JP2581585Y2 - Valve timing control device for internal combustion engine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing control device for variably controlling the opening / closing timing of intake and exhaust valves of an internal combustion engine in accordance with an operation state.

[0002]

2. Description of the Related Art Various conventional valve timing control devices have been provided, examples of which are disclosed in U.S. Pat. No. 4,535,731 and improved versions of the invention described in the publication. An example is described in Japanese Utility Model Application No. 2-19537 filed earlier by the present applicant.

As shown in FIG. 2, the valve timing control device filed by the present applicant employs a cylindrical driven sprocket 1 to which a driving force is transmitted from a crankshaft of an engine, and a rotational force of the driven sprocket 1. For example, a camshaft 2 integrally having a drive cam for opening and closing an intake valve is meshed with the sprocket 1 and the camshaft 2, and the relative rotation phase of the two 1 and 2 with the movement in the left-right axis direction. And a drive mechanism 4 for moving the cylindrical gear 3 in the left-right axial direction.

In the driven sprocket 1, an annular holding member 6 is fixed to the front end of a cylindrical main body 5 by caulking, and inner teeth 7 are formed on the inner peripheral surface of the cylindrical main body 5. On the other hand, the camshaft 2 has outer teeth 10 formed on an outer peripheral surface of a sleeve 9 fixed to one end 2 a by bolts 8.

The cylindrical gear 3 is formed by a front gear component 11 and a rear gear component 12 divided into two parts from a direction perpendicular to the axis. As shown in FIG. 3, the two gear components 11 and 12 have helical inner and outer teeth 11a, 11b, 12a, which mesh with the inner teeth 7 and the outer teeth 8, respectively.
12b are formed, and are elastically connected in a direction approaching each other by the spring force of a connecting pin 13 penetrating the center of the inside and a coil spring 14 wound around the head side outer periphery of the connecting pin 13. . Further, each of the gear components 11 and 12 is provided with each of the internal and external teeth 11a, 12a, 11b, 1
The inner teeth 7 of the driven sprocket 1 are pinched and supported (pressed) between the tooth side surfaces of the external teeth 11b and 12b by the spring force of the coil spring 14 by shifting the apparent tooth streaks of 2b. The outer teeth 10 of the sleeve 9 are clamped and supported between the side faces of the inner teeth 11a and 12a so as to suppress the generation of tapping noise between the teeth due to the fluctuation of the rotational torque of the camshaft due to the backlash between the teeth. It has become.

The drive mechanism 4 includes a hydraulic circuit 16 for supplying and discharging hydraulic pressure to two pressure receiving chambers 15a and 15b of a pressure chamber 15 provided at a front end side of the cylindrical gear 3; And a compression spring 17 elastically mounted at the end.
A three-way solenoid valve 18 is provided on the upstream side of the hydraulic circuit 16, and a hydraulic switching mechanism 19 including a spool valve 19a and an electromagnetic actuator 19b is provided on the front end of the sleeve 9 on the downstream side. .

When the engine is under a low load, the controller 20 outputs an OFF signal (non-energized) to the solenoid valve 18 and the solenoid actuator 19b, respectively, so that the oil supply passage 16
a is closed. Therefore, the pressure oil pumped from the oil pump 21 is discharged from the drain passage 18a and the supply to the first pressure receiving chamber 15a is cut off. Therefore, the cylindrical gear 3 moves to the left to the maximum by the spring force of the compression spring 17, and converts the relative rotation phase between the driven sprocket 1 and the camshaft 2 to one side.

On the other hand, when the load shifts from the low load range to the middle load range, an ON signal (energization) is output to the solenoid valve 18 so that the pressure oil from the oil pump 21 flows through the oil supply passage 16a and the first oil passage 16c. Then, it is introduced into the first pressure receiving chamber 15a. Accordingly, the movable member 22 provided in the pressure chamber 15 moves rightward in the figure until it hits the stopper portions 23 and 24, and moves the cylindrical gear 3 rightward by a predetermined amount.
The driven sprocket 1 and the camshaft 2 relatively rotate by a predetermined amount toward the other side.

Further, when shifting to the high load region, an ON signal is also output to the electromagnetic actuator 19b, and the drive rod 19c causes the spool valve 19a to move the spool valve 19a.
The spool valve 19a presses against the spring pressure of 9d to make the communication passage 16b communicate with the second oil passage portion 16d, while the drain hole 16e communicates with the outside. For this reason, the hydraulic pressure in the first pressure receiving chamber 15a is discharged to the outside, and the pressure oil is introduced into the second pressure receiving chamber 15b to move the movable member 22 to the left to the maximum, and at the same time, the cylindrical gear 3 is further moved rightward. As a result, the driven sprocket 1 and the camshaft 2 rotate relative to each other at the maximum.

Therefore, the driven sprocket 1 and the camshaft 2 can be stably held in any intermediate relative rotation phase movement instead of simply performing relative rotation conversion in two steps.

[0011]

However, in the invention according to the prior application, the engine operating state shifts from the low load range to the medium load range as described above, and the ON signal is sent to the solenoid valve 18 and the like. The movable member 22 is output and the front edge 11 of the front-side gear component 11 of the cylindrical gear 3 is increased with the increase in the pressure of the first pressure receiving chamber 15a.
c, and at the same time, the front gear component 11 presses the rear gear component 12, so that the two move backward with the two components 11 and 12 constantly pressed against each other. That is, the two 11 and 12 move rearward while always trying to approach each other with a strong combined force of the spring force of the spring 14 and the pressing force of the movable member 22. Therefore, as shown in FIG. 3, the clamping force (pressing force) of each of the outer teeth 11b and 12b against the inner teeth 7 of the two 11 and 12 and the clamping force of each of the inner teeth 11a and 12a against the outer teeth 10 are further increased. A large sliding friction force is generated between the teeth 11a, 11b, 12a, 12b. As a result, there is a possibility that the moving speed of the cylindrical gear 3 decreases, and the responsiveness of the valve timing control deteriorates.

The engine operating state shifts from a high load range to a low load range, and the cylindrical gear 3 is moved by the spring force of the compression spring 17.
A similar problem is caused when the camera is moved forward.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. In particular, each gear component of a cylindrical gear divided in the axial direction is connected to a connecting pin and a spring member.
Elastically connected in the approaching direction by the connecting means configured as described above , while loosely inserting into one side of the gear component and
The connecting pin fixed to the other gear component and the drive
And the pressing force of the drive mechanism acting from one of the gear constituent parts through the connection pin.
The transmission is directly transmitted to the other gear component .

[0014]

According to the present invention having the above construction, when the pressing force of the drive mechanism acts on, for example, one of the gear components, the pressing force directly acts on one end of the connecting pin of the connecting means.
Since it is transmitted directly from the connecting pin to the gear component on the other side,
With the movement of the other gear component in one direction, the one gear component moves while being pulled. That is, when the cylindrical gear moves in one direction, the two gear constituent parts are opposed to each other against the spring force of the spring member due to the sliding frictional resistance between the teeth.
The force acts in the direction away from. For this reason, the pinching force of the inner and outer teeth of the inner and outer teeth of the two gear components with respect to the inner teeth of the rotating body and the outer teeth of the camshaft is slightly reduced, and the sliding friction resistance during the movement of the cylindrical gear is reduced. Mobility is obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIG. Note that this embodiment is also applied to the intake valve side, and the basic configuration is the same as that of the prior application. Therefore, common components are denoted by the same reference numerals and described briefly.

That is, in the figure, 1 is a driven sprocket which is a rotating body, 2 is a camshaft in which a sleeve 9 is fixed to a front end by a bolt 8, 3 is a cylindrical gear which converts the relative rotational phase of the two, 1 and 2, Reference numeral 4 denotes a drive mechanism for moving the cylindrical gear 3 in the left-right axial direction.

The driven sprocket 1 has inner teeth 7 formed on the inner peripheral surface of a cylindrical main body 5 whose front end is closed by a holding member 6, while the camshaft 2 has outer teeth formed on the outer peripheral surface of a sleeve 9. 10 are formed.

The cylindrical gear 3 is composed of a front gear component 11 and a rear gear component 12 divided into two parts from a direction perpendicular to the axis, and these two parts 11 and 12 have inner teeth 7 and outer teeth on the inner and outer circumferences. 10, the internal and external teeth 11a, 11b, 12a,
12b are formed, and each of the internal teeth 11b is formed.
a, 12a and the external teeth 11b, 12b are slightly shifted in the circumferential direction from the apparent tooth traces. The two gear components 11 and 12 are formed in a substantially U-shape in vertical cross section. Through holes 11c and 12c are formed in the opposed bottom walls in the central axis direction, and the through holes 11c and 12c are formed in the through holes 11c and 12c. They are connected by connecting pins 30 arranged through.

That is, the connecting pin 30 is
a is loosely inserted into the through hole 11c of the front gear component 11 and is press-fitted and fixed in the through hole 12c of the rear gear component 12, so that the two 11, 12 are separated from each other through the through holes 11c, 12c. They are movably connected in the tangential direction. The connecting pin 30 is formed such that the outer end face 30c of the head 30b projects a predetermined amount from the front end face 11d of the front gear component 11 when the bottom wall surfaces of the two gear components 11 and 12 are in contact with each other. Have been. Further, the two 11 and 12 are urged in directions approaching each other by a spring force of a coil spring 14 which is a spring member elastically mounted between the concave groove bottom wall of the front gear component 11 and the connecting pin head 30b. Have been. The connecting means is constituted by the connecting pin 30 and the coil spring 14.

The driving mechanism 4 includes a pressure chamber 1 formed between the front end face 11a of the front gear component 11 and the holding member 6.
5 and the first pressure receiving chamber 15a and the second pressure receiving chamber 1
Annular movable member 2 which slides in the axial direction while being separated from 5b
2, a hydraulic circuit 16 for supplying and discharging hydraulic pressure to and from each of the pressure receiving chambers 15a and 15b, a rear gear forming unit 12 and a gear unit 1.
and a compression spring 17 which is elastically mounted between the inner end surface of the cylindrical gear a and biases the cylindrical gear 3 forward.

The movable member 22 is located at a substantially middle position of the pressure chamber 15 by stepped annular stoppers 23 and 24 provided on an inner periphery of a substantially front end of the cylindrical main body 5 and an outer periphery of a substantially center side of the sleeve 9, respectively. Further backward movement is restricted, and the front end face 22a is moved to the maximum rightward movement position.
Are always in contact with the outer end face 30c of the head of the connecting pin 30. The hydraulic circuit 16 includes an oil supply passage 16 formed in the axial direction of the cylinder head 25, the cam bearing 26 and the bolt 8, the pressure receiving chambers 15 a and 15 b, and the oil supply passage 16.
a and the first and second oil passage portions 1 that appropriately communicate
6c, 16d, and a three-way solenoid valve 18 on the upstream side.
However, a hydraulic pressure switching mechanism 19 including a spool valve 19a and an electromagnetic actuator 19b is provided on the downstream side, respectively.

The solenoid valve 18 is turned on by the controller 20 according to the change in the engine operating state, as described above.
N-OFF control is performed to move the cylindrical gear 3 in the left-right axis direction based on the supply / discharge action of hydraulic pressure to and from the pressure receiving chambers 15a and 15b and the spring force of the compression spring 17. Here, when the engine operating state shifts from, for example, a low-load region to a medium-load region, an ON signal is output to the solenoid valve 18 and the pressure oil from the oil pump 21 is introduced into the first pressure receiving chamber 15a. As the internal pressure of the first pressure receiving chamber 15a increases, the movable member 22
It moves backward (rightward in the figure) until it hits 3, 24. Therefore, the movable member 22 presses the outer end face 30c of the head of the connecting pin 30 with the front end face 22a, and this pressing force is directly transmitted to the rear gear component 12 through the through hole 11c. Therefore, when the rear gear component 12 moves rightward in the drawing, the front gear component 11
4 is pulled by the connecting pin 30 while being urged leftward in the drawing (toward the movable member 22) against the spring force of FIG. That is, during the rightward movement of the two gear components 11, 12, a force acts in a direction separating from each other due to sliding friction between the teeth 11a, 11b, 7, 10. Therefore,
The clamping force of each of the external teeth 11b and 12b with respect to the inner teeth 7 and the clamping force of each of the internal teeth 11a and 12a with respect to the outer teeth 10 decrease, and the sliding friction resistance between the tooth side surfaces decreases. Smooth movement to the right. As a result, the phase conversion speed of the relative rotation of the driven sprocket 1 and the camshaft 2 in one direction is increased, and the control response of the valve timing is improved.

The present invention is not limited to the above-described embodiment. For example, the connecting pin 30 is disposed in the reverse direction, the coil spring 14 is provided in the concave groove of the rear gear component 12, and the compression spring 17 is provided. Can also be transmitted directly to the front-side gear component 11. Also, by combining each of them, the hydraulic pressure of the pressure chamber
It is also possible to directly transmit the spring force of the compression springs 17 to the front gear component 11, respectively. The present apparatus can be applied to the exhaust valve side or both the intake valve side and the exhaust valve side.

[0024]

As is apparent from the above description, according to the valve timing control apparatus for an internal combustion engine according to the present invention, the respective gear components of the cylindrical gear are elastically connected in the approaching direction by the connecting means. As a result, it is possible to sufficiently suppress the generation of a tapping sound due to the backlash of each tooth due to the fluctuation of the rotational torque of the camshaft, and to connect the pressing force of the drive mechanism acting from one of the gear components. means of
Since the gear components are directly transmitted to the other gear components via the connecting pins , a force acts in a direction in which the respective gear components move away from each other during movement. Therefore, the rotating body,
The sliding friction resistance between the teeth of the camshaft and the cylindrical gear is reduced, and smooth movement of the cylindrical gear is obtained. As a result, the relative rotation phase conversion speed between the rotating body and the camshaft is increased, and the control response of the valve timing is improved.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view showing a valve timing control device according to the prior application.

FIG. 3 is an expanded view of the conventional part.

[Explanation of symbols]

1 ... driven sprocket (rotating body), 2 ... camshaft,
3 ... cylindrical gear, 4 ... drive mechanism, 11 ... front gear component,
12: rear gear component, 13, 30: connecting pin (connecting means), 14: coil spring (connecting means), 15: pressure chamber, 17: compression spring.

Claims (1)

(57) [Scope of request for utility model registration] 1. A rotator driven by an engine and a camshaft to which a rotational force is transmitted from the rotator are axially divided and at least one of the inner and outer circumferences is formed as a helical tooth. A valve timing control device that meshes a cylindrical gear and moves the cylindrical gear in the axial direction of the camshaft via a driving mechanism, thereby converting a relative rotation phase between the rotating body and the camshaft. Each divided gear component of the cylindrical gear is called a connecting pin.
It is elastically connected in the approaching direction by a connecting means constituted by a spring member, and the inside of the gear component on one side is loosened.
The connecting pin inserted and fixed to the other gear component
And the drive mechanism are directly linked to each other, and the pressing force of the drive mechanism acting from one of the gear components is applied to the connection pin.
A valve timing control device for an internal combustion engine, wherein the valve timing control device is directly transmitted to a gear component on the other side via a gear .