Transport vehicle

Abstract

The transfer machine (H1, H2) is provided with a holding unit for holding an article, and is configured so as to move the article in a transfer direction intersecting the front-rear direction of the vehicle body when viewed in the vertical direction, and to transfer the article between the holding unit and the rack unit (80). When the lifting body (40B) is located above a predetermined reference height (h) in the lifting range of the lifting body (40B), the control unit executes acceleration limiting control for limiting the upper limit of acceleration of the movement of the article in the transfer direction by the transfer machines (H1, H2) to be lower than when the lifting body (40B) is located below the reference height (h).

Description

Technical Field

[0001] The present invention relates to a transport vehicle that travels along the front of a storage rack having a plurality of layers of shelf portions for storing articles in the vertical direction to transport the articles. Background Art

[0002] Conventionally, this type of transport vehicle includes a transfer device for transferring articles to a storage rack.

[0003] For example, the transfer device (2) disclosed in Japanese Patent Gazette No. 6337706 (Patent Document 1) comprises: a cargo loading section (26) on which cargo (10) is loaded; and a sliding arm (28) having a top portion (42) that reciprocates along the transfer direction of the cargo (10). The transfer device (2) is configured to perform an unloading action of transferring the cargo (10) from the cargo loading section (26) to a support (12a, 12b) and a lifting action of transferring the cargo (10) from the support (12a, 12b) to the cargo loading section (26) by utilizing the reciprocating movement of the top portion (42) of the sliding arm (28). In addition, the reference numerals shown in parentheses in the above are the reference numerals of Patent Document 1. Prior Art Literature Patent Literature

[0004] Patent document 1: Japanese Patent No. 6337706. Summary of the invention Problems to be solved by the invention

[0005] However, in a transport vehicle equipped with a transfer device as described above, an inertial force is generated in the direction along the transfer direction as the object is transferred, and there is a possibility that the transport vehicle will shake or tilt. Furthermore, if the transport vehicle shakes or tilts more, the positional relationship between the object, the shelf, and the transfer device changes, and there is a possibility that the transfer operation is hindered.

[0006] The present invention has been made in view of the above-mentioned actual situation, and an object of the present invention is to realize a transport vehicle that can easily suppress the shaking or tilting of the transport vehicle caused by the transfer operation of articles. Solutions to Solve Problems

[0007] A transport vehicle is a transport vehicle that runs along the front of a storage rack having a shelf portion with multiple layers of storage items in the vertical direction to transport the aforementioned items, and comprises: A traveling body, which travels along a traveling path; A transfer device for transferring the aforementioned articles; and a control unit, which controls the aforementioned transfer device, The aforementioned transfer device comprises: A mast fixed to the traveling body and arranged in an up-down direction; a lifting body that is lifted and lowered along the mast; and A transfer machine, which is supported by the aforementioned lifting body, The direction of travel of the aforementioned traveling body is the front-rear direction of the vehicle body. The transfer machine includes a holding portion for holding the article, and is configured to move the article in a transfer direction intersecting the front-rear direction of the vehicle body when viewed in the vertical direction, and to transfer the article between the holding portion and the rack portion. When the lift body is located above a predetermined reference height within the lift range of the lift body, the control unit performs acceleration limiting control that limits the upper limit of the acceleration of the movement of the article along the transfer direction based on the transfer machine to a lower level than when the lift body is located below the reference height.

[0008] If the transfer action causes the transport vehicle to shake or tilt more, the positional relationship between the article, the shelf and the transfer machine changes, and the transfer action accuracy decreases. In order to suppress such a decrease in accuracy, the transfer action needs to be put on standby until the transport vehicle shakes or tilts. However, according to this configuration, the shaking or tilting of the transport vehicle caused by the transfer operation of the article can be easily suppressed. Therefore, the decrease in the accuracy of such transfer operation can be suppressed, and the necessity of waiting for the transfer operation can be reduced, which can improve the efficiency of the transfer operation. As described above, according to this configuration, it is possible to realize a transport vehicle that can easily suppress the shaking or tilting of the transport vehicle caused by the article transfer operation.

[0009] Further features and advantages of the technology according to the present disclosure will become more apparent from the following description of illustrative and non-limiting embodiments described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a top view of the conveying equipment including the conveying vehicle. Figure 2 It is the front view of the container rack. Figure 3 This is a view of the conveyor vehicle in the width direction. Figure 4 This is an explanatory diagram showing the structure of the traveling body. Figure 5 It is a plan view showing a first posture and a second posture of the transfer device. Figure 6 It is an explanatory diagram showing the lifting action of the container with respect to the stand. Figure 7It is an explanatory diagram showing the removal operation of the container from the shelf. Figure 8 It is an explanatory diagram showing the reference height. Fig. 9 It is a graph for explaining the acceleration limiting process. Fig.10 It is an explanatory diagram showing the reference height according to another embodiment. Fig.11 This is a graph for explaining acceleration limiting processing according to another embodiment. Fig.12 This is a graph for explaining acceleration limiting processing according to another embodiment. DETAILED DESCRIPTION

[0011] The transport vehicle transports articles by traveling along the front of a storage rack having a shelf portion with multiple layers of storage articles in the vertical direction. Hereinafter, an embodiment of the transport vehicle will be described by taking as an example a case where a transport device for transporting containers is provided with a transport vehicle. That is, in this embodiment, the container is equivalent to an "article", and the container rack for storing the container is equivalent to a "storage rack".

[0012] like Figure 1 As shown, the conveying device F includes a storage container 70 (see Figure 3 ) and a carrying-in and carrying-out section 9 for carrying in and out the container 70. The transport vehicle 100 transports the container 70 carried in by the carrying-in and carrying-out section 9 to the container rack 8, or transports the container 70 stored in the container rack 8 to the carrying-in and carrying-out section 9 for carrying out.

[0013] In the present embodiment, a plurality of container racks 8 are arranged at predetermined intervals and in parallel with each other. Each of the plurality of container racks 8 is open at least on the front side, and the container 70 is stored and retrieved on the front side. Moreover, a portion of the travel path R of the traveling body 1 (transport vehicle 100) is set between a pair of container racks 8 adjacent to each other with their front sides facing each other. In addition, the container rack 8 arranged at the end among the plurality of container racks 8 provided in the transport equipment F is arranged with its front side facing outward, and a portion of the travel path R is also set in the area along the front side of the container rack 8 at the end. In addition, the transport equipment F is provided with a plurality of carrying in and out sections 9, and a portion of the travel path R is also set in the area passing through each of the plurality of carrying in and out sections 9.

[0014] The travel path R includes an in-rack path Ra extending along the front of the container rack 8 in the extension direction of the container rack 8 and an out-rack path Rb set outside the configuration area of ​​the container rack 8. The in-rack path Ra is set corresponding to each of the multiple container racks 8. In the present embodiment, a portion of the travel path R set in the area between a pair of container racks 8 adjacent to each other with their fronts facing each other, and a portion of the travel path R set along the area of ​​the front of the container rack 8 configured with its front facing outward are equivalent to the in-rack path Ra. In addition, the out-rack path Rb is set in a manner that connects multiple in-rack paths Ra. In addition, the out-rack path Rb is also set in a manner that passes through each of the multiple carrying in and out sections 9. In the present embodiment, the portion of the travel path R other than the in-rack path Ra is equivalent to the out-rack path Rb.

[0015] 〔Container rack〕 like Figure 2 As shown, the container rack 8 has a rack portion 80 for storing multiple layers of containers 70 in the vertical direction. In this embodiment, the container rack 8 has a plurality of beam members 82 extending in the horizontal direction along the front surface of the container rack 8, and a plurality of support members 81 extending in the vertical direction and connected to each of the plurality of beam members 82.

[0016] Each of the plurality of beam members 82 is connected to a loading member 83 for loading the container 70. In this example, the container 70 is stored in the shelf 80 by being loaded on a pair of loading members 83. In addition, in the shelf 80, a plurality of sets of a pair of loading members 83 are arranged, and a plurality of containers 70 can be stored in one shelf 80. In addition, in this example, Figure 3 In the front view shown, a region between a pair of support members 81 adjacent in the width direction (left-right direction) and between a pair of beam members 82 adjacent in the up-down direction corresponds to the opening of the container rack 8 .

[0017] In the present embodiment, a target portion 82T is provided at a reference position 80P of the shelf portion 80 for storing the container 70. In the present example, the target portion 82T is provided on the beam member 82. One target portion 82T is provided for each set of a pair of placement members 83. In the example shown in the figure, the target portion 82T is formed by a hole formed in the beam member 82.

[0018] 〔container〕 The container 70 is a transport object based on the transport vehicle 100. Although the detailed illustration is omitted, the container 70 is formed in a box shape with an opening portion opened upward. In this example, the outer shape of the container 70 when viewed from the top and bottom is rectangular. The container 70 can accommodate a predetermined object. The object includes, for example, various commodities such as food or daily necessities, or parts or semi-finished products used in a production line of a factory.

[0019] In this embodiment, the container 70 is configured so that it can be stacked with another container 70 while the contents are contained therein. That is, the container 70 is configured so that it can be stacked in the vertical direction (see Figure 3 ). In this example, the bottom of the container 70 is fitted into the opening of the other container 70 from above, so that the two containers 70 are stacked in the vertical direction.

[0020] 〔Transport vehicle〕 like Figure 3 As shown, the transport vehicle 100 includes: a travel body 1 that travels along a predetermined travel path R; a transfer device 4 that transfers a container 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 container group 7 in a stacked state in a predetermined stacking area 2A; and a lifting device 3 that lifts the container 70 of the container group 7 supported by the container group support unit 2. In addition, the control unit C controls the travel body 1, the container group support unit 2, and the lifting device 3 in addition to the transfer device 4.

[0021] The container group support 2, the lifting device 3, and the transfer device 4 are mounted on the traveling body 1. If the traveling direction of the traveling body 1 is defined as the "vehicle front-rear direction L", the container group support 2 and the transfer device 4 are arranged side by side on the traveling body 1 along the vehicle front-rear direction L. In addition, in the following, the direction orthogonal to the vehicle front-rear direction L when viewed in the up-down direction is defined as the "vehicle width direction W". Here, the vehicle front-rear direction L and the vehicle width direction W are horizontal directions orthogonal to each other.

[0022] In addition, if Figure 3 and Figure 4 As shown, the transport vehicle 100, when the dimension of the vehicle body in the front-rear direction L of the traveling body 1 is the length dimension S1, the dimension of the vehicle body in the width direction W of the traveling body 1 is the width dimension Sw, and the height from the lower end of the traveling body 1 to the upper end of a pair of transfer masts 40 described later is the height dimension Sh, the width dimension Sw is less than 1 / 2 of the length dimension S1, and the height dimension Sh is more than 2 times the width dimension Sw. In addition, in the present embodiment, the height dimension Sh corresponds to "the dimension in the vertical direction from the lower end of the traveling body to the upper end of the mast".

[0023] The control unit C controls each functional unit of the transport vehicle 100. In this example, the control unit C controls the travel body 1, the container group support unit 2, the lifting device 3, the transfer device 4, and the swing device 5 described later. The actions for transporting and transferring the container 70 are realized by the control of each functional unit by the control unit C. The control unit C has, for example, a processor such as a microcomputer, a peripheral circuit such as a memory, etc. Moreover, each function is realized by the cooperation of these hardware and a program executed on a processor such as a computer.

[0024] 〔Moving body〕 The traveling body 1 is traveling along a travel path R (refer to Figure 1 ) In the present embodiment, the traveling body 1 is configured to travel on the inner path Ra and the outer path Rb. The traveling body 1 is configured to travel along the container rack 8 when traveling on the inner path Ra, and more specifically, along the front of the container rack 8. In the present embodiment, the traveling body 1 is configured to travel on the ground.

[0025] The traveling body 1 includes: a traveling main body 10; a plurality of traveling wheels 11 connected to the traveling main body 10; and a traveling drive unit 11M that drives at least one of the plurality of traveling wheels 11. The traveling drive unit 11M includes a motor (not shown). The traveling drive unit 11M drives the traveling wheels 11 to provide a propulsion force to the traveling body 1.

[0026] like Figure 4 As shown, in this embodiment, a pair of driving wheels 11a are separately provided in the vehicle body width direction W at the center region of the vehicle body front-rear direction L of the traveling main body 10. The pair of driving wheels 11a are driven by different traveling driving units 11M, respectively. In addition, driven wheels 11b are provided on both sides of the vehicle body front-rear direction L for each of the pair of driving wheels 11a.

[0027] In the present embodiment, the length dimension S1 is the length dimension of the vehicle body front-rear direction L of the main body portion 10 (see Figure 3 ), the width dimension Sw is the dimension of the vehicle body width direction W of the driving main body 10 (refer to Figure 4 The width of the traveling body 1 (traveling main body 10) is set corresponding to the dimension of the length direction of the container 70 so that even if the container 70 is turned by the transfer device 4 as described later, the container 70 is also contained within the width of the traveling body 1 (traveling main body 10).

[0028] With the above-mentioned structure, the traveling body 1 can rotate around the axis in the vertical direction. Figure 4The traveling body 1 is driven to rotate in the direction indicated by the arrow in the figure, and the traveling body 1 rotates around the axis along the vertical direction. As a result, the traveling body 1 can change the traveling direction in a relatively narrow area.

[0029] 〔Container group support part〕 like Figure 3 As shown, the container group support portion 2 is mounted on the traveling body 1. The container group support portion 2 is configured in a manner capable of supporting a plurality of containers 70 as a container group 7 in a stacked state. Above the container group support portion 2, a stacking area 2A for arranging the container group 7 is defined. The stacking area 2A is a three-dimensional imaginary area extending upward from the container group support portion 2. In this example, the container group support portion 2 is configured as a conveyor capable of moving the container group 7 while the container group 7 is loaded thereon. In this example, the container group support portion 2 is capable of moving the container group 7 along the vehicle body width direction W. As a conveyor constituting the container group support portion 2, well-known conveyors such as a roller conveyor, a chain conveyor, and a belt conveyor may be used.

[0030] The container group 7 in which a plurality of containers 70 are stacked is carried into the carrying in and out section 9 (see Figure 1 ). In a state where the traveling body 1 is adjacent to the carrying-in and carrying-out section 9, the container group support section 2 receives the container group 7 from the carrying-in and carrying-out section 9 or transfers the container group 7 to the carrying-in and carrying-out section 9. That is, the container group support section 2 is configured in a manner to transfer the container group 7 between the carrying-in and carrying-out section 9. Although detailed illustrations are omitted, in this example, the carrying-in and carrying-out section 9 is adjacent to a picking area where the operation of taking out the contained objects such as goods from the container 70 is performed. If the container group 7 is transferred from the container group support section 2 to the carrying-in and carrying-out section 9, the contained objects are taken out from the container 70 in the picking area adjacent to the carrying-in and carrying-out section 9. After a part or all of the contained objects contained in the container 70 are taken out, the container 70 is transferred from the carrying-in and carrying-out section 9 to the container group support section 2 (transport vehicle 100) and transported to the container rack 8 again. However, the carrying-in and carrying-out section 9 may not be adjacent to the picking area, but may be adjacent to other equipment or work areas. In addition, for example, the carrying-in and carrying-out section 9 may be configured to carry the container group 7 transferred from the container group supporting section 2 to the outside of the conveying facility F.

[0031] 〔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).

[0032] The lifting device 3 includes a lifting mast 30 erected upward from the traveling body 1, a lifting elevating body 30B connected to the lifting mast 30, and a lifting elevating body driving unit 30M that elevates the lifting elevating body 30B along the lifting mast 30. Although not shown in detail, the lifting elevating body driving unit 30M includes, for example, an annular body such as a belt connected to the lifting elevating body 30B, a rotating body around which the annular body is wound, and a motor that rotationally drives the rotating body.

[0033] The lifting device 3 includes: a first lifting mechanism 31 that lifts a container 70 of any height in the container group 7 stacked in the stacking area 2A relative to a container 70 adjacent to the container 70 below the 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 a container 70 adjacent to the container 70 below the container 70. In addition, in the present embodiment, the first lifting mechanism 31 and the second lifting mechanism 32 are arranged separately in the vertical direction. Thus, although the illustration is omitted, a space can be formed in the vertical direction between the container 70 lifted by the first lifting mechanism 31 and the container 70 lifted by the second lifting mechanism 32. In addition, a space in the vertical direction can also be formed below the container 70 lifted by the second lifting mechanism 32.

[0034] Although details are omitted, in the present embodiment, when a space is formed in the vertical direction between the container 70 lifted by the first lifting mechanism 31 and the container 70 lifted by the second lifting mechanism 32, the other container 70 can be unloaded in the space. In addition, when a space in the vertical direction is formed below the container 70 lifted by the second lifting mechanism 32, the container 70 arranged below the container 70 lifted by the second lifting mechanism 32 can be lifted up by using the space.

[0035] 〔Transfer device〕 like Figure 3 As shown, the transfer device 4 is mounted on the traveling body 1. The transfer device 4 is configured to transfer the container 70 relative to the transfer target site T. The transfer device 4 is configured to perform an unloading operation of transferring the container 70 to the transfer target site T and a lifting operation of transferring the container 70 from the transfer target site T. In addition, in this specification, the case of transferring the container 70 from the transfer target site T to the transfer device 4 is referred to as "lifting", and "lifting" is not limited to a specific transfer operation. In this embodiment, the transfer target site T includes a stacking area 2A and a rack portion 80 of the container rack 8.

[0036] In this embodiment, the transport vehicle 100 includes a rotating device 5 for rotating the transfer device 4 around an axis in the vertical direction. Figure 5As shown, the swivel device 5 is configured as follows: the transfer device 4 (more specifically, a part of the transfer device 4) is swiveled around an axis in the up-down direction to change the orientation of the transfer device 4 to a first posture P1 when the transfer target portion T is the stacking region 2A and a second posture P2 when the transfer target portion T is the container rack 8 (rack portion 80). In this example, the swivel device 5 includes: a swivel table 50 that supports the transfer device 4 (more specifically, a part of the transfer device 4); a swivel shaft 51 that supports the swivel table 50 to be swivelable relative to the transfer lifting body 40B; and a swivel drive unit 5M that drives the swivel shaft 51. In this way, in this embodiment, the moving direction of the container 70 transferred by the transfer device 4 can be changed in a horizontal plane by the swivel device 5.

[0037] The moving direction of the container 70 transferred by the transfer device 4 when the orientation of the transfer device 4 is the first posture P1 is referred to as the "first transfer direction Xa", and the moving direction of the container 70 transferred by the transfer device 4 when the orientation of the transfer device 4 is the second posture P2 is referred to as the "second transfer direction Xb". In addition, one side in the first transfer direction Xa and the second transfer direction Xb are respectively referred to as the "first transfer direction unloading side Xa1" and the "second transfer direction unloading side Xb1", and the other side are respectively referred to as the "first transfer direction lifting side Xa2" and the "second transfer direction lifting side Xb2". The first transfer direction unloading side Xa1 and the second transfer direction unloading side Xb1 are the sides where the container 70 moves along the corresponding transfer directions Xa and Xb when the container 70 is unloaded. The first transfer direction lifting side Xa2 and the second transfer direction lifting side Xb2 are sides where the container 70 is moved along the corresponding transfer directions Xa and Xb when the container 70 is lifted.

[0038] The first transfer direction Xa is a direction along the vehicle body front-rear direction L when viewed in the vertical direction. In this example, the first transfer direction Xa is a direction along the horizontal direction and along the vehicle body front-rear direction L. In addition, the first transfer direction Xa may be a direction intersecting the vehicle body front-rear direction L when viewed in the vertical direction, or may be inclined relative to the horizontal direction.

[0039] The second transfer direction Xb is a direction that intersects the front-rear direction L of the vehicle body when viewed in the vertical direction. In this example, the second transfer direction Xb is a direction that is along the horizontal direction and is orthogonal to the front-rear direction L of the vehicle body. In addition, the second transfer direction Xb may be a direction that intersects the front-rear direction L of the vehicle body at an angle other than 90° when viewed in the vertical direction, or may be inclined relative to the horizontal direction. In this embodiment, the second transfer direction Xb is equivalent to the "transfer direction".

[0040] like Figure 3As shown, the transfer device 4 includes: a transfer mast 40, which is fixed to the traveling body 1 and arranged in a manner along the up-down direction; a transfer lifting body 40B, which is lifted and lowered along the transfer mast 40; and a transfer machine H, which is connected to the transfer lifting body 40B. In addition, the transfer machine H includes a holding part A that holds the container 70 and a transfer part B that transfers the container 70. The transfer device 4 includes a transfer lifting body driving part 40M that lifts and lowers the transfer lifting body 40B along the transfer mast 40. Although detailed illustrations are omitted, the transfer lifting body driving part 40M includes, for example: an annular body such as a belt, which is connected to the transfer lifting body 40B; a rotating body, which is wound with the annular body; and a motor that rotationally drives the rotating body. In addition, in the present embodiment, the transfer mast 40 is equivalent to the "mast", and the transfer lifting body 40B is equivalent to the "lifting body".

[0041] In this embodiment, the transfer device 4 can move the transfer machine H (holding unit A and transfer unit B) in the vertical direction, and can move the container 70 relative to the multi-layer shelf unit 80 (see Figure 2 ) for each transfer. In this example, the control unit C for controlling the transfer device 4 is configured as follows: in order to transfer the container 70 relative to the container rack 8, the lifting control of lifting the transfer lifting body 40B is performed. That is, the transfer lifting body 40B is lifted and lowered within a predetermined lifting range.

[0042] In this embodiment, a pair of transfer masts 40 are fixed to the traveling body 1 in a spaced-apart manner along the vehicle body width direction W (see also FIG. Figure 8 The transfer lift 40B is supported so as to be able to be lifted and lowered relative to the pair of transfer masts 40. That is, in the present embodiment, the height dimension Sh is the height from the travel surface on which the travel body 1 travels to the upper end of the transfer mast 40 (see Figure 3 ) In addition, the height to the upper end of the transfer mast 40 is set according to the height of the frame portion 80.

[0043] like Figure 3 , Figure 6 as well as Figure 7 As shown, in the present embodiment, the transfer device 4 includes a first transfer machine H1 and a second transfer machine H2.

[0044] The first transfer machine H1 includes: a first holding portion 41A that holds the container 70; a first locking portion 41Bb that is locked to the container 70; a first transfer drive portion 41Mc that moves the first locking portion 41Bb along each transfer direction Xa, Xb; and a first holding drive portion 41MA that moves the first holding portion 41A along each transfer direction Xa, Xb. In the present embodiment, the first locking portion 41Bb is supported by the first support member 41Bc together with the first pressing portion 41Ba that presses the container 70 toward the unloading side Xa1, Xb1 in each transfer direction. The first support member 41Bc is supported by the first holding portion 41A, and is relatively moved relative to the first holding portion 41A along each transfer direction Xa, Xb by the first transfer drive portion 41Mc. That is, in the present embodiment, the first stopper 41Bb moves integrally with the first pressing portion 41Ba along the transfer directions Xa and Xb as the first supporting member 41Bc moves. In addition, in the present embodiment, the first stopper 41Bb and the first pressing portion 41Ba constitute the first transfer portion 41B for transferring the container 70 between the first holding portion 41A and the transfer target portion T.

[0045] The second transfer machine H2 includes: a second holding portion 42A, which is arranged below the first holding portion 41A and holds the container 70; a second locking portion 42Bb, which is locked to the container 70; a second transfer drive portion 42Mc, which moves the second locking portion 42Bb along each transfer direction Xa, Xb; and a second holding drive portion 42MA, which moves the second holding portion 42A along each transfer direction Xa, Xb. In the present embodiment, the second locking portion 42Bb is supported by the second support member 42Bc together with the second pressing portion 42Ba that presses the container 70 toward the unloading side Xa1, Xb1 in each transfer direction. The second support member 42Bc is supported by the second holding portion 42A, and is relatively moved relative to the second holding portion 42A along each transfer direction Xa, Xb by the second transfer drive portion 42Mc. That is, in the present embodiment, the second stopper 42Bb moves integrally with the second pressing portion 42Ba along the transfer directions Xa and Xb as the second supporting member 42Bc moves. In addition, in the present embodiment, the second stopper 42Bb and the second pressing portion 42Ba constitute the second transfer portion 42B for transferring the container 70 between the second holding portion 42A and the transfer target portion T.

[0046] In this embodiment, the first holding portion 41A and the second holding portion 42A are connected in the up-down direction by the holding connection portion 43. Therefore, the first holding portion 41A and the second holding portion 42A move integrally. In addition, 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.

[0047] In this example, the control unit C for controlling the transfer device 4 is configured as follows: it controls the transfer drive units 41Mc and 42Mc to perform movement control so that the transfer units 41B and 42B move along the transfer directions Xa and Xb. In addition, the control unit C is configured as follows: it controls the holding drive units 41MA and 42MA to perform advance and retreat control so that the holding units 41A and 42A move forward and backward along the transfer directions Xa and Xb. In this embodiment, the first transfer drive unit 41Mc and the second transfer drive unit 42Mc are respectively equivalent to the "moving mechanism", and the first holding drive unit 41MA and the second holding drive unit 42MA are respectively equivalent to the "advance and retreat mechanism".

[0048] The first transfer machine H1 and the second transfer machine H2 are configured to be able to transfer the container 70 to each of the shelf 80 and the stacking area 2A. When the shelf 80 is the transfer target location T, each transfer machine H1, H2 moves the container 70 between each holding portion 41A, 42A and the shelf 80 in the second posture P2, and transfers the container 70 to the shelf 80 (see Figure 5 In addition, when the stacking area 2A is the transfer target area T, each transfer machine H1, H2 moves the container 70 between each holding portion 41A, 42A and the stacking area 2A in the first posture P1, and transfers the container 70 relative to the stacking area 2A (refer to Figure 5 ).

[0049] Figure 6 and Figure 7 1 and 2 , which are explanatory diagrams showing a state in which the transfer device 4 performs a transfer operation (unloading operation or lifting operation) of the container 70 with respect to the rack portion 80 as the transfer target portion T. As shown in FIG.

[0050] Figure 6 The lifting action (transfer action) of the container 70 relative to the rack 80 by the first transfer machine H1 is shown, and the case where the container 70 stored in the rack 80 is lifted to the first holding part 41A by the first transfer part 41B is illustrated. In this case, the control unit C (refer to Figure 3 ) When the position of the first transfer machine H1 is aligned with the reference position 80P (refer to Figure 2 ) After the first stopper 41Bb matches, the container 70 is introduced toward the second transfer direction lifting side Xb2. In this embodiment, the reference position 80P of the rack 80 is detected by the reference position detection sensor Se1 provided in the transfer device 4.

[0051] Figure 7The unloading operation (transfer operation) of the container 70 with respect to the rack 80 by the second transfer machine H2 is shown, and the case where the container 70 held by the second holding portion 42A is unloaded from the rack 80 by the second transfer portion 42B is illustrated. In this case, the control unit C (refer to Figure 3 ) When it is determined that the shelf 80 from which the container 70 is to be removed does not contain other containers 70, the container 70 is pressed toward the second transfer direction removal side Xb1 by the second pressing portion 42Ba. In this embodiment, the container 70 stored in the shelf 80 is detected by the storage container detection sensor Se2 provided in the transfer device 4.

[0052] In addition, as described above, in this embodiment, the lifting device 3 can form a space between the plurality of containers 70 stacked in the stacking area 2A in the vertical direction. And, the transfer device 4 uses these spaces to transfer the container 70 relative to the stacking area 2A. In this embodiment, the transfer device 4 is configured to lift and unload the container 70 relative to the stacking area 2A. Although not shown in the figure, in this example, the transfer device 4 is configured to lift and unload the container 70 in parallel relative to the stacking area 2A.

[0053] Here, the transport vehicle 100 according to the present disclosure performs acceleration limit control as needed when the transfer device 4 transfers the container 70 so as to easily suppress the shaking or tilting caused by the transfer operation of the article.

[0054] Control unit C (refer to Figure 3 ) is configured as follows: when the transfer lift 40B is located above a predetermined reference height h in the lifting range of the transfer lift 40B, acceleration limiting control is performed 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 level than when the transfer lift 40B is located below the reference height h. In the present embodiment, the entire area of ​​the lifting range is divided into two areas, an upper side and a lower side, with the reference height h as a boundary. In addition, in the present example, the area including the reference height h (i.e., the lower side) in the lower area is an area below the reference height h, but is not limited thereto.

[0055] 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 the present embodiment, the reference height h is set to the height of the center of gravity G of the transport vehicle 100. The center of gravity of the transport vehicle 100 is determined in consideration of the mass of each component constituting the transport vehicle 100.

[0056] In this embodiment, if Figure 8As shown, when the container 70 is transferred between the transfer device 4 and the shelf 80 (in other words, when the orientation of the transfer device 4 is the second posture P2 and the container 70 is moved along the second transfer direction Xb by the transfer device 4), and the transfer lifting body 40B is located in an area above the reference height h, the control unit C performs acceleration limiting control to limit the upper limit of the acceleration. Fig. 9 : is a graph showing the correspondence between the height of the lifting body (the height of the transfer lifting body 40B) and the upper limit of the acceleration. Fig. 9 As shown, in this example, by executing the acceleration limit control, the upper limit of the acceleration is limited to a value lower than that in the case where the acceleration limit control is not performed ( Fig. 9 Any lower value ( Fig. 9 That is, in this example, 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 is restricted to "α5".

[0057] In the present embodiment, the upper limit of the moving speed of the container 70 along the second transfer direction Xb by the first transfer machine H1 and the second transfer machine H2 is the same regardless of whether the acceleration limit control is executed. In other words, the upper limit of the moving speed of the container 70 along the second transfer direction Xb by the first transfer machine H1 and the second transfer machine H2 is the same regardless of whether the transfer lift 40B is in the area above or below the reference height h. That is, the control unit C makes the upper limit of the moving speed of the container 70 along the second transfer direction Xb by the first transfer machine H1 and the second transfer machine H2 the same at the upper side and the lower side of the reference height h.

[0058] Here, if the transport vehicle 100 is shaken by causing the holding portions 41A and 42A to move forward and backward in the second transfer direction Xb, the positional relationship with the rack portion 80 changes, and it is easy to become difficult to properly transfer the container 70. On the other hand, the positional relationship between the transfer portions 41B and 42B and the rack portion 80 is determined at the time of movement of the transfer portions 41B and 42B in the second transfer direction Xb (in other words, the movement of the stop portions 41Bb and 42Bb in the second transfer direction Xb), and thus the influence on the transfer operation is small.

[0059] Therefore, in this example, when the transfer lift 40B is located in the area above the reference height h, the control unit C performs the acceleration limit control when the advance and retreat control is performed to make the first holding unit 41A and the second holding unit 42A advance and retreat in the second transfer direction Xb. On the other hand, even when the transfer lift 40B is located in the area above the reference height h, the control unit C does not perform the acceleration limit control when the movement control is performed to make the first transfer unit 41B and the second transfer unit 42B move in the respective transfer directions Xa and Xb. In other words, when the advance and retreat control is performed, if the transfer lift 40B is located in the area above the reference height h, the upper limit of the acceleration is limited by the acceleration limit control, but when the movement control is performed, the upper limit of the acceleration is not limited regardless of whether the transfer lift 40B is located in the area above the reference height h or in the area below the reference height h. That is, the control unit C performs acceleration limiting control on the movement of the container 70 accompanied by the forward and backward movements of the first holding part 41A and the second holding part 42A based on the first holding drive part 41MA and the second holding drive part 42MA, and does not perform acceleration limiting control on the movement of the container 70 accompanied by the movement of the first stopping part 41Bb and the second stopping part 42Bb based on the first transferring drive part 41Mc and the second transferring drive part 42Mc.

[0060] On the other hand, Figure 8 As shown, when the transfer lift 40B is located in the area below the reference height h, the control unit C does not perform the acceleration limit control. In this case, the maximum value in design may actually become the upper limit of the acceleration, but the upper limit of the acceleration may also be limited to a value higher than the upper limit value in the acceleration limit control.

[0061] In this example, when the transfer lift 40B is located in the region below the reference height h, the upper limit of the acceleration is limited so as to become lower as the height of the transfer lift 40B becomes higher. Fig. 9 As shown in FIG. 1 , the upper limit of the acceleration is limited so as to gradually decrease from “α1” to “α4” as the height of the transfer lift 40B increases. That is, the control unit C limits 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 so that in the area on the lower side of the lifting range bounded by the reference height h, the upper limit of the acceleration gradually decreases as it moves from the lower limit of the area toward the upper side.

[0062] In this embodiment, when the container 70 is transferred between the transfer device 4 and the stacking area 2A (in other words, when the transfer device 4 is oriented in the first posture P1 and the container 70 is moved along the first transfer direction Xa by the transfer device 4), the acceleration limit control is not performed regardless of whether the transfer lift 40B is located in the area above the reference height h. In this case, the maximum value in design may actually become the upper limit of the acceleration.

[0063] The above configuration can minimize the shaking or tilting of the transport vehicle 100 caused by the transfer operation of the container 70. In addition, the accuracy of the transfer operation can be reduced, and the need for waiting for the transfer operation can be reduced, thereby improving the efficiency of the transfer operation.

[0064] [Other implementation methods] Next, other embodiments of the transport vehicle will be described.

[0065] (1) In the above-mentioned embodiment, the following scheme is described, but the present disclosure is not limited to this scheme: one reference height h is set, and the entire area of ​​the lifting range is divided into two areas, the upper side and the lower side, with the reference height h as the boundary. It can also be the following scheme: multiple reference heights h are set, and the entire area or a part of the lifting range is divided into three or more areas according to the set multiple reference heights h. In this case, it is appropriate that the upper limit of the acceleration is set so as to become lower in order from the lower area to the upper area. For example, Fig.10 As shown, the following scheme may also be adopted: the first reference height h1 is set to the height of the center of gravity G of the transport vehicle 100, and the second reference height h2 and the third reference height h3 are set to be higher than the first reference height h1, so that the entire lifting range is divided into four areas. In this case, Fig.11 As shown, it is appropriate that the upper limit of the acceleration in the acceleration limit control is set so as to gradually decrease in the order of "β2" as the upper limit (first upper limit) of the region between the first reference height h1 and the second reference height h2, "β3" as the upper limit (second upper limit) of the region between the second reference height h2 and the third reference height h3, and "β4" as the upper limit (third upper limit) of the region above the third reference height h3. In addition, "β1" as the upper limit of the acceleration in the region below the first reference height h1 can be set to a maximum value in design.

[0066] (2) In the above-mentioned embodiment, the following scheme is described, but the present disclosure is not limited to this scheme: when the transfer lift 40B is located in the area above the reference height h, the acceleration limit control is performed when the forward and backward control is performed, and the acceleration limit control is not performed when the movement control is performed. The following scheme may also be used: when the transfer lift 40B is located in the area above the reference height h, the acceleration limit control is performed even when the movement control is performed.

[0067] (3) In the above-mentioned embodiment, the following scheme is described, but the present disclosure is not limited to this scheme: 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 portion 80. 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. In addition, when the center of gravity is not located on the extension of the rotation axis 51 of the rotation device 5 and the container 70 is held on the holding portion A, the acceleration limit control may be performed on the rotation movement.

[0068] (4) In the above-mentioned embodiment, the following scheme is described, but the present disclosure is not limited to this scheme: the upper limit of the acceleration of the movement of the container 70 along the second transfer direction Xb by each transfer machine H1, H2 is limited so that in the area below the reference height h of the lifting range, the upper limit of the acceleration gradually decreases as it moves from the lower limit of the area toward the upper side. For example, Fig.12 As shown, the following scheme may be adopted: in the area on the lower side of the lifting range bounded by the reference height h, the upper limit of the acceleration is limited so that the upper limit of the acceleration is constant at "γ1", and in the area above the reference height h, the upper limit of the acceleration is limited to "γ2" by the acceleration limit control. In addition, the following scheme may be adopted: the upper limit of the acceleration of the movement of the container 70 is limited so that in the entire or a part of the lifting range, the upper limit of the acceleration decreases stepwise or linearly (in other words, continuously) as it moves from the lower limit of the area toward the upper side.

[0069] (5) In addition, the configuration disclosed in the above-mentioned embodiment can also be combined with the configuration disclosed in other embodiments and applied as long as no contradiction occurs. With regard to other configurations, the embodiments disclosed in this specification are merely illustrative in all points. Therefore, various changes can be appropriately made without departing from the scope of the purpose of the present disclosure.

[0070] [Overview of the above-mentioned embodiment] Next, the transport vehicle described above will be described.

[0071] A transport vehicle is a transport vehicle that runs along the front of a storage rack having a shelf portion with multiple layers of storage items in the vertical direction to transport the aforementioned items, and comprises: A traveling body, which travels along a traveling path; A transfer device for transferring the aforementioned articles; and a control unit, which controls the aforementioned transfer device, The aforementioned transfer device comprises: A mast fixed to the traveling body and arranged in an up-down direction; a lifting body that is lifted and lowered along the mast; and A transfer machine, which is supported by the aforementioned lifting body, The direction of the vehicle is defined as the front-rear direction of the vehicle. The transfer machine includes a holding portion for holding the article, and is configured to move the article in a transfer direction intersecting the front-rear direction of the vehicle body when viewed in the vertical direction, and to transfer the article between the holding portion and the rack portion. When the lift body is located above a predetermined reference height within the lift range of the lift body, the control unit performs acceleration limiting control that limits the upper limit of the acceleration of the movement of the article along the transfer direction based on the transfer machine to a lower level than when the lift body is located below the reference height.

[0072] If the transfer action causes the transport vehicle to shake or tilt more, the positional relationship between the article, the shelf and the transfer machine changes, and the transfer action accuracy decreases. In order to suppress such a decrease in accuracy, the transfer action needs to be put on standby until the transport vehicle shakes or tilts. However, according to this configuration, the shaking or tilting of the transport vehicle caused by the transfer operation of the article can be easily suppressed. Therefore, the decrease in the accuracy of such transfer operation can be suppressed, and the necessity of waiting for the transfer operation can be reduced, which can improve the efficiency of the transfer operation. As described above, according to this configuration, it is possible to realize a transport vehicle that can easily suppress the shaking or tilting of the transport vehicle caused by the article transfer operation.

[0073] Here, preferably, the control unit sets the same upper limit of a moving speed of the article along the transfer direction by the transfer machine at a position above and a position below the reference height.

[0074] The acceleration of the article affects the shaking or tilting of the transport vehicle caused by the transfer operation of the article. According to this configuration, by limiting the acceleration, the shaking or tilting of the transport vehicle can be suppressed to a small level. Moreover, the upper limit of the moving speed of the article is made the same in the area above and below the reference height, thereby improving the efficiency of the transfer operation compared to the case where the upper limit of the moving speed of the article in the upper area is limited to be lower than the upper limit of the moving speed of the article in the lower area.

[0075] In addition, preferably, the transfer machine further comprises: a stopper that is stopped by the article; a moving mechanism that moves the stopper along the transfer direction; and an advance and retreat mechanism that moves the holding portion along the transfer direction. The control unit performs the acceleration limiting control on the movement of the article accompanying the forward and backward movement of the holding unit based on the forward and backward mechanism, and does not perform the acceleration limiting control on the movement of the article accompanying the movement of the locking unit based on the moving mechanism.

[0076] According to this configuration, the acceleration limit control is executed only for the forward and backward movement that has a great influence on the shaking or tilting of the transport vehicle, and the acceleration limit control is not executed for the movement of the locking portion of the moving mechanism that has a relatively small influence on the shaking or tilting of the transport vehicle, so that the efficiency of the transfer operation can be improved compared to the case where the acceleration limit control is executed for both. Therefore, the shaking or tilting of the transport vehicle can be effectively suppressed, and the efficiency of the transfer operation can be improved at the same time.

[0077] Furthermore, it is preferable that the reference height is set to a height corresponding to the height of the center of gravity of the transport vehicle.

[0078] The results of verification conducted by the inventors and others show that the movement of the object in the transfer direction above the center of gravity of the transport vehicle has a greater impact on the shaking or tilting of the transport vehicle than the movement of the object in the transfer direction below the center of gravity of the transport vehicle. According to this configuration, the upper limit of the acceleration of the object in the transfer direction above the center of gravity of the transport vehicle is limited to be lower than the upper limit of the acceleration of the object in the transfer direction below the center of gravity of the transport vehicle, thereby suppressing the decrease in the efficiency of the transfer action and suppressing the shaking or tilting of the transport vehicle caused by the transfer action of the object.

[0079] In addition, it is suitable to define the direction orthogonal to the front-rear direction of the vehicle body when viewed in the up-down direction as the vehicle body width direction. The dimension of the vehicle body in the vehicle body width direction is less than 1 / 2 of the dimension of the vehicle body in the vehicle body front-rear direction. A dimension in the vertical direction from the lower end of the traveling body to the upper end of the mast is at least twice a dimension of the traveling body in the vehicle body width direction.

[0080] According to this configuration, the traveling body is long and high in the front-rear direction of the vehicle body, so the transport vehicle is prone to swaying due to the movement of articles in the transfer direction intersecting the front-rear direction of the vehicle body. Therefore, by performing the acceleration limit control, the sway or tilt of the transport vehicle can be effectively suppressed to a small level.

[0081] Furthermore, preferably, the control unit limits an upper limit of acceleration of movement of the article along the transfer direction such that, in at least a portion of the lifting range, the upper limit of acceleration gradually decreases from a lower limit of the region toward an upper side.

[0082] According to this structure, the upper limit of the acceleration is restricted so that in at least a part of the lifting range, it gradually becomes lower as it goes upward, so it is easy to suppress the decrease in the efficiency of the transfer action and at the same time suppress the shaking or tilting of the transport vehicle caused by the transfer action of the article. Industrial Applicability

[0083] The technology according to the present disclosure can be utilized in a transport vehicle that transports articles by traveling along the front of a storage rack having a plurality of shelf portions for storing articles in the vertical direction. Description of Reference Numerals

[0084] 100: Transport vehicle 1: Traveling body 4: Transfer device 8: Container rack (storage rack) 40: Transfer mast (mast) 40B: Lifting body for transfer (lifting body) 41A: First holding portion (holding portion) 41Bb: First locking portion (locking portion) 41MA: 1st holding drive unit (advance and retreat mechanism) 41Mc: 1st transfer drive unit (moving mechanism) 42A: Second holding portion (holding portion) 42Bb: Second locking portion (locking portion) 42Mc: Second transfer drive unit (moving mechanism) 42MA: Second holding drive unit (advance and retreat mechanism) 70: Container (item) 80: Shelf A: Holding part C: Control Department G :center of gravity H: Transfer machine H1: First transfer machine (transfer machine) H2: Second transfer machine (transfer machine) R: Driving path L: Front and rear direction of the vehicle W: vehicle width direction Xb: Second transfer direction (transfer direction) Sl: length dimension Sw : Width size Sh : Height dimension h: reference height.

Claims

1. A transport vehicle that runs along the front of a storage rack having a plurality of layers of shelf portions for storing articles in the vertical direction to transport the articles, comprising: A traveling body, which travels along a traveling path; a transfer device for transferring the articles; and a control unit, which controls the transfer device, The transfer device comprises: A mast fixed to the traveling body and arranged in an up-down direction; a lifting body that is lifted and lowered along the mast; and a transfer machine supported on the lifting body, The direction in which the traveling body travels is the front-rear direction of the vehicle body. The transfer machine includes a holding portion for holding the article, and is configured to move the article in a transfer direction intersecting the front-rear direction of the vehicle body when viewed in the vertical direction, and to transfer the article between the holding portion and the shelf portion. The control unit performs acceleration limiting control for limiting the upper limit of the acceleration of the movement of the article along the transfer direction based on the transfer machine to a lower level than a case where the lift body is located above a predetermined reference height within the lift range of the lift body, compared to a case where the lift body is located below the reference height.

2. The transport vehicle according to claim 1, wherein: The control unit sets the same upper limit of the transfer speed of the article along the transfer direction by the transfer machine above and below the reference height.

3. The transport vehicle according to claim 1 or 2, wherein: The transfer machine further comprises: a stopper that is stopped by the article; a moving mechanism that moves the stopper along the transfer direction; and an advance and retreat mechanism that moves the holding portion along the transfer direction. The control unit performs the acceleration limiting control on the movement of the article accompanying the advancing and retreating action of the holding unit by the advancing and retreating mechanism, and does not perform the acceleration limiting control on the movement of the article accompanying the movement of the locking unit by the moving mechanism.

4. The transport vehicle according to claim 1 or 2, wherein: The reference height is set to a height corresponding to the height of the center of gravity of the transport vehicle.

5. The transport vehicle according to claim 1 or 2, wherein: The direction perpendicular to the front-rear direction of the vehicle body when viewed in the up-down direction is the vehicle body width direction, The dimension of the vehicle body in the vehicle body width direction is less than 1 / 2 of the dimension of the vehicle body in the vehicle body front-rear direction. A dimension in the up-down direction from the lower end of the traveling body to the upper end of the mast is at least twice a dimension of the traveling body in the body width direction.

6. The transport vehicle according to claim 1 or 2, wherein: The control unit limits an upper limit of acceleration of movement of the article along the transfer direction such that the upper limit of acceleration gradually decreases from a lower limit of the region toward an upper side in at least a portion of the lifting range.

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