Patent Application
20240402586
The present invention relates to an acoustic camera equipped with explosion-proof means or waterproof means.
Registered Patent No. 10-1471299 (patent holder: SM Instrument Co., Ltd., Hyundai Motor Co., Ltd.) is composed of a front body in which a sound detecting parts of the sound sensors are arranged to face forward; sound sensors with a sound detecting part exposed to the front body while fixed to a substrate; a substrate on which sound sensors are mounted; an image capture unit in which a capture lens is exposed through a lens hole in the front body; a rear body surrounding the rear side of the substrate and the rear side of the image capture unit with the substrate positioned on the rear side of the front body; The front body includes a planar anterior plate. Disclosed is a mobile acoustic camera wherein the front plate and the substrate are arranged in parallel.
Since the microphone mounted on the board in an array form must detect sound through an acoustic detection hole, it must be exposed to the air environment to be detected from the perspective of air transmission. At this time, the microphone and microphone connection circuit are both contacted and exposed to the air environment to be detected. If an acoustic camera is installed in an ignitable gas environment with a high risk of explosion, there may be a risk of explosion due to the acoustic camera's power, electronic circuit, etc.
Registered Patent No. 10-1213540 (patent holder: SM Instruments Co., Ltd.) discloses an acoustic camera using an acoustic sensor array, characterized in that it includes a sound detection device that is mounted on a circuit board (Print Circuit Board, 20) and transmits signals related to the detected sound to the data collecting unit and a display unit connected to the sound detection device, connected to a data collecting unit that samples the analog signal about the sound transmitted from the sound detection device, converts it into a digital signal about the sound, and transmits it to the central processing unit, connected to a central processing unit that calculates each acoustic sensor and the associated noise level based on the digital signal about the sound transmitted from the data collecting unit and displaying the noise level related to each acoustic sensor calculated by the central processing unit in color. In the case of an acoustic camera, a groove is formed in front of the sensor because the acoustic sensor must be exposed to the air.
Registered Patent No. 10-1471299 (Patent Holder: SM Instrument Co., Ltd., Hyundai Motor Co., Ltd.) includes front body in which the acoustic detection part of the acoustic sensors is arranged to face forward; acoustic sensors whose acoustic detection part is exposed to the front body when fixed to the sensor board; sensor board on which acoustic sensors are mounted; video recording unit where the recording lens is exposed through the lens hole in the front body; and with the sensor board located on the rear side of the front body, the rear body surrounds the back of the sensor board and the rear of the image capture unit. The anterior body includes a planar anterior plate. Disclosed is a mobile acoustic camera characterized in that the front plate and the sensor board are arranged in parallel.
The present invention is to provide an acoustic camera having an explosion-proof structure that limits electrical energy to prevent ignition in a hazardous atmosphere by electric sparks, arcs, or high temperatures generated when the acoustic camera is normal or malfunctioning (disconnection, short circuit, etc.).
In addition, the present invention is intended to provide an acoustic camera having a pressure-resistant explosion-proof structure in which the effects of an explosion (ignition factor) inside the acoustic camera housing are not transmitted to the air or ignitable gas outside the housing.
In addition, the present invention is intended to provide an acoustic camera with excellent acoustic detection performance and a waterproof function so that it can be installed or portably used in outdoor places rather than indoors.
The acoustic camera equipped with the explosion-proof means of the present invention includes acoustic sensors (M) that detect sound waves or ultrasonic waves introduced through the sound wave induction grooves (21), a sensor board (20) on which the acoustic sensors (M) are mounted, a housing (40) located behind the sensor board (20) and forming a built-in space (Room), and a main control (50) that receives and processes sound signals generated by the acoustic sensors (M). The main control (50) is located in the built-in space (Room) inside the housing (40), and the sensor board (20) is located outside the housing (40).
The acoustic camera equipped with the explosion-proof means of this invention further includes a barrier circuit unit (60) installed between the acoustic sensors (M) and the main control unit (50), the barrier circuit unit (60) transmits the acoustic signal generated by the acoustic sensor (M) to the main control unit (50), the barrier circuit unit (60) suppresses the increase in current or voltage on the acoustic sensor (M) and the acoustic signal transmission line, and the barrier circuit unit (60) and the main control unit (50) are located in the interior room of the housing (40).
In the acoustic camera equipped with the explosion-proof means of the present invention, a data collection unit FPGA (61) is further provided between the sensor board (20) and the main control unit (50), and the barrier circuit unit (60) is provided between the sensor board (20) and the data collection unit (FPGA, 61).
The acoustic camera provided with the explosion-proof means of the present invention may further include a photographing means 30 for photographing a scene in which the sensor board 20 is facing as an image.
In the acoustic camera equipped with the explosion-proof means of this invention, the barrier circuit unit (60) includes a resistance (60a) for suppressing current rise and a Zener diode (60c) for suppressing voltage rise and a fuse (60b) for blocking overcurrent on the acoustic signal transmission line (PL) or the clock signal (CLK) that transmits the pulse density module signal (PDM) generated by the acoustic sensor (M).
In the acoustic camera equipped with the explosion-proof means of the present invention, the barrier circuit unit 60 is connected to the acoustic signal common transmission line PL_common via the first acoustic signal transmission line PL_sub1, the second acoustic sensor M2 is connected to the acoustic signal common transmission line PL_common via the second acoustic signal transmission line PL_sub2, and the first acoustic sensor M1 is connected to the acoustic signal common transmission line CL_common via the first clock signal transmission line CL_sub1, and the second acoustic sensor M2 is connected to the clock signal common transmission line CL_common via the second clock signal transmission line CL_sub2.
The acoustic signal common transmission line (PL_common) includes a resistance installation unit (PL_common 1) with a resistance 60a to suppress current rise, an electronic device installation unit (PL_common 2) with a Zener diode (60c) to suppress voltage rise, and a fuse installation unit (PL_common 3) with fuses (use, 60b) for blocking overcurrent.
The acoustic sensors M mounted on the sensor board 40 are disposed to have a separation distance of 1.5 mm or more from each other.
The distance between the acoustic signal transmission line PL and the clock signal transmission line CL is preferably 1.5 mm or more, and the separation distance between one acoustic signal common transmission line PL_common and the other acoustic signal common transmission line CL_common is preferably 1.5 mm or more.
A separation distance between any one of a plurality of fuses 60b and the other fuse may be preferably 10 mm or more.
In an acoustic camera equipped with an explosion-proof means of the present invention, the housing 40 includes a front partition wall portion 41 located behind the sensor board 20, the housing 40 includes a rear wall portion 42, a side wall portion 43, and a front partition wall portion 41 forming a room blocked from the outside, and the sensor board 20 equipped with the acoustic sensor M is preferably located in front of the front partition portion 41 outside the housing 40.
The acoustic camera equipped with the explosion-proof means of this invention preferably includes a front body (10) equipped with multiple sound wave inflow holes (11) that induce sound waves or ultrasonic waves to reach the acoustic sensor (M).
In the acoustic camera equipped with the explosion-proof means of the present invention, it is preferable that the front partition wall 41 includes an imaging hole 41a, the imaging hole 41a is closed with a transparent tempered glass 35, and the imaging means 30 is located behind the tempered glass 35 and in the interior space room of the housing 40.
The acoustic camera equipped with the waterproof means of the present invention includes a front body 10 equipped with the sound wave inflow holes 11, acoustic sensors (M) that detect sound waves or ultrasonic waves entering through the sound wave inflow holes 11 or sound wave induction grooves 21, a sensor board 20 equipped with sound sensors (M), a photographing means 30 that captures the scene where the front body 10 is facing, a housing 40 that covers the rear of the front body 10, and a waterproof means part 90 that prevents water from reaching the acoustic sensor (M) or sensor board 20 through the sound wave inflow hole 11.
In the acoustic camera equipped with the waterproof means of the present invention, the waterproof means part 90 includes a sound wave-permeable waterproof membrane 91 that shields the sound wave inflow hole 11 in the transverse direction to prevent water from penetrating. The position of the sound wave-permeable waterproof membrane 91 is characterized by being provided between the front surface of the front body 10, the middle point of the sound wave inflow hole 11 (the point between the front end and the rear end of the sound inflow hole 11), or between the rear surface of the front body 10 and the front surface of the sensor board 20.
In the acoustic camera equipped with the waterproof means of this invention, the sound wave inflow hole (11) is characterized in that the width or diameter of the front side (exposed side) is larger than the width or diameter of the rear side (substrate side) and the cross-sectional area continuously increases from the rear side (substrate side) to the front side (exposed side).
In the acoustic camera equipped with the waterproof means of the present invention, the waterproof means part 90 consists of a sound wave-permeable waterproof membrane 91 that horizontally shields the sound wave inflow hole 11, a first adhesive layer 92 located on the rear surface of the front body 10 or the front surface of the sound wave-permeable waterproof membrane 91, and a compressible sponge layer 94 attached to the opposite side of the first adhesive layer and pressed (pressurized) in contact with the front of the sensor board 20.
The acoustic camera equipped with the waterproof means of this invention is characterized in that a counter bore 96 formed to be stepped from the rear of the front body 10 is further formed in the sound wave inflow hole 11, the waterproof means part 90 is placed in the counter bore 96, and the first adhesive layer 92 is in contact with the bottom surface of the counter bore 96.
In the acoustic camera equipped with the waterproof means of the present invention, the thickness of the sound-transmitting waterproof membrane 91 of the waterproof means part 90 is 0.005 to 0.02 mm.
In the acoustic camera equipped with the waterproof means of the present invention, the waterproof means part 90 is located on the rear side (opposite side of the first adhesive layer 92) of the sponge layer 94 and further includes a second adhesive layer 95 attached to the front of the sensor board 20.
In the acoustic camera equipped with the waterproof means of the present invention, the depth of the counter bore 96 is 0.2 to 2 mm.
The acoustic camera equipped with the waterproof means of the present invention is characterized in that it further includes an upper protruding cover part 12 fixed to the upper part of the front body 10 or the housing 40 and protruding further forward than the front surface of the front body 10.
According to the present invention, an acoustic camera having an explosion-proof structure that limits electrical energy to prevent ignition in a hazardous atmosphere by electric sparks, arcs, or high temperatures generated when the acoustic camera is normal or malfunctions (disconnection, short circuit, etc.) is provided.
In addition, according to the present invention, an acoustic camera having a pressure-resistant explosion-proof structure is provided in which the influence of an explosion (ignition factor) inside the acoustic camera housing is not transmitted to the air or ignitable gas outside the housing.
In addition, according to the present invention, an acoustic camera with excellent acoustic detection performance and a waterproof function is provided so that it can be installed or portably used in outdoor places rather than indoors.
Hereinafter, an acoustic camera equipped with explosion-proof means according to an embodiment of the present invention will be described in detail with reference to the attached drawings.
As shown in
As shown in
The acoustic wave guidance groove 21 is composed of a groove dug in the sensor board 20 and the acoustic sensor M attached to the rear end of the sensor board 20.
The acoustic camera equipped with explosion-proof or waterproof means according to an embodiment of the present invention further includes a data collecting unit (FPGA, 61) between the sensor board 20 and the main control unit 50.
The barrier circuit unit 60 is provided between the sensor board 20 and the data collecting unit (FPGA, 61). The operation processing unit 13 placed in the built-in space (Room) of the housing 40 is connected to the main control unit 50.
The sensor board 20 and the barrier circuit unit 60 are connected to each other by a molding connector 22.
An acoustic camera equipped with explosion-proof or waterproof means according to an embodiment of the present invention includes a housing 40 and a terminal unit 70 connected to the front body 10 by a molding connector 22.
The terminal unit 70 includes a terminal block 71, a line bushing 72, and a cable connector 74.
A line bushing 72 is connected to a splitter 73 located in the main control unit 50.
The data collecting unit 61 collects acoustic (sound wave or ultrasonic wave) signals detected by the acoustic sensors M through the sensor board 20.
The main control unit 50 calculates at least one acoustic parameter (e.g., beam power level at a point on a virtual plane) required for sound field visualization based on the acoustic signal from the data collecting unit 61.
The main control unit 50 performs beam forming.
In addition, the main control unit 50 converts the generated sound parameters into color images. Then, the main control unit 50 creates a photo-acoustic superimposed image by superimposing the optical image generated through the photographing means 30 and the acoustic color image generated by acoustic signal calculation.
As shown in
Here, among the frequency bands analyzed (beam forming and sound field visualization) by the main control unit 50, at least some frequencies fall within the range of 200 Hz to 100 KHz.
More specifically, among the frequency bands analyzed and processed by the operation processing unit 13 of the acoustic camera based on the acoustic (sound wave or ultrasonic) signal detected by the acoustic sensors M, it is desirable that at least some frequencies fall within the range of 10 KHz to 30 KHz.
For example, in one embodiment, if the analysis possible range is 1 KHz to 15 KHz, at least a portion of “10 KHz to 15 KHz” falls within the “frequency: 10 KHz to 30 KHz range”, which is the range of the present invention, and is therefore included in the scope of the present invention.
Additionally, in another embodiment, when the analysis possible range is 25 KHz to 50 KHz, at least a portion of “25 KHz to 30 KHz” falls within the “frequency: 10 KHz to 30 KHz range”, which is the range of the present invention, and is therefore included in the scope of the present invention.
As shown in
The barrier circuit unit 60 suppresses an increase in current and voltage on the acoustic signal transmission line (e.g., PDM signal) and the clock signal from the acoustic sensor M.
The barrier circuit unit 60 transmits the acoustic signal generated by the acoustic sensor M to the main control unit 50.
The barrier circuit unit 60 and the main control unit 50 are located in the built-in space (Room) of the housing 40. The clock signal proceeds from the data collecting unit (FPGA, 61) toward the acoustic sensor (M).
An acoustic signal (e.g., a PDM signal) is transmitted from the acoustic sensor M to the data collecting unit (FPGA, 61).
Intrinsically safe explosion-proof structure is an explosion-proof structure that limits electrical energy so that it does not ignite in a hazardous atmosphere due to electric sparks, arcs, or high temperatures generated during normal or malfunction.
Intrinsically safe explosion-proof structures are characterized by being designed in consideration of the failure conditions of the device.
If the explosion-proof camera is configured only as explosion-proof, there is a problem in that sound is not transmitted to the acoustic sensor.
To solve this problem, it can be configured as intrinsically safe explosion proof.
In order to connect the acoustic sensor M and the data collecting unit (FPGA, 61) by a circuit, the barrier circuit unit 60 is located between the acoustic sensor M and the data collecting unit (FPGA, 61).
The barrier circuit unit 60 passes normal low energy signals, and passes signals with abnormal high-energy levels by limiting them to within the allowable level of the hazardous area.
According to one embodiment of the present invention, the voltage is limited using double or triple Zener diodes 60c constituting the barrier circuit unit 60. A resistance 60a is used to limit the current, and a fuse 60b is used to block abnormal power that is difficult for the Zener diode 60c to handle.
As shown in
According to one embodiment of the present invention, the barrier PCB area of the barrier circuit unit includes a first PCB area and a second PCB area.
The first PCB area includes a resistance 60a, a Zener diode 60c, a fuse 60b, and an opto-coupler 60d. The second PCB area includes an opto-coupler 60d.
As shown in
The first microphone (M1) is connected to the acoustic signal common transmission line (CL_common) via the first clock signal transmission line (CL_sub1). The second microphone (M2) is connected to the clock signal common transmission line (CL_common) via the second clock signal transmission line (CL_sub2).
As shown in
The clock signal common transmission line (CL_common) includes resistance installation section (CL_Common 1) where resistance (60a) is installed, Zener diode installation section (CL_common 2) where Zener diode (60c) is installed, and a fuse installation section (CL_common 3) where a fuse (60b) is installed.
Additionally, one resistance 60a may be installed on each of the acoustic signal transmission line (PL_sub1) and the second acoustic signal transmission line (PL_sub2).
Two Zener diodes 60c are installed in the Zener diode installation part (PL_common_2).
As shown in
It is possible to prevent the accumulation of electrical energy that increases the risk of overheating and explosion due to mutual proximity of acoustic sensors M below 1.5 mm.
As shown in
At less than 1.5 mm, it is possible to prevent the accumulation of electrical energy that increases the risk of overheating and explosion of the board due to proximity to circuit lines.
According to one embodiment of the present invention, it is preferable that the separation distance between one fuse 60b and the other fuse 60b is 10 mm or more.
It is possible to prevent the accumulation of electrical energy that increases the risk of overheating and explosion due to the proximity of fuses 60b below 10 mm.
In one embodiment of the present invention, the power of the acoustic sensors M is 3.3 V.
Test results showed that even if the power of the acoustic sensors (M) was extended to the 1 to 5V range, the numerical limit was effective from an explosion-proof perspective.
It was found that within the numerical range, the risk of explosion of the acoustic camera was significantly reduced in high-explosive environments such as hydrogen gas.
As shown in
The molding connector 22 is coated with epoxy coating 23 and has excellent electrical insulation safety, high thermal conductivity, and low expansion coefficient.
In addition, due to the high moisture resistance due to the epoxy coating 23, it absorbs a very small amount of water and is excellent in waterproofing.
As shown in
A pin header 24 is inserted into the pin header insertion portion 25 located on both sides of the sensor board 20.
As shown in
For example, when 112 (N) acoustic sensors M are used and form a 2 Ch common line as shown in
At this time, as shown in
When using a pair of Zener diodes 60c at one point, 56 (N/2) pairs of Zener diodes 60c are provided on the acoustic signal common transmission line.
The same principle applies to the clock signal common transmission line (CL_common).
As shown in
The housing 40 includes a rear wall part 42, a side wall 43, and a front partition 41 that form a built-in space (Room) blocked from the outside.
The sensor board 20 on which the acoustic sensor M is mounted is located in front of the front partition 41 outside the housing 40 (outside the built-in space).
The front partition 41 has an imaging hole 41a.
The imaging hole 41a is closed with transparent tempered glass 35.
The photographing means 30 is located behind the tempered glass 35 and in the built-in space (Room) of the housing 40.
The housing partition walls 41, 42, and 43 are characterized by having a pressure-resistant explosion-proof structure.
The pressure explosion-proof structure does not cause ignition even if an explosion occurs inside the housing 40.
Therefore, high-voltage equipment such as a data collecting unit (FPGA, 61), a main control unit 50, and a splitter 73 are built into the explosion-proof case.
The photographing means 30 is also located inside the housing 40 and is designed as a pressure-resistant explosion-proof structure, so even if the photographing means 30 explodes, it does not ignite.
Many cables with a pressure explosion-proof structure are characterized by thread processing and molding processing.
A molding connector 22 connects the sensor board 20 and the housing 40.
One end of the molding connector 22 facing the acoustic sensor M of the front body 10 is located on the radial outer side with respect to the central axis. The other end of the molding connector 22 facing the barrier circuit unit 60 is located on the inner side in the radial direction with respect to the central axis.
The interior of the molding connector 22 is an example of a pressure-resistant explosion-proof structure and is characterized by having an epoxy molding structure in response to explosion.
The epoxy molding structure serves to prevent explosive residues from leaking out.
Pressure-resistant explosion-proof structure refers to a structure designed so that the container can withstand explosion pressure and prevent the explosion flame from spreading outside the container.
A pressure-resistant explosion-proof structure is an explosion-proof structure that recognizes an explosion inside the container and recognizes an ignition source inside the container.
The standard for device temperature grade (T) refers to the surface temperature outside the container, and changes in the shape, arrangement, and volume of the device's internal parts can affect the explosion pressure.
Variations in heat generation depending on the electrical rating of the device's internal components can affect the device's temperature rating.
It is desirable to prevent the internal parts of devices in pressure explosion-proof containers from being arbitrarily replaced or altered.
As shown in
As shown, in the sound wave inlet holes 11, the width (or diameter) of the outer exposed portion may be the same as the width (or diameter) of the adjacent portion of the sensor.
Alternatively, it may be configured as an expanded shape with a cross-sectional area that increases from the adjacent part of the sensor to the outer exposed part.
The front body 10 is made of plastic or metal, and can be produced by injection molding, etc., and then form the sound wave inlet hole 11 by cutting, punching, or processing. As shown in
For heights greater than 50 cm, it is inappropriate to configure a portable acoustic camera.
In the case of 5 cm or less, there is a problem in that the number and separation distance of acoustic sensors are limited.
Therefore, a range of 5.0 to 50 cm is appropriate, and more preferably, a range of 7.5 to 35 cm is desirable from a movability point of view.
As shown in
One sound wave inlet hole 11 of the front body 10 and one acoustic wave guidance groove 21 of the sensor board 20 are coupled to each other in communication with each other at corresponding positions.
Here, the number of sound wave inflow holes 11 is preferably 10 to 300, but if the number is less than 10, the separation distance between sensors on a board of the same size increases and the upper limit of the frequency at which the sound field can be visualized is limited.
If there are more than 300, there is a problem that the handling data throughput increases more than necessary, and the number of sensors in an actual 10˜20 cm acoustic (ultrasonic) camera is more than necessary, so installation problems arise when considering the separation distance between sensors.
10 to 300 is preferred, and 20 to 100 is more preferred for an acoustic or ultrasonic camera in the 5.0 to 50 cm range.
The plurality of acoustic sensors M are mounted integrally on the rigid or flexible sensor board 20, and the front body 10 and the sensor board 20 are integrally coupled. Accordingly, one acoustic sensor M is positioned correspondingly inside one sound wave inlet hole 11.
As shown in
Acoustic cameras equipped with explosion-proof means target gas group IIC, and gas group IIC consists of gas vapor and acetylene hydrogen.
Acoustic cameras equipped with explosion-proof means operate at 10V or less, so they target gas group IIC, and intrinsic safety can be achieved when current flows up to 2 A. However, acoustic cameras equipped with explosion-proof means operate at 0.2 A or less at 10V or less, so intrinsic safety can be achieved.
As shown in
The barrier circuit result diagram shows the signal waveform when the barrier circuit unit 60 is applied.
It can be seen that there is no significant difference between the signal waveform of the original result diagram and the signal waveform of the barrier circuit result diagram.
In other words, the test results showed that the data analysis performance (sound field visualization performance, sound wave and ultrasonic band) did not change compared to before the barrier circuit.
Increased safety refers to a structure that increases safety against mechanical, electrical, and temperature rises to prevent the occurrence of electric sparks, arcs, or high-temperature parts.
Increased safety does not recognize ignition sources and prevents ignition from occurring.
In addition, it plays a role in monitoring temperature rises (e.g., overload) and serves to strengthen insulation performance.
The temperature grade is based on the maximum surface temperature inside and outside the container, the rated load when starting the device, overload, and the temperature limit of the insulated winding.
As shown in
The terminal unit plays the role of increased safety, and for this purpose, the terminal block 71 satisfies the standards for increased safety.
Additionally, the terminal block 71 serves to prevent the high-voltage cable forming the explosion-proof structure from being exposed to the outside.
In addition, in order to perform the role of increased safety, the terminal unit 70 is characterized by a long distance between components.
As shown in
In addition, it may further include an upper protruding cover part 12 that is fixed to the upper part of the front body 10 or the housing 40 and protrudes further forward than the front of the front body 10.
According to one embodiment of the present invention, the front body 10 is provided with a plurality of sound wave inflow holes 11 that guide sound waves or ultrasonic waves to reach the acoustic sensor M.
The acoustic sensor M detects sound waves flowing in through the sound wave inlet hole 11 of the front body 10 while being fixed to the sensor board 20.
Acoustic sensors (M) are mounted on the sensor board 20.
The photographing means 30 photographs the scene toward which the front body 10 is facing.
In one embodiment of the present invention, the photographing means 30 includes an optical lens for imaging. The optical lens is optically exposed toward the front through the imaging hole 41a located in the center of the front body 10 to capture images.
According to one embodiment of the present invention, the housing 40 covers the sensor board 20 and the rear of the front body 10, with the sensor board 20 located on the rear side of the front body 10.
The waterproof means unit 90 blocks water from reaching the acoustic sensor M or the sensor board 20 through the sound wave inlet hole 11.
As shown in
According to one embodiment of the present invention, the data collecting unit 61 and the operation processing unit 13 are placed in the built-in space (Room) formed by the front body 10 and the housing 40.
Here, among the frequency bands analyzed and processed by the operation processing unit 13, at least some frequencies fall within the range of 200 Hz to 100 KHz.
More specifically, among the frequency bands analyzed and processed by the operation processing unit 13 of the acoustic camera based on the acoustic (sound wave or ultrasonic) signal detected by the acoustic sensor M, it is preferable that at least some frequencies fall within the 10 KHz˜30 KHz range.
For example, in one embodiment, when the analyzable range is 1 KHz to 15 KHz, at least part of “10 KHz to 15 KHz” falls within the “frequency: 10 KHz to 30 KHz range”, which is the range of the present invention, and is therefore included in the scope of the present invention.
In addition, in another embodiment, when the analyzable range is 25 KHz to 50 KHz, at least part of “25 KHz to 30 KHz” falls within the “frequency: 10 KHz to 30 KHz range”, which is the range of the present invention, and is therefore included in the scope of the present invention.
As shown in
According to one embodiment of the present invention, the sound wave inlet holes 11 may be configured so that the width (or diameter) of the outer exposed portion is the same as the width (or diameter) of the adjacent portion of the sensor.
Alternatively, it includes an expanded shape in which the cross-sectional area increases from the adjacent part of the sensor to the outer exposed part.
The front body 10 is made of plastic or metal and can be produced by injection molding or the like, and then form the sound wave inlet hole 11 by cutting or punching.
According to one embodiment of the present invention, either the horizontal or vertical size of the front body 10 is in the range of 5.0 to 50 cm.
For heights greater than 50 cm, it is inappropriate to configure a portable acoustic camera.
In the case of 5 cm or less, there is a problem in that the number and separation distance of acoustic sensors are limited.
Therefore, a range of 5.0 to 50 cm is appropriate, and more preferably, a range of 7.5 to 35 cm is desirable from a movability point of view.
As shown in
Here, the number of sound wave inflow holes 11 is preferably 10 to 300, but if the number is less than 10, the separation distance between sensors on a board of the same size increases and the upper limit of the frequency at which the sound field can be visualized is limited.
If there are more than 300, there is a problem that the handling data throughput increases more than necessary, and the number of sensors in an actual 10˜20 cm acoustic (ultrasonic) camera is more than necessary, so installation problems arise when considering the separation distance between sensors.
The number of sound wave inlet holes is preferably 10 to 300, and more preferably 20 to 100 for an acoustic or ultrasonic camera with a range of 5.0 to 50 cm.
According to
As shown in
Sound waves pass through the sound wave-permeable waterproof membrane 91 and are transmitted toward the substrate, but water does not penetrate the sound wave-permeable waterproof membrane 91.
The sound wave-permeable waterproof membrane 91 may be located on the front of the front body 10 or at the midpoint of the sound wave inlet hole 11 (a point between the front and rear ends of the sound wave inlet hole).
There are cases where the sound wave-permeable waterproof membrane 91 is located at an intermediate point (a point between the front end and the rear end of the sound wave inlet hole). At this time, the inner wall forming the sound wave inlet hole 11 may be manufactured separately and then assembled after inserting the sound wave-permeable waterproof membrane 91.
The acoustic sensors M attached to the sensor board 20 are positioned facing the sound wave inlet holes 11 and the waterproof means unit 90 at corresponding positions.
The waterproof means unit 90 may be composed of a sound wave-permeable waterproof membrane 91, a first adhesive layer 92, and a sponge layer 94.
The first adhesive layer 92 is located at the periphery and front side of the sound wave-permeable waterproof membrane 91 and comes into contact with the rear side of the front body 10.
At this time, the sponge layer 94 is attached to the rear peripheral portion (opposite the first adhesive layer) of the sound wave-permeable waterproof membrane 91. And it includes a material that is in contact with the front surface of the sensor board 20 and is pressed and compressible by the pressure of the sensor board 20.
As shown in
The sponge layer 94 is attached to the front surface of the sensor board 20 by the second adhesive layer 95. The thickness of the sound wave-permeable waterproof membrane 91 of the waterproof means unit 90 is preferably 0.005 to 0.02 mm.
If it is less than 0.005 mm, it is difficult to manufacture and waterproofness is weakened, and if it is more than 0.02 mm, waterproofness increases but sound wave permeability is poor.
The fabric of the sound wave-permeable waterproof membrane 91 was F69 MBR fabric ordered from Kolon Materials (Address: Kolon Tower, 11 Kolon-ro, Gwacheon-si, Gyeonggi-do, Korea). As shown in
The waterproof means unit 90 is placed in a counter bore 96.
The peripheral portion of the sound wave-permeable waterproof membrane 91 is attached to the bottom surface of the counter bore 96 by a first adhesive layer 92.
According to one embodiment of the present invention, the counter bore 96 may be a stepped groove or a flat cylindrical groove formed on the opposite side of the sound wave inlet hole 11 formed forward, that is, on the rear side of the front body 10 toward the front side.
A counter bore 96 communicates with the rear of the sound wave inlet hole 11.
The counter bore 96 provides a space in which the waterproof means unit 90 is placed and provides convenience in installing the waterproof means unit 90.
The step of the counter bore 96 prevents the waterproof means unit 90 from deviating laterally.
As shown in
In such a state, as shown in
The depth of the counter bore 96 is preferably 0.2 to 2 mm. If the depth of the counter bore 96 is less than 0.2 mm, lateral deviation of the waterproof means unit 90 may occur. Therefore, when the depth of the counter bore 96 is more than 2 mm, there is a problem in that the size of the waterproof means unit 90 becomes larger than necessary.
In one embodiment of the present invention shown in
The sponge layer 94 has restoring force while being pressed by 0.21 mm by the pressure of the sensor board 20.
Due to the restoring force of the sponge layer 94, the sponge layer 94 adheres the peripheral portion of the sound wave-transmitting waterproof membrane 91 to the bottom surface of the counter bore 96 or the rear surface of the front body 10.
As a result, separation and disengagement of the sound wave-permeable waterproof membrane 91 is prevented.
Additionally, a resilient pressurized sponge layer (94) presses against the rear periphery of the sound wave-permeable waterproof membrane 91. As a result, the inflow of water through the gap between the front periphery of the sound wave-permeable waterproof membrane 91 and the rear surface of the front body 10 (or the bottom surface of the counter bore 96) is blocked.
In
In
In
Generally, the higher the msl, the better the performance of the array sensor.
In
The smaller the beam width, the better the ability to distinguish multiple nearby noise sources, and generally, the smaller the 3 dB bandwidth, the better the performance of an array sensor.
In
As shown in
As shown in
The water spray test conditions are as follows.
As shown in
Although the invention has been described in connection with the above-mentioned preferred embodiments, the scope of the invention is not limited to these embodiments. The scope of the present invention is defined by the following patent claims and will include various modifications and variations within the scope of equivalents to the present invention.
The drawing symbols used in the patent claims below are merely intended to aid understanding of the invention and do not affect the interpretation of the scope of rights. The scope of rights should not be narrowly interpreted based on the drawing symbols.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0140720 | Oct 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/016091 | 10/20/2022 | WO |
