JP2598295B2 - Method of forming a polygonal flange at the end of a resin pipe - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for integrally forming a polygonal flange at an end of a thermoplastic resin pipe.

[Conventional technology]

When piping pipes that allow fluids such as gas or liquid to pass, or cable conduits in which wires or tapes slide, pipes are provided with retaining members at the ends to prevent pipe movement. . In such a case, if a polygonal flange is attached to the end of the pipe, it is possible to not only prevent the pipe from coming off but also easily prevent rotation and twisting.

When attaching a polygonal flange to the end of the resin pipe,
Conventionally, as shown in FIG. 4, a polygonal resin flange 41 having the same inner diameter as the pipe outer diameter is manufactured in advance by injection molding, machining, or the like, and the flange 41 is bonded to the pipe 42 with an adhesive 43 or Or a welding method using welding means such as high frequency or a high frequency method, or a method of forming a screw portion to be screwed together on the outer surface of the pipe 42 and the inner surface of the flange 41 as shown in FIG. Have been.

Further, a method is also adopted in which a pipe is set in a mold having a cavity in the shape of a polygonal flange, and a resin of the same material as the pipe is injection-molded on the outer periphery of the pipe to integrally form the flange.

In addition, Japanese Patent Application Laid-Open No. Sho 55-55 discloses a method in which an ultrasonic vibration is applied while the end of a resin pipe is pressed against a tool to soften the end, and the end of the resin pipe is bulged radially outward to form a locking portion.
It is disclosed in 117622.

[Problems to be solved by the invention]

However, the method of joining or welding the flanges with an adhesive is insufficient in strength, and the flanges may be detached by an external force. In the case of joining with a screw, the screw may be loosened when an external force that rotates in the circumferential direction of the pipe is applied. Also, since the flange and pipe must be joined after being formed in a separate process,
Inconveniences such as an increase in the number of parts and processing steps and an increase in cost arise. In addition, in the method of integrally molding a flange on the outer periphery of a pipe by injection molding, the pipe is deformed by resin pressure at the time of injection molding, and a process of inserting the pipe into a mold is required, so that processing cost is increased. There are drawbacks.

Further, the method disclosed in Japanese Patent Application Laid-Open No. 55-117622 discloses a method in which a resin pipe is softened by ultrasonic heating while a pipe end is pressed into a ring-shaped groove of a tool, and a ring-shaped locking portion is formed by plastic deformation. If you try to form a polygonal flange in this way, the corners of the flange will be rounded,
Polygon flanges with sharp edges cannot be obtained.

Accordingly, it is an object of the present invention to provide a method for integrally and efficiently forming a polygonal flange having a sharp edge at the end of a pipe.

[Means for solving the problem]

In view of the above problems, as a result of diligent research, the present inventors have formed a cavity in the shape of a polygonal flange on the upper surface of a pair of pipe holders, and provided an ultrasonic oscillator in the pipe portion protruding from the pipe holder. When the ultrasonic wave is oscillated while the horn is in contact with and pressed, the resin pipe ends are softened and melted by the ultrasonic vibration in the cavity, and a polygonal flange with sharp edges can be integrally formed. The inventors have found the present invention.

That is, the method of the present invention for integrally forming a polygonal flange having four to six corners at the end of a thermoplastic resin pipe includes:
(A) when the pipe is formed by a pair of pipe holders each having a polygonal flange-shaped cavity formed on an upper surface, a tip of the pipe is protruded by an amount corresponding to the polygonal flange; A horn of an ultrasonic oscillator having a lower end face sized to completely cover the cavity and having a pin which enters the inside of the cavity, and abutting the projection of the pipe, and (c) pressing the horn while pressing the horn. Ultrasonic waves are generated, and the softened and melted pipe projection is formed in the polygonal flange by the cavity sealed by the horn.

[Action]

In the method of the present invention, the end of the resin pipe is softened and melted by ultrasonic waves in the cavity in the shape of the polygonal flange, so that not only the pipe and the polygonal flange are completely integrated, but also the obtained is obtained. The edges of the polygonal flange are sharp.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of an apparatus for performing the method of the present invention. In FIG. 1, 1 is an ultrasonic oscillator for emitting ultrasonic waves of 15 to 30 KHz, 2 is a horn connected to the ultrasonic oscillator 1 for transmitting ultrasonic waves, and 3 is an ultrasonic oscillator and a horn for raising and lowering the horn. Air cylinder. 4a, 4b are pipe holders for holding the resin pipe end, for example, 4a is fixed, 4b
Can slide sideways. 4 while holding the resin pipe
Fix the pipe by tightening a and 4b. In this embodiment, a cavity 5 having a desired polygonal flange shape is formed at a predetermined depth on the upper surfaces of the pipe holders 4a and 4b as shown in FIG. Further, a pin 6 is provided at the tip of the horn 2 to prevent the pipe end from entering the resin pipe and deforming the pipe end inward during the formation of the polygonal flange.

In order to carry out the method of the present invention, first, the end of the resin pipe 7 is protruded from the upper surface of the holder 4a, 4b by an amount corresponding to the polygonal flange (a few mm), and the resin pipe 7 is fixed by the holder 4a, 4b. I do. Next, the ultrasonic oscillator 1 and the horn 2 are lowered by operating the air cylinder 3, and the horn 2 is brought into contact with the terminal of the resin pipe 7. Then, when the ultrasonic wave is oscillated for 0.3 to 10 seconds, the ultrasonic wave is transmitted from the horn 2 to the pipe end,
Heat is generated from the inside of the pipe, the pipe end is softened and melted, and the horn 2 descends until it contacts the holders 4a and 4b. The resin softened and melted in this state is supplied to the horn 2 and pipe holder 4
Since the inside of the polygonal flange-shaped cavity 5 completely sealed with a and 4b is filled, the flange is formed according to the shape of the cavity. The stroke of the air cylinder 3 is adjusted so that the descent stops when the horn 2 hits the holders 4a and 4b. The horn 2 is left for 0.5 to 20 seconds in a state where the horn 2 is in contact with the upper surfaces of the holders 4a and 4b to cool and solidify.
Thereafter, the air cylinder 3 is operated in the reverse direction to return the horn 2 to the original position, and the holding members 4a and 4b are opened to take out the pipe.

In this way, as shown in FIG.
A pipe having a sharp edged polygonal flange 8 formed at the end of the pipe can be obtained.

Hereinafter, embodiments of the present invention will be described in more detail with reference to specific examples.

Example 1 Outer diameter 12.5 mm, inner diameter 9.5 mm, length 100 made by extrusion molding
A hexagonal flange was formed at the end of a 0-mm polyethylene pipe by the following procedure using the apparatus shown in FIG.

First, a pipe holder with a hexagonal flange cavity with a width of 15 mm (distance between opposing sides) and a depth of 3 mm on the upper surface
By 4a and 4b, the pipe tip was fixed so as to protrude 5 mm from the upper surface of the pipe holders 4a and 4b. Next, the air cylinder 3 was operated to lower the ultrasonic oscillator 1 and the horn 2, and the horn 2 was brought into contact with the pipe end. afterwards,
While oscillating a 20 KHz ultrasonic wave for 1 second, lower the horn 2 until the tip of the horn hits the upper surfaces of the pipe holders 4a and 4b.
After leaving for 2 seconds, the softened and melted resin in the cavity was cooled and solidified. Finally, raise horn 2 and hold 4
a, 4b was released and the pipe was taken out.

The end of the pipe obtained in this way has a width of 15 mm,
A sharp hexagonal flange with a thickness of 3 mm was formed. A shearing force was applied to the flange portion of the hexagonal flanged polyethylene pipe in the longitudinal direction of the pipe, but the flange portion was not broken, and the pipe body was cut. Also, an M10P1 male thread was machined at the end of the pipe without the flange, and a spanner was screwed into the female thread over a hexagonal flange. Could be combined.

As described above, the present invention has been described with the above embodiments. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of the concept of the present invention. For example, instead of raising and lowering the horn of the ultrasonic oscillator, the pipe holder may be raised and lowered.

As the resin forming the pipe, a general thermoplastic resin such as polypropylene, polyamide, polystyrene, modified polyphenylene oxide, polycarbonate, and polyvinyl chloride can be used in addition to polyethylene.

〔The invention's effect〕

According to the method of the present invention, an arbitrary polygonal flange can be formed completely integrally by variously changing the shape of the cavity formed in at least one of the horn and the holder. The obtained polygonal flange does not break or fall off even when an external force is applied, and has sufficient strength. Moreover, the end of the pipe can be transformed into a polygonal flange in a short time within several seconds, the number of parts can be reduced, and the polygonal flange can be formed at low cost.

Furthermore, since not only the softening but also the melting is performed in the cavity, there is an advantage that the corner is not rounded and a polygonal flange having a sharp shape can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an apparatus for integrally forming a polygonal flange by the method of the present invention, and FIG. 2 is a plan view showing an example of a polygonal flange cavity formed in a pipe holder. FIG. 3 is a perspective view showing an example of a thermoplastic resin pipe with a polygonal flange formed by the method of the present invention, and FIG. 4 is a perspective view showing a conventional example in which a flange is bonded to the outer periphery of the pipe. FIG. 5 is a cross-sectional view showing a conventional example in which a flange is screwed on the outer periphery of a pipe. DESCRIPTION OF SYMBOLS 1 ... Ultrasonic oscillator 2 ... Horn 3 ... Air cylinder 4a, 4b ... Pipe holder 5 ... Polygon flange cavity 6 ... Pin 7 ... Resin pipe 8 ... Polygon flange

Claims (1)

(57) [Claims] 1. A method for integrally forming a polygonal flange having four to six corners at an end of a thermoplastic resin pipe,
(A) when the pipe is held by a pair of pipe holders having a cavity in the shape of a polygonal flange formed on the upper surface, the tip of the pipe is protruded by an amount corresponding to the polygonal flange; A horn of an ultrasonic oscillator having a pin that enters the pipe and having a lower end surface large enough to completely cover the cavity is brought into contact with the protrusion of the pipe, and (c) pressing the horn Forming a softened and melted pipe projection in the polygonal flange by means of the oscillating ultrasonic waves and the cavity thus sealed by the horn.