JP5206202B2 - Liquid level detector - Google Patents

Description

  The present invention relates to a liquid level detection device for detecting a liquid level.

  As the liquid level detection device, for example, an electric resistance type liquid level detection device that detects a change in the liquid level as a change in electric resistance in order to monitor the liquid level position of the fuel stored in the fuel tank of the automobile, and the liquid level A magneto-electric conversion element type liquid level detection device is used that detects this variation by a magneto-electric conversion element as a change in the magnetic flux density of the magnet. These liquid level detection devices are attached to a sub tank in the fuel tank.

  The electric resistance type liquid level detection device includes a main body part, a float floating on the liquid surface, a rotating part rotatable with respect to the main body part, and connecting the float and the rotating part to move the float up and down. An arm that converts the rotational motion of the motor, an electric resistor fixed to the main body, and a sliding contact that is fixed to the rotating unit and that is electrically connected to the electric resistor while sliding on the electric resistor. Prepare. The electrical resistor and the sliding contact are configured such that the electrical resistance changes depending on the sliding position of the sliding contact with respect to the electrical resistor. The electric resistance type liquid level detection device detects the liquid level position of the liquid level by measuring the electric resistance.

  Magnetoelectric conversion element type liquid level detection device rotates the float up and down by connecting the main body, the float floating on the liquid level, the rotating part rotatable with respect to the main body part, and the float and rotating part. An arm that converts the rotational motion of the part, a magnet built in the rotational part, and a magnetoelectric conversion element such as a Hall IC built in the main body so as to intersect the magnetic flux of the magnet. The magnetoelectric conversion element type liquid level detection device detects the liquid level position by measuring the magnetic flux density of a magnet that intersects the magnetoelectric conversion element by the magnetoelectric conversion element.

  Here, since the fuel in the sub tank moves up and down and friction is generated between the sub tank and the fuel, static electricity is generated in the sub tank. In general, since the arm is formed of a conductive material such as metal, the charge due to static electricity moves from the sub tank to the arm via the main body and the rotating part, and accumulates on the arm. When the electric charge accumulated in the arm is discharged from the arm, the liquid level detection signal from the liquid level detection device is disturbed, so that the accuracy of the liquid level detection may be lowered.

In order to suppress the discharge from the arm, in the electric resistance type liquid level detection device, the rotating body is formed of a conductive material, and the charge of the arm is always externally supplied through the conductive rotating body, the sliding contact, and the electric resistor. The structure which escapes is disclosed (patent document 1).
JP 2004-340756 A

  However, in the magnetoelectric conversion element type liquid level detection device, it is not possible to adopt a configuration in which the arm's charge is allowed to escape to the outside through the conductive rotating body, the sliding contact, and the electric resistor, so that the discharge from the arm can be suppressed. Can not.

  The inventor has also found that the charge of the arm can be released to the outside through the fuel in contact with the arm. Therefore, it is sufficient to always let the arm charge escape to the outside only when the liquid level of the fuel is located below the arm.

  The present invention has been made in consideration of such circumstances, and provides a liquid level detection device capable of releasing the charge of the arm to the outside when the liquid level is located below the arm. Objective.

  The present invention employs the following technical means to achieve the above object.

According to the first aspect of the present invention, the main body, the float floating on the liquid surface, the rotating part rotatable with respect to the main body, the float and the rotating part are connected, and the vertical movement of the float is performed by the rotating part. In a liquid level detection device for detecting a liquid level position by detecting a rotation angle of an arm, the arm having conductivity that converts to a rotational motion and a rotation angle detector that detects the rotation angle of the arm. A conductive member electrically connected to the arm , and the conductive member is connected to the arm so as to be rotatable with respect to the arm on the side surface of the float. In the state, the lowest point which is the lowest side of the conductive member is located below the lowest point which is the lowest side of the arm.

According to this configuration, the lowest point of the conductive member electrically connected to the conductive arm is positioned below the lowest point of the arm in the lowest position where the float is located at the lowest side. ing. For this reason, in the lowest position state of the float, when the liquid level is located below the lowest point of the arm, the lowermost point portion of the conductive member can come into contact with the liquid at the liquid level position. This charge can be released to the outside through the conductive member and the liquid. Therefore, when the liquid level is below the arm, the arm charge can be released to the outside .
In addition, since the lowest point portion of the conductive member does not change depending on the vertical position of the float, the conductive member can be connected to the arm without considering the vertical position of the float. Thus, the above-described effects can be obtained while simplifying the connection of the conductive member to the arm.

  According to the invention of claim 2, in the lowest position state, the lowest point of the conductive member is positioned below the lowest point which is the lowest side of the float.

  For this reason, when the liquid level is located below the lowest point of the float in the lowest position state of the float, the portion of the lowest point of the conductive member can come into contact with the liquid at the liquid level position. Can be released to the outside through the conductive member and the liquid. Therefore, when the liquid level is below the float, the arm charge can be released to the outside.

According to invention of Claim 3 , a conductive member has a shape which spreads toward the lowest point of a conductive member from the connection position of a conductive member and an arm, It is characterized by the above-mentioned.

  For this reason, even if external vibration is applied and the conductive member swings with respect to the arm, the distal end side of the end portion of the conductive member becomes the lowest point of the conductive member. It can suppress that a point goes up and down. Therefore, when the liquid level is below the arm, the arm charge can be surely released to the outside.

According to the invention of claim 4 , the rotation angle detector includes a magnet built in the rotating part, and a magnetoelectric conversion element built in the main body so as to intersect the magnetic flux of the magnet, and the rotation of the arm The angle is detected by measuring the magnetic flux density of a magnet that intersects the magnetoelectric conversion element by the magnetoelectric conversion element.

  For this reason, in the magnetoelectric conversion element type liquid level detection device that detects the fluctuation of the liquid level as a change in the magnetic flux density of the magnet by the magnetoelectric conversion element, the above-described effect can be obtained.

According to the invention of claim 5 , the rotation angle detector is slid on the electric resistor while being fixed to the main body and being electrically connected to the electric resistor. In addition, the electrical resistor and the sliding contact are configured such that the electrical resistance varies depending on the sliding position of the sliding contact with respect to the electrical resistor, and the arm rotation angle measures the electrical resistance. It is detected by doing.

  For this reason, the above-mentioned effect can be obtained in the electric resistance type liquid level detection device that detects the fluctuation of the liquid level as a change in electric resistance.

  Hereinafter, a case where the liquid level detection device according to the present invention is applied to a fuel level gauge mounted on an automobile will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the mutually same or equivalent part in a figure.

(First embodiment)
A fuel level gauge 1 shown in FIG. 1 is a magnetoelectric conversion element type fuel level gauge that detects a change in liquid level by a magnetoelectric conversion element as a change in magnetic flux density of a magnet, and is a liquid level of fuel A in a fuel tank (not shown). To detect the position, it is fixed in the fuel tank. 1 and 2, the upper part of the figure shows the upper part in a state where the fuel level gauge 1 is attached to the automobile.

  The float 2 is made of resin or the like, and has an apparent specific gravity so as to surely float on the liquid surface of the fuel A. The arm 3 is formed of a conductive material such as a metal rod, and the float 2 and the rotating unit 4 are connected to each other. Link. When the float 2 moves up and down due to the liquid level fluctuation of the fuel A, this movement is transmitted to the rotating unit 4 by the arm 3 and converted into the rotating motion of the rotating unit 4.

  The liquid level position A1 of the fuel A is almost empty in the fuel tank, and the liquid level position A2 of the fuel A is full. FIG. 1 shows the fuel level gauge 1 in the case of the liquid level position A1, and shows the liquid level position A2 and the float 2 and the arm 3 in the case of the liquid level position A2 with two-dot chain lines. When the liquid level position A1 of the fuel A changes between the liquid level position A1 in the almost empty state and the liquid level position A2 in the full state, the float 2 moves up and down in conjunction with this, and the rotating unit 4 5 is configured to rotate within a predetermined rotation range Θ.

  That is, it can be said that FIG. 1 shows the fuel level gauge 1 in the lowest position in which the float 2 is located on the lowermost side in the vertical movement of the float 2. Further, the liquid level position A1 is located below the lowest point H2 that is the lowest side of the float 2 in the fuel level gauge 1 in the lowest position.

  The rotating part 4 is formed of, for example, resin or the like, and includes a magnet 44 and is rotatably assembled to the main body part 5 as shown in FIG. The rotating part 4 includes a hole 41 and a convex part 43 for assembling the rotating part 4 to the main body part 5 so as to be rotatable, and a holding part 42 for holding and fixing the arm 3.

  For example, the magnet 44 made of a ferrite magnet or the like is a cylindrical one, and is two-pole magnetized as shown in FIG. The magnet 44 is integrally insert-molded at the time of resin molding of the rotating portion 4 and is arranged concentrically with the hole 41. Thereby, the magnetic flux M of the magnet 44 is generated in the radial direction of the hole 41.

  As shown in FIG. 2, the hole portion 41 is formed as a through hole, and the shaft portion 51 of the main body portion 5 is rotatably fitted in the hole portion 41, so that the rotating portion 4 is connected to the main body portion 5. The center of the shaft portion 51 can be turned around the rotation axis. The convex portions 43 and 511 are formed so that the convex portion 43 contacts the convex portion 511 in the rotational axis direction within the above-described rotation range Θ, and the rotational portion 4 is separated from the main body portion 5 (left direction in FIG. 2). ) Is restricted. In this way, the rotating portion 4 is configured so that the shaft portion 51 does not come out of the hole portion 41 within the rotation range Θ described above, and the rotating portion 4 rotates with the center of the shaft portion 51 of the main body portion 5 as the rotation axis. It is possible to move.

  As shown in FIGS. 1 and 2, two holding portions 42 are arranged on the end surface of the rotating portion 4 on the side opposite to the main body portion 5, and the arm 3 is held and fixed to the holding portion 42. The two holding portions 42 are arranged so that the arm 3 held and fixed to the holding portion 42 intersects the rotation axis.

  The main body 5 is formed of an insulating material such as polyphenylene sulfide resin, for example, and rotatably holds the rotating part 4 by the shaft part 51. The main body 5 incorporates a Hall IC 52 as shown in FIG. 2, and a terminal 6 for electrically connecting the Hall IC 52 to the outside is formed integrally with the main body 5 as shown in FIG. The

  The Hall IC 52 is disposed in the shaft portion 51, and the magnet 44 fixed to the rotating portion 4 is disposed concentrically with the shaft portion 51 on the outer peripheral side of the shaft portion 51. Therefore, the Hall IC 52 is built in the main body 5 so as to intersect with the magnetic flux of the magnet 44, and always receives the magnetic flux M of the magnet 44 as shown in FIG.

  The Hall IC 52 includes a Hall element made of a semiconductor (not shown), a preamplifier, and the like. When a magnetic field is applied from the outside while a voltage is applied to the Hall element, the Hall element generates a Hall voltage proportional to the magnetic flux density of the magnetic field passing through the Hall element. This Hall voltage is amplified by a preamplifier or the like and transmitted to the outside through the terminal 6.

  Since the magnetic flux density of the magnetic field passing through the Hall element (Hall IC 52) changes when the rotating unit 4 rotates due to fluctuations in the liquid level positions A1 and A2, the Hall voltage of the Hall element, that is, the output voltage of the Hall IC 52 is Changes according to By detecting the output voltage of the Hall IC 52 (Hall voltage of the Hall element), the rotation angle of the rotating unit 4, that is, the liquid surface positions A1 and A2 can be measured.

  As shown in FIGS. 1 and 2, the liquid surface contact piece 7, which is a feature of the present invention, is electrically connected to the conductive arm 3 in a rotatable manner on the side surface side of the float 2. The liquid level contact piece 7 is formed of a conductive material such as metal, and as shown in FIG. 4, a conductive surface provided with an insertion hole 71 through which the arm 3 is inserted and an extending portion 72 extending from the insertion hole 71. It is formed into a thin plate shape.

  As shown in FIG. 5, the arm 3 is inserted into the insertion hole 71, the tip side of the arm 3 is crushed to form a retaining portion 31, so that the arm 3 and the liquid surface contact piece 7 do not come out of the arm 3. To. In this way, the conductive liquid surface contact piece 7 is electrically connected to the conductive arm 3 so as to be rotatable on the side surface side of the float 2. The insertion hole 71 can be said to be a connection position CP between the liquid surface contact piece 7 and the arm 3.

  As shown in FIGS. 1 and 5, the liquid surface contact piece 7 includes an extension portion 72 extending from the insertion hole 71 and is rotatably connected to the arm 3, so that the tip of the extension portion 72 is provided. However, it always hangs down. For this reason, since the lowest point portion of the liquid level contact piece 7 does not change depending on the vertical position of the float 2, even when the float 2 is in the lowest position, the tip of the extension 72 is the most of the liquid level contact piece 7. The lowest point H1 is the lower side. In the lowest position state of the float 2, the liquid level contact piece 7 has a lowest point H <b> 1 positioned below the lowest point H <b> 3 that is the lowest side of the arm 3, and is further on the lowest side of the float 2. It is formed in a shape located below the lowest point H2.

  The size and weight of the liquid level contact piece 7 are set so that the float 2 is surely floated on the liquid level of the fuel A.

  The fuel level gauge 1 corresponds to the liquid level detection device recited in the claims, the Hall IC 52 corresponds to the magnetoelectric conversion element recited in the claims, and the liquid level contact piece corresponds to the conductive member recited in the claims. The fuel A corresponds to the liquid described in the claims.

  Next, the effect of the fuel level gauge 1 according to the first embodiment of the present invention will be described.

  As described above, in the lowest position state where the float 2 is located on the lowermost side, the lowest point H1 of the liquid surface contact piece 7 is positioned below the lowest point H3 of the arm. For this reason, in the lowest position state of the float 2, since the part of the lowest point H1 of the liquid level contact piece 7 can contact the fuel A at the liquid level position A1 located below the lowest point H3 of the arm 3, The electric charge of the conductive arm 3 can be released to the outside through the conductive liquid surface contact piece 7 and the fuel A. Therefore, when the liquid level position A1 is below the arm 3, the charge of the arm 3 can be released to the outside.

  Furthermore, in the lowest position state where the float 2 is located on the lowermost side, the lowest point H1 of the liquid surface contact piece 7 is positioned below the lowest point H2 of the float. For this reason, in the lowest position state of the float 2, since the part of the lowest point H1 of the liquid level contact piece 7 can contact the fuel A at the liquid level position A1 located below the lowest point H2 of the float, It is possible to release the charge of the conductive arm 3 to the outside through the conductive liquid level contact piece 7 and the fuel A. Therefore, when the liquid level position A1 is below the float 2, the charge of the arm 3 can be released to the outside.

  Further, since the liquid level contact piece 7 is rotatably connected to the arm 3, the lowest point portion of the liquid level contact piece 7 does not change depending on the vertical position of the float 2. For this reason, the liquid level contact piece 7 can be connected to the arm 3 without considering the vertical position of the float 2. As described above, the above-described effects can be obtained while simplifying the connection of the liquid surface contact piece 7 to the arm 3.

  Instead of the retaining portion 31, a retaining ring member can be press-fitted into the arm 3.

  Further, the liquid surface contact piece 7 can be a washer between the retaining portion 31 and the float 2. The washer has a function of suppressing the float 2 from being scraped by the retaining portion 31, but the function of the washer can be substituted for the liquid level contact piece 7. That is, by providing the liquid level contact piece 7, such a washer becomes unnecessary.

(Second Embodiment)
In the second embodiment, as shown in FIG. 6, the disc-shaped and conductive liquid surface contact piece 7 </ b> A is electrically connected to the conductive arm 3 in a rotatable manner on the side surface side of the float 2. The disc-shaped liquid surface contact piece 7A has an insertion hole 71A through which the arm 3 is inserted at the substantial center of the circle and an adjustment hole 73A. The adjustment hole 73 </ b> A is an adjustment hole for preventing the liquid surface contact piece 7 </ b> A from becoming excessively heavy as compared with the liquid surface contact piece 7.

  Similarly to the liquid level contact piece 7, the liquid level contact piece 7A is also rotatably connected to the arm 3, and the lowest point of the liquid level contact piece 7A is the circumference of the liquid level contact piece 7A. . Therefore, unlike the liquid level contact piece 7, even if the liquid level contact piece 7A swings around the insertion hole 71A with respect to the arm 3 due to external vibration such as vehicle vibration, the liquid level contact piece 7A The vertical position of the lower point does not change. In the lowest position state of the float 2, the liquid level contact piece 7 </ b> A has the lowest point H <b> 1 positioned below the lowest point H <b> 3 that is the lowest side of the arm 3, and is the lowest side of the float 2. It is formed in a shape located below the lowest point H2.

  Even in the liquid level contact piece 7A, the same effect as in the first embodiment can be obtained, and even if the liquid level contact piece 7A swings around the insertion hole 71A with respect to the arm 3 due to external vibration, The charge of the arm 3 can be surely released to the outside through the liquid level contact piece 7A and the fuel A.

(Third embodiment)
In the third embodiment, as shown in FIG. 7, the conductive liquid surface contact piece 7 </ b> B is electrically connected to the conductive arm 3 in a rotatable manner on the side surface side of the float 2. The liquid level contact piece 7B has an insertion hole 71B through which the arm 3 is inserted, and from the insertion hole 71B, that is, from the connection position CP between the liquid level contact piece 7B and the arm 3 to the lowest point H1 of the liquid level contact piece 7B. It has a divergent portion 72B that widens toward the end. For this reason, even if external vibration such as vehicle vibration is applied and the liquid level contact piece 7B swings around the insertion hole 71B with respect to the arm, the tip of the divergent portion 72B is at the bottom of the liquid level contact piece 7B. Since it becomes the point H1, it can suppress that the lowest point H1 of the liquid level contact piece 7B goes up and down.

  Thereby, the effect similar to 2nd Embodiment can be acquired.

(Fourth embodiment)
In the fourth embodiment, as shown in FIG. 8, the conductive liquid surface contact piece 7 </ b> C is electrically connected to the conductive arm 3 in a rotatable manner on the side surface side of the float 2. The liquid level contact piece 7C is inserted from the insertion hole 71C through which the arm 3 is inserted and the insertion hole 71C, that is, from the connection position CP between the liquid level contact piece 7C and the arm 3 toward the lowest point H1 of the liquid level contact piece 7C. It has three legs 72C that expand. For this reason, even if external vibration such as vehicle vibration is applied and the liquid level contact piece 7C swings about the insertion hole 71C with respect to the arm, the tip side of the leg portion 72C is at the bottom of the liquid level contact piece 7C. Since it becomes the point H1, it can suppress that the lowest point H1 of the liquid level contact piece 7C goes up and down.

  Thereby, the effect similar to 2nd Embodiment can be acquired.

(Fifth embodiment)
In the above-described embodiment, the liquid level contact pieces 7 to 7 </ b> C are electrically connected to the arm 3 so as to be rotatable with respect to the conductive arm 3 on the side surface side of the float 2. On the other hand, in the fifth embodiment, as shown in FIGS. 9 and 10, the liquid level contact piece 7 </ b> D can be fixed to the conductive arm 3. Specifically, in FIG. 10, the arm 3 is inserted into the insertion hole 21 of the float 2, the tip of the arm 3 is bent, and this bent portion is defined as a liquid surface contact piece 7 </ b> D. In the lowest position state of the float 2, the liquid level contact piece 7 </ b> D has the lowest point H <b> 1 positioned below the lowest point H <b> 3 that is the lowest side of the arm 3, and is further on the lowest side of the float 2. It is formed in a shape located below the lowest point H2.

  As a result, when the liquid level position A1 is below the arm 3, the charge of the arm 3 can be released to the outside, and when the liquid level position A1 is below the float 2, the charge of the arm 3 is released to the outside. It becomes possible.

  Moreover, since the liquid level contact piece 7D fulfills the retaining function of the float 2, the retaining part 31 is not necessary in the above-described embodiment.

  Instead of the liquid surface contact piece 7D, a conductive liquid surface contact piece made of a metal rod or the like can be fixed to the portion 32 of the arm 3. Even in this case, when the liquid surface position A1 is below the arm 3, the charge of the arm 3 can be released to the outside. When the liquid surface position A1 is below the float 2, the arm 3 It is possible to release the electric charge to the outside.

(Sixth embodiment)
In the above-described embodiment, in the magnetoelectric conversion element type fuel level gauge 1, the conductive liquid surface contact pieces 7 to 7 </ b> D are electrically connected to the conductive arm 3. On the other hand, in the sixth embodiment, as shown in FIG. 11, in the electric resistance type fuel level gauge 10 that detects the fluctuation of the liquid level as a change in electric resistance, the conductive liquid level contact piece 7 is Electrical connection was made to the conductive arm 12.

  In FIG. 11, the fuel level gauge 10 connects a main body portion 14, a float 11 floating on the liquid surface of the fuel A, a rotating portion 13 that can rotate with respect to the main body portion 14, and the float 11 and the rotating portion 13. And an arm 12 that converts the vertical motion of the float 11 into the rotational motion of the rotating unit 13. A ceramic substrate 141 on which an electric resistor 142 is formed is fixed to the main body portion 14, and a sliding contact that slides on the electric resistor 142 while being electrically connected to the electric resistor 142. 131 is fixed.

  The electrical resistor 142 and the sliding contact 131 are configured such that the electrical resistance changes depending on the sliding position of the sliding contact 131 with respect to the electrical resistor 142. Specifically, the electrical resistor 142 includes electrical resistors 142A and 142B that are insulated and separated from each other, and the electrical resistors 142A and 142B are configured to be electrically connected by the sliding contact 131. . The electric resistor 142A is connected to the terminal 143A, the electric resistor 142B is electrically connected to the terminal 143B, and the electric resistance between the terminals 143A and 143B is the sliding position of the sliding contact 131 with respect to the electric resistor 142. It depends on. That is, the electrical resistance between the terminals 143A and 142B is the electrical resistance formed in the order from the terminal 143A to the electrical resistor 142A, the sliding contact 131, the electrical resistor 142B, and the terminal 143B, or in the opposite order. It becomes electric resistance by the route. For this reason, the electrical resistance between the terminals 143A and 143B varies depending on the sliding position of the sliding contact 131 with respect to the electrical resistor 142. The fuel level gauge 10 can detect the liquid level position of the fuel A by measuring the electric resistance.

  Also in FIG. 11, the liquid level position A1 of the fuel A is almost empty in the fuel tank, and the liquid level position A2 of the fuel A is full. FIG. 11 shows the fuel level gauge 10 at the liquid level position A1, and the liquid level position A2 and the float 11 and the arm 12 at the liquid level position A2 are indicated by two-dot chain lines. When the liquid level position A1 of the fuel A changes between the almost empty liquid level position A1 and the full liquid level position A2, the float 11 moves up and down in conjunction therewith, and the rotating part 13 is moved to the main body part 14. Is configured to rotate within a predetermined rotation range Θ.

  In other words, it can be said that FIG. 11 shows the fuel level gauge 10 in the lowest position in which the float 11 is located on the lowermost side in the vertical movement of the float 11. Further, the liquid level position A1 is located below the lowest point H2 that is the lowest side of the float 11 in the fuel level gauge 10 in the lowest position state.

  In FIG. 11, the liquid level contact pieces 7 </ b> A to 7 </ b> D can be used instead of the liquid level contact piece 7.

  Also in the sixth embodiment, the same effect as described above can be obtained.

1 is a front view of a fuel level gauge according to a first embodiment of the present invention. It is the II-II sectional view taken on the line in FIG. It is a schematic diagram explaining the magnetic flux distribution of the magnet shown in FIG. FIG. 4A is a front view of the liquid surface contact piece in FIG. 1, and FIG. 4B is a view taken along the arrow IVB in FIG. FIG. 5A is a view taken along arrow VA in FIG. 2, and FIG. 5B is a view taken along arrow VB in FIG. FIG. 6A is a front view for explaining the connection of the liquid level contact piece to the arm according to the second embodiment of the present invention, and FIG. 5B is a view taken along the arrow VIB in FIG. FIG. Fig.7 (a) is a front view for demonstrating the connection with respect to the arm of the liquid level contact piece by 3rd Embodiment of this invention, FIG.7 (b) is a VIIB arrow view in Fig.7 (a). FIG. FIG. 8 (a) is a front view for explaining the connection of the liquid level contact piece to the arm according to the fourth embodiment of the present invention, and FIG. 8 (b) is a view along arrow VIIIB in FIG. 8 (a). FIG. It is a front view of the fuel level gauge by 5th Embodiment of this invention. It is the XX sectional view taken on the line in FIG. It is a front view of the fuel level gauge by 6th Embodiment of this invention.

Explanation of symbols

1, 1A Fuel level gauge (liquid level detection device), 2 float, 21 insertion hole 3 arm, 31 retaining part, 31 part, 4 rotating part, 41 hole part 42 holding part, 43 convex part, 44 magnet (rotation angle) Detector), 5 body portion, 51 shaft portion, 511 convex portion, 52 Hall IC (magnetoelectric conversion element, rotation angle detector)
6 Terminal, 7, 7A, 7B, 7C, 7D Liquid surface contact piece (conductive member)
71, 71A, 71B, 71C Insertion hole, 72 Extension part, 72B End spreading part 72C Leg part, 73A Adjustment hole, 10 Fuel level gauge (liquid level detection device)
11 Float, 12 Arm, 13 Rotating part, 131 Sliding contact (Rotation angle detector)
14 body part, 141 ceramic substrate,
142, 142A, 142B Electrical resistor (rotation angle detector)
143, 143A, 143B terminal, A fuel (liquid), A1, A2 liquid level position H1 lowest point of liquid level contact piece, lowest point of H2 float, lowest point of H3 arm,
CP connection position, Θ Arm rotation angle range

Claims (5)

A main body part, a float floating on the liquid surface, a rotating part rotatable with respect to the main body part, and the float and the rotating part are connected to convert the vertical movement of the float into a rotational movement of the rotating part. In the liquid level detection device that detects the liquid level position by detecting the rotation angle of the arm, and a rotation angle detector that detects the rotation angle of the arm.
A conductive member electrically connected to the arm;
The conductive member is connected to the arm so as to be rotatable with respect to the arm on a side surface side of the float, and in the lowest position in which the float is located at the lowest side in the vertical movement, the conductive member A liquid level detecting device, wherein a lowest point which is the lowest side is positioned below a lowest point which is the lowest side of the arm.   2. The liquid level detection according to claim 1, wherein in the lowest position state, the lowest point of the conductive member is positioned below a lowest point which is the lowest side of the float. apparatus. Said conductive member, the liquid surface according to claim 1 or 2, characterized in Rukoto which have a shape which widens towards the connection position of the said conductive member arms to the lowest point of the conductive member Detection device. The rotation angle detector includes a magnet built in the rotating unit, and a magnetoelectric conversion element built in the main body so as to intersect with the magnetic flux of the magnet,
The rotational angle of the arm, according to any one of claims 1 to 3, wherein Rukoto detected by measuring the magnetic flux density of the magnet intersects the magnetoelectric converting element by the electromagnetic element Liquid level detection device. The rotation angle detector includes an electric resistor fixed to the main body portion, and a sliding contact fixed to the rotating portion and sliding on the electric resistor while being electrically connected to the electric resistor. And the electrical resistor and the sliding contact are configured such that the electrical resistance changes depending on the sliding position of the sliding contact with respect to the electrical resistor ,
The rotational angle of the arm, a liquid level detecting apparatus according to any one of claims 1 to 3, characterized in that is detected by measuring the electrical resistance.

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