JP2016205166A - Lash adjuster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lash adjuster capable of securing a sufficient amount of working fluid in a low pressure chamber, and capable of easily bleeding air from a high pressure chamber.SOLUTION: A plunger 12 is inserted into a body 11 to be reciprocated. A low pressure chamber 23 is demarcated in the plunger 12, and a high pressure chamber 27 is demarcated in the body 11 between a bottom wall 17 of the plunger 12 and it. A valve hole 22 is provided on the bottom wall 17, a top hole 21 is provided on a top of the plunger 12 at a coaxial position with the valve hole 22, and a valve element 28 and an energizing member are provided in the high pressure chamber 27. An oil supply pipe 30 for supplying working fluid to the low pressure chamber 23 is formed on a peripheral wall 18 of the plunger 12 in such a manner of penetrating therethrough. The oil supply pipe 30 projects upward in an arrangement state in the low pressure chamber 23, and is disposed at a position shifted from an axial path through which an air bleeding rod-like tool goes.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lash adjuster.

  The lash adjuster disclosed in Patent Document 1 is assembled to a cylinder head of a vehicle and adjusts a valve clearance by using hydraulic pressure of hydraulic oil, and includes a bottomed cylindrical cylinder (body) and a cylinder inside the cylinder. And a bottomed cylindrical plunger inserted so as to be reciprocally movable. A low pressure chamber is provided in the plunger, and a high pressure chamber is provided in the cylinder between the bottom wall (bottom wall) of the plunger. The bottom wall is provided with a valve port (valve hole), and the high pressure chamber has a valve unit (valve element) that can open and close the valve port and a first spring unit that urges the valve unit in the valve closing direction. (Biasing member) is provided.

  Moreover, the oil feeding pipe of the form which penetrates a surrounding wall part is attached to the plunger. The oil feeding pipe is arranged so as to protrude obliquely upward into the low pressure chamber, and its upper end reaches the vicinity of the top of the plunger. The hydraulic oil on the cylinder head side is sent and stored in the low pressure chamber of the plunger through the oil feed pipe. When the valve portion is separated from the valve port of the bottom wall due to the hydraulic pressure fluctuation, the hydraulic oil stored in the low pressure chamber is sent to the high pressure chamber through the valve port. In this case, the hydraulic oil in the low pressure chamber is stored up to a height position corresponding to the upper end of the oil feed pipe, so that a sufficient amount of hydraulic oil is secured in the low pressure chamber. As a result, it is possible to avoid a situation in which the air in the low-pressure chamber is sucked into the high-pressure chamber due to a shortage of hydraulic oil in the low-pressure chamber, and it is possible to cope with the inclined arrangement and downsizing of the lash adjuster.

JP 2005-2953 A

  By the way, in the case of this type of lash adjuster, an operation of extracting air mixed with the hydraulic oil in the high pressure chamber at the time of assembly or the like is performed so that the hydraulic pressure of the high pressure chamber is maintained at an appropriate value. When performing such an air venting operation, a rod-like jig elongated in the axial direction is usually used. The rod-shaped jig is inserted into the axial path in the plunger from the top hole provided at the top of the plunger, and further, the tip portion penetrates the valve port to face the high pressure chamber and comes into contact with the valve portion accommodated in the high pressure chamber. . Subsequently, the rod-shaped jig is pushed in, and the valve portion moves away from the valve port against the biasing force of the first spring portion, so that the air in the high-pressure chamber can be transferred from the valve port to the low-pressure chamber and removed. . However, according to the configuration of Patent Document 1, since the oil feeding pipe is provided in a form crossing the axial path through which the rod-shaped jig is inserted, even if the air venting operation using the rod-shaped jig described above is performed, The rod-shaped jig cannot interfere with the oil feed pipe and continue the work. For this reason, the air venting operation must be performed by a method other than the method using the bar-shaped jig, and the operation may be complicated.

  The present invention has been completed based on the above situation, and a lash adjuster that can secure a sufficient amount of hydraulic oil in the low-pressure chamber and can easily perform the air venting operation of the high-pressure chamber. The purpose is to provide.

  The present invention includes a cylindrical body and a cylindrical plunger inserted into the body so as to be reciprocally movable. A low pressure chamber is provided in the plunger, and a bottom wall of the plunger is provided in the body. A pressure hole is provided in the bottom wall, a top hole is provided at the top of the plunger at a position coaxial with the valve hole, and the high pressure chamber A valve body that can open and close the valve hole and a biasing member that biases the valve body in a valve closing direction are provided, and the valve body was stored in the low pressure chamber when the valve body was separated from the valve hole. The hydraulic oil flows from the valve hole to the high-pressure chamber, and the tip of the rod-shaped jig that passes through the valve hole from the top hole through the axial path in the plunger is the urging member. By pushing the valve body against the biasing force in the valve opening direction, A lash adjuster that can be pulled out, and a peripheral wall of the plunger is provided with an oil supply pipe for supplying hydraulic oil to the low pressure chamber, the oil supply pipe being connected to the low pressure chamber. It is characterized in that it protrudes upward in the arrangement state and is arranged at a position deviated from the axis in the plunger.

An oil supply pipe is provided through the peripheral wall of the plunger, and the oil supply pipe projects upward in the arrangement state in the low-pressure chamber, so that a sufficient amount of hydraulic oil can be stored in the low-pressure chamber up to the upper end of the oil supply pipe. it can. As a result, the situation in which the air in the low pressure chamber is sucked into the high pressure chamber is avoided, and it becomes possible to cope with the inclined arrangement and downsizing of the lash adjuster.
Further, since the oil supply pipe is disposed at a position away from the axial path in the plunger, the air venting operation of the high-pressure chamber can be easily performed without hindrance using a rod-shaped jig passed through the axial path.

It is sectional drawing showing the state in which the lash adjuster which concerns on Example 1 of this invention was integrated in the cylinder head. It is an enlarged view of the part corresponding to the lash adjuster of FIG. It is a figure showing the state which deform | transformed so that the oil supply pipe attached to the surrounding wall of the plunger in the penetrating state may be pressed with a deformation jig, and may evacuate from an axial path. FIG. 3 is a view corresponding to FIG. 2 in a lash adjuster according to a second embodiment of the present invention. FIG. 5 is a sectional view taken along line XX in FIG. 4.

Preferred embodiments of the present invention are shown below.
The oil supply pipe projects from the low pressure chamber with a projecting amount exceeding the inner peripheral radius of the plunger. According to this, the upper end of the oil supply pipe can reach a sufficiently high position in the arrangement state, and a situation where the hydraulic oil stored in the low pressure chamber is insufficient can be avoided.

  The oil supply pipe has a shape variability that is deformed so that it is pressed by a deformation jig inserted through the axis and retracted from the axis. According to this, an oil supply pipe | tube can be attached to a surrounding wall after shaping | molding of a plunger. As a result, before the oil supply pipe is attached, the plunger can be processed in advance such as heat treatment (carburizing, nitriding) or surface treatment (plating, DLC).

<Example 1>
A first embodiment of the present invention will be described with reference to FIGS. The first embodiment exemplifies a hydraulic lash adjuster 10 that is provided in the valve operating device 90 of the engine and automatically adjusts the valve clearance between the cam 80 and the rocker arm 70. The cylinder head 91 is assembled.

  As shown in FIG. 1, the valve gear 90 is for opening and closing the intake or exhaust port 92 of the cylinder head 91, and is provided integrally with a cam 80 that rotates in synchronization with the engine and the valve body 60. The valve stem 61, the rocker arm 70 that presses the valve stem 61 by swinging according to the rotation of the cam 80, and the lash adjuster 10 that supports one end of the rocker arm 70 so as to be swingable are provided.

  The valve stem 61 is inserted into a stem guide hole 93 connected to the intake or exhaust port 92 of the cylinder head 91, and the valve body 60 is urged by the coil spring 65 in a direction to close the intake or exhaust port 92. When the cam 80 rotates, the rocker arm 70 swings and the valve stem 61 reciprocates in the stem guide hole 93 so that the valve body 60 opens and closes the intake or exhaust port 92.

  The rocker arm 70 has one end supported by the lash adjuster 10, the other end abutted against the valve stem 61, and the cam 80 rotatably contacted with a roller 72 provided between the one end and the other end. Thus, the axis is arranged in a posture inclined with respect to the horizontal direction.

  The lash adjuster 10 is inserted in a posture inclined in the horizontal direction with respect to the bottomed mounting hole 95 provided in the cylinder head 91 and having a circular cross section. As shown in FIG. 2, the lash adjuster 10 includes a cylindrical body 11 and a cylindrical plunger that is inserted into the body 11 so as to be reciprocally movable in a vertical direction (specifically, a direction inclined with respect to the vertical direction). 12.

  As shown in FIG. 2, the body 11 includes a disk-shaped end wall 13 and a cylindrical wall 14 that rises from the outer peripheral edge of the end wall 13. On the outer peripheral surface of the cylindrical wall 14, a body circumferential groove 15 is recessed over the entire circumference. Further, the cylindrical wall 14 is provided with a body oil hole 16 having a circular cross section that opens in the inner surface of the body circumferential groove 15 so as to penetrate in the wall thickness direction (radial direction). A retainer 50 that restricts the plunger 12 from coming out of the body 11 is attached to the upper end opening of the cylindrical wall 14.

  As shown in FIG. 3, the plunger 12 includes a disk-shaped bottom wall 17 and a peripheral wall 18 that rises from the outer peripheral edge of the bottom wall 17. The upper end part of the surrounding wall 18 is comprised as the spherical part 19 of the form restrict | squeezed hemispherically. In a state in which the plunger 12 is inserted into the body 11, the ball portion 19 protrudes upward from the peripheral wall 18 of the body 11, and one end portion of the rocker arm 70 is slidably supported on the semispherical outer peripheral surface of the ball portion 19. It has come to be. For this reason, the ball portion 19 needs to have high hardness and wear resistance, and is subjected to processing such as heat treatment (carburization, nitriding) and surface treatment (plating, DLC).

  A top hole 21 having a circular cross section is provided through the central portion in the radial direction, which is the upper end portion of the sphere portion 19. In addition, a valve hole 22 having a circular cross section is provided in the center of the bottom wall 17 in the radial direction at a position coaxial with the top hole 21 in the vertical direction. The valve hole 22 and the top hole 21 are configured with substantially the same opening diameter.

  The inside of the plunger 12 is configured as a low pressure chamber 23 for storing hydraulic oil. An axial path along a virtual straight line 24 (see FIG. 3) connecting the top hole 21 and the valve hole 22 is provided at the center in the radial direction in the plunger 12. The axial path has a path diameter of a size corresponding to the top hole 21 or the valve hole 22, and a rod-like jig or a deforming jig 40 for venting air, which will be described later, is inserted therethrough.

  The outer peripheral surface of the peripheral wall 18 of the plunger 12 is slidable on the inner peripheral surface of the cylindrical wall 14 of the body 11, and as shown in FIG. 25 is recessed over the entire circumference. Further, the peripheral wall 18 is provided with a circular mounting hole 26 that opens in the inner surface of the plunger circumferential groove 25 so as to penetrate in the wall thickness direction (radial direction). An oil supply pipe 30 is attached to the attachment hole 26 by press fitting.

  The oil supply pipe 30 is a pipe made of metal such as copper or copper alloy, and has a shape variability deformed by receiving a bending load from the deformation jig 40 or the like as shown in FIG. After processing, it has shape retention to maintain a certain form. The oil supply pipe 30 is unevenly arranged on one side of both sides of the plunger 12 with the axial path therebetween. Specifically, the oil supply pipe 30 includes a press-fit portion 31 that is press-fitted and held along the radial direction in the mounting hole 26 of the peripheral wall 18, and an arc-shaped bent portion that is bent upward from the press-fit portion 31 toward the low-pressure chamber 23. 32 and a main body pipe portion 33 that rises from the bent portion 32 along the axial path and whose upper end reaches the vicinity of the top hole 21.

  One end opening of the press-fit portion 31 faces the inner surface of the plunger circumferential groove 25 of the peripheral wall 18 and is configured as an introduction end 34 that introduces hydraulic oil into the oil supply pipe 30. On the other hand, the upper end opening of the main body pipe portion 33 is configured as a lead-out end 35 that sends hydraulic oil that has passed through the oil supply pipe 30 to the low-pressure chamber 23. The main body pipe portion 33 is disposed to face the peripheral wall 18 with a slight gap between the main body pipe portion 33 and the inner peripheral surface of the peripheral wall 18, and has a protruding amount that exceeds at least the inner diameter of the plunger 12. The oil supply pipe 30 is configured with the same inner diameter dimension over the entire length.

  As shown in FIG. 2, the mounting hole 95 of the cylinder head 91 communicates with the oil supply hole 96, and the hydraulic oil supplied from the oil supply hole 96 includes the body circumferential groove 15, the body oil hole 16, the plunger circumferential groove 25, and the like. It is stored in the low pressure chamber 23 through the oil supply pipe 30.

  A high pressure chamber 27 defined by the end wall 13, the cylindrical wall 14, and the bottom wall 17 of the plunger 12 is provided in the body 11. The high-pressure chamber 27 includes a spherical valve body 28 that can open and close the valve hole 22, a cage 29 that holds the valve body 28, and a compression that is accommodated in the cage 29 and biases the valve body 28 toward the valve hole 22. A first spring 39 (biasing member) made of a coil spring and a second compression coil spring that is interposed between the outer peripheral edge of the cage 29 and the end wall 13 and urges the plunger 12 toward the rocker arm 70 side. A spring 38 is provided. The valve body 28 is configured to reciprocate so as to be able to contact and separate from the valve hole 22 in accordance with a pressure difference between the low pressure chamber 23 and the high pressure chamber 27. Then, when the valve body 28 moves away from the valve hole 22 against the urging force of the first spring 39, the hydraulic oil stored in the low pressure chamber 23 flows to the high pressure chamber 27 through the valve hole 22. It has become.

  Further, when the cam 80 rotates and the rocker arm 70 is pressed from the cam 80 side, the plunger 12 is pressed against one end of the rocker arm 70 and moves so as to sink into the body 11, and the hydraulic oil in the high pressure chamber 27 is moved. Is compressed, and the pressure in the high-pressure chamber 27 rises. Accordingly, some hydraulic oil in the high-pressure chamber 27 flows into the plunger circumferential groove 25 through between the inner peripheral surface of the cylindrical wall 14 and the outer peripheral surface of the peripheral wall 18. As a result, the entire length of the lash adjuster 10 is shortened by the amount of hydraulic oil flowing out. Further, the body 11 and the plunger 12 become rigid due to the pressure increase in the high pressure chamber 27, so that the lash adjuster 10 can properly support the rocker arm 70 at a predetermined position.

  When the pressure acting on the rocker arm 70 from the cam 80 side decreases with the further rotation of the cam 80, the plunger 12 rises due to the pressure of the high pressure chamber 27 and the biasing force of the second spring 38. Along with this, the pressure in the high pressure chamber 27 decreases, a pressure difference is generated between the high pressure chamber 27 and the valve body 28 opens against the urging force of the first spring 39. Simultaneously with the opening of the valve body 28, the hydraulic oil in the low-pressure chamber 23 flows into the high-pressure chamber 27, and the entire length of the lash adjuster 10 is extended by the flow amount. Thus, the state in which the lash adjuster 10 supports the rocker arm 70 at an appropriate position is secured, and the valve clearance between the cam 80 and the rocker arm 70 is adjusted to be substantially zero.

  By the way, when the engine is stopped, the supply of hydraulic oil to the low pressure chamber 23 is stopped. Therefore, when the lash adjuster 10 is inclined in the horizontal direction, a sufficient amount of hydraulic oil is secured in the low pressure chamber 23. There is a risk that it cannot be done. However, in the case of this embodiment, the hydraulic oil in the low pressure chamber 23 is stored up to a height position corresponding to at least the outlet end 35 of the main body pipe portion 33 of the oil supply pipe 30, so that a sufficient amount of hydraulic oil is stored in the low pressure chamber 23. Can be secured. Therefore, when the engine is subsequently started, a situation in which the air in the low pressure chamber 23 is sucked into the high pressure chamber 27 is avoided, and the hydraulic pressure in the high pressure chamber 27 is maintained at an appropriate value.

  On the other hand, when performing the operation of extracting the air mixed into the high-pressure chamber 27, a rod-shaped jig for air removal (not shown) is used. The rod-shaped jig is inserted into the low pressure chamber 23 in the plunger 12 through the top hole 21, and the distal end portion is inserted into the valve hole 22 through the path from the top hole 21. Further, the tip of the rod-shaped jig faces the high pressure chamber 27 and pushes down the valve body 28 against the urging force of the first spring 39, so that the valve hole 22 is opened and the air in the high pressure chamber 27 passes through the valve hole 22. It becomes possible to escape to the low pressure chamber 23. In the case of the present embodiment, since the oil supply pipe 30 is disposed at a position off the axial path through which the rod-shaped jig passes, the rod-shaped jig does not interfere with the oil supply pipe 30 and air using the rod-shaped jig is used. The punching operation can be performed without any problem.

  Further, at the time of assembly, the oil supply pipe 30 initially has a form extending linearly and is inserted into the mounting hole 26 of the molded plunger 12 from the outside. As shown in FIG. 3, a deformation jig 40 that penetrates the top hole 21 along the axial path from the valve hole 22 is inserted into the plunger 12 in advance. The deforming jig 40 has a cylindrical bar shape elongated in the vertical direction, and is configured in substantially the same form as the bar-shaped jig. The oil supply pipe 30 contacts the deformation jig 40 in the process of insertion, and is deformed so as to rise along the side surface of the deformation jig 40 as the insertion depth increases. Thereafter, the deforming jig 40 is pulled out from the plunger 12, and the oil supply pipe 30 is formed so that the main body pipe portion 33 is in a highly elevated state in the plunger 12.

  As described above, according to the present embodiment, the oil supply pipe 30 is provided through the peripheral wall 18 of the plunger 12, and the oil supply pipe 30 protrudes upward in the arrangement state in the low pressure chamber 23. A sufficient amount of hydraulic oil can be stored in the chamber 23 up to the outlet end 35 of the oil supply pipe 30. As a result, the situation in which the air in the low-pressure chamber 23 is sucked into the high-pressure chamber 27 is avoided, and the lash adjuster 10 can be accommodated in an inclined arrangement or downsized. Further, since the oil supply pipe 30 is disposed at a position away from the axial path in the plunger 12, the air venting operation of the high-pressure chamber 27 can be easily performed without hindrance using a rod-shaped jig passed through the axial path. it can.

  Further, since the linear oil supply pipe 30 is attached to the peripheral wall 18 of the molded plunger 12 and is forced to be bent and deformed by the deformation jig 40 to become a complete form of the oil supply pipe 30, before the oil supply pipe 30 is attached. The plunger 12 can be processed in advance such as heat treatment (carburizing, nitriding) or surface treatment (plating, DLC).

<Example 2>
4 and 5 show a second embodiment of the present invention. The second embodiment is the same as the first embodiment except that the configuration of the oil supply pipe 30A and the mounting hole 26A is different from that of the first embodiment. In the following, parts that are the same as or correspond to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and redundant description is omitted.

  26 A of attachment holes are made into the form which penetrates the surrounding wall 18 of the plunger 12 in the direction which cross | intersects a radial direction. The oil supply pipe 30A is a metal member that maintains a constant shape with higher rigidity than the oil supply pipe 30 of the first embodiment, and is configured to extend linearly as a whole. One end of the oil supply pipe 30 </ b> A is a press-fit portion 31 </ b> A that is press-fitted and held in the mounting hole 26 </ b> A of the peripheral wall 18. The total length of the oil supply pipe 30A is at least more than half the inner diameter (maximum inner diameter) of the plunger 12. In a state where the press-fit portion 31A is press-fitted into the mounting hole 26A of the peripheral wall 18, the oil supply pipe 30A is arranged so as to cross the plunger 12 at the same height in the height direction.

  However, the lash adjuster 10 </ b> A takes a posture inclined in the horizontal direction in the arrangement state. For this reason, the oil supply pipe 30 </ b> A is arranged with an upward inclination in the plunger 12 from the press-fit portion 31 </ b> A in the arrangement state, and the upper end thereof reaches the vicinity of the upper part of the peripheral wall 18. Here, as shown in FIG. 5, since the mounting hole 26 </ b> A penetrates in the direction intersecting the radial direction of the plunger 12, the oil supply pipe 30 </ b> A protruding into the plunger 12 is disengaged from the axial center of the radial direction. It will be arranged at the position.

  According to the second embodiment, the hydraulic oil in the low-pressure chamber 23 is stored up to a position corresponding to the lead-out end 35A of the oil supply pipe 30A, so that a sufficient amount of hydraulic oil can be secured in the low-pressure chamber 23. Further, since the oil supply pipe 30A is disposed at a position off the axis, the air venting operation of the high pressure chamber 27 can be performed using a bar-shaped jig for air venting. This is the same as in the first embodiment. On the other hand, in the case of the second embodiment, unlike the first embodiment, it is not necessary to bend the oil supply pipe 30A after attaching the oil supply pipe 30A to the peripheral wall 18 of the plunger 12, so that the number of processing steps can be reduced accordingly. it can.

<Other embodiments>
Hereinafter, other embodiments of the present invention will be briefly described.
(1) In the first embodiment, the oil supply pipe may be a resin pipe material having shape variability that is deformed by receiving a bending load.
(2) The lash adjuster may be always installed along the vertical direction. Also in this case, since the lash adjuster may be inclined in the horizontal direction in an arrangement situation such as a hill stop, the significance of applying the present invention is great.
(3) After attaching the oil supply pipe to the peripheral wall, the plunger may be processed into a completed form.

DESCRIPTION OF SYMBOLS 10, 10A ... Rush adjuster 11 ... Body 12 ... Plunger 17 ... Bottom wall 18 ... Circumferential wall 21 ... Top hole 22 ... Valve hole 27 ... High pressure chamber 28 ... Valve body 30, 30A ... Oil supply pipe 39 ... 1st spring (biasing member) )

Claims (3)

A cylindrical body and a cylindrical plunger inserted into the body so as to be reciprocally movable; a low pressure chamber is provided in the plunger; and the bottom wall of the plunger is provided in the body. A high-pressure chamber is provided, a valve hole is provided in the bottom wall, a top hole is provided on the top of the plunger at a position coaxial with the valve hole, and the valve hole is opened and closed in the high-pressure chamber. And a biasing member that biases the valve body in the valve closing direction, and when the valve body leaves the valve hole, the hydraulic oil stored in the low pressure chamber is The tip of the rod-shaped jig that passes through the valve hole from the top hole through the axial path in the plunger resists the biasing force of the biasing member. Then, the air mixed in the high-pressure chamber is removed by pushing the valve body in the valve opening direction. A lash adjuster that is possible theft is,
An oil supply pipe for supplying hydraulic oil to the low pressure chamber is provided through the peripheral wall of the plunger, the oil supply pipe protrudes upward in the arrangement state in the low pressure chamber, and an axial path in the plunger Rush adjuster, which is located at a position away from   2. The lash adjuster according to claim 1, wherein the oil supply pipe is disposed so as to project in the low pressure chamber with a projecting amount exceeding an inner peripheral radius of the plunger.   3. The lash according to claim 1, wherein the oil supply pipe has a shape variability that is deformed so that the oil supply pipe is pressed by a deformation jig inserted through the axis and retracted from the axis. Adjuster.

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