Automated guided vehicles

Abstract

The present invention provides an automated guided vehicle (AGV) that can automatically attach to and detach from the transported object, and can tow the transported object in a stable manner. [Solution] An automated guided vehicle for towing a transported object equipped with casters, comprising: a drivable vehicle body; a connecting member that can be connected to a connecting member attached to the transported object; and a lifting member that raises and lowers the connecting member from the vehicle body toward the connecting member to connect the connecting member to the connecting member.

Description

Technical Field

[0001] The present invention relates to an automated guided vehicle.

Background Art

[0002] An automated guided vehicle that tows a conveyed object equipped with casters is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For an automated guided vehicle, it is desired that the vehicle automatically couples to the conveyed object, stably tows the conveyed object, then automatically releases the coupling and places the conveyed object at the destination.

[0005] Accordingly, an object of the present invention is to provide an automated guided vehicle that can automatically couple to and release the coupling from a conveyed object, and can tow the conveyed object in a stable state.

Means for Solving the Problems

[0006] The above objective is an automated guided vehicle for towing a transported object equipped with casters, comprising: a drivable body; a connecting member that can be connected to a connecting member attached to the transported object; and a lifting member that raises and lowers the connecting member from the body toward the connecting member to connect the connecting member, wherein one of the connecting member and the connecting member has a ball and a cylindrical case that exposes the ball by exposing a part of the ball from the tip facing the other of the connecting member and the connecting member, and the other is positioned so that it moves inward as it moves away from the one facing the other. This can be achieved by an automated guided vehicle (AGV), which has a conical surface with a decreasing diameter, an inner cylindrical surface located opposite to the conical surface and facing the one mentioned above, having an inner diameter smaller than the minimum inner diameter of the conical surface, and into which the ball and the tip of the case can be loosely fitted, and a continuous slope extending from the conical surface to the inner cylindrical surface, wherein the connected member is connected to the connecting member by the tip of the case being loosely fitted together with the ball within the inner cylindrical surface, and the case can contact the slope without contacting the conical surface while the ball is in contact with the slope. [Effects of the Invention]

[0007] This system provides an automated guided vehicle (AGV) that can automatically attach to and detach from the transported object, and can tow the transported object in a stable state. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an external perspective view of the automated guided vehicle and its trolley. [Figure 2] Figure 2 is a top view of the automated guided vehicle and its trolley. [Figure 3] Figure 3 is a front view of the automated guided vehicle and its trolley. [Figure 4] Figure 4 is a side view of the automated guided vehicle and the trolley. [Figure 5] Figure 5A is a perspective view of the receiving member's external appearance, and Figure 5B is an explanatory diagram showing the state in which a ball caster is connected to the receiving member. [Figure 6]Figure 6A shows the receiving member and ball caster when the automated guided vehicle is stopped with its central axis misaligned, and Figure 6B shows the receiving member and ball caster when the ball is in contact with the conical surface. [Figure 7] Figure 7A shows the state of a ball as it moves from the conical surface to the inner cylindrical surface, and Figure 7B is a magnified view of the area around the slope in Figure 7A. [Figure 8] Figure 8A is an explanatory diagram of the receiving member of the comparative example, and Figure 8B is an enlarged view of Figure 8A. [Figure 9] Figure 9 is a magnified view of the area around the slope. [Modes for carrying out the invention]

[0009] [Automated guided vehicle 1 and trolley 100] Figure 1 is an external perspective view of the automated guided vehicle (AGV) 1 and the trolley 100. Figure 2 is a top view of the AGV 1 and the trolley 100. Figure 3 is a front view of the AGV 1 and the trolley 100. Figure 4 is a side view of the AGV 1 and the trolley 100. The trolley 100 is an example of an object to be towed by the AGV 1. The trolley 100 is movable with four casters 130. The object to be transported is not limited to the trolley 100, but can be anything that is movable with casters. For example, the object to be transported may be a cart, cabin, rack, pallet, wagon, or shelf with casters.

[0010] The trolley 100 has a pair of pipes 101, 102, 103, and 104 on the left side and a pair of pipes 101, 102, 103, and 104 on the right side. Pipes 101 and 102 are spaced horizontally apart from each other, parallel vertically, and of the same length. Pipes 103 and 104 are spaced vertically apart from each other, parallel horizontally, and of the same length. Pipe 103 connects the upper end of pipe 101 to the upper end of pipe 102. Pipe 104 connects the middle section of pipe 101 to the middle section of pipe 102. Casters 130 are attached to the lower ends of each of the two pipes 101 and the lower ends of the two pipes 102. The casters 130 are of the push-in type.

[0011] Pipes 111, 112, and 113 are connected between the two pipes 101. Similarly, pipes 111, 112, and 113 are connected between the two pipes 102. Pipes 111, 112, and 113 are vertically separated from each other, parallel horizontally, and of equal length. Pipe 112 is located above pipe 111. Pipe 113 is located above pipe 112.

[0012] Two pipes 121 are connected between two pipes 111. The two pipes 121 are spaced apart from each other in the direction in which pipes 111 extend and are parallel to each other in the horizontal direction perpendicular to pipes 111. The two pipes 121 are positioned near the center of the length of pipe 111. Two ball casters 40 are attached to the lower part of the two pipes 121. One of the two ball casters 40 is positioned near one end of the two pipes 121. The other of the two ball casters 40 is positioned near the other end of the two pipes 121. The ball casters 40 are an example of one of the connected members and one of the connecting members.

[0013] Four pipes 122 are connected between the two pipes 112. The four pipes 122 are spaced apart from each other in the direction in which pipe 111 extends and are parallel to pipe 121. The four pipes 122 are arranged at equal distances from each other.

[0014] The automated guided vehicle (AGV) 1 is capable of moving with wheels (not shown). The AGV 1 may operate based on a predetermined program or the like. The AGV 1 may recognize track lines or the like provided on the floor surface using sensors and operate based on information obtained from there. The AGV 1 may operate based on user input information.

[0015] The automated guided vehicle 1 is sized to allow access to the underside of the ball caster 40 from between two pipes 101 or between two pipes 102. The automated guided vehicle 1 comprises a body 10, a lifting platform 12, two support plates 14, and two receiving members 20. The body 10 is equipped with wheels (not shown) and incorporates actuators for driving the wheels. The lifting platform 12 is positioned on the upper surface of the body 10. As shown in Figures 3 and 4, the lifting platform 12 is provided to be able to move up and down relative to the body 10 via a rod 11. The rod 11 extends vertically and is able to move up and down vertically. The rod 11 is, for example, part of an electric cylinder built into the body 10. Note that the power source for the lifting platform 12 to move up and down is not limited to an electric cylinder, but may be, for example, an air cylinder. The lifting platform 12 is an example of a lifting member.

[0016] The support plate 14 is a thin, elastic metal plate. The support plate 14 has a fixing portion 141 and a support portion 142. The fixing portion 141 is attached to the upper surface of the lifting platform 12. The support portion 142 is bent relative to the fixing portion 141 so as to be parallel to the upper surface of the lifting platform 12 and spaced apart from the lifting platform 12. Two support plates 14 are installed on the lifting platform 12 so that the two support portions 142 face each other. Two receiving members 20 are positioned on the support portions 142 of the two support plates 14. In this way, the two receiving members 20 are elastically cantilevered by the support portions 142, spaced apart from the upper surface of the lifting platform 12. In addition, a partial opening 143 is provided between the fixing portion 141 and the support portion 142. This facilitates the elastic deformation of the support portion 142 relative to the fixing portion 141.

[0017] As will be described later in detail, when the lifting platform 12 rises, the receiving member 20 is automatically connected to the ball caster 40. Further, when the lifting platform 12 descends from this state, the receiving member 20 is separated from the ball caster 40 and the connection is released. When the receiving member 20 and the ball caster 40 are connected, the aforementioned support portion 142 deflects, and after the connection is completed, the deflection of the support portion 142 is released. As will be described later in detail, this allows the receiving member 20 and the ball caster 40 to be stably connected. The support plate 14 is an example of an elastic support member.

[0018] Figures 1 to 4 show a state where two receiving members 20 face two ball casters 40 respectively in the vertical direction. When the lifting platform 12 rises in the state of Figures 1 to 4, the two receiving members 20 are connected to the two ball casters 40 respectively. As a result, the automated guided vehicle 1 tows the trolley 100 and travels to a predetermined position. When the automated guided vehicle 1 stops at the predetermined position, the lifting platform 12 descends, and the two receiving members 20 separate from the two ball casters 40 respectively. In this manner, the automated guided vehicle 1 transports the trolley 100 to the predetermined position. The receiving member 20 is an example of the other of the connected member and the connecting member.

[0019] [Receiving Member 20 and Ball Caster 40] Figure 5A is an external perspective view of the receiving member 20. The receiving member 20 has an outer cylindrical surface 21, a bottom surface 22, a conical surface 24, an inclined surface 26, and an inner cylindrical surface 28. The receiving member 20 has a predetermined thickness and is substantially disc-shaped. The outer cylindrical surface 21 is cylindrical. A groove 21a extending in the circumferential direction is formed on the outer cylindrical surface 21. The bottom surface 22 is formed to be flat. When facing the ball caster 40 in the vertical direction, the inner diameter of the conical surface 24 decreases as the distance from the ball caster 40 increases. The inclination angle of the conical surface 24 with respect to the horizontal direction is constant. This inclination angle is, for example, an angle smaller than 45 degrees, but the inclination angle with respect to the horizontal direction may be varied. The inclined surface 26 is curved from the conical surface 24 toward the inner cylindrical surface 28. The inclined surface 26 will be described later in detail.

[0020] The inner cylindrical surface 28 is located opposite the ball caster 40 to the conical surface 24 when it is perpendicular to the ball caster 40. The inner cylindrical surface 28 has an inner diameter smaller than the minimum inner diameter of the conical surface 24. The tip of the cylindrical portion 46 of the case 44 of the ball caster 40, which will be described later, can be loosely fitted into the inner cylindrical surface 28. The central axis A2 is the axis that passes through the center of the receiving member 20. The central axis A2 passes through the center of the conical surface 24 and the center of the inner cylindrical surface 28. When the automated guided vehicle 1 is placed on a horizontal plane, the central axis A2 is approximately parallel to the vertical direction. The conical surface 24 is provided on the automated guided vehicle 1 in this way so that it faces vertically upward.

[0021] Figure 5B is an explanatory diagram showing the state in which the ball caster 40 is connected to the receiving member 20. The receiving member 20 is shown in a cross-section including the central axis A2. The ball caster 40 has a mounting plate 42, a case 44, and a ball 48. The mounting plate 42 is plate-shaped and is attached to the two pipes 121 by fastening members such as bolts or screws. The case 44 is fixed to the mounting plate 42.

[0022] The case 44 has a flange portion 45 and a cylindrical portion 46. The flange portion 45 is fixed to the mounting plate 42 by fastening members such as bolts or screws. The outer diameter of the flange portion 45 is larger than the outer diameter of the cylindrical portion 46. The cylindrical portion 46 is cylindrical in shape and extends vertically downward from the flange portion 45. The cylindrical portion 46 holds the ball 48 so that a portion of the ball 48 is exposed and the ball 48 can rotate in any direction. The outer diameter of the cylindrical portion 46 is smaller than the inner diameter of the inner cylindrical surface 28. In this way, the ball caster 40 is attached to the trolley 100 so that the ball 48 faces vertically downward.

[0023] The cylindrical portion 46 has a tip surface 461, a curved surface 462, and an outer cylindrical surface 463. The tip surface 461 has a circular opening that exposes a portion of the ball 48. Since this opening is smaller than the outer diameter of the ball 48, only a portion of the ball 48 is exposed through this opening. Therefore, a portion of the ball 48 protrudes from the tip surface 461. The outer cylindrical surface 463 is located on the opposite side from the receiving member 20 than the tip surface 461 when facing the receiving member 20 in the vertical direction. The outer diameter of the outer cylindrical surface 463 is larger than the outer diameter of the ball 48 and smaller than the inner diameter of the inner cylindrical surface 28. The curved surface 462 is curved in an R-shape from the tip surface 461 to the outer cylindrical surface 463. The central axis A4 is the axis that passes through the center of the ball caster 40. The central axis A4 passes through the center of the cylindrical portion 46 and the center of the ball 48. When the trolley 100 is placed on a horizontal plane, the central axis A4 is approximately parallel to the vertical direction.

[0024] As shown in Figure 5B, the receiving member 20 is connected to the ball caster 40 by the loose fit of the outer cylindrical surface 463 of the cylindrical portion 46 of the case 44 within the inner cylindrical surface 28. As a result, the central axis A2 and the central axis A4 approximately coincide. In this state, as the automated guided vehicle 1 travels, the trolley 100 is towed while the outer cylindrical surface 463 of the cylindrical portion 46 contacts the inner cylindrical surface 28 of the receiving member 20 at any point. Loose fit means that the outer cylindrical surface 463 of the cylindrical portion 46 fits with the inner cylindrical surface 28 with a predetermined gap. Furthermore, as the lifting platform 12 descends from the state shown in Figure 5B, the inner cylindrical surface 28 separates from the cylindrical portion 46 of the case 44, and the connection is released.

[0025] Next, we will explain the process by which the receiving member 20 connects to the ball caster 40 when the central axis A2 is offset from the central axis A4. Figure 6A shows the receiving member 20 and the ball caster 40 when the automated guided vehicle 1 is stopped with the central axes A2 and A4 offset. From this state, as the receiving member 20 rises toward the ball caster 40, the ball 48 comes into contact with the conical surface 24.

[0026] Figure 6B shows the receiving member 20 and the ball caster 40 in a state where the ball 48 is in contact with the conical surface 24. As the receiving member 20 rises further, the trolley 100 moves so that the ball caster 40 faces the inner cylindrical surface 28 by the caster 130, and the ball 48 rotates so that it moves downwards on the conical surface 24. As the receiving member 20 rises further, the ball 48 moves so as to slide down into the inner cylindrical surface 28, and the receiving member 20 connects to the ball caster 40 as shown in Figure 5B.

[0027] Figure 7A shows the state in which the ball 48 is moving from the conical surface 24 into the inner cylindrical surface 28. Figure 7B is an enlarged view of the area around the inclined surface 26 in Figure 7A. As the ball 48 moves from the conical surface 24 into the inner cylindrical surface 28, as shown in Figure 7B, the ball 48 momentarily contacts the inclined surface 26 at a contact point P1, while the curved surface 462 of the cylindrical portion 46 of the case 44 also contacts the inclined surface 26 at a contact point P2.

[0028] Here, since the inclined surface 26 is curved from the conical surface 24 toward the inner cylindrical surface 28, the curved surface 462 can easily slide along the inclined surface 26. As a result, the curved surface 462 of the cylindrical part 46 of the case 44 slides along the inclined surface 26, guiding the ball 48 and the tip of the cylindrical part 46 toward the inner cylindrical surface 28. In this way, because the curved surface 462 moves by sliding along the curved inclined surface 26, the receiving member 20 connects to the ball caster 40 more smoothly. Therefore, even if the accuracy of the stopping position of the automated guided vehicle 1 relative to the trolley 100 or the installation position of the trolley 100 is low, as described above, if the tip of the ball 48 is on the vertical upper part of the conical surface 24, the receiving member 20 can be connected to the ball caster 40.

[0029] Figure 7B shows the boundary point B1 between the conical surface 24 and the inclined surface 26, and the boundary point B2 between the inclined surface 26 and the inner cylindrical surface 28. In Figure 7B, boundary point B1 and contact point P2 overlap, but it is sufficient that the curved surface 462 is in contact with the inclined surface 26 at boundary point B1, or between boundary point B1 and boundary point B2, while the ball 48 is in contact with the inclined surface 26.

[0030] Figure 8A is an explanatory diagram of the receiving member 20x of the comparative example. Figure 8A corresponds to Figure 7A. Figure 8B is an enlarged view of Figure 8A. Unlike the receiving member 20 of this embodiment, the receiving member 20x of the comparative example does not have a sloped surface 26. That is, there is a continuous angle difference of 90 degrees or more between the conical surface 24x and the inner cylindrical surface 28x of the receiving member 20x. For this reason, when the ball 48 falls off the conical surface 24x, there is a risk that the curved surface 462 of the cylindrical portion 46 will ride up onto the conical surface 24x, as shown in Figures 8A and 8B.

[0031] Therefore, depending on the frictional force between the curved surface 462 and the conical surface 24x, the receiving member 20x may rise while the curved surface 462 is riding on the conical surface 24x. Also, even when the curved surface 462 is sliding on the conical surface 24x, if the rising speed of the receiving member 20x is faster than the speed at which the curved surface 462 slides down the conical surface 24x, the curved surface 462 will ride on the conical surface 24x for a short time. As a result, the trolley 100 may be towed by the automated guided vehicle 1 while tilted. In addition, the curved surface 462 may slide off the conical surface 24x during towing, causing an impact to the trolley 100. Thus, the trolley 100 may be towed in an unstable state. As described above, in this embodiment, the receiving member 20 is smoothly connected to the ball caster 40 by the inclined surface 26, and the trolley 100 is towed in a stable state.

[0032] Next, the slope 26 will be described. Figure 9 is an enlarged view of the area around the slope 26. Figure 9 shows the center of curvature C of the slope 26, the radius of curvature R of the slope 26, the angular range θr in which the slope 26 is formed, and the inclination angle θt of the conical surface 24 with respect to the horizontal line. In this embodiment, the slope 26 is curved with a constant radius of curvature R.

[0033] Here, at boundary point B1, the inclined surface 26 is smoothly continuous from the conical surface 24, and at boundary point B2, the inclined surface 26 is continuous from the inner cylindrical surface 28 with a predetermined angle. In other words, the change in angle from the inclined surface 26 to the inner cylindrical surface 28 at boundary point B2 is greater than the change in angle from the conical surface 24 to the inclined surface 26 at boundary point B1. Furthermore, the change in angle from the conical surface 24 to the inclined surface 26 at boundary point B1 is a very small angle close to zero. To put it another way, the angle range θr is not the angle obtained by subtracting the inclination angle θt from 90 degrees, but is smaller than this angle.

[0034] For example, if we try to maintain the radius of curvature R while smoothly continuing the inclined surface 26 from the conical surface 24 at boundary point B2, the angular range θr will be 90 degrees minus the inclination angle θt. In this case, boundary point B2 will be located vertically lower than boundary point B2 shown in Figure 8, and the vertical length of the inner cylindrical surface 28 will be shortened. If the vertical length of the inner cylindrical surface 28 is short, the insertion depth of the cylindrical part 46 into the inner cylindrical surface 28 will be shortened when the receiving member 20 is connected to the ball caster 40, as shown in Figure 5B. This may make it impossible to stably tow the trolley 100.

[0035] In this embodiment, as described above, at boundary point B1, the inclined surface 26 is smoothly continuous from the conical surface 24, and at boundary point B2, the inclined surface 26 is continuous from the inner cylindrical surface 28 with a predetermined angle. This ensures that the length of the inner cylindrical surface 28 is maintained, and the trolley 100 is towed in a stable state.

[0036] Furthermore, as described above, the support portion 142 flexes when the receiving member 20 and the ball caster 40 are connected, and the flexing of the support portion 142 is released after the connection is complete. That is, after the connection is complete, the insertion depth of the cylindrical portion 46 into the inner cylindrical surface 28 is ensured. This also ensures that the trolley 100 is towed in a stable and secure state.

[0037] In the above embodiment, the inclined surface 26 is curved, but is not limited to this. The inclined surface 26 may be, for example, a flat surface with a constant inclination angle. In this case, the inclination angle of the inclined surface 26 corresponds to the inclination angle of the common tangent line passing through a point on the outer surface of the ball 48 and a point on the curved surface 462 of the case 44.

[0038] In the above embodiment, a ball caster 40 is attached to the trolley 100 and the automated guided vehicle 1 has a receiving member 20, but the embodiment is not limited to this. For example, the automated guided vehicle 1 may have a ball caster 40 and a receiving member 20 is attached to the trolley 100. In this case, the ball caster 40 is provided on the automated guided vehicle 1 so that the balls 48 of the ball caster 40 face vertically upward, and the receiving member 20 is attached to the trolley 100 so that the conical surface 24 of the receiving member 20 faces vertically downward. In this case, the receiving member 20 corresponds to the connected member, and the ball caster 40 corresponds to the connecting member.

[0039] It is sufficient that at least one of the receiving member 20 and one of the ball caster 40 is attached to the trolley 100, and at least one of the other of the receiving member 20 and ball caster 40 is provided on the automated guided vehicle 1. However, from the viewpoint of the stability of the towed trolley 100, it is desirable that multiple receiving members 20 are each connected to multiple ball casters 40. For this reason, it is preferable that multiple of the receiving member 20 and ball caster 40 are attached to the trolley 100, and that multiple of the other of the receiving member 20 and ball caster 40 are provided on the automated guided vehicle 1.

[0040] Although preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of Symbols]

[0041] 1. Automated Guided Vehicle (AGV) 12. Lifting platform (lifting component) 14. Support plate (elastic support member) 20 Receiving member (the other of the connected member and the connecting member, the connecting member) 24 Conical surfaces 26 Slopes 28 Inner cylindrical surface 40 Ball caster (connected member and one of the connecting members, connected member) 44 cases 46 Cylindrical section 461 Tip surface 462 Curved surface 463 Outer cylindrical surface 100 carts

Claims

1. An automated guided vehicle that tows objects equipped with casters, A vehicle that can be driven, A connecting member that can be connected to a connecting member attached to the object to be transported, The vehicle body is equipped with a lifting member that raises and lowers the connecting member toward the connected member to connect the connecting member to the connected member, One of the connected member and the connecting member is, The ball and, The system includes the connected member and a cylindrical case with a part of the ball exposed from the tip facing the other of the connecting member, The other party mentioned above is, A conical surface facing the aforementioned one, wherein the inner diameter decreases as it moves away from the aforementioned one, An inner cylindrical surface located opposite to the one in the conical surface when facing the one in the aforementioned state, having an inner diameter smaller than the minimum inner diameter of the conical surface, and capable of loosely fitting the ball and the tip of the case, It has a continuous slope extending from the conical surface to the inner cylindrical surface, The tip of the case is loosely fitted together with the ball within the inner cylindrical surface, thereby connecting the connected member to the connecting member. With the ball in contact with the inclined surface, the case can contact the inclined surface without contacting the conical surface. Automated guided vehicle.

2. The unmanned transport vehicle according to claim 1, wherein the inclined surface and the inner cylindrical surface are continuous via a predetermined angle.

3. The aforementioned slope is curved with a constant radius of curvature. The unmanned transport vehicle according to claim 2, wherein the conical surface and the inclined surface are smoothly continuous.

4. The aforementioned case is, The tip surface of the ball, from which a part of it protrudes, An outer cylindrical surface located opposite to the other side of the tip surface, facing the other side, and having an outer diameter that is larger than the outer diameter of the ball and smaller than the inner diameter of the inner cylindrical surface, It has a curved surface that is continuous from the tip surface to the outer cylindrical surface, An automated guided vehicle according to any one of claims 1 to 3, wherein, when the ball is in contact with the inclined surface, the case does not come into contact with the conical surface, but the curved surface is able to come into contact with the inclined surface.

5. An automated guided vehicle according to any one of claims 1 to 3, comprising an elastic support member attached to the lifting member and elastically supporting the connecting member toward the connected member.

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