Vehicle structure of electric vehicles

Abstract

To provide a vehicle structure of an electric-motor car, capable of suppressing the aerodynamic drag of a vehicle while traveling.SOLUTION: A vehicle structure V of an electric-motor car includes: a radiator 1; a power unit 6 of the electric-motor car; and a power supply section 5 for supplying electric power to the power unit 6. One of the power unit 6 and the power supply section 5 has a cover member 3 with an opposing surface 3S receiving the wind passing through the radiator 1 and the opposing surface 3S has a downward inclined surface 31 inclined so that a distance from the radiator 1 along the cross direction of a vehicle becomes larger toward a downward end 3U of the opposing surface 3S, or width direction inclined surfaces 33, 34 inclined so that a distance from the radiator 1 along the cross direction of the vehicle becomes larger toward at least one of width direction ends 3L, 3R of the opposing surface 3S.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle structure for an electric vehicle. [Background Art]

[0002] With the electrification of automobiles, the power unit serving as the power source has been replaced from an engine to an electric motor. Patent Document 1 below describes an electric vehicle using an electric motor as a power source, which can effectively utilize heat generated from electrical equipment. [Prior Art Document] [Patent Document]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2021-115951 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the electric vehicle described in Patent Document 1, electrical equipment such as a power control unit 20 to be cooled is provided downstream of a radiator 22, and air that has passed through the radiator hits this electrical equipment. Therefore, a problem arises in that the aerodynamic resistance of the vehicle during traveling increases due to this electrical equipment. As a result, the fuel efficiency of the vehicle during traveling deteriorates.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a vehicle structure for an electric vehicle capable of suppressing the aerodynamic resistance of the vehicle during traveling. [Means for Solving the Problem]

[0006] To solve the above-mentioned problems, the vehicle structure of an electric vehicle according to the present invention comprises a radiator, a power unit of the electric vehicle, and a power supply unit for supplying power to the power unit, wherein one of the power unit and the power supply unit has a cover member having an opposing surface that receives air passing through the radiator, and the opposing surface has a downward inclined surface that is inclined such that the distance from the radiator in the longitudinal direction of the vehicle increases as it approaches the lower end of the opposing surface, or a widthwise inclined surface that is inclined such that the distance from the radiator in the longitudinal direction of the vehicle increases as it approaches at least one of the widthwise ends of the opposing surface.

[0007] According to the vehicle structure of the electric vehicle according to the present invention, the air that passes through the radiator and reaches the cover member is more likely to flow downward or in the width direction due to the presence of the downward sloping surface or the widthwise sloping surface on the opposing surface, and is guided into the space below or in the width direction of either the power unit or the power supply section. As a result, the airflow becomes smoother, and the aerodynamic resistance of the vehicle during driving is suppressed.

[0008] Furthermore, in the vehicle structure of the electric vehicle according to the present invention, the opposing surface may have both the downward-sloping surface and the widthwise-sloping surface. As a result, the air that passes through the radiator and reaches the cover member is guided to both the space below one of the power unit and the power supply unit and the space in the widthwise direction, thereby increasing the amount of air passing through the radiator. Consequently, it is possible to increase the amount of air passing through the radiator while suppressing the aerodynamic drag of the vehicle during driving. [Effects of the Invention]

[0009] According to the present invention, a vehicle structure for an electric vehicle is provided that can suppress the aerodynamic resistance of the vehicle while it is running. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows a schematic longitudinal cross-section of the vehicle structure of an electric vehicle according to the first embodiment. [Figure 2] This is a three-view drawing showing a cover member according to the first embodiment. [Figure 3] This is a three-view drawing showing the cover member of the second embodiment. [Figure 4] This is a three-view drawing showing the cover member of the third embodiment. [Figure 5] This is a diagram illustrating the vehicle model in the simulation. [Figure 6] This is a diagram illustrating the vehicle model in the simulation. [Figure 7] This is a diagram illustrating the vehicle model in the simulation. [Figure 8] This is a diagram illustrating the vehicle model in the simulation. [Figure 9] This is a diagram illustrating the vehicle model in the simulation. [Figure 10] This is a diagram illustrating the vehicle model in the simulation. [Figure 11] This is a diagram illustrating the vehicle model in the simulation. [Figure 12] This figure corresponds to the table showing the calculation results of the simulation. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the attached drawings. In each drawing, the same reference numerals are used for the same elements where possible. Furthermore, the dimensional ratios within and between components in the drawings are arbitrary for the sake of readability.

[0012] (First Embodiment) Figure 1 is a schematic longitudinal cross-section of the vehicle structure of an electric vehicle according to the first embodiment of the present invention, viewed from the width direction, and shows the structure of the front part of the electric vehicle. A vehicle structure V according to the first embodiment is a structural section that forms part of an electric vehicle such as an electric vehicle, a hybrid vehicle, a plug-in hybrid vehicle, or a fuel cell vehicle. FIG. 1 shows, by way of example, a vehicle structure that forms part of an electric truck. As shown in FIG. 1, the vehicle structure V includes a radiator 1, a power supply unit 5 having a cover member 3 and a power supply main body 4, and a power unit 6. In addition to the vehicle structure V, the electric vehicle including the vehicle structure V includes a front chassis 7, a cab windshield 8, a rear chassis 9, a body 10, front wheel tires 11, a cab front panel 12, and an air deflector 13.

[0013] The radiator 1 is provided in an opening 7A formed in the front chassis 7. The radiator 1 is an air-cooled heat exchanger through which a cooling refrigerant for the power unit 6 and / or the power supply main body 4 circulates. When the electric vehicle travels, wind from outside the electric vehicle passes through the radiator 1, and at this time, the refrigerant is cooled by the wind inside the radiator 1.

[0014] The power unit 6 includes a drive motor as a power source for causing the electric vehicle to travel, and may further include an engine depending on the type of the electric vehicle. The power unit 6 is provided on the rear chassis 9. The power supply main body 4 includes a battery, a fuel cell, and the like for supplying driving electric power to the drive motor of the power unit 6. The cover member 3 is provided at a front portion of the power supply main body 4 (the front side in the traveling direction of the electric vehicle), and is provided so as to cover all or part of a region of the power supply main body 4 that would be exposed to wind that has passed through the radiator 1 during traveling if the cover member 3 is not present. The cover member 3 has a facing surface 3S. The facing surface 3S receives part or all of the wind that has passed through the radiator 1 during traveling. The cover member 3 is provided so as to be in contact with the power supply main body 4 or spaced apart from the power supply main body 4. The cover member 3 is formed of, for example, a steel plate, an aluminum plate, a resin member, or the like.

[0015] Figure 2 is a three-view drawing of the cover member. The front view (lower left) of the three-view drawing in Figure 2 shows the cover member 3 viewed from the front to the rear along the longitudinal direction of the vehicle; the top view (upper) shows the cover member 3 viewed from the top to the bottom along the vertical direction of the vehicle; and the right side view (lower right) shows the cover member 3 viewed from the left to the right along the width direction of the vehicle. The same applies to the three-view drawings in Figures 3 and 4 described later.

[0016] As shown in Figure 2, the opposing surface 3S of the cover member 3 in this embodiment has a downward inclined surface 31 that is inclined such that the distance from the radiator 1 (see Figure 1) along the longitudinal direction of the vehicle increases as it approaches the lower end 3U of the opposing surface 3S. Preferably, the downward inclined surface 31 extends to the lower end 3U of the opposing surface 3S in the vertical direction of the vehicle. The downward inclined surface 31 may extend from the upper end 3T of the opposing surface 3S toward the lower end 3U in the vertical direction of the vehicle, or it may extend from the midpoint of the opposing surface 3S in the vertical direction of the vehicle toward the lower end 3U. Alternatively, the downward inclined surface 31 may extend from the upper end 3T of the opposing surface 3S toward the lower end 3U in the vertical direction of the vehicle (i.e., the entire opposing surface 3S may be composed of the downward inclined surface 31), or it may extend from the midpoint of the opposing surface 3S in the vertical direction of the vehicle toward the lower end 3U.

[0017] As shown in Figure 2, the downward inclined surface 31 of this embodiment has a curved shape in a longitudinal cross-section viewed from the width direction of the vehicle, and has an arc shape with its center point behind the downward inclined surface 31 in the front-rear direction of the vehicle. However, it may also have other curved shapes or straight shapes.

[0018] According to the vehicle structure V of the electric vehicle according to this embodiment described above, the air that passes through the radiator 1 and reaches the cover member 3 is more likely to flow downwards due to the presence of the downwardly inclined surface 31 on the opposing surface 3S of the cover member 3, and is guided into the space below the power supply unit 5 (see Figures 1 and 2), and this space is in communication with the space outside the electric vehicle. As a result, the airflow that passes through the radiator 1 becomes smoother, and the aerodynamic resistance of the vehicle during driving is suppressed.

[0019] (Second Embodiment) Next, the vehicle structure of an electric vehicle according to the second embodiment of the present invention will be described. The vehicle structure of the second embodiment differs from the vehicle structure of the first embodiment in terms of the shape of the cover member. Figure 3 is a three-view drawing showing the cover member of the second embodiment.

[0020] As shown in Figure 3, the opposing surface 3S2 of the cover member 3B in this embodiment has widthwise inclined surfaces 33 and 34 that are inclined such that the distance from the radiator 1 (see Figure 1) along the longitudinal direction of the vehicle increases as they approach the widthwise ends 3L and 3R of the opposing surface 3S2. Preferably, the widthwise inclined surfaces 33 and 34 extend to the widthwise ends 3L and 3R of the opposing surface 3S2 in the width direction of the vehicle. The widthwise inclined surfaces 33 and 34 may be directly connected to each other in the width direction of the vehicle and extend toward the widthwise ends 3L and 3R, respectively, or they may be connected to each other via other surfaces that are not inclined to increase the distance from the radiator 1 (see Figure 1) and extend toward the widthwise ends 3L and 3R, respectively. Furthermore, the widthwise inclined surfaces 33 and 34 may be directly connected to each other in the width direction of the vehicle and extend to their respective widthwise ends 3L and 3R (i.e., the entire opposing surface 3S2 may be composed of the widthwise inclined surfaces 33 and 34), or they may be connected to each other via other non-inclined surfaces so as to increase the distance from the radiator 1 (see Figure 1) and extend to their respective widthwise ends 3L and 3R.

[0021] In this embodiment, the widthwise inclined surfaces 33 and 34 each have a curved shape in a cross-section viewed from the vertical direction of the vehicle, as shown in Figure 3, and have an arc shape with the center point located behind the widthwise inclined surfaces 33 and 34 in the longitudinal direction of the vehicle. However, they may also have other curved shapes or straight shapes. Furthermore, the opposing surface 3S2 may have only one of the widthwise inclined surfaces 33 and 34 as its widthwise inclined surface.

[0022] According to the vehicle structure V of the electric vehicle according to this embodiment described above, the air that passes through the radiator 1 (see Figure 1) and reaches the cover member 3B is more easily guided in the width direction of the cover member 3B by the presence of the width-direction inclined surfaces 33 and 34 of the opposing surface 3S2 of the cover member 3B, and is led into the space in the width direction of the power supply unit (see Figures 1 and 2), and this space is in communication with the space outside the electric vehicle. As a result, the airflow that passes through the radiator 1 becomes smoother, and the aerodynamic resistance of the vehicle during driving is suppressed.

[0023] (Third embodiment) Next, the vehicle structure of an electric vehicle according to the third embodiment of the present invention will be described. The vehicle structure of the third embodiment differs from the vehicle structures of the first and second embodiments in terms of the shape of the cover member. Figure 4 is a three-view drawing showing the cover member of the third embodiment.

[0024] As shown in Figure 4, the opposing surface 3S3 of the cover member 3C in this embodiment has downward widthwise inclined surfaces 35 and 36 such that the distance from the radiator 1 (see Figure 1) along the longitudinal direction of the vehicle increases as you move toward the lower end 3U of the opposing surface 3S3, and the distance from the radiator 1 (see Figure 1) along the longitudinal direction of the vehicle increases as you move toward the widthwise ends 3L and 3R of the opposing surface 3S3. Therefore, the opposing surface 3S3 of the cover member 3C in this embodiment has both the downward inclined surface 31 of the first embodiment (see Figure 2) and the widthwise inclined surfaces 33 and 34 of the second embodiment (see Figure 3) combined as downward widthwise inclined surfaces 35 and 36.

[0025] Preferably, the downward widthwise inclined surfaces 35 and 36 extend to the lower end 3U of the opposing surface 3S3 in the vertical direction of the vehicle, and preferably extend to the widthwise ends 3L and 3R of the opposing surface 3S3 in the width direction of the vehicle.

[0026] The downward widthwise inclined surfaces 35 and 36 may each extend in the vertical direction of the vehicle from the upper end 3T of the opposing surface 3S3 toward the lower end 3U, or from the midpoint of the opposing surface 3S3 in the vertical direction of the vehicle toward the lower end 3U. The downward widthwise inclined surfaces 35 and 36 are connected to each other via the curved surface 37 in the width direction of the vehicle and extend toward the widthwise ends 3L and 3R, respectively, but they may also be directly connected to each other and extend toward the widthwise ends 3L and 3R, respectively.

[0027] Furthermore, the downward widthwise inclined surfaces 35 and 36 may extend in the vertical direction of the vehicle from the upper end 3T of the opposing surface 3S3 to the lower end 3U, or from the midpoint of the opposing surface 3S3 in the vertical direction of the vehicle to the lower end 3U. Also, the downward widthwise inclined surfaces 35 and 36 may be connected to each other via a curved surface 37 and extend to their respective widthwise ends 3L and 3R, or they may be directly connected to each other and extend to their respective widthwise ends 3L and 3R.

[0028] As shown in Figure 4, the downward widthwise inclined surfaces 35 and 36 each have a curved shape in the longitudinal section viewed from the width direction of the vehicle, and have an arc shape with the center point located behind the downward widthwise inclined surfaces 35 and 36 in the front-rear direction of the vehicle, but they may also have other curved shapes or straight shapes.

[0029] Furthermore, as shown in Figure 4, the downward widthwise inclined surfaces 35 and 36 each have a straight shape in a cross-section viewed from the vertical direction of the vehicle, but they may also have a curved shape, such as an arc, with its center point further rear in the longitudinal direction of the vehicle than the widthwise inclined surfaces 33 and 34. Also, the opposing surface 3S3 may have only one of the downward widthwise inclined surfaces 35 and 36.

[0030] According to the vehicle structure V of the electric vehicle according to this embodiment described above, since the opposing surface 3S3 has downward width-sloping surfaces 35 and 36, the air that passes through the radiator 1 and reaches the cover member 3C is guided to both the space below the power supply unit and the space in the width direction (see Figures 1 and 2), and this space is in communication with the space outside the electric vehicle. As a result, the amount of air passing through the radiator 1 increases. Consequently, it is possible to increase the amount of air passing through the radiator 1 while suppressing the aerodynamic resistance of the vehicle during driving.

[0031] (simulation) Next, we will describe the simulations conducted by the present inventors to further clarify the effects of the present invention.

[0032] The inventors of this application performed numerical simulation analysis on each of the models of Examples 1 to 3 and Comparative Example 1 using the unstructured grid thermal fluid analysis system SCRYU / Tetra Version 12 (manufactured by Software Cradle Co., Ltd.). Figures 5 to 11 are diagrams illustrating the vehicle model used in this simulation.

[0033] (Example 1) A vehicle having the vehicle structure of the first embodiment described above was modeled as Example 1. Figure 1 is a front view of the vehicle model of Example 1, and Figure 2 is a right side view of the vehicle model of Example 1. Figure 3 is a schematic enlarged view of the front view of the vehicle model of Figure 1, and Figure 4 is a schematic longitudinal section of the vehicle model of Example 1 viewed from the width direction, corresponding to Figure 1. As shown in these figures, a large vehicle (cargo) was modeled as Example 1. As shown in Figures 5 and 6, this large vehicle model was placed in a space with a length of 75 m, a width of 17.5 m, and a height of 11 m, in the positional relationship shown in these figures. For this space, the pressure was atmospheric pressure, the temperature was 20°C (incompressible), and the density was 1.206 kg / m³. 3The following settings were established. As shown in Figures 7 and 8, the external dimensions of the radiator 1 were set to a width of 1620 mm, a height of 855 mm, and a thickness of 50 mm, and the external dimensions of the power supply unit 4 were set to a width of 980 mm, a height of 1100 mm, and a depth of 1130 mm. The distance between the radiator 1 and the power supply unit 4 was set to 365 mm. Figure 9 is a three-view drawing of the cover member 3 of the vehicle model of Embodiment 1, corresponding to Figure 2. As shown in Figure 9, the width of the cover member 3 was set to 980 mm, the height to 1100 mm, and the maximum thickness to 350 mm. The radius of curvature of the downward inclined surface 31 in the longitudinal section viewed from the width direction of the vehicle was set to 1850 mm.

[0034] (Example 2) A vehicle having the vehicle structure of the second embodiment described above was modeled as Example 2. That is, the vehicle model of Example 2 differs from the vehicle model of Example 1 in terms of the shape of the cover member, but is otherwise the same as the vehicle model of Example 1. Figure 10 is a three-view drawing of the cover member 3B of the vehicle model of Example 2, corresponding to Figure 3. As shown in Figure 10, the width of the cover member 3B is 980 mm, the height is 1100 mm, and the maximum thickness is 300 mm. The radius of curvature of the widthwise inclined surfaces 33 and 34 in the cross-section viewed from the vertical direction of the vehicle is 550 mm.

[0035] (Example 3) A vehicle having the vehicle structure of the third embodiment described above was modeled as Example 3. That is, the vehicle model of Example 3 differs from the vehicle models of Examples 1 and 2 in terms of the shape of the cover member, but is otherwise the same as the vehicle models of Examples 1 and 2. Figure 11 is a three-view drawing of the cover member 3C of the vehicle model of Example 3, corresponding to Figure 4. As shown in Figure 11, the width of the cover member 3C is 980 mm, the height is 1100 mm, and the maximum thickness is 350 mm. The radius of curvature of the downward widthwise inclined surfaces 35 and 36 in the longitudinal section viewed from the width direction of the vehicle is 1900 mm, and the radius of curvature of the curved surface 37 in the cross section viewed from the up and down direction of the vehicle is 200 mm.

[0036] (Comparative Example 1) Comparative Example 1 is a model of a vehicle that differs from the vehicles of Examples 1 to 3 in that it does not have a cover member, but is otherwise the same as the vehicles of Examples 1 to 3.

[0037] For each of the vehicle models in Examples 1-3 and Comparative Example 1 described above, a simulation was conducted in which wind at a speed of 80 km / h was blown from the front to the rear of the vehicle to reproduce the condition of driving at 80 km / h. Then, under that condition, the aerodynamic drag of each vehicle model, including the aerodynamic drag caused by the air passing through the radiator and hitting the opposing surface of the cover member, and the airflow rate passing through the radiator of each vehicle model were calculated.

[0038] Figure 12 is a diagram corresponding to the table showing the calculation results of the above simulation. In the table shown in Figure 12, the horizontal axis represents the Cd value (coefficient of air resistance), which is a value normalized with the value in Comparative Example 1 set to 100%, and the vertical axis represents the RAD flow rate (flow rate of air passing through the radiator). As shown in Figure 12, the Cd values ​​of Examples 1 to 3 were all smaller than the Cd value of Comparative Example 1. Specifically, the Cd value of Example 1 was 97.1%, the Cd value of Example 2 was 97.8%, and the Cd value of Example 3 was 99.1%. In addition, the RAD flow rates of Examples 1 and 2 were smaller than the RAD flow rate of Comparative Example 1, and the RAD flow rate of Example 3 was larger than that of Comparative Example 1. Specifically, the RAD flow rate of Example 1 was 478 m³. 3 The RAD flow rate in Example 2 was 511 m³ / min. 3 The RAD flow rate in Example 3 was 539 m³ / min. 3 The RAD flow rate in Comparative Example 1 was 534 m³ / min. 3 It was / minutes.

[0039] These results show that in all three Examples 1-3, the aerodynamic drag of the vehicle during driving was suppressed compared to Comparative Example 1. In particular, in Example 3, it was found that not only was the aerodynamic drag of the vehicle during driving suppressed, but the amount of air passing through the radiator also increased.

[0040] The present invention is not limited to the embodiments described above, and various modifications are possible. For example, in the first to third embodiments described above, the power supply unit 5 had cover members 3, 3B, and 3C (see Figures 1 to 4), but instead, the power unit may have a cover member corresponding to any of the cover members 3, 3B, and 3C. In this case, the power supply main body 4 of the first to third embodiments described above is replaced by the power unit 6 to become the power unit main body, and the power unit is composed of the power unit main body and the cover member 3. In this case as well, for the same reasons as the vehicle structures of the first to third embodiments described above, the effects exhibited by the vehicle structures of each embodiment are achieved. [Explanation of Symbols]

[0041] 1...Radiator, 3, 3B, 3C...Cover members, 3S, 3S2, 3S3...Opposite surfaces of cover members, 3L, 3R...Widthwise ends of opposing surfaces, 3U...Lower end of opposing surfaces, 4...Power supply main unit, 5...Power supply unit, 6...Power unit, 7...Front chassis, 8...Windshield, 9...Rear chassis, 10...Body, 11...Front wheels, 31...Downward inclined surface, 33, 34...Widthwise inclined surfaces.

Claims

1. Radiator and, The power unit of an electric vehicle, A power supply unit for supplying power to the aforementioned power unit, A vehicle structure for an electric vehicle, comprising: One of the power unit and the power supply unit has a cover member having an opposing surface that receives the air that has passed through the radiator. A vehicle structure for an electric vehicle, wherein the opposing surface has a widthwise inclined surface that is inclined such that the distance from the radiator along the longitudinal direction of the vehicle increases toward at least one of the widthwise ends of the opposing surface.

2. The vehicle structure of an electric vehicle according to claim 1, wherein the opposing surface further has a downwardly inclined surface that is inclined such that the distance from the radiator along the longitudinal direction of the vehicle increases as it approaches the lower end of the opposing surface.

Images