Common faults and solutions of sanding machines, maintenance ideas and common sense of safe operation!

Sanding machine is a device that uses abrasive tools to sand (or grind) various boards and wood product components. Sanding machines are widely used in the wood-based panel and furniture industry, with large demand and many varieties, and have developed rapidly in recent years. The sanding machine is characterized by strong adaptability, which can improve the dimensional accuracy of the work and the surface roughness of the workpiece; it can process workpieces with large widths and narrow workpieces; it can process various planes and can also process Various surfaces; can be used for mass production as well as small batch production. When the sander is working, there will be various faults. You should learn to deal with and troubleshoot in time. Proper maintenance and maintenance will make the sander last longer.

01 Failure analysis of sanding machine

During the operation of the machine, some faults often occur, and these faults should be eliminated in time. If handled improperly, it may affect the production and increase the cost. This requires the operator to be familiar with the operating regulations, skilled operation, and timely elimination. Some faults are not serious when they are discovered, but if they are not handled properly, they will cause major faults and seriously affect production. The following is an analysis of common faults of sanding machines.

01-1 The limit of the sanding machine fails

There are limit switches on both sides of the belt. When the belt fails to swing and deviates to one side, touch the limit switch, the belt is released, and the main motor stops automatically, which can effectively protect the belt. Once the limit fails, it can cause damage to the abrasive belt, sparks from the friction frame, and even fire.

Solution: Therefore, the limit switch should always check whether the action is reliable.

01-2 Belt deviation

Generally caused by improper adjustment, the normal belt swing should be 15-20mm swing, 15-20 times/min swing frequency, moderate swing speed and consistent swing in and out speed. If it is in an abnormal state, over a long period of time, deviation may occur, especially if the swinging in and out speed is inconsistent, it is more likely to cause abnormal shutdown; the photoelectric switch is damaged, the solenoid valve is damaged, and the swinging cylinder is damaged.

Solution: Poor dust collection and high dust concentration will affect the normal operation of the photocell, and also cause the belt to deviate; the damaged accessories should be replaced in time to improve the dust removal effect.

01-3 Belt wrinkling

Once the abrasive belt is wrinkled, it can no longer be used. Generally, there are three possibilities for the wrinkling of the abrasive belt: the abrasive roller and the tensioning roller are worn, and the rollers are ground and repaired; The surface of the sand roller is rusted and rough, and the difficulty of swinging the sand belt causes the trend.

Solution: It can be treated by drying and drying; rust on the roller or sand with finer sandpaper.

01-4 Sand belt fracture

The fracture of the abrasive belt is mainly caused by the deviation of the abrasive belt, or the dullness of the abrasive belt is not replaced in time, or the sanding load is too large, or a hard object is encountered during the sanding process, or the quality of the abrasive belt itself is caused.

Solution: The abrasive belt should be avoided as far as possible, otherwise it may cause a fire. When the current is abnormal, it should be observed whether the abrasive belt has become dull, and if so, it should be replaced in time.

01-5 Abnormal vibration of main bearing seat

Under normal circumstances, the vibration of the main bearing seat is very small, and an experienced operator can judge whether it is normal by touching it. Generally, there is no condition to measure it with an instrument on site, but it can be judged by comparing it with other bearing seats, or it can be judged from the surface of the sanding board. bad to judge.

Solution: When there is abnormal vibration of the bearing seat, it can be considered that there are two reasons, one is that the bearing is damaged, as long as the bearing is replaced, the other is that the contact roller is worn and lost, and the original dynamic balance is destroyed, resulting in abnormal vibration. , in this case, the sand roller must be removed for maintenance.

01-6 The lower conveying roller rotates intermittently or does not rotate when the sander is empty

During work, the above situation cannot generally be observed. It can only be found when the car is empty. The reason is that the worm gear is partially or completely worn during the deceleration of the worm gear that transmits power.

Solution: Although it will not affect the work, other worm gears will shorten the life due to the increased workload and cause greater losses. Therefore, as soon as this condition is found, it should be replaced immediately.

01-7 The size of the sanding plate changes after changing the abrasive belt

When the cantilever of the sanding machine is loosened or locked, the position fluctuates greatly, and it should normally be within 0.5mm. If it is too large, when the locking block locks the cantilever, the difference in the locking force will cause a difference in the repeatability of the cantilever, causing the size of the sanding plate to fluctuate, which directly affects the sanding accuracy of the sander.

Solution: When the cantilever error is too large (more than 0.5mm), the locking block fixing bolts should be unscrewed and adjusted properly. At the same time, when replacing the abrasive belt, the locking force of the locking block should be consistent. 01-8 The main drive belt slips

In the Q-type and M-type sanders, high-speed flat belts are used. This transmission form is theoretically more efficient than the V-belt transmission. However, in actual use, there will be belt deviation or slippage, which is mainly caused by improper adjustment.

Solution: It should be adjusted in strict accordance with the requirements of the belt elongation rate of 1.5-2%, and the tightness of both sides of the belt should be consistent. After the adjustment is completed as required, carry out trial operation, especially when the current of the main motor suddenly increases, observe whether the belt deviates. If it deviates, it should be adjusted twice. 02 Care and maintenance of sanding machine

The first inspection: 4 hours after the new machine is used or replaced

Second inspection: 1 day after the previous inspection

The third inspection: 3 days after the previous inspection

Fourth inspection: 5 days after the previous inspection

Fifth inspection: 7 days after the previous inspection

Subsequent inspections: every other week.

Note: If one of the belts on the same pulley is broken and needs to be replaced, be sure to replace the other belts hanging on the same pulley at the same time. Even a second-hand sanding machine is an expensive thing. It is not a small item for individuals or companies, so the usual maintenance and maintenance must keep up.

03 Common sense of safe operation of sanding machine

1. The operator must be familiar with the performance, use and operation precautions of the machine before operation. It is strictly forbidden for novice operators to operate the machine alone, and non-related personnel are not allowed to approach the machine;

2. The operator is not allowed to wear clothes that are easily involved in the machine (such as ties, necklaces, loose clothes, etc.) Those with long hair should curl their hair, pull up or wear a hood, and it is strictly forbidden to wear gloves to operate the machine;

3. Do not dismantle the safety device on the sanding machine at will, and do not place any non-work objects on the workbench, such as wrenches, to avoid foreign objects jamming and causing damage to the machine;

4. Before turning on the power switch, be sure to confirm that all switches are in the OFF position. Before normal operation, check the cleanness and sharpness of the abrasive belt, and check whether the installation direction of the abrasive belt is correct (the arrow on the back of the abrasive belt points in the same direction as the rubber wheel). , Whether the specifications of the abrasive belt are suitable, whether the belt swing is moderate, whether the belt is tight, whether the running track of the conveyor belt is moderate, whether the conveyor belt is moderately tight, and whether the planer blade is installed correctly and firmly;

5. All protective covers must not be removed before processing. You must first determine whether the size of the wood is within the processing range of the machine, and adjust the correct processing thickness. If the wood is too thick, the conveyor belt will be stuck and broken. This equipment only It can be used for sanding wood with uniform thickness, but cannot be used for horizontal correction of wood bending, and triangular, diamond and arc-shaped wood cannot be processed. Be sure to pay attention to the workpiece without metal and other accessories to avoid damage to the machine;

6. During normal operation, please pay attention to the electrical load of the ammeter at any time to prevent the machine from tripping or the sandpaper being overwhelmed due to the overload of the machine, resulting in the cracking or breaking of the abrasive belt. Correction method: 1. Slow down the speed of the sanding belt; 2. Replace the sandpaper with coarser grit; 3. Raise the position of the rubber wheel or the sanding platen to reduce the amount of sanding;

7. When the operator is working, once the workpiece is placed on the conveyor belt, his hands should leave immediately, and the workpiece should be evenly placed on the conveyor belt, so that the abrasive belt and the rubber wheel are evenly stressed, so as to avoid unilateral wear and shorten the time between the abrasive belt and the rubber wheel. applicable life;

8. The surface of the sanding machine is adjusted up and down using a computer digital lifting controller. The adjustment of the table is strictly prohibited beyond the adjustment range of the controller, and the height of the table cannot be manually adjusted without permission, so as not to cause the table to be tilted or the data of the lift controller to be wrong. The speed of the conveyor belt adopts the infinite Variable speed adjustment, the speed should be adjusted while the machine is running.