JP2003278512A - Valve opening/closing timing control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a valve opening/closing timing control device which is small-sized and has a simple structure without the necessity of a seal member. <P>SOLUTION: The width of a receiving groove part 23 is set wider than that of a retraction groove part 34. A clearance d between a rotation transmitting member 3 for forming a hydraulic fluid chamber R0 and the sliding contact part of a rotary member 2 is set to 150 μm or less. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

The present invention relates to a valve opening / closing timing control device for controlling the opening / closing timing of intake / exhaust valves of an internal combustion engine.

[0002]

2. Description of the Related Art A valve opening / closing timing control device of this type is known, for example, as disclosed in Japanese Patent Laid-Open No. 2001-3716.

This device comprises a rotating member integrally connected to a valve-opening / closing camshaft, and a rotation transmitting member assembled to the rotating member so as to be relatively rotatable within a predetermined range and transmitting rotational power from a crankshaft. Is equipped with. The vane attached to the rotary member divides the oil chamber formed in the rotation transmission member into an advance oil chamber and a retard oil chamber. Then, the first for supplying and discharging the hydraulic oil to and from the advance and retard oil chambers, respectively.
The second hydraulic oil passage is provided, and the rotary member and the rotation transmitting member are rotated with respect to each other by supplying and discharging the hydraulic oil to and from each oil chamber. Further, the rotation transmitting member is formed with a retracting portion for accommodating the lock member biased toward the rotating member by the spring, and the rotating member is locked when the relative position with the rotation transmitting member reaches a predetermined position. A receiving portion is formed in which the head of the is inserted. The locking member and the receiving portion are fitted to each other so that the rotation transmitting member can be locked with respect to the rotating member.

The working hydraulic chamber of such a valve opening / closing timing control device is not always filled with the working oil, and usually air is mixed. For this reason, when the rotation transmission member and the lock member that allows the rotation member to rotate relative to each other are not fitted in the receiving portion, the rotation transmission member and the rotation member vibrate with each other due to load fluctuation of the camshaft. Rotate. In such a state, when the rotation transmission member and the rotation member come to a predetermined relative position, the head of the lock member can be fitted into the receiving portion. Is shaped into a tapered shape.

When a hydraulic pressure for operating the lock member is applied, a seal member for ensuring the hydraulic pressure is arranged on both sides of the lock member.

[0006]

However, in the above-mentioned conventional configuration, the tip of the lock member formed in the tapered shape is not supported by the retreat, so the retreat needs to be set long. Further, since the retracting portion needs to have a function of sealing the hydraulic pressure on the side surface that slides with the lock member, the retracting portion needs to be set long. Therefore, there is a problem that the valve opening / closing timing control device becomes large in the radial direction. In addition, foreign matter is likely to intervene in the tapered portion, which may cause malfunction.

Further, in the above-mentioned conventional structure, it is necessary to dispose the seal members on both sides of the lock member, which causes an increase in the number of parts and complicates the structure. Therefore, there is a problem that the manufacturing cost increases.

Therefore, an object of the present invention is to realize a simple valve opening / closing timing control device which is small in size and does not require a seal member.

[0009]

A first technical means for solving the above technical problems is a valve opening / closing rotary member rotatably assembled to a cylinder head of an internal combustion engine, and A rotation transmission member, which is assembled to the rotation member so as to be relatively rotatable within a predetermined range, and which transmits rotation power from a crankshaft; a vane provided on either the rotation member or the rotation transmission member; and the rotation member. A hydraulic oil chamber formed between the vane and the rotation transmission member and divided into an advance oil chamber and a retard oil chamber by the vane, and hydraulic oil to the advance and retard oil chambers, respectively. First to supply and discharge
And a second hydraulic oil passage, a retraction groove portion formed in the rotation transmission member or the rotation member, for accommodating a plate-shaped locking member urged toward the rotation member or the rotation transmission member by a spring, A receiving groove portion formed on the rotating member or the rotation transmitting member, into which the head of the lock member is depressed when the relative positions of the rotating member and the rotation transmitting member match at a predetermined position, and hydraulic oil in the receiving portion. In a valve opening / closing timing control device that controls the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, including a third hydraulic oil passage for supplying / discharging, the width of the receiving groove is set to be wider than the width of the retracting groove. .

According to this means, even if the lock member is made up of a flat plate having a constant thickness up to the tip, the lock member can be fitted in the retracting groove portion.

Further, in order to solve the above-mentioned problems, the second technical means of the present invention has, in addition to the first means, a width of the lock member of 0.2 mm with respect to the width of the receiving groove portion.
To 0.8 mm.

According to this means, even if the lock member is constituted by a flat plate having a constant thickness up to the tip, the fitting into the retracting groove portion can be ensured with high reliability even under the condition that vibration is applied.

Further, a third technical means made to solve the above technical problem is a valve opening / closing rotary member rotatably assembled to a cylinder head of an internal combustion engine, and the rotary member. A rotation transmitting member assembled so as to be relatively rotatable within a predetermined range and transmitting rotational power from a crankshaft, a vane provided on either the rotating member or the rotation transmitting member, the rotating member and the rotation transmitting. A working hydraulic chamber formed between the member and a member, which is divided into an advance oil chamber and a retard oil chamber by the vane; and a hydraulic oil chamber for supplying and discharging the hydraulic oil to and from the advance and retard oil chambers, respectively. A first and a second hydraulic oil passage, a retraction groove portion formed in the rotation transmission member or the rotation member, for accommodating a lock member urged toward the rotation transmission member or the rotation transmission member by a spring, and A receiving groove portion formed on the rolling member or the rotation transmitting member, into which the head of the lock member is depressed when the relative positions of the rotating member and the rotation transmitting member are synchronized in a predetermined phase, and hydraulic oil in the receiving portion. In a valve opening / closing timing control device for controlling the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, which is provided with a third working oil passage for supplying / discharging, a rotation contact member for forming a working hydraulic chamber and a sliding contact of the rotating member. That is, the gap between the parts is set to 150 μm or less.

With this structure, the hydraulic pressure for operating the lock member can be maintained without the need for the seal member.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

A valve opening / closing timing control device 1 shown in FIGS. 1 to 6.
Has a rotary member 2 for opening and closing a valve, which includes a cam shaft 10 rotatably supported by a cylinder head 100 of an internal combustion engine, and an internal rotor 20 integrally assembled to the tip of the cam shaft 10. There is. Further, the valve opening / closing timing control device 1 has a rotation transmitting member 3 including an outer rotor 30, a front plate 40, and a rear plate 50, which is assembled so as to be capable of relative rotation with respect to the inner rotor 20 within a predetermined range. ing. A timing sprocket 31 is integrally provided on the outer circumference of the outer rotor 30.
Further, the torsion spring 60 assembled between the inner rotor 20 and the front plate 40, and the inner rotor 2
There are four vanes 70 attached to 0 and a lock plate 80 (FIG. 2) attached to the outer rotor 30.

As is well known, the rotational power is transmitted to the timing sprocket 31 from a crank shaft (not shown) through a crank sprocket and a timing chain in a clockwise direction shown as a cam shaft rotational direction in FIG.

The camshaft 10 has a known cam (not shown) for opening and closing an intake valve (not shown).
Inside 0, an advance passage (first hydraulic oil passage) 11 and a retard passage (second hydraulic oil passage) 12 extending in the axial direction of the camshaft 10 are provided. The advance passage 11 is connected to the first connection port 201 of the switching valve 200 through the radial passage 71 provided in the camshaft 10, the annular groove 14 and the connection passage 16 provided in the cylinder head 100.
The retard passage 12 is connected to the second connection port 202 of the switching valve 200 through the radial passage 72 provided in the camshaft 10, the annular groove 13 and the connection passage 15 provided in the cylinder head 100.

The switching valve 200 is a well-known type which moves the spool 204 against a spring (not shown) by energizing its solenoid 203. When not energized, the oil pump 205 driven by the internal combustion engine
The supply port 206 connected to the second connection port 202
And the first connection port 201 communicates with the discharge port 207. Further, when energized, as shown in FIG. 1, the supply port 206 communicates with the first connection port 201 and the second connection port 202 communicates with the discharge port 207. Therefore, when the switching valve 200 is not energized, hydraulic oil (hydraulic pressure) is supplied to the retard passage 12 and when advanced, hydraulic oil (hydraulic pressure) is supplied to the advance passage 11. Switching valve 200
Is duty controlled to change the ratio of energization and de-energization per unit time. For example, if the duty ratio is controlled to 50%, the first and second ports 201 and 202 and the supply and discharge ports 206 and 207 will not be in communication with each other at all.

The inner rotor 20 is integrally fixed to the camshaft 10 by mounting bolts 91. Also,
As shown in FIG. 2, four vane grooves 21 and a receiving groove portion 22 are formed in the inner rotor 20. Further, the inner rotor 20 has three first hydraulic oil passages 23 extending in the radial direction, one hydraulic oil groove 23a, four second hydraulic oil passages 24, and a bottom of the receiving groove portion 22 for advancing the passage. A plurality of hydraulic oil passages each including one third hydraulic oil passage 25 communicating with the hydraulic fluid passage 11 are provided.

As shown in FIG. 2, a vane 70 is inserted into each vane groove 21, and the vane 70 is movable in four working hydraulic chambers R0 formed between an outer rotor 30 and an inner rotor 20, which will be described later. In addition, the working hydraulic chamber R0 is arranged so as to be divided into an advance oil chamber R1 and a retard oil chamber R2, respectively. A leaf spring 73 (FIG. 1) is arranged between the bottom of the vane groove 21 and the bottom surface of the vane 70 so that each of the four vanes 70 can be pushed radially into the vane groove 21. It is movably installed.

In the receiving groove portion 22, the state shown in FIG. 2, that is, when the relative positions of the camshaft 10 and the inner rotor 20 and the outer rotor 30 coincide with each other at a predetermined position (the most retarded position), as will be described later. A head portion 80d of a flat plate-shaped lock plate 80 movably attached to the outer rotor 30 is recessed by a predetermined amount to lock the rotation of the outer rotor 30 and the inner rotor 20. As shown in an enlarged view in FIG. 4, the thickness of the lock plate 80 is H, and the receiving groove portion 22 is
Let I be the width of. The rate of occurrence of a mistake in fitting the lock plate 80 into the receiving groove portion 22 due to the relationship between the width I and the thickness H, and the level of tapping sound generated when the lock plate 80 fits into the receiving groove portion 22 and then contacts each other. FIG. 6 shows the result of the examination of how the value changes. As can be seen from FIG. 6, when the thickness H is smaller than the width I by 0.2 mm or more, the fitting error is eliminated. However, the tapping level increases as the difference between the two increases. Therefore, it is understood that the selection may be made within a range that is less than the limit value of the allowable hammering sound and the difference between both is within 0.8 mm.

If the thickness of the lock plate 80 with respect to the width of the receiving groove portion 22 is set within this range, the lock plate 8
A good fitting characteristic and a low hammering sound level can be realized even if the portion having a constant thickness is formed without special processing such as a taper on the portion that is recessed into the zero receiving groove portion 22.

As shown in FIG. 2, in the four retarding oil chambers R2 formed by being divided by each vane 70, hydraulic oil (hydraulic pressure) is passed through the retarding passage 12 and the second operating oil passage 24. Is configured to be supplied and discharged. Further, hydraulic oil (hydraulic pressure) is supplied to and discharged from three of the four advance oil chambers R1 through the advance passage 11 and the first hydraulic oil passage 23. In the other advance angle oil chamber R1, the hydraulic oil (hydraulic pressure) from the third hydraulic oil passage 25 provided at the bottom of the receiving groove portion 22 with respect to the lock plate 80.
Is supplied and the lock plate 80 moves, the third
Hydraulic oil groove 2 that connects the hydraulic oil passage 25 and the advance oil chamber R1
It is configured to be able to supply and discharge via 3a.
In this way, the first hydraulic oil passage 23 is not provided for the advance oil chamber R1 at one location, and the third hydraulic oil passage 25 is also used, so that the structure of the hydraulic oil passage can be simplified and the manufacturing cost can be reduced. It is configured.

An annular front plate 40 and a rear plate 50 are joined to both sides of the outer rotor 30 in the axial direction, and are integrally assembled by four connecting bolts 92. Then, as described above, the outer rotor 30 and the inner rotor 20 are rotatable with respect to each other within an angular range defined by the vane 70 and the lock plate 80 moving in the working hydraulic chamber R0.

A timing sprocket 31 is integrally formed on the outer periphery of the axial end of the outer rotor 30 to which the rear plate 50 is joined. Further, on the inner circumference of the outer rotor 30, five convex portions 33 are formed so as to project inward in the radial direction. These convex portions 33
The inner peripheral surface of is in sliding contact with the outer peripheral surface of the inner rotor 20, and the outer rotor 30 is rotatably supported by the inner rotor 20. Of the five convex portions 33, a retracting groove portion 34 that accommodates the lock plate 80 between the two convex portions 33, and a coil spring that communicates with the retracting groove portion 34 and biases the lock plate 80 inward in the radial direction. Spring housing hole 35 for housing 81
Are formed. In addition, the four operating hydraulic chambers R described above
0 is formed between each of the five convex portions 33.

As described above, the flat lock plate 80 having a constant thickness is arranged so as to extend in the axial direction of the outer rotor 30. When the inner rotor 20 and the outer rotor 30 are in a locked state, the inner rotor 20 moves to the lock plate 8
The load applied to 0 is received by the wall surface of the retraction groove portion 34. Even when the lock plate 80 is retracted to the retracting groove portion 34 or in the process of being pushed out from the retracting groove portion 34 so as to fit into the receiving groove portion 22, the lock plate 80 having a certain thickness is reliably supported by the wall surface of the retracting groove portion 34. The strength can be more advantageously secured as compared with the lock plate having the tapered tip as in the example of the prior art cited at the beginning.

The torsion spring 60 has one end locked to the front plate 40 and the other end locked to the inner rotor 20, and is attached to the outer rotor 3 of each vane 70.
0, the front plate 40 and the rear plate 50 are provided in consideration of the resultant friction force. That is, the torsion spring 60 connects the inner rotor 20 to the outer rotor 3
0, the front plate 40 and the rear plate 50 are biased toward the advance side (clockwise direction in FIG. 2). Therefore,
The configuration is such that the operation response of the internal rotor 20 to the advance side is improved.

As shown in FIG. 4, the spring accommodating hole 35 is formed.
A coil spring 81 is arranged therein so as to push the lock plate 80 toward the radial center of the outer rotor 30. The spring accommodating hole 35 is connected to the outer rotor 3 via the communication hole 36.
No. 0 communicates with the outside, the back pressure of the lock plate 80 is always atmospheric pressure, and its smooth operation is guaranteed. Further, the spring accommodation hole 35 and the communication hole 36 have a cross-sectional area larger than the cross-sectional area of the third hydraulic oil passage 25, so that the delay of the movement of the lock plate 80 is minimized.

As shown in FIG. 4, the lock plate 8
The hydraulic pressure acting to push 0 out of the receiving groove portion 22 is supplied from the third hydraulic oil passage 25. This hydraulic pressure is configured such that one side having the hydraulic oil groove 23a is sealed by the vane 70 and the other side is sealed by the narrow gap d between the outer peripheral surface of the internal rotor 20 and the sliding contact surface between the convex portion 33. FIG. 7 shows the relationship between the clearance d and the hydraulic pressure acting on the lock plate 80. Based on this test result, the gap d is 150μ
By configuring it to be equal to or less than m, the hydraulic pressure required to operate the lock plate 80 can be secured without providing a special seal.

FIG. 5 shows the relationship between the width a of the outer rotor 30, the width b of the inner rotor 23, and the width c of the lock plate 80. Since the hydraulic oil flows out from the portion with the least flow resistance, it is necessary to set these widths in a well-balanced manner. For this reason, in the structure of the present invention, the width c of the lock plate 80 having a small thickness is made larger than the width b of the internal rotor 23 to eliminate a portion where the hydraulic oil is concentrated and flows out. Of course, the width a of the outer rotor 30 is larger than the widths b and c, so that the inner rotor 23 and the lock plate 80 can rotate smoothly.

Further, as shown in FIG. 5, the tip of the head portion 80d of the lock plate 80 is formed in a linear shape up to the left and right end portions shown in FIG. This not only provides stronger support for the retreat groove portion 34, but also prevents the formation of a gap between the corner portion and the receiving groove portion 22 for accumulating foreign matter that may cause a malfunction.

The relative rotation of the inner rotor 20 and the outer rotor 30 so as to advance, that is, from the state of the most retarded position shown in FIG. 2, the vane 7 shown in FIG. Clockwise) is to move. The maximum advance angle is regulated at the position where the vane 70 abuts on one side surface in the circumferential direction of the convex portion 33, and the maximum retard angle is regulated at the position where the head portion 80d of the lock plate 80 enters the receiving groove portion 22. In this embodiment, the vane 70 does not come into contact with the other side surface of the convex portion 33 at the most retarded position, but the position of the receiving groove portion 22 can be formed so as to come into contact.

The operation of the valve opening / closing timing control device 1 of the present embodiment configured as above will be described. When the internal combustion engine is stopped, the oil pump 205 is stopped and the switching valve 2
00 is in a non-energized state, hydraulic oil (hydraulic pressure) is not supplied to the hydraulic pressure chamber R0. Therefore, the inner rotor 20 and the outer rotor 30 are in the most retarded position shown in FIG. 2 due to the cam friction acting in the retarded direction. And
As shown in FIG. 4, the head 80 of the lock plate 80
d is fitted in the receiving groove portion 22 of the inner rotor 20, and the relative rotation of the inner rotor 20 and the outer rotor 30 is restricted at the most retarded position. Even if the internal combustion engine is started and the oil pump is driven, the operation supplied from the oil pump while the duty ratio of energizing the switching valve 200 is small (the ratio of energizing time to non-energizing time per unit time is small). Oil (hydraulic pressure) is applied to the connection passage 15, the retard passage 12 and the passage 24.
The valve opening / closing timing control device 1 is maintained in the locked state because the valve opening / closing timing control device 1 is substantially supplied to the retarding angle oil chamber R2.

When the valve opening / closing timing needs to be advanced depending on the operating conditions of the internal combustion engine, the duty ratio for energizing the switching valve 200 is increased and the position of the spool 204 is switched. Hydraulic oil supplied from the oil pump (hydraulic pressure)
Through the connecting passage 16, the advance passage 11 and the first hydraulic oil passage 23, or from the third passage 25 to the receiving groove portion 22.
Is supplied to the advance oil chamber R1 through the hydraulic oil groove 23.

On the other hand, the working oil (hydraulic pressure) in the corner oil chamber R2 is discharged from the discharge port of the switching valve 200 via the passage 24, the retard passage 12 and the connection passage 15. Therefore, the lock plate 80 moves against the spring 81, the head portion 80d of the lock plate 80 comes out of the receiving groove 33 to unlock the inner rotor 20 and the outer rotor 30, and rotates integrally with the camshaft 10. The inner rotor 20 and each vane 70 rotate relative to the outer rotor 30 and the rear and the front plates 40 and 50 in the advance side (clockwise direction in FIG. 2). Due to this relative rotation, the state of FIG. 2 shifts to the state of FIG. 3, and the cam timing is advanced. By controlling the duty ratio of the control valve 200, the relative rotational position can be stopped at an arbitrary position, for example, an intermediate position as shown in FIG.

After the head portion 80d of the lock plate 80 is removed from the receiving groove portion 22, the inner rotor 20 and the outer rotor 30 are
Is rotated by a predetermined amount or more, as shown in FIG.
The communication between 5 and the receiving groove portion 22 is blocked, and the vibration of the lock plate 80 due to the pulsation of hydraulic oil (hydraulic pressure) is prevented. When the lock plate 80 is removed from the receiving groove portion 22,
When the duty ratio of energizing the switching valve 200 is reduced, the hydraulic oil (hydraulic pressure) can be supplied to each retarding oil chamber R2, and the hydraulic oil can be discharged from each advancing oil chamber R1. You can Therefore, for example, from the position of FIG. 4 to the position of FIG. 3 and from the position of FIG. 3 to the position of FIG. Can be relatively rotated to the retard side (counterclockwise direction in FIG. 2).

[0038]

As described above, in the valve opening / closing timing control device in which the width of the receiving groove is set wider than the width of the retracting groove as described above, the lock plate is formed in a plate shape having a constant width, and the support is provided by the short retracting groove. It becomes possible and the valve opening / closing timing control device can be downsized.

Further, the hydraulic pressure acting on the lock plate is secured without using the seal member by configuring the gap between the rotation transmitting member forming the working hydraulic chamber and the sliding contact portion of the rotating member to be 150 μm or less. As a result, it becomes possible to realize a valve opening / closing timing control device which is simple in structure and inexpensive.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a valve opening / closing timing control device according to an embodiment of the present invention, which is a cross-section taken along a portion shown in FIG.

2 is a most retarded state of the valve opening / closing timing control device, showing a BB cross section in FIG. 1;

FIG. 3 is an intermediate advance state of the valve opening / closing timing control device,
The BB cross section in FIG. 1 is shown.

FIG. 4 is an enlarged view of a portion D in FIG.

5 shows a DD cross section in FIG. 4. FIG.

FIG. 6 is a graph showing the occurrence rate of a lock plate fitting error and the hitting sound level with respect to the difference between the width I and the thickness H.

FIG. 7 is a graph showing a hydraulic pressure acting on a lock plate with respect to a clearance d.

[Explanation of symbols]

2 rotating members 3 Rotation transmission member 22 Receiving groove 23 First hydraulic oil passage 24 Second hydraulic oil passage 25 Third hydraulic fluid passage 34 Evacuation groove 70 vanes 80 Lock member (Lock plate) 81 spring (coil spring) 100 cylinder head R0 working hydraulic chamber R1 advance oil chamber R2 retarding oil chamber d gap

Claims (3)

[Claims] 1. A valve opening / closing rotary member rotatably assembled to a cylinder head of an internal combustion engine, and a rotary member assembled relative to the rotary member so as to be relatively rotatable within a predetermined range to transmit rotational power from a crankshaft. A rotation transmission member, a vane provided on one of the rotation member or the rotation transmission member, and an advance oil chamber and a retard oil by the vane formed between the rotation member and the rotation transmission member. Formed in the rotation transmission member or the rotation member, and a first and second hydraulic oil passages that supply and discharge hydraulic oil to and from the advance and retard oil chambers, respectively. A retracting groove portion for accommodating a plate-shaped lock member biased toward the rotation member or the rotation transmission member by a spring; and the rotation portion formed in the rotation member or the rotation transmission member. Provided with a receiving groove head of the locking member is retracted when matched relative position a predetermined position of the rotation transmitting member, and a third hydraulic oil passage for supplying and discharging hydraulic oil to the receiving unit,
A valve opening / closing timing control device for controlling opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, wherein a width of the receiving groove is set wider than a width of the retracting groove. 2. The valve opening / closing timing control device according to claim 1, wherein a width of the lock member is narrowed within a range of 0.2 mm to 0.8 mm with respect to a width of the receiving groove portion. 3. A valve opening / closing rotary member rotatably assembled to a cylinder head of an internal combustion engine, and a rotary member assembled relative to the rotary member so as to be relatively rotatable within a predetermined range to transmit rotational power from a crankshaft. A rotation transmission member, a vane provided on either the rotation member or the rotation transmission member, and an advance oil chamber and a retard oil by the vane formed between the rotation member and the rotation transmission member. Formed in the rotation transmission member or the rotation member, and a first and second hydraulic oil passages that supply and discharge hydraulic oil to and from the advance and retard oil chambers, respectively. A retracting groove portion for accommodating the lock member biased toward the rotation member or the rotation transmission member by a spring; and the rotation member and the rotation member formed in the rotation member or the rotation transmission member. A receiving groove portion into which the head of the lock member is inserted when the relative positions of the transmitting members are synchronized with each other in a predetermined phase; and a third hydraulic oil passage for supplying and discharging hydraulic oil to and from the receiving portion,
In a valve opening / closing timing control device for controlling opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, a gap between a sliding contact portion of the rotation transmitting member forming the working hydraulic chamber and the rotating member is set to 150 μm or less. Valve opening / closing timing control device.