JP2008019737A - Valve gear of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To well restrain rotation around the axis of rocker arm shafts, in a valve gear of an internal combustion engine having the rocker arm shafts on a cylinder head. <P>SOLUTION: A cutout part 81 is formed on the respective rocker arm shafts 58 and 59, and a regulating plate 82 having a pair of rotation preventive parts 84 is arranged for regulating rotation of the respective rocker arm shafts 58 and 59. The regulating plate 82 is provided with a projection part 86 capable of pressing this plate, and is provided with a bolt inserting hole 85 long in the pressing direction. The regulating plate 82 is fixed to the cylinder head 24 by using a fastening bolt 83 inserted into the bolt inserting hole 85 in a state of bringing the respective rotation preventive parts 84 and the cutout part 81 into close contact with each other, by pressing the regulating plate 82 by using the projection part 86. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a valve operating apparatus for an internal combustion engine having a rocker arm shaft in a cylinder head.

2. Description of the Related Art Conventionally, the valve operating apparatus includes a regulating member that regulates the rotation of the rocker arm shaft around the axis, and presses the regulating member against the cylinder head with the inner wall of the cylinder head cover, and the rotation preventing portion of the regulating member is used as the rocker arm. There is one that is brought into contact with a notch formed in the shaft (see, for example, Patent Document 1).
JP 2004-285845 A

By the way, in the valve operating apparatus, an elastic body such as rubber is used to apply a pressing force to the regulating member, but this is applied when the cylinder head cover has a floating structure in order to improve soundproofing. It is difficult to improve such a point in order to suppress the generation of noise and the like due to the rotation (backlash) of the rocker arm shaft.
The present invention has been made in view of the above circumstances, and an object thereof is to satisfactorily suppress rotation of the rocker arm shaft around an axis in a valve operating apparatus for an internal combustion engine including a rocker arm shaft in a cylinder head.

  As a means for solving the above problems, the invention described in claim 1 is characterized in that a pair of rocker arm shafts (for example, the respective rocker arm shafts 58 and 59 of the embodiment) are spaced apart from each other in a cylinder head (for example, the cylinder head 24 of the embodiment). A pair of rocker arms (e.g., between the intake and exhaust cams (e.g., the respective cams 55a and 55b) and the intake and exhaust valves (e.g., the respective valves 51 and 52 of the embodiment). Each rocker arm 60, 61) of the embodiment is provided, and each rocker arm is swingably supported on each rocker arm shaft, and a notch (for example, the embodiment) is formed on a part of each rocker arm shaft. And a pair of detents (for example, around the embodiment) that regulate the rotation of the rocker arm shafts by contacting the notches. In a valve operating apparatus for an internal combustion engine (for example, the engine 20 of the embodiment) having a restriction member (for example, the restriction plate 82 of the embodiment) having a flange portion 84), the restriction member is separated from the rotation stoppers. A pressing portion (for example, the convex portion 86 of the embodiment) that can be pressed is provided on the side to be in close contact with the notch portion, and a bolt insertion portion (for example, the bolt insertion hole 85 of the embodiment) that is long in the pressing direction is provided. Using the fastening bolt (for example, the fastening bolt 83 in the embodiment) inserted through the bolt insertion portion in a state where the restricting member is pressed using a portion to bring the rotation preventing portion and the notch portion into close contact with each other. The restriction member is fixed to the cylinder head.

  The invention described in claim 2 is characterized in that the restricting member is fixed to the cylinder head or the cam holder (for example, the cam holder 71 of the embodiment) by the single bolt insertion portion and the fastening bolt.

  The invention described in claim 3 is characterized in that the pressing portion is located on a substantially extension in the longitudinal direction of the bolt insertion portion.

  According to the first aspect of the present invention, by pressing the restricting member so that the respective detent portions and the notch portions are brought into close contact with each other, the notch portions of the respective rocker arm shafts and the detent portions of the restricting members are provided. The clearance between the rocker arm shafts can be easily and reliably eliminated, and the rotation of each rocker arm shaft can be reliably suppressed by fixing the restricting member to the cylinder head with the fastening bolt in this state.

  According to the second aspect of the present invention, it is possible to easily attach and detach the restricting member to / from the cylinder head and improve the assembling property and the maintenance property.

  According to the invention described in claim 3, when the regulating member is pressed, it is difficult to tilt, the regulating member can be smoothly pushed into the cylinder head side, and each rocker arm shaft can be prevented from rotating well. .

  Embodiments of the present invention will be described below with reference to the drawings. Note that the directions such as front, rear, left and right in the following description are the same as those in the vehicle unless otherwise specified. In the figure, the arrow FR indicates the front of the vehicle, the arrow LH indicates the left side of the vehicle, and the arrow UP indicates the upper side of the vehicle.

  In the motorcycle (vehicle) 1 shown in FIG. 1, left and right front forks 5 that pivotally support the front wheels 4 are pivoted to a head pipe 3 positioned at the front end portion of the vehicle body frame 2 via a steering stem 6. Be supported. A steering bar handle 7 is attached to the upper portion of the steering stem 6.

  The vehicle body frame 2 is a so-called backbone type in which one main tube 8 is extended obliquely downward and rearward from the head pipe 3 and the stride between the head pipe 3 and the occupant seat 9 is lowered to improve the ease of straddling. The The left and right pivot plates 10 are joined to the rear end portion of the main tube 8, and the front end portion of the swing arm 12 that pivotally supports the rear wheel 11 is pivotally supported on the left and right pivot plates 10.

  The front ends of the left and right seat frames 13 extending obliquely upward and rearward are joined to the rear portion of the main tube 8, and between the front and rear intermediate portions of the left and right seat frames 13 and the left and right arm rear ends of the swing arm 12, Left and right rear cushions 14 are respectively disposed. Above the left and right seat frames 13, the seat 9 having front and rear seat surfaces for a driver and a rear passenger is disposed. In the figure, reference numeral 15 denotes a driver step, and reference numeral 16 denotes a rear passenger step.

  An engine (internal combustion engine) 20, which is a prime mover of the motorcycle 1, is disposed inside the center lower part of the body frame 2 (inside the lower part). The engine 20 is an air-cooled single-cylinder engine having a crank axis line along the vehicle width direction (left-right direction), and has a basic configuration in which a cylinder portion 22 is erected from the front end portion of the crankcase 21 toward the front of the vehicle. The engine 20 is supported by the left and right pivot plates 10 at the rear upper and lower portions of the crankcase 21, and the upper portion of the crankcase 21 is supported by the front and rear intermediate portions of the main tube 8 via the engine hanger 8a. Suspended by.

  The cylinder head 24 on the front end side (front end side) of the cylinder portion 22 is connected to the downstream side of the throttle body 26 from above and to the base end side of the exhaust pipe 27 from below. An air cleaner case 26 a supported on the lower front side of the main tube 8 is connected to the upstream side of the throttle body 26.

  The exhaust pipe 27 is bent forward at one end under the cylinder head 24 and then folded back and extends, and is connected to the front end (base end) of the silencer 27a located behind the engine 20. A catalytic converter 28 for purifying exhaust gas is provided in a portion of the exhaust pipe 27 located below the cylinder portion 22.

  Rotational power from the engine 20 is output to the drive sprocket 32 on the left rear side of the crankcase 21 via the clutch and transmission in the crankcase 21, and from the drive sprocket 32 to the left side of the rear wheel 11 via the drive chain 33. It is transmitted to the driven sprocket 34.

  The front part of the body frame 2, the cylinder part 22 of the engine 20, the throttle body 26, the air cleaner case 26a, and the like are covered with a front body cover 35 made of synthetic resin. The front body cover 35 also serves as a leg shield that protects the driver's legs from wind pressure and the like from the front. The rear portion of the vehicle body frame 2 is covered with a rear vehicle body cover 36 that is also made of synthetic resin. The rear body cover 36 supports the seat 9 together with the left and right seat frames 13. An article storage box 37 located below the seat 9 is disposed in the rear body frame 2, and a fuel tank 38 supported by the front portions of the left and right seat frames 13 is disposed below the front part of the article storage box 37. Is done.

  2 and 3 together, the cylinder portion 22 of the engine 20 has its axis line (cylinder axis line) C substantially horizontal (in detail, slightly lifted forward) and forward (from the front end of the crankcase 21) ( It protrudes in the vehicle traveling direction). The cylinder portion 22 includes a cylinder body 23 attached to the front end portion of the crankcase 21, the cylinder head 24 attached to the front end portion of the cylinder body 23, and a cylinder head cover attached to the front end portion of the cylinder head 24 (hereinafter simply referred to as “cylinder head cover”). 25, which is sometimes referred to as a head cover). Hereinafter, the front-rear direction along the axis C in the cylinder portion 22 may be referred to as a cylinder front-rear direction, and the up-down direction perpendicular to the axis C may be referred to as a cylinder up-down direction.

The cylinder head 24, the cylinder body 23, and the camshaft holder 71 (see FIGS. 4 to 6, hereinafter referred to as the cam holder 71) are integrally coupled to the crankcase 21 by a plurality of bolts penetrating them from the front of the vehicle. . The cylinder head cover 25 is fixed to the cylinder head 24 (cam holder 71) with a plurality of bolts inserted from the front of the vehicle.
A cylinder bore 39 is formed in the cylinder body 23 along the cylinder axis C, and a piston 40 is fitted in the cylinder bore 39 so as to be able to reciprocate. The piston 40 is connected to the crankshaft 42 via the connecting rod 41, and the reciprocating motion of the piston 40 is converted into the rotational motion of the crankshaft 42. Hereinafter, the rotation axis (crank axis) of the crankshaft 42 is C1.

  The cylinder head 24 closes the front end opening of the cylinder bore 39 and forms a combustion chamber together with the piston 40. The engine 20 in this embodiment is of the OHC two-valve type, and the combustion chamber roof forming portion 48 is formed with a single combustion chamber side opening at the intake port 49 or the exhaust port 50, and each of these combustion chamber side openings is formed. They are opened and closed by an intake valve 51 or an exhaust valve 52, respectively.

  Each port 49, 50 is a flow passage that communicates the combustion chamber with the intake side attachment portion 53 at the upper part of the cylinder head 24 or the exhaust side attachment portion 54 at the lower part of the cylinder head 24, and extends obliquely forward from the opening on the combustion chamber side. Then, it curves upward or downward to reach the intake side attachment portion 53 or the exhaust side attachment portion 54. An insulator of the throttle body 26 or a coupling flange of the exhaust pipe 27 is fastened to the upper surface portion of the intake side attachment portion 53 or the lower surface portion of the exhaust side attachment portion 54, respectively.

As shown in FIG. 2, each valve 51, 52 is formed by extending a rod-shaped stem obliquely forward from an umbrella-shaped valve body aligned with the combustion chamber side opening of each port 49, 50. Each stem extends in a V-shape when viewed from the side of the cylinder, and the tip end of the stem protrudes into the valve operating chamber on the cylinder head 24.
The spring force of the valve spring is input to the distal end side of each stem via a retainer, and the valve body is urged upward by the spring force to close the combustion chamber side openings of the ports 49 and 50. On the other hand, by moving the stems (the valves 51 and 52) downward against the spring force of the valve springs, the valve bodies are separated from the combustion chamber side openings of the ports 49 and 50 to open them. Let

3 and 4, a single camshaft 55 that is parallel to the crankshaft 42 is disposed between the stems of the valves 51 and 52. The camshaft 55 is integrally provided with an intake cam 55a and an exhaust cam 55b at its longitudinal intermediate portion, and both ends thereof are rotatably supported by the cam holder 71 via left and right ball bearings 72 and 73. Hereinafter, the rotation axis of the camshaft 55 is C2.
A driven sprocket 56a is coaxially fixed to the left end portion of the camshaft 55, and an endless cam chain 56c is wound between the driven sprocket 56a and a drive sprocket 56b provided on the crankshaft 42. Is rotated in conjunction with the crankshaft 42. A decompression cam 57 that opens the exhaust valve 52 during the compression process when the engine 20 is started is provided on the right side of the exhaust cam 55b in the camshaft 55 (see FIG. 4).

On the side of the head cover 25 of the camshaft 55, intake side and exhaust side rocker arm shafts 58 and 59 that are parallel to the camshaft 55 are arranged in parallel in the front-rear direction at a distance from each other. Each rocker arm shaft 58, 59 is made of a steel material having a circular cross section, and is inserted and supported by the cam holder 71, respectively. In the rocker arm shafts 58 and 59, the intermediate portions of the intake side or exhaust side rocker arms 60 and 61 extending across the corresponding cams 55a and 55b and the stem tips of the valves 51 and 52 are swingable. Supported. Hereinafter, the axis of each rocker arm shaft 58, 59 is C3.
As the camshaft 55 rotates, the rocker arms 60 and 61 swing according to the outer peripheral pattern of the cams 55a and 55b, so that the valves 51 and 52 reciprocate along the stem. The combustion chamber side opening of the ports 49 and 50 is opened and closed.

  As shown in FIGS. 4 to 6, the cam holder 71 has left and right support wall portions 74 and 75 that stand so as to be substantially orthogonal to the camshaft 55, and the left and right end portions of the camshaft 55 are disposed on the left and right support wall portions 74 and 75. The part is rotatably supported via ball bearings 72 and 73. The cam holder 71 has intake side and exhaust side shaft support parts 76, 77 extending between the left and right support wall parts 74, 75. Each shaft support part 76, 77 has a bag-like insertion hole that opens to the left. 76a and 77a are formed, and the rocker arm shafts 58 and 59 are detachably inserted into the insertion holes 76a and 77a from the left side.

  The rocker arm shafts 58 and 59 are moved to the right in a state where the rocker arm shafts 58 and 59 are inserted to the shaft support portions 76 and 77 to a predetermined depth by substantially abutting the right end portions thereof on the bottom portions of the insertion holes 76a and 77a. Be regulated. At this time, the rocker arm shafts 58 and 59 project their left end portions to the left from the insertion holes 76a and 77a. In this state, each of the rocker arm shafts 58 and 59 can move leftward, that is, in the direction in which the rocker arm shafts 58 and 59 are detached from the shaft support portions 76 and 77, and around its own axis (centering on the axis C3). ) It can be rotated.

  The intake-side rocker arm 60 is disposed on the left side of the exhaust-side rocker arm 61. Accordingly, the left end portions of the intake-side rocker arm shaft 58 and the insertion hole 76a are connected to the exhaust-side rocker arm shaft 59 and the insertion hole 77a. Terminate to the left of the left edge. A stopper mechanism 57a for restricting the rotation of the decompression cam 57 in one direction is disposed on the left side of the exhaust rocker arm shaft 59 and the left end of the insertion hole 77a.

  The engine 20 is twin plugged to improve combustion performance and improve output and fuel efficiency. A first spark plug 64 is attached to the lower part of the cylinder head 24 from diagonally forward and downward, and a second spark plug 65 is attached to the left side of the cylinder head 24 from diagonally forward and right. First or second plug holes 66 and 67 for allowing the spark plugs 64 and 65 to reach the roof forming portion 48 are formed in the lower portion and the left portion of the cylinder head 24, respectively. The cylinder head 24 is formed with an air jacket 69 for circulating cooling air (running air) around the plug holes 66 and 67 so that the inside (especially around the plug holes 66 and 67) can be effectively cooled. Is done.

  The left end portion of the camshaft 55 constitutes a left journal 78, and the inner race of the left ball bearing 72 is fixed to the outer periphery of the left journal 78 by press fitting or the like, and the outer race of the left ball bearing 72 is a left support wall portion. 74 is detachably inserted into the support hole 74a from the left side. On the left side of the left journal 78, a plurality of bosses for mounting the driven sprocket 56a are provided. On the other hand, a right journal 79 protrudes to the right of the right end portion of the camshaft 55, and the outer periphery of the right journal 79 is inserted into the right ball bearing 73, which is press-fitted into a support recess 75 a of the right support wall 75. Is detachably inserted.

  The cam shaft 55 can be inserted into and removed from the cam holder 71 together with the left ball bearing 72 from the left side. Accordingly, the left ball bearing 72 has a larger diameter than the right ball bearing 73, and the left ball bearing 72 is Since the support hole 74a of the left support wall 74 to be supported has a large diameter, the cams 55a and 55b of the cam shaft 55 can pass through the support hole 74a.

Here, at one end portion (left end portion) of each of the rocker arm shafts 58 and 59, a notch portion 81 is formed by notching it into a semicircular cross section. Hereinafter, a plane substantially parallel to the axis C3 in the notch portion 81 of each rocker arm shaft 58, 59 is referred to as a notch plane 81a, and an end face substantially orthogonal to the axis C3 is referred to as a notch end face 81b. Each of the rocker arm shafts 58 and 59 is inserted and supported by the cam holder 71 so that the notch plane 81a faces the head cover 25 (specifically, the notch plane 81a is substantially parallel to the cylinder vertical direction). In other words, each notch 81 is formed by notching the head cover 25 side of one end of each rocker arm shaft 58, 59.
Each notch 81 is formed such that the notch end surface 81 b is substantially flush with the left side surface of the cam holder 71 in a state where the rocker arm shafts 58 and 59 are inserted into the cam holder 71.

The rotation of the rocker arm shafts 58 and 59 around the axis (rotation about the axis C3) and the leftward movement in the axial direction (movement to the left along the axis C3) are restricted to the left side of the cam holder 71. It is regulated by the plate 82.
The restricting plate 82 is a flat plate made of, for example, a flat steel plate, is disposed so as to be substantially orthogonal to the axes C2 and C3, and has a single side surface (right side surface) in contact with the left side surface of the cam holder 71. A single fastening bolt 83 fixes the cam holder 71 and the cylinder head 24. Instead of the regulation plate 82, a regulation member having irregularities, a bent shape, or the like may be provided.

  Referring also to FIG. 7, the restriction plate 82 has an isosceles triangle shape in which the dimension in the height direction (cylinder longitudinal direction) is suppressed in the plan view (cylinder side view), and the width direction (cylinder vertical direction). ) In both sides of the rocker arm shafts 58 and 59, respectively.

  Each anti-rotation portion 84 restricts the rotation of the rocker arm shafts 58 and 59 around the axis by bringing the edge portion 84a on the cylinder head 24 side into contact with the notch plane 81a of the corresponding notch portion 81. . Further, each detent portion 84 is provided so as to substantially overlap the entire corresponding notch end surface 81b in a side view of the cylinder, and one side surface thereof is brought into contact with the notch end surface 81b of the corresponding notch portion 81. The movement of the rocker arm shafts 58 and 59 to the left, that is, the movement in the direction of removal from the cam holder 71 is also restricted.

  A single bolt insertion hole 85 having an elliptical shape that is long in the height direction (the direction along the cylinder axis C, the cylinder axis direction) is formed at the center in the width direction of the restriction plate 82. The fastening bolt 83 is inserted into the bolt insertion hole 85 and screwed into the screw hole 85a of the cam holder 71, and the restriction plate 82 and the fastening bolt 83 are temporarily fixed to the cam holder 71. A predetermined amount can be moved to the cylinder head 24 side or the head cover 25 side along the height direction with respect to the position. Instead of the bolt insertion hole 85, for example, a slit-like bolt insertion portion may be provided.

  On the head cover 25 side (substantially on the same straight line as the long axis of the bolt insertion hole 85) at the center in the width direction of the restriction plate 82, a substantially square shape is projected from the triangular top in the plan view and protrudes toward the head cover 25. A convex portion 86 is formed. The convex portion 86 is provided such that the tip portion on the cylinder head 24 side substantially overlaps the end portion on the cylinder head 24 side of the cam holder 71 in a side view of the cylinder. By pushing such a convex portion 86 into the cylinder head 24 side in a state where the fastening bolt 83 is loosened, the entire restriction plate 82 can be pressed toward the cylinder head 24 side.

  In the pressed state, the restriction plate 82 moves to the cylinder head 24 side within the range of the movement allowance corresponding to the elliptical shape of the bolt insertion hole 85, and the rocker arm shaft corresponding to the edge portion 84 a of each detent portion 84. The cutout portions 81 of the 58 and 59 are brought into close contact with the cutout plane 81a. Further, by tightening the fastening bolt 83 in this state, the regulating plate 82 brings one side surface of each rotation stopper portion 84 into close contact with the notch end surface 81 b of the corresponding notch portion 81. In other words, the restriction plate 82 is fixed to the cylinder head 24 in a state where there is no clearance between the rotation stoppers 84 of the restriction plate 82 and the notches 81 of the rocker arm shafts 58 and 59.

  Further, on the cylinder head 24 side in the center in the width direction of the regulating plate 82, a head-side convex portion that protrudes toward the cylinder head 24 from the triangular base in the plan view and wider than the convex portion 86. 87 is formed. The head-side convex portion 87 is formed in an arc shape so that the tip portion on the cylinder head 24 side substantially overlaps the upper portion of the outer race of the left ball bearing 72 in a side view of the cylinder. Then, in a state where the regulating plate 82 is fixed to the cylinder head 24, the head-side convex portion 87 is brought into contact with the left side surface of the upper portion of the outer race of the left ball bearing 72, so that the left ball bearing 72 As a result, the movement of the entire cam shaft 55 to the left, that is, the movement in the direction of removal from the cam holder 71 is restricted.

  As described above, in the valve operating apparatus for an internal combustion engine in the above embodiment, a pair of rocker arm shafts 58 and 59 are arranged in parallel in the cylinder head 24 so as to be spaced apart from each other, and the intake and exhaust cams 55a and 55b. A pair of rocker arms 60 and 61 straddling between the exhaust valves 51 and 52 is provided, and the rocker arms 60 and 61 are swingably supported on the rocker arm shafts 58 and 59, respectively. A notch portion 81 is formed in a part of each rocker arm shaft 58, 59, and the rocker arm shafts 58, 59 are rotated in contact with the notch portion 81. A restriction plate 82 having a pair of anti-rotation portions 84 to be restricted is provided, and the restriction plate 82 is separated from the anti-rotation portions 84 with the restriction plate 82. A convex portion 86 that can be pressed is provided on the side to be in close contact with the notch portion 81, and a bolt insertion hole 85 that is long in the pressing direction is provided. The restriction plate is moved by using a fastening bolt 83 inserted into the bolt insertion hole 85 in a state where the rotation preventing portion 84 and the notch portion 81 are brought into close contact with each other along the longitudinal direction of the bolt insertion hole 85. 82 is fixed to the cylinder head 24.

  According to this configuration, the restricting plate 82 is pressed so that the respective detents 84 and the notches 81 are brought into close contact with each other, so that the notches 81 and the restricting plates 82 of the respective rocker arm shafts 58 and 59 are rotated. The clearance with the stopper 84 can be easily and reliably eliminated, and in this state, the restricting plate 82 is fixed to the cylinder head 24 with the fastening bolt 83 to ensure the rotation of the rocker arm shafts 58 and 59. Can be suppressed. Further, since each rotation preventing portion 84 abuts against the notch end surface 81b of each rocker arm shaft 58, 59, the rocker arm shaft 58, 59 can be prevented from coming off from the cam holder 71, and the head side convex portion 87 is provided. By coming into contact with the outer race of the left ball bearing 72, it is possible to prevent the left ball bearing 72 and thus the camshaft 55 from coming off from the cam holder 71.

  In the valve operating apparatus, the restriction plate 82 is fixed to the cam holder 71 by the single bolt insertion hole 85 and the fastening bolt 83, so that the restriction plate 82 can be easily attached to and detached from the cylinder head 24. Thus, the assembling property and the maintenance property can be improved. In the cylinder head in which the camshaft holder is integrally formed, the restriction plate 82 may be directly fixed to the cylinder head.

  Furthermore, in the valve operating device, the convex portion 86 is positioned on a substantially extension in the longitudinal direction of the bolt insertion hole 85, so that when the restriction plate 82 is pressed, it is difficult to tilt, and the restriction plate 82 is moved to the cylinder. The rocker arm shafts 58 and 59 can be prevented from being rotated well by being smoothly pushed into the head 24 side.

The present invention is not limited to the above-described embodiments, and is applied to, for example, a four-valve engine, an engine having a different number of intake / exhaust valves, or a DOHC engine having two camshafts for intake / exhaust in a cylinder head. Alternatively, it may be applied to a multi-cylinder engine or a water-cooled engine.
The configuration in the above embodiment is an example of the present invention, and it can be applied to various vehicles such as a scooter type vehicle, as well as various modifications can be made without departing from the gist of the present invention. Nor.

1 is a left side view of a motorcycle according to an embodiment of the present invention. It is a right view of the said engine. It is an expanded sectional view of the above-mentioned engine. It is a principal part enlarged view of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is explanatory drawing around the control plate of the said engine, (a) is a principal part enlarged view of FIG. 5, (b) It is AA sectional drawing of (a).

Explanation of symbols

1 Motorcycle (vehicle)
20 engine (internal combustion engine)
24 Cylinder head 51 Intake valve (intake valve)
52 Exhaust valve (exhaust valve)
55a Intake cam 55b Exhaust cam 58 Intake side rocker arm shaft (rocker arm shaft)
59 Exhaust-side rocker arm shaft (rocker arm shaft)
60 Intake side rocker arm (rocker arm)
61 Exhaust-side rocker arm (rocker arm)
71 Camshaft holder (cam holder)
81 Notch 82 Restriction plate (regulation member)
83 Fastening bolt 84 Non-rotating part 85 Bolt insertion hole (bolt insertion part)
86 Convex part (pressing part)

Claims (3)

A pair of rocker arm shafts are arranged in parallel in the cylinder head with a space between each other, and a pair of rocker arms straddling between the intake and exhaust cams and the intake and exhaust valves are provided, and each rocker arm is connected to each rocker arm. A pair of rockers that are swingably supported on each of the shafts, and that have a notch formed in a part of each of the rocker arm shafts, and that are in contact with the notch portions and restrict the rotation of the rocker arm shafts. In a valve operating apparatus for an internal combustion engine provided with a regulating member having a rotation stopper,
The restricting member is provided with a pressing portion that can press the rotation preventing portion and the notch portion in close contact with each other, and a bolt insertion portion that is long in the pressing direction is provided, and the pressing portion is used to The regulating member is fixed to the cylinder head by using a fastening bolt inserted into the bolt insertion portion in a state where the regulating member is pressed and the rotation preventing portions and the notch portions are brought into close contact with each other. A valve operating apparatus for an internal combustion engine. The valve operating apparatus for an internal combustion engine according to claim 1, wherein the restricting member is fixed to the cylinder head or the cam holder by a single bolt insertion portion and a fastening bolt. 3. The valve operating apparatus for an internal combustion engine according to claim 1, wherein the pressing portion is positioned on a substantially extension in a longitudinal direction of the bolt insertion portion.

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