Wireless monitoring device

Abstract

The invention discloses a wireless monitoring device which comprises a plurality of wireless monitors with different frequency modulation frequencies, and each wireless monitor comprises an acquisition module, a signal conditioning module, a frequency modulation wireless sending module, a main control module and a power supply module. The acquisition module is used for acquiring vibration and / or sound to obtain a first signal; the signal conditioning module is connected with the acquisition module and is used for carrying out filtering conditioning and power amplification on the first signal to obtain a second signal; the frequency modulation wireless sending module is connected with the signal conditioning module and is used for wirelessly sending the second signal in a frequency modulation mode; the main control module is connected with the frequency modulation wireless sending module and used for controlling the frequency modulation frequency; and the power supply module is used for providing electric energy for equipment on the wireless monitor. According to the invention, the vibration and / or sound at different positions of the vehicle chassis are acquired through the plurality of wireless monitors with different frequency modulation frequencies, and are provided for a user in a wireless frequency modulation manner, so that the user can judge the condition of vehicle parts in the driving process of the vehicle conveniently.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle detection, and particularly relates to a wireless monitoring device. Background Art

[0002] When abnormal noises occur in the chassis during the driving of a vehicle, it is a problem that many vehicle owners will encounter. The abnormal noises in the chassis may indicate that the vehicle may have a fault. However, when the vehicle is driving, the vehicle owner can only feel the abnormal noises but it is difficult to accurately locate the position where the abnormal noises occur, which will bring inconvenience to the vehicle maintenance.

[0003] In view of this, a new device is needed to solve the above problems. Summary of the Invention

[0004] To solve the problems commonly existing in the prior art, an embodiment of a wireless monitoring device is proposed in the present invention. A plurality of wireless monitors with different FM frequencies are used to collect vibrations and / or sounds at different positions of the vehicle chassis, and are provided to the user in a wireless FM manner, so as to facilitate the user to judge the condition of vehicle components during vehicle driving.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A wireless monitoring device includes a plurality of wireless monitors with different FM frequencies. Each wireless monitor includes an acquisition module, a signal conditioning module, a FM wireless transmission module, a main control module, and a power module; the acquisition module is used to collect vibrations and / or sounds to obtain a first signal; the signal conditioning module is connected to the acquisition module and is used to filter, condition, and power-amplify the first signal to obtain a second signal; the FM wireless transmission module is connected to the signal conditioning module and is used to wirelessly transmit the second signal in an FM manner; the main control module is connected to the FM wireless transmission module and is used to control the FM frequency; the power module is used to provide electrical energy for the devices on the wireless monitor.

[0007] Further, the acquisition module includes a piezoelectric ceramic vibration sensor, and the first signal is obtained through the piezoelectric ceramic vibration sensor.

[0008] Further, the signal conditioning module includes a filter amplification unit and an audio power amplification unit; the filter amplification unit is used to filter and amplify the first signal collected by the acquisition module; the audio power amplification unit is connected to the main control module and the filter amplification unit, and the audio power amplification unit is used to receive the enabling signal of the main control module and the output signal of the filter amplification unit, and when receiving the enabling signal of the main control module, power-amplify the output signal of the filter amplification unit to obtain a second signal in the form of a dual-channel audio signal.

[0009] Further, the wireless listener further includes a communication module, which is connected to the main control module and is used to receive the setting information of the FM frequency.

[0010] Further, the communication module includes a USB interface and a USB / serial port conversion chip.

[0011] Further, it further includes an upper shell and a lower shell. A circuit board is provided between the upper shell and the lower shell. The acquisition module, the signal conditioning module, the FM wireless transmission module and the main control module are all arranged on the circuit board.

[0012] Further, the acquisition module includes a cap-shaped shell, a metal plate and a piezoelectric ceramic. A through hole is provided in the middle of the cap-shaped shell. The metal plate is fixedly arranged inside the cap-shaped shell, and the piezoelectric ceramic is fixedly arranged below the metal plate; a sensor mounting bracket is provided on the circuit board, and the sensor mounting bracket supports the outer edge of the cap-shaped shell. A sensor mounting hole is provided on the upper shell, and the top of the cap-shaped shell is exposed from the sensor mounting hole.

[0013] Further, the wireless listener further includes an indicator light, a key switch and a key. The indicator light and the key switch are both arranged on the circuit board, and the indicator light and the key switch are both connected to the main control module; the light emitted by the indicator light penetrates from the back of the lower shell, and the key is arranged in the key mounting hole of the lower shell, and the key switch is triggered by pressing the key.

[0014] Further, the power supply module includes a battery, and the battery is arranged in the battery compartment of the lower shell.

[0015] Further, two supports are provided on each side of the lower shell, and mounting posts are provided between the two supports on each side. A gap is formed between the mounting posts and the side surface of the lower shell.

[0016] The beneficial effects of the present invention are as follows:

[0017] The present invention provides a wireless monitoring device. A user can set a plurality of wireless listeners with different FM frequencies at different positions on the vehicle chassis. The wireless listeners can collect vibrations and / or sounds at different positions on the vehicle chassis. When the vehicle is running, the user can select different FM frequencies through a FM radio to listen to the vibrations and / or sounds collected by the wireless listeners at different positions on the vehicle chassis, and then judge the condition of vehicle components. Description of the Drawings

[0018] Figure 1 is a communication schematic diagram of the wireless monitoring device of the present invention and a FM radio;

[0019] Figure 2It is the electrical principle block diagram of the wireless monitor of the present invention;

[0020] Figure 3 It is the circuit schematic diagram of the signal conditioning module of the present invention;

[0021] Figure 4 It is the circuit schematic diagram of the FM wireless transmission module of the present invention;

[0022] Figure 5 It is the circuit schematic diagram of the communication module of the present invention;

[0023] Figure 6 It is another electrical principle block diagram of the wireless monitor of the present invention;

[0024] Figure 7 It is the front structure schematic diagram of the wireless monitor of the present invention;

[0025] Figure 8 It is the back structure schematic diagram of the wireless monitor of the present invention;

[0026] Figure 9 It is the partial structure decomposition schematic diagram of the wireless monitor of the present invention;

[0027] Figure 10 It is the partial structure decomposition schematic diagram of the wireless monitor of the present invention;

[0028] Figure 11 It is the cross-sectional structure schematic diagram of the acquisition module of the present invention;

[0029] Figure 12 It is the circuit schematic diagram of the power supply module of the present invention.

[0030] In the figure:

[0031] 100 - Wireless monitor; 110 - Acquisition module; 111 - Cap-shaped housing; 1111 - Through hole; 112 - Metal plate; 113 - Piezoelectric ceramic; 120 - Signal conditioning module; 121 - Filtering and amplifying unit; 122 - Audio power amplifying unit; 130 - FM wireless transmission module; 140 - Main control module; 150 - Power supply module; 151 - Voltage conversion module; 160 - Communication module; 170 - Upper housing; 171 - Mounting hole; 180 - Lower housing; 181 - Button mounting hole; 182 - Light-transmitting hole; 183 - Battery compartment; 184 - Battery compartment cover; 185 - Support; 186 - Mounting post; 187 - Gap; 188 - Antenna accommodating part; 190 - Circuit board; 191 - Sensor mounting bracket; 192 - Indicator light; 193 - Button switch; 194 - Button; 200 - FM radio. Detailed implementation manners

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0033] The terms "first", "second", and "third" in the present application are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity or order of the indicated technical features. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship or movement situation between components in a specific posture (as shown in the accompanying drawings); it should be noted that when a component is referred to as "fixed to", "disposed on", or "connected to" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component, or there may be one or more intermediate components therebetween. The terms "vertical", "horizontal", "left", "right", and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manner.

[0034] As Figure 1 and Figure 2 shown, to solve the problems commonly existing in the prior art, an embodiment of a wireless monitoring device is proposed in the present invention, which includes a plurality of wireless monitors 100 with different FM frequencies. Each wireless monitor includes an acquisition module 110, a signal conditioning module 120, an FM wireless transmission module 130, a main control module 140, and a power supply module 150. The acquisition module 110 is used to acquire vibrations and / or sounds to obtain a first signal; the signal conditioning module 120 is connected to the acquisition module and is used to filter, condition, and power-amplify the first signal to obtain a second signal; the FM wireless transmission module 130 is connected to the signal conditioning module 120 and is used to wirelessly transmit the second signal in an FM manner; the main control module 140 is connected to the FM wireless transmission module 130 and is used to control the FM frequency; the power supply module 150 is used to provide electrical energy for the devices on the wireless monitor 100.

[0035] The working principle of the present invention is as follows: A plurality of wireless monitors 100 with different FM frequencies can be arranged at different positions on the vehicle chassis. Through the wireless monitors 100, vibrations and / or sounds at different positions on the vehicle chassis can be acquired. When the vehicle is in motion, the user can select different FM frequencies through the FM radio 200 to listen to the vibrations and / or sounds collected by the wireless monitors 100 at different positions on the vehicle chassis, and then judge the condition of the vehicle components.

[0036] In some embodiments, the acquisition module 110 includes a piezoelectric ceramic vibration sensor, and a first signal is obtained through the piezoelectric ceramic vibration sensor.

[0037] In some embodiments, referring to Figure 3 , the signal conditioning module 120 includes a filter amplification unit 121 and an audio power amplification unit 122; the filter amplification unit 121 is configured to filter and amplify the first signal collected by the acquisition module 110; the audio power amplification unit 122 is connected to the main control module 140 and the filter amplification unit 121, and the audio power amplification unit 122 is configured to receive the enabling signal of the main control module 140 and the output signal of the filter amplification unit 121, and perform power amplification on the output signal of the filter amplification unit 121 when receiving the enabling signal of the main control module 140 to obtain a second signal in the form of a dual-channel audio signal.

[0038] In a specific implementation manner, referring to Figure 3, the filtering and amplifying unit 121 includes an operational amplifier U3A, resistors R8, R9, R13, R14, R15, R16, R17, capacitors C3, C8, C9, and C10. The first signal obtained by the acquisition module 110 is connected to the S+ terminal. The S+ terminal is connected to the positive input terminal of the operational amplifier U3A through the series-connected resistors R14 and R15. The S+ terminal is connected to the negative input terminal of the operational amplifier U3A through the series-connected resistor R13 and capacitor C9. The S+ terminal is grounded through the resistor R16. The positive input terminal of the operational amplifier U3A is grounded through the parallel-connected resistors R17 and capacitor C10. The negative input terminal of the operational amplifier U3A is connected to the output terminal of the operational amplifier U3A through the series-connected resistors R8 and R9, and both ends of the resistor R9 are connected in parallel with C3. The output terminal of the operational amplifier U3A is connected to the S_IN terminal through the capacitor C8. The S_IN terminal serves as the output terminal of the filtering and amplifying unit 121 and the input terminal of the audio power amplifying unit 122. The audio power amplifying unit 122 includes an audio power amplifier chip U2, resistors R1, R7, R10, R12, capacitors C4, and C7. The S_IN terminal is connected to the first input pin VIN1 of the audio power amplifier chip U2 through the series-connected capacitor C4 and resistor R7. The first input pin VIN1 of the audio power amplifier chip U2 is connected to the first output pin VOUT1 of the audio power amplifier chip U2 through the resistor R1. The first output pin VOUT1 of the audio power amplifier chip U2 serves as the right channel output terminal AR. The S_IN terminal is connected to the second input pin VIN2 of the audio power amplifier chip U2 through the series-connected capacitor C7 and resistor R12. The second input pin VIN2 of the audio power amplifier chip U2 is connected to the second output pin VOUT2 of the audio power amplifier chip U2 through the resistor R10. The second output pin VOUT2 of the audio power amplifier chip U2 serves as the left channel output terminal AL. The bypass pin Bypass of the audio power amplifier chip U2 is grounded through the capacitor C6. The start / stop pin SHUTDOWN# of the audio power amplifier chip U2 is connected to the audio power amplifier start / stop control terminal SHUTDOWN of the main control module 140. The main control module 140 can control the enabling and disabling of the audio power amplifier chip U2. The model of the audio power amplifier chip U2 can be LPA4809. The second signal in the form of a dual-channel audio signal can be obtained from the right channel output terminal AR and the left channel output terminal AL.

[0039] In a specific embodiment, refer to Figure 4, the FM wireless transmission module 130 includes an FM wireless transmission chip U1, a crystal oscillator Y1, a switching transistor Q5, a resistor R2, a resistor R11, a resistor R26, a capacitor C1, a capacitor C2, a capacitor C5, a capacitor C21, an inductor L1, and an inductor L3. The left-channel output terminal AR is connected to the left-channel input pin ALI of the FM wireless transmission chip U1 through the capacitor C1, and the right-channel output terminal AR is connected to the right-channel input pin ARI of the FM wireless transmission chip U1 through the capacitor C2. The output terminal TXAL1 of the crystal oscillator Y1 is connected to the first crystal oscillator pin TXAL1 of the FM wireless transmission chip U1. The IO voltage pin VIO of the FM wireless transmission chip U1 is connected to the 3.3V power supply; the serial data pin SDA of the FM wireless transmission chip U1 is connected to the serial data terminal SDA of the main control module 140 and is also connected to the 3.3V power supply through the resistor R2; the serial clock pin SCA of the FM wireless transmission chip U1 is connected to the serial clock terminal SCA of the main control module 140 and is also connected to the 3.3V power supply through the resistor R11; the RF output pin RFO of the FM wireless transmission chip U1 is grounded through the inductor L1 and is connected to the base of the switching transistor Q5 through the capacitor C5; the resistor R26 is connected in parallel between the base and the collector of the switching transistor Q5. The emitter of the switching transistor Q5 is grounded. The collector of the switching transistor Q5 is connected to the antenna ANT through the capacitor C22, and the collector of the switching transistor Q5 is also connected to the 3.3V power supply through the parallel-connected capacitor C21 and inductor L3. The model of the FM wireless transmission chip U1 can be QN8027. The main control module 140 can communicate with the FM wireless transmission chip U1 through the serial data terminal SDA and the serial clock terminal SCA to set the FM frequency and transmission status of the FM wireless transmission chip U1, etc.

[0040] In a specific implementation, the main control module 140 can adopt a microprocessor. For example, the model is STC8H1K08.

[0041] In some embodiments, refer to Figure 5 , the wireless monitor 100 further includes a communication module 160. The communication module 160 is connected to the main control module 140 and is used to receive the setting information of the FM frequency.

[0042] In a specific implementation, the wireless monitor 100 can communicate with the host computer through the communication module 160 to set its own FM frequency.

[0043] In some embodiments, refer to Figure 6 , the communication module 160 includes a USB interface USB1 and a USB bus transfer chip U13. The serial data transmission terminal TXD and the serial data reception terminal RXD of the main control module 140 are connected to the USB bus transfer chip U13. The USB bus transfer chip U13 can realize the mutual conversion between USB and serial port. The USB bus transfer chip U13 is connected to the USB interface USB1. The USB interface USB1 adopts a TYPEC interface.

[0044] In some embodiments, referring to Figures 7 to 10 , the wireless listener 100 further includes an upper housing 170 and a lower housing 180. A circuit board 190 is provided between the upper housing 170 and the lower housing 180. The acquisition module 110, the signal conditioning module 120, the FM wireless transmission module 130, and the main control module 140 are all arranged on the circuit board 190.

[0045] In some embodiments, referring to Figure 11 , the acquisition module 110 includes a cap-shaped housing 111, a metal plate 112, and a piezoelectric ceramic 113. A through hole 1111 is provided in the middle of the cap-shaped housing 111. The metal plate 112 is fixedly arranged inside the cap-shaped housing 111, and the piezoelectric ceramic 113 is fixedly arranged below the metal plate 112. The circuit board 190 is provided with a sensor mounting bracket 191. The sensor mounting bracket 191 supports the outer edge of the cap-shaped housing 111. The upper housing 170 is provided with a sensor mounting hole 171, and the top of the cap-shaped housing 111 is exposed from the sensor mounting hole 171. The piezoelectric ceramic 113 arranged below the metal plate 112 can sense sound and / or vibration, generate induced charges on the surface based on the piezoelectric effect, and signal lines can be respectively arranged on the lower surfaces of the metal plate 112 and the piezoelectric ceramic 113 to obtain the induced signal. The arrangement of the sensor mounting hole 171 on the upper housing 170 and the through hole 1111 of the cap-shaped housing 111 facilitates the piezoelectric ceramic 113 to sense external sound, and the metal plate 112 can also play a certain protective role. The sensor mounting bracket 191 of the circuit board 190 can be annular, and the metal plate 112 and the piezoelectric ceramic 113 are arranged between the sensor mounting bracket 191 and the cap-shaped housing 111 to facilitate vibration sensing.

[0046] In some embodiments, referring to Figures 7 to 10 , the wireless listener 100 further includes an indicator light 192, a key switch 193, and a key 194. The indicator light 192 and the key switch 193 are both arranged on the circuit board 190, and the indicator light 192 and the key switch 193 are both connected to the main control module 140. The light emitted by the indicator light 192 penetrates from the back of the lower housing 180. For example, it can penetrate from the light-transmitting hole 182. The key 194 is arranged in the key mounting hole 181 of the lower housing 180, and the key switch 193 is triggered by pressing the key 194.

[0047] In a specific implementation, the indicator light 192 can be a light-emitting diode, and it can emit light according to the control of the main control module 140 to indicate power-on operation or indicate the strength of the sensed signal, etc. The key 194 and the key switch 193 are used to obtain the control operations of the user, such as power-on / off, etc.

[0048] In some embodiments, the power module 150 includes a battery, and the battery is arranged in the battery compartment 183 of the lower housing. The battery compartment 183 can be closed by a battery compartment cover 184.

[0049] In a specific embodiment, referring to Figure 12 , the power supply module 150 further includes a PMOS transistor Q1, an NMOS transistor Q2, a double diode D2, a resistor R24, and a resistor R25. The positive electrode of the battery is connected to the source electrode of the PMOS transistor Q1 after accessing from the VIN terminal. The drain electrode of the PMOS transistor Q1 serves as the power supply terminal BATT+. The gate electrode of the PMOS transistor Q1 is connected to the drain electrode of the NMOS transistor Q2. The source electrode of the NMOS transistor Q2 is grounded. The NMOS transistor Q2 is connected to the power control terminal POW_EN of the main control module 140. The two ends of the resistor R24 are respectively connected to the source electrode and the gate electrode of the PMOS transistor Q1. The two ends of the resistor R25 are respectively connected to the source electrode and the gate electrode of the NMOS transistor Q2. The two anodes of the double diode D2 are respectively connected to the gate electrode of the PMOS transistor Q1 and the key signal terminal SW of the main control module 140. The cathode of the double diode D2 is grounded through the key switch KEY. When the user long-presses the key to turn on the key switch KEY, the gate electrode of the PMOS transistor Q1 is grounded through the double diode D2 and the key switch KEY, and the PMOS transistor Q1 is turned on. The device can obtain power supply through the power supply terminal BATT+, and the key signal terminal SW is also pulled low. The main control module 140 makes the power control terminal POW_EN at a high level, which can turn on the NMOS transistor Q2, and further makes the gate electrode of the PMOS transistor Q1 at a low level, which can keep the PMOS transistor Q1 turned on.

[0050] Referring to Figure 12 , the power supply module 150 further includes an NMOS transistor Q3, a resistor R3, and a resistor R6. The series-connected resistor R3 and resistor R6 are connected between the power supply terminal BATT+ and the ground. The source electrode of the NMOS transistor Q3 is grounded, the drain electrode is connected to the negative terminal BATT- of the battery, and the gate electrode is connected to the series connection point of the resistor R3 and the resistor R6. When the battery supply voltage is normal, the voltage level obtained by dividing the voltage of the power supply terminal BATT+ through the resistor R3 and the resistor R6 can turn on the NMOS transistor Q3, and the battery discharges continuously. When the battery supply voltage is too low, the voltage level obtained by dividing the voltage of the power supply terminal BATT+ through the resistor R3 and the resistor R6 cannot turn on the NMOS transistor Q3, and the battery stops discharging.

[0051] Referring to Figure 12 , the power supply module 150 further includes a voltage conversion module 151, and the voltage conversion module 151 is used to convert the battery output voltage into a 3.3V voltage.

[0052] In some embodiments, referring to Figures 7 to 10 , two supports 185 are provided on each side of the lower housing 180, and an installation post 186 is provided between the two supports 185 on each side. A gap 187 is formed between the installation post 186 and the side surface of the lower housing 180. The user can set a strap to pass through the gap 187, so as to fix the wireless monitor 100 to the vehicle.

[0053] In a specific implementation, refer to Figures 7 to 10 , the lower housing 180 is further provided with an antenna accommodating portion 188 for accommodating the antenna in the FM wireless transmission module 130.

[0054] The present invention is not limited to the above optional implementation manners. Any person can obtain other various forms of products under the inspiration of the present invention. However, no matter what changes are made in its shape or structure, as long as the technical solutions fall within the scope defined by the claims of the present invention, they all fall within the protection scope of the present invention.

Claims

1. A wireless monitoring device, characterized in that: It comprises a plurality of wireless monitors with different FM frequencies, each of which comprises an acquisition module, a signal conditioning module, an FM wireless transmission module, a main control module and a power module; the acquisition module is used for acquiring vibration and / or sound to obtain a first signal; the signal conditioning module is connected to the acquisition module and is used for filtering, conditioning and power amplifying the first signal to obtain a second signal; the FM wireless transmission module is connected to the signal conditioning module and is used for wirelessly transmitting the second signal by FM; the main control module is connected to the FM wireless transmission module and is used for controlling the FM frequency; the power module is used for providing power to the equipment on the wireless monitor.

2. A wireless monitoring device according to claim 1, characterized in that: The acquisition module includes a piezoelectric ceramic vibration sensor, and the first signal is obtained through the piezoelectric ceramic vibration sensor.

3. A wireless monitoring device according to claim 1, characterized in that: The signal conditioning module includes a filter amplification unit and an audio power amplification unit; the filter amplification unit is used to filter and amplify the first signal collected by the acquisition module; the audio power amplification unit is connected to the main control module and the filter amplification unit, and the audio power amplification unit is used to receive the enable signal of the main control module and the output signal of the filter amplification unit. When the enable signal of the main control module is received, the output signal of the filter amplification unit is power amplified to obtain a second signal in the form of a dual-channel audio signal.

4. A wireless monitoring device according to claim 1, characterized in that: The wireless monitor also includes a communication module, which is connected to the main control module and is used to receive setting information of the frequency modulation frequency.

5. A wireless monitoring device according to claim 4, characterized in that: The communication module includes a USB interface and a USB / serial port conversion chip.

6. A wireless monitoring device according to claim 1, characterized in that: It also includes an upper shell and a lower shell, a circuit board is arranged between the upper shell and the lower shell, and the acquisition module, the signal conditioning module, the frequency modulation wireless transmission module and the main control module are all arranged on the circuit board.

7. A wireless monitoring device according to claim 6, characterized in that: The acquisition module includes a cap-shaped shell, a metal plate and piezoelectric ceramics. A through hole is provided in the middle of the cap-shaped shell, the metal plate is fixedly arranged in the cap-shaped shell, and the piezoelectric ceramics are fixedly arranged under the metal plate; the circuit board is provided with a sensor mounting frame, the sensor mounting frame supports the outer edge of the cap-shaped shell, the upper shell is provided with a sensor mounting hole, and the top of the cap-shaped shell is exposed from the sensor mounting hole.

8. A wireless monitoring device according to claim 6, characterized in that: The wireless listening device also includes an indicator light, a push button switch and a button. The indicator light and the push button switch are both arranged on the circuit board and are both connected to the main control module. The light emitted by the indicator light is transmitted from the back of the lower shell. The button is arranged in the button mounting hole of the lower shell, and the push button switch is triggered by pressing the button.

9. A wireless monitoring device according to claim 6, characterized in that: The power module includes a battery, and the battery is arranged in a battery compartment of the lower shell.

10. A wireless monitoring device according to claim 6, characterized in that: Two supports are arranged on each side of the lower shell, and a mounting column is arranged between the two supports on each side, and a gap is formed between the mounting column and the side surface of the lower shell.

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