JP2001303917A - Valve system for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve system for an internal combustion engine at a low manufacturing cost. SOLUTION: A working fluid passage 33 in the axial direction, a first branched passage 34 and a second branched passage 35 which are branched from the working fluid passage 33 are formed in a rocker shaft 2. A first rocker arm 7 to open/close an engine valve 11 by a first cam 3 is provided on the rocker shaft 2. A second rocker arm 15 rocked by a third cam 5 and a third rocker arm 16 rocked by a third cam 5 are provided on the first rocker arm 7. A first operating means 24 to connect the first rocker arm 7 to the second rocker arm 15 and a second operating means 25 to connect the first rocker arm 7 to the third rocker arm 16 by operating a connection member 23 are provided. An actuator 38 to communicate the first branched passage 34 with the first operating means 24 and communicate the second branched passage 35 with the second operating means 25 by operating the rocker shaft 2 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve operating device for opening and closing an engine valve such as an intake valve and an exhaust valve of an internal combustion engine, and more particularly, to a three-stage lift amount of the engine valve according to the operating state of the internal combustion engine. To a variable valve actuation device.

[0002]

2. Description of the Related Art As a valve actuating device of this type, there is known, for example, a device described in Japanese Patent Application Laid-Open No. Hei 10-317928.

A valve actuating device described in the above publication is swingably supported by a rocker shaft, swings in response to rotation of a first cam to open and close an engine valve, and a first rocker arm. A second rocker arm that is swingably supported by the second cam and that opens and closes the engine valve by swinging in response to the rotation of the second cam; And a third rocker arm that swings to open and close the engine valve. In addition, there is provided a connecting member for integrally connecting the first rocker arm, the second rocker arm and the third rocker arm, and the first rocker arm and the second rocker arm are operated by operating the connecting member. There are first operating means for connecting and second operating means for operating the connecting member to connect the first rocker arm and the third rocker arm.

[0004] The first operating means and the second operating means are operated by hydraulic oil guided through oil passages formed correspondingly, and the oil passages extend in the axial direction of the rocker shaft. It is formed. That is, two oil passages are formed in the rocker shaft in the axial direction. An oil passage of a hydraulic oil supply device is connected to each of the two oil passages formed on the rocker shaft, and an electromagnetic passage for controlling suction and discharge of pressure oil is provided in the oil passage of the hydraulic oil supply device. A valve is provided. That is, two solenoid valves are provided in the middle of the oil passage of the hydraulic oil supply device.

[0005]

For this reason, in the conventional example, since two oil passages are formed in the axial direction of the rocker shaft, the number of processing steps is increased and the production cost may be increased. is there. In addition, since the solenoid valves are respectively provided in the oil passages of the hydraulic oil supply device, there are two oil passages and two solenoid valves, which may increase the manufacturing cost.

[0006] The present invention has been devised in view of the above-mentioned conventional circumstances, and has as its object to provide a valve operating device for an internal combustion engine which is inexpensive to manufacture.

[0007]

SUMMARY OF THE INVENTION Accordingly, the invention according to claim 1 is a valve operating device for an internal combustion engine capable of changing a lift amount of an engine valve according to an operation state of the internal combustion engine. A camshaft provided with a first cam, a second cam, and a third cam; a first branch passage, a second branch passage, and a second branch passage that are disposed in parallel to the camshaft and that branch from the hydraulic oil passage in the axial direction and the hydraulic oil passage, respectively. A rocker shaft having a branch passage formed therein, a first rocker arm swingably supported by the rocker shaft and swinging in response to rotation of the first cam to open and close an engine valve;
A second rocker arm swingably supported by the rocker arm and swinging in response to rotation of the second cam;
A third rocker arm swingably supported by the rocker arm and swinging in accordance with the rotation of the third cam;
A connecting member for integrally rockably connecting the rocker arm to the second rocker arm and the third rocker arm, and a first operation for operating the connecting member to connect the first rocker arm and the second rocker arm. Means, second operating means for operating the connecting member to connect the first rocker arm and the third rocker arm, and operating the rocker shaft to allow the first branch passage to communicate with the first operating means; An actuator for communicating the second branch passage with the second operation means and a hydraulic oil supply means for supplying hydraulic oil to a hydraulic oil passage formed in the rocker shaft are provided.

According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the actuator is such that a pin provided on the distal end side of the operating rod is engaged with a slot of a projection provided on the rocker shaft, The rocker shaft is rotated by the axial movement of the operating rod.

The lift amount of the first cam is smaller than the lift amounts of the second cam and the third cam.
The lift amount of the cam is formed larger than the lift amount of the first cam and smaller than the lift amount of the third cam, and the lift amount of the third cam is formed larger than the lift amounts of the first cam and the second cam. .

[0010] A control signal based on the operating state of the internal combustion engine is input to the actuator and the hydraulic oil supply means.

In this configuration, when the operation state of the internal combustion engine is the low-speed operation state, a control signal corresponding to the low-speed operation state is input to the actuator and the hydraulic oil supply means, and the actuator sets the reference state. While maintaining, the operating oil supply means does not operate and the operating oil is not supplied. Therefore, the hydraulic oil from the hydraulic oil supply means is not supplied to the hydraulic oil passage formed in the rocker shaft.

Thus, the first operating means and the second operating means
Since the operating means does not operate the connecting member, the second rocker arm and the third rocker arm do not become integral with the first rocker arm, and the first rocker arm, the second rocker arm, and the third rocker arm are not separated from each other. It is connected.

For this reason, the first rocker arm is provided with the first rocker arm.
The engine valve opens and closes according to the rotation of the cam. On the other hand, the second
The rocker arm swings according to the rotation of the second cam,
The rocker arm swings according to the rotation of the third cam,
The second rocker arm and the third rocker arm do not open or close the engine valve (low-speed operation state).

Next, when the operation state of the internal combustion engine is a medium speed operation state, a control signal corresponding to the medium speed operation state is input to the actuator and the hydraulic oil supply means. As a result, while the actuator maintains the reference state, the hydraulic oil supply means operates, and the hydraulic oil is supplied from the hydraulic oil supply means to the hydraulic oil passage formed in the rocker shaft.

The reference state of the actuator is such that the first branch passage of the rocker shaft communicates with the first operating means, but the second branch passage does not communicate with the second operating means. For this reason, the first branch passage communicates with the first operating means, so that hydraulic oil is supplied to the first operating means from the hydraulic oil passage formed in the rocker shaft, while the second operating path is connected to the second operating means.
No operating oil is supplied to the operating means.

Thus, the connecting member is operated by the first operating means, and the second rocker arm and the first rocker arm are integrally connected. On the other hand, since the second operating means does not operate the connecting member, the third rocker arm is not integrated with the first rocker arm, and the first rocker arm and the third rocker arm are not connected to each other. It is.

For this reason, the second rocker arm is
It swings according to the rotation of the cam, and opens and closes the engine valve via the first rocker arm. That is, the first rocker arm and the second rocker arm are integrated with each other, swing according to the rotation of the second cam, and open and close the engine valve. On the other hand, the third rocker arm swings according to the rotation of the third cam, but the third rocker arm does not open or close the engine valve (medium speed operation state).

Next, when the operation state of the internal combustion engine is a high-speed operation state, a control signal corresponding to the high-speed operation state is input to the actuator and the hydraulic oil supply means. As a result, the actuator operates the rocker shaft from the reference state, and the hydraulic oil supply means is operated. The hydraulic oil is supplied from the hydraulic oil supply means to the hydraulic oil passage formed in the rocker shaft.

The state where the rocker shaft is operated from the reference state by the actuator is a state in which the second branch passage communicates with the second operating means, and whether the first branch passage communicates with the first operating means is an arbitrary state. It is. For this reason, the second
When the branch passage communicates with the second operating means, hydraulic oil is supplied to the second operating means from a hydraulic oil passage formed in the rocker shaft, and when the first branch passage communicates with the first operating means, the operation is started. Oil is also supplied to the first operating means.

Thus, the connecting member is operated by the second operating means, and the third rocker arm and the first rocker arm are integrally connected. Further, when hydraulic oil is supplied to the first operating means, the second rocker arm and the first rocker arm are also connected, and the first rocker arm, the second rocker arm, and the third rocker arm are connected to each other. .

For this reason, the third rocker arm is connected to the third rocker arm.
It swings according to the rotation of the cam, and opens and closes the engine valve via the first rocker arm. That is, the first rocker arm and the third rocker arm are integrated with each other, swing in accordance with the rotation of the third cam, and open and close the engine valve (high-speed operation state).

In the present invention, the rocker shaft has one hydraulic oil passage in the axial direction, and the hydraulic oil passage has one hydraulic oil passage. Supply passage from the hydraulic oil supply means for supplying the oil supply is sufficient. For this reason, the man-hour for machining the hydraulic oil passage formed in the rocker shaft in the axial direction is reduced. Further, the number of solenoid valves provided in the supply passage from the hydraulic oil supply means can be reduced to one.

Therefore, a valve operating device for an internal combustion engine having a low manufacturing cost can be obtained.

Further, in the invention according to claim 2, in the actuator, a pin provided on the distal end side of the operating rod engages with a slot of a projection provided on the rocker shaft,
Since the rocker shaft is operated to rotate by the axial movement of the operating rod, the structure is simple and a reliable operation is achieved.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an explanatory view including a plan view of a valve operating device showing an embodiment of the present invention, FIG. 2 is a front view of the valve operating device shown in FIG. 1, and FIG. 3 is a sectional view taken along line AA of FIG. FIG. 4 is a cross-sectional view taken along line BB of FIG. 1 for explaining a low-speed operation state. FIG. 5 is a cross-sectional view taken along line C-C of FIG. 1 for explaining a low-speed operation state. FIG. 7 is a sectional view taken along line DD of FIG. 1, FIG. 7 is a sectional view taken along line BB of FIG.
Fig. 9 is a sectional view taken along the line CC of Fig. 1 for explaining a medium speed operation state, Fig. 9 is a sectional view taken along the line BB of Fig. 1 for explaining a high speed operation state.
FIG. 10 is a sectional view taken along the line CC of FIG. 1 for explaining the high-speed operation state, and FIG. 11 is a sectional view taken along the line DD of FIG. 1 for explaining the high-speed operation state.

The embodiment shown in FIGS. 1 to 11
2 shows a valve operating device in an intake valve corresponding to one of a plurality of cylinders of an internal combustion engine, and the exhaust valve has the same configuration.

In the figure, reference numeral 1 denotes a camshaft, which is rotatably driven by a crankshaft of an internal combustion engine (not shown). A rocker shaft 2 is provided in parallel with the camshaft 1, and the camshaft 1 and the rocker shaft 2 are rotatably supported in a cylinder head of an internal combustion engine (not shown).

A first cam 3, a second cam 4, and a third cam 5 having different lift amounts are formed on the outer periphery of the camshaft 1. The lift amount of the first cam 3 is smaller than the lift amounts of the second cam 4 and the third cam 5, and the lift amount of the second cam 4 is larger than the lift amount of the first cam 3 and the third cam 3 The lift amount of the third cam 5 is formed larger than the lift amount of the first cam 3 and the second cam 4. The first cam 3 is formed as a pair on both axial sides of the camshaft 1 with the second cam 4 and the third cam 5 interposed therebetween.

A first rocker arm 7 is swingably supported on the rocker shaft 2. The first rocker arm 7 has a U-shape as a whole, and the distal end side has a connecting portion 8.
And a cam follower 10 which is in contact with the first cam 3 of the camshaft 1. The arm 9 has an engine valve 11 at the tip end thereof. Operable. That is, the first rocker arm 7 swings in accordance with the rotation of the first cam 3, and the tip of the arm portion 9 operates the tip of the valve stem 13 urged by the valve spring 12, whereby the engine valve 1 is turned on.
1 is opened and closed. The engine valve 1
Reference numeral 1 denotes an intake valve in this embodiment.

Between the pair of arm portions 9 of the first rocker arm 7, there are provided a second rocker arm 15 and a third rocker arm 16 arranged in parallel with each other. 3 rocker arms 1
6 is swingably supported on the first rocker arm 7. Specifically, the second rocker arm 15 and the third rocker arm 16 are swingably supported by a pivot 17 attached to the first rocker arm 7.

The second rocker arm 15 has a cam follower 18 formed on the side facing the camshaft 1 and in contact with the second cam 4 of the camshaft 1, and is urged toward the camshaft 1 by a coil spring 19. Accordingly, it can swing according to the rotation of the second cam 4. The second rocker arm 15 is provided with a projection 15a which can be brought into contact with the first rocker arm 7.
The rotation of the rocker arm 15 is regulated at a predetermined position (see FIG. 4).

The third rocker arm 16 has a cam follower 20 formed on the side facing the camshaft 1 so as to be in contact with the third cam 5 of the camshaft 1, and is attached to the camshaft 1 side by a coil spring 21. And is swingable according to the rotation of the third cam. The third rocker arm 16 is provided with a projection 16a that can be brought into contact with the first rocker arm 7, and the rotation of the third rocker arm 16 by the spring force of the coil spring 21 is performed by the projection 16a at a predetermined position. (See FIG. 5).

The first rocker arm 7, the second rocker arm 15, and the third rocker arm 15 are provided between the first rocker arm 7 and the second rocker arm 15 and the third rocker arm 16.
A connecting member 23 for integrally swingably connecting the rocker arm 16 is provided, and a first operating means 24 and a second operating means 25 for operating the connecting member 23 are provided (FIGS. 4 and 5). 5).

The connecting member 23 is connected to the first rocker arm 7.
Is pivotally attached to a pivot 26 attached to the second rocker arm 15 or the third rocker arm 16 when one end is operated by the first operating means 24 or the second operating means 25. Engagement connects the first rocker arm 7 with the second rocker arm 15 and the third rocker arm 16. Specifically, the connecting member 23 is operated by the first operating means 24 to connect the first rocker arm 7 and the second rocker arm 15, and is operated by the second operating means 25 to connect the first rocker arm 7 to the first rocker arm 7. The three rocker arms 16 are connected.

The first operating means 24 comprises a first cylinder 27 formed on the first rocker arm 7 and a first piston 28 inserted into the first cylinder 27 as main elements. Connecting member 23 at the tip of piston 28
Is operated (see FIG. 4).
The first piston 28 is formed in a stepped shape, and the maximum stroke is limited by the stepped portion contacting the first cylinder 27.

The second operating means 25 includes a second cylinder 29 formed on the first rocker arm 7 and a second cylinder 29 formed on the second rocker arm 7.
The second piston 30 inserted into the cylinder 29 is configured as a main element, and one end of the connecting member 23 is operated at the tip of the second piston 30 (see FIG. 5).

The rocker shaft 2 has an axial
The hydraulic oil passage 33 is formed, and a first branch passage 34 and a second branch passage 35 in the radial direction that branch off from the hydraulic oil passage 33 are formed. The first branch passage 3
4 is formed so as to open at a position corresponding to the second rocker arm 15, and the second branch passage 35 is formed so as to open at a position corresponding to the third rocker arm 16. Branch passage 34 and second branch passage 35
Are open at positions shifted from each other in the circumferential direction. Also,
The open end of the first branch passage 34 and the open end of the second branch passage 35 are formed to be flat, respectively, so that oil chambers 36 and 37 are formed between the open ends of the first branch passage 34 and the inner periphery of the first rocker arm. Has become.

By rotating the rocker shaft 2, the first branch passage 34 is moved through the oil chamber 36 to the first operating means 24 (the first cylinder 27 of the first operating means 24).
The second branch passage 35 can communicate with (the second cylinder 29 of) the second operating means 25 via the oil chamber 37.

The rocker shaft 2 is provided with an actuator 38 for rotating the rocker shaft 2. The actuator 38 is a projection provided on the rocker shaft 2 with a pin 40 provided at the tip end of an operating rod 39. 41 is engaged with the slot 42 of the operating rod 3.
The rocker shaft 2 is rotated in accordance with the axial movement of the lock 9 (see FIGS. 1 and 6).

The operating oil is supplied from operating oil supply means 45 to the operating oil passage 33 of the rocker shaft 2. The hydraulic oil supply means 45 includes an oil pump 47 that sucks and discharges hydraulic oil in an oil pan 46.
And a supply passage 48 for guiding oil discharged from the oil pump 47.
And a solenoid valve 49 provided in the middle of the supply passage 48 for controlling the selective supply of hydraulic oil as a main element.
In this embodiment, a normally-closed three-port valve is employed as the solenoid valve 49.
One is connected to the drain passage 50.

A control signal from a control device 52 is guided to the actuator 38 and the solenoid valve 49 of the hydraulic oil supply means 45. The control device 52 supplies a signal indicating the operating state of the internal combustion engine, for example, A crankshaft speed signal is input.

In such a configuration, the control device 52
A signal indicating the operating state of the internal combustion engine is input to the controller 52, and a control signal corresponding to the operating state is output from the control device 52.
Is input to

First, when the operation state of the internal combustion engine is the low-speed operation state, a control signal corresponding to the low-speed operation state is input to the actuator 38 and the solenoid valve 49 of the hydraulic oil supply means 45, and the actuator 38 Reference condition (Fig. 6
), The hydraulic oil supply means 45 does not operate, and the electromagnetic valve 49 is kept closed in a state where hydraulic oil is not supplied. Therefore, the working oil from the working oil supply means 45 is not supplied to the working oil passage 33 formed in the rocker shaft 2.

Thus, the first cylinder 27 of the first operating means 24 and the second cylinder 2 of the second operating means 25
Since the operating oil is not supplied to 9, the first operating means 24 and the second operating means 25 do not operate the connecting member 23. For this reason, the second rocker arm 15 and the third rocker arm 16 do not become integral with the first rocker arm 7, and the first rocker arm 7, the second rocker arm 15 and the third rocker arm 16 are not mutually independent. It is in a connected state (see FIGS. 4 and 5).

As a result, the first rocker arm 7 opens and closes the engine valve 11 according to the rotation of the first cam 3. on the other hand,
The second rocker arm 15 swings according to the rotation of the second cam 4, and the third rocker arm 16 swings according to the rotation of the third cam 5. These second rocker arm 15 and third rocker The arm 16 does not open or close the engine valve 11 (low-speed operation state). The swing of the second rocker arm 15 is absorbed by the coil spring 19, and the swing of the third rocker arm 16 is absorbed by the coil spring 21.

Next, when the operation state of the internal combustion engine is a medium speed operation state, a control signal corresponding to the medium speed operation state is input to the actuator 38 and the solenoid valve 49 of the hydraulic oil supply means 45. Thereby, the actuator 3
Numeral 8 maintains the reference state (see FIG. 6), while the hydraulic oil supply means 45 operates to open the solenoid valve 49 (see FIG. 1).
Therefore, the hydraulic oil from the hydraulic oil supply means 45 is supplied to the hydraulic oil passage 33 formed in the rocker shaft 2.

The reference state of the actuator 38 is such that the first branch passage 34 of the rocker shaft 2 is
4, the second branch passage 35 is connected to the second operating means 25.
Is not in communication. For this reason, while the first branch passage 34 communicates with the first operating means 24, hydraulic oil is supplied from the hydraulic oil passage 33 formed in the rocker shaft 2 to the first cylinder 27 of the first operating means 24. The operating oil is not supplied to the second cylinder 29 of the second operating means 25.

Thus, the connecting member 23 is operated by the first operating means 24 and the second rocker arm 15 is operated.
And the first rocker arm 7 are integrally connected (FIG. 7).
reference). Specifically, the distal end of the first piston 28 of the first operating means 24 presses one end of the connecting member 23 and rotates the connecting member 23 counterclockwise in FIG. The other end of the member 23 is engaged with a predetermined position of the second rocker arm 15, and the second rocker arm 15 and the first rocker arm 7 are integrally connected.

On the other hand, the second operating means 25 is
Since the third rocker arm 16 is not operated,
Is not integrated with the first rocker arm 7, and the first rocker arm 7 and the third rocker arm 16 are not connected to each other (see FIG. 8).

Therefore, the second rocker arm 15 swings according to the rotation of the second cam 4, and opens and closes the engine valve 11 via the first rocker arm 7. That is, the first rocker arm 7 and the second rocker arm 15 are integrated with each other and swing in accordance with the rotation of the second cam 4, so that the engine valve 1
Open and close 1. On the other hand, the third rocker arm 16 swings in accordance with the rotation of the third cam 5, but the third rocker arm 16 does not open or close the engine valve 11 (medium speed operation state). The swing of the third rocker arm 16 is absorbed by the coil spring 21.

Next, when the operation state of the internal combustion engine is a high-speed operation state, a control signal corresponding to the high-speed operation state is input to the actuator 38 and the solenoid valve 49 of the hydraulic oil supply means 45. Thereby, the actuator 3
8 operates the rocker shaft 2 from the reference state (FIG. 1)
1), the hydraulic oil supply means 45 is operated to open the solenoid valve 49 (see FIG. 1). Therefore, the hydraulic oil is supplied from the hydraulic oil supply means 45 to the hydraulic oil passage 33 formed in the rocker shaft 2. Supplied.

When the actuator 38 operates the rocker shaft 2 from the reference state, the second branch passage 35 communicates with the second operating means 25, and the first branch passage 34 communicates with the first operating means 24. Whether or not to do so is an arbitrary state, and in this embodiment, the state is such that the first branch passage 34 communicates with the first operating means 24. For this reason, when the second branch passage 35 communicates with the second operating means 25, the operating oil is supplied to the second operating means 25 from the hydraulic oil passage 33 formed in the rocker shaft 2, and the first branch passage is provided. The hydraulic fluid is also supplied to the first operating means 24 by the communication of the first operating means 24 with the first operating means 24.

Thus, the connecting member 23 is operated by the second operating means 25 and the third rocker arm 16 is operated.
And the first rocker arm 7 are integrally connected (FIG. 1
0). Specifically, the tip of the second piston 30 of the second operating means 25 presses one end of the connecting member 23,
By rotating the connecting member 23 in the counterclockwise direction in FIG. 10, the other end of the connecting member 23 is engaged with a predetermined position of the third rocker arm 16, and the third rocker arm 16 and the first rocker arm 16 are engaged. 7 are integrally connected.

Further, hydraulic oil is also supplied to the first operating means 24, and the second rocker arm 15 and the first rocker arm 7 are also connected. The first rocker arm 7, the second rocker arm 15, and the third rocker arm are also provided. 16 are connected to each other. In this case, the maximum stroke of the first piston 28 of the first operating means 24 is limited by being formed in a stepped shape, so that the connecting member 23 is operated in a state similar to the medium speed operation state. (See FIG. 9).

For this reason, the third rocker arm 16 swings in accordance with the rotation of the third cam 5, and opens and closes the engine valve 11 via the first rocker arm 7. That is, the first rocker arm 7 and the third rocker arm 16 are integrated with each other and swing in accordance with the rotation of the third cam 5, so that the engine valve 1
1 is opened and closed (high-speed operation state).

Here, in the present invention, the hydraulic oil passage 33 formed in the rocker shaft 2 is one in the axial direction, and the hydraulic oil passage 33 is one. A single supply passage 48 from the hydraulic oil supply means for supplying the hydraulic oil to 33 is sufficient. For this reason, the man-hour for processing the hydraulic oil passage 33 formed in the rocker shaft 2 in the axial direction is reduced. Further, the number of solenoid valves 49 provided in the supply passage 48 from the hydraulic oil supply means 45 can be reduced to one.

Therefore, a valve operating device for an internal combustion engine having a low manufacturing cost can be obtained.

In the actuator 38, a pin 40 provided on the distal end side of the operating rod 39 is engaged with a slot 42 of a projection 41 provided on the rocker shaft 2, and the rocker shaft 2 is moved by moving the operating rod 39 in the axial direction. Since the rotation operation is performed, the structure is simple and a reliable operation is achieved.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment, and can be changed without departing from the spirit of the invention.

[0061]

As described above in detail, according to the present invention, a valve operating device for an internal combustion engine which is inexpensive to manufacture can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view including a plan view of a valve operating device showing an embodiment of the present invention.

FIG. 2 is a front view of the valve operating device shown in FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a sectional view taken along the line BB of FIG. 1, illustrating a low-speed operation state.

FIG. 5 is a sectional view taken along line CC of FIG. 1 for explaining a low-speed operation state.

FIG. 6 is a sectional view taken along line DD of FIG. 1 for explaining a low-speed operation state.

FIG. 7 is a sectional view taken along the line BB of FIG. 1 for explaining a medium speed operation state.

FIG. 8 is a sectional view taken along the line CC of FIG. 1 for explaining a medium speed operation state.

FIG. 9 is a sectional view taken along the line BB of FIG. 1 for explaining a high-speed operation state.

FIG. 10 is a sectional view taken along line CC of FIG. 1 for explaining a high-speed operation state.

FIG. 11 is a sectional view taken along line DD in FIG. 1 for explaining a high-speed operation state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Camshaft 2 Rocker shaft 3 1st cam 4 2nd cam 5 3rd cam 7 1st rocker arm 15 2nd rocker arm 16 3rd rocker arm 23 Connecting member 24 1st operating means 25 2nd operating means 33 Hydraulic oil passage 34 first branch passage 35 second branch passage 38 actuator 45 hydraulic oil supply passage

Claims (2)

[Claims] 1. A valve operating device for an internal combustion engine capable of changing a lift amount of an engine valve according to an operation state of the internal combustion engine, wherein the first, second and third cams have different lift amounts. A shaft, a rocker shaft arranged in parallel with the camshaft and having a first branch passage and a second branch passage formed in the hydraulic oil passage in the axial direction and branching from the hydraulic oil passage, respectively; A first rocker arm that is swingably supported and swings in response to the rotation of the first cam to open and close the engine valve; and a second rocker arm that is swingably supported by the first rocker arm.
A second rocker arm that swings in accordance with the rotation of the cam; and a third rocker arm that is swingably supported by the first rocker arm.
A third rocker arm that swings according to the rotation of the cam, a connecting member that integrally swingably connects the first rocker arm, the second rocker arm, and the third rocker arm; and operating the connecting member. And the first rocker arm and the second
A first operating means for connecting the rocker arm, a second operating means for operating the connecting member to connect the first rocker arm and the third rocker arm, and a first branch passage operating the rocker shaft; And a hydraulic oil supply means for supplying hydraulic oil to a hydraulic oil passage formed in the rocker shaft, and an actuator for communicating the hydraulic fluid to the first operating means and the second branch passage to the second operating means. A valve operating device for an internal combustion engine, characterized in that: 2. The actuator according to claim 1, wherein a pin provided on a distal end side of the operation rod is engaged with a slot of a projection provided on the rocker shaft, and the rocker shaft is rotated by an axial movement of the operation rod. The valve operating device for an internal combustion engine according to claim 1, characterized in that: