JP2019130534A - Electromagnetic molding method - Google Patents

Abstract

To increase an extension quantity of a member in a necessary region in an electromagnetic molding technology.SOLUTION: An electromagnetic molding method extends a diameter of a hollow material using an electromagnetic coil 42 to fix a member to be fixed which is disposed outside the hollow material. The electromagnetic molding method extends the diameter of the hollow material while disposing a mold suppressing tool 44 for suppressing extension of the hollow material around an extended region.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for electromagnetically forming a hollow material using a coil for electromagnetic forming.

  An electromagnetic forming technique for performing plastic working on a metal member is known. In electromagnetic forming technology, an impulse voltage is applied to an electromagnetic forming coil to form a strong magnetic field in an extremely short time around it, and a workpiece is placed in this magnetic field, thereby A member to be processed is formed by generating an electromagnetic repulsive force between the processing member and the electromagnetic forming coil (Patent Document 1).

JP 09-166111 A

  By the way, in the electromagnetic forming technique, it is necessary that the fixed member can be reliably fixed. However, if the extended portion extends over a wide area from the periphery of the member to be fixed unnecessarily, the expansion of the member around the member to be fixed becomes gentle, and the fixing strength of the member to be fixed becomes weak. I was sorry.

  It is also desired to extend the life of the electromagnetic forming coil by reducing the applied voltage applied to the electromagnetic forming coil used for electromagnetic forming.

  One aspect of the present invention is an electromagnetic forming method for expanding a diameter of a hollow member using an electromagnetic forming coil and fixing a fixed member disposed outside the hollow member, wherein the region to be expanded is provided. In the electromagnetic molding method, the diameter of the hollow material is expanded in a state in which a mold holding tool that suppresses the expansion of the hollow material is disposed around.

  According to the present invention, it is possible to increase the amount of expansion of a member in a necessary region in the electromagnetic molding technique, and to stabilize the processing of the member. Moreover, the applied voltage applied to the electromagnetic forming coil can be reduced, and the life of the electromagnetic forming coil can be extended.

It is a perspective view which shows the example of the to-be-processed member to which the electromagnetic forming technique in embodiment of this invention is applied. It is a side view which shows the example of the to-be-processed member to which the electromagnetic forming technique in embodiment of this invention is applied. It is a figure for demonstrating the electromagnetic shaping technique in embodiment of this invention. It is a figure for demonstrating the electromagnetic shaping technique in embodiment of this invention. It is a figure which shows the example of the type | mold suppression in embodiment of this invention.

  1 and 2 are a perspective view and a front view showing a configuration example of a workpiece to be processed by the electromagnetic forming method according to the embodiment of the present invention. FIG. 2 is a front view in which a part of the workpiece shown in FIG. 1 is omitted.

  In the present embodiment, an example will be described in which the member to be processed is the fixed member-attached pipe 10 constituting the instrument panel reinforcement disposed in the instrument panel of the vehicle. The instrument panel reinforcement is arranged along the vehicle width direction in the instrument panel of the vehicle. The instrument panel is assembled to the instrument panel reinforcement. In addition, the application object of the electromagnetic generation method in this Embodiment is not limited to the pipe 10 with a to-be-fixed member, What is necessary is just the hollow material which can deform | transform with an electromagnetic force.

  The pipe with fixed member 10 includes a pipe 12 and a cowl brace 26 fixed from the outside of the pipe 12. The cowl brace 26 corresponds to a pipe fixed member. A plurality of second pipe fixing members are also fixed to the pipe 12 from the outside. The plurality of second pipe fixed members are a driver seat side extension (D side extension) 20, a steering support 22, a passenger seat side extension (P side extension) 27, and two outer brackets 28 and 29.

  The pipe 12 is a long annular member formed using a metal having high electrical conductivity such as an aluminum alloy. As will be described later, an electromagnetic coil is disposed inside the pipe 12, and by energizing the electromagnetic coil, the pipe 12 is expanded and deformed, and electromagnetic forming is performed in which a member is caulked and fixed to the outside.

  The pipe 12 includes a driver-seat-side pipe member (D-side pipe member) 14 disposed on one end side (left side in FIGS. 1 and 2) on the driver's seat side (D-side), and the other end of the D-side pipe member 14. And a passenger seat side pipe member (P side pipe member) 16 which is intubated and fixed from the outside to the portion (right end portion in FIGS. 1 and 2). The D-side pipe member 14 and the P-side pipe member 16 are long cylindrical members that extend in the axial direction (left-right direction in FIGS. 1 and 2). The D-side pipe member 14 corresponds to an outer pipe member, and the P-side pipe member 16 corresponds to an inner pipe member. In FIG. 1 and FIG. 2, the D-side pipe member 14 is shown in sand for easy understanding of the positions of the D-side pipe member 14 and the P-side pipe member 16. The D-side pipe member 14 and the P-side pipe member 16 are made of a metal having high electrical conductivity such as an aluminum alloy. For example, the D-side pipe member 14 and the P-side pipe member 16 are preferably formed of a 6063 material suitable for extrusion molding among aluminum alloys.

  One end (left end) in the axial direction of the P-side pipe member 16 is intubated inside the other axial end (right end) of the D-side pipe member 14, and is caulked and fixed together with the cowl brace 26 by electromagnetic forming. In the present embodiment, the D-side pipe member 14 has a larger outer diameter and inner diameter than the P-side pipe member 16 in portions other than the intubation portions of the D-side pipe member 14 and the P-side pipe member 16.

  Note that the thickness dP of the P-side pipe member 16 is preferably smaller than the thickness dD of the D-side pipe member 14. As a result, as described later, the diameter of the P-side pipe member 16 is increased by electromagnetic force generated by pulse energization of the electromagnetic coil 42 disposed inside the P-side pipe member 16 at the fixed position of the D-side pipe member 14 and the cowl brace 26. Thus, it becomes easy to caulk and fix to the D-side pipe member 14. Specifically, the ratio dP / dD of the thickness dP of the P-side pipe member 16 to the thickness dD of the D-side pipe member 14 is preferably 0.6 to 0.8.

  The D-side extension 20 is fixed to the outside of the end portion on the one side that is the driver's seat side in the pipe 12. The P-side extension 27 is fixed to the outside of the other end of the pipe 12 on the passenger seat side. The D-side and P-side extensions 20, 27 are fixed to a vehicle body frame (not shown) by fastening members such as bolts and nuts. The outer bracket 28 on the D side is fixed outside the pipe 12 so as to be adjacent to the other axial side of the D side extension 20 (the right side in FIGS. 1 and 2). The outer bracket 29 on the P side is fixed outside the pipe 12 so as to be adjacent to one side in the axial direction of the P side extension 27 (left side in FIGS. 1 and 2).

  The D-side extension 20, the steering support 22, the cowl brace 26, the P-side extension 27, and the two outer brackets 28 and 29 each have a circular through-hole through which the pipe 12 is inserted. For example, the cowl brace 26 includes a through hole 26a that allows the D-side pipe member 14 to pass through at a portion near one end in the longitudinal direction (portion near the right end in FIG. 1). By applying electromagnetic forming through the D-side pipe member 14 or the P-side pipe member 16 to the through hole, the D-side extension 20, the steering support 22, the cowl brace 26, and the P-side are applied to the D-side pipe member 14 or the P-side pipe member 16. The extension 27 and the two outer brackets 28 and 29 are fixed by caulking.

  For example, the steering support 22 is fixed to the intermediate portion in the axial direction of the D-side pipe member 14. The steering support 22 includes a main body portion 23 and two leg portions 24 and 25 connected to be branched to the main body portion 23, and the leg portions 24 and 25 are fixed to the D-side pipe member 14.

  A steering column (not shown) for supporting the steering shaft is fixed to the steering support 22. The cowl brace 26 is connected to a member (not shown) disposed inside the instrument panel. The lower end of the floor brace 52 is connected to a floor panel (not shown).

  In addition, a floor brace 52 and a plurality of intermediate brackets 53, 54, and 55 are fixed to the part of the circumferential direction at a plurality of longitudinal positions of the pipe 12 by welding. Thereby, the pipe 10 with a to-be-fixed member is formed.

  Next, the manufacturing method of the pipe 10 with a to-be-fixed member is demonstrated. In the present embodiment, an example will be described in which the D-side extension 20 is caulked and fixed to the D-side pipe member 14 by applying electromagnetic molding. Similarly, electromagnetic molding can be applied to the steering support 22, the cowl brace 26, the P-side extension 27, and the two outer brackets 28 and 29.

  Hereinafter, the electromagnetic forming method will be described with reference to FIGS. 3 and 4. 3 is an enlarged cross-sectional view taken along the line AA in FIG. FIG. 4 is a view corresponding to FIG. 3 in a state before energization of the electromagnetic coil (electromagnetic forming coil) 42.

  The electromagnetic forming apparatus 38 used for forming the pipe 10 with the fixed member includes a shaft member 40 inserted inward from one axial end side that is the driver seat side of the pipe 12. The shaft member 40 is formed into a long cylindrical shaft shape with resin, and an electromagnetic coil 42 is provided there. The electromagnetic coil 42 may cover the outer peripheral surface with resin or the like. The electromagnetic coil 42 is formed by winding a conductor wire a plurality of times along the axial direction of the shaft member 40.

  The shaft member 40 is disposed inside the D-side pipe member 14. That is, the outer diameter of the shaft member 40 is configured to be smaller than the inner diameter of the D-side pipe member 14. Further, as shown in FIG. 4, the shaft member 40 is disposed so that the electromagnetic coil 42 extends over the entire axial direction of the D-side extension 20 that is a fixed member and further protrudes from both ends of the D-side extension 20. .

  The electromagnetic forming device 38 is configured to be supplied with a pulse current from a power supply unit (not shown). The power supply unit supplies power to the electromagnetic coil 42 and includes a DC high-voltage power supply such as a battery and a capacitor. A large pulse current is applied to the electromagnetic coil 42 by instantaneously discharging the electric power charged in the capacitor. The power source unit may be configured such that the DC high-voltage power source includes an AC / DC conversion unit that converts AC power supplied from a commercial AC power source into DC current.

  As shown in FIG. 4, the D-side pipe member 14 is passed through the through hole of the D-side extension 20 that is a member to be fixed, and the D-side extension 20 is disposed at a desired fixing position in the D-side pipe member 14.

  In the present embodiment, the mold retainer 44 is used when performing electromagnetic molding. The mold retainer 44 is disposed around the fixed member and is used for suppressing deformation of the member due to electromagnetic forming. In the present embodiment, the mold restrainer 44 prevents the diameter of the D-side pipe member 14 from being expanded by electromagnetic molding at a position that is a distance L from the end of the D-side extension 20 that is a fixed member. Provided for. The distance L may be appropriately set according to the material, thickness, diameter, and the like of the D-side pipe member 14.

  For example, as shown in FIG. The mold retainer 44 has a configuration in which a first member 46 a and a second member 46 b that are cylindrical when combined are connected by a hinge 45. By disposing the clamp at the desired position of the D-side pipe member 14 and tightening the clamp with a fixing portion 47 such as a screw, the inner peripheral surface X of the die pressing member 44 becomes the outer peripheral surface of the D-side pipe member 14. Fix in close contact with.

  In such a state, by energizing the electromagnetic coil 42 with a pulse, the diameter of the portion of the D-side pipe member 14 that overlaps the electromagnetic coil 42 is expanded by electromagnetic force. As a result, as shown in FIG. 3, the diameters of the regions (region Y and region Z in FIG. 3) on both sides of the D-side extension 20 in the D-side pipe member 14 are expanded, and the D-side extension 20 becomes the D-side pipe member. 14 is fixed by caulking.

  At this time, by restricting the region in which the diameter is expanded by using the mold restrainer 44, the expansion of the diameter in the restricted region can be made steep. That is, when the mold retainer 44 is not used, as shown by a broken line in FIG. 3, the expansion region of the diameter of the D-side pipe member 14 around the D-side extension 20 is widened, and the bulge in the vicinity of the D-side extension 20 is gentle. Become. In contrast, when the mold retainer 44 is used, the bulge in the vicinity of the D-side extension 20 becomes sharper than when the mold retainer 44 is not used, and the D-side extension 20 is strengthened by the D-side pipe member 14. Can be fixed to.

  Further, when the member is to be fixed with the same strength in the case where the mold retainer 44 is not used and in the case where the mold retainer 44 is used, the voltage applied to the electromagnetic coil 42 is reduced in the case where the member is used compared to the case where the mold retainer 44 is not used. be able to. As described above, by limiting the region in which the diameter is expanded by using the mold suppressor 44, the applied voltage applied to the electromagnetic coil 42 can be reduced, and the life of the electromagnetic coil 42 can be extended.

  The electromagnetic molding can be similarly applied to members other than the D-side extension 20, that is, the steering support 22, the cowl brace 26, the P-side extension 27, and the two outer brackets 28 and 29. For example, the electromagnetic coils 42 are arranged side by side at positions where the D-side extension 20, the steering support 22, the cowl brace 26, the P-side extension 27, and the two outer brackets 28 and 29 are fixed, and the electromagnetic coils 42 are arranged in an appropriate order. On the other hand, an electromagnetic forming process may be performed by supplying a pulse current. Further, the electromagnetic forming process may be performed by simultaneously supplying a pulse current to the plurality of electromagnetic coils 42.

  Further, the electromagnetic forming device 38 may include an axis moving unit (not shown) that moves the shaft member 40 in the axial direction of the D-side pipe member 14 and the P-side pipe member 16. In this case, while the shaft member 40 is moved in the axial direction, electromagnetic molding processing is performed in an appropriate order on the D-side extension 20, the steering support 22, the cowl brace 26, the P-side extension 27, and the two outer brackets 28 and 29. You may make it give.

  In the portion where the D-side pipe member 14 and the P-side pipe member 16 are overlapped, the diameter of the D-side pipe member 14 is expanded by the force applied to the D-side pipe member 14 when the P-side pipe member 16 expands in diameter. The At this time, the electromagnetic coil 42 is arranged inside the D-side pipe member 14 via the P-side pipe member 16, but the magnetic force by the electromagnetic coil 42 is shielded by the P-side pipe member 16, and the D-side pipe member No induced current is generated in 14. For this reason, the D-side pipe member 14 does not have a force for expanding itself, but the diameter of the D-side pipe member 14 is expanded as the P-side pipe member 16 is expanded.

  Further, the electromagnetic forming device 38 may include a coil cooling system. For example, the coil cooling system may be configured to allow the shaft member 40 to pass through a cooling unit to which a coolant such as cooling oil or cooling water is supplied. Thereby, the electromagnetic coil 42 fixed to the shaft member 40 can be cooled.

  10 pipe with fixed member, 12 pipe, 14 D side pipe member, 16 P side pipe member, 20 D side extension, 22 steering support, 23 body part, 24, 25 legs, 26 cowl brace, 26a through hole, 27 P-side extension, 28, 29 Outer bracket, 38 Electromagnetic molding device, 40 Shaft member, 42 Electromagnetic coil, 44 type clamp, 45 Hinge, 46a First member, 46b Second member, 47 Fixing part, 52 Floor brace, 53 , 54, 55 Intermediate bracket.

Claims (1)

An electromagnetic molding method for expanding a diameter of a hollow member using an electromagnetic molding coil and fixing a fixed member disposed outside the hollow member,
An electromagnetic molding method, wherein a diameter of the hollow material is expanded in a state in which a mold holding member that suppresses expansion of the hollow material is disposed around the expanded region.