Casting Cover

Contents

Introduction

1 Development of mold elements

1.1 General analysis of workability of articles

1.2 Selection of casting method

1.3 Determination of machining allowances

1.4 Selection of runner system inlet and runner system structure

1.5 Runner System Calculation

1.6 Selection of optimal shape and dimensions of supports

1.7 Economic justification of forming method

List of sources used

Paper

The course project consists of a calculation and explanatory note and a graphic part. The explanatory note contains 15 pages, 3 tables and 1 drawing. The graphics part contains 3 drawings .

Keywords: shape, slag, casting, runner system, filling time, riser, feeder, slag catcher, moulding mixture, chopping, etc.

In this work, the technology for manufacturing the "Cover" casting has been developed. The development of the technology includes: the choice of the method of manufacturing the casting, the rational position of the casting in the mold, the development of the casting model, the selection of supports, the calculation of the sprue system.

Introduction

The casting method is relatively simple and cheap. By casting, you can get almost any of the complexity of the configuration of the product, including machine parts weighing from several grams to hundreds of tons, from several millimeters to tens of meters in size, which is often impossible by other methods of producing blanks. In addition, casting is a very flexible production, allowing you to quickly change the range of products produced on the same technological equipment, to obtain single and even unique products with a relatively low cost.

Any machine or product consists of separate parts made of various materials and made by certain methods (casting, welding, forging, stamping, machining, etc.). Among the methods of manufacturing parts, casting occupies a leading place, somewhat inferior in recent years to welding. The share of cast parts in the design of modern machines varies widely from 25 to 80%, averaging about 40%.

Cast parts are characterized by a very wide variety in weight and size. They are made from various alloys, materials, including plastics. Casting methods can be used in a wide variety of ways depending on the requirements for the quality of the part, their serial production.

The main method of making castings is casting in sand-clay molds (PGF), in which up to 78% of the total number of cast parts are obtained. In addition to PGF casting, there are other progressive casting methods, such as coquille casting, shell casting, smelt casting, centrifugal casting, high and low pressure casting, gasified casting, and other types of casting. These casting processes differ from PGF casting not only in their high economic cost but also in their high accuracy and low surface roughness.

Developing Mold Elements

1.1 General analysis of workability of articles

The detail works both at cyclic, and at constant loads, in the conditions of high wear and belongs to castings of responsible appointment. The cover experiences mainly impact (radial) loads. The workability of the part meets the main operational properties. Aluminum alloy AL7 was chosen as the casting material.

There are no pronounced thermal units in the part, and the wall thickness is approximately the same in all its parts, which satisfies the conditions of pouring and feeding, and the principle of solidification directionality is also observed.

1.6 Selection of optimal shape and dimensions of supports

When selecting the shape and dimensions of the supports, consider the following :

- they shall ensure minimum consumption of the moulding mixture;

- the size of the support shall prevent the metal from breaking through the walls.

Note that one cast will be located in one block, based on this, we will determine the size of the supports for production. In order to determine the dimensions of the supports, it is first necessary to determine the minimum thickness of the layer of the molding mixture:

- From the top of the model to the top of the support - 120 mm;

- From the bottom of the model to the bottom of the support - 60 mm;

- From model to wall 115 mm;

- Between model and slag trap - 60 mm;

- Between the riser and the wall of the support - 70 mm.

Consequently, the minimum dimensions of the supports shall be as follows:

Height H = 420 mm;

Length L = 650 mm;

Width B = 650 mm.

According to GOST 213385, the dimensions of the supports are as follows:

Height H = 450 mm;

Length L = 710 mm;

Width B = 710 mm.

1.7 Economic justification of forming method

Advantages of the GFM process:

Reduce equipment and material costs;

Rod, thermal and mixing equipment are excluded from the production process;

Use of dry quartz sand and vacuum hardening as a material;

Reduction of requirements for qualification of working personnel;

Possibility of complex automation of the whole process;

Reduction of the number of technological operations and equipment for finishing castings;

The use of inexpensive and relatively simple equipment;

Significant improvements in working conditions.