JP4548190B2 - Terminal fitting - Google Patents

Description

  The present invention relates to a terminal fitting.

Among the terminal fittings, the one described in Patent Document 1 includes a cylindrical main body part into which a tab can be inserted from the front, and a substantially mountain-shaped elastic contact piece as viewed from the side is arranged in the main body part. ing. Both ends of the elastic contact piece are free ends, and protrusions project from the free ends toward the inner surface of the substrate of the main body. When the tab is inserted into the main body, the elastic contact piece is elastically bent, and the protrusion slides on the inner surface of the substrate.
Japanese Utility Model Publication No. 6-9069

  By the way, in the above case, the contact position between the protrusion of the elastic contact piece and the inner surface of the substrate is in the length direction from when the tab starts to hit the elastic contact piece to when the tab insertion operation is completed. There was a situation that the position was greatly displaced, and the reaction force against the elastic contact piece also fluctuated greatly. Thus, when the fluctuation value of the reaction force is large, it is difficult to obtain stable spring characteristics, and there is a dislike of promoting the deterioration of the elastic contact piece by repeated use.

  The present invention has been completed based on the above circumstances, and an object thereof is to enable an elastic contact piece to maintain a predetermined spring characteristic.

As means for achieving the above object, the invention of claim 1 includes a cylindrical main body part into which a tab can be inserted, and extends into the main body part from the front end of the substrate toward the rear. resilient contact pieces out being deformably disposed deflection, the resilient contact piece has a contact portion with respect to the tub, and the contact portion gradually the substrate side toward therefrom to a free end as a top It is configured to have a rearwardly inclined portion that extends straight so as to approach , and the substrate is formed with a round- shaped receiving portion that protrudes into the main body portion, and when the elastic contact piece is bent and deformed, top of the receiving portion and said rear slanted portion is characterized in was configured to slide on the line contact or point contact in place.

The invention of claim 2 is characterized in that, in the invention of claim 1, the receiving portion is formed in a curved shape by knocking out.
A third aspect of the invention is characterized in that, in the first or second aspect of the invention, a plurality of the receiving portions are provided apart from each other in the width direction on the substrate.

<Invention of Claim 1>
When the tab is inserted into the main body, the elastic contact piece is elastically bent. At this time, since the rearwardly inclined portion of the elastic contact piece and the top of the receiving portion formed on the substrate of the main body portion are in sliding contact with each other in a line contact or point contact manner at a fixed position, the elastic contact piece The variation value of the reaction force can be kept low.
That is, when considering the present invention based on the relational expression established when the cantilever is deformed, the contact position of the contact portion is regarded as a substantially fixed fixed end, and the free end region of the elastic contact piece is defined as a cantilever. Assuming that the length of the line along the range from the contact position of the contact point to the position of sliding contact with the receiving part of the elastic contact piece is S, and the projected length when the line length S is projected on the horizontal axis is L. Then, the reaction force P (free end deflection) to the elastic contact piece is expressed by the following equation: Reaction force P = displacement amount σ × longitudinal elastic coefficient E × cross section secondary moment I × (3 / SL2)
Can be calculated approximately.
Here, when the elastic contact piece is elastically bent along with the tab insertion operation, the line length S is smaller than that before the tab insertion, but the projection length L is that the receiving portion is set at a fixed position. Due to this, the value is kept constant before and after the insertion of the tab. Therefore, if the reaction force P is subtracted before and after the insertion of the tab, the L2 portion is canceled and becomes zero, so that the variation value of the reaction force P can be suppressed lower than in the conventional case where the L2 portion varies greatly. That is why. As a result, a predetermined spring characteristic can be maintained even when the elastic contact piece is repeatedly used.

<Invention of Claim 2>
Since the receiving portion is formed into a curved shape by knocking out, the manufacture becomes easy.
<Invention of Claim 3>
Since a plurality of receiving portions are provided apart from each other in the width direction on the substrate, the free end region of the elastic contact piece is supported in a balanced manner by the plurality of receiving portions in the width direction.

  An embodiment of the present invention will be described with reference to FIGS. The terminal fitting 10 of the present embodiment is a so-called female terminal fitting formed by bending, punching out, or the like, on a metal plate material punched into a predetermined shape, and is elongated in the front-rear direction as a whole. Is a main body portion 20, and a substantially latter half portion is an open barrel-shaped electric wire connecting portion 60, and a terminal portion of an electric wire (not shown) is connected to the electric wire connecting portion 60 so as to be conductive.

  The main body 20 has a rectangular tube shape opened in the front-rear direction. As shown in FIG. 4, as shown in FIG. A pair of side plates 22A and 22B raised substantially at right angles to the right side plate 22B from the entire region at the rising end of the left side plate 22A to the right side plate 22B side substantially parallel to the bottom plate 21. . The front end portion, the rear end portion, and the intermediate portion of the extended end edge (right end edge) of the top plate 23 are in contact with the upper end of the right side plate 22B from above, and the right side of the extended end edge of the top plate 23 As shown in FIG. 5, two front and rear locking plates 24A extending downward (so as to overlap) from the front and rear regions that are not in contact with the upper edge of the plate 22B, as shown in FIG. 24B is formed. The front locking plate 24A has a substantially square shape as a whole, and its lower end edge is located at a substantially central height of the main body portion 20. The rear locking plate 24 </ b> B has a substantially square shape as a whole, and its lower end edge is disposed at a low position in the main body 20. On the other hand, the left side plate 22A has a substantially square front locking hole 25A corresponding to the lower edge of the front locking plate 24A, and a substantially square rear locking hole corresponding to the lower edge of the rear locking plate 24B. 25B is formed through.

  A lance hole 26 is formed in the bottom plate 21 so as to open in a substantially square shape over the entire width region. The lower end edges of the left and right side plates 22A and 22B are configured to face the opening region of the lance hole 26 as shown in FIG. An intrusion restricting portion 27 is formed on the right side plate 22B by bulging out a region corresponding to the lance hole 26 inward (in the width direction center). The intrusion restricting portion 27 has a substantially square shape when viewed from the side, and has a substantially trapezoidal shape when viewed from below.

  As shown in FIG. 3, a retaining portion 28 for locking a lance (not shown) on the connector housing side is formed at the opening front end edge of the lance hole 26. The retaining portion 28 is formed by knocking out the opening front end edge 26 </ b> A of the lance hole 26. The retaining portion 28 is disposed at a position eccentric to the left in the width direction (left-right direction) with respect to the main body portion 20, and the retaining portion 28 and an elastic contact piece 30 to be described later are disposed in the width direction. Concentric arrangement.

  A receiving portion 29 is formed on the bottom plate 21 so as to protrude rearward from the lance hole 26 by being knocked out from below. The receiving portion 29 has a protrusion extending in the width direction from the hole edge of the rear locking hole 25B to the right, and its upper surface (inner surface) has a rounded curved surface when viewed from the side. The receiving portion 29 is visible through the rear locking hole 25B when viewed from the side as shown in FIG. The receiving portion 29 is arranged at a position eccentric to the left in the width direction with respect to the main body portion 20, and the receiving portion 29 and the elastic contact piece 30 are arranged concentrically in the width direction. The free end region of the elastic contact piece 30 can be slidably contacted with the receiving portion 29 in a line contact state in the width direction.

  An elastic contact piece 30 is accommodated in the main body 20. As shown in FIG. 6, the elastic contact piece 30 extends in a cantilevered manner from the front end of the bottom plate 21 in a folded shape and is elongated in the front-rear direction. Specifically, the elastic contact piece 30 includes a substantially semicircular arcuate curved portion 31 connected to the front end of the bottom plate 21, and extending portions 32 </ b> A and 32 </ b> B extending backward from the curved portion 31. The extension portions 32A and 32B are formed to be bent in a substantially chevron shape when viewed from the side, and extend forward from the position continuous with the curved portion 31 diagonally upward and rearward. The rear inclined portion 32B extends substantially straight from the rear end of 32A diagonally downward and rearward, and these are arranged with a gentle gradient. When the elastic contact piece 30 is in a free state where it does not bend and deform, the free end of the elastic contact piece 30 (the rear end of the rearwardly inclined portion 32B) is floated and arranged in a non-contact position with respect to the upper surface of the bottom plate 21, that is, The elastic contact piece 30 is in a cantilever support state at its front end. Further, the elastic contact piece 30 can be bent and deformed in the vertical direction with the turning portion 31 as a fulcrum. When the elastic contact piece 30 is elastically bent downward, the free end region (rearly inclined portion 32B) of the elastic contact piece 30 is retracted. At the same time, it comes into sliding contact with a receiving portion 29 protruding from the upper surface of the bottom plate 21. When the bending operation of the elastic contact piece 30 is completed, the elastic contact piece 30 is supported at the front and rear end sides by the free end region of the elastic contact piece 30 coming into contact with the top of the receiving portion 29.

  The turning portion 31 and the forward inclined portion 32A are arranged in front of the lance hole 26, and the rear end (that is, the highest portion) of the forward inclined portion 32A has a dome-like contact portion by knocking upward. 33 is formed. The rearward inclined portion 32B extends from the opening front end edge 26A of the lance hole 26 to the lower end edge of the rear locking plate 24B, and the front end portion of the rearward inclined portion 32B has a height corresponding to the intrusion restricting portion 27. It is arranged. Further, with respect to the width dimension of the elastic contact piece 30, the curved part 31 and the forward inclined part 32A have substantially the same width dimension, and the front end part and the rear end part of the rear inclined part 32B are substantially the same as the forward inclined part 32A. A region having the same width dimension and excluding the front and rear end portions of the rearwardly inclined portion 32B is a constricted portion 32E that is narrower than the forwardly inclined portion 32A.

  In addition, as shown in FIG. 5, a pair of front and rear projections 34A and 34B are formed on the left and right side edges of the elastic contact piece 30 so as to protrude outward in the width direction. Among these, the front protrusion 34 </ b> A has a bilaterally symmetric shape, and is disposed in the vicinity of the contact portion 33, specifically, slightly forward of the contact portion 33. The front projection 34A is positioned so as to correspond to the lower end edge of the front locking plate 24A and the front locking hole 25A in the front-rear direction, and when the elastic contact piece 30 is in a free state where it is not elastically bent. The upper surface of the right front protrusion 34A is in a non-contact position slightly below the lower edge of the front locking plate 24A, and the upper surface of the left front protrusion 34A is higher than the upper edge of the opening of the front locking hole 25A. Is in a non-contact position slightly below. On the other hand, the rear protrusion 34 </ b> B has a symmetrical shape, and is disposed at the free end (rear end) of the elastic contact piece 30. The rear protrusion 34B is positioned so as to correspond to the lower end edge of the rear locking plate 24B and the rear locking hole 25B in the front-rear direction, and when the elastic contact piece 30 is in a free state where it is not elastically bent, The upper surface of 34B is in a non-contact position slightly below the lower edge of the rear locking plate 24B, and the upper surface of the left rear protrusion 34B is in a non-contact position slightly lower than the upper edge of the opening of the rear locking hole 25B. is there.

  The elastic contact piece 30 is disposed at a position eccentric to the left in the width direction with respect to the main body 20 and the lance. The center in the width direction of the elastic contact piece 30 matches the center in the width direction of the retaining portion 28. As shown in FIG. 3, when the lance hole 26 is viewed from below, the front end side region of the rearward inclined portion 32B of the elastic contact piece 30 is exposed over the entire width thereof. Further, a tab receiving portion 35 is formed on the top plate 23 by knocking downward. The center of the tab receiving portion 35 in the width direction is also concentric with the elastic contact piece 30. A space between the upper surface of the elastic contact piece 30 and the lower surface of the tab receiving portion 35 is a tab entry space 36 for allowing the tab 40 inserted into the main body portion 20 to enter from the front.

  Next, the operation of this embodiment will be described. First, the terminal fitting 10 is inserted into the connector housing (not shown) from the rear. When the terminal fitting 10 is inserted to the proper position, the tip projection of the lance enters the lance hole 26 and locks against the retaining portion 28 from behind, so that the terminal fitting 10 is held in the retaining state. In this state, when the tab 40 is inserted into the main body 20 from the front, the tab 40 comes into contact with the contact portion 33 in the tab entry space 36 as shown in FIG. And the tab receiving portion 35 are elastically sandwiched. Further, when the tab 40 comes into contact with the contact portion 33, the free end region (rearly inclined portion 32B) of the elastic contact piece 30 tilts and comes into contact with the top of the receiving portion 29, and the elastic contact piece 30 is at the front and rear end sides. Supported. When the tab 40 is further advanced, the contact portion 33 is pushed down by the tab 40 and displaced downward, and the free end region of the elastic contact piece 30 rotates or retreats on the top of the receiving portion 29 in a sliding state. After that, when the tab 40 is inserted to the normal position, as shown in FIG. 6C, the free end region of the elastic contact piece 30 takes a substantially horizontal posture, and the tab 40 and the terminal fitting 10 are elastic contact pieces. It is connected so as to be conductive by 30 elastic restoring force.

Next, how much the reaction force P of the elastic contact piece 30 accompanying the contact with the receiving portion 29 changes before and after the insertion of the tab 40 will be considered. Here, the reaction force P is calculated using the following equation that is established when the cantilever is deformed.
Reaction force P = displacement σ × longitudinal elastic modulus E × secondary moment of inertia I × (3 / SL ² )
Note that this relational expression is an expression for calculating the deflection at the free end of the cantilever, and does not correspond exactly to the present embodiment, but in order to easily know the value of the reaction force P This is used because it is effective.

  That is, in order to apply the above-described relational expression to the present embodiment, when the contact position of the contact portion 33 is regarded as a substantially fixed fixed end and the free end region of the elastic contact piece 30 is regarded as a cantilever, Can be regarded as the length along the range from the contact position of the contact portion 33 of the elastic contact piece 30 to the position where the free end region is slidably contacted with the receiving portion 29, and L is the horizontal length S. It can be regarded as the projected length projected on the axis.

For example, as illustrated in FIG. 7, when the elastic contact piece 30 is in a natural state before the tab 40 is inserted, the free end region of the elastic contact piece 30 is inclined with a 45 ° gradient with respect to the horizontal axis. , The along-rail length S becomes √2 with respect to the projection length L of 1, so that 3 / SL ² becomes 3 / √2. After that, when the elastic contact piece 30 is elastically bent and the free end region of the elastic contact piece 30 assumes a substantially horizontal posture, the projected length L remains unchanged, but the line length S decreases to 1. Therefore, 3 / SL ² becomes 3/1. In this case, since the displacement amount σ, the longitudinal elastic modulus E, and the cross-sectional secondary moment I do not change at constant values before and after the insertion of the tab 40, the variation amount of the reaction force P is 3 / SL ² variation amount (3 / 1−3 / √2).

On the other hand, as shown in the reference diagram of FIG. 8, a protrusion 39 protruding downward is formed at the free end of the elastic contact piece 30 so that the elastic contact piece 30 is elastically bent. As a comparative example, the temporary structure 39 is applied so that 39 can slide on the flat upper surface of the bottom plate 21. Then, when the elastic contact piece 30 is in a natural state before the tab 40 is inserted, 3 / SL ² becomes 3 / √2 as described above, but after the tab 40 is inserted, the free end region of the elastic contact piece 30 is When taking a substantially horizontal posture, the projection length L increases to √2 and the line length S also increases to √2, so that 3 / SL ² becomes 3 / 2√2. Therefore, the change amount of the reaction force P depends on the change amount of 3 / SL ² (3 / 2√2−3 / √2).

As a result, it can be seen that the change amount of the reaction force P is suppressed lower in the present embodiment than in the comparative example. In other words, in the case of the present embodiment, the receiving portion 29 is in sliding contact with the free end region of the elastic contact piece 30 in a line contact manner at a fixed position, so that the projection length L is before and after the elastic contact piece 30 is elastically bent. This does not fluctuate, and this is a factor that can reduce the amount of change in the reaction force P as compared with the comparative example that involves fluctuations in the projection length L.
As described above, according to the present embodiment, by suppressing the fluctuation value of the reaction force P to be low, a predetermined spring characteristic can be maintained even when the elastic contact piece 30 is subjected to repeated use.

<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, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the above embodiment, the top is formed on the forward inclined portion side of the elastic contact piece. However, according to the present invention, the top is the boundary between the forward inclined portion and the rear inclined portion of the elastic contact piece. It may be formed in the part, or may be formed on the rear inclined part side.
(2) In the above-described embodiment, the receiving portion is formed to extend in the width direction on the bottom plate. However, according to the present invention, a plurality of receiving portions are arranged apart from each other in the width direction on the bottom plate. Also good. In this case, the plurality of receiving portions may be provided in a range extending over the entire width of the free end region of the elastic contact piece. According to this, when the elastic contact piece is elastically bent, the free end region of the elastic contact piece is supported in a balanced manner in the width direction by the plurality of receiving portions.

(3) According to the above embodiment, when the elastic contact piece is in a free state where the elastic contact piece is not elastically bent, the free end region of the elastic contact piece is arranged in a non-contact state with the receiving portion. According to this, when the elastic contact piece is in a free state, the free end region of the elastic contact piece may be in contact with the top of the receiving portion.
(4) In the above-described embodiment, the receiving portion can be slidably contacted with the free end region of the elastic contact piece in a line contact manner. However, according to the present invention, the receiving portion is a free end of the elastic contact piece. The area may be slidable in a point contact manner.
(5) In the above embodiment, the elastic contact piece is connected to the front end portion of the bottom plate and the receiving portion is formed on the bottom plate. However, according to the present invention, the elastic contact piece is connected to the front end portion of the top plate. The receiving part may be formed on the top plate.

Side view of the terminal fitting of this embodiment Plan view of terminal fitting Bottom view of terminal fitting Front view of terminal fitting Cross section of main unit (A) Side sectional view of the main body (B) Side sectional view when the tab starts to contact the contact portion (C) Side sectional view when the tab is inserted to the normal position (A) Side sectional view of the main body (B) A diagram for explaining the amount of change in the reaction force (A) Side sectional view of the main body of the comparative example (B) A diagram for explaining the amount of change in the reaction force

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Terminal metal fitting 20 ... Main-body part 21 ... Bottom plate (board | substrate)
DESCRIPTION OF SYMBOLS 23 ... Top plate 29 ... Receiving part 30 ... Elastic contact piece 32A ... Forward inclination part 32B ... Back inclination part (free end area | region)
33 ... Contact part 35 ... Tab receiving part 40 ... Tab

Claims (3)

It has a cylindrical main body part into which a tab can be inserted, and in this main body part, an elastic contact piece extending rearward from the front end part of the substrate of the main body part is arranged so as to be able to bend and deform.
The elastic contact piece has a contact portion with respect to the tab, and has a back inclined portion extending straight from the contact portion as a top toward the free end and gradually approaching the substrate side ,
The substrate is formed with a round-shaped receiving portion that protrudes into the main body portion ,
Wherein when the resilient contact piece is resiliently deformed, a terminal fitting and the top of the receiving portion and the rear slanted portion, characterized in that the sliding contact to line contact or point contact in place.   The terminal fitting according to claim 1, wherein the receiving portion is formed in a curved shape by knocking out.   The terminal fitting according to claim 1 or 2, wherein a plurality of the receiving portions are provided apart from each other in the width direction on the substrate.

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