JP5346750B2 - Valve operating device for V-type internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a valve gear for a V-type internal combustion engine with a simple structure by reducing number of kinds of components. <P>SOLUTION: The valve gear 50 for the V-type engine 17 varies phase/lift quantity of intake and exhaust valves 147, 148. The valve gear 50 includes: a cam chain 84f transmitting rotation of a crankshaft 105 to an intake cam 80I or an exhaust cam 80E of a front bank 110A; a drive gear 81f transmitting rotation of the intake cam 80I or the exhaust cam 80E to which rotation is transmitted by the cam chain 84f to the intake cam 80I or the exhaust cam 80E of the same bank; a cam chain 84r transmitting rotation of the crankshaft 105 to an intake cam 80I or an exhaust cam 80E of a rear bank 110B; a drive gear 81r transmitting rotation of the intake cam 80I or the exhaust cam 80E to which rotation is transmitted by the cam chain 84r to the intake cam 80I or the exhaust cam 80E of the same bank. One and another intake cams 80I are disposed inside of a V bank 100. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a valve operating apparatus for a V-type internal combustion engine.

  Conventionally, in a valve operating apparatus for a V-type internal combustion engine, in one bank, one camshaft is driven by a chain connected to a crankshaft, and the other camshaft is driven by a gear between one camshaft. In the other bank, one camshaft is driven by the chain, and the other camshaft is driven by a chain provided between the camshaft. (For example, refer to Patent Document 1). Moreover, in patent document 1, the idler gear which absorbs the slack of the chain connected with the crankshaft is provided.

JP 2007-126966 A

However, in the conventional valve operating apparatus for the V-type internal combustion engine, a plurality of chains and gears are used to drive the camshafts of one and the other banks, and the one bank differs from the other bank. Since driving is performed by a driving method, the types of parts are increased and the structure is complicated.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to reduce the types of parts and to realize a valve operating device for a V-type internal combustion engine with a simple structure.

In order to achieve the above object, according to the present invention, the cylinder block (131A, 131B) is arranged in a V shape, and the phase and / or lift amount of the engine valve (147, 148) interlocked with the camshaft (151, 152) is set. In a valve operating apparatus for a V-type internal combustion engine having a variable valve operating mechanism that is variable, rotation of a crankshaft (105) that rotationally drives an intake cam (80I) or an exhaust cam (80E) of one bank (110A). the intake cam (80I) or transmission member for transmitting to the exhaust cam (80E) (84f) and, rotating the transmitted intake cam by transmitting member (84f) of one bank (110A) (80I) or the exhaust cam (80E) a gear for transmitting the rotation to the intake cam of the same bank (110A) (80I) or the exhaust cam (80E) (81f), absorption of the other bank (110B) Cam (80I) or the exhaust cam and the transmission member for transmitting the rotation of the crankshaft (105) for rotating the (80E) to said intake cam (80I) or the exhaust cam (80E) (84r), the other bank (110B) gears for transmitting the rotation of the rotation transmitting intake air cam by transmitting member (84r) of (80I) or the exhaust cam (80E) on the intake cam of the same bank (110B) (80I) or the exhaust cam (80E) and (81r) One and the other intake cams ( 80I, 80I ) are provided inside the V bank (100) , and the intake cam (80I) and the exhaust cam (80E) are fulcrums (51, 51) of the rocker arm (51, 51). 51A, 51A) and a swing cam (52, 52) for driving the engine valve (147, 148) by pressing an intermediate portion between the operating point (51B, 51B). Features with swinging the swing direction of the movement cam (52, 52) are identical, the fulcrum (51A, 51A) of the exhaust side and the intake side of the rocker arm (51, 51) that are respectively provided in the same direction And
According to this configuration, the rotation of the intake cam or the exhaust cam transmitted to the rotation of the crankshaft via the transmission member of one bank is transmitted to the intake cam or the exhaust cam of the same bank by the gear. Further, the rotation of the intake cam or the exhaust cam transmitted to the rotation of the crankshaft via the transmission member of the other bank is transmitted to the intake cam or the exhaust cam of the same bank by the gear. Thereby, each of one bank and the other bank drives the intake cam and the exhaust cam by the transmission member and the gear, and the same transmission member and gear can be used in the one bank and the other bank, Since parts can be shared, a valve operating device for a V-type internal combustion engine can be realized with a simple structure. Further, since one and the other intake cams are provided inside the V bank, it is possible to efficiently arrange the intake components inside the V bank. Further, since the rocking cam swings in the same direction when the rocker arm is pressed by the rocking cam to drive the intake valve and the exhaust valve, the same valve operating device can be used on the intake side and the exhaust side. Since the parts can be shared, the valve operating device can be realized with a simple structure.

The link mechanism (56I, 56E ) swings around the cam shaft (151, 152) having the intake cam (80I) or the exhaust cam (80E ) and supports the swing cam (52, 52). ) , And the phase and / or lift amount of the engine valve (147, 148) is variable by changing the swing position of the link mechanism (56I, 56E ) by the actuator (70) . The swinging direction of the link mechanism (56I, 56E) when changing the phase and / or lift amount of (147, 148) may be the same on the intake side and the exhaust side.
In this case, since the oscillating direction of the link mechanism when changing the phase and / or lift amount of the engine valve is the same, the same valve gear can be used on the intake side and the exhaust side, and parts are shared. Therefore, the valve operating device can be realized with a simple structure. In addition, since the swinging direction of the link mechanism is the same, the valve operating devices on the intake side and the exhaust side are interlocked by connecting the valve operating devices on the intake side and the exhaust side with a simple mechanism such as a link. Can simplify the structure. Furthermore, since the structure of the valve operating device is simplified, the degree of freedom in arranging the actuator is improved.

Further, the swinging direction of the swing cam (52, 52) is, when the leading edge of the swing cam (52, 52) is rotated from the outside toward the inside of the V bank (100), said engine valve ( 147, 148) , and the fulcrum (51A, 51A) of the rocker arm (51 , 51) may be disposed outward of the V bank (100) .
In this case, in one bank and the other bank, the engine valves located in the outward direction of the V bank in each bank are arranged at an angle closer to the center of each bank, and the sandwiching angle of the engine valve becomes small. A large space outside can be secured. For this reason, it is possible to secure a larger space for arranging auxiliary machines and the like outside the V bank.

Moreover, the swinging direction of the swing cam (52, 52) is, when the leading edge of the swing cam (52, 52) is rotated from the inside to the outside of the V bank (100), said engine valve The fulcrum (51A, 51A) of the rocker arm (51 , 51) may be disposed in the inner direction of the V bank (100) .
In this case, in one bank and the other bank, the engine valve located in the inner direction of the V bank in each bank is arranged at an angle closer to the center of each bank, and the sandwiching angle of the engine valve becomes smaller. A large space inside can be secured. For this reason, a larger space can be secured inside the V bank for the intake device, auxiliary equipment, and the like.

The combustion chamber (140) central to the spark plug (142) is provided, the spark plug (142), the said fulcrum of the rocker arm on the side close to the ignition plug (142) (51) (51A) The rocker arm (51) on the opposite side may be provided inclined toward the fulcrum (51A) side.
In this case, a distance can be secured between the fulcrum of the rocker arm adjacent to the spark plug and the spark plug, and there is no need to form a relief in the rocker arm close to the spark plug. The rocker arm can be shared to make the valve operating device simple. In addition, the arrangement of the engine valve with respect to the combustion chamber can be adjusted to bring the combustion chamber shape closer to an ideal shape.

In the valve operating apparatus for a V-type internal combustion engine according to the present invention, the same transmission member and gear can be used in one bank and the other bank, and parts can be shared, so that the valve operating apparatus is realized with a simple structure. it can.
Further, since the swing directions of the swing cams when driving the intake valve and the exhaust valve are the same, the same valve operating device can be used on the intake side and the exhaust side, and parts can be shared. The valve device can be realized with a simple structure.

  Further, since the swinging direction of the link mechanism is the same, the same valve operating device can be used on the intake side and the exhaust side, and parts can be shared, so that the valve operating device can be realized with a simple structure. In addition, since the swinging direction of the link mechanism is the same, the valve operating devices on the intake side and the exhaust side are interlocked by connecting the valve operating devices on the intake side and the exhaust side with a simple mechanism such as a link. Can simplify the structure. Furthermore, since the structure of the valve operating device is simplified, the degree of freedom in arranging the actuator is improved.

Furthermore, the engine valves located in the outer direction of the V bank are arranged at an angle closer to the center of each bank, and the sandwiching angle of the engine valve is reduced, so that a large space outside the V bank can be secured, and the V bank A larger space for arranging auxiliary equipment and the like can be secured outside.
Furthermore, the engine valve located in the inner direction of the V bank is arranged at an angle closer to the center of each bank, and the sandwiching angle of the engine valve is reduced, so that a large space inside the V bank can be secured, and the V bank It is possible to secure a larger space for arranging the intake device and the auxiliary machine inside.
In addition, the spark plug may be installed at an inclination, and it is possible to further secure the distance between the fulcrum of the rocker arm on the adjacent side and the spark plug, and to form a relief on the rocker arm on the side close to the spark plug. Therefore, the valve operating device can be made simple by sharing the rocker arm between the intake side and the exhaust side. In addition, the arrangement of the engine valve with respect to the combustion chamber can be adjusted to bring the combustion chamber shape closer to an ideal shape.

1 is a right side view of a motorcycle according to an embodiment of the present invention. It is the figure which looked at the internal structure of the engine from the side. It is a figure which expands and shows the internal structure of the front bank of FIG. It is a partially broken side view which shows a valve operating apparatus. It is the longitudinal cross-sectional view which looked at the valve operating apparatus of the front bank from the rear side. It is a perspective view which shows a valve operating apparatus. It is the longitudinal cross-sectional view which looked at the drive mechanism from the side surface side. It is the longitudinal cross-sectional view which looked at the drive mechanism from the front part side. It is a figure which shows the valve operation characteristic of an intake valve and an exhaust valve. It is a top view which shows the valve operating apparatus of a front bank and a back bank. It is a side view which shows the back bank in the modification of embodiment.

Preferred embodiments of the present invention will be described below with reference to the drawings. In the description, descriptions of directions such as front and rear, right and left and up and down are for the vehicle body.
FIG. 1 is a right side view showing a motorcycle to which a valve gear according to an embodiment of the present invention is applied. The motorcycle 10 includes a body frame 11, a pair of left and right front forks 13 rotatably supported by a head pipe 12 attached to a front end portion of the body frame 11, and a top that supports an upper end portion of the front fork 13. A steering handle 15 attached to the bridge 14, a front wheel 16 rotatably supported by the front fork 13, an engine 17 as a V-type internal combustion engine supported by the vehicle body frame 11, and an exhaust pipe 18A. , 18B, exhaust mufflers 19A, 19B connected to each other, a rear swing arm 21 swingably supported by a pivot 20 at the lower rear portion of the vehicle body frame 11, and a rear end portion of the rear swing arm 21. The rear wheel 22 is rotatably supported, and the rear wheel 22 is disposed between the rear swing arm 21 and the body frame 11. Cushion 23 is disposed.

  The vehicle body frame 11 includes a main frame 25 extending rearward and downward from the head pipe 12, a pair of left and right pivot plates (also referred to as a center frame) 26 connected to the rear portion of the main frame 25, and a downward extension from the head pipe 12. And a down tube 27 which is bent and extends and connected to the pivot plate 26. The fuel tank 28 is supported so as to straddle the main frame 25, the rear of the main frame 25 extends to the upper part of the rear wheel 22 and the rear fender 29 is supported, and the seat 30 is supported between the rear fender 29 and the fuel tank 28. . In FIG. 1, reference numeral 31 denotes a radiator supported by the down tube 27, reference numeral 32 denotes a front fender, reference numeral 33 denotes a side cover, reference numeral 34 denotes a headlight, reference numeral 35 denotes a taillight, and reference numeral 36 denotes an occupant step. .

  The engine 17 is supported in a space surrounded by the main frame 25, the pivot plate 26 and the down tube 27. The engine 17 is a front-rear V-type two-cylinder water-cooled four-cycle engine in which cylinders (cylinders) are banked back and forth in a V shape. The engine 17 is supported by the vehicle body frame 11 via a plurality of engine brackets 37 (only part of which is shown in FIG. 1) so that the crankshaft 105 is oriented in the horizontal direction with respect to the vehicle body. The power of the engine 17 is transmitted to the rear wheel 22 via a drive shaft (not shown) disposed on the left side of the rear wheel 22.

The engine 17 has a V bank 100 formed by arranging a front bank 110A (one bank) and a rear bank 110B (the other bank), each of which constitutes a cylinder, in a V shape in a side view. The sandwiching angle (also referred to as bank angle) between 110A and rear bank 110B is formed at an angle smaller than 90 degrees (for example, 52 degrees). The valve gears of the banks 110A and 110B are both configured in a 4-valve double overhead camshaft (DOHC) system.
A V-shaped V bank space K is formed inside the V bank 100 in a side view. In the V bank space K, an air cleaner 41 and a throttle body 42 constituting an engine intake system are disposed. The throttle body 42 supplies the air purified by the air cleaner 41 to the front bank 110A and the rear bank 110B. The banks 110A and 110B are connected to exhaust pipes 18A and 18B constituting an engine exhaust system. The exhaust pipes 18A and 18B pass through the right side of the vehicle body and exhaust mufflers 19A and 19B are connected to the rear ends thereof. Exhaust gas is discharged through the exhaust pipes 18A and 18B and the exhaust mufflers 19A and 19B.

2 is a view of the internal structure of the engine 17 as viewed from the side, and FIG. 3 is an enlarged view of the internal structure of the front bank 110A of FIG.
In FIG. 2, the front bank 110A shows the periphery of the piston, and the rear bank 110B shows the periphery of the cam chain. Further, as shown in FIG. 2, the front bank 110A and the rear bank 110B of the engine 17 have substantially the same structure, and the rear bank 110B is obtained by rotating the entire front bank 110A by 180 ° about the cylinder bore 135 as an axis. Is provided at the rear of the engine 17.
In FIG. 2, reference numeral 121 indicates an intermediate shaft (rear balancer shaft), reference numeral 123 indicates a main shaft, and reference numeral 125 indicates a counter shaft. The crankshaft 105 extends in parallel to the vehicle width direction, and the shafts 121, 123, and 125 including the crankshaft 105 are arranged in parallel to each other while being shifted in the longitudinal direction and the vertical direction of the vehicle body, and support the shafts. 110C includes a gear transmission mechanism that transmits the rotation of the crankshaft 105 in the order of the intermediate shaft 121, the main shaft 123, and the counter shaft 125.

  As shown in FIG. 2, the front cylinder block 131A and the rear cylinder block 131B are arranged on the upper surface of the crankcase 110C of the engine 17 so as to form a predetermined sandwich angle between the front and the rear of the vehicle body, and the upper surfaces of these cylinder blocks 131A and 131B. The front cylinder head 132A and the rear cylinder head 132B are coupled to each other, and the head covers 133A and 133B are mounted on the upper surfaces of the cylinder heads 132A and 132B, respectively, thereby forming the front bank 110A and the rear bank 110B.

Each cylinder block 131A, 131B is formed with a cylinder bore 135, and a piston 136 is slidably inserted into each cylinder bore 135. Each piston 136 is connected to the crankshaft 105 via a connecting rod 137.
Combustion recesses 141 constituting the top surface of the combustion chamber 140 formed above the piston 136 are formed on the lower surfaces of the cylinder heads 132A and 132B, and the spark plugs 142 face the tips of the combustion recesses 141. Arranged. The spark plug 142 includes a plug main body 142A disposed in the combustion recess 141, and a plug cap 142B attached to the upper portion of the plug main body 142A. The plug cap 142B formed in a cylindrical shape extends to the upper surface of the head cover 133A.

The engine 17 is an in-cylinder injection engine that directly injects fuel into the combustion chamber 140 from an injector 143 provided in each combustion recess 141. Each injector 143 is inserted into each cylinder head 132A, 132B from the V bank space K side, and is arranged with its tip facing each combustion recess 141. The injector 143 is attached in a state of being laid down with respect to the cylinder axis C.
A fuel pump 144 is provided above the cylinder head 132A, and fuel is supplied from the fuel pump 144 to each injector 143 through the fuel pipe 144A.

Each cylinder head 132A, 132B has an intake port 145 communicating with each combustion recess 141 by a pair of openings 145A arranged side by side in the vehicle width direction, and a pair of openings 146A arranged side by side in the vehicle width direction. Thus, an exhaust port 146 communicating with each combustion recess 141 is formed. The intake ports 145 of the front and rear banks 110A, 110B are arranged between the spark plug 142 and the injector 143 in the V bank space K. Further, the exhaust ports 146 (the rear bank side is not shown) of the front and rear banks 110A and 110B are respectively arranged on the front side of the front bank 110A and the rear side of the rear bank 110B with the spark plug 142 interposed therebetween.
2 and 3, each intake port 145 includes a lower intake port 145B provided integrally with the cylinder heads 132A, 132B, and an upper intake port 145C provided separately from the cylinder heads 132A, 132B. ing. The upper intake port 145C is attached to the lower intake port 145B at a different angle in a direction closer to the head covers 133A and 133B.

  The intake ports 145 merge in the intake chamber 43, and the intake chamber 43 is connected to the throttle body 42. The throttle body 42 employs TBW (throttle-by-wire) that changes the cross-sectional area of the throttle valve by driving an actuator. The exhaust port 146 of the cylinder head 132A is connected to the exhaust pipe 18A (see FIG. 1), and the exhaust port 146 of the cylinder head 132B is connected to the exhaust pipe 18B (see FIG. 1).

  The cylinder heads 132A and 132B include a pair of intake valves 147 (engine valves) that open and close the openings 145A of the intake ports 145 and a pair of exhaust valves 148 (engines) that open and close the openings 146A of the exhaust ports 146. Valve). The intake valve 147 and the exhaust valve 148 are urged by valve springs 149 and 149 in the direction of closing the ports. The intake valve 147 and the exhaust valve 148 are driven by a valve gear 50 capable of changing valve operating characteristics such as opening / closing timing and lift amount. The valve operating apparatus 50 includes an intake side valve operating apparatus 50I (variable valve operating mechanism) that operates the intake valve 147, and an exhaust side valve operating apparatus 50E (variable valve operating mechanism) that operates the exhaust valve 148. ing.

The intake side valve operating apparatus 50I includes an intake side camshaft 151 (camshaft) that rotates in conjunction with the rotation of the crankshaft 105, and an intake cam 80I that drives the intake valve 147, and the exhaust side valve operating apparatus 50E. Includes an exhaust camshaft 152 (camshaft) that rotates in conjunction with the rotation of the crankshaft 105 and an exhaust cam 80E that drives the exhaust valve 148.
In the front bank 110 </ b> A, the intake side valve operating device 50 </ b> I is disposed on the rear side of the spark plug 142, and the exhaust side valve operating device 50 </ b> E is disposed on the front side of the spark plug 142. On the other hand, in the rear bank 110B, the intake side valve operating device 50I is disposed on the front side of the spark plug 142, and the exhaust side valve operating device 50E is disposed on the rear side of the spark plug 142.

The intake side camshaft 151 and the exhaust side camshaft 152 are arranged in parallel with the crankshaft 105 and are rotatably supported by the cylinder heads 132A and 132B. The intake camshaft 151 includes an intake camshaft 151f provided in the front bank 110A and an intake camshaft 151r provided in the rear bank 110B. The exhaust camshaft 152 is an exhaust cam provided in the front bank 110A. A shaft 152f and an exhaust camshaft 152r provided in the rear bank 110B are provided.
As shown in FIG. 3, the intake camshafts 151f and 151r are formed with intake drive cams 153 that rotate integrally with the intake camshafts 151f and 151r. The intake drive cam 153 includes a base circle portion 155A that forms a circular cam surface, and a cam peak portion 155B that forms a cam surface that protrudes outward from the base circle portion 155A.
The exhaust camshafts 152f and 152r are formed with exhaust drive cams 154 that rotate integrally with the exhaust camshafts 152f and 152r. Similarly, the exhaust drive cam 154 has a base circle portion 155A and a cam peak portion 155B.

As shown in FIG. 2, gears are provided on one end side (the vehicle body right side) in the vehicle width direction of the intake camshaft 151r and the exhaust camshaft 152r arranged in the rear bank 110B. Specifically, a drive gear 81r (gear) that rotates in the same direction as the crankshaft 105 is fixed to one end of the intake camshaft 151r, and the exhaust camshaft 152r is driven in direct engagement with the drive gear 81r. The driven gear 82r is fixed. A transmission gear 83r driven by an endless cam chain 84r connected to the crankshaft 105 (the transmission member of the other bank) is fixed to one end side of the intake camshaft 151r. A drive sprocket 163 is fixed to one end of the crankshaft 105, and the rotation of the crankshaft 105 is transmitted by a cam chain 84r wound between the drive sprocket 163 and the transmission gear 83r. The cam chain 84r is accommodated in a cam chain chamber 166r formed on the side surface on one end side of the rear bank 110B. The tensioner 90 for adjusting the tension of the cam chain 84r is disposed so as to contact the rear side of the cam chain 84r, and extends from the vicinity of the drive sprocket 163 to the upper part of the cylinder head 132B.
Here, the drive gear 81r and the driven gear 82r are the same parts formed in the same shape. For this reason, the intake camshaft 151r and the exhaust camshaft 152r rotate in opposite directions at the same rotational speed.

  In the engine 17, the crankshaft 105 is rotated in the clockwise direction (the direction of the arrow X) in the figure as shown in FIG. That is, in the rear bank 110B, when the crankshaft 105 rotates, the intake camshaft 151r is rotated in the clockwise direction in the same direction as the crankshaft 105 via the transmission gear 83r by the cam chain 84r. On the other hand, the exhaust camshaft 152r is driven by a drive gear 81r that rotates integrally with the intake camshaft 151r, and is rotated in the counterclockwise direction (direction of arrow Y) opposite to the intake camshaft 151r.

Further, as shown in FIG. 2, gears are respectively provided on the other end side (the left side of the vehicle body) in the vehicle width direction of the intake camshaft 151f and the exhaust camshaft 152f disposed in the front bank 110A. Specifically, a drive gear 81f (gear) is fixed to the other end of the exhaust camshaft 152f, and a driven gear 82f that is directly engaged with the drive gear 81f and driven is fixed to the other end of the intake camshaft 151f. ing. A transmission gear 83f is fixed to the other end of the exhaust camshaft 152f. A drive sprocket 163 is fixed to the other end of the crankshaft 105, and the rotation of the crankshaft 105 is caused by an endless cam chain 84f (one bank) wound between the drive sprocket 163 and the transmission gear 83f. Transmission member). The cam chain 84f is accommodated in a cam chain chamber 166f (see FIG. 10) formed on the side surface on the other end side of the front bank 110A.
Here, also in the front bank 110A, the drive gear 81f and the driven gear 82f are the same parts formed in the same shape. Further, the drive gears 81f and 81r, the driven gears 82f and 82r, the transmission gears 83f and 83r, the cam chains 84f and 84r, and the drive sprocket 163 use the same parts of the same shape in the front bank 110A and the rear bank 110B. ing.

  In the front bank 110A, when the crankshaft 105 rotates in the clockwise direction (the direction of the arrow X), the exhaust camshaft 152f rotates in the clockwise direction in the same direction as the crankshaft 105 through the transmission gear 83f by the cam chain 84f. Be made. On the other hand, the intake camshaft 151f is driven by a drive gear 81f that rotates integrally with the exhaust camshaft 152f, and is rotated in the counterclockwise direction (the direction of arrow Y) opposite to the exhaust camshaft 152f.

In the front bank 110A and the rear bank 110B, the reduction ratio from the drive sprocket 163 to the transmission gears 83f and 83r is set to 2, and the intake camshafts 151f and 151r and the exhaust camshafts 152f and 152r are half of the crankshaft 105. It is rotated at a rotation speed of. The intake valve 147 and the exhaust valve 148 are driven according to the cam profiles of the intake drive cam 153 and the exhaust drive cam 154 provided on the intake cam shafts 151f and 151r and the exhaust cam shafts 152f and 152r, and the intake port 145 and the exhaust port 146 are driven. Are opened and closed.
Further, in the front bank 110A and the rear bank 110B, the drive gears 81f and 81r and the driven gears 82f and 82r are engaged with each other at positions overlapping the cylinder axis C. As described above, the gear train composed of the drive gears 81f and 81r and the driven gears 82f and 82r is arranged at the front and rear centers in each of the front bank 110A and the rear bank 110B, and therefore the drive gears 81f and 81r and the driven gears 82f and 82r. The front bank 110A and the rear bank 110B can be downsized in the front-rear direction.

  A generator (not shown) is provided at the other end of the crankshaft 105, and a drive gear (hereinafter referred to as a crank-side drive gear) 175 is fixed to one end of the crankshaft 105 inside the drive sprocket 163 at one end. Is done. The crank side drive gear 175 meshes with a driven gear (hereinafter referred to as an intermediate side driven gear) 177 provided on the intermediate shaft 121, and transmits the rotation of the crankshaft 105 to the intermediate shaft 121 at a constant speed. The intermediate shaft 121 is rotated at the same speed and in the opposite direction.

The intermediate shaft 121 is rotatably supported below the rear side of the crankshaft 105 and below the front side of the main shaft 123.
An oil pump drive sprocket 181, the intermediate driven gear 177, and a drive gear (hereinafter referred to as an intermediate drive gear) 182 having a smaller diameter than the driven gear 177 are attached to the right end portion of the intermediate shaft 121 in order. ing.
The oil pump drive sprocket 181 is located behind the intermediate shaft 121 and is connected to the driven sprocket 186 fixed to the drive shaft 185 of the oil pump 184 disposed below the main shaft 123 via the transmission chain 187. The rotational force of 121 is transmitted and the oil pump 184 is driven.

  Further, the intermediate drive gear 182 meshes with a driven gear (hereinafter referred to as a main driven gear) 191 that is relatively rotatable with the main shaft 123 to reduce the rotation of the intermediate shaft 121 and thereby a clutch mechanism (not shown). Is transmitted to the main shaft 123. That is, the reduction ratio from the crankshaft 105 to the main shaft 123, that is, the primary reduction ratio of the engine 17 is set by the reduction ratio of the intermediate drive gear 182 and the main driven gear 191.

The main shaft 123 is rotatably supported on the rear upper side of the crankshaft 105, and a counter shaft 125 is rotatably supported substantially behind the main shaft 123. A transmission gear group (not shown) is disposed across the main shaft 123 and the counter shaft 125, and these constitute a transmission.
The left end portion of the counter shaft 125 is connected to a drive shaft (not shown) extending in the front-rear direction of the vehicle body. Thereby, the rotation of the counter shaft 125 is transmitted to the drive shaft.

FIG. 4 is a partially cutaway side view showing the valve gear 50, and FIG. 5 is a longitudinal sectional view of the valve gear 50 of the front bank 110A as seen from the rear side. FIG. 6 is a perspective view showing the valve gear 50.
As shown in FIG. 3, the valve gear 50 is arranged in a state in which the intake side valve gear 50I and the exhaust side valve gear 50E, which are configured substantially the same, face the same direction with the ignition plug 142 interposed therebetween. Has been. Further, the valve gears 50 of the front bank 110A and the rear bank 110B have substantially the same structure. For this reason, in the present embodiment, a detailed description of the valve operating device 50 of the rear bank 110B and the exhaust side valve operating device 50E of the front bank 110A is omitted, and mainly the intake side valve operating device 50I of the front bank 110A. explain.

  As shown in FIGS. 4 to 6, the intake side valve operating apparatus 50I includes an intake camshaft 151f, an intake drive cam 153 that rotates integrally with the intake camshaft 151f, a rocker arm 51 that opens and closes the intake valve 147, and an intake cam. A valve cam 52 (oscillation cam) that is supported by the shaft 151f so as to be relatively rotatable and opens and closes the intake valve 147 via the rocker arm 51, a holder 53 that can swing around the intake camshaft 151f, and a holder 53 A link mechanism 56I that is supported so as to be swingable, transmits the valve drive force of the intake drive cam 153 to the valve drive cam 52, and swings the valve drive cam 52 is provided. The link mechanism 56I includes a sub rocker arm 54 connected to the holder 53, and a connect link 55 that connects the sub rocker arm 54 and the valve cam 52 so as to be swingable. The intake cam 80I includes an intake drive cam 153, a link mechanism 56I, and a valve cam 52. Further, the valve gear 50 includes a drive mechanism 60 that swings the holder 53.

  Further, the exhaust side valve operating device 50E is supported by the exhaust camshaft 152f, the exhaust drive cam 154 that rotates integrally with the exhaust camshaft 152f, the rocker arm 51 that opens and closes the exhaust valve 148, and the exhaust camshaft 152f so as to be relatively rotatable. The valve cam 52 opens and closes the exhaust valve 148 via the rocker arm 51, the holder 53 swings around the exhaust cam shaft 152f, and is swingably supported by the holder 53. The valve of the exhaust drive cam 154 A link mechanism 56E that transmits the driving force to the valve cam 52 and swings the valve cam 52 is provided. The exhaust cam 80E includes an exhaust drive cam 154, a link mechanism 56E, and a valve cam 52.

  The rocker arm 51 is formed to be wide in the vehicle width direction across the ignition plug 142, and the pair of intake valves 147 (exhaust valves 148 on the exhaust side) are opened and closed by one rocker arm 51. As shown in FIGS. 3 and 4, the rocker arm 51 includes a rocker arm pivot 51A (fulcrum) that is pivotally supported by the cylinder head 132A, an action part 51B (action point) that presses the intake valve 147, and a rocker arm. There is a pressed portion 51C that is provided at an intermediate portion between the pivot 51A and the action portion 51B and is pressed by the valve cam 52. Specifically, the rocker arm pivot 51A is provided at one end of the rocker arm 51, and the action part 51B formed at the other end has a screw-type adjusting part 51D that abuts on the upper end part of the intake valve 147, and the pressed part 51C. Has a rotatable roller 51E that contacts the valve cam 52.

In the front bank 110A, the rocker arm 51 on the intake side is disposed in a state where the rocker arm pivot 51A is close to the rear portion of the spark plug 142, and the intake valve 147 is located on the inner side (inward direction) of the V bank 100 than the rocker arm pivot 51A. Extends from the action portion 51B located at the combustion recess 141 to the combustion recess 141. The exhaust-side rocker arm 51 is disposed with the rocker arm pivot 51A positioned on the outer side (outward direction) of the V bank 100, and the exhaust valve 148 is disposed close to the front portion of the spark plug 142. The working portion 51B extends to the combustion recess 141. That is, in the front bank 110A, the rocker arm pivots 51A on the intake side and the exhaust side are disposed on the outer side of the V bank 100 with respect to the corresponding action portions 51B.
As shown in FIG. 2, in the rear bank 110B as well, the rocker arm pivots 51A on the intake side and the exhaust side are arranged on the outer side of the V bank 100 with respect to the corresponding action portions 51B.

For this reason, in the front bank 110A and the rear bank 110B, the exhaust valves 148 arranged on the outer side of the V bank 100 are arranged along the spark plug 142 on the center side of the front bank 110A and the rear bank 110B. It can be arranged at an angle closer to the vertical direction. As a result, the angle between the intake valve 147 and the exhaust valve 148 in the front bank 110A and the rear bank 110B is reduced, so that a large space on the outer side of the V bank 100 can be secured.
Further, the rocker arms 51 on the intake side and the exhaust side are arranged in a state where the rocker arm pivots 51A are located on the outer side of the V bank 100, and the rocker arms 51 are arranged in the same direction. The swing directions of the valve cams 52 when the intake valve 147 and the exhaust valve 148 are opened can be made the same, and the valve cams 52 on the intake side and the exhaust side can be arranged in the same direction.

  As shown in FIG. 3, the spark plug 142 is disposed on the side of the action portion 51B of the rocker arm 51 on the exhaust side so as to be inclined at an angle G with respect to the cylinder axis C, and the lower end facing the combustion chamber 140 is the cylinder axis C The upper part including the plug body 142A is inclined to the front side of the rocker arm 51 with respect to the cylinder axis C. Therefore, a space can be secured between the rocker arm pivot 51A of the rocker arm 51 on the intake side and the rear portion of the spark plug 142, and it is not necessary to form a relief portion for the spark plug 142 on the rocker arm pivot 51A. The rocker arm 51 can be a common part on the side.

As shown in FIGS. 5 and 6, the intake camshaft 151 has a gear fixing portion 151A to which a driven gear 82f, a drive gear 81r, and a transmission gear 83r (see FIG. 2) are fixed at the end in the vehicle width direction. doing. Here, the driven gear 82f is fixed to the intake camshaft 151f of the front bank 110A, but the drive gear 81r and the transmission gear 83r are fixed to the gear fixing portion (not shown) of the camshaft 151r of the rear bank 110B. Is done.
The intake-side camshaft 151 supports a positioning portion 151B, an intake drive cam 153, and a valve-operating cam 52 that protrude from the outer periphery of the intake-side camshaft 151 and have a circular cross section in order from the gear fixing portion 151A side. The valve operating cam support 151C and the collar fitting portion 151D having a smaller diameter than the valve operating cam support 151C are formed. A camshaft collar 155 that functions as a bearing for the intake side camshaft 151 is fitted to the collar fitting portion 151D, and the camshaft collar 155 is valve-operated by a fixing bolt 156 that is fastened to the end of the intake side camshaft 151. It is pressed against the cam 52 side.

Both ends of the intake camshaft 151 are rotatably supported by camshaft support portions 201 and 202, respectively. Specifically, the camshaft support portions 201 and 202 are configured by fixing caps 201B and 202B each having a semicircular cross-sectional support portion to head side support portions 201A and 202A formed on the upper portion of the cylinder head 132A. Has been. A groove 201C formed in accordance with the shape of the positioning portion 151B is formed in the camshaft support portion 201 provided on the positioning portion 151B side, and the position of the positioning portion 151B is restricted by the groove 201C. The side camshaft 151 is positioned in the axial direction.
Further, holder support portions 201D and 202D for supporting the holder 53 are provided on the surface of the camshaft support portions 201 and 202 on the side of the intake drive cam 153, respectively.

The valve cam 52 is pivotally supported by a valve cam support portion 151 </ b> C provided at an intermediate portion of the intake side camshaft 151. As shown in FIG. 4, the valve cam 52 includes a base circle 52A for maintaining the intake valve 147 (exhaust valve 148 on the exhaust side) in a closed state and an intake valve 147 (exhaust valve 148 on the exhaust side). A cam crest portion 52B that is pushed down to open the valve is formed, and a through hole 52C is formed in the cam crest portion 52B. The cam crest portion 52B is a portion formed to protrude in the radial direction from a base circle portion 52A formed in an arc shape.
In the through hole 52C, a valve cam return spring 57 that biases the valve cam 52 in a direction in which the cam crest 52B moves away from the roller 51E of the rocker arm 51, that is, in a direction to close the intake valve 147 (see FIG. 5). One end of is attached. As shown in FIG. 5, the valve drive cam return spring 57 is wound around the intake side camshaft 151, and the other end is attached to the holder 53.

The holder 53 includes first and second plates 53A and 53B disposed at a predetermined interval in the axial direction of the intake camshaft 151 with the intake drive cam 153 and valve drive cam 52 interposed therebetween, and first and second plates. A connecting member 59 that connects the plates 53A and 53B in the axial direction of the intake camshaft 151 is provided. The first plate 53A is disposed on the side where the driven gear 82f is located, and the second plate 53B is disposed to face the first plate 53A with the connecting member 59 interposed therebetween.
The connecting member 59 includes shaft portions 59A and 59C that are parallel to the intake side camshaft 151, and a coupling portion 73 that integrally couples the shaft portion 59A and the shaft portion 59C. The coupling portion 73 is formed with a cylindrical housing portion 74, and the housing portion 74 houses a sub rocker arm return spring 58 (hereinafter referred to as a return spring) that biases the sub rocker arm 54 toward the intake drive cam 153. Has been.
The connecting portion 73 of the connecting member 59 is located at an intermediate portion between the first plate 53A and the second plate 53B, and the sub rocker arm support portion 59B to which one end of the sub rocker arm 54 is connected is connected to the connecting portion 73 and the first plate 53B. It is provided between the plate 53A. The sub rocker arm support portion 59B is a shaft formed with a smaller diameter than the shaft portion 59A.
The first and second plates 53A, 53B and the connecting member 59 are a pair of bolts 53D that fasten the first plate 53A and the connecting member 59 from the outer surface side of the first plate 53A, and an outer surface side of the second plate 53B. The second plate 53B and the connecting member 59 are fixed by a pair of bolts 53E.

  Further, as shown in FIG. 5, the first and second plates 53A and 53B have shaft holes 157A and 158A through which the intake side camshaft 151 passes, and the peripheral portions of these shaft holes 157A and 158A are holders. Ring-shaped convex portions 157B and 158B projecting toward the support portions 201D and 202D. The holder 53 is supported by the convex portions 157B and 158B being fitted to the holder support portions 201D and 202D, and can swing back and forth around the intake camshaft 151.

The sub rocker arm 54 is disposed between the first and second plates 53A and 53B together with the intake drive cam 153 and the valve cam 52, and is rotatably supported by the sub rocker arm support portion 59B of the connecting member 59 at one end thereof. The sub rocker arm support portion 59B swings about the center. At the center of the sub rocker arm 54, a roller 54A that contacts the intake drive cam 153 and presses the base circle portion 155A and the cam peak portion 155B is rotatably supported. One end of the connect link 55 is connected to the other end of the sub rocker arm 54 via a pin 55A that supports the connect link 55 so as to be swingable. The valve cam 52 is swung to the other end of the connect link 55. The valve cam 52 is connected via a pin 55B that supports the valve.
The sub rocker arm 54 is biased by a return spring 58, and the roller 54A of the sub rocker arm 54 is always pressed against the intake drive cam 153.

  The sub rocker arm 54 is connected to the sub rocker arm support portion 59B and extends downward so as to be orthogonal to the intake side camshaft 151, and downward from the holder connection portion 54B along the outer diameter of the intake side camshaft 151. It has an eccentric portion 54C that is curved, and a link portion 54D that is connected to the valve drive cam 52 via a connect link 55.

The eccentric portion 54C is eccentric in the axial direction of the intake side camshaft 151 so as to avoid the intake drive cam 153 from the first plate 53A side to the second plate 53B side, and on the side surface of the eccentric portion 54C, the intake side A plate-like stepped portion 76 projecting in the axial direction of the camshaft 151 is formed. As shown in FIGS. 4 and 6, the stepped portion 76 is provided so as to be curved along the lower edge portion of the sub rocker arm 54. The lower end of the return spring 58 is received by the stepped portion 76 via the spring washer 77.
The link portion 54D is provided continuously at the end of the eccentric portion 54C and is connected to the valve cam 52. As described above, the sub-rocker arm 54 connects the intake drive cam 153 and the valve cam 52 provided at different positions in the axial direction on the intake camshaft 151 by the eccentric portion 54C being eccentric.

Next, the operation of the intake side valve operating apparatus 50I in the valve operating apparatus 50 will be described.
In the valve operating apparatus 50 configured as described above, referring to FIG. 4, when the intake camshaft 151f is rotated counterclockwise in the drawing, the intake drive cam 153 rotates integrally with the intake camshaft 151f. The sub rocker arm 54 is pushed up via the roller 54A by the cam crest 155B and swings about the shaft 59A. Along with this, the valve cam 52 is centered on the intake camshaft 151f via the connect link 55. As shown in FIG. 4, the cam head 52B rotates in the clockwise direction, that is, in the direction in which the tip of the cam peak portion 52B rotates from the outside to the inside of the V bank 100. As the valve cam 52 rotates, the cam crest 52B presses the rocker arm 51 via the roller 51E, the intake valve 147 is pushed down via the rocker arm 51, and the intake valve 147 is opened.
Further, when the intake camshaft 151f is further rotated and the base circle portion 155A of the intake drive cam 153 is in contact with the roller 54A, the sub rocker arm 54 is pushed down by the return spring 58, and the valve cam 52 is returned to the valve cam return. The base 57 is brought into contact with the roller 51E by being rotated counterclockwise in FIG. 4 by the spring 57. As a result, the intake valve 147 is pushed up by the valve spring 149 (see FIG. 2) and closed.

In this valve operating device 50, as shown in FIG. 4, a connecting link member 63 is connected to the holder 53. When the connecting link member 63 is moved in the direction of arrow A, the position of the sub rocker arm support portion 59B (see FIG. 5) changes with the holder 53, and the link mechanism 56I rotates clockwise about the axis of the intake camshaft 151f. The roller 54A swings in the clockwise direction, and the valve cam 52 swings in the clockwise direction. On the other hand, when moving in the arrow B direction, the link mechanism 56I and the holder 53 swing counterclockwise about the axis of the intake camshaft 151f, and the roller 54A swings counterclockwise and the valve cam 52 swings counterclockwise. Thus, in the valve operating device 50, the valve operating characteristics of the intake valve 147 and the exhaust valve 148, that is, the opening and closing of the exhaust valve 148, are changed by changing the position of the roller 54A and the initial position of the swing of the valve operating cam 52. The timing, opening / closing period, and lift amount can be controlled.
Here, the initial position of the swing of the valve cam 52 is that the roller 54A of the sub rocker arm 54 is in contact with the base circle portion 155A of the intake drive cam 153 (exhaust drive cam 154 on the exhaust side). Indicates the swinging position of the valve cam 52 in a state where it is not pushed up by the cam crest 155B.

As shown in FIG. 7, the connection link member 63 is connected to the drive mechanism 60.
FIG. 7 is a longitudinal sectional view of the driving mechanism 60 as viewed from the side, and FIG. 8 is a longitudinal sectional view of the driving mechanism 60 as viewed from the front side.
As shown in FIG. 7, the drive mechanism 60 is connected to the holder 53 via a connection link member 63. The drive mechanism 60 includes a ball screw 61 disposed across the intake camshaft 151f and the exhaust camshaft 152f, a nut 62 provided near the intake camshaft 151f, and movable on the ball screw 61 in the axial direction. The connecting link member 63 is provided between the nut 62 and the holder 53.
A driven gear 64 is fixed to the end of the ball screw 61, and an electric actuator 70 (see FIG. 10) is connected to the driven gear 64 via a gear train. The driven gear 64 is disposed in front of the exhaust camshaft 152r.
The actuator 70 is controlled by an electronic control unit (ECU), and when the ECU drives the actuator 70, the holder 53 is swung via the ball screw 61, and the opening / closing operation characteristics of the intake valve 147 and the exhaust valve 148 are controlled. Is controlled according to the operating state of the engine 17.

The ball screw 61 is orthogonal to the intake camshaft 151f and the exhaust camshaft 152f, and is disposed on one end side of these camshafts 151f and 152f, that is, on the side opposite to the side where the cam chain 84f is provided. Thus, the ball screw 61 is not extended in the vertical direction of the engine 17, but is disposed across the intake camshaft 151f and the exhaust camshaft 152f, so that the height of the engine 17 can be kept low. become. As shown in FIG. 7, both ends of the ball screw 61 are supported by ball screw support portions 203 provided on the upper part of the cylinder head 132A, and are rotatable.
On the outer peripheral surface of the ball screw 61 on the side of the intake camshaft 151f, a helical thread 61A and a helical shaft thread groove 61C that engage with the nut 62 are formed.

  The nut 62 has a through hole 62A through which the ball screw 61 passes, and a spiral nut screw thread 62B corresponding to the thread 61A and a spiral corresponding to the shaft screw groove 61C are formed on the inner peripheral surface of the through hole 62A. A nut screw groove 62C is formed. A plurality of rollable balls 65 are arranged between the nut screw groove 62C and the shaft screw groove 61C. The nut 62 moves on the ball screw 61 via the ball 65 when the ball screw 61 is rotated.

As shown in FIGS. 7 and 8, the connecting link member 63 includes a nut side link 63A whose one end is fixed to the nut 62, and a holder side that connects the other end of the nut side link 63A and the second plate 53B. A link 63B and a connecting link 69 for connecting the holders 53 of the intake side valve operating device 50I and the exhaust side valve operating device 50E are provided.
One end of the nut side link 63 </ b> A sandwiches the nut 62 from both sides and is fixed to the nut 62 by a bolt 66. The other end of the nut side link 63A is supported by a pin 67 on one end of the holder side link 63B so as to be swingable. The other end portion of the holder side link 63B is swingably supported by the second plate 53B by an eccentric pin 68. The eccentric pin 68 includes a hexagon bolt 68A and an eccentric shaft 68B that is eccentrically formed integrally with the head of the hexagon bolt 68A. The hexagon bolt 68A is fixed to the second plate 53B by a spring washer 68C and a hexagon nut 68D, and the eccentric shaft 68B is rotatably supported by the nut side link 63A.

  The connecting link 69 connects the second plates 53B on the intake side and the exhaust side. That is, when the intake-side holder 53 is swung via the ball screw 61, the exhaust-side holder 53 connected by the connecting link 69 is linked to the intake-side holder 53 and is the same as the intake-side holder 53. Rocks in the direction. One end of the connecting link 69 is connected to the eccentric shaft 68B, and the other end of the connecting link 69 is connected to a connecting portion 53B1 formed at the edge of the second plate 53B on the exhaust side.

In FIG. 7, when the ball screw 61 is driven, the intake-side and exhaust-side holders 53 are swung in the same direction indicated by the arrow P or the arrow Q, and the link mechanisms 56I and 56E shown in FIG. It swings around the shaft 151f and the exhaust camshaft 152f.
By changing the positions of the link mechanisms 56I and 56E, the roller 54A and the valve cam 52 swing around the intake camshaft 151f and the exhaust camshaft 152f, respectively, with respect to the intake camshaft 151f and the exhaust camshaft 152f. Accordingly, the position is displaced in the circumferential direction, and the phase of the swing of the valve cam 52 with respect to the rotation of the intake drive cam 153 and the exhaust drive cam 154 and the initial position of the swing are changed. In this way, by changing the swing phase and swing position of each valve drive cam 52 with respect to each of the intake drive cam 153 and the exhaust drive cam 154, the cam crest portion 52B of each valve drive cam 52 is moved to the roller 51E. Since the contact timing, period, and amount by which the cam crest 52B pushes down the roller 51E can be changed, the opening / closing timing (phase), valve opening period, and lift amount of the intake valve 147 and the exhaust valve 148 can be changed. it can.

  In the intake side valve operating device 50I, when the holder 53 is swung in the clockwise direction (arrow A direction) in FIG. 4 by the drive mechanism 60, the roller 54A and the valve operating cam 52 are rotated in the clockwise direction. The peak portion 52B comes close to the roller 51E, and the roller 54A moves to a position that comes into contact with the cam peak portion 155B rotating in the counterclockwise direction at an earlier time. When the intake camshaft 151f is rotated in this state, the start timing of pushing up the roller 54A by the cam crest 155B is advanced, and the period and amount of push-down of the cam crest 52B pushing down the roller 51E are increased. Thereby, the valve opening timing of the intake valve 147 is advanced, and the valve opening period and the lift amount of the intake valve 147 are increased.

Further, since the exhaust side valve operating device 50E has substantially the same structure as the intake side valve operating device 50I except that the rotation direction of the exhaust cam shaft 152f is opposite to the intake cam shaft 151f, refer to FIG. The operation of the exhaust side valve operating apparatus 50E will be described.
In the exhaust side valve operating apparatus 50E, when the holder 53 is swung clockwise (in the direction of arrow A) in FIG. 4 by the drive mechanism 60, the roller 54A and the valve cam 52 are rotated in the clockwise direction. The peak portion 52B comes close to the roller 51E, and the roller 54A moves to a position where it contacts the cam peak portion 155B rotating in the clockwise direction at a later time. When the exhaust camshaft 152f is rotated in this state, the start timing of pushing up the roller 54A by the cam crest 155B is delayed, and the period and amount of push-down of the cam crest 52B pushing down the roller 51E are increased. Thereby, the valve opening timing of the exhaust valve 148 is delayed, and the valve opening period and the lift amount of the exhaust valve 148 are increased.

FIG. 9 is a diagram showing the valve operating characteristics of the intake valve 147 and the exhaust valve 148. The horizontal axis shows the rotation angle of the intake camshaft 151f and the exhaust camshaft 152f, and the vertical axis shows the intake valve 147 and the exhaust valve 148. The lift amount is shown.
As shown in FIG. 9, the intake valve 147 and the exhaust valve 148 are changed in opening / closing timing, opening / closing period, and maximum lift amount by the valve operating device 50 driven by the drive mechanism 60.
The intake valve 147 has a maximum valve operation characteristic Uimax that maximizes the lift amount of the intake valve 147 and a minimum valve operation characteristic Uimin that minimizes the lift amount of the intake valve 147 as boundary values. The valve is opened and closed with an arbitrary valve characteristic between the operating characteristic Uimax. Similarly, the exhaust valve 148 has the minimum valve operation characteristic Uemin with the maximum valve operation characteristic Uemax that maximizes the lift amount of the exhaust valve 148 and the minimum valve operation characteristic Uemin that minimizes the lift amount of the exhaust valve 148 as boundary values. And a maximum valve actuation characteristic Uemax.

  As the opening timing O1 of the intake valve 147 is continuously advanced, the closing timing C1 is continuously retarded to continuously increase the valve opening period, and further, the intake cam capable of obtaining the maximum lift amount. The rotation angle Ti of the shaft 151f is continuously advanced, and the maximum lift amount is continuously increased. The swing position of the valve cam 52 shown in FIG. 4 is the initial swing position where the minimum valve operation characteristic Uimin is obtained. From this state, the holder 53 is swung by the drive mechanism 60, and the valve cam 52 is shown in FIG. 4 is swung to the limit of the initial position of the clockwise swiveling, the swinging position at which the maximum valve operating characteristic Uimax is obtained.

  On the other hand, as the opening timing O2 of the exhaust valve 148 is continuously advanced, the closing timing C2 is continuously retarded, the valve opening period is continuously increased, and the maximum lift amount is obtained. The rotation angle Te of the exhaust camshaft 152f is continuously retarded and the maximum lift amount is continuously increased. The swing position of the valve cam 52 shown in FIG. 4 is the initial swing position where the minimum valve operation characteristic Uemin is obtained. From this state, the holder 53 is swung by the drive mechanism 60, and the valve cam 52 is shown in FIG. 4 is swung to the limit of the initial position of the clockwise swiveling, the swinging position at which the maximum valve operating characteristic Uemax is obtained.

As described above, in the valve operating apparatus 50, when the minimum valve operating characteristics Uimin and Uemin are changed to the maximum valve operating characteristics Uimax and Uemax, each of the intake side valve operating apparatus 50I and the exhaust side valve operating apparatus 50E is changed. By swinging the holder 53 in the same direction by the drive mechanism 60, the valve operating characteristics of the intake valve 147 and the exhaust valve 148 can be changed to desired characteristics. Specifically, in the intake valve 147, as the maximum valve operating characteristic Uimax is changed, the phase of the curve indicating the lift amount moves to the advance side, and the rotation angle Ti shifts to the advance side. In the exhaust valve 148, as the maximum valve operating characteristic Uemax is changed, the phase of the curve indicating the lift amount moves to the retard side, and the rotation angle Ti shifts to the retard side.
Further, the swing direction of each valve drive cam 52 when the characteristics are changed to the maximum valve operation characteristics Uimax, Uemax side is the respective movement when each valve drive cam 52 opens the intake valve 147 and the exhaust valve 148. This is the same direction as the swing direction of the valve cam 52. For this reason, a desired valve operating characteristic can be obtained by a simple configuration in which the link mechanisms 56I and 56E are swung in the same direction via the holders 53 by the drive mechanism 60.

FIG. 10 is a plan view showing the valve gears 50 of the front bank 110A and the rear bank 110B.
As shown in FIGS. 2 and 10, in the front bank 110A, the exhaust side valve operating device 50E and the intake side valve operating device 50I are positioned side by side in front of and behind the cylinder bore 135, and each sub rocker arm 54 is in the same direction. It is arranged in a facing state. Specifically, each holder 53 is arranged in a state where each link portion 54D of the sub rocker arm 54 is directed to the rear side. The actuator 70 is fixed to the right side surface of the front portion of the front cylinder head 132 </ b> A and is connected to the driven gear 64 of the ball screw 61.
Furthermore, the front bank 110A and the rear bank 110B have substantially the same internal structure including the valve gear 50, the drive gears 81f and 81r, the driven gears 82f and 82r, the transmission gears 83f and 83r, and the cam chains 84f and 84r. The rear bank 110B is configured such that the entire front bank 110A is rotated by 180 ° about the cylinder bore 135 and attached to the rear portion of the crankcase 110C.

  That is, as described above, the drive gear 81f and the driven gear 82f of the front bank 110A are the same parts, and the front bank 110A and the rear bank 110B are configured in the same way, so the intake side camshaft 151 and the exhaust side camshaft. A gear for driving 152 can be configured by using four drive gears 81f. For this reason, since the drive gear 81f can be shared, the valve gear 50 can be realized with a simple structure. Moreover, since the transmission gears 83f and 83r, the cam chains 84f and 84r, and the drive sprocket 163 can be shared by the front and rear banks 110A and 110B, the types of parts can be reduced.

  Further, in the present embodiment, each of the drive gears 81f and 81r is directly meshed with the driven gears 82f and 82r, so that the rotation of each of the exhaust camshafts 152f and 152r and each of the intake camshafts 151f and 151r. The rotations are reversed from each other. Thus, by swinging the link mechanisms 56I and 56E in the same direction via the holders 53, the roller 54A can come into contact with the cam nose 155B earlier than the intake drive cam 153. With respect to the cam 154, the roller 54A can hit the cam crest 155B at a later time, and the valve operating characteristics of the intake valve 147 and the exhaust valve 148 can be changed to desired characteristics. For this reason, the intake side valve operating device 50I and the exhaust side valve operating device 50E can be arranged in the same direction, and can be constituted by the same parts. That is, the sub rocker arm 54, the first and second plates 53A and 53B, the connecting member 59, the rocker arm 51, and the like are composed of the same components on the intake side and the exhaust side in both the front bank 110A and the rear bank 110B. it can. Further, the valve cam 52 can be configured identically on the intake side and the exhaust side except for the cam profile portion. For this reason, the types of parts can be reduced, and the valve gear 50 can be realized with a simple structure.

  Furthermore, in order to change the valve operating characteristics of the intake valve 147 and the exhaust valve 148 by swinging the holders 53 in the same direction, the holders 53 on the intake side and the exhaust side are connected to each other with a simple structure such as the connecting link 69. By connecting, the intake side and exhaust side holders 53 can be interlocked. For this reason, the structure of the drive mechanism 60 can be simplified. Furthermore, since the drive mechanism 60 can be simply structured by a single connecting link 69 and a space can be secured, the degree of freedom in arranging the actuator 70 can be improved. For example, here, it has been described that the driven gear 64 is disposed in front of the exhaust camshaft 152 and the actuator 70 is disposed in front of the front cylinder head 132A. However, the exhaust camshaft 152f and the intake camshaft 151f are described. The driven gear 64 and the actuator 70 may be disposed in the vicinity of the connection link 69.

  As described above, according to the embodiment to which the present invention is applied, each of the front bank 110A and the rear bank 110B is connected to the intake side and the exhaust side via the cam chains 84f and 84r and the drive gears 81f and 81r, respectively. , Each of the cam chains 84f and 84r and each of the drive gears 81f and 81r can be made the same part by the front bank 110A and the rear bank 110B. For this reason, parts can be shared and the types of parts can be reduced, and the valve gear 50 of the V-type engine 17 can be realized with a simple structure. Further, since the intake cams 80I of the front bank 110A and the rear bank 110B are provided inside the V bank 100, the intake parts such as the intake port 145 and the intake chamber 43 are efficiently arranged together in the V bank space K. it can.

  Further, since the rocking directions of the valve cams 52 when the rocker arm 51 is pressed by the valve cam 52 to drive the intake valve 147 and the exhaust valve 148 are the same, the sub rocker arm is on the intake side and the exhaust side. 54, the first and second plates 53A and 53B, the connecting member 59, the rocker arm 51, and the like can be configured by the same component. For this reason, the parts of the valve operating apparatus 50 can be shared, and the valve operating apparatus 50 can be realized with a simple structure.

  Further, since the swing directions of the link mechanisms 56I and 56E when changing the valve operating characteristics of the intake valve 147 and the exhaust valve 148 are the same, the sub rocker arm 54, the first and second The parts such as the plates 53A and 53B, the connecting member 59, and the rocker arm 51 can be configured by the same part. For this reason, the parts of the valve operating apparatus 50 can be shared, and the valve operating apparatus 50 can be realized with a simple structure. Further, since the swing directions of the link mechanisms 56I and 56E are the same, the intake-side and exhaust-side holders 53 are connected to each other with a simple structure using a single connection link 69, and the intake-side valve operating device 50I and the exhaust side valve operating apparatus 50E can be interlocked. Thereby, the structure of the valve operating apparatus 50 can be simplified. Further, since the intake side valve operating device 50I and the exhaust side valve operating device 50E are connected using a single connecting link 69, a space can be secured around the connecting link 69, and this space can be used effectively to provide an actuator. The degree of freedom of arrangement of 70 can be improved.

Further, since the exhaust valves 148 located in the outer direction of the V bank 100 in the front bank 110A and the rear bank 110B are arranged at angles closer to the centers of the front bank 110A and the rear bank 110B, the intake valves The sandwiching angle between 147 and the exhaust valve 148 is reduced. Therefore, a large space outside the V bank 100 can be secured, and a larger space can be secured outside the V bank 100, that is, before and after the V bank 100.
Furthermore, since the spark plug 142 is inclined forward toward the exhaust side valve operating apparatus 50E, the distance between the rocker arm pivot 51A on the side close to the spark plug 142 and the spark plug 142 can be further secured. Since it is not necessary to form relief in the rocker arm 51 on the side close to the plug 142, the valve operating device 50 can be made simple by sharing the rocker arm 51 on the intake side and the exhaust side. In addition, since the spark plug 142 is tilted and arranged, the degree of freedom of arrangement of the intake valve 147 and the exhaust valve 148 is improved. Therefore, the arrangement of the intake valve 147 and the exhaust valve 148 with respect to the combustion chamber 140 is adjusted, and the combustion chamber 140 Can be brought close to the ideal shape.

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 valve gear 50 has been described as being capable of changing the opening / closing timing (phase), valve opening period, and lift amount of the intake valve 147 and the exhaust valve 148, but the present invention is not limited thereto. The present invention is not limited, and can be applied to a valve gear that can change the opening / closing timing (phase) and / or lift amount of the intake valve 147.

  In the above embodiment, in the front bank 110A and the rear bank 110B, the rocker arm pivots 51A on the intake side and the exhaust side are arranged on the outer side of the V bank 100 with respect to the corresponding action portions 51B. Explained as a thing. The invention of the present application is not limited to this, and the intake side valve operating device is arranged in such a direction that the rocker arm pivots 51A on the intake side and the exhaust side are arranged on the inner side of the V bank 100 with respect to the corresponding action portions 51B. 50I and the exhaust side valve operating apparatus 50E may be arranged. This case will be described as a modified example.

[Modification]
FIG. 11 is a side view showing the rear bank 110B in a modification of the embodiment.
In addition, in this modification, about the part comprised similarly to the said embodiment, a same sign is attached | subjected and description is abbreviate | omitted.

As shown in FIG. 11, in the modification, the intake side valve operating device 50I and the exhaust side valve operating device 50E are located on the inner side of the V bank 100 with respect to the action portions 51B corresponding to the respective rocker arm pivots 51A. It is arranged in the direction. That is, in the intake side valve operating device 50I and the exhaust side valve operating device 50E, the orientation of the intake camshaft 151r and the exhaust camshaft 152r is the same as that in the above embodiment, and the holder 53, the link mechanisms 56I and 56E, The cam 52, the rocker arm 51, and the like are arranged in the opposite direction to the above-described embodiment, and each valve cam 52 is configured such that the tip of the cam peak portion 52B rotates from the inside to the outside of the V bank 100. Push the rocker arm 51 down. Here, in the engine 170 of the modified example, the crankshaft 105 rotates in the counterclockwise direction in FIG. 11, the intake camshaft 151r is rotated in the counterclockwise direction via the cam chain 84r, and the exhaust camshaft 152r. Is rotated clockwise.
Although not shown, the rocker arm pivots 51A are also arranged in the front bank 110A so that the rocker arm pivots 51A are positioned on the inner side of the V bank 100 with respect to the corresponding action portions 51B.

  For this reason, the action part 51B of the rocker arm 51 on the intake side can be disposed close to the spark plug 142, and each intake valve 147 disposed on the inner side of the V bank 100 in the front bank 110A and the rear bank 110B They can be arranged along the spark plug 142 at an angle close to the spark plug 142 side. As a result, the valve clamping angle between the intake valve 147 and the exhaust valve 148 in the front bank 110A and the rear bank 110B is reduced, so that the intake side valve operating device 50I can be arranged close to the spark plug 142 side. As a result, a large V bank space K on the inner side of the V bank 100 can be secured, and the degree of freedom of arrangement of components such as the air cleaner 41, the throttle body 42, and the injector 143 arranged in the V bank space K is improved. it can.

17, 170 Engine (V-type internal combustion engine)
50 Valve operating device 50E Exhaust side valve operating device (variable valve operating mechanism)
50I Intake valve mechanism (variable valve mechanism)
51 Rocker arm 51A Rocker arm pivot (fulcrum)
51B Action part (action point)
52 Valve cam (oscillating cam)
54A Roller 56E, 56I Link mechanism 70 Actuator 80E Exhaust cam 80I Intake cam 81f, 81r Drive gear (gear)
84f Cam chain (Transmission member of one bank)
84r cam chain (transmission member of the other bank)
100 V bank 105 Crankshaft 110A Front bank (one bank)
110B after bank (the other bank)
131A Front cylinder block (cylinder block)
131B Rear cylinder block (cylinder block)
140 Combustion chamber 142 Spark plug 147 Intake valve (engine valve)
148 Exhaust valve (engine valve)
151 Intake camshaft (camshaft)
152 Exhaust side camshaft (camshaft)

Claims (5)

The cylinder block (131A, 131B) is arranged in a V shape, and the V is provided with a variable valve mechanism that makes the phase and / or lift amount of the engine valve (147, 148) interlocked with the camshaft (151, 152) variable. In the valve operating device of the internal combustion engine,
Intake cam of one bank (110A) (80I) or the intake cam to rotation of the exhaust cam crankshaft (105) for rotating the (80E) (80I) or transmission member for transmitting to the exhaust cam (80E) (84f) When,
Transmitting the rotation of one of the banks (110A) rotates the transmitted intake cam by transmitting member (84f) of (80I) or the exhaust cam (80E) on the intake cam of the same bank (110A) (80I) or the exhaust cam (80E) A gear (81f) to perform,
The intake cam of the other bank (110B) (80I) or the intake cam to rotation of the exhaust cam crankshaft for rotating (80E) (105) (80I ) or transmission member for transmitting to the exhaust cam (80E) (84r) When,
Transmitting the rotation of the rotation transmission intake air cam (80I) or the exhaust cam (80E) a transfer member of the other bank (110B) (84r) on the intake cam of the same bank (110B) (80I) or the exhaust cam (80E) And one and the other intake cam ( 80I, 80I ) are provided inside the V bank (100) ,
The intake cam (80I) and the exhaust cam (80E) press the intermediate portion between the fulcrum (51A, 51A) and the operating point (51B, 51B) of the rocker arm (51, 51) to press the engine valve (147, 148). The swing cams (52, 52) have the same swinging direction, and the fulcrum (51A, 51) of the rocker arms (51, 51) on the exhaust side and the intake side are included. 51A) is a valve operating device for a V-type internal combustion engine, which is provided in the same direction . A link mechanism (56I, 56E) that swings around the camshaft (151, 152) having the intake cam (80I) or the exhaust cam (80E ) and supports the swing cam (52, 52). Prepared,
By changing the swing position of the link mechanism (56I, 56E ) by the actuator (70) , the phase and / or lift amount of the engine valve (147, 148) is made variable,
The swing direction of the link mechanism (56I, 56E) when changing the phase and / or lift amount of the engine valve (147, 148) is the same on the intake side and the exhaust side;
The valve operating apparatus for a V-type internal combustion engine according to claim 1 . The swing direction of the swing cam (52, 52) is, when the leading edge of the swing cam (52, 52) is rotated from the outside toward the inside of the V bank (100), said engine valve (147, 148) , and the fulcrum (51A, 51A) of the rocker arm (51 , 51) is disposed outward of the V bank (100) .
The valve operating apparatus for a V-type internal combustion engine according to claim 1 or 2, wherein The swing direction of the swing cam (52, 52) is, when the leading edge of the swing cam (52, 52) is rotated from the inside to the outside of the V bank (100), said engine valve (147, 148) , and the fulcrum (51A, 51A) of the rocker arm (51 , 51) is disposed in the inner direction of the V bank (100) ,
The valve operating apparatus for a V-type internal combustion engine according to claim 1 or 2, wherein A combustion chamber (140) central to the spark plug (142) is provided, the spark plug (142), the opposite side of the fulcrum (51A) of the rocker arm on the side close to the ignition plug (142) (51) The rocker arm (51) is provided on the fulcrum (51A) side of the rocker arm (51) .
The valve operating apparatus for a V-type internal combustion engine according to claim 3 or 4 , characterized in that:

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