JPH10325311A - Intake and exhaust valve drive control device for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Objective] To improve manufacturing work efficiency and reduce costs by reducing the number of parts, reduce the diameter and size of the device, and increase the degree of freedom in the layout of the drive mechanism. The driving apparatus includes first and second flange portions provided opposite to a drive shaft and a cam shaft, and an annular disk provided between the two flange portions. The operating angle of the intake valve is changed by eccentrically moving the center Y of the annular disk with respect to the axis X of the drive shaft. The annular disk is rotatably supported on the drive shaft via a cam ring 44 provided between the drive shaft and the annular disk, and the transmission member 42 of the transmission means 41 and the first to third links 56 to The eccentric rotation position is controlled by the rotational force of the control shaft 46 transmitted to the link mechanism 45 provided with 58.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake / exhaust valve drive control device for variably controlling 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 Various conventional intake / exhaust valve drive control devices of this type have been provided, one of which is disclosed in Japanese Patent Application Laid-Open No. Hei 5-20217 filed by the present applicant.

[0003] The outline will be described with reference to Figs.
This intake / exhaust valve drive control device includes a drive shaft 1 to which torque is transmitted from a crankshaft of a multi-cylinder engine via a sprocket.
A camshaft 2 provided coaxially and relatively rotatably on the outer peripheral side of the drive shaft 1, and a control mechanism provided between opposed divided ends of each camshaft 2 divided for each cylinder. 3 is provided. Each of the camshafts 2 has two cams 6, 6 on the outer periphery thereof for opening two intake valves 4, 4 per cylinder against valve springs 5 via valve lifters 4a, 4a. It is integrally provided and is rotatably supported by a pair of cam bearings 8 and 9 on the cylinder head 7.

[0006] As shown in FIG. 7, the control mechanism 3 has a ring-shaped first member integrally provided at one end of each camshaft 2.
An annular second flange portion 1 fixed to the flange portion 10 at a predetermined outer peripheral position of the drive shaft 1 by a connecting pin 11 via a sleeve 12a and opposed to the first flange portion 10
2 and the drive shaft 1 interposed between the two flange portions 10 and 12.
A substantially annular disk housing 14 provided to be swingable in a substantially radial direction from an axis X of the disk housing 1;
An annular disk 16 rotatably held via a plain bearing 13 in a large-diameter support hole provided on the inner periphery of the inner ring 4.

The disk housing 14 is rotatably supported at one end in the diameter direction by a support shaft 15 extending along the engine front-rear direction at the upper end of the cylinder head 7 and at the other end. Are caused to swing by a drive mechanism. Further, the first and second flange portions 10,
In the outer peripheral portion of the disk 12, elongated engagement grooves 17 and 18 are formed at 180 degrees from each other along the radial direction. Pins 19a, 19 that engage with grooves 17, 18
b is projected.

For example, when the engine is running at high speed, the disk housing 14 does not swing, and the center of the annular disk 16 matches the axis X of the drive shaft 1, while at low engine speed, the drive mechanism 20 The disk housing 14 swings with the support shaft 15 as a fulcrum, and eccentrically moves the annular disk 16 with respect to the axis X of the drive shaft 1.

That is, for example, when the engine is running at a high speed, the center of the disk 16 coincides with the axis X of the drive shaft 1, and no rotational phase difference occurs between the drive shaft 1 and the camshaft 2. Accordingly, the camshaft 2 rotates synchronously with the drive shaft 1 via the control mechanism 3 with the rotation of the drive shaft 1, so that the operating angles of the valves by the cams 6 and 6 become large, the valve opening timing is advanced, and the valve closing is performed. Since the timing is delayed, the intake charging efficiency using the intake inertial force is improved.

On the other hand, in the low rotation range, the center of the disk 16 is controlled to be eccentric from the axis X of the drive shaft 1 via the disk housing 14 by the drive mechanism.
When the pins 9a and 19b slide radially along the inner peripheral surfaces of the engagement grooves 17 and 18, and the one pin 19a approaches the axis X of the drive shaft 1, the other pin 19b is It becomes a relationship away from X. Therefore, in this case, the disk 16
Means that the angular velocity with respect to the drive shaft 1 increases,
6, the angular velocity of the camshaft 2 also increases. Therefore, the camshaft 2 is in a state where the speed is doubled with respect to the drive shaft 1.

Therefore, when the rotational phase difference between the drive shaft 1 and the camshaft 2 changes and the angular velocity of the camshaft 2 is relatively large, the rotational phases with respect to the drive shaft 1
When the angular velocity of the camshaft 2 becomes relatively small, the rotational phase is delayed until the rotational speeds of the camshaft 2 and the camshaft 2 become uniform.

The same phase point exists in the middle of the minimum and maximum points of the rotational phase difference, and when the rotational phase changes, the valve operating angle becomes shorter when the rotational phase before the same phase point is delayed. Is delayed, and the valve closing timing advances on the advance side of the rotation phase after the same phase point, so that the entire valve is controlled to be small. Therefore, the valve overlap of the intake and exhaust valves is reduced, the residual gas in the combustion chamber is reduced, and the fuel consumption can be improved by stable combustion.

[0011]

However, in the above-mentioned conventional apparatus, the disk housing 14 is supported at one end by the support shaft 15 provided at the upper end of the cylinder head 7 as described above. Swinging with the swinging fulcrum. Therefore, since the support shaft 15 must be provided, the number of parts and the size thereof are inevitably increased.

In addition, since the support shaft 15 is supported by the separate support mechanism on the cylinder head 7 independently of the cam bearings 8 and 9 of the camshaft 2 at all, the size is further promoted. And the cylinder head 7 of the device
A large mounting space on the top is required, and the mountability on the engine deteriorates.

Further, since one end of the disk housing 14 is supported by the support shaft 15, it is difficult to accurately determine the center of the annular disk 16 with respect to the axis X of the drive shaft 1. As a result, not only can desired valve timing control not be obtained, but also valve timing varies for each cylinder, and there is a possibility that the operation of the engine may become unstable due to the variation in output between the cylinders.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances.
A drive shaft that is rotationally driven by an engine, a camshaft that is divided for each cylinder, is provided on the outer periphery of the drive shaft so as to be relatively rotatable, and integrally has a cam that opens and closes an intake and exhaust valve on the outer periphery. A first flange portion fixed to one end of the camshaft; and a first flange portion fixed to a predetermined portion of the drive shaft.
A second flange portion facing the flange portion, an annular disk disposed between the two flange portions, the center of which is eccentrically movable with respect to the axis of the drive shaft, and a portion between the annular disk and each of the flange portions. And a drive mechanism for controlling an eccentric rotation position of the annular disk via a transmission means, the pin being slidable in a substantially radial direction of the annular disk, Between the outer peripheral surface of the drive shaft and the inner peripheral surface of the insertion hole of the annular disc through which the drive shaft is inserted,
A cam ring for rotatably supporting the annular disk on the drive shaft so as to be eccentrically rotatable is provided, and the transmission means includes a transmission member having one end coupled to an end of the cam ring;
It is characterized by comprising a link mechanism interposed between the transmission member and the drive mechanism.

According to a second aspect of the present invention, the link mechanism includes a first link having one end connected and fixed to the transmission member, and a first link having one end rotatably connected to the other end of the first link. Two links and a third link having one end rotatably connected to the other end of the second link and the other end connected and fixed to a control shaft of the drive mechanism.

According to a third aspect of the present invention, the transmitting member is
It is characterized in that it is formed in a cylindrical shape rotatably arranged on the outer periphery of the drive shaft, and lubricating oil is supplied between the transmission member and the drive shaft.

[0017]

1 to 3 show an embodiment in which an intake / exhaust valve drive control device according to the present invention is applied to an intake side of a multi-cylinder internal combustion engine. In the drawings, reference numeral 21 denotes a sprocket from an engine crankshaft. A plurality of camshafts, which are arranged to be rotatable relative to the outer periphery of the drive shaft 21 and are provided coaxially with the center X of the drive shaft 21, The drive shaft 21 extends in the front-rear direction of the engine and has an oil supply passage 21a for introducing lubricating oil from the outside in the direction of the internal axis.

The camshaft 22 is divided at a predetermined position in the longitudinal direction from a direction perpendicular to the axis for each cylinder, and the drive shaft 21 is inserted into an insertion hole 22a formed in the inner axial direction. It is rotatably supported by a cam bearing 24 provided at the upper end of the cylinder head 7. As shown in FIG. 2, two cams 26 for opening two intake valves 23 per cylinder via a valve lifter 25 are integrally provided on the outer peripheral surface of the camshaft 22.

As shown in FIGS. 1 and 2, the cam bearing 24 is provided on a main bracket 27 laid over a cam receiving surface formed on the upper surface of the cylinder head 7 and provided on the upper surface of the main bracket 27. And a pair of left and right cam bolts 29 and 30 for fastening both ends of both brackets 27 and 28 together. An arc-shaped bearing surface 27 is provided at the center of the upper surface of the main bracket 27.
While a is formed, an arc-shaped bearing surface 28a is formed at the center of the lower surface of the sub-bracket 28 and cooperates with the bearing surface 27a to bear a control shaft 46 described later.

A first flange portion 31 is integrally provided at one divided end of each camshaft 22. A U-shaped first flange portion is provided on the outer peripheral portion of the first flange portion 31.
The engagement groove 32 is formed along the radial direction. further,
A second flange 33 connected to the drive shaft 21 is provided at a position facing the first flange 31 with a predetermined gap. The outer diameter of the second flange portion 33 is set to be substantially the same as the outer diameter of the first flange portion 31, and a sleeve 33 a fitted on a predetermined outer peripheral surface of the drive shaft 21 is integrally formed on the inner peripheral portion. Then, the sleeve 33a is connected to the drive shaft 21 by a connecting pin 34 inserted through the sleeve 33a in the radial direction.

A U-shaped second engagement groove 35 is formed along the radial direction at the outer peripheral portion of the second flange portion 33, that is, at a position diagonally opposite to the first engagement groove 32 of the first flange portion 31. ing. The first engagement groove 32 and the second engagement groove 35 are provided with holding holes 39, 4 of an annular disk 38 described later.
The tips of the first and second pins 36 and 37 held at 0 are slidably engaged. Further, the two flange portions 3
An annular disk 38 is interposed between the first and third disks 33 in a sandwich shape.

The annular disk 38 has a substantially donut plate shape, has a relatively large insertion hole 38a in the center of which the drive shaft 21 is inserted, and the first engagement groove 3
As shown in FIG. 2, holding holes 39 and 40 for rotatably holding the base ends of the first and second pins 36 and 37 are provided at both end surface positions corresponding to the second engagement groove 35 and the second engagement groove 35, respectively. Each is formed to penetrate in the axial direction. The annular disk 38 is provided between the inner peripheral surface of the insertion hole 38a of the annular disk 38 and the drive shaft 21.
The cam ring 44 is eccentrically rotated by a cam ring 44 provided between the cam ring 44 and the eccentric rotation position of the eccentric rotation is controlled by a drive mechanism 43 via a transmission means 41.

As shown in FIG. 1, the thickness of the cam ring 44 changes in the circumferential direction, and the lowermost portion is formed as a maximum thickness portion 44a as shown in FIG. The annular disk 38 is rotatably supported by the drive shaft 21 via the cam ring 44.

The transmission means 41 includes a transmission member 42 rotatably interposed between the outer peripheral surface of the drive shaft 21 and the inner peripheral surface of the camshaft 22 as shown in FIGS. A link mechanism 45 is provided between the other end 42b of the member 42 and a control shaft 46 described later.

The transmission member 42 has two end portions 42a, 42
b is formed in a thin cylindrical shape, a relatively thick one end portion 42a is integrally connected to the cam ring 44 in the axial direction, and the entire length of each cam shaft 2
The second end 42 b is formed to be slightly longer than the combined length of the second flange 1 and the first flange 31, and the other end 42 b protrudes from the end of the camshaft 22.

As shown in FIGS. 1, 4 and 5, one end 56a of the link mechanism 45 is connected to the other end 4 of the transmission member 42.
2b, a rod-shaped second link 57 having one end 57a rotatably connected to the other end 56b of the first link 56, and a second end 57a connected to the second end 56b. The other end 57b of the link 57 is rotatably connected to the other end 57b,
The other end 58b is constituted by a raindrop-shaped third link 58 integrally fixed to the control shaft 46.

The first link 56 is disposed obliquely downward at a predetermined angle when the engine is running at a low speed, and has a large diameter one end 56a.
Is fixedly inserted through the insertion hole 56c into the other end 42b of the transmission member 42, and the first support pin 59 is fixed into a pin insertion hole formed in the small-diameter other end 56b. The second link 57 is provided along the up and down direction, one end 57a is rotatably connected via an insertion hole 57c into which the first support pin 59 is inserted, and the other end 57b is connected to the second link 57. It is rotatably connected to a second support pin 60 fixed to a small end 58a of the three link 58 via an insertion hole 57d. Further, the third link 58 is disposed in substantially the same direction as the first link 56, and the other end 58b is integrally fixed to the control shaft 46.

As shown in FIG. 2, the driving mechanism 43 includes the control shaft 46 provided in parallel above the camshaft 22 and a stepping motor 47 as an electromagnetic actuator provided at one end of the control shaft 46. It is composed of

The control shaft 46 has a relatively small outer diameter, extends in the front-rear direction of the engine,
A large diameter portion 46a corresponding to the cam bearings 24, 24 is supported between the bearing surfaces 27a, 28a.

The stepping motor 47 is driven to rotate by a controller 49.
Is configured to detect the engine speed and the load of the engine by various sensors such as a crank angle sensor and an air flow meter and output a control signal to the stepping motor 47.

As shown in FIG. 2, the drive shaft 21 has an oil supply passage 21a formed on a peripheral wall where the cam ring 44 is located and a peripheral wall which is located substantially at the center of the transmission member 42 in the longitudinal direction.
An oil hole 50 and an oil passage hole 51 communicating with the oil passage are formed to penetrate along the radial direction. On the other hand, the thick portion 4 of the cam ring 44
4a, an oil hole 52 is formed at a position corresponding to the oil hole 50 so as to penetrate in the radial direction. The oil passage hole 5
An oil passage 53 smaller in diameter than the oil passage hole 51 is also formed radially through the peripheral wall of the transmission member 42 facing 1.

Further, the drive shaft 2 on which the transmission member 42 is located
As shown in FIG. 2, the oil passages 51 and 5 are provided on the outer peripheral surface of the transmission member 42 where the camshaft 22 is located.
The first and second oil grooves 54 and 55 communicating with 3 are formed along the axial direction.

More specifically, the first oil groove 54 on the outer peripheral surface of the drive shaft 21 is formed in a substantially cylindrical shape, and its axial length is set shorter than both end portions 42a and 42b of the transmission member 42. Have been. Therefore, the transmission member 42 is arranged such that only the inner peripheral surfaces of both ends 42 a and 42 b are slidably contacted with the outer peripheral surface of the drive shaft 21 due to the presence of the first oil groove 54.

On the other hand, the second oil groove 55 on the outer peripheral surface of the transmission member 42
Is formed in a substantially cylindrical shape, and its axial length is set inside the both ends 42a and 42b. Therefore, both ends 42a and 42b are formed by the presence of the second oil groove 55.
Are disposed so as to be slidable on the inner peripheral surface of the camshaft 22.

The operation of this embodiment will be described below.
First, when the engine is running at a low speed, the stepping motor 47 rotates in one direction in response to a control signal from the controller 49 which detects such an operating state, and rotates the control shaft 46 in the same direction by a predetermined angle θ1 (see FIG. 5). Therefore, the third
The link 58 rotates to the solid line position in FIGS. 1 and 5, and accordingly, the second link 57 descends to the illustrated position to rotate the first link 56 to the illustrated position. Accordingly, the transmission member 42 rotates to the predetermined angle θ2, and the cam ring 44 rotates in one direction to an angle of θ2 (about 90 °).
As shown in FIGS. 1 and 5, the thick portion 44a is rotated and held at a position where the thickest portion 44a is located at the lowermost end.

Therefore, the center Y of the annular disk 38 moves eccentrically from the axis X of the drive shaft 21 to a vertically downward position. Therefore, the first engagement groove 3 of the first flange portion 31
2 and the first pin 36 and the second engagement groove 35 and the second pin 37
Is reciprocated in the radial direction for each rotation of the drive shaft 21, and the angular velocity of the annular disk 38 changes.

That is, the first pin 36 slides in the first engagement groove 32 to approach the center X of the drive shaft 21, and the second pin 37 slides in the second engagement groove 35 to move to the center. When moving away from X, the annular disk 38 has an increased angular velocity with respect to the drive shaft 21, and the angular velocity of the camshaft 22 has also increased.
The angular velocity ratios (wc / wd) of 1 and 22 have the characteristics shown by the broken line in FIG. 6A (the above operation is indicated by the * mark in FIG. 6A). Therefore, the camshaft 22 is in a state where the speed is doubled with respect to the drive shaft 21.

As a result, the camshaft 22 and the cam 26
The rotational phase difference between the motor and the drive shaft 21 changes as shown by the broken line in FIG. 6B. Therefore, the valve lift characteristic of the intake valve 23 has a smaller valve operating angle (valve opening period) as shown by the broken line in FIG. 6C, the valve opening timing is late, and the valve closing timing is sufficiently early. For this reason, the valve overlap with the exhaust valve is reduced, the combustion is improved, and the fuel efficiency can be improved.

On the other hand, when the engine shifts from the low engine speed range to the high engine speed range, a control signal is output from the controller 49 which has detected the operating state to the stepping motor 47, and the control shaft 46 is turned at a predetermined angle in the opposite direction to the above. It rotates at θ1 (see FIG. 5). Therefore, each link 56, 57, 5
8 rotates counterclockwise in the reverse direction as indicated by the broken lines in FIGS. 4 and 5 to rotate the transmission member 42 by a predetermined angle θ2. As a result, the cam ring 44 is rotated and held at the left end position in the figure at the thick portion 44a. For this reason, the annular disc 3
8, the center Y moves eccentrically from the axis X of the drive shaft 21 to an upper left position in the figure as shown. Therefore, the second
The engagement groove 35 and the second pin 37 and the first engagement groove 32 and the first
As described above, the sliding position with the pin 36 reciprocates in the radial direction of the annular disk every time the drive shaft 21 rotates, and the angular velocity of the annular disk 38 changes.

Then, the angular velocity of the camshaft 22 with respect to the drive shaft 21 decreases with the change in the angular velocity of the annular disk 38, contrary to that at the time of low rotation, and the angular velocity ratio between the two 21 and 22 is the characteristic shown by the solid line in FIG. Become. Therefore, the camshaft 22 is in a constant speed state with respect to the drive shaft 21,
The rotation phase of the camshaft 22 with respect to the drive shaft 21 changes as shown by the solid line in FIG. 6B, and has a change characteristic in which the phase of the camshaft 22 is delayed. For this reason, the intake valve 23
As shown by the solid line in FIG. 6C, the valve operating angle (valve opening period) increases while the valve lift characteristic remains constant, as shown by the solid line in FIG. 6C. . For this reason, the intake charging efficiency using the inertial intake is improved, and the output torque can be improved.

In this embodiment, the annular disk 38
Is rotatably supported by the inner drive shaft 21 via the cam ring 44, so that a conventional support shaft and a support mechanism for supporting the support shaft are not required.
The number of parts can be reduced, and the entire apparatus can be made compact.

Further, since the conventional disk housing has been eliminated, the flange portions 31 and 33 and the annular disk 3 have been omitted.
It is possible to make the outer diameter of the control mechanism composed of 8 or the like sufficiently small. As a result, the reduction in diameter and the weight and size are further promoted, and the height of the cylinder head 7 can be reduced. Further, the assemblability of the device to the cylinder head 7 is improved.

Further, since the annular disk 38 is supported by the drive shaft 21 as described above, the amount of eccentricity of the annular disk 38 with respect to the drive shaft 21 can be accurately determined, and as a result, the control accuracy of the valve timing can be improved. Is improved.

In addition, the transmission member 42 and the control shaft 46
Are connected by the link mechanism 45, so that the degree of freedom of the layout of the control shaft 46 is improved. That is,
Since the angles of the links 56 to 58 can be set arbitrarily, the arrangement of the control shaft 46 can be set arbitrarily. Therefore, the mountability of the device on the engine is further improved.

Further, the transmission member 4 is provided by the link mechanism 45.
Since the play between the control shaft 2 and the control shaft 46 is reduced, the play of the rotation of the transmission member 42 due to the fluctuation of the rotational torque of the camshaft 22 is suppressed, and the generation of a tapping sound is prevented.

Further, since the inner peripheral side of the annular disk 38 is supported, the entire sliding area with the cam ring 44 and the like is reduced, and the sliding resistance of the annular disk 38 can be reduced.

Further, with the rotation of the drive shaft 21, the load acting on the annular disk 38 via both the pins 36 and 37 is received by the drive shaft 21 via the cam ring 44, so that the annular disk 38 is held. Rigidity increases. Therefore, the center of the annular disk is not displaced by a large load generated when the cam pushes down the valve lifter as in the related art. As a result, it is possible to prevent the occurrence of the deviation of the valve lift and the irregular movement of the intake valve.

The oil supply passage 21a is connected to the oil holes 50,5
2, the drive shaft 21, the cam ring 44, and the cam ring 4
Since lubricating oil can be positively supplied between the inner ring 4 and the inner peripheral surface of the insertion hole 38a, the lubricating performance of the cam ring 44, the annular disk 38, and the like is improved. Further, oil passage holes 51,
Since the lubricating oil can be sufficiently supplied to the inner and outer circumferences of the transmission member 42 via the oil passages 53 and the oil grooves 54 and 55, the sliding portions such as the transmission member 42 and the cam ring 44 can always be smoothly rotated. .

Further, the transmission member 42 has not only the entire inner and outer peripheral surfaces with respect to the outer peripheral surface of the drive shaft 21 and the inner peripheral surface of the cam shaft 22, but also both end portions 42a having a predetermined length in the axial direction.
Since only the inner and outer peripheral surfaces of 42b are slidably supported, the sliding area is reduced. Therefore, the sliding frictional resistance is reduced, and a smooth rotation action of the camshaft 22 and the transmission member 42 can be obtained at all times. In particular, both ends 42a, 4
The lubricating oil supplied to the first and second oil grooves 54, 55 provided partially, not entirely, on the inner and outer circumferences between 2b, further reduces the sliding frictional resistance of both ends 42a, 42b.
Therefore, the smooth rotation of the camshaft 22 and the transmission member 42 is further promoted, and the rotation of the transmission member 42 due to the viscous resistance of the lubricating oil in the oil groove 54 can be prevented.

Further, the camshaft 22 is basically supported by the cam bearing 24. Since both ends of the camshaft 22 are supported by the drive shaft 21 via the transmission member 42, the camshaft 22 swings during rotation. And other unstable rotations can be sufficiently suppressed.

If the straightness of the drive shaft 21, the transmission member 42, and the camshaft 22 deteriorates due to a machining accuracy error, a bending load at the time of valve lift, etc., a strong load is locally applied, and rotation reluctance is reduced. If there is a risk of locking or the like and the straightness is poor, the drive shaft 2
1, the transmission member 42 and the camshaft 22 may not be assembled. However, in the present embodiment, as described above, the camshaft 22 and the transmission member 42
Since the both ends are supported by the existence of 4,55 (clearance), the above-mentioned problem is eliminated.
Also, it is only necessary to ensure the dimensional accuracy of each end of the camshaft 22 and the transmission member 42. Since high dimensional accuracy in the entire longitudinal direction is not required, the processing becomes easier, and the processing cost is reduced. Can be achieved.

Each oil groove 54, 55 (clearance)
Without the oil holes 51 and 53, lubrication between the drive shaft 21 and the transmission member 42 and between the transmission member 42 and the camshaft 22 is possible.

The present invention is not limited to the configuration of the above-described embodiment. For example, the transmission member 42 and the cam ring 4
And the cam ring 44 is formed separately from the transmission member 42.
Can be press-fitted and fixed to one end 42a.

[0054]

As is apparent from the above description, according to the present invention, the annular disk is not a conventional support shaft,
Since the drive shaft is rotatably supported by the drive shaft via the cam ring, the support shaft and the support mechanism for supporting the support shaft are not required at all, and the conventional disk housing can be eliminated. In addition, the efficiency of the manufacturing operation can be improved and the cost can be reduced, and the diameter and size of the entire apparatus can be reduced. As a result, the mountability to the engine can be improved and the cylinder head can be set low.

Further, since the annular disk is supported by the drive shaft via the cam ring as described above, the rigidity of the support is increased, and the center of the annular disk due to the load can be prevented from shifting. As a result, a decrease in control accuracy of the valve timing is prevented. Further, the positional accuracy of the center of rotation of the annular disk with respect to the axis of the drive shaft can be easily obtained.

Further, since the transmission member is interposed between the drive shaft and the camshaft in a housed state with the elimination of the disk housing, the outer diameter of the device can be further reduced.

Further, since the transmission member and the drive mechanism are connected by the link mechanism, the degree of freedom of the layout of the drive mechanism is improved, and the play of the linkage between the transmission member and the drive mechanism is reduced, and the rotation of the camshaft is reduced. Rotational play of the transmission member to which the torque fluctuation has been transmitted is suppressed, and generation of loud tapping and the like can be prevented.

Further, according to the third aspect of the invention, since the lubricating oil is positively supplied between the drive shaft and the transmission member, the lubricating performance of each sliding portion is improved, and the sliding friction is improved. Resistance can be greatly reduced, and wear can be prevented.

[Brief description of the drawings]

FIG. 1 is an essential part cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 3;

FIG. 3 is a plan view of a main part of the embodiment.

FIG. 4 is a sectional view taken along the line AA of FIG. 3 showing the operation of the present embodiment.

FIG. 5 is a sectional view taken along line BB of FIG. 3;

6A is a characteristic diagram of an angular velocity ratio between the drive shaft and the camshaft in the present embodiment, B is a characteristic diagram of a rotational phase difference between the drive shaft and the camshaft corresponding to A, and C is a valve lift characteristic diagram.

FIG. 7 is a sectional view of a main part showing a conventional device.

FIG. 8 is a view taken in the direction of arrow C in FIG. 7;

[Explanation of symbols]

 Reference Signs List 21 drive shaft 21a oil supply passage 22 camshaft 23 intake valve 31 first flange 33 second flange 36, 37 first and second pin 38 annular disk 41 transmission means 42 Transmission member 43 Drive mechanism 44 Cam ring 45 Link mechanism 46 Control shaft 54, 55 First and second oil grooves 56 First link 57 Second link 58 Third link

Continued on the front page (72) Inventor Yoshihiko Yamada 1370 Onna, Atsugi-shi, Kanagawa Prefecture Inside Unisia Gex Co., Ltd. (72) Inventor Shinichi Takemura 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.

Claims (3)

[Claims] 1. A cam, which is integrally provided with a drive shaft that is rotationally driven by an engine, and a cam that is divided for each cylinder and is rotatably provided on an outer periphery of the drive shaft and that opens and closes an intake and exhaust valve on the outer periphery. A shaft, a first flange fixed to one end of each of the camshafts, a second flange fixed to a predetermined portion of the drive shaft and facing the first flange, and between the two flanges. An annular disk which is disposed and whose center can be eccentrically moved with respect to the axis of the drive shaft, is interposed between the annular disk and each of the flange portions, and is slidable substantially in the radial direction of the annular disk. An intake / exhaust valve drive control device comprising a pin and a drive mechanism for controlling an eccentric rotation position of the annular disk via a transmission means, wherein an outer peripheral surface of the drive shaft and an annular disk through which the drive shaft is inserted are inserted. Between the inner peripheral surface of the hole A cam ring for rotatably supporting the disk in an eccentric manner on a drive shaft; and a transmission member having one end coupled to an end of the cam ring; and a transmission member having one end coupled to an end of the cam ring. And a link mechanism interposed between the intake and exhaust valves. 2. A link comprising: a first link having one end connected and fixed to the transmission member; a second link having one end rotatably connected to the other end of the first link; 2. The internal combustion engine according to claim 1, wherein the second link is rotatably connected to the other end of the second link, and the third link is connected and fixed at the other end to the control shaft of the drive mechanism. Intake and exhaust valve drive control device. 3. The transmission member according to claim 1, wherein the transmission member is formed in a cylindrical shape rotatably disposed on an outer periphery of a drive shaft, and lubricating oil is supplied between the transmission member and the drive shaft. 3. An intake and exhaust valve drive control device for an internal combustion engine according to claim 1.