JP6699865B2 - Corrugated pipe - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a corrugated tube which has a continuous opening in the longitudinal direction and which is capable of closing overlapping tubes by overlapping overlapping portions near the opening end.

  Conventionally, when laying an electric wire or the like, the electric wire or the like is inserted into a protective tube such as a corrugated tube. Since the corrugated pipe has a tubular shape, it is necessary to sequentially feed the electric wire from the end in order to insert the electric wire into such a tubular member. However, this task was not always easy.

  On the other hand, there is a method in which a part of the corrugated pipe is cut along the longitudinal direction and the electric wire is inserted from this cut. In this case, the workability is good because it is not necessary to send the electric wire in the longitudinal direction.

  When using a corrugated tube with such an opening, in order to prevent the electric wire inserted from the opening from being exposed and damaged, after inserting the electric wire into the corrugated tube, tape the corrugated tube. It must be wrapped to prevent the wires from being exposed to the outside. Therefore, it has been desired to reduce the cost by simplifying the work.

  As such a corrugated tube, for example, a corrugated tube in which peaks and troughs in the circumferential direction are alternately provided in the axial direction and which has a slit over the entire length in the axial direction and which can lock the slit in a closed state is provided. There is (Patent Document 1).

  In Patent Document 1, a female-side lock portion is formed by continuously forming an engaging concave-convex portion in the circumferential direction from the slit end on one side of the mountain portion that sandwiches the slit. Further, on the other side of the mountain portion that sandwiches the slit, a concave-convex portion for locking is continuously formed in the circumferential direction from the slit end to form a male-side lock portion. The slit can be locked in a closed state by inserting the male side locking portion into the inner surface side of the female side locking portion and fitting the concave portions and the convex portions in an overlapping manner.

  Further, there is a corrugated tube for wire harness in which stopper pieces are provided on the inner tube body and the outer tube body, and the large opening can be closed by mutual engagement of the stopper pieces (Patent Document 2).

  In Patent Document 2, a flexible circular tubular body that houses a wire harness is configured by a combination of an inner tubular body and an outer tubular body that are divided in the longitudinal direction of the tubular body. The inner tubular body and the outer tubular body are notched arc tubes having a large opening in the longitudinal direction of the tubular body, and they are superposed on each other and are slidable in the circumferential direction of the tubular body. Further, an operating piece is provided on the outer circumference of either the inner tube body or the outer tube body. A relative circular slide of the inner tube and the outer tube by means of the operating piece can form a single circular tube with the large opening closed. At this time, a stopper piece that makes a pair is provided on the inner tube and the outer tube. The stopper piece functions as an actuating piece, and the large opening can be closed by mutual engagement of the stopper pieces.

  Further, there is a corrugated tube that is a tubular corrugated tube that is provided with an electric wire inside to protect the corrugated tube and that has a pair of bending restricting portions that face each other across an internal space (Patent Document 3).

  In Patent Document 3, a plurality of convex ridges along the circumferential direction and a plurality of troughs of the concave ridge along the circumferential direction are alternately and continuously formed in the central axis direction. The bend restricting portion is provided on the inner peripheral side of the tops of the plurality of peaks and extends linearly across the plurality of peaks and the plurality of valleys in the axial direction. A pair of bend restricting portions of the corrugated tube are provided at positions facing each other with the central axis interposed therebetween.

  Further, there is a corrugated tube in which ribs connecting adjacent peaks and peaks of corrugated tubes alternately formed in the peaks or valleys in the pipe axis direction as outer pipes or inner pipes are formed above the valleys. (Patent Document 4).

  In Patent Document 4, the inner member and the outer member, which have openings facing each other via the hinge portion, are bent to bend the hinge portion, so that the inner member and the outer member can be superposed and the pipe can be closed and closed. .. The corrugated tube of Patent Document 4 forms a substantially elliptical cross section.

Japanese Patent Laid-Open No. 10-136531 JP, 07-245842, A JP2012-157181A International publication WO2015/099128

  However, in Patent Document 1, since the lock mechanism is formed in the mountain portion of the fitting portion near the slit to prevent the mouth from opening, the strength of the corrugated tube changes largely at the lock mechanism portion.

  Further, in Patent Document 2, the large opening portion is closed by mutual engagement of the stopper pieces, and the stopper pieces project in the pipe outer peripheral direction. Therefore, the stopper piece may be damaged when the corrugated pipe is laid.

  Moreover, although the patent document 3 and the patent document 4 have a rib-like structure, these prevent the corrugated tube from bending, and the corrugated tube cannot be maintained in a closed state.

  The present invention has been made in view of such a problem, and an object thereof is to provide a corrugated tube capable of preventing opening of the mouth.

  In order to achieve the above-mentioned object, the present invention is a corrugated pipe in which a plurality of circumferentially extending peaks and troughs are alternately formed at predetermined intervals in the axial direction of the pipe, and the corrugated pipe has an opening in the pipe circumferential direction. In a cross section perpendicular to the longitudinal direction of the corrugated pipe, the overlapped part in which the peaks and the valleys of the corrugated pipe overlap each other at both ends in the circumferential direction of the corrugated pipe, and In a state in which the corrugated pipe is connected to connect the overlapping portions, and the corrugated tube is opened without overlapping the overlapping portions, one of the overlapping portions is one in the cross section perpendicular to the longitudinal direction of the corrugated tube. The inner overlapping portion, the other overlapping portion is an outer overlapping portion, the pitch of the peak portion and the valley portion of the inner overlapping portion and the peak portion and the valley portion of the outer overlapping portion The pitches of the overlapping portions, the peak portions of the overlapping portion and the valley portions are overlapped, the peak portion of the inner overlapping portion is stored in the peak portion of the outer overlapping portion, It is possible to close the corrugated pipe, the overlapping portion is formed with a rib that connects the peaks in the pipe axial direction along the pipe axial direction, and in the valley portion of the inner overlapping portion. The formed rib is formed in a size that can be accommodated in the rib formed in the valley of the outer overlapping portion, and when the inner overlapping portion and the outer overlapping portion are overlapped with each other, The corrugated pipe is characterized in that the rib of the inner overlapping portion is housed in the rib of the outer overlapping portion so that the overlapping portion can be fixed.

In a state where the corrugated tube is opened without overlapping the overlapping section, in the cross section perpendicular to the longitudinal direction of the corrugated tube, the inner overlapping section is arranged on the outer peripheral side of the outer overlapping section, Alternatively, the outer overlapping portion may be arranged on the same curve as the inner overlapping portion at a position where the inner overlapping portion is extended.

  It is desirable that the width of the inner peripheral surface of the mountain portion of the outer overlapping portion gradually widens toward the base portion of the mountain portion.

  The width of the outer peripheral surface of the mountain portion of the inner overlapping portion is formed narrower than the width of the inner peripheral surface of the mountain portion of the outer overlapping portion, of the outer peripheral surface of the mountain portion of the inner overlapping portion. It is desirable that the height is lower than the height of the inner peripheral surface of the mountain portion of the outer overlapping portion.

  At least one of the boundary portion between the inner overlapping portion and the curved connecting portion and the boundary portion between the outer overlapping portion and the curved connecting portion may have a step portion in the circumferential direction.

  Two ribs of the outer overlapping portion may be formed in parallel at a predetermined interval in the circumferential direction, and one rib of the inner overlapping portion may be formed.

  Two of the ribs of the outer overlapping portion are formed in parallel with each other at a predetermined interval in the circumferential direction, and the rib of the inner overlapping portion has an interval corresponding to the rib of the outer overlapping portion. Two pieces may be formed.

  The ribs may be formed intermittently at a predetermined interval in the axial direction of the corrugated tube.

  The ribs may connect the mountain portions that are adjacent to each other in the axial direction of the corrugated pipe in an alternating manner.

  The rib may be formed at the same height as the height of the mountain portion.

  According to the present invention, by forming ribs on the peaks of the inner overlapping portion and the outer overlapping portion, respectively, when the inner overlapping portion and the outer overlapping portion overlap in the circumferential direction, The ribs can be fitted together. For this reason, the inner overlapping portion and the outer overlapping portion's circumferentially extending peaks and troughs are fitted to each other to prevent displacement in the pipe axial direction, and by fitting the ribs together, the corrugated pipe is fitted. It is possible to more reliably prevent the mouth from opening in the circumferential direction. For this reason, the corrugated pipe is reliably maintained in the closed state, and the electric wire inside is not exposed to the outside.

  Further, by making the width of the inner peripheral surface of the mountain portion of the outer overlapping portion gradually widen toward the base portion of the mountain portion, it is easy to overlap with the inner overlapping portion.

  Further, by forming a predetermined clearance in the width direction of the peaks and valleys of the inner overlap portion and the outer overlap portion, the deformation of the peaks and valleys of the corrugated pipe is cleared when the corrugated pipe is bent. Can be partially absorbed by. For this reason, it is difficult for the corrugated pipes to be overlapped.

  Similarly, by forming a predetermined clearance in the height direction of the peaks and troughs of the inner overlap portion and the outer overlap portion, deformation of the peaks and troughs of the corrugated pipe can be prevented during bending of the corrugated pipe. Can be partially absorbed by the clearance. For this reason, it is difficult for the corrugated pipes to be overlapped.

  Further, by providing a step at the boundary between each overlapping portion and the curved connecting portion, it is possible to prevent the overlapping portion from slipping into the curved connecting portion in the circumferential direction.

  Further, two ribs of the outer overlapping portion are formed in parallel with each other at a predetermined interval in the circumferential direction, and one rib of the inner overlapping portion is formed, so that the ribs of the inner overlapping portion are fitted to each other. The rib of the overlapping portion can be selected. Therefore, it is possible to change the overlapping position.

  Further, by forming two ribs for the outer overlapping portion and two ribs for the inner overlapping portion, it is possible to more firmly maintain the closed state of the corrugated tube.

  Further, by forming ribs intermittently at a predetermined interval in the axial direction of the corrugated pipe, the bendability of the corrugated pipe can be improved.

  In particular, by forming the ribs so that the mountain portions adjacent to each other in the axial direction of the corrugated pipe are alternately and alternately connected, the bendability of the corrugated pipe can be secured and the overlapping portion can be fixed at the same time. ..

  Further, if the rib is formed at the same height as the height of the mountain portion, the rib does not project to the outer circumference of the pipe, and damage to the rib or the like can be suppressed when the corrugated pipe is routed.

  According to the present invention, it is possible to provide a corrugated tube capable of preventing opening of the mouth.

The top view which shows the corrugated tube 1 in the open state. It is sectional drawing which shows the corrugated tube 1, and is the sectional view on the AA line of FIG. It is sectional drawing which shows the corrugated pipe 1, and is the BB sectional view taken on the line of FIG. It is sectional drawing which shows the corrugated pipe 1, and is the BB sectional view taken on the line of FIG. It is sectional drawing which shows the corrugated pipe 1, and is the BB sectional view taken on the line of FIG. It is sectional drawing which shows the corrugated tube 1, and is CC sectional view taken on the line of FIG. It is sectional drawing which shows the corrugated pipe 1, (a) is the DD sectional view taken on the line of FIG. 2, (b) is the DD sectional view taken on the line of FIG. The top view which shows the corrugated tube 1 in the closed state. It is sectional drawing which shows the corrugated tube 1, and is the KK sectional view taken on the line of FIG. It is sectional drawing which shows the corrugated tube 1, and is the NN sectional view taken on the line of FIG. It is sectional drawing which shows the corrugated pipe 1, (a) is the LL sectional view taken on the line of FIG. 9, (b) is the M section enlarged view of (a). Sectional drawing which shows the corrugated tube 1c. The top view which shows the corrugated tube 1a of the open state. The top view which shows the corrugated tube 1b of the open state. (A) is sectional drawing which shows the corrugated tube 20, (b) is sectional drawing which shows the corrugated tube 1.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing the corrugated tube 1, FIG. 2 is a sectional view taken along the line AA of FIG. 1 (a sectional view perpendicular to the longitudinal direction of the corrugated tube 1), and FIGS. 6 is a sectional view taken along line BB of FIG. 1 (a sectional view perpendicular to the longitudinal direction of the corrugated tube 1). 1 to 6 show a state in which the corrugated tube 1 is open (the tube is not closed). The details of the closed state of the tube will be described later.

  In the corrugated tube 1, a plurality of peaks 3 and valleys 5 extending in the circumferential direction are alternately formed at predetermined intervals and repeatedly formed in the axial direction of the tube. In the following description, the convex shape on the outer surface side of the corrugated tube 1 will be referred to as the crest portion 3, and the concave shape on the outer surface side of the corrugated tube 1 will be referred to as the trough portion 5. Therefore, the portion having a convex shape on the inner surface side of the corrugated tube 1 is the inner surface side of the valley portion 5, and the portion having a concave shape on the inner surface side of the corrugated pipe 1 is the inner surface side of the mountain portion 3.

  The corrugated tube 1 has an opening 11 in the tube circumferential cross section. That is, the opening 11 is formed continuously in the tube axis direction of the corrugated tube 1. Further, in a cross section perpendicular to the longitudinal direction of the corrugated tube, at both ends in the circumferential direction of the corrugated tube 1, overlapping portions 7 in which the peak portions 3 of the corrugated tube 1 and the valley portions 5 overlap each other are provided. In the state where the corrugated tube 1 is opened without overlapping the overlapping section 7, one end side of the overlapping section 7 is the inner overlapping section 7a in the cross section perpendicular to the longitudinal direction of the corrugated tube 1. The other end side is the outer overlapping portion 7b.

  A curved connecting portion 9 is formed between the inner overlapping portion 7a and the outer overlapping portion 7b of the corrugated tube 1. That is, the curved connecting portion 9 is a portion that connects the inner overlapping portion 7a and the outer overlapping portion 7b.

  7A is a sectional view taken along the line DD of FIG. 2, and FIG. 7B is a sectional view taken along the line EE of FIG. That is, FIG. 7A is a sectional view of the outer overlapping portion 7b (a sectional view in the longitudinal direction of the corrugated tube 1), and FIG. 7B is a sectional view of the inner overlapping portion 7a (the corrugated tube 1). 2 is a cross-sectional view in the longitudinal direction of FIG.

  As described above, the peak portions 3 and the valley portions 5 are alternately and repeatedly formed in each overlapping portion. The inner surface dimension of the crest portion 3 of the outer overlapping portion 7b is larger than the outer surface dimension of the crest portion 3 of the inner overlapping portion 7a. The inner surface dimension of the valley portion 5 of the outer overlapping portion 7b is smaller than the outer surface dimension of the valley portion 5 of the inner overlapping portion 7a. Further, the pitch of the crests 3 and the troughs 5 of the inner overlapping portion 7a and the pitch of the crests 3 and the troughs 5 of the outer overlapping portion 7b match.

  Therefore, in the corrugated pipe 1, it is possible to reduce the diameter of the curved connecting portion 9 so that the peak portions 3 and the trough portions 5 of the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped with each other. By doing so, the corrugated tube 1 can be closed.

  Here, the wall thickness at the top of the mountain portion 3 of the inner overlapping portion 7a (t2 in FIG. 2) and the wall thickness at the top of the mountain portion 3 of the outer overlapping portion 7b (t3 in FIG. 2) are the curved connecting portions 9 It is desirable that the thickness is formed thinner than the thickness of the top portion of the mountain portion 3 (t1 in FIG. 2). In the following description, the thickness of each portion is the thickness at the top of the mountain portion 3 unless otherwise specified.

  By doing so, when the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped with each other, it is possible to prevent the thickness of the overlapping portion from becoming too thick. Therefore, the bendability of the corrugated tube 1 during bending can be improved by reducing the total thickness of the overlapping portion of the inner overlapping portion 7a and the outer overlapping portion 7b.

  The inner overlapping portion 7a is arranged on the outer peripheral side of the outer overlapping portion 7b in a state where the ends of the inner overlapping portion 7a and the outer overlapping portion 7b are abutted with each other without closing the corrugated tube 1. That is, as shown in FIG. 3, assuming that the center position of the curved connecting portion 9 is O1, the ends of the inner overlapping portion 7a and the outer overlapping portion 7b are abutted with each other, and the inner overlapping portion 7a is moved from the center position O1. Is greater than the distance U from the central position O1 to the inner surface of the outer overlapping portion 7b. By doing so, as will be described later, when the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped with each other, the elastic repulsive force with respect to the outer overlapping portion 7b is exerted on the outer peripheral surface of the inner overlapping portion 7a. Can be affected.

  More specifically, in a state where both ends of the corrugated tube 1 in the circumferential direction are abutted, the distance T from the outer peripheral surface of the tip of the inner overlapping portion 7a to the central position O1 of the curved connecting portion 9 is the outer overlapping portion. It is desirable that the distance U is 2 to 10% larger than the distance U from the inner peripheral surface of the tip of 7b to the central position O1 of the curved connecting portion 9. That is, it is desirable that T=U×1.02 to 1.1.

  If the ratio of the distance between the two is less than 2%, when the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped with each other, the outer peripheral surface of the inner overlapping portion 7a is sufficient with respect to the outer overlapping portion 7b. Elastic repulsion cannot be applied. On the other hand, if the ratio of the distance between the two is greater than 10%, it becomes difficult to overlap the inner overlapping portion 7a with the outer overlapping portion 7b. Further, if the ratio of the distance between the two is too large, when the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped with each other, the elastic repulsive force may be too large and the overlapping portion may be displaced or opened. .. Therefore, it is desirable that the ratio of the distance between the two is in the range of 2 to 10%.

  Further, in a state where both ends of the corrugated tube 1 in the circumferential direction are butted, the radius of curvature of the inner peripheral surface of the inner overlapping portion 7a (R1 in FIG. 4) and the radius of curvature of the outer overlapping portion 7b (R2 in FIG. 4). 2), the radius of curvature R1 of the inner overlapping portion 7a is larger than the radius of curvature R2 of the outer overlapping portion 7b.

  The center O2 of the radius of curvature R2 of the outer overlapping portion 7b is arranged at a position offset from the center position O1 of the curved connecting portion 9. More specifically, as shown in FIG. 4, the center O2 of the radius of curvature R2 of the outer overlapping portion 7b is arranged at a position offset from the center position O1 of the curved connecting portion 9 toward the outer overlapping portion 7b. It The center O3 of the radius of curvature R1 of the inner overlapping portion 7a is arranged at a position offset from the center O1 of the curved connecting portion 9 toward the curved connecting portion 9 side opposite to the inner overlapping portion 7a side.

  By doing so, when the inner overlapping portion 7a is overlapped with the outer overlapping portion 7b, the inner overlapping portion 7a arranged inside the outer overlapping portion 7b having a small radius of curvature is located on the outer periphery thereof. Abut to expand. Therefore, the elastic repulsive force can be generated so that the curvature radii of both are equal. Further, the inner overlapping portion 7a and the outer overlapping portion 7b can be smoothly connected to the curved connecting portion 9. For this reason, unnecessary distortion or the like is formed on the outer peripheral surface of the boundary between the outer overlapping portion 7b and the curved connecting portion 9 and the inner peripheral surface of the boundary between the inner overlapping portion 7a and the curved connecting portion 9. There is no.

  Here, a step portion 13a is provided in the circumferential direction on the outer peripheral surface of the boundary portion between the inner overlapping portion 7a and the curved connecting portion 9. Due to the step portion 13a, the outer peripheral surface of the mountain portion 3 of the inner overlapping portion 7a is located inside the outer peripheral surface of the mountain portion 3 of the curved connecting portion 9. That is, in the vicinity of the boundary between the inner overlapping portion 7a and the curved connecting portion 9, the distance from the center O1 of the curved connecting portion 9 to the outer peripheral surface of the mountain portion 3 of the inner overlapping portion 7a (F in FIG. 5) The distance (G in FIG. 5) from the center O1 of the curved connection portion 9 to the outer peripheral surface of the mountain portion 3 of the curved connection portion 9 is larger.

  Similarly, a step portion 13b is provided in the circumferential direction on the inner peripheral surface of the boundary portion between the outer overlapping portion 7b and the curved connecting portion 9. Due to the step portion 13b, the inner peripheral surface of the valley portion 5 of the outer overlapping portion 7b is located outside the inner peripheral surface of the valley portion 5 of the curved connecting portion 9. That is, in the vicinity of the boundary between the outer overlapping portion 7b and the curved connecting portion 9, the distance (I in FIG. 5) from the center O1 of the curved connecting portion 9 to the inner peripheral surface of the valley portion 5 of the outer overlapping portion 7b. Also, the distance (H in FIG. 5) from the center O1 of the curved connecting portion 9 to the inner peripheral surface of the valley portion 5 of the curved connecting portion 9 is smaller.

  In this way, by providing the step portions 13a and 13b on the inner overlapping portion 7a and the curved connecting portion 9, when the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped, the inner overlapping portion 7a and the curved connecting portion are formed. It is possible to prevent the 9 from slipping into the curved connecting portion 9 in the circumferential direction. The details of the overlapping state of the inner overlapping portion 7a and the curved connecting portion 9 will be described later.

  Further, the angle (θ1 in FIG. 5) at which the inner overlapping portion 7a is formed in the circumferential direction with respect to the center O1 of the curved connecting portion 9 is preferably in the range of 35° to 65°. Similarly, the angle (θ2 in FIG. 5) at which the outer overlapping portion 7b is formed with respect to the center O1 of the curved connecting portion 9 is preferably in the range of 35° to 65°. More preferably, it is 35° to 60°.

  In this way, by forming the inner overlapping portion 7a and the outer overlapping portion 7b in the circumferential length at an angle of 35° or more, the inner overlapping portion 7a and the outer overlapping portion 7b can be formed in the circumferential direction. A sufficient overlap margin can be secured. Therefore, opening of the corrugated tube 1 during bending can be prevented.

  Further, when the corrugated pipe 1 is changed from the open pipe state to the closed pipe state, the diameter of the curved connecting portion 9 is reduced, but when the overlapping length of the inner overlapping portion 7a and the outer overlapping portion 7b is long, the overlapping is performed. The amount of diameter reduction at the time of matching increases. On the other hand, by forming the inner overlapping portion 7a and the outer overlapping portion 7b in the circumferential length at an angle of 65° or less, it is easy to overlap the inner overlapping portion 7a and the outer overlapping portion 7b. Becomes If the circumferential lengths of the inner superposed portion 7a and the outer superposed portion 7b exceed 65°, the diameter reduction amount at the time of superposition becomes too large, and the diameter reduction becomes difficult, and the shape after the diameter reduction is also unsatisfactory. Easy to be stable.

  Further, the inner overlapping portion 7a is formed with a rib 17a that connects the mountain portions 3 to each other in the tube axis direction along the tube axis direction. Similarly, the outer overlapping portion 7b is provided with a rib 17b that connects the mountain portions 3 to each other in the tube axis direction along the tube axis direction.

  As shown in FIG. 6, the rib 17 a is formed at a height from the base of the valley 5 to the top of the mountain 3. That is, the rib 17a is formed at the same height as the height of the crest portion 3, and the outer surface of the rib 17a does not project outward than the outer surface of the crest portion 3 of the inner overlapping portion 7a. Further, in the circumferential cross section, the width (circumferential length) of the inner peripheral surface of the rib 17a gradually widens toward the base portion (the valley portion 5 side) of the rib 17a.

  Similarly, the rib 17 b is formed at a height from the base of the valley 5 to the top of the mountain 3. That is, the rib 17b is formed at the same height as the height of the ridge portion 3, and the outer surface of the rib 17b does not protrude outwardly than the outer surface of the ridge portion 3 of the outer overlapping portion 7b. Further, in the circumferential cross section, the width (circumferential length) of the inner circumferential surface of the rib 17b gradually widens toward the base portion (the valley portion 5 side) of the rib 17b.

  The width of the outer peripheral surface of the rib 17a is narrower than the width of the inner peripheral surface of the rib 17b. That is, the rib 17a formed in the valley portion 5 of the inner overlapping portion 7a is formed in a size that can be accommodated in the rib 17b formed in the valley portion 5 of the outer overlapping portion 7b.

  Next, a state in which the corrugated tube 1 is closed will be described. 8 is a plan view showing the corrugated tube 1 in a closed state, FIG. 9 is a sectional view taken along line KK of FIG. 8 (a section perpendicular to the longitudinal direction of the corrugated tube 1), and FIG. 2 is a sectional view taken along line RR (a section perpendicular to the longitudinal direction of the corrugated tube 1).

  As shown in the drawing, by reducing the diameter of the curved connecting portion 9, the inner overlapping portion 7a can be overlapped with each other so as to come inside the outer overlapping portion 7b (arrow J direction in the figure). That is, in the state where the peaks 3 and the troughs 5 of the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped with each other, the peaks 3 of the inner overlapping portion 7a become the peaks 3 of the outer overlapping portion 7b. It is stored. By doing so, the corrugated tube 1 can be closed.

  For example, when the corrugated tube 1 is opened, an electric wire or the like is accommodated inside the corrugated tube 1 through the opening 11. At this time, since the electric wire or the like can be inserted through the opening 11, it is not necessary to feed the electric wire or the like from the end portion of the corrugated tube 1 over the entire length. After that, by closing the corrugated pipe 1 as described above, the electric wires and the like can be reliably protected without being exposed to the outside.

  When the corrugated tube 1 is closed, the inner overlapping portion 7a is contacted with a part or all of the inner peripheral surfaces of the peaks 3 and valleys 5 of the outer overlapping portion 7b. It is superposed on the inside of 7b. As described above, when the diameter of the curved connecting portion 9 is reduced and the corrugated tube 1 is closed, the ridges 3 and the outer peripheral surfaces of the valleys 5 of the inner overlapping portion 7a and the outer overlapping portion 7b have the same shape. An elastic repulsive force is exerted on the valley 5.

  11A is a cross-sectional view taken along line LL in FIG. 9 (cross-sectional view in the circumferential direction of the corrugated tube 1), and FIG. 11B is an enlarged view of the M portion of FIG. 11A. As described above, when the corrugated tube 1 is closed, the peak portions 3 and the trough portions 5 of the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped with each other.

  Here, the width of the inner peripheral surface of each crest portion 3 of the inner overlapping portion 7a and the outer overlapping portion 7b gradually widens toward the base portion (the valley portion 5 side) of the mountain portion 3. .. Further, the width of the outer peripheral surface of the mountain portion 3 of the inner overlapping portion 7a that fits with the mountain portion 3 of the outer overlapping portion 7b is narrower than the width of the inner peripheral surface of the mountain portion 3 of the outer overlapping portion 7b. It is formed.

  More specifically, when the outer overlapping portion 7b and the inner overlapping portion 7a are overlapped with each other, the width of the inner peripheral surface of the mountain portion 3 of the outer overlapping portion 7b (N in FIG. 11B) is , The width of the outer peripheral surface of the mountain portion 3 of the inner overlapping portion 7a (O in FIG. 11B). In addition, with respect to the width direction at an arbitrary position, between the inner peripheral surface of the mountain portion 3 of the outer overlapping portion 7b and the outer peripheral surface of the mountain portion 3 of the inner overlapping portion 7a, one side is 10 to 20% (width N The clearance in the range of () is formed. That is, O=N×0.6 to 0.8 is set.

  Further, the height of the outer peripheral surface of the mountain portion 3 of the inner overlapping portion 7a (Q in FIG. 11(b)) is the height of the inner peripheral surface of the mountain portion 3 of the outer overlapping portion 7b (FIG. 11(b)). Lower than P). Further, when the outer overlapping portion 7b and the inner overlapping portion 7a are overlapped with each other, the height of the inner peripheral surface of the mountain portion 3 of the outer overlapping portion 7b and the outer peripheral surface of the mountain portion 3 of the inner overlapping portion 7a is increased. A clearance in the range of 10 to 20% is formed between the height directions of the height P of the inner peripheral surface of the mountain portion 3 of the outer overlapping portion 7b. That is, Q=P×0.8 to 0.9 is set.

  Here, when the corrugated pipe 1 is bent, the peaks 3 and the valleys 5 of the corrugated pipe 1 are deformed, and as a result, the corrugated pipe 1 is locally deformed in the pipe axial direction. On the other hand, by providing clearances in the fitting portions of the peaks 3 and the troughs 5 of the outer overlapping portion 7b and the inner overlapping portion 7a, the expansion and contraction can be partially absorbed by the clearance. For this reason, it is difficult for the overlapping portions of the outer overlapping portion 7b and the inner overlapping portion 7a to come off. Further, if the clearance is sufficient, it is possible to surely fit the peak portions 3 to each other and the valley portions 5 to each other.

  In order to maintain the closed state of the corrugated tube 1 more reliably, the corrugated tube 1 may be subjected to a heat treatment. For example, when the corrugated tube 1 is made of thermoplastic resin, the corrugated tube 1 can be stably maintained in a desired shape by heating the corrugated tube 1.

  In this case, after the corrugated pipe 1 is heated to a predetermined temperature, the corrugated pipe 1 may be closed, or the corrugated pipe 1 may be closed while heating the corrugated pipe 1 to a predetermined temperature. After holding, it may be heated to a predetermined temperature. Further, the corrugated tube 1 may be processed into a closed tube shape by holding it in a die in a batch system, or by any method such as rolling in a heating oven. As the thermoplastic resin, PP (polypropylene) and PA (polyamide) are desirable from the viewpoint of moldability and cost. Also, other thermoplastic resins can be used as appropriate.

  As shown in FIG. 10, when the outer overlapping portion 7b and the inner overlapping portion 7a are overlapped with each other, the rib 17a of the inner overlapping portion 7a is housed in the rib 17b of the outer overlapping portion 7b. This makes it possible to fix the inner overlapping portion 7a and the outer overlapping portion 7b.

  The ribs 17a, 17b are preferably formed intermittently at a predetermined interval in the axial direction of the corrugated tube 1. For example, as shown in FIG. 8, it is desirable that ribs 17a and 17b be formed by skipping one valley portion 5 and that the mountain portions 3 adjacent to each other in the axial direction of the corrugated tube 1 be alternately connected.

  When the ribs 17a and 17b are continuously formed in the tube axis direction, the rigidity of the corrugated tube 1 is increased by the ribs 17a and 17b. Therefore, the bending workability of the corrugated tube 1 deteriorates. On the other hand, by forming the ribs 17a and 17b intermittently in the pipe axis direction, the corrugated tube 1 can be easily bent at a portion where the ribs 17a and 17b are not formed.

  As described above, according to the present embodiment, since the corrugated tube 1 does not have the hinge portion, the strength of the cross section of the tube in the circumferential direction can be made substantially constant. Therefore, the bending deformation of the corrugated pipe 1 and the deformation of the pipe cross section in the compression load test in which the electric wire is inserted inside the corrugated pipe can be suppressed.

  Further, when the corrugated tube 1 is opened, the inner overlapping portion 7a is located outside the outer overlapping portion 7b. Therefore, when the corrugated tube 1 is closed, the inner overlapping portion 7a can generate an elastic repulsive force to contact the outer overlapping portion 7b. Therefore, the corrugated tube 1 can be reliably closed and the opening of the corrugated tube 1 can be suppressed.

  When the corrugated tube 1 is closed, in order for the inner overlapping portion 7a to generate elastic repulsive force and make contact with the outer overlapping portion 7b, the inner overlapping portion is not necessarily opened. 7a does not need to be located outside the outer overlapping portion 7b. For example, like the corrugated tube 1c shown in FIG. 12, the outer overlapping portion 7b may be arranged at a position where the inner overlapping portion 7a is extended on the same curve as the inner overlapping portion 7a.

  In this case, the distance W from the center position O1 to the inner surface of the inner overlapping portion 7a at the abutting portion where the ends of the inner overlapping portion 7a and the outer overlapping portion 7b are abutted is It is the same as the distance V to the inner surface of the portion 7b. Even in this case, when the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped with each other, an elastic repulsive force can be exerted on the outer overlapping portion 7b by the outer peripheral surface of the inner overlapping portion 7a.

  Further, a step portion 13a is provided at a boundary portion between the inner overlapping portion 7a and the curved connecting portion 9, and a step portion 13b is provided at a boundary portion between the outer overlapping portion 7b and the curved connecting portion 9. Therefore, when the inner overlapping portion 7a and the outer overlapping portion 7b are overlapped with each other, the inner overlapping portion 7a and the outer overlapping portion 7b are prevented from entering the curved connecting portion 9 side beyond the overlapping portion. can do.

  In addition, the corrugated tube 1 is provided with clearances in the width direction and the height direction at the fitting portions of the mountain portion 3 and the valley portion 5 of the outer overlapping portion 7b and the inner overlapping portion 7a, respectively. Part of the local expansion and contraction when bending can be absorbed. Therefore, the overlapping portions of the outer overlapping portion 7b and the inner overlapping portion 7a are unlikely to come off, and the peak portions 3 and the valley portions 5 can be reliably fitted to each other.

  Further, the inner overlapping portion 7a and the outer overlapping portion 7b are provided with ribs 17a and 17b that can be fitted to each other, so that the inner overlapping portion 7a and the outer overlapping portion 7b can be more reliably fixed. it can. Therefore, when the corrugated tube 1 is closed, opening of the mouth can be reliably prevented.

  Moreover, since the ribs 17a and 17b are intermittently formed at a predetermined interval in the axial direction of the corrugated tube 1, the flexibility of the corrugated tube 1 can be ensured.

  Further, since the ribs 17a and 17b are formed at the same height as the mountain portion 3, the ribs 17a and 17b do not project to the outer periphery of the corrugated tube 1. Therefore, it is possible to prevent the ribs 17a and 17b from being caught or damaged when the corrugated tube 1 is laid.

(Second embodiment)
Next, a second embodiment will be described. FIG. 13 is a plan view of the corrugated tube 1a in the opened state. In the following description, configurations having the same functions as those of the first embodiment will be designated by the same reference numerals as those in FIGS. 1 to 11, and redundant description will be omitted.

  The corrugated tube 1a has almost the same configuration as the corrugated tube 1 and 1c, but ribs 17a and 17b are formed in parallel with each other at predetermined intervals in the circumferential direction, and two ribs are formed in the corrugated tube 1a in the axial direction. It is different in that it is done. The circumferential pitch of the two ribs 17a and the circumferential pitch of the two ribs 17b match. Therefore, when the outer overlapping portion 7b and the inner overlapping portion 7a are overlapped with each other, the two ribs 17a of the inner overlapping portion 7a are housed in the two ribs 17b of the outer overlapping portion 7b, respectively.

  According to the second embodiment, the same effect as that of the first embodiment can be obtained. In addition, by forming a plurality of ribs 17a and 17b with the same number and the same circumferential pitch, it is possible to more reliably fix the inner overlapping portion 7a and the outer overlapping portion 7b.

(Third Embodiment)

  Next, a third embodiment will be described. FIG. 14 is a plan view of the corrugated tube 1b in the opened state. The corrugated tube 1b has almost the same structure as the corrugated tube 1 except that the number of ribs 17a and 17b is not the same. In the corrugated tube 1b, one rib 17a is formed in the tube axis direction, and two ribs 17b are formed in the tube axis direction in parallel with each other at a predetermined interval in the circumferential direction.

  In this case, when the outer superposed portion 7b and the inner superposed portion 7a are superposed, one rib 17a of the inner superposed portion 7a is replaced by one of the two ribs 17b of the outer superposed portion 7b. To store. That is, it is possible to select whether to fit one rib 17a to any one of the plurality of ribs 17b.

  According to the third embodiment, the same effect as that of the first embodiment can be obtained. Further, the diameter of the corrugated tube 1b when the tube is closed can be changed by selecting whether to fit one rib 17a to any one of the plurality of ribs 17b.

(Method of manufacturing corrugated pipe)
Next, a method for manufacturing the corrugated tube 1 will be described. In the present embodiment, the corrugated pipe 1 will be described as an example, but the other corrugated pipes 1a to 1c can also be manufactured by the same procedure.

  FIG. 15A is a diagram showing the corrugated tube 20. The corrugated tube 20 is manufactured by, for example, extrusion processing. For example, a resin is extruded in a tubular shape from an extruder to form a tubular material. Further, while the transfer speed of the mold set on the endless track is synchronized with the extrusion speed of the cylindrical material, the mold is repeatedly transferred and supplied.

  The tubular material is formed by being sandwiched by a pair of molds. The die is a half-cylindrical half-cylindrical member having irregularities or the like formed on the inner surface according to the outer shape of the corrugated tube 20. The pair of molds face each other and are fitted together to form a tubular member, and a mountain portion, a valley portion, and the like corresponding to the outer shape of the corrugated tube 20 are formed on the inner surface.

  The corrugated tube 20 is an overall tubular member that does not have an opening along the longitudinal direction. In the corrugated tube 20, a plurality of peaks 3 and valleys 5 extending in the circumferential direction are alternately formed at predetermined intervals and repeatedly formed in the tube axis direction.

  The corrugated tube 20 is superposed such that the corrugated tube 20 has a mountain portion 3 and a valley portion 5 overlapped with each other in a part of the corrugated tube 20 in the circumferential direction in a cross section perpendicular to the longitudinal direction of the corrugated tube. It has a part 7. One end side of the overlapping portion 7 is an inner overlapping portion 7a, and the other end side is an outer overlapping portion 7b.

  A connecting portion 21 is formed between the inner overlapping portion 7a and the outer overlapping portion 7b of the corrugated tube 1 that face each other, and the inner overlapping portion 7a and the outer overlapping portion 7b are connected to each other. Further, a curved connecting portion 9 is formed between the other of the inner overlapping portion 7a and the outer overlapping portion 7b of the corrugated tube 1. That is, the curved connecting portion 9 is a portion that connects the inner overlapping portion 7a and the outer overlapping portion 7b.

  In the corrugated tube 20, the inner overlapping portion 7a is arranged on the outer peripheral side of the outer overlapping portion 7b. That is, in the vicinity of the connecting portion 21, the distance from the central position of the curved connecting portion 9 to the outer surface of the inner overlapping portion 7a is longer than the distance from the central position of the curved connecting portion 9 to the inner surface of the outer overlapping portion 7b.

  As described above, even if the distance from the central position of the curved connecting portion 9 to the inner surface of the inner overlapping portion 7a and the distance from the central position of the curved connecting portion 9 to the inner surface of the outer overlapping portion 7b are the same. Good. That is, the outer overlapping portion 7a may be arranged at a position where the inner overlapping portion 7b extends on the same curve as the inner overlapping portion 7b.

  Further, comparing the radius of curvature of the inner circumferential surface of the inner overlapping portion 7a with the radius of curvature of the outer overlapping portion 7b, the radius of curvature of the inner overlapping portion 7a is larger than the radius of curvature of the outer overlapping portion 7b. Further, the center of the radius of curvature of the outer overlapping portion 7b is arranged at a position offset from the center position of the curved connecting portion 9 toward the outer overlapping portion 7b.

  Further, here, the center of the radius of curvature of the outer overlapping portion 7b is shown at a position offset from the center of the curved connecting portion 9 toward the outer overlapping portion 7b, but the inner overlapping portion 7a has the same structure. It is also possible to dispose the center of the radius of curvature at a position offset from the center position of the curved connecting portion 9 to the curved connecting portion 9 side in the direction opposite to the inner overlapping portion 7a side. That is, the center of the radius of curvature of at least one of the inner overlapping portion 7a and the outer overlapping portion 7b may be offset from the center of the curved connecting portion 9.

  The distance from the outer peripheral surface of the tip of the inner overlapping portion 7a to the center position of the curved connecting portion 9 is 2 to more than the distance from the inner peripheral surface of the tip of the outer overlapping portion 7b to the center position of the curved connecting portion 9. 10% larger is desirable.

  A step 13a is provided in the circumferential direction at the boundary between the inner overlapping portion 7a and the curved connecting portion 9. Due to the step portion 13a, the outer peripheral surface of the mountain portion 3 of the inner overlapping portion 7a is located inside the outer peripheral surface of the mountain portion 3 of the curved connecting portion 9. Similarly, at the boundary between the outer overlapping portion 7b and the curved connecting portion 9, a step portion 13b is provided in the circumferential direction. Due to the step portion 13b, the inner peripheral surface of the valley portion 5 of the outer overlapping portion 7b is located outside the inner peripheral surface of the valley portion 5 of the curved connecting portion 9.

  The corrugated tube 1 having the opening 11 can be manufactured by cutting the connecting portion 21 of the corrugated tube 20 with the blade 23 (FIG. 15B). That is, the corrugated tube 1 can be manufactured using the corrugated tube 20. As described above, in the corrugated pipe 1 manufactured in this way, the curved connecting portion 9 is reduced in diameter so that the peaks 3 and the troughs 5 of the inner overlapping portion 7a and the outer overlapping portion 7b respectively. Can be overlaid. Therefore, it is possible to close the corrugated tube 1.

  When the diameter of the curved connecting portion 9 is reduced and the corrugated tube 1 is closed, the inner overlapping portion is contacted with a part or all of the inner peripheral surfaces of the peak portion 3 and the valley portion 5 of the outer overlapping portion 7b. The mating portion 7a is superposed on the inner side of the outer superposing portion 7b. At this time, the outer peripheral surfaces of the crests 3 and the troughs 5 of the inner overlapping portion 7a exert an elastic repulsive force on the crests 3 and the troughs 5 of the outer overlapping portion 7b.

  In addition, as described above, in order to maintain the closed tube state, heat treatment may be performed during or after the tube is closed. By doing so, the corrugated tube 1 can be stably maintained in the closed shape.

  As described above, the corrugated tube 1 can be easily manufactured by using the corrugated tube 20.

  Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not affected by the above-described embodiments. It is obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims, and naturally, these are also within the technical scope of the present invention. It is understood that it belongs.

1, 1a, 1b, 1c ......... corrugated pipe 3 ... ... mountain part 5 ... ... valley part 7 ... ... overlapping part 7a ... ... inside overlapping part 7b ... ... outside overlapping part 9 ... …Curved connection 11 ………Opening 13a, 13b ……… Steps 17a, 17b ……… Rib 20 ……… Corrugated tube 21 ……… Connecting part 23 ……… Cutlery

Claims (10)

A corrugated pipe in which a plurality of peaks and troughs extending in the circumferential direction are alternately formed at predetermined intervals and repeatedly formed in the pipe axis direction,
In the cross section perpendicular to the longitudinal direction of the corrugated pipe, which has an opening in the cross section in the circumferential direction of the pipe, the crests and the troughs of the corrugated pipe overlap each other at both ends in the circumferential direction of the corrugated pipe. An overlapping portion and a curved connecting portion connecting the overlapping portions at both ends,
In a state where the corrugated tube is opened without overlapping the overlapping section, one of the overlapping sections is an inner overlapping section and the other overlapping section is in a cross section perpendicular to the longitudinal direction of the corrugated tube. It is the outer overlapping part,
The pitch of the peaks and valleys of the inner overlapping portion and the pitch of the peaks and valleys of the outer overlapping portion are the same, and the peaks of the overlapping portions and the valleys are In a state of being overlapped, the peak portion of the inner overlapping portion is stored in the peak portion of the outer overlapping portion, and the corrugated tube can be closed.
A rib connecting the peaks to each other in the tube axis direction along the tube axis direction is formed in the overlapping section, and the rib formed in the valley section of the inner overlapping section is the outer overlapping section. Is formed in a size that can be stored in the rib formed in the valley portion of
When the inner overlapping portion and the outer overlapping portion are overlapped with each other, the rib of the inner overlapping portion may be housed in the rib of the outer overlapping portion to fix the overlapping portion. Corrugated tube characterized by being possible. In a state where the corrugated tube is opened without overlapping the overlapping section, in the cross section perpendicular to the longitudinal direction of the corrugated tube, the inner overlapping section is arranged on the outer peripheral side of the outer overlapping section, Alternatively, the corrugated tube according to claim 1, wherein the outer overlapping portion is arranged on the same curve as the inner overlapping portion, at a position where the inner overlapping portion is extended.   The corrugated pipe according to claim 1 or 2, wherein a width of an inner peripheral surface of the mountain portion of the outer overlapping portion gradually widens toward a base portion of the mountain portion.   The width of the outer peripheral surface of the mountain portion of the inner overlapping portion is formed narrower than the width of the inner peripheral surface of the mountain portion of the outer overlapping portion, of the outer peripheral surface of the mountain portion of the inner overlapping portion. The corrugated tube according to any one of claims 1 to 3, wherein the height is lower than the height of the inner peripheral surface of the mountain portion of the outer overlapping portion.   At least one of the boundary between the inner overlapping portion and the curved connecting portion and the boundary between the outer overlapping portion and the curved connecting portion has a step portion in the circumferential direction. The corrugated pipe according to any one of claims 1 to 4.   2. The rib of the outer overlapping portion is formed in parallel with two at a predetermined interval in the circumferential direction, and one rib of the inner overlapping portion is formed. The corrugated pipe according to claim 5.   Two of the ribs of the outer overlapping portion are formed in parallel at a predetermined interval in the circumferential direction, and the ribs of the inner overlapping portion have an interval corresponding to the ribs of the outer overlapping portion. The corrugated tube according to any one of claims 1 to 5, wherein two corrugated tubes are formed.   The corrugated tube according to any one of claims 1 to 7, wherein the ribs are intermittently formed at predetermined intervals in the axial direction of the corrugated tube.   9. The corrugated pipe according to claim 8, wherein the rib connects the mountain portions that are adjacent to each other in the axial direction of the corrugated pipe in an alternating manner.   The corrugated tube according to any one of claims 1 to 9, wherein the rib is formed to have the same height as the height of the mountain portion.

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