JP2015090127A - Engine of motor cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine of a motor cycle in which a starter motor and a water pump are disposed at an area located at the rear side of a cylinder of the engine and in an upper part of a crank case to achieve compactification and weight reduction of the engine and secure a sufficient bank angle of a vehicle.SOLUTION: In an engine 12 of a motor cycle according to the invention, a cylinder of the engine 12 is provided at a front side upper part of a crank case 22. A starter motor 30 for starting the engine 12 and a water pump 31 for circulating a coolant are disposed at an area which is located at the rear side of the cylinder 24 and in an upper part of the crank case 22. A portion from the starter motor 30 to an engine start system 34 is connected with a pump drive shaft 58 of the water pump 31 to drive the water pump 31.

Description

  The present invention relates to an engine of a motorcycle in which an engine starter and a water pump are disposed behind a cylinder of the engine.

  Some motorcycles are equipped with a water-cooled parallel multi-cylinder engine (see Patent Documents 1 to 3).

  In the parallel four-cylinder engine of a motorcycle described in Patent Document 1, a water pump for circulating cooling water is disposed on the outer surface of the cylinder (in the vehicle body width direction) in the vicinity of the cylinder, and through a sprocket-chain mechanism dedicated to driving the water pump. The water pump is driven. An oil pump for engine lubrication is disposed in the lower part of the crankcase of the engine, and the oil pump is driven by the rotation of the crankshaft through a sprocket-chain mechanism dedicated to driving the pump.

  Further, a clutch mechanism and a transmission are arranged on the rear side in the crankcase of the engine, and an engine starting device including a starter motor and a starting gear train is arranged on the upper part of the transmission. The engine can be started by the engine starter by operating the starter motor.

  On the other hand, as described in Patent Document 2, many motorcycle engines are provided coaxially with a water pump for circulating coolant and an oil pump for engine lubrication on the left side in the vehicle body width direction in the crankcase of the engine. .

  In this motorcycle engine, an engine starter having a starter motor and a starter gear train is disposed on the left side of the crankshaft in front of the vehicle body, and a start pulley shaft (counter) from a clutch mechanism is provided behind the crankcase in the vehicle. Some have an oil pump and a water pump disposed on the left shaft end side of the shaft.

  Further, in the motorcycle engine disclosed in Patent Document 3, an engine starting device including a starter motor and a starting gear train is provided between the cylinder and the generator on the upper surface of the crankcase, and the engine starting system from the starter motor is used as the generator driving system. There is something shared with some of them.

JP 2005-36776 A JP 2008-163899 A JP-A-4-246276

  In the motorcycle engine described in Patent Document 1, the water pump is disposed on the outer side surface of the crankcase in the vehicle body width direction near the crankshaft, and the water pump is driven from the crankshaft through a sprocket-chain mechanism dedicated to driving the water pump. The It is difficult to ensure a sufficient bank angle of the vehicle, and the water pump and oil pump are driven through dedicated sprocket-chain mechanisms, respectively, which complicates the pump drive configuration of the water pump and oil pump, and the engine The size has increased, leading to an increase in weight and cost.

  Further, in the motorcycle engine described in Patent Document 2, an oil pump and a water pump are arranged coaxially on the rear side of the engine crankcase, but the drive is placed on the lower left side of the engine. Since sprockets, drive chains, gear shift levers, side stands, etc. are densely arranged, it is difficult to secure a space for arranging the water pump.

  For this reason, in a motorcycle engine, the water pump provided at the shaft end is disposed at a position moved in the vehicle body width direction from the center of the vehicle. There was a problem of increasing the weight by extending the hose length.

  Furthermore, in the motorcycle engine described in Patent Document 3, an engine starter provided with a starter motor is provided between the cylinder and the generator on the upper surface of the crankcase of the engine to reduce the size of the engine. Although a part of the generator drive system is shared by the engine start system, there is no suggestion or wearing of a technique for always driving the water pump using the engine start system.

  The present invention has been made in consideration of the above-described circumstances. A starter motor and a water pump are arranged behind the cylinder of the engine and above the crankcase to reduce the engine size and weight, and to reduce the bank angle of the vehicle. An object of the present invention is to provide a motorcycle engine that can sufficiently secure the vehicle.

  Another object of the present invention is to use an engine start system from a starter motor as a drive system for a water pump, eliminating the need for a pump drive system independent of the water pump, simplifying the configuration, making the engine compact and lightweight. An object of the present invention is to provide a motorcycle engine that can be realized.

  In order to solve the above-described problems, a motorcycle engine according to the present invention is a motorcycle engine in which a cylinder of an engine is provided at an upper front portion of a crankcase, and the engine is disposed behind the cylinder and above the crankcase. A starter motor for starting and a water pump for circulating cooling water are arranged, a part of an engine starting system from the starter motor is connected to a pump drive shaft of the water pump, and the water pump is driven. It is what.

  In the motorcycle engine according to the present invention, since the starter motor and the water pump are arranged behind the cylinder of the engine and at the upper part of the crankcase, the water pump is not located outside the crankcase body, The bank angle of the vehicle can be secured sufficiently, the water pump can be driven at all times by using the engine start system from the starter motor, and an independent pump drive system of the water pump is not required. Simplification can be achieved, and the engine can be made compact and light.

1 is a left side view of a motorcycle equipped with a motorcycle engine according to the present invention. FIG. 2 is a side sectional view of an engine mounted on the motorcycle of FIG. 1. Sectional drawing which follows the III-III line | wire of FIG. The figure which shows the drive system of the water pump using the engine starting system of the starter motor.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a left side view showing the overall appearance of the motorcycle. In FIG. 1, the front side of the vehicle is represented by a symbol “F”, and the rear side of the vehicle is represented by a symbol “R”.

  In the motorcycle 10, a water-cooled parallel multi-cylinder engine 12 is mounted on a vehicle body 11 having a frame structure, and driving wheels are driven by the parallel multi-cylinder engine 12. The motorcycle 10 includes a vehicle main body 11, a front wheel 13 that is a steering wheel, a steering handle 14 that steers the front wheel 13, and a rear wheel 15 that is a driving wheel. The vehicle body 11 has a pair of left and right main frames 18 extending rearward and downward from the head pipe 17, a central frame portion 18 a at the rear of the main frame 18 extends vertically downward, and a pivot 19 is provided in the middle. The rear wheel 15 is supported at the rear end portion of the swing arm 20 supported so as to be swingable around the pivot 19.

  As shown in FIG. 2, the parallel multi-cylinder engine 12, for example, a four-cylinder engine, is provided with a cylinder assembly 23 inclined to the front of the vehicle at a required angle in front of the upper part of the crankcase 22. The cylinder assembly 23 is integrally configured by sequentially assembling a cylinder 24, a cylinder head 25, and a head cover 26. The crankcase 22 is configured such that an upper case 22a and a lower case 22b can be divided vertically. In FIG. 1, reference numeral 27 denotes a fuel tank, and reference numeral 28 denotes a vehicle seat.

  As shown in FIGS. 2 and 3, a starter motor 30 and a water pump 31 for circulating cooling water are installed in the vehicle body width direction behind the cylinder 24 of the engine 12 and on the upper case 22 a of the crankcase 22. An engine starting device 34 is configured as an engine starting system from the starter motor 30 and the starting gear train. The motor shaft 33 of the starter motor 30 protrudes toward the vehicle center line CL, and is connected to and connected to a rotation-free primary driven gear 36 provided on the counter shaft 35 via an engine starting system 34. The engine starting system 34 is disposed obliquely above the vehicle front side of the counter shaft 35.

  Specifically, the motor shaft 33 of the starter motor 30 is connected to the starter clutch shaft 39 via a multistage, for example, two-stage reduction gear 37 and a one-way clutch 38, and the starter drive gear 40 of the starter clutch shaft 39 is primary driven. The gear 36 meshes with a start-driven gear 41 provided on the inner side in the vehicle body width direction (vehicle center line CL side). The first-stage reduction mechanism 37 a is a mesh between the motor spline shaft of the motor shaft 33 and the starter idle driven gear, and the second-stage reduction mechanism 37 b is a one-way on the drive gear of the starter idle shaft 43 and the starter clutch shaft 39. The clutch 38 is meshed with an integrated driven gear. The reduction gear 37 is covered with a gear cover case 42 that is integral with the upper case 22 a of the crankcase 22. The water pump 31 is coaxial with the one-way clutch 38 and is disposed behind the cylinder 24 on the left side of the engine 12.

  In the parallel multi-cylinder engine 12, as shown in FIG. 3, a primary drive gear 46 is formed on one crank web 45 of the engine crank 44, and the primary drive gear 46 meshes with the primary driven gear 36. It constitutes the primary gear of the engine drive system. When the push rod 47 is operated and the multi-plate clutch mechanism 48 is turned ON, the engine driving force from the primary drive gear 46 is transmitted to the counter shaft 35 via the primary driven gear 36 and the multi-plate clutch mechanism 48, and this The transmission gear 49 on the counter shaft 35 and the transmission gear (not shown) of the drive shaft 50 are selected by the transmission 53 including the shift cam 51 and the shift fork 52 shown in FIG.

  As shown in FIG. 1, the drive sprocket 54 on the left side of the vehicle is transmitted to the driven sprocket 56 on the rear wheel shaft via the drive chain 55 on the drive shaft 50, and the rear wheel 15 is driven.

  On the other hand, when the engine is started, as shown in FIG. 3, when the starter motor 30 of the engine starter 34 is started, the motor drive force is supplied to the starter drive gear 40 via the speed reducer 37 and the one-way clutch 38 of the engine starter 34. The engine 12 is started by being transmitted from the start driven gear 41 to the crankshaft 44 through the primary gears 36 and 46 and rotating the engine crank 44.

  When the engine 12 is started, the driving force of the engine 12 is transmitted from the crank shaft 44 to the counter shaft 35 through the primary drive gear 46, the primary driven gear 36 and the multi-plate clutch mechanism 48, and then from the counter shaft 35 to the mission. It is transmitted to the drive shaft 50 via the transmission device 53 of the gear 49 and transmitted to the rear wheel 15 via the drive chain 55 to drive the rear wheel 15.

  Further, as shown in FIGS. 3 and 4, the drive shaft 58 of the water pump 31 is connected to the starter motor 30 on the starter clutch shaft 39 constituting the intermediate shaft of the engine starting system 34 from the starter motor 30. The water pump 31 is provided outside the starter motor 30 in the vehicle body width direction on the upper case 22 a of the crankcase 22. As shown in FIG. 2, the water pump 31 is provided above the upper case 22 a of the crankcase 22 on the vehicle rear side of the cylinder 24 of the cylinder assembly 23.

  As shown in FIG. 2, the water pump 31 is connected to a cooling water hose 61 from the radiator 60 on the pump suction port 62 side, and the pump discharge port 63 side is connected to the water jacket of the cylinder assembly 23 via the cooling water hose 64. 66. Cooling water discharged by driving the pump of the water pump 31 is discharged to the water jacket 66 of the cylinder assembly 23, cools the inside of the cylinder 24 and the cylinder head 25, rises in temperature, and is sent to the radiator 60 to cool the engine 12. On the other hand, after the engine 12 is cooled, it is cooled by the radiator 60. The cooling water hoses 61 and 64 are arranged on the left side of the cylinder 24 and connect the water pump 31 to the cylinder 24 and the radiator 60.

  On the other hand, the lower case 22b of the crankcase 22 is provided with an oil pan 69 in which lubricating oil 68 is stored. An oil strainer 70 extends into the lubricating oil 68 stored in the oil pan 69. The stored lubricating oil 68 is lubricated by the oil pump 71 from the oil strainer 70 through an oil gallery (not shown). To be supplied to the department. The oil pump 71 is connected to the drive shaft 50 via a sprocket / chain mechanism 73, and is driven by a rotational drive of the drive shaft 50.

  In the parallel four-cylinder engine 12 according to the present embodiment, the water pump 31 is disposed behind (on the back of) the cylinder 24 of the cylinder assembly 23 and on the upper case 22 a of the crankcase 22. Unlike what is provided on the lower outside of a nearby crankcase, a sufficient bank angle of the vehicle can be secured.

  Further, since the water pump 31 is rotationally driven using the always rotating shaft (intermediate shaft starter clutch shaft 39) of the engine starting system 34, an independent sprocket / chain mechanism for driving the water pump 31 is not required. On the other hand, the piping length of the cooling water hoses 61 and 64 from the water pump 31 to the radiator 60 can also be shortened. Therefore, the weight of the engine 12 and the flow path resistance can be reduced, and the amount of cooling water can be reduced.

  Further, the water pump 31 can be always driven independently from the oil pump 71 on a separate shaft, and the water pump 31 and the oil pump 71 can be driven by setting the optimum reduction ratio individually, so that lubrication is possible. Efficiency and cooling efficiency can be improved. In addition, since the water pump 31 is installed on the upper case 22a of the crankcase 22, there is no need to install a water pump on the outer left side of the crankcase on the lower left side of the engine as in the conventional motorcycle. The degree of freedom in the layout of the gear shift parts can be increased, and the shift feeling can be improved.

  In the description of the embodiment of the present invention, the example in which the pump drive shaft of the water pump is provided coaxially with the one-way clutch 38 (intermediate shaft 39) of the engine start system has been described, but the pump drive shaft of the water pump is the engine. Any device that uses a part of the starting system may be used. Any one of the intermediate shafts of the engine starting system and the pump drive shaft of the water pump may be coaxial, and may be coaxial with, for example, a starter idle gear shaft other than the starter clutch shaft. In this case, the one-way clutch may be provided on the starter idle gear shaft of the intermediate shaft.

  DESCRIPTION OF SYMBOLS 10 ... Motorcycle, 11 ... Vehicle body, 12 ... Engine, 13 ... Front wheel, 14 ... Steering handle, 15 ... Rear wheel, 17 ... Head pipe, 18 ... Main frame, 19 ... Pivot, 20 ... Swing arm, 22 ... Crankcase, 23 ... Cylinder assembly, 24 ... Cylinder, 25 ... Cylinder head, 26 ... Head cover, 27 ... Fuel tank, 28 ... Vehicle seat, 30 ... Starter motor, 31 ... Water pump, 33 ... Motor shaft (motor spline shaft) 34 ... Engine start system, 35 ... Counter shaft, 36 ... Primary driven gear, 37 ... Reduction gear, 38 ... One-way clutch, 39 ... Starter clutch shaft (intermediate shaft), 40 ... Start drive gear, 41 ... Start driven gear, 43 ... Starter idle shaft (intermediate shaft), 45 ... Crank web, 46 ... Primary drive gear, 47 ... push rod, 48 ... multi-plate clutch mechanism, 49 ... mission gear, 50 ... drive shaft, 51 ... shift cam, 52 ... shift fork, 53 ... transmission, 54 ... drive sprocket, 55 ... drive chain, 56 ... Driven sprocket, 58 ... Drive shaft, 60 ... Radiator, 61, 64 ... Cooling water hose, 62 ... Pump suction port, 63 ... Pump discharge port, 66 ... Water jacket, 68 ... Lubricating oil, 69 ... Oil pan, 70 ... oil strainer, 71 ... oil pump, 73 ... sprocket / chain mechanism.

Claims (5)

In the engine of a motorcycle in which the cylinder of the engine is provided on the upper front side of the crankcase,
A starter motor that starts the engine and a water pump that circulates cooling water are arranged at the top of the crankcase behind the cylinder,
A motorcycle engine characterized in that a part of an engine starting system from the starter motor is connected to a pump drive shaft of the water pump to drive the water pump. The engine of the motorcycle according to claim 1, wherein the engine start system is connected from the starter motor to a counter shaft via a start gear train and from the counter shaft to an engine crankshaft via a primary gear. . The engine start system includes a reduction gear mechanism having a multi-stage start gear train and is connected from a start drive gear for the intermediate shaft to a start driven gear for the counter shaft,
The engine of the motorcycle according to claim 1 or 2, wherein a drive shaft of the water pump is connected to the intermediate shaft. The motorcycle engine according to claim 3, wherein a one-way clutch is provided in a final reduction gear mechanism of the engine starting system. The starting drive gear provided on the intermediate shaft meshes with the starting driven gear provided on the inner side in the vehicle width direction of the primary driven gear of the counter shaft,
The motorcycle engine according to claim 3, wherein the intermediate shaft is provided in a vehicle width direction coaxially with a pump drive shaft of the water pump.

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