Motor controller

Abstract

To provide a motor controller capable of accurately measuring current values of a bus bar irrespective of space saving configuration, and capable of being miniaturized.SOLUTION: A motor controller comprises: a plurality of bus bars 30 arranged side by side in a Y-direction and extending in an X-direction orthogonal to the Y-direction; a sensor 70 measuring current value of at least one bus bar 30 of the plurality of bus bars 30; and a magnetic shield 80 arranged between a U-phase bus bar 51 to be measured by the sensor 70 from among the plurality of bus bars 30 and a V-phase bus bar 52 adjacent to the U-phase bus bar 51 from among the plurality of bus bars 30. The sensor 70 and the magnetic shield 80 are arranged side by side in the X-direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a motor control device. [Background technology]

[0002] To accurately control a motor, a sensor (detection element) is used to measure the current value of the bus bar. Among these types of sensors, there is known one that includes a core, which is a magnetic material that surrounds the sensor and the bus bar, separate from the sensor. The sensor detects the magnitude of the magnetic field formed in the core (see, for example, Patent Documents 1 and 2).

[0003] According to Patent Documents 1 and 2, the core and sensor are provided on the bus bar where the current is measured. This poses a problem in that sufficient space is required around the bus bar for the core and sensor. Therefore, coreless current measurement is being used to save space as motor control devices become more compact.

[0004] Coreless current measurement tends to detect smaller magnetic fluxes than core-based current measurement, so it is desirable to suppress the effects of external disturbances. For this reason, a method has been proposed in which the busbar to be measured and the sensor are surrounded by a highly magnetic shield. This prevents the disturbance magnetic flux from busbars that are not being measured, allowing busbar current measurement without using a core. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-148513 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-171156 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above-described conventional configuration, magnetic flux flows into the magnetic shield. This magnetic flux needs to be accurately detected by the sensor. Therefore, if the magnetic shield is not positioned appropriately relative to the sensor, part of the magnetic flux flowing inside the magnetic shield will not contribute to the sensor's detection and will simply be leakage flux. As a result, the amount of magnetic flux detected by the sensor will decrease. Therefore, there was a problem in that the busbar current value could not be accurately measured depending on the position of the magnetic shield relative to the sensor.

[0007] Therefore, the present invention provides a motor control device that can be made compact while easily and accurately measuring the current value of the bus bar even in a space-saving manner. [Means for solving the problem]

[0008] In order to solve the above problem, in a first aspect of the present invention, a motor control device includes a plurality of bus bars aligned in a first direction and extending in a second direction perpendicular to the first direction, a sensor that measures a current value of at least one of the plurality of bus bars, a first bus bar among the plurality of bus bars that is measured by the sensor, and a magnetic shield that is arranged between the first bus bar and a second bus bar among the plurality of bus bars adjacent to the first bus bar, wherein the sensor and the magnetic shield are arranged side by side in the first direction.

[0009] With this configuration, the magnetic shield can prevent magnetic flux generated around the second bus bar from flowing to the first bus bar. This prevents the magnetic flux around the second bus bar from disturbing the sensor that measures the current value of the first bus bar. Furthermore, there is no need to surround the sensor and the bus bar with a magnetic shield. This allows the motor control device to be easily and accurately measured while still being compact, without requiring the sensor to be positioned with high precision relative to the magnetic shield.

[0010] A second aspect of the present invention is a motor control device according to the first aspect, further comprising a substrate on which switching elements are mounted, and a plurality of the bus bars are mounted on the substrate, the plurality of bus bars including a plurality of input bus bars for supplying power from an external power source to the substrate and a plurality of output bus bars for supplying power from the substrate to the motor, and the first bus bar and the second bus bar may be the output bus bars.

[0011] This configuration makes it possible to accurately measure the current value immediately before it is supplied to the motor, thereby enabling the motor control device to be miniaturized and to perform highly accurate drive control of the motor using the motor control device.

[0012] A third aspect of the present invention is a motor control device according to the first or second aspect, wherein the output bus bars have a three-phase structure and are arranged continuously in a line in the first direction, the magnetic shield is provided between a central bus bar located in the center of the output bus bars and the output bus bars located on both sides of the central bus bar, and the sensor measures the current values ​​of the output bus bars located on both sides of the central bus bar.

[0013] With this configuration, even in the case of a three-phase output busbar, the current values ​​of two of the three busbars can be accurately measured. Furthermore, the current value of the remaining busbar can be accurately estimated from the two measured current values. In this way, the current values ​​of each output busbar in the three-phase structure can be accurately measured while minimizing the number of magnetic shields. Therefore, the motor control device can perform highly accurate drive control of the motor.

[0014] A fourth aspect of the present invention is the motor control device of any one of the first to third aspects, wherein the magnetic shield may have a base portion and a pair of side walls arranged on both sides of the base portion in a width direction.

[0015] This configuration allows a magnetic shield to be provided around the busbar. This simultaneously prevents magnetic flux from flowing from the busbar on which the magnetic shield is placed, where the current value is not measured, to the busbars on either side of the busbar on which the current value is not measured. Furthermore, a magnetic path can be easily formed around the busbar on which the current value is not measured. This allows for accurate current measurement while miniaturizing the motor control device. Because the magnetic shield is U-shaped, the open side of the magnetic shield faces the busbar, making it easy to assemble the magnetic shield around the busbar.

[0016] A fifth aspect of the present invention is the motor control device according to any one of the first to fourth aspects, wherein the magnetic shield may be made of a high magnetic permeability material.

[0017] This configuration allows magnetic flux around the busbar on which the magnetic shield is placed to easily pass through the magnetic shield. This more reliably prevents magnetic flux from flowing from the busbar on which the magnetic shield is placed and whose current value is not measured to the adjacent busbars on either side of the busbar on which the current value is not measured. This allows for more accurate current measurement while miniaturizing the motor control device. [Effects of the Invention]

[0018] According to the present invention, a motor control device that can be miniaturized while accurately measuring the current value of a bus bar even in a space-saving manner is provided. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view showing a motor control device according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view of a motor control device according to an embodiment of the present invention; [Figure 3] FIG. 3 is a view taken along the arrow III in FIG. [Figure 4] FIG. 2 is a perspective view of an input bus bar according to an embodiment of the present invention. [Figure 5]FIG. 2 is a perspective view of an output bus bar according to an embodiment of the present invention. [Figure 6] 1A and 1B are diagrams showing the arrangement of busbars, sensors, and magnetic shields in an embodiment of the present invention, in which (a) is the arrangement when current measurements are made on input and output busbars with input busbars placed at both ends, (b) is the arrangement when current measurements are made on output busbars with input busbars placed at both ends, and (c) is the optimal arrangement when there are no restrictions on busbar placement and current measurements are made on input and output busbars. DETAILED DESCRIPTION OF THE INVENTION

[0020] Next, an embodiment of the present invention will be described with reference to the drawings.

[0021] <Motor control device> Fig. 1 is a perspective view showing a motor control device 1. For ease of understanding, Fig. 1 shows second printed circuit board 22 of printed circuit boards 21 and 22 (first printed circuit board 21 and second printed circuit board 22) in a see-through manner. Fig. 2 is an exploded perspective view of the motor control device 1.

[0022] 1 and 2, the motor control device 1 has an inverter function that converts DC power supplied from a battery (not shown) into AC power and drives an AC motor (not shown) with the converted AC power. The motor control device 1 includes a case 10, plate-shaped printed circuit boards 21 and 22 housed in the case 10, a plurality of bus bars 30 (for example, five in this embodiment) provided on the corresponding printed circuit boards 21 and 22, a plurality of sensors 70 (for example, three in this embodiment), and a magnetic shield 80.

[0023] Each of the printed circuit boards 21, 22 has a rectangular shape when viewed in the thickness direction. The printed circuit boards 21, 22 are arranged opposite each other in the thickness direction. In the following description, the two perpendicular sides of the printed circuit boards 21, 22 are referred to as the X direction and the Y direction, respectively. The opposing direction of the printed circuit boards 21, 22 is referred to as the Z direction. Of the printed circuit boards 21, 22, the first printed circuit board 21 side is referred to as the lower side in the Z direction. Of the printed circuit boards 21, 22, the second printed circuit board 22 side is referred to as the upper side in the Z direction. The upper and lower directions in the Z direction are simply referred to as the upper side and the lower side, respectively.

[0024] <Case> The case 10 has a box-shaped main body 11 with one open side. The case 10 houses printed circuit boards 21 and 22, a bus bar 30, a sensor 70, and a magnetic shield 80 together with a case cover (not shown) that closes the opening of the main body 11. A first printed circuit board 21 is disposed on the bottom wall of the main body 11. The vertical direction of the printed circuit boards 21 and 22 coincides with the direction in which the bottom wall and opening of the main body 11 face each other. In addition to the main body 11, the case 10 also includes a terminal base 12 provided at one end 11a of the main body 11 in the X direction, and a terminal cover 14 that covers the terminal base 12. A plurality of heat dissipation fins 15 are provided on the outer surface 11d of the main body 11. Hereinafter, the heat dissipation fins 15 may be referred to as "heat dissipation fins 15."

[0025] The terminal base portion 12 is plate-shaped and extends in the Y direction. The terminal base portion 12 is provided at one end 11a of the main body portion 11 across the entire Y direction. Fixed portions 12a that bend toward the Z direction are formed at both ends of the terminal base portion 12 in the Y direction. The fixed portions 12a of the terminal base portion 12 engage with engaging claws 11c provided on the side surfaces 11b of the main body portion 11, thereby fixing the terminal base portion 12 to the main body portion 11. Fixation between the fixed portions 12a and the engaging claws 11c is a so-called snap fit fixation.

[0026] A plurality of (for example, five in this embodiment) rectangular busbar holding grooves 12c are formed on the surface 12d of the terminal base portion 12 opposite the heat dissipation fins 15 when viewed from the Z direction. The busbar holding grooves 12c are formed in a line at equal intervals in the Y direction of the terminal base portion 12. The busbar holding grooves 12c hold the busbars 30 by providing them therein. A regular hexagonal recess 12b is formed at the bottom of each busbar holding groove 12c. A terminal fastener 13 for fastening a terminal is disposed in each recess 12b.

[0027] The terminal fixture 13 secures the terminal of a cable connecting the motor control device 1 to an external device (e.g., a battery or a motor) to the bus bar 30. In this embodiment, a bolt is used for the terminal fixture 13. A head 13a of the terminal fixture 13 (bolt) is fitted into a recess 12b of the terminal base 12. A threaded portion 13b of the terminal fixture 13 (bolt) is arranged to face upward in the Z direction from the terminal base 12. The terminal base 12 and the terminal fixture 13 are covered with a terminal cover 14 to prevent the intrusion of water, dust, and the like from the outside when the bus bar 30 and the cable are connected. The terminal cover 14 secures the terminal fixture 13 by sandwiching it between the terminal base 12 and the terminal base 12 in the Z direction.

[0028] The heat dissipation fins 15 are arranged, for example, at intervals in the Y direction on the outer surface 11d of the main body 11. The heat dissipation fins 15 extend along the X direction of the main body 11. The heat dissipation fins 15 protrude outward in the Z direction from the outer surface 11d of the main body 11. The heat dissipation fins 15 dissipate heat generated inside the motor control device 1, such as from the printed circuit boards 21 and 22 and the bus bar 30, to the outside of the case 10.

[0029] <Printed circuit board> The first printed circuit board 21 is fixed to the main body 11 of the case 10. The first printed circuit board 21 is a PWB (Printed Wiring Board) on which a plurality of switching elements 23 are surface-mounted. The ON / OFF operation of the switching elements 23 is controlled by a switching control circuit (not shown), thereby operating the motor control device 1 under optimal conditions according to the driving state of the AC motor. A plurality of bus bars 30 are mounted on the first printed circuit board 21.

[0030] The second printed circuit board 22 is provided above the first printed circuit board 21 via a plurality of spacers 24. The circuit formed on the second printed circuit board 22 is electrically connected to the circuit formed on the first printed circuit board 21 by a plurality of conductive pins 25. A sensor 70 is mounted on the second printed circuit board 22. A magnetic shield 80 is provided on the second printed circuit board 22.

[0031] <Busbar> Fig. 3 is a view taken along the arrow III in Fig. 1. Fig. 3 shows a state in which the case 10 has been removed for ease of explanation.

[0032] As shown in FIGS. 1 to 3 , five bus bars 30 are mounted on the top surface 21a of the first printed circuit board 21, which faces the second printed circuit board 22. The five bus bars 30 are arranged side by side in the Y direction. The five bus bars 30 are formed by pressing a strip of conductive material that is long in the X direction. More specifically, the five bus bars 30 include two input bus bars 31 for supplying power from an external power source to the printed circuit boards 21 and 22, and three output bus bars 50 for supplying power from the printed circuit boards 21 and 22 to the motor. One end of the bus bars 30 is fixed to the first printed circuit board 21, and the other end is fixed to the terminal base 12.

[0033] The input bus bar 31 supplies DC current from, for example, an external power supply to the printed circuit boards 21 and 22. The input bus bar 31 is arranged at both ends of the five bus bars 30 arranged in parallel in the Y direction. One of the input bus bars 31 is a positive bus bar 32, and the other is a negative bus bar 33. The positive bus bar 32 and the negative bus bar 33 have the same configuration. Therefore, in the following description, when distinguishing between the positive bus bar 32 and the negative bus bar 33, the same reference numerals are used to designate the same configuration, and the positive bus bar 32 is distinguished by adding a "P" to the end of the reference numeral, and the negative bus bar 33 is distinguished by adding an "N" to the end of the reference numeral. In the following description, the positive bus bar 32 will be described, and a description of the negative bus bar 33 will be omitted.

[0034] FIG. 4 is a perspective view of the input bus bar 31. As shown in FIG. As shown in FIG. 4, the positive bus bar 32 (input bus bar 31) includes an external terminal connection portion 34P formed in a rectangular shape that is long in the X direction, a first bent portion 35P extending from one end of the external terminal connection portion 34P, a body portion 36P extending from the end of the first bent portion 35P opposite the external terminal connection portion 34P, a second bent portion 37P extending from the end of the body portion 36P opposite the first bent portion 35P, and a substrate fixing portion 38P extending in the X direction from the end of the second bent portion 37P opposite the body portion 36P.

[0035] The external terminal connection portion 34P comes into contact with a terminal of a cable connected to an external power supply and is electrically connected to the external power supply. The external terminal connection portion 34P is disposed in a busbar holding groove 12c formed in the terminal base portion 12. A circular first fixing hole 41P penetrating the external terminal connection portion 34P in the plate thickness direction is formed in the external terminal connection portion 34P. The screw portion 13b of the terminal fixture 13 is inserted into the first fixing hole 41P. In other words, the screw portion 13b is inserted into the first fixing hole 41P and the external terminal connection portion 34P is fitted into the busbar holding groove 12c, thereby fixing the positive busbar 32 to the terminal base portion 12. The first bent portion 35P is bent and extends upward in the Z direction from one end of the external terminal connection portion 34P. The first bent portion 35P is formed to have a smaller plate width than the external terminal connection portion 34P. The first bent portion 35P is disposed between the terminal base portion 12 and the printed circuit boards 21 and 22 in the X direction. The length of the first bent portion 35P is formed to be a length that brings the body portion 36P between the first printed circuit board 21 and the second printed circuit board 22 and closer to the second printed circuit board 22.

[0036] The body portion 36P extends in the X direction from the end of the first bent portion 35P on the opposite side to the external terminal connection portion 34P. The body portion 36P includes a first body portion 39P on the first bent portion 35P side and a second body portion 40P on the second bent portion 37P side. The first body portion 39P is formed to have the same plate width as the first bent portion 35P. The second body portion 40P is formed to have a plate width greater than that of the first body portion 39P. The second bent portion 37P extends downward in the Z direction from the end of the body portion 36P, and is further bent and extends in the X direction on the opposite side of the body portion 36P. The second bent portion 37P is formed to have the same plate width as the second body portion 40P. The second bent portion 37P is formed to have a longer length in the Z direction than the first bent portion 35P. The board fixing portion 38P is formed to have the same plate width as the second bent portion 37P.

[0037] The end of the board fixing portion 38P opposite the second bent portion 37P is formed in a semicircular shape. A circular second fixing hole 42P is formed in the board fixing portion 38P, penetrating in the board thickness direction. A board fixing bolt 26 for fixing the bus bar 30 and the first printed circuit board 21 is inserted into the second fixing hole 42P. A resin washer 27 and a metal washer 28 are provided between the board fixing bolt 26 and the board fixing portion 38P. That is, of the positive bus bar 32, the board fixing portion 38P is fixed to the first printed circuit board 21 by the board fixing bolt 26, with the resin washer 27 and the metal washer 28 sandwiched between them.

[0038] The output busbar 50 supplies AC current from the printed circuit boards 21 and 22 to a three-phase motor, for example. The output busbar 50 is sandwiched between the input busbars 31 arranged at both ends of the five busbars 30 arranged in parallel on the first printed circuit board 21. The output busbar 50 has a three-phase structure and includes a U-phase busbar 51, a V-phase busbar 52, and a W-phase busbar 53. The output busbars 50 have the same configuration. Therefore, in the following description, when distinguishing between the U-phase busbar 51, the V-phase busbar 52, and the W-phase busbar 53, the same reference numerals are used to designate the same components, and the suffixes "U," "V," and "W" are added to distinguish them, respectively.

[0039] In the following explanation, only the U-phase busbar 51 will be described, and explanations of the V-phase busbar 52 and the W-phase busbar 53 will be omitted. The output busbar 50 has a basic configuration similar to that of the input busbar 31. Therefore, explanations of configurations similar to those of the input busbar 31 will be omitted as appropriate.

[0040] FIG. 5 is a perspective view of the output bus bar 50. As shown in FIG. As shown in FIG. 5, the U-phase bus bar 51 (output bus bar 50) includes an external terminal connection portion 54U formed in a rectangular shape that is long in the X direction, a first bent portion 55U extending from one end of the external terminal connection portion 54U, a body portion 56U extending from the end of the first bent portion 55U opposite the external terminal connection portion 54U, a second bent portion 57U extending from the end of the body portion 56U opposite the first bent portion 55U, and a substrate fixing portion 58U extending in the X direction from the end of the second bent portion 57U opposite the body portion 56U.

[0041] The configurations of the external terminal connection portion 54U and the first bent portion 55U are similar to those of the external terminal connection portion 34P of the positive bus bar 32. A circular first fixing hole 61U is formed in the external terminal connection portion 54U, penetrating in the plate thickness direction, similar to that of the positive bus bar 32. The body portion 56U of the U-phase bus bar 51 is formed so that its length in the X direction is shorter than that of the body portion 36P of the positive bus bar 32. The body portion 56U and the second bent portion 57U of the U-phase bus bar 51 are formed so that their plate widths are similar to those of the first bent portion 55U. Board fixing portion 58U is formed with a width greater than second bent portion 57U, and is formed similarly to board fixing portion 38P of positive bus bar 32. A circular second fixing hole 62U is formed in board fixing portion 58U, penetrating in the thickness direction. Like positive bus bar 32, U-phase bus bar 51 is fixed to first printed circuit board 21 with board fixing bolts 26, with resin washer 27 and metal washer 28 sandwiched between them.

[0042] In this embodiment, the bus bars 30 are arranged in the Y direction in the following order: negative bus bar 33, U-phase bus bar 51, V-phase bus bar 52, W-phase bus bar 53, and positive bus bar 32. Body portions 36P, 36N, 56U, 56V, and 56W of the five bus bars 30 are arranged so that their heights in the Z direction from the upper surface 21a of the first printed circuit board 21 are the same.

[0043] <Sensor> The sensor 70 measures the current value of the busbar 30. The sensor 70 is, for example, a Hall IC. The sensor 70 amplifies a Hall voltage generated in response to magnetic flux detected by a Hall element built into the IC, and calculates the current value by processing the signal in an internal circuit of the IC. In this embodiment, the sensor 70 measures the current values ​​of the negative busbar 33, the U-phase busbar 51, and the W-phase busbar 53. Each sensor 70 is provided on the underside 22a of the second printed circuit board 22 facing the first printed circuit board 21, and is arranged above the first body portion 39N of the negative busbar 33, the body portion 56U of the U-phase busbar 51, and the body portion 56W of the W-phase busbar 53.

[0044] <Magnetic shield> The magnetic shield 80 is provided on the lower surface 22a of the second printed circuit board 22 and is arranged above the body portion 56V of the V-phase bus bar 52. The magnetic shield 80 and the sensor 70 are arranged side by side in the Y direction. The magnetic shield 80 is made of a plate-shaped high-permeability material. The magnetic shield 80 includes a base portion 81 extending in the Y direction and a pair of side walls 82, 83 extending in the Z direction from both ends of the base portion 81. In other words, the magnetic shield 80 is formed in a U-shape. The magnetic shield 80 is arranged with an opening 84 facing downward.

[0045] Magnetic shield 80 has base portion 81 fixed to second printed circuit board 22. Base portion 81 is fixed to second printed circuit board 22 with, for example, an adhesive or bolts and nuts. Body portion 56V of V-phase bus bar 52 is disposed in opening 84. In other words, magnetic shield 80 is disposed so as to surround the periphery of body portion 56V of V-phase bus bar 52. <Actions and Effects>

[0046] Next, the functions and effects of the bus bar 30, the sensor 70, and the magnetic shield 80 of the motor control device 1 according to this embodiment will be described. When a DC current is supplied from an external power supply via input bus bar 31, motor control device 1 according to this embodiment supplies an AC current via output bus bar 50 to drive the AC motor. At this time, the current value of bus bar 30 measured by sensor 70 is used to drive the AC motor under optimal conditions according to the driving state of the AC motor.

[0047] Because the sensor 70 and the magnetic shield 80 are arranged side by side in the Y direction, the magnetic flux around the V-phase bus bar 52 can be prevented from flowing toward the adjacent U-phase bus bar 51 and W-phase bus bar 53. This prevents the magnetic flux around the V-phase bus bar 52 from becoming a disturbance to the sensors 70 that measure the current values ​​of the U-phase bus bar 51 and the W-phase bus bar 53. Furthermore, it is not necessary to surround the U-phase bus bar 51, the W-phase bus bar 53, and the sensor 70 with the magnetic shield 80. As a result, the motor control device 1 can be easily and accurately measured for the current values ​​of the U-phase bus bar 51 and the W-phase bus bar 53 without requiring high precision placement of the sensor 70 relative to the magnetic shield 80, while still allowing for a reduction in size of the motor control device 1.

[0048] This also makes it possible to miniaturize the motor control device 1 while controlling the motor with high precision, which will contribute to Goal 7 of the United Nations-led Sustainable Development Goals (SDGs): "Ensure access to affordable, reliable, sustainable and modern energy for all," Goal 9: "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation," and Goal 12: "Ensure sustainable consumption and production patterns."

[0049] Each sensor 70 measures the current value of the U-phase busbar 51 and the W-phase busbar 53, which are among the output busbars in the three-phase configuration. The magnetic shield 80 is disposed so as to surround the V-phase busbar 52 (center busbar), which is located in the center of the output busbars. This allows the current values ​​of the U-phase busbar 51 and the W-phase busbar 53 to be accurately measured immediately before the current is supplied to the motor. Furthermore, the current value of the V-phase busbar 52, whose current is not measured, can be accurately estimated from the accurately measured current values ​​of the U-phase busbar 51 and the W-phase busbar 53. In this way, the current value of the three-phase output busbar 50 can be accurately measured and estimated while minimizing the number of magnetic shields 80. As a result, the motor control device 1 can be downsized while providing high-precision drive control of the motor.

[0050] The magnetic shield 80 has a base 81 extending in the Y direction and a pair of side walls 82, 83 extending in the Z direction from both ends of the base 81 in the Y direction. That is, the magnetic shield 80 is formed in a U-shape. This allows the magnetic shield 80 to be provided so as to surround the periphery of the V-phase bus bar 52. This simultaneously prevents magnetic flux from flowing around the V-phase bus bar 52 to the adjacent U-phase bus bar 51 and W-phase bus bar 53. This also makes it easy to form a magnetic path around the V-phase bus bar 52. This allows the motor control device 1 to be miniaturized while accurately measuring the current value of the bus bar 30. Furthermore, by orienting the opening 84 of the magnetic shield 80 toward the bus bar 30, the magnetic shield 80 can be easily assembled around the bus bar 30.

[0051] The magnetic shield 80 is made of a highly magnetically permeable material. Therefore, magnetic flux around the busbar 30 on which the magnetic shield 80 is placed easily passes through the magnetic shield 80. This more reliably prevents magnetic flux from flowing from a busbar 30 whose current is not being measured to the busbars 30 located on either side of the busbar 30 whose current is not being measured. This allows the motor control device 1 to be more compact while more accurately measuring the current value.

[0052] Next, a first modified example and a second modified example of the above-described embodiment will be described with reference to FIG. 6. FIG. 6 is a diagram showing the arrangement of the bus bar 30, the sensor 70, and the magnetic shield 80 in the embodiment. In FIG. 6, the frame indicates the bus bar. - ", "B + " represent the negative bus bar 33 and the positive bus bar 32, respectively, and "U", "V", and "W" represent the U-phase bus bar 51, the V-phase bus bar 52, and the W-phase bus bar 53, respectively. Furthermore, a plain frame represents a bus bar 30 without a sensor 70 and a magnetic shield 80, a frame hatched with dots represents a bus bar 30 with a sensor 70 for measuring current, and a frame hatched with parallel diagonal lines represents a bus bar 30 with a magnetic shield 80 provided around it.

[0053] For example, FIG. 6(a) shows the arrangement of the above-described embodiment, with input bus bars 31 arranged at both ends. Sensors 70 are provided for the negative bus bar 33, U-phase bus bar 51, and W-phase bus bar 53, respectively, to measure the current values ​​of each bus bar 30. A magnetic shield 80 is provided for the V-phase bus bar 52. In the following description, parts that are the same as the components in the above-described embodiment are given the same reference numerals, and their description will be omitted. In the first and second modified examples, only the different parts will be described.

[0054] [First Modification] First, a first modified example will be described with reference to FIG. 6(b). FIG. 6(b) illustrates an arrangement in which input busbars 31 are arranged at both ends of busbars 30 arranged side by side in the X direction, and current measurement is performed only on the output busbar 50. The first modified example differs from the above-described embodiment in the arrangement of the sensor 70 and the magnetic shield 80. Furthermore, in the first modified example, the current value of the input busbar 31 is not measured. Specifically, as shown in FIG. 6(b), the sensor 70 is provided for each of the U-phase busbar 51 and the W-phase busbar 53 among the output busbars 50. The magnetic shield 80 is provided for each of the negative busbar 33, the positive busbar 32, and the V-phase busbar 52. In other words, the magnetic shields 80 and the sensors 70 are arranged alternately. In this case, the motor control device 1 performs motor control using current value information obtained from the battery that supplies power to the motor control device 1.

[0055] With this configuration, magnetic shields 80 are provided for the negative bus bar 33 and the V-phase bus bar 52 on both sides of the U-phase bus bar 51 whose current is to be measured, thereby preventing magnetic flux from flowing from the negative bus bar 33 and the V-phase bus bar 52. Similarly, magnetic shields 80 are provided for the V-phase bus bar 52 and the positive bus bar 32 on both sides of the W-phase bus bar 53 whose current is to be measured, thereby preventing magnetic flux from flowing from the V-phase bus bar 52 and the positive bus bar 32. This allows the current value of the output bus bar 50 to be accurately measured while minimizing the number of sensors 70. As a result, the motor control device 1 can be miniaturized while providing high-precision drive control of the motor.

[0056] [Second Modification] Next, a second modified example will be described with reference to FIG. 6(c). FIG. 6(c) shows an optimal arrangement for measuring the currents of the input busbars 31 and the output busbars 50 without any restrictions on the arrangement of the busbars 30. The second modified example differs from the above-described embodiment in the arrangement of the input busbars 31 and the output busbars 50 and the arrangement of the sensors 70 and the magnetic shields 80. In the second modified example, the current value of the input busbar 31 is measured. In the second modified example, the busbars 30 are arranged in the following order: negative busbar 33, positive busbar 32, U-phase busbar 51, V-phase busbar 52, and W-phase busbar 53. The sensors 70 are provided for the negative busbar 33, U-phase busbar 51, and W-phase busbar 53, respectively. The magnetic shields 80 are provided for the positive busbars 32 and V-phase busbar 52, respectively. In other words, the sensors 70 and the magnetic shields 80 are arranged alternately. With this configuration, even if there is no restriction on the arrangement of the bus bars 30 mounted on the first printed circuit board 21, the current values ​​of the input bus bar 31 and the output bus bar 50 can be measured accurately.

[0057] The present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described embodiment without departing from the spirit of the present invention. For example, in the above-described embodiment and modified examples, the bus bars 30 are arranged in the following order: negative bus bar 33, U-phase bus bar 51, V-phase bus bar 52, W-phase bus bar 53, and positive bus bar 32. However, this is not a limitation, and if there are no restrictions on the arrangement on printed circuit boards 21 and 22, the bus bars 30 may be arranged in any order. In this case, a magnetic shield 80 may be provided for the bus bars 30 for which current is to be measured, adjacent to the bus bars 30 for which current is to be measured, so that the magnetic flux around the bus bars 30 for which current is not to be measured does not disturb the sensor 70. Even with this configuration, the same effects as those of the above-described embodiment and modified examples can be achieved.

[0058] In the above-described embodiment and modified examples, the heights of the first bent portions 35P, 35N of the input bus bar 31 are similar to the heights of the first bent portions 55U, 55V, and 55W of the output bus bar 50. Similarly, the heights of the second bent portions 37P, 37N of the input bus bar 31 are similar to the heights of the second bent portions 57U, 57V, and 57W of the output bus bar 50. However, this is not limited thereto. When the current value of the input bus bar 31 is not measured, the heights of the first bent portions 35P, 35N and the second bent portions 37P, 37N of the input bus bar 31 may be smaller than the heights of the first bent portions 55U, 55V, and 55W and the second bent portions 57U, 57V, and 57W of the output bus bar 50.

[0059] With this configuration, the body portions 36P, 36N of the input busbar 31, for which current is not measured, can be moved away in the Z direction from the body portions 56U, 56W of the output busbar 50, for which current is to be measured. This reduces the effect of magnetic flux formed around the input busbar 31 on the sensor 70. This allows the current value of the output busbar 50 to be accurately measured without providing a magnetic shield 80 on the input busbar 31.

[0060] In the above-described embodiment and modified examples, the magnetic shield 80 is formed in a U-shape. However, this is not limited thereto, and the magnetic shield 80 may be provided between a busbar 30 for which current is to be measured and a busbar 30 adjacent to the busbar 30 for which current is not to be measured so that magnetic flux generated around the busbar 30 for which current is not to be measured does not disturb the sensor 70. For example, the magnetic shield may be a plate-like wall or L-shaped. Even with such a configuration, the same effects as those of the above-described embodiment and modified examples can be achieved.

[0061] In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and variations may be combined as appropriate, as long as this does not deviate from the spirit of the present invention. [Explanation of symbols]

[0062] 1...motor control device, 10...case, 11...main body, 11a...one end, 11b...side surface, 11c...engagement claw, 11d...outer surface, 12...terminal base, 12a...fixing portion, 12b...recess, 12c...busbar holding groove, 12d...surface, 13...terminal fixing device, 13a...head, 13b...screw portion, 14...terminal cover, 15...fin (heat dissipation fin), 21...first printed circuit board (printed circuit board), 21a...top surface, 22...second Printed circuit board (printed circuit board), 22a...underside, 23...switching element, 24...spacer, 25...pin, 26...board fixing bolt, 27 resin washer, 28...metal washer, 30...bus bar, 31...input bus bar, 32...positive bus bar (first bus bar, second bus bar), 33...negative bus bar (first bus bar, second bus bar), 34P, 34N...external terminal connection portion, 35P, 35N...first bend portion , 36P, 36N...body portion, 37P, 37N...second bending portion, 38P, 38N...board fixing portion, 39P, 39N...first body portion, 40P, 40N...second body portion, 41P, 41N...first fixing hole, 42P, 42N...second fixing hole, 50...output bus bar, 51...U-phase bus bar (first bus bar, second bus bar), 52...V-phase bus bar (first bus bar, second bus bar, center bus bar), 53...W-phase bus bar (first bus bar, bus bar, second bus bar), 54U, 54V, 54W... external terminal connection portion, 55U, 55V, 55W... first bent portion, 56U, 56V, 56W... body portion, 57U, 57V, 57W... second bent portion, 58U, 58V, 58W... board fixing portion, 61U, 61V, 61W... first fixing hole, 62U, 62V, 62W... second fixing hole, 70... sensor, 80... magnetic shield, 81... base portion, 82, 83... side wall, 84... opening

Claims

1. A plurality of bus bars aligned in a first direction and extending in a second direction perpendicular to the first direction; A sensor that measures a current value of at least one of the bus bars; a magnetic shield disposed between a first bus bar among the plurality of bus bars that is measured by the sensor and a second bus bar among the plurality of bus bars that is adjacent to the first bus bar; Equipped with The sensor and the magnetic shield are arranged side by side in the first direction. A motor control device comprising:

2. A substrate on which a switching element is mounted is provided, A plurality of the bus bars are mounted on the substrate, The plurality of bus bars include a plurality of input bus bars for supplying power to the board from an external power source; a plurality of output bus bars for supplying power from the substrate to a motor; Including, the first bus bar and the second bus bar are the output bus bars; 2. The motor control device according to claim 1 .

3. The output bus bars have a three-phase structure and are arranged continuously in the first direction. the magnetic shield is provided between a central bus bar located at a center of the output bus bars and the output bus bars located on both sides of the central bus bar, The sensor measures a current value of the output busbars located on both sides of the central busbar.

3. The motor control device according to claim 2.

4. The magnetic shield includes: A base portion; A pair of side walls arranged on both sides of the base portion in a width direction; It has 4. The motor control device according to claim 1, wherein the motor control device comprises:

5. The magnetic shield is made of a high magnetic permeability material.

4. The motor control device according to claim 1, wherein the motor control device comprises:

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