JPH0143443Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is used for cylinders that can be deactivated in a multi-cylinder internal combustion engine with a variable number of cylinders, and can prevent cam operation from being transmitted to the intake and exhaust valves. Related to improvements in valve train mechanisms for internal combustion engines.

[Conventional technology]

When an internal combustion engine is idling or operating under low load, less fuel is supplied to the combustion chamber, so the combustion chamber cannot be kept at an appropriate heating state, reducing combustion efficiency and fuel consumption. .

Therefore, during the above-mentioned operation, variable cylinder number engines have been developed that reduce the number of cylinders that supply fuel and increase the amount of fuel to the operating cylinders to improve combustion efficiency and reduce fuel consumption. Are known. In such an internal combustion engine, if the intake and exhaust valves of the cylinders to which fuel supply is stopped are also stopped, the pumping loss will be reduced, the engine load will be lightened, and fuel consumption will be more effectively reduced. .

Incidentally, the following has been devised as a valve operating mechanism for an internal combustion engine that stops the operation of intake and exhaust valves.

As shown in FIG. 1A, this mechanism has a rocker arm 3 with a rocker shaft 4 as its rotation axis, and an axis b that is vertically downwardly spaced a distance e from the shaft center a of the rocker shaft 4 (eccentric). attached to the rocker shaft 4 so as to be rotatable with respect to each other via an inner bush 1 and an outer bush 2 having an axis c vertically downward and spaced apart (eccentric) by a distance e from the axis b of the inner bush 1; The eccentric inner and outer bushes 1, 2 of the rocker arm 3 are rotatably controlled by a link device 10 and a piston device 20, as shown in FIG. 1B. This link mechanism 10 includes an inner transmission member 11 integrally connected to an inner bush 1 as shown in FIG. 1B.
an outer transmission member 12 that is slidably fitted into the rocker shaft 4 and connected to a piston 13 protruding from the outer bushing 2 through a long groove 14; and an axis a of the rocker shaft 4 of the inner and outer transmission members 11, 12. It is comprised of links 16 and 17 of equal length that are connected to a connecting pin 15 provided at a location equidistant from , and are pulled upward while rotating about the axis a. The other ends of the links 16 and 17 are connected by a pin 18 at the same fulcrum and connected to a rod 21 of a piston device 20.

This piston device 20 guides high-pressure air from an air introduction pipe 22 to a pipe 24 or a pipe 25 via a switching valve such as a pilot type solenoid valve 23.
When air is introduced into the tube 25, the outlet 26 communicates with the atmosphere and the rod 21 is pushed down, and when air is introduced into the tube 25, the outlet 27 communicates with the atmosphere and the rod 21 is pulled up. ing. Then, in the state shown in FIG. 1B where the piston device 20 is pushing down the rod 21, a downward force acts on the link device 10 connected to the piston device 20, and the inner and outer bushes 1 and 2 are pushed down as shown in FIG. 1A. In this position, that is, in a state where the eccentric direction is on the cylinder side (not shown), the valve operating motion of the cam 6 attached to the camshaft 5 is transmitted from the rocker arm 3 to the intake/exhaust valves 9 via the tappet 7 and push rod 8. In addition, when the piston device 20 is pulling up the rod 21, the link device 10 rotates the inner and outer bushes 1 and 2 in the directions of arrows P and Q in FIG. 1A, and the rocker arm 3 moves as shown in FIG. 1C. In the state where it is pulled upward, that is, the eccentric direction of the inner bush 1 and the outer bush 2 are arranged in the direction of the locker arm 3 and in opposite directions to each other.The push rod 8 is pushed upward by the spring, and the push rod 8 and the tappet An air gap will be created between them, and the valve operating motion of the cam 6 will be absorbed by this air gap and will not be transmitted to the intake/exhaust valves 9.

The valve train of the internal combustion engine configured as described above uses two inner and outer bushes eccentrically mounted on the rocker shaft 4, so the rocker arm 3 does not move horizontally but only in the vertical direction. Furthermore, there is no separation between the rocker arm 3 and the push rod 8, and the amount of movement of the rocker arm 3 is sufficient, making it an extremely excellent means for stopping the operation of intake and exhaust valves.

[The problem that the idea aims to solve]

By the way, the cam lift makes the push rod 8
moves in the direction of arrow R in Fig. 2 and locks the locking arm 3.
When rotated in the direction of arrow S, that is, in the direction in which the intake/exhaust valve 9 opens, the outer bush 2 (outer bush) tries to rotate in the same direction as the arrow S due to the frictional force with the rocker arm.

In this case, if the link 17 connected to the outer bush 2 is on the side of the intake/exhaust valve 9, the piston 28 of the piston device 20 comes into contact with the cylinder 32 and is regulated, so the rotation of the outer bush 2 is prevented. Therefore, no lift loss occurs in this valve train. However, when the link 17 is on the push rod 8 side as shown in FIG. 3, the link 17 acts in a direction to push up the piston 28 of the piston device 20, pushing the piston 28 upward. As a result, a lift loss occurs every time the rocker arm 3 pushes the exhaust valve 9, and especially when the pressure of the high-pressure air supplied to the piston device 20 is insufficient, the outer bush 2 may become twisted by the rocker arm 3. There is a problem that the lift amount of the intake/exhaust valve 9 decreases.

This idea moves the rocker arm away from the intake/exhaust valves to stop the intake/exhaust valves, and when the intake/exhaust valves are operated, the swinging action of the rocker arm generates a force in the direction of separation, causing the intake/exhaust valves to An object of the present invention is to provide an excellent valve operating mechanism for an internal combustion engine that is free from the risk of insufficient lift of intake and exhaust valves, that is, lift loss.

[Means to solve the problem]

The structure of the valve mechanism for an internal combustion engine according to the present invention for achieving the above object is such that an inner bush whose center is eccentric with respect to the axis of the rocker shaft is inserted into the rocker shaft, and an inner bush whose center is eccentric with respect to the axis of the inner bush is inserted into the rocker shaft. Insert an outer bushing whose center is eccentric, fit a rocker arm into the outer bushing, and connect the working end of the piston-driven link to the rocker shaft, the outer bushing to the intake/exhaust valve side, and the inner bushing to the cam side. When the piston is mounted and the piston is pushed down, the two bushes rotate in opposite directions, so that the eccentric direction of both bushes faces the cylinder side.

〔Example〕

Embodiments of this invention will be described below with reference to the drawings.

FIG. 4 is a structural explanatory diagram showing the valve operating mechanism on the side of the intake/exhaust valve 9 of this invention.

In this invention, the connecting pin 15a protruding from the inner transmission member 11, which is integrally connected to the inner bush 1 disposed on the rocker shaft 4, is located on the push rod 8 side with respect to the rocker shaft 4, that is, a cam not shown in FIG. The link 16 is connected to the side. Also, a pin 1 protruding from an outer bush 2 disposed on the inner bush 1 is provided.
3 through a long groove 14, the outer transmission member 12 extends toward the intake/exhaust valve 9 side, and a connecting pin 15b is protruded from the rocker shaft 4 at a position corresponding to the connecting pin 15a on the intake/exhaust valve 9 side. Link 1 to this
Connect 7.

These links 16 and 17 are connected by a pin 13 protruding from the rod 21 to form a link device 10'.
The link device 10' is connected to the piston device 20. The piston device 20 may be completely the same as the conventional one.

In the internal combustion engine valve mechanism of this invention constructed in this way, the rocker arm 3 is rotated in the direction of the arrow W by the thrusting force shown by the arrow V of the push rod 8 on the intake/exhaust valve 9 side when the intake/exhaust valve is in operation. This causes the intake/exhaust valve 9 to open, and with this rotation, the outer bush 2 also receives a force in the same direction. Since this force acts on the piston 28 toward the lower end of the cylinder 32 via the link device 10', no lift loss occurs in this valve operating mechanism.

[Effects of the Invention] Since the valve mechanism for an internal combustion engine of the present invention is configured as described above, the following effects can be obtained.

That is, when stopping the operation of the intake/exhaust valve during low-load operation, the rocker arm can be separated from the shaft end of the intake/exhaust valve by simply activating the fluid pressure-driven link and rotating the outer bush and the inner bush by a predetermined angle. Furthermore, when operating the intake and exhaust valves, the strong frictional force that the rocker arm receives when opening the intake and exhaust valves causes the rocker arm to be pulled downwards, that is, to pivot the rocker shaft concentrically. The valve mechanism is capable of eliminating lift loss by rotating the outer bush and the inner bush in the direction in which they are held in the desired position.
It can be provided with a simpler mechanism and higher reliability.

[Brief explanation of drawings]

Figure 1A is a side view of the rocker arm attached to the rocker shaft via a double eccentric bushing; Figure 1B is an explanatory diagram of the configuration of a conventional variable cylinder internal combustion engine valve mechanism using the rocker arm of the same A, Figure 2 is an explanatory diagram showing the configuration of one cylinder of the conventional valve mechanism, and Figure 3 is an explanatory diagram of the configuration of a conventional valve mechanism for one cylinder. FIG. 2 is a side view of the rocker arm on the exhaust valve side seen from the direction of arrow A, and FIG. 4 is an explanatory view showing the configuration of the valve operating mechanism on the exhaust valve side of this invention. 1... Inner bush, 2... Outer bush, 3... Rocker arm, 4... Rocker shaft, 7... Tappet, 8... Push rod, 9
...Intake/exhaust valve, 10...Link device, 16,1
7... Link, 20... Piston device, 21...
Rod, 23... Solenoid valve, 28... Piston.

Claims (1)

[Scope of utility model registration request] An inner bush whose center is eccentric with respect to the axis of the rocker shaft is fitted into the rocker shaft, an outer bush whose center is eccentric with respect to the axis of the inner bush is fitted into the inner bush, a rocker arm is fitted into the outer bush, and the locker arm is fitted into the outer bush. Attach the operating end of the link to the rocker shaft, to the outer bush on the intake/exhaust valve side, and on the inner bush to the cam side,
When the piston is pushed down, the two bushes rotate in opposite directions, and both of the bushes are installed so that the eccentric direction faces toward the cylinder.