JP2006159206A - Method and apparatus for working diametrically enlarged portion of pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for working a diametrically enlarged portion of a pipe by which the diametrically enlarged portion can be worked only by applying stress to the pipe from one end part, the reduction of the cost of equipment is possible by miniaturizing and simplifying the working apparatus and the diametrically enlarged portion in a position near the end part of the pipe and of a pipe bent beforehand is worked. <P>SOLUTION: By adding axial stress to the pipe 1 which is fast held with a clamp die 11 having a space for forming the diametrically enlarged portion from one end part with a punch die 13, applying fluid pressure to a position facing the space 27 for forming the diametrically enlarged portion of the pipe 1 from the inside through an injection port 29 of a liquid injecting shaft 12 provided on the punch die 13 and stretching a buckled part with the fluid pressure at the same time as a portion of the pipe 1 is buckled in the space 27 for forming the diametrically enlarged portion by the axial stress, the diametrically enlarged portion 1a which is suited to the shape of the space 27 for forming the diametrically enlarged portion is formed on the pipe 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pipe diameter-expanded portion processing method for processing an annular diameter-expanded portion in the middle of a pipe by applying hydraulic pressure and axial force, and a diameter-expanded portion processing apparatus used for carrying out this method.

  For example, in a metal pipe made of copper or aluminum used for a water supply, a hot water terminal, etc., in order to connect the pipes to each other or a passage of the base body, an enlarged diameter part bulging in the radial direction is integrally formed at the end part, etc. Using this enlarged diameter portion, a watertight means such as an O-ring is attached and connected to the pipe.

  Conventionally, a hydraulic basil molding method is known as a method for integrally molding a diameter-expanded portion that swells in the radial direction in the middle of a pipe. This hydraulic basil molding is illustrated in FIGS. 5 (a) and 5 (b). As shown in the schematic diagram, both ends of the pipe 1 are clamped with clamp molds 2 and 2 that can move toward and away from each other, and an expanded diameter securing mold 3 is disposed between the clamp molds 2 and 2, Using the processing device in which the punch dies 4 and 4 are arranged on the opposite sides of the clamp dies 2 and 2, both ends of the pipe 1 are held by the clamp dies 2 and 2 as shown in FIG. Both the punch dies 4 and 4 are brought close to the clamp dies 2 and 2, and both the punch dies 4 and 4 are both clamped with the liquid injection shaft 5 provided in the punch dies 4 and 4 being inserted into the end portion of the pipe 1. By pressing the molds 2 and 2 close to each other, axial stress is applied to the pipe 1 from both ends.

  The two clamp molds 2 and 2 that are close to each other are stopped by sandwiching the expanded diameter securing mold 3 disposed between them, so that the opposing surfaces of the clamp molds 2 and 2 and the inner peripheral surface of the expanded diameter securing mold 3 An annular molding space 6 is formed outside the pipe 1. As described above, the pipe 1 to which axial stress is applied from both ends is buckled toward the molding space 6 at a portion facing the molding space 6. Simultaneously with this buckling, the hydraulic pressure supplied from the outside of the punch dies 4 and 4 is discharged from the inlet 8 at the tip through the passage 7 of the liquid injection shaft 5 to a portion facing the molding space 6 in the pipe 1. To do.

As shown in FIG. 5 (b), the buckled portion of the pipe 1 is expanded in the radial direction by the supply of the hydraulic pressure, and the expanded diameter portion 9 is formed by bulging into the shape of the molding space 6, After that, if the supply of the liquid is stopped, the pipes are clamped by the clamp dies 2 and 2, the clamp dies 2 and 2, and the punch dies 4 and 4 are separated from each other, and the pipe 1 is extracted from the expanded diameter securing die 3 Processing is completed (see, for example, Patent Document 1).
JP 2002-239645 A

  By the way, the conventional method for expanding a diameter portion by hydraulic basil molding as described above has to press the pipe from both ends in the axial direction to apply stress, so that the processing apparatus becomes large and the equipment cost increases. There is a problem, and it is particularly difficult to process long pipes.

  In addition, since it is necessary to clamp both ends of the pipe, it is difficult to process the enlarged diameter portion at a position close to the end of the pipe, and it is impossible to process the enlarged diameter portion of the pipe that has been bent in advance. There's a problem.

  Accordingly, an object of the present invention is to process a diameter-expanded portion by simply applying stress from one end to a pipe, thereby making it possible to simplify the size of the processing device and reduce equipment costs. Therefore, an object of the present invention is to provide a method and an apparatus for processing a diameter-expanded portion of a pipe capable of processing the diameter-expanded portion with respect to a position close to the end of the pipe or a pipe that has been previously bent.

  In order to solve the above-mentioned problems, the invention of the method of claim 1 is to hold a pipe with a clamp die having a space for forming an enlarged diameter portion, and apply axial stress to the pipe from one end with a punch die. At the same time, hydraulic pressure is applied from the inside to the position facing the enlarged-diameter part forming space of the pipe from the injection port of the liquid injection shaft provided in the punch die, and a part of the pipe is brought into the enlarged-diameter part forming space by axial stress At the same time as buckling, a configuration is adopted in which a diameter-expanded portion adapted to the shape of the diameter-expanded portion forming space is formed on the pipe by extending the buckled portion in the radial direction with hydraulic pressure.

  According to the invention of the device of claim 2, the clamp that holds the pipe and forms the expanded portion forming space defined on the outside of the pipe with the fixed mold when the movable mold that fits outside the pipe is pushed by a predetermined stroke. And a punch mold that includes a liquid injection shaft that is fitted from one end into a pipe held by the clamp mold, and pressurizes the pipe in the axial direction from one end while simultaneously pushing the movable mold. The liquid injection shaft is formed at a position corresponding to the enlarged diameter portion forming space when inserted into the pipe, and an injection port for discharging the hydraulic pressure supplied from the outside of the punch die into the pipe, and on both sides thereof A structure provided with a watertight means with the inner diameter of the pipe is adopted.

  According to the present invention, a diameter-enlarged portion can be machined by simply applying stress from one end of a punch die to a pipe held by a clamp die, thereby reducing the size of the machining apparatus. Therefore, the equipment cost can be reduced, and a diameter-enlarged portion can be easily processed even for a long pipe with a space-saving device.

  In addition, the diameter-expanded portion can be machined simply by applying stress from one end to the pipe, so there is a position close to the end of the pipe and a straight portion that can be clamped to the end. If it exists, the process of the enlarged diameter part with respect to the pipe bent beforehand is also attained.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  As shown in FIG. 1 and FIG. 2, the pipe diameter-expansion portion processing apparatus includes a clamp die 11 that holds the end of the pipe 1 in a horizontal state, and one end in the pipe 1 that is held by the clamp die 11. A liquid injection shaft 12 fitted from a part is provided, and the pipe 1 is formed by a combination with a punch die 13 that pressurizes the pipe 1 in the axial direction from one end.

  The clamp mold 11 has, for example, a vertically split structure, and the lower mold 14 is fixedly disposed on the base table, and the upper mold 15 is moved up and down by a clamp cylinder or the like directly above the lower mold 14 so that the lower mold The pipe 1 is held in a horizontal state so as to be attachable and detachable by semicircular groove clamp portions 16 and 16 provided at positions near the rear end of the upper die 15 and the upper die 15.

  The clamp mold 11 is formed with a recessed portion 17 at a position close to the tip on the opposed surfaces of the lower die 14 and the upper die 15, and a fixed die 18 and a tip side on the inner end side in the recessed portion 17. A movable mold 19 is incorporated in the.

  The fixed mold 18 and the movable mold 19 are divided into two vertically and symmetrically. The fixed mold 18 has a fitting groove 20 of the pipe 1 on the opposite surface, and is fixed to the lower mold 14 and the upper mold 15 respectively. A semi-cylindrical extension 21 is provided on the tip side.

  The movable mold 19 is accommodated in the recesses 17 of the lower mold 14 and the upper mold 15 so that the movable mold 19 is guided by the guides 22 so as to be movable in the axial direction. And the inner diameter side of the tip portion is a fitting portion 24 to the pipe 1.

  The movable die 19 is movable between a forward position where the front end abuts a stopper (not shown) fixed to the lower die 14 and the upper die 15 and a retreat position where the rear end face abuts the front surface of the fixed die 18. A spring 26 is provided between the movable mold 19 and the fixed mold 18 to return the movable mold 19 to the forward movement position.

  When the movable mold 19 is in the forward movement position, the distance H between the front end surface of the extension 21 of the fixed mold 18 and the front end surface of the fitting recess 23 in the movable mold 19 is the rear end surface of the movable mold 19 and the front surface of the fixed mold 18. In the state where the distance 19 is set to be longer than the distance h and the movable mold 19 is in the retracted position, the enlarged-diameter portion forming space 27 for the pipe 1 is formed on the inner periphery of the fitting recess 23 by the difference between the distances H and h. It has become.

  That is, the inner diameter of the fitting recess 23 corresponds to the outer diameter of the enlarged diameter portion 1a corresponding to the enlarged diameter portion 1a formed in the pipe 1, and when the movable die 19 is in the advanced position, the fixed die The distance H between the front end surface of the extension portion 21 of 18 and the front end surface of the fitting recess 23 of the movable die 19 is obtained by adding the width of the enlarged diameter portion 1 a to the distance h between the rear end surface of the movable die 19 and the front surface of the fixed die 18. By setting the dimensions, the enlarged diameter portion forming space 27 having a shape suitable for the enlarged diameter portion 1a to be formed in the pipe 1 is formed with the movable die 19 in the retracted position.

  The punch die 13 can be moved forward and backward on the base table by a cylinder at a position on the tip side of the clamp die 11 in a coaxial arrangement with the clamp die 11, and faces the clamp die 11 of the punch die 13. On the distal end side, a circular liquid injection shaft 12 is provided so as to be fitted from one end into the pipe 1 held by the clamp die 11.

  The punch mold 13 is provided with a connecting portion 28 for supplying a pressure liquid from the outside, and an inlet 29 formed in the middle of the liquid injection shaft 12 and the connecting portion 28 are connected by a passage 30. The hydraulic pressure is discharged into the pipe 1.

  The liquid injection shaft 12 has an outer diameter that just fits the inner diameter of the pipe 1 and a length that fits to a predetermined depth in the pipe 1, and the injection port 19 expands in an inserted state in the pipe 1. The liquid injection shaft 12 is provided with water-tight means 31 for connecting with the inner diameter of the pipe 1 by O-rings or the like at positions on both sides of the injection port 29. It is provided so that the pressure liquid does not leak.

  In the case of illustration, the pipe 1 which forms the enlarged diameter portion 1a shows an example in which the flare 1b is bent at one end as a terminal treatment. When the enlarged diameter portion 1a is processed, the pipe 1 is movable 19 Is set on the clamp die 11 so that the flare 1b comes into contact with the front end surface of the plate.

  Accordingly, the tip surface of the punch die 13 is provided with a recessed portion 32 for allowing the flare 1b to escape, and the bottom surface of the recessed portion 32 presses the pipe 1 in the axial direction via the flare 1b. It is a pushing surface that applies stress.

  In the drawing, the tip surface of the punch die 13 pushes the movable die 19 and at the same time the bottom surface of the recess 32 pushes the flare 1b. However, the punch die 13 may push only the flare 1b.

  Further, if the movable die 19 and the end surface of the pipe 1 are pushed simultaneously with the tip surface of the punch die 13, the processing of the flare 1b at the end portion of the pipe can be omitted.

  FIG. 3 shows a method of processing the flare 1b. The straight clamp die 33 and the punch die 34 that hold the pipe 1 are used. As shown in FIG. The side is fixed so as to protrude by a predetermined length, and as shown in FIG. 3B, one end side of the pipe 1 is pressed by the punch die 34, whereby the protruding portion is bent to process the flare 1b.

  The pipe expanded diameter portion processing apparatus of the present invention is configured as described above. Next, a pipe expanded diameter portion processing method using the pipe expanded diameter section processing apparatus will be described.

  First, as shown in FIG. 3 (a), a straight clamp die 33 and a punch die 34 are used, and the pipe 1 is held with the straight clamp die 33 so that one end of the pipe 1 protrudes by a predetermined length, as shown in FIG. 3 (b). In this way, the projecting portion of the pipe 1 is bent by pressing one end side of the pipe 1 with the punch die 34, and the flare 1b is integrally processed on one end side as shown in FIG.

  Next, as shown in FIG. 1, the pipe 1 is set on the clamp die 11, the lower die 14 and the upper die 15 are closed so that the flare 1 b comes into contact with the tip surface of the movable die 19, and the pipe 1 is clamped. Hold horizontally with mold 11.

  When the punch die 13 is moved forward toward the clamp die 11 in this state, the liquid injection shaft 12 enters the pipe 1 from the opening on one end side, and the total length of the protruding portion of the liquid injection shaft 12 is the pipe 1. When the punch die 13 enters, the tip surface of the punch die 13 comes into contact with the tip surface of the movable die 19, and at the same time, the pushing surface comes into contact with the end surface of the flare 1 b. The movable mold 19 is pushed in, and at the same time, the pipe 1 is pressed in the axial direction from one end side, and stress is applied.

  In the clamp mold 11, when the movable mold 19 is pushed and the rear end comes into contact with the fixed mold 18 and stops, the distance between the distal end surface of the extension portion 21 of the fixed mold 18 and the distal end surface of the fitting recess 23 of the movable mold 19 is increased. By shortening by the moving stroke, the enlarged diameter portion forming space 27 adapted to the enlarged diameter portion 1a is formed.

  In addition, since stress is applied by being pressed in the axial direction from one end side, the pipe 1 has the liquid injection shaft 12 inserted therein, so that the portion facing the enlarged diameter portion forming space 27 serving as a refuge is on the outer side in the radial direction. Will buckle.

  Since the injection port 29 provided in the liquid injection shaft 12 of the punch mold 13 is provided at a position corresponding to the enlarged diameter portion forming space 27, the injection port is provided from the outside of the punch mold 13 in accordance with the occurrence of buckling of the pipe 1. By supplying a pressure liquid to the pipe 29 and applying a liquid pressure from the inlet 29 into the pipe 1, the buckling part is extended in the radial direction by the liquid pressure, so that the pipe 1 conforms to the shape of the enlarged diameter part forming space 27. The expanded diameter portion 1a is formed.

  As described above, the pressure pressed in the axial direction from the one end side applies hydraulic pressure from the inner diameter side to the portion of the pipe 1 that buckles into the enlarged diameter portion forming space 27 so that the buckled portion extends in the radial direction. By doing so, it is possible to form a diameter-enlarged portion 1 a having a high dimension and shape accuracy suitable for the shape of the enlarged-diameter portion forming space 27 in a part of the pipe 1.

  Thereafter, the supply of the pressure liquid is stopped, the punch die 13 is moved backward, the liquid injection shaft 12 is extracted from the pipe 1, the upper die 15 of the clamp die 11 is separated, the pipe 1 is released, and the lower die 14 is released. If the pipe 1 is taken out from the pipe, as shown in FIG. 4 (b), the flare 1b at the end and the pipe 1 in which the enlarged diameter portion 1a is processed in the vicinity of the flare 1b are obtained.

  In the above-described processing method, the pipe 1 to be processed is not limited to copper, brass, aluminum, or the like, and the pipe 1 in which the diameter-expanded portion 1a is processed may be used for various devices used for a water feeder, a hot water terminal, and the like. It can be used not only for fluid piping but also for automobile fluid piping.

  In addition, although the pipe 1 which processed the enlarged diameter part 1a of the example of illustration shows the example which becomes a part which ensures the watertightness of a connection part by insertion of an O-ring etc. between the flare 1b and the enlarged diameter part 1a. The diameter 1a may be used or provided at a required location such as in the middle of the pipe 1 for the purpose of preventing the connection portion from coming off.

  Moreover, although the pipe 1 used for processing illustrated the short straight pipe in the case of illustration, since this invention presses from one end part of the pipe 1 and applies stress, it is a space-saving apparatus with respect to the long pipe 1 However, not only can the enlarged diameter portion 1a be processed, but if there is a straight portion that can be held by the clamp die 11 at the end, the enlarged diameter portion can also be processed into a bent pipe that has been bent in advance.

Longitudinal front view showing the state of the expanded diameter portion processing device of the pipe before the expanded diameter portion processing Longitudinal front view showing the state during processing of the expanded diameter part of the expanded diameter part processing device of the pipe The apparatus which processes flare in the edge part of the pipe 1 is shown, (a) is a longitudinal cross-sectional view which shows the state before flare processing, (b) is a longitudinal cross-sectional view which shows the state at the time of flare processing (A) is a longitudinal sectional view of a pipe with a flare processed at the end, and (b) is a longitudinal sectional view of a pipe with a flare and a diameter-expanded portion processed. A conventional hydraulic basil molding method is schematically shown, in which (a) is a longitudinal front view showing a state before machining of the enlarged diameter portion, and (b) is a longitudinal front view showing a state during machining of the enlarged diameter portion.

Explanation of symbols

1 Pipe 1a Expanded portion 1b Flare 11 Clamp die 12 Liquid injection shaft 13 Punch die 14 Lower die 15 Upper die 16 Clamp portion 17 Recessed portion 18 Fixed die 19 Movable die 20 Fitting groove 21 Extension portion 22 Guide 23 Fitting recess 24 fitting portion 26 spring 27 enlarged diameter portion forming space 28 connecting portion 29 inlet 30 passage 31 watertight means 32 recessed portion 33 straight clamp die 34 punch die

Claims (2)

  The pipe is held by a clamp mold having a space for forming an enlarged diameter portion, and an axial stress is applied to the pipe from one end with a punch mold, and the diameter of the pipe is increased from an inlet of a liquid injection shaft provided in the punch mold. By applying hydraulic pressure from the inside to the position facing the part forming space and buckling part of the pipe in the enlarged diameter part forming space with axial stress, and at the same time extending the buckling part in the radial direction with hydraulic pressure, A method for processing an enlarged-diameter part of a pipe, wherein an enlarged-diameter part adapted to the shape of the enlarged-diameter part forming space is formed on the pipe.   A clamp mold that forms a large-diameter portion forming space defined on the outside of the pipe with a fixed mold when the movable mold that fits on the pipe is pushed a predetermined stroke while the pipe is held firmly, and the clamp mold is used to hold the pipe. A liquid injection shaft that fits into one pipe from one end, and a punch mold that pressurizes the pipe axially from one end and simultaneously pushes the movable mold. The injection port is formed at a position corresponding to the space for forming the enlarged diameter portion when inserted into the pipe, and is provided with an inlet for discharging the hydraulic pressure supplied from the outside of the punch die into the pipe, and watertight means for the pipe inner diameter on both sides thereof. Pipe diameter expansion processing equipment.

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