Repair method and necessity of broken hammer piston rod
Time：2016-08-05 14:57:58 Form：admin
The inside of the hydraulic breaker is a confined space. Except for air and hydraulic oil, if it enters impurities or other hard objects, it may cause the hammer of the breaker to be injured. If the strain is severe, the whole breaker may be scrapped. Therefore, the majority of the hammer is recommended. For hammer users, regular maintenance of the breaker is critical to the life of the breaker. When replacing the breaker seal for three months or 600 hours, check the piston and the inside of the cylinder. Of course, if it is a mild strain, you can use the following. Method fix.
After the piston rod of the hydraulic cylinder is pulled, the internal space of the breaker will be leaked. If it is not treated in time, it will affect the normal use, and the hydraulic cylinder will not work. Our repair method is to repair the lighter stretch marks by local grinding and polishing; for the heavy pull marks, it is repaired by welding and manual grinding.
The formation of the pull marks: After disassembling the crane, it was found that a piston rod of the luffing cylinder was severely strained, and the pull marks were arranged side by side. The main cause of the strain on the broken hammer is: after the brittle hammer oil seal is brittle and falling off, it not only loses its dustproof effect, but also accumulates a lot of dust and magazines at the place, so that the piston rod is directly ground with impurities, resulting in hard grinding. The piston rod was pulled, and the scratches then scratched the rubber seal assembly of the cylinder port, causing serious leakage of the hydraulic cylinder.
Repair requirements: the filler and the base metal must be combined firmly and smoothly; the seasoning must be durable and easy to process by hand; manual machining must ensure that the diameter of the piston rod is less than 0.06mm. After analysis, it was decided that the filler used was J422 electrode.
Because the acid electrode is not sensitive to rust, oil and moisture, it is not easy to produce hydrogenation holes; the process is good and easy to operate; the weld is beautifully formed; the material hardness is moderate, easy to process by hand; the arc is stable, the penetration is large, and the base metal The combination is firm.
Repair process
Clean the parts to be welded first, then use the wet mud to keep the traces around.
The electrode with a diameter of 2.5mm is used to adjust the current of the welding machine to 120A, and the welding is carried out smoothly by the straight line method.
After all the welding is completed, the mud and slag are removed, and the rough boring is performed along the circumference of the piston rod to maintain a machining allowance of 0.1-0.2 mm.
A cylinder with an outer diameter of 185 mm, an inner diameter of 125 mm and a length of 150 mm is sawed along the axis (the outer diameter of the piston rod is 125 mm), and is sawed along the axis, one for the rough mold and the other for the fine mold.
A thin red ink is applied to the inner wall of the rough mold, and then the rough mold is abutted on the piston rod to be repaired and reciprocated a few times along the axis, and then the heavier red mark on the piston rod is removed by a fine boring. This is repeated repairs, leaving a machining allowance of 0.04-0.07mm.
The piston rod is then ground to a specified size with 320 mesh sand slag kerosene and a precision mold.
Finally, hand-polished with kerosene on the back of the sand cloth. After measurement, the maximum error is only 0.03mm.
After the repair of the excavator breaker, after a year and a half of use, the variable amplitude hydraulic cylinder has never experienced any leakage, and the piston rod is smooth and has no rust.
Please read the above carefully to understand the importance of maintaining the breaker hammer and what can be repaired and what needs to be replaced in order to make better profits and bring benefits to the company's development.
