Hydraulic valve manufacturing process, in order to improve assembly accuracy and more use of matching methods, that is, a group of finished parts, such as the valve body and the valve core, according to the actual size of the gap with the most appropriate choice of a pair of assembly, to ensure good Spool sliding and sealing performance. In other words, the same type of hydraulic valve, spool and valve body with the size of a certain difference For the use of enterprises, when a larger number of hydraulic valve failure, you can disassemble and clean all valves, inspection and measurement of various parts, Sort the parts according to the test results and recombine them according to the following methods. Hydraulic auxiliary processing mainly include: body cleaning, deburring parts, to heat treatment residue and cleaning and so on. 1, the body of the class of sand-made hydraulic valve The vast majority of valve body to ductile iron, vermicular iron, gray iron as the material to resin sand as the molding medium Fansha made by casting, with small size, compact structure, complex shape and accuracy Requires higher characteristics, the quality of the casting largely determines the level of the hydraulic valve. Because of the sand body for the valve body shape of the material, it is inevitable in the casting of sticky sand there. Sticky sand is more dangerous to hydraulic systems. There are many ways to remove sticky sand. The hydraulic pumps commonly used in the country are cylinder sand cleaning, shot peening, electrochemical sand cleaning and sand blasting. Shot peening sand generally used for open or large oil channel body and rough after the body of the valve cleaning sand, it can not only remove the sticky sand, but also remove the rust and rough machining burr, especially Liquid sandblasting, but also play the role of decorative surface castings. Electrochemical sand cleaning is the use of (SiO2) and molten NaOH starting electrochemical reaction of sodium metasilicate and water, can clean the narrow small oil in the sticky sand, so the two methods shot peening and electrochemical sand as the Valve body to fine sand method, widely used by various manufacturers. However, these two methods have some shortcomings: (1) sand blasting is suitable for larger oil chambers or open oil bodies, which have great limitations on complicated structures and small oil passage holes. Effective removal of sticky sand, and the processed surface is more likely to cause damage, thus affecting the sealing, aesthetics and product accuracy, and is not conducive to the processing arrangements; ⑵ electrochemical clear sand for some acyclic cavity is difficult to effectively go Net sticky sand, and high energy consumption, great damage to the environment, the workers operating intensity is high, so the complex pieces of sand are still under exploration. 2, slide valve parts to deburring and heat treatment residue hydraulic parts auxiliary process Another big problem is to machining burrs, heat treatment residues. The presence of burrs will have an adverse effect on the hydraulic parts, such as stem clamping, clogging of the damping orifice, in particular chrome-plated stem balance groove grinding, glitches with the radial hydraulic fluid into the valve stem and Valve hole clearance, not only can not eliminate the role of hydrodynamic, but will lead to the stem clamping, increased operating pressure or system pressure instability, fretting and pressure modulation performance decline. Machining should use reasonable cutting parameters to control the generation of burrs, burrs generated should be arranged to remove the process, deburring methods are: manual method, vibration light decoration, belt grinding method, copper wheel or grinding Polishing machine polishing method, stainless steel wire brush polishing method, such as liquid sandblasting. The choice of method should depend on the actual situation. Relatively speaking, the valve body parts use a ball nylon brush or stainless steel wire brush to remove the valve hole burr, that is, before the fine hinge with a hand drill to clamp the brush to remove the cutting groove, the rough hinge sequence generated by the burr. Belt or copper wheel on the outer surface of the valve body to remove burrs and rust is more ideal for some of the thicker grinding flash should be first cut with a hacksaw blade, the inner cavity of other burrs liquid blasting method can be used to clean, for Quenching parts can be used special tools or wire brush to remove the oxide after quenching and other general vibration or acid wash can be removed, of course, pickling should be based on different materials with different acid and add appropriate degreasing agent and corrosion inhibition Agent. 3, hydraulic valve parts cleaning Hydraulic valve cleaning parts in hydraulic parts production is a key ancillary processes, its quality restricts the reliability and stability of the hydraulic valve. Cleaning quality and cleaning methods, cleaning fluid preparation, cleaning equipment and staff responsibility has a great relationship. Hydraulic valve auxiliary processing is a complex system engineering, it involves a very wide range, not only from the equipment to provide protection, technical continuous practice, summary, improvement. But also from the management seriously to grasp, to control, the only way to hydraulic valve auxiliary processing engage in, the content involved here is only some superficial experience, hoping to be able to domestic hydraulic valve assist The quality of processing has some benefits.
