Fork lifting device and transfer device with fork function

Abstract

To provide a fork lifting mechanism usable when a load is loaded on a load-carrying platform by reducing an impact applied to the load.SOLUTION: The fork is supported to be movable up and down with respect to the support portion. The force imparting part lifts and lowers the fork by suspending it by a tension transmission member hung on a fulcrum whose height from the support part is variable.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fork lifting device and a transfer device with a fork function. [Background technology]

[0002] Pallet loading devices that load pallets onto the bed of a vehicle are known. For example, Patent Document 1 describes a pallet loading device with multiple forks arranged in the width direction. This device inserts the multiple forks through pallet insertion openings, lifts the multiple pallets arranged in the width direction at once, and loads them onto the bed of the vehicle from the side. In this device, the forks include multiple fixed forks fixed to a main body support and multiple movable forks movably mounted on the main body support.

[0003] When loading cargo onto a loading platform from the side, space must be secured to the side of the platform for the loading equipment to move. When multiple trucks are lined up on a berth to be loaded, the method of loading cargo from the side of the platform makes it difficult to increase the number of trucks that can be parked on the berth at the same time. When a berth is full of trucks, the next truck to be loaded must wait outside the berth, which leads to increased man-hours.

[0004] On the other hand, when loading cargo from the rear of the loading platform, there is no need to secure space on the side of the platform for the loading device to move, which makes it possible to increase the number of trucks that can be parked at the berth at the same time.

[0005] A loading device using a roller conveyor is known as a device for efficiently loading multiple loads into a truck through an opening at the rear of the bed. In this loading device, the roller conveyor carrying multiple loads is transferred to the bed, and then the roller conveyor is returned from the bed, leaving the loads on the bed. In this way, multiple loads are efficiently loaded into the bed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-211748 Summary of the Invention [Problem to be solved by the invention]

[0007] When loading cargo using a conventional loading device, the cargo slides off the roller conveyor onto the floor of the loading platform as the roller conveyor returns from the platform. This causes the cargo to tilt and come into contact with the front wall of the platform or cargo already placed on the platform. Furthermore, the cargo is subjected to impact when sliding off the roller conveyor. The object of the present invention is to provide a fork lifting mechanism and a transfer device with fork function that can be used to load cargo onto a platform while reducing the impact on the cargo. [Means for solving the problem]

[0008] According to one aspect of the present invention, A support part; a fork supported on the support portion so as to be able to rise and fall; a force applying unit that raises and lowers the fork by suspending it with a tension transmitting member hung on a fulcrum whose height from the support unit is variable; A fork lifting device is provided.

[0009] According to another aspect of the present invention, a moving mechanism that holds and moves a load; the fork lifting device; Equipped with the support portion of the fork lifting device is disposed in a path of movement of the load held by the movement mechanism, The force application unit can support the load held by the movement mechanism from below and raise the fork to a height to receive the load from the movement mechanism, The support point can be lowered to a position lower than the load held by the moving mechanism. [Effects of the Invention]

[0010] By using the fork lifting device, a pallet on a roller conveyor can be lifted and transferred onto a loading platform. By using the fork lifting device to transfer a loaded pallet from the roller conveyor to a loading platform, the impact on the load can be reduced compared to the method of dropping the load from the roller conveyor onto the loading platform. In this way, the fork lifting device can be used when loading a load onto a loading platform while reducing the impact on the load. Furthermore, by using the transfer device with fork function, it is possible to load a load onto a loading platform while reducing the impact on the load. [Brief explanation of the drawings]

[0011] [Figure 1] 1A and 1B are schematic side views of a fork lifting device 19 according to a first embodiment. [Figure 2] Figure 2A is a diagram (part 1) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 2B is a diagram (part 1) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 3] Figure 3A is a diagram (part 2) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 3B is a diagram (part 2) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 4] Figure 4A is a diagram (part 3) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 4B is a diagram (part 3) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 5] Figure 5A is a diagram (part 4) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 5B is a diagram (part 4) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 6]Figure 6A is a diagram (part 5) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 6B is a diagram (part 5) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 7] Figure 7A is a diagram (part 6) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 7B is a diagram (part 6) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 8] Figure 8A is a diagram (part 7) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 8B is a diagram (part 7) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 9] Figure 9A is a diagram (part 8) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 9B is a diagram (part 8) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 10] Figure 10A is a diagram (part 9) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 10B is a diagram (part 9) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 11] Figure 11A is a diagram (part 10) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 11B is a diagram (part 10) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 12] Figure 12A is a diagram (part 11) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 12B is a diagram (part 11) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 13] Figure 13A is a diagram (part 12) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 13B is a diagram (part 12) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 14]Figure 14A is a diagram (part 13) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 14B is a diagram (part 13) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 15] Figure 15A is a diagram (part 14) showing the planar positional relationship between the transfer device and the truck according to the second embodiment, and Figure 15B is a diagram (part 14) showing the positional relationship when the transfer device and the truck according to the second embodiment are viewed from the side. [Figure 16] FIG. 16 is a schematic plan view of the transfer mechanism 40. As shown in FIG. [Figure 17] 17A and 17B are schematic side views of the fulcrum lifting mechanism 47. FIG. [Figure 18] 18A and 18B are schematic side views of the parallel link mechanism 46 and the fork 41. FIG. [Figure 19] 19A and 19B are schematic side views (part 1) of entrance section 30, transfer mechanism 40, pallet 60, and load 61 for illustrating the procedure by which transfer mechanism 40 transfers a pallet from entrance section 30 to loading platform 501. [Figure 20] 20A and 20B are schematic side views (part 2) of the entrance 30, the transfer mechanism 40, the pallet 60, and the load 61 for illustrating the procedure by which the transfer mechanism 40 transfers the pallet from the entrance 30 to the loading platform 501. [Figure 21] 21A and 21B are schematic side views (part 3) of entrance section 30, transfer mechanism 40, pallet 60, and load 61 for illustrating the procedure by which transfer mechanism 40 transfers a pallet from entrance section 30 to loading platform 501. [Figure 22] FIG. 22 is a schematic plan view of a transfer device according to the third embodiment. [Figure 23] 23A and 23B are schematic front views of the transfer mechanism 40 and the moving mechanism 80. FIG. [Figure 24] FIG. 24 is a schematic plan view showing the positional relationship between the transfer mechanism 40 and the movement mechanism 80 at an intermediate stage during the operation of the transfer device. DETAILED DESCRIPTION OF THE INVENTION

[0012] [First Example] A fork lifting device according to a first embodiment will be described with reference to Figures 1A and 1B. Figures 1A and 1B are schematic side views of a fork lifting device 19 according to the first embodiment. The fork lifting device 19 is configured on a support 10 that has mechanical support.

[0013] The fork 11 is supported by the fork support mechanism 12 so that it can be raised and lowered relative to the support part 10. The fork support mechanism 12 determines the movement path and posture of the fork 11 when raised and lowered. The fork 11 extends in a direction approximately parallel to the upper surface of the support part 10. The fork support mechanism 12 may be, for example, a linear guide mechanism that raises and lowers the fork 11 along a straight line, or a parallel link mechanism that raises and lowers the fork 11 along an arc. For example, arranging linear guide mechanisms at two different locations along the length of the fork 11 can stably maintain the posture of the fork 11. The force application part 17 applies a force to the fork 11 in a direction away from the support part 10. This force raises the fork 11. When this force weakens, the fork 11 descends under its own weight.

[0014] Next, the structure of the force application unit 17 will be described. The force application unit 17 includes a tension transmission member 13, a fulcrum 14, a fulcrum lifting mechanism 15, and a tensile force generating unit 16. A chain, for example, is used as the tension transmission member 13. Note that a wire or the like may be used instead of the chain. One end of the tension transmission member 13 is attached to the fork 11. The end attached to the fork 11 will be referred to as the first end 13A.

[0015] The fulcrum 14 is positioned higher than the fork 11 by a fulcrum lifting mechanism 15. A tension transmission member 13 is hung on the fulcrum 14, and a second end 13B opposite to the first end 13A is attached to a tensile force generating unit 16. When a chain is used as the tension transmission member 13, a sprocket is used as the fulcrum 14. When a wire is used as the tension transmission member 13, a pulley is preferably used as the fulcrum 14.

[0016] The tension generating unit 16 is supported by the support unit 10 and applies a tension to the tension transmission member 13. For example, a hydraulic cylinder can be used as the tension generating unit 16. When a hydraulic cylinder is used as the tension generating unit 16, the hydraulic cylinder is supported by the support unit 10 so as to be rotatable within the plane along which the tension transmission member 13 extends. Instead of a hydraulic cylinder, an electric motor can also be used as the tension generating unit 16.

[0017] When the tension generating unit 16 applies a tension to the tension transmission member 13, tension is applied to the fork 11 in a direction away from the support unit 10. When the tension generating unit 16 reduces the tension applied to the tension transmission member 13, the fork 11 descends due to its own weight. In this way, the force applying unit 17 raises and lowers the fork 11 by suspending it from the tension transmission member 13 hung on the fulcrum 14.

[0018] The fulcrum lifting mechanism 15 raises and lowers the fulcrum 14. The fulcrum lifting mechanism 15 may be a linear guide mechanism, a slider crank mechanism, a three-link mechanism with a variable length link, or the like. FIG. 1A shows the fulcrum 14 lowered to its lowest position, and FIG. 1B shows the fulcrum 14 raised to its highest position. When the fulcrum 14 is lowered to its lowest position (FIG. 1A), the angle between the direction of tension applied to the fork 11 and the direction of elevation of the fork 11 is larger than when the fulcrum 14 is raised to its highest position (FIG. 1B). Therefore, the tension applied to the fork 11 cannot be effectively used to raise the fork 11. To raise the fork 11, it is preferable to raise the fulcrum 14 to a higher position.

[0019] Furthermore, the fork 11 cannot be raised to a position higher than the fulcrum 14. By raising the fulcrum 14, the fork 11 can be raised to a higher position.

[0020] Next, the excellent effects of the first embodiment will be described. When the fulcrum 14 is raised, the height H from the top surface of the support part 10 to the highest position (position of the fulcrum 14) of the fork lifting device 19 increases. This limits the use of the space above the support part 10. As shown in FIG. 1A, when the fork lifting device 19 is lowered, the restrictions on the use of the space above the support part 10 are alleviated.

[0021] For example, there may be a case where a load platform is located higher than the forks 11, and it is desired to raise the forks 11 and hold a load placed on the load platform with the forks 11. There may also be a case where it is desired to move a load to the load platform by passing it over the fork lifting device 19. When a load passes over the fork lifting device 19, if the fork lifting device 19 is kept in a low position, the fork lifting device 19 is less likely to obstruct the passage of the load.

[0022] [Second Example] Next, a transfer device according to a second embodiment will be described with reference to Figures 2A to 21B. Figures 2A, 3A, 4A, ... 15A are diagrams showing the planar positional relationship between the transfer device and the track according to the second embodiment, and Figures 2B, 3B, 4B, ... 15B are diagrams showing the positional relationship when the transfer device and the track according to the second embodiment are viewed from the side.

[0023] As shown in Figures 2A and 2B, the transfer device according to the second embodiment includes an output platform 20, an entrance section 30, a transfer mechanism (fork lifting device) 40, a frame 50, a traverse carriage 51, and traverse rails 52. In Figure 2A, the entrance section 30 is hatched upward to the right. Note that a pallet 60 and a load 61, which will be described later, are hatched relatively lightly downward to the right. Similar hatching is used in Figures 3A, 4A, ..., and 15A. The operations of the output platform 20, the entrance section 30, the transfer mechanism 40, and the traverse carriage 51 are controlled by a control device 70.

[0024] The truck 500 is parked so that the loading / unloading entrance at the rear of the loading platform 501 of the truck 500 faces the transfer device. The entrance section 30 carrying multiple pallets 60 and loads 61 enters the loading platform 501, and the pallets 60 are transferred from the entrance section 30 to the loading platform 501, thereby loading the pallets 60 and loads 61 onto the loading platform 501. In this way, the entrance section 30 has the function of bringing multiple pallets 60 and loads 61 into the loading platform 501 from outside. The entrance section 30 can also be called a "load bringing-in section."

[0025] The direction in which the entrance section 30 enters the loading platform 501 is referred to as the first direction Da, and the direction perpendicular to the first direction Da in the horizontal plane is referred to as the second direction Db. The direction in which the entrance section 30 enters the loading platform 501 is referred to as the forward direction, and the opposite direction is referred to as the rearward direction. Either a double-sided or single-sided pallet may be used as the pallet 60. When using a single-sided pallet, it is necessary to use one with a shape that can be stably supported by the rollers 21 of the discharge platform 20, which will be described later.

[0026] Three pairs of lateral rails 52 are arranged parallel to the second direction Db on the floor of a work area where the load 61 is loaded onto the loading platform 501 of the truck 500. A lateral carriage 51 is placed on each of the lateral rails 52. The lateral carriage 51 is capable of moving in the second direction Db on the lateral rails 52. A frame 50 is supported by the three lateral carriages 51. Each of the lateral carriages 51 has a height adjustment mechanism that adjusts the height of the frame 50. By operating the lateral carriage 51, the height and position of the frame 50 are adjusted, and the transfer device and the loading platform 501 of the truck 500 are aligned.

[0027] The output table 20 is fixed on the frame 50. The shape of the output table 20 in a plan view is a rectangle that is long in the first direction Da. The output table 20 has a floor surface 20A along which the entrance section 30 and the transfer mechanism 40 move, and a side wall 20B that restricts the position of the entrance section 30 in the second direction Db. The output table 20 further has a plurality of rollers 21 arranged in two rows in the first direction Da. The two rows of rollers 21 form a two-row roller conveyor. The plurality of rollers 21 in each row are arranged from the rear end toward the front to a predetermined position.

[0028] The entrance section 30 has a plurality of wheels 32 and is capable of moving in the first direction Da on the floor surface 20A of the output table 20 and the floor surface of the loading platform 501. The entrance section 30 has three rows of rollers 31 aligned in the first direction Da. The three rows of rollers 31 form a roller conveyor. One row of rollers 31 is disposed between two rows of rollers 21 of the output table 20 in the second direction Db, and the other two rows of rollers 31 are disposed outside the rows of rollers 21 of the output table 20. As will be described later, the rollers 21 and rollers 31 function as a conveying path (moving mechanism) that conveys pallets and loads in the first direction Da.

[0029] The entry section 30 includes three roller support sections 30B that are long in the first direction Da and rotatably support each of the multiple rollers 31 arranged in three rows, and a connecting section 30A that connects the three roller support sections 30B at their intermediate positions.

[0030] An extension portion 34 extends rearward from each of the two ends of the rear end of the entrance portion 30. A guide roller 33 is attached to the outer side surface of the extension portion 34. The guide roller 33 contacts the side wall 20B of the carry-out table 20 to guide the entrance portion 30 in the first direction Da.

[0031] 2A and 2B show a state in which the position of the front end (hereinafter sometimes referred to as the tip) of the entry section 30 is approximately aligned with the position of the front end of the output table 20. At this time, in the first direction Da, a portion of the front side of the range in which the plurality of rollers 21 of the output table 20 are arranged overlaps with a portion of the rear side of the range in which the plurality of rollers 31 of the entry section 30 are arranged.

[0032] When the pallet 60 placed on the rollers 21 of the delivery table 20 is transported forward, it is handed over to the rollers 31 of the entrance section 30, and is further placed on the rollers 31 of the entrance section 30 and transported forward.

[0033] A transfer mechanism 40 is disposed between a portion in front of the central roller support portion 30B of the entrance section 30 and a portion in front of each of the roller support portions 30B at both ends. As will be described later, the transfer mechanism 40 has the function of lifting the pallet and load placed on the entrance section 30 and transferring them onto the loading platform 501 when the entrance section 30 has entered the loading platform 501.

[0034] The transfer mechanism 40 is equipped with a plurality of wheels 42 and is capable of moving in a first direction Da on the floor surface 20A of the output platform 20. Guide rollers 45 provided on the sides of the transfer mechanism 40 come into contact with the sides of the roller support parts 30B, thereby guiding the transfer mechanism 40 in the first direction Da. The transfer mechanism 40 is equipped with a drive shaft 43 extending rearward. A power source 44 attached to the entrance part 30 applies a force in the first direction Da to the drive shaft 43, causing the transfer mechanism 40 to move in the first direction Da.

[0035] Each transfer mechanism 40 has two forks 41 extending forward, and the forks 41 can be inserted into fork insertion portions of the pallet 60 to raise and lower the pallet 60. If the pallet 60 is a double-sided pallet, the forks 41 are inserted through insertion openings in the pallet 60. With the forks 41 lowered, the transfer mechanism 40 can assume a position in which its uppermost end is lower than the upper surfaces of the rollers 31 of the entrance section 30. This allows the pallet 60 placed on the rollers 31 to pass above the transfer mechanism 40. The lifting mechanism for the forks 41 will be described later with reference to Figures 16 to 21.

[0036] Before the approach section 30 starts moving forward toward the loading platform 501, the center line of the loading platform 501 in the width direction is made to coincide with the center line of the output platform 20 in the second direction Db. Here, "coincidence" means that the center line of the loading platform 501 and the center line of the output platform 20 are located on the same straight line. The center lines can be made to coincide by moving the three traversing vehicles 51 in the second direction Db.

[0037] For example, by moving the three traverse carriages 51 the same distance in the same direction, the output platform 20 can be translated in the second direction Db. By moving the front traverse carriage 51 and the rear traverse carriage 51 in opposite directions, the orientation of the output platform 20 in the rotational direction can be changed within the horizontal plane.

[0038] A plurality of pallets 60 carrying loads 61 are supplied from the rear end of the output table 20 onto a plurality of rollers 21 of the output table 20. The plurality of pallets 60 are supplied in rows of the rollers 21 of the output table 20. The pallets 60 placed on the rollers 21 of the output table 20 are transported forward by rotating the rollers 21 and handed over to the rollers 31 of the entrance section 30. The pallets 60 are then transported to a predetermined position by the rollers 31 of the entrance section 30. As a result, the output table 20 and the entrance section 30 hold a plurality of pallets 60 arranged in two rows in the first direction Da.

[0039] When the pallet 60 is being transported by the output table 20, the pallet 60 is supported by the rollers 21 of the output table 20 in the central portion in the second direction Db. After the pallet 60 is handed over to the entrance section 30, the pallet 60 is supported by the rollers 31 of the entrance section 30 near both ends in the second direction Db. In the overlapping region of the range in which the rollers 21 of the output table 20 are distributed and the range in which the rollers 31 of the entrance section 30 are distributed in the first direction Da, the pallet 60 is supported by both the rollers 21 and 31.

[0040] When multiple pallets 60 are supplied to the output platform 20 from its rear end and transported forward, a row of pallets 60 is formed, lined up closely together in the first direction Da from the rear end of the output platform 20 toward the front. The multiple pallets 60 lined up in the first direction Da are numbered sequentially, starting with 1, from the front pallet 60 toward the rear pallet 60, to distinguish between the multiple pallets 60. In the state shown in Figures 2A and 2B, a space is secured in which multiple pallets 60 can be placed from the first pallet 60 to the front end of the entrance 30.

[0041] After loading a plurality of pallets 60 and loads 61 onto the discharge platform 20 and the entrance section 30, as shown in Figures 3A and 3B, the rollers 31 of the entrance section 30 are rotated to transport the first pallet 60 to the front end of the entrance section 30. At this time, the transfer mechanism 40 is maintained in a low position, and the pallets 60 pass above the transfer mechanism 40. In other words, the transfer mechanism 40 is disposed on the path of movement of the pallets 60 and loads 61.

[0042] 4A and 4B, the entrance part 30 is moved forward to enter the loading platform 501. At this time, the entrance part 30 is stopped when the distance between the tip of the entrance part 30 and the wall surface on the far side of the loading platform 501 reaches a predetermined distance. The transfer mechanism 40 also moves forward together with the entrance part 30.

[0043] 5A and 5B, the transfer mechanism 40 is operated to insert the forks 41 into the insertion openings of the first pallet 60, and the pallet 60 is held by the forks 41. At this time, the space between the first pallet 60 and the second pallet 60 is used as a space for the forks 41 to pass through when inserting the forks 41 into the insertion openings of the pallets 60.

[0044] Next, as shown in Figures 6A and 6B, the entrance section 30 is retracted a distance equivalent to the dimension of one pallet 60. At this time, the transfer mechanism 40 is moved forward relative to the entrance section 30, thereby maintaining the transfer mechanism 40 in a substantially stationary state relative to the loading platform 501. In this state, the forks 41 of the transfer mechanism 40 protrude forward beyond the tip of the entrance section 30, and the first pallet 60 is raised above the floor surface of the loading platform 501. A space free of obstacles is secured between the underside of the pallet 60 and the floor surface of the loading platform 501.

[0045] Next, as shown in Figures 7A and 7B, the transfer mechanism 40 is operated to lower the forks 41. This places the first pallet 60 on the floor of the loading platform 501. By following the steps from Figures 5A to 7B, the first pallet 60 is transferred from the entrance 30 to the loading platform 501.

[0046] 8A and 8B, the entrance section 30 is moved backward a distance corresponding to the dimension of the pallet 60 in the first direction Da. At this time, the transfer mechanism 40 is moved rearward relative to the entrance section 30. As a result, the forks 41 of the transfer mechanism 40 are lowered rearward beyond the tip of the entrance section 30.

[0047] 9A and 9B, the rollers 31 of the entrance section 30 are rotated to transport the second pallet 60 (the frontmost pallet 60 currently loaded on the entrance section 30) to the end of the entrance section 30. At this time, the transfer mechanism 40 is in a low position, and the pallet 60 passes above the transfer mechanism 40.

[0048] 10A and 10B, the transfer mechanism 40 is operated to transfer the second pallet 60 from the entrance 30 onto the loading platform 501. At this time, the operation of the transfer mechanism 40 is controlled so that the distance between the first pallet 60 and the second pallet 60 is a predetermined distance.

[0049] By repeating the steps of retracting the entrance section 30 (Figures 8A and 8B), transporting the frontmost pallet 60 loaded on the entrance section 30 to the tip of the entrance section 30 (Figures 9A and 9B), and transferring the pallet 60 that has been transported to the tip of the entrance section 30 from the entrance section 30 to the loading platform 501 (Figures 10A and 10B), multiple pallets 60 are transferred from the entrance section 30 to the loading platform 501.

[0050] 11A and 11B show the state where the first through sixth pallets 60 have been transferred from the entrance 30 to the loading platform 501. In this state, the seventh pallet 60 and load 61 remain in the entrance 30.

[0051] 12A and 12B, by rotating the rollers 21 of the output platform 20 and the rollers 31 of the entrance 30, some of the pallets 60 and loads 61 remaining on the output platform 20 are transported to the entrance 30. For example, the eighth, ninth, and tenth pallets 60 are transported from the output platform 20 to the entrance 30.

[0052] At this time, the pallet 60 passes through an overlapping area between the area where the rollers 21 of the discharge platform 20 are arranged and the area where the rollers 31 of the entrance section 30 are arranged. In the overlapping area, both ends of the load in the second direction Db rest on the rollers 31 of the entrance section 30, and the center portion rests on the rollers 21 of the discharge platform 20. This allows the load to be stably transferred from the discharge platform 20 to the entrance section 30.

[0053] As shown in Figures 13A and 13B, the pallets 60 on the entrance section 30 are transferred onto the loading platform 501 in order, starting with the frontmost pallet 60. Figures 14A and 14B show the loading platform 501 full with the first through tenth pallets 60 loaded onto it. Figures 14A and 14B show the loading platform 501 full with the leading edge of the entrance section 30 remaining inside the loading platform 501. The entrance section 30 is then retracted and removed from the loading platform 501.

[0054] 15A and 15B, a plurality of pallets 60 and loads 61 are newly supplied to the output table 20 from the rear end of the output table 20. This results in the same state as shown in FIGS. 2A and 2B.

[0055] Next, the structure and operation of the transfer mechanism 40 will be described with reference to FIGS. 16 to 21B. 16 is a schematic plan view of the transfer mechanism 40. A plurality of wheels 42 are attached to a support plate 48. The wheels 42 enable the transfer mechanism 40 to move in a first direction Da on the floor surface 20A of the output platform 20 (FIGS. 2A, 2B, etc.) and the floor surface of the loading platform 501 (FIGS. 4A, 4B, etc.). A plurality of guide rollers 45 protruding laterally from the support plate 48 come into contact with the side surfaces of the roller support portions 30B of the entrance portion 30, thereby guiding the support plate 48 in the first direction Da.

[0056] Two forks 41 extend forward of a support plate 48. Each of the two forks 41 is attached to the support plate 48 via a parallel link mechanism 46. A fulcrum lifting mechanism 47 raises and lowers a fulcrum joint 47C. A plurality of sprockets 49C are connected to the fulcrum joint 47C via rods 49D, and the sprockets 49C rise and lower together with the fulcrum joint 47C.

[0057] 17A and 17B are schematic side views of the fulcrum lifting mechanism 47. A fixed-length link 47A and a variable-length link 47B are attached to a support plate 48. The fixed-length link 47A and the variable-length link 47B are connected by a fulcrum joint 47C. The variable-length link 47B includes, for example, a hydraulic cylinder, and its length can be changed. The fixed-length link 47A, the variable-length link 47B, and a portion of the support plate 48 form a three-bar linkage mechanism in which the length of one link is variable.

[0058] When variable length link 47B is extended, fulcrum joint 47C rises relative to support plate 48 as shown in FIG. 17A, and when variable length link 47B is contracted, fulcrum joint 47C descends relative to support plate 48 as shown in FIG. 17B.

[0059] Instead of the variable-length link 47B, a slider crank mechanism may be employed in which one of the joints at both ends of the link formed by the support plate 48 slides along the support plate 48.

[0060] 18A and 18B are schematic side views of the parallel link mechanism 46 and the fork 41. The parallel link mechanism 46 has the support plate 48 as one link and the base of the fork 41 as another link parallel to the support plate 48. A fulcrum joint 47C (FIGS. 17A and 17B) is disposed above the support plate 48. As described with reference to FIGS. 17A and 17C, the fulcrum joint 47C can be raised and lowered relative to the support plate 48. FIGS. 18A and 18B show a state in which the fulcrum joint 47C is raised.

[0061] A sprocket 49C is attached to the fulcrum joint 47C via a rod 49D (FIG. 16), and the sprocket 49C also moves up and down relative to the support plate 48 together with the fulcrum joint 47C. One end of a hydraulic cylinder 49A is rotatably attached to the support plate 48 at a location rearward of the parallel link mechanism 46. A chain 49B is connected to the other end of the hydraulic cylinder 49A and to the fork 41 via the sprocket 49C. The fork 41 is suspended by the chain 49B. When the hydraulic cylinder 49A is extended or retracted, the fork 41 moves up and down relative to the support plate 48 along a movement path defined by the parallel link mechanism 46. Furthermore, the parallel link mechanism 46 determines the posture of the fork 41 when it moves up and down. This allows the fork 41 to stably support a load when it moves up and down.

[0062] Fig. 18A shows a state in which the hydraulic cylinder 49A is extended to lower the fork 41. Fig. 18B shows a state in which the hydraulic cylinder 49A is retracted to raise the fork 41.

[0063] 19A to 21B, a procedure by which the transfer mechanism 40 transfers the pallet 60 from the entrance 30 onto the loading platform 501 will be described. Figures 19A to 21B are schematic side views of the entrance 30, the transfer mechanism 40, the pallet 60, and the load 61 to explain the procedure by which the transfer mechanism 40 transfers the pallet 60 from the entrance 30 onto the loading platform 501.

[0064] As shown in FIG. 19A, by operating the fulcrum lifting mechanism 47, the sprocket 49C is lowered to a position lower than the highest position of the roller surfaces of the rollers 31 of the entrance section 30 (a position lower than the pallet 60 and load 61 held in the entrance section 30), thereby placing the transfer mechanism 40 in a low position. In this state, the rollers 31 of the entrance section 30 are rotated to transport the pallet 60 forward. At this time, the pallet 60 passes above the transfer mechanism 40. This procedure corresponds to the procedure for transporting the pallet 60 to the tip of the entrance section 30 shown in FIGS. 3B, 9B, etc.

[0065] Next, as shown in Figure 19B, after the pallet 60 is transported to the tip of the entry section 30, the fulcrum lifting mechanism 47 is operated to raise the fulcrum joint 47C and sprocket 49C to a position higher than the upper surface of the roller 31 of the entry section 30.

[0066] Next, as shown in FIG. 20A, the hydraulic cylinder 49A is retracted to raise the forks 41. At this time, the height of the forks 41 is adjusted to match the height of the insertion opening of the pallet 60 located at the tip of the entrance section 30. Next, as shown in FIG. 20B, the power source 44 (FIG. 2A) is operated to move the transfer mechanism 40 forward. As the transfer mechanism 40 moves forward, the forks 41 are inserted into the insertion opening (fork insertion section) of the pallet 60. Thereafter, the hydraulic cylinder 49A is further retracted to raise the forks 41 and receive the pallet 60 from the entrance section 30. As a result, the pallet 60 rises from the rollers 31 of the entrance section 30. In this way, the forks 41 support the pallet 60 and the load 61 held in the entrance section 30 from below and receive them from the entrance section 30. This state corresponds to the state shown in FIG. 5B.

[0067] Next, as shown in FIG. 21A, the entrance section 30 is retracted. At this time, the power source 44 (FIG. 2A) is operated to move the transfer mechanism 40 forward relative to the entrance section 30. This causes the transfer mechanism 40 to remain stationary with respect to the floor surface of the loading platform 501. In this state, the underside of the pallet 60 and the floor surface of the loading platform 501 directly face each other with a gap between them. For example, a state is achieved in which no obstacles exist between the entire underside of the pallet 60 and the floor surface of the loading platform 501.

[0068] Next, as shown in Figure 21B, hydraulic cylinder 49A is extended to lower fork 41. This places pallet 60 on the floor of platform 501. By performing the steps from Figure 19A to Figure 21B, pallet 60 can be transferred from entrance 30 to the floor of platform 501.

[0069] In this way, in the transfer device of the second embodiment, the transfer mechanism 40 transfers the multiple pallets 60 placed on the entry section 30 onto the loading platform 501 in order, starting from the first pallet 60 on the front side in the first direction Da to the pallet 60 on the rear side.

[0070] Next, the excellent effects of the second embodiment will be described. In the second embodiment, a plurality of pallets 60 lined up in the first direction Da are loaded into the loading platform 501 of the truck 500 at one time from the rear of the loading platform 501. This allows the pallets 60 to be loaded into the loading platform 501 more efficiently than if they were loaded one by one.

[0071] Furthermore, in the second embodiment, the transfer mechanism 40 supports the pallet 60 from below and lifts it to a height at which it can be received from the entrance 30, then raises the underside of the pallet 60 above the floor of the loading platform 501, and then lowers the pallet 60 from this state. This provides the excellent effect of preventing the load 61 from becoming tilted and reducing the impact on the load 61 compared to a method in which the pallet 60 is slid forward from the tip of the entrance 30 and dropped onto the loading platform 501. Furthermore, it is easy to adjust the spacing between the pallets 60 lined up in the first direction Da within the loading platform 501.

[0072] Furthermore, as shown in FIG. 19A , the transfer mechanism 40 can be changed to a low posture by lowering the fulcrum joint 47C and the sprocket 49C. As shown in FIG. 4B , in order to allow the pallet 60 to pass above the transfer mechanism 40, the height of the upper ends of the roller surfaces of the rollers 31 of the entrance section 30 must be higher than the height of the transfer mechanism 40. If the transfer mechanism 40 cannot be changed to a low posture, the height of the entrance section 30 must also be increased in accordance with the height of the transfer mechanism 40. If the height of the entrance section 30 is increased, the height of the load 61 is limited so that the load 61 does not contact the ceiling of the loading platform 501. In the second embodiment, the transfer mechanism 40 can be changed to a low posture, which makes it possible to lower the height of the entrance section 30. As a result, the height restriction on the load 61 is alleviated.

[0073] 12A and 12B, in the second embodiment, with a portion of the front side of the entrance 30 inserted into the loading platform 501, the pallets 60 and loads 61 can be transported from the discharge platform 20 to the entrance 30, and the pallets 60 and loads 61 can be replenished into the entrance 30. Since the pallets 60 and loads 61 can be supplied without the entire entrance 30 being removed from the loading platform 501, the pallets 60 and loads 61 can be loaded onto the loading platform 501 efficiently.

[0074] 15A and 15B, new pallets 60 and loads 61 are supplied to the output table 20. Alternatively, as shown in FIGS. 4A and 4B, after some pallets 60 and loads 61 placed on the output table 20 are transported forward and there is enough space on the output table 20 to place new pallets 60, new pallets 60 and loads 61 can be supplied to the output table 20 at any stage.

[0075] That is, even while the pallet 60 and the load 61 are being transferred from the entrance 30 to the loading platform 501, a new pallet 60 and load 61 can be supplied to the output platform 20. This makes it possible to improve loading efficiency.

[0076] Furthermore, in the second embodiment, by adjusting the position of the traversing carriage 51 (FIG. 2B) in the second direction Db, it is possible to adjust the position of the center line of the output platform 20 in the second direction Db and the position in the rotational direction on the horizontal plane. As a result, when the truck 500 is stopped, even if the position and orientation of the center line of the loading platform 501 deviate from the predetermined position and orientation, the center line of the output platform 20 can be aligned with the center line of the loading platform 501.

[0077] Next, a modification of the second embodiment will be described. In order to prevent the loads from coming into contact with each other or collapsing due to shaking during transportation, cushioning material may be inserted between the loads 61 adjacent in the front-rear direction. In this modification, cushioning material is inserted between the loads 61 adjacent in the front-rear direction before the entrance 30 starts moving forward toward the loading platform 501. Next, a configuration for placing cushioning material between the loads 61 and maintaining its position will be described.

[0078] The buffer material is suspended from a hanging holder disposed on the top surface of the load 61, and is disposed along one side of the load 61 (for example, the side facing forward). The buffer material and the hanging holder have an inverted L shape when viewed from the side. The hanging holder is sufficiently heavier than the buffer material so that the position of the buffer material remains stable even when it is hung.

[0079] By placing buffer materials between the loads 61 before loading the multiple pallets 60 and loads 61 onto the loading platform 501, it becomes unnecessary to place buffer materials after or during loading of the loads 61 onto the loading platform 501. This makes it possible to improve the efficiency of the loading work.

[0080] [Third Example] Next, a transfer device according to a third embodiment will be described with reference to Figures 22 to 23B. Figure 22 is a schematic plan view of the transfer device according to the third embodiment. The transfer device according to the third embodiment includes a transfer mechanism 40 having substantially the same configuration as the transfer mechanism 40 of the transfer device according to the second embodiment, and a movement mechanism 80.

[0081] The moving mechanism 80 holds a pallet 91 and a load 92 and moves in a first direction Da on the floor surface where the load is to be placed. The transfer mechanism 40 is disposed on a movement path 90 for the pallet 91 and the load 92. The transfer mechanism 40 according to the first embodiment moves in the first direction Da by a power source 44 ( FIG. 2A ) attached to the entrance 30, but the transfer mechanism 40 according to the third embodiment is equipped with a power source 44A that drives wheels 42.

[0082] The movement mechanism 80 includes a pair of holding parts 81 arranged at an interval in a second direction Db perpendicular to the first direction Da in a horizontal plane, a connecting part 83 connecting the pair of holding parts 81, and a plurality of wheels 82. The movement mechanism 80 can move in the first direction Da by driving the wheels 82. A pallet 91 and a load 92 are held by the pair of holding parts 81 so as to straddle the pair of holding parts 81.

[0083] The connecting portion 83 is fixed to the pair of holding portions 81 on the side opposite to the side to which the tips of the forks 41 of the transfer mechanism 40 face. In other words, the connecting portion 83 is disposed on the rear side when viewed from the pallet 91 and the load 92.

[0084] 23A and 23B are schematic front views of the transfer mechanism 40 and the moving mechanism 80. Fig. 23A shows the transfer mechanism 40 in a high position, and Fig. 23B shows the transfer mechanism 40 in a low position.

[0085] As shown in Figure 23A, the transfer mechanism 40 can be set in a high position to align the forks 41 with the height of the insertion opening of the pallet 91. At this time, the sprocket 49C and fulcrum joint 47C of the transfer mechanism 40 do not overlap with the holding portion 81 and the connecting portion 83 when viewed from the front. Therefore, the transfer mechanism 40 can be moved forward from the rear side of the pallet 91 (the far side of the paper in Figure 23A) to insert the forks 41 into the pallet 91. Furthermore, the pallet 91 held by the moving mechanism 80 can be supported from below, and the forks 41 can be raised to a height at which they can be received from the moving mechanism 80.

[0086] As shown in FIG. 23B, the fulcrum joint 47C and the sprocket 49C can be lowered to a position lower than the pallet 91 held by the moving mechanism 80.

[0087] Next, the loading operation of the transfer device according to the third embodiment will be described with reference to Fig. 24 etc. Fig. 24 is a schematic plan view showing the positional relationship between the transfer mechanism 40 and the moving mechanism 80 at an intermediate stage in the operation of the transfer device.

[0088] First, the moving mechanism 80 holding the pallet 91 and the load 92 is positioned (state in FIG. 22) behind the transfer mechanism 40 (FIG. 23B) which has been lowered, and both are moved forward and entered into the loading platform. As shown in FIG. 24, the transfer mechanism 40 is stopped, and the moving mechanism 80 is moved further forward. At this time, the pallet 91 and the load 92 pass above the transfer mechanism 40 and move forward of the forks 41.

[0089] Thereafter, the transfer mechanism 40 is raised to a high position, the forks 41 are inserted into the pallet 91 (FIG. 23A), and the forks 41 are further raised to lift the pallet 91 from the holders 81 of the moving mechanism 80. The moving mechanism 80 is then moved backward to ensure that there are no obstacles between the pallet 91 and the floor of the loading platform (the same state as in FIG. 21A), and then the pallet 91 is lowered to the floor (the same state as in FIG. 21B). By following the procedure up to this point, the pallet 91 and load 92 loaded on the moving mechanism 80 can be transferred to the floor of the loading platform.

[0090] Next, the excellent effects of the third embodiment will be described. In the third embodiment, by moving the moving mechanism 80 back and forth while leaving the transfer mechanism 40 on the loading platform, it is possible to sequentially load a plurality of pallets 91 and loads 92 onto the loading platform. In parallel with the operation of the transfer mechanism 40 to raise and lower the forks 41, the moving mechanism 80 can retract from the loading platform and return to the loading platform holding a new pallet 91 and load 92. This makes it possible to improve the efficiency of the loading operation.

[0091] The above-described embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. Similar effects resulting from similar configurations of multiple embodiments will not be mentioned sequentially for each embodiment. Furthermore, the present invention is not limited to the above-described embodiments. For example, it will be obvious to those skilled in the art that various modifications, improvements, combinations, etc. are possible. [Explanation of symbols]

[0092] 10 Support part 11. Fork 12 Fork support mechanism 13 Tension transmission member 14 Fulcrum 15 Support lifting mechanism 16. Tensile force generating section 17 Force applying section 19 Fork lifting device 20 Loading platform 20A Floor 20B side wall 21 Roller 30 Entry section 30A connection part 30B Roller support 31 Roller 32 wheels 33 Guide roller 34 Stretching section 40 Transfer mechanism 41 Fork 42 wheels 43 Drive shaft 44, 44A Power source (motor) 45 Guide roller 46 Parallel link mechanism 47 Support lifting mechanism 47A Fixed Length Link 47B Variable Length Link 47C Fulcrum Joint 48 Support Plate 49A Hydraulic Cylinder 49B Chain 40C sprocket 49D Rod 50 frames 51 Traverse cart 52 Traverse rail 60 pallets 61 Load 70 Control device 80 Moving mechanism 81 Holding part 82 wheels 83 Connecting part 90 Cargo movement route 91 Palettes 92 Load 500 Trucks 501 Cargo bed

Claims

1. A support part; a fork supported on the support portion so as to be able to rise and fall; a force applying unit that raises and lowers the fork by suspending it with a tension transmitting member hung on a fulcrum whose height from the support unit is variable; A fork lifting device equipped with a

2. The fork lifting device according to claim 1 , wherein the support portion has a tension generating portion that applies tension to the tension transmitting member.

3. 3. The fork lifting device according to claim 1, wherein the forks are supported on the support parts by a fork support mechanism that defines a movement path and a posture of the forks when lifting or lowering.

4. 4. The fork lifting device according to claim 3, wherein the fork support mechanism includes a parallel link mechanism in which a part of the fork and a part of the support part are configured as a pair of links parallel to each other.

5. 3. The fork lifting device according to claim 1, wherein the fulcrum is connected to one joint of a three-bar linkage, one link of the three-bar linkage is formed as part of the support portion, and the length of at least one link is variable.

6. a moving mechanism that holds and moves a load; The fork lifting device according to claim 1 or 2, Equipped with the support portion of the fork lifting device is disposed in a path of movement of the load held by the movement mechanism, The force application unit can support the load held by the movement mechanism from below and raise the fork to a height to receive the load from the movement mechanism, A transfer device with a fork function that can lower the fulcrum to a position lower than the load held by the moving mechanism.

7. 7. The transfer device with fork function according to claim 6, wherein the moving mechanism is a roller conveyor.

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