Household appliance door lock assembly based on single-wire communication and control method thereof

Abstract

The invention relates to the technical field of household appliance door lock assemblies, and provides a household appliance door lock assembly based on single-wire communication and a control method thereof.The household appliance door lock assembly based on single-wire communication comprises a door lock control device in communication connection with a main control panel and a door lock motor used for driving a lock rod to open and close a door body; the door lock control device comprises a door lock control panel, a motor driving module and a locked-rotor detection module; the motor driving module is electrically connected with the door lock control panel; the locked-rotor detection module is electrically connected with the door lock control panel and used for monitoring the working current of the door lock motor in real time so as to send a locked-rotor signal to the door lock control panel when the current exceeds a preset threshold value, and then the door lock control panel is triggered to send an instruction to the motor driving module to control the door lock motor to execute a protection mechanism action. The door lock control panel can independently receive door opening and closing instructions of the main control panel and door lock state information so as to drive the door lock motor to make corresponding actions.

Description

Technical Field

[0001] This invention relates to the technical field of door lock components for household appliances, and specifically to a door lock component for household appliances based on single-wire communication and its control method. Background Technology

[0002] The existing automatic door lock assemblies for home appliances only transmit the minimum and maximum travel button trigger signals through their internal control boards. feedback The main control board is used to control the door lock motor and complete the door opening and closing actions. The door lock control board inside the door lock assembly cannot independently complete the minimum / maximum stroke detection, autonomously realize the door opening and closing operation, and cannot detect the working status of the door lock motor to perform anti-pinch operation. Summary of the Invention

[0003] This invention proposes a door lock component for home appliances based on single-wire communication and its control method. By setting up a door lock control board, a motor drive module and a stall detection module, intelligent and autonomous control of the door lock component is achieved.

[0004] A household appliance door lock assembly based on single-wire communication designed for this purpose includes a door lock control device that communicates with the main control board, and a door lock motor for driving the lock rod to extend and retract to open and close the door. The door lock control device includes a door lock control board, a motor drive module, and a stall detection module; The door lock control board is used to receive door opening and closing commands sent by the main control board, as well as door lock status signals from the main control board; The motor drive module is electrically connected to the door lock control board and is used to drive the door lock motor to perform forward rotation, reverse rotation or braking actions according to the instructions of the door lock control board. The stall detection module is electrically connected to the door lock control board and is used to monitor the operating current of the door lock motor in real time. When the current exceeds a preset threshold, it sends a stall signal to the door lock control board, thereby triggering the door lock control board to send a command to the motor drive module to control the door lock motor to perform the protection mechanism action.

[0005] The door lock control device also includes a self-locking protection module for providing mechanical locking function in case of abnormal door opening, and the self-locking protection module is electrically connected to the door lock control board.

[0006] The self-locking protection module includes a voltage limiting unit and a grounding switch unit; The positive power supply circuit of the door lock motor is electrically connected to the voltage limiting unit via the P04 pin of the door lock control board. The negative circuit of the door lock motor is electrically connected to the P10 pin of the door lock control board and the grounding switch unit, respectively. When an abnormal door opening triggers the self-locking protection module, the P04 pin of the door lock control board outputs a PWM signal, the P10 pin of the door lock control board outputs a high level, and the door lock control board controls the motor drive module to enter a high-impedance state. The voltage limiting unit includes a PMOS switch and an energy storage capacitor C2. When an abnormal door opening occurs, the door lock control board outputs a PWM signal through the P04 pin to control the duty cycle of the PMOS switch and limit the positive voltage of the door lock motor. The grounding switch unit includes an NMOS transistor. When the P10 pin of the door lock control board outputs a high level, the NMOS transistor is turned on, forcibly grounding the negative terminal of the door lock motor.

[0007] The stall detection module includes a current sampling unit and a signal conversion unit; the current sampling unit is electrically connected to the motor drive module and is used to convert the operating current of the door lock motor into a detection voltage. The input terminal of the signal conversion unit is electrically connected to the current sampling unit, and the output terminal of the signal conversion unit is electrically connected to the door lock control board. The current sampling unit is a first resistor, and the signal conversion unit is an analog-to-digital converter (ADC) built into the door lock control board. The voltage of the first resistor is detected and the current value is calculated through the P03 pin of the door lock control board. Alternatively, the current sampling unit is a second resistor, and the signal conversion unit includes an NMOS transistor. When the voltage of the second resistor exceeds the threshold voltage of the NMOS transistor, the NMOS transistor is turned on to pull the stall detection IO of the door lock control board low to GND. When the stall detection module continuously detects an abnormal current within a predetermined time, the door lock control board executes the following protection command: The door lock control board changes the H-bridge control level of the motor drive module through pins P06 and P23, causing the door lock motor to run in reverse. When the lock rod reaches the opposite position switch, the door lock control board changes the level of pins P06 and P23 again, causing the door lock motor to resume its original direction of movement until it reaches the position switch in the original direction of movement of the lock rod. If the stall detection module still detects an abnormal current during the process of the lock rod resuming its original movement, the door lock control board controls the door lock motor to run in reverse until the lock rod reaches the safe position. After that, the door lock control board outputs a braking level through pins P06 and P23, the door lock motor stops running, and the door lock control board reports the stall information to the main control board.

[0008] The door lock control device also includes a travel detection module, which is electrically connected to the door lock control board and is used to detect the travel position of the lock rod. The travel detection module includes a limit switch and a reset switch. The limit switch is electrically connected to the P11 pin of the door lock control board and is used to detect the extended position of the lock rod. The reset switch is electrically connected to the P05 pin of the door lock control board and is used to detect the fully retracted position of the lock rod.

[0009] The door lock control device also includes a door status detection module, which is electrically connected to the main control board. The main control board detects the opening and closing status of the door through the corresponding micro switch in the door status detection module and feeds back the door status information to the door lock control board through single-wire communication. The door lock control board controls the motor drive module to perform corresponding opening and closing actions based on the door status information and door opening and closing action commands fed back by the main control board. The door status detection module includes a micro switch DoSW, one end of which is grounded and the other end of which is electrically connected to the DOOR detection port of the main control board. The main control board detects high and low levels through the DOOR port to obtain the state of the micro switch DoSW.

[0010] The main control board and the door lock control board are provided with a data port for single-line communication, and a timer is provided between the main control board and the door lock control board for detecting the running time of the door lock motor driving the lock rod during the opening and closing process of the door. A timer is also provided between the main control board and the door lock control board to generate a periodic time base signal, which triggers single-line communication between the main control board and the door lock control board in each time base period.

[0011] A control method for a household appliance door lock component based on single-wire communication as described above, wherein the door lock control device further includes a self-locking protection module, a travel detection module, and a door status detection module electrically connected to the door lock control board; The control method for the household appliance door lock component based on single-wire communication includes the following control logic: The main control board sends door opening and closing commands to the door lock control board via a single-wire communication interface; Normal door opening and closing procedure: After the door lock control board parses the command: the door lock control board controls the motor drive module to execute the corresponding movement through pins P06 and P23; the door lock control board monitors the position of the lock bar in real time through the travel detection module; when the limit switch or reset switch is triggered by the lock bar, the door lock control board outputs a brake level through pins P06 and P23, and the door lock motor stops running; Stall protection control process: The stall detection module monitors the door lock motor current in real time. When the door lock motor current continuously exceeds the threshold: When the first stall occurs, the door lock control board controls the door lock motor to run in reverse via pins P06 and P23. When the lock rod reaches the opposite position switch, the door lock motor resumes its original direction of movement until the lock rod reaches the original position switch. If the door lock motor stalls again during the process of the lock rod reaching the original position switch, the door lock control board controls the door lock motor to run in reverse until the lock rod reaches the safe position. After that, the door lock control board outputs a brake level via pins P06 and P23, the door lock motor stops running, and the door lock control board reports the stall information to the main control board. Self-locking protection control process: When the door status detection module detects that the door is closed: if the number of times the reset switch is abnormally disconnected reaches N times; the door lock control board controls the lock rod to automatically reset through the door lock motor; the door lock control board outputs a PWM signal through the P04 pin to limit the door lock motor voltage, and the door lock control board outputs a high level through the P10 pin to turn on the grounding switch, controlling the motor drive module to enter a high impedance state.

[0012] The timer detects when the duration of the door lock motor driving the lock rod during the door opening and closing process reaches a preset time value. After receiving the timer signal, the door lock control board sends a command to the motor drive module to control the door lock motor to stop running.

[0013] If the content of the single-line communication between the main control board and the door lock control board is disordered or unchanged within the corresponding set time value, the single-line communication between the main control board and the door lock control board is in a failed state. At this time, the door lock control board automatically detects the reset switch. If the lock rod does not reach the reset switch, the door closing logic is automatically started, the door lock motor rotates, and after the lock rod reaches the reset switch, the door lock motor stops running.

[0014] During the abnormal door opening process, when the locking rod is abnormally pulled out under the action of external force, the locking rod disengages from the reset switch of the stroke detection module. The door lock control board sends a command to the motor drive module to make the door lock motor drive the locking rod to automatically retract back to its original position. After the locking rod reaches the reset switch, the door lock motor stops operating and the number of abnormal door opening processes is accumulated. When the number of abnormal door opening attempts reaches the required number, the lock rod returns to its reset state, triggering the self-locking protection module to activate the self-locking circuit. During abnormal door closing, if the locking rod is in the limited extension state and is impacted by an external force, it will disengage from the door limit state. The locking rod will disengage from the limit switch of the travel detection module. The door lock control board will send a command to the motor drive module to make the door lock motor drive the locking rod to automatically retract back to its original position. After the locking rod reaches the reset switch, the door lock motor will stop operating.

[0015] The beneficial technical effects of the present invention are as follows: Based on commands sent by the main control board and the door lock status, the door lock control board drives the door lock motor to perform corresponding actions and achieves relatively accurate positioning using limit switches and reset switches on the control board. The motor drive module precisely controls the forward and reverse rotation and braking actions of the door lock motor, ensuring the lock rod can accurately complete the extension and retraction movements, achieving reliable door opening and closing. The stall detection module monitors the operating current of the door lock motor in real time. When the current exceeds a preset threshold, a protection mechanism is triggered promptly, effectively preventing damage to the door lock motor due to stalling and extending its service life. Simultaneously, this protection mechanism also prevents the door from failing to open and close normally due to door lock motor stalling, improving the safety and reliability of household appliances. Attached Figure Description

[0016] Figure 1 This is a three-dimensional cross-sectional structural diagram of a door lock assembly according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the control flow of a door lock component according to an embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of the connection structure between the main control board and the door lock control device according to an embodiment of the present invention.

[0019] Figure 4 This is a schematic diagram of the chip structure of a door lock control board according to an embodiment of the present invention.

[0020] Figure 5 This is a schematic diagram of the structure of a motor drive module according to an embodiment of the present invention.

[0021] Figure 6 This is a schematic diagram of the travel detection module according to an embodiment of the present invention.

[0022] Figure 7 This is a schematic diagram of the main control board according to an embodiment of the present invention.

[0023] Figure 8 This is a schematic diagram of a self-locking circuit according to an embodiment of the present invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. In order to make the above-mentioned objects, features and advantages of this application more apparent and understandable, many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0025] See Figures 1-8 A household appliance door lock assembly based on single-wire communication includes a door lock control device that is communicatively connected to a main control board 1, and a door lock motor for driving the lock rod 3 to perform telescopic movements to open and close the door. The door lock control device includes a door lock control board 2, a motor drive module 4, and a stall detection module 7; The door lock control board 2 is used to receive door opening and closing commands sent by the main control board 1, and to receive door lock status signals from the main control board 1; The motor drive module 4 is electrically connected to the door lock control board 2 and is used to drive the door lock motor to perform forward rotation, reverse rotation or braking action according to the instructions of the door lock control board 2. The stall detection module 7 is electrically connected to the door lock control board 2 and is used to monitor the operating current of the door lock motor in real time. When the current exceeds a preset threshold, it sends a stall signal to the door lock control board 2, thereby triggering the door lock control board 2 to send a command to the motor drive module 4 to control the door lock motor to perform the protection mechanism action.

[0026] When the stall detection module 7 detects that the door lock motor has stalled a certain number of times in a row, it indicates that there may be an abnormality in the door lock, such as the door being stuck or the lock rod 3 being obstructed.

[0027] Based on the instructions sent by the main control board 1 and the door lock status, the door lock control board 2 drives the door lock motor to perform corresponding actions and achieves relatively accurate positioning according to the limit switch 9 and reset switch 10 on the door lock control board 2. The motor drive module 4 can precisely control the forward and reverse rotation and braking action of the door lock motor to ensure that the lock rod 3 can accurately complete the extension and retraction action, realizing the reliable opening and closing of the door. The stall detection module 7 monitors the operating current of the door lock motor in real time. When the current exceeds the preset threshold, the protection mechanism is triggered in time, which can effectively prevent the door lock motor from being damaged due to stalling and extend the service life of the motor. At the same time, this protection mechanism can also prevent the door from failing to open and close normally due to the stalling of the door lock motor, improving the safety and reliability of household appliances.

[0028] The door lock control device also includes a self-locking protection module 8 for providing mechanical locking function in case of abnormal door opening, and the self-locking protection module 8 is electrically connected to the door lock control board 2.

[0029] The self-locking protection module 8 includes a voltage limiting unit and a grounding switch unit; The positive power supply circuit of the door lock motor is electrically connected to the voltage limiting unit via the P04 pin of the door lock control board 2. The negative circuit of the door lock motor is electrically connected to the P10 pin of the door lock control board 2 and the grounding switch unit, respectively. When an abnormal door opening triggers the self-locking protection module 8, the P04 pin of the door lock control board 2 outputs a PWM signal, the P10 pin of the door lock control board 2 outputs a high level, and at the same time, the door lock control board 2 controls the motor drive module 4 to enter a high impedance state. The self-locking protection module 8 is designed to prevent the locking rod 3 from being abnormally pulled out. The self-locking circuit is activated when the door is closed and the reset switch 10 detects that the locking rod 3 has been pulled out. When the reset switch 10 detects the door being closed multiple times and the reset switch is open, the self-locking circuit is activated again after the required number of times. A small voltage of 0.7V is applied to the motor, but not enough to drive the door lock motor, so that the door lock motor has a certain locking force. Through the gear set, this makes it difficult for the locking rod 3 to be abnormally pulled out again. The voltage limiting unit includes a PMOS switch and an energy storage capacitor C2. When an abnormal door opening occurs, the door lock control board 2 outputs a PWM signal through the P04 pin to control the duty cycle of the PMOS switch and limit the positive voltage of the door lock motor. The grounding switch unit includes an NMOS transistor. When the P10 pin of the door lock control board 2 outputs a high level, the NMOS transistor is turned on, forcibly grounding the negative terminal of the door lock motor.

[0030] This invention provides a unique mechanical locking solution specifically for abnormal door opening scenarios by adding a self-locking protection module 8. When the door status detection module 6 detects that the door is in a closed state, if the locking rod 3 is pulled out by an abnormal external force, causing the reset switch 10 to disconnect, the system will execute the following protection mechanism: Automatic reset function: The door lock control board 2 immediately controls the motor drive module 4 through the P06 / P23 pins to make the lock rod 3 automatically retract to the reset position, ensuring that the door is restored to a safe closed state.

[0031] Cumulative anomaly detection: The system continuously monitors abnormal door opening events. When the cumulative number reaches a preset value (e.g., 3 times), it is determined that there is continuous human interference.

[0032] Mechanical locking activation: After triggering the self-locking protection module 8, the door lock control board 2 outputs a PWM signal through the P04 pin, controlling the PMOS switch to limit the positive voltage of the door lock motor to 0.7V (insufficient to drive the motor but capable of generating holding torque). The door lock control board 2 outputs a high level through the P10 pin, turning on the NMOS transistor to force the negative terminal of the motor to ground. The motor drive module 4 enters a high-impedance state, completely cutting off the drive signal. The self-locking protection module 8 is specifically designed to generate a static holding force through a 0.7V voltage trigger when the physical position is abnormal (reset switch is open), preventing manual opening and avoiding motor overheating. It works in conjunction with the door status detection module 6, activating only when the door is closed, avoiding erroneous self-locking state requiring manual reset, and ensuring that safety hazards are actively eliminated.

[0033] The stall detection module 7 includes a current sampling unit and a signal conversion unit; the current sampling unit is electrically connected to the motor drive module 4 and is used to convert the operating current of the door lock motor into a detection voltage. The input terminal of the signal conversion unit is electrically connected to the current sampling unit, and the output terminal of the signal conversion unit is electrically connected to the door lock control board 2. The current sampling unit is a first resistor, and the signal conversion unit is an analog-to-digital converter (ADC) built into the door lock control board 2. The voltage of the first resistor is detected and the current value is calculated through the P03 pin of the door lock control board 2. Alternatively, the current sampling unit is a second resistor, and the signal conversion unit includes an NMOS transistor. When the voltage of the second resistor exceeds the threshold voltage of the NMOS transistor, the NMOS transistor is turned on to pull the stall detection IO of the door lock control board 2 low to GND. When the stall detection module 7 continuously detects an abnormal current within a predetermined time, the door lock control board 2 executes the following protection command: The door lock control board 2 changes the H-bridge control level of the motor drive module 4 through pins P06 and P23, causing the door lock motor to run in reverse. When the locking lever 3 reaches the opposite position switch, the door lock control board 2 changes the level of pins P06 and P23 again, causing the door lock motor to return to its original direction of movement until it reaches the position switch in the original direction of movement of the locking lever 3. If the stall detection module 7 still detects an abnormal current during the process of the locking lever 3 returning to its original movement, the door lock control board 2 controls the door lock motor to run in reverse until the locking lever 3 reaches the safe position. Then, the door lock control board 2 outputs a brake level through pins P06 and P23, the door lock motor stops running, and the door lock control board 2 reports the stall information to the main control board 1.

[0034] If the stall detector continuously detects abnormal current within a predetermined time, it is determined that a stall has occurred. The door lock control board 2 executes the following corresponding instructions: The door lock control board 2 changes the voltage levels of pins P06 and P23, which are connected to the motor drive module 4, to cause the door lock motor to move in the opposite direction. When the locking lever 3 reaches the reverse position switch, the door lock control board 2 changes the voltage levels of pins P06 and P23 again to cause the door lock motor to return to its original movement until the locking lever 3 reaches the position switch in the original direction. If a blockage is still detected, the voltage levels of pins P06 and P23 are changed again to cause the door lock motor to move in the opposite direction. When the locking lever 3 reaches the reverse position switch, the door lock motor stops running. This blockage handling can address a series of safety issues such as hand trapping, door obstruction by heavy objects, gear jamming, and motor malfunction.

[0035] The door lock motor operating current is collected in real time by the stall detection module 7. When an abnormal current is detected, the door lock control board 2 controls the motor to perform a reverse action and tries the original action again after resetting. If stall is detected twice in a row, the door lock motor is stopped and the fault information is reported.

[0036] In this embodiment, the stall detection module 7 includes a 500mΩ sampling resistor (first resistor) connected in series with the power ground PGND of the motor drive module 4. The door lock control board 2 detects the voltage across the resistor using an ADC to calculate the operating current of the door lock motor.

[0037] In this embodiment, the motor drive module 4 uses the H-bridge driver chip MX500HC, and its IN1 / IN2 pins are connected to the P06 / P23 pins of the door lock control board 2, respectively.

[0038] Alternatively, the stall detection module 7 may also include an electronic switch circuit consisting of a 3Ω sampling resistor and an NMOS transistor. When the door lock motor stalls, the voltage at the upper end of the sampling resistor is greater than the NMOS turn-on voltage, and the NMOS transistor is turned on, pulling the stall detection IO of the door lock control board 2 low to GND. If a low level is detected for a certain period of time, it is determined that a stall has occurred.

[0039] The two specific implementations of the stall detection module 7 provide flexible current detection solutions for the door lock assembly, allowing for the selection of appropriate detection methods based on different application scenarios and requirements. The first solution uses a first resistor as the current sampling unit, combined with the analog-to-digital converter (ADC) built into the door lock control board 2. This accurately converts the operating current of the door lock motor into a digital signal for analysis and processing by the door lock control board 2. This solution offers high measurement accuracy, reflecting the motor's operating status in real time and providing reliable data support for stall detection. The second solution uses a signal conversion unit composed of a second resistor and an NMOS transistor. When the motor current is too high, causing the voltage across the second resistor to exceed the threshold voltage of the NMOS transistor, the NMOS transistor conducts, pulling the stall detection IO of the door lock control board 2 low to GND. This solution is simple in structure, low in cost, and has a fast response speed, enabling it to issue an alarm signal immediately upon the occurrence of a stall, allowing the door lock control board 2 to quickly take protective measures.

[0040] The door lock control device also includes a stroke detection module 5, which is electrically connected to the door lock control board 2 and is used to detect the stroke position of the lock rod 3. The travel detection module 5 includes a limit switch 9 and a reset switch 10. The limit switch 9 is electrically connected to the P11 pin of the door lock control board 2 and is used to detect the extended position of the lock rod 3. The reset switch 10 is electrically connected to the P05 pin of the door lock control board 2 and is used to detect the fully retracted position of the lock rod 3.

[0041] The travel detection module 5 enables the door lock assembly to accurately grasp the position information of the locking rod 3, thereby achieving precise control over the door opening and closing process. Limit switch 9 and reset switch 10 detect the extended and fully retracted positions of the locking rod 3, respectively, providing a clear position reference point for the door lock control board 2. When the locking rod 3 reaches the extended position, the door opens, and limit switch 9 sends a signal to pin P11 of the door lock control board 2. Upon receiving the signal, the door lock control board 2 controls the motor drive module 4 to perform a braking action, stopping the door lock motor and ensuring that the locking rod 3 accurately stops at the extended position, achieving reliable door locking. Similarly, when the locking rod 3 is fully retracted, reset switch 10 sends a signal to pin P05 of the door lock control board 2, and the door lock control board 2 controls the motor drive module 4 to stop working, stopping the locking rod 3 at the fully retracted position, achieving smooth door closing. The door lock motor's start and stop are precisely controlled according to the travel distance.

[0042] The door lock control device also includes a door status detection module 6, which is electrically connected to the main control board 1. The main control board 1 detects the opening and closing status of the door (detecting whether the door is closed or open) through the corresponding micro switch in the door status detection module 6, and feeds back the door status information to the door lock control board 2 through single-wire communication. The door lock control board 2 controls the motor drive module 4 to perform corresponding opening and closing actions based on the door status information and door opening and closing action commands fed back by the main control board 1. The door status detection module 6 includes a micro switch DoSW, one end of which is grounded and the other end of which is electrically connected to the DOOR detection port of the main control board 1. The main control board 1 detects high and low levels through the DOOR port to obtain the state of the micro switch DoSW.

[0043] The door status detection module 6 enables the main control board 1 to detect the opening and closing status of the door through the corresponding microswitch in the module 6. The main control board 1 feeds back the door status information to the door lock control board 2 via single-wire communication. The door lock control board 2 receives the information and controls the motor drive module 4 to perform corresponding opening and closing actions according to the closing action command. The microswitch DoSW, as the core component of the door status detection, generates corresponding signal changes based on the door's opening and closing status. When the door is closed, the microswitch DoSW is triggered, and the circuit between it and the DOOR detection port of the main control board 1 is connected, detecting a low-level signal at the DOOR port. When the door is open, the microswitch DoSW is reset, the circuit is disconnected, and the DOOR port detects a high-level signal. By detecting the high and low level changes at the DOOR port, the main control board 1 can accurately determine the opening and closing status of the door.

[0044] The main control board 1 and the door lock control board 2 are provided with a data port for single-line communication, and a timer 11 is provided between the main control board 1 and the door lock control board 2 for detecting the running time of the door lock motor driving the lock rod 3 during the opening and closing of the door. A timer 12 for generating periodic time base signals is also provided between the main control board 1 and the door lock control board 2, which triggers single-line communication between the main control board 1 and the door lock control board 2 in each time base period.

[0045] A control method for a household appliance door lock assembly based on single-wire communication as described above, wherein the door lock control device further includes a self-locking protection module 8, a travel detection module 5, and a door status detection module 6 electrically connected to the door lock control board 2; The control method for the household appliance door lock component based on single-wire communication includes the following control logic: The main control board 1 sends door opening and closing commands to the door lock control board 2 via a single-wire communication interface; Normal door opening and closing process: After parsing the command, the door lock control board 2 controls the motor drive module 4 to perform the corresponding movement through the P06 and P23 pins; the door lock control board 2 monitors the position of the lock rod 3 in real time through the stroke detection module 5; when the limit switch 9 or the reset switch 10 is triggered by the lock rod 3, the door lock control board 2 outputs a brake level through the P06 and P23 pins, and the door lock motor stops running; Stall protection control process: The stall detection module 7 monitors the door lock motor current in real time. When the door lock motor current continuously exceeds the threshold: When the first stall occurs, the door lock control board 2 controls the door lock motor to run in reverse through pins P06 and P23. When the locking lever 3 reaches the opposite position switch, the door lock motor resumes its original direction of movement until the locking lever 3 reaches the original position switch. If the door lock motor stalls again during the process of the locking lever 3 reaching the original position switch, the door lock control board 2 controls the door lock motor to run in reverse until the locking lever 3 reaches the safe position. After that, the door lock control board 2 outputs a brake level through pins P06 and P23, the door lock motor stops running, and the door lock control board 2 reports the stall information to the main control board 1. Self-locking protection control process: When the door status detection module 6 detects that the door is closed: if the reset switch 10 is abnormally disconnected a cumulative number of times, the door lock control board 2 controls the lock rod 3 to automatically reset through the door lock motor; the door lock control board 2 outputs a PWM signal through the P04 pin to limit the door lock motor voltage, and the door lock control board 2 outputs a high level through the P10 pin to turn on the grounding switch, controlling the motor drive module 4 to enter the high impedance state.

[0046] The timer 11 detects that the duration of the door lock motor driving the lock rod 3 during the door opening and closing process reaches a preset time value. After receiving the signal from the timer 11, the door lock control board 2 sends an instruction to the motor drive module 4 to control the door lock motor to stop running.

[0047] If the content of the single-line communication between the main control board 1 and the door lock control board 2 is disordered or unchanged within the corresponding set time value, the single-line communication between the main control board 1 and the door lock control board 2 is in a failed state. At this time, the door lock control board 2 automatically detects the reset switch 10. If the lock rod 3 does not reach the reset switch 10, the door closing logic is automatically started, the door lock motor rotates, and after the lock rod 3 reaches the reset switch 10, the door lock motor stops running.

[0048] During the abnormal door opening process, when the locking rod 3 is abnormally pulled out under the action of external force, the locking rod 3 disengages from the reset switch 10 of the stroke detection module 5. The door lock control board 2 sends a command to the motor drive module 4 to make the door lock motor drive the locking rod 3 to automatically retract back to its original position. After the locking rod 3 reaches the reset switch 10, the door lock motor stops operating and the number of abnormal door opening processes is accumulated. When the number of abnormal door opening attempts reaches the required number, the lock rod 3 returns to its reset state, triggering the self-locking protection module 8 to start the self-locking circuit. During the abnormal door closing process, the locking rod 3 is in the limited extension state and is disengaged from the door limit state when it is impacted by an external force. The locking rod 3 is disengaged from the limit switch 9 of the travel detection module 5. The door lock control board 2 sends a command to the motor drive module 4 to make the door lock motor drive the locking rod 3 to automatically retract back to the original position. After the locking rod 3 reaches the reset switch 10, the door lock motor stops operating.

[0049] In this embodiment, the input terminal of the stall detection module 7 is connected to the power ground PGND of the motor drive module 4, and the output terminal of the stall detection module 7 is connected to the ADC detection pin P03 of the door lock control board 2. It is used to monitor the motor operating current in real time and send a stall signal to the door lock control board 2 when the current exceeds the threshold.

[0050] In this embodiment, the control terminal of the motor drive module 4 is connected to the P06 and P23 pins of the door lock control board 2, and the power output terminal of the motor drive module 4 is connected to the door lock motor, which is used to drive the door lock motor to rotate forward, reverse or brake according to the instructions of the door lock control board 2.

[0051] In this embodiment, the household appliance is a dishwasher.

[0052] In this embodiment, the output shaft of the door lock motor is connected to the lock rod 3 via a gear, and the lock rod 3 is provided with a rack that meshes with the gear.

[0053] In this embodiment, the main control chip of the door lock control board 2 is the Chipbond 7208AS1A, which integrates a 12-bit high-precision ADC and allows for full-function remapping of I / O. P11 and P05 of the main control chip are remapped as input pins (with internal pull-up set to 10K), which can be used to detect the button status of the maximum / minimum travel of the locking lever 3. P06 and P23 of the main control chip are remapped as output pins, used to control the motor driver chip MX500HC to achieve forward / reverse rotation and stop of the door lock motor. P03 of the main control chip is remapped as an analog input, used for ADC detection of the operating voltage of the door opening / closing motor. Finally, P25 is configured as an input / output mode as a data port for single-wire communication with the main control board 1 of the dishwasher, and for single-wire communication with the PC10 port of the host chip SF309810U (the PC10 port is also configured as an input / output mode). The DoSW microswitch (door status detection module 6) is a normally open microswitch. When the latch is engaged, the microswitch closes, and the host chip SF309810U detects the high and low levels through the DOOR port to obtain the door open / close status.

[0054] The single-wire communication data port, timer 11, and timer 12 enable efficient and reliable communication and collaborative operation between the main control board 1 and the door lock control board 2. Single-wire communication simplifies wiring connections, reduces costs, and improves the system's anti-interference capability, ensuring the stability and accuracy of data transmission. Timer 11 detects the duration of the door lock motor driving the locking lever 3 during the door opening and closing process, providing a time reference for the door lock control board 2. By comparing the actual duration with a preset time value, the system can determine whether the door opening and closing process is normal. If the duration exceeds the preset time value, it may indicate door jamming or other abnormalities. In this case, the system can take timely measures, such as stopping the motor or issuing an alarm, to prevent damage to the door lock components and household appliances. Timer 12 generates a periodic time base signal, triggering single-wire communication between the main control board 1 and the door lock control board 2 within each time base cycle. This periodic communication mechanism ensures that the main control board 1 transmits door lock status and door opening / closing commands to the door lock control board 2.

[0055] In this embodiment, a timer is started, a time base of 125µs is configured, and single-line communication is performed every 10ms with a baud rate of 1000.

[0056] Normal door opening and closing logic: When the door is closed (DoSW button is pressed), the main control board 1 sends an opening command to the single-line communication port P25 of the door lock control board 2 according to the state of the DoSW button. After the door lock component receives the command, the P06 and P23 pins of the chip of the door lock control board 2 output corresponding high and low levels to drive the H-bridge of the MX500HC motor control chip, running the door lock motor to realize automatic door opening. After the lock rod reaches the limit switch MaSW (limit switch 9), the P11 pin of the chip of the door lock control board 2 is pulled low. When the P11 pin detects the low level after debouncing, P06 and P23 simultaneously output a high level to control the H-bridge of the MX500HC chip to realize the braking action and stop the door lock motor.

[0057] After the locking lever 3 reaches the limit position, the limit status is fed back to the main control board 1 via P25. The main control board 1 will start a timer upon receiving the limit information. When the corresponding time is reached, the main control board 1 will send a door closing command to the single-line communication port P25 of the door lock control board 2. After the door lock assembly receives the command, the P06 and P23 pins of the door lock control board 2 chip will output corresponding high and low levels to drive the H-bridge of the MX500HC motor control chip, running the door lock motor to achieve automatic door closing. After the locking lever reaches the reset switch MiSW (reset switch 10), the P05 pin of the door lock control board 2 chip is pulled low. When the P05 pin detects the low level after debouncing, P06 and P23 will simultaneously output a high level to control the H-bridge of the MX500HC chip to achieve braking action and stop the door lock motor (DC motor).

[0058] Handling abnormal door opening: When the locking lever 3 is abnormally pulled out (the motor stops, the door lock assembly is stationary, the H-bridge of the MX500HC chip is in a braking state, the locking lever 3 is manually pulled out, the reset switch MiSW is open, and the P05 pin of the door lock control board 2 chip is pulled high), the P06 and P23 of the door lock control board 2 chip output corresponding high and low levels to drive the H-bridge of the MX500HC motor control chip, run the door lock motor to realize automatic door closing, the locking lever 3 automatically retracts back to its original position, after the locking lever 3 reaches the reset switch MiSW, the P05 pin of the door lock control board 2 is pulled low. When the P05 pin detects the low level after debouncing, P06 and P23 simultaneously output a high level to control the H-bridge of the MX500HC chip to realize the braking action, stop the door lock motor, and increment the error counter.

[0059] When three errors are counted, the locking lever 3 returns to its reset state, activating the 0.7V self-locking circuit. Specifically, P10 outputs a high level to turn on the NMOS transistor in the self-locking protection module 8, grounding the motor's negative terminal. P04 outputs a PWM signal of the corresponding frequency to control the PMOS switching frequency, charging and discharging capacitor C2 until the average voltage reaches 0.7V, connected to the motor's positive terminal. Simultaneously, chips P06 and P23 on the door lock control board 2 output low levels to control the H-bridge of the MX500HC chip to enter a high-impedance state.

[0060] Handling abnormal door closures: (Accident prevention) When the locking lever 3 is in the limit extension state, an external force impacts the locking lever 3, causing it to disengage from the door limit state MaSW. The limit switch MaSW is then open, and the P11 pin of the door lock control board 2 is pulled high. P06 and P23 output corresponding high and low levels to drive the H-bridge of the MX500HC motor control chip, running the door lock motor to achieve automatic door closing. After the locking lever 3 reaches the reset switch MiSW, the P05 pin of the door lock control board 2 chip is pulled low. When the P05 pin detects the low level after debouncing, P06 and P23 simultaneously output high levels to control the H-bridge of the MX500HC chip to achieve braking action and stop the DC motor.

[0061] The door automatically closes to the reset state and returns a communication signal to the main control board 1 via P25.

[0062] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A door lock assembly for an electric household appliance based on single wire communication, characterized by: The door lock control device comprises a door lock control panel (2), a motor driving module (4), and a locked-rotor detection module (7). The door lock control panel (2) is configured to receive an opening / closing door instruction sent by the main control panel (1) and a door lock state signal sent by the main control panel (1). The motor driving module (4) is electrically connected to the door lock control panel (2) and is configured to drive the door lock motor to perform a forward rotation, a reverse rotation, or a brake action according to an instruction of the door lock control panel (2). The locked-rotor detection module (7) is electrically connected to the door lock control panel (2) and is configured to monitor a working current of the door lock motor in real time, and send a locked-rotor signal to the door lock control panel (2) when the current exceeds a preset threshold value, so as to trigger the door lock control panel (2) to send an instruction to the motor driving module (4) to control the door lock motor to perform a protection mechanism action. The door lock control device further comprises a self-locking protection module (8) configured to provide a mechanical locking function when an abnormal door opening occurs.

2. The door lock assembly for an electric home appliance based on single line communication according to claim 1, wherein: The self-locking protection module (8) comprises a voltage limiting unit and a grounding switch unit.

3. The door lock assembly for an appliance based on single-wire communication according to claim 1, characterized in that: A positive supply loop of the door lock motor and a P04 pin of the door lock control panel (2) are electrically connected to the voltage limiting unit, respectively. A negative loop of the door lock motor and a P10 pin of the door lock control panel (2) are electrically connected to the grounding switch unit, respectively. When the self-locking protection module (8) is triggered due to an abnormal door opening, the P04 pin of the door lock control panel (2) outputs a PWM signal, the P10 pin of the door lock control panel (2) outputs a high level, and the motor driving module (4) is controlled by the door lock control panel (2) to enter a high resistance state. The voltage limiting unit comprises a PMOS switch and an energy storage capacitor C2. The grounding switch unit comprises an NMOS tube. The locked-rotor detection module (7) comprises a current sampling unit and a signal conversion unit.

4. The door lock assembly for an appliance based on single-wire communication according to claim 1, characterized in that: The current sampling unit is electrically connected to the motor driving module (4) and is configured to convert the working current of the door lock motor into a detection voltage. The signal conversion unit is electrically connected to the current sampling unit at an input end and is electrically connected to the door lock control panel (2) at an output end. The current sampling unit is a first resistor, and the signal conversion unit is an analog-to-digital converter ADC built in the door lock control panel (2). Alternatively, the current sampling unit is a second resistor, and the signal conversion unit comprises an NMOS tube. When the voltage of the second resistor exceeds a threshold voltage of the NMOS tube, the NMOS tube is turned on to pull down a locked-rotor detection IO of the door lock control panel (2) to GND. When the stall detection module (7) continuously detects current abnormalities within a predetermined time, the door lock control board (2) executes the following protection instructions: The door lock control board (2) changes the H-bridge control level of the motor drive module (4) through the P06 pin and the P23 pin, so that the door lock motor runs in reverse. When the lock rod (3) reaches the opposite position switch, the door lock control board (2) changes the P06 and P23 pin levels again to make the door lock motor return to the original movement direction until it reaches the position switch in the original movement direction of the lock rod (3). If the lock rod (3) still detects current abnormalities during the recovery of the original movement, the door lock control board (2) controls the door lock motor to run in reverse until the lock rod (3) reaches the safe position. Then the door lock control board (2) outputs the brake level through the P06 and P23 pins, and the door lock motor stops running. The door lock control board (2) reports the stall information to the main control board (1).

5. The door lock assembly for an appliance based on single line communication according to claim 1, wherein: The door lock control device further comprises a stroke detection module (5) electrically connected with the door lock control board (2) and used for detecting the stroke position of the lock rod (3); The stroke detection module (5) comprises a limit switch (9) and a reset switch (10). The limit switch (9) is electrically connected with the P11 pin of the door lock control board (2) and used for detecting the extended position of the lock rod (3). The reset switch (10) is electrically connected with the P05 pin of the door lock control board (2) and used for detecting the fully retracted position of the lock rod (3).

6. The door lock assembly for an appliance based on single line communication according to claim 1, characterized in that: The door lock control device further comprises a door state detection module (6) electrically connected with the main control board (1). The main control board (1) detects the opening and closing state of the door body through the corresponding micro switch in the door state detection module (6) and feeds back the door body state information to the door lock control board (2) through single-wire communication. The door lock control board (2) controls the motor drive module (4) to make corresponding opening and closing actions according to the door body state information and the switch door action instruction fed back by the main control board (1). The door state detection module (6) comprises a micro switch DoSW. One end of the micro switch DoSW is grounded, and the other end of the micro switch DoSW is electrically connected with the DOOR detection port of the main control board (1). The main control board (1) detects the high and low levels through the DOOR port to obtain the state of the micro switch DoSW.

7. The door lock assembly for an appliance based on single line communication according to claim 1, characterized in that: The main control board (1) and the door lock control board (2) are provided with a data port for single-wire communication. The main control board (1) and the door lock control board (2) are provided with a timer (11) for detecting the running time of the door lock motor driving the lock rod (3) during the opening and closing process of the door body. The main control board (1) and the door lock control board (2) are further provided with a timer (12) for generating a periodic time base signal. The single-wire communication between the main control board (1) and the door lock control board (2) is triggered in each time base period.

8. A control method of the household appliance door lock assembly based on single-wire communication according to claim 7, characterized in that: The door lock control device further comprises a self-locking protection module (8), a stroke detection module (5), and a door state detection module (6) electrically connected with the door lock control board (2). The control method of the household appliance door lock assembly based on single-wire communication comprises the following control logic: The main control board (1) sends a door opening / closing instruction to the door lock control board (2) through a single-wire communication interface. Normal door opening / closing process: After the door lock control board (2) analyzes the instruction, the door lock control board (2) controls the motor drive module (4) to execute corresponding movement through the P06 and P23 pins; the door lock control board (2) monitors the position of the lock rod (3) in real time through the stroke detection module (5); when the limit switch (9) or the reset switch (10) is triggered by the lock rod (3), the door lock control board (2) outputs a brake level through the P06 and P23 pins, and the door lock motor stops running. Stall protection control process: the stall detection module (7) monitors the current of the door lock motor in real time; when the current of the door lock motor continuously exceeds a threshold value: First stall occurs, the door lock control board (2) controls the door lock motor to run in reverse through the P06 and P23 pins; when the lock rod (3) reaches the opposite position switch, the door lock motor resumes movement in the original direction until the lock rod (3) reaches the original direction position switch; if the lock rod (3) reaches the original direction position switch during the process, the door lock motor stalls again, the door lock control board (2) controls the door lock motor to run in reverse until the lock rod (3) reaches a safe position, the door lock control board (2) outputs a brake level through the P06 and P23 pins, and the door lock motor stops running; the door lock control board (2) reports the stall information to the main control board (1). Self-locking protection control process: when the door state detection module (6) detects that the door body is closed, if the cumulative number of abnormal disconnections of the reset switch (10) reaches N times, the door lock control board (2) controls the lock rod (3) to automatically reset through the door lock motor; the door lock control board (2) outputs a PWM signal through the P04 pin to limit the voltage of the door lock motor, and outputs a high level through the P10 pin to turn on the grounding switch, so that the motor drive module (4) enters a high resistance state.

9. The control method of the household appliance door lock assembly based on single-wire communication according to claim 8, wherein: The timer (11) detects that the running time of the door lock motor driving the lock rod (3) in the door body opening / closing process reaches a preset time value, and the door lock control board (2) sends an instruction to the motor drive module (4) to control the door lock motor to stop running after receiving the signal of the timer (11); If the content of the single-wire communication between the main control board (1) and the door lock control board (2) is disordered or does not change within the corresponding set time value, the single-wire communication between the main control board (1) and the door lock control board (2) is in a failure state; at this time, the door lock control board (2) detects the reset switch (10) autonomously; if the lock rod (3) does not reach the reset switch (10), the door lock motor rotates to drive the lock rod (3) to reach the reset switch (10), and then the door lock motor stops running.

10. The control method of the household appliance door lock assembly based on single-wire communication according to claim 8, wherein: In the abnormal door opening processing process, when the lock rod (3) is abnormally pulled out under the action of external force, the lock rod (3) is separated from the reset switch (10) of the stroke detection module (5), the door lock control board (2) sends an instruction to the motor drive module (4) to make the door lock motor drive the lock rod (3) to automatically retract and reset, and after the lock rod (3) reaches the reset switch (10), the door lock motor stops working and the number of abnormal door opening processing is accumulated; When the number of abnormal door opening processing reaches the corresponding number, after the lock rod (3) returns to the reset position, the self-locking protection module (8) is triggered to start the self-locking circuit; In the abnormal door closing processing process, when the lock rod (3) is in the limited extension state and is impacted by external force, it is separated from the limit switch (9) of the stroke detection module (5), the door lock control board (2) sends an instruction to the motor drive module (4) to make the door lock motor drive the lock rod (3) to automatically retract and reset, and after the lock rod (3) reaches the reset switch (10), the door lock motor stops working.

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