JP2008054442A - Small-sized electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a battery from becoming overcharge in a long descending slope, in a small-sized electric vehicle loading the battery charged by the energy of a regeneration brake. <P>SOLUTION: A charger 39 initially charges the battery 29 by an external power supply 51. An external terminal 50, such as a fault diagnosis machine, inputs a battery charging capacity limit value to a battery charging capacity limit value storage 52. At a travel mode where the regeneration brake is put on immediately after termination of charging, the battery is charged in an overvoltage operation suppression mode, where the battery charging capacity limit value is set to 80% of battery full charge time so that the battery 29 will not become overcharged. The overvoltage operation suppression mode or the normal operation mode is set in a mode-setting part 54. A mode deciding part 55 selects the battery charging capacity limit value that corresponds to the operation mode. A charging amount deciding part 57 outputs a charging termination command, when the charging amount becomes not smaller than the battery charging capacity limit value and terminates charging operation by the charger 39. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a small electric vehicle, and more particularly, to a small electric vehicle provided with a control function capable of making a charged state of a battery which is a driving power source of an electric motor appropriate.

In recent years, small electric vehicles having a structure suitable for low-speed traveling have become widespread so that elderly people, people with physical disabilities, and the like can easily use them. This small electric vehicle is equipped with a battery as a power source of the electric motor, and various devices have been devised so that the electric vehicle can travel as long as possible with one battery charge. For example, Japanese Patent Application Laid-Open No. 2000-102116 proposes a small electric vehicle in which an in-vehicle battery is charged with electric power generated by a regenerative brake in order to efficiently use energy stored in the battery. In this type of small electric vehicle, the battery may be overcharged in a situation where the vehicle often travels on a downhill road. Overcharging can shorten the life of the battery or adversely affect electronic equipment that directly uses the battery voltage. Therefore, the vehicle is decelerated when it is determined that the voltage of the in-vehicle battery exceeds a predetermined value.
JP 2000-102116 A

  However, there are cases where it is not possible to sufficiently cope with battery overcharge by simply decelerating the vehicle. For example, depending on the driving area, you may encounter downhill driving immediately after the battery is fully charged. In such a case, charging with the regenerative brake will cause full charging immediately, so avoid overcharging even with deceleration. I can't finish it. Although it is conceivable to stop the vehicle from running when it is fully charged, it is not preferable because it causes inconvenience to the passenger.

  An object of the present invention is made in view of the above-described problems, and provides a small electric vehicle including means capable of avoiding overcharging of a battery due to charging by a regenerative brake immediately after battery charging. There is.

  The present invention relates to a small electric vehicle having means for charging the battery with electric power generated by a regenerative brake of an electric motor that drives wheels with electric power supplied from a vehicle-mounted battery, and finishes initial charging of the battery by an external power source. Charge amount setting means for setting a battery charge capacity limit value serving as a reference to be performed, and means for terminating initial charge when the charge amount of the battery reaches the battery charge capacity limit value. There is a first feature in that the means is configured to set a charge amount less than the battery full charge as a battery charge capacity limit value.

  In the present invention, the charge amount setting means includes a means for setting a battery voltage value corresponding to a full charge of the battery, and a full charge mode for initial charging to a charge amount corresponding to the full charge; A second feature is that it further includes mode switching means for selectively switching between a non-full charge mode in which initial charge is performed to a charge amount less than full charge.

  Further, the present invention has a third feature in that the charge amount setting means is configured to be able to set an arbitrary charge amount within a range of a predetermined value less than full charge or less than full charge as a battery charge capacity limit value. .

  The present invention further includes an operation unit including a plurality of operation switches used for vehicle travel control, and the mode switching unit operates the plurality of operation switches according to a predetermined procedure, and after the operation, the external power supply There is a fourth feature in that when a charger is connected to the battery pack, a preset mode is selected from the full charge mode and the non-full charge mode.

  In the present invention, the mode switching means includes a two-pole connector in which one is connected to the mode selection terminal and the other is connected to the ground, and a short-circuit means for short-circuiting the two poles of the connector, A fifth feature is that the short-circuit means is configured to switch between the full charge mode and the non-full charge mode depending on whether or not the short-circuit means is connected to the connector.

  Furthermore, the present invention has a sixth feature in that the charge amount setting means is configured so that the charge amount can be set by an external terminal equipped with a microcomputer.

  According to the present invention having the first feature, when charging a battery prior to use of the small electric vehicle (in this specification, battery charging performed by an external power source prior to use of the small electric vehicle is referred to as “initial charging”. The charging capacity value less than the full charge of the battery is set as the battery charging capacity limit value, and the initial charging is terminated when the initial charging is performed up to the battery charging capacity limit value. Even if a vehicle equipped with an initially charged battery is used in a usage environment where regenerative braking is heavily used, such as a long downhill immediately after the start of traveling, there is a margin until the battery is fully charged. Can do. Therefore, it is possible to prevent the endurance of the battery from being lost due to overcharging, and not to adversely affect the peripheral device that directly uses the battery voltage. Moreover, since the protection device generally provided from the viewpoint of overvoltage protection is not operated, the problem that the small electric vehicle stops according to the operation of the protection device can be solved.

  According to the present invention having the second feature, an operation suitable for running on a normal relatively flat ground and an operation suitable for running in a mountainous area where battery overcharge with regenerative braking is likely to occur. It can be selected and operated as appropriate.

  According to the present invention having the third feature, in a small electric vehicle that often has a traveling area within a relatively limited area, the amount of decrease from full charge is set to an optimum value as the battery charge capacity limit value. It is possible.

  According to the present invention having the fourth feature, the initial charge mode of the battery is set only by operating an existing operation switch such as a power switch or an accelerator switch according to a predetermined procedure without providing any new parts. be able to.

  According to the present invention having the fifth feature, the charging mode can be easily switched depending on whether or not the connector is short-circuited.

  According to the present invention having the sixth feature, it is possible to arbitrarily input and set the battery charge capacity limit value using an external terminal such as a fault diagnosis device or a personal computer as input means.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 2 is a perspective view of a small electric vehicle according to an embodiment of the present invention, and FIG. 3 is a side view. 2 and 3, the small electric vehicle 1 includes a body frame 2 mainly composed of pipes. The vehicle body frame 2 includes a front frame 2a extending from the front end so as to be inclined downward, an intermediate frame 2b extending rearward from the rear end of the front frame 2a, and a rear frame 2c extending inclined rearward from the intermediate frame 2b. It consists of. The front end of the front frame 2a is welded to the lower end of the support column 3 slightly inclined backward.

  The front frame 2a, the intermediate frame 2b, the rear frame 2c, and the column 3 are respectively provided on the left and right in the width direction of the vehicle body, and each of the left and right frames includes a sub frame 4 and a cross member 5 that extend in the vehicle width direction. And connected to each other. A floor panel 6 is spanned and welded to the pair of left and right intermediate frames 2b.

  A handle column 7 is disposed between the pair of left and right columns 3, and a handle 8 is provided above the handle column 7. The handle column 7 is supported by the support column 3 and the sub frame 4 and connected to a pair of left and right front wheels 9 via a steering mechanism (not shown). A seat frame 10 is welded to the upper end of the rear frame 2 c, and a passenger seat 11 is attached on the seat frame 10.

  A pair of left and right rear wheels 12 are provided at the rear part of the vehicle body. A suspension device for supporting the rear wheel 12 on the vehicle body frame includes a bearing (bush) 13 provided at the rear end of the rear frame 2c and a front end portion by the bearing 13. The rear suspension arm 14 is supported so as to be swingable in the vertical direction, and the telescopic rear damper 15 is supported at the rear end of the rear frame 2c. A support base 16 is welded onto the pair of left and right rear suspension arms 14, and a power unit 17 is mounted on the support base 16. The power unit 17 includes a motor 18 and a speed reducer 19 that decelerates the rotation of the motor 18 and transmits it to the rear wheel shaft 12a. A differential device (not shown) is provided between the rear wheel shaft 12a and the speed reducer 19.

  The body frame 2 is covered with a front cover 20, a leg shield 21, an auxiliary cover 22, a floor panel 23, and a rear cover 24, and the front wheels 9 are covered with individual movable fenders 25.

  An operation unit 26 and a display panel 27 are provided in the center of the handle 8 at the top of the handle column 7. The operation unit 26 is provided with a power switch 26a, a speed limit changeover switch 26b, a forward / reverse changeover switch 26c, an operation mode changeover switch 26d, a blinker switch 26e, and the like. Accelerator levers 28 protrude from the left and right sides of the display panel 27. The accelerator lever 28 is arranged so that the rider can operate it by placing his / her finger on the handle 8 with the palm placed. The accelerator lever 28 is urged by a spring (not shown) so as to return to the neutral position near the front of the vehicle when the hand is released, and when the accelerator lever 28 is rotated forward against the spring, the vehicle is Accelerated. The rotation angle of the accelerator lever 28 can be detected by an angle sensor (accelerator sensor) such as a potentiometer (not shown), and the voltage supplied to the motor 18 is controlled according to the detected angle.

  In addition, when the accelerator lever 28 is grasped by hand together with the handle 8 and pulled toward the front, the electromagnetic brake connected to the motor 18 is activated and the vehicle can be brought to an emergency stop. On the handle 8, a parking brake lever 8A is provided. The parking brake 8 </ b> A is connected to a drum brake provided in the speed reducer 19 via a brake cable 8 </ b> B (only part of which is shown) extended to the speed reducer 19.

  A battery 29 is mounted as a driving power source for the rear wheel 12. The battery 29 is mounted on the vehicle body frame 2 with an appropriate support member such as a bracket attached to the rear frame 2c. The motor 18 is a direct current brushless motor and includes an electromagnetic brake. The electronic control unit (sub ECU) that controls the motor 18 is disposed adjacent to the battery 29, for example.

  FIG. 4 is a control system diagram of the small electric vehicle. This control system includes a motor control unit 30 and a panel control unit 31. The motor control unit 30 includes a motor ECU 33 that controls the motor 18 and an electromagnetic brake 32 coupled to the motor 18. Further, operation information from a power switch 26a, a seat switch 34, an accelerator sensor 35, an operation mode changeover switch 26d and the like as input devices is input to the motor ECU 33, and a blinker lamp 36, a headlight 37, a power relay 38, and the like. A drive command is output.

  The motor 18 acts as a generator during regenerative braking operation. The battery 29 is connected to the sub-ECU 33 so that the battery 29 can be charged with the electric power generated by the regenerative brake. The battery 29 is provided with a charger 39 so that it can be charged with a current supplied from an external AC power source.

  The panel control unit 31 includes a main ECU 40, and operation information from the parking switch 41, the grip switch 42, the winker switch 26e, the forward / reverse switch 26c, and the like is input to the main ECU 40. Further, detection information from the vehicle speed sensor 42 is input to the main ECU 40.

  A result processed by the main ECU 40 based on the operation information and detection information is displayed on the display panel 27. The display items include a battery remaining capacity, a blinker operation, a charge recommendation, and a display indicating that the parking brake is operating.

  The main ECU 40 and the sub ECU 33 constitute a serial bus system connected by a serial bus.

  The sub ECU 33 detects an operation angle of the accelerator sensor 35, that is, the accelerator lever 28, when both the power switch 26a disposed on the operation panel 26 and the seat switch 34 provided in the seat 11 are turned on. The motor 18 and the electromagnetic brake 32 are controlled by reading the angle. When the accelerator lever 28 is in the no-load position, the electromagnetic brake 32 is activated to hold the small electric vehicle 1 in the stopped state. When the accelerator lever 28 is rotated in the acceleration direction, the electromagnetic brake 32 is deactivated and the output of the motor 18 is increased to start and accelerate the small electric vehicle 1. The sub ECU 33 includes a bridge circuit (not shown) including six FETs as a drive circuit for the motor 18, and determines the duty ratio of the FETs by PWM control to drive the motor 18.

  If the accelerator lever 28 is rotated in the deceleration direction while the small electric vehicle 1 is traveling, the motor 18 is decelerated. While the motor 18 is decelerating with the motor 18 being decelerated, the motor 18 that has been decelerated acts as a generator during downhill, and regenerative braking is applied. The electric current generated by the regenerative brake is supplied to the battery 29, and the battery 29 is charged. The sub-ECU 33 is provided with an overvoltage operation suppression function so that the battery 29 is not overcharged by the battery charging by the regenerative brake.

  FIG. 1 is a main part functional block diagram of the sub ECU 33 showing the configuration of the overvoltage operation inhibiting function. In the figure, a charger 39 initially charges a battery 29 with an external power source 51. The external power source 51 is, for example, a commercial AC 100 volt power source. The battery charge capacity limit value storage unit 52 is preset with a battery charge capacity limit value that is a criterion for determining whether or not to end the charging operation when the battery 29 is charged. The battery charge capacity limit value storage unit 52 is provided, for example, on an EEPROM as a peripheral device of the sub ECU 33. The battery charge capacity limit value can be set, for example, by connecting an external terminal 50 having a microcomputer function, such as a failure diagnosis machine or a personal computer of the small electric vehicle 1, to the motor control unit 30. The battery charge capacity limit value in the overvoltage operation suppression mode that operates so as not to overcharge even when encountering a long downhill run where regenerative braking is applied immediately after the end of charging is less than the voltage value when the battery is fully charged (For example, 80% of full charge). In the normal operation mode, the battery charge capacity limit value is a charge amount corresponding to full charge. That is, in the overvoltage operation suppression mode, the battery 29 is initially charged in the non-full charge mode, and in the normal operation mode, the battery 29 is initially charged in the full charge mode.

  The mode input unit 53 is a means for setting the overvoltage operation inhibition mode or the normal operation mode. When the operation mode changeover switch 26d is turned on, the overvoltage operation inhibition mode instruction is issued and the operation mode changeover switch 26d is turned off. Sometimes, an instruction for the normal operation mode is input to the mode setting unit 54, respectively. The mode setting unit 54 is also set on the EEPROM. The mode determination unit 55 determines the operation mode based on the setting content of the mode setting unit 54. The charge capacity detection unit 56 integrates the amount of charge of the battery 29 and inputs it to the charge amount determination unit 57.

  The charge amount determination unit 57 compares the terminal voltage of the battery 29 with the battery charge capacity limit value corresponding to the operation mode, and outputs a charge end command when the terminal voltage of the battery 29 becomes equal to or higher than the battery charge capacity limit value. The charging operation by the charger 39 is terminated.

  The charge control for each operation mode with the above configuration will be described with reference to the flowchart of FIG. Prior to the operation of this figure, the operation mode is set from the mode input unit 53 to the mode setting unit 54, and the battery charge capacity limit value is set in the battery charge capacity limit value storage unit 52.

  When the charger 39 is connected to the AC power source 51 in step S1, the mode determination unit 55 reads the contents of the mode setting unit 54 in step S2. In step S3, the mode determination unit 55 determines whether the operation mode is the overvoltage operation inhibition mode or the normal operation mode. If it is an overvoltage operation inhibition mode, the process proceeds to step S4, and if it is a normal operation mode, the process proceeds to step S5.

  In step S4, a battery charge capacity limit value (for example, a value of 80% of full charge) set to less than full charge for the overvoltage operation suppression mode is input from the battery charge capacity limit value storage unit 52 to the voltage determination unit 57. . In step S <b> 5, the battery charge capacity limit value set to full charge for the normal operation mode is input from the battery charge capacity limit value storage unit 52 to the voltage determination unit 57.

  In step S6, charging is started. In step S <b> 7, the terminal voltage of the battery 29 is input from the voltage detection unit 56 to the voltage determination unit 57. In step S8, the battery charge capacity limit value input in step S4 or step S5 is compared with the actually accumulated battery charge amount.

  In step S7, when it is determined by the charge amount determination unit 57 that the terminal voltage of the battery 29 has become equal to or higher than the battery charge capacity limit value, the process proceeds to step S9 and a charge end command is output from the charge amount determination unit 57. The charging end command is input to the charger 39, and charging of the battery 29 by the external power source 51 is ended.

  The operation of this flowchart is an example and can be modified. For example, instead of starting the charging after determining the operation mode, the procedure may be changed so that the operation mode is determined after the charging is started and the battery charge capacity limit value is set. .

  As described above, according to the present embodiment, in the overvoltage operation suppression mode, the charging operation is terminated when the charging of the battery 29 is completed to the planned value less than the full charge in the initial charging of the battery 29. Therefore, even when the small electric vehicle 1 equipped with the battery 29 after the completion of charging encounters a downhill while using the regenerative brake immediately after the start of traveling, the small electric vehicle 1 travels in a state where there is a margin between the full charge of the battery 29. Since it has started, the battery 29 is prevented from being overcharged.

  The mode determination unit 55 is not limited to determining the operation mode based on the on / off state of the operation mode changeover switch 26d. For example, the mode selection unit 55 pulls out an open terminal for mode selection from the sub ECU 33 in place of the operation mode changeover switch 26d. The operation mode may be set by short-circuiting or opening the open terminal.

  FIG. 6 is a diagram illustrating a configuration example of the operation mode setting unit. In FIG. 6, one of the two lines connected to the mode selection connector 58 is grounded, and the other is connected to the mode selection terminal 331 in the sub ECU 33. A short connector 59 can be connected to the mode selection connector 58. The mode determination unit 55 determines the operation mode according to the state of the mode selection terminal 331. When the short connector 59 is not connected to the mode selection connector 58, the mode selection terminal 331 is at the reference potential, and when the short connector 59 is connected to the mode selection connector 58, the mode selection terminal 331 falls to the ground potential. Constitute. The mode determination unit 54 determines that the normal operation mode is set if the potential of the mode selection terminal 331 is either the reference potential or the ground potential, and determines that the overvoltage operation suppression mode is set if the potential is the other.

  In addition, when a plurality of preset input devices provided in the operation unit 26 are operated in accordance with a preset procedure, either the overvoltage operation suppression mode or the normal operation mode is selected, and the mode determination unit In 55, the operation mode may be determined according to the selection. For example, in a state where the parking brake 8A is applied and the parking switch 41 is turned on, the accelerator lever 28 is pulled to turn on the power switch 26a, and then the accelerator lever 28 is grasped and the grasping switch 42 is turned on. The overvoltage operation inhibition mode is set in the mode setting unit 54 by the above operation. After this setting, when the charger 39 is connected to the external power source 51, the battery 29 is charged in the overvoltage operation inhibition mode. On the other hand, when the charger 39 is connected to the external power source 51 without operating the input device according to a planned procedure, the battery 29 is charged in the normal operation mode.

  When the overvoltage operation suppression mode or the normal operation mode is set in each setting operation, it is preferable to perform display corresponding to the set operation mode. This display may be performed on the display panel 12 or using a lamp provided in the small electric vehicle 1. For example, the headlight blinks when the normal operation mode is set, and the headlight is turned on when the overvoltage operation suppression mode is set. The flashing of the headlight can be performed using a flasher relay for flashing the blinker lamp.

  In addition, the battery charge capacity limit value can be arbitrarily set between 70% and 100%, and the setting is not limited to using the external terminal 50, but a plurality of stages of battery charge capacity is previously stored in a storage device such as a ROM. A limit value may be stored, and the value may be read using an input device provided in the operation unit 26 and written to the mode setting unit 54. For example, one of the blinker switches 26e is pushed, and the other of the blinker switches 26e is pushed in that state, and the battery charge capacity limit value is input by the number of times of pushing. The input battery charge capacity limit value is displayed on the display panel 27, and the current value of the battery charge capacity limit value is changed each time the other side of the blinker switch 26e is pressed so that the current value can be confirmed. To. If the one of the blinker switches 26e is turned off when the current value reaches a desired battery charge capacity limit value, the battery charge capacity limit value is determined.

  As described above, in this embodiment, the battery charge capacity limit value for determining the end of charging of the battery charged by the external power supply is set to an arbitrary value less than the full charge, and the charging operation is performed with the charge less than the full charge. An overvoltage operation suppression mode that can be terminated is provided. Therefore, it is possible to prevent the battery from being overcharged in a usage environment where the vehicle encounters a downhill where the regenerative brake is frequently used immediately after the charged battery is mounted and the vehicle starts running.

  The present invention is not limited to four-wheeled small electric vehicles, but can be widely applied to relatively small low-speed electric vehicles in general.

It is a principal part functional block diagram of sub-ECU which shows the structure of an overvoltage driving | operation suppression function. 1 is a perspective view of a small electric vehicle according to an embodiment of the present invention. 1 is a side view of a small electric vehicle according to an embodiment of the present invention. It is a control system diagram of a small electric vehicle. It is a flowchart of the charge control which concerns on one Embodiment of this invention. It is a figure which shows the structural example of an operation mode setting part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Small electric vehicle, 18 ... Motor, 26 ... Operation part, 27 ... Display panel, 28 ... Accelerator lever, 29 ... Battery, 30 ... Motor control part, 31 ... Panel control part, 32 ... Electromagnetic brake, 33 ... Sub-ECU 35 ... Accelerator sensor, 39 ... Charger, 50 ... External terminal, 51 ... AC power supply, 52 ... Battery charge capacity limit value storage unit, 53 ... Mode input unit, 54 ... Mode setting unit, 55 ... Mode determination unit, 56 ... Voltage detection unit, 57 ... Voltage judgment unit, 58 ... Mode selection connector, 59 ... Short connector

Claims (6)

In a small electric vehicle having means for charging the battery with electric power generated by a regenerative brake of an electric motor that drives a wheel with electric power supplied from a vehicle-mounted battery,
A charge amount setting means for setting a battery charge capacity limit value serving as a reference for terminating the initial charging of the battery by an external power source;
Means for terminating the initial charging when the amount of charge of the battery reaches the battery charge capacity limit value,
The small electric vehicle characterized in that the charge amount setting means is configured to set a charge amount less than the full battery charge as a battery charge capacity limit value. The charge amount setting means includes means for setting a charge amount corresponding to a full charge of the battery;
The apparatus further comprises mode switching means for selectively switching between a full charge mode for initial charge to a charge amount corresponding to the full charge and a non-full charge mode for initial charge to a charge amount less than the full charge. The small electric vehicle according to claim 1.   The small electric vehicle according to claim 2, wherein the charge amount setting means is configured to be able to set an arbitrary charge amount within a range of a planned value less than full charge or less than full charge as a battery charge capacity limit value. An operation unit having a plurality of operation switches used for vehicle travel control is provided.
The mode switching means is a mode set in advance between the full charge mode and the non-full charge mode when the plurality of operation switches are operated according to a predetermined procedure and a charger is connected to the external power source after the operation. The small electric vehicle according to claim 2, wherein the small electric vehicle is selected.   The mode switching means has a two-pole connector, one of which is connected to the mode selection terminal and the other is connected to the ground, and a short-circuit means for short-circuiting the two poles of the connector, and the short-circuit means is connected to the connector. 4. The small electric vehicle according to claim 2, wherein the small electric vehicle is configured to switch between the full charge mode and the non-full charge mode depending on whether or not it is connected.   The small electric vehicle according to any one of claims 1 to 5, wherein the charge amount setting means is configured to set a charge amount with an external terminal equipped with a microcomputer.

Images