Patent Application
20080026913
Referring again in detail to the drawings and initially to
The front wheels 13 are steered by an operator of the car 11 by a suitable steering mechanism by means of a steering wheel 15. The rear wheels 14 are driven through a transmission 16 from a prime mover such as a fuel injected internal combustion engine, indicated generally by the reference numeral 17. However those skilled in the art will readily understand that the prime mover may also comprise an electric motor.
At least the rear wheels 14 are provided with brakes 18 of a suitable type operated by means of a brake pedal 19 positioned in proximity to the operator. The brake pedal 19 has a parking brake function to lock up in a braking condition by depressing a parking brake pedal 19 to stop the vehicle. When stopped, the vehicle is made immovable by locking the parking brake. Its release will be described shortly.
The engine 17 includes an ignition system 21 of any desired type for firing spark plugs (not shown) in accordance with any desired control routine. The engine 17 is supplied with fuel via one or more fuel injectors (not shown). The engine operation is under the control of an accelerator pedal 23 that is disposed adjacent the brake pedal 19. An accelerator position detector 24 detects depressing operation of the accelerator pedal 23 by the operator. In the illustrated embodiment, when the operator depresses the accelerator pedal 23 the detector 24 outputs a signal so that the engine 17 and car 11 is driven at a constant speed. Of course those skilled in the art will readily understand how the invention can be practiced with systems wherein the prime mover and car speed may be variable,
The accelerator position detector 24 and a key operated main switch 25 are connected to an engine controller, indicated generally at 26. The controller 26 is supplied with power from a battery 27. For charging the battery 27 and providing electrical power for operation of the car 11 there is provided a starter generator 28.
As has been noted, the brake pedal 19 has a parking brake function to lock up in a braking condition by depressing a parking brake pedal to stop the vehicle. The brake pedal 19 is provided with a brake release mechanism 29. While the vehicle is stationary with parking brakes applied, the brake pedal 19 is depressed again to initiate release of the parking brakes. The brake release mechanism is operated in according with the invention, as will be described shortly.
Referring now to
Rotation of the starter generator 28 cause the engine 17 to start. Attached for rotation to the engine crankshaft or any other shaft that rotates with the crankshaft is a rotor 32 having one or more timing marks that cooperates with a sensor 33 that sends pulser signals to the controller 26. The controller 26 calculates the rotational speed of the crankshaft and a crank angle based on these pulser signals. Upon determining the engine start-up, the controller 26 sends ignition signals to the engine ignition system 21. Further, determining a predetermined condition, for example in this embodiment that the engine speed reaches a certain preset value, the controller 26 sends a signal to initiate parking brake release by the break release mechanism 29.
The operation of this embodiment will now be described by reference to
When operating in accordance with the circuit as shown in
As described above, the engine speed required for releasing the parking brake is predetermined depending on, for example, the characteristics of the golf course. This prevents the parking brake from being released, if sufficient drive power has not yet been obtained after the accelerator pedal 23 was depressed. Thereby, the distance the vehicle move in reverse on the sloping road can thus be reduced or totally eliminated.
Referring now to
As shown by trace (A), the driver depresses the accelerator pedal and then the accelerator switch is ON at t0. With a small time lag after the accelerator switch is ON, the starter generator starts-up at t1 while the engine starts cranking, and then, ignition output begins at t2, as shown by traces (B) and (C), respectively. According to the second embodiment, at t2 when an ignition signal is first generated, the parking brake is released as shown by trace (D).
Thus, the vehicle starts moving at t2, and reverses slightly in the down slope direction, as shown by (E). However, after that, the engine ignition is started at t3, and the engine speed thus starts increasing. Therefore, at t4, the engine power reaches a level sufficient to enable the vehicle to move forward in the up slope direction.
In this embodiment, since the engine power at the time of releasing the parking brake is not sufficient to enable the vehicle to move forward in the upslope direction, the vehicle reverses slightly. However, the reverse distance is shorter compared to the conventional art (
In addition, as in the first embodiment, increasing the engine power for releasing the parking brake may cause the vehicle on the flat road to start suddenly. Therefore, as noted in the second embodiment, releasing the parking brake with low engine power allows the vehicle on the flat road to start smoothly. Thus, the second embodiment may be more suitable for gently undulating courses, for example.
It should be obvious to those skilled in the art that the present invention may apply to any vehicles driven by a fuel injection engine or a carbureted engine having a controller, or in fact even an electric motor. Of course those skilled in the art will readily understand that the described embodiments are only of a exemplary forms that the invention may take and that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.
