JP2022112091A - Vehicle lower part structure - Google Patents

Abstract

To provide a vehicle lower part structure which can inhibit vibration of a suspension frame and a floor panel to improve steering stability and NV characteristics of a vehicle.SOLUTION: A vehicle lower part structure 100 includes: a floor panel 102 forming a floor surface of a vehicle; a front suspension frame 106 located at a front part of the floor panel; and floor side members 122, 124 fixed to the front suspension frame at an outer side in a vehicle width direction relative to a center in the vehicle width direction of the front suspension frame and extending to a vehicle rear. Each floor side member has at least two portions, a first portion 134, 136 and a second portion 138, 140 which are branched from the front suspension frame and extend to the vehicle rear. One of the at least two portions is branched from the suspension frame to the outer side in the vehicle width direction or an inner side in the vehicle width direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle undercarriage.

A vehicle such as an automobile includes a vehicle lower structure having, for example, a suspension frame of a front suspension, a front side member extending in the vehicle front-rear direction at the front of the vehicle, and a floor side member extending in the vehicle front-rear direction below the floor panel. . In such a vehicle lower structure, the suspension frame is supported by a plurality of members such as front side members and floor side members, thereby increasing the rigidity of the front portion of the vehicle and dispersing the impact transmitted to the front portion of the vehicle throughout the vehicle. to suppress vibration.

On the other hand, when the vehicle turns, vibrations and loads (for example, centrifugal force and inertial force) are generated in the vehicle width direction. By distributing the vibration and load in the vehicle width direction, for example, the vibration of the floor panel can be suppressed, the NV (Noise and Vibration) characteristics of the vehicle can be improved, and the steering stability of the vehicle can be enhanced. Therefore, it is required to disperse the vibration and load acting in the vehicle width direction of the vehicle lower structure.

Patent Document 1 describes a vehicle body structure including a suspension member 13 and a center side member 32 . The center side members 32 are arranged on the inside in the vehicle width direction of the side sills 29 arranged on the outside in the vehicle width direction. concatenate with

In Patent Document 1, the center side member 32 extends outward in the vehicle width direction toward the rear of the vehicle, and the strength of the center side member 32 is set to be greater than the strength of the side sill 29. The side members 32 improve the rigidity of the vehicle body.

JP 2013-63758 A

However, in the vehicle body structure of Patent Document 1, the front-rear extending portion 45 a of the suspension member 13 is connected to the center side member 32 . Therefore, the center side member 32 absorbs a load having a vehicle width direction component (vehicle centrifugal force, inertial force, etc.) and vibration transmitted to the suspension member 13 when the vehicle turns, to the front-rear extending portion 45 a of the suspension member 13 . will be received through However, Patent Literature 1 does not particularly devised to reduce the load and vibration. Therefore, vibration of the suspension member 13 (suspension frame) and the floor panel that occurs when the vehicle turns cannot be suppressed, and it is difficult to improve steering stability and NV characteristics of the vehicle.

SUMMARY OF THE INVENTION In view of such problems, an object of the present invention is to provide a vehicle lower structure capable of suppressing vibration of a suspension frame and a floor panel and improving steering stability and NV characteristics of the vehicle.

In order to solve the above problems, a typical configuration of a vehicle underbody structure according to the present invention is a vehicle underbody structure including a floor panel that forms a floor surface of the vehicle, and the vehicle underbody structure further includes a floor panel in front of the floor panel. and a floor side member fixed to the suspension frame outside the center of the suspension frame in the vehicle width direction and extending rearward of the vehicle, the floor side member branching off from the suspension frame and extending rearward of the vehicle. It has at least two extending portions, and one of the at least two portions is branched outwardly or inwardly in the vehicle width direction from the suspension frame.

ADVANTAGE OF THE INVENTION According to this invention, the vehicle lower part structure which can suppress the vibration of a suspension frame and a floor panel, and can improve the steering stability and NV characteristic of a vehicle can be provided.

1 is a bottom view showing a vehicle lower structure according to an embodiment of the present invention; FIG. It is a figure which shows the state which looked down on a part of vehicle lower part structure of FIG. 1 from the diagonally downward direction. It is a figure which shows the state which looked up at other part of vehicle lower part structure of FIG. 1 from the diagonally downward direction. It is a figure which shows the modification of the vehicle lower part structure of FIG. FIG. 3 is a diagram showing another modification of the vehicle lower structure of FIG. 1; FIG. 2 is a diagram showing still another modification of the vehicle lower structure of FIG. 1;

A typical configuration of a vehicle underbody structure according to an embodiment of the present invention is a vehicle underbody structure that includes a floor panel that forms a floor surface of the vehicle. a frame; and a floor side member fixed to the suspension frame outside the vehicle width direction center of the suspension frame and extending rearward of the vehicle, wherein at least two floor side members branch from the suspension frame and extend rearward of the vehicle. One of the at least two portions is branched outwardly or inwardly in the vehicle width direction from the suspension frame.

In the above configuration, the suspension frame is fixed to the floor side member. Therefore, the floor side member receives a load having a vehicle width direction component (vehicle centrifugal force, inertial force, etc.) and vibration acting on the suspension frame when the vehicle turns, for example. Therefore, the floor side member having the above configuration has at least two parts that branch from the suspension frame and extend rearward of the vehicle, one of which branches from the suspension frame to the outside in the vehicle width direction or the inside in the vehicle width direction. .

Therefore, in the floor side member, the load and vibration received from the suspension frame can be transmitted to at least two parts branching from the suspension frame and extending rearward of the vehicle, and can be efficiently dispersed rearward of the vehicle for release. In addition, if one part branches to the inside in the vehicle width direction and extends to the rear of the vehicle, the inside of the floor panel in the vehicle width direction is reinforced, so the floor vibration of the floor panel can be suppressed and the torsional rigidity can be increased. can do. On the other hand, if one part is inclined to the outside in the vehicle width direction and branches to the rear of the vehicle, the load and vibration can be released to the outside in the vehicle width direction. The inner portion of the floor panel in the vehicle width direction can be reinforced by the other portion located. Therefore, floor vibration and torsional vibration of the floor panel can be suppressed. Therefore, according to the above configuration, it is possible to suppress the vibration of the suspension frame and the floor panel that occurs when the vehicle turns, thereby improving the steering stability and NV characteristics of the vehicle.

The at least two parts of the floor side member are a first part that branches outward in the vehicle width direction from the suspension frame and has an arc shape projecting outward in the vehicle width direction, and a first part that branches inward in the vehicle width direction from the suspension frame. It is preferable to have a second portion that is arcuately convex inward in the width direction.

Thus, in the floor side member, the first portion and the second portion are arcuate. Note that the arc shape is not limited to a circular arc shape that is a part of a circle, but also includes an arc shape that is a part of an ellipse. Therefore, with the above configuration, it is possible to avoid local concentration of the vibrations and loads transmitted from the suspension frame to the first and second portions at the first and second portions. Transmission efficiency can be increased.

The end surface of the second portion is connected to the side surface of the first portion of the floor side member, and the second portion of the floor side member projects from the bottom surface toward the first portion and overlaps the bottom surface of the first portion. The lower surface of the first portion and the lower surface of the second portion are preferably inclined so as to become higher or lower as they approach the suspension frame.

Thus, in the floor side member, the end surface of the second portion is connected to the side surface of the first portion, and the lower surface of the first portion and the protruding portion projecting from the lower surface of the second portion toward the first portion are formed. By overlapping and connecting, the connection rigidity of the first part and the second part can be increased. The connection includes a form of joining each member and a form of tightening together with bolts.

Further, in the floor side member, the lower surface of the first portion and the lower surface of the second portion are inclined so that the lower surface of the first portion and the lower surface of the second portion become higher or lower as they approach the suspension frame. Suspension frame can be fixed at high or low position.

Further, as an example, the rear end portion of the lower surface of the first portion and the rear end portion of the lower surface of the second portion are different in height from the portion of the lower surface of the first portion and the lower surface of the second portion to which the suspension frame is fixed. assuming it is set to Even in such a case, in the above configuration, the lower surface of the first portion and the lower surface of the second portion are inclined so as to become higher or lower as they approach the suspension frame. The load and vibration can be efficiently transmitted toward the rear end portion and the rear end portion of the lower surface of the second portion.

The suspension frame described above preferably overlaps the projecting portion of the second portion of the floor side member, so that the first portion, the second portion of the floor side member, and the suspension frame are connected in an overlapping manner.

According to the above configuration, the suspension frame, the lower surface of the first portion of the floor side member, and the protruding portion of the second portion can be connected by, for example, overlapping and joining them together or fastening them together with a bolt or the like. . Therefore, the connection rigidity between the suspension frame and the first and second portions of the floor side member can be increased. In addition, since the suspension frame and the lower surface of the first portion of the floor side member and the protruding portion of the second portion of the floor side member are vertically overlapped and connected, the load and vibration from the suspension frame to the first portion and the second portion of the floor side member are prevented. is easier to convey.

The above vehicle lower structure further includes a side sill extending in the longitudinal direction of the vehicle along the edge of the floor panel, a front side member positioned in front of the side sill, and a torque box connecting the front side member and the side sill. , the floor side member may be connected to the torque box.

Thereby, the floor side member is connected not only to the suspension frame but also to the torque box that connects the front side member and the side sill. Therefore, the floor side member can transmit the load and vibration received from the suspension frame to the torque box, disperse them, and release them.

The vehicle lower structure further includes a side sill extending in the vehicle front-rear direction along the edge of the floor panel and disposed outside the first portion of the floor side member in the vehicle width direction, and a side sill below the floor panel in the vehicle width direction. and a rear side member extending forward from the rear end of the vehicle and connected to the lower cross member. The end portion may be connected to the vehicle width direction inner side surface of the side sill, and the rear end portion of the second portion may be connected to the lower cross member.

In this way, the floor side member has a first section branched from the suspension frame and the rear end of the first section is connected to the highly rigid side sill, and the rear end of the second section is connected to the lower cross member. Therefore, the floor side member can transmit the load and vibration received from the suspension frame to the side sill and the lower cross member via the first and second portions, disperse them, and release them to the entire vehicle. Moreover, since the first portion is connected to the side sill having high rigidity, vibration of the first portion can be suppressed.

As an example, when the rear end of the first section is connected not only to the side sill but also to the lower cross member, and the rear end of the second section is connected to the rear end of the first section, the The rear ends of the two parts are indirectly connected to the lower cross member. In this case, the floor side member can transmit and distribute the load and vibration not only to the lower cross member but also to the side sill via the second portion. Further, when the rear end of the second portion is directly connected to the lower cross member, the load and vibration of the floor side member are applied not only to the lower cross member but also to the rear side member through the second portion. can be transmitted and distributed.

The vehicle underbody structure further includes a center tunnel that protrudes upward in the vehicle longitudinal direction at the center of the floor panel in the vehicle width direction, and the second portion of the floor side member gradually approaches the center tunnel from the suspension frame. It is good to extend to the vehicle rear so that it may adjoin.

Thereby, the floor side member can distribute the load and vibration transmitted from the suspension frame to the second portion to the center tunnel. Therefore, floor vibration of the floor panel can be suppressed. Further, since the vibration surface of the floor panel can be divided in the vehicle width direction by the center tunnel, surface vibration of the floor panel can be suppressed. Note that the second part being adjacent to the center tunnel includes a form in which the second part is arranged close to the center tunnel without contacting it, or is in contact with or connected to the center tunnel.

The vehicle underbody structure further includes a bridge portion that is disposed inside the center tunnel and bridges the two side walls of the center tunnel in the vehicle width direction, and the bridge portion is positioned closest to the vehicle in the second portion of the floor side member. It is preferable that it is adjacent to a portion that protrudes inward in the width direction.

Thereby, the floor side member can transmit the load and vibration transmitted from the suspension frame to the second portion to the portion of the center tunnel having high rigidity due to the bridging portion disposed therein. In addition, the rigidity of the floor panel can be increased by arranging the bridging portion inside the center tunnel. Therefore, floor vibration of the floor panel can be suppressed.

The vehicle lower structure further includes an upper cross member extending in the vehicle width direction on the upper side of the floor panel. It is preferable that the portion projecting inward in the direction overlaps with the upper cross member through the floor panel and is joined to the lower surface of the upper cross member together with the floor panel.

Thus, the floor side member can distribute the load and vibration transmitted from the suspension frame to the first and second portions to the upper cross member. Moreover, since the first and second parts of the floor side member are connected by the upper cross member, the rigidity of each member can be increased, and vibration of each member can be suppressed.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these examples are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present invention are omitted from the drawings. do. In this embodiment, connection includes a mode in which the members to be connected are integrated with each other, and a mode in which separate members are joined together.

FIG. 1 is a bottom view showing a vehicle lower structure 100 according to an embodiment of the invention. In the drawing, the vehicle lower structure 100 is shown as viewed from below the vehicle. In each figure below, the front and rear directions of the vehicle are indicated by arrows Front and Back, the left and right directions of the vehicle width are indicated by arrows Left and Right, and the vertical directions of the vehicle are indicated by arrows Up and Down.

The vehicle undercarriage 100 includes a floor panel 102 forming the floor of the vehicle and a front suspension 104 . The front suspension 104 is composed of, for example, a front suspension frame 106 and a pair of suspension towers 108 and 110 .

The front suspension frame 106 is a member located in the front portion below the floor panel 102 and has a main body portion 112 , a pair of forward extension portions 114 and 116 , and a pair of rear extension portions 118 and 120 . The front extension portions 114 and 116 are portions extending forward of the vehicle from the body portion 112 on the outside of the body portion 112 in the vehicle width direction. The rear extension portions 118 , 120 are portions extending rearward of the vehicle from the body portion 112 on the outside of the body portion 112 in the vehicle width direction.

To the front suspension frame 106, a load having a vehicle width direction component (such as centrifugal force and inertial force of the vehicle) and vibration generated when the vehicle turns are transmitted. Therefore, in the vehicle lower structure 100, the load and vibrations that are transmitted to the front suspension frame 106 when the vehicle turns are efficiently dispersed toward the rear of the vehicle, and the inner side of the floor panel 102 in the vehicle width direction is reinforced. did.

Specifically, the vehicle lower structure 100 includes a pair of floor side members 122 and 124 . The floor side members 122 , 124 have suspension fixing portions 126 , 128 fixed to the front suspension frame 106 . Floor side members 122 and 124 receive loads and vibrations transmitted to front suspension frame 106 via suspension fixing portions 126 and 128 .

At suspension fixing portions 126 and 128 of floor side members 122 and 124, rear extension portions 118 and 120 positioned outside in the vehicle width direction of body portion 112 at the center of front suspension frame 106 in the vehicle width direction are provided. For example, the rear ends 130, 132 are fixed.

The floor side members 122,124 further have first portions 134,136 and second portions 138,140. The first parts 134, 136 and the second parts 138, 140 branch from the rear ends 130, 132 of the rear extensions 118, 120 of the front suspension frame 106 fixed to the suspension fixing parts 126, 128 and extend to the rear of the vehicle. This is the extended part.

The first portions 134 and 136 branch outward in the vehicle width direction from the rear ends 130 and 132 of the rear extension portions 118 and 120 of the front suspension frame 106 and form an arcuate shape projecting outward in the vehicle width direction. The second portions 138 and 140 branch inward in the vehicle width direction from the rear ends 130 and 132 of the rearward extension portions 118 and 120 of the front suspension frame 106 and form an arcuate shape that protrudes inward in the vehicle width direction. Note that the arc shape is not limited to a circular arc shape that is a part of a circle, but also includes an arc shape that is a part of an ellipse.

Therefore, in the vehicle lower structure 100, the load and vibration received by the floor side members 122 and 124 from the front suspension frame 106 via the suspension fixing portions 126 and 128 are transferred from the front suspension frame 106 to the first branch extending rearward of the vehicle. It can be transmitted to the parts 134, 136 and the second parts 138, 140 to effectively disperse and escape behind the vehicle. Further, in the vehicle lower structure 100, the second portions 138, 140 of the floor side members 122, 124 branch inward in the vehicle width direction and extend rearward of the vehicle, so that the inner side of the floor panel 102 in the vehicle width direction can be reinforced. can. Therefore, floor vibration of the floor panel 102 can be suppressed and torsional rigidity can be increased. Therefore, according to the vehicle lower structure 100, the vibration of the front suspension frame 106 and the floor panel 102 generated when the vehicle turns can be suppressed, and the steering stability and NV characteristics of the vehicle can be improved.

Also, in the vehicle undercarriage 100, the first portions 134, 136 and the second portions 138, 140 are arcuate. Therefore, vibrations and loads transmitted from the front suspension frame 106 to the first parts 134, 136 and the second parts 138, 140 via the suspension fixing parts 126, 128 are transferred to the first parts 134, 136 and the second parts 138 , 140 can be avoided, and the efficiency of vibration and load transmission can be improved.

The vehicle undercarriage 100 further comprises a pair of side sills 142,144 and a pair of front side members 146,148. The side sills 142, 144 extend in the vehicle front-rear direction along the edge of the floor panel 102 and are arranged outside the first portions 134, 136 of the floor side members 122, 124 in the vehicle width direction. The front side members 146, 148 are located in front of the vehicle relative to the side sills 142, 144 and extend in the longitudinal direction of the vehicle.

Vehicle undercarriage 100 further comprises a pair of torque boxes 150 , 152 and a connecting member 154 . Torque boxes 150 , 152 connect front side members 146 , 148 and side sills 142 , 144 . A connecting member 154 connects the torque boxes 150 and 152 together.

In the floor side members 122, 124, the front ends 156, 158 of the first parts 134, 136 straddle the joint surface 159 (see FIG. 2) between the torque boxes 150, 152 and the connecting member 154, and the torque box 150 is connected. , 152 and the connecting member 154 from below. Thereby, the connection rigidity between the torque boxes 150 and 152 and the connecting member 154 can be increased. In addition, vibrations and loads transmitted from the front suspension frame 106 to the first parts 134, 136 via the suspension fixing parts 126, 128 on either the left or right side are transferred from the front end parts 156, 158 of the first parts 134, 136. It can be dispersed and escaped to the torque boxes 150, 152 on the opposite side via the connecting member 154. FIG.

In the floor side members 122, 124, the front ends 160, 162 of the second parts 138, 140 connect the torque boxes 150, 152 from below. Therefore, in the floor side members 122, 124, the vibration and load transmitted to the second parts 138, 140 via the suspension fixing parts 126, 128 are transferred from the front ends 160, 162 of the second parts 138, 140 to torque boxes. It can be dispersed to 150, 152 and escaped.

Thus, in the floor side members 122, 124, the front ends 156, 158 of the first parts 134, 136 are connected to the torque boxes 150, 152 and the connecting member 154 at the suspension fixing parts 126, 128, and the second part 138 , 140 are connected to torque boxes 150,152. Therefore, in the floor side members 122, 124, the vibrations and loads transmitted to the first parts 134, 136 and the second parts 138, 140 via the suspension fixing parts 126, 128 are transferred to, for example, arrows A, B in FIG. As shown in FIG. 2, the air can be dispersed in four directions from the suspension fixing portions 126 and 128 and escaped.

Vehicle lower structure 100 further includes a lower cross member 164 and a pair of rear side members 166 , 168 . The lower cross member 164 extends in the vehicle width direction below the floor panel 102, is arranged behind the second portions 138, 140 of the floor side members 122, 124, and connects the side sills 142, 144 together. . Rear side members 166 , 168 extend forward of the vehicle from a rear end 170 of the vehicle and are connected to lower cross member 164 . The rear side members 166 and 168 are connected to a pair of suspension fixing portions 171 and 173 to which swinging suspensions for rear wheels (not shown) are fixed.

Rear end portions 172 , 174 of the first portions 134 , 136 of the floor side members 122 , 124 are connected to lateral inner side surfaces 176 , 178 of the side sills 142 , 144 and the lower cross member 164 . Rear ends 180, 182 of the second portions 138, 140 are connected to rear ends 172, 174 of the first portions 134, 136 and indirectly to the lower cross member 164 via these rear ends 172, 174. connected to

In this manner, the floor side members 122, 124 are connected to the highly rigid side sills 142, 144 at the rear ends 172, 174 of the first parts 134, 136 branched from the front suspension frame 106, and the second parts 138, 140 are indirectly connected to the lower cross member 164 at their rear ends 180 , 182 .

Therefore, the floor side members 122, 124 transmit the load and vibration transmitted from the front suspension frame 106 via the suspension fixing parts 126, 128 to the side sills via the first parts 134, 136 and the second parts 138, 140. 142, 144 and the lower cross member 164 to disperse and escape throughout the vehicle.

Further, since the first parts 134, 136 are connected to the side sills 142, 144 having high rigidity, vibration of the first parts 134, 136 can be suppressed. Further, floor side members 122, 124 are indirectly connected to lower cross member 164 at rear ends 180, 182 of second parts 138, 140, so that lower cross member 164 is moved through second parts 138, 140. Not only that, but also the side sills 142, 144 can transmit and distribute loads and vibrations.

Vehicle undercarriage 100 further comprises a center tunnel 184 , a bridge 186 and an upper cross member 188 . The center tunnel 184 protrudes upward in the longitudinal direction of the vehicle at the center of the floor panel 102 in the vehicle width direction. The bridge portion 186 is arranged inside the center tunnel 184 and bridges between the two side walls 190 and 192 of the center tunnel 184 in the vehicle width direction. The upper cross member 188 extends in the vehicle width direction above the floor panel 102 and connects the side sills 142, 144 to each other.

Second portions 138, 140 of floor side members 122, 124 branch off from front suspension frame 106 and extend rearward of the vehicle so as to gradually approach and adjoin center tunnel 184 as shown. Therefore, the floor side members 122 and 124 can transmit the load and vibration transmitted from the front suspension frame 106 to the second portions 138 and 140 via the suspension fixing portions 126 and 128 to the center tunnel 184 and disperse them. can. As a result, floor vibration of the floor panel 102 can be suppressed.

Further, since the vibration plane of the floor panel 102 can be partitioned in the vehicle width direction by the center tunnel 184, plane vibration of the floor panel 102 can be suppressed. Here, the second parts 138 and 140 are arranged close to the center tunnel 184 without being in contact with them as shown in the drawing, but they may be in contact with or connected to the center tunnel 184 without being limited to this.

The bridging portion 186 is adjacent to portions 194 and 196 of the second portions 138 and 140 of the floor side members 122 and 124 that protrude most inward in the vehicle width direction. As a result, the floor side members 122 and 124 transfer the load and vibration transmitted from the front suspension frame 106 to the second portions 138 and 140 via the suspension fixing portions 126 and 128 to the bridge portion 186 inside the center tunnel 184. can be transmitted to the part where is placed and the rigidity is high. Further, the rigidity of the floor panel 102 can be increased by arranging the bridging portion 186 inside the center tunnel 184 . Therefore, floor vibration of the floor panel 102 can be suppressed.

Furthermore, in the floor side members 122, 124, the portions 198, 200 of the first portions 134, 136 that project most outward in the vehicle width direction, and the second portions 138, 140 that project most inward in the vehicle width direction. The portions 194 and 196 overlap the upper cross member 188 through the floor panel 102 and are joined to the lower surface of the upper cross member 188 together with the floor panel 102 .

As a result, the floor side members 122, 124 absorb the load and vibration transmitted from the front suspension frame 106 to the first parts 134, 136 and the second parts 138, 140 via the suspension fixing parts 126, 128 to the upper cross member 188. can be transmitted and dispersed. Also, since the first parts 134, 136 and the second parts 138, 140 of the floor side members 122, 124 are connected by the upper cross member 188, the rigidity of each member can be increased, and vibration of each member can be suppressed. can be suppressed.

FIG. 2 is a diagram showing a state in which a portion of the vehicle lower structure 100 of FIG. 1 is viewed obliquely from below. The drawing shows the structure of the suspension fixing portion 126 of the floor side member 122 and its surroundings. Although illustration is omitted, the suspension fixing portion 128 of the floor side member 124 and its surroundings have the same configuration.

In floor side member 122 , end surface 204 of second portion 138 is connected to side surface 202 of first portion 134 . Further, the second portion 138 is formed with an overhang portion 208 that projects from the lower surface 206 toward the first portion 134 . The projecting portion 208 of the second portion 138 is connected to the lower surface 210 of the first portion 134 so as to overlap therewith. Further, the rear end portion 130 of the rear extension portion 118 of the front suspension frame 106 is connected to the overhanging portion 208 of the second portion 138 of the floor side member 122 as shown.

As a result, in the vehicle lower structure 100 , the lower surface 210 of the first portion 134 of the floor side member 122 , the projecting portion 208 of the second portion 138 , and the rear end portion of the rear extension portion 118 of the front suspension frame 106 are mounted on the suspension fixing portion 126 . 130 can be connected, for example, by overlapping and joining them or by tightening them together with bolts 212 or the like as shown.

Therefore, connection rigidity between the front suspension frame 106 and the first portion 134 and the second portion 138 of the floor side member 122 can be increased. Further, since the lower surface 210 of the first portion 134 of the floor side member 122, the projecting portion 208 of the second portion 138, and the rear end portion 130 of the rear extension portion 118 of the front suspension frame 106 are vertically stacked and connected, the front Load and vibration are easily transmitted from the suspension frame 106 to the first portion 134 and the second portion 138 of the floor side member 122 via the suspension fixing portion 126 .

The vehicle undercarriage 100 further comprises reinforcing members 214, 216 shown in dashed lines in the figure. Reinforcing members 214 and 216 are arranged inside first portion 134 of floor side member 122 at positions overlapping suspension fixing portion 126 in the vertical direction. Reinforcing members 214 and 216 function as wall surfaces inside first portion 134 and form a substantially rectangular parallelepiped closed cross-sectional structure together with side surface 202 and bottom surface 210 of first portion 134 and bottom surface 218 of floor panel 102 . In this way, in the floor side member 122, the reinforcing members 214 and 216 can form a closed cross-sectional structure inside the first portion 134, so that the rigidity around the suspension fixing portion 126 can be increased to suppress vibration. can.

FIG. 3 is a diagram showing another part of the vehicle lower structure 100 of FIG. 1 as seen from obliquely below. In the drawing, the configuration of the suspension fixing portion 128 of the floor side member 124 and its surroundings is shown. Although illustration is omitted, the suspension fixing portion 126 of the floor side member 122 and its surroundings have the same configuration.

In the floor side member 124, the lower surface 220 of the first portion 136 and the lower surface 222 of the second portion 140 extend from the rear end portion 174 of the first portion 136 and the rear end portion 182 of the second portion 140 to the front suspension. The rearward extension 120 of the frame 106 slopes down toward the rear end 132 . Dotted lines C and D in the drawing indicate the heights of the rear end portion 174 of the first portion 136 and the rear end portion 182 of the second portion 140, respectively.

In this way, in the floor side member 124 , the lower surface 220 of the first portion 136 and the lower surface 222 of the second portion 140 are inclined from the rear end portions 174 , 182 toward the front suspension frame 106 . Therefore, in the vehicle lower structure 100, the suspension fixing portion 128 can be set at the lowest position of the lower surface 220 of the first portion 136 and the lower surface 222 of the second portion 140. The suspension fixing portion 128 is attached to the front suspension frame 106. can be fixed. Also, the load and vibration transmitted from the front suspension frame 106 to the first portion 136 and the second portion 140 of the floor side member 124 via the suspension fixing portion 128 are transferred to the rear end portion 174 and the rear end portion 174 of the lower surface 220 of the first portion 136 . It can be efficiently transmitted toward the rear end portion 182 of the lower surface 222 of the second portion 140 .

Here, the lower surface 220 of the first portion 136 and the lower surface 222 of the second portion 140 of the floor side member 124 extend from the rear end portion 174 of the first portion 136 and the rear end portion 182 of the second portion 140 to the front suspension frame. 106 , it is inclined to be lower, but it is not limited to this, and may be inclined to be higher as it approaches the front suspension frame 106 . In this way, the suspension fixing portion 128 can be set at the highest position of the lower surface 220 of the first portion 136 and the lower surface 222 of the second portion 140, and the front suspension frame 106 is fixed to this suspension fixing portion 128. can do.

FIG. 4 is a diagram showing a modification of the vehicle lower structure 100 of FIG. A modified vehicle lower structure 100A differs from the above-described vehicle lower structure 100 in that it includes floor side members 122A and 124A and a lower cross member 164A.

Floor side members 122A, 124A have first portions 134A, 136A and second portions 138A, 140A. The first parts 134A, 136A and the second parts 138A, 140A branch from the rear ends 130, 132 of the rear extensions 118, 120 of the front suspension frame 106 fixed to the suspension fixing parts 126A, 128A and extend to the rear of the vehicle. This is the extended part.

The first parts 134A, 136A are integrated with the rear side members 166, 168 shown in FIG. As shown in FIG. 4, the first portions 134A and 136A branch outward from the front suspension frame 106 in the vehicle width direction and form an arcuate shape projecting outward in the vehicle width direction. , 144 to the rear of the vehicle. Parts 166A and 168A corresponding to parts of the rear side members 166 and 168 are connected to the first parts 134A and 136A and the lower cross member 164A as shown in FIG.

The lower cross member 164A extends in the vehicle width direction, and instead of the side sills 142, 144, connects the first portions 134A, 136A of the floor side members 122A, 124A. The second parts 138A, 140A are branched inwardly in the vehicle width direction from the front suspension frame 106 to form an arcuate shape projecting inwardly in the vehicle width direction. 164A directly.

Therefore, the load and vibration transmitted from the front suspension frame 106 to the second parts 138A, 140A of the floor side members 122A, 124A through the suspension fixing parts 126A, 128A are transferred to the rear ends 180A, 180A of the second parts 138A, 140A. Via 182A, it can be transmitted and distributed to the first parts 134A, 136A and the lower cross member 164A.

Furthermore, in the vehicle lower structure 100A, the load and vibration transmitted to the first portions 134A and 136A of the floor side members 122A and 124A are transmitted to the side sills 142 and 144 via the first portions 134A and 136A, and furthermore, the vehicle rear portion can be transmitted to Thus, in the vehicle lower structure 100A, the load and vibration received from the front suspension frame 106 are transmitted to the first portions 134A, 136A and the second portions 138A, 140A branched from the front suspension frame 106 and extending toward the rear of the vehicle. It can be efficiently dispersed behind the vehicle and escaped.

Further, in the vehicle lower structure 100A, the second portions 138A and 140A of the floor side members 122A and 124A branch inward in the vehicle width direction and extend rearward of the vehicle, so that the inner side of the floor panel 102 in the vehicle width direction can be reinforced. can. Therefore, floor vibration of the floor panel 102 can be suppressed and torsional rigidity can be increased. Therefore, according to the vehicle lower structure 100A, it is possible to suppress the vibration of the front suspension frame 106 and the floor panel 102 that occurs when the vehicle turns, and improve the steering stability and NV characteristics of the vehicle.

FIG. 5 is a diagram showing another modification of the vehicle lower structure 100 of FIG. A modified vehicle lower structure 100B differs from the above-described vehicle lower structure 100 in that floor side members 122B and 124B and a lower cross member 164B are provided.

Floor side members 122B, 124B have first portions 134B, 136B and second portions 138B, 140B. The first parts 134B, 136B and the second parts 138B, 140B are branched from the rear ends 130, 132 of the rear extensions 118, 120 of the front suspension frame 106 fixed to the suspension fixing parts 126B, 128B to the rear of the vehicle. This is the extended part.

The first parts 134B, 136B are integrated with the rear side members 166, 168 shown in FIG. As shown, the first portions 134B and 136B are branched outward from the front suspension frame 106 in the vehicle width direction to form an arcuate shape projecting outward in the vehicle width direction. extends to the rear of the vehicle along the

The lower cross member 164B extends in the vehicle width direction, and instead of the side sills 142, 144, connects the first portions 134B, 136B of the floor side members 122B, 124B. Lower cross member 164B also has opposite end portions 224 and 226 . Both ends 224 and 226 have a shape that expands in the vehicle front-rear direction toward the outside in the vehicle width direction as shown. Further, the second portions 138B, 140B are branched inwardly in the vehicle width direction from the front suspension frame 106 to form an arcuate shape projecting inwardly in the vehicle width direction. is directly connected to

Therefore, the load and vibration transmitted from the front suspension frame 106 to the second parts 138B, 140B of the floor side members 122B, 124B through the suspension fixing parts 126B, 128B are transferred to the rear ends 180B, 180B of the second parts 138B, 140B. 182B can be transmitted to both ends 224, 226 of the lower cross member 164B and distributed to the first portions 134B, 136B and the lower cross member 164B.

Furthermore, in the vehicle lower structure 100B, the load and vibration transmitted to the first portions 134B and 136B of the floor side members 122B and 124B are transmitted to the side sills 142 and 144 via the first portions 134B and 136B, and furthermore, the vehicle rear portion can be transmitted to Thus, in the vehicle lower structure 100B, the load and vibration received from the front suspension frame 106 are transmitted to the first portions 134B, 136B and the second portions 138B, 140B branched from the front suspension frame 106 and extending toward the rear of the vehicle. It can be efficiently dispersed behind the vehicle and escaped.

Further, in the vehicle lower structure 100B, the second portions 138B and 140B of the floor side members 122B and 124B branch inward in the vehicle width direction and extend rearward of the vehicle, so that the inner side of the floor panel 102 in the vehicle width direction can be reinforced. can. Therefore, floor vibration of the floor panel 102 can be suppressed and torsional rigidity can be increased. Therefore, according to the vehicle lower structure 100B, it is possible to suppress the vibration of the front suspension frame 106 and the floor panel 102 when the vehicle turns, thereby improving the steering stability and NV characteristics of the vehicle.

FIG. 6 is a diagram showing still another modification of the vehicle lower structure 100 of FIG. A modified vehicle lower structure 100C differs from the above-described vehicle lower structure 100 in that floor side members 122C and 124C and a lower cross member 164C are provided.

Floor side members 122C and 124C have center side members 228 and 230 in addition to first portions 134C and 136C and second portions 138C and 140C. The first parts 134C, 136C, the second parts 138C, 140C and the center side members 228, 230 are connected to the rear ends 130, 132 of the rear extensions 118, 120 of the front suspension frame 106 fixed to the suspension fixing parts 126C, 128C. branched from and extends rearward of the vehicle.

The first portions 134C, 136C branch outward in the vehicle width direction from the front suspension frame 106, incline linearly, and extend rearward of the vehicle along the side sills 142, 144 inside the side sills 142, 144 in the vehicle width direction. there is Rear end portions 232, 234 of the first portions 134C, 136C are connected to the side sills 142, 144 and the lower cross member 164C.

Therefore, the load and vibration transmitted from the front suspension frame 106 to the first parts 134C, 136C of the floor side members 122C, 124C via the suspension fixing parts 126C, 128C are transferred to the rear ends 232, 136C of the first parts 134C, 136C. 234 to side sills 142, 144 and lower cross member 164C for distribution.

The second parts 138C and 140C branch inward in the vehicle width direction from the front suspension frame 106, are linearly inclined, and extend rearward of the vehicle so as to be adjacent to the center tunnel 184. As shown in FIG. Rear end portions 180C and 182C of the second portions 138C and 140C are connected to the lower cross member 164C.

Therefore, the load and vibration transmitted from the front suspension frame 106 to the second parts 138C, 140C of the floor side members 122C, 124C through the suspension fixing parts 126C, 128C are transferred to the rear end part 180C of the second parts 138C, 140C. , 182C to the lower cross member 164C for distribution.

The center side members 228, 230 branch from the front suspension frame 106 between the first portions 134C, 136C and the second portions 138C, 140C, extend linearly toward the rear of the vehicle, and extend linearly outward in the vehicle width direction along the way. sloped. Rear end portions 236, 238 of the center side members 228, 230 are connected to the lower cross member 164C.

Therefore, the load and vibration transmitted from the front suspension frame 106 to the center side members 228, 230 of the floor side members 122C, 124C through the suspension fixing portions 126C, 128C are transferred to the rear end portions 236 of the center side members 228, 230. , 238 to the lower cross member 164C for distribution.

The center side members 228 and 230 branch from the front suspension frame 106 and linearly extend rearward of the vehicle, and are linearly inclined outward in the vehicle width direction. Instead of sloping outward, they may branch off from the front suspension frame 106 and extend straight to the rear ends 236,238.

The suspension fixing portions 126C, 128C are formed by stacking and joining the first portions 134C, 136C, the second portions 138C, 140C and the center side members 228, 230 in the vertical direction. Furthermore, the rear end portions 130, 132 of the rear extension portions 118, 120 of the front suspension frame 106 are superimposed on the suspension fixing portions 126C, 128C from below. Therefore, the suspension fixing portions 126C and 128C can fix the front suspension frame 106 by joining the front suspension frame 106 or tightening them together with bolts or the like.

Thus, in the vehicle lower structure 100C, the load and vibration transmitted from the front suspension frame 106 to the floor side members 122C and 124C via the suspension fixing portions 126C and 128C are branched from the front suspension frame 106 and extended toward the rear of the vehicle. It can be transmitted to the first parts 134C, 136C, the second parts 138C, 140C, and the center side members 228, 230 to efficiently disperse and escape to the rear of the vehicle.

Further, in the vehicle lower structure 100C, the second portions 138C and 140C of the floor side members 122C and 124C branch inward in the vehicle width direction and extend toward the rear of the vehicle, so that the inner side of the floor panel 102 in the vehicle width direction can be reinforced. can. Therefore, floor vibration of the floor panel 102 can be suppressed and torsional rigidity can be increased. Therefore, according to the vehicle lower structure 100C, it is possible to suppress the vibration of the front suspension frame 106 and the floor panel 102 when the vehicle turns, and improve the steering stability and NV characteristics of the vehicle.

In the vehicle lower structure 100C, the floor side members 122C and 124C are branched from the front suspension frame 106 into the first parts 134C and 136C, the second parts 138C and 140C, and the center side members 228 and 230. Not limited. As an example, the floor side members 122C, 124C may be branched from the front suspension frame 106 into first portions 134C, 136C and appropriate members such as center side members 228, 230 extending rearward of the vehicle. and second portions 138C and 140C.

That is, each floor side member 122, 124, 122A, 124A, 122B, 124B, 122C, 124C of the vehicle lower structures 100, 100A, 100B, 100C has at least two parts branching from the front suspension frame 106 and extending rearward of the vehicle. , and one of the at least two portions should be branched from the front suspension frame 106 outwardly or inwardly in the vehicle width direction. If this one part branches to the outside in the vehicle width direction, it is possible to release vibrations and loads to the outside in the vehicle width direction, and if it branches to the inside in the vehicle width direction, vibrations and loads can be released to the inside in the vehicle width direction. In addition, the inner side of the floor panel 102 in the vehicle width direction can be reinforced.

In the vehicle lower structures 100, 100A, 100B, and 100C, the floor side members 122, 124, 122A, 124A, 122B, 124B, 122C, and 124C are arranged on the lower surface of the floor panel 102. It may be arranged on the upper surface of the panel 102 . Further, the floor side members 122, 124, 122A, 124A, 122B, 124B, 122C, and 124C are configured as separate members, but the configuration is not limited to this, and the components may be integrated.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope described in the claims, and these also belong to the technical scope of the present invention. Understood.

INDUSTRIAL APPLICABILITY The present invention can be used for vehicle undercarriages.

100, 100A, 100B, 100C... vehicle lower structure, 102... floor panel, 104... front suspension, 106... front suspension frame, 108, 110... suspension tower, 112... main body, 114, 116... forward extension, 118, 120... rear extension parts 122, 122A, 122B, 122C, 124, 124A, 124B, 124C... floor side members 126, 126A, 126B, 126C, 128, 128A, 128B, 128C... suspension fixing parts 130, 132... Rear end portions of rear extension portions 134, 134A, 134B, 134C, 136, 136A, 136B, 136C... first portion, 138, 138A, 138B, 138C, 140, 140A, 140B, 140C... second portion, 142, 144... Side sill 146, 148... Front side member 150, 152... Torque box 154... Connecting member 156, 158... Front end of first part 159... Joint surface 160, 162... Front end of second part , 164, 164A, 164B, 164C... Lower cross member 166, 168... Rear side member 166A, 168A Rear side member parts 170... Rear end of vehicle 171, 173... Suspension fixing part 172, 174, 232, 234 176, 178 Rear end of the first portion 180, 180A, 180B, 180C, 182, 182A, 182B, 182C Rear end of the second portion 184 Center tunnel 186 Bridge portion , 188... Upper cross member 190, 192... Side wall of center tunnel 194, 196... Location of second part 198, 200... Location of first part 202... Side surface of first part 204... Second part end surface 206, 222 bottom surface of second part 208 projecting part of second part 210, 220 bottom surface of first part 212 bolt 214, 216 reinforcing member 218 bottom surface of floor panel 224, 226... both ends of lower cross member, 228, 230... center side member, 236, 238... rear end of center side member

Claims (9)

A vehicle undercarriage comprising a floor panel forming a floor of the vehicle, the vehicle undercarriage further comprising:
a suspension frame positioned in front of the floor panel;
a floor side member fixed to the suspension frame outside the vehicle width direction center of the suspension frame and extending rearward of the vehicle;
The floor side member
having at least two parts branched from the suspension frame and extending rearward of the vehicle;
The vehicle lower portion structure, wherein one of the at least two portions is branched outwardly or inwardly in the vehicle width direction from the suspension frame. At least two parts of the floor side member are
a first portion that branches outward in the vehicle width direction from the suspension frame and has an arc shape that protrudes outward in the vehicle width direction;
2. The vehicle lower structure according to claim 1, further comprising a second portion branching inwardly in the vehicle width direction from the suspension frame and forming an arcuate shape projecting inwardly in the vehicle width direction. an end surface of the second portion is connected to a side surface of the first portion of the floor side member,
The second portion of the floor side member is formed with an overhanging portion projecting from the bottom surface toward the first portion and overlapping and connected to the bottom surface of the first portion,
3. The vehicle lower structure according to claim 2, wherein the lower surface of the first portion and the lower surface of the second portion are inclined so as to become higher or lower as they approach the suspension frame. The suspension frame overlaps the projecting portion of the second portion of the floor side member, whereby the first portion, the second portion of the floor side member and the suspension frame are connected in an overlapping manner. 4. The vehicle undercarriage according to claim 3. The vehicle undercarriage further comprises:
a side sill extending in the longitudinal direction of the vehicle along the edge of the floor panel;
a front side member located in front of the vehicle with respect to the side sill;
a torque box connecting the front side member and the side sill,
The vehicle lower structure according to any one of claims 2 to 4, wherein the floor side member is connected to the torque box. The vehicle undercarriage further comprises:
a side sill extending in the vehicle front-rear direction along the edge of the floor panel and arranged outside the first portion of the floor side member in the vehicle width direction;
a lower cross member that extends in the vehicle width direction below the floor panel and is arranged rearward of the vehicle relative to the second portion of the floor side member;
a rear side member extending forward of the vehicle from a rear end of the vehicle and connected to the lower cross member;
The rear end portion of the first portion is connected to the side surface of the side sill on the inner side in the vehicle width direction,
The vehicle lower structure according to any one of claims 2 to 4, wherein the rear end portion of the second portion is connected to the lower cross member. The vehicle underbody structure further includes a center tunnel that protrudes upward and extends in the vehicle front-rear direction at the center of the floor panel in the vehicle width direction,
7. The vehicle according to any one of claims 2 to 6, wherein the second portion of the floor side member extends rearward of the vehicle so as to gradually approach and adjoin the center tunnel from the suspension frame. undercarriage. The vehicle underbody structure further comprises a bridging portion disposed inside the center tunnel and bridging two sidewalls of the center tunnel in the vehicle width direction,
8. The vehicle underbody structure according to claim 7, wherein the bridging portion is adjacent to a portion of the second portion of the floor side member that protrudes most inward in the vehicle width direction. The vehicle lower structure further includes an upper cross member extending in the vehicle width direction above the floor panel,
A portion of the first portion that protrudes most outwardly in the vehicle width direction and a portion of the second portion that protrudes most inwardly in the vehicle width direction are connected to the upper cross member through the floor panel. 9. The vehicle substructure according to any one of claims 2 to 8, wherein the floor panel and the floor panel overlap and are joined to the lower surface of the upper cross member.

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