The present invention relates, in particular, to a forging hammer comprising a striker and a hydraulic linear drive that is coupled to the striker and is designed to drive the striker, which drive comprises a hydraulic circuit having a servo-motor hydro pump, a hydraulic cylinder, in particular a differential cylinder, which is fluidically connected downstream of the hydro pump via a directional valve module, and a servo-motor hydro generator, which is fluidically connected downstream of the hydraulic cylinder via the directional valve module, and comprising in addition a control unit configured at least for the simultaneous control of the hydro pump, the hydro generator and the directional valve module.

The present invention relates, in particular, to a forging hammer comprising a striker and a hydraulic linear drive that is coupled to the striker and is designed to drive the striker, which drive comprises a hydraulic circuit having a servo-motor hydro pump, a hydraulic cylinder, in particular a differential cylinder, which is fluidically connected downstream of the hydro pump via a directional valve module, and a servo-motor hydro generator, which is fluidically connected downstream of the hydraulic cylinder via the directional valve module, and comprising in addition a control unit configured at least for the simultaneous control of the hydro pump, the hydro generator and the directional valve module.

A hydraulic forging machine and a method for replacing an upper anvil block thereof are disclosed. The hydraulic forging machine includes locking hydraulic cylinder that is fixed to a movable beam of the hydraulic forging machine when the hydraulic forging machine is in operation. The locking hydraulic cylinder is configured to provide a locking-unlocking function between an upper anvil block of the hydraulic forging machine and the movable beam. The locking hydraulic cylinder has its hydraulic power source supplied from a main hydraulic cylinder or a return hydraulic cylinder, which is also fixed to the movable beam. The present disclosure not only enables an oil supply circuit for the locking hydraulic cylinder to move together with the movable beam, but also simplifies the oil supply circuit for the locking hydraulic cylinder, resulting in an improved reliability of the hydraulic forging machine.

A hydraulic forging machine and a method for replacing an upper anvil block thereof are disclosed. The hydraulic forging machine includes locking hydraulic cylinder that is fixed to a movable beam of the hydraulic forging machine when the hydraulic forging machine is in operation. The locking hydraulic cylinder is configured to provide a locking-unlocking function between an upper anvil block of the hydraulic forging machine and the movable beam. The locking hydraulic cylinder has its hydraulic power source supplied from a main hydraulic cylinder or a return hydraulic cylinder, which is also fixed to the movable beam. The present disclosure not only enables an oil supply circuit for the locking hydraulic cylinder to move together with the movable beam, but also simplifies the oil supply circuit for the locking hydraulic cylinder, resulting in an improved reliability of the hydraulic forging machine.

A motor control device includes a pressure command unit calculating a pressure command for commanding pressure generated in a pressure control object, a pressure detection unit detecting the pressure generated in the pressure control object, a pressure control unit calculating a speed command for pressure control for the servo motor, based on the calculated pressure command and the detected pressure, and a servo control unit controlling speed of the servo motor, based on the calculated speed command. The pressure control unit performs an integral operation. When a direction of increasing pressure in the integral operation is defined as a positive direction in the integral operation, and a direction of decreasing the pressure is defined as a negative direction, a median between an upper limit in the positive direction and a lower limit in the negative direction in the integral operation is larger than zero.

A forging device for molten metal includes first and second die bodies that are linked by first and second power arms to move back and forth in a cavity of a die base so as to open and close a workpiece shaping space defined between first and second die faces of the first and second die bodies. When the workpiece shaping space is opened, a molten metal is poured, and then the workpiece shaping space is closed to cast a semi-finished workpiece. After that, the first and second power arms axially press and forge the semi-finished workpiece in the workpiece shaping space into a high-strength workpiece. The high-strength workpiece is shaped by casting and forging in the same process.

A forging device for molten metal includes first and second die bodies that are linked by first and second power arms to move back and forth in a cavity of a die base so as to open and close a workpiece shaping space defined between first and second die faces of the first and second die bodies. When the workpiece shaping space is opened, a molten metal is poured, and then the workpiece shaping space is closed to cast a semi-finished workpiece. After that, the first and second power arms axially press and forge the semi-finished workpiece in the workpiece shaping space into a high-strength workpiece. The high-strength workpiece is shaped by casting and forging in the same process.

A two-step auto stroke hydraulic breaker includes a cylinder including a high-low pressure chamber, a high pressure chamber, and a pressure converting chamber including a pilot port, a high pressure connecting port connected to the high pressure chamber, a sensing port, an oil tank port, a long stroke port, and a short stroke port, a piston including small diameter portions, upper and lower large diameter portions, a sensing fluid groove between the upper and lower large diameter portions, and a return fluid groove formed on the lower the large diameter portion, a fluid circuit unit to control a supply direction of the fluid to the cylinder and to generate a fluid pressure to selectively change a stroke, and a chisel to break the bedrock when a lower portion of the piston descends to impact the chisel during a descending operation.

A motor control device, includes a pressure command unit calculating a pressure command for commanding pressure generated in a pressure control object, a pressure detection unit detecting the pressure generated in the pressure control object, a pressure control unit calculating a speed command for pressure control for the servo motor, based on the calculated pressure command and the detected pressure, and a servo control unit controlling speed of the servo motor, based on the calculated speed command. The pressure control unit performs an integral operation. When a direction of increasing pressure in the integral operation is defined as a positive direction in the integral operation, and a direction of decreasing the pressure is defined as a negative direction, a median between an upper limit in the positive direction and a lower limit in the negative direction in the integral operation is larger than zero.

The underlying invention relates particularly to a hydraulic forming machine, more particularly a forging hammer, for workpiece forming, comprising a hydraulic cylinder for driving a ram configured for workpiece forming, and a hydraulic circuit configured for operation of the hydraulic cylinder, wherein the hydraulic circuit has an actuator with an adjustably variable volume flow via which a first hydraulic working chamber of the hydraulic cylinder, used to accelerate the ram during the execution of a working stroke (A) for workpiece forming, can be provided with hydraulic fluid. The hydraulic circuit is configured to adjust and vary the volume flow of the valve or actuator, depending on a setpoint speed (Vsoll) of the ram to be achieved in an acceleration phase of a working stroke (A), and to optimize the subsequent movement phase.