JP2016024920A - Conduction structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conduction structure capable of restraining a grounding terminal for body grounding from being broken when rotating a collar that is disposed in a bolt insertion hole of a resin part, even without performing detent processing on the collar.SOLUTION: A through-hole 12 is formed in a flange part 10 (resin part) of an oil level sensor, and a metallic collar 13 is disposed in the through-hole 12. In the through-hole 12, a part from one surface 10a of the flange part 10 is formed to have a hole diameter larger than an outer diameter of the collar 13. A ground terminal (grounding terminal) includes a ring-shaped part 9a that is exposed to the surface 10a of the flange part 10. The collar 13 is disposed on the inside of the ring-shaped part 9a. A plurality of claw parts 9c are formed at an inner peripheral edge 9b of the ring-shaped part 9a. Each of the pawl parts 9c is disposed in a large diameter part 16 of the through-hole 12 and brought into contact with a side face 13c of the collar 13 in a state of being energized in a direction where the side face 13c is pushed. The ground terminal is not brought into contact with the collor 13 except for the pawl parts 9c.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a conduction structure that electrically connects a grounding terminal to a grounding part to which a resin part is fastened in order to ground a grounding terminal disposed in the resin part.

  Conventionally, in order to incorporate the ground potential on the resin part side, ground terminals are arranged at the fastening part (resin part) of the resin part, and the fastening part and the ground terminal are connected to the ground potential by fastening means such as bolts. There is known a technique for fastening together with a component (grounding component) to which is given (see, for example, Patent Documents 1 and 2). For example, in Patent Document 1, in an oil storage device, a grounding terminal is disposed on a reinforcing plate (fastening portion, resin portion) of an oil level sensor, and the grounding terminal is sandwiched between the reinforcing plate and the head of the fastening means. A technique for fastening and fixing the reinforcing plate and the grounding terminal together is disclosed. In Patent Document 1, a reinforcing conductive portion (a metal collar) is disposed in a hole of a reinforcing plate, and the grounding terminal is given a ground potential via the reinforcing conductive portion when fastened together. Electrically connected to the bracket.

  Patent Document 2 discloses that a nut (a metal collar) is disposed in a bolt insertion hole of a fastening portion, and the fastening portion and a connection terminal (grounding terminal) are fastened and fastened to a member to be fastened. . Moreover, the outer peripheral part of this nut becomes a level | step difference shape, and the connection terminal is arrange | positioned at the fastening part so that the inner periphery of a connection terminal may enter this level | step difference shape part.

JP 2012-246887 A JP 2006-9853 A

  By the way, when the resin portion where the metal collar is arranged is fastened by the fastening means, if the fastening means is tightened too much, the collar may rotate. In the configuration in which the grounding terminal is clamped together so as to be sandwiched between the collars as in Patent Document 1, if the collar rotates during overtightening, the grounding terminal also rotates and the grounding terminal may be broken. . In order to prevent the collar from rotating, it is conceivable that the collar is provided with a detent such as knurling, embossing, or making a hole. However, the cost of the detent is required.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a conduction structure that can prevent the grounding terminal from being broken during the rotation of the collar without the need to perform a rotation prevention process for the collar. To do.

In order to solve the above problems, the conduction structure of the present invention includes a resin portion in which a hole is formed,
A metal collar disposed in the hole and formed in a ring shape along the wall surface of the hole;
A grounding terminal disposed on the resin portion so as to contact the collar;
The collar is electrically connected to the grounding part when the resin part is fastened to a grounding part to which a ground potential is applied by fastening means inserted through the hollow part of the collar,
The grounding terminal has a claw portion that contacts a side surface of the collar, and is not in contact with the collar except for the claw portion.

  According to the present invention, since the grounding terminal has a claw part and the claw part is in contact with the side surface of the collar, when the resin part is fastened to the grounding part by the fastening means, the grounding terminal is It can be electrically connected to the grounding component through the collar. In addition, since the claw portion of the grounding terminal is in contact with the side surface of the collar and is not in contact with the collar otherwise, it is possible to avoid the tightening force applied by the fastening means from being applied to the grounding terminal. Therefore, even if the collar rotates, the ground terminal can be prevented from rotating, and the ground terminal can be prevented from breaking. In particular, according to the present invention, since the claw portion of the ground terminal is in contact with the side surface of the collar, it is easy to ensure contact pressure with the collar, and electrical connection between the ground terminal and the ground component can be ensured.

It is sectional drawing of an oil level sensor. It is an enlarged view of the A section of FIG. It is the figure which looked at the ring-shaped part and claw part of the collar and the earth terminal from the top. It is a top view of a ring-shaped part and a claw part concerning modification 1. 10 is an enlarged cross-sectional view of a flange portion according to Modification 2. FIG. 10 is an enlarged cross-sectional view of a flange portion according to Modification 3. FIG. It is an expanded sectional view of a flange part concerning modification 4.

  Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, the oil level sensor is connected to an oil pan in which oil for engine lubrication is stored, and detects the liquid level of the oil stored in the oil pan. An example in which the present invention is applied to the structure of FIG.

  FIG. 1 shows a cross-sectional view of the oil level sensor of the present embodiment. The oil level sensor 1 of FIG. 1 has a bottomed cylindrical resin cover 2 having a space formed therein. A cylindrical hollow portion 2 a is formed in the center of the cover 2, and a float 3 that moves on the outer periphery of the cylindrical hollow portion 2 a according to the oil level is disposed in the cover 2. The float 3 has a specific gravity smaller than that of oil, and moves up and down in the direction of the axis 2b (vertical direction in FIG. 1) of the cylindrical hollow portion 2a in accordance with fluctuations in the oil level.

  A sensor element including a reed switch 4 for detecting the position of the float 3 is provided in the cylindrical hollow portion 2a. The reed switch 4 is turned on / off according to the magnitude of the magnetic field from the permanent magnet 5 provided in the float 3.

  The reed switch 4 is provided with a movable metal piece (not shown) opposed to each other inside the glass container, and the movable metal piece is integrally formed with the leads 6 and 7, respectively. When the magnetic flux from the permanent magnet 5 flows to the movable metal piece inside the glass container, the attractive force overcomes the spring force of the movable metal piece, the movable metal pieces come into contact with each other, and a current flows between the leads 6 and 7. A signal line (not shown) is provided in parallel to the reed switch 4 inside the hollow cylindrical portion 2 a, and one end of this signal line is connected to the lead 7. The current flowing between the leads 6 and 7 is transmitted to the outside of the oil pan as a signal indicating the oil level through the signal line and the earth terminal 9 described later.

  The opposite lead 6 is fixed to an earth terminal 9 (grounding terminal). The ground terminal 9 is soldered to the lead 6. Details of the earth terminal 9 will be described later.

  A resin body 8 is connected to one end (upper side in FIG. 1) of the cover 2 in the vertical direction (the direction of the axis 2b). The body 8 has two flange portions 10 and 11 projecting to the side of the cover 2 (a direction perpendicular to the axis 2b) while supporting the cover 2 and the components disposed in the cover 2. One of the flange portions 10 and 11 is formed so as to protrude leftward in the left-right direction (side of the cover 2), and the other protrudes rightward.

  The flange portions 10 and 11 function as fastening portions for fastening the oil level sensor 1 to predetermined parts by fastening means such as bolts and screws. FIG. 2 shows an enlarged view of a portion A in FIG. 1 (an enlarged sectional view of the right flange portion 10). The flange portion 10 corresponds to the “resin portion” of the present invention. As shown in FIG. 2, the flange portion 10 is formed with a through hole 12 having a circular cross section that penetrates between both surfaces 10 a and 10 b in the thickness direction. In the through hole 12, a ring-shaped (cylindrical or hollow ring-shaped) collar 13 is disposed along the wall surface of the through-hole 12.

  The collar 13 is for reinforcing the through-hole 12 so that the resin constituting the wall surface of the through-hole 12 is not damaged when the flange portion 10 is fastened by the bolt 19 (see FIG. 1). The collar 13 is formed of a metal (conductive material) such as aluminum. The inner diameter of the collar 13 is slightly larger than the diameter of the bolt 19.

  In addition, one end face 13a of the collar 13 (an end face facing a bracket 17 (see FIG. 1) described later) is positioned at a height coincident with a surface 10a of the flange portion 10 (a face facing the bracket 17). . On the other hand, the other end surface 13 b of the collar 13 is located at a height that slightly protrudes from the surface 10 b on the opposite side of the flange portion 10. A collar having the same shape as the collar 13 disposed on the flange portion 10 is also disposed on the flange portion 11 (see FIG. 1) on the opposite side.

  The earth terminal 9 is formed integrally with the body 8 and the flange portion 10 by insert molding. The earth terminal 9 is formed from a thin metal plate, and a portion disposed in the body 8 and a portion disposed so as to be bent from the portion to the surface 10a side of the flange portion 10 and exposed to the surface 10a. 9a. Here, FIG. 3 shows a view (viewed from above) of the exposed portion 9 a of the collar 13 and the ground terminal 9 shown in FIG. 2 as viewed from the surface 10 a side of the flange portion 10. As shown in FIG. 3, the exposed portion 9 a of the earth terminal 9 is formed in a ring shape so as to surround the end face 13 a of the collar 13 outside the collar 13. Hereinafter, the exposed portion 9a is referred to as a ring-shaped portion. The inner peripheral edge 9 b of the ring-shaped portion 9 a is formed in a circular shape having a center at a position substantially coinciding with the central axis 14 of the collar 13 and a diameter larger than the outer diameter of the collar 13.

  As shown in FIG. 2, the through-hole 12 of the flange portion 10 is partially formed from the surface 10 a with a large diameter. The large diameter portion 16 of the through hole 12 has a diameter larger than the outer diameter of the collar 13. Therefore, the wall surface of the large diameter portion 16 is not in contact with the side surface (outer peripheral surface) 13 c of the collar 13, and a space is formed inside the large diameter portion 16.

  The earth terminal 9 has a claw portion 9c connected to the inner peripheral edge 9b of the ring-shaped portion 9a. As shown in FIG. 3, a plurality of claw portions 9c (eight in FIG. 3) are formed at equal intervals along the inner peripheral edge 9b. The claw portion 9c is formed integrally with the ring-shaped portion 9a. Each claw portion 9 c is formed so as to be bent from the inner peripheral edge 9 b toward the large diameter portion 16, and is located in the large diameter portion 16. Each claw portion 9c is formed in a triangular shape having one side connected to the inner peripheral edge 9b, as shown in FIG.

  A part of the tip side of the triangular claw portion 9 c is in contact with the side surface 13 c of the collar 13. Specifically, the claw portion 9c is in contact with the side surface 13c while being urged in a direction P (see FIG. 2) for pushing the side surface 13c of the collar 13 (a state in which a spring force is applied). That is, when the collar 13 is removed, the claw portion 9c is displaced so as to fall down in the direction of the height position of the ring-shaped portion 9a with the connection portion with the inner peripheral edge 9b as a fulcrum. The ground terminal 9 is not in contact with the collar 13 except for the claw portion 9c.

  The earth terminal 9 and the collar 13 are integrated with the body 8 (flange portion 10) by insert molding, for example. An example of a manufacturing method of the flange portion 10 in which the earth terminal 9 and the collar 13 are arranged will be described. First, the earth terminal 9 and the collar 13 are prepared in advance. The distance between the two claw portions 9 c in the positional relationship of the prepared ground terminal 9 is smaller than the outer diameter of the collar 13. Thereafter, the collar 13 is inserted inside the ring-shaped portion 9 a of the earth terminal 9. At this time, the claw portion 9c is displaced by the side surface 13c of the collar 13 in the rising direction, so that the claw portion 9c is biased to the side surface 13c. Thereafter, the combination of the earth terminal 9 and the collar 13 is placed in the mold of the body 8 (flange portion 10), and the resin 8 is poured into the mold so that the body 8 integrated with the earth terminal 9 and the collar 13 ( A flange portion 10) can be formed.

  Note that the earth terminal 9 and the body 8 (flange portion 10) may be first insert-molded, and then the collar 13 may be press-fitted into the through-hole 12 of the flange portion 10 in this insert-molded product.

  As shown in FIG. 1, the oil level sensor 1 is fastened by a bolt 19 to a bracket 17 connected to, for example, an engine block (not shown). The bracket 17 is formed of metal at least a portion (for example, the inner wall of the bolt insertion hole 18) with which the collar 13 and the bolt 19 are in contact, and the metal portion of the bracket 17 is given a potential of the engine block, that is, a ground potential. ing. The oil level sensor 1 may be directly fastened to the engine block or may be fastened to other parts to which a ground potential is applied. The bracket 17 corresponds to the “grounding component” of the present invention.

  A bolt insertion hole 18 is formed in the bracket 17, and the bolt insertion hole 15 (the hollow portion of the collar 13) of the oil level sensor 1 is aligned with the bolt insertion hole 18. At this time, the ring-shaped portion a is sandwiched between the flange portion 10 and the bracket 17 so that the surface 10a of the flange portion 10 on which the ring-shaped portion 9a is disposed faces the bracket 17 side. After that, the bolt 19 is inserted into the bolt insertion hole 15 from the surface 10b side opposite to the flange portion 10, and the bolt 19 is engaged with a nut (not shown) arranged on the bracket 17 side. Is fastened to the bracket 17. The flange 11 on the opposite side is also fastened to a predetermined part with a bolt.

  Thereby, the oil level sensor 1 can be fixed in the oil pan. Further, the collar 13 is brought into contact with the bracket 17 by the end surface 13a of the collar 13 being in direct contact with the bracket 17 to which a ground potential is applied or by the collar 13 being indirectly in contact with the bracket 17 through the bolt 19. Electrically conducted and a ground potential is applied. As a result, the ground terminal 9 in contact with the side surface 13c of the collar 13 is also electrically connected to the bracket 17, and a ground potential is applied.

  Further, since the earth terminal 9 is in contact with the side surface 13c of the collar 13 at the claw portion 9c and is not in contact with other portions, it is possible to avoid the tightening force by the bolt 19 from being applied to the earth terminal 9. Therefore, even if the collar 13 rotates when the bolt 19 is over-tightened, the earth terminal 9 can be prevented from rotating, and the earth terminal 9 can be prevented from breaking. Further, since the rotation prevention processing such as knurling and embossing for the collar 13 can be abolished, the cost of the rotation prevention processing can be reduced. It should be noted that the collar 13 may be prevented from rotating, and in this case, the breakage of the ground terminal 9 can be further suppressed.

  Moreover, in the said embodiment, since the nail | claw part 9c is formed in the triangle shape and is contacting the side surface 13c of the collar 13 in the urged | biased state, it suppresses that a contact area with the side surface 13c increases. The contact pressure with the side surface 13c can be improved. That is, the claw portion 9c can be brought into good contact with the side surface 13c. Therefore, the ground terminal 9 can be reliably connected. In addition, since a plurality of claw portions 9c are formed around the collar 13, the ground terminal 9 can be reliably connected.

  Further, the earth terminal 9 has a ring-shaped portion 9 a exposed on the surface 10 a of the flange portion 10 around the bolt insertion hole 15, and the ring-shaped portion 9 a is sandwiched between the flange portion 10 and the bracket 17. Therefore, the earth terminal 9 (ring-shaped portion 9 a) can be fastened to the bracket 17 together with the flange portion 10.

(Modification 1)
In the above embodiment, the shape of the claw portion of the earth terminal is triangular, but this claw portion may have a shape other than the triangular shape as shown in FIG. FIG. 4 is a plan view of the ring-shaped portion 20 in the ground terminal according to the first modification. As shown in FIG. 4, a plurality of claw portions 22 are formed on the inner peripheral edge 21 of the ring-shaped portion 20. Each nail | claw part 22 is formed in the substantially square shape. Also by this, the same effect as the above embodiment can be obtained.

(Modification 2)
In the above embodiment, an example in which the ring-shaped portion and the claw portion of the ground terminal are disposed on the surface of the flange portion on the bracket side has been described, but these may be disposed on the surface of the bolt insertion side. FIG. 5 shows an enlarged cross-sectional view of the flange portion when the ring-shaped portion and the claw portion are arranged on the surface of the flange portion on the bolt insertion side. As shown in FIG. 5, the ring-shaped portion 24 of the ground terminal is disposed on the surface 10b on the bolt insertion side of the flange portion 10, and the large-diameter portion 23 of the through hole is formed on the surface 10b side. Then, the claw portion 25 is disposed on the large diameter portion 23, and the claw portion 25 is brought into contact with the side surface of the collar 13. The ring-shaped portion 24 is fastened together by being clamped between the head portion of the bolt and the flange portion 10. Also by this, the same effect as the above embodiment can be obtained.

(Modification 3)
Moreover, as shown in FIG. 6, you may arrange | position the ring-shaped part and nail | claw part of an earthing terminal inside a flange part. FIG. 6 is an enlarged cross-sectional view of the flange portion according to the third modification. As shown in FIG. 6, a space portion 26 is formed inside the flange portion 10, and a ring-shaped portion 27 and a claw portion 28 of an earth terminal are disposed in the space portion 26. The claw portion 28 is in contact with the side surface 13 c of the collar 13 inside the flange portion 10. Also by this, the same effect as the above embodiment can be obtained.

(Modification 4)
In the above embodiment, with the collar removed, the gap between the two opposing claws is made smaller than the outer diameter of the collar, so that a biasing force is applied to the claws when the collar is assembled. As shown in FIG. 7, a protrusion may be formed on the side surface of the collar, and the claw portion may be brought into contact with the protrusion. FIG. 7 shows an enlarged cross-sectional view of the flange portion according to Modification 4. As shown in FIG. 7, a protruding portion 13 d is formed on the side surface 13 c of the collar 13 in the large diameter portion 29 in the through hole of the flange portion 10. The claw portion 31 connected to the inner peripheral edge of the ring-shaped portion 30 is in contact with the protruding portion 13 d in the large diameter portion 29. At this time, the claw portion 31 receives a force F1 in a direction away from the projection 13d from the side surface 13c, and the claw portion 31 is urged in a direction to push the side surface 13c as a reaction force F2 of the force F1. Also by this, the same effect as the above embodiment can be obtained. In addition, you may form a projection part in the nail | claw part side.

  In addition, this invention is not necessarily limited to the said embodiment, A various change is possible in the limit which does not deviate from description of a claim. For example, in the above embodiment, an example in which a plurality of claw portions are formed on the earth terminal has been described, but the number of claw portions may be one. According to this, the configuration of the earth terminal can be simplified.

  Moreover, although the example which inserted the volt | bolt from the flange part side was demonstrated in the said embodiment, you may insert a volt | bolt from the bracket side. Further, the present invention may be applied to a body earth structure (conduction structure) in products other than the oil level sensor.

1 Oil level sensor 9 Earth terminal (grounding terminal)
9c, 22, 25, 28, 31 Claw part 10 Flange part (resin part)
12 Through hole (hole)
13 Color 13c Color side 15 Bolt insertion hole (color hollow)
17 Bracket (grounding part)
19 bolts (fastening means)

Claims (4)

A resin part (10) in which a hole (12) is formed;
A metal collar (13) disposed in the hole and formed in a ring shape along the wall surface of the hole;
A grounding terminal (9) disposed on the resin portion so as to contact the collar;
The collar is electrically connected to the grounding part when the resin part is fastened to the grounding part (17) to which a ground potential is applied by the fastening means (19) inserted through the hollow part (15) of the collar. Conducted to
The grounding terminal has a claw portion (9c, 22, 25, 28, 31) that contacts the side surface (13c) of the collar, and is not in contact with the collar other than the claw portion. Conductive structure characterized by   The conductive structure according to claim 1, wherein the claw portion is in contact with the side surface in a state where the claw portion is biased in a direction of pressing the side surface of the collar.   The grounding terminal has a ring-shaped portion (9b, 20, 24, 27, 30), the collar is disposed inside the ring-shaped portion, and the claw portion has an inner peripheral edge (9b, 21. The conductive structure according to claim 1, wherein one or a plurality of the conductive structures are formed along 21). The ring-shaped part (9b, 24, 30) is arranged in a form exposed on the surface (10a, 10b) of the resin part around one end face of the collar,
The hole of the resin portion is formed with a hole diameter that is partly larger than the outer diameter of the collar,
The said nail | claw part (9c, 25, 31) is arrange | positioned in the part (16, 23, 29) formed in the hole diameter larger than the outer diameter of the said collar in the hole of the said resin part. Item 4. The conduction structure according to Item 3.

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