JP2000161027A - Valve timing adjustment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve timing adjustment device with can facilitate assembling, reduce assembling man-hour, and prevent operating malfunction caused by imperfect assembling of an actuator. SOLUTION: One end of a torsion spring 60 is fixed to a fixation portion 150 formed on a peripheral wall 51 of a shoe housing 50. The other end of the torsion spring 60 is fixed to a fixation hole 62 formed on a projection 61 of a bush 6. It is thus possible to assemble the torsion spring 60 on the outside of the shoe housing 50 after assembling a vane rotor 4 and the shoe housing 50. Axial length of a chain sprocket 8 can be comparatively reduced. Assembling operation is facilitated, while man-hour of assembling operation is reduced. It is thus possible to prevent assembling the vane rotor 4 and the those housing 50 in the state that one is inclined to the other. Malfunction in operation caused by imperfect assembling of an actuator is prevented.

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 opening / closing timing of at least one of an intake valve and an exhaust valve of an “internal combustion engine” (hereinafter referred to as an engine)
The present invention relates to a valve timing adjusting device for changing “opening / closing timing” according to operating conditions.

[0002]

2. Description of the Related Art Conventionally, a camshaft is driven by a driving force transmitting means such as a chain sprocket which rotates synchronously with a crankshaft of an engine, and the intake valve and the intake valve are driven by a phase difference due to relative rotation between the driving force transmitting means and the camshaft. 2. Description of the Related Art A vane-type valve timing adjusting device that controls valve timing of at least one of exhaust valves is known.

A vane type valve timing adjusting device is
A vane that rotates with the camshaft is housed in a housing that rotates with the driving force transmitting means. By adjusting the relative rotational phase difference of the vane with respect to the housing by hydraulic pressure, the camshaft and the driving force transmitting means are relatively rotated, and at least one of the intake valve and the exhaust valve according to the operating conditions of the engine. One of the valve timings is adjusted.

[0004]

SUMMARY OF THE INVENTION An object of a phase control valve timing control device for controlling the opening and closing timing of an engine valve is to improve engine stability, improve fuel economy, or reduce exhaust emissions. When the load of this type of engine is low, the amount of intake air is small, so it is desirable that the amount of residual exhaust gas that deteriorates combustion in the cylinder of the engine is small. During a period in which the intake valve and the exhaust valve are simultaneously open (overlap period), the intake side is at a negative pressure due to the throttle and the exhaust side is at a positive pressure. May cause a fire. Therefore, it is required that the closing timing of the exhaust valve be early and the opening timing of the intake valve be late. Further, by delaying the closing timing of the intake valve, pumping loss can be reduced and fuel efficiency can be improved. Therefore, at the time of idling operation and start-up, it is necessary to control the basic phase so that the exhaust valve closes earlier and the intake valve opens later. Here, the condition on the intake side of this basic phase is the most retarded angle, and the condition on the exhaust side is the most advanced angle.

However, when the engine has a medium load or more, the EGR amount is controlled to reduce the pumping loss by using the internal EGR.
In order to improve fuel efficiency and reduce exhaust emissions, it is necessary to advance the valve opening timing on the intake side or delay the valve closing timing on the exhaust side. That is, the intake valve is controlled in the advance direction, and the exhaust valve is controlled in the retard direction.

Further, at full engine load, a large amount of air needs to be introduced into the cylinder of the engine. Therefore, in the low speed range, the intake valve is closed early to prevent backflow to the manifold, and in the high speed range, air is It is necessary to close the intake valve later by utilizing the inertia of the intake valve. On the exhaust side, it is necessary to control the exhaust valve so that the exhaust pulsation can be used to the maximum, and to control the exhaust valve to the most advanced angle when the exhaust pulsation cannot be used. That is, the exhaust side controls the exhaust valve from the most advanced angle to the retarded angle in accordance with the engine load from low load,
It is necessary to control in the advance direction again.

[0007] At this time, if the operating conditions change, it is desirable that the intake and exhaust valves can be quickly controlled to the required phase. However, when the intake and exhaust valves cannot be controlled, problems such as engine misfire and unstable combustion occur. Usually, the hydraulic pump of the engine is driven by the crankshaft. However, as a result, the amount of discharged oil changes depending on the number of revolutions of the engine, and the amount of discharged oil decreases at low rotation speed. For this reason, especially at a high oil temperature, the hydraulic pressure may decrease due to leakage and a decrease in viscosity, and the actuator may not operate. At this time, since the intake side is retarded by the driving torque of the camshaft, it can be the basic phase. However, if an actuator with the same hydraulic piston area as the intake side is used on the exhaust side, it will not be possible to control to the basic position, and residual gas will increase in the engine cylinder, causing misfiring or stopping the engine. May be.

Therefore, in the valve timing adjusting device disclosed in Japanese Patent Application Laid-Open No. 9-264110, the intake side is moved to a retard position or the exhaust side is moved to an advanced position by using the biasing force of a torsion spring. Solves the above problem.

However, due to the structure of the torsion spring, it is necessary to form the spring all around the camshaft. In the valve timing adjusting device disclosed in Japanese Patent Application Laid-Open No. 9-264110, a torsion spring is housed inside a vane type variable phase actuator. Here, when assembling the valve timing adjustment device,
The torsion spring is assembled inside the actuator with an initial torque applied. For this reason, it is necessary to assemble the bolts for fastening the housing containing the vanes and the chain sprocket in a state where the initial torque is applied to the torsion spring, which makes the assembling work difficult and increases the number of assembling steps. There was a problem.

Further, the torsion spring is structurally
Since a moment is generated not only in the torsional direction but also in the axial direction, there is a risk that the vane blades or the chain sprocket may be inclined when the above housing and the chain sprocket are fastened. In order for the vane to swing relative to the housing and the chain sprocket, a gap needs to be formed between the vane and the inner wall of the housing and the chain sprocket that forms a space for accommodating the vane. However, if the bolts are tightened while the vane blades or the chain sprocket are inclined, the above-mentioned gap is not formed, and the vane is locked, so that there is a problem that the relative swing cannot be performed.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a valve timing adjusting device which can easily perform an assembling operation and can reduce the number of assembling steps. I do.

Another object of the present invention is to provide a valve timing adjusting device for preventing a malfunction due to an improper assembly of an actuator. It is still another object of the present invention to provide a valve timing adjusting device that is small in size and easy to secure a mounting space for mounting on an engine. Still another object of the present invention is to provide a valve timing adjusting device that can reduce the manufacturing cost with a simple configuration.

[0013]

According to the valve timing adjusting apparatus of the present invention, the vane is moved in the direction in which the driven shaft is advanced with respect to the drive shaft or the direction in which the driven shaft is retarded with respect to the drive shaft. The biasing means for biasing the member is provided outside the housing member. For this reason, after assembling the vane member and the housing member, the urging means can be assembled outside the housing member. Therefore, the assembling work is easy and the number of assembling steps can be reduced.
Furthermore, after assembling the vane member and the housing member,
By attaching the urging means to the outside of the housing member, it is possible to prevent the vane member and the housing member from being assembled while one of the vane member and the housing member is inclined with respect to the other. Therefore,
It is possible to prevent an operation failure due to an assembly failure of the actuator.

According to the valve timing adjusting device of the second aspect of the present invention, since the housing member has the fixing portion for fixing one end of the urging means, for example, the drive shaft or the driven shaft By fixing the other end of the biasing means to a bush or the like which is fastened together with the vane member to the other side and is rotatably fitted to the housing member,
It is not necessary to provide the housing part of the urging means in the housing member.
For this reason, the axial length of the housing member can be made relatively short. Therefore, the physique can be reduced in size, and a mounting space for mounting on the engine can be easily secured. Further, since the housing member has the guide portion for guiding the inside of the urging means, the operation of the urging means can be made smooth and the operation failure can be prevented.

According to the valve timing adjusting device of the third aspect of the present invention, the bush fastened together with the vane member to the other of the drive shaft and the driven shaft and fitted to the housing member so as to be relatively rotatable is provided by the biasing means. Has a fixing part for fixing one end of the urging means, so that the housing part of the urging means need not be provided in the housing member by fixing the other end of the urging means to the housing member. . For this reason, the axial length of the housing member can be made relatively short. Therefore, the physique can be reduced in size, and a mounting space for mounting on the engine can be easily secured. Further, since there is no need to provide a special member for fixing one end of the urging means, the manufacturing cost can be reduced with a simple configuration. Furthermore, since the bush has the guide portion for guiding the inside of the urging means, the operation of the urging means can be made smooth and the operation failure can be prevented.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIGS. 1 to 3 show an engine valve timing adjusting apparatus according to a first embodiment of the present invention. The valve timing adjusting device 100 of the first embodiment is a hydraulically controlled valve timing adjusting device that controls the valve timing of an exhaust valve.

The chain sprocket 8 shown in FIGS. 1 and 2 is coupled with a crankshaft as a drive shaft of an engine (not shown) by a timing chain (not shown) to transmit a driving force, and rotates in synchronization with the crankshaft. The shoe housing 50 includes a peripheral wall 51 and a front part 52, and the front part 52 and the chain sprocket 8 are connected by bolts 53. Peripheral wall 51
Has a fixing portion 150 protruding in the radial direction for fixing one end of the torsion spring 60 described later. The camshaft 1 as a driven shaft receives a driving force from the chain sprocket 8 and opens and closes an exhaust valve (not shown). The camshaft 1 is supported by a cylinder head (not shown), and is rotatable relative to the chain sprocket 8 with a predetermined phase difference. The chain sprocket 8 and the camshaft 1 rotate clockwise as viewed from the left in FIGS. Hereinafter, this rotation direction is referred to as an advance direction.

The chain sprocket 8 and the shoe housing 50 constitute a housing member. Both end surfaces in the axial direction of the vane rotor 4 are covered by the chain sprocket 8 and the front portion 52 of the shoe housing 50. Chain sprocket 8 and shoe housing 5
Reference numeral 0 denotes a driving-side rotating body, which is coaxially connected to each other by bolts 53.

The vane rotor 4 is integrally connected to the camshaft 1 by bolts 5, and the bush 6 is press-fitted and supported by the vane rotor 4 to form a driven-side rotating body. The bush 6 has a protruding portion 61 protruding in the radial direction, and a fixing hole 62 formed on the protruding portion 61 for fixing the other end of the torsion spring 60. The camshaft 1 and the bush 6 are fitted to the front portion 52 of the shoe housing 50 so as to be relatively rotatable. Therefore, the camshaft 1, the vane rotor 4 and the bush 6 are rotatable coaxially with respect to the chain sprocket 8 and the shoe housing 50.

A torsion spring 60 as an urging means is provided outside the shoe housing 50, and the inside of the torsion spring 60 is provided on the peripheral wall 5 of the shoe housing 50.
Guided to 1. Here, the peripheral wall 51 constitutes a guide portion. The torsion spring 60 has a fixed portion 150 having one end provided on the peripheral wall 51 of the shoe housing 50.
, And the other end is fixed to a fixing hole 62 formed in the protrusion 61 of the bush 6. The torsion spring 60 moves the vane rotor 4 and the bush 6 in the direction in which the vane rotor 4 and the bush 6 advance with respect to the chain sprocket 8 and the shoe housing 50, that is, in the direction in which the camshaft 1 advances with respect to the crankshaft.
Is energizing.

As shown in FIG.
The peripheral wall 51 has shoes 51a, 51b, 51c formed in a trapezoidal shape at substantially equal intervals in the circumferential direction. Shoe 5
Fan-shaped spaces 55 as accommodation chambers for accommodating vanes 4a, 4b, 4c as vane members are formed in three circumferential gaps of 1a, 51b, 51c, respectively.
The inner peripheral surfaces of the shoes 51a, 51b, 51c are formed in an arc-shaped cross section.

The vane rotor 4 has vanes 4a, 4b, 4c at substantially equal intervals in the circumferential direction.
4c is rotatably accommodated in a fan-shaped space 55 formed in a circumferential gap between the shoes 51a, 51b, 51c. Arrows indicating the retard direction and the advance direction shown in FIG. 3 indicate the retard direction and the advance direction of the vane rotor 4 with respect to the peripheral wall 51. In FIG. 3, each vane is in each fan-shaped space 5.
5, the vane rotor 4 is at the most advanced position with respect to the peripheral wall 51. The most advanced position is vane 4
The leading side of c is locked to the retard side of the shoe 51c.

The seal member 9 is fitted on the outer peripheral wall of the vanes 4a, 4b, 4c. The seal member 90 is fitted on the inner peripheral wall of the shoes 51a, 51b, 51c. Outer peripheral wall of vane rotor 4 and peripheral wall 51 of shoe housing 50
A small clearance is provided between the inner peripheral wall and the inner peripheral wall, and leakage of hydraulic oil between the hydraulic chambers is prevented by the seal members 9 and 90 through the clearance.

The guide ring 91 is pressed into and held by the inner wall of the vane 4a, and a stopper piston 97 is inserted into the guide ring 91. As shown in FIG. 1, the stopper piston 97 is formed in a cylindrical shape with a bottom having substantially the same outer diameter, and includes a cylindrical portion 97a having a bottom and a flange portion 97b provided at an opening end of the cylindrical portion 97a. Become. The stopper piston 97 is accommodated in the guide ring 91 so as to be slidable in the axial direction of the camshaft 1. The stopper piston 97 is urged by a spring 96 toward the chain sprocket. A fitting ring 54 having a tapered hole 54a is press-fitted and held in a stopper hole formed in the front portion 52 of the shoe housing 50.
Can be fitted in the tapered hole 54a at the most advanced position shown in FIG. When the stopper piston 97 is fitted in the tapered hole 54a and the stopper piston 97 is in contact with the tapered hole 54a in the rotational direction, the relative rotation of the vane rotor 4 with respect to the peripheral wall 51 is restricted. That is, the stopper piston 97 and the tapered hole 54a are in the restrained position at the most advanced position.

The hydraulic chamber 18 on the left side of the flange portion 97b is
It communicates with an advance hydraulic chamber 85 described later via an oil passage (not shown). The hydraulic chamber 27 formed on the distal end side of the cylindrical portion 97a communicates with a later-described retard hydraulic chamber 80 via an oil passage (not shown). The area of the first pressure receiving surface of the flange portion 97b that receives the oil pressure of the hydraulic chamber 18 is set to be smaller than the area of the second pressure receiving surface of the cylindrical portion 97a that receives the oil pressure of the hydraulic chamber 27. The first pressure receiving surface and the second pressure receiving surface
The force that the pressure receiving surface receives from the hydraulic oil in the hydraulic chamber 18 and the hydraulic chamber 27 is transmitted from the taper hole 54a to the stopper piston 97.
It works in the direction to get out of. The pressure receiving area of the first pressure receiving surface is substantially equal to the area of the annular portion corresponding to the diameter difference between the flange portion 97b and the cylindrical portion 97a, and the pressure receiving area of the second pressure receiving surface is the cylindrical portion 9
7a approximately equal to the cross-sectional area. When hydraulic oil of a predetermined pressure or more is supplied to the advance hydraulic chamber 85 or the retard hydraulic chamber 80, the stopper piston 97 comes out of the tapered hole 54a against the urging force of the spring 96 due to the hydraulic pressure of the hydraulic oil.

Position of Stopper Piston 97 and Tapered Hole 5
The relationship with the position of 4 a
When the vane rotor 4 is at the most advanced position with respect to the crankshaft 1, that is, when the camshaft 1 is at the most advanced position with respect to the crankshaft, the stopper piston 97 can be fitted into the tapered hole 54a by the urging force of the spring 96. Is set to

As shown in FIG. 3, a retard hydraulic chamber 80 is formed between the shoe 51a and the vane 4a.
And a vane 4b, a retard hydraulic chamber 81 is formed, and between the shoe 51c and the vane 4c, a retard hydraulic chamber 82 is formed. An advanced hydraulic chamber 83 is formed between the shoe 51a and the vane 4b, an advanced hydraulic chamber 84 is formed between the shoe 51b and the vane 4c, and an advanced hydraulic pressure chamber is formed between the shoe 51c and the vane 4a. A chamber 85 is formed.

As shown in FIG. 1, the stopper piston 97
Back pressure chamber 30 communicates with a communication passage 70 formed in the vane 4a. The communication passage 70 is open to the atmosphere at an oil lubrication space of the engine (not shown) via an oil passage 71 formed in the chain sprocket 8 at the most advanced position.
At the most advanced position, the back pressure chamber 30 is open to the atmosphere.
Therefore, in the most advanced position, the stopper piston 97
Movement is not hindered.

The vane rotor 4 is provided with an oil passage 12 at a contact portion with the camshaft 1 and communicates with the retard hydraulic chambers 80, 81 and 82 via an oil passage 13 shown in FIG. I have. The oil passage 12 communicates with a hydraulic pump or drain as drive means via an oil passage 14 formed in the camshaft 1 and a switching valve (not shown).
The hydraulic pump also serves as a drive source for engine lubrication oil. Further, the oil passage 15 shown in FIG. 3 communicates with a hydraulic pump or a drain via a switching valve, and the advance hydraulic chambers 83, 84,
And 85.

Next, the operation of the valve timing adjusting device 100 having the above configuration will be described. (1) When the engine stops normally, the retard hydraulic chambers 80 and 8
1 and 82 are released to the drain side, and each advance hydraulic chamber 83, 8
The switching valves 4 and 85 are controlled so as to be maintained in a state where the operating oil pressure is applied. Then, the vane rotor 4 moves to the most advanced position with respect to the peripheral wall 51 of the shoe housing 50, and the front portion 52 and the vane rotor 4 are moved by the restraining means.
Are connected to each other, so that the camshaft 1
Is held at the most advanced position.

In the first embodiment, since the valve opening periods of the exhaust valve and the intake valve do not overlap in the most advanced state shown in FIG. 3, the internal EGR amount is reduced and the engine operates normally. Can be started. Even when the engine is started, the front portion 52 and the vane rotor 4 are held in a connected state by the restraining means, so that the peripheral wall is kept until the operating oil pressure applied to each oil passage and each oil pressure chamber becomes larger than a predetermined pressure. The camshaft 1 is at the most advanced position with respect to 51.

(2) When the engine shifts to the normal operation and the operating pressure oil having a hydraulic pressure larger than the predetermined pressure is introduced into each oil passage and each hydraulic chamber, the fluctuation of the camshaft 1 during idling at a high oil temperature. Pressure acts on the second pressure receiving surface due to the negative peak torque of the torque, and the coupling between the front portion 52 and the vane rotor 4 by the restraining means is released. At this time, the restraint between the front part 52 and the vane rotor 4 can be quickly released without the stopper piston 97 being caught by a shearing force. Therefore, the retard hydraulic chambers 80, 81, 82
And the operating hydraulic pressure applied to the advance hydraulic chambers 83, 84, 85, against the urging force of the torsion spring 60, and
1, the vane rotor 4 is relatively rotated, and the relative phase difference of the camshaft 1 with respect to the peripheral wall 51 is adjusted.

In the first embodiment of the present invention described above, the torsion spring 6 is provided outside the shoe housing 50.
Since 0 is provided, the torsion spring 60 can be mounted outside the shoe housing 50 after the vane rotor 4 and the shoe housing 50 have been mounted. Therefore, the assembling work is easy and the number of assembling steps can be reduced. Further, since the vane rotor 4 and the shoe housing 50 are prevented from being assembled with one inclined with respect to the other, it is possible to prevent a malfunction due to an improper assembly of the actuator.

Further, in the first embodiment, one end of the torsion spring 60 is fixed to a fixing portion 150 provided on the peripheral wall 51 of the shoe housing 50, and a fixing hole formed in the projecting portion 61 of the bush 6. By fixing the other end of the torsion spring 60 to 62, the chain sprocket 8 does not need to be provided with a spring accommodating portion.
The axial length of the chain sprocket 8 can be made relatively short. Therefore, the physique can be reduced in size, and a mounting space for mounting on the engine can be easily secured. Further, since the peripheral wall 51 also serves as a guide portion for guiding the inside of the torsion spring 60, the operation of the torsion spring 60 can be made smooth and operation failure can be prevented.

(Second Embodiment) Next, a second embodiment in which the torsion spring 60 of the first embodiment shown in FIGS. 1 and 2 is provided outside the bush 6 will be described with reference to FIGS. Will be explained. Other configurations are the same as those of the first embodiment,
The same components are denoted by the same reference numerals.

As shown in FIGS. 4 and 5, the shoe housing 500 as a housing member includes a peripheral wall 501 and a front part 502, and the front part 502 and the chain sprocket 8 are connected by bolts 53. The front part 502 includes a torsion spring 1 described later.
60 has a fixing hole 503 for fixing the other end. The bush 600 is press-fitted and supported by the vane rotor 4 and forms a driven-side rotating body. The bush 600
It has a large diameter portion 601 and a fixing portion 602 provided on the large diameter portion 601 and protruding in the radial direction for fixing one end of the torsion spring 160. The camshaft 1 and the bush 600 are respectively connected to the shoe housing 5.
00 is fitted to the front part 502 so as to be relatively rotatable. Therefore, the camshaft 1, the vane rotor 4 and the bush 600 are rotatable coaxially with respect to the chain sprocket 8 and the shoe housing 500.

The torsion spring 160 as the urging means
Is provided outside the bush 600, and the inside of the torsion spring 160 is guided by the large diameter portion 601.
Here, the large diameter part 601 constitutes a guide part. One end of the torsion spring 160 is fixed to a fixing portion 602 provided on the large-diameter portion 601 of the bush 600, and the other end is provided in a fixing hole 503 formed in the front portion 502 of the shoe housing 500. Fixed. The torsion spring 160 urges the vane rotor 4 and the bush 600 in a direction in which the vane rotor 4 and the bush 600 advance with respect to the chain sprocket 8 and the shoe housing 500, that is, in a direction in which the camshaft 1 advances with respect to the crankshaft. ing.

In the second embodiment, since the torsion spring 160 is provided outside the bush 600,
After assembling the vane rotor 4 and the shoe housing 500, the torsion spring 160 is
It can be assembled outside. Therefore, the assembling work is easy and the number of assembling steps can be reduced. Further, since the vane rotor 4 and the shoe housing 500 are prevented from being assembled with one inclined with respect to the other, operation failure due to improper assembly of the actuator can be prevented.

Further, in the second embodiment, the bush 6
One end of the torsion spring 160 is fixed to a fixing portion 602 provided in the large diameter portion 601 of the shoe housing 500, and a fixing hole 50 formed in the front portion 502 of the shoe housing 500.
By fixing the other end of the torsion spring 160 to 3, there is no need to provide a spring accommodating portion in the chain sprocket 8, so that the axial length of the chain sprocket 8 can be relatively shortened. . Therefore, the physique can be reduced in size, and a mounting space for mounting on the engine can be easily secured. Furthermore, since it is not necessary to provide a special member for fixing one end of the torsion spring 160, the manufacturing cost can be reduced with a simple configuration. Further, since the large-diameter portion 601 guides the inside of the torsion spring 160, the operation of the torsion spring 160 can be made smooth, and malfunction can be prevented.

Furthermore, in the second embodiment, there is no need to provide a special member for fixing one end of the torsion spring 160, so that the manufacturing cost can be reduced with a simple configuration. .

In the embodiments of the present invention described above,
The front portion of the shoe housing and the vane rotor 4 are connected at the most advanced position by the restraining means so that the opening periods of the exhaust valve and the intake valve do not overlap. However, in the present invention, the engine is normally started and operated. The opening period of the exhaust valve and the opening period of the intake valve may overlap as long as the range can be shifted to the state, and the coupling position of the housing member and the vane member by the restraining means may be on the retard side from the most advanced position. .

In the embodiments described above, the vane rotor 4 having three vanes has been described. However, in the present invention, the number of vanes may be one or more as long as the configuration allows.

In the embodiments, the stopper piston 97 moves in the axial direction of the vane rotor 4 to fit into the tapered hole. However, in the present invention, the stopper piston moves in the radial direction of the vane rotor to taper. It is also possible to adopt a configuration in which the stopper piston is accommodated in the chain sprocket.

Further, in the plurality of embodiments, the configuration in which the rotational driving force of the crankshaft is transmitted to the camshaft by the chain sprocket is adopted, but a configuration using a timing pulley, a timing gear, or the like may be adopted.
It is also possible to receive the driving force of the crankshaft as the drive shaft by the vane rotor, and rotate the camshaft as the driven shaft and the housing unit integrally.

In a plurality of embodiments, the present invention is applied to a valve timing adjusting device for an exhaust valve. However, the present invention is not limited to this. For example, an OHC engine or an OHV engine is provided with a valve timing adjusting device. Can also be applied. At this time, the valve timing adjustment device causes the valve opening timing of the intake / exhaust valve to move in parallel in the retard direction, so that the fuel efficiency can be improved by moving the valve opening timing in parallel. Also in this case, the reference position at the time of starting the engine is the most advanced position, so that the same effects as those of the above-described embodiments can be obtained.

Further, the present invention is applicable to a valve timing adjusting device for an intake valve. The valve timing adjusting device of the intake valve is always receiving a force in the retard direction, similarly to the valve timing adjusting device of the exhaust valve. Therefore, by providing a torsion spring as the urging means, the operating speed (responsiveness) of the valve timing can be improved. In this case, it is preferable that the urging force of the torsion spring is set to be smaller than the force in the retard direction received by the valve timing adjusting device when the engine is started. By setting the biasing force of the torsion spring in this way, it can be held at the most retarded position which is the reference position at the time of starting.

[Brief description of the drawings]

FIG. 1 is a sectional view of a valve timing adjusting apparatus according to a first embodiment of the present invention, taken along line II of FIG. 2;

FIG. 2 is an external view showing a valve timing adjusting device according to a first embodiment of the present invention.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a longitudinal sectional view showing a valve timing adjusting device according to a second embodiment of the present invention.

FIG. 5 is a view in the direction of arrow V in FIG. 2;

[Description of Signs] 1 Camshaft (driven shaft) 4 Vane rotor 4a, 4b, 4c Vane (vane member) 8 Chain sprocket (housing member) 50 Shoe housing (housing member) 51 Peripheral wall (guide portion) 52 Front part 60 Screw Spring (biasing means) 61 Projecting part 62 Fixing hole 80, 81, 82 Retarder hydraulic chamber 83, 84, 85 Advance hydraulic chamber 100 Valve timing adjusting device 150 Fixing part 500 Shoe housing (housing member) 501 Peripheral wall 502 Front Part 503 fixing hole 600 bush 601 large diameter part (guide part) 602 fixing part

Claims (3)

[Claims] 1. A driving force transmission system for transmitting driving force from a driving shaft of an internal combustion engine to a driven shaft that opens and closes at least one of an intake valve and an exhaust valve of the internal combustion engine, wherein the driving shaft or the driven shaft is provided. A housing member that rotates together with one of the drive shaft and the other of the drive shaft and the driven shaft, and rotates relative to the housing member only within a predetermined angular range in a housing chamber formed in the housing member. A vane member accommodated therein, an advance chamber for rotating one of the housing member and the vane member relative to the other in an advance angle direction with respect to the other by fluid pressure, and the housing member and the vane member by fluid pressure. A fluid-driven driving means for supplying a working fluid to a retard chamber for rotating one of the vane members relative to the other in a retard direction, Biasing means provided outside the housing member and biasing the vane member in a direction in which the driven shaft is advanced with respect to the drive shaft, or in a direction in which the driven shaft is retarded with respect to the drive shaft; A valve timing adjusting device, comprising: 2. The device according to claim 1, wherein the housing member has a fixing portion for fixing one end of the urging means, and a guide portion for guiding the inside of the urging means. The valve timing adjusting device according to the above. 3. A bush fastened together with the vane member to the other of the drive shaft and the driven shaft together with the housing member so as to be relatively rotatable, wherein the bush is one of the urging means. The valve timing adjusting device according to claim 1, further comprising a fixing portion for fixing an end portion, and a guide portion for guiding the inside of the urging means.