JPH09166006A - Variable valve system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly actuate a connecting means for transmitting a rotational force from a camshaft to a cam in a variable valve mechanism for changing the rotational speed of the cam during one rotation. SOLUTION: The rotation of a first rotational member 2 is transmitted through a middle member 6 to a second rotational member 3. A rotational phase with the first rotational member 2 is imparted from a control shaft 10 through a eccentric spacer 4 to the second rotational member 3 according to the operational condition of an internal combustion engine. The second rotational member 3 opens/closes valve members 16 and 17 via locker arms 14 and 15 according to the rotational phase. The second rotational member 3 sets the valve opening periods of the valve members 16 and 17 short during the low speed running of the internal combustion engine and long during the high speed running thereof. One of connecting means for connecting the middle member 6, the second rotational member 3 to each other is used as a guiding groove 3c and the other is used as a slider 9 for sliding the guiding part 3c and the advancing direction edge of this slider 9 is chamfered or R machined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve mechanism capable of changing the opening / closing timing of intake / exhaust valves according to the operating state of an internal combustion engine.

[0002]

2. Description of the Related Art There is a variable valve mechanism in which the opening / closing timings of intake / exhaust valves are changed in order to increase the torque at low / medium speeds of an internal combustion engine and increase the output at high speeds. As such a variable valve mechanism, for example, Japanese Patent Publication No. 47-20
No. 654, JP-A-5-202718, and JP-A-6-32.
There is an intake / exhaust valve drive control device for an internal combustion engine disclosed in Japanese Patent No. 3114.

For example, the variable valve mechanism disclosed in Japanese Patent Laid-Open Nos. 5-202718 and 6-323114 is shown in FIG.
As shown in FIG. 10, a cam shaft 31 is arranged coaxially with a drive shaft 30 that rotates synchronously with a crank shaft of an internal combustion engine, and a flange 31a provided at one end of the cam shaft 31 and a drive shaft 30 are provided. An annular disc 35, which is swingable about the axis of the drive shaft 30 via a disc housing 34, is interposed between a flange 32a provided at one end of the connected and fixed sleeve 32. The tip ends 36a and 37a of a pair of pins 36 and 37 that are rotatably provided on the flange 35 (another member) are connected to the flange 31.
a, 32a each engaging groove (guide portion) provided in the radial direction
31b and 32b are slidably fitted (see FIGS. 9 and 1).
0), the upper portion of the disk housing 34 that rotatably supports the annular disk 35 is provided with an eccentric cam 38, and the control shaft 3
It is configured such that the shaft 9 is rotatably supported on the shaft 9.

Rotational force of the crankshaft is transmitted from the drive shaft 30 through an annular disc 35 which is eccentrically rotated to the camshaft 31.
Is transmitted to Control shaft 39 depending on the operating state of the engine
When is rotated, the annular disc 35 is swung accordingly via the eccentric cam 38 and the disc housing 34, and the rotational phase of the cam shaft 31 with respect to the drive shaft 30 is displaced by the pins 36 and 37. That is, 1 of the camshaft 31
The rotation speed changes during rotation. As a result, the opening / closing timing of the intake / exhaust valve of the engine changes.

[0005]

In each of the variable valve actuation mechanisms for changing the rotational speed of the camshaft during one revolution described above, the rotational force of the crankshaft is transmitted to the camshaft via the eccentrically rotating component. It At this time, the input shaft and the output shaft for the eccentrically rotating component are coaxial, but the input and output shafts and the rotating shaft of the eccentrically rotating component are not coaxial. Therefore, a connecting member is provided that allows eccentric rotation to transmit the rotational force.

The connecting member is composed of a guide groove side and a slider side that slides in the groove, and the driving torque of the cam shaft has positive and negative fluctuations. Therefore, the contact surface between the guide groove and the slider changes according to the torque fluctuation, and in addition, the slider is set to be slightly narrower than the guide groove width in order to reciprocally slide in the guide groove. A slight clearance is set between the sliding surfaces of these guide grooves and the slider.

Since the slider can slightly swing in the guide groove, an angle is generated between the wall surface (sliding surface) of the groove and the side surface (sliding surface) of the slider during torque transmission. , The following problems occur. That is, the edge portion of the slider bites into the guide groove, the edge portion of the slider scrapes the guide groove, and the groove width is enlarged. As a result, when the contact surface between the slider and the guide groove is changed when the rotational torque of the cam changes, the stroke is changed. Sound is generated. The edge portion of the slider scrapes the wall surface of the guide groove, and this shaving powder mixes with the engine oil to accelerate the wear of each sliding portion of the engine and shorten the life of the engine body. When the slider reciprocally slides in the guide groove, stick-slip occurs, causing cam rotation fluctuation, and the cam profile as designed cannot be obtained, impairing engine performance.

The present invention has been made in view of the above points, and in a variable valve mechanism that changes the rotational speed of a cam during one rotation, the connecting means for transmitting the rotational force from the camshaft to the cam is smoothly operated. An object of the present invention is to provide a variable valve mechanism that is operated.

[0009]

To achieve the above object, according to the present invention, in claim 1, a first rotating member to which a rotational force is transmitted from a crankshaft and a first rotating member are provided. An intermediate rotating member that is connected via the connecting means and that rotates with the rotation of the first rotating member, and an intermediate rotating member that is connected to the intermediate rotating member through the second connecting means and that rotates with the intermediate rotating member. A second rotating member that rotates by rotating the second rotating member;
A valve member that is provided integrally with or separately from the rotating member and that sets an intake air inflow period into the combustion chamber of the internal combustion engine or an exhaust emission period from the combustion chamber in correspondence with the rotation phase of the second rotating member; A shift mechanism that shifts the rotation of the first rotating member within one rotation of the second rotating member by displacing the intermediate rotating member within a plane perpendicular to the axis, and at least the first or second connecting means. On one side, a guide groove extending in the radial direction is formed on the side of one member connected to each other, and on the side of the other member, a pair of flat surfaces having a fitting width slightly smaller than the guide groove and slidingly contacting the side wall of the guide groove. A slider member having a sliding contact surface is formed, the slider member is rotatably supported with respect to the other member, and an edge portion in the traveling direction of the slider member is chamfered or rounded. It was done.

According to a second aspect of the present invention, the dimension of the chamfering or the R processing is set to be larger than 1/2 of the gap between the guide groove and each slider member. When the first rotating member rotates along with the rotation of the crankshaft, the intermediate member rotates via the shaft support member, and the intermediate member rotates together with the second member.
The rotating member rotates. The second rotary member is given a rotational phase with the first rotary member via the shaft support member according to the operating state of the internal combustion engine. The second rotating member controls the opening and closing of the valve member according to the rotation phase. The second rotating member delays the valve opening timing and advances the valve closing timing when the internal combustion engine is at a low speed. This shortens the valve opening period of the valve member. The second rotating member advances the valve opening timing and delays the valve closing timing when the internal combustion engine is at a high speed. This prolongs the valve opening period of the valve member.

By chamfering or rounding the edge of the slider member in the direction of travel in the guide groove, the oil can be scraped and the negative pressure generated in the sliding portion on the side transmitting the rotational force is low. The positive pressure generated in the sliding portion on the opposite side is increased, and the force for swinging the slider in parallel with the guide groove is largely exerted, so that the slider itself maintains the alignment.
Further, it becomes possible to secure a sufficient amount of oil in the sliding portion between these two. As a result, abrasion of the sliding portion is prevented, stick-slip is eliminated, and hitting sound is eliminated.

Further, the chamfer formed on the edge of the slider in the traveling direction or the dimension of R is set to be larger than 1/2 of the clearance between the slider member and the guide groove, so that the sliding contact surface of the slider is 1/2. An oil film equivalent to the clearance is always obtained.

[0013]

Embodiments of the present invention will be described below with reference to embodiments. FIG. 1 shows an essential part of a variable valve mechanism of an internal combustion engine (hereinafter referred to as “engine”) according to the present invention.
FIG. 3 is an assembled perspective view of a variable valve mechanism that controls the opening of an intake valve of one cylinder (for example, a first cylinder) in a multi-cylinder engine including two intake valves and two exhaust valves per cylinder.

In FIG. 1, a hollow shaft-shaped cam lobe 3 is externally fitted to a predetermined position of a cam shaft (first rotating member) 2 of the variable valve mechanism 1 so as to be relatively rotatable. Two cam parts 3a, 3
b is formed integrally. Then, one cam portion 3a
A guide groove 3c (FIG. 2) is formed in the outer end surface (front end surface) in the radial direction. In addition, the cam shaft 2 has a guide groove 3c.
A hole 2a is pierced in the vicinity of diametrically.

An annular eccentric spacer 4 is fitted on one end of the camshaft 2 so as to be relatively rotatable. The rotation center of the shaft hole of the eccentric spacer 4 is eccentric from the rotation center of the cam shaft 2 by a predetermined amount. A control gear 5 is integrally provided on one end surface of the eccentric spacer 4. The control gear 5 is slightly larger in diameter than the cam portions 3a and 3b of the cam lobe 3. The harmonic ring (intermediate rotating member) 6 has an annular shape, is fitted onto the eccentric spacer 4 so as to be rotatable relative to the eccentric spacer 4, and is rotatable around the rotation center of the eccentric spacer 4. The harmonic ring 6 is formed with holes 6a and 6b on both sides on one diameter in the axial direction. One hole 6a has a larger diameter than the other hole 6b, and a part of the circumference is formed. Open in the shaft hole of the harmonic ring 6. The harmonic ring 6 has a smaller diameter than the control gear 5.

The camshaft-side slider 7 is shaped to fit in the hole 6a of the harmonic ring 6 so as to be relatively rotatable, one side is fitted in the hole 6a, and the other side is the hole 2 of the camshaft 2.
The harmonic ring 6 is slidably supported by the tip of a shaft 8 whose base end is fitted and fixed to a in the radial direction of the harmonic ring 6. The cam lobe side slider 9 has the harmonic ring 6 via the shaft 9a.
Is rotatably fitted into and supported by the hole 6b, and is fitted in the guide groove 3c of the cam portion 3a so as to be slidable in the radial direction (FIG. 2). In this way, the cam shaft 2 and the cam lobe 3 are relatively rotatably connected via the shaft 8, the cam shaft side slider 7, the harmonic ring 6, the eccentric spacer 4, the cam lobe side slider 9, and the guide groove 3c.

The control shaft 10 has substantially the same length as the cam shaft 2, is arranged directly above the cam shaft 2 in parallel with the cam shaft 2, and is provided with a small gear 11 which meshes with the control gear 5. There is. A drive shaft of an actuator 12 having a built-in angle sensor is connected to one end of the control shaft 10. As the actuator 12, for example, an electric motor is used. The actuator 12 is fixed to the cylinder head of the engine.

The electronic control unit 13 has an engine speed Ne input from an engine speed sensor and a throttle opening θ input from a throttle position sensor (TPS).
Operating information such as th is input, and the actuator 12 is driven according to the operating state of the engine. The actuator 1
2 is not limited to an electric motor, but may be a hydraulic motor.

The cam portions 3a and 3b of the cam lobe 3 are brought into pressure contact with the rollers of the rocker arms 14 and 15, respectively, and the intake valve 1
6 and 17 are opened and closed. The intake valves 16 and 17 are, for example, poppet valves. In this way, the variable valve mechanism 1 that opens and closes the intake valve of one cylinder of the multi-cylinder engine is configured. A valve mechanism that opens and closes the exhaust valve of the cylinder is similarly configured.

Therefore, in the case of a 4-cylinder engine, the valve operating mechanism shown in FIG. 1 is provided for each cylinder for four cylinders along the longitudinal direction. Of course, the valve operating mechanism that drives the exhaust valve is similarly configured. The cam shaft 2 is connected to a pulley (not shown) fixed to the crank shaft of the engine via a pulley 18 fixed to the other end and a belt 19 and is rotationally driven in synchronization with the crank shaft. .

The cam lobe side slider 9 is shown in FIGS.
As shown in Fig. 1, a shaft 9a (Fig. 1) has a hole 9b formed at one end thereof so that one end of the shaft 9a can be rotatably fitted, and the upper and lower surfaces 9c, 9c facing the sliding direction form a curved surface (convex surface) of large radius. , Both wall surfaces (sliding contact surfaces) 3d, 3d of the guide groove 3c of the cam lobe 3.
Sliding contact surfaces (side surfaces) 9d, 9d facing each other are planes parallel to each other. The width of the slider 9 (sliding contact surface 9
d, the outer method of 9d) Da is the groove width (wall surface 3) of the guide groove 3c.
The inner diameter of d and 3d) is set smaller than Db by a predetermined clearance. The thickness of the slider 9 is set to be slightly smaller than the depth of the guide groove 3c.

As shown in FIGS. 3 and 7, the slider 9 has a chamfered edge 9e facing the sliding direction. The dimension of this chamfer is set to be larger than the difference between the width Db of the guide groove 3c and the width Da of the slider 9, that is, 1/2 of the clearance between them. By such chamfering, as will be described later, when the slider 9 slides in the guide groove 3c, the sliding contact surfaces 9d on both sides, wall surfaces 3d, 3 facing each other.
An oil film equivalent to ½ clearance is obtained between this and d.

The edge 9e of the slider 9 is not limited to chamfering, but may be processed into a curved surface having a radius R as shown in FIG. The radius R of the curved surface is set to be larger than the 1/2 clearance, like the chamfer dimension. As a result, as in the case of chamfering, the slider 9 is moved to the guide groove 3
When sliding in c, an oil film equivalent to 1/2 clearance is obtained between the sliding contact surfaces 9d, 9d on both sides and the opposing wall surfaces 3d, 3d.

Returning to FIG. 1, the cam shaft 2 is horizontally arranged on the cylinder head (not shown) of the engine along the longitudinal direction, and both ends thereof are rotatably supported by bearings provided on the cylinder head. Is pivotally supported. In the middle portion of the cam shaft 2, each cam lobe 3 is rotatably supported by each bearing portion provided on the cylinder head. That is, each of the bearing portions is composed of the two intake valves 1 of each cylinder of the cylinder head.
It is provided between 6 and 17, and rotatably supports the cylindrical portion 3d of the cam lobe 3. Then, the control shaft 11 is arranged directly above the cam shaft 2 in parallel with the cam shaft 2.

The reason why the cam lobe 3 is pivotally supported is that a guide groove 3c for connecting the cam shaft 2 and the cam lobe 3 so as to be relatively rotatable, an eccentric spacer 4, and a control gear 5 on one side of the cam portion 3a of the cam lobe 3. , Harmonic ring 6,
Since the cam shaft side slider 7, the cam lobe side slider 9 and the like are arranged, it is difficult in terms of space to provide a bearing for supporting the cam shaft 2. This is because it is preferable to pivotally support the cam lobe 3 to which a load is applied when the valve is opened. However, the cam lobe 3 does not necessarily have to be supported, and the intermediate portion of the cam shaft 2 may be supported.

The operation of the variable valve mechanism 1 will be described below.
As shown by arrows A to D in FIG. 1, the rotation of the cam shaft 2 is transmitted from the shaft 8 to the cam shaft side slider 7, the harmonic ring 6, the cam lobe side slider 9, the guide groove 3c of the cam lobe 3, and the cam lobe 3. , The cam lobe 3 rotates. With rotation of the cam lobe 3, the cam portions 3a, 3b
Opens and closes intake valves 16 and 17 via rocker arms 14 and 15. When the engine is in a steady operation state, the eccentric spacer 4 is fixed without rotating and serves to separate the rotation center of the cam shaft 2 and the cam lobe 3 from the rotation center of the harmonic ring 6. As a result, the camshaft 2
During the rotation, the first-order sinusoidal acceleration / deceleration can be alternately transmitted to the cam lobe 3.

The phase of the eccentricity of the eccentric spacer 4 with respect to the center of the cam shaft 2 is changed by the actuator 12 via the control shaft 10, the gear 11 and the control gear 5 to control the phase of the primary sinusoidal acceleration / deceleration of the cam lobe 3. To do. That is, when the eccentric spacer 4 is eccentric to the opposite side (upper side) of the rocker arm 14, the cam shaft 2 moves 90 degrees.
While rotating, the harmonic ring 6 is delayed by a first predetermined angle (for example, β) and the cam lobe 3 is rotated by a second predetermined angle (for example, β) larger than the first predetermined angle (β).
α (> β)) Delay.

When the engine is operating at a low speed, the electronic control unit 13 drives the actuator 12 so that the center of rotation of the eccentric spacer 4 is eccentric to the upper side in the direction opposite to the rocker arm 14 with respect to the center of rotation of the camshaft 2. Let As a result, the cam lobe 3 lags behind the rotation of the cam shaft 2 by the second predetermined angle angle (α) near the opening position of the intake valve 16, and conversely near the valve closing position, the second predetermined angle (α). ) Just proceed. As a result, the valve opening period can be shortened.

When the engine is operating at high speed, the electronic control unit 13 drives the actuator 12 so that the center of rotation of the eccentric spacer 4 is in the same direction (lower side) as the rocker arm 14 with respect to the center of rotation of the camshaft 2. Eccentric. As a result, the cam lobe 3 advances by a second predetermined angle (α) with respect to the rotation of the cam shaft 2 near the valve opening position of the intake valve 16, and conversely, near the valve close position, the second predetermined angle (α).
Just delayed. As a result, the valve opening period can be extended and the engine output can be increased.

In this way, the eccentric spacer 4 is rotated by the control shaft 10 and the harmonic ring 6 is rotated.
Is displaced in a plane perpendicular to the axis to change the rotation of the cam shaft 2 within one rotation of the cam lobe 3 to control the opening period of the intake valves 16 and 17. Next, the behavior of the slider 9 when the slider 9 reciprocates in the guide groove 3c of the cam lobe 3 will be described with reference to FIGS. 6 and 7.

When the slider 9 is not chamfered at the edge 9e as in the conventional case, when sliding in the guide groove 3c of the cam lobe 3 in the direction of arrow E, the slide guide 9 slides forward in the sliding direction. The edge portion of (3) scrapes off all the oil adhering to the wall surfaces (sliding contact surfaces) 3d, 3d of the guide groove 3c. In particular, as shown in FIG. 6, the cam drive torque F causes the slider 9 to move in one direction (1 / the clearance).
When the chamfering is not performed when the diagonal edge portion 9e inclining to about 2) comes into contact with the wall surfaces 3d and 3d of the guide groove 3c and is not chamfered, the oil taken in to the lower side in the figure in the sliding direction is shown. Less is. Therefore, the sliding surface 9 on the side for transmitting the cam driving force
The oil pressure (negative pressure) f1 generated at the sliding portion (lower side in the figure) between d and the wall surface 3d is high as shown by the curve I, and the oil pressure generated at the sliding portion on the opposite side (upper side in the figure). (Positive pressure) f2
Is low as shown by curve II. Further, in order to scrape off all the oil, the oil scraping pressure f3 acting near the lower end of the front end surface 9c of the slider 9 in the figure becomes higher than the oil scraping pressure f4 acting near the upper end. For this reason,
A swinging force f that directs the slider 9 parallel to the guide groove 3c.
5 does not work very much. That is, the slider 9 itself has no function of maintaining the alignment. Further, the oil required for lubrication between the sliding contact surfaces of the slide 9 and the guide groove 3c becomes insufficient, which causes abnormal wear of the sliding portion.

However, when the edge portion 9e of the slider 9 is chamfered, the wall surfaces 3d and 3d of the guide groove 3c are formed.
Only the excess oil adhering to d is scraped off, and the chamfered edge portion 9e on the lower side in the drawing on the front side in the sliding direction takes in oil (FIG. 7) to form an oil film necessary for lubrication. Then, the slider 9 slides on the oil coating. Then, by considering the inclination of the slider 9 and making the chamfer dimension larger than 1/2 of the clearance between the groove width of the guide groove 3c and the width of the slider 9, the sliding contact surfaces 9d, 9d of the slider 9 are formed. An oil film equivalent to 1/2 clearance is always obtained.

The slider 9 scrapes oil by a chamfered edge portion 9e on the lower side in the drawing on the front side in the sliding direction during sliding, and is generated at the sliding portion (the lower side in the figure) on the side for transmitting the rotational force. The oil pressure (negative pressure) f1 becomes low as shown by the curve III in FIG. 6, and the oil pressure (positive pressure) f2 generated at the sliding portion on the opposite side (upper side in the figure) is as shown by the curve IV in FIG. Become higher. Further, since the slider 9 only scrapes off excess oil, the oil scraping pressure f3 acting near the lower end of the front end surface 9c of the slider 9 in the figure is smaller than the oil scraping pressure f4 acting near the upper end. Also becomes lower (Fig. 7). As a result, the swinging force f5 that makes the slider 9 parallel to the guide groove 3c acts largely. That is, the slider 9 itself maintains the alignment. As a result, the slider 9 can reciprocate well in the guide groove 3c. The same applies to the case where the slider 9 slides in the arrow E'direction opposite to the above. In addition, the edge 9e of the slider 9 has a R
The case where the processing is performed is the same as the case where the chamfering processing is performed.

The present invention, like the slider member (slider 7, 9) of this embodiment, has a harmonic ring 6
However, the pin 36 is not limited to the one that is rotatably supported by (another member) via the shaft 9a, and the pin 36 is directly attached to the annular disk as in JP-A-5-202718 and JP-A-6-323114. It may be rotatably supported by 35 (another member). As for the variable valve mechanism, if it has a structure corresponding to the slider member of the present invention, the eccentric spacer 4 fitted to the outer periphery of the cam shaft 2 as in the present invention.
The invention is not limited to the variable valve mechanism in which the harmonic ring 6 is rotatably provided in the above.
No. 54, a variable valve mechanism in which a rotating body corresponding to the eccentric spacer 4 of the present invention is provided on the outer circumference of the harmonic ring 6, or the above-mentioned JP-A-5-202718 and JP-A-6-202718.
No. 323114, the present invention can also be applied to a variable valve mechanism that displaces an annular disc 35 corresponding to the harmonic ring 6 of the present invention by a disc housing 34 in a plane perpendicular to the axis. It goes without saying that the present invention can be variously modified without departing from the scope of the present invention.

[0035]

As described above, according to the present invention, the edge of the slider member in the direction of travel in the guide groove is chamfered or rounded.
By processing, the oil can be scraped, the negative pressure generated at the sliding part on the side transmitting the rotational force is low, and the positive pressure generated at the sliding part on the opposite side is high, and the slider is The force that swings parallel to the guide groove acts greatly,
Alignment is maintained by the slider itself. Further, it becomes possible to secure a sufficient amount of oil in the sliding parts of these both. As a result, abrasion of the sliding portion is prevented, stick-slip is eliminated, hitting is eliminated, and engine performance is prevented from being impaired. Moreover, the reliability of the engine including the movable valve mechanism is improved.

According to a second aspect of the present invention, the chamfer formed on the edge portion of the slider in the traveling direction or the dimension of R is larger than 1/2 of the clearance between the slider member and the guide groove, whereby the sliding contact surface of the slider. In addition, an oil film equivalent to 1/2 clearance is always obtained and wear of the sliding portion is prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main assembly of a variable valve mechanism according to the present invention.

FIG. 2 is an end view showing a fitted state of a cam lobe and a cam lobe side slider of FIG.

FIG. 3 is an enlarged view of a cam lobe side slider of FIG.

4 is a cross-sectional view of the slider of FIG. 3 taken along the line IV-IV.

5 is a front view showing another example of the slider of FIG. 2. FIG.

FIG. 6 is an explanatory diagram showing the behavior of the slider sliding in the guide groove of the cam lobe shown in FIG. 2;

FIG. 7 is an enlarged view of a main part of FIG. 6;

FIG. 8 is a sectional view of a main part of a conventional variable valve mechanism.

9 is a sectional view taken along the line IX-IX in FIG.

10 is a cross-sectional view taken along the line XX of FIG.

[Explanation of symbols]

 1 Variable valve mechanism 2 Cam shaft 3 Cam lobe 3a, 3b Cam part 3c Guide groove 3d Wall surface (sliding contact surface) 3d Cylindrical part 4 Eccentric spacer 5 Control gear 6 Harmonic ring 7 Cam shaft side slider 9 Cam lobe side slider 9a Shaft 9d Sliding Contact surface 9e Edge 10 Control shaft 11 Gear 12 Actuator 13 Electronic control device 14, 15 Rocker arm 16, 17 Intake valve

Claims (2)

[Claims] 1. A first device for transmitting a rotational force from a crankshaft.
A rotating member, an intermediate rotating member that is connected to the first rotating member via a first connecting unit, and rotates with the rotation of the first rotating member; and an intermediate rotating member and a second connecting unit. A second rotating member that is coupled and that rotates with the rotation of the intermediate rotating member; and a second rotating member that is provided integrally with or separately from the second rotating member.
A valve member that sets an intake air inflow period into the combustion chamber of the internal combustion engine or an exhaust gas discharge period from the combustion chamber in accordance with the rotation phase of the rotating member, and the intermediate rotating member is displaced in a plane perpendicular to the axis line, A speed change mechanism for changing the rotation of the first rotating member within one rotation of the second rotating member, wherein at least one of the first or second connecting means is radially directed toward one member to be connected to each other. And a slider member having a fitting width slightly smaller than that of the guide groove and having a pair of planar sliding contact surfaces slidably contacting the side walls of the guide groove on the other member side. The variable valve mechanism, wherein the slider member is rotatably supported with respect to the other member, and an edge portion in the traveling direction of the slider member is chamfered or rounded. 2. The variable valve mechanism according to claim 1, wherein a dimension of the chamfering or R-working is set to be larger than 1/2 of a gap between the guide groove and each slider member. .