Multifunctional chassis tooling for measuring piston profile with roundness meter and its measuring method

Abstract

The invention relates to a multifunctional chassis fixture for a roundness measuring instrument to measure the molded lines of a piston. The multifunctional chassis fixture is provided with a lower positioning chassis and an upper rotary indexing positioning disk which are provided with an axial locking mechanism, wherein the lower positioning chassis and the upper rotary indexing positioning diskhave high roundness, and are coaxial and concentric with each other; positioning pin holes are formed in the edges of the upper disk and the lower disk; the area of a roundness measuring instrument base is increased, and a measuring diameter is increased; the lower disk and upper disk are indexed respectively through each positioning pin hole with an indexing accuracy of 55 divisions to 65 divisions, and the lower disk and upper disk perform indexed rotation; 1-degree indexing scribed lines are fabricated on the lower disk; the positioning pin holes and the roundness measuring instrument arematched with each other so as to perform indexed rotation with angle differences, are positioned through positioning pins and locked through the locking mechanism; and the long axis zero position of the piston skirt of the piston and the zero position of the roundness measuring instrument are corrected and overlapped with each other. The multifunctional chassis fixture has the advantages of convenient operation, simple production, low production cost, high detection precision, high measurement efficiency, high economical efficiency and high practicality, and can meet the universality measurement requirements of different types of pistons, and therefore, the popularization and use of the multifunctional chassis fixture can be facilitated.

Description

technical field [0001] The invention belongs to the technical field of mechanical tooling for physically measuring the contour or curvature of a piston of a special-shaped part, and in particular relates to a multifunctional chassis tooling for measuring the profile of a piston with a roundness meter and a measuring method thereof. Background technique [0002] The design of the outer surface of the piston skirt of a diesel engine is an important factor to ensure high power, low fuel consumption and smooth operation of the diesel engine. No matter from the design and development of the piston, or the digestion and absorption of foreign piston samples, precise and advanced measurement methods are required to provide accurate data of the piston profile. Among them, the surface profile of the piston skirt is not a general circular or elliptical shape, but a changing piston skirt-to-ellipse outer circle profile calculated according to different models and power, such as convex t...

AI Technical Summary

Problems solved by technology

However, due to the influence of the detection of the piston profile as a special-shaped part, the traditional three-jaw centering plate of the roundness instrument cannot be used; and in order to realize the detection of the piston skirt profile, the error correction between the zero position of the long axis of the piston skirt and the zero position of the roundness instrument The control is within 3°. Under the existing technology, the disadvantages of the tooling used to detect the piston skirt line with the roundness meter are: (1) The effective diameter of the roundness meter worktable is between 150mm-300mm, which is affected by the roundness meter The rotary chassis itself Due to the diameter limit, only smaller pistons can be measured, which has great limitations; (2) Usually, to measure the piston profile, the dumbbell pin must be made correspondingly, and the dumbbell pin must be pressed on the piston pin hole of the short axis of the piston, and the short axis is measured by a roundness meter. Axis positioning; Although this positioning has high precision, it is inefficient; (3) Each type of piston must have a corresponding dumbbell pin, the detection cost is high and the production cost is high, and the versatility of the tooling is poor; , although the efficiency is high, but the accuracy is low and the measurement error is large

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