Fluid flow detection and temperature detection system for internal combustion engines

Abstract

The present invention relates to a fluid flow detection and temperature detection system for an internal combustion engine developed for the purpose of measuring temperature and detecting fluid flow in automobile and marine internal combustion engines, industrial applications, etc. More specifically, it provides a fluid flow detection and temperature detection system for an internal combustion engine that enables calorimetric fluid flow detection and temperature measurement by integrating a plurality of temperature sensors inside a flexible printed circuit board (PCB).

Description

Technology Field

[0001] The present invention relates to a fluid flow detection and temperature detection system for an internal combustion engine developed for the purpose of measuring temperature and detecting fluid flow in automobile and marine internal combustion engines, industrial applications, etc. More specifically, it relates to a fluid flow detection and temperature detection system for an internal combustion engine that integrates a plurality of temperature sensors inside a flexible printed circuit board (PCB) to enable calorimetric fluid flow detection and temperature measurement. Background Technology

[0003] In systems where internal combustion engines operate, a large amount of fluid typically circulates, and the fluid performs key functions such as cooling, lubrication, and fuel supply.

[0004] Since such fluids can cause serious mechanical failures such as engine overheating, friction damage, and fuel supply abnormalities if temperature changes or flow abnormalities occur, a sensor system that accurately detects the temperature and flow rate of the fluid is essential.

[0005] Conventionally, single temperature sensor-based detection methods, mechanical flow meter-based detection methods, and electrical resistance-based temperature detection methods have been primarily used.

[0006] The single-temperature sensor-based detection method measures the temperature at a specific location by inserting a single temperature sensor into a water tank or flow path. Since the presence of fluid flow is determined indirectly based on temperature change trends or in combination with a pressure sensor, it has limitations in accurate flow detection and has the disadvantage that there is a possibility of incorrect judgment if structural reliability is poor.

[0007] Mechanical flow meter-based sensing methods detect flow velocity as a mechanical turbine or rotor rotates due to fluid flow, but they have disadvantages such as a high possibility of rotor malfunction due to fluid viscosity, foreign substances, slow response speed, and difficulties in miniaturization.

[0008] The electrical resistance temperature sensing method measures temperature using electrical resistance-based sensors such as PT100s and thermistors. Based on general analog circuits, it has the disadvantage of sensor noise and degraded linearity in high-temperature / high-vibration environments.

[0009] The problems of the conventional technology are as follows.

[0010] When composed of a single temperature sensor or an asynchronous sensor array, it is difficult to accurately determine fluid flow, and there is a problem where errors may occur due to time delays between sensors.

[0011] The operating environment of internal combustion engines is characterized by severe vibration, heat, humidity, and contaminants, which poses issues regarding the signal stability and durability of the sensors.

[0013] Korean registered patent [10-0206085] discloses a method for manufacturing a sensor that detects temperature and flow. Prior art literature

[0015] Korean Registered Patent [10-0206085] (Registration Date: April 7, 1999) The problem to be solved

[0016] Accordingly, the present invention has been devised to solve the problems described above, and the objective of the present invention is to provide a fluid flow and temperature sensing system for an internal combustion engine that integrates a plurality of temperature sensors inside a flexible printed circuit board (PCB) to enable calorimetric fluid flow detection and temperature measurement.

[0018] The purposes of the embodiments of the present invention are not limited to those mentioned above, and other unmentioned purposes will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0020] A fluid flow detection and temperature detection system for an internal combustion engine according to an embodiment of the present invention for achieving the above-mentioned purpose comprises: a body part (100) coupled to a tank or pipe to measure fluid flow and temperature; a protrusion part (200) protruding forward from the body part (100), wherein the protruding part is positioned so as to be exposed to fluid inside the tank or pipe to measure fluid flow and temperature; a circuit part (300) surrounding the outer circumference of the protrusion part (200), wherein a plurality of temperature sensors are integrally formed, and the circuit part is composed of a flexible printed circuit; and a controller (700) that detects fluid flow and measures temperature based on a signal received from the temperature sensor of the circuit part (300).

[0021] In addition, the circuit portion (300) includes a first temperature sensor (310); and a second temperature sensor (320); and is characterized in that the first temperature sensor (310) and the second temperature sensor (320) are provided at different locations.

[0022] Additionally, the controller (700) is characterized by receiving an analog signal through the thermoelectric elements of the first temperature sensor (310) and the second temperature sensor (320), converting it into a linearized digital signal through a filter, detecting the flow of fluid according to the change in temperature, and transmitting it as an output.

[0023] Additionally, the circuit section (300) includes a third temperature sensor (330); and is characterized in that the third temperature sensor (330) can measure a wider temperature range compared to the first temperature sensor (310) and the second temperature sensor (320).

[0024] Additionally, the controller (700) is characterized by receiving an analog signal through the thermoelectric element of the third temperature sensor (330), converting it into a digital signal, and displaying the temperature inside the water tank or pipe.

[0025] In addition, the fluid flow detection and temperature detection system of the internal combustion engine is characterized by including a first port (400) at the rear end of the protrusion (200) that can connect a microchip (MCU) or electronic circuit hardware (H / W) controller capable of converting an analog signal, which is an electrical signal, into a digital signal using a temperature sensor signal.

[0026] Additionally, the fluid flow detection and temperature detection system of the internal combustion engine is characterized by including a second port (500) at the rear end of the body part (100) that can be connected to the controller (700).

[0027] In addition, the fluid flow detection and temperature detection system of the internal combustion engine described above is characterized by including a fourth temperature sensor (910) which is a gas-operated analog thermometer, and an analog system unit (900) that measures the temperature inside a water tank or pipe. Effects of the invention

[0029] According to a fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention, by integrating a plurality of temperature sensors into a flexible printed circuit board (FPCB), it is possible to precisely measure the presence or absence of fluid flow (coolant, lubricating oil, etc.) and the temperature based on the temperature sensors, while simultaneously ensuring space efficiency, precision, and fault responsiveness. Brief explanation of the drawing

[0031] FIG. 1 is a conceptual diagram of a fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention. FIG. 2 is an example diagram showing an example in which a plurality of temperature sensors are included in the circuit section of FIG. 1. Figure 3 is an example diagram showing an example in which a port is included in the configuration of Figure 1. FIG. 4 is an exemplary diagram showing an example in which an analog system part including a fourth temperature sensor is additionally installed in the configuration of FIG. 1, wherein a body part is fixed to the outside of the pipe and a protrusion part and a fourth temperature sensor are inserted into the inside of the pipe. Specific details for implementing the invention

[0032] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0033] When it is stated that one component is "connected" or "joined" to another component, it should be understood that it may be directly connected to or joined to that other component, or that there may be other components in between.

[0034] On the other hand, when it is stated that one component is "directly connected" or "directly coupled" to another component, it should be understood that there are no other components in between.

[0035] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, processes, operations, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, processes, operations, components, parts, or combinations thereof.

[0036] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0037] The present invention will be described in more detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Furthermore, unless otherwise defined, technical and scientific terms used shall have the meaning commonly understood by those skilled in the art to which this invention pertains. Descriptions of known functions and configurations that could unnecessarily obscure the essence of the present invention in the following description and attached drawings are omitted. The drawings presented below are provided as examples to ensure that the spirit of the present invention is sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms. Additionally, throughout the specification, the same reference numerals indicate the same components. It should be noted that the same components in the drawings are represented by the same reference numerals wherever possible.

[0039] FIG. 1 is a conceptual diagram of a fluid flow detection and temperature detection system for an internal combustion engine according to an embodiment of the present invention, FIG. 2 is an exemplary diagram showing an example in which a plurality of temperature sensors are included in the circuit portion of FIG. 1, FIG. 3 is an exemplary diagram showing an example in which a port is included in the configuration of FIG. 1, FIG. 4 is an exemplary diagram showing an example in which an analog system portion including a fourth temperature sensor is additionally installed in the configuration of FIG. 1, and a body portion is fixed to the outside of the pipe, and a protrusion portion and a fourth temperature sensor are inserted into the inside of the pipe.

[0041] The present invention is intended to provide a structure capable of precisely and stably detecting the water level in systems that store or use fluids, such as ships, automobiles, and industrial tanks.

[0043] FIG. 1 is a conceptual diagram of a fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention, showing an embodiment in which an integrated circuit (200) is provided inside a protrusion (200).

[0044] As illustrated in FIG. 1, a fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention comprises a body part (100), a protrusion part (200), a circuit part (300), and a controller (700).

[0045] The body part (100) is connected to a tank or pipe to measure the flow and temperature of the fluid.

[0046] The above body part (100) is structured to be attached to the outer wall of a ‘water tank’ or ‘pipe’ through which fluid flows, making installation easy, and performs mechanical support and fixing functions of the system.

[0047] The protrusion (200) protrudes forward from the body part (100), and the protruding part is positioned so as to be exposed to the fluid inside a tank or pipe to measure the fluid flow and temperature.

[0048] The above protrusion (200) protrudes forward from the body part (100), and the protrusion (200) protruding forward from the body part (100) protrudes into the inside of a 'water tank' or 'pipe' and is directly exposed inside the fluid.

[0049] Since the above protrusion (200) is in direct contact with the fluid, sensitive measurement of the sensor is possible.

[0050] For example, a protrusion is inserted into a pipe through which coolant flows to detect the fluid flow and temperature.

[0051] The circuit portion (300) surrounds the outer periphery of the protrusion (200), and a plurality of temperature sensors are integrally formed and composed of a flexible printed circuit.

[0052] The above circuit portion (300) wraps around the outer circumference of the protrusion in the form of a flexible printed circuit board (FPCB).

[0053] A plurality of temperature sensors are integrally mounted in the above circuit section (300).

[0054] The above circuit section (300) can comprehensively detect fluid temperature, flow rate based on temperature difference, whether it is overheated, etc.

[0055] The above circuit section (300) can be easily installed within the complex structure of an internal combustion engine based on a flexible substrate, thereby increasing space efficiency.

[0056] The controller (700) detects the flow of fluid and measures the temperature based on a signal received from the temperature sensor of the circuit unit (300).

[0057] The above controller (700) is a control device that receives and analyzes signals transmitted from each temperature sensor of the circuit unit (300).

[0058] The above controller (700) can determine whether fluid flows based on a specific temperature difference (caloric flow meter principle). That is, flow detection is possible.

[0059] In addition, the above controller (700) can provide additional responses, such as correction when an anomaly is detected, based on a combination of multiple sensors and controller operations.

[0061] As illustrated in FIG. 2, the circuit portion (300) of the fluid flow detection and temperature detection system of an internal combustion engine according to one embodiment of the present invention includes a first temperature sensor (310) and a second temperature sensor (320), and

[0062] The first temperature sensor (310) and the second temperature sensor (320) may be characterized by being provided at different locations.

[0063] The above circuit section (300) has temperature sensors (first temperature sensor (310) and second temperature sensor (320)) distributed at multiple points, so that minute changes in fluid temperature distribution can be measured in real time, thereby further improving accuracy.

[0064] The above circuit section (300) arranges temperature sensors (first temperature sensor (310) and second temperature sensor (320)) apart so as to measure the temperature of two points within the fluid. This is based on the observation that heat transfer occurs between two points when the fluid flows.

[0065] For example, the first temperature sensor (310) is positioned on the inlet side and the second temperature sensor (320) is positioned on the outlet side. When the fluid is stationary, the temperatures at the two points remain constant, but when the fluid flows, heat moves in one direction and a temperature difference occurs.

[0066] By utilizing this temperature difference (ΔT), it becomes possible not only to determine the presence or absence of fluid flow but also to estimate the flow rate.

[0067] That is, if fluid does not flow, it can be determined that there is no fluid flow due to the lack of a temperature difference between the first temperature sensor (310) and the second temperature sensor (320), and

[0068] When fluid flows, a temperature difference occurs between the first temperature sensor (310) and the second temperature sensor (320), and through this, it can be determined that there is fluid flow.

[0069] In addition, it is possible to indirectly estimate that the flow rate is faster as the temperature difference increases, and the corresponding signal can be quantified and output by the controller (700).

[0071] A controller (700) of a fluid flow and temperature sensing system for an internal combustion engine according to one embodiment of the present invention may be characterized by receiving an analog signal through the thermoelectric elements of the first temperature sensor (310) and the second temperature sensor (320), converting it into a linearized digital signal through a filter, detecting the fluid flow according to the change in temperature, and transmitting it as an output.

[0072] The above controller (700) linearizes the signal and determines the fluid state through filtering and calculation.

[0073] To explain the signal processing process in more detail, when the temperature sensors (first temperature sensor (310) and second temperature sensor (320)) generate an analog signal, the controller (700) receives and filters the analog signal, converts it into a digital signal according to a linearization algorithm, and determines and outputs the fluid flow.

[0074] Temperature sensors (first temperature sensor (310) and second temperature sensor (320)) generally use thermoelectric elements (thermistor, RTD, thermocouple, etc.) and output analog signals such as voltage / resistance changes according to temperature changes.

[0075] Since analog signals are sensitive to external electromagnetic interference (EMI) and noise, removing noise by passing them through a low-pass filter (LPF) or notch filter improves analog signal quality, making it possible to obtain distortion-free data.

[0076] Most temperature sensors have a temperature-resistance relationship that is a non-linear curve (e.g., RTD is S-shaped), and the controller (700) can precisely determine even minute temperature changes by using a mathematical model or a table-based correction algorithm to linearize the non-linear signal.

[0077] Linearized analog signals can be converted into digital signals through an integrated A / D converter or an external ADC chip, and these digital signals can communicate with external systems such as ECUs, PLCs, and control boards.

[0078] The above controller (700) can determine whether there is a flow by calculating the temperature difference (ΔT) between the temperature sensors (first temperature sensor (310) and second temperature sensor (320)).

[0079] For example, if ΔT is greater than a certain value, it can be determined as 'fluid flow present', and if it converges to 0, as 'stagnant'. Depending on the state, it is possible to output a digital flag, generate a warning signal, transmit communication, etc.

[0081] As illustrated in FIG. 2, the circuit section (300) of the fluid flow detection and temperature detection system of an internal combustion engine according to one embodiment of the present invention includes a third temperature sensor (330), and the third temperature sensor (330) may be characterized in that it can measure a wider temperature range than the first temperature sensor (310) and the second temperature sensor (320).

[0082] The first temperature sensor (310) and the second temperature sensor (320) are designed to have a primary function of detecting flow rates based on temperature difference and to respond sensitively within a small temperature range.

[0083] The first temperature sensor (310) and the second temperature sensor (320) are sensors of the same type, but measure at different locations.

[0084] On the other hand, the third temperature sensor (330) is configured to directly measure the actual temperature of the fluid, and requires a temperature sensor with a wide measurement range so that it can operate stably even in extreme high / low temperature environments.

[0085] That is, the first temperature sensor (310) and the third temperature sensor (330) can use temperature sensors with different sensitivities.

[0086] In other words, different temperature sensors can be used that have different resistance values ​​depending on a 1-degree change in the temperature of the thermal resistance.

[0087] Thermal resistance is a major factor in converting a change in temperature into a change in resistance.

[0088] The first temperature sensor (310), the second temperature sensor (320), and the third temperature sensor (330) can be used by alloying various types of thermocouple elements such as platinum, nickel, copper, rhodium, chromium, nickel, and aluminum, which are used as thermocouples or thermocouples.

[0089] A thermocouple is a temperature sensor that utilizes the principle of generating voltage based on the temperature difference at the junction of two types of metals. Thermocouples can be classified into various types, such as K-type, J-type, T-type, E-type, N-type, S-type, R-type, and B-type, depending on the combination of metals used.

[0091] A controller (700) of a fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention may be characterized by receiving an analog signal through a thermoelectric element of the third temperature sensor (330), converting it into a digital signal, and displaying the temperature inside a water tank or pipe.

[0092] That is, the controller (700) can perform the function of converting an analog temperature signal input from the third temperature sensor (330) into a digital signal and displaying / outputting the actual temperature of the internal fluid of the internal combustion engine to the outside.

[0093] The third temperature sensor (330) can use a wide range of thermoelectric elements for measuring high and low temperatures and detects the actual temperature inside the fluid (e.g., 100.2°C) and outputs an analog voltage / resistance signal.

[0094] The above controller (700) converts the analog signal into a digital signal using an A / D converter or the ADC function of an embedded MCU, generates an accurate digital temperature value through a correction and linearization algorithm, and outputs the digital temperature value to an external system such as a display, warning LED, vehicle ECU, or industrial PLC so that it can be used for real-time monitoring or system control.

[0096] As illustrated in FIG. 3, a fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention may include a first port (400) at the rear end of the protrusion (200) that can connect a microchip (MCU) or electronic circuit hardware (H / W) controller capable of converting an analog signal, which is an electrical signal, into a digital signal as a temperature sensor signal.

[0097] The above-mentioned first port (400) is configured to have a connection part (first port (400)) so as to transmit an analog signal output from temperature sensors (310, 320, 330) installed in the sensor part to an external control device (microchip (MCU) or electronic circuit hardware (H / W) controller).

[0098] In other words, it is an I / O interface design structure for reliably electrically connecting the sensor unit and the control unit (microchip (MCU) or electronic circuit hardware (H / W) controller).

[0099] Even if the temperature sensors (310, 320, 330) generate meaningful data, the system cannot operate without a hardware port to reliably transmit this data to a controller (MCU, etc.).

[0100] Accordingly, the present invention provides a physical electrical interface on the sensor side that can be directly connected to a controller, and enables subsequent processing such as analog-to-digital conversion, computation, display, and communication through linkage with a microchip (MCU) or electronic circuit hardware (H / W) controller.

[0102] As illustrated in FIG. 3, a fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention may include a second port (500) at the rear end of the body part (100) that can be connected to the controller (700).

[0103] The second port (500) is implemented as a physical connection port at the rear end of the body part (100) that can be connected to the controller (700).

[0104] That is, it is an I / O interface design structure for electrically and stably connecting the sensor unit and the controller (700).

[0105] Based on the above body part (100), the first port (400) can be an input port and the second port (500) can be an output port.

[0107] As illustrated in FIG. 3, a fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention includes a fourth temperature sensor (910) which is a gas-operated analog thermometer, and may include an analog system unit (900) for measuring the temperature inside a water tank or pipe.

[0108] The analog system unit (900) is a device that supplements the circuit unit (300) or the system connected to the circuit unit (300) to check the temperature inside the water tank or pipe in the event of damage or malfunction.

[0109] For example, the analog system unit (900) is configured so that the state of the fluid can be visually checked through the analog system even when the power is cut off from the outside or a power outage occurs.

[0110] That is, the fluid flow detection and temperature detection system of an internal combustion engine according to one embodiment of the present invention provides a dual safety system that allows the fluid state to be checked even when a sensor fails through the analog system unit (900), and at the same time, can secure an analog auxiliary instrument system to prepare for sensor malfunction.

[0111] Although the primary function of the present invention is a digital temperature and flow rate sensing system, a dual monitoring system including a gas-operated analog thermometer is additionally configured to enable the determination of the fluid state even in the event of digital system abnormalities, such as failure of sensor circuits or electronic components, or communication failure.

[0112] That is, the analog system unit (900) including the fourth temperature sensor (910) operates independently of the digital circuit and is a safety backup sensor system that can visually check the temperature.

[0113] The above analog system unit (900) is a mechanical temperature system that measures temperature using the thermal expansion of gas without using electricity, and includes a stem unit (sensing unit), a capillary tube, and a Bourdon tube in case.

[0114] The stem (sensing part) is the section inserted inside the object (water tank or pipe) to be measured, and it is a space where the enclosed gas expands or contracts in response to actual temperature changes.

[0115] A capillary tube is a long, slender tube connecting the stem and the case (display device); it is filled with the same gas and transmits pressure changes generated in the stem.

[0116] The Bourdon tube in case is a sensor located inside the display case that deforms due to changes in gas pressure, moving a needle (indicator) to display the temperature, and is a mechanically operated structure.

[0117] The above analog system part (900) is filled with inert gas under pressure, and any change in temperature causes a change in pressure inside the measurement system, the changed pressure causes deformation in the Bourdon tube, and the force of the Bourdon tube is transmitted to the pointer of the dial by the movement.

[0119] A controller (700) of a fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention may be characterized by including a surge absorber to protect the internal circuit when an overvoltage is introduced at the power input terminal.

[0120] This is to ensure circuit protection against electrical abnormalities (especially overvoltage) by providing a surge absorber at the input power terminal of the controller (700), which is a core control device of the fluid flow detection and temperature detection system of an internal combustion engine according to one embodiment of the present invention.

[0121] The surge absorber described above is an important protective measure for ensuring the stable operation and lifespan of a fluid flow and temperature sensing system of an internal combustion engine according to an embodiment of the present invention in environments where electrical conditions are poor or where electrical surges (transient voltage) may occur frequently, such as in automobile and marine internal combustion engines and industrial applications.

[0122] A surge absorber is a component connected to the power input terminal of the controller (700) that protects the circuit by diverting the current when a voltage above a certain level is introduced, and may use a varistor, TVS diode, spark gap, etc.

[0123] The surge absorber does not operate when the external power supply is below the rated voltage, but detects when an overvoltage is introduced to the power input terminal due to lightning, inductive surge, starting current, or poor grounding, and absorbs the overcurrent or discharges it to ground, thereby protecting the internal circuit of the controller (700) and ensuring the operational stability of the controller (700).

[0125] A fluid flow and temperature sensing system for an internal combustion engine according to one embodiment of the present invention may be characterized as being used in a tank and flow path of an internal combustion engine system of an automobile or ship, or an industrial fluid control system.

[0126] For example, when installed in a cooling water circulation pipe of an automobile engine cooling system, the body part (100) is attached to the side of the circulation pipe, and the protrusion part (200) is positioned to be inserted into the inside of the circulation pipe, so that the cooling performance is analyzed by detecting changes in temperature and flow rate, thereby preventing overheating, and accurate measurement is possible even while the vehicle is driving thanks to the vibration resistance of the circuit part (300) composed of a flexible printed circuit.

[0127] As another example, when installed in a diesel engine lubricant supply pipe of a large ship, the body part (100) is attached to the outside of the lubricant supply pipe and inserted so that the protrusion (200) is directly exposed to the lubricant flow, thereby preventing bearing overheating / wear and predicting the maintenance time through the detection of the temperature and flow of the lubricant.

[0128] As another example, when installed in an industrial fluid temperature / flow control line such as an industrial heat exchanger outlet pipe or a chemical tank circulation pipe, the body part (100) is connected to a metal pipe or a tank wall and configured so that the protrusion part (200) comes into direct contact with the internal fluid, thereby monitoring basic information to ensure fluid temperature stability and controlling the process flow to prevent overheating.

[0130] A fluid flow detection and temperature detection system for an internal combustion engine according to one embodiment of the present invention, wherein the circuit portion (300) is formed of a multilayer polyimide-based material for miniaturization and vibration resistance.

[0131] A sensor interface with a circuit section (300) in which a temperature sensor is mounted and a signal processing function is implemented, and a multilayer structure, that is, a printed circuit board (ML-FPCB) stacked with two or more layers, is capable of high-density wiring.

[0132] At this time, if the circuit portion (300) is formed from a polyimide-based material, it has excellent heat resistance, chemical resistance, and flexibility, making it suitable for high temperature, high pressure, and high vibration environments.

[0133] Through this, a circuit section (300) capable of responding to an internal combustion engine environment (high temperature, vibration, humidity, oil) can be configured.

[0134] The environment surrounding internal combustion engines, such as automobiles and ships, is completely different from the general circuit environment. Specifically, there are many factors to consider, such as high temperatures (80–150°C or higher), continuous vibration and shock, moisture, oil, the presence of corrosive gases, and the requirement for a confined mounting space (miniaturization is essential).

[0135] Under these conditions, since a general single-layer FPCB is highly likely to fail due to circuit trace disconnection, pad peeling, cracking caused by vibration, etc., it is desirable to apply a multilayer structure + polyimide material to the circuit part (300) to solve this.

[0136] For example, when applied to a cooling water circulation pipe of an automobile engine cooling system, the circuit part (300) is designed as a three-layer laminated structure of a polyimide-based material, so that a temperature sensor (310, 320, 330) is mounted on the upper layer, a filtering circuit and a signal processing IC are mounted on the middle layer, and a power line and a ground layer are mounted on the lower layer.

[0137] It was confirmed that the polyimide-based FPCB is heat resistant to over 200°C and does not have interlayer cracks even with repeated vibration.

[0138] In addition, a protective coating film can be applied to the circuit part (300) to prevent corrosion caused by moisture, cooling water leakage, etc.

[0139] As another example, when installed in the lubricating oil supply pipe of a large ship's diesel engine, the circuit section (300) is inserted into a narrow pipe, so the circuit section is designed to have a width of 12 mm and a thickness of 0.8 mm, and the circuit board is manufactured by laminating a copper circuit on a polyimide film and then forming vias through laser drilling, and a multi-layer GND design for responding to high-frequency noise can be applied.

[0140] As another example, when installed in an industrial boiler, since it is in an environment where it comes into direct contact with high-temperature water, the circuit part (300) can be designed with a polyimide + epoxy hybrid laminated structure so that there is no degradation of the circuit trace even after prolonged exposure to high temperature, and chemical resistance can be secured.

[0143] The present invention is not limited to the embodiments described above, and its scope of application is diverse. Furthermore, it is understood that various modifications are possible without departing from the essence of the invention as claimed in the claims. Explanation of the symbols

[0145] 100: Body part 200: Protrusion 300: Circuit section 310: 1st temperature sensor 320: 2nd temperature sensor 330: Third temperature sensor 400: 1st port 500: 2nd port 700: Controller 900: Analog System 910: 4th temperature sensor

Claims

Claim 1 A fluid flow detection and temperature detection system for an internal combustion engine comprises: a body portion (100) coupled to a tank or pipe to be used to measure fluid flow and temperature; a protrusion portion (200) protruding forward from the body portion (100) and positioned so that the protruding portion is exposed to the fluid inside the tank or pipe to be used to measure fluid flow and temperature; a circuit portion (300) formed integrally with a plurality of temperature sensors, including a first temperature sensor (310) positioned on the inlet side and a second temperature sensor (320) positioned on the outlet side, which surround the outer periphery of the protrusion portion (200), and composed of a flexible printed circuit; and a controller (700) that detects fluid flow and measures temperature based on a signal received from the temperature sensor of the circuit portion (300). A fluid flow and temperature sensing system for an internal combustion engine, comprising: a controller (700) that receives an analog signal through the thermoelectric elements of the first temperature sensor (310) and the second temperature sensor (320), converts it into a linearized digital signal through a filter, calculates the temperature difference (ΔT) between the first temperature sensor (310) and the second temperature sensor (320), determines whether there is fluid flow according to the change in the temperature difference (ΔT), and transmits it as an output; and includes a surge absorber to protect the internal circuit when an overvoltage is introduced to the power input terminal. Claim 2 delete Claim 3 delete Claim 4 A fluid flow detection and temperature detection system for an internal combustion engine, wherein, in claim 1, the circuit portion (300) includes a third temperature sensor (330), and the third temperature sensor (330) is capable of measuring a wider temperature range than the first temperature sensor (310) and the second temperature sensor (320). Claim 5 In claim 4, the controller (700) receives an analog signal through the thermoelectric element of the third temperature sensor (330), converts it into a digital signal, and displays the temperature inside the tank or pipe, thereby forming a fluid flow detection and temperature detection system for an internal combustion engine. Claim 6 In claim 1, the fluid flow detection and temperature detection system of the internal combustion engine comprises a first port (400) at the rear end of the protrusion (200) capable of connecting a microchip (MCU) or electronic circuit hardware (H / W) controller capable of converting an analog signal, which is an electrical signal, into a digital signal as a temperature sensor signal. Claim 7 In claim 1, the fluid flow detection and temperature detection system of the internal combustion engine comprises a second port (500) at the rear end of the body part (100) that can be connected to the controller (700). Claim 8 In claim 1, the fluid flow detection and temperature detection system of the internal combustion engine comprises a fourth temperature sensor (910) which is a gas-operated analog thermometer, and an analog system unit (900) for measuring the temperature inside a tank or pipe.

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