Understanding: "Band Saw"

Band saw machine

A circular endless band saw blade is used as a sawing tool to perform a one-way continuous linear motion on two sawing wheels to saw the sawing machine. Mainly by the bed, saw wheel, saw wheel lifting and tilting device, band saw tensioning device, saw blade guide device, table, guide plate and other components. The bed is made of cast iron or steel plate welded. The saw wheel is divided into a strip-type upper saw wheel and a web-type lower saw wheel; the lower saw wheel is a driving wheel and the upper saw wheel is a driven wheel. The weight of the upper saw wheel should be 2.5-5 times lighter than the lower saw. The cutting speed of the band saw blade is usually 30~60m/s. The upper saw wheel lifting device is used for loading and unloading and adjusting the elasticity of the band saw blade; the upper saw wheel tilting device is used to prevent the band saw blade from falling off the saw wheel when sawing. The band saw blade tensioning device can give the upper saw wheel elasticity to ensure the stability of the band saw blade in operation; the old type uses the spring or the lever weight mechanism, and the new type uses the pneumatic and hydraulic tensioning device. The guiding device is commonly known as a sawing card to prevent the saw blade from twisting or swinging when sawing; the lower sawing card is fixed at the lower end of the bed, and the upper sawing card can be adjusted up and down along the vertical slide; the sawing structure has a roller type and a slider type The slider type is made of hardwood or wear-resistant plastic. The band saw machine is widely used in the wood industry. There are many types of machines. According to the process application, they can be divided into: large band saws, re-saw band saws and joiner band saws; positioning according to the saw wheel: vertical, horizontal And tilted, vertical and divided: right and left; according to the band saw machine installation points: fixed and mobile; according to the number of points: ordinary band saw machine and multi band saw Machine and so on. Band saw machine Woodworking car (1 sheet) The general woodworking band saw machine and the woodworking sports car are used together.

Band saw machine operation skills

First, familiar with the structure of the machine

The technical specifications of the band saw machine are different, but the structure of the band saw machine is similar, and its working principle is basically the same as that of a band saw used for building materials. Now, the construction features of the MJ346A machine are introduced.

The MJ346A joiner saw mainly consists of the frame (body), the upper and lower saw wheel, the work table, the adjustment hand wheel, the saw ratio, the braking device, the motor and other components. All transmission parts of the machine tool are sealed to ensure safe operation. The base, the upper and lower saw wheels, and the work surface are all made of cast iron. The two saw wheels with the same diameter are installed above and below the fuselage respectively. The upper saw wheel can be moved up and down to load and unload the saw blade and adjust the tension of the saw blade. The lower saw wheel is a driving wheel and is driven by a pulley. In order to reduce the wear and noise of the saw blade and the saw wheel, a layer of belt is wrapped around the rim of the saw wheel. The work surface is directly mounted on the fuselage with a gap in the middle as a passage for the saw blade. The saw is attached to the left side of the tabletop, and the worktable can be tilted at an angle of 40o. In order to prevent the saw blade swinging left and right during sawing, a saw clip is mounted on the underside and the top of the table top. The lower saw card is directly mounted on the underside of the work table. The upper saw card is mounted on the fuselage and can be moved up and down. There is a pulley behind the upper saw card. When the saw blade runs backwards, it acts as a limiter so that the saw blade does not fall. The machine uses a method of concentrated discharge of sawdust to ensure the cleanliness of the workplace.

Second, saw blade replacement and adjustment

When the saw blade is changed, first open the upper and lower guard doors, loosen the slide plate fixing screws, turn the lifting hand wheel, lower the upper saw wheel, and loosen the saw blade. Take out the old saw blade and put the repaired saw blade on the upper and lower saw wheel. Pay attention to the acute angle of the saw blade. Turn it downwards. Do not turn it up. Then turn the handwheel to raise the upper saw wheel and tension the saw blade. Then turn the saw wheel by hand to see if all the saw teeth are exposed on the outer surface of the rim of the saw wheel. If not, the upper saw wheel should be adjusted until the saw teeth emerge from the rim and the edges of the upper and lower saw wheels move smoothly. It is perpendicular to the work surface.

The tensioning device for saw blade is divided into two types: spring and pressure hammer (weight hammer). This machine is a spring device. The base tension should be determined based on the width, thickness, speed, etc. of the saw blade. Fingers are usually used to move the saw blade and the tension of the saw blade is used to determine if the tension is appropriate. In general, when the saw blade is pressed by hand, the bending of the saw blade is preferably between 3.2 and 6.4 mm.

The width of the saw blade should be compatible with the width of the wheel face of the sawing wheel, and it cannot exceed the width of the wheel face.

The saw blade is clamped in the middle of the saw blade, and the bottom of the saw teeth should be in line with the outer edge of the saw clip. The saw blade cannot be clamped too tightly. It should be able to slide in the middle of the saw clip and leave gaps on both sides. Each gap is about 0.04~0.08 mm. The back of the saw blade is about 0.8 mm away from the pulley. If the saw blade has touched the pulley when it is idling, it indicates that the saw blade is behind, or the pulley is in front, or the saw blade's fitting degree disappears. You should adjust the upper saw wheel or pulley, or remove the saw blade again. Check the roller trimming.

Third, the operating technology

The band saw machine is generally operated manually. When sawing a large workpiece, two people are required to work together. When linear sawing is used, the upper part of the workpiece is held steady, closely to the saw, and it advances horizontally. The long material can be started by a small operator so that the rear end of the workpiece is not lower than the table top. The feed rate should be properly controlled according to the nature of the material and the size of the workpiece. Do not push the tug or the impact saw blade. When workers saw the back 200 mm, the next step can be pulled. When the rear end of the workpiece approaches 200 mm of sawtooth, it is necessary to release the upper hand and pull the workpiece by the lower part. When the saw blade does not reach the maximum speed after driving, do not send the workpiece to avoid suddenly increasing the motor load.

In the case of a folder saw in the course of work, it is necessary to separate the workpiece by slicing the edges of the workpiece to the sides, and do not step back so that the saw blade does not fall. There are situations such as running saws and purlins (swinging the saw blade back and forth), that is, parking should be performed. The saw blade, sawing material (road), saw card, and saw wheel should be inspected. After the saw blade is in normal operation, it is sawn again. When wood chips on the workbench saw blade path are blocked, use a wooden stick to remove it. Never use your fingers to pluck. In order to prevent saw blade and saw wheel from sticking resin wood chips on the wheel surface and increase friction and resistance between saw blade and saw wheel, kerosene scrub can be used in the work.

Fourth, several typical workpiece sawing methods

1. The smaller the saw blade is, the smaller the curve radius of sawing is. According to the experience: a 12 mm wide saw blade can saw curves with a radius of curvature of about 70 mm; a 25 mm wide saw blade can saw a curve with a radius of curvature of about 250 mm; a 35 mm wide saw blade can saw the radius of curvature A curve of approximately 450 millimeters; a 50 millimeter-wide saw blade can saw curves with a radius of curvature of approximately 800 millimeters. When sawing a curve with a small radius of curvature with a wide saw blade, several radial saws can be sawed first and then sawn as a curve.

2. Straight inside corner sawing When sawing the right angle corner, you can drill a round hole at the corner first and then saw it in the direction of the arrow in the figure. When the turn angle is large, it can be directly sawn.

3. The bending sawing method The cutting sawing method generally adopts the method of scribe cutting. It is also possible to use the curve to model the sawing, that is to say the curve template up to the saw ratio, and the processed parts will be sent to the curve template and the corresponding curve will be sawed out. The curvature of the material and the width of the saw blade should be properly matched.

4. Bevel saw method When sawing the bevel, the machine table can be tilted to the desired angle. It is also possible not to adjust the table surface of the machine tool and to make a wedge-shaped plank with a corresponding slope fixed to the table surface. When the workpiece is sent along the wedge-shaped plank, the required slope surface is sawn.

5. When the tapering saw saws a large, small, and small workpiece, a template method is often used. That is, a piece of wood that is slightly longer than the workpiece is first sawn into the required slope, and the four sides are planed as template. The template should not be too thick, the small head should be kept at about 10mm, and then a tack and a wooden block of the template should be used as the tip. When the saw is cut, the workpiece will be pressed against the template, and the face template will be tightly attached to the saw. The template should be made in two pieces, and it should be used before and after the change to increase work efficiency.