A hydraulic cylinder is basically composed of a hydraulic cylinder barrel and a cylinder head, a piston and a hydraulic piston rod, a sealing device, etc. The inner hole of the hydraulic cylinder refers to the hydraulic cylinder barrel, it is the hydraulic cylinder body which mainly bears the pressure. The hydraulic cylinder barrel is usually made of honed tube, which is known as hydraulic cylinder tube, with super smoothy inner surface, inner surface roughness can be max Ra 0.4μm. However, some times there might be scratches on the inner surface of the hydraulic cylinder tube. What are the reasons？and what are the solutions?
Here below are the main reasons and solutions to the reasons.
1. Foreign objects are mixed during assembly to cause scars. Before the general assembly of the hydraulic cylinder, all parts must be fully deburred and cleaned. When installing parts with burrs or dirt, foreign objects are easy to embed due to “uncommon strength” and the weight of the parts. Cylinder wall surface, causing scars.
The scars that occur in the installation parts are due to the large mass, large size, and large inertia of the piston and cylinder head during installation. Even if there is a lifting device to assist in the installation, because the specified fit clearance is small, no matter what, it will be difficult to put in. Therefore, , When the end of the piston or the boss of the cylinder head bumps against the inner surface of the wall, it is easy to cause scars.
The solution to this problem: For small products with a large number of batches, use assembly guide tools during installation; for heavy, thick, large, and medium-sized hydraulic cylinders, only careful operations can be avoided as much as possible.
2. The scars caused by the contact of the measuring instrument are usually used when the inner diameter dial gauge is used to measure the inner diameter of the hydraulic cylinder. The measuring contact is put into the hole wall of the cylinder body while rubbing. The measuring contact is mostly made of high-hardness wear-resistant cemented carbide. . Generally speaking, the slender scratches caused by small depth during measurement are slight and do not affect the running accuracy, but if the size of the measuring rod head is not adjusted properly, the measuring contact is hard to embed, which will cause more serious scars.
The countermeasure to solve this problem is first to measure the length of the adjusted measuring head. In addition, use a piece of paper tape with holes only in the measurement position, and paste it on the inner surface of the cylinder wall of the hydraulic cylinder, that is, the above-mentioned Shape scratches. Slight scratches caused by measurement can generally be wiped off with the reverse side of an old emery cloth.
