CN1111642C - V-shape internal combustion engine for motor bike - Google Patents

Abstract

In a V-shaped internal combustion engine for a two-wheeled vehicle, by rationally arranging the lubricating oil pump and the cooling water pump, the overall size of the machine can be suppressed, and the rear of the crankcase can be downsized to secure the rear of the crankcase and the rear exhaust pipe. There is a sufficient interval between them to reduce the influence of the heat dissipation of the exhaust pipe on the crankcase. The lubricating oil pump (57) for supplying oil to the lubricating parts of the front and rear units (4 ₁ , 4 ₂ ), and the water cooling jackets (24 1 , 4 ₂ ) for the front and rear units (4 ₁ , 4 ₂ ) 24 ₂ ) The cooling water pump (62) for supplying cooling water is arranged above the front of the crankshaft (15), which can realize the miniaturization of the rear part of the crankcase 21 and ensure a sufficient distance between the rear part of the crankcase and the rear exhaust pipe .

Description

V-shaped internal combustion engines for two-wheeled motor vehicles

The invention relates to a V-shaped internal combustion engine for a two-wheeled motor vehicle. In particular it relates to improvements to internal combustion engines described below. The internal combustion engine has a front unit and a rear unit in a state mounted on a vehicle frame. The front unit and the rear unit are opened in a V-shape front and rear about a crankshaft arranged in a left-right direction. At the rear of the crankcase that accommodates the crankshaft, the transmission unit that accommodates the transmission is integrally connected, the front exhaust pipe is connected to the front of the front unit, and the rear exhaust pipe is connected to the rear of the rear unit. Tube.

The aforementioned V-shaped internal combustion engine for a motorcycle is disclosed in, for example, Japanese Unexamined Patent Application Publication No. Sho 58-96130.

In the conventional V-shaped internal combustion engine for motorcycles, the lubricating oil pump and the cooling water pump are arranged vertically at the rear of the crankcase, so the rear of the crankcase had to be formed deep.

In this way, the rear of the crankcase is very close to the rear exhaust pipe connected to the rear of the rear unit, and is easily affected by the heat dissipation of the exhaust pipe.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a V-shaped internal combustion engine for a motorcycle in which an increase in the size of the entire engine can be suppressed by rationally arranging a lubricating oil pump and a cooling water pump. Make the structure of the rear part of the crankcase compact, and ensure that there is a sufficient interval between the rear part of the crankshaft and the rear exhaust pipe, so that the influence of the heat dissipation of the exhaust pipe on the crankcase can be reduced.

In order to achieve the above object, the V-shaped internal combustion engine for a two-wheeled motor vehicle according to the first characteristic of the present invention has a front unit and a rear unit in a state where it is mounted on the vehicle frame. The crankshaft arranged in the direction is the center, and the front and rear are opened in a V shape. The transmission part housing the transmission is integrally connected to the rear of the crankcase housing the crankshaft, the front exhaust pipe is connected to the front of the front unit, and the rear exhaust pipe is connected to the rear of the rear unit. , which is characterized in that the lubricating oil pump supplying oil to the lubricating parts of the front and rear units, and the cooling water pump supplying cooling water to the water cooling jackets of the front and rear units are arranged on the left and right in front of the crankshaft ground on the crankcase.

According to the first feature, since the oil pump and the water pump are arranged at the upper front of the crankshaft, the rear part of the crankcase can be compactly formed without interfering with the two pumps at all. Therefore, a sufficient distance can be ensured between the crankcase rear and the rear exhaust pipe, and the influence of heat radiation from the exhaust pipe on the crankcase can be reduced.

Furthermore, due to the arrangement of the two pumps, although the front portion of the crankcase has a somewhat bulging shape, the bulging portion is disposed in the empty space below the front unit, so that the size of the internal combustion engine E will not be increased.

The second feature of the present invention is to add the following feature on the basis of the above-mentioned first feature, that is, relative to the front unit, the adjacent distance between the rear unit and the connecting rods of the two units is offset in the left and right direction on one side of the rear unit; on the opposite side of the offset direction of the rear unit relative to the front unit, the exhaust muffler is arranged on the side of the rear wheel, and on the rear side of the rear unit, on the side of the exhaust muffler, The outlet of the exhaust port of the unit is provided, and the rear exhaust pipe connected with the exhaust muffler is connected at the outlet.

According to the second feature, the bending portion of the rear exhaust pipe can be reduced, the pipe resistance thereof can be reduced, and the output performance can be improved.

The third feature of the present invention is to add the following feature on the basis of the first or second feature, that is, on the end of the crankshaft opposite to the exhaust muffler, the front part and the rear part are adjacently connected. Timing transmissions, the front and rear timing transmissions drive the camshafts for the movable valves of the front and rear units respectively.

According to the third feature, the rear exhaust pipe can be arranged compactly without any interference with the front and rear timing transmissions.

The fourth feature of the present invention is to add the following feature to the first or second feature, that is, the side wall of the transmission part on the side of the rear timing transmission is closer to the exhaust muffler side than the rear timing transmission. is biased.

According to the fourth feature, by slightly offsetting the crankcase body part and the transmission part in the left and right direction, even if the caster angle of the rear unit is not particularly set to be small, the adjustment lever for the chain tensioner and the transmission part can be adjusted. mounted on the rear wall of the rear unit without interference.

The fifth feature of the present invention is to add the following feature to the third feature, that is, the side wall of the transmission part on the rear timing gear side is biased closer to the exhaust muffler side than the rear timing gear. set aside.

According to the fifth feature, by slightly offsetting the crankcase body part and the transmission part in the left-right direction, even if the caster angle of the rear unit is not particularly set to be small, the adjustment lever for the chain tensioner and the transmission part can be aligned. mounted on the rear wall of the rear unit without interference.

The sixth feature of the present invention is to add the following feature to the first or second feature, that is, the input shaft and the output shaft of the transmission are arranged behind the crankshaft front and back, and at the same time, the upper wall of the transmission part that houses them formed into a flat shape.

According to the sixth feature, a sufficient distance can be ensured between the transmission unit and the rear exhaust pipe, and the influence of heat radiation from the exhaust pipe on the transmission unit can be reduced.

The seventh feature of the present invention is to add the following feature to the third feature, that is, the input shaft and the output shaft of the transmission are arranged behind the crankshaft in a front and back direction, and at the same time, the upper wall of the transmission part that accommodates them is formed as Flat shape.

According to the seventh feature, a sufficient distance can be ensured between the transmission unit and the rear exhaust pipe, and the influence of heat radiation from the exhaust pipe on the transmission unit can be reduced.

The eighth feature of the present invention is to add the following feature to the fourth feature, that is, the input shaft and the output shaft of the transmission are arranged behind the crankshaft in a front and rear direction, and at the same time, the upper wall of the transmission part that accommodates them is formed as Flat shape.

According to the eighth feature, a sufficient distance can be secured between the transmission unit and the rear exhaust pipe, and the influence of heat radiation from the exhaust pipe on the transmission unit can be reduced.

Fig. 1 is a side view of a motorized two-wheeled vehicle equipped with a V-shaped internal combustion engine of the present invention.

Fig. 2 is a side view of the above internal combustion engine.

Fig. 3 is an enlarged longitudinal sectional view taken along line 3-3 in Fig. 2 .

Fig. 4 is a sectional view along line 4-4 in Fig. 3 .

Fig. 5 is a sectional view along line 5-5 in Fig. 2 .

Fig. 6 is a diagram of the cooling water system of the above-mentioned internal combustion engine.

Fig. 7 is a sectional view along line 7-7 in Fig. 2 .

FIG. 8 is an enlarged view around the front and rear timing transmissions of FIG. 3 .

FIG. 9 is an enlarged view around the transmission of FIG. 3 .

Fig. 10 is a plan view of the periphery of the exhaust system of the above-mentioned internal combustion engine.

Fig. 11 is a top view of the cylinder head of the rear unit of the above-mentioned internal combustion engine.

Fig. 12 is a view from direction 12 in Fig. 9 .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a side view of a two-wheeled motor vehicle equipped with a V-shaped internal combustion engine of the present invention. Fig. 2 is a side view of the above internal combustion engine. Fig. 3 is an enlarged longitudinal sectional view taken along line 3-3 in Fig. 2 . Fig. 4 is a sectional view along line 4-4 in Fig. 3 . Fig. 5 is a sectional view along line 5-5 in Fig. 2 . Fig. 6 is a diagram of the cooling water system of the above-mentioned internal combustion engine. Fig. 7 is a sectional view along line 7-7 in Fig. 2 . FIG. 8 is an enlarged view around the front and rear timing transmissions of FIG. 3 . FIG. 9 is an enlarged view around the transmission in FIG. 3 . Fig. 10 is a plan view of the periphery of the exhaust system of the above-mentioned internal combustion engine. Fig. 11 is a top view of the cylinder head of the rear unit of the above-mentioned internal combustion engine. Fig. 12 is a view from direction 12 in Fig. 9 .

In the following description, front and rear and left and right are based on the vehicle body of the motorcycle.

[The overall structure of the two-wheeled motor vehicle (see Figure 1, Figure 2)]

At the front end of the vehicle frame 1 of the motorcycle M, steerable front forks (both not shown) for supporting the front wheels are connected. A rear fork 3 supporting a rear wheel 2 is connected to a rear portion of the vehicle frame 1 to swing up and down, and a rear shock absorber 7 is interposed between the rear fork 3 and each rear end of the vehicle frame 1 .

A V-shaped internal combustion engine E having front and rear units 4 ₁ , 4 ₂ is mounted in the middle of the vehicle frame 1, and a fuel tank 5 is installed above it. On the rear portion of the vehicle frame 1, a main seat 6a and a rear seat 6b are attached continuously to the rear end of the fuel tank 5. As shown in FIG.

The chain drive 10 is disposed on the left side of the rear wheel 2 , and is connected between the output shaft 97 of the transmission 8 connected to the internal combustion engine E and the hub of the rear wheel 2 . The starter motor 11 is arranged in front and below the crankshaft 15 .

At the valley 28 between the front and rear units 4 ₁ , 4 ₂ of the internal combustion engine E, there are front and rear gasifiers 12 ₁ , 12 ₂ connected to the corresponding units. The front exhaust pipe 13 ₁ and the rear exhaust pipe 13 _{2 are respectively connected to the front of the front unit 4 1 and the rear of the rear unit 4 2 ,} and the front exhaust pipe 13 ₁ and the rear exhaust pipe 13 ₁ The pipes ₁₃₂ are assembled at the front end of a common exhaust muffler 14 disposed on the opposite side to the chain transmission 10 , that is, on the right side of the rear wheel 2 , with the rear wheel 2 sandwiched therebetween.

[The overall structure of the internal combustion engine (see Figure 2, Figure 3, Figure 5, Figure 8)]

The front unit 4 ₁ and the rear unit 4 ₂ of the internal combustion engine E are arranged front and rear with a gap of 90° around the crankshaft 15 arranged in the left-right direction. The crankshaft 15 has a crank portion 16 and a pair of left and right journals 17 and 18 adjacent to both ends thereof, and the crank portion 16 has a crank pin 16a. The journals 17 , 18 are supported on the crankcase 21 via ball bearings 19 , 20 , respectively.

The front and rear units 4 ₁ , 4 ₂ are equipped with cylinder blocks 22 ₁ , 22 ₂ for engaging the crankshaft 15 on the front and rear slopes of the angular upper portion of the crankcase 21 and cylinder heads 23 ₁ , 23 ₂ respectively for engaging the upper ends thereof, On each of the cylinder blocks 22 ₁ , 22 ₂ and the cylinder heads 23 ₁ , 23 ₂ , communicating water cooling jackets 24 ₁ , 24 ₂ are formed.

Pistons 26 ₁ , 26 ₂ fitted in cylinder bores 25 ₁ , 25 ₂ of cylinder blocks 22 ₁ , 22 ₂ are connected to crankpin 16 a via connecting rods 27 ₁ , 27 ₂ . At this time, the connecting rod ₂₇₂ of the rear unit ₄₂ is arranged adjacent to the left of the connecting rod ₂₇₁ of the front unit ₄₁ on the crank pin 16a, and is offset from the left-right direction of these connecting rods ₂₇₁ , ₂₇₂ . The amount S ( FIG. 8 ) corresponds to the offset of the axis of the rear unit ₄₂ to the left relative to the axis of the front unit ₄₁ .

As shown in Figure 5, on the right end portion of the crankshaft 15 protruding outward from the right journal 18, the overrunning clutch 53 of the starting transmission 94 and the primary transmission 54 connected to the clutch 100 are installed sequentially from the inner side thereof. drive gears 54a, and they are arranged adjacent to each other. At this time, the outer part of the overrunning clutch 53 is splined with the crankshaft 15, and the starter gear 52 is fixedly installed on its inner part. The drive gear 54a is keyed to the crankshaft 15 .

As shown in Figure 8, on the left end portion that stretches outward from the left journal 17 of the crankshaft 15, the front portion timing drive for driving the movable valve camshaft 41 ₁ of the front unit 4 ₁ is installed sequentially from its inner side. The drive timing sprocket 42 ₁ of the device 46 ₁ , the drive timing sprocket 42 2 of _the rear timing drive 46 _{2 for driving the valve camshaft 41 2 of} the rear unit 4 ₂ and the rotor 31 of the generator 30, and They are arranged adjacent to each other. At this time, the rotor 31 is keyed to the crankshaft 15 . The installation structure of the two driving timing sprockets 42 ₁ , 42 ₂ will be described below.

The stator 32 of the generator 30 surrounded by the rotor 31 is fixed to the inner wall of the left side cover 33 which is engaged with the left end surface of the crankcase 21 .

A protrusion 35 is formed at a position on the outer peripheral surface of the rotor 31 , and a crankshaft position sensor 36 that detects the rotational position of the crankshaft 15 in cooperation with the protrusion is fixed to the left end surface of the crankcase 21 . The output signal of the crankshaft position sensor 36 is used as an ignition control signal and as an input signal for a tachometer.

On the right end portion of the crankshaft 15 opposite to the generator 30, a starter gear 52 is supported by an overrunning clutch 53 adjacent to the right journal 18, and a primary drive gear is keyed adjacent to the starter gear 52. 54a.

According to the above structure, the front and rear timing actuators 46 ₁ , 46 ₂ can be assembled together on the left end side of the crankshaft 15, and the assemblability is good. In addition, when performing maintenance of the front and rear timing transmissions 46 ₁ , 46 ₂ , as long as the generator 30 outside them is removed from the crankshaft 15 , maintenance can be easily performed without any interference with other components. Moreover, since the two timing transmissions 46 ₁ and 46 2 of the generator 30 are arranged adjacent to each other, the oil droplets scattered from the two timing transmissions 46 ₁ and _{46 2 splash} on the generator 30 during driving, which can effectively cool it down.

In addition, since the front and rear timing transmissions 46 ₁ , 46 ₂ and the generator 30 are arranged on the left side of the crankcase 21, the starting transmission 94, the primary transmission 54 and the clutch are arranged on the other side. 100, therefore, the weight balance of both sides of the crankcase 21 is good, and therefore, when loaded on the vehicle frame 1, the left and right weights of the motorcycle M are easily balanced.

[Moving valve system (see Figure 2 to Figure 4, Figure 8, Figure 9)]

In the cylinder head 23 ₁ , 23 ₂ of each unit 4 ₁ , 4 ₂ , there are suction valves 37 ₁ , 37 ₂ and exhaust valves 38 ₁ , 38 ₂ , and the suction valves 37 ₁ , 37 ₂ are close to the two units 4 ₁ , 4 ₂ between the valley portion 28 side is set. In addition, in each of the cylinder heads 23 ₁ , 23 ₂ , both ends of the camshafts 41 ₁ , 41 ₂ are supported by ball bearings 50 , 50 ′, respectively. The camshafts 41 ₁ , 41 ₂ are parallel to the crankshaft 15 and pass through The rocker arms 39 ₁ , 39 ₂ , 40 ₁ , 40 ₂ open and close to drive the corresponding suction and exhaust valves 37 ₁ , 37 ₂ , 38 ₁ , 38 ₂ . Timing chains 44 ₁ , 44 ₂ are wound around driving timing sprockets 42 ₁ , 42 ₂ and driven timing sprockets 43 ₁ , 43 ₂ . The driving timing sprocket 42 ₁ , 42 ₂ is fixed on the left end of the crankshaft 15, and the passive timing sprocket 43 ₁ , 43 ₂ is fixed on the left end of the camshaft 41 ₁ , 41 ₂ of each unit 4 ₁ , 4 ₂ . The two drive timing sprockets 42 ₁ , 42 ₂ are provided with a common hub 45 which is pressed in adjacent to the outer end of the left journal 17 of the crankshaft 15 .

The driving timing sprocket 42 ₁ , timing chain 44 ₁ and passive timing sprocket 43 ₁ of the front unit _{4 1} constitute a front timing transmission 46 ₁ which decelerates the rotation of the crankshaft 15 by 1/ 2 to the corresponding camshaft 41 ₁ . It is disposed in a front timing transmission chamber ₄₇₁ of the front unit ₄₁ formed on a side wall on the generator 30 side. The driving timing sprocket 42 ₂ , timing chain 44 ₂ and passive timing sprocket 43 ₂ of the rear unit 4 ₂ constitute a rear timing transmission _{46 2} which decelerates the rotation of the crankshaft 15 by 1/ 2 to the corresponding camshaft 41 ₂ . It is disposed in the rear timing transmission chamber ₄₇₂ of the rear unit ₄₂ formed on the side wall of the generator 30.

At this time, the rear timing transmission 46 ₂ is arranged on the outside of the front timing transmission 46 ₁ in the axial direction, that is, on the side of the generator 30 .

The crankshaft 15 rotates counterclockwise as indicated by the arrow R in FIG. 4 , so the rear side of each timing chain 44 ₁ , 44 ₂ becomes the slack side. To apply some tension to these slack sides, on the slack side of each timing chain 44 ₁ , 44 ₂ slidably abuts arcuate chain tensioners 48 ₁ , 48 ₂ , which chain tensioners 48 ₁ , 48 ₂ can It is pivotally supported on the crankcase 21 . The known tensioner adjusting rods 49 ₁ , 49 ₂ are respectively installed on the mounting surfaces behind the cylinder blocks 22 ₁ , 22 ₂ of the units 4 ₁ , 4 ₂ with bolts 109 . The tensioner adjustment levers 49 ₁ , 49 ₂ press the longitudinal middle portions of the chain tensioners 48 ₁ , 48 ₂ toward the corresponding timing chains 44 ₁ , 44 ₂ with a constant load.

The crankcase 21 is divided into a left half-case 21a and a right half-case 21b at its left-right central part, and the outer rings of the above-mentioned ball bearings 19, 20 are pre-press-fitted on the left and right half-cases, and the left and right half-cases When 21a and 21b are combined, the left and right journals 17 and 18 of the crankshaft 15 are respectively lightly pressed into the inner rings of the above-mentioned ball bearings 19 and 20. 45 The drive timing sprocket 42 ₁ , 42 ₂ pressed into the crankshaft 15 can pass through the inner ring of the left ball bearing 19, and the outer diameter d1 of the drive timing sprocket 42 ₁ , 42 ₂ is set to be slightly smaller than the inner diameter of the ball bearing 19. Circle inner diameter d2. Therefore, when the crankshaft 15 is a single body, the hub 45 of the two drive timing sprockets 42 ₁ , 42 ₂ can be press-fitted, and this press-fitting operation can be easily performed. In addition, by lightly pressing the ball bearings 19, 20 into the left and right half-cases 21a, 21b and the left and right crankshaft journals 17, 18, the vibration of the ball bearings 19, 20 can be suppressed during machine operation and noise can be reduced.

[Exhaust system (see Figure 2, Figure 10 and Figure 11)]

The outlet of the exhaust port ₅₁₁ of the front unit ₄₁ has an opening in the front of its cylinder head ₂₃₁ , and is connected with the upstream end of the front exhaust pipe ₁₃₁ here. The outlet of the exhaust port ₅₁₂ of the rear unit ₄₂ has an opening on the right side of the cylinder head ₂₃₂ rear portion, opposite to the rear timing transmission device ₄₆₂ , and is connected to the rear portion. The upstream end of the exhaust pipe 13 ₂ .

Both the front exhaust pipe 13 ₁ and the rear exhaust pipe 13 ₂ are arranged on the opposite side of the front and rear chain transmissions 46 ₁ , 46 ₂ and on the right side of the internal combustion engine E, arranged side by side up and down, and The downstream ends are assembled and connected to the exhaust muffler 14 disposed on the right side of the rear wheel 2 .

On one side of the above-mentioned internal combustion engine E where the rear unit ₄₂ is biased relative to the front unit ₄₁ , the front and rear timing transmission devices 46 ₁ and 46 ₂ are collectively arranged. On the other hand, On the other side of the internal combustion engine, the front and rear exhaust pipes 13 ₁ , 13 ₂ are collectively arranged side by side up and down, so that the two timing drives 46 ₁ , 46 ₂ and the two exhaust pipes 13 ₁ , 13 can be avoided. ₂ , the overall width of the internal combustion engine E including the two exhaust pipes 13 ₁ and 13 ₂ can be narrowed as much as possible.

The rear exhaust pipe 13 ₂ arranged on the right side of the motorcycle M is connected to the exhaust port 51 ₂ opened on the rear right side of the cylinder head 23 ₂ of the rear unit 4 ₂ , so that the The curved portion of the rear exhaust pipe ₁₃₂ is defined, thereby reducing its pipeline resistance and improving output performance.

[Drive system (see Figure 2, Figure 3 and Figure 9)]

On the crankcase 21, a gearbox part 95 protruding from the bottom of the rear unit ₄₂ is integrally formed. In the gearbox part 95, an input shaft 96 and an output shaft 97 of the transmission 8 are accommodated. The input shaft 96 And output shaft 97 is in the rear of crankshaft 15 and is parallel with it, side by side front and rear. Both ends of these are supported on the left and right side walls of the transmission unit 95 through a pair of ball bearings 98, 98', 99, 99', respectively. The inner part 101 of the clutch 100 is spline-coupled to the right end of the input shaft 96, and the clutch 100 is covered by the right side cover 34 engaged on the right side of the crankcase 21, and installed at the inner end of the outer part 102 of the clutch 100. The primary driven gear 54b is engaged with the above-mentioned primary driving gear 54a to form the primary transmission device 54 . Between the input shaft 96 and the output shaft 97, several stages (five stages in the figure) of speed change gear sets G1-G5 are selectively arranged.

The left side wall 95a (see FIG. 9 ) of the gearbox part 95 supporting the input shaft 96 and the left end of the output shaft 97 is offset to the right of the timing transmission device ₄₆₂ of the rear unit ₄₂ . Therefore, when the tensioner adjusting lever ₄₉₂ in the timing transmission ₄₆₂ of the rear unit ₄₂ is installed behind the cylinder block ₂₂₂ of the rear unit ₄₂ , interference with the transmission part 95 can be avoided.

Since the timing transmission device ₄₆₂ of the rear unit ₄₂ is arranged on the outside of the timing transmission device ₄₆₁ of the front unit ₄₁ , i.e., on the left side, the transmission part 95 can be positioned to the right with respect to the crankcase 21. The offset amount is minimized, and the internal combustion engine E can be downsized.

[Vehicle speed sensor (see Figure 2, Figure 9 and Figure 12)]

A mounting hole 103 is provided on the rear wall of the transmission part 95 , and the vehicle speed sensor 105 is fixed on the rear wall of the transmission part 95 with bolts 110 . The detecting portion 105 a of the vehicle speed sensor 105 protrudes into the transmission portion 95 through the mounting hole 103 . The detection unit 105a of the vehicle speed sensor 105 is arranged to face the last driven gear, that is, the tooth tip of the driven gear 104 of the final gear set G5.

The final driven gear 104 is spline-fitted on the output shaft 97, and doubles as a shift gear for establishing the second-speed gear set G2 by shifting to the left. By shifting this gear, the outer periphery of the gear does not come out of the vehicle speed sensor 105. detection area. The vehicle speed sensor 105 outputs a signal corresponding to the number of teeth of the last gear driven gear 104 that crosses the front of the detecting portion to a computer not shown in the figure, and the vehicle speed is calculated based on the input signal in the computer. displayed on the speedometer (not shown) on the instrument panel shown.

In this way, the vehicle speed sensor 105 detects the number of rotations of the last gear driven gear 104 that is constantly rotating together with the output shaft 97 as the vehicle speed. The rear portion 4 ₂ tilted backward toward the gearbox portion 95 interferes with and does not interfere with the rear exhaust pipe 13 ₂ mounted on the rear portion thereof.

A rib 106 covering the underside of the vehicle speed sensor 105 is integrally formed on the rear surface of the transmission part 95 , and a through hole 107 through which a wire 108 of the vehicle speed sensor 105 passes is drilled in the center of the rib 106 .

As shown in FIG. 2 , a pair of left and right hangers 112 ₁ , 112 2 are integrally protruded from the back of the gearbox portion 95 , and a left and right hanger 112 ₂ is integrally protruded on the front of the crankcase 21 . The hanger portions 112 ₃ are _coupled to _the vehicle _frame 1 when the internal combustion engine E is mounted on the vehicle frame 1 . The vehicle speed sensor 105 is arranged in the free space behind the transmission unit 95 surrounded by the two sets of hanger parts 112 ₁ and 112 ₂ at the rear, so that the space utilization rate can be improved.

The ribs 106 function to protect the vehicle speed sensor 105 from sand and the like flying from below when the motorcycle M is running. In addition, the through hole 107 of the lead wire 108 also functions as a discharge port for discharging rainwater and washing water that have entered the rib 106 .

[Lubrication system and cooling system (see Figure 2, Figure 3, Figure 5 and Figure 6)]

As shown in FIG. 2, FIG. 3 and FIG. 5, the pump driving gear 56 and the primary driven gear 54b are engaged with the primary driving gear 54a keyed to the right end of the crankshaft 15 at two positions different in the circumferential direction.

The pump drive gear 56 is keyed to the pump shaft 61 , and the pump shaft 61 is supported via a bearing 86 by the right side cover 34 joined to the right end surface of the crankcase 21 . The pump shaft 61 is parallel to the crankshaft 15 and arranged in front of the crankshaft 15 .

The inner rotor 58 of the trochoidal oil pump 57 for lubrication is fixed at the inner end of the pump shaft 61 , and the impeller 63 of the cooling water pump 62 is fixed at the outer end. A pump housing 60 housing the outer rotor 59 of the oil pump 57 is screwed to a partition wall 65 of the crankcase 21 that supports the ball bearing 20 . The pump casing 64 housing the impeller 63 is fixed to the outer surface of the right side cover with bolts 87 . In this way, the oil pump 57 and the water pump 62 are arranged coaxially above and in front of the crankshaft 15 . In addition, the oil pump 57 is provided in the crankcase 21 adjacent to the outside of the overrunning clutch 53 in the radial direction.

The suction port of the oil pump 57 is connected to a strainer 67 through an upper suction pipe 68, and the strainer 67 is arranged in an oil storage portion 66 at the bottom of the crankcase 21 (FIG. 2). The discharge port communicates with lubricating parts of the crankshaft 15 and the camshafts 41 ₁ , 41 ₂ of the units 4 ₁ , 4 ₂ and other lubricating parts through the oil supply passage 69 .

In the middle of the oil supply passage 69, an oil filter 70 located approximately directly above the crankshaft 15 is provided. The oil filter 70 is installed in a filter chamber 71 formed on the right side cover 34 , and a cover 72 for closing the opening of the chamber 71 is fixed to the right side cover 34 . In the filter chamber 71 , an inlet chamber 71 a on the outer peripheral side of the oil filter 70 communicates with the discharge port of the oil pump 57 through the upstream portion 69 a of the oil supply passage 69 formed in the crankcase 21 . In addition, the outlet chamber 71b on the inner peripheral side of the oil filter 70 communicates with the two branch oil passages 69a and 69c of the oil supply passage 69 formed on the cover 72 . One branch oil passage 69b communicates with the lubricating part 73 of the crankshaft 15 system, and the other branch oil passage 69c branches into front and rear branch oil passages 69d and 69e at the joint surface of the crankcase 21 and the right side cover 34, and includes the front part It communicates with the lubricating parts _{74 1} , 74 ₂ of the movable valve systems of the respective camshafts 41 ₁ , 41 ₂ of the rear units 4 1 , 4 ₂ .

Therefore, when the oil pump 57 is driven by the rotation of the crankshaft 15 through the pump drive gear 56 and the pump shaft 61, the oil in the oil storage part 66 is sucked up from the coarse filter 67 and then pressed to the filter chamber 71, and is absorbed by the oil filter 70. After filtering, it is supplied to the lubricating part 73 of the crankshaft 15 system and the lubricating parts 74 ₁ and 74 ₂ of the movable valve systems of the units 4 ₁ and 4 ₂ to lubricate them. Moreover, due to the above-mentioned disposition and structure of the oil pump 57, the filter chamber 71, the oil filter 70 and the oil supply passage 69, the length of the oil supply passage 69 can be shortened as much as possible, and the lubrication of the front and rear units 4 ₁ , 4 ₂ can be shortened as much as possible. The system has a slightly symmetrical structure, and the two units 4 ₁ , 4 ₂ can be lubricated equally.

The oil filter 70 is provided with a safety valve 70b which short-circuits between the inlet chamber 71a and the outlet chamber 71b when the filter element 70a is clogged.

In the water pump 62, as shown in FIG. 6, its suction pipe 75 is connected to the outlet of the radiator 29 (as shown in FIG. ₁ , arranged in front of the internal combustion engine E) through a water pipe 771, and the discharge pipe 76 is connected to the outlet of the radiator 29 through a water pipe ₇₇₂ . The lower part of the water cooling jacket ₂₄₁ of the front unit ₄₁ is connected.

As mentioned above, the front and rear units 4 ₁ , 4 ₂ are equipped with connected water cooling jackets 24 1 _, 24 ₂ on the respective cylinder blocks 22 ₁ , 22 ₂ and cylinder heads 23 ₁ , 23 ₂ . In addition, in the cylinder head ₂₃₂ of the rear unit ₄₂ , a confluence chamber 80 opening toward the front is formed, and the upper part of the water cooling jacket ₂₄₂ communicates with the confluence chamber 80.

On the opposite surfaces of the front and rear units 4 ₁ , 4 _{2 ,} lower joints 78 ₁ , 78 ₂ communicating with the lower parts of the corresponding water-cooling jackets 24 ₁ , 24 ₂ are protruded integrally. These joints 78 ₁ , 78 ₂ is connected with the two ends that are arranged in the bottom communicating water pipe 77 ₃ of valley portion 28.

At the rear of the front unit 4 ₁ , an upper joint 79 ₁ communicating with the upper portion of its water cooling jacket 23 ₁ is integrally formed. Below the cylinder head 23 ₂ of the rear unit 4 ₂ , the flange of the upper joint 79 2 communicated with the confluence chamber 80 is fixed with screws, and the two ends of the water pipe _{77 4 at} the rear of the valley 28 are connected to these upper joints. 79 ₁ and 79 ₂ are connected.

A thermostat 82 is provided in the confluence chamber 80 , and a thermostat cover 81 holding the thermostat 82 and covering the opening of the confluence chamber 80 is joined to the front surface of the cylinder head ₂₃₂ .

An outlet connector 83 communicating with the outlet of the thermostat 82 is integrally formed on the thermostat cover 81 , and the outlet connector 83 is connected to the inlet of the radiator 29 through the water pipe ₇₇₅ .

A bypass outlet joint 84 is integrally formed on the upper joint ₇₉₂ , and the bypass outlet joint 84 communicates with the confluence chamber 80 through a communication path 84'. The bypass outlet joint 84 communicates with the heating chamber of the gasifier ₁₂₂ of the rear unit ₄₂ , the heating chamber of the gasifier ₁₂₁ of the front unit ₄₁ , and the suction pipe 75 in sequence through a bypass water pipe 85. The diameter of the bypass outlet connection 84 is much smaller than the outlet connection 83 of the thermostat cover 81 .

When the temperature of the water in the confluence chamber 80 falls below a predetermined temperature, the thermostat 82 blocks the connection between the confluence chamber 80 and the thermostat cover 81 , and simultaneously opens the communication path 84 ′ between the confluence chamber 80 and the bypass outlet joint 84 . When the water temperature becomes higher than a predetermined temperature, the thermostat 82 communicates between the confluence chamber 80 and the thermostat cover 81, and closes the communication path 84'.

Therefore, with the rotation of the crankshaft 15, when the water pump 62 is driven by the pump drive gear 56 and the pump shaft 61, if the water temperature in the confluence chamber 80 is relatively low, the thermostat 82 will block the confluence chamber 80 and the thermostat cover 81, At the same time, the communication path 84' is opened, so the cooling water is first sent from the discharge pipe 76 to the water cooling jacket 24 ₁ of the front unit 4 ₁ by means of the water pump 62, and then half of the cooling water is directly moved to the rear via the lower communication pipe 77 ₃ The water cooling jacket 24 ₂ of the external unit 4 ₂ . The cooling water that has passed through _the water cooling jacket ₂₄₁ of the front unit ₄₁ moves to the confluence chamber 80 of the rear unit ₄₂ after passing through the upper connecting water pipe 774, and passes through the cooling water of the water cooling jacket ₂₄₂ of the rear unit ₄₂ . The water merges and flows from the confluence chamber 80 through the communication path 84', then comes out from the bypass outlet joint 84, then passes through the heating chamber of the rear vaporizer ₁₂₂ and the front vaporizer ₁₂₁ in turn, and returns to the suction pipe 75 of the water pump 62 , repeating the same cycle thereafter, since the cooling water does not circulate through the radiator 29, the warm-up of the internal combustion engine E is promoted, and at the same time, the carburetors 12 ₁ and 12 ₂ are heated to prevent ice formation around their fuel nozzles.

As the internal combustion engine E warms up, when the temperature of the cooling water that passes through the water cooling jackets 24 ₁ and 24 ₂ of the two units 4 ₁ and 4 ₂ in the confluence chamber 80 exceeds a specified value, the thermostat 82 will set the temperature of the confluence chamber 80 It communicates with the thermostat cover 81 and closes the communication path 84 ′ at the same time, so the cooling water flows to the outlet joint 83 side, passes through the radiator 29 and returns to the suction pipe 75 of the water pump 62 . Since the same cycle is repeated thereafter, the two units 4 ₁ , 4 ₂ can be effectively cooled by the cooling water cooled by the heat dissipation effect of the radiator 29 .

The lower and upper connecting water pipes 77 ₃ and 77 ₄ are relatively short, because they can be arranged in the valley between the two units 4 ₁ and 4 ₂ , concealed between the two units 4 ₁ and 4 ₂ , are not conspicuous, and do not damage the internal combustion engine E Appearance.

The thermostat 82 is set in the confluence chamber 80 where the cooling water of the front and rear units 4 ₁ and 4 ₂ merge. Therefore, the thermostat 82 can actually sense the average water temperature of the two units 4 ₁ and 4 ₂ , and can adjust the temperature of the two units. Units 4 ₁ , 4 ₂ perform proper water temperature control. Furthermore, piping to the thermostat 82 is unnecessary, and piping can be simplified.

Because the thermostat cover 81 is joined to the upper front of the rear unit ₄₂ , the thermostat cover 81 is equipped with an outlet connector 83 protruding forward, so the water pipe ₇₇₅ communicating the outlet connector 83 with the inlet of the radiator 29 With less bending, the flow path resistance can be reduced and the appearance can be improved.

Since on the upper joint ₇₉₂ of the rear unit ₄₂ , a bypass outlet joint 84 that is smaller than its diameter and communicated with the confluence chamber 80 is integrally formed, so the rear of the upper joint ₇₉₂ and the bypass outlet joint 84 The installation on the external unit 4 ₂ can be carried out together. Piping work can be simplified.

In addition, since the oil pump 57 and the water pump 62 are arranged coaxially, and these pumps are driven by the common pump shaft 61 driven by the primary drive gear 54a, the driving system of these pumps can be simplified.

Furthermore, since the oil pump 57 is arranged radially adjacent to the overrunning clutch 53 and also because the oil pump 57 and the water pump 62 are coaxially arranged, an increase in the lateral width of the internal combustion engine E can be suppressed.

Since the oil pump 57 and the water pump 62 are arranged in front of and above the crankshaft 15, the rear part of the crankcase 21 and the transmission part 95 connected thereto can be formed into a compact structure without interference with the oil pump 57 and the water pump 62 at all. The height of the internal combustion engine E from the ground can be ensured, and the heights of the passenger seats 6a, 6b can be easily lowered. At this time, through the above arrangement of the oil pump 57 and the water pump 62, even if the front portion of the crankcase 21 is slightly bulged, the bulged portion is absorbed by the dead space below the front unit ₄₁ , so that the internal combustion engine E is not hindered. miniaturization.

Moreover, the drive system of the two pumps 57 and 62 occupying the position above the crankshaft 15 can avoid being immersed in the oil of the oil storage part 66, so the drive system does not stir the oil, which contributes to reducing power loss.

In addition, the input shaft 96 and output shaft 97 of the transmission 8 are arranged horizontally behind the crankshaft 15 without any interference with the above-mentioned oil pump 57 and water pump 62, so that the size of the transmission unit 95 can be reduced, and the upper wall can be formed as In this way, the distance between the transmission part 95 and the rear exhaust pipe ₁₃₂ can be sufficiently ensured, and the transmission from the rear exhaust pipe ₁₃₂ to the transmission part 95 and the transmission part 95 accommodated therein can be easily avoided. Machine 8 produces thermal influence.

[Starting system (see Figure 2 and Figure 7)]

A housing recess 88 is formed on the front bottom surface of the crankcase 21 , and the starter motor 11 is disposed therein. The axis of the starter motor 11 is parallel to the crankshaft 15 . In the case 89 of the starter motor 11, the cylindrical support portion 89a at one end is liquid-tightly fitted in the through hole 90 formed in the end wall of the receiving recess 88, and the mounting arm portion 89b at the other end is Fasten on the crankcase 21 with bolt 111, like this, starter motor 11 is installed on the crankcase 21. The front end of the rotary shaft 91 of the starter motor 11 extends into the crankcase 21 , and a pinion 92 formed on the front end thereof drives the starter gear 52 through a reduction gear set 93 . The starting gear 52 , the overrunning clutch 53 and the reduction gear set 93 constitute a starting transmission 94 , and the starting transmission 94 communicates between the starter motor 11 and the crankshaft 15 .

As mentioned above, since the starter motor 11 is disposed in the front and lower side of the crankshaft 15, the starter motor 11 does not hinder the miniaturization of the rear part of the crankcase 21 and the transmission part 95. The dead space absorbs, therefore, the miniaturization of the internal combustion engine E is not hindered. In addition, through the above-mentioned configuration of the starter motor 11, although the reduction gear set 93 is immersed in the oil in the oil storage portion 66 at the bottom of the crankcase 21, it only operates when the machine is started and does not operate when the machine is running, so it will not Agitates the oil so that no loss of power results.

The present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the gist thereof.

According to the first feature of the present invention, since the lubricating oil pumps that supply oil to the lubricating parts of the front and rear units and the cooling water pumps that supply cooling water to the water cooling jackets of the front and rear units are located in front of the crankshaft Since they are disposed on the crankcase horizontally, the rear part of the crankcase can be compactly formed without interfering with the two pumps at all. Therefore, a sufficient distance can be ensured between the crankcase rear and the rear exhaust pipe, and the influence of heat radiation from the exhaust pipe on the crankcase can be reduced. Furthermore, due to the arrangement of the two pumps, although the front part of the crankcase has a somewhat bulging shape, the bulging part is arranged in the empty space below the front unit, so that the size of the internal combustion engine E is not increased.

According to the second feature of the present invention, since the adjacent intervals between the rear unit and the connecting rods of the two units are correspondingly offset on one side in the left and right direction relative to the front unit; On the opposite side of the installation direction, arrange the exhaust muffler on the side of the rear wheel; on the rear of the rear unit, on the side of the exhaust muffler, open the exhaust outlet of the unit, because the outlet is connected to the The rear exhaust pipe connected to the exhaust muffler, therefore, can reduce the bending part of the rear exhaust pipe, reduce its pipeline resistance, and improve output performance.

According to the third feature of the present invention, since the front and rear timing transmissions are connected adjacent to one end of the crankshaft opposite to the exhaust muffler, the front and rear timing transmissions drive the front and rear timing transmissions, respectively. The camshafts are used for the movable valves of the front and rear units, so the rear exhaust pipe can be arranged compactly without any interference with the front and rear timing transmissions.

According to the fourth feature of the present invention, since the side wall of the transmission part on the rear timing gear side is biased closer to the exhaust muffler side than the rear timing gear, by placing the crankcase body part It is slightly offset from the transmission unit in the left and right direction, and the chain tensioner adjustment lever can be installed on the rear wall of the rear unit without interfering with the transmission unit, even if the caster angle of the rear unit is not particularly set small. superior.

According to the fifth feature of the present invention, since the input shaft and the output shaft of the transmission are disposed behind the crankshaft front and rear, and at the same time, the upper wall of the transmission part housing them is formed into a flat shape, so the transmission part and the transmission part can be ensured. There is sufficient space between the rear exhaust pipes to reduce the influence of the heat dissipation of the exhaust pipes on the transmission unit.

Claims (8)

1. A V-shaped internal combustion engine for a two-wheeled motor vehicle, in the state of being mounted on the vehicle frame (1), has a front unit (4 ₁ ) and a rear unit (4 ₂ ), the front unit (4 ₁ ) and The rear unit (4 ₂ ) is centered on the crankshaft (15) arranged in the left-right direction, and is opened in a V-shape front and rear, and the rear part of the crankcase (21) for accommodating the crankshaft (15) is integrally connected to accommodate the transmission. The gearbox part (95) of (8) is connected to the front exhaust pipe (13 ₁ ) at the front of the front unit (4 1 ), and is connected to the rear exhaust pipe (13 ₁ ) at the rear of the rear unit (4 ₂ ). exhaust pipe (13 ₂ ), characterized in that, The lubricating oil pump (57) that supplies oil to the lubricating parts of the front and rear units (4 ₁ , 4 ₂ ), and the water cooling jackets (24 ₁ , 24 ₂ ) to the front and rear units (4 ₁ , 4 _{2 )} ) A cooling water pump (62) for supplying cooling water is disposed on the crankcase (21) on the front and upper side of the crankshaft (15) on the left and right sides. 2. The V-shaped internal combustion engine for two-wheeled motor vehicle according to claim 1, characterized in that it corresponds to the adjacent interval (S) of the connecting rods (27 ₁ , 27 ₂ ) of the two sets (4 ₁ , 4 ₂ ) The rear unit (4 ₂ ) is biased on one side of the left and right direction relative to the front unit (4 ₁ ), and on the opposite side of the bias direction of the rear unit (4 ₁ ) relative to the front unit (4 ₁ ) The exhaust muffler (14) is arranged on one side of the rear wheel (2), and on the side of the rear unit (4 ₂ ) on the side of the exhaust muffler (14) is set the unit (4 ₂ ) The outlet of the exhaust port (51 ₂ ), where the rear exhaust pipe (13 ₂ ) connected to the exhaust muffler (14) is connected. 3. The V-shaped internal combustion engine for two-wheeled motor vehicle according to claim 1 or 2, characterized in that, on the end of the crankshaft (15) opposite to the exhaust muffler (14), a Front and rear timing transmissions (46 ₁ , 46 ₂ ), _which drive the valves of the front and rear units ( _{4 1 ,} 4 ₂ ), respectively Use the camshafts (41 ₁ , 41 ₂ ). 4. The V-shaped internal combustion engine for motor two-wheeled vehicles as claimed in claim 1 or 2, characterized in that, the side wall (95a) of the gearbox portion (95) and the rear timing transmission device (46 ₂ ) side is larger than the rear side wall (95a) The external timing drive (46 ₂ ) is biased more towards the side of the exhaust muffler (14). 5. The V-type internal combustion engine for motor two-wheeled vehicle as claimed in claim 3, characterized in that, the side wall (95a) of the gearbox portion (95) and the rear timing transmission device (46 ₂ ) side is more timing than the rear timing. The transmission ( 46 ₂ ) is biased more towards the exhaust muffler ( 14 ) side. 6. The V-type internal combustion engine for motor two-wheel vehicles as claimed in claim 1 or 2, characterized in that, the input shaft (96) and the output shaft (97) of the speed changer (8) are configured in the rear of the crankshaft (15) front and rear , At the same time, the upper wall of the gearbox part (95) that houses them is formed into a flat shape. 7. The V-type internal combustion engine for motor two-wheel vehicles as claimed in claim 3, wherein the input shaft (96) and the output shaft (97) of the speed changer (8) are configured in the rear of the crankshaft (15) front and back, and simultaneously , the upper wall of the gearbox part (95) that accommodates them is formed in a flat shape. 8. The V-type internal combustion engine for motor two-wheel vehicles as claimed in claim 4, characterized in that, the input shaft (96) and the output shaft (97) of the speed changer (8) are configured in the rear of the crankshaft (15) front and back, and simultaneously , the upper wall of the gearbox part (95) that accommodates them is formed in a flat shape.

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