JP5271238B2 - V-type internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a V-type internal combustion engine capable of disposing a fuel injection device provided in an optimum position, and facilitating work for mounting and demounting the fuel injection device. <P>SOLUTION: The V-type internal combustion engine 17 includes a pair of front and rear banks 110A, 110B disposed in a V-shape where an intake port 145 of the front and rear banks 110A, 110B is provided inside the V-bank of the front and rear banks 110A, 110B. The intake port 145 includes a lower intake port 145B integrated with cylinder heads 132A, 132B, and an upper intake port 145C separated from the cylinder heads 132A, 132B and connected to an upper end 145D of the lower intake port 145B. The upper intake port 145C is turned and extended in directions close to the head covers 133A, 133B of the cylinder heads 132A, 132B. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a V-type internal combustion engine that directly injects fuel into a combustion chamber.

  In a V-type internal combustion engine in which a pair of front and rear banks are arranged in a V-type, there is an in-cylinder injection type internal combustion engine that directly injects fuel into a combustion chamber from an injector that is a fuel injection device. In this internal combustion engine, the angle between the front bank and the rear bank (bank angle) is set to a narrow angle of 45 to 50 degrees, and the intake ports of the front and rear banks are arranged inside the V bank (for example, Patent Document 1). reference).

JP 2005-36681 A

Incidentally, in an in-cylinder injection type internal combustion engine, in order to improve ignition performance and the like, it is preferable to place the injector on the intake port side with respect to the cylinder axis of the bank.
However, in the above-described conventional configuration, the bank angle is too narrow to place the injector inside the V bank on the intake port side, and operations such as attachment and removal of the injector cannot be performed. Therefore, the injector can only be arranged upright along the cylinder axis, and the injector cannot be provided at an optimal position.
Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a fuel injection device at an optimal position, and to facilitate work such as attachment and removal of the fuel injection device. It is to provide an internal combustion engine.

To solve the above problems, the present invention is provided with a longitudinal and arranged in a V-type pair of banks (110A, 110B), the intake ports of the front and rear banks (110A, 110B) V bank inside the front and rear banks (110A, 110B) In the V-type internal combustion engine provided with (145, 145) , the intake port (145, 145) includes a lower intake port (145B, 145B) integral with the cylinder head (132A, 132B) and the cylinder head (132A, 132B) and an upper intake port (145C, 145C) connected to the upper end of the lower intake port (145B, 145B) , and the upper intake port (145C, 145C) is connected to the cylinder head ( 132A, extend a different angle in the direction toward the head cover (133A, 133B) of 132B), The upper intake ports (145C, 145C) of the pair of banks (110A, 110B) before and after the above extend upward substantially parallel to each other and are arranged at the upper ends of the upper intake ports (145C, 145C) inside the V bank. The intake chamber (43) is connected, and one upper intake port (145C, 145C) of the front and rear banks (110A, 110B) is formed of an elastic member .

According to the above configuration, since the intake port includes the lower intake port provided integrally with the cylinder head and the upper intake port provided separately from the cylinder head, for example, the upper intake port can be removed from the cylinder head. Therefore, even when the bank angle is narrow, operations such as attachment and removal of the fuel injection device can be performed. Further, since the upper intake port extends at a different angle in the direction approaching the head cover of the cylinder head, the space between the banks can be increased.

In addition, since the upper end portion of the upper intake port connecting the intake chamber is located in the upper portion inside the V bank having a larger space, the intake chamber can be easily arranged even if the bank angle is narrow. Further, for example, by setting a length difference in one of the pair of front and rear upper intake ports, a gap and stress generated on the mating surface between the pair of front and rear upper intake ports and the intake chamber can be suppressed.
Further, when the elastic member is elastically deformed, it is possible to further absorb the step and the angle shift of the mating surface between the pair of front and rear intake ports and the absorption chamber .

In the V-type internal combustion engine described above, at least a portion of one said upper intake port of the front and rear banks (110A, 110B) (145C) may be formed of an elastic member.
According to the above configuration, it is possible to further absorb the step and the angular deviation of the mating surfaces of the pair of front and rear intake ports and the absorption chamber while ensuring the rigidity required for the upper intake port .

In the V-type internal combustion engine, the elastic member may be formed by dividing the upper intake port (145) into two parts in the vertical direction .
According to the above configuration , the upper and lower lengths of the upper intake port can be easily adjusted by elastically deforming the elastic member vertically .

In the V-type internal combustion engine, the elastic member may be formed by baking rubber on a metal surface .
According to the above configuration, since the elastic member is integrated with the upper intake port, the upper intake port can be handled as one component .

In the V-type internal combustion engine, the upper intake port (145C) has a flange (301) connected to the lower surface of the intake chamber (43) on the upper side and an upper end of the lower intake port (145B) on the lower side. The elastic body (303) is formed by baking an elastic member such as rubber on the surface of the flange (301) and the intake pipe (302). A substantially annular base portion (303A) for connecting the pipe (302) and the flange (301), and an extension portion (303B) extending from the base portion (303A) along the outer peripheral surface of the intake pipe (302) but it may also be provided with a door.

  According to the present invention, since the intake port includes the lower intake port provided integrally with the cylinder head and the upper intake port provided separately from the cylinder head, the upper intake port can be removed from the cylinder head, for example. Therefore, even when the bank angle is narrow, it is possible to attach and remove the fuel injection device, and as a result, the fuel injection device can be provided inside the V bank which is the optimum position. In addition, the upper intake port extends at a different angle in the direction close to the head cover of the cylinder head, so that the space between the banks can be increased, and the work of attaching and removing the upper intake port is facilitated. .

  Further, the upper intake ports of the pair of front and rear banks extend upward substantially parallel to each other, and the upper intake ports that connect the intake chambers are connected to the upper ends of the upper intake ports because the intake chambers arranged inside the V bank are connected. Since the upper end portion of the V is located in the upper portion inside the V bank having a larger space, the intake chamber can be easily arranged. Further, for example, by setting a length difference in one of the pair of front and rear upper intake ports, a gap and stress generated on the mating surface between the pair of front and rear upper intake ports and the intake chamber can be suppressed.

  Furthermore, since the fuel injection device is provided below the lower intake port, the fuel injection device is disposed on the intake port side and lying on the cylinder shaft, so that the ignition performance and the like are improved. Further, since the fuel injection device is provided along the lower intake port, the fuel injection device can be prevented from protruding from the bank, and the bank can be downsized. As a result, the space between the banks can be increased, and operations such as attachment and removal of the fuel injection device are facilitated.

  In addition, since the upper intake port of one of the front and rear banks is formed of an elastic member, the elastic member is elastically deformed, so that the step and angle shift of the mating surface between the pair of front and rear intake ports and the absorption chamber can be more absorbed. The stress on the surface can be further suppressed and the sealing performance can be improved.

  In addition, since at least a part of one upper intake port of the front and rear banks is formed of an elastic member, the step and angular deviation of the mating surfaces of the pair of front and rear intake ports and the absorption chamber are secured while ensuring the rigidity required for the upper intake port. Therefore, the stress applied to the mating surface between the pair of front and rear upper intake ports and the intake chamber can be further suppressed, and the sealing performance can be improved.

  In addition, since the elastic member is formed by dividing the upper intake port into two parts in the vertical direction, the vertical length of the upper intake port can be easily adjusted by elastically deforming the elastic member in the vertical direction. The stress applied to the mating surface between the upper intake port and the intake chamber can be further suppressed, and the sealing performance can be improved.

  In addition, since the elastic member is formed by baking rubber on the metal surface, the elastic member is integrated with the upper intake port, so the upper intake port can be handled as one part, and the upper intake port is easily attached Can be removed.

1 is a side view showing a motorcycle equipped with an engine according to an embodiment of the present invention. It is a side view which shows the internal structure of an engine. FIG. 3 is an enlarged side view showing an engine intake system of FIG. 2. It is a side view which expands and shows the internal structure of the front bank of FIG. It is a 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 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 the cross-sectional view which looked at the engine from the upper part. It is the cross-sectional view which looked at the engine from the upper part. It is a side view which expands and shows the engine intake system which concerns on another 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 side view showing a motorcycle to which an engine 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 is formed with an angle between the front bank 110A and the rear bank 110B (also referred to as a bank angle) constituting each cylinder 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.
An air cleaner 41 and a throttle body 42 that constitute an engine intake system are disposed in a V-shaped space formed by the front bank 110A and the rear bank 110B. 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 side view of the internal structure of the engine 17, FIG. 3 is an enlarged side view of the engine intake system of FIG. 2, and FIG. 4 is an internal view of the front bank 110A of FIG. It is a figure which expands and shows a structure.
In FIG. 2, the front bank 110A and the rear bank 110B of the engine 17 have the same structure. 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. 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. These shafts 121, 123, and 125 including the crankshaft 105 are arranged in parallel with each other by shifting in the longitudinal direction and the vertical direction of the vehicle body. A gear transmission mechanism is configured to transmit 121, the main shaft 123, and the counter shaft 125 in this order.

  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 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. Since the two connecting rods 137 of the front and rear banks 110A and 110B are connected to the common crankshaft 105, the connecting rod 137 of the rear bank 110B is disposed adjacent to the left side of the vehicle body of the connecting rod 137 of the front bank 110A.
Combustion recesses 141 constituting the top surface of the combustion chamber formed above the piston 136 are formed on the lower surfaces of the cylinder heads 132A and 132B, and the ignition plugs 142 face the tips of the combustion recesses 141. Be placed. The spark plug 142 is provided substantially coaxially with the cylinder axis C.

The engine 17 is an in-cylinder injection engine that directly injects fuel into a combustion chamber from an injector 143 (fuel injection device) provided in each combustion recess 141. Each injector 143 is inserted from the V bank inner side surface of each cylinder head 132A, 132B, 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 is formed with an intake port 145 communicating with each combustion recess 141 through a pair of openings 145A and an exhaust port 146 communicating with each combustion recess 141 through a pair of openings 146A. Yes. The intake port 145 is disposed between the cylinder axis C and the injector 143.
As shown in FIGS. 2 and 3, the intake ports 145 merge at the intake chamber 43, and the intake chamber 43 is connected to the throttle body 42. 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).

  As shown in FIG. 2, the cylinder heads 132A and 132B include a pair of intake valves 147 (engine valves) that open and close the opening 145A of the intake port 145 and a pair of exhaust valves that open and close the opening 146A of the exhaust port 146. 148 (engine valve) is arranged. 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 valve bodies 147 and 148 are driven by a valve gear 50 that can change valve operating characteristics such as opening / closing timing and lift amount. The valve operating device 50 is rotatably supported by the cylinder heads 132A and 132B, and includes intake-side and exhaust-side camshafts 151 and 152 (camshafts) that rotate in synchronization with the rotation of the engine 17.

  As shown in FIG. 4, the camshaft 151 is integrally formed with an intake cam 153 (drive cam). The intake cam 153 includes a base circle portion 153A that forms a circular cam surface, and a cam peak portion 153B that protrudes outward from the base circle portion 153A to form a mountain-shaped cam surface. The camshaft 152 is integrally formed with an exhaust cam 154 (drive cam). The exhaust cam 154 includes a base circle portion 154A that forms a circular cam surface, and a cam peak portion 154B that protrudes from the base circle portion 154A toward the outer peripheral side to form a mountain-shaped cam surface.

  As shown in FIG. 2, the intermediate shaft 158 is rotatably supported at one end side in the width direction of the cylinder heads 132 </ b> A and 132 </ b> B, and the intermediate sprockets 159 and 160 are fixed to the intermediate shaft 158. A driven sprocket 161 is fixed to one end of the camshaft 151, a driven sprocket 162 is fixed to one end of the camshaft 152, and a driving sprocket 163 is fixed to both ends of the crankshaft 105. A first cam chain 164 is wound between the sprockets 159 and 163, and a second cam chain 165 is wound between the sprockets 160 to 162. These sprockets 159 to 163 and cam chains 164 and 165 are accommodated in a cam chain chamber 166 formed on one end side of each of the banks 110A and 110B.

  The reduction ratio from the drive sprocket 163 to the driven sprockets 161 and 162 is set to 2, and when the crankshaft 105 rotates, the drive sprocket 163 rotates together with the crankshaft 105 and the driven sprocket 161 via the cam chains 164 and 165. , 162 rotate at half the rotational speed of the crankshaft 105, and the intake valve 147 and the exhaust valve 148 become the intake port 145 and the exhaust port 146 according to the cam profile of the camshafts 151, 152 rotating integrally with the driven sprockets 161, 162. Open and close each.

  A generator (not shown) is provided at the left end portion of the crankshaft 105, and a drive gear (hereinafter referred to as a crank side drive gear) 175 is provided at the right end portion of the crankshaft 105 on the inner side (left side of the vehicle body) of the right drive sprocket 163. Is fixed. 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. 5 is a side view showing the valve gear 50, and FIG. 6 is a longitudinal sectional view of the valve gear 50 of the front bank 110A as seen from the rear side.
As shown in FIG. 4, the valve gear 50 is provided symmetrically independently on the intake side and the exhaust side about the cylinder axis C. Since the valve gears 50 of the front bank 110A and the rear bank 110B have substantially the same structure, in this embodiment, the valve gear 50 on the intake side of the front bank 110A will be described.

  As shown in FIGS. 5 and 6, the valve gear 50 includes a camshaft 151 (camshaft 152 on the exhaust side), an intake cam 153 that rotates integrally with the camshaft 151 (exhaust cam 154 on the exhaust side), an intake air A rocker arm 51 that opens and closes a valve 147 (exhaust valve 148 on the exhaust side), a valve cam 52 that is supported by the camshaft 151 so as to be relatively rotatable, and that opens and closes the intake valve 147 via the rocker arm 51, and around the camshaft 151 And a link mechanism 56 that is supported by the holder 53 so as to be swingable, transmits the valve driving force of the intake cam 153 to the valve cam 52, and swings the valve cam 52. And a drive mechanism 60 that swings the holder 53. Further, the link mechanism 56 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 rocker arm 51 is formed wide, and the pair of intake valves 147 are opened and closed by one rocker arm 51. The rocker arm 51 is swingably supported at one end by a rocker arm pivot 51A fixed to the cylinder head 132A. The other end of the rocker arm 51 is provided with a pair of adjustment screws 51B that contact the upper end of each intake valve 147, and a roller 51C that contacts the valve cam 52 is rotatably supported at the center. .

  As shown in FIG. 6, the camshaft 151 has a sprocket fixing portion 151A to which a driven sprocket 161 (see FIG. 2) is fixed on one end side, and is arranged on the outer periphery of the camshaft 151 in order from the sprocket fixing portion 151A side. Positioning portion 151B having a protruding circular shape, intake cam 153, swing cam support portion 151C for swingably supporting valve cam 52, and collar fitting formed with a smaller diameter than swing cam support portion 151C A portion 151D is provided. A camshaft collar 155 that functions as a bearing for the camshaft 151 is fitted to the collar fitting portion 151D, and the camshaft collar 155 is fixed to the other end side of the camshaft 151 by a fixing bolt 156. It is pressed to the side.

Both ends of the 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, so that the cam The shaft 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 cam 153, respectively.

  The valve cam 52 is disposed on a swing cam support portion 151 </ b> C provided at an intermediate portion of the camshaft 151. As shown in FIG. 5, the valve operating cam 52 is formed with a base circle portion 52A for maintaining the intake valve 147 in a closed state, and a cam peak portion 52B for pushing the intake valve 147 down to open it. A through hole 52C is formed in the portion 52B. 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 51C of the rocker arm 51, that is, in a direction to close the intake valve 147 (see FIG. 6). One end of is attached. As shown in FIG. 6, the valve drive cam return spring 57 is wound around the 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 camshaft 151 with the intake cam 153 and the valve cam 52 interposed therebetween, and the first and second plates 53A, And a connecting member 59 for connecting 53B in the axial direction of the camshaft 151. The first plate 53A is disposed on one end side to which the driven sprocket 161 of the camshaft 151 is fixed, and the second plate 53B is disposed on the other end side of the camshaft 151.
The connecting member 59 has a shaft portion 59A parallel to the camshaft 151, and a sub rocker arm support portion 59B (fulcrum) to which one end of the sub rocker arm 54 is connected to the end of the shaft portion 59A on the first plate 53A side. ) Is formed. The connecting member 59 is fixed to the first and second plates 53A and 53B by a pair of bolts 53D inserted into both ends of the shaft portion 59A from the outer surface side of the first and second plates 53A and 53B. The connecting member 59 includes a shaft portion 59C parallel to the shaft portion 59A, and a pair of bolts (not shown) inserted into both ends of the shaft portion 59C from the outer surface side of the first and second plates 53A and 53B. ) Is also fixed to the first and second plates 53A and 53B.

  The first and second plates 53A and 53B have shaft holes 157A and 158A through which the camshaft 151 passes, and the peripheral portions of the shaft holes 157A and 158A protrude toward the holder support portions 201D and 202D. The annular convex portions 157B and 158B are formed. 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 around the camshaft 151.

The sub rocker arm 54 is disposed between the first and second plates 53A and 53B together with the intake 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. The rocker arm support part 59B swings around. A roller 54 </ b> A that contacts the intake cam 153 is rotatably supported at the center of the sub rocker arm 54. One end of the connect link 55 is connected to the other end of the sub rocker arm 54 via a pin 55A (see FIG. 5) that supports the connect link 55 so as to be swingable. The valve cam 52 is connected via a pin 55B (see FIG. 5) that supports the cam 52 in a swingable manner.
Further, as shown in FIG. 5, the sub rocker arm 54 is biased by a sub rocker arm return spring 58 accommodated in the connecting member 59, and the roller 54 </ b> A of the sub rocker arm 54 is always pressed against the intake cam 153. Here, the sub rocker arm return spring 58 is a coil spring.

Next, the operation will be described.
In the valve operating apparatus 50 configured as described above, referring to FIG. 5, when the camshaft 151 is rotated, the sub rocker arm 54 is rotated by the cam peak portion 153 </ b> B of the intake cam 153 that rotates integrally with the camshaft 151. It is pushed up through 54A and swings about the shaft portion 59A, and accordingly, the valve cam 52 rotates around the camshaft 151 in the clockwise direction through the connect link 55. As the valve cam 52 rotates, the cam crest 52B pushes down the intake valve 147 together with the rocker arm 51 via the roller 51C, and the intake valve 147 is opened. When the camshaft 151 is further rotated and the base circle portion 153A of the intake cam 153 is in contact with the roller 54A, the sub rocker arm 54 is pushed down by the sub rocker arm return spring 58 and the valve cam 52 is moved. The base 57 is brought into contact with the roller 51C by being rotated counterclockwise in FIG. 5 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. 5, 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 holder 53 swings clockwise about the axis of the intake side camshaft 151, and the sub rocker arm support portion 59B is displaced downward in the figure, and the direction of arrow B Is moved counterclockwise about the axis of the intake camshaft 151, and the sub rocker arm support portion 59B is displaced upward in the drawing.
Thus, the valve operating apparatus 50 is configured to be able to change the operating characteristics of opening and closing of the intake valve 147 and the exhaust valve 148.
As shown in FIG. 7, the connection link member 63 is connected to the drive mechanism 60.

7 is a longitudinal sectional view of the drive mechanism 60 viewed from the side, FIG. 8 is a longitudinal sectional view of the drive mechanism 60 viewed from the front side, and FIG. 9 is a view of the engine 17 viewed from above. It is a cross-sectional view. In FIG. 9, the front and rear banks 110A and 110B are viewed from above the engine 17 along the cylinder axis C (see FIG. 2).
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 is provided on each of the intake side and exhaust side ball screws 61 disposed across the intake side camshaft 151 and the exhaust side camshaft 152, and is movable in the axial direction on the ball screw 61. Two nuts 62 (sliders) are provided, and a connecting link member 63 is provided between the nut 62 and the holder 53.

A gear 64 is fixed to one end portion on the exhaust side of the ball screw 61, and an electric actuator 70 for rotating the ball screw 61 is connected to the gear 64 by a gear train as shown in FIG. The electric actuator 70 includes an electric motor 71, a driving shaft 72 (axis) of the electric motor 71, and an intermediate shaft 73 to which the driving force of the electric motor 71 is transmitted from the driving shaft 72. The electric motor 71 is disposed with its drive shaft 72 substantially parallel to the top surfaces of the head covers 133A and 133B.
A drive gear 72A is formed on the drive shaft 72, a first intermediate gear 73A that meshes with the drive gear 72A, and a second intermediate gear 73B that meshes with the gear 64 provided on the ball screw 61. Is fixed.
The pair of front and rear banks 110A and 110B are disposed offset from each other in the axial direction of the camshafts 151 and 152 extending in the left-right direction of the vehicle body (vertical direction in FIG. 9). More specifically, the cylinder center line CA in the vehicle longitudinal direction of the front bank 110A is offset in the vehicle body right direction (downward in FIG. 9), and the cylinder center line CB in the vehicle longitudinal direction of the rear bank 110B is in the vehicle left direction ( In FIG. 9, it is offset upward).

The ball screw 61 is orthogonal to the camshafts 151 and 152, and is disposed on the other end side of these camshafts 151 and 152, that is, on the side opposite to the side on which the driven sprockets 161 and 162 are fixed. As described above, the ball screw 61 is not extended in the vertical direction of the engine 17 but is disposed so as to straddle the intake side camshaft 151 and the exhaust side camshaft 152, so that the height of the engine 17 is kept low. It becomes possible. Both ends of the ball screw 61 are rotatably supported by ball screw support portions 203, respectively. As shown in FIG. 6, the ball screw support portion 203 is configured by fixing a cap 203B having a semicircular cross section support portion to a camshaft side support portion 203A formed on the upper portion of the camshaft support portion 202. Has been.
As shown in FIG. 7, on the outer peripheral surface of the ball screw 61, spiral screw threads 61A and 61B and spiral shaft screw grooves 61C and 61D are formed on the intake side and the exhaust side, respectively. The screw threads 61A and 61B and the shaft screw grooves 61C and 61D are set in different directions on the intake side and the exhaust side.

A sensor 80 that detects the rotation of the ball screw 61 is provided at the other end of the ball screw 61 on the intake side. The sensor 80 is fixed to a side wall portion located inside the V bank of the head cover 133A (133B). Thus, since the sensor 80 is arranged inside the V bank, the length of the engine 17 in the longitudinal direction of the vehicle body can be shortened, and the front bank 110A and the rear bank 110B (FIG. 2) are provided around the sensor 80. ).
The sensor 80 includes a rotating shaft 81 fixed to the other end of the ball screw 61, a fixed shaft 82 that is disposed substantially in parallel below the rotating shaft 81, and is a hexagon screw fixed to the ball screw support portion 203. It has. A driving gear 83 is formed on the outer peripheral surface of the rotating shaft 81, and a driven gear 84 that meshes with the driving gear 83 is formed on the fixed shaft 82. Therefore, when the ball screw 61 rotates, the rotation of the rotating shaft 81 that rotates integrally with the ball screw 61 is transmitted to the driven gear 84 via the drive gear 83. The sensor 80 detects the rotation amount of the ball screw 61 based on the rotation amount of the driven gear 84.

  The nut 62 has a through hole 62A through which the ball screw 61 passes. A spiral nut screw thread 62B corresponding to the screw threads 61A and 61B and shaft screw grooves 61C and D are formed on the inner peripheral surface of the through hole 62A. A spiral nut thread groove 62C corresponding to the above is formed. A plurality of rollable balls 65 are disposed between the nut screw groove 62C and the shaft screw grooves 61C and 61D. 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. And a link 63B.
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.

In FIG. 7, when the holder 53 swings in the directions of arrows P and Q, the position of the sub rocker arm support portion 59B of the link mechanism 56 shown in FIG. 5 is changed. By changing the position of the sub rocker arm support portion 59B, the valve cam 52 swings about the cam shaft 151 and is displaced in the circumferential direction with respect to the cam shaft 151. The phase of the direction, here the angular position or the circumferential position, is changed. Thus, by changing the circumferential position of the valve cam 52 with respect to the intake cam 153, the period during which the cam crest 52B of the valve cam 52 abuts on the roller 51C and the amount of depression can be changed, so the intake valve 147 The valve opening period and the lift amount can be changed.
For example, when the ball screw 61 rotates and the nut 62 is moved to the center side of the ball screw 61, and the holder 53 is further swung in the clockwise direction in FIG. Is rotated clockwise by the link mechanism 56. When the camshaft 151 is rotated in this state, the cam peak portion 52B depresses the roller 51C and the depressing amount increases, and the intake valve 147 opens and lifts. The amount increases.

Next, the intake port 145 and its periphery will be described. The vicinity of the intake port 145 is clearly shown in FIGS. 3, 9, and 10.
As shown in FIG. 3, each intake port 145 is connected to a lower intake port 145B provided integrally with the cylinder heads 132A and 132B and an upper end portion 145D of the lower intake port 145B separately from the cylinder heads 132A and 132B. And an upper intake port 145C. The upper intake port 145C is fixed to the lower intake port 145B by a bolt (not shown), and extends at a different angle in a direction approaching the head covers 133A and 133B. The injector 143 is provided below the lower intake port 145B and along the lower intake port 145B.
The upper intake ports 145C of the banks 110A and 110B extend upward substantially parallel to each other, and an intake chamber 43 disposed inside the V bank is connected to the upper end portion 145E of each upper intake port 145C. The intake chamber 43 functions as a calming tank that suppresses intake pulsation by making the cross-sectional area of the intake passage larger than the intake port 145 and the intake passage of the throttle body 42.

The throttle body 42 is provided on the right side of the vehicle body inside the V bank. As shown in FIG. 9, the center line C1 extending in the left-right direction of the vehicle body has a center line C1 far from the throttle body 42. In FIG. 9, they are arranged offset to the left side). The throttle body 42 employs TBW (throttle-by-wire) that changes the opening of the throttle by driving the actuator 42A.
The intake chamber 43 is formed in a tank shape and includes a substantially circular connection port 44 connected to the throttle body 42 on the right side of the vehicle body.
A pair of substantially circular through holes 45A and 45B are formed on the lower surface of the intake chamber 43, and upper end portions 145E of the upper intake ports 145C are connected to the through holes 45A and 45B. In the intake chamber 43, an intake passage 43A in which intake air flows from the connection port 44 to the through hole 45A along the arrow D and an intake passage 43B in which intake air flows from the connection port 44 to the through hole 45B along the arrow E are formed. Will be.

  The center of the through hole 45A is provided on the cylinder center line CA of the front bank 110A and in front of the vehicle body of the connection port 44. For this reason, the intake passage 43A is formed to be curved from the connection port 44 toward the front of the vehicle body. On the other hand, the through hole 45B is provided with its center disposed on the cylinder center line CB of the rear bank 110B and within the range W in the vehicle body longitudinal direction of the connection port 44. Therefore, the intake passage 43B is formed substantially straight from the connection port 44 toward the left side of the vehicle body. These intake passages 43A and 43B are formed to have substantially the same length. Therefore, the offset amount of the throttle body 42 is set so that the intake passages 43A and 43B have the same length.

Next, the fuel supply device will be described.
As shown in FIG. 10, the fuel supply device 90 includes a fuel pump 144 (FIG. 2), a fuel pipe 144A, a fuel chamber 91 connected to the downstream end of the fuel pipe 144A, a fuel chamber 91, and an injector 143. Are provided with fuel pipes 92 and 93, and an injector 143. Further, the fuel chamber 91, the fuel pipes 92 and 93, and the injector 143 are provided inside the V bank between the front bank 110A and the rear bank 110B.

The lower end portion 91B of the fuel chamber 91 is provided with a branch portion 96 that communicates with the pressure accumulation chamber and protrudes in the front-rear direction.
A front side attaching part 97 to which the fuel pipe 92 is connected and a rear side attaching part 98 to which the fuel pipe 93 is connected are provided on the surface facing the V bank inside of the branch part 96, and the fuel in the pressure accumulating chamber is provided. Branches at a branching portion 96 and flows downstream. Here, the fuel pipe 92 is a pipe connected to the injector 143A attached to the cylinder head 132A, and the fuel pipe 93 is a pipe connected to the injector 143B attached to the cylinder head 132B.

  The front attachment portion 97 and the rear attachment portion 98 are formed in a pipe shape protruding toward the injectors 143A and 143B, and attachment nut portions 97A and 98A are provided at the ends thereof. Further, the front attachment portion 97 and the rear attachment portion 98 are provided with a space therebetween in the vehicle front-rear direction, and extend substantially horizontally and parallel to each other. The fuel pipes 92 and 93 are easily attached and detached by rotating the attachment nut portions 97A and 98A with a tool or the like while being inserted into the attachment nut portions 97A and 98A.

The injectors 143A and 143B are positioned below the intake chamber 43 in the middle portion in the width direction inside the V bank. In the vehicle width direction, the injectors 143A and 143B are the same as the plug holes 142A provided with the spark plug 142 (see FIG. 2) In the position. Each of the injectors 143A and 143B has a fixing portion 170A protruding from the outer periphery of the cylindrical injector body 170 in two circumferential directions. The injectors 143A and 143B are inserted into an injector insertion portion (not shown) formed below the lower intake port 145B (see FIG. 3), and cylinders are inserted by a plurality of injector fixing bolts 170B penetrating the fixing portion 170A. It is fixed to the heads 132A and 132B.
At the upper part of the injectors 143A and 143B, injector-side mounting nut portions 172 and 173 projecting toward the fuel chamber 91 are provided.
Injector side mounting nut portions 172 and 173 are connecting portions to which fuel pipes 92 and 93 are connected, respectively. The fuel pipes 92 and 93 are attached and detached by rotating the injector-side mounting nut portions 172 and 173 while being inserted into the injector-side mounting nut portions 172 and 173.

Next, the operation of the engine 17 will be described.
Since the 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, the upper intake port 145C is connected to the cylinder head 132A, It can be removed from 132B, and operations such as attachment and removal of the injector 143 become possible. As a result, the injector 143 can be provided inside the V bank even when the bank angle is narrow. Further, since the upper intake port 145C is attached at a different angle in the direction approaching the head covers 133A and 133B, the space between the banks can be increased, and the work such as attachment and removal of the upper intake port 145C is facilitated. .

  Since the injector 143 is provided below the lower intake port 145B, the injector 143 is disposed on the intake port 145 side and lying on the cylinder axis C, and the ignition performance and the like of the engine 17 are improved. In addition, since the injector 143 is provided along the lower intake port 145B, the injector 143 can be prevented from protruding from the banks 110A and 110B, and the banks 110A and 110B can be downsized. As a result, the space between the banks can be increased, and operations such as attachment and removal of the injector 143 are facilitated.

In the lower intake port 145B formed in the cylinder heads 132A and 132B, manufacturing errors and assembly errors of parts may occur, and it is difficult to connect the pair of front and rear lower intake ports 145B and the intake chamber 43. There is a case.
In the present embodiment, each intake port 145 includes an upper intake port 145C that is separate from the cylinder heads 132A and 132B. Therefore, a difference in length is set in one of the pair of front and rear upper intake ports 145C, and an appropriate amount corresponding to the error is set. By using the upper intake port 145 </ b> C having a sufficient length, it is possible to suppress a gap or stress generated on the mating surface between the pair of front and rear upper intake ports 145 </ b> C and the intake chamber 43.

  Since the pair of front and rear upper intake ports 145C extend upward substantially in parallel with each other, the pair of front and rear upper intake ports extends from the lower intake port so as to be orthogonal to each other without changing the angle. The upper end portion 145E of the port 145C is located in the upper portion inside the V bank having a larger space. Therefore, even if the bank angle is narrow, the intake chamber 43 having a larger volume than the pair of front and rear intake ports 145 can be easily arranged.

  As described above, according to the present embodiment, the intake port 145 includes the lower intake port 145B integrated with the cylinder heads 132A and 132B, and the upper end of the lower intake port 145B, which is separate from the cylinder heads 132A and 132B. And an upper intake port 145C connected to 145D. As a result, the upper intake port 145C can be removed from the cylinder heads 132A and 132B, so that the injector 143 can be attached and removed even when the bank angle is narrow. As a result, the injector 143 can be placed at the optimum position. It can be provided inside a certain V bank. Further, the upper intake port 145C extends at a different angle in the direction close to the head covers 133A and 133B of the cylinder heads 132A and 132B, so that the space between the banks can be increased, and the upper intake port 145C can be attached. Work such as removal becomes easy.

  Further, according to the above embodiment, the upper intake ports 145C of the pair of front and rear banks 110A, 110B extend upward substantially in parallel with each other, and are arranged on the inner side of the V bank at the upper end portion 145E of each upper intake port 145C. An intake chamber 43 was connected. Accordingly, the upper end portion 145E of the upper intake port 145C connecting the intake chamber 43 is located on the inner upper side of the V bank having a larger space, so that the intake chamber 43 can be easily disposed even if the bank angle is narrow. Further, by setting a difference in length in one of the pair of front and rear upper intake ports 145C, it is possible to suppress a gap and stress generated on the mating surface between the pair of front and rear upper intake ports 145C and the intake chamber 43.

  Furthermore, according to the above-described embodiment, since the injector 143 is provided below the lower intake port 145B, the injector 143 is disposed on the intake port 145 side and lying on the cylinder axis C. Etc. are improved. Further, since the injector 143 is provided along the lower intake port 145B, the injector 143 can be prevented from protruding from the banks 110A and 110B, and the banks 110A and 110B can be downsized. As a result, the space between the banks can be increased, and operations such as attachment and removal of the injector 143 are facilitated.

FIG. 11 shows another embodiment. The same parts as those in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted.
In the present embodiment, a part of the upper intake port 300 of the front bank 110A is formed of an elastic member. More specifically, the upper intake port 300 is divided into two parts in the vertical direction, the upper side is a flange 301 connected to the lower surface of the intake chamber 43, and the lower side is intake air connected to the upper end 145D of the lower intake port 145B. A pipe 302 is provided. The flange 301 and the intake pipe 302 are formed using a metal material such as aluminum, for example. An elastic body 303 is provided between the flange 301 and the intake pipe 302.
The elastic body 303 is formed by baking an elastic member such as rubber on the surfaces of the flange 301 and the intake pipe 302. The elastic body 303 includes a substantially annular base portion 303A that couples the intake pipe 302 and the flange 301, and an extension portion 303B that extends from the base portion 303A along the outer peripheral surface of the intake pipe 302. The extending portion 303B that covers the outer peripheral surface of the intake pipe 302 may be omitted.

  Intake air amount sensors 310 and 311 for measuring the amount of air flowing into the combustion chamber 140 through the intake air port 145 can be attached to the upper intake air ports 300 and 145C, respectively. The intake air amount sensors 310 and 311 each include a plate-like sensor unit 312 and a sensor base 313 to which a base end of the sensor unit 312 is fixed. Each sensor base 313 is formed with a substantially circular engaging portion 313A and a plurality (two in the present embodiment) of fixing holes 313B in a side view. The intake air amount sensors 310 and 311 are hot-wire type flow rate sensors, which detect a change in the electrical resistance of the sensor unit 312 when the heat of the sensor unit 312 is taken away by the air flowing around the sensor unit 312, and the flow rate. It is a sensor that measures

  Sensor attachment holes 306 are formed on the side surfaces of the upper intake ports 300 and 145C so as to penetrate the side surfaces and communicate with the intake passage. The sensor attachment hole 306 of the upper intake port 300 passes through both the extension portion 303 </ b> B and the intake pipe 302. The intake air amount sensors 310 and 311 are inserted into the sensor mounting hole 306 from the outside of the upper intake ports 300 and 145C, and the bolts (non-removable) inserted into the fixing hole 313B in a state where the engaging portion 313A is engaged with the sensor mounting hole 306. (Shown). In this manner, since the intake air amount sensors 310 and 311 are provided independently for the pair of front and rear intake ports 145, the intake air amount flowing through the pair of front and rear intake ports 145 differs depending on the influence of disturbance and the difference in the shape of the flow path. Even so, the amount of intake air flowing into each combustion chamber 140 can be accurately measured.

Next, the operation of the present embodiment will be described.
Since the elastic body 303 formed of an elastic member is provided in the upper intake port 300 of the front bank 110A, the elastic body 303 is elastically deformed, whereby the angular tolerances of the banks 110A and 110B, the cylinder blocks 131A and 131B, and the cylinder head 132A. , 132B due to dimensional tolerances and the like, it is possible to more absorb the step and angular deviation of the mating surface between the pair of front and rear intake ports 145 and the intake chamber 43. Moreover, since the elastic body 303 is formed between the flange 301 and the intake pipe 302 of the upper intake port 300 that is divided into the upper and lower parts, the upper intake port is formed by the elastic deformation of the base portion 303A of the elastic body 303 in the vertical direction. The upper and lower lengths of 300 can be easily adjusted. As a result, the stress applied to the pair of front and rear intake ports 145 and the intake chamber 43 can be further suppressed, the sealing performance is improved, the output characteristics are deteriorated by sucking fresh air from the gap, and the fuel efficiency and exhaust performance are deteriorated. Can be prevented. Further, since the length of the upper intake port 300 can be adjusted, the length of the intake port 145 that leads from the intake chamber 43 to the combustion chambers 140 of the front and rear banks 110A, 110B can be made substantially the same.

In addition, since the elastic body 303 is provided in the upper intake port 300 having a relatively simple structure, the elastic body 303 can be easily formed as compared with the case where the elastic body is provided in the intake chamber 43 and the lower intake port 145B having a relatively complicated structure. In addition, the structure of the intake chamber 43 and the lower intake port 145B can be prevented from becoming more complicated.
Furthermore, since only the elastic body 303 of the upper intake port 300 is formed of an elastic member, for example, by forming the flange 301 and the intake pipe 302 using a rigid material such as a metal material, the weight of the intake chamber 43 and the intake negative pressure can be reduced. The endurance can be secured.

  According to the present embodiment, since a part (elastic body 303) of the upper intake port 300 of the front bank 110A is formed of an elastic member, the elastic member is elastically deformed, whereby the pair of front and rear intake ports 145 and the intake chamber 43 are elastically deformed. Therefore, the stress applied to the mating surface can be further suppressed, and the sealing performance can be improved. Further, since only the elastic body 303 of the upper intake port 300 is formed of an elastic member, the rigidity required for the upper intake port 300 can be ensured.

  Since the elastic body 303 is formed by dividing the upper intake port 300 into two parts in the vertical direction, the vertical length of the upper intake port 300 can be easily adjusted by elastically deforming the elastic body 303 in the vertical direction. The stress applied to the surface can be further suppressed and the sealing performance can be improved.

  Since the elastic body 303 is formed by baking rubber on the surfaces of the metal intake pipe 302 and the flange 301, the elastic body 303 is integrated with the upper intake port 300 which is divided into two parts. The upper intake port 300 can be easily attached and removed.

However, the above embodiment is an aspect of the present invention, and it is needless to say that the embodiment can be appropriately changed without departing from the gist of the present invention.
For example, in the above embodiment, the upper intake port 300 is configured to include the flange 301 on the upper side and the intake pipe 302 on the lower side, but may be configured to include the intake pipe on the upper side and the flange on the lower side.
In the above embodiment, only the elastic body 303 of the upper intake port 300 is formed of an elastic member, but the entire upper intake port may be formed of an elastic member.

In the above embodiment, an elastic member is used for the intake port 145 provided with the intake air amount sensor 310. However, as shown in FIG. 3, an elastic member is used for the intake port 145 where the intake air amount sensor 310 is not provided. May be.
In the above embodiment, an elastic member is used for the upper intake port 300 of the front bank 110A. However, an elastic member may be used for the upper intake port of the rear bank 110B.
In the above embodiment, the engine 17 is a V-type two-cylinder water-cooled engine. However, the present invention is not limited to this, and in a V-type engine having three or more cylinders, the upper intake port 145C and An intake port 145 having a lower intake port 145B and an intake port 145 having an upper intake port 300 and a lower intake port 145B may be provided.

17 Engine (V-type internal combustion engine)
43 Intake chamber 110A, 110B Bank 132A, 132B Cylinder head 133A, 133B Head cover 143 Injector (fuel injection device)
145 Intake port 145B Lower intake port 145C, 300 Upper intake port 301 Flange 302 Intake pipe 303 Elastic body

Claims (5)

Includes a V-type arrangement with a pair of front and rear banks (110A, 110B), the front and rear banks (110A, 110B) V bank inside the longitudinal banks (110A, 110B) of the V-type internal combustion provided with an intake port (145, 145) of In the institution
The intake port (145, 145) is a cylinder head (132A, 132B) an integral lower intake port (145B, 145B) and said cylinder head (132A, 132B) and separately, the lower intake port (145B, 145B) and an upper intake port (145C, 145C) connected to the upper end of
The upper intake port (145C, 145C) extends at a different angle in a direction close to the head cover (133A, 133B) of the cylinder head (132A, 132B) ,
The upper intake ports (145C, 145C) of the pair of front and rear banks (110A, 110B) extend upward substantially parallel to each other and are arranged at the upper ends of the upper intake ports (145C, 145C) inside the V bank. The V-type internal combustion engine is characterized in that the intake chamber (43) is connected and one upper intake port (145C, 145C) of the front and rear banks (110A, 110B) is formed of an elastic member . The V-type internal combustion engine according to claim 1, wherein at least a part of one upper intake port (145C ) of one of the front and rear banks (110A, 110B) is formed of an elastic member. The V-type internal combustion engine according to claim 2 , wherein the elastic member is formed by dividing the upper intake port (145) into two vertically and between them. The V-type internal combustion engine according to claim 3 , wherein the elastic member is formed by baking rubber on a metal surface.   The upper intake port (145C) has an upper side flange (301) connected to the lower surface of the intake chamber (43) and a lower side intake pipe (145C) connected to the upper end of the lower intake port (145B). 302), and the elastic body (303) is formed by baking an elastic member such as rubber on the surface of the flange (301) and the intake pipe (302), and the intake pipe (302) and the flange ( 301) and a substantially annular base portion (303A), and an extension portion (303B) extending from the base portion (303A) along the outer peripheral surface of the intake pipe (302). The V-type internal combustion engine according to claim 4.

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