Patent Description:
<CIT> (<CIT>) discloses a suspension member including a pair of side rails extending in a vehicle front-rear direction and a front cross member disposed between the side rails and extending in a vehicle-width direction. The suspension member is a vehicle structure that supports a suspension system (a suspension arm in particular) and is attached to a body of a vehicle from below, at a front portion of the vehicle.

Document <CIT> discloses a vehicle that is similar to that described by the preamble of independent claim <NUM>.

Depending on the layout of various types of parts in a front compartment, there are cases in which situating the front cross member on a downward side of the side rails is preferable. However, situating the front cross member on the downward side from the side rails may lead to functions as a reinforcing member that connects the side rails deteriorating, and rigidity of the suspension member may deteriorate.

A vehicle according to a first aspect of the present invention includes a body and a suspension member that is attached to a lower portion of the body at a vehicle-front side. The suspension member includes a pair of side rails extending in a front-rear direction of the vehicle. The suspension member includes a front cross member disposed between the side rails, and extending in a vehicle-width direction. The suspension member includes a pair of connecting members that connects the front cross member and the side rails. Each of the connecting members includes an upper plate, a lower plate, and a side plate. The upper plate is joined to an upper face of the side rail and projects from the side rail inward in the vehicle-width direction. The lower plate is joined to a lower face of the side rail and projects from the side rail inward in the vehicle-width direction. The side plate connects the upper plate and the lower plate that project from the side rail. The lower plate and an upper face of the front cross member are joined together.

The form of "joining" is not limited in particular, and may be performed by welding or fastening by bolts, for example. Also, "joining" is a concept including forms in which other parts, such as spacers, are interposed between the parts being joined.

In the vehicle described above, the lower plate of the connecting member is connected to the lower face of the side rail. Also, an upper face of the front cross member is joined to the lower plate of the connecting member. This enables the front cross member to be situated on the downward side from the side rails. The connecting member has a closed cross-sectional structure formed by the upper plate, the lower plate, and the side plate. The front cross member can be connected to the side rails via the closed cross-sectional structure, and accordingly sufficient rigidity can be ensured at the connecting portion. The position of the front cross member can be lowered relative to the side rails, while maintaining the function of the front cross member as a reinforcing member.

A bracket may further be provided that projects forward in the vehicle from the front cross member and that is configured to be capable of supporting a radiator. The bracket may include a plate member that is distanced from the front cross member and faces the front cross member, and also extends in the vehicle-width direction. A region of presence of the plate member in the vehicle-width direction may overlap at least part of a region of presence of the connecting member in the vehicle-width direction. With this configuration, rigidity of the front cross member in the region where the connecting member is present can be increased by the plate member. Sufficient rigidity of the connecting portion can be ensured.

A flange may be further provided, disposed at a distal end of the side rail in a vehicle-forward direction. The flange may be connected to the bracket. With this structure, an annular structure can be formed by the side rail, the flange, the bracket, the front cross member, and the connecting member. This enables rigidity of the connecting portion to be increased.

The upper plate may include a first region situated above the side rail and a second region projecting from the side rail inward in the vehicle-width direction. A prime mover mount may be further provided, disposed across the first region and the second region. The prime mover supported by the prime mover mount is not limited in particular. The prime mover is a concept that includes an electric motor, a motor unit in which an electric motor and a control unit are integrated, an engine, and so forth. With this structure, the connecting member can also function as a mechanism for supporting the prime mover mount.

The prime mover mount may be fastened to the side rail along with the upper plate. With this structure, the connecting member and the side rail can be firmly fixed by fastening the prime mover mount.

A vehicle <NUM> according to an embodiment will be described with reference to the drawings. "Front" in the coordinate system in <FIG> indicates a vehicle-forward direction. "Up" indicates a vehicle-upward direction. "Left" indicates left when viewing forward from a rearward side of the vehicle. The meanings of the axes in the coordinate system are the same in the following drawings as well. Note that the vehicle according to the present embodiment has a right-left symmetrical form, and accordingly, hereinafter only one side of the vehicle may be described in some cases.

As illustrated in <FIG>, the vehicle <NUM> includes a body <NUM> and a plurality of wheels 14f and 14r. A suspension member <NUM> is attached to a lower portion of the body <NUM>, at a vehicle-front side. The suspension member <NUM> is a structure that primarily supports a suspension system (a suspension arm in particular). A radiator <NUM> and a motor unit <NUM> are attached to the suspension member <NUM>. The motor unit <NUM> is a part in which a motor and a power control unit are integrated. The motor unit <NUM> drives at least one of the wheels 14f and 14r.

<FIG> is a top view of the suspension member <NUM>. <FIG> is a disassembled perspective view of the suspension member <NUM> at a vehicle front-right-side portion. The suspension member <NUM> includes a pair of side rails <NUM>, a front cross member <NUM>, a pair of connecting members <NUM>, a rear cross member <NUM>, a pair of fastening members <NUM> and <NUM>, a pair of flanges <NUM>, and a pair of brackets <NUM>. The side rails <NUM> have shapes that are symmetrical with each other in a right-left direction, and each extend along a front-rear direction of the vehicle. The front cross member <NUM> extends in a width direction of the vehicle, between the side rails <NUM>, at the front of the vehicle. The connecting members <NUM> connect the front cross member <NUM> and the side rails <NUM>. The rear cross member <NUM> connects the side rails <NUM> in the width direction of the vehicle, at the rear of the vehicle. Note that specific shapes and structures of the side rails <NUM> and the front cross member <NUM> are not limited in particular.

The fastening member <NUM> is a member that fixes a rear portion of the suspension member <NUM> to the body <NUM>. The fastening member <NUM> is a member that fixes a front portion of the suspension member <NUM> to a front side member (omitted from illustration). The suspension member <NUM> is fixed to a lower side of the body <NUM> in a suspended state by the fastening members <NUM> and <NUM>.

<FIG> is a schematic cross-sectional view taken along line IV-IV in <FIG> is a schematic cross-sectional view taken along line V-V in <FIG>. As illustrated in <FIG>, the connecting member <NUM> includes an upper plate 13U, a lower plate <NUM>, and side plates <NUM>. The upper plate 13U is joined to an upper face 11t of the side rail <NUM> and projects from the side rail <NUM> inward in the vehicle-width direction. The lower plate <NUM> is joined to a lower face 11b of the side rail <NUM> and projects from the side rail <NUM> inward in the vehicle-width direction. The side plates <NUM> connect the upper plate 13U and the lower plate <NUM> that are projecting from the side rail <NUM>. Also, the side plates <NUM> are joined to a side face <NUM> of the side rail <NUM> inward in the vehicle-width direction. Accordingly, the connecting member <NUM> has a closed cross-sectional structure formed by the upper plate 13U, the lower plate <NUM>, and the side plates <NUM>. The configuration is such that the upper plate 13U and the lower plate <NUM> sandwich the side rail <NUM> from above and below. Accordingly, strength of joining the side rail <NUM> and the connecting member <NUM> can be increased. An upper face 12t of the front cross member <NUM> is joined to a lower face of the lower plate <NUM>. Accordingly, the position of the front cross member <NUM> in the vehicle up-down direction can be situated on a downward side of the lower face 11b of the side rail <NUM>.

As illustrated in <FIG>, the upper plate 13U includes a first region R1 situated above the side rail <NUM> and a second region R2 projecting from the side rail <NUM> inward in the vehicle-width direction. Also, as illustrated in <FIG>, a motor mount <NUM> is disposed on the upper plate 13U, across the first region R1 and the second region R2. The motor mount <NUM> is a member for fixing the motor unit <NUM> to the suspension member <NUM>. Note that in <FIG>, the motor mount <NUM> is illustrated as a simplified plate member. The motor mount <NUM> is fastened to the side rail along with the upper plate 13U by bolts or the like, which are omitted from illustration. Accordingly, the connecting member <NUM> and the side rail <NUM> can be firmly fixed by fastening the motor mount <NUM> to the side rail <NUM>.

Note that various methods may be used to form the closed cross-sectional structure of the connecting member <NUM>. The method may be forming by combining members obtained by bending steel plates, and by welding the members together. The closed cross-sectional structure may be an integrally-formed part, created by carving or a 3D printer.

The connecting member <NUM> also is provided with an opening 13a at which no side plate <NUM> is disposed. Providing the opening 13a facilitates each process such as welding, fastening, and so forth. Assembly workability can be improved while maintaining strength.

The brackets <NUM> are members that are connected to a lower end of the radiator <NUM>, and support the radiator <NUM> from below. The two brackets <NUM> are provided right-left symmetrically at the front portion of the suspension member <NUM>. Each bracket <NUM> is fixed to the suspension member <NUM> and projects forward in the vehicle from the front cross member <NUM>. Each bracket <NUM> has a hole 21a.

The radiator <NUM> is a thin, substantially cuboid component that extends along the vehicle-width direction and the vehicle up-down direction. As illustrated in <FIG>, the radiator <NUM> has rubber bushes <NUM>. The rubber bushes <NUM> are provided right-left symmetrically at a lower portion of the radiator <NUM>. The positions of arranging the rubber bushes <NUM> correspond to the holes 21a of the brackets <NUM>.

Each bracket <NUM> has a plate member <NUM>. As illustrated in <FIG>, the plate member <NUM> has an L-shaped cross section, and has a lower face 22b and a side face <NUM>. Also, the front cross member <NUM> has a hat-shaped cross section and has a flange portion 12f projecting forward in the vehicle. The lower face 22b of the plate member <NUM> is joined to an upper face of the flange portion 12f. Accordingly, the side face <NUM> of the plate member <NUM> is disposed away from a side face <NUM> of the front cross member <NUM>, forward in the vehicle. Also, the side face <NUM> of the plate member <NUM> faces the side face <NUM> of the front cross member <NUM>, and is disposed extending in the vehicle-width direction.

Thus, in the cross section (see <FIG>) perpendicular to a longitudinal direction (vehicle-width direction) of the front cross member <NUM>, a member making up the cross section can be added by the plate member <NUM>. The cross-sectional shape can be made more complicated, and accordingly the moment of inertia of area of the front cross member <NUM> can be increased. As illustrated in <FIG>, a region of presence E1 of the plate member <NUM> in the vehicle-width direction overlaps at least part of a region of presence E2 of the connecting member <NUM> in the vehicle-width direction. Accordingly, rigidity of the front cross member <NUM> in the region where the connecting member <NUM> is present can be increased by the plate member <NUM>. Combining the bracket <NUM> and the plate member <NUM> enables improvement of rigidity of the connecting portion by the connecting member <NUM> while maintaining space conservation.

One flange <NUM> is disposed at each distal end of the side rails <NUM> in the vehicle-forward direction. A bumper reinforcement (omitted from illustration) is attached to the flange <NUM> via a crash box (omitted from illustration). Also, an end portion 17e of the flange <NUM> inward in the vehicle-width direction is connected to the bracket <NUM>.

With this structure, an annular structure can be formed by the side rail <NUM>, the flange <NUM>, the bracket <NUM>, the front cross member <NUM>, and the connecting member <NUM>. Rigidity of the connecting portion can be increased by the connecting member <NUM>.

Depending on the layout of various types of parts in a front compartment, situating the front cross member <NUM> on a downward side of the side rails <NUM> may be preferable. However, the front cross member <NUM> functions as a reinforcing member that connects the side rails <NUM> together. Accordingly, when the front cross member <NUM> is positioned on the downward side of the side rails <NUM>, there is a possibility that rigidity of the suspension member <NUM> may deteriorate. Accordingly, in the technology according to the present specification, the front cross structure is divided into a member extending in the vehicle-width direction (front cross member <NUM>), and a member connected to the side rail <NUM> (connecting member <NUM>). The connecting members <NUM> are joined to the sides of the side rails, and also the upper face of the front cross member <NUM> is joined to lower faces of the connecting members <NUM>. This enables the front cross member <NUM> to be situated on the downward side from the side rails <NUM>. Thus, the connecting member <NUM> has a closed cross-sectional structure formed by the upper plate 13U, the lower plate <NUM>, and the side plates <NUM>. The front cross member <NUM> can be connected to the side rails <NUM> via the closed cross-sectional structure, and accordingly, sufficient rigidity can be ensured at the connecting portion between the two. The position of the front cross member <NUM> can be lowered with respect to the side rails <NUM>, while keeping rigidity of the suspension member <NUM> from deteriorating. As a result, structures in a motor room can be arranged further downward, enabling design in which the center of gravity of the vehicle is lower, and the hood position is lower. Also, a vehicle with a smaller motor room and a shorter overhang can be realized, and accordingly increase in the size of the vehicle can be suppressed.

<FIG> is a schematic cross-sectional view taken along line VI-VI in <FIG>. <FIG> is a cross-sectional view in which the radiator <NUM>, the motor unit <NUM>, and a pipe <NUM> are installed. The pipe <NUM> connects the radiator <NUM> and the motor unit <NUM>. Also, a cross section of a front cross member <NUM> in a conventional structure is indicated by long dashed short dashed lines, and a cross section of the front cross member <NUM> according to the present embodiment is indicated by continuous lines. In comparison with the conventional front cross member <NUM>, the position of the front cross member <NUM> according to the present embodiment can be shifted downward in the vehicle up-down direction. Thus, an installation space MS for the pipe <NUM> can be formed, and accordingly the installation positions of the radiator <NUM>, the motor unit <NUM>, and the pipe <NUM> can be lowered. This enables the center of gravity of the vehicle to be lowered, and the size of the motor room to be reduced. Also, by lowering the installation positions of such equipment, workspace WS necessary for inspection and replacement work can be secured. Also, interference between the front cross member <NUM> and the radiator <NUM> can be averted, and accordingly a stroke ST for averting light collision damage can be secured.

As a comparative example, a case will be considered in which the height of the front cross member <NUM> is made lower than the height of the side rails <NUM>, without providing the connecting member <NUM>. In this state, when the motor mount <NUM> is disposed on the side rail <NUM>, the motor mount <NUM> needs to be supported by the upper face 11t of the side rail <NUM> alone. This makes the supporting area of the motor mount <NUM> small. On the other hand, the technology according to the present embodiment enables the connecting member <NUM> to function as a member for supporting the motor mount <NUM> as well. The motor mount <NUM> can be supported by the upper face 11t of the side rail <NUM> and the second region R2, and accordingly the supporting area of the motor mount <NUM> can be expanded. Thus, the motor unit <NUM> can be stably fixed.

Although a specific example of the technology disclosed in the present specification is described in detail above, this is only exemplary and is not intended to limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific example exemplified above. The technical elements described in the present specification or illustrated in the drawings exhibit technical utility solely or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technology exemplified in the present specification or in the drawings may achieve a plurality of objects at the same time, and has technical utility in itself by achieving one of the objects.

The vehicle structure according to the present embodiment is not limited to an electrified vehicle using an electric motor as a prime mover, and can also be suitably adopted to a vehicle that has an engine. Note that the term "electrified vehicle" here includes, for example, a rechargeable battery electric vehicle charged by an external power source, a fuel cell electric vehicle that uses a fuel cell as a power source, a hybrid electric vehicle that also has an engine, and so forth.

Claim 1:
A vehicle comprising:
a body (<NUM>); and
a suspension member (<NUM>) that is attached to a lower portion of the body (<NUM>), at a vehicle-front side,
the suspension member (<NUM>) including
a pair of side rails (<NUM>) extending in a front-rear direction of the vehicle,
a front cross member (<NUM>) disposed between the side rails (<NUM>), and extending in a vehicle-width direction, and
a pair of connecting members (<NUM>) that connects the front cross member (<NUM>) and the side rails (<NUM>), characterized in that
each of the connecting members (<NUM>) includes
an upper plate (13U) that is joined to an upper face of the side rail (<NUM>) and that projects from the side rail (<NUM>) inward in the vehicle-width direction,
a lower plate (<NUM>) that is joined to a lower face of the side rail (<NUM>) and that projects from the side rail (<NUM>) inward in the vehicle-width direction, and
a side plate (<NUM>) that connects the upper plate (13U) and the lower plate (<NUM>) that project from the side rail (<NUM>), wherein
the lower plate (<NUM>) and an upper face of the front cross member (<NUM>) are joined together.