| 摘要 |
PURPOSE:To prevent a piston and a cylinder from damages by providing a pressure accumulator between a pressure chamber and a switch valve of a master cylinder on one side for constructing to receive and accumulate discharge liquids of the switch valve and the pressure chamber during the operation of the switch valve. CONSTITUTION:When a student brake 10 is released after operation and an instructor brake 12 is stepped on, the second brake master cylinder 30 is operated, and liquid pressure is supplied to switch valves 50 and 150 to operate switch wheel brake cylinders 37 and 40. While this switch valve 150 is operated form switching, the liqui of a fixed quantity Q1 is supplied to a pressure chamber 23 of the first master cylinder 20 via a pipe 38 to tend to increase pressure. Meanwhile, a piston 175 of a pressure-reacting valve 170 is moved to the right by the liquid pressure in a pipe 44, and a liquid 38 from the switch valve 150 is introduced into a pressure accumulator 160 via the pressure-reacting valve 170 and a pipe 45 for restraining the rise of the pressure in the second pressure chamber 23. This construction permits to prevent damages of a secondary piston 22. |
