Vehicular front wheel suspension structure

Abstract

To protect a cross member main body when a collision of a front section occurs.SOLUTION: A vehicular front wheel suspension structure includes: a pair of first load transmitting members 16 which is placed in a cross member main body 20 so as to be spaced apart from each other in the vehicle widthwise direction, and which extends in the vehicle back-and-forth direction at the internal side in the vehicle widthwise direction relative to a pair of lower arms 14; and a pair of second load transmitting members 18 which extends toward the rear side of a vehicle from a rear plate 2008 of the cross member main body 20 directed backwardly, and which is coupled to a member located at the rear side relative to the cross member main body 20. The pair of first load transmitting members 16 has respective front ends 1604 placed so as to face respective rear ends 2202 of a pair of sub frames 22 in the vehicle back-and-forth direction in the vicinity of the respective rear ends 2202 of the pair of sub frames 22, and has respective rear ends 1606 placed in the vicinity of the rear plate 2008 of the cross member main body 20. The pair of second load transmitting members 18 is placed at positions so as to face the respective rear ends 1606 of the pair of first load transmitting members 16.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a front wheel suspension structure for a vehicle. [Background technology]

[0002] A structure has been proposed in which front wheels are swingably supported via a pair of lower arms and a power train such as an engine or a motor is supported using a cross member body of a suspension cross member (see Patent Document 1). In this structure, cross member side mounting portions provided on both sides of the cross member body in the vehicle width direction are attached to side frames, which are body frame members on both sides in the vehicle width direction. In response to the increasing size and weight of the powertrain, it is conceivable to provide a pair of front side members extending forward of the vehicle from a point on the cross member body forward of the point where the pair of lower arms are attached to the cross member body, position the powertrain between this pair of front side members, and support the powertrain with the pair of front side members. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-172481 Summary of the Invention [Problem to be solved by the invention]

[0004] In the event of a frontal collision on a vehicle equipped with a cross member body supporting such a powertrain, if the weight of the powertrain increases, the collision load input from the pair of front side members to the cross member body due to the frontal collision will increase. Since the load transmission path of the collision load input to the cross member body is limited to the path that is transmitted from the cross member side mounting portions on both sides of the cross member body to a pair of side frames, this is disadvantageous in terms of efficiently transmitting the collision load input to the cross member body to the vehicle body, increases the load on the cross member body, and there is room for improvement in terms of protecting the cross member body. The present invention has been made in view of the above circumstances, and has as its object to provide a front wheel suspension structure for a vehicle that is advantageous in protecting a cross member body in the event of a frontal collision. [Means for solving the problem]

[0005] In order to achieve the above object, one embodiment of the present invention is a front wheel suspension structure for a vehicle comprising: a cross member main body that extends in a vehicle width direction and is attached to a pair of side frames that form vehicle frame members on both sides in the vehicle width direction; a pair of lower arms that extend outward in the vehicle width direction from both sides of the cross member main body in the vehicle width direction and support front wheels; and a pair of subframes that extend forward of the vehicle from front ends of both sides of the cross member main body in the vehicle width direction, the pair of subframes being spaced apart in the vehicle width direction inside the cross member main body and extending in the vehicle front-rear direction on the inside of the pair of lower arms in the vehicle width direction. and a pair of second load transmission members that extend toward the rear of the vehicle from a rear plate portion of the cross member main body facing rearward and are connected to a member rearward of the cross member main body, wherein the pair of first load transmission members have their front ends adjacent to the rear ends of the pair of subframes and are positioned opposite the rear ends of the pair of subframes in the fore-and-aft direction of the vehicle, and their rear ends are positioned adjacent to the rear plate portion of the cross member main body, and the pair of second load transmission members are positioned opposite the rear ends of the pair of first load transmission members in the fore-and-aft direction of the vehicle. In addition, one embodiment of the present invention is characterized in that pipe nuts are provided inside the cross member body on both sides in the vehicle width direction, each with its axis facing in the vertical direction, for attaching vehicle components placed on the upper part of the cross member body, and both ends of the pipe nuts in the axial direction are joined to the upper and lower surfaces of the cross member body, and the first load transmission member and the pipe nuts are integrally connected. In addition, one embodiment of the present invention is characterized in that multiple pipe nuts are arranged in a row at intervals in the fore-and-aft direction of the vehicle, and the first load transmission member extends in the fore-and-aft direction of the vehicle so as to connect the multiple pipe nuts. In addition, one embodiment of the present invention is characterized in that the first load transmission member includes an upper plate and a lower plate whose cross section across the longitudinal direction extends in the vehicle width direction, and side plates that vertically connect the upper plate and the lower plate, and the pipe nut is connected to the first load transmission member while penetrating the upper plate and the lower plate of the first load transmission member. In addition, one embodiment of the present invention is characterized in that the subframe is positioned opposite the lower arm in the vehicle fore-and-aft direction, and its rear end extends more inward in the vehicle width direction than the lower arm, and is positioned opposite the front end of the first load transmission member in the vehicle fore-and-aft direction. In addition, one embodiment of the present invention is characterized in that the lower arm is connected to the cross member main body at two front and rear connection portions, a front connection portion and a rear connection portion, and the first load transmission member is arranged adjacent to the rear connection portion on the inner side in the vehicle width direction. In addition, one embodiment of the present invention is characterized in that a bracket is provided on the vehicle widthwise inner side of the rear connecting portion of the lower arm of the cross member main body, which has a vertical wall facing the rear connecting portion across the first load transmission member, and connects the upper surface and the lower surface of the cross member main body. In addition, one embodiment of the present invention is characterized in that the vehicle is provided with a floor cross member extending in the vehicle width direction on the underside of the floor panel, and the second load transmission member is connected to the floor cross member. In addition, one embodiment of the present invention is characterized in that the vehicle is provided with a battery pack that stores a battery module behind the floor cross member, the second load transmission member extends rearward beyond the floor cross member, and the front of the battery pack is supported by the second load transmission member. [Effects of the Invention]

[0006] According to one embodiment of the present invention, in the event of a frontal collision, a collision load input to the cross-member body is transmitted to the vehicle body via the points where both sides of the cross-member body are attached to the pair of side frames. In addition, the collision load can be efficiently transmitted to components rearward of the cross-member body via another load transfer path including the first load transfer members and the second load transfer members. In particular, because the pair of second load transfer members are positioned opposite the rear ends of the pair of first load transfer members in the vehicle longitudinal direction, the collision load is reliably transmitted from the first load transfer members to the second load transfer members, which is advantageous for efficiently transmitting the collision load to components rearward of the cross-member body. Therefore, even if the cross-member body supports a heavy powertrain and a large collision load is input to the cross-member body during a frontal collision, the collision load can be efficiently transmitted to the vehicle body via the another load transfer path including the first load transfer members and the second load transfer members, which is advantageous for protecting the cross-member body. In addition, inside the cross member body, pipe nuts are provided on both sides in the vehicle width direction, each with its axis facing up and down, for attaching on-board equipment placed on the top of the cross member body, and both ends of the pipe nuts in the axial direction are joined to the upper and lower surfaces of the cross member body, so that when the first load transmission member and the pipe nuts are integrally connected, the first load transmission member is attached using a pair of pipe nuts for attaching the on-board equipment, and there is no need to add a new attachment structure for the first load transmission member, which is advantageous in reducing parts costs and facilitating the installation work of the first load transmission member. Furthermore, if multiple pipe nuts are arranged in a row at intervals in the fore-and-aft direction of the vehicle and the first load transmission member extends in the fore-and-aft direction of the vehicle to connect the multiple pipe nuts, the strength and rigidity of the first load transmission member is increased by the multiple pipe nuts, so that the transmission of collision load from the first load transmission member to the second load transmission member is more reliable, which is therefore more advantageous in efficiently transmitting the collision load to members rearward of the cross member main body. Furthermore, when the first load transmission member has a cross section across the longitudinal direction that includes upper and lower plates extending in the vehicle width direction, and side plates that connect the upper and lower plates vertically, and the pipe nut is connected to the first load transmission member while penetrating the upper and lower plates of the first load transmission member, the strength and rigidity of the first load transmission member is increased, thereby more reliably transmitting the collision load from the first load transmission member to the second load transmission member, and therefore providing greater advantages in efficiently transmitting the collision load to members rearward of the cross member main body. Furthermore, if the subframe is positioned opposite the lower arm in the fore-and-aft direction of the vehicle, and its rear end extends more inward in the vehicle width direction than the lower arm and is positioned opposite the front end of the first load transmission member in the fore-and-aft direction of the vehicle, an upper load transmission path can be secured from the rear end of the subframe, which is displaced toward the rear of the vehicle due to the input collision load, through the front end of the first load transmission member, which is more advantageous in efficiently transmitting the collision load to members rearward of the cross member main body. Furthermore, if the lower arm is connected to the cross member body at two connecting portions, a front connecting portion and a rear connecting portion, and the first load transmission member is positioned adjacent to the inside of the rear connecting portion in the vehicle width direction, the rear portion of the lower arm will abut against the first load transmission member due to the collision load input during a frontal collision, so that the first load transmission member supports the rear portion of the lower arm from the inside in the vehicle width direction, and the position of the rear connecting portion is restricted from displacing inward in the vehicle width direction. Therefore, the collision load is reliably transmitted from the rear plate portion of the cross member body to the second load transmission member along the direction connecting the front connecting portion and rear connecting portion of the lower arm, and the collision load is efficiently transmitted from the second load transmission member to members rearward of the cross member body. Furthermore, if a bracket is provided on the transversely inward side of the rear connecting portion of the lower arm of the cross member body, the bracket having a vertical wall facing the rear connecting portion across the first load transmission member and connecting the upper and lower surfaces of the cross member body, the impact load applied during a frontal collision will displace the lower arm rearward, causing the rear portion of the lower arm to displace inward in the transverse direction and abut against the first load transmission member, which will tend to displace inward in the transverse direction. At this time, the first load transmission member abuts against the vertical wall of the bracket, which supports the first load transmission member from the transversely inward side, restricting the first load transmission member from displacing inward in the transverse direction. Therefore, the first load transmission member can firmly absorb the collision load, and the collision load is efficiently transmitted from the first load transmission member to components rearward of the cross member body via the second load transmission member. In addition, if the vehicle is equipped with a floor cross member extending in the vehicle width direction on the underside of the floor panel, and the second load transmission member is connected to the floor cross member, this is advantageous in ensuring a load transmission path for transmitting the collision load from the second load transmission member to the floor cross member, and is advantageous in efficiently transmitting the collision load to the floor cross member. In addition, if the vehicle is equipped with a battery pack that stores a battery module behind the floor cross member, and the second load transmission member extends further rearward than the floor cross member and the front of the battery pack is supported on the second load transmission member, the front of the battery pack can be supported using the second load transmission member, which simplifies the battery pack mounting structure and is advantageous in reducing costs and facilitating the battery pack mounting work. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a plan view of a front wheel suspension structure for a vehicle according to an embodiment. [Figure 2] 1 is an enlarged plan view of a portion of a front wheel suspension structure for a vehicle according to an embodiment. [Figure 3] 1 is a side cross-sectional view of a front wheel suspension structure for a vehicle according to an embodiment. [Figure 4]1 is an enlarged plan view showing a main portion of a front wheel suspension structure for a vehicle according to an embodiment, with an upper plate of a cross member body removed. FIG. [Figure 5] 5 is a cross-sectional view taken along line AA in FIG. 4, showing the cross member body with the upper plate attached. [Figure 6] FIG. 5 is a perspective view of FIG. 4, showing a state in which an upper plate of the cross member body has been removed. [Figure 7] FIG. 2 is a perspective view of a first load transmission member. DETAILED DESCRIPTION OF THE INVENTION

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A front wheel suspension structure for a vehicle according to an embodiment of the present invention will now be described with reference to the drawings. In the following drawings, the symbol FR indicates the front of the vehicle, the symbol UP indicates the upper side of the vehicle, and the symbol LH indicates the width direction of the vehicle. In this embodiment, the vehicle is an electrically powered vehicle, such as an electric vehicle using only a motor as a drive source, a hybrid vehicle, or a plug-in hybrid vehicle (PHEV) that can be externally charged or externally powered, and the powertrain 30 described below will be described as including, for example, a motor and a transaxle. The present invention is also naturally applicable to vehicles using only an internal combustion engine as a drive source, in which case the powertrain 30 described below will include, for example, an engine and a transmission.

[0009] As shown in Figure 1, the vehicle front wheel suspension structure 10 of the embodiment is configured to include a suspension cross member 12, a pair of lower arms 14, a pair of first load transmission members 16, and a pair of second load transmission members 18. In this embodiment, the suspension cross member 12 is configured to include a cross member main body 20, a pair of sub-frames 22, and a front cross member 24.

[0010] As shown in Figures 1 and 3, the cross member body 20 is formed by joining an upper plate 20A that forms the upper half and a lower plate 20B that forms the lower half, and is provided so as to extend in the vehicle width direction. As shown in Figure 2, the cross member main body 20 is attached at both ends in the vehicle width direction near the ends in the vehicle fore-and-aft direction via a main body front mounting portion 26 and a main body rear mounting portion 28 to side frames (not shown) extending in the vehicle fore-and-aft direction, which form vehicle frame members located above the cross member main body 20. The cross member main body 20 also includes an upper plate portion 2002 consisting of an upper plate 20A facing upward, a lower plate portion 2004 consisting of a lower plate 20B facing downward, a front plate portion consisting of the upper plate 20A and the lower plate 20B facing toward the front of the vehicle, a rear plate portion 2008 consisting of the upper plate 20A and the lower plate 20B facing toward the rear of the vehicle, and a pair of side plate portions 2010 consisting of the upper plate 20A and the lower plate 20B facing on both sides in the vehicle width direction. The pair of side plate portions 2010 are provided with openings (not shown) at the middle portion in the vehicle longitudinal direction, which are directed outward in the vehicle width direction and through which the pair of lower arms 14 are inserted.

[0011] As shown in FIG. 2, the lower arms 14 extend outward in the vehicle width direction from both sides of the cross member body 20 in the vehicle width direction and support the front wheels. In detail, the lower arm 14 supports a front wheel (not shown) at its outer end 14A in the vehicle width direction, and has a front connecting portion 14B and a rear connecting portion 14C spaced apart in the front-to-rear direction at its inner end in the vehicle width direction. The front connecting portion 14B and the rear connecting portion 14C of the lower arm 14 are inserted between the lower plate 20B and the upper plate 20A through the openings (not shown), and as shown in FIG. 4, the lower arm 14 is swingably connected to the cross member main body 20 via bushings 15A and 15B at the two front and rear connecting portions of the front connecting portion 14B and the rear connecting portion 14C.

[0012] The pair of subframes 22 extend forward of the vehicle from the front ends of both sides of the cross member main body 20 in the vehicle width direction, and more specifically, extend forward of the vehicle from a location on the front plate portion 2006 of the cross member main body 20, which is forward of the location where the pair of lower arms 14 are attached to the cross member main body 20. The pair of subframes 22 are positioned opposite the pair of lower arms 14 in the vehicle fore-and-aft direction, and their rear ends 2202 extend further inward in the vehicle width direction than the pair of lower arms 14, and are positioned opposite the front end 1604 of the first load transmission member 16 described later in the vehicle fore-and-aft direction. The front cross member 24 extends in the vehicle width direction and connects the front ends of a pair of front cross members 24 together. In this embodiment, the powertrain 30 is arranged in a space surrounded by a pair of subframes 22, a front cross member 24, and the cross member main body 20, and the powertrain 30 is supported by the pair of subframes 22, the front cross member 24, and the cross member main body 20 via mounting members not shown. In this embodiment, the powertrain 30 includes, for example, a motor and a transaxle that transmits the rotational driving force of the motor to the front wheels.

[0013] As shown in Figures 4, 5, and 6, the pair of first load transmission members 16 are arranged spaced apart in the vehicle width direction inside the cross member main body 20, extend in the fore-and-aft direction of the vehicle and are located inside the pair of lower arms 14 in the vehicle width direction, and are arranged adjacent to and inside the rear connecting portion 14C in the vehicle width direction. In detail, the pair of first load transmission members 16 are arranged inside the cross member main body 20, i.e., between the lower plate 20B and the upper plate 20A, on both sides in the vehicle width direction, extending in the fore-and-aft direction of the vehicle and attached to the lower plate 20B and the upper plate 20A. The first load transmission member 16 has a cross section across the longitudinal direction that includes an upper plate 16A and a lower plate 16B that extend in the vehicle width direction, and a side plate 16C that vertically connects the upper plate 16A and the lower plate 16B. In detail, the first load transmission member 16 comprises an upper plate 16A and a lower plate 16B that are elongated in the fore-and-aft direction of the vehicle and face each other in the up-and-down direction, and a side plate 16C that connects the outer ends of the upper plate 16A and the lower plate 16B in the vehicle width direction. Coaxial holes 1602 are formed through the front and front-rear intermediate portions of the upper and lower plates 16A and 16B, respectively, in the up-down direction.

[0014] As shown in Figure 5, inside the cross member main body 20, pipe nuts 32 are provided on both sides in the vehicle width direction, with their axes facing in the vertical direction, for attaching an on-board component (electric power steering device 34) placed on the top of the cross member main body 20. Multiple pipe nuts 32 are provided in a row at intervals in the fore-and-aft direction of the vehicle, and both ends of the pipe nuts 32 in the axial direction are joined to the upper and lower surfaces of the cross member main body 20, so that the first load transmission member 16 and the pipe nuts 32 are integrally connected. Specifically, a pair of pipe nuts 32 are attached by welding to holes 1602 in the upper plate 16A and the lower plate 16B, and therefore the pair of pipe nuts 32 are attached to the upper plate 16A and the lower plate 16B. In other words, the pipe nuts 32 are connected to the first load transmission member 16 while passing through the upper plate 16A and the lower plate 16B of the first load transmission member 16. In other words, the pair of pipe nuts 32 are used to attach the on-vehicle component (electric power steering device 34) shown in FIG. 2, and form the attachment portion 36 of the electric power steering device 34. Coaxial holes 2020 oriented in the vertical direction are provided in both the lower plate 20B and the upper plate 20A at the front and front-rear middle portions of both sides of the cross member body 20 in the vehicle width direction. The pair of first load transmission members 16 extend in the fore-and-aft direction of the vehicle so as to connect a plurality of pipe nuts 32, and the upper and lower parts of the pair of pipe nuts 32 are inserted into holes 2020 in the lower plate 20B and the upper plate 20A, and the upper and lower parts of the pair of pipe nuts 32 are welded to the lower plate portion 2004 consisting of the lower plate 20B and the upper plate portion 2002 consisting of the upper plate 20A around the holes 2020, thereby being arranged on the cross member main body 20. An electric power steering device 34 is disposed above the cross member body 20 via these pipe nuts 32 .

[0015] In this state, the first load transmission member 16 is disposed on the cross member body 20, and extends in the longitudinal direction of the vehicle. As shown in Figures 4 and 5, the pair of first load transmission members 16 have their front ends 1604 positioned close to the rear ends 2202 of the pair of subframes 22 and facing the rear ends 2202 of the pair of subframes 22 in the fore-and-aft direction of the vehicle, and the rear ends 2202 are positioned close to the rear plate portion 2008 of the cross member main body 20. In other words, the front ends 1604 of the pair of first load transmission members 16 are positioned adjacent to, with a gap between them, the front plate portion 2006 of the cross member main body 20 to which the rear end 2202 of the subframe 22 is connected. The rear ends 1606 of the pair of first load transmission members 16 are disposed adjacent to, and spaced apart from, a rear plate portion 2008 of the cross member main body 20 facing rearward. In this way, a gap is secured between the front ends 1604 of the pair of first load transmission members 16 and the front plate portion 2006, and a gap is secured between the rear ends 1606 of the pair of first load transmission members 16 and the rear plate portion 2008, thereby preventing the front ends 1604 of the first load transmission members 16 from coming into contact with the front plate portion 2006, or the rear ends 1606 of the first load transmission members 16 from coming into contact with the rear plate portion 2008, during driving, thereby preventing abnormal noise from being generated.

[0016] As shown in Figures 4, 5, and 6, a bracket 38 is provided in a location near the first load transmission member 16 located behind the two pipe nuts 32 that constitute the mounting portion 36 of the electric power steering device 34. A bracket 38 is provided on the vehicle widthwise inside of the rear connecting portion 14C of the lower arm 14 of the cross member main body 20, and the bracket 38 has a vertical wall 38B that faces the rear connecting portion 14C across the first load transmission member 16, connecting the upper and lower surfaces of the cross member main body 20. In detail, the bracket 38 includes a bottom wall 38A attached by welding to the lower plate portion 2004 of the cross member main body 20, a vertical wall 38B that stands up from the bottom wall 38A and passes near a location on the inside of the first load transmission member 16 in the vehicle width direction, and an upper wall 38C that extends outward in the vehicle width direction from the upper end of the bulkhead vertical wall 38A, covers the upper plate 16A at the rear of the first load transmission member 16, and is attached by welding to the upper plate portion 2002 of the cross member main body 20. Therefore, the bracket 38 extends along the first load transmission member 16. The bracket 38 is provided to ensure the strength and rigidity of the portion 2030 of the cross member main body 20 (upper plate portion 2002) which constitutes the stabilizer mounting portion to which a bearing member is attached that swingably supports the middle portion of the stabilizer (neither of which is shown) which connects a pair of lower arms 14.

[0017] As shown in FIG. 4, the pair of second load transmission members 18 extend rearward from rear plate portions 2008 of the cross member body 20 facing rearward toward the rear of the vehicle, and are connected to members rearward of the cross member body 20. The pair of second load transmission members 18 are disposed at positions facing the rear ends 1606 of the pair of first load transmission members 16 in the vehicle longitudinal direction. In detail, the pair of second load transmission members 18 extend in the fore-and-aft direction of the vehicle, the front ends of the pair of second load transmission members 18 are attached by welding to a portion of the rear plate portion 2008 adjacent to the rear ends 1606 of the pair of first load transmission members 16, and the pair of second load transmission members 18 extend toward the rear of the vehicle from a portion of the rear plate portion 2008 adjacent to the rear ends 1606 of the pair of first load transmission members 16. As shown in FIG. 5, the second load transmitting member 18 is configured by joining an upper member 18A constituting an upper half thereof and a lower member 18B constituting a lower half thereof by welding. The second load transmission member 18 has a closed cross-sectional structure with a rectangular frame-like cross section, consisting of an upper plate portion 1802 and a lower plate portion 1804 that face each other in the vertical direction, and a pair of side plate portions 1806 that face each other in the vehicle width direction. A collar 40 having a bolt insertion hole 4002 extending vertically and welded to the upper plate portion 1802 and the lower plate portion 1804 is provided at the rear of the interior of the second load transmission member 18, and the tip of a bolt 42 inserted into the collar 40 from below the second load transmission member 18 is connected to a weld nut 48 provided on the bottom wall of a floor cross member 46 joined to the underside of the floor panel 44 and extending in the vehicle width direction, thereby connecting the rear of the second load transmission member 18 to the floor cross member 46. In other words, the vehicle is equipped with a floor cross member 46 extending in the vehicle width direction on the underside of the floor panel 44, and the second load transmission member 18 is connected to the floor cross member 46.

[0018] As shown in Figures 2 and 5, the front portions of the pair of second load transmission members 18 are provided with mounting portions 52 that are positioned at the rear of the vehicle of the cross member main body 20 and are used to attach a pair of battery pack side brackets 5002 at the front of the battery pack 50. This mounting portion 52 is configured to include a collar (not shown) having a bolt insertion hole extending vertically that is welded to the upper plate portion 1802 and the lower plate portion 1804, and a weld nut 54 (shown in Figure 2) that is welded to the upper plate portion 1802 and is coaxial with the bolt insertion hole. Therefore, by fastening the tip of the bolt that has passed through the bolt insertion hole and collar of the bracket 50 from below the bracket to the weld nut 54, a pair of battery pack side brackets 5002 at the front of the battery pack 50 are supported by a pair of second load transmission members 18. That is, the vehicle is equipped with a battery pack 50 that stores a battery module behind the floor cross member 46, and the second load transmission member 18 extends rearward beyond the floor cross member 46, with the front of the battery pack 50 supported by the second load transmission member 18. Inside the case of the battery pack 50 located behind the rear end of the second load transmitting member 18, a frame member (not shown) of the battery pack 50 that ensures strength and rigidity is arranged.

[0019] Next, the operation and effect when a frontal collision occurs in which an object collides with the front of the vehicle will be described. When a frontal collision occurs, the collision load is input to the cross member main body 20 via the front cross member 24 and a pair of subframes 22, and is then transmitted to the vehicle body via the first, second, and third load transmission paths described below.

[0020] (First load transfer path) The collision load input to the cross member body 20 is transmitted to the side frames via a front body mounting portion 26 and a rear body mounting portion 28 provided on both sides of the cross member body 20 in the vehicle width direction. The above load transfer path is the first load transfer path that has existed conventionally.

[0021] (Second load transfer path) During a frontal collision, the subframe 22 and powertrain 30 are displaced rearward of the vehicle due to the input collision load, and the front plate portion 2006 of the cross member main body 20 is also deformed and moved backward via the rear end 2202 of the subframe 22. Eventually, the front plate portion 2006 abuts against the front portion of the lower arm 14, and the collision load is transmitted along the direction connecting the front connecting portion 14B and the rear connecting portion 14C of the lower arm 14, and the collision load is transmitted from the rear plate portion 2008 of the cross member main body 20 to the floor cross member 46 via the second load transmission member 18. The above load transfer path is the second load transfer path.

[0022] (Third load path) In the event of a frontal collision, similarly to the above, the front plate portion 2006 of the cross member body 20 is deformed and moved backward via the rear end 2202 of the subframe 22, which is displaced rearward of the vehicle due to the input collision load. Eventually, the front plate portion 2006 abuts against the front end 1604 of the first load transmission member 16, and the collision load is transmitted along the extension direction of the first load transmission member 16.Furthermore, the rear end 1606 of the first load transmission member 16, which is displaced toward the rear of the vehicle due to the collision load, abuts against the rear plate portion 2008 of the cross member main body 20, and the collision load is transmitted to the second load transmission member 18 via the rear plate portion 2008, and the collision load is transmitted to the floor cross member 46 via the second load transmission member 18. The above load transfer path is the third load transfer path. By providing both the first load transmission member 16 and the second load transmission member 18 in this manner, it is possible to provide a second load transmission path and a third load transmission path in addition to the first load transmission path that has existed conventionally. Therefore, the collision load is transmitted to the vehicle body via a total of three load transmission paths, so that the collision load input to the cross member main body 20 during a frontal collision can be efficiently transmitted to the vehicle body.

[0023] According to this embodiment, the cross member has a pair of first load transmission members 16 that are arranged at intervals in the vehicle width direction inside the cross member main body 20 and extend in the fore-and-aft direction of the vehicle widthwise inward of the pair of lower arms 14, and a pair of second load transmission members 18 that extend toward the rear of the vehicle from a rear plate portion 2008 facing rearward of the cross member main body 20 and are connected to a member rearward of the cross member main body 20, and the pair of first load transmission members 16 have their front ends 1604 arranged close to the rear ends 2202 of a pair of subframes 22 and opposite the rear ends 2202 of the pair of subframes 22 in the fore-and-aft direction of the vehicle, and their rear ends 1606 are arranged close to the rear plate portion 2008 of the cross member main body 20, and the pair of second load transmission members 18 are arranged in a position opposite the rear ends 1606 of the pair of first load transmission members 16 in the fore-and-aft direction of the vehicle. Therefore, in the event of a frontal collision, the collision load input to the cross member main body 20 is transmitted to the vehicle body via the points where both sides of the cross member main body 20 are attached to a pair of side frames through the first load transfer path, and the collision load input to the cross member main body 20 can be efficiently transmitted to a member (floor cross member 46) rearward of the cross member main body 20 via the above-mentioned second and third load transfer paths, which include the first load transfer member 16 and the second load transfer member 18. In particular, since the pair of second load transmission members 18 are positioned opposite the rear ends 1602 of the pair of first load transmission members 16 in the fore-and-aft direction of the vehicle, the collision load is reliably transmitted from the first load transmission members 16 to the second load transmission members 18, which is advantageous in efficiently transmitting the collision load to the member (floor cross member 46) rearward of the cross member main body 20. Therefore, the cross member main body 20 supports the heavy powertrain 30, and even if a large collision load is input to the cross member main body 20 during a frontal collision, the collision load can be efficiently transmitted to the vehicle body via three load transmission paths including the first load transmission member 16 and the second load transmission member 18, which is advantageous in protecting the cross member main body 20.

[0024] In addition, in this embodiment, pipe nuts 32 are provided inside the cross member main body 20 on both sides in the vehicle width direction, with their axes facing in the vertical direction, for attaching an electric power steering device 34 placed on the top of the cross member main body 20, and both ends of the pipe nuts 32 in the axial direction are joined to the upper and lower surfaces of the cross member main body 20, so that the first load transmission member 16 and the pipe nuts 32 are integrally connected. Therefore, since the first load transmission member 16 is attached using a pair of pipe nuts 32 for attaching the electric power steering device 34, there is no need to add a new mounting structure for the first load transmission member 16, which is advantageous in reducing parts costs and facilitating the installation work of the first load transmission member 16.

[0025] In addition, in this embodiment, a plurality of pipe nuts 32 are arranged in a row at intervals in the vehicle longitudinal direction, and the first load transmission member 16 extends in the vehicle longitudinal direction so as to connect the plurality of pipe nuts 32. Therefore, the multiple pipe nuts 32 increase the strength and rigidity of the first load transmission member 16 against loads in the vehicle's fore-and-aft and width directions, so that the transmission of collision loads from the first load transmission member 16 to the second load transmission member 18 is more reliable, which is therefore more advantageous in efficiently transmitting the collision load to the member (floor cross member 46) rearward of the cross member main body 20.

[0026] In addition, in this embodiment, the first load transmission member 16 has a cross section across the longitudinal direction that includes an upper plate 16A and a lower plate 16B that extend in the vehicle width direction, and a side plate 16C that connects the upper plate 16A and the lower plate 16B vertically, and the pipe nut 32 is connected to the first load transmission member 16 in a state where it penetrates the upper plate 16A and the lower plate 16B of the first load transmission member 16. Therefore, since the pipe nut 32 is connected while penetrating the upper plate 16A and the lower plate 16B of the first load transmission member 16, the strength and rigidity of the first load transmission member 16 against loads in the fore-and-aft direction and the width direction of the vehicle is increased, so that the transmission of collision load from the first load transmission member 16 to the second load transmission member 18 is more reliable, and therefore it is more advantageous in efficiently transmitting the collision load to the member (floor cross member 46) rearward of the cross member main body 20.

[0027] In addition, in this embodiment, the subframe 22 is positioned opposite the lower arm 14 in the vehicle fore-and-aft direction, and its rear end 2202 extends further inward in the vehicle width direction than the lower arm 14, and is positioned opposite the front end 1604 of the first load transmission member 16 in the vehicle fore-and-aft direction. Therefore, in the event of a frontal collision, the above-mentioned third load transmission path can be secured, passing from the rear end 2202 of the subframe 22, which is displaced toward the rear of the vehicle due to the input collision load, through the front end 1604 of the first load transmission member 16, which is more advantageous in efficiently transmitting the collision load to the member (floor cross member 46) rearward of the cross member main body 20.

[0028] In addition, in this embodiment, the lower arm 14 is connected to the cross member main body 20 at two front and rear connection portions, the front connection portion 14B and the rear connection portion 14C, and the first load transmission member 16 is positioned adjacent to the rear connection portion 14C on the inner side in the vehicle width direction. Therefore, when the lower arm 14 is displaced rearward due to the collision load input during a frontal collision, a load acts on the rear connecting portion 14C of the lower arm 14 inward in the vehicle width direction, causing the rear portion of the lower arm 14 to tend to displace inward in the vehicle width direction. At this time, the rear portion of the lower arm 14 abuts against the first load transmission member 16, so that the first load transmission member 16 supports the rear portion of the lower arm 14 from the inside in the vehicle width direction, thereby restricting the position of the rear connecting portion 14C from displacing inward in the vehicle width direction. Therefore, the collision load is reliably transmitted from the rear plate portion 2008 of the cross member main body 20 to the second load transmission member 18 along the direction connecting the front connecting portion 14B and the rear connecting portion 14C of the lower arm 14, in other words, along the second load transmission path described above, and the collision load is efficiently transmitted from the second load transmission member 18 to the member (floor cross member 46) rearward of the cross member main body 20.

[0029] In addition, in this embodiment, a bracket 38 is provided on the vehicle widthwise inner side of the rear connecting portion 14C of the lower arm 14 of the cross member main body 20, which has a vertical wall 38B that faces the rear connecting portion 14C across the first load transmission member 16, and connects the upper and lower surfaces of the cross member main body 20. Therefore, the lower arm 14 is displaced rearward due to the collision load input during a frontal collision, and as a result, the rear portion of the lower arm 14 is displaced inward in the vehicle width direction.When the rear portion of the lower arm 14 comes into contact with the first load transmission member 16, the first load transmission member 16 attempts to displace inward in the vehicle width direction. At this time, the first load transmission member 16 abuts against the vertical wall 38B of the bracket 38, so that the bracket 38 supports the first load transmission member 16 from the inside in the vehicle width direction, thereby restricting the first load transmission member 16 from displacing inward in the vehicle width direction. Therefore, since the first load transmission member 16 can firmly absorb the collision load, the collision load is efficiently transmitted from the first load transmission member 16 via the second load transmission member 18 to the member (floor cross member 46) rearward of the cross member main body 20. As described above, the bracket 38 is an existing member that ensures the strength and rigidity of the portion 2030 of the cross member main body 20 (upper plate portion 2002) that constitutes the mounting portion of the stabilizer. Therefore, since there is no need to separately provide a dedicated reinforcing member, there is no need to reserve space in the cross member main body 20 for attaching a dedicated reinforcing member, which is advantageous in terms of saving space in the cross member main body 20.

[0030] In addition, in this embodiment, the vehicle is equipped with a floor cross member 46 extending in the vehicle width direction on the underside of the floor panel 44, and the second load transmission member 18 is connected to the floor cross member 46, which is advantageous in ensuring a load transmission path (the second and third load transmission paths described above) that transmits the collision load from the second load transmission member 18 to the floor cross member 46, which is a member rearward of the cross member main body 20, and is advantageous in efficiently transmitting the collision load to the floor cross member 46.

[0031] In addition, in this embodiment, the vehicle is equipped with a battery pack 50 that stores a battery module behind the floor cross member 46, and the second load transmission member 18 extends rearward beyond the floor cross member 46, and the front of the battery pack 50 is supported by the second load transmission member 18. Therefore, in a battery-equipped vehicle, the front of the battery pack 50 can be supported using the second load transmission member 18, which simplifies the mounting structure of the battery pack 50 and is advantageous in reducing costs and facilitating the installation work of the battery pack 50.

[0032] Furthermore, in this embodiment, the frame member of the battery pack 50 is arranged inside the case of the battery pack 50, which is located behind the rear end of the second load transmission member 18. Therefore, in the event of a frontal collision, if the second load transmission member 18 moves backward and its rear end abuts against the frame member via the case of the battery pack 50, the collision load will be transmitted rearward from the second load transmission member 18 to the frame member, which is advantageous in protecting the battery pack 50.

[0033] 10. Front wheel suspension structure of vehicle 12 Suspension cross member 14 Lower arm 14A End 14B Front connection part 14C Rear connection part 15A, 15B bushings 16 First load transmission member 16A Upper Plate 16B Lower plate 16C side plate 1602 hole 1604 Front end 1606 rear end 18 Second load transmission member 18A Upper member 18B Lower member 1802 Upper plate 1804 Lower plate part 1806 Side plate part 20 Cross member body 20A Upper Plate 20B Lower Plate 2002 Upper plate 2004 Lower plate part 2006 Front panel 2008 Rear plate part 2010 Side plate part 2020 hole 2030 locations 22 Subframe 2202 Rear end 24 Front cross member 26 Main unit front mounting part 28 Main unit rear mounting part 30 Powertrain 32 Pipe Nut 34 Electric power steering device 36 Mounting part 38 Bracket 38A bottom wall 38B vertical wall 38C upper wall 40 colors 4002 Bolt insertion hole 42 volts 44 Floor Panel 46 Floor cross member 48 Weld Nut 50 Battery Pack 5002 Battery pack side bracket 52 Mounting part 54 Weld Nut

Claims

1. a cross member body extending in a vehicle width direction and attached to a pair of side frames that form vehicle frame members on both sides in the vehicle width direction; a pair of lower arms extending outward in the vehicle width direction from both sides of the cross member body in the vehicle width direction and supporting front wheels; a pair of subframes extending forward from front ends of both sides of the cross member body in the vehicle width direction; A front wheel suspension structure for a vehicle comprising: a pair of first load transmission members that are arranged inside the cross member body at a spaced interval in the vehicle width direction and extend in the vehicle front-rear direction on the inner side of the pair of lower arms in the vehicle width direction; a pair of second load transmission members extending rearward from a rear plate portion of the cross member body toward the rear of the vehicle and connected to a member rearward of the cross member body; the pair of first load transmission members have front ends disposed adjacent to the rear ends of the pair of subframes and facing the rear ends of the pair of subframes in the vehicle longitudinal direction, and have rear ends disposed adjacent to the rear plate portion of the cross member main body, The pair of second load transmission members are disposed at positions facing rear ends of the pair of first load transmission members in the vehicle longitudinal direction. A front wheel suspension structure for a vehicle.

2. Inside the cross member body, pipe nuts are provided on both sides in the vehicle width direction, with their axes oriented in the up-down direction, for attaching on-vehicle parts placed on the upper part of the cross member body; The pipe nut has both axial ends joined to the upper and lower surfaces of the cross member body, The first load transmission member and the pipe nut are integrally connected.

2. The front wheel suspension structure for a vehicle according to claim 1.

3. A plurality of the pipe nuts are arranged at intervals in the front-rear direction of the vehicle, The first load transmission member extends in the vehicle front-rear direction so as to connect the plurality of pipe nuts.

3. The front wheel suspension structure for a vehicle according to claim 2.

4. The first load transmission member has a cross section taken along a longitudinal direction thereof that includes an upper plate and a lower plate extending in a vehicle width direction, and side plates that vertically connect the upper plate and the lower plate, The pipe nut is coupled to the first load transmission member while passing through the upper plate and the lower plate of the first load transmission member.

4. A front wheel suspension structure for a vehicle according to claim 2 or 3.

5. the subframe is disposed at a position facing the lower arm in the vehicle longitudinal direction, and has a rear end extending inward in the vehicle width direction relative to the lower arm, and is disposed at a position facing the front end of the first load transmission member in the vehicle longitudinal direction.

2. The front wheel suspension structure for a vehicle according to claim 1.

6. The lower arm is connected to the cross member body at two connecting portions, a front connecting portion and a rear connecting portion, The first load transmission member is disposed adjacent to the rear connecting portion on the inner side in the vehicle width direction.

2. The front wheel suspension structure for a vehicle according to claim 1.

7. A bracket is provided on the inside of the rear connecting portion of the lower arm of the cross member body in the vehicle width direction, the bracket having a vertical wall facing the rear connecting portion with the first load transmission member in between, and connecting the upper surface and the lower surface of the cross member body.

7. The front wheel suspension structure for a vehicle according to claim 6.

8. The vehicle includes a floor cross member extending in the vehicle width direction on the underside of a floor panel, The second load transmission member is connected to the floor cross member.

2. The front wheel suspension structure for a vehicle according to claim 1.

9. The vehicle includes a battery pack that houses a battery module behind the floor cross member, The second load transmission member extends rearward beyond the floor cross member, The front portion of the battery pack is supported by the second load transmission member.

9. The front wheel suspension structure according to claim 8.

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