Pallet transport vehicle

Abstract

To realize a pallet transport vehicle that can correct the tilt of pallets with a simple configuration. [Solution] A pallet transport vehicle 10 comprises a fork 15 that supports a pallet P from below, a lifting device for raising and lowering the fork 15, a vehicle body 30 that supports the fork 15 and the lifting device, and wheels that support the vehicle body 30, wherein a guide member 50 is provided that, during an approach operation in which the vehicle body 30 is moved relative to the pallet P so as to insert the fork 15 below Z2 below the article-holding surface of the pallet P that supports the articles to be placed on the pallet P, contacts the rear surface Pr facing the rear X2 of the pallet P from the rear X2 to correct the inclination of the rear surface Pr of the pallet P with respect to the width direction Y.

Description

Technical Field

[0001] The present invention relates to a pallet carrier equipped with forks.

Background Art

[0002] Japanese Patent Laid-Open No. 03-088699 (Patent Document 1) describes a forklift equipped with a swing arm (8) for correcting the displacement in the width direction of a pallet. This swing arm (8) has an intermediate part (9) that can rotate horizontally, and a pair of guide rollers (12, 13) are provided before and after the intermediate part (9), respectively. The interval between the pair of front guide rollers (12) is configured to be wider than the interval between the pair of rear guide rollers (13) by the biasing of a spring (18).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The forklift of Patent Document 1 has a complicated structure because it includes a swing arm having a plurality of spring-biased guide rollers. Also, when there are multiple types of pallet sizes, it is necessary to replace or adjust the swing arm.

[0005] Therefore, it is desired to realize a pallet carrier that can correct the inclination of a pallet with a simple structure.

Means for Solving the Problems

[0006] The pallet transport vehicle according to this disclosure comprises a fork that supports a pallet from below, a lifting device for raising and lowering the fork, a vehicle body that supports the fork and the lifting device, and wheels that support the vehicle body, wherein the vehicle includes a guide member that, during an approach operation in which the vehicle body is moved toward the pallet so that the fork is inserted below the article-holding surface that supports the articles to be placed on the pallet, with the extension direction of the fork being the front-rear direction, the direction perpendicular to the front-rear direction in an up-down view being the width direction, the side of the fork from the base end to the tip in the front-rear direction being the front, and the opposite side being the rear, the guide member that contacts the rear surface of the pallet facing the rear from the rear to correct the inclination of the rear surface of the pallet with respect to the width direction.

[0007] With this configuration, the approaching motion of the pallet transport vehicle can be used to bring the guide member into contact with the rear surface of the pallet, thereby correcting the tilt of the pallet relative to the forks. Therefore, the tilt of the pallet can be corrected and the pallet supported by the forks with a simple configuration.

[0008] Further features and advantages of the technology relating to this disclosure will become clearer from the following description of exemplary and non-limiting embodiments, with reference to the drawings. [Brief explanation of the drawing]

[0009] [Figure 1] A perspective view of the pallet transport vehicle according to the first embodiment, viewed from the rear. [Figure 2] Figure 1 is a perspective view of a pallet transport vehicle seen from the front. [Figure 3] Side view of the pallet transport vehicle in Figure 1. [Figure 4] Figure 1: Underside view of the pallet transport vehicle [Figure 5] Figure 2 is a top view showing the state before the contact portion of the guide member comes into contact with the pallet. [Figure 6] Figure 2 is a top view showing the state after the contact portion of the guide member has come into contact with the pallet. [Figure 7]Top view showing the state after the pallet's tilt has been corrected by the guide member shown in Figure 2. [Figure 8] Top view of a pallet transport vehicle according to the second embodiment [Modes for carrying out the invention]

[0010] The following describes an embodiment of the pallet transport vehicle 10 with reference to the drawings.

[0011] [First Embodiment] In the following description, the pallet transport vehicle 10 according to the first embodiment will be explained with reference to the drawings. Figure 1 is a schematic diagram showing an example of the rear view of the pallet transport vehicle 10. Figure 2 is a schematic diagram showing an example of the front view of the pallet transport vehicle 10. The pallet transport vehicle 10 is used in facilities such as warehouses, factories, and ships.

[0012] The pallet transport vehicle 10 transports pallets P by traveling on a travel surface 11. The pallet transport vehicle 10 may travel on a travel surface 11 provided on a frame, or it may travel on rails provided on the travel surface 11. In this embodiment, the travel surface 11 on which the pallet transport vehicle 10 travels is the floor. Examples of the pallet transport vehicle 10 include a manned transport vehicle, an unmanned transport vehicle, an autonomous transport vehicle, a transport vehicle operated by remote control, etc. In this embodiment, the pallet transport vehicle 10 is an autonomous unmanned transport vehicle.

[0013] Figure 3 is a schematic diagram showing an example of a side view of a pallet transport vehicle 10. The pallet transport vehicle 10 is equipped with forks 15 that support the pallet P from below Z2. In this embodiment, an insertion opening Pb into which the forks 15 are inserted is provided below Z2 from the article placement surface Pa that supports the article W to be placed on the pallet P. The forks 15 are branched into multiple forks. In this embodiment, the forks 15 are branched into two forks. Note that the forks 15 may be a single flat plate-shaped member. In this embodiment, the upper surface of the pallet P is the article placement surface Pa.

[0014] Let the extending direction of the fork 15 be the front-rear direction X. Let the direction orthogonal to the front-rear direction X in the up-down direction view be the width direction Y. Let the side from the base end side to the tip end side of the fork 15 in the front-rear direction X be the front side X1. Let the opposite side of the front side X1 be the rear side X2. In the present embodiment, a base end face 15b extending in the direction along the up-down direction Z is provided at the base end of the fork 15.

[0015] The pallet P is provided with a plurality (two in the present embodiment) of insertion ports Pb. In the example shown in FIG. 3, both the upper side Z1 and the lower side Z2 of the insertion port Pb of the pallet P are plate-shaped. Note that the insertion port Pb of the pallet P may not be a hole shape and may be a concave shape without a plate on the lower side Z2. Also, the pallet P may be placed on a mounting table, and after inserting the fork 15 into a groove provided in the mounting table and then raising it, the pallet P may be supported from the lower side Z2. In such a case, the pallet P may not have the insertion port Pb.

[0016] As shown in FIG. 3, the pallet transporter 10 includes a lifting device 20 for lifting and lowering the fork 15. The lifting device 20 includes a winding member 21 connected to the fork 15. The lifting device 20 includes a guiding member 22 for guiding the fork 15 in the direction along the up-down direction Z. The lifting device 20 includes a guided member 23 connected to the fork 15 and guided along the up-down direction Z by the guiding member 22.

[0017] The lifting device 20 includes a lifting support portion 25 for supporting the fork 15. The lifting support portion 25 is disposed inside the width direction Y with respect to the pair of guiding members 22 and supports the pair of guided members 23. In the present embodiment, the lifting support portion 25 supports the pair of guided members 23 rotatably. In the present embodiment, the winding member 21 is connected to the lifting support portion 25. In the present embodiment, the lifting support portion 25 connects the pair of forks 15.

[0018] The pallet transporter 10 includes a vehicle body 30 that supports the forks 15 and the lifting device 20. The vehicle body 30 includes a vehicle body main body portion 31 disposed on the rear side X2 with respect to the forks 15. The vehicle body 30 includes a pair of leg portions 32 spaced apart outward in the width direction Y with respect to the forks 15. In the present embodiment, the vehicle body main body portion 31 supports the forks 15 and the lifting device 20.

[0019] The pair of leg portions 32 are formed so as to protrude forward X1 from the vehicle body main body portion 31. By providing the pair of leg portions 32 in this way, the dimension in the front-rear direction X of the vehicle body main body portion 31 can be shortened as compared with, for example, the case where the vehicle body main body portion 31 is enlarged to stabilize the balance of the pallet transporter 10.

[0020] FIG. 4 is a schematic view showing an example of the bottom surface of the pallet transporter 10. The pallet transporter 10 includes wheels that support the vehicle body 30. The wheels include a first wheel 36 and a second wheel 37. In the present embodiment, the wheels include at least a pair of first wheels 36 and at least a pair of second wheels 37. The pair of first wheels 36 support the vehicle body main body portion 31. The pair of second wheels 37 support the pair of leg portions 32. In the present embodiment, two second wheels 37 are attached to each of the pair of leg portions 32.

[0021] The pallet transporter 10 is rotatable about a vehicle body rotation axis C2 along the vertical direction Z. In the present embodiment, the vehicle body rotation axis C2 passes through the intermediate position of the pair of second wheels 37. In the illustrated example, the vehicle body rotation axis C2 passes through the central position between the pair of second wheels 37, that is, the position equidistant from each of the second wheels 37.

[0022] The pallet transport vehicle 10 is equipped with a wheel drive source 41. The wheel drive source 41 drives at least one of a pair of first wheels 36 and a pair of second wheels 37. In this embodiment, the pair of first wheels 36 are the drive wheels of the pallet transport vehicle 10. In this embodiment, the pair of second wheels 37 are the driven wheels of the pallet transport vehicle 10. The pallet transport vehicle 10 is equipped with a pair of wheel drive sources 41 so that each of the pair of first wheels 36 can be driven independently.

[0023] The vehicle body 31 is equipped with a rotatable support section 42. The rotatable support section 42 supports the first wheel 36 so as to be rotatable around a pivot axis C1 along the vertical direction Z. In this embodiment, the first wheel 36 and the wheel drive source 41 are rotatably supported around a pivot axis C1 along the vertical direction Z.

[0024] The pair of wheel drive sources 41 drive the pair of first wheels 36 so that they rotate at the same speed and in opposite directions, thereby causing the pair of first wheels 36 to rotate around the pivot axis C1. The rotation trajectory T1 shown in Figure 4 is the rotation trajectory of the first wheels 36 around the pivot axis C1.

[0025] The pallet transport vehicle 10 is equipped with a path-changing device 40 that changes the direction of travel of the vehicle body 31. In this embodiment, the path-changing device 40 comprises a wheel drive source 41 and a rotation support section 42. The wheel drive source 41 and the rotation support section 42 cause a pair of first wheels 36 to rotate around a rotation axis C1, thereby changing the direction of travel of the vehicle body 31.

[0026] The vehicle body 30 is equipped with a cover 30b that covers at least the upper Z1 of the pivot support portion 42. In this embodiment, the cover 30b is configured to cover at least the upper Z1 of the lifting device 20, the first wheel 36, the wheel drive source 41, the pivot support portion 42, and the control device 80, which will be described later. In Figures 5 to 8, which will be described later, the cover 30b is omitted.

[0027] Figure 5 is a schematic diagram showing an example of the upper surface of the guide member 50. The pallet transport vehicle 10 is equipped with the guide member 50. The guide member 50 is located on the outside of the fork 15 in the width direction Y and on the inside of the leg portion 32.

[0028] The movement of the vehicle body 30 relative to the pallet P so as to insert the forks 15 below Z2 below the item placement surface Pa that supports the item W to be placed on the pallet P is defined as "approaching movement". Figure 5 shows the state during approaching movement when the guide member 50 is not in contact with the rear surface Pr of the pallet P.

[0029] The guide member 50 contacts the rear surface Pr of the pallet P, which faces the rear X2, from the rear X2 during the approaching motion, thereby correcting the inclination of the rear surface Pr of the pallet P with respect to the width direction Y. In this embodiment, the inclination of the rear surface Pr of the pallet P with respect to the width direction Y is corrected by the movement of the vehicle body 30 relative to the pallet P, which presses the guide member 50 against the rear surface Pr of the pallet P.

[0030] In this embodiment, the tilt correction by the guide member 50 is performed during the approach operation in which the vehicle body 30 is moved relative to the pallet P supported by the running surface 11. In this embodiment, the pallet P is supported by the running surface 11 by being placed on the running surface 11. Alternatively, the pallet P may be supported by the running surface 11 by being placed on a mounting platform on the running surface 11.

[0031] The guide member 50 is positioned below Z2 the item placement surface Pa of the pallet P during approach operation. In this embodiment, the guide member 50 is fixed at a position below Z2 the item placement surface Pa of the pallet P placed on the travel surface 11.

[0032] The portion that comes into contact with the rear surface Pr of the pallet P during approach is defined as the contact portion 50e. In this embodiment, the front surface X1 of the guide member 50 is the contact portion 50e. In this embodiment, the contact portion 50e is a contact surface parallel to the width direction Y. As shown in Figure 3, the contact portion 50e is positioned below Z2 of the article placement surface Pa on the pallet P during approach.

[0033] In this embodiment, the guide member 50 is fixed at a position in the vertical Z direction relative to the vehicle body 30. At least the front end X1 of the upper surface of the guide member 50 has an inclined surface 51 that slopes downward Z2 as it moves toward the front X1. The inclined surface 51 is formed above Z1 above the contact portion 50e. In this embodiment, the upper surface of the guide member 50 is an inclined surface 51 that slopes downward Z2 as it moves toward the front X1.

[0034] As shown in Figure 5, the guide members 50 are arranged in pairs spaced apart in the width direction Y. In this embodiment, the guide members 50 are arranged in pairs on both sides of the fork 15 in the width direction Y. The contact portion 50e of the guide member 50 is positioned to contact the portion of the rear surface Pr of the pallet P that is outside the insertion opening Pb of the pallet P in the width direction Y.

[0035] Figure 6 shows an example where the contact portion 50e is in contact with the rear surface Pr of the pallet P, and the inclination of the rear surface Pr of the pallet P with respect to the width direction Y is not corrected. Figure 7 shows an example where the guide member 50 is in contact with the rear surface Pr of the pallet P, and the inclination of the rear surface Pr of the pallet P with respect to the width direction Y is corrected.

[0036] At a point X1 in front of the contact portion 50e of the guide member 50, the leg portion 32 is positioned below Z2 from the article placement surface Pa on the pallet P. The contact portion 50e of the guide member 50 is positioned below Z2 from the upper surface 32a of the leg portion 32 at a point X1 in front of the contact portion 50e of the guide member 50.

[0037] The contact portion 50e and inclined surface 51 of the guide member 50 are positioned X1 in front of the base end surface 15b of the fork 15. The contact portion 50e and inclined surface 51 of the guide member 50 are positioned X1 in front of the lifting support portion 25 of the lifting device 20.

[0038] In this embodiment, as shown in Figure 7, both of the pair of guide members 50 are in contact with the rear surface Pr of the pallet P, but the forks 15, the lifting device 20, and the vehicle body 30 do not come into contact with the rear surface Pr of the pallet P. In this embodiment, as shown in Figure 6, the guide members 50 are in contact with the rear surface Pr of the pallet P, but the forks 15, the lifting device 20, and the vehicle body 30 do not come into contact with the rear surface Pr of the pallet P.

[0039] The guide member 50 guides the pallet P to a predetermined position in the front-rear direction X. Examples of predetermined positions include the position where the pallet transport vehicle 10 raises the pallet P with the forks 15, the position where the pallet transport vehicle 10 lowers the pallet P with the forks 15, and the position where the pallet transport vehicle 10 supports the pallet P with the forks 15 while in motion.

[0040] A contact sensor 52 is provided on the contact portion 50e for detecting contact with the pallet P. In this embodiment, a contact sensor 52 is provided on the contact portion 50e of each of the pair of guide members 50 that abuts against the rear surface Pr of the pallet P for detecting contact with the pallet P.

[0041] As shown in Figure 1, the pallet transport vehicle 10 is equipped with a control device 80. In this embodiment, the control device 80 controls the drive wheels (first wheels 36 in this embodiment). In this embodiment, the control device 80 controls the path changing device 40. In this embodiment, the control device 80 controls the lifting device 20.

[0042] The control device 80 includes an arithmetic processing unit such as a CPU (Central Processing Unit) and a main memory that the arithmetic processing unit can access, such as RAM (Random Access Memory) and ROM (Read Only Memory). Each function of the control device 80 is realized through the cooperation of the hardware provided by the control device 80 and the program executed on the hardware such as the arithmetic processing unit. In this embodiment, the control device 80 (specifically, the arithmetic processing unit provided by the control device 80) functions as a computer.

[0043] The control device 80 may be entirely mounted on the pallet transport vehicle 10, or a part of the control device 80 may be mounted on the pallet transport vehicle 10 and the other part may be located in an external facility, such as an external server like a cloud server. In these cases, it is possible to appropriately change which part of the control device 80 is mounted on the pallet transport vehicle 10 and which part is located outside the pallet transport vehicle 10.

[0044] During approach operation, if one of the pair of contact sensors 52 detects contact with pallet P and the other does not, the control device 80 controls the path changing device 40 so that the side that does not detect contact becomes forward X1 compared to the side that does detect contact. Figure 6 shows the state in which one of the pair of contact sensors 52 detects contact with pallet P and the other does not detect contact with pallet P.

[0045] The control device 80 stops the movement of the vehicle body 30 when both of the pair of contact sensors 52 detect contact with the pallet P during the approach operation. After both of the pair of contact sensors 52 detect contact with the pallet P during the approach operation, the control device 80 raises the fork 15 to support the pallet P from below Z2. Figure 7 shows the state when both of the pair of contact sensors 52 detect contact with the pallet P.

[0046] [Second Embodiment] The following description will focus on the differences between the second embodiment and the first embodiment. Unless otherwise specified, the second embodiment is the same as the first embodiment.

[0047] Figure 8 is a schematic diagram showing an example of the upper surface of the guide member 50 in this embodiment. In this embodiment, the guide member 50 moves up and down together with the fork 15 by the lifting device 20. In this embodiment, the guide member 50 is supported by the lifting support part 25.

[0048] [Other Embodiments] Next, other embodiments of the pallet transport vehicle 10 will be described.

[0049] (1) In the above embodiment, a configuration in which the first wheel 36 is a drive wheel and the second wheel 37 is a driven wheel was described as an example. However, the embodiment of the pallet transport vehicle 10 is not limited to such a configuration. For example, the second wheel 37 may be a drive wheel. Also, for example, both the first wheel 36 and the second wheel 37 may be driven wheels, and the pallet transport vehicle 10 may be moved by a worker or another vehicle. Also, for example, the approach operation may be an operation in which the vehicle body 30 is moved relative to the pallet P by moving the pallet P with a conveyor or the like.

[0050] (2) In the above embodiment, a configuration was described as in which the guide member 50 is positioned below Z2 the article placement surface Pa on the pallet P during approach operation. However, the embodiment of the pallet transport vehicle 10 is not limited to such a configuration. For example, a part of the guide member 50 may be positioned above Z1 the article placement surface Pa on the pallet P during approach operation. For example, the contact portion 50e may be positioned below Z2 the article placement surface Pa and the inclined surface 51 may be positioned below Z2 the article placement surface Pa.

[0051] (3) In the above embodiment, a configuration was described in which a pair of guide members 50 are arranged on both sides of the fork 15 in the width direction Y, and the contact portion 50e is a contact surface parallel to the width direction Y. However, the embodiment of the pallet transport vehicle 10 is not limited to such a configuration. For example, one or both of the pair of guide members 50 may be provided between the pair of forks 15. Also, multiple contact portions 50e may be provided, and each contact portion 50e may be a curved or polygonal surface when viewed in the vertical direction.

[0052] (4) In the above embodiment, the guide members 50 are arranged in pairs spaced apart in the width direction Y, and a configuration was described as one in which both of the pair of guide members 50 are in contact with the rear surface Pr of the pallet P, while the forks 15, the lifting device 20, and the vehicle body 30 are not in contact with the rear surface Pr of the pallet P. However, the embodiment of the pallet transport vehicle 10 is not limited to such a configuration. For example, a configuration in which only one of the pair of guide members 50 is arranged may be in contact with the rear surface Pr of the pallet P, while a part of the forks 15, the lifting device 20, or the vehicle body 30 is also in contact with the rear surface Pr of the pallet P to temporarily adjust the position of the pallet P.

[0053] (5) In the above embodiment, the pallet transport vehicle 10 is provided with a control device 80 that controls the lifting device 20, the drive wheels, and the path changing device 40, and the control device 80 is configured to stop the movement of the vehicle body 30 when both of the pair of contact sensors 52 detect contact with the pallet P during approach operation. However, embodiments of the pallet transport vehicle 10 are not limited to such a configuration. For example, the control device 80 may be configured to raise the forks 15 without stopping the movement of the vehicle body 30 when both of the pair of contact sensors 52 detect contact with the pallet P during approach operation. Alternatively, for example, the control device 80 may not control any of the lifting device 20, the drive wheels, or the path changing device 40. Alternatively, for example, the pallet transport vehicle 10 may not have a control device 80 and may be operated manually.

[0054] (6) In the above embodiment, the control device 80 was described as having a configuration in which, during approach operation, if one of the pair of contact sensors 52 detects contact with the pallet P and the other does not detect contact with the pallet P, the side that does not detect contact becomes the front X1 compared to the side that does detect contact. However, the embodiment of the pallet transport vehicle 10 is not limited to such a configuration. For example, in the above case, the control device 80 may have a configuration in which the drive wheels move the vehicle body 30 to the front X1 until the contact sensor 52 on the side that does not detect contact detects contact. Also, for example, instead of a pair of contact sensors 52 being provided, only one may be provided.

[0055] (7) In the above embodiment, an example was described in which an inclined surface 51 is formed on at least the front end X1 of the upper surface of the guide member 50, and the inclined surface is inclined toward the lower Z2 as it moves toward the front X1. However, the embodiment of the pallet transport vehicle 10 is not limited to such a configuration. For example, the inclined surface 51 may not be formed on the upper surface of the guide member 50.

[0056] (8) The configurations disclosed in the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the spirit of this disclosure.

[0057] [Summary of the above embodiments] The following describes the pallet transport vehicle related to this disclosure.

[0058] In one embodiment, the pallet transport vehicle comprises a fork that supports the pallet from below, a lifting device for raising and lowering the fork, a vehicle body that supports the fork and the lifting device, and wheels that support the vehicle body, wherein the extending direction of the fork is the front-rear direction, the direction perpendicular to the front-rear direction in an up-and-down view is the width direction, the side of the fork from the base end to the tip in the front-rear direction is the front, and the opposite side is the rear, and the vehicle body is moved toward the pallet so as to insert the fork below the article-holding surface that supports the articles to be placed on the pallet, the vehicle is equipped with a guide member that contacts the rear-facing rear surface of the pallet from the rear to correct the inclination of the rear surface of the pallet with respect to the width direction.

[0059] With this configuration, the approaching motion of the pallet transport vehicle can be used to bring the guide member into contact with the rear surface of the pallet, thereby correcting the tilt of the pallet relative to the forks. Therefore, the tilt of the pallet can be corrected and the pallet supported by the forks with a simple configuration.

[0060] In one embodiment, the guide member is positioned below the surface on which the article is placed on the pallet during the approach operation.

[0061] With this configuration, even if the item to be placed on the item placement surface of the pallet protrudes further back than the rear surface of the pallet, the guide member can be prevented from interfering with the item.

[0062] In one embodiment, the guide members are arranged in pairs on both sides of the fork in the width direction.

[0063] With this configuration, a pair of guide members, positioned separately in the width direction, contact the rear surface of the pallet to correct the pallet's tilt, thus enabling high-precision correction of the pallet's tilt.

[0064] In one embodiment, the guide members are arranged in pairs spaced apart in the width direction, and both of the pair of guide members are in contact with the rear surface of the pallet, while the forks, the lifting device, and the vehicle body are not in contact with the rear surface of the pallet.

[0065] With this configuration, the pair of guide members contact the rear surface of the pallet to correct the pallet's tilt without the forks, lifting device, or vehicle body coming into contact with the rear surface of the pallet, thus allowing for proper correction of the pallet's tilt.

[0066] In one embodiment, the vehicle comprises a drive wheel as the wheel, a path-changing device for changing the direction of travel of the vehicle body, and a control device for controlling the drive wheel and the path-changing device, wherein the guide members are arranged in pairs spaced apart in the width direction, and a contact sensor for detecting contact with the pallet is provided on the contact portion of each of the pair of guide members that abuts against the rear surface of the pallet, and the control device stops the movement of the vehicle body when both of the pair of contact sensors detect contact with the pallet during the approach operation.

[0067] With this configuration, it is possible to appropriately detect when both of the pair of guide members are in contact with the rear surface of the pallet, and the movement of the vehicle can be stopped when both of the pair of guide members are in contact with the rear surface of the pallet. This allows for proper correction of the pallet's tilt and prevents the pallet transport vehicle from pushing the pallet too hard.

[0068] In one embodiment, during the approach operation, if one of the pair of contact sensors detects contact with the pallet and the other does not detect contact with the pallet, the control device controls the path-changing device so that the side that does not detect contact is in front of the side that does detect contact.

[0069] With this configuration, both of the pair of guide members can be quickly brought into contact with the rear surface of the pallet.

[0070] In one embodiment, the guide member is fixed in a vertical position relative to the vehicle body, and an inclined surface is formed on the front end of the upper surface of the guide member, which is inclined downward as it moves towards the front.

[0071] With this configuration, even if the rear end of the underside of the pallet comes into contact with the guide member when the pallet is lowered by the fork, the inclined surface can move the pallet forward, correcting the position of the rear surface of the pallet to the proper position.

[0072] In one embodiment, the guide member is configured to move up and down together with the fork by the lifting device.

[0073] With this configuration, even if the height of the forks when inserting into the pallet during the approach operation varies each time, the guide member can properly correct the tilt of the pallet.

[0074] The pallet transport vehicle described herein only needs to achieve at least one of the effects described above. The technical features of the pallet transport vehicle described herein are also applicable to pallet transport methods and pallet transport programs. [Explanation of Symbols]

[0075] 10: Pallet transport vehicle 15: Fork 20: Lifting device 30: Vehicle body 32a:Top surface 36: First wheel (wheel, drive wheel) 37: 2nd wheel (wheel) 40: Lane change device 50: Guide member 50e: Contact part 51: Inclined surface 52: Contact Sensor 80: Control device P: Palette Pa: Surface on which items are placed Pr: Rear W: Items to be placed

Claims

1. A fork that supports the pallet from below, A lifting device for raising and lowering the fork, A vehicle body that supports the fork and the lifting device, Wheels supporting the aforementioned vehicle body, A pallet transport vehicle equipped with, The extension direction of the fork is defined as the front-rear direction, the direction perpendicular to the front-rear direction when viewed from above is defined as the width direction, the side of the fork from the base end to the tip in the front-rear direction is defined as the front side, and the opposite side is defined as the rear side. A pallet transport vehicle is provided with a guide member that, during an approach operation in which the vehicle body is moved toward the pallet such that the forks are inserted below the article-holding surface that supports the articles to be placed on the pallet, contacts the rear-facing rear surface of the pallet from the rear, thereby correcting the inclination of the rear surface of the pallet with respect to the width direction.

2. The pallet transport vehicle according to claim 1, wherein the guide member is positioned below the article placement surface on the pallet during the approach operation.

3. The pallet transport vehicle according to claim 1, wherein the guide members are arranged in pairs on both sides in the width direction relative to the fork.

4. The guide members are arranged in pairs, spaced apart in the width direction. The pallet transport vehicle according to claim 1, wherein both of the pair of guide members are in contact with the rear surface of the pallet, and the forks, the lifting device, and the vehicle body are not in contact with the rear surface of the pallet.

5. The vehicle comprises a drive wheel as the wheel, a direction-changing device for changing the direction of travel of the vehicle body, and a control device for controlling the drive wheel and the direction-changing device. The guide members are arranged in pairs, spaced apart in the width direction. A contact sensor for detecting contact with the pallet is provided on the contact portion of each of the pair of guide members that abuts against the rear surface of the pallet. The pallet transport vehicle according to claim 1, wherein the control device stops the movement of the vehicle body when both of the pair of contact sensors detect contact with the pallet during the approach operation.

6. The pallet transport vehicle according to claim 5, wherein the control device controls the path-changing device so that, during the approach operation, if one of the pair of contact sensors detects contact with the pallet and the other does not detect contact with the pallet, the side that does not detect contact is further forward than the side that does detect contact.

7. The guide member is fixed in a vertical position relative to the vehicle body. A pallet transport vehicle according to any one of claims 1 to 6, wherein an inclined surface is formed at the front end of the upper surface of the guide member, which is inclined downward as it approaches the front.

8. The pallet transport vehicle according to any one of claims 1 to 6, wherein the guide member is raised and lowered together with the fork by the lifting device.

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