JPH10205311A - Valve timing adjusting device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve timing adjusting device for improving phase control accuracy and decreasing electric power consumption. SOLUTION: An internal member 26 is helical spline-connected to a cam pulley 2 and a camshaft 1. When the phase of the camshaft 1 is advanced, the rotation of a spline guide 32 is not regulated by a one-way clutch 28 fixed by a worm 33, and therefore, the forward movement of an external thread member 16 is not disturbed. In intermediate holding, the rotation in the reverse direction of the spline guide 32 is regulated by the one-way clutch 28, and the position of the external thread member 16 is held. When the phase of the camshaft 1 is delayed, the external thread member 16 is moved rearward by the rotation of the worm 33. Accordingly, since the operation of a lock pin is not needed before and after the phase changing operation, phase control accuracy can be improved. Moreover, in intermediate holding, since a coil 23 and a DC motor are not electrified, electric power consumption can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine (hereinafter referred to as "internal combustion engine").
The present invention relates to a valve timing adjusting device for changing at least one of the opening and closing timing of an intake valve and an exhaust valve of an “internal combustion engine” (hereinafter, “opening / closing timing” is referred to as valve timing) according to operating conditions.

[0002]

2. Description of the Related Art In recent years, a valve timing adjusting device for changing at least one of an intake valve and an exhaust valve of an engine in accordance with operating conditions has been proposed. For example, by providing an intermediate member between the driving side rotating member and the driven side rotating member via a helical spline, and moving the intermediate member,
One that changes the valve timing is known.

FIG. 3 shows an example of such a valve timing adjusting device disclosed in Japanese Patent Application Laid-Open No. Hei 7-26917. In FIG. 3, an intermediate member 83 is provided between a driving side rotating member 81 and a cam shaft 82 as a driven side rotating member via helical splines 87 and 88, and the intermediate member 83 is provided.
Are fixed to the driving side rotating member 81 by lock pins 84. In the valve timing adjusting device 300, in the advance angle operation, after the lock pin 84 is released, the disk member 85 which is screwed with the intermediate member 83 and normally rotated integrally is braked, and the intermediate rotation is performed using the relative rotation. Member 8
3 is moved by screw feed, and after reaching the target phase difference, the drive-side rotating member 81 and the intermediate member 8 are locked by the lock pin 84.
3 is fixed. In the retard operation, when the lock pin 84 is released, the speed of the disk member 85 is increased by the force of the spiral spring 86, the intermediate member 83 is moved in the retard direction, and after reaching the target phase difference, the lock pin The drive side rotating member 81 and the intermediate member 83 are fixed by 84.

[0004]

However, in the valve timing adjusting device 300, since the lock pin 84 is operated before and after the phase change operation, the operation for the phase change becomes complicated, and the phase control accuracy deteriorates. There was a problem. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described conventional problem, and has as its object to provide a valve timing adjusting device that improves phase control accuracy.

Another object of the present invention is to provide a valve timing adjusting device that reduces energy consumption such as electric power. Still another object of the present invention is to provide a valve timing adjusting device capable of simplifying a control mechanism.

[0006]

According to a first aspect of the present invention, there is provided a valve timing adjusting apparatus comprising a driving side rotating member, a driven side rotating member, a phase changing member, a phase control device, and a lock mechanism. The control device includes an advancing angle control means for advancing the phase of the driven side rotating member with respect to the driving side rotating member, and a retarding angle controlling means for delaying the phase of the driven side rotating member with respect to the driving side rotating member. Because of this, the operation for changing the phase can be simplified. Therefore, phase control accuracy can be improved, and responsiveness can be improved.

According to the valve timing adjusting apparatus of the present invention, the advance angle control means applies the rotational braking to the phase changing member to move the phase changing member in the axial direction, and the driven side rotating member Is a mechanism for advancing the relative rotational phase difference with respect to the driving-side rotating member, so that the relative rotational phase difference of the driven-side rotating member with respect to the driving-side rotating member is advanced only by adding the rotational braking resistance to the phase changing member. be able to. Therefore, energy other than at the time of transition to advance the relative rotation phase difference is not required, and energy consumption such as electric power can be reduced.

According to the third aspect of the present invention, the screw portion moves in the axial direction together with the phase changing member, and the lock mechanism is provided between the driving side rotating member and the driven side rotating member. The two rotating members are engaged with a shaft that does not rotate integrally with a screw part, and furthermore, since this is a mechanism that regulates one direction of the rotation of the shaft, the operation of the lock pin and the like before and after the phase change operation is performed. do not need. Therefore, phase control accuracy can be improved, and responsiveness can be improved. Further, since there is no need to perform feedback control for maintaining the relative rotation phase difference between the driving-side rotating member and the driven-side rotating member at a constant value, the control mechanism can be simplified.

According to the valve timing adjusting device of the present invention, the retard control means controls the amount of movement of the phase changing member which moves in the retard direction by the force of the spring. A mechanism that retards the relative rotational phase difference of the driven-side rotating member with respect to the driving-side rotating member by controlling the power. Therefore, only by controlling the braking force applied to the lock mechanism, the driving side of the driven-side rotating member The relative rotational phase difference with respect to the rotating member can be retarded. Therefore, energy other than at the time of transition to retard the relative rotation phase difference is not required, and energy consumption such as electric power can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a valve timing adjusting apparatus according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a camshaft as a driven-side rotating member that opens and closes an intake valve and an exhaust valve (not shown) of the engine,
Reference numeral 2 denotes a cam pulley as a driving-side rotating member that is synchronously driven from a crankshaft (not shown) of the engine via a timing belt. In FIG. 1, the X1 direction is the front side of the engine, and X2 is the rear side of the engine. Hereinafter, for convenience, the X1 direction is referred to as “forward”, and the X2 direction is referred to as “rearward”.

The cam pulley 2 is fixed to a pulley holder 7, a pulley sleeve 5 and a brake plate support 8 by bolts 6.
And is fixed integrally. The pulley holder 7 is fitted to the camshaft 1 at the center bore 7a. The camshaft sleep 3 is fixed so as to rotate integrally with the camshaft 1 by a bolt 4 and a knock pin 3a. The pulley holder 7 is held so as to be slidable and rotatable with respect to the camshaft 1.

The piston spline 9 is connected to the pulley sleeve 5 and the camshaft sleeve 3 via helical spline portions 9a and 9b. Piston 1
2 and the piston spline 9
And the ring 11 are fixed to each other. A spring 45 is provided between the piston 12 and the piston pin 10.
And a spring 13 is provided between the piston 12 and the intermediate ring 46 to absorb the impact. Further, the piston 12 and the intermediate member 26 as a phase changing member having the square screw portion 27
4 are integrally fixed.

The spring support 18 and the brake plate 19 are integrally fixed by a plurality of bolts 22. A ring member 21 is provided in a space surrounded by the spring support 18, the brake plate 19, and the brake plate support 8. The ring member 21
The relative movement of the brake plate 19 relative to the brake plate support 8 in the axial direction, that is, in the front-rear direction, is restricted, and relative rotation is enabled. The brake plate support 8 and the spring support 18 are connected via a spiral spring 17. Spiral spring 17
Are biased so that the relative rotational phase difference between the brake plate support 8 and the brake plate 19 fixed integrally with the spring support 18 is minimized. The lining 20 is spline-coupled to the brake plate 19 and is movable relative to the brake plate 19 in the axial direction, that is, in the front-back direction. The brake plate 19 is connected to the intermediate member 26 via a square screw portion 27 provided at the center.

Normally, the brake plate 19 rotates integrally with the cam pulley 2, the camshaft 1, and the intermediate member 26. However, when the coil 23 provided inside the housing 35 is energized, the lining 20 is attracted to the coil 23 and the brake plate 19 is braked. As a result, a relative rotation difference occurs between the brake plate 19 and the intermediate member 26. Note that the brake plate 19 and the coil 23 correspond to the advance angle control means described in the claims.

The intermediate member 26 and the male screw member 16 serving as a screw portion are connected via a bearing 15 so as to be relatively rotatable. The bearing 15 includes circlips 15 a and 15 b and a stepped portion 16 a provided on the male screw member 16.
And has been fixed by. The external thread member 16 and the spline guide 32 are connected by a screw or a helical spline. The spline guide 32 is rotatably held on a housing 35 via a bearing 31. A worm wheel 29 is provided outside the spline guide 32 via a one-way clutch 28 supported by a one-way clutch support plate 30.
The one-way clutch 28 does not restrict the rotation of the spline guide 32 when the camshaft 1 advances with respect to the cam pulley 2, that is, when the intermediate member 26 and the external thread member 16 move forward, and the one-way clutch 28 retards. In other words, the rotation of the spline guide 32 when the intermediate member 26 and the external thread member 16 move rearward is restricted. The worm 33 is adapted to mesh with the worm wheel 29 and applies braking to the one-way clutch 28. The worm 33 is connected to a rotation shaft of a DC motor 34 supported by a housing 35, and transmits the rotation torque of the DC motor 34 to the spline guide 32 via a worm wheel 29 and a one-way clutch 28. The spline guide 32 and the one-way clutch 28 correspond to a lock mechanism described in claims.
Worm wheel 29, worm 33 and DC motor 34
"" Corresponds to the retard control means described in the claims.

The housing 35 is fixed to a cylinder head 49 of the engine by a plurality of bolts 48. The housing 35 has a seal support 47 fixed by a plurality of bolts 24.
An oil seal 25 is provided between the first and second brake plate supports 8. In addition, the oil passages 36, 37, 3
8, 39 are provided.

The operation of the valve timing control device 100 for advancing the phase of the camshaft 1 with respect to the cam pulley 2 will be described below. The camshaft 1 is advanced when the intermediate member 26 is moved forward, and is retarded when the intermediate member 26 is moved backward. When the engine is rotating, the coil 23 is first energized to apply braking to the brake plate 19. At this time,
A relative rotational phase difference is generated between the brake plate 19 and the intermediate member 26, and the spiral screw 17
7, the intermediate member 26 moves forward. With the movement of the intermediate member 26, the piston spline 9 and the male screw member 16 move forward. Piston spline 9
Causes the phase of the camshaft 1 to advance. When the intermediate member 26, the piston spline 9 and the male screw member 16 move forward in the advance angle, the spline guide 32 can rotate by the action of the one-way clutch 28, so that the male screw member 16 moves forward. It is possible to move. When the target phase is reached, the coil 23 is turned off. Then, the intermediate member tends to move rearward due to the force applied to the square screw portion 27 from the brake plate 19 by the urging of the spiral spring 17 and the force applied to the piston spline 9 from the helical spline portions 9a and 9b. However, the rotation of the spline guide 32 in the reverse direction is restricted by the one-way clutch 28, so that the position of the male screw member 16 is maintained. As a result, a desired phase can be maintained.

Next, the operation for retarding the phase of the camshaft 1 will be described below. First, the DC motor 34 is energized to rotate the worm 33. One-way clutch 2
The rotation of the worm 33 is transmitted to the spline guide 32 via the worm wheel 29 and the one-way clutch 28 because the rotation of the worm 8 is restricted in the retard direction. The intermediate member 26 holds the brake plate 1 by the urging of the spiral spring 17.
9 from the helical spline portions 9a and 9b and the force applied to the piston spline 9 from the helical spline portions 9a and 9b.
With the rotation of 2, the male screw member 16 relatively easily moves backward. When the target phase is reached, DC
When the motor 34 is turned off, the rotation of the worm wheel 29 and the spline guide 32 is stopped, and the male screw member 1 is turned off.
The position of No. 6 is maintained. As a result, a desired phase can be maintained.

The valve timing control device 1 of the first embodiment
00, when the phase of the camshaft 1 is advanced, the one-way clutch 28 fixed by the worm 33 is used.
As a result, the rotation of the spline guide 32 is not restricted, so that the forward movement of the male screw member 16 is not hindered. Also, during the intermediate holding, the one-way clutch 28 restricts the rotation of the spline guide 32 in the reverse direction, so that the position of the male screw member 16 is held. When the phase of the camshaft 1 is further retarded, the male screw member 16 moves rearward due to the rotation of the worm 33. Therefore, since the operation of the lock pin or the like is not required before and after the phase change operation, the phase control accuracy can be improved, and the responsiveness can be improved.

In the first embodiment, since the phase control of the camshaft 1 is performed not by hydraulic control but by electromagnetic control, it is possible to control the camshaft 1 immediately after starting according to the operating state of the engine. In the intermediate holding, the spiral spring 17
And the worm 33 holds the retarding force of the helical spline portions 9a and 9b.
The C motor 34 is turned off. Therefore, power consumption can be reduced. Further, since no feedback control for maintaining the phase difference at a constant value is not necessary, the control mechanism can be simplified. Further, since no resistance is applied to the camshaft 1, wear of the camshaft 1 can be reduced, and power loss of the engine can be reduced.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
Shown in Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and only different points from the first embodiment will be described to avoid duplication of description. As shown in FIG. 2, in the valve timing control device 200 of the second embodiment, a one-way clutch outer ring 40 is provided outside the spline guide 32 via a one-way clutch 28 supported by a one-way clutch support plate 30. A projection 41 is provided around the outer ring 40 of the one-way clutch. Clutch plate 4
2 is spline-coupled to the housing 35 and is movable in the axial direction. The clutch plate 42 is provided with a spring 43.
Thus, the protruding portion 41 is pressed with a relatively strong force. By energizing the coil 44 provided inside the housing 35, the clutch plate 42 is attracted to the coil 44. The clutch plate 42 and the coil 44
"" Corresponds to the retard control means described in the claims.

In the valve timing control device 200, the operation for advancing the phase of the camshaft 1 with respect to the cam pulley 2 is the same as in the first embodiment. Therefore, the description of the advance operation will be omitted, and the operation when the phase of the camshaft 1 is retarded will be described below. The camshaft 1 is advanced when the intermediate member 26 is moved forward, and is retarded when the intermediate member 26 is moved backward.

First, the coil 44 is energized and the clutch plate 4
2 is attracted to the coil 44 side, and the clutch plate 42 and the protrusion 41 are separated. The intermediate member 26 has a force applied to the square screw portion 27 from the brake plate 19 by the urging of the spiral spring 17,
Since it receives the rearward force and the force applied to the piston spline 9 from the helical spline portions 9a and 9b,
When the spline guide 32 is made rotatable, the male screw member 16 relatively easily moves backward. When the coil 44 is turned off when the target phase is reached, the clutch plate 42 is pressed against the protrusion 41 again, and the rotation of the spline guide 32 is restricted.
The position of No. 6 is maintained. As a result, a desired phase can be maintained.

The valve timing control device 2 of the second embodiment
00, when the phase of the camshaft 1 is advanced, the one-way clutch 2 fixed by the clutch plate 42 is used.
Since the rotation of the spline guide 32 is not restricted by 8, the forward movement of the male screw member 16 is not hindered. Also, during the intermediate holding, the one-way clutch 28 restricts the rotation of the spline guide 32 in the reverse direction, so that the position of the male screw member 16 is held. When the phase of the camshaft 1 is further retarded, the male screw member 16 moves in the retard direction by moving the clutch plate 42 away from the protrusion 41. Therefore, the operation of the lock pin or the like is not required before and after the phase change operation, so that the phase control accuracy can be improved and the responsiveness can be improved.

In the second embodiment, since the phase control of the camshaft 1 is performed not by the hydraulic control but by the electromagnetic control, it is possible to control the camshaft 1 immediately after the start according to the operating state of the engine. In the intermediate holding, the spiral spring 17
Since the retarding force of the helical spline portions 9a and 9b is held by the clutch plate 42, the coils 23 and 44 are turned off. Therefore, power consumption can be reduced. Further, since no feedback control for maintaining the phase difference at a constant value is not necessary, the control mechanism can be simplified. Further, since no resistance is applied to the camshaft 1, wear of the camshaft 1 can be reduced, and power loss of the engine can be reduced.

In some embodiments of the present invention, the male screw member 1
6 and the spline guide 32 are connected by a screw or a helical spline, but in the present invention, they may be connected by a ball screw mechanism having higher transmission efficiency. In the embodiments of the present invention, the brake plate 19 and the intermediate member 26 are connected by the square screw portion 27. However, in the present invention, the brake plate 19 and the intermediate member 26 may be connected by using a triangular screw or a trapezoidal screw.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a valve timing adjusting device according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a valve timing adjusting device according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a conventional valve timing adjusting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cam shaft (driven side rotating member) 2 Cam pulley (driving side rotating member) 3 Cam shaft sleeve 5 Pulley sleeve 7 Pulley holder 8 Brake plate support 9 Piston spline 10 Piston pin 11 Ring 12 Piston 13 Spring 16 Male screw member (Screw) 17) Spiral spring 18 Spring support 19 Brake plate (advance angle control means) 20 Lining 23 Coil (advance angle control means) 24 Bolt 26 Intermediate member (Phase changing member) 27 Square screw portion 28 One-way clutch (Lock mechanism) Reference Signs List 29 worm wheel (retard control means) 30 one-way clutch support plate 32 spline guide (lock mechanism) 33 worm (retard control means) 34 DC motor (retard control means) 35 housing 40 one-way clutch outer ring 41 disc-shaped protrusion 4 2 Clutch plate (retard control means) 43 Spring 44 Coil (retard control means) 100, 200, 300 Valve timing adjusting device

Claims (4)

[Claims] A driving-side rotating member, a driven-side rotating member provided coaxially with the driving-side rotating member and supported so as to be relatively rotatable, and rotationally driven by the driving-side rotating member; A phase changing member disposed between the two rotating members to move the two rotating members relative to each other to change a rotation phase by moving in the axial direction, and a phase control to move the phase changing member in the axial direction Device, and a lock mechanism for holding a phase difference, wherein the phase control device is configured to advance the phase of the driven-side rotating member with respect to the driving-side rotating member, and the drive-side rotating member And a retard control means for retarding the phase of the driven-side rotating member. 2. The advance angle control means moves the phase change member in the axial direction by applying rotational braking to the phase change member, and rotates the driven rotation member relative to the drive rotation member. 2. The valve timing adjusting device for an internal combustion engine according to claim 1, wherein the valve timing adjusting device is a mechanism for advancing a phase difference. 3. A locking mechanism, comprising: a screw portion that moves in the axial direction together with the phase changing member; wherein the locking mechanism is provided between the driving-side rotating member and the driven-side rotating member and is integrated with the two rotating members. 2. The valve timing adjusting device for an internal combustion engine according to claim 1, wherein the valve timing adjusting device is engaged with a shaft that does not rotate by the screw portion, and further regulates one direction of rotation of the shaft. 4. The drive-side rotation by controlling a braking force applied to a lock mechanism for controlling a movement amount of a phase change member that moves in a retard direction by a force of a spring. 2. The valve timing adjusting device for an internal combustion engine according to claim 1, wherein the valve timing adjusting device is a mechanism for retarding a relative rotational phase difference of a member with respect to the driving side rotating member.