JPH1193627A - Valve timing adjuster for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve timing adjuster for an engine capable of preventing a misfire or combustion instability of the engine with a simple constitution. SOLUTION: An area of an end surface 12b on the side of a retard hydraulic chamber 20 of a piston 12 of a valve timing adjuster 100 for intake air is set smaller than that of the end surface on the side of a lead hydraulic chamber 20 of a piston 12 of a valve timing adjuster 100 for exhaust gas. Consequently, a cam shaft 1 of the valve timing adjuster 100 for exhaust gas can be moved in a leading direction with respect to a crankshaft even at an oil pressure at which a camshaft 1 of the valve timing adjuster 100 for intake air cannot be moved in the leading direction with respect to the crankshaft. Therefore, it is possible to enhance startability of the engine. Furthermore, a basic phase can be controlled in which a closing timing of an exhaust valve is early and an opening timing of an intake valve is late even in the case where a hydraulic pump discharge flow rate is small, for example, at a low engine speed, thus preventing a misfire or combustion instability of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing adjusting device for an internal combustion engine for adjusting the opening / closing timing of an intake valve and an exhaust valve.

[0002]

2. Description of the Related Art Conventionally, a valve timing adjusting apparatus for adjusting the opening / closing timing of an intake valve and an exhaust valve (hereinafter, "opening / closing timing" is referred to as valve timing) of an internal combustion engine (hereinafter, "internal combustion engine" is referred to as an engine) is known. The driving torque is transmitted from a crankshaft as a driving shaft of the engine to a camshaft as a driven shaft via driving force transmitting means. As the driving force transmitting means, for example, a ring gear or a vane is employed.

The ring gear meshes with splines of a timing pulley and a camshaft, and at least one of them meshes with a helical spline.
Then, the camshaft and the timing pulley are relatively rotated by moving the ring gear in the axial direction by hydraulic pressure, and the valve timing of the intake valve and the exhaust valve is adjusted according to the operating conditions of the engine. I have.

In the vane type, a vane that rotates with a cam shaft is housed in a housing that rotates with a timing pulley. By adjusting the relative rotational phase difference of the vane with respect to the housing by hydraulic pressure, the cam shaft and the timing pulley are relatively rotated, and the valve timing between the intake valve and the exhaust valve is adjusted according to the operating conditions of the engine. doing.

[0005]

SUMMARY OF THE INVENTION A phase control valve timing adjusting device for controlling the opening and closing timing of an engine valve is intended to improve engine stability, improve fuel efficiency, or reduce exhaust emissions. Since the amount of intake air is small at low load, it is desirable that the amount of residual exhaust gas that deteriorates combustion in the cylinder of the engine be small. During a period in which the intake valve and the exhaust valve are simultaneously open (overlap period), the intake side has a negative pressure due to the throttle and the exhaust side has a positive pressure.
Exhaust gas may be blown back to the intake side, resulting in deterioration of combustion or misfire. 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, if the closing timing of the intake valve is late, 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 load of the engine, a large amount of air must be introduced into the cylinder of the engine.At low speeds, the intake valve closes quickly to prevent backflow to the manifold, and at high speeds, the inertia of air is used to slow down. The intake valve needs to be closed. 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, on the exhaust side, it is necessary to control the exhaust valve from the most advanced angle to the retarded direction and to control the exhaust valve again in the advanced angle according to the load of the engine from low load.

However, if the operating conditions change at this time, it is desirable that the intake and exhaust valves can be quickly controlled to the required phase. If 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 a crankshaft. However, as a result, the discharge oil amount changes depending on the engine speed, and the discharge oil amount 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.

As a prior art, there is known a valve timing adjusting device provided with a dedicated hydraulic pump so that the hydraulic pressure can always be increased. However, in such a valve timing adjusting device provided with such a dedicated hydraulic pump, the problem of low hydraulic pressure can be solved, but it is difficult to install it in a limited space, and the device cost increases. There is.

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 for an engine which can prevent misfire and unstable combustion of the engine with a simple structure. And

[0010]

According to the valve timing adjusting device for an engine according to the first aspect of the present invention, the driving force of the driving shaft is transmitted to the first driven shaft for opening and closing the intake valve of the internal combustion engine. A first drive-side rotating body that rotates with the shaft,
And a first driving force transmitting means having a first driven-side rotating body that rotates together with the first driven shaft, and a driving force of the driving shaft transmitted to a second driven shaft that opens and closes an exhaust valve of the internal combustion engine; A second drive-side rotating body that rotates with the drive shaft;
And a second driving force transmitting means having a second driven-side rotating body that rotates together with the driven shaft. The second driving force transmitting means has a larger operating force than the first driving force transmitting means. doing. For this reason, even when the amount of oil discharged at low engine speed is small or the oil pressure at high oil temperature decreases,
The overlap period in which the exhaust valve and the intake valve overlap and open can be reduced at least to the extent that the engine can be started. Therefore, the startability of the engine is improved, and misfire and unstable combustion of the engine can be prevented. further,
The amount of fuel that is drawn from the intake valve and becomes unburned fuel and discharged from the exhaust valve can be reduced.

According to the valve timing adjusting device for an engine of the present invention, the first driving force transmitting means is a fluid for relatively rotating the first driving side rotating body and the first driven side rotating body. A first pressure receiving surface on which pressure acts, and a second driving force transmitting means on which a second pressure acting on the second driving side rotating body and the second driven side rotating body is actuated by a fluid pressure that relatively rotates the second driving side rotating body and the second driven side rotating body; It has a pressure receiving surface, and the first pressure receiving surface has a smaller pressure receiving area than the second pressure receiving surface. For this reason, the second driving force transmitting means operates with a smaller operating force than the first driving force transmitting means. Therefore, even when the amount of oil discharged at low engine speed is small or the oil pressure at high oil temperature is low, the overlap period in which the exhaust valve and the intake valve overlap and open is at least as long as the engine can be started. Therefore, it is possible to prevent engine misfire and unstable combustion.

According to the valve timing adjusting device for an engine according to the third aspect of the present invention, the first driven side rotating body is
When the fluid pressure acts on the first pressure receiving surface, the fluid rotates relatively to the first driving-side rotating body in the advancing direction, and the second driven-side rotating body has the fluid pressure applied to the second pressure receiving surface. By acting, it is relatively rotated in the retard direction with respect to the second driving-side rotating body. Therefore, even when the amount of discharge oil at the time of low engine rotation is small or the oil pressure at the time of high oil temperature decreases, at least the engine can be started in the overlap period in which the exhaust valve and the intake valve overlap and open. To the extent possible. Therefore, misfire and unstable combustion of the engine can be prevented.

According to the valve timing adjusting device for an engine of the present invention, the first driving force transmitting means connects the first driving side rotating body and the first driven side rotating body with the helical spline. A second gear for connecting the second driving-side rotating body and the second driven-side rotating body with a helical spline; The thrust force of the gear specification is set smaller than that of the first gear. For this reason, the second driving force transmitting means operates with a smaller operating force than the first driving force transmitting means. Therefore, even when the amount of oil discharged at low engine speed is small or the oil pressure at high oil temperature is low, the overlap period in which the exhaust valve and the intake valve overlap and open is at least as long as the engine can be started. Therefore, it is possible to prevent engine misfire and unstable combustion.

According to the valve timing adjusting device for an engine according to the fifth aspect of the present invention, the second gear has a smaller torsion angle or a larger pitch circle diameter than the first gear. The transmitting means operates with a smaller operating force than the first driving force transmitting means. Therefore, even when the amount of oil discharged at low engine speed is small or the oil pressure at high oil temperature is low, the overlap period in which the exhaust valve and the intake valve overlap and open is at least as long as the engine can be started. Therefore, it is possible to prevent engine misfire and unstable combustion.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plurality of examples showing the embodiments of the present invention will be described with reference to the drawings. (First Embodiment) FIGS. 1 and 2 show an engine valve timing adjusting apparatus according to a first embodiment of the present invention. FIG.
As shown in FIG. 2 and FIG. 2, the engine valve timing adjusting device of the first embodiment includes a ring gear type valve timing adjusting device 100 for an intake valve and a ring gear type valve timing adjusting device 200 for an exhaust valve. Be composed.

First, a valve timing adjusting device 100 for an intake valve will be described with reference to FIG. In FIG.
Rotational torque is transmitted from a crankshaft (not shown) as a drive shaft to a timing pulley 5, which is a first drive-side rotating body, by a timing belt (not shown). A cylindrical camshaft sleeve 4 is fixed to one end of the camshaft 1 by a bolt 2 and a pin (not shown) so as to rotate integrally with the camshaft 1 as a first driven shaft. External teeth helical splines 4a are formed on a part of the outer peripheral wall of the camshaft sleeve 4 as the first driven side rotating body. The timing pulley 5 and the camshaft 1 rotate clockwise as viewed from the left side in FIG.

The sprocket sleeve 32 and the flange member 8 together with the timing pulley 5 constitute a first driving-side rotating body, and the flange portion 32c and the annular portion 8a are assembled to the timing pulley 5 by bolts 6.
In the flange member 8, an annular portion 8a and a cylindrical portion 8b are integrally formed. The timing pulley 5 is supported by the camshaft 1 so as to be relatively rotatable by the inner surface 8c of the cylindrical portion 8b being supported by the outer peripheral wall 1a of the camshaft 1.

The sprocket sleeve 32 has a small diameter portion 32.
d and an outer cylinder having a large diameter portion 32e;
An annular flange portion 32c extending radially outward from the opposite small-diameter portion side, an inner cylinder 32b, and a circle extending radially inward from the opposite large-diameter portion side of the small-diameter portion 32d to join the outer cylinder and the inner cylinder 32b. The ring part 32f is formed integrally. Internal teeth helical splines 32a are formed on a part of the inner peripheral wall of the small diameter portion 32d.

The timing pulley 5 and the camshaft 1 are located between the camshaft sleeve 4 and the small diameter portion 32d in the radial direction.
And two arc-shaped gears 11 and 11 for relatively rotating the two. The arc-shaped gears 10 and 11 as the first driving force transmission means are formed by dividing one ring-shaped gear by a division surface including a shaft. Arc gear 1
The camshaft 1 is retarded with respect to the timing pulley 5 when the 0 and the arc gear 11 move to the retard side shown by the arrow in FIG.
Is advanced with respect to the timing pulley 5. Arc gear 1
Reference numerals 0 and 11 are alternately attached to the piston 12 in the circumferential direction, and apparently constitute one ring-shaped gear. Arc-shaped grooves 10c, 11c are provided at the upper ends of the arc-shaped gears 10, 11, respectively.
Are formed, and the retainer ring 13 is accommodated in the grooves 10c and 11c. In the state shown in FIG. 1, the retainer ring 13 is not in contact with the arc gear 10 in the axial direction. The arc gears 10, 11, the periphery of the piston 12, and the accommodation hole 12a are also filled with oil. Here, the arc gears 10 and 11 correspond to the first gear described in the claims.

The accommodating hole 12a is an arc gear 1 of the piston 12.
It is formed at a position corresponding to 0. The spring 18 is housed in the housing hole 12a, and urges the annular member 17 and the arc gear 10 in the leftward direction in FIG. The pin 14 is inserted through the piston 12 and the arc gear 11 so as to be able to reciprocate.
7 is slidably inserted through. Further, since the pin 14 is press-fitted into the retainer ring 13, the retainer ring 13 and the pin 14 move together, and constitute a part of the first driving force transmitting means. The pin 14 is the spring 1
5, the retainer ring 13 and the arc gear 11 are also urged to the right in FIG.
That is, the spring 18 is urged in a direction approaching the piston 12 in a direction opposite to the direction in which the arc gear 10 is urged.

The arc-shaped gears 10 and 11 have internal teeth helical splines 10a and 11a formed on the inner peripheral wall, and external teeth helical splines 10b and 11b are formed on the outer peripheral wall. The axial movement of the arc gears 10, 11 is possible within the compression range of the springs 18 and 15, respectively. Also, since the arc gears 10 and 11 are urged away from each other, before the arc gears 10 and 11 are interposed between the small diameter portion 32d and the camshaft sleeve 4, the external gear helical spline is provided. The axial positions of 10b, 11b and the internal tooth helical splines 10a, 11a are further shifted than in FIG.

When the arc gears 10 and 11 are interposed between the small diameter portion 32d and the camshaft sleeve 4, the arc gear 1
Reference numerals 0 and 11 deviate a small distance in the axial direction and the rotational direction of the camshaft 1 by an amount corresponding to the backlash between splines, and reduce the axial displacement as compared with the state before the interposition to reduce the small-diameter portion 32d and the cam. It is interposed between the shaft sleeve 4. The springs 18 and 15 urge the arc gears 10 and 11 with respect to the piston 12 in opposite axial directions. Due to this urging force, the arc gear 10 causes the cam shaft 1 to rotate relative to the timing pulley 5 in the retard direction, and the arc gear 11 causes the cam shaft 1 to rotate relative to the timing pulley 5 in the advance direction. give. That is, due to the urging force of the spring 18, the external helical spline 10b of the arc gear 10 retards the internal helical spline 32a in the retard direction, and the internal helical spline 10a retards the external helical spline 4a of the camshaft sleeve 4. Direction. Due to the urging force of the spring 15, the external helical spline 11b of the arc gear 11 advances the internal helical spline 32a of the small diameter portion 32d in the advance direction, and the internal helical spline 11a changes the external helical spline of the camshaft sleeve 4. 4a is pressed in the advance direction. Therefore, the arc gears 10 and 11 are respectively connected to the springs 18 and
When the intake valve is opened and closed by the biasing force of 15, the camshaft 1 is given a torque that opposes the positive and negative driving torques received when the intake valve is opened and closed, so that rattling noise due to backlash between splines can be suppressed. .

The rotation of the timing pulley 5 is transmitted to the camshaft 1 via the sprocket sleeve 32, the arc gears 10 and 11, and the camshaft sleeve 4 by the meshing of the splines. Spring 2
Numeral 2 is housed in a conical shape between the piston 12 and the flange member 8, and biases the piston 12 to the left in FIG. 1, that is, to the retard side. Since the arc-shaped gears 10 and 11 and the piston 12 are urged to the left side in FIG. 1 by the urging force of the spring 22, the camshaft 1 via the camshaft sleeve 4 is retarded with respect to the timing pulley 5. Being energized.

As described above, when the spring 18 presses the arc gear 10 in the retard direction, the camshaft sleeve 4 and the camshaft 1 are biased in the retard direction. The sum of the urging forces of the springs 18 and 22 for urging the camshaft 1 to the retard side is set to be larger than the maximum torque at the time of cranking at the time of starting the engine. Therefore, the spring 1
The urging force of the spring 22 can be reduced as compared with the case where there is no 8.

In the above configuration, the spring 1
The urging force of 5 is set smaller than the urging force of the spring 18. Thereby, when the camshaft 1 is relatively rotated in the retard direction with respect to the timing pulley 5, the frictional force in the advance direction acting between the helical splines due to the urging force of the spring 15 can be reduced. The relative rotation can be smoothly performed in the retard direction.

An advanced hydraulic chamber 19 is formed on the left side of the piston 12, and a retard hydraulic chamber 20 is formed on the right side of the piston 12.
The area of the end surface 12b of the piston 12 on the retard hydraulic chamber 20 side is determined by φD ₁ and φD ₂ shown in FIG. End face 1
The first pressure receiving portion 2b receives the operating oil pressure applied to the retard hydraulic pressure chamber 20 and relatively rotates the camshaft 1 relative to the timing pulley 5 in the retard direction. Equivalent to a surface. The advance hydraulic chamber 19 and the retard hydraulic chamber 20 are liquid-sealed by the bolt 23 and the flange member 8, and substantially liquid-sealed by the cylindrical portion 8 b of the flange member 8. The advance hydraulic chamber 19 and the retard hydraulic chamber 20 are separated by a resin seal member 40 fitted on the outer periphery of the piston 12.

The lock mechanism includes a stopper (not shown) and a spring (not shown), and a fitting hole into which the stopper fits communicates with the advance hydraulic chamber 19. The advance hydraulic chamber 19 is controlled by switching a hydraulic control valve (not shown).
Supply of pressure oil to an oil passage communicating with the retard hydraulic chamber 20 and
The flow with the discharge of the pressure oil from the oil passage is controlled. Specifically, an oil passage 4b formed in the camshaft sleeve 4 communicating with the advance hydraulic chamber 19, an oil passage 2a formed in the bolt 2,
And oil passages 1c and 1b formed in the camshaft 1;
The hydraulic control valve is switched between the oil pump side and the drain side to switch on or off, and the hydraulic pressure in the advance hydraulic chamber 19 is controlled. Further, the hydraulic control valve is switched between an oil path (not shown) communicating with the retard hydraulic chamber 20, an oil path 1f and an oil path 1d formed in the camshaft 1, and an oil pump side or a drain side, so as to conduct or shut off. Then, the hydraulic pressure in the retard hydraulic pressure chamber 20 is controlled. The balance between the hydraulic pressure of the advance hydraulic chamber 19 and the hydraulic pressure of the retard hydraulic chamber 20 causes the arc gear 1
The phase difference of the camshaft 1 with respect to the timing pulley 5 can be controlled by moving or stopping 0, 11 and the piston 12 in the axial direction.

Next, the valve timing adjusting device 200 for an exhaust valve will be described with reference to FIG. Components substantially the same as those of the valve timing adjusting device 100 for an intake valve shown in FIG. 1 are denoted by the same reference numerals. In the valve timing adjusting device 200 for the exhaust valve, the gear specification of each helical spline is such that the twist direction is the valve timing adjusting device 1 for the intake valve.
The other gear specifications are the same as those of the intake valve timing controller 100.

In FIG. 2, a cylindrical camshaft sleeve 10 is rotated by a bolt 2 and a pin (not shown) so as to rotate integrally with a camshaft 101 as a second driven shaft.
4 is fixed to one end of the camshaft 101. External teeth helical splines 104a are formed on a part of the outer peripheral wall of the camshaft sleeve 104 as the second driven-side rotating body. Timing pulley 105
The camshaft 101 rotates clockwise as viewed from the left side in FIG.

The sprocket sleeve 132 and the flange member 108, together with the timing pulley 105,
And the flange 132c and the annular portion 108a are connected to the timing pulley 105 by bolts 6.
It is attached to. Flange member 108 is annular portion 10
8a and the cylindrical portion 108b are integrally formed. The timing pulley 105 is supported by the camshaft 101 so as to be relatively rotatable because the inner side surface 108c of the cylindrical portion 108b is supported by the outer peripheral wall 101a of the camshaft 101.

The sprocket sleeve 132 has a small diameter 1
An outer cylinder having a large diameter portion 132e and a large diameter portion 132e; an annular flange portion 132c extending radially outward from a side opposite to the small diameter portion of the large diameter portion 132e; an inner cylinder 132b;
d and extends radially inward from the side opposite to the large diameter portion
and an annular portion 132f that couples b with each other. An internal tooth helical spline 132a is formed on a part of the inner peripheral wall of the small diameter portion 132d.

The camshaft sleeve 104 and the small diameter portion 13
Two arc-shaped gears 110 and two arc-shaped gears 111 for relatively rotating the timing pulley 105 and the camshaft 101 are interposed between the two in the radial direction of 2d. Second
The arc gears 110 and 111 as the driving force transmitting means of
It is formed by dividing one ring-shaped gear by a dividing surface including a shaft. When the arc gear 110 and the arc gear 111 move to the advance side indicated by the arrow in FIG.
1 is advanced with respect to the timing pulley 105, and moves to the retard side indicated by the arrow, and the camshaft 101 is retarded with respect to the timing pulley 105. Arc gears 110, 11
Arc-shaped grooves 110c and 111c are formed at the upper end of the groove 1. A retainer ring 113 is housed in the grooves 110c and 111c. In the state shown in FIG. 2, the retainer ring 113 is not in contact with the arc gear 110 in the axial direction. The arc gears 110 and 111, the periphery of the piston 112, and the accommodation hole 112a are also filled with oil. Here, the arc gears 110 and 111 correspond to the second gear described in the claims.

The receiving hole 112a is formed at a position corresponding to the arc gear 110 of the piston 112. The spring 18 is housed in the housing hole 112a, and
And the arc gear 110 is urged leftward in FIG. 2, that is, in a direction away from the piston 112. The pin 114 is reciprocally inserted through the piston 112 and the arc gear 111, and is slidably inserted through the annular member 17. Further, since the pin 114 is press-fitted into the retainer ring 113, the retainer ring 113 and the pin 114 move together, and constitute a part of the second driving force transmitting means. The pin 114 is moved by the urging force of the spring 15 in FIG.
, The retainer ring 113 and the arc gear 111 are also urged rightward in FIG. 2, that is, in a direction approaching the piston 112 in the direction opposite to the urging direction of the arc gear 110 by the spring 18. Have been.

The inner peripheral helical splines 110a, 111 are respectively provided on the inner peripheral walls of the arc gears 110, 111.
a is formed, and the external tooth helical spline 11 is formed on the outer peripheral wall.
0b and 111b are formed. Arc gear 110, 1
An axial movement of 11 is possible in the compression range of springs 18 and 15, respectively. The springs 18 and 15 urge the arc gears 110 and 111 in a direction opposite to the axial direction with respect to the piston 112, respectively. With this urging force, the arc gear 110 moves the camshaft 101 in the advance direction with respect to the timing pulley 105,
The arc gear 111 applies a torque to the timing pulley 105 to relatively rotate the camshaft 101 in the retard direction. That is, by the urging force of the spring 18,
The external gear helical spline 110b of the arc gear 110 is advanced from the internal gear helical spline 132a in the advance direction, and the internal gear helical spline 110a is connected to the camshaft sleeve 104.
Is pressed in the retard direction. Also, due to the urging force of the spring 15, the external helical spline 111b of the arc gear 111 becomes smaller in the small diameter portion 1
The internal tooth helical spline 132a of 32d presses in the retard direction, and the internal tooth helical spline 111a presses the external tooth helical spline 104a of the camshaft sleeve 104 in the retard direction. Therefore, the arc gears 110, 1
11 is provided with torque against the positive and negative driving torques received by the camshaft 101 when the exhaust valve is opened and closed by the biasing forces of the springs 18 and 15, respectively. Sound can be suppressed.

The rotation of the timing pulley 105 is transmitted to the camshaft 101 via the sprocket sleeve 132, the arc gears 110 and 111, and the camshaft sleeve 104 due to the meshing of the splines. The spring 22 is housed in a conical shape between the piston 112 and the flange member 108, and moves the piston 112 to the left in FIG.
Is energizing. Since the arc-shaped gears 110 and 111 and the piston 112 are urged to the left in FIG. 2 by the urging force of the spring 22, the camshaft sleeve 104
Via the camshaft 101 and the timing pulley 105
Are biased toward the advancing side.

The retard hydraulic chamber 11 is located on the left side of the piston 112.
9. An advanced hydraulic chamber 120 is formed on the right side of the piston 112.
Have been. End face of piston 112 on advance hydraulic chamber 120 side
The area of 112b is φD shown in FIG._ThreeAnd φD_FourDecided with
Is done. Where φD₁= ΦD _ThreeAnd φD_Four> ΦD
_TwoIt is. Therefore, the area of the end face 112b is as shown in FIG.
It is set larger than the area of the end face 12b shown. end
The surface 112b receives the operating hydraulic pressure applied to the advance hydraulic chamber 120.
To the timing pulley 105
Claims 1 is a device for relatively rotating an actuator 1 in an advance direction.
Corresponds to the second pressure receiving surface described in the range.

By controlling the switching of a hydraulic control valve (not shown), the flow of the supply of pressure oil to the oil passage communicating with the retard hydraulic chamber 119 and the advance hydraulic chamber 120 and the discharge of the pressure oil from the oil passage are controlled. Controlled. Specifically, the oil passage 10 formed in the camshaft sleeve 104 communicating with the retard hydraulic chamber 119
4b, the oil passage 2a formed in the bolt 2, and the oil passages 101c and 101b formed in the camshaft 101, and the oil pump side or the drain side are turned on or off by switching control of a hydraulic control valve, so that The hydraulic pressure in the angular hydraulic chamber 119 is controlled. Further, an oil passage (not shown) communicating with the advance hydraulic chamber 120, an oil passage 1 formed in the camshaft 101.
A hydraulic control valve is switched between the oil passage 101f and the oil passage 101d and the oil pump side or the drain side to switch on or off, thereby controlling the hydraulic pressure in the advance hydraulic chamber 120. The arc-shaped gears 110 and 111 and the piston 112 are controlled by the hydraulic pressure balance between the retard hydraulic chamber 119 and the advance hydraulic chamber 120.
Is moved or stopped in the axial direction, and the timing pulley 1
05 relative to the camshaft 101 can be controlled.

Next, the operation of the intake valve timing controller 100 and the exhaust valve 200 will be described. (1) When the engine is stopped (1-1) Valve timing adjustment device 100 for intake valve When the engine is stopped, the oil passages 4d, 2a, 1c, and 1b communicating with the advance hydraulic chamber 19 are released to the drain side, and the retard is retarded. The hydraulic control valves are switched and controlled such that the hydraulic passages 1f and 1d communicating with the hydraulic chamber 20 are maintained in a state where the operating hydraulic pressure is applied. Therefore, the arc gears 10, 11 and the piston 1
2 moves to the left side of FIG. 1, that is, the most retarded position. When the camshaft 1 relatively rotates to the most retarded position with the movement of the arc gears 10, 11 and the piston 12 to the most retarded position, the camshaft 1 and the flange member 8 are coupled by the lock mechanism. The camshaft 1 is held at the most retarded position with respect to the timing pulley 5.

(1-2) Exhaust Valve Timing Adjuster 200 When the engine stops, the oil passages 104d, 102a, 101c and 101b communicating with the retard hydraulic chamber 119 are released to the drain side, and the advance hydraulic chamber 120 Oil passage 101 communicating with
In f and 101d, the hydraulic control valve is switch-controlled so that the operating hydraulic pressure is maintained. Therefore, the arc gears 110 and 111 and the piston 112 are on the left side of FIG.
That is, it moves to the most advanced position. Arc gears 110, 111
When the camshaft 101 rotates to the most advanced position with the movement of the piston 112 to the most advanced position, the camshaft 101 and the flange member 108 are coupled by the lock mechanism. The camshaft 101 is held at the most advanced position.

(1-3) In the first embodiment, the most retarded state of the camshaft 1 shown in FIG. 1 and the camshaft 101 shown in FIG.
In the most advanced state, the exhaust valve and the intake valve are designed so that the opening periods do not overlap, so that the amount of combustion gas remaining in the cylinder of the engine, the so-called internal EGR amount, can be reduced.
The engine starts normally. (2) During engine operation (2-1) Valve timing adjusting device 100 for intake valve Until hydraulic oil is introduced into oil passages 4d, 2a, 1c and 1b and operating hydraulic pressure rises above a predetermined pressure, the cam is operated by the lock mechanism. The shaft 1 and the flange member 8 are held together.

When the operating oil pressure of the oil passages 4d, 2a, 1c, and 1b becomes larger than a predetermined pressure, the coupling between the camshaft 1 and the flange member 8 is released by the lock mechanism. Becomes relatively rotatable. The operating gears applied to the advance hydraulic chamber 19 and the retard hydraulic chamber 20 cause the arc gears 10 and 11 and the piston 12 to reciprocate in the axial direction irrespective of the urging force of the spring 22, and the cam to the timing pulley 5. The relative phase difference of the shaft 1 is adjusted.

(2-2) Valve timing adjusting device for exhaust valve 200 Until the hydraulic oil is introduced into the oil passages 104d, 102a, 101c and 101b and the hydraulic pressure rises above a predetermined pressure, the cam mechanism 101 and the camshaft 101 are locked by the lock mechanism. Flange member 10
8 is kept coupled. Oil passages 104d, 102
When the operating hydraulic pressures of a, 101c, and 101b become larger than a predetermined pressure, the coupling between the camshaft 101 and the flange member 108 is released by the lock mechanism, so that the timing pulley 105 and the camshaft 101 can be relatively rotated. . The arc-shaped gears 110 and 111 and the piston 112 reciprocate in the axial direction irrespective of the urging force of the spring 22 by operating hydraulic pressure applied to the retard hydraulic chamber 119 and the advance hydraulic chamber 120, and the cam for the timing pulley 105 The relative phase difference of the shaft 101 is adjusted.

(2-3) Since the opening period of the exhaust valve can be prevented from overlapping with the opening period of the intake valve when the engine is started, the internal EGR amount can be reduced. Therefore, the startability of the engine is improved, and the unburned fuel is prevented from being discharged into the exhaust gas, so that the purification effect of the exhaust gas is improved. In the first embodiment described above, when the engine is started, the camshaft 1 is held at the most retarded position with respect to the crankshaft, and the camshaft 101 is held at the most advanced position with respect to the crankshaft. Starts reliably and shifts to the normal operation state.

Further, the advance hydraulic chamber 12 of the piston 112
The area of the end surface 112b on the zero side is set larger than the area of the end surface 12b of the piston 12 on the retard hydraulic chamber 20 side. Therefore, for the same camshaft driving torque, the operating force for moving the arc-shaped gears 110 and 111 and the piston 112 in the advance direction is a function of moving the arc-shaped gears 10 and 11 and the piston 12 in the advance direction. Because the power is larger than the power, even if the camshaft 1 cannot move in the advance direction with respect to the crankshaft,
Can move in the advance direction with respect to the crankshaft. Therefore, even when the discharge flow rate of the hydraulic pump is low, such as when the engine is running at a low speed, it is possible to control the basic phase in which the exhaust valve closes early and the intake valve opens late, preventing engine misfiring and combustion instability. can do.

Furthermore, when it is necessary to move both the camshaft 1 and the camshaft 101 in the advance direction with respect to the crankshaft, for example, when the engine shifts from a low-speed medium load to a full load, Hydraulic oil flows into the exhaust valve timing adjusting device 200 having a lower operating oil pressure than the intake valve timing adjusting device 100,
The operation of the exhaust valve timing adjusting device 200 can be preferentially performed.

In the first embodiment, the arc gears 10 and 11, 110 and 111 are
Are urged in the directions opposite to the axis and away from each other via the pistons 12 and 112 by the urging force of the external teeth, so that the external teeth helical splines 10b and 11b are respectively opposed to the internal teeth helical splines 32a and 132a. The internal teeth helical splines 10a and 11a, 110a and 111a apply torque in opposite directions to the external teeth helical splines 4a and 104a, respectively, and abut against them. For this reason, even if the torque fluctuates in the opposite direction (positive torque) or the same direction (negative torque) as the rotational direction due to the driving torque in the rotational direction of the camshafts 1 and 101, the tooth due to the backlash of the helical spline is generated. The hitting sound can be suppressed.

In the first embodiment, the area of the end surface 112b of the piston 112 on the advance hydraulic chamber 120 side is set to be larger than the area of the end surface 12b of the piston 12 on the retard hydraulic chamber 20 side. The gear specifications of the valve timing adjustment device for the valve may be set so that the thrust force is smaller than the gear specifications of the valve timing adjustment device for the intake valve. In this case, the arc gear of the valve timing adjusting device for the exhaust valve may have a smaller twist angle or a larger pitch circle than the arc gear of the valve timing adjusting device for the intake valve. (Second Embodiment) FIGS. 3 to 6 show a second embodiment of the present invention. As shown in FIGS. 3 to 6, the valve timing adjusting device of the second embodiment includes a vane type intake valve timing adjusting device 300 and a vane type exhaust valve timing adjusting device 400.

First, the intake valve timing adjusting device 300 will be described with reference to FIGS. The timing pulley 208 shown in FIG. 3 receives a driving force transmitted from a crankshaft as a drive shaft of an engine (not shown) by a timing belt (not shown), and rotates in synchronization with the crankshaft. The rear member 250 is a plate 25
1 and a bearing portion 252, and the plate portion 251, the timing pulley 208, and a shoe housing 207 described later are connected by bolts 253. The camshaft 201 as a first driven shaft is a timing pulley 2
A driving force is transmitted from the switch 08 to open and close an intake valve (not shown). The camshaft 201 is supported by a cylinder head (not shown) via a journal portion 202, and is rotatable relative to the timing pulley 208 with a predetermined phase difference. The timing pulley 208 and the camshaft 201 rotate clockwise as viewed from the left in FIG. Hereinafter, this rotation direction is referred to as an advance direction.

The shoe housing 207 has a peripheral wall 271 and a front portion 272 integrally formed. Both end surfaces of the vane rotor 204 in the axial direction are the front part 272 of the shoe housing 207 and the plate part 25 of the rear member 250.
Covered by 1. The timing pulley 208, the shoe housing 207, and the rear member 250 form a first driving-side rotating body, and are coaxially connected to each other by bolts 253.

As shown in FIG. 5, the shoe housing 20
7 is a shoe 2 formed in a trapezoidal shape at substantially equal intervals in the circumferential direction.
07a, 207b, and 207c. Shoe 20
Fan-shaped spaces 255 for accommodating the vanes 204a, 204b, 204c are formed in three circumferential gaps of 7a, 207b, 207c, respectively.
The inner peripheral surfaces of a, 207b, and 207c are formed in an arc-shaped cross section.

The vane rotor 204 has vanes 204a, 204b, 204c at substantially equal intervals in the circumferential direction, and the vanes 204a, 204b, 204c are connected to the shoes 207a,
It is rotatably accommodated in a fan-shaped space portion 255 formed in a circumferential gap between 207b and 207c. Arrows indicating the retard direction and the advance direction shown in FIG. 5 indicate the retard direction and the advance direction of the vane rotor 204 with respect to the shoe housing 207. In FIG. 5, each vane is located at one circumferential end of each fan-shaped space portion 255 and the vane rotor 2
04 is at the most retarded position with respect to the shoe housing 207. The most retarded position is defined by the retard side surface of the vane 204b being locked to the advance side surface of the shoe 207a. As shown in FIG. 3, the vane rotor 204 and the bush 206 are integrally connected to the camshaft 201 by bolts 205, and constitute a first driven side rotating body. Here, assuming that the axial length of the vane rotor 204 is Lin, if the axial cross-sectional shape of the vane is the same, the pressure receiving area where the operating oil pressure acts on the vanes 204a, 204b, 204c is determined by Lin. Vane 204
The pressure receiving surface on which the operating oil pressure acts on a, 204b, and 204c corresponds to the first pressure receiving surface described in the claims. Shoe housing 20 bearing bush 206
7 is covered with a cover 258, and the cover 258 is fixed to the shoe housing 207 with bolts 259. The hole 232 provided in the bolt 205 is for returning hydraulic oil leaked from the circumferential end of the vane rotor 204 to the cylinder head.

Camshaft 201 and bush 206
Are fitted to the bearing part 252 of the rear member 250 and the inner peripheral wall 272a of the front part 272 so as to be relatively rotatable. Therefore, the camshaft 201 and the vane rotor 204 can rotate relative to the timing pulley 208 and the shoe housing 207 coaxially. FIG.
As shown in FIG.
Is fitted to the outer peripheral wall of A minute clearance is provided between the outer peripheral wall of the vane rotor 204 and the inner peripheral wall of the shoe housing 207, and the seal member 209 prevents the hydraulic oil from leaking between the hydraulic chambers through the clearance. Each of the sealing members 209 is a leaf spring 2
It is pushed toward the inner peripheral wall of the peripheral wall 271 by the urging force of 10.

As shown in FIG. 3, the guide ring 291 is press-fitted and held on the inner wall of the vane 204a, and the stopper piston 217 is inserted into the guide ring 291.
The stopper piston 217 is formed in a bottomed cylindrical shape having substantially the same outer diameter, and is accommodated in the guide ring 291 so as to be slidable in the axial direction of the camshaft 201. The stopper piston 217 is moved by the spring 216 to the front part 27.
It is biased to two sides. The fitting ring 254 is fitted in a fitting hole formed in the front portion 272, and the fitting ring 2
A tapered hole 254a is formed in the inner peripheral wall of the. The stopper piston 217 can be fitted into the tapered hole 254a at the most retarded position shown in FIG. When the stopper piston 217 is fitted in the tapered hole 254a, and the stopper piston 217 is in contact with the tapered hole 254a in the rotation direction, the vane rotor 204 with respect to the shoe housing 207.
Relative rotation is restricted. That is, the stopper piston 2
17 and the tapered hole 254a are in the restrained position at the most retarded position. Stopper piston 217, tapered hole 254a
The spring 216 and the spring 216 constitute a lock mechanism.

The hydraulic chamber 218 on the left side of the flange portion 217b
Communicates with an advance hydraulic chamber 285 described later via an oil passage 240 shown in FIG. The hydraulic chamber 227 formed on the distal end side of the cylindrical portion 217a communicates with a retard hydraulic chamber 280 described later via an oil passage (not shown). Hydraulic chamber 22
7, the pressure receiving surface of the cylindrical portion 217a receiving the hydraulic pressure, and the hydraulic chamber 2
The force that the pressure receiving surface of the flange portion 217b receiving the hydraulic pressure of 18 receives from the hydraulic oil in the hydraulic chamber 227 and the hydraulic chamber 218 acts in a direction to pull out the stopper piston 217 from the tapered hole 254a. When hydraulic oil having a predetermined pressure or more is supplied to the retard hydraulic chamber 280 or the advance hydraulic chamber 285, the stopper piston 217 comes out of the tapered hole 254a against the urging force of the spring 216 due to the hydraulic pressure of the hydraulic oil.

The position of the stopper piston 217 and the position of the tapered hole 254a are determined when the vane rotor 204 is at the most retarded position with respect to the shoe housing 207, that is, the camshaft 201 is at the most retarded position with respect to the crankshaft. Sometimes, the stopper piston 217 is set at a position where it can be fitted into the tapered hole 254a by the urging force of the spring 216.

A communication passage 2 communicating with the back pressure chamber 230 of the stopper piston 217 is provided on the rear member 250 side of the vane 204a.
29 are formed. The communication passage 229 communicates with the communication passage 228 formed in the bearing portion 252 at the most retarded position.
Since the communication passage 228 is open to the atmosphere in an oil lubrication space (not shown) of the engine, the back pressure chamber 230 is located at the most retarded position.
Is open to the atmosphere. Therefore, the movement of the stopper piston 217 is not hindered at the most retarded position. When the vane rotor 204 rotates from the most retarded position to the advanced side, that is, when the vane rotor 204 is rotated to a non-constrained position where the stopper piston 217 and the tapered hole 254a cannot be fitted, the communication between the communication passage 229 and the communication passage 228 is stopped. Will be shut off.

As shown in FIG. 5, a retard hydraulic chamber 280 is formed between the shoe 207a and the vane 204a, and a retard hydraulic chamber 281 is formed between the shoe 207b and the vane 204b.
Is formed, and a retard hydraulic chamber 282 is formed between the shoe 207c and the vane 204c. In addition, shoe 20
An advanced hydraulic chamber 283 is formed between the shoe 7a and the vane 204b, and an advanced hydraulic chamber 284 is formed between the shoe 207b and the vane 204c.
a advanced hydraulic chamber 285 is formed.

As shown in FIG. 3, the boss portion 204d of the vane rotor 204 is provided with an oil passage 213 formed in an arc shape at a contact portion with the bush 206. The oil passage 213 communicates with a hydraulic pump or a drain (not shown) as driving means via an oil passage 212 and a circumferential groove 211. The hydraulic pump also serves as a drive source for engine lubrication oil.

Further, as shown in FIG. 5, the oil passage 213 is connected to the advance hydraulic chamber 283 through oil passages 256, 257 and 258.
284, 285. The hydraulic chamber 218 communicates with the advance hydraulic chamber 285 via an oil passage 240.
Next, the exhaust valve timing adjusting device 400 will be described with reference to FIGS. Components substantially the same as those of the intake valve timing adjustment device 300 are denoted by the same reference numerals.

The timing pulley 308 shown in FIG. 3 receives a driving force from a crankshaft (not shown) as a drive shaft of an engine by a timing belt (not shown), and rotates in synchronization with the crankshaft. Rear member 3
50 comprises a plate portion 351 and a bearing portion 352,
The plate 351, the timing pulley 308, and a shoe housing 307 described later are connected by bolts 253. Camshaft 301 as second driven shaft
The driving force is transmitted from the timing pulley 308 to open / close an exhaust valve (not shown). Camshaft 301
Is supported by a cylinder head (not shown) via a journal portion 302 and is rotatable relative to the timing pulley 308 with a predetermined phase difference. The timing pulley 308 and the camshaft 301 rotate counterclockwise as viewed from the left in FIG. Hereinafter, this rotation direction is referred to as a retard direction.

The shoe housing 307 has a peripheral wall 371 and a front portion 372 integrally formed. Both end surfaces in the axial direction of the vane rotor 304 are connected to the front portion 372 of the shoe housing 307 and the plate portion 35 of the rear member 350.
Covered by 1. The timing pulley 308, the shoe housing 307, and the rear member 350 constitute a second driving-side rotating body, and are coaxially connected to each other by bolts 253.

As shown in FIG. 6, the shoe housing 30
7 is a shoe 3 formed in a trapezoidal shape at substantially equal intervals in the circumferential direction.
07a, 307b, and 307c. Shoe 30
Fan-shaped spaces 355 for accommodating the vanes 304a, 304b, 304c are formed in three circumferential gaps of the shoes 7a, 307b, 307c, respectively.
The inner peripheral surfaces of a, 307b, and 307c are formed in an arc-shaped cross section.

The vane rotor 304 has vanes 304a, 304b, 304c at substantially equal intervals in the circumferential direction, and the vanes 304a, 304b, 304c are connected to the shoes 307a,
It is rotatably accommodated in a fan-shaped space 355 formed in a circumferential gap between 307b and 307c. Arrows indicating the retard direction and the advance direction shown in FIG. 6 indicate the retard direction and the advance direction of the vane rotor 304 with respect to the shoe housing 307. In FIG. 6, each vane is located at one circumferential end of each fan-shaped space 355, and the vane rotor 3
04 is at the most advanced position with respect to the shoe housing 307. The most advanced position is defined by the advance side surface of the vane 304b being locked to the retard side surface of the shoe 307b. As shown in FIG. 4, the vane rotor 304 and the bush 306 are integrally connected to the camshaft 301 by bolts 205, and constitute a second driven-side rotating body. Here, assuming that the axial length of the vane rotor 304 is Lex, when the axial cross-sectional shapes of the vanes are the same, the pressure receiving area where the hydraulic pressure acts on the vanes 304a, 304b, 304c is determined by Lex, and Lex> Lin. Is set. Therefore, the vanes 304a, 304
The pressure receiving area where the operating oil pressure acts on b and 304c is set larger than the pressure receiving area where the operating oil pressure acts on the vanes 204a, 204b and 204c. Vane 304a,
The pressure receiving surface on which the operating oil pressure acts on 304b and 304c corresponds to the second pressure receiving surface described in the claims. The shoe housing 307 bearing the bush 306 is covered with a cover 258 on the side opposite to the timing pulley.
The cover 258 is fixed to the shoe housing 3 by bolts 259.
07.

Camshaft 301 and bush 306
Are fitted to the bearing part 352 of the rear member 350 and the inner peripheral wall 372a of the front part 372 so as to be relatively rotatable. Accordingly, the camshaft 301 and the vane rotor 304 can rotate relative to the timing pulley 308 and the shoe housing 307 coaxially. The stopper piston 217 can be fitted into the tapered hole 254a at the most advanced position shown in FIG. Stopper piston 2
17 fits into the tapered hole 254a, and the stopper piston 2
In a state where the roller 17 is in contact with the tapered hole 254a in the rotation direction, the relative rotation of the vane rotor 304 with respect to the shoe housing 307 is restricted. That is, the stopper piston 21
7 and the tapered hole 254a are in the restrained position at the most advanced position.

The position of the stopper piston 217 and the position of the tapered hole 254a are determined when the vane rotor 304 is at the most advanced position with respect to the shoe housing 307, that is, the camshaft 301 is at the most advanced position with respect to the crankshaft. Sometimes, the stopper piston 217 is set at a position where it can be fitted into the tapered hole 254a by the urging force of the spring 216.

The communication passage 229 communicates with the communication passage 328 formed in the bearing 352 at the most advanced position. Communication passage 32
8 is open to the atmosphere in the oil lubrication space of the engine (not shown), so that the back pressure chamber 230 is open to the atmosphere at the most advanced position. Therefore, the movement of the stopper piston 217 is not hindered at the most advanced position. Vane rotor 3
04 rotates from the most advanced position to the retarded side, that is, when the vane rotor 304 rotates to a non-constrained position where the stopper piston 217 and the tapered hole 254a cannot be fitted, the communication path 3
Communication between the communication path 29 and the communication path 328 is cut off.

Next, the operation of the valve timing adjusting device will be described. (1) When the engine is stopped (1-1) Intake valve timing adjustment device 300 When the engine is stopped, the advanced hydraulic chambers 283, 284, and 2
85 is released to the drain side, and each of the retard hydraulic chambers 280, 28
A hydraulic control valve (not shown) is switch-controlled so that the operating oil pressure is maintained at 1 and 282. Then
The vane rotor 204 moves to the most retarded position with respect to the shoe housing 207, and the front portion 272 of the rear member 250 and the vane rotor 204 are connected by the lock mechanism.
01 is held at the most retarded position.

(1-2) Exhaust Valve Timing Adjustment Device 4
00 When the engine stops, the retard hydraulic chambers 280, 281, 2
82 is released to the drain side, and each advanced hydraulic chamber 283, 28
4, 285, a hydraulic control valve (not shown) is switch-controlled so that the operating hydraulic pressure is maintained. Then
The vane rotor 304 moves to the most advanced position with respect to the shoe housing 307, and the front portion 372 of the rear member 350 and the vane rotor 304 are coupled by the lock mechanism.
01 is held at the most advanced position.

(1-3) In the second embodiment, the most retarded state of the camshaft 201 shown in FIG. 3 and FIG.
In the most advanced state of the camshaft 301 shown in FIG. 2, the opening periods of the exhaust valve and the intake valve are designed not to overlap, so that the amount of combustion gas remaining in the cylinder of the engine, that is, the so-called internal EGR amount can be reduced. , The engine starts normally.

(2) During Engine Operation (2-1) Intake Valve Timing Adjustment Device 300 The front portion 272 and the vane rotor 204 are operated by the lock mechanism until the operating oil pressure applied to each oil passage and each oil pressure chamber becomes larger than a predetermined pressure. The camshaft 201 is at the most retarded position with respect to the timing pulley 208 because the camshaft 201 is held in a coupled state.

When hydraulic oil having a hydraulic pressure greater than a predetermined pressure is introduced into each oil passage and each hydraulic chamber, the connection between the front portion 272 and the vane rotor 204 by the lock mechanism is released. Therefore, the retard hydraulic chambers 280, 281, 28
2. The operating oil pressure applied to the advance hydraulic chambers 283, 284, 285 causes the vane rotor 204 to rotate relative to the shoe housing 207, and adjusts the relative phase difference of the cam shaft 201 with respect to the timing pulley 208.

(2-2) Exhaust Valve Timing Adjustment Device 4
Until the operating oil pressure applied to each oil passage and each hydraulic chamber becomes larger than a predetermined pressure, the front portion 372 and the vane rotor 304 are held in a coupled state by the lock mechanism. The shaft 301 is at the most advanced position.

When hydraulic oil having a hydraulic pressure greater than a predetermined pressure is introduced into each oil passage and each hydraulic chamber, the connection between the front portion 372 and the vane rotor 304 by the lock mechanism is released. Therefore, the retard hydraulic chambers 280, 281, 28
2. The operating oil pressure applied to the advance hydraulic chambers 283, 284, 285 causes the vane rotor 304 to relatively rotate with respect to the shoe housing 307, and adjusts the relative phase difference of the cam shaft 301 with respect to the timing pulley 308.

(2-3) Since the opening period of the exhaust valve can be prevented from overlapping with the opening period of the intake valve when the engine is started, the internal EGR amount can be reduced. Therefore, the startability of the engine is improved, and the unburned fuel is prevented from being discharged into the exhaust gas, so that the purification effect of the exhaust gas is improved. In the second embodiment described above, when starting the engine, the camshaft 201 is held at the most retarded position with respect to the crankshaft, and the camshaft 301 is held at the most advanced position with respect to the crankshaft. Starts reliably and shifts to the normal operation state.

Further, the vanes 304a, 304b, 30
The pressure receiving area on which the operating oil pressure acts on the vane 4c
a, 204b, and 204c are set to be larger than the pressure receiving area where the operating oil pressure acts. Therefore, for the same camshaft driving torque, the operating force for rotating the vane rotor 304 in the advance direction is greater than the operating force for rotating the vane rotor 204 in the advance direction, so that the camshaft 201 The camshaft 301 can move in the advancing direction with respect to the crankshaft even if the hydraulic pressure cannot move in the advancing direction. Therefore, even when the discharge flow rate of the hydraulic pump is low, such as when the engine is running at a low speed, it is possible to control the basic phase in which the exhaust valve closes early and the intake valve opens late, preventing engine misfiring and combustion instability. can do.

Further, as in the case where the engine load shifts from a low-speed medium load to a full load, for example, as shown in FIG.
When it is necessary to move both the camshaft 301 and the camshaft 301 in the advance direction with respect to the crankshaft, the operating oil flows into the exhaust valve timing adjusting device 400 having a lower operating oil pressure than the intake valve timing adjusting device 300. Thus, the operation of the exhaust valve timing adjusting device 400 can be preferentially performed.

In the above-described embodiments of the present invention, the first driving-side rotating body and the first driven-side rotating body are connected at the most retarded position by the lock mechanism, and the second driving-side rotating body is rotated. The body and the second driven-side rotating body are connected at the most advanced position so that the opening periods of the intake valve and the exhaust valve do not overlap, but within the range where the engine can be started normally and shifted to the operating state. If so, the opening periods of the intake valve and the exhaust valve may overlap.

Further, all of the above embodiments have been described as including a lock mechanism, but it is also possible to adopt a configuration without a lock mechanism. Further, in the above-mentioned plural embodiments, the timing pulley is used as the first and second driving-side rotating bodies, but a chain sprocket can be used instead of the timing pulley.

[Brief description of the drawings]

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

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

FIG. 3 is a longitudinal sectional view showing a valve timing adjusting device for an intake valve according to a second embodiment of the present invention.

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

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

FIG. 6 is a sectional view taken along line VI-VI of FIG. 4;

[Explanation of symbols]

Reference Signs List 1 camshaft (first driven shaft) 4 camshaft sleeve (first driven rotating body) 4a external helical spline 5 timing pulley (first driven rotating body) 8 flange member (first driven rotating body) Body) 10, 11 Arc gear (first gear) 10a, 11a Internal helical spline 10b, 11b External helical spline 12 Piston (first driving force transmitting means) 13 Retainer ring (first driving force transmitting means) 14 pin (first driving force transmitting means) 19 advance hydraulic chamber 20 retard hydraulic chamber 32 sprocket sleeve (first driving-side rotating body) 32a internal helical spline 101 camshaft (second driven shaft) 104 Camshaft sleeve (second driven side rotating body) 104a External helical spline 105 Timing pulley (second driven side rotation) Roller) 108 Flange member (second drive-side rotating body) 110, 111 Arc-shaped gear (second gear) 110a, 111a Internal helical spline 110b, 111b External helical spline 112 Piston (second driving force transmission) Means) 113 Retainer ring (second driving force transmitting means) 114 Pin (second driving force transmitting means) 119 Retard hydraulic chamber 120 Advance hydraulic chamber 132 Sprocket sleeve (second driving side rotating body) 132a Internal teeth Helical spline

Claims (5)

[Claims] A first driving-side rotating body that transmits driving force of a driving shaft to a first driven shaft that opens and closes an intake valve of an internal combustion engine, and that rotates together with the driving shaft; and the first driven shaft. A first driving force transmitting unit having a first driven rotating body that rotates, and a driving force of a driving shaft transmitted to a second driven shaft that opens and closes an exhaust valve of the internal combustion engine, and rotates together with the driving shaft. A second driving force transmitting device having a second driving-side rotating member and a second driven-side rotating member rotating together with the second driven shaft, and having a larger operating force than the first driving force transmitting means; Means for relatively rotating the drive shaft and the first and second driven shafts by the first and second driving force transmitting means,
A valve timing adjusting device for an internal combustion engine, wherein the opening and closing timing of the intake valve and the exhaust valve is adjusted. 2. The first driving force transmitting means includes: a first pressure receiving surface that relatively rotates the first driving-side rotator and the first driven-side rotator when a fluid pressure is applied. The second driving force transmitting means includes a second pressure receiving surface that relatively rotates the second driving-side rotating body and the second driven-side rotating body when a fluid pressure acts. The valve timing adjusting device for an internal combustion engine according to claim 1, wherein the first pressure receiving surface has a smaller pressure receiving area than the second pressure receiving surface. 3. The first driven-side rotator is relatively rotated in an advancing direction with respect to the first drive-side rotator by a fluid pressure acting on the first pressure-receiving surface. The second driven-side rotator rotates relative to the second drive-side rotator in a retarded direction when fluid pressure acts on the second pressure-receiving surface. A valve timing adjusting device for an internal combustion engine according to the above. 4. The first driving force transmitting means includes:
A first gear that couples the driving-side rotator and the first driven-side rotator with a helical spline, wherein the second driving force transmitting means includes a second driving-side rotator and the second driving-side rotator. And a second gear that couples the second driven gear with a helical spline, wherein a gear specification of the second gear has a smaller thrust force than a gear specification of the first gear. 4. The valve timing adjusting device for an internal combustion engine according to claim 1, 2 or 3. 5. The valve timing adjusting device for an internal combustion engine according to claim 4, wherein the second gear has a smaller torsion angle or a larger pitch circle diameter than the first gear.