JP2013114911A - Socket terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a socket terminal capable of stably obtaining a required contact pressure while realizing a small size in a longitudinal direction.SOLUTION: Plural elastic contact pieces 25 are formed to extend from an annular terminal body 21 having an electric wire connection part 22 at a rear part in a cantilever manner, and therefore, a sleeve 23 in which a mating pin terminal 10 is inserted is formed and each elastic contact piece 25 is twisted and formed spirally. The sleeve 23 is tapered, and an inner face of each elastic contact piece 25 at that tapered portion is a contact section 28. A portion of each elastic contact piece 25 in front of a position of the contact section 28 is bent outward, and a leading tapered guide section 27 is formed at a tip of the sleeve 23.

Description

  The present invention relates to a socket terminal fitted and connected to a pin terminal.

  Conventionally, what was described in the following patent document 1 is known as an example of this kind of socket terminal. This is because three elastic contact pieces are formed in a cantilever shape with a predetermined interval in the circumferential direction from a ring-shaped terminal body having a wire connection portion connected to the end of the wire at the rear. A structure in which a sleeve is formed, and a pin terminal made of a mating round pin is inserted into the sleeve while expanding each elastic contact piece to receive a contact load, so that electrical connection between both terminals is taken. It is like that.

JP-A-10-116644

  In the socket terminal having the above structure, the contact load depends on the bending stress of the elastic contact piece, and as shown in the load-displacement (deflection) characteristic graph of FIG. In order to obtain a load, it is necessary to set a large spring constant as indicated by the characteristic line X. However, in the case where the spring constant of the elastic contact piece is large as described above, as shown in the figure, the load variation x in the displacement tolerance range t is large, and the required contact pressure cannot be obtained due to manufacturing errors. There is a fear.

On the other hand, if the elastic contact piece is formed with a small spring constant as shown by the characteristic line Y, the load variation y can be kept small even in the same tolerance range t, which is advantageous for obtaining a stable contact pressure. It becomes. However, if the spring constant is small, a large amount of displacement is required to generate the required load, and a corresponding length is required to design an elastic contact piece that satisfies this requirement. However, there is a limit in reducing the size in the length direction.
The present invention has been completed based on the above circumstances, and its purpose is to provide a socket terminal capable of stably obtaining a necessary contact pressure after realizing miniaturization in the length direction. There is to offer.

  In the socket terminal of the present invention, a sleeve into which a mating pin terminal is inserted is formed by extending a plurality of elastic contact pieces in a cantilever manner from a ring-shaped terminal body having a wire connecting portion at the rear. And each elastic contact piece is characterized in that it is configured to be twisted and formed in a spiral shape.

Since the elastic contact piece is twisted and formed in a spiral shape, the entire length of the sleeve is kept short while the elastic contact piece is lengthened. When the mating pin terminal is inserted into the sleeve of the socket terminal, each elastic contact piece is deformed so as to expand while being twisted back, and then deformed so as to simply expand from the middle. Torsion and bending stress act on the contact piece, and only bending stress acts on the elastic contact piece that is long from the middle. The load-displacement characteristic of the elastic contact piece has a large spring constant in the middle. Shows a non-linear characteristic with a small spring constant.
In other words, despite the fact that the overall length of the sleeve is kept small, a certain amount of required load can be obtained at the initial stage of pin terminal insertion, and the variation in load within the tolerance range can be kept small at the end of insertion. As a result, it is possible to stably obtain the necessary contact pressure while realizing miniaturization in the length direction.

The following configuration may also be used.
(1) The sleeve is narrowed down, and the inner surface of each elastic contact piece at the narrowed portion is a contact portion.
The contact portions of each elastic contact piece are arranged in a circular shape as a whole, and elastically contact over the entire outer periphery of the mating pin terminal. Compared to the case where each elastic contact piece is knocked out on the inner surface to provide a contact portion, all the contact portions are easily arranged in a regular circle, and the contact portion can be brought into contact with the entire circumference of the outer surface of the pin terminal. , Conductivity is improved.

(2) Since the portion of each elastic contact piece that is ahead of the position of the contact portion is bent outward, a guide portion having a tapered shape is formed at the tip of the sleeve.
When the mating pin terminal is inserted into the sleeve, it is smoothly centered and inserted by the guide portion.

(3) A base end portion connected to the terminal main body in each elastic contact piece is formed in a straight posture along the axis of the sleeve.
If the contact load between the socket terminal and the pin terminal is set large, the insertion resistance increases accordingly. Therefore, it is necessary to determine the contact load, that is, the spring constant of the elastic contact piece in consideration of the insertion resistance. Here, when changing the spring constant of the elastic contact piece, if the elastic contact piece is twisted and deformed over its entire length, it is difficult to adjust the spring constant due to complicated stress calculation and the like. .
On the other hand, in the present invention, since the straight part where only bending stress acts is provided at the base end part of the elastic contact piece, the adjustment of the spring constant of the elastic contact piece is compared by changing the length of the straight part, for example. Can be done easily.

(4) The core wire of the electric wire is connected to the electric wire connecting portion by brazing.
(5) The electric wire connecting portion is provided with a barrel that is crimped to the core wire of the electric wire.

  According to the socket terminal of the present invention, the necessary contact pressure can be stably obtained while realizing miniaturization in the length direction.

The top view of the socket terminal which concerns on Embodiment 1 of this invention Front view Side view Partially cutaway plan view showing the operation of inserting the pin terminal into the socket terminal Plan view of unfolded shape of socket terminal Side view of the pin terminal properly inserted into the socket terminal Graph showing the spring characteristics of socket terminals The top view of the socket terminal concerning Embodiment 2 Cross sectional view Top view of the developed shape Graph showing the spring characteristics of the conventional example

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
The socket terminal 20 according to the present embodiment is attached to one connector of a connector that connects power wires wired between a motor and an inverter device in a hybrid vehicle, for example, and is connected to the mating connector. The pin terminal 10 mounted on the mating connector is fitted and connected.

  As schematically shown in FIG. 4, the pin terminal 10 is made of a round metal bar such as copper or copper alloy, formed into a round pin shape as a whole through processes such as forging and cutting, and is tapered at the tip. The taper part 11 is formed. The pin terminal 10 is connected to the terminal of one of the power wires by caulking a closed barrel 12 (only a part of which is shown) provided at the rear end.

The socket terminal 20 is made of a metal plate such as copper or copper alloy, cut into a developed shape shown in FIG. 5 by press working, and further formed into a shape shown in FIGS. 1 to 4 by bending. The
The final shape of the socket terminal 20 is roughly formed by three elastic contact pieces 25 extending in a cantilever manner from a ring-shaped terminal body 21 provided with a wire connecting portion 22 at the rear thereof. A sleeve 23 into which 10 is inserted is formed.

  Specifically, in the developed shape, as shown in FIG. 5, the terminal body 21 is formed as a strip having a predetermined width that is elongated in a direction orthogonal to the axial direction of the socket terminal 20. A plate-like electric wire connecting portion 22 having a substantially square shape having a width half the length of the terminal main body 21 is continuously provided at the center in the length direction at the rear edge.

From the front edge of the terminal main body 21 having the above-described strip shape, three elastic contact pieces 25 having an elongated tongue shape having a slightly narrower width than the terminal main body 21 are spaced forward and directed forward. Protrusions are formed. More specifically, the three elastic contact pieces 25 are formed so as to protrude in an oblique posture in which the tip is swung to the left by a predetermined angle (for example, 35 degrees) in front view with respect to the axis of the socket terminal 20. About the space | interval of the elastic contact piece 25, about the half of the width | variety of the elastic contact piece 25 is taken.
In addition, a guide piece 26 is formed at the front end edge of each elastic contact piece 25 so as to project forward in the axial direction by a short length with the same width as the front end edge.

The socket terminal 20 is manufactured in the shape shown in FIGS. 1 to 4 as follows.
A terminal body 21 having a perfect circular shape is obtained by turning a strip-shaped terminal body 21 into a perfect circle from what has been cut into the developed shape shown in FIG. 5 and fixing both ends thereof by welding or the like. In addition, a wire connecting portion 22 having a semi-cylindrical shape with an upper surface opening is formed at the rear edge of the terminal body 21.

  At the same time, the three elastic contact pieces 25 are arranged in a circular shape in such a manner that the tip end side is bent obliquely so as to gradually face inward and is twisted by a predetermined amount. In other words, from the front edge of the ring-shaped terminal body 21, the three elastic contact pieces 25 twisted and deformed in a spiral shape are formed in a cantilever shape with a predetermined interval in the circumferential direction. As a whole, a sleeve 23 having a tapered cylindrical shape is formed.

In addition, the guide piece 26 provided at the tip of each elastic contact piece 25 is circularly arranged in a form that is similarly twisted and then outwardly opened and deformed, and forms a tapered shape with a first opening as a whole. 27 is formed.
Further, an arc-shaped contact portion 28 is formed by the base end portion of the guide piece 26 in each elastic contact piece 25, in other words, the inner surface of the most narrowed portion of the tip end of the elastic contact piece 25. These three contact portions 28 as a whole are arranged in a circular shape having a diameter φ2 smaller than the diameter φ1 of the counterpart pin terminal 10 by a predetermined dimension.

  The socket terminal 20 of the present embodiment has the shape as described above, and the end of the core wire of the covered wire constituting the power wire is fitted into the wire connecting portion 22 and brazed, so that the socket terminal 20 is attached to the end of the covered wire. Terminal 20 is connected. The socket terminal 20 is attached to the female connector of the pair of connectors. On the other hand, a pin terminal 10 connected to the end of the power cable is attached to the male connector.

Then, when the male and female connectors are fitted, the corresponding socket terminals 20 and pin terminals 10 mounted on the male and female connectors are fitted and connected. Specifically, as shown in FIG. 23, the mating pin terminal 10 is inserted from the front.
Specifically, the terminals 10 and 20 are aligned with each other by engaging the tapered portion 11 at the tip of the pin terminal 10 and the guide portion 27 at the tip of the sleeve 23 in the socket terminal 20, while the pin terminal 10 is aligned with the socket terminal 20. The sleeve 23 is inserted.

  When the intermediate portion of the taper portion 11 of the pin terminal 10 is further pushed from a state where it contacts the inner surface of the contact portion 28 of the sleeve 23, the distal end side of each elastic contact piece 25, that is, the distal end side of the sleeve 23 is gradually elastically opened and deformed. However, when the pin terminal 10 enters, passes through the tapered portion 11 and the outer periphery of the main body portion of the pin terminal 10 reaches the contact portion 28, the sleeve 23 opens to the maximum, and the open state is maintained as shown in FIG. As described above, when almost the entire length of the pin terminal 10 is inserted into the sleeve 23, the insertion of the pin terminal 10 is stopped. When the contact portion 28 is pressed against the outer periphery of the pin terminal 10 by the restoring elastic force of the sleeve 23 at that time, the corresponding terminals 10 and 20 are electrically connected to each other.

Here, the form when the pin terminal 10 is inserted into the sleeve 23 of the socket terminal 20 will be considered again. In terms of shape, since the three elastic contact pieces 25 constituting the sleeve 23 are twisted and formed in a spiral shape, the length of the elastic contact piece 25 itself is long, but the entire length of the sleeve 23 is taken. Is kept short.
When the mating pin terminal 10 is inserted into the sleeve 23 of the socket terminal 20, each elastic contact piece 25 is deformed so as to expand while returning torsion, and is simply deformed so as to expand from the middle, in other words. First, torsion and bending stress act on the elastic contact piece 25, and only bending stress acts on the elastic contact piece 25 that is long from the middle. The load-displacement characteristics of the elastic contact piece 25 are as follows. As shown by the characteristic line A in FIG. 7, the first region a1 shows a non-linear characteristic in which the spring constant is large and the subsequent region a2 has a small spring constant.
In the graph showing the load-displacement characteristics of FIG. 6, since both the twist and the bending act on the elastic contact piece 25 as described above, it cannot be expressed as a simple displacement. It is replaced by the approach stroke.

  That is, according to the socket terminal 20 of the present embodiment, a certain amount of necessary load can be obtained at the initial stage of insertion of the pin terminal 10 even though the entire length of the sleeve 23 is kept small. Thus, variation in the load in the tolerance range can be suppressed, and as a result, the required contact pressure can be stably obtained while realizing miniaturization in the length direction.

Further, since the contact portions 28 provided on the three elastic contact pieces 25 are arranged in a circular shape as a whole, they can be elastically contacted over the entire outer periphery of the pin terminal 10. For example, as compared with the case where the contact portions are provided by knocking on the inner surface of each elastic contact piece 25, all the contact portions 28 are easily arranged in a regular circle, and the contact portions 28 are in contact with the entire circumference of the outer surface of the pin terminal 10. And the conductivity is improved.
Further, since the guide portion 27 having a tapered shape is formed at the tip of the sleeve 23, when the mating pin terminal 10 is inserted into the sleeve 23, the center can be smoothly aligned.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.
In the socket terminal 20A of the second embodiment, the shape of the elastic contact piece 25A constituting the sleeve 23A is changed.
The elastic contact piece 25A of the second embodiment is a straight portion having the same width and a predetermined dimension along the axis of the sleeve 23A on the base end side connected to the terminal body 21 in the elastic contact piece 25 shown in the first embodiment. 30 has an extended shape. The straight portion 30 is not twisted when the sleeve 23A is formed, and is bent into an arc shape in the width direction with the same curvature as the terminal body 21.
Note that the wire connection portion 22A is formed shorter than the wire connection portion 22 of the first embodiment. Other structures are the same as those in the first embodiment, and portions having the same functions as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

In the socket terminal 20A of the second embodiment, as in the first embodiment, when the mating pin terminal 10 is inserted into the sleeve 23A of the socket terminal 20A, each elastic contact piece 25A is initially untwisted. It is deformed so that it expands, and is deformed so that it simply expands from the middle. Therefore, the spring constant is large at first and then the spring constant becomes small after that.
Therefore, although the entire length of the sleeve 23A is kept small, a certain amount of necessary load can be obtained at the initial stage of insertion of the pin terminal 10, and the variation in load in the tolerance range can be kept small at the final stage of insertion. As a result, the required contact pressure can be stably obtained while realizing downsizing in the length direction.

By the way, if the contact load between the socket terminal 20A and the pin terminal 10 is set large, the insertion resistance increases accordingly. Therefore, it is necessary to determine the contact load, that is, the spring constant of the elastic contact piece 25A in consideration of the insertion resistance. . Here, in changing the spring constant of the elastic contact piece 25A, if the elastic contact piece 25A is twisted and deformed over its entire length, it is difficult to adjust the spring constant due to complicated stress calculation and the like. There is.
On the other hand, in the second embodiment, since the straight portion 30 on which only bending stress acts is provided at the base end portion of the elastic contact piece 25A, for example, by changing the length of the straight contact portion 30, the elastic contact piece 25A The spring constant can be adjusted relatively easily.

<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 above embodiment, the case where the sleeve is narrowed down and the contact portion is formed by the inner surface of each elastic contact piece at the narrowed portion is exemplified. It may be formed by knocking to the side.
(2) In the above embodiment, the case where a guide portion having a tapered shape at the front end is formed at the tip of the sleeve is exemplified. However, the guide portion may be omitted, and such a guide portion is also technical in the present invention. Included in the range.

(3) The electric wire connection part provided in the rear part of the terminal main body may be in the form of a barrel that is crimped and crimped to the core wire of the electric wire.
(4) The number of elastic contact pieces constituting the sleeve is not limited to the three illustrated in the above embodiment, and may be set to two or four or more arbitrary plural.
(5) The present invention can be widely applied to all socket terminals that are fitted and connected to pin terminals, such as socket terminals applied to a vehicle charging connector.

DESCRIPTION OF SYMBOLS 10 ... Pin terminal 20, 20A ... Socket terminal 21 ... Terminal main body 22, 22A ... Electric wire connection part 23, 23A ... Sleeve 25, 25A ... Elastic contact piece 26 ... Guide piece 27 ... Guide part 28 ... Contact part 30 ... Straight part

Claims (6)

A plurality of elastic contact pieces are formed in a cantilever shape from a ring-shaped terminal body having a wire connection portion at the rear, thereby forming a sleeve into which a mating pin terminal is inserted, and each of the elastic contacts A socket terminal, wherein the piece is twisted and formed in a spiral shape. 2. The socket terminal according to claim 1, wherein the sleeve is narrowed to a taper, and an inner surface of each elastic contact piece at the narrowed portion is a contact portion. A portion of each elastic contact piece ahead of the position of the contact portion is bent outward, so that a guide portion having a tapered shape is formed at the tip of the sleeve. The socket terminal according to claim 2. The base end part connected with the said terminal main body in each said elastic contact piece is formed in the straight attitude | position along the axis line of the said sleeve, The Claim 1 thru | or 3 characterized by the above-mentioned. Socket terminal as described. The socket terminal according to any one of claims 1 to 4, wherein a core wire of the electric wire is connected to the electric wire connecting portion by brazing. The socket terminal according to any one of claims 1 to 4, wherein the electric wire connecting portion is provided with a barrel that is caulked and crimped to a core wire of the electric wire.

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