The present invention relates to a hammer raising device, and more particularly, to a hammer raising device capable of increasing striking intensity of a piston by eliminating fluid resistance within a main cylinder and the piston when the piston raised upward is lowered downward.
In general, a hammer refers to a device that is attached to equipment such as a loader or an excavator having a hydraulic pump, controls a high-pressure fluid supplied form the hydraulic pump by a predetermined flow path and a valve, raises and lowers a piston provided within the hydraulic hammer to strike a tool, and allows the tool to crush a rock bed or a concrete ground due to a reaction force.
Referring to
When a valve 100 is open, a high-pressure fluid supplied from a hydraulic pump is introduced into a cylinder 102. When the high-pressure fluid is introduced to an inside 99 of the cylinder 108, a piston 102 accommodated within a cylinder 108 is raised by a pressure of the introduced fluid.
As shown in
A gas stored in a charging-gas storage 106 formed at an upper part of the cylinder is slowly compressed by the raising of the piston 102. When the piston 102 is raised to a predetermined position by the fluid pressure, the valve 100 is closed, and the piston moves downward by a weight of the piston 102 and a force of the compressed gas in the charging-gas storage 106.
In this case, the fluid located between the cylinder and the piston moves to an accumulator 104. As described above, the hydraulic hammer according to the related art crushes a rock bed or a concrete bed by repeating the aforementioned operations.
Unfortunately, in the hydraulic hammer according to the related art, a sealing member is provided at a lower end so as not to allow the high-pressure fluid to leak into the gap between the piston and the cylinder, and, thus, an acceleration of the cylinder moving downward due to friction between the piston and the cylinder is decreased. Furthermore, a sealing member 88 which is located at the lower end as the sealing member for sealing the piston and the cylinder may be damaged due to the friction, and in order to maintain a desired sealing state, the damaged member needs to be periodically replaced with new one.
Moreover, when the piston moves downward, since the fluid existing in the inside 99 of the cylinder needs to be instantaneously discharged to the accumulator 104, striking intensity of the piston is remarkably reduced due to resistance generated in such a case.
An object of the present invention is to provide a method of increasing striking intensity of a piston by decreasing a frictional force between the piston and a cylinder to increase an acceleration of the piston moving downward.
Another object of the present invention is to provide a method capable of reducing management cost since a sealing member formed at a lower end to seal a gap between the piston and the cylinder is not used.
Still another object of the present invention is to provide a method of additionally preventing an overheating phenomenon between the cylinder and the piston without using a large-sized drain pipe for reducing resistance at a drain line.
To achieve this, an embodiment of the present invention provides a hammer raising device including: a hydraulic control valve that controls a supply of a fluid; a sub cylinder to which the fluid is supplied by an operation of the hydraulic control valve; a sub piston that is partially accommodated within the sub cylinder, and is raised or lowered by the fluid; a main piston that comes in close contact with a longitudinal end of the sub piston to be raised by the raising of the sub piston, and is lowered when the closely contacted longitudinal end of the sub piston is separated; and a main cylinder that accommodates the main piston.
In the hammer raising device according to the present invention, since a main piston provided within a main cylinder is raised using the piston and the cylinder provided outside without introducing a fluid into the main cylinder, a separate sealing member is not used between the main cylinder and the main piston. In this way, since the separate sealing member is not used, it is possible to prevent an acceleration from being decreased due to resistance caused by a frictional force between the main cylinder and the main piston. Further, since the main piston is raised using a plurality of sub pistons, it is possible to increase the number of times of striking of the piston.
In addition, in the hammer device according to the present invention, it is possible to freely adjust a movement range of the main piston for striking. That is, in the existing hammer device, it is necessary to introduce the fluid into the main cylinder, and it is necessary to increase the amount of the introduced fluid depending on the movement range of the main piston. However, in the hammer device according to the present invention, since the sub piston is used without introducing the fluid into the main cylinder, it is possible to freely adjust the movement range.
The aforementioned and additional aspects of the present invention will become more apparent through preferred embodiments described with reference to the accompanying drawings. Hereinafter, the embodiments of the present invention will be described in detail to allow those skilled in the art to easily understand and implement the present invention.
Referring to
A hydraulic control valve 200 controls movement of a high-pressure fluid supplied from a hydraulic pump. When the hydraulic control valve 200 is open, the fluid supplied from the hydraulic pump is supplied to a sub cylinder 202. The high-pressure fluid supplied to the sub cylinder 202 raises a sub piston 204 within the sub cylinder 202. The sub piston 204 comes in close contact with a lower end of a protruding portion of a main piston 206, and the main piston 206 is also raised by the raising of the sub piston 204.
The main piston 206 has a cylindrical shape, and has a shape whose central portion protrudes. A main cylinder 208 has a vent hole for accommodating the main piston 206 therein, and induces a vertical movement of the main piston 206.
Further, a diameter of the vent hole is not uniform such that the main piston 206 having the shape (protruding portion) whose central portion protrudes can vertically move within a predetermined range. That is, a region of the vent hole where the protruding portion of the main piston 206 vertically moves has a diameter larger than that of another region of the vent hole. A range of the vertical movement of the main piston 206 within the main cylinder 208 may be variously changed depending on an intention of a manufacturer. In the present invention, since the main piston is raised using the sub piston, a lower-end sealing member is not needed between the main piston and the main cylinder.
A gas stored in a charging-gas storage 210 formed at an upper part of the main cylinder 208 is compressed by the raising of the main piston 206. When the main piston 206 is raised to a predetermined position within the main cylinder 208, a switching valve (not shown) is operated. The sub piston 204 is separated from a lower end of the main piston 206 by the operation of the switching valve, and when the sub piston 204 is separated, the main piston 206 moves downward by a weight of the main piston 206 and a force of the compressed gas stored in the charging-gas storage 210. Naturally, when the switching valve is operated, the hydraulic control valve 200 is simultaneously closed. In this case, a frictional force is not generated between the main piston 206 and the main cylinder 208 as described above, and, thus, an acceleration of the main cylinder moving downward is more increased than that in the related art.
Furthermore, since the range of the vertical movement of the main piston within the main cylinder can be variously changed depending on the intention of the manufacturer as described above, it is possible to increase striking intensity due to the main piston by increasing the movement range when necessary. In contrast, the hydraulic hammer according to the related art has a demerit in that a size of the accumulator and the amount of the supplied fluid need to be increased in order to adjust the range of the vertical movement of the piston within the cylinder.
The sub piston 204 separated from the main piston 206 moves downward, and the sub piston moved downward raises the main piston.
It has been illustrated in
Referring to
A first hydraulic control valve 300 controls supplying of a high-pressure fluid supplied from a hydraulic pump to a first sub cylinder 302. A second hydraulic control valve 320 controls supplying of the high-pressure fluid supplied from the hydraulic pump to a second sub cylinder 312.
When the first hydraulic control valve 300 is open, the fluid supplied from the hydraulic pump is supplied to the first sub cylinder 302. When the second hydraulic control valve 320 is open, the fluid supplied from the hydraulic pump is supplied to the second sub cylinder 312. In the present invention, the first hydraulic control valve 300 and the second hydraulic control valve 310 are not simultaneously open but are alternately open.
The high-pressure fluid supplied to the first sub cylinder 302 raises a first sub piston 304 within the first sub cylinder 302. The first sub piston 304 comes in close contact with a lower end of a protruding portion of a main piston 306, and the main piston is also raised by the raising of the first sub piston 304.
A gas stored in a charging-gas storage 310 formed at an upper part of a main cylinder 308 is compressed by the raising of the main piston 306. When the main piston 306 is raised to a predetermined position, a first switching valve (not shown) is operated. The first sub piston 304 is separated from a lower end of the main piston 306 by the operation of the first switching valve, and when the first sub piston 304 is separated, the main piston 306 moves downward by a weight of the main piston 306 and a force of the compressed gas stored in the charging-gas storage 310. Naturally, when the first switching valve is operated, the first hydraulic control valve 300 is simultaneously closed.
The second sub cylinder 312, a second sub piston 314, and a second switching valve (not shown) perform the same operations as those of the first sub cylinder 302, the first sub piston 304, and the first switching valve. Naturally, as described above, a first drive unit including the first sub cylinder 302, the first sub piston 304 and the first switching valve and a second drive unit including the second sub cylinder 312, the second sub piston 314 and the second switching valve do not perform the same operation at the same point of time but alternately perform the operations at a regular period. In this way, by using the plurality of driving units, it is possible to increase the number of times of the vertical movement of the main piston. That is, before the main piston is lowered to reach a minimum point, at least one sub piston of the first sub piston and the second sub piston moves to reach the minimum point, so that it is possible to increase the number of times of the vertical movement of the main piston.
It is illustrated in
Referring to
Referring to
Referring to
Although the present invention has been described in conjunction with the embodiments illustrated in the drawings, the embodiments are merely examples. It should be understood to those skilled in the art that various modifications and other equivalent embodiments are possible.
Number | Date | Country | Kind |
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10-2012-0063876 | Jun 2012 | KR | national |
This is a US national phase of PCT patent Application No. PCT/KR2013/005180 having an International filing date of Jun. 12, 2013, which claims priority to Korean Patent Application No. 10-2012-0063876, filed on Jun. 14, 2012, the entireties of which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/KR2013/005180 | 6/12/2013 | WO | 00 |