JPS5992122A - Manufacture of parallel corrugated pipe - Google Patents

Abstract

PURPOSE:To manufacture a high-quality parallel corrugated pipe of high mechanical strength that difficulty generates breakage, cracks etc. by thrusting a spiral, inward projected bar having a specified corrugation size against the outer peripheral wall of a circular pipe that advances in the axial direction. CONSTITUTION:A hollow columnar flyer 1 supported through a roller bearing 3 to a base stand 2 is rotated by a motor 7 through a pulley 6 and a circular pipe 4 is advanced in the direction of the arrow V guided by a guide sleeve 5 in the hollow part. At the same time, a corrugation die 9 provided with a corrugating projected bar 8 is eccentrically held by a die holder 10 attached to the flyer 1 through a roller bearing 11, and the die 9 is rotated by guiding the pin 23 of the die 9 guided by a long hole 22 formed in a bracket 21 attached to a holder 20. The projected bar 8 is spiralled having length of at least one pitch P, and F shown in the equation is set to 0.45 or less where D is the inner diameter of the projected bar 8, d is the outer diameter of the circular pipe, h is the height of corrugation to be formed and k=(D-d)/2+h.

Description

[Detailed Description of the Invention] [Technical Field] The present invention is applicable to the U method for manufacturing parallel corrugated tubes, mainly used for covering capes μ, etc., and coaxial capes! The present invention relates to a method for manufacturing a parallel corrugated tube, which is suitable for forming parallel annular corrugations on the outer periphery of a so-called corrugated tube, which is used as an external conductor in a corrugated tube.

[Prior art]

The conventional corrugating method is to feed the circular tube to be corrugated in its axial direction, and rotate the protrusion on the inner circumferential part of the die, which is cut into the outer circumferential wall, in the circumferential direction along the circumferential wall. something is known.

However, since the grooves formed by this method are spiral and continuous in the longitudinal direction, when the spirally corrugated tube is used as the outer conductor of the coaxial cape p, Since moisture easily enters the inside of the cape/L', it is necessary to circulate dry air inside the cape/L' or to use the cape non-connector as an air ventilation structure, which is complicated in terms of maintenance. Therefore.

In order to eliminate the above problem by interrupting the continuous blood flow in the longitudinal direction, parallel corrugated tubes in which a large number of independent circumferential grooves are formed parallel to each other in the circular tubes are used as the four external bodies, and the troughs of the chain tubes are A coaxial cable with a structure in which the wafer is cut into an insulator has been proposed, and a method (equipment) for manufacturing such a parallel corrugated tube has already been proposed (Special Publication No. 4 G-480
No. 69, JP-A-58-142965). However, when parallel corrugated tubes are manufactured based on these conventional examples, the parallel waves formed on the circular tube do not have a good finish, and not only do they become flat, but also scratches and dents occur. Since processing distortions remain in the waves, cracks are likely to occur during construction, and not only does it lack mechanical strength, but when used in coaxial cape ρ, it does not have a sufficient water-shielding effect. Not only was it not possible to obtain the desired electrical performance, but there were also some disadvantages such as not being able to obtain the desired electrical performance.

[Disclosure of the invention]

In view of the above-mentioned defective VC, the present invention provides a method for manufacturing a parallel corrugated tube that can easily obtain a corrugated tube having clean parallel waves without crushing, flattening, or scratches, and improves the quality of the parallel corrugated tube. The purpose is to improve.

In order to achieve the above object, the present invention processes an inward protrusion of a spiral cane having a length of at least one pitch and a smooth tip shape by corrugating the protrusion so as to have an outer diameter smaller than the inner diameter of the protrusion. This corresponds to the process of pressing the outer circumferential wall of the circular pipe and moving the pressed part in the circumferential direction of the circular pipe, and the progress of the spiral as the pressed part by the protrusion moves in the axial direction of the circular pipe. When the inner diameter of the protrusion is D, the outer diameter of the circular tube is 1, the height of the formed wave is h, and k is (D - d ) / + h. It is characterized in that the value of F given by , is set to be 0.45 or less.

[One embodiment of the invention]

First, a parallel corrugated tube manufacturing apparatus according to the present invention will be explained based on FIGS. fII, i, and FIG. The flyer 1, which has a hollow cylindrical shape as a whole, is mounted on a base 2 with rolling bearings 8.
A circular tube 4 to be corrugated and forcibly fed in the direction of arrow (2) (axial direction) is arranged in the hollow portion thereof. In the illustrated device, the circular tube 4
does not run directly in the hollow portion, but is guided by another hollow cylindrical guide sleeve 5. The pulley 6 to which the flyer IK is fixed is driven to rotate by a motor 7. A corrugated die 9 having a hollow cylindrical shape and having a spiral corrugating protrusion 8 having a hitch P on the inner circumferential wall.
is attached to the fryer 1 rotatably and eccentrically with respect to the center line of the circular tube 4. Wave dice 9
is attached to a die holder 10 tinted to the flyer 1 via a rolling bearing 11. Regarding the corrugating die 9 and the circular tube 4, the circular tube 4 is the corrugating die 9.
It is inscribed in the corrugated ridge 8 and is arranged in an arbitrary positional relationship such that the radially inner edge of the corrugated protrusion 8 matches the desired corrugated trough of the circular tube 4 during processing. There is. Furthermore, an elongated hole 22 is formed in the bracket 21 whose base is fixed to the fixed holder 20 and is elongated downward and opens toward the die 9, and a bottle 23 fixed to the die 9 is fitted into the elongated hole 22. By doing so, the dice 9 do not rotate but only revolve.

Next, a method of manufacturing a parallel corrugated tube according to the present invention using the apparatus shown in FIGS. 1 and 2 will be described.

Now, when the flyer 1 is rotated, the corrugated die 9 revolves around the outer periphery of the circular tube 4, applying corrugations to the circular tube 4'/c.
When the flyer 1 rotates once, machining of the next circumferential groove starts again on the circular tube 4. On the other hand, while the flyer 1 rotates once, the circular tube 4 is V by just one pitch P of the corrugated ridges 8.
Send it in the direction.

In the manufacturing method according to the present invention, as shown in FIG.
If p is the inner diameter of the circular tube 4, d is the outer diameter of the circular tube 4, and n is the wave height of the waves 12 (FIG. 1) formed, then the following conditions are essential. Note that point 01 is the center of the die 9, and point Oj is the center of the circular tube 4. If the distance between the bottom surface of the wave groove formed here and the center 02 is k, then D-Ll.

k= +h...(1) Here, if point 0+, which is the center of the protrusion 8, is the center of coordinates, the inner peripheral end of the protrusion 8 is expressed as x2+3''= (D/2)'. The locus of point 02, which is the center of circular tube 4, is x”+ (7−
k) ”= (d/2) ” terepresented by C (Actually, point O1 is the center of rotation). Therefore, in FIG. 8, both ends t1%tzIlffi of the contact portion between the protrusion 8 and the circular pipe 4
The distance 1iI11f is expressed by the following equation.

By dividing the distance f by the outer diameter d of the circular tube 4, an index force F is given.

It is an essential requirement of the present invention to set the F value determined by equation (3) to 0.45 or less.

In short, F≦0.45 is the key to misfire I11 V1.
Table 1 shows an example of the experimental results that serve as the basis for this. Note that the prototype AI and A8 are the conventional normal setting conditions. Also, the circular tube 4 here is a copper tape with a thickness of 0.4 to 0.5 mm and a diameter of 2.
6.5 mm and 14°2 mm VC-finished ones were used, and the die 9 had a 31-point shape shown in FIGS. 4 and 6 for one history.

・Table 1 As is clear from Table 1, when the F value exceeds 0.45 (AI, A4, etc.), the quality of the 5g corrugated product is poor, and the force (,0 , 45 or less (A2, A6, etc.), such a hand soldier C will not occur and 1
When a corrugated pipe of a certain quality could be obtained and aluminum or steel was used as the A factor, almost the same result C was obtained. Also, if a simple tube is manufactured and a corrugated tube is installed on the cable core of a coaxial cable, the power J! ! There was no difference &, 1 between the i case and the i case.

On the other hand, in order to manufacture coaxial cables with excellent water-shielding effects, the insulating layer is corrugated so that the troughs of the corrugations are sufficiently dug in. It was also confirmed that the radius 1-(1) of the tip stub of the strip 8 is desirably about 0.005 mIn.

[Effects of the present invention]

A spiral inward protrusion 8 having a length of at least one pitch and a sharp tip shape is corrugated into a circle 1′It4 having an outer diameter smaller than the inner diameter of the multi-strip 8. This corresponds to the step of pressing against the outer peripheral wall and moving the suppressed point in the circumferential direction of the tube 40, and the progress of the spiral as the suppressed point is moved by the projection 8 in the axial direction of the circular tube 4. The inner diameter D of the notched groove 8 is the outer edge of the circular tube, the height of the wave formed is h, and k is (D-2.d), /2+h. In this case, the value of F given by ) C is set to be less than 0.45, so the waves formed in the circular tube 4 have collapse, flattening, j
Because it does not cause scratches, it is less prone to cracks and has high mechanical strength.For example, when used in coaxial cables, it can produce cables with sufficient water repellency and excellent electrical performance. Another advantage is that high quality parallel corrugated tubes can be easily obtained.

[Another example]

1 (1) The corrugating die 9 is not provided with a bottle 28, and the die is rolled along one circumference of the circular tube 4 at Vζ1-.
A method of forming parallel waves in the circular tube 4 by rotation is also already known. Even if the present invention is adopted as the method, similar effects such as a high quality corrugated tube can be obtained.

(11) Circular tubes that can be used in the present invention include circular tubes that require ring-shaped parallel corrugations, such as the outer conductor of coaxial cables, the outer sheath for communication cables, waveguides, and general pipes. Bye.

(lft) The length of the protrusion 8 formed on the die 9 is not limited to 1,000 pitches, but may be any length as long as it is about the same length or more.

(1■) The amount of inward protrusion of the protrusion 8 may be small at the part where it first contacts the circular pipe 4, and may be increased at the part where it comes into contact later, so that the ripples are gradually deepened. .

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional side view of an apparatus for carrying out the manufacturing method according to the present invention, FIG. 2 is a view taken in the direction of the l arrow in FIG. 1, and FIG. 4 and 5 are a front view and a cross-sectional view showing an example of a die used in carrying out the present invention, and FIG. 6 is a sectional view showing an example of a protrusion. 4...
・Circular pipe, 8...Protrusion, D...Inner diameter of protrusion, d...
Outer diameter of circular pipe, h...Height of waves Figure 4 Figure 6 Procedural amendment 1 issue)' December 2z, 1980 Patent Application No.-26#)/Otsu No. 2, Issued Relationship with the case of the person who amended the manufacturing method of parallel corrugated tube 3 named by Ming. Patent applicant's office
8, Nishinocho, Higashimukojima, Amagasaki City Name (326) Representative of Dainichi Nippon Electric Cable Co., Ltd.
Representative Director Yukio Aoyama 4 Agent 5 Date of amendment order (shipment date) Month, Showa
Day 6, Correction target FXJ plane or above Figure 2 P δ δ

Claims (1)

[Claims] A circular tube to be corrugated with a spiral inward protrusion having a length of at least one pitch and a smooth tip shape and having an outer diameter smaller than the inner diameter of the protrusion. a step of pressing against the outer circumferential wall of the tube and moving the suppressed point in the circumferential direction of the circular tube, and feeding the circular tube in the axial direction at a speed corresponding to the progress of the rotation of the pressed point by the protrusion. When the inner diameter of the protrusion is D, the outer diameter of the circular tube is d, the height of the formed wave is h, and k is (D - d ) /2 + h, A method for manufacturing a parallel corrugated tube, characterized in that the value of F given is set to be 045 or less.