JP2002188418A - Variable load valve of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable load valve of internal combustion engine, in the case of changing the load condition of an internal combustion engine, reducing the drive power used for movement between both cams the durability, having a simple structure, and responding quickly, and moreover, also improving. SOLUTION: A roller follower 21 has a flange part 22a extended in the direction of a outside diameter in one side; and an inner ring 22 movably supported by a roller shaft 20 at in the shaft orientation has a flange part extended in the direction of the inside diameter, and an outer ring 23 switches to a low cam 8 and a high cam 9, and abuts against contact: a roller 24 is arranged between this inner ring 22 and outer ring 23, the a flange part 22a and a flange part 23a arranged at the other side; possing a toroidal support material 25 which touches and contacts with an end-face 24b of a roller 24 and an end-face 22b of inside ring 22; a toroidal support material 25 touches to a return spring 60; a piston touches to a flange part of an internal ring 22, and outer ring switches and connects to a low cam 8 and a high cam 9 which are pushed by a piston 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve operating apparatus for an internal combustion engine that changes the lift amount of intake and exhaust valves of the internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, this type of device includes a rocker arm rotatably supported by a rocker shaft and a low cam (small projecting amount to the rocker arm) rotatably supported by a cam shaft and engaged with one end of the rocker arm. ) And a high cam (a large protruding amount to the rocker arm). The rocker arm is movable in the axial direction of the rocker shaft. When the load state of the internal combustion engine changes, the entire rocker arm is moved between the two cams. By moving in the axial direction with
The rocker arm is engaged from the low cam to the high cam or from the high cam to the low cam.

[0003]

However, in such a device, when the load condition of the internal combustion engine changes, the entire heavy and large rocker arm is moved in the axial direction. It becomes excessive, and a response delay occurs.

Further, a roller follower is provided which, when the load condition of the internal combustion engine changes, moves the roller follower to engage from the low cam to the high cam or to engage from the high cam to the low cam. However, as a mechanism for moving the roller follower, the structure is complicated when the roller follower is supported by a holder such as a sheet metal and the holder is moved by the moving mechanism.

[0005] If a return spring is provided at one end of the roller follower and the other end is pushed, the structure is simplified. However, the contact of the return spring and the pushing mechanism allows smooth rotation of the roller of the roller follower. In addition, there is a problem in durability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and reduces the driving force used to move between two cams with a simple structure when the load condition of the internal combustion engine changes, and provides a quick response. It is an object of the present invention to provide a variable valve actuation device for an internal combustion engine which can be improved and has improved durability.

[0007]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention has the following constitution.

According to the first aspect of the present invention, there is provided an intake / exhaust valve for opening / closing an intake / exhaust passage of an internal combustion engine, a rocker arm swingably supported on a rocker shaft and pushing the intake / exhaust valve, and the rocker arm. And a high cam that swings the rocker arm with the rocker shaft as a fulcrum and the amount of protrusion of the rocker arm is larger than the low cam. A roller shaft fixed to the rocker arm, and a roller follower disposed around the roller shaft so as to be slidable in the axial direction of the roller shaft.
An inner ring which has a flange portion extending in the outer diameter direction on one side and is supported movably in the axial direction by the roller shaft, and a flange portion which extends in the inner diameter direction at a position inside the flange portion of the inner ring, An outer ring that switches and contacts the low cam and the high cam,
A roller disposed between the inner ring and the outer ring; and an annular support member disposed on a side opposite to the flange of the inner ring and the flange of the outer ring and in contact with an end surface of the inner ring and an end surface of the roller. Then, a return spring is brought into contact with the annular support member, a piston is brought into contact with the flange of the inner ring, and the outer ring is switched between the low cam and the high cam by pushing the piston. A variable valve operating device for an internal combustion engine, characterized in that: ].

According to the first aspect of the present invention, the roller follower is disposed around the roller shaft so as to be slidable in the axial direction of the roller shaft, and the return spring abuts on the annular support member of the roller follower. The piston is brought into contact with the flange of the inner ring, the return spring and the piston are not in contact with the outer ring, and the outer ring is switched between the low cam and the high cam. The driving force used for the movement of the roller can be reduced with a simple structure, the response can be made quickly, and the durability of the roller follower can be improved.

Further, the roller follower can be easily assembled by disposing a roller between the inner ring and the outer ring, and bringing the annular support member into contact with the end surface of the inner ring and the end surface of the roller.

According to a second aspect of the present invention, a cylinder is formed around the roller shaft of the rocker arm,
2. The cylinder according to claim 1, wherein the piston is movably arranged on the axis of the roller shaft, and oil is supplied to the cylinder from an oil passage communicating with the cylinder to make the piston movable. A variable valve train for an internal combustion engine according to claim 1. ].

According to the second aspect of the present invention, the piston is disposed on the cylinder formed around the roller shaft of the rocker arm so as to be movable on the axis of the roller shaft, and the piston is supplied by supplying oil to the cylinder. Since it is movable, it is easy to secure a space for arranging the piston, and it is possible to apply a pressing force of the piston to the entire inner ring of the roller follower with a compact structure, so that the movement of the roller follower can be more smoothly and stabilized. .

According to a third aspect of the present invention, a cylinder is formed near the roller shaft of the rocker arm in the axial direction of the roller shaft, the piston is disposed in the cylinder, and oil is supplied from an oil passage communicating with the cylinder. 2. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the piston is movable by supplying the piston to the cylinder. ].

According to the third aspect of the present invention, the piston is arranged in the cylinder formed in the roller shaft axial direction near the roller shaft of the rocker arm, and oil is supplied to the cylinder so that the piston can be moved. The degree of freedom in the arrangement space of the piston is improved, and the pressing force of the piston can be applied to the inner ring of the roller follower with a compact structure.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a variable valve operating device for an internal combustion engine according to the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 4 show a first embodiment.
1 is a cross-sectional view of the variable valve operating device of the engine, FIG. 2 is a cross-sectional view of the variable valve operating device, FIG. 3 is a plan view of the variable valve operating device showing a state where the low cam is engaged, and FIG. FIG. 4 is a plan view of the variable valve operating device showing a state in which the variable valve operating device is operated.

In the cylinder of the internal combustion engine, one combustion recess 1a is provided for each cylinder at the cylinder block side mating surface 1g of the cylinder head 1, and each combustion recess 1a has one combustion recess per cylinder.
Alternatively, a plurality of intake valve openings 1b and exhaust valve openings (not shown) are open.

The intake valve opening 1b is led out to the outer wall 1d of the cylinder head 1 by an intake passage 1c.
An air intake system (not shown) is connected to the external connection port 1e of c.
Here, c is the cylinder bore axis.

The intake valve opening 1b can be opened by a valve plate 2a of the intake valve 2. The valve shaft 2b of the intake valve 2 extends obliquely outward with respect to the cylinder bore axis c, and its upper portion projects into the cam chamber a, and is axially driven by a valve guide 3 which is cylindrical and press-fitted into the ceiling wall of the intake passage 1c. It is slidably supported in the direction.

The valve spring 5 having a double coil spring structure is in a compressed state between the retainer 4 detachably mounted on the upper end of the valve shaft 2b and the spring seat 1f formed on the bottom wall of the cam chamber of the cylinder head 1. The intake valve 2 is biased in a direction to close the intake valve opening 1b. A pad 4a made of a wear-resistant alloy is provided on the head of the valve shaft 2b, and is pressed by a pressing portion 6a of the rocker arm 6.

Head cover side mating surface 1 of cylinder head 1
h, the intake camshaft 7 is arranged parallel to the crankshaft. The intake camshaft 7 is attached to a cylindrical base shaft portion 7a.
A low cam 8 (low-speed cam) and a high cam 9 (high-speed cam) are integrally formed for each cylinder, and an inter-cylinder portion is supported by a cam bearing portion 1i formed on the cylinder head 1 and a cam cap (not shown). .

The rocker arm 6 is supported by a rocker shaft 10, and the rocker arm 10 can swing about the rocker shaft 10. A camshaft 7 is disposed above the rocker arm 6.
Are driven by an output shaft (not shown) of the internal combustion engine.

The low cam 8 of the camshaft 7 swings the rocker arm 6 around the rocker shaft 10, the high cam 9 swings the rocker arm 6 around the rocker shaft 10, and the high cam 9 projects out to the rocker arm 6. Larger than low cam 8.

The variable valve operating device of the internal combustion engine includes a roller shaft 20 fixed to the rocker arm 6 so as to be positioned in parallel with the camshaft 7,
And a roller follower 21 slidably disposed around the roller shaft 20 in the axial direction. The roller follower 21 slides in the axial direction of the roller shaft 20 at the position of the opening 6 b formed in the rocker arm 6.

The roller follower 21 has an inner race 22 and
It comprises an outer ring 23, a roller 24, and an annular support member 25. The inner ring 22 has a flange portion 22a extending to one side in an outer radial direction.
And is supported by the roller shaft 20 so as to be movable in the axial direction. The outer race 23 has a flange 23 a extending in the inner diameter direction at a position inside the flange 22 a of the inner race 22.
And the high cam 9 to make contact. A plurality of rollers 24 are disposed between the outer ring 23 and the inner ring 22 and have an end 24a.
Abuts against and is supported by the flange 23 a of the outer race 23.

The annular support member 25 is made of, for example, a washer, and is disposed on the side opposite to the flange 22a of the inner race 22 and the flange 23a of the outer race 23.
4 is in contact with the end face 24b.

One end 60a of the return spring 60 abuts against the annular support member 25, and the return spring 6
0 is a concave portion 6 formed in the rocker arm 6.
c, the return spring 60 always urges the outer ring 23 of the roller follower 21 to engage with the low cam 8.

A piston 26 is brought into contact with the other flange portion 22a of the inner ring 22, and the inner ring 22
Moves against the return spring 60, and in this embodiment, the outer ring 23 engages with the high cam 9 when the internal combustion engine is under a high load.

Further, in this embodiment, a cylinder 27 is formed around the roller shaft 20 of the rocker arm 6, and a piston 26 is arranged on the cylinder 27 so as to be movable on the axis of the roller shaft 20.

An oil passage 28 is formed in the rocker shaft 10 in the axial direction, and an oil passage 29 is formed in an outward direction in communication with the oil passage 28. The rocker arm 6 has an oil passage 30 that connects the oil passage 29 and the cylinder 27.

The oil passages 28, 2 of the rocker shaft 10
Oil is supplied to the cylinder 27 from the cylinder 9 through the oil passage 30 of the rocker arm 6, and the piston 26 is moved by the pressure of the oil.

As described above, the roller follower 21 is disposed around the roller shaft 20 so as to be slidable in the axial direction of the roller shaft 20, and the flange 2 of the inner ring 22 of the roller follower 21 is provided.
2b, the return spring 60 abuts, the piston 26 abuts on the side of the flange 22a of the inner race 22, the return spring 60 and the piston 26 do not contact the outer race 23, and the low cam 8 And engages the high cam 9 when the internal combustion engine is under a high load.
When the load condition of the internal combustion engine changes, the driving force used for movement between the two cams can be reduced with a simple structure, and a quick response can be achieved, and the durability of the roller follower 21 is also improved.

The roller shaft 2 of the rocker arm 6
The piston 26 is movably arranged on the axis of the roller shaft 20 in the cylinder 27 formed around the cylinder 0, and oil is supplied to the cylinder 27 so that the piston 26 can be moved. The pressing force of the piston 26 can be applied to the entire inner ring 22 of the roller follower 21 with a simple and compact structure, and the movement of the roller follower 21 can be more smoothly and stabilized.

The roller follower 21 has a roller 24 disposed between the inner race 22 and the outer race 23, and has an annular support member 25 on the end face 22 b of the inner race 22 and the end face 24 b of the roller 24.
Can be abutted, and assembly is easy.

FIGS. 5 to 7 show a second embodiment.
FIG. 5 is a cross-sectional view of the variable valve operating device, FIG. 6 is a plan view of the variable valve operating device showing a state in which it engages with the low cam, and FIG. 7 is a plan view of the variable valve operating device showing a state in which it engages with the high cam. .

The second embodiment is configured in the same manner as the first embodiment. However, in the second embodiment,
A cylinder 40 is formed near the roller shaft of the rocker arm 6 in the axial direction of the roller shaft, and a piston 41 is arranged in the cylinder 40.

The oil passages 28, 2 of the rocker shaft 10
9 supplies oil to the cylinder 27 via the oil passage 30 of the rocker arm 6, and moves the piston 41 by the pressure of the oil.

As described above, the cylinder 40 formed near the roller shaft of the rocker arm 6 in the axial direction of the roller shaft.
The piston 41 is disposed on the cylinder 41 and oil is supplied to the cylinder 40 to make the piston 41 movable.
The degree of freedom of the arrangement space is improved, and the pressing force of the piston 41 can be applied to the inner ring 22 of the roller follower 21 with a compact structure.

[0039]

As described above, according to the first aspect of the present invention, the roller follower is disposed around the roller shaft so as to be slidable in the axial direction of the roller shaft, and the return spring is attached to the annular support member of the roller follower. When the load state of the internal combustion engine changes, the outer ring is switched between the low cam and the high cam without the return spring and the piston being in contact with the outer ring. The driving force used for movement between the two cams can be reduced with a simple structure and can respond quickly.
In addition, the durability of the roller follower is improved.

The roller follower can be easily assembled by disposing a roller between the inner ring and the outer ring, and bringing the annular support member into contact with the end surface of the inner ring and the end surface of the roller.

According to the second aspect of the present invention, the piston is arranged on the cylinder formed around the roller shaft of the rocker arm so as to be movable on the axis of the roller shaft, and oil is supplied to the cylinder to make the piston movable. Since the,
It is easy to secure a space for arranging the piston, and it is possible to apply a pressing force of the piston to the entire inner ring of the roller follower with a compact structure, and to more smoothly and stably move the roller follower.

According to the third aspect of the present invention, the piston is disposed in the cylinder formed in the roller shaft axial direction near the roller shaft of the rocker arm, and oil is supplied to the cylinder so that the piston can be moved. The degree of freedom in space is improved, and the pressing force of the piston can be applied to the inner ring of the roller follower with a compact structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a variable valve operating device of an engine.

FIG. 2 is a sectional view of a variable valve operating device.

FIG. 3 is a plan view of the variable valve operating device showing a state in which it is engaged with a low cam.

FIG. 4 is a plan view of the variable valve apparatus showing a state in which it is engaged with a high cam.

FIG. 5 is a sectional view of a variable valve operating device.

FIG. 6 is a plan view of the variable valve apparatus showing a state in which it is engaged with a low cam.

FIG. 7 is a plan view of the variable valve apparatus showing a state in which it is engaged with a high cam.

[Explanation of symbols]

 6 Rocker arm 8 Low cam 9 High cam 10 Rocker shaft 20 Rocker shaft 21 Roller follower 22 Inner ring 23 Outer ring 24 Roller 25 Annular support member 26 Piston 60 Return spring

Claims (3)

[Claims] An intake / exhaust valve for opening and closing an intake / exhaust passage of an internal combustion engine, a rocker arm slidably supported by a rocker shaft and pushing the intake / exhaust valve, and a rocker arm swinging about the rocker shaft as a fulcrum. A variable cam valve, comprising: a low cam to be moved; and a high cam, which swings the rocker arm around the rocker shaft as a fulcrum, and a protruding amount of the rocker arm is larger than the low cam. A shaft, and a roller follower disposed around the roller shaft so as to be slidable in the axial direction of the roller shaft.The roller follower has a flange portion extending in an outer radial direction on one side, An inner ring supported movably in the axial direction by the roller shaft, and a flange portion extending in the inner diameter direction at a position inside the flange portion of the inner ring. An outer ring that switches and contacts the low cam and the high cam; a roller disposed between the inner ring and the outer ring; a roller disposed on a side opposite to a flange of the inner ring and a flange of the outer ring; An end surface and an annular support member that abuts against an end surface of the roller, a return spring abuts the annular support member, a piston abuts a flange portion of the inner ring, and the outer ring is pushed by the piston to move the outer ring. A variable valve train for an internal combustion engine, wherein the low cam and the high cam are selectively engaged. 2. A cylinder is formed around the roller shaft of the rocker arm, and the piston is disposed in the cylinder so as to be movable on the axis of the roller shaft, and the cylinder receives oil from an oil passage communicating with the cylinder. The variable valve train for an internal combustion engine according to claim 1, wherein the piston is made movable by supplying the piston to the internal combustion engine. 3. A cylinder is formed near the roller shaft of the rocker arm in the axial direction of a roller shaft, the piston is disposed in the cylinder, and oil is supplied to the cylinder from an oil passage communicating with the cylinder to thereby form the piston. 2. The variable valve train of an internal combustion engine according to claim 1, wherein the variable valve train is movable.