The automatic tool exchange system refers to a processing device that realizes the tool change requirements for continuous processing between part processes. The automatic tool exchange system consists of a tool magazine and a tool changing device. Among them, there are three main types of automatic tool change systems that are most widely used, namely, turret tool change system, spindle direct tool change system with disk tool magazine, and tool change manipulator tool change system with chain tool magazine. The tool magazine can be vertical or horizontal.
The tool exchange system of a machining center is also called an automatic tool changer (ATC). It usually consists of a tool magazine and a manipulator and is an indispensable part of the machining center. According to the tool exchange method, the tool exchange system of the machining center can be divided into two types: one is a tool exchange system with a manipulator; the other is a tool exchange system without a manipulator.
(This article is selected from Chapter 2, Section 4 of the "Machining Center Selection Guide" Automatic Tool Exchange System of the Machining Center)
1. Tool exchange system with manipulator
Most machining centers use a tool exchange system with a manipulator, as shown in Figure 2-29. The system consists of a tool magazine and a manipulator. When changing tools, first the manipulator takes out the prepared tools from the tool magazine and the used tools from the spindle at the same time (or separately), then exchanges the tool positions, and then takes out the tools from the tool magazine separately (or at the same time) Send it to the spindle, and return the used tools taken out from the spindle to the tool magazine.
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Figure 2-29 Tool exchange system with manipulator
2. Tool exchange system without manipulator
The manipulator-less tool exchange system is a device that can exchange tools without a manipulator, as shown in Figure 2-30. Since there is no manipulator, the tool changing steps such as tool removal and tool insertion in the tool exchange process are realized by using the relative motion between the tool magazine and the spindle box.
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Figure 2-30 Tool exchange system without manipulator
When a machining center using a tool exchange device without a manipulator exchanges tools, the tool magazine (spindle box) is first driven in, and the tool magazine (empty tool position) moves to the spindle head containing the tool or the spindle box (spindle containing the tool). head) moves toward the tool magazine. When the claws of the empty tool position of the tool magazine grab the tool on the spindle head, the relative motion between the tool magazine and the spindle box stops. Next is the tool shifting. The tool magazine and the spindle box begin to make relative movements of the tool until the tool is pulled out of the spindle head. Next is tool selection. Tool selection is when the tool magazine performs a rotary motion according to the instructions of the vertical manipulator-less tool exchange device until the tool selection is completed. Then comes the tool insertion. The tool magazine and the spindle box make relative movements until the new tool on the tool magazine is completely inserted into the spindle head and is tightened by the broaching mechanism. Finally, the tool magazine returns to its original position and the tool magazine leaves the spindle. The relative movement of the head (or spindle box leaving the tool magazine) until the tool magazine (or spindle box) returns to its original position.
3. Characteristics of tool exchange system
The manipulator-less tool exchange system is characterized by simple structure, low cost, and high reliability of tool change. However, the tool changing time is long and the tool magazine capacity is small, usually within 30 tools, so it is only suitable for small and medium-sized machining centers.
The characteristic of the robot tool exchange system is that the tool magazine configuration is flexible, the tool magazine capacity can be large or small, and the location can be determined according to the specific conditions of the bed. The configuration of the robot is also relatively flexible. It can configure different types of robots according to the position of the spindle box and the location of the tool magazine. In addition, the tool changing time of a robot tool changing system is generally shorter than that of a robot-free tool changing system. Some tool changing times are only 1 to 2 seconds, and some are even <1 second. However, this tool changing method has a complex structure, high cost, and is inconvenient for debugging and maintenance.
