JP5252231B2 - Female terminal - Google Patents

Description

  The present invention relates to a female terminal.

  For example, what was described in patent document 1 is known as a female terminal used for the connection of the wire harness of a large current circuit. This female terminal includes a rectangular tube-like connecting portion into which a tab of a mating male terminal is inserted, and is formed as a separate body including a leaf spring bent into a substantially mountain shape, for example, on the bottom surface of this connecting portion. A structure in which a spring member is mounted. When the tab of the male terminal is inserted into the connecting portion to connect the male and female terminal fittings, the tab is pushed in while elastically displacing the leaf spring. When the tab is inserted to a predetermined position, it receives the restoring elasticity of the leaf spring. Thus, the tab is pressed against the ceiling surface of the connecting portion so that the male and female terminal fittings are electrically connected.

JP 2006-12741 A

In the above prior art, a leaf spring is used as a spring member in order to bring the tab into elastic contact with the ceiling surface of the connection portion. This leaf spring has a spring characteristic, that is, a load-displacement (flexure) characteristic. As shown by the characteristic line i, the linear characteristic is obtained.
On the other hand, since the spring member (leaf spring) in the prior art is formed separately from the connecting portion and is assembled later, there is an error in assembling between the top of the leaf spring and the ceiling surface of the connecting portion. Variations in the height of the space, that is, the insertion space of the tab, are likely to occur. In addition, when the tab of the male terminal is formed by stacking two plate materials, the thickness of the tab may vary.

  If it does so, dispersion | variation in the displacement (deflection) of a leaf | plate spring when a tab is inserted in insertion space can be varied, and a contact load and insertion force will change sensitively. Referring to the characteristic line i in FIG. 15 described above, as an optimum contact form, the displacement of the leaf spring accompanying the insertion of the tab is set to x (mm), and the contact load at that time is set to X (N). In this case, the displacement of the leaf spring can vary. For example, if the displacement is small and stays extremely about x1, the contact load decreases to about X1, which means that the resistance when the tab is inserted is small. However, electrical reliability is lowered. On the other hand, if the displacement is large and about x2, the contact load increases to about X2 and the electrical reliability increases, but the resistance when inserting the tab increases and the workability deteriorates. For this reason, an unreasonable load is applied to the leaf spring, and there is a problem that the leaf spring is likely to sag (deteriorate).

Further, in this type of female terminal, when the tab of the mating male terminal is twisted and inserted into the connecting portion, the internal spring member may be excessively bent and plastically deformed, and an appropriate contact pressure may not be obtained. Therefore, prevention measures are also in demand.
The present invention has been completed on the basis of the above circumstances, and its purpose is to achieve high electrical reliability after obtaining good connection workability when connected to a male terminal of a counterpart. It is in providing a female terminal that can be obtained.

  The female terminal of the present invention is a rectangular tube-like connecting portion into which a tab of a mating male terminal is inserted, and a spring member mounted on one inner surface of the connecting portion, and has a circular periphery with the upper surface bulging. It has a shape, elastically displaces with the insertion of the tab, and after the insertion is completed, it functions to bring the tab into contact with the inner surface on the opposite side of the connecting portion by restoring elasticity, and in the middle of the displacement range with respect to load-displacement characteristics A non-linear characteristic having a region in which the spring constant is close to 0 and a twist amount that is provided on the inner surface of the connecting portion and abuts on the inserted tab when the inserted tab is twisted. And a projecting portion that regulates the pressure.

  According to the said structure, when the tab of the other male terminal is inserted in a connection part, even if the displacement of a spring member changes, the area | region where there is almost no load change can be obtained. Therefore, regardless of variations in the displacement of the spring member, an appropriate contact pressure can be obtained and high electrical reliability can be obtained, and at the same time, an appropriate insertion resistance can be obtained to obtain good connection workability. be able to. In addition, when the tab is twisted and inserted, the amount of twisting is regulated by hitting the protrusion, and as a result, the spring member is prevented from being excessively bent and displaced to be plastically deformed, thereby obtaining an appropriate contact pressure. Can do.

The following configuration may also be used.
(1) A mounting surface of the spring member having a square shape is provided on the one inner surface of the connection portion, and the protrusion is provided at a corner of the mounting surface and on a side of the peripheral edge of the spring member. ing. Since the protrusion for twisting restriction is provided in the dead space, it is possible to cope without causing an increase in size of the connection part itself.

  (2) The protrusions are provided at the four corners of the mounting surface. The amount of twist can be regulated in correspondence with all the twisting operations of the vertical twisting in which the tab swings up and down and the horizontal twisting that rotates around the axis.

  (3) A pair of positioning protrusions are formed on the peripheral edge of the spring member with an interval of 180 degrees, and the inner surfaces of the connecting portion adjacent to the mounting surface of the spring member and facing each other are A positioning recess into which the positioning protrusion is fitted is formed. In the middle of assembling the connecting portion, the positioning protrusions of the spring member are fitted into the positioning recesses on the corresponding inner surface of the connecting portion, so that the disc spring can be positioned on the mounting surface of the connecting portion.

  According to the female terminal of the present invention, high electrical reliability can be obtained after obtaining good connection workability in the case of being connected to the counterpart male terminal.

The expanded view of the female terminal which concerns on Embodiment 1 of this invention Top view of disc spring Cross section Top view of female terminal with built-in disc spring Same part cutaway plan view Bottom view Front view Sectional drawing which shows the state before connection of male and female terminal fittings Partial sectional view of the connected state End view Graph showing load-displacement characteristics of disc spring Sectional drawing of the disc spring which concerns on Embodiment 2. FIG. Sectional drawing of the spring member which concerns on Embodiment 3. FIG. Partially cutaway plan view of a female terminal incorporating a disc spring according to a fourth embodiment Graph showing load-displacement characteristics of a conventional spring member

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
First, the mating male terminal 10 will be described. As shown in FIG. 8, the male terminal 10 is formed by pressing a relatively thick metal plate having excellent conductivity such as a copper alloy, and the electric wire W The tab 13 is formed in the front of the barrel portion 11 that is crimped and crimped to the end of the core wire Wa via the connecting portion 12. The tip of the tab 13 has a tapered shape for the guide.

The female terminal 20 is formed by pressing a relatively thick metal plate that is also excellent in conductivity, such as a copper alloy, and is forward of the barrel portion 21 that is crimped and crimped to the end of the core wire Wa of the electric wire W. In addition, a connecting portion 25 connected to the tab 13 of the male terminal 10 via the connecting portion 22 is formed.
As shown in the development view of FIG. 1, the connecting portion 25 has side portions on the left and right side edges of the bottom portion 26 by bending the horizontally long plate portion 24 at right angles along the folding lines s and t. 27 is formed so as to protrude from the upper edge of each side surface portion 27 so that the top surface portion 28 abuts with each other, so that it is formed in a slightly flat rectangular tube shape that opens in the front-rear direction as a whole. More specifically, the width of the space in the connecting portion 25 is slightly larger than the width of the tab 13 of the male terminal 10, and the height is 1.2 to 1.3 times the thickness of the tab 13. Degree. A predetermined gap 29 is formed between the butted edges of both top surface portions 28.

A square lance hole 31 is formed at the center of the bottom surface portion 26 of the connecting portion 25, and when the female terminal 20 is inserted into a corresponding cavity of a housing (not shown), The provided resin lance fits into the lance hole 31 and is elastically locked, so that the female terminal 20 is prevented from coming off.
On the other hand, on the inner surface of each top surface portion 28, a contact portion 33 made of a ridge facing in the front-rear direction is formed by knocking out. A taper portion 33A is formed at the front end portion of the contact portion 33 for guiding.

On the bottom surface portion 26 of the connection portion 25, a disc spring 40, which is a spring member, is mounted so as to elastically press the tab 13 inserted into the connection portion 25 toward the contact portion 33 described above. Yes.
The disc spring 40 is formed in a conical slope shape with a circular hole 41 opened in the center by pressing a relatively thin metal plate such as a stainless steel plate or a copper alloy plate. More specifically, the inclination angle of the slope is about 6 degrees, and the diameter of the inner peripheral edge 42 has a relatively low free height that is about 1/4 of the diameter of the outer peripheral edge 43. In this embodiment, The diameter of the outer peripheral edge 43 is slightly larger than the lateral width of the space in the connection portion 25 and has a free height of about 40% of the height from the bottom surface portion 26 of the connection portion 25 to the contact portion 33.

  A pair of positioning projections 45 are formed in a horizontal posture and projecting in opposite directions at positions spaced apart by 180 degrees on the outer peripheral edge 43 of the disc spring 40. On the other hand, the right and left side surface portions 27 of the connecting portion 25 are formed with through-holes in positioning holes 35 into which the above-described positioning protrusions 45 are fitted at the center of the depth and at the lower edge. The positioning hole 35 is formed such that its height and frontage are larger than the thickness and width of the positioning protrusion 45, and in particular, the frontage is formed so as to gradually increase toward the inner surface side. This is because the outer peripheral edge 43 of the portion of the disc spring 40 where the positioning protrusion 45 protrudes is allowed to escape, including the natural state and the case where the outer peripheral edge 43 is elastically expanded and expanded as described later.

In other words, on the bottom surface portion 26 of the connecting portion 25, the lateral width is equal to the lateral width of the bottom surface portion 26, that is, a size slightly smaller than the diameter of the outer peripheral edge 43 in the natural state of the disc spring 40, and the depth is A mounting surface 37 of a disc spring 40 is provided that has a rectangular shape slightly larger than the diameter of the outer peripheral edge 43 in the natural state of the spring 40.
And the protrusion part 38 is formed by knocking out from the back surface in the position of the four corners of the mounting surface 37, and the position spaced apart from the outer periphery 43 of the disk spring 40 in a natural state with a slight clearance. The gap is of such a size that the outer peripheral edge 43 does not interfere with the protrusion 38 when the disc spring 40 is normally flattened. The protrusion 38 has, for example, a shape that forms a part of a sphere, and the height of the protrusion 38 is slightly lower than the height when the disc spring 40 is normally flattened.

  When the disc spring 40 is mounted, as shown in FIG. 1, in the process before the connection portion 25 in the middle of manufacturing the female terminal 20 is assembled, the outer surface is placed at the center of the mounting surface 37 set on the bottom surface portion 26. The positioning 43 is placed in a posture in which the peripheral edge 43 is directed downward and the positioning protrusions 45 are aligned with the positioning holes 35. Subsequently, as described above, when the plate portion 24 is bent and the connection portion 25 is formed, the disc spring 40 has its outer peripheral edge 43 placed on the mounting surface 37, and the left and right positioning protrusions 45 are It is mounted in the connecting portion 25 in a state of being fitted in the positioning hole 35 of the side surface portion 27 and prevented from being displaced. Accordingly, an insertion space S of the tab 13 is formed between the inner peripheral edge 42 (top surface) of the disc spring 40 in the free state and the contact portion 33, and the height dimension of the insertion space S is set to be the height of the tab 13. It is set to be smaller than the thickness by a predetermined amount.

Next, the operation of this embodiment will be described.
When the male and female terminal fittings 20 and 10 are connected, the tab 13 of the male terminal 10 is inserted from the front into the connecting portion 25 of the corresponding female terminal 20 as shown in FIG. The inserted tab 13 is guided by the tapered portion 33A at the front end of the contact portion 33 or the inclined surface on the front side of the disc spring 40, and is guided to the insertion space S between the top surface of the disc spring 40 and the contact portion 33, The disc spring 40 is pushed in while being flattened. As shown in FIG. 9, when the tab 13 is inserted to a predetermined position, the contact portions 33 formed on the top surface portions 28 of the connection portion 25 are restored by the restoring elasticity of the flat spring 40 that is elastically compressed. The male and female terminal fittings 20 and 10 are electrically connected to each other.

When the disc spring 40 is used as the spring member so as to elastically press the tab 13 toward the contact portion 33 as described above, the spring characteristic of the disc spring 40 accompanying the insertion of the tab 13, that is, load-displacement (deflection). The characteristic indicates a non-linear characteristic having a region a in which the spring constant is close to 0 in the middle of the displacement range, as indicated by a characteristic line I in FIG.
Accordingly, when setting the displacement of the disc spring 40 in order to obtain the optimum contact load A (N), if the above-described spring constant is set to a0 (mm) which is an intermediate position in the range close to 0, the disc As long as the displacement of the spring 40 varies within the range a in which the spring constant is close to 0, that is, within a range where the displacement is a1 (mm) to a2 (mm), a substantially optimum contact load A (N) is obtained. Can do.
Therefore, an appropriate contact pressure can be obtained even when the disc spring 40 has a variation in displacement when the tab 13 of the male terminal 10 is inserted into the connection portion 25 of the female terminal 20 due to manufacturing errors or the like. High electrical reliability can be obtained, and at the same time, moderate insertion resistance is received, and good connection workability can be obtained.

  Here, when the tab 13 of the male terminal 10 is inserted into the connecting portion 25 of the female terminal 20, as shown in FIG. 13b). If the tab 13a swings forward, the distal end side of the tab 13a hits the left and right protrusions 38. On the other hand, if it swings forward, the position of the tab 13b from the distal end toward the proximal end is shifted to the front left and right sides. Further contact with the projecting portion 38 restricts further deflection (vertical twisting), and as a result, the disc spring 40 is prevented from being excessively bent and deformed.

  Also, as shown in FIG. 10, the tab 13 is inserted in a posture rotated by the clockwise direction (reference numeral 13c) or viewed counterclockwise (reference numeral 13d) as viewed from the front centering on the axis. Then, the right edge of the tab 13c hits the front and rear protrusions 38 on the right side when viewed from the front, or the left edge of the tab 13d hits the front and rear protrusions 38 on the left side. And the disc spring 40 is prevented from being excessively bent and deformed.

Thus, by providing the protrusions 38 at the four corners of the mounting surface 37, all the twists of the vertical twist in which the tab 13 swings upward or downward and the lateral twist in which the tab 13 rotates about the axis line are provided. The amount of twisting can be regulated corresponding to the operation. Therefore, the disc spring 40 is prevented from being excessively bent and displaced to be plastically deformed, so that an appropriate contact pressure can be obtained.
Further, the four corners of the mounting surface 37 become dead spaces when the circular disc spring 40 is mounted, so that the connection portion 25 can be accommodated without causing an increase in size.

<Embodiment 2>
FIG. 12 shows a second embodiment. In the second embodiment, the disc spring is changed to elastically press the tab 13 toward the contact portion 33.
The disc spring 50 according to the second embodiment is a series disc spring 50 formed by abutting and joining two disc springs 40 shown in the first embodiment with the outer peripheral edges 43 abutting each other. Specifically, the two disc springs 40 are joined by spot welding at a plurality of locations where the outer peripheral edges 43 are overlapped with the positioning protrusions 45 aligned, and at an appropriate angular interval. .

When the series disc spring 50 is used instead of the disc spring 40 of the first embodiment, the spring characteristic, that is, the load-displacement characteristic of the series disc spring 50 that accompanies the insertion of the tab 13 is also shown by the characteristic line II in FIG. Shows the nonlinear characteristics. The series disc spring 50 has an advantage that the displacement is larger than that of the single disc spring 40. As a result, the load-displacement characteristic of the series disc spring 50 is compared with the same characteristic of the disc spring 40 of the first embodiment. In addition to the fact that the spring constant becomes smaller as a whole, the region b where the spring constant is close to zero becomes non-linear characteristics.
Therefore, when setting the displacement of the series disc spring 50 in order to obtain the optimum contact load A (N), if the spring constant described above is set to b0 (mm) which is an intermediate position in the range close to 0, It is possible to obtain the optimum contact load A (N) by absorbing variations in displacement over a wider range.

  Further, by similarly forming protrusions 38 at the four corners of the mounting surface 37 of the series disc spring 50, the amount of twisting can be adjusted in correspondence with all the twisting operations of the tab 13 such as the longitudinal and lateral twisting. It is possible to prevent the series disc spring 50 from being excessively bent and displaced.

<Embodiment 3>
Regarding the load-displacement characteristic, as a spring member having a non-linear characteristic having a region in which the spring constant is close to 0 in the middle of the displacement range, as shown in FIG. A dome-shaped spring 60 formed so as to bulge as described above can be mentioned.
Even when such a dome-shaped spring 60 is used, the protrusions 38 are similarly formed at the four corners of the mounting surface, thereby supporting all the twisting operations of the tab 13 such as the longitudinal and lateral twisting. Therefore, it is possible to restrict the amount of twisting and prevent the dome-shaped spring 60 from being excessively bent and displaced.

<Embodiment 4>
FIG. 14 shows a fourth embodiment of the present invention. In the female terminal 20A of the fourth embodiment, the length of the connecting portion 25A is slightly larger than that of the female terminal 20 shown in the first embodiment. On both the front and rear sides of the position where the disc spring 40 having the same size as 1 is mounted, the protrusions 39 extending substantially over the entire width are formed by knocking out.

  In the female terminal 20A of the fourth embodiment, when the tab 13 of the male terminal 10 is inserted into the connection portion 25A, the tab 13 is inserted when the tab 13 is inserted while being swung into a forward or downward posture. When the tip side of the stub is in contact with the ridge 39 on the back side, or the position close to the base end side from the tip of the tab 13 hits the ridge 39 on the near side, further deflection (vertical twisting) is regulated, The disc spring 40 is prevented from being excessively bent and deformed.

  Further, when the tab 13 is inserted in a posture rotated clockwise or counterclockwise about the axis, the right edge of the tab 13 hits the right end of the front and rear protrusions 39 or the left edge of the tab 13 , When it hits the left end of the front and rear ridges 39, further rotation (lateral twist) is restricted, and similarly, the disc spring 40 is prevented from being excessively bent and deformed.

<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 Embodiment 1, the case where the protrusions are provided at the four corners of the mounting surface of the disc spring is illustrated, but the twisting direction of the tab is limited depending on the conditions of the tab insertion direction in the other male terminal. In the case where the protrusions are provided, the locations of the protrusions may be limited such that the protrusions are provided at the left and right two locations on either the front and rear sides, or at the left and right two locations on the left and right sides.
(2) The shape of the protrusion is not limited to the shape that forms part of the sphere illustrated in the first embodiment, and may be formed in an arbitrary shape such as a pyramid or a truncated pyramid.

(3) When a larger contact load is desired for the disc spring, a parallel disc spring in which a plurality of disc springs are stacked in the same direction may be applied.
(4) The non-linear characteristic regarding the load-displacement characteristic shown in the above embodiment is merely an example, and the non-linear characteristic corresponding to the application can be obtained by appropriately changing the material, shape, etc. of the disc spring.

DESCRIPTION OF SYMBOLS 10 ... Male terminal 13 ... Tab 20, 20A ... Female terminal 25, 25A ... Connection part 26, 26A ... Bottom part 27 ... Side part 28 ... Top surface part 33 ... Contact part 35 ... Positioning hole (positioning recessed part)
37 ... Mounting surface 38 ... Projection 39 ... Projection (projection)
40 ... Belleville spring (spring member)
43 ... outer periphery (periphery)
45 ... Positioning protrusion (positioning protrusion)
50 ... Series disc spring (spring member)
60 ... Dome-shaped spring (spring member)

Claims (4)

A rectangular tube-like connection part into which the tab of the mating male terminal is inserted;
A spring member attached to one inner surface of the connection portion, having a shape having a circular peripheral edge whose upper surface bulges, and is elastically displaced with the insertion of the tab, and after the insertion is completed, the tab is connected by the restoring elasticity. And a non-linear characteristic that has a region in which the spring constant is close to zero in the middle of the displacement range with respect to the load-displacement characteristic,
A protrusion that is provided on the inner surface of the connecting portion and that abuts against the tab when the inserted tab is twisted, and regulates the amount of twist;
A female terminal characterized by comprising: A mounting surface of the spring member having a rectangular shape is provided on the one inner surface of the connection portion, and the protrusion is provided at a corner of the mounting surface and on the side of the peripheral edge of the spring member. The female terminal according to claim 1. The female terminal according to claim 2, wherein the protrusions are provided at four corners of the mounting surface. A pair of positioning protrusions are formed on the peripheral edge of the spring member with an interval of 180 degrees, and the inner surface of the connecting portion adjacent to the mounting surface of the spring member and facing each other is positioned on the positioning member. 4. The female terminal according to claim 2, wherein a positioning recess into which the protrusion fits is formed.

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