Vehicle

Abstract

A vehicle according to the present disclosure comprises: a front sub-frame to which a front suspension is attached; a floor panel to which the front sub-frame is fastened and which forms a floor under the feet of the occupant; and a plurality of additional frames that extend in the vehicle front-rear direction and are disposed on the upper surface of the floor panel and fastened to the floor panel. The fastening points of the additional frames with the floor panel are provided with a plurality of locations including a first fastening point at a frontmost position. The first fastening point is provided close to a front fastening point between the front sub-frame and the floor panel.

Description

Vehicle

[0001] This technology relates to the technical field of vehicles equipped with a structure for efficiently propagating vibration energy.

[0002] Various proposals have been made regarding the structure of the vehicle body. For example, in Patent Document 1 below, a technique in which a side rail and a front frame portion are connected at an end in the vehicle width direction is disclosed.

[0003] Japanese Unexamined Patent Application Publication No. 2021-003940

[0004] By the way, in a vehicle, there is a problem that vibration energy generated during running is propagated to the floor panel and radiated into the passenger compartment. In the configuration disclosed in Patent Document 1, no device is provided to make it difficult for vibration energy to be propagated to the floor panel.

[0005] This technology has been made in view of the above circumstances, and an object thereof is to suppress the radiation of vibration energy into the passenger compartment and improve quietness.

[0006] The vehicle according to this technology includes a front subframe to which a front suspension is attached, a floor panel to which the front subframe is fastened and forms the floor under the feet of the occupants, and a plurality of additional frames that extend in the vehicle front-rear direction and are disposed on the upper surface of the floor panel and fastened to the floor panel. A plurality of fastening points between each of the additional frames and the floor panel are provided, including a first fastening point located at the most forward position, and the first fastening point is provided in proximity to a front fastening point that is a fastening point between the front subframe and the floor panel. The first fastening point being provided in proximity to the front fastening point means, for example, it may be provided in proximity across a firewall (also called a turbo board) provided near the front end of the floor panel. Alternatively, the first fastening point may be provided at a position closer to the front end of the side sill than the front fastening point. Further, the distance in the front-rear direction between the first fastening point and the front fastening point may be shorter than the pitch of each fastening point for fastening the additional frame and the floor panel.

[0007] This technology can suppress the radiation of vibration energy into the vehicle cabin, thereby improving quietness.

[0008] This is a block diagram showing the configuration of the vehicle. This is an exploded perspective view showing the section where the traction battery is housed and the parts to which the traction battery is attached. This is a plan view showing the parts assembled to the floor panel. This is a vertical cross-sectional view taken along the line A-A in Figure 3. This is a vertical cross-sectional view taken along the line B-B in Figure 3. This is a vertical cross-sectional view taken along the line C-C in Figure 3. This is a vertical cross-sectional view taken along the line D-D in Figure 3. This is a schematic diagram showing the state in which other parts are attached to the additional frame. This is a plan view showing the state in which the parts are assembled to the floor panel in the second embodiment. This is a vertical cross-sectional view taken along the line E-E in Figure 9. This is a plan view showing the state in which the parts are assembled to the floor panel in the first modified example. This is a plan view showing the state in which the parts are assembled to the floor panel in the second modified example.

[0009] <1. Vehicle Configuration> The configuration of Vehicle 1 in the first embodiment of this technology will be described with reference to Figure 1. Although a battery EV (Electric Vehicle) is given as an example of Vehicle 1, this technology is not limited to this and can be applied to various vehicles such as gasoline cars, hybrid cars, and hydrogen cars. Vehicle 1 comprises a driving battery 2, a PCU (Power Control Unit) 3, a motor 4, a connector unit 5, a control device 6, a display unit 7, and a communication unit 8.

[0010] Note that Figure 1 shows only a portion of the components of Vehicle 1, and Vehicle 1 may be equipped with a map locator, various sensors for driving, etc., as appropriate, although these are not shown.

[0011] The traction battery 2 is a high-voltage secondary battery that stores electrical energy used to power the vehicle 1. The traction battery 2 stores electrical energy used to drive the wheels, electrical energy used to operate the vehicle 1's air conditioning system, and electrical energy used to operate other equipment. Figure 1 shows the power supply from the traction battery 2 to drive the wheels and to the display unit 7, but the power supply used to operate other parts is not shown.

[0012] The PCU 3 supplies a DC voltage to the traction battery 2 for charging the traction battery 2. The PCU 3 is equipped with a DC / DC converter and the like for driving the motor 4. The PCU 3 generates an AC current to drive the motor 4 based on the power supply voltage supplied from the traction battery 2, and controls the torque of the motor 4 by controlling the AC current.

[0013] The PCU3 may also have a function to optimize energy efficiency by utilizing regenerative energy, such as by incorporating a regenerative braking function.

[0014] Motor 4 is configured as a motor generator with a power generation function, and drives the wheels based on the supplied alternating current.

[0015] The connector section 5 has a structure that allows a charging plug from a charging facility installed in each home or station to be plugged in. The connector section 5 outputs an AC voltage supplied via the plugged charging plug to the PCU 3. The PCU 3 charges the traction battery 2 by supplying a DC voltage converted by an AC / DC converter to the traction battery 2.

[0016] The control device 6 is configured with a processor such as a CPU (Central Processing Unit) and memory, and performs overall control of the vehicle 1. The control device 6 may be provided as a single unit, or it may be composed of multiple ECUs (Electronic Control Units). Multiple ECUs may include, for example, a battery control ECU that controls the charging of the traction battery 2, a display control ECU that controls the display of display devices (including meters, etc.) provided by the vehicle 1, an airbag control ECU, an air conditioning control ECU, a communication ECU that performs various types of communication, and so on.

[0017] The control device 6 performs various functions by executing various programs stored in memory, etc.

[0018] The display unit 7 comprehensively represents, for example, the Multi-Function Display (MFD) installed in front of the driver, and other display devices for presenting information to the driver. The display unit 7 displays information based on detection signals detected by various sensors installed in the vehicle 1. Various information such as the vehicle's total mileage, outside temperature, and instantaneous energy consumption is displayed on the display unit 7 as appropriate. In addition, the display unit 7 can display map information and extracted route information.

[0019] The communication unit 8 communicates with an external information processing device under the control of the control device 6. Through communication by the communication unit 8, the vehicle 1 can communicate with external server devices, vehicle-to-vehicle communication with other vehicles, and vehicle-to-infrastructure communication with roadside devices, etc.

[0020] <2. Vehicle Structure> The structure of the vehicle 1 in the first embodiment will be described with reference to Figure 2. In the following description, the direction of travel of the vehicle 1 is forward, and the front-rear direction is indicated. The width direction of the vehicle 1 is indicated as the left-right direction. The left-right direction is shown with the vehicle 1 facing forward.

[0021] Vehicle 1 comprises a floor panel 11 positioned at the occupants' feet and to which seats and the like are fixed; a front frame body 12 fastened to the front of the floor panel 11; a front subframe 13 positioned in front of the floor panel 11; and a pair of lower arms 14 attached to the left and right ends of the front subframe 13, respectively.

[0022] The floor panel 11 is formed by arranging a plate-shaped member facing vertically between a pair of side members that are spaced apart in the left-right direction and extend in the front-rear direction. The floor panel 11 has a main surface portion 16 to which a firewall 15 (also called a toe board), seats (not shown), etc. are attached, and cross members 17 formed on the upper and lower surfaces of the main surface portion 16 and extending in the left-right direction.

[0023] The main surface portion 16 of the floor panel 11 functions as the floor surface of the passenger compartment and the cargo compartment.

[0024] Furthermore, the main surface portion 16 of the floor panel 11 may be formed separately for the passenger compartment floor portion and the cargo compartment floor portion.

[0025] A portion of the pair of side members in the floor panel 11 is provided as a side sill 11a.

[0026] The firewall 15 includes a lower panel 15a, an upper panel 15b, and a firewall cross member 15c.

[0027] The lower panel 15a of the firewall 15 is mounted on the upper part of the front end of the main surface portion 16 of the floor panel 11, facing approximately in the front-to-back direction. The upper end of the lower panel 15a is located in front of the lower end.

[0028] The upper panel 15b is a plate-shaped member that extends upward from the upper end of the lower panel 15a. The lower panel 15a and the upper panel 15b may be formed integrally as a single plate-shaped member, or they may be separate plate-shaped members connected to each other.

[0029] The firewall cross member 15c is attached to the front of the lower panel 15a. The firewall cross member 15c is formed in a shape in which both ends of the left and right extending members are bent downward. Both ends of the firewall cross member 15c are connected to the front end of the side sill 11a.

[0030] The firewall cross member 15c may, for example, have a hollow cross-section formed by press molding, or it may have a solid cross-section formed by aluminum die casting.

[0031] The cross member 17 may be formed integrally with the main surface portion 16, or it may be formed separately from the main surface portion 16.

[0032] The cross member 17 may, for example, have a hollow cross-section formed by press molding, or it may have a solid cross-section formed by aluminum die casting.

[0033] In Figure 2 and subsequent figures, only the cross members 17 provided on the upper part of the main surface 16 of the floor panel 11, near the boundary between the portion forming the floor under the occupants' feet and the portion forming the floor of the cargo area, are shown among the multiple cross members 17 provided on the floor panel 11.

[0034] The front frame body 12 includes, for example, a pair of first frames 12a extending in the front-rear direction and positioned spaced apart to the left and right, and one or more second frames 12b extending in the left-right direction and connecting the first frames 12a.

[0035] The pair of first frames 12a are connected to the firewall cross member 15c of the firewall 15. Alternatively, the pair of first frames 12a may be fastened to a rear frame (not shown) located at the rear of the vehicle to form a pair of main frames extending in the front-rear direction.

[0036] The front subframe 13 is formed from a highly rigid material such as casting or sheet metal, and is located below the front frame body 12. The front subframe 13 has a pair of first members 13a that extend in the front-rear direction and are spaced apart in the left-right direction, one or more second members 13b that extend in the left-right direction and connect the pair of first members 13a, and a bumper beam 13c that is located furthest forward and extends in the left-right direction.

[0037] In addition, in vehicle 1, the bumper beam 13c may be formed separately from the front subframe 13, and the bumper beam 13c may be attached to the front subframe 13.

[0038] The lower arm 14 is formed in a Y-shape when viewed from above, for example. The outer end of the lower arm 14 in the vehicle width direction is rotatable approximately vertically, and the central end in the vehicle width direction is attached to the front subframe 13. The axis of rotation of the lower arm 14 is an axis that extends in the front-rear direction.

[0039] Each lower arm 14 is attached to the front suspension via bushings or the like (not shown). Vertical vibrations caused by uneven road surfaces are mainly absorbed by the front suspension, making them less likely to be transmitted to the vehicle frame. However, vibration energy that cannot be absorbed by the front suspension is transmitted to the front subframe 13 via the lower arm 14.

[0040] A motor 4 is attached to the first member 13a and the second member 13b of the front subframe 13 via bushings or the like (not shown). The motor 4 attached to the front subframe 13 may be one of two motors that are mounted separately in the front-rear direction of the vehicle 1.

[0041] The vibration energy generated in the motor 4 is transmitted to the front subframe 13 via bushings and the like.

[0042] The front frame body 12 and the front subframe 13 are made of materials and have a structure that makes them more rigid than the floor panel 11.

[0043] The vehicle 1 further includes a battery case 18 disposed below the floor panel 11 and having a traveling battery 2 disposed therein.

[0044] The configuration of the battery case 18 can be considered in various ways. For example, the battery case 18 may be configured to include a frame-shaped battery frame that penetrates vertically, a lower case attached to the lower part of the battery frame, and a cover panel attached to the upper part of the battery frame. Alternatively, the battery case 18 may be configured by combining a lower case that is open upward and an upper case that is open downward.

[0045] The battery case 18 is attached to the floor panel 11 from below. Specifically, this will be described with reference to FIGS. 3 and 4. Note that FIG. 3 is a view of the assembled state of each part as seen from above. FIG. 4 is a cross-sectional view taken along the A - A arrow in FIG. 3. Also, in FIG. 3, the front frame body 12 is not shown for ease of understanding.

[0046] The floor panel 11 is formed with downward convex portions 11b protruding downward from both ends in the left - right direction, thereby forming an arrangement recess 11c that is open downward. The battery case 18 is arranged in the arrangement recess 11c.

[0047] At the lower end of the battery case 18, as shown in FIG. 2 and the like, a plurality of attachment protrusions 18a formed in a plate shape that extends laterally in each of the left - right directions and faces the vertical direction are formed at intervals in the front - rear direction.

[0048] The attachment protrusion 18a is formed with an insertion hole 18b that penetrates in the vertical direction and through which a bolt is inserted. Further, the downward convex portion 11b is formed with a screw hole 11d that opens downward at a position substantially the same as the insertion hole 18b in the front - rear and left - right directions.

[0049] The battery case 18 is attached to the floor panel 11 from below by screwing the tip of a bolt inserted through the insertion hole 18b of the attachment protrusion 18a provided in the lower case into the screw hole 11d formed in the arrangement recess 11c of the floor panel 11.

[0050] In this example, the battery case 18 is shown positioned at the occupant's feet, but this is not the only option; the battery case 18 may also be positioned under the floor of the cargo area.

[0051] Vehicle 1 also includes two additional frames 19, 19 that are mounted on top of the floor panel 11.

[0052] The additional frame 19 is, for example, made of the same material as the vehicle body, extends in the front-to-rear direction, and has a hat-shaped cross-section.

[0053] If the additional frame 19 is made of sheet metal, it is joined to the floor panel 11 by spot welding. If the additional frame 19 is made of solid die-cast aluminum, it is joined to the floor panel 11 by rivets, screws, or the like.

[0054] The additional frame 19 has a hat-shaped cross-section, comprising a top plate portion 20, a pair of side plate portions 21, 21 that are continuous downward from the left and right ends of the top plate portion 20, and a pair of flanges 22, 22 that are continuous outward in the left and right directions from the lower ends of the side plate portions 21.

[0055] The mounting positions of the front subframe 13 and the additional frame 19 relative to the floor panel 11 will be described below.

[0056] Figure 5 is a view along the line B-B in Figure 3. Figure 6 is a view along the line C-C in Figure 3. Figure 7 is a view along the line D-D in Figure 3.

[0057] As shown in Figures 3 and 5, the front subframe 13 is attached to the floor panel 11 from below by bolting or the like, behind the mounting position of the firewall 15 on the floor panel 11. The mounting position of the front subframe 13 to the floor panel 11 is called the front fastening point Pf. When the floor panel 11 and the subframe 13 are fastened together by four bolts, the front fastening point Pf may refer to each of the four fastening points, or it may refer to two or four fastening points and their surroundings collectively. In this embodiment, the front fastening point Pf is defined as the two fastening points provided for each of the two first members 13a of the front subframe 13 that are spaced apart in the left-right direction.

[0058] The additional frame 19 is attached to the floor panel 11 by bolting or the like, with its flange 22 located behind the firewall 15 on the floor panel 11.

[0059] Multiple fastening points are provided between the flange 22 of the additional frame 19 and the floor panel 11, spaced apart in the front-rear direction.

[0060] Of the fastening points between the flange 22 and the floor panel 11, the fastening point located furthest forward is designated as the first fastening point P1, the fastening point located furthest rear is designated as the second fastening point P2, and the remaining fastening points are designated as the third fastening points P3. In this embodiment, the first fastening point P1, second fastening point P2, and third fastening point P3 are also referred to collectively as pairs of fastening points located spaced apart in the left-right direction for each additional frame 19.

[0061] The first fastening point P1 is located behind the portion of the floor panel 11 to which the firewall 15 is connected, and close to the firewall 15. In other words, the distance between the first fastening point P1 and the front fastening point Pf is small.

[0062] Because the distance between the first fastening point P1 and the front fastening point Pf is short, and the rigidity of the front subframe 13 and the additional frame 19 are approximately the same, in other words, because the rigidity of the additional frame 19 is closer to that of the front subframe 13 than that of the floor panel 11, much of the vibration energy transmitted to the front subframe 13 is transmitted to the additional frame 19 via the floor panel 11.

[0063] In other words, vibration energy transmitted to the occupants' feet in the central part of the floor panel 11 is reduced, and the radiation of noise into the vehicle interior due to vibrations of the floor panel 11 can be suppressed.

[0064] Furthermore, the statement that the distance between the first fastening point P1 and the front fastening point Pf is short may mean, for example, that the distance between the front fastening point Pf and the first fastening point P1 is shorter than the distance between the front fastening point Pf and the front end of the side sill 11a.

[0065] Furthermore, the statement that the distance between the first fastening point P1 and the front fastening point Pf is short may also mean that the distance between the first fastening point P1 and the front fastening point Pf in the front-to-back direction is short.

[0066] The statement that the distance between the first fastening point P1 and the front fastening point Pf is short in the front-to-back direction can also be rephrased as the distance between the first fastening point P1 and the front fastening point Pf being shorter than the distance between the first fastening point P1 and the third fastening point P3, as shown in Figure 7.

[0067] Alternatively, the statement that the front-to-back distance between the first fastening point P1 and the front fastening point Pf is short may mean that the distance between the first fastening point P1 and the front fastening point Pf is shorter than the pitch of the fastening points in the additional frame 19, such as the distance between the first fastening point P1 and the third fastening point P3, the distance between the third fastening points P3, and the distance between the third fastening point P3 and the second fastening point P2, as shown in Figure 7.

[0068] As shown in Figure 6, the additional frame 19 is bolted to the cross member 17 of the floor panel 11.

[0069] The cross member 17 of the floor panel 11 is formed such that the portion connected to the additional frame 19 is a recessed portion that protrudes downward. The vertical position of the bottom surface of the recess in the cross member 17 coincides with the surface of the main surface portion 16.

[0070] In other words, by making the main surface portion 16 and the bottom surface of the recess of the cross member 17 the same height, it is possible to attach the additional frame 19, which has a flat lower surface of the flange 22, without any gaps.

[0071] The additional frame 19 is located in the floor panel 11 where the conventional center tunnel was formed, that is, in the center in the left-right direction and between the occupants. The approximate center in the left-right direction is also where various components such as the center console box are located.

[0072] In this example, the two additional frames 19, 19 function as a base to which these other components 23 are attached. Specifically, as shown in Figure 8, a portion of the top plate portion 20 of the additional frame 19 serves as the mounting portion 24 for the other components 23 (hatched portion in Figure 8).

[0073] Other components 23 attached to the mounting portion 24 of the highly rigid additional frame 19 maintain a stable posture. In particular, since the vehicle 1 of this embodiment is equipped with two additional frames 19, the posture of the other components 23 can be further stabilized by arranging them to straddle the two additional frames 19.

[0074] Furthermore, there is no need to provide any additional parts other than the additional frame 19 for attaching other parts 23, thus reducing the number of parts.

[0075] Furthermore, the mounting portion 24 of the additional frame 19 may be provided with a mechanism for attaching other components 23.

[0076] <3. Second Embodiment> The vehicle 1A of the second embodiment is equipped with an additional set of frames in addition to the additional frames 19, 19, which are attached to the floor panel 11.

[0077] In this example, another set of frames, separate from the aforementioned additional frames 19, 19, will be referred to as the second additional frames 25, 25.

[0078] Components similar to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0079] Figure 9 is a top view of the vehicle 1A with all parts assembled to the floor panel 11. Figure 10 is a view taken along the line E-E in Figure 9.

[0080] The additional frame 19 is a frame that extends in the front-to-back direction at approximately the center in the left-to-right direction on the upper part of the floor panel 11, similar to the first embodiment.

[0081] The second additional frame 25 is a frame attached to the lower part of the floor panel 11, and is positioned to extend between the front fastening point Pf and the first fastening point P1.

[0082] In this example, the front fastening point Pf and the first fastening point P1 are offset in the left-right direction. Therefore, the second additional frame 25 is attached to the floor panel 11 such that its extension direction is oblique to the front-rear and left-right directions.

[0083] In vehicle 1A, the front end of the second additional frame 25 is bolted together with the front subframe 13 and floor panel 11 at the front fastening point Pf.

[0084] Furthermore, in vehicle 1A, the rear end of the second additional frame 25 is bolted together with the floor panel 11 and the flange 22 of the additional frame 19 at the first fastening point P1.

[0085] If the second additional frame 25 is made of sheet metal, it may be attached to the floor panel 11 by spot welding.

[0086] In the configuration of vehicle 1A, vibration energy transmitted to the front subframe 13 is transmitted to the cross member 17 via the second additional frame 25 and the additional frame 19. In particular, by providing the second additional frame 25 from the front fastening point Pf to the first fastening point P1, vibration energy can be efficiently transmitted to the cross member 17.

[0087] Therefore, the radiation of noise into the vehicle interior due to vibration of the floor panel 11 can be suppressed more effectively.

[0088] In this example, the second additional frame 25 is shown to be attached to the lower part of the floor panel 11, but the second additional frame 25 may also be attached to the upper part of the floor panel 11. In that case, the second additional frame 25 may be positioned to penetrate the firewall 15 attached to the upper part of the floor panel 11 in a substantially front-to-back direction.

[0089] <4. Modifications> The first modification will be explained with reference to Figure 11. The vehicle 1B relating to the first modification is equipped with an additional frame 19B. The additional frame 19B has a different shape from the additional frame 19.

[0090] Specifically, as shown in Figure 11, the overall shape of the additional frame 19B when viewed from above is not a straight line, but rather the front portion is displaced outward in the vehicle width direction as it extends forward. In other words, the two additional frames 19B are formed to be further apart from each other as they extend forward.

[0091] This allows the distance between the front fastening point Pf and the first fastening point P1 to be shortened, and a large portion of the vibration energy transmitted to the front subframe 13 can be transmitted to the additional frame 19B.

[0092] The second modification will be explained with reference to Figure 12. The vehicle 1C according to the second modification is equipped with an additional frame 19C. The additional frame 19C has the same shape as the additional frame 19, but its length in the front-rear direction is different.

[0093] In this modified example, the firewall 15 is configured such that the connection point between the lower panel 15a and the floor panel 11 is located behind the front end of the floor panel 11.

[0094] Specifically, the additional frame 19C is configured such that its rear end is fastened to the cross member 17 and its front end penetrates the firewall 15 and is positioned in front of the firewall 15.

[0095] This makes it possible to position the first fastening point P1 in front of the firewall 15, thereby shortening the distance between the front fastening point Pf and the first fastening point P1.

[0096] Furthermore, by combining the first and second modified examples, it is possible to further reduce the distance between the front fastening point Pf and the first fastening point P1. In this combination, it is also possible to set the length of the additional frame 19C in the front-rear direction so that its front end reaches the front fastening point Pf.

[0097] This makes it possible to fasten the rear end of the front subframe 13, the front end of the floor panel 11, and the front end of the additional frame 19C at the front fastening point Pf.

[0098] Other variations will be described. The additional frames 19 (19B, 19C) mentioned above were shown as being attached to the upper part of the floor panel 11. However, the additional frames 19 (19B, 19C) may also be attached to the lower part of the floor panel 11.

[0099] Furthermore, in this case, the battery case 18, which houses the traction battery 2, is mounted under the floor of the cargo area rather than under the occupants' feet on the floor panel 11. This prevents interference between the additional frame 19 (19B, 19C) and the battery case 18, allowing for a suitable arrangement.

[0100] Furthermore, in this case, the firewall 15 attached to the top of the floor panel 11 does not interfere with the additional frames 19 (19B, 19C), making it easier to extend the front end of the additional frames 19 (19B, 19C) further forward, and thus easier to propagate vibration energy to the cross member 17.

[0101] The aforementioned vehicle 1 (1A, 1B, 1C) is equipped with two additional frames 19 (19B, 19C). However, the vehicle 1 (1A, 1B, 1C) may also be equipped with one additional frame 19 (19B, 19C) located approximately in the center in the left-right direction, or with three or more additional frames 19 (19B, 19C).

[0102] <5. Summary> The vehicle 1 (1A, 1B, 1C) of this technology comprises a front subframe 13 to which the front suspension is attached, a floor panel 11 to which the front subframe 13 is fastened and which forms the floor under the occupants' feet, and a plurality of additional frames 19 (19B, 19C) that extend in the longitudinal direction of the vehicle, are positioned on the upper surface of the floor panel 11 and are fastened to the floor panel 11. Furthermore, each additional frame 19 (19B, 19C) has multiple fastening points with the floor panel 11, including a first fastening point P1 located at the very front, and the first fastening point P1 is located close to the front fastening point Pf, which is the fastening point between the front subframe 13 and the floor panel 11. The first fastening point P1 being located close to the front fastening point Pf means, for example, that it may be located close across a firewall 15 located near the front end of the floor panel 11. Alternatively, the first fastening point P1 may be located closer to the front fastening point Pf than the front end of the side sill 11a. Furthermore, the longitudinal distance between the first fastening point P1 and the front fastening point Pf may be shorter than the pitch of each fastening point (first fastening point P1, second fastening point P2, third fastening point P3) that fastens the additional frame 19 (19B, 19C) to the floor panel 11. In this configuration, the front subframe 13 and the floor panel 11 are fastened at the front fastening point Pf, and the floor panel 11 and the additional frame 19 (19B, 19C) are fastened at least at the first fastening point P1. The distance between the front fastening point Pf and the first fastening point P1 is set to be relatively close. As a result, vibration energy transmitted from the front suspension is mainly transmitted from the front subframe 13 through the floor panel 11 to the additional frame 19 (19B, 19C). The vibration energy transmitted to the additional frame 19 (19B, 19C) is transmitted to the rear of the vehicle body and attenuated without causing the floor panel 11 to vibrate. Therefore, the portion of vibration energy transmitted to the floor panel 11 is reduced, suppressing the radiation of noise into the cabin and improving passenger comfort. In particular, it is possible to efficiently suppress the radiation of mid-frequency sounds into the cabin, which was previously difficult to address.Furthermore, by bringing the rigidity of the front subframe 13 closer to that of the additional frames 19 (19B, 19C), and in particular by making the difference in rigidity between the front subframe 13 and the additional frames 19 (19B, 19C) smaller than the difference in rigidity between the front subframe 13 and the floor panel 11, vibration energy transmitted from the front subframe 13 is efficiently transmitted to the additional frames 19 (19B, 19C), thereby achieving a high level of noise suppression effect on the radiation of noise into the passenger compartment.

[0103] Vehicle 1 (1A, 1B, 1C) of this technology may be a battery electric vehicle (EV). When vehicle 1 (1A, 1B, 1C) is a battery electric vehicle (EV), there are no components that extend in the longitudinal direction at the top or bottom of the floor panel 11 and have a large cross-sectional area, such as a propeller shaft or exhaust pipe, and there is no need to provide a center tunnel in the floor panel 11. Therefore, the floor panel 11 in a battery electric vehicle is often formed in a flat shape with few undulations. Such a floor panel 11 has low rigidity in the central part, making it prone to vibration, and the radiation of noise into the passenger compartment becomes a problem. With this configuration, in a battery electric vehicle, the vibration of the floor panel 11 can be suppressed more effectively by fastening the additional frame 19 (19B, 19C) that extends in the vertical direction to the floor panel 11, and a high level of noise radiation suppression effect can be obtained.

[0104] In vehicle 1 (1A, 1B, 1C), the additional frames 19 (19B, 19C) may have mounting portions 24 for other components 23 that are positioned on the upper part of the floor panel 11. Other components include, for example, parts such as a heating system or ducts. By attaching the other components 23 to the additional frames 19 (19B, 19C), which have high rigidity and strength, it becomes unnecessary to increase the strength of the floor panel 11 in order to attach the other components 23 to the floor panel 11. Furthermore, by having the additional frames 19 (19B, 19C) function as a mounting base, it becomes unnecessary to install new base members, resulting in space savings, a reduction in the number of parts, and a reduction in assembly man-hours. Moreover, by utilizing the additional frames 19 (19B, 19C) as a mounting base for multiple other components, a further reduction in the number of parts can be achieved.

[0105] In vehicle 1 (1A, 1B, 1C), the floor panel 11 has a cross member 17 extending in the vehicle width direction, and the additional frames 19 (19B, 19C) may have their rear ends fastened to the cross member 17. The cross member 17 is, for example, made of a highly rigid member. By connecting the additional frames 19 (19B, 19C) to the highly rigid cross member 17 by bolting or the like, much of the vibration energy transmitted from the front subframe 13 to the additional frames 19 (19B, 19C) is transmitted further to the rear of the vehicle body via the cross member 17. Therefore, the vibration energy transmitted to the floor panel 11 can be reduced, and the radiation of noise into the passenger compartment caused by vibrations of the floor panel 11 can be suppressed.

[0106] Vehicle 1A may be provided with a second additional frame 25 that extends between the front fastening point Pf and the first fastening point P1. This allows more vibration energy to be transmitted from the front subframe 13 to the additional frame 19 via the second additional frame 25. Consequently, the vibration energy transmitted to the floor panel 11 can be further reduced, and the radiation of noise into the passenger compartment caused by vibrations of the floor panel 11 can be suppressed more effectively.

[0107] Furthermore, the various examples mentioned above can be combined as appropriate.

[0108] 1, 1A, 1B, 1C Vehicle 11 Floor panel 13 Front subframe 17 Cross member 19, 19B, 19C Additional frame 23 Other parts 24 Mounting part 25 Second additional frame P1 First fastening point Pf Front fastening point

Claims

1. A vehicle comprising: a front subframe to which a front suspension is attached; a floor panel to which the front subframe is fastened and which forms the floor beneath the occupants' feet; and a plurality of additional frames extending in the longitudinal direction of the vehicle, positioned on the upper surface of the floor panel and fastened to the floor panel, wherein each of the additional frames has multiple fastening points with the floor panel, including a first fastening point located furthest forward, and the first fastening point is located close to the front fastening point which is the fastening point between the front subframe and the floor panel.

2. The vehicle according to claim 1, which is a battery electric vehicle.

3. The vehicle according to claim 1, wherein the additional frame has mounting portions for other components located on the upper part of the floor panel.

4. The vehicle according to claim 1, wherein the floor panel has a cross member extending in the vehicle width direction, and the additional frame has its rear end fastened to the cross member.

5. The vehicle according to claim 1, further comprising a second additional frame extending between the front fastening point and the first fastening point.

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