Item transport device

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 carriage provided in the article transport device. The traveling carriage has a pair of guide rollers that sandwich a rail on which the wheels of the traveling carriage roll from both sides. When the drive wheels of the traveling carriage are driven, the pair of guide rollers each roll on the side of the rail. This allows 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 the traveling carriage travels, each of the pair of guide rollers wears out. When the guide rollers wear out, the inclination of the traveling carriage relative to the rail increases. Therefore, wear of the guide rollers can be considered to cause a decrease in the straight-line movement 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 problem, 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 having the running direction as its longitudinal 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 sensor and a traveling carriage having 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 positioned closer to the first wheel than the second guide roller pair and the second sensor in the traveling direction, the first sensor is positioned closer to the first wheel than the second guide roller pair and the second sensor in the traveling direction, the distance between the first sensor and the first guide roller pair in the traveling direction is shorter than the distance between the first sensor and the first wheel in the traveling direction, and the distance between the second sensor and the second guide roller pair in the traveling direction is shorter than the distance between the second sensor and the second wheel in the traveling 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, which makes 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. [Effects 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 explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an example of an article conveying facility according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the stacker crane shown in FIG. [Figure 3] FIG. 3 is a perspective view of a traveling carriage provided in the stacker crane shown in FIG. 2. [Figure 4] 3 is a plan view of a traveling carriage provided in the stacker crane shown in FIG. 2, seen from above. [Figure 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 in the stacker crane shown in FIG. 2, viewed from the right side. [Figure 7] 3 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 the 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 portion relative to the traveling guide rail when the stacker crane is stopped. FIG. [Figure 10] FIG. 10 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. FIG. DETAILED DESCRIPTION OF THE INVENTION

[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 equipment 100 will be described with reference to Figure 1. Figure 1 is a schematic diagram showing an example of the article conveying equipment 100. For ease of explanation, the up-down direction, the front-rear direction, and the left-right direction are defined as shown by arrows in Figure 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 equipment 100 shown in Figure 1 comprises a stacker crane 1, a shelf 2, a traveling guide rail 3, and a traveling rail 4. The shelf 2 is a shelf on which articles can be placed. The shelf 2 has multiple levels in the vertical direction, and the space for placing articles is partitioned left and right on each level. Between the front shelf 2 and the rear shelf 2, the traveling guide rail 3 and traveling rail 4 that form the travel path of the stacker crane 1 are installed on the floor, allowing the stacker crane 1 to travel between the front shelf 2 and the rear shelf 2. The traveling guide rail 3 is an example of a guide rail. The traveling rail 4 is installed parallel to the traveling guide rail 3. The longitudinal direction of the traveling guide rail 3 and traveling rail 4 is the left and right direction.

[0013] Stacker crane 1 is a device that transports articles. Stacker crane 1 is an example of an article transport device. The vertical height of stacker crane 1 is approximately 2m to 18m. Stacker crane 1 travels along traveling guide rails 3. In this embodiment, the traveling direction D1 of stacker crane 1 is the left-right direction. In article transport equipment 100, multiple stacker cranes 1 travel on the same traveling guide rails 3 and traveling rails 4. Note that article transport equipment 100 may also be configured such that one stacker crane 1 travels on the traveling guide rails 3 and traveling rails 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 stacker cranes 1A and 1B are in a standby state where they are not transporting goods, they wait at their respective home positions HP1 and HP2. Home position HP1 of stacker crane 1A is located on the left side of traveling guide rail 3, and home position HP2 of stacker crane 1B is located on the right side of traveling guide rail 3. To the right of home position HP1 is provided an loading / unloading entrance EP1 through which goods are delivered to stacker crane 1A, and to the left of home position HP2 is provided an loading / unloading entrance EP2 through which goods are delivered to stacker crane 1B. Note that home position HP1 and loading / unloading entrance EP1 may be the same position, or home position HP2 and loading / unloading entrance EP2 may be the same position. Transfer position CP1 is a position where stacker crane 1A can take in and out goods from the front shelf 2 or the rear shelf 2, and transfer position CP2 is a position where stacker crane 1B can take in and 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 loaded or unloaded are placed. The transport position CP1 of stacker crane 1A is a position on the right side of the traveling guide rail 3 relative to the loading / unloading entrance EP1, and the transport position CP2 of stacker crane 1B is a position on the left side of the traveling guide rail 3 relative to the loading / unloading entrance EP2.

[0016] Stacker crane 1A moves to home position HP1, loading / unloading entrance EP1, or transfer position CP1 in accordance with the transfer command signal. Stacker crane 1B moves to home position HP2, loading / unloading entrance EP2, or transfer position CP2 in accordance with the transfer command signal. For example, when stacker crane 1A receives a transfer command signal to store an item in the fourth row from the left on the front shelf 2, stacker crane 1A receives the item from the storage conveyor at loading / unloading entrance EP2 and then moves to transfer position CP1 shown in FIG. 1. After stacker crane 1A completes storing the item on the front shelf 2 at transfer position CP1 shown in FIG. 1, stacker crane 1A moves to home position HP1, loading / unloading entrance EP1, or transfer position CP1 in accordance with the next transfer command signal. On the other hand, when stacker crane 1A receives a transfer command signal to retrieve an item placed in the fourth row from the left on the front shelf 2, stacker crane 1A moves to transfer position CP1 shown in FIG. 1. When the removal of the goods from the shelf 2 at the transfer position CP1 shown in Figure 1 is completed, the stacker crane 1A moves to the loading / unloading entrance EP1 and delivers the goods 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] Although the loading / unloading entrances EP1 and EP2 are located outside the shelves 2 in the travel direction, this is not a limitation. The loading / unloading entrances EP1 and EP2 may be located at positions that overlap with the shelves 2 in the travel direction. That is, the loading / unloading entrances EP1 and EP2 may be provided on either the front or rear shelves 2. In this case, the shelves 2 on which the loading / unloading entrances EP1 and EP2 are provided have openings that allow the delivery of goods. For example, the stacker crane 1A stops in front of the row of shelves 2 on which the loading / unloading entrance EP1 is provided. Furthermore, although the loading / unloading entrances EP1 and EP2 are different loading / unloading entrances, this is not a limitation. The loading / unloading entrance EP2 may be the same loading / unloading entrance as the loading / unloading entrance EP1.

[0018] [Stacker crane] Next, the 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 carriage 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) will be referred to as the first mast 10A, and the mast 10 on the right side of the drawing (the transfer position CP1 side) will be 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 lifting platform 30 (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 lifting guide rail 11. The lifting guide rail 11 guides the lifting platform 30 in the up-down direction.

[0021] An upper frame 12 is provided above the masts 10. The upper frame 12 is provided to connect the upper ends of the first masts 10A and the second masts 10B. The upper frame 12 engages with an upper rail (not shown) that is provided along the traveling guide rails 3. The upper frame 12 is also provided with guide rollers, and the guide rollers of the upper frame 12 guide the upper parts of the masts 10 along the upper rail. In other words, the upper ends of the masts 10 are guided in the traveling direction D1 by the upper rail. Note that the stacker crane 1A may not have an upper frame 12.

[0022] A lifting motor 13, which is a drive unit for raising and lowering the lifting platform 30 relative to the masts 10, is provided below each of the pair of masts 10. The lifting motor 13 is provided on the rear side of the masts 10, i.e., on the traveling rail 4 side of the masts 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 moves forward or backward from the drive drum. Pulleys that engage the lifting belt are 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 moves forward or backward. That is, the lifting platform 30 moves up and down relative to the mast 10 in the lifting direction D2 as driven by the lifting motor 13. Note that the lifting platform 30 may be raised and lowered relative to the mast 10 by a lifting wire or a lifting chain instead of a lifting belt.

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

[0025] The frames 211-214 that make up the bogie frame 21 do not have to be formed as a single unit, but may each 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. 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 the frames 211-214 separate members, a large stacker crane 1 can be delivered disassembled. This allows the stacker crane 1 to 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 connecting 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 connecting 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 connecting frame 213 is a frame whose longitudinal direction is the front-to-rear direction. As shown in Fig. 4, the first mast 10A is erected on the first connecting 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 side of the second side frame 212. The second connection frame 214 is a frame whose longitudinal direction is the front-to-rear direction. The second connection frame 214 faces the first connection frame 213 in the left-to-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 rails 3 and the traveling rails 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 on the left end side of the first side frame 211 when viewed from the center position CL of the bogie frame 21 in the left-right direction, and the second drive wheel 23 is located on the right end side of the first side frame 211 when viewed from the center position CL. The first drive wheel 22 is located to the left of the first connecting frame 213 in the left-right direction. The second drive wheel 23 is located to the right of the second connecting 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 when viewed from the center position CL in the left-right direction of the bogie frame 21, and the second driven wheel 25 is located on the right end side of the second side frame 212 when 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 travel motors 26, which are drive units for driving the stacker crane 1A. In the following description, the travel motor 26 on the left side (towards home position HP1) will be referred to as the first travel motor 26A, and the travel motor 26 on the right side (towards transfer position CP1) will be 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 wheels 22. The second travel motor 26B is located at the right end of the first side frame 211 and drives the second drive wheels 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 spaced 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 drive wheel 22 than the second guide roller pair 29 in the left-right direction. Furthermore, the first guide roller pair 28 is located closer to the first drive 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 drive wheel 22 and the second drive 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 connecting frame 213 when viewed from the center position CL of the bogie frame 21 in the left-right direction. 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-to-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 connecting frame 214 when viewed from the center position CL of the bogie frame 21 in the left-right direction. 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-to-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 carriage 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. This causes the stacker crane 1A to travel in the traveling direction D1.

[0038] According to the above configuration, the travel guide rail 3 on which the first drive wheel 22 and the second drive 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 carriage to travel straight in the traveling direction D1. This improves the straight-line traveling performance of the traveling carriage.

[0039] As shown in FIG. 3, a plurality of distance sensors 80 are attached to the first side frame 211 of the traveling carriage 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-to-rear direction between the first side frame 211 and the traveling guide rail 3. An example of the distance sensors 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) will be referred to as the first distance sensor 80A, and the distance sensor 80 on the right side of the drawing (transport position CP1 side) will be referred to as the second distance sensor 80B. The first distance sensor 80A is an example of a first sensor, and the second distance sensor 80B is an example of a second sensor.

[0041] 4, the first distance sensor 80A and the second distance sensor 80B are located between the first drive wheel 22 and the second drive wheel 23 in the left-right direction. More specifically, the first distance sensor 80A and the second distance sensor 80B are located 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 drive wheel 22 and the second drive wheel 23, the first distance sensor 80A and the second distance sensor 80B can be attached to the space between the first drive wheel 22 and the second drive wheel 23. This allows the first distance sensor 80A and the second distance sensor 80B to be attached to the frame of the traveling carriage 20 without being restricted by other members.

[0042] The first distance sensor 80A may be located between the first drive 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 drive 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 drive wheel 22 than the second distance sensor 80B in the left-right direction. The first distance sensor 80A is also located closer to the first drive 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 of the center position CL of the bogie frame 21 in the left-right direction. The first distance sensor 80A is located on the left side of the center position CL of the first side frame 211 in the left-right direction, and the second distance sensor 80B is located on the right side of the center position CL of the first side frame 211 in the left-right direction.

[0044] According to the above configuration, the distance 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, thereby enabling more accurate detection of the inclination of the traveling carriage with respect to the guide rail.

[0045] The first distance sensor 80A is attached at a position closer to the first drive 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 drive 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. Furthermore, the distance L2 is the distance between the first distance sensor 80A and the center of the rotation shaft of the first drive 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 drive 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 drive wheel 23 in the left-right direction.

[0047] As shown in Figures 3 and 4, a barcode reader 81 is attached to the second side frame 212 of the traveling carriage 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. In other words, the barcode reader 81 is attached to the traveling carriage 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 illustrating 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 that 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 on 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 Cableveyor (registered trademark) and moves as the stacker crane 1A travels. The cable 90 is connected to the traveling carriage 20 from one of two areas defined around the traveling rail 4 in a direction perpendicular to the traveling direction D1 in a top view, the area opposite the area where the traveling guide rail 3 is located. In other words, 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] [Elevator] The detailed configuration of the lifting platform 30 will be described with reference to Figures 5 and 6. Figure 5 is a plan view of the lifting platform 30 provided in the stacker crane 1A shown in Figure 2, viewed from above. Figure 6 is a cross-sectional view of the lifting platform 30 provided in the stacker crane 1A shown in Figure 2, viewed from the right side.

[0052] The 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 platform 30 has a 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 platform frame 31.

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

[0054] The fork section 60 places an item M in and out between the shelf 2 and the lifting platform 30. The fork section 60 is provided on a swivel frame 71 of the swivel 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 item 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 in the longitudinal direction of the first arm 63. In other words, the first arm 63 is provided on one end 641 in the longitudinal direction of the second arm 64. The first arm 63 rotates relative to the second arm 64 about a 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 / backward direction D4. The driving force of the fork motor 67 is transmitted to the second arm 64, causing it to rotate about a rotation axis A3 relative to the lifting platform 30.

[0058] A plurality of fork motor units 66 are provided. Each fork motor unit 66 includes a fork motor 67 and an encoder (not shown). When the fork motor 67 rotates forward or backward, the pair of second arms 64 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 forward or backward, the pair of first arms 63 also move forward or backward. 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 forward or backward, the fork 61 moves forward or backward together with the gear box 65. In this embodiment, the forward / backward direction D4 of the fork 61 of the fork section 60 is the forward / backward direction.

[0059] The swivel unit 70 rotates relative to the lifting 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 a 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 lifting platform 30, the fork portion 60 rotates in a rotation direction D3 relative to the lifting 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 taken out of the 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 or take out an article M on or from the shelf 2 in the rear of the stacker crane 1A.

[0062] The cable box 37 is a box that collects cables for connecting various devices such as sensors mounted on the lifting platform 30 with devices located outside the lifting platform 30. The cable box 37 is located on the left side of the lifting platform 30 (the side toward the home position HP1). The cable box 37 collects cables that communicate signals with the fork motor unit 66 and the swing motor unit 75 mounted on the lifting platform 30. A connector plate is located on the cable box 37, on which a connector to which a lifting cable is connected is installed. The connector of the cable box 37 is connected to a connector installed on the connector plate of the driver box 45 by a lifting 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 Figure 8. Figure 8 is a block diagram showing the electrical configuration of the stacker crane 1A shown in Figure 2. As shown in Figure 8, the control device 41 is made up of a computer equipped with a processor such as a CPU (Central Processing Unit), a memory such as RAM or 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 swivel 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 swivel driver 49 that controls the power supplied to the swivel motor 76 so that information can be communicated.

[0066] The control device 41 controls each of the drivers 46 to 49. Specifically, the control device 41 transmits a command signal to each of the drivers 46 to 49 to control the operation of each of the drivers 46 to 49. More specifically, the control device 41 transmits a position command to each of the drivers 46 to 49. Each of the drivers 46 to 49 outputs electric power to be supplied to each of the motors 13, 26, 67, and 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 carriage 20 based on the signal obtained from the distance sensor 80. The control device 41 obtains the 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 the 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-to-rear direction. The driver box 45 houses 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 arranged 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 lift cables (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 (not shown) (an external encoder or a travel motor encoder). 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) provided in the fork motor unit 66. The fork driver 48 includes a drive circuit that supplies current to the fork motor 67.

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

[0073] In the article transport equipment 100, the configuration of the stacker crane 1B is the same as that of the stacker crane 1A, with some exceptions. The following describes some of the configuration of the stacker crane 1B that differs from that of the stacker crane 1A. In the following description, the wheels of the traveling carriage 20 of the stacker crane 1B are referred to as the first drive wheel 1B22, the second drive wheel 1B23, the first driven wheel 1B24, and the second driven wheel 1B25, respectively. Furthermore, of the frames that make up the carriage frame 21 of the stacker crane 1B, the first side frame is referred to as the first side frame 1B211, and the second side frame of the frames that make up the carriage frame 21 is referred to as the second side frame 1B212. The configurations of each wheel 1B22 to 1B25 and the first side frame 1B211 and second side frame 1B212 of the carriage frame 21 of the stacker crane 1B are different from the configurations of each wheel 22 to 25 and the first side frame 211 and second side frame 212 of the carriage frame 21 of the stacker crane 1A.

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

[0075] The first drive wheel 1B22 and the second drive wheel 1B23 are attached to the second side frame 1B212 of the traveling carriage 20. Furthermore, 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 drive 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] Like the stacker crane 1A, the cable 90 of the stacker crane 1B is connected in the front-to-rear direction from the rear of the traveling rail 4 to the traveling carriage 20 of the stacker crane 1B, with the traveling rail 4 as the center. However, the present invention is not limited to this configuration. The cable 90 of the stacker crane 1B may also be connected in the front-to-rear direction from the front of the traveling guide rail 3 to the traveling carriage 20 of the stacker crane 1B, with the traveling guide rail 3 as the center.

[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 guide rollers by the control device 41 will be described using an example in which 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 either of the pair of first guide rollers 281 is worn, the back and forth rattle of the traveling carriage 20 relative to the traveling guide rail 3 increases. That is, the fluctuation in the distance between the first side frame 211 and the traveling guide rail 3 increases. 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 increase. 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 decrease. The control device 41 detects that either of the pair of first guide rollers 281 is worn from the fluctuation in 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 carriage 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 carriage 20 in the front-to-rear direction relative to the traveling guide rail 3 when the traveling carriage 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 will be distorted by a load applied in the front-to-rear direction. When the first guide roller 281 and / or the second guide roller 291 are distorted, the traveling carriage 20 will be inclined obliquely in the front-to-rear direction relative to the traveling guide rail 3. As shown in FIG. 8, when the stacker crane 1A stops traveling, the traveling carriage 20 may be inclined obliquely in the front-to-rear direction relative to the traveling guide rail 3. When the traveling carriage 20 is inclined in the front-to-rear direction relative to the traveling guide rail 3, the lifting platform 30 will also be inclined obliquely in the front-to-rear direction relative to the traveling guide rail 3 in accordance with the inclination of the traveling carriage 20.

[0084] The control device 41 calculates the inclination of the traveling carriage 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 carriage 20. The control device 41 controls the swivel unit 70 in accordance with the detected inclination of the traveling carriage. Specifically, the control device 41 drives the swivel motor 76 to rotate the swivel frame 71 in the direction opposite to the direction of the inclination of the traveling carriage 20 in the front-to-rear direction with respect to the traveling guide rail 3. For example, if the traveling carriage 20 is inclined in the direction indicated by arrow A, the control device 41 rotates the swivel frame 71 in the direction indicated by arrow B, thereby allowing the forks 61 of the fork unit 60 to move forward and backward perpendicular 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] Furthermore, with the above configuration, the drive of the swivel unit is controlled according to the inclination of the traveling carriage. Therefore, items are not placed or removed from the shelf when the fork unit is tilted relative to the shelf due to the inclination of the traveling carriage. This allows items to be placed or removed 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 embodiments will be given the same reference numerals, and their description 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 wheels 22A travel on traveling rails 4.

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

[0089] As shown in Figure 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 of the carriage frame 21 in the left-right direction. The first drive wheel 22A is located on the left side 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 of the carriage frame 21 in the left-right direction.

[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 travel 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 drive 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 bogie 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 carriage 20A. The barcode reader 81A reads a barcode 83A attached to the front side surface of the traveling guide rail 3A. The barcode 83A contains 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 on 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] Furthermore, 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 is provided with 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 so as 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 , a metallic earth rail 5 is provided on the traveling rail 4. More specifically, the earth rail 5 extends forward from the lower end of the front side of the traveling rail 4. An earth roller 55 is attached to the second side frame 212A of the traveling carriage 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 functions as an earth and is an additional roller attached separately from the wheels of the traveling carriage 20A.

[0097] 〔summary〕 An article 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, 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 having the running direction as its longitudinal 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 that is arranged at a distance from the first sensor in the running direction, the frame and the guide rail and a second sensor that detects the horizontal distance between the first sensor and the second sensor, wherein the first sensor and the second sensor are attached to the frame, the first guide roller pair is positioned closer to the first wheel than the second guide roller pair and the second sensor in the traveling direction, the first sensor is positioned closer to the first wheel than the second guide roller pair and the second sensor in the traveling direction, the distance between the first sensor and the first guide roller pair in the traveling direction is shorter than the distance between the first sensor and the first wheel in the traveling direction, and the distance between the second sensor and the second guide roller pair in the traveling direction is shorter than the distance between the second sensor and the second wheel in the traveling direction.

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

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

[0100] An article transport device according to Aspect 3 of the present invention is the same as Aspect 1 or 2 above, 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 carriage without being restricted by other members.

[0101] An 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 carriage to move straight in the traveling direction. This can improve the straight-line movement performance of the traveling carriage.

[0102] The article transport apparatus according to a fifth aspect of the present invention is the same as in any of the first to fourth aspects, and further includes a control unit that detects the inclination of the traveling carriage based on the horizontal distance detected by the first sensor and the horizontal distance detected by the second sensor. According to the article transport apparatus of the fifth aspect, the inclination of the traveling carriage 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, and the inclination of the traveling carriage with respect to the guide rail can be accurately detected.

[0103] In an article transport device according to a sixth aspect of the present invention, in any one of the first to fifth aspects, the first sensor and the second sensor are attached on opposite sides of the frame in the travel direction when viewed from a center position in the travel direction. According to the article transport device of the sixth aspect, it is possible to widen the distance between the first sensor located on one side of the center position in the travel direction of the frame and the second sensor located on the other side of the center position in the travel direction of the frame. This makes it possible to more accurately detect the inclination of the traveling carriage 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 traveling carriage, a lifting platform that is capable of rising and falling relative to the mast, a fork section mounted on the lifting platform and moving in a forward and backward direction to load and unload items between the shelf and the lifting platform, and a swivel section that rotates the fork section, and the control section controls the drive of the swivel section in accordance with the inclination of the traveling carriage detected by the detection results of the first sensor and the second sensor.

[0105] According to the article transport device of aspect 7, the drive of the swivel unit is controlled in accordance with 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 Traveling cart 21 Bogie frame 22 First drive wheel 23 Second 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 disposed apart from the first wheel in a traveling direction that is a direction along the guide rail; a first guide roller pair having 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, 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 is disposed apart from the first sensor in the traveling direction and detects a horizontal distance between the frame and the guide rail; 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, and the first sensor is located closer to the first wheel than the second guide roller pair and the second sensor in the running 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 apparatus, wherein the distance between the second sensor and the second pair of guide rollers in the travel direction is shorter than the distance between the second sensor and the second wheel in the travel 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 travel 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 an inclination of the traveling carriage based on the horizontal distance detected by the first sensor and the horizontal distance detected by the second sensor.

6. 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 of the frame in the travel direction.

7. a mast erected on the traveling carriage; a lifting platform that is provided so as to be able to rise and fall relative to the mast; a fork unit that is mounted on the platform and moves forward and backward to load and unload items between the shelf and the platform; A pivoting unit that pivots the fork unit, The control unit 7. The article transport device according to claim 6, wherein the driving of the swivel unit is controlled in accordance with the tilt of the traveling carriage detected by the detection results of the first sensor and the second sensor.

Images