Transport vehicle

Abstract

To provide a carrier that easily suppresses shaking or tilting of the carrier due to article transfer operation.SOLUTION: Transfer machines H1, H2 each comprising a holding part which holds an article are configured to move the article along a transfer direction crossing a front-rear direction of a carrier body when viewed from a vertical direction to transfer the article between the holding part and a shelf part 80. When an elevation body 40B is positioned above a predetermined reference height h within an elevation range of the elevation body 40B, a control part executes acceleration limiting control to make an upper limit of acceleration for the article movement along the transfer direction with the transfer machines H1, H2 lower than when the elevation body 40B is positioned below the reference height h.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a transport vehicle that travels along the front of a storage shelf that has multiple shelves arranged vertically for storing articles, and transports the articles. [Background technology]

[0002] Conventionally, this type of transport vehicle is provided with a transfer device for transferring articles onto and from storage shelves.

[0003] For example, the transfer device (2) disclosed in Japanese Patent No. 6337706 (Patent Document 1) includes a load placement section (26) on which a load (10) is placed, and a slide arm (28) having a top section (42) that moves back and forth in the direction of transfer of the load (10). The transfer device (2) is configured to perform a loading operation to transfer the load (10) from the load placement section (26) to the racks (12a, 12b) and a scooping operation to transfer the load (10) from the racks (12a, 12b) to the load placement section (26) by utilizing the reciprocating movement of the top section (42) of the slide arm (28). Note that the reference numerals in parentheses above are those of Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6337706 Summary of the Invention [Problem to be solved by the invention]

[0005] In a transport vehicle equipped with the above-described transfer device, an inertial force is generated in the direction of transfer as an item is transferred, which may cause the transport vehicle to sway or tilt. If the transfer vehicle sways or tilts too much, the positional relationship between the item, the shelf, and the transfer device may change, which may cause problems with the transfer operation.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and has as its object to realize a transport vehicle that can easily minimize shaking and tilting of the transport vehicle caused by the operation of transferring articles. [Means for solving the problem]

[0007] In view of the above, one aspect of the transport vehicle is as follows: a transport vehicle that travels along a front of a storage shelf having a plurality of shelves in a vertical direction for storing items, and transports the items, the transport vehicle comprising: a travelling body that travels along a travelling path; a transfer device that transfers the items; and a control unit that controls the transfer device, wherein the transfer device comprises a mast fixed to the travelling body and arranged along the vertical direction, a lifting body that rises and falls along the mast, and a transfer machine supported on the lifting body, the direction in which the travelling body travels is the front-rear direction of the vehicle body, and the transfer machine has a holding unit that holds the items, and is configured to move the items along a transfer direction that intersects the front-rear direction of the vehicle body as viewed in the vertical direction, and transfer the items between the holding unit and the shelves, and the control unit performs acceleration limiting control to lower an upper limit of acceleration of movement of the items along the transfer direction by the transfer machine when the lifting body is located above a predetermined reference height in a lifting range of the lifting body compared to when the lifting body is located below the reference height. The upper limit of the moving speed of the article along the transfer direction by the transfer machine is set to be the same above and below the reference height. .

[0008] If the swaying or tilting of the transport vehicle increases due to the transfer operation, the relative positions of the items, shelves, and transfer machine will change, causing a decrease in the accuracy of the transfer operation.To prevent this decrease in accuracy, it was necessary to wait for the swaying or tilting of the transport vehicle to subside before proceeding with the transfer operation. However, with this configuration, it is easy to minimize the shaking and tilting of the transport vehicle caused by the item transfer operation. Therefore, it is possible to prevent a decrease in the accuracy of the transfer operation, reduce the need to wait for the transfer operation, and improve the efficiency of the transfer operation. In this way, with this configuration, it is possible to realize a transport vehicle that easily minimizes the shaking and tilting of the transport vehicle caused by the item transfer operation. Furthermore, the acceleration of the goods affects the swaying and tilting of the transport vehicle during the goods transfer operation. With this configuration, the swaying and tilting of the transport vehicle can be reduced by limiting the acceleration. Furthermore, since the upper limit of the goods movement speed is the same in the area above and below the reference height, the efficiency of the transfer operation can be improved compared to when the upper limit of the goods movement speed in the upper area is limited lower than in the lower area.

[0009] In one embodiment, a transport vehicle in consideration of the above is a transport vehicle that travels along a front of a storage shelf having a plurality of shelves in a vertical direction for storing items to transport the items, and includes a travel body that travels along a travel path, a transfer device that transfers the items, and a control unit that controls the transfer device, and the transfer device includes a mast that is fixed to the travel body and arranged along the vertical direction, a lifting body that rises and falls along the mast, and a transfer machine supported by the lifting body, and the direction in which the travel body travels is the front-rear direction of the vehicle body, and the transfer machine includes a holding unit that holds the item, a locking unit that locks with the item, a moving mechanism that moves the locking unit in the transfer direction, and a control unit that moves the holding unit out and back in the transfer direction. and an ejection / withdrawal mechanism, and is configured to move the item along a transfer direction that intersects the fore-and-aft direction of the vehicle body when viewed in a vertical direction, thereby transferring the item between the holding section and the shelf section, wherein when the lifting body is positioned above a predetermined reference height in the lifting range of the lifting body, the control section executes acceleration limiting control to limit the upper limit of acceleration of the movement of the item along the transfer direction by the transfer machine to a lower value than when the lifting body is positioned below the reference height, and executes the acceleration limiting control for the movement of the item associated with the ejection / withdrawal operation of the holding section by the ejection / withdrawal mechanism, and does not execute the acceleration limiting control for the movement of the item associated with the movement of the engaging section by the moving mechanism.

[0010] According to this configuration, the acceleration limiting control is performed only for the exit / entrance operation, which has a large effect on the swaying and tilting of the transport vehicle, and the acceleration limiting control is not performed for the movement of the locking part by the moving mechanism, which has a relatively small effect on the swaying and tilting of the transport vehicle, so the efficiency of the transfer operation can be improved compared to when the acceleration limiting control is performed for both of these. Therefore, the efficiency of the transfer operation can be improved while effectively suppressing the swaying and tilting of the transport vehicle.

[0011] In one embodiment, a transport vehicle in consideration of the above is a transport vehicle that travels along the front of a storage shelf having a plurality of shelves arranged in a vertical direction for storing items to transport the items, and includes a travel body that travels along a travel path, a transfer device that transfers the items, and a control unit that controls the transfer device, and the transfer device includes a mast that is fixed to the travel body and arranged along the vertical direction, a lifting body that rises and falls along the mast, and a transfer machine supported by the lifting body, and the direction in which the travel body travels is the front-rear direction of the vehicle body, and the transfer machine holds the items. The transport vehicle is configured to have a holding unit that moves the item along a transfer direction that intersects the fore-and-aft direction of the vehicle body when viewed in the vertical direction, thereby transferring the item between the holding unit and the shelf unit, and when the lifting body is located above a predetermined reference height in the lifting range of the lifting body, the control unit executes acceleration limiting control that limits the upper limit of acceleration of the movement of the item by the transfer machine along the transfer direction to a lower value compared to when the lifting body is located below the reference height, and the reference height is set to a height corresponding to the height of the center of gravity of the transport vehicle.

[0012] As a result of verification by the inventors, it was found that movement of the transport vehicle in the direction of transferring an item above the center of gravity has a greater effect on the swaying and tilting of the transport vehicle than movement of the transport vehicle in the direction of transferring an item below the center of gravity. According to this configuration, the upper limit of the acceleration of movement of the transport vehicle in the direction of transferring an item above the center of gravity is limited to be lower than the upper limit of the acceleration of movement of the transport vehicle in the direction of transferring an item below the center of gravity, so that it is possible to minimize the swaying and tilting of the transport vehicle caused by the operation of transferring an item while minimizing the decrease in efficiency of the operation of transferring an item.

[0013] Further features and advantages of the techniques according to the present disclosure will become more apparent from the following description of exemplary and non-limiting embodiments, which proceeds with reference to the drawings. [Brief explanation of the drawings]

[0014] [Figure 1] Plan view of a transport facility equipped with transport vehicles [Figure 2] Front view of container shelf [Figure 3] View of the transport vehicle from the width direction [Figure 4] An explanatory diagram showing the structure of the running body [Figure 5] FIG. 10 is a plan view showing the first and second positions of the transfer device; [Figure 6] FIG. 10 is an explanatory diagram showing the scooping operation of the container relative to the shelf portion. [Figure 7] FIG. 10 is an explanatory diagram showing the operation of unloading a container from the shelf portion. [Figure 8] Diagram showing the reference height [Figure 9] Graph for explaining acceleration limiting processing [Figure 10] FIG. 10 is an explanatory diagram showing a reference height in another embodiment. [Figure 11] Graph for explaining acceleration limiting processing in another embodiment [Figure 12] Graph for explaining acceleration limiting processing in another embodiment DETAILED DESCRIPTION OF THE INVENTION

[0015] The transport vehicle transports items by traveling along the front of a storage shelf that has multiple vertically arranged shelves for storing items. Below, an embodiment of the transport vehicle will be described, taking as an example a case where the transport vehicle is installed in a transport facility that transports containers. That is, in this embodiment, the containers correspond to the "items," and the container shelves that store the containers correspond to the "storage shelves."

[0016] As shown in Fig. 1, the transport equipment F includes a container shelf 8 that stores containers 70 (see Fig. 3), and a loading / unloading section 9 that loads and unloads the containers 70. The transport vehicle 100 transports the containers 70 that have been loaded by the loading / unloading section 9 to the container shelf 8, or transports the containers 70 stored on the container shelf 8 to the loading / unloading section 9 for unloading.

[0017] In this embodiment, multiple container shelves 8 are arranged parallel to one another at specified intervals. Each of the multiple container shelves 8 is open at least at the front, and containers 70 are loaded and unloaded from this front. A portion of the travel route R of the traveling body 1 (transport vehicle 100) is set between a pair of adjacent container shelves 8 whose front faces each other. Furthermore, the container shelf 8 located at the extreme end of the multiple container shelves 8 provided in the transport equipment F is arranged with its front facing outward, and a portion of the travel route R is also set in the area along the front of the container shelf 8 at that end. Furthermore, the transport equipment F is provided with multiple loading and unloading sections 9, and a portion of the travel route R is also set in the area passing through each of the multiple loading and unloading sections 9.

[0018] The travel path R includes an intra-shelf path Ra that extends along the front of a container shelf 8 in the extension direction of the container shelf 8, and an extra-shelf path Rb that is set outside the arrangement area of ​​the container shelf 8. The intra-shelf path Ra is set corresponding to each of the multiple container shelves 8. In this embodiment, a portion of the travel path R that is set in the area between a pair of adjacent container shelves 8 whose front faces face each other, and a portion of the travel path R that is set in the area along the front of a container shelf 8 that is arranged with its front face facing outward, correspond to the intra-shelf path Ra. In addition, the extra-shelf path Rb is set to connect the multiple intra-shelf paths Ra. In addition, the extra-shelf path Rb is also set to pass through each of the multiple loading / unloading sections 9. In this embodiment, the portion of the travel path R other than the intra-shelf path Ra corresponds to the extra-shelf path Rb.

[0019] [Container shelf] 2, the container shelf 8 has multiple vertically arranged shelf sections 80 for storing containers 70. In this embodiment, the container shelf 8 has multiple beam members 82 extending horizontally along the front surface of the container shelf 8, and multiple support members 81 extending vertically and connected to each of the multiple beam members 82.

[0020] A mounting member 83 for placing a container 70 on is connected to each of the multiple beam members 82. In this example, the container 70 is stored in the shelf section 80 by being placed on the pair of mounting members 83. Furthermore, multiple pairs of mounting members 83 are arranged on the shelf section 80, so that one shelf section 80 can store multiple containers 70. In this example, the area between a pair of support members 81 adjacent in the width direction (left-right direction) when viewed from the front as shown in FIG. 3 and between a pair of beam members 82 adjacent in the vertical direction corresponds to the opening of the container shelf 8.

[0021] In this embodiment, a target portion 82T serving as a target for storing the container 70 at a reference position 80P for storing the container 70 on the shelf portion 80 is provided. In this example, the target portion 82T is provided on the beam member 82. One target portion 82T is provided for each pair of mounting members 83. In the example shown, the target portion 82T is configured by a hole formed in the beam member 82.

[0022] 〔container〕 The container 70 is an object to be transported by the transport vehicle 100. Although detailed illustration is omitted, the container 70 is formed in a box shape with an opening that opens upward. In this example, the outer shape of the container 70 when viewed from above is rectangular. The container 70 is capable of containing a specified amount of objects. The objects to be contained include, for example, various commodities such as food and household goods, or parts and work-in-progress used in factory production lines, etc.

[0023] In this embodiment, the container 70 is configured so that it can be stacked on another container 70 while containing an object therein. That is, the containers 70 are configured so that they can be stacked vertically (see FIG. 3). In this example, the bottom of the container 70 fits into the opening of the other container 70 from above, thereby stacking the two containers 70 vertically.

[0024] [Transport vehicle] 3, the transport vehicle 100 includes a travelling body 1 that travels along a specified travelling route R, a transfer device 4 that transfers containers 70, and a control unit C that controls the transfer device 4. In this embodiment, the transport vehicle 100 includes a container group support unit 2 that supports a plurality of containers 70 as a stacked container group 7 within a specified stacking area 2A, and a lifting device 3 that lifts the containers 70 of the container group 7 supported by the container group support unit 2. The control unit C controls the transfer device 4 as well as the travelling body 1, the container group support unit 2, and the lifting device 3.

[0025] The container group support unit 2, lifting device 3, and transfer device 4 are mounted on a running body 1. If the direction in which the running body 1 travels is defined as the "vehicle body longitudinal direction L," the container group support unit 2 and transfer device 4 are arranged side by side in the vehicle body longitudinal direction L on the running body 1. Note that, hereinafter, the direction perpendicular to the vehicle body longitudinal direction L when viewed from the top-down direction is defined as the "vehicle body width direction W." Here, the vehicle body longitudinal direction L and the vehicle body width direction W are horizontal directions that are perpendicular to each other.

[0026] Furthermore, as shown in Figures 3 and 4, when the dimension of the transport vehicle 1 in the fore-and-aft direction L of the vehicle body is defined as the length dimension Sl, the dimension of the vehicle body 1 in the width direction W of the vehicle body is defined as the width dimension Sw, and the height dimension Sh is defined as the height from the lower end of the vehicle body 1 to the upper ends of a pair of transfer masts 40 described later, the width dimension Sw is less than half the length dimension and the height dimension Sh is more than twice the width dimension Sw. In this embodiment, the height dimension Sh corresponds to the "vertical dimension from the bottom end of the traveling body to the top end of the mast."

[0027] The control unit C controls each functional unit of the transport vehicle 100. In this example, the control unit C controls the traveling body 1, the container group support unit 2, the lifting device 3, the transfer device 4, and the swivel device 5, which will be described later. The operation for transporting and transferring the container 70 is realized by the control of each functional unit by the control unit C. The control unit C includes, for example, a processor such as a microcomputer, peripheral circuits such as a memory, etc. Then, each function is realized by cooperation between this hardware and a program executed on a processor of a computer or the like.

[0028] [Traveling vehicle] The traveling body 1 is configured to travel on a traveling path R (see FIG. 1). In this embodiment, the traveling body 1 is configured to travel on an intra-shelf path Ra and an extra-shelf path Rb. When traveling on the intra-shelf path Ra, the traveling body 1 is configured to travel along the container shelf 8, and more specifically, is configured to travel along the front of the container shelf 8. In this embodiment, the traveling body 1 is configured to travel on the floor surface.

[0029] The running body 1 includes a running main body 10, a plurality of running wheels 11 connected to the running main body 10, and a running drive unit 11M that drives at least one of the plurality of running wheels 11. The running drive unit 11M includes a motor (not shown). The running drive unit 11M drives the running wheels 11, thereby imparting a propulsive force to the running body 1.

[0030] As shown in Fig. 5, in this embodiment, a pair of drive wheels 11a are provided in the central region of the traveling main body 10 in the vehicle body longitudinal direction L, spaced apart in the vehicle body width direction W. The pair of drive wheels 11a are driven by separate traveling drive units 11M. In addition, driven wheels 11b are provided on both sides of the pair of drive wheels 11a in the vehicle body longitudinal direction L.

[0031] In this embodiment, the length dimension Sl is the length dimension of the traveling main body 10 in the vehicle body fore-and-aft direction L (see FIG. 3), and the width dimension Sw is the dimension of the traveling main body 10 in the vehicle body width direction W (see FIG. 4). The width of the traveling body 1 (traveling main body 10) is set according to the longitudinal dimension of the container 70 so that the container 70 fits within the width of the traveling body 1 (traveling main body 10) even when the container 70 is rotated by the transfer device 4 as described below.

[0032] The above-described configuration allows the running object 1 to rotate around an axis that runs vertically on the spot. Specifically, the pair of drive wheels 11a are driven to rotate in opposite directions (directions indicated by arrows in FIG. 4), causing the running object 1 to rotate around an axis that runs vertically on the spot. This allows the running object 1 to change its direction of travel within a relatively narrow area.

[0033] [Container group support part] As shown in FIG. 3, the container group support section 2 is mounted on a traveling body 1. The container group support section 2 is configured to be able to support a plurality of containers 70 as a stacked container group 7. A stacking area 2A in which the container group 7 is arranged is defined above the container group support section 2. The stacking area 2A is a three-dimensional virtual area extending upward from the container group support section 2. In this example, the container group support section 2 is configured as a conveyor that can move the container group 7 while the container group 7 is placed thereon. In this example, the container group support section 2 is capable of moving the container group 7 along the vehicle width direction W. The conveyor that constitutes the container group support section 2 may be a well-known conveyor such as a roller conveyor, chain conveyor, or belt conveyor.

[0034] A container group 7, in which multiple containers 70 are stacked, is carried into the carry-in / out section 9 (see FIG. 1 ). With the traveling body 1 adjacent to the carry-in / out section 9, the container group support section 2 receives the container group 7 from the carry-in / out section 9 or delivers the container group 7 to the carry-in / out section 9. In other words, the container group support section 2 is configured to deliver the container group 7 to and from the carry-in / out section 9. Although detailed illustration is omitted, in this example, the carry-in / out section 9 is adjacent to a picking area where items, such as commodities, are removed from the containers 70. When the container group 7 is delivered from the container group support section 2 to the carry-in / out section 9, the items are removed from the containers 70 in a picking area adjacent to the carry-in / out section 9. After some or all of the items contained in the containers 70 have been removed, the containers 70 are delivered from the carry-in / out section 9 to the container group support section 2 (transport vehicle 100) and transported back to the container shelf 8. However, the loading / unloading section 9 does not have to be adjacent to the picking area, and may be adjacent to other equipment or a work area. Also, for example, the loading / unloading section 9 may be configured to transport the container group 7 delivered from the container group support section 2 to the outside of the transport equipment F.

[0035] [Lifting device] The lifting device 3 is mounted on the traveling body 1. The lifting device 3 is configured to lift the containers 70 of the container group 7 supported by the container group support portion 2, in other words, the containers 70 of the container group 7 arranged in the stacking area 2A.

[0036] The lifting device 3 includes a lifting mast 30 erected above the running body 1, a lifting body 30B connected to the lifting mast 30, and a lifting body drive unit 30M that raises and lowers the lifting body 30B along the lifting mast 30. Although detailed illustration is omitted, the lifting body drive unit 30M includes, for example, an endless body such as a belt connected to the lifting body 30B, a rotating body around which the endless body is wound, and a motor that rotates and drives the rotating body.

[0037] The lifting device 3 includes a first lifting mechanism 31 that lifts a container 70 of any height among the group of containers 7 stacked in the stacking area 2A relative to the adjacent container 70 below that container 70, and a second lifting mechanism 32 that lifts a container 70 below the container 70 lifted by the first lifting mechanism 31 relative to the adjacent container 70 below that container 70. In this embodiment, the first lifting mechanism 31 and the second lifting mechanism 32 are arranged spaced apart in the vertical direction. This makes it possible to form a vertical space between the container 70 lifted by the first lifting mechanism 31 and the container 70 lifted by the second lifting mechanism 32, although this is not shown in the drawings. Furthermore, it is possible to form a vertical space below the container 70 lifted by the second lifting mechanism 32.

[0038] Although details will be omitted, in this embodiment, when a space is formed vertically between the container 70 lifted by the first lifting mechanism 31 and the container 70 lifted by the second lifting mechanism 32, it is possible to place another container 70 in that space. Furthermore, when a space is formed vertically below the container 70 lifted by the second lifting mechanism 32, it is possible to use that space to scoop up a container 70 placed below the container 70 lifted by the second lifting mechanism 32.

[0039] [Transfer device] As shown in FIG. 3, the transfer device 4 is mounted on the traveling body 1. The transfer device 4 is configured to transfer a container 70 to a transfer target location T. The transfer device 4 is configured to perform a unloading operation to transfer the container 70 to the transfer target location T, and a scooping operation to transfer the container 70 from the transfer target location T. In this specification, the transfer of the container 70 from the transfer target location T to the transfer device 4 is referred to as "scooping," and "scooping" is not limited to a specific transfer operation. In this embodiment, the transfer target location T includes the stacking area 2A and the shelf portion 80 of the container shelf 8.

[0040] In this embodiment, the transport vehicle 100 is equipped with a swivel device 5 that rotates the transfer device 4 about an axis along the vertical direction. As shown in FIG. 5 , the swivel device 5 is configured to rotate the transfer device 4 (more specifically, a part of the transfer device 4) about an axis along the vertical direction to change the orientation of the transfer device 4 between a first position P1 when the transfer target location T is the stacking area 2A and a second position P2 when the transfer target location T is a container shelf 8 (shelf portion 80). In this example, the swivel device 5 is equipped with a swivel base 50 that supports the transfer device 4 (more specifically, a part of the transfer device 4), a swivel shaft 51 that rotatably supports the swivel base 50 relative to the transfer lift 40B, and a swivel drive unit 5M that drives the swivel shaft 51. As described above, in this embodiment, the moving direction of the container 70 transferred by the transfer device 4 can be changed within a horizontal plane by the swivel device 5.

[0041] The movement direction of the container 70 transferred by the transfer device 4 when the orientation of the transfer device 4 is in the first position P1 is referred to as the "first transfer direction Xa," ​​and the movement direction of the container 70 transferred by the transfer device 4 when the orientation of the transfer device 4 is in the second position P2 is referred to as the "second transfer direction Xb." In addition, in the first transfer direction Xa and the second transfer direction Xb, one side is referred to as the "first transfer direction unloading side Xa1" and the "second transfer direction unloading side Xb1," respectively, and the other side is referred to as the "first transfer direction scooping side Xa2" and the "second transfer direction scooping side Xb2," respectively. The first transfer direction unloading side Xa1 and the second transfer direction unloading side Xb1 are the sides along which the container 70 moves along the corresponding transfer direction Xa, Xb when unloading the container 70. The first transfer direction scooping side Xa2 and the second transfer direction scooping side Xb2 are sides along which the container 70 moves in the corresponding transfer direction X when scooping the container 70.

[0042] The first transfer direction Xa is a direction along the vehicle body fore-and-aft direction L when viewed in the up-down direction. In this example, the first transfer direction Xa is a direction along the horizontal direction and along the vehicle body fore-and-aft direction L. Note that the first transfer direction Xa may be a direction that intersects with the vehicle body fore-and-aft direction L when viewed in the up-down direction, or may be inclined with respect to the horizontal direction.

[0043] The second transfer direction Xb is a direction that intersects with the vehicle body's fore-and-aft direction L when viewed in the up-down direction. In this example, the second transfer direction Xb is along the horizontal direction and is perpendicular to the vehicle body's fore-and-aft direction L. Note that the second transfer direction Xb may be a direction that intersects with the vehicle body's fore-and-aft direction L at an angle other than 90° when viewed in the up-down direction, or may be inclined with respect to the horizontal direction. In this embodiment, the second transfer direction Xb corresponds to the "transfer direction."

[0044] 3, the transfer device 4 includes a transfer mast 40 that is fixed to the traveling body 1 and arranged along the vertical direction, a transfer lifting body 40B that rises and falls along the transfer mast 40, and a transfer machine H that is connected to the transfer lifting body 40B. The transfer machine H also includes a holding section A that holds a container 70 and a transfer section B that transfers the container 70. The transfer device 4 includes a transfer lifting body drive section 40M that raises and lowers the transfer lifting body 40B along the transfer mast 40. Although not shown in detail, the transfer lifting body drive section 40M includes, for example, an endless body such as a belt connected to the transfer lifting body 40B, a rotating body around which the endless body is wound, and a motor that rotates and drives the rotating body. In this embodiment, the transfer mast 40 corresponds to the "mast", and the transfer lift 40B corresponds to the "lift".

[0045] In this embodiment, the transfer device 4 can move the transfer machine H (holding section A and transfer section B) in the vertical direction, and can transfer the container 70 to each of the multiple shelf sections 80 (see FIG. 2). In this example, the control section C that controls the transfer device 4 is configured to execute lifting control that lifts and lowers the transfer lifting body 40B to transfer the container 70 to the container shelf 8. In other words, the transfer lifting body 40B lifts and lowers within a predetermined lifting range.

[0046] In this embodiment, a pair of transfer masts 40 are fixed to the running body 1 at a distance from each other in the vehicle width direction W (see also FIG. 8). The transfer lifting body 40B is supported so as to be able to move up and down relative to the pair of transfer masts 40. That is, in this embodiment, the height dimension Sh is the height from the running surface on which the running body 1 runs to the upper end of the transfer mast 40 (see FIG. 3). The height to the upper end of the transfer mast 40 is set according to the height of the shelf section 80.

[0047] As shown in FIGS. 3, 6 and 7, in this embodiment, the transfer device 4 includes a first transfer machine H1 and a second transfer machine H2.

[0048] The first transfer machine H1 includes a first holding unit 41A that holds a container 70, a first locking unit 41Bb that locks onto the container 70, a first transfer driver 41Mc that moves the first locking unit 41Bb in each transfer direction Xa, Xb, and a first holding driver 41MA that moves the first holding unit 41A along each transfer direction Xa, Xb. In this embodiment, the first locking unit 41Bb is supported by a first support member 41Bc together with a first pressing unit 41Ba that presses the container 70 toward the unloading sides Xa1, Xb1 in each transfer direction. The first support member 41Bc is supported by the first holding unit 41A and is moved relative to the first holding unit 41A in each transfer direction Xa, Xb by the first transfer driver 41Mc. That is, in this embodiment, the first locking portion 41Bb moves integrally with the first pressing portion 41Ba in each of the transfer directions Xa and Xb in accordance with the movement of the first support member 41Bc. Note that in this embodiment, the first locking portion 41Bb and the first pressing portion 41Ba constitute the first transfer portion 41B that transfers the container 70 between the first holding portion 41A and the transfer target location T.

[0049] The second transfer machine H2 includes a second holding unit 42A positioned below the first holding unit 41A and configured to hold a container 70, a second locking unit 42Bb configured to lock onto the container 70, a second transfer driver 42Mc configured to move the second locking unit 42Bb in each of the transfer directions Xa and Xb, and a second holding driver 42MA configured to move the second holding unit 42A along each of the transfer directions Xa and Xb. In this embodiment, the second locking unit 42Bb is supported by a second support member 42Bc together with a second pressing unit 42Ba configured to press the container 70 toward the unloading sides Xa1 and Xb1 in each of the transfer directions. The second support member 42Bc is supported by the second holding unit 42A and is moved relative to the second holding unit 42A along each of the transfer directions Xa and Xb by the second transfer driver 42Mc. That is, in the present embodiment, the second locking portion 42Bb moves integrally with the second pressing portion 42Ba in each of the transfer directions Xa and Xb in accordance with the movement of the second support member 42Bc. Note that in the present embodiment, the second locking portion 42Bb and the second pressing portion 42Ba constitute the second transfer portion 42B that transfers the container 70 between the second holding portion 42A and the transfer target location T.

[0050] In this embodiment, the first holding portion 41A and the second holding portion 42A are connected in the vertical direction by a holding connection portion 43. Therefore, the first holding portion 41A and the second holding portion 42A move integrally. In this example, the first holding drive portion 41MA that drives the first holding portion 41A and the second holding drive portion 42MA that drives the second holding portion 42A are configured to be driven by a common drive source.

[0051] In this example, the control unit C that controls the transfer device 4 is configured to control the transfer drive units 41Mc, 42Mc and execute movement control to move the transfer units 41B, 42B in the transfer directions Xa, Xb. The control unit C is also configured to control the holding drive units 41MA, 42MA and execute outward / outward movement control to move the holding units 41A, 42A in the transfer directions Xa, Xb. In this embodiment, the first transfer drive unit 41Mc and the second transfer drive unit 42Mc each correspond to a "movement mechanism," and the first holding drive unit 41MA and the second holding drive unit 42MA each correspond to an "outward / outward movement mechanism."

[0052] The first transfer machine H1 and the second transfer machine H2 are configured to be able to transfer a container 70 to the shelf unit 80 and the stacking area 2A, respectively. When the shelf unit 80 is set as the transfer target location T, each transfer machine H1, H2 moves the container 70 between each holder 41A, 42A and the shelf unit 80 in the second position P2, thereby transferring the container 70 to the shelf unit 80 (see the lower diagram in FIG. 5). When the stacking area 2A is set as the transfer target location T, each transfer machine H1, H2 moves the container 70 between each holder 41A, 42A and the stacking area 2A in the first position P1, thereby transferring the container 70 to the stacking area 2A (see the upper diagram in FIG. 5).

[0053] 6 and 7 are explanatory diagrams of the case where the transfer device 4 performs a transfer operation (unloading operation or scooping operation) of the container 70 to the shelf section 80 as the transfer target location T.

[0054] 6 shows the scooping (transferring) operation of the first transfer machine H1 to scoop up (transfer) the container 70 from the shelf 80, illustrating the case where the first transfer unit 41B scoops up the container 70 stored on the shelf 80 to the first holder 41A. In this case, the control unit C (see FIG. 3) aligns the position of the first transfer machine H1 with the reference position 80P (see FIG. 2) of the shelf 80, and then uses the first locking unit 41Bb to pull the container 70 toward the scooping side X2 in the transfer direction. In this embodiment, the reference position 80P of the shelf 80 is detected by a reference position detection sensor Se1 provided in the transfer device 4.

[0055] 7 shows the unloading (transferring) operation of the second transfer machine H2 to unload the container 70 onto the shelf section 80, illustrating the case where the second transfer section 42B unloads the container 70 held by the second holder 42A onto the shelf section 80. In this case, when the control section C (see FIG. 3) determines that no other container 70 is stored on the shelf section 80 onto which the container 70 is to be unloaded, the control section C (see FIG. 3) presses the container 70 toward the unloading side X1 in the transfer direction by the second pressing section 42Ba. In this embodiment, the container 70 stored on the shelf section 80 is detected by the storage container detection sensor Se2 provided in the transfer device 4.

[0056] As described above, in this embodiment, the lifting device 3 can form spaces between the multiple containers 70 stacked in the stacking area 2A in the vertical direction. The transfer device 4 then uses these spaces to transfer the containers 70 to the stacking area 2A. In this embodiment, the transfer device 4 is configured to perform scooping and unloading operations on the containers 70 in the stacking area 2A. Although not shown, in this example, the transfer device 4 is configured to perform parallel operations in which the containers 70 are scooped and unloaded in parallel in the stacking area 2A.

[0057] Here, the transport vehicle 100 according to the present disclosure performs acceleration limiting control as necessary when the transfer device 4 transfers the container 70, so as to easily minimize shaking and tilting caused by the transfer operation of the article. This will be described in detail below.

[0058] The control unit C (see FIG. 3) is configured to execute acceleration limiting control to limit the upper limit of the acceleration of the movement of the container 70 along the second transfer direction Xb by the first transfer machine H1 and the second transfer machine H2 to a lower value when the transfer lifting body 40B is located above a predetermined reference height h in the lifting range of the transfer lifting body 40B compared to when the transfer lifting body 40B is located below the reference height h. In this embodiment, the entire lifting range is divided into two regions, an upper region and a lower region, with the reference height h as the boundary. In this example, the reference height h is included in the lower region, i.e., the lower region is a region below the reference height h, but this is not limited to this.

[0059] The reference height h can be set to a height corresponding to the height of the center of gravity of the transport vehicle 100. In this embodiment, the reference height h is set to the height of the center of gravity G of the transport vehicle 100. Note that the center of gravity of the transport vehicle 100 is determined taking into consideration the mass of each part that constitutes the transport vehicle 100.

[0060] In this embodiment, as shown in FIG. 8 , when the container 70 is transferred between the transfer device 4 and the shelf unit 80 (in other words, when the orientation of the transfer device 4 is the second posture P2 and the transfer device 4 moves the container 70 along the second transfer direction Xb), if the transfer lift 40B is located in a region above the reference height h, the control unit C executes acceleration limiting control to limit the upper limit of acceleration. FIG. 9 is a graph showing the correspondence relationship between the height of the lift (the height of the transfer lift 40B) and the upper limit of acceleration. As shown in FIG. 9 , by executing acceleration limiting control, the upper limit of acceleration is limited to a value (“α5” in FIG. 9 ) that is lower than any of the values ​​(“α1” to “α4” in FIG. 9 ) when acceleration limiting control is not executed. That is, in this example, the upper limit of acceleration of the movement of the container 70 along the second transfer direction Xb by the first transfer unit H1 and the second transfer unit H2 is limited to “α5.”

[0061] In this embodiment, the upper limit of the movement speed of the container 70 in the second transfer direction Xb by the first transfer machine H1 and the second transfer machine H2 is set to be the same regardless of whether acceleration limit control is performed. In other words, the upper limit of the movement speed of the container 70 in the second transfer direction Xb by the first transfer machine H1 and the second transfer machine H2 is set to be the same regardless of whether the transfer lift 40B is in the region above or below the reference height h. In other words, the control unit C sets the upper limit of the movement speed of the container 70 in the second transfer direction Xb by the first transfer machine H1 and the second transfer machine H2 above and below the reference height h.

[0062] Here, if the transport vehicle 100 sways due to the extension and retraction of the holding parts 41A, 42A in the second transfer direction Xb, the positional relationship with the shelf part 80 changes, making it difficult to properly transfer the containers 70. On the other hand, the movement of the transfer parts 41B, 42B in the second transfer direction Xb, in other words, the movement of the locking parts 41Bb, 42Bb in the second transfer direction Xb, has little effect on the transfer operation because the positional relationship between the transfer parts 41B, 42B and the shelf part 80 is already determined at the time of movement.

[0063] Therefore, in this example, when the transfer lift body 40B is located in a region above the reference height h and the control unit C executes the outgoing / outgoing control to move the first holding unit 41A and the second holding unit 42A in the second transfer direction Xb, the control unit C executes the acceleration limiting control. On the other hand, even when the transfer lift body 40B is located in a region above the reference height h, the control unit C does not execute the acceleration limiting control to execute the movement control to move the first transfer unit 41B and the second transfer unit 42B in the transfer directions Xa and Xb. In other words, when the outgoing / outgoing control is executed, if the transfer lift body 40B is located in a region above the reference height h, the upper limit of the acceleration is limited by the acceleration limiting control. However, when the movement control is executed, the upper limit of the acceleration is not limited regardless of whether the transfer lift body 40B is located in a region above or below the reference height h. In other words, the control unit C performs acceleration limiting control on the movement of the container 70 associated with the advance / retraction of the first holding unit 41A and the second holding unit 42A by the first holding drive unit 41MA and the second holding drive unit 42MA, but does not perform acceleration limiting control on the movement of the container 70 associated with the movement of the first locking unit 41Bb and the second locking unit 42Bb by the first transfer drive unit 41Mc and the second transfer drive unit 42Mc.

[0064] 8, when the transfer lift 40B is located in a region below the reference height h, the control unit C does not perform acceleration limit control. In this case, the maximum design value may be the upper limit of the acceleration, but the upper limit of the acceleration may be limited to a value higher than the upper limit in the acceleration limit control.

[0065] In this example, when the transfer lifting body 40B is located in a region below the reference height h, the upper limit of the acceleration is restricted to decrease as the height of the transfer lifting body 40B increases. Specifically, as shown in Fig. 9, the upper limit of the acceleration is restricted to decrease in stages from "α1" to "α4" as the height of the transfer lifting body 40B increases. In other words, in the region below the reference height h in the lifting range, the control unit C restricts the upper limit of the acceleration of the movement of the container 70 in the second transfer direction Xb by the first transfer machine H1 and the second transfer machine H2 so that the upper limit of the acceleration gradually decreases from the lower limit of the region toward the upper limit.

[0066] In this embodiment, when a container 70 is transferred between the transfer device 4 and the stacking area 2A (in other words, when the orientation of the transfer device 4 is the first attitude P1 and the transfer device 4 moves the container 70 along the first transfer direction Xa), acceleration limit control is not performed regardless of whether the transfer lift body 40B is located in an area above the reference height h. In this case, the maximum design value can essentially become the upper limit of the acceleration.

[0067] The above-described configuration can minimize shaking and tilting of the transport vehicle 100 caused by the transfer operation of the container 70. In addition, it can prevent a decrease in the accuracy of the transfer operation, reduce the need to wait for the transfer operation, and improve the efficiency of the transfer operation.

[0068] Other Embodiments Next, other embodiments of the transport vehicle will be described.

[0069] (1) In the above embodiment, one reference height h is set, and the entire lifting range is divided into two regions, an upper region and a lower region, with the reference height h as the boundary. However, the present invention is not limited to this. Multiple reference heights h may be set, and the entire lifting range or a portion thereof may be divided into three or more regions by the multiple reference heights h. In this case, it is preferable that the upper limit of acceleration be set to decrease from the lower region to the upper region. For example, as shown in Fig. 10, a first reference height h1 may be set at the height of the center of gravity G of the transport vehicle 100, and a second reference height h2 and a third reference height h3 may be set above the first reference height h1, thereby dividing the entire lifting range into four regions. In this case, as shown in Fig. 11, the upper limit of acceleration in the acceleration limit control is preferably set to gradually decrease in the order of "β2" (first upper limit) in the region between the first reference height h1 and the second reference height h2, "β3" (second upper limit) in the region between the second reference height h2 and the third reference height h3, and "β4" (third upper limit) in the region above the third reference height h3. Note that "β1", the upper limit of acceleration in the region below the first reference height h1, may be set to a maximum value in design.

[0070] (2) In the above embodiment, when the transfer lift 40B is located in an area above the reference height h, the acceleration limiting control is executed when the entry / exit control is executed, but the acceleration limiting control is not executed when the movement control is executed. However, the present invention is not limited to this. When the transfer lift 40B is located in an area above the reference height h, the acceleration limiting control may also be executed when the movement control is executed.

[0071] (3) In the above embodiment, the acceleration limit control is performed only on the movement of the container 70 along the second transfer direction Xb when the container 70 is transferred between the transfer device 4 and the shelf 80. However, the present invention is not limited to this. For example, the acceleration limit control may be performed on the movement of the container 70 along the first transfer direction Xa when the container 70 is transferred between the transfer device 4 and the stacking area 2A. Furthermore, when the container 70 is held by the holder A with its center of gravity not located on an extension of the rotation axis 51 of the rotation device 5, the acceleration limit control may be performed on the rotation operation.

[0072] (4) In the above embodiment, the upper limit of the acceleration of the movement of the container 70 in the second transfer direction Xb by each of the transfer machines H1 and H2 is limited so that the upper limit of the acceleration gradually decreases from the lower limit of the lifting range to the upper limit of the lifting range. However, the present invention is not limited to this. For example, as shown in FIG. 12 , the upper limit of the acceleration may be limited to a constant value of “γ1” in the region below the reference height h in the lifting range, and the upper limit of the acceleration may be limited to “γ2” in the region above the reference height h by the acceleration limit control. Furthermore, the upper limit of the acceleration of the movement of the container 70 may be limited so that the upper limit of the acceleration gradually decreases from the lower limit of the region to the upper limit of the lifting range in all or part of the lifting range.

[0073] (5) The configurations disclosed in the above-described embodiments can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope of the present disclosure.

[0074] [Summary of the above embodiment] The above-described transport vehicle will now be described.

[0075] A transport vehicle that travels along the front of a storage shelf that has a plurality of shelves in a vertical direction for storing items and transports the items, a traveling body that travels along a travel path; a transfer device that transfers the article; a control unit that controls the transfer device, The transfer device is a mast fixed to the traveling body and arranged along the vertical direction; a lifting body that moves up and down along the mast; a transfer machine supported on the lifting body; Equipped with The direction in which the running body travels is the front-rear direction of the vehicle body, the transfer machine includes a holding unit that holds the article, and is configured to move the article along a transfer direction that intersects with the vehicle body's fore-and-aft direction when viewed in a vertical direction, thereby transferring the article between the holding unit and the shelf unit, When the lifting body is located above a predetermined reference height within the lifting range of the lifting body, the control unit performs acceleration limiting control to lower the upper limit of the acceleration of the movement of the item along the transfer direction by the transfer machine compared to when the lifting body is located below the reference height.

[0076] If the swaying or tilting of the transport vehicle increases due to the transfer operation, the relative positions of the items, shelves, and transfer machine will change, causing a decrease in the accuracy of the transfer operation.To prevent this decrease in accuracy, it was necessary to wait for the swaying or tilting of the transport vehicle to subside before proceeding with the transfer operation. However, with this configuration, it is easy to minimize the shaking and tilting of the transport vehicle caused by the item transfer operation, which prevents a decrease in the accuracy of the transfer operation and reduces the need to wait for the transfer operation, thereby improving the efficiency of the transfer operation. In this way, with this configuration, it is possible to realize a transport vehicle that can easily minimize shaking and tilting of the transport vehicle caused by the operation of transferring articles.

[0077] Here, it is preferable that the control unit sets the upper limit of the moving speed of the article in the transfer direction by the transfer machine to be the same above and below the reference height.

[0078] The acceleration of the goods affects the swaying and tilting of the transport vehicle during the goods transfer operation. With this configuration, the swaying and tilting of the transport vehicle can be reduced by limiting the acceleration. Furthermore, because the upper limit of the goods movement speed is the same in the area above and below the reference height, the efficiency of the transfer operation can be improved compared to when the upper limit of the goods movement speed in the upper area is limited lower than in the lower area.

[0079] The transfer machine further includes a locking portion that is locked to the article, a moving mechanism that moves the locking portion in the transfer direction, and an extending / retracting mechanism that moves the holding portion in the transfer direction, It is preferable that the control unit performs the acceleration limiting control for the movement of the item associated with the extension and retraction of the holding part by the extension and retraction mechanism, and does not perform the acceleration limiting control for the movement of the item associated with the movement of the engaging part by the movement mechanism.

[0080] According to this configuration, the acceleration limiting control is performed only for the exit / entrance operation, which has a large effect on the swaying and tilting of the transport vehicle, and the acceleration limiting control is not performed for the movement of the locking part by the moving mechanism, which has a relatively small effect on the swaying and tilting of the transport vehicle, so the efficiency of the transfer operation can be improved compared to when the acceleration limiting control is performed for both of these. Therefore, the efficiency of the transfer operation can be improved while effectively suppressing the swaying and tilting of the transport vehicle.

[0081] Preferably, the reference height is set to a height corresponding to the height of the center of gravity of the transport vehicle.

[0082] As a result of verification by the inventors, it was found that movement of the transport vehicle in the direction of transferring an item above the center of gravity has a greater effect on the swaying and tilting of the transport vehicle than movement of the transport vehicle in the direction of transferring an item below the center of gravity. According to this configuration, the upper limit of the acceleration of movement of the transport vehicle in the direction of transferring an item above the center of gravity is limited to be lower than the upper limit of the acceleration of movement of the transport vehicle in the direction of transferring an item below the center of gravity, so that it is possible to minimize the swaying and tilting of the transport vehicle caused by the operation of transferring an item while minimizing the decrease in efficiency of the operation of transferring an item.

[0083] Further, a direction perpendicular to the vehicle body longitudinal direction when viewed in the up-down direction is defined as a vehicle body width direction, The dimension of the traveling body in the vehicle body width direction is 1 / 2 or less of the dimension of the traveling body in the vehicle body front-rear direction, It is preferable that the vertical dimension from the lower end of the traveling body to the upper end of the mast is at least twice the dimension of the traveling body in the vehicle body width direction.

[0084] According to this configuration, since the running body is long in the fore-and-aft direction of the vehicle body and has a tall shape, the movement of goods along the transfer direction that intersects with the fore-and-aft direction of the vehicle body is likely to cause the vehicle to sway significantly. Therefore, by executing the acceleration limiting control, the swaying and tilt of the transport vehicle can be effectively reduced.

[0085] It is also preferable that the control unit limits the upper limit of the acceleration of the movement of the item along the transfer direction in at least a portion of the lifting range so that the upper limit of the acceleration gradually decreases from the lower limit of the region toward the upper limit.

[0086] According to this configuration, in at least some areas of the lifting range, the upper limit of acceleration is restricted to gradually decrease as one moves upward, thereby minimizing the decrease in efficiency of the transfer operation while making it easier to minimize the shaking and tilting of the transport vehicle caused by the transfer operation of goods. [Industrial Applicability]

[0087] The technology disclosed herein can be used in a transport vehicle that travels along the front of a storage shelf that has multiple shelves arranged vertically for storing items, and transports items. [Explanation of symbols]

[0088] 100: Transport vehicle 1: Running body 4:Transfer device 8: Container shelf (storage shelf) 40: Transfer mast (mast) 40B: Transfer lift (lift) 41A: 1st holding part (holding part) 41Bb: First locking part (locking part) 41MA: First holding drive unit (extension / retraction mechanism) 41Mc: First transfer drive unit (movement mechanism) 42A:Second holding part (holding part) 42Bb: Second locking part (locking part) 42Mc: Second transfer drive unit (movement mechanism) 42MA: Second holding drive unit (extension / retraction mechanism) 70: Container (article) 80:Shelf A: Holding part C: Control section G: Center of gravity H:Transfer machine H1: 1st transfer machine (transfer machine) H2: 2nd transfer machine (transfer machine) R: Travel route L: Front-rear direction of the vehicle W: Vehicle width direction Xb: 2nd transfer direction (transfer direction) Sl: Length dimension Sw: Width dimension Sh: Height dimension h: Reference height

Claims

1. A transport vehicle that travels along the front of a storage shelf that has a plurality of shelves in a vertical direction for storing items and transports the items, a traveling body that travels along a travel path; A transfer device that transfers the article; a control unit that controls the transfer device, The transfer device is a mast fixed to the traveling body and arranged along the vertical direction; a lifting body that moves up and down along the mast; a transfer machine supported on the lifting body; Equipped with The direction in which the running body travels is the front-rear direction of the vehicle body, the transfer machine includes a holding unit that holds the article, and is configured to move the article along a transfer direction that intersects with the vehicle body's fore-and-aft direction when viewed in a vertical direction, thereby transferring the article between the holding unit and the shelf unit, The control unit When the lifting body is located above a predetermined reference height in the lifting range of the lifting body, an acceleration limiting control is executed to limit the upper limit of the acceleration of the movement of the article along the transfer direction by the transfer machine to a lower value than when the lifting body is located below the reference height, A transport vehicle in which the upper limit of the moving speed of the article along the transfer direction by the transfer machine is the same above and below the reference height.

2. A transport vehicle that travels along the front of a storage shelf that has a plurality of shelves in a vertical direction for storing items and transports the items, a traveling body that travels along a travel path; A transfer device that transfers the article; a control unit that controls the transfer device, The transfer device is a mast fixed to the traveling body and arranged along the vertical direction; a lifting body that moves up and down along the mast; a transfer machine supported on the lifting body; Equipped with The direction in which the running body travels is the front-rear direction of the vehicle body, The transfer machine includes a holding section that holds the item, a locking section that is locked to the item, a movement mechanism that moves the locking section in the transfer direction, and an extension / withdrawal mechanism that moves the holding section in the transfer direction, and is configured to move the item along a transfer direction that intersects with the fore-and-aft direction of the vehicle body when viewed in the up-down direction, and transfer the item between the holding section and the shelf section, The control unit When the lifting body is located above a predetermined reference height in the lifting range of the lifting body, an acceleration limiting control is executed to limit the upper limit of the acceleration of the movement of the article along the transfer direction by the transfer machine to a lower value than when the lifting body is located below the reference height, A transport vehicle that performs the acceleration limiting control for the movement of the item associated with the extension and retraction of the holding part by the extension and retraction mechanism, and does not perform the acceleration limiting control for the movement of the item associated with the movement of the engaging part by the movement mechanism.

3. A transport vehicle that travels along the front of a storage shelf that has a plurality of shelves in a vertical direction for storing items and transports the items, a traveling body that travels along a travel path; A transfer device that transfers the article; a control unit that controls the transfer device, The transfer device is a mast fixed to the traveling body and arranged along the vertical direction; a lifting body that moves up and down along the mast; a transfer machine supported on the lifting body; Equipped with The direction in which the running body travels is the front-rear direction of the vehicle body, the transfer machine includes a holding unit that holds the article, and is configured to move the article along a transfer direction that intersects with the vehicle body's fore-and-aft direction when viewed in a vertical direction, thereby transferring the article between the holding unit and the shelf unit, When the lifting body is located above a predetermined reference height in the lifting range of the lifting body, the control unit executes acceleration limiting control to lower the upper limit of acceleration of the movement of the article along the transfer direction by the transfer machine compared to when the lifting body is located below the reference height, The reference height is set to a height corresponding to the height of the center of gravity of the transport vehicle.

4. A direction perpendicular to the vehicle body longitudinal direction when viewed in the up-down direction is defined as a vehicle body width direction, The dimension of the running body in the vehicle body width direction is equal to or less than half of the dimension of the running body in the vehicle body front-rear direction, The transport vehicle according to claim 1 , wherein the vertical dimension from the lower end of the traveling body to the upper end of the mast is at least twice the dimension of the traveling body in the vehicle body width direction.

5. The transport vehicle described in any one of claims 1 to 3, wherein the control unit limits the upper limit of the acceleration of the movement of the item along the transfer direction in at least a portion of the lifting range so that the upper limit of the acceleration gradually decreases from the lower limit of the region toward the upper limit.

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