JP6103232B2 - Looseness detection device and method for endless belt and endless link chain - Google Patents

Description

  The present invention relates to an apparatus and method for detecting looseness caused by elongation occurring when a belt or a link chain is used, and more particularly to an endless type that is hung around a sprocket and a pulley on a driving side and a driven side. The present invention relates to an apparatus and a method suitable for detecting looseness of a belt or a link chain.

  Endless belts and link chains used in continuous transport devices such as conveyors and various rotational force transmission mechanisms loosen over their entire length due to wear and wear of connecting parts, or elongation of the material itself, over time. Is known to occur. When the slack to the belt or link chain hung around the pulley or sprocket increases, the belt slips and the link chain causes tooth skipping. In addition, if the looseness becomes significant, the belt and the link chain may be broken or detached, and it may be necessary to stop the operation of the machine or may cause a serious accident.

  As techniques for detecting the elongation of a belt or link chain that causes loosening, various techniques have been proposed as disclosed in Patent Documents 1 to 3. Patent Documents 1 and 2 are techniques for detecting the extension of the conveyor belt, and Patent Document 3 is a technique for detecting the extension of the link chain.

  Patent Documents 1 and 2 each disclose a technique in which two magnetic markers are arranged on a conveyor belt, and the elongation generated on the conveyor belt is detected by calculating the distance between the magnetic markers.

  On the other hand, Patent Document 3 discloses a technique in which the distance of the unevenness on the upper surface of the link chain is measured using a laser displacement meter, and the elongation generated in the link chain is detected based on the change in the distance of the unevenness. Yes.

  On the other hand, as a means for directly detecting looseness of a belt or chain that is wound between a driving wheel such as a pulley or a sprocket and a driven wheel, the bending of the belt or chain that occurs on the rear side (feeding side) of the driving wheel. It is known to measure the amount and tension and calculate and judge the degree of looseness based on this value.

JP-A-57-48521 JP 2006-44853 A JP-A-11-325829

  Both technologies have the advantage that the elongation can be detected while the conveyor or the device is operating. However, the detection of elongation by these technologies is that the change can be detected by making continuous measurements based on the length of the belt and chain that are healthy. Cannot be determined from empirical values. For this reason, it is impossible to measure an event such as whether or not the belt or chain stretch in the existing equipment that is not continuously measured is within a healthy range.

  In addition, a lubricant such as grease is applied to the outer periphery of the chain, and various dusts are often attached in the usage environment. For this reason, accurate measurement with a laser displacement meter itself may be difficult.

  Therefore, in the present invention, an endless belt that can detect looseness (play) generated in a belt or a link chain even in existing equipment, and can easily detect elongation regardless of the state of a detection target. An object of the present invention is to provide an endless link chain slack detection device and method.

  In order to achieve the above object, an endless belt and endless link chain slack detection device according to the present invention is a device for detecting the slack of an endless belt or endless link chain wound around a driving wheel and a driven wheel, Drive means for rotating the drive wheel; and control means for supplying a command signal for forward rotation and reverse rotation to the drive means and supplying a current for obtaining a predetermined number of rotations. The control means receives feedback of the rotational speed of the driving means, compares the feedback rotational speed with the predetermined rotational speed, and increases the current value to obtain the feedback rotational speed Or, when the reverse rotation command signal is given from the control means, the value of the current supplied to the driving means is changed from the current value at no load rotation to the load rotation speed. Based on the time to shift to the current value, and having an arithmetic unit for calculating the loosening degree of the endless belt and said endless link chain.

  Further, in the endless belt and endless link chain slack detection device having the above-described characteristics, the calculation of the slackness of the endless belt and the endless link chain is calculated from the current value at the time of the no-load rotation based on the load rotation. It is preferable that a database indicating the relationship between the transition time to the current value and the degree of looseness is recorded in the storage unit of the control means, and the calculation unit is derived based on the time recorded in the database.

  By having such a feature, it is possible to derive the amount of elongation of the belt or the link chain without performing a complicated calculation based on the detected value.

  Further, the looseness detection method of the endless belt and the endless link chain of the present invention for achieving the above object is a method of detecting the looseness of the endless belt and the endless link chain that are wound around the driving wheel and the driven wheel, Based on the time from when the drive wheel is normally rotated to when the drive wheel value changes due to a reverse rotation and a load change that occurs after the reverse rotation, the endless belt and the endless link chain It is characterized by deriving the degree of looseness.

  Further, in the endless belt and endless link chain slack detection method having the above-described characteristics, the slackness of the endless belt and the endless link chain depends on the time until the change of the drive current value, the endless belt and the endless link chain. The looseness of the endless link chain may be derived from the associated database.

  By having such a feature, it is possible to derive the amount of belt or link elongation without performing a complicated calculation based on the detected value.

  According to the endless belt and endless link chain slack detection device and method having the above-described features, it is possible to detect slack (play) occurring in the belt or link chain even in existing equipment, and to be detected. Regardless of the state of the object, it is possible to easily detect the elongation.

It is a figure which shows the basic composition of the looseness detection apparatus of the endless belt which concerns on embodiment. It is a figure which shows a mode that the looseness has arisen on the sending side of the belt hung around between the driving wheel and the driven wheel. It is a figure which shows a mode that the slack has arisen on the sending side of the link chain hung around between the driving wheel and the driven wheel. It is a graph which shows the mode of the change of the supply current which arises after the command signal to reversely drive to a drive means is output until a drive means shifts from a no-load rotation to an applied load rotation. It is a perspective view which shows the dust removal apparatus as one of the specific examples of the apparatus which can apply the looseness detection method of the endless belt and endless link chain which concern on this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the endless belt and endless link chain slack detection device and method of the present invention will be described below in detail with reference to the drawings. First, with reference to FIG. 1, a basic form of a looseness detection device (hereinafter simply referred to as a detection device 10) of an endless belt (including a chain) will be described.

  An object to be detected by the detection apparatus 10 according to the present embodiment is a belt or a chain (collectively referred to as a belt 16) spanned between a driving wheel 12 and a driven wheel 14 configured by pulleys, sprockets, and the like. . A driving means 20 such as a motor (for example, a DC motor) is connected to the rotating shaft 12 a of the driving wheel 12 via a transmission 18. The drive means 20 is connected to a control means 22 for controlling the rotation of the drive means 20 and detecting the drive state. The control means 22 is connected to a power source (non-power supply) for supplying power to the drive means 20. And a display means 28 such as a monitor for displaying a rotation state, supply current value, looseness detection result, and the like.

  First, the control means 22 controls the current value supplied from the power supply so as to drive the drive means 20 at a predetermined rotation speed (reference rotation speed), and outputs it to the drive means 20. Take on. The control unit 22 is provided with a calculation unit 24 and a storage unit 26, and also plays a role of performing calculation, comparison, detection, and the like based on various feedback values. In addition to outputting the current value to the drive unit 20, the control unit 22 also plays a role of outputting a calculation result and a feedback value to the display unit 28 and the like. The reference rotational speed can be arbitrarily determined based on the efficiency and operating speed of various devices.

  The increase / decrease of the current value is determined by feeding back the rotation speed of the drive means 20 to the calculation unit 24 of the control means 22. That is, when the rotation speed fed back is compared with the reference rotation speed, if the rotation speed is high, a command signal for decreasing the current value is output, and control is performed so that a current value lower than the current value is output. . On the other hand, when the rotational speed is low, a command signal for improving the current value is output, and control is performed so that a current value higher than the current value is output.

  Here, when the driving means 20 is a DC motor, it can be said that the motor torque (T) and the current value (I) are in a proportional relationship from the relationship of T = Kt × I (Kt is a torque constant of the motor). ). The rotational speed N of the motor can be expressed as N = V−R × I based on the power supply voltage (V = constant), the internal resistance of the motor (R = constant), and the current value (I). Here, since V and R are constant, the change in the rotational speed (N) is caused by the change in the current value (I). Therefore, when the rotational speed changes based on a change in the load on the motor, it is possible to adjust the rotational speed to the reference rotational speed by changing the current value and performing torque control. From this, the change in the current value output from the control means 22 can be regarded as an increase or decrease in the load on the drive means 20.

  FIG. 2 shows a state of the belt 16 wound around the driving wheel 12 (driving pulley) and the driven wheel 14 (driven pulley). FIG. 3 shows a state of the link chain 16a hung around the drive wheel 12 (drive sprocket) and the driven wheel 14 (driven sprocket). As can be seen from FIGS. 2 and 3, the drive wheels 12 of FIGS. 2 and 3 have their forward rotation directions opposite to each other, but both are belts 16 and link chains located on the pull-in side with respect to the drive wheels 12. Whereas 16a is stretched, the belt 16 and the link chain 16a located on the delivery side are bent (loosened).

  When a command signal for reversely rotating the drive wheels 12 is output from the control means 22 to the drive system in such a state, the rotation of the drive means 20 is stopped once, and then, after no load rotation, to a load rotation. And migrate. Here, in the no-load rotation, after the driving wheel 12 starts reverse rotation, the bending (loosening) that has occurred on the delivery side of the belt 16 or the link chain 16a is eliminated, and the tension on the pull-in side occurs. It takes time. For this reason, the time from the no-load rotation to the transition to the applied rotation varies depending on how the bending occurs. That is, when the deflection (slack) is small, the no-load rotation time in the driving means 20 is short, and when the slack is large, the no-load rotation time is long.

  FIG. 4 shows an example of a change in current value over time when the drive wheel 12 is shifted from forward rotation to reverse rotation. In FIG. 4, a graph indicated by a solid line is a current value change (reference value) when the looseness of the belt 16 or the link chain 16 a is within a healthy range, and a graph indicated by a broken line is the belt 16. FIG. 4 shows a change in current value (actual measurement value) when the looseness of the link chain 16a increases beyond a healthy range. In the graph, the part where only the solid line appears is a part where the solid line and the broken line overlap.

  In consideration of FIG. 4, first, even if the looseness occurring in the belt 16 or the link chain 16a is within a healthy range or beyond the healthy range, during steady operation (at the time of normal rotation) It can be read that there is almost no difference in the supplied current values. This is because there is no difference in torque required for maintaining the rotational speed of the drive wheels 12 during steady operation.

  Moreover, it can be read from FIG. 4 that there is no difference in the rise of the current value when the rotation is stopped and the reverse rotation of the drive wheel 12 is started. This is a period until the belt 16 and the link chain 16a which are positioned on the delivery side and have been bent with respect to the drive wheel 12 rotated in the reverse direction until the tension is generated (so-called backlash period), the driving means 20. This is because the motor is to start rotating in a no-load state.

  When the looseness of the belt 16 or the link chain 16a is within a healthy range, the elapsed time (T0) from when the current value is stabilized as the rotation in the no-load state is short, and the current value due to the applied rotation The rise of is occurring. This is because the looseness generated in the belt 16 and the link chain 16a is eliminated at the stage where the current value is stabilized by the rotation in the no-load state, and the tension on the pull-in side of the drive wheel 12 is generated, so the load increases. This is because phenomena such as a decrease in the number of revolutions and an increase in supply current have occurred.

  On the other hand, when the slack of the belt 16 or the link chain 16a is large, the elapsed time (T1) after the current value is stabilized as rotation in the no-load state is long, and the current value increases due to the applied rotation. It can be read that the inclination indicating the inclination is steep compared to the case where the slack of the belt 16 or the link chain 16a is healthy. This is because it takes a long time to reverse the looseness that occurs in the belt 16 and the link chain 16a after the drive wheel 12 is rotated in the reverse direction. Will occur. For this reason, in order to improve the rotation speed of the drive means 20, the supply current value increases rapidly.

  From these events, the degree of looseness of the belt 16 and the link chain 16a can be calculated based on the difference (t) between T1 and T0, and the soundness of the degree of looseness can be determined. Note that the difference t also varies depending on the rotational speed (N) of the driving means 20. Therefore, when the rotational speed (N) is not constant (when the designated rotational speed (N) changes according to the specification), the difference is expressed as a ratio obtained by dividing T1 and T0 by the rotational speed (N). Anyway.

  As an example, the state in which the current value at the time of no-load rotation is stable can be the time when the slope of the graph indicating the increase in current becomes substantially zero. Further, the transition to the applied rotation can be performed when the inclination of the graph again occurs after the inclination of the graph becomes almost zero, and T1 and T0 are detected based on these. It ’s fine.

  The relationship between the difference (t) and the looseness is desirably obtained in advance by experiments. The relationship between the difference (t) and the looseness is sequentially recorded to create a database, and this is recorded in the storage unit, so that the difference (t) that can be read from the graph shown in FIG. 4 is compared with the database 26a (see FIG. 1). This is because it is possible to derive a corresponding degree of looseness (amount of looseness).

  Further, in the detection device 10 according to the embodiment, the threshold value of the degree of looseness is set in advance, and the threshold value is compared with the derived degree of looseness, and the belt 16 or the link chain 16a that is the detection target is loosened. It is also possible to determine whether or not it is healthy.

  The determination of the amount of looseness can also be made from the waveform of the current value supplied to the driving means 20 itself. As described above, in the drive system in which the amount of looseness has increased, after the drive wheel 12 is rotated in the reverse direction, the rise of the current value that occurs when shifting from no-load rotation to applied rotation becomes steep, and during steady operation Supply exceeding the supplied current value may be made. For this reason, the current waveform of the supply current value may be displayed on the display means 28 and the amount of looseness may be determined based on the waveform. There are various determination methods. For example, the relation between current waveform and looseness is made into a database, and approximate waveform data is obtained from the databased waveform data and the amount of looseness associated with this waveform data is derived, as well as past experimental data and Judgment can also be made based on experience values.

  The detection device 10 having such a configuration can be applied to the detection of the looseness of a belt in a general belt conveyor, and as shown in FIG. 5, the driving wheel 12 and the driven wheel 14 are arranged vertically. The present invention can also be applied to other dust removing devices 30.

  The dust removing device 30 shown in FIG. 5 has a pair of driving wheels 12 (driving sprockets) arranged at the upper part of a water channel with water flow and a driven wheel 14 (driven sprocket) arranged at the lower part of the water channel, in accordance with the width of the water channel. In this configuration, a plurality of dust removal filters 32 are continuously bridged between a pair of link chains 16a wound around each drive wheel 12 and each driven wheel 14. Also in the dust removing device 30 having such a basic configuration, the link chain 16a on the delivery side of the drive wheel 12 is bent. For this reason, when the looseness of the link chain 16a becomes large, the deflection generated on the delivery side also becomes large. Therefore, when the drive wheel 12 is rotated in the reverse direction, a deviation occurs in the timing when the current supplied to the drive means 20 shifts from the supply current value during no-load rotation to the supply current value during load rotation. . For this reason, it becomes possible to apply the looseness detection method like the said embodiment.

  In the above embodiment, the specific application of the endless belt looseness detection device and method according to the present invention has been described with reference to the belt conveyor and the dust removal device 30. However, the endless belt looseness detection method according to the present invention includes the drive wheel 12 and the driven wheel 14 (the number of the driven wheels may be plural), and between the drive wheel 12 and the driven wheel 14. The belt 16 or the link chain 16a that is wound around and rotated, or any element that is conceptually included in the belt or the link chain can be applied.

DESCRIPTION OF SYMBOLS 10 ......... Detection device, 12 ......... Driving wheel, 12a ......... Rotating shaft, 14 ......... Driving wheel, 16 ...... Belt, 16a ......... Link chain, 18 ......... Transmission, 20 ... ...... Drive means, 22 ...... Control means, 24 ...... Calculation section, 26 ...... Storage section, 26 a ...... Database, 28 ...... Display means, 30 ...... Dust removal device, 32 ...... filter.

Claims (4)

A device for detecting looseness of an endless belt or an endless link chain wound around a driving wheel and a driven wheel,
Drive means for rotating the drive wheel;
Control means for supplying a command signal for forward rotation and reverse rotation to the drive means, and for supplying a current for obtaining a predetermined rotational speed,
The control means receives feedback of the rotational speed of the driving means, compares the feedback rotational speed with the predetermined rotational speed, and increases the current value to obtain the feedback rotational speed Or, when the reverse rotation command signal is given from the control means, the value of the current supplied to the drive means shifts from the current value during no-load rotation to the current value during load rotation. An endless belt and endless link chain looseness detecting device, comprising: a calculation unit that calculates the degree of looseness of the endless belt and the endless link chain based on the time until the end.   The calculation of the degree of looseness of the endless belt or the endless link chain is based on the database that shows the relationship between the transition time from the current value during the no-load rotation to the current value during the applied rotation and the degree of looseness. The endless belt and endless link chain slack detection apparatus according to claim 1, wherein the calculation unit derives based on the time recorded in the database. A method for detecting looseness of an endless belt or an endless link chain wound around a driving wheel and a driven wheel,
From the state where the drive wheel is rotated forward, it is rotated backward,
Looseness of the endless belt and the endless link chain, which derives the degree of looseness of the endless belt and the endless link chain based on the time until the change of the drive current value caused by the change of the load generated after reverse rotation Detection method.   The looseness of the endless belt or the endless link chain is derived from a database that associates the time until the change of the drive current value with the looseness of the endless belt or the endless link chain. 4. A method for detecting looseness of an endless belt and an endless link chain according to 3.