JP2009281170A - Hydraulic rush adjuster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To use oil splashed around in the periphery of a cylinder head without providing an oil passage on which hydraulic pressure accompanying driving of an oil pump on the cylinder head of an engine. <P>SOLUTION: This hydraulic rush adjuster is furnished with a body 38 stored in a recessed part 48 of the cylinder head 26 and a plunger 40 freely slidably inserted into the inside of the body 38. The inside of the plunger 40 is divided into a reservoir 66 and a high pressure chamber 68 by a bulkhead 70, and a valve hole 72 is formed on the bulkhead 70. A valve 42 to open and close the valve hole 72, a cage 44 to support the bottom surface side of the plunger 40, a coil spring 46 to support the lower part side of the cage 44 and a spring 82 to energize the valve 42 are arranged in the high pressure chamber 68. The through-holes 74, 76, 78, 80 are formed on the plunger 40, and the oil splashed around in the periphery of the cylinder head 26 is supplied to the reservoir 66 from the through-holes 74, 76 through a clearance 64. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lash adjuster, and more particularly to a hydraulic lash adjuster used for automatically adjusting a valve clearance of an internal combustion engine.

  As a valve mechanism of an internal combustion engine, for example, a rocker arm between a cam fixed to a camshaft that is driven to rotate in synchronization with the rotation of an automobile engine and a valve stem connected to an intake valve (or an exhaust valve) Are arranged so as to be swingable, and the drive force from the camshaft is transmitted to the valve stem via the cam and the rocker arm to open and close the intake valve (or exhaust valve).

  At this time, a hydraulic lash adjuster is arranged at a position serving as a fulcrum of the rocker arm, and the valve clearance between the cam and the rocker arm is automatically adjusted by driving the hydraulic lash adjuster (see Patent Document 1). ).

  In this hydraulic lash adjuster, when supplying hydraulic oil from an oil pump driven by the engine to the hydraulic lash adjuster, an oil temperature cooling means is provided in an oil supply passage connecting the oil pump and the hydraulic lash adjuster. A configuration is adopted in which the cooled hydraulic oil is supplied to the hydraulic lash adjuster to suppress the generation of bubbles in the hydraulic oil in the hydraulic lash adjuster.

JP 59-168209 A

  However, in the prior art, when supplying hydraulic oil from the oil pump driven by the engine to the hydraulic lash adjuster, a horizontal oil passage is provided in the cylinder head, and the hydraulic oil driven by the oil pump is supplied to the horizontal oil passage. Therefore, hydraulic oil must be supplied to the hydraulic lash adjuster, and the cost is increased by providing a horizontal oil passage in the cylinder head. In addition, when air enters the hydraulic oil in the middle of the horizontal oil passage and the mixed hydraulic oil is stirred in the hydraulic lash adjuster, a part of the air enters the pressure chamber (chamber containing the plunger spring). It is sent in and may impede the function of the hydraulic lash adjuster.

  The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to disperse around the cylinder head without providing an oil passage in the engine cylinder head in which the hydraulic pressure associated with the drive of the oil pump acts. It is an object of the present invention to provide a hydraulic lash adjuster that can use the obtained oil as hydraulic oil.

  In order to achieve the above object, a hydraulic lash adjuster according to claim 1 includes a cam fixed to a camshaft that is rotationally driven in synchronization with the rotation of the internal combustion engine, and a valve connected to an intake valve or an exhaust valve. In a hydraulic lash adjuster serving as a swing fulcrum of a rocker arm that is swingably disposed between a stem and a stem, the body is formed in a substantially cylindrical shape, and is formed in a substantially cylindrical shape so as to be slidable in the body. The body includes an inserted plunger, and the body is housed in a recess formed in an upper part of a cylinder head of the internal combustion engine, the opening side of the body facing the one end in the longitudinal direction of the rocker arm. Is formed with a partition that divides the inside of the plunger into a reservoir and a space between the body and a high-pressure chamber. The partition is connected to the reservoir and the high-pressure chamber. A valve hole is formed, and in the high-pressure chamber, a valve that opens and closes the valve hole, a cage that houses the valve and supports the partition wall, supports the cage lower side, and the plunger is located on the bottom side of the body A spring that biases the valve in a direction away from the cage, and a spring that biases the valve toward the valve hole is housed between the cage and the valve. The first through hole to be connected is formed.

  (Operation) Since the plunger has a first through hole that connects the inside and outside of the reservoir, oil scattered around the cylinder head can be supplied to the reservoir from the first through hole as hydraulic oil. For this reason, the oil scattered around the cylinder head can be used as the hydraulic oil without providing an oil passage in the engine cylinder head where the oil pressure associated with the driving of the oil pump is applied.

  In the lash adjuster according to claim 2, in the hydraulic lash adjuster according to claim 1, the first through hole includes an oil introduction hole that guides oil scattered around the cylinder head to the reservoir, and an inside of the reservoir. The air is also used as an air vent hole for discharging the air to the outside of the reservoir.

  (Operation) The first through-hole serves both as an oil introduction hole for guiding the oil scattered around the cylinder head to the reservoir and an air vent hole for discharging the air in the reservoir to the outside of the reservoir. Introduction and discharge of air in the reservoir can be performed smoothly.

  In a lash adjuster according to a third aspect, in the hydraulic lash adjuster according to the first aspect, the plunger has a through-hole different from the first through-hole so that the air in the reservoir is outside the reservoir. The second through-hole to be discharged is formed.

  (Function) The plunger is formed with a second through hole that discharges the air in the reservoir to the outside of the reservoir as a through hole different from the first through hole, so that the oil scattered around the cylinder head is operated. When oil is supplied from the first through hole to the reservoir, the oil can be smoothly introduced into the reservoir and the air in the reservoir can be discharged.

  In a lash adjuster according to a fourth aspect of the present invention, in the hydraulic lash adjuster according to the first aspect, the first through hole is formed to face a side wall of the body, and the inner peripheral side of the body and the plunger A gap connecting the space outside the body and the first through hole is formed between the outer peripheral side and the outer peripheral side.

  (Operation) The first through hole is formed opposite to the side wall of the body, and a gap connecting the space portion outside the body and the first through hole is formed between the inner peripheral side of the body and the outer peripheral side of the plunger. Thus, the oil scattered around the cylinder head can be reliably guided to the reservoir through the gap and the first through hole.

  In a lash adjuster according to a fifth aspect, in the hydraulic lash adjuster according to the first aspect, the first through hole is opposed to a through hole formed on a surface of the rocker arm facing the plunger. The plunger is formed on the surface facing the rocker arm.

  (Operation) Since the first through hole is formed on the surface of the rocker arm facing the rocker arm and facing the through hole formed on the surface facing the plunger, the first through hole is scattered around the cylinder head. Of the oil, the oil scattered on the upper part of the rocker arm can be guided from the through hole of the rocker arm to the reservoir through the first through hole.

  As is apparent from the above description, according to the first aspect, processing for providing an oil passage in the cylinder head is not required, so that the degree of freedom in design increases and the cost can be reduced. Further, it is possible to prevent the air mixed in the oil passage from being supplied to the reservoir or to stir the oil in the reservoir, and the function of the lash adjuster can be ensured over a long period of time.

  According to the second aspect, it is possible to smoothly introduce the oil into the reservoir and discharge the air in the reservoir.

  According to the third aspect, it is possible to smoothly introduce the oil into the reservoir and discharge the air in the reservoir.

  According to the fourth aspect, the oil scattered around the cylinder head can be reliably guided to the reservoir through the gap and the first through hole.

  According to the fifth aspect, of the oil scattered around the cylinder head, the oil scattered on the upper part of the rocker arm can be guided from the through hole of the rocker arm to the reservoir through the first through hole.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a valve operating apparatus for an internal combustion engine, FIG. 2 is a sectional view showing a first embodiment of a lash adjuster according to the present invention, and FIG. 3 is a second embodiment of a lash adjuster according to the present invention. FIG. 4 is a cross-sectional view showing a third embodiment of the lash adjuster according to the present invention, FIG. 5 is a cross-sectional view showing the fourth embodiment of the lash adjuster according to the present invention, and FIG. FIG. 7 is a cross-sectional view showing a sixth embodiment of the lash adjuster according to the present invention.

  In FIG. 1, a valve operating apparatus 10 for an internal combustion engine is fixed to a camshaft 12 that is driven to rotate in synchronization with the rotation of an automobile engine, for example, as a mechanism for opening and closing an intake port or an exhaust port connected to a combustion chamber. A cam 14, a valve stem 18 formed integrally with an intake valve (or exhaust valve) 16, and a compression coil wound around the valve stem 18 to apply a biasing force in the valve closing direction to the intake valve valve 16 A spring 20, a rocker arm 22 that is swingably disposed between the cam 14 and the valve stem 18, and a hydraulic lash adjuster 24 that is disposed at a position serving as a fulcrum of the rocker arm 22 are configured.

  The valve stem 18 is slidably inserted into a through hole 30 connected to an intake passage (or exhaust passage) 28 formed in a cylinder head 26 of the engine. The compression coil spring 20 is mounted between a concave portion 32 formed around the through hole 30 in the upper side of the cylinder head 26 and a retainer 34 fixed to the upper side of the valve stem 18. Thus, an elastic force for applying a biasing force in the valve closing direction to the intake valve 16 is accumulated.

  When the driving force accompanying the driving of the engine is transmitted from the camshaft 12 to the cam 14, the rocker arm 22 swings according to the rotation of the cam 14, and the driving force of the engine passes through the camshaft 12, the cam 14, and the rocker arm 22. The intake valve 16 opens and closes the intake port 36 (or the exhaust port) as the valve stem 18 slides.

  On the other hand, the hydraulic lash adjuster 24 includes a body 38, a plunger 40, a valve (ball) 42, a cage 44, and a coil spring 46, as shown in FIG.

  The body 38 is formed in a bottomed cylindrical shape and is housed in a cylindrical recess 48 formed on the upper side of the cylinder head 26. A small-diameter portion 50 having a smaller outer diameter than other parts is formed on the outer peripheral side of the upper portion of the body 38, and an annular retainer cap 52 that functions as a stopper for the plunger 40 is attached to the small-diameter portion 50. Has been. An annular stepped portion 54 is formed on the lower inner peripheral side of the body 38.

  The plunger 40 is formed in a substantially cylindrical shape, the upper side is closed, and the lower side is opened. The plunger 40 is slidably inserted along the longitudinal direction of the body 38 on the inner peripheral side of the body 38. The plunger 40 is divided into a large diameter portion 56, a step portion 58, a small diameter portion 60, and a circular head portion 62 according to the outer shape, and the step portion 58 having a smaller outer diameter than the large diameter portion 56 and A gap 64 serving as an oil passage is formed between the small diameter portion 60 and the body 38. The circular head 62 is mounted on the lower surface of the rocker arm 22 in the longitudinal direction end portion so as to be movable in a recess 22a formed in a substantially hemispherical shape.

  On the inner peripheral side of the lower portion of the large-diameter portion 56, a partition wall 70 is formed in an annular shape that divides the space portion on the inner peripheral side of the plunger 40 into a reservoir 66 and the body 38 into a high-pressure chamber 68. A valve hole 72 that connects the reservoir 66 and the high-pressure chamber 68 is formed. In the stepped portion 58, through holes 74 and 76 connected to the gap 64 are formed as oil introduction holes, and in the middle of the small diameter portion 60, through holes 78 and 80 are formed as air vent holes.

  In the high-pressure chamber 68, a valve 42 that opens and closes the valve hole 72, the valve 42 is housed, a cage 44 that supports the bottom surface side of the partition wall 70 of the plunger 40, and a coil spring 46 that supports the lower side of the cage 44, A spring 82 is disposed between the valve 42 and the cage 44 and biases the valve 42 in a direction to close the valve hole 72.

  The cage 44 is formed in a substantially bowl shape, and a valve 42 and a spring 82 are arranged inside thereof. The coil spring 46 is disposed between the flange 84 at the top of the cage 44 and the bottom surface of the body 38, and exerts an elastic force that urges the plunger 40 in a direction (vertically upward) away from the bottom surface of the body 38 via the cage 44. Accumulated.

  In the lash adjuster 24 having the above-described configuration, when the lash adjuster 24 is attached to the cylinder head 26, oil is injected as hydraulic oil into at least the region below the through holes 78 and 80 in the high pressure chamber 68 and the reservoir 66. Is satisfied. After the engine is started, oil scattered around the cylinder head 26 out of the oil supplied from the oil pump to the engine as the engine is driven is supplied to the reservoir 66 from the through holes 74 and 76 through the gap 64. The

  At this time, as the engine is driven, the cam 14 rotates, the rocker arm 22 swings in a direction to lower its operating point, and when the valve stem 18 is urged in the valve opening direction, the rocker arm 22 is compressed by the compression coil spring 20. The plunger 40 is pushed in the downward direction against the cam 14 by the elastic force. As a result, the pressure in the high pressure chamber 68 is increased, the oil in the high pressure chamber 68 becomes a rigid body, and the lash adjuster 24 serves as a fulcrum. At this time, the plunger 40 descends little by little while leaking a small amount of oil into the gap between the plunger 40 and the body 38.

  When the cam 14 further rotates in this state and the rocker arm 22 further urges the valve stem 18 in the valve opening direction, the intake valve 16 (or the exhaust valve) opens the intake port 36 (or the exhaust port), and the intake passage 28 (or an exhaust passage) communicates via an intake port 36 (or an exhaust port).

  On the other hand, after the intake port 36 (or the exhaust port) is opened, when the cam 14 further rotates and the valve stem 18 is urged in the valve closing direction by the elastic force of the compression coil spring 20, the rocker arm 22 is moved. The intake port 36 (or the exhaust port) is closed by the intake valve 16 (or the exhaust valve) while swinging in the direction of raising the action point.

  When the cam 14 further rotates in this state, the reaction force of the elastic force of the compression coil spring 20 disappears in the plunger 40, a gap is generated between the rocker arm 22 and the cam 14, and the biasing force of the coil spring 46 in the lash adjuster 24 The plunger 40 moves upward by the gap. At this time, a negative pressure is generated in the high pressure chamber 68, and the oil on the reservoir 66 side pushes down the valve 42 to enter the high pressure chamber 68, and the valve 42 is in a state where the pressure in the reservoir 66 and the pressure in the high pressure chamber 68 are balanced. Closes the valve hole 72 and enters a standby state.

  As described above, when the cam 14 rotates as the engine is driven, the rocker arm 22 swings with the lash adjuster 24 as a fulcrum, and the valve stem 18 descends or rises in response to the rocker arm 22 swinging. The intake port 36 can be opened and closed by the valve 16. In addition, when the engine is driven, the oil accompanying the drive of the oil pump scatters around the cylinder header 26, and a part of the scattered oil flows from the through holes 74 and 76 to the reservoir 66 via the gap 64. Supplied as

According to this embodiment, the oil scattered around the cylinder head 26 is supplied to the reservoir 66 from the through holes 74 and 76 via the gap 64 without providing an oil passage in the cylinder head 26. The following effects can be achieved.
(1) Processing for providing an oil passage in the cylinder head 26 is not necessary, and the degree of freedom in design increases and the cost can be reduced.
(2) It is possible to prevent air mixed in the oil passage from being supplied to the reservoir 66 or to stir the oil in the reservoir 66, and to ensure the function of the lash adjuster 24 for a long period of time. be able to.
(3) The reaction force due to the hydraulic pressure of the plunger 40 is eliminated, which can contribute to the reduction of friction and can improve fuel consumption.
(4) Since the oil scattered around the cylinder head 26 flows into the reservoir 66 when the engine is stopped and the oil supply port in the body 38 is not provided, the amount of oil in the reservoir 66 increases, so that the function of the lash adjuster 24 can be improved. The lash adjuster 24 can be downsized.
(5) Since oil pressure for supplying oil to the reservoir 26 is not required, the oil pump can be reduced in size, cost can be reduced, and fuel consumption can be improved.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the through holes 78 and 80 as air vent holes are removed from the plunger 40, the through hole 74 is used as an oil introduction hole, the through hole 76 is used as an air vent hole, and is lower than the through holes 74 and 76. The oil is stored in this area, and the other configuration is the same as that of the first embodiment.

  In this embodiment, by setting the region where the oil scattered around the cylinder head 26 gathers, particularly the region on the upper side of the through hole 74, the oil scattered around the cylinder head 26 passes through the gap 64. The reservoir 74 can be easily supplied from the hole 74. At this time, since more oil than the through hole 74 is not supplied to the through hole 76, the through hole 76 can be used as an air vent hole.

  According to the present embodiment, the same effects as those of the first embodiment can be obtained, and the through holes 78 and 80 need not be processed, so that the cost can be reduced accordingly.

  Next, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, the through holes 78 and 80 as air vent holes are removed from the plunger 40, the through holes 74 and 76 are used as oil introduction holes, and a through hole 86 as an air vent hole is formed at the center of the circular head 62. The oil is stored in a region below the through holes 74 and 76, and the other configuration is the same as that of the first embodiment.

  In this embodiment, by setting the region where the oil scattered around the cylinder head 26 gathers, particularly in the region on the upper side of the through holes 74 and 76, the oil scattered around the cylinder head 26 is passed through the gap 64. Thus, the reservoir 66 can be easily supplied from the through holes 74 and 76. At this time, the air in the reservoir 66 can be discharged to the outside of the reservoir 66 through the through hole 86.

  According to the present embodiment, the same effects as in the first embodiment can be obtained, and the air in the reservoir 66 can be easily discharged out of the reservoir 66 from the through hole 86 above the reservoir 66.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the through holes 78 and 80 as air vent holes are removed from the plunger 40, the through holes 74 and 76 are used as recycle oil introduction holes, and the air vent hole or reservoir supply oil is formed at the center of the circular head 62. A through hole 86 as an introduction hole is formed, an air vent hole or a through hole 88 as an oil introduction hole is formed at the center of the recess 22 a of the rocker arm 22, and oil is stored in a region below the through holes 74 and 76. The other configuration is the same as that of the first embodiment.

  In the present embodiment, by setting the region where the oil scattered around the cylinder head 26 gathers, in particular, the region around the through hole 88 of the rocker arm 22, the oil scattered around the cylinder head 26 is reduced to the through hole 88, It can be easily supplied to the reservoir 66 via 86.

  At this time, the air in the reservoir 66 can be discharged to the outside of the reservoir 66 through the through holes 86 and 88.

  According to this embodiment, the same effect as that of the first embodiment can be obtained, and the air in the reservoir 66 can be easily discharged to the outside of the reservoir 66 from the through holes 86 and 88 above the reservoir 66.

  Next, a fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the through holes 78 and 80 as air vent holes are removed from the plunger 40, the through holes 74 and 76 are used as air vent holes, and the air vent hole or oil introduction hole is formed at the center of the circular head 62. A through hole 86 is formed, and a through hole 88 as an air vent hole or oil introduction hole is formed at the center of the recess 22a of the rocker arm 22 so that oil is stored in a region below the through holes 74 and 76. The other configuration is the same as that of the first embodiment.

In the present embodiment, by setting the region where the oil scattered around the cylinder head 26 gathers, in particular, the region around the through hole 88 of the rocker arm 22, the oil scattered around the cylinder head 26 is reduced to the through hole 88, It can be easily supplied to the reservoir 66 via 86. The oil scattered around the cylinder head 26 is also supplied to the reservoir 66 from the through holes 74 and 76 through the gap 64.
At this time, the air in the reservoir 66 can be discharged to the outside of the reservoir 66 through the through holes 74 and 76 and can be discharged to the outside of the reservoir 66 through the through holes 86 and 88.

  According to this embodiment, the same effect as that of the first embodiment can be obtained, oil can be supplied to the reservoir 66 from the through holes 88 and 86 above the reservoir 66, and the air in the reservoir 66 can be supplied. The water can be discharged out of the reservoir 66 through the through holes 86 and 88 above the reservoir 66.

  Next, a sixth embodiment of the present invention will be described with reference to FIG. In this embodiment, the through holes 78 and 80 as air vent holes and the through holes 74 and 76 as oil introduction holes are removed from the plunger 40, and the air vent hole or oil introduction hole is penetrated at the center of the circular head 62. A hole 86 is formed, and a through hole 88 as an air vent hole or an oil introduction hole is formed at the center of the recess 22a of the rocker arm 22 so that oil is stored in a region below the through hole 86. Other configurations are the same as those of the first embodiment.

  In the present embodiment, by setting the region where the oil scattered around the cylinder head 26 gathers, in particular, the region around the through hole 88 of the rocker arm 22, the oil scattered around the cylinder head 26 is reduced to the through hole 88, It can be easily supplied to the reservoir 66 via 86.

  At this time, the air in the reservoir 66 can be discharged to the outside of the reservoir 66 through the through holes 86 and 88.

  According to this embodiment, the same effect as that of the first embodiment can be obtained, oil can be supplied to the reservoir 66 from the through holes 86 and 88 above the reservoir 66, and the air in the reservoir 66 can be supplied. The water can be discharged out of the reservoir 66 through the through holes 86 and 88 above the reservoir 66.

It is sectional drawing of the valve operating apparatus of an internal combustion engine. It is sectional drawing which shows 1st Example of the lash adjuster which concerns on this invention. It is sectional drawing which shows 2nd Example of the lash adjuster which concerns on this invention. It is sectional drawing which shows 3rd Example of the lash adjuster which concerns on this invention. It is sectional drawing which shows 4th Example of the lash adjuster which concerns on this invention. It is sectional drawing which shows 5th Example of the lash adjuster which concerns on this invention. It is sectional drawing which shows 6th Example of the lash adjuster which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Valve apparatus of internal combustion engine 12 Camshaft 14 Cam 16 Intake valve 18 Valve stem 20 Compression coil spring 22 Rocker arm 24 Rush adjuster 26 Cylinder head 38 Body 40 Plunger 42 Valve (ball)
44 Cage 46 Coil spring 66 Reservoir 68 High pressure chamber 74, 76, 78, 80, 86, 88 Through hole

Claims (5)

It becomes a swing fulcrum of a rocker arm that is swingably disposed between a cam fixed to a cam shaft that is driven to rotate in synchronization with the rotation of the internal combustion engine and a valve stem connected to an intake valve or an exhaust valve. In hydraulic lash adjuster,
A body formed in a substantially cylindrical shape, and a plunger formed in a substantially cylindrical shape and slidably inserted into the body,
The body is housed in a recess formed in an upper part of a cylinder head of the internal combustion engine, the opening side of which is arranged opposite to one end side in the longitudinal direction of the rocker arm.
In the plunger, a partition is formed that divides the inside of the plunger into a reservoir and divides the body into a high-pressure chamber,
The partition wall is formed with a valve hole connecting the reservoir and the high pressure chamber,
In the high-pressure chamber, a valve that opens and closes the valve hole, a cage that houses the valve and supports the partition wall, supports the cage lower side, and biases the plunger away from the body bottom side. A spring that is disposed between the coil spring and the cage and the valve, and biases the valve toward the valve hole,
The hydraulic lash adjuster, wherein the plunger is formed with a first through hole that connects the inside and outside of the reservoir.   2. The hydraulic lash adjuster according to claim 1, wherein the first through hole includes an oil introduction hole that guides oil scattered around the cylinder head to the reservoir, and air that discharges air in the reservoir to the outside of the reservoir. A hydraulic lash adjuster that is also used as a hole.   2. The hydraulic lash adjuster according to claim 1, wherein the plunger is formed with a second through hole that discharges air in the reservoir to the outside of the reservoir as a through hole different from the first through hole. 3. Hydraulic lash adjuster characterized by   2. The hydraulic lash adjuster according to claim 1, wherein the first through hole is formed to face a side wall of the body, and the body is disposed between an inner peripheral side of the body and an outer peripheral side of the plunger. A hydraulic lash adjuster characterized in that a gap connecting an external space and the first through hole is formed.   2. The hydraulic lash adjuster according to claim 1, wherein the first through hole is opposed to a through hole formed in a surface of the rocker arm facing the plunger, and is opposed to the rocker arm of the plunger. A hydraulic lash adjuster formed on a surface.

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