JP3156560B2 - Corrugated tube slit forming method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a slit in a pipe wall of a corrugated tube for protecting cables and the like in a bundled state.

[0002]

2. Description of the Related Art In general, a corrugated tube used for bundling and protecting a cable is made of a flexible resin material or the like, and is formed in a bellows shape in order to obtain good flexibility. A slit is formed in the wall of the corrugated tube for expanding the corrugated tube.

Conventionally, the slit is formed in a direction parallel to the axial direction of the corrugated tube. However, the slit having such a shape cannot easily expand the corrugated tube, and imposes a heavy burden on an operator. There are drawbacks.

Therefore, in recent years, a spiral slit 40 as shown in FIG.
Is provided on the tube wall (see, for example, JP-A-7-135715). According to such a corrugated tube 20, the expanding operation is easier than that of a corrugated tube having a linear slit as in the related art, and the burden on the operator can be greatly reduced.

[0005]

In the above corrugated tube, it is not easy to spirally form a slit in the wall of the tube, and it is desired to develop a method and an apparatus capable of automatically and accurately performing such an operation. It is rare.

Although the above publication describes a corrugated tube having a spiral slit, it does not disclose any slit forming means.

[0007]

As a means for solving the above problems, the present invention is a method for forming a spiral slit in a tube wall of a corrugated tube, wherein a cutter for forming the slit is rotated around a predetermined axis. And the cutter is moved along the revolving center axis of the cutter while cutting the cutter into the corrugated tube in a direction inclined with respect to the axial direction.

In this method, the cutter for forming the slit is cut into the corrugated tube in a direction inclined with respect to the axial direction. In this state, when the corrugated tube is moved in the axial direction, the cutter is cut into the cutter. The cutting resistance acts in the circumferential direction of the corrugated tube, and the cutter receiving the cutting resistance automatically revolves around the central axis of the corrugated tube. A spiral slit is automatically formed on the tube wall of the corrugated tube by simultaneously performing the revolution of the cutter and the movement of the corrugated tube.

The present invention is also an apparatus for forming a spiral slit in a tube wall of a corrugated tube, wherein the corrugated tube has a tube insertion passage which can be inserted in the axial direction thereof, and the tube insertion passage is provided. A cutter support member that supports a slit forming cutter at a position where it can be cut in a direction inclined with respect to the axial direction of the corrugated tube inserted therein, and the cutter support member is inserted into the tube insertion passage. A rotation support member rotatably supporting the corrugated tube about a central axis of the corrugated tube.

In this device, if the corrugated tube is inserted into the tube insertion passage of the cutter supporting member and the cutter is cut into the tube wall of the corrugated tube, and the corrugated tube is moved in the axial direction in this state,
Along with this movement, cutting resistance in the circumferential direction of the corrugated tube acts on the cutter, and the cutter and the cutter supporting member rotate integrally about the central axis of the corrugated tube.
By simultaneously performing the rotation of the cutter and the cutter supporting member and the movement of the corrugated tube, a spiral slit is automatically formed in the tube wall of the corrugated tube.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described with reference to FIGS.

FIG. 3 shows the overall configuration of a corrugated tube manufacturing apparatus provided with the apparatus of the present invention. This device includes an extrusion molding device 10, a bellows molding device 12, a slit forming device 14, a take-up device 16, and a winding device 18 of the present invention. The extrusion molding apparatus 10 extrudes a cylindrical tube using a molten resin. The bellows forming apparatus 12 is for making the tube bellows by giving irregularities to the surface of the tube, and conventionally known ones can be applied (for example, JP-A-6-13).
No. 9860). The take-up device 16 pulls the corrugated tube 20 from the bellows forming device 12 through the slit forming device 14, and causes the winding device 18 to take up the corrugated tube 20.

As shown in FIGS. 1 and 2, the slit forming device 14 includes a rotation support member 22 and a cutter support member 2.
4 is provided.

The rotation support member 22 is formed in a cylindrical shape having a tube insertion hole 23 in the center. A large-diameter portion 25 and a small-diameter portion 26 are formed on the rotation support member 22 in order from the upstream side in the transport direction of the corrugated tube 20, and the large-diameter portion 25 is supported on the ground side via a holder 28. . Specifically, the tube insertion hole 27 is also provided in the holder 28.
The tube insertion hole 27 and the rotation support member 2 are formed.
The holder 28 and the large diameter portion 25 are connected at a relative position where the second tube insertion hole 23 matches.

The cutter supporting member 24 is also formed in a cylindrical shape having a tube insertion hole (tube insertion passage) 29 at the center, and a large diameter portion 30 and a small diameter portion 31 are sequentially arranged from the upstream side in the conveying direction of the corrugated tube 20. Have. Large diameter part 30
Has an inner diameter larger than the outer diameter of the small diameter portion 26 of the rotation support member 22, and a bearing 32 is provided between the inner peripheral surface of the large diameter portion 30 and the outer peripheral surface of the small diameter portion 26. ing.
With this structure, the entire cutter support member 24 is rotatable around the central axis of the corrugated tube 20 inserted into the tube insertion holes 23 and 29 at a position where the tube insertion holes 23 and 29 coincide with each other (ie, the coaxial position). It is in a supported state.

A cutter insertion groove 33 extending in a direction inclined with respect to the axial direction of the corrugated tube 20 extends through the cylindrical wall of the small-diameter portion 31, and is parallel to and immediately adjacent to the cutter insertion groove 33. The cutter mounting wall 34 extending in the radial direction protrudes outward in the radial direction. A cutter 36 for forming a slit is inserted into the cutter insertion groove 33 from the outside, and is positioned at a position where it can be cut into the tube wall of the corrugated tube 20 in the tube insertion hole 29, and the cutter 36 is attached to the cutter mounting groove 33. Wall 34 and cutter clamping plate 38
And is fixed by bolts 37 and nuts 39 in a state of being sandwiched between them.

More specifically, bolt insertion holes are formed in the cutter mounting plate 34, the cutter 36, and the cutter holding plate 38, and a nut 39 is inserted into the bolt 37 with the bolt 37 inserted through the bolt insertion hole. By fastening the cutter 36, the cutter 36 is fixed to the corrugated tube 20 at a position where the cutter 36 can be cut in a direction inclined with respect to the axial direction.

Next, the operation of this device will be described.

The corrugated tube 20 that has been bellows formed by the bellows forming device 12 is pulled while being inserted into the tube insertion holes 27, 23, and 29 of the slit forming device 14 in order while the surface thereof is still relatively hot. Picking device 16
To be pulled in the axial direction. At this time, the cutter 36 cuts the corrugated tube 20 in a direction inclined with respect to the axial direction. Works. As a result, the cutter 36 and the cutter supporting member 24 rotate around the central axis of the corrugated tube 20 integrally (that is, the cutter 36 revolves around the central axis of the corrugated tube 20). Since the revolution of the cutter 36 and the corrugated tube 20 are performed at the same time, a spiral slit 40 as shown in FIG. 4 is automatically and accurately formed on the tube wall of the corrugated tube 20. Become.

That is, according to this method and apparatus, the slit 40 can be automatically formed with an inexpensive structure without using a special cutter turning device or control device.

In the above embodiment, the large-diameter portion 30 of the cutter supporting member 24 is supported by the small-diameter portion 26 of the rotation supporting member 22 from the inside. However, the rotation supporting member rotates the cutter supporting member from the outside. It may be configured to hold as possible.

In the above device, the cutter mounting wall 3
If the cutter 4 is configured to be rotatable around the axis in the tube radial direction with respect to the cutter support member 24, the cutter
6 can be changed, so that the helical pitch can be changed.

Further, in the embodiment shown in FIG. 3, the slit forming device 14 is incorporated in the corrugated tube manufacturing apparatus, and the corrugate is inserted in the tube insertion hole 29 by using the take-off device 16 installed in this manufacturing apparatus. Although the tube 20 is transported, the slit forming device 14 may be installed independently of the corrugated tube manufacturing device, and the corrugated tube 20 may be moved in the axial direction by a dedicated device.

[0024]

As described above, according to the present invention, the cutter for forming a slit is supported so as to revolve around a predetermined axis, and the cutter is cut into the corrugated tube in a direction inclined with respect to the axial direction. Since this corrugated tube is moved along the center axis of the cutter revolution, it does not use any special cutter revolution means or control means, has an inexpensive structure, and automatically and accurately,
There is an effect that a spiral slit can be formed in the corrugated tube.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line AA of FIG.

FIG. 2 is a plan view showing an example of a corrugated tube slit forming apparatus according to the present invention.

FIG. 3 is an overall view of a corrugated tube manufacturing apparatus provided with the slit forming apparatus.

FIG. 4 is a front view of a corrugated tube in which a spiral slit is formed.

[Explanation of symbols]

 14 Slit forming device 20 Corrugated tube 22 Rotation support member 24 Cutter support member 29 Tube insertion hole (tube insertion passage) 36 Cutter

Claims (2)

(57) [Claims] 1. A method of forming a spiral slit in a tube wall of a corrugated tube, comprising: supporting a cutter for forming a slit so as to revolve around a predetermined axis; A method for forming a slit in a corrugated tube, wherein the corrugated tube is moved along a revolving center axis of the cutter while being cut in an inclined direction. 2. A device for forming a spiral slit in a tube wall of a corrugated tube, wherein the corrugated tube has a tube insertion passage which can be inserted in the axial direction thereof, and is inserted into the tube insertion passage. A cutter support member that supports a slit forming cutter at a position where the corrugate tube can be cut in a direction inclined with respect to the axial direction, and a corrugated tube that is inserted into the tube insertion passage with the cutter support member. A corrugated tube slit forming device, comprising: a rotatable support member rotatably supporting around a central axis.