Control device of an impact mechanism operable by a pressure media having an element for reversing the axial pressurization of the percussion piston and the return of the medium. In order to achieve a controllability of impact mechanisms by which the energy and the frequency of the moved percussion piston can be adjusted, at least one channel switchable by the reversal as a return line for the medium from the percussion hammer has at least one switchable element for the flow control.

Control device of an impact mechanism operable by a pressure media having an element for reversing the axial pressurization of the percussion piston and the return of the medium. In order to achieve a controllability of impact mechanisms by which the energy and the frequency of the moved percussion piston can be adjusted, at least one channel switchable by the reversal as a return line for the medium from the percussion hammer has at least one switchable element for the flow control.

Hammering power of a hydraulic hammering device is improved by shortening a piston stroke, while keeping hammering energy. The device includes a cylinder, a piston slidingly fitted in the cylinder, and a piston front chamber and a piston rear chamber defined between an outer circumferential surface of the piston and an inner circumferential surface of the cylinder and disposed separately from each other at front and rear, respectively, in an axial direction. The device also includes a switching-valve mechanism driving the piston by switching at least one of the piston front or rear chamber into communication with at least one of a high pressure circuit or a low pressure circuit, and an acceleration piston disposed behind the piston and coming in contact with the piston during a retreat stroke of the piston to urge the piston forward in cooperation with braking force by pressurized oil acting on the piston.

Hammering power of a hydraulic hammering device is improved by shortening a piston stroke, while keeping hammering energy. The device includes a cylinder, a piston slidingly fitted in the cylinder, and a piston front chamber and a piston rear chamber defined between an outer circumferential surface of the piston and an inner circumferential surface of the cylinder and disposed separately from each other at front and rear, respectively, in an axial direction. The device also includes a switching-valve mechanism driving the piston by switching at least one of the piston front or rear chamber into communication with at least one of a high pressure circuit or a low pressure circuit, and an acceleration piston disposed behind the piston and coming in contact with the piston during a retreat stroke of the piston to urge the piston forward in cooperation with braking force by pressurized oil acting on the piston.

Provided is a stepless variable auto stroke hydraulic breaker system capable of reducing impact energy reflected in the event of an idle blow by detecting a frequency of vibrations generated when a chisel breaks objects such as bedrocks using a vibration sensor, operating according to a short stroke if the frequency of vibrations does not exceed a preset frequency, and automatically switching the short stroke into a long stroke if the frequency of vibrations exceeds the preset frequency. The breaker system includes a vibration sensor configured to detect vibrations generated when a chisel breaks rocks, a transmitter provided with the vibration sensor and configured to transmit signals generated from the vibration sensor, a receiver configured to receive the signals transmitted from the transmitter, and a stepless variable auto stroke hydraulic breaker controlled by a reception micro controller unit (MCU) of the receiver.

Provided is a stepless variable auto stroke hydraulic breaker system capable of reducing impact energy reflected in the event of an idle blow by detecting a frequency of vibrations generated when a chisel breaks objects such as bedrocks using a vibration sensor, operating according to a short stroke if the frequency of vibrations does not exceed a preset frequency, and automatically switching the short stroke into a long stroke if the frequency of vibrations exceeds the preset frequency. The breaker system includes a vibration sensor configured to detect vibrations generated when a chisel breaks rocks, a transmitter provided with the vibration sensor and configured to transmit signals generated from the vibration sensor, a receiver configured to receive the signals transmitted from the transmitter, and a stepless variable auto stroke hydraulic breaker controlled by a reception micro controller unit (MCU) of the receiver.

Provided a hammer raising device configured to increase striking intensity by eliminating fluid resistance when a piston raised upward moves downward. To achieve this, the hammer raising device includes 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.

Provided a hammer raising device configured to increase striking intensity by eliminating fluid resistance when a piston raised upward moves downward. To achieve this, the hammer raising device includes 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.

A switching method includes starting up a percussion device in acting on a control device arranged to vary the striking stroke of the striking piston between a short striking stroke and a long striking stroke. The percussion device is forced to operate on a short striking stroke for a predetermined period of time from the starting up of the device, and in acting on the control device so as to allow the percussion device to operate on a long striking stroke, after the expiry of the predetermined period of time.

A switching method includes starting up a percussion device in acting on a control device arranged to vary the striking stroke of the striking piston between a short striking stroke and a long striking stroke. The percussion device is forced to operate on a short striking stroke for a predetermined period of time from the starting up of the device, and in acting on the control device so as to allow the percussion device to operate on a long striking stroke, after the expiry of the predetermined period of time.