), the upper end of the spiral groove (13) is communicated with the outside of the housing (10), and the lower end of the spiral groove (13) is communicated with the lower port (12) of the housing (10), and the spiral groove (13) is used to allow oil outside the housing (10) to be replenished into the high-pressure chamber (H).

4. The hydraulic lash adjuster (100) according to claim 3, characterized in that The outer wall of the shell (10) is provided with an annular first liquid storage cavity (14), and the first liquid storage cavity (14) divides the spiral groove (13) into an upper spiral groove (131) (13) and a lower spiral groove (132) (13) along the axial direction.

5. The hydraulic lash adjuster (100) according to claim 4, characterized in that The outer side wall of the housing (10) is provided with a second through hole (15) which penetrates radially. The outer side wall of the plunger (20) is provided with a third through hole (22) which is radially through, and the third through hole (22) forms a second liquid storage chamber (23) in the low-pressure chamber (L) which extends upward from the third through hole (22) to the cylinder head, wherein the third through hole (22) is communicated with the second through hole (15) so that the second liquid storage chamber (23) is communicated with the first liquid storage chamber (14).

6. The hydraulic lash adjuster (100) according to claim 5, characterized in that A first annular groove (16) is provided on the side outer wall of the housing (10), and the first annular groove (16) is located below the second through hole (15), so that the first liquid storage cavity (14) is stepped.

7. The hydraulic lash adjuster (100) according to claim 5, characterized in that The housing (10) is provided with a second annular groove (17) on its inner side wall, and the plunger (20) is provided with a third annular groove (25) on its outer side wall. The third annular groove (25) partially overlaps with the second annular groove (17) in the axial direction and encloses a third liquid storage cavity (26). The second through hole (15) is arranged at the second annular groove (17), and the third through hole (22) is arranged at the third annular groove (25).

8. The hydraulic lash adjuster (100) according to claim 7, characterized in that The hydraulic lash adjuster (100) includes a collar (60) which is sleeved on the outside of the plunger (20) and located in the third liquid storage chamber (26) to limit the plunger (20) from axially separating from the housing (10).

9. The hydraulic lash adjuster (100) according to claim 1, characterized in that The first valve assembly (30) comprises: a first check ball (31), the first check ball (31) abutting against the lower port (12); a valve seat (32), the valve seat (32) bucklingly covers the first check ball (31), a valve wing (34) being provided at the lower end of the valve seat (32), the lower end of the return spring (50) abutting against the upper end surface of the valve wing (34) so ​​that the valve wing (34) and the housing (10) are kept in abutment, and the valve seat (32) is provided with a communicating hole (321) communicating with the high-pressure chamber (H); and The first spring (33) is located in the valve seat (32) and abuts between the upper end of the first check ball (31) and the inner wall of the valve seat (32), and is used to support the first check ball (31) to open or close the lower port (12).

10. The hydraulic lash adjuster (100) according to claim 1, characterized in that The plunger (20) comprises: an upper plunger (27)(20); and A lower plunger (28) (20), the lower plunger (28) (20) includes an upper end plate (281), the upper end plate (281) and the lower end of the upper plunger (27) (20) abut against each other to form the bottom wall of the low-pressure chamber (L), the upper end plate (281) of the lower plunger (28) (20) is provided with the first through hole (21), and the second valve assembly (40) is located in the lower plunger (28) (20).

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