JP2015210863A - Contact connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact connection structure capable of reducing contact resistance without upsizing a terminal and complexing the terminal as much as possible.SOLUTION: A contact connection structure comprises first contact parts 2a and 3 in which an indent part 4 is installed in a protruding manner and a second contact part 11. In a terminal insertion process, the second contact parts 11 of the first contact parts 2a and 3 slide on a contact surface of the second contact part 11. In a terminal insertion completion position, an outer peripheral surface of the indent part 4 comes into contact with the second contact part 11. A tin plating layers 11b and 11c are formed on an external surface of the second contact part 11. A thing plating 11c having higher height than other locations is formed in the region corresponding to the terminal insertion completion position of the indent part 4.

Description

  The present invention relates to a contact connection structure that performs electrical connection between a first terminal and a second terminal.

  5 and 6 show a female terminal and a male terminal to which a conventional contact connection structure is applied (see Patent Document 1 as a similar technique). As shown in FIGS. 5 and 6, the female terminal 51 includes a rectangular box portion 52 and an elastic deflecting portion 52 provided integrally with the box portion 52 and disposed in the box portion 52. The elastic bending portion 53 is provided with an indent portion 54 that protrudes toward the bottom surface side. The indented portion 54 has a substantially spherical outer peripheral surface, and the center vertex is located at the lowest position. The female terminal 51 is tin-plated from the viewpoints of improving connection reliability in a high temperature environment and improving corrosion resistance in a corrosive environment. Therefore, as shown in FIG. 7, a tin plating layer 53b is formed on the outer surface of the base layer 53a of the copper alloy material in the elastic bending portion 53.

  As shown in FIGS. 5 and 6, the male terminal 60 has a flat tab portion 61. The male terminal 60 is tin-plated from the viewpoints of improving connection reliability in a high temperature environment and improving corrosion resistance in a corrosive environment. Therefore, as shown in FIG. 8, the tab portion 61 has a tin-plated layer 61b formed on the outer surface of the copper alloy base material layer 61a.

  In the above configuration, when the tab portion 61 of the male terminal 60 is inserted into the box portion 52 of the female terminal 51 in the position of FIG. 5, the elastic bending portion 53 is deformed and the insertion of the tab portion 61 is allowed. In the insertion process of the tab portion 61, the indent portion 54 of the elastic bending portion 53 slides on the contact surface of the tab portion 61, and at the terminal insertion completion position, as shown in FIGS. 6 and 9, the indentation of the elastic bending portion 53 is performed. The surface of the part 54 and the tab part 61 contacts.

  In this conventional example, the indented portion 54 of the female terminal 51 and the contact surface of the tab portion 61 of the male terminal 60 are in electrical contact with each other using the bending return force of the elastic bending portion 53 as a contact load.

  By the way, in the above-described insertion process of the tab portion 61, tin is a soft metal, so that the indent portion 54 is slid in a state of biting into the tin plating layer 61 b of the tab portion 61. Therefore, as shown in FIG. 10, the contact surface E2 between the indent portion 54 and the tab portion 61 has a semicircular shape when viewed from above.

JP 2007-280825 A

  However, in the conventional structure, the indent portion 54 of the female terminal 51 has a substantially spherical shape, and contacts the tab portion 61 of the male terminal 60 at the apex portion. Therefore, as shown in FIG. 10, since the outer diameter of this single contact surface becomes the apparent contact surface E2 (diameter: D2), the apparent contact surface E2 (hatched for clarity in FIG. 10) Is small.

  The apparent contact surface E2 is not actually in contact with the entire region because the entire region does not actually contact due to the influence of surface roughness or the like, but the surface that actually contacts within the apparent contact surface E2. (True contact surface) is responsible for electrical energization. However, if the apparent contact surface diameter D2 is small, the true contact surface is also small, so that the contact resistance is large.

  Here, in order to reduce the contact resistance by increasing the apparent contact surface, the bending return force (spring pressure) of the elastic bending portion 53 may be increased, or the contact portion (indent portion 54) may be enlarged. Though conceivable, the terminals 51 and 60 become larger or complicated.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a contact connection structure capable of reducing contact resistance without increasing the size of a terminal or making it as complex as possible.

  The present invention includes a first contact portion having a projecting indent portion and a second contact portion, and the indent portion of the first contact portion is on a contact surface of the second contact portion in a terminal insertion process. And the outer peripheral surface of the indent portion is in contact with the second contact portion at the terminal insertion completion position, and a plating layer is formed on the outer surface of the second contact portion. The contact connection structure is characterized in that a plating layer is formed higher in the region corresponding to the terminal insertion completion position of the indent portion than in other portions.

  The plating layer includes a tin plating layer.

  According to the present invention, the indented portion of the first contact portion is in contact with the second contact portion in a state where the indented position of the first contact portion is deeply recessed into the plating layer than in the conventional case. The apparent contact surface becomes larger. Since the apparent contact surface becomes larger, the total area of the true contact in it becomes larger. As described above, the contact resistance can be reduced without increasing the size of the terminal or making it as complex as possible.

It is sectional drawing of the female terminal and male terminal which show one Embodiment of this invention before a terminal connection. 1 shows an embodiment of the present invention, (a) is a cross-sectional view of a female terminal and a male terminal in a terminal connection state, (b) is a cross-sectional view of a main part of a contact connection location, (c) an apparent contact surface and a contact surface diameter. FIG. 1 shows an embodiment of the present invention, (a) is a cross-sectional view of the main part of the contact portion of the female terminal, (b) is a view taken in the direction of arrow A in (a). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention, where (a) is a plan view of a main part of a contact part of a male terminal, and (b) is a cross-sectional view of a main part of the contact part of the male terminal. It is a sectional view of a female terminal and a male terminal before showing a conventional example and connecting a terminal. It is a sectional view of a female terminal and a male terminal in a terminal connected state, showing a conventional example. A prior art example is shown, (a) is a principal part side view of the contact part of a female terminal, (b) is a B arrow directional view of (a). A prior art example is shown, (a) is a principal part top view of the contact part of a male terminal, (b) is principal part sectional drawing of the contact part of a male terminal. It is a principal part sectional drawing of a contact connection location, showing a conventional example. It is a figure which shows the apparent contact surface and contact surface diameter of a prior art example.

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

  1 to 4 show an embodiment of the present invention. The contact connection structure according to the present invention is applied between the female terminal as the first terminal and the male terminal as the second terminal. This will be described below.

  The female terminal 1 is disposed in a terminal accommodating chamber in a female connector housing (not shown). The female terminal 1 is formed by bending a conductive metal (for example, copper alloy) punched into a predetermined shape. The female terminal 1 includes a rectangular box part 2 having an opening in the front where the male terminal 10 is inserted, and an elastic bending part 3 that extends from the upper surface part of the box part 2 and is disposed in the box part 2. Have. The elastic bending portion 3 is provided with an indent portion 4 protruding toward the bottom surface side. The indented portion 4 has a substantially spherical outer peripheral surface, and the center vertex is located at the lowest position. The indent portion 4 can be shifted upward by the bending deformation of the bending deformation portion 3.

  The female terminal 1 is tin-plated from the viewpoints of improving connection reliability in a high temperature environment and improving corrosion resistance in a corrosive environment. Therefore, as shown in FIGS. 3A and 3B, the elastic bending portion 3 has a tin plating layer 3b formed on the outer surface of the base material layer 3a of the copper alloy material. In the female terminal 1, the elastic deflection portion 3 and the bottom surface portion 2 a of the box portion 2 form a first contact portion.

  The male terminal 10 is disposed in a terminal accommodating chamber in a male connector housing (not shown). The male terminal 10 is formed by bending a conductive metal (for example, copper alloy) punched into a predetermined shape. The male terminal 10 has a flat tab portion 11. The male terminal 10 is tin-plated from the viewpoints of improving connection reliability in a high temperature environment and improving corrosion resistance in a corrosive environment. Therefore, as shown in FIGS. 4A and 4B, the tab portion 11 has a tin plating layer 11b formed on the outer surface of the base material layer 11a of the copper alloy material. A tin plating layer 11 c is further formed on the tin plating layer 11 b and in a region corresponding to the terminal insertion completion position of the indent portion 4. That is, the region corresponding to the terminal insertion completion position of the indented portion 4 of the tab portion 11 is plated higher than the other portions by the height h of the tin plating layer 11c. The one-step higher tin plating layer 11c can be formed by stripe plating, thermal spraying, or a clad material. As for the male terminal 10, the tab part 11 forms the 2nd contact part.

  In the above configuration, when the female connector housing (not shown) and the male connector housing (not shown) are mated, the tab portion 11 of the male terminal 10 is connected to the box portion 2 of the female terminal 1 in the mating process. Inserted. Then, first, the tip of the tab portion 11 comes into contact with the elastic bending portion 3, and when the insertion further proceeds from this contact portion, the elastic bending portion 3 is bent and deformed, and insertion of the tab portion 11 is allowed. In the insertion process (terminal insertion process) of the tab part 11, the indent part 4 of the elastic bending part 3 slides on the contact surface of the tab part 11. At the terminal insertion completion position (connector mating completion position), as shown in FIG. 2A, the indented portion 4 of the elastic bending portion 3 is the surface of the tab portion 11 with the bending return force of the elastic bending portion 3 as a contact load. To touch.

  In the insertion process (terminal insertion process) of the tab portion 11 described above, since tin is a soft metal, the indent portion 4 slides while biting into the tin plating layer 11b of the tab portion 11. Then, at the position before the insertion completion position, the bumper hits the step of the tin plating layer 11c, but slides while sinking into the stepped tin plating layer 11c. At the terminal insertion completion position, the insertion front side of the outer peripheral surface of the indent portion 4 stops in a state where it is recessed into the tin plating layer 11b. That is, at the terminal insertion completion position, the indent portion 4 is deeply recessed by the tin plating layers 11b and 11c.

  In this contact connection structure, a tin plating layer 11b is formed on the outer surface of the tab portion 11, and a plating layer 11c is formed higher in the region corresponding to the terminal insertion completion position of the indent portion 4 than in other portions. Has been. Therefore, the indented portion 4 is located at the terminal insertion completion position and is in a state of being deeply recessed into the tin plating layer 11c as compared with the prior art. Therefore, as shown in FIG. 4 contacts the contact surface of the tab portion 11 with a large semicircular contact surface E1, and the apparent contact surface E1 (apparent contact surface diameter: D1) becomes larger than that of the conventional example. Since the apparent contact surface E1 is increased, the total area of the true contact surface is also increased compared to the conventional case. The apparent contact surface E1 is hatched for clarity in FIG. As described above, the contact resistance can be reduced without increasing the size of the female terminal 1 and the male terminal 10 or complicating them as much as possible.

  Next, it will be described that the contact resistance is reduced by Holm's contact theory. According to Holm's theoretical contact formula, contact resistance R is: D: apparent contact surface diameter (diameter), ρ: resistivity of contact material, a: radius of true contact surface (spot), n: true contact surface If it is a number, it is calculated by R = (ρ / D) + (ρ / 2na). In the present invention, since the apparent contact surface diameter D is larger than in the prior art, the contact resistance is reduced.

  In the tab portion 11, in the region corresponding to the terminal insertion completion position of the indent portion 4, it is only necessary to form the plating layer 11 c higher than other portions, so that a significant change in the manufacturing method is unnecessary.

  In this embodiment, the plating layers are tin plating layers 4b and 4c. Therefore, the cost is low. The material of the plating layer 4b may be a conductive material that is as soft as tin (indium (In), aluminum (AL), solder (SnAgCu system), or the like.

  In this embodiment, the outer peripheral surface of the indent portion 4 has a substantially spherical shape, but the shape of the outer peripheral surface is not limited. It may be a curved surface shape having an apex at the highest position and gradually lowering with a smooth curved surface toward the outer periphery, an elliptical curved surface shape, a conical shape, or a pyramid shape.

1 Female terminal (1st terminal)
2a Bottom part (first contact part)
3 Elastic flexure (first contact)
4 Indented portion 4b Tin plating layer 10 Male terminal (second terminal)
11 Tab part (second contact part)
11b Tin plating layer

Claims (2)

In the terminal insertion process, the indented portion of the first contact portion slides on the contact surface of the second contact portion. In the terminal insertion completion position, a contact connection structure in which an outer peripheral surface of the indent portion contacts the second contact portion,
A plating layer is formed on the outer surface of the second contact portion, and a plating layer is formed higher than other portions in a region corresponding to the terminal insertion completion position of the indent portion. Contact connection structure. The contact connection structure according to claim 1,
The contact connection structure, wherein the plating layer is a tin plating layer.

Images