Power supply unit

Abstract

To provide a power supply unit that suppresses the influence of noise generated inside a housing case.SOLUTION: A battery pack 11 includes a battery monitoring device 30 that transmits and receives battery information through wireless communication, a battery control device 40, a junction box 60 that generates electromagnetic noise, and an ECU case 45 that houses the battery control device 40. The junction box 60 is fixed to the underside of the ECU case 45, and the battery control device 40 and the junction box 60 are both placed within a battery housing space of the battery pack 11, with an electromagnetic wave shield 201 interposed between the battery control device 40 and the junction box 60. The fixing surface of the junction box 60 that constitutes the ECU case 45 serves as the electromagnetic wave shield 201.SELECTED DRAWING: Figure 17

Description

Technical Field

[0006] , ,

[0005] , ,

[0001] The present disclosure relates to a power supply unit.

Background Art

[0002] In recent years, there has been a battery monitoring system that transmits or receives the battery state of a battery cell by wireless communication. Such a battery monitoring system is described in, for example, Patent Document 1.

[0003] A battery monitoring system that uses such wireless communication is affected by electromagnetic wave noise in communication. Therefore, an electromagnetic wave blocking member that absorbs or reflects external electromagnetic wave noise is used in the housing case in which the battery monitoring system is housed. As a document describing the use of an electromagnetic wave absorbing member in a housing case, for example, it is described in Patent Document 2.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the source of electromagnetic wave noise (noise source) does not always exist outside the housing case, and may exist inside the housing case. For example, as a main noise source existing inside the housing case, there is a junction box having a relay switch or the like and performing connection switching of current. Therefore, when using wireless communication inside the housing case, it is necessary to suppress the influence of electromagnetic wave noise from the noise source inside the housing case.

[0006] This invention has been made in view of the above circumstances, and its main purpose is to provide a power supply unit that suppresses the effects of noise generated inside the housing case. [Means for solving the problem]

[0007] A power supply unit for solving the above problems is a power supply unit having a battery section, comprising a plurality of wireless devices that transmit and receive battery information by wireless communication, a noise source that generates electromagnetic noise, and a housing that houses the battery section or the wireless devices, wherein the noise source is fixed to the outside of the housing, and both the plurality of wireless devices and the noise source are arranged within the battery housing space of the power supply unit, and an electromagnetic wave shielding member is interposed between the wireless devices and the noise source, and the fixed surface of the noise source that constitutes the housing is the electromagnetic wave shielding member.

[0008] This makes it possible to suppress the impact of noise from the noise source on the wireless device. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic diagram of the vehicle's configuration. [Figure 2] A block diagram showing the configuration of the battery pack. [Figure 3] A diagram showing the inside of a battery pack. [Figure 4] Perspective view of the storage case. [Figure 5] A side cross-sectional view showing the inside of the battery monitoring device. [Figure 6] A diagram showing the configuration of the wireless antenna on the slave unit. [Figure 7] A diagram showing the projection plane of the wireless antenna on the slave unit. [Figure 8] A schematic diagram showing the change in capacitance in the comparative example. [Figure 9] A diagram schematically showing the change in capacitance in the first embodiment. [Figure 10] A side view showing the inside of the battery monitoring device in a modified example. [Figure 11]Perspective view showing a battery monitoring device in a modified example. [Figure 12] Perspective view showing an element in a modified example. [Figure 13] Perspective view showing a ground plate in a modified example. [Figure 14] Perspective view showing a slave unit side wireless antenna in a modified example. [Figure 15] View showing a metal plate in a modified example. [Figure 16] Top view showing the inside of a battery pack in the second embodiment. [Figure 17] Side view showing the inside of a battery pack in the second embodiment. [Figure 18] Perspective view showing an ECU case in the second embodiment. [Figure 19] Top view showing the inside of a battery pack in a modified example. [Figure 20] (a) is a top view showing the inside of a battery pack in a modified example, (b) is a side view showing the inside of a battery pack in a modified example. [Figure 21] (a) is a top view showing the inside of a battery pack in a modified example, (b) is a side view showing the inside of a battery pack in a modified example. [Figure 22] (a) is a top view showing the inside of a battery pack in a modified example, (b) is a side view showing the inside of a battery pack in a modified example. [Figure 23] (a) is a side view showing the inside of a battery pack in a modified example, (b) is a side view showing the inside of a battery pack in a modified example. [Figure 24] Top view showing the inside of a battery pack in a modified example. [Figure 25] Top view showing the inside of a battery pack in a modified example. [Figure 26] Top view showing the inside of a battery pack in a modified example. [Figure 27] Top view showing the inside of a battery pack in a modified example. [Figure 28] Top view showing the inside of a battery pack in a modified example. [Figure 29]A diagram illustrating electromagnetic shielding in a modified example. [Figure 30] A top view showing the inside of the battery pack in the third embodiment. [Figure 31] (a) is a side view showing the inside of the battery pack in the third embodiment, and (a) is a top view showing the inside of the battery pack in a modified example. [Figure 32] A top view showing the inside of the battery pack in a modified example. [Figure 33] A cross-sectional view showing the inside of the battery pack in a modified example. [Figure 34] A perspective view showing the battery block in a modified example. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the wireless device and power supply unit in this disclosure will be described in detail with reference to the drawings. In principle, the same or corresponding parts in the drawings will be denoted by the same reference numerals and their descriptions will not be repeated between each embodiment and each modification. The following description will focus on applications to vehicles, but the invention is also applicable to other uses, such as drones and other aircraft, ships, construction machinery, agricultural machinery, etc.

[0011] (First Embodiment) <Vehicle> Figure 1 is a schematic diagram showing the configuration of vehicle 10. Vehicle 10 is an electric vehicle such as an electric vehicle (EV), hybrid vehicle (HV), or plug-in hybrid vehicle (PHV). Vehicle 10 comprises a battery pack 11 (indicated as "Battery" in Figure 1), a power control unit (hereinafter referred to as "PCU") 12 as a power conversion device, a motor 13 (indicated as "MG" in Figure 1) as an electrical load, and a vehicle ECU 14 (indicated as "ECU" in Figure 1). Note that PCU is an abbreviation for "Power Control Unit," MG is an abbreviation for "Motor Generator," and ECU is an abbreviation for "Electronic Control Unit."

[0012] The battery pack 11 is mounted in the vehicle 10 as the power unit (driving power source) for the vehicle 10. In Figure 1, the battery pack 11 is located, for example, in the front compartment. However, the battery pack 11 may also be located in the rear compartment, under the seats, or under the floor.

[0013] The battery pack 11 includes a battery pack 20 (described later) and is a rechargeable DC voltage source. The battery pack 11 supplies power to the electrical load of the vehicle 10. The battery pack 11 also converts power through the PCU 12 and supplies power to the motor 13. The battery pack 11 is also charged through the PCU 12.

[0014] The PCU12 performs bidirectional power conversion between the battery pack 11 and the motor 13 according to control signals from the vehicle ECU14. The PCU12 is comprised of, for example, an inverter that converts the DC voltage from the battery pack 11 to AC voltage to drive the motor 13, and a converter that boosts the DC voltage supplied to the inverter to an output voltage higher than that of the battery pack 11.

[0015] Motor 13 is an AC rotating electric machine, for example, a three-phase AC synchronous motor with permanent magnets embedded in the rotor. Motor 13 is driven by PCU 12 to generate rotational driving force, and the driving force generated by motor 13 is transmitted to the drive wheels. On the other hand, when the vehicle 10 is braking, motor 13 operates as a generator and performs regenerative power generation. The power generated by motor 13 is supplied to the battery pack 11 through PCU 12 and stored in the battery pack 20.

[0016] The vehicle ECU 14 consists of a CPU, ROM, RAM, and input / output ports for inputting and outputting various signals. The CPU loads the program stored in ROM into RAM and executes it. The program stored in ROM contains the processing instructions for the vehicle ECU 14. As an example of the main processing of the vehicle ECU 14, it receives information such as the voltage, current, SOC (State of Charge), and SOH (State of Health) of the battery pack 20 from the battery pack 11, and controls the PCU 12 to instruct the motor 13 to be driven and the battery pack 11 to be charged and discharged.

[0017] <Battery Pack> The battery pack 11 will now be described in detail. Figure 2 is a block diagram showing the configuration of the battery pack 11, and Figure 3 is a plan view schematically showing the arrangement of various elements housed inside the battery pack 11. The battery pack 11 comprises a battery pack 20, a junction box 60, a battery monitoring system 100, and a housing case 50 (shown by a dashed line) that houses them. The battery monitoring system 100 is a system that monitors and manages the battery status of the battery pack 20 using wireless communication. The battery monitoring system 100 comprises a plurality of battery monitoring devices 30 and a battery control device 40, and wireless communication takes place between them. The battery monitoring devices 30 and the battery control device 40 each correspond to wireless devices.

[0018] In this embodiment, the battery pack 20, battery monitoring device 30, and battery control device 40 are housed inside the housing case 50 (battery housing space), but they may also be located outside the housing case 50. Alternatively, the housing case 50 may be omitted, and the battery pack 20 and battery monitoring system 100 may be directly attached to a battery housing space provided in the vehicle frame or the like. In other words, the vehicle frame may be used instead of the housing case 50.

[0019] <Battery pack> The battery pack 20 has a plurality of battery blocks 21 (sometimes referred to as a battery stack or battery module). The battery pack 20 is formed by connecting these plurality of battery blocks 21 in series and / or in parallel. Each battery block 21 has a plurality of battery cells 22. Each battery cell 22 is made up of a lithium-ion secondary battery, a nickel-metal hydride secondary battery, etc. A lithium-ion secondary battery is a secondary battery that uses lithium as a charge carrier, and may include not only general lithium-ion secondary batteries with a liquid electrolyte, but also so-called all-solid-state batteries that use a solid electrolyte. The battery block 21 is formed by connecting these plurality of battery cells 22 in series and / or in parallel via a busbar 23. Whether or not to provide a battery block 21 is optional, and the battery pack 20 may be formed by connecting a plurality of battery cells 22 in series and / or in parallel. In this embodiment, the battery pack 20, the battery block 21, and the battery cells 22 correspond to the battery section.

[0020] The battery cell 22 is equipped with a cell explosion-proof valve (safety valve) 22a that releases internal gas when the pressure difference between the inside and outside of the battery case exceeds a predetermined value. In the first embodiment, the cell explosion-proof valve 22a is provided at any location; for example, in Figure 3, it is provided on the upper surface of the battery cell 22. <Junction Box> The junction box 60 houses one or more relay switches 61, etc. As shown in Figure 2, the relay switches 61 are used to connect battery blocks 21 (or battery cells 22) in series and / or parallel. The relay switches 61 also allow the battery pack 11 to be charged and discharged by switching the energization and disconnection of the battery pack 20. The on / off state of these relay switches 61 is controlled by the battery control device 40, etc.

[0021] <Battery monitoring device> The battery monitoring device 30 will now be described. Note that the configuration of each battery monitoring device 30 is common to all of them. The battery monitoring device 30 is also called a satellite battery module (SBM) and is provided for each battery block 21, that is, for each of the multiple battery cells 22. As shown in Figure 2, each battery monitoring device 30 is equipped with a monitoring IC 31, a slave-side wireless IC 32, a slave-side wireless antenna 33, etc. These are mounted on the monitoring circuit board 34 of the battery monitoring device 30 and housed and fixed in the SBM case 35 (shown by a dashed line in Figure 2), which serves as the housing for the battery monitoring device 30.

[0022] The slave-side wireless IC 32 is connected to the monitoring IC 31 by a wired connection. The slave-side wireless IC 32 is also connected to the slave-side wireless antenna 33 by a wired connection.

[0023] The monitoring IC 31, also known as the cell monitoring circuit, acquires (senss) battery information from each battery cell 22 constituting the battery block 21 via physical quantity detection sensors (not shown). Examples of physical quantity detection sensors include voltage sensors, temperature sensors, and current sensors. The battery information includes, for example, voltage information, temperature information, and current information from each battery cell 22. The monitoring target of the battery monitoring device 30 may be the battery block 21, the entire battery pack 20, or it may be changed as desired.

[0024] When the monitoring IC 31 receives data requesting the acquisition and transmission of battery information (control data as control information), it acquires the battery information according to the control data and transmits monitoring data (control results) that include at least the battery information. The monitoring IC 31 may also have a function to perform fault diagnosis (self-diagnosis) of the circuit portion of the battery monitoring device 30, including itself, and transmit the diagnostic results along with the acquired battery information in the monitoring data.

[0025] The slave-side wireless IC32 includes an RF circuit (not shown), a microcontroller, and a front-end circuit for wirelessly transmitting and receiving data. The slave-side wireless IC32 has a transmission function that modulates data and oscillates at the frequency of the RF signal. Simultaneously, the slave-side wireless IC32 has a reception function that demodulates the received data. RF is an abbreviation for "radio frequency."

[0026] The slave-side wireless IC 32 modulates the monitoring data, including battery information, received from the monitoring IC 31, and transmits it to the battery control device 40 via the slave-side wireless antenna 33. At the same time, the slave-side wireless IC 32 adds data necessary for wireless communication, such as communication control information, to the monitoring data including battery information before transmitting it. This data includes, for example, an identifier (ID) and an error detection code. Furthermore, the slave-side wireless IC 32 has functions to determine the data size, communication format, and schedule for communication between the battery monitoring device 30 and the battery control device 40, as well as a function to detect errors.

[0027] Furthermore, the slave-side wireless IC 32 receives data wirelessly transmitted from the battery control device 40 via the slave-side wireless antenna 33 and demodulates it. When the slave-side wireless IC 32 receives control data, for example, including a request to acquire and transmit battery information, it transmits (transfers) it to the monitoring IC 31 via a wired connection. Then, when the slave-side wireless IC 32 receives monitoring data, including battery information, from the monitoring IC 31 as a response to the request, it modulates the response data, including the monitoring data, and wirelessly transmits it to the battery control device 40 via the slave-side wireless antenna 33.

[0028] The slave unit's wireless antenna 33 converts RF signals, which are electrical signals, into radio waves and radiates them into space. The slave unit's wireless antenna 33 also receives radio waves propagating through space and converts them into electrical signals.

[0029] <Battery control device> The battery control device 40 is also called a battery ECU or BMU (Battery Management Unit). The battery control device 40 is configured to communicate wirelessly with each battery monitoring device 30.

[0030] More specifically, as shown in Figure 2, the battery control device 40 includes a battery control MCU 41, a master unit wireless IC 42, a master unit wireless antenna 43, and the like. These are mounted on the control circuit board 44 of the battery control device 40 and housed and fixed in the ECU case 45 (shown as a dashed line in Figure 2), which serves as the housing for the battery control device 40.

[0031] The master unit wireless IC 42 is connected to the battery control MCU 41 by a wire. The master unit wireless IC 42 is also connected to the master unit wireless antenna 43 by a wire.

[0032] The battery control MCU41 is composed of a microcontroller (Micro Controller Unit) including a CPU, ROM, RAM, and input / output interfaces. The CPU of the battery control MCU41 loads the program stored in ROM into RAM and executes it. The program stored in ROM contains, for example, code related to battery control.

[0033] As an example of battery control processing, the battery control MCU 41 is configured to acquire the terminal voltage (total voltage) of the battery pack 20 via a voltage sensor (not shown). The total voltage of the battery pack 20 is input from a power line connected to the relay switch 61 and the electrical load (an electrical load outside the battery pack 11) in the junction box 60, for example. The voltage sensor may be located inside the junction box 60, inside the battery control device 40, or elsewhere.

[0034] As an example of the main processing performed by the battery control MCU 41, the battery control MCU 41 sends control data to the battery monitoring device 30 requesting the acquisition and transmission of battery information. The battery control MCU 41 also performs various processes related to the monitoring of the battery pack 20, battery block 21, and battery cells 22 based on the monitoring data, including battery information, received from the battery monitoring device 30. For example, the battery control MCU 41 may send monitoring results (monitoring data) to the vehicle ECU 14, which is a higher-level ECU. In this case, the battery control MCU 41 may calculate the SOC and / or SOH based on the battery information and send battery information, including the calculated SOC and SOH, to the vehicle ECU 14. The battery control MCU 41 also controls relay switches 61, etc., which switch the energization and disconnection states between the battery pack 20 and the PCU 12 and motor 13, based on the monitoring results, etc. The battery control MCU 41 may also send an equalization signal to equalize the voltage of each battery cell 22. In this embodiment, the vehicle ECU 14 issued instructions to the PCU 12 to control the charging and discharging of the battery pack 20, but the battery control MCU 41 may be configured to perform this function. As described above, the battery control MCU 41 monitors and manages the battery pack 20, the battery block 21, and the battery cells 22.

[0035] The master unit wireless IC 42, like the slave unit wireless IC 32, includes an RF circuit (not shown), a microcontroller, a front-end circuit, etc., for wirelessly transmitting and receiving data. The master unit wireless IC 42, like the slave unit wireless IC 32, has both transmitting and receiving functions.

[0036] The master unit wireless IC 42 demodulates the received monitoring data, including battery information, via the master unit wireless antenna 43, and transmits it to the battery control MCU 41. The master unit wireless IC 42 also modulates the control data received from the battery control MCU 41, adding data necessary for wireless communication such as communication control information, and transmits it to the battery monitoring device 30 via the master unit wireless antenna 43. The data necessary for wireless communication includes, for example, an identifier (ID) and an error detection code. The master unit wireless IC 42 also has functions to determine the data size, communication format, and schedule for communication between the battery monitoring device 30 and the battery control device 40, as well as a function to detect errors.

[0037] The master unit's wireless antenna 43 has the same configuration and function as the slave unit's wireless antenna 33. That is, the master unit's wireless antenna 43 converts RF signals, which are electrical signals, into radio waves and radiates them into space, and also receives radio waves propagating in space and converts them into electrical signals.

[0038] <Storage Case> The housing case 50 is made of a conductor such as metal. The housing case 50 is formed in the shape of a metal box and is approximately a rectangular parallelepiped. It may also be made of a non-conductive material such as resin in part or in whole. The housing case 50 houses the battery pack 20, the battery monitoring device 30, and the battery control device 40 in the battery housing space inside.

[0039] Furthermore, as shown in Figure 4, the housing case 50 is equipped with an explosion-proof valve 51 that releases internal gas when the pressure difference between the inside and outside of the housing case 50 exceeds a predetermined value. The explosion-proof valve 51 is constructed, for example, by closing a through-hole 51a that penetrates the housing case 50 with a cover member 51b and welding it, so that when the difference in air pressure between the inside and outside exceeds a predetermined value, the cover member 51b comes off and gas escapes from the through-hole 51a. The explosion-proof valve 51 corresponds to the opening of the housing case 50.

[0040] Furthermore, the cover member 51b may be made of resin to facilitate the operation of the housing explosion-proof valve 51, or a groove may be formed in the cover member 51b to make it prone to cracking when the air pressure increases. Also, the cover member 51b may be thinner than the thickness of the housing case 50. Moreover, it is not always necessary to configure the housing explosion-proof valve 51 by closing the through hole 51a with the cover member 51b; for example, a circular or hexagonal groove (thin-walled section) may be formed in the housing case 50 so that when the air pressure increases, the housing case 50 cracks and the through hole 51a is formed. Also, the housing explosion-proof valve 51 does not need to be formed on its top surface, but may be provided on the side or bottom surface. The number and arrangement of the housing explosion-proof valves 51 are arbitrary. However, it is preferable that they are not provided on surfaces that are obstructed by the vehicle body or the like, making it difficult for gas to escape.

[0041] Here, the arrangement of the battery pack 20, battery monitoring device 30, battery control device 40, and junction box 60 will be briefly explained based on Figure 3. The bottom surface of the housing case 50 is the mounting surface of the vehicle 10. Figure 3 is a schematic plan view showing the inside of the battery pack 11 when viewed from above in the vertical direction. As shown in Figure 3, multiple battery blocks 21 constituting the battery pack 20 are arranged in the longitudinal direction (X direction in Figure 3) inside the housing case 50, which is roughly rectangular in shape. In each battery block 21, the battery cells 22 constituting the battery block 21 are arranged so as to be stacked in the short direction (Y direction in Figure 3) of the housing case 50. Hereafter, the longitudinal direction of the housing case 50 may be referred to as the X direction, the short direction as the Y direction, and the vertical direction as the Z direction.

[0042] The battery monitoring device 30 and busbars 23 are positioned on the top surface of each battery block 21 (the side facing the Z+ direction in Figure 3) and fixed in place with screws or the like. The battery control device 40 and junction box 60 are positioned at the very end in the longitudinal direction (X direction). In this case, the battery control device 40 is placed directly above the junction box 60 (on the Z+ direction side). It is desirable that the battery control device 40 be positioned so that the master unit wireless antenna 43 is located near the top surface of the battery block 21, more preferably above the top surface. Note that the arrangement of the battery pack 20, battery monitoring device 30, battery control device 40, and junction box 60 shown in Figure 3 is just an example and can be changed as desired. Specific examples of changes will be described later.

[0043] By the way, in order to perform wireless communication properly, it is desirable that the antenna characteristics of the slave-side wireless antenna 33 and the master-side wireless antenna 43 be maintained within an appropriate range under any environmental conditions. To explain with a specific example, the battery pack 11 is being considered for reuse with consideration for the environment. Furthermore, when it is reused, it is being considered not only to reuse the battery pack 11 as is, but also to reuse the battery monitoring system 100 and the battery pack 20 that make up the battery pack 11 individually. Also, when it is reused, it is not limited to being reused in the same type of vehicle, but it is also envisioned that it may be reused in a different type of vehicle. And when it is reused in a different type of vehicle, the arrangement of the battery pack 20 and the battery monitoring system 100 may be changed, or the housing case 50 that houses the battery monitoring system 100 may be changed to a different case.

[0044] In such cases, the antenna characteristics of the slave unit's wireless antenna 33 and the master unit's wireless antenna 43 may be affected. Antenna characteristics refer to, for example, VSVR (Voltage Standing Wave Ratio). The effect on antenna characteristics will be explained in detail. In the SBM case 35 and the ECU case 45, at least the parts facing the antennas 33 and 43, more specifically, the parts that can become radio wave paths, are generally made of a radio wave transparent material such as resin so as not to interfere with radio waves. In this embodiment, the SBM case 35 and the ECU case 45 are made of resin. Therefore, capacitance (stray capacitance) is generated between the antennas 33 and 43 and metal parts outside the cases 35 and 45 (for example, the housing case 50 or the battery case of the battery cell 22) via the cases 35 and 45. This capacitance affects the antenna characteristics. For this reason, the shape and size of the antennas 33 and 43 are designed so that the antenna characteristics are appropriate, taking these capacitances into consideration.

[0045] Note that the SBM case 35 and the ECU case 45 may be collectively referred to as cases 35 and 45. Also, the slave-side wireless antenna 33 and the master-side wireless antenna 43 may be collectively referred to as antennas 33 and 43. Furthermore, the monitoring circuit board 34 and the control circuit board 44 may be collectively referred to as circuit boards 34 and 44.

[0046] However, when the battery monitoring device 30 (or battery control device 40) or the configuration of the housing case 50 is changed during reuse, the capacitance between them may fluctuate. If the ratio of the fluctuation to the capacitance before the change is too large, it may affect the antenna characteristics and prevent proper wireless communication. The fluctuation amount is the difference between the capacitance before the change and the capacitance after the change, and the ratio of the fluctuation amount is the value calculated by dividing the fluctuation amount by the capacitance before the change. Hereafter, the ratio of the fluctuation amount will be referred to as the fluctuation ratio.

[0047] Therefore, in the first embodiment, the battery monitoring device 30 and the battery control device 40 are designed to prevent large fluctuations in the rate of change, regardless of how the surrounding environment changes, such as when the battery is reused. This will be explained in detail below with reference to Figure 5. Figure 5 is a schematic side cross-sectional view showing the inside of the SBM case 35 in the battery monitoring device 30.

[0048] As shown in Figure 5, the battery monitoring device 30 has a monitoring circuit board 34 that is roughly rectangular in shape, with the slave unit wireless antenna 33 mounted on its upper surface. This is then housed and fixed in a resin SBM case 35. The SBM case 35 is formed as a flat rectangular parallelepiped. The slave unit wireless IC 32 is installed on the lower surface of the monitoring circuit board 34 (the surface opposite to the mounting surface of the slave unit wireless antenna 33).

[0049] The slave-side wireless antenna 33 is a pattern antenna, and for example, as shown in Figure 6, it comprises an element 33a for radiating radio waves, a ground plate 33b as a wiring pattern positioned opposite the element 33a, and a dielectric 33c interposed between the element 33a and the ground plate 33b. The element 33a is a thin metal conductor and has a shape that combines an L-shaped part and a rectangular part. The rectangular part corresponds to a stub shape (a part where the wiring branches off). Because it has an open end, the rectangular part is also called an open stub shape. A signal is input to the element 33a from a feed point (not shown).

[0050] The ground plate 33b is a thin, elongated metal conductor and is at a potential corresponding to (e.g., equivalent to) the reference potential (e.g., ground) of the monitoring circuit board 34. The element 33a is placed on the ground plate 33b via a dielectric 33c. The pattern of the element 33a (shape and size, mainly the length and width dimensions of the rectangular portion) is adjusted so that the impedance between the element 33a and the ground plate 33b (the impedance of the slave-side wireless antenna 33) is the desired impedance. The ground plate 33b is positioned on the lower side (the side of the monitoring circuit board 34), and the element 33a is positioned on the upper side.

[0051] As shown in Figure 5, a metal plate 37 is arranged on the lower side of the monitoring circuit board 34 via an insulating sheet 36 as a proximity conductor. A proximity conductor is a conductor that is close enough to affect the antenna characteristics of the slave-side wireless antenna 33. The effect on antenna characteristics refers to a change in the impedance of the slave-side wireless antenna 33. More specifically, it is a conductor that is not electrically in contact (connected) to the element 33a of the slave-side wireless antenna 33, and is located at a distance of less than or equal to the wavelength of the lowest frequency in the frequency band used in wireless communication. The metal plate 37, which is the proximity conductor in this embodiment, will be described in detail below.

[0052] The metal plate 37 is positioned on the monitoring circuit board 34 on the side opposite to the side on which the slave-side wireless antenna 33 is installed. The metal plate 37 is flat, and its plane is parallel to that of the monitoring circuit board 34. Specifically, the metal plate 37 is laminated to the monitoring circuit board 34 via an insulating sheet 36. Furthermore, the metal plate 37 is positioned closest to the slave-side wireless antenna 33 compared to other conductors (excluding circuit elements, etc.) mounted on the monitoring circuit board 34. Specifically, in a predetermined direction (perpendicular to the monitoring circuit board 34), the metal plate 37 is closest to the slave-side wireless antenna 33 compared to other conductors present inside the SBM case 35. Other conductors present inside the SBM case 35 include, for example, circuit elements (excluding circuit elements mounted on the monitoring circuit board 34), wiring, metal components, etc. Other conductors also include those located outside the SBM case 35 (such as the housing case 50, the busbar 23, and the battery case of the battery cell 22). Furthermore, although the metal plate 37 is described as flat, "flat" refers to a shape that is sufficiently thin compared to other dimensions, and may have no irregularities, or it may have some irregularities.

[0053] Furthermore, as shown in Figure 7, the metal plate 37 overlaps with at least a portion of the projection surface of the slave-side wireless antenna 33 when a predetermined direction is used as the projection direction. The predetermined direction is the direction in which the projection surface of the slave-side wireless antenna 33 in the predetermined direction is the largest surface area compared to the projection surface in other directions. In this embodiment, the predetermined direction is the vertical direction of the monitoring circuit board 34. In addition, the projection surface of the slave-side wireless antenna 33 includes at least the projection surface of element 33a and the projection surface of ground plate 33b. In this embodiment, the area of ​​the metal plate 37 is defined such that the entire projection surface of the slave-side wireless antenna 33 overlaps with the metal plate 37 in the vertical direction. In other words, the area of ​​the metal plate 37 is defined such that when the slave-side wireless antenna 33 is projected from the vertical direction, its entire projection surface is included in the metal plate 37. In this embodiment, the metal plate 37 is configured to cover all of the slave-side wireless IC 32 located on the lower surface of the monitoring circuit board 34.

[0054] As shown in Figure 5, the monitoring circuit board 34 and the metal plate 37 are housed and fixed inside the SBM case 35 in a stacked state. The size and shape of the SBM case 35 and the fixing position of the monitoring circuit board 34 are determined such that the distance L11 from the top surface of the monitoring circuit board 34 to the top surface of the SBM case 35 is greater than the distance L12 from the slave-side wireless antenna 33 to the metal plate 37 in the vertical direction of the monitoring circuit board 34. Similarly, the size and shape of the SBM case 35 and the fixing position of the monitoring circuit board 34 are determined such that the distance L13 from the bottom surface of the metal plate 37 to the bottom surface of the SBM case 35 is greater than the distance L12 from the slave-side wireless antenna 33 to the metal plate 37 in the vertical direction of the monitoring circuit board 34. Therefore, even if the external conditions of the battery monitoring device 30 (such as its arrangement and the configuration of the housing case 50) are changed, the metal plate 37 will remain the conductor positioned closest to the slave-side wireless antenna 33, as long as the internal configuration of the battery monitoring device 30 is not changed.

[0055] The battery monitoring device 30 has been described above, and the battery control device 40 has a nearly identical configuration. Here, using Figure 5, the internal configuration of the battery control device 40 will be briefly explained. In the battery control device 40, the control circuit board 44 has the master unit wireless antenna 43 installed on its upper surface, and is housed and fixed in a resin ECU case 45 with the antenna installed. The master unit wireless IC 42 is installed on the lower surface of the control circuit board 44 (the surface opposite to the mounting surface of the master unit wireless antenna 43).

[0056] The master unit wireless antenna 43 has the same configuration as the slave unit wireless antenna 33. That is, the master unit wireless antenna 43 comprises an element 43a for radiating radio waves, a ground plate 43b positioned opposite the element 43a in an insulated state, and a dielectric 43c interposed between the element 43a and the ground plate 43b. Since the element 43a, the ground plate 43b, and the dielectric 43c are configured in the same way as the slave unit wireless antenna 33, their descriptions will be omitted by reusing the description of the slave unit wireless antenna 33.

[0057] A metal plate 47 is positioned on the underside of the control circuit board 44 via an insulating sheet 46, acting as a proximity conductor. The shape, size, and arrangement of this metal plate 47 are the same as those of the metal plate 37 in the battery monitoring device 30. Specifically, the area of ​​the metal plate 47 is defined such that, in the vertical direction of the control circuit board 44, the entire projection surface of the master unit wireless antenna 43 overlaps with the metal plate 47. Furthermore, the metal plate 47 completely covers the master unit wireless IC 42 located on the underside of the control circuit board 44. For this reason, a detailed explanation of the metal plate 47 will be omitted, using the explanation of the metal plate 37 in the battery monitoring device 30.

[0058] The control circuit board 44 and the metal plate 47 are then housed and fixed inside the ECU case 45 in a stacked state. The ECU case 45 has a configuration almost identical to that of the SBM case 35, so its description is omitted.

[0059] Next, the operation of the battery monitoring system 100 configured in this way when it is reused will be explained with reference to Figures 8 and 9. Here, the explanation will focus on the battery monitoring device 30, but the battery control device 40 is almost the same.

[0060] First, with reference to Figure 8, the change in capacitance in a comparative example where the metal plate 37 is absent will be explained. As mentioned above, the battery monitoring device 30 is housed inside the housing case 50, which is a metal conductor. Therefore, as shown in Figure 8(a), capacitance (shown by a dashed line in Figure 8) is generated between the slave unit-side wireless antenna 33 and the conductors located outside the SBM case 35, with the resin SBM case 35 in between. The external conductors differ depending on the arrangement of the battery monitoring device 30, and in the case of Figure 8(a), for the sake of simplicity, they are the top and bottom surfaces of the housing case 50. In the case of Figure 8(a), the total capacitance generated between these is, for example, 8 pF (picofarads).

[0061] Let's assume that this battery monitoring device 30 is reused and housed in a housing case 150 with a different configuration than the housing case 50. For the sake of simplicity, we will explain this by assuming that only the distance between the wireless antenna 33 on the slave unit side of the battery monitoring device 30 and the top surface of the housing case 150 increases (moves further apart), as shown in Figure 8(b), while all other conditions remain the same.

[0062] The capacitance between the wireless antenna 33 on the slave unit and the top surface of the housing case 150 decreases as the distance between them increases. Let's assume the total capacitance after the change is, for example, 6pF. In other words, the amount of change is 2pF, and the rate of change is 25% (=2÷8×100).

[0063] Next, with reference to Figure 9, the change in capacitance in the first embodiment in which the metal plate 37 is present will be described. As mentioned above, the battery monitoring device 30 is housed inside the housing case 50, which is a metal conductor. Therefore, in the state before modification, as shown in Figure 9(a), capacitance (shown by a dashed line in Figure 9) is generated between the slave-side wireless antenna 33 and the conductor located outside the SBM case 35, with the resin SBM case 35 in between. The external conductor differs depending on the arrangement of the battery monitoring device 30, and in the case of Figure 9(a), for the sake of simplicity in the explanation, it is the top surface of the housing case 50. Note that, as shown in Figure 9(a), since the metal plate 37, which is a nearby conductor, is located on the bottom surface of the monitoring circuit board 34, unlike in Figure 8(a), almost no capacitance is generated between the slave-side wireless antenna 33 and the bottom surface of the housing case 50.

[0064] On the other hand, a large capacitance is generated between the wireless antenna 33 on the slave unit side and the metal plate 37. This is because, as mentioned above, the distance between the wireless antenna 33 on the slave unit side and the metal plate 37 is the closest and has the largest overlapping area compared to other conductors (for example, the bottom surface of the housing case 50). Therefore, the total capacitance generated in the case of Figure 9(a) is much larger than in the case of Figure 9(a), for example, 15 pF (picofarads).

[0065] Suppose this battery monitoring device 30 is reused and housed in the housing case 150, as in Figure 8(b). In this case, as described above, only the distance between the slave unit's wireless antenna 33 and the top surface of the housing case 150 increases, so the capacitance between them decreases. In this case, as in Figure 8(b), the amount of change (decrease) is 2pF. Therefore, the total capacitance after the change is 13pF, and the rate of change is approximately 13% (=2÷15×100).

[0066] Thus, when the battery monitoring device 30 of the first embodiment is reused, the rate of fluctuation can be reduced compared to the case where the metal plate 37 is absent. Therefore, the impact on antenna characteristics can be reduced.

[0067] According to the above embodiment, the following effects are achieved.

[0068] The battery monitoring device 30 and the battery control device 40 are each equipped with metal plates 37 and 47, which are adjacent conductors that overlap with at least a portion of the projection plane of the antennas 33 and 43 when a predetermined direction is set as the projection direction. Electrostatic coupling occurs between these metal plates 37 and 47 and the antennas 33 and 43, generating capacitance. If this capacitance is large, even if stray capacitance occurs between other conductors, the proportion of capacitance between the antennas 33 and 43 becomes large (dominant), and even if the capacitance between other conductors fluctuates, the rate of fluctuation can be reduced. In other words, large changes in capacitance can be suppressed, and the impact on antenna characteristics can be reduced.

[0069] Furthermore, the metal plates 37 and 47 are positioned closest to the antennas 33 and 43 compared to other conductors (excluding circuit elements mounted on circuit boards 34 and 44). This increases the capacitance between the metal plates 37 and 47 and the antennas 33 and 43, allowing the capacitance ratio to be increased even after fluctuations. As a result, the fluctuation ratio can be reduced.

[0070] Furthermore, the projection planes of antennas 33 and 43 are the planes with the largest projection planes compared to those in other directions. As a result, the capacitance between the metal plates 37 and 47 and antennas 33 and 43 is increased, allowing the ratio to be increased even after fluctuations. Consequently, it becomes possible to reduce the rate of fluctuation.

[0071] The predetermined direction (projection direction) is perpendicular to the monitoring circuit board 34 (or the control circuit board 44 in the case of the battery control device 40). When metal plates 37 and 47 are fixed to the circuit boards 34 and 44, the distance and overlapping area between the antennas 33 and 43 and the metal plates 37 and 47 can be stabilized, making it less likely for the capacitance to fluctuate.

[0072] Furthermore, the metal plates 37 and 47 are flat, and their planes are arranged parallel to the circuit boards 34 and 44. This increases the capacitance between the metal plates 37 and 47 and the antennas 33 and 43. In addition, even if the configuration of the battery pack 11 on the side where the metal plates 37 and 47 are located is changed, for example, in the battery monitoring device 30, the configuration and arrangement of the battery pack 20 located on the side of the metal plate 37 can be changed, the distance and overlapping area between the antennas 33 and 43 and the metal plates 37 and 47 can be stabilized, making it less likely for the capacitance to fluctuate.

[0073] Furthermore, in the circuit boards 34 and 44, the metal plates 37 and 47 are positioned on the lower surface opposite to the upper surface where the elements 33a and 43a are located. This prevents the metal plates 37 and 47 from interfering with the radio waves emitted from the elements 33a and 43a.

[0074] Furthermore, on circuit boards 34 and 44, the slave-side wireless IC 32 and the master-side wireless IC 42 are located on the lower surface opposite to the upper surface where elements 33a and 43a are positioned, and the metal plates 37 and 47 are configured to cover the slave-side wireless IC 32 and the master-side wireless IC 42. The metal plates 37 and 47 can block external noise, thereby suppressing any impact on the slave-side wireless IC 32 and the master-side wireless IC 42. In addition, since the slave-side wireless IC 32 and the master-side wireless IC 42 are located on different surfaces from elements 33a and 43a, it is possible to prevent them from adversely affecting each other.

[0075] Furthermore, in a predetermined direction (vertical direction), the entire projection surface of antennas 33 and 43 overlaps with metal plates 37 and 47. This maximizes the overlapping area, making it possible to maximize the capacitance ratio between metal plates 37 and 47 and antennas 33 and 43, thereby reducing the fluctuation rate.

[0076] Elements 33a and 43a have an L-shape and a stub shape, respectively. This allows for adjustment of the capacitance between elements 33a and 43a and the ground plates 33b and 43b, the impedance of antennas 33 and 43, and the capacitance between elements 33a and 43a and the metal plates 37 and 47, thereby improving the antenna characteristics.

[0077] Insulating sheets 36 and 46 are provided between the antennas 33 and 43 (more specifically, the circuit boards 34 and 44) ​​and the metal plates 37 and 47. This prevents leakage current from the antennas 33 and 43, even if a change in arrangement causes high-voltage sources such as the battery cells 22 to be placed below the battery monitoring device 30 or the battery control device 40.

[0078] (Modified version of the first embodiment) The following describes a modified version in which some of the components of the battery pack 11 have been changed.

[0079] In the first embodiment described above, the SBM case 35 and the ECU case 45 are made of resin, but a part of them may be made of a conductor (such as metal). In that case, for example, as shown in Figure 10, the lower surface of the SBM case 35 may be made of metal and function as a metal plate 37. This reduces the number of parts. The ECU case 45 may be constructed in the same manner.

[0080] In the first embodiment described above, if part or all of the SBM case 35 and ECU case 45 are made of a conductor (such as metal), it is necessary to provide a passage that allows radio waves from the antennas 33 and 43 to pass through.

[0081] For example, if the SBM case 35 is made of metal, as shown in Figure 11, a pass-through opening 35a may be provided on the side of the SBM case 35 at a position facing the slave-side wireless antenna 33 (near the center in the Y direction in Figure 11). The pass-through opening 35a is located on the side of the radio wave propagation path that is closer to the communication partner (battery control device 40) than the slave-side wireless antenna 33. Also, the pass-through opening 35a is located on the opposite side of the metal plate 37 from the slave-side wireless antenna 33 in the radio wave propagation path. Specifically, the pass-through opening 35a is provided on the side of the SBM case 35, above the monitoring circuit board 34 (Z+ side), and extends to the top surface. The pass-through opening 35a may also be provided from the side to the top surface of the SBM case 35, and it is even better if the surface of the top surface of the SBM case 35 facing the slave-side wireless antenna 33 is also a pass-through opening 35a.

[0082] In Figure 11, the passage opening 35a is covered with a resin cover, but it can be configured in any way as long as it allows radio waves to pass through, or it may be left open without any cover. This allows for proper input and output of radio waves even when a metal plate 37 is provided.

[0083] Furthermore, it is preferable that the passage opening 35a is located opposite the slave unit's wireless antenna 33, and is also desirable that it be located on the opposite side from the metal plate 37. In other words, if the metal plate 37 is located on the lower side (Z- side) of the monitoring circuit board 34, it is desirable that it be located above the upper side (Z+ side) where the slave unit's wireless antenna 33 is located. This ensures that radio waves can be properly input and output even when the metal plate 37 is provided.

[0084] Furthermore, the width dimension of the passage opening 35a is set to be at least half the wavelength of the radio waves radiated from the slave-side wireless antenna 33. The width dimension can be in any direction, and can be either vertical or horizontal. For example, in the modified example shown in Figure 11, the width dimension L15 of the passage opening 35a is set to be at least half the wavelength of the radio waves radiated from the slave-side wireless antenna 33 in the Y direction, which is perpendicular to the Z direction (the vertical direction of the monitoring circuit board 34, which is the projection direction). This ensures that the propagation path of radio waves passing through the passage opening 35a is properly secured in the Y direction.

[0085] In the first embodiment described above, it is desirable that no conductors are placed on the side of the metal plate 37 opposite to the slave unit wireless antenna 33 (i.e., the side above the monitoring circuit board 34) in the projection direction (the Z direction, which is the direction perpendicular to the monitoring circuit board 34). However, if any conductors are placed there, it is desirable that the distance between the conductor and the slave unit wireless antenna 33 be at least half the wavelength of the radio waves radiated from the slave unit wireless antenna 33. The ECU case 45 may be configured similarly.

[0086] For example, as in the first embodiment, when the upper surface (conductor) of the housing case 50 is positioned in the Z direction, the distance between the upper surface of the housing case 50 and the slave unit wireless antenna 33 is set to be at least half the wavelength of the radio waves radiated from the slave unit wireless antenna 33. This ensures that the radio wave propagation path is properly secured in the Z direction.

[0087] Furthermore, as shown in the modified example in Figure 11, when the upper surface (conductor) of the SBM case 35 is positioned in the Z direction, the distance L16 between the upper surface of the SBM case 35 and the slave-side wireless antenna 33 is set to be at least half the wavelength of the radio waves radiated from the slave-side wireless antenna 33. This ensures that the propagation path of radio waves passing through the through-hole 35a is properly secured in the Z direction.

[0088] In the first embodiment described above, it is desirable that the distance between the top surface of the SBM case 35 and the slave-side wireless antenna 33 be at least half the wavelength of the radio waves radiated from the slave-side wireless antenna 33. This ensures that even if the external configuration of the SBM case 35 is changed, for example, if a conductor is placed outside the SBM case 35, the SBM case 35 can ensure that the size of the propagation path in the Z direction (vertical direction) is at least half the wavelength of the radio waves. Thus, the propagation path of radio waves in the Z direction can be properly secured. The ECU case 45 may be configured similarly.

[0089] In the first embodiment described above, the shapes of elements 33a and 43a may be arbitrarily changed to obtain desired antenna characteristics. For example, the vertical and horizontal dimensions of the stub shape (rectangular portion) may be changed, or the stub shape may be omitted. Also, it may not be L-shaped. Furthermore, as shown in Figure 12, a comb-like shape 133 may be provided on elements 33a and 43a. This makes it possible to adjust the impedance and capacitance to arbitrary values.

[0090] In the first embodiment described above, the shapes of the ground plates 33b and 43b may be arbitrarily changed. For example, as shown in Figure 13(a), a comb-tooth shape 111 may be formed on the ground plates 33b and 43b, or a meander shape 112 may be formed as shown in Figure 13(b). Incidentally, the ground plates 33b and 43b do not need to face all regions of the elements 33a and 43a, and as shown in Figure 14, they do not need to overlap with parts of the elements 33a and 43a. This allows for appropriate adjustment of impedance, etc. In Figure 14, the dielectrics 33c and 43c are omitted for illustrative purposes.

[0091] Regardless of the shape of elements 33a, 43a and ground plates 33b, 43b, the projection plane of antennas 33, 43 will include at least the projection planes of elements 33a, 43a and the projection planes of ground plates 33b, 43b.

[0092] In the first embodiment described above, the metal plates 37 and 47 were configured to cover the lower surfaces of the circuit boards 34 and 44. However, if a portion of the projection surface of the antennas 33 and 43 overlaps with the metal plates 37 and 47, their size and other characteristics may be arbitrarily changed. For example, as shown in Figure 15(a), about half of the projection surface of the antennas 33 and 43 may overlap with the metal plates 37 and 47. Alternatively, as shown in Figure 15(b), the projection surface of the antennas 33 and 43 and the area of ​​the metal plates 37 and 47 may be the same, but only a portion may overlap. Although not shown, metal plates 37 and 47 that perfectly match the projection surface of the antennas 33 and 43 may also be provided. It is desirable to set the size of the metal plates 37 and 47 so that more than half of the projection surface of the antennas 33 and 43 overlaps with the metal plates 37 and 47.

[0093] (Second Embodiment) The battery pack of the second embodiment will be described below.

[0094] As in the first embodiment, in a battery monitoring system 100 that uses wireless communication, communication is affected by electromagnetic noise. Therefore, an electromagnetic wave shielding member (a metal conductor in the first embodiment) that absorbs or reflects external electromagnetic noise is used in the housing case 50 (the housing of the battery pack 11) in which the battery monitoring system 100 is housed. For example, a document describing the use of an electromagnetic wave absorbing member in the housing case is the patent document shown in Japanese Patent Publication No. 2020-510956.

[0095] However, the source of electromagnetic noise (noise source) is not necessarily located outside the housing case 50, but may also be located inside the housing case 50. For example, in the first embodiment, the main noise sources located inside the housing case 50 of the battery pack 11 include a junction box 60 which has a relay switch 61 and switches the connection of the current. Therefore, when using wireless communication inside the housing case 50, it is necessary to suppress the influence of electromagnetic noise from noise sources inside the housing case 50.

[0096] The second embodiment was made in view of the above circumstances, and its main purpose is to suppress the effects of noise generated inside the housing case 50. This will be explained in detail below.

[0097] As described in the first embodiment, the battery control device 40 is located near the junction box 60 (directly above it in the first embodiment) in order to obtain the total voltage (terminal voltage) of the battery pack 20 from the junction box 60. The relay switch 61 of the junction box 60 is connected to an external electrical load (such as an inverter) and is a place where noise is easily introduced through the wiring. In addition, the relay switch 61 can also generate electromagnetic noise when switching. For this reason, the junction box 60 can be said to be a noise source inside the housing case 50 (battery housing space).

[0098] Therefore, in the second embodiment, as shown in Figures 16 to 17, an electromagnetic shield 201 is provided between the battery control device 40 and the junction box 60, which is a noise source, thereby blocking electromagnetic noise from reaching the battery control device 40. In addition, a battery cell 22 is provided between the battery monitoring device 30 and the junction box 60, which is a noise source, thereby blocking electromagnetic noise from reaching the battery monitoring device 30.

[0099] Let me explain in detail. First, I will describe the arrangement of the battery monitoring device 30, the battery control device 40, and the junction box 60 in the second embodiment. Figure 16 is a top view of the interior of the housing case 50 in the second embodiment (viewed from the Z+ direction), and Figure 17 is a side view of the interior of the housing case 50 in the second embodiment (viewed from the Y direction).

[0100] As shown in Figure 16, multiple battery blocks 21 are arranged in a row along the longitudinal direction (X direction) of the housing case 50. The battery control device 40 and junction box 60 are positioned between one side wall 50a of the housing case 50 in the X direction and the side surface of the battery pack 20 (more specifically, the battery blocks 21 located at one end in the X direction). The battery control device 40 is positioned directly above the junction box 60. Also, as shown in Figure 17, the battery control device 40 and junction box 60 are positioned below the upper surface of the battery blocks 21.

[0101] In this embodiment, since the junction box 60 is located directly below the battery control device 40, an electromagnetic shield 201 is provided on the underside of the battery control device 40. This electromagnetic shield 201 is made of a conductive material. In this embodiment, the electromagnetic shield 201 is made of a thin metal plate.

[0102] The electromagnetic shield 201 is sized to at least cover components of the battery control device 40 that are susceptible to electromagnetic noise, such as the battery control MCU 41, the master unit wireless IC 42, and the master unit wireless antenna 43. It is desirable that the shield be large enough to completely cover the bottom surface of the control circuit board 44, specifically the bottom surface of the ECU case 45, and in the second embodiment, it is configured to almost completely cover the top surface of the junction box 60.

[0103] In the battery control device 40, the master unit wireless antenna 43 is mounted on the upper surface of the control circuit board 44 and is configured to radiate radio waves upward. Figures 16 and 17 show an example of radio waves radiated from the master unit wireless antenna 43 with a dashed line. This prevents the radio waves from being blocked by the electromagnetic shield 201. In the frequency band used for wireless communication, the radio waves radiated from the battery control device 40 that are input to the battery monitoring device 30, which is the communication partner, are configured to have a radio wave strength that is stronger than the radio wave strength of the electromagnetic noise generated from the junction box 60.

[0104] On the other hand, as shown in Figure 16, the multiple battery monitoring devices 30 are positioned between one side wall 50b of the housing case 50 in the short direction (Y direction) and the side of the battery pack 20 (more specifically, one side of each battery block 21 in the Y direction). Also, as shown in Figure 17, the battery monitoring devices 30 are positioned below the top surface of the battery block 21. Due to space constraints, the battery monitoring devices 30 are positioned vertically (the vertical direction of the monitoring circuit board 34 is the Y direction), but the orientation can be changed as needed. The slave unit wireless antenna 33 is installed on the side opposite to the battery block 21 in the Y direction (the side of the side wall 50b of the housing case 50). Also, as shown in Figure 17, the slave unit wireless antenna 33 is installed above the junction box 60 in the Z direction.

[0105] Thus, a battery block 21 is positioned between the junction box 60 and the battery monitoring device 30, and the battery case of the battery block 21 (or the battery case of the battery cell 22) is made of a metal conductor that blocks electromagnetic noise. For this reason, the battery case functions as an electromagnetic shielding member interposed between the junction box 60 and the battery monitoring device 30. In the frequency band used for wireless communication, the radio waves radiated from the battery monitoring device 30 that are input to the battery control device 40, which is the communication partner, are set to have a radio wave intensity that is stronger than the radio wave intensity of the electromagnetic noise generated from the junction box 60.

[0106] The wireless antenna 33 on the slave unit side is positioned above the monitoring circuit board 34 in the Z direction and is configured to radiate radio waves (shown by the dashed line) upward. As a result, the radio waves radiated upward from the battery monitoring device 30 are reflected off the top surface (ceiling) of the housing case 50 and input to the battery control device 40. The radio wave paths shown by the dashed lines in Figures 16 and 17 are just examples; it is also possible that the radio waves radiated from the battery monitoring device 30 are reflected off the side wall 50b of the housing case 50, then repeatedly reflected off the top surface of the housing case 50 and the battery case before being input to the battery control device 40. Similarly, radio waves radiated upward from the battery control device 40 are reflected off the top surface of the housing case 50 and input to the battery monitoring device 30. This radio wave path is also just an example; it is also possible that the radio waves radiated from the battery control device 40 are repeatedly reflected off the top surface of the housing case 50 and the battery case, then reflected off the side wall 50b of the housing case 50 and input to the battery monitoring device 30.

[0107] Furthermore, electromagnetic noise radiated from the side of the junction box 60 may be reflected off the side walls 50a and 50b of the housing case 50, wrap around the side of the battery block 21, and reach the battery monitoring device 30 or the battery control device 40. To suppress the effects of such electromagnetic noise, the sides of the junction box 60, the sides of the battery monitoring device 30, or the sides of the battery control device 40 can be covered with electromagnetic shielding.

[0108] According to the above embodiment, the following effects are achieved.

[0109] An electromagnetic shield 201 was interposed between the battery control device 40 and the junction box 60. This suppresses the influence of electromagnetic noise from the junction box 60 on the battery control device 40. Similarly, a battery cell 22 (or its battery case), which functions as an electromagnetic shielding member, was interposed between the battery monitoring device 30 and the junction box 60. This suppresses the influence of electromagnetic noise from the junction box 60 on the battery monitoring device 30.

[0110] In the battery storage space of the housing case 50, the slave-side wireless antenna 33 of the battery monitoring device 30 and the master-side wireless antenna 43 of the battery control device 40 are positioned above the junction box 60, and communication is performed by reflecting radio waves off the top surface of the housing case 50. This prevents radio waves from being blocked by the junction box 60, enabling proper wireless communication.

[0111] The wireless antenna 33 on the slave unit side and the wireless antenna 43 on the master unit side are positioned above the electromagnetic shield 201, and the junction box 60 is separated by the electromagnetic shield 201. Therefore, even without providing an electromagnetic shield on the side, it is possible to make it difficult for noise generated from the junction box 60 to reach the antennas 33 and 43.

[0112] The radio wave intensity emitted from the battery monitoring device 30 and the battery control device 40 is stronger than the radio wave intensity of the electromagnetic noise generated from the junction box 60. Therefore, the effects of electromagnetic noise can be suppressed.

[0113] (Modified version of the second embodiment) The following describes a modified example in which some of the configurations of the battery pack 11 in the second embodiment have been changed.

[0114] In the second embodiment described above, the SBM case 35 and the ECU case 45 are made of resin, but a part of them may be made of an electromagnetic wave shielding material (such as metal). In that case, it is desirable that the surface of the SBM case 35 or the ECU case 45 that is located on the side facing the junction box 60 be made of an electromagnetic wave shielding material. For example, as shown in Figure 17, if the junction box 60 is located directly below the battery control device 40, the bottom surface of the ECU case 45 may be made of a metal conductor and this bottom surface may function as an electromagnetic wave shield (electromagnetic wave shielding material). In this case, the electromagnetic wave shield 201 can be omitted, and the number of parts can be reduced. Similarly, the left side of the SBM case 35 (the side facing the junction box 60) may be made of an electromagnetic wave shielding material.

[0115] In the second embodiment described above, if part or all of the SBM case 35 and ECU case 45 are made of a conductor (such as metal), it is necessary to provide a passage that allows radio waves from the antennas 33 and 43 to pass through.

[0116] For example, as shown in Figures 16 and 17, in the case of a battery control device 40 where the radio wave propagation path is located upward (Z+ direction) and the electromagnetic wave shield 201 is located directly below it, a passage opening 245a may be provided on the upper surface of the ECU case 45 at a position opposite the master unit wireless antenna 43 (near the right side in Figure 18), as shown in Figure 18.

[0117] In Figure 18, the passage opening 245a is covered by a resin cover, but it can be configured in any way as long as it allows radio waves to pass through, or it may be left open without any covering. The passage opening 245a is positioned on the communication partner side of the radio wave propagation path, while being positioned not on the junction box 60 side. In other words, in the example in Figure 18, the passage opening 245a of the ECU case 45 is located on the top surface (the side opposite to the junction box 60 side).

[0118] In this case, the lower surface of the ECU case 45 may be made of a conductor such as metal and function as an electromagnetic wave shielding member (electromagnetic wave shield). This eliminates the need to provide an electromagnetic wave shielding member (such as an electromagnetic wave shield 201) outside the battery control device 40, thereby reducing the number of parts.

[0119] Furthermore, as shown in Figures 16 and 17, in the case of a battery monitoring device 30 in which the radio wave propagation path is located upward (Z+ direction) and the battery cell 22 (battery block 21) is located on the side in the Y direction, a passage opening may similarly be provided on the upper surface (Z+ direction surface) of the SBM case 35 at a position (near the center in the X direction) facing the slave unit wireless antenna 33. If a propagation path is assumed in which radio waves are input and output from the side wall 50b of the battery monitoring device 30 after being reflected off the side wall 50b of the housing case 50, a passage opening may be provided on the side of the SBM case 35 (side of the side wall 50b) at a position facing the slave unit wireless antenna 33. Moreover, it is desirable that the passage opening provided in the SBM case 35 opens in a direction different from the side of the battery cell 22 which functions as an electromagnetic wave shielding member.

[0120] • In the second embodiment described above, directional antennas that emit directional radio waves may be used as antennas 33 and 43. A directional antenna is an antenna that has a strong radio wave intensity in a predetermined direction. When a directional antenna is used, it is desirable that the direction of the antenna is determined so that the direction in which the radio waves emitted from the directional antenna are strong is directed toward the communication partner, but not toward a noise source or an electromagnetic wave shielding member.

[0121] For example, as shown in Figures 16 and 17, in the case of a battery control device 40 in which a junction box 60 and an electromagnetic shield 201 are located directly below and the radio wave propagation path is located above, it is desirable that the direction of the directional antenna be determined such that the direction in which the radio waves radiated from the directional antenna are strongest is upward (towards the battery monitoring device 30 in the propagation path) and not downward (towards the junction box 60, etc.).

[0122] Similarly, as shown in Figures 16 and 17, in the case of a battery monitoring device 30 in which a battery cell 22 (battery block 21) is located on one side in the Y direction and the side wall 50b of the housing case 50 is located on the other side, and the radio wave propagation path is located on the upper side, the direction of the directional antenna is determined such that the direction in which the radio waves radiated from the directional antenna are strongest is upward (towards the battery control device 40 in the propagation path) and not to the side (towards the battery cell 22 or the side wall 50b). However, if a propagation path is assumed in which radio waves are input and output from the side wall 50b of the battery monitoring device 30 after being reflected by the side wall 50b of the housing case 50, the direction of the directional antenna may be determined so that the direction in which the radio waves radiated from the directional antenna are strongest is towards the side of the SBM case 35 (the side of the side wall 50b).

[0123] This prevents electromagnetic shielding materials and noise sources from blocking radio waves from the directional antenna, allowing for proper wireless communication.

[0124] In the second embodiment and its modified form described above, the arrangement of the battery block 21 (including the battery cell 22), the battery monitoring device 30, the battery control device 40, and the junction box 60 may be changed as desired. Examples of changes to the arrangement will be described below with reference to Figures 19 to 23.

[0125] In the modified example shown in Figure 19, the battery control device 40 and the junction box 60 are positioned between one side wall 50a of the housing case 50 in the X direction and the side of the battery pack 20. The battery control device 40 is positioned side-by-side with the junction box 60 in the Y direction. Note that in Figure 19, the junction box 60 is on the left side and the battery control device 40 is on the right side in the Y direction. In the modified example of Figure 19, an electromagnetic shield 201 is positioned between the junction box 60 and the battery control device 40. That is, the electromagnetic shield 201 is provided so as to almost completely cover the side of the junction box 60 on the side of the battery control device 40 in the Y direction (the right side in Figure 19).

[0126] In the modified example shown in Figure 19, if a pass-through opening 245a for radio waves is provided in the ECU case 45, similar to the modified example described above, it should be positioned so that it opens towards the communication partner, but not towards the junction box 60 or the electromagnetic shield 201, which are noise sources. For example, the pass-through opening 245a can be provided on the top surface of the ECU case 45 or on the side of the battery monitoring device 30 in the Y direction (the right side in Figure 19) at a position corresponding to the master unit wireless antenna 43. Furthermore, if a directional antenna is used in the battery control device 40, the direction of the directional antenna should be set so that the direction of strong radio wave intensity is directed towards the communication partner, but not towards the junction box 60 or the electromagnetic shield 201. For example, in the example in Figure 19, the direction in which the radio wave intensity is strongest should be directed upwards or to the right in Figure 19.

[0127] Similarly, if an opening for radio waves to pass through is provided in the SBM case 35, the opening should be provided on the top surface of the SBM case 35, or on the side facing the battery control device 40 in the X direction, or on the side facing the side wall 50b of the housing case 50 in the Y direction, at a position corresponding to the slave unit wireless antenna 33. Also, if a directional antenna is used for the battery monitoring device 30, in the example of Figure 19, the direction in which the radio wave intensity becomes stronger should be upward, or the propagation path should point towards the battery monitoring device 30.

[0128] In the modified example shown in Figure 20(a), the battery blocks 21 (or battery cells 22) are arranged in two rows in the X direction, with a gap in the center in the short direction (Y direction) of the housing case 50. Hereafter, the gap in the center in the Y direction will be referred to as the central passage 210. Also, at one end of the housing case 50 in the X direction, as shown in Figure 20(b), multiple layers (two layers in Figure 20) of battery blocks 21 (or battery cells 22) are stacked in the Z direction. A small gap 211 is formed in the X direction between the multiple layers of battery blocks 21 and the single layer of battery blocks 21.

[0129] The battery control device 40 is located in the central passage 210. The location of the battery control device 40 in the central passage 210 is arbitrary; in Figure 20(a), it is located near the battery blocks 21 which are stacked in multiple layers.

[0130] The battery monitoring device 30 is fixed to the side of each battery block 21 facing the central passage 210. Also, as shown in Figure 20(b), the battery monitoring device 30 is fixed to the side of each battery block 21 that is mounted in multiple layers (the side facing the battery control device 40 in the X direction). In this modified example, the battery monitoring device 30 is fixed in a vertical orientation (the vertical direction of the monitoring circuit board 34 is the Y direction or the X direction), but the orientation can be changed as desired.

[0131] The battery monitoring device 30 and battery control device 40, located in the central passage 210, conduct wireless communication using the central passage 210 as the propagation path. In addition, the battery monitoring device 30, fixed to the side of each battery block 21 stacked in multiple layers, conducts wireless communication using the gap 211 formed between the stacked battery blocks 21 and a single battery block 21, and the space above the battery blocks 21, as the propagation path.

[0132] The junction box 60 is positioned at any location in the central passage 210. Since the junction box 60 is covered by a metal case (electromagnetic wave shielding member), it is possible to suppress the leakage of electromagnetic noise to the outside of the junction box 60. As a result, even when the central passage 210 is used as a radio wave propagation path, the influence of electromagnetic noise generated from the junction box 60 can be suppressed.

[0133] In the modified configurations shown in Figures 21(a) and 21(b), the arrangement of the battery block 21, battery monitoring device 30, and junction box 60 is the same as in the modified configuration shown in Figure 20. As shown in Figure 21(a), the battery control device 40 is fixed to the side of the multi-stage battery block 21 in the Y direction. The battery control device 40 utilizes the space above the battery block 21 as a radio wave propagation path.

[0134] In the modified versions shown in Figures 22(a) and 22(b), as shown in Figure 22(b), a housing case 250 with an L-shape (staircase shape) in side view (when viewed from the Y direction) is used. The battery blocks 21 (or battery cells 22) are aligned in the X direction so as to form one or more rows in the short direction (Y direction) of the housing case 250. In addition, at one end of the housing case 250 in the long direction (X direction), the battery blocks 21 (or battery cells 22) are stacked in multiple layers (two layers in Figure 22) in the vertical direction (Z direction).

[0135] As shown in Figure 22(b), a battery monitoring device 30 is fixed to the side of each battery block 21 (one side in the Y direction). A battery control device 40 is fixed to the side of the two stacked battery blocks 21 (the same side to which the battery monitoring device 30 is fixed). The battery control device 40 is positioned below the upper battery block 21 so as not to interfere with the battery monitoring device 30.

[0136] The battery monitoring device 30 and the battery control device 40 perform wireless communication within the housing case 250 by utilizing the space between the side wall 250b in the Y direction and the battery block 21, that is, the lateral space in the Y direction within the housing case 250 (battery housing space).

[0137] As shown in Figure 22(a), the junction box 60 is fixed to the side of the upper battery block 21 in the X direction of the two stacked battery blocks 21. In this modified example, an electromagnetic shield 201 is provided so as to cover the side of the junction box 60 in the Y direction that is on the side of the battery monitoring device 30 and the battery control device 40. This suppresses the radiation of electromagnetic noise from the side of the junction box 60 toward the side of the battery monitoring device 30 and the battery control device 40.

[0138] Furthermore, the X-direction side of the junction box 60 is covered by the battery block 21 or the side wall of the housing case 250. Therefore, the emission of electromagnetic noise from the X-direction side of the junction box 60 can be suppressed.

[0139] Furthermore, modified examples of Figure 22 are shown in Figures 23(a) and 23(b). The junction box 60 and the battery control device 40 may be arranged on one end of the housing case 250 in the X direction (opposite the two-tiered battery block 21), as shown in Figure 23(a). In this case, the battery control device 40 is placed directly above the junction box 60, and the electromagnetic shield 201 is placed so as to cover the top surface of the junction box 60. The battery control device 40 and the battery monitoring device 30 then use the space between the side wall 250b of the housing case 250 and the battery block 21 in the Y direction as a radio wave propagation path to perform wireless communication.

[0140] In the example shown in Figure 23(b), similar to Figure 23(a), the junction box 60 and battery control device 40 are positioned on one end of the housing case 250 in the X direction (opposite side from the two-tiered battery block 21). Also, in Figure 23(b), similar to Figure 23(a), the battery control device 40 is positioned directly above the junction box 60, and the electromagnetic shield 201 is positioned to cover the top surface of the junction box 60. Furthermore, in the example shown in Figure 23(b), the battery monitoring device 30 is positioned on the top surface of each battery block 21. Additionally, the battery monitoring device 30 is positioned on the X-direction side of the upper battery block 21. In the example shown in Figure 23(b), the battery control device 40 and battery monitoring device 30 utilize the space above the battery block 21 as a radio wave propagation path to perform wireless communication.

[0141] In the second embodiment and its modified form described above, as shown in Figure 24, a long, plate-shaped blade cell 260 extending in the Y direction of the housing case 50 may be used as the battery cell. This blade cell 260 is stacked in the X direction of the housing case 50. The electrode terminals of the blade cell 260 are arranged side by side on one or both sides in either the Y direction. The electrode terminals of the blade cell 260 may also be provided on the upper surface.

[0142] Furthermore, in the Y direction, multiple battery monitoring devices 30 are arranged on one side of the blade cell 260 (the right side in Figure 24). Also, at one end of the housing case 50 in the X direction, a junction box 60 and a battery control device 40 are arranged side by side in the Y direction. As shown in Figure 24, an electromagnetic shield 201 is placed between the junction box 60 and the battery control device 40, as described above, and the battery control device 40 is located on the side of the battery monitoring devices 30. The battery monitoring devices 30 and the battery control device 40 use the space on the side of the housing case 50 in the Y direction and above the blade cell 260 as radio wave propagation paths to perform wireless communication.

[0143] Furthermore, by locating the electrode terminals and busbars 23 of the blade cell 260 on the opposite side (left side in Figure 24) from the side where the battery monitoring device 30 is located in the Y direction, the influence of electromagnetic noise generated from the electrode terminals and busbars 23 can be suppressed.

[0144] In the second embodiment and its modified form described above, as shown in Figure 25, the battery blocks 21 may be arranged along the shorter direction (Y direction) of the housing case 50 so that there are multiple rows (four rows in Figure 25) along the longer direction (X direction). In this case, the battery cells 22 constituting each battery block 21 may be stacked in the Y direction such that their electrode terminals are gathered at one end in the X direction.

[0145] Furthermore, as shown in Figure 25, a communication path 270 may be provided in the center of the housing case 50 in the Y direction. The battery blocks 21 are arranged symmetrically with respect to the communication path 270. Also, as shown in the third row from the top in Figure 25, if the number of battery blocks 21 arranged in the Y direction is smaller than that of other rows, the battery blocks 21 are positioned closer to the central communication path 270.

[0146] In Figure 25, the battery monitoring device 30 is positioned along the communication path 270. The battery control device 40 is positioned side-by-side in the Y direction with respect to the junction box 60 at one end of the housing case 50 in the X direction. An electromagnetic shield 201 is provided between the battery control device 40 and the junction box 60, large enough to almost completely cover the side of the junction box 60 or the side of the ECU case 45. It is desirable that the battery control device 40 be positioned closer to the communication path 270 than the junction box 60. In Figure 25, the battery control device 40 is positioned on the communication path 270. The battery control device 40 and the battery monitoring device 30 perform wireless communication using the communication path 270 as the radio wave propagation path.

[0147] Furthermore, in the modified example shown in Figure 25, it is desirable that the electrode terminals of the battery cells 22 constituting the battery block 21 be provided on a surface that does not face the battery monitoring device 30 or the battery control device 40, such as the top surface. This makes it possible to suppress the influence of noise that may be generated from the electrode terminals and busbars 23.

[0148] In the second embodiment and its modifications described above, the shapes of the housing cases 50, 150, and 250 may be arbitrarily changed. For example, the housing case 251 shown in Figure 26(a) has a housing space 252 in a projection 250a that protrudes longitudinally from its side wall 50a. The battery control device 40 and the junction box 60 are housed in the housing space 252. This housing space 252 is separated from the space 254 in which the battery block 21 is housed by a partition plate 253 made of a material that allows radio waves to pass through (for example, resin), which closes the opening of the housing space 252.

[0149] The battery control device 40 transmits (passes through) radio waves via the partition plate 253 and communicates wirelessly with the battery monitoring device 30 located near the battery block 21. The junction box 60 can be enclosed in a metal case (electromagnetic wave shielding member).

[0150] Alternatively, the partition plate 253 of the housing space 252 may be made of an electromagnetic wave shielding material. In this case, an electromagnetic wave shield 201 is provided between the junction box 60 and the battery control device 40, and only the master unit-side wireless antenna 43 is placed in the space where the battery block 21 is housed. Alternatively, the partition plate 253 may be provided with a passage for radio waves to pass through, and radio waves may be input and output through this passage.

[0151] Furthermore, as shown in Figure 26(b), the housing case 255 may have the protruding portion 250a (i.e., the housing space 252) provided on the top surface instead of the side wall 50a.

[0152] In the second embodiment and its modified form described above, the arrangement may be changed as shown in Figure 27. The battery block 21 is aligned along the longitudinal direction (X direction) so as to form two rows in the short direction (Y direction) of the housing case 50. The battery block 21 is constructed by stacking a plurality of battery cells 22 in the X direction. In addition, the electrode terminals of each battery cell 22 are arranged in either one or both of the Y directions and connected to each other to constitute the battery block 21.

[0153] A central passageway 280 is provided in the center in the Y direction, and multiple battery monitoring devices 30 are arranged in the central passageway 280. In Figure 27, they are shown in a vertical orientation, but the orientation is arbitrary.

[0154] In Figure 27, the number of battery blocks 21 in the left column is one less than the number of battery blocks 21 in the right column, and a storage space is provided at the X-direction end. The battery control device 40 and the junction box 60 are arranged in this storage space. In the modified example shown in Figure 27, the junction box 60 is equipped with a metal case (electromagnetic wave shielding member), but an electromagnetic wave shield may be provided to separate it from the battery control device 40 and the battery monitoring device 30.

[0155] In the second embodiment and its modified form described above, the arrangement may be changed as shown in Figure 28. The battery block 21 is aligned along the longitudinal direction (X direction) so as to form two rows in the short direction (Y direction) of the housing case 50. The battery block 21 is composed of multiple battery cells 22 stacked in the Y direction. The electrode terminals of each battery cell 22 are provided on the upper surface (Z+ direction) and connected to each other to constitute the battery block 21.

[0156] A central passageway 290 is provided in the center in the Y direction, and multiple battery monitoring devices 30 are arranged in the central passageway 290. In Figure 28, they are shown in a vertical orientation, but the orientation is arbitrary.

[0157] In Figure 28, a junction box 60 is positioned near the center in the Y direction at the X-direction end of the housing case 50. A battery control device 40 is positioned next to it. In the modified example shown in Figure 28, the junction box 60 is equipped with a metal case (electromagnetic wave shielding member) to prevent electromagnetic noise from leaking to the outside. An electromagnetic shield may also be provided to separate the battery control device 40 and the battery monitoring device 30. In Figure 28, the space above the battery block 21 is used as a radio wave propagation path.

[0158] In the second embodiment and its modified form described above, the configuration of the electromagnetic wave shielding member may be arbitrarily changed. For example, as shown in Figure 29(a), the metal case 292 housing the circuit board 291 may be used as an electromagnetic wave shielding member interposed between the battery control device 40 (or battery monitoring device 30) and the junction box 60 which is a noise source. Note that the circuit board 291 in Figure 29(a) is, for example, a circuit board equipped with an abnormality monitoring device that detects the current value and commands current interruption if the value is abnormal.

[0159] In the second embodiment and its modified form described above, as shown in Figure 29(b), the heat sink 293 (conductor) used in the junction box 60 may be reused as an electromagnetic wave shielding member.

[0160] In the second embodiment and its modified form described above, the junction box 60 was identified as a noise source, but other sources may be identified and separated from each other by electromagnetic wave shielding members. Other noise sources besides the junction box 60 include, for example, the busbar 23 and power terminals from which current can flow from an external electrical load. If the busbar 23 and power terminals are identified as noise sources, they can be covered with a metal case or the like. If the electromagnetic wave intensity of the radiated noise is above a predetermined threshold, it can be considered a noise source.

[0161] In the above embodiments and modifications, the electromagnetic wave shielding member is not limited to metal, but may be coated with conductive paint or made of metal fibers. Furthermore, the electromagnetic wave shielding member may be a metal such as copper or aluminum that has a large reflection loss of electromagnetic waves, or a metal such as iron that has a large absorption loss of electromagnetic waves. Note that while electromagnetic noise refers to noise in the frequency band of approximately 300 Hz to 3 THz that interferes with RF signals, it may also include electromagnetic noise in other frequency bands.

[0162] In the second embodiment described above, it is not necessary to provide metal plates 37 and 47 that are proximity conductors that are close to the antennas 33 and 43 and electrostatically coupled.

[0163] (Third embodiment) The battery pack of the third embodiment will be described below.

[0164] As described in the first embodiment, the battery pack 11 and the battery cell 22 are generally equipped with explosion-proof valves to release gas when the internal pressure (more specifically, the pressure difference between the inside and outside) exceeds a specified value. Explosion-proof valves are described, for example, in Japanese Patent Application Publication No. 2020-074279. However, when performing wireless communication, there is a concern that if gas is ejected from such an explosion-proof valve, the gas may affect the wireless communication.

[0165] The third embodiment was made in view of the above circumstances, and its main purpose is to provide a battery pack 11 (power supply unit) that can suppress the impact on wireless communication even when gas is ejected from the explosion-proof valve.

[0166] The battery pack 11 of the third embodiment will be described in detail below with reference to Figure 30.

[0167] As shown in Figure 30, multiple battery blocks 21 are arranged side by side in the longitudinal direction (X direction) of the housing case 50. The battery control device 40 and the junction box 60 are positioned between one side wall 50a of the housing case 50 in the X direction and the side surface of the battery pack 20 (more specifically, the battery blocks 21 located at one end in the X direction). In the Y direction, the battery control device 40 is positioned side by side with the junction box 60. In Figure 30, the battery control device 40 is positioned near the right side wall 50b.

[0168] In the third embodiment, the cell explosion-proof valve 22a is provided on the upper surface of each battery cell 22, as in the first embodiment (see Figure 30), and the housing explosion-proof valve 51 is provided on the upper surface of the housing case 50, as in the first embodiment (shown by dashed lines). The housing explosion-proof valve 51 is provided in a position opposite (overlapping) each cell explosion-proof valve 22a in the vertical direction, but its arrangement can be arbitrarily changed. The size, number, and shape of the housing explosion-proof valve 51 can also be arbitrarily changed. For example, one large housing explosion-proof valve 51 may be provided in the center of the upper surface of the housing case 50. The battery control device 40 is positioned vertically, but its orientation can be arbitrary.

[0169] Meanwhile, as shown in Figure 30, the multiple battery monitoring devices 30 are arranged in the space between the right side wall 50b in the Y direction and the right side surface of each battery block 21. The battery monitoring devices 30 are positioned vertically, but their orientation can be changed as desired. The battery control device 40 and the battery monitoring devices 30 then use the space provided to the right of the battery block 21 as a radio wave propagation path (illustrated by a dashed line) to perform wireless communication.

[0170] According to the above embodiment, the following effects are achieved.

[0171] Each battery cell 22 is equipped with a cell explosion-proof valve 22a on its upper surface. As a result, gas from the cell explosion-proof valve 22a is discharged upwards on the battery block 21. Furthermore, a housing explosion-proof valve 51 is provided on the upper surface of the housing case 50. As a result, the gas discharged upwards on the battery block 21 is discharged through the housing explosion-proof valve 51, creating a structure that makes it difficult for gas to be discharged to the sides of the battery block 21.

[0172] On the other hand, the battery control device 40 and the battery monitoring device 30 use the space provided to the right of the battery block 21 as a radio wave propagation path to perform wireless communication. This allows the radio wave propagation path and the gas exhaust path to be separated, thereby suppressing interference with wireless communication.

[0173] The battery control device 40 and the battery monitoring device 30 are located to the side of the battery block 21. This prevents gas from being directly injected into the battery monitoring device 30 or the battery control device 40 from the cell explosion-proof valve 22a. Therefore, it is possible to suppress malfunctions of the battery monitoring device 30 or the battery control device 40 due to gas.

[0174] On the upper surface of the housing case 50, the area where the housing explosion-proof valve 51 is installed is, due to its structure, thinner than other parts of the housing case 50, such as the sides, making it more susceptible to external electromagnetic noise. For this reason, the battery monitoring device 30 and the battery control device 40 are installed in a different location from where the housing explosion-proof valve 51 is installed, that is, in a location that does not overlap with the area of ​​the housing explosion-proof valve 51 in the vertical direction (Z direction). This makes it possible to suppress the influence of external noise.

[0175] Furthermore, the space provided to the right of the battery block 21 is located in a different position from the location where the housing explosion-proof valve 51 is installed; that is, it does not overlap with the area of ​​the housing explosion-proof valve 51 in the vertical direction (Z direction). When wireless communication is performed using the space provided to the right of the battery block 21 as a radio wave propagation path, the influence of electromagnetic noise entering through the housing explosion-proof valve 51 can be suppressed.

[0176] Furthermore, the housing explosion-proof valve 51 faces the upper surface of the battery cell 22, and the battery monitoring device 30 and battery control device 40 are not positioned between the housing explosion-proof valve 51 and the battery cell 22. As a result, electromagnetic noise that enters from the outside through the housing explosion-proof valve 51 is easily reflected by the battery cell 22 (or its battery case) and released back to the outside through the housing explosion-proof valve 51. In other words, the battery cell 22 blocks the path of electromagnetic noise that enters from the outside through the housing explosion-proof valve 51, thereby suppressing the impact on wireless communication.

[0177] (Modified version of the third embodiment) The following describes a modified example in which some of the configurations of the battery pack 11 in the third embodiment have been changed.

[0178] In the above embodiments and modifications, the cell explosion-proof valve 22a may be provided on the side of the battery cell 22. That is, it may be provided on either the side in the X direction or the side in the Y direction. In this case, the battery monitoring device 30 and the battery control device 40 should be positioned facing the side where the cell explosion-proof valve 22a is not provided. Alternatively, the battery monitoring device 30 and the battery control device 40 may be positioned on the upper surface of the battery cell 22.

[0179] For example, let's consider a case where, as shown in Figure 31(a), the battery cells 22 are arranged in a line in the X direction, and a cell explosion-proof valve 22a is provided on one side of each battery cell 22 in the Y direction (the side facing the viewer in Figure 31(a)). In this case, as shown in Figure 31(a), the battery monitoring device 30 should be placed on the top surface of the battery cell 22, and the battery control device 40 should be placed adjacent to the side of the battery cell 22 in the X direction. In other words, the battery monitoring device 30 and the battery control device 40 should not be placed in a position facing the cell explosion-proof valve 22a. Although not shown, the battery monitoring device 30 and the battery control device 40 may also be placed on the opposite side of the battery cell 22 in the Y direction (the side on which the cell explosion-proof valve 22a is not provided).

[0180] In the above embodiments and modifications, it is preferable that the housing explosion-proof valve 51 is provided on the surface opposite to the surface where the cell explosion-proof valve 22a is located. More preferably, it is preferable that the housing explosion-proof valve 51 is provided at a position opposite to the cell explosion-proof valve 22a. In this case, it is preferable that there is nothing obstructing the space between the cell explosion-proof valve 22a and the housing explosion-proof valve 51.

[0181] For example, as shown in Figure 31(a), if a cell explosion-proof valve 22a is provided on the side of each battery cell 22, a housing explosion-proof valve 51 (shown by a dashed line) may be provided on the side wall of the housing case 50 facing the cell explosion-proof valve 22a.

[0182] As shown in Figure 31(b), when viewing the inside of the battery pack 11 from above, the gap between the right side of each battery cell 22 and the right side wall 50b of the housing case 50 may be used as a gas discharge passage 301. This gas discharge passage 301 will be formed to extend in the X direction. Furthermore, a housing explosion-proof valve 51 may be provided on the side wall 50a of the housing case 50 where the gas discharge passage 301 abuts in the X direction. In this case, the gas discharged from the right side of the battery cell 22 will pass through the gas discharge passage 301 and be discharged to the outside through the housing explosion-proof valve 51 provided on the side wall 50a of the housing case 50 in the X direction. In addition, if the housing explosion-proof valve 51 is provided on the side wall 50a opposite to the battery control device 40 in the X direction, it is possible to suppress the accumulation of gas around the battery control device 40.

[0183] In the above embodiments and modifications, the battery monitoring device 30 and the battery control device 40 may be positioned opposite the surface on which the cell explosion-proof valve 22a is provided. In this case, the battery monitoring device 30 and the battery control device 40 are positioned at different locations so as not to face the cell explosion-proof valve 22a.

[0184] Here, we will explain in detail with reference to Figure 32. In Figure 32, multiple battery blocks 21 are arranged in the X direction. In each battery block 21, multiple battery cells 22 are arranged in the Y direction, and a cell explosion-proof valve 22a is provided on one side in the X direction (the right side in Figure 32) on the upper surface of each battery cell 22.

[0185] The battery monitoring device 30 is positioned on the upper surface of the battery cell 22, on the other side in the X direction (the left side in Figure 32). In other words, the battery monitoring device 30 is located on the upper surface of the battery cell 22 at a different position from the cell explosion-proof valve 22a (not facing the cell explosion-proof valve 22a and not overlapping in the Z direction (vertical direction)). As shown in Figure 32, the battery monitoring device 30 may be positioned across multiple battery cells 22. Also, in Figure 32, the battery control device 40 is positioned to the side of the battery block 21 in the Y direction. This prevents gas from being directly injected into the battery monitoring device 30 or the battery control device 40 even if gas is discharged from the cell explosion-proof valve 22a.

[0186] Furthermore, the explosion-proof valve 51 of the housing case 50 is located on the upper surface of the housing case 50, approximately directly above each cell explosion-proof valve 22a (not shown). As a result, the gas is discharged upwards above the battery cells 22, preventing the gas from interfering with the radio wave propagation path. An example of the radio wave propagation path is shown by a dashed line in Figure 32.

[0187] In the above embodiments and modifications, the cell explosion-proof valve 22a and the housing explosion-proof valve 51 may each be provided on the lower surface (Z-direction surface) of the housing case 50. In this case, the battery monitoring device 30 and the battery control device 40 may be provided above or to the side of the battery block 21, that is, not below the battery block 21. This allows for the separation of the radio wave propagation path and the gas discharge path. It also prevents gas from being directly injected from the cell explosion-proof valve 22a into the battery monitoring device 30 and the battery control device 40.

[0188] In the above embodiments and modifications, a smoke exhaust duct may be provided to guide the gas discharged from the cell explosion-proof valve 22a of the battery cell 22 to the housing explosion-proof valve 51 of the housing case 50. It is desirable that this smoke exhaust duct be provided so as not to interfere with (cross) the radio wave propagation path.

[0189] Here, we will explain in detail with reference to Figure 33. In the modified example shown in Figure 33, multiple battery blocks 21 are arranged in the X direction. In each battery block 21, multiple battery cells 22 are arranged in the Y direction, and a cell explosion-proof valve 22a is provided on one side in the X direction (the right side in Figure 33) on the upper surface of each battery cell 22. Note that in Figure 33, the cell explosion-proof valve 22a is shown with a dashed line.

[0190] The battery monitoring device 30 is located on the upper surface of the battery cell 22, on the other side in the X direction (the left side in Figure 33). In other words, the battery monitoring device 30 is located on the upper surface of the battery cell 22 at a different position from the cell explosion-proof valve 22a (not facing the cell explosion-proof valve 22a and not overlapping in the Z direction). Also in Figure 33, the battery control device 40 is located to the side of the battery block 21 in the Y direction.

[0191] The exhaust duct 350 is configured as a cylindrical shape extending linearly in the Y direction and is positioned directly above each cell explosion-proof valve 22a in the vertical direction. The exhaust duct 350 is generally made of metal. The exhaust duct 350 is provided for each battery block 21 and extends over the cell explosion-proof valves 22a of the multiple battery cells 22 that make up the battery block 21. In the modified example shown in Figure 32, it is provided so as to cover the cell explosion-proof valves 22a of all the battery cells 22 that make up the battery block 21.

[0192] The exhaust duct 350 has a through-hole at a location corresponding to the cell explosion-proof valve 22a. When the cell explosion-proof valve 22a is opened, the inside of the battery cell 22 and the exhaust duct 350 are connected through this through-hole. Therefore, the gas discharged from the cell explosion-proof valve 22a is discharged into the exhaust duct 350. The exhaust duct 350 is formed to extend toward the housing explosion-proof valve 51 provided on the side wall 50b of the housing case 50, and opens at a position corresponding to the housing explosion-proof valve 51. In other words, in the Y direction, the end of the exhaust duct 350 on the side of the housing explosion-proof valve 51 is open and connected to the housing explosion-proof valve 51. Therefore, the gas that passes through the exhaust duct 350 is discharged to the outside through the housing explosion-proof valve 51. In the Y direction, the end of the exhaust duct 350 opposite to the housing explosion-proof valve 51 is closed.

[0193] On the other hand, the battery monitoring device 30 is positioned on the upper surface of the battery cell 22, on the other side in the X direction (the left side in Figure 33). In other words, the battery monitoring device 30 is positioned on the upper surface of the battery cell 22 in a location that does not interfere with the exhaust duct 350. Also, in Figure 33, the battery control device 40 is positioned to the side of the battery block 21 in the Y direction, on the opposite side from the housing explosion-proof valve 51. This prevents gas from being directly injected into the battery monitoring device 30 or the battery control device 40 even if gas is discharged from the cell explosion-proof valve 22a.

[0194] Furthermore, the radio wave propagation path between the battery control device 40 and the battery monitoring device 30 is set so as not to intersect with the exhaust duct 350. For example, the propagation path shown by the dashed arrow in Figure 33 runs parallel to the exhaust duct 350. This prevents gas from interfering with the propagation path, allowing for optimal wireless communication.

[0195] Furthermore, the smoke exhaust duct 350 extends to the housing explosion-proof valve 51 located on the side wall 50b of the housing case 50. The smoke exhaust duct 350 is made of metal. Therefore, even if the housing explosion-proof valve 51 opens and external electromagnetic noise can easily enter, the housing explosion-proof valve 51 is covered by the metal smoke exhaust duct 350, preventing leakage to the outside of the smoke exhaust duct 350. In other words, the smoke exhaust duct 350 can function as an electromagnetic shield that blocks electromagnetic noise entering from the housing explosion-proof valve 51. This suppresses the influence of external electromagnetic noise on the battery control device 40 and battery monitoring device 30, which are located outside the smoke exhaust duct 350.

[0196] In the above embodiments and modifications, the battery cell 22 may be made of long, plate-shaped blade cells. In this case, for example, as shown in Figure 34, a plurality of blade cells 401 are stacked in a predetermined direction (Z direction (up and down direction) in Figure 34) to form a battery block 421. The blade cell 401 in Figure 34 has a positive electrode terminal 404a at one end in the longitudinal direction and a negative electrode terminal 404b at the other end. For this reason, the battery monitoring device 30 is positioned in the longitudinal center of the blade cell 401, and positive electrode detection lines 402 and negative electrode detection lines 403 extend from the longitudinal center to both sides in the longitudinal direction, respectively, and are connected to their respective electrode terminals 404a and 404b. This makes it possible to make the wiring resistance of the positive electrode detection line 402 connected to the positive electrode side the same as the wiring resistance of the negative electrode detection line 403 connected to the negative electrode side, thereby preventing deterioration of detection accuracy.

[0197] In Figure 34, the battery monitoring device 30, the positive electrode detection line 402, and the negative electrode detection line 403 are located on the upper surface of the battery block 421. The positive electrode detection line 402 and the negative electrode detection line 403 are located in the middle of the battery block 421 in the width direction (direction perpendicular to the longitudinal direction). On the other hand, the battery monitoring device 30 is positioned offset from the positive electrode detection line 402 and the negative electrode detection line 403 in the width direction.

[0198] The wireless circuit 410 (shown by a dashed line) of the battery monitoring device 30 is located on the monitoring circuit board 34 on the opposite side in the width direction from the connection points of the positive electrode detection line 402 and the negative electrode detection line 403. In other words, the wireless circuit 410 is positioned as far away as possible from the noisy positive electrode detection line 402 and the negative electrode detection line 403. The wireless circuit 410 consists of circuit elements related to wireless communication, including the slave unit wireless antenna 33, the slave unit wireless IC 32, and the front-end circuit.

[0199] In Figure 34, the explosion-proof valve 401a of the blade cell 401 is provided on the end face in the longitudinal direction. This prevents gas from the explosion-proof valve 401a from being directly injected into the battery monitoring device 30 located on the upper surface of the battery block 421. It also prevents gas from entering the radio wave propagation path.

[0200] In the third embodiment described above, it is not necessary to provide metal plates 37 and 47 which are proximity conductors that are close to the antennas 33 and 43 and electrostatically coupled. Also, in the third embodiment described above, it is not necessary to provide an electromagnetic shielding member, such as an electromagnetic shield 201, that blocks electromagnetic noise from noise sources placed in the battery housing space.

[0201] Furthermore, the above embodiments and their modifications can be combined and implemented to the extent possible.

[0202] For example, in the battery monitoring device 30 and battery control device 40 described in the second embodiment (and its modified versions, hereinafter the same) and the third embodiment (and its modified versions, hereinafter the same), the internal structure of the battery monitoring device 30 or battery control device 40 of the first embodiment (and its modified versions), specifically the structure of the antennas 33, 43 and the metal plates 37, 47, may be adopted.

[0203] Furthermore, the configurations and arrangements of the housing explosion-proof valve 51 and cell explosion-proof valve 22a described in the third embodiment may be appropriately adopted in the housing case 50 and battery cell 22 of the first embodiment (and its modified versions, hereinafter the same) and the second embodiment. For example, in the first and second embodiments, similar to the third embodiment, it is naturally possible to derive a configuration in which the cell explosion-proof valve 22a is provided on the upper surface or side of the battery cell 22, and the housing explosion-proof valve 51 is provided on the upper surface (center of the upper surface) or side of the housing case 50.

[0204] Furthermore, in the first and second embodiments, similar to the third embodiment, the housing explosion-proof valve 51 and the cell explosion-proof valve 22a may be arranged to avoid the radio wave propagation path between the battery monitoring device 30 and the battery control device 40. Also, in the first and second embodiments, similar to the third embodiment, the battery monitoring device 30 (or battery control device 40) may be arranged to avoid the housing explosion-proof valve 51 and the cell explosion-proof valve 22a.

[0205] Furthermore, in the first and second embodiments, similar to the third embodiment, configurations such as a gas exhaust passage 301 and a smoke exhaust duct 350 may be adopted to suppress the impact of exhaust gas on wireless communication.

[0206] In addition, all of the first, second, and third embodiments may be combined.

[0207] The following describes the characteristic configurations extracted from each of the embodiments described above.

[0208] [Configuration 1] In the wireless devices (30, 40) of the battery monitoring system (100), Wireless antennas (33, 43) and A wireless device comprising: a proximity conductor (37, 47) that overlaps with at least a portion of the projection plane of the wireless antenna when a predetermined direction is used as the projection direction.

[0209] [Configuration 2] The circuit board (34, 44) on which the wireless antenna is mounted is provided. The wireless device according to configuration 1, wherein the proximity conductor is positioned closest to the wireless antenna compared to other conductors, excluding those mounted on the circuit board.

[0210] [Configuration 3] The wireless device according to configuration 2, wherein the predetermined direction is the direction perpendicular to the circuit board.

[0211] [Structure 4] The wireless device according to any one of configurations 1 to 3, wherein the projection surface of the wireless antenna in the predetermined direction is the largest surface compared to the projection surface in other directions.

[0212] [Composition 5] The wireless device according to any one of configurations 2 to 4, wherein the adjacent conductor is in the shape of a flat plate, and its plane is arranged parallel to the circuit board.

[0213] [Composition 6] The wireless antenna comprises elements (33a, 43a) for radiating radio waves and wiring patterns (33b, 43b) arranged opposite to the elements. The wiring pattern has a potential corresponding to the reference potential of the circuit board. The wireless device according to configuration 2 or 3, wherein the adjacent conductor is located on the opposite side of the circuit board from the surface on which the element is arranged.

[0214] [Composition 7] The wireless IC (32, 42) is connected to the aforementioned wireless antenna, In the circuit board, the wireless IC is arranged on the side opposite to the side on which the elements are arranged. The wireless device according to configuration 6, wherein the proximity conductor is configured to cover the wireless IC.

[0215] [Structure 8] A wireless device according to any one of configurations 1 to 7, wherein in the predetermined direction, the entire projection surface of the wireless antenna overlaps with the adjacent conductor.

[0216] [Composition 9] The wireless device according to any of configurations 1 to 8, wherein the adjacent conductor constitutes a part of the housing of the wireless device.

[0217] [Configuration 10] The wireless device according to any one of configurations 1 to 9, wherein the housing of the wireless device is provided with a passage for allowing radio waves from the wireless antenna to pass through.

[0218] [Composition 11] The wireless device according to configuration 10, wherein the passing portion is located on the side of the communication partner than the wireless antenna, and is provided on the opposite side from the adjacent conductor with respect to the wireless antenna.

[0219] [Composition 12] The wireless device according to configuration 10 or 11, wherein in an orthogonal direction perpendicular to the predetermined direction, the width dimension of the passing portion is 1 / 2 or more of the wavelength of the radio waves radiated from the wireless antenna.

[0220] [Composition 13] A wireless device according to any one of configurations 10 to 12, wherein, in the predetermined direction, no conductor is placed on the side opposite the adjacent conductor to the wireless antenna, or, if a conductor is placed, the distance between the conductor and the wireless antenna is 1 / 2 or more of the wavelength of the radio waves radiated from the wireless antenna.

[0221] [Composition 14] The wireless device according to configuration 13, wherein, in the predetermined direction, the distance between the housing of the wireless device and the wireless antenna is 1 / 2 or more of the wavelength of the radio waves radiated from the wireless antenna.

[0222] [Composition 15] The wireless antenna comprises elements (33a, 43a) for radiating radio waves and wiring patterns (33b, 43b) arranged opposite to the elements. The aforementioned wiring pattern has a potential corresponding to the reference potential of the circuit board on which the wireless antenna is mounted. The aforementioned wiring pattern has a comb-tooth shape or a meander shape. The wireless device according to any one of configurations 1 to 14, wherein the projection surface of the wireless antenna includes at least the projection surface of the element and the projection surface of the wiring pattern.

[0223] [Composition 16] The wireless antenna comprises elements (33a, 43a) for radiating radio waves and wiring patterns (33b, 43b) arranged opposite to the elements. The aforementioned wiring pattern has a potential corresponding to the reference potential of the circuit board on which the wireless antenna is mounted. The element has at least one of the following shapes: comb shape, L shape, and stub shape. The wireless device according to any one of configurations 1 to 15, wherein the projection surface of the wireless antenna includes at least the projection surface of the element and the projection surface of the wiring pattern.

[0224] [Composition 17] A wireless device according to any one of configurations 1 to 16, comprising insulating sheets (36, 46) between the wireless antenna and the adjacent conductor.

[0225] [Composition 18] The wireless device according to any one of configurations 1 to 7, wherein the capacitance generated between the adjacent conductor and the wireless antenna is larger than the capacitance generated between other conductors and the wireless antenna.

[0226] [Composition 19] A power supply unit (11) having a plurality of wireless devices (30, 40) described in any of configurations 1 to 18, and a battery unit (20, 21, 22), which transmits and receives battery information between the wireless devices via wireless communication, Equipped with a noise source (60) that generates electromagnetic noise, A power supply unit in which multiple wireless devices and noise sources are all arranged within the battery housing space of the power supply unit, and an electromagnetic wave shielding member (201) is interposed between the wireless devices and the noise sources.

[0227] [Configuration 20] The housing (35, 45) of the wireless device is provided with a passage section for allowing radio waves to pass through. The power supply unit according to configuration 19, wherein the passing section is located on the side of the communication partner than the wireless antenna (33, 43) of the wireless device in the radio wave propagation path, and is positioned on the opposite side of the noise source with respect to the wireless antenna.

[0228] [Composition 21] The power supply unit according to configuration 19 or 20, wherein the surface on the noise source side of the surface constituting the housing of the wireless device is the electromagnetic wave shielding member.

[0229] [Composition 22] The wireless device has an antenna that emits radio waves with directionality. A power supply unit according to any one of configurations 19 to 21, wherein the direction of the antenna is determined and arranged such that the direction in which the radio waves radiated from the antenna are strong is directed toward the communication partner, but not toward the noise source.

[0230] [Composition 23] The power supply unit according to configuration 22, wherein the direction of the antenna is determined and arranged such that the direction in which the radio waves radiated from the antenna are strong does not face the electromagnetic wave shielding member.

[0231] [Composition 24] The housing of the wireless device is positioned adjacent to any of the battery cells constituting the battery section, or adjacent to the side wall that divides the battery housing space. The power supply unit according to configuration 22 or 23, wherein the direction of the antenna is determined and arranged such that the direction in which the radio waves radiated from the antenna are strong does not face the battery cell and the side wall.

[0232] [Composition 25] The aforementioned battery unit is composed of a plurality of battery cells (22), The noise source is a junction box (60) having one or more relay switches (61) that switch between energizing and disconnecting the battery section. The wireless device includes a battery monitoring device (30) provided for each of one or more battery cells, which acquires and transmits battery information, and a battery control device (40) which receives battery information from the battery monitoring device. The battery control device is positioned closer to the junction box than the battery monitoring device, and acquires the total voltage of the battery section from the junction box. The power supply unit according to any one of configurations 19 to 24, wherein the electromagnetic wave shielding member is provided between the battery control device and the junction box.

[0233] [Composition 26] In the battery housing space, the battery control device is positioned above the junction box, and communication is performed by reflecting radio waves off the ceiling surface of the battery housing space, as described in configuration 25 of the power supply unit.

[0234] [Composition 27] The battery unit and the wireless device are housed in a case, The noise source is fixed to the outside of the case. A power supply unit according to any of configurations 19 to 26, wherein the fixed surface of the noise source constituting the case is the electromagnetic wave shielding member.

[0235] [Composition 28] A power supply unit (11) having a plurality of wireless devices (30, 40) described in any of configurations 1 to 18, and a battery unit (20, 21, 22), which transmits and receives battery information between the wireless devices via wireless communication, The battery section is provided with an explosion-proof valve (22a). The explosion-proof valve is positioned to avoid the propagation path of radio waves emitted from the wireless device within the power supply unit.

[0236] [Composition 29] The power supply unit according to configuration 28, wherein the wireless device is positioned to avoid being opposite the explosion-proof valve.

[0237] [Composition 30] The explosion-proof valve is provided on either the side, top, or bottom of the battery section. The wireless device is positioned opposite to a surface other than the installation surface of the explosion-proof valve, and is a power supply unit according to configuration 28 or 29.

[0238] [Composition 31] The wireless device and the battery unit are housed in a housing case (50), The storage case has an opening (51) that opens due to the internal pressure of the storage case, The opening is positioned opposite the explosion-proof valve, and is a power supply unit according to any one of configurations 28 to 30.

[0239] [Composition 32] The opening of the aforementioned storage case is provided on its upper surface, The wireless device is positioned to avoid the space between the battery section and the top surface of the housing case, as described in configuration 31.

[0240] [Configuration 33] The wireless device and the battery unit are housed in a housing case (50), The storage case has an opening (51) that opens due to the internal pressure of the storage case, The opening is positioned so as not to face the explosion-proof valve, and a predetermined exhaust path is provided through which the gas discharged from the explosion-proof valve passes before reaching the opening. The wireless device is a power supply unit according to any of configurations 28 to 32, which is positioned to avoid the smoke exhaust path.

[0241] [Configuration 34] The explosion-proof valve is provided on the side of the battery unit. The opening is provided on the side wall of the housing case. The smoke exhaust path is formed between the side of the battery unit and the side wall of the housing case. The wireless device is disposed above the battery unit, and the propagation path is above the battery unit. The power supply unit according to Configuration 33.

[0242] [Configuration 35] The battery unit is disposed opposite to the opening, and between the opening and the battery unit, there is no wireless device and propagation path provided. The power supply unit according to Configuration 33 or 34.

[0243] [Configuration 36] It includes a smoke exhaust duct (350) through which the gas discharged from the explosion-proof valve passes. The wireless device is disposed at a position different from the smoke exhaust duct. The power supply unit according to any one of Configurations 28 to 35.

[0244] [Configuration 37] The smoke exhaust duct is disposed in parallel with the propagation path. The power supply unit according to Configuration 36.

[0245] [Configuration 38] When the explosion-proof valve is opened, the mouth of the explosion-proof valve communicates with the inside of the smoke exhaust duct. The power supply unit according to Configuration 36 or 37.

[0246] [Configuration 39] It includes a housing case (50) for housing the wireless device and the battery unit. The housing case has an opening (51) that opens by the internal pressure of the housing case. The smoke exhaust duct is a metal pipe, and the opening and the end of the smoke exhaust duct are connected so that the opening and the inside of the smoke exhaust duct communicate with each other. The power supply unit according to any one of Configurations 36 to 38.

[0247] [Configuration 201] In a power supply unit (11) having battery sections (20, 21, 22), Multiple wireless devices (30, 40) that transmit and receive battery information wirelessly, A noise source (60) that generates electromagnetic noise, A power supply unit in which multiple wireless devices and noise sources are all arranged within the battery housing space of the power supply unit, and an electromagnetic wave shielding member (201) is interposed between the wireless devices and the noise sources.

[0248] [Configuration 202] The housing (35, 45) of the wireless device is provided with a passage section for allowing radio waves to pass through. The power supply unit according to configuration 201, wherein the passing section is located on the side of the communication partner rather than the wireless antenna (33, 43) of the wireless device in the radio wave propagation path, and is positioned on the opposite side of the noise source with respect to the wireless antenna.

[0249] [Configuration 203] The power supply unit according to configuration 201 or 202, wherein the surface on the noise source side of the surface constituting the housing of the wireless device is the electromagnetic wave shielding member.

[0250] [Configuration 204] The wireless device has an antenna that emits radio waves with directionality. A power supply unit according to any of configurations 201 to 203, wherein the direction of the antenna is determined and arranged such that the direction in which the radio waves radiated from the antenna are strongest is directed toward the communication partner, but not toward the noise source.

[0251] [Configuration 205] The power supply unit according to configuration 204, wherein the direction of the antenna is determined and arranged such that the direction in which the radio waves radiated from the antenna are strong does not face the electromagnetic wave shielding member.

[0252] [Configuration 206] The housing of the wireless device is arranged adjacent to any one of the battery cells constituting the battery unit or adjacent to the side wall partitioning the battery accommodation space. The power supply unit according to Configuration 204 or 205, wherein the direction of the antenna is determined and arranged such that the direction in which the radio wave radiated from the antenna is strong does not face the battery cell and the side wall.

[0253] [Configuration 207] The battery unit is composed of a plurality of battery cells (22). The noise source is a junction box (60) having one or more relay switches (61) for switching on and off the power supply in the battery unit. The wireless device includes a battery monitoring device (30) provided for each one or more battery cells to acquire and transmit battery information, and a battery control device (40) for receiving the battery information from the battery monitoring device. The battery control device is arranged closer to the junction box than the battery monitoring device, and acquires the total voltage of the battery unit from the junction box. The power supply unit according to any one of Configurations 201 to 206, wherein the electromagnetic wave shielding member is provided between the battery control device and the junction box.

[0254] [Configuration 208] In the battery accommodation space, the battery control device is arranged above the junction box, and communicates by reflecting radio waves from the ceiling surface of the battery accommodation space. The power supply unit according to Configuration 207.

[0255] [Configuration 209] A case for housing the battery unit and the wireless device is provided. The noise source is fixed to the outside of the case. The power supply unit according to Configuration 201, wherein the fixing surface of the noise source constituting the case is the electromagnetic wave shielding member.

[0256] [Configuration 301] In a power supply unit (11) having a battery section (22), The system includes multiple wireless devices (30, 40) that transmit and receive battery information wirelessly. The battery section is provided with an explosion-proof valve (22a). The explosion-proof valve is positioned to avoid the propagation path of radio waves emitted from the wireless device within the power supply unit.

[0257] [Configuration 302] The power supply unit according to configuration 301, wherein the wireless device is positioned to avoid being opposite the explosion-proof valve. [Configuration 303] The explosion-proof valve is provided on either the side, top, or bottom of the battery section. The wireless device is a power supply unit according to configuration 301 or 302, which is positioned opposite to a surface other than the installation surface of the explosion-proof valve.

[0258] [Configuration 304] The wireless device and the battery unit are housed in a housing case (50), The storage case has an opening (51) that opens due to the internal pressure of the storage case, The opening is positioned opposite the explosion-proof valve, and is a power supply unit according to any one of configurations 301 to 303.

[0259] [Configuration 305] The opening of the aforementioned storage case is provided on its upper surface, The wireless device is positioned to avoid the space between the battery section and the top surface of the housing case, as described in configuration 304.

[0260] [Configuration 306] The wireless device and the battery unit are housed in a housing case (50), The storage case has an opening (51) that opens due to the internal pressure of the storage case, The opening is positioned so as not to face the explosion-proof valve, and a predetermined exhaust path is provided through which the gas discharged from the explosion-proof valve passes before reaching the opening. The wireless device is a power supply unit according to any of configurations 301 to 305, which is positioned to avoid the smoke exhaust path.

[0261] [Configuration 307] The explosion-proof valve is provided on the side of the battery section, The aforementioned opening is provided in the side wall of the storage case, The exhaust path is formed between the side of the battery section and the side wall of the housing case. The power supply unit according to configuration 306, wherein the wireless device is positioned above the battery section, and the propagation path is above the battery section.

[0262] [Configuration 308] A power supply unit according to any one of configurations 304 to 307, wherein the battery section is positioned opposite the opening, and the wireless device and the propagation path are not provided between the opening and the battery section.

[0263] [Configuration 309] The system includes a smoke exhaust duct (350) through which the gas discharged from the explosion-proof valve passes, The wireless device is a power supply unit according to any of configurations 301 to 308, located in a position different from the exhaust duct.

[0264] [Configuration 310] The exhaust duct is arranged in parallel with the propagation path, and is the power supply unit according to configuration 309.

[0265] [Configuration 311] The power supply unit according to configuration 309 or 310, wherein when the explosion-proof valve is opened, the opening of the explosion-proof valve communicates with the inside of the exhaust duct.

[0266] [Configuration 312] The wireless device and the battery unit are housed in a housing case (50), The storage case has an opening (51) that opens due to the internal pressure of the storage case, The power supply unit according to any one of configurations 309 to 311, wherein the exhaust duct is a metal pipe, and the end of the exhaust duct is connected to the opening so that the opening and the inside of the exhaust duct are in communication. [Explanation of symbols]

[0267] 11...Battery pack (power unit), 20...Battery assembly, 21...Battery block, 22...Battery cell, 22a...Cell explosion-proof valve, 23...Bus bar, 30...Battery monitoring device (wireless device), 31...Monitoring IC, 32...Slave-side wireless IC, 33...Slave-side wireless antenna, 33a, 43a...Element, 33b, 43b...Ground plate, 34...Monitoring circuit board, 35...SBM case, 37, 47...Metal plate (proximity conductor) 40...Battery control device (wireless device), 42...Master unit wireless IC, 43...Master unit wireless antenna, 44...Control circuit board, 45...ECU case, 50, 150, 250, 251, 255...Housing case, 51...Explosion-proof valve for housing, 60...Junction box (noise source), 100...Battery monitoring system, 201...Electromagnetic shield (electromagnetic wave shielding material), 260...Blade cell, 350...Smoke exhaust duct.

Claims

1. In a power supply unit (11) having battery sections (20, 21, 22), Multiple wireless devices (30, 40) that transmit and receive battery information wirelessly, A noise source (60) that generates electromagnetic noise, The battery unit or the wireless device is housed in a housing (35, 45), The noise source is fixed to the outside of the housing, Multiple wireless devices and noise sources are all arranged within the battery housing space of the power supply unit, and an electromagnetic wave shielding member (201) is interposed between the wireless devices and the noise sources. A power supply unit in which the fixing surface of the noise source constituting the housing is the electromagnetic wave shielding member.

2. The housing (35, 45) of the wireless device is provided with a passage section for allowing radio waves to pass through, The power supply unit according to claim 1, wherein the passing section is located on the side of the communication partner rather than the wireless antennas (33, 43) of the wireless device in the radio wave propagation path, and is positioned on the opposite side of the noise source with respect to the wireless antennas.

3. The power supply unit according to claim 1, wherein the surface on the noise source side of the surface constituting the housing of the wireless device is the electromagnetic wave shielding member.

4. The wireless device has an antenna that emits radio waves with directionality. The power supply unit according to claim 1, wherein the direction of the antenna is determined and arranged such that the direction in which the radio waves radiated from the antenna are strongest is directed toward the communication partner, but not toward the noise source.

5. The power supply unit according to claim 4, wherein the direction of the antenna is determined and arranged such that the direction in which the radio waves radiated from the antenna are strong does not face the electromagnetic wave shielding member.

6. The housing of the wireless device is positioned adjacent to any of the battery cells constituting the battery section, or adjacent to the side wall that divides the battery housing space. The power supply unit according to claim 4, wherein the direction of the antenna is determined and arranged such that the direction in which the radio waves emitted from the antenna are strong does not face the battery cell and the side wall.

7. The aforementioned battery unit is composed of a plurality of battery cells (22), The noise source is a junction box (60) having one or more relay switches (61) that switch between energizing and disconnecting the battery section. The wireless device includes a battery monitoring device (30) provided for each of one or more battery cells, which acquires and transmits battery information, and a battery control device (40) which receives battery information from the battery monitoring device. The battery control device is positioned closer to the junction box than the battery monitoring device, and acquires the total voltage of the battery section from the junction box. The power supply unit according to any one of claims 1 to 6, wherein the electromagnetic wave shielding member is provided between the battery control device and the junction box.

8. The power supply unit according to claim 7, wherein in the battery housing space, the battery control device is positioned above the junction box, and communication is performed by reflecting radio waves off the ceiling surface of the battery housing space.

9. The facility includes a housing case (251) that forms a battery housing space (254) for housing the aforementioned battery unit, The noise source is housed in a housing space (252) of a protrusion (250a) that is formed to protrude outward from the side wall or top surface of the housing case. The power supply unit according to any one of claims 1 to 6, wherein the space between the housing of the protruding portion and the battery housing space is separated by a partition plate (253) which is an electromagnetic wave shielding member.

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