Material handling equipment

Abstract

To provide an article transfer device that can reduce the generation of particles.SOLUTION: An article transfer device (1) has a lifting platform (20) movable along a pillar (10), a toothed belt (30) stretched from the lifting platform along the pillar, a first pulley (41) provided on one side in the vertical direction to the lifting platform, a second pulley (42) provided on the other side, and a drive unit (50) that rotationally drives the first pulley. The second pulley is a flat pulley.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an article conveying device for conveying articles.

Background Art

[0002] Patent Document 1 discloses an article conveying device for conveying articles. In the article conveying device, a lifting table that is guided by four lifting guide masts and is movable up and down is supported by suspension with four cable bodies. A toothed belt as the four cable bodies is respectively wound around a toothed pulley provided at the upper end of each lifting guide mast and configured as a driven rotating body, and a toothed pulley provided at the lower end of each lifting guide mast and driven by a lifting drive device.

Prior Art Documents

Patent Documents

[0003] Japanese Unexamined Patent Application Publication No. 2014-97858

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventor has clarified that in such an article conveying device, as the driving time becomes longer, the toothed belt wears, and there is a problem that particles of the toothed belt material are generated.

[0005] One aspect of the present invention aims to realize an article conveying device capable of reducing the generation of particles.

Means for Solving the Problems

[0006] To solve the above problems, an article conveying device according to one aspect of the present invention comprises a support column whose longitudinal direction is vertical, a lifting platform provided along the support column so as to be movable in the vertical direction, a toothed belt stretched upward and downward from the lifting platform along the support column, a first pulley provided on the support column on one side of the lifting platform in the vertical direction and around which the toothed belt is wound, a second pulley provided on the support column on the other side of the lifting platform in the vertical direction and around which the toothed belt is wound, and a drive device for rotationally driving the first pulley, wherein the first pulley is a toothed pulley that meshes with the toothed belt, and the second pulley is a flat pulley. [Effects of the Invention]

[0007] According to one aspect of the present invention, the generation of particles can be reduced. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic front view showing the article transport device according to Embodiment 1. [Figure 2] This is a cross-sectional view near the first pulley. [Figure 3] This is a cross-sectional view near the second pulley. [Modes for carrying out the invention]

[0009] [Embodiment 1] One embodiment of the present invention will be described in detail below. For the sake of clarity, the up-down and left-right directions are defined as shown by the arrows in Figure 1 and other figures. In this embodiment, the up-down direction corresponds to the vertical direction. The left-right direction is perpendicular to the up-down direction. Furthermore, "A~B" indicating a numerical range means "greater than or equal to A and less than or equal to B" unless otherwise specified.

[0010] Figure 1 is a schematic front view of an article conveying device 1 according to Embodiment 1. The article conveying device 1 is a device that conveys items in the vertical direction. Specifically, the article conveying device 1 may be an article lifting device installed in a stocker or automated warehouse, or a stacker crane installed in an automated warehouse. As shown in Figure 1, the article conveying device 1 comprises a support column 10, a lifting platform 20, a toothed belt 30, a first pulley 41, a second pulley 42, a drive device 50, and a counterweight 60. Furthermore, the article conveying device 1 includes a known configuration (not shown) for controlling the lifting and lowering of the lifting platform 20.

[0011] The support column 10 is a columnar member whose longitudinal direction is vertical when the article conveying device 1 is in use. The article conveying device 1 is provided with two support columns 10. The two support columns 10 are spaced apart from each other in the left-right direction. However, the number of support columns 10 provided in the article conveying device 1 is not limited to two. An upper frame 11 is provided above the two support columns 10. The upper frame 11 is provided so as to connect the upper ends of the two support columns 10.

[0012] The lifting platform 20 is a component on which the object to be transported by the item transport device 1 is placed. The lifting platform 20 is located between the two support columns 10. The lifting platform 20 is provided to be movable vertically along the support columns 10. In Figure 1, the lifting platform 20 located below the movable range is shown by a solid line. Also in Figure 1, the lifting platform 20 located above the movable range is shown by a dashed line.

[0013] The toothed belt 30 is stretched upward and downward from the lifting platform 20 along the support columns 10. Specifically, the lifting platform 20 is equipped with lifting frames 21 on each of its left and right sides. The lifting frames 21 have a structure that allows the ends of the toothed belt 30 to be clamped at the top and bottom. The toothed belt 30, with its ends clamped by the lifting frames 21, is stretched vertically. The toothed belt 30 is provided on each of the two support columns 10. As the toothed belt 30 is driven around the support columns 10, the lifting platform 20 moves up and down along the support columns 10.

[0014] The first pulley 41 and the second pulley 42 are pulleys around which the toothed belt 30 is wound. The first pulley 41 and the second pulley 42 are provided on each of the two support columns 10. The first pulley 41 is provided on the support column 10 on one side in the vertical direction relative to the lifting platform 20. The second pulley 42 is provided on the support column 10 on the other side in the vertical direction relative to the lifting platform 20.

[0015] Figure 2 is a cross-sectional view of the vicinity of the first pulley 41. Figure 3 is a cross-sectional view of the vicinity of the second pulley 42. As shown in Figure 2, the first pulley 41 is a toothed pulley that meshes with the toothed belt 30. On the other hand, as shown in Figure 3, the second pulley 42 is a flat pulley.

[0016] The drive unit 50 rotates the first pulley 41. The drive unit 50 is provided on each of the two support columns 10. As described above, the first pulley 41 meshes with the toothed belt 30. Therefore, the toothed belt 30 is driven in conjunction with the rotational drive of the first pulley 41 by the drive unit 50, causing the lifting platform 20 to move up and down along the support columns 10.

[0017] The article conveying device 1 does not have a drive device to rotate the second pulley 42. That is, the second pulley 42 is a driven pulley that rotates due to power transmitted from the first pulley 41 via the toothed belt 30. As described above, the second pulley 42 is a flat pulley. Therefore, the second pulley 42 rotates due to friction with the tips of the teeth of the toothed belt 30.

[0018] The contact area between the second pulley 42, which is a flat pulley, and the toothed belt 30 is smaller than the contact area between the second pulley 42 and the toothed belt 30 when the second pulley 42 is a toothed pulley meshing with the teeth of the toothed belt 30. Therefore, the wear of the toothed belt 30 due to friction with the second pulley 42 is reduced. As a result, the generation of particles of the material of the toothed belt 30 caused by the wear of the toothed belt 30 on the second pulley 42 is reduced. Also, by making the second pulley 42 a flat pulley, the manufacturing cost of the second pulley 42 is reduced as compared with the case where the second pulley 42 is a toothed pulley.

[0019] In the present embodiment, the first pulley 41 is provided on the support column 10 on the lower side with respect to the lifting table 20. In other words, the second pulley 42 is provided on the support column 10 on the upper side with respect to the lifting table 20. Therefore, by reducing the generation of particles in the second pulley 42, the fall of the particles onto the conveyed object placed on the lifting table 20 is also reduced.

[0020] The counterweight 60 moves along the support column 10 in the direction opposite to the moving direction of the lifting table 20 when the lifting table 20 moves. In the article conveying device 1, the lifting table 20, the toothed belt 30, and the counterweight 60 form a closed loop. The lifting table 20 and the counterweight 60 are arranged at opposite positions in the loop. Here, the opposite positions do not necessarily mean completely opposite positions, and it is sufficient if they can be regarded as substantially opposite.

[0021] By the article conveying device 1 including the counterweight 60, the energy required for the movement of the lifting table 20 becomes smaller as compared with the case where the article conveying device 1 does not include the counterweight 60. The weight of the counterweight 60 may be appropriately determined by the designer of the article conveying device 1 in consideration of the weight of the lifting table 20 and the weight of the assumed conveyed object. However, the counterweight 60 is not essential in the article conveying device 1 and may be omitted.

[0022] The toothed belt 30 may include a first toothed belt 31 and a second toothed belt 32. The first toothed belt 31 is wound around the first pulley 41 to connect the lifting platform 20 and the counterweight 60. The second toothed belt 32 is wound around the second pulley 42 to connect the lifting platform 20 and the counterweight 60. As described above, in the present embodiment, the first pulley 41 is located below the lifting platform 20, and the second pulley 42 is located above the lifting platform 20. Therefore, the first toothed belt 31 is stretched downward along the column 10 from the lifting platform 20. Also, the second toothed belt 32 is stretched upward along the column 10 from the lifting platform 20.

[0023] In the article conveying device 1, since the toothed belt 30 includes the first toothed belt 31 and the second toothed belt 32, for example, compared with the case where the toothed belt 30 is a single toothed belt, the length of each belt can be shortened. Therefore, the first toothed belt 31 and the second toothed belt 32 can be procured more easily than the toothed belt 30 which is a single toothed belt. Also, when one of the first toothed belt 31 and the second toothed belt 32 is worn, only the worn belt needs to be replaced. Therefore, compared with the case of replacing the entire toothed belt 30, the maintenance cost of the article conveying device 1 can also be reduced.

[0024] In the present embodiment, the first toothed belt 31 and the second toothed belt 32 are separate members having the same shape as each other. Therefore, compared with the case where the first toothed belt 31 and the second toothed belt 32 have different shapes from each other, it is easy to procure parts. However, the first toothed belt 31 and the second toothed belt 32 do not necessarily have the same shape as each other.

[0025] Furthermore, if a flat belt were to be used instead of the toothed belt 32, it would be necessary to drill holes in the flat belt in order to attach the toothed belt 32 to the lifting frame 21 and the counterweight 60. In the article conveying device 1, by using the toothed belt 32 and providing the lifting frame 21 and the counterweight 60 with a structure to clamp the toothed belt 32, the drilling process that was necessary when using a flat belt becomes unnecessary.

[0026] However, the toothed belt 30 does not necessarily have to include the first toothed belt 31 and the second toothed belt 32; for example, it may be a single toothed belt. In this case, the counterweight 60 may be attached, for example, by clamping the toothed belt 30 from both sides.

[0027] (Example of experiment) The inventors of the present invention prototyped and test-ran the article conveying devices of the embodiment and comparative example. The article conveying device of the embodiment was equipped with a second pulley 42, which is a flat pulley as described above. The article conveying device of the comparative example was equipped with a toothed pulley that meshes with the toothed belt 30, similar to the first pulley 41, instead of the second pulley 42 which is a flat pulley. In the test run, it was assumed that the article conveying device would be raised and lowered 1440 times per day, and the device was operated continuously for 2.5 years.

[0028] After the trial run, the comparative example's article conveying device showed particle generation around the toothed pulley used in place of the second pulley 42, due to wear of the toothed belt 30. On the other hand, no particle generation was observed around the second pulley 42 in the embodiment's article conveying device. Therefore, it can be said that in the embodiment's article conveying device, the generation of particles was reduced compared to the comparative example's article conveying device by using a flat pulley for the second pulley 42.

[0029] Incidentally, in general, belt meandering can be a problem in devices driven by belts. However, in this trial run, no significant difference was observed in the amount of meandering of the toothed belt 30 in either the example or the comparative example of the article conveying device. In other words, the problem of the amount of meandering of the toothed belt 30 in the example article conveying device being greater than that of the comparative example article conveying device did not occur.

[0030] [Embodiment 2] In the embodiment described above, the first pulley 41 and the drive device 50 were provided on the support column 10 on the lower side relative to the lifting platform 20. However, the first pulley 41 and the drive device 50 may also be provided on the support column 10 on the upper side relative to the lifting platform 20. In other words, the second pulley 42 may also be provided on the support column 10 on the lower side relative to the lifting platform 20. In this case as well, the generation of particles in the second pulley 42 will be reduced.

[0031] However, unlike the second pulley 42, the first pulley 41 may generate particles due to wear of the toothed belt 30, similar to conventional article conveying devices. If the first pulley 41 and the drive unit 50 are located above the lifting platform 20, particles generated at the first pulley 41 may fall onto the conveyed object placed on the lifting platform 20. From the viewpoint of reducing the falling of particles onto the conveyed object, it is preferable that the first pulley 41 and the drive unit 50 are located below the lifting platform 20, as described in Embodiment 1.

[0032] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0033] 1. Article conveying device 10 posts 20 Elevating platform 30 Toothed belt 31. First toothed belt 32. Second toothed belt 41. First Pulley 42. Second pulley 50 Drive unit 60 counterweights

Claims

1. A support column with its longitudinal direction as the vertical direction, A lifting platform is provided along the support column so as to be movable in the vertical direction, A toothed belt stretched upward and downward from the lifting platform along the support column, A first pulley is provided on the support column on one side in the vertical direction relative to the lifting platform, and the toothed belt is wound around it. A second pulley is provided on the support column on the other side in the vertical direction relative to the lifting platform, and the toothed belt is wound around it. The system comprises a drive device for rotationally driving the first pulley, The first pulley is a toothed pulley that meshes with the toothed belt, The article conveying device wherein the second pulley is a flat pulley.

2. The article conveying device according to claim 1, wherein the first pulley is provided on the support column on the lower side in the vertical direction relative to the lifting platform.

3. The system further includes a counterweight that moves in the opposite direction to the direction of movement of the lifting platform when the lifting platform moves, The aforementioned toothed belt is A first toothed belt is wrapped around the first pulley to connect the lifting platform and the counterweight, The article conveying device according to claim 1 or 2, further comprising a second toothed belt that is wrapped around the second pulley and connects the lifting platform and the counterweight.

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