Calculation and Design of Contact Machine Welding Loop

Contents

Introduction

1. Justification of connection type selection, welding scheme

2. Description of the main material and its weldability

3. Justification of welding cycle selection and calculation of welding mode parameters

4. Calculating Spot Welding Mode Parameters

5. Calculation of secondary contour of contact machine

6. Secondary Loop Feature Section Definitions

7. Determination of active resistance of secondary circuit

8. Determination of inductive resistance of the secondary circuit of the machine

9. Determination of the required secondary voltage of the machine

Passport data of MT- machine

BIBLIOGRAPHIC LIST

Introduction

In course design, the student deepens his knowledge and ability to independently solve engineering problems in the specialty: choose the material to be welded and develop welding processes; Select or develop welding equipment Select methods of quality control of welding process and welded product; use modern computing technology in calculations.

The subjects of the course project are technological developments for welding of various units of medium complexity from homogeneous and heterogeneous steels and non-ferrous metals. Peculiarity of welded articles structures consists in the fact that in order to perform their welding it is necessary to rebuild secondary circuit parts at stationary general-purpose machines, to develop secondary circuit parts, to develop welding modes with corresponding calculations, diagrams and drawings.

The tasks for the course design are issued in the form of a sketch drawing for the welded product with the main dimensions, purpose, material and release program.

Real technical materials of industrial enterprises can be used in the course project.

Justification of connection type selection, welding scheme

The explanatory note notes the main design features of the welded assembly with the indication of individual parts and their purpose. It is recommended to specify overall and connection dimensions in the product drawing. Explain the operating conditions of the article - the nature of mechanical loads, operating temperatures, requirements for structural stiffness and density (tightness) of the joints, the presence of an aggressive medium, the service life of the article, etc.

One of the most important principles used in the design of machines is the principle of processability of the design, which provides the possibility of manufacturing in specific production conditions with the least cost of time, labor and materials using the most advanced, economically justified production methods, guaranteeing at a given reliability the minimum number of failures during operation and the lowest costs for repair, restoration and maintenance.

It is allowed to change the specified design of the unit in order to improve its processability.

Based on the analysis of the design features and working conditions of the product, the type of connection (butt, overlapping, etc.) and contact welding methods (point, seam, relief, butt, etc.) is selected.

Description of the main material and its weldability

The most important circumstance in the development of the course design is the description and determination of the weldability of the metal from which the product is made.

The purpose of the material should be given in the description of the metal. It is also necessary to specify the chemical composition, mechanical, technological and physical properties of this material.

In general, weldability is understood to mean the ability of metals to form a strong bond without significantly deteriorating their processing properties in the cast core and near-seam zone. Before evaluating the weldability of a metal, it is advisable to establish the criteria for weldability.

The resistivity and thermal conductivity largely determine the relative rigidity of the welding regime.

thermal conductivity and thermal conductivity in combination with the duration of welding affect the size of the thermal influence zone, the temperature in the transition contact, the density of the welding current, etc.

The coefficient of linear expansion and temperature conductivity affect the residual stresses.

Welding technology is characterized by quality of surface preparation of welded parts and working contacts of electrodes, welding cycle. By grinding the surfaces of the parts and electrodes, the temperature in the transition contact decreases, and the operability of the electrodes increases.

There are good, satisfactory, limited and poor weldability. Metals that are welded on the simplest welding cycle have good weldability in a wide range of basic mode parameters, forming a strong joint. At that stability of welding process with minor changes of metal in welding zones is provided and high operability of electrodes is maintained.

Satisfactory weldability is provided by metals that are welded in a narrow range of basic mode parameters, forming a sufficiently strong joint on the simplest welding cycle. At the same time, satisfactory penetration of parts is obtained, but the welding process loses stability, splashes occur, significant metal-structural changes are observed in the cast core of the point and the near-axis zone, and electrode resistance decreases.

Poor weldability is provided by metals which, when welded in the simplest cycle, cannot provide satisfactory joint quality. The welding process is accompanied by splashes, electrodes are burned, the stability of the dimensions of the point is violated. It undergoes a significant change in the metal structure of the cast core of the point and the near-axis zone.

Общий вид машины МТ-1928.cdw

Сварочный контур МТ 1928.cdw