Cover for a connecting portion, method for manufacturing the same, connecting system, and method for protecting a connecting portion

Abstract

To provide a connection part cover the heat-retaining property of which is high, and a wave-shaped cladding tube of which is less likely to come off from the connection part cover, to provide a production method of the same, and to provide a protection method of a connection part.SOLUTION: A connection part cover 1 for protecting a connection parts of inner tubes (61, 62) cladded by wave-shaped cladding tubes (71, 72) includes a pair of half-split cylindrical bodies (10A, 10B). A plurality of ribs extending in a circumferential direction at a pitch same as a pitch of valley parts of the wave-shaped cladding tubes are formed in inner surfaces of parts constituting cladding tube storage parts (20, 30) of the half-split cylindrical bodies. When the pair of half-split cylindrical bodies are in a closed state, the ribs of the pair of corresponding half-split cylindrical bodies are connected to make an annular shape, and are continuously engaged with the valley parts of the wave-shaped cladding tubes.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a cover for a connection part, a method for manufacturing the same, and a method for protecting the connection part. More specifically, the present invention relates to a cover for a connection part that covers a connection part for connecting an inner pipe covered with a corrugated coating pipe with a pipe joint, a method for manufacturing the same, a connection system, and a method for protecting the connection part.

Background Art

[0002] For pipes connected to hot water equipment, air conditioning equipment, etc., coated pipes in which an inner pipe is coated with a corrugated coating pipe are used. The corrugated coating pipe protects the inner pipe and also plays a role in keeping warm the hot water or the like flowing through the pipe. For a connection part that connects coated pipes with a pipe joint, a cover for the connection part is used to protect the connection part and enhance the heat retention property of the connection part (Patent Documents 1 and 2).

[0003] The cover for the connection part of Patent Document 1 is made of a hard resin, and in order to prevent it from coming off, annular ribs that bite into the valleys of the corrugated coating pipe are formed at both axial ends. The cover for the connection part of Patent Document 2 is made of a hard resin, and in order to prevent it from coming off, annular ribs that bite into the valleys of the corrugated coating pipe are formed at a total of four positions, namely, both axial ends and positions near the pipe joint.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the cover for the connecting portion in Patent Document 1 had low heat retention for the connecting portion. Also, it was hard to say that the measures against disengagement were sufficient, and the corrugated covering tube was likely to come off from the cover for the connecting portion. In view of the above circumstances, an object of the present invention is to provide a cover for a connecting portion having high heat retention for the connecting portion, a method for manufacturing the same, a connecting system, and a method for protecting the connecting portion, in which the corrugated covering tube is hard to come off from the cover for the connecting portion.

Means for Solving the Problems

[0006] In order to achieve the above object, the present invention employs the following configuration. [1] A connecting portion cover for protecting a connecting portion in which an end portion of a first inner tube exposed from a first corrugated covering tube, which is covered with a first corrugated covering tube having large-diameter ridges and small-diameter valleys formed alternately, and an end portion of a second inner tube exposed from a second corrugated covering tube, which is covered with a second corrugated covering tube having large-diameter ridges and small-diameter valleys formed alternately, are inserted into or externally fitted to a pipe joint, comprising a pair of semi-cylindrical bodies made of a soft foamed resin. In a closed state where both end sides along the axial direction of the pair of semi-cylindrical bodies are joined together, a first covering tube accommodating portion for accommodating the vicinity of the connecting portion of the first corrugated covering tube, a second covering tube accommodating portion for accommodating the vicinity of the connecting portion of the second corrugated covering tube, and a connecting portion accommodating portion between the first covering tube accommodating portion and the second covering tube accommodating portion are configured. On the inner surface of the portion of the pair of semi-cylindrical bodies that constitutes the first covering tube accommodating portion, a plurality of first ribs extending in the circumferential direction are formed at the same pitch as the valleys of the first corrugated covering tube along the axial direction. In the closed state, the corresponding first ribs of the pair of semi-cylindrical bodies are connected to form an annular shape and are configured to continuously engage with the valleys of the first corrugated covering tube. On the inner surface of the portion of the pair of semi-cylindrical bodies that constitutes the second covering tube accommodating portion, a plurality of second ribs extending in the circumferential direction are formed at the same pitch as the valleys of the second corrugated covering tube along the axial direction. In the closed state, the corresponding second ribs of the pair of semi-cylindrical bodies are connected to form an annular shape and are configured to continuously engage with the valleys of the second corrugated covering tube. A cover for a connecting portion, characterized by this. [2] The height of the plurality of first ribs is equal to or greater than the depth of each valley portion of the first corrugated covering tube, and the height of the plurality of second ribs is equal to or greater than the depth of each valley portion of the second corrugated covering tube. The cover for a connecting portion according to [1]. [3] The filling rate of the plurality of first ribs filled in each valley portion of the first corrugated covering tube is 70% or more, and the filling rate of the plurality of second ribs filled in each valley portion of the second corrugated covering tube is 70% or more. The cover for a connecting portion according to [1] or [2]. [4] On the inner surface between the portion constituting the first covering tube accommodating portion and the portion constituting the connecting portion accommodating portion of the pair of semi-cylindrical bodies, first boundary ribs extending in the circumferential direction are respectively formed. In the closed state, the first boundary ribs of the pair of semi-cylindrical bodies are configured to be connected to form an annular shape. On the inner surface between the portion constituting the second covering tube accommodating portion and the portion constituting the connecting portion accommodating portion of the pair of semi-cylindrical bodies, second boundary ribs extending in the circumferential direction are respectively formed. In the closed state, the second boundary ribs of the pair of semi-cylindrical bodies are configured to be connected to form an annular shape. The cover for a connecting portion according to any one of [1] to [3]. [5] On the outer surfaces of the pair of semi-cylindrical bodies, recesses extending in the circumferential direction are formed at a plurality of locations along the axial direction. In the closed state, the recesses of the corresponding pair of semi-cylindrical bodies are configured to be connected to form an annular shape. The cover for a connecting portion according to any one of [1] to [4]. [6] One end side along the axial direction of the pair of semi-cylindrical bodies is connected to form a hinge portion, and the other end side along the axial direction is configured to be openable and closable with respect to each other. The cover for a connecting portion according to any one of [1] to [5]. [7] At both axial ends of the pair of semi-cylindrical bodies, engaging portions for engaging the openable and closable end sides with respect to each other are formed. The cover for a connecting portion according to [6]. [8] A method for manufacturing a cover for a connecting portion according to any one of [1] to [7], characterized by press-molding a sheet-like soft foamed resin. A method for manufacturing a cover for a connecting portion. A connection system, characterized in that a connection part cover according to any one of [1] to [7] houses the connection part and its vicinity. A method for protecting a connection part, characterized in that after housing the connection part and its vicinity in the pair of semi-cylindrical bodies of the connection part cover according to any one of [1] to [7], the connection part cover is fixed so as to be in close contact with the connection part by one or both of a band and a sheet.

Effects of the Invention

[0007] According to the connection part cover of the present invention, its manufacturing method, the connection system, and the method for protecting the connection part, the heat retention property of the connection part is high. In addition, since the corrugated covering tube is difficult to come off from the connection part cover, the connection part can be stably protected.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0009] [Cover for Connecting Portion] The cover for a connecting portion of the present invention is a cover that houses and protects a connecting portion. In this specification and the claims, the connecting portion is a portion where the ends of a pair of inner pipes are connected by being inserted into or externally fitted to a pipe joint. Each of the pair of inner pipes is a pipe whose interior serves as a fluid passage through which a fluid such as water or hot water passes. Each of the pair of inner pipes is covered with a corrugated covering pipe.

[0010] FIG. 1 shows a cover 1 for a connecting portion according to an embodiment of the present invention. In this embodiment, the connecting portion protected by the cover 1 for a connecting portion is, as shown in FIG. 2, the end of the first inner pipe 61 covered with the first corrugated covering pipe 71 and the end of the second inner pipe 62 covered with the second corrugated covering pipe 72 (the ends of the pair of inner pipes), which are inserted into the pipe joint 50. As shown in FIGS. 2 and 3, the cover 1 for a connecting portion covers the connecting portion and its vicinity to protect the connecting portion.

[0011] As shown in FIG. 1, the cover 1 for a connecting portion includes a semi-cylindrical body 10A and a semi-cylindrical body 10B. One end edge along the axial direction of the semi-cylindrical body 10A and the semi-cylindrical body 10B is connected to form a hinge portion 11. The semi-cylindrical body 10A and the semi-cylindrical body 10B are configured such that the other end edges along the axial direction on the side opposite to the hinge portion 11 (the end edge 12A of the semi-cylindrical body 10A and the end edge 12B of the semi-cylindrical body 10B) can be opened and closed with respect to each other.

[0012] The semi-cylindrical body 10A and the semi-cylindrical body 10B are configured to be able to accommodate the connecting portion and its vicinity inside when the end edges 12A and 12B are closed together in a closed state. Specifically, it is configured to include a first coating tube accommodating portion 20 that accommodates the vicinity of the connecting portion of the first corrugated coating tube 71, a second coating tube accommodating portion 30 that accommodates the vicinity of the connecting portion of the second corrugated coating tube 72, and a connecting portion accommodating portion 40 between the first coating tube accommodating portion 20 and the second coating tube accommodating portion 30.

[0013] On the inner surfaces of the portions of the semi-cylindrical bodies 10A and 10B that constitute the first coating tube accommodating portion 20, a plurality of first ribs 21 extending in the circumferential direction are formed along the axial direction. When the semi-cylindrical bodies 10A and 10B are in a closed state, the corresponding first ribs 21 are connected to form an annular shape.

[0014] On the inner surfaces of the portions of the semi-cylindrical bodies 10A and 10B that constitute the second coating tube accommodating portion 30, a plurality of second ribs 31 extending in the circumferential direction are formed along the axial direction. When the semi-cylindrical bodies 10A and 10B are in a closed state, the corresponding second ribs 31 are connected to form an annular shape.

[0015] As shown in FIG. 4, the pitch along the axial direction of the second rib 31 is the same as the pitch of the trough portion 74 of the second corrugated coating tube 72. Similarly, the pitch along the axial direction of the first rib 21 is the same as the pitch of the trough portion 74 of the first corrugated coating tube 71. Since the pitch of the trough portion 74 of the corrugated coating tube (the first corrugated coating tube 71 and the second corrugated coating tube 72) is the same as the pitch along the axial direction of the rib (the first rib 21 and the second rib 31), adjacent ribs can be continuously engaged with adjacent trough portions 74 of the corrugated coating tube.

[0016] The pitch of the trough portion 74 of the corrugated coating tube (the first corrugated coating tube 71 and the second corrugated coating tube 72) refers to the distance between the centers of the bottoms of adjacent trough portions 74. In a normal corrugated coating tube, the distance between the centers of the bottoms of adjacent trough portions 74 is constant over the entire length. The pitch along the axial direction of the ribs (the first rib 21 and the second rib 31) refers to the distance between the centers of the tips of adjacent ribs. Note that in a normal corrugated sheath tube, since the distance between the centers of the bottoms of adjacent 74 is constant over the entire length, the distance between the centers of the tips of adjacent ribs is also constant. For example, when there are three ribs, the distance between the first rib and the second rib is the same as the distance between the second rib and the third rib.

[0017] In this embodiment, an example where there are three first ribs 21 and three second ribs 31 each is shown. However, in the present invention, the first rib 21 and the second rib 31 may each have two or more. It is preferable that the first rib 21 and the second rib 31 each have three or more. If three or more first ribs 21 and three or more second ribs 31 are provided respectively, it is possible to more reliably prevent the first corrugated sheath tube 71 and the second corrugated sheath tube 72 from falling out of the connecting portion cover 1.

[0018] It is preferable that the first rib 21 and the second rib 31 each have five or less, and more preferably four or less. By setting the number of the first rib 21 and the second rib 31 to be equal to or less than the upper limit value of the preferable range respectively, it is possible to prevent the overall length of the connecting portion cover 1 from becoming too long. Also, alignment in the vicinity of the connecting portion with respect to the connecting portion cover 1 becomes easy.

[0019] The axial length of the first sheath tube accommodating portion 20 that covers the first corrugated sheath tube 71 and the axial length of the second sheath tube accommodating portion 30 that covers the second corrugated sheath tube 72 are each preferably 10 mm or more, and more preferably 20 mm or more. If the axial length of covering the corrugated sheath tube is equal to or more than the lower limit value of the preferable range, a sufficient number of ribs can be engaged with the trough portion 74. Also, it is easy to prevent both axial ends of the connecting portion cover 1 from rising from the corrugated sheath tube and a gap from being generated between the connecting portion cover 1 and the corrugated sheath tube. From the viewpoint of not making the overall length of the connecting portion cover 1 too long, the axial length of covering the corrugated sheath tube is preferably 50 mm or less, and more preferably 40 mm or less.

[0020] On the inner surface between the part constituting the first covering tube accommodating portion 20 and the part constituting the connecting portion accommodating portion 40 of the semi-circular cylindrical body 10A and the semi-circular cylindrical body 10B, first boundary ribs 44 extending in the circumferential direction are respectively formed. When the semi-circular cylindrical body 10A and the semi-circular cylindrical body 10B are in a closed state, the respective first boundary ribs 44 are connected to form an annular shape.

[0021] On the inner surface between the part constituting the second covering tube accommodating portion 30 and the part constituting the connecting portion accommodating portion 40 of the semi-circular cylindrical body 10A and the semi-circular cylindrical body 10B, second boundary ribs 45 extending in the circumferential direction are respectively formed. When the semi-circular cylindrical body 10A and the semi-circular cylindrical body 10B are in a closed state, the respective second boundary ribs 45 are connected to form an annular shape.

[0022] The distance between the first boundary rib 44 and the first rib 21 closest to the first boundary rib 44, and the distance between the second boundary rib 45 and the second rib 31 closest to the second boundary rib 45 are each preferably 5 to 10 mm. Thereby, even when the end faces of the first corrugated covering tube 71 and the second corrugated covering tube 72 are cut obliquely, the alignment between the first rib 21 and the trough portion 74 of the first corrugated covering tube 71, and the alignment between the second rib 31 and the trough portion 74 of the second corrugated covering tube 72 become easy.

[0023] The thickness of the part constituting the connecting portion accommodating portion 40 of the semi-circular cylindrical body 10A and the semi-circular cylindrical body 10B is preferably such that the thinnest part is 2 to 10 mm, and more preferably 3 to 5 mm. When the thickness of the part constituting the connecting portion accommodating portion 40 is equal to or greater than the lower limit value of the preferable range, the heat insulation property of the connecting portion not insulated by the corrugated covering tube can be enhanced. When the thickness of the part constituting the connecting portion accommodating portion 40 is equal to or less than the upper limit value of the preferable range, it is possible to avoid the entire connecting portion cover 1 from becoming too large.

[0024] The inner surface of the portion constituting the connecting portion accommodating portion 40 of the semi-cylindrical body 10A and the semi-cylindrical body 10B is configured to follow the outer shape of the connecting portion. In the present embodiment, a central rib 43 extending in the circumferential direction is formed at the center of the inner surface of the portion constituting the connecting portion accommodating portion 40 of the semi-cylindrical body 10A and the semi-cylindrical body 10B. When the semi-cylindrical body 10A and the semi-cylindrical body 10B are in a closed state, the respective central ribs 43 are connected to form an annular shape.

[0025] When the semi-cylindrical body 10A and the semi-cylindrical body 10B are in a closed state, between the central rib 43 and the first boundary rib 44, a first pipe joint accommodating portion 41 is formed. Between the central rib 43 and the second boundary rib 45, a second pipe joint accommodating portion 42 is formed. Since the portion constituting the connecting portion accommodating portion 40 of the semi-cylindrical body 10A and the semi-cylindrical body 10B has such a shape, as shown in FIG. 2, the inside of the connecting portion accommodating portion 40 is adapted to follow the outer shape of the pipe joint 50 having a small diameter at both ends and the central portion.

[0026] As shown in FIGS. 1 and 3, on the outer surface of the portion constituting the connecting portion accommodating portion 40 of the semi-cylindrical body 10A and the semi-cylindrical body 10B, first recesses 46 extending in the circumferential direction are formed near the opposite surface of the first boundary rib 44. When the semi-cylindrical body 10A and the semi-cylindrical body 10B are in a closed state, the respective first recesses 46 are connected to form an annular shape.

[0027] Further, on the outer surface of the portion constituting the connecting portion accommodating portion 40 of the semi-cylindrical body 10A and the semi-cylindrical body 10B, second recesses 47 extending in the circumferential direction are formed near the opposite surface of the second boundary rib 45. When the semi-cylindrical body 10A and the semi-cylindrical body 10B are in a closed state, the respective second recesses 47 are connected to form an annular shape.

[0028] Further, on the outer surface at the center of the portion constituting the connecting portion housing portion 40 of the semi-cylindrical body 10A and the semi-cylindrical body 10B, central recesses 48 extending in the circumferential direction are formed on the opposite surface of the central rib 43. When the semi-cylindrical body 10A and the semi-cylindrical body 10B are in a closed state, the respective central recesses 48 are connected to form an annular shape.

[0029] Also, rectangular engaging pieces 23 and 24 are protruding from the end edges 12A of the portion constituting the first covering tube housing portion 20 of the semi-cylindrical body 10A, being spaced apart from each other. A cut 23a is formed on the side of the engaging piece 24 between the engaging piece 23 and the semi-cylindrical body 10A. A cut 24a is formed on the side of the engaging piece 23 between the engaging piece 24 and the semi-cylindrical body 10A.

[0030] Rectangular engaging pieces 33 and 34 are protruding from the end edges 12A of the portion constituting the second covering tube housing portion 30 of the semi-cylindrical body 10A, being spaced apart from each other. A cut 33a is formed on the side of the engaging piece 34 between the engaging piece 33 and the semi-cylindrical body 10A. A cut 34a is formed on the side of the engaging piece 33 between the engaging piece 34 and the semi-cylindrical body 10A.

[0031] Also, a rectangular engaging piece 25 is protruding from the end edge 12B of the portion constituting the first covering tube housing portion 20 of the semi-cylindrical body 10B. As will be described later, the engaging piece 25 is configured to engage between the engaging piece 23 and the engaging piece 24. A rectangular engaging piece 35 is protruding from the end edge 12B of the portion constituting the second covering tube housing portion 30 of the semi-cylindrical body 10B. As will be described later, the engaging piece 35 is configured to engage between the engaging piece 33 and the engaging piece 34.

[0032] The connecting portion cover 1 is made of a soft foamed resin. By being made of a soft foamed resin, the connecting portion cover 1 exhibits excellent heat insulation properties. Also, by being made of a soft foamed resin, the connecting portion cover 1 has appropriate elasticity. Therefore, the first rib 21 or the second rib 31 filled in the valley portion 74 is difficult to come out of the valley portion 74.

[0033] In addition, since the connecting part cover 1 is made of a soft foamed resin, the connecting part cover 1 has appropriate plasticity. Therefore, even if there are some dimensional errors when manufacturing the connecting part cover 1, the first rib 21 or the second rib 31 can be engaged with a plurality of valley parts 74 arranged continuously. The soft foamed resin may be any of styrofoam, polystyrene foam, polyurethane foam, polyethylene foam, phenol foam, etc.

[0034] [Manufacturing method of connecting cover] Since the connecting part cover 1 can be manufactured at low cost, it is preferable to manufacture it by press-molding a single sheet of soft foamed resin. The foaming ratio of the sheet-shaped soft foamed resin before press molding can be, for example, 5 to 50 times.

[0035] Since the foaming ratio is equal to or higher than the lower limit value of the preferable range, the heat retention property of the connecting part is enhanced. In addition, since the degree of freedom in molding increases, it is easy to improve the molding accuracy. Also, since it is easy to ensure appropriate flexibility of the connecting part cover 1, it is easy to improve the adhesion to the connecting part and its vicinity. Since the foaming ratio is equal to or lower than the upper limit value of the preferable range, it is easy to ensure the required strength.

[0036] [Pipe joint] As shown in FIG. 2, the pipe joint 50 in the connecting part of the present embodiment includes a first insertion port 51 which is an inlet into which the first inner pipe 61 is inserted, a second insertion port 52 which is an inlet into which the second inner pipe 62 is inserted, a first inner pipe insertion part 53 which is adjacent to the first insertion port 51 and has a larger diameter than the first insertion port 51, a second inner pipe insertion part 54 which is adjacent to the second insertion port 52 and has a larger diameter than the second insertion port 52, and a central part 55 which exists between the first inner pipe insertion part 53 and the second inner pipe insertion part 54 and has a smaller diameter than the first inner pipe insertion part 53 and the second inner pipe insertion part 54.

[0037] [Inner pipe] The first inner pipe 61 and the second inner pipe 62 to which the pipe joint 50 is connected are formed with a constant circular cross-section over the entire length and have flexibility. In the present embodiment, an example is shown in which the outer diameters of the first inner pipe 61 and the second inner pipe 62 are the same. The first inner pipe 61 is inserted from the first insertion port 51 to the first inner pipe insertion portion 53, and its tip reaches in front of the central portion 55. The second inner pipe 62 is inserted from the second insertion port 52 to the second inner pipe insertion portion 54, and its tip reaches in front of the central portion 55.

[0038] As the materials of the first inner pipe 61 and the second inner pipe 62, synthetic resins such as cross-linked polyethylene (PE-X), polybutene (PB), high heat-resistant polyethylene (PE-RT), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and polymethyl methacrylate (PMMA) can be used alone or in combination of two or more.

[0039] The first inner pipe 61 and the second inner pipe 62 may be those in which a plurality of resin layers are laminated in the radial direction. Further, a composite resin pipe containing a metal such as a metal-reinforced multi-layer structure may be used. The above is an example of the material of each inner pipe, and there is no particular limitation as long as it can ensure the required performance such as flexibility and fluid flowability.

[0040] [Corrugated coating pipe] In the present embodiment, the first inner pipe 61 and the second inner pipe 62 are each inserted into a corrugated coating pipe, and the outer periphery is covered by the corrugated coating pipe. In the present embodiment, the first inner pipe 61 is covered by the first corrugated coating pipe 71, and the second inner pipe 62 is covered by the second corrugated coating pipe 72. However, the end portion of the first inner pipe 61 inserted into the pipe joint 50 at the connection portion is exposed from the first corrugated coating pipe 71. Further, the end portion of the second inner pipe 62 inserted into the pipe joint 50 at the connection portion is exposed from the second corrugated coating pipe 72. The central axes of the first inner pipe 61 and the second inner pipe 62 are substantially arranged on a common axis with each other.

[0041] As shown in Fig. 4, the first corrugated covering tube 71 and the second corrugated covering tube 72 each have a bellows shape in which large-diameter peaks 73 and small-diameter valleys 74 are alternately formed. Although Fig. 4 shows the second corrugated covering tube 72, the first corrugated covering tube 71 also has a bellows shape in which peaks 73 and valleys 74 are alternately formed.

[0042] The first corrugated covering tube 71 and the second corrugated covering tube 72 are made of a flexible resin, preferably a single-layer soft foamed resin. From the viewpoints of suppressing sound and heat retention, the foaming ratio of the soft foamed resin is preferably from 1.05 times to 4 times, more preferably from 1.2 times to 2.5 times.

[0043] The soft foamed resin preferably has polyethylene as the main component (50 wt% or more) and contains less than 50 wt% of polypropylene. From the viewpoint of flexibility, low-density polyethylene (LDPE) is preferred as the main component polyethylene. Further, it is preferably contains a lubricant for ease of demolding and the like. The content of the lubricant with respect to the soft foamed resin is preferably 1 wt% or less. The above is an example of the materials of the first corrugated covering tube 71 and the second corrugated covering tube 72, and there is no particular limitation as long as the required performance such as flexibility and protection for the first inner tube 61 and the second inner tube 62 can be ensured.

[0044] [Relationship between the cover for the connecting portion and the vicinity of the connecting portion] Referring to Fig. 4, when the cover 1 for the connecting portion accommodates the connecting portion and its vicinity, the positional relationship of the cover 1 for the connecting portion with respect to these objects to be accommodated will be described in detail. As already described, the pitch of the second rib 31 is the same as the pitch of the valleys 74 of the first corrugated covering tube 71. Therefore, the second rib 31 engages continuously with a plurality of adjacent valleys 74.

[0045] In this embodiment, since three second ribs 31 are provided, the second ribs 31 are engaged continuously with three adjacent troughs 74 in the second corrugated covering tube 72. Similarly, the first rib 21 is also engaged continuously with three adjacent troughs 74 in the first corrugated covering tube 71.

[0046] When the connecting cover is made of a hard resin, even if a slight dimensional error occurs, it is difficult to engage the ribs continuously with a plurality of adjacent troughs. However, the connecting part cover 1 made of a soft foamed resin as in this embodiment has appropriate plasticity, so that even if some dimensional errors occur, it is possible to engage the ribs continuously with a plurality of adjacent troughs.

[0047] There is no particular limitation on the shapes of the first rib 21 and the second rib 31, and shapes such as a mountain shape, a rectangle, a trapezoid, and a triangle can be adopted as appropriate. A shape that is likely to adhere closely to the trough 74 of the corrugated covering tube is preferable. The higher the adhesiveness, the less likely air is to flow into the space between the connecting part cover 1 and the connecting part, so the heat retention property is enhanced. Also, since the engaging force with the trough 74 is increased, it is easy to prevent the first corrugated covering tube 71 and the second corrugated covering tube 72 from coming off the connecting part cover 1.

[0048] In order to obtain good adhesiveness, it is preferable that the shapes of the first rib 21 and the second rib 31 are the same as the shape of the trough 74 of the corrugated covering tube. For example, in the case of a trapezoidal trough 74, trapezoidal first rib 21 and second rib 31 are likely to obtain good adhesiveness. Also, as shown in FIG. 5, it is also preferable that the tip of the first rib 21 or the second rib 31 is a curved surface. When the tip of the rib is a curved surface, by pressing the connecting part cover 1 against the first corrugated covering tube 71, the second corrugated covering tube 72, etc., the tip of the rib is deformed in a direction to become flat and approaches the bottom of the trough 74, so that good adhesiveness is easily obtained.

[0049] In order to obtain good adhesion, it is preferable that the heights of the first rib 21 and the second rib 31 are equal to or greater than the depth of the trough portion 74. That is, the ratio [d3 / d6] of the height d3 of the rib (the first rib 21 or the second rib 31) to the depth d6 of the trough portion 74 is preferably 1 or more. When [d3 / d6] is 1 or more, the rib can easily fill substantially the entire trough portion 74, enhancing the heat retention property. Also, since the engaging force between the rib and the trough portion 74 increases, it is easy to prevent the disengagement from the connecting portion cover 1 of the first corrugated covering pipe 71, the second corrugated covering pipe 72, etc.

[0050] The ratio [d3 / d6] is preferably 1.5 or less, and more preferably 1.1 or less. If the ratio [d3 / d6] is 1.1 or less, it is possible to substantially prevent air from passing between the connecting portion cover 1 and the peak portion 73, enhancing the heat retention property. If the ratio [d3 / d6] is 1.5 or less, by pressing the connecting portion cover 1 against the first corrugated covering pipe 71, the second corrugated covering pipe 72, etc., the tip of the rib deforms in the direction of being crushed and the height of the rib shrinks, so it is easy to make the connecting portion cover 1 and the peak portion 73 in close contact.

[0051] In order to obtain good adhesion, it is preferable that the filling rate of the rib in the trough portion is 70% or more, and more preferably 80% or more. In this specification and the claims, the filling rate is obtained as the ratio of the cross-sectional area of the rib filled in the trough portion 74 to the cross-sectional area of the trough portion 74 in the cross-section along the axis of the corrugated covering pipe.

[0052] Here, the filling rate should originally be obtained in a state where the rib is engaged with the trough portion 74, but it is difficult to obtain each cross-sectional area in the filled state. Therefore, in this specification and the claims, the filling rate is taken as a value obtained by assuming that each shape in the state before engagement does not change and engages as it is.

[0053] Therefore, the cross-sectional area of the trough portion is the cross-sectional area of the portion surrounded by the plane connecting the adjacent peak portions 73 and the trough portion 74 before engagement. Further, the cross-sectional area of the rib filled in the valley portion 74 is the cross-sectional area of the portion that can be inserted into the valley portion 74 below the plane connecting the peak portions 73 adjacent to the rib, assuming that neither the rib nor the valley portion 74 is deformed at all.

[0054] In addition, for example, when the rib is trapezoidal with a width wider than that of the valley portion 74, when the cross-sectional views of the rib and the valley portion 74 are superimposed, if there is a portion protruding from the valley portion at the base end portion of the cross-section of the rib, the protruding portion is regarded as not being insertable into the valley portion 74 below the plane connecting the adjacent peak portions 73, and the cross-sectional area of the rib filled in the valley portion 74 is obtained without including the said portion. Also, when the rib is not wider than the valley portion 74 but its height exceeds the depth of the valley portion 74, when the cross-sectional views of the rib and the valley portion 74 are superimposed, if there is a portion protruding from the valley portion at the base end portion of the cross-section of the rib, the protruding portion is regarded as not being insertable into the valley portion 74 below the plane connecting the adjacent peak portions 73, and the cross-sectional area of the rib filled in the valley portion 74 is obtained without including the said portion.

[0055] Based on FIG. 6, the method for obtaining the filling rate when the cross-section of the rib is rectangular will be described. The cross-section of the valley portion 74 in FIG. 6 is an inverted trapezoid with the cross-sectional length d4 of the plane connecting the upper surfaces of the peak portions 73 on both sides as the upper base, the cross-sectional length d5 of the bottom surface of the valley portion 74 as the lower base, and the height being d6. Therefore, its cross-sectional area S0 is obtained by the following formula (1). S0=(d4 + d5)×d6 / 2 ···(1)

[0056] On the other hand, the cross-sectional area S1 of the first rib 21 with a cross-sectional length of d1 and a height of d3 (d3>d6) below the plane connecting the upper surfaces of the peak portions 73 on both sides is obtained by the following formula (2). S1 = d1×d6···(2) Therefore, the filling rate X1 is obtained by the following formula (3). X1 = S1 / S0 = d1×2 / (d4 + d5)···(3)

[0057] Next, based on FIG. 7, the method for obtaining the filling rate when the cross-section of the rib is a reverse trapezoid and it can be inserted until its tip contacts the bottom surface of the trough portion 74 will be described. The cross-sectional area of the trough portion 74 in FIG. 7 is obtained by the above formula (1) in the same manner as the cross-sectional area of the trough portion 74 in FIG. 6.

[0058] On the other hand, the cross-section that can be filled below the plane connecting the upper surfaces of the ridge portions 73 on both sides of the first rib 21 in FIG. 7 is a reverse trapezoid with the cross-sectional length d1 of the first rib 21 on the plane connecting the upper surfaces of the ridge portions 73 on both sides as the upper base, the cross-sectional length d2 of the tip contacting the bottom surface of the trough portion 74 as the lower base, and the height being d3 (d3 > d6). Therefore, its cross-sectional area S2 is obtained by the following formula (4). S2 = (d1 + d2) × d6 / 2 ···(4)

[0059] Therefore, the filling rate X2 is obtained by the following formula (5). X2 = S2 / S0 = (d1 + d2) / (d4 + d5)···(5) Based on FIGS. 6 and 7, the filling rate of the first rib 21 with respect to the trough portion 74 of the first corrugated coating tube 71 has been described. Needless to say, the filling rate of the second rib 31 with respect to the trough portion 74 of the second corrugated coating tube 72 can also be obtained in the same manner.

[0060] [Engaging portion] Next, with reference to FIGS. 8 to 10, the engagement state of the engaging piece provided on the end side 12A of the semi-cylindrical body 10A and the engaging piece provided on the end side 12B of the semi-cylindrical body 10B will be described in detail. As shown in FIGS. 8 and 9, the width a of the engaging piece 35 is made larger than the interval b between the engaging piece 33 and the engaging piece 34.

[0061] As already described, a cut 33a is formed on the side of the engaging piece 34 between the engaging piece 33 and the semi-cylindrical body 10A. A cut 34a is formed on the side of the engaging piece 33 between the engaging piece 34 and the semi-cylindrical body 10A. These cuts 33a and 34a each have a width c, and the relationship between a and c is as follows in formula (6). a ≒ b + 2 × c ···(6)

[0062] Therefore, as shown in FIG. 10, by inserting the engaging piece 35 between the engaging piece 33 and the engaging piece 34 while sandwiching the engaging piece 35 between the cut 33a and the cut 34a, the engaging piece 35 can be engaged with the engaging piece 33 and the engaging piece 34, and the end sides 12A and 12B in the portion constituting the second coating tube accommodating portion 30 can be fixed in a state where they are joined together.

[0063] The relationship between the engaging piece 25, the engaging piece 23, and the engaging piece 24 is the same. That is, the width a of the engaging piece 25 is made larger than the interval b between the engaging piece 23 and the engaging piece 24. Further, the cuts 23a and 24a each have a width c, and a to c are in the relationship of the above formula (6).

[0064] Therefore, by inserting the engaging piece 25 between the engaging piece 23 and the engaging piece 24 while sandwiching the engaging piece 25 between the cut 23a and the cut 24a, the engaging piece 25 can be engaged with the engaging piece 23 and the engaging piece 24, and the end sides 12A and 12B in the portion constituting the first coating tube accommodating portion 20 can be fixed in a state where they are joined together.

[0065] The width c is preferably 2 to 5 mm, and more preferably 3 to 4 mm. When the width c is equal to or greater than the lower limit value of the preferable range, the force for sandwiching and fixing the engaging piece 25 or the engaging piece 35 between the cuts becomes stronger. When the width c is equal to or less than the upper limit value of the preferable range, the engaging piece 23, the engaging piece 24, or the engaging piece 33, the engaging piece 34 is less likely to break from the semi-cylindrical body 10A.

[0066] When the end sides 12A and 12B in the portion constituting the first coating tube accommodating portion 20 and the portion constituting the second coating tube accommodating portion 30 are fixed in a state where they are joined together, the semi-cylindrical body 10A and the semi-cylindrical body 10B are in a closed state.

[0067] Note that the shape of the engaging piece is not limited to a rectangle, and shapes such as a mountain shape, a trapezoid, a triangle, and an arc can be appropriately adopted. However, in order to obtain a good engaging state, the engaging piece 25 and the engaging piece 35 are preferably rectangular.

[0068] [Method for Protecting the Connection Part] In order to protect the connection part by using the connection part cover 1 of the present embodiment, as shown in Fig. 2, the connection part and the first corrugated covering pipe 71 and the second corrugated covering pipe 72 in the vicinity thereof are arranged on either the semi-cylindrical body 10A or the semi-cylindrical body 10B.

[0069] At this time, since there are the first boundary rib 44 and the second boundary rib 45 (see Fig. 1), it can be easily aligned by arranging the pipe joint 50 between them. In addition, since the first corrugated covering pipe 71 and the second corrugated covering pipe 72 cannot be inserted inside the first boundary rib 44 and the second boundary rib 45, there is no concern of damaging the pipe joint 50 due to the end faces of the first corrugated covering pipe 71 and the second corrugated covering pipe 72.

[0070] Thereafter, by engaging the engaging piece 25 with the engaging pieces 23 and 24 and engaging the engaging piece 35 with the engaging pieces 33 and 34, as shown in Fig. 3, the semi-cylindrical body 10A and the semi-cylindrical body 10B are brought into a closed state. Thereby, the connection part can be protected by using the connection part cover 1, and the connection system of the present invention can be configured. In the present embodiment, since the semi-cylindrical body 10A and the semi-cylindrical body 10B are joined by the hinge part 11, the connection part can be easily accommodated.

[0071] In the present embodiment, it is further preferable to fix the connection part cover 1 in close contact with the connection part by one or both of the band and the sheet. Since the semi-cylindrical body 10A and the semi-cylindrical body 10B are already in a closed state by the engaging pieces, the fixing by the band or the sheet can be easily performed with one hand holding the connection part cover 1 and the other hand.

[0072] Fig. 11 shows an example of fixing with a covering sheet 81 and a binding band 82. The binding band 82 is preferably tightened at the positions of the first concave portion 46 and the second concave portion 47 of the connecting portion cover 1. Thereby, the binding band 82 can be used at an appropriate position, and the position of the binding band 82 can be prevented from shifting.

[0073] Fixing with one or both of the band and the sheet can reliably hold the closed state of the semi-cylindrical body 10A and the semi-cylindrical body 10B. In addition, the adhesion of the connecting portion cover 1 to the connecting portion is enhanced, so the heat retention property is further improved. Further, it is possible to more reliably prevent the first corrugated covering tube 71 and the second corrugated covering tube 72 from coming off from the connecting portion cover 1. Furthermore, it is easy to prevent the first corrugated covering tube 71 and the second corrugated covering tube 72 from being flattened and distorted.

[0074] [Other Embodiments] In the above embodiment, an example in which the semi-cylindrical body 10A and the semi-cylindrical body 10B are joined by the hinge portion 11 is shown, but the semi-cylindrical body 10A and the semi-cylindrical body 10B may be separable. The first boundary rib 44 and the second boundary rib 45 are not essential. The first concave portion 46 and the second concave portion 47 are also not essential.

Example

[0075] [Experimental Example 1] A connecting portion cover 1 with a substantially uniform thickness in the connecting portion housing portion 40 was created by varying the thickness, and its heat retention power was examined. As the first inner tube 61 and the second inner tube 62, cross-linked polyethylene tubes with an inner diameter of 12.9 mm and an outer diameter of 17.0 mm were each used with a length of 100 cm. As the first corrugated covering tube 71 and the second corrugated covering tube 72, a corrugated covering tube having an inverted trapezoid with a valley portion 74 having a cross-sectional area of 2.25 mm 2 (in Fig. 7, d4 = 2 mm, d5 = 1 mm, d6 = 1.5 mm) and a pitch of the valley portion 74 of 4.5 mm was used.

[0076] As the pipe joint 50, a pipe joint with a length of 70 mm and a diameter of 33 mm for the first pipe joint housing portion 41 and the second pipe joint housing portion 42 was used. For the first rib 21 and the second rib 31 of the cover 1 for the connecting portion, the width of the base end portion is 2 mm, and they are formed in a substantially trapezoidal shape with d1 = 1.75 mm, d2 = approximately 1 mm, and d3 = 2 mm in Fig. 7. Three ribs are provided at a pitch of 4.5 mm each. The filling rate was 91.7% for all of them.

[0077] The ends of the first inner pipe 61 and the second inner pipe 62 were each exposed 33 mm from the covering pipe, and the exposed portions were inserted into the pipe joint 50 to connect the first inner pipe 61 and the second inner pipe 62. Hot water at an initial temperature of 40 °C was flowed from the end of the first inner pipe 61 opposite to the end inserted into the pipe joint 50 to the end of the second inner pipe 62 opposite to the end inserted into the pipe joint 50 to fill the whole with hot water. Then, the flow of hot water was stopped, and the temperature of the water in the first inner pipe 61 was measured 30 minutes after the flow was stopped. The results are shown in Table 1.

[0078]

Table 1

[0079] From Table 1, it was confirmed that the higher the thickness of the cover for the connecting portion, the higher the heat retention performance. Also, it was confirmed that if the thickness of the cover for the connecting portion is 3 mm or more, sufficient heat retention performance for practical use can be obtained.

[0080] [Experimental Example 2] The cover 1 for the connecting portion was fabricated by variously changing the number of the first ribs 21 and the second ribs 31, and the difficulty of detachment of the first corrugated covering pipe 71 and the second corrugated covering pipe 72 was examined. As the first inner pipe 61, the second inner pipe 62, the first corrugated covering pipe 71, the second corrugated covering pipe 72, and the pipe joint 50, the same ones as in Experimental Example 1 were used.

[0081] The first rib 21 and the second rib 31 of the cover 1 for the connecting part were also trapezoids approximately reversed in shape with a width of 2 mm at the base end, d1 = 1.75 mm, d2 = approximately 1 mm, and d3 = 2 mm in Fig. 7, similar to those in Experimental Example 1, and the filling rate was 91.7% for all. The pitch when providing a plurality of the first ribs 21 and the second ribs 31 was 4.5 mm.

[0082] For the measurement of the tensile strength, the second coating tube housing part 30 of the cover 1 for the connecting part was fixed to the fixing base with tape and a binding band, a portion 40 mm away from the second coating tube housing part 30 of the second corrugated coating tube 72 was gripped with a gripping jig, and both were pulled in the axial direction under the condition of a speed of 5 mm / min. The maximum value of the strength until the corrugated coating tube came out from the last rib was taken as the tensile strength. The results are shown in Table 2.

[0083]

Table 2

[0084] From the results in Table 2, it was confirmed that the higher the number of ribs, the higher the tensile strength and the more difficult it was to come out. Also, it was confirmed that if the number of ribs was three or more, a practically sufficient tensile strength could be obtained.

[0085] [Experimental Example 3] The cover 1 for the connecting part was created by variously changing the filling rates of the first rib 21 and the second rib 31, and the difficulty of the first corrugated coating tube 71 and the second corrugated coating tube 72 coming out was examined. The filling rate in each example was changed by adjusting the height (d3 in Fig. 7) of the cross-sections of the first rib 21 and the second rib 31.

[0086] The same ones as those in Experimental Example 1 were used for the first inner tube 61, the second inner tube 62, the first corrugated coating tube 71, the second corrugated coating tube 72, and the pipe joint 50. The first rib 21 and the second rib 31 of the cover 1 for the connecting part were trapezoids approximately reversed in shape with a width of 2 mm at the base end, d2 = approximately 1 mm, and d3 = 0.2 - 2.25 mm in Fig. 7, and three were provided at a pitch of 4.5 mm.

[0087] A connecting portion was formed in the same manner as in Experimental Example 1, hot water at an initial temperature of 40°C was flowed in the same manner, and the temperature of the water in the first inner pipe 61 was measured after 30 minutes. Also, in the same manner as in Experimental Example 2, by axially pulling the second coating tube housing portion 30 of the connecting portion cover 1 and the second corrugated coating tube 72, the maximum value of the strength until the corrugated coating tube slipped out from the last rib was measured as the tensile strength. The results are shown in Table 3.

[0088]

Table 3

[0089] From the results in Table 3, it was confirmed that the higher the filling rate, the higher the heat retention, the higher the tensile strength, and the more difficult it was to slip out. Also, it was confirmed that when the filling rate was 70% or more, sufficient heat retention and tensile strength for practical use could be obtained.

Explanation of Reference Numerals

[0090] 1 Connecting portion cover 10A Semi-cylindrical body 10B Semi-cylindrical body 11 Hinge portion 20 First coating tube housing portion 21 First rib 23 Engaging piece 23a Cut 24 Engaging piece 24a Cut 25 Engaging piece 30 Second coating tube housing portion 31 Second rib 33 Engaging piece 33a Cut 34 Engaging piece 34a Cut 35 Engaging piece 40 Connecting portion housing portion 41 First pipe joint housing portion 42 Second pipe joint housing portion 43 Central rib 44 First boundary rib 45 Second boundary rib 46 First recess 47 Second recess 48 Central recess 50 Pipe joint 61 First inner pipe 62 Second inner pipe 71 First corrugated covering pipe 72 Second corrugated covering pipe 73 Crest portion 74 Trough portion

Claims

1. A cover for a connecting portion that protects a connecting portion in which an end portion of a first inner pipe exposed from a first corrugated covering pipe that is covered with a first corrugated covering pipe having large-diameter ridges and small-diameter valleys formed alternately and an end portion of a second inner pipe exposed from a second corrugated covering pipe that is covered with a second corrugated covering pipe having large-diameter ridges and small-diameter valleys formed alternately are inserted or externally fitted to a pipe joint, comprising a pair of semi-cylindrical bodies made of a soft foamed resin, and in a closed state where both end sides along the axial direction of the pair of semi-cylindrical bodies are closed together, a first covering pipe accommodating portion that accommodates the vicinity of the connecting portion of the first corrugated covering pipe, a second covering pipe accommodating portion that accommodates the vicinity of the connecting portion of the second corrugated covering pipe, and a connecting portion accommodating portion between the first covering pipe accommodating portion and the second covering pipe accommodating portion are configured to be formed, on the inner surface of the portion of the pair of semi-cylindrical bodies that constitutes the first covering pipe accommodating portion, a plurality of first ribs extending in the circumferential direction are formed at the same pitch as the valleys of the first corrugated covering pipe along the axial direction, the height of the plurality of first ribs is larger than the depth of each valley of the first corrugated covering pipe, and in the closed state, the corresponding first ribs of the pair of semi-cylindrical bodies are connected to form an annular shape and continuously engage with the valleys of the first corrugated covering pipe, and are configured to deform within the valleys and be in close contact with the valleys, on the inner surface of the portion of the pair of semi-cylindrical bodies that constitutes the second covering pipe accommodating portion, a plurality of second ribs extending in the circumferential direction are formed at the same pitch as the valleys of the second corrugated covering pipe along the axial direction, the height of the plurality of second ribs is larger than the depth of each valley of the second corrugated covering pipe, and in the closed state, the corresponding second ribs of the pair of semi-cylindrical bodies are connected to form an annular shape and continuously engage with the valleys of the second corrugated covering pipe, and are configured to deform within the valleys and be in close contact with the valleys. A cover for a connecting portion, characterized in that it is configured as such.

2. The cover for a connecting portion according to claim 1, wherein the filling rate of the plurality of first ribs in each valley of the first corrugated covering pipe is 70% or more, and the filling rate of the plurality of second ribs in each valley of the second corrugated covering pipe is 70% or more.

3. On the inner surface between the portion constituting the first coating tube accommodating portion and the portion constituting the connecting portion accommodating portion of the pair of semi-cylindrical bodies, first boundary ribs extending in the circumferential direction are respectively formed, and in the closed state, the first boundary ribs of the pair of semi-cylindrical bodies are configured to be connected to form an annular shape. On the inner surface between the portion constituting the second coating tube accommodating portion and the portion constituting the connecting portion accommodating portion of the pair of semi-cylindrical bodies, second boundary ribs extending in the circumferential direction are respectively formed, and in the closed state, the second boundary ribs of the pair of semi-cylindrical bodies are configured to be connected to form an annular shape. The cover for a connecting portion according to claim 1 or 2.

4. On the outer surfaces of the pair of semi-cylindrical bodies, recesses extending in the circumferential direction are respectively formed at a plurality of locations along the axial direction, and in the closed state, the recesses of the corresponding pair of semi-cylindrical bodies are configured to be connected to form an annular shape. The cover for a connecting portion according to any one of claims 1 to 3.

5. One end side along the axial direction of the pair of semi-cylindrical bodies is connected to form a hinge portion, and the other end side along the axial direction is configured to be openable and closable with respect to each other. The cover for a connecting portion according to any one of claims 1 to 4.

6. Engaging portions for engaging the mutually openable and closable end sides are formed at both axial ends of the pair of semi-cylindrical bodies. The cover for a connecting portion according to claim 5.

7. A method for manufacturing a cover for a connecting portion according to any one of claims 1 to 6, characterized by press molding a sheet-shaped soft foam resin. The method for manufacturing a cover for a connecting portion.

8. A connecting system characterized in that the connecting portion and its vicinity are accommodated in the cover for a connecting portion according to any one of claims 1 to 6.

9. After accommodating the connecting portion and its vicinity in the pair of semi-cylindrical bodies of the cover for a connecting portion according to any one of claims 1 to 6, a method for protecting a connecting portion, characterized by fixing the cover for a connecting portion to be in close contact with the connecting portion by one or both of a band and a sheet.

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