JP6859872B2 - Monitoring device - Google Patents

Description

The disclosure of this specification relates to a battery cell monitoring device.

As shown in Patent Document 1, a battery module including a cell group in which a plurality of cell cells are arranged side by side and a battery wiring module attached to the cell group is known.

The battery wiring module includes a plurality of bus bars, a flexible printed circuit board, and a connector. The flexible printed circuit board includes a plurality of voltage detection lines for detecting the voltage of each cell. These plurality of voltage detection lines connect the bus bar and the connector. The connector is connected to the battery ECU.

Japanese Unexamined Patent Publication No. 2017-27831

As described above, the battery wiring module outputs the voltage of each of the cells of the cell group to the battery ECU via the bus bar, the voltage detection line, and the connector. Therefore, if noise is input to, for example, a voltage detection line, the voltage detection accuracy may decrease. On the other hand, it is conceivable to separately prepare a shield member for noise countermeasures to suppress noise input. However, in this case, there arises a problem of increasing the number of parts.

Therefore, it is an object of the disclosure of the present specification to provide a monitoring device in which an increase in the number of parts is suppressed.

One of the disclosures is a monitoring unit (10) that monitors the voltage of a plurality of battery cells (220) connected in series.
A wiring unit (30) that electrically connects the monitoring unit and the electrode terminals (221,222) of the battery cell, and
It has a noise removing element (12,60) provided in at least one of a monitoring unit and a wiring unit, and has.
The wiring portion has a flexible substrate (40) having flexibility and a wiring pattern (50) formed on the flexible substrate.
The wiring pattern includes a connection pattern (51) for connecting the battery cell and the monitoring unit, and a solid pattern (52) for noise suppression.
The flexible substrate has a connection region (44) on which a connection pattern is formed and a solid region (45) on which a solid pattern is formed.
The flexible substrate is bendable with respect to at least one of the connecting area and the monitoring section so that at least one of the connecting area and the monitoring section is covered by the solid area.

According to this, it is not necessary to prepare a shield member separately. Therefore, the increase in the number of parts is suppressed.

The elements described in the claims and the means for solving the problem are each marked with parentheses. The reference numerals in parentheses are for simply indicating the correspondence with each component described in the embodiment, and do not necessarily indicate the element itself described in the embodiment. The description of the code in parentheses does not unnecessarily narrow the scope of claims.

It is a circuit diagram of a battery pack. It is a top view which shows the battery stack. It is a top view which shows the monitoring apparatus of 1st Embodiment. It is a top view which shows the state which the monitoring device is provided in the battery stack. It is a top view which shows the state which the monitoring device is connected to the battery stack. It is sectional drawing which follows the VI-VI line of FIG. FIG. 5 is a cross-sectional view taken along the line VII-VII of FIG. It is a top view which shows the monitoring apparatus of 2nd Embodiment. It is a top view which shows the state which the monitoring device is connected to the battery stack. It is a top view which shows the monitoring apparatus of 3rd Embodiment. It is a top view which shows the state which the monitoring device is connected to the battery stack. It is a top view which shows the monitoring apparatus of 4th Embodiment. It is a top view which shows the state which the monitoring device is connected to the battery stack. It is a top view which shows the modification of the monitoring apparatus. It is sectional drawing for demonstrating the modification of the solid pattern. It is sectional drawing for demonstrating the separation distance between a solid pattern and a noise removing element. It is a top view which shows the modification of the battery module. It is a top view which shows the state which the monitoring device is provided in the battery module shown in FIG. It is a top view which shows the state which the monitoring device is connected to the battery module shown in FIG.

Hereinafter, embodiments will be described with reference to the drawings.

(First Embodiment)
The battery pack according to this embodiment will be described with reference to FIGS. 1 to 7. The battery pack of this embodiment is applied to a hybrid vehicle. In the following, the three directions orthogonal to each other are referred to as a horizontal direction, a vertical direction, and a height direction. In the present embodiment, the lateral direction is along the advancing / retreating direction of the hybrid vehicle. The vertical direction is along the left-right direction of the hybrid vehicle. The height direction is along the top and bottom directions of the hybrid vehicle.

(Overview of battery pack)
The battery pack 400 functions to supply electric power to the electric load of the hybrid vehicle. This electrical load includes a motor generator that acts as a power source and power source. For example, when the motor generator powers up, the battery pack 400 discharges to supply power to the motor generator. When the motor generator generates electricity, the battery pack 400 charges the generated power generated by the power generation.

The battery pack 400 has a battery ECU 300. The battery ECU 300 is electrically connected to various ECUs (vehicle-mounted ECUs) mounted on the hybrid vehicle. The battery ECU 300 and the vehicle-mounted ECU transmit and receive signals to each other to coordinately control the hybrid vehicle.

The battery pack 400 has a battery module 200. As shown in FIG. 2, the battery module 200 has a battery stack 210 in which a plurality of battery cells 220 are electrically and mechanically connected in series.

The battery pack 400 has a monitoring device 100. The monitoring device 100 monitors the voltage of each battery cell 220 constituting the battery stack 210.

As shown above, the battery pack 400 includes a monitoring device 100, a battery module 200, and a battery ECU 300. In addition to this, the battery pack 400 may have a blower fan for cooling the battery module 200. The drive of the blower fan is controlled by the battery ECU 300.

The battery pack 400 is provided in, for example, an arrangement space under a seat of a hybrid vehicle. This arrangement space is wider under the rear seats than under the front seats. The battery pack 400 of the present embodiment is provided in the arrangement space under the rear seat. Hereinafter, the battery module 200 and the monitoring device 100 will be described.

(Overview of battery module)
As shown in FIG. 2, the battery module 200 has a battery stack 210. Although not shown, the battery module 200 has a housing for accommodating the battery stack 210. This housing is made of die-cast aluminum. The housing has a box shape that opens in the height direction and has a bottom. The opening of the housing is covered with a lid. A distribution channel through which wind flows is configured inside the housing. At least one of the housing and the lid is configured with a communication hole for communicating the external atmosphere and the communication path.

The battery stack 210 has a plurality of battery cells 220. These plurality of battery cells 220 are arranged in the vertical direction. The plurality of battery cells 220 are electrically and mechanically connected in series. Therefore, the output voltage of the battery module 200 is the sum of the output voltages of the plurality of battery cells 220.

(Overview of monitoring device)
As shown in FIG. 1, the monitoring device 100 includes a monitoring unit 10 that monitors the voltage of each of the plurality of battery cells 220, and a wiring unit 30 that electrically connects the monitoring unit 10 and each of the plurality of battery cells 220. .. Each of the monitoring unit 10 and the wiring unit 30 is provided in the battery module 200. Specifically, the monitoring unit 10 is provided above or to the side of the battery stack 210. The wiring portion 30 is provided above the battery stack 210. The wiring unit 30 connects at least one of the positive electrode terminal 221 and the negative electrode terminal 222 of the plurality of battery cells 220 included in the battery stack 210 to the monitoring unit 10.

(Battery stack configuration)
Next, the battery stack 210 will be described in detail with reference to FIG. As described above, the battery stack 210 has a plurality of battery cells 220. The battery cell 220 has a quadrangular prism shape. Therefore, the battery cell 220 has six surfaces.

The battery cell 220 has an upper end surface 220a facing in the height direction. Although not shown, the battery cell 220 has a lower end surface facing in the height direction. The battery cell 220 has a first side surface 220c and a second side surface 220d facing in the lateral direction. The battery cell 220 has a first main surface 220e and a second main surface 220f facing in the vertical direction. Of these six surfaces, the first main surface 220e and the second main surface 220f have a larger area than the other surfaces.

The battery cell 220 is a secondary battery. Specifically, the battery cell 220 is a lithium ion battery. Lithium-ion batteries generate an electromotive voltage through a chemical reaction. A current flows through the battery cell 220 due to the generation of the electromotive voltage. As a result, the battery cell 220 generates heat. The battery cell 220 expands.

As described above, the first main surface 220e and the second main surface 220f of the battery cell 220 have a larger area than the other surfaces. Therefore, in the battery cell 220, the first main surface 220e and the second main surface 220f are likely to expand. As a result, the battery cell 220 expands in the vertical direction. That is, the battery cell 220 expands in the direction in which the plurality of battery cells 220 are lined up.

The battery stack 210 has a restraint (not shown). By this restraint, the plurality of battery cells 220 are mechanically connected in series in the vertical direction. Further, this restraint suppresses the increase in the physique of the battery stack 210 due to the expansion of each of the plurality of battery cells 220. A gap is formed between the adjacent battery cells 220. The heat dissipation of each battery cell 220 is promoted by passing air through this gap.

A positive electrode terminal 221 and a negative electrode terminal 222 are formed on the upper end surface 220a of the battery cell 220. The positive electrode terminal 221 and the negative electrode terminal 222 are arranged in the horizontal direction. The positive electrode terminal 221 is located on the first side surface 220c side. The negative electrode terminal 222 is located on the second side surface 220d side. The positive electrode terminal 221 and the negative electrode terminal 222 correspond to the electrode terminals.

As shown in FIG. 2, two battery cells 220 arranged adjacent to each other face each other with the first main surface 220e facing each other and the second main surface 220f facing each other. As a result, one positive electrode terminal 221 and the other negative electrode terminal 222 of the two battery cells 220 arranged adjacent to each other are vertically arranged. As a result, in the battery stack 210, the positive electrode terminals 221 and the negative electrode terminals 222 are alternately arranged in the vertical direction.

In the battery stack 210, the first electrode terminal group 211 in which the positive electrode terminals 221 and the negative electrode terminals 222 are alternately arranged in the vertical direction, and the second electrode terminal group 212 in which the negative electrode terminals 222 and the positive electrode terminals 221 are alternately arranged in the vertical direction. , Is configured. In the first electrode terminal group 211 and the second electrode terminal group 212, the arrangement of the positive electrode terminal 221 and the negative electrode terminal 222 is opposite. The first electrode terminal group 211 and the second electrode terminal group 212 are arranged in the horizontal direction.

Of the electrode terminals constituting the first electrode terminal group 211 and the second electrode terminal group 212 described above, one positive electrode terminal 221 and one negative electrode terminal 222 that are vertically aligned and adjacent to each other extend vertically in series terminal 223. It is electrically connected via. As a result, the plurality of battery cells 220 constituting the battery stack 210 are electrically connected in series.

The battery stack 210 of this embodiment has 16 battery cells 220. These 16 battery cells 220 are connected in series. Therefore, the total number of the positive electrode terminals 221 and the negative electrode terminals 222 is 32. As shown in FIGS. 1 and 2, these 32 electrode terminals are assigned numbers that increase in number from the lowest potential to the highest potential. As the number of numbers (No) shown in the figure increases, the potential (voltage) of the electrode terminal increases.

In FIG. 2, No. The negative electrode terminal 222 of the battery cell 220 described as 0 has a ground potential (minimum potential). No. The positive electrode terminal 221 of the battery cell 220 described as 31 has a potential (maximum potential) that is the sum of the outputs of the battery cells 220. The lowest potential negative electrode terminal 222 and the highest potential positive electrode terminal 221 are connected to an electric load. As a result, the potential difference between the lowest potential and the highest potential is output to the electric load as the output voltage of the battery module 200.

(Configuration of monitoring device)
Next, the monitoring device 100 will be described in detail with reference to FIGS. 1 to 7. As described above, the monitoring device 100 has a monitoring unit 10 and a wiring unit 30. In FIGS. 3 to 5, the solid pattern 52, the connection pattern 53, and the ground pattern 54 are hatched in order to clarify the configuration.

As shown in FIG. 1, the monitoring unit 10 includes a printed circuit board 11, a first electronic element 12, and a monitoring IC chip 13. The first electronic element 12 and the monitoring IC chip 13 are mounted on the printed circuit board 11. The first electronic element 12 and the monitoring IC chip 13 are electrically connected to each other via the board wiring 14 of the printed circuit board 11.

The wiring unit 30 is connected to the printed circuit board 11 of the monitoring unit 10. As a result, the battery stack 210 and the monitoring unit 10 are electrically connected via the wiring unit 30. The printed circuit board 11 of the monitoring unit 10 is provided with a connector (not shown). A wire 301 is connected to this connector. This wire 301 is connected to the battery ECU 300. As a result, the monitoring unit 10 is connected to the battery ECU 300.

As shown in FIG. 3, the wiring portion 30 has a flexible substrate 40 having flexibility, a wiring pattern 50 formed on the flexible substrate 40, and a second electronic element 60 formed on the wiring pattern 50. As shown in FIG. 6, each of the wiring pattern 50 and the second electronic element 60 is formed on the surface 40a of the flexible substrate 40. The front surface 40a and the back surface 40b of the flexible substrate 40 are each covered with a coating resin 70. The coating resin 70 covers at least a part of the second electronic element 60 and the wiring pattern 50. The flexible substrate 40 corresponds to a flexible substrate. Note that FIG. 6 schematically shows the formation position of the second cut 40d, which will be described later, by a broken line.

The flexible substrate 40 is made of a material that is more flexible than the printed circuit board 11. The flexible substrate 40 is thinner than the printed circuit board 11. Therefore, the flexible substrate 40 is bendable. That is, the flexible substrate 40 can be elastically deformed.

The flexible substrate 40 has a rectangular shape extending in the vertical direction. The monitoring unit 10 is connected to one end of the flexible substrate 40 in the vertical direction. As shown in FIG. 4, the flexible substrate 40 is provided between the first electrode terminal group 211 and the second electrode terminal group 212 of the battery stack 210.

The first cut 40c is formed on the flexible substrate 40. In FIGS. 3 and 4, the first cut 40c is shown by a alternate long and short dash line. The first cut 40c penetrates the front surface 40a and the back surface 40b of the flexible substrate 40. The first cut 40c is formed in the center of the flexible substrate 40 without interruption from one end side to the other end along the vertical direction. Further, the first cut 40c is formed without interruption along the lateral direction on one end side. As a result, the first cut 40c forms a T shape. The flexible substrate 40 is divided into a first electrode terminal group 211 side and a second electrode terminal group 212 side by the first cut 40c.

The first cut 40c is cut open at the other end of the flexible substrate 40. However, one end of the flexible substrate 40 is not cut open in the first cut 40c. Therefore, the portion of the flexible substrate 40 on the side of the first electrode terminal group 211 and the portion on the side of the second electrode terminal group 212 are mechanically connected via the portion on one end side.

In the following, for the sake of simplicity, the portion of the flexible substrate 40 on the side of the first electrode terminal group 211 is referred to as the first FPC 41. The portion of the flexible substrate 40 on the 212 side of the second electrode terminal group is referred to as the second FPC 42. A portion of the flexible substrate 40 on one end side is referred to as a third FPC43.

The third FPC43 is located between the first FPC41 and the second FPC42 in the lateral direction. In FIGS. 3 to 5, in order to clarify the boundary between the third FPC43 and the first FPC41 and the boundary between the third FPC43 and the second FPC42, each boundary is indicated by a chain double-dashed line.

Each of the first FPC 41 and the second FPC 42 has a connection region 44 in which the connection pattern 51 described later is formed, and a solid region 45 in which the solid pattern 52 is formed. As shown in FIG. 4, the connection region 44 of the first FPC 41 is located on the side of the first electrode terminal group 211 in a state where the monitoring device 100 is simply provided on the battery stack 210. The solid region 45 of the first FPC 41 is located on the center side of the battery stack 210. On the other hand, the connection region 44 of the second FPC 42 is located on the second electrode terminal group 212 side. The solid region 45 of the second FPC 42 is located on the center side of the battery stack 210. The solid region 45 of the first FPC 41 and the solid region 45 of the second FPC 42 are separated by the first cut 40c described above. Further, the solid region 45 of the first FPC 41 and the third FPC 43 are separated by the first cut 40c. The solid region 45 of the second FPC 42 and the third FPC 43 are separated by the first cut 40c.

However, the connection area 44 of the first FPC 41 and the connection area 44 of the second FPC 42 are mechanically connected via the third FPC 43. A connection pattern 53, which will be described later, is formed in the portion of the connection region 44 of the first FPC 41 and the second FPC 42 on the third FPC 43 side, and in each of the third FPC 43. A ground pattern 54, which will be described later, is also formed on the third FPC 43.

At the boundary between the connection region 44 and the solid region 45 in each of the first FPC 41 and the second FPC 42, a second cut 40d (perforation) is formed to facilitate the curvature of each of the first FPC 41 and the second FPC 42. The second cut 40d is shown by a broken line in FIGS. 3 and 4. The second cut 40d is formed along the vertical direction at the boundary between the connection region 44 and the solid region 45. The second cut 40d is composed of a plurality of intermittent notches penetrating the front surface 40a and the back surface 40b of the flexible substrate 40. Therefore, the connection region 44 and the solid region 45 are mechanically connected via a portion between the plurality of notches of the second cut 40d. The second cut 40d may be formed by alternately arranging thin portions and thick portions locally.

As shown in FIGS. 5 and 7, each of the first FPC 41 and the second FPC 42 is curved around the second cut 40d. The surface 40a of the connection region 44 and the surface 40a of the solid region 45 face each other in the height direction. By doing so, the solid region 45 and the connection region 44 are arranged so as to face each other. In this facing arrangement, as shown in FIG. 7, the separation distance L2 between the solid pattern 52 and the second electronic element 60 is set to be longer than the thickness L1 of the flexible substrate 40. The separation distance L2 is set so that capacitive coupling between the solid pattern 52 and the second electronic element 60 can be avoided. As is clearly shown in FIG. 7, the separation distance between the solid pattern 52 in the solid area 45 and the connection pattern 51 in the connection area 44 is longer than the separation distance L2. In FIG. 7, the formation position of the second cut 40d is schematically shown by a broken line.

The wiring pattern 50 includes a connection pattern 51 that electrically connects the monitoring unit 10 and the electrode terminals of the battery cell 220, and a solid pattern 52 for noise suppression that suppresses the input of noise to the electronic element. Further, the wiring pattern 50 includes a connection pattern 53 that connects a plurality of solid patterns 52, and a ground pattern 54 that connects the solid pattern 52 to the monitoring unit 10.

As shown in FIGS. 1 and 4, one end of the connection pattern 51 is connected to the electrode terminal, and the other end is connected to the monitoring unit 10. The wiring pattern 50 has 17 connection patterns 51. A connection terminal 51a is connected to one end of each of these 17 connection patterns 51. A second electronic element 60 is provided on the center side or the end side of each of the connection patterns 51.

Eight of the 17 connection patterns 51 are formed in the connection region 44 of the first FPC 41. These eight connection patterns 51 are No. 1, No. 5, No. 9, No. 13, No17, No. 21, No. 25, No. It corresponds to the positive electrode terminal 221 of 29. Eight connection terminals 51a are provided on the side along the vertical direction of the first electrode terminal group 211 side of the connection region 44 of the first FPC 41.

Further, the remaining nine connection patterns 51 are formed in the connection region 44 of the second FPC 42. These nine connection patterns 51 are No. Negative electrode terminal 222 of 0, No. 3, No. 7, No. 11, No. 15, No19, No. 23, No. 27, No. It corresponds to the positive electrode terminal 221 of 31. Nine connection terminals 51a are provided on the side along the vertical direction of the second electrode terminal group 212 side of the connection region 44 of the second FPC 42.

As shown in FIG. 4, the 17 connection terminals 51a have No. It is electrically connected to the negative electrode terminal 222 of 0 and all the positive electrode terminals 221. As a result, the wiring unit 30 and the battery stack 210 have an electrical connection configuration as shown in FIG. In addition, these 17 connection terminals 51a are No. It may be electrically connected to the positive electrode terminal 221 of 31 and all the negative electrode terminals 222. Furthermore, the 17 connection terminals 51a have No. Negative electrode terminal 222 of 0, No. It may be electrically connected to the positive electrode terminal 221 of 31 and all the series terminals 223. Regardless of the connection configuration, the electrical connection configuration shown in FIG. 1 is obtained.

As shown in FIGS. 3 and 4, a solid pattern 52 is formed in the solid region 45 of each of the first FPC 41 and the second FPC 42. The solid pattern 52 is formed over the entire surface 40a of the solid region 45. However, a connecting terminal 80 for connecting the solid region 45 to the battery stack 210 is connected to the surface 40a of the solid region 45. A solid pattern 52 is formed on the surface 40a of the solid region 45 in a manner of avoiding a connection portion with the connecting terminal 80 on the surface 40a of the solid region 45. As a result, the connecting terminal 80 and the solid pattern 52 are electrically disconnected. The connecting surface of the connecting terminal 80 and the forming surface of the solid pattern 52 do not have to be the same. For example, the connecting terminal 80 may be connected to the front surface 40a, and the solid pattern 52 may be formed on the back surface 40b. However, in order to avoid capacitive coupling between the connecting terminal 80 and the solid pattern 52, it is preferable that the connecting terminal 80 and the solid pattern 52 are not opposed to each other.

The four connecting terminals 80 are connected to the solid region 45. Two of the four connecting terminals 80 are connected to the solid region 45 of the first FPC 41. These two connecting terminals 80 are connected to the first cut 40c side in the solid region 45 of the first FPC 41. These two connecting terminals 80 are No. 10, No. It corresponds to 26 negative electrode terminals 222.

Further, the remaining two connecting terminals 80 are connected to the solid region 45 of the second FPC 42. These two connecting terminals 80 are connected to the first cut 40c side in the solid region 45 of the second FPC 42. These two connecting terminals 80 are No. 4, No. It corresponds to 20 negative electrode terminals 222.

As shown in FIG. 4, the monitoring device 100 is mounted on the battery stack 210 in such a manner that the back surface 40b of the flexible substrate 40 faces the upper end surface 220a of the battery cell 220. After that, as shown in FIG. 5, the first FPC 41 is curved so that the surface 40a of the connection region 44 and the surface 40a of the solid region 45 face each other in the height direction around the second cut 40d of the first FPC 41. In this state, the two connecting terminals 80 connected to the solid region 45 of the first FPC 41 are No. 10, No. It is fixed to the negative electrode terminal 222 of 26 by welding or the like. As a result, the curved state of the flexible substrate 40 is maintained. As a result, the solid region 45 of the first FPC 41 and the connection region 44 are arranged so as to face each other. The solid region 45 covers the connection region 44.

Similarly, the second FPC 42 is curved so that the surface 40a of the connection region 44 and the surface 40a of the solid region 45 face each other in the height direction with the second cut 40d of the second FPC 42 as the center. In this state, the two connecting terminals 80 connected to the solid region 45 of the second FPC 42 are No. 5, No. It is fixed to the negative electrode terminal 222 of 21 by welding or the like. As a result, the solid region 45 of the second FPC 42 and the connection region 44 are arranged to face each other. The solid region 45 covers the connection region 44.

As shown in FIGS. 3 and 4, a connection pattern 53 is formed in each of the connection area 44 and the third FPC 43 of the first FPC 41 and the second FPC 42, respectively. The connection pattern 53 formed on the first FPC 41 extends from the solid pattern 52 of the first FPC 41 to the third FPC 43 via the second cut 40d of the first FPC 41. Similarly, the connection pattern 53 formed on the second FPC 42 extends from the solid pattern 52 of the second FPC 42 to the third FPC 43 via the second cut 40d of the second FPC 42. The connection pattern 53 formed on the third FPC 43 connects the connection pattern 53 of the first FPC 41 and the connection pattern 53 of the second FPC 42. As described above, the solid pattern 52 of the first FPC 41 and the solid pattern 52 of the second FPC 42 are electrically connected via the connection pattern 53.

The vertical length (width) of the portion formed in the second cut 40d in the connection pattern 53 is longer than the vertical length of the intermittent notch constituting the second cut 40d. Therefore, the connection pattern 53 is formed at a portion between the plurality of notches of the second cut 40d. The vertical direction corresponds to the formation direction.

A ground pattern 54 is formed on the third FPC 43. One end of the ground pattern 54 is electrically connected to the connection pattern 53, and the other end is electrically connected to the monitoring unit 10. As described above, the solid pattern 52 of each of the first FPC 41 and the second FPC 42 is electrically connected to the monitoring unit 10 via the connection pattern 53 and the ground pattern 54. As the name implies, the ground pattern 54 is connected to the ground potential in the monitoring unit 10. As a result, the solid pattern 52 of each of the first FPC 41 and the second FPC 42 has a ground potential.

As described above, the connection area 44 is covered with the solid area 45. As a result, the connection pattern 51 and the second electronic element 60 formed in the connection region 44 are each shielded by the solid pattern 52. In FIG. 1, in order to show that the connection pattern 51 and the second electronic element 60 are each shielded by the solid pattern 52, the connection pattern 51 and the second electronic element 60 are shown surrounded by the solid pattern 52 shown by the broken line. There is.

The second electronic element 60 has a fuse 61 and an inductor 62 as shown in FIG. Further, the monitoring unit 10 has a Zener diode 15, a parallel capacitor 16, and a resistor 17 as the first electronic element 12. The second electronic element 60 and the first electronic element 12 correspond to noise removing elements.

In the following, for the sake of simplicity, the wiring composed of the connection pattern 51 connecting the adjacent battery cells 220 connected in series and the board wiring 14 will be referred to as a voltage detection wiring. The same number of voltage detection wires as the electrode terminals are formed.

A fuse 61, an inductor 62, and a resistor 17 are provided for each of the voltage detection lines. A fuse 61, an inductor 62, and a resistor 17 are connected in series from the battery cell 220 to the monitoring IC chip 13.

The Zener diode 15 and the parallel capacitor 16 are each connected in parallel between two adjacent voltage detection lines. Specifically, a Zener diode 15 and a parallel capacitor 16 are connected between the inductor 62 and the resistor 17 in the voltage detection line. The anode electrode of the Zener diode 15 is connected to the low potential side. The cathode electrode of the Zener diode 15 is connected to the high potential side. The Zener diode 15 and the parallel capacitor 16 are mounted on the printed circuit board 11.

The Zener diode 15 has a structure in which a short-circuit failure (short-circuit failure) occurs when an overvoltage is applied from the battery module 200. Specifically, the Zener diode 15 has a structure in which a PN junction type IC chip is directly sandwiched by a pair of reeds. As a result, unlike the configuration in which the IC chip and the reed are connected via the wire, it is possible to prevent the wire from being broken by the application of an overvoltage, thereby causing the Zener diode 15 to openly fail.

The fuse 61 is configured to be blown by a large current flowing through the voltage detection wiring when the Zener diode 15 is short-circuited due to an overvoltage. The rated current of the fuse 61 is set based on a large current flowing through the voltage detection wiring when the Zener diode 15 is short-circuited due to an overvoltage.

Further, the RC circuit is composed of the above-mentioned resistor 17 and the parallel capacitor 16. The RC circuit and the inductor 62 function as a filter that removes noise during voltage detection. Further, the resistor 17 constituting the RC circuit functions as a current limiting resistor during the equalization process described later.

Although not shown, the monitoring IC chip 13 includes a microcomputer and switches corresponding to each of the plurality of battery cells 220. This switch controls the connection between the two voltage detection lines. Therefore, the opening / closing control of this switch controls the charging / discharging of the battery cell 220 electrically connected to the corresponding voltage detection line.

The performance and characteristics of each battery cell 220 differ from each other due to product variation. Therefore, when charging and discharging are repeated, the charging state (SOC) of each battery cell 220 becomes different. SOC is an abbreviation for state of charge. This SOC correlates with the electromotive voltage of the battery cell 220.

By its nature, the battery cell 220 must suppress the occurrence of over-discharging and over-charging. Over-discharging and over-charging are, in other words, extreme drops and spikes in SOC. The variation in SOC of each battery cell 220 means that the degree of over-discharging and over-charging of each battery cell 220 also varies. Therefore, in order to accurately control the SOC of the battery stack 210 so as not to be over-discharged and over-charged, it is necessary to equalize the SOCs of the plurality of battery cells 220 constituting the battery stack 210. In other words, the SOC of each of the plurality of battery cells 220 needs to match the SOC of the battery stack 210, which is the arithmetic mean of these.

In response to such a request, the microcomputer of the monitoring IC chip 13 detects and monitors the output voltage (electromotive voltage) of each of the plurality of battery cells 220. This output voltage is input to the battery ECU 300.

The battery ECU 300 stores the correlation between the SOC and the electromotive voltage. The battery ECU 300 detects the SOC of each of the plurality of battery cells 220 based on the input output voltage (electromotive voltage) and the stored correlation. The battery ECU 300 determines the SOC equalization processing of the plurality of battery cells 220 based on the detected SOC. Then, the battery ECU 300 outputs an instruction for equalization processing based on the determination to the microcomputer of the monitoring IC chip 13. The microcomputer controls the opening and closing of the switches corresponding to each of the plurality of battery cells 220 based on the instruction of the equalization process. As a result, the equalization process is carried out.

The battery ECU 300 also detects the charging state of the battery stack 210 based on the input voltage and the like. The battery ECU 300 outputs the detected charging state of the battery stack 210 to the vehicle-mounted ECU. The in-vehicle ECU outputs a command signal to the battery ECU 300 based on the charging state, vehicle information such as the amount of depression of the accelerator pedal and the opening degree of the throttle valve input from various sensors mounted on the vehicle, and the ignition switch. The battery ECU 300 controls the connection between the battery pack 400 and the electric load based on this command signal.

Although not shown, a system main relay is provided between the battery stack 210 and the battery pack 400. This system main relay controls the electrical connection between the battery stack 210 and the battery pack 400 by generating a magnetic field. The battery ECU 300 controls the connection between the battery pack 400 and the electric load by controlling the generation of the magnetic field of the system main relay.

The magnetic field generated by this system main relay tries to pass through the monitoring device 100. However, the fact that the magnetic field is input to the connection pattern 51 and the second electronic element 60 is suppressed by the solid pattern 52.

(Action effect)
Next, the operation and effect of the monitoring device 100 of the battery pack 400 will be described. By bending the flexible substrate 40 as described above, the surface 40a of the connection region 44 and the surface 40a of the solid region 45 face each other in the height direction. As a result, the connection pattern 51 formed in the connection region 44 and the second electronic element 60 are each shielded by the solid pattern 52 formed in the solid region 45. Therefore, it is not necessary to prepare a shield member separately. The increase in the number of parts is suppressed.

The thickness of the flexible substrate 40 is reduced to ensure flexibility. Therefore, for example, when the solid pattern 52 is formed on the back surface 40b of the flexible substrate 40, the solid pattern 52 and the second electronic element 60, and the solid pattern 52 and the connection pattern 51 may be capacitively coupled. However, as described above, the separation distance L2 between the solid pattern 52 and the second electronic element 60 is made longer than the thickness L1 of the flexible substrate 40. This suppresses the occurrence of capacitive coupling with the solid pattern 52. Needless to say, when the flexible substrate 40 has a thickness that does not cause capacitive coupling while ensuring flexibility, a solid pattern 52 may be formed on the back surface 40b of the flexible substrate 40.

At the boundary between the connection region 44 and the solid region 45 in each of the first FPC 41 and the second FPC 42, a second cut 40d is formed to facilitate the curvature of each of the first FPC 41 and the second FPC 42. This facilitates the bending of the flexible substrate 40.

The solid pattern 52 of the first FPC 41 and the solid pattern 52 of the second FPC 42 are electrically connected via the connection pattern 53. The connection pattern 53 is connected to the ground potential of the monitoring unit 10 via the ground pattern 54. As a result, each of the plurality of solid patterns 52 can be set to the ground potential.

The vertical width of the portion formed in the second cut 40d in the connection pattern 53 is longer than the vertical length of the intermittent notch constituting the second cut 40d. According to this, the connection pattern 53 is always formed at the portion between the plurality of notches of the second cut 40d. Therefore, it is possible to prevent the second cut 40d from causing an electrical connection failure between the connection pattern 53 and the solid pattern 52.

The flexible substrate 40 is divided into a first electrode terminal group 211 side (first FPC41) and a second electrode terminal group 212 side (second FPC42) by a first cut 40c. However, the first FPC 41 and the second FPC 42 are mechanically connected via the third FPC 43. According to this, as compared with the configuration in which the first FPC 41 and the second FPC 42 are separate bodies, it is possible to prevent the monitoring device 100 from being complicatedly connected to the battery stack 210.

(Second Embodiment)
Next, the second embodiment will be described with reference to FIGS. 8 and 9. The monitoring devices of each of the following embodiments have much in common with those of the above-described embodiments. Therefore, in the following, the explanation of the common part will be omitted, and the different parts will be mainly explained. Further, in the following, the same reference numerals are given to the same elements as those shown in the above-described embodiment.

In the first embodiment, an example is shown in which the solid patterns 52 of the first FPC 41 and the second FPC 42 are connected to the monitoring unit 10 via the connection pattern 53 and the ground pattern 54. On the other hand, in the present embodiment, the solid patterns 52 of the first FPC 41 and the second FPC 42 are connected to the battery stack 210 via the connection pattern 53 and the relay pattern 55.

As shown in FIGS. 8 and 9, the connection area 44 of the second FPC 42 has a No. A connection pattern 51 corresponding to the negative electrode terminal 222 of 0 is formed. That is, a connection pattern 51 corresponding to the negative electrode terminal 222 of the ground potential is formed in the connection region 44 of the second FPC 42. In other words, a connection pattern 51 corresponding to the ground potential is formed in the connection region 44 of the second FPC 42.

In the present embodiment, the second FPC 42 is formed with a relay pattern 55 that electrically connects the connection pattern 51 and the solid pattern 52 corresponding to the ground potential. As shown in FIG. 8, the relay pattern 55 is formed in the connection region 44 and the solid region 45 of the second FPC 42. The relay pattern 55 extends from the solid pattern 52 to the connection pattern 51 corresponding to the ground potential via the second cut 40d of the second FPC 42. Also in this embodiment, the solid pattern 52 of the first FPC 41 and the solid pattern 52 of the second FPC 42 are electrically connected via the connection pattern 53.

With the above electrical connection configuration, each of the plurality of solid patterns 52 can be set to the ground potential. Further, the increase in the number of connection terminals of the monitoring unit 10 is suppressed.

The vertical length (width) of the portion formed in the second cut 40d in the relay pattern 55 is longer than the vertical length of the intermittent notch constituting the second cut 40d. According to this, the relay pattern 55 is always formed at the portion between the plurality of notches of the second cut 40d. Therefore, it is possible to prevent the second cut 40d from causing an electrical connection failure between the connection pattern 51 and the solid pattern 52.

The monitoring device 100 according to the present embodiment includes components equivalent to those of the monitoring device 100 described in the first embodiment. Therefore, it goes without saying that the same effect is achieved.

(Third Embodiment)
Next, the third embodiment will be described with reference to FIGS. 10 and 11. In the first embodiment, No. 4, No. An example is shown in which the connecting terminal 80 corresponding to the negative electrode terminal 222 of 20 is connected to the solid region 45 of the second FPC 42. On the other hand, in the present embodiment, No. 0, No. The connecting terminal 80 corresponding to the negative electrode terminal 222 of 20 is connected to the solid region 45 of the second FPC 42. And No. The connecting terminal 80 corresponding to the negative electrode terminal 222 of 0 is electrically connected to the solid pattern 52 of the second FPC 42. This connecting terminal 80 is No. It is mechanically and electrically connected to the negative electrode terminal 222 of 0. Further, also in the present embodiment, the solid pattern 52 of the first FPC 41 and the solid pattern 52 of the second FPC 42 are electrically connected via the connection pattern 53.

With the above electrical connection configuration, each of the plurality of solid patterns 52 can be set to the ground potential in the same manner as in the second embodiment. Further, the increase in the number of connection terminals of the monitoring unit 10 is suppressed.

Needless to say, the monitoring device 100 according to the present embodiment also has the same effect as the monitoring device 100 described in the first embodiment.

(Fourth Embodiment)
Next, the fourth embodiment will be described with reference to FIGS. 12 and 13. In the first embodiment, the connection pattern 51 and the second electronic element 60 are shielded by the solid pattern 52 by covering the connection region 44 with the solid region 45. On the other hand, in the present embodiment, the monitoring unit 10 is covered with the solid region 45, so that the monitoring IC chip 13, the first electronic element 12, and the substrate wiring 14 are shielded by the solid pattern 52.

In the first embodiment, an example is shown in which the first FPC 41 and the second FPC 42 each have a connection region 44 and a solid region 45, respectively. On the other hand, in the present embodiment, the first FPC 41 and the second FPC 42 each have a connection area 44, and the third FPC 43 has a solid area 45.

The solid region 45 is located on the opposite side of the third FPC 43 from the connection end with the monitoring unit 10. The solid region 45 is partitioned by a first cut 40c formed in the vertical direction shown by the alternate long and short dash line in FIG. 12 and a second cut 40d formed in the horizontal direction shown by the broken line in FIG. The solid region 45 is divided into a first FPC 41 and a second FPC 42 by a first cut 40c.

As shown in FIG. 13, the third FPC 43 is curved so that the surface of the monitoring unit 10 and the surface 40a of the solid region 45 face each other in the height direction around the second cut 40d of the third FPC 43. In this state, the third FPC 43 is fixed to the printed circuit board 11 of the monitoring unit 10 by adhesive, welding, or the like. At this time, the solid pattern 52 is connected to the ground potential of the monitoring unit 10. As a result, the solid region 45 and the monitoring unit 10 are arranged to face each other, and the monitoring unit 10 is shielded by the solid pattern 52. In the present embodiment, the layout of the board wiring 14 is determined so that the board wiring 14 provided with the first electronic element 12 is located between the second cut 40d and the monitoring IC chip 13. Therefore, due to the curvature of the third FPC 43, the monitoring IC chip 13, the first electronic element 12, and the substrate wiring 14 are shielded by the solid pattern 52.

Needless to say, the monitoring device 100 according to this embodiment also has the same effect as the monitoring device 100 described in the first embodiment.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure can be variously modified and implemented without being limited to the above-described embodiments and within a range that does not deviate from the gist of the present disclosure. Is.

(First modification)
In the first embodiment, the second embodiment, and the third embodiment, an example is shown in which the solid pattern 52 of the first FPC 41 and the solid pattern 52 of the second FPC 42 are electrically connected via the connection pattern 53. However, it is not necessary to electrically connect the solid pattern 52 of the first FPC 41 and the solid pattern 52 of the second FPC 42. For example, by adopting the configuration shown in FIG. 14, the solid pattern 52 of the first FPC 41 and the solid pattern 52 of the second FPC 42 can each have a ground potential.

In the modified example shown in FIG. 14, the ground pattern 54 is formed in the connection region 44 of the first FPC 41. The ground pattern 54 electrically connects the solid pattern 52 of the first FPC 41 and the monitoring unit 10. Further, a relay pattern 55 is formed in the connection area 44 of the second FPC 42. The relay pattern 55 electrically connects the connection pattern 51 corresponding to the ground potential and the solid pattern 52 of the second FPC 42 in the same manner as in the second embodiment. As a result, the solid pattern 52 of each of the first FPC 41 and the second FPC 42 can be set to the ground potential.

The vertical width of the portion formed in the second cut 40d in the ground pattern 54 is longer than the vertical length of the intermittent notch constituting the second cut 40d. According to this, the ground pattern 54 is always formed at the portion between the plurality of notches of the second cut 40d. Therefore, it is possible to prevent the second cut 40d from causing an electrical connection failure between the ground pattern 54 and the solid pattern 52.

(Second modification)
In the first embodiment, as shown in FIG. 6, an example is shown in which the connection pattern 51 and the solid pattern 52 are each formed on the surface 40a of the flexible substrate 40. However, for example, as shown in FIG. 15, a configuration in which the connection pattern 51 is formed on the front surface 40a of the flexible substrate 40 and the solid pattern 52 is formed on the back surface 40b of the flexible substrate 40 can be adopted.

According to this, as shown in FIG. 16, the separation distance L3 between the solid pattern 52 and the second electronic element 60 can always be made longer than the thickness L1 of the flexible substrate 40. This suppresses the occurrence of capacitive coupling between the second electronic element 60 and the solid pattern 52. As is clearly shown in FIG. 16, the separation distance between the solid pattern 52 in the solid area 45 and the connection pattern 51 in the connection area 44 is longer than the separation distance L3.

(Third variant)
In this embodiment, an example is shown in which the battery module 200 has one battery stack 210. However, the battery module 200 may have a plurality of battery stacks 210. In this case, a storage space corresponding to each battery stack 210 is configured in the housing of the battery module 200. These plurality of storage spaces are provided side by side in the horizontal direction.

For example, FIGS. 17 to 19 show a mode in which battery cells 220 of two battery stacks 210 are connected in series. The two battery stacks 210 shown in FIG. 17 have the same number of even number of battery cells 220. The negative electrode terminal 222 of the battery cell 220 located on one end side of the two battery stacks 210 and the positive electrode terminal 221 of the battery cell 220 located on the other end side of the two battery stacks 210 are lateral to each other. It is electrically connected via a series terminal 224 extending in the direction. As a result, the positive electrode terminal 221 of the battery cell 220 located on the other end side of one of the two battery stacks 210 has the highest potential, and the negative electrode terminal 222 of the battery cell 220 located on the other end side of the other has the lowest potential. The positive electrode terminal 221 having the highest potential and the negative electrode terminal 222 having the lowest potential are arranged side by side in the horizontal direction. In FIG. 17, the positive electrode terminal 221 having the highest potential and the negative electrode terminal 222 having the lowest potential are shown by broken lines.

Even in such a form, as shown in FIGS. 18 and 19, for example, by using the monitoring device 100 described in the first embodiment for each battery stack 210, the solid pattern 52 of each monitoring device 100 is connected to the ground potential. can do. The two battery stacks 210 may be electrically connected by a wire or the like instead of the series terminal 224.

(Other variants)
In each embodiment, an example in which the battery pack 400 is applied to a hybrid vehicle is shown. However, the battery pack 400 can also be applied to, for example, plug-in hybrid vehicles and electric vehicles.

In each embodiment, an example is shown in which one of the connection area 44 and the monitoring unit 10 is shielded by the solid pattern 52. Although not shown, both the connection area 44 and the monitoring unit 10 may be shielded by the solid pattern 52. As a result, the connection pattern 51, the second electronic element 60, the monitoring IC chip 13, the first electronic element 12, and the substrate wiring 14 may each be shielded by the solid pattern 52.

In each embodiment, an example is shown in which the first FPC 41 and the second FPC 42 are mechanically connected via the third FPC 43. However, the first FPC 41, the second FPC 42, and the third FPC 43 do not have to be mechanically connected as long as the electrical connection of the ground potential of the solid pattern 52 is secured. The third FPC 43 may be omitted as long as at least one of the connection area 44 and the monitoring unit 10 can be shielded by the solid pattern 52.

In each embodiment, an example is shown in which the connecting terminal 80 is mechanically connected to the battery cell 220 by directly connecting the connecting terminal 80 to the electrode terminal of the battery cell 220. However, the connecting terminal 80 can also adopt a configuration that is indirectly connected to the battery cell 220 by being connected to the restraint and the housing described in the first embodiment and the connecting terminal 51a.

10 ... Monitoring unit, 12 ... Electronic element, 30 ... Wiring unit, 40 ... Flexible substrate, 40a ... Front surface, 40b ... Back surface, 40c ... 1st cut, 40d ... 2nd cut, 41 ... 1st FPC, 42 ... 2nd FPC, 43 ... 3rd FPC, 44 ... connection area, 45 ... solid area, 50 ... wiring pattern, 51 ... connection pattern, 52 ... solid pattern, 53 ... connection pattern, 54 ... ground pattern, 55 ... relay pattern, 60 ... electronic element, 80 ... Connection terminal, 210 ... Battery stack, 211 ... First electrode terminal group, 212 ... Second electrode terminal group, 220 ... Battery cell, 221 ... Positive terminal, 222 ... Negative terminal

Claims (9)

A monitoring unit (10) that monitors the voltage of a plurality of battery cells (220) connected in series, and
A wiring unit (30) that electrically connects the monitoring unit and the electrode terminals (221,222) of the battery cell, and
It has a noise removing element (12, 60) provided in at least one of the monitoring unit and the wiring unit.
The wiring portion has a flexible substrate (40) having flexibility and a wiring pattern (50) formed on the flexible substrate.
The wiring pattern includes a connection pattern (51) for connecting the battery cell and the monitoring unit, and a solid pattern (52) for noise suppression.
The flexible substrate has a connection region (44) in which the connection pattern is formed and a solid region (45) in which the solid pattern is formed.
The flexible substrate is a monitoring device that is bendable with respect to at least one of the connection region and the monitoring unit so that at least one of the connection region and the monitoring unit is covered by the solid region. The monitoring device according to claim 1, further comprising a connecting terminal (80) that holds a curved state of the flexible substrate by being mechanically connected to the battery cell. The monitoring device according to claim 2, wherein the connecting terminal bends the flexible substrate so that the distance between the noise removing element and the solid pattern is longer than the thickness of the flexible substrate. The monitoring device according to claim 2 or 3, wherein the connecting terminal is connected to the solid region. The monitoring device according to claim 4, wherein the connecting terminal also has an electrical connection between the solid pattern and the electrode terminal. The monitoring device according to any one of claims 1 to 5, wherein an intermittent cut (40d) is formed at the boundary between the connection region and the solid region of the flexible substrate. A ground pattern (54) for electrically connecting the monitoring unit and the solid pattern is formed at the boundary between the connection area and the solid area.
The monitoring device according to claim 6, wherein the width of the cut in the formation direction of the portion formed at the boundary between the connection region and the solid region in the ground pattern is longer than one intermittently arranged cut. A relay pattern (55) for electrically connecting the connection pattern and the solid pattern is formed at the boundary between the connection region and the solid region.
The sixth or seventh aspect of the relay pattern, wherein the width of the portion formed at the boundary between the connection region and the solid region in the relay pattern is longer than one intermittently arranged cut. Monitoring device. The wiring pattern has a plurality of the solid patterns and has a plurality of solid patterns.
The monitoring device according to any one of claims 1 to 8, wherein the wiring pattern has a connection pattern (53) for electrically connecting a plurality of the solid patterns in addition to the connection pattern and the solid pattern.

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