JP2012124072A - Female terminal fitting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a female terminal fitting capable of reducing insertion force without deteriorating connection reliability.SOLUTION: A female side terminal fitting 10 is equipped with a cylindrical connecting portion 11, and provided with an elastically contacting piece 12 elastically contacting with a male tub 21 on a counterpart side in the connecting portion 11. The elastically contacting piece 12 has a first fulcrum portion 16 contacting with a bottom plate 11A of the connecting portion 11 in a natural state. A part from the first fulcrum portion 16 to a contact portion 15 contacting with the male tub 21 is shaped in a gentle arc projecting to the bottom plate 11A side. As the contact portion 15 contacts with the male tub 21 to elastically bend the elastically contacting piece 12, a part closer to the contact portion 15 than the first fulcrum portion 16 contacts with the bottom plate 11A to be a second fulcrum portion 17.

Description

  The present invention relates to a female terminal fitting.

  Conventionally, a female terminal fitting that can be connected to a mating male terminal fitting is known (for example, Patent Document 1). This female terminal fitting is provided with a cylindrical connecting portion, and an elastic contact piece that elastically contacts the mating male tab is provided inside the connecting portion. The elastic contact piece extends from the fulcrum portion that contacts the bottom plate of the connection portion toward the front so as to gradually move away from the bottom plate, and the portion near the tip serves as a contact portion that contacts the male tab. The elastic contact piece is in a state of being elastically contacted with the male tab inserted into the connection portion, so that a predetermined contact pressure is ensured and connection reliability is enhanced.

Japanese Patent No. 4078564

  In the female terminal fitting having the above-described configuration, when the male tab is inserted into the connection portion, the insertion force increases as the elastic contact piece increases in elasticity with the increase in the amount of bending of the elastic contact piece. growing. Therefore, there is a problem that the insertion force tends to increase when it finally tries to ensure a sufficient contact pressure, and it is difficult to ensure a sufficient contact pressure when the insertion force is reduced.

  This invention is completed based on the above situations, Comprising: It aims at providing the female side terminal metal fitting which can aim at reduction of insertion force, without reducing connection reliability. .

  The female terminal metal fitting of the present invention is a female terminal metal fitting provided with a cylindrical connecting portion, and an elastic contact piece elastically contacting the mating male tab inside the connecting portion. The elastic contact piece has a first fulcrum portion that is in contact with the bottom plate of the connection portion in a natural state, and is loosely convex toward the bottom plate side from the first fulcrum portion to the contact portion that contacts the male tab. As the contact portion comes into contact with the male tab and the elastic contact piece is elastically bent, a portion closer to the contact portion than the first fulcrum portion is in contact with the bottom plate to form a second fulcrum portion. It will be.

  Here, the smaller the length between the contact portion and the fulcrum portion (the portion in contact with the bottom plate) of the elastic contact piece, the larger the elastic force with the same amount of deflection. Therefore, according to the present invention, when the elastic contact piece starts to bend elastically, since the length dimension between the contact portion and the fulcrum portion (first fulcrum portion) is large, the elastic force of the elastic contact piece is When it is small and the connection with the counterpart terminal is completed, the length dimension between the contact portion and the fulcrum portion (second fulcrum portion) is reduced, and the elasticity is increased. Thereby, it is possible to finally secure a sufficient contact pressure while keeping the insertion force of the male tab small, thereby reducing the insertion force without lowering the connection reliability.

  Moreover, the part on the opposite side to the said contact part of the said 1st fulcrum part among the said elastic contact pieces is good also as what has comprised the shape which floated from the said baseplate.

  ADVANTAGE OF THE INVENTION According to this invention, the female terminal metal fitting which can aim at reduction of insertion force can be provided, without reducing connection reliability.

Partial enlarged sectional view of the female terminal fitting according to the present embodiment Exploded view of female terminal fitting Partial enlarged sectional view of the female terminal fitting showing the state where the male tab starts to hit the elastic contact piece Partially enlarged sectional view of the female terminal fitting showing a state where the elastic contact piece is bent and the fulcrum portion is moved Partially enlarged sectional view of the female terminal fitting showing a state where the connection with the male terminal fitting is completed Partially enlarged sectional view of a conventional female terminal fitting Partial enlarged sectional view of another type of female terminal fitting A graph schematically showing the relationship between the amount of flexure and elasticity for each type of female terminal fitting

<Embodiment>
DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment embodying the present invention will be described in detail with reference to FIGS.
The female terminal fitting 10 in the present embodiment is connected to a terminal of an electric wire (not shown), is connected to the mating male terminal fitting 20, and is coupled to a male tab 21 provided on the male terminal fitting 20. Hereinafter, in each component, the left side in FIG. 1 (the side to which the male terminal fitting 20 is connected) will be referred to as the front, the opposite side as the rear, the upper side as the upper side, and the lower side as the lower side.

  As shown in FIG. 2, the female terminal metal fitting 10 presses a conductive plate material to form a terminal forming plate material 32 connected to the strip 31 at a predetermined interval, and this terminal forming plate material 32. After the female terminal fittings 10 are formed by bending, cutting and punching, etc., the female terminal fittings 10 are separated from the strips 31.

  The female terminal fitting 10 includes a cylindrical connection portion 11 into which the male tab 21 is inserted, and an elastic contact piece 12 that elastically contacts the male tab 21 is provided inside the connection portion 11. Is. The female terminal fitting 10 has an elongated shape in the front-rear direction as a whole, and a barrel portion connected to the end of the electric wire is provided behind the connection portion 11, and the barrel portion is an insulation for caulking the coating of the electric wire. A barrel and a wire barrel for caulking the core of the electric wire are provided. 2 shows the insulation barrel constituting part 33 and the wire barrel constituting part 34 respectively constituting the insulation barrel and the wire barrel after the terminal forming plate material 32 is bent.

  The connecting portion 11 is formed in a rectangular tube shape that is elongated in the front-rear direction. Specifically, the bottom plate 11A, a pair of side plates 11B that rises upward from both edges in the width direction of the bottom plate 11A, and one upper end of the pair of side plates 11B. The top plate 11C is bent toward the other upper end and arranged substantially parallel to the bottom plate 11A. A male tab 21 is inserted into the connecting portion 11 from a tab insertion hole 13 provided in the front. In addition, the front-end | tip part 22 of the male tab 21 has comprised the shape where thickness dimension (up-down direction dimension) becomes small gradually toward the front-end | tip.

  A contact portion 14 that contacts the male tab 21 from the side opposite to the elastic contact piece 12 is formed on the top plate 11C. The contact portion 14 is formed by knocking the top plate 11C partially inward (downward), and has a shape that is long in the front-rear direction (see FIG. 2). The contact portion 14 is formed in a portion near the front end of the top plate 11C, and substantially the whole is parallel to the bottom plate 11A. In a state where the male terminal fitting 20 and the female terminal fitting 10 are properly connected, the leading end portion 22 of the male tab 21 reaches the rear end position of the contact portion 14, and substantially the entire contact portion 14 contacts the male tab 21. (See FIG. 5).

  An elastic contact piece 12 that elastically contacts the male tab 21 is provided in the connection portion 11. The elastic contact piece 12 has a cantilever shape extending forward along the bottom plate 11A and is elastically deformable in the vertical direction. A portion near the tip of the elastic contact piece 12 is a contact portion 15 that contacts the male tab 21. The contact portion 15 is formed to bulge upward by embossing, and the distance between the contact portion 15 and the contact portion 14 is slightly smaller than the thickness of the male tab 21 in the natural state of the elastic contact piece 12. Is set to As shown in the developed view of FIG. 2, the contact portion 15 has a shape that is long in the front-rear direction when viewed from above, and the front end side is narrow. Further, the cross-sectional shape of the contact portion 15 viewed from the side has a mountain shape in which the inclination of the rear portion is tighter than the front portion.

  The elastic contact piece 12 has a first fulcrum portion 16 that contacts the bottom plate 11A of the connection portion 11 in a natural state. The first fulcrum part 16 is located rearward of the contact part 14. The elastic contact piece 12 is bent and formed in a loose arc shape continuously extending forward and rearward of the first fulcrum part 16 with the first fulcrum part 16 on the lower side. Thereby, from the 1st fulcrum part 16 to the contact part 15, a convex arc is formed on the bottom plate 11A side, and the rear part of the first fulcrum part 16 (the part opposite to the contact part 15) is It is in a state of floating from the bottom plate 11A. The amount of lifting from the bottom plate 11A is smaller than the amount of lifting of the contact portion 15 from the bottom plate 11A.

  As the contact portion 15 comes into contact with the male tab 21 and the elastic contact piece 12 is elastically bent, a portion on the front side of the first fulcrum portion 16 (portion close to the contact portion 15) is in contact with the bottom plate 11A. It becomes the two fulcrum parts 17 (the movement of such fulcrum parts will be described in detail later). In the development view of FIG. 2, the contact piece constituting portion 35 constituting the elastic contact piece 12 after being bent or the like is shown. The contact piece component 35 is elongated in the front-rear direction as a whole, and the front end portion is narrower than the rear end portion.

  On the bottom plate 11A of the connecting portion 11, a bending allowance window 18 that allows the elastic contact piece 12 to bend downward is opened. The bending allowance window 18 is formed at a position corresponding to the lower side of the tip end portion of the elastic contact piece 12 in the bottom plate 11A, and when the elastic contact piece 12 is elastically bent downward, the tip end portion is fitted into the bend allowance window 18. The amount of elastic deflection of the elastic contact piece 12 is increased by being stuck.

  Next, the connection operation between the female terminal fitting 10 and the male terminal fitting 20 will be described with reference to the graph of FIG. The graph of FIG. 8 shows the elastic force of the elastic contact piece (the force by which the contact portion 15 pushes the male tab 21 upward) with respect to the amount of bending of the elastic contact piece (the amount of downward displacement of the contact portion 15). The analysis is made by CAE (Computer Aided Engineering). The X axis indicates the amount of bending of the elastic contact piece, and the Y axis indicates the elastic force of the elastic contact piece. Further, in the graph of FIG. 8, the elastic force R <b> 1 (shown by a solid line) of the elastic contact piece 12 of the female terminal fitting 10 of the present embodiment and a conventional type which will be described later for comparison with this. The elastic force R2 (shown by a dotted line) of the elastic contact piece 41 of the female terminal fitting 40 and the elastic force R3 (shown by a dashed line) of the elastic contact piece 51 of another type of female terminal fitting 50 Show.

  When the female terminal fitting 10 and the male terminal fitting 20 are connected, when the male tab 21 of the male terminal fitting 20 is inserted from the front with respect to the connecting portion 11 of the female terminal fitting 10, the male tab 21 is Passing through the tab insertion hole 13 of the female terminal fitting 10, the front end portion 22 reaches between the front end of the elastic contact piece 12 and the front end of the contact portion 14 (see FIG. 3). At this time, the elastic contact piece 12 is still in a natural state, and the amount of bending and the elastic force of the elastic contact piece 12 are zero (the origin in the graph of FIG. 8).

  Then, when the connecting operation of both the terminal fittings 10 and 20 is advanced, the tip of the male tab 21 interrupts between the contact part 14 of the connection part 11 and the contact part 15 of the elastic contact piece 12, and accordingly the elastic contact piece. 12 is elastically bent downward. Further, as shown in FIG. 4, the portion of the elastic contact piece 12 that contacts the bottom plate 11A gradually spreads forward from the first fulcrum portion 16, and the contact area between the elastic contact piece 12 and the bottom plate 11A gradually increases. To do. When the amount of bending of the elastic contact piece 12 reaches a predetermined amount (about 0.12 mm in this embodiment), the contact portion stops without showing any further spread. The front end portion of the contact portion at this time becomes the second fulcrum portion 17. During this time, the resilience increases at a substantially constant rate.

  When the connection operation of both the terminal fittings 10 and 20 is further advanced, the distal end portion 22 of the male tab 21 gets over the contact portion 15 and its rear portion is sandwiched between the contact portion 15 and the contact portion 14. Both terminal fittings 10 and 20 are in a normal connection state (see FIG. 5). At this time, the tip of the elastic contact piece 12 is in a state where it enters the bending allowance window 18, and the second fulcrum portion 17 of the elastic contact piece 12 is approximated to support the elastic contact piece 12 at one point. It will be in the state. That is, until then, the elastic contact piece 12 was supported by the surface extending from the first fulcrum part 16 to the second fulcrum part 17, but the supporting force for supporting the elastic contact piece 12 is the second fulcrum part 17. It comes to act biased to the side, and eventually the support force is concentrated on the second fulcrum part 17. During this time, the resilience increases at a greater rate than before.

Next, the operation and effect of the present embodiment configured as described above will be described.
The female terminal fitting 10 of the present embodiment includes a cylindrical connecting portion 11, and an elastic contact piece 12 that elastically contacts the mating male tab 21 is provided inside the connecting portion 11. It is the female side terminal metal fitting 10, Comprising: The elastic contact piece 12 has the 1st fulcrum part 16 which contacts the bottom plate 11A of the connection part 11 in a natural state, and the contact part 15 which contacts the male tab 21 from the 1st fulcrum part 16. The bottom plate 11A side is convexly loosely arcuate, and the contact portion 15 contacts the male tab 21 and the elastic contact piece 12 is elastically bent, so that the portion is closer to the contact portion 15 than the first fulcrum portion 16 is. Is in contact with the bottom plate 11A to form the second fulcrum portion 17.
The elastic contact piece 12 has a shape in which the rear portion of the first fulcrum portion 16 is lifted from the bottom plate 11A.

  Here, the conventional female terminal fitting 40 in which the first fulcrum portion 42 of the elastic contact piece 41 does not move, and another female terminal fitting 50 in which the rear portion of the elastic contact piece 51 is in close contact with the bottom plate 11A. For the above, the elastic force of the elastic contact piece with respect to the amount of bending of the elastic contact piece is analyzed by CAE and compared with the female terminal fitting 10 of this embodiment (hereinafter referred to as the new female terminal fitting 10). .

  First, the structure of a conventional female terminal fitting 40 and another female terminal fitting 50 will be described. The conventional female terminal fitting 40 and the different female terminal fitting 50 differ from the new female terminal fitting 10 only in the way of bending the elastic contact pieces 41 and 51, except for the other types. The configuration is the same. The elastic contact pieces 41 and 51 of the conventional female terminal fitting 40 and the different female terminal fitting 50 are formed by bending the same contact piece constituting portion 35 as the elastic contact piece 12 of the new female terminal fitting 10. Like the elastic contact piece 12 of the new female terminal fitting 10, it has a cantilever shape extending forward along the bottom plate 11A, and is elastically deformable in the vertical direction. And the part near the front-end | tip of the elastic contact pieces 41 and 51 is made into the contact part 15 which contacts the male tab 21. FIG.

  The elastic contact piece 41 of the conventional female terminal fitting 40 has a form in which the first fulcrum part 42 is in point contact with the bottom plate 11A, and extends straightly upward from the first fulcrum part 42 toward the front. The first fulcrum part 42 of the elastic contact piece 41 is positioned slightly in front of the first fulcrum part 16 of the new female terminal fitting 10.

  The elastic contact piece 51 of another type of female terminal fitting 50 has a configuration in which the entire rear side portion is in contact with the bottom plate 11A (a configuration in which the rear lifting of the first fulcrum 16 is eliminated in the new type female terminal fitting 10). The entire contact portion is the first fulcrum portion 52 that is in contact with the bottom plate 11A in a natural state. The first fulcrum part 52 of the elastic contact piece 51 is a part that spreads backward from the same position as the first fulcrum part 16 of the new female terminal fitting 10. The elastic contact piece 51 extends in a loose arc shape from the first fulcrum portion 52 toward the front.

  The elastic contact piece 41 of the conventional female terminal fitting 40 is elastically bent using only the first fulcrum portion 42 as a fulcrum from the beginning of insertion of the male tab 21 until the insertion operation is completed. The elasticity increases at a certain rate.

  Further, another type of female-side terminal fitting 50 has a bottom plate 11A of the elastic contact piece 51 from the beginning of insertion of the male tab 21 until the male tab 21 rides over the contact portion 15 (until the amount of deflection becomes about 0.15 mm). The contact portion of the contact portion spreads forward from the first fulcrum portion 52 to increase the contact area, and then the front end portion (second fulcrum portion) of the contact portion with the bottom plate 11A supports the elastic contact piece 51 at one point. It becomes a state that approximates to do.

Next, the elasticity of the elastic contact pieces 12, 41, 51 will be compared for the three types of female terminal fittings 10, 40, 50.
First, until the bending amount reaches about 0.14 mm, that is, until the insertion operation of the male tab 21 is almost completed, the elastic force of the new elastic contact piece 12 is changed to the conventional elastic contact piece 41. It is kept smaller than the resilience of. When the deflection amount exceeds about 0.14 mm, the elastic force of the new elastic contact piece 12 becomes larger than the elastic force of the conventional elastic contact piece 41, and the insertion operation of the male tab 21 is completed. When this occurs (when the amount of deflection is about 0.15 mm), the elastic force is greater than that of the conventional elastic contact piece 41. That is, the new female terminal fitting 10 can suppress the insertion force of the male tab 21 to be smaller than that of the conventional female terminal fitting 40, and the final contact pressure with the male tab 21 is the conventional type. The contact pressure of the female terminal fitting 40 can be made larger. Accordingly, it is possible to finally secure a sufficient contact pressure while keeping the insertion force of the male tab 21 small, and thus it is possible to reduce the insertion force without lowering the connection reliability.

  Further, another type of the female terminal fitting 50 can suppress the elastic force to be smaller (about half) than that of the conventional female terminal fitting 40 until the insertion operation of the male tab 21 is almost completed. In the end, it is possible to obtain a contact pressure that is slightly smaller than that of the conventional female terminal fitting 40 but close to that. Accordingly, it is possible to finally secure a large contact pressure as compared with that while suppressing the insertion force of the male tab 21 to be small.

  Since the new female terminal fitting 10 has a shape in which the rear portion of the first fulcrum portion 16 of the elastic contact piece 12 is lifted from the bottom plate 11A, it is the same as the other female terminal fitting 50. While having the characteristics (characteristic that the insertion force is small and the final contact pressure is larger than that), it is possible to obtain a contact pressure much higher than that of the female terminal fitting 50 of another type.

DESCRIPTION OF SYMBOLS 10, 40, 50 ... Female side terminal metal fitting 11 ... Connection part 11A ... Bottom plate 12, 41, 51 ... Elastic contact piece 15 ... Contact part 16, 42, 52 ... 1st fulcrum part 17 ... 2nd fulcrum part 21 ... Male tab

Claims (2)

A female terminal fitting provided with a cylindrical connection part, and provided with an elastic contact piece that elastically contacts the male tab on the other side inside the connection part,
The elastic contact piece has a first fulcrum portion that contacts the bottom plate of the connection portion in a natural state, and has a loose arc shape convex toward the bottom plate side from the first fulcrum portion to the contact portion that contacts the male tab. None, as the contact portion comes into contact with the male tab and the elastic contact piece is elastically bent, a portion closer to the contact portion than the first fulcrum portion is in contact with the bottom plate and becomes a second fulcrum portion. Female terminal fitting.   2. The female terminal fitting according to claim 1, wherein a portion of the elastic contact piece on the side opposite to the contact portion of the first fulcrum portion has a shape floating from the bottom plate.

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