JPH1068306A - Valve timing regulating device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve startability of an engine through simple constitution. SOLUTION: Since arcuate gears 10 and 11 and a piston 12 are energized to the angle of advance side through the energizing force of a spring 21, a cam shaft 1 is energized to the angle of advance side based on a timing pulley 5 through a cam shaft sleeve 4. A stopper 30 is radially displaceablly contained in a containing hole 1e, and when the cam shaft 1 is situated in an angle of most advanced position based on the timing pulley 5, the shaft is fitted in a topper hole 8d. Since, during the starting of an engine, the cam shaft 1 is held in an angle of most advanced position based on a crank shaft, an engine is reliably started and transfer to a normal operation state is effected. This constitution improves startability of an engine and not discharge unburnt fuel in exhaust gas, whereby the control effect of exhaust gas is improved.

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 exhaust valve.

[0002]

2. Description of the Related Art Conventionally, a valve timing adjusting apparatus for adjusting the opening / closing timing of an exhaust valve of an internal combustion engine (hereinafter, "internal combustion engine" is referred to as an engine) (hereinafter, "opening / closing timing" is referred to as valve timing) is used to drive the engine. The driving torque is transmitted from the crankshaft as the shaft to the camshaft as the driven shaft via the 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.
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 exhaust valve is adjusted according to the operating conditions of the engine.

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

[0005]

However, in the above-mentioned conventional valve timing adjusting device, the driving torque applied to the camshaft for driving the opening and closing of the exhaust valve is reduced.
The camshaft as the driven shaft receives a force on the retard side with respect to the drive shaft. Therefore, the opening timing of the exhaust valve may be delayed when the hydraulic pressure is not operating, such as when the engine is started, and when the hydraulic pressure is low, such as when the engine is idle, so that the opening period of the exhaust valve and the opening period of the intake valve may overlap. If the opening periods of the exhaust valve and the intake valve overlap, the amount of combustion gas remaining in the cylinder of the engine, that is, the so-called internal EGR amount becomes excessive, so that the startability of the engine is deteriorated and the engine may not be able to start. Further, there is a problem that unburned fuel is discharged into exhaust gas.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an engine valve timing adjusting device which has a simple structure and improves the engine startability.

[0007]

According to the valve timing adjusting device for an engine according to the first aspect of the present invention, the driven shaft is urged in a direction advancing with respect to the drive shaft.
At the time of starting the engine, the period during 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, so that the startability of the engine is improved. Further, it is possible to reduce the amount of the fuel sucked from the intake valve and discharged from the exhaust valve as unburned fuel.

According to the second aspect of the present invention, since the urging force of the first urging means is larger than the maximum torque at the time of starting the engine, the magnitude of the driving torque received by the driving shaft is increased. Regardless, the relative rotational phase difference between the drive shaft and the driven shaft can be stably maintained. Therefore, it is possible to prevent the generation of the collision sound between the members in the driving force transmitting means at the time of starting the engine.

According to the valve timing adjusting device for an engine according to the third or fifth aspect of the present invention, at the time of starting the engine, the lock mechanism can couple the driving side rotating body and the driven side rotating body. The relative rotational phase difference between the motor and the driven-side rotator can be stably held. Therefore, it is possible to prevent the generation of the collision sound between the members in the driving force transmitting means at the time of starting the engine.

According to the valve timing adjusting device for an engine according to the fourth aspect of the present invention, the exhaust valve and the intake valve overlap because the driving-side rotating body can be fixed at the most advanced position when the engine is started. And the period for opening the valve can be reduced. Therefore, the startability of the engine is improved, and the amount of unburned fuel discharged into the exhaust gas can be reduced.

According to the valve timing adjusting device for an engine of the present invention, when starting the engine in which the hydraulic oil of a predetermined pressure or more is not introduced, the driving side rotating body and the driven side rotating body are connected by the lock mechanism. Therefore, at the time of starting the engine, the generation of the collision sound between the members in the driving force transmitting means can be reliably prevented. When the operating oil pressure becomes larger than the predetermined pressure, the connection between the driving-side rotating body and the driven-side rotating body is released, so that the relative rotational phase difference between the driving shaft and the driven shaft can be adjusted by the driving force transmitting means.

According to the valve timing adjusting device for an engine of the present invention, even if the driven shaft receives a driving torque due to the driving of the exhaust valve, a force is applied in a direction in which the helical splines come into contact with each other. The generation of spline rattle can be suppressed. Further, since the urging force for urging the gear gear in the opposite direction urges the driven-side rotating body in the advance direction, the urging force of the first urging means can be reduced.

According to the valve timing adjusting device for an engine of the present invention, the gear gear is urged in a direction in which the driven shaft advances with respect to the driving shaft and the urging force with the first urging means. Since the sum with the urging force is larger than the maximum torque at the time of starting the engine, the relative rotational phase difference between the drive shaft and the driven shaft can be stably maintained regardless of the magnitude of the drive torque received by the drive shaft. Therefore, it is possible to prevent the generation of the collision sound between the members in the driving force transmitting means at the time of starting the engine.

According to the valve timing adjusting device for an engine of the ninth aspect of the present invention, the urging force for urging the gear gear in the direction in which the driven shaft is retarded with respect to the drive shaft is such that the driven shaft advances with respect to the drive shaft. The frictional force acting between the helical splines of the gear gears on the retard side is reduced when the driven shaft is rotated relatively to the advance side with respect to the drive shaft because it is smaller than the biasing force for biasing the gear gears in the angular direction. it can. Therefore, the driven shaft can be smoothly rotated relative to the drive shaft toward the advanced side.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment showing an embodiment of the present invention will be described with reference to the drawings. The valve timing adjusting devices of the first to seventh embodiments described below adjust the valve timing of the exhaust valve. (First Embodiment) FIGS. 1, 2 and 3 show an engine valve timing adjusting apparatus according to a first embodiment of the present invention. In FIG. 1, a rotational torque is transmitted from a crankshaft (not shown) as a drive shaft to a timing pulley 5 which is a driving-side rotating body by a timing belt (not shown).

A cylindrical camshaft sleeve 4 is fixed to one end of the camshaft 1 by bolts 2 and pins (not shown) so as to rotate integrally with the camshaft 1 as a driven shaft. External teeth helical splines 4a are formed on a part of the outer peripheral wall of the camshaft sleeve 4 as the 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 7 and the flange member 8 together with the timing pulley 5 constitute a drive-side rotating body, and an annular portion 7a and an annular portion 8a are assembled to the timing pulley 5 by bolts 6. Flange member 8
The annular portion 8a and the cylindrical portion 8b are integrally formed. Since the inner side surface 8c of the cylindrical portion 8b is supported by the outer peripheral wall 1a of the camshaft 1, the timing pulley 5
Are rotatably supported by the camshaft 1.

The cylindrical member 9 is fixed to the inner cylinder 7b of the sprocket sleeve 7 by welding or the like, and an internal tooth helical spline 9a is formed on the inner peripheral wall of the cylindrical member 9. Between the camshaft sleeve 4 and the cylindrical member 9 in the radial direction, two arc-shaped gears 10 and 11 for relatively rotating the timing pulley 5 and the camshaft 1 are interposed. Arc gears 10 and 11 as driving force transmitting means
Is formed by dividing one ring-shaped gear by a dividing surface including a shaft. When the arc gear 10 and the arc gear 11 move to the advance side shown by the arrow in FIG. 1, the camshaft 1 advances with respect to the timing pulley 5, and when it moves to the retard side shown by the arrow, the camshaft 1 The timing pulley 5 is retarded. The arc gears 10 and 11 are alternately attached to the piston 12 in the circumferential direction, and apparently constitute one ring gear. Arc-shaped grooves 10c, 11c are formed at the upper ends of the arc-shaped gears 10, 11, respectively.
The retainer ring 13 is accommodated in 0c 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.

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. In addition, since the pin 14 is press-fitted into the retainer ring 13, the retainer ring 13 and the pin 14 move together and form a part of the driving force transmitting means. Since the pin 14 is urged to the right in FIG. 1 by the urging force of the spring 15, the retainer ring 13 and the arc gear 11 also move to the right in FIG. 1, that is, the urging direction of the arc gear 10 by the spring 18. Is urged in the direction approaching the piston 12 in the opposite direction.

Inner helical splines 10a and 11a are formed on the inner peripheral walls of the arc gears 10 and 11, respectively, and outer helical splines 10b and 11b are formed on the outer peripheral walls. The axial movement of the arc gears 10, 11 is possible within the compression range of the springs 18 and 15, respectively. Since the arc gears 10 and 11 are urged away from each other, the cylindrical member 9 and the camshaft sleeve 4
Before interposing the arc gears 10 and 11 between
The axial positions of the external tooth helical splines 10b and 11b and the internal tooth helical splines 10a and 11a are further shifted than in FIG.

When the arc gears 10, 11 are interposed between the cylindrical member 9 and the camshaft sleeve 4, the arc gears 10, 11
Numeral 11 denotes a small displacement in the axial and rotational directions of the camshaft 1 by an amount corresponding to the backlash between the splines, thereby reducing the axial displacement from the state before the interposition to reduce the cylindrical member 9 and the camshaft sleeve. 4 interposed. The springs 18 and 15 urge the arc gears 10 and 11 with respect to the piston 12 in opposite axial directions. With this urging force, the arc gear 1
0 applies a torque to the timing pulley 5 to relatively rotate the camshaft 1 in the retard direction, and the arc gear 11 applies a torque to the timing pulley 5 to relatively rotate the camshaft 1 in the advance direction. 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 9a of the cylindrical member 9 in the retard direction, and the internal helical spline 10a changes the external helical spline of the camshaft sleeve 4. 4a is pressed in the retard 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 9a of the cylindrical member 9 in the advance direction, and the internal helical spline 11a becomes the external helical spline of the camshaft sleeve 4. 4a is pressed in the advance direction. Therefore,
The arc gears 10 and 11 are provided with springs 18 and 15 respectively.
When the exhaust valve is opened and closed, a torque against the positive and negative driving torques received by the camshaft 1 when the exhaust valve is opened and closed is given, and the rattling noise due to backlash between splines can be suppressed.

The rotation of the timing pulley 5 is transmitted to the camshaft 1 through the sprocket sleeve 7, the cylindrical member 9, the arc gears 10 and 11, and the camshaft sleeve 4 by the meshing of the splines. A spring 21 serving as a first urging means is housed between the sprocket sleeve 7 and the cylindrical member 9, and shown in FIG.
The piston 12 is urged to the right, that is, the advance side. Due to the urging force of the spring 21, the arc gear 10,
1 and the piston 12 are urged to the right in FIG.
Are biased toward the advance side with respect to the timing pulley 5.

As described above, the cam shaft sleeve 4 and the cam shaft 1 are urged in the advance direction by the spring 15 pressing the arc gear 11 in the advance direction. That is, the spring 15 forms a part of the first urging means. Spring 15 and spring 2
The sum of the urging forces by which 1 urges the camshaft 1 to the advance side is
It is set to be larger than the maximum torque at the time of cranking at the time of engine start. Therefore, the urging force of the spring 21 can be reduced as compared with the case where the spring 15 is not provided.

In the above configuration, the spring 1
The urging force of 8 is set smaller than the urging force of the spring 15. Thus, when the camshaft 1 is relatively rotated in the advance direction with respect to the timing pulley 5, the frictional force in the retard direction acting between the helical splines due to the urging force of the spring 18 can be reduced. The relative rotation can be smoothly performed in the advance angle direction.

The stopper 30 is formed in a cylindrical shape with a bottom and is accommodated in an accommodation hole 1e opened in the outer peripheral wall of the camshaft 1 so as to be displaceable in the radial direction. The stopper 30 is the second
Are urged radially outward by a spring 31 as an urging means. The stopper hole 8d is formed in the inner peripheral wall of the cylindrical portion 8b of the flange member 8, so that the stopper 30 can be fitted into the stopper hole 8d when the camshaft 1 is at the most advanced position with respect to the timing pulley 5. Become. FIG.
Shows a state in which the stopper 30 is fitted in the stopper hole 8d. The stopper hole 8d communicates with the annular oil passage 1f, and the oil passage 1f communicates with the oil passage 1d. Oilway 1
Since f communicates with the retard hydraulic chamber 20 via an oil passage (not shown), the fitting hole 8 d communicates with the retard hydraulic chamber 20. The communication path 1g is open to the atmosphere so as not to hinder the movement of the stopper 30.

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 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. Advance hydraulic chamber 19
The retard hydraulic chamber 20 is separated from the retard hydraulic chamber 20 by a resin seal member 40 fitted on the outer periphery of the piston 12.

By controlling the switching of a hydraulic control valve (not shown), the flow of the supply of the pressure oil to the oil passage communicating with the advance hydraulic chamber 19 and the retard hydraulic chamber 20 and the discharge of the pressure oil from the oil passage are controlled. Controlled. Specifically, an oil passage 4b formed in the camshaft sleeve 4 communicating with the advance hydraulic chamber 19, the bolt 2
The hydraulic passage 2a and the oil passages 1c and 1b formed in the camshaft 1 and the oil pump side or the drain side are electrically connected or disconnected by switching control of a hydraulic control valve, and the advanced hydraulic chamber 19 To control the hydraulic pressure inside. 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 arc gears 10 and 11 and the piston 12 are moved or stopped in the axial direction by the hydraulic pressure balance between the advance hydraulic chamber 19 and the retard hydraulic chamber 20, and the relative phase difference of the camshaft 1 with respect to the timing pulley 5 is controlled. be able to.

Next, the operation of the valve timing adjusting device will be described. 1. When the engine stops normally (1-1) When the engine stops normally, the oil passages 4d, 2a, 1c, and 1b communicating with the advance hydraulic chamber 19 are maintained in a state where the operating hydraulic pressure is applied, and communicate with the retard hydraulic chamber 20. Oil passage 1d
The hydraulic control valve is switch-controlled so that is released to the drain side. Therefore, the arc gear 1 together with the piston 12
0 and 11 move to the right in FIG. 1, and the camshaft 1 stops at the most advanced position with respect to the timing pulley 5 as shown in FIGS. At this time, the fitting hole 8
Since d is also released to the drain side, the stopper 30 is fitted into the stopper hole 8d by the urging force of the spring 31. Then, the camshaft 1 and the flange member 8 are connected by the stopper 30, and the camshaft 1 as the driven shaft is reliably held at the most advanced position with respect to the crankshaft as the drive shaft.

(1-2) In the first embodiment, since the valve opening periods of the exhaust valve and the intake valve are designed not to overlap in the most advanced state shown in FIG. 2, the valve remains in the cylinder of the engine. The amount of combustion gas, which is so-called internal EGR, can be reduced, and the engine starts normally. Even if the engine is started, the spring 31 is used until hydraulic oil is introduced into each oil passage and each hydraulic chamber and the oil pressure in the oil passage 1d rises above a predetermined operating oil pressure.
The stopper 30 remains fitted in the stopper hole 8d due to the urging force.

Camshaft 1 with respect to crankshaft
Is cranked in the most advanced position and the engine starts operating normally, the oil pressure in the oil passages 1d and 1f rises to a predetermined operating oil pressure, and the spring 31 is attached by the force received from the oil pressure in the stopper hole 8d. Stopper 30 against power
Escapes from the stopper hole 8d. Thereby, the connection state between the camshaft 1 and the flange member 8 is released, so that the timing pulley 5 and the camshaft 1 can be relatively rotated. The advance hydraulic chamber 19 and the retard hydraulic chamber 20
, The arc gears 10 and 11 and the piston 12 reciprocate in the axial direction irrespective of the urging force of the spring 21, and the relative phase difference of the camshaft 1 with respect to the timing pulley 5 is adjusted.

2. When the engine stops abnormally When the engine stops abnormally, the hydraulic pressure control is interrupted halfway, but as described above, the sum of the urging forces of the springs 15 and 21 is larger than the maximum torque at the time of cranking at the time of engine start. The camshaft 1 moves to the most advanced position. Then, when the camshaft 1 moves to the most advanced position, the stopper 30 is fitted into the fitting hole 8d, and the camshaft 1 and the flange member 8 are securely connected at the most advanced position. When the engine starts normal operation, the oil pressure in the oil passages 1d and 1f rises to a predetermined operating oil pressure, and FIG.
(A) and (B), the stopper 30 comes out of the stopper hole 8d against the urging force of the spring 31 by the force received from the oil pressure in the stopper hole 8d. When the stopper 30 comes out of the stopper hole 8d, the rotation of the camshaft 1 relative to the timing pulley 5 can be controlled. FIG. 3 shows a state in which the stopper 30 comes out of the stopper hole 8 d and the camshaft 1 is at the most retarded position with respect to the timing pulley 5.

In the first embodiment described above, the camshaft 1 is held at the most advanced position with respect to the crankshaft when the engine is started, regardless of whether the engine is stopped normally or abnormally. Start and shift to normal operation. Therefore, the startability of the engine is improved, and the effect of purifying the exhaust gas is improved because the unburned fuel is not discharged into the exhaust gas.

In the first embodiment, the arc gears 10, 11
Is the piston 1 by the urging force of the springs 18 and 15.
2, the outer teeth helical splines 10b and 11b apply torques in opposite directions to the inner teeth helical splines 9a on the cylindrical member 9 side. On the camshaft sleeve 4 side, the internal gear helical splines 10a and 11a respectively abut against the external gear helical splines 4a by applying opposite torques.
For this reason, even if the torque fluctuates in the opposite direction (positive torque) or in the same direction (negative torque) as the rotational direction due to the driving torque in the rotational direction of the camshaft 1, the rattling noise due to the backlash of the helical spline. Can be suppressed.

In the first embodiment, the lock mechanism connects the flange member 8 and the camshaft 1 in the radial direction. However, the lock mechanism may be configured to connect the flange member 8 and the camshaft 1 in the axial direction. It is possible. (Second Embodiment) FIG. 4 shows a second embodiment of the present invention. First
Components that are substantially the same as those in the embodiment are denoted by the same reference numerals. In the second embodiment, each helical spline is formed in a direction opposite to that of the first embodiment.

The sprocket sleeve 32 as a driving-side rotating body is mounted on the timing pulley 5 by bolts 6 together with the flange member 8. The sprocket sleeve 32 includes an outer cylinder having a small diameter portion 32d and a large diameter portion 32e, an annular flange portion 32c extending radially outward from a side opposite to the small diameter portion of the large diameter portion 32e, an inner cylinder 32b, and a small diameter portion. An annular portion 32f extending radially inward from the opposite large-diameter portion side of 32d and connecting the outer cylinder and the inner cylinder 32b is integrally formed. Internal teeth helical splines 32a are formed on a part of the inner peripheral wall of the small diameter portion 32d. The internal tooth helical splines 32a mesh with the external tooth helical splines 10a, 11a of the arc gears 10, 11.

A spring 22 as a first urging means is housed in a conical shape between the piston 12 and the flange member 8, and urges the piston 12 to the left in FIG. I have. Spring 22 and spring 18
Is designed to be larger than the maximum torque when the engine is started. That is, the spring 18 forms a part of the first urging means. Therefore, compared to the case without the spring 18, the spring 22
Biasing force can be reduced. Further, even when the camshaft 1 is not at the most advanced position with respect to the crankshaft at the time of starting the engine, the camshaft 1 is moved to the most advanced position to shift to the normal operation, and the teeth due to the backlash between the helical splines. It is possible to prevent occurrence of a tapping sound.

In the second embodiment, the hydraulic chamber 19 is a retard hydraulic chamber 19, and the hydraulic chamber 20 is an advanced hydraulic chamber 20. Although not shown, a stopper and a spring as a lock mechanism have the same configuration as in the first embodiment, and a fitting hole in which the stopper is fitted communicates with the retard hydraulic chamber 19.

(1) When the engine stops normally, the oil passages 4d, 2a, 1c and 1b communicating with the retard hydraulic chamber 19 are released to the drain side, and the oil passages 1f and 1f communicating with the advance hydraulic chamber 20.
As for d, the hydraulic control valve is switch-controlled so that the operating hydraulic pressure is maintained. Therefore, the arc gears 10, 1
1 and the piston 12 move to the left side in FIG. 4, that is, the most advanced position. When the camshafts 1 rotate relatively to the most advanced position with the movement of the arc gears 10, 11 and the piston 12 to the most advanced position, the camshaft 1 and the flange member 8 are connected by the lock mechanism. The camshaft 1 is held at the most advanced position with respect to the timing pulley 5.

(2) Even if the engine is started, the oil passages 4d, 2d
a, 1c and 1b, the camshaft 1 is locked by the lock mechanism until the operating oil pressure rises above a predetermined pressure.
And the flange member 8 are held together. Oilway 4
When the operating oil pressure of d, 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, so that the timing pulley 5 and the camshaft 1 can be relatively rotated. become. And, by the operating hydraulic pressure applied to the retard hydraulic chamber 19 and the advance hydraulic chamber 20,
Regardless of the biasing force of the spring 22, the arc gears 10, 1
1 and the piston 12 reciprocate in the axial direction, and the relative phase difference of the camshaft 1 with respect to the timing pulley 5 is adjusted.

Even when the engine stops abnormally, the engine shifts to the normal operation state as in the first embodiment. Therefore, in the second embodiment, as in the first embodiment, 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, regardless of whether the engine is stopped normally or abnormally. Therefore, 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.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention.
Shown in Components substantially the same as those in the first embodiment are denoted by the same reference numerals. Each helical spline is formed in a direction opposite to that of the first embodiment. In the third embodiment, a small-diameter spring 25 is provided on the outer periphery of the flange member 8, and a large-diameter spring 26 having a larger diameter than the small-diameter spring 25 is provided on the outer periphery of the small-diameter spring 25. Both springs bias the piston 12 to the advanced side. The sum of the urging forces of the small-diameter spring 25, the large-diameter spring 26, and the spring 18 is designed to be larger than the maximum torque at the time of starting the engine. Therefore, the sum of the urging forces of the small-diameter spring 25 and the large-diameter spring 26 can be reduced as compared with the case where the spring 18 is not provided. Further, even when the camshaft 1 is not at the most advanced position with respect to the crankshaft at the time of starting the engine, the camshaft 1 is moved to the most advanced position to shift to the normal operation, and the teeth due to the backlash between the helical splines. It is possible to prevent occurrence of a tapping sound. Other configurations are substantially the same as those of the second embodiment. Therefore,
The hydraulic chamber 19 is a retard hydraulic chamber 19 as in the second embodiment, and the hydraulic chamber 20 is an advance hydraulic chamber 20.

Although not shown, similar to the first embodiment,
A lock mechanism capable of connecting the flange member 8 and the camshaft 1 is provided. In the third embodiment, the number of springs as the first urging means is reduced to two, so that the urging force of each spring can be reduced. If design is possible, the number of springs can be three or more.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment of the present invention.
Shown in Components substantially the same as those in the first embodiment are denoted by the same reference numerals. Each helical spline is formed in the same twist direction as in the first embodiment. The sprocket sleeve 41 and the flange member 8 as the driving side rotating body are
To the timing pulley 5. An internal tooth helical spline 41a is formed on the inner peripheral wall of the sprocket sleeve 41, and meshes with the external tooth helical splines 10b and 11b of the arc gears 10 and 11.

The camshaft sleeve 50 is fixed to one end of the camshaft 1 by bolts 2 and pins 42. The camshaft sleeve 50 includes an inner race 51 and an outer race 52, and an outer tooth helical spline 52 a is formed on an outer peripheral wall of the outer race 52. The external tooth helical spline 52a meshes with the internal tooth helical splines 10a, 11a of the arc gears 10, 11. Inner ring 51
And communication holes 51b, 52 formed in the outer ring 52, respectively.
The oil passage 2a communicates with the advance hydraulic chamber 19 by b.

Spring 27 as first urging means
Is housed between the inner ring 51 and the outer ring 52, and the piston 1
2 is urged to the advance side. The sum of the urging forces of the spring 27 and the spring 15 is designed to be larger than the maximum torque at the time of starting the engine. Therefore,
The urging force of the spring 27 can be reduced as compared with the case where the spring 15 is not provided. Further, even when the camshaft 1 is not at the most advanced position with respect to the crankshaft at the time of starting the engine, the camshaft 1 is moved to the most advanced position to shift to the normal operation, and the teeth due to the backlash between the helical splines. It is possible to prevent occurrence of a tapping sound.

The inclination of each helical spline is the same as in the first embodiment. That is, when the arc gears 10 and 11 move to the left in FIG.
When the arc gears 10 and 11 move rightward in FIG. 6, the camshaft 1 rotates forward with respect to the timing pulley 5. Therefore, the hydraulic chamber 19
Is the advanced hydraulic chamber 19 in the fourth embodiment, and the hydraulic chamber 20 is the retard hydraulic chamber 20 in the fourth embodiment.

Although not shown, similar to the first embodiment,
A lock mechanism capable of connecting the flange member 8 and the camshaft 1 is provided. In the first to fourth embodiments described above, the ring-shaped gear is formed by dividing the ring-shaped gear by a plane including the shaft, but the ring-shaped gear is divided by a plane perpendicular to the shaft to form each arc-shaped gear. It is also possible to form a mold gear.

(Fifth Embodiment) FIG. 7 shows a fifth embodiment of the present invention.
And FIG. The timing pulley 61 receives a driving force transmitted from a crankshaft (not shown) serving as a drive shaft of the engine by a timing belt (not shown), and rotates in synchronization with the crankshaft. The camshaft 71 as a driven shaft receives a driving force from the timing pulley 61 and drives an exhaust valve (not shown) to open and close. The camshaft 71 is rotatable with a predetermined phase difference with respect to the timing pulley 61. The timing pulley 61 and the camshaft 71 rotate clockwise as viewed from the left side in FIG. Hereinafter, this rotation direction is referred to as an advance direction.

As shown in FIG. 7, the timing pulley 61
And the shoe housing 62 are coaxially fixed by bolts 63, and the shoe housing 62 and the front plate 7 are fixed.
5 is coaxially fixed with a bolt 77. The timing pulley 61, the shoe housing 62, and the front plate 75 constitute a driving-side rotating body, and the inner peripheral wall 61a of the timing pulley 61 is fitted to the outer peripheral wall of the camshaft sleeve 72 so as to be relatively rotatable.

The cam shaft 71, the cam shaft sleeve 72, the vane rotor 73 and the cylindrical projection 74 are coaxially fixed by bolts 76. The camshaft sleeve 72, the vane rotor 73, and the cylindrical projecting member 74 form a driven-side rotating body. A spiral spring 80 as a first urging means is disposed on the outer periphery of the camshaft sleeve 72, and one end is fixed to the locking portion 61b of the timing pulley 61, and the other end is connected to the camshaft sleeve 72. Fixed. The spiral spring 80 urges the vane rotor 73 to the advancing side shown in FIG. FIG. 8 shows the shoe housing 62.
5 shows a state in which the vane rotor 73 is at the most advanced position. The biasing force of the spiral spring 80 is designed to be larger than the maximum torque at the time of starting the engine.

The shoe housing 62 has trapezoidal shoes 62a, 62b and 62c projecting radially inward. The inner peripheral surfaces of the shoes 62a, 62b, and 62c are formed in an arc-shaped cross section, and fan-shaped spaces, which are accommodation chambers for the vanes 73a, 73b, and 73c, are provided in three circumferential gaps between the shoes 62a, 62b, and 62c, respectively. A part is formed.

The vane rotor 73 has fan-shaped vanes 73a, 73b and 73c at equal intervals in the circumferential direction, and the vanes 73a, 73b and 73c are connected to the shoes 62a and 62c.
It is rotatably accommodated in a fan-shaped space formed in the circumferential gap between b and 62c. Vane rotor 73
A minute clearance is provided between an outer peripheral wall of the shoe housing 62 and an inner peripheral wall of the shoe housing 62, and the vane rotor 73 is rotatable relative to the shoe housing 62. Shoe 62
A retard hydraulic chamber 81 is formed between a and the vane 73a,
A retard hydraulic chamber 82 is formed between the shoe 62b and the vane 73b, and a retard hydraulic chamber 83 is formed between the shoe 62c and the vane 73c. Further, an advanced hydraulic chamber 84 is formed between the shoe 62a and the vane 73b,
The advanced hydraulic chamber 85 is formed between the shoe 62c and the vane 73a.
6 are formed.

Although not shown, the vane rotor 73 contains an axially displaceable stopper, and this stopper can be fitted into a stopper hole formed in the front plate 75. The stopper is fitted into the stopper hole when the camshaft 71 is at the most advanced position with respect to the crankshaft. When the stopper is fitted into the stopper hole, the front plate 75 and the vane rotor 7 are fitted.
3 are combined. Thus, the camshaft 71 is held at the most advanced position with respect to the crankshaft.

With the above configuration, the camshaft 71 and the vane rotor 73 can rotate relative to the timing pulley 61, the shoe housing 62 and the front plate 75 coaxially. Next, the operation of the valve timing adjusting device will be described. (1) When the engine stops normally, retard hydraulic chambers 81 and 8
2 and 83 are released to the drain side, and each advance hydraulic chamber 84, 8
A hydraulic control valve (not shown) is controlled to be switched to 5, 86 so that the operating hydraulic pressure is maintained. Then, the vane rotor 73 moves to the most advanced position with respect to the shoe housing 62, and the front plate 75 and the vane rotor 73 are coupled by the lock mechanism, so that the cam shaft 71 is held at the most advanced position with respect to the timing pulley 61. Is done.

(2) In the fifth 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. 8, the internal EGR amount can be reduced, and the engine Starts normally. Even when the engine is started, the front plate 75 and the vane rotor 73 are held in a coupled state by the lock mechanism until the operating oil pressure applied to each oil passage and each hydraulic chamber becomes larger than a predetermined pressure. The camshaft 71 is at the most advanced position with respect to the pulley 61.

When the engine shifts to the normal operation and the operating pressure oil whose hydraulic pressure is larger than the predetermined pressure is introduced into each oil passage and each hydraulic chamber, the connection between the front plate 75 and the vane rotor 73 by the lock mechanism is released. . Therefore, the retard hydraulic chambers 81, 82, 83 and the advance hydraulic chambers 84, 85, 8
6, the vane rotor 73 rotates relative to the shoe housing 62 regardless of the biasing force of the spiral spring 80, and the relative phase difference of the cam shaft 71 with respect to the timing pulley 61 is adjusted.

When the advance side biasing force is larger than the maximum torque at the time of engine start when the engine is abnormally stopped, the vane rotor 73 stops in a state where the vane rotor 73 is held at the most advanced side by the advance side biasing force. Even if there is no, it is possible to start normally at the time of restart, and it is possible to prevent the generation of a collision sound between the shoe and each vane. Also, when the advance side biasing force is larger than the average torque at the time of starting the engine, even when the engine stops abnormally and the hydraulic control is interrupted halfway and the camshaft 1 cannot stop at the most advanced position with respect to the crankshaft. ,
If the driven-side rotating body is displaced to the advanced side by the driving torque received by the camshaft 1, it can be normally started if it is locked by the lock mechanism and held at the most advanced position, and if it is not locked in the worst case. However, the driven rotator moves to the most advanced position while fluttering due to the driving torque received by the camshaft 1, so that the engine starts normally.

Also in the fifth embodiment, it is possible to prevent the opening period of the exhaust valve from being overlapped with the opening period of the intake valve at the time of engine start, so that 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. (Sixth Embodiment) FIGS. 9 and 10 show a sixth embodiment of the present invention.
Shown in FIG. 10 shows a state where the vane rotor 73 is at the most advanced position with respect to the shoe housing 62. Components substantially the same as those of the fifth embodiment are denoted by the same reference numerals.

Timing pulley 61, rear plate 9
1. Shoe housing 62 and front plate 75
Are coaxially fixed by bolts 92 and constitute a driving-side rotating body. Since the inner peripheral wall of the rear plate 91 is rotatably supported by the outer peripheral wall of the camshaft sleeve 72, the camshaft 71 can rotate relative to the timing pulley 61.

A torsion spring 93 as a first urging means is disposed on the outer periphery of the camshaft sleeve 72, one end of which is fixed to a locking portion 91a of the rear plate 91, and the other end of which is a camshaft. It is fixed to the sleeve 72. The torsion spring 93 is connected to the shoe housing 62.
On the other hand, the vane rotor 73 is biased to the advance side shown in FIG. The biasing force of the torsion spring 93 is designed to be larger than the maximum torque at the time of starting the engine.

Although not shown, the lock mechanism has the same structure as that of the fifth embodiment. According to the configuration of the sixth embodiment, the opening period of the exhaust valve can be prevented from overlapping with the opening period of the intake valve at the time of engine start, similarly to the fifth embodiment.
The 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.

(Seventh Embodiment) FIG. 1 shows a seventh embodiment of the present invention.
It is shown in FIG. Components substantially the same as those of the fifth embodiment are denoted by the same reference numerals. In the seventh embodiment, the shoe housing 100
The spring 101 as the first urging means for urging the vane rotor 101 to the advance side with respect to the advance hydraulic chamber 8
4, 85, 86. The biasing force of the spring 101 is designed to be larger than the maximum torque at the time of starting the engine.

A recess 100d is formed on each of the advance-side circumferential end faces of the shoes 100a, 100b, and 100c, and a recess 101d is formed on each of the retard-side circumferential end faces of the vanes 101a, 101b, and 101c. ,
Each end of each spring 102 is locked in the recesses 100d and 101d. With the configuration of the seventh embodiment, as in the fifth embodiment, 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, so that the internal EGR amount is reduced. it can. 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 each of the above-described embodiments of the present invention,
The driving mechanism and the driven rotating body are connected at the most advanced position by the lock mechanism so that the opening periods of the exhaust valve and the intake valve do not overlap, but the engine starts normally and shifts to the operating state The opening period of the exhaust valve and the opening period of the intake valve may overlap as long as it is within the allowable range, and the coupling position of the driving-side rotating body and the driven-side rotating body by the lock mechanism may be more retarded than the most advanced position good.

Further, in each of the embodiments described above, the lock mechanism is provided. However, it is also possible to adopt a structure without the lock mechanism. In particular, when the biasing force for biasing the driven-side rotating body on the advance side is set to be larger than the maximum torque at the time of starting the engine, even if the structure without the lock mechanism is used, the driven-side rotating body Flap can be prevented.

In each of the above embodiments, the sum of the urging forces for urging the camshaft to the advanced side is designed to be larger than the maximum torque at the time of starting the engine. However, the sum is larger than the average torque at the time of starting the engine. It may be designed as follows. Thus, even when the driven rotator is not at the most advanced position with respect to the driving rotator at the time of engine start, the driven rotator moves to the most advanced position while fluttering due to the driving torque received by the camshaft, Start the engine normally,
It is possible to shift to a normal operation state.

In each of the above embodiments, the timing pulley is used as the driving-side rotating body. However, 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 according to a first embodiment of the present invention.

FIG. 2A is a longitudinal sectional view of the first embodiment at the most advanced position, and FIG. 2B is a sectional view taken along line BB of FIG. 2A.

FIG. 3A is a longitudinal sectional view showing a state in which a stopper is released in the first embodiment, and FIG.
It is a B sectional view.

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 longitudinal sectional view showing a valve timing adjusting device according to a third embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing a valve timing adjusting device according to a fourth embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing a valve timing adjusting device according to a fifth embodiment of the present invention.

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a longitudinal sectional view showing a valve timing adjusting device according to a sixth embodiment of the present invention.

FIG. 10 is a sectional view taken along line XX of FIG. 9;

FIG. 11 is a cross-sectional view illustrating a valve timing adjusting apparatus according to a seventh embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 cam shaft (driven shaft) 4 cam shaft sleeve (driven side rotating body) 4a external helical spline 5 timing pulley (driving side rotating body) 7 sprocket sleeve (driving side rotating body) 8 flange member (driving side rotating body) 9 Cylindrical member (driving-side rotating body) 9a Internal gear helical spline 10, 11 Arc gear (drive power transmission means) 10a, 11a Internal gear helical spline 10b, 11b External tooth helical spline 12 Piston (drive power transmission means) 13 Retainer ring (Driving force transmitting means) 14 Pin (driving force transmitting means) 19 Retard hydraulic chamber, Advanced hydraulic chamber 20 Advanced hydraulic chamber, Retard hydraulic chamber 21, 22 Spring (first biasing means) 25 Small diameter spring ( First biasing means) 26 Large diameter spring (first biasing means) 27 Spring (first biasing means) 30 Stopper (lock mechanism) 31 Spring (lock mechanism, second biasing means) 41 Sprocket sleeve (drive-side rotating body) 50 Camshaft sleeve (driven-side rotating body) 61 Timing pulley (drive-side rotating body) 62 Shoe housing ( Drive side rotating body 71 Camshaft (driven shaft) 72 Camshaft sleeve (driven side rotating body) 73 Vane rotor (driven side rotating body) 80 Spiral spring (first biasing means) 93 Torsion spring (first biasing) Means) 102 Spring (first biasing means) 100 Shoe housing (drive side rotating body) 101 Vane rotor (driven side rotating body)

Claims (9)

[Claims] A drive shaft for transmitting a drive force of a drive shaft to a driven shaft for opening and closing an exhaust valve of an internal combustion engine; and the drive shaft and the driven shaft are relatively moved by the drive force transmission device. A valve timing adjusting device that rotates and adjusts the opening / closing timing of the exhaust valve, wherein the driving force transmitting unit includes a driving-side rotating body that rotates with the driving shaft, and a driven-side rotating body that rotates with the driven shaft. And a first urging means for urging the driven-side rotating body in a direction in which the driven shaft is advanced with respect to the drive shaft. 2. The valve timing adjusting device for an internal combustion engine according to claim 1, wherein the urging force of the first urging means is larger than a maximum torque at the time of starting the internal combustion engine. 3. A locking mechanism, wherein the urging force of the first urging means is larger than an average torque at the time of starting the internal combustion engine, and has a lock mechanism capable of coupling the driving side rotating body and the driven side rotating body. The valve timing adjusting device for an internal combustion engine according to claim 1, wherein: 4. The valve timing adjusting device for an internal combustion engine according to claim 3, wherein the lock mechanism is capable of fixing the driven-side rotator at a most advanced position when the internal combustion engine is started. 5. The lock mechanism is displaceably housed in a stopper hole formed in one of the drive-side rotator and the driven-side rotator, and in the other of the drive-side rotator and the driven-side rotator. 5. The internal combustion engine according to claim 3, further comprising: a stopper that can be fitted in the stopper hole; and a second biasing unit that biases the stopper on a side where the stopper hole is fitted. Valve timing adjustment device. 6. The stopper connects the drive-side rotator and the driven-side rotator by an urging force of the second urging means when a hydraulic pressure is not operated, and the stopper is driven when a hydraulic pressure equal to or higher than a predetermined pressure is operated. The valve timing adjusting device for an internal combustion engine according to claim 5, wherein the coupling between the side rotating body and the driven side rotating body is released. 7. The driving force transmitting means includes a gear gear divided into two or more in an axial direction or a circumferential direction and coupled to the driving-side rotating body and the driven-side rotating body by a helical spline. The valve timing adjusting device for an internal combustion engine according to any one of claims 1 to 6, wherein the valves are biased in opposite directions. 8. The driving force transmission means includes a gear gear divided into two or more in an axial direction or a circumferential direction and coupled to the driving-side rotating body and the driven-side rotating body by a helical spline. Are biased in directions opposite to each other, and the biasing force of the first biasing means is greater than the average torque at the time of starting the internal combustion engine, and the biasing force of the first biasing means is 2. The internal combustion engine according to claim 1, wherein a sum of a biasing force for biasing the gear gear in a direction in which the driven shaft advances with respect to a drive shaft is larger than a maximum torque at the time of starting the internal combustion engine. Valve timing adjustment device. 9. An urging force for urging the gear gear in directions opposite to each other, the urging force for urging the gear gear in a direction in which the driven shaft is retarded with respect to the drive shaft, 9. The valve timing adjusting device for an internal combustion engine according to claim 8, wherein the biasing force for biasing the gear gear in a direction in which the driven shaft advances is smaller.