Bearing housing workpiece drawing

Introduction

Mechanical engineering has a leading role among other sectors of the national economy, since the main production processes are carried out by machines. Therefore, the technical level of all sectors of the national economy is largely determined by the level of development of engineering.

Based on the development of mechanical engineering, complex mechanization and automation of production processes are carried out in industry, construction, agriculture, and transport.

The production efficiency, its technical progress, quality of products in many respects depend on the advancing development of production of the new equipment, machines, machines and devices, on the global introduction of methods of the technical and economic analysis providing the solution of technical questions and cost efficiency of technological and design developments.

1. Analytical part

The processing of holes, which are subject to high requirements for accuracy in size, shape and arrangement, remains one of the pressing problems of modern mechanical engineering. A significant part of the total labor input in the manufacture of parts on CNC milling and drilling machines is the processing of precise holes.

In the manufacture of body parts, there are necessarily operations of machining precise holes, without which it is impossible to imagine the manufacture of body and a number of other products. It should be noted that 4070% of the total labour input of the CNC multipurpose machine is the machining of the main holes serving as base surfaces for mounting shafts, axles, bearings, etc.

In the manufacture of mold parts and dies, the labor intensity of machining holes as part of the process operation performed on a multi-purpose CNC machine is more than 40%.

The high labor intensity of machining holes on CNC machines is not so much due to the large number of holes in the machined parts as to the difficulty in providing high requirements for the accuracy parameters of size, shape and arrangement. The difficulty of ensuring the accuracy of the machining of the holes in the NC milling bore group is mainly the absence of the guide elements of the cutting tool process system.

To ensure high accuracy parameters, various processing schemes for processing holes are used. Usually up to seven transitions are assigned by various tools. In addition, in the field of precision hole processing, new and existing methods are constantly being developed to ensure the accuracy of their dimensions, shape and arrangement. In this regard, the optimal selection of the process, tool and their characteristics becomes increasingly important at the design stage of precision hole processing, which extremely complicates the design process itself and quite conditions the high production preparation time on CNC machines.

2.2 Analysis of input data for technological process development

The part is made of cast grey cast iron SCH 18-36. The configuration of the outer surfaces does not cause significant manufacturing difficulties. Nevertheless, molding must be carried out using rods that form internal cavities. These cavities shall be made within the specified deviations and concentric with accuracy up to 0.4 mm.

The most accurate dimensions are the landing holes: Ø130N10, Ø80N9, Ø60N10. Their accuracy is due to further collection.

When machining, tool access and chip removal are not difficult. All holes in the part are located at right angles to the plane of entry and exit and their mechanical processing does not cause difficulties. However, four holes Ø13 have a fairly high roughness class, so after drilling and boring operations it is necessary to introduce countersink.

Bearing Housing Fabrication Specification:

1. Cast defects are not allowed on machined surfaces - since the treated surface must be of high quality and clean;

2. Unspecified casting radii R5 - made on non-machined surfaces;

3. Moulding slopes 1 - 20 - provide easy removal of the workpiece from the mold;

4. The remaining T.T. according to GOST 30301.3 - 2002: H14, h14, IT14/2 - these pre-launches are placed on dimensions that do not affect the assembly.

According to the analysis, the part can be considered technological.

2.9 Calculation of cutting modes

Calculation of cutting modes is carried out simultaneously with filling of operational and roadmaps of technological process. Combining these works eliminates the need to duplicate the same information in different documents, since the operating cards should record data on the equipment, processing method, characteristic of the processed part, etc., which are used for calculations of cutting modes and should not be re-recorded as initial data for the calculation.