JP2016024875A - Female terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a female terminal which allows for enhancement of contact reliability, by positioning the mutual axes when the male and female axes of a round pin terminal come into contact, and enhancing the contact load of the male terminal onto the round pin easily.SOLUTION: On the wall 2a of a cylindrical electric contact part 2 for achieving electrical energization by inserting the round pin 31 of a male terminal 30, a first elastic contact piece 8 formed arcuately to wind toward the central axis O so as to cover the axial direction of the round pin 31, and a second elastic contact piece 11 formed arcuately to wind toward the central axis so as to cover the axial direction of the round pin 31 are provided at positions facing the first elastic contact piece 8. The male terminal 30 is held while being pressed on two faces, by means of the first elastic contact piece 8 and second elastic contact piece 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a connection terminal for inserting a male terminal round pin to achieve electrical continuity, and more particularly to a female terminal capable of improving a contact load with a male terminal when a male terminal round pin is inserted.

  A conventional female terminal that achieves electrical continuity with a male terminal when a male terminal round pin is inserted has a configuration as shown in Patent Document 1. That is, as shown in FIG. 12, the female terminal shown in Patent Document 1 is made of a metal plate such as copper or copper alloy, cut into a developed shape by press working, and further bent to form an electric wire. From the front edge of the ring-shaped terminal body 21 provided with the connecting portion 22 at the rear, three elastic contact pieces 25 having a narrow tongue shape with a slightly narrower width than the terminal body 21 extend in a cantilevered manner. Thus, the sleeve 23 into which the round pin 10 of the mating male terminal is inserted is formed.

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 and twisted. It is formed in a spiral shape.
The sleeve 23 is tapered so that the inner surface of each elastic contact piece 25 at the narrowed portion serves as a contact portion 28, and the portion of each elastic contact piece 25 beyond the position of the contact portion 28 is outward. By being bent, a guide portion 27 having a tapered shape with a first opening is formed at the tip of the sleeve 23.

  When the male terminal round pin 10 is fitted and connected to the conventional female terminal 20 configured as described above, the mating male terminal round pin 10 is inserted into the sleeve 23 of the female terminal 20 from the front. When the midway of the taper portion 11 of the round pin 10 of the male terminal is further pushed from the 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 gradually becomes elastic. When the male terminal round pin 10 enters while being deformed to open and passes through the taper part 11 and the outer periphery of the main body part of the male terminal round pin 10 reaches the contact part 28, the sleeve 23 opens to the maximum, and the open state When the substantially entire length of the male terminal round pin 10 is inserted into the sleeve 23, the insertion of the male terminal round pin 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.

The female terminal 20 is formed in a spiral shape by twisting three elastic contact pieces 25 constituting the sleeve 23. When the mating male terminal round pin 10 is inserted into the sleeve 23 of the female terminal 20, each elastic contact piece 25 is deformed so as to expand while being unwound, and becomes a long elastic contact piece 25 from the middle. Only bending stress acts on it.
Thus, the contact between the conventional female terminal 20 and the round pin 10 of the male terminal inserted from the proximal end portion of the guide piece 26 in each elastic contact piece 25 of the terminal body 21 constitutes the sleeve 23 of the female terminal 20. This is done by three elastic contact pieces 25.

JP 2013-114911 A

As described above, the female terminal disclosed in Patent Document 1 is such that when the contact portion 28 is pressed against the outer periphery of the male terminal round pin 10 by the restoring elastic force of the sleeve 23, the corresponding male terminal round pin 10 and female The terminals 20 are electrically connected.
Therefore, the female terminal disclosed in Patent Document 1 has several problems.

  That is, the first problem is that the contact portion 28 is pressed against the outer periphery of the male terminal round pin 10 by the restoring elastic force of the sleeve 23, thereby electrically connecting the female terminal 20 and the male terminal round pin 10. Since contact is intended, it is difficult to increase the contact load itself, which is a problem.

  The second problem is that the contact portion 28 of the sleeve 23 makes electrical contact between the female terminal 20 and the round pin 10 of the male terminal. Therefore, the contact point of the sleeve 23 that presses the round pin 10 of the male terminal. It is difficult to change the spring width of the portion 28, which is a problem.

  As a third problem, since the contact with the outer periphery of the male terminal round pin 10 is only the contact portion 28, the mutual positioning of the axes when the male terminal round pin 10 contacts the male and female terminals. This is a problem.

  The object of the present invention is to position each other's shafts at the time of contact between the male and female terminals of the round pin terminal, and to easily improve the contact load on the round pin terminal of the male terminal, thereby improving the contact reliability. It is to provide a female terminal.

The female terminal of the present invention according to claim 1, which has been made in order to solve the above problems, is provided on a wall portion of an electrical contact portion that forms a cylindrical shape for inserting a round pin of a male terminal to achieve electrical conduction.
A first elastic contact piece formed in an arc shape so as to be wound toward the central axis so as to cover the axial direction of the round pin;
A second elastic contact piece formed in an arc shape so as to cover the axial direction of the round pin and wind toward the central axis is provided at a position facing the first elastic contact piece,
The male terminal is pressed and held by two surfaces by the first elastic contact piece and the second elastic contact piece.

  According to the first aspect of the present invention, the first elastic contact piece and the second elastic contact piece are formed on the wall portion of the electric contact portion having a cylindrical shape for inserting the round pin of the male terminal to achieve electrical conduction. And the male terminal is pressed and held by the two surfaces of the first elastic contact piece and the second elastic contact piece, respectively, so that the springs of the first elastic contact piece and the second elastic contact piece of the female terminal are A large width can be secured, the contact load can be easily increased as compared with the conventional terminal, the width can be adjusted according to the required contact load, the inner surface of the first elastic contact piece and the second elastic contact piece The shafts can be positioned when the male and female terminals of the round pin terminal are in contact with the inner surface.

  In order to solve the above-mentioned problems, the female terminal according to the present invention as claimed in claim 2 is characterized in that the first elastic contact piece and the second elastic contact piece of the female terminal according to claim 1 are replaced with a round pin of a male terminal. In parallel with the insertion direction, the wall portion of the electrical contact portion is formed in a slit shape.

  According to the second aspect of the present invention, the female terminal can be formed by punching a single plate and bending it into an arc shape.

  The female terminal of the present invention according to claim 3, which has been made to solve the above-mentioned problems, is characterized in that the first elastic contact piece and the second elastic contact piece of the female terminal according to claim 2 are connected to the electric contact. It is formed in a circular arc shape toward the axial center of the part, and has a spring property to press against the central axis method of the round pin of the male terminal.

  According to the third aspect of the present invention, even if the diameter of the round pin of the male terminal is changed, it is possible to cope with the change, and it is possible to press in the central axis direction of the round pin of the male terminal.

  The female terminal of the present invention according to claim 4, which has been made in order to solve the above-mentioned problem, has a curvature of inner surfaces of the first elastic contact piece and the second elastic contact piece of the female terminal according to claim 3. The curvature (arc shape) of the outer peripheral surface of the round pin of the male terminal is the same as or smaller than the curvature (arc shape) of the outer periphery of the round pin of the male terminal.

  According to the fourth aspect of the present invention, the curvatures of the inner surfaces of the first elastic contact piece and the second elastic contact piece are the same as the curvature (arc shape) of the outer peripheral surface of the round pin of the male terminal, or male Since the curvature of the outer periphery of the terminal round pin (arc shape) is smaller, the outer peripheral surface of the male terminal round pin is formed by the inner surface of the first elastic contact piece and the inner surface of the second elastic contact piece. A sufficient contact load to be pressed can be ensured.

According to the present invention, the inner surface of the first elastic contact piece and the inner surface of the second elastic contact piece press the outer peripheral surface of the round pin of the male terminal. The spring width of the elastic contact piece can be secured large, the contact load can be easily increased as compared with the conventional terminal, and the width can be adjusted according to the required contact load.
In addition, according to the present invention, since the outer peripheral surface of the round pin of the male terminal is pressed by the inner surface of the first elastic contact piece and the inner surface of the second elastic contact piece, the contact load on the round pin terminal of the female terminal Can be improved easily.
Furthermore, according to the present invention, since the round pin terminal of the male terminal is sandwiched and held between the inner surface of the first elastic contact piece and the inner surface of the second elastic contact piece, the contact reliability can be improved.
In addition, according to the present invention, the entire outer peripheral surface of the round pin of the male terminal is pressed toward the central axis by the inner surface of the first elastic contact piece and the inner surface of the second elastic contact piece. It is possible to position the axes of each other when the male and female terminals are in contact.

It is a whole perspective view of the female terminal concerning the present invention. It is a top view of the expansion | deployment shape of the electrical contact part of the female terminal shown in FIG. It is a side view of the electrical contact part of the female terminal shown in FIG. FIG. 2 is a front view of the female terminal illustrated in FIG. 1. It is a perspective view of the female terminal for demonstrating mounting | wearing of the round pin terminal of a male terminal to the electrical contact part of the female terminal shown in FIG. It is a side view of the female terminal before mounting | wearing with the round pin terminal of a male terminal in the electrical contact part of the female terminal shown in FIG. It is a perspective view of the female terminal which shows the state which inserted the round pin terminal of the male terminal in the electrical contact part of the female terminal shown in FIG. It is a side view of the female terminal which shows the state which the electric contact part deform | transformed, after mounting | wearing the round pin terminal of a male terminal with the electric contact part of the female terminal shown in FIG. It is a side view of the female terminal for demonstrating the axial alignment effect | action by an elastic contact piece, after attaching the round pin terminal of a male terminal to the electrical contact part of a female terminal, and deform | transforming an electrical contact part. It is a front view of the female terminal which shows the state which changed the electrical contact part, after attaching the round pin terminal of a male terminal to the electrical contact part of the female terminal shown in FIG. It is AA sectional drawing of the female terminal shown in FIG. It is a front view which shows the conventional female terminal.

  Embodiments of the present invention will be described below with reference to the drawings.

Drawing 1-FIG. 11 show the Example of the female terminal based on this invention.
1 is an overall perspective view of a female terminal according to the present invention, FIG. 2 is a plan view of a developed shape of an electrical contact portion of the female terminal shown in FIG. 1, and FIG. 3 is an electrical contact portion of the female terminal shown in FIG. 4 is a front view of the female terminal shown in FIG. 1, and FIG. 5 is a perspective view of the female terminal for explaining the mounting of the round pin terminal of the male terminal on the electrical contact portion of the female terminal shown in FIG. 6 is a side view of the female terminal before the male pin round pin terminal is mounted on the electrical contact portion of the female terminal shown in FIG. 1, and FIG. 7 is a male terminal on the electrical contact portion of the female terminal shown in FIG. FIG. 8 is a perspective view of the female terminal showing a state in which the round pin terminal is inserted, and FIG. 8 shows a state in which the electrical contact portion is deformed after the male pin round pin terminal is attached to the electrical contact portion of the female terminal shown in FIG. FIG. 9 is a side view of the female terminal. FIG. 9 shows the axial centering action by the elastic contact piece after the male contact round pin terminal is mounted on the electrical contact part of the female terminal and the electrical contact part is deformed. FIG. 10 is a front view of the female terminal showing a state in which the electrical contact portion is deformed after the male pin round pin terminal is attached to the electrical contact portion of the female terminal shown in FIG. 11 is a cross-sectional view taken along line AA of the female terminal shown in FIG. 10, and FIG. 12 is a front view showing the conventional female terminal.

FIG. 1 shows an entire female terminal 1 according to the present invention.
In FIG. 1, the female terminal 1 includes an electrical contact portion 2 formed in a hollow cylindrical shape, and a wire crimping portion 3 extending from the rear end of the electrical contact portion 2. The female terminal 1 is formed by pressing a conductive metal plate such as copper.

The metal plate 4 is formed by stamping the metal plate into a shape as shown in FIG. The metal plate 4 forms a wall 2a of the electrical contact portion 2 of the female terminal 1, and the electrical contact portion 2 of the female terminal 1 is formed by forming the metal plate 4 into a cylindrical shape.
The metal plate 4 has the same distances a1 and a2 from the center line O to the end portions 5 and 6 in the width direction. A U-shaped slit 7 is provided on one end 5 side of the metal plate 4, and the first elastic contact piece 8 is formed by providing the slit 7. Therefore, the first elastic contact piece 8 is bent at the root portion 10 of the first elastic contact piece 8 at the end 9 of the slit 7.

  A second elastic contact piece 11 is provided on the other end 5 side of the metal plate 3. The second elastic contact piece 11 is formed to protrude outward from the end portion 5, and a slit 12 in a direction perpendicular to the center line O of the metal plate 4 is formed at a joint portion on both sides of the end portion 5. 13 is provided. Therefore, the second elastic contact piece 11 is bent at the root portion 14 of the second elastic contact piece 11 at the ends 12 a and 13 a of the slits 12 and 13.

The length b1 of the first elastic contact piece 8 in the direction perpendicular to the center line O of the metal plate 4 and the length b2 of the second elastic contact piece 11 in the direction perpendicular to the center line O of the metal plate 4 are , Are formed to be the same length.
As described above, the base portion 10 of the first elastic contact piece 8 and the base portion 14 of the second elastic contact piece 11 are formed on the metal plate 3 along the terminal length (axis) direction.

The metal plate 4 is rounded along the center line O to form a wall 2a, and is formed in a cylindrical shape by contacting one end 5 of the metal plate 4 and the other end 6 of the metal plate 4. . The metal plate 4 is rounded to form a storage portion 15 for storing the male pin round pin terminal.
The metal plate 4 is rounded to form a storage portion 15 for storing the male pin round pin terminal. When the metal plate 4 is rolled into a cylindrical shape, as shown in FIG. 3, the first elastic contact piece 8 and the second elastic contact piece 11 have a circular arc ( The arc is smaller than (curvature).
Therefore, the first elastic contact piece 8 and the second elastic contact piece 11 are centered against a force that pushes the first elastic contact piece 8 and the second elastic contact piece 11 outward. A force acts toward the axis. That is, the first elastic contact piece 8 and the second elastic contact piece 11 have spring properties in the direction toward the central axis.

Thus, the circular arc (curvature) of the first elastic contact piece 8 and the circular arc (curvature) of the second elastic contact piece 11 rounded into a cylindrical shape are formed identically. Accordingly, the first elastic contact piece 8 and the second elastic contact piece 11 are formed to vortex when viewed from the side of the electrical contact portion 2 of the female terminal 1 in FIG.
Therefore, when the metal plate 4 is rolled, the second elastic contact piece 11 is in a state of being lowered toward the central axis by the slits 12 and 13 rather than the position of the wall of the metal plate 4 as shown in FIG. It is involved. For this reason, the notch 16 is formed in the wall 2 a of the metal plate 4.
Similarly, as shown in FIG. 5, the first elastic contact piece 8 is also wound into a state where the first elastic contact piece 8 is lowered toward the central axis from the position of the wall 2 a of the metal plate 4 by the U-shaped slit 7. Yes. For this reason, the notch 17 is formed in the wall 2 a of the metal plate 4.

As shown in FIG. 5, a round pin terminal 31 of a male terminal 30 is inserted into the electrical contact portion 2 of the female terminal 1 from the front end side thereof. The round pin terminal 31 of the male terminal 30 is formed of a conductive metal such as copper.
The round pin terminal 31 of the male terminal 30 is connected to the female terminal 1 by being inserted into the electrical contact portion 2 of the female terminal 1 of the round pin terminal 31 of the male terminal 30, and the female terminal 1 and the male terminal 30 are connected to each other. Conducted.

The wire crimping portion 3 is for crimping and fixing an electric wire (not shown), a conductor crimping piece 18 for crimping a conductor of the electric wire (not shown), and a sheath for fixing the electric wire by crimping to the coating portion of the electric wire. A crimping piece 19 is provided.
The electric wire crimping portion 3 includes a pair of conductor crimping pieces 18a and 18b formed so as to expand the blades, and the electric wire conductor is sandwiched between the pair of conductor crimping pieces 18a and 18b. The pair of conductor crimping pieces 18a and 18b are crimped and crimped.
Further, the electric wire crimping portion 3 includes a pair of covering crimping pieces 19a and 19b formed so as to expand the blades on the upper side, and the electric wire covering portion 19b is interposed between the pair of covering crimping pieces 19a and 19b. The wire is fixed by crimping with a pair of covering crimping pieces 19a and 19b.

The electrical contact portion 2 of the female terminal 1 is the housing portion 15 for the round pin terminal 31 of the male terminal 30, and the front end side opposite to the wire crimping portion 3 is the round pin terminal 31 of the male terminal 30. Is an insertion port 20 through which is inserted and removed.
The first elastic contact piece 8 and the second elastic contact piece 11 before inserting the round pin terminal 31 of the male terminal 30 in the electrical contact portion 2 of the female terminal 1 are, as shown in FIG. Since nothing is inserted between the piece 8 and the second elastic contact piece 11, the positional relationship between the first elastic contact piece 8 and the second elastic contact piece 11 is the electrical contact portion 2 of the female terminal 1. When viewed from the side, the shape is the same as when the female terminal 1 is manufactured.

Now, from the state shown in FIG. 6, the round pin terminal 31 of the male terminal 30 is connected to the first elastic contact piece 8 and the second through the insertion port 20 of the electrical contact portion 2 of the female terminal 1 as shown in FIG. 7. It inserts between the elastic contact pieces 11. Then, the 1st elastic contact piece 8 and the 2nd elastic contact piece 11 are pushed and expanded in the diameter expansion direction.
When the round pin terminal 31 of the male terminal 30 is inserted into the electrical contact portion 2 of the female terminal 1, the first elastic contact piece 8 and the second elastic contact piece 11 are deformed in the diameter increasing direction as shown in FIG. Thus, a force that winds toward the central axis is exerted by the spring force of the first elastic contact piece 8 and the second elastic contact piece 11.

  As described above, when the first elastic contact piece 8 and the second elastic contact piece 11 are deformed in the diameter increasing direction by the insertion of the round pin terminal 31, the first elastic contact piece 8 and the second elastic contact piece 11 are used. As shown in FIG. 9, a force (spring force) from the first elastic contact piece 8 and the second elastic contact piece 11 toward the central axis is applied to the round pin terminal 31 of the male terminal 30 inserted between Works.

That is, since the first elastic contact piece 8 is formed in an arc shape, the round pin terminal 31 of the male terminal 30 is wound and pressed toward the central axis as shown in FIG. Due to the spring force toward the central axis of the first elastic contact piece 8, the round pin terminal 31 of the male terminal 30 is pressed in the direction indicated by the arrows c1 and c2 shown in FIG.
Further, since the second elastic contact piece 11 is formed in an arc shape, as shown in FIG. 9, the round pin terminal 31 of the male terminal 30 is wound and pressed toward the central axis. The round pin terminal 31 of the male terminal 30 is pressed in the direction indicated by the arrows d1 and d2 illustrated in FIG. 9 by the spring force toward the central axis of the second elastic contact piece 11.

In this way, the circular pin terminal 31 of the male terminal 30 is inserted between the first elastic contact piece 8 and the second elastic contact piece 11 from the insertion port 20 of the electrical contact portion 2 of the female terminal 1, and the female terminal When the electric contact portion 2 of 1 is deformed by applying a force from the outside, the round pin terminal 31 of the male terminal 30 is fixed to the electric contact portion 2 of the female terminal 1 as shown in FIG.
When the round pin terminal 31 of the terminal 30 is fixed to the electrical contact portion 2 of the female terminal 1, the round pin terminal 31 of the male terminal 30 is connected to the first elastic contact piece 8 and the second elastic contact as shown in FIG. It will be in the state pressed down with the piece 11. FIG.

The position of the first elastic contact piece 8 formed on the wall 2a of the electrical contact portion 2 of the female terminal 1 and the position of the second elastic contact piece 11 formed on the wall 2a of the electrical contact portion 2 of the female terminal 1 Is provided at a position opposite to the center axis symmetrically when the metal plate 4 is rounded along the center line O to form a cylindrical shape.
Therefore, the contact position of the male terminal 30 of the first elastic contact piece 8 to the round pin terminal 31 and the contact position of the male terminal 30 of the second elastic contact piece 11 to the round pin terminal 31 are round. The center axis of the pin terminal 31 is symmetrically opposed.

The first elastic contact piece 8 and the second elastic contact piece 11 have the same spring property because the metal plate 4 is formed by press working, and the central axis of the round pin terminal 31 is symmetrical. The force when pressing from the opposite position toward the central axis of the round pin terminal 31 is the same. For this reason, when the round pin terminal 31 of the male terminal 30 is inserted into the electrical contact portion 2 of the female terminal 1, the first elastic contact piece 8 and the second elastic contact piece 11 connect the round pin terminal 31 of the male terminal 30. The central axis of the round pin terminal 31 is symmetrically pressed toward the central axis of the round pin terminal 31 from an opposite position.
By the action of the first elastic contact piece 8 and the second elastic contact piece 11, the round pin terminal 31 of the male terminal 30 is aligned. Further, since the first elastic contact piece 8 and the second elastic contact piece 11 press the round pin terminal 31 of the male terminal 30 from both sides symmetrically with respect to the central axis, the axial displacement of the round pin terminal 31 of the male terminal 30 is increased. Can be suppressed.

Further, the first elastic contact piece 8 and the second elastic contact piece 11 have root portions 10 and 14 formed along the terminal length (axis) direction of the female terminal 1, and the round pin of the male terminal 30. It forms in the length direction of the electric contact part 2 of the female terminal 1 so that the terminal 31 may be wound.
For this reason, the contact length with the round pin terminal 31 of the male terminal 30 of the 1st elastic contact piece 8 and the 2nd elastic contact piece 11 can be ensured long, a contact load can be improved, and connection reliability Can be improved.
Thus, the width of the spring of the female terminal 1 can be secured large, and the contact load can be easily increased as compared with the conventional terminal.
And according to the present Example, since the width | variety of a spring can be ensured large, the width | variety of a spring can be adjusted according to a contact load.

Furthermore, the first elastic contact piece 8 and the second elastic contact piece 11 have root portions 10 and 14 formed along the terminal length (axis) direction of the female terminal 1, and the round pin of the male terminal 30. The first elastic contact piece 8 is bent along the base portion 10, and the second elastic contact piece 11 is bent at the root portion 14. It is formed so that the diameter can be expanded in the radial direction. For this reason, the contact load can be ensured by increasing or decreasing the diameter in the radial direction around the root portions 10 and 14.
The first elastic contact piece 8 and the second elastic contact piece 11 have base portions 10 and 14 formed along the terminal length (axis) direction of the female terminal 1, and the spring of the female terminal 1 Since the width can be gained, the contact load can be easily increased.

  In addition, the present invention can of course be modified in various ways within the scope not changing the gist of the present invention.

1 …………………… Female terminal 2 …………………… Electric contact part 2a ………………… Wall 3 …………………… Wire caulking part 4 ………… ………… Metal plate 5, 6 ……………… End 7 …………………… Slit 8 …………………… First elastic contact piece 9 …………………… … End 10 ………………… Root 11 …………… Second elastic contact piece 12, 13 ………… Slit 14 ………………… Root 15 ………… ……… Housing compartment 16, 17 ………… Notch 18 ………………… Conductor caulking piece 19 ………………… Coating caulking piece 20 ………………… Insertion port 30… ……………… Male terminal 31 ………………… Round pin terminal

Claims (4)

Insert the round pin of the male terminal into the wall part of the electrical contact part that forms a cylinder to achieve electrical conduction,
A first elastic contact piece formed in an arc shape so as to be wound toward the central axis so as to cover the axial direction of the round pin;
A second elastic contact piece formed in an arc shape so as to cover the axial direction of the round pin and wind toward the central axis is provided at a position facing the first elastic contact piece,
A female terminal, wherein the first elastic contact piece and the second elastic contact piece press and hold the male terminal on two surfaces.
The first elastic contact piece and the second elastic contact piece are:
2. The female terminal according to claim 1, wherein a wall portion of the electrical contact portion is formed in a slit shape in parallel with the insertion direction of the round pin of the male terminal.
The first elastic contact piece and the second elastic contact piece are:
3. The female terminal according to claim 2, wherein the female terminal is formed in an arc shape toward an axis of the electrical contact portion and has a spring property to press in a central axis direction of a round pin of the male terminal.
The curvatures of the inner surfaces of the first elastic contact piece and the second elastic contact piece are:
The curvature (arc shape) of the outer peripheral surface of the round pin of the male terminal is the same as or smaller than the curvature (arc shape) of the outer periphery of the round pin of the male terminal. Female terminal as described in.

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