Basic composition of machining center

The composition of the machining center varies with the type, function and parameter of the machine. The machine tool itself is divided into basic components and selection components. The numerical control system has basic functions and selection functions. The machine tool parameters include main parameters and other parameters. Machine tool manufacturers can produce according to the requirements of users, but the basic functions and components of similar machine tool products are generally similar. Although there are various types of machining centers with different shapes and structures, they are mainly composed of the following parts in general:

1) The foundation part is composed of machine bed, column, beam, workbench, base and other components. They mainly bear the static load of the machining center and the cutting load generated during machining, and play a supporting and guiding role for each component of the machining center. Therefore, the foundation support must have sufficient stiffness, higher natural frequency and greater damping. These workpieces are usually cast iron or welded steel structures, It is the foundation component with the largest volume and weight in the machining center

2) The main shaft component consists of the main shaft box, main shaft motor, main shaft, main shaft bearing and other parts. The start, stop, speed change and other actions of the spindle are controlled by the numerical control system, and participate in the cutting movement through the tool installed on the spindle. It is the power output component for cutting. The spindle system is the main component of the machining center. Compared with the conventional machine tool spindle system, the machining center spindle system should have higher speed, higher rotary accuracy, and higher structural rigidity and vibration resistance.

1. The feed mechanism is composed of a feed servo motor, a mechanical transmission device, a displacement measuring element, etc. It drives the moving parts such as the worktable to form a feed motion. The feed drive mechanical system of the machining center directly realizes the feed and positioning of linear or rotary motion, which has a great impact on the accuracy and quality of machining. Therefore, the requirements for the feed system of the feeding center are motion accuracy, motion stability and fast response capability.

2. Numerical Control System (CNC)

The CNC part of the machining center is composed of CNC device, programmable controller, servo drive device and operation panel. It is the control center to complete the machining process. CNC system is generally composed of central processing unit, memory and input/output interfaces. The central processing unit is composed of memory, arithmetic unit, controller and bus. The main feature of CNC system is that it governs human storage. Data processing, interpolation and various control functions of the machine tool are all completed through computer software, which can increase the functions that are difficult to be realized by the Zuduo logic circuit. The computer can be connected with other devices through interface equipment. When the control object is changed, only the software and interface need to be changed.

3. Automatic tool change system (ATC)

Automatic Tool Changer (ATC) consists of tool magazine, manipulator, drive mechanism and other components. Tool magazine is a device for storing all tools used in the processing process; The tool magazine has many forms, such as disk type, drum type and chain type, with the capacity ranging from several to hundreds. When it is necessary to change a tool, a manipulator (or other ways) is extended to take the tool out of the tool magazine and put it into the spindle according to the command of the CNC system. The structure of the manipulator is different from the opposite position and structure of the tool magazine and the spindle, and there are also many forms, such as single arm type, double arm type, rotary type and track type. Some machining centers use the movement of the soil axle box or tool magazine to change tools without using a manipulator. Although the tool change process, tool selection mode, tool magazine structure, manipulator type, etc. are different, they are all controlled by CNC devices and programmable controllers, and the tool magazine and manipulator are driven by motors and hydraulic or pneumatic mechanisms to achieve tool selection and exchange. The contact sensor Oe installed in the mechanism can also realize the measurement of tool and workpiece errors.

4. Auxiliary devices include lubrication, cooling, chip removal, protection, hydraulic, pneumatic and detection systems. Although these devices do not directly participate in the cutting movement, they play a role in ensuring the efficiency, processing accuracy and reliability of the center. Therefore, they are indispensable parts of the center. Because the production efficiency of the machining center is very high, and the well can realize automatic processing for a long time, the problems of cooling, lubrication, chip removal, etc. are more prominent than those of conventional machine tools. The machining with large cutting amount requires powerful cooling and timely chip removal. The action of a large amount of cooling and lubricating fluid also puts forward higher requirements for the sealing and leakage of the system, thus promoting the production of semi closed and fully closed machine tools

5. Automatic pallet change system

In order to further shorten the non cutting time, some machining centers are equipped with two automatic workpiece exchange trays: one is installed on the workbench for processing, and the other is located outside the workbench for loading and unloading workpieces. When the workpiece on a pallet is processed, the pallet will be automatically exchanged to process new parts, which can reduce the auxiliary time and improve the processing efficiency.