Suspension mounting structure

Abstract

The present invention provides a suspension mounting structure comprising: a side member extending in vehicle length direction; a suspension member disposed below the side member; and an arm secured to the suspension member at a first securing section and secured to the side member by means of a mounting bolt at a second securing section. The second securing section has a top wall, a bottom wall, a collar located between the top and bottom walls, and a vertical wall adjacent to the collar, the vertical wall having a top edge connected to the top wall and a bottom edge connected to the bottom wall. In a cross-section perpendicular to a given direction, the vertical wall is located between one end section and the other end section of the top wall, and between one end section and the other end section of the bottom wall.

Description

Suspension mounting structure

[0001] The present invention relates to a suspension mounting structure.

[0002] Patent Document 1 discloses a suspension mounting structure that includes a suspension link having a closed cross section that connects a side member and a suspension member. The suspension link is separated from the side member when a load is input from the front of the vehicle.

[0003] Patent No. 6696310

[0004] However, in Patent Document 1, when a load is input from the front of the vehicle, the suspension link having a closed cross section deforms, which increases the time it takes for the link to separate from the side member, and this can result in increased deceleration of the vehicle.

[0005] An object of the present invention is to provide a suspension mounting structure that can suppress an increase in deceleration of a vehicle when a load is input to the vehicle body from the front.

[0006] A suspension mounting structure according to one aspect of the present invention includes left and right side members extending in a vehicle longitudinal direction, a suspension member disposed below the side members, a first fixing portion fixed to the suspension members, and a second fixing portion fixed to the side members with a mounting bolt, and an arm extending in a predetermined direction from the first fixing portion to the second fixing portion in a plan view. The second fixing portion includes an upper wall, a lower wall, a collar disposed between the upper and lower walls and through which the mounting bolt is inserted, and a vertical wall disposed adjacent to the collar, the upper edge of which is connected to the upper wall and the lower edge of which is connected to the lower wall. In a cross section perpendicular to the predetermined direction, the vertical wall is disposed between one end and the other end of the upper wall and between one end and the other end of the lower wall.

[0007] According to a suspension mounting structure according to one aspect of the present invention, it is possible to suppress an increase in deceleration of the vehicle when a load is input to the vehicle body from the front.

[0008] Fig. 1 is a side view showing the front structure of a vehicle equipped with a suspension mounting structure according to an embodiment. Fig. 2 is a perspective view showing the structure of a suspension member according to an embodiment. Fig. 3A is a side view showing the structure of an arm according to an embodiment. Fig. 3B is a side view showing the structure of an arm according to an embodiment. Fig. 3C is a cross-sectional view of a main part of the structure of the arm according to an embodiment. Fig. 4 is a perspective view of the suspension mounting structure according to an embodiment. Fig. 5 is an exploded perspective view of the suspension mounting structure according to an embodiment. Fig. 6 is a schematic view showing a modified example of the suspension mounting structure according to an embodiment when a load is input to the vehicle body from the front.

[0009] A suspension mounting structure S mounted on a vehicle according to an embodiment will now be described with reference to the drawings. In each drawing, FW and BW indicate the front and rear in the vehicle longitudinal direction, respectively, UP indicates the upper side in the vehicle vertical direction, and LH and RH indicate the left and right sides in the vehicle width direction, respectively. In the following description, the front, front side, rear side, and rear side in the vehicle longitudinal direction, the upper side, upper side, lower side, and lower side in the vehicle vertical direction, and the left side, left side, right side, and right side in the vehicle width direction will be simply referred to as the front side, front side, rear side, rear side, upper side, upper side, lower side, lower side, left side, right side, and right side, respectively. Furthermore, components having the same functions as those already described will be designated by the same reference numerals, and their description will be omitted.

[0010] 1, the suspension mounting structure S includes left and right side members 11, 11 disposed on the vehicle body 1, a suspension member 21 disposed below the side members 11, 11, and arms 31, 31 provided on the suspension member 21 and having tip ends 34, 34 fixed to the side members 11, 11. The arms 31, 31 may also be called suspension links, suspension brackets, etc.

[0011] The side members 11 are skeletal structural members disposed on the left and right sides of the vehicle body 1. Each side member 11 has a front portion 12 extending in the longitudinal direction of the vehicle, an intermediate portion 13 connected to the rear of the front portion 12, a rear portion 14 connected to the rear of the intermediate portion 13, and a connecting portion 15 connected to the rear end of the rear portion 14.

[0012] The front ends of the front portions 12 are connected to a front bumper reinforcement 16 extending in the vehicle width direction. Tip ends 34 of arms 31 provided on suspension members 21 are fixed to the intermediate portions 13. The rear portions 14 extend rearward from the intermediate portions 13 while sloping downward. The connecting portions 15 are connected to the suspension members 21 (see FIG. 1).

[0013] A suspension member 21 is disposed below the side members 11. The suspension member 21 is a skeletal structural member extending in the front-rear direction and the vehicle width direction. The suspension member 21 has a suspension member rear portion 22 extending in the vehicle width direction, left and right side beams 23, 23, and a front cross beam 24 (see FIG. 2).

[0014] The suspension member rear portion 22 is disposed below the intermediate portions 13 and rear portions 14 of the side members 11 (see FIG. 1 ). Arm connecting portions 25, 25 to which arms 31 are connected are provided on the left and right sides of the front portion of the suspension member rear portion 22. Side member connecting portions 26, 26 to which connecting portions 15, 15 of the side members 11 are connected are provided on the left and right sides of the rear portion of the suspension member rear portion 22. Side beams 23, 23 extend forward from the front end of the suspension member rear portion 22 while sloping upward. Front ends of the side beams 23, 23 are connected via a front cross beam 24 extending in the vehicle width direction. Furthermore, the side beams 23, 23 are connected to the upper side members 11, 11, via support brackets 17, 17, respectively (see FIG. 2 ).

[0015] The arms 31 are members that connect the side members 11 and the suspension member 21 (see FIGS. 1 and 2). The arms 31 have main body portions 32 that are first fixed portions 36A fixed to the suspension member 21, horizontal portions 33 that extend horizontally from the main body portions 32, tip portions 34 that are second fixed portions 36B fixed to the side members 11, and vertical walls 37 that are reinforcing members. Below, the suspension mounting structure S will be described using the structure of the side member 11, suspension member 21, arm 31, etc. disposed on the left side of the vehicle body 1 as an example. The structures of the side member 11, suspension member 21, arm 31, etc. disposed on the right side of the vehicle body 1 are similar, so description thereof will be omitted.

[0016] The lower end of the main body portion 32, which is the first fixing portion 36A, is fixed to the arm connecting portion 25 by welding or the like. The main body portion 32 extends upward from the arm connecting portion 25 and connects to the horizontal portion 33. The horizontal portion 33 curves from the upper end of the main body portion 32, extends horizontally, and connects to the tip portion 34. In other words, the horizontal portion 33 is adjacent to the tip portion 34 and extends along a horizontal line L that passes through a mounting bolt BT (described below) that secures the tip portion 34. Note that the direction of the line L, which is a predetermined direction when viewed from the mounting bolt BT, may be parallel to the vehicle width direction or may face slightly forward relative to the vehicle width direction. The second fixing portion 36B is composed of the tip portion 34 and a portion of the horizontal portion 33, but may also be composed of only the tip portion 34.

[0017] The main body 32 and horizontal portion 33 are channel-shaped members with U-shaped open cross sections (see FIGS. 3B and 3C ). The open portion of the U-shape faces horizontally, perpendicular to the line L. The main body 32 has an inner wall 32A, which is one opposing wall of the U-shape, an outer wall 32B, which is the other opposing wall, and a side wall 32C, which is the bottom of the U-shape. Similarly, the horizontal portion 33 has an upper wall 33A, which is one opposing wall of the U-shape, a lower wall 33B, which is the other opposing wall, and a side wall 33C, which is the bottom of the U-shape. The inner wall 32A, outer wall 32B, and side wall 32C of the main body 32 are smoothly connected to the upper wall 33A, lower wall 33B, and side wall 33C of the horizontal portion 33, respectively.

[0018] The tip portion 34 is connected to the intermediate portion 13 of the side member 11. The tip portion 34 has an upper wall 33A and a lower wall 33B extending horizontally from the horizontal portion 33 toward the tip, an insertion hole 34A in the upper wall 33A, an insertion hole 34B in the lower wall 33B, and a collar 35 disposed between the upper wall 33A and the lower wall 33B. The tip portion 34 is fastened to the side member 11 with a nut NT by inserting a mounting bolt BT into the insertion holes 34A, 34B and the collar 35.

[0019] The side wall 33C of the horizontal portion 33 does not extend horizontally from the horizontal portion 33 to the tip portion 34 ( FIG. 3C ). That is, in a cross section perpendicular to the line L, the tip portion 34 does not have a structure corresponding to the side wall 33C. Therefore, in a cross section perpendicular to the line L, a gap is formed between the upper wall 33A and the lower wall 33B of the tip portion 34. Therefore, the tip portion 34 does not have a vertical wall 37 (described below) that is a reinforcing member connected to the upper wall 33A and the lower wall 33B (see FIG. 3C ).

[0020] The top wall 33A has a notch that serves as a first weak portion 38 at the tip of the insertion hole 34A. The bottom wall 33B has a notch that serves as a second weak portion 39 at the tip of the insertion hole 34B. The width of the notch of the second weak portion 39 of the bottom wall 33B is wider than the width of the notch of the first weak portion 38 of the top wall 33A. Therefore, the second weak portion 39 is configured to be weaker than the first weak portion 38 with respect to the input of a load. In addition, the bottom wall 33B has a plurality of cylindrical protrusions 34C for supporting the collar 35 around the tip side of the insertion hole 34B, through which the mounting bolt BT is inserted.

[0021] The second fixing portion 36B of the arm 31 has a vertical wall 37, which is a reinforcing member connected to the upper wall 33A and the lower wall 33B (see FIGS. 3A to 5). The vertical wall 37 has an upper edge 37A connected to the upper wall 33A, a lower edge 37B connected to the lower wall 33B, and a leading edge 37C adjacent to the collar 35. Furthermore, in a cross section perpendicular to the line L, the vertical wall 37 is disposed between the two horizontal ends 33A1 and 33A2 of the upper wall 33A and between the two horizontal ends 33B1 and 33B2 of the lower wall 33B. In other words, when viewed in a direction parallel to the line L, the vertical wall 37 is disposed inward of the two horizontal ends 33A1, 33A2, 33B1, and 33B2 of the upper wall 33A and the lower wall 33B (see FIG. 3B). Furthermore, when viewed in a direction parallel to the line L, the vertical wall 37 may be positioned so as to overlap the collar 35. Furthermore, when viewed in a direction parallel to the line L, the vertical wall 37 may be positioned so as to overlap the mounting bolt BT. The vertical wall 37 may have any shape and be positioned so long as its upper edge 37A is connected to the top wall 33A, its lower edge 37B is connected to the bottom wall 33B, its leading edge 37C is adjacent to the collar 35, and the vertical wall 37 has a portion located between the two ends 33A1 and 33A2 of the top wall 33A and between the two ends 33B1 and 33B2 of the bottom wall 33B in a cross section perpendicular to the line L. Therefore, a portion of the vertical wall 37 may be positioned in the main body portion 32 and connected to or adjacent to the inner wall 32A, outer wall 32B, and side wall 32C of the main body portion 32 (see FIG. 3A ). Alternatively, the vertical wall 37 may be positioned on a horizontal portion of the horizontal portion 33. In this case, in a cross section perpendicular to the line L, of one end 33A1 and the other end 33A2 of the top wall 33A in the horizontal direction, the other end 33A2 corresponds to the portion 33D between the top wall 33A and the side wall 33C (see FIG. 3B). Similarly, of one end 33B1 and the other end 33B2 of the bottom wall 33B in the horizontal direction, the other end 33B2 corresponds to the portion 33D between the bottom wall 33B and the side wall 33C (see FIG. 3B). Furthermore, the vertical wall 37 may be disposed across a portion of the horizontal portion 33 and a portion of the tip end 34.

[0022] Next, the operation of the suspension mounting structure S when a load is input to the vehicle body 1 from the front will be described. When a load is input to the vehicle body 1 from the front due to a collision or the like, as shown in FIG. 6 , the portion of the suspension member 21 between the side beam 23 and the suspension member rear portion 22 bends and deforms downward. That is, a rotational moment acts on the suspension member rear portion 22 in a direction that rotates the front end of the suspension member rear portion 22 downward around the side member connecting portion 26. As a result, the arm 31 provided in front of the suspension member rear portion 22 is pulled downward. The force acting on the arm 31 at this time is referred to as a tensile force hereinafter. Because the tip end 34 of the arm 31 is connected to the side member 11, the arm 31 tends to deform due to this tensile force. Here, the horizontal portion 33 of the arm 31 according to this embodiment has a vertical wall 37 whose upper edge 37A is connected to the upper surface wall 33A and whose lower edge 37B is connected to the lower surface wall 33B. The vertical wall 37 is disposed between two horizontal ends 33A1, 33A2 of the upper wall 33A and between two horizontal ends 33B1, 33B2 of the lower wall 33B. This provides the horizontal portion 33 with high rigidity. Therefore, deformation of the relative positions of the upper wall 33A and the lower wall 33B due to the tensile force is suppressed. Furthermore, the leading edge 37C of the vertical wall 37 is adjacent to the collar 35. In other words, at least the portion of the leading end 34 that includes the collar 35 does not include the vertical wall 37. Therefore, the rigidity of this portion of the leading end 34 is relatively lower than that of the horizontal portion 33 that includes the vertical wall 37. Therefore, the leading end 34, which has a relatively low rigidity, is significantly deformed by the tensile force. In other words, the tensile force is quickly transmitted to the leading end 34, which has a relatively low rigidity.

[0023] The deformation of the tip portion 34 will now be described. When a load greater than or equal to a predetermined value is applied to the tip portion 34, the mounting bolt BT falls out of the insertion holes 34A, 34B. Here, because the tip portion 34 deforms due to the rotational moment described above, the amount of deformation is greater in the upper wall 33A than in the lower wall 33B. Therefore, the mounting bolt BT falls out of the insertion hole 34A in the upper wall 33A before falling out of the insertion hole 34B in the lower wall 33B. That is, when a load greater than or equal to a predetermined value is applied to the insertion hole 34A in the upper wall 33A, the mounting bolt BT inserted into the insertion hole 34A deforms the first weak portion 38 at the tip outward. This deformation expands the diameter of the insertion hole 34A, widening the width of the notch in the first weak portion 38, causing the mounting bolt BT to fall out of the insertion hole 34A. Subsequently, when a load equal to or greater than a predetermined value is input to the insertion hole 34B of the lower wall 33B, the mounting bolt BT inserted through the insertion hole 34B deforms the second fragile portion 39 at its tip outward. This deformation expands the diameter of the insertion hole 34B, widening the width of the notch in the second fragile portion 39 and causing the mounting bolt BT to fall out of the insertion hole 34B. At this time, because the width of the notch in the second fragile portion 39 is wider than the width of the notch in the first fragile portion 38, the mounting bolt BT quickly falls out of the insertion hole 34B. In other words, after falling out of the insertion hole 34A, the mounting bolt BT is prevented from getting caught in the insertion hole 34A and being prevented from falling out. Therefore, the arm 31 is smoothly separated from the side member 11, shortening the time until separation and preventing the vehicle from decelerating too much.

[0024] (1) The suspension mounting structure S includes left and right side members 11 extending in the vehicle fore-and-aft direction, a suspension member 21 disposed below the side members 11, a first fixing portion 36A fixed to the suspension member 21, and a second fixing portion 36B fixed to the side member 11 by a mounting bolt BT, and an arm 31 extending in a predetermined direction, a straight line L, from the first fixing portion 36A to the second fixing portion 36B in a plan view. The second fixing portion 36B has an upper wall 33A, a lower wall 33B, a collar 35 disposed between the upper wall 33A and the lower wall 33B and through which the mounting bolt BT is inserted, and a vertical wall 37 disposed adjacent to the collar 35, the upper edge 37A of which is connected to the upper wall 33A and the lower edge 37B of which is connected to the lower wall 33B. In a cross section perpendicular to a straight line L, which is a predetermined direction, the vertical wall 37 is arranged between one end 33A1 and the other end 33A2 of the upper wall 33A, and between one end 33B1 and the other end 33B2 of the lower wall 33B.

[0025] When a load is input to the vehicle body 1 from the front, the suspension member 21 deforms downward. As a result, a force pulling downward acts on the arm 31 provided on the suspension member 21. At this time, the above-described configuration can suppress deformation of the relative position of the upper surface wall 33A and the lower surface wall 33B in response to the tensile force. As a result, the tensile force is quickly transmitted to the tip end 34 of the arm 31, causing the tip end 34 to fall off the side member 11. Therefore, the time until the arm 31 is separated from the side member 11 can be shortened compared to a case where this configuration is not provided, and an increase in deceleration of the vehicle can be suppressed.

[0026] (2) In the embodiment, the vertical wall 37 is disposed at a position overlapping the collar 35 when viewed in a direction parallel to the predetermined direction, i.e., the straight line L. With the above configuration, deformation of the relative positions of the upper wall 33A and the lower wall 33B can be further suppressed when a load is input to the vehicle body 1 from the front. Therefore, an increase in the deceleration of the vehicle can be further suppressed.

[0027] (3) Furthermore, in the embodiment, the vertical wall 37 is positioned so as to overlap the mounting bolt BT when viewed in a direction parallel to the predetermined direction, i.e., the straight line L. With the above configuration, deformation of the relative positions of the upper wall 33A and the lower wall 33B can be further suppressed when a load is input to the vehicle body 1 from the front. Therefore, an increase in the deceleration of the vehicle can be further suppressed.

[0028] (4) In the embodiment, the lower wall 33B has a plurality of cylindrical protrusions 34C around the insertion hole 34B of the mounting bolt BT that restrict movement of the collar 35. When a load is input to the vehicle body 1 from the front, the load of the collar 35 is applied to the periphery of the insertion hole 34B, expanding the diameter of the insertion hole 34B and prying it open. At this time, due to the above configuration, the collar 35 comes into even contact with the plurality of protrusions 34C around the insertion hole 34B, thereby suppressing load variation when expanding the diameter of the insertion hole 34B. Therefore, variation in the manner in which the arm 31 is separated from the side member 11 can be suppressed compared to when this configuration is not included.

[0029] (5) Furthermore, in the embodiment, the upper surface wall 33A has a first weak portion 38 at its tip, and the lower surface wall 33B has a second weak portion 39 at its tip that is weaker than the first weak portion 38. With the above configuration, when a load is input to the vehicle body 1 from the front and the tip portion 34 is deformed, the mounting bolt BT inserted through the insertion hole 34A can easily deform the first weak portion 38 provided at the tip outward. This deformation causes the insertion hole 34A to expand in diameter, widening the width of the notch in the first weak portion 38, causing the mounting bolt BT to fall out of the insertion hole 34A. Thereafter, the mounting bolt BT inserted through the insertion hole 34B deforms the second weak portion 39 provided at the tip outward. Because the width of the notch in the second weak portion 39 is formed wider than the width of the notch in the first weak portion 38, the mounting bolt BT quickly falls out of the insertion hole 34B. Therefore, the time required for the arm 31 to be separated from the side member 11 is shorter than when this configuration is not provided, and the deceleration of the vehicle can be prevented from increasing.

[0030] (6) In the embodiment, the vertical wall 37 extends from the leading edge 37C adjacent to the collar 35 to the first fixing portion 36A. With this configuration, when a load is input to the vehicle body 1 from the front, deformation of the relative position between the upper wall 33A and the lower wall 33B can be further suppressed compared to when the vertical wall 37 is provided only at a portion of the arm 31. Therefore, an increase in deceleration of the vehicle can be further suppressed.

[0031] The above-described embodiments are merely examples described to facilitate understanding of the invention. The technical scope of the invention is not limited to the specific technical matters disclosed in the above-described embodiments, but also includes various modifications, changes, alternative technologies, etc. that can be easily derived therefrom.

[0032] In the above embodiment, the vertical walls 37 are described as being smooth and parallel to the vertical direction, but the vertical walls 37 may have curved or uneven surfaces, or may be inclined relative to the vertical direction. Furthermore, the upper edge 37A of the vertical wall 37 and the upper surface wall 33A may be connected only at a portion, and similarly, the lower edge 37B of the vertical wall 37 and the lower surface wall 33B may be connected only at a portion. Furthermore, the leading edge 37C of the vertical wall 37 and the collar 35 may be adjacent only at a portion.

[0033] DESCRIPTION OF SYMBOLS 11 Side member 21 Suspension member 31 Arm 33A Upper wall 33A1 One end of upper wall 33A2 Other end of upper wall 33B Lower wall 33B1 One end of lower wall 33B2 Other end of lower wall 34B Insertion hole 34C Protrusion 35 Collar 36A First fixing portion 36B Second fixing portion 37 Vertical wall 37A Upper edge 37B Lower edge 37C Tip edge 38 First weak portion 39 Second weak portion BT Mounting bolt L Predetermined direction (straight line) S Suspension mounting structure

Claims

1. A suspension mounting structure comprising: left and right side members extending in a longitudinal direction of a vehicle; a suspension member arranged below the side members; and an arm having a first fixing portion fixed to the suspension members and a second fixing portion fixed to the side members by a mounting bolt, the arm extending in a predetermined direction from the first fixing portion to the second fixing portion in a plan view, wherein the second fixing portion has an upper wall, a lower wall, a collar arranged between the upper wall and the lower wall and through which the mounting bolt is inserted, and a vertical wall provided adjacent to the collar, the upper edge of which is connected to the upper wall and the lower edge of which is connected to the lower wall, wherein in a cross section perpendicular to the predetermined direction, the vertical wall is arranged between one end and the other end of the upper wall, and between one end and the other end of the lower wall.

2. A suspension mounting structure as set forth in claim 1, wherein said vertical wall is positioned so as to overlap said collar when viewed in a direction parallel to said predetermined direction.

3. A suspension mounting structure as set forth in claim 1, wherein said vertical wall is positioned so as to overlap said mounting bolt when viewed in a direction parallel to said predetermined direction.

4. A suspension mounting structure as claimed in any one of claims 1 to 3, wherein the lower wall has a plurality of cylindrical protrusions around the insertion hole of the mounting bolt to restrict movement of the collar.

5. A suspension mounting structure as set forth in claim 4, wherein said upper wall has a first weak portion at a tip thereof, and said lower wall has a second weak portion at a tip thereof which is weaker than said first weak portion.

6. The suspension mounting structure according to claim 1, wherein said vertical wall extends from a leading edge adjacent said collar to said first fixed portion.

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