Transport System

Abstract

To achieve a conveyance system that improves the stability of a loading platform that moves up and down along a guide rail.SOLUTION: A conveyance system 1 includes: a loading platform 33 provided with a groove 331 that is guided along a guide rail 21 extending in a vertical direction; and a lifting mechanism 32 that lifts and lowers the loading platform 33. The conveyance system 1 lifts and lowers the loading platform 33 while pressing a rear side face of the groove 331 against the guide rail 21 when a movement direction of an article being conveyed from the loading platform 33 is defined as a forward direction and its opposite direction is defined as a backward direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a transport system. [Background technology]

[0002] Patent Document 1 discloses a technique for easily adjusting the height of a workpiece on a transport vehicle. The transport vehicle disclosed in Patent Document 1 has a vehicle body equipped with a traveling mechanism, a mounting section on which the workpiece is placed, a lifting cylinder that urges the mounting section upward so that it can be raised and lowered relative to the vehicle body, and an engaging section (lifting guide roller) attached to the mounting section. An elevation guide rail with an inclined region is provided on the upstream side of the travel direction of the transport vehicle. As the transport vehicle travels, the engaging section engages with the inclined region of the elevation guide rail to raise and lower the mounting section, thereby enabling the workpiece to be positioned at a height that allows it to be loaded and unloaded. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5912459 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the technique described in Patent Document 1, when the mounting table is raised or lowered, a moment is generated around the base end of the lifting cylinder, which may cause the mounting table to vibrate.

[0005] The present disclosure has been made in consideration of such problems, and provides a transport system that improves the stability of a mounting table that moves up and down along guide rails. [Means for solving the problem]

[0006] A transport system according to one aspect of the present disclosure includes: a mounting table provided with a groove that is guided along a guide rail extending in the vertical direction; a lifting mechanism for lifting and lowering the mounting table; A transport system comprising: When the moving direction of the article carried out from the platform is defined as the forward direction and the opposite direction as the rearward direction, the platform is raised and lowered while the rear side of the groove is pressed against the guide rail. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to realize a transport system that improves the stability of a platform that moves up and down along a guide rail. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a transport system according to a first embodiment. [Figure 2] 3A to 3C are diagrams illustrating the operation of the transport system 1 according to the first embodiment. [Figure 3] 5A to 5C are diagrams illustrating a specific example of a method for generating a pressing force in the conveyance system according to the first embodiment. [Figure 4] 5A to 5C are diagrams illustrating a specific example of a method for generating a pressing force in the conveyance system according to the first embodiment. [Figure 5] 5A to 5C are diagrams illustrating a specific example of a method for generating a pressing force in the conveyance system according to the first embodiment. [Figure 6] 5A to 5C are diagrams illustrating a specific example of a method for generating a pressing force in the conveyance system according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Specific embodiments to which the present disclosure is applied will be described in detail below with reference to the drawings. However, the present disclosure is not limited to the following embodiments. In addition, the following description and drawings have been simplified as appropriate for clarity of explanation.

[0010] Embodiment 1 The transfer system according to the first embodiment will be described below with reference to the drawings. FIG. 1 is a diagram illustrating the configuration of the transfer system 1 according to the first embodiment. A schematic top view is shown on the upper side, and a schematic side view is shown on the lower side. The transfer system 1 includes a post 2 and a transfer robot 3.

[0011] Post 2 is a rack that stores items (e.g., returnable boxes) in multiple tiers. Post 2 has a housing consisting of a top plate, side plates, shelf plates, etc. Items are supported on the shelf plates. The shelf plates may have gaps to allow an arm, which will be described later, to pass through. Portions of post 2 that are hidden by the top plate and side plates are shown with dotted lines.

[0012] A guide rail 21 extending in the vertical direction is provided on the front surface of the post 2, i.e., the opening surface. The guide rail 21 is, for example, a plate-like member erected on each of a pair of side plates of the housing. The distance between the two guide rails 21 is wider than the width of the article to be put in and taken out of the post 2. The article is put in and taken out between the two guide rails 21. A gap is provided between the lower end of the guide rail 21 and the ground, allowing the transport robot 3 to enter.

[0013] The transfer robot 3 includes a traveling unit 31 , a lifting mechanism 32 , and a platform 33 .

[0014] The traveling unit 31 includes a mobile body 311 and wheels 312 rotatably mounted on the mobile body 311. The traveling unit 31 also includes a motor (not shown) that rotates the wheels 312. The motor rotates the wheels 312 in response to a control signal, causing the mobile body 311 to move to any position. The traveling unit 31 may also be driven with a groove 331 (described later) engaged with the guide rail 21, causing the side surface of the groove 331 to be pressed against the guide rail 21.

[0015] The lifting mechanism 32 is provided on the moving body 311 and lifts and lowers the mounting table 33. The lifting mechanism 32 may be configured as a telescopic mechanism that extends and contracts in the vertical direction.

[0016] The mounting table 33 may be provided at the tip of the lifting mechanism 32. An article is placed on the mounting table 33. A groove 331 is provided in the mounting table 33. The groove 331 extends along the thickness direction of the mounting table 33. The groove 331 is guided along the guide rail 21 of the post 2. The groove 331 may be provided on each of the left and right side surfaces of the mounting table 33. The groove 331 is designed to mate with the guide rail 21. Typically, the width of the groove 331 is set to be slightly larger than the width of the guide rail 21.

[0017] The groove 331 includes a side surface 4a, a side surface 4b, and a bottom surface 4c. The side surface 4a is referred to as the rear side surface, and the side surface 4b is referred to as the front side surface. The direction in which the article is carried out from the mounting table 33 moves is referred to as the front direction, and the opposite direction is referred to as the rear direction. In other words, the direction in which the post 2 exists relative to the transport robot 3 is referred to as the front direction.

[0018] An arm (not shown) may be provided on the mounting table 33. The arm extends horizontally while engaging with an item placed on the mounting table 33, and stores the item in the post 2. The item may move forward on the mounting table 33, thereby carrying out the item on the mounting table 33. The arm may also contract horizontally while engaging with an item stored in the post 2, and transfer the item to the mounting table 33. The item may also move backward on the mounting table 33, thereby carrying the item onto the mounting table 33. The arm may be equipped with a hook that engages with the item, or may be equipped with a hand that grasps the item. Note that a transfer means (e.g., an arm) for transferring an item may be provided on the post 2, rather than the transport robot 3.

[0019] The mounting table 33 may be configured to be movable in the front-rear direction. In this case, the mounting table 33 is driven forward with the groove 331 and the guide rail 21 engaged, and the rear side surface 4a of the mounting table 33 is pressed against the guide rail 21.

[0020] The transfer robot 3 includes a control unit (not shown) that controls the traveling unit 31 and the lifting mechanism 32. The control unit includes a processor, a memory, etc. The functions of the control unit may be realized by the processor loading a program into the memory and executing it.

[0021] The control unit controls the rotation of the wheels 312 by sending control signals to each motor of the traveling unit 31, and moves the mobile body 311 to any position. The control unit extends or retracts the extension mechanism by sending control signals to rotation devices such as motors that constitute the lifting mechanism 32, and controls the height of the mounting table 33.

[0022] Alternatively, the control unit may send a control signal to an actuator (e.g., a mechanism for driving the mounting table 33 in the forward and backward directions, or the traveling unit 31) to press the rear side surface 4a of the groove 331 against the guide rail 21. The center of gravity of the transport robot 3 may be set so that the side surface 4a is pressed against the guide rail 21. In this case, the transport robot 3 does not need to actively generate a force (called a pressing force) that presses the side surface 4a against the guide rail 21.

[0023] When taking an article in or out of post 2, transport robot 3 travels to a point where groove 331 is located directly below guide rail 21. When storing an article in post 2, an article (not shown) is placed on mounting table 33. Then, lifting mechanism 32 raises mounting table 33. Guidance of groove 331 begins from the lower end of guide rail 21.

[0024] The width of the groove 331 is set to be larger than the thickness of the guide rail 21. Therefore, a gap exists between the groove 331 and the guide rail 21. As a result, in the conventional technology, there is a risk that the mounting table 33 may rattle and vibrate. In addition, because there is a gap between the groove 331 and the guide rail 21, the position of the mounting table 33 is not fixed, which causes a problem of reduced accuracy in controlling the position of the mounting table 33.

[0025] In the transfer system 1, the mounting table 33 is raised and lowered while the rear side surface 4a of the groove 331 is pressed against the guide rail 21. This makes it possible to prevent the mounting table 33 from wobbling. In addition, the accuracy of the position control of the mounting table 33 is improved.

[0026] 2 is a diagram illustrating the operation of the conveying system 1. The rear side surface 4a of the groove 331 is pressed against the guide rail 21. When an article is carried out from the platform 33 and stored in the post 2, a moment is generated from the platform 33 toward the post 2, centered around the base end (lower end) of the lifting mechanism 32. Because the rear side surface 4a of the groove 331 is in contact with the guide rail 21, a moment is generated that cancels out the moment. Therefore, the platform 33 does not rattle. The same applies when moving an article from the post 2 onto the platform 33.

[0027] If the height of the mounting table 33 is high, the pressing force may actually be small due to the deflection and rigidity of the lifting mechanism. Therefore, the conveyance system 1 may increase the force of the actuator as the height of the mounting table 33 increases. The actuator is, for example, a motor that drives the traveling unit 31 or an actuator that moves the mounting table 33 in a parallel direction.

[0028] Furthermore, if the weight of the article placed on the platform 33 is heavy, the moment around the base end of the lifting mechanism 32 becomes large, and the pressing force may become too strong. Therefore, the control unit of the conveying system 1 may reduce the force applied by the actuator as the weight of the article placed on the platform 33 increases.

[0029] Furthermore, if the pressing force is too strong, the load due to friction increases, causing vibration due to stick-slip. On the other hand, if the pressing force is too weak, the intended effect cannot be achieved. Therefore, the control unit of the transport robot 3 may control the pressing force so that it falls within a predetermined range. Also, rollers or sliding members may be provided on the side surface 4a.

[0030] A sensor (e.g., a limit switch or a photoreflector) (not shown) may be provided on the side surface 4a of the mounting table 33 to detect whether the side surface 4a is pressed against the guide rail 21. By checking the detection result of the sensor, it is possible to reliably press the side surface 4a against the guide rail 21. Also, a sensor may be provided to measure the magnitude of the pressing force.

[0031] It is not necessary for the side surface 4a to be pressed against the guide rail 21 from the moment when the guide rail 21 and the groove 331 start to engage with each other. If the height is low, the shaking of the mounting table 33 is small, so rattles may not occur. In this case, the side surface 4a may be pressed against the guide rail 21 from the moment the height of the mounting table 33 reaches a predetermined height or above. Also, if the weight of the article is small, the shaking of the mounting table 33 may be small. Therefore, if the weight of the article placed on the mounting table 33 is equal to or less than a predetermined value, the side surface 4a may not be pressed against the guide rail 21.

[0032] Next, a specific example of a method in which the conveyance system 1 generates a pressing force will be described with reference to Fig. 3 to Fig. 6. Fig. 3 shows a method in which the side surface 4a is pressed against the guide rail 21 by controlling the driving of the traveling unit 31. The wheels 312 are driven in the direction indicated by the arrow. The traveling unit 31 is driven forward.

[0033] 4 shows a method for pressing the side surface 4a against the guide rail 21 by sliding the mounting table 33 in the horizontal direction. A plate-shaped member 34 is attached to the tip of the lifting mechanism 32. The mounting table 33 is attached so that it can slide in the front-to-rear direction relative to the plate-shaped member 34. The transport robot 3 is equipped with a drive mechanism for sliding the mounting table 33. The mounting table 33 is driven forward as shown by the arrow, and the side surface 4a is pressed against the guide rail 21.

[0034] FIG. 5 shows a method in which the mounting table 33 leans against the guide rail 21 to press the side surface 4a against the guide rail 21. The center of gravity of the mounting table 33 is located forward of the tip of the lifting mechanism 32. The symbol G represents the position of the center of gravity. Therefore, as shown by the arrow, a moment is generated that moves forward with the base end of the lifting mechanism 32 as the center, and the side surface 4a of the groove 331 is pressed against the guide rail 21. At this time, the transport robot 3 does not need to actively generate a pressing force.

[0035] 6 shows a method of pressing the side surface 4a against the guide rail 21 using a robot arm. A robot arm 35 is attached to the tip of the lifting mechanism 32, and a mounting table 33 is provided at the tip of the robot arm 35. The robot arm 35 can move the mounting table 33 in the front-to-rear direction. As shown by the arrow, the robot arm 35 drives the mounting table 33 forward, and the side surface 4a of the groove 331 is pressed against the guide rail.

[0036] The method for generating the pressing force is not limited to the examples shown in Figures 3 to 6. For example, a magnet may be provided on the side surface 4a of the groove 331 or on the guide rail 21, and a pressing force due to magnetic force may be used.

[0037] In the transfer system according to the first embodiment, the rear side surface of the groove of the mounting table is pressed against the guide rail, thereby improving the stability of the mounting table.

[0038] The above-mentioned programs include instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions. The programs may be stored on a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray® disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The programs may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0039] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0040] 1. Transport system 2 posts 21 Guide rail 3. Transport robot 31 Running part 311 Mobile body 312 wheels 32 Lifting mechanism 33 Mounting table 34 Plate-shaped member 35 Robot Arm 331 Groove 4a, 4b side 4c Bottom

Claims

1. a mounting table provided with a groove that is guided along a guide rail extending in the vertical direction; a lifting mechanism for lifting and lowering the mounting table; A transport system comprising: When the moving direction of the article carried out from the platform is defined as the forward direction and the opposite direction is defined as the backward direction, the platform is raised and lowered while pressing the rear side surface of the groove against the guide rail, Using an actuator, the rear side surface is pressed against the guide rail; The force exerted by the actuator increases as the height of the mounting table increases. Conveying system.

2. The heavier the object placed on the platform, the smaller the force exerted by the actuator. The transport system according to claim 1 .

3. a control unit that controls the actuator so that the force with which the rear side surface is pressed against the guide rail is within a predetermined range; 3. A transport system according to claim 1 or 2.

4. a sensor for detecting whether the rear side surface is pressed against the guide rail; The transport system according to claim 1 .

5. a mounting table provided with a groove that is guided along a guide rail extending in the vertical direction; a lifting mechanism for lifting and lowering the mounting table; A transport system comprising: When the moving direction of the article carried out from the platform is defined as the forward direction and the opposite direction is defined as the backward direction, the platform is raised and lowered while pressing the rear side surface of the groove against the guide rail, a sensor for detecting whether the rear side surface is pressed against the guide rail; Conveying system.

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