JP2012071321A - Method and device for manufacturing bus bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for manufacturing a bus bar, which secures shape accuracy while enhancing a yield.SOLUTION: The manufacturing method manufactures a bus bar 10 having a bolt hole 14 by processing a metal strip 20 by a longitudinally chained progressive processing. The manufacturing method includes: a prepared hole forming step of forming a prepared hole 24 that is finally formed into the bolt hole 14 so that whose length X2 in a first direction, which passes through a hole center thereof and is parallel to a longitudinal direction of the bus bar 10, is controlled equal to a diameter D2 of the bolt hole 14 and also whose length Y2 in a second direction, which passes through the hole center and is perpendicular to the first direction, is controlled smaller than the diameter D2 of the bolt hole 14; and a bolt hole forming step of forming the bolt hole 14 by inserting a taper pin 44 of which the largest diameter is larger than the length Y2 in the second direction and is equal to or smaller than the length X2 in the first direction, into the prepared hole 24 formed in the prepared hole forming step so that the prepared hole 24 is extended in the second direction without extended in the first direction.

Description

  The present invention relates to a bus bar manufacturing method and a manufacturing apparatus for electrically connecting electrical components. More specifically, the present invention relates to a bus bar manufacturing method and a manufacturing apparatus in which bolt holes are formed.

  Various electrical components used for the inverter and the like are electrically connected by a bus bar. The bus bar is manufactured by progressive press processing by a known press using a progressive die. In other words, the band-shaped conductive metal plate is fed into the mold in which a plurality of punching steps are arranged in order at a predetermined pitch, by a predetermined pitch by a feeding device, so that the press work is performed step by step in the mold, The press-finished products that finally become connection terminals are sequentially discharged and manufactured (see Patent Document 1). In this progressive pressing, the flat plate after punching becomes a waste material, so the yield is poor.

  Therefore, in order to improve the yield, the bus bar can also be manufactured by a longitudinal chain type progressive process (see Patent Document 2). In this case, the bus bar is formed by stamping, pressing, or the like from a metal strip, but the individual bus bars are processed in a state where the front end and the rear end are connected to each other without being cut off during the processing. And it cut | disconnects simultaneously with final processing, and it isolate | separates from a metal strip, and manufactures a bus bar.

  Such a bus bar is provided with a bolt hole through which a bolt or the like for fixing to an electrical component is inserted. And when manufacturing the bus bar in which the bolt hole is formed, the bolt hole is formed by the punching process in any of the progressive press process or the longitudinal chain type progressive process (see Patent Document 3). .

JP 2009-245824 A Japanese Utility Model Publication No. 62-173192 JP-A-11-111355

  However, if the bolt holes are formed by punching as described above, waste material is produced after the punching, and it is difficult to improve the yield. Therefore, in order to improve the yield, it is conceivable to form a bolt hole by providing a hole smaller than the bolt hole and then expanding the hole with a punch.

However, if the bolt hole is formed by expanding the diameter by punching in the longitudinal chain type progressive feeding, it becomes impossible to ensure the shape accuracy of the bus bar. This is because the dimensional error of the bus bar gradually increases in the bus bar feeding direction due to the diameter expansion by the punch.
In addition, even in the case of longitudinal chain type progressive feed processing, if a bolt seat formed around the bolt hole that is larger than the width of the bus bar (metal strip) is required, the metal strip is formed at a portion other than the bolt seat. Is punched into the width dimension of the bus bar, and there is also a problem that the yield is deteriorated.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a bus bar manufacturing method and a manufacturing apparatus capable of ensuring shape accuracy while improving yield.

  One aspect of the present invention made to solve the above problems is a bus bar manufacturing method for manufacturing a bus bar having a bolt hole by subjecting a metal strip to a longitudinal chain type progressive feed process, and finally becomes the bolt hole. The length of the lower hole in the second direction passing through the hole center and in the first direction parallel to the longitudinal direction of the bus bar is equal to the diameter of the bolt hole and passing through the hole center and perpendicular to the first direction. And a pilot hole forming step in which the diameter is smaller than the diameter of the bolt hole, and the maximum diameter of the pilot hole formed in the pilot hole forming step is larger than the length in the second direction and the first And a bolt hole forming step of forming the bolt hole by inserting a taper pin that is equal to or less than the length of the direction and expanding the pilot hole in the second direction without expanding in the first direction. It is characterized by

  In this bus bar manufacturing method, a pilot hole that finally becomes a bolt hole is formed in the pilot hole forming step. The formation of the pilot hole may be performed by punching. Thereafter, in the bolt hole forming step, the pilot hole is enlarged to form a bolt hole.

Here, since the pilot hole formed in the pilot hole forming step is smaller than the bolt hole, it is possible to reduce the amount of waste material as compared with the case where the bolt hole is formed by punching. Therefore, the yield can be improved.
Further, in the bolt hole forming step, since the prepared hole is expanded in the second direction without expanding in the first direction, the bus bar is not extended in the longitudinal direction (feeding direction) when the bolt hole is formed. Therefore, the shape accuracy of the bus bar can be ensured.

  In addition, what is inserted into the “bolt hole” is not limited to a bolt. For example, a terminal (battery electrode or the like) provided in an electrical component is inserted and a nut is fastened, and a bus bar is inserted into the electrical component (battery or the like). Sometimes fixed.

  In the bus bar manufacturing method described above, a bolt seat having a diameter larger than the width dimension of the metal strip may be formed around the bolt hole in the bolt hole forming step.

  Even in the case where such a bolt seat is formed, it is not necessary to punch out the metal strip to the width dimension of the bus bar at a portion other than the bolt seat, so that the waste material portion can be greatly reduced. Thus, even when a bolt seat that is larger than the bus bar width is required, the yield can be improved.

  Here, when the bolt seat having a diameter larger than the width dimension of the metal strip is formed, the bolt seat as described above may not be formed depending on the shape of the pilot hole formed in the pilot hole forming step. For example, when the prepared hole is elliptical, the bolt seat as described above may not be formed.

  Therefore, in the prepared hole forming step, the prepared hole may be formed in a shape that protrudes inward in the second direction.

  Thus, in the pilot hole forming step, by forming a pilot hole having a shape protruding inward in the second direction, a diameter larger than the width dimension of the metal strip in the bolt hole forming step. The bolt seat can be reliably formed.

  Moreover, when forming the said bolt seat in the said bolt hole formation process, you may shape | mold by pressing the outer edge of the protrusion part which protrudes from the said metal strip among the said bolt seat to a metal mold | die.

  In this manner, by forming the outer edge of the projecting portion of the bolt seat against the mold, a bolt seat having a desired diameter larger than the width of the metal strip can be reliably formed.

  What is necessary is just to implement the above-mentioned manufacturing method using the following manufacturing apparatuses. And such a manufacturing apparatus is a bus bar manufacturing apparatus that manufactures a bus bar having a bolt hole by subjecting a metal strip to a longitudinal chain-type progressive feed process. The length in the first direction parallel to the longitudinal direction of the bus bar is equal to the diameter of the bolt hole, and the length in the second direction passing through the hole center and orthogonal to the first direction is the diameter of the bolt hole. A lower hole forming mold formed to be smaller and a taper pin having a maximum diameter larger than the length in the second direction and less than or equal to the length in the first direction, and inserting the taper pin into the lower hole; Then, what is necessary is just to have the bolt hole formation metal mold | die which forms the said bolt hole by expanding the said lower hole to the said 2nd direction, without expanding to the said 1st direction.

  In the bus bar manufacturing apparatus, when the bolt hole forming die forms a bolt seat having a diameter larger than the width dimension of the metal strip around the bolt hole, the bolt hole forming die protrudes from the metal strip of the bolt seat. You may have a metal mold | die which shape | molds the protrusion part to make into a predetermined shape.

  According to the bus bar manufacturing method and manufacturing apparatus according to the present invention, as described above, the shape accuracy can be ensured while improving the yield.

It is a figure which shows schematic structure of the bus bar manufactured by the manufacturing method which concerns on embodiment. It is a top view of the bus bar shown in FIG. It is a figure explaining the outline of the manufacturing process of a bus bar. It is a figure which shows the metal strip in which the pilot hole was formed in the pilot hole formation process. It is a figure which shows schematic structure of a pilot hole formation metal mold | die. It is a figure which shows schematic structure of a bolt hole formation metal mold | die. It is a figure which shows the state before inserting a taper pin in a prepared hole. It is a figure which shows the state which inserts the taper pin in a lower hole and forms the bolt hole. It is a figure which shows the state in which the bolt hole was formed. It is the figure which looked at the upper mold | type provided with the bolt seat shaping | molding die from the downward direction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a bus bar manufacturing method and a manufacturing apparatus having a bolt hole according to the present invention will be described below in detail with reference to the drawings.
Therefore, the bus bar manufactured by the manufacturing method according to the present embodiment will be described with reference to FIGS. FIG. 1 is a diagram illustrating a schematic configuration of a bus bar manufactured by the manufacturing method according to the embodiment. FIG. 2 is a plan view of the bus bar shown in FIG.

As shown in FIG. 1, the bus bar 10 is a wiring for electrically connecting electrical components. Bolt holes 12 and 14 are provided at both ends of the bus bar 10. A bolt seat 15 having a diameter larger than the width of the bus bar 10 is formed around the bolt hole 14. These bolt holes 12 and 14 are holes into which bolts for electrically connecting and fixing the bus bar 10 to electric parts are inserted. The bus bars 10 are connected and fixed to the electrical components by inserting the bolts into the bolt holes 12 and 14 and fastening the bolts to the screw holes provided on the electrical component side.
In addition, the bus bar 10 may be connected and fixed to the electrical component by inserting the terminal on the electrical component side into the bolt holes 12 and 14 and fastening the nut to the screw formed on the terminal.

  Further, the bus bar 10 is formed with a bent portion 11. That is, as shown in FIG. 2, the bus bar 10 is bent on the left side (bolt hole 12 side) in the lower side in the drawing and on the right side (bolt hole 14 side) in the upper side in the drawing. Such a plane bending process for the bus bar is performed in consideration of the arrangement space of the bus bar. Therefore, the plane bending process for the bus bar may not be performed.

  Such a bus bar 10 is manufactured by processing a conductive elongated metal plate (metal strip) 20 as shown in FIG. FIG. 3 is a diagram for explaining the outline of the bus bar manufacturing process. The bus bar 10 is manufactured by sequentially performing a plane bending process, a pilot hole forming process, a bolt hole forming process, and a cutting process.

  In the plane bending step, the bent portion 11 of the bus bar 10 is formed, and the metal strip 20 is bent on the plane. In this plane bending process, the metal strip 20 is constrained by the upper mold, and then a cam mold for forming the bent portion 11 is slid to push the metal strip 20 from both sides to perform bending. By this plane bending process, the bent portion 11 is formed in the metal strip 20. In addition, this plane bending process is not an essential process in the present invention.

  In the prepared hole forming step, prepared holes 22 and 24 to be the bolt holes 12 and 14 are formed. That is, the lower hole 24 is formed on the front end side of the bus bar 10 and the lower hole 22 is formed on the rear end side. These pilot holes 22 and 24 are formed by punching with a pilot hole forming mold 30. The lower holes 22 and 24 formed at this time are provided so that the long side is located in the feeding direction of the metal strip 20 (longitudinal direction of the bus bar). As shown in FIG. 4, the first direction lengths X1 and X2 of the lower holes 22 and 24 are equal to the diameters D1 and D2 of the bolt holes 12 and 14, respectively. On the other hand, the second direction lengths Y1, Y2 of the lower holes 22, 24 are smaller than the diameters D1, D2 of the bolt holes 12, 14. The first direction is a direction passing through the center of the lower hole and parallel to the longitudinal direction of the bus bar, and the second direction is a direction passing through the center of the lower hole and orthogonal to the first direction. The lower hole 22 has a rectangular shape, and the lower hole 24 has a drum shape with the long side protruding toward the inner side of the hole. In addition, FIG. 4 is a figure which shows the metal strip in which the pilot hole was formed in the pilot hole formation process.

  The lower hole forming mold 30 for forming such lower holes 22 and 24 includes an upper mold 31 and a lower mold 32 as shown in FIG. FIG. 5 is a diagram showing a schematic configuration of the pilot hole forming mold. The upper die 31 is provided with a convex portion 33 for punching the lower hole 22 and a convex portion 34 for punching the lower hole 24. In addition, the cross-sectional shape of the convex part 33 is a rectangle, and the cross-sectional shape of the convex part 34 is a drum shape. On the other hand, the lower mold 32 is provided with concave portions 35 and 36 corresponding to the convex portions 33 and 34. In the lower hole forming mold 30, the lower holes 22 and 24 are punched by lowering the upper mold 31 with respect to the metal strip 20 arranged at a predetermined position of the lower mold 32.

  In the bolt hole forming step, the bolt holes 12 and 14 are formed from the lower holes 22 and 24 as shown in FIG. That is, the lower hole 22 is expanded to form the bolt hole 12, and the lower hole 24 is expanded to form the bolt hole 14 having the bolt seat 15 larger than the width dimension of the metal strip 20.

  In the present embodiment, the bolt hole 12 is also formed by expanding the pilot hole after providing the lower hole in the same manner as the bolt hole 14, but the bolt hole 12 may be formed by punching. That is, in the case of the bolt hole 12 that does not have the bolt seat 15 such as the bolt hole 14, the above-described prepared hole forming step and the bolt hole forming step are not essential steps. In that case, what is necessary is just to make the shape of the convex part 33 in the lower hole formation metal mold 30 into the shape of the bolt hole 12.

  The bolt hole forming mold 40 for forming such bolt holes 12 and 14 includes an upper mold 41 and a lower mold 42 as shown in FIG. FIG. 6 is a diagram showing a schematic configuration of a bolt hole forming mold. The upper die 31 is provided with a taper pin 43 for forming the bolt hole 12 and a taper pin 44 for forming the bolt hole 14. The taper pins 43 and 44 are configured to move up and down separately from the upper die 41. The maximum diameter of the taper pin 43 is larger than the second direction length Y1 of the lower hole 22 and not more than the first direction length X1. The maximum diameter of the taper pin 44 is larger than the second direction length Y2 of the lower hole 24 and not more than the first direction length X2.

  On the other hand, the lower mold 42 is provided with slide molds 45 and 46 that move in response to the lowering of the taper pins 43 and 44. The slide dies 45 and 46 are a pair of split dies and are urged in the direction in which they abut. As a result, the slide molds 45 and 46 are configured such that each divided mold is in a separated state when the bolt hole is formed (the taper pin is in the lower mold) (see FIG. 8). When the bolt hole 12 is formed by punching, the taper pin 43 and the slide die 45 are not necessary.

In this bolt hole forming mold 40, the upper mold 41 is lowered with respect to the metal strip 20 arranged at a predetermined position of the lower mold 42, whereby the taper pin 43 is inserted into the lower hole 22 and the taper pin 44 is inserted into the lower hole 24. Then, the lower holes 22 and 24 are enlarged to form the bolt holes 12 and 14.
The formation of bolt holes by the bolt hole forming mold 40 will be described with reference to FIGS. FIG. 7 is a diagram illustrating a state before the taper pin is inserted into the prepared hole. FIG. 8 is a diagram showing a state in which a taper pin is inserted into the lower hole to form a bolt hole. FIG. 9 is a diagram illustrating a state in which a bolt hole is formed. In addition, since the bolt holes 12 and 14 are formed by the same method, only formation of the bolt hole 14 is demonstrated below.

  First, as shown in FIG. 7, the metal strip 20 is arranged so that the lower hole 24 is positioned at a predetermined position of the slide mold 46. At this time, the center of the lower hole 24 and the center of the taper pin 44 coincide. Then, the upper die 41 is lowered to hold the metal strip 20 with the slide die 46. In FIG. 7, the upper die 41 is omitted.

Next, the taper pin 44 is lowered and inserted into the prepared hole 24 as shown in FIG. At this time, the pair of split molds slide apart while the slide mold 46 is in contact with the outer periphery of the taper pin 44.
Since the diameter of the taper pin 44 is larger than the length Y2 of the lower hole 24 in the second direction, insertion of the taper pin 44 into the lower hole 24 causes the metal strip 20 to expand in the second direction of the lower hole 24. In addition, since the maximum diameter of the taper pin 44 is not more than the first direction length X2, the metal strip 20 is not expanded in the first direction of the lower hole 24. That is, the metal strip 20 (bus bar 10) is not stretched in the longitudinal direction (feed direction) when forming the bolt hole. Thereby, the shape accuracy of the bus bar 10 can be ensured.

  Here, since the lower hole 24 has a drum shape that protrudes inward of the hole, the bolt seat 15 having a diameter larger than the width dimension of the metal strip 20 can be reliably formed in the bolt hole forming step. . Since the bolt seat 15 is formed in this way, the width of the metal strip 20 is not required up to the diameter of the bolt seat 15, and the width of the bus bar 10 is sufficient. Thus, even when the bolt seat 15 is formed, it is not necessary to punch out the metal strip 20 in the width dimension of the bus bar 10 at a portion other than the bolt seat 15, so that the portion that becomes a waste material is greatly reduced. Can do. Therefore, even when a bolt seat that is larger than the width of the bus bar is required, the yield can be improved.

  In the present embodiment, the diameter of the bolt seat 15 is determined by the size of the convex portion formed in the lower hole 22. For this reason, the diameter of the bolt seat 15 may vary somewhat depending on conditions during the bolt hole forming process. Therefore, as shown in FIG. 10, a bolt seat mold 47 having an arc portion 47 a may be provided in the upper mold 41. FIG. 10 is a view of the upper mold provided with the bolt seat mold as viewed from below. By providing the bolt seat forming die 47, the outer edge 15a of the protruding portion protruding from the metal strip 20 of the bolt seat 15 is pressed against the arc portion 47a of the bolt seat forming die 47 when the bolt hole is formed. The bolt seat 15 is formed following the arc portion 47 a of the mold 47. As a result, the bolt seat 15 can be formed with a desired diameter larger than the width dimension of the metal strip 20.

  Thereafter, as shown in FIG. 9, the taper pin 44 and the upper die 41 are raised. At this time, as the taper pin 44 rises, the pair of slide dies 46 slide in directions close to each other and finally come into contact with each other. This completes the formation of the bolt holes 14. The bolt hole 12 is also formed at the same time. Thus, when the bolt hole forming step is completed, the shape of the bus bar 10 is completed at the leading portion of the metal strip 20 as shown in FIG.

  Finally, in the cutting step, the leading portion of the metal strip 20 in which the bolt holes 12 and 14 are formed is cut off from the metal strip 20 at a predetermined position. Thus, the bus bar 10 shown in FIGS. 1 and 2 is obtained. In the cutting process, bending may be performed as necessary. Thereby, the bus bar of arbitrary shapes can be manufactured.

  As described above, according to the bus bar manufacturing method and manufacturing apparatus according to the embodiment as described in detail, in the pilot hole forming step, the pilot hole 22 that finally becomes the bolt holes 12 and 14 by the pilot hole forming mold 30. , 24 are formed. Since the lower holes 22 and 24 formed at this time are smaller than the bolt holes 12 and 14, it is possible to reduce the amount of waste material compared to the case where the bolt holes are formed by punching, thereby improving the yield. Can do.

  In the bolt hole forming step, the lower holes 22 and 24 are enlarged by the bolt hole forming mold 40 to form the bolt holes 12 and 14. At this time, since the lower holes 22 and 24 are expanded in the second direction without expanding in the first direction, the metal strip 20 is not stretched in the longitudinal direction (feeding direction) when the bolt hole is formed. Therefore, the shape accuracy of the bus bar 10 can be ensured.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, rectangular holes and drum-shaped holes are exemplified as the holes formed in the hole forming step. However, the present invention is not limited to these shapes, and other shapes (for example, an elliptical shape) ) May be formed.

  In the above-described embodiment, the formation of the lower hole 22 (bolt hole 12) and the formation of the lower hole 24 (bolt hole 14) are performed at the same time.

10 Busbar 14 Bolt hole 15 Bolt seat 15a Outer edge 20 Metal strip 24 Lower hole 30 Lower hole forming die 31 Upper die 32 Lower die 34 Convex portion 36 Concave portion 40 Bolt hole forming die 41 Upper die 42 Lower die 44 Taper pin 47 Bolt seat Mold 47a Arc part

Claims (6)

In a bus bar manufacturing method for manufacturing a bus bar having a bolt hole by processing a metal strip in a longitudinal chain type,
The length of the pilot hole that finally becomes the bolt hole passes through the hole center in a first direction parallel to the longitudinal direction of the bus bar is equal to the diameter of the bolt hole, and passes through the hole center in the first direction. A pilot hole forming step in which the length in the second direction orthogonal to the diameter of the bolt hole is smaller than the diameter of the bolt hole;
A taper pin having a maximum diameter larger than the length in the second direction and not more than the length in the first direction is inserted into the pilot hole formed in the pilot hole forming step, and the pilot hole is inserted into the first hole. A bolt hole forming step of forming the bolt hole by expanding in the second direction without expanding in one direction;
A bus bar manufacturing method comprising: In the manufacturing method of the bus bar according to claim 1,
In the bolt hole forming step, a bolt seat having a diameter larger than the width dimension of the metal strip is formed around the bolt hole. In the bus bar manufacturing method according to claim 2,
The bus bar manufacturing method, wherein, in the lower hole forming step, the lower hole is formed in a shape protruding inward in the second direction. In the manufacturing method of the bus bar according to claim 2 or claim 3,
In the bolt hole forming step, when the bolt seat is formed, the outer edge of the protruding portion protruding from the metal strip in the bolt seat is pressed against a mold to form the bus bar. In a bus bar manufacturing apparatus that manufactures a bus bar having bolt holes by processing a metal strip in a longitudinal chain type,
The length of the pilot hole that finally becomes the bolt hole passes through the hole center in a first direction parallel to the longitudinal direction of the bus bar is equal to the diameter of the bolt hole, and passes through the hole center in the first direction. A lower hole forming mold formed so that the length in the second direction orthogonal to the diameter of the bolt hole is smaller than the diameter of the bolt hole;
A taper pin having a maximum diameter larger than the length in the second direction and less than or equal to the length in the first direction, inserting the taper pin into the lower hole, and expanding the lower hole in the first direction; A bolt hole forming mold for forming the bolt hole by expanding in the second direction without,
An apparatus for manufacturing a bus bar, comprising: In the bus bar manufacturing apparatus according to claim 5,
When forming a bolt seat having a diameter larger than the width dimension of the metal strip around the bolt hole, the bolt hole forming mold is formed with a protruding portion protruding from the metal strip in a predetermined shape. An apparatus for manufacturing a bus bar, comprising:

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