In general, a hydraulic hitting device mounted to construction machines such as an excavator or a loader etc. serves to crush or punch a concrete or a rock. There are a hydraulic and a hydraulic rock drill and so on.
The hydraulic hitting device includes a hitting body and a bit rotation mechanism (hereinafter, “operating unit”) formed at the lower end thereof and having a bit rotated by a chisel or a rotary motor.
A piston is formed inside the hitting body of the hydraulic hitting device and serves to hit the end of the operating unit while being moved up and down by a hydraulic pressure.
FIG. 4 is a sectional view illustrating a state of mounting an operating unit 40 on a hitting body of a hydraulic rock drill according to the present invention. As shown, a bit rotation mechanism 2 having a bit 3 is formed at the lower end of the hitting body 1.
FIG. 6 illustrates a hydraulic breaker of the conventional hydraulic hitting device. As shown, the fixture 30 is formed at the lower end of the hitting body 1 and the operating unit 40 is fixed to the fixture 30.
The hitting body 1 includes a body 100 and an upper body 20. The piston 50 is formed at the inside of the body 10 and the upper body 20 is formed on the upper portion of the body 10.
A plurality of flow path grooves is formed at an inner wall of the body 10 and a plurality of flow path holes, which is in communication with the flow path grooves, is formed at the wall of the body 10.
The piston 50 of the hitting body 1 is moved up and down by means of the pressure difference between the upper and lower surfaces generated by the fluid flowing through the flow path grooves 11 and the flow path holes 12. At this time, the upper end of the operating unit 40 is repeatedly hit by the lower end of the piston 50.
The prior art on the hydraulic hitting devices are disclosed in Korean patent Nos. 1996-0006735, 0456786, 0998261, and 0772301 and Korean patent publication No. 2011-0086289.