There are multiple positioning methods in mechanical processing, each of which is used to ensure that the workpiece is accurately placed on the machine tool for precise processing. The following are some common mechanical machining positioning methods, and they are explained in detail:
Fixture positioning: A fixture is a device used to hold a workpiece and ensure its positioning. Fixtures typically have precise positioning surfaces to ensure accurate placement of the workpiece. This positioning method is suitable for various machine tools, such as milling machines, grinding machines, and drilling machines.
V-block positioning: V-blocks are devices used to locate cylindrical workpieces. The circular cross-section of the workpiece matches the V-groove of the V-block, ensuring accurate positioning of the workpiece. This method is usually used on lathes.
Parallel spacer positioning: Parallel spacer is a device used to adjust the height of workpieces, usually used on milling and grinding machines. They can be placed on the machine tool workbench or fixture to improve the accurate distance from the workpiece to the tool.
Diagonal block positioning: Diagonal blocks are equipment used to locate workpieces, usually used on milling and grinding machines. They are usually placed under the workpiece and positioned on the machine tool.
Three jaw chuck positioning: A three jaw chuck is a device used to hold circular workpieces, usually used on lathes. The workpiece is clamped by three evenly distributed grippers to ensure accurate positioning of the workpiece.
Gauge positioning: In some cases, direct gauges (such as sliding calipers, height gauges, block gauges, etc.) can be used on the workpiece for direct measurement and positioning. This method is suitable for situations that require quick and rough positioning.
Pattern positioning: The pattern positioning method usually includes adding positioning pins, holes, or grooves on the workpiece and fixture to ensure the correct placement of the workpiece. This method is commonly used in situations where multiple workpieces need to be positioned consistently.
Air cushion positioning: The air cushion positioning method is usually used for heavy workpieces, by creating an air cushion at the bottom of the workpiece to suspend it on the machine tool workbench. This method can be used for precise positioning and movement of large workpieces.
Spring fixture positioning: The spring fixture uses spring force to clamp the workpiece in a suitable position. This method is commonly used for positioning small components.
Friction positioning: The friction positioning method involves using friction to fix the workpiece on the machine tool. This method is commonly used in woodworking, grinding wheels, and grinding processes.
Each positioning method has its unique applications and advantages, and it is crucial to choose the appropriate positioning method based on specific workpiece and machine tool requirements. Accurate positioning is a key factor in ensuring machining quality and accuracy, therefore, the selection of positioning methods is crucial in mechanical machining.
