JP6003817B2 - Method for manufacturing terminal of liquid level detection device - Google Patents

Description

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

  2. Description of the Related Art Conventionally, a structure installed at a position where the liquid is immersed, such as a liquid level detection device, is provided with a seal structure that prevents liquid such as fuel from entering inside. As a kind of such a structure, for example, the liquid level detection device disclosed in Patent Document 1 has an uneven portion at the center of a plate-shaped terminal made of brass, and the uneven portion is completely around the uneven portion. A sealing film made of a covering adhesive is formed. Then, the sealing film provided between the uneven portion of the terminal and the covering portion prevents the liquid from entering between the terminal and the covering portion.

JP-A-4-324323

  However, in the liquid level detection device disclosed in Patent Document 1, the adhesion between the uneven surface and the seal film is poor, and the sealability between the terminal and the covering portion may be insufficient.

  The present invention has been made in view of the above-described problems. The purpose of the present invention is to provide a sealing property between the terminal and the covering portion by bonding the sealing film with the plating layer with high adhesion by the anchor effect. An object of the present invention is to provide a method of manufacturing a terminal of a liquid level detection device to be enhanced.

The present invention relates to a method of manufacturing a terminal that is embedded in a covering portion and transmits an electrical signal related to detection of the height of the liquid level in a liquid level detection device that detects the height of the liquid level. to, by plating, a first step of forming a plating layer, after the first step, a second step of performing press working to bend the terminal to generate fraud and mitigating risk crack the plating layer on the press section of the terminal Then, after the second step, a liquid sealing material is applied to the press part, a third step in which the sealing material penetrates into the cracks by capillary action, and after the third step, the sealing material is cured to form a sealing film. And a fourth step.

  According to the present invention as described above, since the terminal is bent so that cracks are generated in the pressed portion of the terminal after plating is performed on the terminal, cracks are generated in the plated layer of the pressed portion. Furthermore, since a liquid sealing material is applied to the press part thereafter, the sealing material penetrates into cracks in the plating layer due to a capillary phenomenon, and the sealing film is bonded to the plating layer with high adhesion by an anchor effect. As mentioned above, the manufacturing method of the terminal of the liquid level detection apparatus which improves the sealing performance of a terminal and a coating | coated part can be provided.

  Further, according to a further feature of the present invention, the plate-like press part has two side surfaces and two plate surfaces adjacent to the two side surfaces, and in the second step, one plate surface in the press part. A bent portion bent to the side and another bent portion bent to the other plate surface side are formed.

  According to such a feature, in the second step, either one of the terminals is formed by a press part in which a bent part bent to one plate surface side and another bent part bent to the other plate surface side are formed. Cracks also occur on the plate surface and side surfaces. Therefore, the seal film is bonded to the plating layer with high adhesion by the anchor effect on any plate surface and side surface. As mentioned above, the manufacturing method of the terminal of the liquid level detection apparatus which improves the sealing performance of a terminal and a coating | coated part can be provided.

  Further, in a further feature of the present invention, in the first step, the plating is formed thicker at the corner than at the center of the terminal.

  According to such a feature, the plating formed thicker at the corner than at the center of the terminal tends to cause cracks at the corner, so the sealing film has high adhesion to the plating layer at the corner of the terminal. Can be glued.

It is a front view of the liquid level detection apparatus in one Embodiment. It is the II-II sectional view taken on the line of FIG. It is a flowchart which shows the manufacturing method of the liquid level detection apparatus in one Embodiment. It is a figure which shows the shape of the metal plate material in the 1st process of FIG. It is the VI-VI sectional view taken on the line of FIG. It is a perspective view which shows the press part of the terminal in the 2nd process of FIG. It is sectional drawing which shows the press part of the terminal in the 3rd process of FIG. It is sectional drawing which shows the press part of the terminal in the 4th process of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the liquid level detection device 1 of the present embodiment is installed in a fuel tank 2 that stores fuel as a liquid. The liquid level detection device 1 detects the height of the liquid level 4 of the fuel stored in the fuel tank 2 while being held by the fuel pump module 3 or the like. The liquid level detection device 1 includes a housing 10, a float 20, a magnet holder 30, a Hall IC 40, and the like.

  The housing 10 shown in FIG. 2 includes an inner case 12, a terminal 54, an outer case 14, and the like. The inner case 12 is made of a resin material such as polyphenylene sulfide (PPS) resin. The inner case 12 has a bottomed container shape by a bottom wall 120 formed in a rectangular plate shape and a side wall 122 erected along an outer edge portion of the bottom wall 120. In the inner case 12, an inner shaft portion 124, an element housing chamber 126, a support wall portion 128, and the like are formed. In the following description, the longitudinal direction of the bottom wall 120 is defined as the vertical direction VD, and the direction substantially orthogonal to the longitudinal direction along the bottom wall 120 is defined as the width direction WD. Furthermore, the thickness direction of the bottom wall is defined as a thickness direction TD.

  The inner shaft portion 124 is provided on the side opposite to the side wall 122 with the bottom wall 120 interposed therebetween. The element accommodation chamber 126 is a space for accommodating the Hall IC 40. The element housing chamber 126 is formed inside the inner shaft portion 124.

  The support wall portion 128 is a part of the side wall 122 and is located above the inner shaft portion 124 in the vertical direction VD. The support wall 128 extends along the width direction WD. Three through holes 130 for supporting each terminal 54 are formed in the support wall portion 128. Each through hole 130 is an opening through which each terminal 54 passes, and is formed at equal intervals in the width direction WD. The support wall portion 128 surrounds the outer peripheral side of each terminal 54 over the entire periphery.

  The three terminals 54 (see also FIG. 1) are formed in a strip shape extending in the vertical direction VD by a conductive material such as phosphor bronze. Each terminal 54 is used for transmission of an electric signal such as a voltage between an external device and the Hall IC 40. A cross section orthogonal to the longitudinal direction in each terminal 54, that is, a cross section of each terminal 54 has a rectangular shape. The thickness of each terminal 54 is about 0.6 mm, for example. Each terminal passes through the support wall 128 by passing through one of the three through holes 130. Each terminal 54 has a protrusion 56 and a connection 58.

  The protruding portion 56 is a portion of the terminal 54 that protrudes from the support wall portion 128 to the outside of the inner case 12. The protrusion 56 protrudes upward along the vertical direction VD. The connection part 58 is a part accommodated in the inner case 12 in the terminal 54. The connection unit 58 is connected to the Hall IC 40.

  A seal film 76 is formed around each terminal 54. The seal film 76 is embedded in the covering portion 142 of the outer case 14. The sealing film 76 is in close contact with each terminal 54 and the covering portion 142, thereby closing a gap generated between them. The sealing film 76 prevents the fuel that enters the covering portion 142 through the terminals 54 from entering the inner case 12 through the gap between the support wall portion 128 and the terminals 54.

  The outer case 14 is made of a resin material such as PPS resin. The outer case 14 is formed so as to cover the outer side of the inner case 12 and accommodates the inner case 12. The outer case 14 is formed with an outer shaft portion 140, a covering portion 142, and the like.

  The outer shaft portion 140 is formed in a cylindrical shape and covers the outer side of the inner shaft portion 124. The axial direction of the outer shaft portion 140 is directed in the thickness direction TD. The outer shaft portion 140 is built in the magnet holder 30 so as to rotatably support the magnet holder 30. The covering portion 142 extends along the width direction WD (see FIG. 1). The covering portion 142 protects these from the fuel by covering the base end portion of the protruding portion 56 from both sides in the thickness direction TD.

  The float 20 shown in FIG. 1 is formed of a material having a specific gravity smaller than that of a fuel such as foamed ebonite. The float 20 can float by the fuel level 4. The float 20 is supported by the magnet holder 30 via the float arm 22. The float arm 22 is made of a metal material such as stainless steel, and is inserted through a through hole 24 formed in the float 20.

  The magnet holder 30 shown in FIGS. 1 and 2 is formed in a disk shape from a resin material. The magnet holder 30 is formed with a fixed portion 32 and a bearing portion 34. In addition, the magnet holder 30 accommodates a pair of magnets 36. The magnet holder 30 is integrated with the magnet 36 and rotates relative to the housing 10 so as to follow the liquid level.

  The fixing portion 32 is formed on the top surface of the magnet holder 30 that faces away from the housing 10. The fixing portion 32 holds the float arm 22. The bearing portion 34 is provided at the radial center portion of the magnet holder 30. A cylindrical hole is formed in the bearing portion 34 along the axial direction of the magnet holder 30. The bearing portion 34 is fitted on the outer shaft portion 140. The pair of magnets 36 are disposed so as to face each other with the bearing portion 34 interposed therebetween, thereby forming a magnetic flux that passes through the Hall IC 40 accommodated in the element accommodating chamber 126.

  The Hall IC 40 shown in FIG. 2 is a detection element that detects the relative angle of the magnet holder 30 with respect to the housing 10. The Hall IC 40 is composed of an element main body 42, three lead wires 44, and the like. The element main body 42 is accommodated in the element accommodating chamber 126 so as to be sandwiched between the pair of magnets 36. Each lead wire 44 extends from the element main body portion 42 and is connected to each connection portion 58 of each terminal 54. The Hall IC 40 generates a signal proportional to the density of the magnetic flux passing through the Hall IC 40 by receiving a magnetic field action from the magnet 36 in a state where a voltage is applied. A signal generated in the Hall IC 40 is measured by an external device via each lead wire 44, each terminal 54, and the like.

  Next, the manufacturing method of the terminal 54 of the liquid level detection apparatus 1 in this embodiment is demonstrated according to the flowchart of FIG.

  In the first step S10, the terminal 54 is plated. For example, in the stage of the first step S10, the terminal 54 forms a metal plate 50 made of phosphor bronze or the like to which a plurality of terminals 54 are connected, as shown in FIG. Immerse in an electroless bath. As a result, the oxidation-reduction reaction occurs, so that the metal in the electroless bath is deposited on the entire surface of the metal plate 50, and the plating layer 74 is formed. Alternatively, the metal plate 50 is immersed in an electrolytic bath, and direct current electrolysis or pulse electrolysis using the metal plate 50 as a cathode is performed. As a result, the metal in the electrolytic bath is deposited on the entire surface of the metal plate 50 by an electrochemical reaction, and the plating layer 74 is formed. Thus, by forming the plating layer 74 on the entire surface of the metal plate member 50, the first step S <b> 10 is performed at the same time as plating the portions other than the press portion 64 in the terminal 54. Further, as shown in FIG. 5, the plating layer 74 is formed thicker at the corner portion 62 than the metal plate material 50, that is, the central portion 60 of the terminal 54.

  The metal forming the plating layer 74 in the first step S10 is preferably a hard metal such as nickel or chromium in consideration of crack generation in the second step S20 described later. Conversely, metals with large ductility such as solder, tin, copper, or gold are considered unsuitable. However, in the case of forming the plating layer 74 by laminating a plurality of metals, it may be possible to use a metal having a large ductility for a part of the plating layer 74. Selection of the metal which forms these plating layers 74 is performed by confirming by experiment etc. what the crack is easy to produce in the press part 64 in 2nd process S20.

  In the second step S <b> 20, press work is performed to bend the terminal 54 so as to cause a crack in the press portion 64 of the terminal 54. The press part 64 is plate-shaped, has two side surfaces 68a and 68b, and two plate surfaces 66a and 66b adjacent to the two side surfaces 68a and 68b, and has a rectangular cross section. . Then, by pressing the press portion 64 using a bending die or a bending punch and a die, the press portion 64 has a bent portion bent to one plate surface side and another bent to the other plate surface side. Are formed. More specifically, as shown in FIG. 6, the press portion 64 has a U-shaped shape when viewed from the side surface 68 a or 68 b, and a bending portion 70 that is bent toward the plate surface 66 b is formed. Two bent portions 72a and 72b that are bent toward the plate surface 66a are formed with the portion 70 interposed therebetween.

  And by this press work, a fine crack arises in the plating layer 74 formed in the surface of the press part 64. FIG. In the plate surface 66a, the surface of the bent portion 70 is curved in a convex shape, so that at least one fine crack is generated in the plating layer 74 on the bent portion 70 so as to cross the electric signal transmission direction. Further, in the plate surface 66b, the surfaces of the bent portions 72a and 72b are curved in a convex shape, so that at least one or more fine so as to cross the electric signal transmission direction in the plating layer 74 on each of the bent portions 72a and 72b. Cracks occur. Further, even in the U-shaped side surfaces 68a and 68b, distortion occurs due to different stresses applied to the plate surface 66a side and the plate surface 66b side in the bent portions 70, 72a, and 72b. At least one fine crack is generated in the plating layer 74 so as to cross the transmission direction of the electric signal. Therefore, cracks are generated in any of the plate surfaces 66a and 66b and the side surfaces 68a and 68b.

  Such cracks in the plating layer 74 become deeper at the portion where the plating layer 74 is thick. Therefore, in this embodiment, the crack is deeper in the corner 62 due to the plating layer formed thicker in the corner 62 than in the center 60.

  Note that, in the second step S20, parts other than the press part 64 are pressed in the terminal 54 together. For example, by inserting the metal plate material 50 formed by connecting a plurality of terminals 54 into an automatic machine, the terminals 54 are separated by punching the connection portion 52 of the metal plate material 50 together with the processing of the press portion 64 described above.

  In the third step S30, a liquid sealing material 92 is applied to the press portion 64. The sealing material 92 is made of hydrin rubber or the like made liquid with a solvent such as toluene. As shown in FIG. 7, the sealing material 92 supplied from the dispenser 90 of the manufacturing apparatus is applied to the plate surfaces 66 a and 66 b and the side surfaces 68 a and 68 b, that is, the entire circumferential direction of the press part 64. The sealing material 92 stagnates on the surface of the plating layer 74 and penetrates into the cracks in the plating layer 74 due to a capillary phenomenon.

  In the fourth step S40, the sealing material 92 is naturally dried at room temperature. Thereby, the solvent in the sealing material 92 evaporates. Further, although not shown, the terminal 54 is put into a heating furnace and a baking process is performed. In the baking process, for example, heating is performed at a temperature of about 150 ° C. for about 30 minutes. Thereby, since the raw rubber in the sealing material 92 is crosslinked, the sealing material 92 is cured and the sealing film 76 is formed as shown in FIG.

  The sealing film 76 is formed integrally with an outer edge portion 760 formed by the sealing material 92 stagnating on the surface of the plating layer 74 and a permeation portion 762 formed by the sealing material 92 that has permeated cracks in the plating layer 74. Has been. The outer edge portion 760 is formed thick at the central portion 60 and thin at the corner portion 62 due to the effect that the sealing material 92 is pulled from the corner portion 62 to the central portion 60 by tension when the sealing material 92 is applied. On the other hand, since the deeper crack is generated in the corner portion 62 than in the central portion 60, the penetration portion 762 is formed deeper in the corner portion 62. In addition, the location of the crack and the permeation portion 762 in FIG. 8 may be schematically shown larger than the actual size, and the direction in which the crack occurs is different from the actual due to the illustrated relationship. There is.

(Function and effect)
According to the present embodiment, after the terminal 54 is plated, the terminal 54 is bent so that a crack is generated in the press portion 64 of the terminal 54, so that a crack is generated in the plating layer 74 of the press portion 64. Further, since the liquid sealing material 92 is applied to the press part 64 thereafter, the sealing material 92 penetrates into the cracks of the plating layer 74 by capillary action, and the sealing film 76 adheres to the plating layer 74 with high adhesion due to the anchor effect. Is done. From the above, it is possible to provide a method for manufacturing the terminal 54 of the liquid level detection device 1 that improves the sealing performance between the terminal 54 and the covering portion 142.

  Further, according to the present embodiment, in the second step S20, another bent portion (for example, 70) bent to one plate surface (for example, 66b) side and another bent to the other plate surface (for example, 66a) side. Cracks are generated in any of the plate surfaces 66a and 66b and the side surfaces 68a and 68b of the terminal 54 by the press portion 64 where the bent portions (for example, 72a and 72b) are formed. Therefore, in any of the plate surfaces 66a and 66b and the side surfaces 68a and 68b, the seal film 76 is bonded to the plating layer 74 with high adhesion by the anchor effect. From the above, it is possible to provide a method for manufacturing the terminal 54 of the liquid level detection device 1 that improves the sealing performance between the terminal 54 and the covering portion 142.

  Further, according to the present embodiment, the plating formed thicker in the corner portion 62 than in the central portion 60 of the terminal 54 is likely to cause cracks in the corner portion 62, so that the seal film 76 is formed in the corner portion 62 of the terminal 54. Can also be bonded to the plating layer 74 with high adhesion.

  In addition, according to the present embodiment, the first step S10 performed together with plating on the portion other than the press portion 64 in the terminal 54 suppresses the addition of a process or production equipment different from the conventional one, and is desired. The terminal 54 of the liquid level detection device 1 can be realized.

  In addition, according to the present embodiment, the second step S20 performed together with the press processing of the portion other than the press portion 64 in the terminal 54 suppresses the addition of a process or production equipment different from the conventional one, and is desired. The terminal 54 of the liquid level detection device 1 can be realized.

(Other embodiments)
Although one embodiment of the present invention has been described above, the present invention is not construed as being limited to the embodiment, and can be applied to various embodiments without departing from the gist of the present invention. it can.

  Specifically, in the first modification, in the second step S20, the bending portion bent to one plate surface side in the press portion 64 and the other bending portion bent to the other plate surface side are not formed. May be. That is, if only a bent portion that is bent toward one of the plate surfaces is formed, a certain effect can be obtained. As a configuration including this example, for example, the press part 64 is bent at least at one place into an L shape.

  In the second modified example, in the first step S10, it is not necessary to perform plating on portions other than the press portion 64 in the terminal 54 together.

  In the modified example 3, in the second step S20, it is not necessary to perform the press work in the terminal 54 other than the press part 64.

  In the modified example 4, in the first step S <b> 10, the plating may be formed thinner at the corner portion 62 than at the central portion 60 of the terminal 54.

  In the modified example 5, in the first step S <b> 10, nickel plating as the first metal may be performed on the entire terminal 54, and then gold plating as the second metal may be performed on the terminal 54 other than the press portion 64.

DESCRIPTION OF SYMBOLS 1 Liquid level detection apparatus, 4 Liquid level, 142 Cover part, 54 Terminal, 60 Center part, 62 Corner part, 64 Press part, 66a, 66b Plate surface, 68a, 68b Side surface, 70, 72a, 72b Bending part, 74 Plating Layer, 76 sealing film, 92 sealing material

Claims (5)

In the liquid level detection device (1) for detecting the height of the liquid level (4) of the liquid,
A method of manufacturing a terminal (54) embedded in a covering part (142) and transmitting an electric signal related to detection of the height of the liquid level,
A first step (S10) of forming a plating layer (74) by plating the terminal;
After the first step, Oite the press section of the terminal (64), a second step of performing press working bending the terminal to produce a crack in the plated layer and (S20),
After the second step, a third step (S30) in which a liquid sealing material (92) is applied to the press portion, and the sealing material penetrates into the crack by capillary action;
A method for manufacturing a terminal of a liquid level detection device, comprising: a fourth step (S40) of curing the sealing material to form a sealing film (76) after the third step.
The plate-shaped press part has two side surfaces (68a, 68b) and two plate surfaces (66a, 66b) adjacent to the two side surfaces,
In the second step, a bent portion (70) bent to one plate surface (66b) side in the press portion and another bent portion (72a, 72b) bent to the other plate surface (66a) side. The method of manufacturing a terminal of the liquid level detection device according to claim 1, wherein:   The said 1st process WHEREIN: The said plating forms thicker in a corner | angular part (62) rather than the center part (60) of the said terminal, The manufacture of the terminal of the liquid level detection apparatus of Claim 1 or 2 characterized by the above-mentioned. Method.   4. The method of manufacturing a terminal of a liquid level detection device according to claim 1, wherein in the first step, plating is performed on a portion other than the press portion in the terminal. 5. .   5. The method of manufacturing a liquid level detection device terminal according to claim 1, wherein in the second step, a portion other than the press portion is pressed in the terminal.

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