JP2015103282A - Ground terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure reliable contact of a ground terminal with the body.SOLUTION: A ground terminal 30 being mounted on a body 10, where a ground surface 13 of a housing 11 made of a conductive metal is coated with a non-conductive film 15, by means of a bolt 20 includes a terminal body 35 having a mounting hole 37 into which the bolt 20 can be inserted, a part of the rim of the mounting hole 37 is a protrusion 41 protruding to the ground surface 13 side while facing the mounting hole 37, the rim of the mounting hole 37 adjacent to the protrusion 41 is connected integrally with the protrusion 41 as a reinforcement portion 43 for reinforcing the protrusion 41, and when the bolt 20 is tightened, the protrusion 41 penetrates the non-conductive film 15 and bites into the ground surface 13.

Description

  The present invention relates to a ground terminal.

  Generally, in an automobile wire harness or the like, a ground terminal is crimped to a terminal of an electric wire for grounding, and the ground terminal is attached to a predetermined position of the body to take the ground. Usually, the above-mentioned metal body together with a nut fixed in advance by welding to the body of an automobile is painted to prevent corrosion. When the ground terminal is bolted to the body through such a coating film, when the coating film sags, the ground terminal rattles. Therefore, there is a method of peeling off the coating film between the ground terminal and the metal surface of the body, and fixing the metal between the ground terminal and the metal surface of the body.

  For example, in Patent Document 1, a plurality of scraped portions are provided along the edge of the mounting hole of the ground terminal, and the scraped portions are peeled off so as to scrape the coating film on the upper end surface of the nut. A configuration in which the end face is exposed is described. As a result, the metal of the ground terminal and the nut comes into contact with each other.

JP 10-125374 A

  However, in the configuration of Patent Document 1, in the step of peeling the coating film (step of attaching the ground terminal), depending on the state of the coating film, the stripped portion is removed along with the bolt tightening before the metal surface is exposed by peeling off the coating film. There was a possibility that the coating film would not be removed as intended because it was flat. For this reason, the ground terminal may not be reliably contacted with the metal surface.

  The present invention has been completed based on the above situation, and an object of the present invention is to enable a ground terminal to reliably contact a metal surface of a body.

  The ground terminal of the present invention is a ground terminal that is attached to a body in which a non-conductive film is attached to the ground surface of a casing made of a conductive metal, and is an attachment hole through which the bolt can be inserted. A part of the periphery of the mounting hole is a protruding part that faces the mounting hole and protrudes toward the grounding surface, and the mounting hole adjacent to the protruding part The peripheral edge of each of the first and second protrusions is a reinforcing part that reinforces the protruding part by being integrally connected to the protruding part, and the protruding part penetrates through the non-conductive film as the bolt is tightened to the grounding surface. Bite.

  According to such a structure, since the protrusion part protrudes in the grounding surface side in the state connected integrally with the reinforcement part, even if the force by tightening of a volt | bolt is applied, it does not become a flat state. Therefore, when a force due to fastening is applied, the non-conductive film can be penetrated and bite into the ground plane. In this way, the protruding portion bites into the ground surface, so that the metals can be fixed without being affected by the sag of the non-conductive film, and the bolt fastening is not loosened. In addition, the ground plane and the ground terminal can be directly connected through the protruding portion.

The embodiment of the ground terminal of the present invention may have the following configuration.
A plurality of the projecting portions may be formed at equal angular intervals with the mounting hole as a center.
In such a configuration, since the protrusions bite into the ground plane at a plurality of locations, the fixing and conduction between the ground terminal and the ground plane are stabilized.

Moreover, it is good also as a structure by which the internal-diameter dimension of the said attachment hole defined by the inner edge of the said reinforcement part is made slightly larger than the outer-diameter dimension of the axial part of the said bolt which penetrates the said attachment hole.
In such a configuration, since the inner diameter of the mounting hole determined by the inner edge of the reinforcing portion is slightly larger than the outer diameter of the bolt shaft, the size of the portion where the protrusion is formed is affected. The bolt can be tightened in the positioning state.

  According to the present invention, the ground terminal can be reliably brought into contact with the metal surface of the body.

The top view of the ground terminal which concerns on one Embodiment of this invention Side view Plan view showing the manufacturing process of the ground terminal A plan view showing a state in which a head bolt is fastened. Sectional view showing the state before bolting Sectional view showing the bolted state

<Embodiment>
An embodiment of the present invention will be described with reference to FIGS.
The ground terminal 30 in the present embodiment is attached to the body 10 with the head bolts 20. Hereinafter, in each constituent member, the vertical direction is based on FIGS. 2 and 5. Moreover, about the front-back direction of the ground terminal 30, let the left side of FIG. 2 be the front, and let the right side (electric wire W side) of FIG. 2 be the back.

  The body 10 has a metallic casing 11 with good conductivity. As shown in FIGS. 5 and 6, the surface of the casing 11 is a ground plane 13 for ground connection. The ground surface 13 is coated to prevent corrosion and is covered with a coating film 15. In addition, a female screw hole 17 that can be screwed with the headed bolt 20 is formed in the housing 11 of the body 10 so as to open to the ground surface 13.

  As means for fixing the ground terminal 30 to the body 10, a headed bolt 20 is used as shown in FIGS. The headed bolt 20 has a hexagonal head 21, and a circular washer 23 having a diameter larger than that of the head 21 is integrated. The headed bolt 20 has a shaft portion 25 on which a male screw that can be screwed into the female screw hole 17 is formed.

  Next, the ground terminal 30 will be described with reference to FIGS. The ground terminal 30 is provided with an open barrel type wire barrel 31 and an insulation barrel 33 to which the wire W of the wire harness is crimped. The wire barrel 31 is caulked to the core wire end of the electric wire W, and the insulation barrel 33 formed behind the wire barrel 31 is caulked to the end of the insulating coating of the electric wire W. Further, the wire barrel 31 is formed with a serration 31A (see FIG. 3) for improving the pressure bonding with the core wire in a groove shape.

  Further, the ground terminal 30 is integrally provided with a terminal main body 35 that is connected to the front of the wire barrel 31 and is fastened to the body 10 by the headed bolt 20. The terminal main body 35 has a substantially circular plate shape, and a circular bolt hole 37 concentric with the terminal main body 35 is formed at the center thereof. The bolt hole 37 can be penetrated by the shaft portion 25 of the headed bolt 20. And the surface which is distribute | arranged around the bolt hole 37 and the washer 23 contact | abuts is made into the fastening surface 39 with the headed bolt 20. As shown in FIG.

  A projecting portion 41 that faces the bolt hole 37 and projects downward (on the grounding surface 13 side) is formed on the periphery of the bolt hole 37 in the fastening surface 39. Eight protrusions 41 are arranged at equiangular intervals with the bolt hole 37 as the center. The inner edge of the projecting portion 41 is notched outward in the radial direction of the bolt hole 37, and a part of the periphery of the bolt hole 37 is sheared parallel to the radial direction of the bolt hole 37 at the notched position. It is considered to be a piece. And the protrusion 41 is formed because the sheared piece is extended and flange-formed toward the lower side and plastically deformed. Thus, by performing stretch flange molding, the protrusion 41 is less likely to be flat due to the fastening force when the headed bolt 20 is tightened. Here, stretch flange molding refers to a molding method that stretches when the shear surface is bent, and examples thereof include burring.

  Further, as shown in FIGS. 2 and 6, the protruding portion 41 protrudes below the lower surface of the terminal main body portion 35 of the ground terminal 30 on the bolt hole 37 side (tip portion). Since this protrusion dimension L1 is larger than the film thickness of the coating film 15, it can penetrate through the coating film 15 and bite into the ground surface 13. In addition, the front-end | tip part of the protrusion part 41 protrudes in the acute angle toward the lower side, and has penetrated the coating film 15 easily.

  As shown in FIG. 1, the periphery of the bolt hole 37 adjacent to the projecting portion 41 is formed so as to be integrally connected to the projecting portion 41 by contacting the projecting portion 41, and the projecting portion 41 is reinforced. The reinforcing portion 43 is provided. The reinforcing portion 43 has a substantially fan shape, is flat with the terminal main body portion 35, and is a remaining portion where the protruding portion 41 is sheared from the peripheral edge portion of the bolt hole 37. When the reinforcing portion 43 abuts on the protruding portion 41 in the circumferential direction, the protruding portion 41 can be prevented from returning to a flat state by a frictional force.

  The inner diameter dimension of the bolt hole 37 determined by the inner edge of the reinforcing portion 43 is slightly larger than the outer diameter dimension of the shaft portion 25 through which the bolt hole 37 is inserted. That is, the gap between the bolt hole 37 and the shaft hole 25 is large enough not to interfere when the shaft portion 25 is inserted, but the bolt hole 37 slightly contacts the thread of the shaft portion 25 when tightening the bolt. The dimensions are small enough to be positioned. Further, the total dimension of the inner edge portion of the reinforcing portion 43 is longer at the peripheral edge of the bolt hole 37 than the total dimension of the inner edge portion of the protruding portion 41. As a result, regardless of the position of the inner edge of the projecting portion 41, the inner edge of the reinforcing portion 43 comes into contact with the thread of the male screw of the shaft portion 25, whereby the headed bolt 20 is tightened. The center position of the (shaft portion 25) and the bolt hole 37 is kept substantially the same.

  Next, a method for manufacturing the ground terminal 30 of the present embodiment will be described with reference to FIG. In FIG. 3, the left side is an initial process of manufacturing the ground terminal 30, and a press working line that approaches the finished product as it goes to the right side. The ground terminal 30 is subjected to cutting, bending, and the like in sequence while the hoop material is fed through the press processing line, so that the ground terminal 30 having a predetermined shape is formed. Here, the hoop material is a metal plate such as a copper alloy having excellent conductivity. First, in the first step, the serration 31A of the wire barrel 31 is formed by knocking out the ground terminal 30. Then, the bolt hole 37 is punched out together with the notch of the protruding portion 41. Then, the protruding portion 41 is sheared and stretched. Then, the outer shape of the ground terminal 30 is punched out. Finally, the wire barrel 31 and the like are bent to form the ground terminal 30. The wire W is crimped and connected to the ground terminal 30 formed in this way.

  Then, the ground terminal 30 to which the electric wire W is connected is connected to the body 10 as shown in FIGS. Specifically, as shown in FIG. 5, the ground terminal 30 is disposed on the coating film 15 of the body 10. At this time, the ground terminal 30 is arranged so that the center positions of the female screw hole 17 and the bolt hole 37 are aligned. And the center of the axial part 25 of the headed bolt 20 is aligned so that it may align with the center of the bolt hole 37 grade | etc.,. Then, the headed bolt 20 is tightened so that the male screw of the shaft portion 25 is screwed into the female screw hole 17. Then, the lower surface of the washer 23 comes into contact with the fastening surface 39. When the head bolt 20 is further tightened while rotating in this state, the fastening surface 39 is pushed by the washer 23, so that the protrusion 41 penetrates the coating film 15 as shown in FIG. The ground terminal 30 is fixedly connected to the body 10 by the headed bolt 20.

  At this time, since the projecting portion 41 is stretched flange-molded, it hardly causes plastic deformation to return to flat, but even if a force to return to flat is applied, the reinforcement adjacent to the projecting portion 41 is used. Since it abuts on the portion 43, there is almost no possibility of flattening. It is also possible to prevent the ground terminal 30 from being dragged and rotated by the rotation of the headed bolt 20 by the protrusion 41 biting into the body 10. And since the protrusion dimension L1 of the protrusion part 41 is larger than the film thickness of the coating film 15, it is possible for the protrusion part 41 to bite into the connection surface 13 reliably, and to connect the ground terminal 30 to the body 10 in a conductive manner. It has become.

  In this way, the projecting portion 41 penetrates the coating film 15 and bites into the ground surface 13 and is fixedly connected, so that a current can be directly passed from the ground terminal 30 to the housing 11. Therefore, since it is possible to pass a current other than the connection by screwing the male screw and the female screw hole 17 of the shaft portion 25, the current connection of the ground terminal 30 is stabilized. In addition, since the protruding portion 41 directly bites into the grounding surface 13 that is a metal surface, even if a sag or the like appears on the coating film 15, there is a portion that is fixed with metal, so that the ground terminal It becomes difficult for rattling to 30 to occur. Further, when the fastening surface 39 of the ground terminal 30 comes into contact with the washer 23 and a force is applied to the terminal main body 35, the projecting portion 41 gradually starts to bite into the body 10. It is difficult to rotate.

  As described above, according to the present embodiment, since the protruding portion 41 protrudes toward the grounding surface 13 in contact with the reinforcing portion 43, even if a force due to tightening of the headed bolt 20 is applied, the protruding portion 41 is in a flat state. Never become. For this reason, when a force is applied by fastening, the coating film 15 can be penetrated and bite into the ground surface 13. Thus, the protrusion 41 bites into the grounding surface 13 so that the metals can be fixed without being affected by the sag of the coating film 15 and the bolt fastening is not loosened. In addition, the ground plane 13 and the ground terminal 30 can be directly connected via the protruding portion 41.

Further, eight protrusions 41 are formed at equiangular intervals with the bolt hole 37 as the center.
In such a configuration, since the protruding portions 41 bite into the ground plane 13 at eight locations, the fixing and conduction between the ground terminal 30 and the ground plane 13 are stabilized.

Further, the inner diameter dimension of the bolt hole 37 determined by the inner edge of the reinforcing portion 43 is slightly larger than the outer diameter dimension of the shaft portion 25 of the headed bolt 20 that passes through the bolt hole 37.
In such a configuration, since the inner diameter of the bolt hole 37 determined by the inner edge of the reinforcing portion 43 is slightly larger than the outer diameter of the shaft portion 25 of the headed bolt 20, the protruding portion 41 is formed. The headed bolt 20 can be tightened in the positioning state regardless of the inner diameter dimension of the position where it is located.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the said embodiment, although the earth terminal 30 was single, you may use the structure of this invention for the earth terminal distribute | arranged to the uppermost part of what bolts together several earth terminals in combination.
(2) In the above embodiment, the shape of the terminal main body portion 35 of the ground terminal 30 is circular, but other shapes such as a substantially square shape may be used.

(3) In the above embodiment, the example in which the protruding portions 41 are eight is given, but other numbers may be used.
(4) In the above embodiment, the protrusions 41 are arranged at equiangular intervals, but they may be uneven.

(5) In the said embodiment, although the protrusion part 41 was sheared in parallel, the both ends to be sheared may be other than parallel.
(6) In the above embodiment, the protruding portion 41 is stretched and flange-formed after shearing, but may be formed on the peripheral portion of the bolt hole 37 by hammering or the like.

(7) In the above embodiment, the female screw hole 17 is formed in the body 10, but a nut may be welded to the lower side of the grounding surface 13 of the body 10 in advance.
(8) In the above embodiment, the headed bolt 20 is tightened, but a stud bolt may be erected on the body 10 side and tightened with a nut.

(9) In the above embodiment, the headed bolt 20 has the washer 23, but the washer may be a separate body or may not be used.
(10) In the above embodiment, the electrical connection is also provided between the shaft portion 25 and the female screw hole 17, but the electrical connection between the two may not be required.
(11) In the above embodiment, the non-conductive film is the coating film 15, but an oxide film or the like formed on the surface of an aluminum casing may be used.

DESCRIPTION OF SYMBOLS 10 ... Body 11 ... Housing 13 ... Grounding surface 15 ... Paint film (non-conductive film)
20 ... Head bolt (bolt)
30 ... Earth terminal 35 ... Terminal body 37 ... Bolt hole (mounting hole)
39 ... Fastening surface 41 ... Projection part 43 ... Reinforcement part

Claims (3)

A ground terminal attached with a bolt to a body in which a non-conductive film is attached to a ground surface of a casing made of conductive metal,
A terminal body having a mounting hole through which the bolt can be inserted;
A part of the periphery of the mounting hole is a protruding part that faces the mounting hole and protrudes toward the grounding surface,
The peripheral edge of the mounting hole adjacent to the protruding portion is a reinforcing portion that reinforces the protruding portion by being integrally connected to the protruding portion,
The projecting portion is a ground terminal that penetrates the non-conductive film and bites into the ground surface when the bolt is tightened.   The ground terminal according to claim 1, wherein a plurality of the protruding portions are formed at equiangular intervals with the mounting hole as a center.   3. The ground according to claim 1, wherein an inner diameter dimension of the mounting hole determined by an inner edge of the reinforcing portion is slightly larger than an outer diameter dimension of a shaft portion of the bolt that passes through the mounting hole. Terminal.

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