JP3847224B2 - Manufacturing method of coil for electromagnetic tube expansion - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a coil for electromagnetic tube expansion used for metal electromagnetic forming.
[Prior art]
Electromagnetic tube expansion forms a very strong magnetic field in an extremely short time by instantly discharging the electric charge stored at a high voltage to the energizing coil, so that the workpiece placed in this magnetic field can repel the magnetic field. This is a technology that receives a strong expansion force and is pressed against the outer mold.
[0003]
Electromagnetic forming is suitable for forming an aluminum alloy, which is a good electrical conductor, and is used for forming a groove in an aluminum alloy tube or joining aluminum alloy tubes together. In addition, application of electromagnetic tube expansion forming is being studied for processing of bending the end of an aluminum alloy tube, processing of a large amount of deformation such as caulking of a large diameter tube, and processing of a high-strength material. For example, application to processing or caulking of frame materials such as vehicles, automobiles, and motorcycles is being studied.
[0004]
Conventionally, coils used for electromagnetic tube expansion molding have been disclosed in Japanese Patent Application Laid-Open No. 7-153617 and Japanese Patent Application Laid-Open No. 6-238356. Wire) and a space between conductive wires is filled with an insulating resin.
[0005]
[Problems to be solved by the invention]
However, if an electromagnetic tube expansion coil is to be manufactured by such a method, it is difficult to form the outer peripheral insulating resin covering the outside of the conducting wire with high precision. May be eccentric. When electromagnetic tube expansion molding is performed using such an eccentric coil, there is a problem that the tube expansion of the workpiece becomes extremely uneven.
[0006]
In addition, when performing the above-described high-strength material processing and processing with a large amount of deformation, since a large repulsive force is applied to the conductor wire itself, the eccentric coil may be damaged from a thin portion of the resin layer. . Furthermore, since the insulating resin of this part has a small coefficient of thermal expansion, when the coil is used repeatedly, the conductor strand expands due to Joule heat generated in the conductor strand, and the difference in thermal expansion from the insulating resin There is a problem that a gap is generated in the resin, causing damage.
[0007]
The present invention has been made in view of such problems, and can uniformly deform a workpiece during electromagnetic expansion, and can be used for electromagnetic expansion processing of high-strength materials and electromagnetic expansion processing of high deformation materials. An electromagnetic pipe expansion coil that can manufacture an electromagnetic pipe expansion coil that does not damage the insulating resin that covers the conductor wire and that does not damage the insulating resin or deteriorate the insulation performance even after repeated use. An object is to provide a manufacturing method.
[0008]
[Means for Solving the Problems]
The method for manufacturing an electromagnetic tube expansion coil according to the present invention is the same as the method for manufacturing an electromagnetic tube expansion coil in which a conductor wire whose periphery is covered with an insulator is wound around an insulating bobbin portion. A step of manufacturing the material integrally with the material, a step of positioning the axial centers of both ends of the bobbin portion with a center metal of a lathe, and forming a minimum diameter portion around which the conductor wire is wound by turning, A step of winding the conductor wire around the small-diameter portion, a step of impregnating the outer periphery resin around the periphery, and repositioning the shaft centers of both ends of the bobbin portion with a center presser of a lathe, and unnecessary portions of the outer peripheral resin And a step of removing by turning.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an electromagnetic tube expansion coil manufactured by an embodiment method of the present invention, FIG. 2 is a cross-sectional view showing a conductor wire thereof, and FIG. 3 is a view showing a bobbin portion.
[0010]
The bobbin portion 9 made of an insulating resin is a portion corresponding to the core of the coil. A flange portion 9a is provided at the base end portion of the bobbin portion 9 and the tip end portion is inserted into the workpiece. The bobbin portion 9 inserted into the workpiece has an intermediate diameter portion 11 having an intermediate outer diameter on the peripheral surface thereof from the proximal end side toward the distal end side in the coil axis direction and the outer diameter being the largest. The small minimum diameter portion 10, the intermediate diameter portion 11 having an intermediate outer diameter, and the maximum diameter portion 12 having the largest outer diameter are formed adjacent to each other in the coil axis direction. Then, a step 4 is formed by the difference in outer diameter between the intermediate diameter portion 11 and the maximum diameter portion 12 on the tip end side adjacent to each other, and the outer diameter between the minimum diameter portion 10 and the adjacent intermediate diameter portions 11 is formed. Two steps 5 are formed by the difference in diameter.
[0011]
On the other hand, the conductor wire 1 of the coil has a rectangular or square cross section. An insulating material 2 is wound around the conductor wire 1 to insulate the conductor. The conductor wire 1 is tightly wound around the minimum diameter portion 10 of the bobbin portion 9 by one layer. That is, the conductor wire 1 is wound around the circumferential surface of the minimum diameter portion 10 so as to fit into a recess formed between the two steps 5 between the minimum diameter portion 10 and the intermediate diameter portion 11. As shown in FIG. 2, the adjacent conductor wires 1 are in close contact with each other so that there is no gap. Therefore, if the thickness of the glass fiber 2 coated around the conductor wire 1 is T, the wire interval H between the conductor wires 1 adjacent in the coil axis direction is 2T. And the insulator 3 is coat | covered on the outer surface of these wound conductor strands 1 and the intermediate diameter part 11. FIG. The insulator 3 is held and fixed on the outer surface of the conductor wire 1 and the peripheral surface of the intermediate diameter portion 11 so as to fit into a recess formed between the step 4 and the flange 9a. In this way, the insulator 3 covers the conductor wire 1 and the intermediate diameter portion 11, and the thickness is such that the outer surface of the insulator 3 and the peripheral surface of the maximum diameter portion 12 are substantially flush. Have
[0012]
The conductor wire 1 of this embodiment is covered with an insulating material 2. The insulating material 2 is made of a fiber reinforced resin obtained by impregnating an epoxy resin or the like into glass fiber and the like. The insulating material 2 reinforces the periphery of the element wire. Deformation can be reduced. The cross section of the conductor wire 1 is such that opposing strand surfaces are parallel to each other, and when the thickness of the insulating material 2 is T, the arrangement pitch H of the conductor wires 1 is H = It is wound around the bobbin portion 9 so as to be 2T. For this reason, the insulation thickness between the wires becomes uniform, and only the reinforced insulating material 2 exists, so that even if an expansion force is applied to the coil by energization, the force is dispersed, thereby insulating the insulation. Layer breakage is reduced. In addition, since the surfaces of the adjacent conductor wires 1 are parallel to each other, there is little room for unnecessary voids to enter and impair the insulation properties during resin impregnation.
[0013]
Further, since the outer peripheral insulator 3 is held and fixed in the recess between the step 4 and the flange portion 9a, the outer peripheral insulator 3 insulates the conductor wire 1 and the workpiece, and the conductor strand 1 Is covered and held around it. Thereby, the outer periphery insulator 3 has the effect | action which prevents that the conductor strand 1 expand | swells outside by the force received at the time of electricity supply, and deform | transforms. Since the coil of the present embodiment has a structure in which there is substantially no gap between the conductor strands 1, thermal expansion of the conductor strand 1 is prevented and the conductor strand 1 is held on the peripheral surface of the bobbin portion 9. This is mainly a tightening force by the outer peripheral insulator 3, and by providing the step 4 at the end of the bobbin portion 9, the outer peripheral insulator 3 is firmly fixed to the bobbin portion 9, and as a result, the conductor is also used during use. The strand 1 is stabilized. The width of the step 4 (length in the coil axis direction) is preferably 10 mm or more in order to strengthen the fixation of the outer peripheral insulator 3.
[0014]
Next, the manufacturing method of the electromagnetic tube expansion coil comprised as mentioned above is demonstrated. First, the bobbin portion 9 (including the flange portion 9a) shown in FIG. 3 is integrally formed from the same material. In this way, by integrally forming the bobbin portion 9 and the flange portion 9a, as in the past, the bottom portion (flange portion) is joined to the bobbin portion when the bobbin portion is manufactured, and the use It is possible to prevent distortion from occurring at the joint surface at the time. Insulating resin is usually used as the material of the bobbin portion 9 and the flange portion 9a.
[0015]
In processing the bobbin portion 9, the axial centers of both ends of the bobbin material are positioned by a lathe tailstock, and the minimum diameter portion 10, the intermediate diameter portion 11 and the maximum diameter portion 12, which are portions where the conductor is wound, are turned. Formed by processing. Thereby, it is possible to wind the conductor wire wound in the subsequent process without decentering.
[0016]
Thereafter, the conductor wire 1 is wound around the minimum diameter portion 10 of the bobbin portion 9. As described above, the conductor strands 1 are covered with the glass fibers 2 to insulate the conductor strands 1 from each other. In addition, the winding method of this conductor strand 1 is wound around the bobbin part 9 so that it may become H = 2T, and, thereby, the conductor strand 1 adjoins in the state wound spirally. The surfaces of the conductor wire 1 are parallel to each other.
[0017]
Thereafter, the outer peripheral surface of the conductor wire 1 and the intermediate diameter portion 11 are impregnated with an insulating resin, and the outer peripheral insulator 3 is deposited. In this case, the conductor wires 1 are in close contact with each other with the insulating substance 2 interposed therebetween. For this reason, the inconvenience resulting from the difference of the thermal expansion coefficient between the conductor strand 1 and insulating resin can be avoided.
[0018]
Thereafter, the same axis center as that when the bobbin portion 9 is manufactured is positioned by a center presser of the lathe, and this shaft center is held and is turned again to remove an extra portion of the outer peripheral insulator 3. As a result, the outer peripheral surface of the outer peripheral insulator 3 becomes coaxial with the peripheral surface of the smallest diameter portion 10, and accordingly, the outer peripheral surface of the outer peripheral insulator 3, the outer peripheral surface of the conductor wire 1, and the outermost surface of the bobbin portion 9. The coil for electromagnetic tube expansion that is coaxial with the peripheral surface of the small-diameter portion 10 and has no eccentricity is manufactured. The workpiece can be uniformly formed by the electromagnetic tube expansion coil manufactured as described above. The bobbin part is turned even if it is filled with another resin by cutting or drilling a part of the bobbin part 9 because of the structural necessity when winding the conductor wire. If the shaft center at the time of machining and the shaft center at the time of turning the outer surface resin are the same, it is within the scope of the present invention.
[0019]
【The invention's effect】
As described above, according to the present invention, the minimum diameter portion of the bobbin portion is formed by turning on the basis of the same axis, and the outer peripheral surface of the outer peripheral insulator and the outer peripheral surface of the conductor wire And the peripheral surface of the minimum diameter part of a bobbin part becomes coaxial, and the coil for electromagnetic tube expansion without eccentricity can be manufactured. Therefore, the workpiece can be uniformly formed by the coil for electromagnetic tube expansion manufactured according to the present invention.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a conductor wire of an electromagnetic tube expansion coil according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the coil for electromagnetic pipe expansion, similarly.
FIG. 3 is a cross-sectional view showing the bobbin portion in the same manner.
[Explanation of symbols]
1: Conductor strand 2: Insulating material 3: Peripheral insulator 4, 5: Step 9: Bobbin portion 10: Minimum diameter portion 11: Intermediate diameter portion 12: Maximum diameter portion

Claims (1)

In a method of manufacturing an electromagnetic tube expansion coil in which a conductor wire whose periphery is covered with an insulating material is wound around an insulating bobbin portion, the step of manufacturing the bobbin portion integrally with the same material, and the bobbin portion Positioning the shaft centers of both ends of the lathe with a lathe tailstock, forming a minimum diameter portion for winding the conductor wire by turning, and winding the conductor wire around the minimum diameter portion; A step of impregnating a peripheral resin around the periphery, and a step of repositioning the shaft centers of both ends of the bobbin portion with a center presser of a lathe and turning and removing unnecessary portions of the peripheral resin. A method of manufacturing a coil for electromagnetic tube expansion, which is characterized.

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