| 摘要 |
<p>PURPOSE:To make a piston generate great kinematic energy and intend improvement of its working characteristic by making a high pressure act on the piston from the beginning of its return stroke so as to impact an object at the proximity of thecompletion of the going stroke. CONSTITUTION:A piston 15 is provided with both the first valve mechanisms 20, 21 and 18 which are communicated with a tank side pipe line 22 with the piston 15 in the proximity of its upper limit position, and the second valve mechanisms 16 and 12 which are communicated with a pump side pipe line 3 with the piston 15 in the proximity of the lower limit position. The second valve mechanism 16 is communicated with a pilot chamber 24 in a three-port two- position-switching valve 8 via a sequence valve 26. Since the piston 15 is subjected to a high pump liquid pressure from the beginning of its return stroke, and also to a considerably high pressure in the going stroke, great kinematic energy may be generated and stable operation can be assured.</p> |
