JP4389414B2 - Valve timing control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a valve opening / closing timing control device for controlling the opening / closing timing of intake and exhaust valves of an internal combustion engine.
[0002]
[Prior art]
As a conventional valve opening / closing timing control device, there is a technique disclosed in Japanese Patent Laid-Open No. 2001-3716. This includes a rotation member for opening and closing a valve assembled to a cylinder head of an internal combustion engine, a rotation transmission member engaged with the rotation member in a relatively rotatable manner, a vane provided on one of the rotation member or the rotation transmission member, and rotation A fluid pressure chamber divided into an advance angle chamber and a retard angle chamber by a vane formed between the member and the rotation transmission member, and a first for supplying and discharging fluid to the advance angle chamber and the retard angle chamber, respectively. And a second fluid passage, formed in the rotating member or the rotation transmitting member, urged by the spring toward the rotating member or the rotation transmitting member, and supplying the fluid pressure to one side, the high pressure side and the low pressure side on both sides A retraction part that accommodates the lock member to be formed, a receiving part that is formed on the rotation member or the rotation transmission member, and the head of the lock member is immersed when the relative phase of the rotation member and the rotation transmission member is synchronized at a predetermined phase; First to supply and discharge fluid to the receiving part It is obtained by a fluid passageway.
[0003]
In this valve opening / closing timing control device, since the corner on the low pressure side of the lock member has a square shape, when the lock member is released, the lock member swings with a spring that urges the lock member toward the rotation member as a fulcrum. The corner portion on the low-pressure side is slid while being caught by the inner wall of the receiving portion, thereby promoting wear of the inner wall of the receiving portion and increasing the sliding resistance of the lock member. Further, since the corner (R portion) on the high-pressure side has an R shape, foreign matter such as wear powder generated from the sliding portion of the internal combustion engine accumulates in the R portion and becomes easy to bite. These cause a malfunction of the lock member, and increase the possibility that the internal combustion engine cannot be started and abnormal noise occurs at the start.
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION Accordingly, it is a technical object of the present invention to improve the operability of a lock member in a valve opening / closing timing control device and to reduce malfunctions of an internal combustion engine due to malfunction.
[0005]
In order to solve the above technical problem, the means taken in the invention of claim 1 includes a rotary member for opening and closing a valve, a rotation transmission member engaged with the rotary member so as to be relatively rotatable, the rotary member or the rotary member. A vane provided on one of the rotation transmission members, a fluid pressure chamber formed between the rotation member and the rotation transmission member, and divided into an advance chamber and a retard chamber by the vane; A lock groove formed in the rotation member and the rotation transmission member, and a relative pressure between the rotation member and the rotation transmission member disposed in the lock groove is regulated, and fluid pressure is supplied to one side to supply high pressure to both sides. A valve opening / closing timing control device comprising: a lock member that forms a side and a low pressure side; and first and second fluid passages that supply and discharge fluid to and from the advance and retard chambers and the lock groove, respectively. the one in which fluid pressure acts The surface is a low pressure side of the corner R shape is corner between the locking groove and the sliding surfaces of the projecting and retracting direction parallel to the surface opposite to the surface with the locking member, the fluid pressure The corner portion on the high-pressure side, which is the corner portion between the acting surface on one side and the surface parallel to the lock-out direction of the lock member, and the surface that slides on the lock groove has an angular shape.
[0006]
According to this means, when releasing the lock member, the low pressure side R portion (corner portion) reduces the sliding resistance due to the inclination of the lock member and improves the slidability, and also the internal combustion which is going to accumulate in the R portion. Since foreign matter such as abrasion powder generated from the sliding portion of the engine is washed away by the working fluid that flows from the high pressure side to the low pressure side, the problem of biting can be prevented. The high-pressure side corner can prevent accumulation and biting of foreign matters due to the square shape.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0008]
The valve opening / closing timing control device shown in FIGS. 1, 2 and 5 is a valve opening / closing composed of an internal rotor 20 which is integrally assembled with the tip of a camshaft 10 rotatably supported by a cylinder head 100 of an internal combustion engine. Rotation transmission composed of a rotary member for rotation and an external rotor 30, a front plate 40, a rear plate 50, and a timing sprocket 31 integrally provided on the outer periphery of the external rotor 30 that are mounted on the internal rotor 20 so as to be relatively rotatable within a predetermined range. A member, four vanes 70 assembled to the inner rotor 20, a lock key 80 assembled to the outer rotor 30, and the like. As is well known, rotational power is transmitted to the timing sprocket 31 in a clockwise direction in FIG. 2 from a crankshaft (not shown) via a crank sprocket and a timing chain.
[0009]
The inner rotor 20 is integrally fixed to the camshaft 10 (not shown) by a single mounting bolt 91, and includes four vane grooves 21, a receiving groove (receiving portion) 22, and four passages (first passages) extending in the radial direction. The second fluid passages 23 and 24 are provided. The hydraulic oil (working fluid) is supplied and discharged through the retard passage 12 and the passage 24 to the four retard oil chambers R2 defined by the vanes 70. A leaf spring 73 is disposed between the bottom of the vane groove 21 and the bottom surface of the vane 70, and each of the four vanes 70 is attached to the vane groove 21 so as to be movable in the radial direction. When the relative position of the camshaft 10 and the internal rotor 20 and the external rotor 30 is synchronized at a predetermined phase (most retarded angle position), the head of the lock key 80 has a predetermined amount in the receiving groove 22 as shown in FIG. Immerse yourself. The hydraulic oil from the advance passage 23 is supplied to the receiving groove 22.
[0010]
The outer rotor 30 is assembled to the outer periphery of the inner rotor 20 so as to be relatively rotatable within a predetermined angle range. An annular front plate 40 and a rear plate 50 are joined to both sides of the outer rotor 30 and are integrally connected by four connecting bolts 92. A timing sprocket 31 is integrally formed on the outer periphery of the axial end portion of the outer rotor 30 to which the front plate 40 is joined.
[0011]
Four protrusions 33 are formed on the inner periphery of the outer rotor 30 in the circumferential direction. The inner peripheral surfaces of these convex portions 33 are in contact with the outer peripheral surface of the inner rotor 20, and the outer rotor 30 is rotatably supported by the inner rotor 20. A certain projecting portion is provided with a retracting groove 34 for storing the lock key 80 and a storing groove 35 for the spring 81 that communicates with the retracting groove 34 and biases the lock key 80 radially inward.
[0012]
The lock key 80 is supplied with hydraulic pressure radially inward to form a high-pressure side and a low-pressure side on the inside and outside in the radial direction, and the corners 80a and 80b on the low-pressure side are R-shaped and corners on the high-pressure side. 80c and 80d have a square shape.
[0013]
The torsion spring 60 is assembled with one end locked to the front plate 40 and the other end locked to the internal rotor 20, and the frictional engagement force of each vane 70 with respect to the external rotor 30, front plate 40 and rear plate 50. It is provided in consideration of (force that inhibits rotation to the advance side). The torsion spring 60 biases the inner rotor 20 toward the advance side with respect to the outer rotor 30, the front plate 40 and the rear plate 50.
[0014]
Each vane is a fluid pressure chamber R0 formed between the plates 40, 50 in the axial direction, between the outer rotor 30 and the inner rotor 20 in the radial direction, and between the adjacent convex portions 33 in the circumferential direction. Is divided into an advance oil chamber (advance chamber) R1 and a retard oil chamber (retard chamber) R2. The relative rotation amount between the inner rotor 20 and the outer rotor 30 depends on the circumferential width (angle) of the fluid pressure chamber R0. On the most advanced angle side, the relative rotation is restricted at a position where the vane 70a abuts on one side surface in the circumferential direction of the convex portion 33a. Be regulated. On the retard side, the head of the lock key 80 enters the receiving groove 22 to restrict the relative movement of the inner rotor and the outer rotor.
[0015]
The operation of the valve timing control apparatus of the present embodiment configured as described above will be described. When the internal combustion engine is stopped, the oil pump 205 is stopped and the switching valve 200 is in a non-energized state, so that hydraulic fluid is not supplied to the fluid pressure chamber R0. For this reason, the internal rotor 20 and the external rotor 30 are synchronized at the most retarded position as shown in FIG. 2 due to cam friction acting in the retarded direction. Here, the head of the lock key 80 is fitted into the receiving groove 22 of the inner rotor 20 by a predetermined amount, and the relative rotation between the inner rotor 20 and the outer rotor 30 is restricted at the most retarded angle position. is there. Even when the internal combustion engine is started and the oil pump is driven, the hydraulic oil supplied from the oil pump substantially passes through the connection passage 15, the retard passage 12, and the passage 24 as long as the duty ratio energizing the switching valve 200 is small. Therefore, the valve timing control device is still maintained in the locked state shown in FIG.
[0016]
When an advance angle is required at the valve opening / closing timing 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. Therefore, hydraulic oil (hydraulic pressure) supplied from the oil pump Is supplied to the advance oil chamber R1 through the connection passage 16, the advance passage 11 and the passage 23. Further, it is also supplied from the passage 23 to the receiving groove 22. On the other hand, the hydraulic oil (hydraulic pressure) in the retarding oil chamber R <b> 2 is discharged from the discharge port of the switching valve 200 through the passage 24, the retarding passage 12, and the connection passage 15. At this time, the radially inner side of the lock key 80 of the receiving groove 22 has a high pressure and the radially outer side has a low pressure, and hydraulic oil (hydraulic pressure) is supplied from a slidable gap formed between the lock key 80 and the receiving groove 22. Flowing. Accordingly, the accumulation and biting of foreign matters are prevented by the angular shapes of the corner portions 80c and 80d on the radially inner side of the lock key 80, and the foreign matters are washed away by the working fluid by the R shapes of 80a and 80b on the radially outer side. Next, the lock key 80 moves against the spring 60 disposed on the low-pressure side, and the head of the lock key 80 comes out of the receiving groove 22 disposed on the high-pressure side to lock the inner rotor 20 and the outer rotor 30. The internal rotor 20 and the vanes 70 that rotate together with the camshaft 10 are rotated relative to the external rotor 30 and the plates 40 and 50 in the advance side (clockwise direction). This relative rotation can reach from the most retarded state of FIG. 2 to the most advanced state of FIG. 4 through the intermediate advanced state of FIG. Since the corners 80a and 80b on the low pressure side of the lock key 80 are formed in an R shape, when the lock by the lock key 80 is released, the sliding resistance due to the tilt of the lock key 80 can be reduced, and the sliding Wear of moving parts is reduced.
[0017]
In a state where the lock key 80 is removed from the receiving groove 22, if the duty ratio energizing the switching valve 200 is reduced, the hydraulic oil can be supplied to each retarding oil chamber R2, and each advance angle The hydraulic oil can be discharged from the oil chamber R1. Therefore, the inner rotor 20 and each vane 70 are delayed with respect to the outer rotor 30, both plates 40, 50, etc. steplessly from the position of FIG. 4 to the position of FIG. 3 and from the position of FIG. 3 to the position of FIG. It can be rotated relative to the corner (counterclockwise).
[0018]
【The invention's effect】
As described above, according to the present invention, the corner portion (R portion) on the low pressure side of the lock member is formed in an R shape, so that wear of the sliding portion of the lock member can be prevented and sliding caused by rattling (tilting) can be prevented. In addition to reducing the resistance, foreign matter such as abrasion powder generated from the sliding portion of the internal combustion engine that is about to accumulate in the R portion is washed away by the working fluid that flows from the high pressure side to the low pressure side, so that the problem of biting can be prevented. . On the other hand, by forming the corner portion on the high-pressure side of the lock member into a square shape, it is difficult for foreign matter to accumulate and foreign matter to be caught, thereby preventing malfunction.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a valve timing control apparatus according to an embodiment of the present invention.
FIG. 2 is a front view of the valve opening / closing timing control device in the most retarded state with the front plate 40 removed in FIG.
FIG. 3 is a front view similar to FIG. 2 in an intermediate advance state of the valve timing control device.
FIG. 4 is a front view similar to FIG. 2 in the most advanced angle state of the valve timing control device.
FIG. 5 is an enlarged longitudinal sectional view of a lock key portion of the valve opening / closing timing control device.
[Explanation of symbols]
20: Internal rotor (rotating member)
22 ... Reception groove (lock groove)
23 .. passage (first fluid passage)
24 ... passage (second fluid passage)
30 ... External rotor (rotation transmission member)
34 ... Retraction groove (lock groove)
70 ... Vane 80 ... Lock key (lock member)
R0: Fluid pressure chamber R1: Advance oil chamber (advance chamber)
R2 ... retarding oil chamber (retarding chamber)

Claims (2)

A rotating member for opening and closing the valve;
A rotation transmitting member engaged with the rotating member so as to be relatively rotatable;
A vane provided on one of the rotating member or the rotation transmitting member;
A fluid pressure chamber formed between the rotation member and the rotation transmission member and divided into an advance chamber and a retard chamber by the vane;
A lock groove formed in the rotation member and the rotation transmission member;
A lock member that is disposed in the lock groove and restricts relative rotation of the rotation member and the rotation transmission member, and forms a high pressure side and a low pressure side on both sides by supplying fluid pressure to one side;
In the valve timing control device comprising the first and second fluid passages for supplying and discharging fluid to and from the advance and retard chambers and the lock groove, respectively.
The low pressure side which is a corner portion between the surface opposite to the one surface on which the fluid pressure of the lock member acts and the surface that slides with the lock groove out of the surfaces parallel to the retracting direction of the lock member The corner portion of the high-pressure side is a corner portion between the one surface on which the fluid pressure acts and the surface that slides with the lock groove among the surfaces parallel to the retracting direction of the lock member . A valve opening / closing timing control device characterized in that a corner portion has a square shape. The corner portion on the low pressure side is a corner portion of the locking member on the radially outer side of the rotating member, and the corner portion on the high pressure side is a corner portion of the locking member on the radially inner side of the rotating member. The valve opening / closing timing control device according to claim 1.

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