JP2002276310A - Valve timing control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sensitively control rotational phase of a camshaft over all of speed areas of an internal combustion engine to enhance response and stability of phase control. SOLUTION: A phase changeable apparatus 8 is disposed between a driving sprocket 1 and a camshaft 2, and is constituted of a planetary gear mechanism 9 of a type of acceleration in the same direction, a lock release lever 14, spring clutches 15, 17, a release ring 18, a clutch release coils 22, 23 and brake control coils 24, 25. Control force exerted on a brake drum 13 by the brake control coil 24 and control force exerted on a rotating drum 3 by the brake control coil 25 are individually changed according to increase/decrease in engine speed. Since each control force suppresses effect of load torque acting on the camshaft 2, the rotational phase of the camshaft 2 can be stably and changeably controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing control apparatus for an internal combustion engine which is preferably used for variably controlling the opening / closing timing of an intake valve, an exhaust valve and the like of an automobile engine in accordance with an operation state.

[0002]

2. Description of the Related Art Generally, in an internal combustion engine such as an automobile engine, the opening and closing timing of an intake valve, an exhaust valve and the like is appropriately changed in accordance with the operating state of the engine to improve the engine performance. There has been proposed a device equipped with a valve timing control device that variably changes the rotation phase between a crankshaft and a camshaft (for example, Japanese Patent Application Laid-Open No. 9-250309).

[0003] A valve timing control device according to this type of prior art is configured to rotate according to the rotation of a rotating body driven by a crankshaft of an internal combustion engine and to open and close an intake valve or an exhaust valve of the internal combustion engine. And a rotating phase variable means provided between the camshaft and the rotating body for variably controlling the rotating phase of the camshaft with respect to the rotating body.

Here, the rotation phase changing means includes a planetary gear mechanism comprising a sun gear, a planetary gear, and an internal gear provided between the rotating body and the camshaft, and a sunshaft of the planetary gear mechanism is connected to the camshaft. An electromagnetic clutch to be fastened or released to the side, a braking force is applied to the sun gear when the electromagnetic clutch is released, and a relative rotation is generated between the internal gear and the sun gear to cause the planetary gear to rotate. It is composed of an electromagnetic brake that rotates.

In this case, when the rotational phase of the camshaft with respect to the rotating body is maintained, the electromagnetic clutch is engaged by using a leaf spring such as a wave ring, and the sun gear of the planetary gear mechanism is connected to the camshaft. The rotation phase between the rotating body and the camshaft is kept constant by being fixed so as not to rotate.

When changing the rotation phase of the camshaft with respect to the rotating body, the electromagnetic clutch and the electromagnetic brake are energized to release the engaged state of the electromagnetic clutch, and in this state, the electromagnetic brake is applied to the sun gear. By applying a braking force and rotating the internal gear and the sun gear relative to each other to rotate the planetary gear, the rotation phase of the rotating body and the camshaft is changed to the retard side or the advance side. .

That is, as shown in FIG. 22, the exhaust valve of the internal combustion engine opens the exhaust gas in the cylinder by opening a predetermined lift amount before the crank angle of the crankshaft reaches the exhaust top dead center. Discharge to the outside. Also,
The intake valve opens in a similar manner after the crank angle passes through the exhaust top dead center, thereby sucking intake air into the cylinder.

When the rotational phase of the camshaft is controlled to advance in the advance direction with respect to the rotator, the opening timing of the exhaust valve and the intake valve is advanced and the rotational phase of the camshaft is controlled as shown in FIG. Is controlled in the retard direction to delay the opening timing of the exhaust valve and the intake valve.

In this case, the intake valve and the exhaust valve are constantly urged in the valve closing direction by the coil spring, and are opened against the urging force of the coil spring when the valve is opened. A load torque acts as a rotation torque according to the closing of the valve, and this load torque fluctuates with respect to the rotation angle of the camshaft as shown by a characteristic curve S1 in FIG.

[0010]

In the above-described prior art valve timing control apparatus, when changing the rotation phase of the camshaft with respect to the rotating body, the influence of the load torque on the camshaft in a low engine speed range. And the effect of the load torque on the camshaft is reduced in the high rotation speed range.

That is, in the entire operation range of the internal combustion engine, the load torque (alternating torque) on the retard side and the advance side added to the camshaft from the valve side is represented by a characteristic line S1 shown in FIG.
When the engine speed is low, the torque value is large.

However, when the engine speed increases from a low speed to a high speed, for example, 3000 to 4000
In a rotational speed range of about rpm, the amplitude is large as indicated by a characteristic line S2 shown in FIG. 23, but the frequency is high, so that the phase converter becomes an inertial damper and the torque is equivalently reduced.

For this reason, when the rotational phase of the camshaft is finely controlled, if the braking force of the electromagnetic brake is set based on the low rotational speed range of the engine, the responsiveness of the phase control is reduced in the high rotational speed range. Conversely, if the braking force of the electromagnetic brake is set based on the high rotation speed range, the control response will be excessively fast in the low rotation speed range, making it difficult to control by finely changing the phase angle of the rotation phase. There's a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to enable fine control of the rotational phase of a camshaft over the entire rotational speed range of an internal combustion engine. It is an object of the present invention to provide a valve timing control device for an internal combustion engine, which can improve the responsiveness and stability of the engine.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention opens and closes a rotating body driven by a crankshaft of an internal combustion engine and an intake valve or an exhaust valve of the internal combustion engine. Therefore, an internal combustion engine including a camshaft that is rotated according to the rotation of the rotating body, and rotation phase variable means provided between the camshaft and the rotating body for variably controlling the rotation phase of the camshaft with respect to the rotating body. This is applied to the valve timing control device.

A feature of the construction adopted in the first aspect of the present invention is that the rotation phase variable means electrically controls the rotation phase of the camshaft with respect to the rotating body by applying a braking force using an electromagnetic brake. And a phase changing mechanism configured to variably control the braking force of the electromagnetic brake according to the rotation speed of the internal combustion engine.

With this configuration, the braking force of the electromagnetic brake can be varied according to the engine speed even if the influence of the load torque accompanying opening and closing of the intake valve or exhaust valve affects the camshaft. In this case, the responsiveness of the phase control is increased in the high rotation speed range, and quick control is possible.
In the low rotation speed range, the response of the phase control can be prevented from becoming too fast, and control can be performed so as to finely change the phase angle of the rotation phase. In addition, the variable control of the rotation phase by the phase changing mechanism can be performed by electrical control, so that maintenance and inspection work can be facilitated as compared with, for example, control by hydraulic pressure, and the occurrence of problems due to air mixing and the like can be prevented. Can be eliminated.

According to the second aspect of the present invention, the electromagnetic brake is configured to gradually increase the braking force as the rotational speed of the internal combustion engine increases. As a result, the load torque applied to the camshaft from the valve side decreases as the engine speed increases. For example, even if a torque shortage occurs when performing a phase change, an electromagnetic brake is provided so as to compensate for this. Can be increased, and the rotation phase of the camshaft can be stabilized and changed.

According to the third aspect of the present invention, the electromagnetic brake reduces the braking force gradually until the rotation speed of the internal combustion engine reaches a predetermined rotation speed from the idling rotation speed, and the braking force becomes smaller than the predetermined rotation speed. The braking force is gradually increased as the rotation speed becomes higher.

In this case, when the engine speed is the idling speed, a large load torque acts on the camshaft, and the response of the phase control tends to be excessively fast.
This can be suppressed by the braking force of the electromagnetic brake,
Control can be performed to finely change the phase angle of the rotation phase.
While the engine speed increases from the idling speed to a predetermined speed, the responsiveness of the phase control can be maintained at an appropriate speed by gradually decreasing the braking force. On the other hand, when the engine speed further increases from the predetermined speed, the influence of the load torque becomes smaller, and accordingly, the responsiveness of the phase control can be improved by gradually increasing the braking force in accordance with the load torque. Control can be performed.

According to the fourth aspect of the present invention, the rotation phase changing means includes a phase changing mechanism and a phase shift mechanism for restricting the relative rotation of the cam shaft with respect to the rotating body on the advance side and allowing the relative rotation in the opposite direction. A one-way clutch, a one-way clutch on a retard side that restricts relative rotation of the camshaft with respect to the rotating body on the retard side and allows relative rotation in the opposite direction,
The phase change mechanism releases the one-way clutch on the advance side by the clutch release mechanism, which comprises an advance side and a retard side clutch release mechanism for individually releasing the rotation restraint by the one-way clutch on the retard side. sometimes,
By operating the electromagnetic brake, the rotation phase of the camshaft with respect to the rotating body is changed in the advance direction.

Thus, while the engine speed is in a relatively low speed range, for example, if the one-way clutch on the advance side is released by the clutch release mechanism on the advance side, the load torque on the camshaft side is utilized. The rotation phase of the camshaft with respect to the rotating body can be variably controlled in the advance direction. Further, when the one-way clutch on the retard side is released by the clutch release mechanism on the retard side, the rotational phase of the camshaft with respect to the rotating body can be variably controlled in the retard direction using the load torque on the camshaft side. it can.

When the rotational speed of the internal combustion engine is in a relatively high rotational speed range, the one-way clutch on the advance side is disengaged by the clutch disengaging mechanism, and the camshaft for the rotating body is operated by operating the phase changing mechanism. Can be variably controlled in the advance direction, and the insufficient torque of the load torque can be compensated for by the phase changing mechanism. Further, when the one-way clutch on the retard side is released in this state, the camshaft can relatively rotate in the retard direction with respect to the rotating body, and the variable control of the rotational phase in the retard direction can be performed.

According to the fifth aspect of the present invention, the phase changing mechanism transmits the rotational force between the rotating body and the camshaft so as to increase the speed of the camshaft relative to the rotating body in the same direction. It comprises a directional speed-increasing planetary gear mechanism and an electromagnetic brake for electrically controlling the operation of the planetary gear mechanism.

Thus, when the braking force is applied by the electromagnetic brake, the planetary gear mechanism operates to increase the speed of the camshaft in the same direction with respect to the rotating body, and the rotational phase of the camshaft is made higher than that of the rotating body. You can proceed. Further, when the braking force by the electromagnetic brake is released, the rotation of the planetary gear is restricted, and the operation as the phase changing mechanism can be kept stopped.

According to a sixth aspect of the present invention, the planetary gear mechanism includes a first rotating member integrally provided on the rotating body and rotatably supporting the planetary gear, and the planetary gear integrally provided on the camshaft side. A second rotating member provided with an internal gear meshing with the gear, and a third rotating member provided with a sun gear provided rotatably with respect to the rotating body and the camshaft to mesh with the planetary gear; The one-way clutch on the advance side is provided between one of the first and third rotating members and the second rotating member, and the one-way clutch on the retarding side is the first and third rotating members. The electromagnetic brake is provided between the other one of the third rotating members and the second rotating member, and the electromagnetic brake is configured to apply a braking force to the third rotating member.

Thus, when the electromagnetic brake applies a braking force to the third rotating member, a relative rotation (rotational difference) is generated between the first rotating member and the third rotating member. The second rotating member is rotated in the same direction as the first rotating member and rotates at a higher speed than the first rotating member, so that the rotation phase of the camshaft can be advanced more than the rotating body. Further, when the braking force by the electromagnetic brake is released, the third rotating member rotates substantially integrally with the first rotating member, so that the planetary gears only revolve according to the first rotating member without rotating, and 1
The rotational force (revolution force) from the rotating member can be transmitted to the second rotating member via the internal gear.

According to the seventh aspect of the present invention, the electromagnetic brake also functions as a part of the advance-side clutch release mechanism, and uses a single electromagnetic coil to release the advance-side one-way clutch and establish the third-way clutch. And a braking force is applied to the rotating member.

Thus, the advance-side clutch release mechanism and the electromagnetic brake can be configured using a single (common) electromagnetic coil, and the release operation on the advance-side one-way clutch and the braking force on the third rotating member can be performed. Can be performed in combination with the application operation.

According to the eighth aspect of the present invention, the phase change mechanism applies a braking force to the camshaft when the one-way clutch on the retard side is released by the clutch release mechanism, thereby providing a camshaft to the rotating body. And an electromagnetic brake for retard control that changes the rotation phase of the motor in the retard direction.

Thus, when the rotational phase of the camshaft with respect to the rotating body is changed in the retard direction, the one-way clutch on the retard side is released by the clutch release mechanism, and the rotating body and the camshaft are retarded. Since relative rotation becomes possible, the electromagnetic brake for retard control is actuated in this state to apply a braking force to the camshaft side, so that the rotation of the camshaft is decelerated and the retard control is reliably performed. Can be.

Further, according to the ninth aspect of the present invention, the electromagnetic brake for retard control gradually increases the braking force as the rotational speed of the internal combustion engine increases when the rotational phase is changed to the retard direction. When the rotational phase of the shaft is changed in the advance direction, the braking force is gradually reduced as the rotational speed of the internal combustion engine increases.

Thus, the load torque applied to the camshaft from the valve side decreases as the engine speed increases. For example, even if a torque shortage occurs when the phase is changed in the retard direction, The electromagnetic brake for retard control can increase the braking force so as to compensate for the insufficient torque, and can change the rotational phase of the camshaft stably in the retard direction.

When the phase is changed in the advance direction, a large load torque acts on the camshaft when the engine speed is low, and the response of the phase control tends to be excessively fast. By applying a braking force to the camshaft using the electromagnetic brake for angle control, the rotation of the camshaft is decelerated so that the advance of the rotational phase can be suppressed.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a valve timing control apparatus for an internal combustion engine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking an example in which the present invention is applied to an automobile engine.

FIGS. 1 to 14 show the first embodiment of the present invention.
Is shown. In the figure, reference numeral 1 denotes a driving sprocket as a rotating body. The driving sprocket 1 is connected to a crankshaft of an engine via a chain (neither is shown) or the like, and rotational force from the crankshaft is transmitted.

The driving sprocket 1 is integrally connected to a carrier 10 and a cover 11, which will be described later, using bolts or the like, and rotates around the camshaft 2 in a clockwise direction (for example, a direction indicated by an arrow A in FIG. 5). Is driven to rotate.

Reference numeral 2 denotes a camshaft which is disposed so as to be rotatable relative to the driving sprocket 1. The camshaft 2 is rotatably provided on the cylinder head (not shown) side of the engine. In the same direction (the direction indicated by the arrow A in FIG. 5).

The camshaft 2 is configured to open or close one of an intake valve and an exhaust valve (not shown) of the engine. Also,
The camshaft 2 is provided with a rotating drum 3 and a stepped cylindrical body 5 which will be described later, and rotates integrally therewith.

Reference numeral 3 denotes a rotary drum which constitutes a part of the camshaft 2. The rotary drum 3 is fastened to the end of the camshaft 2 together with a stepped cylinder 5 using a connecting bolt 4. They rotate together. The rotating drum 3 is connected to a drum portion 13 of a brake drum 13 described later.
C is formed with substantially the same outer diameter as that of C, and relative rotation with respect to the drum portion 13C is restrained or released by a spring clutch 17 described later.

Reference numeral 5 denotes a stepped cylinder integrally provided between the camshaft 2 and the rotary drum 3 using the connecting bolt 4.
One end of the stepped cylindrical body 5 that abuts against the rotating drum 3 is a small-diameter cylindrical portion 5A, and the other end that is fitted to the end of the camshaft 2 is a large-diameter flange portion 5B. The stepped cylinder 5 constitutes a second rotating member of a planetary gear mechanism 9 described later, and a short cylindrical internal gear 5C is integrally provided on the outer peripheral side of the flange 5B.

The stepped cylinder 5 has a small-diameter cylinder portion 5A and a flange portion 5A.
A portion between B and B is an intermediate cylindrical portion 5D, and an inner peripheral side of a carrier 10 described later is rotatably fitted on the outer peripheral side of the intermediate cylindrical portion 5D. Further, a ring drum 6, which will be described later, is fixed to the outer peripheral side of the intermediate cylindrical portion 5D by means such as press-fitting, so that the carrier 10 is held in a state of being prevented from being removed from the intermediate cylindrical portion 5D.

Reference numeral 6 denotes a ring drum which constitutes a second rotating member on the camshaft 2 side together with the stepped cylindrical body 5. The ring drum 6 is located between an unlock lever 14 and a carrier 10 described later. It is fixed to the outer peripheral side of the intermediate cylindrical portion 5D of the attached cylindrical body 5 in a detented state. The ring drum 6 is formed to have substantially the same outer diameter as a later-described drum portion 10D, and the relative rotation of the ring drum 6 with respect to the drum portion 10D is restrained or released by a later-described spring clutch 15.

Reference numeral 7 denotes a fixing pin provided between the camshaft 2 and the stepped cylinder 5, and the fixing pin 7 fixes the stepped cylinder 5 to the end of the camshaft 2, and integrally fixes the two. It constitutes a connector for rotation.

8 is a driving sprocket 1 and a camshaft 2
And a phase variable device serving as a rotation phase variable means provided between the phase change device 8 and the phase variable device 8.
Lock release lever 14, Spring clutch 15, 1
7, a release ring 18, clutch release coils 22 and 23, brake control coils 24 and 25, and the like.

Reference numeral 9 denotes a planetary gear mechanism which constitutes a part of a phase changing mechanism for changing the rotation phase of the camshaft 2 with respect to the driving sprocket 1 by electrical control.
Is composed of a carrier 10, a planetary gear 12, a brake drum 13, and an internal gear 5C of the stepped cylinder 5, which will be described later. This constitutes a speed type planetary gear mechanism.

Reference numeral 10 denotes a carrier serving as a first rotating member of the planetary gear mechanism 9. The carrier 10 is integrated with the driving sprocket 1 using bolts or the like. As shown in FIGS. 3 to 5, the carrier 10 is formed with gear insertion holes 10A, 10A that are separated upward and downward to rotatably support a planetary gear 12 described later.

As shown in FIG. 4, a boss 10B projecting in the axial direction into a stepped cylindrical shape is integrally formed on the inner peripheral side of the carrier 10, and the inner peripheral side of the boss 10B is described later. A large-diameter storage hole 10C in which the sleeve 16 and the like are rotatably stored, and a drum portion 10D formed to have a smaller diameter than the storage hole 10C and protruding in the axial direction toward the storage hole 10C are provided. I have.

The carrier 10 is provided so that the driving sprocket 1 is rotatably mounted around the camshaft 2.
D is rotatably inserted. The drum unit 10
A spring clutch 15 to be described later is wound around the outer peripheral side of D and the ring drum 6, and a locking hole 10E for locking one end of the spring clutch 15 is formed in the boss 10B as shown in FIG. It is drilled in the direction.

As shown in FIG. 3, the boss portion 10B of the carrier 10 extends substantially in the shape of a rhombus in the radial direction, and has a gear insertion hole at an end portion extending toward each gear insertion hole 10A. 10
A pin hole 10F is formed on the same axis as A. The pin hole 10F is provided in the gear insertion hole 1.
The planetary gear 12 is rotatably supported together with 0A.

Further, bolt holes 10G are provided on the outer peripheral side of the carrier 10 at intervals in the circumferential direction, and the bolts inserted into these bolt holes 10G allow the carrier 10 to be connected to the driving sprocket 1 and a cover 11 described later. They are integrally fixed.

Reference numeral 11 denotes a stepped annular cover connected to the drive sprocket 1 together with the carrier 10.
1 and 2 cover the flange 5B and the internal gear 5C of the stepped cylinder 5 from the outside as shown in FIGS. 1 and 2, and protect the tooth surface of the internal gear 5C from external dust and obstacles. And cover 1
Reference numeral 1 denotes a unit that rotates integrally with the drive sprocket 1 together with the carrier 10.

Reference numerals 12 and 12 denote, for example, two planetary gears which are rotatably inserted into the respective gear insertion holes 10A of the carrier 10. Each of the planetary gears 12 has a large diameter gear portion as shown in FIG. 12A, a small-diameter gear portion 12B, and a pin shaft portion 12C axially protruding from one end of the small-diameter gear portion 12B.

Here, the planetary gear 12 is a small-diameter gear 12
B is inserted into the gear insertion hole 10A of the carrier 10, and the pin shaft portion 12C is inserted into the pin hole 10F of the carrier 10, whereby smooth rotation of the planetary gear 12 with respect to the carrier 10 is compensated. Things. The small-diameter gear portion 12B of the planetary gear 12 meshes with the internal gear 5C of the stepped cylinder 5, and the large-diameter gear portion 12A meshes with a sun gear 13B described later.

Reference numeral 13 denotes a brake drum serving as a third rotating member of the planetary gear mechanism 9;
And a cylindrical sun gear 13B protruding from the inner peripheral side of the disk portion 13A toward one side in the axial direction and meshing with the large-diameter gear portion 12A of the planetary gear 12, as shown in FIG. And a drum portion 13 </ b> C protruding from the inner peripheral side of the disk portion 13 </ b> A toward the other side in the axial direction and having an outer diameter substantially corresponding to the rotating drum 3.

As shown in FIG. 2, the inner peripheral side of the disk portion 13A and the sun gear 13B is inserted into the outer peripheral side of the small-diameter cylindrical portion 5A via a sliding cylinder 14A described later. The relative rotation can be smoothly performed around the portion 5A. The sun gear 13 </ b> B of the brake drum 13 meshes with the planetary gear 12, and the rotational force from the carrier 10 is transmitted via the planetary gear 12.

Here, when the braking force of the brake drum 13 is released as described later, the rotational force from the carrier 10 is transmitted through the planetary gears 12 so that the rotational speed of the brake drum 13 is substantially the same as that of the carrier 10 in the same direction ( (In the direction of arrow A in FIG. 5). At this time, the planetary gear 12 transmits its orbital force to the sun gear 13B without rotating (rotating) relative to the carrier 10.

On the other hand, when the brake drum 13 rotates relative to the stepped cylinder 5 in the direction indicated by the arrow B in FIG. 5 in accordance with the braking force fb to be described later, the sun gear 13B and the planetary gear 1 rotate.
2, the rotation reaction force in the direction of arrow C is transmitted, and the planetary gear 12 rotates relative to the carrier 10 (rotates in the direction of arrow C in FIG. 5).

As a result, the camshaft 2 is connected to the planetary gear 1
The rotation in the advance direction, which advances the rotation phase, is transmitted from 2 to the internal gear 5C of the stepped cylinder 5, and the speed of the drive sprocket 1 is increased several times in the same direction (the direction of arrow A in FIG. 5). It is what is rotated.

Reference numeral 14 denotes the carrier 10 and the brake drum 13
The lock release lever 14 is rotatably inserted on the outer peripheral side of the small-diameter cylindrical portion 5A between the small-diameter cylindrical portion 5A and the outer peripheral side of the small-diameter cylindrical portion 5A as shown in FIGS. A sliding cylinder 14A inserted into the sliding cylinder 14A; an annular plate portion 14C radially protruding from one end of the sliding cylinder 14A and having a substantially U-shaped notch 14B formed on the outer peripheral side; 14C is bent in a substantially L-shape from the outer peripheral side of the sliding cylinder 14A in the radial direction (left,
(Right direction).

As shown in FIG. 2, the lock release lever 14 extends to a position where the lever portion 14D faces the clutch release coil 22 described later in the axial direction, and a braking force is applied from the clutch release coil 22. , Relative to the carrier 10 (in the direction of arrow B in FIG. 5). At this time, the lock release lever 14 applies a restraint release force in the direction of arrow B to the spring clutch 15 to forcibly release the rotation restraint in the advance angle direction by the spring clutch 15.

The lock release lever 14 is connected to the carrier 1
0 is connected via a spring (not shown) or the like, and the rotational force from the carrier 10 is transmitted in the direction of arrow A in FIG. I do. However, when a braking force is applied to the lock release lever 14, the lock release lever 14 is relatively rotated with respect to the carrier 10 by the bending allowance of the spring.

Reference numeral 15 denotes a spring clutch which constitutes an advanced one-way clutch provided between the ring drum 6 on the side of the stepped cylinder 5 and the drum portion 10D of the carrier 10. The spring clutch 15 is As shown in FIG. 5, it is formed as a left-handed coil. As shown in FIG. 2, one end of the spring clutch 15 is wound around the outer periphery of the drum portion 10D, and the end of the spring clutch 15 is
A is locked in the locking hole 10E of the carrier 10.

The other end of the spring clutch 15 is wound around the outer periphery of the ring drum 6, and the other end of the spring clutch 15 serves as a hook 15B which engages with the notch 14B of the lock release lever 14 as shown in FIG. It will be stopped. In addition,
The spring clutch 15 is disclosed in, for example,
The structure is almost the same as that of the spring clutch described in Japanese Unexamined Patent Publication (Kokai) Publication.

Since the spring clutch 15 is a left-handed coil, when the carrier 10 is driven to rotate integrally with the driving sprocket 1 in the direction of arrow A (clockwise) in FIG. Camshaft 2)
If the spring clutch 15 is to be rotated relative to the carrier 10 (drive sprocket 1) in the advancing direction to increase the rotational phase even slightly, the spring clutch 15 receives a torsional torque in the direction of reducing the coil diameter.

For this reason, the spring clutch 15 operates so as to strongly wind around the outer peripheral surface of the ring drum 6, and restrains the relative rotation in the advance direction between the drum portion 10 D of the carrier 10 and the ring drum 6. When the spring clutch 15 is forcibly rotated in the direction of arrow B by the lock release lever 14, the spring clutch 15 releases the rotation restriction in the advance angle direction with respect to the ring drum 6 as described above.

On the other hand, the ring drum 6 (camshaft 2)
Is rotated relative to the carrier 10 (drive sprocket 1) in the retard direction, which slows down the rotational phase, the torsion torque in the direction in which the spring clutch 15 increases the coil diameter (the direction indicated by the arrow B in FIG. 5). As a result, the spring clutch 15 operates so as to be slightly separated from the outer peripheral surface of the ring drum 6, thereby releasing the rotation constraint between the drum portion 10D of the carrier 10 and the ring drum 6 and causing the relative rotation between them. Forgive.

Reference numeral 16 denotes a cylindrical sleeve housed in the housing hole 10C of the carrier 10 together with the spring clutch 15. The sleeve 16 holds the spring clutch 15 from the outside in the radial direction through a small gap as shown in FIG. Surrounding. The sleeve 16 is provided with the lock release lever 14.
When the spring clutch 15 is released by, for example, the spring clutch 15 has a function of restricting the spring clutch 15 from greatly expanding in the radial direction, and improving the release responsiveness and the like.

17 is a rotary drum 3 and a brake drum 13
A spring clutch constituting a one-way clutch on the retard side provided wound around the drum portion 13C.
The spring clutch 17 is formed as a right-handed coil as shown in FIG. One end of the spring clutch 17 is wound around the outer periphery of the drum 13C, and the tip of the spring clutch 17 serves as a hook 17A and protrudes radially outward. The other end of the spring clutch 17 is wound around the outer periphery of the rotary drum 3.

Since the spring clutch 17 is a right-handed coil, when the brake drum 13 is driven to rotate in the direction of arrow A (clockwise) in FIG. 6, the spring clutch 17 reduces the coil diameter. The spring clutch 17 operates to wind strongly around the driven rotary drum 3, and the rotary drum 3 relatively rotates in the retard direction with respect to the brake drum 13. Is regulated (bound).

On the other hand, the rotary drum 3 is
When rotating in the advancing direction to increase the rotation phase, the spring clutch 17 receives a torsional torque in the direction of increasing the coil diameter, whereby the spring clutch 17 is slightly separated from the outer peripheral surface of the rotating drum 3. Thus, the restrained state between the drum portion 13C of the brake drum 13 and the rotary drum 3 is released, and the relative rotation between the two is allowed.

Reference numeral 18 denotes a release ring which is inserted with a small gap around the outer periphery of the spring clutch 17. The release ring 18 is disposed axially opposite a clutch release coil 23 which will be described later, and is disposed on the inner periphery thereof. Is formed with, for example, a small U-shaped notch 18A. As shown in FIG. 6, the hook portion 17A of the spring clutch 17 is engaged with the notch 18A, and the release ring 18 rotates together with the spring clutch 17 in the arrow A direction in this state.

Here, the release ring 18 receives a braking torque in the direction of arrow B in FIG. 6 when a braking force is applied by the clutch release coil 23, and its rotation speed is the spring clutch 17 (the brake drum 13). The release ring 18 causes the notch 18A to relatively move the hook portion 17A of the spring clutch 17 in the direction of arrow B.

As a result, the hook portion 17A of the spring clutch 17 is connected to the drum portion 13C of the brake drum 13.
The operation is performed so as to be slightly separated from the outer peripheral surface, and the drum portion 13C of the brake drum 13 and the rotating drum 3 are released from the restrained state by the spring clutch 17, and both rotate relatively.

Reference numeral 19 denotes a support frame fixed to the cylinder head side of the engine.
As shown in FIG. 7, bolt holes 19A and the like are provided on the outer peripheral side, and the bolt holes 19A and the like are used to attach the engine to the cylinder head side.

Reference numeral 20 denotes a coil holder fixed in the support frame 19 using pins 21 and the like.
Are provided with clutch release coils 22 and 23 and brake control coils 24 and 25, which will be described later, in concentric circles, respectively.

Reference numeral 22 denotes a clutch releasing coil which constitutes an advanced side clutch releasing mechanism together with the lock releasing lever 14.
The clutch release coil 22 is formed as an annular coil having a maximum diameter as shown in FIG. 2, and is axially opposed to the distal end side of the lever portion 14 </ b> D of the lock release lever 14.

Then, the clutch release coil 22 applies a braking force to the lever portion 14 D of the lock release lever 14 by being energized by energization from the control unit 26, which will be described later, and pushes the lock release lever 14 to the carrier 10. It is relatively rotated in the direction of arrow B in FIG. For this reason, the lock release lever 14 has a notch 14B shown in FIG.
As a result, the engaging portion 15B of the spring clutch 15 is relatively moved in the constraint release direction (the direction of arrow B).

As a result, the spring clutch 15 operates so that the engaging portion 15B side is slightly separated from the outer peripheral surface of the ring drum 6 shown in FIG. 2, and the cam shaft 2 (ring drum 6) is driven by the driving sprocket 1 (carrier). 10)
, Relative rotation in the advance angle direction to accelerate the rotation phase becomes possible.

Numeral 23 denotes a clutch release coil which constitutes a retard side clutch release mechanism together with the release ring 18. The clutch release coil 23 is formed as an annular coil smaller in diameter than the clutch release coil 22, as shown in FIG. It faces the surface of the release ring 18 in the axial direction. The clutch release coil 23 applies a braking force to the release ring 18 by being energized by energization from the control unit 26, and moves the release ring 18 relative to the brake drum 13 in the direction indicated by arrow B in FIG. Rotate.

Reference numeral 24 denotes the disk unit 1 of the brake drum 13.
3A together with a brake control coil constituting an electromagnetic brake for advancing angle control. The brake control coil 24 is excited by a control signal from a control unit 26 to generate a braking force fb as illustrated in FIGS. Is applied to the disk portion 13A of the brake drum 13.

In this case, the braking force fb by the brake control coil 24 is variably controlled so as to gradually increase in accordance with the engine speed N as shown in FIG.
At the time of the retard control, as shown in FIG. 13, it is variably controlled so as to gradually decrease as the engine speed N increases.

The brake control coil 24 decelerates the rotation of the brake drum 13 according to the braking force fb at this time.
It is relatively rotated in the direction of arrow B in FIG.

A brake control coil 25 constitutes an electromagnetic brake for retard control together with the rotary drum 3 on the camshaft 2 side. The brake control coil 25 is energized by a control signal from a control unit 26. 12, for applying a braking force fc to the rotating drum 3 as illustrated in FIG.

In this case, the braking force fc by the brake control coil 25 is variably controlled so as to gradually decrease as the engine speed N increases during the advance control as shown in FIG. As shown in FIG. 14, it is variably controlled so as to gradually increase in accordance with the engine speed N.

Then, the brake control coil 25 reduces the rotation of the camshaft 2 together with the rotary drum 3 in accordance with the braking force fc at this time.
Is rotated relative to the carrier 10 (drive sprocket 1) in the direction of arrow B in FIG.

Reference numeral 26 denotes a control unit constituted by a microcomputer or the like. As shown in FIG.
The output side is connected to a rotation angle sensor 27, a crank angle sensor 28, an air flow meter 29, etc., and the output side is a clutch release coils 22, 23 and brake control coils 24, 25.
Etc. are connected.

Also, the control unit 26
M, a RAM, and the like. The storage unit 26A stores a program for valve timing control processing shown in FIGS. 8 to 10 and stores a brake control map and the like shown in FIGS. 11 to 14 in the storage unit 26A. Stored. Then, the control unit 26 is configured as shown in FIGS.
In accordance with the program shown in FIG. 1, phase holding control for variably controlling the rotation phase of the camshaft 2 with respect to the driving sprocket 1, advance control, retard control processing, and the like are performed.

Here, in the brake control map shown in FIG. 11, the braking force fb applied to the brake drum 13 by the advance brake control coil 24 increases the engine speed N from a low speed to a high speed. Sometimes, it is set in advance so as to gradually increase along the characteristic line 30.

The brake control map shown in FIG. 12 shows that the braking force fc applied to the rotary drum 3 by the brake control coil 25 on the retard side increases the engine speed N from a low speed to a high speed. Sometimes, it is set in advance so as to gradually decrease along the characteristic line 31.

On the other hand, the brake control map shown in FIG. 13 shows that the braking force fb applied to the brake drum 13 by the advance brake control coil 24 is increased when the engine speed N increases from a low speed to a high speed. Is set in advance so as to gradually decrease along the characteristic line 32.

Further, the brake braking force control map shown in FIG. 14 shows that the braking force fc applied to the rotating drum 3 by the brake control coil 25 on the retard side changes the engine rotation speed N from a low rotation speed to a high rotation speed. It is set in advance so as to gradually increase along the characteristic line 33 when increasing.

The engine speed N shown in FIGS. 11 to 14 may be detected by using the crank angle sensor 28 or the like, or may be obtained by estimating from the operating state of the engine. The braking forces fb and fc may be variably controlled by changing the amount of current supplied to the brake control coils 24 and 25 according to the engine speed N.

The valve timing control apparatus for an internal combustion engine according to the present embodiment has the above-described configuration. Next, a valve timing control process performed by the control unit 26 will be described with reference to FIGS. .

First, when the vehicle engine is started to start the processing operation, in step 1, the rotation angle (rotation phase) of the camshaft 2 is read from the rotation angle sensor 27, and the crankshaft The rotation angle (rotation phase) is read, and the current phase angle θx is detected from the difference between the two rotation angles.

Next, at step 2, the operating state of the engine is determined according to the engine speed N by the crank angle sensor 28, the intake air amount by the air flow meter 29, and the like.
The target phase angle θa corresponding to this operation state is calculated and obtained. Then, in step 3, a deviation Δθ of the phase angle is calculated from the difference between the target phase angle θa and the current phase angle θx as in the following equation 1.

[0097]

Equation 1 Δθ = θa−θx

Next, the routine proceeds to step 4, where it is determined whether or not the absolute value of the deviation Δθ is within a range of a reference value e (for example, an angle of about 1 to 2 degrees) as shown in the following equation (2).

[0099]

| Δθ | ≦ e

Then, if "YES" is determined in step 4, it means that the current phase angle θx is substantially equal to the target phase angle θa. The rotation phase of the camshaft 2 with respect to 1 is maintained in this state.

That is, when performing the phase holding control, as shown in Table 1 below, all the energizations to the clutch release coils 22, 23 and the brake control coils 24, 25 are stopped, and these coils 22, 23, 24, 25 are all kept in a demagnetized state. When the drive sprocket 1 rotates clockwise (in the direction indicated by the arrow A in FIG. 5) in this state, the carrier 10 rotates together with the planetary gears 12 in the same direction, and the revolution of the planetary gears 12 causes the sun gear 13B to rotate. Through the brake drum 13.

At this time, the spring clutch 1 on the retard side
7 restricts the rotation of the rotary drum 3 relative to the brake drum 13 in the retarded direction as shown in Table 2 below, so that the rotary drum 3 rotates integrally with the brake drum 13 and thereby the camshaft. 2 rotates at the same speed in the same direction while maintaining the rotation phase with respect to the drive sprocket 1.

In this state, when a rotational force in the advance direction acts on the camshaft 2 by the load torque (see FIG. 23) accompanying opening and closing of the intake valve or the exhaust valve, the drum of the ring drum 6 and the carrier 10 As shown in Table 2 below, the ring drum 6 is connected to the drum portion 10
In order to restrain relative rotation in the advance direction with respect to D,
The ring drum 6 is held so as to rotate integrally with the carrier 10 at the same speed.

When a rotational force in the retard direction acts on the camshaft 2 due to the load torque, the rotation of the rotary drum 3 relative to the brake drum 13 in the retard direction as described above is retarded. The rotation drum 3 rotates integrally with the brake drum 13 because the rotation drum 3 is restrained by the spring clutch 17.

As described above, while the rotation phase holding control is being performed in step 5, the stepped cylinder 5 on the camshaft 2 side is controlled.
And the carrier 10 on the drive sprocket 1 side rotate integrally, and the internal gear 5C of the stepped cylindrical body 5 regulates (restrains) the rotation of the planetary gear 12 in a state of meshing with the planetary gear 12.

Therefore, only the orbital motion (rotation of the carrier 10) of the planetary gear 12 is transmitted to the brake drum 13 via the sun gear 13B, and the camshaft 2 rotates relative to the drive sprocket 1 as described above. While rotating in the same direction at the same speed. After the phase holding control in step 5, the next step 6
And the process from step 1 is repeated.

If the determination in step 4 is NO, it means that the difference between the current phase angle θx and the target phase angle θa is larger than the reference value e. It is determined whether Δθ is a positive value (Δθ> 0).

Then, if "YES" is determined in the step 7, it means that the current phase angle θx is smaller than the target phase angle θa. Therefore, the process proceeds to the next step 8, and the advance angle control shown in FIG. Process and drive sprocket 1
, The phase angle deviation Δθ is controlled to approach zero by advancing the rotational phase of the camshaft 2 with respect to.
Thereafter, the process returns in step 6, and the processes in step 1 and thereafter are repeated.

If the determination in step 7 is "NO", it means that the current phase angle .theta.x is larger than the target phase angle .theta.a. By performing the processing and delaying the rotation phase of the camshaft 2 with respect to the driving sprocket 1, the phase angle deviation Δθ is controlled to approach zero.
Then, after that, the process returns in step 6 and step 1
The subsequent processing is repeated.

[0110]

[Table 1]

[0111]

[Table 2]

Next, the advance angle control process shown in FIG. 9 will be described. In step 11, the engine speed N is read, and in the next step 12, the advance angle control for advancing the rotational phase of the camshaft 2 with respect to the driving sprocket 1 is performed. As shown in Table 1, the clutch release coil 23 is demagnetized and the clutch release coil 22 is energized by energization to operate the lock release lever 14 as shown in Table 1.

As a result, the braking lever by the electromagnetic force is applied to the lock release lever 14, so that the lock release lever 14 instantaneously rotates relative to the opposite direction (the direction of arrow B in FIG. 5).
As shown in (1), the rotation constraint in the advance direction by the advance side spring clutch 15 is forcibly released.

In step 13 shown in FIG. 9, the braking force fb corresponding to the engine speed N at this time is read out along the characteristic line 30 with reference to the brake control map shown in FIG. Then, in order to apply the braking force fb to the brake drum 13 at this time, the brake control coil 24 is excited by energization.

In step 14, the braking force fc corresponding to the engine speed N at this time is read out along the characteristic line 31 with reference to the brake control map shown in FIG.
Then, in order to apply the braking force fc at this time to the rotating drum 3, the brake control coil 25 is excited by energization.
Then, the process returns in step 15 and repeats the processing in step 1 and subsequent steps shown in FIG.

In this case, when the engine speed is low as indicated by the characteristic line S1 shown in FIG. 23, the load torque on the retard side and the advance side added to the camshaft 2 from the valve side is extremely low. large. Therefore, step 12
By simply exciting the clutch release coil 22 and releasing the spring clutch 15 on the advance side, the advance angle control can be performed using this load torque.

However, when the engine speed N is low, for example, close to the idling speed, the load torque on the advance side is very large. The shaft 2 may be excessively driven in the advance direction due to the load torque, and it is difficult to finely control the rotation phase of the camshaft 2.

Therefore, when the engine speed N is low, a relatively large braking force fc is applied to the rotary drum 3 on the camshaft 2 side as shown by a characteristic line 31 in FIG. Is suppressed from being excessively driven in the acceleration (advance) direction due to the influence of the load torque on the advance side, and the rotational phase of the camshaft 2 can be finely controlled in the advance direction.

When the engine speed N gradually increases from a low speed to a high speed, the characteristic line S shown in FIG.
2, the amplitude becomes large, but the frequency becomes high, and the phase converters such as the camshaft 2 and the planetary gear mechanism 9 become inertial dampers, and the torque becomes equivalently small.

Therefore, it is difficult to change the rotational phase of the camshaft 2 in the advance direction by using the load torque on the advance side simply by releasing the spring clutch 15 on the advance side. Then, the load torque on the advance side becomes insufficient in torque to relatively rotate the camshaft 2 in the advance direction, and the valve timing control in the advance direction cannot be performed smoothly.

In step 13, the braking force fb applied from the brake control coil 24 to the brake drum 13 is gradually increased as the engine speed N increases as shown by a characteristic line 30 in FIG. I have. In step 14, the brake control coil 25
, The braking force fc applied to the rotary drum 3 is gradually reduced as the engine speed N increases as indicated by a characteristic line 31 shown in FIG.

As a result, the brake drum 13 is braked in the clockwise rotation by the braking force fb from the brake control coil 24, so that the stepped cylinder 5,
Counterclockwise direction with respect to the carrier 10 (arrow B in FIG. 5)
Direction).

The brake drum 13 is connected to the sun gear 1
By rotating in the direction of arrow B together with 3B, a rotational reaction force in the direction of arrow C is transmitted to the planetary gear 12 on the carrier 10 side, and the planetary gear 12 is inserted into the gear insertion hole 10A of the carrier 10. The robot is caused to rotate in the direction indicated by arrow C in FIG.

Therefore, the camshaft 2 is connected to the planetary gear 1
The rotation in the advance direction, which advances the rotation phase, is transmitted from 2 to the internal gear 5C of the stepped cylinder 5, and the speed of the drive sprocket 1 is increased several times in the same direction (the direction of arrow A in FIG. 5). Being rotated. Thereby, the camshaft 2 can be driven in the advance direction so as to compensate for the insufficient torque of the load torque, and the advance control of the valve timing can be stably performed even when the engine speed becomes high.

At this time, even when the load torque on the valve side gradually decreases as the engine speed N increases, the braking force fb by the brake control coil 24 does not change according to the characteristic line 30 shown in FIG. Thus, the engine speed N is gradually increased as the engine speed N increases.

As a result, the difference in the number of revolutions of the brake drum 13 with respect to the carrier 10 increases in accordance with the braking force.
As the rotation speed of the planetary gear 12 increases, the camshaft 2 is transmitted from the planetary gear 12 through the internal gear 5C in the advance direction to advance the rotation phase, whereby the cam is rotated so as to compensate for the torque shortage. The shaft 2 can be reliably driven in the advance direction.

At the stage where the engine speed N has increased, the braking force fc applied to the rotating drum 3 from the brake control coil 25 by the processing of step 14 is shown in FIG.
, The rotation of the camshaft 2 is hardly decelerated by the braking force fc at this time, and the braking force fb applied to the brake drum 13 from the brake control coil 24 is reduced. Thus, the advance angle control is smoothly performed.

Next, the retard control process shown in FIG. 10 will be described. In step 21, the engine speed N is read, and in the next step 22, the retard control for delaying the rotational phase of the camshaft 2 with respect to the driving sprocket 1 is performed. As shown in Table 1, while the clutch release coil 22 is demagnetized, the clutch release coil 23 is energized by energization, and the electromagnetic force from the coil 23 applies a braking force to the release ring 18.

As a result, the release ring 18 operates so as to rotate instantaneously relative to the brake drum 13 in the opposite direction (the direction indicated by the arrow B in FIG. 5). Is forcibly released by the spring clutch 17 in the retard direction.

Then, in step 23 shown in FIG.
Referring to the brake control map shown in FIG. 13, the braking force fb corresponding to the engine speed N at this time is read out along the characteristic line 32. Then, in order to apply the braking force fb to the brake drum 13 at this time, the brake control coil 24 is excited by energization.

In step 24, the braking force fc corresponding to the engine speed N at this time is read out along the characteristic line 33 with reference to the brake control map shown in FIG.
Then, in order to apply the braking force fc at this time to the rotating drum 3, the brake control coil 25 is excited by energization.
Then, the process returns in step 25, and repeats the processing in step 1 and subsequent steps shown in FIG.

Even when the retard control is performed as described above, when the engine speed N is low, for example, close to the idling speed, the load torque on the retard side is very large. At the moment when the clutch 17 is released, the camshaft 2 may be excessively driven in the retard direction due to the influence of the load torque.
It becomes difficult to finely control the rotation phase of the.

When the engine speed N is low, a relatively large braking force fb is applied to the brake drum 13 as shown by a characteristic line 32 in FIG. Causes a rotational speed difference to cause the planetary gear 12 to rotate.

As a result, the rotation in the advance direction which advances the rotation phase is transmitted from the planetary gear 12 through the internal gear 5C to the camshaft 2, so that the camshaft 2 is decelerated under the influence of the load torque on the retard side. Excessive drive in the (retard) direction can be suppressed, and the rotational phase of the camshaft 2 can be finely controlled in the retard direction.

When the engine speed N gradually increases from a low speed to a high speed, the characteristic line S shown in FIG.
Since the load torque becomes equivalently small as shown in FIG. 2, it is difficult to change the rotational phase of the camshaft 2 in the retard direction simply by releasing the spring clutch 17 on the retard side.

In step 23, the braking force fb applied from the brake control coil 24 to the brake drum 13 is gradually reduced as the engine speed N increases as indicated by a characteristic line 32 shown in FIG. In step 24, the braking force fc applied from the brake control coil 25 to the rotary drum 3 is gradually increased according to the engine speed N as indicated by a characteristic line 33 shown in FIG.

As a result, when the engine speed N increases, the braking force fc applied to the rotary drum 3 from the brake control coil 25 by the processing of step 24 can be increased as shown by a characteristic line 33 in FIG. The rotation of the camshaft 2 can be reliably reduced by the braking force fc at that time.

As a result, by reducing the rotation of the camshaft 2, the rotation phase of the camshaft 2 can be reliably delayed, and the retard control can be performed smoothly.
Then, the phase of the camshaft 2 can be changed in the retard direction so as to compensate for the insufficient torque of the load torque, and stable retard control of the valve timing can be realized even when the engine speed becomes high.

When the engine speed N has increased, the braking force fb applied to the brake drum 13 from the brake control coil 24 by the processing in step 23 is as follows.
Since it is greatly reduced as shown by the characteristic line 32 in FIG.
At this time, the rotation of the camshaft 2 is hardly affected by the braking force fb, and the brake control coil 25
The retard angle control is smoothly performed by the braking force fc applied to the rotary drum 3 from.

Thus, according to the present embodiment, even if the load torque accompanying the opening and closing of the intake valve or the exhaust valve affects the camshaft 2, the braking force fb by the brake control coils 24 and 25 is maintained. , Fc are variably controlled in accordance with the engine speed N, so that in the low engine speed range, the responsiveness of the phase control can be suppressed from becoming too fast with the braking forces fb, fc. It is possible to control to finely change the rotation phase (phase angle) of the camshaft 2 with respect to the driving sprocket 1.

When the engine speed N increases from a low speed to a high speed, the braking force fb is gradually increased during the advance control as shown by a characteristic line 30 in FIG. By gradually increasing fc as indicated by a characteristic line 33 shown in FIG. 14, the responsiveness of the phase control can be improved, and quick control is possible.

As a result, the camshaft 2 from the valve side
Is equivalently reduced as the engine speed increases, as indicated by a characteristic line S2 shown in FIG. 23, and compensates for, for example, the occurrence of insufficient torque when the phase is changed. Thus, the braking force by the brake control coils 24 and 25 can be increased, and the rotational phase of the camshaft 2 can be changed stably.

Therefore, according to the present embodiment, between the driving sprocket 1 and the camshaft 2, the planetary gear mechanism 9 of the same-direction speed increasing type, the lock release lever 14, the spring clutches 15 and 17, and the release ring 18 are provided. , The rotational phase of the camshaft 2 with respect to the driving sprocket 1 can be variably controlled, and the advance and retard of the rotational phase can be controlled. And the holding control can be performed with high accuracy.

By controlling the braking forces fb and fc applied to the brake drum 13 and the rotary drum 3 using the brake control coils 24 and 25 variably according to the engine speed N, the cam for the drive sprocket 1 is controlled. The rotational phase of the shaft 2 can be smoothly changed, the influence of the load torque is suppressed by the braking forces fb and fc, and the advance, retard and hold of the rotational phase can be controlled with high precision.

Further, according to the present embodiment, the rotation phase of the camshaft 2 can be finely controlled over the entire rotation speed range of the automobile engine, and the responsiveness and stability of the phase control can be improved. it can. And drive sprocket 1
, The rotational phase of the camshaft 2 can be reliably changed on both the advance side and the retard side, and the opening and closing timings of the intake valve and the exhaust valve can be controlled stably over the entire operation range.

Further, since the variable control of the rotation phase by the planetary gear mechanism 9 is performed by electrical control using electromagnetic brakes such as the brake control coils 24 and 25, maintenance is performed in comparison with control using hydraulic pressure, for example. In addition, the inspection work can be facilitated, and the occurrence of troubles due to air mixing can be eliminated.

FIGS. 15 to 20 show a second embodiment of the present invention.
This embodiment is characterized in that the same electromagnetic coil is used for both the clutch release coil on the advance side and the brake control coil. Note that, in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 41 denotes a brake drum employed in the present embodiment. The brake drum 41 has substantially the same configuration as the brake drum 13 described in the first embodiment, and includes a disk portion 41A, , A sun gear 41B and a drum section 41C.

Reference numeral 42 denotes a lock release lever employed in the present embodiment. The lock release lever 42 has substantially the same configuration as the lock release lever 14 described in the first embodiment. It has a notch 42B, an annular plate portion 42C, a lever portion 42D, and the like. The lever portion 42D of the lock release lever 42 extends to a position surrounding the disk portion 41A of the brake drum 41 from the radial outside, as shown in FIG. Facing each other.

Reference numeral 43 denotes a support frame fixed to the cylinder head side of the engine. The support frame 43 has substantially the same configuration as the support frame 19 described in the first embodiment. Bolt hole 4 as shown in 15
3A and the like are provided. The support frame 43 is mounted on the cylinder head side of the engine using bolt holes 43A and the like.

Reference numeral 44 denotes a coil holder fixed in the support frame 43 using the pins 21 and the like.
Includes a control coil 45 and a clutch release coil 46 which will be described later.
Are arranged concentrically with each other.

Reference numeral 45 denotes a control coil as an electromagnetic coil disposed near the outer periphery of the coil holder 44. The control coil 45 is provided on the disk portion 41A of the brake drum 41.
A brake control coil constituting an electromagnetic brake together with
The lock release lever 42 is also used as a clutch release coil that constitutes a clutch release mechanism on the advance side.

As shown in FIG. 16, the control coil 45 is axially opposed to the disk portion 41A of the brake drum 41 and the tip end of the lever portion 42D of the lock release lever 42. The control coil 45 applies a braking force fd as illustrated in FIG. 20 to the disk portion 41A of the brake drum 41 and the lever portion 42D of the lock release lever 42 by energization from a control unit 47 described later. .

Reference numeral 46 denotes a clutch release coil which constitutes a retard side clutch release mechanism together with the release ring 18. The clutch release coil 46 is disposed near the inner peripheral side of the coil holder 44, and is disposed on the surface of the release ring 18. They face each other in the axial direction. Similarly to the clutch release coil 23 described in the first embodiment, the clutch release coil 46 applies a braking force to the release ring 18 by being energized by energization from the control unit 47, and Is rotated relative to the brake drum 41.

Reference numeral 47 denotes a control unit constituted by a microcomputer or the like. The control unit 47 has the input side on the camshaft 2 side as shown in FIG. 17 in the same manner as the control unit 26 described in the first embodiment. Rotation angle sensor 27, crank angle sensor 28
And the air flow meter 29, etc.
The output side is connected to a control coil 45, a clutch release coil 46, and the like.

The control unit 47 is provided with the RO
For example, in FIG.
A program for valve timing control processing shown in FIGS. 18 and 19 is stored, and a brake control map and the like shown in FIG. 20 are stored. The control unit 47 performs phase holding control, advance control, retard control, and the like for variably controlling the rotational phase of the camshaft 2 with respect to the drive sprocket 1 according to the programs shown in FIGS. 8, 18, and 19. Things.

Here, the brake control map shown in FIG. 20 is such that the braking force fd applied to the brake drum 41 by the control coil 45 is increased or decreased as indicated by a characteristic line 48 according to the engine speed N during the advance control. It is set in advance.

That is, the brake control map shown in FIG. 20 shows that when the engine speed N increases from the idling speed to a predetermined speed (for example, about 1000 to 1500 rpm), the braking force fd is plotted along the characteristic line 48. When the engine rotational speed N increases from a predetermined rotational speed to a high rotational speed, the energization of the control coil 45 is controlled so as to gradually increase from the minimum braking force fd1 to the minimum braking force fd1. Is what you do.

In this case, the minimum braking force fd1 corresponds to the minimum required braking force, for example, when the lock release lever 42 is operated to release the advance side spring clutch 15. It can be decided.

The valve timing control apparatus for an internal combustion engine according to the present embodiment has the above-described configuration. Next, the valve timing control processing by the control unit 47 will be described with reference to FIG. 8, FIG. 18 to FIG. Will be explained.

First, when the vehicle engine is started and the processing operation is started, substantially the same processing as in the first embodiment is performed along steps 1 to 9 shown in FIG. Then, the processing operation is performed according to the program shown in FIG. 18 during the advance control, and the processing operation is performed according to the program shown in FIG. 19 during the retard control.

[0162]

[Table 3]

Here, the advance angle control process shown in FIG. 18 will be described. In step 31, the engine speed N is read, and in the next step 32, the advance angle control for advancing the rotational phase of the camshaft 2 with respect to the driving sprocket 1 is performed. As shown in Table 3, while the clutch release coil 46 is demagnetized, the control coil 45 is energized by energization, the lock release lever 42 is operated, and a braking force by electromagnetic force is applied to the lock release lever 42. This forcibly releases the rotation constraint in the advance direction by the advance side spring clutch 15.

Then, in step 33 shown in FIG.
Referring to the brake control map shown in FIG. 20, the braking force fd corresponding to the engine speed N at this time is read out along the characteristic line 48. Then, in order to apply the braking force fd to the brake drum 41 at this time, the amount of electricity supplied to the control coil 45 is variably controlled. Then, the process returns in step 34, and repeats, for example, the processing in step 1 and subsequent steps shown in FIG.

In this case, when the engine speed N is low, for example, close to the idling speed, the load torque on the advance side is very large as described above. In addition, the camshaft 2 may be excessively driven in the advance direction due to the influence of the load torque, and it is difficult to finely control the rotation phase of the camshaft 2.

Therefore, when the engine speed N is equal to the predetermined speed N
When the rotation speed is lower than 1, for example, a braking force fd larger than the minimum braking force fd1 is applied from the control coil 45 to the disk portion 41A of the brake drum 41 along a characteristic line 48 shown in FIG. Excessive driving of the shaft 2 in the acceleration (advance) direction due to the influence of the load torque on the advance side is suppressed, and the rotational phase of the camshaft 2 can be finely controlled in the advance direction.

When the engine speed N is equal to the predetermined speed N
When it increases to 1, the braking force fd is reduced to the minimum braking force fd1
At this time, the advance angle side spring clutch 15 is only released, and the advance angle control is performed by using the advance side load torque added to the camshaft 2 from the valve side.

When the engine speed N is equal to the predetermined speed N1
When the rotational speed gradually increases, the torque equivalently decreases as indicated by a characteristic line S2 shown in FIG. 23. Therefore, the braking force fd applied from the control coil 45 to the brake drum 41 is shown in FIG. As indicated by a characteristic line 48 in FIG. 20, the engine speed N is gradually increased as the engine speed N increases.

As a result, the brake drum 41 is braked in the clockwise rotation by the braking force fd from the control coil 45, so that the brake drum 41 rotates counterclockwise relative to the stepped cylinder 5 and the carrier 10. I will be. By transmitting a rotational reaction force to the planetary gear 12 on the carrier 10 side, the planetary gear 12 is
The rotation motion is performed in the gear insertion hole 10A of No. 0.

Therefore, the camshaft 2 is connected to the planetary gear 1
The rotation in the advance direction that advances the rotation phase is transmitted from 2 to the internal gear 5C of the stepped cylinder 5, and the drive sprocket 1 rotates at a speed several times higher in the same direction. This allows the camshaft 2 to compensate for the load torque shortage.
Can be driven in the advance direction, and even at the stage when the engine speed becomes high, stable advance control of the valve timing can be realized.

Next, the retard control process shown in FIG. 19 will be described. In step 41, the engine speed N is read, and in the next step 42, the retard control for delaying the rotational phase of the camshaft 2 with respect to the driving sprocket 1 is performed. As shown in Table 3, the control coil 45 and the clutch release coil 46 are energized by energization, and a braking force is applied to the release ring 18 by the electromagnetic force from the coil 46.

As a result, the release ring 18 operates so as to instantaneously rotate in the opposite direction with respect to the brake drum 41, for example, and forcibly restricts the rotation in the retard direction by the spring clutch 17 on the retard side. Release.

In step 43 shown in FIG.
With reference to a brake control map for retard control (for example, a control map similar to the characteristic line 32 shown in FIG. 13), the braking force corresponding to the engine speed N at this time is read out along the characteristic line 32. Then, the amount of current supplied to the control coil 45 is controlled to apply the braking force fd (corresponding to the braking force fb in FIG. 13) to the brake drum 41 at this time.

Even when the retard control is performed as described above, when the engine speed N is, for example, a low speed close to the idling speed, the load torque on the retard side is very large. At the moment when the clutch 17 is released, the camshaft 2 may be excessively driven in the retard direction due to the influence of the load torque.
It becomes difficult to finely control the rotation phase of the.

When the engine speed N is low, a relatively large braking force fd is applied to the brake drum 13 as shown by a characteristic line 32 in FIG. Causes a rotational speed difference to cause the planetary gear 12 to rotate.

As a result, the rotation in the advance direction which advances the rotation phase is transmitted from the planetary gear 12 via the internal gear 5C to the camshaft 2, so that the camshaft 2 is decelerated by the load torque on the retard side. Excessive drive in the (retard) direction can be suppressed, and the rotational phase of the camshaft 2 can be finely controlled in the retard direction.

When the engine speed N increases from a low speed to a high speed, the braking force is gradually reduced in response to this, as indicated by a characteristic line 32 shown in FIG. The retard control is performed using the torque. That is,
As shown by the characteristic lines S1 and S2 in FIG. 23, the load torque on the retard side is larger than the load torque on the advance side, so that the rotational phase of the camshaft 2 can be changed in the retard direction by using this. it can.

In this case, the control coil 45 is substantially demagnetized, and the brake drum 41 rotates at substantially the same speed as the carrier 10, but between the brake drum 41 and the rotary drum 3 via the spring clutch 17. Is released, the rotational force from the driving sprocket 1 is not transmitted to the camshaft 2, and the rotational phase of the camshaft 2 is retarded so as to be gradually delayed with respect to the driving sprocket 1. .

Thus, in the present embodiment configured as described above, substantially the same operation and effect as those of the first embodiment can be obtained. In particular, in the present embodiment, a single control coil 45 is used. Thus, the brake control coil for the brake drum 41 and the clutch release coil for the lock release lever 42 can be used, and the number of parts can be reduced, and the workability during assembly can be improved.

That is, in this embodiment, in order to perform the clutch release control and the brake control using a single control coil 45, the braking force fd by the control coil 45 is changed by a characteristic line 48 shown in FIG. Until the engine speed reaches a predetermined speed N1 (for example, approximately 1000 to 1500 rpm), the braking force is gradually reduced to fd1.
When the rotation speed exceeds a predetermined rotation speed N1, the braking force fd is gradually increased.

As a result, the amount of energization to the single control coil 45 is variably controlled to apply the minimum braking force fd1 to the lever portion 42D of the lock release lever 42 and to apply a minimum force to the disk portion 41A of the brake drum 41. Figure 20
And the braking force fd along the characteristic line 48 shown in FIG.

As described above, even when the engine speed increases and the load torque on the valve side decreases, the control coil 45 is excited to apply a common braking force to the brake drum 41 and the unlock lever 42. Accordingly, a rotational force in the advance angle direction by the planetary gear mechanism 9 can be applied to the camshaft 2, and the insufficient torque on the load torque side can be reliably compensated.

In the second embodiment, the case where the single control coil 45 is used as both the brake control coil for the brake drum 41 and the clutch release coil for the lock release lever 42 will be described as an example. However, the present invention is not limited to this. For example, as shown in a modified example shown in FIG.
And a clutch release coil 5 for the lock release lever 42 '.
1 and a brake control coil 5 for the brake drum 41 '
2 may be provided separately.

In this case, a clutch release mechanism for releasing the advance side spring clutch 15 is provided.
A lock release lever 42 'and a clutch release coil 51 can be used.
The spring clutch 15 can be released by exciting the motor 1 to apply a braking force to the lock release lever 42 '.

Further, in the second embodiment, it has been described that the retard control is performed without using the brake control coil for the retard control. Instead, for example, in the first embodiment, the retard control is performed. Brake control coil 2 for retard control used
5 may be provided with the same brake control coil.

In each of the above embodiments, the case where the rotating body is constituted by the driving sprocket 1 has been described as an example. However, the present invention is not limited to this. For example, the rotating body is constituted by using a timing pulley or the like. And in this case,
What is necessary is just to connect between a crankshaft side and a timing pulley by a timing belt or the like.

Further, in each of the above embodiments, the advance angle side,
Although the case where the spring clutches 15 and 17 are used as the one-way clutch on the retard side has been described as an example, the present invention is not limited to this. For example, a one-way clutch using a ratchet, a top, or the like may be adopted.

[0188]

As described in detail above, according to the first aspect of the present invention, a phase in which the rotation phase of the camshaft with respect to the rotating body is changed by electrical control by applying a braking force using an electromagnetic brake. A change mechanism, wherein the phase change mechanism is configured to variably control the braking force of the electromagnetic brake in accordance with the rotation speed of the internal combustion engine, so that the load torque associated with opening and closing of the intake or exhaust valve. Even if the influence of (1) is exerted on the camshaft, by controlling the braking force of the electromagnetic brake variably in accordance with the engine speed, the responsiveness of the phase control can be improved in a high speed range, and quick control becomes possible. In the low rotation speed range, the response of the phase control can be prevented from becoming too fast, and the control can be performed so as to finely change the rotation phase of the camshaft.

Therefore, the rotational phase of the camshaft can be finely controlled over the entire rotational speed range of the internal combustion engine, and the responsiveness and stability of the phase control can be improved. The rotation phase of the camshaft with respect to the rotating body can be reliably changed on both the advance side and the retard side, and the opening and closing timing of the intake valve and the exhaust valve can be controlled stably over the entire operation range.

According to the second aspect of the present invention, since the electromagnetic brake is configured to gradually increase the braking force as the rotational speed of the internal combustion engine increases, the load torque applied to the camshaft is reduced by the engine rotational speed. The number decreases as the number increases. For example, even if a torque shortage occurs when the phase is changed, the braking force of the electromagnetic brake can be increased to compensate for this, and the rotational phase of the camshaft is changed stably. be able to.

According to the third aspect of the invention, when the engine speed is the idling speed, a large load torque acts on the camshaft, and the response of the phase control tends to be excessively fast. This can be suppressed by the braking force of the electromagnetic brake, and control can be performed to finely change the phase angle of the rotational phase. While the engine speed increases from the idling speed to a predetermined speed, the responsiveness of the phase control can be maintained at an appropriate speed by gradually decreasing the braking force. On the other hand, when the engine speed further increases from the predetermined speed, the effect of the load torque becomes smaller, and accordingly, the responsiveness of the phase control can be improved by gradually increasing the braking force accordingly,
Quick control can be performed.

According to the fourth aspect of the present invention, the rotation phase changing means comprises a one-way clutch on the advance side, a one-way clutch on the retard side, and a clutch release mechanism on the advance side and the retard side. Since the phase changing mechanism is configured to change the rotation phase of the camshaft with respect to the rotating body in the advance direction by operating the electromagnetic brake when the one-way clutch on the advance side is released by the clutch release mechanism, The variable control of the rotation phase in the advance direction using the phase change mechanism can be automatically performed by the electrical control of the electromagnetic brake. Occurrence can be eliminated, and maintenance and inspection work can be easily performed.

According to the fifth aspect of the present invention, since the phase changing mechanism is constituted by the same-direction speed-increasing type planetary gear mechanism and the electromagnetic brake, when the braking force is applied by the electromagnetic brake, the planetary gear is changed. By operating the mechanism, the speed of the camshaft can be increased in the same direction with respect to the rotating body, and the rotation phase of the camshaft can be controlled in the advance direction. Further, when the braking force by the electromagnetic brake is released, the rotation of the planetary gear is restricted, and the operation as the phase changing mechanism can be kept stopped.

According to a sixth aspect of the present invention, the planetary gear mechanism includes a first rotating member on which the planetary gear is rotatably supported, and a second rotating member having an internal gear meshed with the planetary gear. And a third rotating member formed with a sun gear meshing with the planetary gear, and an advance side, a retard angle between the first and third rotating members and the second rotating member. Side one-way clutch is provided, and the electromagnetic brake is configured to apply a braking force to the third rotating member. Therefore, a braking force is applied to the third rotating member by the electromagnetic brake to cause the first rotating member and the third rotating member to rotate. When relative rotation is generated between the rotating member and the planetary gear, the planetary gear rotates and the second rotating member can be rotated at a higher speed than the first rotating member in the same direction as that of the first rotating member, thereby advancing the rotation phase of the camshaft. be able to. Further, when the braking force by the electromagnetic brake is released, the third rotating member moves to the first position.
Because the planetary gear rotates substantially integrally with the rotating member, the planetary gear performs only a revolving motion in accordance with the rotation of the first rotating member without rotating, and the rotational force from the first rotating member is transmitted to the second rotating member by the internal gear. Can be communicated via

According to the seventh aspect of the present invention, the electromagnetic brake also functions as a part of the advance-side clutch release mechanism, and uses a single electromagnetic coil to release the advance-side one-way clutch. Since the braking force is applied to the third rotating member, the advance-side clutch release mechanism and the electromagnetic brake can be configured using a single electromagnetic coil. This can be performed in combination with the operation of applying the braking force to the third rotating member.

According to the invention described in claim 8, the phase change mechanism applies a braking force to the camshaft side when the one-way clutch on the retard side is released by the clutch release mechanism, so that the phase change mechanism applies a braking force to the rotating body. An electromagnetic brake for retard control that changes the rotational phase of the camshaft in the retard direction is provided, so when changing the rotational phase of the camshaft with respect to the rotating body in the retard direction, the clutch release mechanism is used to retard the rotational phase. When the one-way clutch is released, relative rotation in the retard direction becomes possible between the rotating body and the camshaft. In this state, the electromagnetic brake for retard control is activated to apply a braking force to the camshaft. By doing so, the rotation of the camshaft can be decelerated, and the retard control can be reliably performed.

Further, according to the ninth aspect of the present invention, the load torque applied to the camshaft from the valve side decreases as the engine speed increases, and the torque is insufficient when the phase is changed in the retard direction. Occurs, the braking force can be increased to compensate for this torque shortage by the electromagnetic brake for retard control, and the rotational phase of the camshaft can be stably changed in the retard direction. When the phase is changed in the advance direction, a large load torque acts on the camshaft when the engine speed is low, and the response of the phase control tends to be excessively fast. By applying a braking force to the camshaft using the electromagnetic brake described above, the rotation of the camshaft can be decelerated to suppress excessive advance of the rotational phase.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an engine valve timing control device according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the valve timing control device shown in FIG.

FIG. 3 is a front view showing the carrier in FIG. 1 as a single body.

FIG. 4 shows the carrier together with the planetary gears.
It is sectional drawing in the -IV direction.

FIG. 5 is an exploded perspective view showing a stepped cylinder, a carrier, an advance side spring clutch, a lock release lever, a planetary gear, a brake drum, and the like in FIG. 1;

FIG. 6 is an exploded perspective view showing a brake drum, a retard side spring clutch, a release ring, a rotating drum, and the like in FIG. 1;

FIG. 7 is a control block diagram of the valve timing control device shown in FIG. 1;

FIG. 8 is a flowchart showing a valve timing control process.

FIG. 9 is a flowchart showing an advance angle control process in FIG. 8;

FIG. 10 is a flowchart showing a retard control process in FIG. 8;

FIG. 11 is a characteristic diagram showing the relationship between the engine speed and the braking force applied to the brake drum during advance control using a brake control coil on the advance side.

FIG. 12 is a characteristic diagram illustrating a relationship between an engine speed and a braking force applied to a brake drum during advance control using a retard-side brake control coil.

FIG. 13 is a characteristic diagram showing a relationship between an engine speed and a braking force applied to a brake drum during retard control using a brake control coil on the advance side.

FIG. 14 is a characteristic diagram illustrating a relationship between an engine speed and a braking force applied to a brake drum during retard control using a retard brake control coil.

FIG. 15 is a longitudinal sectional view showing an engine valve timing control device according to a second embodiment.

16 is an enlarged view of a main part of the valve timing control device shown in FIG.

17 is a control block diagram of the valve timing control device shown in FIG.

FIG. 18 is a flowchart showing advance angle control processing according to the second embodiment.

FIG. 19 is a flowchart illustrating a retard control process according to the second embodiment.

FIG. 20 is a characteristic diagram showing a relationship between an engine speed at the time of advancing control using a control coil and a braking force applied to a brake drum.

FIG. 21 is a vertical sectional view showing an engine valve timing control device according to a modification.

FIG. 22 is a characteristic diagram illustrating opening and closing operations of an exhaust valve and an intake valve.

FIG. 23 is a characteristic diagram showing a load torque acting on a camshaft.

[Explanation of symbols]

Reference Signs List 1 driving sprocket (rotating body) 2 cam shaft 3 rotating drum 5 stepped cylinder (second rotating member) 5C internal gear 6 ring drum 8 phase variable device (rotation phase variable means) 9 planetary gear mechanism (phase changing mechanism) DESCRIPTION OF SYMBOLS 10 Carrier (1st rotating member) 10D Drum part 12 Planetary gear 13, 41, 41 'Brake drum (3rd rotating member) 13B, 41B, 41B' Sun gear 14, 42, 42 'Lock release lever (clutch release) 15) Spring clutch (one-way clutch) on the advance side 17 Spring clutch (one-way clutch) on the retard side 18 Release ring (clutch release mechanism) 22, 51 Advance clutch release coil 23, 46 Clutch on the retard side Release coil 24, 52 Brake control coil on the advance side (electromagnetic brake) 25 Brake on the retard side Rk in the control coil (electromagnetic brake retarding control) 26,47 control unit 28 crank angle sensor 45 the control coil (electromagnetic brake)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G018 BA32 CA04 DA00 DA21 DA83 EA03 EA04 EA12 EA31 EA32 GA04 3G092 AA11 DA01 DA02 DA10 DG09 EA01 EA02 EA03 EA04 EA22 EC01 FA06 FA09 GA12 GA13 HA01Z HA13X HA13Z HE01Z

Claims (9)

[Claims] 1. A rotating body driven by a crankshaft of an internal combustion engine, a camshaft rotated according to the rotation of the rotating body to open and close an intake valve or an exhaust valve of the internal combustion engine, and the camshaft. And a rotation phase variable means for variably controlling a rotation phase of the camshaft with respect to the rotation body provided between the rotation body and the rotation body, wherein the rotation phase variable means includes an electromagnetic brake. A phase change mechanism that changes the rotation phase of the cam shaft with respect to the rotating body by electrical control by applying a braking force using the phase change mechanism. The phase change mechanism controls the electromagnetic brake according to the rotation speed of the internal combustion engine. A valve timing control device for an internal combustion engine, wherein a braking force is variably controlled. 2. The valve timing control device for an internal combustion engine according to claim 1, wherein the electromagnetic brake is configured to gradually increase the braking force as the rotational speed of the internal combustion engine increases. 3. The electromagnetic brake according to claim 1, wherein the braking force is gradually reduced until the rotation speed of the internal combustion engine reaches a predetermined rotation speed from an idling rotation speed, and the rotation speed becomes higher than the predetermined rotation speed. The valve timing control device for an internal combustion engine according to claim 1, wherein the braking force is gradually increased according to the following. 4. The phase change mechanism, the phase change mechanism, an advance one-way clutch that restricts relative rotation of the camshaft with respect to the rotating body on the advance side and allows relative rotation in the opposite direction, The relative rotation of the camshaft with respect to the rotating body is restrained on the retard side and the one-way clutch on the retard side that allows relative rotation in the opposite direction and the rotation restraint by the one-way clutch on the advance side and the retard side are individually released. The phase change mechanism is configured to actuate the electromagnetic brake when the advance side one-way clutch is released by the clutch release mechanism. 4. The valve timing control device for an internal combustion engine according to claim 1, wherein the rotation phase of the camshaft is changed in an advance direction. 5. The same-direction speed-increasing planetary gear for transmitting a rotational force between the rotating body and the camshaft so as to increase the speed of the camshaft relative to the rotating body in the same direction. 5. A gear mechanism comprising: a gear mechanism; and the electromagnetic brake for electrically controlling the operation of the planetary gear mechanism.
3. The valve timing control device for an internal combustion engine according to claim 1. 6. The planetary gear mechanism includes a first rotating member integrally provided on the rotating body and rotatably supporting the planetary gear, and a first rotating member integrally provided on the camshaft and meshing with the planetary gear. A second rotating member formed with a gear,
A third rotating member provided so as to be relatively rotatable with respect to the rotating body and the camshaft, and having a sun gear meshing with the planetary gear; The one-way clutch on the retard side is provided between one of the three rotating members and the second rotating member, and the other one of the first and third rotating members is connected to the second rotating member. 6. The valve timing control device for an internal combustion engine according to claim 5, wherein the electromagnetic brake is provided between the third rotating member and the third rotating member to apply a braking force to the third rotating member. 7. The electromagnetic brake also functions as a part of the advance-side clutch release mechanism, and uses a single electromagnetic coil to release the advance-side one-way clutch and release the one-way clutch with respect to the third rotating member. 7. The valve timing control device for an internal combustion engine according to claim 6, wherein the valve timing control device is configured to apply a braking force. 8. The phase change mechanism changes the rotational phase of the camshaft with respect to the rotating body by applying a braking force to the camshaft when the one-way clutch on the retard side is released by the clutch release mechanism. 8. The valve timing control device for an internal combustion engine according to claim 4, further comprising an electromagnetic brake for retard control that changes the retard direction. 9. The electromagnetic brake for retard control gradually increases the braking force as the rotational speed of the internal combustion engine increases when the rotational phase is changed in the retard direction, and the rotational phase of the camshaft is changed. 9. The valve timing control device for an internal combustion engine according to claim 8, wherein when changing the rotational speed of the internal combustion engine to the advance direction, the braking force is gradually reduced as the rotational speed of the internal combustion engine increases.