Familiar with machine tool construction
The technical specifications of the band saw machine are different, but its structure is similar, and the working principle is basically the same as that of the band saw for wood production.
MJ346A joinery band saw machine is mainly composed of machine base (body), upper and lower saw wheels, working table, adjusting hand wheel, saw ratio, braking device, motor and other components. All transmission parts of the machine tool are sealed to ensure safe operation. The machine base, upper and lower saw wheels, working table, etc. are all made of cast iron. Two saw wheels with the same diameter are installed on the top and bottom of the body respectively, and the upper saw wheel can be moved up and down for loading and unloading the saw blade and adjusting the tension of the saw blade. The lower saw wheel is a driving wheel, which is driven by a pulley. In order to reduce the wear and noise of the saw blade and saw wheel, a layer of belt is wrapped around the rim of the saw wheel. The work surface is directly mounted on the fuselage, and there is a gap in the middle as a passage for the saw blade. The saw ratio is attached to the left side of the table, and the work table can be inclined at an angle of 40o. In order to prevent the saw blade from swinging left and right during sawing, a saw clip is installed on the bottom and the top of the table. There is a pulley behind the upper saw card, when the saw blade runs backwards, it acts as a restriction to prevent the saw blade from falling. The machine tool adopts the method of centrally discharging sawdust to ensure the cleanliness of the work place.
Saw blade replacement and adjustment
When replacing the saw blade, first open the upper and lower guard doors, loosen the fixing screws of the slide plate, turn the lifting handwheel to lower the upper saw wheel, and the saw blade is loose. The direction is downward, do not turn up, and then turn the lifting handwheel to raise the upper saw wheel and tension the saw blade. Then turn the upper saw wheel by hand to see if the saw teeth are all exposed on the outer side of the saw wheel rim. If not, adjust the upper saw wheel until the saw teeth are exposed on the rim, and move smoothly on the edge of the upper and lower saw wheels. perpendicular to the work surface.
The tensioning device of the saw blade is divided into two types: spring and pressure thallium (heavy hammer). This machine is a spring device. The base tension should be determined according to the width, thickness and speed of the saw blade. Usually, the finger is used to press the saw blade, and whether the tension force is appropriate is determined according to the left and right bending of the saw blade. In general, when the saw blade is pressed by hand, the bending degree of the saw blade should be between 3.2 and 6.4 mm.
The width of the saw blade should be adapted to the width of the wheel surface of the saw wheel, and should not exceed the width of the wheel surface.
The saw blade is clamped in the middle of the saw clip, and the bottom of the saw teeth should be in a straight line with the outer edge of the saw clip. The saw blade should not be clamped too tightly, and should be able to slide in the middle of the saw clip. There should be a gap on both sides, and the gap on each side 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 contacted the pulley when idling, it means that the saw blade is behind, or the pulley is forward, or the saw blade is properly tensioned. Adjust the upper saw wheel or pulley, or remove the saw blade and then Check the rolling trim.
operational technology
Band saws are generally operated manually, and two people should be equipped to work together when sawing larger workpieces. When performing straight-line sawing, hold the workpiece firmly with your hands, stick to the saw ratio, and advance it horizontally. The feeding speed should be appropriately controlled according to the material properties and the size of the workpiece, and it is forbidden to push, pull, and collide with the saw blade. When the worker passes the back of the saw by 200 mm, he can only pick up and pull. When the rear end of the workpiece is close to 200 mm of the sawtooth, you should let go of the hand when you get started, and the workpiece will be sawed by the lower object. When the saw blade does not reach the maximum speed after driving, do not feed the workpiece, so as not to suddenly increase the motor load.
If the saw is clamped in the process of work, the saw edge of the workpiece should be separated to both sides by force, and do not go backwards to prevent the saw blade from falling. In the event of running saw or blade (saw blade swinging back and forth), stop the vehicle and check the saw blade, saw material (road), saw card, saw wheel, etc., and then cut after the saw blade runs normally. When the passage of the saw blade on the work surface is blocked by debris, use a stick to remove it, and do not fiddle with your fingers. In order to prevent the saw blade and saw wheel from adhering to the resin sawdust and increase the friction and resistance between the saw blade and the saw wheel, kerosene can be used for scrubbing during work.
Saw Cutting Methods of Several Typical Workpieces
1. Jig sawing The narrower the blade, the smaller the curve radius for sawing. As a rule of thumb: a 12mm wide saw blade can cut a curve with a radius of curvature of about 70mm; a 25mm wide saw blade can cut a curve with a curvature radius of about 250mm; a 35mm wide saw blade can cut a curve with a curvature radius of about 250mm Curves of about 450mm; a 50mm wide saw blade can cut curves with a radius of curvature of about 800mm. When cutting a curve with a small radius of curvature with a wide saw blade, you can first saw several radial saw cuts, and then cut according to the curve.
2. Right-angle sawing method When sawing a right-angled corner, a round hole can be drilled at the corner first, and then sawing in the direction of the arrow in the figure. It can be sawed directly when there is a lot of room for turning the corner.
3. Bending sawing method Bending sawing generally adopts the method of scribing sawing. It is also possible to use the curve die sawing, that is, the curve template is placed on the saw ratio, and the workpiece is sent to the curve template, and the corresponding curve can be sawed. The curvature of the material and the width of the saw blade should be properly matched.
4. Bevel sawing When sawing bevels, tilt the machine table to the desired angle. It is also possible to make a wedge-shaped board with a corresponding slope and fix it to the table without adjusting the table of the machine tool. When the workpiece is sent along the wedge-shaped board, the required slope is sawn.
5. Conical sawing method When sawing a large workpiece and a small workpiece, the method of relying on a template is often used, that is, a piece of wood that is slightly longer than the workpiece to be processed is first sawed to the required inclination, and planed on all sides as a template. The template should not be too thick, the small head should be kept at about 10 mm, and then the tack of the template should be nailed to a block of wood as a stopper. When sawing, the workpiece should be pressed against the template, and the surface template should be close to the saw ratio. The template should be made in two pieces, and the front and back should be exchanged to improve work efficiency.