Vehicle

Abstract

This invention relates to a vehicle that adjusts the fore-aft rigidity balance of the vehicle in such a way that the node of torsional deformation generated when the vehicle is steered is located within the fore-aft direction of the driver's seat. The vehicle also has a battery disposed under the floor of the vehicle, with a plurality of side fastening points provided at both ends of the battery in the vehicle width direction for securing the battery to the frame of the vehicle. The density of the side fastening points located rearward of the fore-aft center of the battery is higher than the density of the side fastening points located forward of the fore-aft center of the battery.

Description

Technical Field

[0001] This specification discloses a vehicle capable of suppressing displacement vibrations in the driver's seat. Background Technology

[0002] As is well known, vehicles vibrate or twist as they move. Many technologies for suppressing such vibrations or twists have been proposed in the past. For example, Japanese Patent Application Publication 2002-356180 discloses a technology in which the rigidity of a body mounting bracket arranged at multiple locations on the frame is set such that the nodal position of the bending vibration mode of the frame coincides with the load input point from the wheel to the frame. By adopting this structure, the contribution of the inherent vibration modes in the vibration can be reduced, thereby suppressing the amplification of vibrations in the vehicle's frame components. Summary of the Invention

[0003] However, in the case of Japanese Patent Application Publication No. 2002-356180, the torsional deformation of the vehicle associated with steering was not adequately studied. When the vehicle undergoes torsional deformation, displacement vibration occurs in the driver's seat, causing discomfort to the driver.

[0004] Therefore, this specification discloses a vehicle that can further improve driver comfort.

[0005] In the vehicle disclosed in this specification, the rigidity balance of the vehicle is adjusted in such a way that the node of torsional deformation generated when the vehicle is steered is located within the range of the driver's seat in the forward and backward direction of the vehicle.

[0006] By designing the structure in this way, the displacement vibration felt by the driver can be reduced when the vehicle undergoes torsional deformation, thereby further improving driver comfort.

[0007] In this case, the weight balance of the vehicle can also be adjusted in such a way that the position of the vehicle's center of gravity in the forward and backward direction is within the range of the driver's seat in the forward and backward direction of the vehicle.

[0008] By adopting this structure, displacement vibration can be further reduced, thus further improving driver comfort.

[0009] Alternatively, the vehicle may also have a battery disposed under the floor of the vehicle, with multiple side fastening points provided at both ends of the battery in the vehicle width direction for fastening the battery to the frame of the vehicle, wherein the density of the side fastening points located rearward from the center of the battery in the longitudinal direction is higher than the density of the side fastening points located forward from the center of the battery in the longitudinal direction.

[0010] By increasing the number of fastening points on the rear side, the rigidity of the vehicle on the rear side is increased, making it easier to bring the node closer to the driver's seat.

[0011] Alternatively, the front and rear ends of the battery may be provided with a plurality of front fastening points and a plurality of rear fastening points for fastening the battery to the frame of the vehicle, and the density of the front fastening points and the rear fastening points is higher than the density of the side fastening points located in front of the center of the battery in the front-rear direction.

[0012] Forces from the suspension components are input to the front and rear fastening points. By increasing the number of these front and rear fastening points, the forces input from the suspension components are distributed.

[0013] Alternatively, it may also include: a front body, including a pair of wheel arches, integrally formed by casting; a rear body, including a pair of wheel arches, integrally formed by casting; a battery disposed under the floor of the vehicle; and an electric motor disposed on the side rearward of the driver's seat.

[0014] By setting it to this configuration, it is easy to achieve rigidity and weight balance of the vehicle, and it is easy to bring the nodes and center of gravity closer to the driver's seat.

[0015] According to the technology disclosed in this specification, driver comfort is further improved by suppressing seat displacement vibration caused by torsional deformation. Attached Figure Description

[0016] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which like reference numerals denote like elements, and wherein:

[0017] Figure 1 It is a schematic side view of the vehicle;

[0018] Figure 2 It is a schematic top view of the vehicle's frame, body, and battery;

[0019] Figure 3 This is a diagram showing the change in steering angle θ when a vehicle changes lanes to the left.

[0020] Figure 4 It is a graph representing the deformation of the vehicle frame at time t1.

[0021] Figure 5 It is a schematic diagram showing the vehicle's center of gravity, nodes, and the positional relationship of the seats; and

[0022] Figure 6 This is a three-dimensional drawing showing an example of the front of the vehicle body. Detailed Implementation

[0023] The structure of vehicle 10 will now be described with reference to the accompanying drawings. Figure 1 This is a schematic side view of vehicle 10. Furthermore, Figure 2 This is a schematic top view of the frame, body, and battery 20 of vehicle 10. Vehicle 10 is a two-seater vehicle with two seats 22 arranged side-by-side. Figure 1 (Only one was observed in the vehicle). One of the two seats 22 is the driver's seat, and the other is the front passenger seat. Furthermore, the vehicle 10 is a battery electric vehicle that uses electricity stored in the battery 20 to drive the electric motor 30, thereby enabling the vehicle 10 to move.

[0024] Vehicle 10 has front beams 14R and 14L, lower side beams 16R and 16L, and rear beams 18R and 18L. The front beams 14R and 14L are frames extending in the longitudinal direction at the front of vehicle 10. The two front beams 14R and 14L are spaced apart and symmetrically arranged in the vehicle width direction. A front body 15, including wheel arches, is mounted on the two front beams 14R and 14L.

[0025] The lower side beams 16R and 16L are frames extending in the longitudinal direction from the center of the vehicle 10. Like the front beams 14R and 14L, the lower side beams 16R and 16L are symmetrically arranged, spaced apart in the vehicle width direction. The rear beams 18R and 18L are frames extending in the longitudinal direction from the rear of the vehicle 10. Like the front beams 14R and 14L, the rear beams 18R and 18L are also symmetrically arranged, spaced apart in the vehicle width direction. Furthermore, a rear body 19, including wheel covers, is mounted on each of the two rear beams 18R and 18L. Additionally, the vehicle 10 has multiple crossbeams (not shown) spanned between these two left-right arranged frames.

[0026] In this example, the transmission drive axle 32, including the electric motor 30, is located at the rear of the vehicle 10 and behind the seat 22. Additionally, the power control unit 34, which manages the charging and discharging of the battery 20 (see reference...) Figure 2 It is also located behind seat 22. This configuration of the transmission drive axle 32 and power control unit 34 is determined with consideration of the vehicle's weight balance, which will be described later.

[0027] Battery 20 stores the electricity supplied to motor 30. In this example, battery 20 is a rechargeable and dischargeable secondary battery. For example, battery 20 is a lithium-ion battery. To ensure sufficient driving range, vehicle 10 has a large and flat battery 20. For example, the planar dimensions of battery 20 are approximately the same as the floor of the passenger compartment. Battery 20 is disposed under the floor of the passenger compartment and mounted on the vehicle frame. More specifically, battery 20 is secured to lower side beams 16R, 16L and crossbeams. Figure 2In the diagram, the cross symbol indicates the fastening point 40 where battery 20 is secured to the vehicle frame. For example... Figure 2 As shown, the battery 20 is fastened to the vehicle frame at its periphery. The density of each fastening point 40 is determined by taking into account the rigidity of the vehicle.

[0028] The following is for reference Figures 3 to 5 The density distribution of the fastening point 40 and the determination of the vehicle's weight balance are explained. The vehicle is sometimes steered while maintaining a high speed (e.g., 100 km / h). For example, in situations where the vehicle is being steered to the left lane, such as... Figure 3 As shown, the steering angle θ changes significantly to the left, then gradually to the right, eventually returning to a steering angle θ = 0. This steering action causes torsional deformation in the vehicle body. Figure 4 It is a curve representing the deformation of the frame of vehicle 10 at time t1 when the change is greatest in the left direction.

[0029] exist Figure 4 In the diagram, the horizontal axis of each graph represents the vehicle's position in the front-to-back direction, with the right side of the paper representing the rear of the vehicle. Additionally, the vertical axis of each graph represents the amount of frame deformation. Figure 4 In the diagram, the upper layer represents the deformation of the vehicle equipped with battery 20, and the lower layer represents the deformation of the vehicle without battery 20. Additionally, in each curve diagram, curve D_14R represents the deformation of the right front beam 14R, and curve D_14L represents the deformation of the left front beam 14L. The other curves are also labeled with the corresponding frame marking after "D_".

[0030] like Figure 4 As shown, the right-side frames 14R, 16R, and 18R of the vehicle and the left-side frames 14L, 16L, and 18L of the vehicle deform symmetrically. For example, in Figure 4 In the example, the lines connecting curves D_14R, D_16R, and D_18R slope upwards and backwards as they approach the rear of the vehicle, moving towards the positive side. Conversely, the lines connecting curves D_14L, D_16L, and D_18L slope downwards and backwards as they approach the rear of the vehicle, moving towards the negative side. This indicates that when the vehicle makes a large turn to the left or right, the vehicle body undergoes torsional deformation.

[0031] The torsional deformation is smaller in vehicles equipped with battery 20 compared to those without. This is believed to be because the vehicle's rigidity is increased by securing battery 20 to the lower side beams 16R, 16L and the crossbeam. However, even with increased vehicle rigidity, it is difficult to achieve zero torsional deformation. Furthermore, torsional deformation causes displacement vibrations that can compromise driver comfort.

[0032] Additionally, refer to Figure 4 There exists a point where curves D_16R and D_16L intersect. This intersection point is the torsional deformation node An. This node An moves back and forth depending on the vehicle's rigidity balance. For example, without battery 20, node An is located near the vehicle's front-to-back center, determined by the rigidity balance of the frame and the vehicle body itself. On the other hand, with battery 20 installed, node An is further away from the vehicle's center than when battery 20 is not present. This is because the vehicle's front-to-back rigidity balance changes depending on the presence or absence of battery 20. In other words, by changing the vehicle's rigidity balance, the position of the torsional deformation node An can be changed.

[0033] Here, even if the vehicle undergoes significant torsional deformation, the deformation at node An is approximately zero. Therefore, when the driver's seat is positioned at node An, even in the event of torsional deformation due to steering, the displacement vibration experienced by the driver can be minimized. In particular, by aligning the driver's head and node An in the forward and backward directions, head movement of the driver can be effectively prevented, thus improving driver comfort.

[0034] Therefore, in this example, the vehicle's rigidity balance is adjusted so that node An is located within the fore-and-aft direction of seat 22. Specifically, with seat 22 as the boundary, the vehicle rigidity on the front side is made approximately the same as that on the rear side. To achieve this rigidity balance, in this example, the density of the fastening points 40 of battery 20 is varied depending on the location.

[0035] Specifically, to secure the battery 20 to the lower side beams 16R and 16L, multiple side fastening points 40a are provided at both ends of the battery 20 in the vehicle width direction. In this example, the density of the side fastening points 40a located rearward of the centerline C of the battery 20 in the longitudinal direction is higher than the density of the side fastening points 40a located forward of the centerline C. In other words, the average spacing of the side fastening points 40a located rearward of the centerline C is less than the average spacing of the side fastening points 40a located forward of the centerline C. By adopting this structure, the battery 20 is firmly connected to the lower side beams 16R and 16L at the rearward location of the centerline C, improving the rigidity of the vehicle. Furthermore, this results in a higher density of the node An compared to the centerline C. Figure 4 The lower layer of the structure moves further rearwards. Utilizing this principle, in this example, the density of the front side fastening points 40a is actively made different from the density of the rear side fastening points 40a, so that the fore-and-aft position of the torsional deformation node An converges within the fore-and-aft range of the seat 22. Furthermore, because node An is located within the fore-and-aft range of the seat 22, the displacement vibration felt by the driver during vehicle cornering is reduced, thus maintaining greater driver comfort.

[0036] In addition, to secure the battery 20 to the crossbeam, multiple front fastening points 40b and rear fastening points 40c are provided at the front and rear ends of the battery 20, respectively. Loads are input from the suspension components (not shown) to the periphery of these front fastening points 40b and rear fastening points 40c. In this example, the density of these front fastening points 40b and rear fastening points 40c is higher than the density of the side fastening points 40a located forward of the centerline C in the front-rear direction. This structure effectively transmits and disperses the load input from the suspension components to the battery 20.

[0037] In addition, such as Figure 6 As shown, the front body 15 can also be constructed from a die-cast component made entirely of aluminum. In this case, the front body 15 can also be integrally formed with a pair of wheel arches. Furthermore, a portion of the front body 15 can function as front beams 14R and 14L. Similarly, the rear body 19 can also be integrally formed with a pair of wheel arches, and a portion of it can function as rear beams 18R and 18L. Thus, by constructing the front body 15 and rear body 19 from die-cast components, the rigidity of both can be maintained at a higher level, and the balance of their rigidity can be easily controlled.

[0038] Furthermore, in this example, the configuration of the vehicle components is adjusted so that the vehicle's center of gravity Pg is positioned within the fore-aft direction of the seat 22. That is, in conventional engine-powered vehicles, heavy objects (such as the engine) are concentrated at the front of the vehicle, and the center of gravity Pg is often located further forward than the seat 22. As a result, previously, such as Figure 5 As shown in the upper part, the vehicle's center of gravity Pg deviates significantly from the seat 22 and node An, resulting in a greater displacement vibration felt by the driver.

[0039] On the other hand, as in this example, in the case of a battery electric vehicle, a large and heavy battery 20 is installed in the vehicle. By placing this battery 20 in the floor compartment of the passenger compartment, the center of gravity Pg is significantly shifted towards the center of the vehicle compared to the case of an engine-powered vehicle. Furthermore, in this example, other heavy objects, such as the transmission drive axle 32 including the electric motor 30 and the power control unit 34, are positioned behind the seat 22. In this example, the positions of these heavy objects are adjusted so that the fore-and-aft position of the center of gravity Pg is approximately aligned with the fore-and-aft position of the seat 22, and thus with the fore-and-aft position of node An.

[0040] Therefore, as Figure 5 As shown in the lower layer, the seat 22 (and thus the driver), node An, and center of gravity Pg are all in the same front-to-back position, which can further reduce the displacement vibration felt by the driver.

[0041] Furthermore, the structures described so far are merely examples. As long as the structure of technical solution one is available, other structures can also be appropriately modified.

Claims

1. A vehicle, wherein, The rigidity balance of the vehicle is adjusted so that the node of torsional deformation generated when the vehicle is steered is located within the driver's seat range in the forward and backward direction of the vehicle.

2. The vehicle according to claim 1, wherein, The vehicle's front-to-rear weight balance is adjusted so that the vehicle's center of gravity is located within the range of the driver's seat in the front-to-rear direction.

3. The vehicle according to claim 1, wherein, The vehicle also has a battery located under the floor of the vehicle. Multiple side fastening points are provided at both ends of the battery in the vehicle width direction for securing the battery to the vehicle frame. The density of the side fastening points in the vehicle's longitudinal direction, located behind the center of the battery, is higher than the density of the side fastening points in the vehicle's longitudinal direction, located in front of the center of the battery.

4. The vehicle according to claim 3, wherein, The battery is further provided with multiple front fastening points and multiple rear fastening points at its front and rear ends for securing the battery to the vehicle frame. The density of the front fastening points and the rear fastening points is higher than the density of the side fastening points located in the front-to-back direction of the vehicle, which are further forward than the center of the battery.

5. The vehicle according to claim 1, wherein, It also has: The front body, including a pair of wheel arches, is integrally formed by casting; The rear body, including a pair of wheel arches, is integrally formed by casting. The battery is located under the floor of the vehicle; as well as The electric motor is located behind the driver's seat.

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