A power-off brake device of a brushless motor wheelchair without electromagnetic brake

Abstract

The application discloses a power-off brake device of a brushless motor wheelchair without an electromagnetic brake, which comprises a brake control board connected in series between a wheelchair controller and a wheelchair motor, wherein the brake control board comprises a relay module connected with a power input port, the relay module comprises a relay control circuit and a relay, the relay comprises a left relay and a right relay connected with the relay control circuit respectively, the left relay is connected with a left input port and a left output port respectively, the left input port is connected with a left output port of the wheelchair controller, and the left output port is connected with a left brushless motor, and the right relay is connected with a right input port and a right output port respectively, the right input port is connected with a right output port of the wheelchair controller, and the right output port is connected with a right brushless motor.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electromechanical control, and particularly relates to a power-off brake device of a brushless motor wheelchair without an electromagnetic brake. BACKGROUND

[0002] With the increasingly serious social aging problem in China in recent years, the state has vigorously supported the development of the elderly care, health care and other industries, and the wheelchair, especially the electric wheelchair, as an indispensable part of the industry, has been widely concerned by everyone. The electric wheelchair is generally used by the disabled or the sick, so the driving safety of the electric wheelchair becomes particularly important. If the brushless electric wheelchair without an electromagnetic brake is accidentally powered off during driving, the wheels will have no braking force, and accidental power-off during high-speed or uphill driving may cause harm to the user, which has certain safety hazards. Therefore, the application designs a power-off brake device of a brushless motor wheelchair without an electromagnetic brake. SUMMARY

[0003] In view of the above problems, the application aims to provide a power-off brake device of a brushless motor wheelchair without an electromagnetic brake, which has a power-off automatic brake function and can release the brake state by one key.

[0004] The technical scheme of the application is: a power-off brake device of a brushless motor wheelchair without an electromagnetic brake, comprising a brake control board connected in series between a wheelchair controller and a wheelchair motor, wherein the wheelchair motor comprises a left brushless motor and a right brushless motor, and the brake control board comprises:

[0005] A relay module is connected with a power input port, and the relay module comprises:

[0006] A relay control circuit comprises MOS tube one, a triode one and a plurality of resistors one connected with each other;

[0007] A relay comprises a left relay and a right relay connected with the relay control circuit, respectively, wherein the left relay is connected with a left input port and a left output port, respectively, the left input port is connected with a left output port of the wheelchair controller, and the left output port is connected with the left brushless motor; the right relay is connected with a right input port and a right output port, respectively, the right input port is connected with a right output port of the wheelchair controller, and the right output port is connected with the right brushless motor;

[0008] A backup power module is connected with the relay control circuit of the relay module, and is used for supplying power to the relay module when the power input port is powered off; a state switching button is connected in series between the backup power module and the relay module through a wire, and is used for switching the connection and disconnection state of the backup power module and the relay module.

[0009] Further, the relay module and the power input port are sequentially connected with:

[0010] The overvoltage protection circuit is used for power-off protection when the voltage of the power input port is abnormal, so as to avoid damage of the device caused by abnormal input voltage.

[0011] The power conversion circuit is used for voltage reduction of the input power of the power input port.

[0012] Further, the overvoltage protection circuit includes a zener diode, two triodes, two MOS tubes and a plurality of resistors, wherein the zener diode is SMBJ5363B, the two triodes are MMBT5401, the two MOS tubes are P-channel NCE01P18K, the turn-on voltage of the zener diode is 32V, the two MOS tubes are turned on to normally supply power when the voltage input by the power input port is lower than 32V, and the two MOS tubes are turned off to cut off power when the voltage input by the power input port is higher than 32V, thereby protecting the brake control board.

[0013] Further, the power conversion circuit includes a DC-DC conversion chip, a diode, a plurality of capacitors and an inductor, the DC-DC conversion chip is LM2596S-5.0, the voltage input has a wide voltage range of 5.5V-40V, the output is 5V, and the output current is 3A.

[0014] Further, the power conversion circuit is further connected with the backup power module through a lithium battery charging module, is used for charging the backup power module by using the power input port through the overvoltage protection circuit, and the lithium battery charging module includes a lithium battery charging management chip and a charge and discharge protection circuit, the lithium battery charging management chip adopts a core board with a TC4056 single lithium battery charging management chip as the core.

[0015] Further, the backup power module includes a lithium battery and a battery seat, the lithium battery is connected and arranged in the battery seat, the battery seat is connected with the power conversion circuit through the lithium battery charging module, the lithium battery is a 3.7V, 850mah 14500 battery, and the battery seat is a straight insertion type 14500 battery seat.

[0016] Further, the MOS tube one is AO3401, the triode one is MMBT4401, and the left relay and the right relay are both double-channel normally closed relays with the model of HF115F / 005-2ZS4AF.

[0017] The working principle of the application is as follows:

[0018] Normal operation state: the power input port supplies power to the relay module, the relay is powered on to open, the left relay and the right relay switch from the normally closed contact to the normally open contact, the UVW three-phase lines of the left brushless motor and the right brushless motor switch from the mutual short circuit state to the mutual open circuit state, at this time the wheelchair exits the brake state and operates normally;

[0019] Normal shutdown or accidental power-off state: the brake control board is powered off, the contacts of the left relay and the right relay are in the normally closed state, the UVW three-phase lines of the left brushless motor and the right brushless motor are mutually short-circuited, at this time the motor is in the braking state; when the wheelchair is normally shut down and needs to be pushed, only need to press the state switching button on the brake control board to switch to the backup power module power supply, at this time the backup power supply opens the left relay and the right relay, the wheelchair exits the braking state, the UVW three-phase lines of the left brushless motor and the right brushless motor switch from the mutual short circuit state to the mutual open circuit state, at this time the wheels of the wheelchair are in a free state and can be easily pushed, to exit the free pushing state, only need to press the state switching button again to enter the braking state, achieving the switching purpose of the wheelchair from the braking state to the free state.

[0020] Compared with the prior art, the brake device of the brushless motor wheelchair without electromagnetic brake provided by the application solves the problem that the wheels of some brushless motor wheelchairs without electromagnetic brake lose braking force in the case of shutdown or accidental power-off, at this time if the wheelchair is running on an uphill or downhill section, the wheelchair will lose speed, by setting double-channel normally closed relays on the brake control board, using the normally closed characteristics of the relay power-off, using the relay to control the running state of the brushless motor, and connecting a backup power module on the brake plate through a state switching button, in the case of wheelchair power-off braking, the backup power supply is used to remove the braking state, the wheelchair can be freely pushed in the case of wheelchair shutdown. In summary, the application has the advantages of reasonable design, simple structure, high safety, adjustable braking state, etc., and can ensure the safety of the user's life and property. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of the overall structure of the application;

[0022] Figure 2 is a schematic diagram of the overvoltage protection circuit of the application;

[0023] Figure 3 is a schematic diagram of the power conversion circuit of the application;

[0024] Figure 4 is a schematic diagram of the lithium battery charging module circuit of the application;

[0025] Figure 5 is a schematic diagram of the relay module control circuit of the application.

[0026] Wherein, 1-Overvoltage protection circuit, 11-Zener diode, 12 triode two, 13-MOS tube two, 14-Resistance two, 2-Power conversion circuit, 21-DC-DC conversion chip, 22-diode, 23-capacitor, 24-inductor, 3-Lithium battery charging module, 31-lithium battery charging management chip, 32-charging and discharging protection circuit, 4-Backup power module, 41-lithium battery, 42-battery holder, 5-relay module, 51-relay control circuit, 511-MOS tube one, 512-triode one, 513-resistor one, 52-relay, 521-left relay, 522-right relay, 6-state switching button, 7-power input port. DETAILED DESCRIPTION

[0027] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings, but it should be understood that the scope of protection of the present application is not limited by the specific embodiments.

[0028] Embodiment: as shown in a brushless motor wheelchair without electromagnetic brake power-off brake device, including the brake control board connected in series between the wheelchair controller and wheelchair motor, wheelchair motor includes left brushless motor and right brushless motor, brake control board includes: Figure 1 Relay module 5, with power input port 7, relay module 5 includes:

[0029] Relay control circuit 51, including MOS tube one 511, triode one 512 and a plurality of resistor one 513 connected with each other, MOS tube one 511 model is AO3401, triode one 512 model is MMBT4401;

[0030] Relay 52, including left relay 521 and right relay 522 connected with relay control circuit 51 respectively, left relay 521 and right relay 522 are both double channel normally closed type relay with model HF115F / 005-2ZS4AF, left relay 521 is respectively connected with left input port 8 and left output port 9, left input port 8 is connected with left output port of wheelchair controller, left output port 9 is connected with left brushless motor, right relay 522 is respectively connected with right input port 10 and right output port 11, right input port 10 is connected with right output port of wheelchair controller, right output port 11 is connected with right brushless motor;

[0031] Relay module 5 and power input port 7 are sequentially connected with:

[0032]

[0033] ​The overvoltage protection circuit 1 is used for power-off protection when the voltage of the power input port 7 is abnormal, and the overvoltage protection circuit 1 comprises a zener diode 11, a transistor 12, a MOS tube 13 and a plurality of resistors 14, wherein the zener diode 11 is of SMBJ5363B type, the transistor 12 is of MMBT5401 type, the MOS tube 13 is of P-channel NCE01 P18K, the turn-on voltage of the zener diode 11 is 32V, the MOS tube 13 is turned on to normally supply power when the voltage input by the power input port 7 is lower than 32V, and the MOS tube 13 is turned off to cut off power when the voltage input by the power input port 7 is higher than 32V, thereby protecting the brake control board, and the principle is as shown in Figure 2

[0034] The power conversion circuit 2 is used for step-down conversion of the input power of the power input port 7, and the power conversion circuit 2 comprises a DC-DC conversion chip 21, a diode 22, a plurality of capacitors 23 and an inductor 24, the DC-DC conversion chip 21 is of LM2596S-5.0 type, has a wide voltage range of 5.5V-40V for voltage input, outputs 5V, and has an output current of 3A, and the principle is as shown in Figure 3

[0035] The standby power module 4 is connected with the relay control circuit 51 of the relay module 5, and is used for supplying power to the relay module 5 when the power input port 7 is powered off, and the standby power module 4 and the relay module 5 are connected in series through a wire and a state switching button 6, which is used for switching the connection and disconnection state of the standby power module 4 and the relay module 5.

[0036] The power conversion circuit 2 is further connected with the standby power module 4 through the lithium battery charging module 3, and is used for charging the standby power module 4 by the power input port 7 through the overvoltage protection circuit 1, the lithium battery charging module 3 comprises a lithium battery charging management chip 31 and a charge and discharge protection circuit 32, the lithium battery charging management chip 31 adopts a core board with TC4056 single lithium battery charging management chip as the core, and the principle is as shown in Figure 4 The standby power module 4 comprises a lithium battery 41 and a battery seat 42, the lithium battery 41 is arranged in the battery seat 42, the battery seat 42 is connected with the power conversion circuit 2 through the lithium battery charging module 3, the lithium battery 41 is a 14500 battery with 3.7V and 850mah, and the battery seat 42 is a 14500 battery seat of direct insertion type.

[0037] The working principle of the above embodiment is as follows:

[0038] ​​Normal running state: the power input port 7 supplies power to the relay module 5, the relay 52 is powered on, the left relay 521 and the right relay 522 are switched from the normally closed contact to the normally open contact, and the UVW three-phase lines of the left brushless motor and the right brushless motor are switched from the short-circuit state to the open-circuit state, at this time the wheelchair exits the brake state and runs normally;

[0039] Normal shutdown or accidental power-off state: the brake control board is powered off, the contacts of the left relay 521 and the right relay 522 are in the normally closed state, and the UVW three-phase lines of the left brushless motor and the right brushless motor are short-circuited, at this time the motor is in the braking state; when the wheelchair is pushed in the normal shutdown state, only need to press the state switching button 6 on the brake control board to switch to the backup power module 4, at this time the backup power supply opens the left relay 521 and the right relay 522, the wheelchair exits the braking state, and the UVW three-phase lines of the left brushless motor and the right brushless motor are switched from the short-circuit state to the open-circuit state, at this time the wheels of the wheelchair are in the free state and can be easily pushed, to exit the free pushing state, only need to press the state switching button 6 again to enter the braking state, achieving the switching purpose of the wheelchair from the braking state to the free state, as shown in the principle. Figure 5

[0040] The specific models of some of the above electronic components are not specially specified, and ordinary products on the market can be selected as long as they can meet the use requirements of the present application.

[0041] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application, and it should be understood that the above description is only a specific embodiment of the present application and does not limit the present application, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application are included in the protection scope of the present application.​

Claims

1. A power-off brake device of a brushless motor wheelchair without electromagnetic brake, comprising a brake control board connected in series between a wheelchair controller and a wheelchair motor, the wheelchair motor comprising a left brushless motor and a right brushless motor, characterized in that, The brake control board comprises: A relay module (5) connected with a power input port (7), the relay module (5) comprising: A relay control circuit (51); A relay (52) comprising a left relay (521) and a right relay (522) respectively connected with the relay control circuit (51), the left relay (521) being provided with a left input port (8) and a left output port (9), the left input port (8) being connected with a left output port of the wheelchair controller, the left output port (9) being connected with the left brushless motor, the right relay (522) being provided with a right input port (10) and a right output port (11), the right input port (10) being connected with a right output port of the wheelchair controller, the right output port (11) being connected with the right brushless motor; A backup power module (4) connected with the relay control circuit (51) and the relay (52), for supplying power to the relay control circuit (51) and the relay (52) when the power input port (7) is powered off, the backup power module (4) and the relay control circuit (51) being connected in series through a wire and a state switching button (6), for switching the connection and disconnection state of the backup power module (4) and the relay control circuit (51); The relay module (5) and the power input port (7) are connected in sequence: An overvoltage protection circuit (1) for power-off protection when the voltage of the power input port (7) is abnormal; A power conversion circuit (2) for step-down of the input power of the power input port (7); When the voltage input by the power input port (7) is lower than 32V, the overvoltage protection circuit (1) is turned on for normal power supply, and when the voltage input by the power input port (7) is higher than 32V, the overvoltage protection circuit (1) is turned off for power-off, protecting the brake control board.

2. A power-off braking device for a brushless motor wheelchair without electromagnetic brake according to claim 1, characterized in that, The voltage input of the power conversion circuit (2) has a wide voltage range of 5.5V-40V, and outputs 5V with an output current of 3A.

3. A power-off braking device for a brushless electric motor wheelchair without electromagnetic brake according to claim 1, characterized in that, The power conversion circuit (2) is further connected with the backup power module (4) through a lithium battery charging module (3), for charging the backup power module (4) by the power input port (7) through the overvoltage protection circuit (1), the lithium battery charging module (3) comprising a lithium battery charging management chip (31) and a charge and discharge protection circuit (32).

4. A power-off braking device for a brushless electric motor wheelchair without electromagnetic brake according to claim 3, characterized in that, The backup power module (4) comprises a lithium battery (41) and a battery seat (42), the lithium battery (41) being connected and arranged in the battery seat (42), the battery seat (42) being connected with the power conversion circuit (2) through the lithium battery charging module (3).

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