JP2006317342A - Liquid level detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid level detection device capable of highly-accurate liquid level detection with a devised float support structure. <P>SOLUTION: A guide for guiding movement in the vertical direction of a float 8 whose position is moved up and down corresponding to the height of the liquid level 11 of a fuel 10 stored in a fuel tank 12 has a constitution provided with two guides, namely, a guide A and a guide B. Hereby, even if a force for rotating the float 8 around either of the guide A and the guide B is applied by liquid level rocking or the like, the other guide works so as to suppress the force, to thereby prevent the float 8 from rotating by using the guide A or the guide B as a rotation axis. Consequently, since the float 8 can be moved quickly and smoothly corresponding to fluctuation of the liquid level 11, a fuel level gage 1 capable of highly-accurate liquid level detection can be provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid level detection device for detecting a liquid level of a liquid contained in a tank, and in particular, a liquid having a float that floats on a liquid and that detects the liquid level based on the position of the float. The present invention relates to a surface detection device.

  This type of liquid level detection device is used, for example, as a liquid level detection device for monitoring the amount of fuel stored in a fuel tank of an automobile.

As a conventional liquid level detection device, for example, a guide that linearly moves and guides a float that floats on the liquid level, a float-side arm that is rotatably coupled to the float, a pointer shaft, a fixed to the pointer shaft, and A shaft arm fitted into the float side arm and relatively moving in the axial direction is provided. The pointer shaft is rotated by a linear movement of the float according to the fluctuation of the liquid level, and the liquid surface is fixed by the pointer fixed to the pointer shaft. There is one that indicates a position (for example, see Patent Document 1).
Japanese Utility Model Publication No. 62-143219

  In the conventional liquid level detection device, a rod-shaped guide passes through a hole provided so as to penetrate the float in the vertical direction, whereby the float is guided to move linearly.

  In the above-described configuration, the float can rotate about the guide as the rotation axis. For this reason, when the float rotates due to liquid level fluctuations, the float side arm and the shaft side arm are not in a straight line, but are positioned so as to intersect each other, and the float side arm and the shaft side arm are smooth in the axial direction. It becomes difficult to move to. Thereby, there is a problem that it is difficult to detect the liquid level with high accuracy.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid level detection device capable of detecting a liquid level with high accuracy by devising a support structure for a float.

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

  The liquid level detection device according to claim 1 of the present invention includes a float whose position moves up and down according to the height of the liquid level of the liquid stored in the tank, and holds the float and moves the float. The level of the liquid surface is detected based on the position of the float by generating a rotation arm that rotates and a rotation axis of the rotation arm and generating an output according to the rotation state of the rotation arm. In a liquid level detecting device comprising a main body having a liquid level detecting means for guiding and a guide for guiding the movement of the float in the vertical direction, the main body is rotated about a rotation axis and a rotation arm is provided. A holder for holding is provided, the rotating arm slides in a groove formed by a guide wall provided in the holder, and the distance of the float from the center of rotation is adjustable. Two are provided Guide float in contact with the float is characterized in that guided for linear movement.

  According to the above configuration, there are two guides for guiding the float so that the float moves linearly. Therefore, even if a force that rotates the float around one of the guides is applied, the other guide Work to deter. That is, the float is prevented from rotating around the guide as the rotation axis.

  Therefore, in the conventional liquid level detection device, the float rotates around the guide as a rotating shaft, making it difficult for the float side arm and the shaft side arm to move relative to each other in the axial direction, thereby preventing accurate liquid level detection. Thus, it is possible to provide a liquid level detection device capable of detecting a liquid level with high accuracy.

  According to a second aspect of the present invention, the guide is formed of a plurality of materials.

  With this configuration, for example, the portion of the guide that directly contacts the float and the other portion can be made from materials that are optimal in terms of function and productivity, so that the reliability and production of the guide can be improved. Can be improved.

  The liquid level detecting device according to claim 3 of the present invention is characterized in that the two guides are formed as an integral part.

  With such a configuration, the number of manufacturing steps for the liquid level detection device can be reduced.

  Hereinafter, a case where the liquid level detection device according to the embodiment of the present invention is applied to a fuel level gauge that is mounted in a fuel tank of an automobile and detects the level of fuel will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals.

(First embodiment)
FIG. 1 is a front view of a fuel level gauge 1 as a liquid level detection device according to a first embodiment of the present invention. FIG. 1 shows a state in which the liquid level 11 of the fuel 10 is at the lowest level. Further, in FIG. 1, the float 8 when the liquid level 11 of the fuel is in the highest position, that is, when the fuel tank 12 is full, and when the liquid level of the fuel 10 is at an intermediate position, that is, approximately halfway between full and empty. The arm 7 and the magnet holder 4 are indicated by broken lines.

  2 is a cross-sectional view taken along line II-II in FIG.

  1 and 2, the upper part of the figure is the upper part in the state where the fuel level gauge 1 is attached to the automobile.

  3 is a cross-sectional view taken along line III-III in FIG.

  FIG. 4 is a front view of the magnet holder 4 of the fuel level gauge 1 according to the first embodiment of the present invention.

  The fuel level gauge 1 detects the position of the liquid surface 11 of the fuel 10 that is a liquid in a fuel tank 12 that is a tank provided in an automobile. In an automobile, the remaining fuel amount in the fuel tank 12 is calculated by an electronic circuit (not shown) based on the detected liquid level 11 position, and the calculated remaining fuel amount is displayed on a display device (not shown) so that the driver can visually recognize it. Is done. The fuel level gauge 1 is disposed at the lowest position on the bottom surface of the fuel tank 12 so that the position of the liquid level 11 can be accurately detected even when the remaining amount of fuel is particularly small. The fuel level gauge 1 according to the first embodiment of the present invention is fixed to a fuel pump module (not shown) installed at the bottom of the fuel tank 12 and is connected to the fuel tank via the fuel pump module (not shown). 12 is installed. The fuel pump module (not shown) is a unit in which a fuel pump, a fuel filter, and the like for sending the fuel 10 in the fuel tank 12 to the engine are integrated.

  The fuel level gauge 1 is mainly composed of a float 8, an arm 7, a magnet 5 and a magnetoresistive element 6 as liquid level detecting means, a float guide 2 as a guide for guiding the vertical movement of the float 8, and the like. .

  The float 8 whose position moves up and down according to the height of the liquid surface 11 of the fuel 10 is formed from a resin material or the like in a substantially rectangular parallelepiped shape. The float 8 is set to have an apparent specific gravity smaller than that of the fuel by foam molding or cavity molding so as to surely float on the liquid surface 11 of the fuel 10.

  As shown in FIG. 3, guides extending in the up-down direction in FIG. 1 are provided on two opposing surfaces among the four side surfaces extending in the up-down direction in FIG. Grooves 81 and 82 are provided, respectively. As shown in FIG. 3, each guide groove 81, 82 is fitted with a rail portion 21a, 21b, 22f of a float guide 2 described later. Since gaps are formed between the guide grooves 81 and 82 and the rail portions 21a, 21b, and 22f, the float 8 is guided to the rail portion 21a, the rail portion 21b, and the rail portion 22f of the float guide 2 described later. Thus, the straight line can be smoothly moved in the vertical direction in FIG.

  Here, if the size of the gap between the guide grooves 81 and 82 and the rail portions 21a, 21b, and 22f is too small, the float 8 cannot move smoothly. On the other hand, if the size is too large, the float 8 in FIG. It tilts in the left-right direction and catches on the rail portions 21a, 21b, and 22f, so that the float 8 cannot move smoothly. In the fuel level gauge 1 according to the first embodiment of the present invention, the size of the gap between the guide grooves 81 and 82 and the rail portions 21a, 21b, and 22f is an appropriate value, that is, smooth linear movement of the float 8 is ensured. It is set to a size that allows it.

  As shown in FIG. 3, the float 8 is provided with a through hole 83 that penetrates in the horizontal direction. As shown in FIG. 3, an end of an arm 7 described later is inserted into the through hole 83. The diameter dimension of the through hole 83 is set slightly larger than the diameter dimension of the arm 7. Thereby, when the float 8 moves in the vertical direction in accordance with the position fluctuation of the liquid level 11 in the fuel tank 12, the arm 7 rotates with respect to the float 8.

  The arm 7 that is a rotating arm is formed, for example, in a substantially L shape from a metal rod-shaped member having a circular cross section. One end of the arm 7 is rotatably engaged with the float 8 as shown in FIG. On the other hand, the other end of the arm 7 is held by a magnet holder 4 as a holder that rotates around a shaft portion 31 that is a rotation shaft included in a sensor housing 3 that is a main body described later. That is, as shown in FIG. 4, it is slidably held in a groove formed by a guide projection 43 which is a guide wall provided in the magnet holder 4.

  Therefore, when the float 8 moves up and down in accordance with the vertical movement of the liquid level, the arm 7 rotates with respect to the through hole 83 of the float 8. At the same time, the sensor housing 3 rotates about the shaft portion 31 as a rotation center and linearly moves in a groove formed by the guide projection 43 of the magnet holder 4.

  Thereby, the vertical movement of the float 8 according to the vertical movement of the liquid level is transmitted to the magnet holder 4 via the arm 7, and the magnet holder 4 rotates around the shaft portion 31.

  The liquid level detection means for detecting the height of the liquid level 11 based on the position of the float 7, that is, the vertical position in FIG. 1 of the float 8, includes a magnet 5 that rotates in conjunction with the vertical movement of the float 8, and this magnet 5 is composed of a magnetoresistive element 6 which is a magnetoelectric conversion element arranged so as to intersect with a magnetic flux generated.

  That is, as shown in FIG. 2, the magnet 5, which is one of the liquid level detection means, rotates about the shaft portion 31 of the sensor housing 3, which is the rotation shaft of the arm 7, and holds the arm 7. It is held and fixed in the magnet holder 4. On the other hand, the magnetoresistive element 6 which is the other of the liquid level detecting means is disposed in the shaft portion 31 of the sensor housing 3 as a main body having the magnet 5 and the magnetoresistive element 6 as the liquid level detecting means as shown in FIG. Holding fixed.

  The magnet holder 4, which is a holder that holds the arm 7 while rotating around the shaft portion 31 of the sensor housing 3 that is the rotation shaft of the arm 7, is formed in an annular shape from, for example, a resin material. As shown in FIG. 2, the magnet holder 4 holds the magnet 5 in a built-in manner. The magnet holder 4 includes a hole 41 at the center thereof, and the hole 41 is rotatably fitted to the shaft 31 of the sensor housing 3 as shown in FIG. As shown in FIG. 2, a projection 42 is provided on the inner periphery of the hole 41 of the magnet holder 4, and this projection 42 is fitted into a groove 32 provided in the shaft 31 of the sensor housing 3. Thus, the movement of the magnet holder 4 in the axial direction of the shaft portion 31 (the left-right direction in FIG. 2) is restricted. When the magnet holder 4 rotates with respect to the sensor housing 3, the magnet 5 also rotates integrally with the magnet holder 4.

  As the magnet 5, for example, a ferrite magnet or the like is used. An annular magnet 5 is arranged coaxially with the hole 41, or two fan-shaped magnets 5 are arranged symmetrically and coaxially with respect to the hole 41. In any case, the magnet 5 rotates so that the magnetic flux generated by the magnet 5 is orthogonal to the axial direction of the shaft portion 31 of the sensor housing 3 and rotates around the shaft portion 31 in conjunction with the rotation of the magnet holder 4. In addition, the magnetized state is set.

  As shown in FIG. 1, the arm 7 is held by the magnet holder 4 so that it can slide in the axial direction. That is, as shown in FIG. 4, the magnet holder 4 is provided with two pairs of guide protrusions 43 that are guide walls with the hole 41 interposed therebetween. The distance between the pair of guide protrusions 43, that is, the width of the groove formed by the pair of guide protrusions 43 is slightly smaller than the diameter of the arm 7 so that the arm 7 can slide smoothly and without tilting in the groove. Largely formed. As shown in FIG. 1, a cap 44 is attached to these guide protrusions 43 to prevent the arm 7 from being detached from the guide protrusions 43. The cap 44 is made of, for example, a resin material.

The sensor housing 3 as the main body having the magnet 5 and the magnetoresistive element 6 as the liquid level detecting means is made of, for example, a resin material. As shown in FIG. 2, the sensor housing 3 includes a shaft portion 31, and the hole portion 41 of the magnet holder 4 is fitted to the outer periphery of the shaft portion 31, so that the magnet holder 4 is rotatably held. Yes. As shown in FIG. 2, the shaft portion 31 is provided with a groove portion 32 that engages with the protrusion portion 42 formed in the hole portion 41 of the magnet holder 4, and is coaxial with the shaft portion 31. As shown in FIG. 2, a magnetoresistive element 6 that is the other of the liquid level detecting means is built in the shaft portion 31. As shown in FIG. 2, the magnetoresistive element 6 has an overlapping length with the magnet 5 as long as possible in the axial direction of the shaft portion 31, in other words, the amount of magnetic flux generated by the magnet 5 intersecting the magnetoresistive element 6 is increased. It is arranged to increase. As a result, the output voltage of the magnetoresistive element 6 can be increased to increase the detection accuracy of the liquid level 11 of the fuel level gauge 1, and the noise resistance can be increased.

  The sensor housing 3 includes a terminal 9 for electrically connecting the magnetoresistive element 6 to the outside. In the fuel level gauge 1 according to the first embodiment of the present invention, since the magnetoresistive element 6 includes two electrodes, two terminals 9 are also provided as shown in FIG. As shown in FIG. 1, an electric wire 91 is connected to the terminal 9. The magnetoresistive element 6 is a control circuit (not shown) that receives a detection signal from an external electric circuit, for example, the magnetoresistive element 6 through each electric wire 91, measures the position of the liquid surface 11 and calculates the remaining amount in the fuel tank 12. Etc.).

  In the sensor housing 3, for example, the terminal 9 is connected to the lead 61 of the magnetoresistive element 6 by fusing or caulking, and the wire 9 is connected to the terminal 9 by fusing or caulking after insert molding at the time of resin molding. Made.

  As shown in FIG. 1, the sensor housing 3 is provided with four fixing claws 33. As shown in FIG. 3, the fixing claw 33 is inserted and locked in a locking hole 22 d provided in the base 22 of the float guide 2 described later, and the sensor housing 3 is fixed to the float guide 2.

  The float guide 2 includes a guide A and a guide B that are two guides for guiding the vertical movement of the float 8, and a base made of a resin material that holds both the guides A and B while maintaining a predetermined positional relationship. 22.

  The upper half in FIG. 1 which is a part of the guide A and the guide B is integrally formed by bending a guide frame 21 made of a stainless steel rod having a circular cross section into a shape as shown in FIG. . The lower half in FIG. 1, which is the remaining part of the guide B, is formed integrally with the base 22. That is, the guide A is formed by the rail portion 21a of the guide frame 21, and the guide B is formed by the rail portion 21b of the guide frame 21 and the rail portion 22f of the base 22 arranged so as to be smoothly connected thereto. Moreover, the rail part 21a, the rail part 21b, and the rail part 22f are arrange | positioned in parallel.

  The tip of the rail portion 22f on the groove 82 side of the float 8 is formed in a semicircular shape having the same radius as the stainless steel rod constituting the guide frame 21, as shown in FIG. Moreover, as shown in FIG. 1, the connection part with the rail part 21b of the rail part 22f is formed in the taper shape which becomes thin gradually as it approaches the rail part 21b. Thereby, when the float 8 moves up and down, it can pass smoothly from the rail part 21b to the rail part 22f or vice versa.

  As shown in FIG. 1, the guide frame 21 is provided with a stopper portion 21 c that regulates the highest position of the float 8. The position S of the stopper portion 21c is formed so as to correspond to the highest position of the liquid level of the fuel tank 12 to which the fuel level gauge 1 is applied, that is, the float position H2 at the full liquid level position.

  As shown in FIG. 1, both ends of the guide frame 21 are press-fitted and fixed to holding holes 22 a and 22 b provided in the base 22.

  The height dimension H1 (see FIG. 1) of the base 22 of the float guide 2 enables the fuel level gauge 1 according to the first embodiment of the present invention to be applied to various types of fuel tanks 12 having different liquid level levels when full. Therefore, the fuel tank 12 to which the fuel level gauge 1 can be applied is set lower than the height from the fuel level gauge 1 installation position to the upper surface of the fuel tank 12 in the fuel tank 12 having the lowest full liquid level. Yes.

  The base 22 is provided with a through hole 22e and a locking hole 22d. As shown in FIG. 2, the sensor housing 3 is attached to the base 22 by engaging the engaging claw 33 of the sensor housing 3 with the engaging hole 22d while inserting the shaft portion 31 of the sensor housing 3 into the through hole 22e. Fixed. The base 22 is formed with a support surface 22c as an attachment surface when the fuel level gauge 1 is attached to a fuel pump module (not shown), and the support surface 22c has two attachment holes 22h as through holes. Is provided. The mounting hole 22h is for screwing the float guide 2, that is, the fuel level gauge 1 to a fuel pump module (not shown). Further, as shown in FIG. 1, the base 22 includes a stopper portion 22 g that regulates the lowest position of the float 8 described later.

  Next, the assembly method of the fuel level gauge 1 according to the first embodiment of the present invention will be described in order.

  In addition, the sensor housing 3 and the magnet holder 4 are already completed before the process demonstrated below. In other words, the magnetoresistive element 6 and the terminal 9 are incorporated into the sensor housing 3 at a predetermined position, and the magnet 5 is incorporated into the magnet holder 4 at a predetermined position.

  First, the float guide 2 is assembled. That is, both ends of the guide frame 21 are press-fitted and fixed to the holding holes 22 a and 22 b of the base 22 while the guide grooves 81 and 82 of the float 8 are fitted and inserted into the rail portion 21 a and the rail portion 21 b of the guide frame 21. Accordingly, the float 8 is held by the float guide 2 so as to be linearly movable along the guides A and B.

  Next, the sensor housing 3 is fixed to the float guide 2. That is, while the shaft portion 31 of the sensor housing 3 is inserted into the through hole 22e of the base 22, the four locking claws 33 of the sensor housing 3 are inserted and locked into the corresponding locking holes 22d of the base 22.

  Next, the magnet holder 4 is attached to the sensor housing 3. That is, the hole portion 41 of the magnet holder 4 is fitted into the shaft portion 31 of the sensor housing 3 protruding from the base 22, and is further pushed rightward in FIG. Engage with the groove 32. Thereby, the magnet holder 4 is restricted from moving in the axial direction of the shaft portion 31 (left and right direction in FIG. 2), and the magnet holder 4 is rotatably held by the sensor housing 3.

  Next, the arm 7 is attached. That is, one end of the arm 7 is inserted into the through hole 83 of the float 8, the other end of the arm 7 is fitted between the pair of guide projections 43 of the magnet holder 4, and the cap 44 is attached from above. Thereby, the arm 7 is slidably held by the magnet holder 4.

  This completes the assembly of the fuel level gauge 1 according to the first embodiment of the present invention.

  The completed fuel level gauge 1 is fixed to a fuel pump module (not shown) by screwing through a mounting hole 22h provided in the float guide 2. A fuel level gauge 1 is installed in the fuel tank 12 by installing a fuel pump module (not shown) at the bottom of the fuel tank 12.

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

  When the height of the liquid level 11 of the fuel 10 fluctuates, the float 8 floating on the liquid level 1 is also guided by the guides A and B of the float guide 2 and moves linearly, that is, moves up and down in FIG. When the float 8 moves in the vertical direction in FIG. 1, the arm 7 rotates about the shaft portion 31 of the sensor housing 3. At this time, the distance from the through hole 83 of the float 8 to the center of the shaft portion 31 changes as the float 8 moves up and down. However, since the arm 7 is slidably held by the magnet holder 4, the arm 7 moves linearly with respect to the magnet holder 4 by the amount of variation in the distance from the through hole 83 to the center of the shaft portion 31. Thereby, the fluctuation | variation of the above-mentioned distance is absorbed, and the magnet holder 3 can be smoothly rotated in conjunction with the vertical movement of the float 8.

  When the magnet 5 rotates in conjunction with the rotation of the arm 7, the magnetic flux density across the magnetoresistive element 6 changes and the output voltage of the magnetoresistive element 6 changes. Based on the output voltage of the magnetoresistive element 6, the position of the float 8, that is, the liquid level 11 position H in the fuel tank 12 is recognized, and the residual fuel amount in the fuel tank 12 is calculated based on the liquid level 11 position H. Is done.

  Next, the features of the fuel level gauge 1 according to the first embodiment of the present invention configured as described above, that is, two guides for guiding the vertical movement of the float 8 are provided, that is, the guide A and the guide B are provided. The operation and effect of this will be described.

  In the conventional liquid level detection device, a rod-shaped guide passes through a hole provided so as to penetrate the float in the vertical direction, whereby the float is guided to move linearly. That is, the float can rotate about the guide as a rotation axis. In such a configuration, when the float rotates due to liquid level fluctuation or the like, the float-side arm and the shaft-side arm are in a positional relationship such that they intersect with each other without being in a straight line. Becomes difficult to move smoothly in the axial direction. Thereby, there is a problem that it is difficult to detect the liquid level with high accuracy.

  On the other hand, in the fuel level gauge 1 according to the first embodiment of the present invention, there are two guides A and B that guide the float 8 so that the float 8 moves linearly. Even if a force is applied to rotate around the guide, the other guide acts to suppress it. That is, the float 8 is prevented from rotating about the guide A and the guide B as the rotation axis, and only the linear movement along the guide A and the guide B is possible.

  Therefore, since the float 8 can move quickly and smoothly in response to the fluctuation of the liquid level 11, the fuel level gauge 1 capable of detecting the liquid level with high accuracy can be provided.

(Second Embodiment)
FIG. 5 shows a front view of the fuel level gauge 1 according to the second embodiment of the present invention.

  FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG.

  The fuel level gauge 1 according to the second embodiment of the present invention has two pieces for guiding the shape of the float guide 2, that is, the linear movement of the float 8, with respect to the fuel level gauge 1 according to the first embodiment described above. The shape of the guide has been changed. Along with this, the shape of the float 8 is also changed.

  Hereinafter, the configuration of the fuel level gauge 1 according to the second embodiment of the present invention, particularly the configuration of the float guide 2 will be mainly described.

  In the float guide 2 of the fuel level gauge 1 according to the second embodiment of the present invention, as shown in FIG. 5, one of the two guides A is a guide rail 23 made of a stainless steel rod having a circular cross section. The guide B, which is the other of the two guides, is formed from a rail portion 22 f that is formed integrally with the base 22. That is, in the fuel level gauge 1 according to the second embodiment of the present invention, the rail portion 22f of the fuel level gauge 1 according to the first embodiment is extended so as to guide the float 8 over the entire movement range of the float 8. Further, the guide rail 23 and the rail portion 22f are arranged in parallel. The guide rail 23 is linearly formed as shown in FIG. 5, and both ends thereof are press-fitted into the holding holes 22 a and 22 b of the base 22.

  As shown in FIG. 6, the float 8 eliminates the groove portion 81 while leaving the groove portion 82 and adds a through hole 84 to the float 8 of the fuel level gauge 1 according to the first embodiment. A guide rail 23 is inserted through the guide rail 23. Thereby, the float 8 is guided by the guide rail 23 and the rail portion 22f parallel to each other, and moves linearly.

  Therefore, also in the fuel level gauge 1 according to the second embodiment of the present invention, the float 8 is prevented from rotating about the guide A and the guide B as the rotation axis, and can only move linearly along the guide A and the guide B. It becomes.

  Therefore, since the float 8 can move quickly and smoothly in response to the fluctuation of the liquid level 11, the fuel level gauge 1 capable of detecting the liquid level with high accuracy can be provided.

  In the fuel level gauge 1 according to the second embodiment of the present invention described above, as shown in FIG. 7, the groove portion 82 of the float 8 and the rail portion 22 f of the base 22 are abolished, and the guide B is fixed to the base 22. It is good also as a structure which forms with the wall part 22j and the wall part 22j guides the float 8. FIG.

  In the fuel level gauge 1 according to the first embodiment and the second embodiment of the present invention described above, the magnetoresistive element 6 and the magnet 5 which are magnetoelectric conversion elements are used as the liquid level detecting means. A different type of magnetoelectric conversion element from the magnetoresistive element 6 may be used as the conversion element. For example, a Hall element or a magnetic diode may be used.

  In the fuel level gauge 1 according to the first embodiment and the second embodiment of the present invention described above, the magnetoresistive element 6 and the magnet 5 are used as the liquid level detection means. It is not necessary to limit to such a combination, and it may be replaced with other types of liquid level detection means. For example, the liquid level detection means may be a combination of a resistance element and a sliding piece made of a conductive member slidably disposed on the resistance element. That is, if the sliding piece is arranged so as to be movable in accordance with the change in the liquid level, the position of the contact point with the sliding piece on the resistance element is changed when the sliding piece moves in accordance with the change in the liquid level. This changes the resistance value between the sliding piece and the end of the resistance element. The liquid level can be measured based on this resistance value.

  In the fuel level gauge 1 according to the first embodiment and the second embodiment of the present invention described above, the member to be attached is a fuel pump module (not shown), but it is necessary to limit the member to the fuel pump module. It may be attached directly in the fuel tank 12.

  Further, in the first and second embodiments of the present invention described above, the case where the liquid level detection device is applied to the fuel level gauge 1 for an automobile has been described as an example. The present invention is not limited to the fuel level gauge 1 and may be applied to a liquid level detection device incorporated in various consumer devices. Further, the liquid as the liquid level detection target is not limited to the fuel, and may be water, lubricating oil, various chemicals, or the like.

1 is a front view of a fuel level gauge 1 according to a first embodiment of the present invention. It is the II-II sectional view taken on the line in FIG. It is the III-III sectional view taken on the line in FIG. It is a front view of the magnet holder 3 of the fuel level gauge 1 by 1st Embodiment of this invention. It is a front view of the fuel level gauge 1 by 2nd Embodiment of this invention. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. It is sectional drawing in the modification of the fuel level gauge 1 by 2nd Embodiment of this invention.

Explanation of symbols

1 Fuel level gauge (Liquid level detector)
2 Float guide 21 Guide frame 21a Rail part (guide)
21b Rail (guide)
21c Stopper part 22 Base 22a Holding hole 22b Holding hole 22c Support surface 22d Locking hole 22e Through hole 22f Rail part (guide)
22g Stopper 22h Mounting hole 22j Wall (guide)
23 Guide rail (guide)
3 Sensor Holder 31 Shaft 32 Groove 33 Locking Claw 4 Magnet Holder 41 Hole 42 Projection 43 Guide Projection (Guide)
44 Cap 44a Groove (Guide part)
5 Magnet (liquid level detection means)
6 Magnetoresistive element (liquid level detection means)
61 Lead 7 Arm 71 Tip 8 Float 81 Guide Groove 82 Guide Groove 83 Through Hole 84 Through Hole 9 Terminal 91 Electric Wire 10 Fuel (Liquid)
11 Liquid level 12 Fuel tank (tank)
A Guide B Guide D Distance dimension H Liquid level position H1 Height dimension H2 Full float position L Projecting length S Stopper position

Claims (3)

A float whose position moves up and down according to the height of the liquid level of the liquid stored in the tank;
A rotating arm that holds the float and rotates as the float moves;
A liquid level detection that is provided with a rotation axis of the rotation arm and detects the height of the liquid level based on the position of the float by generating an output corresponding to the rotation state of the rotation arm. A body having means;
In a liquid level detection device comprising a guide for guiding the vertical movement of the float,
The main body is provided with a holder that rotates about the rotation axis and holds the rotation arm.
The rotating arm slides in a groove formed by a guide wall provided in the holder,
The float distance from the center of rotation is adjustable.
2. The liquid level detecting device according to claim 2, wherein two guides are provided and each guides the float so that the float moves linearly.   The liquid level detection device according to claim 1, wherein the guide is formed of a plurality of materials.   The liquid level detection device according to claim 1, wherein the two guides are formed as an integral part.

Images