JP2017016809A - Ground terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely mesh a part of a ground terminal into a metal surface of a body by breaking a non-conductive film.SOLUTION: A ground terminal 10 is fitted to a body 80 that is formed by attaching a non-conductive film 85 onto a metal surface 83, by a bolt 90. The ground terminal comprises: a terminal main body part 20 including a bolt hole 21 through which a shank 95 of the bolt 90 can be inserted; a mesh corner part 23 which is formed at an edge of the bolt hole 21 while protruding closer to the body 80 and meshed into the metal surface 83 by breaking the non-conductive film 85 with fastening of the bolt 90; and a seating part 31 including a flat seating surface 33 which is formed in the terminal main body part 20 while protruding to the same side as the meshing corner part 23 and receives a fastening force of the bolt 90 in contact with the body 80 in the state where the meshing corner part 23 is brought into contact with the metal surface 83.SELECTED DRAWING: Figure 7

Description

  The technology disclosed in this specification relates to a ground terminal.

In general, in a wire harness or the like of an automobile, body grounding is achieved by fixing a ground terminal crimped to the end of a grounding electric wire to a predetermined position of the body. A nut is fixed to the body of the automobile by welding in advance. In addition, the body includes the above-described nut, and a required portion is painted to prevent corrosion. If the ground terminal is bolted to the body with the paint film formed by painting sandwiched between the body and the electrical contact with the body becomes insufficient, or if the paint film sags, There is a possibility of rattling on the ground terminal.

  In order to solve such a problem, there is a method in which the metal film between the ground terminal and the metal surface of the body is fixed by peeling off the coating film between the ground terminal and the metal surface of the body. For example, in Japanese Patent Application Laid-Open No. 2001-229994 (Patent Document 1 below), the plate-like member formed with the bolt insertion hole of the ground terminal protrudes outward from the both ends of the plate-like member through the thin wall portion, and a protrusion is formed at the tip. A protruding member is provided. Then, when the bolt is screwed onto the nut, the protrusion of the protruding member bites into the metal surface while the protrusion of the protruding member peels off the paint film of the vehicle body panel, and the ground terminal and the metal part come into direct contact.

JP 2001-229994 A

  However, in the configuration of Japanese Patent Laid-Open No. 2001-229994 (the above-mentioned Patent Document 1), if the bolt is tightened too much during bolt fastening, the so-called edge of the protruding member is crushed by the fastening force, and the tip of the protruding member is on the metal surface. There is a possibility that the metal surface is not touched as intended.

  The ground terminal disclosed in the present specification is a ground terminal that is attached to a body in which a non-conductive film is deposited on a metal surface with a bolt, and has a bolt hole through which the shaft portion of the bolt can be inserted. A terminal main body portion, an edge portion of the bolt hole that protrudes toward the body side, and a biting corner portion that breaks through the non-conductive film and bites into the metal surface as the bolt is tightened, and the terminal main body portion. And a seat portion having a flat seat surface that protrudes on the same side as the biting corner portion and receives a fastening force of the bolt in contact with the body while the biting corner portion is in contact with the metal surface.

  According to such a configuration, when the terminal main body is tightened with a bolt, the biting corner formed at the edge of the bolt hole breaks through the non-conductive film and bites into the metal surface of the body. At this time, with the biting corner in contact with the metal surface, the flat seating surface of the seating part can contact the body and receive the tightening force of the bolt fastening. The corner portion can be prevented from slipping on the metal surface while being deformed, and the biting state of the biting corner portion can be maintained.

As an embodiment of the ground terminal disclosed in the present specification, the following configuration may be employed.
The seating portion may be provided in an arcuate region centered on the bolt hole.
According to such a structure, a seating part can receive the fastening force by a volt | bolt equally.

Moreover, the said seating part is good also as a structure currently formed in the continuous annular shape centering on the said bolt hole.
According to such a configuration, since the seating portion surrounds the outer periphery of the contact portion between the biting corner and the metal surface of the body, it is possible to prevent foreign matter or water from entering the contact portion between the biting corner and the body. Can be suppressed.

  According to the ground terminal disclosed in the present specification, since a part of the ground terminal surely breaks through the non-conductive film and bites into the metal surface of the body, the contact resistance is reduced.

The top view of the ground terminal concerning an embodiment Side view Bottom view Perspective view of the bottom side The perspective view which shows the state before bolting Sectional view showing the state before bolting Sectional view showing the bolted state

<Embodiment>
Embodiments will be described with reference to FIGS. 1 to 7.
The ground terminal 10 of the present embodiment is crimped to the terminal of the grounding electric wire W of the automobile wire harness, and is attached to the body 80 with a headed bolt 90 (an example of a “bolt”). The electric wire W is grounded. In the present embodiment, the vertical direction is based on FIGS. 2 and 6.

  As shown in FIGS. 5 to 7, the body 80 has a metal casing 81 whose surface is a metal surface 83 for ground connection. The metal surface 83 is coated to prevent corrosion and is covered with a coating film 85 (an example of a “non-conductive film”). Further, a nut 87 that can be screwed with the headed bolt 90 is welded and fixed to the lower side (back side) of the casing 81 of the body 80 so that the female screw hole 87A of the nut 87 can be exposed. An opening 89 is provided in the housing 81.

  As means for fixing the ground terminal 10 to the body 80, a headed bolt 90 is used as shown in FIGS. The headed bolt 90 has a hexagonal head 91, and a circular washer 93 whose diameter is larger than that of the head 91 is integrated. The headed bolt 90 has a shaft portion 95 on which a male screw that can be screwed into the female screw hole 87A of the nut 87 is formed.

  Next, the ground terminal 10 will be described with reference to FIGS. The ground terminal 10 is made of, for example, a metal such as copper, copper alloy, aluminum, aluminum alloy, etc., and the terminal main body portion 20 provided with the bolt holes 21 and the wire connecting portion to which the wire W for grounding the wire harness is connected. 15. The wire connection portion 15 is provided with an open barrel type wire barrel 17 and an insulation barrel 19 to which the wire W is crimped. The wire barrel 17 is caulked to the core wire end of the electric wire W, and the insulation barrel 19 formed behind the wire barrel 17 is caulked to the end of the insulating coating of the electric wire W.

  As shown in FIG. 1, the terminal body 20 has a substantially square plate shape with rounded corners, and a substantially circular bolt hole 21 is formed at the center thereof. The bolt hole 21 allows the shaft portion 95 of the headed bolt 90 to be inserted. As shown in FIG. 7, the inner diameter dimension of the bolt hole 21 is larger than the inner diameter dimension of the opening 89 of the housing 81. ing. As shown in FIGS. 3 and 6, the edge (peripheral edge) of the bolt hole 21 in the back surface of the terminal body 20 is in the direction (lower side) intersecting the plate surface of the terminal body 20. A biting corner portion 23 that protrudes and bites into the metal surface 83 is provided.

  The biting corner 23 is continuously formed over the entire circumference of the edge of the bolt hole 21, and is obliquely inwardly downward (in the present embodiment, at an angle of about 45 degrees from the plate surface of the terminal body 20). It protrudes. Since the biting corner portion 23 protrudes at such an angle, the edge 25 having a sharp shape at the corner of the biting corner portion 23 protrudes downward (to the body 80 side). The edge 25 is formed to have an angle of about 90 degrees and is perpendicular to the metal surface 83 of the housing 81. The biting corner portion 23 is formed by burring the edge portion of the bolt hole 21 downward. In addition, in order to process into such a shape, the shaping | molding which bends a shear surface should just be performed, and the burring process is the optimal as an example.

  A region around the bolt hole 21 of the terminal main body portion 20 is a fastening portion 30 that receives a force generated by tightening the headed bolt 90. In the present embodiment, the washer 93 is disposed between the fastening portion 30 of the terminal main body portion 20 of the ground terminal 10 and the head portion 91 of the headed bolt 90. The force is directly applied to a region that is in contact with the lower surface of the washer 93 so that the terminal body 20 is pushed downward. That is, the fastening portion 30 of the terminal main body portion 20 is a region that comes into contact with the washer 93, and is a region that receives an axial force due to tightening of the headed bolt 90. As shown in FIG. This is within the projection range of the washer 93 (a region surrounded by a two-dot chain line in FIG. 1).

  As shown in FIGS. 3 and 4, the fastening portion 30 of the terminal main body portion 20 is provided with a seating portion 31 that protrudes to the same side (downward) as the biting corner portion 23. The seat portion 31 has a continuous annular shape that is concentric with the biting corner portion 23, and has a flat seat surface 33 that is substantially parallel to the surface of the coating film 85 that contacts the coating film 85. The seating portion 31 is in contact with the body 80 by the flat seating surface 33, and when the seating portion 31 receives an axial force due to the tightening of the headed bolt 90, the seating portion 31 is crushed to receive the force on the entire flat seating surface 33. It has become difficult.

  As shown in FIG. 6, the edge 25 of the biting corner 23 projects downward from the lower surface of the terminal body 20 of the ground terminal 10. Since the protruding dimension L1 to the lower end portion of the edge 25 is larger than the thickness of the coating film 85, it can penetrate through the coating film 85 and bite into the metal surface 83. On the other hand, the seat portion 31 also protrudes below the lower surface of the terminal body portion 20 of the ground terminal 10. The protruding dimension L2 to the lower end of the flat seating surface 33 of the seating part 31 is smaller than the protruding dimension L1 of the edge 25. More specifically, the flat seat surface 33 is in contact with the coating film 85 in a state where the edge 25 is in contact with the metal surface 83. That is, the protrusion dimension L1 of the edge 25 is substantially equal to the film thickness of the coating film 85 or the amount of biting into the metal surface 83 of the edge 25 compared to the protrusion dimension L2 of the seating portion 31. It is slightly larger than the film thickness.

  Next, a procedure for attaching the ground terminal 10 will be described. As shown in FIGS. 5 and 6, the ground terminal 10 is placed on the coating film 85 of the body 80. At this time, the ground terminal 10 is arranged so that the center positions of the female screw hole 87A of the nut 87 and the bolt hole 21 are aligned. When the head bolt 90 is tightened by screwing the male screw of the shaft portion 95 of the head bolt 90 into the female screw hole 87 </ b> A, the lower surface of the washer 93 comes into contact with the fastening portion 30. When the head bolt 90 is further tightened in this state, the terminal main body portion 20 of the ground terminal 10 receives an axial force (fastening force) due to the tightening of the head bolt 90 and is pushed downward.

  As shown in FIG. 7, when the fastening portion 30 of the ground terminal 10 is pushed downward by receiving the axial force due to the tightening of the head bolt 90, the downward force is concentrated on the edge 25 portion. The edge 25 of the biting corner 23 bites into the coating film 85, and the edge 25 penetrates the coating film 85 and contacts the metal surface 83 of the housing 81. Then, with the edge 25 biting into the metal surface 83, the flat seat surface 33 of the seat portion 31 comes into contact with the coating film 85 so that the entire flat seat surface 33 receives an axial force due to tightening of the head bolt 90. become. For this reason, even if the headed bolt 90 is excessively tightened, the force is received by the seat portion 31, so that no excessive force is applied to the edge 25. Moreover, since the seating part 31 contacts the coating film 85 with the flat seat surface 33 without corners, the corners are not crushed and there is no possibility of sliding on the coating film 85.

  In this way, the edge 25 of the biting corner 23 penetrates the coating film 85 and bites into the metal surface 83 and is fixedly connected, so that a current can flow directly from the ground terminal 10 to the housing 81. In addition, since the edge 25 directly bites into the metal surface 83, even when the coating film 85 has a sag or the like, there is a portion that is fixed between the metals, so that the back to the ground terminal 10 is It is difficult for sticking to occur. And since the seat part 31 surrounds the outer periphery of the part where the edge 25 bites into the metal surface 83 and the edge 25 is not exposed to the outside by coming into contact with the coating film 85, the exposed part of the edge 25 and the metal surface 83 It is possible to prevent foreign matter from entering the water or water from entering.

  As described above, in this embodiment, when the terminal body 20 is tightened with the headed bolt 90, the biting corner 23 formed at the edge of the bolt hole 21 breaks through the coating film 85 and the metal surface 83 of the body 80. Bite into. At this time, since the flat seating surface 33 of the seating portion 31 is in contact with the body 80 in a state where the biting corner portion 23 is in contact with the metal surface 83, it is possible to receive a fastening force of bolt fastening. Even if it tightens too much, it can suppress that the biting corner | angular part 23 slips on the metal surface 83, deform | transforming, and the biting corner 23 can maintain the biting state.

  The seating portion 31 is provided in an arc-shaped region with the bolt hole 21 as the center. Therefore, the seating part 31 can receive the fastening force by the headed bolt 90 equally.

  The seat portion 31 is formed in a continuous annular shape with the bolt hole 21 as the center. Therefore, since the seating portion 31 surrounds the outer periphery of the contact portion between the biting corner portion 23 and the metal surface 83 of the body 80, foreign matter, water, or the like enters the contact portion between the biting corner portion 23 and the body 80. Can be suppressed.

<Other embodiments>
The technology disclosed in the present specification is not limited to the embodiment described with reference to the above description and drawings, and includes, for example, the following various aspects.
(1) In the above-described embodiment, the nut 87 is fixed to the body 80 by welding.

(2) In the above embodiment, the head bolt 90 is fastened, but a stud bolt is erected on the body 80 side, the ground terminal 10 is penetrated, and the stud bolt is fastened with a nut to fix the ground terminal 10 to the body 80. You may make it do.

(3) In the above embodiment, the coating film 85 is given as an example of a non-conductive film, but the non-conductive film may be an oxide film that is spontaneously formed on the surface of a metal plate made of aluminum, for example. Good. Further, the non-conductive film is not limited to the one having insulating properties, and any non-conductive film may be used as long as it has a conductivity lower than that of the metal surface 83 of the body 80.

(4) In the above embodiment, the headed bolt 90 and the washer 93 are integrated, but the washer may be separated from the bolt. Further, the ground terminal 10 may be fastened only with a bolt without using the washer 93.

(5) In the above embodiment, the seat portion 31 has a continuous annular shape, but may have a discontinuous shape. Moreover, it may be linear instead of arcuate.

(6) In the above embodiment, the flat seat surface 33 has a flat surface shape, but may have a curved surface shape. Further, it is sufficient that the biting corner portion 23 is less likely to be crushed.

DESCRIPTION OF SYMBOLS 10 ... Ground terminal 20 ... Terminal main-body part 21 ... Bolt hole 23 ... Biting-in corner | angular part 25 ... Edge 30 ... Fastening part 31 ... Seating part 33 ... Flat seat surface 80 ... Body 83 ... Metal surface 85 ... Paint film (non-conductive film)
87 ... Nut 87A ... Female thread hole 90 ... Bolt with head (bolt)
91 ... head 93 ... washer 95 ... shaft

Claims (3)

A grounding terminal attached with a bolt to a body in which a non-conductive film is deposited on a metal surface,
A terminal body portion having a bolt hole through which the shaft portion of the bolt can be inserted;
A biting corner portion that is formed to protrude toward the body side at the edge of the bolt hole, and breaks through the non-conductive film with the fastening of the bolt and bites into the metal surface,
A seating portion having a flat seat surface which is formed on the terminal main body portion so as to protrude on the same side as the biting corner portion and receives the fastening force of the bolt in contact with the body in a state where the biting corner portion is in contact with the metal surface. And a ground terminal.   The grounding terminal according to claim 1, wherein the seating portion is provided in an arc-shaped region centered on the bolt hole.   The ground terminal according to claim 2, wherein the seating portion is formed in a continuous annular shape centering on the bolt hole.

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