Carrying device

Abstract

The conveyance device includes a traveling trolley, a main column, a lifting unit, and a control unit. The walking trolley is provided with a plurality of driving units, and each driving unit is provided with a wheel, a motor for driving the wheel, and a slip detection part for detecting slip of the wheel. When the control unit accelerates at least the traveling trolley, the control unit stops the traveling trolley (S4) if two or more of the plurality of slip detection units detect a slip of a predetermined amount or more (YES in S2).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a conveyance device for conveying an article. BACKGROUND

[0002] In the past, in an automated warehouse, a stacker crane has been used to convey an article. With regard to the stacker crane, it is known that the wheels of a traveling carriage thereof can slip (for example, see Patent Literature 1).

[0003] (Prior Art Documents)

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2008-254912 SUMMARY

[0005] (Problems to be Solved by the Invention)

[0006] However, there is a problem in that, for example, when the traveling carriage is to be stopped in the event that one of the front wheels or the rear wheels thereof slips, the efficiency of conveying the article by the traveling carriage is reduced.

[0007] An object of one aspect of the present disclosure is to provide a conveyance device capable of suppressing a reduction in the efficiency of conveying an article by a traveling carriage.

[0008] (Technical Means for Solving the Problems)

[0009] To solve the above problem, a conveyance device according to one aspect of the present disclosure includes a traveling carriage that travels along a track, a main column that is erected on the traveling carriage, a lifting section that holds an article and is lifted along the main column, and a control section. The traveling carriage has a plurality of drive units each including a wheel that rolls on the track, a motor that drives the wheel, and a slip detection section that detects a slip of the wheel. In a state in which the traveling carriage is accelerated by the control section, when two or more of the slip detection sections detect the slip of the wheel by a prescribed amount or more, the control section stops the traveling carriage.

[0010] (Effects of the Invention)

[0011] According to one aspect of the present disclosure, it is possible to suppress a reduction in the efficiency of conveying an article by a traveling carriage. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a front view of a stacker crane that is an embodiment of the present disclosure.

[0013] Figure 2 is a block diagram of an electric control scheme of the stacker crane in the embodiment.

[0014] Figure 3is a block diagram of an electric control scheme of the travel control section in the embodiment.

[0015] Figure 4 is a flowchart of the slip detection processing by the control device in the embodiment.

[0016] Figure 5 is a flowchart of the sensor abnormality detection processing by the travel control section in the embodiment.

[0017] <Legend>

[0018] 1stacker robot

[0019] 10traveling trolley

[0020] 11main column

[0021] 12lifting section

[0022] 13transfer device

[0023] 21a first wheel

[0024] 21b second wheel

[0025] 22lifting motor

[0026] 24first reporting section

[0027] 25second reporting section

[0028] 26lifting sensor

[0029] 27a first encoder

[0030] 27b second encoder

[0031] 28a first travel motor

[0032] 28b second travel motor

[0033] 29travel sensor

[0034] 30control device

[0035] 31travel control section

[0036] 32lifting control section

[0037] 33transfer control section

[0038] 34first slip detection section

[0039] 35second slip detection section

[0040] 41first drive unit

[0041] 42second drive unit DETAILED DESCRIPTION

[0042] Hereinafter, referring to Figures 1-5 Embodiments of the present disclosure are described.

[0043] [Outline configuration of stacking robot]

[0044] Figure 1 is a front view of a stacking robot 1. The stacking robot 1 is an example of a carrying device that carries a carrying object in an automatic warehouse or the like. As Figure 1 indicated, the stacking robot 1 is provided with a traveling carriage 10, a pair of main columns 11, a lifting section 12, and a transfer device 13.

[0045] Here, for convenience of explanation, the upward and downward directions and the front and rear directions of the stacking robot 1 are defined in the directions indicated by arrows in Figure 1 the drawing. In addition, the front side of the paper is defined as the right side of the stacking robot 1, and the back side of the paper is defined as the left side of the stacking robot 1. The upward and downward directions of the stacking robot 1 correspond to the direction in which the lifting section 12 is lifted. The front and rear directions of the stacking robot 1 correspond to the direction in which the traveling carriage 10 travels. Figure 1 Figure 1

[0046] The traveling carriage 10 travels along a rail in the traveling direction, that is, the front and rear directions. The rail is constituted by a traveling rail R1. The traveling carriage 10 has a first wheel 21a and a second wheel 21b. The traveling carriage 10 travels on the traveling rail R1 by rotation of the first wheel 21a and the second wheel 21b. The first wheel 21a and the second wheel 21b are examples of wheels that roll on the rail.

[0047] The first wheel 21a is disposed on the front side of the traveling carriage 10. The second wheel 21b is disposed on the rear side of the traveling carriage 10. The first wheel 21a is driven by a first traveling motor 28a. The second wheel 21b is driven by a second traveling motor 28b. The first traveling motor 28a and the second traveling motor 28b are examples of motors that drive the wheels.

[0048] The pair of main columns 11 are erected on the upper portion of the traveling carriage 10. Each main column 11 is separated in the front and rear directions and extends along the upward and downward directions. Each main column 11 is constituted by a hollow member whose long side is along the upward and downward directions.

[0049] Each upper end portion of the pair of main columns 11 is connected to each other by an upper frame 14. The upper frame 14 has a guide roller 15. The guide roller 15 is guided by a guide rail R2 fixed to a ceiling (not shown). The upper frame 14 is configured to be movable in the front and rear directions while being guided by the guide rail R2.

[0050] ​​The lifting section 12 is supported by the pair of main columns 11 and is lifted up and down along the main columns 11. The lifting section 12 is supported by being suspended by the four cables 20 wound around the rotating body 23. In the front portion of the traveling car 10, a lifting motor 22 is provided. By driving the lifting motor 22 to rotate the rotating body 23 in the forward direction or the reverse direction, the cables 20 are wound in or unwound, whereby the lifting section 12 is lifted up and down along the main columns 11. Here, two lifting motors 22 can be provided in the front portion and the rear portion of the traveling car 10, respectively.

[0051] The transfer device 13 supports the lifting section 12. The transfer device 13 has a fork mechanism (not shown) for holding the load M. The transfer device 13 places the load M to a prescribed transfer position in a storage section (not shown) by advancing and retreating the fork mechanism.

[0052] The traveling car 10 has a lifting sensor 26. The lifting sensor 26 detects the position of the lifting section 12 in the up-and-down direction. The lifting sensor 26 emits laser light in the up-and-down direction against a reflection plate 26a provided on the bottom surface of the lifting section 12, and receives the light reflected from the reflection plate 26a, thereby detecting the distance to the reflection plate 26a, and thus the position of the lifting section 12 in the up-and-down direction. Here, although an example is given in which the lifting sensor 26 is a laser distance sensor, it is not limited thereto, and a bar code distance sensor system can be employed.

[0053] In addition, the traveling car 10 has a traveling sensor 29. The traveling sensor 29 is an example of a position detection section that detects the position of the traveling car 10 along the rail. The traveling sensor 29 emits laser light in the longitudinal direction of the traveling rail Rl against a reflection plate 29a provided at the end portion of the traveling rail Rl, and receives the light reflected from the reflection plate 29a, thereby detecting the distance to the reflection plate 29a, and thus the position of the traveling car 10.

[0054] [Electric control scheme of stacking robot]

[0055] Next, the electric control scheme of the stacking robot 1 will be described with reference to Figure 2 Figure 2 is a block diagram of the electric control scheme of the stacking robot 1. As Figure 2 indicated, the stacking robot 1 further includes a first reporting section 24, a second reporting section 25, a first encoder 27a, a second encoder 27b, and a control device 30.

[0056] The first reporting section 24 is a unit that informs a user of the fact that the first wheel 21a has slipped when the first slip detection section 34 detects the slip of the first wheel 21a. The first reporting section 24 has, for example, a speaker that outputs a sound, and a display that displays an error code or the like. ​

[0057] The second reporting section 25 is a section that informs a user of the fact that the second wheel 21b has slipped when the second slip detection section 35 detects the slip of the second wheel 21b. The second reporting section 25 has, for example, a speaker that outputs a sound, and a display that displays an error code or the like.

[0058] The first encoder 27a is, for example, a rotor encoder that is disposed in the vicinity of the first traveling motor 28a to detect the number of rotations of the first traveling motor 28a. The first encoder 27a outputs a signal corresponding to the number of rotations of the first traveling motor 28a to the first slip detection section 34.

[0059] The second encoder 27b is, for example, a rotor encoder that is disposed in the vicinity of the second traveling motor 28b to detect the number of rotations of the second traveling motor 28b. The second encoder 27b outputs a signal corresponding to the number of rotations of the second traveling motor 28b to the second slip detection section 35.

[0060] The control device 30 has a traveling control section 31, a lifting control section 32, a transfer control section 33, a first slip detection section 34, and a second slip detection section 35, and controls the operation of each section of the stacker crane 1.

[0061] The traveling control section 31 is an example of a control section that controls the traveling operation of the traveling car 10. The traveling control section 31 controls the driving of the first traveling motor 28a and the second traveling motor 28b based on the detection result of the traveling sensor 29, thereby controlling the traveling operation of the traveling car 10.

[0062] The lifting control section 32 controls the driving of the lifting motor 22 based on the detection result of the lifting sensor 26, thereby controlling the lifting operation of the lifting section 12, and moving the transfer device 13 in the up-and-down direction to a desired stop position.

[0063] The transfer control section 33 controls the transfer operation of the transfer device 13 by controlling the fork mechanism. In this way, the control device 30 controls the traveling operation of the traveling car 10, the lifting operation of the lifting section 12, and the transfer operation of the transfer device 13, thereby carrying the carried object M into the storage section or carrying the carried object M out of the storage section.

[0064] The first slip detection section 34 detects the slip of the first wheel 21a based on the number of rotations of the first traveling motor 28a detected by the first encoder 27a, and the amount of change in the position of the traveling car 10 in the traveling direction detected by the traveling sensor 29.

[0065] The second slip detection unit 35 detects slip of the second wheel 21 b based on the rotation speed of the second travel motor 28 b detected by the second encoder 27 b and the position change amount of the travel vehicle 10 in the travel direction detected by the travel sensor 29 .

[0066] The first wheel 21a, the first reporting unit 24, the first encoder 27a, the first travel motor 28a, and the first slip detector 34 constitute a first drive unit 41. The second wheel 21b, the second reporting unit 25, the second encoder 27b, the second travel motor 28b, and the second slip detector 35 constitute a second drive unit 42. The first wheel 21a of the first drive unit 41 and the second wheel 21b of the second drive unit 42 are arranged at different positions along the travel direction of the travel vehicle 10.

[0067] [Electronic control solution for the walking control unit]

[0068] Next, refer to Figure 3 The electrical control scheme of the travel control unit 31 will be described in detail. Figure 3 FIG. 3 is a block diagram of the electric control scheme of the walking control unit 31. Figure 3 As shown, the travel control unit 31 includes a synchronization control unit 36 ​​, a first servo amplifier 37 , and a second servo amplifier 38 .

[0069] The first slip detection unit 34 inputs an abnormality signal indicating that the first wheel 21 a has slipped to the synchronization control unit 36 ​​, and the second slip detection unit 35 inputs an abnormality signal indicating that the second wheel 21 b has slipped to the synchronization control unit 36 ​​.

[0070] The synchronous control unit 36 ​​determines the travel mode of the traveling vehicle 10 based on the distance between the position of the traveling vehicle 10 in the traveling direction detected by the traveling sensor 29 and the target stop position. The traveling mode includes acceleration, constant speed, and deceleration.

[0071] The synchronous control unit 36 ​​sends travel speed command information indicating a target travel speed corresponding to the travel mode to the first servo amplifier 37. The first servo amplifier 37 operates the first travel motor 28a based on the difference between the travel speed determined from the change per unit time of the travel position detected by the travel sensor 29 and the target travel speed from the synchronous control unit 36.

[0072] The first servo amplifier 37 obtains a torque command value that makes the difference between the travel speed and the target travel speed zero, and supplies a current corresponding to the torque command value to the first travel motor 28a, thereby controlling the rotation of the first travel motor 28a.

[0073] The first servo amplifier 37 also transmits the obtained torque command value to the second servo amplifier 38. Based on the torque command value from the first servo amplifier 37, the second servo amplifier 38 supplies a current corresponding to the torque command value to the second travel motor 28b, thereby controlling the rotation of the second travel motor 28b.

[0074] [Flow of Slip Detection Processing by Control Device]

[0075] Next, refer to Figure 4 The flow of the slip detection process performed by the control device 30 will be described. Figure 4 This is a flowchart of an example of the slip detection process performed by the control device 30.

[0076] exist Figure 4 In the flowchart shown, the first slip detection unit 34 of the control device 30 first determines whether a slip of the first wheel 21a exceeding a predetermined amount is detected (S1). In step S1, the first slip detection unit 34 performs a threshold determination to determine whether the difference between the travel distance (a) of the traveling vehicle 10, calculated based on the number of revolutions of the first traveling motor 28a detected by the first encoder 27a, and the position change of the traveling vehicle 10 in the traveling direction detected by the traveling sensor 29, is greater than a predetermined threshold.

[0077] If the difference between the calculated travel distance (a) of the traveling vehicle 10 and the position change amount of the traveling vehicle 10 in the travel direction is greater than or equal to a predetermined threshold, the first slip detection unit 34 determines that the first wheel 21a has slipped by a predetermined amount or more.

[0078] The first slip detection unit 34 performs the aforementioned threshold determination each time the first travel motor 28a rotates a predetermined number of times, for example, two times. Here, the corresponding travel distance of the traveling vehicle 10 when the first travel motor 28a rotates two times is defined as L1 (mm). For example, if the difference between the travel distance L1 (mm) of the traveling vehicle 10 and the position change of the traveling vehicle 10 in the travel direction detected by the travel sensor 29 is greater than or equal to 0.4 × L1 (mm), the first slip detection unit 34 determines that the first wheel 21a has slipped by a predetermined amount or more.

[0079] This makes it possible to detect at an early stage whether the first wheel 21a has slipped by a predetermined amount or more. In addition, by appropriately setting the threshold value for the threshold determination, the occurrence of slipping of the first wheel 21a by a predetermined amount or more can be detected more quickly.

[0080] If the first slip detection section 34 does not detect the slip of the first wheel 21a by the prescribed amount (NO in S1), the process returns to step S1. On the other hand, if the first slip detection section 34 detects the slip of the first wheel 21a by the prescribed amount (YES in S1), the second slip detection section 35 determines whether the slip of the second wheel 21b by the prescribed amount is detected (S2).

[0081] In step S2, the second slip detection section 35 performs the threshold determination to determine whether the difference between the travel distance (b) of the travel car 10 calculated based on the number of rotations of the second travel motor 28b detected by the second encoder 27b and the change amount of the position of the travel car 10 in the travel direction detected by the travel sensor 29 is equal to or greater than a prescribed threshold value.

[0082] Further, if the difference between the travel distance (b) of the travel car 10 calculated and the change amount of the position of the travel car 10 in the travel direction is equal to or greater than the prescribed threshold value, the second slip detection section 35 determines that the slip of the second wheel 21b by the prescribed amount has occurred.

[0083] The second slip detection section 35 performs the threshold determination described above every time the second travel motor 28b rotates by a prescribed number of revolutions, for example, two revolutions. Here, the corresponding travel distance of the travel car 10 when the second travel motor 28b rotates by two revolutions is set to L2 (mm). For example, if the difference between the travel distance L2 (mm) of the travel car 10 and the change amount of the position of the travel car 10 in the travel direction detected by the travel sensor 29 is equal to or greater than 0.4 x LI (mm), the second slip detection section 35 determines that the slip of the second wheel 21b by the prescribed amount has occurred.

[0084] Thus, it is possible to detect whether the slip of the second wheel 21b by the prescribed amount has occurred at an early stage. Further, by appropriately setting the threshold value for the threshold determination, it is possible to more quickly detect the occurrence of the slip of the second wheel 21b by the prescribed amount.

[0085] If the second slip detection section 35 does not detect the slip of the second wheel 21b by the prescribed amount (NO in S2), the process returns to step S1. On the other hand, if the slip of the second wheel 21b by the prescribed amount is detected (YES in S2), the travel control section 31 controls the first servo amplifier 37 to stop the rotation of the first travel motor 28a (S3).

[0086] After step S3, the travel control section 31 controls the second servo amplifier 38 to stop the rotation of the second travel motor 28b (S4). Thus, the travel car 10 is stopped. At this point, Figure 4 The slip detection processing performed by the travel control section 31 shown in the flowchart ends.

[0087] Here, in the above example, it is assumed that when all the slip detection units, namely the first slip detection unit 34 and the second slip detection unit 35, detect slip greater than a specified amount while the travel control unit 31 has at least accelerated the travel vehicle 10, the travel control unit 31 stops the travel vehicle 10.

[0088] [Flow of Sensor Abnormality Detection Processing by the Travel Control Unit]

[0089] Next, refer to Figure 5 The flow of the sensor abnormality detection process performed by the travel control unit 31 will be described. Figure 5 This is a flowchart of an example of sensor abnormality detection processing performed by the walking control unit 31. In this embodiment, for example, Figure 5 Sensor abnormality detection processing shown.

[0090] exist Figure 5 In the flowchart shown, the travel control unit 31 first determines whether the travel vehicle 10 is traveling (S11). In step S11, the travel control unit 31 determines whether the travel vehicle 10 is traveling based on whether the first encoder 27a and the second encoder 27b detect the rotation of the first travel motor 28a and the second travel motor 28b.

[0091] If the first encoder 27a and the second encoder 27b do not detect the rotation of the first travel motor 28a and the second travel motor 28b, the travel control unit 31 determines that the travel vehicle 10 is not traveling (No in S11) and repeats step S11.

[0092] On the other hand, if the first encoder 27a and the second encoder 27b detect the rotation of the first travel motor 28a and the second travel motor 28b, the travel control unit 31 determines that the travel trolley 10 is traveling (yes in S11) and determines whether the position of the travel trolley 10 detected by the travel sensor 29 has changed (S12).

[0093] If the position of the traveling vehicle 10 detected by the traveling sensor 29 changes (YES in S12 ), the traveling control unit 31 determines that the traveling sensor 29 is operating normally and returns to step S11 .

[0094] On the other hand, if the position of the traveling vehicle 10 detected by the traveling sensor 29 does not change (No in S12), the traveling control unit 31 determines that an abnormality has occurred in the traveling sensor 29 (S13), and stops the rotation of the first traveling motor 28a and the second traveling motor 28b to stop the traveling vehicle 10 (S14). Figure 5The illustrated sensor abnormality detection processing ends.

[0095] In the stacker crane 1 of the embodiment described above, it is assumed that the traveling control section 31 stops the traveling vehicle 10 (S4) only when both the first slip detection section 34 and the second slip detection section 35 detect a slip of a prescribed amount or more (YES in S2).

[0096] Here, the stacker crane 1 has the following effect in its configuration: since the main column 11 is erected on the traveling vehicle 10, the traveling vehicle 10 tilts in the traveling direction when accelerating, and thus the front-side wheels viewed in the traveling direction are likely to slip, but on the other hand, the rear-side wheels viewed in the traveling direction are relatively unlikely to slip because the gravitational load on them can become large.

[0097] The stacker crane 1 having such a configuration is able to avoid unnecessary stopping of the traveling vehicle 10 and suppress reduction in the efficiency of the stacker crane 1 in transporting the load M even when a slip occurs in one of the first and second wheels 21a and 21b, by traveling with the other wheel.

[0098] In addition, the wheel of the first drive unit 41, i.e., the first wheel 21a, is disposed on the front side of the traveling vehicle 10, and the wheel of the second drive unit 42, i.e., the second wheel 21b, is disposed on the rear side of the traveling vehicle 10. By thus disposing the first and second wheels 21a and 21b at different positions in the traveling direction of the traveling vehicle 10, it is possible to suppress tilting of the stacker crane 1 having the main column 11 erected on the traveling vehicle 10 in the traveling direction when accelerating.

[0099] In addition, the traveling control section 31 stops the traveling vehicle 10 (S4) when the traveling sensor 29 has detected a slip of a prescribed amount or more (YES in S2). Figure 5 In the illustrated sensor abnormality detection processing, if it is determined that the traveling sensor 29 has failed or the like (S13), the traveling vehicle 10 is stopped (S14).

[0100] Here, if the traveling sensor 29 has failed, the traveling speed calculated from the amount of change in the traveling position per unit time detected by the traveling sensor 29 no longer changes. In this case, the first servo amplifier 37 supplies excessive current to the first traveling motor 28a in order to make the above-described traveling speed close to the target traveling speed, and thus the number of revolutions of the first traveling motor 28a becomes excessively large, and the traveling vehicle 10 is excessively accelerated.

[0101] In this embodiment, the traveling control section 31 stops the traveling vehicle 10 only when it is determined that the traveling sensor 29 has failed, and thus it is possible to prevent the traveling vehicle 10 from being excessively accelerated. Thus, the safety performance of the stacker crane 1 in transporting the load M is ensured.

[0102] (Other Embodiments)

[0103] Although in the foregoing embodiment, the traveling carriage 10 has two drive units, the first drive unit 41 and the second drive unit 42, it is not limited thereto. The traveling carriage 10 may, for example, have four drive units. In this case, the traveling carriage 10 can be stopped when the slip detection section of each of the four drive units detects slip of a prescribed amount or more for each corresponding wheel. Alternatively, the traveling carriage 10 can be stopped when the slip detection section of two or more of the four drive units detects slip of a prescribed amount or more for each corresponding wheel.

[0104] Further, although in the foregoing embodiment, the position detection section that detects the position of the traveling carriage 10 on the track is the traveling sensor 29 that is a laser-type distance sensor, it is not limited thereto. For example, a bar code-type distance sensor system that has a bar code provided along the track and a reading section that reads the bar code provided on the traveling carriage 10 can be used as the position detection section.

[0105] Further, a magnetic force detection-type distance sensor system that has a magnet section in which N poles and S poles are alternately arranged at prescribed intervals along the track and detects the position of the traveling carriage 10 on the track by detecting the change in magnetic force of the magnet section can be used as the position detection section. Furthermore, a scale-type distance sensor system that has a scale provided on the traveling track Rl and an encoder that measures the scale provided on the traveling carriage 10 can be used as the position detection section.

[0106] Further, although in the foregoing embodiment, the traveling control section 31 stops the traveling carriage 10 when all of the slip detection sections detect slip of a prescribed amount or more in a state in which the traveling carriage 10 is accelerated by the traveling control section 31, it is not limited thereto. For example, a scheme in which the traveling control section 31 stops the traveling carriage 10 when all of the slip detection sections detect slip of a prescribed amount or more in a state in which the traveling carriage 10 is traveling at a constant speed or in a state in which the traveling carriage 10 is decelerating can be adopted.

[0107] Further, although in the foregoing embodiment, the first slip detection section 34 detects the slip of the first wheel 21a based on the number of rotations of the first traveling motor 28a detected by the first encoder 27a and the amount of change in the position of the traveling car 10 in the traveling direction detected by the traveling sensor 29, the present application is not limited thereto. For example, the following scheme can be employed: the first slip detection section 34 determines whether the difference between the amount of change in the position of the traveling car 10 in the traveling direction detected by the traveling sensor 29 and the traveling distance of the traveling car 10 calculated from the torque command value from the first servo amplifier 37 is equal to or greater than a prescribed value, thereby detecting whether the first wheel 21a slips.

[0108] Further, although in the embodiment, the traveling car 10 is stopped if the position of the traveling car 10 in the traveling direction detected by the traveling sensor 29 does not change during the traveling of the traveling car 10, the present application is not limited thereto. For example, a torque sensor that detects the torque received by the second wheel 21b can be provided, and the traveling car 10 can be stopped when the torque detected by the torque sensor is equal to or greater than a prescribed threshold value. Thus, the second traveling motor 28b can be prevented from excessively rotating and generating heat.

[0109] Further, although in the foregoing embodiment, the first servo amplifier 37 performs torque control to obtain a torque command value that makes the difference between the traveling speed and the target traveling speed zero, the present application is not limited thereto. The first servo amplifier 37 can perform proportional control and integral control, i.e., proportional-integral control, based on the difference between the traveling speed and the target traveling speed.

[0110] [SUMMARY]

[0111] The carrying device of Mode 1 of the present disclosure includes a traveling car that travels along a track, a main column that is erected on the traveling car, a lifting section that holds a carried object and is lifted along the main column, and a control section. The traveling car has a plurality of drive units that have wheels that roll on the track, motors that drive the wheels, and slip detection sections that detect the slip of the wheels. In a state in which the traveling car is accelerated by the control section, when two or more of the slip detection sections detect the slip of the wheels by the prescribed amount or more, the control section stops the traveling car.

[0112] According to the above-described scheme, by providing a plurality of wheels, even if one wheel slips, the traveling car can travel using the remaining wheels, and the traveling car is stopped only when two or more wheels are detected to have slipped. Thus, the frequency of stopping the traveling car can be reduced, and the reduction in the carrying efficiency of the carrying device with respect to the carried object can be suppressed.

[0113] In the conveyance device according to the above-described aspect 1, the control section can be configured to stop the traveling trolley when all of the slip detection sections detect the slip of the traveling trolley by the prescribed amount or more in a state where the control section has accelerated the traveling trolley.

[0114] According to the above-described aspect, the traveling trolley is stopped only when the slip of all of the wheels is detected, so that the frequency of stopping the traveling trolley can be reduced as much as possible, and the reduction in the conveyance efficiency of the conveyance device can be further suppressed.

[0115] The conveyance device according to the above-described aspect 1 or 2 can further include a position detection section that detects the position of the traveling trolley along the track. The slip detection section can detect the slip based on the number of revolutions of the motor and the amount of change in the position detected by the position detection section.

[0116] According to the above-described aspect, the slip detection section can detect the slip based on the number of revolutions of the motor and the amount of change in the position detected by the position detection section, so that the traveling trolley can be stopped at a desired timing.

[0117] In the conveyance device according to the above-described aspect 3, the slip detection section can be configured to perform threshold determination to determine whether the difference between the distance of travel of the traveling trolley calculated based on the number of revolutions of the motor and the amount of change in the position detected by the position detection section is the prescribed threshold value or more, and the slip detection section can determine that the slip of the traveling trolley by the prescribed amount or more has occurred when the difference is the threshold value or more.

[0118] According to the above-described aspect, the occurrence of the slip of the wheels can be detected promptly by appropriately setting the threshold value for the threshold determination.

[0119] In the conveyance device according to the above-described aspect 1 to 4, the plurality of drive units can include a first drive unit and a second drive unit. The wheels of the first drive unit and the wheels of the second drive unit can be disposed at different positions on the traveling trolley in the traveling direction of the traveling trolley.

[0120] According to the above-described aspect, by disposing the wheels of the first drive unit and the wheels of the second drive unit at different positions on the traveling trolley in the traveling direction, the inclination of the conveyance device in the traveling direction at the time of acceleration is suppressed, so that the reduction in the conveyance efficiency of the conveyance object can be effectively suppressed.

[0121] In the transporting device of aspect 6 of the present disclosure based on any one of aspects 1 to 5 above, the following scheme may also be adopted: while the traveling trolley is traveling by the rotation of the motor of the drive unit, if the position detected by the position detection unit does not change, the control unit determines that an abnormality has occurred in the position detection unit and stops the traveling trolley.

[0122] According to the above aspect, the control unit stops the traveling carriage when it is determined that an abnormality has occurred in the position detection unit. This prevents the traveling carriage from being over-accelerated, thereby improving the safety of the transport device.

[0123] In the transport device according to claim 7 of the present disclosure based on claim 3, the slippage detection unit may perform the threshold determination every time the motor rotates a predetermined number of times.

[0124] According to the above aspect, the threshold value determination is performed every time the electric motor rotates a predetermined number of times, thereby making it possible to detect the occurrence of slip of each wheel at an early stage.

[0125] In the transport device according to aspect 8 of the present disclosure based on any one of aspects 1 to 7, the drive unit may include a reporting unit that notifies the outside when the slippage detection unit detects the slippage exceeding the predetermined amount.

[0126] According to the above aspect, each of the plurality of drive units includes a notification unit, and each notification unit issues a notification corresponding to the wheel that has slipped. Thus, when, for example, only some of the wheels have slipped, the user can identify the wheel in question and take appropriate measures.

[0127] The present disclosure is not limited to the aforementioned embodiments, and various changes can be made within the scope of the technical ideas described in the specification. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

Claims

1. A carrying device provided with: a traveling trolley that travels along a track; a main column that is erected on the traveling trolley; a lifting section that holds a carried object and is lifted along the main column; and a control section, The carrying device is characterized in that the traveling trolley has a plurality of drive units that have a wheel that rolls on the track, a motor that drives the wheel, and a slip detection section that detects a slip of the wheel, in a state in which the control section at least causes the traveling trolley to accelerate, when two or more of the slip detection sections detect the slip of a prescribed amount or more, the control section stops the traveling trolley.

2. The carrying device according to claim 1, characterized in that in the state in which the control section at least causes the traveling trolley to accelerate, when all of the slip detection sections detect the slip of a prescribed amount or more, the control section stops the traveling trolley.

3. The carrying device according to claim 1 or 2, characterized in that it is further provided with a position detection section that detects a position of the traveling trolley along the track, the slip detection section detects the slip based on a number of revolutions of the motor and a change amount of the position detected by the position detection section.

4. The carrying device according to claim 3, characterized in that the slip detection section performs threshold determination to determine whether a difference between a traveling distance of the traveling trolley calculated based on the number of revolutions of the motor and the change amount of the position detected by the position detection section is a prescribed threshold value or more, and the slip detection section determines that the slip of a prescribed amount or more has occurred in a case in which the difference is the threshold value or more.

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