| 摘要 |
PURPOSE:To prevent a handle from becoming heavy even if a control circuit fails during the crawling-speed running by providing a safety circuit controlling the solenoid of a solenoid valve on the side where the assisting force of a power cylinder is applied when the car speed is a fixed value or lower. CONSTITUTION:When a car starts running, a control circuit 30 is operated, a microprocessor 31 reads a signal V in response to the car speed from a car speed sensor 37, the value of the control current (i) is searched from a characteristic map, and it is outputted to a transistor 35 via an interface 34. During the low-speed running, the control current (i) is a zero level, and the handle becomes light. During the high-speed running, the current (i) is a high level, and the handle becomes heavy. The signal of the car speed sensor is also inputted to a safety circuit 50, thus when the car is stopped, a transistor 51 is made nonconductive and the flow of the current (i) is stopped. Accordingly, during the car stop, the handle can be lightly operated even if the microprocessor 31 fails. |
