JPS61241587A - Method of connecting synthetic resin pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention allows for easy joining of synthetic resin pipes, and also provides strong connection force by making the inner circumferential surfaces of the pipe joints flush. Regarding the law.

(Prior art) Conventionally, to connect synthetic resin pipes such as vinyl chloride resin,
A pipe fitting with a sleeve socket is used.

The inner circumferential surface of this pipe fitting has a tapered surface whose inner diameter decreases from the open end toward the back, and the inner diameter at the back of the tapered surface is slightly smaller than the outer diameter of the synthetic resin pipe to which it is connected. There is.

Therefore, when connecting a synthetic resin pipe to this pipe joint,
After applying adhesive to the inner peripheral surface of the socket of the pipe joint and the outer peripheral surface of the end of the synthetic resin pipe, the end of the synthetic resin pipe is pushed into the socket, and the outer diameter of the synthetic resin pipe is reduced by elastic force. was further press-fitted deep into the socket to join.

(Problems to be Solved by the Invention) However, in the case of connecting synthetic resin pipes using this conventional pipe joint, when the end of the synthetic resin pipe is press-fitted into the socket, the inner peripheral surface of the socket and the synthetic resin pipe The adhesive applied to the outer circumferential surface of the end of the pipe is scraped off, and this adhesive protrudes onto the inner circumferential surface of the pipe joint, resulting in a bead.

This bead of adhesive obstructs the flow of fluid in the pipe, reducing the flow rate, and the fluid in the pipe remains in this area, causing bacteria and algae to adhere. Furthermore, there is a problem in that the adhesive solvent flows out from the bead and contaminates the fluid within the pipe.

Therefore, this conventional pipe joint was not suitable as a piping material for ultrapure water equipment for cleaning electronic parts such as semiconductors.

(Means for Solving the Problems) The present invention solves the drawbacks of such conventional pipe joints, and includes a collar protruding from the outer peripheral surface of the ends of both synthetic resin pipes to be butted and joined, A holding member is secured to the back surface of each brim, and the synthetic resin pipes are butted and connected by the tightening action of the holding member.

The brim is formed by welding a separate synthetic resin ring to the outer periphery of the end of the synthetic resin pipe, or by heating and melting the end of the synthetic resin pipe and bending the pipe end toward the outer periphery. Shape.

In the former case, the outer circumferential surface of the end of the synthetic resin pipe and the inner circumferential surface of the synthetic resin ring are simultaneously heated and melted using a heater, and then the heater is removed and the ring is attached to the outer circumferential surface of the end of the synthetic resin tube. Weld to.

In the latter case, the end of the synthetic resin pipe is heated and softened, a preform mold is press-fitted into the end of the pipe to expand it, and then the mold is inserted into the expanded part and the expanded part is expanded. A pressing mold is applied to the back surface of the pipe, and the expanded portion is pressed between the mold and the pressing mold and bent until it is perpendicular to the tube axis to form a collar.

On the other hand, to connect synthetic resin pipes with flanges at their ends, a holding member consisting of a splittable ring body is used, and the split ring body is straddled over both flanges and tightened in the radial direction. The slanted protrusions provided on the inner surfaces of both ends of the ring body are used to firmly press the back surfaces of the respective flanges to connect them.

Alternatively, using a holding member consisting of a pair of loose flanges and a stay bolt that connects them, the loose flanges are inserted into each synthetic resin pipe, and then both loose flanges are tightened and connected with the stay bolts.

(Function of the invention) In the connection method of the present invention, flanges are provided protruding from the outer circumferential surfaces of the ends of the synthetic resin pipes to be butt-jointed, and both flanges are tightened with a holding member to connect the fixed length tubes. It is extremely easy to connect pipes cut to any length, and
It also provides a strong connection.

Moreover, in the present invention, since the pipes are connected by mechanical means without using adhesive, there is no risk of adhesive beads forming on the inner circumferential surface of the pipe joint as in conventional pipe joints. The inner peripheral surface of the joint can be made flush.

For this reason, the connection method of the present invention is suitable for connecting pipes of ultrapure water equipment for cleaning electronic components such as semiconductors.

Hereinafter, the specific configuration of the present invention will be explained based on examples.

(Example 1) Figures 1 to 71 show an example of the present invention,
Figure 1 is a partial cross-sectional front view showing how synthetic resin pipes are connected to each other, Figure 2 is a side view of Figure 1, and Figures 3 and 4 are the process of protruding a collar on the outer peripheral surface of the end of a synthetic resin pipe. FIG.

In the figure, numeral 1 is a synthetic resin tube, 2 is a collar, 3 is a rubber backing, and K is a holding member.

The synthetic resin tube 1 is a tube made of vinyl chloride resin, polyethylene resin, polypropylene resin, etc., and a collar 2 is provided protruding from the outer peripheral surface of the end of the limb tube 1.

The collar 2 is made by welding a ring 2a made of the same type of synthetic resin as the synthetic resin tube 1 to the outer peripheral surface of the tube end, and its negative side is a vertical surface flush with the end surface of the tube 1. Its back surface is a slope.

On the other hand, the holding member has v! The ring body 4 having an inner diameter slightly larger than the outer diameter of the ring body 42 is divided into two parts, and the inner surface of both ends of the ring body 4 has inclined protrusions 41.41 that abut against the back surface of the collar 2.2. It is provided.

One end of this split ring body 4 is rotatably joined by a pin 40, and seven flange 42, 42 protrudes from the other end.
A bolt 5 is inserted through the bolt 5, and the nuts 1 to 6 are screwed onto the bolt 5.

Next, the procedure for connecting the ζ synthetic resin pipe will be explained based on FIGS. 1 to 4.

First, a collar 2 is provided on the outer peripheral surface of the end of the synthetic resin pipe 1. In this two-piece flange molding, a ring 2a made of the same type of synthetic resin as the synthetic resin pipe 1 is prepared, and the inner diameter of the ring 2a is made almost equal to the outer diameter of the synthetic resin pipe 1, and the side surface thereof has an inclined surface. will be established.

Next, as shown in FIG. 3, the outer circumferential surface of the end of the synthetic resin tube 1 and the inner circumferential surface of the ring 2a are simultaneously heated and melted by a heater H. At this time, the outer peripheral surface of the end of the synthetic resin pipe 1 is heated and melted so that it becomes a tapered surface, while the inner peripheral surface of the ring 2a is heated and melted so that it becomes a tapered surface that matches the tapered surface. It's good to let them do it.

After heating and melting each joint surface in this way,
Remove the heater 1 and attach the ring 2a to the synthetic resin pipe 1.
When the synthetic resin tube 1 is inserted onto the outer circumferential surface of the end and melted, m2 is formed on the outer circumferential surface of the end of the synthetic resin pipe 1, as shown in FIG.

Next, if the ends of this synthetic resin pipe 1.1 are brought together,
After interposing the rubber backing 3 at the end of the tube, the split ring body 4 is straddled over both flanges 2.2.
and nuts 6 are screwed together to tighten the split ring body 4 in the radial direction. Join.

(Example 2) Figures 5 to 7 show other examples of the present invention,
Figure 5 is a partial cross-sectional front view showing the connection state of synthetic resin pipes;
FIGS. 6 and 7 are cross-sectional views showing the process of forming a collar by bending the end of a synthetic resin pipe toward the outer circumference.

In this embodiment, flanges 20 are provided by bending the ends of a synthetic resin pipe 1 toward the outer circumference, and a holding member K consisting of a pair of loose flanges 7.7 and a stay bolt 8 is locked to each flanges 20.20. The pipes are connected together.

In the case of this embodiment, the collar 20 is molded in the next molding step.

First, after heating and softening the end of the synthetic resin pipe 1 to a predetermined length, a preform M is press-fitted into the end of the pipe, and a sixth
As shown in the figure, the tube end is expanded into a tapered or trumpet shape.

Next, as shown at No. 1 in FIG. 7, a mold N is inserted into this expanded portion, and a press mold P is inserted onto the synthetic resin pipe 1. Since the mold N is heated to a temperature higher than the melting temperature of the synthetic resin pipe by the built-in heater, when the mold N comes into contact with the expanded portion, the expanded portion is further heated and softened.

Therefore, the suppressing die P is moved to the side of the forming die N, and the expanded portion is compressed between the press die 1] and the forming die N and bent until it becomes a vertical plane perpendicular to the tube axis.

After molding the collar 20 on the end of the synthetic resin pipe 1 in this way,
When the loose flanges 7 are inserted onto the synthetic resin pipes 1, the stay bolts 8 are passed through the respective loose flanges 7.7, and the nuts 1-0 are screwed onto the stay bolts 8, the pipes are firmly joined together.

In the above-described first embodiment, a separate synthetic resin ring 2a is welded to the outer circumferential surface of the end of the synthetic resin pipe 1 to provide a protruding collar 2, and a retainer made of the split ring body 4 is attached to the collar 2. Although the holding member K is shown as an example, the holding member K consisting of the loose flange 7 and the stay bolt 8 of the second embodiment may be used instead of the holding member K. Furthermore, in Example 2,
A holding member K consisting of a loose flange 7 and a stay bolt 8
A holding member K consisting of the split ring body 4 of Example 1 instead of
The tubes may be connected using a

(Effects of the Invention) As described above, the connection method of the present invention includes protruding a collar on the outer peripheral surface of the end of a synthetic resin pipe, and then butting the pipes together.
Since the holding members are simply engaged with the respective flanges and tightened, the connection operation is extremely simple and a strong joint can be obtained.

Furthermore, since the connection method of the present invention connects pipes using mechanical means, there is a risk that the adhesive may protrude onto the inner circumferential surface of the pipe joint, or that the solvent of the adhesive may flow out and contaminate the fluid inside the pipes. Not at all. Therefore, the connection method of the present invention is particularly suitable as a connection method for piping of an ultrapure water apparatus for cleaning electronic components such as semiconductors.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention, in which Figure 1 is a partially sectional front view showing the state of connection of synthetic dendritic tubes, Figure 2 is a side view of Figure 1, and Figure 2 is a side view of Figure 1; Figure 3 is a cross-sectional view of the process of heating and melting the outer peripheral surface of the end of a synthetic resin pipe and the inner peripheral surface of a synthetic resin ring using a heater, and Figure 4 is a sectional view of a process in which a collar is protruded from the outer peripheral surface of the end of a synthetic resin pipe. FIG. 5 to 7 show other embodiments of the present invention,
Figure 5 is a partially sectional front view showing how synthetic resin pipes are connected to each other, Figure 6 is a sectional view showing the end of the synthetic resin pipe expanded in a preforming mold, and Figure 7 is a mold and press FIG. 6 is a cross-sectional view showing a step of forming a collar by compressing the expanded portion with a mold and bending it until it is perpendicular to the tube axis. 1...Synthetic resin pipe 2.2o...Brim 2a...Synthetic resin ring 3...Rubber backing 4...Divided ring body 41... Slanted protrusion 42... 7 Lunge 5... Bolt 6... Nut 7... Loose flange 8... - Stay bolt 9...Nut K...Holding member TODO...Heater M...Preforming mold N...Molding mold P.・・・・・・Press type

Claims (1)

[Claims] 1. Flanges are provided protruding from the outer circumferential surfaces of the ends of both synthetic resin pipes to be butt-connected, and a holding member is secured to the back surface of each collar, and the tightening action of the holding member is applied. A method for connecting synthetic resin pipes, characterized in that the pipe end faces are butted against each other and connected. 2. A collar is provided by heating and melting the outer peripheral surface of the end of the synthetic resin pipe and the inner peripheral surface of the synthetic resin ring using a heater, and welding the ring to the outer peripheral surface of the end of the synthetic resin pipe. A method for connecting synthetic resin pipes according to claim 1. 3 Heat and soften the end of the synthetic resin pipe, press fit the pipe end into a preforming mold and expand it, then insert a mold into the expanded part and place a pressing mold on the back of the expanded part. The synthetic resin pipe according to claim 1, characterized in that the expanded portion is pressed between a molding die and a pressing die and bent until perpendicular to the tube axis to provide a flange. Connection method. 4 The holding member consists of a ring body that can be divided, and when the ring body is straddled over the outer circumferential surface of the brim of both abutted synthetic resin pipes and tightened in the radial direction, the inner circumference of both ends of the ring body is tightened. Claims 1 and 2 are characterized in that the provided inclined protrusions strongly press the back surface of each collar to connect the pipes.
The method for connecting synthetic resin pipes according to item 1 or 3. 5. Claims 1 or 2, characterized in that the holding member is comprised of a pair of loose flanges fitted onto respective synthetic resin pipes, and a stay bolt connecting the loose flanges. The method for connecting synthetic resin pipes according to item 3.