Protective tube

Abstract

To securely connect halved tubes to each other with a simple work even without any band for winding the halved tubes together and stably protect a cable.SOLUTION: Concave sides of a pair of halved tubes 2A and 2B are arranged to face each other to form a protective tube 1. Each of the halved tubes 2A and 2B includes a semi-cylindrical resin portion 4 and a cast iron portion 3 embedded in the resin portion 4 by insert molding. The cast iron portion 3 has an engagement portion for engaging the halved tubes 2A and 2B with each other. With this configuration, the pair of halved tubes 2A and 2B are connected to each other by the engagement portion consisting of the cast iron portion 3, and the presence of the cast iron portion 3 increases the specific gravity of the protective tube 1, which makes it easier for the protective tube 1 to sink to the bottom of the sea and makes the protective tube less susceptible to effects of tidal currents, etc. Therefore, the halved tubes 2A and 2B can be firmly connected to each other without any band, and the cable can be stably protected.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a protective tube that covers and protects a linear body such as a cable.

Background Art

[0002] Conventionally, cables laid or buried under the sea have been used as transmission lines for communication or power from island to island. In order to prevent such cables from being damaged by contact with rocky reefs or the like due to being washed by ocean currents and waves, or by contact with the bottom of passing ships or anchors dropped from ships, etc., their surroundings are covered and protected by a protective tube.

[0003] Such a protective tube is formed of, for example, polyurethane, sandwiches the cable from above and below with a pair of half-tube bodies, and wraps an annular band around the periphery of these half-tube bodies so that the half-tube bodies do not separate from each other (see, for example, Patent Document 1). However, such a band is likely to deteriorate or break when exposed to tidal currents or hit by sand or stones on the seabed. If the deteriorated or broken band breaks, the half-tube body (protective tube) may come off the cable.

[0004] Therefore, in addition to such a band, a protective tube provided with a fixing portion for connecting the half-tube bodies to each other is known (see, for example, Patent Document 2). This fixing portion is composed of a plurality of convex portions extending from one half-tube body toward the other half-tube body and a plurality of concave portions provided in the other half-tube body into which the convex portions are fitted when the pair of half-tube bodies are arranged opposite each other. Then, by meshing these plurality of convex portions and concave portions, the pair of half-tube bodies are connected, and further, by wrapping a band around the periphery of the connected half-tube bodies, the protective tube is prevented from coming off the cable.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, in the protective pipe described in the above Patent Document 2, since the fixing portion is formed of resin, the fixing portion alone cannot provide sufficient strength to connect and hold the pair of split pipe bodies together, and still requires the winding of a band. The winding of this band needs to be performed at a short pitch along the protective pipe, which is a very laborious task.

[0007] In addition, since the protective pipe is formed of a resin with a low specific gravity, it is difficult for the protective pipe to sink to the seabed due to buoyancy. Therefore, for example, when it is subjected to a strong tidal current, there is a risk that the protective pipe will float up, causing damage to the cable or displacement of the cable from the desired installation location, and it cannot be said that the cable can be stably protected.

[0008] The present invention aims to solve the above problems, and provides a protective pipe that can firmly connect the split pipe bodies to each other with a simple operation even without a band, and can stably protect the cable. [Means for Solving the Problems]

[0009] The present invention is a protective pipe formed by arranging the concave surfaces of a pair of split pipe bodies facing each other. Each of the pair of split pipe bodies includes a semi-cylindrical resin portion forming the main body of the split pipe body, and a cast iron portion embedded in the resin portion by insert molding. The cast iron portion has an engaging portion for engaging the pair of split pipe bodies with each other. The engaging portion has a hook-shaped portion protruding outside the resin portion toward the oppositely arranged split pipe bodies, and a fitting concave portion exposed from the resin portion and fitting with the hook-shaped portion.

[0010] It is preferable that the engaging portion prevents the pair of half pipe bodies from separating from each other by fitting the hook-shaped portion into the fitting concave portion and sliding one along the longitudinal direction of the half pipe body relative to the other.

[0011] It is preferable that a plurality of the cast iron portions are arranged along the longitudinal direction.

[0012] It is preferable that the resin portion and the cast iron portion have a mounting portion for a fastening member for preventing sliding of the pair of half pipe bodies in the longitudinal direction.

[0013] The resin portion has a connection convex portion and a connection concave portion used for connection with the adjacent half pipe body at one end and the other end in the longitudinal direction. The cast iron portion is formed in a semi-cylindrical shape as a whole. The engaging portion is arranged at the center of the cast iron portion and has a gutter-shaped portion extending from at least one end of the engaging portion. It is preferable that the gutter-shaped portion is embedded in the connection concave portion.

[0014] It is preferable that the pair of half pipe bodies are engaged with each other in a state shifted by a half pitch along the longitudinal direction.

[0015] It is preferable that the pair of half pipe bodies have the same shape as each other.

Advantages of the Invention

[0016] According to the protective pipe of the present invention, a pair of half pipe bodies are fastened together by an engaging portion made of cast iron, and the presence of the cast iron portion increases the specific gravity of the protective pipe, making the protective pipe more likely to sink to the seabed and less likely to be affected by tidal currents or the like. Therefore, the half pipe bodies can be firmly connected to each other without a band, and the cable can be stably protected.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0018] The protective pipe according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the protective pipe 1 has a long shape along a linear body L such as a cable, and covers and protects the outer periphery of the linear body L. The protective pipe 1 is composed of a plurality of half pipe bodies 2A that cover the linear body L from one direction (upward in the illustrated example) perpendicular to the longitudinal direction D thereof, and a plurality of half pipe bodies 2B that cover the linear body L from the direction opposite to these half pipe bodies 2A (downward in the illustrated example). The plurality of half pipe bodies 2A and 2B have the same shape as each other, and are linearly connected along the longitudinal direction D.

[0019] As shown in FIGS. 2 and 3, the semi-cylindrical body 2A includes a cast iron part 3 made of cast iron and a resin part 4 made of resin (for example, polyurethane resin). A plurality of cast iron parts 3 are linearly arranged at regular intervals along the longitudinal direction D. Note that the material of the cast iron part is not limited to cast iron as long as it has a strength and specific gravity equal to or higher than that of cast iron. The resin part 4 has a long shape along the longitudinal direction D and forms the main body of the semi-cylindrical body 2A. The cast iron part 3 is set in a mold for plastic injection molding, and the resin for forming the resin part 4 is filled therein, and then it is embedded in the resin part 4 by insert molding (see FIG. 3(d)). As the material of the resin part, for example, materials such as vinyl chloride, polycarbonate, polyethylene, and polyurethane are used. Both the cast iron part 3 and the resin part 4 are formed in a semi-cylindrical shape as if a cylinder is cut in half along the cylinder axis, and their respective cylinder axes are arranged to overlap.

[0020] As shown in FIGS. 4 and 5, the cast iron part 3 has a main body part 31 formed in a semi-cylindrical shape, recessed parts 32 provided at both ends in the circumferential direction C at the central part of the main body part 31 in the longitudinal direction D, and engaging parts 33 provided in the recessed parts 32. Each engaging part 33 is used for engaging with the semi-cylindrical body 2B, and has a hook-shaped part 34 provided on one end side in the longitudinal direction D and protruding toward the semi-cylindrical body 2B arranged oppositely, and a fitting concave part 35 provided on the other end side in the longitudinal direction D and fitting with the hook-shaped part 34 of the semi-cylindrical body 2B arranged oppositely. Further, the recessed part 32 has a mounting part (bolt hole) 36 provided between the hook-shaped part 34 and the fitting concave part 35 for mounting a fastening member (to be described later), and a notch part 37 formed by notching the main body part 31 so that the upper parts of the fitting concave part 35 and the bolt hole 36 are open.

[0021] The hook portion 34 is formed in a hook shape having a standing portion 34a erected in the circumferential direction C from the bottom surface of the recessed portion 32, and a claw portion 34b extending from the tip of the standing portion 34a along the longitudinal direction D to the side opposite to the fitting recess 35. The fitting recess 35 has a groove portion 35a formed in a groove shape along the longitudinal direction D so that the hook portion 34 can be fitted therein, and a contact portion 35b provided adjacent to the groove portion 35a on the side opposite to the hook portion 34. The contact portion 35b contacts the claw portion 34b of the semi-cylindrical body 2B when the semi-cylindrical bodies 2A and 2B are connected to each other, as will be described later.

[0022] When the distance from the claw portion 34b to the recessed portion 32 is d1 (see FIG. 5(b)) and the distance from the tip of the claw portion 34b to the standing portion 34a is d2, the thickness d3 of the groove portion 35a in the vertical direction is configured to be smaller than the distance d1. Further, the length d4 of the contact portion 35b along the longitudinal direction D is configured to be longer than the distance d2.

[0023] Further, the cast iron portion 3 has a gutter-shaped portion 38 extending from at least one end of the main body portion 31 in the longitudinal direction D so as to be adjacent to the engaging portion 33. The gutter-shaped portion 38 is formed in a semi-cylindrical shape coaxial and having the same diameter as the main body portion 31, and in the illustrated example, is provided at both ends of the main body portion 31 so that the engaging portion 33 is arranged at the center of the cast iron portion 3.

[0024] As shown in FIGS. 6 and 7, the resin portion 4 has a main body portion 41 having a semi-cylindrical shape, insertion holes 43, groove holes 44, and round holes 45 provided at both ends 42 in the circumferential direction C of the main body portion 41, and a notch portion 46 formed by notching the main body portion 41 so that the upper sides of these insertion holes 43, groove holes 44, and round holes 45 are open. The insertion hole 43 is provided for inserting the hook portion 34 of the cast iron portion 3, and the groove hole 44 and the round hole 45 are provided corresponding to the groove portion 35a and the bolt hole 36 of the cast iron portion 3, respectively. Thereby, the hook portion 34 protrudes outside the resin portion 4, and the groove portion 35a and the bolt hole 36 are exposed from the resin portion 4.

[0025] In addition, the resin part 4 has a connection convex part 47 and a connection concave part 48 that are used for connection with the adjacent half pipe bodies 2A at one end and the other end in the longitudinal direction D of the main body part 41, respectively. The connection convex part 47 is formed in a substantially semi-cylindrical shape extending from the main body part 41 along the longitudinal direction D, is coaxial with the main body part 41, and is configured to have a smaller diameter than the main body part 41. The connection concave part 48 is formed by hollowing out the inner circumference of the main body part 41 so that the connection convex part 47 of the adjacent half pipe body 2A can fit therein. The gutter-shaped part 38 of the cast iron part 3 is embedded in the connection concave part 48 (see FIGS. 2 and 3).

[0026] Next, with reference to FIG. 8, the procedure for assembling the half pipe bodies 2A and 2B to form the protective pipe 1 will be described. First, the connection convex part 47 of one half pipe body 2B is fitted into the connection concave part 48 of the other half pipe body 2B to linearly connect a plurality of half pipe bodies 2B to each other. Next, with the direction of the half pipe body 2A along the longitudinal direction D being opposite to that of the half pipe body 2B, that is, with the directions of the connection convex part 47 and the connection concave part 48 being reversed between the half pipe body 2A and the half pipe body 2B, the connection part J between the connection convex part 47 and the connection concave part 48 in the half pipe body 2B is straddled by the main body part 41 of the half pipe body 2A, and the concave (inner) surfaces of the half pipe bodies 2A and 2B are arranged to face each other.

[0027] Then, after the hook-shaped parts 34 of the half pipe bodies 2A and 2B are inserted into the groove parts 35a of the half pipe bodies 2B and 2A, respectively, so that the end parts 42 of the half pipe bodies 2A and 2B are in contact with each other, the half pipe body 2A is slid along the longitudinal direction D so that the claw part 34b of the hook-shaped part 34 abuts against the contact part 35b. Then, the connection concave part 48 of one half pipe body 2A fits into the connection convex part 47 of the adjacent half pipe body 2A, and the half pipe bodies 2A and 2B are engaged with each other in a state where they are displaced by approximately half a pitch along the longitudinal direction D.

[0028] The bolt holes 36, 36 of the split pipe bodies 2A, 2B are configured to communicate with each other when the split pipe bodies 2A, 2B are connected. The fastening member 5 includes a fixing bolt 51 and a nut 52. The fixing bolt 51 is inserted through the communicating bolt holes 36, 36, and the nut 52 is screwed onto the threaded portion of the fixing bolt 51 inserted through the bolt holes 36, 36. Thereby, the slide movement of the split pipe bodies 2A, 2B in the longitudinal direction D is prevented, and the fitting between the hook-shaped portion 34 and the fitting recess 35 and the connection between the connection convex portion 47 and the connection recess 48 are maintained.

[0029] As shown in FIG. 9, when assembling the protective pipe 1, if the orientation of the split pipe body 2A along the longitudinal direction D is the same as that of the split pipe body 2B, that is, if the orientations of the connection convex portion 47 and the connection recess 48 along the longitudinal direction D are the same for the split pipe body 2A and the split pipe body 2B, some of the hook-shaped portions 34 do not face the fitting recess 35 (indicated by the two-dot chain line), and the split pipe bodies 2A, 2B cannot be connected to each other.

[0030] According to the protective pipe 1 configured as described above, since the pair of split pipe bodies 2A, 2B are fastened by the robust engaging portion 33 made of the cast iron portion 3, the split pipe bodies 2A, 2B can be firmly connected to each other without winding a band around the protective pipe 1 to prevent the split pipe bodies 2A, 2B from separating in the opposite directions (vertical direction). Thereby, the winding of the band, which has been a great deal of trouble, becomes unnecessary, and the working efficiency can be significantly improved.

[0031] Also, due to the presence of the cast iron portion 3, the specific gravity of the protective pipe 1 becomes larger compared to the case where the protective pipe is made of only resin. Thereby, the protective pipe 1 easily sinks to the seabed without adding additives such as weights. Therefore, it is difficult for the protective pipe 1 to float due to the influence of ocean currents or the like, resulting in damage to the cable or displacement of the cable from the desired installation location, and the cable can be stably protected.

[0032] In addition, since the hook-shaped portion 34 can be fitted into the fitting recess 35 simply by sliding one of the split pipe bodies 2A and 2B along the longitudinal direction D with respect to the other, the split pipe bodies 2A and 2B can be connected to each other by a simple operation. And the fastening member 5 is for preventing the hook-shaped portion 34 from coming off the fitting recess 35 due to the split pipe bodies 2A and 2B sliding along the longitudinal direction D after the split pipe bodies 2A and 2B are connected to each other. It is not the case that the split pipe bodies 2A and 2B are connected to each other only by the fastening force of the fastening member 5. Therefore, as shown in FIG. 10, it is sufficient to attach the fastening member 5 to both ends of each of the split pipe bodies 2A and 2B, and the number of required fastening members 5 can be reduced compared to a conventional protective pipe (generally, six or more fastening members are required per split pipe body) that connects the split pipe bodies only by the fastening force of the fastening member. Thereby, the manufacturing cost of the protective pipe 1 and the labor required for fastening the fastening member 5 can be reduced. In FIG. 10, the fastening member 5 indicated by a circle fixes the split pipe body 2A, and the fastening member 5 indicated by a triangle fixes the split pipe body 2B.

[0033] In addition, since the split pipe bodies 2A and 2B are arranged with a shift of approximately half a pitch from each other along the longitudinal direction D, for example, even if the fastening member 5 accidentally falls off and one split pipe body 2A comes off the linear body L, the split pipe body 2B arranged opposite to the split pipe body 2A that has come off is still connected to the split pipe bodies 2A adjacent to both sides of the split pipe body 2A that has come off by the fastening member 5. Thereby, it is possible to prevent both of the split pipe bodies 2A and 2B from coming off the linear body L.

[0034] In addition, a plurality of cast iron parts 3 are provided for one split pipe body 2A, 2B, and the split pipe bodies 2A, 2B are connected to each other via a plurality of engaging portions 33. Thereby, not only can the separation of the split pipe bodies 2A and 2B in the facing direction (vertical direction) be surely prevented, but also the displacement of the split pipe bodies 2A and 2B in the lateral direction (a direction orthogonal to both the vertical direction and the longitudinal direction D, the radial direction) can be prevented.

[0035] In addition, since the plurality of cast iron parts 3 are connected to each other by the resin part 4 having flexibility, the protective pipe 1 can be bent at the resin part 4, and the laying freedom of the linear body L can be increased, such as naturally curving the linear body L. On the other hand, since the connection recess 48 is reinforced by the cast iron part 3 when the gutter-shaped part 38 is embedded in the connection recess 48, the connection between the connection convex part 47 and the connection recess 48 can be made more reliable while allowing a predetermined flexibility at the connection part J between the half pipe bodies 2A or 2B.

[0036] Furthermore, since the half pipe bodies 2A and 2B have the same shape as each other, the labor of distinguishing the half pipe bodies 2A and 2B one by one when assembling the protective pipe 1 can be saved, and the working efficiency can be improved. In addition, since the half pipe bodies 2A and 2B can be insert-molded with one type of mold, the manufacturing cost can be reduced.

[0037] Note that the protective pipe according to the present invention is not limited to the above embodiment, and various modifications are possible. As the material of the cast iron part, for example, stainless steel or the like having a strength and specific gravity equal to or higher than that of cast iron may be used. In addition, the fitting between the hook-shaped part and the fitting recess may be performed by pushing the half pipe body instead of sliding the half pipe body. Also, the number of cast iron parts in each half pipe body may be appropriately determined according to the length of the half pipe body, and may be 2 - 3 pieces or 5 pieces or more. In order to prevent the rotation of the half pipe body, it is preferable that the number of cast iron parts is plural. Further, the fastening member does not necessarily have to be constituted by fixing bolts and nuts, and may be constituted by, for example, a pin inserted into the mounting part (bolt hole). Furthermore, the pair of half pipe bodies do not necessarily have to have the same shape as each other, and may have different shapes from each other.

Explanation of Reference Numerals

[0038] 1 Protective pipe 2A, 2B Half pipe bodies 3 Cast iron part 33 Engaging part 34 Hook-shaped part 35 Fitting recess 36 Bolt hole (mounting part) 38 Gutter-shaped part 4 Resin part 47 Connection convex part 48 Connection concave part 5 Fastening member D Longitudinal direction

Claims

1. A protective pipe formed by arranging the concave sides of a pair of split pipe bodies to face each other, Each of the pair of split pipe bodies includes a semi-cylindrical resin part forming the main body of the split pipe body and a cast iron part embedded in the resin part by insert molding, The cast iron part has an engaging part for engaging the pair of split pipe bodies with each other, The engaging part has a hook-shaped part protruding outside the resin part toward the oppositely arranged split pipe bodies and a fitting concave part exposed from the resin part and fitting with the hook-shaped part, and is characterized by a protective pipe.

2. The engaging part is characterized in that, by fitting the hook-shaped part into the fitting concave part and sliding one of the pair of split pipe bodies relative to the other along the longitudinal direction of the split pipe body, the separation between the pair of split pipe bodies is prevented, as described in claim 1.

3. The cast iron part is characterized in that a plurality of the cast iron parts are arranged along the longitudinal direction, as described in claim 2.

4. The resin part and the cast iron part have a mounting part for a fastening member for preventing sliding of the pair of split pipe bodies in the longitudinal direction, as described in claim 2.

5. The resin part has a connection convex part and a connection concave part used for connection with an adjacent split pipe body at one end and the other end in the longitudinal direction, The cast iron part is formed in a semi-cylindrical shape as a whole, the engaging part is arranged at the center of the cast iron part, and has a gutter-shaped part extending from at least one end of the engaging part, The gutter-shaped part is characterized in that it is embedded in the connection concave part, as described in claim 2.

6. The pair of split pipe bodies are characterized in that they are engaged with each other in a state of being shifted by a half pitch along the longitudinal direction, as described in claim 2.

7. The pair of half pipe bodies have the same shape as each other, and the protective pipe according to any one of claims 1 to 6 is characterized in that.

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