JP2014087192A - Bus bar structure and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bus bar structure for improving accuracy of position or accuracy of form and to provide a method of manufacturing the same.SOLUTION: A bus bar structure includes a bus bar 3 in which current flows, and a molding member 2 which covers an end part of the bus bar 3 and exposes an extended part 3a extending from the end part. The extended part 3a is constructed as an inspection section for a current measurement. A bending extended part 3b, which is formed by bending the extended part 3a for a side surface 2a of the molding member 2 after current measurement, is constructed as an electric conductor fixed part for fixing an electric conductor.

Description

  The present invention relates to a bus bar structure and a manufacturing method thereof.

  A control unit mounted on a vehicle has been proposed (see, for example, Patent Document 1).

  The conventional control unit described in Patent Document 1 includes a recess in which a part of a bus bar made of a conductive plate embedded in a housing by insert molding is bent in an L shape on the side of the housing. ing. By inserting a nut into the recess and fastening the terminal with a hole to the nut with a bolt, the terminal with the hole is electrically connected to the bus bar.

Japanese Patent Laid-Open No. 9-296815

  By the way, when manufacturing this type of bus bar structure, it is necessary to set the clearance between the side part of the housing and the bus bar appropriately, and the bus bar bending angle is set within a predetermined range. There is a need to.

  Due to its structure, it is necessary to make advanced adjustments such as setting position alignment between the side of the housing and the bus bar, and the setting position adjustment must be strictly inspected, and strict quality control is required. The

  On the other hand, when the bus bar is mounted on the housing, the measurement probe is strongly pressed against the bus bar, whereby a large current of several hundred amperes is applied to the bus bar, and the performance inspection is performed.

  If a current is continuously passed through the measurement probe in a state where there is a high contact resistance between the bus bar and the bolt / nut, heat generation due to the contact resistance may increase and reach several hundred degrees Centigrade. For this reason, when the tightening state of the bolt and nut is coupled with the contraction of the housing, the contact resistance increases and heat generation is promoted. Therefore, in order to reduce the contact resistance, it is necessary to deal with it by firmly fastening the bolts and nuts or pressing the measurement probe strongly against the bus bar.

  However, since the bending rigidity of the bus bar in the plate thickness direction is small and easily deformed, when the pressing force of the measurement probe is applied to the bus bar, the pressing force is easily transmitted to the bus bar. Accordingly, there has been a problem that the position accuracy and shape accuracy of the bus bar with respect to the side portion of the housing are lowered.

  An object of the present invention is to provide a bus bar structure and a method for manufacturing the same, which are improved in position accuracy and shape accuracy.

[1] The present invention includes a bus bar through which an electric current flows and a mold member that covers one end of the bus bar and exposes an extending portion that extends from the one end, and the extending portion receives an electric current. Constructed as an inspecting part to be measured, and a bent extending part formed by bending the extending part after current measurement with respect to the side surface of the mold member constitutes a conductor fixing part for fixing the conductor It is in the busbar structure characterized by being formed.

[2] In the invention according to the above [1], an opening is formed at one end of the mold member, and a nut accommodating portion for accommodating a nut is formed inside the opening, and the bent extension The present portion is formed by being bent at a predetermined interval with respect to the nut housing portion.

[3] The present invention further relates to a method of manufacturing the bus bar structure according to [1], wherein an inspection step of measuring a current flowing through the bus bar in the extension portion, and the extension portion after the current measurement are performed. The manufacturing method of a bus bar structure is characterized by sequentially performing a bending process of bending.

  According to the present invention, the position accuracy and shape accuracy of the bus bar can be effectively ensured.

It is a principal part perspective view which cuts in part and shows typically the electric current sensor provided with the typical bus-bar structure which concerns on embodiment of this invention. It is principal part sectional drawing of the II-II arrow of FIG. It is figure (a)-(c) which shows typically the process for manufacturing the bus-bar structure concerning an embodiment.

  Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

(Overall configuration of current sensor)
In FIG. 1, reference numeral 1 generally indicates a current sensor having a typical bus bar structure in this embodiment. The current sensor 1 is not particularly limited, and is a current sensor mounted on, for example, a control unit that controls the vehicle power supply, and is used to detect the magnitude of the current flowing through the bus bar 3.

  As shown in FIG. 1, the current sensor 1 includes a rectangular parallelepiped mold member 2 constituted by a connector housing having an opening. One end of a bus bar 3 having a long flat plate shape, which is a conductor through which a current flows, is integrated with the mold member 2 by molding. An extended end 3 a extending from one end of the bus bar 3 is exposed at an open end formed on the side surface 2 a in the longitudinal direction of the mold member 2.

  As shown in FIGS. 1 and 2, a nut accommodating portion 2 b that accommodates the nut 4 is formed at the opening end portion of the mold member 2. In the nut housing portion 2b, a required number of ribs 2c,..., 2c that are held in a state where the nut 4 is inserted into the opening end portion of the mold member 2 are formed along the longitudinal direction with a predetermined phase difference.

  As the mold member 2, a material excellent in insulation and moisture resistance is preferable, and for example, polyphenylene sulfide (PPS) resin or the like is used. As the bus bar 3, for example, a metal material such as copper or a copper alloy is used.

  On the outer periphery of the bus bar 3, components such as a core (not shown) for collecting the magnetic field formed by the bus bar 3 and a magnetic detection element (not shown) for detecting the strength of the magnetic field generated by the current flowing through the bus bar 3 are provided. . As the magnetic detection element, for example, a GMR element, MR element, Hall element, Hall IC or the like is used.

(Bus bar structure)
As shown in FIGS. 1 and 2, the extended portion 3 a of the bus bar 3 is configured as a bent extended portion 3 b formed by bending along the side surface 2 a of the mold member 2. The bent extending portion 3 b extends with a predetermined clearance (interval) C on the side surface 2 a in the longitudinal direction of the mold member 2.

  As shown in FIGS. 1 and 2, a circular bolt insertion hole 3 c corresponding to the nut 4 is formed in the bent extending portion 3 b of the bus bar 3. The screw portion of the bolt (not shown) is inserted into the nut accommodating portion 2b via the bolt insertion hole of another bus bar (not shown) and the bolt insertion hole 3c of the bus bar 3, and is fastened and fixed by the nut 4.

  In the current sensor 1 configured as described above, a performance test is performed to determine whether or not the current sensor 1 is formed as designed. Although this performance inspection is not particularly specified, for example, a measurement probe that measures the current flowing through the bus bar 3 and a measurement that performs current supply and current measurement on the bus bar 3 and observes the current measured by the measurement probe. And an inspection apparatus equipped with a vessel.

  When the current sensor 1 is inspected for performance, a large current of several tens to several hundreds of amperes may be caused to flow through the bus bar 3 by the measurement probe. Become. Therefore, the bus bar 3 is likely to be deformed such as bending, and it becomes difficult to maintain the clearance C between the side surface 2a of the mold member 2 and the bus bar 3 at an initial target dimensional interval. Therefore, it is important to improve the position accuracy and shape accuracy of the bus bar 3.

  The main configuration of the current sensor 1 according to this embodiment is the structure of the bus bar 3 that ensures the positional accuracy and shape accuracy of the bus bar 3, and the method for manufacturing the bus bar structure.

  As shown in FIG. 3A, the bus bar 3 is set as an inspection portion that is sandwiched by a measurement probe 101 that measures the current flowing through the bus bar 3, with the extended portion 3 a extending from the mold member 2. The As shown in FIGS. 3B and 3C, the extended portion 3a after the current measurement is formed by bending the bent extended portion 3b formed by bending the side surface 2a of the mold member 2 with another bus bar. And a conductor fixing part for fixing a connection terminal and the like.

(Manufacturing method of bus bar structure)
In the manufacturing method of the bus bar structure according to this embodiment, a conductive metal plate to be the bus bar 3 is punched into a required outer shape by pressing and a bolt punching hole 3c is punched, and one end portion of the bus bar 3 and An intermediate product of the current sensor 1 is manufactured through a resin molding process in which the current sensor component is insert-molded into a resin material. Before the intermediate product bus bar 3 is bent, an inspection process using a measurement probe is performed.

  As shown in FIGS. 3A to 3C, the manufacturing method of the bus bar structure includes a series of processes for sequentially performing an inspection process and a bending process. By the manufacturing method including this process, the current sensor 1 having a bus bar structure in which positional accuracy and shape accuracy are ensured can be effectively obtained.

(Inspection process)
In this inspection process, a performance inspection of the current sensor 1 is performed. As shown in FIG. 3A, the inspection apparatus used for the performance inspection of the current sensor 1 is brought into contact with the measurement probes 101, 101 sandwiched between both surfaces of the extension portion 3a of the bus bar 3 to be measured. By supplying the measurement current to the bus bar 3 through the measurement probe 101, the current measured by the measurement probe 101 is observed by a measuring instrument (not shown).

(Bending process)
As shown in FIG. 3B, the bending process includes a step of housing the nut 4 in the nut housing portion 2 b of the mold member 2. In the bending process, a supporting jig 201 and a pressing jig 202 that can be moved back and forth are used. The supporting jig 201 has a press surface that protrudes corresponding to the cross-sectional shape of the bent portion of the extending portion 3 a of the bus bar 3.

  In this bending process, first, the nut 4 is housed in the nut housing portion 2 b of the mold member 2. Next, the jig 201 is brought into contact with one surface of the extending portion 3 a of the bus bar 3. Subsequently, a predetermined portion of the bus bar 3 is deformed into a bent shape by pressing the jig 202 against the other surface.

  Through the above manufacturing process, the extending portion 3a of the bus bar 3 is bent with a predetermined clearance C with respect to the side surface 2a in the longitudinal direction of the mold member 2 as shown in FIG.

(Effect of embodiment)
In addition to the above effects, the following effects can be obtained by employing the bus bar structure configured as described above and the manufacturing method thereof.

(1) The clearance C between the side surface 2a of the mold member 2 and the bus bar 3 can be set within a predetermined range, so that high quality and low cost can be achieved.
(2) The work of adjusting the set position of the bus bar 3 with respect to the mold member 2 can be reduced, and the workability of fixing the counterpart bus bar, connection terminal, etc. to the current sensor 1 can be improved.
(3) Since the inspection process using the measurement probe 101 is performed before the bus bar 3 is bent, it is possible to reliably prevent the heat generation accompanying the increase in contact resistance.

[Modification]
As mentioned above, although the bus-bar structure of this invention and its manufacturing method were demonstrated based on the said embodiment and example of illustration, this invention is not limited to the said embodiment and example of illustration, and does not deviate from the summary. It can be implemented in various ways within the scope. In the present invention, the following modifications are possible.

(1) The present invention can be applied to other electric circuits other than the electric circuit connected to the control unit that controls the vehicle power source.
(2) The present invention can be applied to a current sensor that performs current detection using a core and a coreless current sensor that performs current detection without using a core.

  As is clear from the above description, typical embodiments, modifications, and illustrations according to the present invention have been illustrated. However, the above-described embodiments, modifications, and illustrations relate to the claims. The invention is not limited. Therefore, it should be noted that not all the combinations of features described in the above embodiments, modifications, and illustrated examples are necessarily essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 1 ... Current sensor, 2 ... Mold member, 2a ... Side surface, 2b ... Nut accommodating part, 2c ... Rib, 3 ... Bus bar, 3a ... Extension part, 3b ... Bending extension part, 3c ... Bolt insertion hole, 4 ... Nut, 101 ... measurement probe, 201, 202 ... jig

Claims (3)

A bus bar through which current flows,
The one end part of the bus bar is covered and a mold member that exposes an extending part extending from the one end part.
The extension part is configured as an inspection part for measuring current, and the extension part formed by bending the extension part after current measurement with respect to the side surface of the mold member fixes the conductor. A bus bar structure configured as a conductor fixing portion. An opening is formed at one end of the mold member,
Inside the opening, a nut accommodating portion for accommodating a nut is formed,
The bus bar structure according to claim 1, wherein the bent extension portion is bent at a predetermined interval with respect to the nut housing portion. A method of manufacturing the bus bar structure according to claim 1,
A method of manufacturing a bus bar structure, comprising sequentially performing an inspection step of measuring a current flowing through the bus bar in the extended portion and a bending step of bending the extended portion after the current measurement.

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