JP2005321054A - Power transmission device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat radiation performance of a power generator incorporated in an engine power transmission device. <P>SOLUTION: This power transmission device comprises a belt type continuously variable transmission provided with a primary pulley 37, and a power generator 58, which are incorporated in a case. In the primary pulley 37, a fan blade 71 is provided to generate air currents in a transmission chamber 30 in accordance with its rotation, so that outside air flows through an outside air introducing duct 72 into the transmission chamber 30. Air flowing into the transmission chamber 30 flows through a first cooling air passage 76 into an ignition magneto chamber 57 to rotate in it, and then return through a second cooling air passage 79 into the transmission chamber 30. The power generator 58 stored in the ignition magneto chamber 57 can thus be cooled in spite of its being large in capacity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an engine power transmission device that transmits engine power to drive wheels via a continuously variable transmission.

  Roughly terrain vehicles or all-terrain vehicles, or ATVs, also known as buggy vehicles, are four-wheeled single-seater off-road vehicles that can be used for leisure purposes such as hunting and trail touring, and in some cases as agricultural utility vehicles. It's being used. Such a power transmission device for transmitting engine power of an all-terrain vehicle to a drive wheel includes a crankshaft driven by the engine, and a belt-type continuously variable input of rotation of the crankshaft via a centrifugal clutch. And a transmission. The belt-type continuously variable transmission has an input shaft-side primary shaft to which a primary pulley is mounted and an output-side secondary shaft to which a secondary pulley is mounted. Engine power is transmitted from the shaft to the secondary shaft.

The continuously variable transmission is built in the case to prevent rain and snow from entering it, and has a waterproof structure. A fan blade is provided on the pulley, and the continuously variable transmission is cooled by generating an air flow with the fan blade and taking in the cooling air from the outside of the case and then discharging it outside (see Patent Document 1).
Japanese Patent Laid-Open No. 11-11171

  The power transmission device is equipped with a generator for charging the battery, and the power transmission device for ATV is a magnet generator using a permanent magnet as a field, that is, a magneto, which is used as a generator. In order to make it waterproof, it is built into the case and sealed. For this reason, when the power generation capacity of the generator increases, the temperature of the magneto chamber that houses the generator becomes high due to the heat generated by the generator. The magneto chamber is adjacent to the crank chamber, and if the magneto chamber becomes hot, it will adversely affect the cooling performance of the engine, so it is necessary to improve the cooling performance of the generator to achieve a larger generator. There is.

  The objective of this invention is improving the heat dissipation of the generator integrated in an engine power transmission device.

  Another object of the present invention is to make it possible to mount a large-capacity generator by improving the heat dissipation of the generator.

  A power transmission device for an engine according to the present invention includes a belt-type continuously variable transmission that is driven by a crankshaft and is incorporated in a case having a primary shaft on which a primary pulley is mounted, and is driven by the crankshaft and incorporated in the case An engine power transmission device for transmitting engine power to drive wheels via the continuously variable transmission, in accordance with the rotation of the primary shaft in the transmission chamber that houses the continuously variable transmission. The primary pulley is provided with fan blades for generating an air flow, and the case is provided with an outside air introduction duct that communicates with an opening formed in a low pressure side portion of the transmission chamber and introduces outside air into the transmission chamber. A first cooling air passage that communicates the intake opening that opens to the high-pressure side of the transmission chamber and the blowout opening that opens to the magneto chamber that houses the generator Provided in the case is a second cooling air passage that is provided in the case and communicates with a return port that opens into the magneto chamber and discharges cooling air that has flowed through the magneto chamber, and a discharge port that opens into the transmission chamber. It is characterized by.

  In the engine power transmission device according to the present invention, the discharge port is provided in the vicinity of the opening, and is sucked into the cooling air in the second cooling air passage by the cooling air flowing into the transmission chamber from the outside air introduction duct. It is characterized by applying force. In the engine power transmission device according to the present invention, the belt type continuously variable transmission is disposed on one end side of the crankshaft via a centrifugal clutch, and the generator is disposed on the other end side of the crankshaft. It is characterized by doing.

  According to the present invention, a part of the air flow generated in the transmission chamber by the fan blade provided in the primary pulley of the continuously variable transmission is guided into the magneto chamber containing the generator. Can be cooled, the engine adjacent to the magneto chamber can be prevented from being heated, and the heat dissipation performance of the generator can be improved. Since the heat dissipation of the generator is improved, a large-capacity generator can be mounted on the power transmission device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an example of an ATV, which is also called a buggy vehicle, that is, an all-terrain vehicle. The vehicle body 1 is provided with front wheels 2a and 2b and rear wheels 3a and 3b. It is provided at the center of the vehicle body 1. An occupant seated in the seat 4 travels by operating the handle 5.

  2 is a schematic view showing a power transmission device mounted on the all-terrain vehicle shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line AA in FIG. As shown in FIG. 2, a crankshaft 12 is rotatably mounted on the crankcase 11 assembled by abutting the first case body 11a and the second case body 11b, and the engine 13 is mounted as shown in FIG. It is attached. As shown in FIG. 3, the engine 13 has a cylinder 14 fixed to the crankcase 11 and a cylinder head 15 fixed to the upper end of the cylinder 14. A piston 16 is incorporated in a cylinder bore formed in the cylinder 14 so as to freely reciprocate, and a connecting rod 18 is interposed between the piston 16 and the crankpin 17 fixed to the crankshaft 12 at a position eccentric from the center of rotation. The crankshaft 12 is driven to rotate by the engine 13.

  As shown in FIG. 3, the cylinder head 15 is formed with an intake port 21 a that opens into the combustion chamber 19, and an intake valve 22 a for opening and closing the intake port 21 a is attached to the cylinder head 15. The cylinder head 15 has an exhaust port 21b that opens into the combustion chamber 19, and an exhaust valve 22b for opening and closing the exhaust port 21b is mounted on the cylinder head 15. A camshaft 23 is rotatably mounted on the cylinder head 15, and a rocker arm 24a for opening / closing the intake valve 22a and an exhaust valve 22b for opening / closing the rocker shaft 24 provided in parallel therewith. The rocker arm 25b is rotatably mounted. As shown in FIG. 2, a sprocket 26 is fixed to the crankshaft 12, and a timing chain (not shown) is spanned between a sprocket (not shown) fixed to the camshaft 23, and an intake valve 22 a The exhaust valve 22b is driven to open and close at a predetermined timing through the camshaft 23 and the rocker arms 25a and 25b as the crankshaft 12 rotates.

  As shown in FIG. 2, a transmission case 31 assembled by abutting two case bodies 31 a and 31 b is attached to the crankcase 11, and the transmission chamber 30 formed by the transmission case 31 has an inside. A belt type continuously variable transmission 32 is incorporated. The continuously variable transmission 32 is coaxial with the crankshaft 12 and is rotatably mounted in the transmission case 31 and in the transmission case 31 in parallel with the primary shaft 33. The primary shaft 33 is connected to a clutch drum 36 of a centrifugal clutch 35 incorporated between the primary shaft 33 and the crankshaft 12, and is connected to the crankshaft 12 via the centrifugal clutch 35. It is coaxially disposed on the crankshaft 12 on one end side.

  A primary pulley 37 having a variable groove width is assembled to the primary shaft 33, and the primary pulley 37 is fixed to the primary shaft 33 and rotates integrally with the primary shaft 33, and moves in the axial direction with respect to the primary shaft 33. The movable pulley 37b is freely assembled and rotated integrally with the primary shaft 33. A secondary pulley 38 with a variable groove width is assembled to the secondary shaft 34, and the secondary pulley 38 is fixed to the secondary shaft 34 and moves in the axial direction with respect to the secondary shaft 34 and a fixed pulley 38 a that rotates integrally therewith. A movable pulley 38b that is freely assembled and rotates integrally with the secondary shaft 34 is configured. Between these pulleys 37 and 38, a rubber V-belt 39 is stretched. When the winding diameter of the V-belt 39 around the primary pulley 37 and the secondary pulley 38 changes, the primary shaft 33 does not rotate. The gear ratio changes in stages and is transmitted to the secondary shaft 34. A plurality of columnar centrifugal weights 42 are mounted on the primary pulley 37 so as to be perpendicular to the rotation center of the primary shaft 33 by cam plates 41 fixed to the primary shaft 33. In order to apply a tightening force to the V-belt 39, a compression coil spring 43 is mounted.

  Therefore, when the rotation speed of the primary shaft 33 becomes high with the crankshaft 12 rotating at a predetermined speed or higher and the primary shaft 33 and the crankshaft 12 are fastened via the centrifugal clutch 35, the centrifugal weight is increased. 42 moves outward in the radial direction by the centrifugal force applied thereto, the groove width of the primary pulley 37 is narrowed, and the winding diameter of the pulley 37 is increased. As a result, the groove width of the secondary pulley 38 expands against the spring force, the winding diameter of the V belt 39 around the secondary pulley 38 is reduced, and the gear ratio of the continuously variable transmission 32 changes to the high speed stage side.

  As shown in FIG. 2, a gear case 44 is assembled to the transmission case 31, and a secondary shaft 34 is supported on the gear case 44, and an output shaft 45 is rotatably mounted in parallel with the secondary shaft 34, Further, an axle 46 is rotatably mounted parallel to the output shaft 45, and the axle 46 is directly connected to the rear wheels 3a and 3b shown in FIG. Between the secondary shaft 34 and the output shaft 45, there is provided a forward rotation gear train 47 including a gear integrally provided on the secondary shaft 34 and a gear rotatably mounted on the output shaft 45. A reverse gear train 48 is provided which includes a gear integrally provided on the shaft 34, a gear rotatably mounted on the output shaft 45, and an idler gear (not shown) meshing with the gear.

  In order to switch the rotation direction of the output shaft 45 between the forward rotation direction and the reverse rotation direction, a forward / reverse switching mechanism 49 is mounted on the output shaft 45. As shown in FIG. 2, the forward / reverse switching mechanism 49 has switching disks 51a and 51b that respectively mesh with splines provided on the output shaft 45, and these switching disks 51a and 51b are connected to the output shaft 45 in the axial direction. It is slidably mounted. When the switching disk 51a is engaged with the gear train 47, the rotation of the secondary shaft 34 is transmitted in the forward direction to the axle 46 and the vehicle moves forward. On the other hand, when the switching disk 51b is engaged with the gear train 48, the rotation of the secondary shaft 34 is transmitted in the reverse direction to the axle 46 and the vehicle moves backward.

  As shown in FIG. 2, a balancer shaft 52 is rotatably mounted on the crankcase 11 in parallel with the crankshaft 12, and the balancer shaft 52 is connected to the crankshaft 12 through a gear train 53. A balance weight 54 is integrally provided on the balancer shaft 52, and is connected to a rotor of an oil pump 55 mounted on the crankcase 11. The lubricating oil discharged from the oil pump 55 is slid in the power transmission device. The moving part is supplied through an oil passage (not shown).

  As shown in FIG. 2, a power generator case 56 is attached to the crankcase 11, and a magnet, that is, a magnet generator 58 is placed in a magnet chamber 57 defined by the power generator case 56 and the crankcase 11. It is installed. The generator 58 includes an outer rotor 59 having a permanent magnet and attached to the crankshaft 12, and a stator 60 having an iron core around which a coil is wound and fixed to the crankcase 11. Therefore, when the engine 13 is driven and the crankshaft 12 rotates, the electric power generated by the generator 58 is charged in a battery (not shown). The generator 58 is coaxially disposed on the opposite side of the crankshaft 12 with respect to the primary shaft 33.

  The crankcase 11, the transmission case 31, the gear case 44, and the power generator case 56 form a case for housing the above-described members for constituting the power transmission device. By attaching this case to the vehicle body, the power transmission device is Mounted on the car body.

  In order to start the engine, a starter 61 is mounted in the magneto chamber 57, and this starter 61 is driven by an electric motor 62 attached to the crankcase 11. A recoil starter 63 is mounted in the magneto chamber 57 in order to start the engine 13 manually when the charge amount of the battery is insufficient and the engine 13 cannot be started by the starter 61. The recoil starter 63 has a recoil pulley 64 around which a recoil rope is wound. When the recoil rope 64 is pulled and the recoil pulley 64 is rotated, the crankshaft 12 rotates and the engine 13 can be started manually.

  4 is a partially cutaway plan view of FIG. 3, FIG. 5 is a sectional view taken along line BB in FIG. 4, and FIG. 6 is a sectional view taken along line CC in FIG. As shown in FIGS. 2 and 4, fan blades 71 are provided on the outer surface of the fixed pulley 37 a of the primary pulley 37, and the outer surface of the fixed pulley 37 a is a blower fan. An air flow is generated inside. The crankcase 11 is provided with an outside air introduction duct 72 for introducing outside air into the transmission chamber 30 as shown in FIGS. 4 and 5, and this outside air introduction duct 72 is an opening 73 formed in the transmission case 31. Communicating with When the primary pulley 37 rotates in the direction indicated by the arrow D in FIG. 5, the opening 73 is formed in a portion that becomes the air inlet side of the blower fan, that is, the low-pressure side, and with the rotation of the primary pulley 37. As indicated by an arrow E, outside air is introduced into the transmission chamber 30 via the outside air introduction duct 72. The introduced outside air becomes cooling air toward the secondary pulley 38 and cools the inside of the transmission chamber 30 and is then discharged to the outside from an exhaust port (not shown).

  As shown in FIGS. 4 and 5, the transmission case 31 is formed with an air intake port 74 that opens into the transmission chamber 30, and the crankcase 11 is connected to the magneto chamber 57 corresponding to the intake port 74. An air outlet 75 for opening air is formed, and the crankcase 11 is provided with a first cooling air passage 76 that allows the intake 74 and the outlet 75 to communicate with each other. The intake port 74 is formed in the high-pressure side portion, which is downstream of the air flow generated by the fan blade 71 with respect to the opening portion 73, and a part of the cooling air pressurized by the fan blade 71 is the first cooling. It flows into the magneto chamber 57 through the air passage 76. The cooling air that has flowed into the magneto chamber 57 from the outlet 75 rotates in the direction indicated by the arrow G in the same direction as the outer rotor 59 rotates in the direction indicated by the arrow F in FIG. The inside of the magneto chamber 57 is cooled.

  An air return port 77 that opens to the downstream side of the swirl flow of the magneto chamber 57 and discharges the cooling air from the magneto chamber 57 is formed in the crankcase 11 as shown in FIGS. The transmission case 31 is formed with an air discharge port 78 that opens into the transmission chamber 30, and the crankcase 11 is connected to the return port 77 and the discharge port 78 as shown in FIG. The cooling air passage 79 is provided. Accordingly, the air swirled in the magnet chamber 57 and cooled therein is returned to the transmission chamber 30 via the second cooling air passage 79 and discharged to the outside. As shown in FIG. 5, the discharge port 78 is provided in the vicinity of the opening 73, and the cooling air introduced from the outside air introduction duct 72 and flowing into the transmission chamber 30 from the opening 73 crosses the discharge port 78. Therefore, a suction force is generated at the discharge port 78 by the ejector action. As a result, air flowing from the first cooling air passage 76 to the second cooling air passage 79 through the magneto chamber 57 due to high-pressure air at the intake port 74 is sucked by the ejector action of the discharge port 78. A force is applied, and a swirling flow of cooling air is surely formed in the magneto chamber 57.

  In this manner, a part of the cooling air flowing in the transmission chamber 30 flows in the magneto chamber 57 formed in a sealed state in the case by the power generator case 56 and the crankcase 11. Can be prevented from affecting the cooling performance of the engine, and the generator 58 accommodated in the magneto chamber 57 can be reliably cooled to improve the heat dissipation of the generator 58. The capacity of the generator 58 can be increased. As the generator 58, not only a magnet generator but also an alternator may be used.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the power transmission device of the present invention, the crankshaft 12 and the primary shaft 33 of the belt-type continuously variable transmission are coaxially arranged, and the centrifugal clutch 35 is mounted between the crankshaft 12 and the primary shaft 33. Although it has a two-shaft configuration, the crankshaft is arranged parallel to the crankshaft and the secondary shaft driven by the crankshaft via the gear train and the secondary shaft are parallel to each other, and the primary shaft is coaxial with the secondary shaft. The present invention can also be applied to an ATV power transmission device having a three-axis configuration.

It is a perspective view which shows an example of the all-terrain vehicle. It is the schematic which shows the power transmission device mounted in the all-terrain vehicle shown by FIG. It is sectional drawing of the direction in alignment with the AA in FIG. FIG. 4 is a partially cutaway plan view of FIG. 3. It is sectional drawing which follows the BB line in FIG. It is sectional drawing which follows the CC line in FIG.

Explanation of symbols

11 Crankcase 12 Crankshaft 31 Transmission case 32 Continuously variable transmission 33 Primary shaft 34 Secondary shaft 35 Centrifugal clutch 37 Primary pulley 38 Secondary pulley 39 V belt 57 Magnet chamber 58 Generator 59 Outer rotor 60 Stator 71 Fan blade 72 Outside air introduction Duct 73 Opening portion 74 Inlet port 75 Outlet port 76 First cooling air passage 77 Return port 78 Discharge port 79 Second cooling air passage

Claims (3)

A belt-type continuously variable transmission which is driven by a crankshaft and has a primary shaft on which a primary pulley is mounted and which is incorporated in a case; and a generator which is driven by the crankshaft and is incorporated in the case. In the engine power transmission device for transmitting to the drive wheels via the continuously variable transmission,
A fan blade that generates a flow of air in association with rotation of the primary shaft is provided in the primary pulley in a transmission chamber that houses the continuously variable transmission,
Provided in the case is an outside air introduction duct that communicates with an opening formed in the low pressure side portion of the transmission chamber and introduces outside air into the transmission chamber;
The case is provided with a first cooling air passage that communicates an intake opening that opens to the high-pressure side of the transmission chamber and a blow-out opening that opens to the magneto chamber that houses the generator,
An engine having a second cooling air passage in the case that communicates a return port that opens to the magneto chamber and discharges cooling air that flows through the magneto chamber and a discharge port that opens to the transmission chamber. Power transmission device.   2. The engine power transmission device according to claim 1, wherein the discharge port is provided in the vicinity of the opening, and cooling air in the second cooling air passage is cooled by cooling air flowing into the transmission chamber from the outside air introduction duct. A power transmission device for an engine characterized by applying a suction force to the engine. The power transmission device for an engine according to claim 1 or 2, wherein the belt-type continuously variable transmission is disposed on one end side of the crankshaft via a centrifugal clutch, and the generator is disposed on the other end side of the crankshaft. An engine power transmission device characterized by being arranged in

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