KR100903692B1 - Apparatus for sensing water level for fuel filter of vehicle - Google Patents

Abstract

A water level sensing apparatus for fuel filter of a vehicle is provided to apply an operation signal according to the water level based on the conduction between the sensing rods without grounding through the cartridge. A water level sensing apparatus for fuel filter of a vehicle comprises a body(110) having a protrusion(111) formed upward in the central part, a pair of sensing rods(120) which are installed at an interval on the protrusion of the body, a seal ring(150) which is installed to surround the peripheral part of the protrusion of the body, a circuit board(130) combined in the bottom of the sensing rods, and a power line(135) and a connector(131) connected to the circuit board.

Description

Water level detector for automobile fuel filter {APPARATUS FOR SENSING WATER LEVEL FOR FUEL FILTER OF VEHICLE}

The present invention relates to a device for detecting the water level of the fuel filter mounted on the vehicle, and more specifically, it can be used universally regardless of the material and structure of the collecting cartridge, the manufacturing process is simple, but the play around the sensing rod The present invention relates to a water level detection device for an automobile fuel filter that prevents occurrence of oil and leaks.

Generally, fuel for automobiles is refined at refineries and shipped with impurities removed, but contaminants including moisture are often mixed from the outside during storage and transportation. Such contaminants in the fuel cause damage to each component of the fuel pump, the transfer valve, and the injection nozzle. In particular, diesel fuel is likely to contain water due to moisture condensation due to temperature changes, and in the case of an injection engine such as a diesel engine using the same, water contained in the fuel may cause serious damage to the injection system. . In addition, the combustion efficiency is lowered, the fuel economy of the vehicle is lowered and the amount of incomplete exhaust gas generated increases, such as problems occur. Accordingly, diesel engine vehicles are essentially equipped with a fuel filter for removing contaminants, particularly moisture, contained in the fuel.

The fuel filter is installed in the fuel supply line between the fuel tank and the engine to filter water and other impurities in the fuel supplied by the fuel pump. When the fuel filter accumulates water above a certain threshold, the fuel filter may function. You will have to drain the water or replace the fuel filter in a timely manner. To this end, the fuel filter is usually provided with a water level detection device for detecting the water level of the filtered water to indicate when the drainage or replacement of the fuel filter when a certain limit or more.

The old fuel filter level detection device has a structure in which a float with a permanent magnet is installed on the guide shaft with a reed switch, so that the float is moved up and down by the collected water. The water level was detected through the reed switch according to the position change of. However, the water level detecting device having such a structure has a problem such that malfunction occurs due to the external magnetic field of the permanent magnet, and the operation becomes poor due to the deterioration of the magnetic force over time.

In order to solve this problem, the water level detection device (Utility Model Registration No. 313557) as shown in Figure 1 has been filed by the applicant of the present invention. This is installed in the lower portion of the collecting cartridge to collect the filtered water, the fastening portion 12 is coupled to the cartridge is formed in the central portion of the body case 11 is projected upward, the upper portion inside the fastening portion 12 A sensing rod 13 made of metal is embedded to expose the circuit board, and a circuit board 14 connected to the sensing rod 13 is installed inside the body case 11, and the circuit board 14 is installed on the circuit board 14. The power line 15 and the connector 16 connected to the alarm lamp of the vehicle are made of a structure connected.

Through this configuration, when the water level of the water collected inside the cartridge is increased and the water is in contact with the sensing rod 13, the sensing rod 13 is energized with the vehicle body which is grounded through the cartridge and is also grounded. When the sensing rod 13 is grounded as described above, the operating power is applied through the flashing circuit provided in the circuit board 14 to turn on the alarm lamp. Accordingly, there is an advantage that the service life and operation reliability is improved compared to the above-described float type water level sensing device.

However, such a water level detection device, since the sensing rod 13 is made of a structure in which a light signal is applied to the alarm lamp when the sensing rod 13 is energized with the body through the cartridge, the cartridge is made of a conductive metal material, In the case of the structure, it is possible to detect the water level, but when the cartridge is made of another material, for example, synthetic resin material, or when the cartridge and the vehicle body are electrically insulated, there was a disadvantage.

In addition, since the sensing rod 13 is made of a structure that is assembled through the screw coupling to the coupling hole 17 formed in the center of the fastening portion 12, the sensing rod 13 to the body case 11 in the manufacturing process ) Takes a lot of time and effort to combine, there was a disadvantage that water and fuel leak through the gap between the sensing rod 13 and the screw coupling portion of the coupling hole (17). In particular, since the sensing rod 13 and the body case 11 made of different materials shrink and expand differently according to temperature, leakage and leakage are more severe with time of use, and to prevent this, a separate ring such as an O-ring is used. There is a disadvantage in that the manufacturing cost and time is further increased by requiring a sealing means.

The present invention is to solve the problems as described above, by applying the operating signal according to the water level through the energization between the sensing rods without grounding through the cartridge of the vehicle fuel filter that can be used universally to cartridges of various materials and structures It is an object to provide a level sensor.

Another object of the present invention, by inserting the sensing rod into the main body through the insert injection molding to shorten the assembly process and reduce the manufacturing cost, the water level detection of the vehicle fuel filter that does not cause leakage and leakage during use It is an object to provide a device.

The present invention for achieving the above object, the coupling protrusion is coupled to the collecting cartridge of the vehicle fuel filter in the upper portion, the lower body is formed with a receiving groove; A pair of sensing rods installed in parallel to be spaced apart from each other at predetermined engaging portions of the main body, the upper portion of which is exposed to the inside of the cartridge and the lower portion of which is exposed into the receiving groove; A circuit unit installed inside the receiving groove of the main body and connected to a lower portion of the sensing rod to output an operation signal for turning on the warning lamp of the vehicle when both sensing rods are energized by water in the cartridge; Coupling means for connecting the sensing rod and the circuit unit; And a connection means for connecting the circuit unit to the warning lamp power terminal of the vehicle.

In the above-described water level sensing device of the present invention, the main body is made of a resin injection molding, the sensing rod is preferably made of a structure embedded in the main body through the insert injection molding.

In this case, it is more preferable that a knurling portion consisting of a plurality of protrusions and grooves is formed on the surface of the sensing rod at predetermined intervals.

The knurling portion may be formed with an annular protrusion and a groove having a wedge-shaped cross section.

The circuit unit includes a switching transistor between a power input terminal and an output terminal, a resistor and a capacitor are connected in series with the power input terminal, and a timer IC is connected to the connection point between the resistor and the resistor and the connection point between the resistor and the capacitor and applied from the power input terminal. The voltage may be divided and charged to be applied to the bias voltage of the timer IC, and the capacitor may be connected to the sensing rod to form a discharge passage.

In addition, the coupling means is coupled to the circuit board provided with the circuit portion is connected to the circuit portion, and comprises a fastener having an insertion hole through which the sensing rod penetrates and a connection protrusion projecting inwardly into the insertion hole to contact the sensing rod. It is preferable.

In this case, it is preferable that a plurality of connection protrusions of the fixture are provided in each insertion hole, and the distance between each tip is smaller than the diameter of the sensing rod, and configured to be bent in the insertion direction when the sensing rod is coupled.

In addition, the front end portion of the connecting projection is preferably formed to be concave to correspond to the outer surface shape of the sensing rod.

Sealing may be inserted into the coupling protrusion of the main body.

At least one side of the upper and lower surfaces of the sealing is more preferably provided with a leak-proof projection protruding in an annular shape.

In addition, it is preferable that the inside of the receiving groove of the main body is filled with a filler made of a soft synthetic resin material for protecting and insulating the sensing rod and the circuit board.

In addition, the upper end of the coupling protrusion of the main body is preferably provided with a blocking projection protruding upward between the two sensing rods to prevent water remaining between the sensing rods.

According to the present invention as described above has the following advantages.

(1) It is provided with a pair of sensing rods exposed to the inside of the cartridge of the fuel filter, and when the sensing rod is energized by the water collected in the cartridge, it is configured to output the operation signal to the warning lamp of the vehicle, thereby grounding the cartridge to the vehicle body. There is no need to do this has the effect that it is possible to manufacture a cartridge having a more diverse structure and material.

(2) By inserting and inserting the sensing rod together when molding the main body, there is no gap formed around the coupling portion of the sensing rod, thereby preventing leakage of water and oil collected in the cartridge.

(3) By forming the uneven knurled portion on the outer surface of the sensing rod embedded in the main body, it can increase the bonding force between the two and prevent the play caused by the difference in strain due to the temperature change, thereby more effectively suppressing the water and oil leakage of the cartridge. It has an effect.

(4) It is possible to improve the product productivity by reducing the time and effort required for the assembly work by enabling the coupling and connection of the sensing rod by a simple insertion method to the fixture coupled to the circuit board.

(5) As the connecting protrusion is bent in the inserting direction when the sensing rod and the fixture are coupled to each other to maintain a close contact with the sensing rod by the elastic force, there is an effect that the mechanical coupling and electrical connection between the two can be stably maintained. This effect can be further enhanced by concave the tip of the connecting projection to increase the contact area.

(6) By coupling the seal to the engaging projection of the main body, and in particular, forming the leakage preventing projections on the upper and lower surfaces of the seal, leakage and leakage of the cartridge can be prevented more effectively.

(7) Filling the filler inside the receiving groove of the body to block the sensing rod and the circuit board from the outside, there is an effect that can prevent the mechanical and electrical damage of the sensing rod and the circuit board.

(8) By forming the filler into a soft resin material that is flexibly deformed by external force, it is possible to more effectively cushion external impacts and to prevent deformation and damage due to the use of a curable resin such as epoxy.

(9) By forming a blocking protrusion on the upper end of the main body to prevent water from remaining between the sensing rods, there is an effect that can improve the detection reliability by preventing malfunction due to abnormal energization between the sensing rods.

The objects, features and advantages of the present invention described above will become more apparent from the following detailed description. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a perspective view showing an embodiment of a water level detection device for a vehicle fuel filter according to the present invention, Figure 3 is a cross-sectional view showing the main portion of the water level detection device shown in FIG.

As shown in the water level detection apparatus of the present invention, as long as the main body 110, the coupling protrusion 111 is formed upward in the center and the coupling protrusion 111 of the main body 110 are spaced apart from each other by a predetermined interval and installed in parallel. A pair of sensing rods 120, a sealing member 150 inserted to surround the outer periphery of the proximal end of the coupling protrusion 111, a circuit board 130 coupled to the lower portion of the sensing rod 120, and the circuit board. The power line 135 and the connector 131 connected to the 130 are formed.

The main body 110 is a synthetic resin injection molding, a screw portion 112 for coupling with a collecting cartridge (not shown) is formed on the outer circumferential surface of the coupling protrusion 111, the water and oil collected in the cartridge to one side to the outside Discharge holes 115 for discharging are formed in communication with the up and down, the discharge hole 115 is opened and closed by a separate drain plug (not shown). The inner and outer circumference of the upper coupling protrusion 111 of the main body 110 is formed with a seating groove 114 to which the sealing 150 is coupled and a collecting groove 113 communicating with the discharge hole 115, respectively. The lower portion is formed with a receiving groove 116 in which the circuit board 130 is built. The filler 117 for protecting and insulating the sensing rod 120 and the circuit board 130 is filled in the receiving groove 116. The filler 117 is made of an insulating synthetic resin material, for example epoxy resin may be used, it is preferable to use a soft epoxy to prevent deformation and damage of the internal components due to the curing of the epoxy.

In addition, the upper end of the coupling protrusion 111 of the main body 110 is provided with a blocking protrusion 129 which is spaced apart from each sensing rod 120 by a predetermined interval between the sensing rod 120 and protruded upward. The blocking protrusion 129 protrudes higher than the sensing rod 120 so that water does not remain between the sensing rods 120 and flows to the outside, and the water inside the cartridge is shaken during the driving of the vehicle. Prevents water from accumulating between the two sensing rods 120 due to the presence of a small amount of water remaining after swinging or discharging the collected water, so that both sensing rods 120 are energized even when the water level inside the cartridge is low. Prevents

The sealing 150 prevents leakage and leakage by preventing a gap between the coupling portion of the main body 110 and the cartridge, and is made of a soft resin material such as silicone and rubber, and a plurality of protruding annularly on the upper and lower surfaces. Leak prevention protrusion 151 is provided.

The sensing rods 120 are energized with each other through water as the level of the cartridge rises so that an operation signal is applied through the circuit board 130. The sensing rod 120 is made of a conductive metal material. It is formed in the insert injection method in the state embedded in the engaging protrusion 111 of the main body 110. An upper portion of the sensing rod 120 protrudes upward toward the outer side of the coupling protrusion 111 of the main body 110, and a lower portion thereof protrudes downward to penetrate the circuit board 130.

In addition, the outer circumferential surface of the sensing rod 120 is formed with a plurality of knurled portion 121 irregularities at predetermined intervals. The knurling portion 121 is to increase the coupling force between the main body 110 and the sensing rod 120 and to prevent leakage and leakage by preventing a gap between the coupling portions on both sides, as well as the wedge shape as illustrated The protrusions and the grooves of various shapes may be repeatedly formed in the uneven structure.

The circuit board 130 applies an operation signal to the display lamp of the vehicle connected through the connector 131 when the sensing rods 120 are energized with each other. Such a flashing control circuit may be configured in various ways. For example, as shown in FIG. 4, a circuit using a NE555 as a timer IC and a PNP transistor as a switching means may be used.

In the illustrated circuit, a diode D1 for preventing reverse current and a static thermistor (PTC) for preventing overcurrent are connected to the power input terminal (Vcc), and a switching transistor is connected between the thermistor (PTC) and the output terminal (OUT). Q1 is connected. Branched after the thermistor PTC, resistors R1, R2, R3 and capacitor C2 are connected in series, and one of the sensing rods 120 is connected between resistor R1 and resistor R2 and the other One is connected to the ground side at the rear end of the capacitor (C2). The thermistor (PTC) is connected to the power supply terminal 8 and the reset terminal (4) of the timer IC (U1) through the power supply noise removing resistor (R5), the zener diode (D2) for overvoltage protection on the power supply terminal (8) side On the reset terminal 4 side, a capacitor C4 for removing noise generated when the power is temporarily cut off is connected. The trigger terminal 2 of the timer IC U1 is connected between the resistor R3 and the capacitor C2, and the output terminal 3 is connected to the base of the transistor Q1 through the resistor R4. The terminal 5 is connected to the noise removing capacitor C3, the threshold terminal 6 is connected between the resistor R1 and the resistor R2, and the discharge terminal 7 is connected to the rear end of the capacitor C3. Through ground.

The circuit unit configured as described above has a voltage divided and charged through the resistors R1, R2, and R3 and the capacitor C2 applied to the timer IC U1, and the output signal of the timer IC U1 is adjusted. The transistor Q1 is turned on / off by a signal so that the alarm lamp flashes.

The timer IC U1 is a conventional NE555 and includes two comparators COM1 and COM2, a flip-flop, a discharge transistor, and three resistors, as shown in FIG. Three resistors are connected in series between the power supply terminal 8 and the ground terminal 1. The voltage applied to the power input unit Vcc is 1 to the (+) input terminal of the first comparator COM1 and the (-) input terminal of the second comparator COM2 through the resistors R1, R2 and R3 and the capacitor C2. It is divided into / 3 and 2/3, and the trigger terminal 2 is connected to the negative input terminal of the first comparator COM1, and the threshold terminal 6 is connected to the positive input terminal of the second comparator COM2. . Accordingly, when the voltage of the trigger terminal 2 is less than 1 / 3Vcc, the output of the first comparator COM1 is LOW and there is no change in the output of the flip-flop. If the voltage of the threshold terminal 6 is greater than 2/3 Vcc, the output of the second comparator COM2 becomes HIGH, and the R input of the flip-flop becomes HIGH and the output becomes LOW. When the output of the second comparator COM2 becomes LOW, the inverted output becomes HIGH, the discharge transistor is turned on, and discharge is performed through the discharge terminal 7.

As a fastening means for coupling the sensing rod 120 and the circuit board 130, a forced press-fitting fixture 140 using elasticity is provided. 6 is a perspective view of the fixing unit 140 and the sensing rod 120 viewed from below. Referring to Figure 6 together, the fastener 140 has a coupling protrusion 141 is formed at both ends in the longitudinal direction, the insertion hole 142 through which the sensing rod 120 is formed in the center is formed, the insertion hole The connection protrusion 143 which protrudes in the direction opposing each other is provided in the inside of 142. As shown in FIG. The fixture 140 is coupled to the bottom surface of the circuit board 130 through the coupling protrusion 141. A separate means for energizing the sensing rod 120 to the circuit board 130 may be provided, but it is preferable that the sensing rod 120 and the circuit board 130 are energized through the fixture 140. .

A corresponding through hole 131 is formed in the circuit board 130 so that the sensing rod 120 can be inserted into the insertion hole 142 of the fixture 140. Both connecting protrusions 143 of the fixture 140 are formed so that the distance between the tip portion is smaller than the diameter of the sensing rod 120, when connecting the sensing rod 120 to the insertion hole 142, both connecting protrusions 143 ) Is bent in the insertion direction while being in close contact with the outer circumferential surface of the sensing rod 120 is configured to restrain the movement of the sensing rod 120 in the separation direction. At this time, it is preferable that the tip portion of each connection protrusion 143 is formed concave in correspondence with the outer peripheral surface shape of the sensing rod 120 so that a larger fixing force is applied to increase the contact area and the energization state can be maintained well. .

The water level detection device of the present invention configured as described above, the insert injection molding in the state in which the sensing rod 120 is first placed in the mold to mold the main body 110, the inside of the receiving groove 116 of the main body 110 After installing the circuit board 130 to which the power line 135 and the connector 131 are connected, coupled to and energized with the sensing rod 120, the process of filling the filler 117 into the receiving groove 116 is produced. do.

Therefore, the main body 110 and the sensing rod 120 are manufactured in an integrated state through the insert injection, and simply push the sensing rod 120 into the fixture 140 pre-installed on the circuit board 130. Since the fastening and connection are made, the cumbersome process such as the assembly work for inserting the sensing rod into the main body and screwing together, and the connection work for connecting the sensing rod and the circuit board, as in the prior art, are not required. Accordingly, the manufacturing process can be simple and easy to improve the product productivity.

Insert the seal 150 into the coupling protrusion 111 and then combine it with the water collecting cartridge of the fuel filter and connect the connector 131 to the alarm lamp power terminal of the vehicle is completed installation. At this time, the sealing hole of the cartridge is sealed by the sealing 150 to prevent leakage of water and oil collected in the cartridge, and in particular, this effect may be further enhanced by the leak preventing protrusion 151 provided in the sealing 150. Can be.

When the installation is completed as described above, when power is applied, power is temporarily supplied through the circuit board 130 so that a warning lamp of the vehicle is turned on for a while to indicate initial start-up and then to be turned off. In this state, when the level of water collected in the cartridge is high, both sensing rods 120 are energized with each other through the water, whereby the circuit board 130 is operated in a power-on state and the warning lamp is turned on. This informs you when it is time to replace or drain the cartridge.

In this process, the operation of the circuit unit is performed as follows.

Since the capacitor C2 is not charged with charge immediately after the power is input from the power input unit Vcc, the potential of the trigger terminal 2 is 0V. Accordingly, since the first comparator COM1 of the timer IC U1 outputs HIGH and HIGH is input to S of the flip-flop, the output Q becomes HIGH, and the switching transistor connected to the timer IC U1 Warning lamp turns on when Q1) is turned ON.

When the charge is charged in the capacitor C2 and the potential of the trigger terminal 2 exceeds 1/3 Vcc, the output of the second comparator COM2 is changed to LOW. If the flip-flop is LOW, the output (O) remains HIGH and the inverting output (/ O) remains LOW so that the capacitor is charged.

When the potential of the trigger terminal 2 exceeds 2 / 3Vcc, the output of the second comparator COM2 is changed to HIGH, and the flip-flop is reset, the output O is LOW and the inverted output (/ O) is HIGH. And the discharge transistor is turned on. As a result, the charge that has been charged in the capacitor C2 is discharged to the outside. In addition, the switching transistor Q1 is turned off to turn off the alarm lamp.

When the potential of the trigger terminal 2 drops below 2/3 Vcc due to the discharge, the output of COM2 goes back to LOW again, the reset of the flip-flop is released, and the output (O) is in the LOW state, and the inverted output (/ Q) Since the HIGH state is maintained, the discharge transistor maintains the ON state to continue discharging. When the discharge proceeds and the potential of the trigger terminal 2 becomes smaller than 1/3 Vcc, the output of the first comparator COM1 is changed to HIGH, and the output of the flip-flop is changed to HIGH again, and the alarm lamp is turned on again. . In addition, the inversion output (/ Q) becomes LOW so that the discharge transistor is turned off, and the capacitor C2 is charged again. When the capacitor C2 is charged and the potential of the trigger terminal 2 is greater than 1/3 Vcc, the output of the first comparator COMP1 becomes LOW, but the output of the flip-flop remains HIGH and the alarm lamp remains ON. .

This process is repeated until the potential of the trigger terminal 2 becomes 2/3 Vcc so that the potential of the capacitor C2 varies between 1/3 Vcc and 2/3 Vcc, and the output O repeats HIGH and LOW. The alarm lamp blinks.

After lighting, the off state continues until both sides of the sensing rod 120 is energized by water, and the level of water collected in the cartridge is increased so that the two sensing rods 120 are energized with each other by the water, which is charged in the condenser C2. When the charge is discharged to the ground through the sensing rod 120 and the potential of the trigger terminal 2 is lower than 1 / 3Vcc, the first comparator COM1 outputs HIGH and HIGH is input to S of the flip-flop. O) becomes HIGH. Accordingly, the switching transistor Q1 connected to the timer IC U1 is turned on to output a driving signal for turning on the alarm lamp through the output terminal OUT.

As described above, since the water level collected in the cartridge of the fuel filter is displayed through energization of the pair of sensing rods 120, the cartridge is grounded to the vehicle body as in the conventional water level sensing apparatus having one sensing rod. The cartridge can be made of a non-conductive material of various materials such as a synthetic resin as well as a conductive metal, and the structure of the cartridge can also be manufactured in a variety of structures that do not require connection with a vehicle body.

In addition, the pressure and gravity of the inside of the cartridge acts on the collected water, since the sensing rod 120 is inserted into the body 110 and the gap is not formed around the sensing rod 120, the sensing rod as in the prior art The problem of leakage through the inserted coupling holes is eliminated. In addition, by forming the knurled portion 121 in the sensing rod 120, not only the bonding force is increased but also the occurrence of play due to the strain difference due to the temperature change, it is possible to obtain a further improved leakage blocking effect. And, since there is no need for a separate sealing means such as a conventional O-ring, it is possible to reduce the manufacturing cost and further improve productivity.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a cross-sectional view showing a conventional water level sensor for automobile fuel filters.

2 is a perspective view showing the configuration of an embodiment of a water level sensor for a vehicle fuel filter according to the present invention.

3 is a cross-sectional view showing the internal configuration of the water level sensor of the present invention shown in FIG.

4 is a circuit diagram showing the configuration of a circuit unit in the water level sensor of the present invention.

FIG. 5 is a circuit diagram illustrating a configuration of a timer IC in the circuit unit of FIG. 4.

Figure 6 is a perspective view showing the coupling state of the sensing rod and the fixture from the lower side in the water level detection device of the present invention.

<Description of the reference numerals for the main parts of the drawings>

110: main body 111: coupling protrusion

112: screw portion 117: filler

120: detection rod 121: knurled portion

130: circuit board 131: connector

135: power line 140: fixture

141: coupling protrusion 143: connection protrusion

150: sealing 151: leak prevention protrusion

Claims (12)

A main body having a coupling protrusion coupled to a water collecting cartridge of an automobile fuel filter at an upper portion thereof, and having a receiving groove formed at a lower portion thereof; A pair of sensing rods installed in parallel to be spaced apart from each other at predetermined engaging portions of the main body, the upper portion of which is exposed to the inside of the cartridge and the lower portion of which is exposed into the receiving groove; A circuit unit installed inside the receiving groove of the main body and connected to a lower portion of the sensing rod to output an operation signal for turning on the warning lamp of the vehicle when both sensing rods are energized by water in the cartridge; Coupling means for connecting the sensing rod and the circuit unit; And It includes a connecting means for connecting the circuit portion to the warning lamp power terminal of the vehicle, Water level detection for the vehicle fuel filter, characterized in that between the sensing rods of the upper side of the coupling protrusion of the main body is separated from the sensing rods and protruded higher than the sensing rods to prevent water from remaining between the sensing rods. Device. The method of claim 1, The main body is made of a resin injection molding, the sensing rod is a fuel level sensor for an automobile fuel filter, characterized in that embedded in the state integral to the body through the insert injection molding. The method of claim 2, The water level detection device for an automobile fuel filter, characterized in that the knurled portion consisting of a plurality of projections and grooves formed on the surface of the sensing rod at predetermined intervals. The method of claim 3, And said knurling portion is formed with an annular projection and groove having a wedge-shaped cross-sectional shape. delete The method according to any one of claims 1 to 4, The coupling means is coupled to the circuit board provided with the circuit portion is connected to the circuit portion, characterized in that consisting of a fastener having an insertion hole through which the sensing rod penetrates and a connection protrusion projecting inwardly into the insertion hole to contact the sensing rod. Level detection device for automobile fuel filter. The method of claim 6, A plurality of connection protrusions of the fixture is provided in each insertion hole, the distance between each tip portion is formed smaller than the diameter of the sensing rod is bent in the insertion direction when the sensing rod is coupled to the vehicle fuel filter, characterized in that the sensor. The method of claim 6, The front end portion of the connection projection is a car fuel filter water level detection device, characterized in that formed concave to correspond to the outer shape of the sensing rod. The method of claim 6, The water level detection device for an automotive fuel filter further comprises a seal inserted and coupled to the coupling protrusion of the main body. The method of claim 9, At least one side of the upper and lower surfaces of the sealing water level detection device for an automobile fuel filter, characterized in that a plurality of leakage preventing projections protruding annularly provided. The method of claim 6, And a filling material made of a soft synthetic resin material which is filled in the receiving groove of the main body to protect and insulate the sensing rod and the circuit board. delete

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