Battery module

Abstract

The first end face (50a) of multiple battery cells (50) and the inner top face (131a) of the top wall (131) are separated and opposed in the z direction. A negative terminal (51) and a positive terminal (52) separated in the x direction are formed on the first end face. The above terminals are connected to a bus bar (70). A waveguide path (160) is defined between these bus bars separated in the x direction and between the first end face and the inner top face separated in the z direction. A separate communication unit (110) that performs wireless communication with the unified monitoring unit (30) is provided in the waveguide path. The length of the waveguide path in the x direction is longer than half of the wavelength of the wireless signal and shorter than an integer multiple. The length of the waveguide path in the z direction is longer than the length in the x direction.

Description

[0001] Citation of Related Applications

[0002] This application is based on Japanese Patent Application No. 2020-026954 filed on February 20, 2020, and the entire content of the base application is incorporated by reference. Technical Field

[0003] The disclosure described in this specification relates to a battery module including a plurality of battery packs. Background Art

[0004] As shown in Patent Document 1, a power supply system including a battery and a battery monitoring system is known. The battery monitoring system includes a plurality of battery monitoring devices and a battery ECU. The plurality of battery monitoring devices communicate wirelessly with the battery ECU.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-61303 Summary of the Invention

[0008] In the power supply system described in Patent Document 1, when wireless signals are output from a plurality of battery monitoring devices and a battery ECU to a metal enclosure, the wireless signals are repeatedly reflected on the inner wall surface of the enclosure. Thus, if n is an integer of 2 or more, higher-order electromagnetic waves including frequencies that are n times the frequencies included in the wireless signals are generated in the enclosure. Standing waves formed by the superposition of a plurality of electromagnetic waves with different frequencies are generated in the enclosure. Places where the electromagnetic waves are likely to be enhanced and places where they are likely to be weakened are generated in the enclosure. As a result, wireless communication between the plurality of battery monitoring devices and the battery ECU may be hindered.

[0009] An object of the present disclosure is to provide a battery module that suppresses hindrance to wireless communication.

[0010] A battery module according to one aspect of the present disclosure includes:

[0011] A plurality of battery packs, each of the plurality of battery packs includes a plurality of battery cells, a battery case, a first terminal connection portion, and a second terminal connection portion. A negative electrode terminal and a positive electrode terminal are formed on the electrode formation surface of the plurality of battery cells and are arranged separately in the lateral direction along the electrode formation surface of the metal case. In the battery case, the plurality of battery cells are accommodated in a form arranged along the electrode formation surface and in the longitudinal direction intersecting the lateral direction. The first terminal connection portion electrically connects the negative electrode terminal of one of the two battery cells arranged adjacent to each other in the longitudinal direction among the plurality of battery cells and the positive electrode terminal of the other. The second terminal connection portion is electrically connected to the positive electrode terminal of one of the two battery cells arranged adjacent to each other in the longitudinal direction among the plurality of battery cells and the negative electrode terminal of the other in the lateral direction, and is separated from the first terminal connection portion;

[0012] A plurality of individual detection portions, each of the plurality of individual detection portions individually detects the physical quantity of each of the plurality of battery packs;

[0013] A plurality of individual communication portions, each of the plurality of individual communication portions outputs the detection result of each of the plurality of individual detection portions through a wireless signal;

[0014] A monitoring portion, the monitoring portion performs wireless communication with each of the plurality of individual communication portions; and

[0015] An electromagnetic reflection housing, the electromagnetic reflection housing accommodates each of the plurality of battery packs, the plurality of individual detection portions, the plurality of individual communication portions, and the monitoring portion in an accommodation space,

[0016] An individual communication portion is provided in a waveguide path defined between the first terminal connection portion and the second terminal connection portion in the lateral direction and defined between the electrode formation surface and the opposing surface of the electromagnetic reflection housing in the height direction orthogonal to the electrode formation surface.

[0017] The shortest length of one of the lateral direction and the height direction of the waveguide path is longer than half of the wavelength of the wireless signal and shorter than an integral multiple of the wavelength. The shortest length of the other of the lateral direction and the height direction of the waveguide path is shorter than the shortest length of one of the lateral direction and the height direction of the waveguide path.

[0018] A battery module according to one aspect of the present disclosure has:

[0019] A plurality of battery packs;

[0020] A plurality of individual detection portions, each of the plurality of individual detection portions individually detects the physical quantity of each of the plurality of battery packs;

[0021] A plurality of individual communication portions, each of the plurality of individual communication portions outputs the detection result of each of the plurality of individual detection portions through a wireless signal;

[0022] A monitoring portion, the monitoring portion performs wireless communication with each of the plurality of individual communication portions;

[0023] An electromagnetic reflection housing that houses each of a plurality of battery packs, a plurality of individual detection units, a plurality of individual communication units, and a monitoring unit in a housing space; and

[0024] A plurality of individual waveguides that house each of the plurality of individual communication units in an internal waveguide path,

[0025] The shortest separation distance in a first direction orthogonal to the extending direction of the waveguide path in the inner wall surface that divides the waveguide path is longer than half of the wavelength of the radio signal and shorter than an integral multiple of the wavelength, and the shortest separation distance in a second direction orthogonal to both the extending direction and the first direction is shorter than the shortest separation distance in the first direction.

[0026] According to the present disclosure, it is possible to suppress the intrusion of electromagnetic waves (higher-order electromagnetic waves) having a frequency that is an integral multiple of the frequency included in the radio signal transmitted and received between the individual communication unit and the monitoring unit into the waveguide path. In addition, it is possible to suppress the generation of higher-order electromagnetic waves in the waveguide path.

[0027] Therefore, it is possible to suppress the standing wave formed by the coincidence of a plurality of higher-order electromagnetic waves having different frequencies in the waveguide path. It is possible to suppress the generation of a place where the electromagnetic wave is easily enhanced and a place where the electromagnetic wave is easily attenuated in the waveguide path. As a result, it is possible to suppress that the individual communication unit provided in the waveguide path hardly receives the radio signal output from the monitoring unit. Thereby, it is possible to suppress the obstruction of wireless communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram for explaining a battery module and a battery ECU.

[0029] Figure 2 It is a top view showing a battery pack.

[0030] Figure 3 It is a cross-sectional view for explaining a waveguide path of the first embodiment.

[0031] Figure 4 It is a cross-sectional view for explaining a waveguide path of the second embodiment.

[0032] Figure 5 It is a cross-sectional view for explaining a waveguide path of the third embodiment.

[0033] Figure 6 It is a cross-sectional view for explaining a waveguide path of the third embodiment.

[0034] Figure 7 It is a cross-sectional view for explaining a waveguide path of the fourth embodiment.

[0035] Figure 8 It is a cross-sectional view for explaining a modified example of the battery module.

[0036] Figure 9 It is a cross-sectional view for explaining a modified example of the battery module. Detailed implementation manners

[0037] Hereinafter, with reference to the drawings, a plurality of manners for implementing the present disclosure will be described. In each embodiment, parts corresponding to those described in the previous embodiment may be denoted by the same reference numerals, and repeated descriptions may be omitted. When only a part of the structure is described in each embodiment, the other embodiments described previously can be applied to the other parts of the structure.

[0038] Parts that are explicitly shown as combinable in each embodiment can be combined with each other. In addition, as long as the combination does not cause any hindrance, even if not explicitly shown as combinable, embodiments can be partially combined with each other, embodiments can be combined with modified examples, and modified examples can be combined with each other.

[0039] (First Embodiment)

[0040] Based on Figures 1 to 3 , the battery module of this embodiment will be described. The battery module of this embodiment is applicable to vehicles such as electric vehicles or plug-in hybrid vehicles.

[0041] Hereinafter, three directions that are orthogonal to each other will be represented as the x-direction, y-direction, and z-direction. In addition, the description of "direction" is omitted in the drawings. The x-direction corresponds to the lateral direction. The y-direction corresponds to the longitudinal direction. The z-direction corresponds to the height direction.

[0042] <On-vehicle battery>

[0043] Figure 1 The battery module 10 is shown. The battery module 10 constitutes an on-vehicle power supply. The battery module 10 functions to supply power to the electrical loads of the vehicle. Of course, an on-vehicle power supply can also be constituted by electrically connecting a plurality of battery modules 10 in series or in parallel.

[0044] The temperature of the battery module 10 is adjusted by the air supplied from a fan installed in the vehicle. Alternatively, the temperature of the battery module 10 is adjusted by a cooling liquid circulating in the vehicle interior. Thereby, excessive temperature changes of the battery module 10 can be suppressed.

[0045] As the installation location of the battery module 10, for example, the space under the front seat of the vehicle, the space under the rear seat, and the space between the rear seat and the trunk can be adopted.

[0046] <Battery module>

[0047] As Figure 1 shown, the battery module 10 has a plurality of battery packs 20, a unified monitoring unit 30, and a housing 40. The plurality of battery packs 20 and the unified monitoring unit 30 are housed in the housing space of the housing 40.

[0048] <Battery Pack>

[0049] The plurality of battery packs 20 each have a plurality of battery cells 50, a battery housing 60, a bus bar 70, and an information acquisition unit 80. The battery housing 60 houses the plurality of battery cells 50. The bus bar 70 electrically connects the plurality of battery cells 50. The information acquisition unit 80 acquires the physical quantities of the plurality of battery cells 50 and outputs them to the unified monitoring unit 30. In addition, the information acquisition unit 80 performs the equalization process described later.

[0050] The battery cell 50 is a secondary battery that generates an electromotive force through a chemical reaction. As such a secondary battery, for example, a lithium ion secondary battery can be used.

[0051] The battery cell 50 has a power generation element and a metal housing that houses the power generation element. As Figure 2 and Figure 3 shown, the metal housing is formed in a flat plate shape with a relatively thin thickness in the y direction. The metal housing has a first end face 50a and a second end face 50b arranged in the z direction, a first main face 50c and a second main face 50d arranged in the y direction, and a first side face 50e and a second side face 50f arranged in the x direction. Among the six faces included in the above metal housing, the areas of the first main face 50c and the second main face 50d are larger than the areas of the other four faces.

[0052] A negative electrode terminal 51 and a positive electrode terminal 52 are formed on the first end face 50a of the metal housing. The negative electrode terminal 51 and the positive electrode terminal 52 are arranged separately in the x direction. The negative electrode terminal 51 is located on the side of the first side face 50e. The positive electrode terminal 52 is located on the side of the second side face 50f. The first end face 50a corresponds to the electrode formation face.

[0053] <Battery Housing>

[0054] As Figure 2 and Figure 3 shown, the battery housing 60 has a support wall 61 and a peripheral wall 62. The support wall 61 is integrally connected to the peripheral wall 62. The support wall 61 and the peripheral wall 62 are each made of an insulating resin material. In addition, Figure 3 shows the cross-sectional shape of the battery pack 20 along the III-III line shown in Figure 2 .

[0055] The support wall 61 is formed in a flat shape with a relatively thin thickness in the z direction. The support wall 61 has an inner support surface 61a and an outer support surface 61b arranged separately in the z direction.

[0056] The peripheral wall 62 stands up from the inner support surface 61a in the z direction. The peripheral wall 62 extends along the edge of the inner support surface 61a and is formed in a ring shape in the circumferential direction around the z direction.

[0057] Specifically described in detail, the peripheral wall 62 has a first end wall 63 and a second end wall 64 that are arranged separately in the y direction, and a first connecting wall 65 and a second connecting wall 66 that are arranged separately in the x direction. The first end wall 63, the first connecting wall 65, the second end wall 64, and the second connecting wall 66 are sequentially connected in the circumferential direction around the z direction. Thus, the peripheral wall 62 is formed in a ring shape in the circumferential direction around the x direction. The space above the inner support surface 61a is surrounded by the peripheral wall 62. A plurality of battery cells 50 are accommodated in this accommodation space.

[0058] The second end face 50b side of each of the plurality of battery cells 50 is accommodated in the accommodation space of the battery case 60. The first end face 50a side of each of the plurality of battery cells 50 is located outside the accommodation space of the battery case 60. Therefore, the negative terminals 51 and the positive terminals 52 of each of the plurality of battery cells 50 are located outside the accommodation space of the battery case 60.

[0059] The plurality of battery cells 50 are arranged in the y direction between the first end wall 63 and the second end wall 64 of the battery case 60. Although not shown, the battery case 60 has a partition wall provided between any two adjacent battery cells 50 arranged in the y direction. Through this partition wall, the separation interval in the y direction between any two adjacent battery cells 50 arranged in the y direction is w1. This first separation interval w1 is narrower than the thickness of the battery cell 50 in the y direction.

[0060] Any two adjacent battery cells 50 arranged in the y direction are arranged such that the first main surfaces 50c face each other or the second main surfaces 50d face each other. Through this relative arrangement, the negative terminal 51 of one of the two adjacent battery cells 50 arranged in the y direction and the positive terminal 52 of the other are arranged in the y direction.

[0061] The separation interval in the y direction between the negative terminal 51 of one of any two adjacent battery cells 50 arranged in the y direction and the positive terminal 52 of the other is w2. This second separation interval w2 is of the same degree as the thickness of the battery cell 50 in the y direction or shorter than its thickness.

[0062] As Figure 2As shown, a plurality of negative terminal ends 51 and positive terminal ends 52 are arranged in an alternating columnar pattern on one side of the first connection wall 65 and the second connection wall 66 of the battery case 60, respectively. Hereinafter, for simplicity of notation, the electrode terminal group including the plurality of negative terminal ends 51 and positive terminal ends 52 arranged in a column on one side of the first connection wall 65 is denoted as the first electrode terminal group. The electrode terminal group including the plurality of negative terminal ends 51 and positive terminal ends 52 arranged in a column on one side of the second connection wall 66 is denoted as the second electrode terminal group.

[0063] The negative terminal ends 51 and positive terminal ends 52 included in the first electrode terminal group and the second electrode terminal group are electrically connected by Figure 2 and Figure 3 the bus bar 70 shown. Through this electrical connection, a plurality of battery cells 50 are electrically connected in series to form a battery stack.

[0064] Although not shown, the battery stacks included in each battery pack 20 are electrically connected in series by wires or the like. In addition, power lines are connected to the battery pack 20 at the highest potential and the battery pack 20 at the lowest potential, respectively. Additionally, the battery stacks included in each battery pack 20 may also be electrically connected in parallel.

[0065] <Bus bar>

[0066] The bus bar 70 is made of a metallic material including a conductive material such as copper or aluminum. The bus bar 70 includes two terminal conductive parts 71 integrally connected in a manner arranged along the y direction. The terminal conductive part 71 is formed in a flat plate shape with a relatively thin thickness in the z direction. The thickness of the terminal conductive part 71 is determined such that when laser welding the electrode terminal of the terminal conductive part 71 and the battery cell 50, the temperature rise due to the laser can be avoided to the extent that the performance of the battery cell 50 does not change.

[0067] The conductive extension part 72 extends from one of the two terminal conductive parts 71 included in the bus bar 70. The conductive extension part 72 extends from the terminal conductive part 71 in a manner separated from the current path between the connection part with the negative terminal end 51 of one of the two terminal conductive parts 71 and the connection part with the positive terminal end 52 of the other of the two terminal conductive parts 71. Therefore, it is difficult for current to flow in the conductive extension part 72. This conductive extension part 72 is electrically connected to the voltage sensor 90a described later.

[0068] As Figure 2 shown, a plurality of bus bars 70 are arranged separately in the y direction. The separation interval in the y direction between two adjacent bus bars 70 arranged in the y direction is w3. This third separation interval w3 is shorter than the above-mentioned second separation interval w2.

[0069] <Information acquisition part>

[0070] The information acquisition unit 80 includes: a plurality of sensors 90 that detect the physical quantities of the respective plurality of battery cells 50; a separate monitoring unit 100 into which the detection results of the plurality of sensors 90 are input; and a separate communication unit 110 that inputs and outputs wireless signals. The sensors 90 are disposed on the object to be detected. The separate monitoring unit 100 and the separate communication unit 110 are respectively mounted on the wiring board 81. As Figure 2 shown, the wiring board 81 is disposed on the first end surface 50a of the plurality of battery cells 50.

[0071] As the plurality of sensors 90, there are a voltage sensor, a temperature sensor, and a current sensor. The voltage sensor detects the output voltage of each of the plurality of battery cells 50. The temperature sensor detects the temperature of at least one of the plurality of battery cells 50. The current sensor detects the current that commonly flows through each of the plurality of battery cells 50 connected in series. The sensor 90 corresponds to a separate detection unit.

[0072] In Figure 2 and Figure 3 , only the voltage sensor 90a among the various sensors that detect the above different physical quantities is shown as a representative. The voltage sensor 90a includes a voltage detection wiring 91, a voltage detection terminal 92, a detection screw 93, and a nut 94.

[0073] The voltage detection wiring 91 is an insulated wire in which a wire is covered with an insulating coating. One end of the voltage detection wiring 91 is connected to the voltage detection terminal 92. The other end of the voltage detection wiring 91 is electrically connected to the separate monitoring unit 100 via a connector or the like mounted on the wiring board 81. In Figure 2 , in order to avoid the markings from becoming complicated, only one end side of the voltage detection wiring 91 is shown.

[0074] Through holes that open in the z direction are respectively formed in the voltage detection terminal 92 and the conductive extension portion 72. The voltage detection terminal 92 and the conductive extension portion 72 are relatively arranged in a state where the two through holes communicate with each other in the z direction. The shaft portion of the detection screw 93 passes through the two through holes, and the nut 94 is fastened to the shaft portion.

[0075] One side of the shaft portion of the head of the detection screw 93 contacts the upper surface of the voltage detection terminal 92, and the nut 94 contacts the lower surface of the conductive extension portion 72. The voltage detection terminal 92 and the conductive extension portion 72 are clamped between the head of the detection screw 93 and the nut 94. Thus, each of the plurality of voltage detection terminals 92 is individually electrically connected to each of the plurality of conductive extension portions 72.

[0076] The detection results of multiple sensors 90 are input to the individual monitoring unit 100. The individual monitoring unit 100 generates a monitoring signal that assigns an identification code for identifying the signal output from which battery pack 20 among the multiple battery packs 20 based on the detection results of the above-mentioned multiple sensors 90. This monitoring signal is input to the individual communication unit 110.

[0077] The individual communication unit 110 converts the input monitoring signal into a wireless signal. This wireless signal is output from the individual communication unit 110 to the accommodation space of the housing 40. This wireless signal is received by the unified monitoring unit 30. Wireless communication is performed between the individual communication unit 110 and the unified monitoring unit 30.

[0078] As the wireless signals respectively output from the individual communication unit 110 and the unified monitoring unit 30, radio waves with a frequency band of 3 kHz to 3 THz are used. In particular, as this wireless signal, extremely high frequency radio waves with a frequency band of 300 MHz to 3 GHz can be used.

[0079] The frequencies and wavelengths of the wireless signals respectively output from the individual communication unit 110 and the unified monitoring unit 30 are constant. The frequency (wavelength) of the wireless signal is determined according to the shape of the battery cell 50 used, etc. Hereinafter, for the sake of simplicity of notation, the frequency of the wireless signal is represented as the basic frequency f. The wavelength of the wireless signal is represented as the basic wavelength λ.

[0080] <Unified Monitoring Unit>

[0081] The unified monitoring unit 30 receives the wireless signals respectively output from the multiple battery packs 20. The unified monitoring unit 30 converts this wireless signal into a digital signal. Then, the unified monitoring unit 30 outputs this digital signal to the battery ECU 200. The unified monitoring unit 30 is equivalent to the monitoring unit.

[0082] The battery ECU 200 calculates the SOC of the battery module 10 based on the input digital signal. SOC is the abbreviation of state of charge. Then, the battery ECU 200 determines the charge and discharge of the battery module 10 based on the detected SOC and vehicle-mounted information input from other vehicle-mounted ECUs, vehicle-mounted sensors, etc.

[0083] In addition, the battery ECU 200 calculates the SOC of each of the multiple battery cells 50 included in each of the multiple battery packs 20. Then, the battery ECU 200 determines whether to perform the equalization process of the SOC of each of the multiple battery cells 50. The battery ECU 200 outputs an instruction signal based on the determination of this equalization process to the unified monitoring unit 30.

[0084] In addition, the battery ECU has at least one arithmetic processing device (CPU) and at least one memory device (MMR) as a recording medium for recording programs and data. The battery ECU is provided by a microcomputer including a recording medium readable by a computer or a processor. The recording medium is a non-transitory physical recording medium that stores programs readable by a computer or a processor non-transitorily. The recording medium can be provided by a semiconductor memory, a magnetic disk, or the like.

[0085] The unified monitoring unit 30 outputs the input instruction signal as a wireless signal to the accommodation space of the housing 40. The instruction signal includes the above-mentioned identification code. Therefore, only the individual monitoring unit 100 corresponding to the identification code included in the wireless signal among the plurality of individual monitoring units 100 receives the wireless signal.

[0086] The individual monitoring unit 100 includes switching elements for individually charging and discharging each of the plurality of battery cells 50. The individual monitoring unit 100 controls the opening and closing of the switching elements based on the input instruction signal. As a result, specific battery cells 50 among the plurality of battery cells 50 are electrically connected to each other.

[0087] Current flows from the battery cell 50 with a relatively higher SOC among the electrically connected plurality of battery cells 50 to the battery cell 50 with a lower SOC. As a result, the SOC of each of the plurality of battery cells 50 is equalized.

[0088] In addition, the SOC of each of the plurality of battery cells 50 included in one battery pack 20 can also be calculated by the individual monitoring unit 100 included in the battery pack 20. In addition, the individual monitoring unit 100 can also determine whether to perform the equalization process of the SOC of each of the plurality of battery cells 50.

[0089] <Housing>

[0090] The housing 40 includes: a frame body 120 having an opening; and a cover body 130 fixed to the frame body 120 in a form of closing the opening.

[0091] The frame body 120 has: a bottom wall 121; and a side wall 122 standing up annularly from the bottom wall 121. The bottom wall 121 is formed in a flat shape with a relatively thin thickness in the z direction. The bottom wall 121 has an inner bottom surface 121a intersecting in the z direction. The side wall 122 stands up from the inner bottom surface 121a in the z direction. The side wall 122 is formed in a ring shape in the circumferential direction around the z direction. An opening is defined at the front end side of the side wall 122.

[0092] The cover body 130 has: a top wall 131; and a flange wall 132 standing up annularly from the top wall 131. The top wall 131 is formed in a flat shape with a relatively thin thickness in the z direction. The top wall 131 has an inner top surface 131a intersecting in the z direction. The flange wall 132 stands up from the inner top surface 131a in the z direction.

[0093] The cover body 130 is arranged in the frame body 120 in a form in which the inner top surface 131a of the top wall 131 and the inner bottom surface 121a of the bottom wall 121 are separated and arranged in the z direction. The front end sides of the flange walls 132 and the front end side of the bottom wall 121 are connected to each other. Thus, a storage space of the housing 40 is formed.

[0094] In the frame body 120, a hole (not shown) is formed for communicating the storage space formed by the frame body 120 and the cover body 130 with the space outside the storage space (external space). As the uses of this hole, there are uses such as ventilation of the housing 40, extraction of power lines, extraction of signal lines, and the like.

[0095] <Wireless Communication>

[0096] As described above, in the storage space of the housing 40, wireless communication is performed between the information acquisition units 80 of the plurality of battery packs 20 and the single unified monitoring unit 30. In order to prevent the battery module 10 from becoming an electromagnetic noise source, it is necessary to suppress the leakage of the wireless signal used in this wireless communication to the outside of the storage space of the housing 40. On the contrary, in order to suppress the obstruction of this wireless communication, it is necessary to suppress the intrusion of electromagnetic noise into the storage space of the housing 40.

[0097] To solve this technical problem, the frame body 120 and the cover body 130 each include the property of reflecting electromagnetic waves. The housing 40 including the frame body 120 and the cover body 130 is equivalent to an electromagnetic reflection housing. In order to include such a property of reflecting electromagnetic waves, the frame body 120 and the cover body 130 include the materials shown as an example below.

[0098] For example, the frame body 120 and the cover body 130 include a conductive material such as metal. The frame body 120 and the cover body 130 include a resin material and a conductive material covering its surface. The frame body 120 and the cover body 130 include a resin material and a conductive material embedded therein. The frame body 120 and the cover body 130 include carbon fiber.

[0099] <Standing Wave>

[0100] Wireless signals are respectively output from the individual communication unit 110 and the unified monitoring unit 30 to the storage space formed by the frame body 120 and the cover body 130 having the property of reflecting electromagnetic waves as described above. This wireless signal is repeatedly reflected on the inner surfaces that divide the storage spaces of the frame body 120 and the cover body 130 respectively.

[0101] By repeating this reflection, multiple higher-order electromagnetic waves including frequencies that are integer multiples of the frequency (basic frequency f) of the wireless signal are generated in the storage space. The multiple higher-order electromagnetic waves with different frequencies overlap within the storage space. As a result, a standing wave is generated in the storage space. Places where the electromagnetic waves are likely to be enhanced and places where they are likely to be weakened are generated in the storage space. As a result, it may be difficult to receive a wireless signal in the storage space. In addition, the above integer multiple means two or more times.

[0102] <Waveguide path and waveguide tube>

[0103] To solve this technical problem, a waveguide path 160 is formed in each of the multiple battery packs 20 housed in the housing 40. A separate communication unit 110 is provided in the waveguide path 160. In addition, the battery module 10 has a waveguide tube 170 that houses the unified monitoring unit 30. Figure 3 The waveguide path 160 is indicated by a single-dot dash line.

[0104] <Waveguide path>

[0105] For example, as Figure 3 shown, the battery packs 20 are housed in the storage space of the housing 40 in a form where the first end faces 50a of the multiple battery cells 50 are located on the side of the cover body 130.

[0106] Due to this configuration structure, the first end faces 50a of the multiple battery cells 50 included in the battery pack 20 and the inner top surface 131a of the top wall 131 of the cover body 130 are relatively arranged in the z direction. At the same time, the bus bars 70 connected to the electrode terminals of the multiple battery cells 50 and the heads of the detection screws 93 of the voltage sensor 90a connected to the bus bars 70 are relatively arranged in the z direction with respect to the inner top surface 131a.

[0107] As described above, the first electrode terminal group is formed by arranging the multiple negative terminal 51 and positive terminal 52 in a row on the side of the first connection wall 65. The negative terminal 51 and positive terminal 52 included in the first electrode terminal group are connected to the bus bar 70. In addition, the conductive part of the voltage sensor 90a is connected to each of the multiple above-mentioned bus bars 70. In addition, although not shown in Figure 3 , a voltage detection wiring 91 including a wire is provided above the multiple bus bars 70. The bus bar 70 connecting the negative terminal 51 and positive terminal 52 included in the first electrode terminal group corresponds to the first terminal connection part. Hereinafter, the bus bar 70 will be represented as the first bus bar 73 as needed.

[0108] Similarly, a second electrode terminal group is formed by arranging a plurality of negative terminal electrodes 51 and positive terminal electrodes 52 in a column on one side of the second connection wall 66. The negative terminal electrodes 51 and positive terminal electrodes 52 included in the second electrode terminal group are connected to the bus bar 70. The conductive portion of the voltage sensor 90a is connected to each of the plurality of bus bars 70. Although not shown in Figure 3 , a voltage detection wiring 91 including a wire is disposed above the plurality of bus bars 70. The bus bar 70 that connects the negative terminal electrode 51 and the positive terminal electrode 52 included in the second electrode terminal group corresponds to the second terminal connection portion. Hereinafter, the bus bar 70 will be referred to as the second bus bar 74 as needed.

[0109] As described above, a plurality of metal members are provided on one side of the first connection wall 65 and on one side of the second connection wall 66 on the first end face 50a of each of the plurality of battery cells 50 included in the battery pack 20. Hereinafter, the wall approximately formed by the plurality of metal members provided on one side of the first connection wall 65 will be referred to as the first metal wall 140, and the wall approximately formed by the plurality of metal members provided on one side of the second connection wall 66 will be referred to as the second metal wall 150.

[0110] In Figure 2 , the first metal wall 140 and the second metal wall 150 are schematically shown by dashed lines. The first bus bar 73 is included in the first metal wall 140. The second bus bar 74 is included in the second metal wall 150.

[0111] The waveguide path 160 is formed between the first metal wall 140 and the second metal wall 150 separated in the x direction. The shape of the waveguide path 160 is defined between the first metal wall 140 and the second metal wall 150 in the x direction, and is defined between the first end face 50a of each of the plurality of battery cells 50 and the inner top face 131a of the top wall 131 in the z direction. The relative region of the inner top face 131a that faces the first end face 50a corresponds to the opposing face.

[0112] As Figure 2 shown, the plurality of battery cells 50 are arranged in the y direction. Therefore, the waveguide path 160 is formed in a shape extending in the y direction. Further, in a plane orthogonal to the y direction, the length of the waveguide path 160 in the x direction is longer than the length in the z direction.

[0113] The separation distance a1 in the x - direction between the terminal conductive parts 71 of the first bus bar 73 and the terminal conductive parts 71 of the second bus bar 74 is longer than half of the fundamental wavelength λ and shorter than an integral multiple of the fundamental wavelength λ. Additionally, the separation distance a2 in the x - direction between the terminal conductive part 71 of one of the first bus bar 73 and the second bus bar 74 and the conductive extension part 72 of the other of the first bus bar 73 and the second bus bar 74 is longer than half of the fundamental wavelength λ and shorter than an integral multiple of the fundamental wavelength λ. The separation distance a2 corresponds to the shortest length in the x - direction of the waveguide path 160. As Figure 3 shown, the length in the x - direction of the waveguide path 160 along the cross - section of the III - III line as Figure 2 shown is a2.

[0114] Furthermore, the separation distance b in the z - direction between the first end face 50a and the inner top face 131a is shorter than both the separation distances a1 and a2. The separation distance b corresponds to the shortest length in the z - direction of the waveguide path 160.

[0115] Due to this structure, higher - order electromagnetic waves including frequencies that are integer multiples of the fundamental frequency f are difficult to invade the waveguide path 160. Additionally, in the waveguide path 160, the generation of such higher - order electromagnetic waves can be suppressed.

[0116] Furthermore, as Figure 2 shown, there is a gap with a first separation interval w1 between any two adjacent battery cells 50 arranged in the y - direction. There is a gap with a second separation interval w2 between the negative terminal 51 of one of any two adjacent battery cells 50 arranged in the y - direction and the positive terminal 52 of the other of any two adjacent battery cells 50 arranged in the y - direction. There is a gap with a third separation interval w3 between two adjacent bus bars 70 arranged in the y - direction.

[0117] Additionally, as Figure 3 shown, there is a gap with a fourth separation interval w4 between the electrode terminal of the battery cell 50 and the bus bar 70. There is a gap with a fifth separation interval w5 between the bus bar 70 included in the first metal wall 140 and the second metal wall 150 respectively and the inner top face 131a of the top wall 131. Of course, there are also gaps between the multiple conductive members included in the first metal wall 140 and the second metal wall 150 respectively.

[0118] The various gaps shown above are equivalent to holes formed in the waveguide path 160. The longest length of the above - mentioned various gaps is shorter than half of the fundamental wavelength λ. Additionally, the gap between the bus bar 70 and the top wall 131 among the above - mentioned various gaps is larger than the other gaps. The fifth separation interval w5 of the gap between the bus bar 70 and the top wall 131 corresponds to the first longest separation distance and the second longest separation distance.

[0119] Additionally, strictly speaking, as Figure 2As shown, there is a gap between two busbars 70 arranged adjacent to each other in the y direction. The length of this gap in the z direction is the separation interval between the first end face 50a of the battery cell 50 and the inner top face 131a of the top wall 131. Therefore, the length of this gap in the z direction is longer than that of other gaps. However, above the two busbars 70, there is provided a voltage detection wiring 91 including a wire. Thus, this gap is cut off in the z direction. The length of this cut-off gap in the z direction is shorter than half of the fundamental wavelength λ.

[0120] <Waveguide>

[0121] As Figure 1 shown, a unified monitoring unit 30 is accommodated in the hollow of the waveguide 170. The dividing surface 170a that divides this hollow has the property of reflecting electromagnetic waves. The opening of the waveguide 170 serves to allow a wireless signal to enter the hollow of the waveguide 170 and output the wireless signal from the hollow of the waveguide 170 to the outside. The hollow of the waveguide 170 is equivalent to a common waveguide path.

[0122] This opening is formed in a substantially rectangular parallelepiped shape. In addition, the length in the long side direction of the opening is longer than half of the fundamental wavelength λ and shorter than an integral multiple of the fundamental wavelength λ. Also, of course, the length in the short side direction of the opening is shorter than the length in the long side direction. Due to this structure, it is possible to suppress the above-mentioned higher-order electromagnetic waves from entering the inside of the waveguide 170.

[0123] In addition, the shortest separation distance in the first plane direction along the opening plane that perpendicularly penetrates the opening of the waveguide 170 and is orthogonal to the opening direction is longer than half of the fundamental wavelength λ and shorter than an integral multiple of the fundamental wavelength λ. The shortest separation distance in the second plane direction along the opening plane and orthogonal to the first plane direction is shorter than the shortest separation distance in the first plane direction. Due to this structure, it is possible to suppress the generation of the above-mentioned higher-order electromagnetic waves in the hollow of the waveguide 170. The opening direction is equivalent to the extending direction. The first plane direction is equivalent to the third direction. The second plane direction is equivalent to the fourth direction.

[0124] <Effect>

[0125] As described above, in the waveguide path 160 where the length in the x direction is longer than half of the fundamental wavelength λ and shorter than an integral multiple of the fundamental wavelength λ and the length in the z direction is shorter than the length in the x direction, a separate communication unit 110 is provided.

[0126] Thus, it is possible to suppress the intrusion of high-order electromagnetic waves including integral multiples of the fundamental frequency f into the waveguide path 160. At the same time, it is possible to suppress the generation of such high-order electromagnetic waves in the waveguide path 160. By making the high-order electromagnetic waves coincide, it is possible to suppress the generation of standing waves in the waveguide path 160. It is possible to suppress the generation of places where electromagnetic waves are likely to be enhanced and places where they are likely to be weakened in the waveguide path 160. Therefore, it is possible to suppress the difficulty of the individual communication unit 110 receiving a radio signal. It is possible to suppress interference with wireless communication.

[0127] The waveguide path 160 is composed of a first metal wall 140 and a second metal wall 150 separated in the x direction, and a plurality of cores 50 and a top wall 131 separated in the z direction. In this way, the waveguide path 160 is composed of a plurality of cores 50, a first metal wall 140 and a second metal wall 150 electrically connected to the plurality of cores 50, and a housing 40 that houses the above components. Therefore, an increase in the number of components can be suppressed.

[0128] The longest length of the holes (gaps) formed in the waveguide path 160 is shorter than half of the fundamental wavelength λ. Therefore, it is possible to suppress the intrusion of high-order electromagnetic waves into the waveguide path 160 via the gaps.

[0129] In the hollow space of a waveguide tube 170 including an opening whose length in the long side direction is longer than half of the fundamental wavelength λ and shorter than an integral multiple of the fundamental wavelength λ, and whose length in the short side direction is shorter than the length in the long side direction, a unified monitoring unit 30 is housed. In addition, the length of the hollow space of the waveguide tube 170 in the first plane direction along the opening plane is longer than half of the fundamental wavelength λ and shorter than an integral multiple of the fundamental wavelength λ. The length of the hollow space of the waveguide tube 170 in the second plane direction is shorter than the length in the first plane direction.

[0130] Thus, it is possible to suppress the intrusion of high-order electromagnetic waves into the waveguide tube 170. At the same time, it is possible to suppress the generation of high-order electromagnetic waves inside the waveguide tube 170. Therefore, it is possible to suppress the difficulty of the unified monitoring unit 30 receiving a radio signal.

[0131] As described above, it is possible to suppress the difficulty of each of the individual communication unit 110 and the unified monitoring unit 30 receiving a radio signal. Therefore, it is possible to suppress interference with the wireless communication of the individual communication unit 110 and the unified monitoring unit 30.

[0132] (Second Embodiment)

[0133] In the first embodiment, for example, as Figure 3 shown, an example in which the inner top surface 131a of the top wall 131 is flat is shown. In contrast, in the present embodiment, as Figure 4 shown, a part of the inner top surface 131a of the top wall 131 protrudes toward the core 50 side.

[0134] More specifically, a protrusion 133 that locally protrudes from the inner top surface 131a in the z direction is formed in the top wall 131. The protrusion 133 extends continuously in the y direction.

[0135] In the top wall 131, two protrusions 133 are formed for each battery pack 20. One of the two protrusions 133 is separated from and opposed to the first metal wall 140 in the z direction. The other of the two protrusions 133 is separated from and opposed to the second metal wall 150 in the z direction.

[0136] Due to this structure, the separation intervals between the top wall 131 and the first metal wall 140 and between the top wall 131 and the second metal wall 150 are respectively a sixth separation interval w6 shorter than the fifth separation interval w5. As a result, the gap formed in the waveguide path 160 becomes smaller. Thus, for example, even if the separation distance in the z direction between the battery pack 20 and the cover body 130 varies due to vibration or the like, the intrusion of high-order electromagnetic waves into the waveguide path 160 can be suppressed by the expansion of the gap formed in the waveguide path 160.

[0137] In addition, the battery module 10 of the present embodiment and the battery modules 10 of the respective embodiments described below each include the same constituent elements as the battery module 10 described in the first embodiment. Therefore, the battery modules 10 of the present embodiment and the respective embodiments described below exhibit the same effects as the battery module 10 described in the first embodiment.

[0138] (Third Embodiment)

[0139] In each of the first embodiment and the second embodiment, an example is shown in which the waveguide path 160 is composed of a plurality of battery cells 50, a first metal wall 140 and a second metal wall 150 electrically connected to the plurality of battery cells 50, and a housing 40 that houses the above components. In contrast, in the present embodiment, for example, as Figure 5 and Figure 6 shown, a structure in which the battery module 10 has a separate waveguide tube 180 that houses a separate communication unit 110 in a hollow can also be adopted.

[0140] The inner wall surface 180a that divides the hollow of the separate waveguide tube 180 has the property of reflecting electromagnetic waves. The hollow of the separate waveguide tube 180 functions as the waveguide path 160.

[0141] The shortest separation distance between the inner wall surfaces 180a in the first direction along a plane orthogonal to the extending direction of the separate waveguide tube 180 is longer than half of the fundamental wavelength λ and shorter than the equal multiple. The shortest separation distance between the inner wall surfaces 180a in the second direction along this plane and orthogonal to the first direction is shorter than the shortest length between the inner wall surfaces 180a in the first direction.

[0142] The separate waveguide tube 180 has an opening 181 that connects the inside and the outside of the hollow. Figure 5 The opening 181 of the shown separate waveguide tube 180 opens in the y direction. Figure 6 The opening 181 of the shown separate waveguide tube 180 opens in the z direction.

[0143] The planar shape of the above-mentioned opening 181 is formed into a rectangular shape. The length in the long side direction of the opening 181 is longer than half of the fundamental wavelength λ and shorter than the equal multiple. Of course, the length in the short side direction of the opening 181 is shorter than the length in the long side direction.

[0144] Due to this structure, it is also possible not to determine the frequency band of the wireless signal according to the shape and arrangement of the battery cells 50 and the housing 40 included in the battery pack 20, etc. Conversely, it is also possible not to determine the shape and arrangement of the battery cells 50 and the housing 40, etc. according to the frequency band of the wireless signal. Therefore, it is possible to prevent the design of the battery pack 20 from becoming difficult.

[0145] In addition, a hole that connects the inside and the outside of the hollow can also be formed in the separate waveguide tube 180. As long as the longest length of this hole is shorter than half of the fundamental wavelength λ. Therefore, as the separate waveguide tube 180, it is also possible to use a metal mesh or the like including an opening and a hole having the above conditions. Thereby, weight reduction can be achieved.

[0146] (Fourth Embodiment)

[0147] In the third embodiment, an example in which the hollow of the separate waveguide tube 180 functions as the waveguide path 160 is shown. In contrast, in the present embodiment, the separate waveguide tube 180 and the conductive member 82 of the wiring substrate 81 function as the waveguide path 160.

[0148] Figure 7 The shown separate waveguide tube 180 is provided on the wiring substrate 81 so as to cover the mounting surface 81a of the separate communication unit 110 in the wiring substrate 81. A conductive member 82 is provided in a region of the mounting surface 81a that is arranged in the z direction with the separate waveguide tube 180.

[0149] According to this structure, the separate communication unit 110 is provided inside the separate waveguide tube 180. At the same time, the opening in the z direction of the separate waveguide tube 180 is closed by the wiring substrate 81. As a result, the waveguide path 160 is constituted by the separate waveguide tube 180 and the conductive member 82.

[0150] The length of the waveguide path 160 in the x direction is longer than half of the fundamental wavelength λ and shorter than the equal multiple. The length of the waveguide path 160 in the z direction is shorter than the length in the x direction.

[0151] In addition, a structure in which a conductive member 82 is provided on the back surface 81b of the mounting surface 81a of the wiring board 81 can also be adopted. In addition, a structure in which the conductive member 82 is not provided on the wiring board 81 can also be adopted. In the case of this modification, the waveguide path 160 is composed of a single waveguide tube 180 and a metal housing included in a plurality of battery cells 50.

[0152] (First modification example)

[0153] In each embodiment, an example in which the wiring board 81 provided with the single communication unit 110 is disposed on the first end surface 50a of the plurality of battery cells 50 is shown. However, for example, as Figure 8 and Figure 9 shown, a structure in which the wiring board 81 is disposed on the inner top surface 131a of the top wall 131 can also be adopted. In particular, as Figure 9 shown, a structure in which the single waveguide tube 180 described in the fourth embodiment is disposed on the top wall 131 in a form surrounding the wiring board 81 can also be adopted. Although not shown, a structure in which the single waveguide tube 180 described in the third embodiment is disposed on the top wall 131 can also be adopted.

[0154] (Second modification example)

[0155] In each embodiment, an example in which the wiring board 81 provided with the single communication unit 110 is disposed on the waveguide path 160 is shown. However, if the single communication unit 110 is provided in the waveguide path 160, the wiring board 81 may not be provided in the waveguide path 160. The single monitoring unit 100 may not be provided in the waveguide path 160.

[0156] (Third modification example)

[0157] In the first embodiment, an example in which the length of the waveguide path 160 in the x direction is longer than the length in the z direction is shown. However, a structure in which the length of the waveguide path 160 in the x direction is shorter than the length in the z direction can also be adopted. The length of the waveguide path 160 in the z direction is longer than half of the fundamental wavelength λ and shorter than the equal multiple. This modification example can be appropriately adopted, for example, according to the shape of the battery cells 50 included in the battery pack 20, the frequency band of the wireless signal used, and the like.

[0158] (Fourth modification example)

[0159] In each embodiment, an example is shown in which the separate communication unit 110 is provided between the plurality of battery cells 50 and the top wall 131. However, in the case where the battery module 10 has the separate waveguide 180 described so far and the separate communication unit 110 is housed in the hollow of the separate waveguide 180, the arrangement location of the separate communication unit 110 is not particularly limited. For example, a structure in which the separate waveguide 180 housing the separate communication unit 110 is provided in the battery case 60 can also be adopted.

[0160] Although the present disclosure has been described based on the embodiments, it should be understood that the present disclosure is not limited to the above-described embodiments and structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations, modes, and further combinations and modes including only a single element, more than or less than that also fall within the scope and the scope of ideas of the present disclosure.

Claims

1. A battery module, comprising: A plurality of battery packs, each of the plurality of battery packs includes: a plurality of battery cells, a battery housing, a first terminal connection portion, and a second terminal connection portion. The plurality of battery cells form a negative terminal and a positive terminal that are arranged separately in the lateral direction along the electrode formation surface on the electrode formation surface of the metal housing. In the battery housing, the plurality of battery cells are accommodated in a form arranged along the electrode formation surface and in the longitudinal direction intersecting the lateral direction. The first terminal connection portion electrically connects the negative terminal of one of the two battery cells adjacent to each other in the longitudinal direction among the plurality of battery cells and the positive terminal of the other battery cell. The second terminal connection portion is electrically connected to the positive terminal of one of the two battery cells adjacent to each other in the longitudinal direction among the plurality of battery cells and the negative terminal of the other battery cell in the lateral direction, and is separated from the first terminal connection portion; A plurality of individual detection portions that individually detect physical quantities of each of the plurality of battery packs; A plurality of individual communication portions that output detection results of each of the plurality of individual detection portions through wireless signals; A monitoring portion that performs wireless communication with each of the plurality of individual communication portions; An electromagnetic reflection housing that houses each of the plurality of battery packs, the plurality of individual detection portions, and the plurality of individual communication portions in an accommodation space; In a waveguide path defined between the first terminal connection portion and the second terminal connection portion in the lateral direction and defined between the electrode formation surface and a relative surface of a specified electromagnetic reflection housing in the height direction orthogonal to the electrode formation surface, the individual communication portion is provided; The shortest length of one of the lateral direction and the height direction of the waveguide path is longer than half of the wavelength of the wireless signal and shorter than an integral multiple of the wavelength, and the shortest length of the other of the lateral direction and the height direction of the waveguide path is shorter than the shortest length of one of the lateral direction and the height direction of the waveguide path.

2. The battery module according to claim 1, wherein: The shortest length of the lateral direction of the waveguide path is longer than half of the wavelength and shorter than an integral multiple of the wavelength, the shortest length of the height direction of the waveguide path is shorter than the shortest length of the lateral direction of the waveguide path, The first maximum separation distance between the first terminal connection portion and the relative surface and the second maximum separation distance between the second terminal connection portion and the relative surface are each shorter than half of the wavelength.

3. The battery module according to claim 2, wherein: Compared with other portions of the relative surface, the portion of the relative surface opposite to the first terminal connection portion and the second terminal connection portion in the height direction is located on the side of the battery cells in the height direction.

4. The battery module according to claim 2, wherein: The individual communication portion is provided on the side of the relative surface in the height direction in the waveguide path.

5. The battery module according to claim 2, wherein: The wiring board (81) provided with the separate communication unit is disposed between the first terminal connection portion and the second terminal connection portion in the height direction in the waveguide path and the electrode formation surface.

6. The battery module according to claim 1, wherein: The battery module has a waveguide tube, and the waveguide tube includes a common waveguide path for accommodating the monitoring unit. The shortest separation distance in the third direction orthogonal to the extension direction of the common waveguide path in the division surface for dividing the common waveguide path is longer than half of the wavelength and shorter than an integral multiple of the wavelength, and the shortest separation distance in the fourth direction orthogonal to the extension direction and the third direction is shorter than the shortest separation distance in the fourth direction.

7. The battery module according to claim 6, wherein: The waveguide tube is arranged in contact with the electromagnetic reflection housing.

8. The battery module according to any one of claims 1 to 7, wherein: The separate communication unit and the monitoring unit are arranged at different positions in the height direction.

9. The battery module according to any one of claims 1 to 7, wherein: A plurality of the separate communication units are arranged longitudinally.

10. The battery module according to claim 6, wherein: The separate communication unit is arranged at a position different from the positive terminal and the negative terminal in the lateral direction.

11. A battery module, comprising: A plurality of battery packs; A plurality of separate detection units that separately detect physical quantities of the plurality of battery packs; A plurality of separate communication units that output detection results of the plurality of separate detection units through wireless signals; A monitoring unit that performs wireless communication with the plurality of separate communication units respectively; An electromagnetic reflection housing that houses each of the plurality of battery packs, the plurality of separate detection units, the plurality of separate communication units, and the monitoring unit in an accommodation space; And A plurality of separate waveguide tubes that house each of the plurality of separate communication units in an internal waveguide path, The shortest separation distance in the first direction orthogonal to the extension direction of the waveguide path in the inner wall surface for dividing the waveguide path is longer than half of the wavelength of the wireless signal and shorter than an integral multiple of the wavelength, and the shortest separation distance in the second direction orthogonal to the extension direction and the first direction is shorter than the shortest separation distance in the first direction.

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