JP4035785B2 - Valve timing control device - Google Patents

Description

  The present invention relates to a 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.

  One example of this type of valve opening / closing timing control device is disclosed in Patent Document 1, for example. As shown in FIGS. 6 and 7, this device is integrated with a rotating shaft for opening and closing a valve (a camshaft 204 and a spacer 221 and a bolt 220) rotatably assembled to a cylinder head 214 of an internal combustion engine. A timing pulley 201 (rotation transmission member) that is externally rotatably mounted within a predetermined range and to which the rotational power from the crank pulley is transmitted via a timing belt. The six vanes 202 attached to the rotor 203, the inner rotor 203, the timing pulley 201, and the front plate 205 provided integrally with the timing pulley 201 are formed by the vane 202 so that the advance angle chamber 209 and the retarding chamber 209 are retarded. Six fluid pressure chambers that are divided into the corner chamber 209a, the advance chamber 209, and the retard chamber 209a Fluid selectively discharge supercharges, and a fluid supply and discharge means consisting of the inner rotor 203 and the switching valve 215 to rotate relative to the rotation transmitting member comprising a rotating shaft and the timing pulley 201, etc. made of the camshaft 204. The switching valve 215 slides the valve spool 218 in the right direction in the figure against the spring 216 by energizing the solenoid 213, and the working fluid supplied from the fluid pump by the switching valve 215 flows from the flow path 212. It is selectively supplied to the retarding angle chamber 209a or the advance angle chamber 209 via the flow path 211 and the one-way valve 207a or the flow path 210 and the one-way valve 207, respectively. As a result, the fluid pressure in the advance chamber 209 and the retard chamber 209a is appropriately adjusted, and the rotation transmission member composed of the rotation shaft composed of the internal rotor 203 and the camshaft 204, the timing pulley 201, etc. for determining the valve opening / closing timing. The relative rotation amount (relative phase amount) is adjusted and controlled.

JP-A-1-92504

  In this type of valve opening / closing timing control device, the torque for rotating the rotating shaft relative to the rotation transmitting member is obtained by multiplying the pressure receiving area of the vane by the distance from the axis of the rotating shaft to the center of the pressure receiving surface. Therefore, if the pressure receiving area of the vane is the same, the longer the distance from the axis of the rotating shaft to the center of the pressure receiving surface, the greater the torque, and the higher the operation responsiveness of the valve timing control device. .

  In the valve timing control device disclosed in the above publication, the timing pulley 201 protrudes radially inward, the inner peripheral surface thereof is in sliding contact with the outer peripheral surface of the internal rotor 203, and the fluid is transferred to the rotational direction side end surface 208. Six protrusions 201b that divide the pressure chamber in the rotation direction are formed, and each vane hits the protrusion 201c formed to protrude in the rotation direction on the radially outer side of the rotation direction end surface of each of the protrusions 201b. As a result of the contact, the relative rotation amount (θ) of the rotation transmission member including the rotation shaft including the internal rotor 203 and the camshaft 204 and the timing pulley 201 is limited. For this reason, in the most advanced angle state where the vane 202 is in contact with the projecting portion 201c in the advance direction and the most retarded state in which the vane 202 is in contact with the projecting portion 201c in the retarded direction, the pressure receiving area of the vane is limited to the radially inner side. At the same time, the distance between the center of the vane pressure receiving surface and the axis of the rotating shaft is shortened, and the torque for rotating the rotating shaft relative to the rotation transmitting member is reduced. As a result, there has been a problem that the responsiveness is lowered when the relative phase is adjusted and controlled from the most advanced angle state and the most retarded angle state.

  Therefore, an object of the present invention is to improve the operation responsiveness when the relative phase is adjusted and controlled from the most advanced angle state or the most retarded angle state in the valve timing control apparatus.

A first characteristic configuration of a valve opening / closing timing control device according to the present invention includes a rotary shaft for valve opening / closing that is rotatably assembled to a cylinder head of an internal combustion engine, and a rotary shaft that is rotatably mounted on the rotary shaft within a predetermined range. is rotational power transmission from the crankshaft, between the rotation transmitting member, a plurality of the projections and the rotating shaft and the rotation transmitting member with two or more of the projections that protrude along the rotation direction toward the rotational axis A plurality of fluid pressure chambers formed by partitioning in a rotation direction, and a vane attached to the rotation shaft so as to be divided into an advance angle chamber and a retard angle chamber for each of the plurality of fluid pressure chambers; A valve opening / closing timing control device for controlling the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, comprising a passage formed on the rotating shaft and separately supplying and discharging working fluid to and from the advance angle chamber and the retard angle chamber a is, the vanes can contact protrusions, wherein Of the end face of the over down facing the projection, provided in a part of the region including the radially inner end, upon contact between the vane and the projecting portion, radially outward than the projecting portion and the passage The point which formed the channel | path which connects the located fluid pressure chamber in the said protrusion part .

According to the above-described means, the fluid pressure chamber is partitioned by the protrusion in the rotation direction, and the protrusion capable of contacting the vane is the radially inner end of the end face of the protrusion facing the vane. Ru provided in a part of the region including the. The amount of relative rotation between the rotation shaft and the rotation transmission member is limited by the vane coming into contact with the protrusion. For this reason, in the most advanced angle state or the most retarded angle state where the vane is in contact with the protruding portion, although the pressure receiving area of the vane is limited, the vane pressure receiving surface is positioned radially outside and rotates with the center of the pressure receiving surface. The distance between the shaft centers is longer than in the prior art. Thereby, the torque for rotating the rotating shaft relative to the rotation transmission member in the most advanced angle state or the most retarded angle state is increased, and the operation responsiveness of the valve opening / closing timing control device is improved.

The vane may have a plate shape. In this way, the vane can be reduced in weight, and the responsiveness of position control is improved .
Also, the protrusions may there be continuously formed in the inner peripheral surface of the projection. If it does in this way, a projection part can be formed easily.

Hereinafter, an embodiment of a valve timing control apparatus according to the present invention will be described with reference to the drawings.
The first embodiment of the valve opening / closing timing control device shown in FIGS. 1 to 4 includes a camshaft 10 that is rotatably supported by a cylinder head 110 of the internal combustion engine and an internal assembly that is integrally assembled to the tip of the camshaft 10. A rotary shaft for opening and closing a valve composed of the rotor 20, an external rotor 30, a front plate 40, a cap 41, a rear plate 50, a timing pulley 60, and the like externally mounted on the camshaft 10 and the internal rotor 20 so as to be relatively rotatable within a predetermined range. , A six-vane 70 assembled to the inner rotor 20, a lock mechanism 80 assembled to the outer rotor 30, and the like. As is well known, the timing pulley 60 is configured to transmit rotational power in the clockwise direction of FIG. 2 from a crank pulley via a resin or rubber timing belt (both not shown).

  The camshaft 10 has a known cam for opening and closing the intake valve, and an advance angle passage 12 and a retard angle passage 11 extending in the axial direction of the camshaft 10 are provided therein. The advance passage 12 is connected to the connection port 102 of the switching valve 100 through an annular passage 15 provided in the camshaft 10 and a connection passage P2. The retard passage 11 is connected to the connection port 101 of the switching valve 100 through the radial passage 13 and the annular passage 14 provided in the camshaft 10 and the connection passage P1.

  The switching valve 100 is capable of moving the spool 104 to the right in FIG. 1 against the spring 105 by energizing the solenoid 103. When not energized, the switching valve 100 is connected to an oil pump (not shown) driven by the internal combustion engine. The connected supply port 106 communicates with the connection port 101, the connection port 102 communicates with the discharge port 107, and when energized, the supply port 106 communicates with the connection port 102, and the connection port 101 communicates with the discharge port 108. It is comprised so that it may communicate with. For this reason, when the solenoid 103 is not energized, the retarding passage 11 is supplied with the lubricating oil of the internal combustion engine as the operating oil, and when energized, the operating oil is supplied to the advance passage 12.

  The inner rotor 20 is integrally fixed to the camshaft 10 by hollow bolts 16 and has vane grooves 21 for movably mounting six vanes 70 in the radial direction. A passage for supplying and discharging hydraulic oil from the advance passage 12 to the partitioned advance chamber R1 (an annular groove communicating with the advance passage 12 and six communication holes (grooves) extending radially outward from the annular groove. 23) and a passage (groove) 22 for supplying and discharging hydraulic oil from the retard passage 11 to the retard oil chamber R2 defined by each vane 70. These passages 22 and 23 are opened on one side surface and the other side surface of the internal rotor 20, respectively, and the openings are closed by a front plate 40 and a rear plate 50 described later. Each vane 70 is urged radially outward by a vane spring 71 (see FIG. 1) accommodated in the bottom of the vane groove 21. In FIG. 2, reference numeral 80 denotes a lock mechanism that mechanically holds the phases of the internal rotor 20 and the external rotor 30 in the most retarded angle state. In this embodiment, the phase hold is released by the advance hydraulic pressure. Has been.

  The outer rotor 30 is assembled to the outer periphery of the inner rotor 20 so as to be relatively rotatable within a predetermined range. A front plate 40 and a rear plate 50 are joined to both sides of the outer rotor 30 via seal members S1 and S2, and a timing pulley 60 is provided. In addition, they are integrally connected by six bolts B1. A cap 41 is assembled in a fluid-tight manner on the front plate 40, thereby forming a passage 42 that connects the retard passage 11 of the camshaft 10 and the passage 22 of the internal rotor. The outer rotor 30 accommodates each vane 70, and the inner rotor 20 includes six fluid pressure chambers R0 each divided into an advance chamber R1 and a retard chamber R2 by each vane 70. Six recesses 32 formed by the front plate 40 and the rear plate 50 are formed, projecting inward in the radial direction between the adjacent recesses 32, and the inner circumferential surface of the inner rotor 20. Six protrusions 31 are formed which slidably contact the outer peripheral surface and partition the recess 32 in the circumferential direction at the end surface in the circumferential direction (rotation direction).

  In the present embodiment, as shown in FIG. 2, the protrusion 31 protrudes in the circumferential direction on the radially inner side of the circumferential end face in the advance angle direction and the retard angle direction, and the inner peripheral surface thereof is the inner side of each protrusion. Stopper portions 31a and 31b that are continuous with the peripheral surface are formed, respectively, and adjusted by the valve opening / closing timing control device when the radially inner base portions of the vanes 70 abut against the stopper portions 31a and 31b. The phase (relative rotation amount) is limited, and in the state where the phase is limited, the advance angle chamber R1 and the retard angle chamber R2 are radially outer portions of the circumferential end surfaces of the respective protrusions 31. And each vane 70 is formed. As shown in FIGS. 2 to 4, grooves 31a1 and 31b1 extending in the radial direction are formed on the surfaces of the stopper portions 31a and 31b facing the front plate 40 and the rear plate 50, respectively. Thereby, in the most advanced angle state shown in FIG. 2 in which each vane 70 is in contact with each stopper portion 31a and the phase is limited, the passage 22 is inserted into the retard chamber R2 via the groove 31a1 (front plate 40 side). In the most retarded state in which the vanes 70 are in contact with the stopper portions 31b and the phase is limited, the passage 23 is communicated with the advance chamber R1 through the groove 31b1 (on the rear plate 50 side). . The groove 31a1 on the rear plate 50 side and the groove 31b1 on the front plate 40 side are formed at the same time as the molding of the internal rotor 20 so that the mounting direction of the internal rotor 20 is not restricted by the grooves 31a1 and 31b1.

  Further, as shown in FIG. 2, in the present embodiment, protrusions 33 that protrude radially outward at equal intervals are formed on the outer peripheral surface of the outer rotor 30, and each protrusion 33 and each protrusion The bolts B1 are respectively fitted in the respective through holes formed coaxially with the protrusions provided on the front plate 40 and the rear plate 50 corresponding to the portion 33, and are screwed into the timing pulley 60. The front plate 40, the external rotor 30, and the rear plate 50 are sandwiched between the head and the timing pulley 60. Thereby, the cavity S is formed between the inner periphery of the timing pulley 60 and the outer periphery of the external rotor 30 in the radial direction between the adjacent protrusions 33.

  In the valve timing control apparatus of the present embodiment configured as described above, the switching valve 100 appropriately controls the supply and discharge of hydraulic oil to and from the advance oil chamber R1 and the retard oil chamber R2. 2, that is, from the most advanced angle state where each vane 70 abuts against each stopper portion 31 a to the most retarded angle state where each vane 70 abuts against each stopper portion 31 b, the inner rotor 20 and the outer rotor 30 The relative rotation amount (phase) is controlled. By the way, in the present embodiment, the inner rotor 20 and the outer rotor 30 are caused by the vanes 70 coming into contact with the stopper portions 31a and 31b formed to protrude in the rotational direction on the radially inner side portions of the circumferential end surfaces of the protrusions 31. As described above, in the most advanced angle state and the most retarded state where the vanes 70 are in contact with the stopper portions 31a and 31b, as described above, the retard angle chamber R2 and the advance angle chamber R1 are limited. Although the pressure receiving area of each vane 70 is limited and the pressure receiving surface of each vane 70 is limited, the pressure receiving surface of each vane 70 is positioned radially outside, and the center of the pressure receiving surface and the axis of the inner rotor 20. The distance between them becomes longer than that of a conventional valve opening / closing timing control device in which a stopper portion is provided on the radially outer portion of the circumferential end face of each protrusion. Thereby, the torque for rotating the internal rotor 20 relative to the external rotor 30 in the most advanced angle state and the most retarded angle state is increased, and the operation responsiveness of the valve opening / closing timing control device is improved.

  By the way, the camshaft 10 is always subjected to fluctuating torque during normal operation of the internal combustion engine, and the fluctuating torque tries to vibrate the vane 70 in the circumferential direction in each fluid pressure chamber R0 via the internal rotor 20. To do. Therefore, in the present embodiment, in the most advanced angle state and the most retarded angle state, the retard angle chamber R2 and the advance angle chamber R1 communicate with the passages 22, 23 via the grooves 31a1, 31b1, respectively. The retarding chamber R2 and the advance chamber R1 act as a damper chamber against the vibration of the vane 70 having a high height, and the vibration of the vane is suppressed by the damping action, and in the most advanced state and the most retarded state. The phase is maintained stably. In addition, this damping action does not form the grooves 31a1 and 31b1 in the stopper portions 31a and 31b formed on the circumferential end surfaces facing each other of the pair of protrusions 31 that divide one fluid pressure chamber R0 in the circumferential direction, for example. It can be obtained even better by configuring or by reducing the flow path diameter of the pair of grooves 31a1 and 31b1.

  In the above-described most advanced angle state or most retarded angle state, each vane 70 receives the fluctuation torque of the camshaft 10 and the drive torque of the valve opening / closing timing control device. In this embodiment, the stopper portion 31a and 31b are formed on the radially inner portion of the protrusion 31, and these torques act on the torque receiving portion extending radially outward from the base of the vane 70 attached to the vane groove 21 of the internal rotor 20. Therefore, a shear load as shown in FIG. 4 acts on the base of the vane 70. For this reason, each vane comes into contact with a stopper portion formed on the radially outer portion of the circumferential end surface of each protrusion, and the moment load acts on the base of each vane by the above-described variable torque and driving torque. Compared with the conventional valve opening / closing timing control device, the strength of the vane can be remarkably improved, and the reliability of the valve opening / closing timing control device can be improved.

  FIG. 5 shows a second embodiment of the valve timing control apparatus according to the present invention. In the second embodiment, as shown in FIG. 5, a pair of protrusions 31 that divide one fluid pressure chamber R01 out of six fluid pressure chambers R0 and R01 in the circumferential direction face each other in the circumferential direction. Stopper portions 31a and 31b projecting in the circumferential direction are formed only on the end surface in the radial direction. In the stopper portions 31a and 31b, the retard chamber R2 and the advance chamber R1 defined in the fluid pressure chamber R01 are connected to the stopper portions 31a and 31b of the vane 70 as in the first embodiment. Grooves 31a1 and 31b1 are formed to communicate with the passages 22 and 23, respectively (see FIG. 3). Thereby, the base (diameter of relative rotation) adjusted by the valve opening / closing timing control device is brought into contact with the stopper portions 31a and 31b by the radially inner base portion of the vane 70 accommodated in the fluid pressure chamber R01. In this state where the phase is limited, a gap 71 is formed between the vane 70 accommodated in the other fluid pressure chamber R0 and the circumferential end surface of the protrusion 31. It has become. In the second embodiment, the other configurations are the same as those of the first embodiment described above, and thus the description thereof is omitted.

  In the valve opening / closing timing control apparatus of the second embodiment configured as described above, the switching valve 100 appropriately controls the supply and discharge of hydraulic oil to and from the advance oil chamber R1 and the retard oil chamber R2. 5, the most advanced angle state (the vane 70 accommodated in the fluid pressure chamber R01 abuts against the stopper portion 31a, and the vanes 70 and the projections 31 accommodated in the fluid pressure chamber R0). From a state in which a gap 71 is formed between the retarding chamber R2 and the circumferential end surface of the retarding chamber R2) to the most retarded state (the vane 70 accommodated in the fluid pressure chamber R01 abuts against the stopper portion 31b). Relative rotation of the inner rotor 20 and the outer rotor 30 until a gap 71 is formed between each vane 70 accommodated in the chamber R0 and the circumferential end surface of each projection 31 on the side of the advance angle chamber R1. The quantity (phase) is controlled. As described above, in the second embodiment, the vane 70 in which the phase adjusted by the valve opening / closing timing control device (the relative rotation amount between the rotation shaft and the rotation transmission member) is accommodated in one fluid pressure chamber R01 is the stopper. Since it restrict | limits by contact | abutting to part 31a, 31b, it is not necessary to make all the relative positions of each vane in each fluid pressure chamber equal, and the manufacturing cost of the said valve opening / closing timing control apparatus is reduced significantly. Further, in the state where the phase is limited, that is, in the most advanced angle state or the most retarded angle state, the retardation chamber R2 and the advance chamber R1 of the fluid pressure chamber R0 are limited in the circumferential direction and the radial direction. Although the pressure receiving area of each vane 70 is limited, the pressure receiving surface of each vane 70 is positioned radially outward to increase the distance between the center of the pressure receiving surface and the axis of the inner rotor 20 and other fluid pressures. In the retarding chamber R2 and the advance chamber R1 of the chamber R0, a gap 71 is maintained between the vane 70 and the protrusion 31, and a large pressure receiving area of the vane 70 is ensured, so that phase control response is improved. Is done.

  In the second embodiment, similarly to the first embodiment described above, the retard chamber R2 and the advance chamber R1 of the fluid pressure chamber R0 are respectively grooves in the most advanced angle state and the most retarded angle state. Since they communicate with the passages 22 and 23 via 31a1 and 31b1, the retarding chamber R2 and the advance chamber R1 act as damper chambers against the vibration of the vane 70 having a high frequency, and the vane is caused by the damping action. Is suppressed, and the phase in the most advanced angle state and the most retarded angle state is stably maintained. Further, in the second embodiment, in the most advanced angle state or the most retarded angle state, the fluctuation torque of the camshaft 10 and the driving of the valve opening / closing timing control device are driven by one vane 70 accommodated in the fluid pressure chamber R0. As in the first embodiment described above, since the shear load acts on the vane 70 accommodated in the fluid pressure chamber R0 due to these torques, the diameter of the circumferential end face of each projection is received. In the conventional valve opening / closing timing control device of the above-mentioned publication in which each vane abuts on the outer side in the direction and a moment load acts on the base of each vane due to the above-described fluctuation torque and driving torque, the phase is adjusted by one vane. Compared with the case of limiting, the strength of the vane can be remarkably improved, and the manufacturing cost can be reduced without impairing the reliability of the valve timing control device.

  In the above embodiment, the present invention is applied to the valve opening / closing timing control device assembled to the intake camshaft 10, but the present invention is also applied to the valve opening / closing timing control device assembled to the exhaust camshaft. It can be implemented. In the above embodiment, the present invention is applied to the valve timing control apparatus including six vanes, fluid pressure chambers, protrusions, and the like, but the number of these can be changed as appropriate. In the above embodiment, the rotational power from the crankshaft is transmitted to the camshaft via the timing belt. However, in the present invention, the rotational power from the crankshaft is transmitted to the camshaft via the timing chain or gear. The same can be applied to what is communicated.

[The invention's effect]
As described above, according to the present invention, a plurality of fluid pressure chambers are respectively arranged in the rotational direction on the radially inner side portions of at least a pair of the projecting portions of the adjacent projecting portions that divide the fluid pressure chambers in the rotational direction. When the vane abuts on the projecting portion formed to project, the relative rotation amount of the rotation shaft and the rotation transmitting member is limited, and in the most advanced state or the most retarded state where the vane contacts the projecting portion, the pressure of the vane is received. Although the area is limited, the vane pressure-receiving surface is positioned on the radially outer side, and the distance between the center of the pressure-receiving surface and the axis of the rotation shaft can be made longer than before, so that the most advanced angle state and The torque for rotating the rotating shaft relative to the rotation transmitting member in the most retarded state can be increased, and the operation responsiveness of the valve opening / closing timing control device can be improved.

The longitudinal cross-sectional view which shows the valve timing control apparatus of this invention Sectional drawing along the AA line of FIG. FIG. 6 is a cross-sectional view taken along line BB in FIG. 2 and line CC in FIG. 5. FIG. 3 is a partially enlarged view of the vicinity of a vane 70 in FIG. 2. It is sectional drawing along the AA line of FIG. 1 which shows 2nd Embodiment of the valve timing control apparatus according to this invention. It is a longitudinal cross-sectional view of the conventional valve timing control apparatus. It is sectional drawing along the DD line of FIG.

Explanation of symbols

10 Camshaft (Rotating shaft)
11 Delay passage (second passage)
12 Advance passage (first passage)
20 Internal rotor (rotating shaft)
22 passage (second passage)
23 passage (first passage)
30 External rotor (rotation transmission member)
31 Projection 31a, 31b Stopper (projection)
31a1, 31b1 groove (communication path)
40 Front plate (Rotation transmission member)
50 Rear plate (Rotation transmission member)
60 Timing pulley (rotation transmission member)
70 Vane 100 Switching valve 110 Cylinder heads R0, R01 Fluid pressure chamber R1 Advance oil chamber R2 Delay oil chamber

Claims (3)

A rotary shaft for opening and closing a valve that is rotatably assembled to a cylinder head of an internal combustion engine;
A rotation transmission member that is externally mounted on the rotation shaft so as to be relatively rotatable within a predetermined range, receives rotational power from the crankshaft, and has a plurality of protrusions projecting toward the rotation shaft along the rotation direction;
A plurality of fluid pressure chambers formed by partitioning the rotation shaft and the rotation transmission member in the rotation direction by the plurality of protrusions;
For each of the plurality of fluid pressure chambers, a vane attached to the rotating shaft so as to be divided into an advance angle chamber and a retard angle chamber;
A passage that is formed on the rotating shaft and that supplies and discharges working fluid to and from the advance chamber and the retard chamber ,
A valve opening / closing timing control device for controlling the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine,
Providing a protrusion with which the vane can abut in a part of the end surface of the protrusion facing the vane , including a radially inner end ,
A valve opening / closing timing control device in which a passage that connects the passage and a fluid pressure chamber located radially outside the protrusion is formed in the protrusion when the vane and the protrusion are in contact with each other . The valve opening / closing timing control device according to claim 1, wherein the vane has a plate shape. The protrusion, the valve timing control apparatus according to claim 1 or 2 is formed continuously with the inner peripheral surface of the projection.

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