A special machine tool is a machine tool that is specially designed for a specific part or a specific process, and is often an indispensable machine tool in an automatic production line type manufacturing system.
The earliest combination machine tool
The earliest combination machine was made in the United States in 1911 for machining automotive parts.
In the beginning, each machine tool manufacturer had its own common parts standard.
In order to improve the interchangeability of common parts of different manufacturers and facilitate user use and maintenance, in 1953, Ford Motor Company and General Motors and US machine tool manufacturers negotiated the principle of standardization of common parts of combined machine tools, that is, strict regulations the size of the contact between the components, but the structure of the components is not specified.
The general-purpose components can be classified into 5 types according to functions: a power component, a support component, a conveying component, a control component, and an auxiliary component.
The power components are the components that provide the main motion and feed motion for the combined machine tool, mainly including the power box, the cutting head and the power slide.
The support component is a structure for mounting a power slide, a cutting head or a clamp with a feed mechanism, including a side base, an intermediate base, a bracket, an adjustable bracket, a column, and a column base.
The conveying component is a component for conveying the workpiece or the headstock to the processing station, and mainly includes an indexing rotary table, a circular indexing rotary table, an indexing drum and a reciprocating moving table.
The control unit is a component for controlling the automatic working cycle of the machine tool, including a hydraulic station, an electrical cabinet, and a console.
The auxiliary components include a lubricating device, a cooling device, and a chip evacuation device.
In order to enable the combined machine tool to be used in small and medium batch production, it is often necessary to apply a group technology to concentrate the parts with similar structure and process on a combined machine tool to improve the utilization of the machine tool.
There are two common types of machine tools, such as the spindle box combination machine and the turret combination machine.
The future development of the combined machine tool will use more transmission motors such as adjustable speed motors and ball screws to simplify the structure and shorten the production cycle;
Adopt digital control system and spindle box and clamp automatic replacement system to improve process adjustability.
Incorporate into flexible manufacturing systems.
Special machine tools generally use multi-axis, multi-tool, multi-process, multi-face or multi-station simultaneous processing, and the production efficiency is several times to several tens of times higher than that of general-purpose machine tools.
Since the common components have been standardized and serialized, they can be flexibly configured as needed, shortening the design and manufacturing cycle.
Therefore, special machine tools have the advantages of low cost and high efficiency. Widely used in large batches and mass production, and can be used to form automatic production lines.
Special machine tools are generally used to machine parts of boxes or special shapes.
During machining, the workpiece generally does not rotate. The rotary motion of the tool and the relative feed motion of the tool and the workpiece enable drilling, reaming, counterboring, reaming, boring, milling, cutting internal and external threads, and machining the outer circle and end faces, etc.
Some combination machine tools use a turning head to hold the workpiece to rotate, and the tool can be used for feeding motion, and can also realize the outer circle and end surface processing of some rotary body parts (such as flywheel, automobile rear axle half shaft, etc.).