Title:
FLUID-PRESSURE TYPE STRIKING DEVICE
Document Type and Number:
Japanese Patent JP2021016931
Kind Code:
A
Abstract:
To provide a fluid-pressure type striking device that is capable of selecting an idle-hitting preventive mechanism and that improves workability, improves stability, and facilitates restarting.SOLUTION: A fluid-pressure type striking device is constituted of a first low pressure port 107 opening at a position which connects a first control valve communication port 106 and a low pressure circuit 111 via an annular ring groove 125 arranged in a center in an axial direction of large diameter parts 121, 122 of a piston 120 when the low pressure port 109 switches the piston 120 to a retreat process from an advance process, and a second low pressure port 108 opening at a position which is axially rearward of the first low pressure port 107 and which is cut off from a piston rear chamber 102 by the large diameter parts 121, 122 of the piston 120 in a state where the piston 120 has advanced to the front dead point.SELECTED DRAWING: Figure 1
Inventors:
NAGANO SHINSUKE
KOSHIBA HIDETOSHI
KOSHIBA HIDETOSHI
Application Number:
JP2019135559A
Publication Date:
February 15, 2021
Filing Date:
July 23, 2019
Export Citation:
Assignee:
FURUKAWA ROCK DRILL CO LTD
International Classes:
B25D9/26; B25D17/10
Domestic Patent References:
| JPH1080878A | 1998-03-31 | |||
| JP2003025251A | 2003-01-29 | |||
| JP2017226065A | 2017-12-28 | |||
| JPH0549280U | 1993-06-29 |
Foreign References:
| WO2019022021A1 | 2019-01-31 | |||
| WO2018043175A1 | 2018-03-08 | |||
| US20140326473A1 | 2014-11-06 |
Attorney, Agent or Firm:
Hide Tanaka Tetsu
Ichi Hirose
Tetsuya Mori
Ichi Hirose
Tetsuya Mori