Servo Presses

1. Overview and Characteristics

Controlling the speed of a pressurization unit and the pressurization count of a press was considered difficult with conventional machines. However, with the emergence of the servo press in the 1990s, complex press control became possible through the adoption of CNC and servo motors. With a servo press, operators can set the processing speed, position, and pressure using numerical values.
For example, when stamping sheet metal using a complex die, if the processing speed is constant, excessive force may be applied to certain parts of the sheet metal, resulting in poor forming. For this reason, the processing speed was decreased with conventional presses to carefully stamp the materials, which hindered productivity.
The servo press works around this problem by driving the press at high speed mid-way through the stamping motion and lowering the speed close to the bottom dead center (bottommost point of pressurization). This consequentially offers both improved yield rate and productivity.

2. Forming Difficult Workpieces

With the ability to set pressurization options as needed, servo presses make it possible to form materials considered impossible or difficult to form using conventional presses, in addition to providing improved quality and efficiency. Notably, servo presses have become essential in forming aluminum, titanium, and magnesium alloys, carbon fiber reinforced plastics, and high-tension steel plates that are becoming a common material for automobile body components for which lighter weights are key.
Servo presses not only make it possible to form materials conventionally considered difficult to process, but they also offer a number of other benefits including higher forming precision, higher productivity, greater noise reduction, and improved energy savings. Because of these characteristics, more manufacturers are turning to servo presses instead of conventional presses.

Basic structure of a servo press
Basic structure of a servo press
Servo panel
Servo amplifier that controls the pressurizing unit
Feedback of operation signals
Controls the speed and force of pressurizing unit
Servo motor
Pressurizing unit