Design of case manufacturing technology fan shaft

DESIGN OF CASE MANUFACTURING TECHNOLOGY FAN SHAFT

Yusupov Sardorbek Marufovich-PhD,

Fergana Polytechnic Institute,

Head of the “Department of Mechanical Engineering and Automation”
Ismoilov Otabek

Fergana Polytechnic Institute,

Bachelor’s degree student of 18-18 group

Annotation: This article examines a generalized assessment of the manufacturability of the product design and the routing technological process of the fan shaft housing with a visual sketch of the product.

The main goal of mechanical engineering at present is the introduction of modern technologies that increase the quality and reduce the cost of the product, contribute to the creation of effective, competitive technology, while not requiring large capital investments. The main problem in the manufacture of enclosures is the long production period. In this regard, different machines and devices are used, but in our article we have reduced the time spent by choosing a more modern CNC machine.

The body is the basic part, in which individual assembly units and parts are mounted, connected to each other with the required accuracy of relative position. It ensures the consistency of the accuracy of the relative position of parts, both in a static state and during the operation of the pump, as well as smooth operation. The pump casing is a basic casing part with complex spatially located inner and outer surfaces. The most critical of them are machined to ensure the accuracy and roughness of the surfaces indicated in the drawing. The body is made of steel grade: 15L, which is most widely used in industry due to the possibility of its successful use. For steel grade: 15L, requirements are imposed on high plasticity and operating at temperatures from -40 to 450 ° С; also requirements for high surface hardness and low core strength are imposed on it.

Blanks for body products are mainly made by investment casting, but there are exceptions, more complex body products are made by welding. In order to choose the right way to obtain a workpiece, you need to study the further mechanical processing process so that the total cost is minimal.

The analysis of manufacturability is one of the most important stages in the development of a technological process and is carried out in order to identify the possibilities of using the most progressive and effective methods, means and technological processes for manufacturing a product with specified quality indicators and minimal costs.

The lower the labor intensity and cost of manufacturing a product, the more technologically advanced it is. Thus, the main criteria for assessing the manufacturability of a structure are labor intensity and manufacturing cost.

The main factors that determine the requirements for the manufacturability of the product design are:

- the type of product that determines the design technological features and determines the basic requirements;

- the volume of output and the type of production, which determine the degree of technological equipment, mechanization and automation of technological processes.

Further in the article, an assessment of the manufacturability of the structure, as well as the route technological process of manufacturing and a sketch with cutting tools, will be presented in tabular form.

At the design stage of the machining process, it should be established whether the design bases that are specified in the working drawing can be used as technological bases from which the cutting tool will be tuned in the coordinates of the machine. If the bases do not match, then you need to select other surfaces and establish dimensional relationships for them. In this case, the accuracy of the design dimensions must be maintained during processing. If the specified accuracy of the design dimensions is not met, the workpiece basing scheme should be changed.

For surfaces that are processed in several technological transitions on pre-configured equipment, it is required to determine intermediate technological dimensions, which are called operational.

To perform such tasks and further design the technological process, a linear dimensional analysis is carried out, as a result of which the technological dimensions are determined at each transition.

Dimensional analysis of the X-axis.

The diagram of the graphical representation of the dimensional analysis of the machining of the body part for the X axis is shown in Figure 1. In the diagram, the design dimensions are indicated by capital letters Ki, technological dimensions - by the letters Li, allowances - Zi, spatial deviations Si.

According to the dimensional scheme, the original and derived graphs are built. On the original graph on the surface of the part, design dimensions are applied, as well as allowances and spatial deviations of the main holes to the intermediate surfaces. On the derived graph on the surface of the part and the workpiece, the technological dimensions and dimensions of the original workpiece are applied, while the arc should go out of the base surface and point to the surface to be machined. The resulting graphs are shown in Figures 2 and 3.

Figure 1 - Dimensional diagram of the technical process relative to the X-axis.

Figure 2 - Initial graph of the X-axis.

Figure 3 - Derived graph of the X-axis.

On the basis of the initial and derived graphs, canonical equations are compiled for each axis, and then they are transformed into the equations of the closing link.

Table 1 shows the equations describing the compiled dimensional chains for the X-axis. In the equations, the design dimensions and spatial deviations of the axes of the main holes of the workpiece are considered as closing links. To write the canonical equation, it is necessary to determine the vertices on the initial graph that connects the closing link, and then move through the derived graph from the vertex with a lower number to the vertex with a larger number. The link is written in equations with a plus sign, in the case of an increase in the vertex in the direction of the traversal, or with a minus sign, in the case of a decrease in the vertex.

T
able 1 - Canonical equations of dimensional chains (X-axis).

Based on the plans for the surface treatment of the part, a starting technological process was developed and illustrations of the processing route were made. Suitable equipment and technological equipment have been selected. Allowances and nominal diametrical dimensions with tolerances for each technological transition have been determined.