This application is the United States National Phase of International Patent Application Number PCT/JP2012/076498 filed on 12 Oct. 2012 which claims priority to Japanese Patent Application No. 2011-227128 filed on 14 Oct. 2011, all of which said applications are herein incorporated by reference in their entirety.
The present invention relates to a terminal where an electrical wire or the like is pressed into a U-shaped insertion groove, to be connected in relay connection of a censor or the like.
There have hitherto been provided a variety of terminals to be pressure-welded with an electrical wire, for use in a connector to connect the electrical wire.
Examples of such terminals include a terminal 103 in which an electrical wire 6 is pressed into an insertion part 102 provided with a U-shaped insertion groove 101 shown in
As a terminal having the above configuration, a pressure-welding connector terminal, which is connected with an electrical wire via an insertion part provided with a U-shaped slit similarly to the above, is described in Japanese Unexamined Patent Publication No. H9-312106.
However, in the terminal described in this publication, the U-shaped slit is just provided in a platy insertion part, and the insertion part is thus apt to be plastically deformed when an electrical wire is pressed into the U-shaped slit, thus leading to deterioration in force of holding the electrical wire. There has thus been a problem of poor repairability at the time of reinserting and using the electrical wire.
Further, when the strength of the insertion part is enhanced for ensuring predetermined force of holding the electrical wire, spring force of the insertion part needs increasing, thus causing a problem of making the U-shaped slit difficult for pressing-in of the electrical wire.
The present invention has been made in view of the above conventional problems, and provides a terminal which does not require a large amount of applied load at the time of pressing-in of an electrical wire and can avoid plastic deformation that occurs by the pressing-in of the electrical wire, thus ensuring the repairability at the time when the electrical wire is pulled out of an insertion groove and reinserted thereinto to be used.
The invention provides a terminal including an insertion groove for pressing a conductor thereinto disposed between a pair of conductive arm parts, and a slit disposed proximate to the insertion groove
Hereinafter, embodiments of the terminal according to the present invention will be described in accordance with
In a First Embodiment, as shown in
Specifically, as shown in
Next, an operation of pressing the electrical wire 6 into the insertion groove 13 will be described with reference to
The electrical wire 6 has a twisted line 8 bundling a plurality of single lines 7, and a coated layer 9 made up of a resin coating a periphery of this twisted line 8. Upon pressing-in of the electrical wire 6 from the upper portion of the insertion part 12, first, the coated layer 9 is removed by the peeling part 15 and the twisted line 8 is exposed.
When the electrical wire 6 is further pressed downward in the insertion groove 13, the twisted line 8 is guided downward while expanding the conductive arm part 14 obliquely downward by a load W1 (see FIG. 2(B)), and by reaction force thereof, the single line 7 begins to be deformed. Further, a load W2 is applied obliquely downward to each end of the end 18 of the insertion groove 13. However, with the slit 17 provided in the present invention, stress W3 generated in the base 16 is dispersed via the slit 17, making the base 16 of the insertion groove 13 apt to be elastically deformed. Hence it is possible to prevent stress concentration on a specific place of the insertion part 12, so as to reduce plastic deformation. Accordingly, even when the electrical wire 6 is once pulled out of the insertion groove 13 and reinserted thereinto, the holding force does not decrease, and the repairability can be held.
Then, the twisted line 8 pressed into the insertion groove 13 is pushed thereinto with the single lines 7 in the state of being undone from the bundle and densely provided within the insertion groove 13 (see
The present inventors conducted analysis of applying a load to each of the insertion part 12 according to the present invention and the conventional insertion part shown in
According to the present analysis results, the inclination at the time of elastic deformation is small in the insertion part 12 of the present invention as compared with the conventional insertion part. Namely, it is found that the insertion part 12 of the present invention is apt to be elastically deformed and is not apt to be plastically deformed. Therefore, when the electrical wire 6 is pulled out in a state where the displacement of each insertion part has reached β, the insertion part 12 of the present invention gets back into the original shape along a straight line A. On the other hand, in the conventional insertion part, it gets back along a straight line (B). Hence it was confirmed that the insertion part 12 of the present invention can reduce plastic deformation and ensure the repairability.
Further, it is found that, when the insertion part 12 of the present invention and the conventional insertion part are to be displaced in the same amount, the insertion part 12 of the present invention is displaced by a small load as compared with the conventional insertion part. It was thus found that the load required at the time of pressing the electrical wire 6 into the insertion groove 13 becomes small, and the electrical wire 6 becomes easy for pressing-in.
As shown in
It is to be noted that in the present embodiment, although the insertion part 12 as a separate body is fitted to the end of the conductive part 21, the insertion part 12 and the conductive part 21 may be provided in a unified manner (see
Further, as shown in
Naturally, the insertion part of the present invention is not restricted to the above embodiment, and a variety of shapes can be adopted so long as the slit is provided in at least some part around the insertion groove.
A modified example of the First Embodiment is a case where, in place of the arc-like slit 17, a linear slit 498 is provided which extends in a horizontal direction and each end of which is formed in a semicircular shape, as shown in
A second Embodiment is a case where a substantially U-shaped slit 27 (first slit) is provided which surrounds the end 18 of the insertion groove 13 and extends on both sides of the insertion groove 13, as shown in
A modified example of the Second Embodiment is a case where a linear slit (second slit) 29, whose end is formed in a semicircular shape, is provided on the outer side of the substantially U-shaped slit 27 along the outer shape of a conductive arm part 14, as shown in
A third Embodiment is a case where the insertion part 31 is provided with: a conductive arm part 33; a peeling part 35; and a reinforcing part 36 which is provided between the conductive arm part 33 and the end of the peeling part 35, as shown in
X represents a distance from the center (force point) of the contact part between the conductive arm part 33 and the electrical wire 6 to the inside of an insertion groove 34 at the time of pressing-in of the electrical wire 6, Y represents a width of the conductive arm part 33 at the point reached by moving just the distance X, and Z represents a section modulus at a point of the distance X. At this time, as for the conductive arm part 33, the width Y of the conductive arm part 33 is decided such that the section modulus Z is proportional to the distance X, namely a width Y2 is proportional to the distance X. Accordingly, even when the electrical wire 6 is pressed into the insertion groove 34, stress a generated throughout the conductive arm part 33 is constant, and hence the stress a is not biased to a specific place of the conductive arm part 33. Hence it is possible to reduce plastic deformation and plastic distortion that occur in the conductive arm part 33, while reducing a decrease in holding force due to exhaustion even when the electrical wire is once pulled out of the insertion groove 34 and reinserted thereinto, so as to hold the repairability. Further, the shape of the conductive arm part 33 is simplified, thereby facilitating production of the terminal and allowing reduction in production cost thereof.
It is to be noted that the shape of the conductive arm part 33 is not restricted to that of the beam with uniform strength, and it may be a shape approximate to that of the beam with uniform strength. Further, when t represents a distance from the force point to an end 34a of the conductive arm part 33 and h represents the maximum width at a fulcrum provided at the end 34a of the conductive arm part 33, the following formula holds.
when X=(½)×t, at a point of X,Y=(h/√2)×(0.8 to 1.2).
At this time, stress that is applied to the conductive arm part 33 can be efficiently dispersed.
Further, a modified example of the Third Embodiment is a case where an inclined surface 37 which is inclined parallel to the end surface of the peeling part 35 is formed on the peeling part 35 of the insertion part 31, as shown in
A fourth Embodiment is a case where a long slit 44 is provided in the vicinity of the insertion groove 34 of a conductive arm part 42 and a short slit 45 is provided on the outer side of this slit 44 along the outer shape of the conductive arm part 42, as shown in
A fifth Embodiment is a case where a substantially U-shaped slit (first slit) 53, which extends along the insertion groove 34 and surrounds the end 26 of the insertion groove 34, is provided in a conductive arm part 52 of an insertion part 51, as shown in
On the other hand, the conventional insertion part gets back into the original shape along a straight line B. Since the insertion part 51 of the present embodiment is apt to be elastically deformed and is significantly reduced in plastic distortion, it was confirmed that the repairability can be reliably held.
As a sixth Embodiment, an arc-like notched part 30 with an angle α over 180° is provided at the end 18 of the insertion groove 13, as shown in
A seventh Embodiment is a case where an insertion part 91 is provided with an arc-like notched part 93 formed at an end 92a of an insertion groove 92; a substantially U-shaped slit 94 surrounding this arc-like notched part 93 and extending along the insertion groove 92; and a substantially triangular through hole (slit) 97, as shown in
Further, a pair of pressing-in notches 99 may be formed in positions (contact parts 92b with the electric wire 6) opposed to the insertion groove 92, as in the Eighth Embodiment shown in
The present inventors conducted analysis of reaction force from each of the electric wire 6 distributed to points, F, F′, G, G′, H, H′, I, I′, J and J′ of the pressing-in notch 99.
Although the insertion part 12 has been applied to the terminal 11 for use in the connector 1 to connect the electrical wire 6 in the above embodiment, this is not restrictive.
For example, as in a Ninth Embodiment shown in
This insertion part 72 is provided with an insertion groove 73 for inserting an extension card, and a pair of conductive arm parts 74 symmetrically formed with this insertion groove 73 provided therebetween. Since a bow-shaped slit 76 is provided in a base 75 in this insertion part 72, a similar effect can be obtained.
A modified example of the Ninth Embodiment is a case where the insertion groove 73 is formed into a substantially oval shape and the conductive arm part 74 is formed into such a shape as to be approximate to the shape of the beam with uniform strength, as shown in
On the other hand, as in a Tenth Embodiment shown in
This insertion part 82 is provided with: an insertion groove 83 for inserting a flexible print substrate thereinto (not shown); a fixed piece 84 which extends below the insertion groove 83 and is fixed to a housing (not shown); and a conductive arm part 85 opposed to the fixed piece 84 with the insertion groove 83 provided therebetween. Then, an arc-shaped slit 87 curved so as to surround an end 88 is provided in a base 86 of the insertion groove 83.
Moreover, as a modified example of the Tenth Embodiment, as shown in
As described, the present invention provides a terminal in which an insertion groove for pressing a conductor thereinto is provided between a pair of conductive arm parts, wherein a slit is provided in at least some part around the insertion groove.
With the above configuration, stress generated in the conductive arm part can be dispersed via the slit, and the conductive arm part becomes apt to be elastically deformed. Hence it is possible to prevent stress concentration on a specific place of the terminal, so as to reduce plastic deformation. Accordingly, even when a conductor is once pulled out of the insertion groove and reinserted thereinto, the holding force does not decrease, and the repairability can be held. Further, the conductive arm part becomes apt to be elastically deformed, thereby facilitating pressing-in of the conductor and a connection operation.
The slit may be provided on each side of the insertion groove.
Further, the slit may be a substantially triangular through hole, and a distance from the insertion groove to one side of the through hole may increase sequentially along a direction from the center of a contact part between the conductive arm part and the conductor toward the end at the time of pressing-in of the conductor.
With the above configuration, stress generated in the conductive arm part further becomes constant, and hence plastic deformation is not apt to occur, leading to improvement in repairability.
When X represents a distance from the center of the contact part toward the end and Z represents a section modulus of the conductive arm part at a point of the distance X, Z may be proportional to X.
Therefore, stress that is acted on the cross section at the point of the distance X becomes constant, thereby to allow prevention of plastic deformation.
A plurality of slits may be juxtaposed such that the slit provided in a position closest to the insertion groove has the maximal length and the slits sequentially have smaller lengths as being more distant from the insertion groove.
Accordingly, stress generated in the conductive arm part can be made constant.
A slit may be provided on the deeper side than the end.
Therefore, stress generated in a base of the conductive arm part is dispersed by means of the slit, making the conductive arm part apt to be elastically deformed. Hence it is possible to prevent stress concentration on the base, so as to reduce plastic deformation.
The slit may be a substantially U-shaped first slit surrounding the end of the insertion groove and extending along the insertion groove.
This facilitates elastic deformation of the conductive arm part to reduce the plastic deformation that occurs at the time of applying a load to an opening of the insertion groove, while allowing dispersion of stress that concentrates on the end of the insertion groove.
A second slit may be provided between the outer edge of the conductive arm part and the first slit.
This can further facilitate elastic deformation.
A third slit may be provided on the opposite side to the end of the first slit.
Therefore, stress generated in the base can further be dispersed by means of the slit, making the conductive arm part apt to be elastically deformed.
A notched part with a width larger than a width of the insertion groove may be provided at the end of the insertion groove.
Therefore, by application of a load, force of a vertical component and vertical force generated by the load cancel each other, out of a horizontal component and the vertical component of force generated at each end of the notched part, and hence it is possible to prevent stress concentration at the end of the insertion groove.
A pressing-in notch for pressing and fixing the conductor thereinto may be formed on at least one side of the insertion groove.
Therefore, reaction force by the pressed/fixed conductor is uniformly distributed to the pressing-in notch.
A pair of pressing-in notches for pressing and fixing the conductor thereinto may be formed in opposed positions of the insertion grooves.
Therefore, reaction force by the pressed/fixed conductor is uniformly distributed to the pressing-in notch.
The pressing-in notch may be an arc curved outward.
Therefore, reaction force by the conductor is uniformly distributed to the pressing-in notch in a more reliable manner.
Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.
Number | Date | Country | Kind |
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2011-227128 | Oct 2011 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2012/076498 | 10/12/2012 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2013/054909 | 4/18/2013 | WO | A |
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A European Search Report from the corresponding European Patent Application No. 12840322.7 issued on May 7, 2015. |
International Search Report for corresponding application PCT/JP2012/076499 filed Oct. 12, 2012; Mail date Jan. 8, 2013. |
International Search Report for corresponding application PCT/JP2012/076497 filed Oct. 12, 2012; Mail date Jan. 8, 2013. |
International Search Report for corresponding application PCT/JP2012/076498 filed Oct. 12, 2012; Mail date Jan. 15, 2013. |
Number | Date | Country | |
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20140315449 A1 | Oct 2014 | US |