Multiple wire connecting terminal

A relay terminal (10) made of copper or copper alloy and configured to join an aluminum wire (20) and a copper wire (30) by being electrically connected to the aluminum wire (20) and the copper wire (30) includes a first barrel portion (11) to be caulked and crimped to an aluminum core (21) of the aluminum wire (20) made of aluminum or aluminum alloy, which is a metal different from copper or copper alloy constituting the relay terminal (10), a second barrel portion (12) to be caulked and crimped to a copper core (31) of the copper wire (30), a bottom plate (13) configured to link the first barrel portion (11) and the second barrel portion (12), and a projecting portion (41) (water drainage portion (40)) provided on the bottom plate (13) and configured to restrict the intrusion of water from the second barrel portion (12) toward the first barrel portion (11).

TECHNICAL FIELD

The present invention relates to a relay terminal.

BACKGROUND ART

Conventionally, copper wires made of copper or copper alloy having excellent electrical conductivity and strength have been used for a wiring harness wired in a vehicle. A copper terminal made of copper or copper alloy, which is the same type of metal as the copper wire, is crimped and connected to an end of the copper wire, and this copper terminal is connected to a device or the like.

In recent years, the weight of a vehicle has been further reduced to improve fuel economy and aluminum wires using aluminum or aluminum alloy as a conductive material have been used as wires to be arranged in the vehicle for the purpose of weight reduction. Although copper terminals made of copper or copper alloy, which is a different type of metal, are crimped and connected to ends of the aluminum wires in terms of strength and the like, the weight of the entire wiring harness is reduced by using the aluminum wires. Such a technique is known, for example, from Japanese Unexamined Patent Publication No. 2005-174896.

An aluminum wire similar to the above wire is used also for a relay terminal for connecting wires for the purpose of weight reduction in some cases. In such cases, the aluminum wire is connected to the relay terminal made of copper or copper alloy.

However, if a core of a wire and a terminal are formed of different types of metals in connecting the wire and the terminal, it is known that at least one of the two metals is dissolved in the form of ions into water and electrolytic corrosion, in which corrosion proceeds by an electrochemical reaction, occurs particularly when an electrolyte is present on a contact part of the wire and the terminal. In the case of the relay terminal as described above, if water or the like intrudes into one end connected to the aluminum wire from the other end, electrolytic corrosion possibly occurs in a part where the aluminum wire and the relay terminal are connected.

The present invention was completed based on the above situation and an object thereof is to suppress the progress of electrolytic corrosion in a part where different types of metals are connected.

SUMMARY OF THE INVENTION

To achieve the above object, the present invention is directed to a relay terminal made of metal and configured to join a first wire and a second wire by being electrically connected to the first and second wires, including a first barrel portion to be caulked and crimped to a first core made of a metal different from a metal constituting the relay terminal and exposed at an end of the first wire including the first core in such a manner as to embrace the first core from opposite sides; a second barrel portion to be caulked and crimped to a second core exposed at an end of the second wire in such a manner as to embrace the second core from opposite sides; a linking portion configured to link the first and second barrel portions; and a water drainage portion provided on the linking portion and configured to restrict the intrusion of water at least from the second barrel portion toward the first barrel portion.

If the metal constituting the first core and that constituting the first barrel portion are different, electrolytic corrosion may occur in either the first core or the first barrel portion when water adheres over the first core and the first barrel portion.

According to the above configuration, the intrusion of water along the linking portion from the second barrel portion toward the first barrel portion can be restricted by the water drainage portion. This can suppress the progress of electrolytic corrosion by suppressing the contact of water with a connected part of the first core and the first barrel portion where different types of metals are connected.

The following configurations are preferable as embodiments of the invention.

The linking portion may be a plate-like bottom plate, and the water drainage portion may be a projecting portion projecting from a plate surface of the bottom plate. According to such a configuration, the intrusion of water along the linking portion from the second barrel portion toward the first barrel portion can be suppressed by the projecting portion projecting from the plate surface of the bottom plate.

The projecting portion may be formed by bending the bottom plate. According to such a configuration, the water drainage portion can be easily formed only by bending the bottom plate.

The projecting portion may extend in a width direction intersecting with an arrangement direction of the first and second barrel portions and be formed over the entire width of the bottom plate. According to such a configuration, since the projecting portion is entirely formed in the width direction of the bottom plate, the intrusion of water from the second barrel portion toward the first barrel portion can be further suppressed as compared with a case where the projecting portion is partly formed in the width direction of the bottom plate.

The projecting portion may be a resin ring surrounding the bottom plate over the entire circumference. According to such a configuration, since the water drainage portion can be formed on the outer periphery of the bottom plate over the entire circumference, the intrusion of water from the second barrel portion toward the first barrel portion can be reliably restricted.

The water drainage portion may be a through hole formed to penetrate through the linking portion. According to such a configuration, the intrusion of water from the second barrel portion toward the first barrel portion can be suppressed by discharging the water running down along the linking portion through the through hole. Further, the water drainage portion can be easily and inexpensively formed by forming the through hole penetrating through a part, which will become the linking portion, in a plate thickness direction in punching a metal plate material constituting the relay terminal by a press.

The linking portion may be a plate-like bottom plate long and narrow in an arrangement direction of the first and second barrel portions, and the through hole may extend in a width direction intersecting with the arrangement direction of the first and second barrel portions. According to such a configuration, the intrusion of water along the linking portion from the second barrel portion toward the first barrel portion can be further suppressed as compared with a case where the through hole as the water drainage portion is formed to be narrow in the width direction.

The water drainage portion may be a cut groove formed by recessing at least one of the upper and lower surfaces of the linking portion. According to such a configuration, the intrusion of water from the second barrel portion toward the first barrel portion can be suppressed by discharging the water running down along the linking portion through the cut groove. Further, since the cut groove can be formed such as by striking the linking portion, the water drainage portion can be easily and inexpensively formed.

The cut groove may be formed on both the upper and lower surfaces of the linking portion. According to such a configuration, the intrusion of water from the second barrel portion toward the first barrel portion can be further suppressed.

The linking portion may be a plate-like bottom plate long and narrow in an arrangement direction of the first and second barrel portions, and the cut groove may be formed over the entire width of the bottom plate in a width direction intersecting with the arrangement direction of the first and second barrel portions. According to such a configuration, the intrusion of water from the second barrel portion toward the first barrel portion can be further suppressed as compared with a case where the cut groove as the water drainage portion is formed to be narrow in the width direction.

The first barrel portion caulked and crimped to the first core may be covered by a tubular waterproof covering. According to such a configuration, the intrusion of water not only from the second barrel portion, but also in outer peripheral directions, which are vertical and width directions, can be suppressed since the outer peripheral surface of the connected part of the first core and the first barrel portion is covered by the waterproof covering.

The first barrel portion may be made of copper or copper alloy, and the first core may be made of aluminum or aluminum alloy. Aluminum or aluminum alloy is easily dissolved in the event of electrolytic corrosion since having a higher tendency to ionize than copper or copper alloy. However, since the intrusion of water from the second barrel portion toward the first barrel portion can be further suppressed by the water drainage portion, the water drainage portion is particularly effective in the case of connecting the first barrel portion made of copper or copper alloy to the core made of aluminum or aluminum alloy.

The first and second wires may be arranged in a vehicle.

The application of the relay terminal to the first and second wires arranged in the vehicle is particularly effective.

According to the present invention, it is possible to suppress the progress of electrolytic corrosion in a part where different types of metals are connected.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment of the present invention is described with reference toFIGS. 1 to 3. A relay terminal10electrically conductively connected to an aluminum wire (an example of a first wire)20and a copper wire (an example of a second wire)30to be arranged in a vehicle (not shown) such as an automotive vehicle to join the both wires20,30is illustrated in this embodiment as shown inFIGS. 1 and 2.

The aluminum wire20is composed of an aluminum core (an example of a first core)21made of a conductive material such as aluminum or aluminum alloy and an insulation coating22made of synthetic resin and covering the outer periphery of the aluminum core21. The insulation coating22is removed by a predetermined length at an end of the aluminum wire20to expose the aluminum core21.

The copper wire30is composed of an copper core (an example of a second core)31made of a conductive material such as copper or copper alloy and an insulation coating32made of synthetic resin and covering the outer periphery of the copper core31. The insulation coating32is removed by a predetermined length at an end of the copper wire30to expose the copper core31.

The relay terminal10is manufactured by punching a flat copper plate made of a conductive material such as copper or copper alloy by a press and bending the punched piece. The relay terminal10includes a first barrel portion11to be connected to the end of the aluminum wire20, a second barrel portion12to be connected to the end of the copper wire30and a flat bottom plate (an example of a linking portion)13linking the first and second barrel portions11,12.

The first barrel portion11includes a first wire barrel14to be caulked and crimped to the aluminum core21exposed at the end of the aluminum wire20, a first insulation barrel15to be caulked and crimped to the insulation coating22of the aluminum wire20and a first bottom plate16formed common to the first wire barrel14and the first insulation barrel15.

The first wire barrel14is of a so-called open barrel type to be caulked and crimped to the aluminum core21of the aluminum wire20in such a manner as to embrace the aluminum core21from opposite sides, and includes a pair of first wire barrel pieces14A,14A rising upward from opposite widthwise side edges of the first bottom plate16while facing each other. The pair of first wire barrel pieces14A,14A are electrically conductively connected to the aluminum core21by being caulked and crimped to the aluminum core21in such a manner as to be wound on the outer periphery of the aluminum core21in the aluminum wire20placed on the first bottom plate16.

The first insulation barrel15is formed on an end part of the first barrel portion11opposite to the bottom plate13and includes a pair of first insulation barrel pieces15A,15A rising upward from opposite widthwise side edges of the first bottom plate16while facing each other. The pair of first insulation barrel pieces15A,15A are caulked and crimped to the insulation coating22in such a manner as to be wound on the outer periphery of the insulation coating22in the aluminum wire20placed on the first bottom plate16.

Further, the first barrel portion11is covered together with the aluminum core21of the aluminum wire20by a tubular heat shrinkable tube T (an example of a waterproof covering). Specifically, after being fitted on the aluminum core21, the first wire barrel14caulked and crimped to the aluminum core21and the first insulation barrel15caulked and crimped to the insulation coating22, the tubular heat shrinkable tube T is heated to shrink, whereby the outer peripheral surfaces of the aluminum core21, the first wire barrel14and the first insulation barrel15are waterproofed by the heat shrinkable tube T. This can suppress the intrusion of water into a connected part of the aluminum core21and the first barrel portion11in outer peripheral directions such as vertical and width directions.

The second barrel portion12includes a second wire barrel17to be caulked and crimped to the copper core31exposed at the end of the copper wire30, a second insulation barrel18to be caulked and crimped to the insulation coating32of the copper wire30and a second bottom plate19formed common to the second wire barrel17and the seconds insulation barrel18.

The second wire barrel17is of a so-called open barrel type to be caulked and crimped to the copper core31of the copper wire30in such a manner as to embrace the copper core31from opposite sides, and includes a pair of second wire barrel pieces17A,17A rising upward from opposite widthwise side edges of the second bottom plate19while facing each other. The pair of second wire barrel pieces17A,17A are electrically conductively connected to the copper core31by being caulked and crimped to the copper core31in such a manner as to be wound on the outer periphery of the copper core31in the copper wire30placed on the second bottom plate19.

The second insulation barrel18is formed on an end part of the second barrel portion12opposite to the bottom plate13and includes a pair of second insulation barrel pieces18A,18A rising upward from opposite widthwise side edges of the second bottom plate19while facing each other. The pair of second insulation barrel pieces18A,18A are caulked and crimped to the insulation coating32in such a manner as to be wound on the outer periphery of the insulation coating32in the copper wire30placed on the second bottom plate19.

The bottom plate13is in the form of a flat plate extending in an arrangement direction of the first and second barrel portions11,12and integrally formed to the first bottom plate16of the first barrel portion11and the second bottom plate19of the second barrel portion12. Further, the bottom plate13links the first and second barrel portions11,12such that the aluminum wire20connected to the first barrel portion11and the copper wire30connected to the second barrel portion12are coaxial. Specifically, the both wires20,30are arranged while being spaced apart in an extending direction of the bottom plate13.

A water drainage portion40is formed at an intermediate position of the bottom plate13between the first and second barrel portions11,12. The water drainage portion40is a projecting portion41projecting upward from the upper surface of the bottom plate13, and formed by bending the bottom plate13upward, folding the bottom plate13in such a manner that opposite sides are held in close contact and bending the bottom plate13in an axial direction of the two wires20,30. Further, the projecting portion41extends in a width direction intersecting with the extending direction of the bottom plate13and is formed over the entire width of the bottom plate13. Specifically, the upper surface of the first bottom plate16on which the aluminum wire20is placed and the upper surface of the second bottom plate19on which the copper wire30is placed are separated by the projecting portion41.

This embodiment is configured as described above. Next, functions and effects of the relay terminal10are described.

Water may fall on wires arranged in a vehicle. If water adheres to the copper wire30, the water adhering to the copper wire30may run down along the bottom plate13and intrude into the first barrel portion11connected to the aluminum wire20from the second barrel portion12connected to the copper wire30. If dust or sand intrudes and mixed salt content adheres in a state where water is in contact with a connected part of the aluminum core21and the first wire barrel14, the connected part is immersed in an electrolyte solution and electrolytic corrosion proceeds.

However, according to this embodiment, the projecting portion41separating the upper surface of the first bottom plate16on which the aluminum wire20is placed and that of the second bottom plate19on which the copper wire30is placed is formed on the bottom plate13between the first and second barrel portions11,12. That is, the projecting portion41can suppress the intrusion of water into the connected part of the aluminum core21and the first wire barrel14by blocking the water going to intrude along the upper surface of the bottom plate13from the second barrel portion12toward the first barrel portion11and discharging it in the width direction. This can suppress the progress of electrolytic corrosion in the connected part of the aluminum core21and the first wire barrel14. Further, since the aluminum core21made of aluminum or aluminum alloy has a higher tendency to ionize than copper and copper alloy, the projecting portion41is particularly effective for the aluminum wire20connected to the relay terminal10made of copper or copper alloy.

Further, since the outer peripheral surface of the connected part of the aluminum core21and the first barrel portion11is covered by the heat shrinkable tube T according to this embodiment, the intrusion of water not only from the second barrel portion12, but also in the outer peripheral directions, which are the vertical and width directions, can be suppressed. This can further suppress the progress of electrolytic corrosion in the connected part of the aluminum core21and the first wire barrel14.

Further, since the projecting portion41of this embodiment can be formed only by bending the bottom plate13by the press, it can be easily formed.

Next, a second embodiment of the present invention is described with reference toFIG. 4. In a relay terminal110of the second embodiment, the shape of the water drainage portion40in the first embodiment is changed. Components, functions and effects common to the above embodiment are not described to avoid repeated description. Further, the same components as in the above embodiment are denoted by the same reference signs.

A water drainage portion140in the relay terminal110of the second embodiment is formed into an inverted U shape by bending a bottom plate13upward, bending the bottom plate13in an axial direction of two wires20,30, bending the bottom plate13downward and then bending the bottom plate13in the axial direction of the two wires20,30, and formed over the entire width of the bottom plate13. Specifically, the water drainage portion140includes a projecting portion141projecting upward from the upper surface of the bottom plate13and a recessed groove142formed by recessing the lower surface of the bottom plate13upward. The upper surface of a first bottom plate16on which the aluminum wire20is placed and that of a second bottom plate19on which the copper wire30is placed are separated by the projecting portion141, and the lower surface of the bottom plate13is partitioned by the recessed groove142. This can suppress the intrusion of water along the upper surface of the bottom plate13from a second barrel portion12toward a first barrel portion11and suppress the intrusion of water along the lower surface of the bottom plate13from the second barrel portion12toward the first barrel portion11. Consequently, the progress of electrolytic corrosion in a connected part of an aluminum core21and a first wire barrel14can be suppressed.

Next, a third embodiment of the present invention is described with reference toFIG. 5. In a relay terminal210of the third embodiment, the shape of the water drainage portion40in the first embodiment is changed. Components, functions and effects common to the above embodiments are not described to avoid repeated description. Further, the same components as in the above embodiments are denoted by the same reference signs.

A water drainage portion240in the relay terminal210of the third embodiment is a through hole241formed to penetrate through a bottom plate13in the vertical direction (plate thickness direction of the bottom plate13) and extends in the width direction. Specifically, the through hole241can discharge water running down along the upper surface of the bottom plate13downward. This can suppress the intrusion of water from a second barrel portion12toward a first barrel portion11by discharging the water going to intrude along the upper surface of the bottom plate13from the second barrel portion12toward the first barrel portion11downward through the through hole241.

Further, since the through hole241can be simultaneously formed when a plate material made of copper or copper alloy and constituting the relay terminal210is punched by a press, it can be easily and inexpensively formed as in the first embodiment.

Next, a fourth embodiment of the present invention is described with reference toFIG. 6. In a relay terminal310of the fourth embodiment, the shape of the water drainage portion40in the first embodiment is changed. Components, functions and effects common to the above embodiments are not described to avoid repeated description. Further, the same components as in the above embodiments are denoted by the same reference signs.

A water drainage portion340in the relay terminal310of the fourth embodiment is in the form of cut grooves341formed by grooves having a recessed cross-section (U-shaped grooves) by striking the upper and lower surfaces of a bottom plate13, and formed over the entire width of the bottom plate13. Further, one cut groove341is formed on the upper surface of the bottom plate and two are formed on the lower surface, and the two cut grooves341on the lower surface are formed side by side in an extending direction of the bottom plate13. Specifically, the cut grooves341are capable of discharging water running down along the upper and lower surfaces of the bottom plate13in the width direction. This can suppress the intrusion of water from a second barrel portion12toward a first barrel portion11by discharging the water going to intrude along the upper and lower surfaces of the bottom plate13from the second barrel portion12toward the first barrel portion11in the width direction by the cut grooves341.

Further, since the cut grooves341can be formed by striking the bottom plate13, they can be easily and inexpensively formed as in the first embodiment.

Next, a fifth embodiment of the present invention is described with reference toFIG. 7. In the fifth embodiment, the shape of the water drainage portion40and the heat shrinkable tube in the first embodiment are changed. Components, functions and effects common to the above embodiments are not described to avoid repeated description. Further, the same components as in the above embodiments are denoted by the same reference signs.

A water drainage portion440in the relay terminal410of the fifth embodiment is a resin ring441formed by surrounding a bottom plate13over the entire circumference by resin such as through molding. Further, the resin ring441is formed to be thick on an upper surface side of the bottom plate13and thin on a lower surface side of the bottom plate13. A thickness of the resin ring441on the upper surface side of the bottom plate13is substantially equal to heights of cores21,31of two wires20,30, and that of the resin ring441on the lower surface side of the bottom plate13is substantially equal to plate thicknesses of first and second barrel portions11,12. Specifically, the resin ring441is set to have substantially the same height as a first wire barrel14connected to an aluminum core21and a second wire barrel17connected to a copper core31, and is slightly offset downward from the first wire barrel14connected to the aluminum core21and the second wire barrel17connected to the copper core31.

A heat shrinkable tube (an example of the waterproof covering) T1of the fifth embodiment is set to have a length from an end of an insulation coating22in the aluminum wire20to an end of an insulation coating32in the copper wire30. After collectively covering the outer peripheral surface of the first wire barrel14connected to the aluminum core21, that of the second wire barrel17connected to the copper core31and that of the resin ring441over the entire circumferences, the heat shrinkable tube T1is heated to shrink, thereby being held in close contact with the outer peripheral surface of the relay terminal410. Specifically, the relay terminal410is protected so as not to come into contact with water by being enclosed in the heat shrinkable tube T1. Note that since the first wire barrel14connected to the aluminum core21, the second wire barrel17connected to the copper core31and the resin ring441are set to have substantially the same height, the heat shrinkable tube T1can be reliably held in close contact with the outer peripheral surfaces thereof. This can prevent the intrusion of water into a connected part of the aluminum core21and the first wire barrel14.

Even if water intrudes into the second barrel portion12in the heat shrinkable tube T1, the intrusion of the water into the first barrel portion11from the second barrel portion12can be prevented and the progress of electrolytic corrosion in the connected part of the aluminum core21and the first wire barrel14can be suppressed since the resin ring441surrounding the bottom plate13is formed on the bottom plate13between the first and second wire barrels11,12and the heat shrinkable tube T1is held in close contact with the resin ring441.

The present invention is not limited to the above described and illustrated embodiments. For example, the following embodiments are also included in the technical scope of the present invention.

Although the projecting portion41is configured to project only upward from the upper surface of the bottom plate13in the above first embodiment, the present invention is not limited to such a mode. For example, a projecting portion may project downward from the lower surface of the bottom plate13.

Although the bottom plate13is formed with one water drainage portion40,140,240or440in each of the above first, second, third and fifth embodiments, the present invention is not limited to such a mode. For example, the bottom plate13may be formed with a plurality of water drainage portions.

Although the cut grooves341have a U-shaped cross-sectional shape in the above fourth embodiment, the present invention is not limited to such a mode. For example, the cut grooves may have a V-shaped or arcuate cross-sectional shape.

Although the second wire is the copper wire30, there is no limitation to this. The second wire may be an aluminum wire in which a second core is made of aluminum or aluminum alloy. An arbitrary metal can be appropriately used according to need.

The relay terminal can be applied not only in the case of electrically connecting the first and second wires arranged in the vehicle, but also in the case of electrically connecting first and second wires arranged in an arbitrary place according to need.

LIST OF REFERENCE SIGNS