Undercover fastening structure

Abstract

To provide an undercover fastening structure making it possible to upgrade the aerodynamic performance of a vehicle.SOLUTION: An undercover fastening structure includes a fuel tank 12 disposed below the floor of a vehicle 10, a first undercover 20 that covers the fuel tank 12 from below, and a coupling bracket 30 that mechanically couples the first undercover 20 to fixing members. The coupling bracket 30 is fastened to the upper surface of the first undercover 20, and is also fastened to the fixing members at both ends in a fore-and-aft direction across the fuel tank 12.SELECTED DRAWING: Figure 2

Description

Technical Field

[0005]

[0001] This specification discloses a fastening structure for an under cover disposed under the floor of a vehicle.

Background Art

[0002] Conventionally, it has been proposed to dispose a fuel tank under the floor of a vehicle. In this case, due to the unevenness generated on the lower surface of the vehicle caused by the fuel tank, the aerodynamic performance may deteriorate. Therefore, in some cases, an under cover for covering the fuel tank from below has been proposed. For example, Patent Document 1 discloses a vehicle in which a fuel tank and a main battery are covered with an under cover.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, when such an under cover is directly fastened to the bottom surface of the fuel tank, sufficient aerodynamic performance cannot be obtained. That is, depending on the driving conditions, the internal pressure of the fuel tank may change greatly, and the entire tank may expand and contract. When the under cover is directly fastened to such a fuel tank, the fastening portion of the under cover with the fuel tank is displaced up and down as the fuel tank expands and contracts. As a result, in this case, unevenness and steps are generated on the under cover, and high aerodynamic performance cannot be maintained. <e000027> Therefore, this specification discloses a fastening structure for an under cover that can further improve the aerodynamic performance of a vehicle.

Means for Solving the Problems

[0007] This configuration prevents the first underbody cover from being affected by the expansion and contraction of the fuel tank, thus effectively preventing deformation of the first underbody cover. As a result, the vehicle's aerodynamic performance can be further improved.

[0008] In this case, the vehicle further comprises a main battery positioned adjacent to the fuel tank in the front-rear direction, and a second under cover covering the battery from below. The first under cover and the second under cover may be separate components positioned in the same plane, or a single component integrally connected to each other.

[0009] By covering both the fuel tank and the main battery with an underbody cover positioned on the same plane, the vehicle's aerodynamic performance can be further improved.

[0010] Furthermore, the fixing member may include a vehicle frame member and the housing of the main battery or a support frame supporting the main battery, and the connecting bracket may have a first fastening portion fastened to the housing or the support frame and a second fastening portion located on the opposite side of the fuel tank from the first fastening portion and fastened to the vehicle frame member.

[0011] This configuration allows the connecting bracket to be properly fastened to the fixing member.

[0012] Furthermore, the connecting bracket has a cover fastening portion that is fastened to the first under cover, and at least one of the first fastening portion and the second fastening portion may be located above the vehicle relative to the cover fastening portion.

[0013] This configuration makes it easier for the first underbody cover to deform downwards during a frontal or rear-end collision, rather than upwards. As a result, interference between the first underbody cover and the fuel tank, and consequently damage to the fuel tank, can be effectively prevented.

[0014] Furthermore, the connecting bracket has a cover fastening portion that is fastened to the first under cover by a fastening member, the fastening member has a head and a shaft portion that protrudes from the head, and is assembled to the connecting bracket in a position where the head is above the shaft portion above the vehicle, and the cover fastening portion may be locally recessed compared to the surrounding area.

[0015] This configuration effectively prevents interference between the shaft of the fastening member and the fuel tank, even when the connecting bracket is subjected to an upward load. As a result, damage to the fuel tank can be effectively prevented. [Effects of the Invention]

[0016] The underbody fastening structure disclosed herein can further improve the aerodynamic performance of the vehicle. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram of the vehicle viewed from below. [Figure 2] This is a cross-sectional view AA in Figure 1. [Figure 3] This is an enlarged view of section B in Figure 2. [Modes for carrying out the invention]

[0018] Hereinafter, the attachment structure of the under cover will be described with reference to the drawings. FIG. 1 is a schematic view of the vehicle 10 seen from below. Further, FIG. 2 is a cross-sectional view taken along the line A-A of FIG. 1. Furthermore, FIG. 3 is an enlarged view of part B in FIG. 2. In each figure, "Fr", "Up", and "Rh" indicate the front of the vehicle, the upper part of the vehicle, and the right side of the vehicle, respectively.

[0019] The vehicle 10 shown in FIG. 1 is a hybrid electric vehicle equipped with both an engine and a motor (both not shown) as power sources of the vehicle 10. In the case of the example in FIG. 1, both the engine and the motor are arranged at the front part of the vehicle 10.

[0020] Under the floor of the vehicle 10, that is, below the floor panel 32, a main battery 14, a fuel tank 12, and an exhaust pipe 16 are arranged. The main battery 14 stores electric power to be supplied to the motor. This main battery 14 is a secondary battery capable of discharging and charging. The main battery 14 has a flat shape with a small thickness compared to its outer dimensions. Such a main battery 14 is arranged as low as possible to secure a wide interior space. Also, the main battery 14 is arranged substantially at the center of the vehicle 10. Further, the housing 36 of the main battery 14 is assembled to the battery support frame 34, and the battery support frame 34 is fixed to the vehicle 10.

[0021] The fuel tank 12 is a tank that stores fuel to be supplied to the engine. This fuel tank 12 is arranged adjacent to the rear of the vehicle of the main battery 14. As shown in FIG. 2, the vertical dimension of the fuel tank 12 is significantly larger than the vertical dimension of the main battery 14. The fuel tank 12 is assembled to the tank support frame 38, and the tank support frame 38 is fixed to the vehicle 10.

[0022] The exhaust pipe 16 is a pipe that guides the exhaust discharged from the engine to the main muffler. As shown in FIG. 1, the exhaust pipe 16 passes by the side of the main battery 14 in the process from the engine to the main muffler. The exhaust pipe 16 becomes very hot during the operation of the engine.

[0023] Here, the components arranged under the floor of the vehicle 10 are covered from below by the undercovers 20, 22, and 24. In FIG. 1, a first undercover 20 covering the fuel tank 12, a second undercover 22 covering the main battery 14, and a side undercover 24 arranged on the right side of the exhaust pipe 16 are illustrated.

[0024] The undercovers 20, 22, and 24 are all panel members made of resin, and their bottom surfaces are substantially flat. In FIG. 1, the undercovers 20, 22, and 24 are hatched. Such undercovers 20, 22, and 24 are provided to improve aerodynamic performance, and thus to improve fuel consumption and electricity consumption and reduce the amount of carbon emissions.

[0025] That is, if the undercovers 20, 22, and 24 are not provided, the bottom surface of the vehicle 10 is constructed by the main battery 14 and the fuel tank 12. And in this case, there will be a large number of irregularities on the bottom surface of the vehicle 10. Such irregularities cause air stagnation and turbulence. As a result, if the undercovers 20, 22, and 24 are not provided, the air flow between the vehicle 10 and the road surface becomes poor, and the aerodynamic performance deteriorates. On the other hand, when the undercovers 20, 22, and 24 are provided, the bottom surface of the vehicle 10 becomes a substantially flat surface, so that air stagnation and turbulence are less likely to occur, and the air flow becomes smooth. As a result, the aerodynamic performance of the vehicle 10 is improved. Incidentally, as described above, the undercovers 20, 22, and 24 are made of resin and have a low heat-resistant temperature. Therefore, the undercovers 20, 22, and 24 are arranged avoiding the high-temperature exhaust pipe 16. Specifically, the undercovers 20, 22, and 24 are arranged divided into the left and right sides sandwiching the exhaust pipe 16.

[0026] As shown in Figure 1, the first under cover 20 and the second under cover 22 are arranged side by side, front to back. To improve aerodynamic performance, the first under cover 20 and the second under cover 22 are assembled so that they are located in approximately the same plane as each other. In addition, in this example, a connecting bracket 30 is provided to prevent the first under cover 20 from deforming even if the fuel tank 12 deforms.

[0027] The connecting bracket 30 is a component made of a rigid material such as metal, and is a roughly flat, elongated component in one direction. In this example, the connecting bracket 30 is positioned at an angle with respect to the vehicle's longitudinal direction, so that it moves in the vehicle's width direction as it moves towards the rear of the vehicle. By positioning the connecting bracket 30 at an angle in this way, it can withstand forces in both the longitudinal and vehicle width directions.

[0028] This connecting bracket 30 is fastened to the vehicle 10's fixing members, specifically the battery support frame 34 and the rear suspension member 40. The first under cover 20 is also fastened to the bottom surface of this connecting bracket 30. Therefore, the first under cover 20 is connected to the fixing members via the connecting bracket 30. In other words, in this example, the first under cover 20 is not fastened to the bottom surface of the fuel tank 12. This configuration prevents deformation of the first under cover 20 and maintains high aerodynamic performance. The reason for this will be explained below.

[0029] The internal pressure of the fuel tank 12 changes significantly depending on the operating environment and driving conditions. This change in internal pressure causes the fuel tank 12 itself to expand and contract. If the first under cover 20 is fastened to the bottom of the fuel tank 12, the first under cover 20 will deform as the fuel tank 12 expands and contracts. This deformation creates irregularities on the first under cover 20, which in turn worsens airflow and reduces aerodynamic performance. Therefore, as shown in Figure 2, the first under cover 20 is positioned below the bottom of the fuel tank 12. This effectively prevents deformation of the first under cover 20 even when the fuel tank 12 expands and contracts.

[0030] However, if the first under cover 20 is simply separated from the fuel tank 12, in other words, if the connecting bracket 30 is not used, a problem arises in that the rigidity of the first under cover 20 is insufficient. For example, consider the case where the front and rear ends of the first under cover 20 are fastened to a fixing member. In this case, the central part of the first under cover 20 is prone to bending and cannot maintain sufficient rigidity. Therefore, if the connecting bracket 30 is not used, the size of the first under cover 20 must be reduced in order to ensure rigidity, which leads to a decrease in aerodynamic performance.

[0031] On the other hand, in this example, a connecting bracket 30 made of a rigid material is provided, and the first under cover 20 is fastened to this connecting bracket 30. This ensures sufficient rigidity even if the size of the first under cover 20 is increased. As a result, almost the entire fuel tank 12 can be covered by the first under cover 20, improving aerodynamic performance. Also, as shown in Figure 2, in this example, both the connecting bracket 30 and the first under cover 20 are located away from the fuel tank 12. Therefore, even if the fuel tank 12 expands or contracts, deformation of the connecting bracket 30 and the first under cover 20 is prevented.

[0032] Next, the configuration of the connecting bracket 30 will be described in more detail. As mentioned above, the connecting bracket 30 is an elongated, flat plate-shaped member made of metal. A first fastening portion 54 is provided at the front end of the connecting bracket 30. The connecting bracket 30 is fastened to the battery support frame 34 at this first fastening portion 54 by a fastening member 42a. The fastening member 42a is, for example, a bolt having a head 44 and a shaft portion 50 protruding from the head 44. However, the fastening member 42a is not limited to a bolt and may be other members. For example, the fastening member 42a may be a rivet or a clip.

[0033] A second fastening portion 56 is provided at the rear end of the connecting bracket 30. The connecting bracket 30 is fastened to the rear suspension member 40 by a fastening member 42a at this second fastening portion 56. As is clear from Figure 2, the second fastening portion 56 is located on the opposite side of the first fastening portion 54, with the fuel tank 12 in between. In other words, the connecting bracket 30 is fastened to the fixing member on both sides in the front-rear direction, with the fuel tank 12 in between.

[0034] Multiple cover fastening portions 58 are provided on the general surface 52 of the connecting bracket 30. The connecting bracket 30 is fastened to the first under cover 20 by fastening members 42b at these cover fastening portions 58. The fastening member 42b is a bolt having a head 44 and a shaft portion 50 protruding from the head 44, similar to the fastening member 42a.

[0035] As is clear from Figure 2, the front and rear ends of the connecting bracket 30 rise above the general surface 52 of the connecting bracket 30, and the first fastening portion 54 and the second fastening portion 56 are provided on these rising portions 53. In other words, the first fastening portion 54 and the second fastening portion 56 are located above the general surface 52, and consequently above the cover fastening portion 58, which will be described later. With this configuration, when a force in the longitudinal direction of the vehicle is applied to the first fastening portion 54 or the second fastening portion 56 due to a frontal or rearward collision, the deformation of the first under cover 20 is more likely to be a deformation that is convex downward rather than convex upward. This effectively prevents interference between the first under cover 20 and the fuel tank 12, and consequently damage to the fuel tank 12, even in the event of a collision.

[0036] Furthermore, as shown in Figure 3, in the cover fastening portion 58, the fastening member 42b is assembled in such a position that its head 44 is above its shaft portion 50. Also, the cover fastening portion 58 is locally recessed compared to its surrounding area. This configuration prevents the sharp shaft portion 50 from colliding with the fuel tank 12.

[0037] In other words, as the vehicle 10 moves, road surface obstacles may collide with the first under cover 20 or the connecting bracket 30, pushing the cover fastening portion 58 upward. As shown in Figure 3, if the cover fastening portion 58 is recessed compared to the surrounding area, even when subjected to an upward force, the surrounding general surface 52, rather than the cover fastening portion 58, will first come into contact with the bottom surface of the fuel tank 12. This contact effectively prevents the cover fastening portion 58, and consequently the hard fastening member 42b, from colliding with the bottom surface of the fuel tank 12. Furthermore, in this example, the head 44 of the fastening member 42b is positioned above the shaft portion 50. Therefore, even if the area around the cover fastening portion 58 is lifted high, the sharp shaft portion 50 will not collide with the fuel tank 12. As a result, damage to the fuel tank 12 is effectively prevented.

[0038] As is clear from the above explanation, with the fastening structure of the under cover disclosed herein, the first under cover 20 is not fastened to the fuel tank 12, so even if the fuel tank 12 expands or contracts, the first under cover 20 does not deform. In addition, the rigidity of the first under cover 20 is reinforced by the connecting bracket 30, so the first under cover 20 can be made larger. As a result, with the fastening structure disclosed herein, the aerodynamic performance of the vehicle 10 is improved, and consequently, fuel efficiency and electricity consumption are improved, and carbon emissions are reduced.

[0039] It should be noted that the configurations described above are all examples, and the fastening structure may be modified as appropriate, as long as it has the configuration described in claim 1. For example, in the above description, the first under cover 20 and the second under cover 22 are treated as separate parts. However, the two under covers 20 and 22 may be a single component that is integrally connected to each other. Also, in the above description, the connecting bracket 30 is fastened to the battery support frame 34 and the rear suspension member 40. However, the connecting bracket 30 may be fastened to other components of the vehicle, as long as they are fixed members that are substantially stationary with respect to the fuel tank 12. For example, the connecting bracket 30 may be fastened to the housing 36 of the main battery 14 at the first fastening part 54. Also, the connecting bracket 30 may be fastened to other vehicle frame members such as a cross member at the second fastening part 56. Furthermore, the posture of the fastening member 42 and the shape around the cover fastening part 58 may also be modified as appropriate. [Explanation of symbols]

[0040] 10 Vehicle, 12 Fuel tank, 14 Main battery, 16 Exhaust pipe, 20 First under cover, 22 Second under cover, 24 Side under cover, 30 Connecting bracket, 32 Floor panel, 34 Battery support frame (fixing member), 36 Housing, 38 Tank support frame, 40 Rear suspension member (fixing member), 42 Fastening member, 44 Head, 50 Shaft section, 52 General surface, 53 Rising section, 54 First fastening section, 56 Second fastening section, 58 Cover fastening section.

Claims

1. The fuel tank located under the vehicle floor, The first under cover covers the fuel tank from below, A connecting bracket for mechanically connecting the first under cover to a fixing member, the connecting bracket being fastened to the upper surface of the first under cover and fastened to the fixing member on both the front and rear sides of the fuel tank, Equipped with, The connecting bracket has a cover fastening portion that is fastened to the first under cover by a fastening member, The fastening member has a head and a shaft portion protruding from the head, and is assembled to the connecting bracket in a position where the head is above the vehicle relative to the shaft portion. The cover fastening portion is locally recessed compared to the surrounding area. A fastening structure for an undercover characterized by the following features.

2. The fastening structure for the under cover according to claim 1, further, In the vehicle's front-to-rear direction, the main battery is located adjacent to the fuel tank, The second under cover covers the main battery from below, The first under cover and the second under cover are separate members arranged in the same plane, or a single member integrally connected to each other. A fastening structure for an undercover characterized by the following features.

3. The fastening structure for the under cover according to claim 2, The fixing member includes a vehicle frame member and the housing of the main battery or a support frame that supports the main battery. The aforementioned connecting bracket is A first fastening portion fastened to the housing or the support frame, A second fastening portion is located on the opposite side of the first fastening portion, with the fuel tank in between, and is fastened to the vehicle frame member. An undercover fastening structure characterized by having the following:

4. The fastening structure for the under cover according to claim 3, The connecting bracket has a cover fastening portion that is fastened to the first under cover, At least one of the first fastening portion and the second fastening portion is located above the vehicle, A fastening structure for an undercover characterized by the following features.

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