JPS60225731A - Bending of synthetic resin tube - Google Patents

Abstract

PURPOSE:To obtain a desired bend with ease by a method wherein a bending jig tied on a pressure resistant hose is inserted through a synthetic resin tube and then, the pressure resistant hose is bent as specified after a high-pressure fluid is introduced thereinto to maintain a specified sectional shape. CONSTITUTION:In a bending jig 1, a plurality of flexible polyethylene sheet plates 3 which are formed in thin strips are arranged slightly separate therebetween to be laminated on the circumferential surface of a pressure resistant hose 2 made of rubber slightly expandable by an internal pressure while being brought into contact with the said circumferential surface parallelling the axis of the pressure resistant hose 2. The outer diameter thereof shall be roughly the same as or slightly smaller than the inner diameter of the work, a synthetic resin tube 7 as straight tube. Air of a specified pressure is introduced into an end pressure hose 2 of the bending jig 1 inserted into the synthetic resin tube 7 to expand the diameter thereof slightly through a pressure resistant piping 5 and a valve device 6 is closed through the pressure resistant piping 5 to seal up air of a specified pressure into the pressure resistant hose 2. Then, the operation is shifted to the bending process.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is based on the primary processing of thermoplastic synthetic resin pipes.
The present invention relates to a secondary addition L method in which a cross-sectional shape such as a perfect circle is maintained and curved to form a predetermined curved pipe.

[4. Next technology] Synthetic tree V! 4. A method for manufacturing bent pipes: - After bending the straight pipe of the product, heat and soften the 111 parts, and then add sand, synthetic resin particles, etc. Pressure filling (
In order to prevent the pipe from collapsing and deforming its cross-sectional shape during the bending process, the pipe can be bent secondarily by inserting a spring steel or rubber rod, etc., or by applying air to the inserted rubber duplex. Iy addition-[Ijruij 11, was common.

(Problems to be Solved by the Invention) In the conventional method for bending synthetic resin pipes as described above (1), for example, sand or synthetic resin particles are pressurized and filled into the synthetic resin pipe.
In the ILNO'C method, it is troublesome to handle the filling sand and synthetic resin particles, and the bending part is heated and softened unevenly. The desired curve may not be obtained due to different degrees of bending due to the bending process.Also, when using a bending jig, which involves inserting a spring steel or rubber rod into a synthetic resin pipe, a large amount of force is required during the bending process. If the radius of curvature of bending 1 is small, it may be difficult to insert and remove the bending jig after hardening. The 7'J method is also
There have been problems such as not being able to obtain a uniform curve without a penetrating object that serves as a bending ruler, but the present invention attempts to solve these problems. The object of the present invention is to provide a method for bending a synthetic resin pipe that can be maintained and easily obtain a desired bent pipe.

(Means for Solving the Problems) As a means for solving the above problems, the present invention has J.
3. After inserting a flexible bending jig with an outer diameter that approximately matches the inner diameter of the synthetic resin pipe into the straight synthetic resin pipe that is the workpiece, the synthetic resin pipe is In a method of bending synthetic resin pipes to obtain bent pipes by applying an external force to the ends, a plurality of narrow flexible thin plates are placed on the outer circumferential surface of a pressure hose, each having a resistance of 11°C. Hose shaft and flat T]k-lay <'tlQ (Multiple layers are arranged, and the outer diameter approximately matches the inner diameter of the synthetic resin pipe.
] Insert the two-sided shell into the synthetic resin pipe, then introduce rI + pressure fluid into the front nL pressure-resistant small space, and then bend it to a predetermined hanging curve.
l. In this state, the bending portion of the synthetic resin pipe is solidified to obtain a bent pipe.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for bending synthetic resin pipes according to the present invention will be described below with reference to the drawings.

Figures 1 and 2 show a bending jig for secondary processing of a straight pipe with an approximately perfect circular cross section, which is used in the bending process of the present invention. A thin plate 3 made of poly(11)lene formed into a narrow rectangular shape and having a flexible layer f[h] is placed on the outer peripheral surface of a pressure-resistant boss 2 made of rubber or the like that can be expanded slightly by internal pressure.
Multiple sheets, between 3 phases and 71: 2. J+t
PJl time! , ff1l to f tt Z' h
The shaft of the ff4 IJ water hose becomes 5P f-i.
,・) to the front mu [1 outer circumference direction closeness 1! A plurality of thin plates 3 are arranged in the same manner on the outer circumferential side of the thin plates 3, and the outer diameter of the thin plates 3 is approximately the same as the inner diameter of the straight synthetic resin pipe to be joined. J, sea urchin f11iF1 that becomes Wang Kodia
Sheet (Yes, these laminated thin plates 3 can be attached to a tightening device 4 such as a string.
These thin plates 3 are loosely bundled at
Both ends 2a, 2a of the pressure-resistant hose 2 extending from both ends of the pressure-resistant hose 2 are closed. 11 pipes 5, 5 that come out from inside with υ1 are connected to 1. The filJE pipes 5 and 5 are equipped with valve-equipped stomachs 6 and 5, respectively.
This bending jig 1 is realized by interposing the bending tool 6.

Manoko Figure 3 is Figure 1 JJ J, and Figure 2 1. , - Performed using a small bending and pressing jig (7) An example of the processing method according to the present invention is performed using a small one, first, bending is performed to a predetermined length, and then the bending is applied A synthetic resin pipe 7, such as a polyvinyl chloride pipe, is subjected to a certain bending process to make it longer than the entire length of the synthetic resin pipe 7. 1, and both ends of this bending and pressing jig 1 are extended from both ends of the synthetic resin pipe 7.

Next, a predetermined amount of air is introduced into the pressure-resistant hose 2 of the bending jig 1 inserted into the synthetic resin pipe 7 through the pressure-resistant piping 5, and the diameter is slightly expanded. WII&
3 in close contact with the inner circumferential surface of the synthetic resin pipe 7, close the valve device 6 installed in the pressure-resistant pipe 5, and enclose a predetermined amount of J-[a] in the pressure-resistant hose 2. Move to bend 1 culm.

The bent L culm can be bent by various means (for example, as shown in 1), after gripping and fixing the ends 7a of the synthetic resin pipe L to the fixing jig V18, the other End 7 [) of
A force f1 is applied from the side to bend it for a predetermined period. At this time, when the bending force is applied, the narrow thin plate 3, which is bundled in multiple layers on the outer circumferential surface of the bending jig 1 and which forms the Ic flexible bamboo, is formed by the synthetic resin tube 7. However, the adjacent thin plates 3 are arranged with a slight distance from each other, and the surfaces of the thin plates 3 are smooth, and when laminated, the Since the frictional resistance is low, it can be easily bent with a small force, and since the outermost surface of the long thin plate 3, which is laid out in several layers, plays the role of a bending ruler, the area R is the bending part. The part has a uniform curvature [・Bending addition 1 (-toga-(there,.

Then, fix the end 7b side of the synthetic resin pipe 7 to maintain this curved state with a cap (4 (Fig. small t! IF). If a dent or the like occurs, increase the air pressure in the pressure hose 2 of the bending jig 1 to restore it to its normal shape.
What can you do? .

As mentioned above, the synthetic resin pipe 7 is fixed by bending it by a predetermined amount, and is left covered for a certain period of time, or cooled with cold air or cold water.
Heat softening 1 (after solidifying the curved part, resistance f1
Open the valve device 6 on either side of the pipe t) and discharge the valve 17 from the inside of the pressure-resistant boss 2 through the inside of the synthetic resin pipe 7, which has been reduced in diameter and bent. By pulling out the bending and pressing jig 1 and removing it from the identification jig 8, the synthetic resin pipe 7 is made into a desired bent pipe.

In this embodiment, the bending portion of the synthetic resin pipe 7 of Fj Y', + is heated and softened in advance. After inserting the bending press jig 1, the bending part of the synthetic resin pipe 7 is heated and softened after the bending jig IA1 is inserted.
However, you can add it by opening the book.

(Effects of the Invention) As described below, in the method for bending synthetic resin pipes according to the present invention, a plurality of flexible sheets are attached to the outer circumferential surface of the pressure-resistant bow.
- Arrange several layers of narrow thin plates, each lined up parallel to the inside of the N-resistant hose, so that the outer diameter of the thin plate is approximately equal to the inner diameter of the synthetic resin pipe. Insert the tube into the synthetic resin pipe, then introduce the HEL fluid into the N-resistant hose, and then bend it by a predetermined amount, and in this state, assimilate the bent part of the synthetic resin pipe to create a bent pipe. 4'/ruJ,・)
(The bending mechanism has a structure made of thin thin plates that provide flexibility, so it is easy to bend. Therefore, it is easy to add curved pipes to curved pipes with various shapes. ]-Deki, maiko bending-1
- Introduced into the pressure-resistant hose in the jig (covering i+)) Since an appropriate internal pressure can be maintained by the I fluid, dents are less likely to occur in the curved part, and even if a dent etc. occurs, after one culm of bending, the pressure-resistant hose By increasing the pressure, it becomes the regular staff shape once.
It has excellent effects such as being able to be processed into curved pipes with a beautiful appearance.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, Figures 1 and 2.
The figure shows an example of a bending jig used in the method of the present invention,
Figure 1 is a perspective view of the suspension, Figure 2 is an end view, and Figure 3 is the bending of a synthetic 4#4 fat pipe using this bending jig.
1 is an explanatory diagram of method 1. 1 is a bent 1-metal shell, 2 is a pressure-resistant hose, 3 is a thin plate, 4 is a tight seal, 5 is 1F-resistant piping, 6 is a valve device, 7 is a synthetic resin pipe, 7a and 7b are ends, 8I, 1 It is a fixing jig.

Claims (1)

[Claims] 1. A flexible bending jig is inserted into a straight synthetic resin pipe as a workpiece so that the outer diameter approximately matches the inner diameter of the synthetic resin pipe. , by applying an external force to the end of this synthetic resin tube to bend it. A bending jig is inserted into the synthetic resin pipe by inserting a bending jig that is tightened to the pressure hose so that its outer diameter approximately matches the inner diameter of the synthetic resin pipe. Then, after introducing high-pressure fluid into the pressure-resistant hose, it is bent to a predetermined distance to solidify the bent portion 4i1 of the synthetic resin pipe in this state C. J-method for bending synthetic resin pipes.