JP2014074678A - Current detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current detector allowing space saving.SOLUTION: The current detector includes: a control unit 8 disposed in an inverter unit 1 for mutually converting between direct-current power and alternating-current power; a plurality of bus bars 11-16 connected to the control unit 8; and a plurality of magnetic detection elements 21-23 for detecting the current flowing through the bus bars 11-13 without using a magnetic core. The plurality of bus bars 11-16 and the plurality of magnetic detection elements 21-23 are disposed in a projected area of the control unit 8.

Description

  The present invention relates to a current detection device, and more particularly to a current detection device that detects a current flowing in a bus bar.

  A current sensor that detects an energization current of a bus bar by measuring a magnetic flux generated by a current flowing through the bus bar is often used. As a conventional example of this type of current sensor, for example, a Hall IC type current sensor has been proposed (see, for example, Patent Document 1).

  The conventional Hall IC type current sensor described in Patent Document 1 has a configuration in which a Hall IC is fitted and held in a receiving portion of the Hall IC holder, and a pair of fixing arms of the Hall IC holder is sandwiched and fixed on both sides of a plate-like bus bar. It has become. According to such a configuration, the cost and size can be reduced, and the assembling property of the in-vehicle power conversion device can be simplified.

JP 2005-218219 A

  The conventional Hall IC type current sensor described in Patent Document 1 requires a Hall IC holder that fits and holds the Hall IC and clamps and fixes both sides of the bus bar. When a plurality of bus bars are used for electrical connection with the outside, the installation space for installing the Hall IC holder for each of the plurality of bus bars is expanded. Securing the installation space for the Hall IC holder is not suitable for in-vehicle use where the installation space is limited.

  An object of the present invention is to provide a current detection device capable of saving space.

[1] The present invention flows to the bus bar without using a control unit provided in an inverter unit that mutually converts DC power and AC power, a plurality of bus bars connected to the control unit, and a magnetic core. A plurality of magnetic detection elements for detecting current, wherein the plurality of bus bars and the plurality of magnetic detection elements are arranged within a projected area of the control unit. is there.

[2] In the invention described in [1], the bus bar includes a bus bar assembly in which the plurality of bus bars are molded, and a magnetic detection element assembly in which the plurality of magnetic detection elements are molded. The assembly and the magnetic detection element assembly are fixed through fixing means.

[3] In the invention according to [1] or [2], the plurality of bus bars are provided with terminal portions that are electrically connected to the control unit.

[4] In the invention according to any one of [1] to [3], the magnetic detection element is a Hall IC.

  According to the present invention, it is possible to achieve space saving and downsizing of the current detection device.

It is a schematic diagram for demonstrating one structural example of the motor drive system of the hybrid vehicle carrying the inverter unit using the electric current detection apparatus which concerns on embodiment of this invention. It is a disassembled perspective view which shows typically the electric current detection apparatus which concerns on 1st Embodiment with which an inverter unit is mounted | worn. It is a disassembled perspective view which shows typically the electric current detection apparatus which concerns on 2nd Embodiment with which an inverter unit is mounted | worn.

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

[First Embodiment]
(Configuration of on-vehicle motor drive system)
In FIG. 1, the code | symbol 1 has shown the inverter unit of the hybrid vehicle. A drive motor 2 that drives the drive shaft and a power generation motor 3 that generates power using engine power are electrically connected to the inverter unit 1 through three-phase cables 4 and 5, respectively.

  The power from the engine is divided into driving power and power generation power. Three-phase (U-phase, V-phase, W-phase) AC power generated by the power generation motor 3 based on power for power generation from the engine is converted into DC power by the inverter unit 1. The DC power is stepped down by the converter 6 and then stored in the battery 7 which is a DC power source. On the other hand, the DC power of the battery 7 is boosted by the converter 6 and then converted into three-phase AC power by the inverter unit 1. The three-phase AC power is supplied to the drive motor 2.

  As shown in FIG. 1, various components such as control units 8 and 8 and current sensor units 9 and 9 are mounted in the inverter unit 1. The control unit 8 is a semiconductor module in which a semiconductor element or the like mounted on a substrate (not shown) is molded in a rectangular parallelepiped shape with a resin material, and the detection result of the current sensor unit 9 that detects current in a non-contact manner with respect to the bus bar. Based on this, the current value is calculated. The inverter unit 1 includes a so-called power card that cools heat generated when a semiconductor element or the like operates.

(Configuration of current detection device)
By the way, when a specification part is separately delivered and assembled from an inverter maker or a sensor maker, the structure which can reduce an assembly man-hour by reducing the number of parts is desired. Therefore, the main basic configuration of the vehicle-mounted motor drive system according to the first embodiment is in a current detection device that is a component of the inverter unit 1.

  The current detection device according to the illustrated example includes a pair of current sensor units 9 and 9. Since the current sensor unit 9 has the same structure, only the structure and members on one side will be described in the following description.

  As shown in FIG. 2, the current sensor unit 9 has a bus bar assembly 10 and a magnetic detection element assembly 20 integrated with a resin material by insert molding. Since the drive motor 2 and the power generation motor 3 for the hybrid vehicle are driven by three-phase AC power, the electrical connection between the inverter unit 1 and the drive motor 2 and the electrical connection between the inverter unit 1 and the power generation motor 3 The first to sixth six bus bars 11 to 16 are used.

  As illustrated in FIG. 2, the current sensor unit 9 according to the illustrated example forms a bus bar assembly 10 including first to third bus bars 11 to 13. The bus bars 11 to 13 are plate-like members made of a conductive material such as copper or a copper alloy. One end portion thereof is molded with a resin material, and the other end portion projects from the resin material as a terminal portion. The first bus bar 11 is supplied with U-phase AC power, the second bus bar 12 is supplied with V-phase AC power, and the third bus bar 13 is supplied with W-phase AC power from the inverter unit 1.

  On the other hand, as shown in FIG. 2, the fourth to sixth bus bars 14 to 16 are members made of a conductive material such as copper or a copper alloy, like the first to third bus bars 11 to 13. One end of each of the bus bars 14 to 16 is molded with a resin material in a state of being electrically connected to the first to third bus bars 11 to 13, and the other ends of the bus bars 14 to 16 are Projecting toward the control unit 8 from the upper surface of the resin material.

  As shown in FIG. 2, the other end portions of the bus bars 14 to 16 correspond to the three rod-like connection terminals 8 a to 8 c provided in the control unit 8 and are connected to each other by welding. It is configured as a terminal part. The fourth bus bar 14 is supplied with U-phase AC power, the fifth bus bar 15 is supplied with V-phase AC power, and the sixth bus bar 16 is supplied with W-phase AC power from the generator motor 3.

  The current sensor unit 9 further forms a magnetic detection element assembly 20 including first to third magnetic detection elements 21 to 23 as shown in FIG. The first to third magnetic detection elements 21 to 23 that detect current in a non-contact manner are arranged one by one with respect to the first to third bus bars 11 to 13. Each of the magnetic detection elements 21 to 23 includes a Hall IC in which an amplifier or the like is packaged as an integrated circuit, and is used as a coreless current sensor having no magnetic core.

  In the illustrated example, the bus bars 11 to 16 and the magnetic detection elements 21 to 23 employ a configuration in which the control units 8 are arranged in a state of being scattered within a projected area projected downward. Therefore, the structure which avoids the magnetic interference of the adjacent bus bars 11-16 can be obtained effectively.

  As shown in FIG. 2, the magnetic detection elements 21 to 23 are mounted on a substrate 24 and detect a magnetic field generated when a current is passed through each of the corresponding first to third bus bars 11 to 13. To do. The detection results of the magnetic detection elements 21 to 23 are output to the control unit 8 via three signal lines (not shown). In the control unit 8, the current value supplied between the inverter unit 1 and the drive motor 2 and the current value supplied between the inverter unit 1 and the power generation motor 3 are recognized.

(Effects of the first embodiment)
According to the current sensor unit 9 configured as described above, the following effects can be obtained in addition to the above effects.

(1) Since the structure of the current sensor unit 9 can be simplified, for example, when an automobile manufacturer separately supplies specification parts from an automotive parts manufacturer of an inverter or a sensor and assembles the parts at the automobile manufacturer, the number of parts is Since it is reduced, it is possible to reduce the assembly man-hours on the automobile manufacturer side and improve the assembly work on the automobile manufacturer side.
(2) In addition to reducing the projected area of the inverter unit 1, the area occupied by the inverter unit 1 can be reduced.

[Second Embodiment]
Referring to FIG. 3, there is illustrated a current sensor unit 9 according to the second embodiment. In the first embodiment, the configuration in which the plurality of bus bars 11 to 16 and the plurality of magnetic detection elements 21 to 23 are used as inserts and integrated by insert molding in which a molten resin is injection molded is illustrated. In the embodiment, the current sensor unit 9 in which the bus bar assembly 10 and the magnetic detection element assembly 20 are formed separately is illustrated.

  In the figure, the substantially same members as those in the first embodiment are given the same member names and symbols. Therefore, the detailed description regarding these members is omitted.

  As shown in FIG. 3, the bus bar assembly 10 includes first to sixth six bus bars 11 to 16 molded with a resin material, and a terminal portion that is electrically connected to the inverter unit 1. The first to third bus bars 11 to 13 for current detection are formed as an integrated body including the fourth to sixth bus bars 14 to 16.

  As shown in FIG. 3, one of the magnetic detection element assemblies 20 includes first to third magnetic detection elements 21 to 23 molded with a resin material, and the first to third bus bars 11. Are formed at positions corresponding to .about.13.

  As shown in FIG. 3, the bus bar assembly 10 and the magnetic detection element assembly 20 are arranged in parallel with the connection surface of the control unit 8 in the vertical direction, and use fixing means such as welding or bolt tightening. Fixed. Since the area occupied by the current sensor unit 9 can be reduced, it is possible to adopt a configuration in which the inverter unit 1 is arranged in a state of being scattered within the projected area when viewed from above.

(Effect of the second embodiment)
The current sensor unit 9 according to the second embodiment configured as described above has the following effects in addition to the effects of the first embodiment.

(1) The current sensor unit 9 can be arranged compactly. Thereby, the current sensor unit 9 can be concentrated in the projected area of the control unit 8.
(2) The inverter unit 1 can be reduced in size, and the degree of freedom in the layout of the control unit 8 and the current sensor unit 9 can be improved.

[Modification]
As described above, the current sensor of the present invention has been described based on the above-described embodiment and illustrated examples. However, the present invention is not limited to the above-described embodiment and illustrated examples, and various modifications can be made without departing from the scope of the present invention. It can be implemented in embodiments. In the present invention, the following modifications are possible.

(1) In each of the above-described embodiments and illustrated examples, an example in which the connection terminals 8a to 8c of the control unit 8 and the bus bars 14 to 16 of the bus bar assembly 10 are connected by welding is illustrated, but the present invention is limited to this. For example, the connecting portion of the control unit 8 may be a female connection terminal, and a fitting type connection structure in which the female connection terminal and the bus bar are electrically connected to each other may be used.
(2) In each of the above-described embodiments and illustrated examples, the current sensor unit 9 on the drive motor 2 side and the current sensor unit 9 on the power generation motor 3 side are illustrated as an example. For example, a pair of current sensor units 9 may be integrated.
(3) The present invention can be applied to electric circuits other than electric circuits connected to vehicle motors and batteries.
(4) It may be other than a coreless current sensor that performs current detection without using a magnetic core. For example, the present invention can be applied to a current sensor that performs current detection using a magnetic core.
(5) In each of the above-described embodiments and illustrated examples, an example mounted on a hybrid vehicle is illustrated, but it is needless to say that the present invention can be applied to other vehicles such as an electric vehicle.

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

DESCRIPTION OF SYMBOLS 1 ... Inverter unit, 2 ... Drive motor, 3 ... Electric power generation motor, 4, 5 ... Cable, 6 ... Converter, 7 ... Battery, 8 ... Control unit, 8a-8c ... Connection terminal, 9 ... Current sensor unit, 10 ... Bus bar assembly, 11-16 ... Bus bar, 20 ... Magnetic detection element assembly, 21-23 ... Magnetic detection element, 24 ... Substrate

Claims (4)

A control unit provided inside the inverter unit that mutually converts DC power and AC power;
A plurality of bus bars connected to the control unit;
A plurality of magnetic detection elements for detecting a current flowing through the bus bar without using a magnetic core;
With
The current detecting device, wherein the plurality of bus bars and the plurality of magnetic detection elements are arranged within a projected area of the control unit. The bus bar assembly in which the plurality of bus bars are molded, and the magnetic detection element assembly in which the plurality of magnetic detection elements are molded,
The current detection device according to claim 1, wherein the bus bar assembly and the magnetic detection element assembly are fixed through fixing means.   The current detection device according to claim 1, wherein the plurality of bus bars are provided with terminal portions that are electrically connected to the control unit.   The current detection device according to claim 1, wherein the magnetic detection element is a Hall IC.

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