JP3954732B2 - V-type internal combustion engine for motorcycles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a V-type internal combustion engine for a motorcycle, and in particular, has a front bank and a rear bank that are opened in a front-rear V shape around a crankshaft arranged in a left-right direction when mounted on a body frame. The transmission case is accommodated integrally with the rear of the crankcase for accommodating the crankshaft, the front exhaust pipe is provided at the front of the front bank, and the rear exhaust pipe is provided at the rear of the rear bank. It is related with improvement of what connected each.
[0002]
[Prior art]
  Such a V-type internal combustion engine for a motorcycle is known, for example, as disclosed in Japanese Patent Application Laid-Open No. 58-96130.
[0003]
[Problems to be solved by the invention]
  In such a conventional V-type internal combustion engine for a motorcycle, since the lubricating oil pump and the cooling water pump are arranged vertically at the rear part of the crankcase, the rear part of the crankcase must be formed deeply.
[0004]
  However, in such a case, the rear part of the crankcase is close to the rear exhaust pipe connected to the rear part of the rear bank, and is easily affected by the radiant heat of the exhaust pipe.
[0005]
  The present invention has been made in view of such circumstances, and the rational arrangement of the lubricating oil pump and the cooling water pump enables the rear case of the crankcase to be made compact while suppressing an increase in the size of the entire engine. An object of the present invention is to provide the V-type internal combustion engine for a motorcycle, which can secure a sufficient distance between the rear part of the crankcase and the rear exhaust pipe and reduce the influence of the radiant heat of the exhaust pipe on the crankcase. And
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention has a front bank and a rear bank that are open in a front-rear V shape around a crankshaft arranged in the left-right direction when mounted on a body frame. The transmission case is housed in one piece at the rear of the crankcase that houses the shaft, and the front exhaust pipe is connected to the front of the front bank, and the rear exhaust pipe is connected to the rear of the rear bank. V-type internal combustion engine for motorcyclesBecauseA lubricating oil pump for supplying oil to the lubricating parts of the front and rear banks, and a cooling water pump for supplying cooling water to the water jackets of the front and rear banksThe crankshaft on one end side of the crankshaft is provided with an overrunning clutch and a primary drive gear of a starting transmission device, which are sequentially attached to one end portion of the crankshaft from the inside thereof, and the primary drive gear. A pump drive gear that is formed in a large diameter and meshes with the primary drive gear, a pump shaft that couples the pump drive gear and is disposed in front of and above the crankshaft and extends parallel to the crankshaft, and the pump shaft An oil pump that is driven at the inner end of the overrunning clutch and disposed adjacent to the outer side in the radial direction of the overrunning clutch, and that is driven at the outer end of the pump shaft and disposed on the opposite side of the oil pump across the pump drive gear The water pump and both pumpsAbove and in front of the crankshaftCoaxialPlaced inRuThis is the first feature.
[0007]
  According to the first feature, since the oil pump and the water pump are arranged in front of and above the crankshaft, the rear portion of the crankcase can be formed compactly without being interfered with the two pumps. Therefore, a sufficient interval between the rear portion of the crankcase and the rear exhaust pipe can be ensured, and the influence of the radiant heat of the exhaust pipe on the crankcase can be reduced.Further, since the oil pump and the water pump are arranged on the same axis and are driven by the common pump shaft driven from the primary drive gear, the drive system can be simplified. In addition, since the oil pump is disposed adjacent to the overrunning clutch in the radial direction, an increase in the lateral width of the internal combustion engine can be suppressed even by the coaxial arrangement of the oil pump and the water pump.
[0008]
  In addition to the above features, the present inventionAn oil filter connected to the discharge port of the oil pump is disposed between the front and rear banks substantially above the crankshaft.A V-type internal combustion engine for a motorcycle having the second feature.
[0009]
  In addition to the first or second feature, the present invention further provides a crankshaft.otherA third feature is that the front and rear timing transmissions for driving the valve camshafts of the front and rear banks are connected to the end adjacent to each other.
[0010]
  According to the third feature, the rear exhaust pipe can be arranged in a compact manner without any interference with the front and rear timing transmission devices..
[0011]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.
[0012]
  1 is a side view of a motorcycle equipped with a V-type internal combustion engine of the present invention, FIG. 2 is a side view of the internal combustion engine, FIG. 3 is a sectional view taken along line 3-3 in FIG. 2, and FIG. 4 is a sectional view taken along line 5-5 of FIG. 2, FIG. 6 is a cooling water system diagram of the internal combustion engine, FIG. 7 is a sectional view taken along line 7-7 of FIG. 2, and FIG. FIG. 9 is an enlarged view around the transmission of FIG. 3, FIG. 10 is a plan view around the exhaust system of the internal combustion engine, and FIG. 11 is a plan view of the cylinder head of the rear bank. 12 is a view taken in the direction of arrow 12 in FIG.
[0013]
  In the description, front and rear and left and right are based on the motorcycle body.
[Overall configuration of motorcycle (see FIGS. 1 and 2)]
  A front fork (both not shown) that supports the front wheels is connected to the front end of the body frame 1 of the motorcycle M so as to be steerable. A rear fork 3 that supports the rear wheel 2 is connected to the rear portion of the vehicle body frame 1 so as to swing up and down, and a rear cushion 7 is interposed between the rear fork 3 and the rear end portions of the vehicle body frame 1. .
[0014]
  In the middle part of the body frame 1, there are front and rear banks 4₁, 4₂Is mounted, and a fuel tank 5 is attached above the V-type internal combustion engine E. Further, a main seat 6 a and a pillion seat 6 b are attached to the rear portion of the vehicle body frame 1 so as to be continuous with the rear end of the fuel tank 5.
[0015]
  The chain transmission 10 that connects the output shaft 97 of the transmission 8 connected to the internal combustion engine E and the hub of the rear wheel 2 is disposed on the left side of the rear wheel 2. The starter motor 11 is disposed in front of and below the crankshaft 15.
[0016]
  Front and rear banks 4 of the internal combustion engine E₁, 4₂Between the valleys 28 are the front and rear vaporizers 12 connected to the corresponding banks.₁, 12₂Is disposed. Front bank 4₁Front and rear bank 4₂Front exhaust pipe 13 connected to the rear part respectively₁And rear exhaust pipe 13₂Are collectively connected to the front end of a common exhaust muffler 14 disposed on the opposite side of the chain transmission 10 across the rear wheel 2, that is, on the right side of the rear wheel 2.
[Overall configuration of internal combustion engine (see FIGS. 2, 3, 5, 8)]
  Front bank 4 of internal combustion engine E₁And rear bank 4₂Are arranged 90 ° around the crankshaft 15 arranged in the left-right direction and arranged in the front-rear direction. The crankshaft 15 includes a single crank portion 16 having a crankpin 16a and a pair of left and right journals 17 and 18 adjacent to both ends thereof, and the journals 17 and 18 have ball bearings 19 and 20, respectively. Via the crankcase 21.
[0017]
  Front and rear bank 4₁, 4₂The cylinder block 22 joins the crankshaft 15 to the front and rear slopes of the upper portion of the mountain shape of the crankcase 21.₁, 22₂And cylinder heads 23 joined to the upper ends thereof.₁, 23₂Each cylinder block 22₁, 22₂And cylinder head 23₁, 23₂In the series of water jackets 24₁, 24₂Is formed.
[0018]
  Each cylinder block 22₁, 22₂Cylinder bore 25₁, 25₂Piston 26 fitted in₁, 26₂Is connecting rod 27₁, 27₂And connected to the crank pin 16a. At that time, rear bank 4₂The connecting rod 27₂The front bank 4 on the crankpin 16a₁The connecting rod 27₁Are arranged adjacent to the left of these connecting rods 27₁, 27₂Corresponding to the horizontal offset amount S (FIG. 8) of the rear bank 4₂Is the front bank 4₁Offset to the left with respect to the axis.
[0019]
  As shown in FIG. 5, the right end of the crankshaft 15 that projects outward from the right journal 18 has an overrunning clutch 53 of the starting transmission 94 and a primary transmission 54 connected to the clutch 100 in order from the inside. A primary drive gear 54a is attached and arranged adjacent to each other. At this time, the outer member of the overrunning clutch 53 is splined to the crankshaft 15, and the starter gear 52 is fixed to the inner member. The primary drive gear 54a is key-coupled to the crankshaft 15.
[0020]
  Further, as shown in FIG. 8, the left end portion of the crankshaft 15 that protrudes outward from the left journal 17 has a front bank 4 in order from the inside.₁Valve camshaft 41₁Front timing transmission 46 for driving₁Drive timing sprocket 42₁, Rear bank 4₂Valve camshaft 41₂Rear timing transmission 46 for driving₂Drive timing sprocket 42₂And the rotor 31 of the generator 30 are mounted and arranged adjacent to each other. At that time, the rotor 31 is key-coupled to the crankshaft 15. Two drive timing sprockets 42₁, 42₂The mounting structure will be described later.
[0021]
  The stator 32 of the generator 30 surrounded by the rotor 31 is fixed to the inner wall of the left cover 33 joined to the left end surface of the crankcase 21.
[0022]
  A protrusion 35 is formed at a position on the outer peripheral surface of the rotor 31, and a crank position sensor 36 that detects the rotational position of the crankshaft 15 in cooperation with the protrusion 35 is fixed to the left end surface of the crankcase 21. The output signal of the crank position sensor 36 is used as a control signal for the ignition device and an input signal for the tachometer.
[0023]
  At the right end of the crankshaft 15 opposite to the generator 30, a start gear 52 is supported via an overrunning clutch 53 adjacent to the right journal 18, and further, the primary drive is adjacent to the start gear 52. The gear 54a is key-coupled.
[0024]
  When configured as described above, the front and rear timing transmissions 46 are provided on the left end side of the crankshaft 15.₁, 46₂Can be assembled at once, and their assemblability is improved. Also the front and rear timing transmission 46₁, 46₂When performing the maintenance, it is possible to easily perform the maintenance without interfering with anything else by simply removing only the generator 30 on the outside from the crankshaft 15. Moreover, both timing transmissions 46 of the generator 30₁, 46₂Due to the adjacent arrangement, both timing transmissions 46 are in operation.₁, 46₂Since the splashed oil splashes on the generator 30, it can be cooled effectively.
[0025]
  Further, the front and rear timing transmissions 46 are provided on the left side of the crankcase 21.₁, 46₂Since the starter transmission device 94, the primary transmission device 54, and the clutch 100 are disposed on the other side of the generator 30, the weight balance on both sides of the crankcase 21 is good, and therefore the vehicle body frame. When mounted on 1, the right and left weight balance of the motorcycle M can be easily achieved.
[Valve-operated system (see FIGS. 2 to 4, 8, 9)]
  Each bank 4₁, 4₂Cylinder head 23₁, 23₂Intake valve 37₁, 37₂And exhaust valve 38₁, 38₂However, the intake valve 37₁, 37₂Both banks 4₁, 4₂It is provided close to the valley portion 28 side. Each cylinder head 23₁, 23₂The corresponding intake and exhaust valve 37₁, 37₂; 38₁, 38₂Rocker arm 39₁, 39₂40₁, 40₂Cam shaft 41 that opens and closes via₁, 41₂Are supported by ball bearings 50 and 50 'in parallel with the crankshaft 15, respectively. Then, a drive timing sprocket 42 fixed to the left end portion of the crankshaft 15₁, 42₂And each bank 4₁, 4₂Camshaft 41₁, 41₂Driven sprocket 43 fixed to the left end of the₁, 43₂And timing chain 44₁44₂Is wrapped around. Both drive timing sprockets 42₁, 42₂Is provided with a common boss 45 press-fitted adjacent to the outer end of the left journal 17 of the crankshaft 15.
[0026]
  Thus, front bank 4₁Drive timing sprocket 42₁Timing chain 44₁And driven timing sprocket 43₁The corresponding camshaft 41 reduces the rotation of the crankshaft 15 to 1 every 2 minutes.₁Front timing transmission 46 to transmit to₁It consists of front bank 4₁The front timing transmission chamber 47 formed on the side wall of the generator 30 side₁Placed in. Rear bank 4₂Drive timing sprocket 42₂Timing chain 44₂And driven timing sprocket 43₂The corresponding camshaft 41 reduces the rotation of the crankshaft 15 to 1 every 2 minutes.₂Rear timing transmission 46 to transmit to₂Which also constitutes front bank 4₁The rear timing transmission chamber 47 formed on the side wall on the generator 30 side₂Placed in.
[0027]
  In so doing, the rear timing transmission 46₂The front timing transmission 46₁It is arranged more axially outside, that is, on the generator 30 side.
[0028]
  The crankshaft 15 rotates counterclockwise as indicated by an arrow R in FIG.₁44₂The back side is the slack side. In order to give a certain tension to the slack side, each timing chain 44₁44₂On the slack side, an arcuate chain tensioner 48 pivotally supported by the crankcase 21 is supported.₁, 48₂These chain tensioners 48 are slidably contacted.₁, 48₂Corresponding timing chain 44 in the longitudinal center₁44₂A known tensioner lifter 49 that presses with a constant load toward₁, 49₂Is each bank 4₁, 4₂Cylinder block 22₁, 22₂Each bolt 109 is attached to a mounting surface formed on the rear surface.
[0029]
  The crankcase 21 is divided into a left case half 21a and a right case half 21b at the left and right central portions thereof, and outer races of the ball bearings 19 and 20 are attached thereto by light press fitting in advance, and both case halves 21a. , 21b, the left and right journals 17, 18 of the crankshaft 15 are lightly press-fitted into the inner races of the ball bearings 19, 20, respectively. Drive timing sprocket 42 in which a boss 45 common to the shaft 15 is press-fitted₁, 42₂Drive timing sprocket 42 so that can pass through the inner race of the left ball bearing 19.₁, 42₂Outside diameter d₁Is the inner diameter d of the inner race of the ball bearing 19.₂Set slightly smaller. Therefore, when the crankshaft 15 is used alone, the double drive timing sprocket 42 is used.₁, 42₂The boss 45 can be press-fitted, and the press-fitting work can be easily performed. Further, the ball bearings 19 and 20 are lightly press-fitted into the left and right case halves 21a and 21b and the left and right crank journals 17 and 18, thereby suppressing vibration of the ball bearings 19 and 20 and reducing noise during engine operation. Can do.
[Exhaust system (see FIGS. 2, 10 and 11)]
  Front bank 4₁Exhaust port 51₁The outlet of the cylinder head 23₁The front exhaust pipe 13 is opened to the front of the front exhaust pipe 13.₁Are connected at their upstream ends. Rear bank 4₂Exhaust port 52₂The outlet of the cylinder head 23₂Rear, rear timing transmission 46₂Is opened on the right side opposite to the rear exhaust pipe 13.₂Are connected at their upstream ends.
[0030]
  Front exhaust pipe 13₁And rear exhaust pipe 13₂Are both front and rear chain transmissions 46.₁, 46₂The exhaust muffler 14 is arranged on the right side of the internal combustion engine E on the opposite side, and is connected to the exhaust muffler 14 arranged at the right side of the rear wheel 2 with the downstream ends assembled.
[0031]
  Thus, the front bank 4 of the internal combustion engine E as described above.₁Rear bank 4 against₂Front and rear timing transmissions 46 on one side of the offset direction side₁, 46₂While the front and rear exhaust pipes 13 are arranged on the other side of the internal combustion engine E.₁, 13₂Are arranged side by side and concentrated piping, so both timing transmissions 46₁, 46₂And both exhaust pipes 13₁, 13₂Both exhaust pipes 13 should be easily avoided.₁, 13₂The total width of the internal combustion engine E including can be reduced as much as possible.
[0032]
  Rear bank 4₂Cylinder head 23₂Exhaust port 51 opening on the right side of the rear part₂And a rear exhaust pipe 13 piped to the right side of the motorcycle M.₂The rear exhaust pipe 13₂It is possible to reduce the bent portion of the pipe, lower its pipe resistance, and contribute to improvement of output performance.
[Transmission system (see FIGS. 2, 3 and 9)]
  The crankcase 21 has a rear bank 4₂A transmission case 95 is formed integrally with the lower part of the transmission case 95. The transmission case 95 is provided with an input shaft 96 and an output shaft 97 of the transmission 8 that are arranged immediately after the crankshaft 15 and in parallel therewith. These two ends are supported on the left and right side walls of the mission case 95 via a pair of ball bearings 96, 97; 98, 99, respectively. An inner member 101 of the clutch 100 covered by a right cover 34 joined to the right side surface of the crankcase 21 is splined to the right end portion of the input shaft 96, and the primary member is connected to the inner end of the outer member 102. A primary driven gear 54b which is engaged with the drive gear 54a and constitutes the primary transmission 54 is attached. Between the input shaft 96 and the output shaft 97, a plurality of (in the illustrated example, five) transmission gear train G₁~ G_FiveAre arranged to be selectable.
[0033]
  The left side wall 95a (see FIG. 9) of the mission case portion 95 that supports the left end portions of the input shaft 96 and the output shaft 97 is provided on the rear bank 4.₂Timing transmission device 46₂It is formed so as to be offset to the right. Therefore, rear bank 4₂Timing transmission device 46₂Tensioner lifter 49₂Back bank 4₂Cylinder block 22₂When attached to the rear surface, interference with the mission case portion 95 can be avoided.
[0034]
  In particular, rear bank 4₂Timing transmission device 46₂The front bank 4₁Timing transmission device 46₁Since it is arranged further outward, that is, to the left, the amount of offset of the mission case portion 95 to the right of the crankcase 21 can be minimized and the internal combustion engine E can be made compact.
[Vehicle speed sensor (see FIGS. 2, 9 and 12)]
  A mounting hole 103 is provided in the rear wall of the mission case portion 95, and a vehicle speed sensor 105 that allows the detecting portion 105 a to enter the mission case portion 95 through the hole 103 is fixed to the rear wall of the mission case portion 95 with a bolt 110. This vehicle speed sensor 105 has its detection portion 105a as a top driven gear, that is, a top gear train G._FiveIt arrange | positions so as to oppose the tooth-tip of the driven gear 104 of this.
[0035]
  The top driven gear 104 is spline-fitted to the output shaft 97 and is shifted to the left by the second gear train G₂This shift also serves as a shift gear, so that the outer periphery of the gear does not deviate from the detection area of the vehicle speed sensor 105 even when the shift is performed. The vehicle speed sensor 105 outputs a signal corresponding to the number of teeth of the top driven gear 104 that passes immediately before the detection unit to a computer (not shown). The computer calculates the vehicle speed from the input signal, and Displayed on a speedometer (not shown) on an instrument panel (not shown).
[0036]
  Thus, the vehicle speed sensor 105 can be mounted on the rear wall of the transmission case portion 95 so that the vehicle speed sensor 105 that detects the rotational speed of the top driven gear 104 that always rotates together with the output shaft 97 as the vehicle speed. Rear bank 4 tilted backward to the side 95₂Of course, the rear exhaust pipe 13 is attached to the rear part.₂It can be done without any interruption.
[0037]
  A rib 106 that covers the lower surface of the vehicle speed sensor 105 is integrally formed on the rear surface of the transmission case portion 95, and a through hole 107 through which the lead wire 108 of the vehicle speed sensor 105 passes is formed in the center portion of the rib 106. .
[0038]
  Further, as shown in FIG. 2, a pair of left and right hanger portions 112 are arranged on the rear surface of the mission case portion 95.₁, 112₂However, a pair of left and right hangers 112 are disposed on the front surface of the crankcase 21._ThreeAre integrally protruded, and when the internal combustion engine E is mounted on the vehicle body frame 1, these hanger portions 112 are mounted.₁, 112₂, 112_ThreeIs coupled to the vehicle body frame 1. Hanger part 112 of two sets of rear parts₁, 112₂The vehicle speed sensor 105 is arranged by utilizing a dead space behind the mission case portion 95 surrounded by the space, thereby improving the space efficiency.
[0039]
  Thus, the rib 106 functions to protect the vehicle speed sensor 105 from gravel or the like flying from below during traveling of the motorcycle M, and the through hole 107 through which the lead wire 108 passes enters the rib 106. It also functions as an outlet for rainwater and washing water.
[Lubrication and cooling system (see FIGS. 2, 3, 5 and 6)]
  As shown in FIGS. 2, 3 and 5, the primary drive gear 54a key-coupled to the right end of the crankshaft 15 has a pump drive gear 56 and a primary driven gear 54b at two different locations in the circumferential direction. Meshed.
[0040]
  The pump drive gear 56 is key-coupled to a pump shaft 61 that is supported via a bearing 86 on the right cover 34 joined to the right end surface of the crankcase 21. The pump shaft 61 is arranged so that it is parallel to the crankshaft 15 and forward and upward.
[0041]
  An inner rotor 59 of a lubricating trochoid oil pump 57 is fixed to the inner end of the pump shaft 61, and an impeller 60 of a cooling water pump 62 is fixed to the outer end. The pump housing 60 that houses the outer rotor 59 of the oil pump 57 is screwed to the partition wall 65 of the crankcase 21 that supports the ball bearing 20. The pump casing 64 that houses the impeller 63 is fixed to the outer surface of the right cover with bolts 87. Thus, the oil pump 57 and the water pump 62 are coaxially disposed above and in front of the crankshaft 15, and the oil pump 57 is disposed adjacent to the outer side of the overrunning clutch 53 in the radial direction. The case 21 is provided.
[0042]
  The suction port of the oil pump 57 is connected to a strainer 67 (see FIG. 2) installed in the oil reservoir 66 at the bottom of the crankcase 21 via a suction pipe 68, and the discharge port is connected to an oil supply passage 69. Crankshaft 15 and each bank 4₁, 4₂Camshaft 41₁, 41₂It communicates with other lubrication parts.
[0043]
  In the middle of the oil supply passage 69, an oil filter 70 located approximately right above the crankshaft 15 is interposed. The oil filter 70 is attached to a filtration chamber 71 formed in the right cover 34, and a cap 72 that closes the opening of the chamber 71 is fixed to the right cover 34. In the filtration chamber 71, the inlet chamber 71 a on the outer peripheral side of the oil filter 70 communicates with the discharge port of the oil pump 57 via the upstream portion 69 a of the oil supply passage 69 formed in the crankcase 21. The peripheral outlet chamber 71b communicates with the two branch oil passages 69b and 69c of the oil supply passage 69 formed in the cap 72, and one branch oil passage 69b communicates with the lubricating portion 73 of the crankshaft 15 system. The other branch oil passage 69 c further branches into front and rear branch oil passages 69 d and 69 e at the joint surface of the crankcase 21 and the right cover 34, and the front and rear banks 4.₁, 4₂Each camshaft 41₁, 41₂Lubricating part 74 of the valve train system including₁74₂Communicate with.
[0044]
  Accordingly, when the oil pump 57 is driven by the rotation of the crankshaft 15 via the pump drive gear 56 and the pump shaft 61, the oil in the oil reservoir 66 is sucked up from the strainer 67 and is pumped to the filtration chamber 71. After being filtered by the oil filter 70, the lubricating portion 73 of the crankshaft 15 system and each bank 4₁, 4₂Lubricating part 74 of the valve system₁74₂These can be lubricated. In addition, the arrangement and configuration of the oil pump 57, the filtration chamber 71, the oil filter 70, and the oil supply passage 69 reduce the length of the oil supply passage 69 as much as possible, and the front and rear banks 4₁, 4₂The lubrication system for the two banks 4 can be configured substantially symmetrically.₁, 4₂Can be evenly lubricated.
[0045]
  The oil filter 70 is provided with a relief valve 70b that short-circuits between the inlet chamber 71a and the outlet chamber 71b when the filter element 70a is clogged.
[0046]
  On the other hand, in the water pump 62, as shown in FIG.₁The discharge pipe 76 is connected to the outlet of the radiator 29 (disposed in front of the internal combustion engine E as shown in FIG. 1).₂Through front bank 4₁Water jacket 24₁Connected to the bottom of the.
[0047]
  As mentioned above, front and rear banks 4₁, 4₂Each cylinder block 22₁, 22₂And cylinder head 23₁, 23₂A series of water jackets 24₁, 24₂With rear bank 4₂Cylinder head 23₂Is formed with a confluence chamber 80 that opens to the front surface of the water jacket 24.₂The upper part of is communicated.
[0048]
  Front and rear bank 4₁, 4₂The opposite water jacket 24 has a corresponding water jacket 24.₁, 24₂Lower joint 78 communicating with the lower part of₁, 78₂Projecting integrally, these joints 78₁, 78₂In addition, the lower communication water pipe 77 arranged in the valley portion 28_ThreeAre connected at both ends.
[0049]
  Front bank 4₁On the back of the jacket 23₁Upper joint 79 communicating with the upper part of₁Is formed integrally with the rear bank 4₂Cylinder head 23₂On the lower surface, there is an upper joint 79 communicating with the merge chamber 80.₂Of the upper joint 79₁79₂Rear water pipe 77 arranged in the valley 28_FourAre connected at both ends.
[0050]
  A thermostat 82 is installed in the merge chamber 80, and a thermostat cover 81 that holds the thermostat 82 and covers the opening of the merge chamber 80 has a cylinder head 23.₂Bonded to the front of the.
[0051]
  The thermostat cover 81 is integrally formed with an outlet joint 83 connected to the outlet of the thermostat 82, and the outlet joint 83 is connected to the water pipe 77._FiveIs connected to the inlet of the radiator 29 via
[0052]
  The upper joint 79₂Are integrally formed with a bypass outlet joint 84 communicating with the merging chamber 80 via a communication passage 84 ′. The bypass outlet joint 84 is connected to the rear bank 4 by a bypass water pipe 85.₂The vaporizer 12₂No greenhouse, front bank 4₁The vaporizer 12₁To the heating chamber and the suction pipe 75. The bypass outlet joint 84 is formed with a sufficiently smaller diameter than the outlet joint 83 of the thermostat cover 81.
[0053]
  The thermostat 82 shuts off the junction chamber 80 and the thermostat cover 81 when the water temperature in the junction chamber 80 is equal to or lower than a predetermined temperature, and opens the communication path 84 ′ between the junction chamber 80 and the bypass outlet joint 84. When the temperature exceeds a predetermined temperature, the junction chamber 80 and the thermostat cover 81 are communicated with each other and the communication passage 84 'is closed.
[0054]
  Therefore, when the water pump 62 is driven by the rotation of the crankshaft 15 via the pump drive gear 56 and the pump shaft 61, if the water temperature in the merging chamber 80 is relatively low, the thermostat 82 is connected to the merging chamber 80 and the thermostat. Since the space between the covers 81 is blocked and the communication path 84 ′ is opened, the cooling water is first supplied from the discharge pipe 76 to the front bank 4 by the water pump 62.₁Water jacket 24₁Then, almost half of the cooling water is immediately supplied to the lower communication pipe 77._ThreeAfter that, move to the water jacket of the second bank. And front bank 4₁Water jacket 24₁The cooling water that has passed through the upper communication water pipe 77_FourAfter going back bank 4₂Move to the merge room 80 in the rear bank 4₂Water jacket 24₂The cooling water that has passed through the convection chamber 80, exits the bypass outlet joint 84 from the merging chamber 80 via the communication path 84 ′, and is connected to the rear carburetor 12.₂And front vaporizer 12₁The heating chamber is sequentially returned to the suction pipe 75 of the water pump 62, and thereafter the same circulation is repeated. By such circulation of the cooling water without passing through the radiator 29, the warm-up of the internal combustion engine E can be promoted, and the carburetor 12₁, 12₂Can be heated to prevent icing around the fuel nozzles.
[0055]
  Both banks 4 are warming up.₁, 4₂Water jacket 24₁, 24₂When the temperature of the cooling water that has passed through the merging chamber 80 and exceeds the predetermined value, the thermostat 82 communicates between the merging chamber 80 and the thermostat cover 81 and closes the communication passage 84 ′. , Flows toward the outlet joint 83 and returns to the suction pipe 75 of the water pump 62 via the radiator 29. Thereafter, since the same circulation is repeated, both banks 4 are filled with the cooling water cooled by the heat radiation action of the radiator 29.₁, 4₂Can be effectively cooled.
[0056]
  By the way, the lower and upper communication water pipes 77_Three, 77_FourNeed only be relatively short, and they are located in the valleys between both banks, so both banks 4₁, 4₂The appearance of the internal combustion engine E is not impaired.
[0057]
  The thermostat 82 also has a front and rear bank 4₁, 4₂The thermostat 82 is installed in the merge chamber 80 where the cooling water that has cooled the water merges.₁, 4₂Accurately sense the average water temperature of both banks 4₁, 4₂It is possible to perform proper water temperature control. In addition, piping for the thermostat 82 is unnecessary, and simplification of piping can be achieved.
[0058]
  Further rear bank 4₂A thermostat cover 81 having an outlet joint 83 projecting forward is joined to the upper front surface of the water pipe 77, so that the water pipe 77 communicating the outlet joint 83 with the inlet of the radiator 29._FiveIn addition, the flow resistance can be kept small and the appearance can be improved.
[0059]
  Rear bank 4₂Upper joint 79₂Since the bypass outlet joint 84 having a smaller diameter and communicating with the merging chamber 80 is integrally formed, the upper joint 79₂And the rear bank 4 of the bypass outlet joint 84₂Can be attached at once, and piping work can be simplified.
[0060]
  Further, since the oil pump 57 and the water pump 62 are arranged on the same axis and driven by the common pump shaft 61 driven from the primary drive gear 54a, the drive system thereof can be simplified. Can do.
[0061]
  In addition, since the oil pump 57 is disposed adjacent to the overrunning clutch 53 in the radial direction, an increase in the lateral width of the internal combustion engine E can be suppressed also by the coaxial arrangement of the oil pump 57 and the water pump 62.
[0062]
  Further, since the oil pump 57 and the water pump 62 are disposed in front and above the crankshaft 15, the rear portion of the crankcase 21 and the transmission case portion 95 connected thereto are completely interfered with the oil pump 57 and the water pump 62. Therefore, the ground clearance of the internal combustion engine E can be ensured and the heights of the passenger seats 6a and 6b can be easily reduced. In this case, the oil pump 57 and the water pump 62 are arranged so that the front part of the crankcase 21 is slightly bulged.₁Therefore, the internal combustion engine E cannot be made compact.
[0063]
  Moreover, since the drive system of both pumps 57 and 62 occupying the position above the crankshaft 15 is free from the immersion of the oil reservoir 66 in the oil, the drive system does not cause oil agitation and contributes to a reduction in power loss. obtain.
[0064]
  Further, the input shaft 96 and the output shaft 97 of the transmission 8 are horizontally arranged immediately after the crankshaft 15 without being interfered with the oil pump 57 and the water pump 62, so that the transmission case 95 is made compact. It is also possible to form the upper wall flat so that the mission case portion 95 and the rear exhaust pipe 13 can be formed.₂A sufficient distance between the rear exhaust pipe 13 and the rear exhaust pipe 13₂Therefore, the influence of heat on the transmission case 95 and the transmission 8 accommodated therein can be easily avoided.
[Starting system (see FIGS. 2 and 7)]
  A housing recess 88 is formed in the front bottom surface of the crankcase 21, and the starter motor 11 is disposed in parallel therewith with the crankshaft 15. The casing 89 of the starting motor 11 has a cylindrical support 89a at one end thereof fitted in a liquid-tight manner to a through hole 90 formed in the end wall of the receiving recess 88, and a mounting arm 89b at the other end is cranked. The case 21 is attached to the crankcase 21 by fastening with bolts 111. The rotor shaft 91 of the starter motor 11 has its tip protruding into the crankcase 21, and a pinion 92 formed at the tip of the rotor shaft 91 can drive the starter gear 52 via a reduction gear train 93. . Thus, the start gear 52, the overrunning clutch 53, and the reduction gear train 93 constitute a start transmission 94 that communicates between the start motor 11 and the crankshaft 15.
[0065]
  As described above, since the starter motor 11 is disposed in front of and below the crankshaft 15, the starter motor 11 also does not hinder the compactness of the rear portion of the crankcase 21 and the transmission case portion 95, and the front portion. Bank 4₁Since it will be absorbed by the dead space below, it will not hinder downsizing of the internal combustion engine. Further, due to the above arrangement of the starter motor 11, the reduction gear train 93 is immersed in the oil in the oil sump portion 66 at the bottom of the crankcase 21, and this operates when the engine is started. There is no loss of power because the oil is not stirred during operation.
[0066]
  The present invention is not limited to the embodiments described above, and various design changes can be made without departing from the scope of the invention.
[0067]
【The invention's effect】
  As described above, according to the first aspect of the present invention, the oil pump for lubrication that supplies oil to the lubrication portions of the front and rear banks, and the cooling water that supplies cooling water to the water jackets of the front and rear banks. Since the water pump is provided in the crankcase so that these are arranged on the left and right in front of and above the crankshaft, the rear portion of the crankcase can be compactly formed without any interference with the two pumps, Therefore, a sufficient interval between the rear part of the crankcase and the rear exhaust pipe can be secured, and the influence of the radiant heat of the exhaust pipe on the crankcase can be reduced.. Further, since the oil pump and the water pump are arranged on the same axis and are driven by the common pump shaft driven from the primary drive gear, the drive system can be simplified. In addition, since the oil pump is disposed adjacent to the overrunning clutch in the radial direction, an increase in the lateral width of the internal combustion engine can be suppressed even by the coaxial arrangement of the oil pump and the water pump.
[0068]
  The first aspect of the present invention3Since the front and rear timing transmissions for driving the valve camshafts of the front and rear banks are adjacently connected to one end of the crankshaft opposite to the exhaust muffler, The rear exhaust pipe can be arranged compactly without any interference with the front and rear timing transmissions.
[Brief description of the drawings]
FIG. 1 is a side view of a motorcycle equipped with a V-type internal combustion engine of the present invention.
FIG. 2 is a side view of the internal combustion engine.
3 is an enlarged vertical sectional view of FIG. 3 part of FIG.
4 is a cross-sectional view taken along line 4-4 of FIG. 3;
5 is a cross-sectional view taken along line 5-5 of FIG.
FIG. 6 is a cooling water system diagram of the internal combustion engine.
7 is a cross-sectional view taken along line 7-7 in FIG.
FIG. 8 is an enlarged view around the front and rear timing transmission devices in FIG. 3;
FIG. 9 is an enlarged view around the transmission of FIG. 3;
FIG. 10 is a plan view around the exhaust system of the internal combustion engine.
FIG. 11 is a plan view of a cylinder head of a rear bank of the internal combustion engine.
12 is a view taken in the direction of arrow 12 in FIG.
[Explanation of symbols]
E ... Internal combustion engine
M ... Motorcycle
S ··· Adjoining distance between connecting rods in front and rear banks
1. Body frame
2 ... Rear wheel
4₁... Front bank
4₂... Rear bank
8 .... Transmission
11 ... Starting motor
13₁..Front exhaust pipe
13₂..Rear exhaust pipe
15 ... Crankshaft
21 ... Crankcase
24₁..Water jacket in front bank
24₂..Water bank in rear bank
27₁..Connecting rods in front bank
27₂..Connecting rods in rear bank
41₁..Cam axis of front bank
41₂..Cam axis of rear bank
46₁..Front timing transmission
46₂..Rear timing transmission
51₁..Exhaust port of front bank
51₂..Exhaust port of rear bank
53 ... Overrunning clutch
54a .. Primary drive gear
56 ... Pump drive gear
57 ... Oil pump
61 ... Pump shaft
62 ... Water pump
94 ... Starting transmission
95 ... Mission case section
95a ... Side wall
96 ... Input shaft
97 ・ ・ ・ Output shaft

Claims (3)

It has a front bank (4 ₁ ) and a rear bank (4 ₂ ) that open in a front-rear V-shape around a crankshaft (15) arranged in the left-right direction when mounted on the vehicle body frame (1). The transmission case (95) for accommodating the transmission (8) is integrally connected to the rear portion of the crankcase (21) for accommodating the crankshaft (15), and is connected to the front portion of the front bank (4 ₁ ). A V-type internal combustion engine for a motorcycle having a front exhaust pipe (13 ₁ ) and a rear exhaust pipe (13 ₂ ) connected to the rear part of the rear bank (4 ₂ ) ,
Front and rear bank lubricating oil pump (57) for supplying oil to lubricating portions of the (4 _1, 4 _2), and front and rear banks (4 _1, 4 ₂₎ a water jacket (24 _1, 24 ₂ ) to the one provided with a cooling water pump for supplying cooling water (62),
The overrunning clutches (53) and 1 of the starter transmission (94) are attached to one end of the crankshaft (15) in order from the inside at the side end of the crankcase (21) at one end of the crankshaft (15). A primary drive gear (54a), a pump drive gear (56) formed larger in diameter than the primary drive gear (54a) and meshing with the primary drive gear (54a), and the pump drive gear (56) A pump shaft (61) which is coupled and disposed forward and above the crankshaft (15) and extends parallel to the crankshaft (15), and an overrunning clutch (53) driven by the inner end of the pump shaft (61) The oil pump (57) disposed adjacent to the outside in the radial direction of the pump and the oil pump (57) opposite to the oil pump (57) driven by the outer end of the pump shaft (61) and the pump drive gear (56). Wherein are arranged on the side we have a water pump (62) is provided, characterized in that the two pumps (57 and 62) of Ru is arranged coaxially above and forward of the crankshaft (15), a motorcycle V-type internal combustion engine. The V-type internal combustion engine for a motorcycle according to claim 1,
An oil filter (70) connected to the discharge port of the oil pump (57) is disposed between the front and rear banks (4 ₁ , 4 ₂ ) substantially immediately above the crankshaft (15). V-type internal combustion engine for motorcycles. The V-type internal combustion engine for a motorcycle according to claim 1 or 2,
Other end of the crank shaft (15), front and rear banks (4 _1, 4 ₂₎ front and rear timing transmission for driving respectively a valve operating cam shaft (41 _1, 41 ₂₎ of (46 ₁ , 46 ₂ ) are adjacently connected to each other, a V-type internal combustion engine for motorcycles.

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