The invention relates to a drive device (19) for a secondary drive of a press and in particular of a drawing press (10). The drive device (19) serves in particular as a bed cushion drive. It has an electric linear motor (27), the rotor (46) of which is rigidly connected to a transmission piston (35) of a fluidic transmission unit (28). The fluidic transmission unit has a first pressure chamber (38a), which is connected via a first fluid line (39) to a first working chamber (41) of a working cylinder (29). The fact that the piston area (F1) of the transmission piston (35) that is adjacent to the first pressure chamber (38a) is smaller than the piston area (F3) of the working piston that is adjacent to the first working chamber (41) means that an increase in the force of the linear motor (27) by a factor corresponding to the ratio of the areas is achieved. This allows the forces necessary at the working cylinder (29) to be achieved with the aid of the linear motor (27).
B30B 1/34 - Presses, using a press ram, characterised by the features of the drive therefor, pressure being transmitted directly, or through simple thrust or tension members only, to the press ram or platen by plungers under fluid pressure involving a plurality of plungers acting on the platen
B30B 1/32 - Presses, using a press ram, characterised by the features of the drive therefor, pressure being transmitted directly, or through simple thrust or tension members only, to the press ram or platen by plungers under fluid pressure
B21D 24/10 - Devices controlling or operating blank holders independently, or in conjunction with dies
B21D 24/14 - Devices controlling or operating blank holders independently, or in conjunction with dies pneumatically or hydraulically
2.
Hydraulic cylinder for a hydraulic drawing cushion
The invention resides in a hydraulic cylinder (23) for a hydraulic drawing cushion (20) of a drawing press (10). The hydraulic cylinder (23) includes a first operating chamber (47), a second operating chamber (48), and a third operating chamber (53). An annular piston (45) with a first piston surface area (49) and a second piston surface area (50) separates the first operating chamber (47) from the second operating chamber (48). The first and the second piston surfaces (49, 50) have the same size. A front surface of the piston rod (33) forms a third piston surface (54) which is larger than the first and second piston surfaces. The third piston surface (54) delimits the third operating chamber (53) of the hydraulic cylinder (23). The first and the second operating chambers (47, 48) are provided for controlling the position and/or the movement of the piston rod (33). The third operating chamber (53) serves to control the metal sheet clamping force of the drawing press via the piston rod (33).
F15B 11/036 - Systems essentially incorporating special features for controlling the speed or the actuating force or speed of an output member for controlling the actuating force by means of servomotors having a plurality of working chambers
The invention relates to a compactor having an electric direct drive, wherein motion transfer means, such as, for example, pinions or transmissions, may be omitted, and wherein the electric direct drive is located between an eccentric (3) and a piston rod (6) and brings about a relative movement between the eccentric (3) and the piston rod (6).
B30B 1/26 - Presses, using a press ram, characterised by the features of the drive therefor, pressure being transmitted directly, or through simple thrust or tension members only, to the press ram or platen by cams, eccentrics, or cranks
H02K 7/075 - Means for converting reciprocating motion into rotary motion or vice versa using crankshafts or eccentrics
The invention relates to a tool changing system for presses. In said tool changing system, several wedge-shaped sliding elements clamp and lock a tool in a holder by means of a clamping ring.
patents
