JP2013052696A - Vehicle lower part structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle lower part structure that eliminates wind noise generated by travelling wind or airflow (wind) in travelling.SOLUTION: A frame member 10 having a hollow cavity and disposed at the rear side of a front wheel T, is provided in an under-floor portion 1c. A seal member S sealing an opening 10c communicating with the outside of the frame member 10 and the hollow cavity, and an undercoat A covering the seal member S, are provided in the under-floor portion 1c.

Description

  The present invention relates to a vehicle body lower structure, and more particularly, to a vehicle body lower structure in which wind noise is prevented from being generated in the vehicle lower part due to traveling wind flowing under the floor when the vehicle is traveling.

  Conventionally, when there is an uneven portion under the floor of the vehicle, when the vehicle travels, a traveling wind hits the uneven portion to generate a wind noise (see, for example, Patent Document 1).

  An automobile having a rain umbrella storage structure in an automobile disclosed in Patent Document 1 includes an opening made of a hole for discharging water droplets attached to the umbrella at a lower part of a floor, and a plate-like on-off valve that opens and closes the opening. And are provided. In the case of the automobile, if the opening is closed with an opening / closing valve, wind noise is not generated by the opening and the opening / closing valve during traveling.

Japanese Patent Laid-Open No. 9-277879 (paragraph 0012, FIG. 2)

  However, in the conventional automobile as described above, when the opening / closing valve is opened during traveling, the traveling wind hits the opening / closing valve to generate a wind noise, or the traveling wind enters the opening and the wind noise is generated. Occur. In particular, when traveling at high speed, the traveling wind that flows to the left and right of the front wheels merges into the turbulent flow behind the left and right front wheels, so the air resistance received by the opening and the on-off valve increases. For this reason, traveling wind easily enters the opened opening, and wind noise is generated by the principle of finger whistle.

  FIG. 8 is a diagram of a bottle showing the principle of finger whistle in which sound is generated by the flow of air flow, (a) is a schematic diagram showing a state where the depth of the cavity is shallow, and (b) is the depth of the cavity. It is a schematic diagram which shows a state in case the depth is deep.

  The opening under the floor of the automobile described in Patent Document 1 is similar to the principle of the whistle shown in FIGS. 8A and 8B from the openings 110 and 210 of the bottles 100 and 200 to the cavities 120 and 220. When an air current enters the inside, a sound is generated and becomes a wind noise.

  As shown in FIGS. 8A and 8B, for example, when the breath 300 (airflow) hits the right edge of the openings 110 and 210 from the left side of the bottles 100 and 200, the inside of the cavities 120 and 220 A breath 310 enters and a breath 320 exits outside the bottles 100, 200. At this time, in the bottles 100 and 200, the swirl of the breath 330 is generated in the hollow portions 120 and 220, and the air in the bottles 100 and 200 is vibrated to generate sound.

As shown in FIG. 8A, a high sound is generated when the bottle 100 has a large amount of water W1 and the depth H1 of the cavity 120 is shallow.
As shown in FIG. 8B, in the case of the bottle 200 with a small amount of water W2 and a deep depth H2 of the cavity 220, a low sound is generated.

Thus, when there are openings 110, 210 communicating with the cavities 120, 220 under the floor of the automobile, traveling wind flows into the cavities 120, 220 from the openings 110, 210 during traveling, The finger whistle principle works and sounds like a whistle.
That is, the opening part of the cylindrical structure corresponds to the opening parts 110 and 210 of the hollow parts 120 and 220 in FIGS. 8A and 8B under the floor of the automobile of the cited document 1, and traveling wind is generated during traveling. When hitting the openings 110 and 210, a sound (wind noise) is generated in the same manner as the finger whistle principle, and the cavity vibrates and propagates to the floor panel or the like, resulting in an unpleasant sound for passengers in the vehicle interior. There is a problem of being transmitted.

  As described above, an opening that communicates with the cavity is formed in a skeleton member under the floor of the automobile, a joint portion between the skeleton member and the skeleton member, a member such as a front under cover and a floor under cover. In this case, due to the principle of finger whistle, there is a problem that the member forming the cavity portion is vibrated and propagated by the traveling wind to generate abnormal noise.

  Therefore, the present invention was devised to solve the above-described problems, and provides a vehicle body lower structure that eliminates wind noise generated under the floor due to traveling wind and airflow (wind) while the vehicle is traveling. Let it be an issue.

  A vehicle body lower part structure according to the present invention is a vehicle body lower part structure provided under a floor of a vehicle with a skeleton member that is disposed behind a front wheel and has a hollow part formed in a hollow shape. A seal member that closes an opening that communicates with a portion and the outside of the skeleton member, and an undercoat that covers the seal member are provided.

According to such a configuration, the vehicle body lower structure blocks the opening under the floor of the vehicle with the sealing member, thereby preventing the traveling wind and airflow (wind) flowing under the floor of the vehicle from entering the opening. Can eliminate the generation of sound due to the phenomenon of finger whistle. As a result, the hollow portion vibrates and propagates the members such as the floor panel and the undercover by the traveling wind and airflow, and it is possible to eliminate the unpleasant wind noise transmitted to the occupant. Furthermore, it is possible to prevent foreign matters such as dust, muddy water, and rainwater from entering the cavity from the opening.
Further, since the periphery of the seal member is covered and protected by an undercoat, the periphery of the seal member attached to the skeleton member can be reinforced. Can be prevented from falling.

  The skeleton member includes a pair of left and right front side frames extending in the longitudinal direction of the vehicle body, and a pair of left and right side sills disposed outside the front side frame and extending in the vehicle longitudinal direction. An outrigger that connects the left and right front side frames and the left and right side sills, respectively, and the opening is a connecting portion between the left and right outriggers and the left and right front side frames or the left and right side sills. It is preferable to arrange | position.

  According to such a configuration, when the outrigger has, for example, a hat shape in cross section, the outrigger is coupled to the front side frame or the side sill by the respective welding flanges formed on the bottom surface and the side surface. For this reason, an opening (relief hole) on the press molding is inevitably formed in each joint portion. Since the opening is not a simple round hole but an irregular shape, even if it is difficult to close the opening with a blind cover, the opening is closed by the seal member, so that the opening can be easily closed.

  Moreover, it is preferable that the said sealing member is formed in the polygonal shape containing a rectangle.

  According to such a configuration, the rectangular sealing member can be easily attached by attaching a polygonal diagonal line along the ridgeline, so that the workability of attaching the sealing member to the vehicle body can be improved.

  The undercoat is preferably formed larger than the outer shape of the seal member.

  According to this configuration, the undercoat is formed larger than the outer shape of the seal member, so that the seal member is covered with the undercoat, and the periphery of the seal member is rolled up and peeled off or dropped off. It can suppress and can improve the durability of a seal member.

  The seal member and the undercoat are preferably made of a thermosetting material.

  According to such a configuration, the seal member and the undercoat are made of a thermosetting material, so that the work of attaching the seal member is easy, and at the same time, the seal member and the undercoat are thermally cured in the painting process and integrated with the floor of the vehicle body. You can also.

  Moreover, it is preferable that a diffuser for directing an airflow flowing from the front of the vehicle toward the rear of the vehicle toward the outside of the vehicle body is provided on the lower surfaces of the left and right outriggers.

  According to such a configuration, the outrigger is provided with a diffuser that directs an airflow that flows from the front of the vehicle toward the rear of the vehicle toward the outside of the vehicle body on the lower surface thereof, so that the traveling wind flows toward the left and right outer sides of the vehicle. Can do. For this reason, if the diffuser is arranged in front of the opening, it prevents the running wind from flowing into the opening and suppresses the generation of unpleasant sounds such as a finger whistle and wind noise. can do.

  INDUSTRIAL APPLICABILITY The present invention can provide a vehicle body lower structure that eliminates wind noise generated under the floor due to traveling wind or airflow (wind) while the vehicle is traveling.

It is a principal part schematic bottom view of the vehicle body which shows the vehicle body lower part structure concerning embodiment of this invention. It is the XX line end view of FIG. FIG. 2 is an end view taken along line YY in FIG. 1. It is a principal part schematic disassembled perspective view which shows the vehicle body lower part structure concerning embodiment of this invention. It is a figure which shows the vehicle body lower part structure concerning embodiment of this invention, and is a principal part schematic perspective view of the state which removed the seal member and the undercoat. It is a principal part general | schematic expanded bottom view which shows the vehicle body lower part structure concerning embodiment of this invention. FIG. 3 is an end view taken along line ZZ in FIG. 2. It is a figure of the bottle which shows the principle of the finger whistle which a sound is generated by the flow of an air current, (a) is a schematic diagram which shows the state when the depth of a cavity is shallow, (b) is the case where the depth of a cavity is deep It is a schematic diagram which shows this state.

With reference to FIGS. 1-7, the vehicle body lower part structure which concerns on embodiment of this invention is demonstrated.
It is assumed that the traveling direction of the vehicle C is “front”, the backward direction is “rear”, “vertically upward is“ up ”, vertically downward is“ down ”, and the vehicle width direction is“ left ”and“ right ”. .

≪Vehicle configuration≫
First, before describing the vehicle body lower part structure according to the embodiment of the present invention, a vehicle C to which the present invention is applied will be described.
As shown in FIG. 1, the vehicle C is a motor vehicle having a motor room in a vehicle body front portion 1 a and a vehicle room (guest room) disposed in the motor room with a partition wall (not shown) interposed therebetween. For example, FF (front engine / front drive), FR (front engine / rear drive), four-wheel drive passenger car, and the like.
As long as the vehicle C has an opening 10c to be described later in the underfloor 1c, the type and type of the automobile are not particularly limited. Hereinafter, the present invention will be described by taking as an example the case of a passenger car having a motor room in the vehicle body front portion 1a.

≪Body structure≫
As shown in FIG. 1, the vehicle body 1 is for forming the entire vehicle C. For example, a skeleton member 10 that forms various metal vehicle body frames such as a front side frame 11, and the like (not shown) It mainly includes a metal panel member 20 such as a bonnet or a fender panel, and a front bumper B made of resin or metal.

  A front bumper B, a front wheel T, a skeleton member 10, a panel member 20, a diffuser 3, a seal member S, an undercoat A and the like, which will be described later, are provided on the vehicle body lower portion 1b of the vehicle body front portion 1a. It is installed symmetrically. Since the vehicle body front portion 1a is substantially bilaterally symmetric, the left side of the vehicle body 1 will be mainly described below, and the description of the right side of the vehicle body 1 will be omitted as appropriate.

≪Configuration of front bumper≫
As shown in FIG. 1, the front bumper B extends in the vehicle width direction at the front end of the vehicle body front portion 1a. The front bumper B is fixed to a bumper beam (not shown) extending in the vehicle width direction along the front bumper B. The bumper beam is a vehicle body frame made of square tubular steel material, and is connected to the front end of the front side frame 11 via a bumper beam extension (not shown).

≪Configuration of front wheel≫
The front wheels T are arranged on the left and right sides of the front bumper B, and are covered with a front wheel house 21 described later through a space.

≪Structure of skeleton member≫
As shown in FIG. 2, the skeleton member 10 is a member that forms the skeleton of the vehicle C, and is a metal member having a hollow portion 10a formed in a hollow shape. As the skeleton member 10 provided in the vehicle body lower portion 1b of the vehicle body front portion 1a, a front side frame 11, a side sill 12, an outrigger 13, a cross member (not shown), a tunnel frame (not shown), a floor frame 14, and a front pillar, which will be described later. There are 15 mags.

<Configuration of front side frame>
As shown in FIG. 1, the front side frame 11 is a pair of left and right frame members that extend from the rear of the bumper beam (not shown) toward the rear of the vehicle body in the vehicle body lower portion 1b of the vehicle body front portion 1a. A floor frame 14 is continuously joined to the rear end portion of the front side frame 11, and an outrigger 13 and a cross member (not shown) are installed at the rear portion.

  As shown in FIG. 2, the front side frame 11 has a substantially U-shaped front side frame main body 11a as viewed in a longitudinal section with the upper surface opened, and an opening portion of the front side frame main body 11a through a front under panel 23. And a reinforcing edge 11b joined by welding means so as to be closed. As described above, the front side frame 11 is formed in a substantially Japanese character when the front side frame main body 11a, the front under panel 23, and the reinforcing edge 11b are viewed in cross section. That is, since the front side frame 11 is formed so that the closed cross section is doubled, it has high rigidity.

The front side frame main body 11a is made of a grooved steel with a hat-shaped hook when viewed in cross section, and extends slightly bent toward the front-rear direction of the vehicle body 1 (see FIG. 1).
The reinforcing edge 11b is made of grooved steel with a hat shape in cross section formed so as to match and close the opening of the front side frame body 11a, and is formed lower than the height of the front side frame body 11a. Has been.

<Configuration of side sill>
As shown in FIG. 1, the side sill 12 is disposed at the left and right ends outside the front side frame 11 in the vehicle width direction, and extends from the rear of the front wheel house 21 (front wheel T) toward the rear of the vehicle body. It is a pair of left and right frame members that support the left and right ends of the floor panel 25.
As shown in FIG. 2, the side sill 12 is disposed between the side sill inner 121 disposed on the center side of the vehicle body, the side sill outer 122 disposed on the outer side of the vehicle body, and between the side sill outer 122 and the side sill inner 121. This is a hollow frame member formed by joining a side sill flange 123 and a jack-up stiffener 124 and a side sill reinforcing bracket 125 made of a metal plate member.

As shown in FIG. 2, the side sill inner 121 is composed of a high-strength steel plate in which the upper joint portion 12a at the upper end portion is joined to the lower end portion of the front pillar 15 and the lower end portion is joined to the outer end portion of the floor panel 25, For example, it is bent and formed in a shape that swells to the vehicle compartment side in a longitudinal section.
The side sill outer 122 is made of a high-strength steel plate disposed so as to cover the entire side sill 12 from the outside of the vehicle, and a joint 10d at the lower end is joined to the fender 22, the front under panel 23, and the outrigger 13 by welding means.

The side sill fuchisna 123 is made of a high-strength steel plate that is hat-shaped in the vertical direction when viewed in a longitudinal section so as to form a hollow space with the side sill inner 121. The side sill fist fastener 123 has a lower end joined to the connecting portion 10d, and an upper joined portion 12a at the upper end joined to the front pillar 15 and the jack-up stiffener 124.
The jack-up stiffener 124 is a reinforcing plate member that is interposed between the side sill inner 121 and the side sill outer 122 and is arranged so as to bisect the closed cross-section in the left and right directions, and has an upper end portion at the upper joint portion 12a. The lower end portion is joined to the coupling portion 10d.
The side sill reinforcing bracket 125 is a metal reinforcing plate member provided at the upper part in the side sill inner 121.

<Outrigger configuration>
As shown in FIG. 2, the outrigger 13 is a frame member that is installed between the front side frame 11 and the side sill 12 and is connected to each by welding means. As shown in FIG. 3, the outrigger 13 is made of a steel plate that is press-formed into a substantially hat shape when viewed in a longitudinal section, and an airflow (running wind) that flows from the front of the vehicle toward the rear of the vehicle on the lower surface 13 a of the outrigger 13. A diffuser 3 is provided for directing the vehicle in the vehicle body outward direction. A front welding flange 13f that joins to the dashboard lower panel 24 is formed at the front end of the outrigger 13 in the front-rear direction, and rear welding that is joined to the dashboard lower panel 24 and the floor panel 25 at the rear end. A flange 13g is formed.

  As shown in FIG. 4, welding flanges 13 d and 13 e are formed on the side and upper surfaces of the outer side of the outrigger 13 in the vehicle width direction and welded flanges 13 d and 13 e are joined to the side and upper ends of the side sill inner 121 of the side sill 12 by welding means. Has been.

  As shown in FIG. 4, an opening 10 c that communicates from the cavity 10 a formed in the outrigger 13 to the atmosphere outside the outrigger 13 (the skeleton member 10) is formed at the connection portion between the outrigger 13 and the side sill 12. ing.

<Configuration of opening>
The opening 10c of the skeletal member 10 is a so-called escape hole, and is disposed, for example, at a joint 10d between the outrigger 13 and the side sill 12. A similar opening (not shown) is also formed in a coupling portion (not shown) between the outrigger 13 and the front side frame 11.
That is, the opening 10c is formed when the skeleton member 10 extending in the longitudinal direction of the vehicle body and the skeleton member 10 extending in the width direction of the vehicle body 1 are connected. The opening 10c (escape hole) is always formed when the welding flanges 13d and 13e are press-molded on the lower surface 13a and the side surface of the outrigger 13.

<Configuration of cross member, tunnel frame and floor frame>
The cross member (not shown) is a cylindrical frame member disposed substantially in the left-right direction with respect to the vehicle body 1, and is installed on the rear portions of the left and right front side frames 2, 2.
The tunnel frame (not shown) is composed of a pair of left and right metal hollow members that extend in the vehicle front-rear direction at the left and right ends of the tunnel portion installed at the center of the floor portion of the passenger compartment. The tunnel frame (not shown) is a frame member that is joined to the floor frame 14, the outrigger 13, and the dashboard lower panel 24 installed at the front end thereof, and holds the vehicle body center side of the floor panel 25. It is arranged under the floor 1c.
The front end of the floor frame 14 is connected to the rear part of the front side frame 2, the vehicle body center side is connected to a tunnel frame (not shown), and the vehicle body outer side is welded to the side surfaces of the left and right side sills 12 on the passenger compartment side. .

≪Configuration of panel members≫
As shown in FIG. 1, the panel member 20 is made of a metal plate material such as a steel plate or an aluminum alloy, or a synthetic resin plate material. Examples of the panel member 20 provided in the vehicle body lower portion 1b of the vehicle body front portion 1a include a front wheel house 21, a fender 22, a front under panel 23, a dashboard lower panel 24, a floor panel 25 and the like which will be described later.

<Configuration of front wheel house>
The front wheel house 21 is a member disposed so as to cover the front wheel T through a space, and is disposed on the outer side surface of the front side frame 2 in the vehicle width direction. On the lower surface of the front wheel house 21, a resin inner fender 21a, a resin wheel arch protector 21b, and the like are provided.

<Fender configuration>
The fender 22 shown in FIG. 2 is a panel member that extends downward from the left and right sides of the bonnet disposed on the upper surface of a motor room (not shown), and a lower end portion 22a of the fender 22 together with a front pillar (not shown) It is connected to the front end of the side sill 12.

<Configuration of front under panel>
As shown in FIG. 1, the front under panel 23 is a steel plate disposed below the motor room in the vehicle body lower portion 1 b of the vehicle body front portion 1 a, and from the rear portion of the front bumper B to the tip of the floor under panel 26. It is arranged over.

<Dashboard lower panel configuration>
The dashboard lower panel 24 is a member that forms a lower part of a partition wall that partitions the motor room and the vehicle compartment, and is made of, for example, a steel plate.

<Configuration of floor panel and floor under panel>
The floor panel 25 is a plate member that forms the floor surface of the passenger compartment (guest room), and is made of, for example, a steel plate that is disposed from the left and right side sills 12 to a tunnel frame (not shown) that is disposed in the center of the vehicle body. .
The floor under panel 26 is a floor under cover disposed below the floor panel 25. Note that the left and right front end portions of the floor under panel 26 near the opening 10c are cut out to dispose the jack when the vehicle body 1 is jacked up with the jack.

≪Configuration of diffuser≫
As shown in FIGS. 4 and 6, the diffuser 3 is an aerodynamic component provided in the lower part 1b of the vehicle body, and is inclined so that the outer side in the vehicle width direction is slightly on the rear side of the vehicle body at the central part of the lower surface 13a of the outrigger 13. Are arranged. The diffuser 3 is disposed on the front side of the vehicle body relative to the opening 10c. The diffuser 3 receives the traveling wind flowing from the front of the vehicle body against the diffuser 3 toward the rear of the vehicle body in the outward direction in the vehicle width direction. In addition, it is difficult to generate a vortex (turbulent flow) of the traveling wind and the traveling wind (airflow) hardly flows in the direction toward the opening 10c. The diffuser 3 includes a flat plate portion 31 in which three through holes 3a into which fixing tools N such as fixing clips and screws are inserted, and a rectifying plate that hangs downward from the flat flat plate portion 31. It consists of the metal plate member which formed the part 32 integrally. The diffuser 3 is fixed to the lower surface 13a of the outrigger 13 with a washer 33 interposed by a screw N inserted into the through hole 3a.

The flat plate portion 31 is a plate-like portion that is formed from the lower end portion of the rectifying plate portion 32 toward the rear of the vehicle body and is disposed in contact with the lower surface 13 a of the outrigger 13.
The rectifying plate portion 32 is an upright plate portion formed in an arc shape when viewed from above (see FIG. 1) and a rectangular shape when viewed from the back, so that the traveling wind that flows from the front of the vehicle body 1c toward the rear of the vehicle body hits the floor 1c. In addition, it is arranged so as to protrude downward from the underfloor 1c.

≪Configuration of seal member≫
As shown in FIGS. 4 and 6, the seal member S closes the opening 10 c communicating with the cavity 10 a (see FIG. 2) of the underfloor 1 c and the outside 10 b of the skeleton member 10, It is a blocking member (patch) for preventing liquids such as rainwater and foreign matter such as gravel, dust, and small dust from entering the cavity 10a. The seal member S is formed in a polygonal shape including a rectangle by, for example, a thermosetting material. The seal member S is made of, for example, a tape-like thermosetting sealer, and is made of a single-sided adhesive type having a good coating appearance, excellent sealing properties, and rigidity.
As shown in FIGS. 6 and 7, the seal member S is configured so that the diagonal line Sa of the seal member S coincides with the ridge line portion 13 c of the outrigger 13 in order to close the opening 10 c, and Affixed across the rear side surface 13 b and the side sill inner 121.

<Configuration of undercoat>
As shown in FIGS. 6 and 7, the undercoat A is a reinforcing member that covers the sealing member S and prevents peeling and dropping, and is made of a thermosetting resin formed larger than the outer shape of the sealing member S. It is a coating material made of material. For example, the undercoat A is applied to the coupling portion 10d between the outrigger 13 and the side sill 12 so as to cover the entire seal member S. In particular, the undercoat A is provided so that the undercoat A does not peel from the vehicle body 1 by coating and covering the outer peripheral edge of the sealing member S and the peripheral portions of the undercoat A of the outrigger 13 and the side sill 12. It has been. The undercoat A is made of a material containing, for example, an acrylic resin or a wetane resin as a main component and a filler, a plasticizer, an additive, or the like.
The undercoat A, when applied to the vehicle body 1, also has effects such as prevention of paint peeling, wear prevention, chipping prevention, rust prevention, soundproofing and vibration prevention.

≪Operation of underbody structure≫
Next, the operation of the vehicle body lower part structure according to the embodiment of the present invention will be described with reference mainly to FIGS. First, an operation for closing the opening 10c of the skeleton member 10 will be described.

  When closing the opening 10c, as shown in FIG. 4, the diagonal line Sa of the rectangular seal member S is placed on the ridge 13c of the outrigger 13, and the opening 10c is covered with the seal member S and closed. In this case, the sealing member S closes the opening 10c so that the diagonal line Sa of the sealing member S is aligned with the ridge line portion 13c of the outrigger 13, and the sealing member S has flexibility. The attachment of the seal member S is easy.

Next, as shown in FIG. 6, the undercoat A is applied to the sealing member S so as to cover the sealing member S, and to the outrigger 13 and the side sill 12 around the sealing member S. After painting, it is cured by a drying process. As described above, the seal member S is covered with the undercoat A, so that the anti-drop durability is improved.
Thereby, the attachment of the seal member S and the undercoat A is completed.

Next, the case where the vehicle C having the vehicle body lower part 1b configured as described above travels in the vehicle front direction will be described.
As shown in FIG. 1, when the vehicle C travels forward, traveling wind (arrows a, b, c) flows from the front of the vehicle body toward the rear of the vehicle body on the entire outer periphery of the vehicle C. At that time, traveling wind (arrows a, b, c) also flows under the floor 1c of the vehicle body 1 from the front of the vehicle body to the rear of the vehicle body.
The traveling wind (arrow a) flowing under the floor 1c close to the center of the vehicle body flows straight under the front bumper B, under the front under panel 23, and under the floor under panel 26 behind it.

  In the underfloor 1c near the vehicle body center of the front wheel T of the vehicle body front portion 1a, traveling wind (arrow b) flows from the left and right ends of the front bumper B through the vehicle body center side of the front wheel T toward the vehicle body rear. When the traveling wind (arrow b) passes by the side of the front wheel T, it strikes the rectifying plate portion 32 of the diffuser 3 and is directed in the vehicle body outward direction (arrow f direction). For this reason, turbulent airflow is generated behind the front wheel T by the traveling wind (arrow b) and the traveling wind (arrow c) flowing outside the front wheel T from the front portion 1a of the vehicle body toward the rear of the vehicle body. It can suppress that air resistance becomes excessive.

As shown in FIG. 5, an opening 10 c is formed in the joint portion 10 d of the outrigger 13 and the side sill 12 on the rear side outside the vehicle body of the diffuser 3, but as shown in FIG. Since it is blocked by the seal member S and the undercoat A, the wind noise caused by the traveling wind is not generated by the above-described finger whistle principle.
As a result, the seal member S conventionally has a driving wind (airflow) invading into the opening 10c, so that the outrigger 13 vibrates with the driving wind and propagates to the floor panel 25 due to the finger whistle principle. It can be solved that it was heard as an unpleasant wind noise.
Further, since the peripheral portion and the entire periphery of the seal member S are firmly fixed to the vehicle body 1 by the undercoat A, the seal member S will not be peeled off even when traveling wind, rainwater, gravel or the like comes into contact therewith.

  In addition, since the opening 10c is closed by the seal member S and the undercoat A, foreign matter such as the traveling wind (gas), liquid such as rain water, gravel, dust, and small dust may be hollow from the opening 10c. Intrusion into 10a can be prevented, and rust and the like can be prevented from occurring.

[Modification]
The present invention is not limited to the above-described embodiment, and various modifications and changes can be made within the scope of the technical idea. The present invention extends to these modifications and changes. Of course.

  For example, in the above-described embodiment, as an example of the skeleton member 10 in which the opening 10c is formed, a so-called escape hole formed in the joint portion 10d of the outrigger 13 and the side sill 12 has been described as an example. The skeleton member 10 disposed on the vehicle body lower portion 1 b may be used, and is not limited to the joint portion 10 d between the outrigger 13 and the side sill 12.

  The opening 10 c may be, for example, a through hole, a hole, a recess, a gap, or the like that is formed in the skeleton member 10 of the underfloor 1 c of the vehicle body 1 and communicates with a hollow portion in the skeleton member 10.

  Moreover, the coupling | bond part 10d of the frame member 10 should just be a frame member in which opening (escape) is formed. For example, the connecting portion 10d is connected so as to be laid over a hollow frame member extending in the longitudinal direction of the vehicle body such as the front side frame 11 and the side sill 12, and a hollow frame member extending in the longitudinal direction of the vehicle body. It may be a connecting portion of the outrigger 13 with a hollow frame member extending in the vehicle width direction, such as a vehicle body center side end portion, a cross member, a floor frame 14 or the like.

Moreover, the front side frame 11, the side sill 12, and the other skeleton members 10 only have to have the hollow portion 10a, and the shape, material, and the like are not particularly limited. That is, the skeleton member 10 may be a tubular member having another shape such as a rectangular tubular frame or a cylindrical shape.
Moreover, those skeleton members 10 should just be a material with high rigidity, and may consist of light alloys, such as an aluminum alloy, and resin materials.

DESCRIPTION OF SYMBOLS 1 Vehicle body 1c Underfloor 3 Diffuser 10 Frame member 10a Cavity part 10b External part 10c Opening 10d Joint part 11 Front side frame 12 Side sill 13 Outrigger 13a Lower surface 20 Panel member A Undercoat C Vehicle S Seal member T Front wheel

Claims (6)

A vehicle body lower structure having a skeleton member disposed behind the front wheel and having a hollow cavity formed under the floor of the vehicle,
Under the floor, a seal member that closes an opening communicating with the cavity and the outside of the skeleton member;
An undercoat covering the sealing member;
The vehicle body lower structure characterized by being provided. The skeleton member includes a pair of left and right front side frames extending in the longitudinal direction of the vehicle body,
A pair of left and right side sills arranged outside the front side frame in the vehicle width direction and extending in the vehicle body longitudinal direction;
Outriggers that connect the left and right front side frames and the left and right side sills, respectively,
The vehicle body lower structure according to claim 1, wherein the opening is disposed at a coupling portion between the left and right outriggers and the left and right front side frames or the left and right side sills.   The vehicle body lower part structure according to claim 1 or 2, wherein the seal member is formed in a polygonal shape including a rectangle.   The underbody structure according to any one of claims 1 to 3, wherein the undercoat is formed to be larger than an outer shape of the seal member.   The vehicle body lower structure according to any one of claims 1 to 4, wherein the seal member and the undercoat are made of a thermosetting material.   The underbody structure according to claim 2, wherein a diffuser for directing an airflow flowing from the front of the vehicle toward the rear of the vehicle toward the outside of the vehicle is provided on the lower surfaces of the left and right outriggers.

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