| 摘要 |
<p>PURPOSE:To ensure braking operation upon quick pressure application, by allowing fluid to flow in only one direction from a large diameter side fluid chamber to a small diameter side fluid chamber in a large and small diameter cylinders, respectively, and by relieving fluid pressure in the large diameter side fluid chamber to a reservoir when fluid pressure in the small diameter side fluid chamber is above a predetermined pressure. CONSTITUTION:A check valve is constituted with a ball 13 and a valve seat 14 in the opening of a through passage 4a in a small diameter piston 4, and allows fluid to flow in only one direction from a fluid chamber B in a large diameter cylinder 3 to a fluid chamber A in a small diameter cylinder 2 but restricts fluid counterflow from the chamber A to the chamber B. Further, an output passage 18 is connected to the chamber A, and cylinders 19, 20, 21 are formed in communication with the passage 18. A relief piston 25 is slidably fitted in these cylinders, and a relief valve is constituted with a ball 27, a relief spring 28 and a valve seat 26 formed in the cylinders 20, 21. The piston 25 opens the relief valve when the fluid pressure in the chamber A increases above a predetermined value, thereby pressure in the chamber B is relieved to a reservoir 22.</p> |
