JP2011209158A - Current sensor assembly and method for assembling the same - Google Patents

Abstract

A current sensor assembly and a method of assembling the current sensor assembly having a structure capable of facilitating downsizing of a current sensor assembly and bending of a bus bar and improving the yield of the current sensor assembly.
A plurality of round bar bus bars 211, 212, 213, 221, 222, and 223 having a circular cross section are provided. Further, the mounting positions of the round bar bus bars 211, 212, 213, 221, 222, 223 with respect to the resin case 250 are fixed between the round bar bus bars 211, 212, 213, 221, 222, 223 and the resin case 250. A positioning structure is provided.
[Selection] Figure 2

Description

  The present invention relates to a current sensor assembly having a plurality of current sensors for detecting a current flowing in a bus bar, and an assembling method thereof.

  In a vehicular electric device used in a hybrid vehicle, an electric vehicle, or the like, a motor generator terminal and a PCU inverter terminal are electrically connected using a bus bar. A current sensor is used to detect the current flowing through the bus bar. Patent Documents 1 to 5 listed below are disclosed as a connection structure between terminals using such a bus bar and a current sensor.

  Conventional bus bars are often flat bus bars having a rectangular cross section. Further, from the relationship between the terminal position of the motor generator and the terminal position of the inverter of the PCU, when arranging a plurality of flat bus bars side by side, along the direction in which the longitudinal side of the cross section of the flat bus bar extends, A flat bus bar is arranged. As a result, it is necessary to arrange the current sensors in accordance with the arrangement pitch of the flat bus bars. For this reason, when the current sensors are arranged side by side, the current sensor assembly is enlarged.

  Further, it is necessary to bend the flat bus bar from the relationship between the terminal position of the motor generator and the terminal position of the inverter of the PCU. In this case, the flat bus bar is bent after passing the flat bus bar through the current sensor. However, the bending process for the flat bus bar, particularly the bending process along the direction in which the longitudinal side of the cross section of the flat bus bar extends, has many processing restrictions. In addition, the positional relationship between the flat bus bar and the current sensor changes (changes in the gap), which reduces the yield of the current sensor assembly.

JP 09-093771 A JP 2009-156803 A JP 2009-156802 A JP 2003-045331 A JP 2004-104872 A

  The problem to be solved by the present invention is that the yield of the current sensor assembly is increased due to the increase in size of the current sensor assembly, the restriction on the bending process of the flat bus bar, and the bending process of the flat bus bar. It is in the point to decline. Accordingly, an object of the present invention is to solve the above problems, and it is possible to reduce the size of the current sensor assembly, facilitate the bending of the bus bar, and improve the yield of the current sensor assembly. It is an object of the present invention to provide a current sensor assembly having a structure and a method for assembling the current sensor assembly.

  In the current sensor assembly according to the present invention, a plurality of round bar bus bars having a circular cross section, and a plurality of currents having a current sensor core and a current sensor element provided in a substantially annular shape so as to pass through the round bar bus bars. A sensor case, and a resin case that includes a through-hole through which the round bar bus bar passes and in which a plurality of the current sensor cores are integrated in order to pass the round bar bus bar through the current sensor core, the round bar bus bar and the resin A positioning structure for fixing the mounting position of the round bar bus bar to the resin case is provided between the case and the case.

  In another form of the current sensor assembly, the positioning structure fixes the position of the round bar bus bar in the axial direction relative to the resin case, so that the round bar bus bar intersects the axial direction. A flange extending in the direction is provided, and the resin case is provided with an enlarged diameter portion that receives the flange from the axial direction side.

  In another form of the current sensor assembly, the positioning structure fixes the position around the axis of the round bar bus bar with respect to the resin case, so that the round bar bus bar intersects the axial direction. Convex portions projecting in the direction are provided, and the resin case is provided with concave portions that receive the convex portions from a direction intersecting the axial direction.

  In the method of assembling the current sensor assembly according to the present invention, the step of arranging a plurality of substantially ring-shaped current sensor cores, and the current sensor cores are made of resin so as to have through holes penetrating the current sensor cores. Forming a resin case integrated with each other, positioning each of the through holes provided in the resin case by penetrating a plurality of round bar bus bars having a circular cross section, and each of the above A step of performing terminal processing on the round bar bus bar, and a step of mounting the current sensor element at a predetermined position of the current sensor core.

  In another form of the method of assembling the current sensor assembly, the method further includes the step of bending the round bar bus bar after positioning the round bar bus bar with respect to the resin case. .

  According to the current sensor assembly and the assembly method thereof based on the present invention, the current sensor assembly has a structure capable of facilitating the downsizing of the current sensor assembly and the bending of the bus bar and improving the yield of the current sensor assembly. It is possible to provide a current sensor assembly and an assembly method thereof.

It is the schematic of the electric power supply system to a motor generator. It is a perspective view showing the whole current sensor assembly composition in an embodiment. It is a fragmentary perspective view which shows the internal structure of the current sensor assembly in embodiment. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. It is sectional drawing equivalent to the IV-IV line arrow in FIG. 3 at the time of using a flat type bus bar whose cross section is a rectangle. It is a perspective view which shows the whole structure of the resin case in embodiment. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. FIG. 7 is a cross-sectional view taken along line VIII-VIII in FIG. 6. It is a conceptual diagram which shows the manufacturing process of the current sensor core for round bar bus bars. It is a conceptual diagram which shows the manufacturing process of the current sensor core for flat type bus bars. It is a conceptual diagram which shows the manufacturing process of a flat type bus bar. It is a 1st process drawing which shows the assembly method of the current sensor assembly in embodiment. It is a 2nd process figure which shows the assembly method of the current sensor assembly in embodiment. It is a 3rd process figure which shows the assembly method of the current sensor assembly in embodiment. It is a 4th process figure showing the assembly method of the current sensor assembly in an embodiment. It is a 5th process figure showing the assembly method of the current sensor assembly in an embodiment.

  A current sensor assembly and an assembling method thereof according to an embodiment of the present invention will be described below with reference to the drawings. Note that in the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. The same parts and corresponding parts are denoted by the same reference numerals, and redundant description may not be repeated.

(Power supply system to motor generator)
An example in which the current sensor assembly according to the present embodiment is applied to a vehicle drive device will be described below with reference to FIG. FIG. 1 is a schematic diagram of a power supply system to the motor generator. The vehicle drive device includes an engine, a motor generator MG1 that serves both as an electric motor and a generator and mainly operates as a generator, and a motor generator MG2 that mainly operates as a motor.

  The power supply system to motor generators MG1 and MG2 includes a battery 106 made of a secondary battery such as nickel metal hydride or lithium ion, and a power control unit (hereinafter referred to as “PCU”) 110. PCU 110 includes a boost converter 105 that boosts a DC voltage supplied from battery 106, and inverters 103 and 104 that convert the DC voltage from boost converter 105 into an AC voltage and supply the AC voltage to motor generators MG1 and MG2. .

  When motor generators MG1 and MG2 operate as generators, the AC voltage from motor generators MG1 and MG2 is converted into a DC voltage by inverters 103 and 104, and is further stepped down by boost converter 105 before being transferred to battery 106. Charged.

  The U-phase, V-phase, and W-phase between motor generator MG1 and inverter 103 are connected by bus bars 11, 12, and 13, respectively. U-phase, V-phase, and W-phase between motor generator MG2 and inverter 104 are Are connected by bus bars 21, 22, 23, respectively.

  Bus bars 11, 12, 13, 21, 22 and 23 are provided with current sensor assemblies 200 for detecting motor currents (ie, inverter output currents) flowing through motor generators MG 1 and MG 2. In this current sensor assembly 200, motor currents for two phases of the U phase, V phase, and W phase of the motor currents flowing through motor generators MG1 and MG2 (for example, V phase current iv and W phase current iw). ) Is detected.

(Configuration of current sensor assembly 200)
Next, the configuration of the current sensor assembly 200 in the present embodiment will be described with reference to FIGS. First, a schematic configuration of the current sensor assembly 200 will be described with reference to FIGS. 2 is a perspective view showing the overall configuration of the current sensor assembly 200, FIG. 3 is a partial perspective view showing the internal structure of the current sensor assembly 200, and FIG. 4 is an arrow IV-IV in FIG. FIG. In FIGS. 3 and 4, the resin case 250 is shown by a broken line in order to clearly show the internal structure.

  The current sensor assembly 200 includes a plurality of round bar bus bars 211, 212, 213, 221, 222, and 223 having a circular cross section. Round bar bus bar 211 is used for W-phase connection of motor generator MG1, round bar bus bar 212 is used for V-phase connection of motor generator MG1, and round bar bus bar 213 is used for U-phase connection of motor generator MG1. Round bar bus bar 221 is used for W-phase connection of motor generator MG2, round bar bus bar 222 is used for V-phase connection of motor generator MG2, and round bar bus bar 223 is used for U-phase connection of motor generator MG1.

  The round bar bus bars 211, 212, 213, 221, 222, and 223 are subjected to a predetermined bending process based on the relationship between the terminal positions of the motor generators MG 1 and MG 2 and the terminal positions of the inverters 103 and 104 of the PCU. Furthermore, the terminal processing for a connection is given to the both ends of each round bar bus bar 211,212,213,221,222,223. As the terminal processing, flat plate portions 211b having connection holes 211c are provided at both ends of 211, 212, 213, 221, 222, and 223. There are bus bars that do not require bending.

  The current sensor assembly 200 has a resin case 250. The resin case 250 includes a main body 251 that holds the round bar bus bars 211, 212, 221, and 222, and ears 252 and 252 that hold the round bar bus bars 213 and 223.

  As shown in FIG. 3, substantially annular current sensor cores 271c, 272c, 273c, and 274c are provided inside the main body portion 251 of the resin case 250, and the main body portion 251 of the resin case 250 and the current sensor cores 271c, 272c, 273c and 274c are integrated.

  Between the round bar bus bars 211, 212, 213, 221, 222, 223 and the resin case 250 (the main body 251 and the ears 252, 252), the round bar bus bars 211, 212, 213, 221, 222, 223 are provided. A positioning structure for fixing the mounting position of the resin case 250 to the resin case 250 is provided.

  Specifically, the round bar bus bars 211, 212, 213, 221, 222, and 223 intersect with a flange 2122 that projects in a direction intersecting the axial direction, and further intersects the axial direction from the flange 2122. A convex portion 2121 that projects in the direction is provided.

  On the other hand, the resin case 250 is provided with through holes 253 through which the round bar bus bars 211, 212, 213, 221, 222, and 223 pass, and the flange 2122 is attached to the surface of the resin case 250 of each through hole 253. A diameter-enlarged portion 254 that is received from the direction side, and a concave portion 256 that receives the convex portion 2121 from a direction intersecting the axial direction are provided.

  In this way, by providing the flange 2122 on the surface of the round bar bus bars 211, 212, 213, 221, 222, and 223, the flange 2122 is supported by the enlarged diameter portion 254. Therefore, the round bar bus bar is positioned in the axial direction. Can be easily performed.

  Further, by providing the convex portion 2121 on the surface of the round bar bus bar 211, 212, 213, 221, 222, 223, the convex portion 2121 is supported by the concave portion 256, so that the rotation of the round bar bus bar around the axis is restricted. Thus, the round bus bar can be easily positioned around the axis.

  If positioning of the round bar bus bar in the axial direction is not a problem, use only a positioning structure that regulates only the rotation of the round bar bus bar around the axis, or positioning of the round bar bus bar around the axis is a problem. If this is not the case, it is possible to employ only a positioning structure that restricts the axial movement of the round bar bus bar.

  As shown in FIG. 4, the current sensor cores 271c, 272c, 273c, and 274c are provided with slits 271s, 272s, 273s, and 274s, respectively, and the current sensor elements 281 are provided in the slits 271s, 272s, 273s, and 274s, respectively. , 282, 283, and 284 are inserted.

  The current sensor elements 281, 282, 283, 284 are inserted from the openings 261 provided in the resin case 250 through the slits 271 s, 272 s, 273 s, 274 s provided in the current sensor cores 271 c, 272 c, 273 c, 274 c, and the substrate. 260 is fixed.

  The current sensor core 271c and the current sensor element 281 constitute the current sensor 271 of the round bar bus bar 211, and the current sensor core 272c and the current sensor element 282 constitute the current sensor 272 of the round bar bus bar 212, and the current sensor core 273c The current sensor element 283 constitutes the current sensor 273 of the round bar bus bar 221, and the current sensor core 274 c and the current sensor element 284 constitute the current sensor 274 of the round bar bus bar 222.

  A cable 230 and a connector 240 for outputting electrical signals obtained from the current sensors 271, 272, 273, 274 are connected to the board 260 (see FIGS. 2 and 3).

  Here, FIG. 5 shows a cross-sectional structure of a current sensor assembly in the background art. In the background art, flat bus bars 211, 212, 213, 221, 222, and 223 having a rectangular cross section are used for the bus bars. The portions corresponding to the current sensor assembly 200 in the present embodiment shown in FIG. The round bar bus bar in the present embodiment and the flat bus bar in the background art have the same cross-sectional area.

  As is clear from the comparison between FIG. 4 and FIG. 5, in this embodiment (FIG. 4), since the round bar bus bar is used, the current sensor core also surrounds the round bar bus bar. The substantially annular shape is provided.

  On the other hand, in the case of the background art (FIG. 5), since the flat bus bar is used, the current sensor core also has a rectangular shape surrounding the flat bus bar. As a result, even if it has the same function, the arrangement pitch (L1) of round bar bus bars can be made smaller than the arrangement pitch (L2) of flat bus bars. Further, since the round bus bar can be bent easily, the arrangement pitch of the current sensor cores can be minimized.

  As a result, as shown in the present embodiment, when a plurality of current sensor cores are arranged side by side, the current sensor assembly can be downsized compared to the current sensor assembly using the flat bus bar shown in FIG. Is possible.

(Assembly method of current sensor assembly 200)
Next, an assembly method of the current sensor assembly 200 will be described with reference to FIGS. First, the specific structure of the resin case 250 will be described with reference to FIGS. 6 is a perspective view showing the overall configuration of the resin case 250, FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6, and FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. It is.

  In a state where a plurality of substantially annular current sensor cores 271c, 272c, 273c, and 274c are arranged, the current sensor cores 271c, 272c, 272c, and the like have through holes 253 that penetrate the current sensor cores 271c, 272c, 273c, and 274c, respectively. A resin case 250 is formed by integrating 273c and 274c with resin.

  The resin case 250 has a through hole 253, and a body portion 251 in which the current sensor cores 271c, 272c, 273c, and 274c are integrated, and an ear portion 252 in which the through holes 253 are provided at both ends in the longitudinal direction of the body portion 251. , 252. On the surface of the through hole 253, a concave portion 256 and an enlarged diameter portion 254 are formed as a positioning structure.

  A substrate 260 for fixing the current sensor elements 281, 282, 283, and 284 is also integrated with the current sensor cores 271 c, 272 c, 273 c, and 274 c into the main body 251 of the resin case 250. In addition, the current sensor elements 281, 282, 283, and 284 are inserted into the slits 271 s, 272 s, 273 s, and 274 s provided in the current sensor elements 281, 282, 283, and 284 in the main body portion 251. An opening 261 for fixing 282, 283, and 284 to the substrate 260 is formed.

  Here, with reference to FIG. 9 and FIG. 10, the manufacture of the current sensor core in the present embodiment is compared with the manufacture of the conventional current sensor core. 9 is a conceptual diagram showing a manufacturing process of a current sensor core for a round bar bus bar, and FIG. 10 is a conceptual diagram showing a manufacturing process of a current sensor core for a flat bus bar.

  As shown in FIG. 9, since the current sensor core in the present embodiment has an annular shape, it can be manufactured by winding a belt-shaped core material T1 molded to a predetermined width around a winding core CP. The slit is formed by post-processing.

  On the other hand, as shown in FIG. 10, the current sensor core for a flat bus bar has a rectangular shape as a whole after the strip-shaped core material T1 molded to a predetermined width is wound around the winding core CP (FIG. 10A). In order to achieve this, it is necessary to perform a forming process (FIG. 10B). As described above, the current sensor core in the present embodiment can reduce the manufacturing cost because the number of steps can be reduced compared to the manufacturing process of the current sensor core for the flat bus bar.

  Next, with reference to FIG. 11, manufacture of a flat bus bar will be described. In addition, FIG. 11 is a conceptual diagram showing a manufacturing process of a flat bus bar. Since the flat bus bar has a rectangular cross section, as shown in FIG. 11, the flat bus bar T21 is manufactured by punching from the steel plate T2 using a press die (press work).

  For this reason, a machining allowance for press working (a margin part required between adjacent products) is required, and the yield with respect to the steel sheet becomes a problem. Further, when a flat bus bar having a bent shape is manufactured in advance, the machining allowance for press working is further increased, so that the yield is deteriorated and the manufacturing cost is increased.

  On the other hand, in the case of the round bar bus bar in the present embodiment, the material cost of the round bar bus bar can be reduced because the round bar material has only to be cut to a required length. Further, since the bending process for the round bar can be easily performed, the manufacturing cost can be further reduced.

  Next, a method for assembling the current sensor assembly 200 will be described with reference to FIGS. 12 to 16 following the step of preparing the resin case 250 of FIG. 12 to 16 are first to fifth process diagrams showing a method of assembling the current sensor assembly. The round bar bus bars 221, 222, and 223 will be described as an example, but the same applies to the round bar bus bars 211, 212, and 213.

  First, referring to FIG. 12, round bar bus bars 221, 222, and 223 having a predetermined length and having a flange 2122 and a projection 2121 provided on the surface are prepared. Next, referring to FIG. 13, a predetermined bending process is performed on one end side of round bar bus bars 221, 222, and 223 (flow area surrounded by X in FIG. 13). In some cases, it is not necessary to bend the bus bar due to the relationship between the motor generator terminal position and the PCU inverter terminal position.

  Next, referring to FIG. 14, the round bar bus bars 221, 222 are inserted into the through holes 253 provided in the resin case 250 from the end side where the round bar bus bars 221, 222, 223 are not bent. , 223 are passed. At this time, both can be easily positioned by the positioning structure provided between the round bar bus bars 221, 222, 223 and the resin case 250.

  Next, referring to FIG. 15, the opposite round bar bus bars 221, 222, and 223 that have passed through the resin case 250 are bent. In some cases, it is not necessary to bend the bus bar because of the relationship between the terminal position of the motor generator and the terminal position of the inverter of the PCU.

  Next, referring to FIG. 16, terminal processing is performed on both ends of round bar bus bars 221, 222, and 223. As the terminal processing, flat plate portions 211b having connection holes 211c are provided at both ends of the round bar bus bars 221, 222, and 223. The current sensor assembly 200 in the present embodiment is completed through the above steps.

(Action / Effect)
As described above, according to the current sensor assembly 200 in the present embodiment, by using a round bar bus bar as the bus bar, a substantially annular shape can be adopted for the current sensor core, and the current sensor assembly can be further downsized. Is possible. Further, it is possible to reduce the cost required for the round bar bus bar. Furthermore, a substantially annular shape can be adopted for the current sensor core, and the manufacturing cost of the current sensor core can be reduced.

  Further, by providing a positioning structure between the round bar bus bar and the resin case, it is possible to easily realize positioning between the two during the manufacturing process. As a result, the yield in the manufacturing process of the current sensor assembly 200 is improved, and the manufacturing cost of the current sensor assembly 200 can be reduced.

  Moreover, since the bending process with respect to a round bar bus bar is easy, it becomes possible to unitize the current sensor assembly in the state where the round bar bus bar is not attached, and it can also be used as a general-purpose product.

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  11, 12, 13, 21, 22, 23 Bus bar, 103, 104 inverter, 105 boost converter, 106 battery, 110 power control unit (PCU), 200 current sensor assembly, 211, 212, 213, 221, 222, 223 Round bar bus bar, 211b Flat part, 211c Connection hole, 2121 Protruding part, 2122 Flange, 230 Cable, 240 Connector, 250 Resin case, 251 Body part, 252 Ear part, 253 Through hole, 254 Wide diameter part, 256 Concave part , 260 substrate, 261 opening, 271, 272, 273, 274 current sensor, 271c, 272c, 273c, 274c current sensor core, 271s, 272s, 273s, 274s slit, 281, 282, 283, 284 current sensor element MG1, MG2 motor generator.

Claims (5)

A plurality of round bar bus bars with a circular cross section;
A plurality of current sensors having a current sensor core and a current sensor element provided in a substantially annular shape so as to pass through the round bar bus bar;
In order to pass the round bar bus bar through the current sensor core, including a through hole through which the round bar bus bar passes, and a resin case in which a plurality of the current sensor cores are integrated,
A current sensor assembly, wherein a positioning structure for fixing a mounting position of the round bar bus bar to the resin case is provided between the round bar bus bar and the resin case.   In order to fix the position of the round bar bus bar in the axial direction with respect to the resin case, the positioning structure is provided with a flange projecting in a direction intersecting the axial direction on the round bar bus bar. The current sensor assembly according to claim 1, wherein an enlarged diameter portion that receives the flange from the axial direction side is provided.   The positioning structure fixes a position around the axis of the round bar bus bar with respect to the resin case. Therefore, the round bar bus bar is provided with a convex portion protruding in a direction intersecting the axial direction, and the resin The current sensor assembly according to claim 1, wherein the case is provided with a concave portion that receives the convex portion from a direction intersecting the axial direction. Arranging a plurality of substantially annular shaped current sensor cores;
Forming a resin case in which the current sensor core is integrated with resin so as to have a through-hole penetrating each of the current sensor cores;
A step of penetrating and positioning a plurality of round bar bus bars having a circular cross section with respect to each of the through holes provided in the resin case;
Applying a terminal to each of the round bar bus bars;
Attaching a current sensor element to a predetermined position of the current sensor core;
A method for assembling a current sensor assembly. After positioning the round bar bus bar with respect to the resin case,
5. The method of assembling a current sensor assembly according to claim 4, further comprising a step of bending each round bar bus bar.

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