Ventilation fan

Abstract

This utility model discloses a ventilation fan, including a fan base and a fan top shell. The fan base has at least one first fastener on its side wall, and the fan top shell has at least one second fastener on its side wall. The fan top shell is adapted to and fastened to the fan base. The second fastener is adapted to and fastened to the first fastener. A stationary blade is located on the side of the fan top shell away from the fan base. An extension is located at one end between the fan top shell and the fan base, and an air outlet is located on the extension. A motor, a PCB board, and fan blades are located between the fan top shell and the fan base. The fan blades are connected to the motor and face the stationary blades. The PCB board is connected to the motor. This utility model has advantages such as precise fastening, reduced differential interference, and accurate control.

Description

Technical Field

[0001] This utility model belongs to the field of fan technology, specifically relating to a ventilation fan. Background Technology

[0002] Car seat ventilation fans are a type of ventilation fan primarily used to improve air circulation in the areas where the body contacts the seat, solving the problem of poor air circulation and difficulty in wicking away sweat caused by close contact. By actively driving air circulation, they remove sweat and heat, relieving stuffiness at its source. They can effectively dissipate the heat accumulated on the seat due to sun exposure, avoiding embarrassing situations like "burning buttocks," allowing occupants who have just entered a sun-exposed vehicle to sit down quickly. They can also work in conjunction with the car's air conditioning to lower the temperature of the areas where the body contacts the seat by 4-8°C, solving the problem of stuffiness where the air conditioning cannot reach the seat contact surface, making cooling more thorough.

[0003] Existing ventilation fans suffer from issues such as loose fastening and the generation of differential mode interference, which affects the accuracy of motor control and consequently interferes with the speed control of the ventilation fan. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a ventilation fan that features precise fastening, reduced differential interference, and accurate control.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] Ventilation fans, including:

[0007] The fan base housing has at least one first fastener on its side wall.

[0008] The fan top shell has at least one second fastener on its side wall. The fan top shell is adapted to the fan bottom shell and is fastened to the fan bottom shell. The second fastener is adapted to the first fastener and is fastened to the first fastener. The fan top shell has a stationary blade on the side away from the fan bottom shell. An extension is provided at one end between the fan top shell and the fan bottom shell. An air outlet is provided on the extension. A motor, a PCB board and a fan blade are provided between the fan top shell and the fan bottom shell. The fan blade is connected to the motor and is oriented towards the stationary blade. The PCB board is connected to the motor.

[0009] The PCB board is equipped with a driving circuit, which includes a power filter module, a pulse width signal filter module, and a motor drive module. The power filter module and the pulse width signal filter module are both connected to the motor drive module, and the motor drive module is connected to the motor. The power filter module is used to purify the power signal and ensure a stable power supply to the pulse width signal filter module and the motor drive module. The pulse width signal filter module is used to purify the PWM signal, and the motor drive module is used to drive and control the rotation of the motor.

[0010] Preferably, the power filter module includes a power supply, a transient suppression diode Z1, capacitors C1, C2, C3, C4, C5, and C6, a differential mode inductor L1, a diode D1, and an output VCC terminal. The positive terminal of the power supply is connected to the first terminal of the transient suppression diode Z1, the first terminal of capacitor C1, the first terminal of capacitor C2, and the first terminal of the differential mode inductor L1. The negative terminal of the power supply is connected to the second terminal of the transient suppression diode Z1, the second terminal of capacitor C1, and the second terminal of capacitor C2. The second terminal of the differential mode inductor L1 is connected to the first terminal of capacitor C3, the first terminal of capacitor C4, and the anode of diode D1. The cathode of diode D1 is connected to the first terminal of capacitor C5 and the first terminal of capacitor C6. The second terminals of capacitors C3, C4, C5, and C6 are all connected to the negative terminal of the power supply. The output VCC terminal is connected to the first terminal of capacitor C5 and the cathode of diode D1.

[0011] Preferably, the pulse width signal filter module includes a PWM signal input terminal, capacitors C10, C11, C12, and C13, a transient suppression diode Z2, a diode D2, resistors R1, R2, R3, and R4, and a MOSFET Q1. The PWM signal input terminal is connected to the first terminal of capacitor C11, the first terminal of transient suppression diode Z2, and the anode of diode D2, respectively. The second terminals of capacitor C11 and transient suppression diode Z2 are both grounded. The cathode of diode D2 is connected to the resistor R1. The first terminal is connected to the first terminal of resistor R3. The second terminal of resistor R1 is connected to the output VCC terminal. The second terminal of resistor R3 is connected to the gate of MOSFET Q1 and the first terminal of capacitor C13. The source of MOSFET Q1 is grounded. The drain of MOSFET Q1 is connected to the first terminal of resistor R2 and the first terminal of resistor R4. The second terminal of resistor R2 is connected to the output VCC terminal. The second terminal of resistor R4 is connected to the first terminal of capacitor C10 and the first terminal of capacitor C12. The second terminals of capacitor C10 and the second terminal of capacitor C12 are both grounded.

[0012] Preferably, the motor drive module includes a drive chip U1, an inductor L, a capacitor C7, and a capacitor C8. The motor terminal P1 is connected to the first terminal of capacitor C7 and the first terminal of inductor L, respectively. The second terminal of capacitor C7 is grounded. The motor terminal P2 is connected to the first terminal of capacitor C8 and the second terminal of inductor L, respectively. The second terminal of capacitor C8 is grounded. The second pin of drive chip U1 is connected to the cathode of diode D1. The first pin of drive chip U1 is connected to the second terminal of resistor R4. The fourth pin of drive chip U1 is connected to the motor terminal P1. The third pin of drive chip U1 is connected to the motor terminal P2.

[0013] By adopting the above technical solution, this utility model has the following beneficial effects:

[0014] (1) This utility model is provided with a first fastener and a second fastener, which are tightly fastened in specific applications;

[0015] (2) This utility model is provided with a power supply filter module and a pulse width signal filter module. In specific applications, the power supply filter module filters out differential mode interference on the power supply and suppresses transient voltage to ensure that the motor drive module works stably and reliably. The pulse width signal filter module filters out differential mode interference applied to the pulse width signal and suppresses transient voltage to ensure that the motor drive module works stably. This utility model reduces the influence of differential mode interference as a whole, and can achieve the purpose of precise control of the motor, with accurate and stable speed control.

[0016] In summary, this utility model has advantages such as precise fastening, reduced differential mode interference, and accurate control. Attached Figure Description

[0017] Figure 1 This is a structural schematic diagram of the ventilation fan of this utility model;

[0018] Figure 2 This is a block diagram of the driving circuit of this utility model;

[0019] Figure 3 This is a partial circuit diagram of the driving circuit of this utility model;

[0020] Figure 4 This is another part of the circuit schematic of the driving circuit of this utility model. Detailed Implementation

[0021] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0022] The components of the present invention embodiments described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0023] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] Example 1

[0027] In this embodiment, a ventilation fan is proposed, which has the functions of power supply voltage transient suppression and pulse width signal voltage transient suppression, and the overall control is precise.

[0028] like Figures 1-4 As shown, in one embodiment of the present invention, the ventilation fan of the present invention includes a fan bottom shell 1 and a fan top shell 3. The fan bottom shell 1 is provided with at least one first fastener 2 on its side wall, and the fan top shell 3 is provided with at least one second fastener 4 on its side wall. The fan top shell 3 is adapted to the fan bottom shell 1 and is fastened to the fan bottom shell 1. The second fastener 4 is adapted to the first fastener 2 and is fastened to the first fastener 2. The fan top shell 3 is provided with a stationary blade 5 on the side away from the fan bottom shell 1. An extension is provided at one end between the fan top shell 3 and the fan bottom shell 1. An air outlet is provided on the extension. A motor, a PCB board and a fan blade are provided between the fan top shell 3 and the fan bottom shell 1. The fan blade is connected to the motor and is positioned towards the stationary blade 5. The PCB board is connected to the motor.

[0029] To achieve precise control and reduce the impact of differential mode interference, the PCB board of this utility model is equipped with a driving circuit. The driving circuit includes a power filter module, a pulse width signal filter module, and a motor drive module. The power filter module and the pulse width signal filter module are both connected to the motor drive module, and the motor drive module is connected to the motor. The power filter module is used to purify the power signal and ensure a stable power supply to the pulse width signal filter module and the motor drive module. The pulse width signal filter module is used to purify the PWM signal, and the motor drive module is used to drive and control the rotation of the motor.

[0030] The core function of the power filter module is to bidirectionally purify the power signal, ensuring a stable power supply to downstream circuits (such as the motor drive module and the pulse width signal filter module). It has the effects of resisting external interference, preventing internal interference leakage, and ensuring power purity. Specifically, the power filter module of this utility model can prevent high-frequency interference, harmonics, surges, etc. from entering the utility model, avoiding interference that affects the stability of the motor drive module and the pulse width signal filter module. It can also suppress electromagnetic interference generated inside the utility model, preventing it from being conducted to the power supply through the power line and avoiding interference with other electrical appliances. It can also allow useful power signals such as DC or power frequency (such as 50Hz) to pass smoothly, providing "stable and noise-free" power to modules such as the motor drive module and the pulse width signal filter module, thereby improving the reliability and lifespan of the utility model.

[0031] The pulse width modulation (PWM) signal is the core command for controlling the motor speed / direction. Therefore, the function of the PWM signal filter module is to purify the PWM signal. Specifically, the PWM signal filter module can filter out high-frequency noise and interference in the PWM signal (such as attenuating the high-frequency components of interference through low-pass filtering characteristics), ensuring that the duty cycle, frequency, amplitude and other parameters of the PWM signal are accurate and stable. This allows the motor drive module to receive control commands "without error", thereby accurately adjusting the motor speed, power output, etc., and improving the system control accuracy.

[0032] This utility model's motor drive module acts as a bridge between the "control command (pulse width signal filter module)" and the "motor." Its core function is to convert electrical signals into the mechanical power of the motor. It receives commands (PWM, direction signals, etc.) from an external controller (such as an MCU) and converts them into the current and voltage required by the motor. It can also precisely control the motor's speed, direction, acceleration, and deceleration to meet the needs of different scenarios (such as "multi-speed adjustment" in car seat ventilation). It can also integrate overcurrent, overheat, and undervoltage protection mechanisms to prevent the motor from being damaged due to abnormal operating conditions (overload, voltage surge) and ensure long-term stable operation. The power filter module, pulse width signal filter module, and motor drive module form a collaborative chain of "clean power supply → accurate signal → controllable motor," which together ensures the stable and efficient operation of the ventilation fan (such as in car seat ventilation systems).

[0033] The power filter module of this utility model includes a power supply, a transient suppression diode Z1, capacitors C1, C2, C3, C4, C5, and C6, a differential mode inductor L1, a diode D1, and an output VCC terminal. The positive terminal of the power supply is connected to the first terminal of the transient suppression diode Z1, the first terminal of capacitor C1, the first terminal of capacitor C2, and the first terminal of the differential mode inductor L1. The negative terminal of the power supply is connected to the second terminal of the transient suppression diode Z1, the second terminal of capacitor C1, and the second terminal of capacitor C2. The second terminal of the differential mode inductor L1 is connected to the first terminal of capacitor C3, the first terminal of capacitor C4, and the anode of diode D1. The cathode of diode D1 is connected to the first terminal of capacitor C5 and the first terminal of capacitor C6. The second terminals of capacitors C3, C4, C5, and C6 are all connected to the negative terminal of the power supply. The output VCC terminal is connected to the first terminal of capacitor C5 and the cathode of diode D1.

[0034] Specifically, when a surge / transient high voltage occurs in the power supply, the transient suppression diode Z1 of this invention will quickly break down and "clamp" the voltage, keeping the voltage of the subsequent circuit within a safe range. Capacitors C1, C2, C3, C4, and differential mode inductor L1 form a differential mode filter. Differential mode interference is an interference signal between power lines. The capacitors (C1, C2, C3, and C4) provide a low-impedance path for the interference, while the inductor (differential mode inductor L1) impedes the change of interference current, thereby filtering out differential mode interference on the power lines. If the positive and negative terminals of the external power supply are reversed, diode D1 will be "cut off" due to reverse bias, cutting off the power supply circuit of the subsequent circuit and preventing the motor drive module and other components from being burned out due to reverse connection.

[0035] The pulse width signal filter module includes a PWM signal input terminal, capacitors C10, C11, C12, and C13, transient suppression diode Z2, diode D2, resistors R1, R2, R3, and R4, and MOSFET Q1. The PWM signal input terminal is connected to the first terminal of capacitor C11, the first terminal of transient suppression diode Z2, and the anode of diode D2. The second terminals of capacitor C11 and transient suppression diode Z2 are both grounded. The cathode of diode D2 is connected to the first terminals of resistors R1 and R3. The second terminal of resistor R1 is connected to the output VCC terminal. The second terminal of resistor R3 is connected to the gate (G) of MOSFET Q1 and the first terminal of capacitor C13. The source (S) of MOSFET Q1 is grounded. The drain (D) of MOSFET Q1 is connected to the first terminals of resistors R2 and R4. The second terminal of resistor R2 is connected to the output VCC terminal. The second terminal of resistor R4 is connected to the first terminals of capacitors C10 and C12. The second terminals of capacitors C10 and C12 are both grounded.

[0036] Specifically, capacitor C11 (filter capacitor) and transient suppression diode Z2 first perform "preliminary purification" on the input PWM signal—transient suppression diode Z2 clamps the transient high voltage of the PWM signal, capacitor C11 filters out high-frequency noise at the input terminal of the PWM signal, diode D2, resistor R1, and resistor R3 form the gate drive circuit of MOSFET Q1, and the output VCC terminal provides bias voltage to the gate of MOSFET Q1 through resistor R1 and diode D2, resistor R3 limits the gate current, MOSFET Q1 acts as a switching / amplifying element to "shape" the PWM signal (making the signal amplitude and waveform more stable), capacitor C13 is the filter capacitor from the gate to ground, further filtering out gate interference, resistor R4 (current limiting / voltage dividing), capacitor C10, and capacitor C12 (filter capacitor) form an RC low-pass filter, which filters the signal output from the drain of MOSFET Q1 again, and finally outputs a "clean" SPEED signal to the motor drive, ensuring that the PWM signal received by the motor drive is free of differential mode interference and transiently stable.

[0037] The motor drive module includes a drive chip U1, an inductor L, a capacitor C7, and a capacitor C8. The motor terminal P1 is connected to the first terminal of capacitor C7 and the first terminal of inductor L, respectively. The second terminal of capacitor C7 is grounded. The motor terminal P2 is connected to the first terminal of capacitor C8 and the second terminal of inductor L, respectively. The second terminal of capacitor C8 is grounded. The second pin of drive chip U1 is connected to the cathode of diode D1. The first pin of drive chip U1 is connected to the second terminal of resistor R4. The fourth pin of drive chip U1 is connected to the motor terminal P1. The third pin of drive chip U1 is connected to the motor terminal P2.

[0038] Specifically, the driver chip U1 controls the motor speed based on the PWM signal input from the SPEED pin (first pin). When the motor is working, it will generate electromagnetic interference. The inductor L and capacitors C7 and C8 (providing a ground path for interference) form a filter network to filter out the motor's own interference signals, while stabilizing the motor's power supply / signal and reducing the impact on the overall electromagnetic environment. The entire circuit adopts a multi-layer design of "power supply filtering + signal filtering + motor side filtering", combined with "transient suppression + reverse connection protection", which not only meets the differential mode interference requirements, but also ensures the stability and reliability of the ventilation fan.

[0039] The power filter module of this invention filters out differential-mode interference applied to the power supply and absorbs transient voltage through transient suppression diode Z1, clamping the voltage within the safe voltage range of the motor drive module. Diode D1 is used as reverse connection protection to prevent the positive and negative terminals from being reversed and burning out the motor drive module. The pulse width signal filter module filters out differential-mode interference applied to the pulse width signal (capacitors C10 / C11 / C12 / C13 / MOSQ1 work together) and absorbs transient voltage through transient suppression diode Z2, clamping the voltage within the safe voltage range that the pulse width signal input pin of the motor drive module can withstand.

[0040] This embodiment does not impose any limitation on the shape, material, structure, etc. of this utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this utility model shall fall within the protection scope of this utility model.

Claims

1. A ventilating fan characterised in that, include: The fan base housing has at least one first fastener on its side wall. The fan top shell has at least one second fastener on its side wall. The fan top shell is adapted to the fan bottom shell and is fastened to the fan bottom shell. The second fastener is adapted to the first fastener and is fastened to the first fastener. The fan top shell has a stationary blade on the side away from the fan bottom shell. An extension is provided at one end between the fan top shell and the fan bottom shell. An air outlet is provided on the extension. A motor, a PCB board and a fan blade are provided between the fan top shell and the fan bottom shell. The fan blade is connected to the motor and is oriented towards the stationary blade. The PCB board is connected to the motor. The PCB board is equipped with a driving circuit, which includes a power filter module, a pulse width signal filter module, and a motor drive module. The power filter module and the pulse width signal filter module are both connected to the motor drive module, and the motor drive module is connected to the motor. The power filter module is used to purify the power signal and ensure a stable power supply to the pulse width signal filter module and the motor drive module. The pulse width signal filter module is used to purify the PWM signal, and the motor drive module is used to drive and control the rotation of the motor.

2. The ventilating fan of claim 1, wherein: The power filter module includes a power supply, a transient suppression diode Z1, capacitors C1, C2, C3, C4, C5, and C6, a differential mode inductor L1, a diode D1, and an output VCC terminal. The positive terminal of the power supply is connected to the first terminal of the transient suppression diode Z1, the first terminal of capacitor C1, the first terminal of capacitor C2, and the first terminal of the differential mode inductor L1. The negative terminal of the power supply is connected to the second terminal of the transient suppression diode Z1, the second terminal of capacitor C1, and the second terminal of capacitor C2. The second terminal of the differential mode inductor L1 is connected to the first terminal of capacitor C3, the first terminal of capacitor C4, and the anode of diode D1. The cathode of diode D1 is connected to the first terminal of capacitor C5 and the first terminal of capacitor C6. The second terminals of capacitors C3, C4, C5, and C6 are all connected to the negative terminal of the power supply. The output VCC terminal is connected to the first terminal of capacitor C5 and the cathode of diode D1.

3. The ventilating fan of claim 2, wherein: The pulse width signal filter module includes a PWM signal input terminal, capacitors C10, C11, C12, and C13, transient suppression diode Z2, diode D2, resistors R1, R2, R3, and R4, and MOSFET Q1. The PWM signal input terminal is connected to the first terminal of capacitor C11, the first terminal of transient suppression diode Z2, and the anode of diode D2. The second terminals of capacitor C11 and transient suppression diode Z2 are both grounded. The cathode of diode D2 is connected to the first terminals of resistors R1 and R3. The second terminal of resistor R1 is connected to the output VCC terminal. The second terminal of resistor R3 is connected to the gate (G) of MOSFET Q1 and the first terminal of capacitor C13. The source (S) of MOSFET Q1 is grounded. The drain (D) of MOSFET Q1 is connected to the first terminals of resistors R2 and R4. The second terminal of resistor R2 is connected to the output VCC terminal. The second terminal of resistor R4 is connected to the first terminals of capacitors C10 and C12. The second terminals of capacitors C10 and C12 are both grounded.

4. The ventilating fan of claim 3, wherein: The motor drive module includes a drive chip U1, an inductor L, a capacitor C7, and a capacitor C8. The motor terminal P1 is connected to the first terminal of capacitor C7 and the first terminal of inductor L, respectively. The second terminal of capacitor C7 is grounded. The motor terminal P2 is connected to the first terminal of capacitor C8 and the second terminal of inductor L, respectively. The second terminal of capacitor C8 is grounded. The second pin of drive chip U1 is connected to the cathode of diode D1. The first pin of drive chip U1 is connected to the second terminal of resistor R4. The fourth pin of drive chip U1 is connected to the motor terminal P1. The third pin of drive chip U1 is connected to the motor terminal P2.

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