KR100683404B1 - Method, apparatus for forming cutting ends of a flexible tube, and the flexible tube produced by the same - Google Patents

Abstract

A method and an apparatus for forming cutting ends of a flexible tube, and a flexible tube produced by the same are provided to easily perform the brazing of a joint, by compressing both side surfaces of the flexible tube. A method comprises a first step of forming a straight pipe portion(11a) by compressing cutting ends of a fundamental flexible tube(11) into a predetermined length at the state where a curved portion of the fundamental flexible tube is held; a second step of applying a brazing solvent(40) to an end and an outer surface of the straight pipe portion and a part of the curved portion arranged in the vicinity of the straight pipe portion; a third step of fitting a front end of a ripple(20) to the portion where the brazing solvent is applied; and a fourth step of applying the brazing solvent to the other end of the ripple, and fitting a cylindrical member(30) to the ripple so that the fundamental flexible tube and a protective mesh(12) are brazed to the nipple during heat treatment.

Description

Method for forming flexible tube cutting part and apparatus therefor and flexible tube manufactured by the same {Method, apparatus for forming cutting ends of a flexible tube, and the flexible tube produced by the same}

1A and 1B are exploded perspective and assembly cross-sectional views of a flexible tube according to the prior art for connecting a joint with a braided helical flexible tube by means of a welder;

2A is a cross-sectional view for explaining a method of forming a cut portion of a flexible tube for mounting a joint by forming a stainless steel cylindrical tube by a continuous die forming method and then cutting it to a predetermined length and forming both ends flat by a swaging method. ;

2B is a cross-sectional view illustrating a method of forming a cut portion of a flexible tube for mounting a joint by cutting a straight tube portion and a helical corrugation portion simultaneously by forming a stainless steel cylindrical tube by a continuous die forming method;

3 is an exploded perspective view illustrating a process of assembling a helical flexible tube having a cross section molded according to the present invention;

4 is a cross-sectional view of the joint attached to the flexible tube shown in FIG.

5a to 5d are views sequentially illustrating a method of forming a cut portion of a helical flexible tube according to the present invention;

6 is an exploded perspective view showing a process of assembling an annular flexible tube shaped cross section according to the present invention;

FIG. 7 is a sectional view of a state in which a joint is attached to the flexible tube shown in FIG. 6; FIG.

8a to 8d sequentially show a method of forming a cut portion of a ring-shaped flexible tube according to the present invention;

9 is a side view of an apparatus for compression molding a cut of the flexible tube of the present invention;

10 is an exploded perspective view of a die for compression molding a cut of a helical flexible tube;

11 to 16 are side views sequentially showing a process of compression molding the cut portion of the spiral flexible tube;

17 is an exploded perspective view of a die for compression molding a cut of a ring-shaped flexible tube;

It is a side view which shows the process of compression-molding the cut | disconnected part of a ring-shaped flexible tube.

Explanation of symbols on the main parts of the drawings

10, 100: flexible tube 11, 111: basic flexible tube

11a and 111a: straight pipe portion 20: straight pipe portion

30: cylinder 40: brazing solvent

200: cutting unit forming apparatus 210, 230: cylinder

220, 320: Gripping strip 221,321: Gripping groove

222: outer guider 230: cylinder

231: crimp 231a: inner guider

231b: compression plate 232: guide guider

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of manufacturing flexible tubes made of metal. When brazing a joint including various nuts and nipples to a helical or annular flexible tube, the both sides of the flexible tube are compressed to a predetermined length to braze the joint. An apparatus for forming a cut part of a flexible tube to facilitate connection and a flexible tube manufactured thereby.

Metallic flexible tubes are metal tubes with bellows-shaped tube walls, which can be stretched / contracted, bent and bent, so that these tubes are for example moving tubes, sprinklers, gas piping, automotive piping, steel, petroleum refining, industrial equipment and equipment, It is widely used for the purpose of absorbing displacement, such as thermal expansion / contraction, in plant piping in petrochemical, power generation, and other industries.

For example, there is a continuous die forming method for manufacturing a metal flexible tube, which passes through a corrugated forming die mounted on a die holder with a cylindrical metal, preferably an austenitic stainless steel tube, with a bearing interposed therebetween. Eccentrically supports the center of the tube and the center of the die, and while forming the circumferential groove continuously by pushing the protrusion of the die into the metal tube while rotating the corrugated forming die around the center of the tube to form a bellows-shaped tube wall. In addition, annealing is performed at about 1030 to 1150 ° C. to perform a heat treatment process to remove the residual stress in the flexible tube. A process of mounting a joint to the flexible tube thus manufactured is schematically described with reference to FIGS. 1A and 1B. Explain.

As shown in FIG. 1A, the outer side of the spiral (helical) flexible tube 1 is covered with a guard net 2 made of stainless steel wire, and the ends thereof are fitted in the cylindrical tube 3 and at the same time the inside of the nut 4. After inserting the cylindrical body 5 with the locking portion 5a formed therein, the other end of the cylindrical body 5 is inserted into the inside of the flexible tube 1 to some extent and welded to the site W using a welder. It was.

However, when the end of the cylindrical tubular body 3 is welded using a welder, the fluid flowing inside, especially when used as a sprinkler flexible tube, inserts into the inside of the flexible tube 2 is rusted. There was a problem that is the main cause of environmental pollution due to the generation of dust.

The basic reason why the cylindrical tube 5 should be inserted into the spiral flexible tube 2 as shown in FIG. 1B is that the spiral flexible tube 2 has a low resistance during fluid transfer, a good ability to absorb distortion, and is very easy to bend. This is because crimping of the end is impossible because the wrinkles are formed in a spiral shape.

Various techniques have been proposed to solve such a problem. For example, Korean Patent No.0406715 discloses a technique for brazing a flexible tube and a protective net to prevent the occurrence of rust as described above.

However, the above patent only proposed a method of simply joining the straight pipe portion and the guard net of the helical flexible tube by brazing welding, and did not mention the treatment of both ends of the flexible tube which is easy to braze the joint. The spiral flexible tube used will be described with reference to FIGS. 2 and 2B.

The spiral flexible tube 1 shown in FIG. 2A is continuously manufactured by the above-described continuous die forming method. For example, for use as a sprinkler, the cutting line C is cut by using a suitable tool and swissed at both ends thereof. Forming a straight pipe portion 1a having an outer diameter d smaller than the outer diameter D of the original bent portion by the SWAGING method, and then applying a protection net as in the aforementioned patent, and then joining nipples or reducers by brazing welding. It is to be made.

However, as shown in Fig. 2a, when the end of the spiral corrugated pipe 1 is straightened by swaging, the straight pipe portion 1a is formed, and then the brazing cost of the spiral corrugated pipe 1M is almost the same as the cost of producing the spiral corrugated pipe 1M. Therefore, there was a problem that the manufacturing cost is increased.

On the other hand, Figure 2b, unlike Figure 2a shows a spiral flexible tube formed by alternately forming the bent portion and the straight pipe portion 1b of a predetermined length during continuous die molding, which is a continuous tube tube having the bent portion and the straight pipe portion (1b) A plurality of flexible tubes 1 ', 2' ', 3' '' having a straight portion 1a similar to that shown in FIG. 2A by cutting the central portion C of the straight portion 1b in the course of production To prepare.

However, since the length of the straight pipe portion 1b is not precisely formed by the required length during continuous die molding, the lengths of the straight pipe portion 1b are different from each other. Therefore, after the first cut along the cutting line c, Since the second straight cut can obtain the desired straight pipe portion, unnecessary material loss occurs due to the second cut. Also, in the case of the basic flexible tube of 20 A or less, the straight pipe portion can be automatically cut by the continuous die forming method. Can't. In addition, in FIG. 2B, the outer diameter D of the bent portion and the outer diameter d of the straight pipe portion 1b are the same in the characteristics of the continuous die forming apparatus, and the flexible tube shown in FIG. 2B is connected to the flexible tube shown in FIG. 2A. Compared with the mountain and valley limitations, flexural strength (bending strength) had a big problem.

In addition, since the length of the flexible tube shown in FIG. 2B is limited to the purpose, there is an inconvenience in that the die of the molding apparatus must be set in order to have an arbitrary length. Since there is a possibility of leakage, the corresponding flexible tube has to be disposed, there is a problem such as loss of material.

The present invention has been invented to solve the above problems, the main object of the present invention is to cut the flexible tube produced by the continuous die molding method as necessary to fit the purpose by pressing both sides of the flexible tube to a predetermined length straight pipe By forming the part, it is not only easy to work but also provides a flexible tube which can lower the manufacturing cost.

 It is another object of the present invention to provide a method for forming a cut portion of a flexible tube in which a bone and an acid are deeply formed to form a cut portion of the flexible tube having a good flexural force and a substantially flat straight tube portion.

Still another object of the present invention is to provide an apparatus for forming a cutout portion of a flexible tube, which is capable of compressing both sides of the flexible tube to a predetermined length to facilitate a brazing connection of the joint.

According to an embodiment of the present invention for achieving the above object, there is provided a method for forming a cut portion of a flexible tube, which is produced by a continuous die forming method and a steel wire on a metal basic flexible tube having a predetermined acid and valleys. In brazing a joint to a basic flexible tube having a protective net woven in the form of: A crimping part of the basic flexible tube is pressed from the end by a predetermined length in a state of holding the bent portion of the basic flexible tube so that the peaks and valleys closely adhere to each other. A first step of forming a substantially flat straight tube portion; A second step of applying a brazing solvent to an end portion and an outer circumference of the straight tube portion in which the acid and the bone formed in the first step are tightly compressed and a portion of the bent portion adjacent to the straight tube portion; A third step of inserting a tip of the ripple into a portion to which the brazing solvent is applied in the second step; And a fourth step of applying a brazing solvent to the other end of the ripple to insert a cylindrical body with a nut to weld the basic flexible tube and the guard net to the nipple during heat treatment.

The present invention is also applicable to both helical or annular flexible tubes.

According to another embodiment of the present invention, there is disclosed an apparatus for forming a cut portion of a flexible tube, which is formed by a continuous die forming method and has a foundation having a protective net woven from a steel wire on a metal-based flexible tube having a predetermined acid and valley. An apparatus for forming a cut portion of a flexible tube, the apparatus comprising: a gripping groove having the same shape as a curved portion of the basic flexible tube, and gripping the basic flexible tube when the outer flexible portion of the basic flexible tube is gripped to press the cut portion of the basic flexible tube. A pair of grippers for preventing the; An outer guider attached to one end of the gripper for guiding the outer circumference of the basic flexible tube when the cut portion of the basic flexible tube is crimped; And an inner guider mounted to a cylinder to be inserted into an inner diameter of the cut portion of the basic flexible tube to guide the inside thereof when the cut portion of the basic flexible tube is crimped, and the gripper holding the bent portion of the basic flexible tube. A crimping plate including a crimping plate for squeezing the cut end of the flexible tube by a predetermined length to form a substantially flat straight tube by closely contacting the mountain and the valley, and a crimping hole including a guide guider for guiding the inner guider and the crimping plate. The ship is characterized by technical construction.

The diameter of the outer guider used in the present invention has an inner diameter larger than the outer diameter of the basic flexible tube, and preferably has a depth substantially equal to the length of the compressed straight tube portion of the flexible tube.

The gripper is preferably replaceable according to the type and size of the basic flexible tube. Therefore, the present invention can be applied to both a helical or annular flexible tube.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 and 4 are exploded perspective views and assembling cross-sectional views showing the assembling process of the helical flexible tube formed in the cross section according to the present invention, respectively, the basic flexible tube 11 used in the present invention is a continuous continuous It is produced by the die molding method.

The basic flexible tube 11 is preferably a spiral basic tube deeply formed with a peak and a valley, as shown in FIG. 2A, because the basic flexible tube having good bendability is manufactured as shown in FIG. It is to make it easy for an operator to bend by cutting and mounting a joint by crimping | cutting both ends.

Again, in Fig. 5A, any part of the base flexible tube 11 manufactured by the continuous die forming method is cut to the required length with a suitable tool, and then the cut portion of the base flexible tube 11 is cut off as shown in Fig. 5B. And the hills and valleys are pressed to each other by a predetermined length to form a substantially flat straight pipe portion 11a.

When the straight pipe portion 11a is formed, a protective net 12 woven with steel wire is placed on the basic flexible tube 11 as shown in FIG. 5C, but a part of the bent portion adjacent to the straight pipe portion 11a of the basic flexible tube 11 is formed. The brazing solvent 40 is apply | coated to it.

Meanwhile, as shown in FIG. 5D, the brazing solvent 40 is also applied to the inside of the ripple 20, which is a joint brazed to the basic flexible tube 11, and also to a portion where one side of the cylindrical tube 30 is connected. After applying the brazing solvent 40, combine them, put them in a suitable furnace (for example, bright annealing furnace) and heated to a suitable temperature (1030 ℃ ~ 1150 ℃) as shown in Figure 4, the protection net 12 and the ripple 20, The basic flexible tube 11 is welded and the cylindrical body 30 is also welded to the ripple 20 to produce a flexible tube 10 having a very beautiful appearance.

6 to 8D show views similar to those shown in FIGS. 3 to 5D, which form a straight portion 111a of an annular flexible tube 100, the fabrication method being helical. Since the same as that of the flexible tube 10, detailed description thereof is omitted.

9 and 10 show a side view of a cutting unit forming apparatus 200 for compressing the cutting unit of the spiral flexible tube 10, the cutting unit forming apparatus 200 is raised and lowered cylinder 210, par Earth 220 and horizontally moving cylinder 230.

The gripper 220 is preferably divided into two parts to prevent the base flexible tube 11 from being pushed when the end of the basic flexible tube 11 is crimped, and the gripper 220 is a bent portion of the basic flexible tube 11. A spiral gripping groove 221 having the same shape as that of the base flexible tube 11 is firmly gripped when the cutting portion of the basic flexible tube 11 so that the base flexible tube 11 is not pushed out, the gripper 220 is It is desirable to be able to replace and use according to the type and size of the basic flexible tube.

On the other hand, the outer guider 222 is attached to one end of the gripper 220, the outer guider 222 guides the outer periphery of the basic flexible tube 11 during the end compression of the basic flexible tube 11 As described later, the diameter thereof has a larger inner diameter than the outer diameter of the basic flexible tube 11 and has a depth substantially equal to the length of the compressed straight pipe portion 11a of the basic flexible tube 11. desirable.

In addition, a pressing hole 231 is installed in the cylinder 230, and the pressing hole 231 can be inserted into the inner diameter of the basic flexible tube 11 to guide the inside of the basic flexible tube 11 when the end portion is crimped. The inner guider 231a and the gripper 221 grip the ends of the flexible tube 11 by a predetermined length in a state where the gripper 221 grips the bent portion of the basic flexible tube 11. A compression plate 231b for forming a substantially flat straight pipe portion 11a, and a guide guider 232 for guiding the inner guider 231a and the compression plate 231b.

The cutting part shaping | molding method of the basic flexible tube 11 provided with the straight pipe | tube part 11a using the cut part shaping | molding apparatus comprised in this way is demonstrated.

As shown in FIG. 11, after the upper portion of the gripper 220 is sufficiently opened using the cylinder 211, the basic flexible tube 11 manufactured by the continuous die forming method is introduced as shown in FIG. 12. 13, the cylinder 211 is operated to firmly grip the bent portion of the basic flexible tube 11.

Then, the cylinder 230 is operated in the direction of the arrow as shown in FIG. 14. In this case, the inner guider 231a of the pressing hole 231 is inserted into the inner diameter of the basic flexible tube 11 and the pressing plate 231b. Is in contact with the cut end of the basic flexible tube 11 to compress it.

This pressing operation is completed until it becomes as shown in FIG. 15, and then ends by retracting the cylinder 230 as shown in FIG.

Therefore, as shown in FIG. 16, the end portion of the basic flexible tube 11 is pressurized in the longitudinal direction to form a straight pipe portion 11a by compression molding until the gap between each acid is substantially eliminated. The term "intuition" in the present invention refers to compressing until an adjacent wall forming a valley with a hill is brought into surface contact, preferably until its front face is in surface contact, thereby forming a substantially flat portion. The straight pipe portion 1a obtained by the swaging method as shown in 2a and the straight pipe portion 1a set in advance by the continuous dice forming method as shown in FIG. 2b are clearly distinguished.

17 and 18 show the gripper 320 for compression molding the cut portion of the ring-shaped basic flexible tube 111 and the cut portion forming apparatus of the basic flexible tube 111 using the same, which is the embodiment described above. Since the same applies to the detailed description thereof will be omitted.

As described above, the present invention cuts the flexible tube manufactured by the continuous die forming method to the required length and compresses both sides of the flexible tube to a predetermined length to form a straight pipe, thereby making the brazing operation very easy, and the manufacturing cost. It is a very useful invention that can lower.

Although the present invention has been described with reference to the accompanying drawings, the present invention is not limited thereto, but many variations and modifications may be made within the scope of the following claims.

For example, the gripper can be replaced with a suitable size in consideration of the type and size of the basic flexible tube, and can be made to order according to the use of the joint.

Claims (8)

In brazing a joint to a foundation flexible tube with a protective net woven by steel wire over a metal foundation flexible tube made by a continuous die forming method with a predetermined acid and valley: A first step of pressing the cutout portion of the basic flexible tube by a predetermined length from an end in a state in which the curved portion of the basic flexible tube is gripped to form a substantially flat straight tube by closely contacting the peaks and valleys; A second step of applying a brazing solvent to an end portion and an outer circumference of the straight tube portion in which the acid and the bone formed in the first step are tightly compressed and a portion of the bent portion adjacent to the straight tube portion; A third step of inserting a tip of the ripple into a portion to which the brazing solvent is applied in the second step; And a fourth step of applying a brazing solvent to the other end of the ripple to insert a cylindrical body with a nut to weld the basic flexible tube and the guard net to the nipple during heat treatment. Way. 2. The method of claim 1, wherein the basic flexible tube is one of a helical or annular flexible tube. In the apparatus for forming a cut portion of a basic flexible tube manufactured by a continuous die forming method and provided with a protective net woven with steel wire on a metallic basic flexible tube having a predetermined acid and valley: A pair of gripping grooves having a gripping groove having the same shape as the bent portion of the basic flexible tube, and gripping an outer bent portion of the basic flexible tube to prevent pushing of the basic flexible tube when the end of the basic flexible tube is crimped. Wow; An outer guider attached to one end of the gripper for guiding the outer periphery of the basic flexible tube when the end of the basic flexible tube is crimped; And An inner guider mounted on a cylinder and inserted into an inner diameter of the basic flexible tube to guide the inside of the basic flexible tube when the end portion is crimped, and the gripper grips the bent portion of the basic flexible tube And a crimping plate including a crimping plate for squeezing an end portion of the end portion by a predetermined length so that the mountain and the valley are closely contacted to form a substantially flat straight pipe, and a guide guider for guiding the inner guider and the crimping plate. Cutting part forming apparatus of a flexible tube. The apparatus of claim 3, wherein the outer guider has an inner diameter larger than an outer diameter of the basic flexible tube, and has a depth substantially the same as that of the compressed straight tube of the flexible tube. . 4. The apparatus of claim 3, wherein the basic flexible tube is one of a helical or annular flexible tube. The apparatus of claim 3, wherein the gripper is replaceable according to the type and size of the basic flexible tube. A helical flexible tube having a straight tube portion in which an acid and a bone are tightly compressed by the cut portion forming apparatus according to claim 3. An annular flexible tube provided with a straight pipe portion in which an acid and a bone are tightly pressed by the cut portion forming apparatus according to claim 3.

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