Twist bending processing method and twist bending processing device

Abstract

To bring a width of offset close to a width of a band plate through twist bending processing in response to a harsh molding request for plastically deformable band plates such as busbars.SOLUTION: A band plate X extends in a rod-like manner in a radial direction from a center of a circular cross-section of a penetration part 15 in a holding block 11 which rotatably supports holding members 17, 17. In such a state that the band plate X is supported, when pressing down a shaft 21 linked to the holding members 17 as shown as an arrow, even though twisting moment that rotates around an axis is applied to the band plate X, a rotation axial center at this time is a center of a through-hole 15. When paying attention to the band plate X, the rotation center is not a centerline (L) of the center in the width direction of the band plate X but becomes one end side in the width direction, and flange-like bending is performed. When the band plate X is viewed from a direction perpendicular to the longitudinal direction, the band plate rises such that the plate thickness surface Xb of the band plate X is rotated and becomes an "L" shape. Consequently, a width (w) of offset extends close to the width of the band plate X.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a torsional bending method for a plastically workable strip plate and a torsional bending apparatus used for carrying out the torsional bending method. [Background technology]

[0002] Busbars (copper sheets), a typical example of strips that can be plastically processed, are conductors used in areas where large amounts of current flow, and have traditionally been widely used in control panels, switchboards, batteries, etc. Recently, with the spread of electric vehicles, bus bars have been attracting attention as a replacement for high-voltage harnesses, which are the mainstream for electrical wiring. Unlike high-voltage harnesses, bus bars have a fixed shape and must be preformed into a specified shape. However, with vehicle space being limited due to the installation of large-capacity batteries and the like, the requirements for three-dimensional molding are becoming increasingly stringent in order to create space for the placement of other electrical components and to enable the bus bars to pass through narrow gaps. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-75310 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional twist bending process using a forming machine as described in Patent Document 1, for example, the center line (L) of the strip becomes the axis of rotation as shown in Fig. 9(1), so the side perpendicular to the length direction becomes "+" shaped as shown in the side image of Fig. 9(2). In other words, the width (w) of the offset formed by the twist bending process is at most about half the width of the strip.

[0005] The present invention has been made in consideration of the above-mentioned problems in the conventional art, and has an object to provide a new and useful torsional bending method that can bring the offset width close to the width of a plastically workable strip such as a bus bar by torsional bending, and a torsional bending apparatus used for carrying out the torsional bending method. A further object of the present invention is to provide a twisted body obtained by carrying out the torsional bending method. [Means for solving the problem]

[0006] The present invention has been made to solve the above-mentioned problems, and is a torsional bending method characterized by supporting a plastically processable strip plate in an aligned position with gaps in the longitudinal direction, and bending the middle portion of the strip plate by applying a torsional moment with a position on one end side in the width direction as the central axis, thereby bending the middle portion of the strip plate. The resulting twisted body has a characteristic curled-over twisted appearance.

[0007] The torsional bending method of the present invention can be carried out using a torsional bending device comprising a pair of support means for supporting a strip in the longitudinal direction with a gap therebetween and aligned in the same direction, a wrapping means for wrapping the middle portion of the strip between the pair of support means, a holding means for holding the wrapping means rotatably around an axis, and a rotating means for rotating the wrapping means around an axis, and is characterized in that, in the wrapped state, the width direction of the strip is aligned in the rotational radial direction of the wrapping means and the width direction center of the strip is located at a position offset from the rotation axis.

[0008] In this twisting and bending apparatus, in the wrapped state, the band is preferably set in a state in which one end in the width direction of the band is aligned with the rotation axis of the wrapping means. Preferably, the rotating means comprises a shaft attached to the holding means and extending radially outwardly therefrom. Preferably, the holding means is provided with a mounting portion for the shaft, and the shaft is detachable. Preferably, the holding means is composed of a pair of half-shaped members, and the clamping surfaces of the half-shaped members are tapered at both ends in the direction of the rotation axis to form a gap around the clamped strip. Effect of the Invention

[0009] According to the torsion bending method of the present invention, the offset width can be made close to the width of the strip. Also, the torsion bending device capable of carrying out the torsion bending method can be constructed with a simple structure and good durability. And, the offset width of the twisted body is close to the width of the strip as desired. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view of a torsion bending apparatus according to an embodiment of the present invention and a strip plate set in the apparatus in a state prior to torsion bending; [Diagram 2] FIG. 2 is a perspective view of the wrapped state of FIG. 1. [Diagram 3] 2 is a top view, a front view, and an AA cross-sectional view of the twisting and bending apparatus of FIG. 1. [Figure 4] FIG. 2 is a perspective view of the state after the torsional bending process of FIG. 1. [Diagram 5] FIG. 5 is a perspective view of the wrapped state of FIG. 4. [Figure 6] 5 is a top view, a front view, and an AA cross-sectional view of the twisting and bending apparatus of FIG. 4. [Figure 7] 2A and 2B are a perspective view and an image side view of a strip plate before and after torsion bending performed using the torsion bending apparatus of FIG. 1. [Figure 8] 1. FIG. 4 is a perspective view of another example of a strip plate after torsion bending processing carried out using the torsion bending processing apparatus of FIG. [Figure 9] 1A and 1B are a perspective view and a side image diagram of a strip plate produced by a conventional torsion bending method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A twisting and bending apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings. This twisting and bending device 1 is intended to process a copper plate intended for use as a bus bar into a strip X capable of being plastically processed, and has a structure shown in Figs. 1 to 6. For ease of explanation, the directions indicated by the arrows in FIG. 1 are defined as front-rear, left-right, up-down and up-down directions.

[0012] A pair of support parts 3, 3 is provided as a support means. The support part 3 has a rectangular shape, and its six outer faces face in the front-rear, left-right, up-down and up-down directions. The support part 3 is composed of a rectangular main body block 5 and a flat cover plate 7 located in front of it, and a slit 9 is provided on the front side of the main body block 5. The slit 9 is a thin rectangular flat plate, and extends from the front to the rear at a vertically intermediate position with the plate surface parallel to the top and bottom faces of the main body block 5. The slits are also located symmetrically in the left-right direction. The bottom of the slit 9 reaches a position approximately halfway along the front-rear length of the main body block 5. The slit 9 is open at the front and at both the left and right sides.

[0013] The slit 9 is a portion into which the strip X is fitted so as to be able to pass through, and the cross-sectional size perpendicular to the left-right direction is set slightly larger than the cross-sectional size of the strip X perpendicular to the longitudinal direction. The main body block 5 is covered with a cover plate 7. The cover 7 closes the front opening of the slit 9, and supports the fitted strip X while surrounding it from the front, back, top and bottom directions. The main body block 5 and the cover 7 are fixed together by bolt and nut fastening.

[0014] The pair of support parts 3, 3 are aligned in the front-rear and up-down directions and arranged with a gap in the left-right direction, and are fixed to the installation side of the device to maintain their relative positions. Therefore, the strip X is supported by the pair of supports 3, 3 with the respective strip surfaces Xa, Xa facing up and down, and the flat state shown in Fig. 7(1) is secured. This position is maintained without being dislodged.

[0015] A holding block 11 is disposed between a pair of support parts 3, 3 as holding means. This holding block 11 has a rectangular outer shape, with its six outer faces facing the front-rear, left-right, top-bottom directions. A recess 13 is provided on the upper side. The recess 13 is a thick rectangular flat plate, and extends downward from the top surface at a position midway between the left and right sides with the plate surface parallel to the left and right sides of the holding block 11. The recess 13 is also located symmetrically in the front-rear direction. The bottom of the recess 13 reaches a position approximately 2 / 3 of the length of the holding block 11 in the top-bottom direction. The recess 13 is open on the top and on both the front and rear sides.

[0016] The left and right sides of the holding block 11 are the rising blocks 11a, 11a, which face each other across the recess 13, and each has a through-hole 15. The through-hole 15 has a nearly circular cross section, penetrates the thickness of the rising block 11a in a straight line in the left-right direction, and is cylindrical as a whole. The axis of the through-hole 15 is located approximately in the center of the rising block 11a. The holding block 11 is fixed to the installation side of the device to maintain the positional relationship.

[0017] A pair of holding members 17, 17 are fitted into the holding block 11 as means for holding the strip X. As shown in FIG. 2, the holding member 17 has a shape like a cylinder cut in half, and the outer surface 17a is a substantially arcuate circumferential surface. The circumferential middle of the outer surface 17a is a flat surface parallel to the axial direction of the arcuate circumferential surface, which is a mounting surface 17a(s) described later. The inner surface 17b, which is the inner clamping surface, is a flat surface parallel to the axial direction of the arcuate circumferential surface. At both ends in the length direction, the inner surfaces 17c, 17c are smoothly connected to the inner surface 17b. The inner surface 17c is a curved tapered surface that bulges in an oblique direction, and the closer it is to the end surface 17d, the closer it is to the outer surface 17a. Therefore, when the pair of holding members 17, 17 are fitted together as described later, a triangular gap is formed in the direction shown in FIG. 3(2). A screw hole 19 is formed in the mounting surface 17a(s) of the outer surface 17a of the holding member 17. The axial direction of this screw hole 19 is approximately the same as the radial direction of the arc that forms the outer surface 17a. The bottom of the screw hole 19 does not reach the inner surface 17b, but is closed just before that.

[0018] The pair of holding members 17, 17 are arranged so that their respective inner surfaces 17b, 17c face each other with the plate surface Xa, Xa of the strip X sandwiched therebetween. The front plate thickness surface Xb of the strip X fits as close as possible to the edge of the holding members 17, 17, and the pair of holding members 17, 17, with the strip X sandwiched between them as a spacer, form a cylindrical shape with a substantially circular cross section perpendicular to the length direction. The outer peripheral surface is slightly smaller than the hole peripheral surface of the through hole 15. The radius of curvature of the outer surface 17a is substantially the same as the radius of curvature of the through hole 15.

[0019] With the strip X sandwiched in this state, both longitudinal ends of the pair of holding members 17, 17 are rotatably fitted into the rising blocks 11a, 11a, respectively. Therefore, the pair of holding members 17, 17 are rotatable about the axis integrally with the strip X. The length of the holding member 17 is approximately the same as the length of the holding block 11, and the axial end of the holding member 17 is fitted into the holding block 11 so as to be approximately flush with the outer surface in the left-right direction. Before processing, the holding members 17, 17 hold the strip X in the above-mentioned position with the plate surfaces Xa, Xa facing the vertical direction, so that the inner surfaces 17b, 17b of the pair of holding members 17, 17 face each other with a gap between them at the top and bottom in a position that receives the extended portion of the strip X supported by the supporting parts 3, 3 in that position. Therefore, the strip X is lifted and supported at three points with the plate surfaces Xa, Xa facing the vertical direction.

[0020] The intermediate portions of the pair of holding members 17 , 17 in which the screw holes 19 , 19 are formed are exposed from the recess 13 . Further, the plate thickness surfaces Xb, Xb of the strip X are exposed between the holding members 17, 17. As described above, the strip X is sandwiched in a state where it is brought close to the edge, and the rear plate thickness surface Xb is located on the widthwise center side of the inner surface 17b of the holding member 17.

[0021] The plate thickness surface Xb is slightly beyond the center of rotation when the pair of holding members 17, 17 rotates around the axis together with the band X as described above, and in the direction shown in Fig. 3 (3), the band X appears to extend in a rod-like shape in the radial direction from the center of rotation. That is, the width direction of the band X is aligned with the radial direction of rotation of the holding members 17, 17, and one side of a square area surrounding the center of rotation of the holding members 17, 17 becomes the plate thickness surface Xb. Therefore, when viewed from the strip X, one end in the width direction is aligned with the center of rotation, and the strip X is set with its width direction center located at a position offset from the axis of rotation.

[0022] A screw shaft 23 provided at the base end of a shaft 21 is screwed into one of the screw holes 19. The shaft 21 protrudes outward through a gap in the recess 13 of the holding block 11, and by moving the shaft 21 as an arm, the pair of holding members 17, 17 can be rotated around the same axis as the strip X. The screw hole 19 and the shaft 21 with the screw shaft 23 that screws into it constitute a manually operated rotating means.

[0023] The twisting and bending device 1 is configured as described above, and as shown in Figures 1 to 3, when the shaft 21 connected to the holding member 17 is pushed down as indicated by the arrow while the strip X is supported, the pair of supporting members 17, 17 rotates 90° around the axis together with the strip X sandwiched between them. The axis of rotation at this time is the center of the through hole 15. This rotation applies a torsional moment to the strip X, which causes it to be torsionally bent, but the neutral axis of this torsional moment is not on the center line (L) of the strip X in the width direction, but on one end side in the width direction, which is the axis of rotation. In the case of the rod-shaped strip X seen in the direction shown in FIG. 3(3), this is the point located at the center of the circular cross section of the penetration portion 15. Therefore, the band plate X is bent as shown in Figs. At this time, since the inner surface 17c is formed in the packaging member 17, the strip X rises while smoothly curving along the inner surface 17c without any difficulty.

[0024] As shown in Fig. 7, the strip X rises along one end in the width direction, not on an extension of the center line (L), so when viewed from a direction perpendicular to the length direction, the strip X rises as if the thickness surface Xb of the strip X has rotated, forming a twisted body in the shape of a bent "L". In other words, the offset width (w) expands to nearly the width of the strip X. This increased offset can be used to provide space for arranging other electrical components, etc.

[0025] The shaft 21 can also be pushed down from the opposite direction to that shown in Figures 1 and 2. Therefore, the offset direction can be selected from two directions. Moreover, by adjusting the distance between the support parts 3, 3, the range in which the torsional moment is applied can be adjusted.

[0026] As shown in Figure 8, it is possible to simply bend the middle part of the strip X in the longitudinal direction and then twist and bend both the left and right sides of the strip X into a U-shape. When twisted and bent in two places like this, the connecting part x2 is twisted relative to the pair of legs x1, x1 of the U-shape and stands up like a wall, making it possible to pass the strip through a narrow gap using the connecting part x2.

[0027] Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and the invention also includes design changes within the scope of the present invention without departing from the gist of the present invention. For example, the shaft 21 is attached to the holding member 17 in a positional relationship perpendicular to the plate surface Xa on the edge side of the strip X, but as long as the movement of the shaft 21 is ensured, there is no limitation to this positional relationship. As long as the collar bending can be performed on the strip X, including the configuration of the support part 3, there is no limitation, and the optimal design will be made each time depending on the type of material of the strip X, the size, the state of torsional bending, etc. [Explanation of symbols]

[0028] 1...Twisting and bending processing device 3...Support part 5...Main body block 7...Cover plate 9...Slit 11...Retaining block 11a... rising block 13... recess 15... through-hole 17: Supporting member 17a: Outer surface 17a(s): Mounting surface 17b...Inner surface (flat surface) 17c...Inner surface (curved tapered surface) 17d... end face 19... screw hole 21... shaft 23...Screw shaft X…Strip plate Xa…Plate surface Xb…Plate thickness surface x1…leg part x2…connection part L…Center line w…Offset width

Claims

1. This torsional bending method is characterized in that a plastically processable strip is supported in an aligned direction with gaps in the longitudinal direction, and a torsional moment is applied to the middle portion of the strip, with a position on one end side in the width direction as the central axis, thereby bending the middle portion of the strip.

2. A torsion bending apparatus capable of carrying out the torsion bending method according to claim 1, The apparatus includes a pair of support means for supporting the band plate in the same direction while being spaced apart in the longitudinal direction, a holding means for holding a middle portion of the band plate between the pair of support means, a holding means for holding the holding means rotatably around an axis, and a rotating means for rotating the holding means around the axis, This twisting and bending processing device is characterized in that, in the holding state, the width direction of the strip is aligned in the rotational radial direction of the holding means, and the width direction center of the strip is located at a position offset from the rotation axis.

3. In the twisting and bending apparatus according to claim 2, In the holding state, the twisting and bending apparatus is set in a state in which one end of the strip in the width direction is aligned with the rotation axis of the holding means.

4. In the twisting and bending apparatus according to claim 2 or 3, A twisting and bending apparatus, wherein the rotating means is constituted by a shaft attached to the holding means and extending radially outwardly of the rotating means.

5. In the twisting and bending apparatus according to claim 4, A twisting and bending processing device, characterized in that a shaft attachment portion is provided on the holding means side, and the shaft is detachable.

6. In the twisting and bending apparatus according to claim 2 or 3, The holding means is composed of a pair of half-shaped members, and the clamping surfaces of the half-shaped members are tapered at both ends in the direction of the rotation axis to form a gap around the clamped strip.

7. A collar-bent twisted body obtained by the method of twisting according to claim 1.

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