Common problems and countermeasures in the installation of CNC turning tools

In view of the problems caused by the above-mentioned tool installation, when installing the tool, the cause should be analyzed according to the actual processing situation, and the correct installation method should be selected.

2.1 The solution when the installation position of the turning tool is improper and not firm
(1) Under normal circumstances, the tip of the turning tool should be at the same height as the axis of the workpiece of the turning tool. When rough machining and turning large-diameter workpieces, the tip of the tool should be slightly higher than the axis of the workpiece; during finishing, the tip of the tool should be slightly lower than the axis of the workpiece. However, when finishing the conical and arc contours, the tip of the turning tool should be strictly equal to the axis of the turning tool workpiece:

(2) When turning a slender shaft, when there is a tool holder or an intermediate support, in order to make the tip of the tool press against the workpiece, the tool should be properly offset to the right to form a leading angle slightly smaller than 90°. With the generated radial force, the slender shaft is pressed tightly on the support of the tool holder to avoid shaft jumping; when the tool holder of the turning tool is not supported by the tool holder or the intermediate frame, the tool is properly installed to the left to form a slightly The main deflection angle is greater than 900 to make the radial cutting force as small as possible:

(3) The protruding length of the turning tool should not be too long to prevent cutting vibration caused by poor stiffness, which will cause a series of problems such as rough surface of the workpiece, vibration, knife stabbing, and knife beating. Generally, the protruding length of the turning tool does not exceed 1.5 times the height of the tool holder. When other tools or tool holders do not collide with or interfere with the tailstock or workpiece, it is better to protrude the tool as short as possible. When the protruding length of the tool is as short as possible, when other tools or tool holders interfere with the middle frame of the tailstock, the installation position or order can be changed;

(4) The bottom of the tool holder should be flat. When using gaskets, the gaskets should be flat. The front ends of the spacers should be aligned, and the number of spacers generally does not exceed z pieces:

(5) The turning tool should be installed firmly. Generally use 2 screws to tighten and fix alternately, and then check the height of the tool tip and the axis of the workpiece again after tightening;

(6) When using indexable tools with machine clamps, the blades and gaskets should be wiped clean, and when using screws to fix the blades, the tightening force should be appropriate;

(7) When turning threads, the center line of the thread tool nose angle should be strictly perpendicular to the axis of the workpiece. Tool setting can be accomplished using a threaded tool setting plate and a bevel.

2.2 Whether the tool tip is at the same height as the workpiece axis
(I) When to consider whether the tool tip is at the same height as the workpiece axis

When using welded turning tools. It is necessary to consider whether the tool tip is at the same height as the axis of the workpiece. If conditions permit, it is best to choose an indexable turning tool with a machine clamp, which not only improves the sharpness of the blade, but also stabilizes the processing quality. After the tool wears out, it reduces the time for resetting the tool, and Due to the high manufacturing precision of the tool holder, the installation position of the blade is accurate, and the position of the tool tip and the bottom of the tool bar is fixed, so that after the tool is installed, the tool tip is at the same height as the axis of the workpiece, reducing or even avoiding the time for adjusting the height of the tool tip. However, after long-term use on the machine tool, the height of the tool holder is reduced due to the wear and tear of the guide rail, making the tip of the tool lower than the axis of the workpiece. When installing the indexable tool of the machine clamp, it is also necessary to consider whether the tip of the tool is equal to the axis of the workpiece.

(2) The method of detecting the equal height between the tip of the turning tool and the axis of the workpiece

The simple method is to use the visual method, but it is often inaccurate due to factors such as visual angle and light, and is usually only suitable for rough machining of large-diameter workpieces. In other processing situations, appropriate detection methods need to be used.

Commonly used methods for detecting the equal height between the tip of the turning tool and the axis of the workpiece

(3) Instructions for the use of self-made tool setting instrument and tool setting board

What needs to be pointed out is: height tool setting instrument. The tip of a knife should be adjusted to the same height as the axis of the spindle through trial cutting and other methods in advance, and then the tool setting instrument should be placed on the inner horizontal longitudinal guide rail surface of the machine tool and the guide rail surface of the middle slide plate, so that the tool setting plate After the bottom is at the same height as the tip of the knife, adjust the thickness of the washer separately. After locking the nut, it can be used as a tool for future installation. The tool setting instrument can be placed on different height planes according to different types of tools: according to different machine tools, the height of the tool setting plate can be adjusted by adjusting the gasket, and the tool tip can be flexibly used on the A or B side of the tool setting plate High, wide range of use.

The multi-functional positioning (height, length) plate can not only detect the height of the tool tip, but also detect the protruding length of the tool bar. It is also necessary to adjust the tip of a knife to the same height as the spindle axis, accurately measure the distance between the tip of the tool and the top surface of the tool holder, and then process the knife plate to ensure accuracy. The tool setting process of the tool setting plate is simple and accurate. But only for 1 machine tool.