JP2000213310A - Valve timing control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve control responsiveness to a spark advance side unrealizable in the effective utilization of a torque fluctuation in particular, particularly at the time of high rotation, of course at the time of an engine low rotation. SOLUTION: A relative turn phase between a timing sprocket 21 and a cam shaft is convertibly controlled by utilizing positive and negative torque fluctuation occurring in a cam shaft by a phase converting means 26. In the means 26, a pair of cylinders 34 and 35 are provided on both the end parts of a turn member 25 fixed to the cam shaft, and also plungers 38 and 39, for pressing abutting surfaces 31 and 32 equipped on the inner peripheral surface of a tubular main body 27, are slidably provided on the respective cylinders 34 and 35. The respective plungers can be moved by utilizing oil pressure directly supplied from an oil pump to respective pressure chambers 40 and 41 in tip head parts 38a and 39a via opening/closing valves 43 and 44.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing control device for an internal combustion engine, and more particularly to a valve timing control device for converting a relative rotational phase between a rotating body and a camshaft using an alternating torque basically generated on a camshaft. It relates to a control device.

[0002]

2. Description of the Related Art As a conventional valve timing control device of this type, for example, a device described in Japanese Patent Application Laid-Open No. 3-185204 is known.

[0003] In brief, referring to Fig. 13, a sprocket (not shown) rotatably driven by a crankshaft of an engine and a camshaft 1 supported on a cylinder head are provided so as to be relatively rotatable. A hydraulic body provided on the sprocket supports a pair of hydraulic cylinders 2 and 3 disposed on a longitudinally opposite side of the camshaft 1, and has a piston 4 in each of the cylinders 2 and 3.
5 is slidably provided. In addition, each cylinder 2,
3, a hydraulic pressure supply passage 6 and a pair of return passages 7, 8 are connected, and a passage switching valve 9 is provided in each of the passages 6, 7, 8. Further, a check valve 1 for restricting the reverse flow of the hydraulic pressure from each of the cylinders 2 and 3 to the hydraulic supply passage 6 is provided in the branch passages 6 a and 6 b on the downstream side of the hydraulic supply passage 6.
0 and 11 are provided, and a closed circuit state is provided between the cylinders 2 and 3.

The camshaft 1 has positive and negative alternating torque fluctuations caused by a spring reaction force of a valve spring and the like. The relative rotation phase between the sprocket and the camshaft 1 is changed by causing the pistons 4 and 5 to advance or retreat relatively. As a result, the opening / closing timing of the engine valve is variably controlled in accordance with the operating state of the engine to improve the performance of the engine.

[0005]

However, according to the conventional valve timing control apparatus, as described above, the hydraulic pressure is relatively controlled between the cylinders 2 and 3 by utilizing only the variation in the alternating torque of the camshaft 1. Supply and discharge camshaft 1
The relative rotation phase between the motor and the sprocket is changed, so that the alternation torque fluctuation can be used efficiently in the low rotation speed range including the idling operation of the engine, but the usage efficiency is improved from the middle rotation speed especially in the high rotation speed range. It will drop significantly.

That is, in the low engine speed region, the fluctuation period of the torque fluctuation per time becomes long, so that a sufficient torque reversing force can be obtained. However, especially in the high rotation region, the fluctuation period becomes short. There is a possibility that the flow speed of the hydraulic oil between the cylinders 2 and 3 is reduced, and the forward / backward responsiveness of the pistons 4 and 5 is deteriorated. As a result, the responsiveness of the valve timing control according to the engine operating state is not only deteriorated, but also the desired valve timing control at the time of high rotation may not be obtained.

[0007]

SUMMARY OF THE INVENTION The present invention has been devised in view of the actual situation of the conventional valve timing control apparatus, and the invention according to claim 1 has a rotating mechanism driven by a crankshaft of an engine. A rotating body, a camshaft provided rotatably with respect to the rotating body, and having a cam on an outer periphery thereof for opening an engine valve, and a phase converting means for relatively rotating the rotating body and the camshaft. A valve timing control device that controls the opening / closing timing of the engine valve to advance or retard by changing the relative rotational phase of the rotating body and the camshaft by the phase conversion means. A plurality of cylinders provided in the rotating body, a plurality of plungers slidably provided in the respective cylinders in the forward and backward directions for relatively rotating the rotating body and the camshaft; A plurality of pressure chambers formed in the inside of the plunger for relatively moving the plungers forward and backward by hydraulic pressure supplied from a fluid pump via a check valve, and supplying and discharging hydraulic pressure to and from each of the pressure chambers And a conversion mechanism for converting a linear motion of the plunger sliding in the cylinder into a rotary motion for relatively rotating the rotating body and the camshaft. It is characterized by:

According to a second aspect of the present invention, the switching mechanism comprises:
It is characterized in that it is constituted by an on-off valve which operates by receiving the liquid pressure discharged from the fluid pump.

According to a third aspect of the present invention, the conversion mechanism comprises:
A rotating member fixed to the camshaft and provided with the cylinder at both ends in the camshaft radial direction, and a contact portion provided on an inner surface of the rotating body and contacting a tip end of each plunger. It is characterized by doing.

According to a fourth aspect of the present invention, the contact surface of each of the contact portions is formed in a curved shape.

The invention according to claim 5 is characterized in that the check valve is provided near a pressure chamber in each plunger.

According to a sixth aspect of the present invention, the switching mechanism is provided inside each of the plungers.

According to a seventh aspect of the present invention, there is provided a signal hydraulic system for sliding an open / close valve in the other plunger in the opening direction of the discharge passage in the supply passage for supplying a hydraulic pressure to the pressure chamber of the one plunger. The signal path for sending the signal is branched.

The invention according to claim 8 is characterized in that a part of the supply passage and the signal passage are constituted by one continuous straight passage hole.

According to a ninth aspect of the present invention, the downstream end of the front discharge passage is communicated with a space formed between the outer surface of the rotating member and the inner surface of the rotating body.

According to a tenth aspect of the present invention, when the relative rotation position between the rotating body and the camshaft is controlled to an intermediate position between the most advanced angle and the most retarded angle, the control is performed via each of the on-off valves. Each pressure chamber communicates with the supply passage, and the respective on-off valve shuts off the respective discharge passage.

The invention according to claim 11 is characterized in that when the engine is stopped, the check valve keeps the hydraulic pressure in the pressure chamber and the switching mechanism shuts off the discharge passage.

[0018]

1 and 2 show an embodiment of a valve timing control device according to the present invention. That is,
A timing sprocket 21 as a rotating body that is rotationally driven from a crankshaft of the engine via a timing chain;
A cam shaft 22 rotatably supported by a cam bearing 23 on the cylinder head 20 and provided rotatably relative to the timing sprocket 21, and is fixed to one end of the cam shaft 22 by a fixing bolt 24 in the axial direction. Rotating member 25 rotating within timing sprocket 21, and rotating member 25 and timing sprocket 21
And the phase conversion means 26 provided between them.

The timing sprocket 21 is shown in FIG.
As shown in FIG. 3, a substantially annular sprocket portion 28 provided at the rear end of the cylindrical main body 27 and an annular front cover 29 for closing the front end opening of the cylindrical main body 27 are provided. 28 and 29 are integrally fastened and fixed together in the axial direction by four bolts 30. In addition, the cylindrical main body 2
7, a substantially trapezoidal boss portion 27a, 27b is integrally provided at a position facing the inner peripheral surface as shown in FIG. 1, and the bolts 30 are provided at both ends of the boss portion 27a, 27b. Four bolt insertion holes 27c to be inserted are formed to penetrate in the axial direction. Further, the boss portion 27a on one side (left side in the figure) is a contact portion, and a pair of arc-shaped contact surfaces 31, 32 is formed on both side surfaces thereof. Further, the sprocket portion is provided with a discharge port 28 for discharging the hydraulic oil in the space portion 62 to the outside at a symmetric position of 180 ° in the circumferential direction.
a, 28b are formed to penetrate in the axial direction.

As shown in FIG. 2, the camshaft 22 has a journal portion 22c between the front and rear flange portions 22a and 22b provided at the front end portion.
a, and a bolt screw hole 22d is formed in the direction of the inner axial center of the distal end portion. A drive cam 33 for opening an engine valve such as an intake valve is integrally provided at a predetermined position on the outer periphery of the camshaft 22 against a spring force of a valve spring (not shown).

The rotating member 25 has a substantially rectangular shape in front, and has a bolt hole 2 in the center of which the fixing bolt 24 is inserted.
5a is formed through and as shown in FIG.
A first cylindrical portion 25b at the center of the rear end and a second cylindrical portion 25c at the center of the front end are rotatably provided in a first support hole 28c in the center of the sprocket portion 28 and a second support hole 29a in the center of the front cover 29, respectively. Supported. The front and rear end surfaces are slidably supported by the opposing inner surfaces of the sprocket portion 28 and the front cover 29.

The phase conversion means 26 is provided with the rotating member 2.
5 and a pair of cylinders 34 and 35 formed in parallel with each other substantially in the tangential direction of the camshaft 22, and slidably provided inside the cylinders 34 and 35 via retainers 36 and 37. A pair of first and second plungers 3
8 and 39 and the heads 38 of the plungers 38 and 39
a, first and second pressure chambers 40, 41 formed in 39a
A hydraulic circuit 42 for supplying and discharging hydraulic pressure to the retainer 36,
The first and second on-off valves 43 and 44 are slidably provided on the rear end side of the valve 37 and are switching mechanisms for appropriately communicating or shutting off the discharge passage of the hydraulic circuit 42 and the low-pressure section (space section 62). It has.

Each of the cylinders 34, 35 has one end opening formed in the direction of each of the contact surfaces 31, 32, while the retainers 36, 37 are press-fitted and fixed to the bottom surface of the other end. .

Each of the retainers 36 and 37 is formed in a cylindrical shape having a uniform diameter, and has communication passages 36a and 37a formed in the center of a partition wall formed at the front end.

Each of the plungers 38, 39 has a substantially cylindrical shape, the inner peripheral surface of which is in sliding contact with the outer peripheral surfaces of the retainers 36, 37, and the partition walls of the retainers 36, 37 and the tip heads 38a, 39a. Coil spring 4 mounted between
It is urged in the advance direction by the spring force of 5,46. Also,
The tip heads 38a, 39a have their tip surfaces 38b, 39b
Are formed in the same curved surfaces as the respective contact surfaces 31 and 32.

In each of the pressure chambers 40, 41, there are provided first and second check valves 47, 48 comprising check balls and springs for opening and closing the communication passages 36a, 37a.
The check valves 47 and 48 allow the inflow of hydraulic oil only from the respective on-off valves 43 and 44 toward the respective pressure chambers 40 and 41.

Each of the on-off valves 43 and 44 has a spool shape, and has, at its front end, valve bodies 43a and 44a for opening and closing drain holes 57b and 58b of discharge passages 57 and 58, which will be described later. In the peripheral wall, supply passages 55, 5
6. Groove groove 43 communicating with communication holes 55b, 56b
b, 44b and through holes 43c, 44c are formed.
The through holes 43c, 44c communicate with the pressure chambers 40, 41 via the internal passages 43d, 44d of the on-off valves 43, 44 and the communication passages 36a, 37a. Further, the on-off valves 43 and 44 have signal passages 60 and 61 to be described later at their rear ends.
The pressure receiving chambers 49, 50 are formed to receive the signal oil pressure from the valve bodies 43a, 44a and to urge the drain holes 57b, 58b in a direction to open the drain holes 57b, 58b.
Return springs 51, 52 for urging the drain holes 57b, 58b in the direction of closing by the valve bodies 43a, 44a.
Is armed.

The hydraulic circuit 42 is shown in FIGS.
As shown in FIG. 7, an oil pump 54, which is a fluid pump provided upstream of an oil main gallery 53 that supplies lubricating oil to an engine sliding portion, and an advance supply passage 55 branched off downstream of the oil main gallery 53 And retard supply passage 5
6, discharge passages 57 and 58 connected between the check valves 47 and 48 and the pressure chambers 40 and 41, respectively, and a branch portion between the oil main gallery 53 and the supply passages 55 and 56. For example, a proportional control valve 59 is provided. The above-described on-off valves 43 and 44 are provided downstream of the discharge passages 57 and 58, and the signal passages 60 branch from the supply passages 55 and 56 and communicate with the pressure receiving chambers 49 and 50, respectively. , 61.

As shown in FIG. 2, the supply passages 55 and 56
3a through and from the camshaft 2 via a groove.
2 are formed substantially in parallel in the radial direction and the axial direction, and further, each supply hole 55a,
Each of the grooves is formed through the supply holes 55a, 56a and the passage holes 36b, 37b formed in the supply holes 55a, 56a and the retainers 36, 37, as shown in FIG. Communication hole 55 communicating with grooves 43b, 44b
b and 56b. Therefore, only the hydraulic oil from the oil pump 54 is supplied to the supply passages 55 and 56, and the hydraulic pressure affected by the torque fluctuation of the camshaft 22 is not supplied.

The communication holes 55b and 56b are formed in line with the respective signal paths 60 and 61 by drilling. In addition, at the open end of the signal passages 60 and 61,
The blind plug is press-fitted and fixed.

As shown in FIG. 1, each of the discharge passages 57, 58 is formed between the inner peripheral surfaces of the plungers 38, 39 and the retainer 36,
Drain grooves 57a, 58a formed in the axial direction between the outer peripheral surface of the front end portion 37 and the respective drain grooves 57a, 58
The drain holes 57b, 58b drilled in the radial direction of the retainers 36, 37 from the end of "a", the annular grooves 57c, 58c formed substantially in the center of the peripheral walls of the on-off valves 43, 44, and the retainers 36, 37 Discharge hole 5 formed near the center
7d, 58d, and axial grooves 57e, 58e formed between the inner peripheral surfaces of the cylinders 34, 35 and the outer peripheral surfaces of the plungers 38, 39 and communicating with the discharge holes.
The axial grooves 57e and 58e communicate with a space 62 formed between the inner peripheral surface of the cylindrical main body 27 and the outer surface of the rotating member 25.

The control valve 59 is switched by a control signal from a controller (not shown) for detecting the operating state of the engine based on information signals from a crank angle sensor, an air flow meter and the like.

In the following, the operation of the present embodiment will be described. First, the case where the engine speed is increased from the retard control state when the engine is running at a low speed and the advance control is performed will be described.

That is, in this case, the control valve 59 allows the oil main gallery 53 to communicate with the advance supply passage 55 as shown in FIG. And the drain passage 63 on the control valve 59 side. For this reason, the hydraulic oil (lubricating oil) pumped from the oil pump 54 to the oil main gallery 53 passes through the advancing supply passage 55 and the internal passage 43d of the first on-off valve 43 as shown in FIG. 36
a, the first check valve 47 is pushed open to open the first pressure chamber 40.
At the same time, the first on-off valve 43 is moved backward by the oil pressure in the internal passage 43 in cooperation with the spring force of the return spring 51 to the position shown in FIG.
Is closed. On the other hand, the communication hole 5 of the advance supply passage 55
A part of the hydraulic oil flowing into the hydraulic fluid 5b, as shown in FIG.
The gas flows into the second pressure receiving chamber 50 from the signal passage 60 and slides the second on-off valve 44 to the maximum forward position against the spring force of the return spring 52, so that the valve body 44a opens the drain hole 58b. For this reason, the hydraulic oil stored in the second pressure chamber 41 is discharged into the space 62 through the second discharge passage 58, so that the pressure in the second pressure chamber 41 becomes low, and at the same time, the supply for retardation is performed. Hydraulic oil existing in the passage 56 is also returned to the oil pan 64 via the drain passage 63.

Here, positive and negative rotational torque fluctuations generated on the camshaft 22 act on the rotating member 25. When a positive torque is applied, a force is applied in the compression direction of the first plunger 38, but the first pressure is applied. Since the chamber 40 is closed by the first check valve 47 and the first on-off valve 43, the first plunger 38 does not retreat. On the other hand, when a negative torque acts, a force in the compression direction acts on the second plunger 39 to retreat the second plunger 39 in the open-to-atmosphere state, but no compression force acts on the first plunger 38. The first plunger 38 moves forward by the high-pressure oil supplied into the first pressure chamber 40 because it is in a free state without acting.

The second plunger 39 moves backward by the repetitive action of the positive and negative torque fluctuations.
The first plunger 38 advances gradually and presses the contact surface 31 with the tip end portion 38a. As a result, the camshaft 22 rotates relative to the timing sprocket 21 on the advance side, that is, in the direction of the arrow in FIG. , While the second plunger 39 is compressed most, the first plunger 38 is advanced to the maximum and converts the phase to the most advanced angle side. As a result, it becomes possible to quickly shift the opening / closing timing of the engine valve to the advance side.

On the other hand, when the engine shifts from the high engine speed range to the low engine speed range, the control valve 5 is controlled by a control signal from the controller.
As shown in FIG. 7, this time the oil main gallery 5
At the same time, the advance supply passage 55 and the drain passage 63 are communicated with each other. For this reason, the hydraulic oil pressure-fed from the oil pump 54
And the second through the supply passage 56 for retardation as shown in FIG.
The second check valve 48 is pushed open from the internal passage 44a of the on-off valve 44 via the communication passage 37a to flow into the second pressure chamber 41, and at the same time, the second on-off valve 44 is pressed by the pressure in the internal passage 44d.
Moves backward, and the valve body 44a closes the drain hole 58b.
On the other hand, part of the hydraulic oil that has flowed into the communication hole 56 b of the retard supply passage 56 flows into the first pressure receiving chamber 49 from the first signal passage 61, and causes the first on-off valve 43 to return to the spring force of the return spring 51. The valve body 43a slides forward against the drain hole 5a.
7b is opened. For this reason, the hydraulic oil stored in the first pressure chamber 40 passes through the first discharge passage 57 and passes through the space 6.
As a result, the hydraulic oil existing in the advancing supply passage 55 is returned to the oil pan 64 at the same time as the pressure in the first pressure chamber 40 becomes low.

When a negative torque of the camshaft 22 acts on the second plunger 39 in the same manner as described above, a compression force is applied to the second plunger 39, but the inside of the second pressure chamber 41 becomes the second check valve 48.
The second plunger 39 does not move backward because the second check valve 44 and the second check valve 44 are closed. On the other hand, when a positive torque acts, a compressive force acts on the first plunger 38 to retreat the first plunger 38, but the second plunger 39 is in a free state, so the second pressure chamber 41
It advances by the high-pressure oil supplied inside.

Therefore, the first plunger 38 moves backward by the repetitive action of positive and negative torque fluctuations, while the second plunger 39 moves forward gradually and presses the contact surface 32 with the front end head 39a. Camshaft 2 by reaction force
8 is rotated relative to the timing sprocket 21 in the retard direction, that is, in the direction of the arrow in FIG. 8, and finally, as shown in FIG. Convert the phase. As a result, the opening and closing timing of the engine valve can be quickly shifted to the retard side.

As described above, in the present embodiment, the control to the retard side and the advance side is performed not only by using the positive and negative torque fluctuations of the camshaft 22 but also from the low engine speed range to the high engine speed range. In all operating ranges, the oil pump 54
Each plunger 38, 39 using the hydraulic pressure
Is made to advance forcibly, as shown by the solid line in FIG. 11, the operation time to the advance side or the retard side, that is, the control response is greatly improved.

In particular, even when the positive torque fluctuation at the time of high engine speed cannot be sufficiently utilized, the first plunger 38 can be quickly advanced as described above.
It is possible to improve the conversion responsiveness of the relative rotation phase of the two 21 and 22 to the advance side.

Further, since the inside of each pressure chamber 40, 41 can be closed by the check valves 47, 48 and the on-off valves 43, 44, for example, the control speed from the retard side to the advance side can be reduced. As shown by the solid line 12, the control response is much faster than when no check valve or the like is provided (broken line), and control responsiveness is further improved.

The pressure chambers 40 and 41 are connected to the first,
In order to discharge the hydraulic oil that has passed through the second discharge passages 55 and 56 into the space 62, the sliding lubrication of the plungers 38 and 39 and the gap between the tip surfaces 38b and 39b and the contact surfaces 31 and 32 are performed. Can be used for lubrication. Therefore, a smooth operation can always be obtained, and the occurrence of wear is suppressed, and the durability can be improved.

The hydraulic oil accumulated in the space 62 is discharged from the discharge ports 28a and 28b of the sprocket portion 28 as appropriate and used for lubrication between the sprocket portion 28 and the timing chain. Effective use of hydraulic oil can be achieved.

Further, the working oil is directly supplied from the oil pump 54 to each of the pressure chambers 40 and 41, and normal working oil without pulsation due to positive and negative torque fluctuations can be supplied. Operation can be stabilized.

Next, when the engine speed becomes a predetermined steady-state rotation range and the engine valve is controlled to an intermediate range between the most advanced angle and the retarded angle, as shown in FIG.
Makes both the advance and retard supply passages 55 and 56 communicate with the oil main gallery 53. Accordingly, the supply passages 55 and 56 and the communication passages 36 are provided in the pressure chambers 40 and 41, respectively.
Hydraulic pressure is supplied via a and 37a. On the other hand, the hydraulic pressure is also supplied to the pressure receiving chambers 49 and 50 via the signal passages 60 and 61, respectively.
Since the same oil pressure as that of the pressure receiving chambers 49 and 50 acts in the pressure receiving chamber 44d, the opposing oil pressures are offset, and thus the springs of the respective return springs 51 and 52 retreat and move backward.
The valve bodies 43a and 44a close the drain holes 57b and 58b, respectively. Therefore, the pressure chambers 40 and 41 are closed, and even if a relative compressive force is applied to the plungers 38 and 39 by positive and negative torques, the plungers 38 and 39 do not retract. As shown in FIG. 1, since the respective contact surfaces 31 and 32 are pressed against each other by the same pressure and abut against each other, the cam shaft 22 is held at the illustrated rotational position without relative rotation.

Here, the positive or negative torque instantaneously increases, and the plunger 38,
Even if 39 is retracted temporarily, it is advanced by the high oil pressure in the pressure chambers 40 and 41 at the next positive or negative torque, and quickly returns to the original position. Therefore, it is possible to stably and surely hold at the predetermined intermediate control position.

Next, when the engine is stopped in the most retarded control state in the low engine speed region, the supply of the hydraulic pressure from the delay supply passage 56 to the second pressure chamber 41 is stopped. Room 4
1 is maintained in a sealed state by the second check valve 48 and the second on-off valve 44, while the first pressure chamber 40 is
3 retreats due to the spring force of the return spring 51 and closes the drain hole 57d with the valve body 43a. Therefore, each plunger 38, 3
In the state 9, the most retarded operation state shown in FIG. 9 is maintained.

Therefore, when the engine is restarted, as shown in FIG. 10, until the oil pressure from the oil pump 54 rises, that is, until the oil pressure is sufficiently supplied to the second pressure chamber 41, both plungers 38 are turned on. , 39 are fixedly brought into contact with the respective contact surfaces 31, 32 without advancing and retreating, and a locked state is established. For this reason, even if positive and negative torque fluctuations act at this point, the rotating member 25 opposes this torque force.
The free forward and reverse rotation can be reliably restricted. As a result, it is possible to prevent the generation of a vibration tapping sound between each of the plungers 38, 39 and the contact surfaces 31, 32, and it is not necessary to provide another lock mechanism, so that the structure can be simplified. .

As described above, according to the present embodiment, as described above, not only can the control response to the advance and retard angles be improved, the control can be stably performed at the intermediate position, etc.
Since the 56 communication holes 55b and 56b and the signal passages 60 and 61 also serve as one linear passage hole, both passages can be formed simultaneously by one drilling when the passages are drilled, thereby improving work efficiency. And the passage configuration can be simplified.

[0051]

As is apparent from the above description, claim 1
According to the invention described above, each plunger is forcibly driven by hydraulic oil constantly supplied to each pressure chamber from a fluid pump, so that torque fluctuations cannot be effectively used, especially at high engine speeds. Can be quickly performed. As a result, the control response of the valve timing is improved.

According to the second aspect of the present invention, since the opening and closing operation of the on-off valve is performed by the supply hydraulic pressure, an expensive electromagnetic actuator is not required, so that the cost can be reduced and the structure can be simplified. I can do it.

According to the third aspect of the present invention, since the conversion mechanism is simply constituted by the rotating member and the contact member, the structure is simplified, and the sliding range of the plunger on the contact surface is extremely small. This eliminates the need for high machining accuracy of both, and facilitates machining of the contact surface and the plunger.

According to the fourth aspect of the present invention, since the contact surface and the plunger tip surface are curved, the contact surface pressure can be reduced, so that the occurrence of wear between them can be prevented.

According to the fifth aspect of the present invention, there is no need to provide a separate space for disposing the check valve. Therefore, the size can be reduced, and by providing the check valve in the vicinity of the pressure chamber, air may be mixed into the pressure chamber. Does not significantly affect the operation of the plunger.

According to the invention, since the switching mechanism is provided in the plunger, the structure can be made compact.

According to the seventh aspect of the present invention, since the signal path is branched from the supply path, the path configuration can be simplified.

According to the eighth aspect of the present invention, since a part of the supply passage and the signal passage are linearly integrated, both can be simultaneously formed by drilling, so that such forming work can be easily performed. Become.

According to the ninth aspect of the present invention, the lubricating oil discharged into the space improves the lubricating performance between the plunger tip surface and the contact surface, so that the occurrence of wear can be more reliably prevented.

According to the tenth aspect of the present invention, since both pressure chambers are sealed by the check valve and the on-off valve, even if positive and negative torques act, careless retreat of both plungers is restricted. Intermediate control can be performed stably and reliably.

According to the eleventh aspect of the present invention, since each pressure chamber can be closed as in the case of the intermediate control, the locking action of each plunger can be obtained, and the hydraulic pressure from the fluid pump at restart can be obtained. The forward / reverse rotation of the rotation member or the like due to the positive / negative torque fluctuation until the rise can be reliably restricted. As a result, it is possible to prevent occurrence of a tapping sound or the like between each plunger tip surface and each contact surface.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line AA of FIG.

FIG. 2 is a sectional view taken along line BB of FIG. 1 showing one embodiment of the present invention.

FIG. 3 is a schematic diagram of a hydraulic circuit provided in the embodiment.

FIG. 4 is an explanatory diagram of an operation of a hydraulic circuit during advance control.

FIG. 5 is an explanatory diagram of an operation at the time of advance angle control.

FIG. 6 is an explanatory diagram of the operation at the time of the most advanced angle control.

FIG. 7 is an explanatory diagram of an operation of a hydraulic circuit during retard side control.

FIG. 8 is an explanatory diagram of the operation at the time of retard control.

FIG. 9 is an explanatory diagram of the operation at the time of the most retarded side control.

FIG. 10 is an explanatory diagram of a hydraulic circuit when the engine is restarted.

FIG. 11 is a characteristic diagram showing the operation time of this embodiment and a conventional example in comparison.

FIG. 12 is a characteristic diagram showing operation responsiveness at the time of advancing of the embodiment.

FIG. 13 is a schematic view of a main part of a conventional valve timing control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 ... Timing sprocket (rotating body) 22 ... Camshaft 25 ... Rotating member 26 ... Phase conversion means 31, 32 ... Contact surface 34, 35 ... Cylinder 36, 37 ... Retainer 38, 39 ... Plunger 40, 41 ... Pressure chamber 42 hydraulic circuit 43, 44 on-off valve 47, 48 check valve 49, 50 pressure receiving chamber 54 oil pump (fluid pump) 55, 56 supply passage 57, 58 discharge passage 60, 61 signal passage 62 … Space

Claims (11)

[Claims] A rotating body rotatably driven by a crankshaft of an engine, a camshaft provided rotatably relative to the rotating body and having a cam on an outer periphery for opening an engine valve, and the rotating body and cam And a phase converter for relatively rotating the shaft. The phase converter converts the relative rotation phase between the rotating body and the camshaft to control the opening / closing timing of the engine valve to be advanced or retarded. In the valve timing control device, the phase conversion unit is provided with a plurality of cylinders provided in the rotating body, and slidably provided in the respective cylinders in the forward and backward directions.
A plurality of plungers for relatively rotating the rotating body and the camshaft; and a plurality of plungers formed inside each of the plungers and relatively moving the respective plungers forward and backward by a liquid pressure supplied from a fluid pump via a check valve. A plurality of pressure chambers, a switching mechanism for switching supply and discharge passages for supplying and discharging hydraulic pressure to and from each of the pressure chambers in accordance with an engine operating state, and a rotating body for linearly moving a plunger sliding in the cylinder. A valve timing control device for an internal combustion engine, comprising: a conversion mechanism that converts the rotational motion into a rotational motion that relatively rotates a camshaft. 2. The valve timing control device for an internal combustion engine according to claim 1, wherein said switching mechanism is constituted by an on-off valve which operates by receiving a hydraulic pressure discharged from said fluid pump. 3. A rotating member fixed to the camshaft and provided with the cylinders at both ends in a radial direction of the camshaft; and a tip of each of the plungers provided on an inner surface of the rotating body. 3. The valve timing control device for an internal combustion engine according to claim 1, wherein the valve timing control device comprises a contact portion with which the portion contacts. 4. The valve timing control device for an internal combustion engine according to claim 3, wherein a contact surface of each contact portion is formed in a curved shape. 5. The valve timing control device for an internal combustion engine according to claim 1, wherein the check valve is provided near a pressure chamber in each plunger. 6. The valve timing control device for an internal combustion engine according to claim 1, wherein the switching mechanism is provided inside each of the plungers. 7. A signal passage for sending a signal hydraulic pressure for sliding an open / close valve in the other plunger in the opening direction of the discharge passage to the supply passage for supplying the hydraulic pressure to the pressure chamber of the one side plunger. 3. A method according to claim 2, wherein
7. The valve timing control device for an internal combustion engine according to any one of 6. 8. The valve timing control device for an internal combustion engine according to claim 7, wherein a part of the supply passage and the signal passage are constituted by a single continuous passage hole. 9. The apparatus according to claim 1, wherein a downstream end of the discharge passage communicates with a space formed between an outer surface of the rotating member and an inner surface of the rotating body. A valve timing control device for an internal combustion engine according to the above. 10. When controlling the relative rotation position of the rotating body and the camshaft to an intermediate position between the most advanced angle and the most retarded angle, supply to each pressure chamber via each on-off valve. The valve timing control device for an internal combustion engine according to any one of claims 1 to 9, wherein the exhaust passage is closed by the on-off valve while communicating with the passage. 11. The internal combustion engine according to claim 1, wherein when the engine is stopped, the check valve keeps the hydraulic pressure in the pressure chamber and the switching mechanism shuts off the discharge passage. Engine valve timing control device.