Transport vehicle

Abstract

To provide a transport vehicle that is highly versatile and can transport diverse types of universal wheel inclusive objects.SOLUTION: A transport vehicle (1) that transports an object having at least two universal wheels includes a pair of side frames (11 and 12) that extends back and forth along both sides of an object (100), a front frame (13) extending between the front ends of the pair of side frames, a center frame (14) extending from the front frame toward backward between the pair of side frames, and arms (30) that expand from the center frame toward the pair of side frames, stretch between two universal wheels, and thus hold the object.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transport vehicle with swivel wheels for transporting an object, for example. [Background technology]

[0002] Patent Document 1 states that "when an automated guided vehicle slips under a transport cart carrying an item, the device automatically couples the transport cart to the automated guided vehicle, allowing the automated guided vehicle to tow the transport cart and move forward, and automatically releases the coupling when the transport cart reaches the destination." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-36644 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 requires a dedicated coupling mechanism for the towed vehicle, and can only be coupled to dedicated vehicles designed from the start for towing. Furthermore, the dedicated coupling mechanism is large in size and requires a certain amount of space, making it impossible to fit it under, for example, an extremely low-floor object with swivel wheels.

[0005] In addition, transport vehicles that tow a towed vehicle require a large footprint when towing or turning, making it difficult to turn in narrow roads and unable to be loaded onto pallets with limited dimensions.

[0006] The present invention has been made in view of the above points, and its object is to provide a highly versatile transport vehicle capable of transporting a wide variety of objects with swivel wheels. [Means for solving the problem]

[0007] The transport vehicle of the present invention that solves the above problems comprises: A transport vehicle for transporting an object having at least two swivel wheels, A pair of side frames extending forward and backward along both sides of the object; a front frame extending between front ends of the pair of side frames; a center frame extending rearward from the front frame between the pair of side frames; an arm extending from the center frame toward the pair of side frames and stretching across the two swivel wheels to grip the object; The present invention is characterized by having the following. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a highly versatile transport vehicle that can transport a wide variety of objects with swivel wheels.

[0009] Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. In addition, problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an overall view of a transport vehicle according to a first embodiment. [Figure 2] 1 is an overall view of a transport vehicle according to a first embodiment. [Figure 3] FIG. 2 is a diagram illustrating the configuration of an arm and an expansion / contraction device in the first embodiment. [Figure 4] FIG. 2 is a diagram illustrating the configuration of an arm and an expansion / contraction device in the first embodiment. [Figure 5] FIG. 2 is a diagram showing the configuration of a lifting device included in the transport device of the first embodiment. [Figure 6] FIG. 2 is a diagram showing a state in which the transport device of the first embodiment is used. [Figure 7] FIG. 2 is a diagram showing an object to be transported by the transport device of the first embodiment, viewed from the bottom side. [Figure 8] FIG. 2 is a bottom view showing a state in which an object is gripped by the conveying device of the first embodiment. [Figure 9] FIG. 10 is an overall view of a transport vehicle according to a second embodiment. [Figure 10] FIG. 10 is an overall view of a transport vehicle according to a second embodiment. [Figure 11] 10A and 10B are diagrams illustrating the configuration of an arm and an expansion / contraction device in a second embodiment. [Figure 12] 10A and 10B are diagrams illustrating the configuration of an arm and an expansion / contraction device in a second embodiment. [Figure 13] FIG. 10 is a diagram showing the configuration of a lifting device included in a transport device according to a second embodiment. [Figure 14] FIG. 10 is a bottom view showing a state in which an object is gripped by the conveying device of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] [First embodiment] Next, a first embodiment of the present invention will be described. 1 and 2 are overall views of the transport vehicle of the first embodiment, with FIG. 1 showing the state when gripping an object and FIG. 2 showing the state before gripping the object.

[0012] The transport vehicle 1 is a device that grips and transports an object 100 having multiple swivel wheels on its bottom surface, and has the function of traveling within a facility such as a factory or warehouse according to a pre-set program to transport the object to its destination.

[0013] The transport vehicle 1 has a frame 10, traveling devices 20A and 20B, an arm 30, a lifting device 40, and a control device 60. The frame 10 has a frame structure that is generally rectangular in plan view, and has a pair of left and right side frames 11 and 12 extending forward and backward, a front frame 13 extending left and right between the front ends of the pair of side frames 11 and 12, a center frame 14 extending rearward from the front frame 13 between the pair of side frames 11 and 12, and rear frames 15A and 15B that open and close the gap between the rear ends of the pair of side frames 11 and 12 and the rear end of the center frame 14.

[0014] The pair of side frames 11, 12 have a length that extends along both sides of the object 100 (see FIG. 5). Each side frame 11, 12 is provided with traveling devices 20A, 20B. The traveling devices 20A, 20B have drive wheels 21 that are driven to rotate back and forth, a drive motor 22, and a gear box 23. Each drive wheel 21 is arranged so that its central axis extends coaxially to the left and right of the side frames 11, 12, and is arranged in the longitudinal center of the side frames 11, 12 so that the turning center is located approximately in the center of the underside 101 of the object 100.

[0015] The rear frames 15A, 15B have their base ends pivotally supported on the rear ends of the pair of side frames 11, 12, and the rear portion of the frame 10 can be opened or closed by swinging their tips toward or away from the center frame 14. As shown in Figure 1, the rear frames 15A, 15B can be selectively positioned between a closed position where the tips of the rear frames 15A, 15B are engaged with the rear end of the center frame 14 to block the space between the rear ends of the pair of side frames 11, 12 and the rear end of the center frame 14, and an open position where the engagement is released to open the space between the rear ends of the pair of side frames 11, 12 and the rear end of the center frame 14, as shown in Figure 2.

[0016] The center frame 14 has a flat plate shape with a predetermined thickness so that it can be inserted between the floor surface on which the object 100 is transported and the underside 101 of the object 100. The center frame 14 is attached to the front frame 13 at the center position in the longitudinal direction of the front frame 13 with the lifting device 40 interposed therebetween.

[0017] 3 and 4 are diagrams illustrating the configuration of the arm and deployment device in the first embodiment, with FIG. 3 showing the arm in an expanded deployed state and FIG. 4 showing the arm in a stored state. An arm 30 is provided on the center frame 14. The arm 30 has a structure that expands and unfolds symmetrically toward the pair of side frames 11, 12 and stretches across at least two free wheels 102A, 102B of the object 100, thereby gripping and connecting the object 100. In this embodiment, the arm 30 is configured to grip and connect the object 100 by stretching across the free wheels 102A and 102B and across the free wheels 103A and 103B.

[0018] The arm 30 has a pair of flat plates 33A, 33B arranged separately on the left and right, and a link mechanism 31 that supports the pair of flat plates 33A, 33B so that they can move toward and away from each other. The link mechanism 31 is supported by the center frame 14 and is configured to be able to expand and contract to the left and right. The link mechanism 31 is configured by crossing multiple flat rod members and connecting them with pins so that they can rotate.

[0019] When expanded and deployed, the link mechanism 31 can cause the pair of flat plates 33A, 33B to protrude to the left and right from the center frame 14. When contracted, the link mechanism 31 can bring the pair of flat plates 33A, 33B closer to each other and store them inside the center frame 14. The center frame 14 is provided with a linear actuator (deployment device) 32 that drives the link mechanism 31. The linear actuator 32 can expand and deploy the link mechanism 31 to press the pair of flat plates 33A, 33B against the swivel wheels 102A, 102B and the swivel wheels 103A, 103B with a predetermined pressing force.

[0020] The outer edges of the pair of flat plates 33A, 33B are provided with recesses 34 and 35 into which swivel wheels 102A, 102B and swivel wheels 103A, 103B are fitted when link mechanism 31 is expanded and deployed. Front recess 34 has a semicircular shape. Rear recess 35 has a semi-elliptical shape with its major axis extending forward and backward. Since the position and spacing of the swivel wheels vary depending on the type of object 100, rear recess 35 is made semi-elliptical so that it can be fitted in accordance with various spacings.

[0021] FIG. 5 is a diagram showing the configuration of the lifting device included in the transport device of the first embodiment. The lifting device 40 is interposed between the front frame 13 and the center frame 14, and has a structure for raising and lowering the center frame 14 relative to the front frame 13. The lifting device 40 presses the drive wheels 21 against the floor surface to ensure sufficient floor friction for the movement of the transport vehicle 1. The lifting device 40 raises the center frame 14 and presses it against the underside 101 of the object 100, applying a force in a direction to lift the object 100, and uses the reaction force to press the drive wheels 21 against the floor surface, improving the grip of the drive wheels 21.

[0022] The lifting device 40 has a base plate 46 fixed to the front frame 13, a slide plate 41 supported so as to be freely movable up and down relative to the base plate 46, a pantograph jack 44 fixed to the front frame 13, and a rotary motor 45 that rotates the screw of the pantograph jack 44.

[0023] An upper plate 43 is provided at the upper end of the slide plate 41, which is bent forward and positioned opposite the top of the pantograph jack 44, and a lower plate 42 is provided at the lower end, which is bent rearward and connected to the center frame 14.

[0024] The lifting device 40 rotates the screw of the pantograph jack 44 by the rotation drive of the rotary motor 45, and the pantograph jack 44 pushes the upper plate 43 upward, which in turn moves the slide plate 41 and the lower plate 42 upward together, thereby lifting the center frame 14. Then, the center frame 14 can be pressed against the underside 101 of the object 100, applying a force in a direction to lift the object 100.

[0025] Based on detection signals from sensors (not shown), the control device 60 controls the drive motors 22 of the traveling devices 20A and 20B, the rotary motor 45 of the lifting device 40, and the linear actuator 32 that extends and retracts the arm 30. The control device 60 is configured by an electronic control device having a CPU and memory, and controls each part by, for example, executing a preset program.

[0026] Figure 6 is a diagram showing the use state of the conveying device of the first embodiment, Figure 7 is a diagram showing the bottom side of an object being conveyed by the conveying device of the first embodiment, and Figure 8 is a diagram showing the bottom side of the object being held by the conveying device of the first embodiment.

[0027] Object 100 is an extremely low-floor object with swivel wheels, such as an inspection device that is large and heavy enough to be manually pushed and moved by one or more workers. Object 100 does not have a towing bracket, and its sides are made of decorative panels. As shown in FIG. 7 , object 100 has a plurality of swivel wheels 102A, 102B, 103A, 103B, 104A, 104B, 105A, and 105B and fixed legs 106A, 106B, 107A, and 107B on its underside 101. These plurality of swivel wheels 102A, 102B, 103A, 103B, 104A, 104B, 105A, and 105B are used when transported by transport vehicle 1.

[0028] Fixing legs 106A, 106B, 107A, and 107B are used to secure object 100, and when moving them, they are retracted further than the swivel wheels by adjusting the screws. After transporting the object to the desired location, the screws are adjusted to protrude further than the swivel wheels, thereby securing the object to the floor. Swivel wheels 102A, 102B, 103A, 103B, 104A, 104B, 105A, and 105B are freely swiveling wheels, and as shown in FIG. 8 , swivel wheels 102A, 102B, 103A, and 103B are configured to be freely swiveling even when a pair of flat plates 33A and 33B of arm 30 are pressed against them and fitted into recesses 34 and 35 to grip and couple the object.

[0029] To have the transport vehicle 1 grasp the object 100, the arm 30 is housed in the center frame 14 and the rear frames 15A and 15B are placed in the open position, as shown in Figure 2. Then, the transport vehicle 1 is moved relatively close to the object 100, and the center frame 14 is inserted between the floor surface and the underside 101 of the object 100, and the center frame 14 is inserted between the swivel wheels 102A and 102B and between the swivel wheels 103A and 103B.

[0030] Then, as shown in FIG. 8, the arm 30 is extended from the center frame 14 toward the pair of side frames 11, 12, and stretched between the swivel wheels 102A and 102B and between the swivel wheels 103A and 103B, thereby gripping and connecting the object 100. As the arm 30 is extended, the swivel wheels 102A, 102B, 103A, and 103B fit into the recesses 34 and 35 of the flat plates 33A and 33B. Then, the rear frames 15A and 15B are positioned in the closed position. As a result, the object 100 is gripped and connected to the transport vehicle 1, and becomes movable as a unit, as shown in FIG.

[0031] Then, from this state, the lifting device 40 lifts the center frame 14 and presses it against the underside of the target object 100, generating a reaction force that presses the drive wheels 21 against the floor surface, ensuring sufficient floor friction for the drive wheels 21 to move. The transport vehicle 1 moves by controlling the traveling devices 20A and 20B.

[0032] When the object 100 is to be detached from the transport vehicle 1, the arm 30 is retracted and stored in the center frame 14 while the vehicle is stopped, and the tension between the swivel wheels 102A and 102B and between the swivel wheels 103A and 103B is released. Then, the rear frames 15A and 15B are placed in the open position, and the transport vehicle 1 is moved in a direction away from the object 100 to detach it.

[0033] Next, the effects of the transport vehicle 1 of this embodiment will be described. The transport vehicle 1 extends the arms 30 from the center frame 14 toward the pair of side frames 11, 12, and stretches them across the space between the swivel wheels 102A and 102B and across the space between the swivel wheels 103A and 103B to grip and couple the object 100. Therefore, it is possible to grip and couple objects 100 of various sizes that have different spacing between the left and right swivel wheels 102A and 102B or between 103A and 103B.

[0034] The transport vehicle 1 grips and couples the object 100 by fitting the swivel wheels 102A, 102B, 103A, and 103B into the recesses 34 and 35 of the pair of flat plates 33A and 33B. Therefore, there is no need to attach a dedicated coupling mechanism to the object 100, and the object 100 itself can be reliably gripped and coupled. Furthermore, the recess 35 has a semi-elliptical shape with its major axis extending in the front-to-rear direction, so it can grip objects 100 of various sizes with different spacing in the front-to-rear direction, such as between the swivel wheels 102A, 102B and 103A, 103B.

[0035] The transport vehicle 1 has an elevator 40 that presses the drive wheels 21 against the floor surface. Therefore, sufficient floor friction can be ensured for the movement of the transport vehicle 1, and tire slippage that may occur when transporting heavy objects on slopes, etc., can be prevented, particularly for lightweight transport vehicles 1.

[0036] The transport vehicle 1 is configured so that the center of rotation is located at the longitudinal center of the side frames 11 and 12, approximately at the center of the underside 101 of the object 100. This reduces the footprint of the transport vehicle when it is moved, making it easier to travel within facilities with many narrow passages, such as factories and warehouses.

[0037] The transport vehicle 1 has a structure in which the rear frames 15A and 15B are connected to the rear end of the center frame 14 to close the open end, thereby providing high rigidity and high running stability.

[0038] The transport vehicle 1 grips and connects to the object 100 to transport it, and can be made smaller and lighter in size than a cart that transports the object 100. Therefore, for example, the size can be made to fit within the pallet dimensions of an autolator used for moving between floors, and the weight can also be kept within the transportable weight limit.

[0039] The transport vehicle 1 has a center frame 14 that has a flat plate shape, and the flat plates 33A, 33B of the arm 30 and the link mechanism 31 are also configured to be thin enough to be housed in the center frame 14, so the center frame 14 can be inserted between the underside 101 of the object 100 and the floor even if the underside 101 of the object 100 is located on an extremely low floor with a low height from the floor.

[0040] In the above embodiment, the arm 30 is configured to expand and deploy symmetrically from the center frame 14 toward the pair of side frames 11, 12 to grasp and connect the object 100, but the configuration of the present invention is not limited to the above configuration. For example, the arm 30 may be stored in the side frames 11, 12 on both sides, and the arm may be deployed inward from each side frame to grasp the object 100. More specifically, the arm may be configured to expand and deploy from the pair of side frames 11, 12 toward the center frame 14 to clamp at least two swivel wheels 102A, 102B of the object 100 together, thereby grasping and connecting the object 100.

[0041] [Second embodiment] Next, a second embodiment of the present invention will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0042] Figures 9 and 10 are overall views of the transport vehicle of the second embodiment, Figures 11 and 12 are views explaining the configuration of the arm and expansion / contraction device in the second embodiment, Figure 13 is a view showing the configuration of the lifting device possessed by the transport device of the second embodiment, and Figure 14 is a view showing the gripping state of an object by the transport device of the second embodiment from the bottom side.

[0043] A feature of this embodiment is that the arm is made lighter by shortening its length, and is expanded and deployed between the two free wheels 102A and 102B to grip and join together.

[0044] An arm 50 is provided on the center frame 14. The arm 50 has a structure that expands and unfolds symmetrically toward the pair of side frames 11, 12 and stretches across the two swivel wheels 102A, 102B of the object 100, thereby grasping and connecting the object 100.

[0045] The arm 50 has a pair of flat plates 53A, 53B arranged separately on the left and right, and a link mechanism 51 that supports the pair of flat plates 53A, 53B so that they can move toward and away from each other. The link mechanism 51 is supported by the center frame 14 and is configured to be expandable and retractable to the left and right. The link mechanism 51 is configured by crossing multiple flat rod members and connecting them with pins so that they can rotate.

[0046] When the link mechanism 51 is expanded and deployed, it can cause the pair of flat plates 53A, 53B to protrude to the left and right from the center frame 14. When the link mechanism 51 is contracted, it can bring the pair of flat plates 53A, 53B closer to each other and store them inside the center frame 14. The center frame 14 is provided with a linear actuator (deployment device) 52 that drives the link mechanism 51. As shown in FIG. 14, for example, the linear actuator 52 can expand and deploy the link mechanism 51 to press the pair of flat plates 53A, 53B against the swivel wheels 102A, 102B with a predetermined pressing force.

[0047] The outer edges of the pair of flat plates 53A, 53B are provided with recesses 54 into which the free wheels 102A, 102B are fitted when the link mechanism 51 is expanded and deployed. The recesses 54 have a semicircular shape.

[0048] Positioning stoppers 56A and 56B are provided at the base end of the center frame 14. When the center frame 14 is inserted between the underside 101 of the object 100 and the floor, the positioning stoppers 56A and 56B come into contact with the swivel wheels 104A and 104B of the object 100, thereby positioning the object 100 relative to the transport vehicle 1 in the front-to-rear direction.

[0049] The front frame 13 is provided with a pair of left and right auxiliary wheels 24. The auxiliary wheels 24 can assist the transport vehicle 1 in stable driving, and can also stabilize the posture of the frame 10 when the object 100 is not held and coupled. The auxiliary wheels 24 are supported so as to be freely movable in the vertical direction, and are biased downward by springs. The auxiliary wheels 24 serve to absorb displacement that occurs when the transport vehicle 1 moves over steps or slopes on the floor while holding and coupling the object 100.

[0050] The lifting device 40 has a slide upper member 411 supported on a base plate 46 of the front frame 13 via a first linear guide 412 so as to be freely movable up and down. The slide upper member 411 has a generally T-shape in plan view, with a tip end 411a that protrudes above the front frame 13 in a direction intersecting the front frame 13, and a base end 411b that extends from one end of the tip end 411a toward the left and right side frames 11 in directions that separate them. A pantograph jack 44 is disposed between the tip end 411a and the front frame 13, and the slide upper member 411 is moved up and down relative to the front frame 13 by extension and contraction of the pantograph jack 44.

[0051] A slide plate 414 is supported on the base end 411b of the slide upper member 411 via a second linear guide 413 so as to be movable up and down. A lower plate 42 that protrudes rearward and is connected to the center frame 14 is provided at the lower end of the slide plate 414. A compression spring 416 is interposed between the slide plate 414 and the slide upper member 411, and the slide plate 414 is urged upward so as to approach the slide upper member 411.

[0052] The compression spring 416 adjusts the force pressing the center frame 14 against the bottom surface of the object 100. The compression spring 416 can absorb displacement between the wheels caused by the positional relationship between the swivel wheels 102A, 102B, 103A, 103B of the object 100 and the drive wheels 21 of the transport vehicle 1 when the transport vehicle 1 travels while holding and connecting to the object 100 and overcomes steps or slopes on the floor surface.

[0053] For example, when gripping and coupling with the object 100, the pantograph jack 44 is used to raise the slide upper member 411, pressing the center frame 14 against the bottom surface of the object 100. Then, by further raising the slide upper member 411, the slide plate 414 is moved upward relative to the slide plate 414, compressing the compression spring 416. Then, the slide position is adjusted so that the displacement of the compression spring 416 is at the center position of the spring extension amount, and the object 100 is brought into a state in which it is supported with cushioning so that it can move up and down.

[0054] As a result, when the transport vehicle 1 goes over a step on the floor, the expansion and contraction of the compression spring 416 can absorb the displacement that occurs between the drive wheels 21 of the transport vehicle 1 and the swivel wheels 102A, 102B, 103A, and 103B of the object 100. This ensures a sufficient pressing force of the object 100 against the center frame 14, preventing the drive wheels 21 from slipping and the transport vehicle 1 from being damaged by an overload.

[0055] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as defined in the claims. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0056] 1. Transport vehicle, 10. Frame, 11. Right side frame (side frame), 12. Left side frame (side frame), 13. Front frame, 14. Center frame, 15A, 15B. Rear frame, 20A, 20B. Traveling device, 21. Drive wheel, 30, 50. Arm, 31, 51. Link mechanism, 32, 52. Linear actuator (deployment device), 33A, 33B. Flat plate, 34, 35, 54. Recess, 40. Lifting device, 56A, 56B. Stopper

Claims

1. A transport vehicle for transporting an object having at least two swivel wheels, A pair of side frames extending forward and backward along both sides of the object; a front frame extending between front ends of the pair of side frames; a center frame extending rearward from the front frame between the pair of side frames; an arm extending from the center frame toward the pair of side frames and stretching across the two swivel wheels to grip the object; A transport vehicle comprising:

2. a traveling device disposed at a central position of the pair of side frames and having a driving wheel that is driven to rotate back and forth; 2. The transport vehicle according to claim 1, further comprising:

3. an elevating device disposed at a central position of the front frame and configured to elevate the center frame and press it against the underside of the object; 2. The transport vehicle according to claim 1, further comprising:

4. a deployment device that expands and contracts the arms; 2. The transport vehicle according to claim 1, further comprising:

5. 2. The transport vehicle according to claim 1, further comprising a rear frame that opens and closes the gap between the rear ends of the pair of side frames and the rear end of the center frame.

6. 2. The transport vehicle according to claim 1, wherein the arm has a recess into which the swivel wheel is fitted when the arm is expanded.

7. When the object has four of the swivel wheels on the bottom surface of the object, 7. The transport vehicle according to claim 6, wherein the arms have recesses into which the free wheels are fitted one by one.

8. 8. The transport vehicle according to claim 7, wherein the arms have recesses into which two of the free wheels are fitted.

9. 2. The transport vehicle according to claim 1, wherein the center frame has a stopper that abuts against the object and positions it relative to the object by bringing the center frame relatively close to the object and inserting the center frame between the two swivel wheels.

10. A transport vehicle for transporting an object having at least two swivel wheels, A pair of side frames extending forward and backward along both sides of the object; a front frame extending between front ends of the pair of side frames; a center frame extending rearward from the front frame between the pair of side frames; an arm extending from the pair of side frames toward the center frame to clamp the two swivel wheels together to grip the object; A transport vehicle comprising:

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