JP2015194094A - lash adjuster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lash adjuster which prevents air bite-in, and can easily perform the bleeding of a pressure chamber.SOLUTION: The inside of a plunger 12 inserted into a body 11 is inserted into a first oil chamber 37 and a second oil chamber 38 by a bulkhead part 13. A working fluid is supplied to the second oil chamber 38 from the first oil chamber 37 via a second check valve 40, and also supplied to a pressure chamber 25 from the second oil chamber 38 via the second check valve 40. The circulation of the working fluid to the first oil chamber 37 from the second oil chamber 38 is regulated by a first check valve 26. When the second check valve 40 is pushed down, a pressing part 47 extending toward the first check valve 26 side from the second check valve 40 side presses and valve-opens the first check valve 26, and the bleeding of the pressure chamber 25 can be thereby performed.

Description

  The present invention relates to a lash adjuster.

  As a valve mechanism of an internal combustion engine, a hydraulic lash adjuster that automatically adjusts the valve clearance may be used. For example, a lash adjuster disclosed in Patent Document 1 includes a bottomed cylindrical housing (body), a plunger that is inserted into the housing and can reciprocate within the housing, and a bottomless that is inserted into the plunger and fixed. It has a cylindrical partition (partition wall). The tip of the plunger functions as a rocking fulcrum of a rocker arm that opens and closes the valve.

A pressure chamber is provided at the bottom of the body between the bottom wall of the plunger. A valve hole is opened in the bottom wall of the plunger, and a first check valve is disposed in the valve hole so as to be openable and closable. The plunger is partitioned into a first oil chamber located outside by a inserted partition and a second oil chamber located inside. A communication hole for communicating the first oil chamber and the second oil chamber is provided at the tip of the partition wall, and the second check valve is disposed in the communication hole so as to be openable and closable at a position facing the first check valve. ing.
The hydraulic oil flowing through the hydraulic oil supply passage provided in the cylinder head is supplied to the first oil chamber through the supply holes provided in the housing and the plunger, and further supplied to the second oil chamber through the communication holes. Then, it is supplied to the pressure chamber through the valve hole. In this case, the first check valve allows the flow of the hydraulic oil from the second oil chamber to the pressure chamber, but restricts the flow of the hydraulic oil from the pressure chamber to the second oil chamber. On the other hand, the second check valve allows the flow of hydraulic oil from the first oil chamber to the second oil chamber, but restricts the flow of hydraulic oil from the second oil chamber to the first oil chamber.

  According to the above configuration, even if the entire lash adjuster is used in an inclined posture in which the tip of the plunger is directed downward, the hydraulic oil supplied to the second oil chamber by the second check valve is Leakage is prevented. For this reason, hydraulic oil is suitably stored in the second oil chamber, and air is prevented from entering the pressure chamber at the start, and as a result, it is possible to suppress degradation of the function of the lash adjuster due to air entrainment. Yes.

JP 2006-322438 A

  By the way, when assembling the lash adjuster, it is necessary to evacuate the pressure chamber when filling the pressure chamber with hydraulic oil. In this case, if the second check valve is not provided on the communication hole side of the partition wall, a rod-like jig for air bleeding is inserted into the partition wall through the communication hole from the discharge hole formed at the tip of the plunger. Can do. Then, the first check valve is pushed and opened by the tip of the rod-shaped jig inserted into the partition wall, and the pressure chamber air can be extracted from the valve hole, so that the second oil chamber operates through the valve hole. Oil can be supplied to the pressure chamber. However, in the above configuration, since the second check valve is provided on the communication hole side of the partition wall, the rod-shaped jig cannot be inserted into the partition wall through the insertion hole. It cannot be contacted. Therefore, according to the said structure, there exists a problem that it is difficult to air-release a pressure chamber.

  The present invention has been completed based on the above-described circumstances, and an object thereof is to provide a lash adjuster capable of easily venting a pressure chamber while preventing air from being caught. To do.

  The present invention includes a bottomed cylindrical body, a bottomed cylindrical plunger that is inserted into the body and can reciprocate within the body, and a partition wall portion that is inserted into the plunger and fixed. A pressure chamber is provided between the body and the bottom wall of the plunger, and a first oil chamber is provided between the peripheral wall of the plunger and the partition wall at the bottom of the body. A second oil chamber is provided in the partition wall, hydraulic oil is supplied to the first oil chamber, the second oil chamber, and the pressure chamber, and the second oil is provided on a bottom wall of the plunger. A first check valve is provided to allow the hydraulic oil to flow from the pressure chamber to the pressure chamber, but to restrict the flow of hydraulic oil from the pressure chamber to the second oil chamber, and the partition wall portion includes the first check valve. Flow of hydraulic oil from the first oil chamber to the second oil chamber at the top facing the one check valve A lash adjuster provided with a second check valve that restricts the flow of hydraulic oil from the second oil chamber to the first oil chamber, the first check valve being provided from the second check valve side. It has a form extending toward the valve side, and when the second check valve is pressed, the distal end portion in the extending direction includes a pressing portion that pushes and opens the first check valve. Have

  Even if the supply of the hydraulic oil into the plunger is stopped during the stop, the flow of the hydraulic oil from the second oil chamber to the first oil chamber is restricted by the second check valve. Hydraulic oil can be stored. Therefore, when hydraulic fluid flows from the second oil chamber to the pressure chamber at the time of subsequent startup, air is prevented from being mixed into the pressure chamber, and air entrapment is prevented. In addition, when the second check valve is pushed with a jig or the like during assembly, the pressing portion pushes the first check valve to open the first check valve. The hydraulic oil can be smoothly supplied to the pressure chamber. Therefore, even if there is a circumstance that the second check valve is installed at a position facing the first check valve, the pressure chamber can be easily vented from the second check valve side.

It is a longitudinal cross-sectional view of the lash adjuster which concerns on the Example of this invention. It is an enlarged view of the upper end part of FIG. It is the sectional view on the AA line of FIG. FIG. 3 is a diagram illustrating a state in which hydraulic oil flows from the first oil chamber to the second oil chamber in the state of FIG. 2 and the spring member is slightly contracted. It is a longitudinal cross-sectional view which shows the state which forcedly pushed the 2nd check valve with the jig | tool. It is a longitudinal cross-sectional view of the valve operating apparatus containing a lash adjuster. It is the schematic for demonstrating the air bleeding of the pressure chamber of a lash adjuster.

Preferred embodiments of the present invention are shown below.
The pressing portion is provided integrally with the second check valve. According to this, compared with a press part and a 2nd check valve being provided separately, the number of parts can be reduced and the workability | operativity at the time of an assembly | attachment can be aimed at.

  The second check valve is urged in a direction against the hydraulic pressure of the hydraulic fluid flowing through the second check valve, and the second check valve is closed in a resting state, and the second check valve is driven in a driving state. The valve is opened, and the pressing portion does not press the first check valve. Further, the first check valve is brought into the valve open state by forcibly pushing into the second check valve. Thus, the spring part in which the urging force is adjusted is provided. According to this, by adjusting the urging force of the spring portion, the valve opening and closing operations of the first check valve and the second check valve in each of the rest state, the drive state, and the assembled state are appropriately executed. can do.

  The spring portion is composed of a plurality of portions having different spring constants. According to this, it is not necessary to add a special structure to the spring portion, and the urging force can be adjusted with a simple configuration.

  A plurality of portions having different spring constants are arranged in series in the extending direction of the pressing portion. According to this, compared with the case where the several part from which a spring constant differs is arrange | positioned in parallel in the radial direction inside and outside, radial direction space can be made small and the enlargement of a lash adjuster can be avoided.

  The pressing portion is provided with a positioning portion that regulates misalignment of the shaft core portion that extends from the second check valve side toward the first check valve side. Since the misalignment of the shaft core portion of the pressing portion is regulated by the positioning portion, smoothness of the pressing operation of the pressing portion with respect to the first check valve is ensured.

<Example>
Embodiments of the present invention will be described with reference to the drawings. The lash adjuster 10 according to the embodiment is a hydraulic lash adjuster incorporated in the cylinder head 90, and is provided in the valve gear 80 of the automobile shown in FIG. In the following description, the vertical direction is based on each figure except for FIG. 3, but does not necessarily match the vertical direction during use.

  As shown in FIG. 6, a stem hole 91 is opened on the upper surface of the cylinder head 90. The stem hole 91 communicates with a vent hole 92 (intake port or exhaust port) of the cylinder head 90, and a valve 70 is mounted therein. The valve 70 can open and close the vent hole 92 and is biased in the valve closing direction by a valve spring 71. The upper end portion of the valve 70 protrudes upward from the upper end opening of the stem hole 91.

  A rocker arm 60 is disposed above the cylinder head 90. The rocker arm 60 has one end 61 supported by the lash adjuster 10 and the other end 62 in contact with the upper end of the valve 70. A roller 63 is rotatably attached to the central portion of the rocker arm 60, and the roller 63 is in contact with the cam 50 disposed above. The rocker arm 60 swings according to the rotation of the cam 50, whereby the valve 70 is opened and closed.

  The lash adjuster 10 is inserted into a mounting hole 93 opened on the upper surface of the cylinder head 90. The mounting hole 93 communicates with the oil supply path 94 of the cylinder head 90, and hydraulic oil flowing through the oil supply path 94 can flow into the mounting hole 93.

  As shown in FIG. 1, the lash adjuster 10 includes a body 11 that is inserted into the mounting hole 93, a plunger 12 that is inserted into the body 11, and a partition wall portion 13 that is inserted into the plunger 12. . The body 11 has a bottomed cylindrical shape, and includes a circular bottom wall portion 14 and a cylindrical peripheral wall portion 15 rising from the periphery of the bottom wall portion 14. An outer communication hole 16 is provided through the peripheral wall portion 15 of the body 11, and the outer communication hole 16 communicates with the oil supply path 94 through an attachment hole 93.

  As shown in FIG. 1, the plunger 12 has a bottomed cylindrical shape, and includes a circular bottom wall 17 and a cylindrical peripheral wall 18 rising from the periphery of the bottom wall 17. The peripheral wall 18 is integrally fixed to the outer peripheral edge of the bottom wall 17 by press-fitting or welding after the partition wall 13 is incorporated inside.

  The plunger 12 can be reciprocated in the vertical direction while being fitted into the body 11. The peripheral wall 18 of the plunger 12 is provided with a reduced diameter portion 19 having an outer peripheral surface recessed inward in the radial direction. The reduced diameter portion 19 is provided with an inner communication hole 21 therethrough. The inner communication hole 21 communicates with the outer communication hole 16 through a gap.

  As shown in FIG. 1, a substantially hemispherical support portion 22 that gradually decreases in diameter toward the upper end is provided at the upper end portion of the peripheral wall 18 of the plunger 12. The support portion 22 abuts on one end portion 61 of the rocker arm 60 and constitutes a rocking fulcrum of the rocker arm 60. A circular through hole 23 penetrating in the vertical direction is provided at the center (top) of the upper end of the support portion 22. The through-hole 23 has a form that expands upward.

  A circular valve hole 24 is provided through the central portion of the bottom wall 17 of the plunger 12. A pressure chamber 25 is defined in the bottom portion of the body 11 between the bottom wall portion 14 and the peripheral wall portion 15 of the body 11 and the bottom wall 17 of the plunger 12. A spherical check ball 27 constituting a first check valve 26 is disposed in the pressure chamber 25 of the plunger 12. The check ball 27 is accommodated in a bowl-shaped retainer 28. The retainer 28 accommodates a first spring 29 that biases the check ball 27 in a direction to close the valve hole 24. Further, the pressure chamber 25 accommodates a second spring 31 that comes into contact with the upper peripheral edge of the retainer 28 and the bottom wall 14 of the body 11. The plunger 12 is biased upward (in a direction protruding from the body 11) by the second spring 31.

  As shown in FIG. 1, the partition wall portion 13 is a pipe shape that is elongated in the vertical direction as a whole, and has a cylindrical large-diameter portion 32 along the vertical direction, and constricted upward from the upper end of the large-diameter portion 32. A tapered inclined portion 33, a cylindrical small-diameter portion 34 that extends long in the vertical direction from the upper end of the inclined portion 33, and a curved diaphragm that narrows upward from the upper end of the small-diameter portion 34. Part 35. A circular communication hole 36 penetrating in the up-down direction is provided at the center (top) of the upper end of the throttle portion 35.

  As shown in FIG. 1, the partition wall portion 13 is press-fitted into the peripheral wall 18 of the plunger 12, and the outer peripheral surface of the large diameter portion 32 is fixed to the plunger 12 by tightly contacting the inner peripheral surface of the peripheral wall 18 of the plunger 12. Is done. When the partition wall portion 13 is fixed to the plunger 12, the communication hole 36 and the through hole 23 are arranged so as to communicate coaxially in the vertical direction. A first oil chamber 37 is defined between the small diameter portion 34 and the inclined portion 33 of the partition wall portion 13 and the peripheral wall 18 of the plunger 12. The first oil chamber 37 is an annular path extending in the vertical direction, and the lower end is closed by the large diameter portion 32. On the other hand, a second oil chamber 38 is defined between the partition wall 13 and the bottom wall 17 of the plunger 12. The capacity of the second oil chamber 38 is larger than the capacity of the first oil chamber 37.

  The upper end of the partition wall 13 is located above the outer communication hole 16 and the inner communication hole 21, and the oil level height of the hydraulic oil stored in the second oil chamber 38 depends on the upper end position of the partition wall 13. It is prescribed. For this reason, even when the lash adjuster 10 is disposed with its axis inclined with respect to the vertical direction as in a V-type engine, it is possible to store sufficient hydraulic oil in the second oil chamber 38.

  A check valve body 39 and a spring portion 41 constituting the second check valve 40 are incorporated in the partition wall portion 13. As shown in FIG. 2, the check valve body 39 has a truncated conical shape with a diameter decreasing upward, and both upper and lower end surfaces are substantially horizontal flat surfaces 42 and 43. The check valve body 39 can be brought into and out of contact with the communication hole 36 of the partition wall portion 13 between the valve opening position and the valve closing position. As shown in FIG. 4, at the valve opening position, the check valve body 39 is separated below the communication hole 36, the communication hole 36 is opened, and the communication state between the first oil chamber 37 and the second oil chamber 38 is maintained. Maintained. On the other hand, as shown in FIG. 2, in the valve closing position, the check valve body 39 abuts on the lower end opening edge of the communication hole 36 to close the communication hole 36, and the first oil chamber 37 and the second oil chamber 38. The communication state with is interrupted.

  As shown in FIG. 1, the spring portion 41 is a compression coil spring and is arranged with its axis line directed in the vertical direction. The spring portion 41 is in contact with and supported by a peripheral portion of the lower flat surface 43 of the check valve body 39 in a state where the spring portion 41 is in contact with and supported by a plate-like support portion 44 protruding radially inward from the inner peripheral surface of the partition wall portion 13. ing. The check valve body 39 is urged upward by the spring portion 41 to close the communication hole 36.

  And the spring part 41 is comprised as a synthetic | combination spring which connected the 1st spring part 45 with a large spring constant located in the lower side, and the 2nd spring part 46 with a small spring constant located in the upper side in series in the up-down direction. Is done. The first spring portion 45 has a larger spring constant by making the number of turns within a predetermined pitch smaller than that of the second spring portion 46. In this embodiment, when the urging force (spring force) of the first spring portion 45 is S1, the urging force of the second spring portion is S2, and the hydraulic pressure generated in the plunger 12 when the engine is driven is P. , S2 <P <S1. Since the urging force of the spring portion 41 is set in this way, as will be described later, the first check valve 26 and the second check valve are respectively used when the lash adjuster 10 is assembled, when the engine is driven, and when the engine is stopped. 40 is guaranteed to operate properly.

  Further, as shown in FIG. 1, a pressing portion 47 is provided in the partition wall portion 13. The pressing portion 47 has a shaft core portion 48 that is elongated in a bar shape in the vertical direction, and the upper end of the shaft core portion 48 is integrally connected to the central portion of the lower flat surface 43 of the check valve body 39. The lower end of the shaft core portion 48 is located in the vicinity of the bottom wall 17 of the plunger 12 and above the top of the check ball 27 when the check valve body 39 is in the closed position by contacting the lower end opening edge of the communication hole 36. Spaced apart. The shaft core portion 48 is disposed at the central portion of the entire lash adjuster 10 including the partition wall portion 13, the plunger 12, and the body 11.

  A positioning portion 49 is integrally provided in the middle portion (specifically, the lower portion) in the extending direction of the shaft core portion 48. As shown in FIG. 3, the positioning portion 49 is configured by a plurality of (specifically four) blade portions 49A extending radially from the shaft core portion 48, and each blade portion 49A is arranged at equal intervals in the circumferential direction. Has been. The tip of each blade portion 49 </ b> A is disposed at a position close to the inner peripheral surface of the partition wall portion 13. Here, when the shaft core portion 48 of the pressing portion 47 is swung and tends to tilt, the tip of the blade portion 49 </ b> A comes into contact with the inner peripheral surface of the partition wall portion 13, so that the shaft core portion 48 is more than that. Misalignment is prevented. Therefore, the shaft core portion 48 is maintained in an appropriate posture along the shaft core direction by the positioning portion 49. The space between the blade portions 49 </ b> A serves as a passage for hydraulic oil flowing through the second oil chamber 38.

Next, an operation for bleeding the pressure chamber 25 of the lash adjuster 10 will be described.
The plunger 12, the partition wall portion 13, the first check valve 26, the retainer 28, the first spring 29, the second spring 31, the second check valve 40, and the spring portion 41 are assembled inside the body 11. Then, the assembled lash adjuster 10 is put into a container 50 in which hydraulic oil (hereinafter also referred to as engine oil 51) is stored (see FIG. 7). Next, a rod-shaped air bleeding jig J is inserted into the plunger 12 through the through hole 23 (see FIG. 5). Then, the tip of the jig J comes into contact with the upper flat surface 42 of the check valve body 39, and the check valve body resists the biasing force of the entire spring portion 41 (both the first spring portion 45 and the second spring portion 46). 39 is forced downward. At this time, in addition to the second spring portion 46, the spring portion 41 also contracts the first spring portion 45.

  When the check valve body 39 is strongly pushed by the jig J, the entire spring portion 41 is almost contracted, and the lower end of the pressing portion 47 provided integrally with the check valve body 39 is in contact with the upper end of the top portion of the check ball 27. In contact therewith, the check ball 27 is pushed downward against the urging force of the first spring 29. Then, the engine oil 51 in the container 50 is supplied into the plunger 12 through the outer communication hole 16 and the inner communication hole 21 in order. The hydraulic oil supplied into the plunger 12 is supplied from the first oil chamber 37 to the second oil chamber 38 through the communication hole 36 and further supplied to the pressure chamber 25 through the valve hole 24. At this time, the check ball 27 is pushed down to open the valve hole 24 and the pressure chamber 25 communicates with the second oil chamber 38, so that the hydraulic oil can be smoothly poured into the pressure chamber 25 from the valve hole 24. . When the refueling operation is completed in this way, the pressing state by the jig J is released. Then, the check valve body 39 is urged and raised by the spring portion 41, and the communication hole 36 is closed and kept in a closed state (see FIG. 1). Note that the air bleeding jig J used above may be a simple bar, and does not require a special one.

  When the engine is driven, the hydraulic pressure of the hydraulic oil flowing through the communication hole 36 from the first oil chamber 37 to the second oil chamber 38 overcomes the urging force of the second spring portion 46, and the check valve body 39 is pushed down by the hydraulic pressure. As a result, the valve 36 is opened (see FIG. 2). At this time, the lower end of the pressing portion 47 is still arranged away from the check ball 27, and the pressing portion 47 does not contact the check ball 27. Further, when the engine is driven, the plunger 12 is reciprocated in the vertical direction in the body 11 by the opening and closing operation of the first check valve 26 based on the hydraulic pressure fluctuation of the hydraulic oil, so that the fulcrum height of the rocker arm 60 is increased. Is adjusted to the proper position. During this time, the pressing portion 47 maintains a state where it does not come into contact with the check ball 27, so that the original function of the lash adjuster 10 that automatically adjusts the valve clearance is exhibited without any problem.

  Further, when the engine is stopped (when driving is stopped), the hydraulic oil is not supplied and the hydraulic oil does not flow through the communication hole 36. Therefore, the check valve body 39 is urged by the spring portion 41 and rises. The communication hole 36 is closed and kept in the closed state again (see FIG. 1). Therefore, sufficient hydraulic oil is stored in the second oil chamber 38 even during a pause, and the second oil chamber 38 is connected to the pressure chamber via the valve hole 24 at the next start-up (at the start of driving). It is possible to prevent air from entering 25.

  Thus, according to the present embodiment, the plunger 12 is partitioned into the first oil chamber 37 and the second oil chamber 38 by the partition wall 13, and the working oil flows from the second oil chamber 38 to the pressure chamber 25. In addition to the first check valve 26 that restricts the flow of hydraulic oil from the pressure chamber 25 to the second oil chamber 38, the hydraulic oil from the first oil chamber 37 to the second oil chamber 38 is provided. However, since the first check valve 40 that restricts the flow of the hydraulic oil from the second oil chamber 38 to the first oil chamber 37 is provided, the hydraulic oil is supplied from the second oil chamber 38 during the pause. It is prevented from flowing out. As a result, air can be effectively prevented from being caught in the pressure chamber 25 at the time of starting after the stop.

  Further, when the lash adjuster 10 is assembled, the pressing part 47 is lowered together with the first check valve 40 by pressing the air releasing jig J against the first check valve 40, and the check ball 27 of the first check valve 26. Is forcibly pushed in the valve opening direction, the valve hole 24 is opened, and the pressure chamber 25 can be easily vented.

  In the case of the present embodiment, the spring portion 41 that urges the first check valve 40 in the valve closing direction makes the first check valve 40 closed in the resting state and the first check valve 40 in the driving state. It is possible to bring the 1 check valve into the open state by opening the valve and not pressing the first check valve 26 and pressing the first check valve 26 forcibly. The biasing force has been adjusted to make it possible. For this reason, the valve opening and closing operations by the first check valve 26 and the first check valve 40 in each of the above-described assembly, driving, and resting periods are simply adjusted by adjusting the biasing force of the spring portion 41. Can be implemented simply and properly. In addition, since the spring portion 41 is merely composed of the first spring portion 45 and the second spring portion 46 having different spring constants, the configuration can be simplified.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following aspects are also included in the technical scope of the present invention.
(1) The pressing unit and the second check valve may be provided separately, and when the second check valve is pressed, the pressing unit may be pressed in contact with the second check valve.
(2) The lower end of the partition wall may be in contact with the bottom wall of the plunger, and the first oil chamber may be partitioned by the bottom wall together with the peripheral wall of the plunger.
(3) The plunger may be formed such that the bottom wall and the peripheral wall are integrally formed, and the upper end portion is deformed by diameter reduction after the partition wall portion is inserted from above.
(4) The spring portion may be configured such that a portion having a large spring constant and a portion having a small spring constant are integrally and continuously provided by a single spring material.
(5) The spring constant may be adjusted by a plurality of portions having different wire diameters.
(6) The spring portion may have a configuration in which the spring constant changes over three stages or more.
(7) The spring portion may be configured to gradually change without clearly distinguishing portions having different spring constants.
(8) An umbrella-shaped extended portion that protrudes radially outward may be provided at the lower end of the pressing portion, and the extended portion may press the check ball of the first check valve. As a result, the check ball is stably pushed by the extension portion.
(9) The second check valve may take any shape, and may be in the form of a sphere, for example, like the check ball.

DESCRIPTION OF SYMBOLS 10 ... Rush adjuster 11 ... Body 12 ... Plunger 13 ... Bulkhead part 17 ... Bottom wall 18 ... Perimeter wall 24 ... Valve hole 25 ... Pressure chamber 26 ... First check valve 37 ... First oil chamber 38 ... Second oil chamber 40 ... First 2 Check valve 41 ... Spring portion 45 ... First spring portion 46 ... Second spring portion 47 ... Pressing portion 48 ... Shaft core portion 49 ... Positioning portion 90 ... Cylinder head

Claims (6)

A bottomed cylindrical body, a bottomed cylindrical plunger inserted into the body and capable of reciprocating in the body, and a partition wall portion inserted and fixed in the plunger,
A pressure chamber is provided between the body and the bottom wall of the plunger, and a first oil chamber is provided between the peripheral wall of the plunger and the partition wall at the bottom of the body. A second oil chamber is provided in the partition wall, hydraulic oil is supplied to the pressure chamber, the first oil chamber, and the second oil chamber, and a bottom wall of the plunger is provided from the second oil chamber. A first check valve is provided that permits the flow of hydraulic oil to the pressure chamber but restricts the flow of hydraulic oil from the pressure chamber to the second oil chamber, and the partition wall includes the first check valve. The flow of hydraulic oil from the first oil chamber to the second oil chamber is allowed at the top facing the valve, but the flow of hydraulic oil from the second oil chamber to the first oil chamber is restricted. 2 Rush adjuster with check valve,
The second check valve is configured to extend from the second check valve side toward the first check valve side, and when the second check valve is pushed, the leading end in the extending direction pushes the first check valve to open. A lash adjuster characterized by comprising a pressing portion to be valved.   The lash adjuster according to claim 1, wherein the pressing portion is provided integrally with the second check valve.   The second check valve is urged in a direction against the hydraulic pressure of the hydraulic fluid flowing through the second check valve, and the second check valve is closed in a resting state, and the second check valve is driven in a driving state. The valve is opened, and the pressing portion does not press the first check valve. Further, the first check valve is brought into the valve open state by forcibly pushing into the second check valve. The lash adjuster according to claim 1, further comprising a spring portion having an adjusted urging force.   The lash adjuster according to claim 3, wherein the spring portion includes a plurality of portions having different spring constants.   The lash adjuster according to claim 4, wherein the plurality of portions having different spring constants are arranged in series in the extending direction of the pressing portion.   6. The pressing portion is provided with a positioning portion that regulates misalignment of a shaft core portion that extends from the second check valve side toward the first check valve side. The lash adjuster according to any one of claims.

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