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• Time:2021-02-27
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1. Poor manufacturing quality

(1) The inner and outer layers of the high-pressure hose wall are made of oil-resistant rubber, and the middle is (2 to 4 layers) cross braided steel wire or wound steel wire. Poor quality hoses will appear: uneven wall thickness of the hose; too tight or too loose steel wire braiding or too few steel wire layers; large deformation (elongation, shortening or bending deformation) of the hose after pressure; outer rubber Poor air-tightness leads to steel wire corrosion; poor sealing of the inner layer glue makes the high-pressure oil easily enter the steel wire layer; insufficient adhesion between the glue layer and the steel wire layer. The above conditions will reduce the bearing capacity of the hose, and eventually burst at the weak point of the tube wall.

(2) Improper selection of the crimping amount and crimping speed when assembling the hose and the joint, or the unreasonable selection of the structure, material, and size of the joint can cause the hose and the joint to be over-tightened or too loose, causing early damage to the joint. When assembling, if the crimping amount is too small, that is, when the pressure between the joint and the hose is too loose, the hose may come out of the joint at the beginning of use under the action of oil pressure; if the crimping amount is too large, the joint and the hose will be compressed. Too tight, it is easy to cause partial damage to the inner layer of the hose, causing cracks. High-pressure oil will directly enter the steel wire layer from the rupture, and then rush along the gap between the steel wires to the end of the jacket and spray out, or it will rush along the steel wire layer to a certain place and accumulate. , Make the outer layer of glue bulge or even break. When assembling the hose and the joint, if the crimping speed is too fast, it is easy to cause damage to the inner rubber and breakage of the steel wire layer, which will cause the hose to be damaged prematurely during use. In addition, unreasonable joint design and poor processing quality can also cause damage to the inner rubber; if the joint material is selected incorrectly, it is easy to deform during the crimping process, which will affect the crimping quality and shorten the life of the hose.

2. Improper use On the premise that the quality is guaranteed, if used improperly, the service life of the hose will be greatly shortened. In actual work, most of the damage to the high-pressure hose is caused by improper use.

(1) Subject to frequent and severe pressure shocks. The bursting of the high-pressure hose is generally not caused by too much static pressure, but is related to the severity and number of pressure shocks. When construction machinery is in operation, sudden increase or decrease of oil pressure in the oil pipe will occur repeatedly, which constitutes frequent pressure shocks on the oil pipe, resulting in increased damage to the oil seal of each part, blistering and rupture of the rubber pipe, and loosening and leakage of pipe joints. Leakage phenomenon. Therefore, during operation, the valve stem must not be pulled too hard, and must be gentle.

(2) The use temperature of the oil is too high. When construction machinery is working, the hydraulic system heats up the oil due to power loss, and the influence of outside air temperature (especially in summer) can cause the oil temperature to rise sharply. The higher the temperature of the oil is, the more easily the bananas will age, the elasticity will deteriorate, the strength and sealing performance will decrease, and the hose will burst quickly. Therefore, during operation, when the hydraulic system temperature rises too high or too fast, the cause should be found out in time and eliminated; during summer operation, especially continuous operation, necessary cooling measures should be taken.

(3) The hose selection and installation are unreasonable. When replacing the high-pressure hose, the length of the selected hose, the number of steel wires, the shape and size of the joint should be reasonable, and the degree of bending of the hose should be minimized; when tightening the joint nut, do not cause the hose to be twisted, excessive bending and Distortion will greatly reduce the service life of the hose; protective measures should be taken for some parts prone to friction to prevent the hose from bursting due to wear.