Electric connection casing

Abstract: An electric connection casing comprising a large intensity-current circuit through electric current having a large intensity flows; a small intensity-current circuit through electric current having a small intensity flows; and a fuse and a relay interposed between the large intensity-current circuit and the small intensity-current circuit, wherein the large intensity-current circuit and the small intensity-current circuit comprise a plurality of single core wires, respectively; and a plurality of pressure-contact terminals which penetrates through an insulation coating of the single core wire, thus being connected with the single core wire by pressing the pressure-contact terminal against the single core wire.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an electric connection casing for use in a car, and more particularly, to an electric connection casing comprising electric circuits, a plurality of relays, fuses, and the like. The electric connection casing is used to perform the branch-connection of a wire harness and an internal circuit thereof comprises electric wires and connection terminals connected with the electric wires under pressure. Description of the Prior Art Heretofore, the internal circuit of the electric connection casing comprises a bus bar processed by punching a conductive metal plate into a predetermined configuration. The internal circuit composed of only the bus bar makes it difficult to alter the design thereof. In order to solve this problem, an electric connection casing was proposed and disclosed in Japanese Laid-Open Utility Model Publications Nos. 1-166419 and 2-136989. In this electric connection casing, a circuit comprising electric wires and connection terminals connected therewith under pressure is used as a small intensity-current circuit easy to be design-altered and connected with load electrical components and the bus bar is used as a large intensity-current circuit connected with a power source. In the electric connection casing comprising the large intensity-current circuit composed of the bus bar and the small intensity-current circuit comprising electric wires and the pressure-contact terminals, it is necessary to accommodate the two circuits having different constructions in one electric connection casing. Thus, the internal construction of the electric connection casing is complicated, and in addition, many kinds of constituent parts are required and moreover, assembling process is increased because the large intensity-current circuit and the small intensity-current circuit are installed in the electric connection casing in different manners. Further, the electric connection casing is manufactured at a high cost, because both a punching die mold for forming the bus bar and a wiring die mold for wiring electric wires are required. In addition, if the large intensity-current circuit connected with the power source is used as pares of other types of cars, it is frequently necessary to alter the design thereof. In this case, it is necessary to alter the construction of the bus bar. Thus, even though only the small-current circuit to be connected with the load electrical components is composed of electric wires and pressure-contact terminals, problems which occurs when the large intensity-current circuit is composed of the bus bar cannot be solved. Heretofore, electric wires are wired in an upper case, a lower case or an insulation plate of the electric connection casing in advance and then, pressure-contact terminals are fixed to the electric wires under pressure. As shown in Fig. 12, see also US-A-5 156 557, the electric wires W to be wired inside the electric connection casing 100 comprise straight portions S and curved portions C. In wiring the electric wires as described above, the straight portions S can be wired easily but there is a possibility that the curved portions C cannot be easily bent and hence cannot be wired. In this case, it is necessary to bend the electric wires W at large angles or wire the electric wires without bending them. Thus, the electric connection casing has a low degree of freedom in design. Further, it occurs that electric wires interfere with each other. As a result, the electric wires cannot be wired. EP-A-0 572 052 discloses an electric connection casing comprising a large intensity-current circuit through which electric current having a large intensity flows; a small intensity-current circuit through which electric current having a small intensity flows; and a fuse and a relay terminal interposed between the large intensity-current circuit and the small intensity-current circuit, wherein the small intensity-current circuit comprises a plurality of single core wires, and a plurality of pressure contact terminals which penetrate through an insulation coating of the single core wire, thus being connected with the single core wire by pressing the pressure contact terminal against the single core wire. It is an object of the invention to provide an electric connection casing of the type indicated above, which solves the above-mentioned problem at a portion of an electric wire to be bent and the problem that electric wires cannot be wired due to interference between them. According to the invention, this object is achieved by the electric connection casing as defined in claim 1. In the above construction, the electric wires are cut to pieces at a portion to be bent so as to connect the pieces with each other by means of the pressure-contact terminal. The pressure-contact terminal is formed of a conductive metal p ate; and a plurality of slot forming portions, which will be termed "slot portions" for brevity, is projected from a connection portion, of the pressure-contact terminal, having a required configuration so that the slot portions cut an insulation film of the electric wire and is connected with a single core wire of the electric wire. In addition, a plurality of pins is projected from the connection portion, of the pressure-contact terminal, having a required configuration so that the pins penetrate through an insulation coating of the electric wire and thrust the core of the electric wire, and are connected with the electric wire. As described above, an electrical connection of a wired electric wire formed by connecting a plurality of electric wires with each other by means of the pressure-contact terminal is similar to that of a wired single electric wire. The desired portion means a portion of an electric wire which cannot be bent at a desired angle. Because separated pieces of the electric wire are connected with each other with the pressure-contact terminal to allow an electrical connection between the separated pieces, the electric wire can be used as an internal circuit inside the electric connection casing. The desired portion also means a portion which cannot be wired continuously, because electric wires adjacent to each other interfere with each other. In this case, a portion at which electric wires interfere with each other is cut to connect separated pieces with each other by means of the pressure-contact terminal. The connection portion of the pressure-contact terminal is formed into the configuration corresponding to that of the end portions of each separated electric wire, and the slot or the pin is projected from the connection portion in correspondence to the number of electric wires to be connected with each other and the positions of the electric wires. In this manner, the pressure-contact terminal securely connects the electric wires to each other. Operation efficiency can be improved by connecting the pressure-contact terminal provided with an external input/output terminal and an electric wire with each other. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings throughout which like parts are designated by like reference numerals, and in which: Fig. 1 is an exploded perspective view showing an electric connection casing to which the present invention is applicable; Fig. 2A is a sectional view showing an electric wire of a large intensity-current circuit and a pressure-contact terminal; Fig. 2B is a sectional view showing an electric wire of a small intensity-current circuit and a pressure-contact terminal; Fig. 3A is an imaginary diagrammatic view showing an ideal bending state of an electric wire; Fig. 3B is an exploded perspective view showing an electric connection casing, according to the present invention, in which an electric wire is cut at a to-be-bent portion to connect its pieces formed by the cutting with each other with a connection terminal; Fig. 4A is a perspective view showing a part of a wiring die; Fig. 4B is a schematic view showing a wired electric wire in the wiring die; Fig. 5A is an imaginary diagrammatic view showing an ideal bending state of an electric wire; Fig. 5B is an exploded perspective view showing an electric connection casing, according to the present invention, in which an electric wire is cut at a to-be-bent portion to connect its pieces formed by the cutting with each other with a connection terminal; Fig. 6A is an imaginary diagrammatic view showing a state in which adjacent electric wires interfere with each other; Fig. 6B is an exploded perspective view showing an electric connection casing, according to the present invention, in which an electric wire is cut at an interfered portion to connect its pieces formed by the cutting with each other with a connection terminal; Fig. 7 is a perspective view showing a modification of the connection terminal; and Fig. 8 is a perspective view showing a conventional electric connection casing accommodating wired electric wires. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric connection casing according to the present invention is described below with reference to the drawings. Fig. 1 is an exploded perspective view showing an electric connection casing. A large intensity-current circuit 1 to be connected with a power source comprises a thick wire 2 having a large-diameter single core; and a pressure-contact terminal 3 to be pressed against the thick electric wire 2. A small intensity-current circuit 4 to be connected with a load electrical components comprises a thin wire 5 having a small-diameter single core; and a pressure-contact terminal 6 to be pressed against the thin electric wire 5. The thick electric wire 2 of the large intensity-current circuit 1 is wired by inserting the thick electric wire 2 into a wide wiring groove 8 formed on the upper surface of an insulation plate 7, while the thin electric wire 5 of the small intensity-current circuit 4 is wired by inserting the thin electric wire 5 into a narrow wiring groove (not shown) formed on the lower surface of the insulation plate 7. The thick electric wire 2 and the thin electric wire 5 are wired on a wiring die (not shown), respectively and then, transferred from the wiring die to the insulation plate 7. That is, the thick electric wire 2 and the thin electric wire 5 are wired at a time, respectively. After the thick electric wire 2 and the thin electric wire 5 are wired on the wiring groove 8 of the insulation plate 7, pressure-contact terminals 3 and 6 are pressed to predetermined positions on the wire 2 and 5. Thereby, as shown in Figs. 2A and 2B, insulation coating 2a and 5a of each of the electric wires 2 and 5 are broken with slot portions 3a and 6a of each of the pressure-contact terminals 3 and 6 to bring the end surface of cutting edges 3b and 6b formed on the inner peripheral surface of each of the slot portions 3a and 6a into contact with single core wires 2b and 5b of each of the electric wires 2 and 5. The diameter of the single core wire 2b of the thick electric wire 2 shown in Fig. 2A is great, and the sectional area of the single core wire 2b is set to be greater than 1.25mm 2 , while the diameter of the single core wire 5b of the thin electric wire 5 shown in Fig. 2B is small, and the sectional area of the single core wire 5b is set to be smaller than 1.25mm 2 . Therefore, the slot width SW1 of the pressure-contact terminal 3 to be brought into contact with the thick electric wire 2 under pressure is set to be great, whereas the slot width SW2 of the pressure-contact terminal 6 to be brought into contact with the thin electric wire 5 under pressure is set to be small to reliably bring the cutting edges 3b and 6b into contact with each of the core wires 2b and 5b in a constant area. As described above, all internal circuit positioned in the connecting casing and comprising the large intensity-current 1 and the small intensity-current 4 are composed of the electric wire 2 and 5 and the pressure-contact terminal 3 and 6 brought into contact therewith under pressure. Then, as necessary, a relay terminal 9 is connected with each of input/output terminals 3c and 6c composing the upper portion of each of the pressure-contact terminals 3 and 6. Then, an upper case 10 and a lower case 11 are assembled with insulation plate 7 interposed therebetween and with the input/output terminals 3c and 6c projecting from each of holes 10a and 11a formed on each of the upper case 10 and the lower case 11. A fuse 12 and a connector (not shown) are mounted on the upper case 10 and the lower case 11, the input/output terminals 3c and 6c are projected from each connector to connect them with external terminals, and a terminal of each fuse 12 is inserted into the relay terminal 9 so as to connect the terminal of each fuse 12 with each of the pressure-contact terminals 3 and 6. In the electric connection casing having the above-described construction, all internal circuits including the large intensity-current circuit and the small intensity-current circuit connected with the load electrical components are composed of electric wires and pressure-contact terminals. Thus, the designs of the internal circuits can be easily altered. Further, because the internal circuits do not comprise bus bars, it is unnecessary to use a bus bar-punching die and hence the electric connection casing can be manufactured at a low cost and in addition, can be used in various kinds of cars. Further, compared with the conventional electric connection casing comprising the bus bars, circuits are mounted on the electric connection casing in the same mounting method. Thus, the circuits can be mounted on the electric connection casing easily and the electric connection casing can be composed of a small number of parts. Further, because the electric wire comprises a single core wire, it can be connected securely with the pressure-contact terminal. Furthermore, because the electric wire of the large intensity-current circuit comprises the large-diameter single core wire, electric current having an appropriate intensity can be allowed to flow therethrough. Similarly, because the electric wire of the small intensity-current circuit comprises the small-diameter single core wire, electric current having an appropriate intensity can be allowed to flow therethrough as well. Figs. 3 through 7 show an electric connection casing according to the present invention. In this embodiment, electric wires are wired for connecting with terminals fixed to a lower case in advance. As shown in Fig. 3, one electric wire W comprises straight portions S and S and a curved portion C. Let it be supposed that the electric wire W is required to be bent perpendicularly. Fig. 3A shows a state before the electric wire W is cut assuming that the electric wire W can be bent perpendicularly. If the electric wire W is so hard that it cannot be bent perpendicularly, it is cut at both ends of the curved portion C along a cutting line L shown in Fig. 3A to connect the straight portions S and S with each other by means of a connection terminal 60 of a pressure-contact type, as shown in Fig. 3B. The electric wire W is wired by feeding it successively from a head roller 56 to a wiring die 54, as shown in Fig. 4, on which a wiring groove 53 has been formed, by means of an electric wire-feeding device 55. After the electric wire W is wired into the wiring groove 53, the lower case of the electric connection casing to which the pressure-contact terminal has been fixed is set on the wiring die 54, the electric wire W is connected with the pressure-contact terminal under pressure, and then, a push pin is projected from the bottom surface of the wiring die so as to press the lower case on which the terminal and the electric wire W have been installed from the wiring die 54. In wiring the electric wire W on the wiring die 54, the electric wire W is wired by cutting portions thereof which cannot be bent perpendicularly. The electric wire W is also cut at a portion thereof which cannot be bent perpendicularly in wiring it by inserting it into a wiring groove formed on the lower case, the upper case or the insulation plate and then, fixing it by pressing the contact-pressure terminal downward against the electric wire W. The pressure-contact terminal 60 for connecting the straight portions S and S of the electric wire W with each other at the point which can be bent perpendicularly is formed of a conductive metal plate. The pressure-contact terminal 60 comprises a connection portion 61 composed of an L-shaped flat plate bent perpendicularly in a horizontal direction; and slot portions 62 and 63 projecting downward from edges of the connection portion 61. The slot portions 62 and 63 comprise cutting edges 62a and 63a which contact a core wire 65 when an insulation coating 64 of the electric wire W is cut. When the pressure-contact terminal 60 is pressed downward against a portion proximate to the cut portions of the electric wire W, the cutting edges 62a and 63a cut the insulation coating 64, thus contacting the core wire 65. In this manner, the straight portions S and S are connected with each other via the pressure-contact terminal 60. Figs. 5A and 5B show a state in which the electric wire W is bent in the configuration of U. Because the electric wire W cannot be bent as shown by dotted lines of Fig. 5A, the electric wire W is cut along a line L and the straight portions S and S are arranged in parallel with each other, as shown in Fig. 5B. The separated straight portions S and S of the electric wire W are connected with each other with a pressure-contact terminal 20. The pressure-contact terminal 20 made of a conductive metal plate comprises a connection portion 21 positioned at the upper end thereof and two slot portions 22 and 23 positioned below the connection portion 21. The straight portions S and S of the wire W can be connected with each other by pressing the pressure-contact terminal 20 downward against a portion proximate to the leading end of each of the straight portions S and S. Referring to Figs. 6A and 6B, when it is ideal to wire an electric wire W2 at both sides of an electric wire W1 in such a manner that the electric wire W2 strides over the electric wire W1, the electric wire W2 is cut along a cutting line L and then, the two pieces of the electric wire W2 are connected with each other with a pressure-contact terminal 30. The pressure-contact terminal 30 comprises a connection portion 31 positioned at the upper end of a conductive metal plate; and two slot portions 32 and 33 projecting downward from both sides of the connection portion 31 and spaced from each other at a certain interval. The width of the slot portion 32 and that of the slot portion 33 correspond to the diameter of the electric wire W2. The separated electric wires W2 can be connected with the pressure-contact terminal 30 at the slot portions 32 and 33, with the connection portion 31 striding over the electric wire W1 at the center thereof when the pressure-contact terminal 30 is pressed downward against the electric wires W2. Instead of the contact-pressure terminal shown in Fig. 6B, a contact-pressure terminal 40 shown in Fig. 7 may be used. The contact-pressure terminal 40 comprises a connection portion 41; three wire-holding legs 42 projecting downward from the center of the connection portion 41 and from both sides thereof; and pins 43 and 44 projecting downward from the connection portion 41 and positioned between the adjacent wire-holding legs 42. The pins 43 and 44 penetrate through an insulation coating of each electric wire, thus thrusting the core of the electric wire. As a result, the electric wires and the contact-pressure terminal 40 are connected with each other. In the construction of the electric connection casing according to the invention, an electric wire is cut at a portion difficult to be wired so as to connect a plurality of separated pieces of the electric wire with the contact-pressure terminal. Accordingly, the electric wire can be wired easily. If the electric wire cannot be bent at a desired angle, the portion to be bent is cut so as to separate it into a plurality of pieces and connect the separated pieces with the connection terminal 60, 20, 30 or 40. The electric wire formed by the connection between the connection terminal 60, 20, 30 or 40 and the contact-pressure terminal for connecting with external wire can be used as an internal circuit of the electric connection casing. If the electric wires are wired at a high density and hence interfere with each other, they are cut and separated pieces are connected with the connection terminal 60, 20, 30 or 40 to wire them easily. Further, the connection terminal 60, 20, 30 or 40 for connecting electric wires thereto has a simple construction and can be easily composed of a conductive metal plate. Thus, the electric connection casing can be manufactured at a low cost. In addition, operation efficiency can be improved by connecting the contact-pressure terminal provided with an external input/output terminal and an electric wire with each other. Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

Claims: An electric connection casing comprising: a large intensity-current circuit (1) through which electric current having a large intensity flows; a small intensity-current circuit (4) through which electric current having a small intensity flows; and a fuse (12) and a relay terminal (9) interposed between the large intensity-current circuit (1) and the small intensity-current circuit (4), wherein the small intensity-current circuit (4) comprises a plurality of small diameter single core wires (5, W, W1, W2) and a plurality of pressure-contact terminals (6, 20, 30, 40, 60) which penetrate through an insulation coating of the small diameter single core wires (5, W, W1, W2), thus being connected with the small diameter single core wires (5, W, W1, W2) by pressing the pressure-contact terminal (6, 20, 30, 40, 60) against the small diameter single core wires (5, W, W1, W2), CHARACTERISED IN THAT the large intensity-current circuit (1) comprises a plurality of large diameter single core wires (2, W, W1, W2) and a plurality of pressure-contact terminals (3, 20, 30, 40, 60) which penetrate through an insulation coating of the large diameter single core wires (2, W, W1, W2), thus being connected with the large diameter single core wires (2, W, W1, W2) by pressing the pressure-contact terminal (3, 20, 30, 40, 60) against the large diameter single core wires (2, W, W1, W2), and at least one (W, W2) of said single core wires is formed by separate wire pieces (S, W2) connected with each other by means of one of said pressure-contact terminals (20, 30, 40, 60), said pressure contact terminal thereby replacing a curved portion (C) of the single core wire (W) that cannot easily be bent as required or a portion of the single core wire (W2) that would have interfered with other wires (W1). The electric connection casing according to claim 1, wherein the pressure-contact terminal (20; 30; 60) for connecting the wire pieces (S; W2) is formed of a conductive metal plate; and a plurality of slot forming portions (22, 23; 32, 33; 62, 63) are projected from a connection portion so that the slot forming portions cut an insulation coating of the single core wire and are connected with the core of the single core wire. The electric connection casing according to claim 1, wherein the pressure-contact terminal (40) is formed of a conductive metal plate; and a plurality of pins (43, 44) are projected from a connection portion so that the pins penetrate through an insulation coating of the single core wire and thrust the core of the single core wire.

Inventors: INOUE NORI, KOBAYASHI MAKOTO, KOUNOYA HISASHI, OKA YOSHITO, ONIZUKA TAKAHIRO, SAKA YUUJI, INOUE, NORI, KOBAYASHI, MAKOTO, KOUNOYA, HISASHI, OKA, YOSHITO, ONIZUKA, TAKAHIRO, SAKA, YUUJI, INOUE, NORI, C/O SUMITOMO WIRING SYSTEMS, LTD., Kobayashi, Makoto, c/o Sumitomo Wiring Sys., Ltd., Kounoya, Hisashi, c/o Sumitomo Wiring Sys., Ltd., Oka, Yoshito, c/o Sumitomo Wiring Sys., Ltd., ONIZUKA, TAKAHIRO, C/O SUMITOMO WIRING SYS., LTD., SAKA, YUUJI, C/O SUMITOMO WIRING SYSTEMS, LTD.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1995
Main classification: B60R16
IPC codes: H01R9, B60R16