JPH094426A - Valve gear for internal combustion engine - Google Patents

Abstract

PURPOSE: To obtain certain and stable operation of intake/exhaust valves while improving connection rigidity of inner and outer cylinders and eliminate unstableness of operation of the intake/exhaust valves due to temporal abrasion of each sliding portion. CONSTITUTION: A valve lifter 18 composed of inner and outer cylinders 19, 20 is arranged between high and low speed cams 14, 14, 15 and a valve stem 13a of an intake valve 13. A pair of flat block type sliders 27, 27 are arranged between the outer cylinder 19 with which the high speed cam slides and the inner cylinder 20 with which the low speed cam slides, each slider 27 being slid in extending/contracting directions by relative pressure between hydraulic pressure of a hydraulic circuit 31 and force of a spring 40. The sliders 27, 27 are engaged with a stopper groove 24 for connecting the inner and outer cylinders 19, 20 to each other. A rash adjuster 41 is arranged inside the inner cylinder 20 for minutely adjusting valve clearance between the low speed cam 15 and the intake valve 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve operating system for variably controlling the opening / closing timing of an intake / exhaust valve of an internal combustion engine for an automobile and the valve lift according to the engine operating condition.

[0002]

2. Description of the Related Art As a conventional valve operating system of this kind, which variably controls the opening / closing timing of intake / exhaust valves and the valve lift amount, one disclosed in Japanese Patent Laid-Open No. 213607/1993 is known. .

The outline will be described with reference to FIG. 9. An intake valve 2 for each cylinder is provided inside a cylinder head 1, and a camshaft 3 supported by the upper end of the cylinder head 1 has a camshaft 3. A pair of left and right low speed cams 5 and 5 for opening the intake valve 2 via the valve lifter 4 and a high speed cam 6 arranged in the center of the two cams 5 and 5 are provided. The low-speed cams 5 and 5 have a narrow cam angle and a low lift, while the high-speed cam 6
Has a wide mountain and high lift.

The valve lifter 4 has a hydraulic chamber 7 formed at the center of a cylindrical lifter body 4a that slides in the holding hole 1a of the cylinder head 1. A hydraulic piston 8 whose upper surface is in sliding contact with the high-speed cam 6 is provided via a coil spring 9 so as to be vertically movable. In the lifter body 4a, the low speed cams 5 and 5 are in sliding contact with the upper surfaces on both sides of the hydraulic chamber 7, and the upper end surface of the valve stem 2a of the intake valve 2 is in contact with the center of the lower surface. There is.

Further, the hydraulic piston 8 is provided in the hydraulic chamber 7
It is adapted to be held in the raised position by the hydraulic pressure introduced therein via the hydraulic mechanism 9.

Since the hydraulic mechanism 9 does not supply the hydraulic pressure to the hydraulic chamber 7 at the time of engine startup and low rotation, the hydraulic piston 8 moves up and down in the lost motion state by the lift force of the high speed cam 6 to lifter body 4a. Lift force is not transmitted to. Therefore, only the low speed cams 5 and 5 enable the opening operation of the intake valve 2, and the rotation of the low speed cams 5 and 5 opens and closes the intake valve 2 via the lifter body 4a. As a result, the valve lift amount of the intake valve 2 is reduced and the opening / closing timing with a narrow opening angle is reached.

On the other hand, at the time of high rotation, hydraulic pressure is introduced into the hydraulic chamber 7 and the hydraulic piston 8 is held in the raised position. Therefore, the lift force of the high speed cam 6 is transmitted to the lifter body 4a by the hydraulic pressure in the hydraulic chamber 7 via the hydraulic piston 8 in preference to the low speed cams 5 and 5. Therefore, the intake valve 2 opens and closes according to the cam profile of the high speed cam 6, and the valve lift amount increases, and
It becomes a wide opening angle opening / closing timing, the valve overlap with the exhaust valve becomes large, and the output can be improved by improving the intake charging efficiency.

[0008]

However, in the above-mentioned conventional valve operating device, the lift transmission of the high-speed cam 6 to the lifter body 4a at the time of the high rotation is performed in the hydraulic chamber 7 supporting the hydraulic piston 8. Since the hydraulic pressure is used, the opening / closing operation of the intake valve 2 may become unstable.

That is, bubbles are often mixed in the hydraulic oil supplied into the hydraulic chamber 7 by the hydraulic mechanism 9, and therefore, the elastic compression of the hydraulic oil, that is, the sponge phenomenon, is caused by the bubbles. May occur. Therefore, the support rigidity of the hydraulic piston 8 due to the hydraulic pressure is reduced,
The natural frequency of the support system of the hydraulic piston 8 is lowered, and it becomes easy to resonate with the rotational vibration of the camshaft 3. As a result, there is a possibility that the intake valve 2 may cause an irregular movement to cause unstable behavior. In particular, at the time of high rotation, since the bubble generation rate is increased due to the vigorous stirring action of the hydraulic oil in the hydraulic mechanism 9, the above-mentioned problem becomes more remarkable.

Further, in this conventional example, the valve lifter 4 is of a direct acting type, and the lifter main body 4a contacting the low speed cams 5 and 5 directly pushes down the intake valve 2, so that the valve stem 2a and the lifter main body 4a. It is impossible to adjust the so-called valve clearance in consideration of zero or thermal expansion and wear due to the hydraulic pressure between and. As a result, the low speed cams 5, 5 and the valve lifter 4 and the valve stem 2
There is a possibility that the opening / closing accuracy of the intake valve 2 may be deteriorated due to the occurrence of wear between the parts a and the like.

[0011]

The present invention has been devised in view of the above problems of the prior art. The invention of claim 1 is provided on the outer periphery of a cam shaft rotatably driven by a crankshaft of an engine, A high-speed cam and a low-speed cam for operating the intake / exhaust valve and a holding hole formed in the cylinder head are slidably provided to transmit the lift of the high-low speed cam to the intake / exhaust valve. A slider provided between the inner and outer cylinders, the valve lifter being divided into an inner cylinder and an outer cylinder, each upper surface of which is in sliding contact with the corresponding high-speed cam and low-speed cam. It is characterized in that a connecting means for connecting or disconnecting the inner and outer cylinders is provided by being engaged with and disengaged from the radial direction in a stopper groove formed in one of the inner and outer cylinders.

The invention of claim 2 is characterized in that a lash adjuster for adjusting the valve clearance between the cam and the intake / exhaust valve is provided in the inner cylinder.

According to a third aspect of the present invention, the connecting means includes a stopper groove formed on the outer surface of the inner cylinder, a cylindrical holding member fixed to the inner surface of the outer cylinder, and the inside of the holding member. A flat block-shaped slider that slides in the formed rectangular cylinder in the radial direction to engage and disengage in the stopper groove, and an operating mechanism that slides the slider in the radial direction. There is.

According to a fourth aspect of the present invention, the actuating mechanism is provided on the inner surface of the slider and supplies hydraulic pressure to the thin plate ring-shaped spring member for sliding the slider in the radial direction and the cylinder. And a hydraulic circuit for sliding the slider in the direction of diameter reduction against the spring force of the spring member.

The invention of claim 5 is characterized in that hydraulic pressure is introduced into the lash adjuster through the hydraulic circuit.

[0016]

According to the first aspect of the present invention, for example, when the engine is running at low speed, the slider of the connecting means is held in the radial expansion position so that the inner and outer cylinders can slide relative to each other. Therefore, for example, the outer cylinder slidingly contacting the outer peripheral surface of the high-speed cam is in the lost motion state. Therefore, the inner cylinder that slides on the cam surface of the low speed cam moves up and down as the low speed cam rotates, and
The lift force is transmitted to the exhaust valve. For this reason, the intake / exhaust valve has a small valve lift amount and a narrow opening angle opening / closing timing.

On the other hand, at the time of high rotation, the slider of the connecting means slides in the radial direction at the position where the inner cylinder is most lowered in the outer cylinder, and the inner peripheral portion is engaged in the stopper groove, whereby the inner and outer cylinders are engaged. Are connected, and the inner and outer cylinders move up and down integrally. Therefore, when the outer cylinder moves up and down with the rotation of the high-speed cam having a large lift amount, this lift force is transmitted to the intake / exhaust valve via the inner cylinder. Therefore, the intake / exhaust valve has a large valve lift amount and opens and closes at a wide opening angle.

Further, as described above, since the inner and outer cylinders are connected to each other by engaging the slider with the stopper groove, the connecting rigidity of the inner and outer cylinders is increased, and the lift transmission to the intake and exhaust valves of the high speed cam is increased. Will be certain.

According to the second aspect of the present invention, since the valve clearances of the cams and the intake / exhaust valves can be constantly adjusted to zero by the lash adjuster, intake / exhaust due to wear of the sliding contact portions of the valve lifter or the like. It prevents the accuracy of valve opening / closing from decreasing.

According to the third aspect of the present invention, since the slider forming a part of the connecting means is formed in a flat block shape, the inertial mass is reduced and the engaging surface pressure with respect to the stopper groove is reduced, so that the stopper is formed. Wear on the inner surface of the groove is reduced.

According to the invention of claim 4, since the spring member for urging the slider in the radial direction is formed into a thin plate ring,
It is possible to make the accommodation space of the spring member sufficiently small.

According to the invention of claim 5, since the hydraulic pressure supply source of the lash adjuster also serves as the hydraulic circuit of the connecting means, the structure of the hydraulic circuit can be simplified.

[0023]

1 and 2 show an embodiment of a valve operating system of the present invention applied to the intake side of a multi-cylinder internal combustion engine, in which a cam shaft 12 has a cam bracket (not shown) at the upper end of a cylinder head 11. One cylinder is provided with one intake valve 13 for each cylinder that opens and closes the open end of the intake port.

The camshaft 12 includes an intake valve 13
Pair of high-speed cams 14 and 14 arranged so as to be located on both sides of the valve stem 13a, and both high-speed cams 1
One low speed cam 15 is integrally provided in the center between the four and four. The high speed cams 14, 14 are
The outer peripheral surface is set to have the same profile so as to have a large valve lift characteristic as shown by H in FIG. On the other hand, the low speed cam 15 has a profile such that the outer peripheral surface thereof has a small valve lift characteristic as indicated by L in FIG.

The intake valve 13 has a spring retainer 16 provided on the outer circumference of a cotter fixed to the stem end.
A valve lifter 1 that is urged in the closing direction by the spring force of a valve spring 17 elastically contacted with the valve lifter and is provided between the upper end surface of the stem end and each cam 14, 14, 15.
By means of 8, the lift force of each cam 14, 14, 15 is transmitted against the spring force of the valve spring 17.

The valve lifter 18 includes an outer cylinder 19 that slides up and down in a holding hole 11a formed in the cylinder head 11, and an inner cylinder 20 that is vertically slidable in the outer cylinder 19. It is configured.

As shown in FIG. 2, the outer cylinder 19 is made of a metal material and has a perfect circular cross section, and a circular guide hole 2 in which the upper end portion 20a of the inner cylinder 20 appears at the center of the upper wall 19a.
1 is formed so as to penetrate therethrough, and an annular projection 22 is provided on the inner peripheral surface on the upper side of the peripheral wall 19b. Also, the upper wall 19
The high-speed cam 1 is provided on the upper surfaces on both sides of the guide hole 21 of a.
The outer peripheral surfaces of 4 and 14 are in contact with each other.

As shown in FIG. 2, the inner cylinder 20 is in the shape of a closed cylinder having a perfect circular cross section, and the upper end 20a has a guide hole 2 formed therein.
An annular stopper groove 24 that forms a part of a connecting means described later is formed on the outer peripheral surface of the lower end portion 20b that is formed to have an outer diameter slightly smaller than the inner diameter of 1 and is formed to be thick.
A small-diameter air vent hole 23 is formed at the center of the disc-shaped top wall 20c, and the outer peripheral surface of the low speed cam 15 is in contact with the upper surface. A conical spring 32 that urges the inner cylinder 20 downward is mounted between the outer cylinder 19 and the inner cylinder 20.

The connecting means is composed of inner and outer cylinders 19 and 20.
1 is used for appropriately connecting or disconnecting
As shown in FIG. 3, an annular stopper groove 24 formed on the outer peripheral surface of the inner cylinder 20, a cylindrical holding member 25 fixed to the inner peripheral surface of the outer cylinder 19, and a holding member 25 of the holding member 25. A pair of rectangular cylinders 26, 26 formed in a direction perpendicular to the upper camshaft 12 axis, and a pair of sliders 2 slidably provided in the cylinders 26, 26 in the radial direction.
7, 27 and an operating mechanism for sliding the sliders 27, 27 in the radial direction.

In the stopper groove 24, the inner cylinder 20 is the outer cylinder 1
9, the sliders 27,
It is formed at a position corresponding to 27.

As shown in FIGS. 1 and 3, the holding member 25 has an annular portion 28 which is positioned and fixed to the annular projection 22 of the outer cylinder 19 and a step which is arranged below the width of the cylinders 26, 26. The stepped tubular portion 29 is formed with a tubular portion 29. The stepped tubular portion 29 has an annular lower end outer periphery and an upper end welded and fixed to the inner peripheral surface of the outer cylinder 19 in order to reduce the overall weight. ing.

As shown in FIGS. 1 and 3, the sliders 27, 27 are formed in a flat rectangular block shape and have the same shape as each other, and the inner surfaces 27b, 27b of the front end portions 27a, 27a facing each other are formed. 27b is stopper groove 2
4 and 24 are formed in an arc shape. Further, the diameter between the facing inner surfaces 27b, 27b is set to be slightly larger than the outer diameter of the lower end portion 20b of the inner cylinder 20 to allow the inner cylinder 20 to slide vertically.

Further, the actuating mechanism includes the sliders 2
A spring 30, which is a thin plate ring-shaped spring member, is elastically disposed on the inner surfaces 27b and 27b of the springs 7 and 27 to bias the sliders 27 and 27 in the radial direction, and the cylinders 26 and 2.
6, a hydraulic circuit 31 for supplying hydraulic pressure to move the sliders 27, 27 in the diameter reducing direction.

The hydraulic circuit 31 is formed in the cylinder block or the cylinder head 11, and has an oil passage 35 for supplying or discharging the working oil in the oil pan 33 via the oil pump 34 and the outer peripheral wall of the outer cylinder 19. And an annular groove 36 formed in the outer passage 19 and communicating with one end 35a of the oil passage 35.
A communication hole 37 which is formed through the peripheral wall 19b of the cylinder 21 in the radial direction to communicate the cylinders 26, 26 with the annular groove 36;
An electromagnetic switching valve 38 provided in the oil passage 35 is provided.

This electromagnetic switching valve 38 is adapted to switch between connecting the oil passage 35 or the other end 35b of the oil passage 35 and the drain passage 39, and a controller 40 for detecting an engine operating state. The switching operation is performed by a control signal (ON-OFF signal) from. The controller 40 detects the engine operating state based on information signals from various sensors such as a crank angle sensor, an air flow meter, and a water temperature sensor.

A lash adjuster 41 for adjusting the valve clearance between the intake valve 13 and the low speed cam 15 to zero is housed in the inner cylinder 20.

That is, this lash adjuster 41
Is a bottomed cylindrical body 42 press-fitted and fixed to the inner peripheral surface of the inner cylinder 20, a plunger 43 slidably provided inside the body 42, and a cap 44 for closing the upper end of the plunger 43. And a high pressure chamber 47 formed in the lower portion of the body 42 and separated by a check valve 45 from a reservoir 46 in the plunger 43.

A hydraulic pressure is supplied to the reservoir 46 by utilizing a part of the hydraulic circuit 31, and a supply passage 48 formed in parallel with the oil passage 35 is provided.
Has an upstream end connected between the oil pump 34 and the electromagnetic switching valve 38, and a downstream end connected to the end of the oil passage 35 on the side of the annular groove 36, and affects the operation of the connecting means midway. A diaphragm portion 49 is provided so as not to exist. The supply passage 48 includes a first through hole 50 formed in the outer cylinder 19, a second through hole 51 formed in the cylindrical portion 29, an inclined hole 52 formed in the inner cylinder 20, and an upper end of the body 42. The reservoir 46 communicates with the notch chamber 53 and a notch groove 54 at the upper end of the plunger 43. Further, as shown in FIG. 5, a slit 55 that connects the cutout chamber 53 and the air vent hole 23 is formed in the upper surface of the cap 44 along the diametrical direction.

Hereinafter, the operation of this embodiment will be described.
First, when the engine is started and in the low speed range, the controller 40
An OFF signal is output from the solenoid switching valve 38 to connect the oil passage 35 and the drain passage 39 to each other.
No hydraulic pressure is supplied to 6, 26. Therefore, the sliders 27, 27 are urged in the radial direction by the spring force of the spring 30 as shown in FIGS.
6 and 26 are held in a stored state. Therefore, the inner and outer cylinders 19 and 20 can be slid relative to each other without being connected. Therefore, as the high speed cams 14 and 14 rotate, the outer cylinder 19 slides vertically up and down, that is, in a lost motion state. On the other hand, as the low speed cam 15 rotates, the inner cylinder 20 moves up and down to move the lash adjuster 41. Through the low speed cam 15
Of the lift force is transmitted to the intake valve 13. Therefore, the intake valve 13 has a small valve lift amount and a delayed opening timing as shown by L in FIG. 8, which reduces the valve overlap with the exhaust valve.
As a result, backflow of burnt gas into the cylinder or the intake passage is prevented, and combustion can be improved especially at low rotation and low load.

On the other hand, when the low speed range is changed to the high speed range, the controller 40 outputs an ON signal to the electromagnetic switching valve 38 to close the drain passage 39 and communicate the oil passage 35. Therefore, hydraulic pressure is supplied into the cylinders 26, 26, and the high hydraulic pressure causes the sliders 2 to move.
7, 27 are moved in the diameter reducing direction against the spring force of the spring 30, as shown in FIG.

Then, when the inner cylinder 20 is maximally lowered when the low speed cam 15 is maximally lifted, each slider 27, 2 is moved.
The front end portions 27a, 27a of 7 advancely engage in the stopper groove 24, whereby the inner cylinder 20 and the outer cylinder 19 are integrally connected. Therefore, the inner and outer cylinders 19 and 20 move up and down together with the rotation of the high-speed cams 14 and 14, so that the cams 14 and 14
Is transmitted to the intake valve 13. Here, the low speed cam 15 is in sliding contact with the upper surface of the inner cylinder 20 during the base circle, but is separated from the upper surface during the lift and does not affect the lift action of the high speed cams 14, 14. Therefore, as shown in FIG. 8H, the intake valve 13 has a large valve lift amount and an early opening timing, which increases the valve overlap with the exhaust valve.
As a result, the intake charging efficiency is improved and the output can be increased.

Further, in the present embodiment, the hydraulic oil pumped from the oil pump 34 is controlled to a small amount by the throttle portion 49 and passes through the supply passage 48, the first and second through holes 50 and 51, the inclined passage 52, and the inclined passage 52. The reservoir 46 passes through the notch chamber 53 and the notch groove 54.
Since it is supplied inside, the clearance between the intake valve 13 and the low speed cam 15 by the lash adjuster 41 can always be adjusted to zero. As a result, even if the sliding parts of the valve lifter 18 and the like wear over time, a decrease in the opening / closing accuracy of the intake valve 13 is prevented.

When bubbles are mixed in the hydraulic oil in the hydraulic circuit 31, the bubbles float in the notch chamber 53 and flow into the slits 55, and from there, the air bubbles quickly pass to the atmosphere. Is discharged to. Therefore, the connecting means and the lash adjuster 41 can always operate reliably and stably.

Moreover, in this embodiment, the inner and outer cylinders 19 and 2 are
Since 0 is connected not by directly using hydraulic pressure but by engaging the sliders 27, 27 with the stopper groove 24, they are mechanically connected to each other,
The connection rigidity of is increased. Therefore, especially for high-speed cam 1
It is possible to reliably and stably transmit the lift force from the intake valves 4 and 14 to the intake valve 13 and prevent the intake valve from becoming unstable in behavior.

Further, since the main constituent parts of the connecting means are housed and arranged between the inner and outer cylinders 19 and 20, the valve lifter 18 is provided.
Can be prevented from increasing in size.

Further, since the sliders 27, 27 are formed of flat blocks, the inertial mass is reduced and the engaging surface pressure between the front end portions 27a, 27a and the inner surface of the stopper groove 24 is reduced. Therefore, it is possible to suppress the wear of the upper portion of the inner surface of the stopper groove 24. In addition, the sliders 27, 27
The two need only be opposed to each other in order to maintain balance, so that the structure of the connecting means can be simplified. In addition, each slider 2
If the circumferential lengths of the front end portions 27a, 27a of the Nos. 7, 27 are set to be larger, the engaging surface pressure can be further reduced.

Further, since the hydraulic circuit 31 of the connecting means is partially used also for the lash adjuster 41, the structure of the entire hydraulic circuit 31 can be simplified. Further, the holding member 25
Since the annular portion 28 and the tubular portion 29 are separately formed and the cylinders 26, 26 are formed between them, the molding work of each component is facilitated.

If a circular cam having a base circle is set instead of the low speed cam 15, a valve stop function can be obtained. Therefore, this can be applied to all intake valves and exhaust valves per cylinder. If applied, a cylinder deactivation function can be obtained. Further, in an engine having two intake valves per cylinder, the present invention is applied to one intake valve to perform a small lift operation in a low speed range to generate a strong intake swirl from the lift difference between the two intake valves. It becomes possible to improve combustion.

[0049]

As is apparent from the above description, claim 1
According to the described invention, the inner cylinder and the outer cylinder are mechanically connected by engagement of the slider of the connecting means and the stopper groove, instead of directly connecting the inner cylinder and the outer cylinder by using hydraulic pressure as in the conventional case. As a result, the lift force transferability from each cam to the intake / exhaust valves is improved, and reliable and stable operation of the intake / exhaust valves is obtained.

According to the second aspect of the present invention, since the valve clearance can be constantly adjusted to zero, the intake / exhaust valve can always be opened and closed with high accuracy even if the sliding portion such as the valve lifter is worn over time. Operation is obtained.

According to the third aspect of the present invention, since the slider is formed of a flat block, the inertial mass is reduced and the surface pressure of engagement with the stopper groove is reduced as compared with the case where the slider is formed in a cylindrical shape. It is possible to suppress wear between the slider outer surface and the stopper groove inner surface. Further, it is possible to suppress the increase in the size of the entire connecting means.

According to the fourth aspect of the present invention, since the spring member has a thin plate ring shape, the space for accommodating the spring member can be made sufficiently small, and the coupling mechanism can be made compact.

According to the fifth aspect of the present invention, by using the hydraulic circuit in common, the hydraulic circuit can be simplified as compared with the case where the hydraulic circuit of the connecting means and the hydraulic circuit of the lash adjuster are provided separately.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of a main part of this embodiment.

FIG. 3 is an exploded perspective view showing a part of the connecting means.

FIG. 4 is a sectional view taken along line AA of FIG. 1;

FIG. 5 is a perspective view of a cap used in this embodiment.

FIG. 6 is an operation explanatory view when the engine speed is low.

FIG. 7 is an explanatory view of the operation at the time of high engine speed.

FIG. 8 is a valve lift characteristic diagram of the present embodiment.

FIG. 9 is a sectional view showing a conventional valve train.

[Explanation of symbols]

 11 ... Cylinder head 12 ... Cam shaft 13 ... Intake valve 14 ... High speed cam 15 ... Low speed cam 18 ... Valve lifter 19 ... Outer cylinder 20 ... Inner cylinder 24 ... Stopper groove 25 ... Holding member 26 ... Cylinder 27 ... Slider 30 ... Spring 31 ... hydraulic circuit 41 ... lash adjuster

Claims (5)

[Claims] 1. A high-speed cam and a low-speed cam that are provided on the outer periphery of a cam shaft that is rotationally driven by a crank shaft of an engine to operate an intake / exhaust valve, and slide in a holding hole formed in a cylinder head. A valve lifter that is freely provided and transmits the lift of the high / low speed cam to the intake / exhaust valve, and the valve lifter is in sliding contact with the high speed cam and the low speed cam whose upper surfaces correspond to each other. The inner cylinder and the outer cylinder are formed separately, and the slider interposed between the inner cylinder and the outer cylinder is engaged and disengaged from the radial direction with the stopper groove formed in one of the inner cylinder and the outer cylinder to connect or disconnect the inner and outer cylinders. A valve operating device for an internal combustion engine, comprising: 2. A valve operating system for an internal combustion engine according to claim 1, wherein a lash adjuster for zero-adjusting a valve clearance between the cam and the intake and exhaust valves is provided in the inner cylinder. 3. The connecting means comprises a stopper groove formed on the outer surface of the inner cylinder, a cylindrical holding member fixed to the inner surface of the outer cylinder, and a rectangular shape formed inside the holding member. 2. A flat block-shaped slider that slides in the cylinder in the radial direction to engage and disengage in the stopper groove, and an actuating mechanism that slides the slider in the radial direction. 2. A valve train for an internal combustion engine according to item 2. 4. The actuating mechanism is disposed on the inner surface of the slider, and is a thin plate ring-shaped spring member that slides the slider in the radial direction, and hydraulic pressure is supplied to the cylinder to move the slider to the spring. 4. A valve operating system for an internal combustion engine according to claim 3, further comprising a hydraulic circuit that slides in a diameter reducing direction against a spring force. 5. The hydraulic pressure is introduced into the lash adjuster through the hydraulic circuit.
A valve gear for an internal combustion engine according to the above.