JP2003001348A - Method for manufacturing joint for flexible tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a joint for a flexible tube which lessens working steps and enhancing productivity by using press forming so as to cut costs, provides high forming accuracy and securely performs a function of stopping the joint from coming off. SOLUTION: A cup-shaped article is manufactured by the press forming of a steel plate. Then a ring-shaped groove 2h is provided on the head of the article. A through hole 3f is made inside the ring-shaped groove. The article is made cylindrical by drawing it from its inside with the burring process. Then a stopper 5k for the joint Z is formed by radially folding the end of the side wall of the article outward along the ring-shaped groove 2h.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a flexible pipe joint and a method for fixing the joint to the flexible pipe.

[0002]

2. Description of the Related Art A bellows-shaped flexible pipe having a corrugated uneven cross section is used for applications such as a water pipe and a gas pipe, and its end portion has a cylindrical shape. Conventionally, a joint used for such a flexible pipe has a through hole formed by cutting an extremely thick metal material having a predetermined length, and a retainer and a flange protruding radially outward at both ends of the metal material. It was manufactured by cutting the outer surface of the metal material into a cylindrical shape so as to form the.

Further, when a flexible pipe is installed, it is usual to cover the flexible pipe with a net pipe as a pipe-shaped protective material in order to protect the flexible pipe. Conventionally, the net pipe is a cylindrical joint. The main body is covered, and then the ring-shaped fixing member is passed through, the fixing member is arranged on the main body of the joint, and the main body of the joint fixes the fixing member, the net pipe, and the joint by welding. Then, the flexible pipe and the joint are fixed by welding the contact portion between the inner peripheral surface of the joint and the outer peripheral surface of the flexible pipe cylindrical portion.

[0004]

However, in the conventional method of manufacturing a joint by cutting a metal material, a large number of cutting portions and a large amount thereof cause a great amount of shavings. Further, the inside must be hollowed out to form a tubular shape, and the outer surface must be uniformly cut so as to form a cylindrical shape to form a retainer, etc., which requires extremely complicated work and skill. Therefore, if a joint is manufactured by this method,
There were problems of low productivity and high cost.

Further, in order to solve this problem, a thick steel plate is formed into a cylindrical molded product by press molding or burring, and the opening of the molded product is pressed as it is to project outward in the radial direction. Although a method of forming a retainer is conceivable, it is difficult to form the retainer uniformly along the circumferential surface when forming the retainer, and the retainer is formed well. Even if it is possible, the bent portion of the retainer becomes an arc shape, and the function as the retainer is weakened.

The present invention has been made in view of the above circumstances, and by using press molding, the number of working steps can be reduced, productivity can be increased, and cost can be reduced.
An object of the present invention is to provide a method for manufacturing a flexible pipe joint that has a high molding accuracy and exhibits a reliable retaining function.

Further, the conventional method of connecting the joint to the flexible pipe has a problem in that the protective material covering the flexible pipe is easily removed and the flexible pipe cannot be reliably protected. Further, since welding is used in the conventional method, this welded portion causes rust, which causes a problem that rust is mixed into tap water passing through the flexible pipe.

Another object of the present invention is to prevent the protective material from coming off and prevent the flexible pipe from being damaged.
The main aim is to completely eliminate the welding that causes rust.

[0009]

In order to solve the above-mentioned problems, in the method for manufacturing a flexible pipe joint according to claims 1 and 2, a thick steel plate is press-formed to form a bowl-shaped molded product, After that, a ring-shaped groove is provided in the head of the molded product. Then, a through hole is bored inside the ring-shaped groove, the molded product is pierced from the inner side by burring to form a cylindrical shape, and then the side wall end of the molded product is bent outward along the ring-shaped groove. By doing so, the retaining feature of the joint is formed.

Further, in order to solve the above-mentioned problems, the invention of claim 3 applies pressure from above a fixing member for fixing the net pipe, so that the fixing member, the net pipe thereunder, and the joint body portion are fixed. It is also characterized in that the joint is fixed to the flexible pipe without using any welding at the same time, by fixing the joint more firmly than the conventional method.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The "method for manufacturing a joint for a flexible pipe" and the "method for fixing a joint to a flexible pipe" according to the present invention will be described in more detail below.

FIG. 1A is a view showing a step of forming a thick steel plate by press working, and FIG. 1B is a view showing a first formed product W1 formed by the step. .

In FIG. 1 (A), 1a is a processed plate,
1b is a first die, 1c is a first die body portion, 1d is a concave portion,
Reference numeral 1e is a first die extension portion, 1f is a first punch, 1g is an outer pressing die, 1h is an inner pressing die, 1i is a spring provided below the inner pressing die, 1j is a cut provided on the die body. Blade, 1k is a cutting blade provided in the presser die, 1m is the first shank, 1n
Is a first upper die holder, 1p is a first die plate, 1r is a pushing member, 1s is a compression spring provided above the pushing member, 1t is a first punch plate, and 1u is a first pedestal.

In the present embodiment, the processed plate 1a is made of a thick steel plate having a thickness of about 3 mm. The material, thickness, etc. of the processed plate 1a are appropriately changed depending on the type of joint to be manufactured.

In this step, the first die 1b is placed above the first die 1b.
The punches 1f are coaxially installed below. First
The die 1b includes a first die body portion 1c having a substantially columnar shape and a first die extension portion 1 extending from a top end of the first die body portion 1c toward an outer side in the radial direction.
e. The lower surface of the first die body portion 1c is provided with a substantially hemispherical recess 1d opening downward, and the lower end of the outer peripheral surface of the first die body portion 1c is provided with a cutting edge 1j along the outer periphery thereof. It is equipped.

Further, in the columnar space provided inside the first die 1b, there is provided a pushing member 1r which is provided with a compression spring 1s above and which is vertically movably mounted.
The pushing member 1r has a pin portion. The pin portion of the pushing member 1r is the recess 1d of the first die body 1c.
Projecting downward from a hole provided in the first die 1b
It is set so that when is pressed to the maximum depth, it is completely buried inside the inner peripheral surface of the recess. This pushing member 1r
Is urged downward by the compression spring 1s, and thus plays a role of separating the first molded product W1 from the recess 1d of the first die 1b after pressing.

The first punch 1f has a cylindrical shape, and its head is formed in a substantially hemispherical shape. The shape of the head of the first punch 1f matches the shape of the recess 1d of the first die body 1c. The shape of the head of the first punch 1f and the shape of the recess 1d of the first die body 1c that matches the shape of the head.
By adjusting the depth, the shape and height of the first molded product W1 can be adjusted, and it is possible to manufacture a joint having a required shape and size.

Around the first punch 1f, a spring 1 is provided downward.
An inner pressing die 1h having a hollow cylindrical shape, which is equipped with i and is vertically movable, is provided so as to wrap the peripheral side surface of the first punch 1f. Since the inner presser die 1h is attached so as to be movable up and down, wrinkles are prevented from occurring in the molded product during pressing. In addition to the spring, a cushioning material such as a pressure device including a cylinder and a piston may be used.

A hollow cylindrical outer pressing die 1g is fixed around the inner pressing die 1h so as to enclose the peripheral side surface thereof. The height of the outer pressing die 1g is the same as the height of the inner pressing die 1h, and is set to a position slightly higher than the height of the tip of the first punch 1f. A cutting edge 1k is provided along the inner periphery of the upper end of the inner peripheral surface of the outer pressing die 1g. In addition, by preventing the top surface of the outer pressing die 1g from coming into contact with the lower surface of the die extending portion 1e and pressing more than necessary during the press working, the first molded product W1 having a constant shape is always formed. It can be molded.

In this step, first, the working plate 1a is placed on the outer presser die 1g and the inner presser die 1h so as to completely cover the inner side of the outer presser die 1g in the radial direction. And the first
Press with die 1b. Then, first, the cutting edge 1j provided on the lower end of the outer peripheral surface of the first die body 1c and the cutting edge 1k provided on the upper end of the inner peripheral surface of the outer pressing die 1g cooperate with each other to form the outer edge of the work plate 1a. The work plate 1a is cut and the work clamp 1g
It is cut into a circle that fits the inner circumference of the. After that, the circularly cut processing plate 1a sandwiched between the lower surface of the first die body 1c and the top surface of the inner pressing die 1h is pressed downward to form the head shape of the first punch 1f. To be done.

By the above-mentioned present step, a bowl-shaped first molded product W1 as shown in FIG. 1B is molded.

FIG. 2A shows a step of forming a ring-shaped groove in the head of the first molded product W1 by press working, and FIG. 2B shows a second molded product molded thereby. W
It is a figure showing 2.

In FIG. 2A, 2a is a second punch, 2b is a second punch main body, 2c is a ring-shaped projection,
2d is a concave portion, 2e is a second die plate, 2f is a second die, 2g is a ring groove of the second die, 2i is a second shank, 2j is a second upper die holder, 2k is a second punch plate, and 2m. Indicates the second pedestal.

In this step, the second punch 2a is installed above and the second die 2f is installed below the same coaxially.
The second punch 2a has a substantially columnar second punch main body 2b, and a ring-shaped protrusion 2c having a substantially V-shaped cross section at the center of the lower surface of the second punch main body 2b, and its ring. A recess 2d is provided on the inner side of the protrusion 2c. The center of the ring-shaped protrusion 2c is
It is set coaxially with the center of f. In addition, the concave portion 2d of the second punch main body portion 2b prevents the first molded product W1 from being deformed by coming into contact with the first molded product W1 put on the head of the second die 2f during pressing. It is provided.

The second die 2f has a columnar shape and its head has a substantially hemispherical shape. The head of the second die 2f is provided with a ring-shaped groove 2g having a suitable shape at a position corresponding to the ring-shaped protrusion 2c of the second punch 2a.

In this step, the first molded product W1 is transferred to the second die 2
It is put on f and pressed by the second punch 2a. Then, the second
The ring-shaped protrusion 2c on the lower surface of the punch body 2b presses the head of the first molded product W1, the ring-shaped groove 2h is formed in the head of the first molded product W1, and the surplus is the ring of the second die 2f. It is extruded into the groove 2g.

In this embodiment, the depth of the ring-shaped groove 2h formed in the second molded product W2 is set to about 2 mm. However, by providing a groove deeper than this, it is a finished product. It is possible to further angle the retainer formed on the.

Through this step, as shown in FIG.
A second molded product W2 having a ring-shaped groove 2h provided on the head of the first molded product W1 is molded.

FIG. 3A is a view showing a step of forming a through hole inside the ring-shaped groove 2h provided in the second molded product W2 by punching, and FIG. 3B is formed by it. It is a figure showing the 3rd molded product W3.

In FIG. 3A, 3a is the third punch, and 3 is
b is a cushion material, 3c is a third die plate, 3d is a third die, 3e is a cylindrical hole of the third die, 3g is a third shank, 3h is a third upper die holder, 3i third punch plate, 3j. Indicates the third pedestal.

In this step, the third punch 3a is installed on the upper side and the third die 3d is installed on the lower side coaxially. Third
The punch 3a has a cylindrical shape, and its third punch 3
A cushion material 3b having a hollow cylindrical shape and having elasticity in the vertical direction is provided so as to surround the peripheral side surface of a. The cushion material 3b is made of an elastic material such as urethane or rubber, and plays a role of pressing and fixing the second molded product W2, which is covered by the third die 3d during pressing, on the third die 3d. Thereby, the through hole can be opened at an accurate position.

The shape of the third die 3d is a columnar shape having a substantially hemispherical head. The shape of the head of the third die 3d matches the shape of the inner peripheral surface of the second molded product W2. Further, a cylindrical hole 3e is vertically provided at the center of the third die 3d. This hole 3e conforms to the shape of the third punch 3a, and is provided so that the third punch 3a can be accommodated when pressed.

In this step, the second die W is formed on the third die 3d.
2 is installed, and a circular through hole 3f is opened in the second molded product W2 by the third punch 3a. Since the through hole 3f has the cylindrical hole 3e of the third die 3d provided concentrically with the third die 3d, the ring-shaped groove 2h of the second molded product W2 is formed.
Become concentric with.

In this embodiment, the diameter of the ring-shaped groove 2h provided in the third molded product W3 is about 22 mm, and the diameter of the through hole 3f is about 14 mm. The portion between the through hole 3f and the ring-shaped groove 2h is finally the joint Z of the finished product.
It becomes 5k in the coming off. In addition, by changing the diameter of the ring-shaped groove 2h and the diameter 3f of the through hole formed in the third molded product, the scale of the joint Z, which is a completed product, and the retainer 5 can be appropriately prepared.
It is possible to change the dimension of k.

By this step, a third molded product W3 having a through hole 3f formed at the center of the second molded product W2 as shown in FIG. 3B is molded.

FIG. 4A is a diagram showing a step of forming the third molded product W3 by burring to draw it from the inside and form it into a cylindrical shape, and FIG. 4B shows the fourth molded product formed by this. It is a figure showing goods W4.

In FIG. 4A, 4a is a fourth die and 4b.
Is a fourth upper die holder, 4c is a knockout rod, 4d is a nut, 4e is a fourth die plate, 4f is a fourth punch,
4g is a fitting portion at the top of the 4th die, 4h is a presser type, 4m is a cushion pin, 4n is a lower die holder, 4p is a column, 4r.
Is a cushion pad, 4s is a pressure device such as a spring or an air cushion, and 4t is a fourth pedestal.

In this step, the fourth die 4a is installed on the upper side and the fourth punch 4f is installed on the lower side coaxially therewith. Fourth
The die 4a has a cylindrical shape that opens downward, and the lower end of the inner peripheral surface of the fourth die 4a has a third shape when pressed.
It is provided so as to contact the side surface of the molded product W3. The depth inside the fourth die 4a is set deeper than the height of the molded fourth product W4.

Inside the fourth die 4a, a knockout rod 4c is attached from the inside of the fourth die 4a through a through hole vertically provided in the fourth die plate 4e and the fourth upper die holder 4b. . This knockout rod 4c
Consists of a rod part having threaded ends and a circular plate-shaped part formed at the other end perpendicular to the rod part. Then, the nut 4d is fastened to the thread portion of the rod portion protruding from the fourth upper die holder 4b, and the knockout rod 4c
Is suspended with its circular plate-shaped portion being arranged in the fourth die 4a. This nut 4d is a knockout rod 4c
Are provided to prevent the falling of the knockout rod 4c, and the knockout rod 4c is kept movable up and down with respect to the fourth upper die holder 4b without being tightened to the limit.
The knockout rod 4c plays a role of separating the fourth molded product W4 molded in this step after pressing from the fourth die 4a.

The shape of the fourth punch 4f is a columnar shape in which the head is formed in a substantially hemispherical shape that conforms to the shape of the inner peripheral surface of the third molded product W3, and the center of the crown has a first A cylindrical fitting portion 4g having an outer diameter adapted to the shape of the through hole 3f of the three molded product W3 is provided. By this fitting portion 4g, the third molded product W3 is fixed to the fourth punch 4f when the fourth die 4a is pressed, and the third molded product W3 can be uniformly drawn and narrowed.

A hollow cylindrical pressing die 4h is provided on the outside of the peripheral side surface of the fourth punch 4f. This presser mold 4
Four cushion pins 4m are vertically attached to the lower surface of h. The other end of the cushion pin 4m penetrates through the four through holes provided in the lower mold holder 4n, and is vertically attached to the upper surface of the cushion pad 4r installed below the lower mold holder 4n. Further, a pressure device 4s such as a spring or an air cushion is attached to the lower surface of the cushion pad 4r, and is kept in a vertically movable state. That is, the cushion pad 4
r, the cushion pin 4m provided on the upper surface thereof, and the presser die 4h attached to the upper end portion of the cushion pin 4m are held in a vertically movable state.

In this step, first, the third molded product W3 is made into a fourth product.
Install on punch 4f. At this time, the third molded product W3 is placed and placed on the pressing die 4h. Then, by pressing the fourth die 4a, the lower end of the inner peripheral surface of the fourth die 4a comes into contact with the peripheral side surface of the third molded product W3, and the third die 4a is directly pressed.
By applying pressure downward to the molded product W3, the third molded product W3 is drawn and narrowed and molded into a cylindrical shape. In addition, the surplus of the third molded product W3 pushed down when the third molded product W3 is drawn and squeezed causes the lower surface of the fourth die 4a and the upper surface of the pressing mold 4h by the downward movement of the pressing die 4h. It moves downward while being sandwiched between and, and is pressed when the lower surface of the pressing die 4h comes into contact with the upper surface of the lower die holder 4n. As a result, a substantially circular brim portion 4i extending outward in the radial direction from the lower end of the cylindrical portion 4j of the fourth molded product W4 shown in FIG. 4B is formed.

By this step, as shown in FIG.
A fourth molded product W4 having a cylindrical joint cylindrical portion 4j and a substantially circular brim portion 4i extending outward in the radial direction is formed at the lower end portion thereof. The portion above the ring-shaped groove 2h provided in the joint cylindrical portion 4j becomes the folding margin portion 4k in the next step.

FIG. 5A is a view showing a step of bending the folding margin portion 4k of the fourth molded product W4 above the ring-shaped groove 2h by pressing into the ring-shaped groove 2h radially outward. (B) is a diagram showing the joint Z completed thereby.

In FIG. 5A, 5a is a fifth punch, 5b is a fifth die plate, 5c is a spring, and 5d is a fifth.
Die, 5e is a presser die, 5f is a cutting blade provided in the presser die,
5g is a 5th die extension part, 5h is an upper stage extension part of a 5th die extension part, 5i is a lower stage extension part of a 5th die extension part, 5j is a boundary of an upper stage extension part and a lower stage extension part Surface, 5n 5th shank, 5p
Indicates a fifth upper die holder, 5r indicates a fifth punch plate, and 5s indicates a fifth pedestal.

In this step, the fifth punch 5a is installed on the upper side and the fifth die 5d is installed under the fifth punch 5a on the same axis. The fifth punch 5a has a columnar shape, and a lower end portion thereof has a truncated cone shape whose diameter decreases as it goes downward, and a spring 5c is mounted on the fifth punch 5a as a cushioning material. The diameter of the circle on the lower surface of the fifth punch 5a is set smaller than the diameter of the opening of the fourth molded product W4. A hollow cylindrical pressing die 5e is provided outside the peripheral side surface of the fifth punch 5a, and a cutting blade 5f is provided at the lower end of the inner peripheral surface of the pressing die 5e.

The fifth die 5d has a columnar shape, and the outer periphery of the lower end portion thereof is provided with a fifth die extending portion 5g extending radially outwardly in a circular shape. This 5th die 5d
Has a diameter corresponding to the inner diameter of the fourth molded product W4. Further, the fifth die extension part 5g is composed of two stages of a circular upper extension part 5h and a lower extension part 5i, and a boundary surface 5j between the upper extension part 5h and the lower extension part 5i is formed vertically. ing. The diameter of the outer circumference of the upper extension 5h matches the diameter of the inner circumference of the presser die 5e, and when pressing, the inner peripheral surface of the presser die 5e, the upper extension 5h, and the lower extension 5i. It is set so that the boundary surface 5j of and contacts.

In this step, first, the fourth molded product W4 is placed on the fifth die 5d. At this time, the fourth molded product W4 is
It is placed on the upper stage extending portion 5h of the die extending portion 5g. When the fifth punch 5a presses, the fifth punch 5a bends the folding margin 4k above the ring-shaped groove 2h of the fourth molded product W4 outward, and then cuts the lower end of the inner peripheral surface of the pressing die 5e. The flange 5i of the fourth molded product W4 is cut into a clean circle by the blade 5f to form a flange 5m shown in (B) of FIG. As a result, the cutting process in finishing can be omitted, and the productivity can be improved and the cost can be reduced. In addition, the fifth die 5d fixes the fourth molded product W4 at the time of pressing, and the joint Z which is a finished product.
Since the crown portion of the fifth die 5d contacts the lower surface of the fifth punch 5a after forming the retainer 5k in Fig. 5, it is possible to prevent excessive pressing.
The retainer 5k of the joint Z, which is the finished product shown in (B), can be adjusted to an appropriate angle.

By this step, as shown in FIG.
The joint Z according to the present invention, which has the cylindrical portion 4j and is provided with the retainer 5k and the flange 5m at both ends thereof, is completed.

Incidentally, the ring-shaped groove 2 is formed on the fourth molded product W4.
When this step is performed using a molded product in which h is not formed, the bent portion as a folding margin is not constant, and the shape of the opening on the retaining side is similar to that of the joint Z according to the present invention. It does not have a nice circular shape but has a wavy shape. On the other hand, when trying to make the opening on the retaining side of the joint into a clean circular shape, it is very complicated because the pressure of the press has to be adjusted very precisely, and even if it can be molded into a clean circular shape, This time, it will not be possible to make a strong angle to prevent the joint from coming off.

On the other hand, in the present invention, by providing the ring-shaped groove 2h in the fourth molded product W4, high productivity is realized, the molding precision of the joint is enhanced, and the joint retaining function is enhanced. Has been realized. In this respect, the maximum effect of the present invention appears.

FIG. 6A is a sectional view of the folding margin portion 4k of the fourth molded product W4, and FIG. 6B is a ring-shaped groove 2 of the joint Z.
5C is a cross-sectional view of the retaining member 5k formed by h, and FIG. 5C shows a molded product in a state where the ring-shaped groove 2h is not formed in the fourth molded product W4 shown in FIG. 4B. FIG. 9 is a cross-sectional view of the retainer when the retainer is provided by performing the step shown in FIG.

The retainer shown in (C) is the fourth molded product W4.
Since the step in FIG. 5A is performed without providing the ring-shaped groove on the curved portion, the bent portion 6a has an arc shape and the retaining function does not sufficiently function.

The retainer 5k of the joint Z according to the present invention shown in (B) has a contact portion which comes into contact with the flexible pipe inside the joint, even though the ring-shaped groove 2h is provided to increase the angle. Since 6b is formed by press molding, it has a smooth arc shape. In other words, the retainer 5k of the joint Z according to the present invention has a significantly strengthened retainer function by increasing the angle, but the contact portion 6b that abuts the inner flexible pipe has an arc shape, so the flexible pipe is damaged. There is nothing to do.

In FIG. 7, the joint Z according to the present invention is attached to the flexible pipe cylindrical portion 7b, the flexible pipe 7a is covered with the net pipe 7c, and the ring-shaped fixing member 7d is passed over the net pipe 7c. It is a figure showing the state.

In this embodiment, the flexible tube 7a is made of stainless steel. The net tube 7c is mainly made of stainless steel or iron and serves to protect the flexible tube 7a. Since the net tube 7c has elasticity and is passed through the flexible tube 7a in an extended state, it is attached in close contact with the flexible tube 7a. The fixing member 7d is made of stainless steel in this embodiment.

In the present embodiment, the flexible tube cylindrical portion 7b
In addition, the retainer 5k of the joint Z has a flexible pipe bellows 7e.
After the joint Z is attached so as to be in contact with the end of the net, the net pipe 7c is covered. The end portion of the net pipe 7c completely covers the joint cylindrical portion 4j and is attached in a state of contacting the flange 5m of the joint Z. After that, the ring-shaped fixing member 7
d is passed from above the net pipe 7c and installed in the joint cylindrical portion 4j.

FIG. 8A is a view showing a state in which the fitting Z of the present invention is completely attached to the flexible pipe 7a.
(B) is a diagram showing a cross section of the cylindrical portion 4j of the joint Z attached to the flexible pipe 7a taken along line XX.

In this embodiment, after the joint Z, the net pipe 7c and the fixing member 7d are installed in the flexible pipe 7a in the state shown in FIG. 7, the flexible pipe 7a is opened from the opening 7f to the inner peripheral surface of the flexible pipe cylindrical portion 7b. After inserting an iron mandrel of a suitable shape, the ring-shaped fixing member 7d is caulked at six positions at equal intervals in the circumferential direction of the joint cylindrical portion 4j. Then, the fixing member 7d, the net pipe 7c, and the joint cylindrical portion 4j are 6
Although it is recessed to the inner peripheral surface side of the joint Z at some point, the flexible pipe 7a
Since the mandrel is caulked with the mandrel inserted therein, the inner peripheral surface of the flexible tube cylindrical portion 7b is not deformed with its original cylindrical shape. Also, these six recesses 8c, 8
The shapes of c, ... Are substantially rectangular with sides that match the length of the joint cylindrical portion 4j in the longitudinal direction. As a result, the retainer 5k works effectively, and the fixing member 7d and the net tube 7c
Will never come out. That is, by caulking the fixing member 7d at 6 points, the fixing member 7d, the net pipe 7c, and the joint cylindrical portion 4j are firmly fixed by being recessed toward the inner surface of the joint Z at 6 points, and the joint Z is Flexible tube 7
It is securely fastened to a.

Therefore, according to the present invention, the fixing member 7d and the net pipe 7c are welded in the joint cylindrical portion 4j as in the conventional case, and the inner peripheral surface of the joint Z and the outer peripheral surface of the flexible pipe cylindrical portion 7b are welded together. Since there is no need to join at, the cause of rust can be completely removed.

Thereafter, the flexible pipe cylindrical portion 7b protruding from the joint Z is expanded into the lantern shape from the inner side to the outer side using hydraulic pressure, and the tip of the flange 5m of the joint Z is directed toward the tip of the flange 5m of the joint Z. Crushed to be flush with the surface. After that, the remaining portion of the cylindrical portion 7b is cut off at the tip of the flange 5m of the joint Z. This completes the work of fixing the joint Z.

[0062]

As described above in detail, according to the inventions described in claims 1 and 2, it is possible to realize the high productivity and the low cost of the production of the flexible pipe joint, and to improve the molding accuracy. High molding can be performed. Further, according to the invention described in claim 3, it is possible to completely eliminate the conventional welding that has caused rust, and eliminate the cause of rust mixing in tap water.

[Brief description of drawings]

FIG. 1 (A) is a diagram showing a first step of a method for manufacturing a flexible pipe joint according to the present invention, and FIG. 1 (B) is a diagram showing a molded product molded by the method.

FIG. 2 (A) is a diagram showing a second step of the method for manufacturing a flexible pipe joint according to the present invention, and FIG. 2 (B) is a diagram showing a molded article molded by the method.

FIG. 3 (A) is a view showing a third step of the method for manufacturing a flexible pipe joint according to the present invention, and FIG. 3 (B) is a view showing a molded product molded by the method.

FIG. 4 (A) is a diagram showing a fourth step of the method for manufacturing a flexible pipe joint according to the present invention, and FIG. 4 (B) is a diagram showing a molded product molded by the process.

FIG. 5 (A) is a diagram showing a final step of the method for manufacturing a flexible pipe joint according to the present invention, and FIG. 5 (B) is a diagram showing a joint as a finished product manufactured thereby.

FIG. 6A is a cross-sectional view of a fold margin of a molded product,
(B) is a cross-sectional view of the retainer of the finished product,
FIG. 5C shows a molded product in which no ring-shaped groove is formed.
FIG. 6 is a cross-sectional view of a retaining member when molding is performed by performing the step shown in FIG.

FIG. 7 is a view showing a state in which a joint manufactured by the method according to the present invention, a net tube, and a ring-shaped fixing member are arranged on a flexible tube.

FIG. 8A is a diagram showing a state in which a joint manufactured by the method according to the present invention is fixed to a flexible pipe,
(B) is a cross-sectional view showing a state of the main body of the joint taken along line XX.

[Explanation of symbols]

2h ring groove 3f Through hole inside ring groove 7a flexible tube 7b Cylindrical part of flexible pipe 7e Flexible pipe bellows Z joint 4j Joint cylindrical part 5m flange 5k retaining

Claims (3)

[Claims] 1. A method for manufacturing a flexible pipe joint, wherein a thick steel plate is press-formed into a bowl shape, a ring-shaped groove is provided on the outer surface of the head of the molded product, and a through hole is formed inside the ring-shaped groove. Is formed, and the molded product is drawn out and squeezed to form a tubular shape, and then the upper end of the side wall of the molded product is bent outward at the ring-shaped groove portion. 2. A flexible pipe having a wavy uneven cross section is externally fitted to a cylindrical portion formed at an end of the flexible pipe, a flange is formed at one end, and a retainer protruding outward in the radial direction is formed at the other end. In the method for manufacturing a flexible pipe joint as described above, a tubular part having a ring-shaped groove formed along the outer peripheral surface is bent outward with the upper part of the ring-shaped groove as a folding margin to bend the part. A method for manufacturing a flexible pipe joint, characterized in that a stop is formed. 3. A method for fixing a joint to a flexible pipe having an uneven cross-section and having a cylindrical end portion, which comprises a cylindrical body portion, a flange at one end, and a retaining member at the other end. After fitting the formed joint to the cylindrical portion of the flexible pipe, by applying pressure at multiple locations that are circumferentially spaced from the outer peripheral surface of the joint main body toward the inner side, by indenting the joint,
A method for fixing a joint to a flexible pipe, characterized in that a cylindrical portion of the flexible pipe is engaged with a joint body.