JP2004351487A - Apparatus for modifying thickness of pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for modifying the thickness of a pipe with which an optional portion in the pipe can be modified by working into the optional thickness with a small working force. <P>SOLUTION: This apparatus for modifying the thickness of the pipe is composed of an outer die 1 disposed under outer-fitting state to the pipe P and an inner mechanism 2 disposed in the inner part of the above pipe P. The inner mechanism 2 can expand/shrink in radial state to the center of the pipe P, and an outer peripheral rollers 5a-5d for roll-moving on the inner peripheral surface of the pipe P are provided. After disposing the inner mechanism 2 to a prescribed position of the pipe P under shrinking state of the diameter in the outer peripheral rollers 5a-5d, while pushing and crushing the pipe P between the diameter-expanded outer peripheral rollers 5a-5d and the outer die 1, the inner mechanism 2 is relatively rotated in the axial surrounding direction of the pipe P to the pipe P and shifted to the axial direction and thus, the thin thickness portion X is formed in the pipe P. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pipe thickness changing device capable of processing and changing an arbitrary portion of a pipe to an arbitrary thickness with a small processing force.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, various techniques for processing the pipe end and thickness of a pipe are known (see Patent Document 1).
[0003]
For example, when the pipe is applied to an exhaust pipe of an automobile, it is desirable to form the exhaust pipe as thin as possible in order to reduce the weight of the automobile or to promote a catalytic action in a double pipe of an exhaust manifold. Since the pipe has a thick wall and a part requiring high strength, such as a welded portion at both ends, it is difficult to form the entire exhaust pipe with a thin wall.
[0004]
Therefore, a pipe wall thickness changing device capable of processing and changing any part of the exhaust pipe to an arbitrary thickness, such as forming a part requiring high strength in the exhaust pipe with a thick wall and forming other parts with a thin wall. Development is underway.
[0005]
FIG. 5 shows a conventional pipe thickness changing device used for processing an exhaust pipe. When a thin wall portion is formed in a pipe, the pipe 01 is sandwiched between an outer die 02 and an inner plug 03. When the inner plug 03 is pushed in the direction of the arrow, the inner plug 03 is squashed between the inner die 03 and the outer die 02 while making the entire surface in contact with the inner peripheral surface of the pipe 01, thereby forming a thin portion 04.
[0006]
The pipe 01 may be pulled while being crushed between the outer die 02 and the inner plug 03.
[0007]
[Patent Document 1]
JP-A-2000-24802 (pages 1-3, FIG. 2)
[0008]
[Problems to be solved by the invention]
However, in the conventional pipe thickness changing device, the processing force applied to the pipe when processing the pipe is excessive, and the processing force may cause the pipe to buckle or crack.
[0009]
In addition, since the pipe must be processed from the end, only the middle part of the pipe cannot be partially thinned, and as a result, it cannot be applied to the exhaust pipe of an automobile. Was.
[0010]
It should be noted that, when the pipe is manufactured, the material is partially thinned in advance and formed into a tube, or the thickness of the pipe is changed by stretching the hot pipe in the axial direction. In addition, it is practically impossible because it cannot cope with a wide variety of products.
[0011]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a pipe thickness changing device capable of processing and changing an arbitrary portion of a pipe to an arbitrary thickness with a small processing force. It is in.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, an outer die is provided so as to be fitted on the pipe.
An inner mechanism disposed inside the pipe, the inner mechanism radially expandable and contractable with respect to the center of the pipe, and an outer roller that rolls on an inner peripheral surface of the pipe; After the roller is placed at a predetermined position of the pipe with the diameter reduced, the outer mechanism is expanded and the inner mechanism is rotated around the pipe axis relative to the pipe while pressing and crushing the pipe with the outer die. A thin portion is formed in the pipe by rotating in the direction and moving in the axial direction.
[0013]
According to a second aspect of the present invention, in the pipe thickness changing device according to the first aspect, a plurality of outer peripheral rollers are disposed concentrically with respect to the center of the pipe, and a shaft having a tapered surface is disposed at the center. By moving the shaft in the axial direction of the pipe, the outer peripheral roller slides on the tapered surface to radially expand and contract.
[0014]
According to a third aspect of the present invention, in the pipe thickness changing device according to the first or second aspect, both ends of the pivot that rotatably supports the outer peripheral roller are formed radially with respect to the center of the pipe. It is characterized by being supported by a shaft.
[0015]
Function and effect of the present invention
According to the first aspect of the present invention, the pipe thickness changing device includes an outer die that is arranged so as to be fitted on the pipe, and an inner mechanism that is arranged inside the pipe.
[0016]
In addition, the inner mechanism includes an outer peripheral roller that can radially expand and contract with respect to the center of the pipe and that rolls on the inner peripheral surface of the pipe.
[0017]
Then, after disposing the inner mechanism at a predetermined position of the pipe with the outer peripheral roller reduced in diameter, the inner mechanism is moved to the pipe while expanding the outer peripheral roller and pressing and crushing the pipe with the outer die. A relatively thin portion is formed in the pipe by relatively rotating the pipe around the axis and moving the pipe in the axial direction.
[0018]
Therefore, since the inner mechanism can be started after the inner mechanism is arranged at a predetermined position of the pipe, that is, at a position where a thin portion is formed, it is not necessary to start the processing from the pipe end as compared with the conventional invention. Can be processed to form a thin portion.
[0019]
Further, the thickness of the pipe in the thin portion can be arbitrarily set by the amount of movement of the outer peripheral roller to expand the diameter.
[0020]
In addition, since processing is performed while rotating the inner mechanism and the pipe relatively in the direction around the axis of the pipe, at this time, the outer peripheral roller rotates while sliding at a point contact with the inner peripheral surface of the pipe. As described above, the pipe can be machined with a smaller machining force as compared with the case where the entire surface is in contact with the inner peripheral surface of the pipe.
[0021]
Further, since the thin portion of the pipe is crushed by the pressing force of the outer peripheral roller and the outer die, unlike the cutting process, the thin portion can have the same rigidity as other portions similarly to the flow forming process.
[0022]
Further, by continuously changing the moving amount of the outer peripheral roller to increase the diameter, it is possible to form a pipe having a thickness that is continuously changed without a step, and the pressure loss of the medium flowing inside the pipe can be arbitrarily reduced. Can be changed.
[0023]
According to the second aspect of the present invention, the outer peripheral roller can be slid on the tapered surface to expand and contract radially in accordance with the amount of movement of the shaft in the axial direction of the pipe. The thickness of the thin portion can be set accurately and easily by scaling.
[0024]
Further, by arranging a plurality of outer peripheral rollers at concentric positions with respect to the center of the pipe, the inner surface of the pipe can be processed with a uniform force, and a thin portion can be formed in a stable shape.
[0025]
In the invention according to claim 3, both ends of the pivot that rotatably supports the outer peripheral roller are supported by bearing surfaces formed radially with respect to the center of the pipe. It is possible to smoothly expand and contract radially with respect to the center.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the pipe thickness changing device of the present invention will be described.
[0027]
1 is a sectional side view showing a pipe thickness changing device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line S2-S2 of FIG. 1, FIG. 3 is a sectional view taken along line S3-S3 of FIG. It is a figure explaining the processing of the pipe in the pipe thickness change device of the form.
[0028]
As shown in FIGS. 1 and 2, the pipe thickness changing device A according to the present embodiment includes an outer die 1 that is arranged so as to be fitted on a pipe P, and an inner mechanism 2 that is arranged inside the pipe P. It is formed as a main configuration.
[0029]
The outer die 1 is for crushing and processing a pipe with an outer peripheral roller 5 described later, and is arranged in a state of contacting the outer peripheral surface of the pipe P.
[0030]
The inner mechanism 2 mainly includes a base 3, a shaft 4, an outer peripheral roller 5, and a plate 10. The base 3 is connected to a motor (not shown), and the rotation of the motor causes the entire inner mechanism 2 to be a pipe. It is formed so as to be rotatable around the axis of P.
[0031]
The shaft 4 is for radially expanding and contracting an outer peripheral roller 5 to be described later with respect to the center O of the pipe P, and is arranged coaxially with the axis of the pipe P. A center roller 7 having 7a is rotatably fixed.
[0032]
The outer peripheral roller 5 is composed of outer peripheral rollers 5a to 5d arranged concentrically with respect to the center O of the pipe P, and the outer peripheral rollers 5a to 5d are arranged in contact with the tapered surface 7a. .
[0033]
The outer peripheral rollers 5a to 5d are formed in a substantially columnar shape, and are rotatably supported by pivots 8a to 8d, respectively.
[0034]
The outer peripheral rollers 5a to 5d are chamfered.
[0035]
One side of each of the pivots 8a to 8d is rotatably supported by a bearing surface 9a provided on the base 3, and the other side is rotatably supported by a bearing surface 9b provided on a plate 10 described later.
[0036]
Further, as shown in FIG. 3, the bearing surface 9a is formed radially with respect to the center O of the pipe P, and the direction of expansion and contraction of the outer peripheral rollers 5a to 5d described later is radially formed with respect to the center of the pipe P. Regulating.
[0037]
The bearing surface 9b is formed radially with respect to the center O of the pipe P similarly to the bearing surface 9a, and the direction of expansion and contraction of the outer peripheral rollers 5a to 5d is radially defined with respect to the center O of the pipe P. Is regulated.
[0038]
The plate 10 is fixed to the base 3 by four bolts B, and the bolts pass through and fix roller guides 6a to 6d provided between the outer peripheral rollers 5a to 5d.
[0039]
The roller guides 6a to 6d are formed so as to surround the adjacent outer rollers, and the outermost ends D of the outer rollers 5a to 5d projecting from between the roller guides 6a to 6d are formed on the inner surface of the pipe P. By contact, the outer peripheral rollers 5a to 5d are formed so as to roll on the inner peripheral surface of the pipe P.
[0040]
Hereinafter, the processing of the pipe P of the pipe thickness changing device A of the present embodiment will be described with reference to FIG.
[0041]
For example, when the intermediate portion of the pipe P is formed into a thin portion using the pipe thickness changing device A configured as described above, first, as shown in FIG. The inner mechanism 2 is moved at a predetermined position inside the pipe P by being moved while being sandwiched between the outer peripheral rollers 5a to 5d having a diameter.
[0042]
Subsequently, when the shaft 4 of the inner mechanism 2 is pulled and moved in the direction of the arrow, the outer peripheral rollers 5a to 5d slide on the tapered surface 7a to radially increase in diameter, and as a result, the pipe P becomes the outer peripheral rollers 5a to 5d. Is crushed to a predetermined thickness between the outermost end D and the outer die 1.
[0043]
At this time, the amount of movement of the outer peripheral roller 5 can be determined according to the amount of movement of the shaft 4, and as a result, the thickness of the thin portion of the pipe P can be set arbitrarily.
[0044]
In addition, both ends of the pivot 8 of the outer peripheral rollers 5a to 5d slide on the bearing surfaces 9a and 9b and smoothly move radially with respect to the center O of the pipe P without useless resistance.
[0045]
Subsequently, as shown in FIG. 4B, the inner mechanism 2 is rotated around the axis with respect to the pipe P, and is gradually moved in the direction of the arrow with the holding mechanism (not shown) sandwiching the pipe P. Thereby, a thin portion X is formed.
[0046]
At this time, the range in which the thin portion X is formed can be set by the amount of movement of the pipe P by the holding means.
[0047]
Further, since the outer peripheral rollers 5a to 5d roll on the inner peripheral surface of the pipe P at the outermost end D and press and crush the pipe P with the outer die 1, a uniform force is applied to the pipe P to reduce the thickness. The shape of the portion X is stabilized, and the pipe P can be changed to a thin wall with a small working force.
[0048]
The operation of expanding the outer peripheral roller 5 and the operation of moving the pipe P by the holding means are performed at an arbitrary timing. In some cases, the outer peripheral roller 5 is continuously expanded while reciprocating the pipe P. It is appropriately performed depending on the material and specification of the product, such as gradually forming a thin wall.
[0049]
Therefore, in the pipe thickness changing device A of the present embodiment, after the inner mechanism 2 is arranged at a predetermined position of the pipe P with the outer peripheral rollers 5a to 5d reduced in diameter, the outer peripheral rollers 5a to 5d are removed. A simple operation of rotating the inner mechanism 2 around the axis of the pipe P relative to the pipe P and moving the inner mechanism 2 in the axial direction while pressing and crushing the pipe P between the outer die 1 and the outer diameter 1. Therefore, not only the end portion of the pipe P but also the intermediate portion can be processed and changed to an arbitrary thickness, and both ends where high strength is required, such as an exhaust pipe, are thick, and other portions are formed thin. For example, it is possible to achieve both light weight and high strength of the exhaust pipe.
[0050]
Further, since the outer peripheral rollers 5a to 5d roll on the inner peripheral surface of the pipe P at the outermost end portion D, the pipe P can be processed with less force than in the conventional invention, and buckling of the pipe P can be prevented.
[0051]
Further, by continuously changing the amount of movement of the outer peripheral roller 6 to increase the diameter and the amount of movement of the pipe P in the axial direction, it is possible to form a pipe having a thickness that is continuously changed without a step. Application to various pipes can be realized.
[0052]
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.
[0053]
For example, while the outer peripheral rollers 5a to 5d of the present embodiment have been described as being supported by the pivots 8a to 8d, the outer peripheral rollers are formed into spherical shapes like ball bearings, and the outermost ends of the pipes P are formed. The case of rolling on the inner peripheral surface is also included in the category of the present invention.
[0054]
Further, as long as the pipe is plastically deformed, it can be applied to various kinds of materials such as metal such as iron, stainless steel, aluminum and titanium, reinforced glass fiber, and plastic.
[0055]
Further, the rotation and movement of the inner mechanism 2 and the pipe P at the time of processing according to the present embodiment may be relative operations, and the inner mechanism 2 and the pipe P are taken into consideration in consideration of the load on the pipe and the compactness of the apparatus. It may be determined whether one or both of the Ps are rotated and moved.
[0056]
Further, it goes without saying that the pipe wall thickness changing device of the present invention can be operated under both cold and hot conditions of the pipe.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a pipe thickness changing device according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along line S2-S2 of FIG.
FIG. 3 is a sectional view taken along line S3-S3 of FIG.
FIG. 4 is a diagram illustrating processing of a pipe in the pipe thickness changing device according to the present embodiment.
FIG. 5 is a view for explaining processing of a pipe in a conventional pipe thickness changing device.
[Explanation of symbols]
Reference Signs List 1 outer die 2 inner mechanism 3 base 4 shaft 5, 5a, 5b, 5c, 5d outer peripheral rollers 6, 6a, 6b, 6c, 6d roller guide 7 center roller 7a tapered surfaces 8a, 8b, 8c, 8d pivot 9 center roller 9a 9b Bearing surface 10 plate

Claims (3)

An outer die arranged in a state of being fitted to the pipe,
Consisting of an inner mechanism arranged inside the pipe,
The inner mechanism is radially expandable and contractable with respect to the center of the pipe, and includes an outer peripheral roller that rolls on an inner peripheral surface of the pipe,
After arranging the inner mechanism at a predetermined position of the pipe with the outer peripheral roller reduced in diameter, the inner mechanism is moved relative to the pipe while expanding the outer peripheral roller and pressing and crushing the pipe with the outer die. A pipe thickness changing device, wherein a thin wall portion is formed in a pipe by rotating the pipe in a direction around an axis of the pipe and moving the pipe in an axial direction. The pipe thickness changing device according to claim 1,
A plurality of the outer peripheral rollers are arranged concentrically with respect to the center of the pipe, and a shaft having a tapered surface is arranged at the center.
A pipe thickness changing device, wherein the shaft is moved in the axial direction of the pipe so that an outer peripheral roller slides on the tapered surface to radially expand and contract. The pipe thickness changing device according to claim 1 or 2,
A pipe thickness changing device, wherein both ends of a pivot that rotatably supports the outer peripheral roller are supported by bearing surfaces formed radially with respect to the center of the pipe.

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