JPH10205310A - Intake/exhaust valve during controller of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the facilitation of molding work and the reduction of cost while achieving the small diameter and miniaturization of a device as well as to achieve the improvement of manufacturing work efficiency and the reduction of cost by decreasing the number of parts. SOLUTION: An intake/exhaust valve driving controller is provided with first and second flange parts 31, 33 so arranged as to face a driving shaft 21 and a camshaft 22, and an annular disc 38 provided between both flange parts 31, 33, and the center of the annular disc is eccentrically moved in relation to the axis X of the driving shaft so as to change the operating angle of the intake/exhaust valve. The annular disc is rotatably supported on the driving shaft through a cam ring 44 provided between the driving shaft and the annular disc. The cam ring is pressed and fixed on one end 42a of a transmitting member 42 of a transmitting mechanism 41, a driven gear 45 to be meshed with a driving gear 48 is integrally provided at the other end 42b by forging, and the annular disc is essentially rotated and controlled by rotational force of a driving mechanism 43, transmitted to the cam ring through both gears.

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. 8, the control mechanism 3 has an annular first shaft 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.

Further, as described above, the rotational force of the drive shaft 1 is transmitted to the camshaft 2 via the pins 19a, 19b and the flanges 10, 12, so that the pins 19a, 19b Is transmitted to the disk housing 14 via the annular disk 16. As shown in FIG. 9, the disk housing 14 is supported by the support shaft 15 and the driving mechanism 20 at only two locations, that is, both ends 14a and 14b, which are outer peripheral bosses, and is formed in a relatively thin ring shape. Have been.

For this reason, when the cam 6 pushes down the valve lifter 4a (when the intake valve 4 is opened), a large load is generated, for example, as shown by an arrow in FIG.
When transmitted as a reaction to the upper left through the pin 6 and both pins 19a and 19b, the disk housing 14 is easily deformed upward as indicated by a two-dot chain line, whereby
The center Y of the annular disk 16 is also easily displaced slightly upward. Therefore, the torque of the drive shaft 1 is not accurately transmitted to the camshaft 2, and as a result, the desired valve timing may not be obtained.

[0016]

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. A sliding pin interposed between them to link the two,
A drive mechanism for controlling the eccentric rotation position of the annular disk via a transmission mechanism, the intake and exhaust valve drive control device comprising: an outer peripheral surface of the drive shaft and a through hole of the annular disk through which the drive shaft is inserted. A cam ring is rotatably provided between the cam shaft and the inner peripheral surface, and the annular disk is eccentrically supported on the drive shaft via the cam ring. A transmission member rotatably provided between the transmission ring and the inner peripheral surface of the transmission member, and the cam ring is press-fitted and fixed to one end of the transmission member.

According to a second aspect of the present invention, a drive shaft rotatably driven by an engine is provided for each cylinder and rotatably provided on the outer periphery of the drive shaft, and the intake and exhaust valves are opened on the outer periphery. A camshaft integrally having a cam, a first flange fixed to one end of each camshaft, a second flange fixed to a predetermined portion of the drive shaft and facing the first flange, An annular disk disposed between the two flange portions, the center of which is eccentric with respect to the axis of the drive shaft, and a slider interposed between the annular disk and each of the flange portions to link the two; An intake / exhaust valve drive control device comprising a driving pin and a drive mechanism for controlling the eccentric rotation position of the annular disk via a transmission mechanism, wherein the outer peripheral surface of the drive shaft and the annular disk through which the drive shaft is inserted The gap between the inner surface of the insertion hole A ring is rotatably provided, and the annular disk is eccentrically supported by a drive shaft via the cam ring so as to be eccentrically rotatable. On the other hand, the transmission mechanism is provided between an outer peripheral surface of the drive shaft and an inner peripheral surface of the cam shaft. A transmission member rotatably provided in the transmission mechanism, a drive gear linked to the drive mechanism, and a driven gear meshing with the drive gear, and connected to the cam ring at one end of the transmission member, and The driven gear is provided integrally with the other end.

According to a third aspect of the present invention, a drive shaft rotatably driven by an engine is provided for each cylinder and is rotatably provided on the outer periphery of the drive shaft, and the intake and exhaust valves are opened on the outer periphery. A camshaft integrally having a cam, a first flange fixed to one end of each camshaft, a second flange fixed to a predetermined portion of the drive shaft and facing the first flange, An annular disk disposed between the two flange portions, the center of which is eccentric with respect to the axis of the drive shaft, and a slider interposed between the annular disk and each of the flange portions to link the two; An intake / exhaust valve drive control device comprising a driving pin and a drive mechanism for controlling the eccentric rotation position of the annular disk via a transmission mechanism, wherein the outer peripheral surface of the drive shaft and the annular disk through which the drive shaft is inserted The gap between the inner surface of the insertion hole A ring is rotatably provided, and the annular disk is eccentrically supported by a drive shaft via the cam ring so as to be eccentrically rotatable. On the other hand, the transmission mechanism is provided between an outer peripheral surface of the drive shaft and an inner peripheral surface of the cam shaft. A transmission member rotatably provided on the transmission mechanism, a driving gear linked to the driving mechanism, and a driven gear meshing with the driving gear. The cam ring is connected to one end of the transmission member, and the driving gear And the driven gear are formed in a helical tooth shape.

[0019]

1 to 3 show a first 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 crankshaft of the engine. A drive shaft from which rotational force is transmitted from the
Are a plurality of camshafts arranged on the outer periphery of the drive shaft 21 so as to be relatively rotatable and provided coaxially with the center X of the drive shaft 21. The drive shaft 21 extends in the front-rear direction of the engine. In addition, an oil supply passage 21a for introducing lubricating oil from the outside in the direction of the internal axis is formed.

The camshaft 22 is divided for each cylinder at a predetermined position in the longitudinal direction from the direction perpendicular to the axis, 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 intake valves 23 per cylinder are provided at predetermined positions on the outer periphery.
The two cams 26 are provided integrally to open the valve via a valve lifter 25 against the spring force of a valve spring (not shown).

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. Is formed. The first engagement groove 32 and the second engagement groove 35 have a holding hole 3 for an annular disk 38 described later.
The distal ends of the first and second pins 36 and 37 held by the components 9 and 40 are slidably engaged. Further, an annular disk 38 is interposed between the flange portions 31 and 33 in a sandwich shape.

The annular disk 38 has a substantially donut shape, and has a relatively large insertion hole 38a formed in the center thereof through which the drive shaft 21 is inserted.
As shown in FIG. 1, 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 and second engagement grooves 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 cam ring 44.
Drive mechanism 43 via transmission mechanism 41 for transmitting rotational force to
Controls the eccentric rotation position.

As shown in FIG. 2, the thickness of the cam ring 44 changes in the circumferential direction, and the lowermost portion is formed as the thickest portion 44a as shown in FIG. The annular disk 38 is rotatably supported by the drive shaft 21 via the cam ring 44. Further, the cam ring 44 is formed with a press-fitting hole 44b for press-fitting into one end 42a of a transmission member 42 described later in the interior direction of the vehicle.

The transmission mechanism 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 spur gear-shaped driven gear 45 provided at the other end 42 b of the member 42, and a spur gear-shaped driving gear 4 provided on a control shaft 46 of the driving mechanism 43 and meshed with the driven gear 45.
And 8.

The transmission member 42 is formed in a thin cylindrical shape, the cam ring 44 is press-fitted and fixed to one end 42a, and the driven gear 45 is integrally provided on the outer peripheral surface of the other end 42b. I have. That is, the driven gear 45 is formed integrally with the transmission member 42 by forging. The driven gear 45 is rotatably interposed between the cam 26 at the end of the camshaft 22 and the sleeve 33 a of the second flange 33.

As shown in FIG. 1, the drive 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 large-diameter spur gear 48 is integrally provided between the two large-diameter portions 46a.

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 FIGS. 2 and 4, the drive shaft 21 has a peripheral wall on which the cam ring 44 is located and a peripheral wall located substantially at the center of the transmission member 42 in the longitudinal direction. The hole 50 and the oil passage hole 51 are formed so as to penetrate in the radial direction. On the other hand, an oil hole 52 is formed in the thick portion 44a of the cam ring 44 at a position corresponding to the oil hole 50 so as to penetrate in the radial direction. Further, an oil passage 53 having a smaller diameter than the oil passage hole 51 is formed in the peripheral wall of the transmission member 42 facing the oil passage hole 51 in a radial direction.

Further, the drive shaft 2 on which the transmission member 42 is located
Transmission member 4 on which the outer peripheral surface 1 and the camshaft 22 are located
1 and 4, each oil passage 5
First and second oil grooves 54 and 55 communicating with the first and third oil grooves 53 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,
The length in the axial direction is the two end portions 42a, 42 of the transmission member 42.
It is set shorter than b. Therefore, the transmission member 4
2 are both ends 42a, 42a due to the presence of the first oil groove 54.
Only each inner peripheral surface of b is slidably disposed on the outer peripheral surface of the drive shaft 21.

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 by the control signal from the controller 49 that detects such an operation state, and rotates the control shaft 46 in the same direction. Therefore, the two spur gears 48 and 45 rotate with each other to transmit the rotational force to the transmission member 42, whereby the cam ring 44 rotates in one direction, and as shown in FIGS. It is rotated and held at the lower end position.
For this reason, the center Y of the annular disc 38 is
Eccentrically moves from the axis X of X to the vertically downward position. Therefore, the first engagement groove 32 of the first flange portion 31 and the first pin 3
6 and the sliding position between the second engagement groove 35 and the second pin 37 reciprocate 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 speed ratios (wc / wd) of 1 and 22 have the characteristics indicated by the broken line in FIG. 5A (the above operation is indicated by the * mark in FIG. 5A). 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. 5B. Therefore, the valve lift characteristic of the intake valve 23 has a small valve operating angle (valve opening period) as indicated by the broken line in FIG. 5C, and 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 further moved by 180 ° in the same direction. Rotate. Therefore, the cam ring 44 is rotatably held at a position where the thick portion 44a is the uppermost end. Therefore, the center Y of the annular disk 38 moves eccentrically from the axis X of the drive shaft 21 to a vertically upward position as shown in the figure. Therefore,
The sliding positions of the second engagement groove 35 and the second pin 37 and the first engagement groove 32 and the first pin 36 are the same as those described above.
Reciprocates in the radial direction of the annular disk with each rotation of the circular disk, 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, as opposed to that at the time of low rotation, and the angular velocity ratio between the two 21 and 22 differs from the characteristic shown by the solid line in FIG. (The point marked with a star in FIG. 5A). Therefore, the camshaft 22 is connected to the drive shaft 2
As a result, the vehicle is decelerated twice with respect to 1.
The rotation phase of No. 2 changes as shown by the solid line in FIG. 5B, and has a substantially symmetrical change characteristic with the low rotation speed. For this reason, in the intake valve 23, the valve operating angle (valve opening period) increases while the valve lift characteristic remains constant as shown by the solid line in FIG. 5C, and the valve opening timing is earlier than at the time of low rotation. Become
The valve closing timing is delayed. 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.

In addition, since the conventional disk housing is also eliminated, the flange portions 31 and 33 and the annular disk 3 are not used.
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. As a result, the valve timing control accuracy can be improved. Is improved.

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. .

In addition, the transmission member 42 is not the entire inner and outer peripheral surface with respect to the outer peripheral surface of the drive shaft 21 and the inner peripheral surface of the camshaft 22, but has both ends 42a,
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
First and second oil grooves 5 partially provided on the inner and outer circumferences between 2b
4, 55, lubricating oil supplied to both ends 42a,
42b further reduces the sliding frictional resistance. 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, in the present embodiment, the cam ring 44 formed separately from the transmission member 42 is press-fitted and fixed to one end 42a of the transmission member 42, and the driven gear 45 is integrally provided by forging the other end 42b. , Making the manufacturing operation easier. That is, by the integrated structure of the driven gear 45 and the transmission member 44, high-precision coaxiality of the two members 44 and 45 is obtained, thereby greatly facilitating the forming operation such as forging or machining. In addition, since the cam ring 44 is formed separately from the transmission member 42, the cam ring 44 can be formed without considering the coaxiality of both members, so that these forming processes are facilitated. That is, when the cam ring 44 and the transmission member 42 are integral, the two members 42 and 44 are not coaxial, so that
A separate centering method for the outer periphery processing of the cam ring 44 is required, and the forming process becomes complicated. However, if the molding is performed separately, the separate centering method is not required, so that the forming process is facilitated. . As a result, it is possible to improve the processing efficiency and reduce the cost.

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

If the straightness of each of the drive shaft 21, the transmission member 42, and the camshaft 22 deteriorates due to an error in machining accuracy, 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.

If the outer diameter of the cam ring 44 is increased and the pitch diameter of the pins 36 and 37 of the annular disk 38 is increased, the load acting on the pins 36 and 37 can be reduced. , 37 and each engagement groove 32, 3
5, the influence on the rotational angle deviation of the camshaft 22 due to the clearance between them can be reduced. In other words, under the same clearance condition, the larger the pitch circle, the smaller the angular deviation of the camshaft 22. In addition, the collision noise between the pins 36 and 37 and the engagement grooves 32 and 35 due to the clearance can be suppressed to be small.

FIG. 6 shows a second embodiment of the present invention, in which a driven gear 45 provided at the other end 42b of the transmission member 42 is formed in a helical shape instead of a spur gear, and the driving gear 4
8 also has a helical shape. In this way, it is intended to suppress the impact sound between the teeth generated between the gears 45 and 48 due to the positive and negative rotational torque fluctuations generated in the camshaft 22.

That is, the time when the cam 26 of the camshaft 22 pushes down the valve lifter 25 and the time when the cam 26 is pushed up through the valve lifter 25 by the spring force of the valve spring after passing the peak cam lift (maximum lift of the cam). However, in the former case, the first pin 36
In this case, the camshaft 22 is driven to rotate via the first flange portion 31, whereas, in the latter case, the first pin 36 is driven by the camshaft 22. For this reason, the annular disc 38 is connected via the first pin 36.
A phenomenon occurs in which the radial load acting on the motor is almost reversed. Accordingly, a reversal load acts on the cam ring 44 that holds the annular disk 28 in rotation, and the torque acting on the driven gear 45 from the transmission member 42 changes as shown in FIG. Here, the solid line in FIG. 7 shows the torque change when the driven gear 45 and the drive gear 48 are spur gears as in the first embodiment, and the broken line shows the torque change when the helical gears in this embodiment are used. Therefore, when the torque changes from negative (-) to positive (+), the meshing sound is likely to occur.

However, when the two gears 45 and 48 are helical gears instead of spur gears, the meshing ratio becomes large, so that the occurrence of the impact noise between the two teeth due to the torque fluctuation is sufficiently suppressed. it can.

Further, by using a helical gear, the driven gear 45 is pressed against either the side surface of the sleeve 33a or the side surface of the cam 26 when either positive or negative torque is applied. Since the co-rotating torque is generated in the rotation direction due to the friction, the torque changes as shown by the broken line in FIG. 7, so that the negative (−) torque decreases (closes to zero) or changes to the positive (+) side. In addition, the inversion phenomenon of the driven gear 45 is unlikely to occur, and the effect of reducing the gear tapping sound can be obtained from this point.

Further, since the helical gear has a high meshing ratio, the tooth strength is increased even in the same module, so that the tooth width can be reduced correspondingly, and as a result, the sleeve 33
a can be formed wide. Therefore, the coupling strength of the sleeve 33a (the second flange portion 33) to the drive shaft 21 can be increased.

At both ends of the large-diameter portion 46a of the control shaft 46, the movement in the axial direction (thrust direction) caused by the gears 45 and 48 being spur gears is used.
The flanges 46b, 46b for regulating at 8 are formed.

[0056]

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 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 on 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 it is possible to prevent the center of the annular disk from shifting due to the load. 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 apparatus can be further reduced.

Further, according to the present invention, at one end of the transmission member,
Since the cam ring is press-fitted and fixed, the forming process can be performed by considering only the centering of each without considering the coaxiality of the two, thereby improving the forming workability.

Further, since the driven gear is formed integrally with the transmission member, high precision coaxiality between the two can be obtained from the beginning, so that the forming work can be easily performed in combination with the fact that the cam ring is formed separately. In addition, the cost can be reduced.

Further, according to the third aspect of the present invention, since the driven gear and the driving gear are formed in a helical shape, it is possible to sufficiently suppress the impact sound between the teeth due to the torque fluctuation of the camshaft. At the same time, smooth rotation can be obtained.

[Brief description of the drawings]

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

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

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

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

5A is a characteristic diagram of an angular velocity ratio between a drive shaft and a 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. 6 is an essential part cross-sectional view showing a second embodiment of the present invention.

FIG. 7 is a characteristic diagram showing a torque fluctuation of a driven gear and a drive gear accompanying a torque fluctuation of a camshaft.

FIG. 8 is a sectional view of a main part showing a conventional device.

9 is a view as viewed in the direction indicated by the arrow C in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 ... Drive shaft 21a ... Oil supply passage 22 ... Camshaft 23 ... Intake valve 31 ... 1st flange part 33 ... 2nd flange part 36, 37 ... 1st, 2nd pin 38 ... Annular disk 41 ... Transmission mechanism 42 ... Transmission member 43 Drive mechanism 44 Cam ring 45 Driven gear 48 Drive gear

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shingo Motoda 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. Inside

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, a sliding pin interposed between the annular disk and each of the flange portions to link the two, and the annular disk A drive mechanism for controlling the eccentric rotation position via a transmission mechanism, wherein an outer peripheral surface of the drive shaft and an inner peripheral surface of an insertion hole of an annular disk through which the drive shaft is inserted. Rotate cam ring between Only, said annular disk, while allowing movably supported eccentrically rotate the drive shaft through the cam ring, said transmission mechanism,
A transmission member rotatably provided between an outer peripheral surface of the drive shaft and an inner peripheral surface of the camshaft, wherein the cam ring is press-fitted and fixed to one end of the transmission member. Exhaust valve drive control device. 2. A cam having a drive shaft rotatably driven by an engine, and a cam divided into cylinders and provided on an outer periphery of the drive shaft so as to be relatively rotatable, and having a cam on the outer periphery for opening and closing intake and exhaust valves. 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, a sliding pin interposed between the annular disk and each of the flange portions to link the two, and the annular disk A drive mechanism for controlling the eccentric rotation position via a transmission mechanism, wherein an outer peripheral surface of the drive shaft and an inner peripheral surface of an insertion hole of an annular disk through which the drive shaft is inserted. Rotate cam ring between Only, said annular disk, while allowing movably supported eccentrically rotate the drive shaft through the cam ring, said transmission mechanism,
A transmission member rotatably provided between an outer peripheral surface of the drive shaft and an inner peripheral surface of the cam shaft, a drive gear linked to the drive mechanism, and a driven gear meshed with the drive gear; An intake / exhaust valve drive control device for an internal combustion engine, wherein one end of a transmission member is connected to the cam ring, and the driven gear is integrally provided at the other end of the transmission member. 3. 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 the 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, a sliding pin interposed between the annular disk and each of the flange portions to link the two, and the annular disk A drive mechanism for controlling the eccentric rotation position via a transmission mechanism, wherein an outer peripheral surface of the drive shaft and an inner peripheral surface of an insertion hole of an annular disk through which the drive shaft is inserted. Rotate cam ring between Only, said annular disk, while allowing movably supported eccentrically rotate the drive shaft through the cam ring, said transmission mechanism,
A transmission member rotatably provided between an outer peripheral surface of the drive shaft and an inner peripheral surface of the cam shaft, a drive gear linked to the drive mechanism, and a driven gear meshed with the drive gear; An intake / exhaust valve drive control device for an internal combustion engine, wherein the cam ring is connected to one end of a transmission member, and the drive gear and the driven gear are formed in a tooth shape.