Solution to oil leakage problem of hydraulic plate bending machine

Views: 5     Author: DURMAPRESS     Publish Time: 2022-08-03      Origin: DURMAPRESS


Solution to oil leakage problem of hydraulic plate bending machine

Hydraulic plate bending machine has been widely used because of the following advantages:

1, the journey is long, at any point in the journey can produce the maximum pressure;

2, with overload protection, will not damage the mold and machine;

3, adjust stroke, pressure, speed is simple and convenient, easy to achieve numerical control;

4, easy to achieve fast approaching, slow bending, can be arbitrarily adjusted to change point;

5, the machine structure layout is flexible, can realize a variety of structures.

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So hydraulic bending machine oil leakage how to do?

Hydraulic bending machine oil leakage is divided into three states: leakage, dripping and oil flow.

Under normal circumstances, static combined with facial position, drop of oil every half hour and dynamic combined with facial position drop of oil every 6 minutes are leakage. Whether it is dynamic binding surface or static binding surface, when dropping a drop of oil every 2 ~ 3min, it is oil drop. More than one drop of oil per 5S in all lubricating parts is considered as flowing oil. The general requirements for leakage treatment of equipment are: there shall be no leakage at the external static joint surface, and slight leakage is allowed at the dynamic joint surface, but it is not allowed to flow to the ground. Some leakage is allowed inside the equipment, but it is not allowed to penetrate into the electrical box and transmission belt, which can be led back to the lubrication box.

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Causes and solutions of oil leakage of bending machine:

1. Oil return is not smooth or there is no oil return channel

Bearing oil return is not smooth, easy to accumulate oil, form a certain pressure, oil leakage; Some oil return hole position design is not reasonable, easy to be blocked by dirt; Some return tank capacity is too small, resulting in oil overflow from the return tank; Some are not designed for recovery. After the use of oil for a period of time, the oil becomes dirty and the bending machine will also have some iron end into the sealing ring when processing parts, resulting in the wear of the sealing ring and oil leakage.

These parts of the sealing ring replacement is very inconvenient, must weigh more than ten tons of front column and slide seat at the same time to be lifted to replace. This is the unreasonable design of the bending machine. The designer should design a set of oil filtration recovery device, which can not only reduce the number of replacement of the sealing ring, but also reduce the waste of hydraulic oil, but also keep the surrounding environment clean.


2. The sealing ring is not suitable for the use conditions

The most commonly used O-shaped rubber seal ring must be selected according to the operating conditions and working state of the equipment. Under oil-lubricated conditions, when oil pressure & LT; 2.9mpa, can choose low hardness sealing ring; When the oil pressure is 2.9 ~ 4.9mpa, the sealing ring with medium hardness should be selected; When the oil pressure is 4.9 ~ 7.8mpa, high hardness sealing ring should be selected. If the seal ring is selected, its allowable pressure is lower than the working oil pressure, it will leak oil.

Selection of compensation mode for CNC bending machine

In the bending process, CNC bending machine on the plate at the same time, the plate will also produce a reaction force on the machine, the reaction force will make the machine deformation, thus affecting the accuracy of the plate. Therefore, in order to improve the bending accuracy, mechanical compensation and hydraulic compensation two kinds of bending machine compensation came into being. Then we in the purchase of CNC bending machine, in addition to considering how many tons should be purchased (bending force bending machine) bending machine, knife edge width, throat depth, column spacing these factors, CNC bending machine compensation mode should also be considered.

Because the two bending machine bending compensation mode of the operator requirements are different, the accuracy of the product is different, to understand what kind of compensation mode should be chosen is very important for buyers.


Hydraulic compensation means that several small cylinders are placed under the table. When the machine is deformed, additional forces are applied through these small cylinders to compensate, so as to reduce the impact of machine deformation on the folded plate. Numerical control hydraulic compensation is the first in the machine's numerical control system, according to the length of the plate, thickness and other data, to set the parameters of the bending machine numerical control system, and then through the machine computer system to calculate the required compensation, the instruction is transmitted to the compensation amplifier. The hydraulic compensation proportional valve receives the signal from the compensation amplifier to control the small cylinder under the table to bulge and reduce the deflection shape variable of the plate.


However, the compensation amount of hydraulic compensation is affected by a variety of factors, such as whether the hydraulic oil leakage, loose joints, etc., will affect each hydraulic compensation amount, resulting in each processing plate is inconsistent, there are differences. The hydraulic compensation system is relatively complex, which may cause oil leakage and loose sealing ring. The advantage of hydraulic compensation is that the machine does not wear out over time, whereas mechanical compensation does.

Compared with mechanical compensation, the machine using hydraulic compensation is simple to operate, and the requirements for workers are not high, so it can fold the workpiece with higher accuracy. In addition, the machine with hydraulic compensation system can ensure the full contact between the upper die and the plate, so as not to let the plate displacement. From the point of view of machine durability and operation simplicity, it is better to choose the hydraulic compensation machine.


Mechanical compensation is the use of oblique wedges to compensate the table. Oblique wedge can be divided into a single oblique wedge and a plurality of oblique wedge. The mechanical compensation composed of multiple groups of slanting wedges has more compensation points than the ordinary hydraulic compensation of 3 compensation points, there is no compensation blind area, the workpiece folded high precision, each processing plate difference is small, suitable for mass production. Compared with hydraulic compensation system, mechanical compensation system is simple, no oil leakage and other conditions, low failure rate and environmental protection. However, mechanical compensation will affect the effect of compensation due to wear and tear of the inclined wedge over time. Mechanical compensation operation requirements are high. If the same workpiece needs to be bent several times, real-time adjustment is required by the worker, even if the worker is experienced enough, it will also produce unpredictable errors. If the workpiece does not need multiple bending, the worker technology is higher, from the workpiece accuracy consideration, can choose mechanical compensation, but in the actual production, the cost of workers with high technology is also high, so comprehensive consideration.

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