How to set up tool points and tool change points in CNC machining?

How to set up tool points and tool change points in CNC machining?

CNC machining is a process method for machining parts on CNC machine tools. The process procedures of CNC machine tool processing and traditional machine tool processing are generally consistent, but have undergone significant changes. A mechanical machining method that uses digital information to control the offset of parts and tools. It is an effective way to achieve diversified, small batch, complex shape, high precision requirements, high efficiency, and automated processing of components.

Digital control technology originated from the requirements of the aviation industry. In the late 1940s, an American helicopter company proposed the initial concept of digital control machines. In 1952, the Massachusetts Institute of Technology developed a three coordinate control milling machine. In the mid-1950s, this type of CNC milling machine had already been used to process aircraft components. In the 1960s, digital control systems and programming work became increasingly mature and sophisticated, and digital control machines were used in various industrial sectors. However, the aerospace industry has always been the largest user of digital control machines. Some large aviation factories are equipped with hundreds of digital control machines, mainly cutting machines. The components of numerical processing include the main beams, skins, partitions, propellers of aircraft and rockets, casings of aircraft engines, shafts, discs, mold cavities of blades, and special steel surfaces of combustion chambers of liquid rocket engines. The initial stage of CNC machine tool development is based on continuous trajectory CNC machine tool (also known as contour control), which requires the tool to move along a specified trajectory relative to the part. In the future, we will vigorously develop and control digital control machines. Point control refers to the movement of a tool from one point to another, as long as it can ultimately reach the target accurately, without considering the movement path.

How to set up tool points and tool change points in CNC machining? Let's take a brief look together.

From which position does the CNC machining tool start moving to the specified position? Therefore, in the early stages of program operation, it is necessary to determine the position where the tool begins to move in the workpiece coordinate system. This position is called the program starting point or starting point, because it is the starting point of the tool relative to the workpiece during program operation. This starting point is usually determined, so it is also known as a large checkpoint. When preparing for the program, it is important to choose the correct cutting point position. The principle of setting the cutting point is to facilitate digital processing and simplify programming. Easy to find, easy to inspect during processing. The machining error caused is small. Tool points can be set on machining parts, fixtures, or machine tools. In order to improve the machining accuracy of parts, it is necessary to set as many tool points as possible based on the design benchmark or process foundation of the parts. When actually operating the machine tool, the tool point of the tool can be placed on the tool point through manual tool operation. That is to say, the tool point can be placed at a point that coincides with the tool point. "Tool position" refers to the position reference point of the tool, and the tool position of the turning tool is the center of the tool tip or tool tip arc. A flat end milling cutter is the intersection point between the tool axis and the tool bottom surface. The ball end milling cutter is the center of the ball end, and the drill bit is the tip of the drill bit. Manual operation results in low accuracy and efficiency in major inspections. Some factories use optical inspection mirrors, inspection devices, and automatic inspection devices to reduce inspection time and improve inspection accuracy. When it is necessary to change the tool during the processing, the location of the tool change should be specified. "Tool change point" refers to the position of the rotating tool when the tool is changed. The tool change point must be located outside the workpiece or fixture, so that the tool change will not come into contact with the workpiece and other parts.

Precision machining