Protective tube

Abstract

In a protective tube formed by arranging the concave sides of a pair of halved pipes facing each other, the operability when connecting the protective tubes is improved. [Solution] The protective pipe 1 covers the linear body L from two directions by arranging a pair of split pipe bodies 2 facing each other. Each split pipe body 2 has an engaging portion for engaging with the opposing split pipe body 2, and multiple split pipe bodies are connected along the extension direction D of the linear body L. The split pipe body 2A that covers one side of the linear body L and the split pipe body 2B that covers the other side are arranged with a half-pitch offset from each other. With this configuration, the split pipe bodies 2 that cover the linear body L from one side and the other side are connected alternately, so the split pipe bodies 2 are less likely to fall off, and the workability when installing the protective pipe 1 is good.

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 on the seabed have been used as transmission lines for communication or power from island to island. Such cables are generally covered and protected by a protective tube around them in order to prevent damage caused by contact with rocky reefs or the like due to being washed by ocean currents and waves, or contact with the bottom of passing ships or anchors lowered from ships.

[0003] Such a protective tube is formed, for example, by sandwiching a cable from above and below with a pair of half tube bodies formed in a substantially semi-cylindrical shape and connecting the half tube bodies to each other with a connecting member (see, for example, Patent Document 1). Adjacent protective tubes are connected to each other via connection portions provided at both ends of each.

[0004] The connection portion is composed of, for example, a first enlarged diameter portion provided at one end of the protective tube and having a larger diameter, and a second enlarged diameter portion provided at the other end of the protective tube and having a larger diameter than the first enlarged diameter portion. Then, with the second enlarged diameter portion of the rear protective tube covering the first enlarged diameter portion of the previous protective tube, the half tube bodies forming the rear protective tube are connected with a connecting member, whereby the rear protective tube is connected to the previous protective tube.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the protective conduit described in Patent Document 1, when connecting the rear protective conduit to the front protective conduit, the halved pipe bodies forming the rear protective conduit are not connected to each other until the connecting member is attached. Therefore, unless the halved pipe bodies are held together by hand until the connecting member is attached, there is a risk that the halved pipe bodies will fall off the cable, and the workability when installing the protective conduit is not good.

[0007] The present invention aims to solve the above problems and to provide a protective pipe that offers good workability when being installed. [Means for solving the problem]

[0008] The present invention provides a protective tube for covering a linear body from two directions by arranging a pair of halved tubes with their concave sides facing each other, wherein each halved tube has an engaging portion for engaging with an opposing halved tube, and a plurality of them are connected along the extension direction of the linear body, and the halved tubes covering one side of the linear body and the halved tubes covering the other side are arranged with a half-pitch offset from each other.

[0009] The aforementioned split pipe body has a resin portion formed in a substantially semi-cylindrical shape and forming the main body of the split pipe body, and a metal portion embedded in the resin portion by insert molding, and it is preferable that the engaging portion is provided on the metal portion.

[0010] Preferably, the engaging portion has a hook-shaped portion that protrudes outward from the resin portion toward the opposing half-tube body, and a fitting portion that is exposed from the resin portion and fits with the hook-shaped portion, wherein the hook-shaped portion has a barb portion provided near its hook tip, and the fitting portion has a barb receiving portion that engages with the barb portion.

[0011] Preferably, the engaging portion has a protrusion that extends toward the opposing hook-shaped portion near the fitting portion, and a recess that abuts against the opposing protrusion near the hook-shaped portion.

[0012] The hook-shaped portion is positioned at one end of the resin portion, and it is preferable that the hook tip of the hook-shaped portion of one of the split tubes is inserted into the fitting portion of the other split tube, and then the one split tube is rotated to bring it closer to the other split tube to engage with the fitting portion.

[0013] The resin portion has a forward inclined portion at the leading end in the extension direction, where the concave side extends diagonally, and a rearward inclined portion at the rear end in the extension direction, where the convex side is diagonally recessed. The rearward inclined portion has a gentler slope than the forward inclined portion, and it is preferable that there is a gap between the forward rearward inclined portion and the rearward forward inclined portion in adjacent half-tube bodies in the extension direction.

[0014] The resin portion has a body made of a long semi-cylindrical body and a pair of edges that form both edges of the body in the extension direction and are the contact surfaces with the opposing half-tube body, and it is preferable that the fitting portion is exposed from the resin portion only on the edge side.

[0015] The resin portion has a connecting portion for connecting adjacent half-tube bodies in the extension direction, and the connecting portion has a connecting projection that is semi-cylindrical in shape and smaller in diameter than the outer circumference of the resin portion at the rear end in the extension direction, and a connecting recess that is recessed in the inner circumference of the resin portion at the front end in the extension direction and fits into the connecting projection of the adjacent half-tube body in the extension direction, and preferably the connecting projection has a projection provided along the circumferential direction at the end of its outer circumference, and the connecting recess has a recess on its inner circumference into which the projection fits.

[0016] Preferably, the connecting projection has a raised ridge on its outer circumference that is aligned with the direction of extension. [Effects of the Invention]

[0017] According to the protective pipe of the present invention, since the halved pipe bodies that cover the cable from one side and the other side are connected alternately with a half-pitch offset, one of the halved pipe bodies is less likely to fall off when installing the protective pipe, improving work efficiency.

Brief Description of the Drawings

[0018] [Figure 1] Perspective view showing a state where a protective tube according to an embodiment of the present invention is attached to a linear body. [Figure 2] (a)(b) are perspective views of the half tube bodies constituting the protective tube. [Figure 3] (a) is a side view of the half tube body, and (b) is a plan view of the half tube body. [Figure 4] (a) is a perspective view of the first metal part constituting the half tube body, and (b) is a side view of the first metal part. [Figure 5] (a) is a perspective view of the second metal part constituting the half tube body, and (b) is a side view of the second metal part. [Figure 6] (a) is a perspective view showing the operation when connecting the half tube body to the protective tube, and (b) is a side view showing the operation. [Figure 7] (a) is a perspective view showing the operation when connecting the half tube body to the protective tube, and (b) is a side view showing the operation. [Figure 8] (a) is a perspective view showing the operation when connecting the half tube body to the protective tube, (b) is a side view showing the operation, and (c) is an enlarged side view of the engaging part. [Figure 9] (a) is a side view showing the state where the protective tube is bent in one direction and a partial enlarged view thereof, and (b) is a side view showing the state where the protective tube is bent in two directions and a partial enlarged view thereof. [Figure 10] (a) is a perspective view of the half tube body according to the first modification of the above embodiment, and (b)(c) are side views showing the operation when connecting the half tube body to the protective tube. [Figure 11] (a) is a perspective view of the half tube body according to the second modification of the above embodiment, and (b)(c) are side views showing the operation when connecting the half tube body to the protective tube. [Figure 12] (a) is a perspective view of the half tube body according to the third modification of the above embodiment, and (b)(c) are side views showing the operation when connecting the half tube body to the protective tube. [Figure 13](a) is a perspective view of a split pipe body according to a fourth modified example of the above embodiment, and (b) and (c) are side views showing the operation when connecting the said split pipe body to a protective pipe. [Figure 14] (a) is a perspective view of a split pipe body according to a fifth modified example of the above embodiment, and (b) and (c) are side views showing the operation when connecting the said split pipe body to a protective pipe. [Figure 15] (a) to (c) are perspective views of a split pipe body relating to a sixth modified example of the above embodiment. [Modes for carrying out the invention]

[0019] A protective tube according to one embodiment of the present invention will be described with reference to the drawings. As shown in Figure 1, the protective tube 1 has a long shape along the linear body (cable) L and covers and protects the outer circumference of the linear body L. The protective tube 1 covers the linear body L from two directions by arranging the concave sides of a pair of split tube bodies 2 facing each other. In the illustrated example, it is composed of a plurality of split tube bodies 2A that cover the linear body L from above and a plurality of split tube bodies 2B that cover the linear body L from below.

[0020] The split tubes 2A and 2B are connected in multiples along the extension direction D of the linear body L, and are positioned with a half-pitch offset from each other. The split tubes 2A and 2B have the same shape, and below they will sometimes be referred to collectively as split tube 2. Also below, the direction perpendicular to the extension direction D, from split tube 2A to split tube 2B, will be called the vertical direction V according to the diagram example, the direction perpendicular to the vertical direction V will be called the radial direction R, the left side of the paper along the extension direction D will be called the front, and the direction toward the right side of the paper will be called the rear.

[0021] As shown in Figures 2 and 3, the split pipe body 2 includes a resin part 3 that forms the main body of the split pipe body 2, and metal parts (first metal part 4 and second metal part 5) embedded in the resin part 3 by insert molding. The resin part 3 is made of a flexible resin such as polyurethane, and the first metal part 4 and the second metal part 5 are made of metal such as stainless steel or cast iron. The resin part 3 is formed in a substantially semi-cylindrical shape and has a body part 31 which is a long semi-cylindrical body, and a pair of edge parts 32 which form both edges of the body part 31 in the extension direction D and become contact surfaces with the opposing split pipe bodies 2A and 2B. The edge parts 32 have a flat part parallel to the radial direction R. The first metal part 4 is located at the leading end of the resin part 3 in the extension direction D, and the second metal part 5 is located approximately in the center of the resin part 3.

[0022] The resin portion 3 has a forward inclined portion 33 at its forward end where the concave side extends diagonally (the body portion 31 protrudes more than the edge portion 32 in the extension direction D), and a rearward inclined portion 34 at its rear end where the convex side is obliquely recessed (the edge portion 32 protrudes more than the body portion 31 in the extension direction D). The rearward inclined portion 34 is configured to have a slightly gentler slope than the forward inclined portion 33. The split pipe bodies 2 are arranged in a series along the extension direction D such that the forward inclined portion 33 faces the rearward inclined portion 34 of the adjacent split pipe body 2 in the extension direction D.

[0023] Furthermore, the resin part 3 is provided with a connecting part 6 for connecting adjacent split pipe bodies 2 in the extension direction D. The connecting part 6 is composed of a connecting projection 61 that protrudes from the rear end of the resin part 3 along the extension direction D, and a connecting recess 62 that is recessed in the inner circumference of the resin part 3 at the front end of the resin part 3.

[0024] The connecting projection 61 has a semi-cylindrical portion 63 formed coaxially with the resin portion 3 and with a smaller diameter than the outer circumference of the resin portion 3, and a projection 64 and a ridged portion 65 provided on the outer circumference of the semi-cylindrical portion 63. The projection 64 is provided at the rear end of the semi-cylindrical portion 63 along the circumferential direction C of the resin portion 3 (see Figure 2(a)) and protrudes in a direction perpendicular to the extension direction D. The ridged portion 65 has a shape that is raised along the extension direction D on the body of the semi-cylindrical portion 63.

[0025] The connecting recess 62 abuts against the outer circumference of the connecting projection 61 of an adjacent half-pipe 2 when multiple half-pipe 2 are arranged adjacently along the extension direction D with the forward-sloping portion 33 facing the rearward-sloping portion 34. The connecting recess 62 also has a recessed portion 66 on its inner circumference that is recessed along the circumferential direction C. The projection 64 of the abutting connecting projection 61 fits into the recessed portion 66. Furthermore, the connecting recess 62 is reinforced by the first metal portion 4.

[0026] Furthermore, the resin portion 3 has a pair of protrusions 35 and a pair of grooves 36 provided on each edge portion 32. In the illustrated example, the protrusions 35 are provided between the connecting projection 61 and the second metal portion 5, and the grooves 36 are provided between the connecting recess 62 and the second metal portion 5. The protrusions 35 fit into the grooves 36 of the opposingly arranged split pipe body 2.

[0027] The first metal part 4 and the second metal part 5 have engaging parts for engaging with the opposing split pipe body 2. The engaging part consists of a pair of hook-shaped parts 41 provided on the first metal part 4 and a pair of fitting parts 51 provided on the second metal part 5 into which the hook-shaped parts 41 are fitted.

[0028] The first metal part 4 has a main body 42 that is formed in a generally semi-cylindrical shape, and the hook-shaped part 41 protrudes out of the resin part 3 toward the split pipe 2 which is positioned opposite from the leading end of the main body 42. The hook-shaped parts 41 have the same shape as each other and are formed in a flat claw shape that widens along the extension direction D and the vertical direction V. The hook-shaped part 41 extends such that its hook tip 43 protrudes further in the extension direction D than the base part 44 and is formed in a curved shape toward the leading inclined part 33.

[0029] The second metal part 5 has a main body 52 formed in a substantially semi-cylindrical shape as a whole, a pair of first claws 53 provided at the leading end of the main body 52, and a pair of second claws 54 provided at the rear end of the main body 52. ​​The fitting part 51 consists of a groove sandwiched between the first claws 53 and the second claws 54, is exposed from the resin part 3, and has the same shape as each other.

[0030] As shown in Figure 4, the hook-shaped portion 41 of the first metal portion 4 has a barb portion 46 provided on the end face 45 opposite to the forward inclined portion (not shown) of the resin portion, and a recess 48 provided on the end face 47 opposite to the end face 45. The barb portion 46 is provided near the hook tip 43 and is formed as a projection extending vertically along V from approximately the center of the end face 45. The recess 48 is provided on the rear end of the end face 47 opposite to the hook tip 43 and has a shape that is recessed vertically along V from the end face 47. In addition, the main body portion 42 is provided with a plurality of holes 49. By providing the holes 49, the amount of metal material used in the manufacture of the first metal portion 4 is reduced, and the integration with the resin portion 3 is improved when it is insert-molded into the resin portion 3.

[0031] As shown in Figure 5, the fitting portion 51 of the second metal part 5 has a shape complementary to the hook-shaped portion 41. The first claw portion 53 is formed in a flat claw shape that expands along the extension direction D and the vertical direction V, and its hook tip 55 is positioned to face the fitting portion 51. The end face 56 of the first claw portion 53 opposite the fitting portion 51 is provided with a barb receiving portion 57 that is formed in a projection shape that extends along the vertical direction V. The barb receiving portion 57 engages with the barb portion 46 of the hook-shaped portion 41 when the hook-shaped portion 41 is fitted into the fitting portion 51. The second claw portion 54 is formed in a flat plate shape that expands along the extension direction D and the vertical direction V, and has a convex portion 58 that protrudes along the vertical direction V on its body. In addition, the main body portion 52 of the second metal part 5 is also provided with a plurality of holes 59, similar to the first metal part 4.

[0032] The first metal part 4 and the second metal part 5 are covered by the resin part 3 by insert molding, with the hook-shaped part 41 and the fitting part 41 exposed from the edge 32 of the resin part 3. The fitting part 41 is exposed from the resin part 3 only on the edge 32 side and not on the radial R side. Therefore, when the opposing half-pipe bodies 2A and 2B are engaged and their edges 32 are in contact with each other, the metal hook-shaped part 41 and the fitting part 51 are completely covered by the resin part 3 of the opposing half-pipe bodies 2A and 2B and are not exposed to the outside. As a result, there is no risk of the metal parts being worn away by gravel, rocks, etc. after the protective pipe 1 is installed, and the cable can be protected stably for a long period of time.

[0033] Next, the procedure for forming a protective tube 1 by combining multiple halved pipe bodies 2 will be described. Figures 6 to 8 show the process of extending the protective tube 1 by connecting further halved pipe bodies 2A to the protective tube 1 already attached to the linear body L.

[0034] As shown in Figure 6, first, the hook-shaped portion 41 of the split pipe body 2A that is about to be connected is brought closer to the fitting portion 51 of the split pipe body 2B located at the rear end of the protective pipe 1, thereby bringing the split pipe body 2A closer to the protective pipe 1. Then, as shown in Figure 7, with the hook tip 43 of the hook-shaped portion 41 of the split pipe body 2A inserted into the fitting portion 51 of the split pipe body 2B (see Figure 7(b)), the split pipe body 2A is rotated using the engaging portion (hook-shaped portion 41 and fitting portion 51) as a pivot axis to bring it closer to the split pipe body 2B.

[0035] As a result, as shown in Figure 8, the hook-shaped portion 41 fits into the fitting portion 51, and the split pipe bodies 2A and 2B are brought into close contact with each other with their respective edges 32 touching (see Figure 8(b)). In the extension direction D, adjacent split pipe bodies 2A are connected when the connecting recess 62 of the newly connected split pipe body 2A fits into the connecting protrusion 61 of the adjacent split pipe body 2A. The fitting portion 51 of the newly connected split pipe body 2A engages with the hook-shaped portion 41 of the next split pipe body 2B (not shown) to be connected. The next split pipe body 2B is connected in the same manner as above, and thereafter, the protective pipe 1 is extended along the linear body L by connecting the split pipe bodies 2A and 2B alternately.

[0036] In this way, the protective pipe 1 has halved pipe bodies 2A and 2B that cover the linear body L from one side and the other side, connected alternately. The connected halved pipe bodies 2A and 2B are connected to each other by engaging parts and at the same time connected to adjacent halved pipe bodies 2A and 2B in the extension direction D by connecting parts 6. Therefore, the halved pipe bodies 2A and 2B are less likely to fall off when forming the protective pipe 1, and the workability when installing the protective pipe 1 can be improved.

[0037] At this time, the projection 64 of the connecting projection 61 fits into the recess 66 of the adjacent split pipe 2 in the extension direction D. This prevents the split pipe 2 from shifting position along the extension direction D. This shifting position is also prevented by the projection 35 fitting into the groove 36 of the opposing split pipe 2.

[0038] Furthermore, the protruding portion 65 of the connecting projection 61 acts to push up the connecting recess 62 when the connecting recess 62 comes into contact with the outer circumference of the connecting projection 61. As a result, the hook-shaped portion 41 is also pushed up along with the connecting recess 62, and the end face 45 of the hook-shaped portion 41 is pressed firmly against the fitting portion 51 (see Figure 8(c)). This strengthens the engagement between the hook-shaped portion 41 and the fitting portion 51.

[0039] Furthermore, since the rearward inclined portion 34 has a gentler slope than the forward inclined portion 33, and there is a gap between the rearward inclined portion 34 and the forward inclined portion 33, when rotating and connecting the split pipe bodies 2A, the forward inclined portion 33 of the split pipe body 2A is less likely to interfere with the rearward inclined portion 34 of the adjacent split pipe body 2A, allowing the split pipe bodies 2A to be connected smoothly (see Figures 7(b) and 8(b)).

[0040] Furthermore, when the hook-shaped portion 41 is fitted into the fitting portion 51, the barb portion 46 and recess portion 48 of the hook-shaped portion 41 are configured to engage with the barb receiving portion 57 and the convex portion 58 that protrude toward the hook-shaped portion 41 in the vicinity of the fitting portion 51 (see Figure 8(c)). As a result, the barb portion 46, recess portion 48, barb receiving portion 57, and convex portion 58 function as a locking mechanism to prevent the hook-shaped portion 41 from coming off the fitting portion 51.

[0041] Since the resin part 3 that forms the main body of the split pipe body 2 is flexible, the protective pipe 1 can be deformed by external force. Therefore, in the protective pipe 1 of this embodiment, a locking mechanism prevents the hook-shaped part 41 from coming off the fitting part 51 even when the protective pipe 1 is deformed by external force. Figure 9(a) shows the protective pipe 1 in a state where it is bent in one direction. In this example, a tensile load is generated between adjacent split pipe bodies 2A that pulls the split pipe bodies 2A apart, and a compressive load is generated between adjacent split pipe bodies 2B that brings the split pipe bodies 2B closer together.

[0042] In this case, at the engagement point where a tensile load is generated (see the enlarged view on the left), the hook-shaped portion 41 attempts to move so as to disengage from the fitting portion 51. However, the convex portion 58 engages with the concave portion 48, preventing the hook-shaped portion 41 from disengaging from the fitting portion 51. On the other hand, at the engagement point where a compressive load is generated (see the enlarged view on the right), the hook tip 43 of the hook-shaped portion 41 is strongly pressed against the fitting portion 51, strengthening the engagement between the hook-shaped portion 41 and the fitting portion 51. Furthermore, because the hook-shaped portion 41 is formed in a curved shape, when a load is applied that separates the halved pipe bodies 2A and 2B from each other, the load in the thrust direction is suppressed.

[0043] Furthermore, as shown in Figure 9(b), when the protective tube 1 is bent in two directions (S-shape), a rotational load is generated that causes the protective tube 1 to twist along the extension direction D, which may cause the protrusion 58 to detach from the recess 48 (see enlarged view). However, even in such a case, the barb portion 46 engages with the barb receiving portion 57, preventing the hook-shaped portion 41 from detaching from the fitting portion 51.

[0044] Thus, the locking mechanism functions to maintain the engagement between the hook-shaped portion 41 and the fitting portion 51. On the other hand, the locking mechanism does not prevent the hook-shaped portion 41 from engaging with the fitting portion 51 due to rotational movement, nor does it prevent the hook-shaped portion 41 from disengaging from the fitting portion 51 due to the reverse rotational movement.

[0045] In the protective conduit 1 configured as described above, the split pipe bodies 2A and 2B that cover the cable from one side and the other side are connected alternately with a half-pitch offset. This makes it less likely for one of the split pipe bodies 2 to fall off when installing the protective conduit 1, thus improving work efficiency. In the diagram used in the above explanation, one split pipe body 2A is shown above and the other split pipe body 2B is shown below. However, in actual installation, the arrangement is not limited to the vertical arrangement shown in the diagram. For example, one split pipe body 2A may be placed on the left and the other split pipe body 2B on the right, or they may be placed horizontally.

[0046] Furthermore, in the protective pipe 1, the main body of the split pipe body 2 is made of resin 3, making it lighter than a metal protective pipe and offering excellent transportability on land. On the other hand, the engaging parts that connect the opposing split pipe bodies 2A and 2B are made of sturdy metal parts (first metal part 4 and second metal part 5), allowing the split pipe bodies 2A and 2B to be firmly engaged with each other. Moreover, since the hook-shaped part 41 of the first metal part 4 is fitted into the fitting part 51 of the second metal part 5, the split pipe bodies 2A and 2B can be connected to each other without the need for connecting members such as bolts or pins, or bands wrapped around the protective pipe to prevent the split pipe bodies from separating. As a result, the installation of connecting members and bands, which were a major hassle with conventional protective pipes, is eliminated, improving work efficiency when installing the protective pipe 1.

[0047] Furthermore, by using the first metal part 4 and the second metal part 5, the specific gravity of the protective tube 1 is increased compared to when the protective tube is made of resin alone. As a result, the protective tube 1 sinks more easily without the need to add weights, making it less likely to float up from the seabed even when affected by currents. This suppresses cable damage due to floating and displacement of the cable from its installation location, thus providing stable protection for the cable.

[0048] Furthermore, since the resin part 3 is made of a flexible material, the protective tube 1 can be bent, increasing the freedom of laying the linear body L, such as allowing the linear body L to curve naturally. On the other hand, since the connecting recess 62 is reinforced by the first metal part 4, the connecting part 6, which is composed of the connecting protrusion 61 and the connecting recess 62, can reliably connect the halved pipe bodies 2A or 2B to each other while allowing the desired flexibility.

[0049] Furthermore, since the split tube bodies 2A and 2B have the same shape, the effort of distinguishing between the split tube bodies 2A and 2B each time when forming the protective tube 1 is eliminated, improving the efficiency of the assembly work of the protective tube 1. In addition, since the split tube bodies 2A and 2B can be insert-molded using one type of mold, manufacturing costs can be reduced.

[0050] Next, protective tubes according to other embodiments will be described with reference to Figures 10 to 15. These protective tubes according to these embodiments differ from the protective tube 1 described above mainly in the shape of the hook-shaped portion 41 and / or fitting portion 51.

[0051] Figure 10 shows a first modified example. As shown in Figure 10(a), in the split pipe body 21 of this modified example, a pair of hook-shaped portions 41 are provided as protrusions extending from the edge portion 32 at the leading end of the resin portion 3, and a pair of fitting portions 51 are provided as recesses on the edge portion 32 and outer circumference of the resin portion 3 approximately in the center of the resin portion 3.

[0052] As shown in Figures 10(b) and 10(c), even with this configuration, similar to the protective tube 1 described above, by inserting the tip of the hook-shaped portion 41 of the split pipe body 21A into the fitting portion 51 of the split pipe body 21B located at the rear end of the protective tube 1, and then rotating the split pipe body 21A closer to the split pipe body 21B, the hook-shaped portion 41 fits into the fitting portion 51, and the split pipe body 21A can be connected to the protective tube 1 at the other end.

[0053] Figure 11 shows a second modified example. As shown in Figure 11(a), in this modified example, a pair of hook-shaped portions 41 are provided approximately in the center of the resin portion 3, and a pair of fitting portions 51 are provided at the leading end of the resin portion 3. The hook-shaped portions 41 are convex from the edge portion 32 toward the rear end of the resin portion 3. The fitting portions 51 are recessed in the edge portion 32 and outer circumference of the resin portion 3 and are formed to fit with the hook-shaped portions 41 of the opposingly arranged split pipes 22.

[0054] As shown in Figures 11(b) and 11(c), even with this configuration, by fitting the tip of the fitting portion 51 of the split pipe body 22A into the hook-shaped portion 41 of the split pipe body 22B located at the rear end of the protective pipe 1, and then rotating the split pipe body 22A closer to the split pipe body 22B, the hook-shaped portion 41 engages with the fitting portion 51, and the split pipe body 22A is connected to the protective pipe 1. Then, by fitting the hook-shaped portion 41 of the connected split pipe body 22A into the fitting portion 51 of a new split pipe body 22B (not shown), the split pipe body 22B can be further connected to the protective pipe 1.

[0055] Figure 12 shows a third modified example. As shown in Figure 12(a), in this modified example, the split pipe body 23 is provided with hook-shaped portions 41a and 41b on one edge 32 and fitting portions 51a and 51b on the other edge 32. The hook-shaped portions 41a and 41b are the same as the hook-shaped portions 41 of the split pipe bodies 21 and 22 described above. The fitting portions 51a and 51b are the same as the fitting portions 51 of the split pipe bodies 22 and 21.

[0056] As shown in Figures 12(b) and 12(c), even with this configuration, by inserting the tip of the hook-shaped portion 41a of the split pipe body 23A into the fitting portion 51b of the split pipe body 23B located at the rear end of the protective pipe 1, and then rotating the split pipe body 23A closer to the split pipe body 23B, the hook-shaped portion 41a engages with the fitting portion 51b, and the split pipe body 23A is connected to the protective pipe 1. At this time, although not shown because it is hidden by the hook-shaped portion 41a and the fitting portion 51b, the hook-shaped portion 41b of the split pipe body 23B is engaged with the fitting portion 51a of the split pipe body 23A on the far side of the page. Then, by fitting the hook-shaped portion 41b and fitting portion 51b of the connected split pipe body 23A onto the fitting portion 51a and hook-shaped portion 41a of a new split pipe body 23B (not shown), the split pipe body 23B can be further connected to the protective pipe 1 at the other end.

[0057] Figure 13 shows a fourth modified example. As shown in Figure 13(a), in this modified example, the split pipe body 24 is provided with two hook-shaped portions 41a, 41b and two fitting portions 51a, 51b on each of the pair of edges 32. The hook-shaped portions 41a and fitting portions 51a are the same as the hook-shaped portion 41 and fitting portion 51 of the split pipe body 21 described above. The hook-shaped portion 41b is provided at approximately the midpoint between the hook-shaped portion 41a and the fitting portion 51a, and is convex in a direction toward the hook-shaped portion 41a from the edge 32. The fitting portions 51b are recessed in the edge 32 and outer circumference of the resin portion 3 and are formed to fit with the hook-shaped portions 41b of the opposingly arranged split pipe body 24.

[0058] As shown in Figures 13(b) and 13(c), in this configuration, with the tip of the hook-shaped portion 41a of the split pipe body 24A inserted into the fitting portion 51a of the split pipe body 24B located at the rear end of the protective pipe 1, the split pipe body 24A is rotated to bring it closer to the split pipe body 24B, so that the hook-shaped portions 41a and 41b fit into the fitting portions 51a and 51b respectively, and the split pipe body 24A is connected to the protective pipe 1. Then, by fitting the hook-shaped portions 41a and 41b of a new split pipe body 24B (not shown) into the fitting portions 51a and 51b of the split pipe body 24A that has been connected in this way, the split pipe body 24B can be further connected to the protective pipe 1.

[0059] Figure 14 shows a fifth modified example. As shown in Figure 14(a), the split pipe body 25 of this modified example is formed by linearly shaping the hook-shaped portion 41 and the fitting portion 51 based on the split pipe body 21 described above. In this configuration, as with the split pipe body 21 described above, it is possible to connect the split pipe body 25 to the protective pipe 1 by rotation. However, as shown in Figures 14(b) and (c), the hook-shaped portion 41 of the split pipe body 25A can also be linearly slid into the fitting portion 51 of the split pipe body 25B located at the rear end of the protective pipe 1, along the direction in which the hook-shaped portion 41 extends (indicated by the arrow), thereby fitting the hook-shaped portion 41 into the fitting portion 51 and connecting the split pipe body 25A to the protective pipe 1.

[0060] Figure 15 shows a sixth modified example. As shown in Figures 15(a) to (c), the split tubes 26, 27, and 28 of this modified example are based on the split tubes 22, 23, and 24 described above, with the hook-shaped portions 41, 41a, and 41b and the fitting portions 51, 51a, and 51b formed in a straight line, similar to the split tube 25. In these split tubes 26, 27, and 28, the hook-shaped portions 41, 41a, and 41b can be fitted into the fitting portions 51, 51a, and 51b by sliding motion in addition to rotational motion.

[0061] In addition, in the split pipe bodies 21 to 28 described above, the hook-shaped portion and the fitting portion may be made of resin material if they have sufficient rigidity, but it is preferable that they be made of metal. Furthermore, the split pipe bodies 21 to 28 may be configured to have a locking mechanism in the hook-shaped portion and the fitting portion, or to have a projection and a protruding ridge in the connecting portion, or the resin portion may be optionally provided with inclined portions, protrusions and grooves.

[0062] It should be noted that the protective tube according to the present invention is not limited to the above embodiment and can be modified in various ways. For example, the number of metal parts can be appropriately determined by the length of the split tube, etc., and may be one or three or more. Also, the pair of split tubes do not necessarily have to be the same shape as each other and may be different shapes. [Explanation of Symbols]

[0063] 1 Protection tube 2, 2A, 2B, 21~28 semitubular body 3 Resin part 31 Torso 32 Edge 33. Sloping section ahead 34 Rear slope 4 1st metal part (metal part) 41, 41a, 41b Unicum 43 Hook tip 46. ​​Turning part 48 recess 5 Second metal part (metal part) 51, 51a, 51b mating part 57 Receiving part 58 Convex part 6. Connection part 61 Connecting protrusion 62 Connection recess 64 Protrusion 65 Convex part 66 Recessed area C circumferential direction D Extension direction L linear body R Radial direction

Claims

1. A protective tube in which a pair of halved tube bodies are positioned with their concave sides facing each other to cover a linear body from two directions, The aforementioned split tube has an engaging portion for engaging with an opposing split tube, and a plurality of them are connected along the extension direction of the linear body, and the split tubes covering one side of the linear body and the split tubes covering the other side are arranged to be offset from each other by half a pitch, characterized in that the protective tube is such that the split tubes have engaging portions for engaging with an opposing split tube, and a plurality of them are connected along the extension direction of the linear body, and the split tubes covering one side of the linear body and the other side are arranged to be offset from each other by half a pitch.

2. The aforementioned split pipe body has a resin portion formed in a substantially semi-cylindrical shape and forming the main body of the split pipe body, and a metal portion embedded in the resin portion by insert molding. The protective tube according to claim 1, characterized in that the engaging portion is provided on the metal portion.

3. The engaging portion has a hook-shaped portion that protrudes outward from the resin portion toward the opposing half-tube body, and a fitting portion that is exposed from the resin portion and fits with the hook-shaped portion. The aforementioned hook-shaped portion has a barb portion provided near the tip of the hook, The protective tube according to claim 2, characterized in that the fitting portion has a barb receiving portion that engages with the barb portion.

4. The protective tube according to claim 3, characterized in that the engaging portion has a convex portion that protrudes toward the opposing hook-shaped portion near the fitting portion, and a concave portion that abuts with the opposing convex portion near the hook-shaped portion.

5. The protective tube according to claim 3 or 4, characterized in that the hook-shaped portion is arranged at one end of the resin portion, and the hook tip of the hook-shaped portion of one of the split tubes is inserted into the fitting portion of the other split tube, and the one split tube is rotated to bring it closer to the other split tube.

6. The resin portion has a forward inclined portion at the forward end in the extension direction, where the concave side extends diagonally, and a rearward inclined portion at the rear end in the extension direction, where the convex side is diagonally recessed. The protective tube according to claim 5, characterized in that the rearward inclined portion has a gentler slope than the forward inclined portion, and in the adjacent half-pipe bodies in the extension direction, there is a gap between the forward rearward inclined portion and the rearward forward inclined portion.

7. The resin part comprises a body made of a long semi-cylindrical body, and a pair of edges that form both edges of the body in the extension direction and serve as contact surfaces with the opposing half-tube body. The protective tube according to claim 3, characterized in that the fitting portion is exposed from the resin portion only on the edge side.

8. The resin portion has connecting portions for connecting adjacent half-tube bodies in the extension direction to each other. The connecting portion has a connecting projection that is semi-cylindrical in shape and smaller in diameter than the outer circumference of the resin portion at the rear end in the extension direction, and a connecting recess that is recessed in the inner circumference of the resin portion at the front end in the extension direction and fits into the connecting projection of the adjacent half-tube body in the extension direction. The aforementioned connecting projection has a projection provided along the circumferential direction at the end of its outer circumference, The protective tube according to claim 2, characterized in that the connecting recess has a recess on its inner circumference into which the projection fits.

9. The protective tube according to claim 8, characterized in that the connecting projection has a raised ridge on its outer circumference that is aligned with the extension direction.

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