Floating transportation device
Screw connections with threaded portions and a fluid passage in the joint between the main and guide members stabilize the levitation conveying device, addressing joint damage and maintaining efficient levitation and conveying performance.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KROSAKI HARIMA CORP
- Filing Date
- 2025-12-08
- Publication Date
- 2026-06-18
AI Technical Summary
Existing levitation conveying devices using porous materials for guide members face issues with joint damage and decreased levitation function due to adhesive deterioration, stress concentration, and fluid leakage, leading to impaired air permeability and reduced conveying efficiency.
The main body and guide members are joined using screw connections with threaded portions, allowing for a gap that serves as a fluid passage, and a fluid supply system to maintain the levitation function, while absorbing thermal expansion differences.
This configuration suppresses joint damage and maintains the levitation conveying function by ensuring stable fluid flow and longevity of the device.
Smart Images
Figure JP2025042651_18062026_PF_FP_ABST
Abstract
Description
Levitation conveying device 【0001】 The present invention relates to a levitation conveying device for levitation-conveying web conveyances. 【0002】 Web conveyance refers to a technology for conveying and storing thin sheet-like products (webs) wound in a roll shape such as films and foils. A web conveyance is a general term for conveyances conveyed by web conveyance. In the technical field of such web conveyance, attempts have been made to levitation-convey web conveyances in order not to damage the web conveyances. As part of this, attempts have been made to apply a porous material to a levitation conveying surface for levitating a web conveyance in a levitation conveying device. 【0003】 When manufacturing a levitation conveying device to which a porous material is applied to the levitation conveying surface, due to mechanical strength and structural problems, a dense material is generally applied to the main body member serving as a base, and a porous material is applied to the guide member including the levitation conveying surface, and the two members are joined and manufactured. For example, Patent Document 1 discloses manufacturing a turn bar corresponding to a levitation conveying device by joining a roll main body corresponding to the main body member and a ring member corresponding to the guide member. 【0004】 As a joining method between the main body member and the guide member, it is common to use an adhesive as disclosed in Patent Document 1 above. However, when an adhesive is used at the joint between the main body member and the guide member in a levitation conveying device to which a porous material is applied to the guide member, the adhesive may deteriorate due to damage caused by the internal pressure when ejecting the fluid for levitation conveying or changes over time, leading to breakage of the joint or a decrease in the levitation conveying function. In addition, the adhesive applied to the joint between the main body member and the guide member and the adhesive protruding from the joint may clog the porous material, possibly impairing the air permeability of the porous material and leading to a decrease in the levitation conveying function. 【0005】On the other hand, there are mechanical joining methods such as bolting, but stress concentrates at the joint, and with long-term use, this may lead to damage to the joint or a decrease in the levitation and conveying function. In addition, leakage from the joint may reduce the flow rate of fluid ejected from the outer surface (levitation and conveying surface) of the porous material, which may also lead to a decrease in the levitation and conveying function. 【0006】 Japanese Patent Publication No. 2023-84291 【0007】 The problem that this invention aims to solve is to suppress damage to the joint between the main body member and the guide member, and to suppress a decrease in the levitation transport function, in a levitation transport device that uses a porous material for the guide member. 【0008】 According to one aspect of the present invention, the following flotation conveying device is provided: A flotation conveying device for flotating and conveying a web conveyed object, comprising a main body member made of a dense material and a guide member made of a porous material, wherein the main body member has a first threaded portion on its outer surface and a fluid introduction portion inside for introducing a fluid for flotation conveying, the guide member has a second threaded portion on its inner surface and a flotation conveying surface on its outer surface for levitating the web conveyed object, the main body member and the guide member are joined by a screw joint between the first threaded portion and the second threaded portion, and further, the main body member has a fluid supply portion that supplies the fluid from the fluid introduction portion to the screw joint formed by the screw joint, the screw joint includes a gap, and the fluid is supplied to the guide member through the gap, the flotation conveying device. 【0009】 According to the present invention, in a levitation conveying device in which a porous material is applied to the guide member, the main body member and the guide member are joined by screw connections, thereby suppressing damage to the joint and a decrease in the levitation conveying function. 【0010】A front view showing a floating conveying device, which is one embodiment of the present invention. A single main body member constituting the floating conveying device of Figure 1 is shown, with (a) being a side view and (b) being a top view. A single guide member constituting the floating conveying device of Figure 1 is shown, with (a) being a side view and (b) being a cross-sectional view along A-A of (a). A cross-sectional view conceptually showing one form of screw connection between the main body member and the guide member. A cross-sectional view conceptually showing another form of screw connection between the main body member and the guide member. A cross-sectional view conceptually showing yet another form of screw connection between the main body member and the guide member. A cross-sectional view conceptually showing yet another form of screw connection between the main body member and the guide member. A cross-sectional view conceptually showing the usage state of the floating conveying device of Figure 1. A cross-sectional view conceptually showing another embodiment of the floating conveying device of the present invention. A cross-sectional view conceptually showing yet another embodiment of the floating conveying device of the present invention. A graph showing the results of measuring the amount of web conveyed using a floating conveying device, which is an embodiment of the present invention. 【0011】 Figure 1 shows a floating conveying device that is one embodiment of the present invention. Figures 2 and 3 show the main body member and guide member that constitute the floating conveying device of Figure 1, respectively, individually. The floating conveying device of this embodiment comprises a main body member 1 and a guide member 2, and optionally a pair of lid members 3. As will be described in detail later, the main body member 1 and the guide member 2 are joined by screw connections. 【0012】The main body member 1 is made of a dense material and has a first threaded portion 11 on its outer surface, as well as a fluid introduction portion 12 inside for introducing a fluid for levitation transport (hereinafter simply referred to as "fluid"). In this embodiment, the first threaded portion 11 is a male thread and is formed along the entire length in the longitudinal direction of the main body member 1. In this embodiment, the fluid introduction portion 12 includes a fluid passage 121 that extends along the central axis in the longitudinal direction of the main body member 1. On the other hand, the guide member 2 is made of a porous material and has a second threaded portion 21 on its inner surface, as well as a levitation transport surface 22 on its outer surface for levitating web transported material. In this embodiment, the second threaded portion 21 is a female thread and is formed along the entire length in the longitudinal direction of the guide member 2. Here, the dense material constituting the main body member 1 can be a metal, a plastic, a ceramic, etc. In addition, the porous material constituting the guide member 2 can be a porous metal, a porous plastic, a porous ceramic, etc. 【0013】 Figure 4A conceptually shows one form of screw connection between the main body member 1 and the guide member 2. As conceptually shown in Figure 4A, the main body member 1 and the guide member 2 are joined by a screw connection between a first threaded portion 11 and a second threaded portion 21. Also, as shown in Figure 4A, the screw connection portion 4 formed by the screw connection between the first threaded portion 11 and the second threaded portion 12 includes a gap 41. This gap 41 is the gap between the threads, which is typically found in screw connections. Depending on the application of the screw connection, the gap may be filled with a sealing material, but in this invention, as described later, the gap 41 is used as a fluid passage. 【0014】Figure 4B conceptually shows another form of screw connection between the main body member 1 and the guide member 2. In this form, the tip of the threads of the first screw portion 11 is notched to increase the size of the gap 41 which serves as a fluid flow path. By adjusting the form of screw connection between the main body member 1 and the guide member 2 in this way, the size of the gap 41 which serves as a fluid flow path can be adjusted, and ultimately the flow rate of the fluid ejected from the floating conveying surface 22 can be adjusted. Here, when notching the tip of the threads as in the form of Figure 4B, it is also possible to notch the tip of the threads of the second screw portion 21 instead of the tip of the threads of the first screw portion 11. However, from the viewpoint of increasing the surface area of the second screw portion 21 formed on the guide member 2, which is made of a porous material, and thereby increasing the flow rate of the fluid ejected from the floating conveying surface 22, it is preferable to notch the tip of the threads of the first screw portion 11 as shown in Figure 4B. 【0015】 Figure 4C conceptually shows another form of screw connection between the main body member 1 and the guide member 2. In this form, by widening the width of the bottom of the thread groove of the first threaded portion 11, the contact area with the second threaded portion 21 becomes smaller, resulting in a fin-like state (the thread becomes thinner). This makes it easier to absorb strain between the main body member 1, which is made of a dense material (e.g., metal), and the guide member 2, which is made of a porous material (e.g., porous ceramics), and can absorb dimensional differences due to thermal expansion. In this way, by adjusting the form of screw connection between the main body member 1 and the guide member 2, it is possible to absorb dimensional differences due to differences in thermal expansion between the main body member 1 and the guide member 2, thereby extending the lifespan. Here, when widening the width of the screw groove bottom as in the configuration of Figure 4C, it is also possible to widen the bottom of the screw groove of the second screw portion 21 instead of the bottom of the screw groove of the first screw portion 11. However, from the viewpoint of increasing the surface area of the second screw portion 21 formed on the guide member 2 made of porous material, and ultimately increasing the flow rate of the fluid ejected from the floating transport surface 22, it is preferable to widen the width of the bottom of the screw groove of the first screw portion 11 as shown in Figure 4C. 【0016】Figure 4D conceptually shows another form of screw connection between the main body member 1 and the guide member 2. In this form, by notching the threads of the first screw portion 11 and widening the width of the bottom of the screw valley, it is possible to widen the gap 41 which serves as a fluid flow path and to absorb the dimensional difference due to thermal expansion between the main body member 1, which is made of a dense material (e.g., metal), and the guide member 2, which is made of a porous material (e.g., porous ceramics). In this way, by adjusting the form of screw connection between the main body member 1 and the guide member 2, it is possible to adjust the flow rate of fluid ejected from the floating conveying surface 22, and a longer lifespan can be expected by absorbing the dimensional difference due to the difference in thermal expansion between the main body member 1 and the guide member 2. Here, when widening the width of the screw groove bottom as shown in Figure 4D, it is also possible to widen the bottom of the screw groove of the second screw portion 21 instead of the bottom of the screw groove of the first screw portion 11. However, from the viewpoint of increasing the surface area of the second screw portion 21 formed on the guide member 2 made of porous material, and ultimately increasing the flow rate of the fluid ejected from the floating transport surface 22, it is preferable to widen the width of the bottom of the screw groove of the first screw portion 11 as shown in Figure 4D. 【0017】 Figure 5 conceptually shows the usage state of the levitation conveying device of this embodiment. As shown in Figure 5 and Figure 2, the main body member 1 further has a fluid supply unit 13 that supplies fluid from the fluid introduction unit 12 to the screw joint 4. In this embodiment, the fluid supply unit 13 is formed to connect the fluid passage 121 and the screw joint 4, and specifically includes a communication hole 131 that connects the fluid passage 121 and the first screw portion 11, and a groove 132 that communicates with the communication hole 131 and is formed along the longitudinal direction of the first screw portion 11. 【0018】In this embodiment, a pair of lid members 3 are joined to both ends of the screw joint (hereinafter simply referred to as the "screw joint") between the main body member 1 and the guide member 2 using adhesive. The pair of lid members 3 are members that close both ends of the screw joint, specifically both ends of the screw joint portion 4 and both ends of the fluid passage 121, and are made of a dense material. One of the lid members 3 has a fluid inlet 31 formed in it to introduce fluid into the fluid introduction portion 12 (fluid passage 121) (see Figure 1), and fluid is introduced through this fluid inlet 31. In this embodiment, the pair of lid members 3 are joined to both ends of the screw joint using adhesive as described above, but they can also be joined to both ends of the screw joint without using adhesive by using, for example, screw screws and a flexible sealing material. In this invention, the pair of lid members 3 are not essential components. That is, in this invention, it is sufficient that they have the function of closing both ends of the screw joint (in this embodiment, both ends of the screw joint portion 4 and both ends of the fluid passage 121), and this function can also be provided in the main body member or the guide member itself. 【0019】 In the above configuration, the fluid introduced into the fluid introduction section 12 (fluid passage 121) via the fluid inlet 31 is supplied to the screw joint section 4 through the fluid supply section 13 (communication hole 131 and groove 132). The fluid supplied to the screw joint section 4 is supplied to the guide member 2 through the gap 41 within the screw joint section 4 and is ejected from the floating conveying surface 22 on its outer surface. As a result, the web conveyed material W is conveyed by floating, as conceptually shown in Figure 5. 【0020】 Figure 5 conceptually illustrates the flow of fluid supplied from the fluid supply unit 13 to the guide member 2 through the screw joint 4 using arrows. Here, reference numeral 5 denotes a coating seal material, which in this embodiment is provided on approximately the lower half of the outer surface of the guide member 2. That is, in this embodiment, the area where the coating seal material 5 is not provided becomes the floating conveying surface 22, and the fluid is ejected from this floating conveying surface 22. Note that the coating seal material 5 is omitted from the illustration in Figures 1 and 3. 【0021】As described above, according to this embodiment, by joining the main body member 1 made of a dense material and the guide member 2 made of a porous material by screw joining, damage to the joint between the main body member 1 and the guide member 2 can be suppressed compared to conventional joining with adhesive or mechanical joining, thereby suppressing a decrease in the levitation transport function. 【0022】 In this embodiment, the main body member 1 and the guide member 2 are cylindrical in shape, but the shapes of the main body member 1 and the guide member 2 are not limited to cylindrical shapes. That is, the shape of the main body member can be any shape having a first threaded portion 11 on its outer surface and a fluid introduction portion 12 inside, and is not necessarily limited to a cylindrical shape depending on the shape of the fluid introduction portion 12, etc. Similarly, the shape of the guide member 2 can be any shape having a second threaded portion 21 on its inner surface and a floating conveying surface 22 on its outer surface, and is not limited to a cylindrical shape. For example, the outer shape of the guide member 2 can be elliptical as shown in Figure 6, or partially circular as shown in Figure 7. Also, as shown in Figure 7, the fluid supply portion 13 can be provided in multiple locations as needed. In Figures 6 and 7, the same reference numerals are used for components that are the same as those in the embodiments shown in Figures 1 to 5. 【0023】 In this embodiment, the first threaded portion 11 and the second threaded portion 21 are formed along the entire length in the longitudinal direction of the main body member 1 and the guide member 2, respectively. However, the first threaded portion 11 and the second threaded portion 21 may be formed partially and the two parts may be partially screw-joined. However, from the viewpoint of screw joint stability and fluid ejection uniformity, it is preferable that the first threaded portion 11 and the second threaded portion 21 are formed along the entire length in the longitudinal direction of the main body member 1 and the guide member 2, respectively. 【0024】As an embodiment of the present invention, a levitation conveying device of the embodiment shown in Figure 1 was prototyped and its levitation conveying function was confirmed. In this embodiment, stainless steel (SUS304) was used for the main body member 1 and the lid member 3, and porous ceramics with wollastonite as the base material were used for the guide member 2. The outer shape of the main body member 1 was 100 mm in diameter and 300 mm in length, and the outer shape of the guide member 2 was 85 mm in diameter and 300 mm in length. The pitch of the first screw portion 11 and the second screw portion 21 was 6 mm (fine thread). 【0025】 As a test to confirm the levitation function of the levitation conveying device of this embodiment, a test was conducted to measure the amount of levitation of the web conveyed material. In this test, a cycloolefin polymer (COP) film with a width of 300 mm and a thickness of 80 μm was used as the web conveyed material, with a tension of 100 N / m and an embrace angle of 180°, and the amount of levitation of the web conveyed material was measured in a stationary state while the fluid (air) supply pressure was varied in the range of 0.2 to 0.5 MPa. The measurement results are shown in Figure 8. As shown in the figure, at all air supply pressures, the web conveyed material levitated almost uniformly along the entire length in the longitudinal direction (width direction of the web conveyed material) of the levitation conveying device. 【0026】 1 Main body member 11 First screw part 12 Fluid introduction part 121 Fluid passage 13 Fluid supply part 131 Communication hole 132 Groove 2 Guide member 21 Second screw part 22 Floating conveying surface 3 Lid member 31 Fluid introduction port 4 Screw joint part 41 Gap 5 Coating seal material W Web conveyed material
Claims
1. A flotation conveying device for levitating and conveying web-carrying materials, comprising a main body member made of a dense material and a guide member made of a porous material, wherein the main body member has a first threaded portion on its outer surface and a fluid introduction portion inside for introducing fluid for levitation conveying, the guide member has a second threaded portion on its inner surface and a levitation conveying surface on its outer surface for levitating web-carrying materials, the main body member and the guide member are joined by a screw joint between the first threaded portion and the second threaded portion, and further, the main body member has a fluid supply portion that supplies the fluid from the fluid introduction portion to the screw joint formed by the screw joint, the screw joint includes a gap, and the fluid is supplied to the guide member through the gap.
2. The levitation conveying device according to claim 1, wherein the first threaded portion is formed over the entire length in the longitudinal direction of the main body member, and the second threaded portion is formed over the entire length in the longitudinal direction of the guide member.
3. The levitation conveying device according to claim 1 or 2, wherein the fluid introduction section includes a fluid passage extending along the longitudinal central axis of the main body member, and the fluid supply section is formed to communicate the fluid passage with the screw joint.
4. The levitation conveying device according to claim 3, wherein the fluid supply section includes a communication hole connecting the fluid passage and the first screw portion, and a groove that communicates with the communication hole and is formed along the longitudinal direction of the first screw portion.