JP2011085451A - Liquid level detection device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid level detection device with decrease in liquid level detection accuracy controlled, and to provide a method of manufacturing the device. <P>SOLUTION: The liquid level detection device for detecting the height of the liquid level detects the liquid level, by detecting the fluctuation in the electrical signal output from an angle detection section, accompanying the fluctuation of the magnetic flux density, when a float moves vertically corresponding to the fluctuation of the liquid level; a rotating section rotates with the vertical movement; and the direction of the magnetic flux of a magnet applied to the angle detection section fluctuates with the rotation, wherein the angle detection section is arranged in a closed area constituted of an inner wall surface of a bottomed cylindrical storage section and a protection section. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid level detection device that detects the height of a liquid level, and a method for manufacturing the same.

  Conventionally, for example, as shown in Patent Document 1, a main body, a float that floats on a liquid surface, a rotating part that can rotate with respect to the main body, and a rotating part and a float are connected to perform vertical movement of the float. An arm that converts the rotational movement of the rotating part, a magnet built in the rotating part, a Hall IC that is built in the main part and detects the rotation angle of the rotating part relative to the main part by measuring the magnetic flux density of the magnet; Has been proposed. In addition to the above-described components, the liquid level detection device includes a plurality of terminals electrically connected to the Hall IC, and a holder that integrally holds the plurality of terminals and stores the Hall IC. .

JP 2008-14917 A

  By the way, in the liquid level detection apparatus shown in Patent Document 1, the holder has a bottomed cylindrical case that accommodates the Hall IC, and the Hall IC is accommodated in the hollow of the case. Then, the holder is insert-molded in the main body with the case opening opened. Therefore, at the time of insert molding, the thermoplastic resin forming the main body portion flows into the hollow of the case, and the thermoplastic resin and the Hall IC are in direct contact with each other. As a result, the Hall IC receives the heat of the thermoplastic resin, and the performance of the Hall IC may be degraded. Thereby, there exists a possibility that a liquid level detection accuracy may fall.

  In view of the above problems, an object of the present invention is to provide a liquid level detection device in which a decrease in liquid level detection accuracy is suppressed, and a manufacturing method thereof.

  In order to achieve the above-mentioned object, the invention according to claim 1 is a float that floats on a liquid surface, a rotating part in which a magnet is built, a float and a rotating part are connected, and a float caused by fluctuations in the liquid level. An angle detection unit that detects the rotation angle of the rotation unit based on fluctuations in the application direction of the magnetic flux density of the magnet accompanying the rotation of the rotation unit and the arm that converts the vertical movement of the rotation unit into the rotation motion of the rotation unit There are a plurality of terminals that electrically connect the section and the outside, a holder that integrally holds the terminals and reinforces the strength of the terminal, an angle detection section, a terminal, and a mold member that covers the holder. And a main body part rotatably provided with a rotating part, wherein the holder has a holding part that integrally holds a plurality of terminals, and a bottomed cylindrical shape that opens at one end. And that And a storage part for storing the angle detection part in the hollow, and in the hollow of the storage part, in addition to the angle detection part, a protection part for protecting the angle detection part from heat during molding of the mold member is provided. The angle detection unit is arranged in a closed region constituted by at least a part of the protection unit and the storage unit.

  Thus, in the present invention, the angle detection unit is arranged in the closed region. According to this, since it is suppressed that the heat at the time of shaping | molding of a mold member acts on an angle detection part directly, the fall of the performance by the heat reception of an angle detection part is suppressed. As a result, a decrease in liquid level detection accuracy is suppressed.

  Moreover, since the angle detection part is arrange | positioned in the obstruction | occlusion area | region, it is suppressed that the injection pressure at the time of injection-molding a mold member is directly applied to an angle detection part. As a result, it is possible to suppress mechanical damage or fluctuations in electrical characteristics of the angle detection unit.

  According to a second aspect of the present invention, it is preferable that the constituent material of the protection part is a liquid member, the closed region is filled with the protection part, and the angle detection part is embedded in the protection part. According to this, the arrangement position of the angle detection unit is determined by the protection unit.

  The liquid member is preferably a resin mainly containing an ultraviolet curable resin as described in claim 2. For example, when the liquid member is a thermosetting resin, heat must be applied to the liquid member in order to solidify the liquid member. Since the heat applied to the liquid member is transmitted to the angle detection unit embedded in the liquid member, there is a possibility that the performance of the angle detection unit is deteriorated by this heat. On the other hand, in the invention described in claim 3, a resin mainly containing an ultraviolet curable resin is applied as the liquid member. Therefore, unlike the case where the liquid member is a thermosetting resin, it is not necessary to apply heat to the liquid member in order to solidify the liquid member. Thereby, when solidifying liquid resin, it is suppressed that a heat is applied to an angle detection part, and the fall of the performance of the angle detection part by heat reception is suppressed.

  As described in claim 2, when all of the angle detection unit is embedded in the protection unit, a semiconductor chip can be employed as the angle detection unit as described in claim 4. According to this, an increase in the physique of the angle detection unit is suppressed as compared with a mold IC in which the angle detection unit is packaged with resin or the like. Thereby, the increase in the physique of a liquid level detection apparatus is suppressed.

  According to a fifth aspect of the present invention, it is preferable that the electrical connection portion between the angle detection unit and the terminal is disposed in the closed region. According to this, it is suppressed that the electrical connection failure arises in an angle detection part and a terminal by the injection pressure at the time of injection-molding a mold member.

  According to a sixth aspect of the present invention, it is preferable that the main body has a protective element that electrically protects the angle detector. As the protective element, as described in claim 7, at least one of a capacitor for suppressing a high voltage from being applied to the angle detection unit and a register for suppressing an overcurrent from flowing to the angle detection unit. The structure which has can be employ | adopted. According to this, at least one of electrical damage due to the high voltage pulse and electrical damage due to overcurrent can be suppressed by the protection element from occurring in the angle detection unit.

  As a configuration for electrically protecting the angle detection unit, for example, as described in claim 8, the terminal includes a ground terminal connected to the ground, a power supply terminal connected to the power source, and an output signal of the angle detection unit. And a signal terminal that outputs to the outside, and the protection element has a capacitor that suppresses application of a high voltage to the angle detection unit, and the capacitor is electrically connected at one end to the ground terminal and the other. A configuration is adopted that includes a first capacitor having one end electrically connected to the signal terminal, and a second capacitor having one end electrically connected to the ground terminal and the other end electrically connected to the power supply terminal. be able to. According to this, before the high voltage pulse generated at the power supply terminal or the signal terminal is applied to the angle detection unit, the above-described high voltage pulse can be discharged to the ground via the capacitor and the ground terminal. .

  In addition, you may mount a liquid level detection apparatus in a vehicle as described in Claim 9.

  Since the operational effect of the invention described in claim 10 is the same as that of the invention described in claim 1, the description thereof is omitted.

  Since the operational effect of the invention described in claim 11 is the same as that of the invention described in claim 2, the description is omitted.

It is a front view which shows schematic structure of the liquid level detection apparatus which concerns on 1st Embodiment. It is sectional drawing which follows the II-II line | wire shown in FIG. It is an expanded sectional view of a main part. It is a top view for demonstrating a holder. It is sectional drawing which shows the modification of a main-body part.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which a liquid level detection device according to the present invention is applied to a fuel level gauge that detects the level of fuel in a fuel tank of a vehicle will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a front view illustrating a schematic configuration of the liquid level detection device according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line II-II shown in FIG. FIG. 3 is an enlarged cross-sectional view of the main body. FIG. 4 is a plan view for explaining the holder. In FIG. 4, for the sake of convenience, protective parts 61 and 62, which will be described later, and a mold member 45 are omitted.

  As shown in FIGS. 1 and 2, the liquid level detection device 100 includes a float 10, a rotating unit 20, an arm 30, and a main body 40 as main parts.

  The float 10 has a specific gravity that floats on the liquid surface X2 of the fuel X1. The float 10 according to the present embodiment has a cylindrical shape, and one end of the arm 30 is inserted into the hollow, and is connected to the arm 30.

  The rotating part 20 contains the magnet 21 and is rotatably provided on a mold member 45 (main body part 40) described later. The rotating portion 20 includes a hollow cylindrical portion 22 and a fitting portion 23 provided on the back surface of the cylindrical portion 22 facing the first covering portion 45a that is a component of the mold member 45. A ring-shaped magnet 21 is built in the cylindrical portion 22, and the other end of the arm 30 is fitted to the fitting portion 23.

  The arm 30 mechanically connects the float 10 and the rotating unit 20. When the float 10 moves up and down as the liquid level X2 fluctuates, this up and down movement is transmitted to the rotating unit 20 via the arm 30, and the rotating unit 20 rotates relative to the main body 40. When the rotating part 20 rotates, the magnet 21 also rotates with the rotation, and the application direction of the magnetic flux density formed in the hollow of the cylindrical part 22 varies. As shown in FIG. 2, the angle detection unit 41 to be described later is disposed in the hollow of the cylindrical portion 22, so that the rotation unit 20 rotates (the vertical movement of the float 10 due to the fluctuation of the liquid level X <b> 2). The application direction of the magnetic flux density applied to the detection unit 41 varies.

  As shown in FIG. 3, the main body 40 includes an angle detection unit 41 that detects the rotation angle of the rotation unit 20 based on a change in the application direction of the magnetic flux density of the magnet 21 as the rotation unit 20 rotates, A protection element 42 that electrically protects the angle detection unit 41; a plurality of terminals 43 that electrically connect the protection element 42 and the angle detection unit 41; and electrically connect the angle detection unit 41 and the outside; The holder 44 that integrally holds the plurality of terminals 43 and reinforces the strength of the terminals 43, and the angle detection unit 41, the protection element 42, the terminal 43, and the mold member 45 that covers the holder 44.

  The angle detection unit 41 includes a Hall element (not shown) that outputs an electrical signal corresponding to a change in magnetic flux density accompanying rotation of the rotating unit 20 (magnet 21), and an amplification element (not shown) that amplifies the output signal of the Hall element. (Not shown). The angle detection unit 41 is a semiconductor chip (bare chip), and pads (not shown) formed on the surface of the semiconductor chip and corresponding leads 41a to 41c are electrically connected.

  The protection element 42 is also a semiconductor chip, and has two chip capacitors 42a and 42b as shown in FIG. These chip capacitors 42 a and 42 b function to suppress application of high voltage pulses to the angle detection unit 41.

  As shown in FIG. 4, the terminal 43 includes a power supply terminal 43 a connected to the power supply, a ground terminal 43 b connected to the ground, and a signal terminal 43 c that outputs an output signal of the angle detection unit 41 to the outside. . Each of these three terminals 43a to 43c is mechanically and electrically connected to the angle detection unit 41 via leads 41a to 41c. The power terminal 43a is connected to the power lead 41a, the ground terminal 43b is connected to the ground lead 41b, and the signal terminal 43c is connected to the signal lead 41c. The power terminal 43a is connected to one end of the first chip capacitor 42a, the ground terminal 43b is connected to the other end of the first chip capacitor 42a and one end of the second chip capacitor 42b, and the signal terminal 43c is connected to the second chip capacitor 42b. Is connected to the other end. Thus, since the power supply terminal 43a and the ground terminal 43b are electrically connected via the first chip capacitor 42a, the high voltage pulse transmitted through the power supply terminal 43a and caused by the fluctuation of the power supply voltage. And a high-voltage pulse caused by static electricity can be discharged to the ground through the first chip capacitor 42a. Further, since the ground terminal 43b and the signal terminal 43c are electrically connected via the second chip capacitor 42b, a high voltage pulse caused by static electricity transmitted via the signal terminal 43c is applied to the second chip. It can be discharged to the ground via the capacitor 42b. The terminals 43a to 43c and the leads 41a to 41c are mechanically and electrically connected by caulking or welding, and the terminals 43a to 43c and the chip capacitors 42a and 42b are mechanically connected via solder (not shown). Connected electrically and electrically.

  As shown in FIGS. 3 and 4, the holder 44 includes a holding portion 44 a that integrally holds the three terminals 43 a to 43 c and a storage portion 44 b that stores the angle detection unit 41. The holding part 44a has a rectangular shape along which the longitudinal direction of each of the terminals 43a to 43c and the longitudinal direction of the terminal 43a itself, and a recess 60 is formed in a part of which the surface of each of the terminals 43a to 43c is exposed. Has been. The bottom surface of the recess 60 is formed by the holding portion 44a and the terminals 43a to 43c, and the side surface of the recess 60 is formed by the holding portion 44a. In the recess 60, the protection element 42, solder (not shown) for mechanically and electrically connecting the protection element 42 and the terminals 43 a to 43 c, and the solder are protected from heat during molding of the mold member 45. A first protection unit 61 is provided.

  The storage portion 44b is open to one end side of the terminals 43a to 43c and has a bottomed cylindrical shape in which the axial direction is perpendicular to the terminals 43a to 43c. As shown in FIGS. 2 to 4, the angle detection unit 41 is stored in a hollow formed by the storage unit 44 b, and all of the angle detection unit 41 is embedded in the second protection unit 62. In the present embodiment, in addition to the angle detection unit 41, leads 41a to 41c and one ends of the terminals 43a to 43c are provided in the hollow of the storage unit 44b, and the hollow of the storage unit 44b is the second protection unit. By being completely filled with 62, the electrical connection portion between the angle detection unit 41 and the terminals 43 a to 43 c is also embedded in the second protection unit 62. In addition, the area | region comprised by the site | part by the side of the opening end of the accommodating part 44b in the 2nd protection part 62 and the inner wall face of the accommodating part 44b is equivalent to the obstruction | occlusion area | region as described in a claim. The electrical connection parts between the angle detection unit 41 and the terminals 43a to 43c are the connection parts between the angle detection unit 41 and the leads 41a to 41c, the leads 41a to 41c, and the leads 41a to 41c and the terminals 43a to 43c. It is a connection site | part with 43c.

  The mold member 45 covers a first covering portion 45a that covers a portion of the terminals 43a to 43c excluding a portion that is electrically connected to the outside, and a first portion that covers the outer surface of the storage portion 44b in which the angle detection portion 41 is stored. 2 covering portion 45b. The first covering portion 45a has a flat plate shape along which the longitudinal direction of the holding portion 44a and the longitudinal direction of the first covering portion 45a are aligned, and the second covering portion 45b is aligned with the axial direction of the storage portion 44b and the axial direction of itself. It has a cylindrical shape. The diameter of the second covering portion 45b is shorter than the inner diameter of the cylindrical portion 22 such that the cylindrical portion 22 (rotating portion 20) can rotate with respect to the second covering portion 45b (main body portion 40). The axial length of the second covering portion 45b is longer than the axial length of the cylindrical portion 22 to the extent that a retaining ring 45c that prevents the cylindrical portion 22 from falling off the second covering portion 45b can be mounted. ing. A ring-shaped groove portion 45d is formed on the outer periphery of the second covering portion 45b exposed to the outside when the cylindrical portion 22 is inserted into the second covering portion 45b, and the above-described retaining ring is formed in the groove portion 45d. 45c is attached.

  Next, the principle of detecting the height of the liquid level X2 of the liquid level detection apparatus 100 according to the present embodiment will be described. As shown in FIG. 2, the angle detection unit 41 is disposed in the hollow of the tube part 22 so that the magnetic flux density of the magnet 21 built in the tube part 22 is applied to the angle detection unit 41. . Accordingly, the float 10 moves up and down as the liquid level X2 fluctuates, and the rotating part 20 rotates along with the up-and-down movement, and the magnet 21 formed in the hollow of the cylindrical part 22 accompanies the rotating movement. When the application direction of the magnetic flux density varies, the magnetic flux density applied to the Hall element of the angle detection unit 41 varies. Since the Hall element is a magnetoelectric conversion element that converts the fluctuation of the magnetic flux density applied to itself into the fluctuation of the electric signal, the fluctuation of the liquid level X2 is converted into the fluctuation of the electric signal output from the Hall element. The electric signal depending on the height of the liquid level X2 output from the Hall element is amplified by the amplifying element, and the amplified electric signal is output to the outside through the signal terminal 43c. The signal terminal 43c is connected to a microcomputer (not shown), and this microcomputer operates a fuel gauge (not shown) mounted on the vehicle based on the detected electrical signal.

  Next, the manufacturing method of the main-body part 40 which concerns on this embodiment is demonstrated. First, terminals 43a to 43c are arranged in parallel in a mold for injection-molding the holder 44 so that the respective surfaces are flush with each other. Then, the molten thermoplastic resin is press-fitted into the mold, and the thermoplastic resin is cooled and solidified. Thus, the holder 44 is formed, and the terminals 43a to 43c are integrally held by the holder 44, so that the recess 60 is formed. The above is the holder forming step.

  After completion of the holder forming process, the angle detection unit 41 to which one end of each of the leads 41a to 41c is connected is disposed in the hollow of the storage unit 44b, and the other end of each of the leads 41a to 41c is connected to the corresponding terminal 43a to 43c. And mechanically and electrically connected. The above is the connection process.

  After the connection process is completed, chip capacitors 42 a and 42 b are mounted on the bottom surface of the recess 60. At that time, one end of the first chip capacitor 42a and the power terminal 43a are connected by solder, the other end of the first chip capacitor 42a and the ground terminal 43b are connected by solder, and one end of the second chip capacitor 42b and the ground. The terminal 43b is connected by solder, and the other end of the second chip capacitor 42b and the signal terminal 43c are connected by solder. The above is the mounting process.

  After the mounting process is finished, a liquid member mainly containing an ultraviolet curable resin is injected into the hollows of the recess 60 and the storage portion 44b. In the present embodiment, all of the solder, all of the protection elements 42, all of the angle detection units 41, and the angle detection units 41 are injected by injecting until the hollows of the recesses 60 and the storage units 44b are filled with the liquid member. And electrical connection portions between the terminals 43a to 43c are embedded in the liquid member. After injecting the liquid member, the liquid member is solidified by irradiating the liquid member with ultraviolet rays to form the protective portions 61 and 62. The above is the protective part forming step.

  After the protection part forming step, the terminals 43a to 43c integrally held by the holder 44 are arranged in a mold for injection molding the mold member 45. Then, the molten thermoplastic resin is pressed into the mold, and the thermoplastic resin is cooled and solidified. Thereby, the mold member 45 in which the terminals 43a to 43c are inserted is molded. The above is the insert molding process.

  Through the above steps, the main body 40 according to the present embodiment is formed. In order to form the liquid level detection device 100 according to the present embodiment, first, the float 10 and the rotating unit 20 are connected via the arm 30. Next, the hollow of the cylindrical portion 22 of the rotating portion 20 is inserted into the second covering portion 45 b of the mold member 45. Finally, a retaining ring 45c that prevents the rotating portion 20 from falling off the mold member 45 is attached to the groove portion 45d. As described above, the liquid level detection device 100 according to the present embodiment is formed.

  Next, the effect of the liquid level detection apparatus 100 according to the present embodiment will be described. As described above, all of the angle detection unit 41 is embedded in the second protection unit 62. According to this, since the heat at the time of molding of the mold member 45 is suppressed from directly acting on the angle detection unit 41, the performance deterioration due to the heat reception of the angle detection unit 41 is suppressed. As a result, a decrease in liquid level detection accuracy is suppressed.

  Further, since all of the angle detection unit 41 is embedded in the second protection unit 62, it is possible to suppress the injection pressure when the molding member 45 is injection-molded from being directly applied to the angle detection unit 41. As a result, mechanical damage to the angle detector 41 and fluctuations in electrical characteristics are suppressed.

  Furthermore, since all of the angle detection unit 41 is embedded in the second protection unit 62, as shown in the present embodiment, the liquid level detection device 100 is connected to the level of the fuel in the fuel tank of the vehicle. Even when applied to a fuel level gauge that detects the height, mechanical damage to the angle detection unit 41 due to external forces caused by vibrations of the vehicle or other causes is suppressed.

  In the present embodiment, an electrical connection portion between the angle detection unit 41 and the terminals 43 a to 43 c is embedded in the second protection unit 62 by the second protection unit 62. According to this, it is suppressed that the electrical connection defect arises in the angle detection part 41 and the terminals 43a-43c by the injection pressure at the time of carrying out the injection molding of the mold member 45. FIG.

  In the present embodiment, a liquid member mainly containing an ultraviolet curable resin is employed as a constituent material of the second protection part 62. For example, when the liquid member is a thermosetting resin, heat must be applied to the liquid member in order to solidify the liquid member (to form the second protective part 62). Since the heat applied to the liquid member is transmitted to the angle detection unit 41 via the liquid member, there is a possibility that the performance of the angle detection unit 41 is deteriorated by this heat. On the other hand, in the present embodiment, a liquid member mainly containing an ultraviolet curable resin is adopted as a constituent material of the second protection part 62. Accordingly, when the liquid member is solidified, it is not necessary to apply heat to the liquid member, so that the angle detection unit 41 is prevented from generating heat, and the deterioration of the performance of the angle detection unit 41 is suppressed.

  The angle detection unit 41 according to the present embodiment is a semiconductor chip. According to this, compared with the case where the angle detection part 41 is packaged with resin etc., the increase in the physique of the angle detection part 41 is suppressed. Thereby, increase of the physique of the liquid level detection apparatus 100 is suppressed.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the present embodiment, after the liquid member is filled in the hollow of the storage portion 44b, the angle detection unit 41 is embedded in the second protection unit 62 by solidifying the liquid member, so that the angle detection unit 41 and the mold member 45 are embedded. A configuration example in which direct contact with the thermoplastic resin, which is a constituent material, is suppressed is shown. However, for example, as shown in FIG. 5, a configuration in which a solid second protection part 62 is arranged at the opening end of the storage part 44 b so as to form a closed region for storing the angle detection part 41 can also be adopted. . Also by this, it is suppressed that the angle detection part 41 and the mold member 45 contact directly. FIG. 5 is a cross-sectional view showing a modification of the main body.

  In the present embodiment, an example in which the hollow of the storage portion 44b is injected until it is filled with the liquid member in the protection portion forming step has been described. However, since all of the angle detection unit 41 is embedded in the liquid member and the angle detection unit 41 only needs to be covered and protected by the second protection unit 62, as shown in the present embodiment, the hollow portion of the storage unit 44b is used. May not be filled with the liquid member.

  In the present embodiment, the example in which the constituent material of the first protective part 61 and the constituent material of the second protective part 62 are the same is shown. However, the constituent material of the first protection part 61 and the constituent material of the second protection part 62 may be different.

  In this embodiment, the example in which the constituent material of the protection parts 61 and 62 is a liquid member mainly containing an ultraviolet curable resin has been shown. However, the constituent material of the protection parts 61 and 62 is not limited to the above example, and for example, a low-temperature curable thermosetting resin or a hot melt can be used.

  In the present embodiment, the angle detection unit 41 is a semiconductor chip, and an example is shown in which the pads formed on the surface of the semiconductor chip and the leads 41a to 41c are electrically connected. However, the angle detector 41 is a semiconductor chip, the angle detector 41 is mounted on the ground terminal 43b, and the pad of the angle detector 41 and the power terminal 43a, and the pad of the angle detector 41 and the signal terminal 43c are each a wire. It is also possible to adopt a configuration electrically connected via the. Alternatively, the angle detection unit 41 includes a semiconductor chip, a plurality of lead frames electrically connected to the semiconductor chip by wires, and an insulating holding plate (ceramic plate) that holds the semiconductor chip and the lead frame. It is also possible to adopt a configuration in which the corresponding leads 41a to 41c are electrically connected to each lead frame.

  In this embodiment, the protection element 42 has shown the example which has chip capacitor 42a, 42b. However, the configuration of the protection element 42 is not limited to the above example, and for example, a configuration in which the protection element 42 includes a chip capacitor and a chip register may be employed. According to this, the angle detection part 41 can be protected from a high voltage pulse and an overcurrent.

  In the present embodiment, the example in which the liquid member is irradiated with ultraviolet rays after the liquid member has been injected in the protective part forming step has been described. However, ultraviolet rays may be irradiated when the liquid member is injected.

  In this embodiment, the liquid level detection apparatus 100 which concerns on this invention showed the example applied to the fuel level gauge which detects the liquid level height of the fuel in the fuel tank of a motor vehicle. However, the application of the liquid level detection device 100 according to the present invention is not limited to the above example, and can be applied to, for example, a liquid level detector in a liquid capacity machine included in a consumer device.

DESCRIPTION OF SYMBOLS 10 ... Float 20 ... Rotation part 21 ... Magnet 30 ... Arm 40 ... Main body part 41 ... Angle detection part 60 ... Concave part 61 ... 1st protection part 62 ... Second protection unit 100 ... Liquid level detection device

Claims (11)

A float floating on the liquid surface,
A rotating part with a built-in magnet;
An arm for connecting the float and the rotating part to convert the vertical movement of the float due to a change in liquid level into a rotational movement of the rotating part;
An angle detection unit that detects a rotation angle of the rotation unit based on a change in an application direction of the magnetic flux density of the magnet accompanying the rotation of the rotation unit, and a plurality of electrical connections between the angle detection unit and the outside A terminal, a holder that integrally holds the plurality of terminals and reinforces the strength of the terminal, and an angle detection unit; a mold member that covers the terminal and the holder; and the rotating unit rotates. A liquid level detection device comprising a main body portion movably provided,
The holder includes a holding unit that integrally holds the plurality of terminals, a bottomed cylindrical shape that opens at one end, and a storage unit that stores the angle detection unit in the hollow thereof.
In the hollow of the storage part, in addition to the angle detection part, a protection part that protects the angle detection part from heat during molding of the mold member is provided,
The liquid level detection device according to claim 1, wherein the angle detection unit is disposed in a closed region constituted by at least a part of the protection unit and the storage unit. The constituent material of the protective part is a liquid member,
The liquid level detection device according to claim 1, wherein the closed region is filled with the protection unit, and the angle detection unit is embedded in the protection unit.   The liquid level detection device according to claim 2, wherein the liquid member is a resin containing an ultraviolet curable resin.   The liquid level detection device according to claim 2, wherein the angle detection unit is a semiconductor chip.   The liquid level detection device according to claim 1, wherein an electrical connection portion between the angle detection unit and the terminal is disposed in the closed region.   The liquid level detection device according to claim 1, wherein the main body portion includes a protection element that electrically protects the angle detection unit.   The protective element includes at least one of a capacitor that suppresses application of a high voltage to the angle detection unit, and a resistor that suppresses an overcurrent from flowing through the angle detection unit. Item 7. The liquid level detection device according to Item 6. The terminal includes a ground terminal connected to a ground, a power terminal connected to a power source, and a signal terminal that outputs an output signal of the angle detection unit to the outside,
The protective element has a capacitor that suppresses application of a high voltage to the angle detection unit,
The capacitor has one end electrically connected to the ground terminal and the other end electrically connected to the signal terminal, one end electrically connected to the ground terminal, and the other end connected to the ground terminal. The liquid level detection device according to claim 7, further comprising: a second capacitor electrically connected to the power supply terminal.   It mounts in a vehicle, The liquid level detection apparatus of any one of Claims 1-8 characterized by the above-mentioned. A method for manufacturing a liquid level detection device according to claim 1,
In the state where the terminal is integrally held by the holder, the angle detection unit is disposed in the hollow of the storage unit, and the angle detection unit and the terminal are electrically connected,
A protective part forming step of forming the protective part so as to constitute the closed region;
After completion of the protective part forming step, when injection molding the mold member, a plurality of terminals integrally held by the holder are arranged in a mold into which a molten thermoplastic resin is press-fitted, and An insert molding step for molding a mold member, and a manufacturing method of a liquid level detection device.   In the protective part forming step, the protective part is formed by injecting a liquid member, which is a constituent material of the protective part, into the hollow so that all of the angle detecting part is embedded, and solidifying the liquid member. The method of manufacturing a liquid level detection device according to claim 10, wherein:

Images