Take You a Comprehensive Understanding of Forging Press

Forging presses are equipment for the cold working of metals and machinery, which only change the outer shape of the metal. Forging presses include plate bending machines, shears, punches, presses, hydraulic presses, hydraulic presses, bending machines, etc.

● Classification:

Roll Forging Press

A forging method in which a metal blank passes through two relatively rotating fan-shaped dies to produce plastic deformation to form a workpiece. It is a special form of forming rolls. Roll forging can be used to produce connecting rods, twist drills, wrenches, spikes, hoes, picks, and turbine blades. The roll forging process uses the rolling forming principle to gradually deform the blank. Compared with ordinary die forging, it has the advantages of simpler equipment structure, stable production, low vibration and noise, easy automation, and high production efficiency. Roll forging is divided into two types: blank roll forging and forming roll forging. Blank-making roll forging is to prepare blanks of required shape and size for die forging; forming roll forging can directly produce forgings that meet the requirements of shape and size.

Mechanical Pressure Forging Press

The mechanical pressure forging machine converts the rotary motion of the motor into the linear reciprocating motion of the slider through the crank slider mechanism and forms the forging machine of the blank. Mechanical presses are stable in action and reliable in work. They are widely used in stamping, extrusion, die forging, and powder metallurgy processes. Mechanical presses account for more than half of the total number of forging machines. The specifications of the mechanical press are expressed by the nominal working force, which is the maximum working force designed based on the calculation base point when the slider moves to about 10-15 mm from the bottom dead center of the stroke.

Extrusion Forging Press

Hot extrusion forging presses are widely used in the production of aluminum, copper, and other non-ferrous metal pipes and profiles, etc., belonging to the metallurgical industry. Hot extrusion of steel is not only used to produce special pipes and profiles but also to produce solid and core carbon steel and alloy steel parts that are difficult to be formed by cold or warm extrusion, such as rods with thick heads. , Barrels, containers, etc. The cold extrusion forging machine was originally only used to produce pipes and profiles of lead, zinc, tin, aluminum, copper, etc., as well as parts such as toothpaste hoses, dry battery shells, and bullet shells. The cold extrusion operation is simple, suitable for the mass production of smaller parts.

Spiral Forging Press

The screw forging press uses screw and nut as the transmission mechanism and uses the screw transmission to convert the forward and reverse rotation movement of the flywheel into the up and down reciprocating movement of the slider. The screw press is usually driven by a motor through a friction disc to rotate the flywheel rim. Therefore, this type of press is also called a friction press. The largest friction press in China is 25 MN. Later, an electric screw press that uses a motor to directly drive the flywheel appeared. It has a compact structure and few transmission links. Due to frequent commutation, it has higher requirements for control appliances and requires a special motor.

● Mechanical Structure:

Stamping Die Set

The stamping die set is the most typical functional part of the forging press, and it is the first to realize standardization and specialized production. Punching, blanking, stretching, cutting, and other stamping processes on a machine tool press are inseparable from stamping dies. The punch and die of the working part of the stamping die are installed on the stamping die set. Different punching processes require different punches and die, but the same stamping die set can be used. The stamping die set is composed of an upper template, a lower template, a guidepost, and a guide sleeve. A series of products for different specifications and models of presses have been developed. The stamping die set below the medium specifications has been standardized.

Brake

Among the functional parts of forging presses, considering the maturity of its development, production, and use, friction clutch-brake for machine tool presses is the first to be promoted. Friction clutch-brake is an important part of the main drive of machine tool presses, and its performance directly affects the usability, safety, reliability of the whole machine, as well as the operating rate and maintenance of the equipment. According to the structure of friction clutch-brake, there are combined friction clutch-brake and separate friction clutch-brake; according to the working state of the friction pair, there are dry friction clutch-brake and wet friction clutch-brake; according to friction clutch -The brake control system is divided into pneumatic friction clutch-brake and hydraulic friction clutch-brake.

Photoelectric Safety Protection Device

Photoelectric safety protection device, invisible infrared light curtain is set in the protection area between the operator of the forging press and the dangerous working area. Once a certain part of the operator enters the protection area to block the light curtain, the control system outputs a signal to the safety actuator of the forging press, Make the forging press stop emergency to prevent dangerous actions from happening. It can be seen that the photoelectric safety protection device itself cannot directly protect the operator. It only sends a signal to the machine tool to stop dangerous actions before a safety accident may occur. Therefore, strictly speaking, the optoelectronic safety protection device should be called the optoelectronic safety protection control device.

Photoelectric safety protection devices are usually divided into two types: reflective type and through-beam type. The reflective photoelectric safety protection device is composed of a controller, a sensor, and a reflector. The light curtain is emitted by the sensor, and then reflected back to the sensor to be received by the reflector; the through-beam photoelectric safety protection device is composed of a controller, a transmitting sensor, and a receiving sensor It consists of 3 parts, the light curtain is emitted by the transmitting sensor and received by the receiving sensor.

Cam Controller

The cam controller is an important part of the electrical control system of the machine tool press. The method to deal with the logical relationship of the working mechanism is usually to allocate 360° of the crankshaft one revolution, work out the working cycle diagram of the machine tool press, and control the actions of each working mechanism. The cam controller is the actuator that distributes the rotation angle of the crankshaft. The cam controller is installed on the shaft that rotates synchronously with the crankshaft, and the working mechanism sequentially produces prescribed actions to complete a working cycle of the machine tool press. There are many professional manufacturers of cam controllers in China, and the quality of their products is generally stable and reliable.

Automatic Feeding Device

There are various automatic feeding devices in the forging press, here it refers to the automatic feeding device used for single-machine or stamping automatic lines such as open press, closed press, multi-station press, high-speed press, etc. for sheet metal processing. The automatic feeding device is generally composed of three parts: a material rack, an uncoiling and leveling mechanism, a pneumatic clamp-type feeding mechanism, and a scrap rewinding rack. The material rack and the uncoiling and leveling mechanism have the functions of supporting the coil, uncoiling, and leveling. The uncoiling mechanism loosens the coil a little and presents a free-hanging state to reduce the pulling force of the feeding mechanism during the feeding process, which is beneficial to improve the feeding accuracy. The leveling mechanism uses multiple rollers to apply force to the uncoiled coil so that the plate can be corrected before stamping, which is beneficial to improve the accuracy of the product. The pneumatic clamp-type feeding mechanism is powered by compressed air to control the opening and closing of the clamp and the reciprocating motion to complete the feeding of the sheet. The stroke of the reciprocating motion is steplessly adjustable to meet the requirements of different feeding lengths. The scrap rewinding rack rewinds the stamped waste tape. If the waste tape is cut and recycled during stamping, this part is not needed.

● Working Principle:

When the mechanical press machine 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, so that the slider and the punch go straight down. After the forging work is completed, the slider moves upward, the clutch is automatically disengaged, and the automatic on the crankshaft is turned on to stop the slider 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, so that the slider and the punch go straight down. After the forging work is completed, the slider moves upward, the clutch is automatically disengaged, and the automatic on the crankshaft is turned on to stop the slider near the top dead center.

The essence of roll forging deformation is the rolling extension of the billet, and the section of the billet becomes smaller and the length increases. When the cross-section deformation is large, it needs to be completed by several passes through multiple rolls. The process design is mainly to reasonably determine the reduction, expansion, and extension deformation of each step of the roll forging. They depend on the size of the roll diameter, the shape, and size of the hole, the temperature of the blank, and the deformation conditions such as cooling and lubrication. Some double-backed roll forging machines have a roll shaft extending at one end. This is a composite roll forging machine that combines cantilever and double-backed types. It can not only realize longitudinal roll forging but also complete horizontal widening and forming at the cantilever end. In mass roll forging production, manipulators are widely used to transport workpieces to realize the automation of the production process, increase productivity, and reduce labor intensity.

A convex mold is used to pressurize the blank placed in the concave mold to generate plastic flow, thereby obtaining a forging method corresponding to the shape of the hole of the mold or the shape of the concave and convex mold. When extruding, the billet generates three-dimensional compressive stress, and even the billet with lower plasticity can be extruded into shape. Extrusion, especially cold extrusion, has high material utilization, improved material organization, and mechanical properties, simple operation, high productivity, and can produce long rods, deep holes, thin-walled, and special-shaped cross-section parts. It is important to avoid cutting. Processing technology. Extrusion is mainly used for the forming of metals, but also for the forming of non-metals such as plastics, 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 a crank slider mechanism. Some large working surface mechanical presses adopt double-point or four-point machines to make the bottom surface of the slider evenly stressed and move smoothly.

The load of the mechanical press is impactful, that is, the forging work time is very short in a working cycle. The short-term maximum power is more than ten times larger than the average power, so flywheels are installed 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 blank to start the forging work, 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 again to accumulate kinetic energy 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 must be released before the clutch is engaged, and the clutch must be released before the brake is applied. The operation of the mechanical press is divided into continuous, single stroke, and inching (inching), most of which are realized by controlling the clutch and brake. The stroke length of the slider remains unchanged, but the distance between the bottom surface and the working surface (called the sealing height) can be adjusted by the screw.