JP3873466B2 - Valve timing control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vane type valve opening / closing timing control device used for controlling the opening / closing timing of an intake valve or an exhaust valve in a valve operating apparatus for an internal combustion engine.
[0002]
[Prior art]
As one of the conventional valve opening / closing timing control devices of this type, a rotating member that rotates together with one of a crankshaft or a camshaft of an internal combustion engine, and a crankshaft or camshaft that is mounted on the rotating member so as to be relatively rotatable within a predetermined range. A rotation transmission member that rotates together with the other of the rotation member, a vane provided on the rotation member, a rotation advancement chamber and a retard angle formed by the vane formed between the rotation transmission member and the protrusion provided on the rotation transmission member and the rotation member. There is a fluid pressure chamber divided into a chamber, a first fluid passage for supplying and discharging fluid to the advance chamber, and a second fluid passage for supplying and discharging fluid to the retard chamber, For example, it is disclosed in JP-A-1-92504 and JP-A-9-250310.
[0003]
According to this valve opening / closing timing control device, the working fluid is supplied to the advance angle chamber via the first fluid passage, and the working fluid is discharged from the retard angle chamber via the second fluid passage. In addition, the rotation transmitting member relatively rotates in one direction, the rotation phase of the camshaft is advanced with respect to the rotation phase of the crankshaft, and the opening / closing timing of the valve driven by the camshaft is advanced. On the contrary, by supplying the working fluid to the retardation chamber through the second fluid passage and discharging the working fluid from the advance chamber through the first fluid passage, the rotation member and the rotation transmission member are moved in the other direction. The rotation phase of the camshaft is delayed relative to the rotation phase of the crankshaft, and the opening / closing timing of the valve driven by the camshaft is delayed.
[0004]
[Problems to be solved by the invention]
In the above-described conventional apparatus, the fluid pressure applied to the advance chamber and the retard chamber is linearly controlled, and the relative phase between the rotating member and the rotation transmitting member can be controlled and maintained at an arbitrary relative phase. For example, when the rotation phase of the camshaft is advanced to the maximum with respect to the rotation phase of the crankshaft (at the most advanced angle), the vane shows the relative phase of the rotation transmission member and the rotation phase of the protrusion of the rotation transmission member. There is a case where the phase is set before the relative phase in contact with the end surface on the retarding angle chamber side and is held by the fluid pressure applied to the advance angle chamber and the retard angle chamber.
[0005]
By the way, fluctuating torque always acts on the camshaft during operation of the internal combustion engine, and this fluctuating torque is transmitted to a rotating member or a rotation transmitting member that rotates together with the camshaft. Therefore, as described above, when the relative phase between the rotation member and the rotation transmission member at the most advanced angle is set before the relative phase at which the vane contacts the retardation chamber side end surface of the projection of the rotation transmission member. Indicates that the rotating member and the rotation transmitting member rotate relative to each other by the fluctuating torque against the holding force by the fluid pressure applied to the advance chamber and the retard chamber, and the vane forms the retard chamber side end surface of the protrusion. There was a possibility that a large hitting sound was generated by collision with the vane and the vane and the protrusion were damaged.
[0006]
These problems can be solved by sticking a buffer member to the side surface of the vane and the projecting end surface of the rotation transmitting member with which the side surface abuts, as disclosed in Japanese Patent Application Laid-Open No. 10-141021. However, according to this means, the number of parts increases, and the manufacturing cost of the valve opening / closing timing control device increases.
[0007]
Therefore, an object of the present invention is to buffer the collision between the vane and the protrusion with a simple configuration without increasing the manufacturing cost in the valve opening / closing timing control device.
[0008]
[Means for Solving the Problems]
The technical means of the present invention taken in order to solve the above problems includes a rotating member that rotates together with one of a crankshaft and a camshaft of an internal combustion engine, and the crankshaft that is mounted on the rotating member so as to be relatively rotatable within a predetermined range. and a rotation transmitting member that rotates together with the other cam shaft, wherein a vane provided on the rotating member, is formed between the rotation transmission member and the rotating member and projections provided on said rotation transmitting member and the vane A fluid pressure chamber divided into an advance angle chamber and a retard angle chamber by means of a first fluid passage, a first fluid passage for supplying and discharging fluid to the advance angle chamber, and a second fluid supplying and discharging fluid to the retard angle chamber. A fluid passage, and the rotating member and the rotation transmitting member rotate relative to each other by fluid pressure applied to the advance chamber and the retard chamber, and the camshaft with respect to the rotational phase of the crankshaft. In the valve timing control apparatus for changing opening and closing timing of valves driven by the camshaft by rotating the phase is allowed to change the bets, the retarded angle chamber side end face of the projection of the vanes the rotation transmission member Alternatively, the retard chamber and the second fluid passage communicate or advance at a predetermined relative phase that is a predetermined angle before a relative phase between the rotating member and the rotation transmitting member when contacting the advance angle chamber side end surface. The communication between the corner chamber and the first fluid passage is blocked.
[0009]
According to the above-described means, for example, the relative phase between the rotation member and the rotation transmission member at the most advanced angle is set before the relative phase in which the vane contacts the retarding chamber side end surface of the protrusion of the rotation transmission member. When the fluid pressure is applied to the advance chamber and the retard chamber, the fluid pressure applied to the advance chamber and the retard chamber is caused by the fluctuation torque acting on the camshaft. Even if the rotating member and the rotation transmitting member rotate relative to the holding force, the communication between the second fluid passage and the retarding chamber is blocked before the vane comes into contact with the retarding chamber side end surface of the protrusion. Thus, the relative speed between the rotating member and the rotation transmitting member is reduced. As a result, the collision between the vane and the end face of the retarding chamber is avoided, and in the unlikely event of a collision, the collision is buffered to prevent generation of a loud sound and damage to the vane and the projection. The
[0010]
In the above-mentioned means, the second fluid passageway at a predetermined relative phase that is a predetermined angle before a relative phase between the rotation member and the rotation transmission member when the vane contacts the end surface on the retarding chamber side of the protrusion. The retardation chamber side opening may be closed by the protrusion, and the vane may be brought into contact with the retardation chamber side end surface of the protrusion at the radially inner edge thereof.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a valve timing control apparatus according to the present invention will be described with reference to the drawings.
[0012]
In FIG. 1, an exhaust valve camshaft (hereinafter referred to as a first camshaft) 2 and an intake valve camshaft (hereinafter referred to as a second camshaft) 2 rotatably supported by a cylinder head 1 of an internal combustion engine E. 3, a gear 4 that is mounted on the outer periphery of the first camshaft 2 so as to be relatively rotatable and a gear 5 that is mounted on the outer periphery of the second camshaft 3 so as not to be relatively rotatable mesh with each other. The power transmission means 6 is connected.
[0013]
The timing pulley 7 is fastened to the first camshaft 2 by a bolt 8 screwed to the end of the first camshaft 2 protruding from the cylinder head 1, and a crank pulley and timing belt (not shown) are connected to the crankshaft 48. 49. In FIG. 1, reference numeral 9 denotes a stopper pin that is press-fitted and fixed to the end portion of the first camshaft 2 and serves to prevent the timing pulley 7 from rotating.
[0014]
The cylindrical portion 10 of the first camshaft 2 extending into the cylinder head 1 is composed of a male screw portion 11 and a portion in which the annular grooves 12 and 13 are formed from the front side, and from the portion in which the annular grooves 12 and 13 are formed. A journal portion 14 on which the gear 4 is rotatably supported is formed on the rear side, and a cam 15 is formed on the rear side of the journal portion 14.
[0015]
Thus, a valve opening / closing timing control mechanism 16 serving as a main body of the valve opening / closing timing control device is mounted on the portion where the annular grooves 12 and 13 are formed. As shown in FIG. 2, the valve opening / closing timing control mechanism 16 has one end fitted into an inner rotor 17 (rotating member) and four radial grooves formed on the outer periphery of the inner rotor 17 and the other end extending radially. Four vanes 18 and the inner rotor 17 are disposed so as to surround the inner rotor 17, and the inner peripheral surface of the four projecting portions 19 </ b> A projecting radially inwardly on the inner peripheral portion of the four vanes 18 is formed on the outer peripheral surface of the inner rotor 17. An outer rotor 19 (rotation transmission member) that slides densely and rotatably accommodates vanes 18 in recesses formed between adjacent protrusions 19A, and an inner rotor 17, as shown in FIG. The vane 18 and the outer rotor 19 are sandwiched in the axial direction, and a front plate 21 and a rear plate 22 that form a pressure chamber (fluid pressure chamber) with the inner rotor 17 in the recess are formed. The front plate 21, the rear plate 22, and the external rotor 19 are integrated with the gear 4 by bolts 23, and the front plate 21 and the rear plate 22 are liquid-tightly pressed against the side surfaces of the external rotor 19 and the internal rotor. Each of the 17 side surfaces can be slid in a liquid-tight manner. The other end of each vane 18 extends in the radial direction in each pressure chamber so as to be in fluid-tight sliding contact with the outer peripheral surface of the recess. Each vane 18 causes each pressure chamber to be retarded from the advance chamber 31. Divided into chambers 30 and 30a. The inner peripheral portion 22 a of the rear plate 22 has an inner diameter that is larger than the diameter of the journal portion 14 and smaller than the diameter of a circle connecting the inner ends of the radial grooves formed in the inner rotor 17. Further, the inner peripheral portion of the front plate 21 has an inner diameter smaller than the diameter of a circle connecting the inner ends of the radial grooves.
[0016]
The valve opening / closing timing control mechanism 16 described above has a nut 25 that can be brought into contact with the front side surface of the internal rotor 17 on the male screw portion 11 in a state where the rear side surface of the internal rotor 17 is in contact with the front side surface of the journal portion 14. By being fastened, the internal rotor 17 is clamped between the nut 25 and the journal portion 14, so that the inner rotor 17 is attached to the first camshaft 2 so as not to move in the axial direction. As shown in FIG. 1, a knock pin 32 is press-fitted and fixed radially in the annular groove 13 on the outer periphery of the inner rotor 17, and the outer end of the knock pin 32 is a rear surface of the inner peripheral surface of the inner rotor 17. It is inserted into an engagement groove 33 formed on the side in the axial direction. As a result, the outer end of the knock pin 32 is engaged with the engagement groove 33 of the internal rotor 17 in the circumferential direction, so that the valve opening / closing timing control mechanism 16 is attached to the first camshaft 2 so as not to be relatively rotatable. The diameter of the knock pin 32 is smaller than the opening width (axial length) of the annular groove 13 so as not to prevent the circumferential communication of the annular groove 13.
[0017]
Each advance chamber 31 and each retard chamber 30, 30a are respectively connected to the hydraulic fluid supply / discharge device 38 including the hydraulic control valve 39 and the control device 41 through the first fluid passage and the second fluid passage. As a result, hydraulic oil is supplied and discharged. The first fluid passage includes two oil passages 27 formed in the radial direction in the first camshaft 2 so as to communicate the oil passage 27 formed in the axial center of the first camshaft 2 and the oil passage 27 and the annular groove 13. The first camshaft 2 has one end communicated with the oil passage 46, four oil passages 29 formed in the internal rotor 17 so as to communicate with the annular groove 13 and each advance angle chamber 31, and the oil passage 27. The other end of the oil passage 47 is connected to the A port of the hydraulic control valve 39 via an annular groove 44 formed in the cylinder head 1. The second fluid passage has a diameter in the first camshaft 2 so that the two oil passages 26 formed on the oil passage 27 in the first camshaft 2 are axially connected, and the oil passage 26 and the annular groove 12 communicate with each other. And two oil passages 45 formed in the direction, and four oil passages 28 and 28a formed in the inner rotor 17 so as to communicate the annular groove 12 with each retarding angle chamber 30 and 30a. Is connected to the B port of the hydraulic control valve 39 through an annular groove 43 formed on the outer periphery of the first camshaft 2. In FIG. 1, reference numeral 34 denotes a ball press-fitted to close the opening of the passage 27, and 35 denotes a ball press-fitted to block the passage 27 from other passages. In FIG. 2, reference numeral 50 denotes a known lock mechanism that holds the relative phase between the internal rotor 17 and the external rotor 19 at the maximum retarded relative phase shown in FIG.
[0018]
The hydraulic control valve 38 can move the spool inserted in the housing in the axial direction so as to be movable in the axial direction by energizing the solenoid against the spring, and can move to the right in FIG. The P port connected to the oil pump 40 driven by the B communicates with the B port, the R port connected to the reservoir 42 communicates with the A port, and the P port communicates with the A port when energized. The B port communicates with the R port. For this reason, when the solenoid of the hydraulic control valve 38 is not energized, hydraulic oil is supplied to the retard chambers 30 and 30a via the second fluid passage, and for each advance angle via the first fluid passage when the solenoid is energized. The hydraulic oil is supplied to the chamber 31, and the current supply to the solenoid is duty-controlled by the control device 41.
[0019]
In the above configuration, when the first camshaft 2 is driven by the timing pulley 7 to which the rotational power of the crankshaft 48 is transmitted, an exhaust valve (not shown) is driven to open and close by the first camshaft 2, and the first camshaft is driven. 2 is transmitted to the gear 4 via the internal rotor 17, the vane 18, the external rotor 19 and the bolt 23, and further transmitted to the second camshaft 3 via the gear 4 and the gear 5. An intake valve (not shown) is driven to open and close.
[0020]
The supply and discharge of the hydraulic fluid to each advance chamber 31 and each retard chamber 30, 30a is controlled by duty control of the control position of the hydraulic control valve 39 by the control device 41 as described above. Therefore, by controlling the hydraulic control valve 39 so that the hydraulic pressure in each advance angle chamber 31 is higher than the hydraulic pressure in each retard angle chamber 30, 30a, the gear 4 together with the external rotor 19 and the internal rotor 17 and 2 rotates clockwise with respect to the first camshaft 2, and the relative phase of the second camshaft 3 with respect to the first camshaft 2 (the rotational phase of the second camshaft 3 with respect to the rotational phase of the crankshaft 48) is set. Can advance. Conversely, by controlling the hydraulic pressure control valve 39 so that the hydraulic pressure in each retarding angle chamber 30, 30a is higher than the hydraulic pressure in each advance angle chamber 31, the gear 4 together with the external rotor 19 17 and the first camshaft 2 can rotate counterclockwise in FIG. 3 to delay the relative phase of the second camshaft 3 with respect to the first camshaft 2. The relative phase of the second camshaft 3 with respect to the first camshaft 2 can be maintained at an arbitrary phase by duty control of the hydraulic control valve 39.
[0021]
In this embodiment, as shown in FIG. 2, the relative phase of the second camshaft 3 with respect to the first camshaft 2 toward the retard side is one vane (upper right vane in FIG. 2) 18 as its internal rotor. 17 is restricted by contacting the advance angle chamber side end surface 19a of the projecting portion 19A at the radially inner edge portion of the portion projecting from the outer periphery of 17. Advancing chamber side end surface 19a that abuts the vane 18 and extends radially inward to the outer periphery of the internal rotor 17 is formed with a communication groove 19b extending in the radial direction, and the inner periphery of the protrusion 19A. The circumferential groove 19c formed in the portion ensures communication between the advance chamber 31 (upper right advance chamber in FIG. 2) and the oil passage 29 when the vane 18 abuts. In the present embodiment, the relative phase of the second camshaft 3 to the advance side with respect to the first camshaft 2 is such that the vane 18 is on the retarding chamber side end face of the projection 19A as shown in FIG. Before the abutting relative phase, the vane 18 is held by the pressure of the hydraulic oil applied to each advance chamber 30 and retard chamber 31 without contacting the retard chamber side end surface. It has come to be.
[0022]
By the way, the first and second camshafts 2 and 3 are constantly subjected to fluctuating torque during operation of the internal combustion engine, and this fluctuating torque is applied to the internal rotor 17 and the vane 18 that rotate integrally with the first camshaft 2. It is transmitted and acts against the holding force by the hydraulic pressure applied to each advance angle chamber 30 and each retard angle chamber 31. For this reason, at the time of the relative phase at the most advanced angle, the internal rotor 17 and the external rotor 19 may rotate relative to the advance side and the retard side against the holding force by the hydraulic pressure due to the fluctuation torque. In this embodiment, at the relative phase at the most advanced angle shown in FIG. 3, the internal rotor 17 rotates relative to the external rotor 19 by an angle that is counterclockwise due to the fluctuating torque as shown in FIG. 4. (In FIG. 4, when the lower right vane 18 comes into contact with the retardation chamber side end surface 19d of the projection 19A, the relative phase of the internal rotor 17 and the external rotor 19 becomes a predetermined relative phase before a predetermined angle). The opening of the oil passage 28a to the retard chamber 30a (lower right retard chamber in FIG. 4) is closed by the protrusion 19A, so that the retard chamber 30a is sealed. Further, the retarding chamber side end surface 19d of the projecting portion 19A extends radially inward to the outer periphery of the internal rotor 17, and as shown in FIG. When the relative rotation is further made counterclockwise, one vane (lower right vane in FIG. 5) 18 is used to advance the protrusion 19A at the radially inner edge of the portion where the inner rotor 17 protrudes from the outer periphery. It contacts the chamber side end surface 19a.
[0023]
Therefore, in the present embodiment, the internal rotor 17 resists the holding force by the hydraulic pressure applied to each advance angle chamber 31 and each retard angle chamber 30, 30a by the fluctuating torque acting on the first camshaft 2. Even if the outer rotor 19 and the external rotor 19 are further rotated relative to the advanced angle from the relative phase at the most advanced angle, the vane (lower right vane in FIG. 4) 18 contacts the retarding chamber side end surface 19d of the projection 19A. Before the contact, the communication between the oil passage 28a and the retarding chamber 30a is blocked, so that the relative speed between the internal rotor 17 and the external rotor 19 is reduced. As a result, the collision between the vane 18 and the retarding chamber side end surface 19d of the projection 19A is avoided without using a separate member, and in the unlikely event of a collision, the collision is buffered and a large hitting sound is generated. Further, damage to the vane 18 and the protrusion 19A due to the collision is prevented. Furthermore, the vane (lower right vane in FIG. 4) 18 has an advance angle chamber side end surface 19a of the protrusion 19A at the radially inner edge of the portion protruding from the outer periphery of the inner rotor 17 as shown in FIG. Therefore, it is possible to prevent a large stress from acting on the radially inner edge of the vane 18 at the time of contact, and to prevent the vane 18 from being damaged more accurately.
[0024]
In the above-described embodiment, the present invention is applied to the valve opening / closing timing control device in which the vane 18 is provided separately from the internal rotor 17. However, in the present invention, the vane is thick in the circumferential direction and integrated with the internal rotor. The valve opening / closing timing control device provided in the above can be similarly implemented. In the above-described embodiment, the inner rotor 17 is attached to the first camshaft 2 connected to the crankshaft 48 so as not to be relatively rotatable, and the outer rotor 19 is externally mounted on the inner rotor 17 so as to be relatively rotatable within a predetermined range. Although the present invention has been implemented in the valve timing control apparatus configured to be coupled to the second camshaft 3 via the power transmission means 6, the present invention connects the external rotor to the crankshaft and the camshaft. The present invention can be similarly applied to a valve opening / closing timing control device that is mounted on an internal rotor that is mounted so as not to be relatively rotatable so as to be relatively rotatable within a predetermined range.
[0025]
【The invention's effect】
As described above, according to the present invention, for example, the relative phase between the rotation member and the rotation transmission member at the most advanced angle is set to be larger than the relative phase at which the vane contacts the retarding chamber side end surface of the protrusion of the rotation transmission member. If the fluid pressure applied to the advance angle chamber and the retard angle chamber is set in advance and is held by the fluid pressure, it is applied to the advance angle chamber and the retard angle chamber by the fluctuating torque acting on the camshaft. Even if the rotating member and the rotation transmitting member rotate relative to the holding force due to the fluid pressure, the second fluid passage and the retarding angle are used before the vane contacts the retarding chamber side end surface of the projecting portion of the rotation transmitting member . Since the communication between the chambers is blocked, the relative speed between the rotating member and the rotation transmitting member is reduced. Thereby, without using a separate member, it is possible to avoid a collision between the vane and the end face on the retarding chamber side of the projection of the rotation transmission member, and it is possible to buffer the collision in the event of a collision. Thus, it is possible to prevent the generation of a large hitting sound due to a collision and the breakage of the vane and the protrusion with a simple configuration without increasing the manufacturing cost of the valve opening / closing timing control device.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a valve timing control apparatus according to the present invention.
FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 showing a state at the most retarded angle.
3 is a cross-sectional view taken along the line AA of FIG. 1 showing a state at the most advanced angle.
FIG. 4 is a cross-sectional view taken along line AA showing a state in which the inner rotor and the outer rotor are relatively rotated toward the advance side by a predetermined angle from the most advanced angle.
5 is a cross-sectional view taken along line AA showing a state in which the inner rotor and the outer rotor are further rotated relative to the advance side from the state of FIG. 4 and one vane is in contact with the end surface of the projecting portion on the retarding angle side. is there.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylinder head 2 1st cam shaft 3 2nd cam shaft 4 Gear 12 Annular groove (2nd fluid passage)
13 annular groove (first fluid passage)
17 Internal rotor (rotating member)
18 Vane 19 External rotor (rotation transmission member)
19A Projection 19a Advance angle chamber side end surface 19d Delay angle chamber side end surface 26, 28, 28a, 45 Oil passage (second fluid passage)
27, 29, 46, 47 Oil passage (first fluid passage)
30, 30a Delay angle chamber 31 Advance angle chamber

Claims (2)

A rotating member that rotates with one of the crankshaft and camshaft of the internal combustion engine;
A rotation transmitting member that is externally mounted on the rotating member so as to be relatively rotatable within a predetermined range and rotates together with the other of the crankshaft and the camshaft;
A vane provided on the rotating member;
A fluid pressure chamber formed between the rotation transmission member and a protrusion provided on the rotation transmission member and the rotation member and divided into an advance chamber and a retard chamber by the vane;
A first fluid passage for supplying and discharging fluid to the advance chamber;
A second fluid passage for supplying and discharging fluid to the retardation chamber;
The rotation member and the rotation transmission member are relatively rotated by the fluid pressure applied to the advance chamber and the retard chamber, and the rotation phase of the camshaft is changed with respect to the rotation phase of the crankshaft. In the valve opening / closing timing control device for changing the opening / closing timing of the valve driven by the camshaft,
Said vane is the rotating member and the rotation transmitting member relative phase than the predetermined angle before a predetermined of time for contact with the retarded angle chamber side end surface or the advanced angle chamber side end face of the projection of the rotation transmission member A valve opening / closing timing control device characterized in that communication between the retard chamber and the second fluid passage or communication between the advance chamber and the first fluid passage is blocked during a relative phase.   For the retardation of the second fluid passage at a predetermined relative phase that is a predetermined angle before the relative phase of the rotation member and the rotation transmission member when the vane contacts the end surface on the retardation chamber side of the protrusion. The chamber-side opening is closed by the protrusion, and the vane can be brought into contact with the retardation chamber-side end surface of the protrusion at the radially inner edge thereof. 2. The valve opening / closing timing control device according to 1.

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