JP5257671B2 - Terminal fittings and connection structure between wires and terminal fittings - Google Patents

Description

  The present invention relates to a terminal fitting and a connection structure between an electric wire and a terminal fitting.

Conventionally, as a connection structure between an electric wire and a terminal fitting connected to the terminal, for example, a structure described in Patent Document 1 is known. Such a connection structure is a structure in which the end of the exposed core wire in the covered electric wire is crimped so as to be held by the wire crimping portion. Thereby, the exposed core wire and the electric wire crimping part are electrically connected. As described in Patent Document 1, a plurality of terminal fittings connected to an electric wire with such a connection structure are housed and used inside a synthetic resin housing. Further, a rubber plug may be attached to the end of each terminal fitting, and the space between each terminal fitting and the rear end of the housing is sealed in a watertight state.
JP 2002-31396 A

  By the way, in general, an oxide film may be formed on the surface of the core wire of the electric wire in combination with oxygen or moisture in the air. If the wire crimping portion is crimped in this state, an oxide film is interposed between the core wire and the wire crimping portion, and there is a concern that the contact resistance between the core wire and the wire crimping portion may increase due to this. . In particular, when the covered electric wire is an aluminum electric wire, there is a situation that an oxide film is easily formed firmly. In order to break such an oxide film, the wire crimping portion may be pressed strongly against the oxide coating by crimping the wire crimping portion with high compression. However, when crimping with high compression is performed, as a result of the crimped wire crimping portion extending in the longitudinal direction, the dimension of the longitudinal direction of the terminal fitting as a whole may be longer than a predetermined dimension.

If the length of the terminal fitting in the longitudinal direction is long, there is a concern that the terminal fitting may protrude from the housing when housed in the housing. As a result, the creepage distance between the terminal fittings accommodated adjacent to each other in the housing is reduced, causing a leak. Moreover, when using a rubber stopper, as a result that the position will shift | deviate with respect to a housing, sufficient sealing performance may not be ensured.
The present invention has been completed based on the above circumstances, and its purpose is to eliminate the influence of the oxide film as much as possible and to reduce the contact resistance between the core wire and the terminal metal fitting. And providing a connection structure between the electric wire and the terminal fitting.

The present invention is a connection structure between an electric wire obtained by coating an insulating coating on a core wire and a terminal fitting provided with a counterpart connection portion connected to the counterpart device, and the core wire is exposed at the tip of the electric wire. In addition, a tab portion is formed at the exposed tip of the core wire, and the terminal fitting is provided with a base portion integrally extending from the mating connection portion and one side edge of the base portion. Formed by bending the front end of the provided plate piece, the core wire pressing part facing the base part through a gap through which the tab part can be inserted , and both ends in the longitudinal direction by striking the base part together with the base part Thickness dimensions of the tab portion of the electric wire projecting toward the core wire pressing portion in the form of a two-sided mountain shape that is integrally connected and contacting the core wire pressing portion or between the core wire pressing portions facing the contact protruding at narrower intervals than the base Embracing the core pressing auxiliary portion formed by bending the tip of the extending from the other side edge plate piece so as to overlap the outside of the core pressing portion, the insulating coating is provided integrally with the base portion And an insulation barrel for fixing the electric wire.

When the tab portion of the core wire is pushed between the base portion and the core wire pressing portion, the tab portion is slid with respect to both the contact protrusion and the core wire pressing portion . As a result, the oxide film formed on the surface of the tab portion is scraped off, and the metal surface appears. As a result of the contact between the metal surface, the contact protrusion and the core wire pressing portion , the contact resistance between the electric wire and the terminal fitting can be reduced, and the electrical performance can be enhanced.
That is, it is not necessary to caulk the terminal fitting with high pressure in order to break the oxide film. For this reason, the extension of the terminal metal fitting which can occur by caulking with high pressure can be prevented, and the terminal metal fitting can be used with a predetermined dimension.

Further, by providing the core wire pressing auxiliary portion , when the tab portion is pushed between the contact protrusion and the core wire pressing portion , deformation of the core wire pressing portion to the outside is restricted. As a result, the tab portion is sandwiched at a higher pressure and rubbed strongly from the contact protrusion and the core wire pressing portion , so that the oxide film can be effectively removed.

The core wire may be made of aluminum or an aluminum alloy . If it does in this way, it will become especially useful about the aluminum electric wire which has the characteristic that an oxide film is easy to be formed.

  According to the present invention, the influence of the oxide film can be eliminated as much as possible, and the contact resistance between the core wire and the terminal fitting can be reduced, so that the electrical performance of the terminal fitting can be enhanced.

<Embodiment>
An embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, an example of a connection structure between an electric wire obtained by coating a core wire with an insulating coating and a terminal fitting provided with a counterpart connection portion connected to a counterpart device is shown.

  FIG. 1 is a side view showing a state where the electric wire and the terminal fitting of the present embodiment are separated. In this embodiment, both are connected by pushing in the front-end | tip of the aluminum electric wire 10 from the one side (right side of FIG. 1) of the terminal metal fitting 20. As shown in FIG. In FIG. 1, a part of the terminal fitting 20 is shown in a sectional view.

  FIG. 2 is a perspective view showing the vicinity of the tip of the aluminum electric wire 10 before the tip is processed. The aluminum electric wire 10 has a structure in which a core wire 11 is covered with an insulating coating 13 made of synthetic resin. The core wire 11 is a single core wire made of aluminum or an aluminum alloy and having a circular cross section. At the tip of the aluminum electric wire 10, the core wire 11 is exposed by peeling off the insulating coating 13.

  FIG. 3 is a perspective view showing the vicinity of the tip of the aluminum electric wire 10 after processing the tip into a tab shape. The tip end of the core wire 11 is a tab portion 14 processed into a flattened tab shape, and the tab portion 14 contacts the terminal fitting 20 to be electrically connected. By bringing the tab portion 14 into contact in this way, the contact area with the terminal fitting 20 can be increased, and the conductivity can be increased.

4 is a plan view showing the terminal fitting 20 of the present embodiment, and FIG. 5 is a cross-sectional view taken along the line AA of FIG.
The terminal fitting 20 is formed by pressing a metal plate excellent in conductivity, for example, a plate material made of a copper alloy and plated with Sn (tin). The terminal fitting 20 is mainly composed of a counterpart connection part 21 provided on one end side (left side in FIG. 4) and a base part 32 provided integrally extending from the counterpart connection part 21.

  The mating side connection portion 21 has an eyeball shape in which a mounting hole 23 is formed. A bolt (not shown) is passed through the mounting hole 23 and attached to the counterpart device (not shown), so that the counterpart device and the terminal fitting 20 are connected.

On the right side of the counterpart connection portion 21 in FIG. 4, a core wire pressing portion 34 disposed to face the base portion 32 is provided.
In the vicinity of the center of the terminal fitting 20 in the longitudinal direction, the core wire pressing portion 34 is extended from the both side edges of the base portion 32 so as to be orthogonal to each other. Then, the core wire pressing portion 34 is formed by bending the tip of the left plate piece 36 </ b> L in FIG. 5 at a right angle toward the inside of the base portion 32.

On the other hand, the tip of the right plate piece 36R in FIG. 5 is a core wire pressing auxiliary portion 37 that is bent at a right angle so as to overlap the core wire pressing portion 34 from the outside. With the above configuration, the base 32, the plate piece 36, the core wire pressing portion 34, and the core wire pressing auxiliary portion 37 are formed so as to form a square tube with a square cross section.
In the present embodiment, the plate piece 36L is an example of “a plate piece extended from one side edge” described in the claims, and the plate piece 36R is described in the claims. It is an example of a “plate piece extended from the other side edge”.

  As shown in FIG. 1, the facing distance “a” between the base portion 32 and the core wire pressing portion 34 is set to be larger than the thickness dimension “b” of the tab portion 14 of the core wire 11. Thus, a gap B through which the tab portion 14 can be inserted is formed between the base portion 32 and the core wire pressing portion 34. Further, the length of the core wire pressing portion 34 in the longitudinal direction is set slightly smaller than the length of the tab portion 14, and the tab portion 14 protrudes from the gap B when the tab portion 14 is inserted into the gap B. (See FIG. 6 described later).

A contact protrusion 38 is formed on the base 32 by protruding from the core wire pressing portion 34. The contact protrusion 38 is formed by knocking out a part of the base 32 from below. For this reason, the contact protrusion 38 has a mountain shape integrally connected to the contact protrusion 38 at both lower ends in the longitudinal direction.
In the present embodiment, the base portion 32 is an example of “one” described in the claims, and the core wire pressing portion 34 is an example of “the other” described in the claims.

  The protruding amount of the contact protrusion 38 is set such that the distance d between the protruding end of the contact protrusion 38 and the core wire pressing portion 34 is narrower than the thickness dimension b of the tab portion 14. Further, in the longitudinal direction (left and right direction in FIG. 1), the contact protrusion 38 is disposed at a position corresponding to the vicinity of the center of the core wire pressing portion 34.

  The length of the contact protrusion 38 in the width direction is set to be slightly larger than the width of the tab portion 14 of the core wire 11. For this reason, in the width direction (left-right direction of FIG. 5), the tab part 14 can be made to contact the contact protrusion 38 over the full length. Thereby, both contact area can be enlarged and electroconductivity can be made high. In FIG. 5, the inserted tab portion 14 is illustrated by a two-dot chain line.

In the terminal fitting 20, an insulation barrel 26 is provided at the end opposite to the counterpart connection portion 21.
The insulation barrel 26 is an open barrel type, and barrel pieces 26 </ b> A are integrally formed from the left and right side edges of the base portion 32. Further, each barrel piece 26 </ b> A is arranged with its position shifted in the longitudinal direction of the terminal fitting 20.

  The insulation barrel 26 is crimped by crimping the end of the insulating coating 13 of the aluminum electric wire 10 so that both barrel pieces 26A can be clamped by holding the outer periphery of the end of the insulating coating 13 from both the left and right sides. It has become.

  The aluminum electric wire 10 and the terminal metal fitting 20 of this embodiment are the above structures, and are connected to the terminal of the aluminum electric wire 10 as follows. FIG. 6 is a side view showing a state in which the aluminum electric wire and the terminal fitting are connected.

  First, from the rear of the terminal fitting 20 (right side in FIG. 6), the tip of the aluminum electric wire 10 is inserted, and the tab portion 14 of the core wire 11 is inserted into the gap B. The inserted tab portion 14 is pushed between the contact protrusion 38 and the core wire pressing portion 34. As described above, since the distance d between the protruding end of the contact protrusion 38 and the core wire pressing portion 34 is set to be smaller than the thickness dimension b of the tab portion 14, the contact protrusion 38 and the core wire pressing portion 34. As a result, the tab portion 14 pushed in between the contact projection 34 and the core wire pressing portion 34 passes through the tab 14 so as to increase the distance d between the contact projection 38 and the core wire pressing portion 34. Is slid strongly.

  By the way, the surface of the core wire 11 of the aluminum electric wire 10 is characterized in that an oxide film is easily formed by bonding with oxygen or moisture in the air. When an oxide film is interposed between the core wire 11 and the terminal fitting 20, there is a concern that the contact resistance between the two increases.

  When such an oxide film is formed on the surface of the tab portion 14, the tab portion 14 is strongly slid by both the protruding end of the contact protrusion 38 and the core wire pressing portion 34. Is scraped off and the metal surface appears. For this reason, the appearing metal surface comes into contact with the contact protrusion 38 and the core wire pressing portion 34. As a result, the contact resistance between the electric wire and the terminal fitting can be reduced, and the electrical performance can be enhanced.

  In this way, when the aluminum wire 10 is pushed in while the tab portion 14 is slid and the insulating coating 13 reaches a position corresponding to the insulation barrel 26, the pushing operation of the aluminum wire 10 is completed.

  Next, both the barrel pieces 26 </ b> A are crimped to the insulating coating 13 by pressing between the anvil and the crimper installed in the crimping device (not shown). Thereby, the aluminum electric wire 10 is fixed to the terminal fitting 20. The connection work of the terminal fitting 20 to the aluminum electric wire 10 is completed by the above work.

  As described above, according to the present embodiment, the tab portion 14 is pushed between the protruding end of the contact protrusion 38 and the core wire pressing portion 34, thereby strongly against the contact protrusion 38 and the core wire pressing portion 34. It was set as the structure made to slide. As a result, the oxide film formed on the surface of the tab portion 14 is scraped off, and the metal surface appears. As a result of the contact between the metal surface and the contact protrusion 38, the contact resistance between the aluminum electric wire 10 and the terminal fitting 20 can be reduced, and the electrical performance can be improved.

If it is the structure of this embodiment, in order to fracture | rupture an oxide film, it is not necessary to crimp the terminal metal fitting 20 with a high pressure. For this reason, the extension of the terminal metal fitting 20 which can occur by caulking with high pressure can be prevented, and the terminal metal fitting 20 can be used with a predetermined dimension.
For this reason, when accommodating and using the some terminal metal fitting 20 in a housing (not shown), it can prevent that each terminal metal fitting 20 protrudes from the rear part of a housing. Thereby, it is possible to prevent the creepage distance between the terminal fittings 20 from being reduced, and to suppress leakage. Further, when a rubber plug (not shown) is attached to the end portion of the terminal fitting 20 and accommodated in the housing, it is possible to prevent the mounting position of the rubber plug with respect to the housing from being shifted, so that the sealing performance is impaired. Absent.

  In the present embodiment, since the core wire pressing auxiliary portion 37 is provided so as to overlap the outer side of the core wire pressing portion 34, the core wire pressing portion 34 is pressed from the outside by the core wire pressing auxiliary portion 37. Accordingly, when the tab portion 14 passes between the contact protrusion 38 and the core wire pressing portion 34, the core wire pressing portion 34 is restricted from being deformed outward. As a result, the tab portion 14 is sandwiched between the contact protrusion 38 and the core wire pressing portion 34 with higher pressure and rubbed strongly, so that the oxide film on the tab portion 14 can be effectively removed.

  Moreover, in this embodiment, the core wire 11 of the covered electric wire is formed from aluminum or an aluminum alloy. For the aluminum electric wire 10 having a characteristic that an oxide film can be easily formed, a structure that can be broken without caulking the oxide film is particularly effective.

<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 the above embodiment, the configuration in which the distance d is provided between the protruding end of the contact protrusion 38 and the core wire pressing portion 34 is illustrated, but the protruding end of the contact protrusion 38 and the core wire pressing portion 34 are in contact with each other. You may do it. In this case, the tab portion 14 may be pushed into the contact portion between the protruding end of the contact protrusion 38 and the core wire pressing portion 34 so as to expand both.

(2) In the above embodiment, the terminal fitting having the eyeball-like mating connection portion 21 is exemplified as the terminal fitting 20, but for example, a terminal fitting having a tab-shaped mating connection portion may be used.

(3) In the said embodiment, although the aluminum electric wire 10 was illustrated as an electric wire, it is possible to apply also about other electric wires, such as a copper electric wire, in addition to this.

The side view which shows the state which the electric wire and the terminal metal fitting isolate | separated. Perspective view showing the vicinity of the tip of the aluminum wire before processing the tip Perspective view showing the vicinity of the tip of an aluminum electric wire after processing the tip into a tab shape The top view which shows a terminal metal fitting. Sectional drawing cut | disconnected by the AA line of FIG. Side view showing the state where the aluminum wire and the terminal fitting are connected

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Aluminum electric wire 11 ... Core wire 13 ... Insulation film 14 ... Tab part 20 ... Terminal metal fitting 21 ... Mating side connection part 26 ... Insulation barrel 32 ... Base 34 ... Core wire holding | suppressing part 36L ... It extends from one side edge of a base Plate piece 36R ... Plate piece extended from the other side edge of the base portion 37 ... Core wire pressing auxiliary portion 38 ... Contact projection d ... Spacing B ... Air gap

Claims (3)

It is a connection structure between an electric wire formed by coating an insulating coating on a core wire and a terminal fitting having a counterpart connection portion connected to a counterpart device,
At the tip of the electric wire, the core wire is exposed, and a tab portion is formed at the tip of the exposed core wire,
In the terminal fitting,
A base provided integrally extending from the counterpart connection part;
A core wire pressing portion that is formed by bending the tip of a plate piece that is extended from one side edge of the base portion and that faces the base portion with a gap that can be inserted through the tab portion;
By knocking out the base portion, both ends in the longitudinal direction are projectingly provided toward the core wire pressing portion in a double-ended chevron shape integrally connected to the base portion , and the core wire pressing portion is contacted or concentric. a contact projection opposed closely spaced than the thickness of the tab portion of the wire between the parts,
A core wire pressing auxiliary portion formed by bending the tip of a plate piece extending from the other side edge of the base portion so as to overlap the outside of the core wire pressing portion;
A connection structure between an electric wire and a terminal fitting provided with an insulation barrel provided integrally with the base and holding the insulating coating to fix the electric wire. The connection structure between the electric wire and the terminal fitting according to claim 1 , wherein the core wire is made of aluminum or an aluminum alloy. The terminal fitting is connected to an electric wire formed by coating the core wire with an insulating coating, and is provided with a mating side connection portion connected to the mating device,
At the tip of the electric wire, the core wire is exposed, and a tab portion is formed at the tip of the exposed core wire,
The terminal fitting is
A base provided integrally extending from the counterpart connection part;
A core wire pressing portion that is formed by bending the tip of a plate piece that is extended from one side edge of the base portion and that faces the base portion with a gap that can be inserted through the tab portion;
By knocking out the base portion, both ends in the longitudinal direction are projectingly provided toward the core wire pressing portion in a double-ended chevron shape integrally connected to the base portion , and the core wire pressing portion is contacted or concentric. a contact projection opposed closely spaced than the thickness of the tab portion of the wire between the parts,
A core wire pressing auxiliary portion formed by bending the tip of a plate piece extending from the other side edge of the base portion so as to overlap the outside of the core wire pressing portion;
An insulation barrel provided integrally with the base and holding the insulating coating and fixing the electric wire.

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