Research and application of automatic deviation co

Research and application of automatic deviation correction device of belt conveyor

with the continuous and rapid development of national economy, belt conveyor has become the most important equipment of material conveying system in all walks of life. The deviation of conveyor belt (also known as belt) seems to be one of the most common faults of belt conveyor. This is mainly aimed at the rubber conveyor belt used for extruder feeding in rubber tire equipment

main factors of common belt deviation

1 Drum manufacturing error and installation deviation. 1) The manufacturing error of the outer cylindricity of the driving drum and the reversing drum is too large, so that the two ends of the drum are of different sizes, and the belt is subjected to a lateral force during operation, resulting in deviation. 2) The installation of the driving drum and the center line of the reversing drum is not parallel, so that the force on both sides of the belt is uneven, causing one side to be tight and the other side to be loose, and the belt is twisted and deformed, making the belt deviate to the tight side. 3) The center line of the driving drum or reversing drum is not perpendicular to the center line of the conveyor frame, and the deflection of the drum will make the belt deviation become more and more serious

2. Manufacturing error and installation deviation of the rack. 1) The manufacturing and installation error of the belt conveyor frame will lead to a large deviation between the center line of the belt conveyor and the theoretical center line, resulting in the deviation of the pulley and belt installation, resulting in the deviation of the belt operation. 2) When the design stiffness of the conveyor frame is poor, the frame will deform, especially when the belt runs under heavy load

3. The quality of belt manufacturing and joints produces geometric dimension (non straightness and uneven thickness) errors. 1) The belt vulcanization joint is misaligned or not straight, which will cause the tension on both sides of the belt to be different, and the belt will deviate to the side with high tension. 2) Belt deviation will occur if the belt itself is not straight, the two sides of the belt are not parallel, or the thickness of the belt in the width direction varies greatly. 3) Aging and deformation of the belt, serious grinding of the edges and dirty damage of the gear rod will also cause uneven stress distribution in the belt and deviation during operation

4. Manufacturing error and installation deviation of idler. 1) Excessive deviation of the outer circle cylindricity of the idler, non straightness of the idler (out of straightness), inflexible rotation, etc. will also cause belt deviation. 2) The belt deviation will also be caused by the non vertical installation of the idler center line and the non horizontal installation of the idler center line

5. The installation error of the belt tensioner and the improper adjustment of the tension on both sides of the conveyor belt will also cause the belt to deviate

6. Improper feeding direction and blanking position of belt conveyor will affect belt deviation

7. The deviation correction device is not considered in the design or the effect of the deviation correction device is poor

there are many factors that cause the belt deviation of the belt conveyor, but in the final analysis, it is caused by the unbalanced force on the conveyor belt during its operation, and there is a lateral component perpendicular to the moving direction of the conveyor belt

traditional belt deviation control and correction methods

according to the three common basic laws of belt deviation: "run tight but not loose", "run high but not low", "run after but not before", that is, if the tightness (tension) on both sides of the belt is different, the belt will move to the tight (tension) side during operation; If the height of the two sides of the belt with the PVC grade of hs11300 is different, the belt will move to the higher side during operation; If the idler support device is not installed on the vertical section with the belt running direction, but one end is in front and one end is in the back, the belt will move to the rear side during operation. At present, the following methods are commonly used to prevent deviation:

1) improve the processing, manufacturing and installation accuracy of the driving drum, reversing drum, idler support and frame of the belt conveyor

2) select the conveyor belt with good quality, that is, the belt with uniform thickness, consistent length, flat and non loose edges, and adopt the belt with good bonding (vulcanization) of multi-layer ladder inclined interface

3) according to the law of "running tight but not loose" of the belt, the driving drum and reversing drum of the belt conveyor can be designed into a drum shape. On the one hand, it can compensate for the bending deformation of the drum under the belt tension, and on the other hand, it can make the belt have a certain self centering ability in operation, so as to prevent the belt deviation more effectively. Try to control the belt deviation within the allowable range

4) the method of adjusting the tensioning mechanism is generally divided into gravity counterweight tensioning method (mostly used in the tail and middle of the conveyor), and mechanical screw or screw tensioning method. The tension on both sides of the belt can be adjusted separately and without stopping the machine

5) adjust the roller method. Long holes can be made in the high and low or front and rear positions of the bearing seat of the drum, and the high and low or front and rear positions of both ends of the drum can be adjusted respectively, so as to adjust the direction of belt deviation

6) adjust the idler support (or frame) method. The direction of belt deviation can be changed by adjusting the horizontal angle between the idler centerline and the belt running direction to be slightly greater than 90 degrees or slightly less than 90 degrees, so as to achieve the purpose of belt deviation correction. You can also correct the deviation of the belt according to the basic law of "running high but not running low" by adjusting the height difference between the two ends of the idler or the height difference between the two sides of the frame

7) mucus removal method. If the belt conveyor operates continuously for a long time in a relatively harsh working environment, it is necessary to clean the driving drum, reversing drum, idler and both sides of the belt regularly to remove the adhesive and prevent the belt from deviation

8) adjust the feeding or blanking position and height to minimize the external lateral force on the belt and prevent the belt from running off track

the common shortcomings of the above methods to prevent deviation, adjust deviation and correct deviation are: 1) belt deviation during the operation of belt conveyor must be found and handled in time, otherwise it will inevitably cause material leakage, belt edge wear, and even production stop or equipment damage in serious cases. 2) Most methods can only be stopped and adjusted manually, which seriously affects the production progress and production efficiency of the production line. The deviation adjustment efficiency is low, time-consuming and laborious, and it must be debugged repeatedly. 3) The requirements for working experience and technical training of operators and maintenance personnel are high. 4) The processing and installation accuracy of rollers, idlers and frames is high, and the processing and manufacturing cost is high

a new pneumatic automatic deviation correction method of belt conveyor

the purpose to be achieved by adopting the pneumatic automatic deviation correction method

1) appropriately reduce the processing and installation accuracy of the pulley, idler, frame and other parts of the belt poly (4 fluoroethylene PTFE) conveyor, and improve the processing technology and the economy of equipment manufacturing. 2) For the conveyor belt that deviates during the operation of the belt conveyor, do not stop the machine, automatically detect, automatically identify the deviation condition, and automatically correct the deviation. Improve production efficiency and reduce losses caused by shutdown and deviation adjustment. 3) The high training requirements for operators and maintenance personnel can be appropriately reduced. 4) Correct deviation quickly and reliably. 5) The correction accuracy should be high

composition of pneumatic automatic deviation correction device

this kind of pneumatic automatic deviation correction device is generally composed of 1 or 2 groups of deviation correction roller devices (each group has a set of fixed end device in the form of hinge, a set of adjustment end device with cylinder push, a set of deviation correction roller) and a group of belt deviation position detector

usually, a group of deviation correction idler devices are installed near the driving drum and the reversing drum of the belt conveyor; Install a group of belt deviation position detection controllers near the driving drum and close to the fixed end of the deviation correction idler. We will use our future actions to return you. We hope that people from all walks of life and users from all walks of life will supervise and give advice. The deviation correction idler is hinged with the support plate installed on the frame at the fixed end of the deviation correction idler, so that the deviation correction idler can rotate an angle around the hinge point on the fixed end under the push of the air cylinder at the adjustment end. Thus, the adjustment end of the deviation correction idler can control the angle change between the axis of the deviation correction idler and the belt running direction (greater than or less than 90 degrees) under the action of the air cylinder, and achieve the purpose of correcting the deviation of the belt in operation according to the running law of the belt "after running, but not before running". The length of the deviation correction idler is determined according to the width of the conveyor

deviation correction principle and action process

when the belt conveyor is connected to the air source and the power starts to work, the two position five way solenoid valve (Y5) is in the state of power loss, the belt of the belt conveyor runs forward according to the feeding direction, the guide pulley on the belt deviation position detection controller has not yet contacted the belt edge, and the controller is in the initial position under the action of the tension spring (Figure 1), The lever air circuit reversing valve (E12) on the controller is in the state of compressing the valve core, and the cylinder piston rod on the movable end of the deviation correction idler is in the right end position. Make the axis of the deviation correction idler form an included angle of about 91.1 degrees with the belt running direction (Figure 1). According to the law of "running after running, not before running", at this time, the belt will only move towards the guide pulley on the belt deviation position detection controller, and push the guide pulley to drive the connecting rod to rotate an angle counterclockwise with point a as the center, so as to reset the valve core of the mechanical lever air circuit reversing valve (E12) under the action of the built-in spring of the valve, so as to realize the automatic reversing of the air circuit, Make the piston rod of the two cylinders move to the left end position, so that the axis of the deviation correction idler forms an included angle of about 88.9 degrees with the belt running direction (Fig. 2). Similarly, according to the law of "after running, not before running", at this time, the belt will move away from the guide pulley of the controller to detect the deviation position of the belt. When the edge of the belt is close to separating from the guide pulley of the controller, under the action of the tension spring, the connecting rod will re compress the spool of the change-over valve, so that the mechanical lever air path change-over valve (E12) can realize the air path change-over, and push the cylinder piston to move to the right end again, Make the included angle between the axis of the deviation correction idler and the belt running direction return to about 91.1 degrees, so as to realize the return of the belt deviation direction. It is precisely when the guide pulley is repeatedly pushed or loosened by the belt edge, the mechanical lever valve is alternately compressed or released, and the air circuit reversing valve alternately reverses, driving the pistons of the two cylinders to move back and forth, driving the swing of the deviation correction idler, so that the included angle between the deviation correction idler axis and the belt running direction changes within the range of 88.9 degrees to 91.1 degrees, realizing the real-time dynamic automatic continuous deviation correction of the belt

deviation correction effect

since the automatic deviation correction device was applied to various belt conveyor equipment of the author's company in 2004, the deviation correction effect has been particularly ideal. For many years, there has never been a case that the normal operation of the equipment has been affected by the deviation of the belt conveyor. This technology has obtained the national utility model invention patent. (end)