TFS Furniture Accessories-Punch Process

2022-06-11 10:08:09 admin

A punch press is a machine that uses pressure to deform metal to punch it into various required structures. The functions of punching machines include punching and shearing, forming, deep drawing, and metal forging. They are generally used in conjunction with molds and are important equipment for producing metal mechanical parts.


The punch press can be divided into mechanical punch press and hydraulic punch press according to the power source of the slider.


The most common mechanical punch uses a motor-driven crankshaft (or connecting rod, eccentric gear or toggle joint) to move the slider, while the hydraulic punch uses a hydraulic cylinder to drive the slider. The drive system characteristics of the punch determine the speed and force applied during each part of the stroke. The advantage of the hydraulic punch is that the pressure is fixed during the impact process. The mechanical punch depends on the system, the further down the dead center, the greater the force. If the same time is considered, mechanical punches can impact more times and are more commonly used in industrial applications.


Most traditional mechanical punches use induction motors. The early mechanical punches were driven by VS motors, and the torque was adjusted by adjusting the current of the coupling machine. Later, the induction motors were also driven by frequency converters. There is a flywheel as an energy storage element in a punch using an induction motor. Whether it is processed or not, the flywheel will continue to run. When processing, the clutch is used to make the flywheel drive the slider to run.


Later, servo punches with servo motors as the power source were also used. Servo punches did not require flywheel energy storage, and the drive would only run when processing. Moreover, the speed curve of the slider at different positions could be determined according to the processing characteristics, which could carry out more difficult processing.


The power source of the mechanical punch is the motor, and a transmission mechanism is required in the middle to convert the rotary motion into the reciprocating linear motion of the slider. The characteristics of the punching machine will also vary according to the transmission mechanism.


The most common mechanical punch is driven by a crankshaft (a shaft with an eccentric), and this type of transmission is also suitable for many different kinds of machining.


The connecting rod type punch is based on the connecting rod as the transmission mechanism. The characteristics of the connecting rod type punch are that the slider can be lowered quickly, processed at a slow speed, and raised quickly, saving time and cost, and has a large output near the bottom dead center.


The toggle type punch is based on the toggle joint as the transmission mechanism. When the slider moves to the bottom (called the bottom dead center), it has the characteristic of a short stay, which is suitable for cold forging. There are also toggle punches that combine connecting rods and toggles.


Another classification of punch presses are single-action punches and double-action punches (there are also triple-action punches, but they are very rare). The single-action punch has only one slider, while the double-action punch has two sliders. One slider can fix the workpiece to prevent wrinkles, and then a slider is used for stamping processing, which is suitable for deep drawing of rigid materials.


The important parts of the punch are die pad (bolster plate) and slider (ram).


The die pad (bolster plate) is a large piece of metal on which the lower die of the die is fixed. During the punching process, the die pad is stationary. Larger presses (like those used in the automotive industry) will have a die cushion in the die pad, which is required for deep drawing with a single stroke.


The slider is also a large piece of metal, which is connected to the upper die of the die, and will move up and down when the punch is processed.


The punching machine is usually connected to an automatic feeder electronically (for example, with a programmable controller) or mechanically, which can control the feeding of raw materials. If the raw material is a whole roll of steel sheet, it will be unrolled first, and then enter the mold after passing through the straightener. Some punches are also equipped with a tonnage display, which can display the force of each impact.


The punch press has its dangers. If the punch press works and the slider slides down, the operator's hand or other parts are still in the die, which may cause casualties. Therefore, other security measures are required. The method of intrinsically safe design is to allow the start of the punch press to have two buttons far enough apart, which requires the operator to press both hands to start, so as to avoid the operator's hands being injured in the die when the punch press starts.


Another method is to install a safety grating, and if the operator is within the working range of the die, the punch will be forced to stop.


Dongguan TFS Furniture Accessories Co., Ltd. can undertake processing orders for various iron pieces and other hardware punch presses.