Rear structure of the vehicle

Abstract

The present invention provides a rear structure for a vehicle body that can suppress the negative pressure generated at the rear of the vehicle body when subjected to crosswinds. [Solution] The rear structure of the vehicle body of the present invention is a rear structure of a vehicle body that includes a luggage door located behind the rear end of the rear pillar, which covers the upper surface of at least a part of the trunk or luggage space. Furthermore, the vehicle is equipped with a duct that allows air to flow from the lower part of the rear pillar toward the rear of the vehicle body, and the edge shape of the inlet of the duct is such that the rear of the vehicle body is centered in the width direction more than the front of the vehicle body on the outside of the vehicle body. This provides a rear structure for the vehicle body that can suppress negative pressure depending on the direction and strength of the crosswinds the vehicle body is subjected to.

Description

Technical Field

[0001] The present invention relates to the rear structure of a vehicle body, and more particularly, to the aerodynamic treatment of the rear part of the vehicle body.

Background Art

[0002] The air resistance received by a vehicle during driving is generated by the air flow flowing on the vehicle body surface hitting the uneven parts of the vehicle body during driving, peeling off from the vehicle body surface, and a negative pressure is generated by the vortex generated on the downstream side. This negative pressure acts as a force pulling the vehicle backward and has a great influence on the dynamic performance and fuel consumption of the vehicle. Therefore, it is important to reduce the air resistance.

[0003] Particularly, at the rear of the vehicle, since the air flow flowing over the vehicle body is more than the air flow flowing between the bottom of the vehicle body and the road surface, the air flow flowing over the vehicle body bends downward from the rear end of the vehicle body to generate a vortex, strongly pulling the vehicle body backward. Therefore, the control of the air flow at the rear of the vehicle body is more important.

[0004] Patent Document 1 discloses that by narrowing the rear part of the vehicle body inward in the vehicle width direction and forming a crosswind receiving part substantially parallel to the vehicle body front-rear direction in this narrowed part, it is possible to reduce the air resistance and improve the crosswind stability when receiving a crosswind.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, what is described in Patent Document 1 controls the air flow flowing along the side of the vehicle body and flowing downward on the side of the vehicle body to the rear end of the vehicle body, and does not control the air flow flowing upward on the side of the vehicle body.

[0007] Therefore, the airflow that flows along the upper side of the vehicle body, curves towards the center in the width direction behind the cabin, merges with the airflow that has been flowing along the top surface of the vehicle body, flows along the top surface of the luggage door, and then curves downward from the rear end of the vehicle body cannot suppress the negative pressure generated at the rear of the vehicle body.

[0008] This invention has been made in view of the problems of the prior art, and its objective is to provide a rear structure for a vehicle body that can suppress negative pressure generated at the rear of the vehicle body when subjected to crosswinds. [Means for solving the problem]

[0009] The inventors of the present invention have conducted extensive research to achieve the above objectives and have found that the objectives can be achieved by providing a duct that allows air to flow from the lower part of the rear pillar toward the rear of the vehicle body, and by deflecting the edge shape of the duct's inlet toward the center in the vehicle width direction from front to rear on the outside of the vehicle body, thus completing the present invention.

[0010] In other words, the rear structure of the vehicle body of the present invention is a rear structure of a vehicle body that includes a luggage door located behind the rear end of the rear pillar, which covers the upper surface of at least a portion of the trunk or luggage space. Furthermore, the vehicle is equipped with a duct that allows air to flow from the lower part of the rear pillar toward the rear of the vehicle body, and the edge shape of the inlet of the duct is such that, on the outside of the vehicle body, the rear of the vehicle body is centered in the width direction more than the front of the vehicle body. [Effects of the Invention]

[0011] According to the present invention, the edge shape of the inlet of the duct that allows airflow to flow from the lower part of the rear pillar toward the rear of the vehicle body is such that the rear of the vehicle body is located more towards the center in the width direction than the front of the vehicle body on the outside of the vehicle body. As a result, the amount of airflow introduced into the duct changes depending on the direction of the crosswind, and a rear structure of the vehicle body can be provided that can suppress the negative pressure generated at the rear of the vehicle body depending on the direction and strength of the crosswind that the vehicle body is subjected to. [Brief explanation of the drawing]

[0012] [Figure 1] This is a top-down view of the vehicle body illustrating how airflow along the side of the vehicle changes direction at the rear of the cabin. [Figure 2] This diagram, viewed from the rear of the vehicle, illustrates the airflow that curves downwards from the rear of the vehicle. [Figure 3] This is a top-down view of the vehicle body illustrating how the shape of the duct's inlet edge guides the airflow that has flowed along the side of the vehicle body into the duct. [Modes for carrying out the invention]

[0013] The rear structure of the vehicle body according to the present invention will be described in detail. The present invention relates to a rear body structure of a vehicle body that includes a luggage door located behind the rear end of the rear pillar, covering the upper surface of at least a portion of the trunk or luggage space.

[0014] Specifically, it is a rear structure of the vehicle body that has a certain length from the rear end of the rear pillar to the rear end of the vehicle body, and controls the airflow that flows along the side of the vehicle body and the airflow that flows along the top surface of the vehicle body, which merge behind the cabin, flow over the top surface of the luggage door, and then curve downward from the rear end of the vehicle body.

[0015] The rear body structure of the present invention is intended for vehicle body shapes such as notchback and fastback types, and does not target 1BOX or 2BOX type vehicle body shapes where the airflow along the sides of the vehicle body and the airflow along the top of the vehicle body collide at the rear of the vehicle body.

[0016] The notchback type described above has an appearance that clearly distinguishes the cabin from the trunk or luggage space, while the fastback type has a design where the rear window and luggage door appear to be connected, or where opening and closing the luggage door also opens and closes the rear window.

[0017] First, a vehicle body having a luggage door 2 that covers at least a part of the upper surface of a trunk or a luggage space behind the rear end of a rear pillar 1, which is the object of the present invention, will be described with respect to the air flow behind the vehicle body when it is affected by a crosswind.

[0018] When the vehicle body is affected by a crosswind during driving, it is greatly affected by the air flow flowing along the side surface of the vehicle body. Focusing on the air flow flowing along the side surface of this vehicle body, as shown in FIG. 1, the air flow flowing from the front to the rear on the upper side of the vehicle body side surface wraps around the upper surface of the luggage door 2 behind the rear pillar 1, that is, behind the cabin 4.

[0019] At this time, when the vehicle body is affected by a crosswind, the air flow flowing along the side surface of the vehicle body on the upwind side is pushed by the crosswind and greatly wraps around the upper surface of the luggage door 2. On the other hand, the air flow flowing along the side surface of the vehicle body on the downwind side is less affected by the crosswind, so it hardly wraps around the upper surface of the luggage door and flows almost straight along the side surface of the vehicle body. Therefore, a pressure difference occurs between the upwind side and the downwind side on the upper surface of the luggage door 2, and a large swirling vortex is formed on the downwind side.

[0020] Then, at the rear end of the vehicle body, the air flow flowing along the side surface of the vehicle body on the downwind side is卷入 into the above-mentioned swirling vortex, and as shown in FIG. 2, from the rear end of the luggage door 2 on the downwind side, that is, from the rear end of the vehicle body on the downwind side, it turns obliquely downward toward the center in the vehicle width direction, forming a strong negative pressure region behind the vehicle body on the downwind side.

[0021] The rear structure of the vehicle body of the present invention suppresses the strong negative pressure behind the vehicle body on the downwind side generated when affected by a crosswind and reduces air resistance.

[0022] The rear structure of the vehicle body of the present invention includes ducts 5 on the left and right sides of the vehicle body, in which an inlet 6 is formed at the lower part of the rear pillar 1 and an outlet 7 is formed on the rear surface of the vehicle body, and the air flow flowing along the side surface of the vehicle body is circulated from the lower part of the rear pillar 1 toward the rear surface of the vehicle body.

[0023] In this invention, "rear view" refers to the area where, in a top view, the angle between the tangent to the contour of the vehicle body and the axle is less than 45°.

[0024] As shown in Figure 3, the edge shape of the inlet 6 of the above-mentioned duct is such that the portion 61 that guides the airflow that has flowed from the outside of the vehicle body, i.e., the side of the vehicle body, into the duct is deflected towards the center in the vehicle width direction from front to rear, with the rear of the vehicle body being closer to the center in the vehicle width direction than the front of the vehicle body.

[0025] With this edge shape of the intake 6, the airflow that wraps around the top surface of the luggage door 2 at the rear of the cabin 4 flows approximately parallel to the edge 61 of the duct intake on the windward side, as shown in Figure 3, and passes just past the intake 6, making it difficult for the air to be guided into the duct 5. On the leeward side, it flows in a direction that intersects with the edge 61 of the duct intake and is guided into the duct 5.

[0026] Therefore, even if the direction of the crosswind acting on the vehicle changes, airflow is always introduced into the duct 5 on the leeward side, and the flow rate of the airflow inside the duct 5 changes depending on the strength of the crosswind acting on the vehicle.

[0027] The airflow that has passed through the duct 5 on the leeward side then passes through the duct 5, indicated by the dotted line in Figure 3, and is discharged from the outlet 7 on the rear of the vehicle body on the leeward side. This mitigates the negative pressure area created at the rear of the vehicle body on the leeward side due to crosswinds, thus reducing air resistance depending on the direction and strength of the crosswinds acting on the vehicle body.

[0028] The inlet 6 of the duct described above may be shaped to introduce airflow into the duct by providing a protrusion on the surface of the vehicle body, or it may be a NACA duct shape that takes in airflow without providing a protrusion on the surface of the vehicle body.

[0029] The position of the outlet 7 of the duct 5 described above is such that the airflow introduced from the left side of the vehicle body is discharged to the left side of the rear of the vehicle body, and the airflow introduced from the right side of the vehicle body is discharged to the right side of the rear of the vehicle body. Depending on the shape of the vehicle body, it is preferable that these outlets be located at the upper corners of the rear end of the vehicle body, as shown in Figure 2.

[0030] As described above, the strong negative pressure generated at the rear of the vehicle when subjected to a crosswind occurs because the airflow that flows along the leeward side of the vehicle curves diagonally downward from the rear end of the vehicle towards the center in the width direction.

[0031] Therefore, by positioning the duct outlet 7 at the upper corner of the rear end of the vehicle body, which is the starting point for this airflow to curve diagonally downward, the airflow curving diagonally downward and the airflow discharged from the duct collide, suppressing the diagonal downward curvature of the airflow, thus improving the effect of reducing air resistance.

[0032] It is preferable that the duct 5 described above is bent upward at the rear end of the vehicle, or bent outward in the vehicle width direction at the rear end of the vehicle.

[0033] Because the duct is bent upward at its rear end or bent outward in the width direction of the vehicle, the airflow discharged from the outlet 7 of the duct 5 collides at a large angle with the airflow that curves diagonally downward from the rear end of the vehicle body. As a result, the diagonal downward curvature of the airflow is further suppressed, and the effect of reducing air resistance can be further improved.

[0034] As described above, the rear structure of the vehicle body of the present invention allows the airflow introduced into the duct to switch between the left and right sides of the vehicle body depending on the direction and strength of the crosswind acting on the vehicle body, and the flow rate also changes. Therefore, the airflow discharged from the duct 5 can be passively adjusted without using actuators or the like, and air resistance can be reduced in response to crosswinds. [Explanation of Symbols]

[0035] 1. Rear pillar 2 Luggage Doors 3 Rear window 4. Roof (cabin) 5 ducts 6 Inlet 61 Edge that guides airflow on the outside of the vehicle body 7 Outlet

Claims

1. A rear structure of a vehicle body having a luggage door located behind the rear end of the rear pillar, which covers the upper surface of at least a portion of the trunk or luggage space, It is equipped with a duct that allows air to flow from the lower part of the rear pillar toward the rear of the vehicle body, The rear structure of the vehicle body is characterized in that the edge shape of the inlet of the above-mentioned duct is such that, on the outside of the vehicle body, the rear of the vehicle body is located in the center in the width direction of the vehicle body rather than the front of the vehicle body.

2. The rear structure of the vehicle body according to claim 1, characterized in that the duct is bent upward at the rear end of the vehicle.

3. The rear structure of a vehicle body according to claim 1 or 2, characterized in that the duct is curved outward in the vehicle width direction at the rear end of the vehicle.

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