JPH0658048B2 - 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 this proposal, when the holding state by the holding means is released, the elastic force of the valve-opening elastic member may cause the engine valve to open suddenly and damage the engine valve and other members.

The present invention has been made in view of the above circumstances, and makes it possible to effectively utilize inertia supercharging by controlling the opening timing of an engine valve, and at the same time, to make the operation of the engine valve gentle when the internal combustion engine is opened. It is an object of the present invention to provide a valve control device of the above.

B. Configuration of the Invention (1) Means for Solving the Problem The present invention provides that the valve drive means includes a valve-opening elastic member that exerts elastic force in the valve-opening direction of the engine valve. A holding means for holding the engine valve in the valve closing position while accumulating the valve opening force by the valve operating cam in the valve opening elastic member is interposed between the two. It is configured to be able to switch between a holding state and a holding release state in order to control the valve opening timing of the engine valve, and the valve driving means is a buffer for relaxing the valve opening operation of the valve driving means by the elastic force of the valve opening elastic member. It is characterized in that a mechanism is attached.

Further, according to the present invention, the valve driving means includes a valve opening elastic member that exerts an elastic force in a valve opening direction of the engine valve, and the valve opening force by the valve operating cam is provided between the engine valve and the valve operating cam. Holding means for holding the engine valve in the closed position while accumulating pressure in the valve opening elastic member, the holding means holds the valve opening timing of the engine valve according to the operating state of the engine. Between the engine valve and an interlocking member that is integrally connected to the engine valve and a fixed guide member that guides the operation of the engine valve or the interlocking member. Another feature is that a cushioning mechanism for reducing the valve opening operation of the engine valve by the elastic force of the elastic member is attached.

(2) Action According to the above feature, the engine valve can be held at the closed position by the holding means regardless of the operating state of the engine, regardless of the opening / closing operation of the engine valve by the valve cam and the valve spring, In the valve closed state, the valve opening force can be accumulated in the valve opening elastic member. Moreover, when the holding state by the holding means is released, the engine valve tries to open suddenly, but the sudden opening operation is alleviated by the action of the buffer mechanism attached to the valve drive means.

Further, according to the above-mentioned other feature, regardless of the operating state of the engine, it is possible to hold the engine valve in the closed position by the holding means regardless of the opening / closing operation of the engine valve by the valve cam and the valve spring. In the valve closed state, the valve opening force can be accumulated in the valve opening elastic member. Moreover, when the holding state by the holding means is released, the engine valve tries to open rapidly, but the sudden valve opening operation is alleviated by the function of the buffer mechanism between the engine valve or the interlocking member and the guide member.

(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 operating cam shaft 14 which 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 springs 20 and 2 in the valve driving means 16.
It is set stronger than the elasticity of 0. Therefore, when the electromagnet body 13 is excited, the intake valve 5 is maintained in its closed position regardless of the rotation of the valve cam shaft 14, and the intake cam 1 at that time is held.
The valve opening force of 5 is accumulated in the torsion springs 20 and 20.

A buffer mechanism D ₁ is provided between the intake valve 5 and the electromagnet body 13 as a guide member for guiding the operation of the intake valve 5 to mitigate the sudden valve opening operation of the intake valve 5. The buffer mechanism D ₁ includes a step portion 32 a provided at the upper end of the intake valve 5.
And the electromagnet body 13 are provided with a hydraulic chamber 34 capable of limiting the amount of leak. That is, the through hole 30
A cap-shaped valve piece 32 slidably fitted into the large-diameter hole 29 of the through hole 30 at the upper end of the valve shaft portion 5a that is inserted into the through hole 30.
Is fitted and a hydraulic chamber 34 is defined between a step portion 32a formed by the valve piece 32 and a step portion 30a between the small diameter hole 28 and the large diameter hole 29. Through hole 3
An annular recess 31 is provided on the inner surface of the intermediate portion of the large-diameter hole 29 at 0, an oil supply hole 33 communicating with the annular recess 31 is formed in the electromagnet body 13, and the oil supply hole 33 is connected to an oil supply source (not shown). . 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, in the valve piece 32, the upper portion of the valve piece 32 is provided with the through hole 3 when the intake valve 5 is in the closed position.
0 so as to project upward from the upper end of the valve shaft portion 5a
The tappet screw 24 abuts the valve piece 32.

In FIG. 4, the buffer mechanism D is provided between the abutting portions of the first and second rocker arms 18 and 19 in the valve drive means 16.
_Two are provided. The cushioning mechanism D ₂ is formed by facing a piston 51 slidably fitted to the second rocker arm 19 and a rear surface of the piston 51 so as to exert an oil pressure for bringing the piston 51 into contact with the first rocker arm 18. And a hydraulic chamber 52.

The first rocker arm 18 is provided with an abutment arm 53 that is close to the second rocker arm 19 when the rocker arms 18 and 19 rotate due to the elastic force of the torsion spring 20.
The second rocker arm 19 is provided with a sliding hole 54 facing the contact arm 53 and opening. A cylindrical sliding member 55 having a bottom is slidably fitted in the sliding hole 54, and the piston 51 is slidably fitted in the sliding member 55. The hydraulic chamber 52 is defined between the piston 51 and the sliding member 55, and the hydraulic chamber 52 communicates with the sliding hole 54 via a throttle hole 56 provided at the closed end of the sliding member 55. To do. A valve hole 57 is formed at the closed end of the sliding member 55 in parallel with the throttle hole 56, and a spherical valve body 58 capable of opening and closing the valve hole 57 is provided in the hydraulic chamber 52. A spring 59 for urging the valve element 58 toward the closing side is housed.

A passage 60 communicating with the sliding hole 54 is bored in the second rocker arm 19, and the passage 60 is connected to a hydraulic pressure supply passage 61 provided in the rocker shaft 17 via a collar 22 and a sliding metal 21. Hydraulic communication line 6
1 is connected to a hydraulic pressure supply source (not shown). The second rocker arm 19 is provided with an accumulator 62 that faces the passage 60.

According to the buffer mechanism D ₂ , when the contact arm 53 approaches the second rocker arm 19, the piston 51 moves to the hydraulic chamber 52.
The hydraulic pressure in the hydraulic chamber 52 is increased by driving the hydraulic chamber 52 in a direction of contracting the volume of the hydraulic chamber 52.
Emitted from.

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 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 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 rapidly released, and the intake valve 5 is suddenly 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, when 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 intake valve 5 gradually opens in response to the gradual leakage from the interval. In the buffer mechanism D ₂ , the second rocker arm 19 rotates in the valve opening direction in response to the hydraulic pressure in the hydraulic chamber 52 being gradually discharged from the throttle hole 56, whereby the valve opening side of the second rocker arm 19 is opened. The operation to is relaxed. Therefore, the sudden buffering of the valve opening speed is achieved by the action of both the buffering mechanisms D ₁ and D ₂ . Moreover, the hydraulic shock absorbing action is exerted by the shock absorbing mechanism D _{1 only} when the distance l (see FIG. 3) between the lower end of the annular recess 31 and the step portion 32a in the large diameter hole 29 becomes zero. This is a state in which the released energy of the torsion springs 20, 20 is large near the maximum lift amount of the intake valve 5, while the cushioning mechanism D ₂ cushions the intake valve 5 during the opening operation. The cushioning mechanism of the intake valve 5 can be effectively achieved by complementing the mutual cushioning action by the both cushioning mechanisms D ₁ and D ₂ .

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. Further, if the electromagnetic actuator A is 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 surely opens / closes. Get the timing. Moreover, if the electromagnetic actuator A is continuously energized during the cam lift, the valve rest state can be obtained.

FIG. 8 shows a second embodiment of the present invention, and a shock absorbing mechanism D ₃ is provided at the abutting portions of the first and second rocker arms 18 and 19.

The cushioning mechanism D ₃ is formed so as to face the rear surface of the piston 64 so as to exert a hydraulic pressure that causes the piston 64 slidably fitted to the second rocker arm 19 and the piston 64 to contact the first rocker arm 18. The hydraulic chamber 65 is provided.

The second rocker arm 19 is provided with a slide hole 54 that is opened so as to face the contact arm 53 of the first rocker arm 18. A bottomed cylindrical piston 64 is slidably fitted in the sliding hole 54, and a cylindrical sliding member 66 is relatively slidably fitted in the piston 64. The hydraulic chamber 65 is defined between the piston 64 and the sliding member 66, and the hydraulic chamber 65 communicates with the inside of the sliding hole 54 through the gap between the piston 64 and the sliding member 66. A valve hole 67 is formed in the sliding member 66,
The hydraulic chamber 65 accommodates a spherical valve body 68 that can open and close the valve hole 67 and a spring 69 that biases the valve body 68 toward the closing side. Further, the sliding member 66 is the second rocker arm 1
It is urged in the direction of fitting into the piston 64 by a spring 70 interposed between the piston 9 and the piston 9.

Further, the sliding hole 54 is connected to the rocker shaft 1 via the passage 60.
As in the first embodiment, the hydraulic pressure supply passage 61 in the valve 7 is always communicated with, and the accumulator 62 is disposed in the middle of the passage 60.

According to the buffering mechanism D _3, piston 64 when the Tose'ude 53 proximate to the second rocker arm 19 is a hydraulic chamber 65
The hydraulic pressure in the hydraulic chamber 65 is increased by driving in the direction of contracting the volume of the hydraulic pressure, but the hydraulic pressure is discharged to the sliding hole 54 from the gap between the piston 64 and the sliding member 66, and the buffer of the first embodiment is buffered. A cushioning effect similar to that of the mechanism D ₂ can be achieved.

9 and 10 show a third embodiment of the present invention, in which a shock absorbing mechanism D ₄ is provided at the abutting portions of the first and second rocker arms 18 and 19.

The cushioning mechanism D ₄ includes a sphere 72 slidably fitted to the second rocker arm 19, and a hydraulic chamber 73 formed so as to face the back surface of the sphere 72. The sphere 72 has a hydraulic pressure of the hydraulic chamber 73. Thus, the first rocker arm 18 is urged in the direction of coming into contact with the contact arm 53.

A sliding hole 74 is formed in the second rocker arm 19, and the sphere 72 is fitted into the sliding hole 74. Moreover, a restricting flange portion 75 for preventing the spherical body 72 from falling out of the sliding hole 74 is provided at the opening end of the sliding hole 74 over the entire circumference, and a spherical body is provided inside the restricting flange portion 75. A concave portion is provided which forms an annular gap 76 with respect to 72. Further, the passage 60 provided in the second rocker arm 19 and the hydraulic chamber 7
The second rocker arm 19 is provided with a valve hole 77 connecting the valve hole 3 and the valve hole 77, and a spherical valve body 78 capable of opening and closing the valve hole 77 and a spring 79 for biasing the valve body 78 toward the closing side are provided in the hydraulic chamber. It is stored in 73.

In this buffer mechanism D ₄ , when the sphere 72 is pushed by the contact arm 53, the oil pressure in the hydraulic chamber 73 leaks from the gap 76, and the moving speed of the sphere 72 is determined according to the leak amount, so that the valve opening is performed. The rotation speed of the second rocker arm 19 at this time is moderated.

11, FIG. 12, FIG. 13, FIG. 14 and FIG.
The drawing shows a fourth embodiment of the present invention, and the portions corresponding to the first embodiment are designated by the same reference numerals.

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 ₅ is provided between the rocker arm 36 and the stopper 40 fixed to the sliding plunger 37. The buffer mechanism D ₅ 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 61 in the rocker shaft 17 via a passage 49 formed in the rocker arm 36. The buffer mechanism D ₅ is provided with 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.

Other configurations are similar to those of the first embodiment, and the sum of the attraction force of the electromagnetic actuator A and the spring force of the valve springs 11 and 12 is set to be larger than the elastic force of the torsion springs 38 and 38. A buffer mechanism D ₁ is provided between the electromagnet body 13 and the valve shaft portion 5 a of the intake valve 5.

According to the fourth 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 position portion 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. As shown in FIG. 15, the intake valve 5 can be suddenly actuated to open the intake valve 5 instantaneously. At this time, the cushioning mechanisms D ₁ and D ₅ reduce the valve opening operation speed. be able to.

Further, in the fourth 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, FIG. 17 and FIG. 18 show a fifth embodiment of the present invention, and the portions corresponding to the above embodiments 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 serves as a first driving member, and the lifter lower portion 91 slides from its released 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.

A cushioning mechanism D ₆ is provided between a lifter lower portion 91 as an interlocking member that is interlocked with and connected to the intake valve 5 and a support cylinder 86 as a guide member that guides the movement of the lifter lower portion 91. A cushioning mechanism D ₇ is provided between 91 and the lifter upper portion 92.

The buffer mechanism D ₆ includes the outer peripheral surface of the lower lifter 91 and the support cylinder 36.
An annular hydraulic chamber 97 is provided between the inner peripheral wall of the
In the hydraulic chamber 97, a fuel filler port 98 formed in the support cylinder 86 is provided.
And an oil discharge port 99 are communicated with each other, and a hydraulic circuit, for example, a lubricating oil circuit of an engine, is communicated with the hydraulic chamber 97 so that pressurized oil circulates in the chamber 97. 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.

Buffering mechanism D ₇ is made by hydraulic pressure chamber 101 is provided between the set nut 95 and the lifter upper 92 integral with the lifter lower 91, the hydraulic chamber 101 is the fuel supply port via the communicating passage 102 drilled in the lifter lower portion 91 It is possible to communicate with 98. Moreover, the communication passage 102 communicates with the fuel filler port 98 in a state where the lifter upper portion 92 is pushed down to the maximum while keeping the intake valve 5 closed, and the lifter upper portion 92 is moved to the maximum downward and the lifter 92 is lifted to the maximum. When the lower portion 91 is pushed down, the lower portion 91 is pierced so that the communication state with the fuel filler port 98 is blocked.

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. Can be held, and at this time, the hydraulic chambers 97, 10
1 is filled with hydraulic pressure.

Next, when 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, the buffer mechanism D is activated in response to the opening operation of the intake valve 5.
_Since the hydraulic pressure is confined in the hydraulic chamber 101 of No. _{7, and} the hydraulic pressure leaks from the gap between the set nut 95 and the lifter upper part 92 and the gap between the lifter lower part 91 and the lifter upper part 92, the lifter lower part 91 is pushed down.
The opening operation of the intake valve 5 is eased. Thus, the cushioning action of the cushioning mechanism D ₇ is effective over the entire lift region of the intake valve 5.

Further, when the lift amount of the intake valve 5 becomes close to the maximum as shown in FIG. 18, the hydraulic pressure is confined in the hydraulic chamber 97 of the buffer mechanism D ₆ , and the hydraulic pressure leaks from the gap between the lower lifter 91 and the support cylinder 86. . Therefore, the lifter springs 93, 9
In a region where the energy released by 4 increases, the valve opening operation of the intake valve 5 is moderated by the buffering action of the buffering mechanism D _{7 and} the buffering action of the buffering mechanism D ₆ .

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

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 one feature of the present invention, the valve drive means includes the 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 cam. Between the two, there is provided a holding means for holding the engine valve in the valve closing position while accumulating the valve opening force by the valve operating cam in the valve opening elastic member.
The holding state and the holding release state are switchable to control the opening timing of the engine valve according to the operating state of the engine.The valve driving means opens the valve driving means by the elastic force of the valve opening elastic member. Since a buffer mechanism is added to alleviate valve operation, it is possible to set the optimum valve opening timing according to the operating state of the engine by controlling the holding state release timing of the holding means, increasing the intake and exhaust inertia effects and The intake efficiency or the exhaust efficiency can be improved, and furthermore, the function of the cushioning mechanism can alleviate the valve opening operation of the engine valve due to the elastic force of the valve opening elastic member and prevent the engine valve from being damaged.

According to another feature of the invention, the valve drive means includes a valve-opening elastic member that exerts elastic force in the valve-opening direction of the engine valve,
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. , A holding state and a holding release state can be switched to control the opening timing of the engine valve according to the operating state of the engine, and the engine valve or an interlocking member interlocked with and linked to the engine valve, the engine valve or Since a buffer mechanism is provided between the fixed guide member that guides the operation of the interlocking member and the valve opening operation of the engine valve due to the elastic force of the valve opening elastic member, a holding state release timing of the holding unit is provided. By controlling the, it is possible to set the optimum valve opening timing according to the operating state of the engine, and it is possible to enhance the intake and exhaust inertia effects to enhance the intake efficiency or exhaust efficiency,
Moreover, the function of the buffer mechanism can alleviate the valve opening operation of the engine valve due to the elastic force of the valve opening elastic member and prevent the engine valve from being damaged.

[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 an essential part for showing the buffer mechanism attached to the valve drive means, and FIG. 5 shows the relationship between the valve opening lift 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. FIG. 8 is a longitudinal sectional view of an essential part corresponding to FIG. 4 of the second embodiment of the present invention, FIGS. 9 and 10 show a third embodiment of the present invention, and FIG. 10 is a longitudinal sectional view of a main part corresponding to FIG. 10, FIG. 10 is an enlarged view of part X in FIG. 9, and FIGS. 11 to 15 show a fourth embodiment of the present invention.
The figure is a vertical side view, FIG. 12 is a view taken along line XII-XII in FIG. 11, FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG.
FIG. 15 is a vertical sectional side view corresponding to FIG. 11 showing a valve closed position holding state by the holding means, FIG. 15 is a vertical sectional side view corresponding to FIG. 11 showing a holding released state by the holding means, FIG.
FIGS. 17 and 18 show a fifth embodiment of the present invention. FIG. 16 is a vertical sectional side view showing a valve closed position holding state by the holding means, and FIG. 17 is a valve closed position holding state by the holding means. First when the engine valve is released and the engine valve is in the process of opening.
6 is a vertical sectional side view corresponding to FIG. 6, and FIG. 18 is a vertical sectional side view corresponding to FIG. 16 when the engine valve is in a fully opened state. 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,
34, 44, 52, 65, 73, 97, 101 ... Hydraulic chamber, 36 ... Rocker arm as first drive member, 37 ...
Sliding plunger as second drive member, 51, 64 ... Piston, 72 ... Sphere, 74 ... Sliding hole, 86 ... Support cylinder as guide member, 90 ... Valve lifter as valve driving means, 9
1 ... Lower lifter as first drive member, 92 ... Upper lifter as second drive member, 93, 94 ... Lifter spring as elastic member for valve opening, A ... Electromagnetic actuator as holding means, D _{1 to} D ₇
... buffer mechanism, E ... engine body

Claims (10)

[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 in order to control the valve opening timing of the engine valve according to the operating state of the engine, and the valve driving means uses the elastic force of the valve opening elastic member to drive the valve. A valve operating control device for an internal combustion engine, further comprising a shock absorbing mechanism for reducing a valve opening operation of the means. 2. The valve drive means includes first and second drive members which are relatively displaceable, and a valve opening elastic member interposed between the drive members, and the shock absorbing mechanism has a collision between the drive members. The valve operation control device for an internal combustion engine according to item (1), characterized in that the valve drive control device is provided at a contact portion. 3. A buffer mechanism is provided 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 which is swingable around an axis common to the first rocker arm. The cushioning mechanism is provided and includes a piston slidably fitted to one of the first and second rocker arms, and a piston for exerting hydraulic pressure to bring the piston into contact with the other of the first and second rocker arms. A hydraulic chamber formed so as to face the back surface of the
A valve operating system for an internal combustion engine according to the item (2). 4. A buffer mechanism is provided 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 which is swingable around an axis common to the first rocker arm. The cushioning mechanism is provided with a sliding hole formed in one of the first and second rocker arms, a sphere slidably fitted in the sliding hole, and the sphere having first and second spheres. A hydraulic chamber formed so as to contact the other side of the rocker arm so as to face the back surface of the spherical body, and the hydraulic pressure of the hydraulic chamber between the outer surface of the spherical body and the inner surface of the sliding hole when the spherical body moves toward the inside of the sliding hole. A valve control device for an internal combustion engine according to item (2), characterized in that a gap capable of leaking is formed. 5. A valve cam side rocker arm as a first drive member and a sliding plunger as a second drive member slidably supported by the rocker arm so as to abut the engine valve. The valve operating control system for an internal combustion engine according to item (2), characterized in that a buffer mechanism having a hydraulic chamber capable of limiting the amount of leak is provided. 6. A leak amount between a lower part of a lifter on the engine valve side as a first drive member and an upper part of a lifter on a valve cam side as a second drive member slidably fitted to the lower part of the lifter. A valve mechanism for an internal combustion engine according to item (2), characterized in that a shock absorbing mechanism having a hydraulic chamber capable of limiting the above is provided. 7. 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 in order to control the opening timing of the engine valve according to the operating state of the engine, and the engine valve or an interlocking member interlocked with and connected to the engine valve, and the engine. The elastic force of the valve opening elastic member between the valve and the fixed guide member that guides the operation of the interlocking member. Buffering mechanism to mitigate the valve opening operation of the engine valve by valve operation controller for an internal combustion engine, wherein a is attached. 8. The shock absorbing mechanism comprises a hydraulic chamber capable of limiting a leak amount between a step portion formed at an upper end portion of the engine valve and a guide member for guiding the operation of the engine valve. A valve train control device for an internal combustion engine according to item (7). 9. The valve drive means includes a lower portion of a lifter on the engine valve side,
The upper part of the lifter slidably fitted to the lower part of the lifter, and the elastic member for valve opening interposed between the lower part of the lifter and the upper part of the lifter, and the buffer mechanism is the lower part of the lifter as an interlocking member and the movement of the lower part of the lifter. A hydraulic chamber capable of limiting a leak amount is provided between the support cylinder as a guide member fixed to the cylinder head for guiding the hydraulic pressure.
A valve operating system for an internal combustion engine according to item (7). 10. The valve operating system for an internal combustion engine according to claim 1 or 7, wherein the holding means is an electromagnetic actuator.