JP2632349B2 - Driving mechanism for auxiliary equipment of internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a drive mechanism for an accessory of an internal combustion engine that drives the accessory by an output of an engine crankshaft transmitted via a timing belt.

(Prior Art) In recent years, in vehicles such as motorcycles, an engine and
Auxiliary equipment (lubricating oil pump,
It is desired to optimize the layout of the cooling water pump and the like so that the volume of the entire engine drive type is as small as possible. In order to meet such a demand, for example, a cam shaft disposed in each of two banks of a V-type internal combustion engine is driven by one timing belt, and an auxiliary machine (V) is provided in a valley of the V-type internal combustion engine. A compact V-type multi-cylinder engine in which a cooling water pump (for example, a cooling water pump) is provided and the auxiliary machine is driven behind the timing belt is known from Japanese Patent Application Laid-Open No. 62-93432.

By the way, a vehicle is equipped with a generator driven by rotation of a crankshaft. The generator is usually rotated by a generator drive belt wound around a crankshaft, and the generator can be arranged in an appropriate space by using the belt. However, the generator is significantly larger in weight and volume than the other accessories, so that the generator itself is rotated in the rotational direction at the mounting position by its operation. Therefore, in the configuration in which the generator is directly rotated by the drive belt wound around the crankshaft as described above, the rotation direction of the generator matches the rotation direction of the crankshaft, and the engine body is rotated in the rotation direction. Rotational displacement gives an impact to the vehicle body. The impact of this impact on the vehicle body is significant when the V-type internal combustion engine is mounted on a motorcycle having no engine mount. In particular, when the crankshaft of the V-type engine is mounted so as to be parallel to the traveling direction of the motorcycle (a so-called vertical type), the impact is applied in the left-right direction with respect to the traveling direction of the vehicle body. Will not be maintained.

Furthermore, since the camshaft, the timing belt for driving the auxiliary equipment such as the cooling water pump, and the belt for driving the generator are both wound around the same crankshaft protruding portion from the engine, the timing belt is driven. It is necessary to increase the length of the protruding portion, and it is not possible to meet the above-mentioned demand for reducing the volume of the engine drive system as much as possible to achieve a compact engine.

For this reason, conventionally, a gear is provided on the driven shaft of the generator and the crankshaft so that the rotation direction of the generator is opposite to the rotation of the crankshaft, and these two gears are meshed, and the rotation of each A device that reverses the generated rotational displacement in the opposite direction to cancel the above-described impact on the vehicle body, that is, while using a generator as a torque balancer with respect to a crankshaft and also reducing the volume of the engine drive system, for example, It is known from JP-A-51-31420.

(Problems to be Solved by the Invention) However, in the conventional device using the above-mentioned gears, there is a limit to the size of a radius that the gears meshing with each other can take, so that the place where the generator can be installed is limited. There are inconveniences. Further, since the mass of the rotating member in the generator is large, when the generator is rotated by the crankshaft via the gear, a torque shock is applied to the crankshaft when the generator starts rotating. Therefore, when a gear is used, a separate damper device for obtaining a damper effect is required as compared with the case where a drive belt is used, and the engine drive system becomes complicated and the engine cannot be made compact. There is.

(Object of the Invention) The present invention has been made in view of the above circumstances, and uses the rotation of a generator as a torque balancer for the rotation of a crank shaft, and also achieves simplification and downsizing of a drive system of an engine. It is an object of the present invention to provide a drive mechanism for an auxiliary device of an internal combustion engine, which can perform the following.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an internal combustion engine that drives a driven pulley of an auxiliary machine at the back of a timing belt that transmits power from a crankshaft of the internal combustion engine to a valve operating camshaft. In the accessory drive mechanism, a drive pulley that rotates integrally with the driven pulley is provided coaxially with the driven pulley, and a generator as an accessory of the engine is driven by a drive belt wound around the drive pulley. Provided is a drive mechanism for a generator of an internal combustion engine of a small vehicle such as a motorcycle.

Further, a driving pulley provided coaxially with the driven pulley and provided to rotate integrally with the driven pulley is disposed between the driven pulley and an auxiliary device driven by the driven pulley. The present invention provides a driving mechanism for a generator of an internal combustion engine.

(Operation) As described above, the driven shaft of the generator rotates in the same direction as the driven pulley of another accessory driven by the back surface of the timing belt, so that the generator rotates in the opposite direction to the crankshaft. Thus, it works as a torque balancer for the crankshaft. Further, since the driven shaft of the generator is rotated by the drive belt, a desired damper effect required for starting rotation of the driven shaft is obtained, and the position where the generator can be mounted is widened. In addition, by applying the drive mechanism to a V-type internal combustion engine having a V bank, the arrangement of various accessories of the engine using the V bank becomes more flexible.

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

FIG. 1 is a partially cutaway side view of a motorcycle equipped with an accessory drive mechanism according to the present invention, in which 1 indicates a vehicle body (frame).

A front fork 2 is attached to a head tube 1a at a front end of the vehicle body 1 so as to be steerable and rotatable by a handle 3, and a front wheel 4 is rotatably supported by the front fork 2. An engine 5 is mounted on a lower front portion of the vehicle body 1. The engine 5 includes a crankshaft shown in FIG.
Reference numeral 18 denotes a vertical V-type internal combustion engine arranged so as to be parallel to the traveling direction of the vehicle body. The engine 5 of the vehicle body 1
An air cleaner 6 indicated by a broken line is arranged at the upper part of the transmission, a transmission 7 is arranged at a lower rear part, and a fuel tank 8 is arranged at an upper rear part as shown by a broken line. On the other hand, a generator 9 which is one of engine accessories is arranged below the engine 5 and in front of the transmission 7. The engine 5
1 (left side in FIG. 1), an accessory drive mechanism 10 according to the present invention for driving an engine accessory such as the generator 9 by rotation of a crankshaft 18 of the engine 5 is provided.

A rear fork 11 is swingably supported on the rear side of the vehicle body 1, and the rear end of the rear fork 11 is joined to a final drive case 12. A drive shaft (not shown) is rotatably mounted in the rear fork and the final drive case 12 in the axial direction so as to be rotatable in the axial direction. Is further transmitted to drive wheels (rear wheels) 13 via final driven gears (not shown) in final drive case 12.

Next, the structure of the accessory drive mechanism 10 and the arrangement of various accessories of the engine will be described in detail. FIG. 2 is a front view of a main part of the accessory drive mechanism 10 as viewed from the front (left side in FIG. 1) of the vehicle. The V-type internal combustion engine 5 includes a right bank 14a and a left bank 14b arranged in a V-shape, and both banks 14a and 14b are integrally formed in one housing 15. The banks 14a, 14b are provided with intake pipes 16a, 16b and exhaust pipes 17a, 17b so as to communicate with respective cylinders (not shown) of the banks. A crankshaft 18 is arranged in a housing 15 of the engine 5 at a position corresponding to an intersection of the two banks 14a and 14b. The crankshaft 18
Protrudes through the front end face of the housing 15, and a crank pulley 19 is fixed to an end of the protruding crank 18 so as to rotate integrally with the crankshaft.

The accessory drive mechanism 10 has a pulley groove of the crank pulley 19.
A timing belt 101 of both teeth type wound around 19a, cam pulleys 102a and 102b for a timing belt fixed to the ends of the cam shafts 20a and 20b of the banks 14a and 14b, and a cooling water pump to be described later. A driven pulley 103 fixed to the rotating shaft 21a of 21 and wound around the back surface of the timing belt, a driven pulley 104 that rotates integrally on the same axis as the driven pulley,
The pulley 105 of the generator, which is integrally fixed to the rotating shaft 9a of the generator 9 so as to be rotatable, and the pulley groove of the drive pulley 104
A one-tooth drive belt 106 wound around 104a and a pulley groove 105a of the generator pulley 105, and a timing belt 101
And belt tensioners 107 and 108 for pressing the drive belt 105 from the back, respectively.

The engine 5 is provided with a cooling water pump 21 as shown in FIGS.
As shown in the figure, the V-bank is formed integrally with the housing 15 of the engine body on the right side of the center line of the crankshaft between the valleys in the figure. The pump 21 has a shaft 21a, a bearing 21b, an impeller 21
c and the like, and the drive pulley 104 and the driven pulley are sequentially mounted on the shaft 21a from the engine body side (from above in FIG. 3).
103 is integrally fixed.

Further, in the illustrated embodiment, the generator 9 is arranged on the same side as the cooling water pump with respect to the center line of the crankshaft 18, that is, closer to the left bank than the crankshaft, and biased rearward with respect to the signal direction of the vehicle. The position between the front surface of the housing 15b on the side of the shifted left bank 14b (the lower end surface of the housing 15 in FIG. 3) and the plane on which the timing belt 101 is disposed (the position of the timing belt indicated by a broken line in FIG. 3). A drive belt 106 for driving the generator 9 is provided (a drive belt position indicated by a broken line in FIG. 3).

Next, the operation of the accessory drive mechanism 10 having the above configuration will be described.

First, when the crankshaft 18 rotates clockwise in FIG. 2, the cam pulleys 102a and 102a
2b is driven in a clockwise direction, rotates in synchronization with the cam 18, and an intake valve and an exhaust valve (both not shown) arranged in each cylinder in each bank 14a, 14b are driven. At this time, the driven pulley 103 of the cooling water pump 21 is simultaneously driven and rotated in a direction opposite to the crankshaft 18 (counterclockwise in FIG. 2) by the arrangement of the timing belt 101. The rotation of the driven pulley 103 rotates the emperor 21c of the cooling water pump 21 to cool the engine 5. On the other hand, when the driven pulley 103 is rotated, the driving pulley 104 formed integrally with the driven pulley 103 drives the generator pulley 105 counterclockwise in FIG. As a result, the generator 9 always rotates in the direction opposite to the rotation direction of the crankshaft 18, and the generator 9 also functions as a torque balancer for the engine 5.

Incidentally, the V-type internal combustion engine generally has, as shown in FIG. 3, center lines l ₁ and l _{2 of} cylinders included in the right bank 14a.
And a cylinder included in the left bank 14b centers l _3, l ₄ and is l ₁ to l ₃ in (this embodiment the cylinder of each bank are arranged to rub the axial direction by a predetermined phase of the crankshaft Between and l ₂
Offset between ₄ to l are both made as d. Accordingly, as shown in the illustrated embodiment, the auxiliary drive mechanism 10 of the present invention is configured such that both the cooling water pump 21 and the generator 9 are closer to the left bank 14b than the center line of the crankshaft (the right bank is closer to the traveling direction of the vehicle than the left bank). If it is deviated backward, it is closer to the right bank) to arrange the housing 1 on the left bank 14b side.
A driving belt 106 for the generator is arranged between the front surface of the housing 5b (the lower end surface of the housing 15 in FIG. 3) and the plane on which the timing belt 101 is arranged (the position of the timing belt indicated by a broken line in FIG. 3). As a result, the position of the drive system of the generator 9 can be secured without increasing the volume occupied by the entire engine.

In this embodiment, a double toothed belt is used as the timing belt 101, but a single toothed belt may be used.

(Effects of the Invention) As described above, the drive mechanism of the accessory of the internal combustion engine of the present invention transmits the power of the internal combustion engine from the crankshaft to the valve cam shaft through the timing belt to drive the valve cam shaft, And a driving mechanism for rotating a driven pulley of an auxiliary machine by a back surface of the timing belt, wherein a driving pulley that rotates integrally with the driven pulley is formed coaxially with the driven pulley, and the rotation of the driving pulley is driven. Since the power is transmitted to the driven side of the generator via the belt, the rotation direction of the generator is opposite to the rotation direction of the crankshaft so that the generator acts as a torque balancer for the engine. The engine vibration is reduced. This effect is particularly remarkable when the drive mechanism is applied to a motorcycle in which a V-type internal combustion engine 9 that requires an anti-torque balancer is installed vertically. Furthermore, the generator can be installed at a desired position by changing the length of the drive belt wound around the generator. In particular, when the drive mechanism is applied to a vehicle equipped with a V-type internal combustion engine, a compact engine drive system that effectively utilizes a space unique to the V-type engine, which is generated by a phase difference between the left and right banks in the axial direction, is configured. Further, the operation of the generator can be started smoothly without separately providing a damper device by the damper effect of the drive belt.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a motorcycle employing an accessory drive mechanism according to the present invention, FIG. 2 is an explanatory view of a main part showing the accessory drive mechanism of FIG. 1, and FIG. FIG. 3 is a plan view of the drive mechanism of FIG. 5 V-type internal combustion engine, 9 generator, 10 drive mechanism, 14a right bank, 14b left bank, 18 crankshaft, 19 crank pulley, 21 engine cooling water Pump, 101 timing belt, 103 driven pulley, 104 drive pulley, 105 generator pulley, 106
... the drive belt.

Claims (3)

(57) [Claims] An accessory drive mechanism for an internal combustion engine that drives a driven pulley of an auxiliary machine behind a timing belt that transmits power from a crankshaft of the internal combustion engine to a valve operating camshaft. A driving pulley that rotates integrally with the pulley, and a driving belt that is wound around the driving pulley drives a generator that is an auxiliary device of the engine, thereby generating power of the internal combustion engine in a small vehicle such as a motorcycle. Drive mechanism of the machine. 2. A driving pulley which is provided coaxially with the driven pulley so as to rotate integrally with the driven pulley, is disposed between the driven pulley and an accessory driven by the driven pulley. The driving mechanism for a generator according to claim 1, wherein: 3. The internal combustion engine according to claim 1, wherein the internal combustion engine is a V-type engine, and a cam shaft disposed in each of two banks is driven by one timing belt. The drive mechanism of the generator.