Water-expandable sheet mounting device

Abstract

To attach a water-inflatable sheet in a state of being tightly aligned with an inner surface of a pipe body, such as a pipe joint, while maintaining a simple configuration.SOLUTION: A pair of pressurizing dies 31 for pressurizing a water-inflatable sheet 5 temporarily affixed over the entire circumference of an inner surface 56 of a square cylinder section 51 to a side of the inner surface 56 are oppositely arranged with pressurizing surfaces 34 in an opposing posture with a tube axis Sa therebetween. The pair of pressurizing dies 31 are configured to pressurize a corner 57a on one diagonal 51Xa and a corner 57b on the other diagonal 51Xb while changing the posture around the tube axis. A sum (La+Lb) of lengths of sheet pressurizing portions 81a and 81b, which are pressurized by the pair of pressurizing dies 31 on an inter-corner apex portion 80 before and after the posture change, is set shorter than a length LA between the corner apexes of the inter-corner apex portion 80 in any inter-corner apex portion 80 in the inner surface 56 of the square cylinder section 51 in plan view.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a water-swellable sheet attaching apparatus for attaching a water-swellable sheet to an inner circumferential surface of a pipe material such as a pipe joint for connecting pipe bodies used for protecting, for example, electric wires and cables by pressurization. Background Art

[0002] Conventionally, pipe bodies are used to protect electric wires, cables and the like when they are buried underground. Pipe joints are used for connecting such pipe bodies, and it is necessary to ensure waterproof performance at the connection between the pipe body and the pipe joint.

[0003] For example, when the connection between a pipe body and a pipe joint is a connection mode in which the pipe body is inserted into the pipe joint for connection, a water-swellable sheet is attached in advance to the inner circumferential surface of the insertion portion of the pipe body in the pipe joint. Then, the water-absorbent swellable nonwoven fabric interposed at the mutual connection portion absorbs moisture in the ground and expands, thereby closing gaps generated at the connection portion and ensuring good water stopping performance.

[0004] The water-swellable sheet needs to be firmly attached to the inner circumferential surface of a pipe material such as a pipe joint so as not to peel off when the pipe body is inserted into the pipe joint. For example, Patent Document 1 proposes a technique for this purpose.

[0005] The apparatus of Patent Document 1 is configured such that an inner mold composed of a plurality of divided die pieces is pressed against the water-swellable sheet in several times in order to accurately attach the water-swellable sheet temporarily attached to the entire circumference of the inner circumferential surface while closely aligning it along the inner circumferential surface. Furthermore, the apparatus of Patent Document 1 is configured such that, when pressing is performed by the inner mold each time, the pressing portions each time are shifted in the circumferential direction along the inner circumferential surface of the square cylindrical portion, while ends of the pressing portions overlap each other.

[0006] However, attempting to overlap the ends of the pressed areas with a small number of presses necessitates ensuring sufficient length of the pressed area per press by the internal mold in the circumferential direction of the inner surface, which may lead to an increase in the size of the internal mold.

[0007] In that case, when pressing the inner mold multiple times, if you try to slide the inner mold circumferentially along the inner surface while it is still inserted inside the rectangular tubular section after pressing it against the water-expandable sheet, there is a high risk that the inner mold will interfere with the water-expandable sheet temporarily attached to the inner surface of the rectangular tubular section, causing the water-expandable sheet to peel off.

[0008] Therefore, in the apparatus described in Patent Document 1, for example, each time the inner mold is pressed against the water-expandable sheet in several stages, the inner mold is temporarily removed from the inside of the rectangular tubular section, and then reinserted into the inside of the tubular section in a position corresponding to the next pressing.

[0009] In other words, the apparatus described in Patent Document 1, for example, would require a configuration to rotate the inner mold while it is removed from the inside of the rectangular tubular section, or to replace it with a different inner mold, when changing the position of the inner mold to one that corresponds to the next pressing operation, which could result in a complex configuration. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 5136898 [Overview of the project] [Problems that the invention aims to solve]

[0011] The present invention aims to provide a water-expandable sheet mounting device that, despite its simple configuration, can securely attach a water-expandable sheet to the inner circumferential surface of a pipe, such as a pipe joint, while maintaining a precise fit. [Means for solving the problem]

[0012] This invention relates to a water-expandable sheet mounting device comprising a pressure type for applying pressure to a water-expandable sheet temporarily attached to the entire circumference of the inner surface of a square-shaped rectangular tube portion of a pipe material toward the inner surface, and a radial movement means for moving the pressure type radially so as to be able to move away from or apply pressure to the inner surface, wherein the pressure type is provided with a pair of pressure types, each having a convex pressure surface formed corresponding to the corners in the circumferential direction of the inner surface so as to be able to apply pressure to the corners, and the pressure surfaces are arranged facing each other in opposite positions across the pipe axis, and the device is provided with a circumferential movement means for relatively rotating at least one of the pipe material and the pressure type around the pipe axis within a range where the arrangement direction of the pair of pressure types coincides with either one diagonal or the other diagonal, and the sum of the length of the portion pressed before the relative rotation and the length of the portion pressed after the relative rotation of the portion between adjacent corners in the circumferential direction of the inner surface of the rectangular tube portion is set to be shorter than the length of the portion between the corners The pair of pressurized molds, when in their closest proximity to each other, have a maximum diameter in plan view that is shorter than the length of one side of the inner circumferential surface minus the thickness equivalent to the water-expandable sheet temporarily attached to the entire circumference of the inner circumferential surface. The pipe mounting member has a mounting surface on which the periphery of the opening of the rectangular tube portion is placed so that the pipe material can be supported in a position where the opening of the rectangular tube portion faces downward. The pressurized mold support member protrudes upward from the mounting surface so that it can be inserted into the interior of the rectangular tube portion placed on the mounting surface through the opening, and supports the pressurized mold from below at the same height as the water-expandable sheet temporarily attached to the inner circumferential surface. It is characterized by the following:

[0013] According to the above configuration, the pair of pressurized elements can be made more compact, allowing them to rotate relative to each other while remaining inserted inside the rectangular tube without having to remove and reinsert them when rotating relative to each other around the tube axis. Therefore, the hassle of removing and reinserting the pair of pressurized elements into the rectangular tube, and the need for such a configuration, can be eliminated, resulting in a simpler design.

[0014] Furthermore, when the pressurizing type pressurizes the corners on the inner surface of the rectangular tube, the water-expandable sheet can be firmly pressed against the inner surface of the corner by the convex pressurizing surface of the pressurizing type, conforming to the shape of the inner surface of the corner. In addition, even if there are areas between adjacent corners in the circumferential direction of the inner surface where the water-expandable sheet is not pressed by the pressurizing type (referred to as "unpressurized sheet areas"), as the water-expandable sheet is pressed against the inner surface of the corner by the pressurizing type as described above, the unpressurized sheet areas are pulled towards the corners along the inner surface. As a result, the water-expandable sheet can be installed in a state that conforms to the inner surface without leaving any loose areas or gaps between it and the inner surface.

[0015] In other words, the present invention is configured to pressurize the four corners on the inner surface of the rectangular tube by pressurizing with a small number of pressurization cycles (for example, two cycles) using a compact pair of pressurized types, so that the water-swellable sheet can be aligned along the entire inner surface, including the unpressurized portion of the sheet. Therefore, despite its simple configuration, the present invention allows for the attachment of a water-expandable sheet to the inner circumferential surface of a pipe, such as a pipe joint, in a state where it conforms tightly to the surface.

[0016] Also, as mentioned above The pair of pressurized types described above, when in their closest proximity to each other, have a maximum diameter in plan view that is shorter than the length of one side of the inner circumferential surface minus the thickness equivalent to the water-expandable sheet temporarily attached around the entire circumference of the inner circumferential surface. There are .

[0017] With the above configuration, the pair of pressure molds do not interfere with the water-expandable sheet temporarily attached to the inner surface of the rectangular tube, and the pair of pressure molds can be reliably rotated relative to each other around the tube axis while inserted inside the rectangular tube. Therefore, when the pair of pressure molds are rotated relative to each other, the water-expandable sheet does not peel off from the inner surface.

[0018] Also, as mentioned abovea pipe placement member having a placement surface on which a peripheral edge of the opening of the square cylindrical portion is placed so that the pipe material can be supported in a posture where the opening of the square cylindrical portion faces downward; and a pressurized mold support member that protrudes upward from the placement surface so as to be insertable into the interior of the square cylindrical portion placed on the placement surface through the opening, and supports the pressurized mold from below at the same height as the water-swellable sheet temporarily attached to the inner peripheral surface There are .

[0019] According to the above configuration, only by placing the pipe material on the placement surface, the pressurized mold together with the pressurized mold support member can be inserted into the interior of the square cylindrical portion, and inside the square cylindrical portion, the water-swellable sheet temporarily fixed to the inner peripheral surface and the pressurized mold can be set at the same height.

[0020] As an aspect of the present invention, a configuration may be adopted in which the placement surface is provided with a regulating portion that protrudes upward so as to be able to abut against the peripheral edge of the opening of the square cylindrical portion placed on the placement surface and regulates the pipe material in the radial direction.

[0021] According to the above configuration, only by placing the pipe material on the placement surface, the regulating portion protruding upward from the placement surface abuts against the inner edge of the opening of the square cylindrical portion, so that the relative position of the pipe material in the radial direction with respect to the pressurized mold can be regulated.

[0022] As an aspect of the present invention, an outer support member that supports the square cylindrical portion from the outside in a plan view may be provided, and an outer support member moving means that moves the outer support member in the radial direction so as to be able to separate from or abut against the square cylindrical portion may be provided.

[0023] According to the above configuration, the pipe material can be easily placed on or removed from the placement surface while the pipe material is firmly supported from the outside by the outer support member.

[0024] Further, according to an aspect of the present invention, a pair of said outer support members are provided so as to be capable of being disposed facing each other on each side across said rectangular tubular portion on either one of said pair of diagonal lines, and both of said pair of outer support members are formed to protrude along the outer peripheral surface of said rectangular tubular portion to each side across said rectangular tubular portion on the other diagonal line, and the protruding direction tips of each of said pair of outer support members may be configured to coincide with the pressing surfaces of said pair of pressing dies disposed on said other diagonal line in the circumferential direction of said rectangular tubular portion.

[0025] According to the above configuration, when pressing the corner portion on one diagonal line in a state where the pair of pressing dies are arranged on one diagonal line, and when pressing the corner portion on the other diagonal line in a state where the pair of pressing dies are arranged on the other diagonal line, the pair of outer support members can support the rectangular tubular portion from the outside while maintaining the same posture and position in both cases. Accordingly, the configuration of the water-swellable sheet attaching apparatus and the sheet attaching procedure can be further simplified.

Effects of the Invention

[0026] According to the present invention, a water-swellable sheet can be attached in a state of being perfectly aligned along the inner peripheral surface of a pipe body such as a pipe joint while having a simple configuration.

Brief Description of Drawings

[0027] [Figure 1] A perspective view showing essential parts of a square pipe, a male joint, and a female joint. [Figure 2] A partial cross-sectional side view showing a connected state of a square pipe to a female joint via a male joint. [Figure 3] A perspective view of the water-swellable sheet attaching apparatus according to the present embodiment. [Figure 4] A perspective view of Fig. 3 with a pipe placing member and an outer supporting means omitted. [Figure 5] A plan view showing essential parts of the water-swellable sheet attaching apparatus according to the present embodiment. [Figure 6] A right side view of the water-swellable sheet attaching apparatus according to the present embodiment, wherein the outer supporting means is shown by imaginary lines. [Figure 7] A cross-sectional view showing the main part along line AA in Figure 6 during the external support process of the water-swellable sheet mounting device of this embodiment. [Figure 8] This is a cross-sectional view taken during the first pressurization process. [Figure 9] This is a cross-sectional view after the pressurized posture change process has been executed. [Figure 10] This is a cross-sectional view taken during the second pressurization process. [Figure 11] A schematic cross-sectional view of a rectangular tube section in the direction of the tube axis, showing the relationship between the length of the portion between the corner vertices of the inner circumference and the length of the pressurized portion due to the pressurizing type. [Figure 12] A cross-sectional view in the axial direction of a rectangular tube section with a water-expandable sheet attached to its inner surface. [Modes for carrying out the invention]

[0028] One embodiment of this invention will be described below with reference to the drawings.

[0029] The water-expandable sheet mounting device 1 of this embodiment is a device that presses a water-expandable sheet 5 for water sealing onto the inner circumferential surface 56 of a plug-in joint 50, as shown in Figure 1. Prior to describing the water-expandable sheet mounting device 1, an example of the configuration and application of the insert fitting 50 will be explained.

[0030] As shown in Figures 1 and 2, the push-in fitting 50 is a pipe fitting that connects a rectangular pipe 60, which is used to insert and protect electrical wires and cables buried underground, to a receiving fitting 70 that is connected and fixed to a round hole in a handhole (not shown).

[0031] The rectangular pipe 60 has a pipe wall in which circular sections 61, which have a circular cross-section perpendicular to the pipe axis Y (hereinafter referred to as the "orthogonal cross-section"), and rectangular sections 62, which are larger in size than the circular sections 61 and have a roughly square cross-section (roughly square in this example), are alternately arranged in the pipe axis Y direction. In this embodiment, at one end Ya in the pipe axis Y direction of the rectangular pipe 60, the circular section 61 is located among the rectangular section 62 and the circular section 61.

[0032] One side Ya of the rectangular pipe 60 in the pipe axis direction Y is formed as a insertable cylindrical portion 63 that is inserted into and connected to the inside of the insert fitting 50. In this embodiment, the insertable cylindrical portion 63 of the rectangular pipe 60 has two adjacent circular portions 61 in the pipe axis direction Y and two adjacent rectangular portions 62 in the pipe axis direction Y.

[0033] One side Ya of the receiving joint 70 in the pipe axis direction Y is screwed into a round hole formed in the side wall of the handhole (not shown in the figure). On the other hand, the other side Yb of the receiving joint 70 in the pipe axis direction Y protrudes outward from the side wall of the handhole and is formed as a insertion cylinder portion 72 into which the insertion joint 50 is inserted and connected. An annular retaining ring 73 that elastically deforms in the direction of diameter expansion is attached to the inner circumferential surface of the insertion tube portion 72 of the receiving joint 70 in the middle of the pipe axis direction Y.

[0034] As shown in Figures 1 and 2, the push-in fitting 50 is integrally formed by resin molding, consisting of a rectangular tube portion 51 as a female connector and a cylindrical portion 52 as a male connector. The rectangular tube portion 51 of the push-in fitting 50 is into which the insertable tube portion 63 of the rectangular pipe 60 is inserted, while the cylindrical portion 52 of the push-in fitting 50 is into which the insertable tube portion 72 of the receiving fitting 70 is inserted. In this way, the rectangular pipe 60 and the receiving fitting 70 are connected via the push-in fitting 50.

[0035] The rectangular tube section 51 and the cylindrical section 52 are coaxial with each other along their respective pipe axes Sa and are arranged continuously in the pipe axis direction Y. The cylindrical section 52 has a circular cross-section, while the rectangular tube section 51 has a roughly angular cross-section (roughly square in this example) and one side is larger than the outer diameter of the cylindrical section 52. A stepped surface 53 is formed between the rectangular tube section 51 and the cylindrical section 52, as shown in Figure 2.

[0036] The inner circumferential surface 56 of the rectangular tube portion 51 is equipped with a displacement plate 54 that is elastically displaceable both internally and externally, corresponding to the midpoint in the pipe axis direction Y. Furthermore, a locking projection 55 is formed on the inner surface of the displacement plate 54, projecting inward to prevent the insertion portion 63 of the rectangular tube 60 inserted into the rectangular tube portion 51 from coming loose.

[0037] When the insertion portion 63 of the rectangular tube 60 is inserted into the rectangular tube portion 51, the locking projection 55 is pressed against the rectangular portion 62 of the rectangular tube 60, causing the displacement plate 54 to elastically deform outward. The displacement plate 54 then elastically returns to its original position once the tip of the rectangular portion 62 has passed. As a result, as shown in Figure 2, the locking projection 55 fits into the circular portion 61, preventing the tip of the rectangular portion 62 of the insertion portion 63 from coming loose from the side opposite to the insertion direction.

[0038] A water-expandable sheet 5 is provided inside the rectangular tube portion 51 in the area behind the locking projection 55 and the displacement plate 54. The water-expandable sheet 5 is attached adjacent to the stepped surface 53 along the entire circumference of the inner circumferential surface 56 of the rectangular tube portion 51, in the area behind it.

[0039] The cylindrical portion 52 is the part that is inserted into the insertion cylinder portion 72 of the receiving joint 70, and the outer circumferential surface of the cylindrical portion 52 is also covered with a water-expandable sheet 6. On the outer circumferential surface of the cylindrical portion 52 on one side Ya in the pipe axis direction Y from the water-expandable sheet 6, a groove 59 is formed in which the aforementioned retaining ring 73 of the receiving joint 70 engages.

[0040] The aforementioned water-swellable sheets 5 and 6 expand when they absorb moisture, and can be obtained, for example, by incorporating a water-swellable material that expands when it absorbs moisture into a nonwoven fabric. The water-swellable material can be in the form of powder, granules, sheets, or liquids, but using a fibrous material is preferable because it enhances the integration with the fibers that make up the nonwoven fabric. The water-swellable sheets 5 and 6 may also be composed of materials other than water-swellable nonwoven fabrics.

[0041] When the insertable cylindrical portion 63 of the rectangular pipe 60 is inserted into the rectangular cylindrical portion 51 of the insert fitting 50, the circular portion 61 located at the furthest Ya of the three circular portions 61 of the insertable cylindrical portion 63 is inserted beyond the stepped surface 53 of the insert fitting 50 and into the base of the cylindrical portion 52, as shown in Figure 2. Furthermore, of the two rectangular portions 62 of the insertable cylindrical portion 63, the rectangular portion 62 located at the furthest Ya of the two rectangular portions 63 is in contact with the water-expandable sheet 5 from the inside of the diameter.

[0042] In other words, when the insert fitting 50 and the rectangular pipe 60 are connected, a water-swellable sheet 5 is interposed between the inner circumferential surface 56 of the rectangular tube portion 51 and the outer circumferential surface of the insertable tube portion 63 of the rectangular pipe 60 (specifically, the rectangular portion 62 located at the far right Ya). On the other hand, when the insert fitting 50 and the receiving fitting 70 are connected, a water-swellable sheet 6 is interposed between the outer surface of the cylindrical portion 52 and the inner surface of the insert cylindrical portion 72 of the receiving fitting 70.

[0043] As a result, even if water tries to penetrate the interior from the connection point between the insert fitting 50 and the square pipe 60, or from the connection point between the insert fitting 50 and the receiving fitting 70, the water-swellable sheets 5 and 6 absorb the water and expand, ensuring watertightness between them.

[0044] The following describes the water-swellable sheet mounting device 1 of this embodiment. The water-expandable sheet mounting device 1 of this embodiment is a device that attaches a water-expandable sheet 5, which has been temporarily attached to the entire circumference of the inner circumferential surface 56 of the rectangular tube portion 51 of the insert joint 50, to the inner circumferential surface 56 by pressurizing it, and as shown in Figures 3, 4, and 6, it comprises a base 2 and a device body 3 mounted on the upper surface of the base 2.

[0045] Here, the water-swellable sheet 5 is formed in a strip shape with a length slightly longer than the length corresponding to the entire circumference of the inner circumferential surface 56 of the rectangular tube portion 51 of the insert fitting 50. It is assumed that such a strip-shaped water-swellable sheet 5 is temporarily attached to the entire circumference of the inner circumferential surface 56 of the rectangular tube portion 51 of the insert fitting 50. Specifically, the water-swellable sheet 5 has one side as the adhesive surface, with one side of double-sided tape attached to the entire surface of that side. By pressing the adhesive surface of the water-swellable sheet 5 onto the attachment point on the inner circumferential surface 56 of the rectangular tube portion 51, from one end in the longitudinal direction to the other, along the circumferential direction of the inner circumferential surface 56, the water-swellable sheet 5 can be temporarily attached over the entire circumference of the inner circumferential surface 56.

[0046] As shown in Figures 3 to 6, the main body 3 of the water-expandable sheet mounting device 1 includes a circumferential moving means 10, a pipe mounting member 20, an internal pressurizing means 30, and an external support means 40.

[0047] The circumferential moving means 10 is a means for rotating the pressurized type 31, which is provided in the internal pressurizing means 30 described later, around the pipe axis Sa inside the insert joint 50, and comprises a base portion 19, a turntable 11, and a turntable drive structure 12.

[0048] The base portion 19 is formed in a disc shape and is fixed in a horizontal position with its thickness direction coinciding with the vertical direction, with its lower surface resting on the upper surface of the base 2. The rotating base 11 is mounted on top of the base portion 19 in a horizontal position with its thickness direction coinciding with the vertical direction, and is pivotally supported on the base portion 19 so as to be rotatable around a rotation axis Sb that extends in a direction coinciding with the vertical direction.

[0049] The turntable drive structure 12 comprises a cylinder body 14 and a pneumatic cylinder 13 having a piston rod 15 (see Figures 3 and 4) that extends and retracts axially relative to the cylinder body 14. The pneumatic cylinder 13 has its cylinder body 14 pivotally attached to the base 2, and the tip of the piston rod 15 pivotally attached to a part of the outer surface of the turntable 11 in the circumferential direction. The pneumatic cylinder 13 rotates the turntable 11 clockwise or counterclockwise around the rotation axis Sb within an angular range of at least 90 degrees in a plan view as the piston rod 15 extends and retracts.

[0050] As shown in Figures 5 and 6, a pair of pipe support members 20 are provided so as to be able to support the insert fitting 50 from below, facing each other across the rotation axis Sb of the turntable 11. More specifically, as shown in Figures 3, 5, and 6, the pipe mounting member 20 comprises a support column 21 erected from the upper surface of the base 2 above the upper surface 11a of the turntable 11, and an extension piece 22 supported by the support column 21 and extending horizontally from the upper end of the support column 21 toward the rotation axis Sb. In a plan view, the tips of the pair of extension pieces 22 in their respective extension directions face each other on each side separated by a pressurized support member 33, which will be described later, and the distance between the tips in their respective extension directions is shorter than the lengths of the diagonals 51Xa and 51Xb of the rectangular tube portion 51 of the insert joint 50.

[0051] The upper surfaces of each extension piece 22 of the pair of pipe mounting members 20 are both formed flat and horizontally as mounting surfaces 23 on which the insert fitting 50 is placed. The pair of mounting surfaces 23 are formed at the same height and are both located above the upper surface 11a of the turntable 11.

[0052] As described above, the pair of pipe mounting members 20 support the insert fitting 50, which is positioned above the upper surface 11a of the rotating base 11, from each side separated by the rotating shaft Sb. At this time, the insert fitting 50 is placed on the mounting surface 23 in a predetermined mounting configuration.

[0053] Specifically, as shown in Figure 6, the insert fitting 50 is positioned vertically with the opening 51a of the rectangular tube portion 51 facing downwards, and the peripheral edge 51aa of the opening 51a of the rectangular tube portion 51 (see Figures 1 and 2) is placed on the mounting surface 23. In Figure 6, the insert fitting 50 is indicated by a dashed line.

[0054] Furthermore, as shown in Figure 5, the insert fitting 50 is positioned such that, in a plan view, one of the diagonals of the rectangular tube portion 51 (for example, 51Xb) coincides with the arrangement direction Xb of the pair of pipe mounting members 20, and the pipe axis Sa is coaxial with the rotation axis Sb of the turntable 11. In other words, when the insert fitting 50 is placed on the mounting surface 23 in this predetermined mounting configuration, the lower ends of each corner portion 57b of the rectangular tube portion 51, which lies on the diagonal 51Xb, are placed on the pair of mounting surfaces 23.

[0055] Furthermore, as shown in Figures 3, 5, and 6, each of the pair of mounting surfaces 23 is provided with a restricting projection 24 that restricts the radial movement of the insert fitting 50 when it is mounted in a predetermined mounting configuration. The restricting projection 24 is formed to protrude upward from the mounting surface 23 so as to be able to contact the peripheral edge 51aa of the opening 51a of the rectangular tube portion 51 of the insert fitting 50 mounted on the mounting surface 23 in a predetermined mounting configuration from the radially outer side.

[0056] The restricting projection 24 is not limited to being formed to restrict the insert fitting 50 in the radial direction, as in this embodiment, but may also be formed to restrict it in the circumferential direction, or at least one may be provided at a position that restricts it in both the radial and circumferential directions. Furthermore, the restricting projection 24 is not limited to being configured to abut against the peripheral edge 51aa of the opening 51a of the rectangular tube portion 51 from the radially outer side, but may also be configured to abut against it from the radially inner side.

[0057] As shown in the figure, the internal pressurizing means 30 is provided in pairs, each comprising a pressurizing type 31, a pressurizing type support member 33 that supports the pressurizing type 31, and a radial movement means 32.

[0058] The pair of pressure molds 31 are formed to be the same shape and size as each other, and each has a pressure surface 34 formed on its outer surface that presses on the vertical wall-shaped inner circumferential surface 56 (see Figure 5), and is formed in a plate shape with a thickness slightly greater than the vertical width of the water-swellable sheet 5 that is temporarily attached to the entire circumference of the inner circumferential surface 56 of the rectangular tube portion 51. The pressure surface 34 is formed to be convex in a plan view corresponding to the corners 57 (57a, 57b) that are present in the circumferential direction of the inner circumferential surface 56, so as to be able to press on the corners 57 (57a, 57b) that are present in the circumferential direction of the inner circumferential surface 56.

[0059] As shown in Figures 3 and 5, the pair of pressurized molds 31 are positioned horizontally and facing each other in a symmetrical orientation with their pressurized surfaces 34 facing opposite directions, separated by the pipe axis Sa. Although not shown, each of the pair of pressurized molds 31 also has a built-in heater capable of heating at least the pressurized surface 34 to a predetermined temperature.

[0060] The pressurized type 31 of this embodiment is formed in the shape of a roughly right-angled isosceles triangle in plan view, and pressurized surfaces 34 are formed on the outer circumferential surfaces of the parts corresponding to the apex and the two hypotenuses of the roughly right-angled isosceles triangle.

[0061] As shown in Figures 4 and 6, the radial movement means 32 includes a linear guide member 35 mounted on the upper surface 11a of the turntable 11, and a slider 36 (see Figures 4 and 6) provided above the linear guide member 35 and moving horizontally in a straight line relative to the linear guide member 35. As shown in Figure 6, the upper surface of the slider 36 is positioned lower than the mounting surface 23 of the pipe mounting member 20.

[0062] The pair of radial moving means 32 are arranged in a point-symmetrical position across the pipe axis Sa in a plan view, so that each slider 36 can slide in a direction that brings it closer to or further away from each other, and are also arranged in parallel to each other in a direction perpendicular to the respective sliding direction in a plan view.

[0063] As shown in Figures 3, 4, and 6, the pressurized support member 33 is erected above the mounting surface 23 of the pipe mounting member 20 from the upper surface of the slider 36 so as to be insertable through the opening 51a into the rectangular tube portion 51 of the insert joint 50, which is placed on the mounting surface 23 of the pipe mounting member 20 in a predetermined mounting configuration. Furthermore, the pressurized type 31 is integrally fixed to the upper part of the pressurized support member 33. As a result, the pair of pressurized types 31 are horizontally supported by the pressurized support member 33.

[0064] In other words, the pair of pressure types 31 are integrally fixed to the corresponding slider 36 via a pressure type support member 33, and move closer to or further apart from each other as the pair of sliders 36 move closer to or further apart from each other.

[0065] Furthermore, as shown in Figures 5 and 6, the pressurized support member 33 supports the pressurized support member 33 from below at the same height as the water-expandable sheet 5 temporarily attached to the inner circumferential surface 56 of the rectangular tube portion 51, which is placed on the mounting surface 23 of the pipe mounting member 20 in a predetermined mounting configuration. This makes it possible to match the height of the pressurized support member 31 simply by placing the insert fitting 50 on the mounting surface 23 of the pipe mounting member 20 in a predetermined mounting configuration, while keeping the water-expandable sheet 5 temporarily attached to the inner circumferential surface 56.

[0066] Furthermore, as described above, the pair of radial moving means 32 have linear guide members 35 mounted on the upper surface 11a of the turntable 11. Therefore, the pair of pressurized types 31 rotate together with the turntable 11 around the rotation axis Sb.

[0067] In this case, as shown in Figures 5 and 9, inside the rectangular tube portion 51 of the insert fitting 50 placed on the mounting surface 23 of the pipe mounting member 20 in a predetermined mounting configuration, the pair of pressurizing types 31 rotate relative to each other (change of orientation) as the turntable 11 rotates clockwise or counterclockwise around the rotation axis Sb within a 90-degree angular range in plan view, so that the orientation of the pair of pressurizing types 31 coincides with either one diagonal 51Xa or the other diagonal 51Xb of the rectangular tube portion 51.

[0068] As a result, the pair of pressure molds 31 are capable of pressurizing the corner 57a on one diagonal 51Xa of the rectangular tube portion 51, and also capable of pressurizing the corner 57b on the other diagonal 51Xb. In other words, the pair of pressure molds 31 are formed to be able to pressurize the water-swellable sheet 5, which is temporarily attached to the inner circumferential surface 56, in two stages.

[0069] Figure 11 is a schematic orthogonal cross-sectional view of the rectangular tube portion 51 in the direction of the tube axis, showing the relationship between the lengths La and Lb of the portion 80 between the corner vertices of the inner circumferential surface 56 of the rectangular tube portion 51 (described later) and the sheet pressing portions 81a and 81b by the pair of pressure molds 31 before and after the relative rotation described above. In Figure 11, the pair of pressurizing types 31 shown by dashed lines represent the pair of pressurizing types 31 that pressurize the inner circumferential surface 56 of the rectangular tube portion 51 for the first time, and the pair of pressurizing types 31 shown by dashed lines in Figure 11 represent the pair of pressurizing types 31 that pressurize the inner circumferential surface 56 of the rectangular tube portion 51 for the second time.

[0070] As shown in Figure 11, in a plan view, the portion corresponding to the space between the vertices 58a and 58b of adjacent corners 57a and 57b on the inner circumferential surface 56 of the rectangular tube portion 51 is defined as the inter-corner vertex portion 80, and the length of the inter-corner vertex portion 80 is defined as the inter-corner vertex length LA.

[0071] In plan view, at each of the inter-corner vertex portions 80 on the inner circumferential surface 56 of the rectangular tube portion 51, the sum of the lengths of the sheet pressing portions 81a and 81b, which are pressed by a pair of pressing types 31 before and after the relative rotation (La + Lb), is set to be shorter than the inter-corner vertex length LA of the inter-corner vertex portion 80.

[0072] In this embodiment, the pair of pressure molds 31 are formed to be the same size and shape as each other. Therefore, the sheet pressure portions 81a and 81b that the pair of pressure molds 31 apply pressure to before and after the relative rotation are both set to be less than or equal to half the length LA between the corner vertices in a plan view.

[0073] On the other hand, as shown in Figure 7, when the pair of pressurized molds 31 are in the closest proximity to each other, the maximum diameter Lm in a plan view is set to be shorter than the length of one side of the inner circumferential surface 56 (i.e., the inner diameter LB of the rectangular tube portion 51) minus the thickness equivalent to the water-expandable sheet 5 temporarily attached over the entire circumference of the inner circumferential surface 56 (t × 2) (LB - 2t).

[0074] In this embodiment, the length between the tops 31t, 31t of the pair of pressurized molds 31 that are closest to each other corresponds to the maximum diameter Lm of the pair of pressurized molds 31. As a result, the pair of pressurized molds 31 are set to a size that ensures they do not interfere with the water-expandable sheet 5 temporarily attached to the inner circumferential surface 56 of the rectangular tube portion 51 when they rotate relative to each other.

[0075] Furthermore, the pair of pressure molds 31 are supported by the pressure mold support member 33 in such a manner that the convex pressure surfaces 34 protrude radially outward from the pressure mold support member 33. That is, in a plan view, the maximum diameter of the pair of pressure mold support members 33 is set to a length that does not interfere with the locking projections 55 (see Figures 1 and 2) that protrude inward from the inner circumferential surface 56 of the rectangular tube portion 51 when the pair of pressure mold support members 33 are inserted into the rectangular tube portion 51 or when they are rotated relative to each other while inserted.

[0076] As shown in Figures 3 and 5, the outer support means 40 is provided in pairs so as to face each other on each side of the rotation axis Sb of the turntable 11 in an orthogonal direction Xa that is perpendicular to the arrangement direction Xb of the pair of pipe mounting members 20 in a plan view.

[0077] More specifically, the outer support means 40 includes a pair of outer support members 41 that support the rectangular tube portion 51 from the outside, an outer support member moving means 42 that moves the outer support members 41 radially so that they can be separated from or in contact with the rectangular tube portion 51, and an outer support means support column member 43 (see Figure 3).

[0078] The outer support member 43 is erected upward from the upper surface of the base 2, and is equipped with an outer support member moving mechanism 42 at its upper part. The outer support member moving means 42 includes a linear guide member 44 supported from below by the outer support member support column 43, and a slider 45 that moves horizontally in a straight line relative to the linear guide member 44.

[0079] The pair of sliders 45 move in a straight line in a direction that brings them closer to or further apart from each other with respect to the axis of rotation Sb. The outer support member 41 is fixed integrally with the sliders 45 while resting on the upper surface of the sliders 45.

[0080] As shown in Figures 3 and 6, the outer support member 43 described above supports the outer support member 41 from below via the outer support member moving means 42 so that it is at the same height as the pressurized type 31.

[0081] Furthermore, the outer support member 41 moves radially so as the slider 45 moves in a straight line, it can move away from the rectangular tube portion 51 (see Figure 5) or come into contact with it from the outside (see Figure 7). As shown in Figure 7, when the insert fitting 50 is placed on the mounting surface 23 of the pipe mounting member 20 in a predetermined mounting configuration, the outer support member 41 supports the rectangular tube portion 51 from the outside by coming into contact with it from the outside in a plan view. That is, the pair of outer support members 41 hold the rectangular tube portion 51 by sandwiching it and coming into contact with it from both outside sides separated by the rectangular tube portion 51.

[0082] As shown in Figures 3 and 5, the pair of outer support members 41 are formed to be the same shape and size as each other. Specifically, the outer support member 41 is formed in a Y-shape in plan view, consisting of a base 46 and a pair of protruding pieces 47 that branch out from the base 46 in a bifurcated manner. The pair of outer support members 41 are arranged so that their respective protruding pieces 47 face each other across the pipe axis Sa in a plan view.

[0083] When the insert fitting 50 is placed on the mounting surface 23 of the pipe mounting member 20 in a predetermined mounting configuration, the pair of outer support members 41 are arranged such that their respective arrangement directions Xa are symmetrical with respect to one diagonal 51Xa of the rectangular tube portion 51. Therefore, the pair of outer support members 41 are arranged so that their respective base portions 46 can abut against each corner portion 57a ​​that lies on one diagonal 51Xa from the outside.

[0084] As a result, as shown in Figure 8, when a corner 57a on one diagonal 51Xa is pressurized from the inside by the pressurizing type 31, the corner 57a can be supported from the outside mainly by the base 46 of the outer support member 41.

[0085] Furthermore, as shown in Figure 7, the pair of protruding pieces 47 are formed to protrude linearly along the outer circumferential surface of the rectangular tube portion 51 until the tip 47a in the protruding direction approaches the other diagonal 51Xb when the base portion 46 is in contact with the corner portion 57a. That is, when the base portion 46 of the pair of outer support members 41 is in contact with the corner portion 57a, the tip 47a in the protruding direction of each protruding piece 47 is positioned so that it circumferentially coincides with the corner portion 57b (see Figure 10) which is pressed by the respective pressing surfaces 34 of the pair of pressurizing molds 31 after the relative rotation.

[0086] As a result, as shown in Figure 10, when the corner 57b on the other diagonal 51Xb is pressed from the inside by the pressurizing type 31, the respective tips 47a of the pair of outer support members 41 can cooperate to support the corner 57b from the outside.

[0087] In other words, the pair of protruding pieces 47 can directly receive and support from the outside of the rectangular tube portion 51 regardless of whether the pressure applied by the pressurizing type 31 is applied to the corner portion 57a ​​on one diagonal 51Xa or to the corner portion 57b on the other diagonal 51Xb.

[0088] Next, an example of the procedure (abbreviated as "sheet attachment procedure") for attaching a water-expandable sheet 5, which has been temporarily attached to the entire circumference of the inner surface 56 of the rectangular tube portion 51, to the inner surface 56 by pressurizing it using the water-expandable sheet attachment device 1 of this embodiment will be described.

[0089] The seat installation procedure involves performing the following steps in this order: external support step, first pressurization step, pressurized posture change step, second pressurization step, pressurized posture return step, and external support release step.

[0090] Furthermore, the water-expandable sheet mounting device 1 is assumed to have its main power switch turned ON in advance, and at least the pressurizing surface 34 is assumed to be heated to a predetermined temperature by the heater built into the pressurizing type 31. Also, as shown in Figure 5, in the initial state of the water-expandable sheet mounting device 1, the pair of outer support members 41 are both positioned in a retracted position spaced radially outward from the rectangular tube portion 51, and the pair of pressurizing types 31 are both positioned in a retracted position spaced radially inward from the inner circumferential surface 56. In addition, the pair of pressurizing types 31 are positioned so that their respective positions coincide with the positioning direction Xa of the pair of outer support means 40.

[0091] First, the worker places the insert fitting 50 on the mounting surface 23 in a predetermined mounting configuration. At this time, one diagonal 51Xa of the rectangular tube portion 51 coincides with the arrangement direction Xa of the pair of outer support means 40, and the other diagonal 51Xb coincides with the arrangement direction Xb of the pair of pipe mounting members 20.

[0092] When the operator turns on the start button (not shown) of the water-expandable sheet mounting device 1, the outer support process is executed. That is, in the outer support process, the pair of outer support members 41 move from a retracted position to a radially inward position relative to the rectangular tube portion 51, and as shown in Figure 7, they come into contact with each corner portion 57a ​​on one of the diagonals 51Xa of the rectangular tube portion 51 from the outside. As a result, the pair of outer support members 41 are positioned along the outer surface of the rectangular tube portion 51 over almost the entire circumference in a plan view, and they press down on and support the rectangular tube portion 51 from both sides.

[0093] Furthermore, even if the insert joint 50 is placed on the mounting surface 23 with a circumferential misalignment relative to the predetermined mounting configuration, the circumferential misalignment of the insert joint 50 can be corrected when the pair of outer support members 41 come into contact with the rectangular tube portion 51 during the outer support process.

[0094] In the subsequent first pressurization step, as shown in Figure 8, the pair of pressurizing molds 31 move radially outward from their retracted position, pressurizing each corner 57a on one diagonal 51Xa of the inner circumferential surface 56 of the rectangular tube portion 51. At the same time, the outer support member 41 can directly receive the radially outward pressurization of the corners 57a by the pressurizing molds 31 from the outside of the rectangular tube portion 51 by its base 46. Therefore, the pressurizing molds 31 can pressurize the corners 57a in a stable state.

[0095] When the rectangular tube portion 51 is pressurized by the pressurizing mold 31, the pressurizing surface 34, which has been heated to a predetermined temperature by the heater, is pressed against the water-expandable sheet 5 temporarily attached to the inner circumferential surface 56 for a predetermined time. Since the pressurizing surface 34 is formed in a convex shape in plan view, corresponding to the shape of the inner circumferential surface 56 of the corner portion 57a, the water-expandable sheet 5 can be attached to the inner circumferential surface 56 without any gaps by pressing it into every corner of the corner portion 57a. After the pressurizing time has elapsed, the pair of pressurizing molds 31 move inward in diameter to the retracted position (see Figure 7).

[0096] In the subsequent pressurized type orientation change process, as shown in Figure 9, the pair of pressurized types 31 rotate 90 degrees counterclockwise in a plan view around the pipe axis Sa from an orientation where their positioning direction coincides with one diagonal 51Xa of the rectangular tube portion 51, i.e., the positioning direction Xa of the pair of outer support means 40. As a result, the pair of pressurized types 31, while remaining inserted inside the rectangular tube portion 51, rotate relatively (change orientation) to an orientation where their respective positioning directions coincide with the other diagonal 51Xb, i.e., the positioning direction Xb of the pair of pipe mounting members 20.

[0097] Furthermore, when the pair of pressurized support members 33 (see Figure 6) are inserted into the rectangular tube portion 51, they are positioned at the same height as the locking projections 55 (see Figures 1 and 2) that protrude inward from the inner circumferential surface 56 of the rectangular tube portion 51, as described above. However, they do not interfere with the locking projections 55 and can rotate relative to the pair of pressurized members 31.

[0098] In the subsequent second pressurization step, as shown in Figure 10, the pair of pressurization molds 31 move from their retracted position outward in diameter, and pressurize each corner 57b on the inner circumferential surface 56 of the rectangular tube portion 51 that is on the other diagonal 51Xb in the same manner as in the first pressurization step. In the second pressurization step, similar to the first pressurization step, the pair of pressurizing molds 31 move inward to the retracted position after the pressurization time has elapsed.

[0099] Furthermore, as shown in Figure 10, when the pressure type 31 pressurizes the corner portion 57b, the pair of outer support members 41 can directly receive the pressure applied by the pressure type 31 to the outer diameter of the corner portion 57b from the outside of the rectangular tube portion 51 by cooperating with the tips 47a of the protruding pieces 47. Therefore, the pressure type 31 can pressurize the corner portion 57b in a stable state.

[0100] As described above, the water-expandable sheet 5 can be attached to the four corners 57 (57a, 57b) on the inner circumferential surface 56 of the rectangular tube portion 51, and a slip-on joint 50 as shown in Figure 12 can be obtained.

[0101] In the subsequent pressurized return position process, the pair of pressurized molds 31 rotate 90 degrees clockwise in a plan view around the pipe axis Sa from a position where their orientation coincides with the other diagonal 51Xb of the rectangular tube portion 51, i.e., the orientation Xb of the pair of pipe mounting members 20 (see Figure 9). As a result, the pair of pressurized molds 31 return to their initial position (see Figure 7), which coincides with the orientation 51Xa of one of the diagonals, i.e., the orientation Xa of the pair of outer support means 40.

[0102] In the subsequent outer support release step, the pair of outer support members 41 are moved radially outward to a retracted position (see Figure 5), thereby releasing the support of the rectangular tube portion 51 by the pair of outer support members 41, and the insert joint 50 placed on the mounting surface 23 can be removed.

[0103] The seat installation procedure described above is just one example; other procedures may also be used. Specifically, the pair of outer support members 41, after initially supporting the rectangular tube portion 51 from the outside during the outer support process, maintain the state of supporting the rectangular tube portion 51 without moving to the retracted position until at least the second pressurizing process is completed. Therefore, the outer support release process may be performed not only after the pressurized posture return process, as in the sheet mounting procedure described above, but also before or simultaneously with the pressurized posture return process, as long as it is performed after the second pressurizing process is completed.

[0104] Furthermore, the first and second pressurizing processes are not limited to being performed in this order; they may also be performed in the reverse order. Specifically, the pair of pressurizing molds 31 may perform a first pressurizing process in which the corner portion 57b located on the other diagonal 51Xb of the rectangular tube portion 51 is pressurized, and then, after rotating relative to each other 90 degrees clockwise, perform a second pressurizing process in which the corner portion 57a ​​located on one of the diagonal 51Xa is pressurized.

[0105] As shown in Figures 3 to 6, the water-expandable sheet mounting device 1 of the above embodiment includes a pressure type 31 that pressurizes the water-expandable sheet 5 (see Figure 7), which has been temporarily attached to the entire circumference of the inner circumferential surface 56 of the square-shaped rectangular tube portion 51 of the insert joint 50, toward the inner circumferential surface 56, and a radial moving means 32 (see Figures 3, 4, and 6) that moves the pressure type 31 radially away from or pressurized relative to the inner circumferential surface 56. The pressure type 31 has a convex pressure surface 34 formed corresponding to the corner portion 57 so as to be able to pressurize the corner portion 57 that is present in the circumferential direction of the inner circumferential surface 56, and a pair of pressure types are provided that are arranged opposite each other in a point-symmetrical position with the pressure surfaces 34 facing opposite directions across the pipe axis Sa. The pressurized type 31 is provided with a circumferential moving means 10 (see Figures 3, 4, and 6) that rotates the pressurized type 31 relative to the insert joint 50 around the pipe axis Sa within a range where the arrangement direction of the pressurized type 31 coincides with either one diagonal 51Xa or the other diagonal 51Xb. As shown in Figure 11, in any of the four inter-corner vertex portions 80 on the inner circumferential surface 56 of the rectangular tube portion 51 in a plan view, the sum of the lengths of the sheet pressurized portions 81a and 81b that the pair of pressurized types 31 pressurize before and after the relative rotation (La + Lb) is set to be shorter than the inter-corner vertex length LA of the inter-corner vertex portion 80 (see Figure 11).

[0106] According to the above configuration, the pair of pressurized types 31 can be made more compact, allowing them to rotate relative to each other around the tube axis Sa while remaining inserted inside the rectangular tube section 51. Therefore, there is no need to rotate the pair of pressurized types 31 relative to each other after removing them from inside the rectangular tube section 51, nor is there a need to separately provide a pair of pressurized types 31 to accommodate the layout after the orientation has been changed. This results in a simpler configuration, reducing the number of parts and making the entire device smaller.

[0107] Furthermore, in the pressurized posture change process and the pressurized posture return process, when the pair of pressurized molds 31 are rotated relative to each other around the tube axis Sa, there is no need to remove and reinsert them into the rectangular tube section 51, thereby improving the work efficiency of the sheet installation procedure.

[0108] Here, as described above, in plan view, in each of the inter-corner vertex portions 80 on the inner circumferential surface 56 of the rectangular tube portion 51, the sum of the lengths of the sheet pressing portions 81a and 81b, which are pressed by the pair of pressing types 31 before and after the relative rotation (La + Lb), is set to be shorter than the inter-corner vertex length LA of the inter-corner vertex portion 80.

[0109] Therefore, in each of the four inter-corner vertex portions 80 on the inner circumferential surface 56 of the rectangular tube portion 51, the sheet pressing portions 81a and 81b, which are pressed by the pair of pressurizing types 31 before and after the relative rotation, are spaced apart from each other in a plan view.

[0110] In other words, as shown in Figure 11, between the sheet pressurized portion 81a and the sheet pressurized portion 81b in the corner vertex portion 80, there is a portion where the water-expandable sheet 5 is not pressurized by the pressurizing mold 31 (referred to as the "unpressurized sheet portion 82").

[0111] Thus, even if an unpressurized portion 82 of the sheet remains in the circumferential direction of the inner surface 56 after two separate pressurizing processes by a pair of pressurizing types 31, the water-expandable sheet mounting device 1 of this embodiment is configured to pressurize the four corners 57 on the inner surface 56 of the rectangular tube portion 51. Therefore, the water-expandable sheet 5, including the unpressurized portion 82, can be aligned along the entire circumference of the inner surface 56.

[0112] More specifically, when the pressurizing mold 31 pressurizes the corner portion 57 on the inner circumferential surface 56 of the rectangular tube portion 51, the water-expandable sheet 5 is pressed by the convex pressurizing surface 34 of the pressurizing mold 31 into a shape that conforms to the inner circumferential surface 56 of the corner portion 57. At this time, the water-expandable sheet 5 can be firmly attached to the corner portion 57. In addition, as the pressurizing mold 31 presses the water-expandable sheet 5 into a shape that conforms to the inner circumferential surface 56, the unpressurized portion 82 of the water-expandable sheet 5 is pulled (stretched) towards the corner portion 57 along the inner circumferential surface 56.

[0113] As a result, the water-expandable sheet mounting device 1 of this embodiment can ensure that the water-expandable sheet 5 conforms to the inner circumferential surface 56 without any sagging occurring in the water-expandable sheet 5 over the entire circumference of the inner circumferential surface 56, including the non-pressurized portion 82 of the sheet.

[0114] Therefore, as described above, the water-expandable sheet mounting device 1 of this embodiment, despite its simple configuration, can attach the water-expandable sheet 5 to the inner circumferential surface 56 of the rectangular tube portion 51 in a state where it conforms precisely to the entire circumference of the inner circumferential surface 56.

[0115] Consequently, when inserting the rectangular tube 60 into the rectangular tube section 51 for connection, the water-swellable sheet 5 does not get caught on the rectangular tube 60 or peel off, allowing the rectangular tube 60 to be inserted properly.

[0116] Furthermore, as described above, the water-expandable sheet mounting device 1 of this embodiment can pull the water-expandable sheet 5 along the inner circumferential surface 56 toward the corner portion 57 by applying pressure in two stages using a pair of pressure types 31. For example, as described above, when a worker temporarily attaches the water-expandable sheet 5 to the inner circumferential surface 56 of the rectangular tube portion 51 by hand, even if a radial gap occurs between the inner circumferential surface 56 and the device in at least a part of the circumferential direction or vertical direction (pipe axis Sa direction), the device can ultimately attach the sheet with the gap between the sheet and the inner circumferential surface 56 eliminated.

[0117] Furthermore, in both pressurizing processes, the pair of pressurizing molds 31 apply pressure to the corners 57 on both sides of the diagonals 51Xa and 51Xb in opposite directions, allowing the water-expandable sheet 5 to be pressed evenly in the circumferential direction toward the inner surface 56.

[0118] Furthermore, when a worker temporarily attaches the water-swellable sheet 5 to the inner surface 56 of the rectangular tube portion 51 by hand, as described above, the corners 57a and 57b of the inner surface 56 of the rectangular tube portion 51 are particularly susceptible to pressure from the worker's fingers. For this reason, the pressing of the water-swellable sheet 5 onto the inner surface 56 is usually started from the predetermined corners 57a and 57b of the inner surface 56 of the rectangular tube portion 51.

[0119] In that case, for example, as shown in Figure 7, the seam 90 where the longitudinal ends 91,91 of the strip-shaped water-expandable sheet 5, which is temporarily attached over the entire circumference of the inner surface 56 of the rectangular tube portion 51, overlap radially, is located at the corner 57a. In this embodiment, as shown in Figure 8, when the corner 57a of the inner surface 56 of the rectangular tube portion 51 is pressed by the pressure mold 31, the seam 90 of the water-expandable sheet 5, which is prone to curling, is firmly pressed towards the inner surface 56.

[0120] As a result, the water-expandable sheet 5 does not bulge inward in diameter relative to the surrounding area because the ends 91, 91 at the joint 90 overlap radially. Therefore, when inserting the rectangular pipe 60 into the rectangular tube section 51 for connection, the water-expandable sheet 5 does not peel off due to the joint 90 catching on the rectangular pipe 60, allowing the rectangular pipe 60 to be inserted properly.

[0121] As shown in Figures 4 and 6, in this embodiment of the invention, a pipe mounting member 20 has a mounting surface 23 on which the peripheral edge 51aa of the opening 51a of the rectangular tube portion 51 is placed so as to be able to support the insert fitting 50 in a position where the opening 51a of the rectangular tube portion 51 faces downward, and a pressure type support member 33 that protrudes upward from the mounting surface 23 so as to be insertable into the interior of the rectangular tube portion 51 placed on the mounting surface 23 through the opening 51a, and supports the pressure type 31 from below at the same height as the water-expandable sheet 5 (see Figure 5) temporarily attached to the inner circumferential surface 56.

[0122] With the above configuration, the pressurized mold 31 can be inserted into the rectangular tube section 51 together with the pressurized mold support member 33 simply by placing the insert fitting 50 on the mounting surface 23. Furthermore, the water-expandable sheet 5 temporarily fixed to the inner circumferential surface 56 and the pressurized mold 31 can be made to the same height inside the rectangular tube section 51.

[0123] As shown in Figures 3, 5, and 6, in this embodiment of the invention, the mounting surface 23 is provided with a restricting projection 24 that protrudes upward so as to be able to abut against the peripheral edge 51aa of the opening 51a of the rectangular tube portion 51 placed on the mounting surface 23, thereby restricting the insertion joint 50 in the radial direction.

[0124] With the above configuration, the insert fitting 50 can be easily placed on the mounting surface 23 by simply placing it vertically from above, rather than by, for example, fitting it into a predetermined mounting location from the side. Furthermore, by simply placing the insert fitting 50 on the mounting surface 23, the regulating projection 24 can be brought into contact with the peripheral edge 51aa of the opening 51a of the rectangular tube portion 51 from the radially outer side, thereby regulating the radial relative position of the insert fitting 50 placed on the mounting surface 23 with respect to the pressurized type 31.

[0125] As shown in the figure, one aspect of this invention is that the rectangular tube portion 51 is supported by an outer support member 41 from the radially outer side, and an outer support member moving means 42 is provided to move the outer support member 41 radially so that it can be separated from or in contact with the rectangular tube portion 51.

[0126] With the above configuration, by bringing the outer support member 41 into contact with the rectangular tube portion 51, the insert joint 50 can be firmly supported from the outer diameter by the outer support member 41, while by separating it from the rectangular tube portion 51, the insert joint 50 can be easily placed on and removed from the mounting surface 23.

[0127] Furthermore, when the inner circumferential surface 56 of the insert fitting 50 is pressurized by the pressurizing type 31, a conventional support member for supporting the insert fitting 50 from the outside, such as the support member (34) disclosed in Patent Document 1, is configured in a cylindrical shape so that a pipe fitting (3) corresponding to the insert fitting 50 can be fitted inside and supported from the outside.

[0128] To firmly support the insert fitting 50 from the outside using such a support member (34), it is necessary to minimize the clearance between the inner surface of the support member (34) and the outer surface of the rectangular tube portion 51 of the insert fitting 50.

[0129] However, in that case, it may become difficult to insert and remove the insert fitting 50 from the support member (34) when placing or removing the insert fitting 50 from the mounting surface 23. On the other hand, if the clearance between the inner circumferential surface of the support member (34) and the outer circumferential surface of the rectangular tube portion 51 of the insert fitting 50 is set to be large, the support member (34) may not be able to firmly hold the insert fitting 50 from the outside.

[0130] In contrast, as described above, the present invention allows the insert joint 50 to be firmly held in place from the outside by the outer support member 41 by contacting the outer circumferential surface of the rectangular tube portion 51, while the insert joint 50 can be easily placed on or removed from the mounting surface 23 by spacing the outer support member 41 apart from the outer circumferential surface of the rectangular tube portion 51.

[0131] As shown in Figure 5, in this embodiment of the invention, the pair of outer support members 41 are arranged facing each other on either diagonal (e.g., 51Xa) on each side of the rectangular tube portion 51, and each of the pair of outer support members 41 is formed with a pair of protruding pieces 47 that protrude along the outer circumferential surface of the rectangular tube portion 51 to each side of the rectangular tube portion 51 on the other diagonal 51Xb. Furthermore, as shown in Figure 10, the tip 47a of each pair of protruding pieces 47 of the pair of outer support members 41 in the direction of protrusion is configured to coincide with the pressurizing surface 34 of a pair of pressurizing molds 31 arranged on the other diagonal 51Xb and in a pressurized position, and the circumferential direction of the rectangular tube portion 51.

[0132] With the above configuration, as shown in Figure 8, when pressurizing the corner 57a on one diagonal 51Xa of the pair of pressurized members 31, and as shown in Figure 10, when pressurizing the corner 57b on the other diagonal 51Xb of the second pressurized member 31, the pair of outer support members 41 can support the rectangular tube portion 51 from the outside while maintaining the same posture and position.

[0133] Therefore, the configuration of the water-expandable sheet mounting device 1 and the sheet mounting procedure can be further simplified.

[0134] In the correspondence between the configuration of this invention and the above-described embodiment, the pipe material corresponds to the insert fitting 50, and similarly, the respective protruding tips of the pair of outer support members correspond to the respective protruding tips 47a of the pair of protruding pieces 47. However, this invention is not limited to the configuration of the above-described embodiment, and many other embodiments can be obtained.

[0135] For example, in this embodiment, the rotating table 11, the pressurizing type 31, and the outer support member 41 are all driven by a pneumatic cylinder 13. However, at least one of the rotating table 11, the pressurizing type 31, and the outer support member 41 may be driven by a fluid cylinder or a motor, among other things, instead of a pneumatic cylinder 13.

[0136] Furthermore, as described above, the circumferential moving means 10 is not limited to the configuration in which the pressing die 31 is relatively rotated about the pipe axis Sa with respect to the insertion joint 50, and may be configured to relatively rotate the insertion joint 50 with respect to the pressing die 31, or may be configured to relatively rotate both the insertion joint 50 and the pressing die 31.

[0137] Furthermore, the work of placing the insertion joint 50 on the placement surface 23 of the pipe placement member 20 is not limited to being performed manually, and for example, a supply means for automatically supplying the insertion joint 50 to the placement surface 23 may be provided.

[0138] Furthermore, the pipe material of the present invention is not limited to being formed as a joint for connecting a socket joint 70 connected and fixed to the handhole side and a square pipe 60 as a pipe material like the insertion joint 50 of the present embodiment, and may be formed as a joint for connecting pipe materials to each other, that is, for connecting square pipes 60 to each other.

[0139] Specifically, in the insertion joint 50 of the above-described embodiment, a square cylindrical portion 51 as a female connection portion is provided on one side Ya in the pipe axis direction Y, and a cylindrical portion 52 as a male connection portion is provided on the other side Yb. However, when the pipe material of the present invention is configured as a joint for connecting square pipes 60 to each other, although not shown in the drawings, it may be configured to have square cylindrical portions 51 on both sides Ya and Yb in the pipe axis direction Y.

[0140] Furthermore, in the above-described embodiment, the water-swellable sheet attaching apparatus of the present invention has a configuration in which the relationship ((La+Lb)<LA) is satisfied in any of the four inter-corner-vertex portions 80 provided on the inner peripheral surface 56 of the square cylindrical portion 51 in a plan view, but the present invention is not limited thereto, and any configuration is acceptable as long as the relationship is satisfied in at least one of the four inter-corner-vertex portions 80. Description of Reference Signs

[0141] 1… Water-swellable sheet attaching apparatus 5… Water-swellable sheet 10… Circumferential moving means 20… Pipe placement member 23… Placement surface 24… Regulatory protrusion (regulatory part) 31…Pressurized type 32... means of radial movement 33...Pressure-type support member 34…Pressure surface 41...Outer support member 42...Outer support member moving means 47a...The tip of each projection in the direction of projection of a pair of protruding pieces (the tip of each projection in the direction of projection of a pair of outer support members) 50…Pipe fittings 51...Square tube part 51Xa... A pair of diagonals 51Xb...the other diagonal 51a...Opening of the rectangular tube section 51aa... Periphery of the opening of the rectangular tube section 56... Inner surface of the rectangular tube section 57... Corner 80... Corner vertex section Sa... Pipe axis LA...Length between corner vertices

Claims

1. A water-expandable sheet mounting device comprising a pressure type for applying pressure to the inner surface side of a water-expandable sheet temporarily attached to the entire inner surface of a square-shaped rectangular tube portion of a pipe material, and a radial movement means for moving the pressure type radially so as to be able to move away from or apply pressure to the inner surface, The above-described pressurized type is provided with a pair of pressurized surfaces, each having a convex pressurized surface formed corresponding to the corners in the circumferential direction of the inner surface, and the pressurized surfaces are arranged facing each other in opposite positions across the tube axis. The device includes a circumferential moving means for relatively rotating at least one of the pipe material and the pressurizing type around the pipe axis within a range where the arrangement direction of the pair of pressurizing types coincides with either one diagonal or the other diagonal, The sum of the length of the portion pressed before the relative rotation and the length of the portion pressed after the relative rotation, in the circumferential direction of the inner surface of the rectangular tube portion, is set to be shorter than the length of the portion between adjacent corner vertices. In the pair of pressurized units described above, when they are in the closest proximity to each other, the maximum diameter in a plan view is set to be shorter than the length of one side of the inner circumferential surface minus the thickness equivalent to the water-expandable sheet temporarily attached to the entire circumference of the inner circumferential surface. A pipe mounting member having a mounting surface on which the periphery of the opening of the rectangular tube portion is placed, so that the pipe material can be supported in a position where the opening of the rectangular tube portion faces downward, The pressurized type support member is provided, which is inserted into the rectangular tube portion placed on the aforementioned surface through the opening, and which protrudes upward from the aforementioned surface, and supports the pressurized type from below at the same height as the water-expandable sheet temporarily attached to the inner circumferential surface. Water-expandable sheet mounting device.

2. The mounting surface described above is provided with a restricting portion that protrudes upward so as to be able to abut against the peripheral edge of the opening of the rectangular tube portion placed on the mounting surface, thereby restricting the tubular material in the radial direction. The water-swellable sheet mounting device according to claim 1.

3. The above rectangular tube portion is provided with an external support member that supports it from the outside in a plan view, The system includes an outer support member moving means for moving the outer support member radially so as to be able to move away from or in contact with the rectangular tube portion. A water-swellable sheet mounting device according to claim 1 or claim 2.

4. The above-mentioned outer support members are provided in pairs so as to be positioned facing each other on either diagonal, separated by the rectangular tube portion. Each of the pair of outer support members is formed to protrude along the outer surface of the rectangular tube portion to each side of the diagonal of the other, separated by the rectangular tube portion. The protruding tips of each of the pair of outer support members coincide with the circumferential direction of the pressure surface of the pair of pressure-type members, which are located diagonally opposite each other and in the pressure position, and the rectangular tube portion. The water-swellable sheet mounting device according to claim 3.

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