JP2018200848A - Bus bar, and production method therefor - Google Patents

Abstract

To provide a bus bar capable of improving durability of an insulating coating.SOLUTION: Both side faces 24 of a bus bar formed of a plate are positioned at each lateral side of a first plate surface 22a and a second plate surface 22b. A first round corner part 32a and a second round corner part 32b are formed so that each angle formed by crossing the plate surface and the side faces 24 is bent circularly. An insulating coating part 26 is formed within a prescribed range in the first plate surface 22a, the second plate surface 22b, and both side faces 24. Recesses 30 formed on the side faces 24 are formed so as to be recessed between the first round corner part 32a and the second round corner part 32b.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power distribution bus bar and a method for manufacturing the same.

  A bus bar is used to electrically connect various components. For example, in a bus bar used for a vehicle such as an electric vehicle, an insulating coating is formed on the bus bar in consideration of contact with an operator and contact with other components.

  Patent Document 1 discloses an electronic component package formed by half-punching from a metal plate. In the half punching process, the metal plate placed on the half punching hole of the die is pressed by the half punching punch, and a convex portion is formed on the metal plate so as to protrude into the half punching hole. Next, the convex part formed in the metal plate is punched in the direction opposite to the half-punching process, and the electronic component package is formed from the metal plate.

JP 2004-47750 A

  By the way, when an insulating film is formed on the bus bar, if there is a burr or a small step on the metal plate on which the insulating film is provided, there is a high possibility that the insulation film will break down. Therefore, it is preferable that the metal plate provided with the insulating coating is smooth. The electronic component package disclosed in Patent Document 1 may leave burrs or small steps on the side surface separated from the metal plate.

  This invention is made | formed in view of such a subject, The objective is to provide the bus-bar which improved the durability of the insulating film.

  In order to solve the above-described problems, an aspect of the present invention is a bus bar formed of a plate material, both side surfaces located on the sides of both plate surfaces, and each corner at which both plate surfaces and both side surfaces intersect. And a rounded corner portion formed by curving in a round shape, and an insulating coating portion formed in a predetermined range on both plate surfaces and both side surfaces. Both side surfaces have a recess formed in a recess between the round corners.

  Another aspect of the present invention is a method for manufacturing a bus bar. This manufacturing method consists of a half-punch process in which a plate material is pressed halfway in a plane direction to form a protruding part on the plate material, and a protruding part of the plate material is pressed in the reverse direction of the half-punch process to form a primary product of a bus bar. Punching process, a side pressing process for forming recesses that dent both side surfaces of the primary molded product, and an insulating forming process for forming an insulating film on the primary molded product so that the recessed portion extends. And having.

  ADVANTAGE OF THE INVENTION According to this invention, the bus bar which improved the durability of the insulating film can be provided.

It is a perspective view of the bus bar of an Example. It is a fragmentary perspective view of the bus-bar which expands and shows a part of recessed part. It is line segment AA sectional drawing of the bus bar shown in FIG. It is a figure which shows the manufacturing process of a bus bar. FIG. 5 is a diagram showing a manufacturing process of the bus bar, and is a diagram showing a continuation of the manufacturing process of the bus bar shown in FIG. 4. It is a figure which shows the cross section of the primary molded product which performed the side press process.

  FIG. 1 is a perspective view of a bus bar 10 according to the embodiment. The bus bar 10 is provided in the vehicle for power distribution, and electrically connects each component. For example, the bus bar 10 is used in a high voltage device such as an inverter or a battery of an electric vehicle or a hybrid vehicle, and a large current flows.

  The bus bar 10 is formed in various shapes depending on the arrangement of components to be electrically connected, and is not limited to the shape shown in FIG. 1, but is at least a plate shape because it is formed by punching a metal plate material. Manufacturing cost can be reduced by using an inexpensive metal plate.

  The bus bar 10 includes a pair of connecting end portions 20, an insulating coating portion 26, and a pair of concave portions 30. The connecting end 20 is located at both ends of the bus bar 10 and has holes that are fixed by bolts or the like. The insulating coating portion 26 is not formed on the connecting end portion 20, and the conductive portion 12 that is a metal material is exposed.

  The insulating coating portion 26 is formed on the surface of the conductive portion 12 except for the connecting end portions 20 at both ends of the bus bar 10. The insulating coating portion 26 is formed in a set range of the first plate surface 22 a and the second plate surface 22 b and both side surfaces 24. If an insulating film is formed on a burr or a small step, the burr or step locally becomes a high electric field at the time of power distribution, which may cause a dielectric breakdown and peel off the insulating film. In addition, if the insulating coating is formed thick in order to suppress dielectric breakdown, manufacturing costs are increased.

  Therefore, the bus bar 10 according to the embodiment can be smoothed by forming the recesses 30 on both side surfaces 24 and crushing burrs and steps generated when the metal plate material is punched. Thereby, durability of the insulating coating part 26 improves, and the insulating coating part 26 can be made thin and manufacturing cost can be suppressed.

  FIG. 2 is a partial perspective view of the bus bar 10 showing a part of the recess 30 in an enlarged manner. The coating boundary 28 at both ends of the insulating coating portion 26 overlaps the concave portion 30, and the concave portion 30 is formed in a range where the insulating coating portion 26 is set. That is, the recessed part 30 extends longer than the set range of the insulating coating part 26, and the insulating coating part 26 is provided in the range in which the recessed part 30 is formed. Thereby, the surface of the bus bar 10 in a range where the insulating coating portion 26 is formed can be smoothed.

  FIG. 3 is a cross-sectional view taken along line AA of the bus bar 10 shown in FIG. The concave portion 30 is curved so that the central portion of the side surface 24 is most concave, and the cross section is formed in an arc shape.

  The bus bar 10 has a corner where the first plate surface 22a and both side surfaces 24 intersect with each other, a first round corner portion 32a formed by rounding and a corner where the second plate surface 22b and both side surfaces 24 intersect with each other. And a second round corner portion 32b formed to be round and curved. By curving the corners of the bus bar 10 in a round shape, it is possible to reduce the possibility of the dielectric breakdown of the insulating coating portion 26 occurring. When the first plate surface 22a and the second plate surface 22b are not distinguished from each other, they are referred to as “both plate surfaces 22”. When the first round corner portion 32a and the second round corner portion 32b are not distinguished from each other, " The round corner portion 32 is located at the boundary between the both plate surfaces 22 and the side surface 24.

  The concave portion 30 is formed between the first round corner portion 32a and the second round corner portion 32b so as to leave the roundness of the first round corner portion 32a and the second round corner portion 32b. Thereby, the corner | angular side and the side surface 24 of the bus-bar 10 can be made smooth.

  FIG. 4 is a diagram illustrating a manufacturing process of the bus bar 10. FIG. 5 is a diagram showing a manufacturing process of the bus bar 10 and shows a continuation of the manufacturing process of the bus bar 10 shown in FIG. 4 and 5 is the same viewpoint as the cross section of the bus bar 10 shown in FIG. 3, and is a view seen along the longitudinal direction of the bus bar 10.

  As shown in FIG. 4A, a half punching process is performed in which the plate material 40 is placed on the die 44 and pressed by the punch 42. In the half blanking process, the width L1 of the punch 42 is larger than the width L2 of the hole of the die 44. The width L1 of the punch 42 is larger than the plate width of the bus bar 10, and the width L2 of the hole of the die 44 is the same as the plate width of the bus bar 10.

  In the half-punching process shown in FIG. 4B, a portion 46 protruding from the plate material 40 is formed by pressing the plate material 40 in the perpendicular direction to the middle of the plate thickness by the punch 42. In the half-punching process, the plate material 40 is not punched at a time but stopped halfway. For example, the half-punch amount by which the punch 42 presses the plate material 40 is set to fall within a distance 0.5 to 0.8 times the plate thickness T of the plate material 40. A first round corner portion 32a that is round and curved is formed by the half punching process.

  In the next punching step shown in FIG. 5A, the protruding portion 46 of the plate member 40 is pressed from the opposite direction to the half punching step. Thereby, the protruding portion 46 is separated, and the primary molded product 48 of the bus bar 10 is punched as shown in FIG. In the punching step, the primary molded product 48 may be taken out by punching out the portion 46 projected by the punch and die, instead of flat pressing.

  As shown in FIG. 5B, the second round corner portion 32b that is rounded and curved is formed by punching the primary molded product 48 by pressing in the direction opposite to the half-punching process. Thus, the round corner part 32 of the bus-bar 10 can be all rounded by combining the punching process punched in the reverse method and the half punching process.

  As shown in FIG. 5 (b), the primary molded product 48 of the bus bar 10 may have burrs or steps formed in the middle of the side surface 24, which is a location separated from the plate material 40. Therefore, in the side pressing step shown in FIG. 5C, both side surfaces of the primary molded product 48 are recessed to form the recesses 30.

  In the side pressing process, the pair of pressing portions 50 press the side surfaces of the primary molded product 48. The pressing surface 50a of the pressing unit 50 is curved in a semicylindrical shape.

  In the side pressing step, the curved portion 30 is formed by pressing in the plate width direction 52 while leaving the roundness of the first round corner portion 32a and the second round corner portion 32b. Thereby, the burr | flash and level | step difference which were formed in the side surface of the primary molded product 48 by the half punching process and the punching process can be made smooth, leaving the round corner part 32.

  After the lateral pressing process, an insulation forming process is performed in which an insulating film is formed on the surface of a predetermined range of the primary molded product 48. The insulating coating portion 26 is formed by, for example, being applied to a primary molded product 48 and dried, or formed by attaching an insulating tape such as an epoxy film or a polyimide film to the primary molded product 48. Note that the bus bar 10 may be bent after the insulation forming step according to the application.

  In this way, the plate material 40 is pressed to the middle of the plate thickness in the perpendicular direction to form a portion 46 protruding from the plate material 40, and the protruding portion 46 of the plate material 40 is pressed in the opposite direction of the half-punching step. Then, a punching process for punching the primary molded product 48 of the bus bar 10, a side pressing process for forming a recess 30 for recessing both side surfaces of the primary molded product 48, and a range in which the recess 30 extends. The bus bar 10 is manufactured by an insulation formation step of forming an insulation film on the primary molded product 48.

  FIG. 6 shows a cross section of the primary molded product 48 that has been subjected to the lateral pressing process. Concave portions 30 are formed on the side surface 24 of the primary molded product 48 by the side pressing process.

  The recess amount Q of the recess 30 is set to be larger than the difference between the width L1 of the punch 42 and the width L2 of the hole of the die 44 in the half punching process. This is because a step corresponding to the difference between the width L1 of the punch 42 and the width L2 of the hole of the die 44 may be formed on the side surface 24, so that the step is smoothed. As a result, the recess 30 is recessed more than the difference between the width L1 of the punch 42 and the width L2 of the hole of the die 44, and the possibility that burrs or steps remain on the side surface 24 can be greatly reduced.

  The pressing surface 50a of the press part 50 in the side pressing step is set to a curvature that passes through the first rounded end Ra and the second rounded end Rb. The first round end Ra and the second round end Rb are boundaries at the side surface 24 of the first round corner portion 32a and the second round corner portion 32b.

  The radius of curvature r of the pressing surface 50a may be set based on the positions of the first round end Ra and the second round end Rb and the plate thickness T of the plate member 40 (bus bar 10). Thereby, the smooth recessed part 30 can be formed in the side surface of the side surface 24, leaving the round corner part 32. FIG.

  The bus bar 10 has a plate thickness used at a high voltage, and is formed with a plate thickness in the range of 2 to 5 mm, for example. By having a plate thickness of 2 millimeters or more, the side pressing process can be easily performed. By using aluminum as the plate member 40, it is easy to ensure the plate thickness T of the bus bar 10 that facilitates the side pressing process. Note that another conductive metal such as copper or stainless steel may be used as the plate member 40.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added to the embodiments based on the knowledge of those skilled in the art, and such modifications have been added. Embodiments may also be included within the scope of the present invention.

  10 busbars, 12 conductive portions, 20 connecting end portions, 22 both plate surfaces, 22a first plate surfaces, 22b second plate surfaces, 24 side surfaces, 26 insulating coating portions, 28 coating boundaries, 30 concave portions, 32a first round corner portions 32b 2nd round corner part, 32 round corner part, 40 plate material, 42 punch, 44 die | dye, 48 primary molded article, 50 press part, 50a pressing surface.

Claims (5)

A bus bar formed of plate material,
Both side surfaces located on the sides of both plate surfaces;
Round corners formed by rounding the respective corners where both the plate surfaces and the both side surfaces intersect,
Insulating film portions formed in a predetermined range of both the plate surfaces and the both side surfaces,
The said both side surface has a recessed part formed recessed between the said round corner parts, The bus bar characterized by the above-mentioned.   The bus bar according to claim 1, wherein the recess extends longer than a predetermined range of the insulating coating portion. A method of manufacturing a bus bar formed of a plate material,
A half-punching step of pressing the plate material in the direction perpendicular to the middle and forming a protruding portion on the plate material;
A punching process in which the protruding part of the plate material is pressed in the opposite direction of the half-punching process to punch out the primary molded product of the bus bar; and
A side pressing step for pressing to form recesses for recessing both side surfaces of the primary molded product;
A method of manufacturing a bus bar, comprising: an insulating forming step of forming an insulating film on the primary molded product so as to be within a range in which the concave portion extends.   4. The method of manufacturing a bus bar according to claim 3, wherein the side pressing step presses in the plate width direction while leaving a rounded corner formed by half punching to form the curved concave portion. The half-punching step is a portion in which the plate material is pressed to the middle of the plate thickness in the perpendicular direction by a punch having a width larger than the width of the bus bar and a die having a width smaller than the width of the punch. Form the
5. The method of manufacturing a bus bar according to claim 3, wherein the recess formed by the side pressing step is formed to be recessed more than a difference between a width of the punch and the die.

Images