Electric vehicle

Abstract

To provide an electric vehicle that allows constant check of the degree of deterioration of a battery mounted therein and that cannot be altered.SOLUTION: An electric vehicle according to an aspect of the present disclosure comprises a motor for traveling, a battery that supplies power to the motor for traveling, and a deterioration meter that measures the degree of deterioration of the battery. The deterioration meter has an analog display unit that indicates the measured degree of deterioration with an indicator. The indicator is movable only in a direction in which the degree of deterioration increases. The position of the needle is held in a power-off state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to electric vehicles. [Background technology]

[0002] For example, as disclosed in Patent Document 1, a battery equipped with a fuel gauge that measures and displays the remaining battery charge is known. When an electric vehicle runs, the traction motor is driven by electricity stored in the battery. Therefore, when buying and selling a used electric vehicle, for example, it is important to know the degree of battery deterioration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-028839 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, for example, the battery disclosed in Patent Document 1 is equipped with a remaining capacity gauge, but is not equipped with a deterioration meter that measures and displays the deterioration level of the battery. Therefore, with the battery disclosed in Patent Document 1, in order to grasp the deterioration level of the battery, it is necessary to measure with a separate deterioration meter, and it is not possible to grasp the deterioration level of the battery easily. The inventor is therefore currently working on developing an electric vehicle equipped with a deterioration meter, but the degree of deterioration measured by the deterioration meter needs to be constantly verifiable and unalterable.

[0005] The present disclosure has been made in consideration of the above circumstances, and provides an electric vehicle in which the degree of deterioration of the on-board battery can be checked at all times and cannot be altered. [Means for solving the problem]

[0006] An electric vehicle according to one embodiment of the present disclosure includes: A driving motor; a battery for supplying power to the driving motor; a deterioration meter for measuring a deterioration degree of the battery, The deterioration meter has an analog display unit that indicates the deterioration degree by a measuring needle, the needle is movable only in a direction in which the degree of deterioration increases; The position of the needle is maintained in the power off state.

[0007] In the electric vehicle according to the present disclosure, the deterioration meter for measuring the deterioration level of the battery has an analog display unit that indicates the measured deterioration level with a needle. The needle of the display unit can only move in the direction in which the deterioration level increases, and the position of the needle is maintained when the power is off. Therefore, it is possible to provide an electric vehicle in which the deterioration level of the installed battery can be constantly confirmed and cannot be changed.

[0008] The display unit may be provided on an instrument panel inside the vehicle. With this configuration, the deterioration level of the battery can be constantly checked from inside the vehicle. Furthermore, the display unit may also be provided on the battery. With this configuration, the deterioration level of the battery can be confirmed even when the battery is removed from the electric vehicle.

[0009] In the display unit, the deterioration level may be indicated by a plurality of color-coded regions. With this configuration, the deterioration level of the battery can be easily grasped.

[0010] The needle may be driven only if the degree of deterioration measured this time is greater than the degree of deterioration measured last time. Effect of the Invention

[0011] The present disclosure makes it possible to provide an electric vehicle in which the degree of deterioration of the on-board battery can be constantly checked and cannot be altered. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing a configuration of an electric vehicle according to a first embodiment. [Diagram 2] 4 is a flowchart showing a method for controlling a deterioration meter according to the first embodiment. [Diagram 3] 6 is a graph showing changes in battery temperature and resistance value with respect to the elapsed time after driving has ended. [Figure 4] FIG. 13 is a graph of a map showing the relationship between resistance value and deterioration degree at each temperature. [Diagram 5] 10 is a flowchart showing a method for controlling a deterioration meter according to a second embodiment. [Figure 6] FIG. 13 is a graph of a map showing the relationship between section capacity and deterioration level for each amount of SOC change. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, specific embodiments of the present disclosure will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiments. In addition, the following description and drawings are appropriately simplified for clarity of explanation.

[0014] (First embodiment) <Electric vehicle configuration> First, the configuration of the electric vehicle according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the configuration of the electric vehicle according to the first embodiment.

[0015] 1, the electric vehicle according to this embodiment includes a traction motor 10, a main battery 20, and a deterioration meter 30. Here, the deterioration meter 30 includes a deterioration meter control unit 31, a needle drive unit 32, and a display unit 33.

[0016] The traction motor 10 is a motor that drives wheels (not shown) of the electric vehicle with power supplied from a main battery 20 to cause the electric vehicle to run.

[0017] The main battery 20 is connected to the driving motor, and supplies charged electric power to the driving motor 10. The voltage of the main battery 20 is, for example, 200V. As shown in FIG. 1, the main battery 20 is provided with a temperature sensor TS that measures the temperature of the main battery 20, and a resistance sensor RS that measures the internal resistance of the main battery 20 (hereinafter simply referred to as "resistance").

[0018] 1 shows only the main battery 20 that supplies power to the driving motor 10, and omits the sub-battery and the electrical equipment (auxiliary devices) that operate with the power supplied from the sub-battery. The voltage of the sub-battery is, for example, 12 V. The auxiliary devices include, for example, headlights, blinkers, air conditioners, car navigation systems, audio equipment, and various control units.

[0019] As shown in Fig. 1, the electric vehicle according to this embodiment includes a deterioration meter 30. In the electric vehicle according to this embodiment, a deterioration meter control unit 31 acquires the temperature of the main battery 20 from a temperature sensor TS, and acquires the resistance of the main battery 20 from a resistance sensor RS. The deterioration meter control unit 31 then determines the degree of deterioration by referring to a map showing the relationship between the resistance and the deterioration degree of the main battery 20 at the measured temperature.

[0020] Here, the deterioration meter control unit 31 outputs the obtained deterioration degree to the needle drive unit 32 only when the obtained deterioration degree is greater than the previously obtained deterioration degree. The needle drive unit 32 drives the needle ND of the display unit 33 based on the degree of deterioration obtained from the deterioration meter control unit 31.

[0021] 1, the deterioration meter control unit 31 includes a calculation unit such as a CPU (Central Processing Unit) and a memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory) in which various programs and various data including the above-mentioned maps are stored. In other words, the deterioration meter control unit 31 has a function as a computer and controls the needle drive unit 32 based on the above-mentioned various programs and the like.

[0022] 1 can be configured, as hardware, by the above-mentioned CPU, memory, and other circuits. Also, as software, the deterioration meter control unit 31 can be realized by a program stored in memory, etc. In other words, the deterioration meter control unit 31 can be realized in various forms by hardware, software, or a combination of both.

[0023] The deterioration meter control unit 31 stores in advance a map showing the relationship between the resistance and the deterioration degree at various assumed temperatures of the main battery 20. In the example shown in FIG. 1, a memory (not shown) that stores a map showing the relationship between resistance and deterioration degree is provided inside the deterioration meter control unit 31, but it may also be provided outside the deterioration meter control unit 31.

[0024] As shown in Fig. 1, the display unit 33 is an analog display unit that indicates the measured deterioration degree with a needle ND. As described above, the needle ND is driven by a needle driving unit 32 such as a motor. In the example shown in Fig. 1, the needle ND rotates clockwise to indicate the deterioration degree. In addition, in the display unit 33, for example, a needle ND provided parallel to the vertical direction may be moved linearly in the horizontal direction to indicate the deterioration degree.

[0025] Here, the hand ND of the display unit 33 can only move in a direction in which the deterioration level increases, and cannot move in a direction in which the deterioration level decreases. In the example shown in FIG. 1, the hand ND of the display unit 33 can only move in a clockwise direction in which the deterioration level increases. Therefore, it is possible to suppress modification of moving the hand ND in a direction in which the deterioration level decreases. Furthermore, it is also possible to configure the hand ND so that, for example, when attempting to move the hand ND in a direction in which the deterioration level decreases, the hand ND is damaged, or a stopper (not shown) that prevents the hand ND from moving in a direction in which the deterioration level decreases is damaged. With such a configuration, it is possible to further suppress modification of moving the hand ND in a direction in which the deterioration level decreases.

[0026] The position of the needle ND is maintained when the electric vehicle is powered off. Therefore, the deterioration level of the main battery 20 can be constantly checked on the display unit 33 regardless of whether the electric vehicle is powered on or off. That is, in the electric vehicle according to this embodiment, the deterioration level of the mounted main battery 20 can be constantly confirmed by the display unit 33 and cannot be changed.

[0027] The display unit 33 is provided, for example, on an instrument panel inside the vehicle. With this configuration, the deterioration degree of the main battery 20 can be constantly checked from inside the vehicle. Furthermore, the display unit 33 may be provided in the main battery 20 itself. With this configuration, the deterioration degree of the main battery 20 can be checked even when the main battery 20 is removed from the electric vehicle.

[0028] 1, the deterioration level indicated by the needle ND is shown in multiple color-coded regions, a blue region B, a yellow region Y, and a red region R. For example, the blue region B, the yellow region Y, and the red region R represent "good," "slightly deteriorated," and "needs replacement," respectively. With this configuration, the deterioration level of the main battery 20 can be easily grasped.

[0029] As described above, in the electric vehicle according to this embodiment, the deterioration meter 30 that measures the deterioration level of the main battery 20 has an analog display unit 33 that indicates the measured deterioration level with a needle ND. The needle ND of the display unit 33 can only move in a direction that increases the deterioration level, and the position of the needle ND is maintained in a power-off state. Therefore, in the electric vehicle according to this embodiment, the deterioration level of the installed main battery 20 can be checked at any time, but cannot be changed.

[0030] <Control method of the deterioration meter> Next, a method for controlling a deterioration meter according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the method for controlling a deterioration meter according to the first embodiment. First, as shown in FIG. 2, after driving of the driving motor 10 is turned off and driving is terminated (step ST11), the deterioration meter control unit 31 measures the temperature and resistance of the main battery 20 (step ST12).

[0031] 2, if the temperature and resistance of the main battery 20 have not been measured the predetermined N times (NO in step ST13), the deterioration meter control unit 31 repeats the measurement of the temperature and resistance, i.e., step ST12. On the other hand, if the temperature and resistance have been measured the predetermined N times (YES in step ST13), the deterioration meter control unit 31 determines whether the most recent N measured values ​​are stable (step ST14).

[0032] Here, Fig. 3 is a graph showing the change in battery temperature and resistance value with respect to the elapsed time after the end of driving. The horizontal axis of Fig. 3 indicates the elapsed time (hours) after the end of driving, the left vertical axis of Fig. 3 indicates the outside air temperature and the temperature of the main battery 20 (°C), and the right vertical axis indicates the normalized resistance value. The normalized resistance value is the ratio R / R0_Tr of the measured resistance value R to the initial resistance value R0_Tr of the main battery 20 at a predetermined reference temperature Tr.

[0033] In the example shown in Fig. 3, the temperature and resistance of the main battery 20 are measured every hour after driving ends. In the example shown in Fig. 3, the predetermined number of times N=3, and if the difference between the measured values ​​before and after two consecutive measurements is within a predetermined reference range, it is determined that the measured value is stable. In the example shown in Fig. 3, the object of determination as to whether the measured value is stable is the resistance of the main battery 20, but it may also be the temperature of the main battery 20, or both the resistance and the temperature.

[0034] 3, the temperature of the main battery 20, which rose during driving, decreases to approach the outside air temperature as time passes after driving ends. The resistance of the main battery 20 increases as the temperature of the main battery 20 decreases, and when the temperature of the main battery 20 stabilizes, the resistance of the main battery 20 also stabilizes.

[0035] 2 and 3, if the N measured values ​​are not stable (NO in step ST14), the deterioration meter control unit 31 measures the temperature and resistance again. That is, the process returns to step ST12. On the other hand, if the N measured values ​​are stable (YES in step ST14), the deterioration meter control unit 31 refers to a map showing the relationship between the resistance at the measured temperature and the deterioration degree, and determines the deterioration degree (step ST15).

[0036] Step ST15 will be described with reference to Fig. 3 and Fig. 4. Fig. 4 is a graph of a map showing the relationship between the resistance value and the deterioration degree at each temperature. The horizontal axis of Fig. 4 indicates the normalized resistance value, and the vertical axis of Fig. 4 indicates the deterioration degree (%). The normalized resistance value indicates the ratio between the resistance value R of the main battery 20 at each temperature T and the initial resistance value R0_T.

[0037] The deterioration calculation control unit 31 has a map showing the relationship between the resistance value and the degree of deterioration at various temperatures. In FIG. 4, only the maps at temperatures T1 and T2 (<T1) are shown as representatives. Here, the normalized resistance value for temperature T1 indicates the ratio R / R0_T1 of the resistance value R of the main battery 20 at temperature T1 to the initial resistance value R0_T1. The normalized resistance value for temperature T2 indicates the ratio R / R0_T2 of the resistance value R of the main battery 20 at temperature T2 to the initial resistance value R0_T2.

[0038] In the example shown in FIG. 3, the degree of deterioration is obtained using the average value Ra of the three resistance values enclosed by the broken line and the average value Ta of the temperatures. Here, if the average value Ta of the temperatures enclosed by the broken line in FIG. 3 is T1, the degree of deterioration is obtained using the map at temperature T1 shown in FIG. 4. Specifically, the degree of deterioration corresponding to the normalized resistance value Ra / R0_T1 is obtained. On the other hand, if the average value Ta of the temperatures enclosed by the broken line in FIG. 3 is T2, the degree of deterioration is obtained using the map at temperature T2 shown in FIG. 4. Specifically, the degree of deterioration corresponding to the normalized resistance value Ra / R0_T2 is obtained.

[0039] Next, as shown in FIG. 2, if the degree of deterioration obtained this time is greater than the degree of deterioration obtained last time (YES in step ST16), the needle ND of the display unit 33 in the deterioration meter 30 is driven (step ST17), and the control of the deterioration meter 30 is terminated. Specifically, the deterioration calculation control unit 31 outputs the degree of deterioration obtained this time to the needle driving unit 32, and the needle driving unit 32 drives the needle ND of the display unit 33 based on the degree of deterioration acquired from the deterioration calculation control unit 31. On the other hand, if the degree of deterioration obtained this time is less than or equal to the degree of deterioration obtained last time (NO in step ST16), step ST17 is not performed, and the control of the deterioration meter 30 is terminated as it is. This is because the current degree of deterioration will not be smaller than the past degree of deterioration.

[0040] (Second Embodiment) The configuration of the electric vehicle according to the second embodiment is also substantially the same as that of the electric vehicle according to the first embodiment shown in FIG. 1. Here, as shown in FIG. 1, in the electric vehicle according to the first embodiment, the deterioration calculation control unit 31 obtains the degree of deterioration based on the temperature and resistance of the main battery 20. In contrast, in the electric vehicle according to this embodiment, the deterioration meter control unit 31 determines the deterioration level based on the SOC change amount and the section capacity for each run of the main battery 20. That is, the deterioration meter control unit 31 stores in advance a map showing the relationship between the section capacity and the deterioration level for various expected SOC changes.

[0041] <Control method of the deterioration meter> Next, a method for controlling a deterioration meter according to a second embodiment will be described with reference to Fig. 5. Fig. 5 is a flowchart showing a method for controlling a deterioration meter according to a second embodiment. First, as shown in FIG. 5, after driving of the driving motor 10 is turned on to start driving (step ST21), the degradation meter control unit 31 measures the current and the amount of change in SOC during driving (step ST22).

[0042] Next, as shown in FIG. 2, after turning off the drive of the driving motor 10 and ending driving (step ST23), the deterioration meter control unit 31 refers to a map showing the relationship between the section capacity (integral value of current) at the SOC change amount during this driving and the deterioration degree, and determines the deterioration degree (step ST24).

[0043] Step ST24 will be described with reference to Fig. 6. Fig. 6 is a graph of a map showing the relationship between section capacity and deterioration level at each SOC change amount. The horizontal axis of Fig. 6 indicates section capacity (Ah), and the vertical axis of Fig. 6 indicates deterioration level (%). Section capacity is the integral value of the current (discharging current and charging current) that flows through main battery 20 during traveling, with discharging current being positive and charging current being negative.

[0044] The deterioration meter control unit 31 has a map showing the relationship between the section capacity and the deterioration level for various SOC change amounts, but Fig. 6 only shows the maps for SOC change amount=X% and Y (>X)% as representative examples. If the SOC change amount in the current drive is X%, the map for SOC change amount=X% shown in Fig. 6 is used to determine the deterioration level corresponding to the section capacity in the current drive. On the other hand, if the SOC change amount in the current drive is Y%, the map for SOC change amount=Y% shown in Fig. 6 is used to determine the deterioration level corresponding to the section capacity in the current drive.

[0045] 5, if the currently calculated deterioration degree is greater than the previously calculated deterioration degree (YES in step ST25), the needle ND of the display unit 33 in the deterioration meter 30 is driven (step ST26), and control of the deterioration meter 30 is terminated. Specifically, the deterioration meter control unit 31 outputs the currently calculated deterioration degree to the needle drive unit 32, and the needle drive unit 32 drives the needle ND of the display unit 33 based on the deterioration degree acquired from the deterioration meter control unit 31. On the other hand, if the currently calculated deterioration degree is equal to or less than the previously calculated deterioration degree (NO in step ST25), step ST26 is not performed, and control of the deterioration meter 30 is terminated. This is because the current deterioration degree cannot be smaller than the past deterioration degree. The other configurations are similar to those of the first embodiment, so detailed description will be omitted.

[0046] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit and scope of the present disclosure. For example, as shown in the first and second embodiments, the method of determining the deterioration degree in the deterioration meter 30 is not particularly limited, and various variations are possible. This disclosure will also promote the use of electric vehicles and contribute to carbon neutrality, decarbonization, and the Sustainable Development Goals (SDGs). [Explanation of symbols]

[0047] 10. Driving motor 20 Main battery 30 Deterioration meter 31 Deterioration meter control unit 32 Needle drive unit 33 Display section ND needle RS Resistance Sensor TS Temperature Sensor

Claims

1. A driving motor; a battery for supplying power to the driving motor; a deterioration meter for measuring a deterioration degree of the battery, The deterioration meter has an analog display unit that indicates the measured deterioration degree with a needle, the needle is movable only in a direction in which the degree of deterioration increases; The position of the needle is maintained in a power-off state. Electric car.

2. The display unit is provided on an instrument panel inside the vehicle. The electric vehicle of claim 1 .

3. The display unit is also provided on the battery. The electric vehicle according to claim 2.

4. In the display unit, the deterioration degree is shown in a plurality of color-coded regions. The electric vehicle according to any one of claims 1 to 3.

5. The needle is driven only when the degree of deterioration measured this time is greater than the degree of deterioration measured last time. The electric vehicle according to any one of claims 1 to 3.

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