JP2008230354A - Spare tire storage part structure and vehicle body lower part structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spare tire storage part structure capable of restraining sounding volume accompanying vibration of a vehicle body floor at a spare tire storage portion and a vehicle body lower part structure. <P>SOLUTION: A protruded bead 40 to support a spare tire 28 is arranged at an adjacent position of a boundary part 36 of a side wall part 34 and a bottom wall part 32 at a storage recessed part 30, set high in rigidity against the vertical direction of a vehicle body in comparison with the bottom wall part 32 and formed in a curved shape along an outline shape of the spare tire 28 stored in the storage recessed part 30. Consequently, supporting rigidity of the spare tire 28 is improved and a part along a portion 28C toward the side from a portion 28B toward the lower side of the spare tire 28 in a storing state of the spare tire 28 is stably supported by the protruded bead 40 in a continuous surface contacting state. Accordingly, resonance frequency of a rear floor pan 12A rises and slips off out of a frequency band territory high in acoustic sensitivity. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a spare tire storage part structure and a vehicle body lower part structure in which a spare tire is stored.

In the spare tire storage structure at the lower part of the vehicle body, a structure is known in which a spare tire is supported by contacting the bottom surface of the rear floor pan (see, for example, Patent Document 1). In such a structure, the resonance frequency of the rear floor pan panel generally exists in a low frequency band (20 to 30 Hz). However, in this frequency band, the acoustic sensitivity of the front seat of the rear floor is often high, and in such a case, if the vibration of the rear floor pan panel is amplified by being excited by the vibration of the rear side member, the volume of the booming sound is increased. growing.
JP 2006-35893 A

  In view of the above facts, an object of the present invention is to provide a spare tire storage unit structure and a vehicle body lower part structure that can suppress the amount of sound generated due to vibration of the vehicle body floor at the spare tire storage site.

  The spare tire storage portion structure of the present invention described in claim 1 constitutes a part of the vehicle body floor, and forms a storage recess for storing a spare tire that is formed in a concave shape and includes a side wall portion and a bottom wall portion. A spare that is disposed near the boundary between the floor pan and the side wall portion and the bottom wall portion, has higher rigidity in the vertical direction of the vehicle body than the bottom wall portion, and is stored in the storage recess. And a support means which is formed in a curved shape along the outer shape of the tire and supports the spare tire.

  According to the spare tire storage portion structure of the present invention described in claim 1, the support means for supporting the spare tire is disposed in a proximity position of the boundary portion between the side wall portion and the bottom wall portion, and compared with the bottom wall portion. Since the rigidity in the vertical direction of the vehicle body is set high, the support rigidity of the spare tire is increased, and when the vibration is input from the engine or the like with the spare tire stored, the bottom wall portion (when there is no support means) (Compared) It is hard to vibrate. Furthermore, since the support means is formed in a curved shape along the outer shape of the spare tire stored in the storage recess, in the storage state of the spare tire, from the portion directed downward of the spare tire to the side side A portion extending to the directed portion is stably supported by the support means in a continuous surface contact state, and a load action on the bottom wall portion is suppressed when vibration is input from an engine or the like. For this reason, when vibration is input from the engine or the like in a state where the spare tire is stored, vertical vibration in the bottom wall portion of the storage recess of the floor pan is effectively reduced. As a result, the resonance frequency of the floor pan rises and deviates from the frequency band with high acoustic sensitivity.

  According to a second aspect of the present invention, there is provided a spare tire storage portion structure according to the first aspect, wherein the support means constitutes a part of the floor pan, and a boundary between the side wall portion and the bottom wall portion. It is a bead formed so as to protrude from the portion toward the inside of the storage recess.

  According to the spare tire storage portion structure of the present invention as set forth in claim 2, the support means constitutes a part of the floor pan and protrudes from the boundary portion between the side wall portion and the bottom wall portion toward the inside of the storage recess portion. Therefore, the shape of the floor pan after molding is not easily deformed, and the support rigidity of the spare tire is ensured with a simple configuration.

  According to a third aspect of the present invention, there is provided a vehicle body lower structure according to the present invention, wherein the vehicle body floor is disposed at a lower portion of the vehicle body and has a storage recess for storing a spare tire having a side wall portion and a bottom wall portion. It is arranged at a position close to the boundary with the bottom wall, has a higher rigidity in the vertical direction of the vehicle body than the bottom wall, and is curved along the outer shape of the spare tire stored in the storage recess. And supporting means for supporting the spare tire.

  According to the vehicle body lower structure of the present invention as set forth in claim 3, the support means for supporting the spare tire is disposed in the vicinity of the boundary portion between the side wall portion and the bottom wall portion, and the vehicle body as compared with the bottom wall portion. Since the rigidity in the vertical direction is set high, the support rigidity of the spare tire is increased, and when the vibration is input from the engine or the like with the spare tire stored, the bottom wall portion (compared to the case without the support means) ) Hard to vibrate. Furthermore, since the support means is formed in a curved shape along the outer shape of the spare tire stored in the storage recess, in the storage state of the spare tire, from the portion directed downward of the spare tire to the side side A portion extending to the directed portion is stably supported by the support means in a continuous surface contact state, and a load action on the bottom wall portion is suppressed when vibration is input from an engine or the like. For this reason, when vibration is input from the engine or the like in a state where the spare tire is stored, the vertical vibration in the bottom wall portion of the storage recess is effectively reduced. As a result, the resonance frequency of the vehicle body floor rises and deviates from the frequency band with high acoustic sensitivity.

  According to a fourth aspect of the present invention, the vehicle body lower part structure according to the present invention is the structure according to the third aspect, wherein the support means constitutes a part of the vehicle body floor and from a boundary portion between the side wall portion and the bottom wall portion. It is a bead formed so as to protrude toward the inside of the storage recess.

  According to the vehicle body lower structure of the present invention as set forth in claim 4, since the supporting means is a bead formed so as to protrude from the boundary portion between the side wall portion and the bottom wall portion toward the inside of the housing recess, The shape of the rear body floor is difficult to deform, and the support rigidity of the spare tire is ensured with a simple configuration.

  As described above, according to the spare tire storage portion structure according to claim 1 of the present invention, it is possible to suppress the amount of sound generated due to vibration of the vehicle body floor (floor pan) at the spare tire storage site. Has an excellent effect.

  According to the spare tire storage portion structure according to claim 2, the amount of sound generated by the vibration of the floor pan at the spare tire storage portion is improved with a simple configuration while improving the shape retainability of the floor pan in which the spare tire is stored. It has the outstanding effect that it can suppress.

  According to the vehicle body lower part structure of the third aspect, there is an excellent effect that it is possible to suppress the sound generation amount accompanying the vibration of the vehicle body floor at the spare tire storage site.

  According to the vehicle body lower structure according to claim 4, the shape retention of the vehicle body floor in which the spare tire is stored is improved, and the amount of sound generated due to the vibration of the vehicle body floor at the spare tire storage site is suppressed with a simple configuration. It has an excellent effect of being able to.

(Configuration of the embodiment)
Embodiments of a spare tire storage portion structure and a vehicle body lower structure in the present invention will be described with reference to the drawings. In the figure, the arrow UP indicates the upward direction of the vehicle body, the arrow RE indicates the backward direction of the vehicle body, and the arrow IN indicates the inside of the vehicle width direction. In the present embodiment, a case where the present invention is applied to a sedan vehicle will be described as an example. However, applicable vehicles are not limited to sedan vehicles.

  FIG. 1 is a plan view showing the overall configuration of the vehicle body lower structure including the spare tire storage unit structure at the rear of the vehicle body, and FIG. 2 shows the vehicle body lower structure including the spare tire storage unit structure. Is shown in a rear view with the lower back removed. 3 is an enlarged sectional view taken along line 3-3 in FIG. 1, and FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG.

  As shown in FIGS. 1 to 3, a pair of left and right elongated rear side members 14 extend substantially in the longitudinal direction of the vehicle body on both sides of the lower surface of a rear floor 12 as a vehicle body floor disposed in the rear lower portion 10 of the vehicle body. is doing. As shown in FIGS. 2 and 3, the rear side member 14 is a strength member having an inverted cross-section hat shape that is open on the upper side of the vehicle body, and is welded to the lower surface side of the rear floor 12 to form a closed cross section. As shown in FIG. 1, the rear side member 14 has a shape in which the rear portion 14B is narrowed inward in the vehicle width direction so as to bypass a rear wheel (not shown) with respect to the front portion 14A when viewed in a plan view. . Between the left and right rear side members 14, a rear cross member 16 having a longitudinal direction in the vehicle width direction is stretched.

  As shown in FIG. 2, the rear floor 12 is disposed in the rear lower portion 10 of the vehicle body and constitutes a floor surface of a luggage room (luggage space) 11. The luggage room 11 is separated from a cabin (not shown) provided on the front side of the vehicle body from the luggage room 11 by a rear portion of a rear seat (not shown). In the present embodiment, the luggage room 11 and the cabin (not shown) are communicated with each other by a through hole (not shown) formed on the rear lower side of the rear glass (not shown) at the partition portion. The vibration eigenmode determined by the volume is around 30 Hz (see FIG. 6). In other words, when there is vibration with a frequency near 30 Hz in the luggage room 11, it is easy for the passenger's ears to hear the in-vehicle sound (ie, the booming sound). Incidentally, in general sedan-type vehicles, the vibration eigenmode is almost 30 Hz.

  As shown in FIG. 4, a plate-like lower back 18 erected substantially on the upper side of the vehicle body is welded to a rear end upper surface portion of a rear floor pan 12 </ b> A (described later in detail) in the rear floor 12. A rear end portion of the rear portion 14B of the rear side member 14 shown in FIG.

  In the rear floor 12, a storage recess 30 for storing a spare tire 28 (see FIG. 3) that is recessed in a concave shape when viewed from the upper side of the vehicle body is formed at the center between the rear portions 14B of the rear side member 14. In the present embodiment, the storage recess 30 includes a rear floor pan 12A formed by press molding or the like in a substantially reverse hat shape including a concave portion when viewed from the rear of the vehicle, and a vehicle front side of the rear floor pan 12A as shown in FIG. And a front panel 12B which is welded to the upper surface and forms the front wall of the storage recess 30. The rear floor pan 12 </ b> A and the front panel 12 </ b> B are both panel members that constitute a part of the rear floor 12. As shown in FIG. 2, the storage recess 30 is formed in a substantially disc shape and forms a bottom wall surface 32, and a side wall portion extending substantially upward from the peripheral edge of the bottom wall portion 32. And a side wall 34 that constitutes a wall surface (vertical wall), and as shown in FIG. Has been.

  As shown in FIG. 2, a spare tire carrier 20 is attached to a substantially central portion of the bottom wall portion 32 of the storage recess 30. The spare tire carrier 20 has a substantially hat shape when viewed from the rear of the vehicle body, a flat top 20A, and a pair of left and right legs 20B that are bent and suspended from both side ends in the vehicle width direction of the top 20A. It has. The lower portions of the pair of leg portions 20B are bent in directions away from each other, and are welded to the bottom wall portion 32 of the storage recess 30. A screw hole 22 is formed through the top portion 20A. As shown in FIG. 4, a spare wheel clamp 24 can be screwed into the screw hole 22 from above the vehicle body. The spare wheel clamp 24 is passed through the tire wheel 28 </ b> A of the spare tire 28, and the screw hole 22. The spare tire 28 can be fixed to the spare tire carrier 20 by being screwed together.

  As shown in FIGS. 2 and 3, as a support structure for the spare tire 28, a rear floor pan 12 </ b> A (rear floor) is provided in the storage recess 30 in the vicinity of the boundary portion 36 between the side wall portion 34 and the bottom wall portion 32. 12) and a total of four convex beads 40 (two on the left and right sides in the vehicle width direction) as support means formed so as to protrude from the boundary 36 toward the inside of the housing recess 30. Are arranged (set). Each convex bead 40 is used for supporting a spare tire that can support the spare tire 28, and has higher rigidity in the vertical direction of the vehicle body than the bottom wall portion 32. Further, the convex bead 40 is formed in a curved shape along the outer shape of the spare tire 28 stored in the storage recess 30, and includes an upright wall portion 40 </ b> A that rises substantially upward on the vehicle body.

  As shown in FIG. 3, when the spare tire 28 is stored (mounted), the part 28 </ b> C directed from the part 28 </ b> B directed downward to the side of the spare bead 40 with respect to the convex bead 40. The part extending to is continuously in surface contact, and the part 28C directed to the side of the spare tire 28 is supported by the standing wall 40A.

(Operation and effect of the embodiment)
Next, the operation and effect of the above embodiment will be described.

  As shown in FIG. 3, the convex bead 40 that supports the spare tire 28 is disposed in the proximity of the boundary portion 36 between the side wall portion 34 and the bottom wall portion 32 in the storage concave portion 30. Since the rigidity in the vertical direction of the vehicle body is set higher than that of the vehicle body, the support rigidity of the spare tire 28 is increased, and the bottom wall portion 32 (convex bead 40) is input when vibration is input from the engine or the like with the spare tire 28 stored. It is hard to vibrate compared to the case without Further, since the convex bead 40 is formed in a curved shape along the outer shape of the spare tire 28 stored in the storage recess 30, the portion directed toward the lower side of the spare tire 28 when the spare tire 28 is stored. A portion from 28B to the side portion 28C directed to the side is stably supported by the convex bead 40 in a continuous surface contact state, and the load action on the bottom wall portion 32 is suppressed when vibration is input from the engine or the like. .

  Therefore, even when the rear end of the rear floor pan 12A shown in FIG. 4 vibrates substantially in the vehicle body vertical direction (arrow X direction) when vibration is input from the engine or the like with the spare tire 28 stored (two points). Even in the rear floor pan vibration mode indicated by the chain line), the vertical vibration in the bottom wall portion 32 (general surface) of the housing recess 30 is effectively reduced as compared with the contrast structure without the convex bead 40 (see FIG. 3). . As a result, the resonance frequency of the rear floor pan 12A (rear floor 12) increases and deviates from the frequency band with high acoustic sensitivity (change of the resonance vibration frequency of the rear floor pan 12A).

  Supplementally, in the low frequency band (20 to 30 Hz), the vehicle body (body) is bent and deformed so that the front and rear end sides of the vehicle body are displaced in the vertical direction of the vehicle body when viewed from the side of the vehicle body (so-called two-node bending or three-node bending of the vehicle body) When the rear floor pan 12A vibrates due to the vibration of the rear side member 14 (see FIG. 3) excited by the engine input, the suspension input, etc., the contrast structure in which the convex bead 40 (see FIG. 3) is not disposed is A booming sound (in-car sound) is likely to occur. In particular, a sedan-type vehicle has a high acoustic sensitivity of the front seat of the rear floor with respect to the vibration of the rear floor pan 12A in a low frequency band (20 to 30 Hz). Since the resonance frequency of the pan 12A (rear floor 12) deviates from the frequency band in which the sound volume is large in the passenger compartment, the muffled sound accompanying the vibration of the rear floor pan 12A (rear floor 12) hardly poses a problem.

  Here, FIG. 5 shows a response level when an external force is applied to the joint portion with the spare tire carrier 20 in the rear floor pan 12 </ b> A shown in FIG. 4, that is, a vibration level distribution for each frequency. In FIG. 6, the acoustic sensitivity of the rear floor front seat for each frequency is shown. In the graph of FIG. 5, the dotted line shows the case of the contrast structure in which the spare tire 28 is placed directly without the convex bead 40 being arranged, and the solid line shows the case of this embodiment, and the higher the vibration level, the larger the amplitude. Is large.

  As shown in FIG. 5, when the contrast structure is applied, the resonance frequency (frequency at which the vibration level reaches a peak) is around 30 Hz with the mass of about 20 kg of the spare tire 28 being added as the mass of the mass. It has become. On the other hand, when this embodiment is applied, the vibration level in the vicinity of 30 Hz can be reduced as compared with the case of the contrast structure. As shown in FIG. 6, since the acoustic sensitivity is high (bad) in the vicinity of 30 Hz, the sound level associated with the vibration of the rear floor pan 12A (rear floor 12) is reduced by reducing the vibration level in the vicinity of 30 Hz.

  Further, as shown in FIG. 5, when this embodiment is applied, the resonance frequency (frequency at which the vibration level reaches a peak) that was around 30 Hz in the case of the contrast structure can be raised to around 60 Hz. it can. As shown in FIG. 3, the spare tire 28 is not placed directly on the bottom wall portion 32 but is supported in a continuous surface contact state by the convex bead 40 including the standing wall portion 40 </ b> A, and the spare tire 28 is supported. This is because the rigidity is ensured. Here, as shown in FIG. 6, since the acoustic sensitivity is low (good) in the vicinity of 60 Hz, there is almost no problem in sound generation when the resonance frequency is changed to around 60 Hz.

  Further, according to the spare tire storage structure and the vehicle body lower structure of the present embodiment, even if there is a large vibration input when traveling on a rough road, the mass of the spare tire 28 is increased by the standing wall 40A of the convex bead 40 shown in FIG. 4 is supported, the peeling stress at the peeling spot 46 where the front panel 12B and the bottom wall 32 of the rear floor pan 12A shown in FIG. 4 are overlapped and welded is reduced (rough road durability strength performance). Improvement).

  Further, the convex bead 40 shown in FIG. 3 is formed so as to protrude from the boundary portion 36 between the side wall portion 34 and the bottom wall portion 32 toward the inside of the storage concave portion 30, so that the rear floor pan 12A (rear floor 12) It can be shared as a bead for shape retention (freezing of shape). Therefore, the shape of the molded rear floor pan 12A (rear floor 12) is not easily deformed, and the support rigidity of the spare tire 28 is ensured with a simple configuration.

  As described above, according to the spare tire storage portion structure and the vehicle body lower structure of the present embodiment, the shape retaining property of the rear floor pan 12A (rear floor 12) in which the spare tire 28 is stored is improved and simplified. With the configuration, it is possible to suppress the amount of sound generated due to the vibration of the rear floor pan 12A (rear floor 12) at the storage portion of the spare tire 28 (reduction of low frequency booming noise).

(Supplementary explanation of the embodiment)
In the above-described embodiment, the convex bead 40 formed so as to protrude from the boundary portion 36 between the side wall portion 34 and the bottom wall portion 32 toward the inside of the storage concave portion 30 is used as a support means for supporting the spare tire 28. However, the support means is, for example, formed in a curved shape along the outer shape of the spare tire stored in the storage recess, and is welded to the floor pan (body floor) to thereby form the side wall portion and the bottom wall portion. It may be another supporting means such as constituted by a supporting member disposed in the vicinity of the boundary portion. The supporting member may be disposed (continuously) with the direction along the boundary between the side wall and the bottom wall as the longitudinal direction. Further, as shown in FIG. 2, in the above embodiment, the convex beads 40 are arranged in a total of four places, but the beads are arranged in places other than the total four places (preferably three or more places in terms of support performance). ).

  Further, the spare tire storage portion structure and the vehicle body lower structure are configured such that the spare tire 28 (a portion excluding the tire wheel 28A) shown in FIG. 3 is supported by the convex bead 40 and a part thereof is supported by the bottom wall portion 32. Alternatively, it may be configured to support only the convex bead 40.

  Further, in the above embodiment, as shown in FIG. 4, the storage recess 30 is configured by a plurality of members including the rear floor pan 12A and the front panel 12B, but the storage recess is configured only by the rear floor pan. May be. Further, in the above-described embodiment, the storage recess 30 is formed in the vehicle body rear lower part 10, but the storage recess may be formed in the vehicle body lower part other than the vehicle body rear lower part 10.

It is a top view which shows the spare tire storage part structure and vehicle body lower part structure which concern on embodiment of this invention (in the state which removed the upper body). It is a rear view which shows the spare tire storage part structure and vehicle body lower part structure which concern on embodiment of this invention (in the state which removed the lower back). It is an expanded sectional view which follows the 3-3 line of FIG. FIG. 4 is an enlarged cross-sectional view taken along line 4-4 of FIG. It is a graph which shows the vibration level distribution for every frequency at the time of being vibrated to a junction part with a spare tire carrier with a rear floor pan. It is a graph which shows the acoustic sensitivity of the rear floor front seat for every frequency.

Explanation of symbols

10 Rear lower part of vehicle body (lower part of vehicle body)
12 Rear floor (body floor)
12A Rear floor pan 28 Spare tire 30 Storage recess 32 Bottom wall portion 34 Side wall portion 36 Boundary portion 40 Convex bead (support means)

Claims (4)

A floor pan that constitutes a part of the vehicle body floor and that forms a recessed portion for storing a spare tire that is formed in a concave shape and includes a side wall portion and a bottom wall portion;
The outer shape of the spare tire that is disposed near the boundary portion between the side wall portion and the bottom wall portion, has higher rigidity in the vehicle body vertical direction than the bottom wall portion, and is stored in the storage recess. A support means for supporting the spare tire, which is formed in a curved shape along
A spare tire storage portion structure characterized by comprising:   The support means is a bead that forms a part of the floor pan and is raised from the boundary between the side wall and the bottom wall toward the inside of the storage recess. The spare tire storage part structure according to claim 1. A vehicle body floor disposed at a lower portion of the vehicle body and formed with a storage recess for storing a spare tire having a side wall portion and a bottom wall portion;
The outer shape of the spare tire that is disposed near the boundary portion between the side wall portion and the bottom wall portion, has higher rigidity in the vehicle body vertical direction than the bottom wall portion, and is stored in the storage recess. A support means for supporting the spare tire, which is formed in a curved shape along
The vehicle body lower structure characterized by having.   The support means is a bead that forms a part of the vehicle body floor and is raised from the boundary between the side wall and the bottom wall toward the inside of the storage recess. The vehicle body lower structure according to claim 3.

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