Abstract:
The lubrication system (150) includes a drive fluid valve member (156; 224) and a detune valve member (166; 260). The drive fluid valve member (156; 224) is movable from a first to a second position in response to drive fluid pressure to reduce the volume of a variable volume lubricant charge chamber (230). The detune valve member (166; 260) is movable from a first to a second position in response to lubricant pressure within the lubricant charge chamber (230), and is adapted to permit fluid communication between inlet and fluid bypass passages (146, 164) in its first position and to disengage the fluid connection in its second position.
Abstract:
A device in a hydraulic rock drilling machine (1) including a distribution valve (7,7', 7") arranged in connection with the rock drilling machine for controlling hydraulic flows to different parts of the rock drilling machine, wherein the distribution valve includes a valve body (8, 8', 8"), which is arranged movable to and fro in axial directions inside a valve chamber (33) and wherein the valve chamber is limited in axial direction by two valve end walls (10,11; 10 ',11'; 10",11"). One of the valve end walls is movable in an axial direction against an abutment (12,12") in such a way that it defines an end position for the valve body, and a pressing device (13,13 ',13") is arranged for pressing said at least one of the valve end walls against said abutment. The invention also relates to a rock drilling machine.
Abstract:
A sleeve (20) carried by and preferably slidable relative to the piston ( 14), for controlling air passages (32, 38) associated with a central air feed tube (22), whereby retraction pressure is applied to the piston ( 14) substantially at impact It is the impact itself of the piston ( 14) against the bit ( 16), which enhances sliding of the sleeve (20) relative to the piston ( 14), over the feed tube (22), and thereby switches the airflow at the moment of impact
Abstract:
L'invention concerne un dispositif de dessablage des noyaux de fonderie, comprenant : un fût (1) comportant des premiers moyens (20) d'arrivée d'air comprimé et des moyens (25) d'évacuation d'air puisé ; un cylindre d'approche (3) coulissant dans le fût sous l'action de l'air comprimé, entre une position rétractée et une position de travail où une bouterolle (5) est en contact avec une pièce de travail ; et des moyens de frappe (50) pour imprimer des chocs répétés sur la bouterolle. Ce dispositif comprend des moyens de soufflage (29) pour créer un rideau d'air autour du cylindre d'approche au niveau de l'emplacement où il pénètre dans le corps.
Abstract:
A valve device (V, 4') for controlling the movement in a machine housing (2) of a reciprocating percussion piston (3) of a percussion device (1) for a rock drilling machine with a first chamber (5) that can be pressurized for forward driving of the percussion piston (3) and a second chamber (8) that can be pressurized for back-driving of the percussion piston (3) , wherein the valve device includes a to and fro movable valve element (20) , the movement of which being controlled as a response to the position of a valve portion (V) of the percussion piston in a valve housing portion by periodically pressurising a signal chamber (21) actuating the movement of the valve element over signal conduit means (22, 23, 24) . Said signal conduit means includes at least two signal conduit portions (23, 24) , which are arranged for essentially simultaneous pressurising through co-operation between a corresponding number of valve control edges (25, 26) on the valve portion of the percussion piston and edges (34, 35) of control chambers in the machine housing. The invention also concerns a percussion device and a rock drilling machine.
Abstract:
A percussion device (1) with a reciprocating percussion piston (3) , includes a first chamber (5) that can be pressurized for forward driving of the percussion piston (3) and a second chamber (8) that can be periodically pressurized for back- driving of the percussion piston (3) . The percussion device includes at least one driving piston (7) arranged for actuating the back-driving of the percussion piston (3) wherein a portion of said driving piston (7) is arranged to enter into the second chamber (8) for pressure actuating on a driving surface of the driving piston by pressure medium being present in this chamber in the direction of back-driving, wherein the driving piston (7) includes means for back-driving co- operation with the percussion piston (3) , and wherein the driving piston (7) is free for axial movement with respect to the percussion piston (3), opposite the direction of back- driving. The invention also concerns a method and a rock drilling machine .
Abstract:
A single-stroke percussion device comprises a hollow cylindrical casing (1) and, mounted inside it, a reciprocally-movable striker (2) dividing the cavity of the casing (1) into an upper and a lower chamber (3, 4). A spring-loaded valve (5) is mounted on the side of the lower chamber and carries a working organ (6) fixed to it. An air distributor (7) provided with channels (8, 9, 10) and with a control grip (11) is mounted on the side of the upper chamber (3). The striker (2) has an axial channel (13) in which is mounted a tube (14) provided with a flange (15) on its external surface and with a blind internal partition (16). The tube (14) has an upper and a lower window (17, 18) located on both sides of the partition (16). An air distributing sleeve (19) provided with an internal groove (21) and spring-loaded on the side of the air distributor (7) is mounted on the tube (14). The air distributing sleeve (19) is capable of being moved, under the action of the striker (2), to its upper position where it closes the lower windows (18), and, under the action of the spring (20), to its lower position, limited by the flange (15), where it connects, through the internal groove (21), the upper and lower windows (17, 18).
Abstract:
A rock drilling machine (2) which is adapted to intermittently produce shock wave pulses for transfer over a drill string (3) to a rock disintegrating drill bit (6). The rock drilling machine includes: a force setting unit (8) which is arranged to periodically subject the drill string (3) to a setting force in said drilling direction, and a control unit (11) which is arranged to activate the force setting unit to initiate said setting force before a point of time for producing at least a selection of said shock wave pulses in order to ensure enhanced rock contact of the drill bit (6) when performing an impact. The invention also concerns a method and a rock drill rig.
Abstract:
An impact system (70) for a hydraulic hammer (20) is disclosed. The impact system includes a piston (80), a sleeve (100) disposed co¬ axial with the piston, and an accumulator membrane (90) disposed external to the sleeve. A first seal (137) is located at an end of the sleeve, and configured to connect the sleeve to the piston. The accumulator membrane has an extension (97) configured to engage a recess (109) in the sleeve.