Connection mechanism and conveyance device

Abstract

To facilitate backing of a conveyance device.SOLUTION: This connection mechanism is configured to connect a travel body that has a drive source and can move back and forth and a towed vehicle towed by the travel body. The connection mechanism comprises: a first connection member; and a second connection member. The first connection member is configured to be attached to one of the travel body and the towed vehicle. The second connection member is configured to be attached to the other of the travel body and the towed vehicle. The second connection member is connected to the first connection member so as to be movable back and forth. The second connection member is configured to be horizontally oscillatable with respect to the first connection member during moving forward. The second connection member is configured to be horizontally nonoscillatable with respect to the first connection member during moving back. The first connection member is disposed on a first side in the back-and-forth direction with respect to the second connection member.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a coupling mechanism and a conveying device.

Background Art

[0002] In recent years, in factories and the like, a conveying device that pulls a towed vehicle by a traveling body having a drive source has been put into practical use. The towed vehicle is connected to the traveling body so as to be rotatable. Therefore, the traveling body needs to travel in consideration of the traveling locus of the towed vehicle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conveying device as described above, there is a desire to move not only forward but also backward. However, it is very difficult to control the traveling body that pulls the towed vehicle to move backward.

[0005] An object of the present invention is to provide a coupling mechanism that can facilitate the backward movement of a conveying device.

Means for Solving the Problems

[0006] The coupling mechanism according to the first aspect is a coupling mechanism configured to couple a traveling body having a drive source and capable of moving forward and backward, and a towed vehicle towed by the traveling body. The coupling mechanism includes a first coupling member and a second coupling member. The first coupling member is configured to be attached to one of the traveling body and the towed vehicle. The second coupling member is configured to be attached to the other of the traveling body and the towed vehicle. The second coupling member is connected to the first coupling member so as to be movable in the front-rear direction. The second coupling member is configured to be swingable in the horizontal direction with respect to the first coupling member during forward movement. The second coupling member is configured to be non-swingable in the horizontal direction with respect to the first coupling member during backward movement. The first coupling member is disposed on the first side in the front-rear direction with respect to the second coupling member. Note that the first side in the front-rear direction means the front or the rear.

[0007] According to this configuration, the coupling mechanism can be turned during the forward movement of the traveling body, while it cannot be turned during the backward movement of the traveling body. Therefore, the traveling body and the towed vehicle can be moved backward integrally during backward movement. For this reason, the above-described coupling mechanism can facilitate the backward movement of the conveying device.

[0008] The coupling mechanism according to the second aspect is configured as follows in the coupling mechanism according to the first aspect. The first coupling member has an engaging convex portion. The engaging convex portion extends in the front-rear direction. The second coupling member has an engaging concave portion. The engaging concave portion faces the engaging convex portion and opens toward the engaging convex portion. The second coupling member becomes non-swingable in the horizontal direction with respect to the first coupling member when the engaging convex portion enters the engaging concave portion during backward movement. Further, the second coupling member becomes swingable in the horizontal direction with respect to the first coupling member when the engaging convex portion comes out of the engaging concave portion during forward movement.

[0009] The coupling mechanism according to the third aspect is configured as follows in the coupling mechanism according to the second aspect. The first coupling member has a seal member attached to the outer peripheral surface of the engaging convex portion. The seal member seals between the engaging convex portion and the engaging concave portion in a state where the engaging convex portion enters the engaging concave portion.

[0010] The coupling mechanism according to the fourth aspect is configured as follows in the coupling mechanism according to the second or third aspect. At least one of the first coupling member and the second coupling member has a communication hole that communicates the engaging recess and the outside of the engaging recess.

[0011] The coupling mechanism according to the fifth aspect is configured as follows in the coupling mechanism according to any one of the first to fourth aspects. The second coupling member has a housing space and an opening. The opening opens to the first side in the front-rear direction from the housing space. The first coupling member has a swing portion and an extending portion. The swing portion is housed in the housing space. The extending portion extends from the swing portion to the first side in the front-rear direction through the opening. The swing portion has a contact surface. The contact surface faces the first side in the front-rear direction. The contact surface is arc-shaped in plan view. The second coupling member has a swing inner wall surface. The swing inner wall surface is an inner wall surface that defines the housing space and faces the contact surface. The swing inner wall surface is shaped to follow the swing portion in plan view.

[0012] The coupling mechanism according to the sixth aspect is configured as follows in the coupling mechanism according to the fifth aspect. The swing portion is semi-cylindrical or cylindrical and extends in the vertical direction. The swing inner wall surface is shaped to follow the swing portion.

[0013] The coupling mechanism according to the seventh aspect is configured as follows in the coupling mechanism according to the fifth or sixth aspect. The swing portion is hemispherical or spherical. The swing inner wall surface is shaped to follow the swing portion.

[0014] The coupling mechanism according to the eighth aspect is configured as follows in the coupling mechanism according to any one of the first to seventh aspects. The second coupling member has a mounting portion and a housing portion. The mounting portion is mounted on the other of the traveling body and the towed vehicle. The housing portion is mounted on the first coupling member. The housing portion is mounted so as to be swingable in the vertical direction with respect to the mounting portion.

[0015] The coupling mechanism according to the ninth aspect is configured as follows in the coupling mechanism according to any one of the first to eighth aspects. The first coupling member has a mounting portion and an extending portion. The mounting portion is attached to one of the traveling body and the towed vehicle. The extending portion is rotatably attached to the mounting portion. The extending portion is cylindrical or tubular.

[0016] The conveying device according to the tenth aspect includes a traveling body, a towed vehicle, and a coupling mechanism according to any one of the first to ninth aspects. The traveling body has a drive source. The traveling body is configured to move forward and backward. The towed vehicle is configured to be towed by the traveling body. The coupling mechanism connects the traveling body and the towed vehicle.

[0017] The coupling mechanism according to the eleventh aspect is configured as follows in the conveying device according to the tenth aspect. The towed vehicle has a vehicle body, front wheels, and rear wheels. The front wheels are rotatably attached to the vehicle body. The rear wheels are non-rotatably attached to the vehicle body.

Advantages of the Invention

[0018] According to the present invention, the backward movement of the conveying device can be facilitated.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiment for Carrying Out the Invention

[0020] Hereinafter, the coupling mechanism and the transport device according to the present embodiment will be described with reference to the drawings. FIG. 1 is a side view of the transport device 100, and FIG. 2 is a plan view of the transport device 100. In FIG. 2, a cross-sectional view is shown for a part of the coupling mechanism 103 to facilitate illustration.

[0021] As shown in FIGS. 1 and 2, the transport device 100 includes a traveling body 101, a towed vehicle 102, and a coupling mechanism 103. The transport device 100 travels, for example, inside a factory, loads the towed vehicle 102 with goods, and transports them. The direction (left direction) indicated by the arrows in FIGS. 1 and 2 is the forward direction.

[0022] <Traveling body> The traveling body 101 has a drive source and is configured to be capable of autonomous travel. The traveling body 101 is a so-called AMR (Autonomous Mobile Robot). The traveling body 101 is configured to be capable of moving forward and backward. The traveling body 101 includes a vehicle body 101a, a pair of driven wheels 101b, a pair of drive wheels 101c, a pair of electric motors 101d (an example of a drive source), and the like.

[0023] The driven wheels 101b and the drive wheels 101c are attached to the bottom surface of the vehicle body 101a. In this embodiment, a pair of driven wheels 101b serve as the front wheels, and a pair of drive wheels 101c serve as the rear wheels. Note that a pair of driven wheels 101b may serve as the rear wheels, a pair of drive wheels 101c may serve as the front wheels, or all the wheels may be drive wheels 101c. The driven wheels 101b are attached to the vehicle body 101a so as to be rotatable. That is, the front wheels are rotatable. For example, the driven wheels 101b are swivel casters or ball casters, etc.

[0024] The electric motor 101d is configured to drive the drive wheels 101c. Note that when the electric motor 101d rotates forward, the traveling body moves forward, and when the electric motor 101d rotates in reverse, the traveling body 101 moves backward. One of the pair of electric motors 101d drives the right drive wheel 101c, and the other electric motor 101d drives the left drive wheel 101c.

[0025] <Trailer> The trailer 102 is configured to be towed by the traveling body 101. The trailer 102 is disposed behind the traveling body 101. The trailer 102 is connected to the traveling body 101 via a coupling mechanism 103. The trailer 102 has a vehicle body 102a, a pair of front wheels 102b, and a pair of rear wheels 102c.

[0026] The trailer 102 is configured to be able to load goods on the vehicle body 102a. The front wheels 102b and the rear wheels 102c are attached to the bottom surface of the vehicle body 102a. The front wheels 102b are attached to the vehicle body 102a so as to be rotatable. For example, the front wheels 102b are swivel casters or ball casters, etc. The rear wheels 102c are attached to the vehicle body 102a in a non-rotatable manner. For example, the rear wheels 102c are fixed casters, etc.

[0027] <Coupling mechanism> The coupling mechanism 103 is configured to couple the traveling body 101 and the towed vehicle 102. The coupling mechanism 103 has a first coupling member 3 and a second coupling member 4. The first coupling member 3 is attached to the traveling body 101. The second coupling member 4 is attached to the towed vehicle 102. The first coupling member 3 is arranged in front (an example of the first side in the front-rear direction) of the second coupling member 4 in the front-rear direction. Note that a part of the first coupling member 3 is arranged overlapping with a part of the second coupling member 4 in the front-rear direction.

[0028] The second coupling member 4 is connected to the first coupling member 3 so as to be movable in the front-rear direction. The second coupling member 4 can swing horizontally with respect to the first coupling member 3 when the traveling body 101 moves forward. Also, the second coupling member 4 cannot swing horizontally with respect to the first coupling member 3 when the traveling body 101 moves backward. Hereinafter, the coupling mechanism 103 will be described in detail.

[0029] <The first coupling member> FIG. 3 is a plan view of the coupling mechanism 103, and FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3. As shown in FIGS. 3 and 4, the first coupling member 3 has a first attachment portion 31, an extending portion 32, a swinging portion 33, an engaging convex portion 34, and a seal member 35.

[0030] The first attachment portion 31 is a portion attached to the traveling body 101. The first attachment portion 31 is fixed to the traveling body 101 by, for example, bolts or the like. The first attachment portion 31 moves integrally with the traveling body 101. The first attachment portion 31 is non-swingable with respect to the traveling body 101.

[0031] The extending portion 32 extends from the first attachment portion 31 toward the second coupling member 4 in the front-rear direction. Specifically, the extending portion 32 extends rearward (an example of the second side in the front-rear direction) from the first attachment portion 31.

[0032] The extending portion 32 extends to the swinging portion 33 through the opening 422 of the second connecting member 4 described later. That is, the extending portion 32 extends forward (an example of the first side in the front-rear direction) from the swinging portion 33. Specifically, the extending portion 32 extends forward (an example of the first side in the front-rear direction) from the swinging portion 33 through the opening 422.

[0033] The extending portion 32 is cylindrical. Note that the extending portion 32 may be cylindrical. The extending portion 32 is attached to the first attachment portion 31. The extending portion 32 is rotatably attached to the first attachment portion 31. That is, the extending portion 32 is rotatable about the central axis of the extending portion 32 with respect to the first attachment portion 31. Thereby, when the traveling body 101 and the towed vehicle 102 are in a twisted state, the twist can be absorbed. The extending portion 32 is immovable in the front-rear direction with respect to the first attachment portion 31. Also, the extending portion 32 is non-swingable with respect to the first attachment portion 31.

[0034] The swinging portion 33 is housed in the housing space 421 of the second connecting member 4 described later. FIG. 5 is a perspective view showing the extending portion 32, the swinging portion 33, and the engaging convex portion 34 of the first connecting member 3. As shown in FIG. 5, the swinging portion 33 is semi-cylindrical and extends in the vertical direction. Note that the semi-cylindrical shape means a shape obtained by generally halving a cylinder, and it is not necessary to be exactly half. Also, the swinging portion 33 may be cylindrical and extend in the vertical direction.

[0035] As shown in FIGS. 3 to 5, the swinging portion 33 has a contact surface 331. The contact surface 331 is arcuate in plan view. The contact surface 331 faces forward (an example of the first side in the front-rear direction). The contact surface 331 contacts the swinging inner wall surface 425 of the second connecting member 4 described later when the traveling body 101 moves forward. Note that the contact surface 331 is separated from the swinging inner wall surface 425 of the second connecting member 4 and is not in contact therewith when the traveling body 101 moves backward. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 4. As shown in FIG. 6, a part of the contact surface 331 is exposed from the opening 422.

[0036] As shown in FIGS. 3 to 5, the engaging convex portion 34 extends in the front-rear direction. Specifically, the engaging convex portion 34 extends rearward (an example of the second side in the front-rear direction) from the swinging portion 33. The engaging convex portion 34 is cylindrical. Note that the engaging convex portion 34 may be prismatic. The engaging convex portion 34 is housed in the housing space 421 when the traveling body 101 moves forward.

[0037] The seal member 35 is attached to the outer peripheral surface of the engaging convex portion 34. The seal member 35 is, for example, an O-ring. The engaging convex portion 34 has a groove portion extending in the circumferential direction at the rear end portion, and the seal member 35 is disposed in the groove portion. The seal member 35 is configured to seal between the engaging convex portion 34 and the engaging concave portion 423 when the engaging convex portion 34 enters the engaging concave portion 423 described later.

[0038] <Second connecting member> The second connecting member 4 has a second attachment portion 41 and a housing portion 42. The second attachment portion 41 is attached to the towed vehicle 102. The second attachment portion 41 is attached to, for example, a plurality of attachment pins 102d extending upward formed on the vehicle body 102a of the towed vehicle 102. The second attachment portion 41 is movable in the vertical direction with respect to the attachment pin 102d. Note that the second attachment portion 41 may be immovable in the vertical direction with respect to the attachment pin 102d. The second attachment portion 41 is non-swingable with respect to the towed vehicle 102.

[0039] The housing portion 42 is disposed forward (an example of the first side in the front-rear direction) with respect to the second attachment portion 41. The housing portion 42 is attached to the second attachment portion 41 so as to be swingable in the vertical direction. Specifically, the housing portion 42 is swingably attached to the second attachment portion 41 via a pin 43. The housing portion 42 is swingable about the pin 43.

[0040] The accommodating portion 42 has a protruding portion 426 at the lower part. The protruding portion 426 is movable in the vertical direction. The protruding portion 426 is biased downward by a biasing member 427. The protruding portion 426 is engaged in a groove portion 101e formed in the traveling body 101. The groove portion 101e extends in the front-rear direction. When the second connecting member 4 moves in the front-rear direction with respect to the first connecting member 3, the protruding portion 426 moves in the front-rear direction along the groove portion 101e. When the second connecting member 4 swings in the horizontal direction with respect to the first connecting member 3, the protruding portion 426 moves left and right over the groove portion 101e.

[0041] The accommodating portion 42 is attached to the first connecting member 3. The accommodating portion 42 has an accommodating space 421, an opening portion 422, an engaging concave portion 423, and a communication hole 424. The accommodating space 421 accommodates the swinging portion 33 of the first connecting member 3.

[0042] The accommodating portion 42 has a swinging inner wall surface 425. The swinging inner wall surface 425 is a surface that faces the contact surface 331 of the swinging portion 33 among the inner wall surfaces that define the accommodating space 421. The swinging inner wall surface 425 faces rearward (an example of the second side in the front-rear direction). The swinging inner wall surface 425 has a shape that follows the contact surface 331 of the swinging portion 33 in plan view. The swinging inner wall surface 425 is arc-shaped in plan view.

[0043] The opening portion 422 opens forward (an example of the first side in the front-rear direction) from the accommodating space 421. As shown in FIG. 6, the opening portion 422 extends in the left-right direction. Through this opening portion 422, the extending portion 32 extends in the front-rear direction. The extending portion 32 is swingable in the left-right direction within the opening portion 422, while it is not swingable in the vertical direction.

[0044] The engaging concave portion 423 opens forward (an example of the first side in the front-rear direction). The engaging concave portion 423 communicates with the accommodating space 421. In a front-rear direction view, the area of the engaging concave portion 423 is smaller than the area of the accommodating space 421.

[0045] The engaging concave portion 423 faces the engaging convex portion 34 in the front-rear direction. That is, the engaging concave portion 423 opens toward the engaging convex portion 34. The engaging concave portion 423 is formed to have a size such that the engaging convex portion 34 can be accommodated. The engaging concave portion 423 is cylindrical. Preferably, the engaging convex portion 34 and the engaging concave portion 423 are configured such that when the engaging convex portion 34 enters or exits the engaging concave portion 423, the outer peripheral surface of the engaging convex portion 34 slides on the inner peripheral surface of the engaging concave portion 423.

[0046] The communication hole 424 communicates the engaging concave portion 423 with the outside of the engaging concave portion 423. That is, the communication hole 424 penetrates the accommodating portion 42 from the engaging concave portion 423 and communicates with the atmosphere outside the accommodating portion 42.

[0047] <Operation> According to the connecting mechanism 103 configured as described above, when the traveling body 101 moves forward, the first connecting member 3 moves in a direction away from the second connecting member 4, and the engaging convex portion 34 comes out of the engaging concave portion 423. Therefore, the first connecting member 3 can swing horizontally with respect to the second connecting member 4. As a result, as shown in FIG. 7, the towed vehicle 102 can swing horizontally with respect to the traveling body 101.

[0048] When the second connecting member 4 swings horizontally with respect to the first connecting member 3, the contact surface 331 of the swinging portion 33 slides on the swinging inner wall surface 425 of the accommodating portion 42. Therefore, the second connecting member 4 can swing smoothly with respect to the first connecting member 3. Further, since the extending portion 32 extends through the opening portion 422, the swinging range of the second connecting member 4 can be restricted. That is, since the extending portion 32 abuts against the end portion of the opening portion 422, the second connecting member 4 can be prevented from swinging further.

[0049] As shown in FIG. 8, when the traveling body 101 travels on a slope or a road surface with unevenness, etc., the second connecting member 4 can swing in the vertical direction, so that the conveying device 100 can travel smoothly. Specifically, the accommodating portion 42 of the second connecting member 4 swings in the vertical direction about the pin 43 with respect to the second mounting portion 41.

[0050] Next, when the traveling body 101 moves backward, as shown in FIG. 9, the first connecting member 3 moves so as to approach the second connecting member 4, and the engaging convex portion 34 enters the engaging concave portion 423. At this time, since the sealing member 35 is provided on the outer peripheral surface of the engaging convex portion 34, it is possible to suppress the impact when the first connecting member 3 collides with the second connecting member 4 when the engaging convex portion 34 enters the engaging concave portion 423. Note that the swinging portion 33 may collide with the inner wall surface defining the accommodation space 421, or the engaging convex portion 34 may collide with the bottom surface of the engaging concave portion 423.

[0051] When the engaging convex portion 34 enters the engaging concave portion 423, the second connecting member 4 becomes unable to swing in the horizontal direction with respect to the first connecting member 3. That is, the first connecting member 3 comes to move integrally with the second connecting member 4. As a result, the towed vehicle 102 becomes unable to swing with respect to the traveling body 101, and the traveling body 101 and the towed vehicle 102 move backward integrally, so that the backward movement of the conveying device 100 can be easily performed.

[0052] [Modification Example] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to these, and various modifications are possible without departing from the spirit of the present invention. Note that the following modification examples can basically be applied simultaneously.

[0053] (a) In the above embodiment, the swinging portion 33 has a semi-cylindrical shape, but the shape of the swinging portion 33 is not limited to this. FIG. 10 is a plan view of the connecting mechanism 103, FIG. 11 is a sectional view taken along line XI-XI of FIG. 10, and FIG. 12 is a perspective view showing the extending portion 32, the swinging portion 33, and the engaging convex portion 34.

[0054] As shown in FIGS. 10 to 12, the swinging portion 33 may be hemispherical. Note that the hemispherical shape means a shape obtained by generally dividing a sphere into two halves, and it is not necessary to be exactly half. Further, the swinging portion 33 may be spherical.

[0055] In this case, the swinging inner wall surface 425 also has a shape that follows the shape of the swinging portion 33. That is, the swinging inner wall surface 425 is hemispherical. The accommodating portion 42 is integrally formed with the second attachment portion 41. Note that the accommodating portion 42 may be swingably attached to the second attachment portion 41 via the pin 43, similarly to the above-described embodiment.

[0056] FIG. 13 is a cross-sectional view taken along line XIII-XIII of FIG. 10. As shown in FIG. 13, the opening 422 is circular in the axial direction view. For this reason, the second connecting member 4 can swing not only in the horizontal direction but also in the vertical direction with respect to the first connecting member 3.

[0057] (b) In the above-described embodiment, the first connecting member 3 is attached to the traveling body 101, and the second connecting member 4 is attached to the towed vehicle 102. However, the configuration of the coupling mechanism 103 is not limited to this. For example, the first connecting member 3 may be attached to the towed vehicle 102, and the second connecting member 4 may be attached to the traveling body 101. In this case, the front means the second side in the front-rear direction, and the rear means the first side in the front-rear direction. For example, the swinging inner wall surface 425 faces forward. Also, the contact surface 331 faces rearward. Further, the extending portion 32 extends rearward from the swinging portion 33.

[0058] (c) In the above-described embodiment, the communication hole 424 is formed in the accommodating portion 42. However, the configuration of the communication hole 424 is not limited to this. For example, the communication hole 424 may be formed in the engaging convex portion 34.

Explanation of Reference Numerals

[0059] 3: First connecting member 31: First attachment portion 32: Extending portion 33: Swinging portion 331: Contact surface 34: Engaging convex portion 35: Sealing member 4: Second connecting member 41: Second attachment portion 42: Accommodating portion 421: Accommodating space 422: Opening 423: Engagement recess 424: Communication hole 425: Oscillation inner wall surface 100: Conveyor 101: Traveling body 101a: Vehicle body 101d: Electric motor 102: Towed vehicle 102a: Vehicle body 102b: Front wheel 102c: Rear wheel 103: Coupling mechanism

Claims

1. A coupling mechanism configured to couple a traveling body having a drive source and capable of moving forward and backward, and a towed vehicle towed by the traveling body, A first connecting member configured to be attached to one of the traveling body and the towed vehicle; a second connecting member that is configured to be attached to the other of the traveling body and the towed vehicle, that is connected to the first connecting member so as to be movable in the front-rear direction, that is configured to be swingable in the horizontal direction relative to the first connecting member when moving forward, and that is configured not to be swingable in the horizontal direction relative to the first connecting member when moving backward; Equipped with The first connecting member is disposed on a first side in a front-rear direction with respect to the second connecting member. Connection mechanism.

2. The first connecting member has an engaging protrusion extending in the front-rear direction, the second connecting member has an engaging recess facing the engaging protrusion and opening toward the engaging protrusion, When moving backward, the engaging protrusion enters the engaging recess, thereby preventing the second connecting member from swinging horizontally relative to the first connecting member, and when moving forward, the engaging protrusion comes out of the engaging recess, thereby allowing the second connecting member to swing horizontally relative to the first connecting member. The coupling mechanism of claim 1 .

3. the first connecting member has a seal member attached to an outer circumferential surface of the engaging protrusion, The seal member seals between the engagement protrusion and the engagement recess when the engagement protrusion is inserted into the engagement recess. The coupling mechanism of claim 2.

4. At least one of the first connecting member and the second connecting member has a communication hole that communicates between the engagement recess and an outside of the engagement recess. The coupling mechanism of claim 2.

5. The second connecting member has an accommodation space and an opening that opens from the accommodation space to a first side in a front-rear direction, The first connecting member has a swinging portion accommodated in the accommodation space and an extending portion extending from the swinging portion through the opening to a first side in a front-rear direction, The swinging portion has a contact surface that faces a first side in the front-rear direction and is arc-shaped in a plan view, The second connecting member has an inner wall surface that defines the accommodation space and that faces the abutment surface, The swing inner wall surface has a shape that conforms to the swing portion in a plan view. The coupling mechanism of claim 1 .

6. The swinging portion is semi-cylindrical or cylindrical extending in the vertical direction, The swing inner wall surface is shaped to fit along the swing portion. The coupling mechanism of claim 5.

7. The oscillating portion is semispherical or spherical, The swing inner wall surface is shaped to fit along the swing portion. The coupling mechanism of claim 5.

8. The second connecting member has an attachment portion attached to the other of the traveling body and the towed vehicle, and a storage portion attached to the first connecting member, The storage portion is attached to the attachment portion so as to be swingable in the up and down direction. The coupling mechanism of claim 1 .

9. The first connecting member has an attachment portion attached to one of the traveling body and the towed vehicle, and a columnar or cylindrical extension portion rotatably attached to the attachment portion. The coupling mechanism of claim 1 .

10. A traveling body having a drive source and configured to move forward and backward; A towed vehicle configured to be towed by the traveling body; A coupling mechanism according to any one of claims 1 to 9, which couples the traveling body and the towed vehicle; A conveying device comprising:

11. The towed vehicle has a vehicle body, front wheels rotatably attached to the vehicle body, and rear wheels non-rotatably attached to the vehicle body. The conveying device according to claim 10.

Images