JP2004098080A - Core bar structure of double-tube bending device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate bending defects by wrinkles of the inner tube at the time of bending a double-tube. <P>SOLUTION: An end section of the double-tube composed of an inner tube 2a and an outer tube 2b is pinched by a rotatable bender and a revolvable closed die which rotates around the bender, and a bending mechanism 3 to bend the double-tube 2 by revolutionizing the closed die, an outer core bar 41 provided between the inner tube 2a and the outer tube 2b of the double-tube 2, an inner core bar 43 provided inside the inner tube 2a of the double-tube 2, an core bar shaft 47 to press the double-tube 2 provided with the outer core bar 41 and the inner core bar 43 to the bending mechanism are provided and reduction of the diameter is admitted to the outer core bar 41 in accordance with the power given at the time of bend-deforming the double-tube 2 and a split slot is so designed as to shorten the clearance gap between the inner tube 2a and the inner core bar 43, and the inner tube 2a and the outer core bar 41. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a core metal structure of a double pipe bending apparatus used for, for example, exhaust pipes for automobiles and heat insulating pipes.
[0002]
[Prior art]
Conventionally, as a double pipe bending apparatus of this type, a double pipe bending method and an apparatus described below have been known (see Patent Document 1).
As shown in FIGS. 5 and 6, this type of double pipe bending apparatus 1 includes a bending mechanism 3 for bending a double pipe 2 including an inner pipe 2a and an outer pipe 2b, and the bending mechanism. A double tube pushing mechanism 6 for feeding the double tube 2 to the unit 3, two rails 15 for moving the carriage 13 of the double tube pushing mechanism 6, and a gantry 11 receiving a reaction force of the double tube 2 when pressed. And the apparatus main body 14 provided.
[0003]
As shown in FIG. 5, the bending mechanism 3 holds the distal end portion 2A of the double pipe 2 with a rotatable bending die 4 and a clamping die 5 that can revolve around the bending die 4. 5 is revolved to bend the double pipe 2.
As shown in FIGS. 5 and 6, the double tube pushing mechanism 6 has three claws (two are shown in the drawings) for holding the rear end 2b1 of the outer tube 2b of the double tube 2. A chuck mechanism 7 having a chuck 7a, an outer metal core 8 inserted through the chuck mechanism 7, an inner metal core 9 disposed inside the outer metal core 8, and a rear end portion of the inner metal core 9. A core metal shaft 10 supported by the gantry 11, an inner tube pushing jig 12 arranged inside the chuck mechanism 7, a carriage 13 for pressing the chuck mechanism 7 toward the bending mechanism 3, and a core metal shaft. A shaft 16 that externally fits the cylinder 10 and communicates with the inner tube pushing jig 12, a cylinder rod 17 that externally fits the metal core shaft 10 and communicates with the shaft 16, and an inner tube pushing cylinder 18 that externally fits the cylinder rod 17. And the carriage 13 And a torsion pulley 20 for applying a twist to the chuck mechanism 7 via the rotation shaft 19, and a motor 21 for communicating with the torsion pulley 20 via a belt 22. I have.
[0004]
Next, bending by the double pipe bending apparatus 1 will be described.
First, the rear end 2B of the double pipe 2 is guided toward the chuck mechanism 7, the inner pipe 2a is disposed between the outer core 8 and the inner core 9, and the rear end 2a1 of the inner pipe 2a is connected to the inner pipe. The outer tube 2b is disposed outside the outer cored bar 8 in contact with the pressing jig 12, and the rear end 2b1 of the outer tube 2b is in contact with the chuck mechanism 7.
[0005]
Next, a pressurized fluid is supplied to the chuck mechanism 7 to move the three claws 7a in the center direction to hold the rear end 2b1 of the outer tube 2b.
Next, the carriage 13 is moved along the rail 15, the tip 2A of the double pipe 2 is arranged between the bending die 4 and the clamping die 5, and the bending die 4 Stops, the movement of the carriage 13 is stopped.
[0006]
Next, the clamping die 5 is moved toward the bending die 4, and the double tube 2 is sandwiched between the bending die 4 and the clamping die 5, and the pressure die 5 a is brought into contact with the outer periphery of the double tube 2. By rotating the bending arm 5b, the clamping die 5 revolves around the bending die 4. During this bending process, a pushing force is continuously applied from the rear end 2B side of the double pipe 2.
In this way, the press bending process according to the shape of the double pipe 2 is performed.
[0007]
[Patent Document 1]
JP-A-10-118719 (pages 2-4, FIG. 5)
[0008]
[Problems to be solved by the invention]
However, in such a conventional double pipe bending apparatus, when the bending arm 5b is rotated to revolve the closing die 5 around the bending die 4 and the double pipe 2 is bent, the double pipe 2 is bent. There is a problem that a gap is formed between the inner tube 2a and the outer core metal 8 and the inner core metal 9 due to the bending deformation force, and wrinkles are generated in the inner tube 2a to cause a problem in bending.
The present invention has been made to solve such a conventional problem, and an object of the present invention is to prevent wrinkles generated in an inner pipe at the time of bending a double pipe and to avoid a problem of bending. It is an object of the present invention to provide a cored bar structure of a double pipe bending apparatus capable of bending.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 is characterized in that one end of a double pipe composed of an inner pipe and an outer pipe is sandwiched between a rotatable bending die and a clamping die capable of revolving around the bending die, and the clamping die is A bending mechanism for revolving and bending the double pipe, an outer metal core disposed between the inner pipe and the outer pipe of the double pipe, and a bending mechanism disposed inside the inner pipe of the double pipe. An inner metal core, and a metal core shaft for pressing the double pipe against the bending mechanism, wherein the outer core metal is allowed to reduce its diameter according to the force at the time of bending deformation of the double pipe. In addition, a split groove for reducing a gap between the inner pipe and the inner core metal or the outer core metal is formed.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on embodiments shown in the drawings.
1 to 4 show a double pipe bending apparatus 30 according to one embodiment of the present invention.
In the double pipe bending apparatus 30 according to one embodiment of the present invention, the carriage, the chuck mechanism, the bending mechanism, and the apparatus main body have the same configuration as the conventional double pipe bending apparatus 1 shown in FIG. Therefore, in the following description, the double tube pushing mechanism, which is a main part of the invention, will be described, and the illustration and description thereof will be omitted.
[0011]
The double pipe pushing mechanism 40 includes an outer core 41 disposed between the inner pipe 2 a and the outer pipe 2 b of the double pipe 2, and an inner core disposed inside the inner pipe 2 a of the double pipe 2. 43, a slide rod 45 disposed on the rear end 43b of the inner core 43, a core shaft 47 disposed between the slide rod 45 and the gantry 11, and an inner tube 2a disposed on the slide rod 45. And a push ring 51 fixed to the slide rod 45 and in contact with the rear end 2b1 of the outer tube 2b.
[0012]
The outer mandrel 41 and the inner mandrel 43 are provided with R around the entire periphery of the distal end portions 41a and 43a on the bending mechanism 3 side so as to follow the torsion applied to the double pipe 2 during bending.
[0013]
Further, as shown in FIG. 2, in order to improve the insertability of the inner tube 2a, the gap between the outer core metal 41 and the inner core metal 43 has a margin of + α in addition to the thickness of the inner tube 2a. I have.
Further, the outer metal core 41 is provided with a split groove 41c formed at the tip portion 41a on the bending mechanism 3 side, and the split groove 41c has a width w and is split near the center of the outer metal core 41. ing.
[0014]
The rear end portion 41b of the outer cored bar 41 is connected to the outer holding ring 53 via an outer cored bar holder 55 having an opening 56 for projecting the four push claws 51 respectively.
[0015]
As shown in FIGS. 3 and 4, the outer metal core holder 55 is composed of four plate members, and both ends 55 a and 55 b are respectively provided at the rear end 41 b of the outer metal core 41 and the tip of the outer holding ring 53. 53a are fitted into the recesses respectively formed and fixed by Tig welding.
The outer holding ring 53 is screwed to the core shaft 47. A fixing nut 57 is attached to the rear end of the outer holding ring 53 to prevent movement.
[0016]
The push claw 51 is fixed to the slide ring 49 by a screw 52 as shown in FIGS.
As shown in FIG. 1, the push claw 51 is held by four claws 7 a of the chuck mechanism 7. In FIG. 5 described in the related art, the description is made using three claws 7a, but in the present embodiment, the claws 7a are arranged for every four push claws 51.
[0017]
Next, the operation of the double pipe bending apparatus 30 according to the present embodiment will be described. First, the rear end 2B of the double pipe 2 is guided toward the chuck mechanism 7, the inner pipe 2a is disposed between the outer core 41 and the inner core 43, and the rear end 2a1 of the inner pipe 2a is slid. 49, the outer tube 2b is arranged outside the outer metal core 41, and the rear end 2b1 of the outer tube 2b contacts the chuck mechanism 7.
[0018]
Next, a pressurized fluid is supplied to the chuck mechanism 7 to move the four claws 7a in the center direction to hold the four push claws 51. As a result, the rear end 2b1 of the outer tube 2b is fixed.
Next, the carriage 13 is moved along the rail 15 so that the tip 2A of the double pipe 2 is disposed between the bending die 4 and the clamping die 5, and the bending die 4 Stops, the movement of the carriage 13 is stopped.
[0019]
Next, the clamping die 5 is moved toward the bending die 4, and the double tube 2 is sandwiched between the bending die 4 and the clamping die 5, and the pressure die 5 a is brought into contact with the outer periphery of the double tube 2. By rotating the bending arm 5b, the clamping die 5 is revolved around the bending die 4 to perform bending.
At the time of this bending, the diameter of the outer metal core 41 is reduced by the width w of the split groove 41c according to the force at the time of bending deformation of the double pipe 2, and the inner pipe 2a, the inner metal core 43, and the outer metal core 41 By filling the gap (+ α), wrinkling of the inner tube 2a is prevented, and the problem of bending is avoided.
[0020]
During the bending process, the double-pipe pushing mechanism 40 also pushes the pushing claws 51 by the chuck mechanism 7 and moves on the apparatus main body 14 by the carriage 13 to move the rear ends 2a1, 2b1 of the inner pipe 2a and the outer pipe 2b. Is pressed in the direction of the bending mechanism 3.
[0021]
In this way, the press bending process according to the shape of the double pipe 2 is performed.
As described above, in the present embodiment, the split groove 41c of the outer metal core 41 is deformed according to the force at the time of bending deformation of the double pipe during bending, and the inner pipe 2a, the outer metal core 41, and the inner core 41 are deformed. Since the gap (+ α) with the gold 43 is filled, wrinkling of the inner tube 2a can be prevented.
In addition, since the gap between the outer core 41 and the inner core 43 has a margin of + α in addition to the thickness of the inner tube 2a, the inner tube 2a can be smoothly inserted into these gaps. Become.
[0022]
Further, the double tube pushing mechanism 40 bends the rear ends 2a1, 2b1 of the inner tube 2a and the outer tube 2b when the push claw 51 is gripped by the chuck mechanism 7 and moves on the apparatus main body 14 by the carriage 13. Since it can be pressed in the direction of the processing mechanism 3, it is not necessary to prepare a long cylinder device that reaches the gantry 11 to press the rear end portion 2a1 of the inner tube 2a as in the related art. Thus, it becomes possible to perform the same bending process as in the related art.
[0023]
The embodiment of the present invention has been described above. However, the specific configuration of the present invention is not limited to the present embodiment, and the present invention is applicable even if there is a design change without departing from the gist of the invention. include.
For example, in the present embodiment, a case where four push claws 51 are used has been described, but three push claws 51 may be used in correspondence with a conventional chuck mechanism.
Further, the shape, width, length, and the number of split grooves 41c provided in the outer cored bar 41 can be appropriately set.
[0024]
【The invention's effect】
As described above, in the core structure of the double pipe bending apparatus according to claim 1 of the present invention, since the above-described configuration is employed, the split groove reduces the force at the time of deformation when bending the double pipe. Accordingly, by reducing the gap between the inner tube and the inner core metal or the outer core metal, it is possible to avoid the occurrence of wrinkles in the inner tube and to prevent bending problems.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a main part of a double pipe bending apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing an outer metal core of the double pipe bending apparatus according to the present embodiment.
FIG. 3 is an arrow view along the line AA in FIG. 1;
FIG. 4 is an explanatory view showing a state of connection with an outer core, an outer core holder, and an outer holding ring.
FIG. 5 is a perspective view showing a conventional double pipe bending apparatus.
FIG. 6 is a sectional view showing a main part of FIG. 5;
[Explanation of symbols]
2 Double tube 2a Inner tube 2A Tip 2a1, 2b1, 2B Rear end 2b Outer tube 3 Bending mechanism 4 Bending mold 5 Clamping mold 5a Pressure mold 5b Bending arm 7 Chuck mechanism 7a Claw 11 Mount 13 Carriage 14 Machine body 15 Rail 30 Double pipe bending apparatus 40 Double pipe pushing mechanism 41 Outer cores 41a, 43a, 53a Tip 41b, 43b Rear end 41c Split groove 43 Inner core 45 Slide rod 47 Core shaft 49 Slide ring 51 Push Claw 52 Screw 53 Outer holding ring 55 Outer core holder 55a, 55b Both ends 56 Opening 57 Fixing nut

Claims (1)

With a rotatable bending mold and a clamping mold capable of revolving around the bending mold, one end of a double pipe composed of an inner pipe and an outer pipe is sandwiched, and the clamping pipe is revolved to recycle the double pipe. A bending mechanism for bending,
An outer metal core disposed between the inner tube and the outer tube of the double tube,
An inner metal core disposed inside the inner pipe of the double pipe,
A core metal shaft that presses a double pipe provided with the outer core metal and the inner core metal to a bending mechanism,
A split groove is formed in the outer core to reduce the diameter of the double tube according to the force at the time of bending deformation, and to reduce the gap between the inner tube, the inner core, and the outer core. A cored bar structure for a double pipe bending apparatus.

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