JPS5853616A - Intake and exhaust valve opening/closing control device for 4-stroke internal combustion engine - Google Patents

Abstract

PURPOSE:To optimize control of a valve in such a way that timing of a valve is adjusted by using an adjusting member which is driven by a solenoid valve on the basis of working condition of the engine. CONSTITUTION:A pivotally supported member 14 is supported through an adjusting coil spring 15 on an adjusting member 16, the adjusting member 16 is formed in the shape of a piston, and it is inserted oil-tightly to a hydraulic cylinder 17, and to be freely elevated up and down. Further, the hydraulic cylinder 17 is connected through a check valve 18 to a hydraulic path 19, and it is connected through a solenoid valve 20 to a relief path 21. In the condition that the solenoid valve 20 is closed, pressured oil is sealed in the cylinder 17. When the solenoid valve 20 is opened, the pressured oil is supplied into the relief path 21. Thus, timing of suction and exhaust valves in the engine can be optimally controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake/exhaust valve opening/closing control device for an internal combustion engine.

High speed type 4+? In a cycle internal combustion engine, the inertial effect of the intake and exhaust is utilized by increasing the time during which the intake and exhaust valves are open at the same time, that is, the valve overlap time.
Although high output was intended, this flow caused combustion to deteriorate and low-speed output tended to decrease.

For this reason, if a plurality of intake valves are provided and one of the intake valves is stopped in a low-speed operating range or a low-load operating range,
Mechanisms that increase the flow velocity of the air-fuel mixture and utilize inertia effects have existed for some time, but they were complex, expensive, and lacked durability.

The present invention relates to an improvement of an intake/exhaust valve opening/closing control device for a four-stroke internal combustion engine that eliminates such inconveniences, and its purpose is to provide an inexpensive intake/exhaust valve opening/closing control device with a simple structure and high durability. The point is to provide equipment.

An embodiment of the present invention illustrated in FIGS. 1 and 2 will be described below.

3 is a cylinder and a head provided at the top of the cylinder (not shown), and the cylinder head 1 includes a main intake valve passage 3, a sub-intake passage 4, and a main and sub-exhaust valve 1.
0 are interposed so that they can be opened and closed.

Further, each of the main intake valves 7 and the main exhaust valves 9 is driven to open and close at a constant timing (at a constant crank angle) by a normal valve opening/closing mechanism, regardless of the engine operating state.

Furthermore, in each of the sub-intake valves 8 and sub-exhaust valves 10,
As will be explained in detail later, the valve opening/closing timing is variably controlled or the valve operation is stopped depending on the engine operating state.

In FIG. 2, the detailed structure of the sub-intake valve 8 will be explained, but since the sub-exhaust valve 10 has a similar structure, the explanation of the sub-exhaust valve 10 will be omitted.

The sub-intake valve 8 is attached with a valve actuating coil spring 11 that biases the sub-intake valve 8 in a direction to close it.

In addition, in the rocker arm 13 that transmits the operation of the intake cam 12 to the sub-intake valve 8, the lower surface of one end thereof is connected to the top end of the sub-intake valve 8 via the adjustment screw 22, and the lower surface of the other end is connected to the pivot member 14 at its center. The upper surface of the portion is supported in contact with the intake cam 12. Note that the bolt 23 fixes the adjustment screw n to one end of the rocker arm 13.

Further, the pivot member 14 has an adjusting coil spring 15.
The adjustment member 16 is formed in the shape of a piston and is fitted into a hydraulic cylinder 17 in an oil-tight manner so as to be able to move up and down.

Furthermore, when the hydraulic cylinder 17 is connected to the pressure oil passage 19 via the check valve 18, it is also connected to the relief passage 21 via the solenoid valve, and the solenoid pulp passage is blocked. In this state, the pressure oil supplied from the m-oil passage 19 to the cylinder 17 via the check valve 18 is sealed in the cylinder 7 as it is, and the piston-like adjusting member 16 is driven upward to reach the upper limit. When the cylinder 17 is locked and the strain/idle valve is opened, the cylinder 17
The pressure oil supplied to the stone-shaped adjustment member 16 is positioned at the lower limit.

Since FIGS. 1 and 2 are configured as described above, in the high-speed operating range, the solenoid valve is closed, and the pressure oil flows from the pressure oil passage 19 through the check valve 18 into the hydraulic cylinder 17. The piston-shaped adjustment member 16 is raised to the upper limit by the pressure of the introduced pressure oil, and the adjustment coil spring 1
5 is compressed to the ultimate state so that it cannot be further compressed and deformed, and the pivot member 14 is fixed at the upper limit.As a result, the rotation of the intake cam 12 causes the rocker arm 13 to move up and down centering on the upper end of the pivot member 14. be swayed.

Therefore, in a high-speed operating range, the valve overlap period is long, so the inertia effect of intake and exhaust is produced, and it becomes possible to increase the output of the engine.

In addition, in a low-speed operating range or a low-load operating range, the solenoid valve is applied by a control signal (not shown), so that the spring force of the adjusting fill spring 15 is greatly reduced compared to the spring force of the valve actuating coil spring 11. However, when the rocker arm 13 is pressed downward by the rotation of the intake cam 12,
The rocker arm 13 is vertically swung around the upper end of the sub-intake valve 8, and only the pivot member 14 is moved up and down, and the sub-intake valve 8 remains closed.

Furthermore, since the sub-exhaust valve 10 is formed similarly to the sub-intake valve 8, the sub-exhaust valve 10 also remains closed.

Therefore, in the low-speed operating range or low-load operating range, the sub-intake and exhaust valves 8 and IO remain closed, and all the air-fuel mixture flows in from the main intake passage 3.
When tlf, , M are increased and the inertia effect is enhanced, exhaust recirculation is reduced, which eliminates poor combustion and improves fuel efficiency and low-speed performance.

In this case, if the cams of the sub-intake valve 8 and sub-exhaust valve 10 are configured to have different cam ridge shapes from those of the main intake valve 7 and main exhaust valve 9 shown in the drawings, and the overlap period is shortened, the above effect can be further improved. be enhanced.

In addition, only the pivot portion of the rocker arm 13 is connected to the pivot member 14.
, Adjustment coil spring] 5. It is composed of a piston-like adjustment member 16 and a hydraulic cylinder 17, and the opening and closing of the sub intake and exhaust valve 8.10 is controlled only by supplying and discharging hydraulic pressure, making the structure extremely simple. , cheap and durable.

In the embodiment shown in FIGS. 1-2, the intake cam 12
is brought into contact with the center of the rocker arm 13, and the pivot member 14
was brought into contact with the other end of the rocker arm 13, but the third
As shown in the figure, the intake cam 12 is connected to the rocker arm 1.
3, and attach the pivot member 4 to the rocker arm 1.
It may be pivoted to the three pins 13a, respectively, and substantially the same effect as the embodiment shown in FIGS. 1 and 2 can be achieved.

Further, in the embodiment described above, the adjustment member 16 is raised and lowered vertically using a hydraulic system, but the adjustment member 16 may be raised and lowered using an electromagnetic system or a mechanical system.

Further, in the embodiment described above, the adjusting member 16 is moved up and down in two steps, but the position of the adjusting member 16 may be adjusted in multiple steps of three or more steps or steplessly using a normal hydraulic, electric, or mechanical position adjustment mechanism. In such an embodiment,
As the engine operating condition changes from a low-speed operating range or low-load operating range to a high-speed operating range, the sub-intake and exhaust valves 8.1
The valve overlap period (6) can be gradually increased from zero or a small value, reducing air-fuel mixture blowback in low-speed or low-load operating ranges, improving not only fuel efficiency but also driving stability. be able to.

Moreover, in such an embodiment, it is possible to provide one intake and exhaust valve each without providing a main intake and exhaust valve, and the intake and exhaust valve mechanism can be further simplified.

As described above, in a four-cycle internal combustion engine that controls the opening and closing timing of intake and exhaust valves, the present invention provides a valve arm, a pivot member for pivotally supporting the rocker arm, and a relative distance between the valve arm and the pivot member. an adjusting member that can be set, and an adjusting spring is interposed in the pivot member and the adjusting member;
In order to appropriately set the relative distance to the pivot member, a mechanism with a simple structure and high durability can be obtained, and the σq closing operation or opening/closing timing of the intake and exhaust valves can be adjusted according to the operating state of the internal combustion engine. Through appropriate control, it is possible to achieve high output in high-speed driving ranges and to improve fuel efficiency and output in low-speed driving ranges or low-load driving ranges.

Although the present invention has been described above in detail with respect to the embodiments shown in the drawings and the embodiments not shown in the drawings, the present invention is not limited to such embodiments and can be modified without departing from the spirit of the invention. The design can be freely modified as necessary.

[Brief explanation of the drawing]

4...Sub intake passage, 5...Main exhaust passage, 6...Sub exhaust passage, 7...Main intake valve, 8...Sub intake valve, 9...Main exhaust Valve, lO・
...Sub exhaust valve, 11...Coil spring for valve operation, 12...Intake cam, 13...Rocker arm, 1
4... Pivot support member, 15... Coil spring for adjustment, 16... Piston-like adjustment member, 17... Hydraulic cylinder, 18... Check valve, 19... Pressure oil passage, pressure・・・
・Solenoid valve, 21...-Relief passage, 22.
...Adjustment screw, Natsuto. Agent Patent attorney Nozomi Ehara (1 person) Figure 3 21U Procedural amendment February 12, 1980 Haruki Shimada, Commissioner of the Japan Patent Office 1 Display of case Relationship to Patent Application No. 149627 of 1980 Patent applicant 4. Agent. 2-12-17 Shinbashi, Minato-ku, Tokyo (Takemoto Pill')
) TaO3-501-26217, as per the attached sheet to be amended.
``This is a longitudinal sectional side view of the main part, and Figure 3 is a longitudinal sectional side view of the main part of another embodiment of the present invention.''

Claims (1)

[Claims] In a four-stroke internal combustion engine that controls the opening and closing timing of intake and exhaust valves, a valve operating spring attached to the valve, a cam that opens and closes the valve, a rocker arm that transmits the operation of the cam to the valve, The rocker arm is characterized by comprising a pivot member for pivotally supporting the rocker arm, an adjustment member capable of appropriately setting a relative distance to the pivot member, and an adjustment spring interposed in the pivot member and the adjustment member. An intake/exhaust valve opening/closing control device for a four-stroke internal combustion engine.