Four basic principles for determining the clamping force of CNC tools

CNC tool: When designing a clamping device, the determination of the clamping force includes three elements: the direction, action point and size of the clamping force.

1. The direction of the clamping force of the CNC tool The direction of the clamping force is related to the basic configuration of the positioning of the workpiece and the direction of the external force on the workpiece. The following guidelines must be followed when selecting CNC tools:

① The direction of the clamping force should help to stabilize the positioning, and the main clamping force should be directed towards the main positioning base surface.

②The direction of the clamping force should be conducive to reducing the clamping force to reduce the deformation of the workpiece and reduce the labor intensity.

③ The direction of the clamping force should be the direction with better workpiece rigidity. Since the stiffness of the workpiece in different directions is unequal, different stress surfaces are also deformed differently due to the size of the contact area. Especially when clamping thin-walled parts, more attention should be paid to making the direction of the clamping force point to the direction with the best rigidity of the workpiece.

2. The action point of the clamping force of the CNC tool The action point of the clamping force refers to a small area where the clamping part contacts the workpiece. The problem of selecting the application point is to determine the position and number of clamping force application points when the clamping direction has been determined. The selection of the clamping force application point is the primary factor to achieve the best clamping state. Reasonable selection of the clamping force application point must comply with the following principles:

200 The roughness value of the ground surface is reduced from 2.0 to 1.1 for CNC tools

3. CNC cutting tools have low processing energy consumption and save manufacturing resources. During high-speed cutting, the volume of cutting layer material cut per unit power increases significantly. Such as the high-speed cutting of aluminum alloys by Lockheed Aircraft Company, the spindle speed is from 4 000 1/-. When increasing to 20 000, the cutting force decreased by 30^, while the material removal rate increased by a factor of 3. The material removal rate per unit power can reach 130~160 (1) than 'bullet tearing>, while ordinary milling is only 30 'bullet tearing). Due to the high removal rate and low energy consumption, the in-process time of the workpiece

It improves the utilization rate of energy and equipment, and reduces the proportion of cutting processing in the resources of the manufacturing system. Therefore, high-speed cutting meets the requirements of sustainable development strategies.

4. Numerical control tool simplifies the technological process and reduces the production cost. In some applications, the surface quality of high-speed milling can be comparable to that of grinding, and high-speed milling can be directly used as the last finishing process. Therefore, the technological process is simplified, the production cost is reduced, and the economic benefit is considerable.

Of course, high-speed milling also has some disadvantages, such as expensive tool materials and machine tools (including CNC systems), high requirements for CNC tool balance performance, and low spindle life.