JP2003328707A - Valve timing adjusting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing adjusting device with high operation responsiveness even when the number of revolution is low without complicating structure. <P>SOLUTION: Working oil discharged from an oil pump 3 is supplied to a continuous phase control part 10 after flow rate and pressure are controlled with an oil pressure control part 30. A storing part 40 is installed between the oil pump 3 and the oil pressure control part 30. The storing part 40 has an oil chamber 44, and the working oil is stored in a state that pressure is applied to the oil chamber 44 by the energizing force of a spring 43. Therefore, when the pressure of the working oil is lowered in a spark advance oil pressure chamber 22 and a spark advance oil passage 24, or a phase lag oil pressure chamber 23 and a phase lag oil passage 25, the working oil is replenished from the storing part 40. As a result, even when the discharge pressure of the oil pump 3 is lowered attendant on drop in the number of revolution of an engine, the operation responsiveness of the continuous phase control part 10 is enhanced. <P>COPYRIGHT: (C)2004,JPO

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 (hereinafter, the internal combustion engine is referred to as "engine") for adjusting the opening / closing timing of at least one of an intake valve and an exhaust valve.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 11-336516.
As disclosed in Japanese Patent Publication, a valve timing adjusting device using hydraulic pressure is known. Japanese Patent Laid-Open No. 11-3365
The valve timing adjusting device disclosed in Japanese Patent No. 16 continuously variably controls the valve timing phase of an intake valve or an exhaust valve driven by an engine. Such a valve timing drive device generally uses an oil pump driven by an engine as a hydraulic pressure source.

[0003]

However, when an oil pump driven by an engine is used as a hydraulic pressure source, the number of revolutions of the engine and the flow rate of working oil discharged from the oil pump are correlated. Therefore, when the engine speed is low, the flow rate of the hydraulic oil discharged from the oil pump decreases. On the other hand, as the temperature of the engine rises, the viscosity of oil decreases, so the amount of oil leaking from each part increases. As a result, when the engine speed is low and the flow rate of the hydraulic oil discharged from the oil pump is small, the hydraulic pressure of the hydraulic oil discharged from the oil pump is greatly reduced, and the responsiveness of the valve timing adjustment device is reduced. It may be difficult to drive the valve timing adjusting device.

Then, the above-mentioned Japanese Patent Laid-Open No. 11-336516.
In the valve timing adjusting device disclosed in the publication, the responsiveness of the valve timing adjusting device is improved even when the engine speed is low by restricting the swinging and vibration of the vanes. In the case of the above valve timing adjustment device, the vane is advanced even when the hydraulic oil for driving the vane is insufficient, that is, when the engine speed is low and the amount of hydraulic oil discharged from the oil pump is insufficient. It is possible to drive to the corner side. However, when the engine speed is low, which requires improvement in the operation response of the valve timing adjustment device, the hydraulic pressure of the hydraulic oil discharged from the oil pump decreases. Therefore, there is a problem that the effect of improving responsiveness is small. Further, since the hydraulic oil discharged from the oil pump at the time of starting the engine does not have the hydraulic pressure required to drive the valve timing adjusting device, the effect of improving the responsiveness cannot be sufficiently obtained at the time of starting the engine. There is a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a valve timing adjusting device which has a high operation response even when the engine speed is low without inviting a complicated structure.

[0006]

According to the valve timing adjusting device of the first aspect of the present invention, the storage means is provided between the oil pump and the hydraulic control means. The storage means stores the hydraulic oil supplied from the oil pump to the hydraulic control means while maintaining the hydraulic pressure. Therefore, for example, even when the engine speed is low and the flow rate of the oil discharged from the oil pump is insufficient, the pressure drop of the hydraulic oil is reduced by supplying the hydraulic oil from the storage means. As a result, the hydraulic pressure fluctuation of the hydraulic oil is reduced and the flow rate of the hydraulic oil is increased. Therefore, the operation response can be improved even when the engine speed is low. Further, since the hydraulic pressure fluctuation of the hydraulic oil is reduced, the hydraulic pressure control accuracy is improved and the operation can be stabilized.

According to the valve timing adjusting device of the second aspect of the present invention, the inside of the storage means is divided into the oil chamber and the storage chamber by the piston. The piston is biased by the biasing means to the side that reduces the volume of the oil chamber. Therefore, the structure of the storage means is not complicated.

According to the valve timing adjusting device of the third aspect of the present invention, the urging force of the urging means is applied to the piston by the pressure of the hydraulic oil discharged from the oil pump at the time of idling after completion of the warm-up operation of the engine. It is almost the same as force. As a result, the pressure of the hydraulic oil is maintained by the biasing means even when the temperature of the engine rises and the viscosity of the hydraulic oil decreases. Therefore, the required hydraulic pressure of the hydraulic oil is always maintained, and the operational responsiveness can be improved regardless of the operating region of the engine.

According to the valve timing adjusting device of the fourth aspect of the present invention, the check valve prevents the hydraulic fluid from flowing back from the hydraulic control means to the oil pump. for that reason,
It is possible to prevent the hydraulic pressure from decreasing due to the backflow of the discharged hydraulic oil. Therefore, the operation response can be improved.

According to the valve timing adjusting device of the fifth aspect of the present invention, the piston has the first pressure receiving surface and the second pressure receiving surface having different pressure receiving areas. Therefore, by switching the oil passage, the hydraulic pressure of the hydraulic oil discharged from the oil chamber of the storage means is increased. As a result, even when the discharge pressure of the oil pump is low, such as when the engine is started, the required hydraulic pressure and flow rate of the hydraulic oil are secured. Therefore, the operation response can be improved even when the engine is started.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plurality of embodiments showing the embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a valve timing adjusting device according to a first embodiment of the present invention. The valve timing adjustment device 1 is mainly composed of a continuous phase variable unit 10, a hydraulic control unit 30, and a storage unit 40. Continuous phase variable unit 10
Is a vane type phase changing unit, and has a housing 12 fixed integrally with the sprocket 11 and a vane 20 fixed to the drive shaft 2. The sprocket 11 transmits a driving force to a cam shaft, which is a driven shaft (not shown). A hydraulic chamber is formed between the housing 12 and the vane 20, and the hydraulic chamber is composed of the vane portion 2 of the vane 20.
1 is divided into an advance hydraulic chamber 22 and a retard hydraulic chamber 23. In the advance hydraulic chamber 22 and the retard hydraulic chamber 23,
The advance oil passage 24 and the retard oil passage 25 communicate with each other. By intermittently supplying the hydraulic oil to the advance hydraulic chamber 22 and the retard hydraulic chamber 23, the vane 20 rotates to the advance side or the hydraulic side, and the phase of the driving force transmitted from the drive shaft 2 to the driven shaft is changed. Is changed.

The hydraulic control unit 30 is a flow path switching valve that switches the oil passage of the hydraulic oil discharged from the oil pump 3.
The hydraulic control unit 30 is a spool valve that is axially driven by the balance of the forces of the spring 31 and an electromagnetic drive unit (not shown). The hydraulic control unit 30 switches the oil passage through which the hydraulic oil flows and controls the flow rate of the hydraulic oil supplied to the continuous phase variable unit 10. The hydraulic control unit 30 connects the hydraulic oil supply passage 4 communicating with the oil pump 3 or the drain oil passage 32 for discharging hydraulic oil, and the advance oil passage 24 or the retard oil chamber 23 communicating with the advance hydraulic chamber 22. The communication with the retard oil passage 25 communicating therewith is switched. That is, the hydraulic control unit 30 controls the flow rate and hydraulic pressure of the hydraulic oil supplied to the continuous phase variable unit 10 by switching the oil passage of the hydraulic oil supplied from the oil pump 3 to the continuous phase variable unit 10.

The oil pump 3 is driven in synchronization with an engine (not shown). The oil pump 3 pressurizes the hydraulic oil stored in an oil pan (not shown) to a predetermined pressure. The hydraulic oil discharge side of the oil pump 3 is branched into an oil passage 33 communicating with each part of the engine (not shown) and a hydraulic oil supply passage 4 communicating with the continuous phase varying part 10. Part of the hydraulic oil discharged from the oil pump 3 is supplied to each part of the engine, and the other part is supplied to the continuous phase variable part 10 via the storage part 40 and the hydraulic control part 30. Continuous phase variable unit 1
The unnecessary working oil of the working oil supplied to 0 and the unnecessary working oil supplied to each part of the engine are returned to an oil pan (not shown). The hydraulic oil recirculated to the oil pan is again discharged by the oil pump 3 to each part of the engine or the continuous phase variable part 10.

The storage unit 40 is installed in the hydraulic oil supply passage 4 which communicates from the oil pump 3 to the continuous phase changing unit 10. The storage unit 40 has a storage container 41, a hydraulic piston 42, and a spring 43 as an urging means. The storage container 41 accommodates a hydraulic piston 42 therein such that it can reciprocate. The hydraulic piston 42 divides the inside of the storage container 41 into an oil chamber 44 in which hydraulic oil is stored and a storage chamber 45 in which a spring is stored. Hydraulic piston 42
Is urged by the spring 43 toward the side where the volume of the oil chamber 44 is reduced. Therefore, the hydraulic piston 42 stops at a position where the urging force of the spring 43 and the force acting on the hydraulic piston 42 from the hydraulic oil stored in the oil chamber 44 are balanced inside the storage container 41. Then, the hydraulic piston 42 causes the oil chamber 44 and the storage chamber 45 to move inside the storage container 41.
It is divided into and. As a result, when hydraulic oil is discharged from the oil pump 3 to the hydraulic pressure supply oil passage 4, the hydraulic piston 4
2 is compressed against the urging force of the spring 43, and the oil chamber 4
Hydraulic oil is stored in 4. The volume of the storage container 41 is set to be equal to or larger than the total volume of the advance hydraulic chamber 22 and the retard hydraulic chamber 23 formed between the housing 12 and the vane 20.

The urging force of the spring 43 is generated by the hydraulic oil discharged from the oil pump 3 and stored in the oil chamber 44 during idling of the engine at high temperature.
It is set to be almost the same as the force acting on. Here, the high-temperature engine means an engine in a state where the warm-up operation is completed and the temperature has risen to a predetermined level. Therefore, when the continuous phase variable unit 10 is not operating, that is, when the hydraulic oil is not supplied to the continuous phase variable unit 10, the force acting on the hydraulic piston 42 from the hydraulic oil is larger than the biasing force of the spring 43. . As a result, in the above case, the oil chamber 44
The hydraulic oil is always stored in.

Between the storage unit 40 and the hydraulic control unit 30,
A check valve 5 as a check valve is installed. The check valve 5 prevents backflow of the hydraulic oil supplied from the storage unit 40 to the hydraulic control unit 30. That is, the hydraulic control unit 3
The flow of hydraulic oil from 0 to the storage unit 40 is prevented. This prevents the pressure drop of the hydraulic oil due to the reverse flow of the hydraulic oil.

Next, the operation of the valve timing adjusting device 1 according to the first embodiment of the present invention will be described. By switching the hydraulic control unit 30 as shown in FIG. 2, the hydraulic oil supply passage 4 and the advance oil passage 24 communicate with each other, and the drain oil passage 32
And the retard oil passage 25 communicate with each other. As a result, the hydraulic oil discharged from the oil pump 3 is supplied to the advance hydraulic chamber 22 and the hydraulic oil in the retard hydraulic chamber 23 is discharged to the drain. As a result, the hydraulic pressure in the advance hydraulic chamber 22 becomes larger than the hydraulic pressure in the retard hydraulic chamber 23, and the vane 20 rotates in the advance direction shown in FIG.

At this time, a force acts on the cam shaft (not shown) to which the driving force is transmitted through the sprocket 11 when the valve is driven, so that the cam shaft is rotated as shown in FIG. 3 (A). As a result, torque fluctuations occur. In FIG. 3A, the torque acting in the direction of retarding the camshaft is a positive torque, and the torque acting in the direction of advancing the camshaft is a negative torque.

The engine speed is low and the oil pump 3
When the flow rate and the hydraulic pressure of the hydraulic oil discharged from the camshaft are insufficient, if the vane 20 tries to rotate to the advance side when the torque in the advance direction acts on the camshaft, the advance hydraulic pressure is increased. Not enough hydraulic oil flows into the chamber 22.
Therefore, as shown in FIG. 3 (B), the pressure of the hydraulic oil in the advance hydraulic chamber 22 and the advance oil passage 24 decreases, forming a kind of damper. As a result, the rotation of the vane 20 toward the advance side is hindered, and the response is deteriorated.

By installing the storage unit 40 between the oil pump 3 and the hydraulic control unit 30 as in the present embodiment,
The hydraulic oil is replenished to the advance oil passage 24 and the advance hydraulic chamber 22 from the storage unit 40 which is closer to the continuous phase variable unit 10 than the oil pump 3. Therefore, as shown in FIG. 3 (B), a decrease in the hydraulic pressure of the advance hydraulic chamber 22 and the advance oil passage 24 is suppressed,
The operation response of the continuous phase variable section 10 is improved.

On the other hand, when torque in the retard direction acts on the camshaft during rotation in the advance direction, the advance hydraulic chamber 22
Oil pressure rises. Therefore, the hydraulic oil in the advance hydraulic chamber 22 flows out to the hydraulic control unit 30 via the advance oil passage 24. In this embodiment, since the check valve 5 is installed between the hydraulic control unit 30 and the storage unit 40, the hydraulic oil flowing out of the advance hydraulic chamber 22 does not flow back to the storage unit 40.
Then, when the check valve 5 is activated and shuts off the flow of hydraulic oil from the hydraulic control unit 30 to the storage unit 40, the hydraulic oil discharged from the oil pump 3 is stored in the oil chamber 44 of the storage unit 40.
Stored in. Since the volume of the storage container 41 of the storage section 40 is set to be equal to or larger than the total volume of the advance hydraulic chamber 22 and the retard hydraulic chamber 23, even when the vane 20 moves from the most retarded position to the most advanced position. The hydraulic oil supplied from the storage unit 40 to the continuous phase variable unit 10 does not run short.

When the operation of the continuous phase variable section 10 is completed,
The valve timing adjusting device 1 shifts to the holding mode.
That is, the hydraulic pressures of the advance hydraulic chamber 22 and the retard hydraulic chamber 23 are balanced with each other, and the vane 20 is held in a state where it does not rotate to the advance side or the retard side. At this time, the advance oil pressure chamber 22 is replenished with a flow rate of the operation oil corresponding to the leakage of the operation oil from each part including the continuous phase variable portion 10, and the oil pressure in the advance oil pressure chamber 22 due to the leakage of the operation oil is increased. The decline is prevented. At the same time, the storage unit 40 is replenished with the working oil discharged from the oil pump 3 in preparation for the subsequent operation.

Even when the vane 20 rotates in the retard angle direction, when the torque in the retard angle direction acts on the camshaft, the oil pressure in the retard angle hydraulic chamber 23 and the retard oil passage 25 decreases. However, even in this case, the hydraulic oil is replenished from the storage unit 40 to the retard hydraulic chamber 23 and the retard oil passage 25. Therefore, similarly to the case of the rotation in the advance direction, the operation response of the continuous phase variable unit 10 is improved in the rotation in the retard direction.

In the valve timing adjusting apparatus 1 according to the first embodiment described above, the storage section 40 is installed between the oil pump 3 and the continuous phase changing section 10. Therefore, when the engine speed is low, the oil pump 3
When the flow rate and hydraulic pressure of the hydraulic oil discharged from the tank are low, the hydraulic oil is replenished from the storage unit 40 to the continuous phase variable unit 10. As a result, the hydraulic pulsation of the hydraulic oil supplied to the continuous phase variable unit 10 is reduced. Therefore, the operation response of the continuous phase variable section 10 can be improved without the operation of the continuous phase variable section 10 being hindered as the hydraulic pressure of the hydraulic oil decreases.

The storage unit 40 is constantly supplied with hydraulic oil from the oil pump 3. Storage container 4 of storage unit 40
1 has a volume equal to or larger than the total volume of the advance hydraulic chamber 22 and the retard hydraulic chamber 23 of the continuous phase variable unit 10. Therefore, it is possible to replenish the working oil necessary for the operation of the continuous phase variable unit 10 without any shortage. Therefore, the continuous phase variable section 10 can be reliably operated regardless of the operating state of the engine.

Further, a check valve 5 is installed in the hydraulic pressure oil supply passage 4. Therefore, due to torque fluctuation, vane 2
Even when a torque acts on the camshaft in the direction opposite to the rotation direction of 0, the reverse flow of the hydraulic oil from the continuous phase variable unit 10 to the storage unit 40 can be prevented. Therefore, the operation response of the continuous phase variable section 10 can be surely improved.

(Second Embodiment) FIG. 4 shows a valve timing adjusting device according to a second embodiment of the present invention. In the second embodiment, the storage unit 50 is different from that of the first embodiment. Except for the storage unit 50, it is the same as the first embodiment, so the explanation is omitted. As shown in FIG. 5, the storage unit 50 mainly includes a storage container and a piston 6.
1 and a spring 62. The storage container is composed of a cover 51 and a body 52, and the cover 51 and the body 52 are integrally fixed by a bolt 53. The cover 51 is formed in a cylindrical shape having a bottom, and the piston 61 is movable inside. Cover 51
An accommodation chamber 63 is formed between the and the piston 61, and the spring 62 is accommodated in the accommodation chamber 63. Piston 6
1 is composed of a bottom portion 611 and a cylindrical portion 612,
A flange portion 613 extending outward in the radial direction is formed at an end portion of the tubular portion 612 on the side opposite to the bottom portion. One end of the spring 62 is in contact with the bottom 511 of the cover 51 and the other end is in contact with the flange 613 of the piston 61, and urges the piston 61 toward the body 52. The body 52 is
It is composed of a pedestal portion 521 and a protruding portion 522. The outer peripheral surface of the protruding portion 522 of the body 52 and the cylinder portion 61 of the piston
The inner peripheral surface of 2 can slide.

The body side of the bottom portion 611 of the piston 61, that is, the inner bottom surface 61a and the end surface 5 of the projecting portion 522 of the body 52.
A first oil chamber 71 is formed between the first oil chamber 71 and the 2a as shown in FIG. When the working oil is supplied to the first oil chamber 71, the pressure of the working oil in the first oil chamber 71 acts on the inner bottom surface 61 a of the piston 61. That is, the inner bottom surface 61a of the piston 61
Is the first pressure receiving surface. In addition, the flange portion 6 of the piston 61
A second oil chamber 72 is formed between the end surface of 13 on the body 52 side, that is, the outer end surface 61b and the end surface 52b of the pedestal portion 521 of the body 52. When the hydraulic oil is supplied to the second oil chamber 72, the pressure of the hydraulic oil in the second oil chamber 72 acts on the outer end surface 61b of the piston 61. That is, the outer end surface 61b of the piston 61 serves as the second pressure receiving surface.

As shown in FIG. 5, the body 52 has a pilot oil passage 81. A part of the hydraulic oil output from the oil pump 3 shown in FIG. 4 is boosted by a booster (not shown) and supplied to the pilot oil passage 81. A pilot valve 6 is installed in the pilot oil passage 81 as shown in FIG. 4, and the pilot oil pressure is supplied to the pilot oil passage 81 when the pilot valve 6 is opened and closed.

As shown in FIG. 5, the body 52 has a spool chamber 82 for accommodating the spool valve 7. The spool valve 7 is housed in the spool chamber 82 so as to be movable in the axial direction. A pilot oil passage 81 communicates with the spool chamber 82. A spring 83 is housed in the spool chamber 82, and the spring 83 biases the spool valve 7 in a direction opposite to the force applied to the spool valve 7 by the pilot hydraulic pressure. Therefore, when the pilot hydraulic pressure is supplied to the spool chamber 82, the spool valve 7 moves to the spring 83.
It moves downward in FIG. 5 against the urging force of. On the other hand, when the pilot hydraulic pressure is not supplied to the spool chamber 82, the spool valve 7 moves upward in FIG. 5 by the biasing force of the spring 83.

A lock portion 90 is formed in the body 52, and a lock pin 91 is accommodated in the lock portion 90 so as to be capable of reciprocating in the axial direction. The lock pin 91 is formed in a cylindrical shape and has a step portion 92 on the outer peripheral portion. A pilot oil chamber 93 is formed between the inner wall of the body 52 and the step portion 92 of the lock pin 91, and the pilot oil chamber 93 communicates with the pilot oil passage 81. On the other hand, a lock spring 94 is housed inside the lock pin 91. The tip portion 91a of the lock pin 91 can be fitted into the groove portion 64 formed in the inner wall portion of the piston 61. The tip portion 91a of the lock pin 91 is provided with the groove portion 64 of the piston 61.
The movement of the piston 61 is restricted by fitting it to.

The lock spring 94 biases the lock pin 91 in a direction opposite to the force acting on the lock pin 91 by the hydraulic pressure of the pilot oil chamber 93. Therefore, when the pilot oil pressure is supplied to the pilot oil chamber 93, the lock pin 91 moves downward in FIG. 5 against the biasing force of the lock spring 94. Meanwhile, the pilot oil chamber 9
When the pilot hydraulic pressure is not supplied to 3, the lock pin 91 moves upward in FIG. 5 by the urging force of the lock spring 94.

The body 52 has an inlet oil passage 84 communicating with the oil pump 3 and an outlet oil passage 85 communicating with the hydraulic control unit 30. The inlet oil passage 84 and the outlet oil passage 85 are connected by a main oil passage 86, and the check valve 8 as a check valve is installed in the main oil passage 86. The check valve 8 opens the main oil passage 86 when the hydraulic pressure of the hydraulic oil in the inlet oil passage 84 is higher than the hydraulic pressure of the hydraulic oil in the outlet oil passage 85, so that the hydraulic oil from the inlet oil passage 84 to the outlet oil passage 85 is opened. Allow the flow of. On the other hand, the hydraulic pressure of the hydraulic oil in the outlet oil passage 85 is
When it is higher than the hydraulic pressure of the hydraulic oil, the check valve 8 shuts off the main oil passage 86 to prevent the backflow of the hydraulic oil from the outlet oil passage 85 to the inlet oil passage 84.

In the body 52, a drain oil passage 87 through which hydraulic oil is discharged, a first oil passage (not shown) that connects the outlet oil passage 85 and the first oil chamber 71, and a spool chamber 82 and a second oil passage. A second oil passage 88 that communicates with the chamber 72 is formed. By moving inside the spool chamber 82, the spool valve 7 connects and disconnects the communication between the inlet oil passage 84 and the second oil passage 88 and the communication between the second oil passage 88 and the drain oil passage 87.

Next, the operation of the valve timing adjusting device 1 according to the second embodiment will be described. When the oil pump 3 is not operating, such as when the engine is stopped, the hydraulic oil is not discharged from the oil pump 3, so that no hydraulic oil is supplied to each part. Therefore, in the storage unit 50, as shown in FIG. 5, the piston 61 moves to the body 52 side, that is, the leftmost side in FIG. 5, by the urging force of the spring 62, and the inner bottom surface 61a of the piston 61 contacts the end surface 52a of the protrusion 522. Touching. In addition, the spool valve 7 and the lock pin 91
Since the pilot hydraulic pressure is not applied to the spool valve 7, the spool valve 7 is moved upward in FIG. 5 by the biasing force of the spring 83 and the lock pin 91 by the biasing force of the lock spring 94.

When the engine is started and the oil pump 3 is activated, hydraulic oil is discharged from the oil pump 3. The discharged hydraulic oil flows from the inlet oil passage 84 into the storage unit 50 via the hydraulic pressure supply oil passage 4. At this time, the inlet oil passage 8
Since the hydraulic pressure of 4 is higher than the hydraulic pressure of the outlet oil passage 85, the check valve 8 is opened. Therefore, the hydraulic oil flowing from the inlet oil passage 84 flows to the outlet oil passage 85 via the main oil passage 86. At this time, the pilot oil pressure is not acting on the spool valve 7. Therefore, the spool valve 7 is positioned above in FIG. 5 by the urging force of the spring 83, and the inlet oil passage 8
4 and the second oil passage 88 communicate with each other. As a result, the hydraulic oil that has flowed in from the inlet oil passage 84 partially passes from the outlet oil passage 85 through the first oil passage (not shown), the first oil chamber 71, and the second oil passage 88. While flowing into the second oil chamber 72, the others flow out from the outlet oil passage 85 via the main oil passage 86. The hydraulic oil flowing out from the outlet oil passage 85 is supplied to the continuous phase variable unit 10 via the hydraulic pressure control unit 30.

By supplying hydraulic oil to the first oil chamber 71 and the second oil chamber 72, the inner bottom surface 61a of the piston 61 is
The hydraulic pressure of the hydraulic oil in the first oil chamber 71 acts on the outer end surface 61b.
The hydraulic pressure of the hydraulic oil in the second oil chamber 72 acts on. Therefore, a force against the urging force of the spring 62 acts on the piston 61, and the piston 61 moves toward the bottom portion 511 of the cover 51.
Move to the side, that is, to the right in FIG.

As the working oil is supplied to the first oil chamber 71 and the second oil chamber 72, the piston 61 covers the cover 5
1, the piston 61 stops moving at the position where the bottom portion 611 of the piston 61 and the bottom portion 511 of the cover 51 contact each other as shown in FIG. Piston 61
When the bottom portion 611 and the bottom portion 511 of the cover 51 are in contact with each other, the tip end portion 91a of the lock pin 91 and the groove portion 64 of the piston 61 face each other. At this time, since the pilot valve 6 shown in FIG. 4 remains closed, the pilot oil pressure does not act on the lock pin 91. for that reason,
The tip portion 91a of the lock pin 91 is formed in the groove portion 6 of the piston 61.
4, the movement of the piston 61 is restricted.

The tip 91a of the lock pin 91 is fitted into the groove 64 of the piston 61, and the movement of the piston 61 is restricted, so that the hydraulic pressure of the working oil in the first oil chamber 71 and the second oil chamber 72 changes. However, the piston 61 does not move. Therefore, due to a decrease in engine speed,
Even when the pressure and flow rate of the hydraulic oil discharged from the oil pump 3 decrease, the first oil chamber 71 and the second oil chamber 72
The stored hydraulic oil is retained in the.

When the oil pressure and the flow rate of the hydraulic oil discharged from the oil pump 3 decrease as the engine speed decreases, the oil pump 3 cannot supply sufficient hydraulic oil to the continuous phase variable section 10. Therefore, the pilot valve 6 shown in FIG. 4 is opened, and as shown in FIG.
The pilot hydraulic pressure is applied to the spool valve 7 and the lock pin 91 of 0. When the pilot hydraulic pressure is applied, the spool valve 7 moves downward in FIG. 7 against the biasing force of the spring 83, and the lock pin 91 moves downward in FIG. 7 against the biasing force of the lock spring 94. When the lock pin 91 moves downward in FIG. 7, the piston 61 can move again. Further, by moving the spool valve 7 downward in FIG. 7, the communication between the inlet oil passage 84 and the second oil passage 88 is cut off, and the second oil passage 88 and the drain oil passage 87 communicate with each other. Therefore, the hydraulic pressure of the hydraulic oil in the second oil chamber 72 decreases. Therefore, the piston 61 moves toward the pedestal portion 521, that is, to the left in FIG. 7 by the urging force of the spring 62.

At this time, the hydraulic pressure of the hydraulic oil in the second oil chamber 72 does not act on the outer end surface 61b of the piston 61, and the first oil chamber 71
Only the hydraulic pressure of the hydraulic oil acts on the inner bottom surface 61 a of the piston 61. The hydraulic oil is supplied to the first oil chamber 71 and the second oil chamber 72.
When the piston 61 moves toward the bottom portion 511 of the cover 51, the pressure of the hydraulic oil acts on the inner bottom surface 61a from the first oil chamber 71 and on the outer end surface 61b from the second oil chamber 72 to cause the spring 62 to move. While compressed, when the hydraulic oil is discharged, that is, when the piston 61 moves toward the body 52 as shown in FIG. 8, the spring 62 resists only the pressure of the hydraulic oil in the first oil chamber 71. Drive the piston 61. As a result, when the area of the inner bottom surface 61a of the piston 61 on which the hydraulic pressure of the first oil chamber 71 acts is S1 and the area of the outer end surface 61b of the piston 61 on which the hydraulic pressure of the second oil chamber 72 acts is S2, the first Oil chamber 7
The hydraulic oil discharged from 1 to the outlet oil passage 85 is (S1 + S
2) The pressure increases by the amount corresponding to / S2. When the pressure in the outlet oil passage 85 rises, the check valve 8 closes the main oil passage 86, so that the working oil in the outlet oil passage 85 does not flow back to the inlet oil passage 84. Therefore, the hydraulic oil that is pressurized from the first oil chamber 71 and discharged to the outlet oil passage 85 is supplied to the continuous phase variable unit 10.

In the second embodiment, when the flow rate and pressure are insufficient only with the hydraulic oil discharged from the oil pump 3,
The hydraulic oil stored in the storage unit 50 is pressurized and supplied to the continuous phase variable unit 10. Therefore, the responsiveness of the continuous phase variable unit 10 driven by hydraulic pressure can be improved. Further, the storage unit 50 pressurizes the hydraulic oil and supplies it to the continuous phase variable unit 10. Therefore, even if the pressure of the hydraulic oil discharged from the oil pump 3 is reduced, the hydraulic pressure required for operating the continuous phase variable unit 10 is maintained. Therefore, the hydraulic pressure can always be supplied to the continuous phase varying section 10 regardless of the engine speed, that is, the operating state of the engine, and the operation response of the continuous phase varying section 10 can be improved.

Further, in the second embodiment, even when the engine is stopped and the operation of the oil pump 3 is stopped, for example,
The storage unit 50 can supply hydraulic pressure to the continuous phase variable unit 10. Therefore, not only the fuel efficiency, output and emission of the engine can be improved, but also the engine can be started regardless of the phase of the continuous phase variable section 10.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a valve timing adjusting device according to a first embodiment of the present invention.

FIG. 2 is a schematic view showing the valve timing adjusting device according to the first embodiment of the present invention, and is a view showing a state in which the vane rotates toward the advance side.

FIG. 3A is a diagram showing the relationship between the rotation angle of the drive shaft and the drive torque acting on the camshaft, and FIG. 3B is a view showing the relationship between the drive shaft, the rotation angle, and the hydraulic pressure of each hydraulic chamber. It is a figure.

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

FIG. 5 is a schematic cross-sectional view showing a storage portion of a valve timing adjusting device according to a second embodiment of the present invention, showing a state in which hydraulic oil is being supplied to a first oil chamber and a second oil chamber. It is a figure.

FIG. 6 is a schematic cross-sectional view showing a storage portion of a valve timing adjusting device according to a second embodiment of the present invention, showing a state where the first oil chamber and the second oil chamber are filled with hydraulic oil. Is a figure

FIG. 7 is a schematic cross-sectional view showing a storage portion of a valve timing adjusting device according to a second embodiment of the present invention, showing a state in which pilot oil pressure is acting on a spool valve and a lock pin.

FIG. 8 is a schematic cross-sectional view showing a storage portion of a valve timing adjusting device according to a second embodiment of the present invention, showing a state in which hydraulic oil is being discharged from a first oil chamber and a second oil chamber. It is a figure.

[Explanation of symbols]

1 Valve timing adjustment device 2 drive shaft 3 oil pump 5, 8 check valve (check valve) 10 Continuous phase variable section 30 Hydraulic control unit 40 Storage 41 Storage container 42 hydraulic piston 43 spring 44 oil chamber 45 accommodation room 50 storage 51 cover (storage container) 52 body (storage container) 61 pistons 61a Inner bottom surface (first pressure receiving surface) 61b Outer end surface (second pressure receiving surface) 62 spring 63 accommodation room 71 First oil chamber 72 Second oil chamber

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Jun Yamada             14 Iwatani Shimohakaku-cho, Nishio-shi, Aichi Stock Association             Company Japan Auto Parts Research Institute (72) Inventor Shigeyuki Kusano             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO F-term (reference) 3G018 AB02 BA09 BA10 BA33 CA19                       CA20 DA54 FA01 FA07 GA03                       GA38

Claims (5)

[Claims] 1. A drive force transmission system for transmitting a drive force from a drive shaft of an internal combustion engine to a driven shaft that opens and closes at least one of an intake valve and an exhaust valve, and at least the intake valve and the exhaust valve. A valve timing adjusting device for adjusting the opening / closing timing of any one of the above, wherein a hydraulic control means for controlling the hydraulic pressure of hydraulic oil supplied to a continuous phase varying means capable of changing the phase of the driven shaft with respect to the drive shaft, A storage unit that is installed between an oil pump driven by an internal combustion engine and the hydraulic pressure control unit, and that stores operating oil supplied from the oil pump to the hydraulic pressure control unit while maintaining hydraulic pressure. A valve timing adjustment device characterized by. 2. The storage means, a storage container, a piston that moves inside the storage container to divide the storage chamber into an oil chamber and a storage chamber, and the storage chamber accommodates the piston to reduce the volume of the oil chamber. 2. The valve timing adjusting device according to claim 1, further comprising an urging means for urging the valve timing. 3. The urging force of the urging means is substantially the same as the force acting on the piston by the hydraulic pressure of the hydraulic oil discharged from the oil pump at the time of idling after completion of the warm-up operation of the internal combustion engine. The valve timing adjusting device according to claim 2, wherein 4. A check valve for preventing the flow of hydraulic oil from the hydraulic control unit to the oil pump side is provided on the oil pump side of the hydraulic control unit. The valve timing adjustment device described. 5. The piston has a first pressure receiving surface and a second pressure receiving surface having different pressure receiving areas for receiving the pressure of the hydraulic oil,
The valve timing adjusting device according to claim 4, wherein the pressure of the hydraulic oil discharged from the oil chamber is increased by switching the hydraulic pressure applied to the first pressure receiving surface or the second pressure receiving surface.