JP2017039354A - Flow straightening structure for lower part of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow straightening structure for a lower part of a vehicle, which aims at reducing air resistance while securing a minimum ground clearance using an undercover supported on the vehicle body side.SOLUTION: A flow straightening structure for a lower part of a vehicle comprises: a front side cover part 46 for covering, from below, a front part with respect to a spring seat 30 of a rear suspension; a rear side cover part 48 for covering a rear under floor part with respect to the spring seat 30; and an opening part 49 formed below the spring seat 30 without being covered with the undercover. In the front side cover part 46, a lower surface is set higher than a lowest position α of the spring seat 30, and a wind separation part 50 is formed downwardly curved at a rear end of the front side cover part 46 so as to guide a wind blowing below the floor not to let it flow into the opening part 49. The rear side cover part 48 is arranged at a position spaced a predetermined distance apart from the opening part toward a rear side with respect to the wind separation part 50, and includes a salient lower surface 48b on the lower surface side of the lowest part 48a formed at a position substantially equal to or higher than the wind separation part 50.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a lower rectification structure for an automobile in which a vehicle floor surface is covered with an undercover.

In general, an undercover is used to reduce aerodynamic resistance under the floor of an automobile.
The rear suspension of the torsion beam axle type and semi-trailing arm type that suspends the rear wheels requires a wide swinging space in the vertical direction. Backward negative pressure was generated with respect to the auxiliary equipment, which increased aerodynamic resistance.

This point will be further described in detail with reference to the drawings.
FIG. 11 is a side view showing a lower rectification structure of a conventional automobile. In FIG. 11, a rear seat pan 82 and a recessed step are formed at the rear portion of the floor panel 80 via a kick-up portion 81. A rear floor 84 having a luggage compartment recess 83 is integrally formed rearward, and a rear end panel 85 extending in the vertical direction is vertically fixed to a rear end portion of the rear floor 84.

  A cross member 86 extending in the vehicle width direction is provided between the rear surface portion of the kick-up portion 81 and the lower surface of the front end portion of the rear seat pan 82, and the upper and lower portions of the rear end portion of the rear seat pan 82 are disposed in the vehicle width direction. A cross member upper 87 and a cross member lower 88 are provided, a rear cross member 89 extending in the vehicle width direction is provided below the front of the cargo compartment recess 83, and a vehicle width is provided on the front surface of the upper end of the rear end panel 85. A rear end member 90 extending in the direction is provided, and the rigidity of the lower vehicle body structure is improved by these members (elements 86 to 90) extending in the vehicle width direction.

  A fuel tank 92 is attached to the lower portion of the rear seat pan 82 using a tank band 91, and a silencer 93 is disposed below the cargo compartment recess 83, and a lower portion 93a of the silencer 93 is formed in a flat shape. It is formed to have a rectifying structure.

  A rear end under cover 95 that is integral with or separate from the rear bumper 94 is provided, while a torsion beam axle type rear suspension 96 as an example of a rear suspension is provided. The rear suspension 96 includes a torsion beam 97 that connects a pair of left and right trailing arms (not shown) in the vehicle width direction, and a spring seat 98 (specifically, a spring lower seat).

  An under cover 99 that covers the vehicle floor from below is provided, and the under cover 99 covers up to the portion immediately before the torsion beam 97 described above.

  As shown in FIG. 11, since the recess 100 is formed between the rear end portion of the fuel tank 92 and the front end portion of the silencer 93, the underfloor flowing on the lower surface of the under cover 99. The wind e8 is drawn into the recess 100, the underfloor wind e8 hits the front surface of the silencer 93, and a positive pressure (force that pushes the vehicle rearward) is generated on the front surface of the silencer 93.

Further, the underfloor wind e8 is peeled off at the rear end of the under cover 99, and negative pressure (force for pulling the vehicle rearward) is generated on the rear end surface of the fuel tank 92. Further, the underfloor wind e8 strikes the front surface of the spring seat 98 located in the above-described recess 100 between the fuel tank 92 and the silencer 93, thereby generating a positive pressure (force that pushes the vehicle rearward). A negative pressure (force that pulls the vehicle rearward) is generated on the rear surface of the spring seat 98.
The aerodynamic resistance increases due to the generation of each of these positive pressures and negative pressures.

  Therefore, in order to reduce the aerodynamic resistance, it is conceivable to cover the entire vehicle floor surface with the under cover including the lower part of the recess 100 shown in FIG. 11. However, the torsion beam 97 and the spring seat 98 of the rear suspension 96 are: Since it moves up and down in accordance with the behavior of the vehicle, an under cover is provided at a position where it does not interfere with the rear suspension 96, and it is difficult to ensure a sufficient minimum ground clearance.

  On the other hand, it is conceivable to attach an under cover to the movable part on the rear suspension 96 side, but in this case, vibration that is not damped by the damper is transmitted to the under cover as it is, so that the under cover requires high durability. Will be.

  By the way, in Patent Document 1, in a suspension cover structure for a vehicle, a floor cover provided on the vehicle and covering the lower surface of the vehicle body, a suspension cover provided adjacent to the rear and covering the suspension from below, and adjacent to the rear thereof. And a rear cover adjacent to the front of the rear bumper of the vehicle, wherein the suspension cover includes a pair of left and right trailing arm covers provided on each of the trailing arms, and an axle cover provided on the axle beam. In addition, there is disclosed a configuration in which a floor cover, a suspension cover, and a rear cover are provided on substantially the same plane on the substantially entire lower surface of the vehicle body.

However, the conventional structure disclosed in Patent Document 1 has the following problems.
That is, when the trailing arm cover that covers the trailing arm from below is displaced downward with respect to the floor cover due to the behavior of the vehicle, the floor arm winds against the trailing arm cover and a positive pressure is generated.

  This positive pressure is generated in a direction perpendicular to the surface of the trailing arm cover. This positive pressure has an up-down direction component and a front-rear direction component. It becomes a factor of resistance increase.

  Further, what is disclosed in Patent Document 1 is a rigid axle system, and in order to apply the axle cover of Patent Document 1 to a structure including a rear suspension of a torsion beam axle type, the axle cover is used as a torsion beam. If the torsion beam is provided, a load is applied to the torsion beam, and the rigidity distribution is lost. Therefore, the torsion beam axle type rear suspension cannot be used for the lower rectification structure of an automobile.

Furthermore, Patent Document 2 discloses a configuration in which a torsion beam is covered directly from below with an under cover (see the same publication, FIG. 3).
In the case of this configuration, when ice adhering to the torsion beam freezes, especially when an ice column is formed, the ice column may interfere with the undercover.

  Further, in Patent Document 2, an opening is formed in a portion corresponding to the torsion beam, a front under cover that covers the vehicle floor surface from below is extended rearward to the front end of the opening, and the vehicle rearward from the rear end of the opening. In addition, there is also disclosed a structure in which a floor under cover extending in the direction is provided, and two inclined portions extending in front and having different inclination angles are connected to the floor under cover (see the same publication, FIG. 2).

  However, in this structure, the underfloor air flowing through the lower surface of the front undercover is drawn into the opening, and the underfloor wind strikes the inclined portion, thereby generating a positive pressure in the inclined portion. This positive pressure is generated in a direction perpendicular to the surface of the inclined portion, and this positive pressure has an up-down direction component and a front-rear direction component, and this front-rear direction component acts as a force pushing the vehicle backward, increasing aerodynamic resistance. It becomes a factor of.

JP 2005-53321 A JP 2015-16835 A

  Accordingly, an object of the present invention is to provide a lower rectifying structure for an automobile that can reduce aerodynamic resistance while ensuring a minimum ground clearance by an undercover supported on the vehicle body side.

  A lower rectification structure for an automobile according to the present invention is a lower rectification structure for an automobile in which a vehicle floor surface is covered with an undercover, and a spring seat front side cover portion that covers a front portion from below below a spring seat of a rear suspension; A spring seat rear cover that covers the under floor behind the spring seat, and an opening that is formed below the spring seat and is not covered by the under cover, the lower surface of the spring seat front cover being the spring seat An underfloor wind peeling portion bent downward is formed at the rear end of the front cover portion of the spring seat so as to guide the underfloor air downward so as not to flow into the opening. The seat rear cover portion is spaced rearward from the peeling portion by a predetermined distance behind the opening, and Is what the lower surface of the convex downward with the bottom substantially equal or more positions formed height relative to the release unit.

According to the above configuration, the underfloor air flowing on the lower surface of the front cover part of the spring cover of the under cover is peeled off by the peeling part, and the underfloor wind after peeling is reattached to the lowermost part of the rear cover part of the spring seat, The underfloor wind after adhering can flow to the rear of the vehicle along the lower surface of the spring seat rear cover portion.
In addition, since the opening is provided below the spring seat, it is not necessary to cover the lower part of the spring seat that moves up and down in accordance with the behavior of the vehicle with an under cover, while ensuring the minimum ground clearance, the front cover portion of the spring seat The upper air and the underfloor air flowing through the lower surface of the front seat portion of the spring seat can be smoothly flowed rearward, and aerodynamic resistance can be reduced.

In one embodiment of the present invention, the lower surface of the spring seat is formed so as to incline forward at the time of steady state, and the portion of the front side of the vehicle from the lowermost part of the rear cover portion of the spring seat is located at the steady state. The spring seat is configured to form an inclined surface that is substantially continuous with the lower surface of the spring seat and the front in the vehicle longitudinal direction.
The above-mentioned steady state means a time when the vehicle is traveling at a constant speed on a flat ground in a range from a state in which only one driver gets on to a maximum loading capacity (or half of the maximum loading capacity).

  According to the above configuration, since the lower surface of the spring seat that is inclined forward and the inclined surface of the rear cover portion of the spring seat is substantially continuous to the front, air above the front cover portion of the spring seat is smoothly supplied. Therefore, the turbulence of the underfloor wind can be suppressed.

  In one embodiment of the present invention, the rear suspension includes a pair of left and right trailing arms, the spring seat provided at the rear of the pair of left and right trailing arms, and a position above the spring seat and in front of the vehicle. And a torsion beam erected in the vehicle width direction between the pair of left and right trailing arms at the position, and the spring seat front side cover portion covers the torsion beam from below.

  According to the above configuration, since the torsion beam is covered by the spring seat front cover portion, it is possible to prevent the underfloor wind flowing on the lower surface of the spring seat front cover portion from colliding with the torsion beam.

  In one embodiment of the present invention, the peeling portion is formed such that the underfloor wind is reattached behind the lowermost portion of the spring seat rear side cover portion during traveling at a speed of 30 km / h or more. Is.

  According to the above configuration, the underfloor wind is reattached behind the lowermost part of the rear cover portion of the spring seat by the peeling portion during traveling at a speed of 30 km / h or more. It is possible to smoothly flow toward the rear of the vehicle along the lower surface of the rear cover portion.

  According to the present invention, there is an effect that the aerodynamic resistance can be reduced while the minimum ground clearance is secured by the under cover supported on the vehicle body side.

The bottom view which shows the lower rectification | straightening structure of the motor vehicle of this invention 1 is a cross-sectional view taken along the line AA in FIG. 1 is a cross-sectional view of the main part along the line BB in FIG. 1 is a cross-sectional view of the main part along the line CC in FIG. DD sectional view taken along line D-D in FIG. Bottom view of center rear under cover Bottom view of rear center under cover Partial enlarged view of FIG. (A) is an exploded view of the fastener mounting portion of FIG. 8, (b) is a cross-sectional view when the fastener is completely mounted. Sectional view showing related structure of rear center under cover, insulator and exhaust pipe Side view of a conventional automobile lower rectification structure

  A spring seat for the rear suspension in the lower rectification structure of an automobile with the vehicle floor covered with an undercover for the purpose of reducing the aerodynamic resistance while ensuring the minimum ground clearance by the undercover supported on the vehicle body side A spring seat front side cover portion that covers the front part from below, a spring seat rear side cover portion that covers the floor below the spring seat, and an opening that is formed below the spring seat and is not covered by the under cover. The lower end of the spring seat front cover portion is set to be higher than the lowest position of the spring seat, and the rear end of the spring seat front cover portion for guiding the underfloor air downward so as not to flow into the opening. A peel-off part of the underfloor wind bent downward is formed, and the spring seat rear cover part is Realized by a configuration in which a convex lower surface is formed at a position below the opening by a predetermined distance behind the opening, and having a lowermost portion at a height approximately equal to or higher than the peeling portion. did.

An embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a bottom view showing the lower rectification structure, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line B, FIG. 4 is a cross-sectional view taken along the line C-C in FIG. 1, FIG. 5 is a cross-sectional view taken along the line D-D in FIG. FIG. 7 is a bottom view of the rear center under cover, and FIG. 7 is a bottom view of the center rear side under cover.

Prior to the description of the lower rectifying structure, the lower body structure of an automobile will be described first.
2 and 3, a rear floor 5 having a rear seat pan 3 and a luggage compartment recess 4 formed in a recessed shape at the rear of the floor panel 1 via a kick-up portion 2 rising upward. Specifically, a rear floor panel) is integrally or integrally formed rearward, and a rear end panel 6 extending in the vertical direction is vertically fixed to a rear end portion of the rear floor 5.

  A cross member 7 (so-called No. 3 cross member) extending in the vehicle width direction is provided between the back surface portion of the kick-up portion 2 and the lower surface of the front end portion of the rear seat pan 3, and the cross member 7 and each element 2 are provided. , 3 is formed with a closed cross section 8 extending in the vehicle width direction.

  A cross member upper 9 and a cross member lower 10 (so-called No. 4 cross member) extending in the vehicle width direction are joined and fixed to the upper and lower portions of the rear end portion of the rear seat pan 3. Between the member upper 9 and between the rear seat pan 3 and the cross member lower 10 are formed closed sections 11 and 12 that overlap in the vertical direction and extend in the vehicle width direction.

  Further, a rear cross member 13 (so-called No. 5 cross member) extending in the vehicle width direction is provided below the front portion of the load concave portion 4, and a vehicle width direction is provided between the rear cross member 13 and the load concave portion 4. A closed cross section 14 extending in the direction is formed.

A rear end member 15 extending in the vehicle width direction is provided on the front surface of the upper end portion of the rear end panel 6 described above, and a closed section 16 extending in the vehicle width direction is formed between the rear end member 15 and the rear end panel 6. ing.
The lower vehicle body rigidity is improved by the closed sections 8, 11, 12, 14, and 16 described above.

  As shown in FIG. 3, a fuel tank 18 as an auxiliary machine is attached to the lower portion of the rear seat pan 3 using a pair of left and right tank bands 17 and 17 (only one tank band is shown in the drawing). On the other hand, a silencer 19 is disposed below the cargo compartment recess 4, and a lower portion 19a of the silencer 19 is formed in a flat shape so as to have a rectifying structure. An insulator 20 for preventing thermal damage is disposed between the above-described cargo compartment recess 4 and the silencer 19.

Further, a rear end under cover 22 that is integral with or separate from the rear bumper 21 is provided, and the flat lower surface of the rear end under cover 22 and the flat lower portion 19a of the silencer 19 are continuous in the vehicle front-rear direction. The rear end under cover 22 forms a lower surface between the silencer 19 and the rear bumper 21.
2 and 3, reference numeral 23 denotes a bumper reinforcement that includes a bumper rain body 24 and a closing plate 25 and extends in the vehicle width direction.

  In FIG. 1, 26 is a front wheel and 27 is a rear wheel. As shown in FIGS. 1 and 5, the left and right rear wheels 27, 27 are suspended from the vehicle body by a torsion beam axle type (specifically, a coupled beam type) rear suspension 28.

  As shown in FIGS. 1 and 5, the rear suspension 28 includes a pair of left and right trailing arms 29, 29 and left and right spring seats provided at the rear portions of the pair of left and right trailing arms 29, 29, respectively. The spring lower seats 30, 30 and a torsion beam 31 (in the torsional direction) installed between the pair of left and right trailing arms 29, 29 above the left and right spring lower seats 30, 30 and in front of the vehicle in the vehicle width direction. A cross beam having elasticity).

  As shown in FIG. 5, the lower end of the rear wheel house inner 32 is joined and fixed to both ends of the rear floor 5 in the vehicle width direction, and the rear wheel house outer 32 is connected to the outer side of the rear wheel house inner 32 in the vehicle width direction. 33 is joined and fixed, and these both 32 and 33 constitute a rear wheel house.

  Further, as shown in FIG. 5, a rear side frame upper 34 and a rear side frame lower 35 are joined to both the upper and lower portions between both ends of the rear floor 5 in the vehicle width direction and the lower portion of the rear wheel house inner 32. Closed cross-sections 36 and 37 that are fixed and extend in the front-rear direction of the vehicle are formed.

  As shown in FIG. 4, a spring upper seat 38 is attached at a position facing the above-described spring lower seat 30 in the vertical direction and on the lower surface of the above-mentioned rear side frame lower 35. The spring upper seat 38 and the spring A coil spring 39 is stretched between the lower seat 30.

  As shown in FIG. 4, the above-described spring lower seat 30 is formed such that the lower surface thereof is inclined upward in the normal state. Here, the above-mentioned steady time means a time when the vehicle is traveling at a constant speed on a flat ground in a range from a state where only one driver is on board to a maximum loading capacity (or half of the maximum loading capacity).

Next, the lower rectification structure of the automobile will be described in detail.
As shown in FIG. 1, the lower part of the engine room has a vehicle floor surface covered from below by a front under cover 40 and a sub under cover 41 that are divided into a plurality of parts in the vehicle front-rear direction.
Further, the lower portion of the tunnel portion 1T (see FIG. 2) extending in the vehicle front-rear direction at the center in the vehicle width direction of the floor panel 1 forming the passenger compartment floor is covered with a tunnel under cover 42 from below, and the tunnel portion 1T The lower part of the floor panel 1 positioned on the left and right is covered from below with a pair of left and right center front side undercovers 43 and 43.

  Here, an exhaust port is provided in the cylinder head of the engine mounted in the engine room described above, and an exhaust pipe 44 is connected to an exhaust manifold connected in communication with the exhaust port. It extends toward the rear. The exhaust pipe 44 below the front floor of the vehicle body (specifically, the exhaust pipe up to the portion immediately before the kick-up portion 2 in plan view of the vehicle) is covered from below with the tunnel under cover 42 described above. The tunnel under cover 42 is formed with a plurality of rectangular holes 42a, 42a,... Spaced apart in the vehicle front-rear direction for the purpose of releasing heat from the exhaust pipe 44 downward, that is, outside the vehicle.

  The exhaust pipe 44 at the rear of the vehicle with respect to the tunnel undercover 42 described above extends rearward in the vehicle front-rear direction through the underside of an undercover (see the center rear side undercover 46 and the rear center undercover 47), which will be described later. The silencer 19 described above is connected to the rear end of the exhaust pipe 44, and tail pipes 45, 45 (so-called mufflers) extending in an L shape in the bottom view are provided on the left and right sides of the silencer 19 in the bottom view. It is connected.

  As shown in FIGS. 1 to 4, a center rear side under cover 46 is provided as a spring seat front side cover portion that covers the front part of the rear suspension 28 from the lower side than the spring lower seat 30. The center rear under cover 46 functions as a suspension front cover that covers the front part of the trailing arm 29 of the rear suspension 28 and the entire torsion beam 31 from below.

  In this embodiment, as shown in FIGS. 2, 3, and 4, the center rear side under cover 46 covers the fuel tank 18 that is an auxiliary machine having relatively low heat resistance from below.

  As shown in FIGS. 1 and 5, the above-described center rear side under cover 46 has a vehicle width direction center between the lower side of the torsion beam 31 and the rear end of each of the under covers 42 and 43 described above from the lower side. A central part 46C for covering, and a slope for inclining downward from both left and right ends in the vehicle width direction of the central part 46C in the vehicle front sectional view and extending outward in the vehicle width direction to cover the front part of the trailing arm 29 of the rear suspension 28 from below. Side portions 46S, 46S.

  Further, as shown in FIG. 1, a rear center under cover 47 is provided as a suspension center cover extending rearwardly between the spring lower seats 30 and 30 from the center portion in the vehicle width direction of the center rear side under cover 46. The rear center under cover 47 is also a central rear extension portion that extends further to the vehicle rear side than the above-described inclined side portion 46S at the center in the vehicle width direction. In this embodiment, the above-described rear center under cover 47 is formed in a trapezoidal shape when viewed from the bottom.

  As shown in FIGS. 1, 3, and 4, a rear side under cover 48 is provided as a spring seat rear cover portion that covers the lower floor behind the above-described spring lower seat 30 from below. As shown in the bottom view in FIG. 1, the rear side under cover 48 is located behind the trailing arm 29 and is divided into two parts on the left and right.

  As shown in FIG. 4, below the spring lower seat 30, an opening 49 that is not covered by the under cover, that is, any one of the center rear side under cover 46, the rear center under cover 47, and the rear side under cover 48. An opening 49 that is not covered by the cover is formed, and the opening 49 allows the spring lower seat 30 to move up and down.

  As shown in a bottom view in FIG. 1, the rear side under cover 48 and the rear wheel 27 are rearward of the rear side 27 and outside the end in the vehicle width direction of the silencer 19 in the vehicle width direction. Two openings 62 are provided, and the tail pipe 45 described above is disposed at a position corresponding to the second opening 62. Since a negative pressure is generated in the second opening 62 described above, the exhaust resistance can be reduced, which is preferable. Further, an under cover on the rear side of the rear wheel 27 and on the side of the silencer 19 in the vehicle width direction can be made unnecessary.

  The lower surface of the above-described center rear side undercover 46 is the lowest position of the spring lower seat 30 (the lowest position when the rear suspension 28 moves up and down corresponding to the behavior of the vehicle, see the phantom line α in FIG. 4). Is set higher than. As shown in FIGS. 4 and 6, the rear end of the inclined side portion 46S of the center rear side under cover 46 is bent downward so that the underfloor air is guided downward so as not to flow into the opening 49 described above. The peeled portion 50 of the underfloor wind e1 is formed. The rear end 50a of the peeling portion 50 acts as a peeling point of the underfloor wind e1.

  As shown in FIG. 4, the above-described rear side under cover 48 is separated from the above-described peeling portion 50 backward by a predetermined distance (specifically, separated rearward so as not to block the opening 49), and the rear side under cover 48 48 is formed with a convex lower surface 48b having a lowermost portion 48a at a position substantially equal to or higher than the rear end of the peeling portion 50. That is, the rear side under cover 48 has a side sectional shape that protrudes downward. In this embodiment, the lower surface 48b is inclined rearward and upward.

Here, the lowermost portion 48a described above is preferably formed in a curved shape as shown in the drawing in order to smoothly join the underfloor air after peeling by the peeling portion 50 and the air e3 above the under cover 46. .
Each of the undercovers 40, 41, 42, 43, 46, 47, 48 described above is made of synthetic resin or non-woven fabric.

  Further, as shown in FIG. 1, the floors of the front under cover 40, the sub under cover 41, the tunnel under cover 42, the center front under cover 43, the center portion 46C of the center rear under cover 46, and the rear center under cover 47, respectively. The surface is formed to be substantially flush.

  In short, as shown in FIGS. 1 and 4, in the lower flow straightening structure in which the vehicle floor surface is covered with an under cover, a center rear side under cover 46 that covers the front part from the lower side than the spring lower seat 30 of the rear suspension 28, A rear side under cover 48 that covers the under floor behind the spring lower seat 30 from below and an opening 49 that is formed below the spring lower seat 30 and is not covered by the under cover. The rear end of the center rear side undercover 46 is set to be higher than the lowest position of the lower seat 30 (see the phantom line α in FIG. 4) and guides the underfloor air e1 downward so as not to flow into the opening 49 (in detail). , The peeling portion 50 of the underfloor wind e1 bent downward is formed at the rear end of the inclined side portion 46S. The cover 48 is separated from the peeling portion 50 to the rear by a predetermined distance behind the opening 49, and a lower convex surface 48b having a lowermost portion 48a is formed at a position substantially equal to or higher than the peeling portion 50. It has been done.

  As a result, as shown in FIG. 4, the underfloor air e1 flowing on the lower surface of the center rear side undercover 46 is peeled off at the peeling point (rear end 50a) of the peeling portion 50, and the underfloor air after peeling is separated from the rear side undercover 48. The underfloor wind e2 after the reattachment is caused to flow rearward along the lower surface 48b of the rear side under cover 48. Here, the angle of the underfloor wind e2 after reattachment (an elevation angle with respect to the virtual horizon) is preferably parallel to or slightly loosen with the ideal wind flow.

  In addition, by providing an opening 49 that is not covered by the under cover at all below the spring lower seat 30 described above, it is necessary to cover the lower portion of the spring lower seat 30 that moves up and down in accordance with the behavior of the vehicle with the under cover. In addition, while ensuring the minimum ground clearance, the air e3 above the center rear side under cover 46 and the underfloor air e1 flowing on the lower surface of the center rear side under cover 46 are smoothly flowed backward to reduce aerodynamic resistance. It is configured as follows.

  Further, the lower surface of the spring lower seat 30 is formed so as to incline forward in the normal state, and the portion of the rear side under cover 48 in front of the vehicle is lower than the lowermost portion 48a of the rear side under cover 48 in the front and rear direction of the spring lower seat 30 in the normal state. A substantially continuous inclined surface 48c is formed on the front.

  As a result, the lower surface of the spring lower seat 30 that inclines forward in the normal state and the inclined surface 48c of the rear side under cover 48 are substantially continuous to the front, so that the air e3 above the center rear side under cover 46 is smoothly flown under the floor. It is configured to join the wind e2 and suppress the disturbance of the underfloor wind e2.

  Furthermore, the rear suspension 28 includes a pair of left and right trailing arms 29, a spring lower seat 30 provided at the rear of the pair of left and right trailing arms 29, and a left and right position at a position above the spring lower seat 30 and in front of the vehicle. A torsion beam 31 installed between the pair of trailing arms 29 in the vehicle width direction is provided, and the center rear side under cover 46 covers the entire torsion beam 31 from below.

Thus, the torsion beam 31 is covered by the center rear side under cover 46 so that the underfloor air e1 flowing on the lower surface of the under cover 46 is prevented from colliding with the torsion beam 31.
In addition, the above-described peeling portion 50 is formed so that the underfloor wind is reattached behind the lowermost portion 48a of the rear side under cover 48 during traveling at a speed of 30 km / h or more.

  Thus, during traveling at a speed of 30 km / h or more, the underfloor wind is reattached behind the lowermost portion 48a of the rear side under cover 48 by the peeling portion 50, and the underfloor wind e2 after reattachment is reattached to the rear side under cover 48. It is configured to smoothly flow to the rear of the vehicle along the lower surface 48b.

  On the other hand, as shown in FIG. 5, in the lower flow straightening structure in which an under cover (center rear side under cover 46, rear center under cover 47) is provided below the vehicle rear floor, the under cover is located at the center in the vehicle width direction from below. A central part 46C for covering, an inclined side part 46S that inclines downward from the central part 46C in a front sectional view and extends outward in the vehicle width direction and covers the front part of the trailing arm 29 of the rear suspension 28 from below; A rear center under cover 47 that extends rearward of the vehicle with respect to the inclined side portion 46S is provided at the center.

  As a result, the above-described inclined side portion 46S secures a vertical swing range of the trailing arm 29 and prevents interference between the trailing arm 29 and the center rear side under cover 46, while the central portion 46C. The slope side 46S is configured to promote the convergence of the underfloor wind toward the center in the vehicle width direction while suppressing the turbulence of the underfloor wind while ensuring the minimum ground clearance and covering more of the underfloor surface. Yes. The tilt angle θ (see FIG. 5) of the tilt side portion 46S is specifically a minute angle of 1 degree or less, but is exaggerated in the drawing.

  Further, a peeling portion 50 (see FIG. 4) of the underfloor air e1 bent downward is provided at the rear end of the inclined side portion 46S of the center rear undercover 46 described above. The underfloor air e1 is peeled off at the rear end of the inclined side portion 46S to prevent turbulent flow behind the side portion of the center rear side under cover 46.

  Further, as shown in FIG. 1, a shape in which the underfloor wind is guided to the center side in the vehicle width direction from the rear wheel 27 in front of the rear wheel 27 (a substantially triangular shape in a bottom view having a vertex on the vehicle front side). A deflector 51 is provided to prevent the underfloor wind from colliding with the rear wheel 27 by the deflector 51 and to concentrate the underfloor wind toward the center in the vehicle width direction so that the underfloor wind does not flow into the opening 49. It is configured to promote.

  In addition, as shown in FIG. 4, a rear side under cover 48 is provided at a position spaced a predetermined distance rearward from the peeling portion 50 at the rear end of the inclined side portion 46 </ b> S in the center rear side under cover 46. The underfloor wind is reattached to the rear side under cover 48 without flowing into the opening 49 to suppress the generation of turbulent flow and to suppress the disturbance of the underfloor wind focused in the center in the vehicle width direction. Yes.

  On the other hand, as shown in FIG. 1, in the lower rectifying structure provided with an under cover (center rear side under cover 46, rear center under cover 47, rear side under cover 48) that covers a part of the rear suspension 28 from below, The under cover includes a center rear side under cover 46 that covers the front part of the trailing arm 29 of the rear suspension 28 from below, a rear center under cover 47 that extends rearward from the center of the under cover 46 in the vehicle width direction, A rear side under cover 48 located behind the arm 29, and as shown in FIGS. 2, 3, and 4, each of these under covers 46, 47, 48 is provided with a fastener 52 (for the detailed structure of the fastener 52). , Which will be described later with reference to FIG. 9). However, as shown in FIGS. 3 and 4, a part of the rear side under cover 48 is supported by the vehicle body side member using the stay 54 and the fastener 52 described above.

  Thus, the under cover includes the center rear side under cover 46, the rear center under cover 47, and the rear side under cover 48. As a result, the entire rear suspension is covered from below with a single under cover. Each of them has an optimal shape, making it easier to ensure the minimum ground clearance, and the vibration characteristics of the under cover are advantageous over a structure in which a separate under cover is provided on the suspension movable part. It is configured as follows. In short, the above-described under covers 46, 47, 48 supported on the vehicle body side are configured to ensure both layout properties such as minimum ground clearance and ensuring vibration durability of the under cover.

  As shown in FIG. 4, the rear side under cover 46 is provided with a peeling portion 50 of the underfloor wind e1 bent downward at the rear end of the inclined side portion 46S as the side rear end of the center rear side under cover 46. Is a side sectional shape convex downward.

  Thus, the underfloor wind e1 is peeled off by the peeling portion 50, and the underfloor air after peeling is reattached to the rear side under cover 48 without flowing into the opening 49, thereby suppressing the occurrence of turbulence. ing. Further, the underfloor wind is caused to flow substantially straight rearward at the vehicle width direction center side, and the underfloor wind e1 is peeled off and reattached while ensuring the minimum ground clearance at the vehicle width direction side portion. In other words, the underfloor wind e1 that is not collected at the center in the vehicle width direction is peeled off.

  Further, as shown in FIG. 1, an exhaust pipe 44 is disposed below the rear center under cover 47. On the other hand, as shown in FIGS. The cover 48 itself can be attached and detached through 52. As a result, it is configured to ensure both the minimum ground clearance and the maintenance of the suspension.

  Specifically, during maintenance of the harness for brakes, etc., if the rear center under cover and the rear side under cover are integrated and the exhaust pipe is disposed below the rear center under cover, the exhaust pipe must be removed. However, in the above configuration, since the rear side under cover 48 is configured to be detachable as a single unit, it is not necessary to remove the exhaust pipe 44, and maintenance can be ensured. In addition, a single under cover that covers the entire rear suspension from the bottom is easy to ensure the minimum ground clearance, so that both the minimum ground clearance and maintainability of the undercarriage can be achieved. ing.

  In addition, as shown in FIGS. 4 and 7, a rear center under cover 47 as a suspension center cover is provided with an opening 47 a (or a notch) on the lower surface thereof, and a rear side frame as a vehicle body side member from its edge. A columnar vehicle body mounting portion 47 </ b> A having a wall surface 47 b extending upward toward the lower 35 is provided. In this embodiment, a half-tapered cone-shaped vehicle body mounting portion 47A is provided as the columnar vehicle body mounting portion 47A.

  The lower surface of the rear center under cover 47 described above is covered from below by a rear side under cover 48 as shown in FIG. As shown in FIG. 4, in this embodiment, a convex concave portion 48 d is formed integrally with a part of the rear side under cover 48, and the concave portion 48 d is formed on the rear center under cover 47 using a fastener 52. It is attached to the bottom surface.

  As a result, the rear center undercover 47 is provided with the vehicle body mounting portion 47A having the above-described structure, so that it is not necessary to use a separate stay or the like for mounting the undercover, and the number of mounting parts can be reduced. The rear center under cover 47 itself is configured to ensure rigidity and mounting strength. Further, the lower surface of the rear center under cover 47 is covered with a rear side under cover 48 from below so that the aerodynamic resistance is not increased. Further, the rear center under cover 47 and the rear side under cover 48 are formed in shapes corresponding to each of them, so that maintenance is ensured.

As shown in FIGS. 2 and 7, the rear center under cover 47 is formed in a box shape having a substantially trapezoidal shape when viewed from the bottom and an open top when viewed from the side as shown in FIG.
The vehicle body attachment portion 47A described above is formed so as to rise upward from both left and right outer ends of the rear center under cover 47 in the vehicle width direction.

  Further, an upwardly protruding arrangement portion 47c corresponding to the arrangement structure of the exhaust pipe 44 is integrally formed at the bottom of the rear center under cover 47, and on the lower surface side of the arrangement portion 47c, FIG. As shown in FIG. 2, the rear portions of the insulator 60B and the exhaust pipe 44 are arranged.

  Further, as shown in FIGS. 2, 4, and 7, attachment portions 47d and 47e to the vehicle body side member are integrally formed on the front and rear pieces of the rear center under cover 47, and the front attachment portion 47d is The fastener 52 is attached to the cross member lower 10, and the rear attachment portion 47 e is attached to the rear cross member 13 and the rear side frame lower 35 using the fastener 52.

FIG. 8 is a partially enlarged view of FIG. 5. As shown in FIGS. 1 and 8, a part of the rear suspension 28, specifically, the front part of the trailing arm 29 and the torsion beam 31 are covered from below. The above-described center rear under cover 46, an exhaust pipe 44 positioned below the center rear under cover 46 and extending in the front-rear direction of the vehicle, and continuous with the lower surface of the center rear under cover 46, and exhausted. An insulator 60A that covers the tube 44 close to the tube 44 from above is provided.
As a result, the exhaust pipe 44 is disposed below the center rear under cover 46, and the clearance and irregularities in the insulator 60A are reduced, thereby improving the aerodynamic characteristics and the lowest ground of the center rear under cover 46. It is configured so as to achieve both high securing and prevention of heat damage from the exhaust pipe 44 to the passenger compartment side.

Further, as shown in FIG. 8, a part of the exhaust pipe 44 described above, specifically, the lower surface side protrudes below the lower surfaces of the center rear undercover 46 and the insulator 60A, and the exhaust pipe The outer peripheral side surface of 44 is disposed close to the inner peripheral surface of the insulator 60A.
Thus, the clearance between the insulator 60A and the exhaust pipe 44 is reduced as much as possible while keeping the minimum ground clearance of the center rear side under cover 46 high.

Further, as shown in FIG. 4, a fuel tank 18 is provided under the rear floor of the vehicle body as an example of an auxiliary machine having relatively low heat resistance. On the other hand, as shown in FIG. 1, the exhaust pipe 44 under the front floor of the vehicle body is covered with a tunnel under cover 42 from below.
Thus, the protection of the auxiliary machine (fuel tank 18), which is relatively vulnerable to heat damage, and the improvement of aerodynamic characteristics by covering the exhaust pipe 44 with the tunnel under cover 42 are configured.

  In addition, as shown in FIG. 8, the above-described insulator 60 </ b> A has an upward convex storage portion 60 a for storing the upper surface portion of the exhaust pipe 44 (in this embodiment, the upward convex convex semicircular storage portion). In addition, cooling lower surface portions 60b and 60b located between the lower portion of the storage portion 60a and the center rear side under cover 46 are integrally formed. The above-described cooling lower surface portion 60b also serves as a mounting portion for the under cover 46 of the insulator 60A. In this embodiment, the insulator 60A described above is formed of aluminum or an aluminum alloy.

  As a result, the heat of the exhaust pipe 44 is prevented from conducting heat to the center rear side undercover 46 at the cooling lower surface portion 60b, and the upper surface portion of the exhaust pipe 44 (the majority in this embodiment) is installed in the insulator 60A. Part) is stored so as to reduce aerodynamic resistance.

In FIG. 8, the left and right cooling lower surface portions 60 b and 60 b of the insulator 60 </ b> A are attached to the lower surface of the center rear side under cover 46 using fasteners 52.
As shown in FIG. 9, the above-described fastener 52 includes a fastener main body 52A having a locking piece 52c having a locking claw 52a at the distal end and a flange 52b at the proximal end, a shaft portion 52d, and a flange portion 52e. The lock pin 52B is integrally formed.

  As shown in FIG. 9A, the fastener main body 52A is set in advance in the attachment holes 53 for mounting the fastener 52 formed in the elements 60A and 46, and the fastener main body 52A is viewed from the direction of the arrow in FIG. When the lock pin 52B is inserted into the hole, the locking piece 52c is expanded in diameter as shown in FIG. 9B, and the both 60A and 46 are clamped and fixed between the locking claw 52a and the flange 52b. To do.

  FIG. 10 is a cross-sectional view showing a related structure of the rear center under cover 47, the insulator 60B, and the exhaust pipe 44. As shown in FIG.

  As shown in FIG. 10, the cross-sectional structure of the insulator 60B disposed in the convex portion 47c on the rear center undercover 47 is also the cross section of the insulator 60A on the center rear side undercover 46 side shown in FIG. Since the structure is the same, the same parts of these insulators 60B and 60A are denoted by the same reference numerals, and detailed description thereof is omitted.

  Then, as shown in FIG. 10, the lower surface 60b for cooling of the insulator 60B is attached to the lower left and right of the arrangement portion 47c of the rear center under cover 47 using the fasteners 52 having the same structure as described above, and the heat of the exhaust pipe 44 is It is configured to prevent transmission to the cargo room side above it.

Further, as shown in FIG. 10, the aerodynamic resistance is reduced by storing the upper surface portion (in this embodiment, the majority) of the exhaust pipe 44 in the insulator 60B.
6 and 7, arrow F indicates the front of the vehicle, and arrow R indicates the rear of the vehicle.

  As described above, the lower rectification structure of the automobile of the above embodiment is a lower rectification structure of the automobile in which the vehicle floor is covered with the undercovers 46 and 48, and the front portion of the rear suspension 28 is lower than the spring lower seat 30. A spring seat front cover portion (center rear under cover 46) that covers from below, a spring seat rear cover portion (rear side under cover 48) that covers the floor below the spring lower seat 30, and a lower portion of the spring lower seat 30. And an opening 49 that is not covered by the under cover, and the lower surface of the spring seat front cover portion (center rear under cover 46) is lower than the lowest position of the spring lower seat 30 (see phantom line α in FIG. 4). It should be set high and the underfloor wind should be guided downward so as not to flow into the opening 49. A release portion 50 of the underfloor wind e1 bent downward is formed at the rear end of the spring seat front cover portion (center rear under cover 46), and the spring seat rear cover portion (rear side under cover 48) is formed of the release portion. A downwardly projecting lower surface 48b having a lowermost portion 48a is formed at a position spaced apart from the opening 50 by a predetermined distance behind the opening 49 and having a height substantially equal to or higher than the peeling portion 50. Yes (see FIGS. 1 and 4).

According to this configuration, the underfloor air e1 flowing on the lower surface of the spring seat front cover portion (center rear undercover 46) of the undercover is peeled off by the peeling portion 50, and the underfloor air after peeling is separated from the spring seat rear cover. The underfloor wind e2 after reattachment to the lowermost portion 48a of the rear portion (rear side under cover 48) can flow to the rear of the vehicle along the lower surface 48b of the spring seat rear side cover portion (rear side under cover 48).
In addition, since the opening 49 is provided below the spring lower seat 30, it is not necessary to cover the lower portion of the spring lower seat 30 that moves up and down in accordance with the behavior of the vehicle with an under cover, and the spring seat while ensuring the minimum ground clearance. The air e3 above the front cover (center rear undercover 46) and the underfloor air e1 flowing through the lower surface of the spring seat front cover (center rear undercover 46) can flow smoothly backward, and aerodynamic resistance Can be reduced.

In one embodiment of the present invention, the lower surface of the spring lower seat 30 is formed so as to incline forward in the normal state, and is located in front of the vehicle lower than the lowermost portion 48a of the spring seat rear cover portion (rear side under cover 48). This part is configured to form an inclined surface 48c that is substantially continuous with the lower surface of the spring lower seat 30 and the front and rear in the vehicle front-rear direction (see FIG. 4).
Here, the above-mentioned steady time means a time when the vehicle is traveling at a constant speed on a flat ground in a range from a state where only one driver is on board to a maximum loading capacity (or half of the maximum loading capacity).

  According to this configuration, since the lower surface of the spring lower seat 30 that inclines forward in the normal state and the inclined surface 48c of the spring seat rear side cover portion (rear side under cover 48) are substantially continuous to the front, the spring seat The air e3 above the front cover portion (center rear under cover 46) can be smoothly merged with the underfloor air e2, and the disturbance of the underfloor air e2 can be suppressed.

  In one embodiment of the present invention, the rear suspension 28 includes a pair of left and right trailing arms 29, the spring lower seat 30 provided at the rear of the pair of left and right trailing arms 29, and the spring lower seat 30. And a torsion beam 31 erected in the vehicle width direction between the pair of left and right trailing arms 29, 29 at a position above and in front of the vehicle, and the spring seat front side cover portion (center rear side under cover 46) is the torsion beam. 31 is covered from below (see FIG. 1).

  According to this configuration, since the torsion beam 31 is covered by the spring seat front side cover portion (center rear side under cover 46), the underfloor air e1 flowing through the lower surface of the spring seat front side cover portion (center rear side under cover 46) is the torsion beam 31. Can be prevented from colliding.

  In one embodiment of the present invention, the peeling portion 50 has an underfloor wind behind the lowermost portion 48a of the spring seat rear side cover portion (rear side under cover 48) during traveling at a speed of 30 km / h or more. It is formed to reattach (see FIG. 4).

  According to this configuration, during traveling at a speed of 30 km / h or more, the underfloor wind is reattached behind the lowermost part 48a of the spring seat rear side cover part (rear side under cover 48) by the peeling part 50. The underfloor air e2 after adhering can flow smoothly to the rear of the vehicle along the lower surface of the cover portion (rear side under cover 48) on the rear side of the spring seat.

In the correspondence between the configuration of the present invention and the above-described embodiment,
The spring seat of the present invention corresponds to the spring lower seat 30 of the embodiment,
Similarly,
The front cover portion of the spring seat corresponds to the center rear side under cover 46,
The spring seat rear cover portion corresponds to the rear side under cover 48,
The present invention is not limited to the configuration of the above-described embodiment.
For example, at least two of the covers 46, 47, 48 may be integrally formed.

  As described above, the present invention is useful for the lower rectification structure of an automobile in which the vehicle floor is covered with an undercover.

28 ... Rear suspension 29 ... Trailing arm 30 ... Spring lower seat (spring seat)
31 ... Torsion beam 46 ... Center rear under cover (spring seat front cover)
48 ... Rear side under cover (Spring seat rear cover)
48a ... Bottom 48b ... Bottom 48c ... Inclined surface 49 ... Opening 50 ... Peeling part

Claims (4)

It is a lower rectification structure of an automobile whose vehicle floor is covered with an undercover,
A spring seat front side cover portion that covers the front part from below the spring seat of the rear suspension;
A spring seat rear cover that covers the floor below the spring seat, and
An opening formed below the spring seat and not covered with an under cover,
The lower surface of the front cover portion of the spring seat is set higher than the lowest position of the spring seat,
An underfloor peeling portion bent downward is formed at the rear end of the front cover portion of the spring seat so as to guide the underfloor air downward so as not to flow into the opening,
The spring seat rear cover portion is spaced downward from the peeling portion by a predetermined distance behind the opening, and has a lower convex bottom surface having a lowermost portion at a height approximately equal to or higher than the peeling portion. A lower rectification structure of an automobile characterized in that is formed. The lower surface of the spring seat is formed so as to incline forward at the normal time,
The portion of the front side of the vehicle relative to the lowermost part of the rear cover portion of the spring seat forms an inclined surface that is substantially continuous with the lower surface of the spring seat and the front and rear in the vehicle front-rear direction. The lower rectification structure of the described automobile. The rear suspension includes a pair of left and right trailing arms,
The spring seat provided at the rear of the pair of left and right trailing arms;
A torsion beam constructed in the vehicle width direction between a pair of left and right trailing arms at a position above the spring seat and in front of the vehicle;
The lower rectifying structure for an automobile according to claim 1, wherein the front cover portion of the spring seat covers the torsion beam from below. The said peeling part is formed so that underfloor wind may adhere again behind the lowest part of the said spring seat rear side cover part during driving | running | working at the speed of 30 km / h or more. The lower rectification structure of the automobile according to the item.

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