Simplification of the Shift/Clutch Operations for the ...

1 20076616(JSAE) 2007-32-0116(SAE) SETC 2007 1/8 Simplification of the Shift/Clutch Operations for the formula SAE Vehicles (1) (1) (1) (2) Hiroshi ENOMOTO, Hironari MORITA, Yousuke FUKUNAGA and Naoki UOTA (1) (2) Kanazawa university and KADO corporation Copyright 2007 Society of Automotive Engineers of Japan, Inc.

2 And Copyright 2007 SAE International The simplified Shift/Clutch operation system, KF-TOS-P, was driven by DC motors (DC12V driven) with a microprocessor. Two rotary sensors detected the positions of the shift lever and the clutch lever. In FSAE rules, the simple throttle-by-wire is prohibited and the engine speed was controlled by the drivers. The custom steering wheel, KF-SW07 as the human machine interface, was designed and manufactured with CFRP by VaRTM (Vacuum assisted Resin Transfer Modeling) method. The shift operation time of KF-TOS-P was half of the manual operation and the clutch engagement time of that was 25msec.

3 KF-SW07 was weight and cost (calculated by FSAE rules) of the commercial steering wheel of the race use. Keywords Electric equipment, Steering Wheel, Shift/Clutch Operations , Carbon Fiber Reinforced Plastic 1. INTRODUCTION Many FSAE cars use super-sport bike engines that have built-in manual transmissions. The drivers release the hand from the steering wheel when they control these transmissions. In FSAE rules, the students should be drivers and it is difficult to find well-trained students or to train them in circuits in Japan.

4 Such amateur drivers cannot control well these hand-release transmission. As the FSAE car is a racing car, these transmission operating systems should satisfy many trade-off parameters, light weight, easy-maintenance, easy-processing, tough-enough, low cost and so on. The related FSAE rules [1] are Transmission and Drive , Throttle Actuation . The Transmission and Drive rule say that we can use any transmission and any drive train. The Throttle Actuation rule say that we must use only mechanical throttle actuation system such as a cable and a rod system.

5 The steering wheel is used as the human machine interface for the transmission control. The interface of the Front roll hoopSteeringwheelFront roll hoopno lower than topof the steering distance must beno more than 250mm. Figure 1 Schematic of the steering wheel and the shift/crutch handle for KF2006. Figure 2 The commercial steering wheel for KF2003 KF2006. Weight: 473g 20076616(JSAE) 2007-32-0116(SAE) SETC 2007 2/8 transmission control has two buttons for the up shift and for the down shift.

6 The drivers could grasp the steering wheel with both hands during the races with the interfaces. The steering wheel shape and the location are defined in FSAE rules as Circular Shape Required , Front Hoop . The Circular Shape Required rule say that we must use steering wheel that have a continuous perimeter that is near circular or near oval. The steering wheels that have H , Figure 9 , or cutout shape are not allowed. The Front Hoop rule determines the position relations of the steering wheel and front roll hoop.

7 Figure 1 shows the schematic of these rules. The commercial steering wheel in Fig. 2 was used until 2006. The weight was 470g. It was difficult to process it to mount switches on. In this paper, the transmission control to simplify the operation was described. The system included the custom steering wheel, KF-SW07. 2. METHOD 2. 1 Transmission operating A light-weight, small-size and high-quality transmission should be mounted on the FSAE racing car and many teams use the super-sports bike built-in transmissions.

8 However, the drivers should control these transmissions manually shown in Table 1(a). For such amateur drivers or the weekend racers defined in FSAE rules, the quick and accurate Operations are not easy because large acceleration occurs in accelerating, decelerating and cornering. From these facts, Kanazawa University formula R&D used CVT (Continuously Variable Transmission) transmission to eliminate the hardness for KF2003, the first FSAE car that participated in the first FSAE Japan competition held in 2003.

9 Our Kanazawa formula racing team has given the model code as KFxxxx to the successively developed racing vehicles. The four digit number xxxx signifies the year in which the team joined the race with those vehicles. For example, for the first participated year of 2003, the racing car is named as KF2003 and in the successive years the cars are named in the same manner. The CVT, built in the inline 2 cylinders 600cc engine which is commercially used for the scooter, was a little heavy and large and used dry belt.

10 The dry belt could not transmit the high torque immediately and the disadvantages were not small in FSAE circuit events because the circuit had many tight corners and short straights. After deepest reflection, KF2004, developed in 2004, had the inline 4 cylinders 600cc engine for the competitive motorcycle use. The built-in transmission needed a manual operation that was usual in FSAE competitions. As the foot pedal controlled the clutch , KF2004 had three pedals and the left-hand lever to operate the shift.