Machining is the process of using a machine to process a target shape. When designing parts and machinery, it is necessary to know what kind of machine can be used to perform what kind of processing. This is because without this knowledge, sometimes a shape that cannot be actually produced using the machine is designed. This time, we will explain the basics of machining, processing methods, and machine tools. Machining and machine tools Machining is the process of using machined materials to produce a target shape. There are many types, such as cutting and grinding. For example, drilling with a drill or cutting wood with an electric saw is also a type of machining. Using a machine can perform efficient processing while ensuring the quality of the processed product, such as the size.
The machines used for machining are generally called "machine tools." There are many types of machine tools, such as machines that cut materials and machines that melt materials and press them. For example, a drill can drill holes but cannot weld. The processing that a machine tool can perform is determined for each device. Therefore, you should choose a machine tool based on the target shape and the processing you want to perform.
Types of machining and machine toolsAdd WeChat: Yuki7557 to receive a macro program tutorialMechanical machining is roughly divided into three types according to the principle of machining: removal machining, forming machining, and combined machining.
Each machining principle has a variety of machining methods, and there are machine tools that match the machining methods. The following table briefly summarizes the outline of each machining method from the machining principle to the objects that can be machined. Machining principleMachining methodMachine tools usedOverview of machining methodsRemoval machiningCutting machiningLathe machiningLathe, NC latheRotate the material, press the tool on the material, and machine the materialMilling machiningMilling machine, machining centerPress the rotating tool on the fixed material, and machine the materialDrilling machiningDrilling machine, machining centerPress the rotating drill into the material, and drill the holeGrinding machiningGrinding machine, cylindrical grinderUse high-speed rotating grinding wheel to cut the material little by little for machiningGrinding machiningGrinding machine, drum polishing machineCutting and grinding more finely than grindingElectro-spark machiningElectro-spark machining, wire cutting machineUse the arc generated during discharge to bounce off the surface of the material for machiningForming machiningStamping Processing Punching machine Press the material strongly against the die to bend it into a shape that matches the die Sheet metal processing Plate bending machine uses a die called a universal die to bend metal sheets Casting Die casting machine Pour molten metal into a sand mold or metal mold and cool it down Forging Forging hammers and forging presses hit the metal material strongly to deform it Resin processing Injection molding Injection molding machine Injects heated molten resin into a metal mold and cools it down Welding Laser welding machine and spot welding machine Heats and melts the joint part of the (metal) material to join Bonding and brazing Brazing machine Use wax (molten metal) and adhesive to join materials The types of machine tools will be explained in detail in the following article.
Precautions during machining We have said that machine tools help to control quality such as dimensions, but there are also common precautions for processed products. The following are three key points to pay attention to when implementing machining. Official account "Mechanical Engineering Collection", a gas station for engineers! Machining accuracy
In machining, accuracy and dimensional tolerances vary depending on the processing method. Therefore, it is important to choose a method that can meet the accuracy requirements of the processed product. The following table summarizes the general accuracy standards by processing method. If the processing method is further subdivided and the accuracy changes greatly as a result, or if the accuracy setting method changes due to the processed shape, "-" is marked in the accuracy.
Processing Accuracy
In mechanical processing, the accuracy and dimensional tolerance vary depending on the processing method. Therefore, it is important to select a method that can meet the required accuracy of the processed product. The following table summarizes the general accuracy standards by processing method. If the processing method is further subdivided and the accuracy changes greatly as a result, or if the accuracy setting method changes due to the processed shape, "-" is marked in the accuracy.
Processing Principle Processing Method General Accuracy Removal Processing Cutting Processing Lathe Processing 0.03 Milling Processing 0.03 Drilling Processing 0.06 Grinding Processing 0.01 Grinding Processing – EDM Processing 0.01 Forming Processing Stamping Processing 0.15 Sheet Metal Processing 0.15 Casting 0.4～1.6 Forging – Resin Processing Injection Molding 0.1 Joining Processing Welding – Bonding・Brazing
Surface Roughness Generally speaking, the surface roughness of cutting processing is poorer than that of grinding processing. In EDM, a smooth cut surface can be obtained even without additional processing. In removal processing, the processing speed is closely related to the surface roughness of the processed surface. There is a tendency that the faster the processing speed, the rougher the surface, and the slower the processing speed, the smoother the surface. The surface roughness of stamping parts and sheet metal parts is also greatly related to the original surface roughness of the metal material, so it is difficult to define the relationship between the processing method and surface roughness. In casting, the surface is quite rough when using sand molds. Die casting can also obtain a smoother surface, but there is a problem of accuracy. When assembling with other parts precisely, the assembly surface is often subjected to removal processing such as cutting.
Burrs When cutting and welding are performed, burrs must also be paid attention to. In particular, it is best to realize that burrs are basically generated during cutting. In order to suppress the generation of burrs, it is also effective to adjust the feed direction and speed of the knife or carefully design the shape of the product.
In summary, mechanical processing refers to the use of machinery and tools to process materials, and there are many processing methods. In addition, the machines used at this time are collectively referred to as machine tools.
There are various types of machine tools, each with its own processing and characteristics. In the design of machinery and parts, knowledge of machine tools and processing is indispensable.
