An annular reference surface is formed around a through-hole of an eye portion. A distal-end-side curved portion is formed at a first corner portion, on an outer side of the annular reference surface. The thickness of the distal-end-side curved portion is reduced in a range of a length from the first flat surface toward the distal end surface. A hole-side curved portion whose thickness is reduced toward an inner surface of the through-hole is formed at a second corner portion, on an inner side of the annular reference surface. The length of the hole-side curved portion is less than the length of the distal-end-side curved portion. The hole-side curved portion is curved with a greater curvature than that of the distal-end-side curved portion.

An annular reference surface is formed around a through-hole of an eye portion. A distal-end-side curved portion is formed at a first corner portion, on an outer side of the annular reference surface. The thickness of the distal-end-side curved portion is reduced in a range of a length from the first flat surface toward the distal end surface. A hole-side curved portion whose thickness is reduced toward an inner surface of the through-hole is formed at a second corner portion, on an inner side of the annular reference surface. The length of the hole-side curved portion is less than the length of the distal-end-side curved portion. The hole-side curved portion is curved with a greater curvature than that of the distal-end-side curved portion.

A method of processing a material by use of high kinetic energy comprises a piston driven from a start position by a hydraulic system pressure by a drive chamber, by only one stroke, to transfer high kinetic energy to a blank/tool to be processed, whereafter there is a risk that a rebound of the piston will occur, so a step is taken in connection with said stroke performed, to prevent said piston from making a rebound with an essential content of kinetic energy to avoid negative effects as a result, whereafter the piston is returned to said start position by means of a second chamber, wherein a valve means closes the driving connection between the system pressure and the piston, the valve means is controlled by a pilot valve controlling the entire striking progress, and the second chamber is pressurized with the system pressure during the entire striking progress.

A method of processing a material by use of high kinetic energy comprises a piston driven from a start position by a hydraulic system pressure by a drive chamber, by only one stroke, to transfer high kinetic energy to a blank/tool to be processed, whereafter there is a risk that a rebound of the piston will occur, so a step is taken in connection with said stroke performed, to prevent said piston from making a rebound with an essential content of kinetic energy to avoid negative effects as a result, whereafter the piston is returned to said start position by means of a second chamber, wherein a valve means closes the driving connection between the system pressure and the piston, the valve means is controlled by a pilot valve controlling the entire striking progress, and the second chamber is pressurized with the system pressure during the entire striking progress.

The present invention relates to a method at the material processing by the use of high kinetic energy, comprising a piston which is driven from a start position by a hydraulic system pressure (pS) by means of a drive chamber in order, by only one stroke, to transfer high kinetic energy to a blank/tool to be processed, whereafter there is a risk that a rebound of the piston will occur, and the method comprises that a step is taken in connection with said stroke performed, which step prevents said piston from making a rebound with an essential content of kinetic energy in order to avoid negative effects as a result of a rebound, whereafter the piston is returned to said start position by means of a second chamber, wherein said step comprises that a valve means closes the driving connection between the system pressure (pS) and the piston, wherein said step comprises that said valve means is controlled by a pilot valve controlling the entire striking progress, and that said second chamber is pressurized with the system pressure (pS) during the entire striking progress.

The present invention relates to a method at the material processing by the use of high kinetic energy, comprising a piston which is driven from a start position by a hydraulic system pressure (pS) by means of a drive chamber in order, by only one stroke, to transfer high kinetic energy to a blank/tool to be processed, whereafter there is a risk that a rebound of the piston will occur, and the method comprises that a step is taken in connection with said stroke performed, which step prevents said piston from making a rebound with an essential content of kinetic energy in order to avoid negative effects as a result of a rebound, whereafter the piston is returned to said start position by means of a second chamber, wherein said step comprises that a valve means closes the driving connection between the system pressure (pS) and the piston, wherein said step comprises that said valve means is controlled by a pilot valve controlling the entire striking progress, and that said second chamber is pressurized with the system pressure (pS) during the entire striking progress.

In a forming process with a press having in a frame a ram closing through the force of a cylinder with a moveable piston against a press table in a straight-line movement, the piston initially acts upon at least one knuckle joint system during the closing of the press, and a hydraulic cushion of the ram concludes the closing process with extension of the knuckle joint system in movement direction of the piston and straight-line support thereof against the frame. In a press having in a frame a ram closing through the force of a cylinder with a moveable piston against a press table in a straight-line movement, the ram is connected so as to be fixed with respect to the frame via at least two identically constructed knuckle joint systems, and the ram has a hydraulic cushion.

In a forming process with a press having in a frame a ram closing through the force of a cylinder with a moveable piston against a press table in a straight-line movement, the piston initially acts upon at least one knuckle joint system during the closing of the press, and a hydraulic cushion of the ram concludes the closing process with extension of the knuckle joint system in movement direction of the piston and straight-line support thereof against the frame. In a press having in a frame a ram closing through the force of a cylinder with a moveable piston against a press table in a straight-line movement, the ram is connected so as to be fixed with respect to the frame via at least two identically constructed knuckle joint systems, and the ram has a hydraulic cushion.

A forming machine, particularly a ring-rolling machine, which includes a hydraulically regulated linear axle, which is driven by way of an electro-hydrostatic actuator, can work precisely while having a simple mechanical-engineering structure. The machine may have at least one further hydraulically regulated linear axle, which is driven by way of an electro-hydrostatic actuator or by way of a drive other than an electro-hydrostatic actuator.

A forming machine, particularly a ring-rolling machine, which includes a hydraulically regulated linear axle, which is driven by way of an electro-hydrostatic actuator, can work precisely while having a simple mechanical-engineering structure. The machine may have at least one further hydraulically regulated linear axle, which is driven by way of an electro-hydrostatic actuator or by way of a drive other than an electro-hydrostatic actuator.