when the mechanical pressure machine works, the motor drives the large pulley through the v-belt, drives the crank slider mechanism through the gear pair and the clutch, so that the slider and the punch die go down. after the forging work is completed, the slide returns upward, and the clutch is automatically disengaged, and at the same time, the robot on the crank shaft is connected, so that the slide stops near the top dead center. when the mechanical press is working, the motor drives the large pulley through the v-belt and drives the crank slider mechanism through the gear pair and the clutch to make the slider and the punch line go down. after the forging work is completed, the slide returns upward, and the clutch is automatically disengaged, and at the same time, the robot on the crank shaft is connected, so that the slide stops near the top dead center.
the essence of roll forging deformation is the rolling extension of the billet, and the section of the billet is smaller and the length is increased. when the deformation of the section is large, it needs to be completed by several rolling passes through several passes. the process design is mainly to reasonably determine the amount of roll forging, the amount of stretching, and the amount of extension deformation for each step of the roll forging. they depend on the size of the roll diameter, the shape and size of the hole shape, the temperature of the blank, and deformation conditions such as cooling and lubrication. some double-support roller forging machines have a roller shaft protruding at one end. this is a composite roller forging machine combined with a cantilever type and a double-support type. it can not only realize longitudinal roller forging but also complete horizontal widening at the cantilever end. in mass production of roll forging, robots are widely used to transfer workpieces to automate production processes, increase productivity, and reduce labor intensity.
the billet placed in the female die is pressed with a punch to cause a plastic flow to obtain a forging method corresponding to the shape of the die hole or the concave-convex die. when extruding, the blank produces three-dimensional compressive stress, and even plastic blanks can be extruded. extrusion, especially cold extrusion, high material utilization, improved material structure and mechanical properties, simple operation, high productivity, can produce long rods, deep holes, thin-walled, special-shaped section parts, is an important little cutting processing technology. extrusion is mainly used for metal forming, but also for non-metal forming such as plastic, rubber, graphite and clay blanks.
each crank slider mechanism is referred to as a "point." the simplest mechanical press uses a single-point type, ie, only one crank-slider mechanism. some large working face mechanical presses use two or four points for uniform force and smooth movement of the bottom surface of the slider.
the load of a mechanical press is impactful, that is, the time for forging work in one working cycle is very short. the short-term maximum power is more than ten times larger than the average power, so a flywheel is provided in the transmission system. after the motor selected according to the average power is started, the flywheel runs to the rated speed and accumulates kinetic energy. after the punch contacts the billet to start the forging work, the driving power of the motor is less than the load, the rotation speed is reduced, and the flywheel releases the accumulated kinetic energy to compensate. after the forging work is completed, the flywheel accelerates the accumulated kinetic energy again to prepare for the next use.
there is a mechanical or electrical interlock between the clutch and the brake on the mechanical press to ensure that the brake is released before the clutch is engaged and the brake must be disengaged before the brake is applied. the operation of the mechanical press is divided into continuous, single stroke and jog, most of which are achieved by controlling clutches and brakes. the stroke length of the slider does not change, but the distance between the bottom surface and the working surface can be adjusted by the screw.
in production, there may be more than the nominal working force of the press. to ensure equipment safety, overload protection devices are often installed on the press. in order to ensure the safety of the operator, there is a photoelectric or two-handed personal protection device on the press.
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