JP2000008814A - Valve timing regulation device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constrain a vane rotor and a timing gear without separately providing a hydraulic chamber or an oil path only for constraining the turning of the vane rotor and the timing gear at a specific constraining position. SOLUTION: When no hydraulic pressure is applied to an advance angle side hydraulic chamber or a delay angle side hydraulic chamber, a covering plate 45 is urged by the urging force of a spring 46a to constrain the relative turn between a timing gear 24a and a vane rotor 41 by the friction force generated between the vane rotor 41 and the covering plate 45. When the hydraulic pressure is applied to the advance angle side hydraulic chamber and the delay angle side hydraulic chamber, the covering plate 45 is moved by the hydraulic pressure against the urging force of the spring 46a to release the constraint of the relative turn. The relative turn between the timing gear 24a and the vane rotor 41 can be constrained or released in a switching manner, and the cost can be reduced thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing adjusting device for an internal combustion engine, and more particularly, to a valve timing adjusting device for an internal combustion engine that changes the opening / closing timing of a valve in the internal combustion engine according to an operating state.

[0002]

2. Description of the Related Art A camshaft is driven through a timing pulley or a chain sprocket that rotates synchronously with a crankshaft, and the timing pulley or the chain sprocket and the camshaft are rotated relative to each other to change the valve opening / closing timing in an internal combustion engine. Japanese Patent Application Laid-Open No. 9-6050 discloses a variable valve timing device of the type.
No. 8 is known.

In the variable valve timing device disclosed in Japanese Patent Application Laid-Open No. 9-60508, a chain sprocket and a camshaft are connected by a vane rotor, and the vane rotor is fixed to the camshaft. The vane rotor is provided so as to be rotatable relative to the chain sprocket, so that the driving force from the crankshaft is transmitted to the camshaft, and the camshaft is rotatable with respect to the chain sprocket in the advance or retard direction.

[0004] A stopper piston is housed in the vane rotor, and a housing member which forms a space for accommodating the vane rotor together with the chain sprocket has a stopper when the vane rotor is at the most retarded position with respect to the chain sprocket. A hole into which the pin can be fitted is provided. The stopper piston is urged in the direction of the housing member by a spring. With this configuration, in a state where the pressure acting on the vane rotor has not reached a predetermined pressure at which the chain sprocket and the vane rotor can rotate relative to each other, the stopper piston is urged by the spring and fitted into the hole. Therefore, the housing member and the vane rotor are fixed, so that collision between the housing member and the vane rotor can be prevented, and occurrence of a tapping sound can be prevented.

[0005]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No.
In the variable valve timing device described in Japanese Patent No. -60508, a hydraulic chamber and an oil passage are formed around a stopper piston provided on the vane rotor to operate the stopper piston. For this reason, there is a problem that the structure becomes complicated, the number of processing steps increases, and the cost increases.

[0006] In view of such a conventional problem,
According to the present invention, the first rotating body and the second rotating body are restrained without separately providing a hydraulic chamber or an oil passage only for restraining the rotation of the first rotating body and the second rotating body at a predetermined restraining position. by doing,
It is an object of the present invention to provide a valve timing adjusting device for an internal combustion engine that can constitute a restraining means with a simple structure.

[0007]

Therefore, in order to achieve the above object, according to the first aspect of the present invention, a first rotating body having at least one concave portion on an inner peripheral surface, and a first rotary member having a concave portion are provided. A second rotating body that has at least one vane partitioned into one pressure chamber and a second pressure chamber and that is combined with the first rotating body so as to be relatively rotatable; a cover that covers a side surface of the first rotating body; A drive shaft for synchronously rotating one of the first rotating body or the second rotating body at a reference rotation phase of the internal combustion engine, a driven shaft interlocked with the other of the first rotating body or the second rotating body, The first pressure chamber and the second pressure chamber
In a valve timing adjusting device for an internal combustion engine, comprising a relative rotation means for relatively rotating the first rotating body and the second rotating body by a pressure applied to a pressure chamber, the cover is made of an elastic material, and The first rotator and the second rotator are restrained by a frictional force generated between the cover and the second rotator by being urged by the rotator, and the cover includes the first pressure chamber and the second rotator. The gist of the invention is to move against the urging force of the elastic body by the pressure applied to the two pressure chambers and release the constraint between the first rotating body and the second rotating body.

According to the second aspect of the present invention, the first rotating body having at least one concave portion on the inner peripheral surface,
A second rotating body that has at least one vane partitioned into a pressure chamber and a second pressure chamber and that is rotatably combined with the first rotating body; a cover that covers a side surface of the first rotating body; A drive shaft for synchronously rotating one of the one rotating body or the second rotating body at a reference rotation phase of the internal combustion engine, a driven shaft interlocked with the other of the first rotating body or the second rotating body, A relative rotation unit configured to relatively rotate the first rotator and the second rotator by a pressure applied to the first pressure chamber and the second pressure chamber; The gist is to provide a magnet for restraining relative rotation.

According to a third aspect of the present invention, in the valve timing adjusting device for an internal combustion engine according to the second aspect, the magnet is provided on one of the first rotating body and the second rotating body, and the magnet is an elastic body. The gist is that it is being energized by the other.

According to the first aspect of the present invention, the first
When the hydraulic pressure is not acting on the pressure chamber and the second pressure chamber,
The cover is urged by the elastic body toward the second rotating body, and restrains relative rotation between the first rotating body and the second rotating body by a frictional force generated between the cover and the second rotating body. When hydraulic pressure acts on the first pressure chamber and the second pressure chamber, the cover moves against the urging force of the elastic body due to the hydraulic pressure, and releases the restriction of the relative rotation. Thus, according to the first aspect of the present invention, the relative rotation between the first rotator and the second rotator is restricted by the urging force of the elastic member, and the first rotator and the second rotator are relatively rotated. The first rotation body and the second rotation body are released because the relative rotation between the first rotation body and the second rotation body is released by utilizing the pressure of the first pressure chamber and the pressure of the second pressure chamber. It is not necessary to separately provide a hydraulic chamber or an oil passage only for restraining the rotation of the shaft at a predetermined restraining position. Accordingly, the relative rotation between the first rotating body and the second rotating body can be restrained and the restraint can be switched with a simple structure, and the cost can be reduced.

According to the second aspect of the present invention, the first
When the hydraulic pressure is not acting on the pressure chamber and the second pressure chamber,
The relative rotation between the first rotator and the second rotator is restricted by the magnetic force of the magnet. When a hydraulic pressure acts on the first pressure chamber and the second pressure chamber, the hydraulic pressure causes the magnet and the first rotating body or the second rotating body to move.
An oil film is formed between the rotating bodies to release the restriction of the relative rotation. As described above, according to the second aspect of the invention, the relative rotation between the first rotating body and the second rotating body is restrained by the magnetic force of the magnet, and the first rotating body and the second rotating body are relatively rotated. The relative rotation between the first rotating body and the second rotating body is released using the fluid in the first pressure chamber and the fluid in the second pressure chamber for the first rotating body and the second rotating body. It is not necessary to separately provide a hydraulic chamber or an oil passage only for restricting the rotation of the hydraulic cylinder at a predetermined restriction position. Accordingly, the relative rotation between the first rotating body and the second rotating body can be restrained and the restraint can be switched with a simple structure, and the cost can be reduced.

According to the third aspect of the present invention, the first
When the hydraulic pressure is not acting on the pressure chamber and the second pressure chamber,
The first rotator and the second rotator are magnetized by an elastic body.
Restrict the relative rotation of the rotating body. When a hydraulic pressure acts on the first pressure chamber and the second pressure chamber, a pressure acts on the magnet due to the hydraulic pressure, and the magnet moves against the urging force of the elastic body to release the restriction of the relative rotation. Thus, in the invention of claim 3, when pressure acts on the magnet, the magnet separates from the first rotating body or the second rotating body against the urging force of the elastic body.
This makes it less likely to be affected by the contact state of the second rotating body when the restraint is released, improves responsiveness, and allows accurate control of valve timing.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a valve timing adjusting device for an internal combustion engine according to the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view showing an internal combustion engine (hereinafter referred to as an engine) to which the valve timing adjusting device for an internal combustion engine according to the present embodiment is applied. In this figure, an engine 11 includes a cylinder block 13 in which a piston 12 is reciprocally movable and a cylinder block 1.
3 and an oil pan 13a provided above the cylinder block 13 and a cylinder head 14 provided above the cylinder block 13. The pistons 12 are provided corresponding to four cylinders of the engine 11 (only one cylinder is shown in FIG. 1).

A crankshaft 15 as an output shaft is rotatably supported below the engine 11, and the crankshaft 15 is connected to a piston 12 via a connecting rod 16.
Are connected. The reciprocating motion of the piston 12 is converted by the connecting rod 16 into rotation of the crankshaft 15. A combustion chamber 17 is provided above the piston 12. An intake port 18 and an exhaust port 19 are connected to the combustion chamber 17. The intake port 18 and the combustion chamber 17 are communicated and shut off by the opening and closing operation of the intake valve 20, and the exhaust port 19 and the combustion chamber 17 are communicated and shut off by the opening and closing operation of the exhaust valve 21.

On the other hand, an intake camshaft 22 and an exhaust camshaft 23 are provided on the cylinder head 14 in parallel and rotatably. At one end of the intake camshaft 22, there is provided a variable valve timing mechanism 24 provided with a timing gear 24a as relative rotation means for rotating relative to the intake camshaft 22.
A timing gear 25 is attached to one end of 3. The timing gear 25 and the timing gear 24a of the variable valve timing mechanism 24 are connected via a timing chain 26 to a timing gear attached to the crankshaft. Then, the rotation of the crankshaft 15 is transmitted to the intake camshaft 22 and the exhaust camshaft 23 via the timing chain, whereby the intake camshaft 22 and the exhaust camshaft 23 rotate.

The intake camshaft 22 and the exhaust camshaft 23 have an intake cam 27 in contact with the upper end of the intake valve 20 and an exhaust cam 28 in contact with the upper end of the exhaust valve 21.
Are provided respectively. When the intake camshaft 22 and the exhaust camshaft 23 rotate, the intake cam 27 and the exhaust cam 28 open and close the intake valve 20 and the exhaust valve 21. When the piston 12 descends during the intake process of the engine 11, the intake valve 20 is opened, and air is sucked into the combustion chamber 17 from the intake port 18. Further, when the piston 12 is raised during the exhaust process, the exhaust valve 21 is opened, and the exhaust gas is discharged from the combustion chamber 17 to the exhaust port 19.

Next, the variable valve timing mechanism 24 according to the first embodiment will be described. FIG. 2 shows the first
FIG. 2 is an enlarged view showing a specific configuration of a valve timing adjustment device for an internal combustion engine according to the embodiment. In this figure, a journal 22a of an intake camshaft 22 provided with a valve timing adjustment mechanism 24 is rotatably supported by a bearing portion 14a of a cylinder head 14. The tip of the intake camshaft 22 passes through the center of the timing gear 24a. This timing gear 24a is rotatable with respect to the intake camshaft 22. Also, on the tip surface of the intake camshaft 22,
A vane rotor 41 as a second rotating body is fixed by bolts 42, and the vane rotor 41 rotates integrally with the intake camshaft 22 about the axis L of the intake camshaft 22.

On the other hand, a shoe housing 43 as a first rotating body provided so as to cover the vane rotor 41 is in contact with the tip end surface of the timing gear 24a. The shoe housing 43 includes a ring cover 44 provided so as to surround the outer periphery of the vane rotor 41, and a closing plate 45 provided so as to close a distal end opening of the ring cover 44 and cover a part of the outer periphery of the ring cover 44. It is composed of An oil seal 45a is provided between the ring cover 44 and the closing plate 45. The length of the ring cover 44 in the axial direction is shorter than the length of the vane rotor 41 in the axial direction, and the portion of the vane rotor 41 protruding from the ring cover 44 forms an extension 41a. Then, the timing gear 24a and the ring cover 4
4. The closing plate 45 is connected via a spring 46a as an elastic body so as to be integrally rotatable about an axis L of the intake camshaft 22 by a bolt 46. In addition, the closing plate 45 as a frictional resistance portion and the extension portion 41
a, the bolt 46, and the spring 46a can restrict the relative rotation between the vane rotor 41 and the timing gear 24a.

A variable valve timing mechanism 2 is mounted on the bearing portion 14a of the cylinder head 14, the intake camshaft 22, and the like.
An advance control oil passage 47 and a retard control oil passage 48 for supplying oil to the engine 4 are provided. The advance control oil passage 47 and the retard control oil passage 48 extend to the inside of the variable valve timing mechanism 24 and
4 is connected to an oil control valve (OCV) 49 through the inside of the bearing portion 14a. In addition, OCV49
Is connected to a supply passage 50 and a discharge passage 51. The supply passage 50 is connected to an oil pan 13a provided at a lower portion of the engine 11 via an oil pump 52 driven by the rotation of the crankshaft 15, and the discharge passage 51 is directly connected to the oil pan 13a. linked.

The OCV 49 has a casing 56, and the casing 56 has a first supply / discharge port 57 and a second supply / discharge port 58, and a first discharge port 59 and a second discharge port 60.
And a supply port 61. The first supply / discharge port 57 communicates with the retard control oil passage 48, and the second supply / discharge port 58 communicates with the advance control oil passage 47. Further, the supply port 61 communicates with the supply port 61, and the discharge port 5
9. The discharge port 51 communicates with the discharge port 60.
In the casing 56, a spool 63 having four valve portions and urged in opposite directions by a coil spring 62 and an electromagnetic solenoid 65 is provided.

When the electromagnetic solenoid 65 is in the demagnetized state, the spool 63 is disposed at one end of the casing 56 by the urging force of the coil spring 62, and the first supply / discharge port 57 and the discharge port 59 communicate with each other. The two supply / discharge ports 58 communicate with the supply port 60. In this state,
The oil in the oil pan 13a is sent from the oil pump 52 to the advance control oil passage 47 through the supply passage 50 and the OCV 49, and the oil in the retard control oil passage 48 passes through the OCV 49 and the discharge passage 51. Oil pan 13a
It is returned inside.

Further, when the voltage application to the electromagnetic solenoid 65 is duty-controlled and the spool 63 is positioned in the middle of the casing 56, the first supply / discharge port 57 and the second supply / discharge port 58 are closed, and the first supply / discharge port is provided. The movement of oil through the port 57 and the second supply / discharge port 58 is prohibited.

Next, the detailed structure of the vane rotor 41 and the shoe housing 43 in the variable valve timing mechanism 24 will be described. FIG. 3 is a sectional view taken along line AA in FIG. In this figure, the inner peripheral surface of the ring cover 44 in the shoe housing 43 has the intake camshaft 22
Four shoes 6 of the same shape projecting toward the axis L of
6 are formed at equal intervals in the circumferential direction of the shoe housing 43. A fan-shaped space 67 is provided between each shoe 66.
Are formed at equal intervals in the circumferential direction of the housing 43.
The fan-shaped space 67 is provided on the outer peripheral surface of the vane rotor 41.
The four vanes 68 of the same shape protruding outward so as to be inserted into the vane rotor 41 are provided at equal intervals in the circumferential direction of the vane rotor 41. Fan-shaped space 6 into which each vane 68 is inserted
The inside of the chamber 7 is partitioned by a vane 68 into an advanced hydraulic chamber 69 as a first pressure chamber and a retard hydraulic chamber 70 as a second pressure chamber. Advance hydraulic chamber 69 and retard hydraulic chamber 70
Are located so as to sandwich the vane 68 from both sides in the circumferential direction of the vane rotor 41. The advance-side hydraulic chamber 69 and the retard-side hydraulic chamber 70 communicate with an advance control oil passage 47 and a retard control oil passage 48, respectively.

A seal member 71 is provided on the outer peripheral wall of the vane 68. A small clearance has to be provided between the outer peripheral wall of the vane rotor 41 and the inner peripheral wall of the shoe housing 43 for the purpose of assembly.
1 prevents it. The sealing member 71 includes a leaf spring 7.
The urging force of No. 2 pushes the inner peripheral wall of the shoe housing 43.

Next, detailed configurations of the advance control oil passage 47 and the retard control oil passage will be described. As shown in FIG. 2, the advance control oil passage 47 includes a head oil passage 47a, an oil groove 47b, an oil hole 47c, a shaft oil passage 47d, an oil hole 47e, an annular space 47f, and an oil hole 47g.

The head oil passage 47a is connected to the cylinder head 14
The oil groove 4 is formed on the outer peripheral surface of the journal 22a of the intake camshaft 22 through the inside of the bearing portion 14a
7b. The oil groove 47b communicates with a shaft oil passage 47d passing through the inside of the intake camshaft 22 in the axial direction through an oil hole 47c formed in the intake camshaft 22. The shaft oil passage 47d communicates with an annular space 47f provided around the bolt 42 in the vane rotor 41 via an oil hole 47e formed in the vane rotor 41. The annular space 47f and the advance hydraulic chamber 69 communicate with each other through an oil hole 47g.

On the other hand, the retard control oil passage 48 is connected to the head oil passage 4
8a, oil groove 48b, oil hole 48c, shaft oil passage 48d,
It is constituted by an oil hole 48e, an annular space 48f and an oil hole 48g.

The head oil passage 48a is connected to the cylinder head 14
The oil groove 4 is formed on the outer peripheral surface of the journal 22a of the intake camshaft 22 through the inside of the bearing portion 14a
8b. The oil groove 48b communicates with a shaft oil passage 48d passing through the inside of the intake camshaft 22 in the axial direction through an oil hole 48c formed in the intake camshaft 22. This shaft oil passage 48d is formed via an oil hole 48e formed in the intake camshaft 22.
Oil groove 48f formed on the inner peripheral surface of timing gear 24a
Is in communication with The oil groove 48f and the retard hydraulic chamber 70 communicate with each other through an oil hole 48g.

In such a variable valve timing mechanism, when the electromagnetic solenoid 65 of the OCV 49 is demagnetized,
Oil is supplied from the advance angle control oil passage 47 to the advance angle side hydraulic chamber 69, and the retard angle control oil passage 4
The oil is discharged via 8. As a result, each vane 6
8 moves relative to the direction of arrow A, the vane rotor relatively rotates in the direction of arrow A, and the relative rotational phase of the intake camshaft 22 with respect to the timing gear 24a is changed. The timing gear 24a and the intake camshaft 22 rotate in the direction of arrow A. Therefore, in this case, the intake camshaft 22 advances with respect to the timing gear 24a, and the valve timing of the intake valve 20 also advances.

When the electromagnetic solenoid 65 of the OCV 49 is excited, the retard control oil passage 48
And the oil is discharged from the advance side hydraulic chamber 69 via the advance control oil passage 47. As a result, as each vane 68 moves relatively in the direction of arrow B, the vane rotor 41 relatively rotates in the direction of arrow B, and the relative rotational phase of the intake camshaft 22 with respect to the timing gear 24a is changed. Therefore, in this case, the intake camshaft 22 is retarded with respect to the timing gear 24a,
The valve timing of the intake valve 20 is also advanced.

Next, the operation of the variable valve timing mechanism 24 according to the first embodiment will be described with reference to FIGS. FIG. 4 is an enlarged view of the portion C in FIG. 2 when restrained. FIG. 5 is an enlarged view of the part C in FIG. 2 when the restraint is released. When the oil is not introduced from the oil pump 52 into the advance hydraulic chamber 69 and the retard hydraulic chamber 70 at the start of the engine, the vane rotor 41 moves with respect to the shoe housing 43 as shown in FIG. It is at the most retarded position shown. At this time, the extension 41a
Is in contact with the closing plate 45 as shown in FIG. 4, and the closing plate 45 is urged toward the vane rotor 41 by a spring 46a, and the urging force of the spring 46a is used as a drag.
A frictional force is generated in a circumferential direction on a surface where the vane rotor 41 and the closing plate 45 are in contact with each other. The vane rotor 41 is restrained by the shoe housing 43 by the frictional resistance repelling the frictional force.

After the engine is started, oil is supplied from the oil pump 52 to each of the retard hydraulic chambers 70, and hydraulic pressure acts on the closing plate 45. When the oil pressure in each of the retard side hydraulic chambers 70 is equal to or higher than a predetermined pressure, that is, when the oil pressure acting on the closing plate 45 is equal to or higher than the predetermined pressure, the closing plate 45 is pressed against the urging force of the spring 46a. 5, the vane rotor 41 moves in the direction opposite to the vane rotor 41, and the vane rotor 41 and the closing plate 4 move.
5, a clearance a is created between the vane rotor 41 and the shoe housing 43, that is, the contact between the extension portion 41 a and the closing plate 45 is released. Thus, the vane rotor 41 can rotate relative to the shoe housing 43. Note that the clearance a is a clearance that can ensure the sealing performance between the advance hydraulic chamber 69 and the retard hydraulic chamber 70.

Further, in order to rotate the vane rotor 41 from the most retarded position shown in FIG. 3 to the advanced side, the OCV 49 is switched to open each retarded side hydraulic chamber 70, and the oil is supplied to each advanced side hydraulic chamber 69. Supply. Also at this time, the hydraulic pressure acts on the closing plate 45 via the advance hydraulic chambers 69, so that the release of the restraint between the vane rotor 41 and the shoe housing 43 is maintained. When the hydraulic pressure in each advance-side hydraulic chamber 69 becomes equal to or higher than a predetermined pressure, the vane rotor 41 rotates from the most retarded position to the advanced side.

Thereafter, the EC according to the engine operating state
The OCV 49 is switched by an instruction from the U to control the hydraulic pressure of each advance-side hydraulic chamber 69 and each retard-side hydraulic chamber 70, and the rotational phase difference of the vane rotor 41 with respect to the shoe housing 43, that is, the intake camshaft 22 with respect to the crankshaft 15. Is controlled. Thereby, the valve timing of the intake valve 20 can be controlled with high accuracy.

As described above, in the valve timing adjusting device for the internal combustion engine according to the first embodiment, when the hydraulic pressure is not acting on the advance hydraulic chamber 69 and the retard hydraulic chamber 70, the closing plate 45 is closed. The timing gear 2 is urged against the vane rotor 41 by the urging force of the spring 46a and generated by the frictional force between the vane rotor 41 and the closing plate 45.
4a and the relative rotation of the vane rotor 41 are restrained. When hydraulic pressure acts on the advance hydraulic chamber 69 and the retard hydraulic chamber 70, the hydraulic plate moves the closing plate 45 against the urging force of the spring 46a to release the restriction of relative rotation. Therefore, the relative rotation between the timing gear 24a and the vane rotor 41 is restricted by the urging force of the spring 46a, and the advance hydraulic chamber 69 and the retard hydraulic chamber 70 for relative rotating the timing gear 24a and the vane rotor 41 are used.
, The relative rotation between the timing gear 24a and the vane rotor 41 is released, so that a hydraulic chamber only for restricting the rotation between the timing gear 24a and the vane rotor 41 at a predetermined restriction position is provided. There is no need to provide a separate oil passage. Thus, the relative rotation between the timing gear 24a and the vane rotor 41 can be restrained and the restraint can be switched with a simple structure, and the cost can be reduced.

Further, since there is no means for restraining the vane rotor 41 on the surface where the closing plate 45 abuts on the vane rotor 41, and there is no means for restraining the inside of the vane rotor 41 as in the prior art, each vane 6 of the vane rotor 41 is provided.
8 can be made uniform, and the rotational balance of the vane rotor can be stabilized. Further, since the oil passage for operating the restraining means as in the related art is not provided in the vane rotor 41, the sealing performance between the advance hydraulic chamber 69 and the retard hydraulic chamber 70 can be improved. it can.

Next, a second embodiment will be described. FIG. 6 is an enlarged view showing a specific configuration of a valve timing adjustment device for an internal combustion engine according to the second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals. In this figure, an intake camshaft 22 provided with a valve timing adjustment mechanism 224 is shown.
The journal 22 a is rotatably supported by a bearing portion 14 a of the cylinder head 14. The tip of the intake camshaft 22 passes through the center of the timing gear 224a. The timing gear 224a is rotatable with respect to the intake camshaft 22.
A vane rotor 241 is fixed to a tip end surface of the intake camshaft 22 with bolts 242, and the vane rotor 241 is configured to rotate integrally with the intake camshaft 22 about an axis L of the intake camshaft 22.
The vane rotor 241 is made of a magnetic material such as iron.

On the other hand, a shoe housing 243 provided so as to cover the vane rotor 241 is in contact with the tip end surface of the timing gear 224a. The shoe housing 243 includes a ring cover 244 provided so as to surround the outer periphery of the vane rotor 241, and a closing plate 245 provided so as to close the opening at the distal end of the ring cover 244. Further, on the side of the vane rotor 241 of the timing gear 224a, facing the vane rotor 241,
A concave portion 24b is formed, and a magnet 31 which is a permanent magnet is fitted into the concave portion 24b. Then, the timing gear 224a, the ring cover 244, the closing plate 245
Are connected by bolts 246 so that they can rotate integrally about the axis L of the intake camshaft 22.
The relative rotation between the vane rotor 241 and the timing gear 224a can be restricted by the magnet 31.

Next, the operation of the variable valve timing mechanism 224 according to the second embodiment will be described with reference to FIGS. FIG. 7 is an enlarged view of the portion D in FIG. 6 when it is restrained. FIG. 8 is an enlarged view at the time of releasing the restraint of the D portion in FIG. Note that the cross-sectional view taken along the line AA in FIG. 6 has the same configuration as that of FIG. When the oil has not been introduced from the oil pump 52 into the advance-side hydraulic chamber 69 and the retard-side hydraulic chamber 70 at the time of starting the engine, the vane rotor 241 moves relative to the shoe housing 243 as shown in FIG. It is at the most retarded position shown. At this time, as shown in FIG. 7, the magnet 31 causes the vane rotor 2
41, and holds the vane rotor 241.
Therefore, the vane rotor 241 is connected to the timing gear 224.
a.

After the engine is started, oil is supplied from the oil pump 52 to each of the retard side hydraulic chambers 70 and the vane rotor 2
A small amount of oil flows into a contact portion between the first gear 41 and the timing gear 224a. Then, the vane rotor 241 and the magnet 3
The oil flows into the minute gap between the vane rotor 241 and the magnet 31 formed by the surface roughness 1 to form an oil film 32 as shown in FIG. Then, the magnetic force of the magnet 31 on the vane rotor 241 is weakened by the oil film 32, and the vane rotor 241 and the timing gear 224 a
Is released. Thereby, the vane rotor 241
Becomes rotatable relative to the timing gear 224a.

Further, in order to rotate the vane rotor 241 from the most retarded position shown in FIG. 3 to the advanced side, the OCV 49 is switched to open each retarded side hydraulic chamber 70, and the oil is supplied to each advanced side hydraulic chamber 69. Supply. Also at this time, since the oil film 32 is formed between the vane rotor 241 and the magnet 31, the restraint release of the vane rotor 241 and the timing gear 224a is maintained. Then, when the hydraulic pressure in each advance-side hydraulic chamber 69 exceeds a predetermined pressure, the vane rotor 241 rotates from the most retarded position to the advanced side.

Thereafter, the EC according to the engine operating state
The OCV 49 is switched in response to an instruction from U to control the hydraulic pressure in each of the advance-side hydraulic chamber 69 and each of the retard-side hydraulic chambers 70, so that the rotational phase difference of the vane rotor 241 with respect to the timing gear 224a, that is, the intake camshaft 22 Is controlled. Thereby, the valve timing of the intake valve 20 can be controlled with high accuracy.

As described above, in the valve timing adjusting device for an internal combustion engine according to the second embodiment, when the hydraulic pressure is not acting on the advance hydraulic chamber 69 and the retard hydraulic chamber 70, the timing gear 224a The timing gear 224a and the vane rotor 24
The relative rotation with respect to 1 is restrained. When hydraulic pressure acts on the advance hydraulic chamber 69 and the retard hydraulic chamber 70, the hydraulic pressure causes the magnet 31, the timing gear 224a, and the vane rotor 241 to operate.
An oil film 32 is formed between them, and the restriction of the relative rotation is released. Therefore, the relative rotation between the timing gear 224a and the vane rotor 241 is restricted by the magnetic force of the magnet 31, and the advance hydraulic chamber 69 and the retard hydraulic chamber 70 for relatively rotating the timing gear 224a and the vane rotor 241 are formed. The pressure is used to release the constraint on the relative rotation between the timing gear 224a and the vane rotor 241.
There is no need to separately provide a hydraulic chamber or an oil passage only for restraining the rotation of the timing gear 224a and the vane rotor 241 at a predetermined restraint position. Accordingly, the relative rotation between the timing gear 224a and the vane rotor 241 can be restrained and the restraint can be switched with a simple structure, and the cost can be reduced.

Further, the vane rotor 241 is restrained by the magnetic force of the magnet 31 provided on the timing gear 224a,
Since there is no means for restraining the vane rotor 241 unlike the prior art, the mass of each vane 68 of the vane rotor 241 can be made uniform, and the rotational balance of the vane rotor 241 can be stabilized. Further, since the oil passage for operating the restraining means as in the prior art is not provided in the vane rotor 241, the advance hydraulic chamber 6 is not provided.
9 and the retard side hydraulic chamber 70 can be improved in sealing performance.

Next, a third embodiment will be described. FIG. 9 is an enlarged view showing a specific configuration of a valve timing adjusting device for an internal combustion engine according to the third embodiment. The same components as those in the first and second embodiments are denoted by the same reference numerals. In the figure, the journal 22a of the intake camshaft 22 provided with the valve timing adjusting mechanism 324 is rotatably supported by the bearing portion 14a of the cylinder head 14. The tip of the intake camshaft 22 passes through the center of the timing gear 324a. The timing gear 324a is rotatable with respect to the intake camshaft 22. A vane rotor 341 is fixed to a tip end surface of the intake camshaft 22 with bolts 342, and the vane rotor 341 is connected to the intake camshaft 2.
It rotates integrally with the intake camshaft 22 about the second axis L. The vane rotor 341 is made of a magnetic material such as iron.

On the other hand, a shoe housing 343 provided so as to cover the vane rotor 341 is in contact with the tip end surface of the timing gear 324a. The shoe housing 343 includes a ring cover 344 provided so as to surround the outer periphery of the vane rotor 341, and a closing plate 345 provided so as to close the opening at the distal end of the ring cover 344. Further, on the vane rotor 341 side of the timing gear 324a, facing the vane rotor 341,
A concave portion 24c of a space formed with a convex cross section is formed, and a magnet 33 which is a permanent magnet formed with a convex cross section is fitted into the concave portion 24c via a spring 34. The spring 33 urges the magnet 33 in the direction of the vane rotor 341. The timing gear 324a, the ring cover 344, and the closing plate 345 are
The intake camshafts 22 are connected by bolts 346 so that they can rotate integrally about the axis L of the intake camshafts 22. The magnet 33 and the spring 34 can restrict the relative rotation between the vane rotor 341 and the timing gear 324a.

Next, the operation of the variable valve timing mechanism 324 according to the third embodiment will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 10 is an enlarged view of the portion E in FIG. 9 when it is restrained. FIG. 11 is an enlarged view of the portion E in FIG. 9 when the restraint is released. In addition, A- in FIG.
Since the A sectional view has the same configuration as that of FIG. 3, FIG. 3 is substituted. When oil is not introduced from the oil pump 52 into the advance hydraulic chamber 69 and the retard hydraulic chamber 70 at the start of the engine, the vane rotor 341 moves relative to the shoe housing 343 as shown in FIG. It is at the most retarded position shown. At this time, the magnet 33
10, is biased toward the vane rotor 341 by the spring 34, and is attracted to the vane rotor 341 by the magnetic force of the magnet 33 to hold the vane rotor 341. Therefore, the vane rotor 341
Are restrained by the timing gear 324a.

After the engine is started, oil is supplied from the oil pump 52 to each of the retard side hydraulic chambers 70, and the vane rotor 3
A small amount of oil flows into a contact portion between the first gear 41 and the timing gear 324a. Then, the vane rotor 341 and the magnet 3
Oil flows into the minute gap between the vane rotor 341 and the magnet 33 formed by the surface roughness of FIG.
The oil film 35 is formed as shown in FIG. Further, hydraulic pressure acts between the vane rotor 341 and the magnet 33. And
The oil film 35 weakens the magnetic force of the magnet 33 on the vane rotor 341. Further, the vane rotor 341 and the magnet 3
When the oil pressure during the period 3 exceeds a predetermined pressure, the magnet 33 moves in a direction away from the vane rotor 341 against the urging force of the spring 34, and the constraint between the vane rotor 341 and the timing gear 324a is released. This allows the vane rotor 341 to rotate relative to the timing gear 324a.

Further, in order to rotate the vane rotor 341 from the most retarded position shown in FIG. 3 to the advanced side, the OCV 49 is switched to open each retarded side hydraulic chamber 70, and the oil is supplied to each advanced side hydraulic chamber 69. Supply. Also at this time, since hydraulic pressure acts between the vane rotor 341 and the magnet 33, the release of the constraint between the vane rotor 341 and the timing gear 324a is maintained. When the hydraulic pressure in each advance-side hydraulic chamber 69 becomes equal to or higher than a predetermined pressure, the vane rotor 341 rotates from the most retarded position to the advanced side.

Thereafter, the EC according to the engine operating state
The OCV 49 is switched in response to an instruction from U to control the hydraulic pressure in each of the advance side hydraulic chamber 69 and each of the retard side hydraulic chambers 70, and the rotational phase difference of the vane rotor 341 with respect to the timing gear 324a, that is, the intake camshaft 22 with respect to the crankshaft 15 Is controlled. Thereby, the valve timing of the intake valve 20 can be controlled with high accuracy.

As described above, in the valve timing adjusting device for an internal combustion engine according to the third embodiment, the magnet 33 is biased by the spring 34 and the hydraulic pressure is reduced.
, A clearance c is formed between the vane rotor 341 and the magnet 33, and the magnetic force of the magnet does not hinder the rotation of the vane rotor 341. Thus, the responsiveness of the valve timing is improved.

Further, the vane rotor 341 is restrained by the magnetic force of the magnet 31 provided on the timing gear 324a,
Since there is no means for restraining the vane rotor 341 as in the prior art, the mass of each vane 68 of the vane rotor 341 can be made uniform, and the rotational balance of the vane rotor 341 can be stabilized. Further, since the oil passage for operating the restraining means as in the prior art is not provided in the vane rotor 341, the advance-side hydraulic chamber 6 is not provided.
9 and the retard side hydraulic chamber 70 can be improved in sealing performance.

The present invention is not limited to the above embodiment. In the above embodiment, the rotation of the crankshaft 15 is controlled by the timing gear 24a via the timing chain to the intake camshaft 22 and the exhaust camshaft 23. , But a timing pulley may be used.

In the above embodiment, the valve timing adjusting device for the internal combustion engine that drives the intake valve 20 to open and close has been described. However, only the exhaust valve 21 or both the intake valve 20 and the exhaust valve 21 are driven to open and close. It may be used for a valve timing adjusting device of an internal combustion engine.

In the above embodiment, the variable valve timing mechanism 24 having four vanes 68 has been described. However, the variable valve timing mechanism 24 having a number of vanes 68 other than four may be used.

In the second and third embodiments, the magnets 31 and 33 are provided on the timing gears 224a and 324a. However, the closing plates 245 and 345, and the vane rotor 241 are provided. And the vane rotor 341.

[0058]

As described above, according to the first aspect of the present invention, when the hydraulic pressure is not acting on the first pressure chamber and the second pressure chamber, the cover is rotated by the elastic body for the second rotation. The relative rotation between the first rotating body and the second rotating body is restrained by the frictional force generated between the cover and the second rotating body when biased by the body. When hydraulic pressure acts on the first pressure chamber and the second pressure chamber, the cover moves against the urging force of the elastic body due to the hydraulic pressure, and releases the restriction of the relative rotation. Thus, claim 1
According to the invention described in (1), the first pressure chamber for restraining the relative rotation of the first rotator and the second rotator by the biasing force of the elastic body and relatively rotating the first rotator and the second rotator. And the restriction of the relative rotation between the first rotating body and the second rotating body is released by using the pressure of the second pressure chamber. There is no need to separately provide a hydraulic chamber or an oil passage only for restraining at the restraining position. Thus, the relative rotation between the first rotating body and the second rotating body can be restrained and switched from being released with a simple structure, and the number of processing steps does not increase, and the cost can be reduced.

According to the second aspect of the present invention, when no hydraulic pressure acts on the first pressure chamber and the second pressure chamber, the relative force between the first rotating body and the second rotating body is determined by the magnetic force of the magnet. Restrict rotation. When a hydraulic pressure acts on the first pressure chamber and the second pressure chamber, an oil film is formed between the magnet and the first rotating body or the second rotating body by the hydraulic pressure, and the restriction of the relative rotation is released.
Thus, in the invention according to claim 2, the relative rotation between the first rotating body and the second rotating body is restrained by the magnetic force of the magnet,
A first rotating member for relatively rotating the first rotating member and the second rotating member;
Since the restraint on the relative rotation between the first rotating body and the second rotating body is released by using the fluid in the pressure chamber and the second pressure chamber, the rotation between the first rotating body and the second rotating body is prevented. It is not necessary to separately provide a hydraulic chamber or an oil passage only for restraining at a predetermined restraining position.
Thus, the relative rotation of the first rotating body and the second rotating body can be restrained and released by a simple structure, so that the number of processing steps does not increase and the cost can be reduced.

According to the third aspect of the present invention, when no hydraulic pressure acts on the first pressure chamber and the second pressure chamber, the first rotating body and the second rotating body are magnetized by the elastic body. Restrict the relative rotation of the rotating body. When a hydraulic pressure acts on the first pressure chamber and the second pressure chamber, a pressure acts on the magnet due to the hydraulic pressure, and the magnet moves against the urging force of the elastic body to release the restriction of the relative rotation. Thus, in the invention of claim 3,
When pressure acts on the magnet, the magnet separates from the first rotating body or the second rotating body against the urging force of the elastic body, so that the magnet is hardly affected by the contact state of the second rotating body when releasing the constraint. Thus, the responsiveness is improved, and the valve timing can be controlled accurately.

[0061]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an internal combustion engine to which a valve timing device for an internal combustion engine according to an embodiment is applied.

FIG. 2 is an enlarged view showing a specific configuration of a valve timing adjustment device for an internal combustion engine according to the first embodiment.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is an enlarged view of a portion C in FIG. 2 when it is restrained.

FIG. 5 is an enlarged view of a part C in FIG. 2 when restraint is released.

FIG. 6 is an enlarged view showing a specific configuration of a valve timing adjustment device for an internal combustion engine according to a second embodiment.

FIG. 7 is an enlarged view of a portion D in FIG. 6 when it is restrained.

FIG. 8 is an enlarged view of a portion D in FIG. 6 when restraint is released.

FIG. 9 is an enlarged view showing a specific configuration of a valve timing adjustment device for an internal combustion engine according to a third embodiment.

FIG. 10 is an enlarged view of a portion E in FIG. 9 when it is restrained.

FIG. 11 is an enlarged view of a portion E in FIG. 9 when restraint is released.

[Explanation of symbols]

11 ... Engine, 12 ... Piston, 13 ... Cylinder block, 13a ... Oil pan, 14 ... Cylinder head, 1
4a: Bearing, 15: Crankshaft, 16: Connecting rod, 17: Combustion chamber, 18: Intake port, 19: Exhaust port, 20: Intake valve, 21: Exhaust valve, 22: Intake camshaft, 22a: Journal, 23 ... Exhaust cam shaft, 24, 224, 324 ... Valve timing variable mechanism, 24a, 224a, 324a ... Timing gear, 24b ... Concave part, 24c ... Concave part, 25 ... Timing gear, 26 ... Timing chain, 27 ... Intake cam, 28
... Exhaust cam, 31 ... Magnet, 32 ... Oil film, 33 ... Magnet, 3
4 ... Spring, 35 ... Oil film, 41, 241, 341 ...
Vane rotor, 41a ... extension part, 42, 242, 342
... bolts, 43, 243, 343 ... shoe housings
44, 244, 344: ring cover, 45, 245,
345: closing plate, 45a: seal, 46, 246, 34
6 bolt, 46a spring, 47 advance angle control oil passage, 47a head oil passage, 47b oil groove, 47c oil hole, 47d shaft oil passage, 47e oil hole, 47f annular space, 47g ... Oil hole, 48 ... retard angle control oil passage, 48a ...
Head oil passage, 48b oil groove, 48c oil hole, 48d shaft oil passage, 48e oil hole, 48f annular space, 48g
... Oil hole, 49 ... OCV, 50 ... Supply passage, 51 ... Discharge passage, 52 ... Oil pump, 56 ... Casing, 57 ... First supply / discharge port, 58 ... Second supply / discharge port, 59 ... Discharge port, 60 ... Discharge port, 62 ... Coil spring, 63
... Spool, 65 ... Electromagnetic solenoid, 66 ... Shoe, 6
7: fan-shaped space portion, 68: vane, 69: advanced hydraulic chamber,
70: retard-side hydraulic chamber, 71: sealing member, 72: leaf spring

Claims (3)

[Claims] A first rotating body having at least one concave portion on an inner peripheral surface; and at least one vane dividing the concave portion into a first pressure chamber and a second pressure chamber. A second rotator combined to be relatively rotatable, a cover covering a side surface of the first rotator, and a drive for synchronously rotating one of the first rotator or the second rotator at a reference rotation phase of the internal combustion engine. A shaft, a driven shaft interlocked with the other of the first rotating body or the second rotating body, and the first rotating body and the second rotating body formed by pressure applied to the first pressure chamber and the second pressure chamber. In a valve timing adjusting device for an internal combustion engine, comprising: a relative rotating means for relatively rotating a rotating body, wherein the cover is urged by the second rotating body by an elastic body, and the cover and the second rotating body Due to the frictional force The first rotating body and the second rotating body are restrained, and the cover is moved against the urging force of the elastic body by the pressure applied to the first pressure chamber and the second pressure chamber, and the first cover is moved. A valve timing adjusting device for an internal combustion engine, which releases a constraint between a rotating body and a second rotating body. 2. A first rotating body having at least one concave portion on an inner peripheral surface, and at least one vane dividing the concave portion into a first pressure chamber and a second pressure chamber, wherein the first rotating body has A second rotating body combined to be relatively rotatable, a drive shaft for synchronously rotating one of the first rotating body or the second rotating body at a reference rotation phase of the internal combustion engine, and the first rotating body or the second rotating body. A driven shaft interlocked with the other of the rotating bodies, and relative rotating means for relatively rotating the first rotating body and the second rotating body by pressure applied to the first pressure chamber and the second pressure chamber; And a valve timing adjusting device for an internal combustion engine including a magnet for restricting relative rotation between the first rotating body and the second rotating body. 3. The internal combustion engine according to claim 2, wherein the magnet is provided on one of a first rotating body and a second rotating body, and the magnet is urged to the other by an elastic body. Valve timing adjustment device.