JPH07229408A - Valve timing control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the control responsiveness of a valve timing control device, and reduce the hammering by back lash. CONSTITUTION:In a variable valve timing control device, a ring gear 25 is moved in the axial direction of a cam shaft 1 by the energizing force of a fluid pressure from the pressurized fluid supplying source of an internal combustion engine, the driving force of a pulley is transmitted to the cam shaft by helical gears 25a, b, and the rotating phases of the pulley and the cam shaft are changed, whereby the opening and closing period of a valve is regulated. An OCV 44 switches the fluid to a pressure chamber, controls the stopping position of the ring gear, and has a sleeve 51, a spool 52, and a solenoid 53. The relation of lap margins delta1, delta2, delta3, delta4 among the sleeve 51 and valve bodies 63, 64 is represented by delta1=delta2>delta3=delta4. According to such a constitution, the discharge of the fluid from the pressure chamber is suppressed.

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 varying the opening / closing timing of an intake / exhaust valve of an internal combustion engine according to the operating state by moving the ring gear, and more specifically, it is formed before and after the ring gear. The present invention relates to a variable valve timing mechanism that supplies hydraulic pressure to each of the pressure chambers.

[0002]

2. Description of the Related Art Conventionally, as this type of technology, for example, the one disclosed in Japanese Patent Laid-Open No. 57-212310 is known.

In this valve timing control device, a relative rotation control device for controlling the rotation of the cam shaft is provided between the input gear and the cam shaft. In this relative rotation control device, a slider is provided so as to be capable of reciprocating in the axial direction, and at least one of the teeth provided on the inner and outer circumferences of the slider is formed in a spline shape. The rotation of the input gear is transmitted to the camshaft via this slider. A piston is connected to the slider, and pressure chambers are formed in front of and behind the piston, respectively. Two hydraulic circuits for supplying hydraulic pressure to the respective pressure chambers are formed. When the hydraulic pressure is supplied to the pressure chambers by this hydraulic circuit, the slider moves in the axial direction of the cam shaft due to the pressure balance between the pressure chambers. To do. Therefore, the camshaft rotates relative to the input gear, and the opening / closing timing of the intake / exhaust valve is controlled.

Here, when the opening / closing timing of the intake / exhaust valve is controlled to an intermediate position, the hydraulic pressure is supplied to one pressure chamber and at the same time the hydraulic pressure of the other pressure chamber is released so that the position is controlled. For this reason, the slider may suddenly start moving, and a tapping sound may be generated by the teeth of the slider. Further, since the hydraulic pressure is released quickly, air may be mixed into the compression chamber on the side where the hydraulic pressure is released, and a hydraulic response delay may occur when the advance / retard control is performed next. Further, when the cam torque fluctuates while being held at the intermediate position, there is a problem that the camshaft tries to rotate and a tapping sound is generated due to backlash.

In order to solve the hitting sound due to the backlash, a valve timing control device having a structure in which a drag is generated between the timing pulley and the cam shaft is disclosed in Japanese Patent Application Laid-Open No. 4-183907. This valve timing control device is provided with an elastic member that presses one end of a rotating body of a timing pulley driven by an engine against the end of a camshaft facing the one end in the thrust direction. Therefore, abrupt forward / reverse relative rotation between the cam shaft and the timing pulley due to fluctuations in the rotational torque of the cam shaft is suppressed, and collision striking noise between the teeth of the ring gear and the timing pulley can be reduced.

[0006]

However, in the above-mentioned prior art, one end of the timing pulley is always in pressure contact with the end of the camshaft by the elastic member, which causes a delay in valve timing control and deteriorates responsiveness. I will let you. Further, since an elastic member is additionally provided, there is a problem that the structure becomes complicated and it is not easy to downsize the valve timing control device.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a high control response and a small size.
Moreover, it is another object of the present invention to provide a valve timing control device for an internal combustion engine, which can reduce the hitting sound due to backlash.

[0008]

In order to achieve the above object, according to the present invention, as shown in FIG. 1, a pulley M2 provided on the outer periphery of a camshaft M1 for driving a valve of an internal combustion engine, and the camshaft. And a cylindrical ring gear M3 which is interposed between the pulleys and has teeth on the inner and outer peripheral surfaces, and at least one of which is a helical tooth, and a fluid from the pressurized fluid supply source M4 is provided at both ends of the ring gear M3. A pair of control passages M7, M8 for guiding the fluid to one of the pressure chambers M5, M6, causing the fluid to act on one end side of the ring gear M3, and discharging from the other, and the control passage M7, Switching means M9 capable of switching M8 to communicate with either the introduction side through which the fluid is introduced into the pressure chambers M5 and M6 or the discharge side through which the fluid is discharged from the pressure chambers M6 and M5. Provided, by the biasing force of the fluid pressure from the source of pressurized fluid M4, the ring gear M3 camshaft M
1 is moved in the axial direction, the driving force of the pulley M2 is transmitted to the camshaft M1 by helical teeth, and the rotational phase of the pulley M2 and the camshaft M1 is changed to adjust the opening / closing timing of the valve. The gist of the valve timing control device is to provide a suppressing means M10 for suppressing the discharge of fluid from the other pressure chamber M6, M5 when the fluid is introduced into the one pressure chamber M5, M6.

[0009]

According to the above construction, as shown in FIG. 1, the ring gear M3 is moved in the axial direction of the camshaft M1 by the urging force of the fluid pressure from the pressurized fluid supply source M4. The driving force of the pulley M2 is transmitted to the camshaft M1 by helical teeth, and the rotational phase of the pulley M2 and the camshaft M1 is changed, so that the opening / closing timing of the valve is adjusted. The suppression means M10 suppresses the discharge of the fluid from the pressure chambers M6, M5 when the fluid is introduced into one of the pressure chambers M5, M6, so that the internal pressure of the pressure chambers M5, M6 rises. Due to the internal pressure of the pressure chambers M5, M6, the camshaft M
The rotational drag between 1 and the pulley M2 is increased.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment embodying a valve timing control device according to the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a variable valve timing actuator (VVT) mounted on an engine in this embodiment.
FIG. 3 is a cross-sectional view mainly showing a valve timing control device including an actuator). An engine (not shown) is provided with a camshaft 1 for driving an intake valve or an exhaust valve. The journal 2 of the camshaft 1 is rotatably supported between the bearing portion 4 of the cylinder head 3 and the bearing cap 5. The journal 2 has two journal grooves 6 and 7.
Is formed so as to extend along the outer periphery of the. Further, the cylinder head 3 is provided with a first head oil passage 8 and a second head oil passage 9 which form a control passage for supplying lubricating oil to the respective journal grooves 6, 7 and the journal 2. ing.

One ends of the first head oil passage 8 and the second head oil passage 9 are connected to an oil control valve (hereinafter, simply referred to as OCV) 44 which constitutes a switching means and a suppressing means. This OCV44 is an oil filter 4
3, oil pump 41, and oil strainer 45
It is connected to the oil pan 42 via. Also, OC
The V44 includes an electronic control unit (hereinafter referred to as an ECU) 71.
Are connected. Various sensors are connected to the ECU 71, and the OCV 44 is controlled by detecting the state of the engine at that time based on the detection signal of the sensor.

The oil pump 41 is drivingly connected to the engine and pumps and discharges lubricating oil in conjunction with the operation of the engine. Then, by driving the oil pump 41, the oil pan 42 moves to the oil strainer 45.
Lubricating oil is pumped through. After the lubricating oil passes through the oil filter 43, the operation of the OCV 44 causes
It is supplied with a predetermined pressure to the head oil passages 8 and 9 and then to the journal grooves 6 and 7 and the journal 2. Here, the supply of the lubricating oil to the head oil passages 8 and 9 can be arbitrarily adjusted by the OCV 44. The detailed configuration of the OCV 44 will be described later.

Next, the mechanism for adjusting the valve timing, that is, the VVT actuator 48 will be described. A timing pulley housing 10 that constitutes a pulley is provided at the tip of the camshaft 1. This timing pulley housing 10 has a pulley body 11
And a cover 12 assembled so as to cover one side surface of the pulley body 11 and the tip end portion of the cam shaft 1. The pulley main body 11 has a substantially disc shape, a plurality of outer teeth 13 are formed on the outer periphery thereof, and a boss 14 is formed at the center thereof. The pulley body 11 is mounted by the boss 14 so as to be rotatable relative to the cam shaft 1.
A timing belt 15 is attached to the outer teeth 13, and the timing pulley housing 10 is drivingly connected to a crankshaft (not shown) of the engine through the belt 15.

On the other hand, the cover 12 has a bottomed cylindrical shape, a flange 16 is formed on the outer periphery thereof, and a communication hole 17 is formed at the center of the bottom. Further, a plurality of inner teeth 12a are formed on the inner circumference of the cover 12. The cover 12 is fixed to one side surface of the pulley body 11 by a plurality of bolts 18 and pins 19 at its flange 16. A lid 20 is detachably attached to the communication hole 17. The space surrounded by the pulley body 11 and the cover 12 serves as a housing space 21 formed inside the timing pulley housing 10.

In this housing space 21, at the tip of the camshaft 1, a bottomed cylindrical inner cap 22 is tightened by a hollow bolt 23 and is prevented from rotating by a pin 24. The peripheral wall 22a of the inner cap 22 is mounted so as to include the boss 14 of the pulley body 11, and both 11 and 12 are relatively rotatable. Further, the thrust surface 11a of the pulley body 11 and the end surface 22b of the inner cap 22 can slide with the relative rotation. Further, a plurality of outer teeth 22b are formed on the outer periphery of the peripheral wall 22a of the inner cap 22.

A ring gear 25 is interposed between the timing pulley housing 10 and the camshaft 1, and the ring gear 25 connects the two 10, 10. That is, the ring gear 25 has an annular shape and is housed in the housing space 21 of the timing pulley housing 10 so as to be capable of reciprocating along the axial direction of the camshaft 1. This ring gear 25 has a plurality of teeth 25 provided on its inner and outer circumferences.
Both a and 25b have helical teeth, and can move relative to the camshaft 1 by moving in the axial direction. The teeth 25a on the inner circumference of the ring gear 25 mesh with the outer teeth 22b of the inner cap 22, and the teeth 25b on the outer circumference of the ring gear 25 mesh with the inner teeth 12a of the cover 12. Therefore, when the timing pulley housing 10 is rotationally driven, the timing pulley housing 10 and the inner cap 22 connected by the ring gear 25 are connected.
Are rotated integrally with each other, and the camshaft 1 is also rotated integrally with the timing pulley housing 10.

In the accommodation space 21, a first hydraulic chamber 26 is formed between one axial end of the ring gear 25 and the bottom wall of the cover 12. Similarly, in the accommodation space 21, a second hydraulic chamber 27 is formed between the other axial end of the ring gear 25 and the pulley body 11.

Here, in order to supply lubricating oil to the first hydraulic chamber 26 to generate hydraulic pressure, the camshaft 1 is formed with a first shaft oil passage 28 extending along the center thereof. The end of the shaft oil passage 28 is a hollow bolt 2
The first hydraulic chamber 26 communicates with the third central hole 23a. Further, the base end side of the shaft oil passage 28 communicates with the journal groove 6 through an oil hole 29 extending in the radial direction of the camshaft 1.

On the other hand, in order to supply lubricating oil to the second hydraulic chamber 27 to generate hydraulic pressure, the camshaft 1 has a second shaft oil passage 3 extending parallel to the first shaft oil passage 28.
0 is formed. Further, at the position near the tip of the camshaft 1, one circumferential groove 31 extending along the outer circumference thereof is formed. A part of the circumferential groove 31 communicates with the second shaft oil passage 30. Further, an oil hole 32 that connects the circumferential groove 31 and the second hydraulic chamber 27 is formed in a part of the boss 14 of the pulley body 11. Further, the base end side of the second shaft oil passage 30 communicates with the other journal groove 7. In addition, between the ring gear 25 and the pulley body 11 in the second hydraulic chamber 27, as a biasing means for biasing the ring gear 25 to return to the initial position (retard position) shown in FIG. The spring 33 is mounted.

Next, the OCV 44 described above will be described. The OCV 44 selectively opens and closes the first head oil passage 8 and the second head oil passage 9 to control the stop position of the ring gear 25. As shown in FIG. 3, OCV4
4 includes a sleeve 51, a spool 52, and a solenoid 53 as a driving unit that drives the spool 52. A supply port 54, a first discharge port 55, a second discharge port 56, a first drain port 57 and a second drain port 58 are formed in the sleeve 51. The supply port 54 is connected to the oil pump 41. Further, the first discharge port 55 is connected to the first head oil passage 8, and the second discharge port 56 is connected to the second head oil passage 9. Further, the first drain port 57 and the second drain port 58 are connected to the oil pan 42.
It is connected to the.

Inside the sleeve 51, a spool 52 having a substantially cylindrical shape is disposed so as to be slidable in the left-right direction in the drawing. A solenoid 53 is built in the latter half of the OCV 44 (right side in the figure), and the spool 52 is connected to the solenoid 53. Solenoid 53 is E
The spool 52 is duty-controlled by the CU 71.
Moves in the sleeve 51 according to the duty ratio.

Valve bodies 63 and 64 are formed on the outer circumference of the spool 52 by three annular recesses 59, 60 and 61. The axial lengths of the valve bodies 63 and 64 are set to be larger than the axial lengths of the openings of the first discharge port 55 and the second discharge port 56, respectively. Therefore, the openings of the first discharge port 55 and the second discharge port 56 can be closed by the valve bodies 63 and 64.

As shown in FIG. 3A, the spool 52 is arranged at the center of the sleeve 51, and the first discharge port 5
5. In the state where both openings of the second discharge port 56 are closed, the lap margin δ between the sleeve 51 and the valve bodies 63 and 64
The relationship among 1, δ2, δ3, δ4 is δ1 = δ2> δ3 = δ
It is represented by 4. Therefore, when the spool 52 is moved to the left in the figure by the solenoid 53, first, the first discharge port 55 is opened, and after a predetermined delay time, the second discharge port 56 is opened. Conversely, when the spool 52 is moved to the right in the figure by the solenoid 53, first, the second discharge port 56 is opened, and after a predetermined delay time,
The first discharge port 55 is opened. In this way, the lap margins δ1, δ2, δ between the sleeve 51 and the valve bodies 63, 64
The suppressing means is constituted by the spool 52 formed such that 3,3 has a relationship of δ1 = δ2> δ3 = δ4.

Next, the operation of the valve timing control device constructed as described above will be described in detail. As shown in FIG. 2, when the ring gear 25 is held to the left in the figure, the spool 52 of the OCV 44 is held in the state shown in FIG. In this case, the solenoid 53 is EC
It is excited by U71 with an excitation voltage of 50% duty ratio (ON / OFF ratio of the excitation voltage), and both discharge ports 55 and 56 are closed.

When the duty ratio of the exciting voltage for exciting the solenoid 53 is increased from this state, the spool 52 moves leftward in the figure against the biasing force of the spring 62, as shown in FIG. 3 (b). , The first discharge port 55 and the supply port 54 are communicated with each other, and the lubricating oil is supplied to the first head oil passage 8. Lubricating oil is journal groove 6, oil hole 29, first
Shaft oil passage 28 and the central hole 23a of the hollow bolt 23
Is supplied to the first hydraulic chamber 26 through. Therefore, the hydraulic pressure generated in the first hydraulic chamber 26 is applied to one end of the ring gear 25, and the ring gear 25 resists the biasing force of the spring 33 and the hydraulic pressure of the second hydraulic chamber 27 in the axial direction. Is pushed to. However, the sleeve 51 and the valve body 6
In the lap margins δ2 and δ3 with 3, 64, δ2> δ3
Therefore, the second discharge port 56 is not yet opened, and the lubricating oil is not discharged, so that the movement of the ring gear 25 is suppressed.

When the duty ratio is further increased, the spool 52 is held at the position shown in FIG.
The discharge port 56 and the second drain port 58 are communicated with each other. Then, the second head oil passage 9 is moved to the oil pan 42.
Is released to the oil hole 3 from the second hydraulic chamber 27.
2, peripheral groove 31, second shaft oil passage 30, journal groove 7, second head oil passage 9 and second drain port 58
Through the oil pan. Therefore, the hydraulic pressure in the second hydraulic chamber 27 decreases, and the hydraulic pressure in the first hydraulic chamber 26 causes the ring gear 25 to move in the axial direction against the biasing force of the spring 33.

When the ring gear 25 moves in the axial direction, helical teeth 25 provided on the inner and outer circumferences of the ring gear 25.
The ring gear 25 is rotated by the engagement of the a and 25b with the outer teeth 22b of the inner cap 22 and the inner teeth 12a of the cover 12, and the camshaft 1 is twisted. As a result, the camshaft 1 and the timing pulley housing 1
The relative position in the rotation direction with respect to 0 is changed, and the operation timing of the intake valve or the exhaust valve is advanced.

When the ring gear 25 reaches the valve timing position of the intermediate phase, the duty ratio of the exciting voltage for exciting the solenoid 53 is returned to 50% again.
Then, the spool 52 causes the spring 62, which is a biasing means, to
The urging force moves to the position shown in FIG. 3 (b) by the urging force, and first, the communication between the second discharge port 56 and the second drain port 58 is blocked. In this state, the first discharge port 55 is in communication with the supply port 54, and
The hydraulic pressure in the hydraulic chamber 26 is increasing. On the other hand, since the lubricating oil remains in the second hydraulic chamber 27, the second hydraulic chamber 2
The hydraulic pressure of 7 also rises together with the first hydraulic chamber 26. Further, the spool 25 moves to the position shown in FIG. 3A, and both discharge ports 55 and 56 are closed. Therefore, the hydraulic pressure in the first and second hydraulic chambers 26, 27 is maintained in a high state. At this time, the force due to the hydraulic pressure on the first pressure chamber 26 side (the product of the pressure of the first pressure chamber 26 and the pressure receiving area A1)
Is the force due to the hydraulic pressure on the second pressure chamber 27 side (the product of the pressure of the second pressure chamber 27 and the pressure receiving area A1), the urging force of the spring 33, and the cam drive torque from the helical teeth 25a, 25b. Balanced with power. Furthermore, since the communication between the second discharge port 56 and the second drain port 58 is first blocked, there is no risk that air will be mixed into the second hydraulic chamber 27.

On the other hand, when the duty ratio of the excitation voltage of the solenoid 53 is reduced when the ring gear 25 is in the most advanced angle state, the spool 52 is changed from the state shown in FIG. Move to the right in the figure. Then, the spool 52 moves to the position shown in FIG. 4B, and the second discharge port 56 and the supply port 54 are communicated with each other. When the lubricating oil is supplied to the second head oil passage 9,
Lubricating oil is supplied to the second hydraulic chamber 27 through the journal groove 7, the second shaft oil passage 30, the peripheral groove 31, and the oil hole 32. Therefore, the hydraulic pressure generated in the second hydraulic chamber 27 is applied to one end of the ring gear 25, and the ring gear 25 acts on the shaft against the hydraulic pressure of the first hydraulic chamber 26 together with the urging force of the spring 33. Is pressed in the direction. However, the lap margin δ1, between the sleeve 51 and the valve bodies 63, 64
At δ4, since δ1> δ4, the first discharge port 55 is not yet opened, and the lubricating oil is not discharged, so that the movement of the ring gear 25 is suppressed.

Further, when the duty ratio of the exciting voltage is reduced, the spool 52 is held at the position shown in FIG. 4C, and the first discharge port 55 and the first drain port 5 are held.
7 is communicated with. Then, the first head oil passage 8 is opened to the oil pan 42, and the lubricating oil flows from the first hydraulic chamber 26 to the center hole 23a of the hollow bolt 23, the first shaft oil passage 28, the oil hole 29, and the journal. The oil is discharged to the oil pan through the groove 6, the first head oil passage 8 and the first drain port 57. Therefore, the hydraulic pressure in the first hydraulic chamber 26 decreases, and the ring gear 25 moves in the axial direction by the hydraulic pressure in the second hydraulic chamber 27 and the biasing force of the spring 33.

When the ring gear 25 moves in the axial direction, helical teeth 25 provided on the inner and outer circumferences of the ring gear 25.
The ring gear 25 is rotated by the engagement of the a and 25b with the outer teeth 22b of the inner cap 22 and the inner teeth 12a of the cover 12, and the camshaft 1 is twisted. As a result, the camshaft 1 and the timing pulley housing 1
The relative position with respect to 0 in the rotation direction is changed, and the operation timing of the intake valve or the exhaust valve is retarded.

When the ring gear 25 reaches the intermediate phase position, the duty ratio of the exciting voltage of the solenoid 53 is returned to 50%. Then, the spool 52 resists the urging force of the spring 62 and moves to the left in the drawing, as shown in FIG.
To the first discharge port 55 and the first
The communication with the drain port 57 is blocked. In this state, the second discharge port 56 is in communication with the supply port 54, and the hydraulic pressure in the second hydraulic chamber 27 is rising. Furthermore, since the lubricating oil remains in the first hydraulic chamber 26, the hydraulic pressure in the first hydraulic chamber 26 also rises together with the second hydraulic chamber 27. After that, the spool 25 moves to the position shown in FIG. 4A, and both discharge ports 55 and 56 are closed.
Therefore, the hydraulic pressure in the first and second hydraulic chambers 26, 27 is maintained in a high state. At this time, first
Since the communication between the discharge port 55 and the first drain port 57 is cut off, there is no possibility that air will be mixed into the first hydraulic chamber 26.

As described above, in both cases where the ring gear 25 moves in the advance direction and the retard direction and is controlled to the intermediate phase, the first and second hydraulic chambers 26, 26
The hydraulic pressure in 27 is kept high. At this time,
Thrust force is generated in the VVT actuator 48 shown in FIG. That is, a thrust force equal to the product of the pressure in the first compression chamber 26 and the pressure receiving area A2 acts between the thrust surface 11a of the pulley body 11 and the end surface 22c of the inner cap 22. Since the pressure in the first hydraulic chamber 26 is high, the thrust force becomes large, and a relatively large sliding friction resistance is generated between the thrust surface 11a and the end surface 22c of the inner cap 22.

The camshaft 1 tries to rapidly rotate forward and backward with respect to the pulley body 11 by the driving force of the engine and the spring reaction force of a valve spring (not shown), but the thrust surface 11a and the end surface 22c of the inner cap 22 are rotated. Rapid forward / reverse rotation is sufficiently suppressed by the sliding frictional resistance with. Therefore, while the ring gear 25 is stopped, it is possible to reduce the tapping sound due to backlash between the helical teeth 25a and 25b of the ring gear 25, the outer teeth 22b of the inner cap 22 and the inner teeth 12a of the cover 12.

Further, while the ring gear 25 is moving, one end of the ring gear 25 is pressed by the hydraulic pressure in the first or second hydraulic chambers 26 and 27, so that the helical teeth 25a and 25b have inner caps. It is pressed by the outer teeth 22b of 22 and the inner teeth 12a of the cover 12, and a tapping sound due to backlash is not generated.

As described above in detail, the lap margins δ1, δ2, δ3, δ4 between the sleeve 51 and the valve bodies 63, 64 are δ1.
= Δ2> δ3 = δ4, the spool 52 is formed so as to have the relationship of the restraining means.
The hydraulic pressure in the hydraulic chambers 26, 27 is maintained at a high level. Therefore, the thrust force is increased, and a relatively large sliding frictional resistance is generated between the thrust surface 11a and the end surface 22c of the inner cap 22. Therefore, the rotation drag can be generated without making any change on the VVT actuator side, and the tapping sound resulting from the backlash can be reduced. Further, first, the communication between the first discharge port 55 and the first drain port 57 is blocked, that is, the discharge side of the lubricating oil is blocked first, so that air is mixed into the first hydraulic chamber 26. There is no danger of Therefore, damping of the ring gear 25 is prevented and stabilization is possible, and a hydraulic response delay at the time of the next control is prevented, and the control response is improved.

Next, a second embodiment of the valve timing control device according to the present invention will be described. In the following, the same components as those in the first embodiment will be denoted by the same reference numerals in the drawings and will not be described.

As shown in FIG. 5, the first head oil passage 8 and the second head oil passage 9 of the VVT actuator 48 are
They are connected to the discharge ports of the first and second three-way switching valves 65 and 66, which are electromagnetic valves, respectively. Both 3-way switching valve 6
The supply ports 5 and 66 are connected to the oil pan 42 via an oil filter 43, an oil pump 41, and an oil strainer 45. Furthermore, both 3-way switching valves 65, 6
The drain port 6 is connected to the oil pan 42 via drain pipes 67 and 68.

The three-way switching valves 65 and 66 are connected to the ECU 72 and can be switched to respective positions a, b and c by the control of the ECU 72. 3-way switching valve 65,6
When 6 is controlled to the position b shown in FIG. 5, the discharge port, the supply port and the drain port are shut off. Also,
When the three-way switching valves 65 and 66 are controlled to the position a, the discharge port and the drain port are communicated with each other, and when the three-way switching valves 65 and 66 are controlled to the position c, the discharge port and the supply port are communicated with each other.

Next, the operation of the valve timing control device constructed as described above will be described. The ring gear 2
Since the operation of moving 5 to control the valve timing to the advance side or the retard side is the same as that of the first embodiment, only based on the flow chart shown in FIG. Explain. The processing operation of this flowchart is executed by a program stored in the ECU 72.

When the ring gear 25 is moved to the advance side from the state where it is held at the most retarded position to the left of the housing space 21 (in FIG. 2) (a), first the first three-way switching valve 65 is used. Is c
It is switched to the position (step 100). Then, the lubricating oil is supplied to the first hydraulic chamber 26, the hydraulic pressure is applied to one end of the ring gear 25, and the ring gear 25 resists the urging force of the spring 33 and the hydraulic pressure of the second hydraulic chamber 27. Is pressed in the direction. However, the second three-way switching valve 66 is still held in the b position, and the second hydraulic chamber 2
Since the lubricating oil of No. 7 is not discharged, the movement of the ring gear 25 is suppressed. Then, after a predetermined delay time (step 101), the three-way switching valve 66 is switched to the a position (step 102), and the lubricating oil in the second hydraulic chamber 27 is discharged, so that the ring gear 25 advances. Move to the side.

When the ring gear 25 reaches the intermediate phase position (step 103), the three-way switching valve 66 is switched to the b position (step 104). At this time, since the three-way switching valve 65 is held in the c position, the lubricating oil is continuously supplied to the first hydraulic chamber 26, and the internal pressures of the first and second hydraulic chambers 26 and 27 are increased. Furthermore, after the predetermined delay time (step 105), when the three-way switching valve 65 is switched to the b position (step 106), the internal pressures of the first and second hydraulic chambers 26, 27 are kept high. .

On the other hand, when the ring gear 25 is moved to the retard side, the second three-way switching valve 66 is first switched to the c position (step 200). Then, the second hydraulic chamber 27
The lubricating oil is supplied to the ring gear 25, and the oil pressure is applied to one end of the ring gear 25.
Along with the urging force of the first hydraulic chamber 26, it is pressed in the axial direction against the hydraulic pressure in the first hydraulic chamber 26. However, since the first three-way switching valve 65 is held in the b position and the lubricating oil in the first hydraulic chamber 26 is not discharged, the movement of the ring gear 25 is suppressed. Then, after a predetermined delay time (step 201),
The three-way switching valve 65 is switched to the a position (step 20
2) As the lubricating oil in the first hydraulic chamber 26 is discharged, the ring gear 25 moves to the retard side.

When the ring gear 25 reaches the intermediate phase position (step 203), the three-way switching valve 65 is switched to the b position (step 204). At this time, since the three-way switching valve 66 is held in the c position, the lubricating oil is continuously supplied to the second hydraulic chamber 27, and the internal pressures of the first and second hydraulic chambers 26, 27 are increased. Furthermore, after the predetermined delay time (step 205), when the three-way switching valve 66 is switched to the b position (step 206), the internal pressures of the first and second hydraulic chambers 26 and 27 are maintained in a high state. .

In this processing operation, step 101,
201 is equivalent to the suppressing means at the time of starting the ring gear 25, and steps 106 and 206 are equivalent to the suppressing means at the time of stop.

As described above, the first and second hydraulic chambers 2
Even when the hydraulic pressures of 6 and 27 are controlled by the two 3-way switching valves 65 and 66, the same effect as that of the first embodiment can be obtained because the suppressing means is constituted by the ECU 72.

The present invention is not limited to the above-described embodiment, but may be implemented as follows with a part of the configuration appropriately changed without departing from the spirit of the invention. (1) In the first embodiment, the OCV 44 or the three-way switching valves 65 and 66 are used as the suppressing means, but instead,
A fluid resistance means such as an orifice or a fluid restriction means may be provided in the drain pipe.

(2) In the second embodiment, the ECU 72 constitutes the suppressing means, but instead, as the three-way switching valve, a switching valve having a characteristic that switching from the b position to the a position is slower than other operations is performed. May be used.

The technical ideas other than the claims that can be understood from the above-described embodiments will be described below along with their effects. (I) The valve timing control device according to claim 1, wherein instead of the suppressing means, another opening / closing means is provided with another suppressing means for introducing the fluid into one pressure chamber and then discharging the fluid from the other pressure chamber. According to this configuration, the start of movement of the ring gear 25 becomes gentle, and the tapping sound of the helical teeth is reduced.

(Ii) The switching means and the opening / closing means are constituted by a three-position switching valve for moving a spool having a valve element in the sleeve to switch and open / close the passage, and the restraining means is a sleeve and a valve element. The valve timing control device according to claim 1, wherein the valve timing control device is constituted by a lap margin with With this configuration, it is possible to construct a very simple suppressing means by the lap margin of the sleeve and the valve body, and it is possible to implement at an extremely low cost. (Iii) A pulley provided on the outer circumference of a valve driving camshaft of an internal combustion engine, and a pulley interposed between the camshaft and the pulley, having teeth on the inner and outer peripheral surfaces, and at least one of which is a helical tooth. For guiding the fluid from the cylindrical ring gear and the pressurized fluid supply source to one of the pressure chambers provided at both ends of the ring gear, causing the fluid to act on one end side of the ring gear, and discharging from the other A pair of control passages; switching means for switching the control passages so as to communicate with either the introduction side through which fluid is introduced into the pressure chamber or the discharge side through which fluid is discharged from the pressure chamber; An opening / closing means for opening / closing the control passage,
The ring gear is moved in the axial direction of the camshaft by the urging force of the fluid pressure from the pressurized fluid supply source, the driving force of the pulley is transmitted to the camshaft by helical teeth, and the rotation phase of the pulley and camshaft is changed. In the variable valve timing control device adapted to adjust the opening / closing timing of the valve, the opening / closing means closes the control passage communicated with the discharge side and then suppresses the closing of the control passage communicated with the introduction side. A valve timing control device for an internal combustion engine, which is provided with a means. With this configuration, it is possible to obtain the same effect as that of the above embodiment.

In the above embodiment, the internal combustion engine includes a gasoline engine and a diesel engine.

[0053]

As described above in detail, according to the present invention, it is possible to provide a valve timing control device for an internal combustion engine, which has a high control response, is small in size, and can reduce the tapping sound due to backlash. Produce the effect.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a valve timing control device according to a first embodiment of the present invention.

FIG. 3A is a state where both the first and second discharge ports are closed, FIG. 3B is a state where the first discharge port is open and the second discharge port is closed, and FIG. FIG. 3 is a cross-sectional view showing the oil control valve in FIG. 2 in which both the first and second discharge ports are open.

FIG. 4A is a state in which both the first and second discharge ports are closed, FIG. 4B is a state in which the second discharge port is open and the first discharge port is in a closed state, and FIG. FIG. 3 is a cross-sectional view showing the oil control valve in FIG. 2 in which both the first and second discharge ports are open.

FIG. 5 is a schematic configuration diagram showing a valve timing control device according to a second embodiment of the present invention.

6 is a diagram showing the valve timing control device of FIG.
(A) is for moving the ring gear to the advance side,
(B) is a flowchart showing a processing operation when the ring gear is moved to the retard side.

[Explanation of symbols]

1 ... Camshaft, 8 ... (constituting control passage) 1st
Head oil passage, 9 ... (forms a control passage), second head oil passage, 10 ... (forms a pulley) timing pulley housing, 25 ... ring gear, 26 ... first hydraulic chamber, 27 ... second Hydraulic chamber 28, first shaft oil passage 28 (constituting a control passage), 30 ... second shaft oil passage 44 (constituting a control passage) O (switching means) O
CV, 51 ... (constituting suppression means) Spool, 65,
66 ... (three-way switching valve that constitutes the switching means), 72 ... (ECU that constitutes the suppressing means).

Claims (1)

[Claims] 1. A pulley provided on the outer circumference of a valve-driving cam shaft of an internal combustion engine, and a pulley interposed between the cam shaft and the pulley,
A cylindrical ring gear having teeth on the inner and outer peripheral surfaces, and at least one of which is a helical tooth, and a fluid from a pressurized fluid supply source are guided to one of the pressure chambers provided at both ends of the ring gear, A pair of control passages for causing a fluid to act on one end side of the ring gear and discharging it from the other side, an introduction side where the fluid is introduced into the pressure chamber, and a discharge passage discharged from the pressure chamber through the control passage. And a switching means that is switchable so as to communicate with either side, and the ring gear is moved in the axial direction of the camshaft by the urging force of the fluid pressure from the pressurized fluid supply source to drive the pulley. In the variable valve timing control device that transmits to the camshaft with helical teeth and changes the rotational phase of the pulley and the camshaft to adjust the opening / closing timing of the valve, A valve timing control device for an internal combustion engine, comprising a suppressing means for suppressing discharge of fluid from the other pressure chamber when introducing the fluid into the force chamber.