JPS6030406A - Device for forcibly opening and closing valve in internal-combustion engine - Google Patents

Abstract

PURPOSE:To reduce the frictional loss between each of valve opening and closing rocker arms and a shaft, by providing a cylindrical collar or boss to either one of the valve opening and closing rocker arms so that the other one of the rocker arms is supported through the collar or boss. CONSTITUTION:Valve opening and closing cams 30, 31 are provided adjacent to a cam shaft 29. A cylindrical boss or collar 46 is provided integrally with or slidably to either one of a first rocker arm 33 adjacent to the cam 30 and a second rocker arm 34 adjacent to the cam 31, and the other one of the rocker arms is supported to a rocker shaft 32 through this boss or collar 46. Thereby, urging force with respect to the rocker shaft under lever action by both rocker arms may be prevented from acting directly to the slide section between them and the rocker arm shaft, thereby the frictional loss therebetween may be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, an opening side cam and a closing side cam that are adjacent to each other in the axial direction are integrated into a rotationally driven camshaft, and a tenth lug arm that is in sliding contact with the opening side cam, and a closing side cam that is in sliding contact with the opening side cam, A 20th lug arm that slides on the side cam and is interlocked with the 10th lug arm is swingably supported on a rocker arm shaft parallel to the cam shaft, and one of the first and 20th lug arms is connected to the intake pulp or the exhaust pulp. The present invention relates to a pulp forced opening/closing device for an internal combustion engine to which the engine is connected.

Conventionally, in the forced pulp opening/closing device, as shown in FIG.
The lug arm 33 and the 20th lug arm 34 are directly pivoted adjacent to each other, and the adjustment screw 35 screwed onto the 20th lug arm 34 is brought into contact with the 10th lug arm 33, so that the intake pulp or the exhaust pulp is supplied to the 10th lug arm 33. Concatenated. In such a pulp forced opening/closing device, the swinging motion of the 20th claw arm 34 in response to the rotational movement of the closing side cam 310 is transmitted to the 10th claw arm 33 via the adjustment screw 35, whereby the intake pulp or the exhaust pulp is Driven to open and close.

By the way, in the above-described force transmission, a large force acts in the direction of pressing each rocker arm 33, 34 against the rocker arm shaft 32 due to the lever action, resulting in friction loss. That is, in FIG. 9, the rotational force acting on the 20th claw arm 34 by the closing side cam 31 is
c, the inertial force acting on the 10th lever arm 33 by the intake or exhaust pulp system is FV, the length from the rocker arm shaft 32 to the adjustment screw 35 is α, and the force pressed against the 10th lever arm shaft 32 is '-F c So, the first
The force with which the zero tension arm 33 is pressed against the rocker arm shaft 32 is -Fv. Each rocker arm 33, 34 (7) is pressed against the rocker arm shaft 32 by a force (-!l-
pc) and (-Fv), friction loss occurs between the rocker arm shaft 32 and each rocker arm 33, 34.

The present invention has been made in view of such circumstances, and includes a cylindrical inclusion that is integrated with or slidably inserted between one rocker arm and the rocker arm shaft of the other rocker arm. An object of the present invention is to provide a pulp forced opening/closing device for an internal combustion engine in which the pressing of the rocker arm by lever action prevents force from reaching the sliding part with the rocker arm shaft, and reduces friction loss.

Hereinafter, an embodiment in which the present invention is applied to a motorcycle will be described with reference to the drawings. First, in FIG. 1, a 4-cylinder internal combustion engine main body E is mounted on a body frame F of a motorcycle. An exhaust pipe 1 that communicates with the exhaust port of each cylinder and extends rearward is connected to the front part of the internal combustion engine body E, and four carburetors 2 are connected to the intake port of each cylinder individually at the rear part of the internal combustion engine main body E. , and each vaporizer 2 is commonly connected to an air cleaner 3. The internal combustion engine of such a motorcycle is provided with a pulp forced opening/closing device according to the present invention.

2 and 3, pistons 5 are fitted into the four cylinders 4 of the internal combustion engine main body E so as to be able to reciprocate, and a pair of intake ports 7 are individually connected to the cylinder head 6 of each cylinder 4. A pair of intake ports 8 adjacent to each other and communicating with a pair of exhaust ports 9 and a pair of exhaust ports 10 adjacent to each other and connected to a pair of exhaust ports 9 are formed to open toward a combustion chamber 11. Spark plug 1 is placed in the upper center of chamber 11.
2 is installed.

Each intake port 8 is provided with an intake valve 13, and each exhaust port 10 is provided with an exhaust valve 14. Each intake valve 13 and exhaust valve 14 is movably inserted into a guide tube 15° 16 provided vertically through the cylinder head 6, and retainers 17, 1 are screwed onto the upper end thereof.
8. Also, each intake valve 13 and exhaust valve 14 are provided between the flanges 19 and 20 provided in the middle of the guide cylinder 15 and 16.
Valve springs 21 and 22 are interposed to bias the valves in the valve-closing direction.

At the top of the cylinder head 6, a forced valve opening/closing device 23 for the intake valve 13 and a forced pulp opening/closing device 24 for the exhaust valve 14 are provided.
24 is a pair of working chambers 27 and 28 formed by a cover 25 and 26 that oil-tightly covers the upper end of the cylinder head 6.
contained within.

One pulp forced opening/closing device 23 has a pair of intake valves 1
a camshaft 29 that extends substantially horizontally along the arrangement direction of the cylinder head 6, is supported by the cylinder head 6, and is driven to rotate at a rotation ratio of % in synchronization with the rotation of the engine; and an open side that is integrated with the camshaft 29. The cam 30 and the cam shaft 29 adjacent to the opening side cam 30
a closing-side cam 31 that is integrated into the cylinder head; a rocker arm shaft 32 that has an axis parallel to the cam shaft 29 and is fixed to the cylinder head 6; and a pair of intake valves 13 that are swingable around the rocker arm shaft 32. a tenth lug arm 33 connected to the opening side cam 30 and slidingly in contact with the opening side cam 30; a twentieth lug arm 34 that is swingable around the rocker arm shaft 32 and slidingly in contact with the closing side cam 31; 1 Adjustment screw 35 that comes into contact with rocker arm 33
It consists of

The rocker arm shaft 32 is located below the camshaft 29 and is connected to the intake valve 13 with respect to a vertical line passing through the axis of the camshaft 29.
0 is placed on the opposite side. The tenth lever arm 33 extends obliquely upward toward the intake valve 13 from a pivot portion 33α that is pivotally supported on the rocker arm shaft 32, and has a pair of substantially cylindrical shafts connected to the retainers 17 of both intake valves 13 at its tip. U
A cam slipper 38 is provided on the upper part of the opening side cam 30 for sliding contact with the opening side cam 30. Further, the tenth hook arm 33 has a pivot portion 33. A receiving portion 39 is integrally provided and projects from the side opposite to the intake valve 13. The 20th lever arm 34 is connected to the rocker arm shaft 32
A cam slot <40 extends upward from the pivot portion 34α that is indirectly pivoted to the pivot arm 34 so as to form a V-shaped angle with the tenth hook arm 33, and has a cam slot <40 at its tip that slides into contact with the closing side cam 31. provided. The 20th arm 34 has
A support portion 41 is provided to protrude above the receiving portion 39 of the tenth hook arm 33, and a screw hole 42 extending vertically is cut into the support portion 41. An adjustment screw 35 is screwed into the screw hole 42 so that it can move forward and backward.
5 comes into contact with the receiving portion 39 of the tenth hook arm 33. The first and 20th lever arms 33 and 34 are supported on the rocker arm shaft 32 between regulating steps 43 and 44 provided on the cylinder head 6, and a coil spring is connected between one regulating step 44 and the 20th lever arm 34. 45 is interposed.

The opening side cam 30 has a high portion 30α in the circumferential direction,
The closing side cam 31 has a high part 31 (Z) that spans most of the center angle, and a low part 31b that spans the remaining center angle, and The relative positions of the two cams 30, 31 are set accordingly.

In FIGS. 4 and 5, the pivot portion 33α of the tenth lock arm 33 has a 20th
A cylindrical boss 46 extending toward the claw arm 34 is integrally provided, and this boss 46 is connected to the 20th claw arm 34.
It is inserted into the pivot portion 34a of the. Therefore, the 20th lug arm 34 is swingably supported by the boss 46 of the 10th lug arm 33.

An oil supply passage 41 is concentrically formed in the rocker arm shaft 32, and a lubricating oil supply source (not shown) is connected to this oil supply passage 47. Further, an annular groove 48 is bored in the inner surface of the pivot portion 33α of the tenth hook arm 33, a communication hole 49 communicating with the annular groove 48 is bored in the rocker arm shaft 32, and the annular groove 48 and the annular groove 48 are bored in the rocker arm shaft 32. An oil passage 50 communicating with the working chamber 27 is bored. Also, the rocker arm shaft 3 is located at a position corresponding to the pivot portion 34a of the 20th hook arm 34.
An annular groove 51 is bored on the outer surface of the rocker arm shaft 3.
A communication hole 52 that communicates the oil supply path 4T and the annular groove 51 is bored in the side wall of the fuel tank 2. Furthermore, the boss 46 has an annular groove 51.
The oil passage 53 communicating with the 20th lug arm 34 is bored.
An oil passage 54 that can communicate the oil passage 53 and the working chamber 27 is bored in the pivot portion 34α. With this structure, lubricating oil is supplied into the working chamber 2T.

The pulp forced opening/closing device 24 for the exhaust valve 14 includes a cam shaft 55, an opening side cam 56, a closing side cam 57, a rocker arm shaft 58, a tenth lug arm 59, a twentieth lug arm 60, and an adjustment screw 61. It has the same structure as the pulp forced opening/closing device 23 for the intake pulp 13 described above.

Next, the operation of this embodiment will be explained. Since both pulp forced opening/closing devices 23 and 24 operate in the same way, the operation of only the pulp forced opening/closing device 23 for the intake valve 13 will be explained. When the high part 31α of the closing side cam 31 comes to a position corresponding to the cam slit horn 40 of the 20th claw arm 34 due to the operation, the 20th
The claw arm 34 rotates clockwise in FIG. 2 around the rocker arm shaft 32, and presses the tenth claw arm 33 clockwise in FIG. 2 via the adjustment screw 35. At this time, 1
10 The lower part 30h of the opening side cam 30 is located at the position corresponding to the cam slot 3B of the arm 33, and the first
The clockwise rotation of the zero tension arm 33 is allowed.

Therefore, the tenth lever arm 33 is the rocker arm shaft 3
2 in a clockwise direction to pull up the intake pulp 13, thereby closing the intake port 8.

Next, the high part 30α of the opening side cam 30 is set to the 10th latch.
When the tenth lever arm 33 comes into sliding contact with the cam slit 38 of the T-433, it is pushed down and rotated counterclockwise in FIG. The intake port 8 is opened by pressing down against the pressure.At this time, the lower part 31b of the closing side cam 31 is at a position corresponding to the cam slot 40 of the 20th latch arm 34, and Rotation of the 20th claw arm 340 due to the counterclockwise pressing force acting on the 20th claw arm 34 is allowed.

During such rocking motion of the first and 20th lever arms 33° 34, a pressing force is applied toward the rocker arm shaft 32 by lever action on each pivot portion 33α, 34α of the first and 20th lever arms 33, 34. do. However, the second
0 Tsuka arm 34 & 10th Tsuka arm 33 boss 46
The pressing forces of the double-ended hook arms 33 and 34 are mutually canceled out by the boss 46. Therefore, when the 20th lever arm 34 is pressed against the rocker arm shaft 32, force does not directly act on the rocker arm shaft 32, and friction loss is reduced.

6 and 7 show another embodiment of the present invention, in which the first and twentieth lever arms 3
3.34 pivot parts 33α, 34α are supported on the rocker arm shaft 32 via a cylindrical collar 62. Even in this case, force does not directly act on the rocker arm shaft 32 when pressing the first and twentieth hook arms 33, 34, and therefore friction loss is reduced.

As described above, according to the present invention, a cylindrical inclusion that is integrated with or slidably inserted into the other rocker arm is interposed between at least one rocker arm and the rocker arm shaft. Due to this action, when the double-ended hook arm is pressed against the rocker arm shaft, force is prevented from acting directly on the sliding part with the rocker arm shaft, and as a result,
Friction loss is reduced.

[Brief explanation of drawings]

Figures 1 to 5 show one embodiment of the present invention.
The figure is a side view of a motorcycle to which the device of the present invention is applied, FIG. 2 is an enlarged vertical sectional view of main parts, FIG. The figure is rv-iv in Figure 2.
5 is a sectional view taken along the line V-v in FIG. 4, FIGS. 6 and 7 show other embodiments of the present invention, and FIG. 6 is a sectional view corresponding to FIG. 4. 7 is a sectional view taken along the line ■--■ in FIG. 6, FIG. 8 is a sectional view showing essential parts of the conventional device, and FIG. 9 is a schematic diagram for explaining the operation of the conventional device. 13-° Intake pulp, 14...° Exhaust valve, 23°24... Pulp forced opening/closing device, 29.55... Camshaft, 30.56... Opening side cam, 31.57... Closed side cam, 32.58...Rocker arm shaft, 33.5
9... 10th Tsuka arm, 34. 60... 20th Tsuka arm, 46... Boss as an inclusion, 62...
Color patent as an inclusion Applicant: Honda Motor Co., Ltd. Figure 4 Figure 5 Figure 6 Figure 7 Figure 118 Figure 19 Procedure amendment form) 1. Indication of the case 1988 Patent Application No. 139193 2. Title of the invention: Valve forced opening/closing device for internal combustion engines 3. Relationship to the amended case Name of patent applicant (532) Honda Motor Co., Ltd. 4, Agent
Person 105 Telephone Tokyo 434-4151 5. Date of amendment order

Claims (3)

[Claims] (1) An opening side cam and a closing side cam adjacent to each other in the axial direction are integrated with a rotationally driven camshaft, and a tenth lug arm slidingly contacts the opening side cam and a tenth lug arm slidingly contacting the closing side cam. A 20th lever arm that interlocks with the camshaft is pivotably supported on a rocker arm axis parallel to the camshaft, and either one of the first and 20th lever arms is connected to an intake pulp or an exhaust pulp. In the opening/closing device, a cylindrical inclusion that is integrated with or slidably inserted into the other rocker arm is interposed between at least one rocker arm and the rocker arm shaft. Pulp forced opening/closing device. (2) The inclusion is a cylindrical boss that is integrally provided on one rocker arm that is directly pivotally supported on the rocker arm shaft and extends toward the other rocker arm, and the other rocker arm is pivotally supported on the boss. A pulp forced opening/closing device for an internal combustion engine according to claim (1), characterized in that: (3) The forced opening/closing of pulp for an internal combustion engine according to claim (1), wherein the inclusion is a cylindrical collar interposed between the double-ended hook arm and the rocker arm shaft. Device.