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US 2020/0181978 A1Published application
Two-Piston Hydraulic Striking Device
AssigneeFurukawa Rock Drill Co., Ltd.
InventorsMasahiro Koizumi, Toshio Matsuda
Life of this patent
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Abstract
Provided is a two-piston hydraulic striking device that has stable operatively. This two-piston hydraulic striking device includes two striking mechanisms for striking one transfer member. Each striking mechanism has a pressure receiving area ratio between the front and rear of a piston thereof set in such a way that the two striking mechanisms have the same cycle time.
Claims14
A two-piston hydraulic striking device comprising:
- a striking mechanism configured to strike one transfer member with two pistons, wherein
- the striking mechanism includes a first striking mechanism and a second striking mechanism, and the first striking mechanism and the second striking mechanism are arranged in series in front and rear direction in such a way that striking axes are coaxial with each other and the second striking mechanism is positioned on a side where the one transfer member is located,
- the first striking mechanism includes:
- a first cylinder;
- a first piston configured to be slidably fitted into the first cylinder in such a manner as to be able to advance and retract, the first piston having a first striking portion for striking the one transfer member at a tip portion of the first piston;
- and a first switching valve configured to switch advancing and retracting movements of the first piston,
- the second striking mechanism includes:
- a second cylinder;
- a second piston configured to be slidably fitted into the second cylinder in such a manner as to be able to advance and retract, the second piston having a second striking portion for striking the one transfer member at a tip portion of the second piston;
- and
- a second switching valve configured to switch advancing and retracting movements of the second piston,
- only either the first striking mechanism or the second striking mechanism includes a valve controller for controlling operation of both the first switching valve and the second switching valve,
- of the two pistons, at least the second piston is formed into a hollow shape and the first piston is inserted into inside of the second piston in such a way that the first striking portion extends in such a manner as to be able to strike the one transfer member, and
- each of the two pistons has a pressure receiving area ratio between front and rear of the piston set to satisfy a formula below:
- [t1a+t1c]=t1b=[t2a+t2c]=t2b (Formula),
- where t1a, t1b, t1c, t2a, t2b, and t2c represent an advance time of the first piston, a retraction acceleration time of the first piston, a retraction deceleration time of the first piston, an advance time of the second piston, a retraction acceleration time of the second piston, and a retraction deceleration time of the second piston, respectively.
13 more elements
A two-piston hydraulic striking device comprising:
- a striking mechanism configured to strike one or a plurality of transfer members with two pistons, wherein
- the striking mechanism includes a first striking mechanism and a second striking mechanism, and the first striking mechanism and the second striking mechanism are arranged in such a way that striking axes are in parallel with each other,
- the first striking mechanism includes:
- a first cylinder;
- a first piston configured to be slidably fitted into the first cylinder in such a manner as to be able to advance and retract, the first piston having a first striking portion for striking the one or the plurality of transfer members at a tip portion of the first piston;
- and a first switching valve configured to switch advancing and retracting movements of the first piston,
- the second striking mechanism includes:
- a second cylinder;
- a second piston configured to be slidably fitted into the second cylinder in such a manner as to be able to advance and retract, the second piston having a second striking portion for striking the one or the plurality of transfer members at a tip portion of the second piston;
- and a second switching valve configured to switch advancing and retracting movements of the second piston,
- only the first striking mechanism includes a valve controller for controlling operation of both the first switching valve and the second switching valve, and
- each of the two pistons has a pressure receiving area ratio between front and rear of the piston set to satisfy a formula below:
- [t1a+t1c]=t1b=[t2a+t2c]=t2b (Formula),
- where t1a, t1b, t1c, t2a, t2b, and t2c represent an advance time of the first piston, a retraction acceleration time of the first piston, a retraction deceleration time of the first piston, an advance time of the second piston, a retraction acceleration time of the second piston, and a retraction deceleration time of the second piston, respectively.
11 more elements
Dependencies are inferred from the claim text.