What is a Forging Press?

Forging presses are equipment for cold working of metals and machinery. It only changes the shape of the metal. Forging presses include plate rolling machines, shearing machines, punches, presses, hydraulic presses, hydraulic presses, bending machines, etc.

When the mechanical pressure machine tool works, a large pulley (usually also a flywheel) is driven by a motor through a V-belt, and the crank slider mechanism is driven by the gear pair and the clutch, so that the slider and the punch die go straight down. After the forging work is completed, the slider goes up and the clutch automatically disengages. At the same time, the automaton on the crank shaft is turned on, so that the slider stops near the top dead center. When the mechanical press is working, a large pulley (usually also acting as a flywheel) is driven by a motor through a V-belt, and the crank slider mechanism is driven by the gear pair and the clutch, so that the slider and the punch die go straight down. After the forging work is completed, the slider goes up and the clutch automatically disengages. At the same time, the automaton on the crank shaft is turned on, so that the slider stops near the top dead center.

The essence of roll forging deformation is the rolling extension of the billet, and the cross section of the billet part becomes smaller and the length increases. When the cross-sectional deformation is large, it needs to be completed by several passes through multiple rolling. Its process design is mainly to reasonably determine the rolling reduction, stretching and extension deformation of each step. They depend on the size of the roll diameter, the shape and size of the hole pattern, the temperature of the blank and the deformation conditions such as cooling and lubrication. Some double-support roll forging machines have a roll shaft protruding at one end. This is a composite roll forging machine combining a cantilever type and a double-support type. It can achieve both longitudinal roll forging and lateral widening at the cantilever end. In large-scale roll forging production, robots are widely used to transport workpieces to automate the production process, improve productivity, and reduce labor intensity.

A male die is used to press the blank placed in the female die to cause plastic flow, so as to obtain a forging method of a part corresponding to the shape of the die hole or the concave-convex die. When extruded, the billet generates three-dimensional compressive stress, and even the billet with lower plasticity can be extruded. Extrusion, especially cold extrusion, has high material utilization, improved structure and mechanical properties of the material, simple operation and high productivity. It can make long rods, deep holes, thin walls, and special-shaped cross-section parts. It is important to have no cutting. Processing technology. Extrusion is mainly used for metal forming, and it can also be used for non-metal forming such as plastic, rubber, graphite and clay blanks.

Each crank slider mechanism is called a "point". The simplest mechanical press uses a single point type, that is, there is only one crank slider mechanism. Some large working surface mechanical presses adopt two-point or four-point in order to make the bottom surface of the slider be uniformly stressed and move smoothly.

The load of a mechanical press is impact, that is, the time of forging work in a working cycle is very short. The short-term maximum power is more than ten times greater than the average power, so a flywheel is provided in the transmission system. After the electric motor selected according to the average power starts, the flywheel runs to the rated speed and accumulates kinetic energy. After the punch contacts the billet and starts forging, the driving power of the motor is less than the load, the speed is reduced, and the flywheel releases the accumulated kinetic energy to compensate. After the forging work is completed, the flywheel accelerates to accumulate kinetic energy again for next use.

There is a mechanical or electrical interlock between the clutch and the brake on the mechanical press to ensure that the brake must be released before the clutch is engaged, and the clutch must be disengaged before the brake is applied. The operation of the mechanical press is divided into continuous, single stroke and jog (micro-motion), most of which are achieved by controlling the clutch and brake. The stroke length of the slider is unchanged, but the distance between the bottom surface and the working surface (called the sealing height) can be adjusted by the screw.

In production, the phenomenon of exceeding the nominal working force of the press may occur. To ensure the safety of the equipment, overload protection devices are often installed on the press. In order to ensure the safety of the operator, the press is equipped with a photoelectric or two-handed personal protection device. ^[2]

1. The operator must pass the examination and hold the "equipment operation certificate" of this equipment to operate this equipment.

2. Do it carefully before work:

(1) Read the shift record carefully to understand the work of the previous shift.

(2) Check whether the equipment and work site are cleaned and wiped clean; the equipment bed, work surface, guide rails, and other major sliding surfaces must be free of obstacles, impurities, and new pulling, grinding, and injury. If the above situation must be cleared and the equipment cleaned; if there is a new pull, grind or bump, please ask the equipment staff or team leader to check it together and make a record.

(3) Check that the handles, valves, rods, and main parts and components (sliders, hammers, tool holders, etc.) of each operating mechanism should be placed in non-working positions as specified in the instructions.

(4) Check that all safety protection devices (protective cover, limit switch, limit stop iron, electrical grounding, safety device, etc.) should be complete and installed correctly and reliably; distribution box (box), fuel tank (pool), transmission The door cover should be closed.

(5) Check that the lubricating parts (oil sump, oil tank, oil cup guide and other sliding surfaces) have sufficient oil, and refuel according to the lubrication chart.

(6) Check all main parts, components and fasteners for abnormal looseness.

(7) Open the gas (steam) valve, check that the pipeline valves and other devices are intact and free of leakage, and that the gas (steam) and pressure are in accordance with the regulations, and drain the accumulated water in the pipe.

(8) Perform a dry run test, start jogging, check each operating device, safety insurance device (braking, reversing, interlocking, limit, insurance, etc.) and indicate devices (indicating meters, indicators, etc.) should work Sensitive, accurate and reliable; the movements of all parts should be coordinated; the oil supply should be normal and the lubrication should be good; the machine should run without abnormal sounds, vibrations, temperature rises, odors, smoke and other phenomena. Make sure everything is working properly before starting work. For the equipment that works in shifts, the shift staff shall jointly inspect and perform the shift in accordance with the above (Article 8); if the equipment that shifts between shifts is found to have seriously violated the operating rules of the previous shift, the equipment staff or the team leader should always check it. And record the case, otherwise equipment problems occur in this class violates the operating procedures. After the equipment has been adjusted or overhauled, the operator must also inspect the equipment in accordance with the requirements and procedures above (8), and confirm that everything is correct before starting work.

3. Do it carefully at work:

(1) Adhere to the work position, carefully operate the equipment, and do not do anything unrelated to the work. When leaving the equipment due to accidents, stop the machine and turn off the electricity and gas (steam) sources.

(2) Use the equipment in accordance with the technical specifications specified in the instructions, and do not use the equipment beyond the specifications and overload.

(3) Pay close attention to the lubrication of various parts of the equipment, and refuel during the shift according to the lubrication instruction chart to ensure that the various parts of the equipment are well lubricated.

(4) Pay close attention to the working conditions of all parts of the equipment. If there are abnormal sounds, vibrations, temperature rises, odors, smoke, uncoordinated movements, malfunctions, etc., stop the machine immediately to check and eliminate the work before continuing.

(5) Adjust the speed, replace the mold, cutter or wipe test. When servicing the equipment, stop it beforehand and turn off the power supply of gas and steam.

(6) During work, it is not allowed to disassemble the safety protection device and open the door of the power distribution box (box), oil tank (box), and gearbox for work without authorization.

(7) The equipment must be shut down immediately when an accident occurs, protect the site, and report to the relevant departments for analysis and processing.

4. After work, do it carefully:

(1) All operating devices, sliders, hammers, knife holders, etc. should be placed in a non-working position according to the instructions; turn off the electricity, gas (steam) source.

(2) Organize tools, parts and work sites.

(3) Clean the material head, material edge, oxide scale, sundries, etc. on the work site and equipment; wipe and clean all parts of the equipment, and protect the sliding surfaces with oil.

(4) Fill in the handover list. ^[3]

External overall inspection

Thoroughly clean the outside of the forging press, check whether all the fastening screws are loose, whether each part is safe, and whether there are open welding, cracks or deformation. There should be safety warning signs on the fuselage, and the length should be no less than 30 cm.

Test run check

After the forging press rotates, check for air leakage, and at the same time, check for abnormal vibration of the machine, and perform full lubrication as required. Carefully observe for collisions, friction and stagnation. Is there any abnormal sound? Use power machinery to drive low-speed operation and observe the operation status of each part.

Inspection of input devices

The conveyor chain must be inspected section by section, and if it is found to be severely worn, deformed, or cracked, it should be replaced. The tension of the feeding chain should be consistent from left to right. It is advisable that the middle of the chain length slightly touches the bottom plate. The main and passive axes of the conveying chain should be parallel. If the chain is inclined, the cause should be found and eliminated.

Inspection of clutch device

The safety clutch should be adjusted during work and use, check the wear of the wave tooth, and it should be replaced when the tooth height is worn away by 1/3.

Inspection and adjustment of forging parts

Carry out the pressure test of the whole machine. The pressure used in the test is 1.25 times the working pressure. Check that the piston extends to the maximum working stroke. Hold the pressure for 15 minutes. The drop in the pressure gauge reading should not exceed 4% of the test pressure. No leakage; after all pressure is removed, the pressure gauge pointer returns to the "0" position, the parts should be undamaged, the pull rod must not be significantly deformed, and the moving parts should not be stuck. Perform a reliability test on the safety valve, adjust the safety valve to the working pressure (upper left +5, lower left + 1) MPa, test continuously for 5 times, and the needle valve is sensitive to open and close. Rated working pressure. ^[1]