JPH0541803B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine valve train system, and more particularly to a valve control device for an engine valve train system for activating or stopping the valves.

Conventionally, a compound intake type engine (CIS engine) is equipped with a primary intake valve that operates throughout the entire engine speed range, and a secondary intake valve that stops operating in the low engine speed range and starts operating in the high engine speed range. ) and cylinder deactivation engines that can temporarily stop the operation of the intake and exhaust valves for a specific cylinder to put that particular cylinder into a cylinder deactivation state.

In such a CIS engine or a cylinder-deactivated engine, a valve actuation/stopping device is required to actuate or stop the valves of the engine valve system.

The present invention was created under these circumstances, and provides a valve control device for an engine valve system that has a simple configuration and can easily and reliably switch between valve operation and valve stop. The purpose is to

Therefore, in the engine valve train, the valve control device for the engine valve train of the present invention has an intermediate part connected to the lower surface of the cam in order to transmit the valve driving force from the cam provided above the stem part of the valve. A swing arm is provided, the tip of which is brought into contact with the upper surface of the stem portion of the valve, and one end of the swing arm is provided with a zero latch adjuster that is provided in the cylinder head to control the operation of the valve. A plunger is pivotally connected to the cylinder head and the other end is slidably inserted into the base end of the swing arm, and a locking mechanism locks the plunger to the swing arm when the valve is actuated. It is characterized by the fact that

Hereinafter, a valve control device for an engine valve train as an embodiment of the present invention will be explained with reference to the drawings. The figure is a schematic configuration diagram showing a partially cutaway plan view, Figure 3 is a schematic diagram showing the valve when it is in operation, and Figure 4 is a schematic diagram showing the valve when it is stopped. be.

In this embodiment, each cylinder has two intake valves and two intake valves for each cylinder.
DOHC (Double
This section describes an engine with a valve train of the Over Head Cam) type. This engine has a primary intake system and a secondary intake system.The primary intake system is equipped with a primary intake valve that operates over the entire engine speed range, and the secondary intake system is equipped with a primary intake valve that operates over the entire engine speed range. It is equipped with a secondary intake valve that stops operating in the engine speed range and starts operating in the high engine speed range.

In the engine valve system of this embodiment, the primary intake valve, secondary intake valve, and two exhaust valves are opened and closed by cams via swing arms whose base ends are pivotally connected to the cylinder head side. However, as shown in Figures 1 and 2, 2
The swing arm 3, which opens and closes the secondary intake valve 1 with the cam 2, has its middle portion abutting the lower surface of the cam 2, and its tip end that is connected to the stem portion of the secondary intake valve 1 (hereinafter referred to as “valve stem portion”). ) is in contact with the upper surface of 1a.

Note that the swing arm for the primary intake valve and the exhaust valve also has its middle part in contact with the lower surface of the cam, and its tip end in contact with the upper surface of the valve stem, similar to the swing arm 3 for the secondary intake valve. are in contact with each other.

In addition, the swing arm 3 and other swing arms are guided by a guide formed on the cylinder head 7 side (the guide for the swing arm 3 is indicated by reference numeral 21).
It is guided so that it can be swung.

Further, reference numerals 22 and 23 in FIGS. 1 and 2 respectively indicate spring receivers, and these spring receivers 2
Valve springs 24 and 25 are interposed between 2 and 23 to bias the valve in the valve closing direction.

By the way, the secondary intake valve swing arm 3 is provided with a valve operation stop mechanism M. That is, a cylinder 4 is attached to the swing arm 3, and a bottomed cylindrical plunger 5 is slidably fitted into the cylinder 4. The plunger 5 is pressed downward as shown in FIG. It is pivotally connected to the lash adjuster 8.

Further, on the cylindrical wall of the cylinder 4, there are two long holes located directly above the upper end (other end) of the plunger 5 when the plunger 5 is at the lowest position relative to the cylinder 4 (the position shown in the figure). Holes 4a are provided facing each other, and a lock plate 9 constituting the locking mechanism E is inserted into these long holes 4a.

At the tip of this lock plate 9, there are 2
A crotch fork portion is formed, and as shown in FIG.
a, and the part near the tip thereof is slightly wider than the outer diameter of the plunger 5.
It is formed as.

In addition, the swing arm 3 includes a cylinder 10.
and a piston 11 sliding inside this cylinder 10.
A hydraulic actuator 14 is provided, which includes a return spring 13 that is interposed between the piston 11 and the spring receiver 12 and presses the piston 11 upward in FIG.

The piston 11 and the lock plate 9 are connected, and the connecting portion 15 is as follows.

That is, a cylindrical connecting member 16 having a rectangular cross section perpendicular to the sliding direction of the piston 11 is fixed to the outer end of the piston 11, and is provided on the piston 11 side of the lock plate 9 and has a substantially C-shape. A hook-shaped portion 17 surrounds the connecting member 16 with a gap along the sliding direction of the piston 11, thereby connecting the lock plate 9 and the piston 1.
1 are connected with a gap.

Furthermore, the piston 11 is connected to a timing lever 18.
Its operation is controlled by In other words, the timing lever 18 is set so that the swing arm 3 is in the fourth position.
Only when the plunger 5 reaches the C position shown in the figure (the position of the swing arm 3 in which the plunger 5 is relatively pushed into the swing arm 3), the protruding rod 1
9 allows the piston 11 to move in the direction of pushing out the lock plate.

The reason why the piston 11 is moved in such a timely manner is as follows. In other words, since it takes a certain amount of time to move the lock plate 9 by moving the piston 11, the movement can be started immediately after the cam crest leaves the swing arm slipper surface, and the next time the cam crest comes, it is completely moved. If the movement is not completed, the lock plate 9
This is because problems such as destruction may occur.

Since the lock plate 9 and the actuator 14 that drives it are configured as described above, when pressure oil is supplied to the oil chamber 20 of the actuator 14, the lock plate 9 is made to protrude at the required timing, and the lock plate 9 The narrow gap 9a is located above the plunger 5, so that the plunger 5 is locked to the lock plate 9 and the valve can be operated. That is, when the cam 2 rotates in this state, the swing arm 3 swings between the positions indicated by symbols A and B in FIG. The state can be realized.

Furthermore, when the oil is discharged from the actuator 14, the lock plate 9 is retracted at the required timing by the action of the return spring 13, and the wide gap 9b of the lock plate 9 is positioned above the plunger 5. As a result, the plunger 5 slides within the cylinder 4 as the swing arm 3 swings, thereby realizing the valve stop state.

That is, when the cam 2 rotates in this state,
Accordingly, the swing arm 3 swings between the positions indicated by symbols A and C in FIG.
Since a does not move up or down at all, the valve can be stopped.

Note that the supply and discharge control of pressure oil to the actuator 14 is performed by detecting engine rotation speed information and load information.
Based on these detection results, actuator 1
A controller (CPU) that outputs a control signal to a three-way switching solenoid valve that is installed in the oil passage to the oil chamber 20 in No. 4 and switches between the pump side and the reservoir side.
It is carried out by.

With the above-mentioned configuration, oil is discharged from the oil chamber 20 of the actuator 14 in the low engine speed range, so the wide gap 9b of the lock plate 9 is located above the plunger 5, and thus the two
The secondary intake valve 1 has stopped operating.

Note that the primary intake valve maintains its operating state in this case as well.

By the way, when the engine reaches a high speed range, pressure oil is supplied to the actuator 11. Thereafter, the timing lever 18 is disengaged from the piston 11 at a predetermined timing, and the lock plate 9 is pushed.
It is on standby in a state where it is pressed against the plunger 5. When the cam 2 rotates further and the swing arm 3 comes to the position shown by the symbol A in FIG. 3 to prevent it from sliding. As a result, the secondary intake valve 1 starts operating.

In this case as well, the primary intake valve will not be closed.

In order to stop the operation of the secondary intake valve 1 again, it is sufficient to drain the oil from the actuator 14. As a result, the piston 11 is pushed by the return spring 13 and tries to move in the direction of pulling out the lock plate 9. However, when the cam ridge is pushing the swing arm 3 (see position B in Fig. 3), the plunger 5 moves toward the lock plate 9. Since I am pushing 9,
Lock plate 9 cannot be removed.

Next, when the cam ridge leaves the swing arm 3 and comes onto the cam base circle surface, the force of the plunger 5 to push the lock plate 9 disappears, so the lock plate 9 is released by the force of the return spring 13. After that, when the cam 2 rotates further and the cam peak is on the slipper surface of the swing arm 3, the plunger 5 slides freely inside the cylinder 4, so the swing arm 3 uses the zero lash adjuster 8 as a fulcrum. , moves from the position indicated by the symbol A to the position indicated by the symbol C in FIG. As a result, the secondary intake valve 1 does not lift at all and enters a valve stopped state. Even in this case, the primary intake valve continues to operate.

In this way, in the low engine speed range, the operation of the secondary intake valve 1 is stopped and only the primary intake valve is operated, which improves combustion by strengthening swirl and improves torque at low speeds. In addition, in the high engine speed range, the secondary intake valve 1 is operated in addition to the primary intake valve, so the valve opening time area can be increased and the output can be improved. be able to.

Furthermore, switching between activation and deactivation of the secondary intake valve 1 can be easily and reliably performed.

Please note that this device is SOHC (Single Over Head)
In addition to being applicable to valve control of engine valve train systems of the Cam) type, it can also be applied to engines with cylinders inactive.

As described in detail above, according to the valve control device for an engine valve train of the present invention, in the engine valve train, the intermediate part is a swing arm that is in contact with the lower surface of the cam and whose tip is in contact with the upper surface of the stem of the valve, and a zero latch that has one end attached to the cylinder head to control the operation of the valve. A plunger is pivotally connected to the cylinder head via an adjuster and the other end is slidably inserted into the base end of the swing arm, and the plunger is locked to the swing arm when the valve is operated. With a simple configuration that includes a locking mechanism, it is possible to improve combustion and torque in the low engine speed range, and improve output in the high engine speed range. Since it is located near the center of swing of the swing arm, the weight of the valve system can be reduced. In addition, a zero lash adjuster is installed on the cylinder head, which further reduces the weight of the valve system and allows the swing arm to follow the cam up to the engine's high speed range, preventing problems such as valve jumping and bouncing. can be prevented. Furthermore,
There is an advantage that switching between valve operation and valve stop can be performed easily and reliably.

[Brief explanation of drawings]

The figures show a valve control device for an engine valve train system as an embodiment of the present invention.
The figure is a schematic configuration diagram showing a partially cutaway plan view, Figure 3 is a schematic diagram showing the valve when it is in operation, and Figure 4 is a schematic diagram showing the valve when it is stopped. be. 1...Secondary intake valve, 1a...Valve stem portion, 2...
...Cam, 3...Swing arm, 4...Cylinder, 4a...Slot hole, 5...Plunger, 6...Spring, 7...Cylinder head, 8...Zero lock adjuster, 9...Lock plate , 9a
...Narrow gap part, 9b...Wide gap part, 10...Cylinder, 11...Piston, 12...Spring receiver, 1
3... Return spring, 14... Actuator, 15... Connecting portion, 16... Connecting member, 17
...Hook-shaped part, 18...Timing lever, 19...
...Protrusion rod, 20...Oil chamber, 21...Guide, 22,
23... Spring receiver, 24, 25... Valve spring, E... Locking mechanism, M... Valve operation stop mechanism.

Claims (1)

[Claims] 1 In an engine valve system, in order to transmit the valve driving force from the cam installed above the valve stem,
A swing arm is provided, the middle portion of which is in contact with the lower surface of the cam, and the tip end of which is in contact with the upper surface of the stem portion of the valve, and one end of which is provided in the cylinder head to control the operation of the valve. A plunger is pivotally connected to the cylinder head via a latch adjuster, and the other end is slidably inserted into the base end of the swing arm, and the plunger engages the swing arm when the valve is actuated. A valve control device for an engine valve system, characterized in that a locking mechanism for stopping the engine is provided.