What is a Cold Saw?

Metal cold cutting saw, or metal cold sawing, is the abbreviation of metal circular sawing machine sawing process. Full name in English: Circular Cold Sawing In the process of metal sawing, the heat generated by the saw blade sawing the workpiece is transferred to the sawdust through the saw teeth, and the sawed workpiece and the saw blade are kept cool, so the name is cold sawing.

There are 2 types of Cold Saw Blade:

(Compared to manganese steel flying saw)

Cold sawing and friction sawing are different, the main reason is that the cutting method is different:

Manganese steel flying saw blade: It is the high-speed rotating friction of manganese steel saw blade, which causes friction between the workpiece and the friction saw blade. During the sawing process, the friction saw and the workpiece temperature are very high. The contact with the welded pipe generates heat to disconnect it, which is really burnt . High flame marks can be seen on the surface.

High-speed steel cold cutting saw: It relies on the slow rotation of the high-speed steel saw blade to mill the welded pipe, so it can achieve no burrs and noise.

The sawing speed is fast, the cutting efficiency is optimized, and the work efficiency is high; the saw blade has a low deviation, and the section of the pipe being sawed has no burrs, which improves the sawing accuracy of the workpiece and maximizes the service life of the saw blade.

1. The cold-milling sawing method generates very little heat during the sawing process to avoid changes in the internal stress and material structure of the cut section. At the same time, the saw blade has a small pressure on the steel pipe, which will not cause pipe wall nozzles. Deformation.

2. The quality of the cut end face of the workpiece processed by high-speed steel cold cutting saw is good:

Optimized cutting method, high-precision cross-section after cutting, no burr inside and outside, flat and smooth cutting surface, no subsequent processing such as flat chamfering is required (reducing the processing intensity of the next process), saving process and raw materials; the workpiece will not The high temperature caused by friction changes the material; the operator's fatigue is low and the sawing efficiency is improved; the sawing process has no sparks, no dust, no noise, and environmental protection and energy saving.

3, long life, can be used

Select the cutting parameters according to the material and specifications of the sawing workpiece:

1. What tooth pitch, tooth shape, front angle parameter and back angle parameter of saw tooth; thickness of saw blade, diameter of saw blade;

2. What cutting speed is used

3. What tooth feed is used

The combination of the above various factors results in reasonable sawing efficiency and service life of the saw blade.

Jitter problem and its treatment

It is easy to shake when sawing, making the sawing effect poor, the equipment failure time is long, and even the saw blade bursts during the sawing process, or the bearing is burned due to the imbalance of the spindle bearing pressure. The surface size and burr of the cut steel exceeded the standard.

Measures taken: (1) Conventional method: take the leveling (set the level of the upper and lower rollers with the reference point) during the installation process, and use a pull line to determine that the V-shaped wheels are in a straight line so that the rollers are unified Height and the same straight line. According to the analysis of the force on the upper slide, a weight is added to the saw cover to balance the force and run smoothly.

Steel overlay problem and its treatment

When the sawing force is uneven, superimposed steel appears, especially when sawing small-sized steel, which is likely to cause damage to the saw blade and equipment.

Taken measures: (1) Add a set of pneumatic transmission torque compression device to the saw cut to eliminate the superposition phenomenon, protect the saw blade, and reduce the deformation of the steel after the radial force is exerted on the saw blade reaction force. . (2) Add a support roller at the saw cut, and after adding the support roller, cooperate with the pressing device to saw the steel after pressing. The quality of the sawing surface is significantly improved, and the damage rate of the saw blade is greatly reduced.

Excessive water spray area and treatment

The round steel enters the cold saw at about 320 ° C. The saw blade is sprayed with water to cool the saw blade during the sawing and unsawring process. The water spray area is too large in actual production, which causes the quality of the steel surface to decrease and also wastes water.

Treatment measures taken: (1) Change the original sprinkler type to sprinkler type, increase nozzles, use mist spray, and implement focused spray on sawing points. Because the end surface of the nozzle has a circular concave surface, the water can be atomized and sprayed uniformly, and the screw connection is used, which is easy to replace and is beneficial to maintenance work. (2) The saw cover is cooled by the surrounding cooling method, and the saw cuts and saw teeth are spray-cooled to cool the important parts in a targeted manner. (3) The injection valve is used during the feeding of the saw to increase the injection pressure, and the injection valve is closed when the saw is retracted.

The friction between saw cover and saw blade and its treatment

The saw cover and the saw blade rub against each other, resulting in the overall vibration of the upper slide, thereby causing the motor feet to loosen, etc. The long time will directly cause the bearing to burn or the motor to burn.

Taken measures: (1) The main shaft of the original saw cover is connected in an unreasonable manner. The force point of the saw cover pin is on the side plate on the side of the upper slide, which easily deforms the side plate and tilts the saw cover. By lengthening the pin, increasing the stress point, using the side plate as a fulcrum, and making the panel inside the upper slide as the real stress point, the structure of the saw cover becomes more reasonable, and similar accidents are avoided. (2) When replacing the saw blade, the crane cover is originally used to lift the saw cover, which easily deforms the saw cover. Now the hydraulic cylinder is used for lifting, and a cushion pad is added to the place where the steel comes in contact with after the flip of the saw cover, which properly solves the problem ^[1] .