JP2001120604A - Electric wheelchair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric wheelchair solving such a problem that the weight of the chassis of the electric wheelchair can be reduced if a lightweight alkali battery is employed in the wheelchair but the running distance of the wheelchair is lowered because the capacity of the battery is small and a user of the wheelchair is hard to look at an accurate residual quantity meter because the residual quantity meter must be built in the main body of the battery. SOLUTION: The running distance of an electromotive wheelchair is extended by driving an electromotor by a combination of the battery 4 for a main power supply and battery 5 for an auxiliary power supply mounted on the wheelchair doubly. At this time, control is wholly performed by the main power supply and the changeover of the power supplies is performed during the running of the wheelchair and, further, the residual quantity of the main power supply is displayed on this side and a user of the wheelchair obtains residual quantity data within a real time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric wheelchair driven by an electric motor.

[0002]

2. Description of the Related Art Wheelchairs are widely used as a means of transportation when a person has a physical disability or is unable to walk due to old age. This wheelchair is roughly classified into a so-called manual type driven by a user or a caregiver's hand and an electric type driven by an electric motor. In particular, when manual propulsion cannot be obtained due to severe obstacles or old age, the electric type is used. In this electric type, an electric motor is connected to a pair of left and right drive wheels by an appropriate transmission means, while a user inputs a traveling direction by a hand operation unit provided at hand and operates a wheelchair. .

FIG. 3 shows a typical electric wheelchair. The electric motors 2 are respectively connected to the left and right rear wheels 10 via reduction gears, and the user can tilt the hand operation unit 9 and the lever 11 in desired directions. The signal is sent to the control unit below the seat, and the conditions for operating the left and right motors are determined,
According to the conditions, the electric energy from the storage battery provided at the lower part of the seat is supplied to the electric motor to drive the wheelchair. The electric wheelchair according to this embodiment is used internationally as a standard type. The power supply used in this wheelchair is mainly a lead storage battery, which can provide a large capacity, but on the other hand increases the weight of the vehicle body.

[0004]

On the other hand, there is a strong demand for an electric wheelchair which can be loaded and conveyed on a car, while wishing for a wider activity while using the electric wheelchair. In order to achieve this, it is essential to significantly reduce the weight of the vehicle body. Therefore, those equipped with an alkaline storage battery have recently been put to practical use.

The alkaline storage battery specifically includes a nickel-cadmium battery and a nickel-hydrogen battery which is a clean battery. .

FIG. 4 shows an example. This wheelchair is of a six-wheel type, is located at the center between the front and rear of the drive wheels, and has a control unit 3 having a main power storage unit between the left and right electric motors 2, in which a main power supply 4 is stored. However, these batteries have a capacity of 2 to 3 Ah, and even the largest one has a capacity of 7 Ah, which is smaller than the conventional lead-acid battery of 30 Ah. Accordingly, the traveling distance is shortened accordingly, so that the efficiency of the electric motor and the speed reducer incorporated therein is improved, and the control unit and the electromagnetic brake are made energy-saving to extend the traveling distance. Even if various measures are taken, the traveling distance is about 5 km to 12 km, and the conventional 15 km
Compared to 20km, the range of use is limited. In addition, 15km which is standard of electric wheelchair in Europe
The above cannot be satisfied.

[0007]

SUMMARY OF THE INVENTION In the electric wheelchair of the present invention, a lightweight alkaline storage battery is used, and a combination of two batteries of a main power supply and an auxiliary power supply is used.
A travel distance of more than km is possible.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The wheelchair of the present invention has a dual main power supply and auxiliary power supply, and is capable of traveling over a long distance of 15 km or more. By making the capacity smaller than that of the power supply, the weight can be reduced. Furthermore, when both the main power and the auxiliary power can be used, the auxiliary power is preferentially used for driving the motor, so that it can be removed and charged while driving with the main power after using the auxiliary power, Wheelchair mileage can be further extended. In addition, since the main control unit of the wheelchair is always driven by the main power supply, even if the power supply for driving the motor is switched from the auxiliary power supply to the main power supply, the wheelchair can be smoothly and safely and reliably without stopping, and the auxiliary power supply can be used. The wheelchair can be used without any problems with the main power supply even when detached from the vehicle body. Since the battery remaining amount information of the main power supply is sent to the hand operation unit by the communication means via the main control unit microcomputer, a harness for displaying the remaining amount is unnecessary, and the accurate remaining battery amount of the main power supply is determined by a wheelchair. It is sent to the user in real time, improving convenience.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the electric wheelchair of the present invention will be described below based on embodiments.

(Embodiment 1) FIG. 1 shows an electric wheelchair according to the present invention. An electric motor 2 having a speed reducer and an electromagnetic brake is connected to a pair of left and right wheels 1 by a suitable connecting means. This motor is electrically connected to the control unit 3 installed between the left and right motors. A battery 4, which is a main power supply, is disposed in front of the control unit, and is electrically connected to the control unit. Further, the control unit 3
Has a space into which the auxiliary power supply battery 5 is inserted. The battery 4 for the main power supply has a built-in battery fuel gauge, and the remaining battery information is sent to a microcomputer built in the control unit. Sent to the unit 9 and
It is displayed by optical means such as ED. When the wheelchair user operates the operation unit, a signal of the traveling direction and speed of the wheelchair is sent from the operation unit to the control unit 3 and is calculated by a microcomputer built in the control unit to determine conditions for driving the left and right electric motors. The electric wheelchair operates by supplying electric energy supplied from the main power supply to the left and right electric motors.

When the voltage of the main power supply falls below a specified value, the microcomputer with the built-in control unit switches the electric energy source supplied to the left and right electric motors to the auxiliary power supply. FIG.
The control block diagram is shown in FIG. The main power supply is connected to a control circuit and an operation unit composed of a logic circuit (MPU is clearly shown in the figure) and a power circuit (shown as PWM in the figure) and power supply selection means by the microcomputer, and drives each circuit. The MPU operates the PWM and supplies necessary electric energy to the left and right electric motors based on the traveling direction and the speed command sent from the operation unit.

When the power of the electric wheelchair is turned on, the MPU of the control unit checks whether or not the voltages of the main power supply and the auxiliary power supply are higher than specified values.
The power supply for the motor is supplied from the auxiliary power supply, and the power supply for the control circuit is supplied from the main power supply to operate the electric wheelchair. At this time, if the voltage of the main power supply is equal to or less than the specified value, the battery is deficient and abnormal processing is performed, and the electric wheelchair is in an inoperative state. Also,
When only the voltage of the auxiliary battery is lower than the specified value, not only the control power but also the power for driving the motor is supplied from the main power.

In this method, since the control circuit is always controlled by the main power supply, the circuit configuration and its software are simplified and malfunctions can be avoided as compared with the case where all are switched. Further, when the auxiliary power supply voltage becomes equal to or lower than the in-use specified value for driving the motor, the MPU switches the motor drive power supply from the auxiliary power supply to the main power supply. In this case, the process is executed by the process shown in FIG. At the time point t1 when the auxiliary power becomes lower than the specified voltage, the control unit MPU stops the PWM. In this state, no electricity is supplied to the left and right motors, so the motors are in a non-energized state, and the wheelchair is moving by inertia. In this state, the speed gradually decreases due to the running resistance, and finally the wheelchair stops at t0, but the main power is turned on at t2 while the vehicle is running with this inertia. The time when the user of the wheelchair does not feel stress even when switching the power while driving is from about t1 to t2 within about 0.5 seconds,
If the switching is performed during this time, the speed of the wheelchair is temporarily reduced, but when the main power is turned on at t2, the speed is restored to the original speed, and it is felt that the vehicle is traveling almost continuously. In the present invention, since the control unit power is always supplied from the main power source, there is no problem even in such battery switching because the control unit is driven stably.

[0014] Since the running distance of the wheelchair becomes shorter as the body weight becomes heavier, it is desirable that the wheelchair be as light as possible from the viewpoint of energy saving. Therefore, the battery used for the auxiliary power source should adopt a small capacity that is lighter than that of the main power source, and the type of the battery is actually limited to the alkaline storage battery from this viewpoint. . As a specific example, a nickel hydrogen battery 7Ah is used as a main power source and a nickel hydrogen battery 3Ah is used as an auxiliary power source. However, a nickel cadmium battery may be used.

As described above, the electric wheelchair is desired to be lightweight from the viewpoint of energy saving. However, the lightness further enables the electric wheelchair to be transported by a car and used at a destination, thereby greatly increasing its convenience. For this purpose, it is preferable that the power supply can be used without an auxiliary power supply depending on the usage distance.Moreover, the fact that the auxiliary power supply can be removed from the vehicle body and charged while using the electric wheelchair with the main power supply will further enhance its convenience. Better.

However, shortly after the use of the auxiliary power supply is temporarily stopped, the terminal voltage of the auxiliary power supply recovers from when the auxiliary power supply is stopped. If the power of the wheelchair is turned on again while the used auxiliary power is not charged and installed, the MPU checks the voltage of both power supplies again at that time.
The specified voltage for determining whether or not to use the auxiliary power supply for driving the motor is naturally 20 V in the case of the auxiliary power supply stop voltage and the rated voltage of 24 V, but is set to a higher voltage, for example, 23 V. I have to. By doing so, even if the power of the wheelchair is turned on with the empty auxiliary power supply mounted, the MP
Since U selects the main power source and drives the wheelchair, an empty auxiliary power source is selected, and switching of the main power source from the auxiliary power source immediately after the start of operation does not occur.

(Embodiment 2) FIG. 6 shows a hand operation section according to another embodiment of the present invention. The hand operation unit includes a so-called joystick operation unit 11, a wheelchair power switch 14, a speed selection button 15, a main power remaining amount display LED 13, an auxiliary power monitor LED 16, and an abnormality alarm LED 17. When the user of the wheelchair turns on the wheelchair power switch, the main control unit MPU performs an initial check of the control circuit, the drive unit sensor and the main and auxiliary power supplies, and when all are normal, selects the auxiliary power supply for driving the motor. Wheelchairs are available. When the user selects the maximum speed with the selection button 15 and tilts the hand operation unit 11 in a desired direction, the coordinate axes are sent to the MPU by serial communication to operate the left and right motors. The remaining battery information of the battery fuel gauge built into the main power supply is sent to the MPU according to a standard method and sent as digital information to the hand operation unit by serial communication, and a combination of turning on, blinking, and turning off the five LEDs Are displayed in six stages. As for the auxiliary power supply, the one LED turns on when it can be used, runs low when it is available, blinks when the battery runs out soon, switches to the main power supply when the battery runs out, or when the auxiliary power supply is not installed Is turned off, and the wheelchair user can know the remaining amount of power in real time, further improving the convenience of the wheelchair.

[0018]

As is apparent from the above description, claim 1
According to (5), even if a small and lightweight alkaline storage battery is used as the power supply for the electric wheelchair, the main power supply can be used while charging while removing the auxiliary power supply, so that the wheelchair can be used continuously. The shortcoming of a short running distance can be covered.

According to the present invention, the power supply can be switched without giving a shock to the driver.

According to the seventh aspect of the present invention, it is possible to prevent the empty auxiliary battery from being erroneously determined to be usable.

According to the eighth aspect of the present invention, since accurate battery remaining amount information is displayed on the hand operation section which is easy for the driver to see, the driver can operate the vehicle without noticing that the battery remaining amount is low. It is possible to prevent a trouble that the wheelchair cannot be moved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention.

FIG. 2 is a control block diagram of the present invention.

FIG. 3 shows an example of a conventional electric wheelchair.

FIG. 4 shows an example of a conventional electric wheelchair.

FIG. 5 is a diagram showing an example of an electric wheelchair power supply switching process of the present invention.

FIG. 6 is a diagram showing an example of an electric wheelchair hand operation unit of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wheel 2 motor 3 control unit 4 battery for main power supply 5 battery for auxiliary power supply 7 seat 8 armrest 9 operation unit 10 rear wheel 11 operation unit lever 13 main power remaining amount display device 14 power switch 15 speed selection button 16 auxiliary power monitor display Device 17 Abnormal alarm display device

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yukihiro Ashizaki 1006 Kadoma, Kazuma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (8)

[Claims] 1. An electric wheelchair having a dual main power supply and auxiliary power supply. 2. The electric wheelchair according to claim 1, wherein the main power supply and the auxiliary power supply are constituted by alkaline batteries. 3. The electric wheelchair according to claim 1, wherein the capacity of the auxiliary power supply is smaller than that of the main power supply. 4. The control circuit according to claim 1, wherein the control circuit is driven by the main power supply, and when the voltage of both the auxiliary power supply and the main power supply is equal to or higher than a specified value, the auxiliary power supply is preferentially used as the motor drive power supply. Item 4. The electric wheelchair according to item 1, 2 or 3. 5. The electric wheelchair according to claim 1, wherein the auxiliary power supply is detachable from the vehicle body and can be used by the main power supply even when the auxiliary power supply is disconnected from the main body. 6. The electric wheelchair according to claim 1, wherein the power supply is switched to the main power supply within a time when the wheelchair does not stop when the auxiliary power supply voltage becomes equal to or lower than a specified voltage. . 7. When the power of the electric wheelchair is turned on, whether or not to use the auxiliary power supply is determined based on the auxiliary power supply voltage.
7. The electric wheelchair according to claim 1, wherein the voltage is set higher than the auxiliary power supply stop voltage. 8. The battery control device according to claim 1, wherein the information on the remaining battery level contained in the main power supply is sent to a microcomputer of the main control circuit, further sent to a hand operation unit by a communication means, and displayed. The electric wheelchair according to 2, 3 or 4.