Familiar with machine tool structure

The technical specifications of band saw machines are different, but their structures are similar and their work The principle is basically the same as using a band saw for lumber production. Now, using the MJ346A machine tool as an example, we will introduce its structural features.

The MJ346A joinery band saw machine is mainly composed of a machine base (body), upper and lower saw wheels, work surface, adjustment handwheel, saw ratio, brake device, motor and other components. All transmission parts of the machine tool adopt sealed structures to ensure safe operation. The machine base, upper and lower saw wheels, work surface, etc. are all made of cast iron. Two saw wheels with the same diameter are installed at the bottom and top of the fuselage in sequence. The upper saw wheel can be adjusted on both sides 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. To reduce wear and noise on the saw blade and saw wheel, a belt is wrapped around the saw wheel rim. The work surface is directly mounted on the machine body, with a gap underneath as a passage for the saw blade. The saw is mounted higher than the right side of the table, and the worktable can be tilted at an angle of 40o. To prevent the saw blade from swinging left and right during sawing, a saw clip is installed above and below the table. The lower saw clip is directly mounted on the work surface, and the upper saw clip is mounted on the fuselage and can move up and down. There is a pulley in front of the upper saw clamp. If the saw blade runs backward, it will limit the saw blade and never cause it to fall. The machine tool adopts a centralized discharge method of sawdust to ensure the cleanliness of the working place.

 

Replacement and adjustment of the saw blade

Open it first when replacing the saw blade Guard the door up and down, loosen the fixing screws of the slide plate, turn the lifting handwheel to lower the saw wheel and loosen the saw blade. Take out the old saw blade, put the ground saw blade on the saw wheels on both sides, and pay attention to the direction of the sharp angle of the saw teeth. Down, you turn up, and then turn the lifting hand wheel again to make the upper saw wheel rise and tighten the saw blade. Then turn the upper saw wheel by hand to see if the saw teeth are all exposed on the inner side of the saw wheel rim. If not, adjust the upper saw wheel again until the saw teeth are exposed on the rim and move smoothly on both sides of the saw wheel edges. And vertical to the work surface.

The tensioning device of the saw blade is divided into two types: spring and thallium (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. Generally, fingers are used to press the saw blade, and the left and right curvature of the saw blade is used to determine whether the tension is appropriate. Under normal circumstances, when the saw blade is pressed by hand, the curvature 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 saw wheel surface and must not exceed the width of the wheel surface.

The gap on each side is about 0.04~0.08 mm. The rear back of the saw blade is about 0.8 mm away from the pulley. If the saw blade has contacted the pulley when it is idling, it means that the saw blade is back, or the pulley is back, or the tension of the saw blade has disappeared. The upper saw wheel or pulley should be adjusted, or Remove the saw blade and check for rolling and trimming.

 

Operating Technology

The band saw machine is generally operated manually. When sawing relatively large workpieces, two people should be equipped, and both sides should cooperate. When performing straight-line sawing, hold the workpiece firmly with your upper hand, close to the saw blade, and push it forward horizontally. For long materials, you can start slightly so that the rear end of the workpiece is never lower than the table. The feeding speed should be appropriately controlled based on the material properties and the size of the workpiece, and violent pushing, pulling, and collision of the saw blade are prohibited. When the uncle has passed the back of the saw 200 mm, he can start pulling. When the front end of the workpiece is 200 mm close to the saw teeth, the upper hand should be released and the workpiece should be sawed by relying on the lower object. After driving, when the saw blade has not reached the maximum speed, you feed the workpiece to prevent a sudden increase in motor load.

If the saw runs or moves (the saw blade swings left and right), you should stop the machine and check the saw blade, saw material (road), saw jam, saw wheel, etc. After the saw blade operates normally, start sawing again. If the saw blade path on the workbench is blocked by debris, use a wooden stick to remove it. Do not use your fingers to fiddle with it. To prevent resin wood chips from adhering to the surface of the saw blade and saw wheel and increase the friction and resistance between the saw blade and saw wheel, kerosene can be used to scrub them during work.

 

Several sawing methods of typical workpieces

1. Jig sawing method: The narrower the saw blade, the smaller the radius of the sawing curve. Based on experience: a 12 mm wide saw blade can cut curves with a curvature radius of approximately 70 mm; a 25 mm wide saw blade can cut curves with a curvature radius of approximately 250 mm; a 35 mm wide saw blade can cut curves with a curvature radius of approximately 250 mm. Curves of approximately 450 mm; a 50 mm wide saw blade can cut curves with a curvature radius of approximately 800 mm. When using a wide saw blade to cut a curve with a small radius of curvature, you can first cut a few radial saw kerfs and then cut according to the curve.

2． Straight inner corner sawing method: When sawing a right-angled corner, you can first drill a round hole in the corner, and then saw in the direction of the arrow in the figure. When there is plenty of room for turning, you can cut directly.

3. Bending material sawing method: Bending materials are generally sawed by scribing and sawing. You can also use curve template sawing, put the curve template on the saw blade, and send the workpiece around the curve template to saw the corresponding curve. The curvature of the material and the width of the saw blade should be matched appropriately.

4． Bevel sawing method: When sawing bevel, the machine table can be tilted to the required angle. You can also make a wedge-shaped wooden board with a corresponding slope and fix it on the table without adjusting the table of the machine tool. If the workpiece is sent along this wedge-shaped wooden board, the required slope will be sawed.

5． When sawing a workpiece with a larger end and a smaller end, the tapered sawing method often relies on a template. That is, a wooden board slightly longer than the workpiece is first sawn to the required slope, and then planed around. template. The template must not be very thick, and the small end should be kept at about 10 mm. Then nail a piece of wood to the big end of the template as a stop. When sawing, place the top of the workpiece against the template, and the surface template should also be close to the saw blade. above. The template should be made in two pieces and used interchangeably to improve work efficiency.

 

 

Safety usage regulations:

The saw machine uses the saw as a tool, and uses a bar saw or band saw to reciprocate, or a disc The rotary motion of the saw cuts and scores the wood. Common sawing machines include band sawing machines and circular sawing machines. Sawing injury accidents mainly include saw cutting injuries, saw blade breakage and ejection, wood impact injuries, etc. Sawing injuries are prevented through the use of safety guards and correct operation.

①The thickness of the band saw blade should be compatible with the matching band saw wheel. Avoid using large-thickness saw blades for small wheels, which may cause breakage and injury.

②The saw teeth should be sharp, and the tooth depth should not exceed 1/4 of the width of the saw blade.

④ Strictly control the transverse cracks of the band saw blade. If the crack is too long, it should be cut off and re-welded (see Table 1).

⑤The track of the sports car of a large band saw machine should be straight, with travel switches at both ends, and warning bars should be set on both sides of the sports car.