JP4560736B2 - Valve timing adjustment device - Google Patents

Description

  The present invention relates to a valve timing adjusting device for an internal combustion engine that adjusts the opening / closing timing of at least one of an intake valve and an exhaust valve (hereinafter, the opening / closing timing is referred to as a valve timing).

  2. Description of the Related Art Conventionally, a valve timing adjusting device that adjusts the valve timing of an intake valve or an exhaust valve by forming a phase difference between a vane rotor and a housing by hydraulic oil pressure is known (see Patent Document 1). This valve timing adjusting device has an advance hydraulic chamber and a retard hydraulic chamber between a relative rotating vane rotor and a housing. Then, the hydraulic pressure in the advance hydraulic chamber and the retard hydraulic chamber is controlled by switching between the state in which the hydraulic oil from the oil pump is supplied to the advance hydraulic chamber and the state in which the hydraulic oil is supplied to the retard hydraulic chamber. By controlling the hydraulic pressure, the vane rotor and the housing are relatively rotated, and a phase difference is formed between them to adjust the valve timing.

  The hydraulic path from the oil pump to the advance hydraulic chamber and the retard hydraulic chamber includes a shaft side passage formed in the camshaft and a bearing side passage formed in the cylinder head as a bearing member that supports the camshaft in the radial direction. It consists of. The hydraulic oil discharged from the oil pump is supplied to the advance hydraulic chamber and the retard hydraulic chamber through the bearing side passage and the shaft side passage in order.

JP 2003-247404 A

  Here, in the valve timing adjusting device disclosed in Patent Document 1, the camshaft that is rotated by the driving force transmitted from the driving shaft of the internal combustion engine receives a reaction force from the intake valve or the exhaust valve. The value of this reaction force changes alternately between positive and negative as described below. That is, the direction of the reaction force changes alternately.

The state in which the reaction force is a positive value is a state in which the cam pushes down the intake valve or the exhaust valve against the elastic force of the valve spring, and the direction of the reaction force is a hindrance to the driving force. It has become the direction.
On the other hand, the state in which the reaction force is negative is a state in which the cam releases the elastic force of the valve spring to raise the intake valve or the exhaust valve, and the direction of the reaction force is the same direction as the driving force. It is the direction to urge the camshaft.
Therefore, the camshaft receives a reaction force that changes alternately between positive and negative in conjunction with the rotational position of the cam from the intake valve or the exhaust valve.

  As a result, the vane rotor fixed to the camshaft alternately repeats forward and reverse rotation relative to the housing. Then, the pressure of the hydraulic oil in the advance hydraulic chamber and the retard hydraulic chamber pulsates, and a negative pressure is generated in the shaft side passage along with the pulsation.

  When the negative pressure is generated, air is sucked into the shaft-side passage from between the cylinder head and the camshaft, and air may be mixed into the hydraulic oil. If air is mixed into the hydraulic oil, it becomes difficult to maintain the phase difference formed between the vane rotor and the housing at the target phase difference. As a result, the valve timing of the intake valve or the exhaust valve is set to the target timing. It will be difficult to control.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a valve timing adjusting device that improves the controllability of the valve timing of an intake valve or an exhaust valve by suppressing air mixing into hydraulic oil.

In the first aspect of the invention, the bearing member is provided with a supply passage different from the bearing-side advance passage and the bearing-side retard passage. Since oil is supplied to the camshaft from the supply port of the supply passage, an oil film is formed on the portion of the camshaft facing the supply port. This oil film spreads along the outer periphery of the camshaft due to the rotation of the camshaft. Therefore, at least one of the opposite side of the shaft side retarded communication port and the opposite side of the shaft side advanced communication port with respect to the shaft side retarded communication port with respect to the shaft side advanced angle communication port, An oil film is formed that extends along the outer periphery of the film.
Since this oil film exhibits a sealing function against air, even if negative pressure is generated in the shaft side advance passage or the shaft side retard passage, the shaft side advance communication port or the shaft side is provided between the bearing member and the camshaft. It is possible to suppress air from being sucked into the retarded communication port. Therefore, air mixing into the hydraulic oil can be suppressed, and controllability of the valve timing of the intake valve or the exhaust valve can be improved.

  According to a second aspect of the present invention, the bearing member is provided with a bearing-side supply groove that is formed in the bearing member, extends annularly along the circumferential direction of the camshaft, and communicates with the supply port. Therefore, oil is supplied to the camshaft from the entire circumference. Therefore, since it is possible to reliably realize the oil film having an annular shape extending along the outer periphery of the camshaft, it is possible to improve the sealing performance of the oil film that exhibits the sealing function.

  According to a third aspect of the present invention, there is provided a shaft side supply groove formed on the camshaft, extending annularly along the circumferential direction of the camshaft and communicating with the supply port. Therefore, the oil supplied from the supply port accumulates in the shaft-side supply groove, and the oil film described above is formed by the accumulated oil. Therefore, since it is possible to reliably realize the oil film having an annular shape extending along the outer periphery of the camshaft, it is possible to improve the sealing performance of the oil film that exhibits the sealing function.

  In the invention according to claim 4, the supply port is located on the opposite side of the direction of the force that the camshaft receives in the radial direction from the driving force transmission system with respect to the rotation center of the camshaft. Here, with respect to the radial clearance formed between the camshaft and the bearing member, the clearance increases at a portion opposite to the direction of the force that the camshaft receives in the radial direction with respect to the rotation center of the camshaft. Therefore, according to the invention of claim 4, in which the supply port is positioned in such a portion having a large clearance, oil easily enters between the camshaft and the bearing member, and the oil film extends along the outer periphery of the camshaft. Becomes easier to spread. Therefore, the sealing performance of the oil film that exhibits the sealing function can be improved.

  According to the fifth aspect of the present invention, the supply port is located on the opposite side of the direction of the force that the camshaft receives in the thrust direction from the driving force transmission system with respect to the shaft side advance communication port and the shaft side retard communication port. Here, regarding the clearance in the thrust direction formed between the camshaft and the abutting portion, the clearance becomes large at a portion opposite to the direction of the force that the camshaft receives in the thrust direction. Therefore, according to the invention of claim 5, in which the supply port is positioned in such a portion having a large clearance, oil easily enters between the camshaft and the bearing member, and an oil film is formed along the outer periphery of the camshaft. Becomes easier to spread. Therefore, the sealing performance of the oil film that exhibits the sealing function can be improved.

In a sixth aspect of the present invention, the valve timing adjusting device according to any one of the first to fifth aspects is applied to a so-called roller rocker type driving force transmission system in which a cam rolls and contacts a roller of a rocker arm. . In the case of the roller rocker type, the power transmission loss between the intake valve or the exhaust valve and the camshaft is reduced due to the rolling contact structure. However, as a contradiction, for example, as shown by the solid line in FIG. 5, both the positive reaction force and the negative reaction force received by the camshaft from the intake valve or the exhaust valve become large. Therefore, the negative pressure generated in the shaft-side advance passage or the shaft-side retard passage becomes larger than in the case of a so-called direct drive type driving force transmission system in which the cam directly contacts the intake valve or the exhaust valve.
Therefore, according to the invention of claim 6, the valve timing adjusting device according to any one of claims 1 to 5 is applied to the roller rocker type driving force transmission system in which such a large negative pressure is generated. The effect of suppressing air mixing into the oil can be suitably exhibited.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
An example in which the valve timing adjusting device 1 according to the first embodiment of the present invention is applied to an exhaust valve of an internal combustion engine of a vehicle is shown in FIGS.
The valve timing adjusting device 1 is installed in a driving force transmission system that transmits a driving force of a crankshaft (not shown) that is a driving shaft of an internal combustion engine to an exhaust valve 97 (see FIG. 4), and is a driven shaft of the internal combustion engine. An apparatus main body 10 including the camshaft 2 and an apparatus control system 30 that controls hydraulic oil supply to the apparatus main body 10 are provided.

First, the driving force transmission system will be described with reference to FIG.
The driving force transmission system is a so-called roller rocker type including a rocker arm 91 that transmits a driving force from the camshaft 2 to the exhaust valve 97, and a roller 92 that is in rolling contact with the cam 201 that rotates integrally with the camshaft 2. It is. The roller 92 includes an outer ring 93 that is in rolling contact with the cam 201, an inner ring 94 that is supported by the rocker arm 91, and a rolling element 95 that supports the outer ring 93 so as to be rotatable with respect to the inner ring 94. One end of the rocker arm 91 contacts the upper end of the exhaust valve 97, and the other end is formed with a pivot hole 96 in which a pivot (not shown) is disposed.

  When the cam 201 rotates together with the camshaft 2 in the clockwise direction from the state of FIG. 4, the rocker arm 91 is pushed downward together with the roller 92. Then, the rocker arm 91 pushes down the exhaust valve 97 against the elastic force of the valve spring 98. At this time, the camshaft 2 receives a reaction force in a direction that hinders the driving force (counterclockwise in FIG. 4). That is, the reaction force at this time is a positive value.

  Thereafter, when the cam 201 further rotates clockwise, the exhaust valve 97 is raised by the elastic force of the valve spring 98, the rocker arm 91 is pushed upward, and the cam 201 is directed in the same direction as the driving force via the roller 92 (FIG. 4). (Clockwise). That is, the reaction force at this time is a negative value. FIG. 5 is a graph showing a change in torque due to the reaction force received by the camshaft 2, and the torque changes following the rotation angle of the cam 201.

Next, the apparatus main body 10 will be described with reference to FIGS. 1 and 2.
In the apparatus main body 10, the housing 18 includes a sprocket 11, a cylindrical shoe housing 12, and a disc-shaped front plate 13.
The shoe housing 12 includes shoes 121, 122, 123, and 124 as partitioning portions that protrude radially inward from positions that are substantially equidistant in the rotational direction on the inner peripheral wall thereof. The protruding end surfaces of the shoes 121 to 124 have an arc shape when viewed from the direction perpendicular to the plane of FIG. 2 and are in sliding contact with the outer peripheral wall surface of the boss portion 141 of the vane rotor 14. A seal member 15 is fitted in the recesses of the shoes 121 to 124. A storage chamber 50 is formed between the shoes 121 to 124 adjacent in the rotation direction. Each storage chamber 50 is surrounded by the corresponding shoe side surface and the inner peripheral wall surface of the shoe housing 12, and has a fan shape when viewed from the direction perpendicular to the plane of FIG.

  The sprocket 11, the shoe housing 12, and the front plate 13 are bolted coaxially so that the shoe housing 12 is sandwiched between the front plate 13 and the sprocket 11. The sprocket 11 is connected to a crankshaft (not shown) by a chain (not shown). As a result, the housing 18 rotates in conjunction with the crankshaft when the driving force is transmitted from the crankshaft to the sprocket 11. The housing 18 rotates clockwise in FIG.

The vane rotor 14 is accommodated in a housing 18, and both end surfaces in the axial direction of the vane rotor 14 are in sliding contact with the wall surface 111 of the sprocket 11 and the wall surface 131 of the front plate 13. The vane rotor 14 includes a boss portion 141 and vanes 142, 143, 144, and 145.
The bush 20 fitted to the boss portion 141 is inserted on the inner peripheral side of the front plate 13 so as to be rotatable relative to the front plate 13 and coaxially with the rotation center O. The boss 141 is bolted to the camshaft 2 together with the bush 20. Accordingly, the vane rotor 14 and the camshaft 2 rotate in the clockwise direction in FIG. Further, the vane rotor 14 can rotate relative to the housing 18 together with the camshaft 2. 2 represents the relative rotation direction of the vane rotor 14 relative to the housing 18 toward the advance side (hereinafter referred to as the advance direction). An arrow Y shown in FIG. 2 represents a relative rotation direction of the vane rotor 14 relative to the housing 18 toward the retard side (hereinafter referred to as a retard direction). 2 shows a state in which the vane rotor 14 is localized at the most advanced angle position where relative rotation in the advance angle direction X is restricted with respect to the housing 18 and relative rotation in the retard angle direction Y is allowed. A torsion coil spring 22 is interposed between the front plate 13 and the bush 20. One end of the torsion coil spring 22 is locked to the shoe housing 12 and the front plate 13, and the other end is locked to the vane rotor 14. The restoring force of the torsion coil spring 22 acts as a torque for rotating the vane rotor 14 relative to the housing 18 in the advance angle direction X.

  The vanes 142 to 145 protrude radially outward from the positions of the outer peripheral walls of the boss portion 141 that are substantially equidistant in the rotational direction, and are accommodated in the respective accommodation chambers 50. The protruding end surfaces of the vanes 142 to 145 are formed in an arc shape when viewed from the direction perpendicular to the plane of FIG. 2 and are in sliding contact with the inner peripheral wall surface of the shoe housing 12. A seal member 16 is fitted in a recess provided on the protruding end face of each of the vanes 142 to 145. The vanes 142 to 145 partition the corresponding storage chambers 50 to form an advance hydraulic chamber and a retard hydraulic chamber on both sides in the rotational direction.

  Specifically, the advance hydraulic chamber 51 between the shoe 121 and the vane 142, the advance hydraulic chamber 52 between the shoe 122 and the vane 143, and the advance hydraulic chamber 53 and the shoe 124 between the shoe 123 and the vane 144, An advance hydraulic chamber 54 is formed between the vanes 145. Further, the retarding hydraulic chamber 55 between the shoe 124 and the vane 142, the retarding hydraulic chamber 56 between the shoe 121 and the vane 143, and the retarding hydraulic chamber 57 between the shoe 122 and the vane 144, the shoe 123 and the vane 145, respectively. A retard hydraulic chamber 58 is formed between them. When the vane rotor 14 is in the most advanced position in FIG. 2 with respect to the housing 18, the volumes of the advance hydraulic chambers 51 to 54 are maximized, and the volumes of the retard hydraulic chambers 55 to 58 are minimized. On the other hand, when the vane rotor 14 is in the most retarded position with respect to the housing 18, the volumes of the retard hydraulic chambers 55 to 58 are maximized, and the volumes of the advance hydraulic chambers 51 to 54 are minimized.

  The advance hydraulic chambers 51 to 54 communicate with advance passages 61 to 64 formed in the sprocket 11, respectively. All the advance passages 61 to 64 communicate with a shaft side advance passage 71 formed in the camshaft 2. On the other hand, each of the retarded hydraulic chambers 55 to 58 communicates with retarded passages 65 to 68 formed in the vane rotor 14. All of the retard passages 65 to 68 communicate with a shaft-side retard passage 72 formed in the camshaft 2.

  The camshaft 2 is supported in the radial direction by the bearing member 80. The bearing member 80 includes a cam cap 81 positioned on the upper side of the camshaft 2 and a cylinder head 82 positioned on the lower side. The cam cap 81 and the cylinder head 82 are made of metal, and are coupled by fastening means such as a bolt (not shown). The camshaft 2 is formed with annular flange portions 83 and 84 extending in the radial direction along the outer peripheral surface of the camshaft. The flange portions 83 and 84 as these abutting portions abut against the bearing member 80 in the thrust direction, so that the movement of the camshaft 2 in the thrust direction is restricted.

  The cylinder head 82 is formed with a bearing-side advance passage 85 communicating with the shaft-side advance passage 71 and a bearing-side advance passage 86 communicating with the shaft-side retard passage 72. The shaft side advance passage 71 has a shaft side advance passage 711 communicating with the bearing side advance passage 85, and the shaft side retard passage 72 is a shaft side retard passage communicating with the bearing side retard passage 86. A corner communication port 721 is provided. The shaft side advance communication port 711 and the shaft side retard communication port 721 have a groove shape extending annularly around the axis of the camshaft 2. Therefore, in a state where the camshaft 2 is rotating, the shaft side advance passage 71 and the bearing side advance passage 85 are always in communication with each other via the shaft side advance communication port 711, and the shaft side retard passage 72 and the bearing are in communication. The side retardation passage 86 always communicates with the shaft side retardation communication port 721.

  Further, in the cylinder head 82, a supply passage 87 having a supply port 871 for supplying oil to the camshaft 2 is formed separately from the bearing-side advance passage 85 and the bearing-side retard passage 86. The supply port 871 does not have a shape extending annularly along the outer peripheral surface of the camshaft 2 but has a shape that opens only facing a part of the outer peripheral surface. The bearing side advance passage 85, the bearing side retard passage 86 and the supply passage 87 are arranged in a line in the thrust direction of the camshaft 2. The supply passage 87 and the supply port 871 are disposed only on the opposite side of the bearing-side advance passage 85 with respect to the bearing-side retard passage 86.

  A stopper piston 26 is accommodated in the vane 142. The stopper piston 26 is engaged with the fitting ring 27 of the sprocket 11 by the restoring force of the compression coil spring 28, thereby restraining the vane rotor 14 at the most advanced position with respect to the housing 18. On the other hand, the stopper piston 26 is separated from the fitting ring 27 by at least one of the force by the hydraulic pressure supplied from the retard hydraulic chamber 55 through the passage 291 and the force by the hydraulic pressure supplied from the advance hydraulic chamber 51 through the passage 292. The vane rotor 14 is allowed to rotate relative to the disengagement position.

Next, the device control system 30 will be described with reference to FIG.
The switching valve 31 as valve means is connected to a bearing side advance passage 85, a bearing side retard passage 86, a supply passage 87, a pump passage 75, and drain passages 76 and 77. Here, an oil pump 4 as a hydraulic pressure supply source is installed in the pump passage 75, and the oil pump 4 pumps hydraulic oil from the oil tank 5 through the upstream side of the pump passage 75 and operates through the downstream side of the pump passage 75. Oil is discharged to the switching valve 31 and the supply passage 87. The oil pump 4 of the first embodiment is a so-called mechanical pump that operates by transmitting the driving force of the crankshaft. The drain passages 76 and 77 are provided so that hydraulic fluid can be discharged from the switching valve 31 to the oil tank 5 side.

  The electromagnetic drive unit 32 of the switching valve 31 includes a yoke 37, a fixed core 33, a movable core 34, a shaft 35, and a coil 36. The yoke 37, the fixed core 33, and the movable core 34 are made of a magnetic material and constitute a magnetic circuit. The shaft 35 is press-fitted into the movable core 34 and can be reciprocated in the left-right direction in FIG. The coil 36 generates a magnetic flux that passes through the magnetic circuit when energized. The coil 36 is electrically connected to an electronic control unit (ECU) 6. When the energization is controlled by the ECU 6, the magnetic attractive force generated between the cores 33 and 34 is changed to drive the shaft 35.

  The valve portion 40 of the switching valve 31 has a sleeve 41 and a spool 42. A plurality of openings 411, 412, 413, 414, and 415 through which hydraulic oil passes are formed at predetermined positions of the sleeve 41. The opening 411 communicates with the bearing-side advance passage 85 and the opening 412 communicates with the bearing-side advance passage 86. The opening 414 communicates with the pump passage 75, and the openings 413 and 415 communicate with the drain passages 76 and 77, respectively. The spool 42 is supported by the inner wall of the sleeve 41 so as to be capable of reciprocating in the axial direction. In the spool 42, lands 421 and 422 having an outer diameter substantially equal to the inner diameter of the sleeve 41 are in sliding contact with the inner wall of the sleeve 41. The end surface of the spool 42 on the movable core 34 side is in contact with the end surface of the shaft 35, and the end surface of the spool 42 opposite to the movable core 34 moves the spool 42 to the shaft 35 side (right direction in FIG. 1) by restoring force. It is in contact with the spring 43 to be pressed. Therefore, when the electromagnetic drive unit 32 reciprocates the shaft 35, the spool 42 reciprocates within the sleeve 41. That is, the spool 42 is a valve member that is electromagnetically driven in accordance with energization of the coil 36 of the electromagnetic drive unit 32.

  FIG. 3A shows a state in which the energization of the coil 36 is controlled to be off by the ECU 6. In this state, the spool 42 is pressed by the restoring force of the spring 43 to the right in FIG. As a result, the hydraulic oil discharged from the oil pump 4 to the pump passage 75 flows into the sleeve 41 from the opening 414 and flows from the opening 411 to the bearing side advance passage 85. That is, the bearing side advance passage 85 is opened and communicated with the oil pump 4, and the oil discharged from the oil pump 4 is supplied to the bearing side advance passage 85. On the other hand, the hydraulic oil in the bearing-side retarding passage 86 flows into the sleeve 41 from the opening 412 and is discharged from the opening 413 to the oil tank 5 through the drain passage 413.

  FIG. 3B shows a state in which energization of the coil 36 is turned on by the ECU 6 and controlled to a predetermined duty ratio. In this state, the spool 42 is pressed to the left in FIG. 3B against the restoring force of the spring 43, and the restoring force of the spring 43 and the magnetic attractive force between the cores 33 and 34 of the electromagnetic drive unit 32 are balanced. Localize to position. As a result, the hydraulic oil discharged from the oil pump 4 to the pump passage 75 flows into the sleeve 41 from the opening 414 and flows from the opening 412 to the bearing-side retardation passage 86. That is, the bearing-side retardation passage 86 is opened and communicates with the oil pump 4, and the oil discharged from the oil pump 4 is supplied to the bearing-side retardation passage 86. On the other hand, the hydraulic oil in the bearing side advance passage 85 flows into the sleeve 41 from the opening 411 and is discharged from the opening 415 to the oil tank 5 through the drain passage 77.

  FIG. 3 (c) shows a state in which energization of the coil 36 is turned on by the ECU 6 and the duty ratio is controlled to be different from that in FIG. 3 (b). In this state, the spool 42 is pressed to the left in FIG. 3C less than in the case of FIG. 3B, and is localized at a position where the restoring force of the spring 43 and the magnetic attractive force of the electromagnetic drive unit 32 are balanced. As a result, the hydraulic oil discharged from the oil pump 4 to the pump passage 75 flows into the sleeve 41 from the opening 414, but the openings 411 and 412 are closed by the lands 421 and 422. It does not flow to the advance passage 85 and the bearing side retard passage 86. That is, since the bearing-side advance passage 85 and the bearing-side retard passage 86 are closed with respect to the oil pump 4, after the hydraulic oil is supplied to the bearing-side advance passage 85 and the bearing-side retard passage 86 described above. The hydraulic oil is retained in the bearing side advance passage 85 and the bearing side retard passage 86.

  Now, the ECU 6 as a control means for controlling the switching valve 31 is specifically constituted by an electric circuit such as a microcomputer. In addition to the coil 36 of the switching valve 31, various sensors such as a sensor 7 for detecting the cam phase and a sensor 8 for detecting the engine speed are electrically connected to the ECU 6 as shown in FIG. The ECU 6 calculates the actual valve timing and the target valve timing of the exhaust valve 97 (see FIG. 4) based on the outputs of these sensors, and controls energization to the coil 36 based on those calculation results.

  A specific example of the sensor 7 is a cam angle sensor that is installed around the camshaft 2 that opens and closes the exhaust valve 97 and detects the rotation angle of the camshaft 2. A specific example of the sensor 8 is a crank angle sensor that is installed around the crankshaft and detects the rotation angle of the crankshaft. Furthermore, in the first embodiment, even if the internal combustion engine is stopped, the power supply from the power source (not shown) of the vehicle to the ECU 6 is continued. Even if the internal combustion engine is stopped, the ECU 6 Can control the energization of the switching valve 31.

Next, the operation of the valve timing adjusting apparatus 1 having the above configuration will be described. When the internal combustion engine is stopped, the stopper piston 26 is fitted to the fitting ring 27 by the restoring force of the compression coil spring 28.
When the stopped internal combustion engine is started, the oil pump 4 is started, and the ECU 6 controls the energization of the coil 36 of the switching valve 31 to open the bearing-side retardation passage 86. Then, the oil discharged from the oil pump 4 flows into the retarded hydraulic chambers 55 to 58 through the bearing side retarded passage 86, the shaft side retarded passage 72, and the retarded passages 65 to 68. As a result, the stopper piston 26 receives the hydraulic pressure from the retarded hydraulic chamber 55 through the passage 291. When the hydraulic pressure rises to a predetermined pressure, the stopper piston 26 comes out of the fitting ring 27. As a result, the vane rotor 14 and the sprocket 11 can be rotated relative to each other.

  Thereafter, the ECU 6 switches the passage communicating with the oil pump 4 among the bearing-side advance passage 85 and the bearing-side retard passage 86 by performing on / off control of energization to the switching valve 31. As a result, when the bearing-side advance passage 85 communicates with the oil pump 4, oil discharged from the oil pump 4 passes through the bearing-side advance passage 85, the shaft-side advance passage 71, and the advance passages 61 to 64. It flows into the chambers 51-54. At this time, the hydraulic oil in the retard hydraulic chambers 55 to 58 is discharged to the drain passage 77 through the retard passages 65 to 68, the shaft side retard passage 72, and the bearing side retard passage 86. As a result, the hydraulic pressure is applied to the vanes 142 to 145 facing the respective advance hydraulic chambers 51 to 54, and the vane rotor 14 rotates relative to the housing 18 in the advance direction X.

  On the other hand, when the bearing-side retard passage 86 communicates with the oil pump 4, the oil discharged from the oil pump 4 passes through the bearing-side retard passage 86, the shaft-side retard passage 72, and the retard passages 65 to 68. Flows into 55-58. At this time, the hydraulic oil in the advance hydraulic chambers 51 to 54 is discharged to the drain passage 76 via the advance passages 61 to 64, the shaft side advance passage 71, and the bearing side advance passage 85. As a result, hydraulic pressure is applied to the vanes 142 to 145 facing the retard hydraulic chambers 55 to 58, and the vane rotor 14 rotates relative to the housing 18 in the retard direction Y.

  As described above, in the first embodiment, by switching the passage for supplying hydraulic oil from the oil pump 4, the hydraulic pressures of the advance hydraulic chambers 51 to 54 and the hydraulic pressures of the retard hydraulic chambers 55 to 58 are adjusted. The relative rotational phase of the vane rotor 14 and thus the valve timing are adjusted. When adjusting the valve timing, the ECU 6 can perform accurate valve timing adjustment by feedback control of the energization to the switching valve 31 so that the actual valve timing of the exhaust valve 97 matches the target valve timing. .

  Under these circumstances, when the internal combustion engine is stopped, the oil pump 4 is also stopped, so that hydraulic oil is not supplied to either the bearing-side advance passage 85 or the bearing-side retard passage 86. Then, the vane rotor 14 is relatively rotated to the most advanced position by the restoring force of the torsion coil spring 22, and the stopper piston 26 is fitted to the fitting ring 27.

  Next, the operation of the valve timing adjusting device 1 relating to the supply passage 87 will be described. When the oil pump 4 is started as the internal combustion engine is started, the oil discharged from the oil pump 4 is always supplied to the supply passage 87. Therefore, oil is supplied from the supply port 871 to the clearance between the camshaft 2 and the cylinder head 82. Then, in the clearance, the portion on the opposite side of the shaft side advance communication port 711 with respect to the shaft side retard communication port 721, that is, the portion between the shaft side retard communication port 721 and the flange portion 83, An oil film is formed. This oil film expands in an annular shape along the outer periphery of the camshaft 2 due to the rotation of the camshaft 2.

  As described above, according to the first embodiment described above, the clearance between the camshaft 2 and the cylinder head 82 includes a portion between the shaft-side retarded communication port 721 and the flange portion 83 along an annular shape. Therefore, the oil film exhibits a sealing function for closing the clearance. Therefore, even if a negative pressure is generated in the shaft-side retarding passage 72, it is possible to prevent air from being sucked into the shaft-side retarding communication port 721 from the clearance portion. Therefore, air mixing into the shaft side retard passage 72 and the retard hydraulic chambers 55 to 58 can be suppressed, and the controllability of the valve timing of the exhaust valve 97 can be improved.

  Here, when the supply port 871 is abolished and a seal member is installed instead of the oil film, the bearing member 80 is provided to secure a space for installing the seal member as compared with the first embodiment in which the supply port 871 is provided. As a result, the total length in the thrust direction of the engine becomes large, and as a result, the total length of the engine increases. Therefore, according to the first embodiment, it is possible to achieve both the suppression of the expansion of the entire engine length and the improvement of the controllability of the valve timing.

  In the first embodiment, the supply port 871 is disposed only on the opposite side of the shaft-side advance communication port 711 with respect to the shaft-side retard communication port 721, and with respect to the shaft-side advance communication port 711. It is not arranged on the opposite side of the shaft side retarded communication port 721. This is because the sliding contact distance L1 from the shaft side advance communication port 711 to the flange portion 84 is longer than the sliding contact distance L2 from the shaft side retard communication port 721 to the flange portion 83. That is, if the slidable contact distance L1 is long, air mixing due to negative pressure is unlikely to occur. Therefore, as in the present embodiment, it is preferable to dispose the supply port 871 on the side with the shorter slidable contact distance L2.

In the first embodiment, the valve timing adjusting device 1 is applied to the roller rocker type driving force transmission system shown in FIG. In the case of this roller rocker type, since the cam 201 is in a rolling contact with the roller 92, the power transmission loss between the exhaust valve 97 and the camshaft 2 is reduced. However, as a contradiction, both the positive reaction force and the negative reaction force received by the camshaft 2 from the exhaust valve 97 become large.
Specifically, the solid line in FIG. 5 shows the torque fluctuation in the case of the roller rocker type, and the dotted line shows the torque fluctuation in the case of the so-called direct hit type in which the cam 201 is in direct contact with the exhaust valve 97. Indicates. Thus, in the case of the roller rocker type, the amplitude of the fluctuation torque is larger on both the positive side and the negative side than in the case of the direct hitting type, and the average value of the fluctuation torque approaches zero.
Therefore, the negative pressure generated in the shaft-side retarded passage 72 is larger than in the direct hitting type. Therefore, according to the first embodiment in which the valve timing adjusting device 1 having the supply port 871 is applied to the roller rocker type driving force transmission system in which such a large negative pressure is generated, air mixing suppression into hydraulic oil is suppressed. An effect can be exhibited suitably.

(Second embodiment)
As shown in FIG. 6, the second embodiment of the present invention is a modification of the first embodiment, and the same components as those in the first embodiment are denoted by the same reference numerals, thereby overlapping description. Is omitted. In the first embodiment, the supply port 871 is disposed only on the opposite side of the shaft side advance communication port 711 with respect to the shaft side retard communication port 721, whereas in the second embodiment, the shaft side advance A supply port 871 is also arranged on the opposite side of the shaft side retard communication port 721 with respect to the corner communication port 711.

  Therefore, according to the second embodiment, in addition to the portion between the shaft-side retarded communication port 721 and the flange portion 83 in the clearance between the camshaft 2 and the cylinder head 82, the shaft-side advanced communication port 711 and the flange are provided. An annular oil film that exhibits a sealing function is also formed between the portion 84 and the portion 84. Therefore, in addition to suppressing the air mixing into the shaft side retarding passage 72 and the retarding hydraulic chambers 55 to 58, the air mixing into the shaft side leading passage 71 and the advance hydraulic chambers 51 to 54 can also be suppressed. The controllability of the valve timing of the valve or exhaust valve 97 can be further improved.

(Third embodiment)
As shown in FIG. 7, the third embodiment of the present invention is a modification of the second embodiment, and the same components as those in the second embodiment are denoted by the same reference numerals, thereby overlapping description. Is omitted. In the second embodiment described above, the supply port 871 has a shape that opens to face only a part of the outer peripheral surface, and therefore the oil film formed on the camshaft 2 is separated from the supply port 871 by the rotation of the camshaft 2. It extends in an annular shape along the outer periphery of the camshaft 2.
On the other hand, in the third embodiment, the bearing cap supply groove 872 that extends annularly along the circumferential direction of the camshaft 2 is formed in the cam cap 81 and the cylinder head 82. The bearing side supply groove 872 communicates with the supply port 871. Further, the cross-sectional shape of the bearing side supply groove 872 is a shape in which the cross section of the passage becomes larger in the thrust direction as it approaches the camshaft 2 from the bearing member 80 side as shown in FIG.

  According to the third embodiment having the above configuration, the bearing-side supply groove 872 extending annularly is provided, so that oil is supplied to the camshaft 2 from the entire circumference. Therefore, since it is possible to reliably realize the oil film having an annular shape extending along the outer periphery of the camshaft 2, it is possible to improve the sealing performance of the oil film that exhibits a sealing function. Further, since the cross-sectional shape of the bearing side supply groove 872 is a shape in which the passage cross section gradually increases in the thrust direction, the length of the oil film in the thrust direction can be increased without increasing the diameter of the supply passage 87. Therefore, the sealing performance can be further improved.

(Fourth embodiment)
As shown in FIG. 8, the fourth embodiment of the present invention is a modification of the third embodiment, and the same components as those in the third embodiment are denoted by the same reference numerals so as to overlap each other. Is omitted. In the above-described third embodiment, the bearing-side supply groove 872 is formed in the bearing member 80, whereas in the fourth embodiment, the camshaft 2 is provided with a shaft extending annularly along the circumferential direction of the camshaft 2. A side supply groove 873 is formed. The shaft side supply groove 873 communicates with the supply port 871. Incidentally, the cross-sectional shape of the shaft side supply groove 873 is such that the cross section of the passage becomes larger in the thrust direction as it approaches the camshaft 2 from the bearing member 80 side as shown in FIG.

  According to the fourth embodiment having the above-described configuration, since the shaft-side supply groove 873 extending in an annular shape is provided, the oil supplied from the supply port 871 is accumulated in the shaft-side supply groove 873 and is accumulated on the camshaft 2 by the accumulated oil. An oil film will be formed. Therefore, since it is possible to reliably realize the oil film having an annular shape extending along the outer periphery of the camshaft 2, it is possible to improve the sealing performance of the oil film that exhibits a sealing function.

(Fifth embodiment)
As shown in FIG. 9 and FIG. 10, the fifth embodiment of the present invention is a modification of the first embodiment, and components that are substantially the same as those of the first embodiment are denoted by the same reference numerals. A duplicate description is omitted. In the first embodiment described above, the supply port 871 is arranged in the cylinder head 82, whereas in the fifth embodiment, the supply port 871 is arranged in the cam cap 81 as shown in FIG.

  In the first embodiment, the valve timing adjusting device 1 is applied to the exhaust valve 97. In the fifth embodiment, the valve timing adjusting device 1 is applied to the intake valve. Therefore, the torsion coil spring 22 shown in FIG. 1 is abolished. In the fifth embodiment, as shown in FIG. 9, the power of the crankshaft 203 that is a drive shaft is transmitted to the camshaft 2 that is a driven shaft by a chain 204. An arrow F1 in FIG. 9 indicates the direction of the tension that the sprocket 11 of the apparatus main body 10 receives from the chain 204, and an arrow F2 indicates the direction of the force that the camshaft 2 receives by the tension F1.

  As shown in FIG. 10, in the fifth embodiment, the supply port 871 is disposed on the opposite side of the rotation center O of the camshaft 2 from the direction of the force F2 that the camshaft 2 receives in the radial direction from the chain 204. Yes. As shown in FIG. 10, a supply passage 874 having a supply port 871 is formed in the cam cap 81, and the supply passage 874 communicates with a supply passage 87 formed in the cylinder head 82. Further, the processing hole of the supply passage 874 is closed with a sealing plug 875.

  Here, regarding the radial clearance 876 (see FIG. 10) formed between the camshaft 2 and the bearing member 80, the force F2 that the camshaft 2 receives in the radial direction with respect to the rotation center O of the camshaft 2 is shown. The clearance 876 is maximized at the opposite side portion. Therefore, according to the fifth embodiment in which the supply port 871 is positioned at the portion where the clearance 876 is maximized in this way, oil can easily enter between the camshaft 2 and the bearing member 80, and the camshaft 2 The oil film easily spreads along the outer periphery. Therefore, the sealing performance of the oil film that exhibits the sealing function can be improved.

(Other embodiments)
In each of the above embodiments, the oil pump 4 is installed in the cylinder head 82, but the oil pump 4 may be installed in the cam cap 81. Further, for example, when the supply port 871 is arranged in the cam cap 81 as in the fifth embodiment, the supply passage 87 may be eliminated and oil may be supplied directly from the oil pump 4 to the supply passage 874. .

  In each of the above embodiments, the valve timing adjusting device 1 is applied to a roller rocker type driving force transmission system, but the valve timing adjusting device 1 may be applied to a direct driving type or other driving force transmission system.

  In the fifth embodiment, the power of the crankshaft 203 is transmitted to the camshaft 2 using the chain 204, but a belt or a gear may be used. In the case of using a belt, instead of supplying oil from the oil pump 4 that supplies oil to the bearing side advance passage 85 and the bearing side retard passage 86 to the supply passage 87, the tension of the belt is set. Oil may be supplied to the supply passage 87 from a pump that supplies oil to the hydraulic tensioner to be controlled.

Here, when a gear is used for power transmission to the camshaft 2 as described above, when a gear is used as the gear, the camshaft 2 receives a force in the thrust direction from the gear. It will be. Then, one of the flange portions 83 and 84 that abut against the bearing member 80 in the thrust direction is pressed against the bearing member 80 by the force received from the helical gear, and the thrust member is thrust between the other flange portion and the bearing member 80. Increases the clearance in the direction.
Therefore, if the supply port 871 is arranged on the opposite side of the direction of the force that the camshaft 2 receives in the thrust direction with respect to the shaft side advance communication port 711 and the shaft side retard communication port 721, the clearance increases as described above. The supply port 871 is located on the side. As a result, oil can easily enter between the camshaft 2 and the bearing member 80, and the oil film can easily spread along the outer periphery of the camshaft 2. Therefore, the sealing performance of the oil film that exhibits the sealing function can be improved.

By the way, the negative pressure generated in one of the shaft-side advance passage 71 and the shaft-side retard passage 72 may be extremely smaller than the negative pressure generated in the other passage due to engine characteristics or the like. . For example, when the torque shown in FIG. 5 is larger on the positive side than on the negative side, the vane rotor 14 easily swings toward the advance hydraulic chamber 51 due to the reaction force received by the camshaft 2. In this case, in order to set the hydraulic pressure in the advance hydraulic chamber 51 high, even if the vane rotor 14 swings toward the retard hydraulic chamber 57, negative pressure is applied to the advance hydraulic chamber 51 and the shaft side advance passage 71. Is less likely to occur. Accordingly, in such a case, the supply port 871 on the opposite side of the shaft side retarded communication port 721 with respect to the shaft side advance communication port 711 is eliminated, and the shaft side with respect to the shaft side retard communication port 721 is eliminated. It is preferable that the supply port 871 is provided only on the side opposite to the advance communication port 711.
As described above, the present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof.

The block diagram which shows the valve timing adjustment apparatus by 1st embodiment of this invention. II-II arrow line view of FIG. The schematic diagram for demonstrating the action | operation of the switching valve by 1st embodiment. The schematic diagram for demonstrating the driving force transmission system by 1st embodiment. The figure which shows the relationship between the fluctuation | variation of the torque which the cam shaft by 1st embodiment receives, and the rotation angle of a cam. The block diagram which shows the valve timing adjustment apparatus by 2nd embodiment of this invention. The block diagram which shows the valve timing adjustment apparatus by 3rd embodiment of this invention. The block diagram which shows the valve timing adjustment apparatus by 4th embodiment of this invention. The schematic diagram for demonstrating the driving force transmission system by 5th embodiment of this invention. Sectional drawing for demonstrating the position of the supply port by 5th embodiment.

Explanation of symbols

  1: valve timing adjusting device, 2: camshaft, 14: vane rotor, 18: housing, 51: advance hydraulic chamber, 55: retard hydraulic chamber, 71: shaft advance passage, 72: shaft retard passage, 80: bearing member, 81: cam cap, 82: cylinder head, 85: bearing side advance passage, 86: bearing side retard passage, 87: supply passage, 97: exhaust valve, 203: drive shaft, 711: shaft side Advance communication port, 721: Shaft side retard communication port, 871: Supply port, 872: Bearing side supply groove, 873: Shaft side supply groove.

Claims (6)

A valve timing adjusting device that is provided in a driving force transmission system that transmits a driving force of a driving shaft of an internal combustion engine to at least one of an intake valve and an exhaust valve, and adjusts an opening / closing timing of at least one of the intake valve and the exhaust valve. And
A hydraulic supply source;
A camshaft having a shaft-side advance passage and a shaft-side retard passage, which is rotationally driven by the driving force of the drive shaft, and which drives at least one of the intake valve and the exhaust valve;
A bearing member for supporting the camshaft in a radial direction, a bearing- side advance passage communicating with the shaft-side advance passage, a bearing-side retard passage communicating with the shaft-side retard passage, and the camshaft; A bearing member having a supply passage for supplying oil to the clearance with the bearing member ;
A housing that rotates in conjunction with one of the drive shaft and the camshaft;
Rotating in conjunction with the other of the drive shaft and the camshaft, forming an advance hydraulic chamber and a retard hydraulic chamber between the housing and the hydraulic supply source from the bearing side advance passage and the shaft side advance passage and the hydraulic is supplied to the advancing hydraulic chamber via, and from said hydraulic pressure supply source to the retard hydraulic chamber via said shaft-side retarding passage and the bearing-side retarding passage provided A vane rotor that is driven to rotate relative to the housing by a supplied hydraulic pressure,
The shaft side advance communication port that opens to the bearing side advance passage in the shaft side advance passage, the shaft side retard communication port that opens to the bearing side retard passage in the shaft side retard passage , and the Supply ports that open to the clearance between the camshaft and the bearing member in the supply passage are arranged side by side in the thrust direction of the camshaft, and the supply port is connected to the negative pressure of the shaft side advance communication port. The negative pressure of the shaft side retarded communication port is compared, and the negative pressure is relative to the shaft side advanced angle communication port and the communication port that generates a relatively large negative pressure in the shaft side retarded angle communication port. Is arranged on the opposite side of the communication port that occurs at a small distance, or on both sides of the shaft side advance communication port and the shaft side retard communication port,
The valve timing adjusting device according to claim 1, wherein the supply passage is directly connected to the hydraulic pressure supply source .   2. The valve timing adjusting device according to claim 1, further comprising a bearing-side supply groove formed in the bearing member, extending annularly along a circumferential direction of the camshaft, and communicating with the supply port.   2. The valve timing adjusting device according to claim 1, further comprising a shaft-side supply groove formed on the camshaft and extending annularly along a circumferential direction of the camshaft and communicating with the supply port.   The valve according to any one of claims 1 to 3, wherein the supply port is located on a side opposite to a direction of a force that the camshaft receives in a radial direction from the driving force transmission system with respect to a rotation center of the camshaft. Timing adjustment device.   The supply port is located on the opposite side of the direction of the force that the camshaft receives in the thrust direction from the driving force transmission system with respect to the shaft side advance communication port and the shaft side retard communication port. The valve timing adjusting device according to any one of claims 4 to 4. A rocker arm that swings with the rotation of the camshaft to drive at least one of the intake valve and the exhaust valve;
A roller rotatably attached to the rocker arm and in rolling contact with the cam of the camshaft;
The valve timing adjusting device according to any one of claims 1 to 5, wherein the valve timing adjusting device is provided in the driving force transmission system.

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