JP2016057099A - Liquid level detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid level detector capable of simplifying an operation of assembling a main body part incorporating a detection element.SOLUTION: A liquid level detector F includes: a holder 2 rotating according to displacement of a float 7 in association with a variation in liquid level; a magnet 2a which is fixed to the holder 2 and which rotates together with the holder 2; a resin body 3 incorporating a magnetic detection element for detecting a variation in magnetic force in association with rotational motion of the magnet 2a; a first resin body 11 for holding the resin body 3; and a second resin body 12 for covering the resin body 3 and the first resin body 11. Guide parts 11a for guiding the resin body 3 and a fixation part 11c for fixing the resin body 3 are provided to the first resin body 11.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a liquid level detection device that detects a liquid level using magnetism.

  A conventional liquid level detection device includes a holder that rotates according to a displacement of a float accompanying a change in liquid level, a magnet that is fixed to the holder and that rotates with the holder, and a magnetic force change that accompanies the rotation of the magnet. And a main body part in which the magnetic detection element is incorporated, and a cover that rotatably supports the holder together with the main body part (see, for example, Patent Document 1).

JP2013-242174A

  However, in the conventional liquid level detection device, the main body portion includes a first resin body and a second resin body, and the magnetic detection element is disposed on the first resin body after the molding of the first resin body, After connecting the lead of the magnetic detection element to a terminal provided on the first resin body by laser welding or the like, insert molding is performed so as to cover the first resin body with the second resin body to form the main body portion However, when the first resin body is insert-molded so as to be covered with the second resin body, it is necessary to hold the magnetic detection element with a jig, so that the assembly workability is poor. There was a problem that the manufacturing process was complicated.

  Accordingly, the present invention focuses on the above-described problems, and an object thereof is to provide a liquid level detection device capable of simplifying the assembling workability of the main body portion incorporating the detection element.

  In order to solve the above-described problems, the present invention provides a holder that rotates according to a displacement of a float accompanying a change in liquid level, a magnet that is fixed to the holder and rotates together with the holder, and a rotating operation of the magnet And a second resin body that covers the resin body and the first resin body. In the liquid level detection device, a guide portion for guiding the resin body and a fixing portion for fixing the resin body are provided in the first resin body.

  With the above configuration, the present invention can achieve the intended purpose, and can provide a liquid level detection device capable of simplifying the assembly workability of the main body portion incorporating the detection element.

1 is a top view of a first embodiment of the present invention. Sectional drawing of the II-II line in FIG. 1 of the embodiment. The top view of the state before assembling the resin body of the embodiment to the 1st resin body. The top view of the state which assembled the resin body of the embodiment to the 1st resin body. The perspective view of the 1st resin body of the embodiment. The perspective view of the state which assembled the resin body of the embodiment to the 1st resin body. Sectional drawing of the principal part of the resin body and 1st resin body of 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  The liquid level detection device F of the present invention is installed in a fuel tank (not shown) that stores liquid fuel such as gasoline.

  The liquid level detection device F mainly includes a main body 1, a holder 2, a resin body 3 incorporating a magnetic detection element, and a cover 4.

  The main body 1 is composed of a first resin body 11 and a second resin body 12.

  The first resin body 11 is made of a resin material such as polyacetal (hereinafter referred to as POM), and incorporates a plurality of terminals 1a by molding. A resin body 3 and an electronic component (a noise absorbing capacitor or resistor) 5 are mounted on a portion of the terminal 1a exposed from the first resin body 11. In the present embodiment, the magnetic detection element incorporated in the resin body 3 and the electronic component 5 are connected by a lead 6, and the lead 6 is electrically connected to the terminal 1a.

  The first resin body 11 includes a guide portion 11a, a second guide portion 11b, and a fixing portion 11c.

  Moreover, the 1st resin body 11 is provided with the 1st area | region 11d to which the resin body 3 is fixed, and the 2nd area | region 11e which pinches | interposes this 1st area | region 11d from both sides. The first region 11d is formed to be thinner than the second region 11e, and the first region 11d is formed by the first region 11d and the wall portion 11f formed in the second region 11e. A cross-sectional shape surrounded by two surfaces forms a U-shaped recess.

  The guide part 11 a guides the guided part 3 a provided in the resin body 3. The guide portion 11a is provided so as to protrude from the wall portion 11f to the first region 11d side. Two guide portions 11a are provided. The guide part 11a includes a notch part 11g. When the guided portion 3a of the resin body 3 is guided and inserted into the notched portion 11g, the guided portion 3a is moved in the left, right, up and down direction by the notched portion 11g in the front, rear, left, and right directions indicated by the arrows in FIG. And the rearward movement is restricted. The guided portion 3a can move to the front side in FIG. 5, but the resin body 3 is held by the fixing portion 11c, and the movement to the front side in FIG. 5 is restricted. Therefore, the resin body 3 is held by the first resin body 11 by the guide portion 11a and the fixing portion 11c.

  The second guide portion 11 b guides the second guided portion 5 a provided in the electronic component 5. The second guide portion 11b is provided so as to protrude from the wall portion 11f to the first region 11d side. Two second guide portions 11b are provided. The 2nd guide part 11b is flat form, and is provided with the gap | interval part 11h between the plane parts of the 1st area | region 11d. When the second guided portion 5a of the electronic component 5 is guided to the gap portion 11h, the second guided portion 5a is moved by the second guide portion 11b in the front, rear, left, and right directions indicated by the arrows in FIG. Movement in the left / right and up / down directions is restricted. The second guided portion 5a can be moved in the front-rear direction in FIG. 5, but the resin body 3 connected by the electronic component 5 and the lead 6 is formed by the guide portion 11a and the fixing portion 11c in FIG. Since the movement in the front-rear direction is restricted, the second guided portion 5a is also restricted from moving in the front-rear direction in FIG.

  The fixing part 11 c fixes the resin body 3. In FIG. 5, the fixing part 11c is for the resin body 3 to restrict the movement in the forward direction, and for fixing the resin body 3 together with the guide part 11a. In this embodiment, the fixing | fixed part 11c is provided with the elastic piece 11k and the collar part 11m provided in this elastic piece 11k. The elastic piece 11k is elastically deformable so as to be deformed when the resin body 3 is assembled to the first resin body 11. When the resin body 3 is inserted into the guide portion 11a, the flange portion 11m abuts on the side surface of the resin body 3 and restricts the movement to the front side in FIG.

  The first resin body 11 in which the resin body 3 and the electronic component 5 are mounted on the terminal 1a is insert-molded by the second resin body 12 made of the same resin material as the first resin body 11, and the main body 1 is formed. . The first resin body 11 is covered with the second resin body 12 together with the resin body 3 and the electronic component 5. The first resin body 11 is hermetically sealed by the second resin body 12 together with the terminal 1a, the resin body 3, and the electronic component 5.

  The main body portion 1 includes a first rotation support portion 1b on which the holder 2 is rotatably supported. The first rotation support portion 1 b is formed integrally with the second resin body 12. The 1st rotation support part 1b is carrying out the column shape, and protrudes in the holder 2 side. The columnar first rotation support portion 1 b includes a sliding surface having a circular cross-sectional shape perpendicular to the rotation axis direction of the holder 2. In the main body 1 on the rotation axis of the first rotation support portion 1 b, the magnetic detection surface of the magnetic detection element is disposed so as to be perpendicular to the rotation axis direction of the holder 2.

  In addition, a positioning boss 1c is provided on the rear surface (opposite to the side where the holder 2 is provided) of the main body 1 to determine a position to be attached to, for example, a fuel pump or a mounting stay. And a hook 1d attached to a mounting stay or the like. Both the positioning boss 1c and the hook 1d are formed integrally with the second resin body 12.

  The main body 1 inserts a plurality of terminals 1a into the first resin body 11 by primary molding, the resin body 3 and the electronic component 5 are resistance-welded or soldered to the insert-molded terminals 1a, and further the first resin The body 11 is secondarily molded with the second resin body 12.

  The holder 2 is made of a resin material such as POM, and the magnet 2 a is fixed by insert molding and rotates together with the holder 2. Part of the magnet 2 a is exposed from the holder 2.

  The magnet 2 a is made of, for example, a neodymium-ferrite material or the like, and the shape thereof is a columnar shape around the rotation axis of the holder 2. Magnetization of the magnet 2a is dipole magnetization in this embodiment.

  The holder 2 is rotated according to the displacement of the float 7 accompanying the fluctuation of the liquid level, and a float arm 8 that transmits the displacement of the float 7 is fixed to the holder 2.

  The holder 2 is provided with a holding portion 2b4 that holds the magnet 2a.

  The holding portion 2b4 has a cylindrical shape, and its lower side is narrowed to be smaller than the outer shape of the magnet 2a, and includes a first hole 2b5 through which the magnet 2a is exposed.

  Further, the holder 2 is provided with a first rotating portion 2b2.

  The first rotating part 2b2 is provided below the holding part 2b4. The first rotating part 2b2 has a cylindrical shape, and the first hole 2b5 is provided in the first rotating part 2b2. The first rotating portion 2b2 is a slide in which a part of the inner peripheral surface of the cylindrical first hole 2b5 slides on the cylindrical outer peripheral sliding surface of the first rotating support portion 1b of the main body portion 1. It becomes a receiving surface and supports the holder 2 so that rotation is possible.

  Further, the holder 2 is provided with a second rotating portion 2b3.

  The second rotating part 2b3 has a cylindrical shape. The 2nd rotation part 2b3 is located above the 1st rotation part 2b2 on both sides of the magnet 2a in the rotation-axis direction of the magnet 2a. The central axes of the first rotation part 2b2 and the second rotation part 2b3 are on the same axis, and the rotation axis of the magnet 2a is also located on the same axis. In the second rotating portion 2b3, the outer periphery having a circular cross-sectional shape perpendicular to the rotating shaft direction of the magnet 2a is a sliding surface.

  The holder 2 is arranged so that the magnet 2a of the holder 2 faces the magnetic detection surface of the magnetic detection element when the first rotation portion 2b2 is fitted to the first rotation support portion 1b of the main body portion 1. The magnetic pole change of the magnet 2a accompanying the rotation operation of the holder 2 can be detected by the magnetic detection element. Moreover, the slidability of the holder 2 is improved by comprising the main-body part 1 and the holder 2 with the same resin material.

  The resin body 3 incorporates a magnetic detection element such as a Hall IC, for example, and the magnetic detection element detects a change in magnetic force associated with the rotation operation of the magnet 2a. The resin body 3 is electrically fixed to the terminal 1a together with the electronic component 5 by laser welding or resistance welding. The resin body 3 is built in the main body 1. Further, the magnetic detection element built in the resin body 3 is supplied with power and transmitted with a detection signal by a lead wire 9 electrically connected to the terminal 1a.

  The resin body 3 includes a guided portion 3a guided by the guide portion 11a. The guided portion 3 a is a plate-like body protruding from the side surface of the resin body 3, and the vertical thickness shown in FIG. 5 is smaller than the thickness of the resin body 3. As described above, the guided portion 3 a is guided by the guide portion 11 a provided in the first resin body 11, and the position of the resin body 3 with respect to the first resin body 11 is determined.

  The cover 4 is made of a resin material such as POM. The cover 4 is fixed to the main body 1 and prevents the holder 2 from falling off. The cover 4 includes a second rotation support portion 4a, a base portion 4b, a top plate portion 4c, and first and second wall portions 4d and 4e.

  The cover 4 has a shape in which the handle is vertically inverted by the base portion 4b, the top plate portion 4c, and the first and second wall portions 4d and 4e.

  The 2nd rotation support part 4a is provided in the top-plate part 4c. The second rotation support portion 4a has a cylindrical shape, and an inner peripheral surface thereof is a sliding receiving surface that slides with a sliding surface on the outer periphery of the second rotation portion 2b3. The 2nd rotation support part 4a supports the 2nd rotation part 2b3 so that rotation is possible.

  As shown in FIG. 2, the cover 4 is not in contact with the main body 1, but the base 4 b is fixed to a location (not shown) of the main body 1. The base 4b and the main body 1 are fixed by appropriate means such as laser welding.

  The top plate portion 4c has a flat disk shape, and includes a second rotation support portion 4a at the center of the top plate portion 4c.

  The first and second wall portions 4d and 4e are divided and have an arc shape when the liquid level detection device F is viewed from above. The float arm 8 is exposed from the portion where the first and second wall portions 4d and 4e are divided, and the first and second wall portions 4d and 4e function as a stopper that regulates the rotation range of the float arm 8. Plays. Although not shown, the lower end of the first wall 4d is fixed to the main body 1 by appropriate means such as laser welding.

  The electronic component 5 incorporates, for example, a noise absorbing capacitor or a resistor with resin. Similarly to the resin body 3, the electronic component 5 is also built in the main body 1. In addition, the components built in the electronic component 5 are supplied with power and transmitted with detection signals by lead wires 9 electrically connected to the terminals 1a.

  Further, the electronic component 5 includes a second guided portion 5a guided by the second guide portion 11b. The second guided portion 5 a is a plate-like body protruding from the side surface of the electronic component 5 made of resin, and the thickness in the vertical direction shown in FIG. 5 is smaller than the thickness of the electronic component 5. As described above, the second guided portion 5a is guided by the second guide portion 11b provided in the first resin body 11, and the position of the electronic component 5 with respect to the first resin body 11 is determined.

  The assembly of the resin body 3 and the electronic component 5 to the first resin body 11 will be described.

  As shown in FIG. 3, the second guided portion 5 a of the electronic component 5 is disposed between the guide portion 11 a and the second guide portion 11 b of the first resin body 11. At this time, the resin body 3 is in contact with the flange portion 11m of the fixed portion 11c and deforms the elastic piece 11k.

  Next, the guided portion 3a of the resin body 3 is inserted into the notch portion 11g of the guide portion 11a, and the second guided portion 5a of the electronic component 5 is inserted into the gap portion 11h of the second guide portion 11b. When the guided portion 3a of the resin body 3 comes into contact with the notch portion 11g of the guide portion 11a, the flange portion 11m that has been in contact with the resin body 3 is removed, and the flange portion 11m is originally formed by the elasticity of the elastic piece 11k. Returning to the position, the flange 11m is in a state where the resin body 3 is hooked, and the resin body 3 is held.

  Then, after the resin body 3 is fixed to the first resin body 11 by the fixing portion 11c, the fat body 3 and the lead 6 of the electronic component 5 are resistance welded or laser welded to the terminal 1a of the first resin body 11. Thus, the assembly of the resin body 3 and the electronic component 5 to the first resin body 11 is completed.

  As described above, the holder 2 that rotates according to the displacement of the float 7 accompanying the fluctuation of the liquid level, the magnet 2a that is fixed to the holder 2 and rotates together with the holder 2, and the magnetic force change that accompanies the rotating operation of the magnet 2a. A liquid comprising: a resin body 3 containing a magnetic detection element for detecting the resin body; a first resin body 11 holding the resin body 3; and a second resin body 12 covering the resin body 3 and the first resin body 11. In the surface detection device F, by providing a guide portion 11a for guiding the resin body 3 to the first resin body 11 and a fixing portion 11c for fixing the resin body 3, the resin body 3 incorporating the magnetic detection element is provided. The assembly to the first resin body 11 is simplified, and as a result, the assembly workability of the main body 1 incorporating the magnetic detection element can be simplified.

  Further, by providing the guided portion 3 a guided to the guide portion 11 a in the resin body 3, it is possible to prevent the resin body 3 from being displaced due to the molding pressure when the second resin body 12 is molded.

  Further, since the fixing portion 11c is the elastic piece 11k and the flange portion 11m provided on the elastic piece 11k, it is possible to prevent the resin body 3 from being displaced due to the molding pressure when the second resin body 12 is molded.

  The first resin body 11 includes a terminal 1a that supplies power to the magnetic detection element and outputs a signal. After the resin body 3 is fixed to the first resin body 11 by the fixing portion 11c, the terminal 1a and the magnetic field are supplied. Since the lead 6 of the detection element is resistance welded or laser welded, a jig or the like is not required, and assembly workability can be reduced.

  The above description exemplifies the present invention, and it goes without saying that various changes and modifications can be made without departing from the scope of the invention.

  In 1st Embodiment, although the fixing | fixed part 11c was provided with the elastic piece 11k and the collar part 11m provided in this elastic piece 11k, if it has a function which fixes the resin body 3, As shown in FIG. 7, the fixing portion 11n may be a protrusion. The protrusion 11n may have any shape as long as the resin body 3 is easy to ride on and is not easily removed.

  In the first embodiment, the plate-shaped guided portion 3a is provided in the resin body 3. However, if the position of the resin body 3 is determined, the resin body 3 is not provided with the guided portion 3a. The outer shape of the body 3 may be guided to determine the position.

  Moreover, in the said embodiment, although the resin body 3 and the electronic component 5 were connected with the lead | read | reed 6, the resin body 3 and the electronic component 5 may be made into the respectively independent components.

  INDUSTRIAL APPLICABILITY The present invention can be used for a liquid level detection device that covers a resin body containing a magnetic detection element by resin molding.

F liquid level detection device 1 body portion 1a terminal 1b first rotation support portion 1c boss portion 1d hook 2 holder 2a magnet 2b2 first rotation portion 2b3 second rotation portion 2b4 holding portion 2b5 first hole 3 resin body (magnetic) Detection element)
3a Guided portion 4 Cover 4a Second rotation support portion 4b Base portion 4c Top plate portion 4d First wall portion 4e Second wall portion 5 Electronic component 5a Second guided portion 6 Lead 7 Float 8 Float arm 9 Lead wire 11 First 1 resin body 11a guide portion 11b second guide portion 11c, fixing portion 11d first region 11e second region 11f wall portion 11g notch portion 11h gap portion 11k elastic piece 11m flange portion 12 second resin body

Claims (5)

Built-in holder that rotates according to the displacement of the float accompanying fluctuations in the liquid level, a magnet that is fixed to the holder and that rotates with the holder, and a magnetic detection element that detects a change in magnetic force associated with the rotating operation of the magnet In a liquid level detection apparatus comprising: a resin body that performs: a first resin body that holds the resin body; and a second resin body that covers the resin body and the first resin body.
A liquid level detection apparatus comprising: a guide portion for guiding the resin body to the first resin body; and a fixing portion for fixing the resin body. The liquid level detection device according to claim 1, wherein a guided portion guided by the guide portion is provided in the resin body. The liquid level detection device according to claim 1, wherein the fixing portion is an elastic piece and a flange provided on the elastic piece. The liquid level detection device according to claim 1, wherein the fixing portion is a protrusion. The first resin body includes a terminal that supplies power to the magnetic detection element and outputs a signal. After the resin body is fixed to the first resin body by the fixing portion, the terminal and the magnetic detection element The liquid level detection device according to claim 1, wherein the lead is resistance welded or laser welded.

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