JP6449930B2 - Valve operating device for internal combustion engine - Google Patents

Description

  The present invention relates to a valve gear for an internal combustion engine.

Conventionally, a camshaft that rotates in synchronization with the rotation of the internal combustion engine, a drive cam that rotates integrally with the camshaft, a valve cam that rotates relative to the camshaft to open and close the engine valve, and a valve driving force of the drive cam And a holder member that supports the support shaft of the link mechanism and can swing around the cam shaft. The operating characteristics of opening and closing the engine valve by swinging the holder member There is known a valve gear for an internal combustion engine in which the change is made (for example, see Patent Document 1).
In Patent Document 1, the holder member includes left and right holder plates and a connecting member that is provided between the left and right holder plates and connects the holder plates, and the support shaft of the link mechanism is formed on the connecting member. Yes.

JP 2010-229939 A

By the way, in the conventional valve operating apparatus for an internal combustion engine, it is desired to simplify and downsize the structure of the valve operating apparatus.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to make the structure of a valve gear for an internal combustion engine simple and small.

  The present invention relates to a camshaft (52) that rotates in synchronization with the rotation of the internal combustion engine (11), a drive cam (58) that rotates integrally with the camshaft (52), and a relative to the camshaft (52). A valve cam (72) that rotates and opens and closes the engine valve (45), a link mechanism (73) that transmits the valve driving force of the drive cam (58) to the valve cam (72), and the link mechanism A holder member (71) that supports the support shaft (74) of (73) and can swing around the cam shaft (52), and the engine valve is moved by swinging the holder member (71). In the valve operating apparatus for an internal combustion engine in which the opening / closing operation characteristics of (45) are changed, the holder member (71) includes a one side holder (81) and another side holder (82) which are joined in contact with each other. The supporting shaft (74) of the link mechanism (73) The link mechanism (73) is disposed between the one side holder (81) and the other side holder (82), and is inserted into and supported by a rudder (81) and the other side holder (82). It is characterized by that.

In the above invention, the link mechanism (73) connects the sub rocker arm (77) coupled to the support shaft (74), the sub rocker arm (77), and the valve cam (72). The sub-rocker arm (77) is connected to the bearing portion (96) through which the support shaft (74) is inserted, and the link (78) is connected to the sub-rocker arm (77). A link connecting part (97) provided with a link connecting shaft (101) to be provided, and the link connecting part (97) may be provided within a width (H1) of the bearing part (96).
In the above invention, the sub rocker arm (77) is provided with a roller (98) that contacts the drive cam (58), and the roller (98) contacts the drive cam (58). A return spring (75) for urging the sub-rocker arm (77) is provided, and the sub-rocker arm (77) is a linear portion that linearly connects the bearing portion (96) and the link connecting portion (97). (100), the return spring (75) is disposed on one side of the linear portion (100), and the roller (98) is disposed on the other side of the linear portion (100). It is good also as a structure.

Furthermore, in the above invention, the sub rocker arm (77) includes a roller storage portion (102) in which the roller (98) is stored in the width (H1) of the bearing portion (96), and the roller storage. The part (102) may be opened outward from a notch part (104) formed in the bearing part (96).
In the above invention, a return spring (75) for urging the sub rocker arm (77) toward the drive cam (58) is provided, and the one side holder (81) and the other side holder (82) are provided. On the other hand, it is good also as a structure provided with the accommodating part (94) which accommodates the said return spring (75).
Moreover, in the said invention, a concave oil receiving part (110) is formed in the holder (81) provided with the said accommodating part (94) among the said one side holder (81) and the said other side holder (82). It is good also as the structure currently made.

In the above invention, the holder (81) provided with the storage portion (94) is connected to the oil passage (111) for communicating the oil receiving portion (110) with the hollow portion (74b) of the support shaft (74). ), And the support shaft (74) may include an oil hole (74c) that allows the hollow portion (74b) to communicate with the link mechanism.
Furthermore, in the above invention, the support shaft (74) includes a spring locking hole (74a) extending in a radial direction of the support shaft (74), and the holder member (71) includes the spring locking hole (74a). ) Is provided with a valve drive cam return spring (76) for urging the valve drive cam (72), and one end (76b) of the valve drive cam return spring (76) is The other end (76c) of the valve cam return spring (76) is inserted into the insertion hole (83a) and the spring locking hole (74a). It is also good.

According to the valve operating apparatus for an internal combustion engine according to the present invention, the link mechanism that transmits the valve driving force of the cam cam driving cam to the valve operating cam, the support shaft of the link mechanism is supported, and the cam shaft swings around the cam shaft. The holder member includes a one side holder and another side holder that are in contact with each other, and the support shaft of the link mechanism is inserted into and supported by the one side holder and the other side holder. The link mechanism is disposed between the one side holder and the other side holder.
Accordingly, the holder member can be configured with a small number of parts, and the link mechanism can be compactly disposed between the one side holder and the other side holder. Further, since the support shaft is inserted into the one side holder and the other side holder, the support shaft can be formed in a simple shape and can be provided with high accuracy. Furthermore, since the one side holder and the other side holder are brought into contact with each other and coupled, the rigidity of the holder member can be improved.

In the above invention, the link mechanism includes a sub rocker arm coupled to the support shaft and a link connecting the sub rocker arm and the valve cam, and the sub rocker arm has a bearing portion through which the support shaft is inserted. And a link connecting portion provided with a link connecting shaft for connecting the link to the sub rocker arm, and the link connecting portion may be provided within the width of the bearing portion. According to this configuration, since the link connecting portion is provided within the width of the bearing portion in the sub rocker arm, the torsional moment between the bearing portion and the link connecting portion can be reduced, and the link mechanism operates favorably. be able to.
In the above invention, the sub rocker arm is provided with a roller that contacts the drive cam, a return spring that biases the sub rocker arm so that the roller contacts the drive cam, and the sub rocker arm includes a bearing portion. And a link connecting part in a straight line, the return spring may be arranged on one side of the linear part, and the roller may be arranged on the other side of the linear part. According to this configuration, since the sub rocker arm includes the straight portion, the torsional moment generated in the sub rocker arm can be reduced. Further, the return spring and the roller can be separately arranged on both sides of the linear portion, so that the compactness can be achieved.

Furthermore, in the above invention, the sub rocker arm includes a roller storage portion in which the roller is stored within the width of the bearing portion, and the roller storage portion may be opened outward from a notch portion formed in the bearing portion. good. According to this configuration, it is possible to secure a large width of the bearing portion, and it is possible to process the roller storage portion from the space of the notch portion, so that the roller storage portion can be formed easily and with high accuracy.
In the above invention, a return spring for urging the sub rocker arm toward the drive cam may be provided, and a storage portion for storing the return spring may be provided in one of the one side holder and the other side holder. According to this configuration, the storage portion can be integrated into one of the one side holder and the other side holder, and the structure of the holder member can be simplified.

Moreover, in the said invention, the concave oil receiving part may be formed in the holder provided with the accommodating part among the one side holder and the other side holder. According to this structure, an oil receiving part can be enlarged using the size of the holder in which an accommodating part is provided.
In the above invention, the holder provided with the storage portion includes an oil passage that allows the oil receiving portion to communicate with the hollow portion of the support shaft, and the support shaft includes an oil hole that allows the hollow portion to communicate with the link mechanism. Also good. According to this configuration, the oil collected in the oil receiving portion can be supplied to the link mechanism with a simple structure via the oil passage of the holder, the hollow portion of the support shaft, and the oil hole.
Further, in the above invention, the support shaft includes a spring locking hole extending in a radial direction of the support shaft, and the holder member includes an insertion hole continuing to the spring locking hole and biases the valve operating cam. A return spring may be provided, one end of the valve cam return spring may be connected to the valve cam, and the other end of the valve cam return spring may be inserted into the insertion hole and the spring locking hole. According to this configuration, the valve drive cam return spring can be fixed with a simple structure in which the other end of the valve drive cam return spring is inserted into the insertion hole and the spring locking hole. Further, the support shaft can be prevented from rotating by the other end of the valve drive cam return spring.

1 is a right side view of a motorcycle according to an embodiment of the present invention. It is sectional drawing which shows the internal structure of a front side cylinder part. It is a perspective view of a valve gear. It is the top view which looked at the valve operating apparatus from upper direction. It is the perspective view which looked at the front side cylinder part from the upper side in the state where the cylinder head cover was removed. It is VI-VI sectional drawing of FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. It is VIII-VIII sectional drawing of FIG. It is IX-IX sectional drawing of FIG. FIG. 10 is a plan view of the sub-rocker arm. FIG. 4 is a view of the variable mechanism as viewed in the axial direction of the camshaft from the sprocket fixing portion side in FIG. 3.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description, descriptions of directions such as front and rear, right and left and up and down are the same as directions with respect to the vehicle body unless otherwise specified. Further, in each figure, the symbol FR indicates the front of the vehicle body, the symbol UP indicates the upper side of the vehicle body, and the symbol LH indicates the left side of the vehicle body. In the drawing, the right side of the vehicle body may be indicated by the symbol RH, and the rear of the vehicle body may be indicated by the symbol RE.

FIG. 1 is a right side view of a motorcycle according to an embodiment of the present invention.
In the motorcycle 1, an engine 11 (internal combustion engine) as a power unit is supported on a body frame 10, and a front fork 12 that supports a front wheel 2 in a steerable manner is supported on a front end of the body frame 10 in a steerable manner. The swing arm 13 to be supported is a vehicle provided on the rear side of the body frame 10. The motorcycle 1 is a saddle-ride type vehicle in which a seat 14 on which an occupant sits is provided above the rear portion of the body frame 10.

  The vehicle body frame 10 is bent after extending downward from the head pipe 15, a main frame 16 extending rearward and downward from the head pipe 15, a pair of left and right pivot frames 17 connected to the rear portion of the main frame 16, and And a down frame 18 extending rearward and connected to the pivot frame 17.

The front fork 12 is pivotally supported on the head pipe 15. A steering handle 20 operated by the occupant is provided at the upper end of the front fork 12. The front wheel 2 is pivotally supported at the lower end of the front fork 12.
The swing arm 13 is supported by a pivot shaft 21 provided on the pivot frame 17 and extends rearward. The rear wheel 3 is pivotally supported on the rear end portion of the swing arm 13. A rear suspension 22 is spanned between the swing arm 13 and the vehicle body frame 10.

The engine 11 is disposed below the main frame 16 and between the down frame 18 and the pivot frame 17.
The engine 11 includes a crankcase 26 that supports a crankshaft 25 extending in the vehicle width direction, a front cylinder portion 27 that extends forward and upward from the upper portion of the crankcase 26, and a rear portion of the crankcase 26 that is located behind the front cylinder portion 27. And a rear cylinder portion 28 extending upward.
A transmission 29 that decelerates and transmits the rotation of the crankshaft 25 is built in the crankcase 26 behind the crankshaft 25. The driving force of the engine 11 is transmitted to the rear wheel 3 by a drive shaft (not shown) that connects the transmission 29 and the rear wheel 3.

The engine 11 is a V-type engine formed such that the front cylinder portion 27 and the rear cylinder portion 28 are V-shaped when the crankshaft 25 is viewed in the axial direction (vehicle side view). Specifically, the engine 11 is a V-type four-cylinder engine that includes two cylinders in the front cylinder portion 27 and the rear cylinder portion 28, respectively.
The intake device 30 of the engine 11 is disposed in a V-shaped space between the front cylinder portion 27 and the rear cylinder portion 28.
The exhaust device 31 of the front cylinder part 27 is drawn downward from the front part of the front cylinder part 27 and extends rearward. The exhaust device 32 of the rear cylinder portion 28 is pulled out from the rear portion of the rear cylinder portion 28 and extends rearward.
The fuel tank 33 is disposed above the main frame 16.

FIG. 2 is a cross-sectional view showing the internal structure of the front cylinder portion 27. Since the front cylinder part 27 and the rear cylinder part 28 are configured similarly, the front cylinder part 27 will be described in detail here, and the description of the rear cylinder part 28 will be omitted. FIG. 2 is a cross section of one of the two cylinders of the front cylinder portion 27 aligned in the vehicle width direction.
The front cylinder portion 27 includes a cylinder block 35, a cylinder head 36, and a cylinder head cover 37 in order from the crankcase 26 side.

A piston 38 is disposed in the cylinder bore 35 a of the cylinder block 35. The piston 38 is connected to the crankshaft 25 (FIG. 1) via a connecting rod 39.
A combustion recess 40 a that forms the top surface of the combustion chamber 40 formed above the piston 38 is formed on the lower surface of the cylinder head 36. A spark plug 41 is disposed in the cylinder head 36 with its tip exposed in the combustion chamber 40. The spark plug 41 is provided substantially coaxially with the cylinder axis C of the cylinder bore 35a.

The engine 11 is an in-cylinder injection engine that directly injects fuel from the injector 42 into the combustion chamber 40.
The cylinder head 36 includes an intake port 43 that allows the intake device 30 to communicate with the combustion chamber 40 via the opening 43a, and an exhaust port 44 that allows the combustion chamber 40 to communicate with the exhaust device 31 via the opening 44a.

The cylinder head 36 is provided with an intake valve 45 (engine valve) for opening and closing the opening 43 a of the intake port 43 and an exhaust valve 46 (engine valve) for opening and closing the opening 44 a of the exhaust port 44. The intake valve 45 and the exhaust valve 46 are arranged so as to be spaced apart from each other so as to have a predetermined valve clamping angle, and are arranged separately on the front and rear sides with the cylinder axis C in a side view.
The intake valve 45 and the exhaust valve 46 are urged by valve springs 45 a and 46 a arranged in the cylinder head 36 in the direction of closing the opening 43 a of the intake port 43 and the opening 44 a of the exhaust port 44.

  The cylinder head 36 is provided with a valve operating device 50 that drives the intake valve 45 and a valve operating device 51 that drives the exhaust valve 46. Since the valve gear 50 and the valve gear 51 are configured substantially symmetrically with respect to the cylinder axis C in FIG. 2, the intake side valve gear 50 will be described in detail here.

FIG. 3 is a perspective view of the valve gear 50. FIG. 4 is a plan view of the valve gear 50 as viewed from above.
2 to 4, the valve operating apparatus 50 includes a camshaft 52 that is rotated by a driving force of the crankshaft 25 (FIG. 1), a variable mechanism 70 that is disposed around the camshaft 52, and a variable mechanism 70. And a drive mechanism 54 (FIG. 5) that changes the swing position of the variable mechanism 70 by swinging (turning) the variable mechanism 70. Prepare.
The cam shaft 52 and the crankshaft 25 are arranged in parallel, and an axis 52a of the camshaft 52 extends in the vehicle width direction in parallel with the crankshaft 25.

  Specifically, the front cylinder portion 27 has one cylinder and the other cylinder arranged in the axial direction of the crankshaft 25, and the variable mechanism 70 is provided for each of the one cylinder and the other cylinder. . That is, two variable mechanisms 70 are arranged side by side in the axial direction of the cam shaft 52. Since the two variable mechanisms 70 are configured in the same manner, the single variable mechanism 70 will be described in detail here.

Rocker arms 53 are also provided for one cylinder and the other cylinder, respectively, and two rocker arms 53 and 53 are arranged side by side in the axial direction of the cam shaft 52.
Further, a pair of intake ports 43 of the cylinder head 36 are provided side by side in the axial direction of the cam shaft 52 for each cylinder. Two intake valves 45 are provided for each cylinder so as to open and close the openings 43a, 43a of the intake ports 43, 43.

FIG. 5 is a perspective view of the front cylinder portion 27 as viewed from above with the cylinder head cover 37 removed. Here, in FIG. 5, the valve device 51 on the exhaust side is not shown except for the cam shaft 52.
A plurality of cam shaft support portions 55 that rotatably support the cam shaft 52 are provided on the upper portion of the cylinder head 36. Three camshaft support portions 55 are provided along the axial direction of the camshaft 52 on the intake side. Three camshaft support portions 55 are provided along the axial direction of the camshaft 52 on the exhaust side.
Each camshaft support portion 55 includes a head-side support body 55a formed integrally with the cylinder head 36, and a cap 55b attached to the upper surface of the head-side support body 55a. The cam shaft 52 is supported by being fitted into a circular support hole formed by combining the head-side support body 55a and the cap 55b.

  The camshaft 52 is connected to the crankshaft 25 (FIG. 1) via a driving force transmission member (not shown), and rotates in conjunction (synchronization) with the rotation of the crankshaft 25. The driving force transmission member is, for example, a cam chain (not shown) that connects a driving sprocket (not shown) provided on the crankshaft 25 and a driven sprocket (not shown) provided on the camshaft 52.

As shown in FIGS. 3 and 4, the cam shaft 52 includes, in order from one end thereof, a sprocket fixing portion 56, a shaft portion 57a supported by the cam shaft support portion 55 on one end side, and an intake cam 58 (drive cam). ), A flange portion 59, a shaft portion 57b supported by the cam shaft support portion 55 at the axial intermediate portion, an intake cam 58, a flange portion 59, and a cam shaft support portion 55 at the other end side. The shaft portion 57c is provided.
The driven sprocket is fixed to the sprocket fixing portion 56 of the camshaft 52.
The shaft portion 57a is formed with a hook-shaped positioning portion 60 for positioning the cam shaft 52 in the axial direction by fitting into the groove on the inner periphery of the support hole portion of the cam shaft support portion 55.

As shown in FIG. 5, the drive mechanism 54 includes a ball screw 61, an actuator (not shown) that drives the ball screw 61, and a connection member 62 (FIG. 3) that connects the ball screw 61 and the variable mechanism 70. Prepare.
The ball screw 61 includes a screw shaft 61a extending in a direction orthogonal to the cam shaft 52, and a nut 61b provided on the screw shaft 61a. The nut 61 b is connected to the variable mechanism 70 via the connection member 62. The screw shaft 61 a is provided on the upper part of the cylinder head 36.
The actuator is an electric actuator such as a motor, and is connected to a control unit (not shown) of the motorcycle 1. When the actuator is driven by the command from the controller and the screw shaft 61a rotates, the nut 61b moves on the screw shaft 61a, and the position of the variable mechanism 70 is changed.

6 is a sectional view taken along line VI-VI in FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. In FIG. 7, a later-described valve operating cam return spring 76 is not shown.
3, 4, 6, and 7, the rocker arm 53 includes an arm support shaft 63 that is supported on the upper portion of the cylinder head 36, and an arm 64 that can swing around the arm support shaft 63. A pair of valve pressing portions 65, 65 provided at the tip of the arm 64 and a rocker roller 66 are provided.
The rocker roller 66 is rotatably provided via a roller shaft 66 a provided on the arm 64. The rocker roller 66 is disposed between the valve pressing portions 65 and 65 and the arm support shaft 63.
A pair of valve pressing portions 65, 65 are provided side by side in the axial direction of the cam shaft 52, and press the intake valves 45, 45. That is, the two intake valves 45 and 45 are simultaneously driven by one rocker arm 53.

3 to 7, the variable mechanism 70 includes a holder member 71 that can swing around the cam shaft 52 around the cam shaft 52, and a camshaft 52 that can rotate relative to the cam shaft 52. A valve cam 72 provided, and a link mechanism 73 that connects the holder member 71 and the valve cam 72 are provided.
The variable mechanism 70 includes a support shaft 74 that pivotally supports the link mechanism 73 on the holder member 71, a return spring 75 that biases the link mechanism 73, and a valve drive cam return spring 76 that biases the valve cam 72. Is provided.
Further, the link mechanism 73 includes a sub rocker arm 77 supported by the support shaft 74, and a link 78 connecting the sub rocker arm 77 and the valve cam 72.
The two variable mechanisms 70 and 70 are integrally connected by a variable mechanism connecting member 79 that connects the holder members 71 and 71 to each other.

8 is a sectional view taken along line VIII-VIII in FIG.
3 to 8, the holder member 71 includes a one-side holder 81 and an other-side holder 82 that are arranged side by side in the axial direction of the cam shaft 52. The one side holder 81 and the other side holder 82 are in direct contact with each other and are integrally coupled.
The one-side holder 81 includes a one-side plate portion 83 disposed so as to be orthogonal to the axial direction of the cam shaft 52 and a columnar extension extending from the upper end portion of the one-side plate portion 83 to the other-side holder 82 side. A protruding portion 84 is integrally provided.
The other-side holder 82 includes an other-side plate portion 85 arranged so as to be orthogonal to the axial direction of the cam shaft 52, and a columnar extension extending from the upper end portion of the other-side plate portion 85 to the one-side holder 81 side. A protruding portion 86 is integrally provided.
The extending portions 84 and 86 extend in the axial direction of the cam shaft 52, and the end surfaces 84a and 86a are in contact with each other and coupled.

The one-side holder 81 includes a plurality of screw hole portions 84b and 84b extending in the axial direction of the cam shaft 52 from the end surface 84a of the extending portion 84.
The other-side holder 82 includes a plurality of holes 86 b and 86 b that penetrate the extending portion 86 in the axial direction of the cam shaft 52.
The one-side holder 81 and the other-side holder 82 are inserted into the holes 86b, 86b of the extension portion 86 from the outside, and are fastened to the screw hole portions 84b, 84b of the extension portion 84, respectively. Are joined together.
Since the upper end portion of the holder member 71 is coupled via the extension portions 84 and 86, the space S formed between the one side plate portion 83 and the other side plate portion 85 is passed through the extension portions 84 and 86. Prepare below.

Circular cam shaft insertion holes 89 and 90 (FIG. 3) through which the cam shaft 52 is inserted are formed in the one side plate portion 83 and the other side plate portion 85, respectively.
The one-side holder 81 includes a cylindrical portion 91 that extends from the periphery of the cam shaft insertion hole 89 to the outside of the space S in the axial direction of the cam shaft 52.
The other-side holder 82 includes a cylindrical portion 92 that extends from the peripheral portion of the cam shaft insertion hole 90 to the outside of the space S in the axial direction of the cam shaft 52.
The cylindrical portions 91 and 92 are provided coaxially with the cam shaft 52.

As shown in FIGS. 5 and 8, the cam shaft support portions 55 and 55 of the cylinder head 36 include annular holder support portions 55 c and 55 c provided coaxially with the cam shaft 52.
The holder member 71 is disposed between the cam shaft support portions 55 and 55, and the cylindrical portions 91 and 92 are rotatably supported on the inner peripheral portions of the holder support portions 55c and 55c, thereby being supported by the cylinder head 36. The Thus, the holder member 71 can rotate around the cam shaft 52 around the axis 52a of the cam shaft 52.

The holder member 71 includes a support hole 93 that supports the support shaft 74. Specifically, the support hole 93 includes a one-side support hole 93 a provided in the one-side plate portion 83 and an other-side support hole 93 b provided in the other-side plate portion 85, and extends in parallel with the cam shaft 52. . The support hole 93 is disposed between the cam shaft insertion holes 89 and 90 and the extending portions 84 and 86 when the cam shaft 52 is viewed in the axial direction.
As shown in FIG. 8, the one-side support hole 93 a is a blind hole that opens to the space S side, and does not penetrate the one-side plate portion 83. The other side support hole 93 b penetrates the other side plate portion 85.

The one side plate portion 83 is formed with an insertion hole 83a substantially orthogonal to a one side support hole 93a extending in the axial direction of the cam shaft 52. The insertion hole 83a extends in the vertical direction and penetrates the one side plate portion 83, and penetrates the one side support hole 93a in the radial direction.
The support shaft 74 is a hollow cylindrical shaft. The support shaft 74 is provided with a spring locking hole 74a penetrating the support shaft 74 in the radial direction at a portion fitted to the one side support hole 93a.
The support shaft 74 is inserted into the one-side support hole 93 a so that the spring locking hole 74 a is continuous with the insertion hole 83 a of the one-side plate portion 83.

The one side holder 81 is provided with a cylindrical spring accommodating portion 94 (accommodating portion) in which the return spring 75 is accommodated. The spring storage portion 94 is formed integrally with the upper inner surface portion of the one side plate portion 83.
The spring storage portion 94 is provided with its axis line oriented in the vertical direction, and communicates the space S inside the holder member 71 above the holder member 71.
A part of the extension portion 84 of the one-side holder 81 extends toward the other-side holder 82 with the spring storage portion 94 as a base end portion.

The intake cam 58 of the cam shaft 52 is disposed in the axial direction of the cam shaft 52 between the one side plate portion 83 and the other side plate portion 85 of the holder member 71 in the vicinity of the other side plate portion 85, and On the inside.
As shown in FIG. 6, the intake cam 58 includes a base circular portion 58a that forms a substantially circular arc cam surface when viewed from the axial direction of the cam shaft 52, and a cam that protrudes radially outward from the base circular portion 58a. And a mountain portion 58b.

The valve cam 72 is formed in an annular shape that fits to the outer periphery of the cam shaft 52, and is rotatable relative to the cam shaft 52.
The valve cam 72 is located between the one side plate portion 83 and the other side plate portion 85 of the holder member 71 in the axial direction of the cam shaft 52, and is inside the space S. The valve cam 72 is disposed so as to be sandwiched between the intake cam 58 and the hook-shaped portion 59.
The valve cam 72 includes a base circular portion 72a that forms a substantially circular arc cam surface when viewed from the axial direction of the cam shaft 52, and a cam peak portion 72b that protrudes radially outward from the base circular portion 72a. .

The base circular portion 72 a and the cam crest portion 72 b of the valve cam 72 abut against the rocker roller 66 of the rocker arm 53 and press the rocker arm 53 in the valve opening direction of the intake valve 45 via the rocker roller 66. Specifically, in a state where the base circle portion 72 a of the valve cam 72 is in contact with the rocker roller 66, the intake valve 45 is closed and the cam peak portion 72 b of the valve cam 72 is in contact with the rocker roller 66. Then, the intake valve 45 is opened.
A spring coupling portion 72 c is formed on the side surface of the cam crest portion 72 b of the valve cam 72. The spring connecting portion 72 c is a hole extending in the axial direction of the cam shaft 52.

As shown in FIG. 6, the valve operating cam return spring 76 is a torsion coil spring whose coil portion 76 a is wound around the outer peripheral portion of the cam shaft 52. The valve drive cam return spring 76 is disposed between the valve drive cam 72 and the one side plate portion 83 in the axial direction of the cam shaft 52.
The valve cam return spring 76 biases the valve cam 72 so that the cam cam 72 rotates in a direction in which the cam crest 72 b is separated from the rocker roller 66 of the rocker arm 53. That is, the valve drive cam return spring 76 biases the valve drive cam 72 so that the intake valve 45 is closed.
The valve drive cam return spring 76 includes a valve drive cam connecting portion 76b (one end) extending in the axial direction of the cam shaft 52 at one end thereof. One end of the valve operating cam return spring 76 is connected to the valve operating cam 72 by inserting the valve operating cam connecting portion 76 b into the spring connecting portion 72 c of the valve operating cam 72.

The valve drive cam return spring 76 includes a holder connecting portion 76c (the other end) extending in the substantially radial direction of the coil portion 76a at the other end. The other end of the valve drive cam return spring 76 is supported on the holder member 71 side by inserting the holder connecting portion 76 c into the insertion hole 83 a of the one side plate portion 83 and the spring locking hole 74 a of the support shaft 74. The
In the present embodiment, the other end of the valve operating cam return spring 76 is supported on the holder member 71 side by inserting the holder connecting portion 76c into the insertion hole 83a and the spring locking hole 74a. For this reason, the shape of the holder member 71 for supporting the valve drive cam return spring 76 can be simplified. Further, the support shaft 74 can be prevented from rotating with respect to the holder member 71 with a simple structure by the holder connecting portion 76 c of the valve drive cam return spring 76.

9 is a cross-sectional view taken along the line IX-IX in FIG. FIG. 10 is a plan view of the sub rocker arm 77.
3, 4, and 6 to 10, the sub rocker arm 77 is disposed between the one side plate portion 83 and the other side plate portion 85 in the axial direction of the cam shaft 52, and is in the space S. To position. Further, the sub rocker arm 77 is disposed between the cam shaft 52 and the extension portions 84 and 86 in the axial direction of the cam shaft 52, and is disposed substantially orthogonal to the cam shaft 52. It extends to straddle 52.

The sub-rocker arm 77 is formed in an arm shape extending so as to straddle the cam shaft 52, and includes a bearing portion 96 supported by the support shaft 74 at its base end portion. Moreover, the sub rocker arm 77 is provided with a link connecting portion 97 to which the link 78 is connected at the tip thereof.
Further, the sub rocker arm 77 includes a roller 98 with which the intake cam 58 abuts and a spring receiving portion 99 that receives a return spring 75.

The bearing portion 96 is formed in a cylindrical shape extending in the axial direction of the cam shaft 52, and the support shaft 74 is inserted into the circular inner peripheral portion of the bearing portion 96. The sub rocker arm 77 can swing around the support shaft 74. The sub rocker arm 77 is positioned in the axial direction when both axial end surfaces of the bearing portion 96 abut against the inner surface portions of the one-side holder 81 and the other-side holder 82.
The sub rocker arm 77 includes a linear portion 100 that extends linearly from the bearing portion 96 perpendicular to the cam shaft 52. The bearing portion 96 and the link connecting portion 97 are connected in a straight line by the straight portion 100.
The link connecting portion 97 includes a hole 97a extending in the axial direction of the cam shaft 52, and the link connecting shaft 101 is fitted into the hole 97a.

  The width H 1 of the bearing portion 96 of the sub rocker arm 77 is larger than the width H 2 of the link connecting portion 97. In the axial direction of the cam shaft 52, the width H2 is within the width H1. As described above, since the shift amount of the link connecting portion 97 with respect to the bearing portion 96 is small in the axial direction of the cam shaft 52, the amount of twist generated between the bearing portion 96 and the link connecting portion 97 when the sub rocker arm 77 is operated. Can be reduced.

  The spring receiving portion 99 is formed in a plate shape extending from the straight portion 100 in the axial direction of the cam shaft 52, and extends from the straight portion 100 to a position below the spring storage portion 94. The spring receiving portion 99 is provided on one side of the linear portion 100.

The roller 98 is disposed in the roller storage portion 102 that passes through the sub rocker arm 77 in the plate thickness direction. The roller storage portion 102 is provided with a roller support shaft 103 extending in the axial direction of the cam shaft 52, and the roller 98 is rotatably supported by the roller support shaft 103.
The roller 98 is disposed between the bearing portion 96 and the link connecting portion 97 in the longitudinal direction of the sub rocker arm 77.
The roller 98 is provided on the other side of the linear portion 100. That is, the roller 98 and the spring receiving portion 99 are arranged separately on both sides of the linear portion 100 in the axial direction of the cam shaft 52.

The sub rocker arm 77 includes a notch 104 that passes through the bearing portion 96 in the plate thickness direction of the sub rocker arm 77 at a position continuous with the roller storage portion 102. The notch portion 104 and the roller storage portion 102 are connected in the longitudinal direction of the sub rocker arm 77, and the roller storage portion 102 is opened to the outside on the base end side of the sub rocker arm 77 through the notch portion 104. doing. The width of the cutout portion 104 is larger than the width of the roller storage portion 102.
Thereby, a tool such as a grinding wheel for finishing the shape of the roller storage portion 102 can be inserted into the roller storage portion 102 from the cutout portion 104 and the roller storage portion 102 can be processed. For this reason, the roller accommodating part 102 can be processed easily with high precision.

The link 78 is connected to the sub rocker arm 77 via a link connecting shaft 101 inserted through one end of the link 78. The link 78 extends downward from the link connecting shaft 101 to the intake valve 45 side along the outer periphery of the valve operating cam 72, and the other end is connected to the valve operating cam 105 via the cam connecting shaft 105 inserted into the valve operating cam 72. 72.
The cam coupling shaft 105 is an axis extending in the axial direction of the cam shaft 52, and is disposed on the opposite side of the valve operating cam connecting portion 76b with the cam shaft 52 in between when viewed in the axial direction of FIG.

The return spring 75 is a coil spring. The return spring 75 is disposed on the opposite side of the roller 98 with the straight portion 100 of the sub rocker arm 77 interposed therebetween.
The return spring 75 is provided in a compressed state between the ring-shaped locking member 106 that engages with the inner peripheral portion of the spring accommodating portion 94 of the one-side holder 81 and the spring receiving portion 99 of the sub rocker arm 77. It is done. A spring seat 107 is interposed between one end of the return spring 75 and the spring receiving portion 99.
The return spring 75 presses the sub rocker arm 77 via the spring receiving portion 99 and causes the roller 98 to contact the intake cam 58.

Here, the operation of the valve gear 50 will be described.
When the cam shaft 52 is rotated in the counterclockwise direction P in FIG. 6, the sub rocker arm 77 is pushed up via the roller 98 by the cam peak portion 58 b of the intake cam 58 that rotates integrally with the cam shaft 52. Accordingly, the sub rocker arm 77 swings upward in FIG. 6 about the support shaft 74, and the valve cam 72 is centered on the cam shaft 52 via the link 78 in the clockwise direction Q in FIG. Rotate to. Thereby, after the base circle part 72a slides on the rocker roller 66, the cam cam part 72b slides on the rocker roller 66, and the rocker arm 53 is pushed down by the cam peak part 72b. The intake valve 45 is opened.

  When the camshaft 52 is further rotated after the intake valve 45 is opened and the base circular portion 58a of the intake cam 58 is in contact with the roller 98, the sub rocker arm 77 is pushed down by the return spring 75 and the valve cam 72 is rotated in the counterclockwise direction P by the valve drive cam return spring 76, and the base circular portion 72 a comes into contact with the rocker roller 66. As a result, the intake valve 45 is pushed up by the valve spring 45a (FIG. 2) and is closed.

The valve gear 50 is a variable valve gear capable of changing the opening / closing operation characteristics of the intake valve 45 by changing the swing position of the holder member 71 by the drive mechanism 54 (FIG. 5).
As shown in FIG. 5, the variable mechanism 70 is connected to the drive mechanism 54. In the variable mechanism 70, the holder member 71 rotates around the cam shaft 52 when the ball screw 61 of the drive mechanism 54 is driven.

  For example, when the holder member 71 is rotated in the clockwise direction Q from the state of FIG. 6 by the drive mechanism 54, the support shaft 74 of the sub rocker arm 77 moves together with the holder member 71. Accordingly, the roller 98 of the sub rocker arm 77 moves in the clockwise direction Q, and the valve cam 72 rotates in the clockwise direction Q via the link 78. In this state, the cam crest portion 72b of the intake cam 58 that rotates in the counterclockwise direction P contacts the roller 98 at an earlier timing than in the state of FIG. Becomes faster. Further, in this state, the cam crest portion 72b of the intake cam 58 comes into contact with the rocker roller 66 up to a higher position of the cam crest than in the state of FIG. Increased lift.

Thus, in the valve operating apparatus 50, the swing position of the holder member 71 is changed, and the initial positions of the roller 98 and the valve cam 72 are changed, so that the opening / closing operating characteristics of the intake valve 45 are changed. Timing and lift amount can be controlled.
Here, the initial positions of the roller 98 and the valve cam 72 are the positions of the roller 98 and the valve cam 72 when the roller 98 of the sub rocker arm 77 is in contact with the base circle 58a of the intake cam 58. .

Next, the lubricating structure of the variable mechanism 70 will be described.
With reference to FIGS. 4 to 8, an oil receiving portion 110 whose upper surface is recessed downward is formed on the upper surface of the one-side holder 81. The oil receiving portion 110 is formed in a groove shape extending in the axial direction of the cam shaft 52 and is formed across the upper surfaces of the one side plate portion 83 and the extending portion 84. The oil receiving part 110 is at a position lower than the spring accommodating part 94. The oil receiving part 110 is inclined so as to descend toward the outer surface side of the one side plate part 83.

The one-side holder 81 includes an oil passage 111 that allows the oil receiving portion 110 to communicate with the one-side support hole 93a. The oil passage 111 is a hole penetrating from the bottom of the oil receiving portion 110 to the one side support hole 93a.
The oil passage 111 communicates with the hollow portion 74b of the support shaft 74 through the one side support hole 93a. The support shaft 74 includes a plurality of oil holes 74c that penetrate the support shaft 74 in the radial direction. The oil hole 74 c is formed in a portion located inside the bearing portion 96 of the sub rocker arm 77, and allows the hollow portion 74 b to communicate with the bearing portion 96.

Oil is supplied to the upper portion of the cylinder head 36 by a lubrication mechanism (not shown) of the engine 11. Part of the oil droplets supplied to the cylinder head 36 adheres to the variable mechanism 70 by, for example, dropping from the inner surface of the cylinder head cover 37.
Part of the oil adhering to the variable mechanism 70 is collected in the oil receiving part 110, flows through the oil passage 111 to the hollow part 74b of the support shaft 74, and passes from the oil hole 74c to the bearing part 96 of the sub rocker arm 77. Refueled.

  One side holder 81 including the spring storage portion 94 is formed to be larger in the axial direction of the cam shaft 52 than the other side holder 82. In the present embodiment, since the oil receiving part 110 and the oil path 111 are formed in the one side holder 81 having a size larger than that of the other side holder 82, the degree of freedom in layout of the oil receiving part 110 and the oil path 111 is high. The oil receiving part 110 and the oil path 111 can be enlarged.

Next, the adjustment structure of the initial position of the swing position of the variable mechanism 70 will be described.
As shown in FIGS. 3, 4, and 6, the other side holder 82 includes a position adjusting protrusion 115 that extends from the other side plate portion 85 to the radially outer side of the cam shaft 52.
The position adjusting protrusion 115 extends from the link 78 side portion toward the exhaust side valve gear 51 (FIG. 2) at the edge of the other side plate portion 85.

The position adjustment protrusion 115 includes a flat portion 115a on the upper surface of the tip.
As shown in FIG. 6, the cylinder head 36 includes an extending portion 116 that extends to above the position adjusting protrusion 115, and an adjusting tool 117 that is supported by the extending portion 116.
The adjustment tool 117 includes a pin member 118 that fits into a hole 116 a that vertically penetrates the extension portion 116, and a nut 119 that is screwed into the screw portion 118 a on the top of the pin member 118.
The pin member 118 is fixed to the extending portion 116 by fastening with a nut 119. The pin member 118 protrudes downward from the lower surface of the extending portion 116 and abuts on the flat portion 115a of the position adjusting protrusion 115 from above.

The downward protrusion amount of the pin member 118 can be adjusted by the fixing position by the nut 119.
When the variable mechanism 70 is assembled to the cylinder head 36, the swinging position of the holder member 71 can be regulated by abutting the flat portion 115 a of the position adjusting protrusion 115 against the lower surface of the pin member 118. In this case, the swinging position of the holder member 71 can be adjusted to an arbitrary position by setting the amount of downward protrusion of the pin member 118 to an arbitrary size.
For this reason, even if each component of the valve operating apparatus 50 has a dimensional variation, the swinging position of the holder member 71 can be adjusted to an appropriate position by the adjusting tool 117, and the variable mechanism 70 can be operated satisfactorily. Can do.

Next, a structure for connecting adjacent variable mechanisms 70 and 70 to each other will be described.
As shown in FIG. 3, the variable mechanisms 70, 70 provided respectively in one cylinder and the other cylinder arranged in the axial direction of the crankshaft 25 (FIG. 1) are variable mechanism connecting members that connect the holder members 71, 71 together. 79 are connected together.
The variable mechanisms 70 and 70 are connected to the drive mechanism 54 (FIG. 5) via a connection member 62 connected to one of the variable mechanisms 70, and when the drive mechanism 54 is driven, the variable mechanisms 70 and 70 are integrated. And the swing positions of the two variable mechanisms 70 and 70 are simultaneously changed.

The one side plate portion 83 includes a connection portion 120 to which the connection member 62 is connected in the vicinity of the spring storage portion 94. Specifically, the connection member 62 is connected to the connection portion 120 of the one-side plate portion 83 of the variable mechanism 70 located on the shaft portion 57 c side of the two variable mechanisms 70 and 70.
In the present embodiment, a plurality of variable mechanisms 70, 70 are connected to each other by a variable mechanism connecting member 79, and the swinging positions of the plurality of variable mechanisms 70, 70 are adjusted by a drive mechanism 54 connected to one variable mechanism 70. Since it can change simultaneously, the structure of the valve operating apparatus 50 can be simplified.

The variable mechanism connecting member 79 is connected to the first connecting portion 121 connected to one of the variable mechanisms 70, 70 and the second connected to the other variable mechanism 70 of the variable mechanisms 70, 70. The connecting portion 122 is integrally provided.
The first connecting portion 121 is formed in a block shape along the outer surface of the other side plate portion 85, and includes a pair of first fixing holes 121 a and 121 a that pass through the block-shaped portion in the axial direction of the cam shaft 52. . Bolts 121b and 121b for fixing the first connecting portion 121 to one variable mechanism 70 are inserted into the first fixing holes 121a and 121a.

The second connecting portion 122 is formed in a columnar shape that extends in the axial direction of the camshaft 52 from a portion between the pair of first fixing holes 121 a and 121 a in the first connecting portion 121. The second connecting portion 122 includes a second fixing hole 122 a that extends in the axial direction of the cam shaft 52. The second fixing hole 122a is a screw hole.
A bolt 122b for fixing the second connecting portion 122 to the other variable mechanism 70 is screwed into the second fixing hole 122a.

FIG. 11 is a view of the variable mechanisms 70 in FIG. 3 as viewed in the axial direction of the cam shaft 52 from the sprocket fixing portion 56 side.
As shown in FIGS. 3 and 11, the other side plate portion 85 of the other side holder 82 includes holder side fixing hole portions 85 a and 85 a into which bolts 121 b and 121 b are screwed.
The one side plate portion 83 of the one side holder 81 includes a bolt insertion hole portion 83b through which the bolt 122b is inserted. The bolt insertion hole 83 b is formed in a long hole shape that is long in the swinging direction of the holder member 71.

The variable mechanism connecting member 79 is disposed between one variable mechanism 70 and the other variable mechanism 70.
Specifically, in the variable mechanism connecting member 79, the first connecting portion 121 is fixed to the holder side fixing hole portions 85a and 85a of one variable mechanism 70 by bolts 121b and 121b.
Further, the one side plate portion 83 of the other variable mechanism 70 is fixed to the second connecting portion 122 of the variable mechanism connecting member 79 by a bolt 122b inserted through the bolt insertion hole portion 83b.

  In the present embodiment, since the bolt insertion hole 83b has a long hole shape, the bolt insertion hole 83b can be moved relative to the swing direction of the holder member 71 with respect to the bolt 122b. As a result, the other variable mechanism 70 can move relative to the one variable mechanism 70 in the swing direction of the variable mechanism 70 within the range of the size of the elongated hole of the bolt insertion hole 83b. For this reason, when the variable mechanisms 70 and 70 are assembled, the relative position between one variable mechanism 70 and the other variable mechanism 70 can be adjusted to an appropriate position according to the variation in the dimensions of the components. Thereafter, the variable mechanisms 70 and 70 are integrated by tightening the bolt 122b, and the relative position is fixed.

As described above, according to the embodiment to which the present invention is applied, the valve gear 50 of the engine 11 includes the cam shaft 52 that rotates in synchronization with the rotation of the engine 11 and the intake air that rotates integrally with the cam shaft 52. The cam 58, a valve cam 72 that rotates relative to the cam shaft 52 to open and close the intake valve 45, a link mechanism 73 that transmits the valve driving force of the intake cam 58 to the valve cam 72, and a support for the link mechanism 73 A holder member 71 that supports the shaft 74 and can swing around the cam shaft 52 is provided, and the operating characteristics of opening and closing of the intake valve 45 are changed when the holder member 71 swings. The holder member 71 includes a one-side holder 81 and an other-side holder 82 that are in contact with each other, and the support shaft 74 of the link mechanism 73 is inserted and supported by the one-side holder 81 and the other-side holder 82. The link mechanism 73 is disposed between the one side holder 81 and the other side holder 82.
Accordingly, the holder member 71 can be configured with a small number of parts, and the link mechanism 73 can be compactly disposed between the one-side holder 81 and the other-side holder 82. Further, since the support shaft 74 is inserted into the one side holder 81 and the other side holder 82, the support shaft 74 can be formed in a simple shape and can be provided with high accuracy. Furthermore, since the one side holder 81 and the other side holder 82 are in contact with each other and coupled, the rigidity of the holder member 71 can be improved. Further, the rigidity of the holder member 71 can be improved by the support shaft 74.

  The link mechanism 73 includes a sub-rocker arm 77 coupled to the support shaft 74 and a link 78 connecting the sub-rocker arm 77 and the valve cam 72. The support shaft 74 is inserted into the sub-rocker arm 77. And a link connecting portion 97 provided with a link connecting shaft 101 for connecting the link 78 to the sub rocker arm 77. The link connecting portion 97 is provided within a width H1 of the bearing portion 96. . Thereby, since the link connection part 97 is provided in the width | variety H1 of the bearing part 96, the torsional moment between the bearing part 96 and the link connection part 97 can be made small, and the sub rocker arm 77 can reduce the link mechanism 73. It can be operated well.

  The sub rocker arm 77 is provided with a roller 98 that abuts against the intake cam 58, and a return spring 75 that urges the sub rocker arm 77 so that the roller 98 abuts against the intake cam 58. Includes a straight portion 100 that linearly connects the bearing portion 96 and the link connecting portion 97, the return spring 75 is disposed on one side of the straight portion 100, and the roller 98 is on the other side of the straight portion 100. Placed in the direction. Thereby, since the sub rocker arm 77 includes the straight portion 100, the torsional moment generated in the sub rocker arm 77 can be reduced. Further, the return spring 75 and the roller 98 can be separately arranged on both sides of the linear portion 100 to achieve compactness.

Further, the sub rocker arm 77 includes a roller storage portion 102 in which a roller 98 is stored within the width H1 of the bearing portion 96, and the roller storage portion 102 is opened outward from a notch portion 104 formed in the bearing portion 96. doing. As a result, a large width of the bearing portion 96 can be secured, and the roller storage portion 102 can be processed from the space of the notch portion 104, so that the roller storage portion 102 can be formed easily and with high accuracy.
In addition, a return spring 75 that biases the sub rocker arm 77 toward the intake cam 58 is provided, and a spring storage portion 94 that stores the return spring 75 is provided in the one-side holder 81. Thereby, the spring accommodating part 94 can be integrated into one of the one side holder 81 and the other side holder 82, and the structure of the holder member 71 can be simplified.

Moreover, since the concave oil receiving part 110 is formed in the holder provided with the storage part among the one side holder 81 and the other side holder 82, the size of the one side holder 81 provided with the spring storage part 94 is reduced. The oil receiving part 110 can be enlarged using this.
The one-side holder 81 provided with the spring storage portion 94 includes an oil passage 111 that allows the oil receiving portion 110 to communicate with the hollow portion 74b of the support shaft 74. The support shaft 74 connects the hollow portion 74b to the link mechanism 73. An oil hole 74c for communication is provided. Thereby, the oil collected in the oil receiving part 110 can be supplied to the link mechanism 73 with a simple structure via the oil path of the one side holder 81, the hollow part 74b of the support shaft 74, and the oil hole 74c.

  Further, the support shaft 74 includes a spring locking hole 74 a extending in the radial direction of the support shaft 74, and the holder member 71 includes an insertion hole 83 a that continues to the spring locking hole 74 a and biases the valve cam 72. A valve drive cam return spring 76 is provided, a valve drive cam connection 76b at one end of the valve drive cam return spring 76 is connected to the valve drive cam 72, and a holder connection 76c at the other end of the valve drive cam return spring 76 is The insertion hole 83a and the spring locking hole 74a are inserted. Thereby, the valve operating cam return spring 76 can be fixed with a simple structure in which the holder connecting portion 76c of the valve operating cam return spring 76 is inserted into the insertion hole 83a and the spring locking hole 74a. Further, the support shaft 74 can be prevented from rotating by the holder connecting portion 76 c of the valve operating cam return spring 76.

In addition, the said embodiment shows the one aspect | mode which applied this invention, Comprising: This invention is not limited to the said embodiment.
In the above embodiment, the holder member 71 has been described as including the one-side holder 81 and the other-side holder 82 in which the extension portion 84 and the extension portion 86 are in contact with each other. It is not limited to this. A configuration in which a dimension adjusting spacer or the like is interposed between the extension portion 84 and the extension portion 86 is also included in the configuration in which the extension portion 84 and the extension portion 86 are in contact with each other.

11 Engine (Internal combustion engine)
46 Exhaust valve (engine valve)
52 Cam shaft 58 Intake cam (drive cam)
72 Valve cam 73 Link mechanism 74 Support shaft 74a Spring locking hole 74b Hollow portion 74c Oil hole 75 Return spring 76 Valve cam return spring 76b Valve cam connection (one end)
76c Holder connection (other end)
77 Sub rocker arm 78 Link 81 One side holder (holder provided with storage)
82 Other side holder 83a Insertion hole 94 Spring accommodating portion 96 Bearing portion 97 Link connecting portion 98 Roller 100 Linear portion 101 Link connecting shaft 102 Roller accommodating portion 104 Notch portion 110 Oil receiving portion 111 Oil passage H1 width (width of bearing portion)

Claims (8)

A camshaft (52) that rotates in synchronization with the rotation of the internal combustion engine (11), a drive cam (58) that rotates integrally with the camshaft (52), and a camshaft (52) that rotates relative to the camshaft (52), A valve cam (72) for opening and closing the valve (45), a link mechanism (73) for transmitting the valve driving force of the drive cam (58) to the valve cam (72), and a link mechanism (73) And a holder member (71) that supports the support shaft (74) and can swing around the cam shaft (52). The holder member (71) swings to allow the engine valve (45) to move. In a valve operating apparatus for an internal combustion engine in which the operating characteristics of opening and closing are changed,
The holder member (71) includes a one side holder (81) and another side holder (82) that are in contact with each other and coupled,
The support shaft (74) of the link mechanism (73) is inserted and supported by the one side holder (81) and the other side holder (82),
The valve mechanism for an internal combustion engine, wherein the link mechanism (73) is disposed between the one side holder (81) and the other side holder (82). The link mechanism (73) includes a sub rocker arm (77) coupled to the support shaft (74), and a link (78) connecting the sub rocker arm (77) and the valve cam (72). With
The sub rocker arm (77) is provided with a bearing portion (96) through which the support shaft (74) is inserted, and a link connecting shaft (101) for connecting the link (78) to the sub rocker arm (77). A link connecting portion (97),
The valve operating apparatus for an internal combustion engine according to claim 1, wherein the link connecting portion (97) is provided within a width (H1) of the bearing portion (96). The sub rocker arm (77) is provided with a roller (98) that comes into contact with the drive cam (58), and the sub rocker arm (77) so that the roller (98) comes into contact with the drive cam (58). A return spring (75) for biasing
The sub-rocker arm (77) includes a straight portion (100) that linearly connects the bearing portion (96) and the link connecting portion (97), and the return spring (75) includes the straight portion (100). The valve operating apparatus for an internal combustion engine according to claim 2, wherein the roller (98) is disposed on a side on the other side of the linear portion (100). The sub rocker arm (77) includes a roller storage portion (102) in which the roller (98) is stored in the width (H1) of the bearing portion (96),
The valve operating apparatus for an internal combustion engine according to claim 3, wherein the roller storage portion (102) opens outward from a notch portion (104) formed in the bearing portion (96). A return spring (75) for urging the sub-rocker arm (77) toward the drive cam (58) is provided;
The internal combustion engine according to claim 1, wherein a storage portion (94) for storing the return spring (75) is provided in one of the one side holder (81) and the other side holder (82). Valve gear.   Of the one side holder (81) and the other side holder (82), a concave oil receiving portion (110) is formed in the holder (81) provided with the storage portion (94). The valve operating apparatus for an internal combustion engine according to claim 5.   The holder (81) provided with the storage portion (94) includes an oil passage (111) that allows the oil receiving portion (110) to communicate with the hollow portion (74b) of the support shaft (74). The valve operating apparatus for an internal combustion engine according to claim 6, wherein the shaft (74) includes an oil hole (74c) for communicating the hollow portion (74b) with the link mechanism. The support shaft (74) includes a spring locking hole (74a) extending in the radial direction of the support shaft (74), and the holder member (71) is an insertion hole continuous with the spring locking hole (74a). (83a)
A valve cam return spring (76) for biasing the valve cam (72) is provided;
One end (76b) of the valve cam return spring (76) is connected to the valve cam (72), and the other end (76c) of the valve cam return spring (76) is the insertion hole (83a). The valve operating device for an internal combustion engine according to claim 1, wherein the valve operating device is inserted into the spring locking hole (74a).

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