JPS628323Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a valve operation stop mechanism for an internal combustion engine.

As an example of an internal combustion engine, two intake valves are provided,
Some engines operate only the first intake valve when the load is low or medium, and operate the first intake valve and the second intake valve when the load is high to increase the output. Further, in a multi-cylinder internal combustion engine, it is being considered to cut off some of the cylinders during operation or to restart them depending on the operating conditions in order to save fuel consumption. That is, since it is not necessary to operate all the cylinders during low-speed running, the intake and exhaust valves of some of the cylinders are rendered inactive to deactivate the cylinders.

As a valve operation stop mechanism used in the above-mentioned case, Japanese Patent Application Laid-Open No. 55-14914 and Japanese Patent Application Laid-open No.
The one shown in Japanese Patent No. 52-56212 has been proposed in the past. However, according to the former, there is a part that uses hydraulic pressure in the power transmission path that transmits the cam lift to the valve, so the valve lift amount changes due to oil leakage, making it impossible to obtain the desired cam lift. In addition, the latter had the drawback that it was extremely unreliable as a valve train for OHC engines because the fulcrum of the rocker arm was equipped with equipment for valve operation and stop. .

The present invention was proposed in view of the above, and includes a rocker arm that is swingably fitted to a rocker shaft, a first cylinder portion provided on the rocker arm, and a rocker arm that is swingably fitted to a rocker shaft. A plunger that is slidably fitted and comes into contact with the valve or cam, a spring that biases the plunger in the valve opening direction, and a second rocker arm provided on the rocker arm.
a cylinder part, a piston disposed in the second cylinder part that cooperates with the second cylinder part to form a hydraulic chamber and is driven according to the supply and discharge of hydraulic pressure to the hydraulic chamber, and a connecting part to the piston. a stopper that is movable with the piston and takes a first position where it engages with the plunger to restrict sliding of the plunger or a second position where it does not engage with the plunger and allows sliding of the plunger; , and an oil control valve that is installed in the oil passage communicating with the hydraulic chamber and switches the supply and discharge of hydraulic pressure to the hydraulic chamber, and the stopper moves together with the piston to its position in response to the hydraulic pressure supply and discharge switching operation of the oil control valve. A valve operation/stopping mechanism characterized in that the valve is switched between a first position and a second position, whereby sliding of the plunger is restricted or permitted and the valve is activated or deactivated. The gist is:

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a partial sectional view showing the configuration of an embodiment of the present invention, Fig. 2 is a sectional view taken along the line X-X in Fig. 1, and Fig. 3 is a schematic perspective view of another valve operation stop mechanism. It is.

In Fig. 1, reference numeral 1 denotes a rocker arm that is fitted into a rocker shaft (not shown) and swings.At the upper part of the rocker arm, there is an oil passage 2 through which hydraulic oil is guided from the sliding part of the rocker shaft, and hydraulic oil is supplied from this oil passage 2. A cylinder part and a hydraulic piston 3 which is housed in the cylinder part and cooperates with the cylinder part to form a hydraulic chamber and whose position is controlled according to the state of supply of hydraulic oil to this hydraulic chamber are provided. A stopper 9 is attached to the end of the rod 3'.
Further, a cylinder 4 is attached to one end of the rocker arm 1, and a plunger 6 is provided inside the cylinder 4, which is biased by a spring 7 in a direction to open a valve 8.
The lower end of the plunger 6 is in contact with the upper end of the stem of the valve 8 .

The cylinder 4 is provided with a spring 15 at its center, and a notch 16 is formed in the upper part of the spring 15 into which the stopper 9 is fitted when it is slid to the right in FIG. 1 by the hydraulic piston 3. A double nut 5 is provided, and the stopper 9 is adjusted to slide smoothly between the nut 5 and a spring 15.

As shown in FIG. 2, the stopper 9 is U-shaped and has a relief 17 formed at its tip when the plunger 6 slides up and down.

Now, depending on the operating situation, when operating the valve,
The engine signal B is the control box 10.
On the other hand, engine oil A is controlled by the oil control valve 11 in response to a command from the control box 10, and is sent from the rocker shaft sliding part to the rocker arm 1 via the rocker shaft.
the hydraulic piston 3 via the oil passage 2.
Slide it to the right in the diagram. At the same time, the stopper 9 connected to the rod 3' slides to the right and moves to the position shown in two-dot chain line in FIG. Then, plunger 6
The head of is held down by the stopper 9, and the plunger 6
does not slide, and the valve 8 operates in conjunction with the swinging of the rocker arm. When the hydraulic pressure supply is stopped, the hydraulic piston 3 is returned together with the stopper 9 by the return spring 18, so that the plunger 6 begins to slide again and the operation of the valve 8 is stopped.

In the other valve actuation stop mechanism shown in FIG. 3, notches are formed equally in the upper part of the plunger 6', while a trigger 14 is attached to the hydraulic piston 3, and one end of the trigger 14 is connected to the plunger 6'. It engages with a pin 13 attached to one end of a stopper 9', which is provided with a spline 12 that fits into a notch in the stopper 9'.

When stopped, the hydraulic piston 3 slides to the right in Figure 3 due to hydraulic pressure and rotates the stopper 9'.
The upper notch of the plunger 6' is connected to the spline 1.
2 and slides, and the valve operation stops. When the hydraulic pressure supply is stopped, the hydraulic piston 3 is returned by the return spring 18, so that the plunger 6' comes into contact with the spline 12 again and swings together with the rocker arm, and the valve starts operating.

According to the present invention, in an engine equipped with a rocker arm that is swingably attached to a rocker shaft, most of the valve operation/stopping mechanism consisting of a plunger, stopper, piston, etc. is housed in the rocker arm, and the valve actuation/stopping mechanism is housed in the rocker arm. By adopting a hydraulic + mechanical method as the switching drive method, it is possible to manufacture compactly and inexpensively without making any major changes to the conventional structure, and provides a highly reliable and durable valve operation stop mechanism. It can be done.

In constructing the valve operation stop mechanism of the present invention, a cylinder may be provided at the end of the rocker arm on the cam contact side, and a plunger may be accommodated in the cylinder so that the tip of the plunger contacts the cam.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing the configuration of an embodiment of the present invention, Fig. 2 is a sectional view taken along the line X-X in Fig. 1, and Fig. 3 is a schematic perspective view of another valve operation stop mechanism. It is. 1...Rotcher arm, 2...Oil passage, 3...Hydraulic piston, 3'...Rod, 4...Cylinder,
5...double nut, 6,6'...plunger,
7, 15, 17...Spring, 8...Valve, 9,
9'...Stopper, 10...Control box, 11...Oil control valve, 1
2. Spline, 13. Pin, 14. Trigger, 16. Notch, 17. Relief, 18. Return spring.

Claims (1)

[Scope of utility model registration request] A rocker arm is fitted to the rocker shaft so as to be able to swing, and a first rocker arm is provided on the rocker shaft.
a cylinder part, a plunger which is slidably fitted into the first cylinder part and comes into contact with the valve or cam, a spring which biases the plunger in the valve opening direction, and a second cylinder part provided on the rocker arm. cylinder part, and a second cylinder part disposed in the second cylinder part.
A piston that cooperates with the cylinder part to form a hydraulic chamber and is driven according to the supply and discharge of hydraulic pressure to the hydraulic chamber, and a connecting part to the piston, which is movable together with the piston, and which engages with the plunger. a stopper that takes a first position to restrict sliding of the plunger or a second position that disengages from the plunger and allows sliding of the plunger, and a stopper that is provided in an oil passage communicating with the hydraulic chamber to the hydraulic chamber The stopper moves together with the piston in response to the oil pressure supply/discharge switching operation of the oil control valve, and its position is switched between a first position and a second position. A valve operation stop mechanism, characterized in that the valve is actuated or deactivated by regulating or allowing sliding of the plunger.