Trolley unit and method for assembling trolley unit

Abstract

A trolley unit (100) is provided with a traveling trolley (1) capable of traveling automatically and a traction trolley (2) towed by the traveling trolley (1). The traveling trolley (1) has a first placement table (10) on which goods can be placed, the traction trolley (2) has a second placement table (20) on which goods can be placed, and the second placement table (20) is disposed so as to cover the first placement table (10) from above. The traveling trolley (1) and the traction trolley (2) are connected by fitting a convex part (32) provided on one of the upper surface of the first mounting table (10) and the lower surface of the second mounting table (20) with a concave part (36) provided on the other one of the upper surface of the first mounting table (10) and the lower surface of the second mounting table (20).

Description

Technical Field

[0001] This invention relates to a trolley unit and a method for assembling the trolley unit. Background Technology

[0002] Technology for towing trolleys using a transport vehicle is known. For example, there is a technology for transporting a trolley with shelves using a transport vehicle equipped with a towing clamp. The towing clamp guides the left and right sides of the trolley through a pair of upwardly projecting support parts, presses the front of the trolley through multiple forward-facing pressing parts, and presses the rear of the trolley through movable stops, thereby connecting the transport vehicle to the trolley.

[0003] Previous technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2023-14790 Summary of the Invention

[0004] The technical problem to be solved by the invention In the aforementioned connection technology, the transport vehicle and the trolley are connected by components arranged in the front, rear, left, and right directions to surround and support the trolley, thus limiting the size of the trolleys that can be connected. Therefore, from the viewpoint that it is less restricted by the size of the trolley, the above technology is still insufficient.

[0005] One exemplary objective of one embodiment of the present invention is to provide a trolley unit that is not easily limited by the size of the traction trolley.

[0006] means for solving technical problems One embodiment of the present invention provides a trolley unit comprising a self-propelled traveling trolley and a traction trolley towed by the traveling trolley. The traveling trolley has a first loading platform capable of carrying goods. The traction trolley has a second loading platform capable of carrying goods. The second loading platform is configured to cover the first loading platform from above. The traveling trolley and the traction trolley are connected by engaging a protrusion on the upper surface of the first loading platform and a recess on the lower surface of the second loading platform with the protrusion on the other.

[0007] Another embodiment of the present invention is a method for assembling a trolley unit. This method assembles a trolley unit comprising a traveling trolley having a first loading platform capable of carrying goods and capable of self-movement, and a traction trolley having a second loading platform capable of carrying goods and towed by the traveling trolley. The traction trolley has guardrail members facing the four sides of the traveling trolley. A protrusion is provided on one of the upper surface of the first loading platform and a recess on the other. The assembly method includes the following steps: covering the traction trolley from above the traveling trolley; positioning the second loading platform above the first loading platform; configuring the guardrail members to surround the four sides of the traveling trolley; and connecting the traction trolley to the traveling trolley by engaging the protrusions and recesses.

[0008] Furthermore, any combination of the above-mentioned constituent elements, or a solution obtained by substituting the constituent elements or descriptions of the present invention among methods, systems, etc., is also effective as an embodiment of the present invention.

[0009] Invention Effects According to the present invention, a trolley unit that is not easily limited by the size of the traction trolley can be provided. Attached Figure Description

[0010] Figure 1 This is a perspective view showing an example of the trolley unit involved in the implementation method.

[0011] Figure 2 It is a display Figure 1 A side sectional view of the connecting mechanism of the trolley unit.

[0012] Figure 3 It is a display Figure 1 A top view of the guardrail components of the traction trolley.

[0013] Figure 4 It is a display Figure 1 A 3D view of the traveling trolley.

[0014] Figure 5 It is a display Figure 1 A diagram showing the wheel configuration of the traveling trolley.

[0015] Figure 6 It is a general overview Figure 1 A block diagram illustrating the composition of the trolley unit.

[0016] Figure 7 It is a side sectional view showing a modified example with a forward and backward mechanism. Detailed Implementation

[0017] Hereinafter, the present invention will be described with reference to the accompanying drawings, based on exemplary embodiments. In the embodiments and modifications, the same or equivalent constituent elements and components are labeled with the same symbols, and repeated descriptions are omitted where appropriate. Furthermore, for ease of understanding, the dimensions of components are appropriately enlarged or reduced in the accompanying drawings. Also, in the accompanying drawings, some components that are not important to the description of the embodiments are omitted.

[0018] Furthermore, terms including ordinal numbers such as 1 and 2 are used to describe various constituent elements, but such terms are only used for the purpose of distinguishing one constituent element from other constituent elements, and the constituent elements are not limited by such terms.

[0019] [Implementation Method] The structure of the trolley unit 100 according to the embodiment will be described with reference to the accompanying drawings. Figure 1 This is a perspective view showing an example of the trolley unit 100. For example... Figure 1 As indicated by the arrows, the straight direction of the trolley unit 100 is called "front" or "forward", and its opposite direction is called "rear" or "rear". The right direction of the straight direction is called "right" or "right side", and its opposite direction is called "left" or "left side".

[0020] The trolley unit 100 is a trolley unit comprising a self-propelled traveling trolley 1 and a traction trolley 2 towed by the traveling trolley 1. The traveling trolley 1 has a first loading platform 10 capable of carrying goods, and the traction trolley 2 has a second loading platform 20 capable of carrying goods. The trolley unit 100 is a trolley unit capable of loading an object (not shown) onto the second loading platform 20 and transporting it to its destination.

[0021] exist Figure 1 In the diagram, the traction trolley 2 in its separated state before connection is represented by a solid line, and the outline of the traction trolley 2 after connection is represented by a dashed line. The traveling trolley 1 of the embodiment also functions as an unmanned transport vehicle capable of independently placing the load (not shown) on the first loading platform 10 and transporting it to its destination.

[0022] The traction trolley 2 of the embodiment mainly includes a second platform 20, four outriggers 21, four wheels 22, four guardrail components 58, and a second connecting component 34. The second connecting component 34 will be described later.

[0023] In one embodiment, the second mounting platform 20 is, for example, a mounting platform made of tubular material such as prisms, which is quadrilateral when viewed from above. The second mounting platform 20 includes: tubular material assembled on the outer periphery of the four sides, and multiple tubular materials arranged in a grid pattern between the tubular materials on the two sides that are separated at the front and back.

[0024] The outriggers 21 are constructed of tubular material, such as cylinders, and extend downwards from the four corners of the second platform 20. The four corners of the second platform 20 are fixed to and supported by the outriggers 21. The wheels 22 are driven wheels fixed to the lower ends of the outriggers 21, used to smoothly support the horizontal movement of the traction trolley 2. The wheels 22 can be, for example, swivel casters capable of steering. In this case, the traction trolley 2 can move smoothly along the travel direction of the traveling trolley 1.

[0025] The second platform 20 is configured to cover the first platform 10 from above. At this time, the traveling trolley 1 and the traction trolley 2 are connected by a connecting mechanism 30. The connecting mechanism 30 has a protrusion 32 provided on one of the upper surface of the first platform 10 and the lower surface of the second platform 20, and a recess 36 provided on the other. The traveling trolley 1 and the traction trolley 2 are connected by engaging the protrusion 32 and the recess 36. In this embodiment, the protrusion 32 is provided on the lower surface of the second platform 20, and the recess 36 is provided on the upper surface of the first platform 10.

[0026] In the connected state, the wheels 14 of the traveling trolley 1 and the wheels 22 of the traction trolley 2 are in contact with the ground (not shown), and the second platform 20 is located above and separated from the first platform 10. At this time, most of the weight of the goods placed on the second platform 20 is transferred to the wheels 22 of the traction trolley 2, and the connecting mechanism 30 and the traction trolley 2 are configured such that the first platform 10 bears almost no weight of the second platform 20. Alternatively, the connecting mechanism 30 and the traction trolley 2 can be configured such that a portion of the weight of the goods placed on the second platform 20 is transferred to the wheels 14 of the traveling trolley 1 via the first platform 10.

[0027] Figure 2 This is a side sectional view of the connecting mechanism 30 of the trolley unit 100. The connecting mechanism 30 is a mechanism for connecting the traveling trolley 1 and the traction trolley 2, and has a first connecting member 38, a recess 36, a second connecting member 34, and a rod-shaped member 33. Figure 2 (A) shows the case where the protrusion 32 is provided on the lower surface of the second mounting platform 20 and the recess 36 is provided on the upper surface of the first mounting platform 10. Figure 2 (B) shows the case where the recess 36 is provided on the lower surface of the second mounting platform 20 and the protrusion 32 is provided on the upper surface of the first mounting platform 10. Hereinafter, Figure 2 The structure shown in (A) will be used as an example for explanation.

[0028] The traveling trolley 1 has one or more first connecting members 38 detachably mounted to the upper surface of the first platform 10, and the first connecting member 38 has a recess 36. In this example, the recess 36 is a blind hole. The traction trolley 2 has one or more second connecting members 34 detachably mounted to the lower surface of the second platform 20, and the second connecting member 34 has a protrusion 32. The one or more recesses 36 are provided in the same number at positions corresponding to the one or more protrusions 32.

[0029] The shapes of the first connecting member 38 and the second connecting member 34 are not particularly limited. In the embodiments, such as Figure 1 As shown, the first connecting member 38 is a rectangular strip-shaped member extending horizontally in the length direction when viewed from above. In the embodiment, as... Figure 1 As shown, the second connecting member 34 is a rectangular strip-shaped member extending left and right in the length direction when viewed from above. In the embodiment, the first connecting member 38 and the second connecting member 34 are provided at two positions that clamp the steering center CL of the traveling carriage 1. That is, the recess 36 and the protrusion 32 are provided at two positions that clamp the steering center CL of the traveling carriage 1. At this time, the rotation of the traction carriage 2 relative to the traveling carriage 1 can be restricted. When three or more recesses 36 and protrusions 32 are provided, the recesses 36 and protrusions 32 can be arranged around the steering center CL. From the viewpoint of equally distributing the connection load, it is preferable that the multiple recesses 36 and protrusions 32 are respectively arranged at positions equidistant from the steering center CL.

[0030] The method of fixing the first connecting member 38 is not particularly limited. In one embodiment, the first connecting member 38 is fixed to a threaded hole 37 provided on the upper surface of the first mounting platform 10 using bolts B1. Bolt B1 is screwed into the threaded hole 37 through a through hole 39 formed in the first connecting member 38. In one embodiment, the first connecting member 38 is fixed by bolts B1 at two locations where the recess 36 is sandwiched, but it can also be fixed by bolts at three or more locations. The method of fixing the second connecting member 34 is not particularly limited, but in one embodiment, it is fixed to a threaded hole (not shown) provided on the lower surface of the second mounting platform 20 using bolts B2. Bolt B2 is screwed into the threaded hole through a through hole 342 formed in the second connecting member 34. In one embodiment, the second connecting member 34 is fixed by bolts B2 at two locations where the protrusion 32 is sandwiched, but it can also be fixed by bolts at three or more locations.

[0031] The threaded hole 37 may be specifically provided for fixing the first connecting member 38, but in this embodiment, it can also be used for fixing other types of auxiliary device components (not shown). That is, a general-purpose unmanned transport vehicle can be used as the traveling trolley 1. In this case, it is advantageous to reduce design time and manufacturing time compared to the case where a dedicated threaded hole is provided.

[0032] The first mounting platform 10 has threaded holes 37 pre-installed for mounting at least two auxiliary device components. The first connecting member 38 can also be one of the auxiliary device components of the first mounting platform 10. Examples of auxiliary device components, besides the first connecting member 38, include guide components for goods placed on the first mounting platform 10 or hooks for securing ropes to goods. In this embodiment, eight threaded holes 37 are provided in the first mounting platform 10, and the first connecting member 38 utilizes two of these eight threaded holes 37. The number of threaded holes 37 is not particularly limited.

[0033] like Figure 2 As shown, the protrusion 32 protrudes downward from the second connecting member 34. The second connecting member 34 and the protrusion 32 are separately formed and then assembled together. The protrusion 32 is the end portion of a rod-shaped member 33 that passes through the through hole 35 provided in the second connecting member 34. A flange portion 31 larger than the through hole 35 is provided on the base end side of the rod-shaped member 33. The flange portion 31 restricts the vertical position of the protrusion 32. The rod-shaped member 33 has a hollow portion 334 that opens upward. The rod-shaped member 33 is fixed to the second connecting member 34 by pressing, bonding, welding, etc. Furthermore, the end of the protrusion 32 is conical, making it easy to insert into the recess 36.

[0034] If the protrusion 32 experiences a significant positional shift during normal use, the connection state of the connecting mechanism 30 will become unstable, potentially leading to disconnection. Therefore, in this embodiment, the protrusion 32 is positioned on the second mounting platform 20 in a manner that prevents displacement. "Prevents displacement" means that even if a force is applied to the protrusion 32 without the use of tools, the protrusion 32 will not shift. Specifically, the rod-shaped member 33 with the protrusion 32 is fixed to the second connecting member 34, which is bolted to the second mounting platform 20. Therefore, during normal use, the protrusion 32 is firmly supported by the second mounting platform 20 and will not shift. Furthermore, when the protrusion is positioned on the first mounting platform, the protrusion is positioned on the first mounting platform in a manner that prevents displacement. And, in Figure 2 In the case shown in (B), the rod-shaped member 33 may also be fixed to the upper surface of the first connecting member 38 without penetrating through it.

[0035] Reference Figure 1 , Figure 3 The fence component 58 of the traction trolley 2 will be described. Figure 3This is a top view showing the guardrail components 58 of the traction trolley 2. If the connecting mechanism 30 accidentally disengages, it is possible that only the traveling trolley 1 will move while the traction trolley 2 will fall. In this case, it is necessary to stop the movement of all trolleys in that area and have workers perform restoration work to reconnect them, during which time the transport operation is interrupted. Therefore, in this embodiment, the traction trolley 2 has guardrail components 58 respectively facing the four sides of the traveling trolley 1. At this time, even if the connection of the connecting mechanism 30 is accidentally disengaged, traction can continue by pushing the guardrail components 58 by the traveling trolley 1.

[0036] In one embodiment, the fence component 58 is constructed, for example, of a generally horizontally extending cylindrical tube and is mounted between two adjacent support legs 21. Both ends of the fence component 58 are fixed to the support legs 21. Figure 3 As shown, the fence components 58 are arranged in a quadrilateral shape to surround the traction trolley 2 when viewed from above. The fence components 58 are positioned at a blind corner that will not become a blind corner for the sensors mounted on the traveling trolley 1, which will be described later.

[0037] Reference Figure 4 , Figure 5 , Figure 6 The description of the traveling trolley 1 is as follows. Figure 4 This is a 3D view showing the traveling trolley 1. Figure 5 This is a diagram showing the wheel configuration of the traveling trolley 1. Figure 6 This is a block diagram that roughly shows the structure of the trolley unit 100.

[0038] As an example, the traveling vehicle 1 can be an Autonomous Mobile Robot (AMR) that moves autonomously to its destination. The traveling vehicle 1 in this embodiment can generate a route from its origin to its destination and autonomously travel along that route. The autonomous travel of the traveling vehicle 1 can be achieved using autonomous driving techniques based on well-known principles. As an example, the traveling vehicle 1 in this embodiment uses a control technique called SLAM (Simultaneous Localization and Mapping) for autonomous driving.

[0039] SLAM is a well-known technology, therefore its detailed description is omitted. SLAM can simultaneously perform the self-positioning function and map creation function of the traveling carriage 1. The map creation function is the function of acquiring surrounding information through camera components or equipped sensors, and creating a surrounding map, i.e., map information, based on this surrounding information. The self-positioning function is the function of comparing the map information with pre-stored data of location-related information, and determining its own position and orientation on the map if the stored data matches the map information. The traveling carriage 1 can calculate the distance between itself and surrounding obstacles or road signs through SLAM, and control its movement to avoid obstacles based on the calculation results.

[0040] The traveling vehicle 1 of this embodiment includes a body 12, multiple wheels 14A-14D, a wheel drive unit 16, an operation unit 17, a battery (not shown), a first mounting platform 10, an object detection sensor 11, an obstacle sensor 19, an image sensor 18, and an information processing unit 40. When referring collectively to the object detection sensor 11, the obstacle sensor 19, and the image sensor 18, they are collectively referred to as mounted sensors. The body 12 functions as a shell enclosing the internal components.

[0041] The operation unit 17 accepts input information based on user operation and provides the input information to the information processing unit 40. The operation unit 17 accepts input of information related to the user's driving, such as the destination, and provides the result to the information processing unit 40.

[0042] like Figure 4 As shown, multiple wheels 14A to 14D are mounted inside the body 12 such that a portion of the wheel protrudes downwards from the body 12. The structure of the multiple wheels 14A to 14D is not limited, but in some embodiments, such as... Figure 5 As shown, the system includes two first wheels 14A, two second wheels 14B, two third wheels 14C, and two fourth wheels 14D. The two first wheels 14A are drive wheels driven by the wheel drive unit 16, and are arranged spaced apart horizontally near the center in the front-rear direction. The two second wheels 14B are driven wheels, arranged further forward than the first wheels 14A and spaced apart horizontally. The two third wheels 14C are driven wheels, arranged further forward than the second wheels 14B and spaced apart horizontally. The two fourth wheels 14D are driven wheels, arranged further rearward than the first wheels 14A and spaced apart horizontally.

[0043] The wheel drive unit 16, under the control of the information processing unit 40, rotates and drives the two first wheels 14A. In this embodiment, the wheel drive unit 16 includes two gear motors (not shown) corresponding to the two first wheels 14A respectively. Instead of gear motors, the wheel drive unit 16 may include known drive devices such as motors or engines. The traveling carriage 1 moves forward or backward by rotating and driving the two first wheels 14A at the same speed, and turns right or left around the steering center CL by creating a speed difference between the two first wheels 14A.

[0044] The battery supplies power to the wheel drive unit 16, object detection sensor 11, obstacle sensor 19, image sensor 18, and information processing unit 40. The battery in this embodiment is a lithium-ion battery. Alternatively, a secondary battery based on known principles may be included instead of a lithium-ion battery.

[0045] The first mounting platform 10 is a plate-shaped component mounted on the vehicle body 12 in a manner that covers the upper side of the vehicle body 12. In this embodiment, the first mounting platform 10 has a generally rectangular shape that is substantially the same as the shape of the vehicle body 12 when viewed from above.

[0046] Object detection sensor 11 detects objects outside the vehicle body 12 and provides the detection results to information processing unit 40. Information processing unit 40 creates a map based on the detection results of object detection sensor 11. During autonomous driving, information processing unit 40 determines its own position on the map based on the detection results of object detection sensor 11. In this embodiment, object detection sensor 11 is installed on the front, rear, left, and right surfaces of vehicle body 12. Figure 4 Only the object detection sensor 11, which is configured on the front and left surfaces, is shown in the image.

[0047] The object detection sensor 11 is a sensor capable of detecting objects within its detection range by receiving reflected light from detection light projected towards the outside of the vehicle body. As an example, the object detection sensor 11 is positioned between the vehicle body 12 and the first mounting platform 10, projecting detection light radially outwards from the object detection sensor 11. As an example, the object detection sensor 11 in this embodiment is a LiDAR (Light Detection and Ranging) sensor.

[0048] Obstacle sensor 19 detects obstacles outside vehicle body 12 and provides the detection results to information processing unit 40. During autonomous driving, information processing unit 40 controls the movement of the traveling vehicle 1 to avoid obstacles based on the detection results of object detection sensor 11 and obstacle sensor 19. In this embodiment, three obstacle sensors 19 are arranged on the front surface of vehicle body 12, and one on each of the left and right sides. Figure 4In the diagram, only one obstacle sensor 19 is shown, disposed on the front surface. For example, the obstacle sensor 19 is an optical sensor, and the optical axis of the detection light is tilted upward by 5 degrees relative to the horizontal plane.

[0049] Image sensor 18 detects guide marks attached to surfaces such as floors, ceilings, walls, shelves, etc., and provides the detection results to information processing unit 40. Guide marks in this embodiment include two-dimensional marks such as lines formed on the ground and QR codes. Image sensor 18 in this embodiment is a camera with a lens (not shown) and an imaging element (not shown), and is mounted on the front surface of vehicle body 12. When creating a map, information processing unit 40 stores the detection results of image sensor 18 as reference data corresponding to the map. During autonomous driving, information processing unit 40 compares the detection results of image sensor 18 with the stored reference data and uses the comparison result to determine its own position on the map.

[0050] The information processing unit 40 will be explained. Figure 6 The functional blocks of the information processing unit 40 shown can be implemented in hardware using computer processors, CPUs, memory, or other components, or electronic circuits and mechanical devices. They can also be implemented in software using computer programs. However, here, functional blocks implemented through their cooperation are described. Therefore, those skilled in the art should understand that these functional blocks can be implemented in various forms through a combination of hardware and software.

[0051] The information processing unit 40 includes an input unit 41, a path generation unit 42, a map generation unit 44, a self-position determination unit 45, a driving control unit 46, a storage unit 47, and a communication unit 48. These functional blocks can exchange information with each other via information transmission paths 43 such as a data bus.

[0052] The input unit 41 acquires the detection results from the sensor and the input information from the operation unit 17. The path generation unit 42 generates a driving path to the destination. The starting point of the driving path can be the current location or a separately set location. The starting point and destination can be input by the user via the operation unit 17 or by the host controller 60 via the communication unit 48. In this specification, the host controller 60 includes a computer system and portable information terminals such as smartphones and tablets.

[0053] When creating a map, the map generation unit 44 creates the map based on the detection results obtained by the onboard sensors through the input unit 41. During autonomous driving, the map generation unit 44 corrects the map based on the detection results obtained by the onboard sensors through the input unit 41.

[0054] During autonomous driving, the self-positioning unit 45 determines its own position on the map based on the detection results of the onboard sensors. During autonomous driving, the driving control unit 46 controls the wheel drive unit 16 based on the determined self-position to drive along the generated path. The storage unit 47 stores information input through the input unit 41, the map generated by the map generation unit 44, the path generated by the path generation unit 42, the determined self-position, etc. The communication unit 48 transmits and receives information with external devices such as the host controller 60 via wireless or wired communication lines.

[0055] Next, the assembly method of the trolley unit 100 will be described. The assembly method includes the following steps: covering the traction trolley 2 from above the traveling trolley 1; positioning the second platform 20 above the first platform 10; configuring the fence member 58 to surround the four sides of the traveling trolley 1; and connecting the traction trolley to the traveling trolley by engaging the protrusion 32 with the recess 36.

[0056] The driving operation of the assembled trolley unit 100 will be described. As an example, the trolley unit 100 begins driving when it receives a command to start the operation. This operation is mainly controlled by the information processing unit 40 of the driving trolley 1.

[0057] First, the information processing unit 40 generates a travel path for the traveling carriage 1 to reach its destination. At this time, the information processing unit 40 receives information about the origin and destination, along with their associated information, from the host controller 60 via the communication unit 48. The information processing unit 40 generates the travel path based on the destination and other information. This path generation can be achieved using the aforementioned SLAM technology.

[0058] Next, the information processing unit 40 causes the traveling carriage 1 to travel along the travel path. If it reaches the destination, the traveling carriage 1 stops traveling. At this time, the traction carriage 2, which is pulled by the traveling carriage 1, also reaches the destination.

[0059] The features of the trolley unit 100 according to this embodiment will be described. The trolley unit 100 is a trolley unit that includes a self-moving traveling trolley 1 and a traction trolley 2 towed by the traveling trolley 1. The traveling trolley 1 has a first loading platform 10 capable of carrying goods, and the traction trolley 2 has a second loading platform 20 capable of carrying goods. The second loading platform 20 is configured to cover the first loading platform 10 from above. The traveling trolley 1 and the traction trolley 2 are connected by fitting a protrusion 32 provided on the upper surface of the first loading platform 10 and a recess 36 provided on the lower surface of the second loading platform 20 with the protrusion 32 provided on the upper surface of the first loading platform 10 and the lower surface of the second loading platform 20.

[0060] According to this structure, the traveling trolley 1 can connect to and pull a traction trolley 2 that covers the shape of the traveling trolley 1. Therefore, it can be connected to various traction trolleys 2 of different sizes, and is not easily limited by the size of the traction trolley 2. Since the applicability of a single traveling trolley 1 is expanded, the utilization efficiency of the traveling trolley 1 is improved compared to the case where different sizes of traveling trolleys 1 are prepared according to the size of each traction trolley 2. In addition, since the variety of traveling trolleys 1 is reduced, the manufacturing cost of the traveling trolley 1 can be suppressed. Furthermore, compared with the structure of laterally connecting traction trolleys 2, the degree of freedom of the travel path is increased, and it can be used even in narrow spaces.

[0061] The embodiments of the present invention have been described in detail above. These embodiments are merely specific examples illustrating the implementation of the present invention. The content of the embodiments does not limit the technical scope of the present invention; various design changes, such as alterations, additions, and deletions of constituent elements, can be made without departing from the inventive concept defined by the claims. In the above embodiments, the content that allows such design changes is described using terms such as "in the embodiment" or "in the embodiment," but design changes are also permitted for content not described in such a way. Furthermore, the cross-sectional lines in the drawings do not limit the material of the object marked with cross-sectional lines.

[0062] [Variation Example] The following describes modified examples. In the accompanying drawings and descriptions of the modified examples, the same reference numerals are used to denote the same or equivalent components as in the embodiment. Descriptions that are repeated in the embodiment are omitted where appropriate, and the focus is on describing structures that differ from the embodiment.

[0063] In the above description, an example of the protrusion 32 and the recess 36 not moving forward or backward has been shown, but the present invention is not limited thereto. One or both of the protrusion 32 and the recess 36 may be configured to move forward or backward. Figure 7 This is a side sectional view showing a modified example of the connecting mechanism 30 with a retractable mechanism 56. In this modified example, the connecting mechanism 30 has a retractable mechanism 56 that moves the recess 36 forward and backward. The retractable mechanism 56, depending on the user's operation, moves the recess 36 backward when not connected and forward when connected. Figure 7 In the example, the retraction mechanism 56 is a hydraulic cylinder that moves the recess 36 up and down. In the retraction mechanism 56, a known retraction mechanism such as a parallel linkage mechanism or a cam mechanism driven by a motor (not shown) can be used instead of a hydraulic cylinder. The connecting mechanism 30 can also be configured to move the protrusion 32 up and down.

[0064] The above description shows an example where the second mounting stage 20 is a single layer, but the invention is not limited thereto. The second mounting stage can also be multi-layered.

[0065] In the above description, an example of a blind hole being shown for the recess 36 has been presented, but the present invention is not limited thereto. For example, the recess could also be a through hole.

[0066] In the above description, an example is shown where the second mounting platform 20 is separated from the first mounting platform 10 in the connected state, but the present invention is not limited thereto. In the connected state, the second mounting platform may also be in contact with the first mounting platform 10.

[0067] In the above description, an example is shown where the protrusion 32 and the second connecting member 34 are formed separately, but the present invention is not limited thereto. For example, the protrusion may also be formed integrally with the second connecting member.

[0068] In the above description, an example of a generally horizontally extending tubular component 58 is shown, but the invention is not limited thereto. For example, the fence component may be in a form other than tubular, such as a plate, rope, mesh, lattice, cloth, or membrane, or it may be a combination of these. For example, the fence component may be a structure extending in a direction other than horizontal, such as vertical or inclined, or it may be a combination of these.

[0069] In the above description, the traveling carriage 1 has four sides and is quadrilateral when viewed from above, but it is not limited to this. For example, it can be circular or triangular or other shapes when viewed from above. In this case, the guardrail component 58 only needs to be a structure that corresponds to the shape of the traveling carriage 1. Alternatively, the guardrail component 58 may not be present, and the guardrail component 58 may not be opposite a part of the side of the traveling carriage 1.

[0070] These variations also have the same effects as the implementation method.

[0071] Any combination of the above-described embodiments and modifications is also effective as an embodiment of the present invention. New embodiments resulting from combinations possess the effects of both the combined embodiments and modifications.

[0072] Industrial availability This invention can be applied to the field of trolley units and trolley unit assembly methods.

[0073] Symbol Explanation 1-Traveling trolley, 2-Traction trolley, 10-First mounting platform, 20-Second mounting platform, 32-Protrusion, 34-Second connecting component, 36-Recess, 37-Threaded hole, 38-First connecting component, 100-Trolley unit.

Claims

1. A trolley unit comprising: a self-propelled traveling trolley and a traction trolley towed by the traveling trolley, wherein, The traveling trolley has a first loading platform capable of carrying goods. The traction trolley has a second loading platform capable of carrying goods. The second mounting platform is configured to cover the first mounting platform from above. The traveling trolley and the traction trolley are connected by engaging a protrusion on the upper surface of the first platform and a recess on the lower surface of the second platform with the protrusion on the other.

2. The trolley unit according to claim 1, having a first connecting member detachably mounted on the upper surface of the first platform and having the recess.

3. The trolley unit according to claim 2, wherein, The first mounting platform has pre-installed threaded holes for mounting at least two types of auxiliary device components. The first connecting component is fixed to the threaded hole by bolts.

4. The trolley unit according to any one of claims 1 to 3, wherein, The protrusion is disposed on the first or second mounting platform in a manner that prevents displacement.

5. The trolley unit according to any one of claims 1 to 3, wherein, The protrusions and recesses are located at multiple positions that clamp the steering center of the traveling trolley.

6. The trolley unit according to any one of claims 1 to 3, wherein, The traction trolley has guardrail components that are respectively opposite to the four sides of the traveling trolley.

7. The trolley unit according to any one of claims 1 to 3, having a retraction mechanism for advancing or retracting the protrusion or the recess.

8. A method for assembling a trolley unit, the trolley unit comprising: a traveling trolley having a first loading platform capable of carrying goods and capable of self-movement, and a traction trolley having a second loading platform capable of carrying goods and towed by the traveling trolley, wherein, The traction trolley has guardrail components that are respectively opposite to the four sides of the traveling trolley. A protrusion is provided on one of the upper surface of the first mounting platform and a recess is provided on the other. The assembly method includes the following steps: The traction trolley is covered from above the traveling trolley; Position the second mounting platform above the first mounting platform; The fence components are configured to surround the four sides of the traveling trolley; and The traction trolley is connected to the traveling trolley by engaging the protrusion with the recess.

Images