HYDRAULIC HAMMERING DEVICE

摘要

A hydraulic hammering device that uses a scheme in which a front chamber is switched into communication with a low-pressure circuit when a piston advances, wherein occurrences of “galling” to the piston at a sliding contact portion with a front-chamber liner is reduced. The front chamber has the front-chamber liner fitted to an inner surface of a cylinder. A hydraulic chamber space communicating with the front chamber and filled with hydraulic oil is formed as a cushion chamber on the inner peripheral surface of a rear portion of the front-chamber liner. The cushion chamber has a second drain circuit (from first end face grooves to slits to second end face grooves, which is provided separately from a drain circuit that guides the hydraulic fluid passing through a liner bearing of the front-chamber liner to the low-pressure circuit.

主权项

1. A hydraulic hammering device comprising:
a piston slidably fitted into a cylinder, the piston being configured to advance and retract to hammer a rod for hammering; a front chamber and a rear chamber that are defined between an outer peripheral surface of the piston and an inner peripheral surface of the cylinder and arranged separated from each other in the front and rear direction; and a switching valve mechanism configured to switch the front chamber into communication with a low pressure circuit when the piston advances and to supply and discharge hydraulic oil so that an advance and a retraction of the piston can be repeated, wherein the front chamber has a front-chamber liner that is fitted to an inner surface of the cylinder, a hydraulic chamber space is formed to the front-chamber liner as a cushion chamber, the hydraulic chamber space communicating with the front chamber to be filled with hydraulic oil, and the cushion chamber has a second drain circuit that is formed separately from a drain circuit configured to guide hydraulic oil passing a liner bearing section of the front-chamber liner to the low pressure circuit and that passes through portions other than the liner bearing section.