Patent Publication Number: US-2023163492-A1

Title: Wire harness

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority from Japanese Patent Application No. 2021-189248, filed on Nov. 22, 2021, with the Japan Patent Office, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a wire harness. 
     BACKGROUND 
     Japanese Patent Laid-open Publication No. 2020-098786 discloses a device wiring assembly including a plurality of device wiring members each including a plurality of conductors and two connection portions provided at opposite ends of each of the conductors, wherein the device wiring members are wired in a bent state in a device including a device body and a device case that accommodates the device body. 
     SUMMARY 
     It is desirable that a wire harness such as the device wiring assembly disclosed in Japanese Patent Laid-open Publication No. 2020-098786 can be easily bent between one end and the other end thereof in a direction in which a twist occurs in wires. 
     Therefore, an object of the present disclosure is to provide a technique that can facilitate bending of a wire harness between one end and the other end thereof in a direction in which a twist occurs in wires. 
     A wire harness according to the present disclosure is a wire harness including: a plurality of wires each including a stranded conductor, and an insulation covering that covers the stranded conductor; a first terminal block including a first holding portion that holds one end portions of the plurality of wires, and a plurality of first terminals each electrically connected to the one end portion of a corresponding wire of the plurality of wires; and a second terminal block including a second holding portion that holds the other end portions of the plurality of wires, and a plurality of second terminals each electrically connected to the other end portion of a corresponding wire of the plurality of wires, wherein the plurality of wires are arranged side by side between the first holding portion and the second holding portion in a direction intersecting a direction connecting the first holding portion to the second holding portion, when an orientation in which the plurality of wires extend straight between the first holding portion and the second holding portion is defined as a first orientation, a connection orientation in which the first terminal block and the second terminal block are connected to the respective connection partners is a second orientation in which the plurality of wires are bent between the first holding portion and the second holding portion, and in which a twist occurs in the plurality of wires are bent from the first orientation, and a stranding direction of the stranded conductors of half or more wires of the plurality of wires is a direction in which stranding of the stranded conductors is tightened by the twist occurring when the plurality of wires are bent from the first orientation to the second orientation. 
     According to the present disclosure, it is possible to facilitate bending of a wire harness between one end and the other end thereof in a direction in which a twist occurs in wires. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view showing a wire harness according to an embodiment. 
         FIG.  2    is a side view showing the wire harness according to the embodiment. 
         FIG.  3    is a front view showing the wire harness according to the embodiment. 
         FIG.  4    is a cross-sectional view showing a wire. 
         FIG.  5    is an explanatory view showing an S-stranded conductor. 
         FIG.  6    is an explanatory view showing a Z-stranded conductor. 
         FIG.  7    is a front view showing the wire harness in a first orientation. 
         FIG.  8    is a front view showing a wire harness according to a first modification. 
         FIG.  9    is a front view showing a wire harness according to a second modification. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. 
     Description of Embodiments of the Present Disclosure 
     First, aspects of the present disclosure will be listed and described. 
     A wire harness according to the present disclosure is as follows. 
     (1) A wire harness wire harness including: a plurality of wires each including a stranded conductor, and an insulation covering that covers the stranded conductor; a first terminal block including a first holding portion that holds one end portions of the plurality of wires, and a plurality of first terminals each electrically connected to the one end portion of a corresponding wire of the plurality of wires; and a second terminal block including a second holding portion that holds the other end portions of the plurality of wires, and a plurality of second terminals each electrically connected to the other end portion of a corresponding wire of the plurality of wires, wherein the plurality of wires are arranged side by side between the first holding portion and the second holding portion in a direction intersecting a direction connecting the first holding portion to the second holding portion, when an orientation in which the plurality of wires extend straight between the first holding portion and the second holding portion is defined as a first orientation, a connection orientation in which the first terminal block and the second terminal block are connected to the respective connection partners is a second orientation in which the plurality of wires are bent between the first holding portion and the second holding portion, and in which a twist occurs in the plurality of wires are bent from the first orientation, and a stranding direction of the stranded conductors of half or more wires of the plurality of wires is a direction in which stranding of the stranded conductors is tightened by the twist occurring when the plurality of wires are bent from the first orientation to the second orientation. When the stranding direction of the stranded conductors is a direction in which the stranding of the stranded conductors is loosened by a twist occurring when the plurality of wires are bent from the first orientation to the second orientation, the insulation coverings impede the loosening of the stranded conductors. Therefore, a strong force is required to bend the wires. In contrast, when the stranding direction of the stranded conductors is a direction in which the stranding of the stranded conductors is tightened by a twist occurring when the plurality of wires are bent from the first orientation to the second orientation, the insulation coverings are prevented from impeding loosening of the stranding of the stranded conductors, thus making it possible to bend the wires with a weak force. This makes it possible to facilitate bending of the wire harness between one end and the other end thereof in a direction in which a twist occurs in the wires. 
     (2) In the wire harness according to (1), the second orientation may be an orientation in which the plurality of wires are bent about an axis extending in a side-by-side arrangement direction of the plurality of wires, and in which the one end portion and the other end portion of each of the plurality of wires are shifted from each other in the side-by-side arrangement direction by an amount greater than or equal to a diameter of the wire. When the plurality of wires are bent from the first orientation to such a second orientation, a twist also occurs in the plurality of wires. In this case as well, it is possible to facilitate bending of the wire harness between one end and the other end thereof in a direction in which a twist occurs in the wires. 
     (3) In the wire harness according to (2), in the second orientation, an angle formed by a direction in which the plurality of wires extend from the first holding portion and a direction in which the plurality of wires extend from the second holding portion may be 60 degrees or more and 120 degrees or less, and the side-by-side arrangement direction of the plurality of wires in the first holding portion and the side-by-side arrangement direction of the plurality of wires in the second holding portion are parallel to each other. In this case as well, it is possible to facilitate bending of the wire harness between one end and the other end thereof in a direction in which a twist occurs in the wires. 
     (4) In the wire harness according to any one of (1) to (3), a stranding direction of the stranded conductors of all of the plurality of wires may be a direction in which the twist occurring when the plurality of wires are bent from the first orientation to the second orientation tightens stranding of the stranded conductors. With this configuration, none of the plurality of wires is a wire in which the stranding direction of the stranded conductor is a direction in which the stranding of the stranded conductor is loosened by a twist occurring when the plurality of wires are bent from the first orientation to the second orientation, thus making it possible to facilitate bending of the wire harnesses between one end and the other end thereof in a direction in which a twist occurs in the wires. 
     (5) In the wire harness according to any one of (1) to (4), the number of the plurality of wires may be three or more. In this case as well, it is possible to facilitate bending of the wire harness between one end and the other end thereof in a direction in which a twist occurs in the wires. 
     (6) In the wire harness according to any one of (1) to (5), the insulation coverings may each have a Shore A hardness of 40 or more and 100 or less, as measured using a durometer compliant with JIS K 6253. In the case of a relatively hard insulation covering having a Shore A hardness of 40 or more and 100 or less, fastening of the stranded conductors by the insulation coverings is further tightened, and the stranded conductors are much less likely to be twisted in the direction in which they are loosened. In this case as well, the connection orientation is the orientation in which the stranded conductors of half or more of the wires are twisted in the direction in which they are tightened, and therefore the wire harness is likely to assume the connection orientation. 
     (7) In the wire harness according to any one of (1) to (6), the insulation coverings may each be made of a crystalline resin. With this configuration, the insulation coverings are likely to be hard as compared with an insulation covering made of an amorphous resin. In this case as well, the connection orientation is the orientation in which the stranded conductors of half or more of the wires are twisted in the direction in which they are tightened, and therefore the wire harness is likely to assume the connection orientation. 
     (8) In the wire harness according to any one of (1) to (7), the stranded conductors may each have a cross-sectional area of 10 sq or more and 50 sq or less, and a wire length between the first holding portion and the second holding portion may be 100 mm or more and 300 mm or less. With this configuration, even in the case of using wires having a relatively large diameter and a relatively short length, the connection orientation is an orientation in which the stranded conductors of half or more of the wires are twisted in the direction in which they are tightened, and therefore the wire harness is likely to assume the connection orientation. 
     (9) In the wire harness according to any one of (1) to (8), each of the first holding portion and the second holding portion may be a resin molded portion insert-molded using the plurality of wires as insert components. With this configuration, each of the first holding portion and the second holding portion can firmly hold the plurality of wires. 
     Details of Embodiments of the Present Disclosure 
     Specific examples of the wire harness according to the present disclosure will be described below with reference to the drawings. It should be noted that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications which fall within the scope of the claims and the meaning and scope of equivalents thereof. 
     Embodiment 
     A wire harness according to an embodiment will be described below. In the drawings, portions of configurations are shown exaggerated or simplified in some cases for convenience of description. Also, dimensional proportions of the portions may be different from the actual dimensional proportions in the drawings. Being “perpendicular” as used herein includes not only a state of being exactly perpendicular, but also a state of being substantially perpendicular. Being substantially perpendicular refers to, for example, a state in which an angle formed by two directions is greater than or equal to 80 degrees and less than 90 degrees, preferably greater than or equal to 85 degrees and less than 90 degrees. Being “parallel” as used herein includes not only a state of being exactly parallel, but also a state of being substantially parallel. Substantially parallel refers to, for example, a state in which an angle formed by two directions is 10 degrees or less, preferably 5 degrees or less. 
       FIG.  1    is a perspective view showing a wire harness  10  according to an embodiment.  FIG.  2    is a side view showing the wire harness  10  according to the embodiment.  FIG.  2    shows portions of devices B 1  and B 2  serving as mounting targets.  FIG.  3    is a front view showing the wire harness  10  according to the embodiment. 
     Overall Configuration of Wire Harness  10   
     An overall configuration of the wire harness  10  will now be described. The wire harness  10  includes a plurality of wires  20 , a first terminal block  30 , and a second terminal block  40 . The first terminal block  30  includes a first holding portion  31  and a plurality of first terminals  32 . The first holding portion  31  holds one end portions of the plurality of wires  20 . Each of the plurality of first terminals  32  is electrically connected to one end portion of the corresponding one of the plurality of wires  20 . The second terminal block  40  includes a second holding portion  41  and a plurality of second terminals  42 . The second holding portion  41  holds the other end portions of the plurality of wires  20 . Each of the plurality of second terminals  42  is electrically connected to the other end portion of the correspond one of the plurality of wires  20 . The plurality of wires  20  electrically connects the first terminal block  30  and the second terminal block  40  to each other. 
     The first terminal block  30  is fixed to a first device B 1 . The second terminal block  40  is fixed to a second device B 2 . The first device B 1  and the second device B 2  are electrically connected to each other via the wire harness  10 . That is, the plurality of wires  20 , the first terminal block  30 , and the second terminal block  40  constitute a wiring component that electrically connects the first device B 1  and the second device B 2  to each other. The devices B 1  and B 2  are in-vehicle devices. For example, the devices B 1  and B 2  are disposed in proximity to each other in a vehicle, and the wire harness  10  is formed relatively short. For example, the first device B 1  is an inverter, and the second device B 2  is a travel driving motor of an electric automobile or a hybrid vehicle. In the present embodiment, the plurality of wires  20  are high-voltage wires, and the first terminal block  30  and the second terminal block  40  are high-voltage terminal blocks. 
     The orientation of the wire harness  10  shown in  FIGS.  1  to  3    is a connection orientation. The connection orientation is an orientation of the harness  10  in a usage state. Here, the connection orientation is an orientation in a state in which the first terminal block  30  and the second terminal block  40  are respectively fixed to the first device B 1  and the second device B 2  disposed at predetermined positions of the vehicle. 
     The configurations of each of the portions will be described more specifically. 
     Wire  20   
     The plurality of wires  20  are arranged side by side between the first holding portion  31  and the second holding portion  41  in a direction intersecting a direction connecting the first holding portion  31  to the second holding portion  41 . One end portions of the plurality of wires  20  are held in a parallel state by the first holding portion  31 , and the other end portions of the plurality of wires  20  are held in a parallel state by the second holding portion  41 . Accordingly, portions of the plurality of wires  20  that are located between the first holding portion  31  and the second holding portion  41  are also held in a parallel state. In the present specification, as shown in  FIG.  1   , the side-by-side arrangement direction of the plurality of wires  20  in the first holding portion  31  may be referred to as an X direction, and two directions orthogonal to the X direction may be referred to as an Y direction and a Z direction. 
     In the connection orientation, the plurality of wires  20  are bent in a direction intersecting the side-by-side arrangement direction. The wire harness  10  is brought into the connection orientation by being bent from an orientation in which the plurality of wires  20  extend straight. The details of the orientations of the wire harness  10 , including the connection orientation, will be described later. 
     One end portions of the plurality of wires  20  are restrained by the first holding portion  31 , and make the same movement as the first holding portion  31  when the first holding portion  31  moves. The other end portions of the plurality of wires  20  are restrained by the second holding portion  41 , and make the same movement as the second holding portion  41  when the second holding portion  41  moves. Here, portions of the plurality of wires  20  that are located between the first holding portion  31  and the second holding portion  41  are not provided with any member that restrains the plurality of wires  20 . The first holding portion  31  and the second holding portion  41  have a higher rigidity than that of the wires  20 . When the first holding portion  31  and the second holding portion  41  move relative to each other, the wire harness  10  is deformed such that the wires  20  are bent. Portions of the plurality of wires  20  that are located between the first holding portion  31  and the second holding portion  41  make movements according to movements of the first holding portion  31  and the second holding portion  41 . When the first holding portion  31  and the second holding portion  41  move relative to each other, the mode of bending of the portions of the plurality of wires  20  that are located between the first holding portion  31  and the second holding portion  41  is determined by the rigidity or the like of the plurality of wires  20 . The portions of the plurality of wires  20  that are located between the first holding portion  31  and the second holding portion  41  may be provided with a member that restrains the plurality of wires  20 . 
     Here, the number of the plurality of wires  20  is six. However, the number of the plurality of wires  20  is not limited thereto, and may be set as appropriate according to devices to which they are to be connected, the use, and the like. For example, the number of the plurality of wires  20  may be two, or may be three. The number of the plurality of wires  20  may be more than three. The number of the plurality of wires  20  may be nine or less. 
     Here, the second device B 2  is an alternating-current motor, and the plurality of wires  20  transmit an alternating current. The alternating current may be a single-phase alternating current, or may be a multiphase alternating current. For example, six wires  20  may be used as two sets of three wires in order to accommodate a three-phase alternating current. However, the type of the power transmitted by the plurality of wires  20  can be set according to the devices B 1  and B 2  to which the wire harness  10  is connected, and the plurality of wires  20  may transmit a direct current. 
     Each of the plurality of wires  20  includes a stranded conductor  21  and an insulation covering  26  that covers the stranded conductor  21 . The stranded conductor  21  and the insulation covering  26  will be described with further reference to  FIGS.  4    to  6 .  FIG.  4    is a cross-sectional view showing a wire  20 .  FIG.  5    is an explanatory view showing an S-stranded conductor  21 .  FIG.  6    is an explanatory view showing a Z-stranded conductor  21 . Note that in  FIG.  4   , the stranding direction of each of the members is indicated by the arrow. In  FIGS.  5  and  6   , stranded conductors  21  each composed of two elemental wires  22  are shown for the ease of illustration. 
     Each stranded conductor  21  includes a plurality of elemental wires  22 . Each of the elemental wires  22  is made of copper, a copper alloy, aluminium, an aluminium alloy, or the like. The stranded conductor  21  is formed by a plurality of stranded elemental wires  22 . Here, the methods of stranding the plurality of elemental wires  22  include S-stranding and Z-stranding. The stranding directions of the plurality of elemental wires  22  in S-stranding and Z-stranding are opposite to each other. As shown in  FIG.  5   , S-stranding is a method in which, when the longitudinal direction of the stranded conductor  21  extends in the up-down direction, the elemental wires  22  extend in the form of a right-handed (clockwise) spiral from the upper side toward the lower side. As shown in  FIG.  6   , Z-stranding is a method in which, when the longitudinal direction of the stranded conductor  21  extends in the up-down direction, the elemental wires  22  extend in the form of a left-handed (counterclockwise) spiral from the upper side toward the lower side. In the following, an S-stranded conductor  21  and a wire  20  including the S-stranded conductor  21  may be denoted by reference numerals having a suffix “S”, and be referred to as a stranded conductor  21 S, and a wire  20 S, respectively. A Z-stranded conductor  21  and a wire  20  including the Z-stranded conductor  21  may be denoted by reference numerals having a suffix “Z”, and be referred to as a stranded conductor  21 Z and a wire  20 Z, respectively. When there is no need to distinguish between S-stranding and Z-stranding for a stranded conductor  21  and a wire  20 , the stranded conductor  21  and the wire  20  may be simply referred to as a stranded conductor  21  and a wire  20 , respectively. 
     There are two directions in which the stranded conductor  21  is twisted. One of the two directions is the same direction as a direction in which the plurality of elemental wires  22  are stranded, and the other of the two directions is a direction opposite to the direction in which the plurality of elemental wires  22  are stranded. When the stranded conductor  21  is twisted in the same direction as the direction in which the plurality of elemental wires  22  are stranded, the plurality of elemental wires  22  are tightened. When the stranded conductor  21  is twisted in a direction opposite to the direction in which the plurality of elemental wires  22  are stranded, the plurality of elemental wires  22  are loosened. The stranding directions of the plurality of elemental wires  22  of the stranded conductor  21 S and the stranded conductor  21 Z are opposite to each other. Therefore, when the stranded conductor  21 S and the stranded conductor  21 Z are twisted in the same direction, the plurality of elemental wires  22  of one of the stranded conductor  21 S and the stranded conductor  21 Z are tightened when the plurality of elemental wires  22  of the other are loosened, and vice versa. In other words, the stranded conductor  21 Z is loosened when twisted in the same direction as the direction in which the stranded conductor  21 S is tightened, and the stranded conductor  21 Z is tightened when twisted in the same direction as the direction in which the stranded conductor  21 S is loosened. 
     The cross-sectional area of the stranded conductor  21  is not particularly limited, and can be set as appropriate according to the device to which the stranded conductor  21  is to be connected, the current value, the voltage value, and so forth. Here, since the stranded conductor  21  is used as a high-voltage wire  20 , a stranded conductor having a relatively large diameter is used as the stranded conductor  21 . For example, the cross-sectional area of the stranded conductor  21  is 10 sq or more and 50 sq or less. sq is a standard for a conductor cross-sectional area defined in accordance with a JIS standard, and means a square mm. Within the range of a current that is allowed according to the cross-sectional area, the material, and the like of the conductor, the conductor may be used for various electricity transmission applications. 
     When the stranded conductor  21  has a large diameter, the number of elemental wires  22  may become large. When the number of elemental wires  22  becomes large, the stranded conductor  21  may have a so-called parent-child strand configuration. Specifically, a plurality of elemental wires  22  are divided into a plurality of groups each including two or more elemental wires  22 . In each of the groups, two or more elemental wires  22  are stranded into a child strand  23 . A plurality of child strands  23  are further stranded into a parent strand. The parent strand is used as a stranded conductor  21 . For example, in the example shown in  FIG.  4   , seven elemental wires  22  are stranded into a child strand  23 , and 19 child strands  23  are stranded into a stranded conductor  21  (parent strand). Note that, in the example shown in  FIG.  4   , the elemental wires  22  are depicted in one child strand  23 , and illustrations of the elemental wires  22  have been omitted in the other child strands  23 . Of course, the number of elemental wires  22  constituting each child strand  23 , and the number of child strands  23  constituting each stranded conductor  21  are not limited thereto, and can be set as appropriate. The stranded conductor  21  may not have a parent-child strand configuration. In the stranded conductor  21 , all the elemental wires  22  may be collectively stranded. 
     When the stranded conductor  21  has a parent-child strand configuration, the stranding direction of the child strands and the stranding direction of the parent strands may be the same, or may be different from each other. When the stranding direction of the child strands and the stranding direction of the parent strands are the same, the stranding direction is set as the stranding direction of the stranded conductor  21 . For example, as in the case of the example shown in  FIG.  4   , when the stranding direction of the child strands and the stranding direction of the parent strands are opposite to each other, the stranding direction of the parent strands is set as the stranding direction of the stranded conductor  21 . The reason is that the stranding direction of the parent strands is more closely related to the tightening and the loosening of the plurality of elemental wires  22  when the stranded conductor  21  is twisted, than the stranding direction of the child strands is. That is, whether the plurality of elemental wires  22  are tightened or loosened when the stranded conductor  21  is twisted mainly depends on the stranding direction of the parent strands. 
     The stranded conductor  21  may be a composite stranded conductor including a plurality of layers of parent strands in the radial direction. For example, in the example shown in  FIG.  4   , a set of six child strands  23 B and a set of twelve child strands  23 C are each stranded into a parent strand around one child strand  23 A disposed on the central axis. The six child strands  23 B constitute a first layer  24  on the inner side, and the twelve child strands  23 C constitute a second layer  25  on the outer side. All of the stranding directions of the parent strands of the layers may be the same, or the stranding directions of the parent strands of some layers may be opposite to the stranding directions of the parent strands of some other layers. For example, as in the example shown in  FIG.  4   , when all of the stranding directions of the parent strands of the layers are the same, the stranding direction is set as the stranding direction of the stranded conductor  21 . When the stranding directions of the parent strands of some layers are opposite to the stranding directions of the parent strands of some other layers, the stranding direction of the parent strands of the outermost layer is set as the stranding direction of the stranded conductor  21 . The reason is that the stranding direction of the parent strands of the outermost layer is more closely related to the tightening and the loosening of the plurality of elemental wires  22  when the stranded conductor  21  is twisted, than the stranding direction of the parent strands of a layer located inward of the outermost layer is. That is, whether the plurality of elemental wires  22  are tightened or loosened when the stranded conductor  21  is twisted mainly depends on the stranding direction of the parent strands of the outermost layer. 
     Each insulation covering  26  is made of an insulating resin, for example. Here, the insulation covering  26  is made of a crystalline resin. Such a crystalline resin may be, for example, a polyolefin-based resin such as polyethylene (PE) and polypropylene (PP). However, the insulation covering  26  may be made of an amorphous resin. Such an amorphous resin may be, for example, a polyamide-based resin such as nylon, or polyvinyl chloride or the like. 
     The hardness of the insulation covering  26  is not particularly limited, and can be set as appropriate according to the material and the thickness or the like. Here, the insulation covering  26  is formed relatively hard to the extent that does not make it difficult for the wire  20  to undergo bending deformation into the connection orientation. For example, the insulation covering  26  may have a Shore A hardness of 40 or more and 100 or less, as measured using a durometer compliant with JIS K 6253. 
     The insulation covering  26  may be formed, for example, by extrusion molding a softened resin material around the stranded conductor  21 . As shown in  FIG.  4   , such a resin material may fill the gaps between the parent strands of the outermost layer, and the entire inner surface of the insulation covering  26  may be in contact with the parent strands of the outermost layer. This reduces the room for the parent strands of the outermost layer to loosen, and the wire  20  is more likely to be twisted in the direction in which the stranded conductor  21  is tightened than in the direction in which the stranded conductor  21  is loosened. However, the insulation covering  26  may have a circular inner surface, and only a portion of the inner surface of the insulation covering  26  may be in contact with the parent strands of the outermost layer. In this case, another portion of the inner surface of the insulation covering  26  may not be in contact with the parent strands of the outermost layer, and a gap may be formed between the other portion of the inner surface of the insulation covering  26  and the parent strands of the outermost layer. 
     First Terminal Block  30   
     The first terminal  32  includes a first wire connection portion  32   a  and a first device connection portion  32   b . The first wire connection portion  32   a  is a portion that is connected to one end portion of each wire  20 . The first device connection portion  32   b  is a portion that is connected to the first device B 1 . For example, the first wire connection portion  32   a  is provided at one end portion of the first terminal  32 , and the first device connection portion  32   b  is provided at the other end portion of the first terminal  32 . The mode of connection between the first wire connection portion  32   a  and the wire  20  is not particularly limited, and can be set as appropriate. Examples thereof include crimping, ultrasonic welding, and resistance welding. The mode of connection between the first device connection portion  32   b  and the first device B 1  is not particularly limited, and can be set as appropriate. Examples thereof include fitting using a male terminal and a female terminal, and screwing. 
     The first holding portion  31  is made of resin, for example. The first holding portion  31  is formed by being molded using one end portions of the plurality of wires  20  as insert components. The first holding portion  31  is a resin molded portion insert-molded using the plurality of wires  20  as insert components. Here, the plurality of first terminals  32  are also used as insert components. Accordingly, the plurality of first terminals  32  are held in a parallel state by the first holding portion  31 . A connection portion between each first wire connection portion  32   a  and the corresponding wire  20  is provided inside the first holding portion  31 . Accordingly, at each of the one end portions of the plurality of wires  20 , a portion from which the insulation covering  26  has been detached for connection to the first wire connection portion  32   a  is covered and insulated by the first holding portion  31 . The first holding portion  31  is formed in a tubular shape, for example, and an opening  31   h  is formed inside the first holding portion  31 . The first device connection portion  32   b  extends in the opening  31   h.    
     The first terminal block  30  may be provided with a member such as a base member  33 , for example. The base member  33  is formed by pressing a metal plate, for example. An elliptic through hole is formed in a central portion of the base member  33 , and the first holding portion  31  is formed in a single piece with a peripheral edge portion of the through hole. 
     The base member  33  extends from an outer peripheral portion of the first holding portion  31 . While the base member  33  is in contact with a casing of the first device B 1 , the base member  33  is fixed to the first device B 1  through screwing or the like. The casing of the first device B 1  is grounded to the vehicle body. Accordingly, the base member  33  is grounded via the casing of the first device B 1 . In this manner, while the first terminal block  30  is fixed to the first device B 1 , the first device connection portion  32   b  is connected to a terminal of the first device B 1 . The first terminal block  30  may be provided with a shield shell or the like that is electrically connected to the base member  33 . 
     Second Terminal Block  40   
     The second terminal  42  includes a second wire connection portion  42   a  and a second device connection portion  42   b . The second wire connection portion  42   a  is a portion that is connected to the other end portion of each wire  20 . The second device connection portion  42   b  is a portion that is connected to the second device B 2 . For example, the second wire connection portion  42   a  is provided at one end portion of the second terminal  42 , and the second device connection portion  42   b  is provided at the other end portion of the second terminal  42 . The mode of connection between the second wire connection portion  42   a  and the wire  20  is not particularly limited, and can be set as appropriate. Examples thereof include crimping, ultrasonic welding, and resistance welding. The mode of connection between the second device connection portion  42   b  and the second device B 2  is not particularly limited, and can be set as appropriate. Examples thereof include fitting using a male terminal and a female terminal, and screwing. 
     The second holding portion  41  is made of resin, for example. The second holding portion  41  is formed by being molded using the other end portions of the plurality of wires  20  as insert components. The second holding portion  41  is a resin molded portion insert-molded using the plurality of wires  20  as insert components. Here, the plurality of second terminals  42  are also used as insert components. Accordingly, the plurality of second terminals  42  are held in a parallel state by the second holding portion  41 . A connection portion between each second wire connection portion  42   a  and the corresponding wire  20  is provided inside the second holding portion  41 . Accordingly, at each of the other end portions of the plurality of wires  20 , a portion from which the insulation covering  26  has been detached for connection to the second wire connection portion  42   a  is covered and insulated by the second holding portion  41 . The second holding portion  41  is formed in a tubular shape, for example, and an opening  41   h  is formed inside the second holding portion  41 . The second device connection portion  42   b  extends inside the opening  41   h.    
     Here, a portion from which the insulation covering  26  has been detached does not exist in a portion of each wire  20  that is located between the first holding portion  31  and the second holding portion  41 . The stranded conductor  21  is covered by the insulation covering  26  over the entire length and the entire circumference between the first holding portion  31  and the second holding portion  41 . The stranded conductor  21  is not exposed between the first holding portion  31  and the second holding portion  41 . 
     The second terminal block  40  may be provided with another member such as a fixing portion  43 . The fixing portion  43  is made of resin, for example. The fixing portion  43  is formed in a shape, such as a plate shape, that protrudes from the circumference of the second holding portion  41 . The fixing portion  43  is a resin portion molded separately from the second holding portion  41 , and may be combined with the second holding portion  41 . The fixing portion  43  may be molded in a single piece with the second holding portion  41 . 
     The fixing portion  43  is fixed to the second device B 2  through screwing or the like. In this case, a through hole for screwing is formed in the fixing portion  43 . A tubular collar may be embedded in the through hole. The collar may be made of a material, such as metal, that has high rigidity than the resin that forms the fixing portion  43 . 
     The fixing portion  43  may hold a plurality of relay terminals. One end portion of each of the relay terminals may be connected to the second device connection portion  42   b ,and the other end portion of each of the relay terminals may be connected to a terminal of the second device B 2 . Note that the second device connection portion  42   b  may be connected to the terminal of the second device B 2  without any relay terminal interposed therebetween. 
     Relationship Between Orientation of Wire Harness  10  and Stranding of Wires  20   
     The relationship between the orientation of the wire harness  10  and the stranding of the wires  20  will be described with further reference to  FIG.  7   .  FIG.  7    is a front view showing the wire harness  10  in a first orientation  11 . 
     As shown in  FIG.  7   , an orientation in which the plurality of wires  20  extend straight between the first holding portion  31  and the second holding portion  41  is defined as the first orientation  11  of the wire harness  10 . In the first orientation  11 , the first terminal block  30  and the second terminal block  40  are not shifted from each other in the X direction. The interval between the adjacent wires  20  in the first holding portion  31  and the interval between the adjacent wires  20  in the second holding portion  41  are the same. Accordingly, in the first orientation  11 , the plurality of wires  20  are close to a state of being precisely parallel. 
     The wire length between the first holding portion  31  and the second holding portion  41  is not particularly limited, and can be set as appropriate. The interval between the first holding portion  31  and the second holding portion  41  in the first orientation  11  is equal to the wire length between the first holding portion  31  and the second holding portion  41 . For example, the wire length between the first holding portion  31  and the second holding portion  41  may be 100 mm or more and 300 mm or less. When the wire length between the first holding portion  31  and the second holding portion  41  is short, the wire harness  10  is difficult to be bent. When the wire length between the first holding portion  31  and the second holding portion  41  is long, the effect of bending is less likely to be exerted on the portions restrained by the first holding portion  31  and the second holding portion  41 . 
     As described above, the orientation of the wire harness  10  shown in  FIGS.  1    to  3  is the connection orientation in which the first terminal block  30  and the second terminal block  40  are connected to the respective connection partners. The connection orientation is not the first orientation  11 , but a second orientation  12 . The second orientation  12  is an orientation in which the plurality of wires  20  are bent between the first holding portion  31  and the second holding portion  41 , and in which a twist occurs in the plurality of wires  20  when the plurality of wires  20  are bent from the first orientation  11 . 
     The second orientation  12  may be an orientation in which the plurality of wires  20  are bent about an axis extending in the side-by-side arrangement direction of the plurality of wires  20 , and in which one end portion and the other end portion of each of the plurality of wires  20  are shifted from each other in the side-by-side arrangement direction by an amount greater than or equal to the diameter of the wire  20 . Such a second orientation  12  is an orientation in which L-shaped bending and offset movement are combined. Specifically, in  FIG.  2   , the orientation of the wire harness  10  indicated by the dashed double-dotted line is the first orientation  11 , and the orientation of the wire harness  10  indicated by the solid line is the second orientation  12 . As indicated by the solid line in  FIG.  2   , in the second orientation  12 , the plurality of wires  20  are bent about an axis extending in the X direction. The plurality of wires  20  are bent in an L-shape. In  FIG.  3   , the orientation of the wire harness  10  indicated by the solid line is the second orientation  12 . In  FIG.  3   , the wire harness  10  indicated by the dashed double-dotted line shows a state in which one end portion and the other end portion of the wire  20  are not shifted from each other in the X direction. As indicated by the solid line in  FIG.  3   , in the second orientation  12 , one end portion and the other end portion of each of the plurality of wires  20  are shifted from each other in the X direction by an amount greater than or equal to the diameter of the wire  20 . The plurality of wires  20  make an offset movement in the side-by-side arrangement direction between the one end portions and the other end portions. 
     In the second orientation  12 , the angle formed by a direction in which the plurality of wires  20  extend from the first holding portion  31  and a direction in which the plurality of wires  20  extend from the second holding portion  41  may be 60 degrees or more and 120 degrees or less. Such an angle is the angle in a side view shown in  FIG.  2   .  FIG.  2    shows a case where the angle formed by the direction (the Z direction in  FIG.  2   ) in which the plurality of wires  20  extend from the first holding portion  31  and the direction (the Y direction in  FIG.  2   ) in which the plurality of wires  20  extend from the second holding portion  41  is perpendicular. In the second orientation  12 , the side-by-side arrangement direction of the plurality of wires  20  in the first holding portion  31  and the side-by-side arrangement direction of the plurality of wires  20  in the second holding portion  41  may be parallel to each other.  FIG.  1    shows a case where the side-by-side arrangement direction (the X direction in  FIG.  1   ) of the plurality of wires  20  in the first holding portion  31  and the side-by-side arrangement direction (the X direction in  FIG.  1   ) thereof in the second holding portion  41  are parallel to each other. 
     The stranding direction of the stranded conductors  21  of half or more of the plurality of wires  20  is a direction in which the stranding of the stranded conductors  21  is tightened by a twist occurring when the plurality of wires  20  are bent from the first orientation  11  to the second orientation  12 . Here, the stranding direction of the stranded conductors  21  of all of the plurality of wires  20  is a direction in which a twist occurring when the plurality of wires  20  are bent from the first orientation  11  to the second orientation  12  tightens the stranding of the stranded conductors  21 . 
     For example, the second orientation  12  shown in  FIG.  3    is an orientation in which the first holding portion  31  is shifted from the second holding portion  41  in the positive X direction when the wire harness  10  in the second orientation  12  is observed from the inner circumferential side relative to bending about an axis extending in the X direction, and also observed such that the first holding portion  31  is located above the second holding portion  41 . When the connection orientation of the wire harness  10  is the second orientation  12  shown in  FIG.  3   , the S-stranded wires  20  are oriented such that the stranding of the stranded conductors  21  is tightened by a twist occurring when the S-stranded wires  20  are bent from the first orientation  11  to the second orientation  12 , and the Z-stranded wires  20  are oriented such that the stranding of the stranded conductors  21  is loosened by a twist occurring when the Z-stranded wires  20  are bent from the first orientation  11  to the second orientation  12 . Therefore, when the connection orientation of the wire harness  10  is the second orientation  12  shown in  FIG.  3   , half or more of the wires  20  may be S-stranded wires  20 , and it is preferable that all of the wires  20  are S-stranded wires  20 . 
       FIG.  8    is a front view showing a wire harness  110  according to a first modification. 
     The orientation of the wire harness  110  in  FIG.  8    is a second orientation  112 . The second orientation  112  of the wire harness  110  shown in  FIG.  8    is different from the second orientation  12  of the wire harness  10  according to the embodiment. Specifically, the second orientation  112  of the wire harness  110  shown in  FIG.  8    is an orientation in which the wire harness  110  makes an offset movement in the X direction reversely to that in the second orientation  12  of the wire harness  10  according to the embodiment. The second orientation  112  shown in  FIG.  8    is an orientation in which the first holding portion  31  is shifted from the second holding portion  41  in the negative X direction when the wire harness  110  of the second orientation  112  is observed from the inner circumferential side relative to bending about an axis extending in the X direction, and also observed such that the first holding portion  31  is located above the second holding portion  41 . 
     When the connection orientation of the wire harness  110  is the second orientation  112  shown in  FIG.  8   , the S-stranded wires  20 S are oriented such that the stranding of the stranded conductors  21 S is loosened by a twist occurring when the S-stranded wires  20 S are bent from the first orientation  11  to the second orientation  112 , and the Z-stranded wires  20 Z are oriented such that the stranding of the stranded conductors  21 Z is tightened by a twist occurring when the Z-stranded wires  20 Z are bent from the first orientation  11  to the second orientation  112 . Therefore, when the connection orientation of the wire harness  110  is the second orientation  112  shown in  FIG.  8   , half or more of the wires  20  may be Z-stranded wires  20 Z, and it is preferable that all of the wires  20  are Z-stranded wires  20 Z. 
     The wire harnesses  10  and  110  are manufactured, for example, in the first orientation  11 , and are transported to locations where they are mounted to the devices B 1  and B 2 , while being in the first orientation  11 . Then, at the locations where the wire harnesses  10  and  110  are mounted to the devices B 1  and B 2 , the wire harnesses  10  and  110  are bent from the first orientation  11  to the second orientation  12  or  112  and mounted to the devices B 1  and B 2 . 
     Effects and so Froth 
     When the stranding direction of the stranded conductors  21  is a direction in which the stranding of the stranded conductors  21  is loosened by a twist occurring when the plurality of wires  20  are bent from the first orientation  11  to the second orientation  12  or  112 , the insulation coverings  26  impede loosening of stranding of the stranded conductors  21 , and therefore a strong force is required to bend the wires  20 . In this respect, with the wire harnesses  10  and  110  configured as described above, the stranding direction of the stranded conductors  21  is a direction in which the stranding of the stranded conductors  21  is tightened by a twist occurring when the plurality of wires  20  are bent from the first orientation  11  to the second orientation  12  or  112 . Therefore, the insulation coverings  26  are prevented from impeding loosening of the stranding of the stranded conductors  21 , thus making it possible to bend the wires  20  with a weak force. This makes it possible to facilitate bending of each of the wire harnesses  10  and  110  between one end and the other end thereof in a direction in which a twist occurs in the wires  20 . 
     Each of the second orientations  12  and  112  is an orientation in which the plurality of wires  20  are bent about an axis extending in a side-by-side arrangement direction, and in which one end portion and the other end portion of each of the plurality of wires  20  are shifted from each other in the side-by-side arrangement direction by an amount greater than or equal to the diameter of the wire  20 . When the plurality of wires  20  are bent from the first orientation  11  to such a second orientation  12  or  112 , a twist also occurs in the plurality of wires  20 . In this case as well, it is possible to facilitate bending of each of the wire harnesses  10  and  110  between one end and the other end thereof in a direction in which a twist occurs in the wires  20 . 
     In each of the second orientations  12  and  112 , an angle formed by a direction in which the plurality of wires  20  extend from the first holding portion  31  and a direction in which the plurality of wires  20  extend from the second holding portion  41  is 60 degrees or more and 120 degrees or less, and the side-by-side arrangement direction of the plurality of wires  20  in the first holding portion  31  and the side-by-side arrangement direction of the plurality of wires  20  in the second holding portion  41  are parallel to each other. In this case as well, it is possible to facilitate bending of each of the wire harnesses  10  and  110  between one end and the other end thereof in a direction in which a twist occurs in the wires  20 . 
     The stranding direction of the stranded conductors  21  of all of the plurality of wires  20  is a direction in which the twist occurring when the plurality of wires  20  are bent from the first orientation  11  to the second orientation  12  or  112  tightens the stranding of the stranded conductors  21 . With this configuration, none of the plurality of wires  20  is a wire  20  in which the stranding direction of the stranded conductor  21  is a direction in which the stranding of the stranded conductor  21  is loosened by a twist occurring when the plurality of wires  20  are bent from the first orientation  11  to the second orientation  12  or  112 , thus making it possible to facilitate bending of each of the wire harnesses  10  and  110  between one end and the other end thereof in a direction in which a twist occurs in the wires  20 . 
     The number of the plurality of wires  20  is three or more. In this case as well, it is possible to facilitate bending of each of the wire harnesses  10  and  110  between one end and the other end thereof in a direction in which a twist occurs in the wires  20 . 
     The insulation coverings  26  each have a Shore A hardness of 40 or more and 100 or less, as measured using a durometer compliant with JIS K 6253. In the case of a relatively hard insulation covering  26  having a Shore A hardness of 40 or more and 100 or less, fastening of the stranded conductors  21  by the insulation coverings  26  is further tightened, and the stranded conductors  21  are much less likely to be twisted in the direction in which they are loosened. In this case as well, the connection orientation is the orientation in which the stranded conductors  21  of half or more of the wires  20  are twisted in the direction in which they are tightened, and therefore each of the wire harnesses  10  and  110  is likely to assume the connection orientation. 
     The insulation coverings  26  are each made of a crystalline resin. With this configuration, the insulation coverings  26  are likely to be hard as compared with an insulation covering  26  made of an amorphous resin. In this case as well, the connection orientation is the orientation in which the stranded conductors  21  of half or more of the wires  20  are twisted in the direction in which they are tightened, and therefore the wire harnesses  10  and  110  are likely to assume the connection orientation. 
     The stranded conductors  21  each have a cross-sectional area of 10 sq or more and 50 sq or less, and the wire length between the first holding portion  31  and the second holding portion  41  is 100 mm or more and 300 mm or less. With this configuration, even in the case of using wires  20  having a relatively large diameter and a relatively short length, the connection orientation is an orientation in which the stranded conductors  21  of half or more of the wires  20  are twisted in the direction in which they are tightened, and therefore each of the wire harnesses  10  and  110  is likely to assume the connection orientation. 
     Each of the first holding portion  31  and the second holding portion  41  is a resin molded portion insert-molded using the plurality of wires  20  as insert components. With this configuration, each of the first holding portion  31  and the second holding portion  41  can firmly hold the plurality of wires  20 . In addition, one end portions of the plurality of wires  20  are likely to make the same movement as the first holding portion  31 , and the other end portions of the plurality of wires  20  are likely to make the same movement as the second holding portion  41 . 
     Appendix 
       FIG.  9    is a front view showing a wire harness  210  according to a second modification. 
     The wire harness  210  is different from the wire harnesses  10  and  110  described above in that a plurality of (two in this case) first terminal blocks  230  are provided. In this manner, the wires  20  may be branched due to the wire harness including one first terminal block or second terminal block, and a plurality of the other terminal blocks. In this case as well, when the plurality of wires  20  are arranged side by side, and the above-described relationship between the first orientation  11  and the second orientation  12  or  112  holds for at least one set of a first terminal block  230  and a second terminal block  40 , the same effects as the embodiment can be achieved. Note that in each of the first terminal blocks  230 , the number of first terminals  32  is three, and the first holding portion  231  is sized so as to accommodate the three first terminals  32 . The rest of the configuration of the first terminal block  230  may be the same as that of the first terminal block  30  described above. 
     Furthermore, the direction of twisting of the wires  20  may vary as in the case of the wire harness  210 . That is, in the wire harness  210 , one first terminal block  230 A is shifted in the positive X direction, and the other first terminal block  230 B is shifted in the negative X direction. In this case, of a plurality of (three in this case) wires  20  connecting one first terminal block  230 A to the second terminal block  40 , half or more of the wires  20  may be S-stranded wires  20 S, and it is preferable that all of the wires  20  are S-stranded wires  20 S, as in the case of the wire harness  10  according to the embodiment. Of a plurality of (three in this case) of wires  20  connecting the other first terminal block  230 B to the second terminal block  40 , half or more of the wires  20  may be Z-stranded wire  20 Z, and it is preferable that all of the wires  20  are Z-stranded wires  20 Z, as in the case of the wire harness  110  according to the first modification. 
     In addition, although the first holding portions  31  and  231  each have been described thus far as being a molded resin portion insert-molded using the wires  20  as insert components, this is not an essential configuration. For example, the first holding portions  31  and  231  may each be a separate molded article molded without using the wires  20  as insert components. For example, the first holding portion  31  may be a holding member formed by a bar-shaped member having formed therein grooves to which the wires  20  are to be fitted. Such a holding member is mounted to the wires  20  from a lateral side of the wires  20 . For example, the first holding portion  31  may be a housing having formed therein cavities into which the wires  20  are to be inserted. The wires  20  are inserted into the cavities of the housing from distal ends thereof. Members for fixing the wires  20 , such as rubber rings or back retainers, may be attached to the above-described holding member or housing. 
     Note that the configurations described in the embodiments and the modifications may be combined as appropriate as long as there are no mutual inconsistencies. 
     From the foregoing, it will be appreciated that various exemplary embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various exemplary embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims