JPH01305114A - Valves system control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To enable a valve open timing to be setin optimal state by installing, between an engine valve and a valve system cam, a means for holding the engine valve in this closed position while accumulating, as pressure, the valve opening force generated by the valve system cam, and making changeover between holding and releasing state. CONSTITUTION:When a valve system cam shaft 14 turns following the operation of an internal combustion engine, an intake valve 5 is opened and closed through cooperative action of an intake cam 15 and each of valve springs 11, 12. If the internal combustion engine is under, for instance, low load condition, in this case, a solenoid actuator A is electrified by a control circuit C before the intake valve 5 is lifted so as to have a magnetic body 9 adsorbed to an electromagnet 13. Then, a second rocker arm 19 is blocked from its turning movement so that the turning movement force of a first rocker arm 18 put in turning movement by the intake cam 15 may be stored in a torsion spring 20. When a lift amount caused by the intake cam 15 reaches a distance just before its maximum value, electrification is shut off from the solenoid actuator A, so as to have the intake valve 5 opened rapidly by means of the energy stoved in the torsion spring 20.

Description

Detailed Description of the Invention A8 Object of the Invention (1) Industrial Application Field The present invention relates to an engine valve supported on an engine body so as to be openable and closable;
It has a valve spring that biases the engine valve in the valve closing direction, a rocking member that can swing around an axis perpendicular to the opening and closing movement direction of the engine valve, and a force in the valve opening direction from a valve driving cam is applied to the engine valve. The present invention relates to a valve control device for an internal combustion engine, which includes a valve drive cam and a valve drive means interposed between engine valves for transmitting information.

(2) Conventional technology Conventionally, in addition to controlling the opening and closing of intake valves or exhaust valves as engine valves by the cooperative action of a valve drive cam and a valve spring, it is also possible to control the opening and closing of the intake valve or exhaust valve as an engine valve by operating an electromagnetic actuator depending on the operating state of the engine. A device capable of controlling opening and closing is already known (see Japanese Utility Model Application Publication No. 59-52111).

(3) Problems to be Solved by the Invention The present applicant has proposed an engine valve opening/closing control device that maximizes the suction force of an electromagnetic actuator to improve engine performance ( Special request 1986
-123647) However, in this model, the engine valve is opened by energizing the electromagnetic actuator, and then closed all at once by the spring force when demagnetized, so the valve closing timing can be controlled, but inertial supercharging is effective. There was a problem in that variable control of the valve opening timing, which can be used in other applications, was not possible.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a valve train control device for an internal combustion engine that can solve the above problems with a simple configuration.

B0 Structure of the Invention (1) Means for Solving the Problems According to the present invention, the valve driving means includes a valve-opening elastic member that exerts an elastic force in the valve-opening direction of the engine valve. A holding means is interposed between the valve cam and the engine valve to hold the engine valve in the closed position while accumulating the valve-opening force generated by the valve-driving cam in the valve-opening elastic member. It 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 state.

(2) Effect According to the above configuration, the engine valve can be held in the closed position by the holding means regardless of the operating state of the engine and regardless of the opening/closing operation of the engine valve by the valve drive cam and valve spring. , 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 suddenly.

(3) Examples Examples of the present invention will be explained below with reference to the drawings.
First, in FIG. 1 showing a first embodiment of the present invention, a cylinder head 1 of an engine body E is formed with a combustion chamber 2 and an intake boat 3 communicating with the combustion chamber 2. , and is connected to an intake system including a fuel supply device 4.

The cylinder head 1 also has a combustion chamber 2 of the intake boat 3.
An intake valve 5 is provided as an engine valve whose side opening end can be opened and closed. This intake valve 5 is composed of a valve stem part 5a and a valve body part 5b, the valve stem part 5a is slidably fitted into a valve guide 6 fixed to the cylinder head 1, and the valve body part 5b
can be seated on the valve seat 7 at the open end of the intake boat 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 stem portion 5a via a retainer 8.
is installed. Valve springs 11 and 12 made of compression coil springs are compressed between the spring retainer 9 and a spring seat 10 formed on the cylinder hood 1 facing the spring retainer 9. The generated force 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 13 to be described later.

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

The valve driving means 16 includes a rocker shaft 17 fixedly disposed in parallel above the valve camshaft 14 between the valve camshaft 14 and the intake valve 5, and a rocker shaft 17 that is in sliding contact with the intake cam 15 to prevent rocking. The first t supported on the shaft 17! The 10th lug arm 18 as a moving member, the 20th lug arm 19 as a second swinging member supported by the rocker shaft 17 so as to swing while contacting the upper end of the intake valve 5, and the 20th lug arm 19 as a second swinging member. -mu18. Torsion springs 20, 20 are provided as valve opening elastic members which are interposed between the intake valve 19 and exert a spring force in the 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. As shown in FIG. This collar 22 is basically formed into a cylindrical shape, and retaining rings 23 and 23 abutting both ends of the collar 22 are fitted onto the sliding metal 21. A torsion spring 20 is provided at both ends of the collar 22 in the axial direction.
drum parts 22a, 22a are provided for winding the collar 20, and the proximal ends of the first and twentieth hook arms 18, 19 are located between the drum parts 22a, 22a in a portion closer to the center in the axial direction of the collar 22. Rotatably supported.

The tenth claw arm 18 extends from the rocker shaft 17 toward the intake cam 16, and the cam surface of the intake cam 16 is in sliding contact with the lower surface of the tip of the tenth claw arm 18. Further, since the base of the 20th claw arm 19 does not come into sliding contact with the base of the 10th claw arm 18, the rocker shaft 1
7 to the intake valve 5 side. A tappet screw 24 that abuts the upper end of the valve shaft portion 5a of the intake valve 5 is screwed into the tip of the twentieth hook arm 19 so as to be movable forward and backward. In addition, a locking nut 25 that comes into contact with the upper surface of the tip of the 20th hook arm 19 is screwed into the 8-tappet screw 24 in order to maintain the adjusted forward and backward positions.

Locking pins 26.27, which are parallel to the rocker shaft 17, are fixed to the first and 20th hook arms 18.19 so as to protrude from both sides, and are wound around the drum parts 22a, 22a of the collar 22, respectively. Torsion spring 2
One end of 0, 20 is the locking pin 26 of the tenth hook arm 18.
The other end is engaged with the locking pin 27 of the 20th hook arm 19, respectively. As a result, the first and 20th lever arms 18.19 are connected to the 10th lever arm 1.
8 toward the intake cam 15 side, and the 20th hook arm 19 toward the intake valve 5 side. Moreover, the elastic force of both torsion springs 20, 20 is set to be stronger than that of the valve springs 11, 12. Therefore, the valve train camshaft 14
When the intake cam 15 rotates, the intake cam 15 presses the intake valve 5 downward via the valve drive means 16, and can slide it in the valve opening direction, that is, in the downward direction.

Referring also to FIG. 3, an annular electromagnet body 13 that faces the upper surface of the spring retainer 9 and surrounds the valve shaft portion 5a of the intake valve 5 is fixed to the cylinder head l. constitutes an electromagnetic actuator A together with the magnetic body 9 which also serves as the spring retainer. Also, the electromagnet body 13
, a small diameter hole 28 that comes into sliding contact with 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 larger diameter than the small-diameter hole 28 is coaxially connected in order from the bottom, and the valve shaft portion 5a of the intake valve 5 is movable in the axial direction. hole 30
inserted into.

The magnetic body 9 is attracted to the electromagnet 13 by excitation of the solenoid in the electromagnet 13 . The adsorption force of the electromagnetic actuator A and the spring force of the valve springs 11 and 12 are set to be stronger than the elastic force of the torsion springs 20 and 20 in the valve driving means 16. Therefore, when the electromagnet 13 is energized, the intake valve 5 is held in its closed position regardless of the rotation of the valve drive camshaft 14, and the valve opening force generated by the intake cam 15 at that time is accumulated in the torsion springs 20 and 29. become.

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 electromagnetic body 13 . Further, at the upper end of the valve shaft portion 5a inserted into the through hole 30, there is a cap-shaped valve piece 32 that is slidably fitted into the large diameter hole 29 of the through hole 30.
is fitted. Moreover, the valve piece 32 is connected to the intake valve 5.
When the valve piece 32 is in the closed position, the upper part of the valve piece 32 projects upward from the upper end of the through hole 30 and is fitted onto the valve shaft 5a, and the tappet screw 24 is inserted into the valve piece 3.
2. Furthermore, an oil supply hole 33 communicating with the annular recess 31 of the through hole 30 is bored in the electromagnetic body 13, and this oil supply hole 33 is connected to an oil supply source (not shown).

A control circuit C is connected to the solenoid of the electromagnetic body 13 and operates by detecting the operating state of the engine.
energization and de-energization of the electromagnet 13 are switched and controlled by signals from the electromagnet 13. Furthermore, detection signals such as engine speed, temperature, throttle opening, and intake air amount are input to the control circuit C as signals for detecting the operating state of the engine.

Next, the operation of the first embodiment will be explained with reference to FIGS. 4, 5, and 6. When the valve camshaft 14 is rotationally driven by engine operation, the intake cam 15 and the valve In cooperation with the springs 11 and 12, the intake valve 5 is driven to open and close at a predetermined timing. Thus, the opening lift amount of the intake valve 5 relative to the rotation angle of the valve drive camshaft 14 draws a lift curve as shown by the dashed line in FIG.

By the way, when the engine is in a specific operating state, for example, in a low-load operating state, while the inside of the base of the intake cam 15 is in sliding contact with the tenth lug arm 18, as shown in FIG. Before the magnetic body 9 becomes the electromagnet 1, the electromagnetic body 13 is energized under the control of the control circuit C.
Let it adsorb to 3.

Next, as the intake cam 15 rotates, the higher portion of the intake cam 15 comes into sliding contact with the tenth claw arm 18.
The tenth claw arm 18 is rotated clockwise in FIG. 1, and the rotational force is transmitted via the torsion spring 20, 20, and a pressing force in the clockwise direction in FIG. 1 also acts on the twentieth claw arm 19. However, as mentioned above, the spring force of the electromagnetic actuator A and the valve spring 11, 12 is equal to the torsion spring 20, 20.
Since the elastic force is stronger than that of the torsion spring 2, the rotation of the 20th claw arm 19 is prevented, and as shown in FIG.
The tenth hook arm 18 only rotates while twisting the angles 0 and 20. As a result, the intake valve 5 is maintained at its closed position, and the valve opening force exerted by the intake cam 15 is accumulated in the torsion springs 20, 20.

When the valve train camshaft 14 continues its rotation and the rotation angle reaches, for example, near point P in FIG. 4, that is, just before the lift it by the intake cam 15 reaches its maximum, the electromagnet body When the power to 13 is cut off, the magnetic body 9
The power to absorb is released. As a result, the torsion spring 2
The valve opening force that had been accumulated at 0.20 was suddenly released,
As shown in FIG. 6, the intake valve 5 is suddenly opened by the elastic force of the torsion springs 20, 20, and the valve opening lift increases linearly as shown by the large solid line in FIG. As a result, the air-fuel mixture flowing through the intake system flows into the combustion chamber 2 at once.

By the way, if the internal combustion engine is in the intake stroke in which the piston descends and the intake valve 5 is in the closed state as shown in FIG.
Due to the downward movement of the piston, the inside of the combustion chamber 2 has a much higher negative pressure than the conventional one, and in this state, when the intake valve 5 opens instantaneously as shown in Fig. 6, combustion starts from the intake system. The intake air flowing into the chamber 2 is supercharged due to the high inertia effect, and the stacked intake air is supplied to the combustion chamber 2, achieving a supercharging effect in low-load operating conditions and improving output. It will be done.

Moreover, when the holding state is released by the electromagnetic actuator A, the valve piece 32 attached to the valve stem 5a of the intake valve 5 slides downward within the through hole 30 of the electromagnet body 13, but the valve piece 32 is inserted into the large diameter hole. 29, the lower surface of the valve piece 32, the small diameter hole 28 and the large diameter hole 29
Since the hydraulic pressure is trapped between the steps in between, valve piece 3
The downward movement speed of 2, that is, the opening speed of the intake valve 5 is relaxed, and as the trapped hydraulic pressure gradually leaks from between the valve piece 32 and the small diameter hole 28, the intake valve 5 gradually opens and suddenly opens. A buffering of the valve opening speed is achieved.

After the lift amount of the intake valve 5 reaches the maximum, the intake valve 5 is closed while drawing a normal lift curve due to the cooperative action of the intake cam 15 and the valve springs 11 and 12.

Moreover, in the valve drive means 16, the torsion spring 20.20
By arranging the rocker shaft 17 around the rocker shaft 17, it is possible to reduce the inertial weight. Also, the valve camshaft 1
4 is not disposed directly above the intake valve 5, and an increase in the overall height due to the valve operating camshaft 14 being disposed above the intake valve 5 can be avoided.

Note that the valve-open holding action by the electromagnetic actuator A can be performed at any timing as shown by the solid line in FIG. 4, regardless of the operating state of the engine. That is, the valve opening timing can be arbitrarily changed from immediately after the start of the cam lift to the maximum lift, and from the maximum lift to just before the end of the cam lift. Furthermore, if the electromagnetic actuator A is constantly de-energized, the opening/closing timing can be obtained in accordance with the cam profile, and furthermore, both rocker arms 1
If the relative rotation of 8.19 is prevented, opening/closing timing that reliably follows the cam profile can be obtained.

Furthermore, if the electromagnetic actuator A is continued to be energized during the cam lift, the state on the valve body can be obtained.

7, 8, 9, 10, and 11 show a second embodiment of the present invention, and parts corresponding to the first embodiment are given the same reference numerals. .

A valve driving means 35 is interposed between the intake valve 5 and the intake cam 15, and the valve driving means 35 is a rocking member that is not in sliding contact with the intake cam 15 and is rotatably supported on the rocker shaft 17. A rocker arm 36 as a member, a sliding piston 37 as a sliding member supported by the rocker arm 36 so as to be able to freely slide without contacting the upper end of the valve shaft portion 5a of the intake valve 5, and between the rocker arm 36 and the sliding piston 37. It is provided with torsion springs 3B, 3B as elastic members for opening the valve, which are interposed in the valve opening.

The rocker arm 36 is supported by the rocker shaft 17 via a collar 39. Further, the sliding piston 37 includes a rocker arm 36 of the sliding piston 37.
A basically cylindrical stopper 40 that slidably fits on the rocker arm 36 to define the lowest position relative to the sliding piston 36 is threaded with a variable axial relative position to the sliding piston 36 . A locking nut 41 for fixing the position is screwed.

That is, the rocker arm 36 has a large diameter hole 42 and a small diameter hole 4.
3 and 3 are drilled coaxially in order from the top,
The stopper 40 includes a large diameter portion 40a that is slidably fitted into the large diameter hole 42 and a small diameter portion 4 that is slidably fitted into the small diameter hole 43.
0b is provided.

Thus, the step between the large diameter portion 40a and the small diameter portion 40b comes into contact with the step between the large diameter hole 42 and the small diameter hole 43, thereby defining the lowest position of the stopper 40, that is, the sliding piston 37 with respect to the rocker arm 36. Ru. Moreover, by supplying hydraulic pressure to the annular chamber 44 defined between the rocker arm 36 and the stopper 40, a buffering effect when the sliding piston 37 slides downward is achieved.

An arm member 46 is fixed to the lower part of the sliding piston 37 via a lever 45. That is, the arm member 46 consists of a disk portion 46a and bottle-shaped locking portions 46b, 46b that protrude from the disk portion 46a along one diameter line, and the diameter becomes smaller toward the top. Insert the socket 4 into the hole 47 provided in the center of the disc portion 46a.
5, the arm member 46 is fixed to the sliding piston 37.

One end of the torsion springs 3B, 3B is engaged with a locking pin 48 fixed to the rocker arm 36 so as to be parallel to the rocker shaft 17 and protrude to both sides, and the other end is engaged with both locking portions of the arm member 46. 46b, 46b.

This torsion spring 38.degree. 38 exerts an elastic force in the direction of bringing the rocker arm 36 into sliding contact with the intake cam 15, and in the direction of bringing the sliding piston 37 into contact with the intake valve 5.

The other configurations are the same as in the first embodiment, and the adsorption force of the electromagnetic actuator A and the spring force of the valve springs 11, 12 are set larger than the elastic forces of the torsion springs 3B, 3B.

According to this second embodiment, by energizing the electromagnetic body 13 of the electromagnetic actuator A, the sliding piston 37 is moved to the rocker arm 36 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 open position by moving the intake valve 5 upward relative to the torsion spring 38.
, 3B is suddenly applied to the intake valve 5 as shown in FIG. 11 in response to the release of the holding state by the electromagnetic actuator A, so that the intake valve 5 can be opened instantly. can.

This second embodiment can also provide the same effects as the first embodiment. Furthermore, it is also possible to provide a mechanism for preventing relative displacement of the sliding piston 37 with respect to the rocker arm 36.

Furthermore, in this second embodiment, since the swinging member is not divided into two parts as in the first embodiment, the supporting length of the rocker arm 36 with respect to the rocker shaft 17 is compared in order to ensure surface pressure against the rocker shaft 17. It can be made longer. Furthermore, the structure is simple, which is advantageous in terms of machinability such as drilling and ensuring accuracy.

FIG. 12 shows a third embodiment of the present invention, and parts corresponding to each of the above embodiments are given the same reference numerals.

This third embodiment is similar to the second embodiment, but what should be noted is that the rocker arm 36' contacts the valve shaft 5a of the intake valve 5, and the sliding piston 37' contacts the intake cam 15. is slidably supported on the rocker arm 36'.

This third embodiment can also provide the same effects as the second 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 an internal combustion engine has been explained, but it is also possible to apply this to the opening/closing mechanism of the exhaust valve. When the valve is suddenly opened, pressurized exhaust gas flows into the exhaust system all at once, increasing exhaust inertia and improving exhaust efficiency, thereby increasing output.

C0 Effects of the Invention As described above, according to the present invention, the valve driving means includes a valve opening elastic member that exerts an elastic force in the valve opening direction of the engine valve, and the valve driving means has a valve opening elastic member that exerts an elastic force in the valve opening direction of the engine valve. is equipped with a holding means capable of holding the engine valve in the valve-closing position while accumulating the valve-opening force generated by the valve-driving cam in the valve-opening elastic member. Since the holding state and the holding release state can be switched to control the valve opening timing of the holding means, the optimum valve opening timing can be set according to the operating state of the engine by controlling the holding state release timing of the holding means. , the intake efficiency or exhaust efficiency can be increased by increasing the inertia effects of intake and exhaust.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the present invention, FIG. 1 is a vertical side view, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 4 is a diagram showing the relationship between the valve opening lift and the rotation angle of the valve drive cam, and FIG. 5 corresponds to FIG. 1 showing the valve closing position held by the holding means A longitudinal side view, FIG. 6 is a longitudinal side view corresponding to FIG. 1 showing a state in which the holding means is released, and FIGS.
1 shows a second embodiment of the present invention, FIG. 7 is a vertical sectional side view, FIG. 8 is a fixation view taken along the line ■-■ in FIG. 7, and FIG. 10 is a longitudinal sectional side view corresponding to FIG. 7 showing the state in which the valve is held in the closed position by the holding means; FIG. 11 is a longitudinal sectional side view corresponding to FIG. 7 showing the state in which the holding is released by the holding means. , FIG. 12 is a longitudinal sectional side view corresponding to FIG. 1 for showing a third embodiment of the present invention. 5... Intake valve as engine valve, 11.12... Valve spring, 15... Intake cam as valve operating cam, 16.35
... Valve drive means, 1B, 19, 36.36'... Rocker arm as a swinging member, 20.38... Torsion spring as an elastic member for M valve, 37.37'... Sliding Sliding piston as a member, 45...cock, 46...arm member, 46b...locking part, A
...Electromagnetic actuator as a holding means, E...
Engine body

Claims (5)

[Claims] (1) An engine valve that is supported by the engine body so that it can be opened and closed, a valve spring that biases the engine valve in the closing direction, and a swinging member that can swing around an axis perpendicular to the opening and closing movement direction of the engine valve. and a valve drive means interposed between the valve drive cam and the engine valve to transmit the force in the valve opening direction by the valve drive cam to the engine valve, the valve drive means comprising: , is equipped with a valve-opening elastic member that exerts an elastic force in the valve-opening direction of the engine valve, and between the engine valve and the valve-driving cam, the valve-opening force generated by the valve-driving cam is accumulated in the valve-opening elastic member. A holding means capable of holding the engine valve in the closed position is provided, and the holding means can be switched 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. A valve control device for an internal combustion engine, characterized in that: (2) The valve control device for an internal combustion engine according to item (1), wherein the holding means comprises an electromagnetic actuator. (3) The valve driving means includes a first swinging member on the valve cam side, a second swinging member on the engine valve side that can swing around a common axis with the first swinging member, and both swinging members. Item (1) or (1), characterized in that the valve-opening elastic member is interposed between the
The valve control device for an internal combustion engine according to item 2). (4) The valve driving means includes a swinging member, a sliding member that is slidably supported by the swinging member while abutting either the valve drive cam or the engine valve, and the swinging member and the sliding member. A valve control device for an internal combustion engine according to item (1) or item (2), characterized in that the device comprises a valve-opening elastic member interposed between the valve-opening elastic members. (5) An internal combustion engine according to item (4), characterized in that an arm member is fixed to the sliding member via a cotter, and the arm member is provided with a locking portion of an elastic member for opening the valve. valve control device.