Large-aperture machining method for multi-gear straight holes and conical surface holes in diesel engine cylinder cover

Abstract

The invention provides a large-aperture machining method for multi-gear straight holes and conical surface holes in a diesel engine cylinder cover. The large-aperture machining method comprises the following specific steps that the diesel engine cylinder cover with the large aperture needing to be machined is fixed to a machining center through a multi-point positioning tool; different straight hole rough machining tools and conical surface rough machining tools are used for conducting allowance removing machining on multi-gear straight holes and conical surface holes in the large hole diameter; and a combined precise boring tool is used for performing finish machining on large-aperture multi-gear straight holes and conical surface holes in the diesel engine cylinder cover at the same time. The requirement for one-tool machining of large-aperture multi-gear straight holes, conical surface holes and datum holes is met, unification of the design datum and the machining datum of parts is achieved, datum conversion and error accumulation of a rotary workbench are avoided, the workpiece machining precision is improved, and the product quality is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of hole system processing, and in particular relates to a large-diameter processing method with multi-level straight holes and tapered surface holes on a cylinder head of a diesel engine. Background technique [0002] The cylinder head is a typical, complex, box-like part that integrates a large number of holes. The holes on the head are different in structure, size, precision, etc. according to their respective uses. The processing quality of the taper surface of the cylinder head valve seat hole directly affects the sealing performance of the diesel engine's air supply system, so the processing here is particularly important in the processing of the entire cylinder head. [0003] The main requirements for the valve seat hole of a certain type of marine diesel engine cylinder head are as follows: figure 2 Shown: the first gear large diameter straight hole 1-1 of φ148H8, The second gear middle diameter st...

AI Technical Summary

Problems solved by technology

The disadvantages of this kind of processing are: 1) the rotation accuracy error of the table is superimposed in the processing result of the tapered surface hole - the 180° rotation error of the table; Conversion error; 3) The actual clamping state of the cylinder head during processing (whether the cylinder head is tilted forward or backward) directly affects the beating result of the cone surface relative to the reference hole at the far end

The first two out-of-tolerance situations can be corrected by adding manual scraping and grinding. The removal amount of each scraping and grinding is very small, so it is necessary to use manual scraping to correct the fit of the cone surface (and the beating of the cone surface) and improve the surface roughness. The workload is very large, and the scraping and grinding requires high operational skills of the workers. The results of scraping and grinding by different people will be different. If there is a little carelessness, the entire cylinder head will be scrapped; when the third situation occurs, the cone surface When the depth of 19±0.2 is close to the lower difference or is already smaller than the lower difference, it cannot be trimmed by scraping the cone surface, and the entire cylinder head will be scrapped directly

Due to the uncertainty of this processing method, it will cause major problems in processing quality at any time, causing inestimable economic losses to the company.

[0007] With the development of the enterprise, the annual output of this type of cylinder head is increasing year by year. The original processing method can no longer meet the requirements of mass production. Therefore, it is necessary to abandon the original low-efficiency processing method and re-design a new high-efficiency processing plan.

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