Types And Working Principles of Sawing Machines

Ⅰ. The main types and characteristics of sawing machines

(1) Circular sawing machine

A circular saw machine uses a circular saw blade as the cutting tool. The cutting is completed through the rotational movement of the saw blade, and at the same time, the saw blade box will cooperate to perform feed motion. According to the different feed directions of the saw blade, it can be divided into three types: horizontal, vertical and pendulum. The horizontal circular sawing machine adopts a horizontal feed mode and is suitable for cutting long strip-shaped bar stock. Vertical circular sawing machines with vertical feed are mostly used for cutting sheet materials. The pendulum circular saw machine swings and feeds around a fulcrum, which can flexibly adjust the cutting Angle and is suitable for processing workpieces with complex shapes. In addition, there are dedicated circular sawing machines for specific scenarios, such as oscillating sawing machines used for cutting the gates and risers of large castings, as well as saw-drilling combined machine tools that integrate sawing and drilling functions.

The advantages of circular sawing machines lie in their fast cutting speed and high production efficiency, making them particularly suitable for large-scale, standardized material cutting operations. Its saw blades are mostly made of high-speed steel or equipped with hard alloy cutting heads, which can ensure the sharpness and durability of the cut. They are widely used in the raw material pretreatment stage in industries such as automotive manufacturing and general machinery.

(2) Band Saw Machine The core of a band saw machine is a circular saw band, which is tensioned on two saw wheels and driven by the saw wheels to perform continuous cutting. According to structural differences, band saws are mainly divided into two categories: vertical and horizontal.

The saw frame of the vertical band saw machine is set vertically. During cutting, the workpiece moves. It can not only cut the curved contours of sheet materials and formed parts, but also replace the saw band with a file chain or abrasive belt to achieve filing or grinding functions. It features a narrow cut, less material waste and low energy consumption. It is suitable for precise cutting of small workpieces and precision components, and is very popular in industries with high requirements for processing accuracy, such as punch press die manufacturing, shoe mold manufacturing and aerospace.

The saw frame of a horizontal band saw machine is arranged horizontally or at an Angle, and feeds by swinging along the vertical direction or around the fulcrum. The saw band is generally twisted by 40° to ensure that the saw teeth are perpendicular to the workpiece. It can be further classified into scissor type, double-column type and single-column type. Among them, the double-column band saw machine adopts a double-column structure and an integral cast bed, featuring high bending rigidity, small vibration amplitude during cutting, and the ability to carry heavy workpieces. It is suitable for batch cutting of large bars and plates. Horizontal band saws can be further classified into manual, automatic and fully automatic types based on their degree of automation. The fully automatic models are controlled by numerical control programming and are equipped with three-way clamping mechanisms, precise guidance and positioning functions, etc. They can achieve full automation of the cutting process and significantly improve production efficiency.

(3) Bow Sawing Machine: The saw bow equipped with saw blades on the bow sawing machine moves back and forth, and feeds by the saw frame swinging around a fulcrum. Its structure is simple, the volume is small, and the cost is relatively low, but the cutting efficiency is relatively low. The movement trajectory of the saw blade on a bow sawing machine can be either a straight line or an arc. When moving in an arc, the saw bow swings a small Angle around the fulcrum. Each saw tooth has a larger cutting depth, making chip removal easier and the efficiency relatively higher. This movement mode is mostly adopted by new bow sawing machines. Bow sawing machines are often used in small processing plants or maintenance workshops to cut and process some small metal parts.

Ⅱ. Core Structure and Working Principle of Sawing Machine

The structure of a sawing machine is complex and precise. Although different types of sawing machines have structural differences, their core components are basically the same, mainly including the base, bed, column, saw beam and transmission mechanism, guiding device, workpiece clamping device, tensioning device, feeding frame, hydraulic transmission system, electrical control system, lubrication and cooling system, etc.

The base is mostly a box-shaped structure welded from steel plates and serves as the foundation of the entire equipment. It is used to fix components such as the bed and column. Its inner cavity can also accommodate hydraulic oil tanks, cooling cutting fluid tanks, and water pumps, among other devices. The bed is generally made of cast iron and provides a stable support platform for all the moving parts of the sawing machine. The column serves as the guide rail for the movement of the saw frame, ensuring the accuracy and stability of the saw frame's movement.

The saw beam and transmission mechanism are the power core of the sawing machine, responsible for driving the saw blade to perform cutting movements. Take the band saw machine as an example. The transmission mechanism drives the saw wheel to rotate through the motor, which in turn drives the saw band to rotate at high speed. The function of the guiding device is to restrict the movement trajectory of the saw blade, keeping it always perpendicular to the workpiece during the cutting process and improving the cutting accuracy. It is usually composed of a guiding arm and a guiding head, and the guiding head contains a guiding roller and a guiding block.

The workpiece clamping device is used to fix the workpiece to be cut, preventing it from shifting during the cutting process and affecting the cutting accuracy. The hydraulic transmission system plays a crucial role in sawing machines. It controls the lifting of the saw beam, the clamping and releasing of the workpiece, the operation of the feeding mechanism, and other actions. Through the speed control valve, the feed speed can also be infinitely adjusted to meet the cutting requirements of different materials. The electrical control system is the "brain" of the sawing machine, responsible for coordinating the operation of various components to achieve automated and intelligent operation. CNC sawing machines even precisely control parameters such as the movement trajectory and feed rate of the saw blade through preset programs.

The lubrication and cooling systems are equally indispensable. The lubrication system provides lubricating oil for all moving parts, reduces wear and extends the service life of the equipment. The cooling system sprays coolant into the sawing area to lower the cutting temperature, enhance the durability of the saw blade, and at the same time wash away the chips to ensure the smooth progress of the cutting process.