Development of electro-hydraulic hammer at home and abroad

The first generation of electro-hydraulic hammer is single-acting, that is, hydraulic lifting hammer and falling hammer do work. The hammer head of this kind of electro-hydraulic hammer has large mass, low speed and low energy, which greatly limits the scope and production efficiency of forging forgings.

The second generation electro-hydraulic hammer is gas-liquid double-acting type, that is, the lifting hammer is hydraulic, and the striking energy combines gravity work and gas expansion work. Compared with the first generation, this electro-hydraulic hammer has higher hammer speed, greater impact energy, impact frequency, production efficiency and forging specifications under the same drop hammer conditions.

The third generation electro-hydraulic hammer is a double hydraulic action type, also known as full hydraulic electro-hydraulic hammer, that is, the lifting hammer and the striking hammer are directly acted on the moving parts of the hammer head by hydraulic pressure, rather than directly acted on the piston of the hammer rod by gas.

Full-hydraulic electro-hydraulic hammer is regarded as the most advanced technology by scholars at home and abroad because of its fast response and high reliability, and has been paid attention to and developed by many countries.

(1) The lifting and striking of the hammer are powered by hydraulic pressure. That is, the upper and lower cavities of the hammer piston are driven by hydraulic oil, and its advantages are as follows: a, the sealing condition is better than that of gas, and there is no problem of cross connection between oil and gas. The sealing life of hammer piston is long, which can generally reach more than two years. B, two gas poles, four copper sleeves, two jackets, two flanges and related seals of three-pole type are cancelled, which simplifies the structure, completely eliminates the problem of "gas pole leakage", reduces nitrogen consumption, improves the normal operation rate of equipment, and greatly reduces the failure link and maintenance workload.

(2) Pump-accumulator combined transmission mode is adopted. Both the lifting and striking of the hammer are supplied by the accumulator and the oil pump, which not only saves the installed capacity, but also makes the whole system respond quickly and have high sensitivity. In addition, when lifting the hammer, there is no gas pressure in the upper cavity of the piston of the hammer rod, so the hammer lifting is fast and the betting frequency is high. For the free forging hammer, it is very convenient to work and turn over; For the die forging hammer, the boring time is reduced, the service life of the die is improved, and some forgings forged at both ends can be formed at one time, saving heating energy, reducing material loss, improving production efficiency and increasing economic benefits.

(3) The hydraulic system adopts a large-diameter combined cone valve to control the lifting, striking, stopping and slow descending of the hammer, and the large-diameter combined cone valve is controlled by a small slide valve manually operated by the operating system as a pilot valve. Characterized in that:

A. The pilot valve has small mass and inertia, and the force of the control handle is very light.

B, hydraulic oil temperature, viscosity, cleanliness is not high, can work continuously for a long time, without replacing the hydraulic oil.

The viscosity of oil is not too strict. Generally, 20#, 30# and 40# machine oils can be used, and even these oils can work normally when mixed. In short, as long as there are no hard objects such as welding slag and iron filings in the oil, the oil pressure system can work normally. Because the system adopts large-caliber combined cone valve, the valve port has good sealing performance, less leakage, less energy loss, less oil heat and long service life. After an adjustment, it can be maintained all the year round.

(4) The closed air chamber of the upper cavity of the piston of the hammer rod is cancelled, so that the oil can hit the hammer, and the oil in the lower cavity of the piston is discharged to the upper cavity. The piston lubrication condition is improved, the lubrication effect is better, the oil is changed constantly, the oil temperature is low, the seal is not easy to age, and the service life is long. In addition, when the hydraulic hammer is lifted, the oil in the upper chamber of the piston is discharged back to the oil tank. In this way, the oil return speed is low, the flow resistance is small, and the oil tank or oil return pipe will not expand.

(5) The diameter of the hammer rod is thicker than that of the common electro-hydraulic hammer, and there is a multi-degree-of-freedom hammer head connecting device between the hammer rod and the hammer head, so that the hammer rod, the seal and the guide sleeve are not affected by the torque generated by the eccentric impact of the forging. The service life of the hammer rod system is improved, and the general free forging service life is more than two years.

(6) Compared with the hammer piston, the linear velocity of the accumulator piston is smaller, which is only1/6-1/9 of the hammer piston; The stroke is short, only about 1/3 of the hammer rod, and there is no eccentric load. The stress on the piston is basically balanced up and down, the pressure difference is extremely small, and the reliability of the accumulator is higher.

(7) Selecting a high-pressure and large-flow piston pump (P=3 1.5MPa, Q=400L/min) and using it under low pressure (the general working pressure is below 10MPa) can make the pump have high volumetric efficiency, low vibration, low noise, firmness and reliability, less leakage and long service life.

(8) When the hydraulic hammer is in a non-working state, the hydraulic system can automatically unload to reduce the oil temperature and heat.

(9) According to the user's site conditions and use requirements, the power head and hammer body can be integrated or separated, and the user can choose:

(10) According to the difference of free forging and die forging equipment, the operating mechanism can be operated manually or by foot.