Article carrier

Abstract

To detect that a first guide roller of a first guide-roller pair is worn and / or that a second guide roller of a second guide-roller pair is worn.SOLUTION: A stacker crane (1A) includes first and second range sensors (80A), (80B) attached relatively to a first side frame (211). A distance (L1) between the first range sensor (80A) and the first guide-roller pair (28) is shorter than a distance (L2) between the first range sensor (80A) and the first drive wheel (22), and a distance (L3) between the second range sensor (80B) and the second guide-roller pair (29) is shorter than a distance (L4) between the second range sensor (80B) and the second drive wheel (23).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an article transport device. [Background technology]

[0002] Conventionally, there is known an article transport device that travels along a guide rail to transport articles. For example, Patent Documents 1 and 2 describe a traveling cart that an article transport device has. The traveling cart has a pair of guide rollers that sandwich a rail on which the wheels of the traveling cart roll from both sides. When the drive wheels of the traveling cart are driven, the pair of guide rollers each roll on the side of the rail. This enables the article transport device to travel along the rail. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 2572993 [Patent Document 2] Patent No. 3702738 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as a result of the traveling cart traveling, each of the pair of guide rollers wears out. When the guide rollers wear out, the inclination of the traveling cart with respect to the rail increases. Therefore, wear of the guide rollers is considered to be a cause of a decrease in the straight-line performance of the article transport device.

[0005] An aspect of the present invention aims to detect wear of a first guide roller of a first guide roller pair and / or wear of a second guide roller of a second guide roller pair. [Means for solving the problem]

[0006] In order to solve the above problems, an item transport device according to one aspect of the present invention includes a first wheel, a second wheel arranged at a distance from the first wheel in a running direction that is a direction along a guide rail, a first guide roller pair having a pair of first guide rollers that sandwich the guide rail in a direction intersecting the running direction, a second guide roller pair having a pair of second guide rollers that sandwich the guide rail in a direction intersecting the running direction and arranged at a distance from the first guide roller pair in the running direction, a frame whose longitudinal direction is the running direction, and to which the first guide roller and the second guide roller are attached, a first sensor that detects the horizontal distance between the frame and the guide rail, and a sensor arranged at a distance from the first sensor in the running direction, the frame and a front ... and a running carriage having a first sensor and a second sensor that detects the horizontal distance between the first sensor and the guide rail, wherein the first sensor and the second sensor are attached to the frame, the first guide roller pair is located closer to the first wheel than the second guide roller pair and the second sensor in the running direction, the first sensor is located closer to the first wheel than the second guide roller pair and the second sensor in the running direction, the distance between the first sensor and the first guide roller pair in the running direction is shorter than the distance between the first sensor and the first wheel in the running direction, and the distance between the second sensor and the second guide roller pair in the running direction is shorter than the distance between the second sensor and the second wheel in the running direction.

[0007] According to the above configuration, the first sensor is provided near the first guide roller pair, and the second sensor is provided near the second guide roller pair, making it possible to detect when the first guide roller of the first guide roller pair is worn and / or when the second guide roller of the second guide roller pair is worn. Effect of the Invention

[0008] According to one aspect of the present invention, it is possible to detect wear of the first guide roller of the first guide roller pair and / or wear of the second guide roller of the second guide roller pair. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an example of an article transport facility according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of the stacker crane shown in FIG. [Diagram 3] 3 is a perspective view of a traveling carriage provided on the stacker crane shown in FIG. 2. [Figure 4] 3 is a plan view of a traveling carriage provided on the stacker crane shown in FIG. 2, seen from above. [Diagram 5] 3 is a plan view of a lifting platform provided in the stacker crane shown in FIG. 2, seen from above. [Figure 6] 3 is a cross-sectional view of a lifting platform provided on the stacker crane shown in FIG. 2, viewed from the right side. [Figure 7] 4 is a schematic diagram illustrating a barcode reader and a barcode attached to a side surface of a traveling rail. FIG. [Figure 8] FIG. 3 is a block diagram showing an electrical configuration of the stacker crane shown in FIG. 2. [Figure 9] 10 is a schematic diagram illustrating the inclination of the traveling carriage, the lifting platform, and the fork section relative to the traveling guide rail when the stacker crane is stopped. FIG. [Figure 10] FIG. 11 is a plan view, seen from above, of a stacker crane provided in an article transport facility according to a second embodiment of the present invention. [Figure 11] 11 is a cross-sectional view taken at the center position and line A-A shown in FIG. 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS.

[0011] [Goods transport equipment] An overview of the article conveying facility 100 will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing an example of the article conveying facility 100. For ease of explanation, the up-down direction, the front-rear direction, and the left-right direction are defined as shown by the arrows in Fig. 1 etc. In this embodiment, the up-down direction is a direction perpendicular to the front-rear direction and the left-right direction, and the front-rear direction is a direction perpendicular to the left-right direction.

[0012] The article transport facility 100 shown in FIG. 1 includes a stacker crane 1, a load shelf 2, a travel guide rail 3, and a travel rail 4. The load shelf 2 is a shelf on which articles can be placed. The load shelf 2 is provided with a plurality of tiers in the vertical direction, and the space for placing articles is partitioned in the left-right direction of each tier. Between the front load shelf 2 and the rear load shelf 2, the travel guide rail 3 and the travel rail 4 constituting the travel path of the stacker crane 1 are installed on the floor, and the stacker crane 1 can travel between the front load shelf 2 and the rear load shelf 2. The travel guide rail 3 is an example of a guide rail. The travel rail 4 is installed in parallel with the travel guide rail 3. The longitudinal direction of the travel guide rail 3 and the travel rail 4 is the left-right direction.

[0013] The stacker crane 1 is a device that transports articles. The stacker crane 1 is an example of an article transport device. The vertical height of the stacker crane 1 is about 2m to 18m. The stacker crane 1 travels along a traveling guide rail 3. In this embodiment, the traveling direction D1 of the stacker crane 1 is the left-right direction. In the article transport equipment 100, a plurality of stacker cranes 1 travel on the same traveling guide rail 3 and traveling rail 4. Note that the article transport equipment 100 may be configured such that one stacker crane 1 travels on the traveling guide rail 3 and traveling rail 4.

[0014] In the following description, the stacker crane 1 shown on the left side of FIG. 1 will be referred to as stacker crane 1A, and the stacker crane 1 shown on the right side of FIG. 1 will be referred to as stacker crane 1B.

[0015] When the stacker cranes 1A and 1B are in a standby state and not transporting any goods, they wait at their respective home positions HP1 and HP2. The home position HP1 of the stacker crane 1A is provided on the left side of the travel guide rail 3, and the home position HP2 of the stacker crane 1B is provided on the right side of the travel guide rail 3. An inlet / outlet EP1 for transferring goods to the stacker crane 1A is provided on the right side of the home position HP1, and an inlet / outlet EP2 for transferring goods to the stacker crane 1B is provided on the left side of the home position HP2. The home position HP1 and the inlet / outlet EP1 may be the same position, or the home position HP2 and the inlet / outlet EP2 may be the same position. The transport position CP1 is a position where the stacker crane 1A can take in and take out goods from the front shelf 2 or the rear shelf 2, and the transport position CP2 is a position where the stacker crane 1B can take in and take out goods from the front shelf 2 or the rear shelf 2. The transport positions CP1 and CP2 differ depending on the position of the front or rear shelf 2 on which the goods to be put in or taken out are placed. The transport position CP1 of the stacker crane 1A is a position on the right side of the traveling guide rail 3 from the loading / unloading entrance EP1, and the transport position CP2 of the stacker crane 1B is a position on the left side of the traveling guide rail 3 from the loading / unloading entrance EP2.

[0016] The stacker crane 1A moves to the home position HP1, the loading / unloading entrance EP1, or the transport position CP1 in accordance with the transport command signal. The stacker crane 1B moves to the home position HP2, the loading / unloading entrance EP2, or the transport position CP2 in accordance with the transport command signal. For example, when the stacker crane 1A receives a transport command signal to put an article in the fourth row from the left of the front shelf 2, the stacker crane 1A receives the article from the storage conveyor at the loading / unloading entrance EP2, and then moves to the transport position CP1 shown in FIG. 1. When the stacker crane 1A completes putting the article in the front shelf 2 at the transport position CP1 shown in FIG. 1, it moves to the home position HP1, the loading / unloading entrance EP1, or the transport position CP1 in accordance with the next transport command signal. On the other hand, when the stacker crane 1A receives a transport command signal to take out the article placed in the fourth row from the left of the front shelf 2, the stacker crane 1A moves to the transport position CP1 shown in FIG. 1. When the removal of the article from the shelf 2 at the transfer position CP1 shown in Fig. 1 is completed, the stacker crane 1A moves to the loading / unloading entrance EP1 and delivers the article to the unloading conveyor at the loading / unloading entrance EP1. The stacker crane 1A moves to the home position HP1, the loading / unloading entrance EP1, or the transfer position CP1 according to the next transfer command signal.

[0017] In addition, the loading / unloading entrances EP1 and EP2 are located on the outside of the luggage rack 2 in the traveling direction, but the present invention is not limited to this configuration. The loading / unloading entrances EP1 and EP2 may be located at positions overlapping with the luggage rack 2 in the traveling direction. That is, the loading / unloading entrances EP1 and EP2 may be provided on either the front or rear luggage rack 2. In this case, the luggage rack 2 on which the loading / unloading entrances EP1 and EP2 are provided has an opening through which goods can be handed over. For example, the stacker crane 1A stops in front of the row of luggage racks 2 on which the loading / unloading entrance EP1 is provided. In addition, the loading / unloading entrances EP1 and EP2 are different loading / unloading entrances, but the present invention is not limited to this configuration. The loading / unloading entrance EP2 may be the same loading / unloading entrance as the loading / unloading entrance EP1.

[0018] [Stacker crane] Next, a detailed configuration of the stacker crane 1A will be described with reference to Figures 2 to 7. Figure 2 is a perspective view showing the stacker crane 1A shown in Figure 1. As shown in Figure 2, the stacker crane 1A includes a mast 10, a traveling cart 20, a lifting platform 30, a control box 40, and a driver box 45.

[0019] 〔mast〕 The masts 10 are columnar members extending in the vertical direction. The stacker crane 1A is provided with a pair of masts 10. In the following description, the mast 10 on the left side of the drawing (the home position HP1 side) is referred to as the first mast 10A, and the mast 10 on the right side of the drawing (the transport position CP1 side) is referred to as the second mast 10B.

[0020] The first mast 10A and the second mast 10B are spaced apart in the left-right direction. A lift platform 30, which will be described later, is provided between the first mast 10A and the second mast 10B. Each of the first mast 10A and the second mast 10B is provided with a lift guide rail 11. The lift guide rail 11 guides the lift platform 30 in the up-down direction.

[0021] An upper frame 12 is provided above the masts 10. The upper frame 12 is provided so as to connect the upper end of the first mast 10A and the upper end of the second mast 10B. The upper frame 12 engages with an upper rail (not shown) provided along the traveling guide rail 3. In addition, the upper frame 12 is provided with guide rollers, and the upper part of the mast 10 is guided along the upper rail by the guide rollers of the upper frame 12. In other words, the upper end of the mast 10 is guided in the traveling direction D1 by the upper rail. Note that the stacker crane 1A may be configured without the upper frame 12.

[0022] A lift motor 13, which is a drive unit for raising and lowering the lift platform 30 relative to the mast 10, is provided below each of the pair of masts 10. The lift motor 13 is provided on the rear side of the mast 10, i.e., on the traveling rail 4 side of the mast 10.

[0023] The lifting motor 13 drives a drive drum (not shown) provided below the mast 10. When the lifting motor 13 rotates forward or backward, a lifting belt (not shown) wound around the drive drum advances and retreats from the drive drum. A pulley for engaging the lifting belt is provided above the pair of masts 10. A lifting platform 30 is fixed to one end of the lifting belt, and a counterweight is fixed to the other end of the lifting belt. The lifting platform 30 moves up and down along the lifting guide rail 11 as the lifting belt advances and retreats. That is, the lifting platform 30 ascends and descends in a lifting direction D2 relative to the mast 10 as driven by the lifting motor 13. The lifting platform 30 may ascend and descend relative to the mast 10 by a lifting wire or a lifting chain instead of a lifting belt.

[0024] [Traveling cart] Next, a detailed configuration of the traveling cart 20 will be described with reference to Fig. 3 and Fig. 4. Fig. 3 is a perspective view of the traveling cart 20 provided in the stacker crane 1A shown in Fig. 2. Fig. 4 is a plan view of the traveling cart 20 provided in the stacker crane 1A shown in Fig. 2, seen from above. As shown in Figs. 3 and 4, the traveling cart 20 has a cart frame 21. The cart frame 21 is composed of a first side frame 211, a second side frame 212, a first connection frame 213, and a second connection frame 214. In this embodiment, the first side frame 211, the second side frame 212, the first connection frame 213, and the second connection frame 214 are integrally formed.

[0025] In addition, each of the frames 211-214 constituting the carriage frame 21 is not limited to being integrally formed, and may be separate members. In this case, the left end of the first connection frame 213 and the left end of the second connection frame 214 are fixed to the first connection frame 213 with bolts or the like. In addition, the right end of the first connection frame 213 and the right end of the second connection frame 214 are fixed to the second connection frame 214 with bolts or the like. By making each of the frames 211-214 separate members, the large-sized stacker crane 1 can be delivered in a disassembled state. Therefore, the stacker crane 1 can be transported compactly at the time of delivery.

[0026] As shown in FIG. 3, the first side frame 211 is a frame located in front of the traveling carriage 20, and extends in a direction along the traveling guide rail 3 and the traveling rail 4. That is, the first side frame 211 is a frame whose longitudinal direction is the left-right direction, which is the traveling direction D1. The second side frame 212 is a frame located in the rear of the traveling carriage 20, and extends in a direction along the traveling guide rail 3 and the traveling rail 4. That is, the second side frame 212 is a frame whose longitudinal direction is the left-right direction. As shown in FIG. 4, the second side frame 212 faces the first side frame 211 in the front-rear direction. The length of the second side frame 212 in the left-right direction is shorter than the length of the first side frame 211 in the left-right direction.

[0027] As shown in Fig. 3, the first connection frame 213 is a frame that connects the first side frame 211 and the second side frame 212, and is located on the left side of the traveling carriage 20. More specifically, the first connection frame 213 connects the left end side of the first side frame 211 and the left end side of the second side frame 212. The first connection frame 213 is a frame whose longitudinal direction is the front-rear direction. As shown in Fig. 4, the first mast 10A is erected on the first connection frame 213.

[0028] As shown in FIG. 3, the second connection frame 214 is a frame that connects the first side frame 211 and the second side frame 212, and is located on the right side of the traveling carriage 20. More specifically, the second connection frame 214 connects the right end side of the first side frame 211 and the right end of the second side frame 212. The second connection frame 214 is a frame whose longitudinal direction is the front-rear direction. The second connection frame 214 faces the first connection frame 213 in the left-right direction. As shown in FIG. 4, the second mast 10B is erected on the second connection frame 214.

[0029] 3, the traveling carriage 20 has a plurality of wheels that travel on the traveling guide rail 3 and the traveling rail 4. More specifically, the traveling carriage 20 has a first driving wheel 22, a second driving wheel 23, a first driven wheel 24, and a second driven wheel 25. The first driving wheel 22 is an example of a first wheel, and the second driving wheel 23 is an example of a second wheel.

[0030] The first drive wheel 22 and the second drive wheel 23 are attached to the first side frame 211 and roll on the upper surface of the travel guide rail 3. The first drive wheel 22 is arranged spaced apart from the second drive wheel 23 in the left-right direction. More specifically, the first drive wheel 22 is located at the left end side of the first side frame 211 as viewed from the center position CL in the left-right direction of the bogie frame 21, and the second drive wheel 23 is located at the right end side of the first side frame 211 as viewed from the center position CL. The first drive wheel 22 is located to the left of the first connection frame 213 in the left-right direction. The second drive wheel 23 is located to the right of the second connection frame 214 in the left-right direction.

[0031] The first driven wheel 24 and the second driven wheel 25 are attached to the second side frame 212 and roll on the upper surface of the traveling rail 4. The first driven wheel 24 is arranged spaced apart from the second driven wheel 25 in the left-right direction. More specifically, the first driven wheel 24 is located on the left end side of the second side frame 212 as viewed from the center position CL in the left-right direction of the carriage frame 21, and the second driven wheel 25 is located on the right end side of the second side frame 212 as viewed from the center position CL. The first driven wheel 24 is located to the right of the first driving wheel 22 in the left-right direction. The second driven wheel 25 is located to the left of the second driving wheel 23 in the left-right direction.

[0032] The carriage frame 21 is provided with a travel motor 26 which is a drive unit for driving the stacker crane 1A. In the following description, the travel motor 26 on the left side (home position HP1 side) is referred to as the first travel motor 26A, and the travel motor 26 on the right side (transport position CP1 side) is referred to as the second travel motor 26B. The first travel motor 26A is located at the left end of the first side frame 211, and drives the first drive wheel 22. The second travel motor 26B is located at the right end of the first side frame 211, and drives the second drive wheel 23.

[0033] The traveling carriage 20 has a first guide roller pair 28 and a second guide roller pair 29. The first guide roller pair 28 and the second guide roller pair 29 are attached to the first side frame 211. The second guide roller pair 29 is disposed apart from the first guide roller pair 28 in the left-right direction. The first guide roller pair 28 is located on the left side in the left-right direction, and the second guide roller pair 29 is located on the right side in the left-right direction. That is, the first guide roller pair 28 is located closer to the first driving wheel 22 than the second guide roller pair 29 in the left-right direction. Also, the first guide roller pair 28 is located closer to the first driving wheel 22 than a second distance sensor 80B described later in the left-right direction. The first guide roller pair 28 and the second guide roller pair 29 are located between the first driving wheel 22 and the second driving wheel 23 in the left-right direction.

[0034] By positioning the first guide roller pair 28 and the second guide roller pair 29 between the first drive wheel 22 and the second drive wheel 23, the first guide roller pair 28 and the second guide roller pair 29 are provided in the space between the first drive wheel 22 and the second drive wheel 23. This allows the first guide roller pair 28 and the second guide roller pair 29 to be provided on the frame of the traveling carriage 20 without being restricted by other members.

[0035] As shown in FIG. 4, the first guide roller pair 28 is located on the left side of the first side frame 211 and on the right side of the first connection frame 213 when viewed from the center position CL in the left-right direction of the carriage frame 21. The first guide roller pair 28 is composed of a pair of first guide rollers 281. The pair of first guide rollers 281 sandwich the traveling guide rail 3 in the front-rear direction. More specifically, the front first guide roller 281 abuts against the front side surface of the traveling guide rail 3 and rolls on the front side surface of the traveling guide rail 3. The rear first guide roller 281 abuts against the rear side surface of the traveling guide rail 3 and rolls on the rear side surface of the traveling guide rail 3.

[0036] The second guide roller pair 29 is located on the right side of the first side frame 211 and on the left side of the second connection frame 214 when viewed from the center position CL in the left-right direction of the carriage frame 21. The second guide roller pair 29 is composed of a pair of second guide rollers 291. The pair of second guide rollers 291 sandwich the traveling guide rail 3 in the front-rear direction. More specifically, the front second guide roller 291 abuts against the front side surface of the traveling guide rail 3 and rolls on the front side surface of the traveling guide rail 3. The rear second guide roller 291 abuts against the rear side surface of the traveling guide rail 3 and rolls on the rear side surface of the traveling guide rail 3.

[0037] The first guide roller 281 of the first guide roller pair 28 and the second guide roller 291 of the second guide roller pair 29 are elastic rollers. As an example, the first guide roller 281 and the second guide roller 291 are made of urethane. When the first drive wheel 22 and the second drive wheel 23 are driven, the traveling cart 20 is guided in a direction along the traveling guide rail 3 by the first guide roller pair 28 and the second guide roller pair 29. As a result, the stacker crane 1A travels along the traveling direction D1.

[0038] According to the above configuration, the traveling guide rail 3 on which the first driving wheel 22 and the second driving wheel 23 travel is sandwiched between the first guide roller pair 28 and the second guide roller pair 29. Therefore, the first guide roller pair 28 and the second guide roller pair 29 can make it easier for the traveling cart to travel straight in the traveling direction D1. This can improve the straight-line traveling performance of the traveling cart.

[0039] As shown in Fig. 3, a plurality of distance sensors 80 are attached to the first side frame 211 of the traveling cart 20. The distance sensors 80 are sensors that detect the horizontal distance between the first side frame 211 and the traveling guide rail 3. More specifically, the distance sensors 80 detect the horizontal distance between the front surface of the first side frame 211 and the rear side surface of the traveling guide rail 3. In this embodiment, the distance sensors 80 detect the distance in the front-rear direction between the first side frame 211 and the traveling guide rail 3. An example of the distance sensor 80 is an infrared sensor.

[0040] In the following description, the distance sensor 80 on the left side of the drawing (home position HP1 side) is referred to as the first distance sensor 80A, and the distance sensor 80 on the right side of the drawing (transport position CP1 side) is referred to as the second distance sensor 80B. The first distance sensor 80A is an example of the first sensor, and the second distance sensor 80B is an example of the second sensor.

[0041] As shown in Fig. 4, the first distance sensor 80A and the second distance sensor 80B are positioned between the first driving wheel 22 and the second driving wheel 23 in the left-right direction. More specifically, the first distance sensor 80A and the second distance sensor 80B are positioned between the first guide roller pair 28 and the second guide roller pair 29 in the left-right direction. By positioning the first distance sensor 80A and the second distance sensor 80B between the first driving wheel 22 and the second driving wheel 23, the first distance sensor 80A and the second distance sensor 80B are attached to the space between the first driving wheel 22 and the second driving wheel 23. This allows the first distance sensor 80A and the second distance sensor 80B to be attached to the frame of the traveling cart 20 without being restricted by other members.

[0042] The first distance sensor 80A may be located between the first driving wheel 22 and the first guide roller pair 28 in the left-right direction. The second distance sensor 80B may be located between the second driving wheel 23 and the second guide roller pair 29 in the left-right direction.

[0043] The first distance sensor 80A is disposed apart from the second distance sensor 80B in the left-right direction. The first distance sensor 80A is located on the left side in the left-right direction, and the second distance sensor 80B is located on the right side in the left-right direction. That is, the first distance sensor 80A is located closer to the first driving wheel 22 than the second distance sensor 80B in the left-right direction. Also, the first distance sensor 80A is located closer to the first driving wheel 22 than the second guide roller pair 29 in the left-right direction. The first distance sensor 80A and the second distance sensor 80B are attached on opposite sides in the left-right direction as viewed from the center position CL in the left-right direction of the carriage frame 21. The first distance sensor 80A is on the left side as viewed from the center position CL in the left-right direction of the first side frame 211, and the second distance sensor 80B is on the right side as viewed from the center position CL in the left-right direction of the first side frame 211.

[0044] According to the above configuration, the interval between the first distance sensor 80A located on one side of the center position CL in the left-right direction and the second distance sensor 80B located on the other side of the center position CL in the left-right direction can be increased, so that the inclination of the traveling carriage with respect to the guide rail can be detected more accurately.

[0045] The first distance sensor 80A is attached at a position closer to the first driving wheel 22 than the second distance sensor 80B. The first distance sensor 80A is disposed near the first guide roller pair 28. Specifically, a distance L1 between the first distance sensor 80A and the first guide roller pair 28 in the left-right direction is shorter than a distance L2 between the first distance sensor 80A and the first driving wheel 22 in the left-right direction. More specifically, the distance L1 is the distance between the first distance sensor 80A and the center of the rotation shaft of the first guide roller 281 of the first guide roller pair 28 in the left-right direction. In addition, the distance L2 is the distance between the first distance sensor 80A and the center of the rotation shaft of the first driving wheel 22 in the left-right direction.

[0046] Further, the second distance sensor 80B is disposed near the second guide roller pair 29. Specifically, a distance L3 between the second distance sensor 80B and the second guide roller pair 29 in the left-right direction is shorter than a distance L4 between the second distance sensor 80B and the second driving wheel 23 in the left-right direction. More specifically, the distance L3 is the distance between the second distance sensor 80B and the center of the rotation shaft of the second guide roller 291 of the second guide roller pair 29 in the left-right direction. The distance L4 is the distance between the second distance sensor 80B and the center of the rotation shaft of the second driving wheel 23 in the left-right direction.

[0047] As shown in Figs. 3 and 4, a barcode reader 81 is attached to the second side frame 212 of the traveling cart 20. The barcode reader 81 is a device that reads a barcode 83 attached to the front side surface of the traveling rail 4. The barcode reader 81 is disposed between the traveling guide rail 3 and the traveling rail 4 in a top view. That is, the barcode reader 81 is attached to the traveling cart 20 so as to be located between the traveling guide rail 3 and the traveling rail 4 in the front-rear direction. The barcode reader 81 faces the front side surface of the traveling rail 4.

[0048] Here, the barcode reader 81 and the barcode 83 will be described with reference to FIG. 7. FIG. 7 is a schematic diagram for describing the barcode reader 81 and the barcode 83 attached to the side surface of the traveling rail 4. As shown in FIG. 7, the barcode 83 is attached to the side surface of the traveling rail 4. More specifically, the barcode 83 is attached to the front side surface of the traveling rail 4. The barcode 83 contains position information which is information about the position in the longitudinal direction of the traveling rail 4. The position information contained in the barcode 83 is information corresponding to the position of the stacker crane 1A in the traveling direction. The stacker crane 1A moves to the home position HP1 or the transfer position CP1 based on the position information read from the barcode 83 of the traveling rail 4.

[0049] 4, an emergency stop sensor 82 is attached to the first side frame 211. The emergency stop sensor 82 is a sensor for stopping the travel of the stacker crane 1A when the stacker crane 1A travels beyond the home position HP1 or the transfer position CP1 where the stacker crane 1A is scheduled to stop.

[0050] The cable 90 is a cable that supplies power to the stacker crane 1A. The cable 90 enables the supply of power to each drive unit equipped in the stacker crane 1A. The cable 90 is held by a cable bear (registered trademark) and follows the travel of the stacker crane 1A. The cable 90 is connected to the traveling carriage 20 from an area opposite to the area where the traveling guide rail 3 is located, of two areas defined around the traveling rail 4 in a direction perpendicular to the traveling direction D1 in a top view. That is, the cable 90 is connected to the traveling carriage 20 from the rear of the traveling rail 4 in the front-rear direction, with the traveling rail 4 as the center.

[0051] [Lifting platform] The detailed configuration of the lifting platform 30 will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a plan view of the lifting platform 30 provided in the stacker crane 1A shown in Fig. 2, seen from above. Fig. 6 is a cross-sectional view of the lifting platform 30 provided in the stacker crane 1A shown in Fig. 2, seen from the right side.

[0052] The lifting platform 30 is capable of placing an article M thereon (see FIG. 6) and is provided so as to be movable up and down relative to the mast 10. As shown in FIG. 5, the lifting platform 30 has a lifting platform frame 31, a fork unit 60, a swivel unit 70, and a cable box 37. The fork unit 60 and the swivel unit 70 are mounted on the lifting platform frame 31.

[0053] The lift platform frame 31 is provided with a guide portion 32 that guides the lift platform 30 in the lifting direction D2 as the lift belt advances and retreats. The guide portion 32 has a fixed portion 33 and a guide shoe 35. One end of the lift belt inserted from an opening 34 formed in the fixed portion 33 is fixed to the fixed portion 33. As the lift belt advances and retreats, the fixed portion 33 is pulled upward or the fixed portion 33 descends downward. The guide shoe 35 engages with the lift guide rail 11 of the mast 10 and slides relative to the lift guide rail 11.

[0054] The fork section 60 places an article M in and out between the shelf 2 and the lifting platform 30. The fork section 60 is provided on a rotating frame 71 of the rotating section 70, which will be described later. The fork section 60 has a fork 61, an arm section 62, a gear box 65, and a fork motor unit 66. The fork 61 has a placement surface 611 (see FIG. 6) on which the article M can be placed. The upper surface of the fork 61 is the placement surface 611. The fork 61 is attached to the gear box 65.

[0055] A pair of arm portions 62 are provided on the left and right. As the arm portions 62 move forward and backward, the fork 61 moves in the forward and backward direction D4 (see FIG. 6) relative to the lifting platform 30. The arm portion 62 has a first arm 63 and a second arm 64. One end 631 of the first arm 63 in the longitudinal direction is connected to the fork 61 via a gear box 65. The first arm 63 rotates relative to the gear box 65 around a rotation axis A1.

[0056] The second arm 64 is connected to the other end 632 of the first arm 63 in the longitudinal direction. In other words, the first arm 63 is provided on one end 641 of the second arm 64 in the longitudinal direction. The first arm 63 rotates relative to the second arm 64 about the rotation axis A2.

[0057] A fork motor 67 (see FIG. 6) of a fork motor unit 66 is connected to the other end 642 in the longitudinal direction of the second arm 64. The fork motor unit 66 is a drive unit for moving the fork 61 in the forward and backward direction D4. The second arm 64 rotates about the rotation axis A3 relative to the lifting platform 30 as the driving force of the fork motor 67 is transmitted to the second arm 64.

[0058] A plurality of fork motor units 66 are provided. The fork motor unit 66 includes a fork motor 67 and an encoder (not shown). The fork motor 67 rotates forward or backward, causing the pair of second arms 64 to rotate about the rotation axis A3. When each second arm 64 rotates about the rotation axis A3, one end 641 of each second arm 64 moves forward or backward. As the one end 641 of each second arm 64 moves in the front-rear direction, the pair of first arms 63 move in the front-rear direction. At this time, the other end 632 of each first arm 63 rotates relative to the second arm 64, and the one end 631 of each first arm 63 rotates relative to the gear box 65. As the one end 631 of each first arm 63 moves in the front-rear direction, the fork 61 moves in the front-rear direction together with the gear box 65. In this embodiment, the forward / rearward direction D4 of the fork 61 of the fork section 60 is the front-rear direction.

[0059] The swivel unit 70 rotates relative to the lift platform 30 to swivel the fork unit 60. The swivel unit 70 includes a swivel frame 71 and a swivel motor unit 75.

[0060] The swivel frame 71 is a disk-shaped member and is provided with the fork portion 60. As shown in FIG. 6, the swivel frame 71 is connected to a rotation axis A4 of a swivel motor 76 of the swivel motor unit 75. The swivel motor unit 75 is a drive unit that rotates the swivel frame 71. The swivel motor unit 75 has a swivel motor 76 and an encoder (not shown). When a driving force is applied from the swivel motor 76 to the swivel frame 71, the swivel frame 71 rotates around the rotation axis A4. When the swivel frame 71 rotates relative to the lift platform 30, the fork portion 60 rotates in a rotation direction D3 relative to the lift platform 30.

[0061] The position of the fork unit 60 shown in Fig. 5 is a position that allows an article M to be placed on or removed from the load shelf 2 in front of the stacker crane 1A. When the swivel frame 71 of the swivel unit 70 rotates 180° from the position shown in Fig. 5, the fork unit 60 also rotates together with the rotation of the swivel frame 71. When the fork unit 60 rotates 180° from the position shown in Fig. 5, the fork unit 60 becomes able to place an article M on or remove from the load shelf 2 in the rear of the stacker crane 1A.

[0062] The cable box 37 is a box in which cables for connecting various devices such as sensors mounted on the lift platform 30 to devices disposed outside the lift platform 30 are collected. The cable box 37 is disposed on the left side (home position HP1 side) of the lift platform 30. The cable box 37 collects cables for communicating signals with the fork motor unit 66 and the swivel motor unit 75 mounted on the lift platform 30. A connector plate is disposed in the cable box 37 on which a connector to which a lift cable is connected is disposed. The connector of the cable box 37 is connected to a connector disposed on the connector plate of the driver box 45 by a lift cable.

[0063] [Control box] A control box 40 is attached to the first mast 10A. The control box 40 is attached to the rear side of the first mast 10A in the front-to-rear direction. The control box 40 is a housing that houses a control device 41 that performs electronic control of the entire stacker crane 1A. The control device 41 is an example of a control unit.

[0064] The electrical configuration of the stacker crane 1A will be described with reference to Fig. 8. Fig. 8 is a block diagram showing the electrical configuration of the stacker crane 1A shown in Fig. 2. As shown in Fig. 8, the control device 41 is composed of a computer equipped with a processor such as a CPU (Central Processing Unit), a memory such as a RAM or a ROM, and a communication interface. The processor of the control device 41 executes various programs stored in the memory to perform various controls and various calculations. The processor of the control device 41 mainly executes travel control of the stacker crane 1A, lifting and lowering control of the lifting platform 30, advancement and retreat control of the fork section 60, and rotation control of the rotating section 70.

[0065] The control device 41 is connected to a lift driver 46 that controls the power supplied to the lift motor 13, a travel driver 47 that controls the power supplied to the travel motor 26, a fork driver 48 that controls the power supplied to the fork motor 67, and a slewing driver 49 that controls the power supplied to the slewing motor 76 so that information can be communicated therewith.

[0066] The control device 41 controls each of the drivers 46-49. Specifically, the control device 41 transmits a command signal to each of the drivers 46-49 to control the operation of each of the drivers 46-49. More specifically, the control device 41 transmits a position command to each of the drivers 46-49. Each of the drivers 46-49 outputs electric power to be supplied to each of the motors 13, 26, 67, 76 based on the command signal from the control device 41.

[0067] The control device 41 is also electrically connected to the distance sensor 80, the barcode reader 81, and the emergency stop sensor 82. The control device 41 calculates the distance between the traveling guide rail 3 and the traveling cart 20 based on a signal obtained from the distance sensor 80. The control device 41 obtains position information read by the barcode reader 81, and controls the traveling driver 47 based on the obtained position information. The control device 41 controls the traveling driver 47 based on a signal obtained from the emergency stop sensor 82.

[0068] [Driver box] As shown in FIG. 2, a driver box 45 is attached to the first mast 10A. The driver box 45 is attached to the front side of the first mast 10A in the front-rear direction. The driver box 45 stores a lift driver 46, a travel driver 47, a fork driver 48, and a swivel driver 49. The drivers 46 to 49 are all collected together in one driver box 45. The fork driver 48 and the swivel driver 49 are disposed outside the lift platform 30. The fork driver 48 and the swivel driver 49 are connected to the cable box 37 of the lift platform 30 by a lift cable (not shown).

[0069] 8, the lift driver 46 is electrically connected to the lift motor 13. The lift driver 46 controls the amount of current supplied to the lift motor 13 based on a command signal from the control device 41. The lift driver 46 controls the amount of current supplied to the lift motor 13 based on information fed back from an encoder (external encoder or lift motor encoder) not shown. The lift driver 46 includes a drive circuit that supplies current to the lift motor 13.

[0070] The travel driver 47 is electrically connected to the travel motor 26. The travel driver 47 controls the amount of current supplied to the travel motor 26 based on a command signal from the control device 41. The travel driver 47 controls the amount of current supplied to the travel motor 26 based on information fed back from an encoder (external encoder or travel motor encoder) not shown. The travel driver 47 includes a drive circuit that supplies current to the travel motor 26.

[0071] The fork driver 48 is electrically connected to the fork motor 67 of the fork motor unit 66. The fork driver 48 controls the amount of current supplied to the fork motor 67 based on a command signal from the control device 41. The fork driver 48 controls the amount of current supplied to the fork motor 67 based on information fed back from an encoder (not shown) included in the fork motor unit 66. The fork driver 48 includes a drive circuit that supplies current to the fork motor 67.

[0072] The swivel driver 49 is electrically connected to the swivel motor 76 of the swivel motor unit 75. The swivel driver 49 controls the amount of current supplied to the swivel motor 76 based on a command signal from the control device 41. The swivel driver 49 also controls the amount of current supplied to the swivel motor 76 based on information fed back from an encoder 77 (not shown) included in the swivel motor unit 75. The swivel driver 49 includes a drive circuit that supplies current to the swivel motor 76.

[0073] In the article transport facility 100, the configuration of the stacker crane 1B is the same as that of the stacker crane 1A, except for some components. A part of the configuration of the stacker crane 1B that is different from that of the stacker crane 1A will be described. In the following description, the wheels of the traveling carriage 20 of the stacker crane 1B will be referred to as the first driving wheel 1B22, the second driving wheel 1B23, the first driven wheel 1B24, and the second driven wheel 1B25, respectively. In addition, the first side frame of the frames constituting the carriage frame 21 of the stacker crane 1B will be referred to as the first side frame 1B211, and the second side frame of the frames constituting the carriage frame 21 will be referred to as the second side frame 1B212. The configurations of each wheel 1B22-1B25 and the first side frame 1B211 and the second side frame 1B212 of the carriage frame 21 of the stacker crane 1B are different from the configurations of each wheel 22-25 and the first side frame 211 and the second side frame 212 of the carriage frame 21 of the stacker crane 1A.

[0074] The rails on which the first driving wheels 1B22 and the second driving wheels 1B23 of the traveling carriage 20 of the stacker crane 1B roll are different from the rails on which the first driving wheels 22 and the second driving wheels 23 of the traveling carriage 20 of the stacker crane 1A roll. That is, the first driving wheels 22 and the second driving wheels 23 of the stacker crane 1A roll on the upper surface of the traveling guide rail 3, and the first driving wheels 1B22 and the second driving wheels 1B23 of the stacker crane 1B roll on the upper surface of the traveling rail 4.

[0075] The first driving wheel 1B22 and the second driving wheel 1B23 are attached to the second side frame 1B212 of the traveling cart 20. Also, the first driven wheel 1B24 and the second driven wheel 1B25 of the stacker crane 1B are attached to the first side frame 1B211. The length in the left-right direction of the second side frame 1B212 to which the driving wheels are attached is longer than the length in the left-right direction of the first side frame 1B211 to which the driven wheels are attached. The first guide roller pair 28 and the second guide roller pair 29 of the stacker crane 1B are attached to the first side frame 211, similar to the first guide roller pair 28 and the second guide roller pair 29 of the stacker crane 1A.

[0076] Note that, like the stacker crane 1A, the cable 90 of the stacker crane 1B is connected in the front-rear direction from the rear of the traveling rail 4 to the traveling carriage 20 of the stacker crane 1B, centered on the traveling rail 4. However, this is not limited to the above configuration. The cable 90 of the stacker crane 1B may be connected in the front-rear direction from the front of the traveling guide rail 3 to the traveling carriage 20 of the stacker crane 1B, centered on the traveling guide rail 3.

[0077] [Detection by control device] The control device 41 detects that the first guide roller 281 of the first guide roller pair 28 has worn based on the horizontal distance detected by the first distance sensor 80A. The control device 41 also detects that the second guide roller 291 of the second guide roller pair 29 has worn based on the horizontal distance detected by the second distance sensor 80B.

[0078] Detection of wear of the guide rollers by the control device 41 will be described taking as an example a case where the first guide roller 281 of the first guide roller pair 28 is worn. Detection of wear of the second guide roller 291 of the second guide roller pair 29 by the control device 41 is performed in the same manner as detection of wear of the first guide roller 281 of the first guide roller pair 28 by the control device 41.

[0079] When any one of the pair of first guide rollers 281 is worn, the back and forth rattle of the traveling carriage 20 with respect to the traveling guide rail 3 becomes large. That is, the fluctuation of the distance between the first side frame 211 and the traveling guide rail 3 becomes large. For example, when the front first guide roller 281 is worn, the distance between the first side frame 211 and the traveling guide rail 3 detected by the first distance sensor 80A may become long. Also, when the rear first guide roller 281 is worn, the distance between the first side frame 211 and the traveling guide rail 3 detected by the first distance sensor 80A may become short. The control device 41 detects that any one of the pair of first guide rollers 281 is worn from the fluctuation of the horizontal distance detected by the first distance sensor 80A.

[0080] The first distance sensor 80A is provided near the first guide roller pair 28, and the second distance sensor 80B is provided near the second guide roller pair 29. This makes it possible to detect wear of the first guide roller of the first guide roller pair 28 and / or wear of the second guide roller of the second guide roller pair 29.

[0081] Furthermore, the control device 41 detects the inclination of the traveling cart 20 based on the horizontal distance detected by the first distance sensor 80A and the horizontal distance detected by the second distance sensor 80B. Specifically, the control device 41 detects the inclination of the traveling cart 20 in the front-rear direction relative to the traveling guide rail 3 when the traveling cart 20 is stopped based on the horizontal distance detected by the first distance sensor 80A and the horizontal distance detected by the second distance sensor 80B.

[0082] 9, a description will be given of the control by the control device 41 when the stopped traveling carriage 20 is inclined relative to the traveling guide rail 3. Fig. 9 is a schematic diagram illustrating the inclination of the traveling carriage 20, the lifting platform 30, and the fork section 60 relative to the traveling guide rail 3 when the stacker crane 1A is stopped.

[0083] The first guide roller 281 and the second guide roller 291 are elastic members, and therefore are distorted by a load applied in the front-rear direction. When the first guide roller 281 and / or the second guide roller 291 are distorted, the traveling cart 20 becomes inclined obliquely in the front-rear direction with respect to the traveling guide rail 3. As shown in FIG. 8, when the stacker crane 1A stops traveling, the traveling cart 20 may become inclined obliquely in the front-rear direction with respect to the traveling guide rail 3. When the traveling cart 20 becomes inclined in the front-rear direction with respect to the traveling guide rail 3, the lifting platform 30 also becomes inclined obliquely in the front-rear direction with respect to the traveling guide rail 3 in accordance with the inclination of the traveling cart 20.

[0084] The control device 41 calculates the inclination of the traveling cart 20 with respect to the traveling guide rail 3 based on the horizontal distance detected by the first distance sensor 80A and the horizontal distance detected by the second distance sensor 80B, and detects the inclination of the traveling cart 20. The control device 41 controls the swivel unit 70 according to the detected inclination of the traveling cart. Specifically, the control device 41 drives the swivel motor 76 to rotate the swivel frame 71 in the direction opposite to the direction of inclination of the traveling cart 20 in the front-rear direction with respect to the traveling guide rail 3. For example, when the traveling cart 20 is inclined in the direction indicated by the arrow A, the control device 41 rotates the swivel frame 71 in the direction indicated by the arrow B, thereby allowing the fork 61 of the fork unit 60 to move forward and backward vertically with respect to the shelf 2.

[0085] According to the above configuration, the first distance sensor 80A and the second distance sensor 80B can detect the inclination of the traveling carriage 20 with respect to the traveling guide rail 3. As a result, the first guide roller and / or the second guide roller is distorted, so that the inclination of the traveling carriage with respect to the traveling guide rail 3 can be accurately detected.

[0086] In addition, according to the above configuration, the drive of the swivel unit is controlled according to the inclination of the traveling carriage. Therefore, the fork unit is not tilted relative to the shelf due to the inclination of the traveling carriage when loading or unloading an article. This allows the article to be loaded or unloaded accurately from the shelf.

[0087] [Embodiment 2] Another embodiment of the present invention will be described below with reference to Figures 10 and 11. For ease of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals, and their explanation will not be repeated. Traveling carriage 20A of stacker crane 1A according to embodiment 2 differs from traveling carriage 20 of stacker crane 1A according to embodiment 1 in that first drive wheel 22A travels on traveling rail 4.

[0088] Fig. 10 is a plan view seen from above of a stacker crane 1A provided in an article transport equipment 100A according to embodiment 2. Fig. 11 is a cross-sectional view taken at the center position CL and line A-A shown in Fig. 10. Reference numeral 200 in Fig. 11 indicates a cross-sectional view taken at the center position CL in Fig. 10. Reference numeral 201 in Fig. 11 indicates a cross-sectional view taken at line A-A shown in Fig. 10.

[0089] As shown in FIG. 10, the first drive wheel 22A of the stacker crane 1A is attached to the second side frame 212A and rolls on the upper surface of the traveling rail 4. The first drive wheel 22A is located on the left end side of the second side frame 212A when viewed from the center position CL in the left-right direction of the carriage frame 21. The first drive wheel 22A is located to the left of the first connection frame 213 in the left-right direction. The first travel motor 26A of the stacker crane 1A is provided on the second side frame 212A. More specifically, the first travel motor 26A is located on the left end side of the second side frame 212A when viewed from the center position CL in the left-right direction of the carriage frame 21.

[0090] The first driven wheel 24A of the stacker crane 1A is attached to the first side frame 211A and rolls on the upper surface of the traveling guide rail 3. The first driven wheel 24A is located on the left end side of the first side frame 211A. The first driven wheel 24A is located to the right of the first driving wheel 22A in the left-right direction.

[0091] The first drive wheel 22A and the first travel motor 26A may be located on the right side of the second side frame 212A when viewed from the center position CL in the left-right direction of the carriage frame 21. In other words, the first drive wheel 22A and the second drive wheel 23 may be located at the same position on the left or right side in the left-right direction without being spaced apart in the left-right direction.

[0092] The first distance sensor 80A is attached at a position closer to the first driven wheel 24A than the second distance sensor 80B. A distance L1 between the first distance sensor 80A and the first guide roller pair 28 in the left-right direction is shorter than a distance L5 between the first distance sensor 80A and the first driven wheel 24A in the left-right direction. More specifically, the distance L5 is the distance between the first distance sensor 80A and the center of the rotation shaft of the first driven wheel 24A in the left-right direction.

[0093] A barcode reader 81A is attached to the first side frame 211A of the traveling cart 20A. The barcode reader 81A reads a barcode 83A attached to the front side surface of the traveling guide rail 3A. The barcode 83A includes position information that is information about the position in the longitudinal direction of the traveling guide rail 3A. The stacker crane 1A of this embodiment moves to each transfer position CP1 based on the position information read from the barcode 83A of the traveling guide rail 3A. Note that, instead of the barcode reader 81A, a reader that reads a scale attached to the side surface of the traveling guide rail 3A may be attached.

[0094] Moreover, power is supplied to the stacker crane 1A included in the article transport equipment 100A according to the second embodiment in a non-contact manner. As indicated by reference numeral 200 in FIG. 11, the article transport equipment 100A includes a guide wire 95. The guide wire 95 is arranged in parallel to the traveling rail 4. The guide wire 95 is an example of a power supply unit. Power is supplied to the guide wire 95 from a power supply panel (not shown).

[0095] A pickup coil 96 is attached to the traveling carriage 20A of the stacker crane 1A. The pickup coil 96 is an example of a power receiving unit. The pickup coil 96 is disposed to face the induction wire 95 with a gap therebetween. The pickup coil 96 receives power from the magnetic field generated by the induction wire 95.

[0096] As indicated by reference numeral 201 in FIG. 11, the traveling rail 4 is provided with a metallic earth rail 5. More specifically, the earth rail 5 extends forward from the lower end of the front side surface of the traveling rail 4. An earth roller 55 is attached to the second side frame 212A of the traveling cart 20A. The earth roller 55 is made of a conductive material. The earth roller 55 rolls on the upper surface of the earth rail 5. The earth roller 55 has a function as an earth, and is a roller that is additionally attached in addition to the wheels of the traveling cart 20A.

[0097] 〔summary〕 An item transport device according to a first aspect of the present invention includes a first wheel, a second wheel arranged at a distance from the first wheel in a running direction that is a direction along a guide rail, a first guide roller pair having a pair of first guide rollers that sandwich the guide rail in a direction intersecting the running direction, and a second guide roller pair having a pair of second guide rollers that sandwich the guide rail in a direction intersecting the running direction and arranged at a distance from the first guide roller pair in the running direction, a frame whose longitudinal direction is the running direction, and to which the first guide roller and the second guide roller are attached, a first sensor that detects the horizontal distance between the frame and the guide rail, and a first sensor arranged at a distance from the first sensor in the running direction, the frame and the guide rail. and a traveling carriage having a first guide roller pair and a second sensor that detects the horizontal distance between the first guide roller pair and the second sensor, wherein the first sensor and the second sensor are attached to the frame, the first guide roller pair is located closer to the first wheel than the second guide roller pair and the second sensor in the traveling direction, the first sensor is located closer to the first wheel than the second guide roller pair and the second sensor in the traveling direction, a distance between the first sensor and the first guide roller pair in the traveling direction is shorter than a distance between the first sensor and the first wheel in the traveling direction, and a distance between the second sensor and the second guide roller pair in the traveling direction is shorter than a distance between the second sensor and the second wheel in the traveling direction.

[0098] According to the article transport device of aspect 1, the first sensor is provided near the first guide roller pair, and the second sensor is provided near the second guide roller pair, making it possible to detect wear of the first guide roller of the first guide roller pair and / or wear of the second guide roller of the second guide roller pair.

[0099] The article transport device according to Aspect 2 of the present invention may be configured as in Aspect 1 above, wherein the first guide roller pair and the second guide roller pair are located between the first wheel and the second wheel in the traveling direction. According to the article transport device of Aspect 2, the first guide roller pair and the second guide roller pair are provided in the space between the first wheel and the second wheel. This allows the first guide roller pair and the second guide roller pair to be provided on the frame of the traveling cart without being restricted by other members.

[0100] The article transport device according to Aspect 3 of the present invention is the same as Aspect 1 or 2, wherein the first sensor and the second sensor are located between the first wheel and the second wheel in the traveling direction. According to the article transport device of Aspect 3, the first sensor and the second sensor may be attached to the space between the first wheel and the second wheel. This allows the first sensor and the second sensor to be attached to the frame of the traveling cart without being restricted by other members.

[0101] The article transport device according to Aspect 4 of the present invention is any one of Aspects 1 to 3 above, wherein the first wheel and the second wheel are drive wheels that are driven by power from a drive source. According to the article transport device of Aspect 4, the guide rail on which the first wheel and the second wheel, which are drive wheels, run is sandwiched between the first guide roller pair and the second guide roller pair. Therefore, the first guide roller pair and the second guide roller pair can make it easier for the traveling cart to move straight in the traveling direction. This can improve the straight-line traveling performance of the traveling cart.

[0102] The article transport device according to a fifth aspect of the present invention is any one of the first to fourth aspects above, further comprising a control unit that detects inclination of the traveling cart based on the horizontal distance detected by the first sensor and the horizontal distance detected by the second sensor. According to the article transport device of the fifth aspect, the inclination of the traveling cart with respect to the guide rail can be detected by the first sensor and the second sensor. As a result, the first guide roller and / or the second guide roller are distorted, so that the inclination of the traveling cart with respect to the guide rail can be accurately detected.

[0103] In the article transport device according to aspect 6 of the present invention, in any one of aspects 1 to 5 above, the first sensor and the second sensor are attached on opposite sides in the travel direction as viewed from a center position of the frame in the travel direction. According to the article transport device of aspect 6, it is possible to widen the interval between the first sensor located on one side of the center position of the frame in the travel direction and the second sensor located on the other side of the center position of the frame in the travel direction. This makes it possible to more accurately detect the inclination of the traveling cart with respect to the guide rail.

[0104] The item transport device of aspect 7 of the present invention, in accordance with aspect 5 or 6 above, further comprises a mast erected on the running cart, a lifting platform that is capable of being raised and lowered relative to the mast, a fork section mounted on the lifting platform and moving in forward and backward directions to load and unload items between the shelf and the lifting platform, and a rotating section that rotates the fork section, wherein the control section controls the drive of the rotating section in accordance with the inclination of the running cart detected by the detection results of the first sensor and the second sensor.

[0105] According to the article transport device of the seventh aspect, the drive of the swivel unit is controlled according to the inclination of the traveling carriage. Therefore, the fork unit is not tilted relative to the shelf due to the inclination of the traveling carriage when placing or removing an article. This allows the article to be placed or removed accurately from the shelf.

[0106] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0107] 1 Stacker crane 3 Travel guide rail 4 Running rail 10 Mast 20 Travelling cart 21 Truck frame 22 1st drive wheel 23 2nd drive wheel 28 First guide roller pair 29 Second guide roller pair 41 Control device 80 Distance Sensor 81 Barcode reader 100 Goods transport equipment 281 First guide roller 291 Second guide roller

Claims

1. A first wheel; A second wheel is disposed apart from the first wheel in a traveling direction that is a direction along the guide rail; a first guide roller pair including a pair of first guide rollers sandwiching the guide rail in a direction intersecting the traveling direction; a second guide roller pair including a pair of second guide rollers sandwiching the guide rail in a direction intersecting the traveling direction, the second guide roller pair being spaced apart from the first guide roller pair in the traveling direction; a frame having a longitudinal direction in the traveling direction, the frame to which the first guide roller and the second guide roller are attached; a first sensor for detecting a horizontal distance between the frame and the guide rail; a second sensor that detects a horizontal distance between the frame and the guide rail and is disposed apart from the first sensor in the traveling direction; the first sensor and the second sensor are attached to the frame; the first guide roller pair is located closer to the first wheel than the second guide roller pair and the second sensor in the traveling direction, and the first sensor is located closer to the first wheel than the second guide roller pair and the second sensor in the traveling direction, a distance between the first sensor and the first pair of guide rollers in the traveling direction is shorter than a distance between the first sensor and the first wheel in the traveling direction; An article transport device, wherein a distance between the second sensor and the second pair of guide rollers in the traveling direction is shorter than a distance between the second sensor and the second wheel in the traveling direction.

2. The article transport apparatus according to claim 1 , wherein the first pair of guide rollers and the second pair of guide rollers are located between the first wheel and the second wheel in the traveling direction.

3. The article transport apparatus according to claim 1 , wherein the first sensor and the second sensor are located between the first wheel and the second wheel in the travel direction.

4. The article transport device according to claim 1 , wherein the first wheel and the second wheel are drive wheels that are driven by power from a drive source.

5. The article transport apparatus according to claim 1 , further comprising a control unit that detects a tilt of the traveling cart based on the horizontal distance detected by the first sensor and the horizontal distance detected by the second sensor.

6. The article transport apparatus according to claim 5 , wherein the first sensor and the second sensor are attached on opposite sides in the travel direction when viewed from a center position in the travel direction of the frame.

7. A mast erected on the traveling carriage; A lift platform that is provided so as to be liftable and lowerable relative to the mast; A fork unit that is mounted on the lift platform and moves in a forward and backward direction to insert and remove items between the shelf and the lift platform; A pivoting unit that pivots the fork unit, The control unit is 7. The article transport device according to claim 6, further comprising: a control section for controlling the driving of the swivel section in response to an inclination of the traveling carriage detected by the detection results of the first sensor and the second sensor.

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