JPH0960508A - Valve timing adjusting device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To high accurately control opening/closing of at least either an intake valve or an exhaust valve, by locking a housing member and a vane member to prevent the generation of a tapping sound therebetween, when no fluid of prescribed pressure is supplied from a drive means. SOLUTION: In a condition that no pressure oil is supplied to pressure oil chambers 23, 24 from a pump 46 at the time of starting an engine, a tip end part 7c of a stopper piston 7 is fitted to a stopper hole 20, so as to lock a shoe housing 3 and a vane rotor 9 integrally rotated. Accordingly, even when positive/negative reverse torque is generated in a cam shaft 2, a tapping sound of the vane rotor 9 and the show housing 3 is prevented from being generated. When pressure oil is forcedly fed to the pressure oil chamber 23 or 24, the stopper piston 7 comes off from the stopper hole 20, and the vane rotor 9 is released for the connection to the shoe housing 3, so that the relative turning of the vane rotor 9 relating to the show housing 3 can be controlled by a pressure of oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine (hereinafter referred to as "internal combustion engine").
The present invention relates to a valve timing adjustment device for changing the opening / closing timing of at least one of an intake valve and an exhaust valve of an "internal combustion engine" as an engine according to operating conditions.

[0002]

2. Description of the Related Art Conventionally, a camshaft is driven via a timing pulley or a chain sprocket that rotates in synchronization with an engine crankshaft, and the intake valve and the exhaust valve are driven by the phase difference caused by the relative rotation of the timing pulley or the chain sprocket and the camshaft. As a vane type valve timing adjusting device for opening and closing at least one of the valves, the one disclosed in Japanese Patent Laid-Open No. 1-92504 is known.

In the one disclosed in Japanese Patent Application Laid-Open No. 1-92504, knock pins are housed on both sides of the timing pulley in the radial direction. The rotary rotor rotates together with the cam shaft and the vane, and is rotatable relative to the timing pulley. The rotary rotor is provided with a hole into which either of the two knock pins can be fitted when the vane rotates in the retard direction or the advance direction with respect to the timing pulley. Therefore, when the rotary rotor rotates in the retard angle direction or the advance angle direction with respect to the timing pulley together with the vane, the knock pin fits into the hole of the rotary rotor, so that the timing pulley and the rotary rotor rotate together. Also, when changing the phase of the rotary rotor with respect to the timing pulley from the state where the knock pin is fitted in the hole, the knock pin comes out from one hole by switching the hydraulic pressure, and after the rotary rotor rotates, the knock pin is put in the other hole. The fitting causes the timing pulley and the rotary rotor to rotate together again. As a result, even if the camshaft produces positive or negative torque with respect to the timing pulley due to the drive of the intake valve or the exhaust valve, the timing pin and the rotating rotor are connected by the knock pin, so that the vane and the timing pulley are connected. It is possible to prevent the tapping sound from being generated.

[0004]

However, in the device disclosed in Japanese Patent Laid-Open No. 1-92504, the knock pin rotates every time the rotary rotor rotates in the advance direction or the retard direction with respect to the timing pulley. The knock pin and the hole are easily worn because they come out from one hole of the rotor and fit into the other hole.In addition, the knock pin cannot be fitted into the hole unless the knock pin and hole are processed with high precision. It may occur.

Further, since the knock pin operates in the radial direction of the rotary rotor, there is a problem that centrifugal force may affect the operation of the knock pin. The present invention has been made to solve such a problem, and when the fluid of a predetermined pressure is not supplied from the driving means, the housing member and the vane member are restrained to generate a tapping sound between the housing member and the vane member. An object of the present invention is to provide a valve timing adjusting device for an engine that prevents the above.

[0006]

According to the valve timing adjusting apparatus for an engine of the first aspect of the present invention, the abutting portion and the covered portion for restraining the rotational movement directions of the housing member and the vane member at a predetermined restraining position. Restraint means having an abutting portion and a biasing means for biasing the abutting portion in a direction of abutting the abutted portion is provided on the housing member and the vane member, and resists the biasing force of the biasing means. By displacing the contact portion in the restraint releasing direction by the fluid pressure, the vane member can be relatively rotated by the fluid pressure with respect to the housing member. For example, immediately after the engine is started, by urging the contact portion with the urging means in a state where the predetermined pressure that can control the relative rotational phase difference between the housing member and the vane member has not been reached even if the drive means is activated, The honing member and the vane member are in a restrained state. Therefore, even if the driven shaft that opens and closes at least one of the intake valve and the exhaust valve undergoes positive and negative torque fluctuations, it is possible to prevent the housing member and the vane member from colliding with each other, and to prevent tapping noise.

Further, it is desirable that the drive means uses hydraulic pressure as a drive source. Further, it is desirable that the drive means has a first hydraulic pressure for relatively rotating the vane member in the advance direction with respect to the housing member and a second hydraulic pressure for relatively rotating the vane member in the retard direction. According to the valve timing adjusting device for an engine of the second aspect of the present invention, the contact portion is displaced along the rotation axis direction of the housing member, so that the centrifugal force accompanying the rotation of the drive shaft or the driven shaft is brought into contact with the contact portion. It is possible to reduce the influence on the displacement of.

According to the valve timing adjusting apparatus for an engine of the third aspect of the present invention, by providing the abutting portion or the abutted portion with an inclined surface for pressing the housing member and the vane member in the direction of further abutting, the inclined surface is provided. The wedge functions as a wedge and can strongly restrain the housing member and the vane member. According to the engine valve timing adjusting device of the fourth aspect of the present invention, by forming the tapered surface on at least one of the stopper piston and the stopper hole, the housing member and the vane member are further contacted with each other. Can be pressed.
Therefore, the housing member and the vane member can be firmly restrained, the fitting amount change in the displacement direction of the stopper piston can be allowed, and the positional deviation between the stopper piston and the stopper hole can be absorbed.

According to the engine valve timing adjusting device of the fifth aspect of the present invention, since the stopper hole is formed in an elongated hole shape that is long in the radial direction of the housing member, the stopper piston and the stopper hole are formed in the housing member. To prevent abutting in the radial direction. Therefore, it is possible to prevent the wedge action from occurring due to the inclined surface on the radial side of the tapered surface, and to prevent the housing member and the vane member from being relatively urged in the radial direction, and thus the housing member and the vane member. Uneven wear is prevented, and good rotation of the housing member and the vane member can be maintained.

According to the valve timing adjusting apparatus for an engine of claim 6 of the present invention, the stopper piston is housed in the vane member so as to be displaceable, and the stopper hole into which the stopper piston can be fitted is formed in the housing member. By making the surface of one of the fitting portions a tapered surface, it is possible to allow a change in the amount of fitting of the stopper piston in the displacement direction, and to absorb the positional deviation between the stopper piston and the stopper hole.

According to the valve timing adjusting apparatus for an engine of claim 7 of the present invention, since the stopper piston is housed in the vane member, the housing member and the vane member are released from the restraint state, so that the stopper piston is housed. The space can be easily secured, and the configuration of the working fluid fluid circuit for releasing the constraint is facilitated. According to the engine valve timing adjusting device of the eighth aspect of the present invention, since the fluid bumper for reducing the displacement speed of the contact portion is formed between the contact portion and the contacted portion, the housing member is formed. The fluid pressure acting on the abutment is momentary during the transitional period when the abutment is at a position where it can be displaced in the direction of restraining the vane member and the fluid pressure switches from the constraint-released state to another constraint-released state. It is possible to prevent the contact portion from being momentarily displaced in the restraining direction when lowered.

According to the valve timing adjusting apparatus for an engine of claim 9 of the present invention, when the restraint is released,
Since the contact portion closes the communication hole with the outside of the back pressure chamber, even if the contact portion tries to displace in the restraining direction, the atmosphere cannot be introduced into the back pressure chamber from the communication hole, so that the contact portion is restrained in the restraining direction. The displacement speed of is moderated. As a result, the abutting portion acts on the abutting portion in a transitional period in which the abutting portion is displaceable in the direction of restraining the housing member and the vane member and the fluid pressure switches from the restraint-released state to another restraint-released state. It is possible to prevent the contact portion from momentarily displacing in the restraining direction when the fluid pressure to be applied decreases for a moment.

According to the valve timing adjusting apparatus for an engine of the tenth aspect of the present invention, the abutting portion and the abutted portion abut each other when the driven shaft is in the most retarded state in which the driven shaft is most retarded, The housing member and the vane member are constrained to each other. As a result, the housing member and the vane member are constrained at the most retarded position, which is excellent in engine startability, and when the fluid pressure supplied by the drive means is not sufficiently increased as when the engine is started, the engine It is possible to prevent tapping of the valve timing adjusting device while ensuring startability.

The restraint in the most retarded state is to restrain the housing member and the vane member when the vane member is at the most retarded side with respect to the housing member when the vane member rotates together with the driven shaft. It can be achieved by doing. On the other hand, when the vane member rotates together with the drive shaft, it can be achieved by restraining the housing member and the vane member when the vane member is at the most advanced position with respect to the housing member.

According to the valve timing adjusting apparatus for an engine of claim 11 of the present invention, the abutment portion has the first fluid pressure for changing the valve timing to the advance side and the second fluid for changing the valve timing to the retard side. It is driven and held toward an unrestrained state by both pressure. Therefore, when the fluid pressure is supplied from the drive means to either one, the contact portion can be held in an unconstrained state at all times, so that the number of times of operation of the contact portion can be reduced and durability can be improved. You can

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIGS. 1 to 8 show an engine valve timing adjusting device according to a first embodiment of the present invention. FIG.
It shows a hydraulic circuit of the first embodiment.

The chain sprocket 1 shown in FIG. 1 is driven by a chain (not shown) from a crankshaft serving as a drive shaft of an engine (not shown) to rotate, and rotates in synchronization with the crankshaft. The camshaft 2 as a driven shaft receives the driving force from the chain sprocket 1 and drives at least one of an intake valve and an exhaust valve (not shown) to open and close. The camshaft 2 is rotatable with a predetermined phase difference with respect to the chain sprocket 1. The chain sprocket 1 and the camshaft 2 rotate clockwise as viewed from the arrow X direction shown in FIG. Hereinafter, this rotation direction is referred to as an advance direction.

As shown in FIGS. 1 and 2, the chain sprocket 1, the shoe housing 3, and the front plate 4, which are housing members, are coaxially fixed by bolts 14. Boss 1a of chain sprocket 1
The inner peripheral wall of is fitted to the tip portion 2a of the camshaft 2 so as to be relatively rotatable. The front plate 4 and the shoe housing 3 are positioned by a knock pin 26, and the shoe housing 3 and the chain sprocket 1 are positioned by a knock pin 27 in the rotational angle direction.

As shown in FIG. 2, the shoe housing 3 has trapezoidal shoes 3a and 3b facing each other. The respective facing surfaces of the shoes 3a and 3b are formed in an arcuate cross section, and the vanes 9a and 9b are respectively provided in the two circumferential gaps of the shoes 3a and 3b.
The fan-shaped space portion that is the accommodation chamber of is formed. As shown in FIGS. 1 and 2, a vane rotor 9 as a vane member has fan-shaped vanes 9a and 9b at both ends in the radial direction, and the vanes 9a and 9b are shoes 3a and 3b.
Is rotatably housed in a fan-shaped space formed in the circumferential gap. The pilot portion 9c is the camshaft 2
The vane rotor 9 is integrally fixed to the camshaft 2 by means of bolts 15 and is coaxially fitted to the tip 2a of the. The vane rotor 9 and the cam shaft 2 are positioned by a knock pin 28 in the rotational angle direction. The cylindrical protrusion 5 fixed integrally with the vane rotor 9 is fitted to the inner peripheral wall of the front plate 4 so as to be relatively rotatable. As shown in FIG. 2, minute clearances 16 and 17 are provided between the outer peripheral wall of the vane rotor 9 and the inner peripheral wall of the shoe housing 3.
The vane rotor 9 is rotatable relative to the shoe housing 3. A retard hydraulic chamber 10 is formed between the shoe 3a and the vane 9a, and a retard hydraulic chamber 11 is formed between the shoe 3b and the vane 9b.
An advance hydraulic chamber 12 is formed between the vane 9b and the vane 9b, and an advance hydraulic chamber 13 is formed between the shoe 3b and the vane 9a. The axial length of the vanes 9a and 9b is
It is set to be slightly smaller than the axial length of the shoe housing 3 sandwiched between the front plate 4 and the chain sprocket 1.

With the above structure, the cam shaft 2 and the vane rotor 9 can be coaxially rotated relative to the chain sprocket 1, the shoe housing 3 and the front plate 4. As shown in FIG. 1, the stopper piston 7 as the contact portion is housed inside the vane 9 a of the vane rotor 9. The stopper piston 7 is composed of a small diameter portion 7a and a large diameter portion 7b, and the tip portion 7 of the small diameter portion 7a.
c is formed in a taper shape that is slightly tapered as it goes toward the side of the larger diameter portion 7b, that is, in the direction in which the stopper piston 7 is fitted into the stopper hole 20 as the contacted portion. The large-diameter portion 7b of the stopper piston 7 is housed in the housing hole 8 of the vane 9a, and is supported by the inner wall of the vane 9a forming the housing hole 8 so as to be slidable in the axial direction of the camshaft 2. A spring 18 as a biasing means is incorporated in the accommodation hole 8 on the right side in the axial direction of the stopper piston 7 shown in FIG. The guide ring 19 is loosely fitted or press-fitted to the inner wall of the vane 9a forming the accommodation hole 8, and is loosely fitted to the outer wall of the small diameter portion 7a of the stopper piston 7. Therefore, the stopper piston 7 is accommodated in the vane 9 a so as to be slidable in the axial direction of the cam shaft 2, and is biased by the spring 18 toward the front plate 4 side.

As shown in FIG. 4, the taper angle of the tip portion 7c of the stopper piston 7 and the taper angle of the stopper hole 20 are set to be the same, and when the stopper piston 7 is fitted in the stopper hole 20, The front end surface 7d of the stopper piston 7 is not in contact with the upper surface 20b of the stopper hole 20. As shown in FIGS. 1 and 2, when the vane rotor 9 is at the most retarded position as the restraining position with respect to the shoe housing 3, the pressure oil has not yet been introduced into the hydraulic chambers 23 and 24. The stopper piston 7 is fitted into the stopper hole 20 by the urging force. At this time, the stopper portion 9e formed on the retard side of the vane 9b
Is in contact with the side surface of the shoe 3 a, and the vane rotor 9 receives the driving force directly from the shoe housing 3.

Position of stopper piston 7 and stopper hole 2
The 0 position is designed to press these parts against each other when the shoe housing 3 and the vane rotor 9 are at the most retarded position. That is, when the stopper portion 9e in FIG.
The positions of the two are designed so as to be eccentrically fitted to the shaft center 101 in the advance direction side as shown in FIG. When the stopper piston 7 is fitted in the stopper hole 20, the outer peripheral taper surface of the stopper piston 7 and the stopper hole 2
The contact with the inner peripheral taper surface of 0 causes the stopper piston 7
Acts like a wedge against the stopper hole 20, so that the vane rotor 9 and the shoe housing 3 are relatively moved in the rotational direction under the urging force of the stopper piston 7 in the axial direction. In the first embodiment, as shown in FIG. 4, the tapered surfaces abut on the advancing direction side opposite to the most retarded angle side as the restrained position. Therefore, the inclined surface of the tapered surface generates an urging force in the rotation direction due to the urging force of the stopper piston 7 in the axial direction,
In FIG. 2, the vane rotor 9 is biased counterclockwise and the shoe housing 3 is biased clockwise. Therefore, a biasing force that presses the stopper portion 9e against the side surface of the shoe 3a is obtained, and the shoe housing 3 and the vane rotor 9 are firmly restrained.

The position of the stopper piston 7 and the position of the stopper hole 20 are set so that even if there is a manufacturing error, both of them come into contact with each other on a predetermined side surface in the rotating direction of the vane member to exert the above-mentioned wedge effect. Should be. As shown in FIG. 1, a drain hole 21 is provided in the side wall of the vane 9a forming the accommodation hole 8 on the side of the chain sprocket 1, and when the vane rotor 9 is at the most retarded angle, the atmospheric hole 22 of the chain sprocket 1 is formed. Since the positions of the drain hole 21 and the drain hole 21 substantially coincide with each other, the space portion of the stopper piston 7, which is a part of the accommodation hole 8, on the spring 18 side corresponds to atmospheric pressure.
As shown in FIG. 1, a hydraulic chamber 23 is formed between the guide ring 19 and the large diameter portion 7b of the stopper piston 7. A hydraulic chamber 24 is formed between the stopper hole 20 of the front plate 4 and the small diameter portion 7a of the stopper piston 7, and the hydraulic chamber 24 and the advance hydraulic chamber 13 are communicated with each other by an oil passage 25 of the front plate 4. .

As shown in FIG. 1, FIG. 2 and FIG. 3, the vane rotor 9 has an oil passage 2 at the contact portion with the cylindrical protrusion 5.
9, an oil passage 30 is provided at the contact portion with the camshaft 2. The oil passage 29 communicates with the retard angle hydraulic chambers 10 and 11 through the oil passages 31 and 32, and communicates with the hydraulic chamber 23 through the oil passage 33. The oil passage 30 communicates with the advance hydraulic chambers 12 and 13 through the oil passages 34 and 35. Further, the oil passage 29 communicates with the oil passage 36, and the oil passage 36 is provided at the contact portion between the vane rotor 9 and the cam shaft 2 in the axial direction.
It communicates with an oil passage 39 formed inside. The oil passage 30 communicates with an oil passage 38 formed in the camshaft 2 at an axial contact portion between the vane rotor 9 and the camshaft 2.

As shown in FIG. 1, the journal portion 42 of the camshaft 2 is rotatably supported by a bearing portion 41 provided on the cylinder head 40 and is restricted from moving in the rotational axis direction. Outer peripheral grooves 43 and 44 are provided in the outer peripheral wall of the journal portion 42 in the circumferential direction. A supply oil passage 47 for pumping the oil in the oil tank 45 by a pump 46 and a discharge oil passage 48 for discharging the oil into the oil tank 45.
Is capable of selectively communicating or blocking with the outer peripheral grooves 43 and 44 by switching operation of the switching valve 49. Pump 4
6 and the switching valve 49 constitute hydraulic drive means. In this embodiment, the switching valve 49 is a well-known 4-port guide valve.

As shown in FIG. 3, the outer peripheral groove 43 is in communication with the oil passage 30 in the vane rotor 9 at the contact portion with the vane rotor 9 by the oil passages 37, 38 in the camshaft 2. As shown in FIG. 1, the outer peripheral groove 44 is formed in the camshaft 2
The oil passage 39 in the inside communicates with the oil passage 36 in the vane rotor 9 at the contact portion with the vane rotor 9. With the configuration described above, the pressure oil from the pump 46 is selectively supplied to the outer peripheral grooves 43 and 44 by the switching valve 49, and the retard angle hydraulic chambers 10 and 11 and the hydraulic chambers 23 and the advance hydraulic chambers 12 and 13 are provided.
Also, the pressure oil can be supplied from the pump 46 to the hydraulic chamber 24, and the oil can be discharged to the oil tank 45.

By forming the clearance 16 at the outermost diameter of the vanes 9a and 9b to be minute, the circumferential lengths of the vanes 9a and 9b are relatively long. 13, the retard hydraulic chamber 11 and the advance hydraulic chamber 12 are prevented from communicating with each other through the clearance 16 as much as possible. Further, the seal component 6 is mounted in the groove 9d of the vane rotor 9 in the minute clearance 17 formed in the minimum diameter portion of the shoes 3a and 3b, and the retard angle hydraulic chamber 10, the advance angle hydraulic chamber 12, and the retard angle hydraulic chamber. 11 and advance hydraulic chamber 1
3 is prevented from communicating via the clearance 17 as much as possible. Further, since the vane rotor 9 rotates relative to the shoe housing 3, a sliding clearance is formed between both axial end surfaces of the vane rotor 9 and the shoe housing 3 and the inner side surface of the chain sprocket 1. Oil may leak from the sliding clearance between the hydraulic chambers. However, by making the axial length of the vane rotor 9 slightly smaller than the axial length of the shoe housing 3, both ends of the vane rotor 9 in the axial direction can be reduced. The sliding clearance formed on the surface can be made minute. Further, the circumferential length of the vanes 9a and 9b is relatively long, that is, the cross-sectional area of the vanes 9a and 9b is large, so that the oil leak between the hydraulic chambers can be prevented as much as possible. Therefore, since the hydraulic pressure of each hydraulic chamber can be maintained at a predetermined value, the relative rotation of the vane rotor 9 with respect to the shoe housing 3 can be controlled with high accuracy. Further, since the cross-sectional area of the vanes 9a and 9b is large, the stopper piston 7 can be easily housed.

Next, the operation of the valve timing adjusting device will be described. As shown in FIGS. 1 and 2, when the pressure oil from the pump 46 at the time of engine start is not yet introduced into the hydraulic chambers 23 and 24, the vane rotor 9 is the slowest with respect to the shoe housing 3 as the crankshaft rotates. The stopper portion 9e is in contact with the shoe 3a on the retard side in the angular position, and the rotational driving force is transmitted from the chain sprocket 1 to the cam shaft 2 via the shoe housing 3 and the vane rotor 9. Further, the tip portion 7c of the stopper piston 7 is fitted into the stopper hole 20 by the urging force of the spring 18 so that the taper surface of the tip portion 7c of the stopper piston 7 contacts the taper surface of the stopper hole 20 on the advance side. By this fitting, the vane rotor 9 and the shoe housing 3 are urged in the rotating direction and firmly bound. Therefore, even if a positive / negative reversal torque is generated in the camshaft 2 when driving at least one of the intake valve and the exhaust valve, the vane rotor 9 moves to the retard side and the advance side with respect to the shoe housing 3. By restricting the movement, relative rotational vibration is not generated, and generation of tapping sound is prevented.

As shown in FIG. 5, 49 of the switching valve 49
When a is selected and the pressure oil is pumped from the pump 46, the pressure oil is supplied to the retard hydraulic chambers 10 and 11 and the hydraulic chamber 23 via the outer peripheral groove 44, the oil passages 39, 36, 29, 31, 32 and 33. Will be introduced. The force received by the stopper piston 7 due to the oil pressure in the hydraulic chamber 23 is the chain of the housing hole 8 against the urging force of the spring 18 due to the difference in pressure receiving area due to the diameter difference between the small diameter portion 7a and the large diameter portion 7b of the stopper piston 7. It works to push the stopper piston 7 toward the sprocket 1 side. Then, the tip end portion 7c of the stopper piston 7 completely comes out of the stopper hole 20 of the front plate 4, so that the vane rotor 9 is released from the constraint with the shoe housing 3.
However, since the hydraulic pressure in the retard hydraulic chambers 10 and 11 acts on the side surfaces of the vanes 9a and 9b, the vane rotor 9 is still held at the most retarded position shown in FIG. For this reason, generation of hammering sound between the vane rotor 9 and the shoe housing 3 is prevented. The oil slightly leaking from the retarding hydraulic chambers 10 and 11 to the advancing hydraulic chambers 12 and 13 passes through the oil passages 34, 35, 30, 38, 37 and the outer peripheral groove 43 from the oil 49a of the switching valve 49. Tank 45
Is discharged to

The switching valve 49a 49a is selected in FIG.
From the state shown in FIG.
When 9c is selected, the pressure oil from the pump 46 is supplied to the outer peripheral groove 4
3, is introduced into the hydraulic chamber 24 through the advance hydraulic chambers 12 and 13 and the oil passage 25 via the oil passages 37, 38, 30, 34 and 35, and the retarded hydraulic chambers 10 and 11 and the hydraulic chamber 23 are introduced.
Is opened to the oil tank 45. At this time, since the hydraulic pressure in the hydraulic chamber 23 drops to almost atmospheric pressure, the stopper piston 7 tries to return to the stopper hole 20 by the spring 18,
The hydraulic pressure in the hydraulic chamber 24 is the end surface 7d of the stopper piston 7.
Thus, the stopper piston 7 remains pushed into the accommodation hole 8 toward the chain sprocket 1 side against the biasing force of the spring 18. Therefore, the hydraulic pressure in the advance hydraulic chambers 12 and 13 acts on the side surfaces of the vanes 9a and 9b, and the vane rotor 9
Rotates clockwise with respect to the shoe housing 3, that is, advances the valve timing of the camshaft 2. When the vane rotor 9 rotates with respect to the shoe housing 3, the distal end portion 7c of the stopper piston 7 and the stopper hole 20 of the front plate 4 are displaced from each other in the circumferential direction, so that the stopper piston 7 does not fit into the stopper hole 20. FIG. 7 shows a state in which the vane rotor 9 is most advanced with respect to the shoe housing 3. When 49a of the switching valve 49 is selected from the state of FIG. 7, the vane rotor 9 rotates counterclockwise, that is, in the retard direction with respect to the shoe housing 3 when viewed from the X direction of FIG. 1, and the valve timing of the camshaft 2 is delayed. To be done. If the switching valve 49b is selected while the vane rotor 9 is rotating in the advance direction or the retard direction with respect to the shoe housing 3, the oil in the retard hydraulic chambers 10, 11 and the advance hydraulic chambers 12, 13 will flow in. And the outflow is blocked, and the vane rotor 9 is held at the intermediate position, so that the desired valve timing can be obtained. As described above, the stopper piston 7 is fitted into the stopper hole 20 of the front plate 4 when the vane rotor 9 is at the most retarded position with respect to the shoe housing 3 and pressure oil is not introduced, and the pressure oil is When it is introduced, it will not fit into the stopper hole 20.

In the first embodiment of the present invention described above, the wedge contact effect of the tapered surfaces of the stopper hole 20 and the stopper piston 7 enhances the direct contact between the housing member and the vane member. The housing member and the vane member can be firmly restrained while the housing member and the vane member are coaxially aligned. Further, since the tip end portion 7c of the stopper piston 7 is tapered so that the stopper piston 7 can be displaced in the axial direction thereof, even if there is a positional deviation between the stopper piston 7 and the stopper hole 20 due to a manufacturing error, the stopper piston 7 can be removed. Stopper hole 20
Can be securely fitted.

(Second Embodiment) A second embodiment of the present invention is shown in FIG.
And FIG. In the second embodiment, a stopper piston 50 is used instead of the stopper piston 7 as the contact portion of the first embodiment, and a guide ring 51 is housed inside the vane 9a instead of the guide ring 19. In addition, the same components as those in the first embodiment are designated by the same reference numerals. FIG.
Shows a state in which the stopper piston 50 is fitted in the stopper hole 20 of the front plate 4, and FIG. 10 shows a state in which pressure oil is introduced into the hydraulic chamber 23 and the stopper piston 50 comes out of the stopper hole 20.

The stopper piston 50 comprises a small diameter portion 50a, a medium diameter portion 50b and a large diameter portion 50c, and the guide ring 51 comprises a small inner diameter portion 51a and a large inner diameter portion 51b. The guide ring 51 is fixed to the vane rotor 9 by press fitting or the like, and the stopper piston 50 is slidable with respect to the guide ring 51. Stopper piston 50
The outer peripheral walls of the small diameter portion 50a and the medium diameter portion 50b and the inner peripheral wall of the guide ring 51 form a substantially sealed annular damper chamber 52 which is a fluid damper.

As shown in FIG. 9, the vane rotor 9 is at the most retarded position with respect to the shoe housing 3 in a state in which pressure oil is not yet supplied from the pump 46 to the hydraulic chamber 23 or 24 immediately after the engine is started, and the stopper is used. The piston 50 is fitted into the stopper hole 20 by the urging force of the spring 18, and connects the front plate 4 and the vane rotor 9.

From the state shown in FIG. 9, 49 of the switching valve 49
When a is selected, pressure oil is supplied to the hydraulic chamber 23, and
The stopper piston 50 comes out of the stopper hole 20 as shown in FIG. 9 and 10 both show the vane rotor 9 in the most retarded position with respect to the shoe housing 3. When pressure oil is supplied to the hydraulic chamber 23, the damper chamber 52 is filled with oil through a fitting clearance between the stopper piston 50 and the guide ring 51.

From the state shown in FIG. 10, when 49c of the switching valve 49 is selected to rotate the vane rotor 9 in the advancing direction with respect to the shoe housing 3, even if the switching valve 49 is switched, the hydraulic chamber 24 of the hydraulic chamber 24 is switched. There is a slight time delay until the hydraulic pressure reaches a predetermined value. Then spring 1
The stopper piston 50 is moved to the stopper hole 2 by the urging force of
It may move in the direction of fitting to zero. Even if the stopper piston 50 tries to move in the fitting direction with the stopper hole 20, the oil in the damper chamber 52 is discharged little by little from the fitting clearance, so that the moving speed of the stopper piston 50 in the fitting direction is moderated. Damper room 52
Works. Therefore, the hydraulic pressure in the hydraulic chamber 24 reaches a predetermined value before the stopper piston 50 is fitted in the stopper hole 20, so that the stopper piston 50 does not fit in the stopper hole 20 and the vane rotor 9 for the shoe housing 3 is hydraulically applied. The relative rotation control of can be continued.

In the second embodiment, it is ensured that the stopper piston 50 is momentarily pushed into the stopper hole 20 during the transitional period in which the vane rotor 9 moves in the advancing direction from the state where the vane rotor 9 is in the most retarded position with respect to the shoe housing 3. Can be prevented. As another embodiment of the present invention, in the first or second embodiment, the hydraulic chamber 23 is communicated with the advance hydraulic chambers 12 and 13, and the hydraulic chamber 24 is connected to the retard hydraulic chamber 10,
Even when communicating with 11, the same effect as that of the first or second embodiment can be obtained.

(Third Embodiment) FIG. 1 shows a third embodiment of the present invention.
1 and FIG. The configuration other than the shape of the stopper hole 60 shown in FIGS. 11 and 12 is substantially the same as that of the first embodiment. FIG. 11 shows a fitting state of the stopper piston 7 and the stopper hole 60 in the radial direction of the camshaft. The outer peripheral surface of the stopper piston 7 and the inner peripheral surface of the fitting hole 60 are in contact with each other on the front side of the drawing. Touching.

As shown in FIG. 12, the cross section of the stopper hole 60 is formed in the shape of a long hole in the vertical direction of FIG. 12, that is, in the radial direction of the front plate 4. Therefore,
The stopper hole 60 as the contacted portion is an elliptical shape along the central axis 60c extending in the radial direction, and the inner peripheral surface thereof is formed in a tapered shape. The outer peripheral surface of the tip portion 7c of the stopper piston 7 serving as the contact portion is formed in a tapered tapered circular cross section.

Further, the position of the stopper piston 7 and the position of the stopper hole 60 are the same as those in the first embodiment when these parts are located when the shoe housing 3 and the vane rotor 9 are at the most retarded position as the restraining position. The shoe housing 3 and the vane rotor 9 are firmly restrained because they are designed to be pressed against each other. Further, since the stopper hole 60 is formed in an oval shape in the radial direction, when the stopper piston 7 is fitted in the stopper hole 60, the tapered surfaces in the radial direction of both of them come into contact with each other to urge the front plate 4 in the radial direction. Is prevented. As a result, biased force is prevented from being applied to the sliding portion between the front plate 4 and the cylindrical protruding portion 5 whose clearance is designed to be as small as possible, and uneven wear is prevented. Similarly, radial displacement is prevented from occurring between the housing member such as the front plate 4 and the vane member such as the vane rotor 9, and uneven wear between both members as well as between both members is prevented. Prevention of the deterioration of the sealing property is achieved.

As described above, in the third embodiment, even when the force for firmly restraining the housing member and the vane member is generated,
Since the stopper hole 60 has an oval shape in the radial direction and the contact between the stopper piston 7 and the stopper hole 60 is limited to the rotating direction of the vane rotor 9, unnecessary force in the radial direction is generated between the housing member and the vane member. It can be prevented from acting. Therefore, the housing member and the vane member can be firmly restrained while the housing member and the vane member are coaxially aligned.

(Fourth Embodiment) A fourth embodiment of the present invention is shown in FIG.
3 and FIG. Components substantially the same as those in the first embodiment are denoted by the same reference numerals. In the fourth embodiment, instead of the drain hole 21 provided in the side wall of the vane 9a on the side of the chain sprocket 1 and the atmospheric hole 22 provided in the chain sprocket 1 in the first embodiment, a drain hole 71 is provided in the outer peripheral wall of the vane 9a. An air hole 72 is provided on the outer peripheral wall of the shoe housing 3.
Is provided. The drain hole 71 and the atmosphere hole 72 communicate with each other to form a communication hole, and the chain sprocket 1
The back pressure chamber 8a which is the accommodation hole 8 on the side can be opened to the atmosphere.
The volume of the back pressure chamber 8a decreases as the stopper piston 7 moves to the right in FIG. 13, that is, in the direction of releasing the restraint between the shoe housing 3 and the vane rotor 9, and the stopper piston 7
Increases when moving in the left direction in FIG. 13, that is, in the direction of restraining the shoe housing 3 and the vane rotor 9.

As shown in FIG. 13, when the vane rotor 9 is at the most retarded position with respect to the shoe housing 3 and the hydraulic oil is not supplied to the hydraulic chambers 23 and 24, the stopper piston 7 is fitted into the stopper hole 20. The drain hole 71 and the atmosphere hole 72 are in substantially the same position and communicate with each other. FIG.
When pressure oil is supplied to the hydraulic chamber 23 from the state shown in FIG.
As shown in FIG. 4, the stopper piston 7 comes out of the stopper hole 20, and the drain hole 71 is closed by the outer wall of the large-diameter portion 7b, so that the back pressure chamber 8a is cut off from communication with the atmosphere.
13 and 14 both show the vane rotor 9 in the most retarded position with respect to the shoe housing 3.

When the vane rotor 9 is rotated in the advancing direction with respect to the shoe housing 3 from the state shown in FIG. 14, even if the switching valve (not shown) is switched, the hydraulic pressure in the hydraulic chamber 24 is slightly reduced to a predetermined value. Time delay will occur. At this time, even if the stopper piston 7 tries to move in the direction in which the stopper piston 7 is fitted into the stopper hole 20 by the urging force of the spring 18, the back pressure chamber 8a is blocked from communicating with the atmosphere and is sealed, so that the stopper piston 7 is fitted. The moving speed in the direction is reduced. Therefore, the hydraulic pressure in the hydraulic chamber 24 reaches a predetermined value before the stopper piston 7 is fitted into the stopper hole 20, so that the stopper piston 7 is stopped.
It is possible to start the advance angle rotation of the vane rotor 9 with respect to the shoe housing 3 by hydraulically engaging without fitting.

In the above-described embodiment of the present invention described above, both the tip end portion of the stopper piston and the stopper hole are formed with tapered surfaces, but only one of them may be tapered surface. For example, one may be formed as a tapered surface and the other may be formed as a spherical surface that can slide on the tapered surface. Further, since it is important to have a slope in order to generate the biasing force in the rotation direction due to the wedge effect, the stopper hole is formed in a shape having a slope only on at least one side in the rotation direction, for example, only on the advance side. You may.

In the above embodiment, the most retarded position is the restraining position, and the shoe 9a has the stopper 9e as shown in FIG.
However, the stopper portion 9e on the most retarded angle side may be provided on the left side of the vane 9a in FIG. 2 and brought into contact with the shoe 3b. Even in this case, a force for pressing the vane rotor 9 against the shoe housing 3 can be obtained by the contact between the stopper piston and the stopper hole on the tapered side surface on the advance side, and both can be firmly restrained.

Further, in the above-mentioned embodiment, the stopper piston and the stopper hole are designed to abut only on one advance side of the vane rotor rotation direction, that is, only on the opposite side of the restraint position, and the turning force by the wedge effect is generated. Although the housing member and the vane member are configured to be restrained by the above, the stopper piston and the stopper hole contact each other in both the rotating direction, and the housing member and the vane member are contacted only by the contact between the stopper piston and the stopper hole. You may restrain and. In this case, the stopper piston requires high strength. Also in this case, it is desirable that the stopper hole is formed in an oval shape in the radial direction and the contact of the tapered surface is limited to only the side surface in the rotation direction.

In the above embodiment, the taper angle of the stopper piston and the taper angle of the stopper hole are the same. The angle need not be the same. In the above embodiment, the chain sprocket is rotated together with the crankshaft serving as the drive shaft, the shoe housing serving as a housing member fixed thereto is rotated together with the crankshaft, and the vane rotor is rotated together with the camshaft serving as the driven shaft. It is also possible to rotate the chain sprocket with the camshaft and rotate the vane rotor with the crankshaft. In this case, the vane rotor is restrained at the most advanced position with respect to the shoe housing.

Further, in the above embodiment, in the engine in which the two camshafts for opening and closing the intake valve and the camshaft for opening and closing the exhaust valve are provided in parallel, the valve timing adjusting device is arranged between the two camshafts. You may intervene. For example, in the case where one camshaft that is rotated from a crankshaft in synchronization by a chain or the like is a drive shaft and the other camshaft is a driven shaft by a transmission device such as a gear, one vane rotor is one of the drive shafts. The housing member may be rotated together with the shaft, and the housing member may be rotated together with the other cam shaft, which is the driven shaft, or vice versa.

In the above embodiment, two vanes are provided on the vane rotor, but the number of vanes may be one or three or more.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line II of FIG. 2 showing a valve timing adjusting device according to a first exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a valve timing adjusting device according to a first embodiment of the present invention.

3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a vertical cross-sectional view showing a state where the stopper piston of the first embodiment is pulled out from the stopper hole.

FIG. 6 is a vertical cross-sectional view showing a state in which the vane rotor has rotated in the advance direction with respect to the shoe housing of the first embodiment.

7 is a cross-sectional view showing the first embodiment in the state of FIG.

FIG. 8 is a schematic diagram showing a hydraulic circuit of the first embodiment.

FIG. 9 is a vertical sectional view showing a valve timing adjusting device according to a second embodiment of the present invention.

FIG. 10 is a vertical cross-sectional view showing a state where the stopper piston of the second embodiment is pulled out from the stopper hole.

FIG. 11 is a sectional view showing a fitted state of a stopper piston and a stopper hole of the third embodiment.

12 is a sectional view taken along line XII-XII of FIG.

FIG. 13 is a vertical sectional view showing a valve timing adjusting device according to a fourth embodiment of the present invention.

FIG. 14 is a vertical cross-sectional view showing a state in which the stopper piston of the fourth embodiment is pulled out from the stopper hole.

[Explanation of symbols]

 1 chain sprocket (housing member) 2 cam shaft (driven shaft) 3 shoe housing (housing member) 3a, 3b shoe 4 front plate (housing member) 7 stopper piston (abutting part) 7c tip part 8a back pressure chamber 9 vane rotor ( Vane member 9a, 9b Vane 20 Stopper hole (contacted part) 46 Pump (driving means) 49 Switching valve (driving means) 50 Stopper piston (contacting part) 60 Stopper hole (contacted part)

Claims (11)

[Claims] 1. A drive force transmission system for transmitting a drive force from a drive shaft of an internal combustion engine to a driven shaft that opens and closes at least one of an intake valve and an exhaust valve of the internal combustion engine, the drive shaft or the driven shaft. And a housing member that rotates together with one of the drive shaft and the driven shaft, and a relative rotation with respect to the housing member within the housing chamber formed in the housing member within a predetermined angle range. A vane member that can be accommodated, and a contact portion that is provided on the housing member and the vane member, respectively, and abuts each other to restrain the rotational movements of the housing member and the vane member at a predetermined restraint position. And a contacted portion, the restraint state can be released by displacement of the contacted portion, and the contacted portion is attached in a contacting direction to the contacted portion. Restraining means including a biasing means for releasing the restraint between the housing member and the vane member by displacing the contact portion against the biasing means by a fluid pressure, and the housing member by a fluid pressure And a fluid drive type drive means for rotating the vane member relative to each other, and a valve timing adjustment device for an internal combustion engine, comprising: 2. The valve timing adjusting device for an internal combustion engine according to claim 1, wherein the abutting portion is displaced along a rotation axis direction of the housing member. 3. The housing member and the vane member are configured to directly contact each other in the rotation direction at the restrained position, and the housing member and the vane member are pressed against each other in a contacting direction. 3. The internal combustion engine according to claim 1, wherein an inclined surface for rotating the housing member and the vane member is formed on at least one of the contact portion and the contacted portion. Valve timing adjustment device. . 4. The stopper piston, which is displaceably accommodated in the vane member, is provided as the abutting portion, and the stopper piston is formed in the housing member facing the vane member as the abutted portion. 4. The valve timing adjusting device for an internal combustion engine according to claim 3, further comprising a stopper hole to be fitted, wherein at least one of the stopper piston and the stopper hole has a tapered surface as the inclined surface. 5. The valve timing adjusting device for an internal combustion engine according to claim 4, wherein the stopper hole is formed in an elongated hole shape that is long in a radial direction of the housing member. 6. The stopper piston, which is displaceably accommodated in the vane member, is provided as the abutting portion, and the stopper piston is formed in the housing member facing the vane member as the abutted portion. The valve timing adjusting device for an internal combustion engine according to claim 1 or 2, further comprising a stopper hole for fitting, wherein a surface of a fitting portion of at least one of the stopper piston and the stopper hole is a tapered surface. 7. The restraint between the housing member and the vane member is released in a state where the stopper piston is housed in the vane member.
Alternatively, the valve timing adjusting device for an internal combustion engine according to item 6. 8. Between the contact portion and the contacted portion,
A fluid damper for reducing a displacement speed of the contact portion is formed by an internal working fluid.
7. The valve timing adjusting device for an internal combustion engine according to claim 7. 9. The abutting portion has a back pressure chamber whose volume is reduced in accordance with the displacement of the abutting portion in the restraint releasing direction, and the abutting portion has a back pressure chamber of the back pressure chamber in the restraint releasing state. 9. The valve timing adjusting device for an internal combustion engine according to claim 1, wherein the communication hole with the outside is closed. 10. The abutting portion and the abutted portion are configured to abut when the driven shaft is in the most retarded state in which the driven shaft is most retarded. 9. The valve timing adjusting device for an internal combustion engine according to claim 9. 11. The abutting portion has first and second pressure receiving surfaces for releasing the constraint between the housing member and the vane member in response to a fluid pressure supplied from the driving means, and the first and second pressure receiving surfaces. A first fluid pressure supplied from the driving means acts on the pressure receiving surface so as to relatively rotate the vane member in the advance direction with respect to the housing member, and
The second fluid pressure supplied from the drive means acts on the pressure receiving surface so as to relatively rotate the vane member with respect to the housing member in a retard angle direction. The valve timing adjustment device for an internal combustion engine according to any one of 1 to 10.