JPH0329528Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an improvement of a valve stop device that switches the intake and exhaust valves of an engine between operation and non-operation by moving up and down the rock shaft, which is the rotating shaft of the rock arm. .

[Prior art]

BACKGROUND ART In recent years, in multi-cylinder engines, it has been put into practical use to reduce the number of operating cylinders by stopping the operation of specific cylinders when the engine is running at low speed and under light load, thereby improving fuel efficiency in the light load range.

In such a variable cylinder engine, in order to prevent the inactive cylinder from becoming a load on the active cylinder, the fuel supply is cut off and the intake and exhaust valves of the inactive cylinder are stopped at the same time. There is.

Various mechanisms have been proposed for stopping valve operation, and one of them is the mechanism disclosed in Japanese Patent Application Laid-open No. 57-65805. This mechanism is shown in Figures 1 to 3.
As outlined in the figure, the valves of the deactivated cylinders are stopped by pulling up the rocker shaft.

A rocker shaft 2 that rotatably supports a rocker arm 1 of a cylinder that can be deactivated is provided with a protruding rotary shaft 3 having an axis Q eccentric to its axis P. It is pivotally supported by the cylinder head 4. A lever 5 is fixed to one end of the rotating shaft 3.
The free end 5a of the actuator 6 is rotatably pin-coupled to the rod 6a of the actuator 6.

Therefore, when the rod 6a is moved by the actuator 6, the rotation shaft 3 is moved via the lever 5.
rotates, and the rock shaft 2, which has become an eccentric cam with respect to the rotation axis 3, rotates around the rotation axis 3,
As a result, the rocker arm 1 moves up and down. That is, when the rock shaft 2 rotates toward the top dead center, the rock arm 1 rises and the intake and exhaust valves become inoperable, and when the rock shaft 2 rotates toward the bottom dead center, the rock arm 1 descends and returns to its normal position. Sucking,
The exhaust valve is activated.

However, in the past, the efficiency of the rock shaft 2, which was an eccentric cam, was that the rotating shaft 3 was aligned vertically with respect to the horizontal line L passing through the axis Q of the rotating shaft 3, as shown in FIG. Since the raised position and lowered position of the rock shaft 2 were to be on the same vertical line V by rotating the rock shaft 2 by an angle θ, the rock shaft 2 was rotated in the direction of arrow A to move the rock shaft 2 to the solid line position (valve actuation). position), the spring force when the valve is opened acts on the rocker shaft 2 via the rocker arm 1 in the direction of arrow B. The force exerted by this spring is a force in the direction of arrow C with respect to the rotating shaft 3, and is a force that opposes the force in the direction of arrow A by which the actuator 6 attempts to rotate the rocker shaft 2 to the lowered position. Therefore, a strength problem arises in the actuator 6, the rod 6a, and the lever 5, and the holding force of the actuator 6 when the valve is operated needs to overcome the spring force, so the actuator 6 must be made strong. There is also the issue of being indispensable.

[Purpose and structure of the invention]

The purpose of the present invention is to solve the problems of the conventional valve stop device, and to provide a valve stop device configured to stop the valve operation by raising and lowering the rock shaft using an eccentric rotation shaft attached to the rock shaft. , an excellent valve stop that reduces the reaction force of the spring force against the rotation shaft when the valve is operated, reduces the strength of the lever and actuator connected to this rotation shaft, and reduces the actuator's operating force. The purpose is to provide equipment.

The valve stop device of the present invention that achieves the above object includes a rocker arm for a deactivable valve that is pivotally supported on a rocker shaft of an engine, a rotating shaft eccentrically attached to the rocker shaft that is pivotally supported on a cylinder head, and The movement of the axis of the rocker shaft due to the rotation of the rocker arm moves between the axis of the rotating shaft and the cylinder, and the operating position of the rocker arm is near the bottom dead center where the axis of the rocker shaft is closest to the cylinder. an actuator that is located on the opposite side of the bottom dead center with respect to the operating position and moves between a non-actuating position that is further away from the cylinder from the bottom dead center, and moves the rocker shaft between the operating position and the non-actuating position; , which is attached to a rotating shaft.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings, in which the same members as in FIGS. 1 to 3 are designated by the same reference numerals.

FIG. 4 is a schematic diagram showing the configuration of the valve stop device of the present invention.

Also in the valve stop device of the present invention, the rocker shaft 2 that rotatably supports the rocker arm 1 of the deactivable cylinder is provided with a protruding rotary shaft 3 having an axis Q eccentric to the shaft center P thereof. The rocker shaft 2 is an eccentric cam with respect to the rotating shaft 3. This rotating shaft 3 is supported by the cylinder head in the same manner as described above, and a lever 5 is fixed to one end of the rotating shaft 3.
The free end 5a of the actuator 6 is rotatably pin-coupled to the rod 6a of the actuator 6. 8 indicates an intake or exhaust valve, and 9 indicates a push rod.

In the valve stop device of the present invention, when the valve 8 is in operation, the rock shaft 2, which serves as the eccentric cam,
is the bottom dead center of the eccentric cam (the position of the two-dot chain line in Fig. 5)
(the solid line position in Figure 5), that is, the operating position is on the left side of the figure with respect to the two-dot chain line L passing through the axis Q of the rotating shaft 3 and the axis P of the rocker shaft 2. The rotation shaft 3 and the lever 5 are positioned, and a stopper 7 is provided below the lever 5 for setting this position. Further, in this state, the rod 6a protrudes from the actuator 6.

The position of the locking shaft 2 at which the valve 8 is inactivated is the position shown by the broken line in FIG. It is set so that it is in the inoperative position on the right side of the figure. The positioning of the broken line position of Rotsuka shaft 2 is as follows.
This is done by the actuator 6, and in this state the rod 6a is recessed into the actuator 6. Further, the positioning of the rod shaft 2 at the broken line position may be performed by such an actuator 6, but the actuator 6 of the rod 6a
Alternatively, a stopper 7' (position shown by the two-dot chain line in FIG. 4) may be installed in the direction of movement, and the lever 5 may be brought into contact with this stopper 7'.

That is, driven by the actuator 6, the rocker shaft 2 moves between an operating position close to the bottom dead center and a position in a non-operating region away from the bottom dead center. The locker arm 1 is rotated by passing over the cylinder side (not shown) of the rocker arm 1 and changes the rocker arm 1 between an operating state and a non-operating state.

In the valve stop device of the present invention configured as described above, when operating the valve 8, the rod 6a is projected from the actuator 6 in the direction T.
When the lever 5 is moved, the rotating shaft 3 rotates in the direction of arrow A, and the rocker shaft 2, which is an eccentric cam with respect to the rotating shaft 3, rotates around the rotating shaft 3. The rotation of the rocker shaft 2 continues even beyond the bottom dead center of the eccentric cam, and the rotation of the rocker shaft 2 stops with the lever 5 in contact with the stopper 7. At this position, the rocker arm 1 comes into contact with the stem end 8b of the valve 8, and the valve 8 is opened by the pushing up action of the push rod 9.

During the opening operation of the valve 8, the rocker arm 1 receives a reaction force in the direction of arrow D from the spring 8a of the valve 8 (Fig. 4), and this reaction force is applied to the rocker shaft 2.
It acts as a force in the direction of arrow B (FIG. 5), and acts as a force to rotate the rotation shaft 3 in the direction of arrow E. That is, the spring 8 when the valve 8 is activated
The force in the direction of arrow E caused by a causes the rotary shaft 3 to actuate the valve 8 by the actuator 6.
Since this force acts in the same direction as the direction, this force is received by the stopper 7 and is not transmitted to the actuator 6 through the rod 6a. Therefore, the actuator 6, which rotates the rotation shaft 3 to put the valve 8 into the operating state, does not need to have a large capacity in consideration of the reaction force caused by the spring 8a.

On the other hand, when the valve 8 is to be inactivated, the actuator 6 may be operated so that the rod 6a is recessed into the actuator 6 in the device of the present invention. When the rod 6a is recessed into the actuator 6, the rotation of the lever 5 causes the rocker shaft 2 to rotate in the direction of arrow F, and the rocker shaft 2, which is an eccentric cam with respect to the rotating shaft 3, moves from the solid line position to its bottom dead center position. (double-dashed line) and move to the position of the broken line.

As a result, the rocker shaft 2 separates from the valve 8 and rises, so that even if the push rod 9 pushes up the other end of the rocker shaft 2, the valve 8 will not open. The raised position (broken line) of the rock shaft 2 is the lowered position (solid line) of the rock shaft 2.
Although not on the same vertical line, since the valve 8 is inactive when the rocker shaft 2 is raised, there is no problem at all even if the rocker shaft 2 moves a small distance in the horizontal direction when it moves up and down.

In this manner, in the valve stop device of the present invention, the reaction force due to the spring does not act on the actuator when the valve is operated, so no unnecessary load is applied to the actuator and there is no need to make it larger than necessary.

[Effect of idea]

As explained above, the valve stop device of the present invention is configured so that the reaction force that the actuator that rotates the rock shaft receives when actuating the stoppable valve acts in the same direction as the output of the actuator. It is possible to prevent unnecessary loads from being applied to the actuator, to rotate the rocker shaft with a small output, and to achieve the effect that the actuator can be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of a conventional valve stop device, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. 3 is an explanatory diagram showing the movement of the lock shaft of the valve stop device in FIG. FIG. 4 is a perspective view showing the structure of the valve stop device of the present invention, and FIG. 5 is an explanatory view showing the movement of the rocker shaft in the valve stop device of the present invention. 1...Rotsuka arm, 2...Rotsuka shaft,
3... Rotating shaft, 4... Cylinder head, 4... Cylinder head, 5... Lever, 6... Actuator, 7... Stopper, 8... Valve.

Claims (1)

[Scope of utility model registration request] A rocker arm for a deactivable valve is pivotally supported on the rocker shaft of the engine, and a rotating shaft eccentrically attached to the rocker shaft is pivotally supported on the cylinder head. The actuating position of the loca arm is near the bottom dead center, where the axis of the rocker shaft is closest to the cylinder, passing between the axis of the driving shaft and the cylinder, and the actuating position of the loca arm is on the opposite side of the bottom dead center with respect to the actuating position. , and an actuator that moves between the bottom dead center and a non-operating position away from the cylinder, and that moves the rocker shaft between the operating position and the non-operating position, the actuator being attached to the rotating shaft.