JP3952011B2 - Subframe mounting structure - Google Patents

Description

  The present invention relates to a subframe mounting structure, and more particularly to a subframe mounting structure having a high mounting strength on the vehicle body side.

  An engine room is disposed in the front part of the vehicle body, and a pair of left and right side members and an extension member extend along the vehicle front-rear direction at the lower part of the engine room.

On the other hand, the subframe has a front end attached to the side member and a rear end attached to the extension member (see, for example, Patent Document 1).
JP-A-8-230717

  However, in the conventional example, in order to secure the mounting strength of the subframe, it is necessary to increase the plate thickness of the side member and the extension member or to select a material having high rigidity.

  Here, when the plate thickness is increased, the weight of the side member and the extension member increases, leading to an increase in the weight of the vehicle. If a material having high rigidity is selected, the cost increases.

  Accordingly, an object of the present invention is to provide a sub-frame mounting structure that can ensure mounting strength without increasing weight or increasing costs.

In order to achieve the above object, the sub-frame mounting structure according to the present invention is provided with a rear support portion at the rear end of the sub frame disposed on the lower side of the vehicle body, and rearward from above the rear support portion. the mounting member is provided toward, the mounting member has a first closed cross-section portion and a second closed cross-section portion is configured to closed cross as viewed from the side of the vehicle, said the upper side of the rear support portion a first closed cross-section portion arranged, the second closed cross-section portion on the rear side of the rear support part is arranged, together with the linking of these first closed cross-section portion and a second closed cross-section portion, the upper side of the mounting member by providing a cross section hat-shaped body member, an upper top and second closed cross-section portion of the first closed cross-section portion connected through a third closed cross-section portion, the side support portion after the sub-frame It is attached to the lower part of the first closed cross section.

  According to the attachment structure of the subframe according to the present invention, the rear end of the subframe is attached to the closed cross section, so that the attachment strength can be greatly improved. Even when the vehicle has a frontal collision and a collision load is input to the subframe from the front, the rear end of the subframe is reliably supported by the first closed cross section, and the subframe is moved rearward. The rear end of the subframe can be received at the second closed cross section. Therefore, a vehicle body member such as a dash panel does not protrude into the room even during a frontal collision of the vehicle.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First embodiment]
FIG. 1 is a bottom view of a front portion of a vehicle body to which a subframe mounting structure according to a first embodiment of the present invention is applied.

  A pair of left and right side members 3, 3 and extension members 5, 5 extend along the vehicle front-rear direction on the left and right sides of the vehicle body front portion 1, and between these side members 3, 3 and the extension members 5, 5. A substantially frame-shaped subframe 7 is disposed in the frame. Further, the front end 9 of the sub-frame 7 is attached to the side members 3 and 3 via a pair of left and right front support portions 11 and 11, and the rear end 13 is a pair of left and right rear support portions 15 and 15 as will be described later. The left and right extension members 5 and 5 are attached to an attachment member 17 that bridges the left and right extension members 5 and 15. In addition, in order to make the attachment state of the rear end 13 of the subframe 7 easy to understand, the plate 19 is shown by a virtual line.

  2 is an enlarged cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a perspective view showing a state in which the subframe 7 is attached to the attachment member in FIG.

  As shown in these drawings, a rear support portion 15 including a collar 21 and a fastening bolt 23 is provided at the rear end 13 of the subframe 7, and the rear support portion 15 is provided above and behind the rear support portion 15. Is provided with a mounting member 17 having a closed cross-sectional structure composed of a vehicle body member.

  The collar 21 is a substantially cylindrical member that is embedded in the rear end 13 of the subframe 7 and whose axial direction extends in the vertical direction. The upper end and the lower end slightly protrude upward and downward from the upper surface and the bottom surface of the rear end 13 of the subframe 7, and the inner side of the collar 21 is formed in an insertion hole 25 through which the fastening bolt 23 is inserted.

  The mounting member 17 is configured by joining an outer panel 27 disposed on the upper side and an inner panel 29 disposed on the lower side to each other, and includes a first closed cross-sectional portion 31, a second closed cross-sectional portion 33, and The fragile portions 35 are formed in communication with each other. The outer panel 27 has a front end formed on a front end wall 37 extending in the vertical and horizontal directions, an outer panel main body 39 extending from the upper end of the front end wall 37 along the diagonally rearward direction, and the rear end formed on the outer panel main body. The rear end wall 41 extends downward from the rear end edge 39. In addition, the inner panel 29 constitutes a lower part of the first closed cross-section 31 by extending rearward from the front vertical wall surface 43 joined to the front end wall 37 of the outer panel 27 and from the lower end of the front vertical wall surface 43. A front bottom wall surface 45; a connecting surface 47 extending from the rear end of the front bottom wall surface 45 along the outer panel main body 39; a rear vertical wall surface 49 suspended downward from the rear end of the connecting surface 47; The rear bottom wall surface 51 extends rearward from the rear end of the rear vertical wall surface 49 and is joined to the rear end wall 41 of the outer panel 27.

  The first closed cross-section portion 31 is a substantially triangular closed cross-section disposed above the rear support portion of the subframe 7, and the front portion of the first closed cross-section portion 31 is the front end wall of the outer panel main body 39. 37 and the front vertical wall surface 43 of the inner panel 29, the lower part is constituted by the front bottom wall surface 45 of the inner panel 29, and the rear part is constituted by the outer panel main body 39.

  A cylindrical bolt fixing portion 53 (projecting portion) that protrudes into the first closed cross-section portion 31 is formed integrally with the front bottom wall surface 45 on the front bottom wall surface 45.

  The second closed cross-section portion 33 is a substantially trapezoidal closed cross-section disposed behind the rear support portion 15 of the subframe 7, and the upper portion of the second closed cross-section portion 33 is constituted by an outer panel main body 39. The front part is composed of the rear vertical wall surface 49 of the inner panel 29, the lower part is composed of the rear bottom wall surface 51 of the inner panel 29, and the rear part is composed of the rear end wall 41 of the outer panel 27.

  The first closed cross-section portion 31 and the second closed cross-section portion 33 are connected via a fragile portion 35. The fragile portion 35 includes an outer panel main body 39 disposed on the upper side and a connecting surface 47 of the inner panel 29 disposed on the lower side, and the first closed cross-section portion 31 and the second closed cross-section portion 33. It is a site | part with which cross-sectional area was narrowed rather than.

  A dash panel 55 is joined to the upper end portion of the outer panel main body 39, and a floor panel 57 is joined to the rear end wall 41 of the outer panel 27.

  A plate 19 is disposed below the second closed cross-section portion 33 of the mounting member 17 and the rear end of the sub-frame 7, and the plate 19 is connected to the second closed section via fixing bolts 59 and fastening bolts 23. It is fixed to the rear bottom wall surface 51 of the cross section 33 and the bottom surface of the collar 21.

  The rear end upper portion 61 of the subframe 7 is formed on an inclined surface extending obliquely downward and rearward along the connecting surface 47 of the outer panel main body 39 and the inner panel 29.

  According to the embodiment of the present invention, since the first closed cross-section portion 31 and the second closed cross-section portion 33 are connected, the strength of the first closed cross-section portion 31 is increased. Since the rear support portion 15 of the sub-frame 7 is attached to the lower part of the sub-frame 7, the support strength of the sub-frame 7 can be increased.

  Further, even when the vehicle has a frontal collision and a collision load F (see FIG. 2) is input rearward from the subframe 7, it is possible to efficiently prevent the subframe 7 from moving rearward. it can.

  And since the 1st closed cross-section part 31 and the 2nd closed cross-section part 33 are connected via the weak part 35 which formed the cross-sectional area smaller than the 1st closed cross-section part 31 and the 2nd closed cross-section part 33, The rear end 13 of the sub-frame 7 can be brought into contact with the second closed cross section 33 without the cross section of the first closed cross section 31 changing so much. Thereby, the fastening bolt 23 is not broken by shear deformation, and the subframe 7 is not rotationally deformed toward the vehicle interior side.

[Second Embodiment]
Next, the sub-frame mounting structure according to the second embodiment will be described. The same reference numerals are given to the same parts as those in the first embodiment, and the description thereof will be omitted.

  FIG. 4 is a cross-sectional view showing a mounting structure of a subframe according to the second embodiment of the present invention, and FIG. 5 is a perspective view showing a state in which the subframe is mounted on the mounting member of FIG.

  In the present embodiment, as shown in these drawings, a rib 65 having a substantially triangular cross section is formed integrally with a bolt fixing portion 63 protruding into the first closed cross section 31. The rib 65 extends rearward from the rear portion of the outer peripheral surface of the bolt fixing portion 63, and the rear end edge 67 includes the rear end 63 a of the upper surface of the bolt fixing portion 63 and the front portion of the first closed cross-section portion 31. It is formed along a ridge line connecting the rear end 45a of the bottom wall surface 45.

  According to the present embodiment, the rear side of the bolt fixing portion 63 is supported by the rib 65, and the rear support portion 15 of the subframe 7 is fixed to the bolt fixing portion 63. Therefore, the vehicle causes a frontal collision, When a collision load F (see FIG. 4) is received from the subframe 7, the rearward movement of the fastening bolt 23 can be more reliably suppressed. That is, when a rear collision load F is input to the subframe 7, the fastening bolt 23 also moves rearward, but the bolt fixing portion 63 that fixes the upper end of the fastening bolt 23 is supported by the rib 65. Therefore, the upper end of the fastening bolt 23 can be supported. Furthermore, since the rear portion of the first closed cross-section portion 31 is disposed close to the rear end edge 67 of the rib 65, even if the subframe 7 moves backward, the rear end edge 67 of the rib 65 is It hits the outer panel 27 and effectively prevents the subframe 7 from moving backward.

[Third embodiment]
Next, the sub-frame mounting structure according to the third embodiment will be described. The same reference numerals are given to the same parts as those in the first and second embodiments, and the description thereof will be omitted.

  FIG. 6 is a cross-sectional view showing a mounting structure of a subframe according to the third embodiment of the present invention, and FIG. 7 is a perspective view showing a state in which the subframe is mounted on the mounting member of FIG.

  In the present embodiment, in addition to the second embodiment, a third closed cross-section portion 69 that bridges from the upper portion of the first closed cross-section portion 31 to the upper portion of the second closed cross-section portion 33 is provided. Specifically, by joining another outer panel 71 having a substantially hat-shaped cross section to the upper portion of the outer panel 27, the first closed cross-section portion 31, the fragile portion 35, and the second closed cross-section portion 33 are joined. A third closed cross-section 69 is formed on the rear obliquely upper side.

  According to the present embodiment, since the third closed cross-section portion 69 is provided from the first closed cross-section portion 31 to the second closed cross-section portion 33, the first closed cross-section portion 31 and the second closed cross-section portion 33 are connected. Strength can be improved. Therefore, the support rigidity of the rear end 13 of the subframe 7 can be further increased.

[Fourth Embodiment]
Next, a sub-frame mounting structure according to the fourth embodiment will be described. The same reference numerals are given to the same parts as those in the first to third embodiments, and the description thereof will be omitted.

  FIG. 8 is a cross-sectional view showing a mounting structure of a subframe according to the fourth embodiment of the present invention, and FIG. 9 is a perspective view showing a state in which the subframe is mounted on the mounting member of FIG.

  In this embodiment, as compared with the third embodiment, the first closed cross-section portion 73 and the second closed cross-section portion 75 are separated, and the fragile portion 77 is formed by a single inner panel 29 instead of the closed cross-section. ing.

  The outer panel is divided into a front outer panel 79 disposed on the front side and constituting the first closed cross-section portion 73, and a rear outer panel 81 disposed on the rear side and constituting the second closed cross-section portion 75. . The rear end 79a of the front outer panel 79 is joined to the rear end 45a of the front bottom wall surface 45 of the inner panel 29, and the front outer panel 79 that defines the rear portion of the first closed cross section 73 is It is arranged closer to the rear edge 67 of the rib 65 than in the second and third embodiments.

  Furthermore, the upper end 49 a of the rear vertical wall surface 49 that defines the second closed cross-section portion 75 is joined to the front end 81 a of the rear outer panel 81. The first closed cross-section portion 73 and the second closed cross-section portion 75 are connected to each other by the inner panel 29 disposed on the lower side, whereby the first closed cross-section portion 73 and the second closed cross-section portion 75 are connected to each other. Are arranged separately, and the fragile portion 77 is constituted by the inner panel 29 that connects the first closed cross-section portion 73 and the second closed cross-section portion 75.

  According to the present embodiment, the first closed cross-section portion 73 and the second closed cross-section portion 75 are separated from each other, and the fragile portion 77 is disposed across the first closed cross-section portion 73 and the second closed cross-section portion 75. Since the inner panel 29 is formed, the deformation of the cross-sectional shape of the first closed cross-sectional portion 73 at the time of a vehicle collision can be further suppressed. That is, since the strength of the fragile portion 77 is smaller than the fragile portion 35 due to the closed cross section of the first to third embodiments, when a collision load F (see FIG. 8) is input to the subframe 7 at the time of a vehicle collision, The rear end 13 of the subframe 7 is further easily rotationally deformed in a direction away from the indoor side.

FIG. 3 is a bottom view of the front portion of the vehicle body to which the subframe mounting structure according to the first embodiment of the present invention is applied. It is an expanded sectional view by the AA line of FIG. It is a perspective view which shows the state which attaches a sub-frame to the attachment member of FIG. It is sectional drawing which shows the attachment structure of the sub-frame by the 2nd Embodiment of this invention. It is a perspective view which shows the state which attaches a sub-frame to the attachment member of FIG. It is sectional drawing which shows the attachment structure of the sub-frame by the 3rd Embodiment of this invention. It is a perspective view which shows the state which attaches a sub-frame to the attachment member of FIG. It is sectional drawing which shows the attachment structure of the sub-frame by the 4th Embodiment of this invention. It is a perspective view which shows the state which attaches a sub-frame to the attachment member of FIG.

Explanation of symbols

7 ... Subframe 15 ... Rear support part 31, 73 ... First closed cross-section part 33, 75 ... Second closed cross-section part 35, 77 ... Fragile part 53, 63 ... Bolt fixing part (projecting part)
65 ... Rib 67 ... Rear edge 69 ... Third closed section 79 ... Front outer panel 81 ... Rear outer panel

Claims (5)

A rear support portion is provided at the rear end of the subframe disposed on the lower side of the vehicle body, and an attachment member is provided from above to the rear of the rear support portion. The attachment member includes a first closed cross-section portion and a second closed cross-section portion. and a closed cross-section portion is configured to closed cross as viewed from the side of the vehicle, the first closed cross-section portion arranged on the upper side of the rear support portion, the rearward side of the rear support portion first Two closed cross-section portions are arranged, and the first closed cross-section portion and the second closed cross-section portion are connected, and
By providing a cross section hat-shaped body member to the upper side of the attachment member, connecting the upper portion of the upper and second closed cross-section portion of the first closed cross-section portion through the third closed cross-section portion,
An attachment structure of a subframe, wherein a rear support portion of the subframe is attached to a lower portion of the first closed cross section.   The subframe mounting structure according to claim 1, wherein the first closed cross-section portion and the second closed cross-section portion are connected via a fragile portion.   Protruding portions projecting into the first closed cross section are provided, the rear side of the projecting portions is supported by ribs, the rear support portion of the subframe is fixed to the projecting portions, and the rear edge of the ribs The subframe mounting structure according to claim 1, wherein the rear portion of the first closed cross-section portion is disposed close to the rear portion. The first closed cross-section portion and the second closed cross-section portion are formed by connecting the inner panel to each other by joining the outer panel and the inner panel, and the fragile portion is formed by the first closed cross-section portion and the second closed cross-section portion. The sub-frame mounting structure according to claim 2 or 3 , wherein the cross-sectional area is smaller than that of the sub-frame. The first closed cross-section portion is formed by joining the front outer panel and the inner panel, and the second closed cross-section portion is formed by joining the rear outer panel and the inner panel. together to isolate the second closed cross-section portion to one another, the fragile portion, to claim 2 or 3, characterized in that consisted disposed the inner panel over the second closed cross-section portion of the first closed cross-section portion A sub-frame mounting structure characterized by what is described.

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