Briefly introduce the cleaning of hydraulic valve manufacturing process

In the manufacturing process of hydraulic valves, more options are used to improve the assembly accuracy. That is, for a batch of finished components, such as the valve body and the valve core, a pair of fitting clearances are selected according to the actual size to assemble to ensure good Slip and seal performance. In other words, the same type of hydraulic valve, valve core and valve body with a certain degree of differences in the size of the use of the enterprise, when a certain number of failure of the hydraulic valve, you can remove all valves cleaning, inspection and measurement of various parts, According to the test results, the parts are categorized and the matching methods are recombined according to the following methods.

The auxiliary processing of hydraulic components mainly includes: valve body sand removal, component deburring, heat treatment residue and cleaning and so on.

1. Body cleaning

The majority of domestic hydraulic valve bodies are made of ductile iron, vermicular iron, and gray iron. They are made from resin sand as a styling medium. They are small in size, compact in structure, complicated in shape, and require high precision. The quality of castings is very high. To a large extent, the grade of the hydraulic valve is determined. Since the valve body is made of sand, it is inevitable that there is sticky sand in the casting. Viscous sand is more harmful to the hydraulic system. There are many methods to remove the viscous sand. The domestic commonly used hydraulic pumps include roller cleaning, shot blasting, electrochemical cleaning, and water blasting. Shot blasting is generally used for valve bodies with large oil passages or large oil passages, as well as for body cleaning after rough machining. It not only removes sticky sand, but also removes burrs generated by rust and rough machining. It is a liquid blasting and can also play a role in the surface of the casting. Electrochemical cleaning uses electrochemical reaction between ( SiO 2 ) and molten NaOH to produce sodium metasilicate and water, which can remove the sticky sand in the narrow oil channel relatively cleanly. Therefore, the two methods of shot peening and electrochemical sand removal are used as The method of fine sand removal for valve body castings is widely adopted by various manufacturers. However, these two sand-removing methods also have deficiencies: ( 1) Sand-blasting and sand-removing is applicable to the valve body with a large oil chamber or oil gallery, and it has great limitations for the complicated structure and small valve hole of the oil passage. Effectively removes sticky sand, and it is easy to cause damage to the processed surface, which affects sealability, aesthetics, and product accuracy, and is not conducive to the arrangement of processing procedures; ( 2) Electrochemical sand removal is difficult for some non-recycling chambers to effectively Net sticky sand, and high energy consumption, great damage to the environment, the workers' work intensity is also high, so the sand cleaning of complex parts is still under exploration.

2 、Sliding valve parts deburring and heat treatment residue

Another major problem in the auxiliary process of hydraulic parts is machining burrs and heat treatment residues. The presence of burrs will have an adverse effect on the hydraulic components, such as the clamping of the stem and the blockage of the orifices, especially the grinding of the chrome-plated valve stem in the balance groove. The burrs will enter the stem with the radial fluid dynamics of the oil. In the gap of the valve hole, not only cannot eliminate the effect of the liquid power, but also cause the valve stem to be locked, the operating force is increased or the system pressure is unstable, and the fretting performance and pressure modulation performance are reduced.

During machining, reasonable cutting parameters should be used to control the generation of burrs. For the burrs generated, process removal should be arranged. The methods of deburring are: manual operation, vibratory finishing, belt grinding, copper wire wheel or grinding Optical polishing, stainless steel wire brush polishing, liquid blasting, etc. The choice of method should be based on the actual situation. Relatively speaking, valve body parts use a ball nylon brush or stainless steel wire brush to remove the valve hole burr, that is, before using the fine hinge, use a hand-held electric drill to remove the burrs generated by cutting grooves, rough hinges, and the like. Abrasive belts or copper wheels are ideal for grinding burrs and rust on the outside surface of the valve body. For some coarse grinding flashes, the hacksaw blade is used to scrape off. Other burrs in the cavity can be cleaned by liquid sand blasting. Quenching parts can be removed with special tools or wire brushes. After quenching, oxides, etc. can be removed by vibratory finishing or pickling. Of course, pickling should be based on different materials using different acids and adding appropriate degreasing agents and corrosion inhibition. Agent.

3 , hydraulic valve parts cleaning

The cleaning of hydraulic valve components is a key auxiliary process in the production of hydraulic components. Its quality restricts the reliability and stability of hydraulic valves. Cleaning quality and cleaning methods, the preparation of cleaning fluids, cleaning equipment and personnel responsibility have a great relationship.

Hydraulic valve auxiliary machining is a complex system engineering. It covers a very wide range of fields. Not only must it provide guarantees from equipment, but it must be constantly practiced, summarized, and improved technically. It is also necessary to earnestly grasp and manage the management. Only in this way can the auxiliary processing of hydraulic valves be carried out. The content involved here is only a few superficial experiences and it is hoped that the hydraulic valves will be able to assist the domestic The quality of processing has been improved. Related information recommended: IMD molding machine   Four-column three-plate hydraulic press