How can CNC machining manufacturers improve the machining accuracy and efficiency of workpiece?

First, programming skills

Nc programming is the basic work of NC machining. The quality of machining program directly affects the machining accuracy and efficiency of machine tool. We can use the inherent program skillfully, reduce the cumulative error of numerical control system, and use the main program and subroutine flexibly.

1, flexible use of the main program and subroutine

In the process of complex mold processing, it is usually processed in the form of one mold and many pieces. If there are several identical shapes on the mold, the relationship between the main program and the subroutine should be flexibly used, and the subroutine should be called repeatedly in the main program until the completion of processing. It can not only ensure the consistency of processing size but also improve its processing efficiency.

2, reduce the cumulative error of the numerical control system

The general use of incremental way for the programming of the workpiece, is the previous point as the benchmark for CNC machining, so the continuous execution of a number of programs will produce a certain cumulative error, so as far as possible in the programming to use the relative way of programming, so that each program segment to the origin of the workpiece as the benchmark, so as to reduce the cumulative error of the CNC system, to ensure the processing accuracy.

Machining precision is mainly used to produce the degree of product. Machining precision and machining error are both terms to evaluate the geometric parameters of the machined surface. However, the actual parameters obtained by any machining method will not be relatively accurate. From the function of the parts, as long as the machining error is within the tolerance range required by the parts drawing, the machining accuracy is considered to be guaranteed.

CNC machining accuracy refers to the actual geometric parameters (size, shape and position) of parts after processing want to learn UG programming to get learning materials in group 496610960 can help you with the degree of ideal geometric parameters. The difference between them is called machining error. The size of machining error reflects the machining accuracy. The larger the error, the lower the machining accuracy, and the smaller the error, the higher the machining accuracy. The following is a brief introduction to improve the workpiece processing accuracy of the methods are:

First, to adjust the process system

(1) Test cutting adjustment through test cutting - measuring dimension - adjusting the amount of cutting tool - cutting - again test cutting, so repeated until the required size. This method has low production efficiency and is mainly used for single piece small batch production.

(2) Adjustment method by pre-adjusting the relative position of machine tool, fixture, workpiece and tool to obtain the required size. This method has high productivity and is mainly used for mass production.

2. Reduce machine errors

(1) The rotary accuracy of bearings should be improved:

① the selection of high-precision rolling bearings;

② Adopt high-precision multi-oil wedge bearing;

(3) Adopt high precision hydrostatic bearing

(2) Improve the accuracy of accessories with bearing phase:

(1) Improve the machining accuracy of the box support hole and the spindle journal;

(2) Improve the machining accuracy of the surface matched with the bearing;

③ Measure and adjust the radial runout range of the corresponding parts, so that the error compensation or offset.

(3) Proper pre-tightening of rolling bearings:

① can eliminate the gap;

(2) Increase bearing stiffness;

③ The error of the homogenized rolling body.

(4) The spindle rotation accuracy does not reflect on the workpiece

Three, reduce the transmission chain transmission error

(1) Fewer transmission pieces, short transmission chain, high transmission accuracy;

(2) The use of slow transmission is an important principle to ensure transmission accuracy, and the closer to the end of the transmission pair, its transmission ratio should be smaller;

(3) The precision of the end parts should be higher than that of other transmission parts.

Four, reduce tool wear

(1) The tool must be re-sharpened before the tool size wear reaches the stage of sharp wear

(2) The selection of special cutting oil for full lubrication

(3) The tool material shall meet the technological requirements

5. Reduce the stress and deformation of the process system

(1) Improve the stiffness of the system, especially the stiffness of the weak link in the process system;

(2) Reduce the load and its change

Six, reduce the thermal deformation of the process system

(1) Reduce heat source and isolate heat source

(2) Balanced temperature field

(3) Adopt reasonable machine tool component structure and assembly datum

(4) Accelerate to achieve heat transfer equilibrium

(5) Control the ambient temperature

Seven, reduce residual stress

(1) Increase the heat treatment process to eliminate internal stress;

(2) Reasonable arrangement of technological process.

The above is the method to reduce the error of the workpiece processing, reasonable arrangement of the process can effectively improve the accuracy of the workpiece.

Two, the reasonable setting of processing routes

Reasonable setting of machining route and machining sequence is an important basis for optimizing workpiece machining programming. It can be considered in terms of machining trajectory and feeding mode.

In the workpiece numerical control milling processing, want to learn the UG programming to get learning materials in the group 496610960 can help you to combine the workpiece technology requirements to choose the appropriate feeding way, in order to ensure the workpiece cutting precision and processing efficiency. When milling the surface contour of the workpiece, the cutting line of the cutter should be arranged. As far as possible along the extension of the contour curve cut, cut out, so as to avoid the intersection of the knife mark. At the same time in the milling process should be based on the workpiece conditions to choose up-milling or inverse milling.

Three, tool selection and correct installation

Whether it is CNC machining or ordinary machining, the tool is directly acting on the workpiece, so its selection and installation when the workpiece machining accuracy and surface quality Z main factors. In particular, the workpiece is processed in the CNC machining center, the tool is stored in the tool library in advance, and shall not be replaced at will once the processing begins. So the general principle of tool selection is: easy installation and adjustment, good rigidity, durability and high precision.

Four, the reasonable choice of cutting parameters

The determination of cutting parameters is an important content of NC machining technology, its size is an important parameter of the main movement and feed movement of the machine tool, and has an important impact on the workpiece machining accuracy, machining efficiency and tool wear. The selection of cutting parameters includes cutting speed, back cutting quantity and feed quantity. The basic selection principle is: under the condition that the rigidity allows, rough machining takes the larger cutting depth, in order to reduce the number of cutting times, improve the productivity of the workpiece; Finishing generally takes a smaller cutting depth to obtain a higher surface quality.