JPH076373B2 - Valve drive controller for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of Industrial Application The present invention relates to 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, an intake valve or an exhaust valve as an engine valve is controlled to be opened / closed by the cooperation of a valve cam and a valve spring, and also by the operation of an 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 present applicant proposes, in the engine valve opening / closing control device, a device for improving the performance of the engine by maximally utilizing the attractive force of the electromagnetic actuator ( Japanese Patent Application Sho 62-
No. 123647), but with this one, the valve is opened by exciting the electromagnetic actuator and is closed at once by the spring force due to its demagnetization, so the valve closing timing can be controlled by inertial supercharging effectively. There is a problem that variable control of the valve opening timing that can be used is not possible.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a valve operating control device for an internal combustion engine capable of controlling the opening timing and closing timing of an engine valve with a simple configuration. To do.

B. Configuration of the Invention (1) Means for Solving the Problems According to the present invention in order to achieve the above object, an engine that is supported by an engine body and can reciprocate between a predetermined valve opening position and a predetermined valve closing position. A valve and a valve spring for urging the engine valve in a closing direction,
In a valve drive control device for an internal combustion engine, comprising a valve drive cam and valve drive means interposed between the engine valve and the valve cam to transmit a force in the valve opening direction by the valve cam to the engine valve, the valve drive means is , An elastic member for valve opening that can exert an elastic force larger than the elastic force of the valve spring in the valve opening direction of the engine valve and transmit the force in the valve opening direction by the valve operating cam to the engine valve side, Between the valve and the valve operating cam, there is provided a first holding means capable of 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, and the engine valve opening position. A second holding means capable of holding the first holding means, and the first holding means is configured to be able to switch between a holding state and a holding release state to control the opening timing of the engine valve according to the operating state of the engine, The second holding means sets a holding state and a holding release state to control the closing timing of the engine valve according to the operating state of the engine. Conversion can be configured.

(2) Action In the operating state of the engine (that is, the rotating state of the valve cam),
When the first holding means is switched to the holding state, the engine valve can be held at the valve closing position regardless of the rotational position of the valve operating cam, and the cam is opened by the cam depending on the rotation of the valve operating cam. Since the valve force can be accumulated in the valve-opening elastic member, the engine valve can be rapidly opened by the elastic force of the valve-opening elastic member when the holding state by the first holding means is released in this pressure-accumulated state. it can. According to such switching control of the first holding means, the engine valve deviates from the valve opening lift curve defined by the cam profile of the valve operating cam, the valve opening start timing is delayed, and the valve opening operation speed is Is set to a rapid speed, therefore, if such a valve opening control is performed in a low load operating state of the engine, for example, it is possible to enhance the intake and exhaust inertial effects in the same operating state and enhance the intake and exhaust efficiency. It is possible.

On the other hand, when the second holding means is switched to the holding state, the engine valve can be held at the valve opening position regardless of the rotational position of the valve operating cam, and then the holding state by the second holding means is released. At this time, the engine valve can be rapidly closed by the elastic force of the valve spring. According to such switching control of the second holding means, the engine valve deviates from the valve closing lift curve defined by the cam profile of the valve operating cam so that the valve closing start timing is delayed and the valve closing operating speed is increased. Is set to a rapid speed, for example, if such valve closing control is performed after the valve opening control, the intake and exhaust gas inertial effects described above can be effectively maintained for as long a period as possible. It is possible to further improve the exhaust efficiency.

(3) Example Hereinafter, an example 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 is The valve seat 7 at the open end of the intake port 3 on the combustion chamber 2 side can be seated 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. A valve spring 11 composed of a compression coil spring is contracted between the spring retainer 9 and a spring seat 10 formed in the cylinder head 1 so as to face the spring retainer 9, and the elastic force of the valve spring 11 is the intake valve. 5 is urged in the valve closing direction. Thus, the spring retainer 9 is made of a magnetic material, and constitutes a first electromagnetic actuator A ₁ as a first holding means together with an electromagnet body 13 which will be described later.
Together with 34, a second electromagnetic actuator A ₂ as a second holding means is configured.

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

Referring also to FIG. 2, the valve driving means 16 includes a rocker shaft 17 fixedly arranged in parallel above the valve operating cam shaft 14 between the valve operating cam shaft 14 and the intake valve 5, and an intake cam 15.
The first rocker arm 18 supported by the rocker shaft 17 so as to be slidably contacted with the rocker shaft 17, the second rocker arm 19 supported by the rocker shaft 17 so as to rock while abutting on the upper end of the intake valve 5, and both rocker arms 18. Intake valve 5 installed between
And torsion springs 20, 20 as elastic members for opening the valve, which exert a spring force in the valve opening direction.

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. Drum parts 22a, 22a for winding the torsion springs 20, 20 are provided at both ends of the collar 22 in the axial direction, and a part near the axial center part of the collar 22, that is, between both drum parts 22a, 22a. The base ends of the first and second rocker arms 18 and 19 are rotatably supported.

The first rocker arm 18 moves from the rocker shaft 17 to the intake cam 15
The cam surface of the intake cam 15 is in sliding contact with the lower surface of the front end portion of the first rocker arm 18. The second rocker arm 19 extends from the rocker shaft 17 to the intake valve 5 side while the base portion of the second rocker arm 19 is in sliding contact with the base portion of the first rocker arm 18. The tip of the second rocker arm 19 has a tappet screw that abuts the upper end of the valve shaft portion 5a of the intake valve 5.
24 is screwed so that it can move forward and backward. Moreover, the tappet screw 24 has a second rocker arm for holding the adjusted forward / backward position.
A lock nut 25 that comes into contact with the upper surface of the tip end portion of 19 is screwed.

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. One end of each of the torsion springs 20 and 20 is engaged with the locking pin 26 of the first rocker arm 18, and the other end is the second pin.
The locking pins 27 of the rocker arm 19 are engaged with each other. As a result, the first and second rocker arms 18, 19 move the first rocker arm 18 to the intake cam 15 side, and the second rocker arm 18 and 19.
19 is urged in the direction of rotating the intake valve 5. Moreover, the resilience of both torsion springs 20 and 20 is set stronger than that of the valve springs 11 and 12. Therefore, when the valve operating cam shaft 14 rotates, the intake cam 15 pushes the intake valve 5 downward via the valve driving means 16 and can slide the intake valve 5 in the valve opening direction, that is, the downward direction.

Referring also to FIG. 3, the cylinder head 1 has a valve shaft portion of the intake valve 5 that faces the upper surface of the spring retainer 9.
An annular electromagnet body 13 that surrounds 5a is fixed, and this electromagnet body 13 together with the magnetic body 9 that also functions as the spring retainer
Configure electromagnetic actuator A ₁ . Further, the electromagnet body 13 has a through hole 30 in which a small diameter hole 28 slidably contacting the valve shaft portion 5a of the intake valve 5 and a large diameter hole 29 having a diameter larger than the small diameter hole 28 are coaxially connected in order from below. The valve shaft portion of the intake valve 5 that is drilled
5a is inserted into the through hole 30 so as to be movable in the axial direction.

By exciting the solenoid in the electromagnet body 13, the magnetic body 9 is attracted to the electromagnet body 13. The attraction force of the first electromagnetic actuator A ₁ and the spring force of the valve spring 11 are set to be stronger than the elastic force of the torsion springs 20, 20 in the valve driving means 16. 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 the torsion spring 2
The pressure will be accumulated at 0,20.

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 of the electromagnet body 13. A cap-shaped valve piece 32 slidably fitted in the large diameter hole 29 of the through hole 30 is fitted to the upper end of the valve shaft portion 5a which is inserted into the through hole 30. Moreover, 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, and the tappet screw 24 is It contacts the valve piece 32. Further electromagnet body 13
An oil supply hole 33 communicating with the annular recess 31 of the through hole 30 is bored therethrough, and an oil supply source (not shown) is connected to the oil supply hole 33.

On the other hand, an annular electromagnet body 34, which faces the lower surface of the spring retainer 9 and surrounds the valve shaft portion 5a of the intake valve 5, is fixed to the cylinder head 1, and the electromagnet body 34 also serves as the magnetic body 9 which also functions as the spring retainer. With the second electromagnetic actuator
Make up A ₂ . The magnetic body 9 is attracted to the electromagnet body 34 by the excitation of the solenoid in the electromagnet body 34. This second
The attraction force of the electromagnetic actuator A ₂ is set to be stronger than the spring force of the valve spring 11. Therefore, when the electromagnet body 34 is excited when the intake valve 5 is opened, the intake valve 5 is held in its open position regardless of the rotation of the valve operating camshaft 14.

A control circuit C that detects and operates the operating state of the engine is connected to the solenoid of the electromagnet body 13 and the solenoid of the electromagnet body 34, and a signal from the control circuit C causes the electromagnet body to operate.
The power supply to and the power supply to the electromagnet body 34 are cut off. 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. 4, 5, and 6. 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 with the spring 11. 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 magnetic body 9 to the electromagnet body 13.

Then, when the intake cam 15 is rotated to bring the high-level portion of the intake cam 15 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 the torsion spring 20, Although it is transmitted via 20 and the pressing force in the clockwise direction in FIG. 1 also acts on the second rocker arm 19, as described above, the spring force of the first electromagnetic actuator A ₁ and the valve spring 11 is the torsion spring 20, Since it is stronger than the elastic force of 20, the rotation of the second rocker arm 19 is blocked,
While twisting the torsion springs 20, 20,
The rocker arm 18 only rotates. As a result, the intake 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, 20.

When the valve operating cam shaft 14 continues to rotate and the rotation angle reaches, for example, in the vicinity of point P in FIG. 4, that is, just 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 to attract the magnetic body 9 is released. As a result, the valve opening force accumulated in the torsion springs 20,20 is suddenly released, and the intake valve 5 is suddenly opened and opened by the elastic force of the torsion springs 20,20 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.

Moreover, when the holding state is released by the first electromagnetic actuator A ₁ , the valve piece 32 attached to the valve shaft portion 5a of the intake valve 5 is
Is slid downward in the through hole 30 of the electromagnet body 13, but when the valve piece 32 is fitted in the lower part of the large diameter hole 29, the lower surface of the valve piece 32 and the small diameter hole 28 and the large diameter hole 29 are Since the hydraulic pressure is confined between the steps of the valve, the downward moving speed of the valve piece 32, that is, the opening speed of the intake valve 5 is moderated, and the confined hydraulic pressure gradually leaks from between the valve piece 32 and the small diameter hole 28. In response to this, the intake valve 5 is gently opened, and a rapid buffering of the opening speed is achieved.

When the lift amount of the intake valve 5 becomes maximum, the control circuit C
Is controlled so that the magnetic body 9 is electrified by energizing the electromagnet body 34.
Adsorb to 34. As a result, the second electromagnetic actuator A ₂
Is activated and the intake valve 5 is held in its open position, and the intake valve 5 remains open regardless of the rotational position of the intake cam 15. When the electromagnet body 34 is demagnetized, the intake cam 5 is closed by the spring force of the valve spring 11 regardless of the cam profile, as shown by the thick solid line in FIG. After coming into contact with the tappet screw 24 of the drive means 16, the intake cam 15 is closed by drawing a normal lift curve by the cooperation of the valve spring 11.

In this way, the opening timing and closing timing of the intake valve 5 are
By controlling the holding state and holding release state of the first and second electromagnetic actuators A ₁ and A ₂ , it can be arbitrarily set, and appropriate valve actuation control can be performed according to the operating state of the engine. .

Moreover, by disposing the torsion springs 20, 20 around the rocker shaft 17 in the valve drive means 16, the inertial weight can be reduced. Further, since the valve operating cam shaft 14 is not arranged immediately above the intake valve 5, it is possible to avoid an increase in overall height due to the valve operating cam shaft 14 being disposed above the intake valve 5.

The holding action by the first and second electromagnetic actuators A ₁ and A ₂ can be performed at any timing as shown by the thin solid line in FIG. 4 regardless of the operating state of the engine.
That is, both electromagnetic actuators A ₁ and A ₂ can arbitrarily change the valve opening and closing timings immediately after the start of the cam lift to the maximum lift, and between the maximum lift and the end of the cam lift. Also, if the electromagnetic actuators A ₁ and A ₂ are always de-energized, the opening / closing timing almost along the cam profile can be obtained, and if the relative rotation of both rocker arms 18 and 19 is prevented, the cam profile can be prevented. The opening / closing timing can be reliably obtained. Moreover, the valve resting state can be obtained by continuing to energize the first electromagnetic actuator A ₁ during the cam lift.

FIG. 7, 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 support cylinder 36 extending obliquely upward along the axial direction of the intake valve 5 is integrally formed on the cylinder head 1, and a bearing half portion 37 formed on the support cylinder 36 and fixed to the upper surface thereof. The valve cam shaft 14 is rotatably supported by the bearing cap 38. Intake cam 15 provided on valve cam shaft 14
Is connected to the intake valve 5 via a valve lifter 40 as a valve driving means described later.

The intake cam is provided in the support cylinder 36 of the cylinder head 1.
A hollow cylinder portion 39 is formed that connects the intake valve 5 and the intake valve 5, and the valve lifter 40 is accommodated in the hollow cylinder portion 39. The valve lifter 40 has a bottomed hollow tubular shape and is fitted into a hollow cylinder portion 39 so as to be vertically slidable.
And a cap-shaped lifter upper part 42 slidably fitted to the lifter lower part 41 from its open upper part, and contracted between the lifter lower part 41 and the lifter upper part 42 and urged to extend them. Two lifter springs 43, 44 as elastic members for opening the valve, and a set nut 45 screwed to the open upper part of the lifter lower part 41 and engaged therewith to restrict the upper limit position of the lifter upper part 42. It is configured.

On the lower part 41 of the lifter, a projecting pin 46
And the lower end of the protruding pin 46 abuts on the upper end of the valve shaft portion 5a of the intake valve 5. The cam surface of the intake cam 15 is brought into contact with the upper surface of the lifter upper portion 42. Further, the resilience of the lifter springs 43, 44 is set to be stronger than that of the valve spring 11. Therefore, when the valve operating cam shaft 14 rotates, the intake cam 15 pushes the intake valve 5 downward via the valve lifter 40 and can slide it in the valve opening direction, that is, the downward direction.

At the bottom of the support cylinder 36, together with the upper surface of the spring retainer 9, the first
The electromagnet body 13 constituting the electromagnetic actuator A ₁ is fixed, and the electromagnet body 34 constituting the second electromagnetic actuator A ₂ is fixed to the cylinder head 1 together with the lower surface of the spring retainer 9 as in the first embodiment. It is the same. Further, inside the hollow of the electromagnet body 13, a contact portion between the upper end of the valve shaft portion 5a of the intake valve 5 and the protruding pin 46 integral with the lower lifter portion 42 is inserted. Further, the attraction force of the first electromagnetic actuator A ₁ and the spring force of the valve spring 11 are set to be stronger than the resilient force of the lifter springs 43 and 44, and the attraction force of the second electromagnetic actuator A ₂ is set to the valve spring 11. It is set stronger than the spring force.

Outer peripheral surface of the lifter lower portion 41 and the support cylinder in the valve lifter 40.
An annular hydraulic chamber 47 is formed between the inner peripheral wall of 36 and the hydraulic chamber 47. In the hydraulic chamber 47, an oil supply port 48 and an oil discharge port 49 formed in the support cylinder 36 are formed.
And a hydraulic circuit, for example, a lubricating oil circuit of an engine, communicates with the hydraulic chamber 47 so that the pressurized oil circulates in the chamber 47. The pressure oil that has flowed into the hydraulic chamber 47 acts on the downward pressure receiving surface 50 formed on the outer peripheral surface of the lifter lower portion 41 to provide a buffering action and a lubricating action to the valve lifter 40 when the valve lifter 40 lifts. It is like this.

According to this second embodiment, the closed position of the intake valve 5 is maintained by the first electromagnetic actuator A ₁ , and the intake valve 5 is closed regardless of the rotational position of the intake cam 15 as shown in FIG. Second electromagnetic actuator that can be held in a valve state
Due to A ₂ , the intake valve 5 can be maintained in the open state as shown in FIG. 9, and the same effect as that of the first embodiment can be obtained.

FIG. 10, FIG. 11 and FIG. 12 show the third embodiment of the present invention, and the portions corresponding to the respective embodiments are designated by the same reference numerals.

A valve drive means 55 is interposed between the intake valve 5 and the intake cam 15, and the valve drive means 55 is rotatably supported on the rocker shaft 17 because it does not slide on the intake cam 15.
56, a sliding plunger 57 slidably supported by the rocker arm 56 while contacting the upper end of the valve shaft portion 5a of the intake valve 5, and a valve opening provided between the rocker arm 56 and the sliding plunger 57. And torsion springs 58, 58 as elastic members.

The rocker arm 56 is supported on the rocker shaft 17 via the collar 59. Further, the sliding plunger 57 is provided with a basically cylindrical stopper 60 slidably fitted to the rocker arm 56 in order to define the lowermost position of the sliding plunger 57 with respect to the rocker arm 56. It can be screwed with its direction relative position variable, and its stopper 60
A lock nut 61 for fixing the position is screwed. That is, the rocker arm 56 has a hole in which the large diameter hole 62 and the small diameter hole 63 are coaxially connected in order from the upper side, and
The 60 has a large diameter portion 60a slidably fitted in the large diameter hole 62 and a small diameter portion 60b slidably fitted in the small diameter hole 63. Thus, the step between the large diameter portion 60a and the small diameter portion 60b is a large diameter hole.
By contacting the stepped portion between the 62 and the small diameter hole 63, the lowermost limit position of the stopper 60, that is, the sliding plunger 57 with respect to the rocker arm 56 is defined. Moreover, by supplying hydraulic pressure to the annular chamber 64 defined between the rocker arm 56 and the stopper 60, the buffering action when the sliding plunger 57 slides downward is achieved.

An arm member 66 is fixed to the lower part of the sliding plunger 57 via a cotter 65. That is, the arm member 66 is a disc portion.
66a and pin-shaped locking portions 66b, 66b projectingly provided on the disc portion 66a along the one diameter line thereof, and are formed in the central portion of the disc portion 66a so that the diameter becomes smaller toward the upper side. By pressing the cotter 65 into the provided wedge hole 67, the arm member
66 is fixed to the sliding plunger 57.

One ends of the torsion springs 58, 58 are respectively engaged with locking pins 68 fixed to the rocker arm 56 so as to project parallel to the rocker shaft 17 and to the both sides, and the other end is provided with an arm member 66.
Are engaged with both locking portions 66b, 66b. The torsion springs 58, 58 exert an elastic force in a direction in which the rocker arm 56 is brought into sliding contact with the intake cam 15 and in a direction in which the sliding plunger 57 is brought into contact with the intake valve 5.

The other configurations are similar to those of the first and second embodiments. The upper surface of the spring retainer 9 and the electromagnet body 13 constitute the first electromagnetic actuator A ₁ , and the lower surface of the spring retainer 9 and the electromagnet body 13 are the same. The second electromagnetic actuator A ₂ is constituted by 34, and the attraction force of the first electromagnetic actuator A ₁ and the spring force of the valve spring 11 are set to be larger than the elastic force of the torsion springs 58, 58. The attraction force of A ₂ is set to be larger than the spring force of the valve spring 11.

According to the third embodiment, by energizing the electromagnet body 13 of the first electromagnetic actuator A ₁ , the intake valve 5 can be held in the closed state, and the timing for releasing the held state can be controlled. Can control the opening timing of the intake valve 5, and the second electromagnetic actuator A ₂ can control the intake valve 5
The valve open state can be maintained, and the valve close timing of the intake valve 5 can be controlled by controlling the timing of releasing the valve hold state. Therefore, the same effect as each of the above embodiments can be obtained. it can.

As still another embodiment of the present invention, the rocker arm in the embodiment shown in FIGS. 10 to 12 is brought into contact with the intake cam, and the sliding plunger supported by the rocker arm is brought into contact with the intake cam. Good.

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.

C. Effects of the Invention As described above, according to the present invention, in the operating state of the engine, in the state where the first holding means is switched to the holding state and the engine valve is held at the valve closing position, the valve opening force by the valve operating cam is increased. Is stored in the valve-opening elastic member, and when the holding state by the first holding means is released in this pressure-stored state, the engine valve can be rapidly opened by the elastic force of the valve-opening elastic member. As a result of such switching control of the first holding means, the engine valve deviates from the valve opening lift curve defined by the cam profile of the valve operating cam so that the valve opening start timing is delayed and the valve opening speed is increased. It becomes possible to set to a rapid speed, which makes it possible to enhance the intake and exhaust inertial effects and enhance the intake and exhaust efficiency.

On the other hand, when the second holding means is switched to the holding state and the engine valve is held at the open position, and the second holding means is switched to the holding release state at any time, the engine valve is rapidly closed by the elastic force of the valve spring. Since the valve operation can be performed, the engine valve deviates from the valve closing lift curve defined by the cam profile of the valve operating cam by the switching control of the second holding means, and the valve closing start timing is delayed. In addition, the valve closing operation speed can be set to a rapid speed, and if the valve closing control is performed after the valve opening control, the intake and exhaust gas inertial effects described above can be effectively maintained for as long as possible. As a result, the efficiency of intake and exhaust can be further improved.

Also, especially when each holding means, when it is in the holding state,
This control is relatively easy because the engine valve need only be held and fixed in the fixed position (that is, the valve opening position or valve closing position), and the holding state can be switched on and off from the holding state. Since the engine valve is rapidly opened or closed, the valve opening or closing timing can be accurately defined and the operation of the engine valve can be stabilized.

[Brief description of drawings]

1 to 6 show a first embodiment of the present invention. FIG. 1 is a vertical sectional side view, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. FIG. 4 is an enlarged view of a part III of FIG. 4, and FIG.
FIG. 6 is a vertical sectional side view corresponding to FIG. 1 showing a valve closed position holding state by the first holding means, and FIG. 6 is a vertical sectional side view corresponding to FIG. 1 showing a valve open position holding state by the second holding means. 7 to 9 show a second embodiment of the present invention. FIG. 7 corresponds to a vertical side view, and FIG. 8 corresponds to FIG. 7 showing a valve closed position holding state by the first holding means. Vertical side view,
FIG. 9 is a vertical sectional side view corresponding to FIG. 7 showing the valve opening position holding means by the second holding means, and FIGS. 10 to 12 show a third embodiment of the present invention. Is a vertical side view, FIG. 11 is a plan view of FIG. 10, and FIG. 12 is XII-X of FIG.
It is a II sectional view. 5 ... intake valve as engine valve, 11 ... valve spring, 15 ... intake cam as valve cam, 16,55 ... valve driving means, 18 ...
… First rocker arm, 19 …… Second rocker arm, 20,58
...... Torsion spring as valve-opening elastic member, 40 …… Valve lifter as valve driving means, 41 …… Lower lifter, 42 …… Lifter upper part, 43,44 …… Lifter spring as valve-opening elastic member, 56 ...... rocker arm, 57 ...... sliding plunger, a ₁ ...... first electromagnetic actuator as a first holding means,
A ₂ ... A _second electromagnetic actuator as a second holding means,
E: Engine body

Claims (5)

[Claims] 1. An engine valve (5) which is supported by an engine body (E) and can reciprocate between a predetermined valve opening position and a predetermined valve closing position, and biases the engine valve (5) in a valve closing direction. Valve spring (11) and valve driving means interposed between the valve cam (15) and the engine valve (5) for transmitting the force in the valve opening direction by the valve cam (15) to the engine valve (5). (16; 40; 55), and a valve drive means (16; 40; 55) is provided with an elastic force larger than the elastic force of the valve spring (11). Elastic member (20; 43,44; 58 for valve opening that can exert the force in the valve opening direction of the engine valve (5) to transmit the force in the valve opening direction by the valve operating cam (15) to the engine valve (5) side. ),
Between the engine valve (5) and the valve operating cam (15), the valve opening force of the valve operating cam (15) is applied to the elastic member (20; 43,44; 58) for valve opening.
A _first holding means (A ₁ ) capable of holding the engine valve (5) in the valve closing position while accumulating pressure in the second and a second holding means (A ₂ ) capable of holding the engine valve (5) in the valve opening position. And the first holding means (A ₁ ) is provided with an engine valve (5) according to the operating state of the engine.
Is configured to be switchable between a holding state and a holding release state to control the valve opening timing of the engine. The second holding means (A ₂ ) controls the closing timing of the engine valve (5) according to the operating state of the engine. Accordingly, a valve operating control device for an internal combustion engine, which is configured to be switchable between a holding state and a holding release state. 2. A valve operating control system for an internal combustion engine according to claim 1, wherein at least one of the first and second holding means comprises an electromagnetic actuator (A ₁ , A ₂ ). 3. A valve drive means (16), a first rocker arm (18) on the valve cam (15) side, and an engine valve (5) swingable around an axis common to the first rocker arm (18). The valve operating control system for the internal combustion engine according to claim 1, characterized in that an elastic member (20) for valve opening is interposed between the second rocker arm (19) on the side. 4. A valve drive means (40) is provided on a lifter upper portion (42) on the valve cam (15) side and on an engine valve (5) side slidably fitted on the lifter upper portion (42). The valve operating control device for an internal combustion engine according to claim 4, wherein a valve opening elastic member (43, 44) is interposed between the lifter lower part (41) and the lifter lower part (41). 5. A valve drive means (55) slidably fits on a valve cam (15) and a rocker arm (56) and slidably fitted on the rocker arm (56) to come into contact with an engine valve (5). The valve operating control device for an internal combustion engine according to claim 4, wherein a valve opening elastic member (58) is interposed between the sliding plunger (57).