| 摘要 |
<p>PURPOSE:To save an independent hydraulic pressure controller by accommodating a first hydraulic pressure control mechanism for reducing the supply of hydraulic pressure to a second liquid chamber with a constant rate when the pressure of a first liquid chamber reaches to a first given pressure and a first spring for energizing it to open. CONSTITUTION:When the hydraulic pressure of a fluid source is pressed, while the internal pressure of a first liquid chamber A and a second liquid chamber B is equally raised by opening the valve of a first hydraulic pressure control mechanism V1, a main piston 8 is pressed to start the operation of a service brake. When the hydraulic pressure of the fluid source is subsequently pressed, the hydraulic pressure is increased to make an operating force to a right outer peripheral direction of a plunger 16 higher than the spring force of a first spring 20. Then, a valve head 16a is seated on a valve seat 18 to temporarily close a flow passage to the second liquid chamber B, but from the relation of a pressure receiving effective diameter D larger than d, the first hydraulic pressure control mechanism V1 is intermittently operated.</p> |
