JP2017146227A - Wheel wear detection method, wheel wear detection device, and overhead crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel wear detection method, a wheel wear detection device, and an overhead crane which detect wear of a traveling wheel of the overhead crane by a non-contact range meter.SOLUTION: A wheel wear detection method for detecting wear of a traveling wheel of an overhead crane includes: measuring a traveling-direction distance of the overhead crane at both ends in a traverse direction of the overhead crane by laser range meters which are arranged at both ends in the traverse direction on the overhead crane, while the overhead crane travels (step S2); and detecting the wear of the traveling wheel from a difference A between measurement values at both ends in the traverse direction (steps S5, S7).SELECTED DRAWING: Figure 4

Description

  The present invention relates to a wheel wear detection method, a wheel wear detection device, and an overhead crane.

  Conventionally, as a method of detecting wheel wear of an overhead crane, a method of directly measuring the wheel diameter using a measuring instrument such as a measure has been performed.

  Patent Document 1 discloses a method of measuring the amount of wear of a wheel using a laser distance meter. The laser distance meter is attached to the frame of the vehicle body and projects laser light toward the floor. Therefore, after the vehicle is moved to a horizontal floor (measurement place), the distance to the floor is measured by the laser distance meter at the measurement place. And when detecting the wear of the wheel, measure the distance when the wheel is new, store the measured value at the time of the new in the storage circuit, measure the distance again after a certain amount of time, The measured value is compared with the measured value at the time of a new article to detect the amount of wheel wear.

JP 2008-175664 A

  However, in the configuration described in Patent Document 1, when a traveling wheel of an overhead crane is targeted, a horizontal plane place must be provided on the traveling floor surface of the overhead crane. For example, a part of the traveling floor of the gantry that supports the overhead crane is modified to a horizontal floor that has high level of brightness and reflects laser light well, or a laser beam reflector is newly installed on the floor. It becomes necessary to do. Furthermore, since the reflecting surface is also a floor surface, dust or the like accumulates with the passage of time, making it difficult to reflect the laser light and making measurement impossible. In particular, since the overhead crane travels on a rail, unlike the trackless traveling vehicle of Patent Document 1, there is a problem that the change in rail height due to wear on the rail surface affects the measurement. . In addition, when the horizontal floor or reflector is only part of the traveling range of the overhead crane, it can be measured only on the horizontal floor or reflector, and continuous measurement over the entire traveling range is not possible. There is a problem.

  The present invention has been made in view of the above circumstances, and a wheel wear detection method, a wheel wear detection device, and an overhead crane that can detect the wear of a traveling wheel of an overhead crane with a non-contact distance meter. The purpose is to provide.

  The present invention relates to a wheel wear detection method for detecting wear of a traveling wheel of an overhead crane, wherein the overhead crane travels by means of a non-contact distance meter disposed on both ends in a transverse direction on the machine of the overhead crane. A position detection step for detecting the traveling direction position of the overhead crane at both ends in the transverse direction, and a wear detection for detecting the wear of the traveling wheel from the difference in each traveling direction position detected in the position detection step. And a step.

  In the above invention, the position detecting step is arranged on the building wall at a position facing the first laser distance meter in the traveling direction and a first laser distance meter arranged on one end side in the transverse direction as the distance meter. A first measuring step of measuring a traveling direction distance between the first laser rangefinder and the first reflecting plate on the one end side while the overhead crane is traveling by the first reflecting plate; The second laser distance meter disposed on the other end side in the traversing direction as the distance meter, and the second reflector disposed on the building wall at a position facing the second laser distance meter in the traveling direction, A second measuring step of measuring a traveling direction distance between the second laser rangefinder and the second reflector on the other end side while the overhead crane is traveling, and the wear detecting step includes: The first measurement The difference between the travel direction distance measured in step and the travel direction distance measured in the second measurement step is calculated, and whether or not the difference changes according to the traveling of the overhead crane. Preferably, the method includes a step of detecting whether or not the traveling wheel is worn.

  In the above invention, while the overhead crane is traveling, the difference is compared with a predetermined crane skew limit value, and when the difference is equal to or greater than the limit value, the overhead crane stops traveling. Preferably, the method further includes:

  The present invention relates to a wheel wear detection device for detecting wear of a traveling wheel of an overhead crane, a pair of non-contact type distance meters disposed on both ends in the transverse direction on the machine of the overhead crane, and each distance meter A control device to which the measured value of the overhead crane is input, and the control device detects a traveling direction position of the overhead crane on both ends in the transverse direction based on the measured value input from each distance meter. And a wear detecting means for detecting wear of the traveling wheel from the difference in each traveling direction position detected by the position detecting means.

  In the above invention, the distance meter includes a first laser distance meter disposed on one end side in the traversing direction and a second laser distance meter disposed on the other end side in the traversing direction, A first reflector disposed on the building wall at a position facing the first laser distance meter; and a second reflector disposed on the building wall at a position facing the second laser distance meter in the traveling direction. The position detecting means measures a traveling direction distance between the first laser rangefinder and the first reflector on one end side in the transverse direction while the overhead crane is traveling; and A measuring unit that measures a traveling direction distance between the second laser distance meter and the second reflector on the other end side in the traversing direction, wherein the wear detecting unit is measured by the first laser distance meter. The travel direction distance and the second laser Calculating a difference between the running direction distance measured with a release meter, the difference is, it is preferable for detecting the presence or absence of wear of the road wheels on whether changes in accordance with the traveling of the overhead crane.

  In the above invention, the control device compares the difference with a predetermined crane skew limit value while the overhead crane is traveling, and if the difference exceeds the limit value, the control device travels. It is preferable to further have means for stopping the overhead crane inside.

  The overhead crane which concerns on this invention has the wheel abrasion detection apparatus of the said invention, It is characterized by the above-mentioned.

  In the present invention, the non-contact type distance meter installed on both ends in the transverse direction on the machine of the overhead crane, the difference between the traveling direction positions of the overhead crane on both ends in the transverse direction, Wear can be detected.

Drawing 1 is a schematic diagram showing an overhead crane of an embodiment. FIG. 2 is a schematic diagram illustrating a case where the overhead crane illustrated in FIG. 1 is viewed from above. FIG. 3 is a functional block diagram schematically showing the control device. FIG. 4 is a flowchart showing a wheel wear detection method.

  Hereinafter, a wheel wear detection method, a wheel wear detection device, and an overhead crane according to an embodiment of the present invention will be specifically described with reference to the drawings.

[1. Overhead traveling crane]
Drawing 1 is a schematic diagram showing an overhead crane of an embodiment. FIG. 2 is a schematic diagram illustrating a case where the overhead crane illustrated in FIG. 1 is viewed from above.

  The overhead crane 10 is, for example, a ladle crane used to transport a ladle (a ladle) in a steel factory, and travel rails 22 extending in parallel along both side walls 21 and 21 of the building 20. Drive on the 22nd. The traveling rail 22 is laid on a pedestal portion 21 a formed integrally with the side wall 21. The gantry 21a has a structure that protrudes from the side wall 21 toward the other side wall 21 at a predetermined height. The traveling wheels 11 of the overhead crane 10 are located on the traveling rails 22.

  The overhead crane 10 includes a traveling wheel 11, a crane girder 12, and a trolley 13. As the traveling wheel 11 rolls on the traveling rail 22, the overhead crane 10 travels (moves in the traveling direction). The traveling direction is a direction parallel to the direction in which the traveling rail 22 extends. The trolley 13 traverses the crane girder 12 (moves in the transverse direction), and is provided with a hoisting device (not shown). Since the hoisting device winds up the hook block 14 suspended from the trolley 13, the hook block 14 is traversed by the trolley 13.

  The arrangement of each component will be described using front, rear, left and right for convenience of explanation. The right side of FIGS. 1 and 2 is referred to as “front in the traveling direction”, and the left side of FIGS. Further, the upper side of FIG. 2 is “left side with respect to the traveling direction”, and the lower side of FIG.

[2. Wheel wear detection device]
The wheel wear detection device 100 includes two laser distance meters 31, 32, two reflecting plates 33, 34, and a control device 40 described later. The control device 40 will be described later with reference to FIG.

  Each of the laser distance meters 31 and 32 is a non-contact type distance meter, and is disposed on both ends of the transverse direction on the machine of the overhead crane 10. For example, as shown in FIGS. 1 and 2, each of the laser distance meters 31 and 32 is fixed at a predetermined height by a support member protruding upward in the height direction from the crane girder 12. While the overhead crane 10 is traveling, the laser distance meters 31 and 32 and the crane girder 12 move integrally in the traveling direction.

  Specifically, the laser distance meters 31 and 32 are disposed on the crane girder 12 and directly above the traveling wheels 11 and 11 on both sides in the transverse direction. The first laser rangefinder 31 is installed on one end side in the traversing direction and is provided directly above the left traveling wheel 11 with respect to the front in the traveling direction. The second laser distance meter 32 is disposed on the other end side in the transverse direction, that is, on the opposite side to the first laser distance meter 31, and is provided directly above the right traveling wheel 11 with respect to the front in the traveling direction. It has been. More specifically, in the example shown in FIG. 1, the overhead crane 10 has four traveling wheels 11 on the front, rear, left, and right, and each laser distance meter 31, 32 has the front traveling wheel 11 in the traveling direction. It is placed directly above. Since the front traveling wheel 11 and the laser distance meters 31 and 32 are provided at positions overlapping in the height direction (vertical direction), FIG. 2 shows the front traveling wheels 11 on both the left and right sides. Is not shown.

  The two reflecting plates 33 and 34 are disposed on the wall 23 in the traveling direction of the building 20. The reflecting plates 33 and 34 are for reflecting the laser light projected by the laser distance meters 31 and 32 to the laser distance meters 31 and 32. The first reflector 33 is for the first laser distance meter 31 and is disposed on the wall 23 at a position facing the first laser distance meter 31 in the traveling direction. The second reflector 34 is for the second laser distance meter 32 and is disposed on the wall 23 at a position facing the second laser distance meter 32 in the traveling direction.

  Specifically, the arrangement of the first reflector 33 is the same position as the first laser rangefinder 31 in the transverse direction and the height direction. The second reflector 34 is disposed at the same position as the second laser distance meter 32 in the transverse direction and the height direction. In short, each of the reflectors 33 and 34 is configured such that the laser light projected from the laser distance meters 31 and 32 is incident on the reflecting surface horizontally, and the laser light reflected by the reflecting surfaces is reflected on the laser distance meters 31 and 32. Is arranged to return. Furthermore, the reflecting surfaces of the reflecting plates 33 and 34 are formed as vertical surfaces that spread with a predetermined width along the height direction and the transverse direction of the building 20.

  In the wheel wear detection device 100, laser light is projected from the first laser distance meter 31, and the time until the first laser distance meter 31 receives the reflected light that is reflected by the first reflector 33 and returned is measured. Then, the distance in the traveling direction between the first laser rangefinder 31 and the first reflector 33 is measured. The wheel wear detection device 100 detects the traveling direction position of the overhead crane 10 on the first laser distance meter 31 side from the measured value. Similarly, for the second laser distance meter 32, the wheel wear detection device 100 detects the traveling direction position of the overhead crane 10 on the second laser distance meter 32 side from the measurement value of the second laser distance meter 32. Specifically, the wheel wear detection device 100 projects laser light from the second laser distance meter 32, and the second laser distance meter 32 receives reflected light that is reflected by the second reflector 34 and returned. Is measured, and the traveling direction distance between the second laser distance meter 32 and the second reflector 34 is measured. Further, each laser distance meter 31, 32 projects laser light in a direction parallel to the traveling rail 22, that is, each reflection, even when the overhead crane 10 is skewed as described later. Laser light along the traveling direction can be projected toward the plates 33 and 34.

  In the wheel wear detection device 100, the measurement data of the laser distance meters 31 and 32 is output to the control device 40.

  FIG. 3 is a functional block diagram schematically showing the control device 40. The control device 40 is an electronic control device, and detects wear of the traveling wheels 11 in the overhead crane 10 based on measurement values (distance data) input from the laser distance meters 31 and 32. Specifically, the control device 40 includes a position detection unit 41, a wear detection unit 42, and a stop unit 43.

  The position detection unit 41 detects the traveling direction position on both ends of the overhead crane 10 in the transverse direction. The position detection unit 41 includes a first measurement unit 41a and a second measurement unit 41b.

  The first measurement unit 41 a measures the travel direction distance from the first reflector 33 by the first laser distance meter 31. Since this travel direction distance is distance data representing the travel direction position of the first laser rangefinder 31, the position detection unit 41 uses the measured value (first distance data) of the first laser rangefinder 31 in the traverse direction. The traveling direction position of the overhead crane 10 on one end side is detected. In addition, the second measuring unit 41 b measures the travel direction distance from the second reflector 34 by the second laser distance meter 32. Since this travel direction distance is distance data representing the travel direction position of the second laser distance meter 32, the position detection unit 41 uses the measured value (second distance data) of the second laser distance meter 32 in the transverse direction. The traveling direction position of the overhead crane 10 on the other end side is detected.

  The wear detection unit 42 detects whether or not the traveling wheels 11 of the overhead crane 10 are worn. The wear detection unit 42 includes a calculation unit 42a and a determination unit 42b.

  The calculation unit 42a calculates the difference A between the measurement values of the laser distance meters 31 and 32. The determination unit 42 b determines whether or not the difference A increases or decreases in accordance with the traveling of the overhead crane 10. In short, the wear detection unit 42 determines the wear of the traveling wheel 11 depending on whether or not the absolute value of the difference A between the measured values of the laser distance meters 31 and 32 changes during the traveling of the overhead crane 10. Detect the presence or absence. That is, the wear detection unit 42 is configured to detect the wear of the traveling wheel 11 from the difference in the traveling direction position detected by the laser distance meters 31 and 32.

  The stop unit 43 stops the overhead crane 10 when a predetermined stop condition is satisfied due to wear of the traveling wheels 11. In this case, a stop signal is output from the control device 40 to the overhead crane 10.

[3. Wheel wear detection method]
FIG. 4 is a flowchart showing a wheel wear detection method. The processing flow shown in FIG. 4 is performed by the wheel wear detection apparatus 100 described above.

  As shown in FIG. 4, first, the overhead crane 10 starts to travel (step S1). In this wheel wear detection method, the overhead crane 10 is traveling as a precondition. While the overhead crane 10 is traveling, the distance in the traveling direction of the overhead crane 10 at both ends in the transverse direction is measured by the laser distance meters 31 and 32 (step S2).

  Each measurement value (distance data) measured in step S2 is input to the control device 40 in real time while the overhead crane 10 is traveling. The position detection unit 41 of the control device 40 detects the traveling direction position of the overhead crane 10 at both ends in the transverse direction based on each input distance data. In step S2, the position detection unit 41 (each measurement unit 41a, 41b) may measure the travel direction distance by controlling each laser distance meter 31, 32.

  Further, the wear detection unit 42 of the control device 40 calculates a difference A between the first distance data measured by the first laser distance meter 31 and the second distance data measured by the second laser distance meter 32 (step S3). ). In step S <b> 3, the calculation unit 42 a of the wear detection unit 42 subtracts the second distance data of the second laser distance meter 32 from the first distance data of the first laser distance meter 31 and calculates the difference A.

  Then, the determination unit 42b of the wear detection unit 42 determines whether or not the difference A calculated in step S3 increases in the positive direction (step S4). The increase in the positive direction represents a change that occurs when the second distance data is smaller than the first distance data.

  When the difference A increases in the positive direction and the determination in step S4 is affirmative, the wear detection unit 42 determines that the traveling wheel 11 on the second laser distance meter 32 side is worn ( Step S5). This is because the amount of wear of the traveling wheel 11 on the second laser distance meter 32 side (the other end side in the traversing direction) is equal to the wear amount of the traveling wheel 11 on the first laser distance meter 31 side (one end side in the traversing direction). If the rotational speeds of the traveling wheels 11 coincide with each other, the second distance data indicating the traveling direction position on the second laser rangefinder 32 side is on the first laser rangefinder 31 side. This is because the value is smaller than the first distance data indicating the traveling direction position. Therefore, the direction in which the difference A changes in accordance with the traveling of the overhead crane 10 is an increase in the plus direction. And the control apparatus 40 complete | finishes this process flow after step S5.

  On the other hand, when the difference A is determined not to increase in the positive direction and a negative determination is made in step S4, the determination unit 42b determines whether or not the difference A increases in the negative direction (step S6). ). The increase in the minus direction represents a change that occurs when the first distance data is smaller than the second distance data.

  If the difference A increases in the negative direction and the determination in step S6 is affirmative, the wear detection unit 42 determines that the traveling wheel 11 on the first laser rangefinder 31 side is worn ( Step S7). This is because the wear amount of the traveling wheel 11 on the first laser distance meter 31 side (one end side in the traversing direction) is equal to the wear amount of the traveling wheel 11 on the second laser distance meter 32 side (the other end side in the traversing direction). If the rotational speed of each traveling wheel 11 is equal, the first distance data indicating the traveling direction position on the first laser distance meter 31 side is the second laser distance meter 32 side. This is because the value is smaller than the second distance data indicating the traveling direction position. Therefore, the direction in which the difference A changes in accordance with the traveling of the overhead crane 10 increases in the minus direction. And the control apparatus 40 complete | finishes this process flow after step S7.

  If the negative determination is made in step S6 because the difference A does not increase in the negative direction, the control device 40 ends this processing flow. The case in which the result is negative in step S6 includes the case where there is no wear on the traveling wheel 11 and the case where there is no wheel wear that causes crane skew.

  Although not shown in FIG. 4, the control device 40 can execute a process of comparing the difference A with the limit value of the crane skew on the machine dimension. Specifically, the determination unit 42b of the control device 40 determines whether or not the difference A is equal to or greater than a predetermined limit value. For example, the determination unit 42b is configured to compare the difference A with the limit value after performing the above-described step S5 or after performing step S7. When the determination unit 42b determines that the difference A is equal to or greater than the limit value, the stop unit 43 of the control device 40 executes stop control of the overhead crane 10 and determines that the stop condition is satisfied, and is traveling. The overhead crane 10 is stopped. As a result, when large wear occurs on the traveling wheel 11 that may cause the overhead crane 10 to run obliquely and derail from the traveling rail 22, the overhead crane 10 is removed by the stop control of the stopping portion 43. Prevents damage to equipment such as wheels.

  As described above, in the present embodiment, the laser distance meters 31 and 32 are installed on both ends in the transverse direction on the machine of the overhead crane 10, and the laser distance meters 31 and 32 are provided on the wall 23 in the traveling direction of the building 20. Reflectors 33 and 34 are installed. Therefore, the traveling direction distance of the overhead crane 10 can be individually measured at both ends in the transverse direction, and the traveling direction positions of the first laser distance meter 31 side and the second laser distance meter 32 side are compared. Can do. Thereby, it becomes possible to detect which of the traveling wheel 11 on the first laser distance meter 31 side or the traveling wheel 11 on the second laser distance meter 32 side is worn.

  In addition, since it is not necessary to provide a reflector on the gantry 21a, which is the traveling floor of the overhead crane 10, dust or the like accumulates on the reflecting surface as the floor over time, making it difficult for laser light to be reflected. Measurement is not impossible. Further, since the distance in the traveling direction is measured by the laser distance meters 31 and 32, even if the rail height changes due to wear of the rail surface of the traveling rail 22, the change is used to measure the distance in the traveling direction. No effect. In addition, it is not necessary to make major modifications to the equipment such as providing reflectors over the entire area of the overhead crane 10 in which the overhead crane 10 can travel, and to increase the new additional cost. In short, the wheel wear detection device 100 having a simple equipment structure can be realized.

  In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the objective of this invention, it can change suitably.

  For example, in the above-described embodiment, the configuration in which the traveling direction positions of the laser distance meters 31 and 32 are arranged directly above the traveling wheels 11 on the front side is described, but the present invention is not limited to this. Assuming that all the new traveling wheels 11 are located on the traveling rail 22, it is only necessary that the laser distance meters 31 and 32 are disposed at the same traveling direction position. Therefore, the arrangement of the laser distance meters 31 and 32 may be directly above the traveling wheels 11 on the rear side in the traveling direction, or may be directly above the traveling rails 22 and 22. Furthermore, the arrangement of the laser distance meters 31 and 32 in the transverse direction is not limited to the above-described example. That is, the arrangement in the traversing direction may be on the inner side (trolley 13 side) than each traveling wheel 11 or on the outer side (side wall 21 side) than the traveling wheel 11 (travel rail 22).

  Moreover, although each reflecting plate 33 and 34 demonstrated the example fixed to the wall 23 ahead of the running direction of the building 20, it is not limited to this. For example, the reflectors 33 and 34 may be provided closer to the overhead crane 10 than the wall 23. The reflecting plates 33 and 34 are preferably arranged and fixed on one side of the traveling direction with respect to the laser distance meters 31 and 32 so that the reflecting surfaces are not displaced.

  Further, the wear detection unit 42 of the control device 40 calculates the difference by subtracting the first distance data measured by the first laser distance meter 31 from the second distance data measured by the second laser distance meter 32. It may be configured as follows. In the wheel wear detection device and the wheel wear detection method using this difference, the description in the case of using the difference A described above is rewritten so that the relationship between both sides in the transverse direction is reversed.

  Moreover, in the specific example mentioned above, although the overhead crane 10, the building 20, and the wheel wear detection apparatus 100 were distinguished and demonstrated, it can be paraphrased that the overhead crane 10 is the structure containing the building 20 and the wheel wear detection apparatus 100. Is possible.

DESCRIPTION OF SYMBOLS 10 Overhead crane 11 Traveling wheel 12 Crane girder 20 Building 21 Side wall 22 Traveling rail 23 Wall 31 First laser rangefinder 32 Second laser rangefinder 33 First reflector 34 Second reflector 40 Controller 41 Position detector 42 Wear detection unit 43 Stop unit 100 Wheel wear detection device

Claims (7)

In the wheel wear detection method for detecting the wear of the traveling wheel of the overhead crane,
Position detection for detecting the traveling direction position of the overhead crane at both ends in the transverse direction while the overhead crane is traveling by non-contact distance meters arranged on both ends in the transverse direction on the machine of the overhead crane Steps,
A wheel wear detection method, comprising: a wear detection step of detecting wear of the traveling wheel from a difference in each traveling direction position detected in the position detection step. The position detecting step includes
The ceiling is formed by a first laser distance meter disposed as one of the distance meters on one side in the transverse direction and a first reflector disposed on a building wall at a position facing the first laser distance meter in the traveling direction. A first measuring step of measuring a traveling direction distance between the first laser rangefinder and the first reflector on the one end side while the crane is traveling;
The second laser distance meter disposed on the other end side in the traversing direction as the distance meter, and the second reflector disposed on the building wall at a position facing the second laser distance meter in the traveling direction, A second measuring step of measuring a traveling direction distance between the second laser rangefinder and the second reflector on the other end side while the overhead crane is traveling,
The wear detection step includes
Calculate a difference between the travel direction distance measured in the first measurement step and the travel direction distance measured in the second measurement step, and whether the difference changes according to the traveling of the overhead crane. The wheel wear detection method according to claim 1, further comprising a step of detecting the presence or absence of wear of the traveling wheel depending on whether or not. When the overhead crane is traveling, the difference is compared with a predetermined limit value of the skew of the crane, and when the difference is equal to or greater than the limit value, the traveling of the overhead crane is stopped. The wheel wear detection method according to claim 2, further comprising: In the wheel wear detection device for detecting the wear of the traveling wheel of the overhead crane,
A pair of non-contact distance meters arranged on both sides in the transverse direction on the machine of the overhead crane;
A control device to which the measured value of each distance meter is input,
The controller is
Based on the measurement value input from each distance meter, position detection means for detecting the traveling direction position of the overhead crane on both ends in the transverse direction;
A wheel wear detection device, comprising: wear detection means for detecting wear of the running wheel from a difference in each traveling direction position detected by the position detection means. The distance meter
A first laser rangefinder disposed on one end side in the transverse direction;
A second laser rangefinder disposed on the other end side in the transverse direction,
A first reflector disposed on a building wall at a position facing the first laser distance meter in a traveling direction;
A second reflector disposed on the building wall at a position facing the second laser rangefinder in the traveling direction;
The position detecting means includes
While the overhead crane is traveling, the distance in the traveling direction between the first laser rangefinder and the first reflector on one end side in the traversing direction is measured, and on the other end side in the traversing direction. Measuring means for measuring a traveling direction distance between the second laser distance meter and the second reflector;
The wear detection means includes
The difference between the travel direction distance measured with the first laser distance meter and the travel direction distance measured with the second laser distance meter is calculated, and whether the difference changes in accordance with the traveling of the overhead crane. The wheel wear detection device according to claim 4, wherein the presence or absence of wear of the traveling wheel is detected based on whether or not the wheel is worn. The control device compares the difference with a predetermined crane skew limit value while the overhead crane is traveling, and if the difference is greater than or equal to the limit value, the ceiling during traveling is compared. The wheel wear detection device according to claim 5, further comprising means for stopping the crane.   An overhead crane having the wheel wear detection device according to any one of claims 4 to 6.

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