JP5071501B2 - Manufacturing method of electrical device - Google Patents

Description

  The present invention relates to an electric device in which electronic parts, terminals, and the like are insert-molded with a resin material. It is suitable to apply.

  As this type of conventional electric device, for example, there is one applied to a liquid level detection device. That is, the vertical movement of the float floating on the liquid surface is transmitted through the arm, the magnet is fixed in the rotating member that rotates, and the Hall element that is a magnetoelectric conversion element is disposed in the fixing member that rotatably holds the rotating member This is applied to a fixing member of a liquid level detecting device (see Patent Document 1).

  As a fixing member of the liquid level detection device as the conventional electric device, a Hall element as a magnetoelectric conversion element and a terminal to which the Hall element is electrically connected are insert-molded at a predetermined position in the resin material. Here, the tip of the terminal is exposed to the outside of the resin material so as to be connectable to an external electric circuit, whereby the Hall element is connected to the external electric circuit. In the middle of the terminal in the longitudinal direction, a rubber material is disposed so as to cover the entire circumference of the terminal, and this rubber material is also insert-molded into the resin material.

  The fixing member of the above-described liquid level detection device, which is a conventional electric device, is attached to a position lower than the fuel level position when the tank is full in the fuel tank. Accordingly, the fixing member is completely immersed in the fuel from the time when the fuel tank is full until the liquid level reaches a predetermined position. Further, even if the liquid level is lower than the fixing member, the liquid level is swung by the vibration of the automobile, so that the liquid level is immersed in the fuel or the fuel droplets adhere.

  By the way, since the thermal expansion coefficients of the metal terminal and the resin material are different from each other, a gap may be formed between the terminal and the resin material in the process of using the liquid level detection device. There is a possibility that fuel enters the gap and reaches the hall element, which corrodes the hall element and prevents normal operation.

  Therefore, in the above-described fixing member, the rubber material is disposed so as to cover the entire periphery of the terminal in the middle of the terminal and in the resin material. When the rubber material is insert-molded into the resin material, the rubber material is compressed and deformed under the injection pressure of the resin material. This elastic force increases the surface pressure of the contact portion between the rubber material and the resin material, and improves the sealing performance between the two. Accordingly, the fuel that has entered the resin material is prevented from reaching the Hall element.

Japanese Patent Laid-Open No. 2005-10043

  In the fixing member as the conventional electric device applied to the liquid level detection device described above, the force for compressing and elastically deforming the rubber material depends on the molding pressure of the resin material. This molding pressure has a large variation, and there is a problem that it is difficult to stably maintain the sealing performance.

  The present invention has been made in view of such problems, and its purpose is to reliably prevent liquid that has entered the resin material from reaching the electronic component via the gap between the terminal and the resin material. It is to provide a method for manufacturing an electrical device.

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

That is, in the invention according to claim 1, the electronic component, the terminal made of the electric conductor of the flat metal plate to which the electronic component is connected, and the insert molding is performed so as to cover the entire circumference of the terminal in a part of the terminal in the longitudinal direction. And a flexible resin material arranged in close contact with each other, and a casing for holding and fixing the electronic component, the terminal, and the flexible resin material. The casing is formed by insert molding the electronic component, the terminal, and the flexible resin material with the resin material. The end opposite to the electronic component is extended outside the casing, a part of the flexible resin material is covered with the casing and the remaining part is exposed outside the casing, and the flexible resin material is in the longitudinal direction of the terminal in the vicinity of the end face of the casing. A method of manufacturing an electrical device compressed in an orthogonal direction,
An adhesion process in which a flexible resin material is closely fixed to the terminal by insert molding, a connection process in which an electronic component is electrically connected to the terminal after the adhesion process to form an electronic component subassembly, and a casing is molded after the connection process. The molding process includes a holding process for holding the electronic component subassembly in the cavity of the molding die while pressing and compressing the flexible resin material with the mold of the casing, and a resin in the cavity after the holding process. It is characterized by comprising a filling step for filling the material, a solidification step for solidifying the resin material in the cavity, and a release step for removing the casing molded after the solidification step from the mold.

  According to this invention, the compressibility of the flexible resin material can be maintained by providing the above steps. Accordingly, the surface pressure between the flexible resin material and the casing in the vicinity of the mold contact portion of the flexible resin material is maintained at a desired value, that is, a value that exhibits good sealing performance, and liquid around the electronic component is maintained. It is possible to provide a manufacturing method capable of easily manufacturing an electric device that can reliably prevent the intrusion of the liquid.

  Further, in the electrical device manufactured in this way, a part of the flexible resin material is exposed to the outside of the casing. Therefore, when the casing is resin-molded, the flexible resin material is pressed by the mold when the mold is clamped. Can be compressed.

  That is, in the conventional electric device, the rubber which is the flexible resin material is compressed by the resin pressure at the time of resin molding. According to the electric device obtained by the method of the present invention, the molding die is formed at the time of resin molding of the casing. Therefore, the compression rate of the flexible resin material can be maintained. The surface pressure between the flexible resin material and the casing in the vicinity of the mold contact portion of the flexible resin material can be maintained at a desired value, that is, a value that exhibits good sealing performance. Thereby, the electric device which can prevent reliably that the liquid which infiltrated into the resin material via the clearance gap between a terminal and the resin material reaches | attains an electronic component can be manufactured.

  The invention described in claim 2 is characterized in that rubber is used for the flexible resin material.

  According to this invention, in addition to the above effects, rubber is used for the flexible resin material. Therefore, there are a wide variety of rubbers, and appropriate liquids that exhibit hardness (related to elasticity) and corrosion resistance should be selected appropriately. For example, according to the type of liquid in which the electric device is immersed, the electric device that can reliably prevent the liquid that has entered the resin material from always reaching the electronic component through the gap between the terminal and the resin material. Can be manufactured.

It is a front view of fuel level gauge 100 provided with body 3 which is an electric device by one embodiment of the present invention. It is the II-II sectional view taken on the line in FIG. It is sectional drawing which shows schematic structure of the metal mold | die 200 used for manufacture of the casing 20 of the body 10 which is an electric device by one Embodiment of this invention. It is the IV-IV sectional view taken on the line in FIG. FIG. 6 is a schematic diagram illustrating a magnetic flux distribution of a magnet.

(One embodiment)
Hereinafter, the electric device according to the embodiment of the present invention is applied to the body 3 that is a component of the fuel level gauge 100 that is mounted in a fuel tank of an automobile and detects the level of the fuel. This will be explained based on. In addition, the same code | symbol is attached | subjected to the same component in each figure.

  FIG. 1 is a front view of a fuel level gauge 100 including a body 3 that is an electric device according to an embodiment of the present invention. FIG. 1 shows a state in which the liquid level Fa of the fuel F is at the lowest level. Moreover, in FIG. 1, each position of the liquid level Fa, the float 4, and the arm 5 at the time of a full tank is shown with the broken line.

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

  In FIGS. 1 and 2, the upper side of the figure is the upper side in the usage state of the fuel level gauge 100.

  FIG. 3 is a cross-sectional view showing a schematic structure of a mold 200 used for manufacturing the casing 20 of the body 10 which is an electric apparatus according to an embodiment of the present invention.

  4 is a cross-sectional view taken along line IV-IV in FIG.

  FIG. 5 is a schematic diagram for explaining the magnetic flux distribution of the magnet 102.

  First, the configuration of the fuel level gauge 100 will be described.

  As shown in FIG. 1 and FIG. 2, the fuel level gauge 100 is roughly configured such that the other end of an arm 104 having a float 103 fixed to the tip is fixed to a magnet holder 101, and this magnet holder 101 is an electric device. The body 10 is configured to be rotatably held. The float 103 always floats on the liquid level Fa of the fuel F and moves together with the liquid level Fa. The movement of the float 103, that is, the vertical movement of the liquid level Fa position is converted into the rotational movement of the magnet holder 101 via the arm 104. A magnet 102 is built in the magnet holder 101, and a hall element 30 as an electronic component is built in the body 10 at a position where it crosses the magnetic flux of the magnet 102. The Hall element 30 converts a change in magnetic flux density across the Hall element 30 into a change in electric signal level. Therefore, when the magnet holder 101 rotates in conjunction with a change in the liquid level Fa of the fuel F, the Hall element 30 in the body 10 is rotated. The output signal level from is changed. That is, the fuel level gauge 100 detects the position of the liquid level Fa as an electrical signal from the Hall element 30.

  The magnet holder 101 is formed of, for example, a resin material in a substantially ring shape as shown in FIG. 1 and its hole 101a is rotatably fitted to a shaft portion 21 of the body 10 described later as shown in FIG. Match. As shown in FIG. 2, a magnet 102 is built in the magnet holder 101.

  The magnet 102 is made of, for example, a ferrite magnet, and a cylindrical type is used in the fuel level gauge 100 according to one embodiment of the present invention, and is arranged concentrically with the hole 101a as shown in FIG. . As shown in FIG. 5, the magnet 102 is two-pole magnetized. The magnetic flux M of the magnet 102 is distributed as shown in FIG. 5, and the magnetic flux on the inner peripheral side of the magnet 102 flows in the radial direction of the hole 101a. Further, in the fuel level gauge 100 according to one embodiment of the present invention, the magnet 102 is insert-molded integrally in the magnet holder 101 when the magnet holder 101 is resin-molded. The method for fixing the magnet to the magnet holder need not be limited to insert molding, and may be a mechanical coupling method such as snap fit.

  The arm 104 is formed of a metal material, for example, a stainless steel round bar. As shown in FIG. 1, the float 103 is fixed to one end side of the arm 104, and the other end side of the arm 104 is fixed to the magnet holder 101.

  The float 103 is formed in a three-dimensional shape from a resin material or the like, and has an apparent specific gravity so as to surely float on the liquid surface Fa of the fuel F when attached to the arm 104. When the float 103 moves up and down according to the change in the position of the liquid level Fa, this movement is transmitted to the magnet holder 101 by the arm 104, and the magnet holder 101 rotates relative to the body 10.

  The body 10, which is an electric device, is formed by accommodating and fixing the Hall element 30, the terminal 40, and the like in a casing 20 made of a resin material. As shown in FIG. 2, the body 10 includes a shaft portion 21 that protrudes in a cylindrical shape, and the shaft portion 21 is fitted in the hole portion 101 a of the magnet holder 101. In order to prevent the magnet holder 101 from being detached from the shaft portion 21 after the magnet holder 101 is mounted on the shaft portion 21, a retaining means (not shown) is provided. For example, the retaining means is constituted by a groove (not shown) and a snap ring (not shown) provided at the tip of the shaft portion 21, and after the magnet holder 101 is mounted on the shaft portion 21, the snap ring (Not shown) may be fitted into a groove (not shown). By abutting against this snap ring (not shown), movement of the magnet holder 101 in a direction away from the body 10 (movement toward the left side in FIG. 2) is restricted. As shown in FIG. 2, a hall element 30 as an electronic component is accommodated in the shaft portion 21. Specifically, as shown in FIG. 2, the Hall element 30 is accommodated in a holder 50 that is a sheath member, and the holder 50 is accommodated in a shaft portion 32 provided in the casing 20. The holder 50 is formed by molding from a resin material. In the molding process of the holder 50, a terminal 40 described later is insert-molded, and the holder 50 and the terminal 40 are integrated in advance.

  Here, the Hall element 30 will be briefly described.

  The Hall element 30 is made of a semiconductor, and a magnetic field is applied from the outside while a voltage is applied to the Hall element 30. In other words, when the magnetic flux M crosses the Hall element 30, the Hall element 30 is proportional to the magnetic flux density passing through the Hall element 30. Generates Hall voltage. That is, when the Hall element 30 and the magnetic flux M are orthogonal, the magnetic flux density passing through the Hall element 30 is maximized, and the Hall voltage is maximized. When the Hall element 30 and the magnetic flux M are parallel, the magnetic flux density passing through the Hall element 30 is minimized and the Hall voltage is minimized.

  In the fuel level gauge 100 according to the embodiment of the present invention, when the magnet holder 101 rotates due to the fluctuation of the liquid level Fa, the magnet 102 rotates with respect to the Hall element 30. As a result, the crossing angle between the Hall element 30 and the magnetic flux M generated by the magnet 102 changes, and the Hall voltage that is the output voltage of the Hall element 30 changes. By detecting the Hall voltage, the rotation angle of the magnet holder 101, that is, the position of the liquid surface Fa which is the position of the float 103 is measured.

  The Hall element 30 incorporated in the body 10 according to the embodiment of the present invention includes three leads 31 that are electrodes. That is, there are three: a + lead 31a connected to the positive pole of the power source, a negative lead 31b connected to the negative pole of the power source, and an output lead 31c that outputs the Hall voltage. Corresponding to these three leads 31, the body 10 includes three terminals 40 as shown in FIG.

  The terminal 40 is formed by pressing an electric conductor, for example, a highly conductive metal. As shown in FIG. 2, one end of each terminal 40 is electrically connected to the lead 31 of the Hall element 30, and the other end extends to the outside of the casing 20. As shown in FIG. 2, a seal member 60, which is a rubber as a flexible resin material, covers the entire periphery of the terminal 40 and is fixed in close contact with a portion of the terminal 40 in the longitudinal direction (vertical direction in FIG. 2). . The seal member 60 is made of a rubber material that is excellent in resistance to the fuel F that is the liquid level detection target of the fuel level gauge 100. The seal member 60 collectively covers the three terminals 40 as a continuous integral part. The seal member 60 is fixed to the terminal 40 by, for example, baking. That is, the terminal 40 is insert-molded in the molding die of the seal member 60 and integrated with the terminal 40.

  As shown in FIG. 2, a part of the seal member 60 is in the casing 20 and the remaining part is exposed to the outside of the casing 20. Further, as shown in FIG. 2, the seal member 60 is compressed in the direction (left and right direction in FIG. 2) perpendicular to the longitudinal direction of the terminal 40 in the vicinity of the end surface 21 of the casing 20. That is, as shown in FIG. 2, the height from the surface of the terminal 40 to the outer surface of the seal member 60 becomes smaller as it approaches the end surface of the casing 20.

  Next, the manufacturing method of the body 10 by one Embodiment of this invention is demonstrated.

  First, an attaching step for tightly fixing the sealing member 60 to the terminal 40 is performed. That is, the terminal 40 is set in the molding die of the seal member 60 and insert molding is performed. Thereby, the sealing member 60 adheres firmly to the surface of the terminal 40, and both are integrated.

  Next, a first molding step is performed in which the holder 50 is molded from a resin material and simultaneously fixed to the terminal 40.

  Here, if the three terminals 40 are molded as one part partially connected by a bridge portion by press working, and the bridge portion is cut by press working or the like after the attaching step or after the first forming step, The workability of the attaching process and the first molding process can be improved.

  Next, the Hall element 30 is accommodated in the holder 50, and the leads 31a to 31c of the Hall element 30 are electrically connected to the corresponding terminals 40, so that the Hall element 30, the terminal 40, the holder 50, and the seal member 60 are provided. A connecting step for forming the integrated subassembly S is performed. The electrical connection between the leads 31 to 33 of the hall element 30 and the terminal 40 is performed by welding, for example.

  Next, a second molding step for molding the casing 20 is performed. In the second molding step, the subassembly S completed in the above connection step is set in a molding die in the casing 20 and insert molded.

  This second molding step will be described in detail below.

  In FIG. 3, the schematic structure of the metal mold | die 200 used for manufacture of the casing 20 in a 2nd shaping | molding process is shown. FIG. 3 shows a state when the mold 200 is completely clamped, that is, a state immediately before resin filling. FIG. 3 shows the casing 20 in a posture rotated 90 degrees clockwise from the state shown in FIG.

  The mold 200 generally includes an upper mold 201, a lower mold 202, and slide cores 203 and 204, as shown in FIG. When the mold 200 is clamped, the slide cores 203 and 204 are advanced in the left-right direction in FIG. 4 on the surface 202a of the lower mold 202 by the action of an inclined pin (not shown) provided in the mold 200. The slide core 203 advances from the left side to the right side in FIG. 4, and the slide core 204 advances from the right side to the left side in FIG. 4, and stops at the position shown in FIG. The slide cores 203 and 204 together with the upper mold 201 and the lower mold 202 form a cavity (product portion, that is, a portion that becomes the substance of the casing 20) 205.

  The upper mold 201 is formed with a sprue 206 as a supply passage for the resin filled from the gate 206 into the cavity 205, and the lower mold 202 is provided with a casing 20 which is a resin molded product after the molding is completed. A knockout pin 208 for releasing from 202 is attached.

  Next, a method for manufacturing the casing 20 using the mold 200 having the above configuration will be described.

  First, in the state before the mold 200 is clamped, that is, the upper mold 201 and the lower mold 202 are separated in the vertical direction in FIG. 3, and the slide cores 203 and 204 are moved to the left and right in FIG. In the state of being in contact with the lower mold 202, the sub-assembly S as an insert part that is insert-molded into the casing 20, that is, the Hall element 30, the terminal 40, the holder 50, and the seal member 60 are integrated into the cavity 205. It is arranged in the inside.

  Next, the mold 200 is clamped. That is, the lower mold 202 and the slide cores 203 and 204 are moved upward in FIG. At this time, the slide core 203 advances from the left side to the right side in FIG. 4, and the slide core 204 advances from the right side to the left side in FIG. 4, and stops at the position shown in FIG.

  Thus, the holding process for holding the subassembly S in the cavity 205 is completed.

  In this state, the seal member 60 is compressed in the vertical direction in FIG. 4 by the upper mold 201 and the lower mold 202, and simultaneously compressed in the horizontal direction in FIG. 4 by the slide cores 203 and 204. That is, when the holding process is completed, the seal member 60 is compressed from the natural state indicated by the two-dot chain line in FIG. 4 to the shape indicated by the solid line on the entire circumference. At this time, the compression ratio of the seal member 60 is maximized in the portion that is in contact with each of the molds 201 to 204, and in the portion that is not in contact with each of the molds 201 to 204, that is, the portion in the cavity 205. It gradually decreases as the distance from 204 increases.

  As shown in FIG. 3, after the subassembly S is held in the cavity 205 of the mold 200, the nozzle part of the injection unit (not shown) is then brought into contact with the upper end of the sprue 206 of the upper mold 201 to melt the subassembly S. The liquid resin thus injected is injected to fill the cavity 205 from the gate 207 with the molten resin. When the resin completely reaches the cavity 205 or the sprue 206 is filled with the resin, the injection of the resin is stopped and the filling process is completed.

  The resin filled in the cavity 205 is absorbed by the mold 200 and gradually cooled and solidified from a portion in contact with the inner surface of the cavity 205. The resin is cooled and solidified to form the casing 20. This completes the solidification process.

  Next, the lower mold 202 and the slide cores 203 and 204 are moved downward in FIG. At this time, the slide core 203 simultaneously moves to the left in FIG. 4, and the slide core 204 moves to the right in FIG.

  Subsequently, the knockout pin 208 is moved upward in FIG. 3 to release the casing 20 from the lower mold 202.

  Thus, the manufacture of the casing 20 of the body 10 according to the embodiment of the present invention is completed.

  Here, when the mold release process is completed, the molds 201 to 204 are separated from the seal member 60, and the force acting on the seal member 60 at the contact surface with the molds 201 to 204, that is, the force in the compression direction is released. Is done. However, the portion in the cavity 205 of the seal member 60 is maintained in a compressed shape at the end of the holding process by the solidified resin material, that is, the casing 20. Therefore, in this portion, the surface pressure at the contact surface between the seal member 60 and the casing 20 is high due to the elastic force of the seal member 60. At the same time, the contact pressure at the contact surface between the seal member 60 and the terminal 40 is also increased.

  In the body 10 according to the embodiment of the present invention described above, in the manufacturing process of the casing 20, specifically, the holding process of holding the subassembly S in the mold 200, the sealing member 60 is moved by the molds 201 to 204. By compressing in the entire circumferential direction, the sealing member 60 is maintained in the compressed state by the casing 20 in the completed state of the body 10.

  As a result, when the fuel level gauge 100 is used, the fuel F enters the casing 20 from between the seal member 60 and the casing 20 and between the seal member 60 and the terminal 40 when the body 10 is immersed in the fuel F. Intrusion can be reliably prevented.

  Further, in the body 10 according to the embodiment of the present invention described above, insert molding is performed when the casing 20 is molded in a state where the Hall element 30 is stored in the holder 50 in advance.

  According to this configuration, since the Hall element 30 is not in direct contact with the molten resin injected when the casing 20 is molded, it is possible to prevent the Hall element 30 from being deteriorated due to heat. Further, the posture of the Hall element 30 can be prevented from changing under the pressure of the injected molten resin, and the posture and position of the Hall element 30 in the casing 20 can be maintained with high accuracy.

(Other embodiments)
In the body 10 according to the embodiment of the present invention described above, the Hall element 30 which is a so-called magnetoelectric conversion element that converts a change in magnetic flux into an electric signal is used as an electronic component. Alternatively, other types of magnetoelectric conversion elements such as an MRE element (magnetic resistance element) or a magnetic diode may be used.

  Moreover, in the body 10 by the position embodiment of this invention demonstrated above, although the holder 50 is provided and it insert-molds in the casing 20 in the state which accommodated the Hall element 30 in the holder 50, the holder 50 is used without fail. There is no need. The holder 50 may not be used depending on various conditions such as the heat resistance temperature of the electronic component to be used and the melting temperature of the molding resin of the casing 20.

  In the embodiment of the present invention described above, the case where the electric device according to the present invention is applied to the body 10 of the fuel level gauge 100 has been described as an example. However, the electric device according to the present invention may be applied to other types of electric devices. Good. In particular, when applied to an electric device used in a state of being immersed in a liquid, the same effect as that of the body 10, that is, an effect that the liquid intrusion into the casing from the terminal protruding portion of the casing can be surely suppressed can be obtained. It is done.

10 Body (Electric device)
20 Casing (resin material)
21 Shaft part 22 Groove part 30 Hall element (magnetoelectric conversion element)
31a, 31b, 31c Lead 40 Terminal 50 Holder (sheath member)
60 Seal member (flexible resin material, rubber)
100 Fuel level gauge 101 Magnet holder (rotating member)
101a hole 102 magnet 103 float 104 arm 105 snap ring 200 mold 201 upper mold 202 lower mold 203 slide core 204 slide core 205 cavity 206 sprue 207 gate 208 knockout pin F fuel Fa liquid level M magnetic flux

Claims (2)

An electronic component, a terminal made of an electric conductor of a flat metal plate to which the electronic component is connected, and a flexible resin that is insert-molded so as to cover the entire circumference of the terminal in a part in the longitudinal direction of the terminal And a casing for holding and fixing the electronic component, the terminal, and the flexible resin material. The casing is formed by insert molding the electronic component, the terminal, and the flexible resin material with a resin material, and the terminal. The end portion opposite to the electronic component is extended outside the casing, a part of the flexible resin material is covered with the casing and the remaining portion is exposed outside the casing, and the flexible resin material is an end surface of the casing. In the manufacturing method of the electric device compressed in the direction orthogonal to the longitudinal direction of the terminal in the vicinity portion I,
An adhesion step of tightly fixing the flexible resin material to the terminal by the insert molding;
A connecting step of electrically connecting the electronic component to the terminal after the attaching step to form an electronic component subassembly;
A molding step of molding the casing after the connection step;
The molding step includes a holding step of holding the electronic component subassembly in the cavity of the molding die while pressing and compressing the flexible resin material by the molding die of the casing.
A filling step of filling the cavity with a resin material after the holding step;
A solidification step of solidifying the resin material in the cavity;
A method for manufacturing an electrical device, comprising: a mold release step for removing the casing molded after the solidification step from the mold.   2. The method of manufacturing an electric device according to claim 1, wherein rubber is used for the flexible resin material.

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