Display devices for electric vehicles

Abstract

This technology provides a way to display the remaining battery capacity using the vehicle's existing metering system in an electric vehicle, which is based on a vehicle equipped with an internal combustion engine but has had its power source changed from an internal combustion engine to an electric motor. [Solution] The display device for the electric vehicle is based on a vehicle equipped with a meter device that receives voltage commands and displays information related to the remaining fuel level, and the power source of the vehicle is changed from an internal combustion engine to an electric motor driven by electrical energy stored in a battery. The electric vehicle is equipped with a control device that acquires the remaining capacity of the battery, and a conversion device that converts the remaining capacity of the battery received from the control device into a voltage command corresponding to the display related to the remaining fuel level and outputs it to the meter device.

Description

Technical Field

[0001] The present disclosure relates to a display device for an electric vehicle that uses an electric motor as a driving power device.

Background Art

[0002] Patent Document 1 discloses a technique related to an icon display device that displays the charge state level of a battery using icons between full and empty.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is conceivable to create an electric vehicle by changing the power source of a vehicle from an internal combustion engine to an electric motor based on a vehicle equipped with an internal combustion engine that uses fuel such as gasoline. In such an electric vehicle, when considering displaying the remaining capacity of the battery using the technique of Patent Document 1, it is necessary to replace or retrofit the existing meter device of the base vehicle with a dedicated meter device.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a technique capable of displaying the remaining capacity of a battery using an existing meter device of a vehicle in an electric vehicle in which the power source is changed from an internal combustion engine to an electric motor based on a vehicle equipped with an internal combustion engine.

Means for Solving the Problems

[0006] This disclosure provides a display device for an electric vehicle in which the power source of a vehicle equipped with a meter device that receives a voltage command and displays a value related to the remaining fuel level has been changed from an internal combustion engine to an electric motor driven by electrical energy stored in a battery, in order to solve the above problems, and comprises a control device that acquires the remaining capacity of the battery, and a conversion device that converts the remaining capacity of the battery received from the control device into a voltage command corresponding to a display related to the remaining fuel level and outputs it to the meter device. [Effects of the Invention]

[0007] According to the electric vehicle display device of this disclosure, a meter device that displays information related to the remaining fuel level can be used as a meter device that displays information related to the remaining battery capacity. This makes it possible to display information related to the remaining battery capacity using the vehicle's existing meter device in an electric vehicle that is based on a vehicle equipped with an internal combustion engine but has had its power source changed from an internal combustion engine to an electric motor. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows the configuration of the display device for an electric vehicle according to this embodiment. [Figure 2] This figure shows the relationship between the voltage command and the SOC (State of Control). [Figure 3] This flowchart shows an example of a routine performed by the electric vehicle of this embodiment. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described below. However, when the number of elements, quantities, amounts, ranges, etc., are mentioned in the embodiments described below, this disclosure is not limited to the number mentioned unless it is specifically stated or clearly defined in principle. Furthermore, structures, steps, etc., described in the embodiments described below are not necessarily essential to this disclosure unless they are specifically stated or clearly defined in principle.

[0010] Embodiment. 1. Configuration of the meter display system of the electric vehicle according to the embodiment

[0011] The electric vehicle according to this embodiment is a vehicle based on a vehicle equipped with an internal combustion engine that uses gasoline or other fuel for propulsion, but in which the power source of the base vehicle has been changed from an internal combustion engine to an electric motor. The electric vehicle is equipped with an electric motor, a battery, and an inverter. The electric motor is the power unit for driving. The battery stores the electrical energy that drives the electric motor. In other words, the electric vehicle is a battery electric vehicle (BEV) that runs on the electrical energy stored in the battery. The inverter converts the DC power input from the battery during acceleration into power to drive the electric motor. The inverter also converts the regenerative power input from the electric motor during deceleration into DC power and charges the battery.

[0012] Figure 1 shows the configuration of the display device for an electric vehicle according to this embodiment. The display device for the electric vehicle comprises a meter display system consisting of a meter device 10, a converter 20, and a control ECU 30.

[0013] The meter unit 10 is an existing component that was present in the base vehicle equipped with an internal combustion engine, and it is a component that displays vehicle speed, engine speed, warning lights, lights, etc. The meter unit 10 includes a fuel lamp 12 that lights up when refueling is needed, and a fuel gauge 14 for displaying the remaining fuel level. The meter unit 10 receives a voltage command corresponding to the remaining fuel level and displays the remaining fuel level on the fuel gauge 14. The fuel gauge 14 displays the remaining fuel level by a pointer that moves between "F" indicating a full tank and "E" indicating an empty tank. The meter unit 10 also lights up the fuel lamp 12 when it receives a voltage command indicating that the remaining fuel level has decreased to a predetermined level requiring refueling.

[0014] In this configuration, the meter unit 10 does not have an SOC gauge that displays the remaining battery capacity (hereinafter also referred to as "SOC") of the electric vehicle, nor a power supply lamp that indicates when power needs to be supplied to the battery. On the other hand, vehicles converted to electric vehicles do not require a fuel gauge display. Therefore, in this embodiment, the electric vehicle uses the fuel supply lamp 12 and the remaining fuel gauge 14 of the meter unit 10 as a power supply lamp and SOC gauge, respectively.

[0015] The control ECU 30 is a control device that acquires the State of Charge (SOC) of the battery of an electric vehicle. The control ECU 30 may be configured as, for example, the BEVECU, which is the ECU of the electric vehicle, or it may be implemented within the battery ECU. The control ECU 30 receives signals from various sensors, including signals from the battery's voltage sensor, current sensor, and temperature sensor. The control ECU 30 processes these signals and estimates the battery's SOC. Alternatively, the control ECU 30 receives a signal from an SOC sensor that detects the battery's SOC and detects the battery's SOC. The control ECU 30 transmits the acquired SOC to the conversion box 20 via a CAN signal.

[0016] The conversion box 20 functions as a conversion device that converts the CAN signal of the SOC received from the control ECU 30 into a voltage command to control the illumination state of the fuel lamp 12 of the meter device 10 and a voltage command to control the display of the remaining fuel gauge 14. The conversion box 20 is equipped with a CAN transceiver for receiving the CAN signal from the control ECU 30 and a control circuit that processes the received CAN signal to perform voltage conversion and voltage output.

[0017] The conversion box 20 calculates a voltage command to output to the remaining charge gauge 14 according to the battery's State of Charge (SOC). Figure 2 shows the relationship between the voltage value of the voltage command and the SOC. As shown in Figure 2, the voltage characteristics of the remaining charge gauge 14 of the meter device 10 are such that when the voltage command is 4.5V it points to "F" indicating full charge, when the voltage command is 0.3V it points to "E" indicating empty charge, and when the voltage command is 2.5V it points to half the full charge. Therefore, the conversion box 20 calculates a voltage command according to the characteristics shown in Figure 2, such that when the SOC is 100%, it corresponds to the "F" position, and when the SOC is 0%, it corresponds to the "E" position.

[0018] Furthermore, the conversion box 20 calculates a voltage command to output to the fuel lamp 12 according to the battery's State of Charge (SOC). Specifically, the conversion box 20 calculates a voltage command to turn on the fuel lamp 12 when the SOC is below a predetermined threshold requiring power supply, and calculates a voltage command to turn off the fuel lamp 12 when the SOC is greater than a predetermined threshold requiring power supply.

[0019] 2. Operation of the display device of the electric vehicle according to the embodiment Figure 3 is a flowchart showing an example of a routine executed by the display device of the electric vehicle according to this embodiment. Steps 100 and 102 of this routine are performed in the control ECU 30. In step 100, the control ECU 30 estimates or detects the battery's State of Charge (SOC). Once step 100 is complete, the process proceeds to step 102. In step 102, the control ECU 30 transmits the acquired SOC to the conversion box 20 via a CAN signal. Once step 102 is complete, the process proceeds to step 110.

[0020] The processes from step 110 to 122 are executed in the conversion BOX 20. In step 110, the conversion BOX 20 receives a CAN signal from the control ECU 30. When the process of step 110 is completed, the process proceeds to step 112. In step 112, the conversion BOX 20 acquires SOC information from the CAN signal. When the process of step 110 is completed, the process proceeds to steps 114 and 120.

[0021] The processes of steps 114, 116, and 118 are arithmetic processes for controlling the lighting of the fueling lamp 12 as a substitute for the power supply lamp. In step 114, the conversion BOX 20 determines whether the SOC acquired in step 112 is 15% or less of a predetermined value. Here, 15% is an example of the threshold value of the SOC at which power supply is required. As a result, if the determination is established, it is determined that the fueling lamp 12 as a substitute for the power supply lamp is lit, and the process proceeds to step 116. In step 116, the conversion BOX 20 outputs a voltage command (for example, 15V) for lighting the fueling lamp 12 as a substitute for the power supply lamp to the meter device 10. When the process of step 116 is completed, the process proceeds to step 130.

[0022] On the other hand, in step 114, if the determination is not established, it is determined that the fueling lamp 12 as a substitute for the power supply lamp is turned off, and the process proceeds to step 118. In step 118, the conversion BOX 20 outputs a voltage command (for example, 0V) for turning off the fueling lamp 12 as a substitute for the power supply lamp to the meter device 10. When the process of step 118 is completed, the process proceeds to step 132.

[0023] Steps 120 and 122 are calculation processes for controlling the display of the remaining gauge 14, which serves as a substitute for the SOC gauge. In step 120, the conversion box 20 calculates a voltage command to display the remaining gauge 14, which serves as a substitute for the SOC gauge. Here, the conversion box 20 uses the conversion formula shown in Figure 2 to calculate the voltage command corresponding to the SOC obtained in step 112. Once the processing in step 120 is complete, the process proceeds to step 122. In step 122, the conversion box 20 outputs the voltage command calculated in step 120 to the meter device 10. Once the processing in step 122 is complete, the process proceeds to step 134.

[0024] Steps 130, 132, and 134 are performed in the meter device 10. In step 130, the meter device 10 lights up the fuel lamp 12, which serves as a substitute for the power lamp, in accordance with the voltage command (15V) input from the conversion box 20. In step 132, the meter device 10 turns off the fuel lamp 12, which serves as a substitute for the power lamp, in accordance with the voltage command (0V) input from the conversion box 20. In step 134, the meter device 10 switches the pointer of the remaining fuel gauge 14, which serves as a substitute for the SOC gauge, to the pointer position corresponding to the voltage command, in accordance with the voltage command input from the conversion box 20.

[0025] As described above, in the electric vehicle of this embodiment, the meter device 10, which includes a display related to the remaining fuel level, can be used as a meter device that displays the remaining battery capacity and the power supply lamp. This makes it possible to display the remaining battery capacity using the vehicle's existing meter device 10 in an electric vehicle that is based on a vehicle equipped with an internal combustion engine and has had its power source changed from an internal combustion engine to an electric motor. [Explanation of symbols]

[0026] 10 Meter device 12. Fuel level indicator light 14. Battery level gauge 20 Conversion Box (Conversion Device) 30 Control ECU

Claims

[Claim 1] A display device for an electric vehicle, which has a meter device that receives a voltage command and displays information related to the remaining fuel level, and whose power source has been changed from an internal combustion engine to an electric motor driven by electrical energy stored in a battery, A control device for acquiring the remaining capacity of the aforementioned battery, A conversion device that converts the remaining capacity of the battery received from the control device into a voltage command corresponding to the display related to the remaining fuel level and outputs it to the meter device, A display device for electric vehicles equipped with this feature.

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