Title:
AUTOMATIC SHIFT SWITCHING VALVE FOR TWO-SPEED HYDRAULIC MOTOR
Document Type and Number:
Japanese Patent JP2015017684
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide an automatic shift switching valve for switching a two-speed hydraulic motor between a high-speed state and a low-speed state.SOLUTION: An automatic shift switching valve 7 includes a hollow two-speed spool 10, a first small-diameter spool C and a second small-diameter spool B fitted to both ends of the two-speed spool 10 movably in the axial direction, and a spring 8 provided between a hollow hole shoulder part 19 of the two-speed spool 10 and the second small-diameter spool B. An external pilot pressure Pis guided to the first small-diameter spool C and a two-speed spool outer end, and a high port pressure Pab of a hydraulic motor 1 to counteract the external pilot pressure Pis guided from a center port A.B into a hollow hole 20 so as to consistently operate on the inside faces of the first small-diameter spool C and the second small-diameter spool B in the second-speed spool 10. Drain ports DR are provided between an A' port and a Pport and between the A.B port and the Pport, respectively.
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| JPH0579141 | [Name of device] Switching valve |
Inventors:
EJIRI MAKOTO
Application Number:
JP2013146237A
Publication Date:
January 29, 2015
Filing Date:
July 12, 2013
Export Citation:
Assignee:
NACHI FUJIKOSHI CORP
International Classes:
F16K11/07; F04C14/02
Domestic Patent References:
| JP4160862B2 | 2008-10-08 | |||
| JPH08326936A | 1996-12-10 | |||
| JP2008069916A | 2008-03-27 |
Attorney, Agent or Firm:
Akiko Okajima