JPS6140882Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a drive device for intake and exhaust valves of an internal combustion engine.

Regarding the valve drive device of the present invention, the second
For convenience, an example of application to an intake valve will be described.

When the engine is operating at low or medium load, the intake flow rate is increased and the swirl in the combustion chamber is strengthened to promote fuel atomization and improve combustion, and during high load operation, the intake resistance is reduced. , when using the device of the present invention to improve output,
Two intake valves are provided, and as shown in Figure 1,
In a configuration in which only the first intake valve is operated during medium load, and both the first intake valve and the second intake valve 3 are operated during high load, a hydraulic chamber 17 is provided between the second intake valve 3 and the rocker arm 2, When the load is low, pressure oil is not supplied and the valve is inoperative, and when the load is high, pressure oil is supplied to the hydraulic chamber 17 to operate the second intake valve.

As a result, unlike a mechanism that mechanically turns on and off the operation of the intake valve, in the device of the present invention, the plunger member softly contacts the valve end of the second intake valve.
No noise is generated, therefore there is less wear, and there is no need to adjust the valve clearance.

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

FIG. 1 is a sectional view showing relevant parts of the valve driving device of the present invention, and FIG. 2 is a detailed sectional view of the valve driving device.

In FIG. 1, reference numeral 4 denotes a cam that rotates with the operation of the internal combustion engine and swings the rocker arm 2. The rocker arm 2 is provided with a three-way switching valve 1, a hydraulic conduit 9 into which pressure oil flows as indicated by the white arrow a, an atmospheric release hole 8, and a cylinder 24. A hydraulic chamber 17 is formed in the cylinder 24, and a plunger member 7 is provided, the lower end of which abuts against the valve end of the second intake valve 3. Details of the three-way switching valve 1 will be described with reference to FIG. 2.

In Figure 2, the locking arm 2 has a threaded portion 1.
A spool valve 6 having a ball seat of the check valve 11 formed at one end thereof is screwed and fixed to the threaded portion 19, and a communication hole 21 is provided near the through hole 18 and one of the through holes. A seal 12 is attached to the portion. One side of the ball of the check valve 11 is supported by a ball receiving spring 13.

The plunger 1 is provided with a notch 20 inside the spool valve 6 that communicates with the through hole 18.
0 is inserted into the plunger 10, a piston 5 is fitted inside the plunger 10, and the piston 5 is inserted inside the plunger 10 where the large end of the piston 5 is disposed.
A spring 14 for biasing the plunger 10 in the direction of the check valve 11 is supported by a spring seat 15, and the spring seat 15 is secured by a snap spring 16.

A liner 22 is inserted below the cylinder 24 of the rocker arm 2, and the plunger member 7 is attached to the liner 22.
2, the stopper ring 23 is slidably fitted into the stopper ring 23.
It will stop you from falling out.

Now, when the second intake valve 3 is not required during low/medium load operation, pressure oil is not supplied and the atmosphere opening hole 8
The hydraulic chamber 17 communicates with the through hole 18, the area around the rod of the piston 5, and the check valve 11, and is open to the atmosphere.
Even if the plunger member 7 swings, the plunger member 7 will not open the second intake valve 3.

In a high-load operating state, when pressure oil a is supplied from a hydraulic source (not shown) to the hydraulic pressure conduit 9, the plunger 10 moves to the left in FIG. 2 along with the piston 5 against the force of the spring 14. The right small diameter part of the notch 20 closes the passage hole 18 of the spool valve 6, and as the rod of the piston 5 moves, the ball of the check valve 11 becomes able to come into contact with the seat. . The pressure oil that has flowed into the spool valve 6 through the communication hole 21 reaches the inside of the plunger 10 through the notch 20, and further reaches the inside of the piston 5.
The water passes around the rod, pushes open the check valve 11, and flows into the hydraulic chamber 17. In this state, the hydraulic chamber 17 is constantly filled with oil due to the action of the check valve 11, and the oil is incompressible, so when the rocker arm 2 is swung by the cam 4, the plunger member 7
The intake valve 3 is pushed, thereby opening the second intake valve 3 and supplying the air-fuel mixture to the combustion chamber through this valve 3.

Next, when the high load operating state is switched to the low/medium load operating state, the supply of pressure oil from the hydraulic pressure passage 9 is stopped. In this state, plunger 1
0 moves to the right together with the piston 5 by the force of the spring 14 until the notch 20 reaches a position facing the through hole 18, and the rod tip of the piston 5 releases the ball of the check valve 11 from the seat.
Then, the plunger member 7 contacts the valve end of the second intake valve 3 and simultaneously slides upward to open the hydraulic chamber 17.
The oil inside is discharged into the cylinder head (not shown) through the open air hole 8 through the open check valve 11, the notch 20 of the plunger 10, and the through hole 18 of the spool valve 6. After this, the hydraulic conduction path 9 is again
Until the air is supplied, the lift of the cam 4 is always absorbed by the sliding movement between the rocker arm 2 and the plunger member 7, and thereby the second intake valve 3 is kept closed.

When the valve drive device of the present invention is adopted, unlike conventional mechanical devices, the contact between the valve end of the second intake valve 3 and the plunger member 7 is damped by hydraulic pressure, so no noise is generated, and therefore wear is also reduced. There is no need to adjust the valve clearance.

Furthermore, when removing the hydraulic pressure, the atmospheric release hole 8 is opened and the check valve 11 is opened at the same time.
Immediately after the oil pressure is removed, that is, immediately after the valve operation state switching command signal is generated, the oil in the hydraulic chamber 17 is immediately released from the atmosphere opening hole 8, so it is possible that the second intake valve 3 is switched between operation and non-operation at this time by mistake. This has the effect of being carried out smoothly without any movement.

In the above description, the second intake valve has been described for convenience, but it goes without saying that the first intake valve and the exhaust valve can also be used as appropriate.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of the valve driving device of the present invention and related parts, and FIG. 2 is a detailed sectional view of the valve driving device. 1. Three-way switching valve, 2. Rotsuka arm,
3. Second intake valve, 4. Cam, 5. Piston, 6. Spool valve, 7. Plunger member,
8. Atmospheric release hole, 9. Hydraulic pressure passage, 10.
Plunger, 11...Check valve, 12...Seal,
13... Ball receiving spring, 14... Spring, 15... Spring seat, 17... Hydraulic chamber, 18... Through hole, 19... Threaded part, 20...
Notch, 21...Communication hole, 24...Cylinder.

Claims (1)

[Scope of utility model registration request] It comprises a cylinder and a plunger member slidably fitted into the cylinder, and constitutes a part of the valve train of an internal combustion engine, and supplies and discharges pressure oil to a hydraulic chamber formed in the cylinder. A valve drive device that operates or deactivates intake/exhaust valves via a plunger member, and is configured to allow pressure oil to flow only in the direction of the hydraulic chamber in the oil passage that supplies pressure oil to the hydraulic chamber. An interposed check valve, an atmosphere opening hole provided in the oil passage upstream of the check valve, an oil passage interposed in the oil passage between the atmosphere opening hole and the check valve, and the atmosphere opening. a three-way switching valve that cuts off communication with the oil upstream from the hole and opens and closes the atmospheric release hole;
A check valve opening mechanism that works in conjunction with the three-way switching valve and forcibly opens the check valve when the three-way switching valve opens the atmosphere opening hole; A valve drive device characterized by being equipped with a hydraulic response mechanism that operates a switching valve.