JP2013204505A - Water-cooled internal combustion engine for saddle riding type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To also obtain effective cooling by lubricating oil in addition to cooling around a cylinder head by cooling water, in a water-cooled internal combustion engine for a saddle riding type vehicle in which, in a cylinder block and a cylinder head connected to the cylinder block so as to form a water jacket inside, a cam chain chamber containing a cam chain in a travel enabled manner, is disposed at one side of a cylinder bore along the axial line direction of a crankshaft while enabling returning of the lubricating oil to the side of a crankcase.SOLUTION: A cooling water introduction passage 97 which guides cooling water to a water jacket 96 is provided so as to be adjacent to a cam chain chamber 95, more on the side of the cam chain chamber 95 from the central axial line C of a cylinder bore 37 and in an engine body 31.

Description

  The present invention includes a crankcase that rotatably supports a crankshaft, a cylinder block that is slidably fitted with a piston connected to the crankshaft, and that is coupled to the crankcase. An engine body having a cylinder head coupled to the cylinder block so that a water jacket is formed on the vehicle body frame is mounted on a vehicle body frame, and the camshaft for valve train is rotatably supported by the cylinder head. While the cam chain chamber that accommodates the cam chain that transmits the power from the vehicle is capable of traveling, it is possible to return the lubricating oil that has lubricated the valve operating device including the valve operating camshaft to the crankcase side. And disposed on one side of the cylinder bore along the axial direction of the crankshaft. Relating to the cylinder block and the saddle-ride type vehicle-cooled internal combustion engine formed in the cylinder head in the.

  Patent Document 1 discloses that a water jacket formed in a cylinder head guides cooling water from a cooling water inlet provided in the cylinder block to cool the cylinder head. Patent Document 2 discloses that the supplied lubricating oil is returned to the crack case through the cam chain chamber. In these internal combustion engines, the cylinder head is cooled by cooling water or lubricating oil. I have to.

JP 2006-97528 A JP 2008-088822 A

  However, in the case where the cylinder head is cooled with cooling water as disclosed in Patent Document 1, cooling is performed by radiating heat with a radiator, while lubrication is performed as disclosed in Patent Document 2. In the case where the cooling effect is obtained with oil, no special measures are taken with respect to the heat radiation of the lubricating oil, so that there is a problem that the cooling effect of the engine body by the lubricating oil is reduced.

  The present invention has been made in view of such circumstances, and provides a water-cooled internal combustion engine for a saddle-ride type vehicle in which effective cooling by lubricating oil is obtained in addition to cooling around a cylinder head by cooling water. The purpose is to do.

  In order to achieve the above object, the present invention includes a crankcase that rotatably supports a crankshaft, and a cylinder bore in which a piston connected to the crankshaft is slidably fitted. An engine body including a cylinder block to be coupled and a cylinder head coupled to the cylinder block so that a water jacket is formed therein is mounted on a vehicle body frame, and is a motion that is rotatably supported by the cylinder head. A cam chain chamber that movably accommodates a cam chain that transmits power from the crankshaft to the valve camshaft, lubricates the crankcase with lubricating oil that lubricates a valve operating device having the valve camshaft as a constituent element. The cylinders along the axial direction of the crankshaft In a saddle-ride type vehicle water-cooled internal combustion engine formed on the cylinder block and the cylinder head so as to be disposed on one side of a bore, the engine main body is located closer to the cam chain chamber than the central axis of the cylinder bore. A first feature is that a cooling water introduction passage for guiding cooling water to the water jacket is provided adjacent to the cam chain chamber.

  According to the present invention, in addition to the configuration of the first feature, the engine main body is mounted on the vehicle body frame with the center axis of the cylinder bore inclined forward and the cooling water introduction passage is provided in the cam chain chamber. The second feature is that it is provided at the lower part of the engine body so as to be adjacent to the lower part of the engine.

  In the present invention, in addition to the configuration of the first or second feature, a radiator and a water pump for discharging cooling water are disposed on the engine body on one end side along the axial direction of the crankshaft, A third feature is that the cam chain chamber is disposed on the opposite side of the radiator and the water pump with respect to the central axis of the cylinder bore.

  In addition to any of the configurations of the first to third features, the present invention has a fourth feature in that the cooling water introduction passage is provided across the cylinder block and the cylinder head.

  In the present invention, in addition to any of the configurations of the first to fourth features, a stud bolt hole is provided in the cylinder block and the cylinder head on the cam chain chamber side with respect to the central axis of the cylinder bore, A fifth feature is that a part of the cooling water introduction passage is disposed closer to the cam chain chamber than a virtual plane orthogonal to the axis of the crankshaft while passing through the axis of the stud bolt hole.

  According to the sixth aspect of the present invention, in addition to any one of the first to fifth features, the sixth feature is that the cooling water introduction passage is disposed between the exhaust port provided in the cylinder head and the cam chain chamber. Features.

  According to the present invention, in addition to any one of the first to sixth features, the exhaust pipe connecting pipe part forming a part of the exhaust port has a flange part forming an exhaust pipe fastening surface at a tip part. The seventh feature is that the cooling water introduction passage is formed integrally with the cylinder head so as to extend to a position corresponding to a central portion of the exhaust pipe fastening surface in the longitudinal direction of the vehicle. .

  According to the present invention, in addition to the structure of the seventh feature, the exhaust port includes a second virtual plane in which a central portion of the exhaust pipe fastening surface passes through a central axis of the cylinder bore and is orthogonal to the axis of the crankshaft. An eighth feature is that the cylinder head is formed on the side opposite to the cam chain chamber.

  In the present invention, in addition to any one of the first to eighth features, the water jacket faces the top of the piston and surrounds a combustion chamber formed between the cylinder block and the cylinder head. An opening end to the water jacket of the cooling water introduction passage formed in the cylinder head, and an opening end to the water jacket of an outlet port provided in the cylinder head so as to lead cooling water from the water jacket. Is arranged at a position sandwiching the central axis of the cylinder bore.

  The tenth feature of the present invention is that, in addition to any of the configurations of the third feature, the water pump is disposed at a position where a part of the water pump overlaps the inlet of the cooling water introduction passage in a side view. To do.

  According to the present invention, in addition to the configuration of the tenth feature, the discharge port of the water pump is disposed at a position offset from the inlet of the cooling water introduction passage in a side view, and the discharge port is formed by a flexible conduit. An eleventh feature is that the outlet and the inlet of the cooling water introduction passage are connected.

  Furthermore, in addition to the configuration of the eleventh feature, the present invention is further configured such that an end portion on the inlet side of the cooling water introduction passage of the pipe line is disposed closer to the cam chain chamber side than the central axis of the cylinder bore. There are 12 features.

  According to the first feature of the present invention, the coolant introduction passage disposed on the cam chain chamber side with respect to the central axis of the cylinder bore is provided in the engine body so as to be adjacent to the cam chain chamber. The side wall of the cam chain chamber can be cooled with the cooling water flowing through the passage, the lubricating oil flowing through the cam chain chamber to the crankcase side can be efficiently cooled, and the cooling effect of the cylinder head by the lubricating oil is enhanced. be able to. Further, since the lubricating oil is cooled by the cooling water supplied to the water jacket, it is not necessary to provide a dedicated device for cooling the lubricating oil, and the cooling system can be simplified.

  Further, according to the second feature of the present invention, the central axis of the cylinder bore is inclined forward and the cooling water introduction passage is provided at the lower part of the engine body so as to be adjacent to the lower part of the cam chain chamber. Lubricating oil returning to the crankcase side through the lower side surface in the cam chain chamber can be effectively cooled.

  According to the third feature of the present invention, the cam chain chamber is arranged on the opposite side of the radiator and the water pump with respect to the central axis of the cylinder bore, so that the cooling water cooling system is arranged at one end side along the axial direction of the crankshaft. Although the cam chain chamber is formed apart from the cooling system, the lubricating oil in the cam chain chamber can be easily provided by adjoining the cooling water introduction passage to the cam chain chamber. Can be cooled.

  According to the fourth aspect of the present invention, the cooling water introduction passage is provided across the cylinder block and the cylinder head, so that the cooling water introduction passage is provided over a relatively long distance along the cam chain chamber. The lubricating oil can be cooled more effectively.

  According to the fifth aspect of the present invention, the cam is located on the cam chain chamber side from the center axis of the cylinder bore and passes through the axis of the stud bolt hole provided in the cylinder block and the cylinder head, and the cam is more than the virtual plane orthogonal to the axis of the crankshaft. Since a part of the cooling water introduction passage is disposed on the chain chamber side, the cooling water introduction passage can be brought close to the cam chain chamber side to further enhance the cooling effect of the lubricating oil.

  According to the sixth aspect of the present invention, since the cooling water introduction passage is arranged between the exhaust port and the cam chain chamber, the cooling water introduction passage is arranged by effectively utilizing the space between the exhaust port and the cam chain chamber. As a result, it is possible to form a cooling water introduction passage that can ensure a sufficient passage length by being easily along the cam chain chamber.

  According to the seventh feature of the present invention, it corresponds to the central portion of the exhaust pipe fastening surface formed by the flange portion at the tip of the exhaust pipe connecting pipe portion provided in the cylinder head so as to form a part of the exhaust port. Since the coolant introduction passage extends in the front-rear direction of the vehicle up to the position, the coolant length in the coolant introduction passage can be sufficiently secured to effectively cool the lubricating oil in the cam chain chamber.

  According to the eighth feature of the present invention, since the central portion of the exhaust pipe fastening surface is offset to the opposite side of the cam chain chamber with respect to the central axis of the cylinder bore, the space between the cam chain chamber and the exhaust port is reduced. It is possible to secure the degree of freedom in designing the cooling water introduction passage.

  According to the ninth aspect of the present invention, the opening end of the cooling water introduction passage to the water jacket formed in the cylinder head so as to surround the combustion chamber, and the outlet port for leading the cooling water from the water jacket to the water jacket. Since the opening end is arranged at a position sandwiching the center axis of the cylinder bore, the cooling water introduced into the water jacket from the cooling water introduction passage is easily dispersed in two directions in the water jacket so that the periphery of the combustion chamber Therefore, the cooling efficiency of the combustion chamber can be increased by allowing the cooling water to sufficiently spread.

  According to the tenth feature of the present invention, a part of the water pump overlaps the inlet of the cooling water introduction passage in a side view, so that the cooling system can be made compact in the vehicle front-rear direction.

  According to the eleventh feature of the present invention, the outlet of the water pump offset from the inlet of the cooling water introduction passage in a side view and the inlet of the cooling water introduction passage are connected by a flexible conduit. Therefore, it is possible to easily connect the discharge port of the water pump and the inlet of the cooling water introduction passage to increase the degree of freedom in arrangement of the water pump.

  Further, according to the twelfth feature of the present invention, since the pipe line is connected to the inlet side of the cooling water introduction passage on the cam chain chamber side with respect to the central axis of the cylinder bore, the discharge port of the water pump and the cooling water introduction passage Even when the pipes are bent by separating the inlets of the pipes to ensure the pipe length of the pipes, they can be bent without difficulty.

1 is a side view of a scooter type motorcycle. FIG. It is an enlarged side view of a power unit. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 3 is a side view of a main part in a state where a radiator cover is removed from FIG. 2. FIG. 5 is a sectional view taken along line 5-5 of FIG. It is a 6-6 line arrow directional view of FIG. It is a 7-7 line arrow directional view of FIG. FIG. 8 is a view taken in the direction of arrow 8 in FIG. 4.

  Embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the front and rear, the top and bottom, and the left and right directions are directions as viewed from the occupant riding the motorcycle.

  First, in FIG. 1, a body frame F of a scooter type motorcycle that is a saddle-ride type vehicle includes a head pipe 11 at the front end thereof, a main frame 12 having a front end portion coupled to the head pipe 11, and a vehicle width direction. A cross pipe 13 that extends and is provided at the rear portion of the main frame 12 and a pair of left and right rear frames 14 that are connected to both ends of the cross pipe 13 at the front end portions. A front fork 15 that supports the front wheel WF and a rod-shaped steering handle 16 are supported on the head pipe 11 so as to be steerable.

  The main frame 12 integrally includes a down frame portion 12a inclined downward from the head pipe 11 and a lower frame portion 12b extending substantially rearward from the rear end of the down frame portion 12a. One pipe is formed by bending. The rear frame 14 is inclined upward and backward from the cross pipe 13 and extends upward, and the rear frame 14 extends upward from the upper end of the rising frame portion 14a at a gentler inclination angle than the rising frame portion 14a. The seat rail portion 14b that is inclined and extends rearward is integrally formed, and a single pipe is formed by bending.

  A unit swing type power unit P is connected via a link 18 to a bracket 17 provided at a front portion of the rear frames 14 in the body frame F, that is, a lower portion of the rising frame portion 14a, and the power unit P swings up and down. The rear wheel WR is pivotally supported on the rear portion of the power unit P, while being supported by the vehicle body frame F so as to be able to move. Further, a rear cushion unit 19 is provided between the rear portion of the seat rail portion 14b of the left rear frame 14 and the rear portion of the power unit P among the pair of left and right rear frames 14.

  A storage box 20 is supported between the front portions of the rear frames 14 in the vehicle body frame F, and a tandem type riding seat 21 that covers the storage box 20 from above can be opened and closed. Supported by Further, a fuel tank 22 supported by the rear frames 14 is disposed behind the storage box 18 so as to be covered with the riding seat 21.

  The vehicle body frame F, a part of the power unit P, the storage box 20 and the fuel tank 22 are covered with a vehicle body cover 23, and a leg shield that covers a leg portion of an occupant sitting on the riding seat 21 from the front. 24, a step floor 25 connected to the lower part of the leg shield 24 so that an occupant sitting on the riding seat 21 places his / her foot on the front side of the power unit P, and both sides of the step floor 25 A pair of left and right skirt portions 26 that hang downward from the side, and a side cover 27 that covers the storage box 20 and the fuel tank 22 from the side.

  2 and 3, the power unit P includes a water-cooled internal combustion engine E and a power transmission device T that transmits the rotational power of the internal combustion engine E to the rear wheel WR. The engine body 31 of the engine E is provided with a crankcase 32 for rotatably supporting a crankshaft 36 having an axis along the vehicle width direction, and a cylinder bore 37 having a center axis C slightly inclined upward. The cylinder block 33 is coupled to the crankcase 32, the cylinder head 34 is coupled to the cylinder block 33, and the head cover 35 is coupled to the cylinder head 34. The crankcase 32 is divided into left and right parts. The left case half 38 and the right case half 39 are connected to each other.

  A piston 40 connected to the crankshaft 36 is slidably fitted to the cylinder bore 37, and a combustion chamber 41 that faces the top of the piston 40 between the cylinder block 33 and the cylinder head 34. A spark plug 42 is attached to the right side wall of the cylinder head 34 so that the tip of the combustion chamber 41 faces the tip.

  Referring also to FIG. 4, a radiator 43 and a water pump 44 for discharging cooling water are provided in the engine body 31 on one end side (right end side in this embodiment) along the axial direction of the crankshaft 36. In this embodiment, the radiator 43 is fixed to a right case half 39 of the crankcase 32, and the water is arranged in front of the radiator 43 and on the right side of the cylinder block 33. A pump 44 is supported on the right case half 39.

  On the other hand, the power transmission device T is interposed between the other end portion along the axial direction of the crankshaft 36 and the axle 45 of the rear wheel WR. 32, and is accommodated in a transmission case 46 that is connected to the left case half 38 and extends to the left side of the rear wheel WR, and includes a belt-type continuously variable transmission 47, a centrifugal clutch 48, a gear reduction mechanism 49, Consists of.

  An axle 45 of the rear wheel WR is rotatably supported on the transmission case 46, and a transmission shaft 50 disposed between the crankshaft 36 and the axle 45 is rotatably supported. The continuously variable transmission 47 is formed by winding a V belt 53 around a drive pulley 51 provided at the left end of the crankshaft 36 and a driven pulley 52 supported rotatably on the transmission shaft 50. The drive pulley 51 is configured to change the winding diameter of the V belt 53 according to the rotational speed of the crankshaft 36, and the driven pulley 52 has a winding diameter according to the change in the winding diameter of the drive pulley 51. Configured to change. The centrifugal clutch 48 is provided between the driven pulley 52 and the transmission shaft 50, and the gear transmission mechanism 49 is provided between the transmission shaft 50 and the axle 45.

  In FIG. 2 again, the right end portion of the crankshaft 36 passes through the right case half 39 via a ball bearing 55 with a seal so as to freely rotate. A housing forming portion 39a that protrudes slightly from the outer surface of the right case half 39 and surrounds the crankshaft 36 is connected to the housing forming portion 39a. The cover member 56 is fastened. Thus, the crankshaft 36 also rotatably penetrates the cover member 56, and an annular seal member 57 is interposed between the cover member 56 and the crankshaft 36.

  An outer rotor 59 is fixed to the right end portion of the crankshaft 36 at a portion protruding from the cover member 56, and an inner stator 60 surrounded by the outer rotor 59 so as to form a generator 58 together with the outer rotor 59. Is fixed to the cover member 56.

  A cooling fan 61 is fixed to the right end portion of the crankshaft 36 so as to be disposed outside the generator 58. In this embodiment, the cooling fan 61 is fixed to the outer rotor 59 of the generator 58. The cooling fan 61 is fixed by a plurality of bolts 62.

  A radiator 43 is arranged on the axially outward side of the cooling fan 61 on the right side of the crankshaft 36. The radiator 43 includes an upper tank 63, a lower tank 64 disposed below the upper tank 63, and a core portion 65 provided between the upper tank 63 and the lower tank 64. The lower tank 64 is fixed to the right case half 39 of the crankcase 32. That is, the right case half 39 is integrally provided with an extending portion 39b extending outward so as to surround the generator 58, and the upper tank 63 and the lower tank 64 are provided in the extending portion 39b. It is concluded.

The radiator 43 is covered from the outside with a radiator cover 66, and the radiator cover 66 is also fixed to the extending portion 39 b of the right case half 39. Thus, the radiator cover 66 is formed in a dish shape so as to cover the radiator 43 from the outside, and an exhaust port 67 for exhausting air from the cooling fan 61 is provided at the rear of the radiator cover 66. It is done. The radiator cover 66 is formed with a cooling air introduction port 68 that is opened corresponding to the core portion 65 of the radiator 43, and a lattice portion 69 that divides the cooling air introduction port 68 into a plurality of portions in the vertical and front and rear directions. Referring also to FIG. 5, an oil pump 70 is located in the housing forming portion 39 a provided in the right case half 39 of the crankcase 32 so as to be positioned in front of the crankshaft 36. The pump housing 71 of the oil pump 70 is fastened to the right case half 39 with a plurality of bolts 72. An inner rotor 74 and an outer rotor 75 meshing with the inner rotor 74 are accommodated in a pump chamber 73 formed in the pump housing 71, and a pump shaft 76 to which the inner rotor 74 is fixed serves as the pump. The housing 71 and the cover member 56 are rotatably supported.

  The pump shaft 76 is provided with a driven gear 77, and a driving gear 78 meshing with the driven gear 77 is fixed to the crankshaft 36 as shown in FIG. That is, rotational power is transmitted from the crankshaft 36 to the oil pump 70.

  By the way, the housing forming portion 39a that is integrally projected on the outer surface of the right case half 39 and a part of the cover member 56 that is fastened to the housing forming portion 39a are formed on the extended portion 39b of the right case half 39. The pump case 78 of the water pump 44 is formed so as to protrude from the front lower part to the right side of the cylinder block 33. The pump case 78 of the water pump 44 includes a front part of the cover member 56 and a pump cover 79 fastened to the cover member 56. Consists of.

  An impeller 81 is accommodated in a pump chamber 80 formed in the pump case 78, and a pump shaft 82 to which the impeller 81 is fixed penetrates the cover member 56 of the pump case 78 in a liquid-tight manner, The housing forming portion 39a and the cover member 56 are rotatably supported. Moreover, an endless chain 85 is wound around a drive sprocket 83 fixed to the pump shaft 76 of the oil pump 70 and a driven sprocket 84 fixed to the pump shaft 82 of the water pump 44, and the water pump 44, the rotational power from the crankshaft 36 is transmitted through the oil pump 70.

  A valve operating device 89 that opens and closes an intake valve 87 and an exhaust valve 88 disposed in the cylinder head 34 is accommodated between the cylinder head 34 and the head cover 35, and a part of the valve operating device 89 is accommodated. The camshaft 90 for a valve that constitutes the shaft has an axis parallel to the crankshaft 36 and is rotatably supported by the cylinder head 34.

  Rotational power of the crankshaft 36 is transmitted to the valve camshaft 90 via a timing transmission mechanism 91. The timing transmission mechanism 91 is a drive sprocket provided on the crankshaft 36. 92, a driven sprocket 93 provided on the valve camshaft 90, and an endless cam chain 94 wound around the drive sprocket 92 and the driven sprocket 93.

  The cylinder block 33 and the cylinder are arranged such that a cam chain chamber 95 for running the cam chain 94 is disposed on one side of the cylinder bore 37 (left side in this embodiment) along the axis of the crankshaft 36. A radiator 43 and a water pump 44 are disposed on the crankcase 32 of the engine body 31 on one end side (right end side) along the axial direction of the crankshaft 36, which is formed on the head 34. The cam chain chamber 95 is disposed on the opposite side of the radiator 43 and the water pump 44 with respect to the central axis C of the cylinder bore 37. Moreover, the cam chain chamber 95 can return the lubricating oil that has lubricated the valve gear 89 to the crankcase 32 side.

  Referring also to FIG. 6, a water jacket 96 surrounding the combustion chamber 41 is formed on the cylinder head 34, and a plurality of fins 33 a are projected on the outer surface of the cylinder block 33.

  7 and 8 together, the cooling water discharged from the water pump 44 is supplied to the water jacket 96 from a cooling water introduction passage 97 provided in the machine body 31. The water introduction passage 97 is provided in the engine body 31 so as to be adjacent to the cam chain chamber 95. In addition, the engine body 31 is mounted on the vehicle body frame F with the central axis C of the cylinder bore 37 inclined forward and the cooling water introduction passage 97 is adjacent to the lower portion of the cam chain chamber 95. It is provided in the lower part of the engine body 31.

  The cooling water introduction passage 97 is provided across the cylinder block 33 and the cylinder head 34 in the engine body 31, and is connected to the passage 98 provided in the cylinder block 33 and the passage 98. Thus, the coolant introduction passage 97 is constituted by the passage 99 directed toward the cylinder head 34.

  As shown in FIGS. 6 and 7, a plurality of, for example, four stud bolts (not shown) for fastening the cylinder block 33 and the cylinder head 34 to the crankcase 32 are inserted into the cylinder block 33 and the cylinder head 34. Stud bolt holes 100, 101, 102, 103 are provided so as to surround the cylinder bore 37 and the combustion chamber 41, and two stud bolt holes 100, 101 out of the stud bolts 100 to 103 are formed in the cylinder bore 37. Although arranged on the cam chain chamber 95 side with respect to the central axis C, a part of the cooling water introduction passage 97 is located on the cam chain chamber 95 side with respect to the central axis C of the cylinder bore 37. The clan passes through the axis of the holes 100 and 101 It is disposed 95 side the cam chain chamber than in the first virtual plane PL1 orthogonal to the axis of the shaft 36.

  By the way, the cylinder head 34 is provided with an exhaust port 106 that is controlled by the exhaust valve 88 to be communicated / blocked to the combustion chamber 41 so as to open on the lower side surface of the cylinder head 34. FIG. As will be clearly shown, the cooling water introduction passage 97 is disposed between the exhaust port 106 and the cam chain chamber 95.

  Further, the exhaust pipe connecting pipe portion 107 that forms a part of the exhaust port 106 has a flange portion 107a that forms an exhaust pipe fastening surface 108 for fastening the exhaust pipe 109 at the distal end portion. As shown in FIG. 8, the cooling water introduction passage 97 is formed integrally and extends to a position corresponding to the central portion CO of the exhaust pipe fastening surface 108 in the front-rear direction of the vehicle.

  The exhaust port 106 has a central portion of the exhaust pipe fastening surface 108 passing through the central axis C of the cylinder bore 37 and the cam chain chamber 95 with respect to the second imaginary plane PL2 orthogonal to the axis of the crankshaft 36. Are formed on the cylinder head 34 so as to be arranged on the opposite side.

  Further, the cooling water is introduced from the opening end of the cooling water introduction passage 97 to the water jacket 96, that is, the opening end 99a of the passage 99 provided in the cylinder head 34 to the water jacket 96, and the water jacket 96. An opening end 110a of the outlet 110 provided in the cylinder head 34 to the water jacket 96 is arranged at a position sandwiching the central axis C of the cylinder bore 37 as shown in FIG. Thus, the opening end 99a of the cooling water introduction passage 97 to the water jacket 96 is disposed at the lower left portion of the cylinder head 34, whereas the opening end 110a of the outlet 110 to the water jacket 96 is It is arranged at the upper right part of the cylinder head 34.

  The inlet of the cooling water introduction passage 97, that is, the inlet 98a of the passage 98 provided in the cylinder block 33 is opened toward the right side of the cylinder block 33, and a part of the water pump 44 is the cooling water. It arrange | positions so that it may overlap with the inlet_port | entrance 98a of the introduction channel | path 97 by a side view.

  Further, the discharge port 111 of the water pump 44 is disposed at a position offset from the inlet 98a of the cooling water introduction passage 97 in a side view, in this embodiment, a position offset forward, and is a flexible pipe. The hose 112, which is a path, connects the discharge port 111 and the inlet 98a of the cooling water introduction passage 97. That is, straight connection pipes 113 and 114 are fitted and fixed to the inlet 98a and the discharge port 111, and the connection pipes 113 and 114 are connected by the hose 112.

  Further, an end 112a of the hose 112 on the inlet 98a side of the cooling water introduction passage 97 is disposed on the cam chain chamber 95 side of the center axis C of the cylinder bore 37 as shown in FIG. That is, the inlet 98a side of the cooling water introduction passage 97 of the hose 112 is closer to the cam chain chamber 95 side than the second imaginary plane PL2 passing through the central axis C of the cylinder bore 37 and orthogonal to the axis line of the crankshaft 36. The end 112a is disposed.

  A straight tubular connecting pipe 115 is fitted and fixed to the outlet 110 provided in the cylinder head 34, and the upstream end of the hose 116 is connected to the connecting pipe 115, and the hose 116 is connected to the joint 117 and the hose 118. To the upper tank 63 of the radiator 43.

  A lead-out pipe 119 is provided in the lower tank 64 of the radiator 43. On the other hand, a thermostat case 121 containing a thermostat 120 is fixedly disposed in the pump case 78 of the water pump 44, and a lead-out pipe 119 for leading cooling water from the lower tank 64 is connected via a hose 122. Connected to the thermostat case 121. Further, the joint 117 in the course of guiding the cooling water led out from the water jacket 96 of the cylinder head 34 to the radiator 43 side and the thermostat case 121 are connected via a bypass hose 123, and the thermostat 120. Adjusts the amount of cooling water flowing from the bypass hose 123 to the water pump 44 according to the temperature of the cooling water.

  Next, the operation of this embodiment will be described. Cooling water is supplied to the engine main body 31 on the cam chain chamber 95 side of the center axis C of the cylinder bore 37 provided on the cylinder block 33 and to the water jacket 96 provided on the cylinder head 34. Since the leading cooling water introduction passage 97 is provided so as to be adjacent to the cam chain chamber 95, the side wall of the cam chain 95 chamber can be cooled with the cooling water flowing through the cooling water introduction passage 97. The lubricating oil flowing to the crankcase 32 side can be efficiently cooled, and the cooling effect of the cylinder head 34 by the lubricating oil can be enhanced. Further, since the lubricating oil is cooled by the cooling water supplied to the water jacket 96, it is not necessary to provide a dedicated device for cooling the lubricating oil, and the cooling system can be simplified.

  Further, the engine body 31 is mounted on the vehicle body frame F with the central axis C of the cylinder bore 37 inclined forward and the cooling water introduction passage 97 is adjacent to the lower part of the cam chain chamber 95 and the lower part of the engine body 31. Therefore, the lubricating oil that travels along the lower side surface in the cam chain chamber 95 and returns to the crankcase 32 can be effectively cooled.

  Further, a radiator 43 and a water pump 44 for discharging cooling water are disposed on the crankcase 32 of the engine body 31 on one end side along the axial direction of the crankshaft 36, and the cam chain chamber 95 is the central axis of the cylinder bore 37. Since it is arranged on the opposite side of the radiator 43 and the water pump 44 with respect to C, the cooling water cooling system can be compactly constructed on one end side along the axial direction of the crankshaft 36 and separated from the cooling system. Despite the formation of the cam chain chamber 95, the lubricating oil in the cam chain chamber 95 can be easily cooled by making the cooling water introduction passage 97 adjacent to the cam chain chamber 95.

  Moreover, since the cooling water introduction passage 97 is provided across the cylinder block 33 and the cylinder head 34 of the engine body 31, the cooling water introduction passage 97 is provided over a relatively long distance along the cam chain chamber 95. The lubricating oil can be cooled more effectively.

  The cylinder block 33 and the cylinder head 34 are provided with stud bolt holes 100 and 101 on the cam chain chamber 95 side of the center axis C of the cylinder bore 37, and a part of the cooling water introduction passage 97 is part of the stud bolt. Since it is arranged closer to the cam chain chamber 95 than the first virtual plane PL1 passing through the axes of the holes 100 and 101 and orthogonal to the axis of the crankshaft 36, the cooling water introduction passage 97 is made closer to the cam chain chamber 95. Further, the cooling effect of the lubricating oil can be further enhanced.

  Further, since the cooling water introduction passage 97 is disposed between the exhaust port 106 and the cam chain chamber 95 provided in the cylinder head 34, the space between the exhaust port 106 and the cam chain chamber 95 is effectively used to set the cooling water introduction passage 97. By disposing the cooling water, it is possible to form the cooling water introduction passage 97 so that a sufficient passage length can be secured by making it easy to follow the cam chain chamber 95.

  Further, an exhaust pipe connecting pipe portion 107 that forms a part of the exhaust port 106 is provided integrally with the cylinder head 34 with a flange portion 107a that forms the exhaust pipe fastening surface 108 at the distal end, and a cooling water introduction passage 97. Is formed so as to extend to a position corresponding to the center portion CO of the exhaust pipe fastening surface 108 in the front-rear direction of the vehicle, so that the passage length of the cooling water introduction passage 97 is sufficiently secured to lubricate the cam chain chamber 95. The oil can be cooled effectively.

  The exhaust port 106 has a central portion CO of the exhaust pipe fastening surface 108 that passes through the central axis C of the cylinder bore 37 and is opposite to the cam chain chamber 95 with respect to a second virtual plane PL2 that is orthogonal to the axis of the crankshaft 36. The central portion CO of the exhaust pipe fastening surface 108 is offset to the opposite side of the cam chain chamber 95 with respect to the central axis C of the cylinder bore 37. Therefore, a space between the cam chain chamber 95 and the exhaust port 106 can be secured, and the degree of freedom in designing the cooling water introduction passage 97 can be increased.

  The water jacket 96 provided in the cylinder head 34 is formed so as to surround the combustion chamber 41, and the cooling water is led out from the opening end 99 a of the cooling water introduction passage 97 to the water jacket 96 and the water jacket 96. Since the opening end 110a of the outlet 110 provided in the cylinder head 34 to the water jacket 96 is disposed at a position sandwiching the central axis C of the cylinder bore 37, the outlet 110 is introduced into the water jacket 96 from the cooling water introduction passage 97. The cooling water can be easily dispersed in two directions in the water jacket 96 so that the cooling water can be sufficiently spread around the combustion chamber 41, thereby improving the cooling efficiency of the combustion chamber 41.

  Further, since the water pump 44 is disposed at a position where a part of the water pump 44 overlaps the inlet 98a of the cooling water introduction passage 97 in a side view, the cooling system can be made compact in the vehicle front-rear direction.

  Further, the discharge port 111 of the water pump 44 is disposed at a position offset from the inlet 98a of the cooling water introduction passage 97 in a side view, and the discharge port 111 and the cooling water introduction passage are formed by a hose 112 which is a flexible conduit. 97, the outlet 98a of the water pump 44 and the inlet 98a of the cooling water introduction passage 97 are easily connected to increase the degree of freedom in arrangement of the water pump 44. it can.

  Further, the end portion 112a on the inlet 98a side of the cooling water introduction passage 97 of the hose 112 is disposed on the cam chain chamber 95 side with respect to the central axis C of the cylinder bore 37, so that the discharge port 111 of the water pump 44 and the cooling water are provided. Even when the hose 112 is bent by separating the inlets 98a of the introduction passage 97 to ensure the length of the hose 112, the hose 112 can be bent without difficulty.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

31 ... Engine body 32 ... Crankcase 33 ... Cylinder block 34 ... Cylinder head 36 ... Crankshaft 37 ... Cylinder bore 40 ... Piston 41 ... Combustion chamber 43 ... Radiator 44 ... Water pump 89 ... Valve operating device 90 ... Valve cam shaft 94 ... Cam chain 95 ... Cam chain chamber 96 ... Water jacket 97 ... Cooling water introduction passage 98 ... Open end 98a of cooling water introduction passage to water jacket ... Cooling water introduction passage 100, 101 ... Stud bolt hole 106 ... Exhaust port 107 ... Exhaust pipe connecting pipe 107a ...・ Flange portion 108... Exhaust pipe fastening surface 110... Outlet port 110 a... Opening end 111 to outlet water jacket. ··· Hose 112a which is a pipe ··· End C on the inlet side of the cooling water introduction passage of the hose · · · Center axis CO of the cylinder bore · · · Center portion F of the exhaust pipe fastening surface · · · Body frame PL1 ..Virtual plane PL2 ... second virtual plane

Claims (12)

  A crankcase (32) for rotatably supporting the crankshaft (36) and a cylinder bore (37) in which a piston (40) connected to the crankshaft (36) is slidably fitted. Engine body comprising a cylinder block (33) coupled to the crankcase (32) and a cylinder head (34) coupled to the cylinder block (33) so that a water jacket (96) is formed therein. A cam chain (31) is mounted on the vehicle body frame (F) and transmits the power from the crankshaft (36) to the valve camshaft (90) rotatably supported by the cylinder head (34). 94) a cam chain chamber (95) that movably accommodates a valve operating device (89) comprising the valve operating cam shaft (90) as a constituent element. The cylinder is arranged on one side of the cylinder bore (37) along the axial direction of the crankshaft (36) while allowing the lubricating oil lubricated to be returned to the crankcase (32) side. In the water-cooled internal combustion engine for saddle riding type vehicles formed in the block (33) and the cylinder head (34), the engine is located closer to the cam chain chamber (95) than the central axis (C) of the cylinder bore (37). A saddle-ride type vehicle characterized in that a cooling water introduction passage (97) for guiding cooling water to the water jacket (96) is provided in the main body (31) so as to be adjacent to the cam chain chamber (95). Water-cooled internal combustion engine.   The engine body (31) is mounted on the vehicle body frame (F) with the center axis (C) of the cylinder bore (37) inclined forward and the cooling water introduction passage (97) is connected to the cam chain chamber. The water-cooled internal combustion engine for a saddle-ride type vehicle according to claim 1, wherein the water-cooled internal combustion engine for a saddle-ride type vehicle is provided at a lower portion of the engine body (31) so as to be adjacent to a lower portion of (95).   On the one end side along the axial direction of the crankshaft (36), a radiator (43) and a water pump (44) for discharging cooling water are disposed in the engine body (31), and the cam chain chamber (95 The saddle-riding side according to claim 1 or 2, characterized in that it is arranged on the opposite side of the radiator (43) and the water pump (44) with respect to the central axis (C) of the cylinder bore (37). A water-cooled internal combustion engine for vehicles.   The saddle riding type vehicle according to any one of claims 1 to 3, wherein the cooling water introduction passage (97) is provided across the cylinder block (33) and the cylinder head (34). Water-cooled internal combustion engine.   Stud bolt holes (100, 101) are provided in the cylinder block (33) and the cylinder head (34) closer to the cam chain chamber (95) than the central axis (C) of the cylinder bore (37), A part of the cooling water introduction passage (97) passes through the axis of the stud bolt hole (100, 101) and is more than the imaginary plane (PL1) perpendicular to the axis of the crankshaft (36), the cam chain chamber (95 The water-cooled internal combustion engine for a saddle-ride type vehicle according to any one of claims 1 to 4, wherein   The cooling water introduction passage (97) is disposed between an exhaust port (106) provided in the cylinder head (34) and the cam chain chamber (95). A water-cooled internal combustion engine for saddle riding type vehicles as described in 1.   The exhaust pipe connecting pipe part (107) forming a part of the exhaust port (106) has a flange part (107a) forming an exhaust pipe fastening surface (108) at its tip part, and the cylinder head (34). The cooling water introduction passage (97) is formed so as to extend to a position corresponding to the central portion (CO) of the exhaust pipe fastening surface (108) in the longitudinal direction of the vehicle. A water-cooled internal combustion engine for a saddle-ride type vehicle according to any one of claims 1 to 6.   The exhaust port (106) has a central portion (CO) of the exhaust pipe fastening surface (108) passing through the central axis (C) of the cylinder bore (37) and orthogonal to the axis of the crankshaft (36). The saddle riding type according to claim 7, wherein the saddle riding type is formed on the cylinder head (34) so as to be disposed on the opposite side of the cam chain chamber (95) with respect to two virtual planes (PL2). A water-cooled internal combustion engine for vehicles.   The cylinder head (34) is configured such that the water jacket (96) faces the top of the piston (40) and surrounds a combustion chamber (41) formed between the cylinder block (33) and the cylinder head (34). ) And an opening end (99a) of the cooling water introduction passage (97) to the water jacket (96), and the cylinder head (34) so that the cooling water is led out from the water jacket (96). An opening end (110a) of the outlet port (110) provided in the water jacket (96) is disposed at a position sandwiching a central axis (C) of the cylinder bore (37). The water-cooled internal combustion engine for saddle riding type vehicles according to any one of 1 to 8.   4. The saddle-ride type vehicle according to claim 3, wherein the water pump (44) is disposed at a position where a part of the water pump (44) overlaps the inlet (98a) of the cooling water introduction passage (97) in a side view. Water-cooled internal combustion engine.   The discharge port (111) of the water pump (44) is disposed at a position offset from the inlet (98a) of the cooling water introduction passage (97) in a side view, and the flexible pipe (112) The water-cooled internal combustion engine for a saddle-ride type vehicle according to claim 10, wherein the discharge port (111) and the inlet (98a) of the cooling water introduction passage (97) are connected.   An end (112a) on the inlet (98a) side of the cooling water introduction passage (97) of the pipe (112) is closer to the cam chain chamber (95) side than the central axis (C) of the cylinder bore (37). The water-cooled internal combustion engine for a saddle-ride type vehicle according to claim 11, wherein the internal combustion engine is a saddle type vehicle.

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