JPH0658049B2 - Valve drive controller for internal combustion engine - Google Patents

Description

Detailed Description of the Invention A. Object of the invention (1) Industrial field of application The present invention is an engine valve that is openably and closably supported by an engine body,
Internal combustion comprising a valve spring for urging the engine valve in the valve closing direction, and valve driving means interposed between the valve operating cam and the engine valve for transmitting the force in the valve opening direction by the valve operating cam to the engine valve The present invention relates to an engine valve control device.

(2) Conventional technology Conventionally, in addition to controlling the opening and closing of the intake valve or exhaust valve as an engine valve by the synergistic action of the valve cam and the valve spring, it can also be operated by the operation of the electromagnetic actuator according to the operating state of the engine. A controllable switch has already been known (see Japanese Utility Model Laid-Open No. 59-52111).

(3) Problems to be Solved by the Invention By the way, the applicant of the present invention proposes, in the engine valve opening / closing control device, a device that improves the performance of the engine by maximally utilizing the attractive force of the electromagnetic actuator ( Japanese Patent Application Sho 62
However, since the engine valve is opened by the excitation of the electromagnetic actuator and is closed all at once by the spring force due to the demagnetization, the valve closing timing can be controlled, but inertia supercharging is prevented. There was a problem that variable control of the valve opening timing that could be effectively used was not possible.

Therefore, the applicant of the present invention, regardless of the rotational position of the valve cam,
The valve closing state of the engine valve is maintained against the elastic force of the valve opening elastic member, and when the retaining state is released, the engine valve is opened by the elastic force of the valve opening elastic member. Therefore, a control valve for controlling the opening timing of the engine valve has already been proposed (Japanese Patent Application No. 62-237706). However,
In a specific operation state such as a high-speed operation state of the engine, there is a demand that the control of the valve opening timing is not necessary and the engine valve should be opened and closed in correspondence with the cam profile of the valve operating cam. When an engine valve is opened / closed without holding the valve closed position of the holding means, the opening / closing operation characteristic accurately corresponds to the cam profile due to the elastic operation of the valve opening elastic member provided in the valve driving means. May not be obtained.

The present invention has been made in view of the above circumstances, and opens and closes an engine valve in accordance with a cam profile of a valve operating cam and a state in which the valve opening timing control is performed and the valve opening timing control is not performed. It is an object of the present invention to provide a valve operating control device for an internal combustion engine, which can switch between simple states and possible states.

B. Configuration of the Invention (1) Means for Solving the Problems According to the present invention, the valve drive means includes a valve-opening elastic member that exerts elastic force in the valve-opening direction of the engine valve, and the engine valve and the valve operating valve. Holding means for holding the engine valve in the valve closing position while accumulating the valve opening force of the valve operating cam in the valve opening elastic member is provided between the cam and the cam. According to the above, the holding state and the holding release state are switchable so as to control the valve opening timing of the engine valve, and the valve driving means is provided with a lock mechanism for preventing the elastic operation of the valve opening elastic member.

(2) Operation According to the above configuration, in the state in which the lock mechanism is in the inoperative state, regardless of the operating state of the engine, the engine is operated by the holding means regardless of the opening / closing operation of the engine valve by the valve cam and the valve spring. The valve can be held at the valve closed position, and the valve opening force can be accumulated in the valve opening elastic member in the valve closed state. Therefore, when the holding state by the holding means is released, the engine valve opens rapidly. When the lock mechanism is operated, the elastic member for opening the valve does not elastically operate, so that the engine valve opens and closes according to the cam profile of the valve operating cam.

(3) Examples Hereinafter, examples of the present invention will be described with reference to the drawings.
First, referring to FIG. 1 showing the first embodiment of the present invention, a combustion chamber 2 and an intake port 3 communicating with the combustion chamber 2 are formed in a cylinder head 1 of an engine body E, and the intake port 3 is , Is connected to an intake system including the fuel supply device 4.
Further, the combustion chamber 2 of the intake port 3 is provided in the cylinder head 1.
An intake valve 5 is provided as an engine valve capable of opening and closing the side open end. The intake valve 5 is composed of a valve shaft portion 5a and a valve body portion 5b. The valve shaft portion 5a is slidably fitted to a valve guide 6 fixed to the cylinder head 1 and the valve body portion 5b.
Can be seated on the valve seat 7 at the open end of the intake port 3 on the combustion chamber 2 side from the combustion chamber 2 side. A spring retainer 9 is attached to the upper end of the valve shaft portion 5a via a cotter 8. Between the spring retainer 9 and the spring seat 10 formed on the cylinder head 1 facing the spring retainer 9, a valve spring 11, which is a compression coil spring,
12 is contracted, and the elastic force of these valve springs 11 and 12 urges the intake valve 5 in the valve closing direction. The spring retainer 9 is made of a magnetic material, and constitutes an electromagnetic actuator A as a holding means together with an electromagnet body 13 which will be described later.

A cam holder (not shown) provided on the cylinder head 1 rotatably supports a valve cam shaft 14 that is interlocked with and connected to a crank shaft (not shown). Valve camshaft 14
An intake cam 15 as a valve cam integrally provided in the
A valve drive means 16 for transmitting the force in the valve opening direction by the intake cam 15 to the intake valve 5 is interposed between the intake valve 5 and the intake valve 5.

The valve driving means 16 is a rocker shaft 17 fixedly arranged in parallel above the valve cam shaft 14 between the valve cam shaft 14 and the intake valve 5, and a rocker shaft for slidingly rocking on the intake cam 15. A first rocker arm 18 as a first drive member supported by the shaft 17; a second rocker arm 19 as a second drive member supported by the rocker shaft 17 so as to swing while abutting on the upper end of the intake valve 5; The torsion springs 20 and 20 are interposed between the rocker arms 18 and 19 and serve as valve-opening elastic members that exert a spring force in the valve-opening direction of the intake valve 5.

In FIG. 2, a collar 22 is attached to the rocker shaft 17 via a cylindrical sliding metal 21. The collar 22 is basically formed in a cylindrical shape, and the retaining rings 23, 23 contacting both ends thereof are fitted to the sliding metal 21. A torsion spring 20 is provided at both ends of the collar 22 in the axial direction,
Drum portions 22a, 22a for winding 20 are provided, and the base ends of the first and second rocker arms 18, 19 are located near the axial center portion of the collar 22, that is, between the drum portions 22a, 22a. It is rotatably supported.

The first rocker arm 18 extends from the rocker shaft 17 to the intake cam 15 side, and the cam surface of the intake cam 15 is in sliding contact with the lower surface of the tip end portion of the first rocker arm 18. Further, the second rocker arm 19 slides the base of the second rocker arm 19 onto the base of the first rocker arm 18 and
7 to the intake valve 5 side. A tappet screw 24, which comes into contact with the upper end of the valve shaft portion 5a of the intake valve 5, is screwed at the tip of the second rocker arm 19 so as to be able to move forward and backward. Moreover, the tappet screw 24 is screwed with a lock nut 25 that abuts against the upper surface of the tip of the second rocker arm 19 in order to maintain the adjusted forward / backward position.

Locking pins 26 and 27 parallel to the rocker shaft 17 are fixed to the first and second rocker arms 18 and 19 so as to project to both sides, and are wound around the drum portions 22a and 22a of the collar 22, respectively. Torsion spring 2
One end of 0 and 20 is a locking pin 26 of the first rocker arm 18.
, And the other end is engaged with the locking pin 27 of the second rocker arm 19, respectively. As a result, the first and second rocker arms 18 and 19 are
8 is urged toward the intake cam 15 side, and the second rocker arm 19 is urged toward the intake valve 5 side. Moreover, the resilience of both torsion springs 20 and 20 is set stronger than that of the valve springs 11 and 12. Therefore, the valve camshaft 14
When is rotated, the intake cam 15 pushes the intake valve 5 downward via the valve drive means 16 and can slide the intake valve 5 in the valve opening direction, that is, the downward direction.

Referring also to FIG. 3, an annular electromagnet body 13 that is opposed to the upper surface of the spring retainer 9 and that surrounds the valve shaft portion 5a of the intake valve 5 is fixed to the cylinder head 1. An electromagnetic actuator A is configured with the magnetic body 9 which also serves as the spring retainer. Also, the electromagnet body 13
Includes a small diameter hole 28 slidingly contacting the valve shaft portion 5a of the intake valve 5,
A through hole 30 is formed in which a large diameter hole 29 having a diameter larger than that of the small diameter hole 28 is coaxially connected from the lower side in order, and the valve shaft portion 5a of the intake valve 5 is axially movable so as to penetrate therethrough. Hole 30
Is inserted into.

When the solenoid of the electromagnet body 13 is excited, the magnetic body 9 is attracted to the electromagnet body 13. The force obtained by combining the attraction force of the electromagnetic actuator A and the spring force of the valve springs 11 and 12 is the torsion spring 20 in the valve drive means 16.
It is set stronger than the resilience of 20. Therefore, when the electromagnet body 13 is excited, the intake valve 5 maintains its closed position regardless of the rotation of the valve cam shaft 14, and the valve opening force by the intake cam 15 at that time is accumulated in the torsion springs 20 and 20. become.

A buffer mechanism D ₁ is provided between the intake valve 5 and the electromagnet body 13 to mitigate the sudden valve opening operation of the intake valve 5. The buffer mechanism D ₁ includes a hydraulic chamber 34 capable of limiting a leak amount between the step portion 32 a provided at the upper end of the intake valve 5 and the electromagnet body 13. That is, a cap-shaped valve piece 32 that slidably fits into the large diameter hole 29 of the through hole 30 is fitted to the upper end of the valve shaft portion 5 a that is inserted into the through hole 30, and is formed by this valve piece 32. A hydraulic chamber 34 is defined between the step portion 32a and the step portion 30a between the small diameter hole 28 and the large diameter hole 29. Further, an annular recess 31 is provided on the inner surface of the intermediate portion of the large-diameter hole 29 in the through hole 30, and an oil supply hole 33 communicating with the annular recess 31 is formed in the electromagnet body 13. The oil supply hole 33 serves as an oil supply source not shown. Connected. Moreover, a gap is formed between the outer surface of the valve shaft portion 5a and the inner surface of the small diameter hole 28 to the extent that the hydraulic pressure in the hydraulic chamber 34 can leak when the hydraulic pressure in the hydraulic chamber 34 increases. Further, the valve piece 32 is fitted to the valve shaft portion 5a such that the upper portion of the valve piece 32 projects upward from the upper end of the through hole 30 in a state where the intake valve 5 is in the closed position. The screw 24 abuts on the valve piece 32.

In FIG. 4, a lock mechanism R ₁ is provided between the first and second rocker arms 18 and 19 of the valve drive means 16. This lock mechanism R ₁ is provided with torsion springs 20, 20.
The lock member 51 capable of blocking the relative rotation of both rocker arms 18, 19 against the spring force of the lock member 51 and slidably fitted to the second rocker arm 19, and the lock member 51.
The hydraulic chamber 52 provided in the second rocker arm 19 so as to face the rear surface of the lock member 51 so as to exert the hydraulic pressure to bring the hydraulic lock chamber 51 into contact with the first rocker arm 18, and the lock member 51 is attached in a direction to contract the hydraulic chamber 52. Biasing return spring 53
With.

The second rocker arm 19 is provided with a bottomed sliding hole 54 that opens toward the first rocker arm 18, and a double cylindrical spring receiving member 55 is provided at the opening end of the sliding hole 54. The lock member 51, which is screwed and is slidably fitted in the slide hole 54, can be projected from the second rocker arm 19 in a direction in which the lock member 51 is guided by the spring receiving member 55 and abuts on the second rocker arm 18. Is. The return spring 53 is contracted between the spring receiving member 55 and the lock member 51. Further, the hydraulic chamber 52 is defined between the lock member 51 and the closed end of the sliding hole 54, and the hydraulic chamber 52 communicates with a passage 56 formed in the second rocker arm 19. Moreover, the passage 56 is always in communication with the hydraulic pressure supply passage 57 provided in the rocker shaft 17 via the collar 22 and the sliding metal 21, and the hydraulic pressure supply passage 57 is connected to a hydraulic pressure supply source (not shown).

According to the lock mechanism R ₁ , when the hydraulic pressure is supplied to the hydraulic chamber 52, the lock member 51 projects toward the first rocker arm 18 side against the spring force of the return spring 53, and the lock member 51.
By the tip of the abutment on the first rocker arm 18,
The relative rotation of both rocker arms 18, 19 against the spring force of the torsion springs 20, 20 is prevented.

A control circuit C that detects and operates the operating state of the engine is connected to the solenoid of the electromagnet body 13.
A signal from the switch controls the energization and de-energization of the electromagnet body 13. Further, to the control circuit C, detection signals such as engine speed, temperature, throttle opening and intake air amount are input as signals for detecting the operating state of the engine.

Next, the operation of the first embodiment will be described with reference to FIGS. 5, 6, and 7. When the valve operating cam shaft 14 is rotationally driven by the operation of the engine, the intake cam 15 and the valve The intake valve 5 is driven to open and close at a predetermined timing by the cooperation of the springs 11 and 12. Thus, the valve opening lift amount of the intake valve 5 with respect to the rotation angle of the valve operating cam shaft 14 draws a lift curve as shown by the one-dot chain line in FIG.

By the way, when the engine is in a specific operating state, for example, a low load operating state, as shown in FIG. 1, while the base circle portion of the intake cam 15 is in sliding contact with the first rocker arm 18, that is, the intake valve 5 is in the lift state. Before the above condition, the electromagnet body 13 is energized by the control of the control circuit C to attract the spring retainer 9 to the electromagnet body 13.

Then, when the intake cam 15 rotates, the high-order part of the intake cam 15 comes into sliding contact with the first rocker arm 18,
The first rocker arm 18 is rotated clockwise in FIG. 1, and the rotational force thereof is transmitted via the torsion springs 20 and 20, so that the second rocker arm 19 is also pressed in the clockwise direction in FIG. However, as described above, the electromagnetic actuator A
Since the combined force of the suction force of the valve springs 11 and the spring force of the valve springs 11 and 12 is stronger than the elastic force of the torsion springs 20 and 20, the rotation of the second rocker arm 19 is blocked, as shown in FIG. As described above, the first rocker arm 18 only rotates while twisting the torsion springs 20 and 20. As a result, the adsorption valve 5 is held in its closed position, and the valve opening force of the intake cam 15 is accumulated in the torsion springs 20 and 20.

When the valve operating cam shaft 14 continues its rotation and the rotation angle reaches, for example, in the vicinity of point P in FIG. 5, that is, immediately before the lift amount by the intake cam 15 reaches the maximum, the control circuit C controls the electromagnet body. When the power supply to 13 is cut off, the force for attracting the spring retainer 9 is released. As a result, the valve opening force accumulated in the torsion springs 20 and 20 is suddenly released, and the intake valve 5 is rapidly opened and opened by the elastic force of the torsion springs 20 and 20, as shown in FIG. The valve lift amount increases linearly as shown by the thick solid line in FIG. As a result, the air-fuel mixture flowing through the intake system suddenly flows into the combustion chamber 2.

By the way, if the internal combustion engine is in the intake stroke in which the piston descends and the intake valve 5 is closed as shown in FIG.
Due to the lowering of the piston, the inside of the combustion chamber 2 has a much higher negative pressure than that of the conventional one, and when the intake valve 5 instantaneously opens in this state as shown in FIG. The intake air flowing to 2 is supercharged under a high inertia effect, and the increased intake air is supplied to the combustion chamber 2, so that the supercharging effect in the low load operation state is achieved and the output is improved.

When the holding state is released by the electromagnetic actuator A, the valve piece 32 of the buffer mechanism D ₁ has the large diameter hole 2
When fitted in the lower part of 9, the hydraulic pressure is confined in the hydraulic chamber 34 between the step portions 32a and 30a, so that the downward moving speed of the valve piece 32, that is, the opening speed of the intake valve 5 is alleviated, and the confined hydraulic pressure is reduced. Valve shaft portion 5a and small diameter hole 28
The shocking valve opening operation of the intake valve 5 is alleviated in response to the gradual leakage from the interval.

After the lift amount reaches the maximum, the intake valve 5 is closed by drawing a normal lift curve by the cooperation of the intake cam 15 and the valve springs 11 and 12.

Moreover, in the valve drive means 16, the torsion springs 20, 20
It is possible to reduce the inertial weight by arranging around the rocker shaft 17. In addition, the valve camshaft 1
4 is not arranged immediately above the intake valve 5, and it is possible to avoid an increase in overall height due to the valve camshaft 14 being arranged above the intake valve 5.

Note that the valve opening timing control by the electromagnetic actuator A can be performed at any timing with respect to the valve operating camshaft rotation angle, as shown by the thin solid line in FIG. 5, regardless of the operating state of the engine. That is, it is possible to arbitrarily change the valve opening timing from immediately after the start of the cam lift to the maximum lift, and between the maximum lift and immediately before the end of the cam lift. If the electromagnetic actuator A is continuously energized during the cam lift, the valve rest state can be obtained.

When the engine is in a high load operation state, for example, the energization of the electromagnetic actuator A is cut off and the hydraulic pressure is supplied to the hydraulic chamber 52 of the lock mechanism R ₁ . Then, when the lock member 51 contacts the first rocker arm 18, the relative rotation of both rocker arms 18 and 19 due to the elastic force of the torsion springs 20 and 20 is prevented. Therefore, the valve drive means 16 is connected to the torsion springs 20, 2
Even if 0 is interposed, the second rocker arm 19 can be driven as it is by the first rocker arm 18 while blocking the elastic operation of the torsion springs 20 and 20, and the intake valve 5 can be driven by the cam profile of the intake cam 15 as it is. Can be opened and closed.

FIG. 8 and FIG. 9 show a second embodiment of the present invention, and the portions corresponding to the first embodiment are designated by the same reference numerals.

A lock mechanism R ₂ is provided between the first and second rocker arms 18 and 19. The lock mechanism R ₂ includes a lock member 51 slidably fitted to the second rocker arm 19.
The hydraulic chamber 52 formed facing the back surface of the lock member 51, the return spring 53 that exerts a biasing force in the direction of separating the lock member 51 from the first rocker arm 18, and the tip of the lock member 51 are fitted together. First rocker arm 18
And a fitting recess 58 as a locking portion provided on the.

According to the second embodiment, hydraulic pressure is supplied to the hydraulic chamber 52 to cause the lock member 51 to protrude toward the first rocker arm 18,
By fitting the lock member 51 into the fitting recess 58, the relative rotation of both rocker arms 18 and 19 is blocked. If the lock mechanism R ₂ is operated in this way,
The intake valve 5 can be opened and closed according to the cam profile of the intake cam 5.

FIG. 10, FIG. 11, FIG. 12, FIG. 13, FIG. 14 and FIG. 15 show a third embodiment of the present invention.
The same reference numerals are attached to the parts corresponding to the first embodiment.

A valve drive means 35 is interposed between the intake valve 5 and the intake cam 15, and the valve drive means 35 is rotatably supported by the rocker shaft 17 while slidingly contacting the intake cam 15. A rocker arm 36 as a member, a slide plunger 37 as a second drive member which is slidably supported by the rocker arm 36 while being in contact with the upper end of the valve shaft portion 5a of the intake valve 5, the rocker arm 36 and the slide plunger. 37, and torsion springs 38, 38 as valve-opening elastic members.

The rocker arm 36 is supported on the rocker shaft 17 via a collar 39. Further, the sliding plunger 37 has a basically cylindrical stopper 40 slidably fitted to the rocker arm 36 in order to define the lowermost position of the sliding plunger 37 with respect to the rocker arm 36.
The axial relative position with respect to is variable and screwed, and the lock nut 41 for fixing the position of the stopper 40 is screwed. That is, the rocker arm 36 has
A large-diameter hole 42 and a small-diameter hole 43 are bored in such a manner that they are coaxially connected in order from above, and the stopper 40 has a large-diameter portion 40a and a small-diameter hole 43 slidably fitted in the large-diameter hole 42. A small diameter portion 40b that is slidably fitted is provided. Thus, the step between the large diameter portion 40a and the small diameter portion 40b abuts on the step between the large diameter hole 42 and the small diameter hole 43, whereby the lowest limit position of the stopper 40, that is, the sliding plunger 37 with respect to the rocker arm 36 is defined. To be done.

Moreover, a buffer mechanism D ₂ is provided between the rocker arm 36 and the stopper 40 fixed to the sliding plunger 37. The buffer mechanism D ₂ is a hydraulic chamber defined between the rocker arm 36 and the stopper 40. 44, the hydraulic chamber 44 communicates with a hydraulic supply passage 60 in the rocker shaft 17 via a passage 49 formed in the rocker arm 36. This cushioning mechanism D ₂ includes the stopper 40 and the rocker arm 3
By leaking the oil pressure from the gap between the sliding parts 6, the sliding plunger 37 has a cushioning function when sliding downward.

An arm member 46 is fixed to the lower part of the sliding plunger 37 via a cotter 45. That is, the arm member 46
Is a disc portion 46a and pin-shaped engaging portions 46b and 46b projectingly provided on the disc portion 46a along a diameter line thereof. By pressing the cotter 45 into the wedge hole 47 provided in the center of the slide member 46a, the arm member 46 is slid.
It is fixed at 7.

One ends of the torsion springs 38, 38 are respectively engaged with locking pins 48 fixed to the rocker arm 36 so as to project parallel to the rocker shaft 17, and the other ends thereof are both locking portions of the arm member 46. It is engaged with 46b, 46b.
The torsion springs 38, 38 exert an elastic force in a direction in which the rocker arm 36 is brought into sliding contact with the intake cam 15 and in a direction in which the sliding plunger 37 is brought into contact with the intake valve 5.

A lock mechanism R ₃ is provided between the rocker arm 36 and the sliding plunger 37. The lock mechanism R ₃ engages with an annular locking groove 61 as a locking portion provided on the outer surface of the large diameter portion 40 a of the stopper 40 substantially integral with the sliding plunger 37, and the locking groove 61. And a lock member 62 that has a substantially U-shaped engaging claw 62a at its tip and is arranged to be able to move forward and backward with respect to the rocker arm 36.

The rocker arm 36 is provided with a sliding hole 63 having an axis perpendicular to the axis of the sliding plunger 37. The end of the sliding hole 63 on the side opposite to the sliding plunger 37 is a cap 66. Is blocked. In addition, an operating piston 65 that defines a hydraulic chamber 64 with the cap 66 is slidably fitted in the sliding hole 63, and the engaging claw 62a at the tip is provided.
The base end of the lock member 62 inserted into the slide hole 63 is fixed to the actuating piston 65 so as to be capable of protruding from the open end of the slide hole 63 on the slide plunger 37 side. Further, a return spring 67 surrounding the lock member 62 in the sliding hole 63 is interposed between the working piston 65 and the rocker arm 36,
The return spring 67 biases the operating piston 65, that is, the lock member 62 in a direction in which the volume of the hydraulic chamber 64 contracts.

A passage 68 communicating with the hydraulic chamber 64 is formed in the rocker arm 36, and the passage 68 is formed in the hydraulic supply passage 60.
Independently of, is always communicated with a hydraulic pressure supply passage 69 formed in the rocker shaft 17. Moreover, the hydraulic pressure supply path 69 is
It is connected to a hydraulic pressure supply source (not shown), and the hydraulic pressure from the hydraulic pressure supply source is supplied to the hydraulic pressure chamber 64 so that the operating piston 65 causes the engaging claw 62a at the tip of the lock member 62 to project from the sliding hole 63. Work in the direction.

An annular groove 70 is provided on the outer surface of the intermediate portion of the operating piston 65, and the operating piston 65 moves to a position where the engaging claw 62a at the tip of the lock member 62 protrudes from the sliding hole 63. At a position corresponding to 70, an engaging ball 71 capable of engaging with the annular groove 70 is provided in the middle portion of the sliding hole 63. That is, the engagement ball 71 is movable in the radial direction of the working piston 65 between the position where the engagement groove 71 is engaged with the annular groove 70 and the position where the engagement state is released.
6 is supported, and the passage 6 is provided on the back surface of the engaging ball 71.
The hydraulic pressure of 8 acts.

On the other hand, the stopper 4 which is substantially integrated with the sliding plunger 37
The engaging groove 61 provided at 0 is arranged at a position where the engaging claw 62a of the lock member 62 can be engaged when the sliding plunger 37 relatively moves to the rocker arm 36 to the lowest limit position.

Further, the electromagnetic actuator A is composed of the electromagnet body 13 fixed to the cylinder head 1 and the spring retainer 9, as in the first embodiment.

According to the third embodiment, by energizing the electromagnet body 13 of the electromagnetic actuator A, even when the rocker arm 36 is in sliding contact with the high part of the intake cam 15 as shown in FIG. The intake valve 5 can be held in the closed position by moving the intake valve 5 upward with respect to 36. At this time, the valve opening force accumulated in the torsion springs 38, 38 is released according to the release of the holding state by the electromagnetic actuator A. Then, as shown in FIG. 15, the intake valve 5 can be suddenly actuated to open the intake valve 5 instantaneously, and at this time, the valve opening operation speed can be moderated by the buffer mechanism D _2. .

Further, in the high load operation state of the engine, by supplying hydraulic pressure to the hydraulic chamber 64 of the lock mechanism R ₃ , the lock member 62
The engagement claw 62a at the tip of the lock can be engaged with the annular recess 61, and this state is held by the engagement of the engagement ball 71 with the annular groove 70, so that the rocker arm 36 and the sliding plunger 37 are substantially. Integrally, the intake valve 5 can be opened / closed by surely corresponding to the cam profile of the intake cam 15.

Moreover, in the third embodiment, the portion of the rocker arm 36 supported by the rocker shaft 17 is formed relatively long along the axis of the rocker shaft 17 to reduce the sliding surface pressure between the rocker shaft 17 and the rocker arm 36. be able to. Further, the structure is simple, which is advantageous in terms of workability such as drilling and ensuring accuracy.

FIG. 16 shows a fourth embodiment of the present invention, in which a lock mechanism R ₄ is provided between the rocker arm 36 and the sliding plunger 37.

The lock mechanism R ₄ is a lock nut 4 screwed to the upper end of the sliding plunger 37 to hold the position of the stopper 40.
It is rotatably supported by the rocker arm 36 between a position engaging with 1 '(position shown by a chain line in FIG. 16) and a position releasing its engaged state (position shown by a solid line in FIG. 16). A locking member 73, an operating piston 75 that is arranged on the rocker arm 36 so as to move forward and backward to press the locking member 73 toward the engagement position side, and an operating piston 75 that applies hydraulic pressure to the operating piston 75. A lock member 73 including a hydraulic chamber 76 provided in the rocker arm 36 facing the rear surface is formed in a substantially U-shaped cross section so as to be fitted and engaged with the lock nut 41 ′ from above, and its base end. Is supported on the rocker arm 36 by a support shaft 74 having an axis in a direction orthogonal to the axis of the sliding plunger 37.

On the other hand, the rocker arm 36 is provided with a sliding hole 77 having an axis perpendicular to the axis of the sliding plunger 37, and the end of the sliding hole 77 opposite to the sliding plunger 37 is capped. It is closed at 78. Moreover, sliding hole 7
An operating piston 75 defining a hydraulic chamber 76 is slidably fitted in the inside of the cap 7, and the tip of the operating piston 75 is brought into contact with the rear surface of the base end portion of the lock member 73. . A return spring 79 is provided between the inner surface of the base end portion of the lock member 73 and the rocker arm 36. The return spring 79 is provided in the direction in which the lock member 73 rotates toward the disengagement position, that is, the volume of the hydraulic chamber 76. Urges the working piston 75 in the direction in which the contraction occurs.

The hydraulic chamber 76 is always communicated with the hydraulic pressure supply passage 69 in the rocker shaft 17 through the passage 68 of the rocker arm 36. An annular groove 80 is formed on the outer surface of the intermediate portion of the working piston 75.
Is provided and engages with the annular groove 80 of the piston 75 when the lock member 73 rotates to the engagement position.
Is disposed in the middle of the sliding hole 77, as in the third embodiment.

Also in the fourth embodiment, similarly to the third embodiment, the lock mechanism R ₄ blocks the relative operation of the rocker arm 36 and the sliding plunger 37, and the intake valve 5 is moved to the intake cam 1.
It can be opened and closed along the cam profile of No. 5.

17 to 21 show the fifth embodiment of the present invention, and the portions corresponding to the respective embodiments described above are designated by the same reference numerals.

On the cylinder head 1, a support cylinder 86 extending upward along the axial direction of the intake valve 5 is integrally coupled, and a bearing half portion 87 formed on the support cylinder 86 and fixed to the upper surface thereof. The valve cap cam shaft 14 is rotatably supported by the bearing cap 88. The intake cam 15 provided on the valve operating cam shaft 14 is connected to the intake valve 5 via a valve lifter 90 as a valve driving means.

A hollow cylinder portion 89 that connects the intake cam 15 and the intake valve 5 is formed in the support cylinder 86 of the cylinder head 1, and the valve lifter 90 is provided in the hollow cylinder portion 89.
Is housed. The valve lifter 90 has a bottomed hollow tubular shape and is fitted into a hollow cylinder portion 89 in a vertically slidable manner. The lifter lower portion 91 is a first driving member, and the lifter lower portion 91 is slidable from its open upper portion. A cap-shaped lifter upper portion 92 as a second drive member that is movably fitted, and a valve-opening elastic member that is contracted between the lifter lower portion 91 and the lifter upper portion 92 and biases them so as to extend each other. As 2
It is composed of two lifter springs 93 and 94, and a set nut 95 which is screwed to the open upper part of the lifter lower part 91 and is engaged with the lifter upper part 92 to regulate the upper limit position of the lifter upper part 92.

A projecting pin 96 is integrally provided on the lower portion of the lifter 91 from the central portion of the lower surface thereof, and the lower end of the projecting pin 96 is brought into contact with the upper end of the valve shaft portion 5a of the intake valve 5. The cam surface of the intake cam 15 is in contact with the upper surface of the lifter upper portion 92.
Further, the elastic force of the lifter springs 93, 94 is the valve spring 11,
It is set stronger than that of 12. Therefore, when the valve operating cam shaft 14 rotates, the intake cam 15 pushes the intake valve 5 downward via the valve lifter 90 and can slide the intake valve 5 in the valve opening direction, that is, the downward direction.

The electromagnet body 13 that constitutes the electromagnetic actuator A is fixed to the lower portion of the support cylinder 86 together with the upper surface of the spring retainer 9. Further, a contact portion between the upper end of the valve shaft portion 5a of the intake valve 5 and the protruding pin 96 integral with the lower lifter portion 91 is inserted into the hollow inside of the electromagnet body 13.

The buffer mechanism D is provided between the lifter lower portion 91 and the support cylinder 86.
₃ is provided. The buffer mechanism D ₃ is provided in the lower lifter 91.
Of the annular hydraulic chamber 9 between the outer peripheral surface of the and the inner peripheral wall of the support cylinder 36.
7 is provided, and a support cylinder 86 is provided in the hydraulic chamber 97.
An oil supply port 98 and an oil discharge port 99, which are bored in the hydraulic circuit, are communicated with each other. A hydraulic circuit, for example, a lubricating oil circuit of an engine, is communicated with the hydraulic chamber 97 so that pressure oil circulates in the chamber 97. It has become. The pressure oil that has flowed into the hydraulic chamber 97 acts on the downward pressure-receiving surface 100 formed on the outer peripheral surface of the lifter lower portion 91 to give a cushioning action and a lubricating action to the valve lifter 90 when the valve lifter 90 lifts. It is like this.

A lock mechanism R ₅ is provided between the lifter lower part 91 and the lifter upper part 92 slidably fitted to the lifter lower part 91.

The lock mechanism R ₅ includes a lock member 102 slidably fitted in a bottomed slide hole 101 provided in a central portion of a lifter lower portion 91, and the lock member 102 and a closed end of the slide hole 101. The hydraulic chamber 103 formed between and the lock member 1
02 between the lock member 102 and the lifter upper portion 92 so as to exert a spring force in a direction of contracting the volume of the hydraulic chamber 103 so as to contact the upper end of the lifter 02 so as to project in the center of the lifter upper portion 92. And a return spring 105 inserted in the

The lock member 102 has an oil passage 10 communicating with the hydraulic chamber 103.
6, a lifter lower portion 91 is provided with an oil passage 107 which is in constant communication with the oil passage 106 regardless of the relative movement position with the lock member 102, and the support cylinder 86 is provided in the support cylinder 86.
An oil passage 108 which is always in communication with the oil passage 107 is provided regardless of the vertical position of the oil passage 107.
Is connected to a hydraulic pressure supply source (not shown).

Further, the axial length of the abutment pin 104 is set so that the lock member 102 has a maximum relative movement in a direction in which the lifter lower portion 91 and the lifter upper portion 92 are close to each other in a state where the hydraulic pressure is not supplied to the hydraulic chamber 103. It is set so as not to contact the upper end.

According to the fifth embodiment, if the electromagnetic actuator A holds the closed position of the intake valve 5, the intake valve 5 is closed regardless of the rotational position of the intake cam 15, as shown in FIG. If the valve can be held, and then the valve closed position holding state by the electromagnetic actuator A is released, the intake valve 5 is opened by the spring force of the lifter springs 93 and 94 that has been accumulated, as shown in FIG. Moreover, when the lift amount of the intake valve 5 becomes close to the maximum when the intake valve 5 is opened,
The hydraulic pressure is confined in the hydraulic chamber 97 of the buffer mechanism D _{3, and} the hydraulic pressure leaks from the gap between the lifter lower portion 91 and the support cylinder 86. Therefore, in the region where the energy released by the lifter springs 93 and 94 is large, the valve opening operation of the intake valve 5 is alleviated by the buffering action of the buffering mechanism D ₃ .

When hydraulic pressure is further supplied to the hydraulic chamber 103 of the lock mechanism R ₅ , as shown in FIG. 20, the lock member 102 rises and abuts against the abutment pin 104, so that the lifter upper portion 92 moves downward relative to the lifter lower portion 91. Movement will be blocked. Therefore, as shown in FIG. 21, when the lifter upper portion 92 is pushed down by the intake cam 15, the lifter lower portion 91 is also integrally driven downward, and the intake valve 5 is opened / closed corresponding to the cam profile of the intake cam 15. be able to.

The fifth embodiment can also achieve the same effect as each of the above embodiments.

FIG. 22 shows a sixth embodiment of the present invention, and the portions corresponding to the fifth embodiment are designated by the same reference numerals.

A valve lifter 90 ′ serving as a valve driving means is slidably fitted in a hollow cylinder portion 89 of a support cylinder 86 and a lifter lower portion 91 ′ serving as a first driving member, and slidable in the hollow cylinder portion 89. Lifter upper part 9 as a second driving member to be fitted
2'and a pair of lifter springs 93, 94 interposed between the lifter lower portion 91 'and the lifter upper portion 92',
Locking mechanism R ₆ is interposed between the lifter 'lifter upper 92' bottom 91 and.

The upper end of a projecting pin 96 ′ that abuts the upper end of the intake valve 5 is screwed to the center of the lifter lower portion 91 ′. Further, a cylindrical portion 110 extending upward is coaxially provided on the central upper portion of the lifter lower portion 91 ′ so as to slidably contact the intake cam 15.
The pin 111 protruding from the lower center of the 2'is the cylindrical portion 110.
It is slidably fitted therein. Further, a screw member 114 engageable with a locking step portion 112 provided on the upper end of the cylindrical portion 110 is screwed to the tip of the pin 111. Therefore, the relative movement of the lifter lower portion 91 ′ and the lifter upper portion 92 ′ in the directions away from each other is restricted by the screw member 114 engaging with the locking step portion 112.

The lock mechanism R ₆ has a protruding pin 9 in the cylindrical portion 110.
A hydraulic chamber 113 is formed between the upper end of 6'and the lower end of the pin 111. By supplying hydraulic pressure to the hydraulic chamber 113, the pin 111, that is, the lifter lower part 91 'of the lifter upper part 92'. The relative movement downwards with respect to is blocked.

The oil passage 11 communicating with the hydraulic chamber 113 is connected to the protruding pin 96 '.
5 is provided, and this oil passage 115 is provided in the support cylinder 86 and is always in communication with the oil passage 108.

The sixth embodiment can also achieve the same effect as the fifth embodiment.

In each of the above embodiments, the case where the device of the present invention is applied to the intake valve opening / closing mechanism of the internal combustion engine has been described, but it is also possible to apply this to the exhaust valve opening / closing mechanism, in which case the exhaust gas in the exhaust stroke is used. Due to the rapid opening of the valve, the pressurized exhaust gas flows to the exhaust system all at once, and the exhaust inertia is increased to improve the exhaust efficiency, whereby the output can be improved.

C. As described above, according to the present invention, the valve drive means includes the valve-opening elastic member that exerts an elastic force in the valve-opening direction of the engine valve, and is provided between the engine valve and the valve operating cam. Holding means for holding the engine valve in the closed position while accumulating the valve opening force by the valve operating cam in the valve opening elastic member, and the holding means is provided for the engine valve according to the operating state of the engine. The holding state and the holding release state can be switched to control the valve opening timing, and the valve driving means is provided with a lock mechanism capable of blocking the elastic operation of the valve opening elastic member. By controlling the release timing, the optimum valve opening timing can be set according to the operating condition of the engine, the intake and exhaust inertia effects can be enhanced to improve the intake efficiency or exhaust efficiency, and the lock mechanism works to open the valve. Preventing the elastic action of the valve elastic member to operate the engine valve It is also possible to open and close the cam according to the profile of the cam.

[Brief description of drawings]

1 to 7 show a first embodiment of the present invention. FIG. 1 is a vertical side view, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. FIG. 3 is an enlarged view of part III in FIG. 4, FIG. 4 is a longitudinal sectional view of a main part for showing the lock mechanism attached to the valve driving means, and FIG. 5 shows the relationship between the valve opening lift amount and the rotation angle of the valve operating cam. 6 is a vertical sectional side view corresponding to FIG. 1 showing a valve closed position holding state by the holding means, and FIG. 7 is a vertical sectional side view corresponding to FIG. 1 showing a holding released state by the holding means. 8 and 9 show a second embodiment of the present invention. FIG. 8 is a longitudinal sectional view of an essential part corresponding to FIG. 4, FIG. 9 is a view taken along the line IX-IX of FIG. 10 to 15 show a third embodiment of the present invention. FIG. 10 is a vertical side view, FIG. 11 is a view taken along line XI-XI of FIG. 10, and FIG. XII-XII sectional view of the figure 13 is a sectional view taken along the line XIII-XIII in FIG. 11 for showing the locking mechanism, FIG. 14 is a vertical sectional side view corresponding to FIG. 10 showing a valve closing position holding state by the holding means, and FIG. FIG. 16 is a vertical sectional view corresponding to FIG. 10 showing a holding release state by means, FIG. 16 is a longitudinal sectional side view of an essential part corresponding to FIG. 13 of the fourth embodiment of the present invention,
17 to 21 show a fifth embodiment of the present invention. FIG. 17 is a vertical sectional side view in a valve closed state, and FIG. 18 is a vertical sectional side view showing a valve closed position holding state by a holding means. FIG. 19 is a vertical cross-sectional side view when the valve holding position is released by the holding means, FIG. 20 is a vertical cross-sectional side view corresponding to FIG. 17 when the lock mechanism is activated, and FIG. 21 is FIG. 19 when the lock mechanism is activated. FIG. 22 is a vertical cross-sectional side view of the sixth embodiment of the present invention when the lock mechanism is operated. 5 ... intake valves as engine valves, 11, 12 ... valve springs, 15
... intake cam as valve actuating cam, 16, 35 ... valve driving means, 18 ... first rocker arm, 19 ... second rocker arm, 20, 38 ... torsion spring as elastic member for valve opening,
36 ... Rocker arm as first driving member, 37 ... Second
Sliding plungers as driving members, 52, 76, 10
3, 113 ... Hydraulic chamber, 56, 75 ... Working piston, 61
... Locking grooves as locking parts, 62, 73 ... Lock members, 9
0, 90 '... Valve lifters as valve driving means, 91, 9
1 '... lower part of lifter as first driving member, 92, 92'
... lifter upper portion of the second driving member, 93, 94 ... lifter spring as an elastic member for the valve opening, A ... electromagnetic actuator as the holding means, E ... engine body, R 1 _{to R} 6 _... locking mechanism

Claims (9)

[Claims] Claim: What is claimed is: 1. An engine valve that is openably and closably supported by an engine body, a valve spring that biases the engine valve in a valve closing direction, and a valve cam that operates to transmit a force in a valve opening direction to the engine valve. In a valve drive control device for an internal combustion engine, comprising a valve cam and a valve drive means interposed between the engine valves, the valve drive means includes a valve opening elastic member that exerts elastic force in a valve opening direction of the engine valve. A holding means is provided between the engine valve and the valve operating cam for holding the engine valve in the valve closing position while accumulating the valve opening force of the valve operating cam in the valve opening elastic member. The means is configured to be switchable between a holding state and a holding release state so as to control the valve opening timing of the engine valve according to the operating state of the engine, and the valve driving means can prevent the elastic operation of the valve opening elastic member. A valve operating control device for an internal combustion engine, wherein a lock mechanism is additionally provided. 2. The valve drive means comprises first and second drive members which are relatively displaceable, and a valve opening elastic member interposed between the both drive members, and the lock mechanism is a valve opening elastic member. Paragraph (1), characterized in that it has a hydraulic chamber capable of exerting hydraulic pressure in a direction to prevent relative displacement of both drive members against the elastic force of, and is interposed between both drive members. A valve train control device for an internal combustion engine as described above. 3. A lock mechanism between a first rocker arm on the valve cam side as a first drive member and a second rocker arm as a second drive member swingable around an axis common to the first rocker arm. No. (2), characterized in that
Item 10. A valve control device for an internal combustion engine according to item. 4. A lock mechanism is provided between an engine valve side lifter lower portion serving as a first drive member and a valve actuating cam side lifter upper portion serving as a second drive member capable of relative movement with respect to the lifter lower portion. The valve operation control device for an internal combustion engine according to the item (2), which is installed. 5. The valve drive means includes first and second drive members capable of relative displacement, and a valve opening elastic member interposed between the drive members, and the lock mechanism includes the first and second drive members. The lock member engageable with one of the drive members is arranged to be operable between an engagement position and an engagement release position and arranged on the other drive member, (1) Valve control device for internal combustion engine. 6. A lock mechanism includes a first rocker arm on the valve cam side as a first drive member, and a locking portion provided on one of second rocker arms swingable around an axis common to the first rocker arm, A lock member disposed on the other of the first and second rocker arms so as to be movable back and forth between a position for engaging the locking portion and a position for releasing the engagement state. A valve control device for an internal combustion engine according to the item (5). 7. The valve drive means includes a rocker arm as a first drive member that is in sliding contact with a valve cam and a sliding plunger as a second drive member that is slidably supported by the rocker arm so as to abut an engine valve. A locking mechanism provided between the rocker arm and the sliding plunger, the locking mechanism being provided on the sliding plunger, a position at which the locking mechanism is engaged, and an engagement state thereof. The valve operating control device for the internal combustion engine according to item (5), further comprising: a lock member that is provided to the rocker arm so as to be capable of advancing and retracting between the locker arm and the position where the lock is released. 8. The valve drive means comprises a rocker arm as a first drive member that is in sliding contact with a valve cam, and a sliding plunger as a second drive member that is slidably supported by the rocker arm so as to contact the engine valve. , A valve opening elastic member interposed between the rocker arm and the sliding plunger, and the locking mechanism is rotatable between a position for engaging the sliding plunger and a position for releasing the engagement state. A lock member supported by the rocker arm, a working piston provided on the rocker arm so as to be able to move forward and backward so as to press the lock member in the direction of engaging the sliding plunger, and a hydraulic pressure to act on the working piston. A hydraulic chamber provided on the rocker arm facing the back surface of the working piston;
A valve control device for an internal combustion engine according to the item (5). 9. The valve operating system for an internal combustion engine according to claim 1, wherein the holding means is an electromagnetic actuator.