Clutch Control Device for an Internal Combustion Engine

Field of Invention

The present invention relates to a "Clutch control device for an internal combustion engine" and more particularly to an automated clutch cable actuation mechanism for a motorcycle.

Background of Invention

Motorcycle clutches transmit torque outputted from the engine to the wheel or interrupts transmission of torque. It is provided to engage a motorcycle engine to the transmission mechanism when power transmission to the wheels is needed and to disengage the transmission from the wheels when the motorcycle is to be stopped or during shifting of gears. The clutch comprises of a drive side member and a driven side member. Drive side member and a driven side member are pressed against each other by elastic force of a clutch spring at the time of engaging clutch so that torque of the engine is transmitted from the drive side member to the driven side member. At the time of disengaging clutch, driven side member and drive side member are moved away from each other so that torque transmission from the drive side member is interrupted. The clutch is generally operated through a cable formed by an outer sheath and an inner core that is a cable of the type called the clutch cable. The clutch cable is connected to a manually operated clutch lever pivotally mounted on a handle bar of the motorcycle. An end of the clutch cable is connected to the clutch for actuating the plates of the clutch while an opposite end of the clutch cable is connected to an anchoring point in the pivoting lever. One anchoring point is fixed to only one predetermined position in a cable-connecting portion of the clutch lever. Thus, a predetermined rotation of the clutch lever will always cause the clutch plates to move along the same distance for coupling and uncoupling the clutch. It is well known that the distance along which the clutch plates move varies with the wearing of plates due to use. It is also known that many motorcycle drivers differ as to the best "sensitivity" that such manually operated controls should have. Thus, some motorcyclists prefer "hard" clutch levers while others prefer to use "soft" clutch levers. In addition, some drivers prefer the clutch lever to be moved along an extended arc to cause the clutch plates to be engaged and disengaged while others prefer to have a sudden engagement or disengagement of the plates with a small clutch lever stroke. Moreover, continuous operation of the clutch lever causes fatigue in hands.

Therefore to obviate the defects in the prior art, there is a requirement for a mechanism to control the operation of a clutch in a motorcycle that alleviates the demerits in the prior art in terms of fatigue and individual rider requirements with respect to clutch lever hardness as well as movement.

Summary of Invention

The principal objective of the present invention is to provide an automated clutch cable actuation mechanism for a motorcycle by way of a clutch control device comprising of a clutch control operating means and a clutch cable. The clutch control operating means includes a cable quadrant system, which has a quadrant with an integrated worm wheel. The clutch cable wraps around the quadrant and is pulled when the worm wheel rotates. Rotation to the worm wheel is provided by a motor, which is controlled by a control system. Input to the control system is given by the rider by way of a switch, which is either hand operated or is activated using a hand lever mounted in the proximity of the handlebar. The control system can also be programmed to operate automatically based on inputs received from throttle operation. The present invention utilises the conventional clutch actuation within the engine. Automation of the clutch cable actuation is achieved by the above-described configuration by mimicking the cable pull actuation of the clutch lever.

Hence the present invention, by doing away with the clutch lever, solves the problems in the prior art related to use of clutch lever namely fatigue and individual rider requirements with respect to clutch lever hardness as well as movement. Moreover, the present invention is least complicated and can be quickly integrated on the bike with low risk from a mechanical viewpoint. The flexibility of the clutch cable provides opportunity to remotely mount the clutch control device as per convenience. Further, since there is an opportunity to keep the conventional clutch cable actuation arrangement, an over ride facility in case of system failure can be provided.

These and other features, aspects, and advantages of the present invention will be better understood with reference to the following description, the appended claims and the accompanying drawings. This summary is not intended to limit the scope of the claimed subject matter.

Brief Description of Drawings

The above and other features, aspects, and advantages of the present invention are further illustrated by the accompanying drawings. The drawings are given by way of illustration only and are not limitative of the present invention. A brief description of the drawings is as follows:

Figure 1 shows the side view of a conventional motorcycle.

Figure 2 is a cross sectional view of the power unit of a conventional motorcycle having constant mesh type transmission.

Figure 3 illustrates the configuration of the clutch control device as per the present invention.

Figure 4 shows the motor and an exploded view of the cable quadrant system comprising the clutch control device as per the present invention.

Detailed Description of Invention

A motorcycle 10 as illustrated in Figure 1, includes an engine 41 a front wheel 25, a rear wheel 27, a body frame 19, a fuel tank 56. Body frame 19 includes a head pipe 12, a main tube 17, a down tube 22, and seat rails 18. The head pipe 12 is provided at the front end of body frame 19 to support a steering shaft 11 disposed within head pipe 12. The upper and lower ends of the steering shaft 11 are fixed to an upper bracket 13 and a lower bracked 4 respectively. Upper bracket 13 and lower bracket 14 retain front suspensions 16 that supports front wheel 25. The front wheel 25 is connected at the lower end of the front fork 16, and the upper portion of the front wheel 25 is covered by a front fender 54 mounted to a lower portion of the front fork 16. A : handlebar 15 is fixed to upper bracket 13 and can rotate to both sides. A head light 36 is arranged on an upper portion of the front fork 16. Down tube 22 is located in front of engine 41 and stretches slantingly downward from head pipe 12. A bracket 55 is provided at the lower end of down tube 22 for supporting the engine 41. Main tube 17 is located above engine 41 and stretches rearward from head pipe 12 and connects the rear of the engine 41. A vertical pipe 28 is joined to the rear end of main tube 17 and stretches upward from the point where it joins to main tube 17 to seat rails 18. Seat rails 18 are joined to main tube 17 and stretch rearward to support a seat 57 disposed above seat rails 18. A side stand 58 is arranged on lower portion of engine unit of motorcycle 10. Left and right rear arm bracket portions support a rear arm 26 to swing vertically, and a rear wheel 27 is connected to rear end of the rear arm 26. A rear wheel suspension 34 is arranged between rear arms 26. A tail light unit 64 is disposed on the rear cover 61. A pillion footrest 31 is connected to the vertical pipe 28. A grab rail 62 is also provided on the rear of the seat rails 18. Rear wheel 27 is arranged below seat and rotates by the driving force of engine transmitted through the transmission system.

The transmission system as illustrated in Figure 2 is a constant mesh type transmission. Power of the power unit is transmitted from the crankshaft through a clutch c, and then through the transmission system and further through a counter, shaft g projecting from the rear portion of the crankcase. A main shaft d and a counter shaft g are rotatably supported by the crankcase and are provided with a plurality of paired constant mesh type gears e&f. The mesh type gears on the main shaft d and the counter shaft g are either relatively non-rotatably mounted or rotatably mounted. In shifting the transmission gears a shifting mechanism including a gear shift pedal, a gear shift arm i, shift pins ], a shift drum k and gear shift forks m and a shifter splined with one shaft is axially moved toward the rotatable transmission gear on that shaft so that the rotatable transmission gear is integrated to that shaft. Further the integrated transmission gear is meshed with the corresponding transmission gear on the other shaft and accordingly counter shaft g is rotated relative to the main shaft d at a speed determined by the gear ratio between the transmission gears. One end of the counter shaft g in the rear portion of the crank case projects outwardly from the crank case. A rear wheel drive sprocket h is attached to this end of the counter shaft g. The rear wheel 27 is drivingly rotated by the rear wheel drive chain wound between the rear wheel drive sprocket h and the rear wheel driven sprocket attached to the rear axle.

Referring to Figures 3 and 4, the clutch control device as per the present invention comprises of a clutch cable 7 and clutch cable operating means. The clutch cable operating means consists of a cable quadrant system, a motor 1 and a control system 6. The cable quadrant system further consists of an upper casing 5, a lower casing 4, a quadrant 3 and a worm gear 2. The quadrant 3 has an integrated worm wheel 3 in addition to a cable lock such that the clutch cable 7 wrapped around the quadrant 3 is pulled when the worm wheel 3 rotates. The worm wheel 3 rotates due to rotary motion transmitted to it by a worm gear 2, which is in turn connected to the motor 1 at its other end. The motor operation is controlled by a control system 6 attached to its free end. The control system 6 is manually operated by the rider using a switch, which is either hand operated or is activated by a hand-lever mounted in the proximity of the handlebar. The control system 6 can also be programmed to work automatically based on throttle operation. With this configuration, utilising the existing clutch actuation within the engine, automation of the clutch cable actuation is achieved by imitating the cable pull actuation of the original clutch lever. The motor used for the above purpose could be a 12V DC motor and the clutch control device is placed in the vicinity of the head pipe 12 of the body frame 19. Additionally, a fail-safe mechanism, that is, the conventional clutch lever system can also be provided in case of any clutch control device malfunctions.

We Claim:

1. A clutch control device for an internal combustion engine including a clutch cable and a clutch control operating means, the said clutch cable operating means comprises a motor, a control system and a cable quadrant system.

2. The clutch control device as claimed in claim 1, wherein said cable quadrant system comprises an upper casing, a lower casing, a quadrant and a worm gear.

3. The clutch control device as claimed in claim 1, wherein said quadrant has an integrated worm wheel such that the clutch cable wrapped around the quadrant is pulled when the worm wheel rotates.

4. The clutch control device as claimed in claim 1, wherein rotary motion to the worm wheel is provided by the worm gear connected to the motor at its other end.

5. The clutch control device as claimed in claim 1, wherein the said motor is operated by a control system attached to its free end.

6. The clutch control device as claimed in claim 1, preferably located in the vicinity of the head pipe of a motorcycle.

7. A clutch control device for a motorcycle as hereinabove described in the specification with the accompanying drawings.