Device and a method for moving a jet member

A device for moving a jet member (8), which is arranged on a carriage (6) arranged on a vehicle for directing a high pressure jet of liquid against a material layer for material removing treatment of the material layer, said carriage being movable to and fro along a guide (5) between two selectable extreme positions along the guide, said device comprising a hydraulic drive arrangement (26) having a hydraulic circuit (27) and being arranged to create the movement of the carriage along the guide, means (12, 21′, 13, 24, 25, 31) adapted to detect that the carriage has reached a selectable extreme position along the guide, where turning of the carriage is to take place, as well as a control unit (14) adapted to control the hydraulic drive arrangement and by that said movement of the carriage along the guide, wherein

• said means comprises a member (24, 25, 34) designed to form a mechanical resistance to a further movement of the carriage when the carriage reaches the respective said extreme position or a region close to said extreme position adapted to influence the flow of hydraulic liquid through said hydraulic circuit of the hydraulic drive arrangement and a member (31) adapted to sense a parameter of the hydraulic liquid, the magnitude of which is dependent upon said flow, and send information about the magnitude of this parameter to the control unit (14), and the control unit is adapted to control the turning of the carriage on the basis of information about the magnitude of said parameter,
• said sensing member (31) is adapted to sense the pressure of the hydraulic liquid in said hydraulic circuit (27) between a hydraulic pump (28) and a hydraulic motor (29) arranged at the carriage, and
• the hydraulic circuit comprises a restriction (30), and the sensing member (31) is adapted to measure the pressure of the hydraulic liquid downstream of said restriction.

A device for moving a jet member (8), which is arranged on a carriage (6) arranged on a vehicle for directing a high pressure jet of liquid against a material layer for material removing treatment of the material layer, said carriage being movable to and fro along a guide (5) between two selectable extreme positions along the guide said device comprising a hydraulic drive arrangement (26) having a hydraulic circuit (27) and being arranged to create the movement of the carriage along the guide, means (12, 21′, 13, 24, 25, 31) adapted to detect that the carriage has reached a selectable extreme position along the guide, where turning of the carriage is to take place, as well as a control unit (14) adapted to control the hydraulic drive arrangement and by that said movement of the carriage along the guide, wherein

• said means comprises a member (24, 25, 34) designed to form a mechanical resistance to a further movement of the carriage when the carriage reaches the respective said extreme position or a region close to said extreme position adapted to influence the flow of hydraulic liquid through said hydraulic circuit of the hydraulic drive arrangement, and a member (31) adapted to sense a parameter of the hydraulic liquid, the magnitude of which is dependent upon said flow, and send information about the magnitude of this parameter to the control unit 14 and the control unit is adapted to control the turning the carriage on the basis of information about the magnitude of said parameter,
• the mechanical resistance member is formed by a mechanical stop member (24, 25) arranged along the guide (5) and to define said extreme position by forming an obstacle to and being hit by the carriage (6) or a member connected thereto,
• the hydraulic circuit comprises a restriction (30), the sensing member (31) is adapted to measure the pressure of the hydraulic liquid downstream of said restriction, and the sensing member (31) is adapted to measure said hydraulic pressure each time the carriage (6) has turned when starting the movement towards the opposite extreme position, and
• the control unit (14) is adapted to store the pressure value so measured and determine that an extreme position has been reached when it receives information about an existing pressure exceeding this initial pressure value by a predetermined magnitude from said sensing member.

A device for moving a jet member (8), which is arranged on a carriage (6) arranged on a vehicle for directing a high pressure jet of liquid against a material layer for material removing treatment of the material layer, said carriage being movable to and fro along a guide (5) between two selectable extreme positions along the guide, said device comprising a hydraulic drive arrangement (26) having a hydraulic circuit (27) and being arranged to create the movement of the carriage along the guide, means (12, 21′, 13, 24, 25, 31) adapted to detect that the carriage has reached a selectable extreme position along the guide, where turning of the carriage is to take place, as well as a control unit (14) adapted to control the hydraulic drive arrangement and by that said movement of the carriage along the guide, wherein

• said means comprises a member (24, 25, 34) designed to form a mechanical resistance to a further movement of the carriage when the carriage reaches the respective said extreme position or a region close to said extreme position adapted to influence the flow of hydraulic liquid through said hydraulic circuit of the hydraulic drive arrangement, and a member (31) adapted to sense a parameter of the hydraulic liquid, the magnitude of which is dependent upon said flow, and send information about the magnitude of this parameter to the control unit (14), and the control unit is adapted to control the turning of the carriage on the basis of information about the magnitude of said parameter, and
• said sensing member is adapted to measure speed of the flow of hydraulic liquid in the hydraulic circuit (27).

A device for moving a jet member (8), which is arranged on a carriage (6) arranged on a vehicle for directing a high pressure jet of liquid against a material layer for material removing treatment of the material layer said carriage being movable to and fro along a guide (5) between two selectable extreme positions along the guide said device comprising a hydraulic drive arrangement (26) having a hydraulic circuit (27) and being arranged to create the movement of the carriage along the guide, means (12, 21′, 13, 24, 25, 31) adapted to detect that the carriage has reached a selectable extreme position along the guide, where turning of the carriage is to take place, as well as a control unit (14) adapted to control the hydraulic drive arrangement and by that said movement of the carriage along the guide, wherein

• said means comprises a member (24, 25, 34) designed to form a mechanical resistance to a further movement of the carriage when the carriage reaches the respective said extreme position or a region close to said extreme position adapted to influence the flow of hydraulic liquid through said hydraulic circuit of the hydraulic drive arrangement, and a member (31) adapted to sense a parameter of the hydraulic liquid, the magnitude of which is dependent upon said flow, and send information about the magnitude of this parameter to the control unit (14), and the control unit is adapted to control the turning of the carriage on the basis of information about the magnitude of said parameter, and
• it further comprises a second sensing member (13) arranged on said carriage (6) and marks (12, 12′) arranged along said guide, the second sensing member is designed to detect that the carriage reaches said marks and send information thereabout to the control unit (14), and the control unit is adapted to enable changing between by, on one hand, letting said detecting means determine the position of said extreme positions and, on the other hand, letting said marks determine the position of said extreme positions.

A method for moving a jet member, which is arranged on a carriage (6) arranged on a vehicle for directing a high pressure jet of liquid against a material layer for material removing treatment of the material layer, in which the carriage is movable to and fro along a guide (5) between two selectable extreme positions along the guide and brought to move alone the guide through influence from a hydraulic drive arrangement (26) having a hydraulic circuit, and it is detected that the carriage has reached an extreme position along the guide where turning of the carriage is to take place, wherein

• responsive to the carriage reaching the respective said extreme position or a region close to said extreme position, a mechanical resistance is formed against continued movement of the carriage, said resistance being adapted to influence the flow of hydraulic fluid through said hydraulic circuit of the hydraulic drive arrangement, a parameter of the hydraulic liquid, the magnitude of which is depending upon said flow, is sensed, and the turning of the carriage is controlled on the basis of information about the magnitude of said parameter, and
• the magnitude of a change of said magnitude of said parameter is compared with a predetermined value and it is determined that an extreme position has been reached responsive to the magnitude of said change exceeding the predetermined value and a turning of the carriage (6) is by that initiated.

A method for moving a jet member, which is arranged on a carriage (6) arranged on a vehicle for directing a high pressure jet of liquid against a material layer for material removing treatment of the material layer, in which the carriage is movable to and fro along a guide (5) between two selectable extreme positions along the guide and brought to move along the guide through influence from a hydraulic drive arrangement (26) having a hydraulic circuit, and it is detected that the carriage has reached an extreme position along the guide where turning of the carriage is to take place, wherein

• when the carriage reaches the respective said extreme position or a region close to said extreme position, a mechanical resistance is formed against continued movement of the carriage, said resistance being adapted to influence the flow of hydraulic fluid through said hydraulic circuit of the hydraulic drive arrangement, a parameter of the hydraulic liquid, the magnitude of which is depending upon said flow, is sensed, and the turning of the carriage is controlled on the basis of information about the magnitude of said parameter,
• the pressure of the hydraulic liquid in said hydraulic circuit (27) between a hydraulic pump (28) and a hydraulic motor (29) arranged at the carriage (6) is sensed as said parameter, and
• the pressure of the hydraulic liquid in the hydraulic circuit is measured downstream of a restriction (30) arranged in the hydraulic circuit between the hydraulic pump (28) and the hydraulic motor (29).