Application aid for applying adhesive used when installing solar panel mounting frames.

Abstract

This helps to suppress variations in the amount and area of ​​adhesive applied by different workers, thereby guaranteeing the quality of installation work on solar panel mounting structures. [Solution] The adhesive application aid used for mounting solar panel frames comprises an outer frame and a section with multiple openings through which the adhesive passes. The opening section has multiple nested annular beam sections and multiple intersecting beam sections connected to the outer frame and intersecting each annular beam section. The multiple openings are formed by through holes in the thickness direction surrounded by the annular beam sections and intersecting beam sections.

Description

Technical Field

[0001] The present disclosure relates to an application aid for applying an adhesive used for attaching a solar panel mount.

Background Art

[0002] It is known to attach a solar power generation module to an object such as a roof of a house via a mount for attaching the solar power generation module. As an example of such a mount, the attachment panel described in Patent Document 1 is adhered and fixed to an object via an adhesive.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When attaching a solar panel mount to an object using an adhesive, it is required to apply an appropriate amount of the adhesive within an appropriate range. However, in the conventional method, there are variations in the amount of adhesive applied and the range of application depending on the operator, and it may be difficult to guarantee the construction quality of the attachment work on the solar panel mount.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one embodiment of the present disclosure, an adhesive application aid is provided for use in the installation of solar panel mounting frames. The adhesive application aid comprises an outer frame and an opening forming section having a plurality of openings through which the adhesive passes. The opening forming section has a plurality of nested annular beam sections and a plurality of intersecting beam sections connected to the outer frame and intersecting each of the annular beam sections. The plurality of openings are formed by through holes in the thickness direction surrounded by the annular beam sections and the intersecting beam sections. With this embodiment of the adhesive application aid, since it has an opening forming section having a plurality of openings through which the adhesive passes, the worker can apply the adhesive to the object by pouring the adhesive into the opening forming section, and variations in the amount and area of ​​adhesive applied by the worker can be suppressed. Therefore, the quality of the installation work on solar panel mounting frames can be guaranteed.

[0007] Furthermore, since the opening-forming section has multiple annular beam sections and multiple intersecting beam sections, each annular beam section and each intersecting beam section forms annular passages and intersecting passages, respectively, in the coated structure which is the adhesive in the applied state. As a result, alcohol-based by-products generated from the coated structure can be discharged to the outside through each annular passage and each intersecting passage. Consequently, the curing time of the coated structure can be shortened, and the installation work of the solar panel mounting frame can be performed efficiently.

[0008] (2) The coating aid of the above form further comprises a central part located in the center of the outer frame and connected to a plurality of the intersecting beams, wherein the central part comprises a central rectangular part having a rectangular shape and a pair of central semicircular parts adjacent to one opposite side of the central rectangular part and connected to the central rectangular part, and the opening forming part comprises a pair of rectangular opening parts adjacent to the other opposite side of the central rectangular part and connected to the central rectangular part, and a pair of semicircular opening parts connected to both of the pair of rectangular opening parts, each having a semicircular shape that surrounds two different central semicircular parts of the pair. With this form of coating aid, since the plurality of intersecting beams are connected to the central part, the strength of the intersecting beams can be increased compared to a configuration in which the central part is not provided. In addition, since the coating aid comprises a central part to which adhesive is not applied, the amount of adhesive used can be reduced while maintaining the adhesive strength of the adhesive.

[0009] (3) In the coating aid of the above form, when a steel plate which is part of the solar panel mounting frame and has a shape corresponding to the shape of the coating structure is attached to the coating structure which is the adhesive in a coated state formed by pouring the adhesive into the opening forming part, the steel plate is provided with a support part located in the center of the steel plate, the support part is provided with a rectangular support part having a rectangular shape, and a pair of semicircular support parts which are adjacent to one opposite side of the rectangular support part and are connected to the rectangular support part, and the steel plate is provided with a pair of rectangular steel plate parts which are adjacent to the other opposite side of the rectangular support part and are connected to the rectangular support part The coating aid comprises a pair of semicircular steel plate portions connected to both of the pair of rectangular steel plate portions, each having a semicircular shape that surrounds two different support semicircular portions from the pair of support semicircular portions, and the coating aid satisfies the following equations (1) to (4), where A mm (millimeters) is the length of the rectangular steel plate portion in the left-right direction, B mm is the radius of the semicircular steel plate portion, C mm is the radius of the support semicircular portion, X mm is the distance between adjacent annular beam portions, Y mm is the width of each annular beam portion, Z mm is the width of each intersecting beam portion, s is the total width of the annular beam portions, t is the total width of the intersecting beam portions, α is the predetermined filling rate of the adhesive required in the coating structure, and π is pi. 1 ≤ Y···(1) 1 ≤ Z···(2) α≦{X / (X+Y)}-[tZ / {2A+π(B+C)}]···(3) s ≤ (BC) / (1 + X) ... (4) With this form of coating aid, the coating aid satisfies the above relational equations (1) to (4), so the coating aid can be designed to satisfy the predetermined filling rate of the adhesive required in the coated structure. Therefore, a coating aid for forming a desired coated structure can be easily designed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a front view showing the overall structure of the coating aid in this embodiment. [Figure 2]This is an explanatory diagram illustrating the process of applying adhesive using the application aid in this embodiment. [Figure 3] This is an explanatory diagram illustrating the installation process of a steel plate that constitutes a part of the solar panel mounting frame in this embodiment. [Modes for carrying out the invention]

[0011] A. Embodiments: Figure 1 is a front view showing the overall structure of the adhesive application aid 100 in this embodiment. The adhesive application aid 100 is used to apply adhesive to an object. The solar panel mounting frame is attached to the object via the applied adhesive. Solar panels are installed on the solar panel mounting frame.

[0012] The objects to which the solar panel mounting frame is attached are not particularly limited and may be any building or structure, such as the roof of a house, a garage, a warehouse, or a storage shed. The material of the coating aid 100 is not particularly limited, but metal is one example. The adhesive used in this embodiment contains a polymer resin such as urethane, ether, or acrylic as its main framework and produces alcohol-based by-products during the curing process. As an example, a moisture-curing adhesive mainly composed of modified silicone resin is used.

[0013] Figure 2 is an explanatory diagram illustrating the process of applying adhesive using the application aid 100 in this embodiment. As shown in Figures 1 and 2, the application aid 100 includes an opening forming section 13. The coated structure 20 is formed when the worker places the application aid 100 on the object and pours the adhesive into the opening forming section 13. Because the adhesive is applied to the object using the application aid 100, variations in the amount and area of ​​adhesive applied by the worker can be suppressed. Furthermore, as will be described later, the application aid 100 is configured to appropriately discharge alcohol-based by-products generated during the curing process of the coated structure 20, thereby shortening the curing time of the coated structure 20.

[0014] The coating aid 100 comprises an outer frame portion 11, a central portion 12, and an opening-forming portion 13. The opening-forming portion 13 also has a plurality of annular beam portions 131 and a plurality of intersecting beam portions 132. The details of each part will be described below. For the sake of explanation, in the coating aid 100 having a rectangular shape, the direction along the long side of the rectangular shape will be called the left-right direction, and the direction along the short side of the rectangular shape will be called the front-back direction. Furthermore, the direction perpendicular to the left-right direction and the front-back direction will be called the up-down direction or thickness direction.

[0015] <Outer frame section 11> The outer frame portion 11 constitutes the outer frame part of the application aid 100. The outer edge of the outer frame portion 11 has a rectangular shape, which matches the shape of the outer edge of the application aid 100. The inner edge of the outer frame portion 11 has an elongated elliptical shape in the left-right direction, which matches the shape of the outer edge of the opening forming portion 13. More specifically, the elongated elliptical shape in the left-right direction is a shape in which semicircles are connected to the right and left sides of a rectangular shape located in the center in the left-right direction. The outer edge of the outer frame portion 11 is composed of a rectangular frame F. The frame F is thicker in the vertical direction than the components of the outer frame portion 11 excluding the frame F. This prevents adhesive from adhering to areas outside the outer frame portion 11 when the worker pours the adhesive into the opening forming portion 13 to apply the adhesive. <Central part 12> The central portion 12 is located in the center of the application aid 100 in both the left-right and front-back directions. The central portion 12 has an elongated elliptical shape in the left-right direction. As described above, the elongated elliptical shape in the left-right direction is a shape in which semicircles are connected to the right and left sides of a rectangular shape located in the center in the left-right direction. As shown in Figure 2, the central portion 12 forms the central region 22 of the application structure 20. Because the central portion 12 is formed in the application aid 100, the central region 22 is configured as a region where adhesive is not applied.

[0016] <Opening forming part 13> The opening forming portion 13 is formed in a region surrounded by the inner edge of the outer frame portion 11 and the outer edge of the central portion 12. The opening forming portion 13 has a plurality of annular beam portions 131 and a plurality of intersecting beam portions 132. Each annular beam portion 131 is provided in a nested manner along the inner edge of the outer frame portion 11 and the outer edge of the central portion 12. Each intersecting beam portion 132 is connected to the outer frame portion 11 and the central portion 12 and intersects each annular beam portion 131. More specifically, each annular beam portion 131 and each intersecting beam portion 132 are orthogonal to each other.

[0017] In the opening forming portion 13, a plurality of first openings H1, a plurality of second openings H2, and a plurality of third openings H3 are provided as openings for the adhesive to pass through. The first opening H1 is surrounded by the inner edge of the outer frame portion 11, the annular beam portion 131 located on the outermost peripheral side, and the intersecting beam portions 132 adjacent to each other. The second opening H2 is surrounded by the annular beam portions 131 adjacent to each other and the intersecting beam portions 132 adjacent to each other. The third opening H3 is surrounded by the outer edge of the central portion 12, the annular beam portion 131 located on the innermost peripheral side, and the intersecting beam portions 132 adjacent to each other. The first opening H1, the second opening H2, and the third opening H3 are each constituted by a through hole in the thickness direction.

[0018] As shown in FIG. 2, the portion where either the annular beam portion 131 or the intersecting beam portion 132 is formed in the opening forming portion 13 is a region where the adhesive is not applied in the coating structure 20. On the other hand, the portion where neither the annular beam portion 131 nor the intersecting beam portion 132 is formed in the opening forming portion 13, that is, the portion where any one of the first opening H1, the second opening H2, or the third opening H3 is provided, is a region where the adhesive is applied in the coating structure 20.

[0019] The annular passage 231 in the coating structure 20 is formed by the annular beam portion 131. Also, the intersecting passage 232 in the coating structure 20 is formed by the intersecting beam portion 132. Since the annular passage 231 is formed in the coating structure 20, alcohol-based by-products generated in the coating structure 20 can be discharged using the annular passage 231. Further, since each intersecting beam portion 132 intersects each annular beam portion 131, each intersecting passage 232 communicates with each annular passage 231. Thereby, the alcohol-based by-products discharged to each annular passage 231 can be discharged to the outside through each intersecting passage 232. Therefore, the curing time of the coating structure 20 can be shortened, and the attachment work of the solar panel mount can be efficiently performed.

[0020] <Installation procedure of solar panel mount> The solar panel mount in the present embodiment is attached to an object by, for example, the following procedure. First, an operator places the coating aid 100 on an object to which a solar panel is to be attached and pours an adhesive into the opening forming portion 13 of the coating aid 100. Next, the upper surface of the coating aid 100 is smoothed with a smoothing plate or the like to remove excess adhesive. Thereby, an appropriate amount of adhesive can be applied to a desired range of the object. When the coating aid 100 is removed from the object, a coating structure 20 as shown in FIG. 2 is formed on the object.

[0021] FIG. 3 is an explanatory diagram for explaining the attachment work of the steel plate 40 that constitutes a part of the solar panel mount in the present embodiment. The steel plate 40 includes a support portion 42 that is convex upward and concave downward at the center in the left-right direction and the front-back direction. Fixing holes R are provided at the left end and the right end of the support portion 42. Note that the central portion 12 of the coating aid 100 is manufactured in accordance with the shape of the outer edge of the support portion 42.

[0022] After removing the coating aid 100 from the object, the worker places the steel plate 40 on the coated structure 20 and waits for the coated structure 20 to harden. As described above, since the coated structure 20 has annular passages 231 and intersecting passages 232, alcohol-based by-products generated from the coated structure 20 can be properly discharged to the outside, and the hardening time of the coated structure 20 can be shortened. Once the coated structure 20 has hardened, the steel plate 40 is fixed on the object. Finally, the solar panel mounting frame is constructed using the steel plate 40 as a base. The worker attaches the components of the solar panel mounting frame other than the steel plate 40 to the steel plate 40 using mechanical means such as screws and bolts through the fixing holes R provided in the steel plate 40.

[0023] Conventional solar panel mounting systems are often fixed to the object by mechanical means, which presents a problem in that it is difficult to install solar panel mounting systems on objects with a large surface area, such as flat roofs, where mechanical fixing is difficult. On the other hand, with the method described above, even on objects with a large surface area, such as flat roofs, where mechanical fixing is difficult, solar panel mounting systems can be easily and securely attached to the object by using the coating aid 100 and adhesive.

[0024] Next, the detailed shapes of the coating aid 100 and the steel plate 40 will be described. As shown in Figure 1, the central part 12 located in the center of the coating aid 100 has a central rectangular part 12D and a pair of central semicircular parts 12C. The central rectangular part 12D has a rectangular shape. The pair of central semicircular parts 12C are adjacent to one opposite side of the central rectangular part 12D, i.e., the left and right sides of the central rectangular part 12D, respectively, and have a semicircular shape that is connected to the central rectangular part 12D. The opening forming part 13 has a pair of opening rectangular parts 13A and a pair of opening semicircular parts 13B. The pair of opening rectangular parts 13A are adjacent to the other opposite side of the central rectangular part 12D, i.e., the front and rear sides of the central rectangular part 12D, respectively, and have a rectangular shape that is connected to the central rectangular part 12D. The pair of semicircular openings 13B are connected to both the left and right sides of the pair of rectangular openings 13A and have a semicircular shape that surrounds two different central semicircular openings 12C of the pair.

[0025] The length A1 in the left-right direction of the rectangular opening section 13A is 80.0 mm, and the radius B1 of the semicircular opening section 13B is 81.5 mm. The spacing X between adjacent annular beam sections 131 is 5.0 mm, the width Y of each annular beam section 131 is 1.5 mm, and the width Z of each intersecting beam section is 3.0 mm. The length in the left-right direction of the central rectangular section 12D is equal to the length A1 in the left-right direction of the rectangular opening section 13A. The radius C1 of the central semicircular section 12C is 19.0 mm. In addition, the thickness in the vertical direction of the outer frame section 11, excluding frame F, is 1.0 mm. Note that the above dimensions are merely examples and can be appropriately changed according to the usage of the coating aid 100.

[0026] As shown in Figure 3, the support portion 42 located in the center of the steel plate 40 has a support rectangular portion 42D and a pair of support semicircular portions 42C. The support rectangular portion 42D has a rectangular shape. The pair of support semicircular portions 42C are adjacent to one opposite side of the support rectangular portion 42D, i.e., the left and right sides of the support rectangular portion 42D, respectively, and have a semicircular shape that connects with the support rectangular portion 42D. The steel plate 40 also has a pair of steel plate rectangular portions 40A and a pair of steel plate semicircular portions 40B. The pair of steel plate rectangular portions 40A are adjacent to the other opposite side of the support rectangular portion 42D, i.e., the front and rear sides of the support rectangular portion 42D, respectively, and have a rectangular shape that connects with the support rectangular portion 42D. The pair of steel plate semicircular portions 40B are connected to both the left and right sides of the pair of steel plate rectangular portions 40A, and have a semicircular shape that surrounds the different support semicircular portions 42C of the pair of steel plate rectangular portions 40A.

[0027] The length A in the left-right direction of the rectangular steel plate section 40A is 80.0 mm, which is equal to the length A1 in the left-right direction of the rectangular opening section 13A. The radius B of the semicircular steel plate section 40B is 83.0 mm. The length in the left-right direction of the support rectangular section 42D is equal to the length A in the left-right direction of the rectangular steel plate section 40A. The radius C of the support semicircular section 42C is 17.5 mm. Note that the above dimensions are merely examples and can be appropriately changed according to the usage of the solar panel mounting system.

[0028] The dimensions of the coating aid 100 can be experimentally determined from the desired adhesive strength and curing time of the coated structure 20 to be formed. The following describes the considerations when setting the dimensions of the coating aid 100. First, in order to discharge alcohol-based by-products generated from the coated structure 20 to the outside, the width of the annular passage 231 and the intersecting passage 232 must be 1 mm or more. From this viewpoint, the following inequality holds for the width Y mm of the annular beam section 131 and the width Z mm of the intersecting beam section 132. 1 ≤ Y···(1) 1 ≤ Z···(2)

[0029] Furthermore, if we denote the required adhesive filling rate, which is a predetermined filling rate of the adhesive required in the coated structure 20, as α, and the total adhesiveable area of ​​the steel plate 40 as Sall, and the actual adhesive area as Sglue, then the following inequality must be satisfied. Sglue≧αSall···(i) Here, Sall corresponds to the total area of ​​the steel plate 40 excluding the support portion 42, and if we let pi be π, it can be defined by the following formula. Sall=2A(BC)+π(B^2-C^2)···(ii) Furthermore, since the steel plate 40 has a shape corresponding to the shape of the coating structure 20, Sglue corresponds to the area of ​​the portion of the coating structure 20 to which the adhesive is applied, that is, the area of ​​the portion of the coating aid 100 in which one of the first opening H1, the second opening H2, or the third opening H3 is provided. Therefore, if the total number of intersecting beam portions 132 in the coating aid 100 is t, Sglue can be defined by the following formula. Sglue={X / (X+Y)}×{2A(BC)+π(B^2-C^2)}-tZ(BC)...(iii) From equations (i), (ii), and (iii) above, the following inequalities hold. α≦{X / (X+Y)}-[tZ / {2A+π(B+C)}]···(3)

[0030] Furthermore, if the total number of annular beam portions 131 in the coating aid 100 is s, then s can be expressed by the following formula. s(X+Y)=BC···(iv) From equations (1) and (iv), the following inequality holds: s ≤ (BC) / (1 + X) ... (4) Based on the above, the coating aid 100 can be designed to satisfy the above relational equations (1) to (4) when forming the desired coated structure 20. The dimensions of the coating aid 100 may be appropriately changed depending on the type of adhesive, the material of the steel plate 40, the material and surface condition of the object, or the working environment such as the temperature and humidity when the steel plate 40 is installed.

[0031] As described above, the application aid 100 used for installing solar panels is equipped with an opening-forming section 13 having a first opening H1, a second opening H2, and a third opening H3 for the adhesive to pass through. Therefore, the worker can apply the adhesive to the object by pouring it into the opening-forming section 13, and variations in the amount and area of ​​adhesive applied by the worker can be suppressed. This ensures the quality of the installation work on the solar panel mounting frame.

[0032] Furthermore, since the opening forming section 13 has a plurality of annular beam sections 131 and a plurality of intersecting beam sections 132, each annular beam section 131 and each intersecting beam section 132 forms annular passages 231 and intersecting passages 232, respectively, in the coated structure 20, where adhesive is not applied. As a result, alcohol-based by-products generated from the coated structure 20 can be discharged to the outside through each annular passage 231 and each intersecting passage 232 that intersects with each annular passage 231. Therefore, the curing time of the coated structure 20 can be shortened, and the installation work of the solar panel mounting frame can be performed efficiently.

[0033] Furthermore, since the multiple intersecting beam sections 132 are connected to the central section 12, the strength of the intersecting beam sections 132 can be increased compared to a configuration without a central section 12. In addition, since the application aid 100 has a central section 12 to which adhesive is not applied, the amount of adhesive used can be reduced while maintaining the adhesive strength of the adhesive.

[0034] Furthermore, since the coating aid 100 satisfies the above relational equations (1) to (4), the coating aid 100 can be designed to satisfy the required adhesive filling rate α in the coated structure 20. Therefore, the coating aid 100 for forming the desired coated structure 20 can be easily designed.

[0035] B. Other embodiments: (B1) In this embodiment, the coating aid 100 was provided with a central portion 12 having an elongated elliptical shape in the left-right direction, but the disclosure is not limited thereto. Since the support portion 42 in the steel plate 40 in this embodiment is a portion that is not fixed by adhesive, the central portion 12 of the coating aid 100 was manufactured to match the shape of the support portion 42. Therefore, the shape of the central portion 12 can be appropriately changed to match the shape of the support portion 42. In addition, the central portion 12 of the coating aid 100 may be omitted. In this case, the multiple openings in the opening forming portion 13 may consist of a first opening H1 surrounded by the inner edge of the outer frame portion 11, the annular beam portion 131 located on the outermost periphery, and the mutually adjacent intersecting beam portions 132, and a second opening H2 surrounded by the mutually adjacent annular beam portions 131 and the mutually adjacent intersecting beam portions 132.

[0036] (B2) In this embodiment, the dimensions of the opening-forming portion 13 have been described, but the disclosure is not limited thereto. For example, the opening-forming portion 13 does not have to have an elongated elliptical shape in the left-right direction, and may have other shapes such as a perfect circle or a rectangle. Also, although each annular beam portion 131 and each intersecting beam portion 132 were orthogonal to each other, instead, each annular beam portion 131 and each intersecting beam portion 132 may be configured to intersect at any angle other than 90 degrees.

[0037] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of Symbols]

[0038] 100... Coating aid, 11... Outer frame, 12... Central section, 12C... Central semicircular section, 12D... Central rectangular section, 13... Opening forming section, 13A... Opening rectangular section, 13B... Opening semicircular section, 131... Annular beam section, 132... Intersecting beam section, 20... Coating structure, 22... Central region, 231... Annular passage, 232... Intersecting passage, 40... Steel plate, 40A... Steel plate rectangular section, 40B... Steel plate semicircular section, 42... Support section, 42C... Support semicircular section, 42D... Support rectangular section, F... Frame, H1... First opening, H2... Second opening, H3... Third opening, R... Fixing hole

Claims

1. An adhesive application aid used for attaching solar panel mounting frames, Outer frame and, The device comprises an opening-forming section having a plurality of openings through which the adhesive passes, The opening forming section comprises a plurality of nested annular beam sections and a plurality of intersecting beam sections that are connected to the outer frame and intersect each of the annular beam sections. The coating aid is characterized in that the plurality of openings are formed by through holes in the thickness direction surrounded by the annular beam portion and the intersecting beam portion.

2. The coating aid according to claim 1, The outer frame portion is located in the center and further comprises a central portion that connects to a plurality of the aforementioned intersecting beam portions, The aforementioned central part is, A central rectangular section having a rectangular shape, It has a pair of central semicircular portions adjacent to one opposite side of the central rectangular portion and connected to the central rectangular portion, The aforementioned opening forming portion is A pair of rectangular openings adjacent to the other opposite side of the central rectangular portion and having a rectangular shape connected to the central rectangular portion, A coating aid comprising: a pair of semicircular openings connected to both of the pair of rectangular openings, each having a semicircular shape that surrounds two different central semicircular openings from the pair of central semicircular openings.

3. The coating aid according to claim 2, When attaching a steel plate, which is part of the solar panel mounting frame and has a shape corresponding to the shape of the coated structure, to a coated structure which is the adhesive in a coated state formed by pouring the adhesive into the opening forming portion, The aforementioned steel plate is The steel plate is equipped with a support portion located in the center, The aforementioned support portion is A rectangular support portion having a rectangular shape, It has a pair of semicircular support portions adjacent to one opposite side of the rectangular support portion and connected to the rectangular support portion, The aforementioned steel plate is A pair of rectangular steel plate sections, each adjacent to the other opposite side of the support rectangular section and having a rectangular shape connected to the support rectangular section, A pair of semicircular steel plate portions connected to both of the pair of rectangular steel plate portions, each having a semicircular shape that surrounds two different support semicircular portions of the pair, The coating aid satisfies the following equations (1) to (4), where A mm (millimeters) is the length of the rectangular steel plate section in the left-right direction, B mm is the radius of the semicircular steel plate section, C mm is the radius of the supporting semicircular section, X mm is the distance between adjacent annular beam sections, Y mm is the width of each annular beam section, Z mm is the width of each intersecting beam section, s is the total width of the annular beam sections, t is the total width of the intersecting beam sections, α is the predetermined filling rate of the adhesive required in the coating structure, and π is pi. 1 ≤ Y ... (1) 1 ≤ Z ... (2) α≦{X / (X+Y)}-[tZ / {2A+π(B+C)}]...(3) s≦(B-C) / (1+X)...(4)

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