JP2015077940A - Vehicle rear part structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit noise from occurring from a vehicle rear part when a vehicle travels.SOLUTION: A vehicle rear part structure S1 includes: wheel houses 12 provided at left and right parts of a vehicle rear part; a cross member 14 which extends in a vehicle width direction and connects the wheel houses 12 with each other; and support parts 16, each of which connects the wheel house 12 with an upper surface part of a vehicle width direction end part of the cross member 14.

Description

  The present invention relates to a vehicle rear structure.

  The structure which connected between the right and left wheel houses with the protective cover of the electric equipment is disclosed (refer patent document 1). The protective cover is formed in the shape of an inverted hat and is integrated with the rear cross member. The upper surface of the protective cover is joined to the wheel house via a wheel house upper surface mounting stay.

JP 2004-243882 A

  The noise in the 125 Hz band and the 160 Hz band generated when the vehicle travels increases as the panel vibration increases due to the skeleton vibration of the vehicle. Skeletal vibration is a natural mode generated by the vertical movement of the rear side member located under the wheel house, and a wheel house falling mode in the vehicle width direction exists as this natural mode. The panel vibration is increased by the resonance of the inner and outer plates of the vehicle due to the wheel house falling mode. In the hatchback vehicle, the area of the inner plate and the outer plate is large, so that noise increases. The inner plate is, for example, a roof side inner panel. The outer plate is, for example, a side member outer panel. As countermeasures against noise, setting of a polypropylene sheet, changing of the panel shape, and the like are conceivable, but these are related to the cost and design of the vehicle, and thus countermeasures are difficult.

  On the other hand, the above-described conventional example has a main object of reducing the number of parts by integrating the protective cover and the rear cross member, and noise in driving is not particularly taken into consideration. The wheel house upper surface mounting stay is attached not to the wheel house itself but to a suspension tower provided in the wheel house. This is because the attachment position of the protective cover to the suspension tower and the attachment position of the suspension in the suspension tower are brought close to increase the attachment rigidity of the suspension.

  In view of the above fact, an object of the present invention is to suppress the generation of noise from the rear of the vehicle during vehicle travel.

  The vehicle rear portion structure according to claim 1 includes a wheel house provided on the left and right of the vehicle rear portion, a cross member that extends in the vehicle width direction and connects the wheel houses, and a vehicle width direction of the wheel house and the cross member. And a support part that connects the upper surface part of the end part of the first part.

  In the vehicle rear structure according to claim 1, the left and right wheel houses are connected to each other by a cross member, and the upper surface portion of the end of the cross member in the vehicle width direction and the wheel house are connected to each other by a support portion. Yes. Since the force generated when the wheel house vibrates in the direction of falling in the vehicle width direction is received by the axial force of the cross member when the vehicle travels, the wheel house falling mode is suppressed, and the panel vibration of the vehicle is also suppressed. For this reason, generation | occurrence | production of the noise from the vehicle rear part at the time of vehicle travel can be suppressed.

  According to a second aspect of the present invention, in the vehicle rear portion structure according to the first aspect, the upper surface portion is coupled to the support portion at two or more locations.

  In the vehicle rear structure according to claim 2, since the upper surface portion of the cross member is coupled to the support portion at two or more locations, the wheel house falling mode is further suppressed, and the vehicle panel vibration is further suppressed. Is done. For this reason, generation | occurrence | production of the noise from the vehicle rear part at the time of vehicle travel can further be suppressed.

  According to a third aspect of the present invention, in the vehicle rear portion structure according to the first or second aspect, the cross member includes an upper member having the upper surface portion, and a lower member positioned on the vehicle lower side of the upper member. And an end of the lower member in the vehicle width direction is coupled to the wheel house.

  In the vehicle rear structure according to claim 3, since the upper member of the cross member is coupled to the wheel house via the support portion and the lower member is coupled to the wheel house, the falling mode of the wheel house is suppressed, and the vehicle Panel vibration is also suppressed. For this reason, generation | occurrence | production of the noise from the vehicle rear part at the time of vehicle travel can be suppressed further.

  As described above, according to the vehicle rear portion structure described in claim 1, an excellent effect is obtained in that generation of noise from the vehicle rear portion during vehicle travel can be suppressed.

  According to the vehicle rear portion structure described in claim 2, an excellent effect is obtained that generation of noise from the vehicle rear portion during vehicle traveling can be further suppressed.

  According to the vehicle rear portion structure of the third aspect, an excellent effect is obtained that the wheel house falling mode can be further suppressed.

1 to 5 relate to the first embodiment. FIG. 1 is a perspective view showing a vehicle rear structure in a vehicle skeleton. It is a disassembled perspective view which shows a vehicle rear part structure. It is a perspective view which shows a cross member. FIG. 4 is an enlarged cross-sectional view taken along arrow 4-4 in FIG. 3 showing a cross member. (A) It is a diagram which shows the relationship between a frequency and the vibration level of the vehicle width direction of a wheel house. (B) It is a diagram which shows the relationship between a frequency and sound pressure sensitivity (noise). It is a perspective view which shows the effect | action of a vehicle rear part structure. It is a top view which shows the vehicle rear part structure which concerns on 2nd Embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
[First Embodiment]
In FIG. 1, the vehicle rear portion structure S <b> 1 according to the present embodiment relates to the rear portion structure of the vehicle skeleton 10, and includes a wheel house 12, a cross member 14, and a support portion 16.

  In FIG. 2, the wheel house 12 is provided on the left and right of the rear part of the vehicle, and is configured by joining an inner panel 18 and an outer panel (not shown) in the vehicle width direction. In the inner panel 18, for example, the flange 18 </ b> C serves as a joint portion. The outer panel is provided outside the inner panel 18 in the vehicle width direction. The wheel house 12 in this embodiment specifically refers to the inner panel 18.

  In FIG. 2, the inner panel 18 has a vertical wall portion 18A, an outer peripheral portion 18B, and a flange 18C. The vertical wall portion 18A is formed in a substantially semicircular shape in a side view from the vehicle interior, and is located on the innermost side in the vehicle width direction of the inner panel 18. The outer peripheral portion 18B is bent from the outer peripheral edge of the vertical wall portion 18A outward in the vehicle width direction. The flange 18 </ b> C is bent from the outer side in the vehicle width direction of the outer peripheral portion 18 </ b> B to the outer side in the radial direction of the wheel house 12, and is located on the outermost side in the vehicle width direction of the inner panel 18.

  A mounting bracket 20 protruding inward in the vehicle width direction is provided at the lower portion of the vertical wall portion 18A. The mounting bracket 20 is formed in a plate shape. The mounting bracket 20 is formed with a through hole 20A that opens in the vehicle front-rear direction, and a nut (not shown) is fixed to the rear side of the through hole 20A. Further, the inner panel 18 is provided with a support portion 16 described later.

  2 and 3, the cross member 14 is a member that extends in the vehicle width direction and connects the wheel houses 12 (inner panels 18) to each other. The bending rigidity of the cross member 14 in the vehicle vertical direction is set larger than the bending rigidity in the vehicle front-rear direction. The bending rigidity in the vehicle vertical direction is the rigidity against bending with the vehicle longitudinal direction as the rotation axis. The bending rigidity in the vehicle front-rear direction is the rigidity against bending with the vehicle vertical direction as the rotation axis. 2 to 4, the cross member 14 has, for example, an upper member 24 and a lower member 26 that are integrated with each other in the vertical direction of the vehicle rather than the longitudinal direction of the vehicle. It is structured long. The upper member 24 is formed linearly in the vehicle width direction, and has, for example, a flat upper surface portion 22.

  The lower member 26 is located on the vehicle lower side of the upper member 24 and is bent convexly on the vehicle upper side. The upper member 24 and the lower member 26 are respectively located at the center and the end of the cross member 14 in the vehicle width direction. Are connected to each other. A through hole 28 for reducing the weight is formed between the center portion and the end portion of the cross member 14 in the vehicle width direction. The through hole 28 is formed in a substantially triangular shape penetrating in the vehicle front-rear direction between the upper member 24 and the lower member 26.

  A through hole 26 </ b> A that penetrates in the vehicle front-rear direction is formed at the end of the lower member 26 in the vehicle width direction. As shown in FIG. 2, the lower member is fastened to the through hole 26 </ b> A and the through hole 20 </ b> A of the mounting bracket 20 through a bolt 32 and a nut (not shown) provided in the mounting bracket 20. 26 is coupled to the wheel house 12 (inner panel 18). In the present embodiment, the lower member 26 is coupled to the front surface of the mounting bracket 20 on the vehicle.

  As shown in FIG. 4, for example, the cross member 14 is configured by joining a front panel 34, an upper panel 36 that constitutes the upper surface portion 22, a support panel 38, and a lower panel 40. These panels are each a metal panel, for example. For example, the front panel 34 is vertically disposed along the vehicle vertical direction, and the upper panel 36, the support panel 38, and the lower panel 40 are all disposed on the vehicle rear side of the front panel 34. The front panel of the upper panel 36 is joined to the front panel 34 and disposed substantially horizontally on the vehicle rear side.

  The support panel 38 is bonded to the rear surface of the front panel 34 at the lower bonding portion 38A, and is bonded to the lower surface of the upper panel 36 at the upper bonding portion 38B. The support panel 38 is supported by the upper panel 36. Between the joint portions 38A and 38B, there is an inclined portion 38C that does not contact any of the front panel 34 and the upper panel 36. As a result, the upper member 24 has a closed cross-sectional structure with a substantially right-angled cross section. In order to further increase the bending rigidity of the upper member 24, for example, a trapezoidal bead 34A that protrudes toward the rear of the vehicle and extends in the vehicle width direction is formed in a portion of the front panel 34 that constitutes the closed cross section. (See FIGS. 3 and 4).

  The gap 28 in the cross member 14 is, for example, a through hole formed in the front panel 34. A support panel 38 is disposed above the gap 28, and a lower panel 40 is disposed below the gap 28. The lower panel 40 is joined to the rear surface of the front panel 34. The lower panel 40 is formed with, for example, a trapezoidal bead 40 </ b> A that protrudes rearward of the vehicle and extends along the longitudinal direction of the lower member 26. As a result, the lower member 26 has a closed cross-sectional structure with a trapezoidal cross section.

  It is desirable that the cross-sectional secondary moment of the upper member 24 is substantially constant regardless of the position in the vehicle width direction. Specifically, it is desirable that the change in the centroid of the upper member 24 depending on the position of the upper member 24 in the vehicle width direction is, for example, within ± 10 mm in the vehicle longitudinal direction and the vehicle vertical direction.

  The cross member 14 is not limited to the one having the upper member 24 and the lower member 26 integrally, and the upper member 24 and the lower member 26 may be provided separately.

  In FIG. 2, the support portion 16 connects the wheel house 12 (inner panel 18) and the upper surface portion 22 at the end of the cross member 14 in the vehicle width direction. The support portion 16 is formed, for example, along the cross-sectional shape of the inner panel 18, and the upper end 16 </ b> A is joined to the flange 18 </ b> C of the inner panel 18, and the lower end 16 </ b> B is joined to the vertical wall portion 18 </ b> A of the inner panel 18. Yes. The position of the lower end 16B is on the vehicle front side and the vehicle upper side with respect to the mounting bracket 20.

  A projecting portion 16C that projects inward in the vehicle width direction is formed at the lower end 16B. The protrusion 16C is formed in an inverted U-shaped cross section, and two or more through holes 16D are formed. In the illustrated example, two through holes 16D are formed in series in the vehicle front-rear direction. Nuts (not shown) are respectively fixed to the positions corresponding to the through holes 16D on the lower surface of the protruding portion 16C.

  Two through holes 22 </ b> A corresponding to the arrangement of the through holes 16 </ b> D are also formed in the upper surface portion 22 of the cross member 14. The upper surface portion 22 at the end of the cross member 14 in the vehicle width direction is overlaid on the protruding portion 16C of the support portion 16. Two bolts 42 are passed through the through holes 22A and 16D from the upper side of the vehicle and fastened to nuts (not shown) on the lower surface of the projecting portion 16C, whereby the upper surface portion 22 at the end of the cross member 14 in the vehicle width direction. Are respectively coupled to the support 16.

(Function)
This embodiment is configured as described above, and the operation thereof will be described below. In FIG. 1, in the vehicle rear structure S <b> 1 according to the present embodiment, the force generated when the wheel house 12 vibrates in the direction of falling in the vehicle width direction during vehicle travel can be received by the axial force of the cross member 14. Thereby, the fall mode of the wheel house 12 is suppressed, and the panel vibration of the vehicle is also suppressed. For this reason, generation | occurrence | production of the noise from the vehicle rear part at the time of vehicle travel can be suppressed.

  This effect becomes remarkable by the following configuration. First, the upper surface portion 22 at the end of the cross member 14 in the vehicle width direction is coupled to the support portions 16 provided in the wheel house 12 at two or more locations, respectively, and the coupling rigidity is high. Is a point. Second, the upper member 24 of the cross member 14 is coupled to the wheel house 12 via the support portion 16, and the lower member 26 is coupled to the wheel house 12. Third, the bending rigidity of the cross member 14 in the vehicle vertical direction is set to be larger than the bending rigidity in the vehicle front-rear direction.

  FIG. 5 shows an example of the analysis result. FIG. 5A is a diagram showing the relationship between the frequency and the vibration level in the vehicle width direction of the wheel house. FIG. 5B is a diagram showing the relationship between frequency and sound pressure sensitivity (noise). 5A and 5B, a broken line indicates a comparative example that does not have the structure of the present embodiment, and a solid line indicates an example that has the structure of the present embodiment.

  As shown in FIG. 5A, the vibration level of the wheel house according to the example is significantly reduced at 125 to 160 Hz as compared with the comparative example. Accordingly, as shown in FIG. 5B, the noise level according to the embodiment is also significantly reduced at 125 to 160 Hz. That is, it can be seen that by suppressing the vibration level of the wheel house 12 and suppressing the skeletal vibration of the vehicle, the panel vibration of the vehicle panel can be suppressed and the generation of noise from the rear of the vehicle during vehicle travel can be suppressed.

  Further, by reinforcing the vehicle skeleton 10 with the cross member 14, the steering stability can be improved. The cross member 14 can be lighter than the conventional one.

[Second Embodiment]
In FIG. 6, in the vehicle rear structure S2 according to the present embodiment, a part of the connection point between the cross member 14 and the wheel house 12 is omitted, for example, one connection point on the right side of the vehicle is provided. Specifically, the upper surface portion 22 is coupled to the support portion 16 at one location (bolt 42) at the right end of the cross member 14 in the vehicle, and the lower member 26 is not coupled to the wheel house 12. The connection point of the upper surface part 22 is, for example, the vehicle rear side among the two through holes 22A (FIG. 3). As with the first embodiment, the end of the cross member 14 on the left side of the vehicle has two locations on the upper surface portion 22 and one location on the lower member 26, for a total of three locations. Therefore, the coupling rigidity between the end of the cross member 14 on the right side of the vehicle and the wheel house 12 on the right side of the vehicle is lower than the end of the cross member 14 on the left side of the vehicle and the wheel house 12 on the left side of the vehicle.

(Function)
This embodiment is configured as described above, and the operation thereof will be described below. In FIG. 6, in the vehicle rear structure S <b> 2 according to the present embodiment, the lower member 26 is not coupled to the wheel house 12 on the right side of the vehicle at the end portion on the right side of the cross member 14. In addition to this, the upper surface portion 22 is coupled to the support portion 16 at one position at the vehicle right end of the cross member 14. Accordingly, the lower member 26 can be deformed (vibrated) without being restrained by the wheel house 12 on the right side of the vehicle. Thereby, the bending deformation (vibration) of the upper member 24 in the vehicle front-rear direction can be excited.

  When the upper member 24 is deformed so as to bend in the vehicle front-rear direction, the entire length of the cross member 14 is shortened (in the directions of arrows A and B), so that the connecting point between the cross member 14 and the wheel house 12 on the right side of the vehicle is the vehicle width direction. Pulled on. As a result, when the wheel house 12 on the right side of the vehicle is about to fall outward in the vehicle width direction when the vehicle is traveling (direction of arrow C), the wheel member 12 is pulled back inward in the vehicle width direction due to the deformation of the cross member 14. Force acts. The wheel house 12 on the right side of the vehicle can be pulled back also when the wheel house 12 on the left side of the vehicle tends to fall in the direction of arrow D.

  As described above, in this embodiment, the cross member 14 is vibrated in the opposite phase to the wheel house 12 that vibrates in the vehicle width direction, and the force is applied in the opposite phase, thereby suppressing the falling mode of the wheel house 12. Yes. Thereby, the panel vibration of the vehicle is also suppressed, and the generation of noise from the rear of the vehicle during vehicle travel can be suppressed.

[Third Embodiment]
In FIG. 7, in the vehicle rear portion structure S3 according to the present embodiment, a cross member 44 is added on the vehicle front side of the cross member 14 according to the second embodiment. The configuration of the connecting point between the cross member 44 and the wheel house 12 is one connecting point on the left side of the vehicle as opposed to the cross member 14 having one connecting point on the right side of the vehicle.

  Specifically, at the end of the cross member 44 on the left side of the vehicle, the upper surface portion 22 is coupled to the support portion 16 at one location, and the other portions are not coupled to the wheel house 12. As with the first embodiment, the end of the cross member 44 on the right side of the vehicle has three locations, two on the upper surface 22 and one on the lower member 26. Therefore, the coupling rigidity between the left end of the vehicle of the cross member 44 and the wheel house 12 on the left side of the vehicle is lower than that of the cross member 44 on the right side of the vehicle and the wheel house 12 on the right side of the vehicle.

  Since other parts are the same as those in the first embodiment or the second embodiment, the same parts are denoted by the same reference numerals and the description thereof is omitted.

(Function)
This embodiment is configured as described above, and the operation thereof will be described below. In FIG. 7, in the vehicle rear structure S3 according to the present embodiment, the cross member 14 causes the wheel house 12 on the right side of the vehicle to fall to the outside in the vehicle width direction (arrow C direction) by pulling back in the arrow E direction. The falling mode of the wheel house 12 can be suppressed. Moreover, the cross member 44 can suppress the falling mode of the wheel house 12 by pulling back in the direction of the arrow F that the wheel house 12 on the left side of the vehicle is about to fall outside in the vehicle width direction (arrow D direction). it can. Thereby, the panel vibration of the vehicle is also suppressed, and the generation of noise from the rear of the vehicle during vehicle travel can be suppressed.

[Other Embodiments]
In the first embodiment, there are two places where the end portion of the cross member 14 in the vehicle width direction and the wheel house 12 are joined, but this may be joined at one place, or even three places or more. Good. Moreover, although the cross member 14 shall have the upper member 24 and the lower member 26, the structure of the cross member 14 is not restricted to this. Furthermore, although the bending rigidity in the vehicle vertical direction of the cross member 14 is set to be larger than the bending rigidity in the vehicle longitudinal direction, the magnitude relationship of the bending rigidity is not limited to this.

  As mentioned above, although an example of the embodiment of the present invention was explained, the present invention is not limited to the above, and besides the above, it can be implemented with various modifications without departing from the gist thereof. Of course.

DESCRIPTION OF SYMBOLS 10 Vehicle frame 12 Wheel house 14 Cross member 16 Support part 22 Upper surface part 24 Upper member 26 Lower member 44 Cross member S1 Vehicle rear structure S2 Vehicle rear structure S3 Vehicle rear structure

Claims (3)

Wheel houses provided on the left and right of the rear of the vehicle,
A cross member extending in the vehicle width direction and connecting the wheel houses;
A support portion that connects the wheel house and an upper surface portion of an end portion of the cross member in the vehicle width direction;
A vehicle rear structure having:   The vehicle rear portion structure according to claim 1, wherein the upper surface portion is coupled to the support portion at two or more locations. The cross member has an upper member having the upper surface portion, and a lower member located on the vehicle lower side of the upper member,
The vehicle rear portion structure according to claim 1 or 2, wherein an end of the lower member in the vehicle width direction is coupled to the wheel house.

Images