Common clamping methods for machining

1. Direct centering clip

This is a method of directly clamping the workpiece position on the machine tool by using a dial indicator, scoring disc, or visual inspection.

2. Marking and centering clip

The method is to draw the center line, symmetry line and machining line of each surface to be machined on the workpiece according to the part drawing, and then install the workpiece on the machine tool to determine the clamping position of the workpiece. Calibrate the machine tool and press the line.

This clamping method has low productivity, low precision, and high technical requirements for workers. It is generally used in the processing and production of single and small-batch parts, or where the blank size tolerance is large and cannot be clamped directly with a fixture.

3. Fixture

The fixture is specially designed according to the requirements of processing technology. The positioning element on the fixture enables the workpiece to quickly occupy the correct position relative to the machine tool and tool. The positioning accuracy of the workpiece can be guaranteed without correction, and the productivity of the fixture is high. The positioning accuracy is high, but it needs to design and manufacture special fixtures, which are widely used in batch and mass production.

Precautions for clamping in CNC processing

1. All clamps are horizontally long and horizontally short.

2. Vice clamping: the clamping height shall not be less than 10mm. The clamping height and machining height must be specified when processing the workpiece. The machining height should be about 5mm above the plane of the vice to ensure that the firmness of the vice is not damaged. This kind of clamping is general clamping, and the clamping height is also related to the size of the workpiece. The larger the workpiece is, the higher the clamping height is.

3. Clamping of splint: the pallet is coded on the workbench, and the workpiece is screwed on the splint. This kind of clamping is suitable for workpieces with insufficient clamping height and a large processing force. Generally, the effect of medium and large workpieces is good.

4. Code iron clamping: when the workpiece is large, the clamping height is not enough, and the bottom thread is not allowed to lock, the code iron clamping is adopted. This kind of clamping needs double installation. First code four corners, process other parts, and then code four sides, process four corners. After the second clamping, do not let the workpiece lose, and loosen the code first. You can also code both sides and deal with other sides.

5. Clamping of cutting tools: the diameter is more than 10mm, and the clamping length is not less than 30mm; The diameter is less than 10mm, and the clamping length is not less than 20mm. The tool should be clamped firmly to prevent the tool from being directly inserted into the workpiece.