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Hydraulic Press Machine

What Is Hydraulic Press Machine?Hydraulic Press Machine(a kind of hydraulic machine) is a kind of special hydraulic oil as the working medium, the hydraulic pump as the power source, and the hydraulic oil enters the cylinder/piston through the hydraulic pipeline by the force of the pump, and then the cylinder/piston There are several sets of seals that cooperate with each other, and the seals at different positions are different, but they all play a sealing role to prevent the hydraulic oil from leaking.

Finally, through the one-way valve, the hydraulic oil is circulated in the oil tank to make the cylinder/piston cycle to perform work to complete a certain mechanical action as a kind of machinery for productivity.

Structure of Hydraulic Press Machine

Hydraulic Press Machine is composed of two parts: the main engine and the control mechanism. The main part of the Hydraulic Press Machine includes the main body, main cylinder, ejector cylinder and liquid filling device, etc. The power mechanism is composed of a fuel tank, a high-pressure pump, a low-pressure control system, an electric motor, and various pressure valves and directional valves. Under the control of the electric device, the power mechanism realizes the conversion, adjustment and delivery of energy through pumps, cylinders and various hydraulic valves to complete the cycle of various technological actions.

Classification of Hydraulic Press Machine

Hydraulic Press Machine is classified by structure

It is mainly divided into: four-column Hydraulic Press Machine (three-beam and four-column type, five-beam and four-column type), double-column Hydraulic Press Machine, single-column Hydraulic Press Machine (C-shaped structure), frame type Hydraulic Press Machine, etc.

Classified by use of Hydraulic Press Machine

Mainly divided into metal forming Hydraulic Press Machine, bending Hydraulic Press Machine, stretching Hydraulic Press Machine, punching Hydraulic Press Machine, powder (metal, non-metal) forming Hydraulic Press Machine, pressing Hydraulic Press Machine, extrusion Hydraulic Press Machine , Extrusion and so on.

Features of Hydraulic Press Machine

The Hydraulic Press Machine directly driven by the pump has the following characteristics

  • 1. The stroke speed of the hydraulic press machine movable beam depends on the liquid supply of the pump, and has nothing to do with the deformation resistance of the forging during the process. If the liquid supply of the pump is constant, the working speed of the Hydraulic Press Machine is a fixed value.
  • 2. The supply pressure and the power consumed by the pump are related to the deformation resistance of the workpiece to be processed. The working deformation resistance is large, and the supply pressure and the consumed power of the pump are also large, and vice versa.
  • 3. The characteristics of the constant stroke speed of the movable beam and the change of the pump supply pressure can be used as a signal for operating the distributor to realize the automatic control of the Hydraulic Press Machine.
  • 4. The basic investment is low, the area is small, and the daily maintenance and maintenance are simple. The hydraulic pumps in the direct drive system of the pump are all selected according to the maximum working speed and working pressure of the Hydraulic Press Machine, and the hydraulic pump cannot be obtained when the hydraulic press machine has a small filling stroke, return stroke, auxiliary process and required working pressure. Make full use, especially the large-tonnage Hydraulic Press Machine, its utilization factor is very low. Therefore, Hydraulic Press Machine tends to transmit the working speed and working pressure in stages.

Use of Hydraulic Press Machine

It is widely used in the processing of spare parts in the automotive industry and the shaping, blanking, correction of various products in various industries, as well as the pressing, embossing and forming of shoemaking, handbags, rubber, molds, shafts, and sleeve parts. Bending, embossing, sleeve stretching and other processes, washing machines, motors, automobile motors, air-conditioning motors, micro motors, servo motors, wheel manufacturing, shock absorbers, motorcycles and machinery industries.

Working principle of Hydraulic Press Machine

Hydraulic transmission is a transmission method that uses hydraulic pressure to transmit power and control. The hydraulic device is composed of hydraulic pumps, hydraulic cylinders (hydraulic motors and other actuators), hydraulic control valves and hydraulic auxiliary components

Hydraulic pump: A conversion device that converts mechanical energy into hydraulic energy.

Hydraulic cylinder (hydraulic motor and other actuators): convert hydraulic energy into mechanical energy.
Control valve: control the flow, direction, pressure of hydraulic oil, the working sequence of hydraulic actuators, etc. and protect the hydraulic circuit

Strong and stable C type Hydraulic Press Machine

Strong and stable C-type Hydraulic Press Machine function. To put it simply, it is to control and adjust the flow direction, pressure and flow of the hydraulic medium. So as to control the direction of movement of the actuator, the output force or torque. Movement speed. Action sequence, and limit and adjust the working pressure of the hydraulic system, prevent overload, etc. (such as check valve, reversing valve, relief valve, pressure reducing valve, sequence valve, throttle valve, speed control valve, etc.)

Auxiliary components: 1. Fuel tank: used to store oil and dissipate heat. Separate the effect of air and impurities in the oil 2. Oil pipe and pipe joint 3. Oil filter 4. Pressure gauge 5. Sealing element

The Advantage of Hydraulic Press Machine

The Hydraulic Press Machine directly driven by the pump has the following characteristics

  • 1. The stroke speed of the hydraulic press machine movable beam depends on the liquid supply of the pump, and has nothing to do with the deformation resistance of the forging during the process. If the liquid supply of the pump is constant, the working speed of the Hydraulic Press Machine is a fixed value.
  • 2. The supply pressure and the power consumed by the pump are related to the deformation resistance of the workpiece to be processed. The working deformation resistance is large, and the supply pressure and the consumed power of the pump are also large, and vice versa.
  • 3. The characteristics of the constant stroke speed of the movable beam and the change of the pressure of the pump can be used as a signal to manipulate the distributor to realize the automatic control of the Hydraulic Press Machine.
  • 4. The basic investment is low, the area is small, and the daily maintenance and maintenance are simple. The hydraulic pumps in the direct drive system of the pump are all selected according to the maximum working speed and working pressure of the Hydraulic Press Machine, and the hydraulic pump cannot be obtained when the hydraulic press machine has a small filling stroke, return stroke, auxiliary process and required working pressure. Make full use, especially the large-tonnage Hydraulic Press Machine, its utilization factor is very low. Therefore, Hydraulic Press Machine tends to transmit the working speed and working pressure in stages.

Operating Regulations of Hydraulic Press Machine

  • 1. The operator should be familiar with the general performance and structure of the Hydraulic Press Machine, and overload use is prohibited.
  • 2. Before use, lubricate and add oil according to the regulations, and check whether the high-pressure pump, pressure gauge, various valves, sealing rings, etc. are normal.
  • 3. Before starting up, check whether the Mold is matched, whether the material weight meets the requirements, and whether the weighing tool is accurate.
  • 4. When pressing, the Mold must be placed in the center of the backing plate, and eccentric use is prohibited. Before starting each shift and after pressure test, check whether the Mold is cracked or not.
  • 5. When multiple people operate, a dedicated person should start the machine and coordinate with each other.
  • 6. It is strictly forbidden to put the hand and head between the mold and the indenter.
  • 7. After the work is completed, the pressed products, tools, and molds should be arranged and placed in the designated place.

Maintenance of Hydraulic Press Machine

Operating system

1. The personnel of Hydraulic Press Machine should have corresponding qualifications and must hold a certificate to work. It is strictly forbidden for people who do not understand the machine to open and use Hydraulic Press Machine.
2. The prescribed labor protection products should be worn before the shift.

3. Check the following items before starting up: Whether the photoelectric protection device is reliable, whether the travel switches are sensitive, and whether the fasteners are loose.
4. Remove debris on the work surface and mold, adjust the working pressure, the stroke of the slider, and run the empty car for one to two minutes until everything is normal.
5. The adjustment handle on the machine has been adjusted properly before leaving the factory, and non-debuggers cannot adjust it at will

Maintenance system

  • 1. Carry out lubrication maintenance according to the lubrication requirements of the machine.
  • 2. After the machine tool works for one year, the hydraulic oil should be discharged from the bed oil tank to clean the oil tank, and the filtered hydraulic oil should be refilled. The oil volume should be determined at the 3/4 height of the oil standard.
  • 3. The oil filter net on the oil suction pipe must be cleaned or washed regularly.
  • 5. Regularly check whether the handles, knobs and buttons are damaged.
  • 7. The motor must be kept clean, and the air inlet net cover of the motor must always be well ventilated and not blocked.
  • 8. Lubricate and scrub the machine tool 10 minutes before leaving get off work every day.
  • 9. It is strictly forbidden for non-operators to operate the equipment, and people must leave the machine to stop.

Technical parameter

1. Power: flow × pressure (p × q)

  • a. Flow rate: Nominal tonnage ÷ 250 = Piston area
    Piston area × speed = flow
  • b. The pressure is generally: 250kgfcm2=25mpa
  • c. Power: Nominal tonnage×1000kg/t×9.8n/kgf×250kgf/cm2×speed/m3
    ___________________________________________________
    250kgf/cm2
    Motor power n=power÷efficiency (efficiency is generally taken as 90%),
    9.8 is the acceleration of gravity 1kgf=9.8n

Under normal circumstances, it is calculated according to the above formula, but for special cases, such as hydraulic presses for glass fiber reinforced plastic products, we should compare each
The maximum value is the flow rate and the size of the pressure square. The FRP hydraulic press has a pre-compression action, which requires a higher speed and a slightly lower pressure.
In actual calculations, the power required for this action is the largest. Therefore, in special circumstances, you should pay attention to this matter.
The power of the auxiliary system should be considered. Long-term work should be included. Short-term work such as mobile workbenches can be ignored.

2. The size of the oil pump required

We should calculate the flow rate of the oil pump at each stage.
For example, the 32 series four-column hydraulic press generally uses the ycy series constant power oil pump, and the flow rate when working under the maximum pressure is:
Nominal tonnage ÷ 250kgf/cm2 = piston area
Piston area x speed = flow
Since the ycy series oil pump takes 50%—80% of the rated flow at the maximum pressure, the required oil pump should be:
Flow ÷ set output value
It should also be noted that the nominal flow rate of the pump is the displacement per revolution, the general four-pole motor is 1450 revolutions/min, and the six-pole motor is 960 revolutions/min.
So the displacement per minute is
The nominal displacement of the pump is 1450× (or 960)

3. The model of the valve should be selected according to the flow and pressure passing through the valve

Technical research and development of Hydraulic Press Machine

On April 25, 2014, the 19,500-ton free forging Hydraulic Press Machine and the 300-ton 750-ton hydraulic forging manipulator independently developed by the China National Heavy Machinery Research Institute were successfully tested in Jiangyin, Jiangsu under a heat load, becoming the world’s largest tonnage that has been put into production. The free forging Hydraulic Press Machine and the fully hydraulic forging manipulator with the world’s largest clamping torque are the world’s leading overall installation level. [1] 19,500 tons of free forging Hydraulic Press Machine has a maximum forging capacity of 450 tons. The press can complete free forging processes such as upsetting and drawing length. It has the functions of constant forging and fast forging, and it runs smoothly and without impact. The commissioning of this project has improved the processing capacity and mechanization level of my country’s heavy forging equipment, and has broken the manufacturing bottleneck in related fields.