Patent Publication Number: US-8993890-B2

Title: Electric cable and electric connector

Description:
The disclosure of Japanese Patent Application No. 2010-109991 filed on May 12, 2010, including the specification, drawings and abstract is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an electric cable and an electric connector and, more particularly, to an electric cable and an electric connector that are suitably used for an electrical connection in a limited wiring space. 
     2. Description of Related Art 
     There is known an existing hybrid vehicle that is equipped with an engine and a motor as a driving power source. Such a hybrid vehicle is, for example, equipped with a battery, such as a nickel metal hydride battery and a lithium ion battery. The hybrid vehicle converts direct-current voltage supplied from the battery to alternating-current voltage by an inverter and then applies the alternating-current voltage to the motor. By so doing, the hybrid vehicle is able to drive the motor for rotation to output driving power. 
     In the above hybrid vehicle, the inverter may be arranged in an engine compartment together with a drive unit that integrates the engine and the motor. The inverter and the motor are electrically connected to each other by electric cables. The drive unit mostly occupies a large volume in the engine compartment. Accordingly, the installation space of the inverter and the wiring space required to arrange the electric cables from the inverter to the motor may be extremely limited. Therefore, depending on the positional relationship between the inverter and the motor, more specifically, the relationship in position and orientation between the output terminals of the inverter, to which one ends of the electric cables are connected, and the input terminals of the motor, to which the other ends of the electric cables are connected, the electric cables might need to be arranged so as to be curved in an extremely narrow space. 
     Here, a related art document, for example, Japanese Patent Application Publication No. 2003-308738 (JP-A-2003-308738), describes an automobile wire harness. In this automobile wire harness, three electric wires are tied together by tape until a branch location, the three electric wires are separated into a set of two electric wires and a single wire and branched into two directions from the branch location, the terminal of the set of two electric wires is crimped with a single L-shaped terminal, a single L-shaped terminal is crimped with the terminal of the single electric wire, and the three electric wires are tied together by tape until the branch location to achieve branch direction control by which the two branch directions are along both right and left outer surfaces of an electric connection box and terminal direction control by which horizontal protruding portions of the two L-shaped terminals, each having a bolt hole, are located to face each other to thereby prevent the directions of the electric wires and L-shaped terminals of the wire harness branched into two directions from erroneously changing. 
     Incidentally, in a hybrid vehicle, mostly round electric wires are used for electric cables that connect an inverter to a motor. Each round electric wire has a copper wire and an insulating sheath material that covers the copper wire, and the copper wire and insulating sheath material have a circular cross-sectional shape. In contrast to this, a flat electric wire that has, for example, an oblong or elliptical cross-sectional shape has a larger surface area of an insulating sheath material that covers a copper wire than a round electric wire, so the flat electric wire has a relatively high heat dissipation characteristic during energization and is advantageous for suppressing a power loss due to a copper loss. 
     However, because the flat electric wire has a flattened cross-sectional shape having a longitudinal direction and a lateral direction, the flat electric wire is easy to bend in the lateral direction but the flat electric wire is hard to bend in the longitudinal direction. Therefore, when a flat electric wire is used for each of electric cables that connect an inverter to a motor in a hybrid vehicle, there is a problem that the flat electric wire can need to be curved in the direction in which the flat electric wire is hard to bend depending on the relationship in location, orientation, and the like, between the inverter and the motor and, therefore, the wiring space required for curving the flat electric wire increases. 
     Against the above problem, the automobile wire harness described in JP-A-2003-308738 is formed of three round electric wires and then prevents the directions of the set of two electric wires and single electric wire of the wire harness that are branched into two directions and the directions of the L-shaped terminals respectively crimped with the terminals of the branched set of two electric wires and single electric wire from erroneously changing. The automobile wire harness described in JP-A-2003-308738 does not provide a solution for the increased wiring space of the flat electric wire as described above. 
     SUMMARY OF THE INVENTION 
     The invention provides an electric cable that includes an electric wire that is hard to bend in a predetermined direction and easy to bend in a direction different from the predetermined direction and a terminal that is coupled to a terminal end of the electric wire and connected to an electrical apparatus, and that is able to reduce wiring space in such a manner that the easy bending direction is brought into coincidence or substantially coincidence with a bending direction in which the electric cable needs to be bent for a desired wiring direction, and also provides an electric connector that uses the electric cable. 
     An aspect of the invention provides an electric cable. The electric cable includes an electric wire that is hard to bend in a predetermined direction and easy to bend in a direction different from the predetermined direction and a terminal that is coupled to a terminal end of the electric wire and connected to an electrical apparatus. The terminal has a wire connection portion coupled to the terminal end of the electric wire and a connecting portion connected to the electrical apparatus, and is formed so that, when the terminal is connected to the electrical apparatus, a plane that includes a flat surface of the connecting portion is oriented in the direction in which the electric wire is easy to bend and intersects with the predetermined direction. 
     In the electric cable according to the aspect of the invention, the terminal may be formed of a metal plate and may be formed so that the connecting portion is bent with respect to the wire connection portion. 
     In addition, in the electric cable according to the aspect of the invention, the terminal may be formed of a metal plate and may be formed so that the connecting portion is twisted with respect to the wire connection portion. 
     In addition, in the electric cable according to the aspect of the invention, the electric wire may be a flat electric wire that has a flattened cross-sectional shape having a longitudinal direction and a lateral direction perpendicular to the longitudinal direction. 
     Furthermore, in the electric cable according to the aspect of the invention, the terminal may be formed so that the plane that includes the flat surface of the connecting portion is perpendicular to the predetermined direction in which the electric wire is hard to bend. 
     Another aspect of the invention provides an electric connector. The electric connector includes: a plurality of the electric cables that have any one of the structures described above and that are provided side by side; a connector housing that accommodates the wire connection portions of the terminals of the respective electric cables and parts of the connecting portions of the terminals of the respective electric cables and that allows distal end portions of the connecting portions of the terminals to protrude outward of the connector housing; and a seal member that is provided around end portions of the electric wires inside the connector housing and that keeps the inside of the connector housing in a fluid-tight state. 
     The above electric connector may include the three electric cables corresponding to three U, V and W phases, and the terminals of the electric cables may be respectively connected to output terminals of an inverter that serves as the electrical apparatus. 
     In addition, in the above electric connector, an angle, at which the plane that includes the flat surface of the connecting portion of the terminal of at least one of the three electric cables intersects with the predetermined direction in which the electric wire is hard to bend, may be varied from those of the other electric cables. 
     Furthermore, in the above electric connector, an angle, at which the plane that includes the flat surface of the connecting portion of the terminal of each of the three electric cables intersects with the predetermined direction in which the electric wire is hard to bend, may be varied among the three electric cables. 
     In the electric cable and the electric connector according to the aspects of the invention, the terminal is coupled to the terminal end of the electric wire, which is hard to bend in the predetermined direction and easy to bend in the direction different from the predetermined direction, and connected to the electrical apparatus, the terminal has the wire connection portion coupled to the terminal end of the electric wire and the connecting portion connected to the electrical apparatus, and the terminal is formed so that, when the terminal is connected to the electrical apparatus, the plane that includes the flat surface of the connecting portion is oriented in the direction in which the electric wire is easy to bend. By so doing, the direction in which the electric cable connected to the electrical apparatus by the terminal is easy to bend may be brought into coincidence or substantially coincidence with a bending direction in which the electric cable needs to be bent for a desired wiring direction. As a result, it is possible to reduce wiring space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein: 
         FIG. 1  is a schematic configuration diagram of the vehicle front portion of a hybrid vehicle in which electric cables and electric connectors according to an embodiment of the invention are used; 
         FIG. 2  is a view that shows the electric cables and the electric connector according to the embodiment and output terminal portions of an inverter to which the electric connector is connected; 
         FIG. 3  is a perspective view of an electric connector that includes flat electric wires to which existing general terminals are coupled; 
         FIG. 4  is an enlarged view of one of sets of the flat electric wire and the terminal that are included in the existing electric connector shown in  FIG. 3 ; 
         FIG. 5  is a perspective view of the electric connector according to the embodiment; 
         FIG. 6  is an enlarged view of one of sets of a flat electric wire and a terminal that are included in the electric connector shown in  FIG. 5 ; 
         FIG. 7  is an enlarged view of one of sets of a flat electric wire and another terminal that are included in the electric connector shown in  FIG. 5 ; 
         FIG. 8  is a cross-sectional view that shows a state where an electric connector according to an alternative embodiment to the embodiment, including the terminals shown in  FIG. 6 , is connected to the inverter; 
         FIG. 9  is a front view of a retaining member that is assembled to the electric connector shown in  FIG. 8 ; 
         FIG. 10A  is a view that shows the arrangement positions of three flat electric wires in the electric connector according to the embodiment and that shows the case where easy bending directions of the respective flat electric wires completely coincide with one another; and 
         FIG. 10B  is a view that shows the arrangement positions of the three flat electric wires in the electric connector according to the embodiment and that shows the case where easy bending directions of the respective flat electric wires substantially coincide with one another. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an embodiment of the invention will be described in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numeric values, directions, and the like, are only illustrative for easily understanding the aspect of the invention and may be modified appropriately to meet an application purpose, an object, specifications, and the like. 
       FIG. 1  schematically shows the inside of an engine compartment  12  of a front-engine rear-drive (FR) hybrid vehicle  10  when viewed from above. The hybrid vehicle  10  has the engine compartment  12  inside the body of a vehicle front  14 . A drive unit  22  is longitudinally mounted in the engine compartment  12 . The drive unit  22  is an integrated unit of an engine (E/G)  16  and two motors (MG 1  and MG 2 )  18  and  20 . A drive shaft  24  extends from the drive unit  22  toward a vehicle rear  15 . 
     The engine  16  is an internal combustion engine that is able to output power for propelling the vehicle and/or power for generating electric power using fuel, such as gasoline and light oil. For example, a three-phase alternating-current motor is suitably used for the motors  18  and  20 . The motors  18  and  20  each are able to function as both an electric motor and a generator. That is, the motors  18  and  20  each are driven for rotation with three-phase alternating-current voltages generated from direct-current voltage supplied from an in-vehicle battery (not shown) to be able to output driving power, while generating electric power with power transmitted from wheels during regeneration to be able to charge the battery with the generated electric power. In addition, when the state of charge of the battery is low, the motor  18 , for example, receives engine power to generate electric power, and then the battery is charged with the generated electric power. Furthermore, the motor  18  also functions as a starter motor that is driven with electric power from the battery to crank the engine  16  when the engine  16  is started. 
     Note that a secondary battery, such as a nickel metal hydride battery and a lithium ion battery, is suitably used for the battery, and may be mounted at the vehicle rear  15 . In addition, another electrical storage device, such as an electric double layer capacitor, may be, for example, used as an electrical storage device instead of the battery. 
     In the hybrid vehicle  10 , the motors  18  and  20  each are electrically connected to an inverter (INV)  26  via electric cables  28 . The inverter  26  includes an MG 1  inverter circuit and an MG 2  inverter circuit. The inverter  26  converts direct-current voltage supplied from the battery to, for example, three-phase alternating-current voltages and then applies the three-phase alternating-current voltages to each of the motors  18  and  20 . By so doing, the motors  18  and  20  are driven for rotation. 
     Suspension towers  30  are respectively formed on both right and left wall surfaces of the engine compartment  12 . Each suspension tower  30  is formed so that the vehicle body is swelled toward the inside of the engine compartment  12  so as to form a mounting space of a front wheel suspension portion on an outer side of the vehicle body. Each suspension tower  30  has an opening  32  at its upper portion. The opening  32  is usually closed by a cap member. The front wheel suspension portion may be assembled or adjusted through the opening  32 . 
     The drive unit  22  is arranged substantially at the center in the engine compartment  12 , and occupies a large volume in the engine compartment  12 . In addition, in the example shown in  FIG. 1 , the engine  16  of the drive unit  22  is located substantially at the center in the engine compartment  12 , and the motors  18  and  20  coupled to the engine  16  are provided at the lower side in the engine compartment  12  at a location that projects into a vehicle cabin  11 . 
     The inverter  26  is mounted at a rear side location in the engine compartment  12 . Therefore, in the example shown in  FIG. 1 , the inverter  26  is mounted on the left side (that is, the vehicle right side) of the drive unit  22  located at the center in a narrow space placed between an engine compartment rear wall surface  13   a  and the suspension tower  30  inside the engine compartment  12 . 
     In addition, the inverter  26  includes output terminals  34  (see  FIG. 2 ) for outputting alternating-current voltages converted from direct-current voltage. Each output terminal  34  is a portion to which an electric connector provided at the terminal ends of the electric cables  28  is connected. The rear side and vehicle right side (left side in  FIG. 1 ) of the inverter  26  are respectively located in proximity to the rear wall surface  13   a  and right wall surface  13   b  of the engine compartment  12 , and the drive unit  22  is located in proximity to the vehicle left side (right side in  FIG. 1 ) of the inverter  26 . Therefore, in order to easily connect and lead the electric cables  28  to the inverter  26 , the inverter  26  is mounted so that the output terminals  34  are oriented toward the front of the vehicle. 
       FIG. 2  shows a perspective view of the inverter  26  and an electric connector  40  connected to the inverter  26  with an enlarged view of the output terminals  34  of the inverter  26 . The inverter  26  is covered with an inverter case  42 . The inverter case  42  has two front side openings  44  and two upper side openings  46  at its front portion. The two front side openings  44  are open forward. The two upper side openings  46  are open upward. The pairs of front side opening  44  and upper side opening  46  respectively correspond to the output terminals  34  of the MG 1  inverter circuit and the output terminals  34  of the MG 2  inverter circuit. In this example, the output terminals  34  at the left side in the drawing are electrically connected to the motor  18  via the electric cables  28 , and the output terminals  34  at the right side in the drawing are electrically connected to the motor  20  via the other electric cables  28 . 
     As shown in the enlarged view surrounded by the alternate long and short dashed line in  FIG. 2 , the output terminals  34  of the inverter  26  are formed so that three terminal strips  34 U,  34 V and  34 W corresponding to the U, V and W phases of the motor  18  are arranged side by side. These terminal strips  34 U,  34 V and  34 W are arranged in the inverter case  42  so as to be exposed through the front side opening  44  and the upper side opening  46 . In addition, each of the terminal strips  34 U,  34 V and  34 W has a mounting hole  50 . 
     The electric cables  28  are also formed of three electric cables  28 U,  28 V and  28 W corresponding to the U, V and W phases of the motor  18 . The electric connector  40  is provided at the terminal ends of the three electric cables  28 U,  28 V and  28 W. The distal end portions of terminals  48 U,  48 V and  48 W of the respective phases protrude from the electric connector  40 . The mounting hole  52  is formed at each of the distal end portions of the terminals  48 U,  48 V and  48 W. 
     The thus configured electric connector  40  is inserted from the front side indicated by the arrow  53  into the front side opening  44  of the inverter  26 , and the terminals  48 U,  48 V and  48 W of the respective phases are placed on the terminal strips  34 U,  34 V and  34 W of the respective phases in a state where the mounting holes  52  and  50  communicate with each other. Then, the terminals  48 U,  48 V and  48 W of the respective phases are fixed to the terminal strips  34 U,  34 V and  34 W of the respective phases by bolts  54  inserted from the upper side opening  46  into the pairs of mounting holes  50  and  52  and nuts  56  screwed to the bolts  54 . By so doing, connecting the electric cables  28  to the inverter  26  is complete. Then, the upper side opening  46  of the inverter case  42  is closed by a cap member (not shown) to thereby prevent entry of water, or the like, into the inverter  26 . In addition, the front side opening  44  of the inverter case  42  is sealed by the electric connector  40  in a fluid-tight manner as will be described later. 
     Note that, in order to easily connect the electric cables  28 , the nuts  56  may be welded to the back surfaces of the respective terminal strips  34 U,  34 V and  34 W or the mounting holes  50  of the respective terminal strips  34 U,  34 V and  34 W may be formed as internal threaded holes to omit the nuts. 
       FIG. 3  and  FIG. 4  show an example of the case where electric cables  29  are formed of flat electric wires  58  each having a flattened cross-sectional shape and planar terminals  49  (terminals  49 U,  49 V and  49 W of the respective phases may be collectively referred to by “ 49 ”) each of which is made of a metal plate (for example, copper plate) connected to a corresponding one of the terminal ends of the flat electric wires  58 . The electric connector  40  is provided at the terminal ends of the electric cables  29 , and the distal end portions of the terminals  49 U,  49 V and  49 W of the respective phases protrude from the electric connector  40 , as in the case of the above described configuration. 
     The electric cables  28 U,  28 V and  28 W are respectively formed of the flat electric wires  58  each having a flattened cross-sectional shape. Each of the above flat electric wires  58  has a copper wire portion and an insulating sheath material  62 . The copper wire portion is formed so that a large number of narrow copper wires  60  are bundled to have a substantially oblong flattened cross-sectional shape or a substantially elliptical flattened cross-sectional shape. The insulating sheath material  62  covers the copper wire portion. The insulating sheath material  62  also has a substantially oblong flattened cross-sectional outer shape or a substantially elliptical flattened cross-sectional outer shape. Each of the flat electric wires  58  has a larger surface area of the insulating sheath material  62  than a round electric wire having an equivalent allowable current value, so the flat electric wire  58  has a relatively high heat dissipation characteristic during energization. Thus, even when the flat electric wire  58  has a relatively small copper wire cross-sectional area, a copper loss and heat generation when the flat electric wire  58  is supplied with the same current may be suppressed to the same level as that of a round electric wire, so the flat electric wire  58  is advantageous for suppressing a power loss. 
     On the other hand, as shown in  FIG. 4 , each flat electric wire  58  has a longitudinal direction L and a lateral direction S in the cross-sectional shape. The lateral direction S is perpendicular to the longitudinal direction L. Therefore, the flat electric wire  58  is hard to bend in the longitudinal direction L and easy to bend in the lateral direction S. Because the width of the flat electric wire  58  in the lateral direction S is smaller than the diameter of a round electric wire having an equivalent allowable current value, the flat electric wire  58  is easier to bend in the lateral direction S than a round electric wire, that is, the flat electric wire  58  may be bent in the form of a circular arc shape having a further smaller radius of curvature. 
     Note that each flat electric wire  58  has a substantially oblong cross-sectional shape or a substantially elliptical cross-sectional shape in the above description; however, the cross-sectional shape of each flat electric wire is not limited to these shapes. The cross-sectional shape may be, for example, another shape, such as a flattened rectangular shape. Alternatively, an electric wire not having a flattened cross-sectional shape but having a characteristic that is hard to bend in a predetermined direction and easy to bend in a direction different from the predetermined direction may be used. 
     Each of the terminals  49  coupled to the terminal ends of the flat electric wires  58  is made of a metal plate, and a copper plate is suitably used in view of electrical conductivity, cost, machinability, and the like. A proximal end portion  64  of each terminal  49  is coupled to copper wires  60  by a method, such as crimping. The copper wires  60  are exposed at the terminal end of the flat electric wire  58 . In addition, each terminal  49  is a general one that is formed as a flat plate of which substantially the entire, other than a portion crimped to the copper wires  60 , is extended in a narrow long shape so as to have a flat surface, and has the mounting hole  52  at its distal end portion. 
     When the above flat electric wires  58  and terminals  49  are used to form the electric cables  29 , planes that respectively include the flat surfaces of the distal end portions of the terminals  49 U,  49 V and  49 W protruding from the electric connector  40  are respectively arranged along the longitudinal directions L of the electric cables  29 U,  29 V and  29 W of the respective phases, extending through the electric connector  40 , as shown in  FIG. 3 . Therefore, in a state where the electric cables  29  are used for electrical connection between the inverter  26  and the motors  18  and  20  shown in  FIG. 1 , when the electric cables  29  of which the terminals  49  are connected to the output terminals  34  of the inverter  26  are bent in a substantially U-turn shape and connected to the motors  18  and  20 , the bending direction substantially coincides with a direction in which the flat electric wires  58  that constitute the electric cables  29  are hard to bend (that is, the longitudinal direction L of the cross-sectional shape). Therefore, it is difficult to bend the electric cables  29  to form a circular arc shape having a small radius of curvature at a near location, and, when the flat electric wires  58  are bent in a U-turn shape while being twisted at about 90 degrees, the flat electric wires  58  are curved with a large radius of curvature and require a large wiring space. 
     Then, as shown in  FIG. 5  and  FIG. 6 , in the electric cables  28  according to the present embodiment, when the terminals  48  (the terminals  48 U,  48 V and  48 W of the respective phases are collectively referred to by “ 48 ”, and the same applies to the following description) are connected to the inverter  26 , the planes that include the flat surfaces of connecting portions  68  of the terminals  48  are oriented in a direction in which the flat electric wires  58  are easy to bend and intersect with the predetermined direction. 
     Specifically, the electric cables  28  each include the flat electric wire  58  and the terminal  48 . The terminal  48  is coupled to the terminal end of the flat electric wire  58  and is connected to the output terminal  34  of the inverter  26 . The flat electric wires  58  are similar to those described above, so the description thereof is omitted here. On the other hand, each terminal  48  is, for example, formed of a metal plate, such as a copper plate, and has a wire connection portion  66  and the connecting portion  68 . The wire connection portion  66  is coupled to the copper wires  60  exposed at the terminal end of the flat electric wire  58  by a method, such as crimping. The connecting portion  68  is, for example, connected to the terminal strip  34 U of the output terminal  34  of the inverter  26  by fastening using the bolt  54  and the nut  56 . Then, the connecting portion  68  is bent so as to form a right angle or a substantially right angle with respect to the wire connection portion  66  or the wire connection portion  66  is bent so as to form a right angle or a substantially right angle with respect to the connecting portion  68 . By so doing, a flat surface  69  of the connecting portion  68  is oriented in the lateral direction S that is the direction in which the flat electric wire  58  is easy to bend. As a result, the easy bending direction of each of the electric cables  28  that are connected to the output terminals  34  of the inverter by the terminals  48  may be brought into coincidence or substantially coincidence with a bending direction in which the electric cables  28  need to be bent for a desired wiring direction, that is, the arrow X direction and the direction opposite to the arrow X direction here. Thus, the electric cables  28  of which the terminals  48  are connected to the inverter  26  may be bent in the form of a circular arc shape having a small radius of curvature at a location near the inverter  26 , so it is possible to reduce wiring space. 
     In addition, as shown in  FIG. 7 , in another terminal  48 , the connecting portion  68  may be twisted and bent so as to form a right angle or a substantially right angle with respect to the wire connection portion  66 , or the wire connection portion  66  may be twisted and bent so as to form a right angle or a substantially right angle with respect to the connecting portion  68 . By so doing as well, as in the case of the above described embodiment, the easy bending direction of each of the electric cables  28  may be brought into coincidence or substantially coincidence with a bending direction in which the electric cables  28  need to be bent for a desired wiring direction. 
     Note that, in the above description, the terminals  48  of the electric cables  28  are coupled to the end portions of the flat electric wires  58 , adjacent to the inverter  26 ; instead, the terminals  48  may also be coupled to the end portions of the flat electric wires  58  of the electric cables  28 , adjacent to the motors  18  and  20 . By so doing, it is possible to reduce wiring space also at the motor side, and, because the flat electric wires  58  are easier to bend than round electric wires, the flat electric wires  58  are advantageous for easily connecting the flat electric wires  58  to the input terminals of the motors  18  and  20 . 
     In addition, in the above description, the wire connection portion  66  and connecting portion of each terminal  48  form an angle of about 90 degrees; however, the aspect of the invention is not limited to this configuration. The bending angle or twisting angle of each terminal  48  may be set so as to bring the easy bending direction of each flat electric wire  58  into coincidence or substantially coincidence with a bending direction in which the electric cables  28  need to be bent for a desired wiring direction. 
     Next, an electric connector  40  according to an alternative embodiment to the embodiment of the invention will be described with reference to  FIG. 8  and  FIG. 9 .  FIG. 8  is a cross-sectional view that shows a state where the electric connector  40  that includes the terminals  48  shown in  FIG. 6  are connected to the inverter  26 .  FIG. 9  is a front view of a retaining member  82  that is assembled to the electric connector  40 . The electric connector  40  may be provided not only at a connecting end portion adjacent to the inverter  26  but also at a connecting end portion adjacent to the motor  18  or  20 . 
     The electric connector  40  includes the electric cables  28  and a connector housing  70 . The electric cables  28  are formed of three flat electric wires  58  corresponding to three U, V and W phases and the terminals  48  are respectively coupled to at least one ends of the respective electric wires. The connector housing  70  accommodates the end portions of the electric cables  28 , the wire connection portions  66  of the terminals  48  and parts of the connecting portions  68  of the terminals  48 . 
     The connector housing  70  may be suitably formed of a plastic molded product having a cylindrical outer peripheral wall portion. An electric wire insertion opening  72  is formed at one end of the connector housing  70 . A terminal opening  74  is formed at the other end of the connector housing  70  in order to allow the distal end portions of the connecting portions  68  of the terminals  48  to protrude outward of the housing. 
     In addition, two protruding strips  76  are formed on the outer peripheral surface of the connector housing  70  so as to be parallel to each other, and a seal member  78 , such as an O-ring, is held between these protruding strips  76 . When the electric connector  40  is inserted into the front side opening  44  of the inverter  26  and connected to the inverter  26 , the seal member  78  is pressed against the peripheral portion of the front side opening  44  to be brought into close contact with the peripheral portion of the front side opening  44  to thereby prevent entry of water into the inverter case  42 . 
     For example, a rubber seal member  80  is fitted around each of the end portions of the electric cables  28  located inside the connector housing  70 . The seal member  80  may be an O-ring that is separately fitted to each of the flat electric wires  58  or may be a single planar or cylindrical member having three through-holes of which hole edge portions are able to be in close contact with the outer peripheries of the three flat electric wires  58  in a fluid-tight manner. 
     The retaining member  82  is fixed inside the connector housing  70 . As shown in  FIG. 9 , the retaining member  82  may be formed of a plastic flat plate having a substantially elliptical outer shape, and has three circular through-holes  83  or a single oblong through-hole  84  through which the electric cables  28  with the terminals  48  are insertable. The retaining member  82  is fixed to the connector housing  70  by a method, such as adhesion and screwing. The retaining member  82  retains the vertical positions of the electric wires  58  in the electric wire insertion opening  72 , and prevents the seal member  80  from being displaced along the electric wires  58  to slip out of the housing. 
     Subsequently, assembling of the thus configured electric connector  40  will be simply described. 
     First, the seal member  80  and the retaining member  82  are fitted around the three flat electric wires  58  to which the terminals  48  are respectively coupled. After that, the three flat electric wires  58  are inserted into the electric wire insertion opening  72  of the connector housing  70  initially from the terminals  48 . Then, the distal end portions of the connecting portions  68  of the respective terminals  48  are allowed to protrude from the terminal opening  74  outward of the housing, and the seal member  80  is pressed into the connector housing  70 . Finally, the retaining member  82  is fixedly fitted into the electric wire insertion opening  72 . By so doing, assembling of the electric connector  40  is complete. 
     The electric connector  40  includes the electric cables  28  that respectively have the above described flat electric wires  58  and terminals  48 , so, after the terminals  48  of the electric connector  40  each are connected to the output terminals  34  of the inverter  26 , the flat electric wires  58  may be easily bent at a location immediately outside of the electric wire insertion opening  72  of the electric connector  40  with a small radius of curvature in a bending direction in which the electric cables  28  need to be bent for a desired wiring direction. Therefore, it is possible to reduce wiring space. 
     Here, as shown in  FIG. 10A , in the electric connector  40 , when the angle formed between the wire connection portion  66  and the connecting portion  68  is made equal among the terminals  48  of the electric cables  28 U,  28 V and  28 W of the respective phases formed of the flat electric wires  58 , the easy bending directions (horizontal directions in  FIG. 10A ) of the respective electric cables  28 U,  28 V and  28 W completely coincide with one another. However, in this case, when the three electric cables  28 U,  28 V and  28 W are arranged to bend in the same direction, there is a possibility that the three electric cables  28 U,  28 V and  28 W overlap with one another in the lateral direction as shown in the right view of  FIG. 10A  and, as a result, the electric cable  28 V placed in the middle is hard to dissipate heat. 
     In contrast to this, in the electric connector according to the present embodiment, the angle, at which a plane that includes the flat surface of the connecting portion of the terminal of at least one of a plurality of electric cables intersects with the longitudinal direction that is a direction in which the flat electric wire is hard to bend, may be varied from those of the other electric cables. 
     For example, as shown in  FIG. 10B , when the easy bending directions of the respective electric cables  28 U,  28 V and  28 W are shifted little by little, the three electric cables  28 U,  28 V and  28 W may be successively arranged in the longitudinal direction when the electric cables  28 U,  28 V and  28 W are, for example, arranged to bend rightward in  FIG. 10B . Thus, it is possible to avoid a situation that the heat dissipation characteristic decreases as described above. 
     The orientations or positions of the respective electric cables  28 U,  28 V and  28 W shown in  FIG. 10B  may be achieved in such a manner that the angle formed between the wire connection portion  66  and connecting portion  68  of the terminal  48  of the middle electric cable  28 V is set at 90 degrees, the angle formed between the wire connection portion  66  and connecting portion  68  of the terminal  48  of the left side electric cable  28 U is set so as to be slightly smaller than 90 degrees and the angle formed between the wire connection portion  66  and connecting portion  68  of the terminal  48  of the right side electric cable  28 W is set so as to be slightly larger than 90 degrees. 
     Note that the electric cable and electric connector according to the aspect of the invention are not limited to the above described embodiments; they may be modified or improved in various forms. 
     For example, in the above description, the electric cable and the electric connector are connected to the inverter and the motor that serve as electrical apparatuses to pass alternating current; however, the aspect of the invention is not limited to this configuration. The electric cable and the electric connector may be used in an electrical connecting portion for passing direct current between other electrical apparatuses, such as between a battery and a converter and between a battery and an inverter. 
     In addition, in the above description, the electric cable and the electric connector are used for an FR hybrid vehicle; however, the aspect of the invention is not limited to this configuration. The electric cable and the electric connector may be applied to a front-engine front drive (FF) hybrid vehicle or may be applied to a single motor hybrid vehicle, an electric vehicle, or the like. 
     Furthermore, the electric cable and the electric connector according to the aspect of the invention may be applied not only to an automobile but also to a mobile unit of any other type having limited wiring space for size reduction (for example, robot) or an installed machine.