1. Method of observation

The valve rocker arm is generally installed in the rocker arm seat with the rocker arm shaft positioning (below), which is an important connection part for the camshaft and the valve. Among them, the back arm of the rocker arm is a cylindrical surface (usually R30), which is the part of the contact with the CAM, and is quenched and chrome plated. The genuine valve rocker arm is well made, the appearance has the marks of shot blasting process, looks very smooth, and feels very smooth in the hand. When selecting, it is necessary to carefully observe whether the body of the rocker arm has burrs, shrinkage holes, porosity, pores, cracks and slag inclusion and other defects.

General maintenance personnel can not measure the relevant dimensions of the rocker arm, it is recommended to put the new rocker arm and the original rocker arm together with the rocker arm shaft, so that the back arm cylinder of the two rocker arms (that is, the R30 arc surface) against the flat or glass plate plane, and then carefully observe and compare the Angle of the front end of the two rocker arms (that is, the end of the installation valve gap adjustment screw) is consistent (below), if the Angle is not consistent, It will lead to abnormal valve lift and running noise. The material and hardness of the valve rocker arm can be compared and identified by reference to the percussion method, spark identification method and observation method in the camshaft parts.

2. Look at the packaging

The product packaging produced by regular manufacturers is implemented in accordance with relevant national standards and is more standardized. Whether it is carton packaging or soft plastic packaging, it contains: product name, product registered trademark, product standard number, product license, product bar code, implementation standards, full name of product manufacturing company, detailed address, fixed telephone, free service hotline, manufacturing base, company website, email and so on. The font on the packaging box or bag is regular and clear, and the color is bright. The metal parts are wrapped in multi-layer rust-proof paper, and the non-metal parts packaging box or packaging bag has a porous setting, which is easy to prevent mold and gas.

The product packaging produced by informal manufacturers is relatively rough, generally no product standard number, product registered trademarks, company websites, product licenses, product bar codes, implementation standards and fixed telephones, most packaging has no fixed telephones, only mobile phone numbers, and the font printing on the packaging box or bag is fuzzy and dim. Metal parts do not have multi-layer rust-proof paper wrapping, non-metal parts packaging boxes or packaging bags for closed Settings, can not breathe, easy to mold.

The identification method described above is simple and practical, not absolutely reliable. Therefore, only the purchase of the valve rocker arm produced by a regular manufacturer can ensure the product quality of the accessories. The valve rocker arm produced by regular manufacturers adopts high-quality low-carbon alloy steel 20CrMo precision forging, which has high strength and good thermal performance. The valve rocker arm is shot peening, carburized, quenched, polished and chromed to enhance the fatigue and wear resistance of the parts, which can meet the working requirements of the strengthened engine, greatly extend the service life, and meet the timely opening and closing of the valve of the engine valve mechanism and various technical requirements.

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