Fittings and their components in various industries
In this article, we will fully examine the connections and its components in different industries, so that you, dear reader, can discuss topics such as types of connections in the industry, types of mechanical connections, types of permanent and temporary connections, types of metal connections, types of industrial connections and… Familiarize yourself so that you can name the types of connections and have a comprehensive and practical knowledge of it.
A machine consists of a combination of different components and classifications, including connecting devices, communication components, load carriers, and so on. All these parts are produced separately by different methods of reproduction, forging or forging, casting, rolling, machining (machining by traditional methods or machining with CNC types) and…, and after performing various production operations, They are assembled on top of each other permanently or temporarily.
Connections can be categorized in another way. Other classifications can be based on the type of connection, including mechanical joints (such as bolts, pins, spikes, etc.), metallurgical joints (such as welding and soldering), and chemical joints (such as various adhesives).
Advantages and disadvantages of permanent and temporary connections
Advantages and disadvantages of permanent connections
As is clear from the name of a permanent joint (such as welding, soldering, riveting (most commonly used in the aerospace industry) and gluing), we use this type of joint to get at least two different components together. We have to separate the Kurds, we have to separate them by cutting the connecting parts, destroying the connecting parts (breaking) and ŘŚ, so these cases are considered as the disadvantages of permanent connections.
The greatest advantage of this method for the connections and its components is to keep the parts together securely, without changing compared to other components.
Advantages and disadvantages of temporary connections
Temporary connections (such as bolts, pins, spikes, etc.) and the whole temporary connection help us a lot to be able to have the components together and easily whenever we need to separate them. Separate and reassemble. In fact, we will have easy assembly and disassembly with this type of connection. Figure 1 shows the types of permanent and temporary connections.
Permanent connections, welding - Welding Connection
The first is the joints and their components in various welding industries. Welding is one of the production and repair methods of industrial parts. In welding, we weld homogeneous parts together with the help of heat. In the production of industrial machines, various industries and in general all mechanical welding structures have great importance.
The most widely used types of welding methods in industry are Arc Welding, Oxyacetylene Welding, and Resistance Welding.
Arc Welding Characteristics - Arc wWelding
Welding in this method is by forming and establishing an electric arc between the edges of the workpiece to be welded with the electrode.
The connection of two pieces by melting the electrode causes the connection of two pieces, after they have cooled.
In general terms, this method of welding is also called electric welding.
Used for welding parts with different thicknesses.
The heat generated can reach up to 4,200 degrees Celsius due to the intensity of the electric current.
Oxyacetylene Welding Characteristics
In this method, heating with acetylene gas and oxygen and their combination does not occur.
Oxyacetylene welding is also called gas welding.
The chemical performance of the oxyacetylene flame can be adjusted by changing the ratio of oxygen to acetylene volume. (Neutralizing, oxidizing and carburizing)
Welding is usually done using a neutral flame setting. (Contains equal amounts of oxygen and acetylene.)
Oxidizing flame occurs when the flow of oxygen is high.
The carburizing flame is also obtained by increasing the flow of acetylene relative to oxygen.
Because steel melts at temperatures above 1,500 degrees Celsius, a mixture of oxygen and acetylene is perfect for this.
With this method, other gases such as propane, hydrogen and… can be used to bond non-ferrous metals at low melting points, for soldering and..
Usually the temperature created by this method is 3200 degrees Celsius.
Figure 2 shows Arc Welding and Oxyacetylene Welding with its components.
Characteristics of Resistance Welding
Connecting metals by applying pressure and passing electric current is called resistance welding.
No other materials are required to connect the parts with this method, and resistance welding is cost-effective in this regard.
Electrodes are typically made of copper alloys due to their good conductivity.
Cooling in this method is done by flowing water in the holes inside the electrode.
Used in the connection of thin sheets for the production of automotive, aerospace, industrial and parts.
It is highly controlled and reproducible in terms of production, and allows manufacturers to easily produce parts of the same quality in terms of quality control.
Resistance welding electrodes are made in the form of bushings, cylinders or pulleys. Figure 3 shows their types with a sample of the production part.
Permanent connections, soldering - Soldering
The second case is the joints and their components in different soldering industries. Soldering is the same as welding. That is, it connects the two parts by welding, with the difference that the working temperature and the connection of the parts are lower in soldering (soft soldering (less than degrees Celsius) and hard soldering (up to 1000 degrees Celsius)).
Solder is mostly used in various electronic and electrical industries. In this method, the melting point of the solder is lower than the melting point of the parts.
Soft solder is used to solder parts that need to be sealed. Soft solder alloy is usually made of tin, lead and zinc and used for hard soldering, copper, silver and bronze.
Different soldering methods include soldering iron, flame soldering, kiln welding and slitting sealing. Figure 4 shows the different types of shapes for the above methods for permanent connections.
Permanent connections, adhesives - Adhesive Connection
The third case of joints and its components in various industries is gluing. The use of glue to bond metals began with World War II. In prehistoric times, glue was used to glue rubber, paper, boards, and so on.
Primary adhesives were mostly made naturally and from the gums of various trees, but today many chemical adhesives are produced to connect different metals, such as connecting different sheets, connecting pipes, brake pads, made of aluminum, and so on. The adhesion force and the intermolecular force of the adhesive will be directly related to the adhesive strength. Of course, dust, oil and paint must be removed from the surface before gluing.
Advantages and disadvantages of gluing
Cheap and fast.
Due to the complete coverage of the surface, rust does not occur, unless the gluing operation is done well.
Cold gluing is done at room temperature (20 degrees Celsius), for connecting leather goods, bookbinding, china and..
Hot glue (80 to 200 degrees Celsius) requires heat. In some parts and special adhesives, the working temperature rises up to 450 degrees Celsius.
If the temperature rises, the resistance may decrease.
Permanent connections, riveting - Riveting Connection
The fourth case of fittings and its components in various industries is riveting. If it is not possible to weld and glue to connect the parts, the riveting method is used. For example, it is possible to connect two heterogeneous pieces with this method.
Riveting pursues two purposes of connection or sealing for connections. For example, for connecting steel structures, means of transportation, rails, machines, and… the purpose is to connect two parts. While in tanks, low pressure pipes are the target of sealing. In high pressure pipes, the goal is both good connection and good sealing.
Advantages and disadvantages of riveting
Due to the fact that the connection is not with heat (such as welding), there is no contraction and expansion.
Easy and convenient for assembly line workshops
The focus of tension and drilling for connection is one of the weaknesses of rivets.
It also makes the structure heavier.
Conclusion
In this article, the joints and their components in different industries, in terms of permanent joints (welding, soldering, adhesives and riveting) were discussed, mentioning their types, advantages and disadvantages. In the next article, temporary connections (such as bolts, pins, spikes, etc.) will be discussed.
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