JP6458832B1 - Vehicle rear suspension structure - Google Patents

Abstract

In a rear suspension structure of a vehicle provided with a torsion beam type suspension, it is possible to effectively suppress damage to vehicle parts arranged close to the torsion beam with a simple configuration.
A rear suspension structure of a vehicle extends in the vehicle front-rear direction and supports a pair of left and right trailing arms that respectively support left and right rear wheels, and extends in the vehicle width direction and connects the two trailing arms. A torsion beam suspension 10 having a torsion beam 13 is provided, and the width of the torsion beam 13 in the longitudinal direction of the vehicle gradually decreases from the trailing arm 12 side toward the center of the vehicle. The trailing arm 12 includes the torsion beam 13. The bent portion 12d is provided between the joint portion 121 of the rear wheel and the mounting portion 12c of the rear wheel, and a part or all of the bent portion 12d is below the axis AC of the hub 52 of the axle unit 51. Has been placed.
[Selection] Figure 6

Description

  The present invention relates to a vehicle rear suspension structure.

  2. Description of the Related Art Conventionally, a rear suspension structure for an automobile includes a torsion beam type suspension having a pair of left and right trailing arms and a torsion beam for connecting the trailing arms.

  For example, in Patent Document 1, in a torsion beam type suspension including a torsion beam disposed close to the rear of a fuel tank, the cross section of the torsion beam has an open shape on the fuel tank side to suppress contact with the fuel tank flange portion. Is disclosed.

JP 2013-216206 A

  By the way, in the rear suspension structure of the vehicle, when a load is applied to the rear wheel, the load is transmitted to the torsion beam via the trailing arm, and there is a possibility that the torsion beam is broken and further peripheral parts such as the fuel tank are damaged.

  The present invention has been made in view of such a point, and an object of the present invention is to prevent damage to a torsion beam and vehicle components disposed in the vicinity of the torsion beam in a rear suspension structure of a vehicle having a torsion beam type suspension. The object is to enable effective suppression with a simple configuration.

The vehicle rear suspension structure disclosed herein includes a pair of left and right trailing arms that extend in the longitudinal direction of the vehicle and support the left and right rear wheels, respectively, and a torsion beam that extends in the vehicle width direction and connects the two trailing arms. A rear suspension structure of a vehicle including a torsion beam type suspension having a width of the torsion beam in the vehicle front-rear direction gradually decreases from the trailing arm side toward the vehicle center. A bent portion is provided between the joint portion of the torsion beam and the mounting portion of the rear wheel, and a part or all of the bent portion is disposed below the center axis of the rear wheel, and the tray The width in the vehicle width direction on the rear side of the bent portion of the ring arm is the bent portion of the trailing arm. It is larger than the width of the vehicle width direction in front of the.

  In the torsion beam suspension, when a torsion beam shape that gradually decreases from the side of the vehicle toward the center is adopted, excessive external force (hereinafter referred to as “side collision”) is applied to the rear wheel from the outside of the vehicle to the inside due to, for example, a side collision of the vehicle. When the load is applied, an excessive load is applied to the suspension, and the thinnest portion of the torsion beam located at the center of the vehicle may be bent or broken toward the front of the vehicle. If it does so, there exists a possibility of leading to the damage of the other vehicle components arrange | positioned near the front of the torsion beam.

  According to the above configuration, the bent portion is provided between the junction with the torsion beam and the mounting portion of the rear wheel on the trailing arm, and a part or all of the bent portion is below the center axis of the rear wheel. Due to the arrangement, when a side impact load acts on the rear wheel, a twisting force is generated in the trailing arm, and a twist is generated in the bent portion. Then, the side impact load is suppressed from acting on the torsion beam due to the twisting or cutting of the bent portion, and the torsion beam can be prevented from being bent or bent. Thus, damage to peripheral parts can be suppressed.

Further , the width in the vehicle width direction on the rear side of the bent portion of the trailing arm is larger than the width in the vehicle width direction on the front side of the bent portion of the trailing arm.

  According to this configuration, from the viewpoint of ensuring supportability of the rear wheel, the bent portion of the trailing arm is thicker at the rear and the front is thinner, so that when the side impact load is applied, the bent portion The torsion of the torsion beam can be prevented from being bent and bent.

  Moreover, it is preferable that the said bending part is provided with the recessed part formed in the vehicle width direction inner side of the said trailing arm.

  According to this configuration, since the bent portion includes the concave portion, stress concentrates on the bent portion when a side collision load is input, and the twist of the bent portion is promoted. Thus, the torsion beam can be prevented from being bent or bent.

  And a pair of left and right spring seats arranged so as to span the torsion beam and the trailing arm at a corner formed on the inner rear side of the joint between the torsion beam and the trailing arm. It is preferable that the torsion beam is provided with an inclined surface inclined toward the front center side from the rear on the joint portion side, and the spring seat is connected to the inclined surface.

  When a side impact load acts on the rear wheel, the side impact load can be transmitted to the torsion beam via the spring seat. According to this configuration, since the inclined surface is formed on the torsion beam and the spring seat is connected to the inclined surface, even if a side collision load occurs, the spring seat is peeled off, and the load transmitted to the torsion beam is reduced. be able to. In this way, bending and bending of the torsion beam can be suppressed.

  Preferably, an extension portion is formed at the front end of the spring seat so as to extend upward in the center along the inclined surface as it goes inward in the vehicle width direction.

  According to this structure, the load which acts on a torsion beam via a spring seat can be reduced, and the torsion beam can be prevented from being bent or bent.

  The rear wheel is supported on the outside of the trailing arm via a mounting bracket fixed to the mounting portion, and the mounting bracket moves the trailing arm from the outside to the inside of the trailing arm. It is preferable to provide an arm portion that extends so as to be held.

  According to this configuration, when the mounting bracket has an arm portion extending so as to hold the trailing arm, when a side collision load acts on the rear wheel, the rear portion of the trailing arm is bent. The side impact load acts on the whole, and the bending of the bent portion can be promoted.

  More preferably, each of the trailing arms includes an inner member disposed on the inner side in the vehicle width direction, and an outer member joined to the inner member and disposed on the outer side in the vehicle width direction. The arm portion extends from the outer member to the inner member.

  According to this configuration, since the rear wheel is supported on the outer member side, the side impact load acting on the outer member can be reliably transmitted to the inner member via the arm portion.

  And it is preferable that the thickness of the said outer member is larger than the thickness of the said inner member.

  According to this configuration, by making the thickness of the outer member larger than the thickness of the inner member, it is possible to suppress an increase in the weight of the rear portion of the vehicle while increasing the support rigidity of the outer member with respect to the rear wheel. In addition, by reducing the thickness of the inner member, the inner member becomes less rigid, promotes twisting and bending at the bent portion, and can suppress bending at an unintended portion other than the bent portion.

In a preferred embodiment, a fuel tank is disposed close to the front side of the torsion beam. If the layout in which the fuel tank is arranged close to the front side of the torsion beam is employed, the fuel tank may be damaged when the torsion beam is broken, causing a serious accident such as fuel leakage. According to this configuration, when an external force is applied to the rear wheel from the side of the vehicle, it is possible to prevent the torsion beam from being bent. Therefore, even if the fuel tank is arranged in front of the torsion beam, it is caused by the torsion beam being bent. Damage to the fuel tank can be prevented.

The vehicle rear suspension structure disclosed herein includes a pair of left and right trailing arms that extend in the vehicle front-rear direction and supports the left and right rear wheels, respectively, and a torsion beam that extends in the vehicle width direction and connects the two trailing arms. A rear suspension structure of the vehicle, wherein the torsion beam has a width in the vehicle front-rear direction that gradually decreases from the trailing arm side toward the vehicle center. A bent portion is provided between the joint portion of the torsion beam and the mounting portion of the rear wheel, and a part or all of the bent portion is disposed below the central axis of the rear wheel, The rear wheel is supported outside the trailing arm via a mounting bracket fixed to the mounting portion. The mounting bracket includes an arm portion extending so as to hold the trailing arm from the outside to the inside of the trailing arm, and each trailing arm is disposed on the inner side in the vehicle width direction. An inner member and an outer member joined to the inner member and disposed on the outer side in the vehicle width direction, and an arm portion of the mounting bracket extends from the outer member to the inner member. And the thickness of the outer member is larger than the thickness of the inner member.

  As described above, according to the present invention, the bent portion is provided between the junction with the torsion beam on the trailing arm and the mounting portion of the rear wheel, and a part or all of the bent portion is the central axis of the rear wheel. By being arranged so as to be further downward, when a side collision load is applied to the rear wheel, a twisting force is generated in the trailing arm, and a twist is generated in the bent portion. Then, the side impact load is suppressed from acting on the torsion beam due to the twisting and cutting of the bent portion, and the torsion beam can be prevented from being bent or bent. Thus, damage to peripheral parts can be suppressed.

1 is a schematic plan view showing a suspension structure according to Embodiment 1. FIG. It is a schematic bottom view of the suspension structure of FIG. FIG. 3 is an end view taken along line III-III in FIG. 1. FIG. 2 is an enlarged view of a left side portion of the suspension structure of FIG. 1. FIG. 5 is a perspective view of the left part of the suspension structure of FIG. FIG. 5 is a left side view of the left part of the suspension structure of FIG. 4 as viewed from the left side. It is an end view in the VII-VII line of FIG. It is an end view in the VIII-VIII line of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its application.

<Vehicle rear suspension structure>
FIG. 1 shows a rear suspension structure S (hereinafter referred to as “suspension structure S”) of a vehicle according to a first embodiment. The suspension structure S includes a torsion beam suspension 10 (hereinafter referred to as “suspension 10”). A vehicle to which the suspension structure S according to the first embodiment is applied is a vehicle such as a front engine front drive type (FF type) automobile, and the front wheels are driving wheels and the rear wheels are driven wheels.

<Direction>
In this specification, the direction is based on the traveling direction of the vehicle and the direction horizontal to the road surface. That is, as shown in FIG. 1, the “vehicle longitudinal direction” refers to the front side and the rear side of the traveling direction of the vehicle, and may be simply referred to as “front-rear direction”. Further, as shown in FIG. 1, the “left-right direction” is a direction parallel to the direction horizontal to the road surface and perpendicular to the front-rear direction, and may be referred to as “vehicle width direction”. The “vertical direction” is a direction perpendicular to the paper surface of FIG. 1, that is, a direction perpendicular to the front-rear direction and the left-right direction, and a direction perpendicular to the road surface.

<Suspension>
The suspension 10 disposed at the rear of the vehicle body of the vehicle extends in the front-rear direction and supports a pair of left and right trailing arms 12 that respectively support the left and right rear wheels, and extends in the vehicle width direction and connects both trailing arms 12. And a torsion beam 13.

<Torsion beam>
As shown in FIGS. 2 and 3, the torsion beam 13 has a cross-sectional shape that is a closed cross-section and an irregular cross-section, for example, by pressing a middle portion in the longitudinal direction of the lower portion of the hollow round pipe upward from the lower side. It is shaped to make a shape. Specifically, the torsion beam end portions 13a on both sides in the longitudinal direction of the torsion beam 13 are each formed to have a substantially rectangular cross section obtained by slightly pressing and deforming the wall surface from the original circular cross section of the hollow round pipe. The torsion beam 13 is formed such that the pressure deformation of the lower portion of the hollow round pipe increases from the torsion beam end portion 13a toward the torsion beam center portion 13b in the center in the longitudinal direction. As shown in FIG. 3, the opening is formed in a substantially square shape located on the lower side. As shown in FIGS. 1 and 2, the width in the front-rear direction of the torsion beam 13 gradually decreases from the torsion beam end 13 a on the trailing arm 12 side toward the torsion beam center 13 b in the center of the vehicle. 13b is the thinnest. Thus, by changing the cross-sectional shape greatly from the torsion beam central portion 13b to the torsion beam end portion 13a of the torsion beam 13, it is possible to achieve both torsional rigidity and bending strength.

  The torsion beam end portion 13a of the torsion beam 13 formed as described above has an inclined surface 13c as shown in FIGS. The inclined surface 13c is formed from the junction 121 side, that is, the torsion beam end 13a side toward the torsion beam central portion 13b, and is a surface inclined from the rear toward the front central side.

  As shown in FIG. 1, the torsion beam end portion 13 a is welded to the vehicle inner side of the front portion of the trailing arm 12 to form a joint portion 121. Therefore, in other words, the inclined surface 13 c is formed on the junction 121 side of the torsion beam 13.

  As shown in FIGS. 1 to 4, other vehicle parts are arranged around the torsion beam 13. In particular, in the present embodiment, the fuel tank F is disposed close to the front of the torsion beam 13.

<Trailing arm>
Hereinafter, a detailed configuration of the main components attached to the trailing arm 12 and the trailing arm 12 other than the torsion beam 13 will be described. In addition, since the suspension structure S according to the present embodiment is configured to be bilaterally symmetrical, in the following description, the configuration of the components attached to the left trailing arm 12 and the left trailing arm 12 will be mainly described. Detailed description of the right trailing arm 12 and the like will be omitted.

-Shape of trailing arm-
As shown in FIG. 4, the trailing arm 12 includes a front portion 12 a having a joint portion 121 with the torsion beam 13 and a rear portion 12 b including a mounting portion 12 c to which a rear wheel (not shown) is attached. A bent portion 12d is formed between the joint portion 121 and the mounting portion 12c on the trailing arm 12 as will be described later. For convenience, the front side of the bent portion 12d is the front portion 12a, and the rear side is the rear portion. 12b.

  The front portion 12a of the trailing arm 12 has a curved shape that is convex toward the right side (that is, the inside in the vehicle width direction) in plan view so as to avoid a rear wheel (not shown) attached to the attachment portion 12c. . Specifically, the front portion 12a of the trailing arm 12 is located on the rightmost side (that is, on the inner side in the vehicle width direction), that is, the middle portion in the front-rear direction, that is, the portion where the junction 121 with the torsion beam 13 is formed. From there, it is curved so as to be located on the left side as it approaches the front side end of the front part 12a and the rear side end of the front part 12a. Further, the front portion 12a has the rear end portion of the front portion 12a located on the left side of the front end portion of the front portion 12a. And the rear part 12b of the trailing arm 12 has a shape inclined to the left side as it goes to the rear side.

  As shown in FIG. 4, the width of the front portion 12a of the trailing arm 12 in the vehicle width direction gradually increases from the front end of the front portion 12a toward the rear end of the front portion 12a. It has a different shape. On the other hand, the rear portion 12b of the trailing arm 12 extends from the front end portion of the rear portion 12b toward the rear side of the rear portion 12b with a substantially uniform width in the vehicle width direction around the attachment portion 12c. And it has the shape where the width | variety of a vehicle width direction becomes large in the vicinity part of the rear side end of the rear part 12b rather than the other part of the said rear part 12b. According to this configuration, the rear wheel 12b can be thickened to ensure the supportability of the rear wheel, and the front part 12a can be thinned to reduce the weight of the rear part of the vehicle.

  As shown in FIG. 6, the trailing arm 12 is formed so as to extend rearward substantially horizontally from the front portion 12a to the bent portion 12d in the left side view. The trailing arm 12 is formed so as to be inclined from the bent portion 12d to the rear portion 12b so that the rear is lowered downward.

-Inner panel and outer panel-
As shown in FIGS. 1, 4, 5, and 7, the trailing arm 12 in the present embodiment is divided into left and right parts in the middle portion in the vehicle width direction, and is arranged on the right side, that is, the inner side in the vehicle width direction. The inner panel 20 (inner member) is provided, and the outer panel 30 (outer member) disposed on the left side, that is, on the outer side in the vehicle width direction. As shown in FIG. 7, the inner panel 20 and the outer panel 30 each have a U-shaped cross section and are joined by welding or the like with the U-shaped openings facing each other in the vehicle width direction. It is comprised so that a closed cross-sectional shape may be made over it. Each of the inner panel 20 and the outer panel 30 is an integrally molded product formed by, for example, pressing a steel plate. In addition, from the viewpoint of preventing electrolytic corrosion due to welding between the inner panel 20 and the outer panel 30, the inner panel 20 and the outer panel 30 are preferably made of the same material.

  As shown in FIG. 7, the thickness of the outer panel 30 is configured to be larger than the thickness of the inner panel 20 over the entire trailing arm 12. According to this configuration, the inner panel 20 is thinner than the outer panel 30 while increasing the support rigidity of the outer panel 30 with respect to the rear wheel, and thus an increase in the weight of the rear portion of the vehicle can be suppressed.

  Further, as shown in FIG. 7, the inner panel 20 and the outer panel 30 are slightly overlapped in the upper and lower portions so that the sectional shape of the trailing arm 12 becomes a closed sectional shape, in other words, The outer panel 30 is joined to each other by welding in a state where the outer panel 30 is fitted into the opening of the inner panel 20. Thereby, even if a load in the vertical direction is input to one of the inner panel 20 and the outer panel 30, the bonding between the inner panel 20 and the outer panel 30 is difficult to be released. In FIG. 7, the outer panel 30 is configured to fit into the opening of the inner panel 20, but the inner panel 20 may be configured to fit into the opening of the outer panel 30. Moreover, even if the inner side panel 20 and the outer side panel 30 are joined in the state which each upper part and the lower part faced in the state which does not mutually overlap in the upper part and the lower part from a viewpoint of weight reduction of a vehicle rear part. Good.

  The joint 121 between the torsion beam 13 and the trailing arm 12 described above is formed on the inner panel 20 side of the front portion 12a. That is, the torsion beam end portion 13a is welded to the inner panel 20 of the front portion 12a.

-Spring seat-
As shown in FIG. 1, a pair of left and right spring seats 16 are placed at corner portions formed on the inner rear side of the joint 121 between the torsion beam 13 and the trailing arm 12 so as to be spanned between the torsion beam 13 and the trailing arm 12. Is provided.

  4 and 5, the spring seat 16 is flat and has a substantially rectangular shape in plan view, and is smoothly connected to the front side of the bottom wall portion 16a and inclined upward. A widened transition portion 16b, an extension portion 16d that is smoothly connected to the front side and the right side of the transition portion 16b, and extends along the inclined surface 13c of the torsion beam 13, and a rear edge and a right edge of the bottom wall portion 16a , And a flange portion 16c formed so as to rise smoothly upward along the right edge of the transition portion 16b, and a spring attachment portion for attaching a coil spring (not shown) provided at substantially the center of the bottom wall portion 16a. 16e.

  The spring seat 16 is an integrally formed product formed by, for example, press forming a steel plate. The bottom wall portion 16a of the spring seat 16 and the left end portion of the flange portion 16c are welded from the position where the bent portion 12d of the inner panel 20 of the trailing arm 12 is formed to the rear portion 12b.

  Further, the front end of the spring seat 16, that is, the extending portion 16d, is formed so as to extend upward in the center of the vehicle along the inclined surface 13c toward the inner side in the vehicle width direction, and as described above, on the inclined surface 13c of the torsion beam 13. Connected and fixed by welding.

-Axle bracket-
As shown in FIG. 4, an axle bracket 15 (mounting bracket) for supporting a rear wheel (not shown) is fixed to the mounting portion 12c in the rear portion 12b of the trailing arm 12. An axle unit 51 as a rear wheel support unit is connected to the axle bracket 15 so as to protrude to the left side, that is, toward the outside in the vehicle width direction, and the rear wheel is connected to the axle unit 51.

  As shown in FIG. 4, the axle bracket 15 is formed by bending, for example, a metal plate so as to be substantially U-shaped in a plan view, and as shown in FIGS. A front side surface portion 15a extending in the vertical direction from an equivalent height position to a position higher than the upper portion of the trailing arm 12, and a vertical range spaced apart from the front side surface portion 15a to the rear side and similar to the front side surface portion 15a And a rear side surface portion 15b that connects the left side end portion of the front side surface portion 15a and the left side end portion of the rear side surface portion 15b. As shown in FIG. 5, the front side surface portion 15 a and the rear side surface portion 15 b of the axle bracket 15 are notched in a U-shape so as to follow the outer periphery of the outer panel 30 as shown in FIG. 5. A cutout portion 15f is formed. The axle bracket 15 is fixed to the outer panel 30 by arranging the notch portion 15f along the outer periphery of the outer panel 30 and then welding the front side surface portion 15a and the rear side surface portion 15b to the outer periphery of the outer panel 30 respectively. Is done.

  Further, as shown in FIG. 5, the axle bracket 15 is caused by a load in the front-rear direction on a portion surrounded by the front side surface portion 15 a, the rear side surface portion 15 b, the outer side surface portion 15 c, and the upper portion of the outer panel 30. A first auxiliary member 15d for preventing the deformation is provided. The peripheral edge portion of the first auxiliary member 15 d is welded to the front side surface portion 15 a, the rear side surface portion 15 b and the outer side surface portion 15 c of the axle bracket 15, and the upper portion of the outer panel 30.

  A second auxiliary member 15e (arm portion) extending in the vehicle width direction is joined to the front side surface portion 15a of the axle bracket 15 so as to hold the trailing arm 12 from the outside to the inside of the trailing arm 12. . The second auxiliary member 15 e is formed so as to extend from the upper part of the outer panel 30 to the upper part of the inner panel 20, and the upper part of the outer panel 30, the upper part of the inner panel 20, and the front side surface part of the axle bracket 15. 15a is welded to each. By providing the second auxiliary member 15e, the attachment rigidity of the axle bracket 15 to the trailing arm 12 can be improved.

-Axle unit-
As shown in FIGS. 4, 5, and 7, the axle unit 51 includes a hub 52 to which a rear wheel (not shown) is attached, and a housing 53 that houses a shaft portion 52 b of the hub 52. ing. As shown in FIG. 7, a ball bearing is formed by the shaft portion 52b of the hub 52, the housing 53, and the ball 54, whereby the hub 52 is rotatable. A housing flange portion 53a is provided on the right side portion of the housing 53, and the housing flange portion 53a is disposed on a portion of the outer side surface portion 15c of the axle bracket 15 above the outer panel 30 in the fastening member 100 (FIG. 5). Attached). Thus, the axle unit 51 is attached to the axle bracket 15. In a state where the axle unit 51 is attached to the axle bracket 15, the axle unit 51 protrudes toward the left side, and the axis AC (the center axis of the rear wheel) of the hub 52 of the axle unit 51 coincides with the vehicle width direction. It is like that.

  The left portion of the hub 52 forms a hub flange 52 a that widens outward in the radial direction of the hub 52, and the rear wheel is fastened to the hub flange 52 a of the hub 52 by fastening bolts 101. Thus, the rear wheel is supported on the rear portion of the outer panel 30 via the axle unit 51 and the axle bracket 15.

-Suspension bush and damper-
As shown in FIGS. 1 and 4, a suspension bush 14 for connecting the trailing arm 12 to the front end of the front portion 12 a of the trailing arm 12 so as to be swingable in the vertical direction with respect to the vehicle body of the vehicle. Is fixed.

  As shown in FIG. 5, a damper (not shown) for absorbing a repulsive load transmitted from the road surface via the rear wheel is provided at a portion of the trailing arm 12 on the rear side of the spring seat 16. It is attached via a damper bracket 70.

  Although not described here, various components are attached to the trailing arm 12 as necessary in addition to the above-described components.

-Bending part of trailing arm-
Here, as shown in FIGS. 4 to 6, the suspension structure S according to the present embodiment is on the trailing arm 12 and between the joint portion 121 of the torsion beam 13 and the mounting portion 12 c of the rear wheel. And a bent portion 12d formed behind the joint portion 121 and in front of the attachment portion 12c.

  5 and 6, the bent portion 12d is formed on the left side of the trailing arm 12, that is, on the outer side in the vehicle width direction, and on the right side of the trailing arm 12, that is, on the inner side in the vehicle width direction. It is comprised by the made inner side recessed part 25 (recessed part). In other words, the outer recess 35 is a recess formed in the outer panel 30, and the inner recess 25 is a recess formed in the inner panel 20.

  As shown in FIG. 6, a straight line AC1 passing through the axis AC of the hub 52 and extending in the horizontal direction is considered. In the left side view, the outer recessed portion 35 of the bent portion 12d is configured to be disposed below the straight line AC1. In other words, as described above, the rear portion 12b of the trailing arm 12 is inclined so as to be lowered downward, and the axle unit 51 has an axis AC that is the center of the rear portion 12b of the trailing arm 12 as a center. Since it arrange | positions so that it may come to the upper side, the outer side recessed part 35 is arrange | positioned below the axial center AC. Although not shown, as can be seen from FIG. 6, the inner concave portion 25 of the bent portion 12d is also arranged below the straight line AC1.

  When a side impact load is applied to a vehicle including the suspension structure S according to the present embodiment, as shown by a white arrow in FIG. 7, from the left to the right with respect to the axis AC, that is, from the outside of the vehicle toward the inside. Side impact load is input. As a result, the axial center AC is disposed above the trailing arm 12 as shown in FIGS. 6 and 7, and therefore, as shown by the solid line arrow in FIG. A rotational force is generated such that the unit 51 rotates in the circumferential direction.

  When the bent portion 12d is not formed, the side impact load acts on the torsion beam 13 and may cause deformation such as bending or bending at the torsion beam central portion 13b. On the other hand, in the present embodiment, when the bending portion 12d is formed between the joint portion 121 and the attachment portion 12c and below the axis AC, a rotational force is generated behind the bending portion 12d. In addition, it is possible to prevent the side impact load from reaching the torsion beam 13 due to deformation such as twisting, bending, and eventually cutting at the bent portion 12d. Thus, since the torsion beam 13 can be prevented from being bent or bent, it is possible to suppress damage to the vehicle components disposed in the vicinity of the torsion beam 13 such as breakage of the fuel tank F.

  The configuration of the bent portion 12d is not particularly limited, and for example, any one of the outer concave portion 35 and the inner concave portion 25 may be provided. Moreover, it is good also as a structure which provides not only the outer side recessed part 35 and the inner side recessed part 25 but a several recessed part further in the circumferential direction of the vehicle width direction of the trailing arm 12, and a recessed part (for example, circumferential direction all periphery) It is also possible to provide a structure in which a groove portion extending over the same is provided.

  In the present embodiment, since the thickness of the inner panel 20 is smaller than the thickness of the outer panel 30, the inner panel 20 is less rigid than the outer panel 30. Thereby, by providing the inner concave portion 25, it is possible to promote twisting and bending at the bent portion 12d and to suppress deformation such as twisting and bending at an unintended portion other than the bent portion 12d.

  Further, as described above, the width in the vehicle width direction at the rear portion 12b of the trailing arm 12 is larger than the width in the vehicle width direction at the front portion 12a of the trailing arm 12 (see, for example, FIG. 4). According to this configuration, as described above, the increase in the weight of the rear portion of the vehicle is suppressed while ensuring the support of the rear wheel, and the front portion of the bent portion 12d is thinner than the rear portion, so that the axial center AC is reduced. When a side impact load is applied, twisting at the bent portion 12d can be promoted.

  Further, as described above, the spring seat 16 is provided on the inner rear side of the joint 121 between the torsion beam 13 and the trailing arm 12, but when a side impact load acts on the axial center AC, the trailing arm 12 is provided. The rotational force generated in the step can be transmitted to the torsion beam 13 via the spring seat 16. As shown in FIG. 8, since the spring seat 16 is connected to the inclined surface 13c formed on the torsion beam 13, even if a rotational force is generated on the trailing arm 12, it acts on the torsion beam 13 due to peeling of the spring seat 16 or the like. Thus, the torsion beam 13 can be prevented from being bent or bent.

  Furthermore, as described above, the axle bracket 15 is provided with the second auxiliary member 15e on the front side surface portion 15a. According to this configuration, the mounting rigidity of the axle bracket 15 is improved, and when a side impact load is applied to the shaft center AC, the side impact load acting on the outer panel 30 is transmitted via the second auxiliary member 15e to the inner panel. 20 is transmitted to the rear part 12b of the trailing arm 12 from the bent part 12d of the trailing arm 12, and the twisting and bending of the bent part 12d can be promoted.

<Other embodiments>
The present invention is not limited to the embodiment described above, and can be substituted without departing from the spirit of the claims.

  For example, in the above-described embodiment, the vehicle is an FF type vehicle, but the vehicle may be a four-wheel drive type vehicle.

  Further, other vehicle parts arranged around the torsion beam 13 are not limited to the fuel tank F, and various parts can be appropriately arranged. Specifically, for example, parts arranged in front of the torsion beam 13 include parts such as a high-voltage battery of an EV vehicle in addition to the fuel tank F. In addition, examples of components disposed behind the torsion beam 13 include components such as a canister, a urea tank that can be disposed in a diesel engine vehicle, and a generator of an EV vehicle.

  The shape of the torsion beam 13 is not limited to the shape of the first embodiment, and may be a shape in which one place or a plurality of places are narrowed in a plan view or a bottom view. Further, the narrowed portion is not limited to the torsion beam central portion 13b at the center of the vehicle, and may be arranged at a position shifted from the center of the vehicle.

  Further, the cross-sectional shape of the torsion beam central portion 13b is not limited to a substantially U shape, and may be a substantially U shape, a substantially arc shape, a substantially U shape, or the like.

  The trailing arm 12 is not limited to the joined body formed by the inner panel 20 and the outer panel 30, and may be a single member or may be a member that is further divided and joined.

  In the first embodiment, as shown in FIG. 6, the entire bent portion 12 d is formed so as to be disposed below the axial center AC, that is, the straight line AC <b> 1, but from the viewpoint of improving the layout of the vehicle. In addition, a part of the bent portion 12d may be disposed below the axis AC. Note that, from the viewpoint of reliably converting a side impact load acting on the shaft center AC into a rotational force and promoting twisting and bending in the bent portion 12d, the entire bent portion 12d is disposed below the shaft center AC. It is desirable to adopt a configuration.

  The above-described embodiments are merely examples, and the scope of the present invention should not be interpreted in a limited manner. The scope of the present invention is defined by the scope of the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention includes a torsion beam suspension having a pair of left and right trailing arms that extend in the longitudinal direction of the vehicle and support the left and right rear wheels, and a torsion beam that extends in the vehicle width direction and connects the trailing arms. It is useful as a rear suspension structure for automobiles.

10 Torsion beam suspension, suspension 12 Trailing arm 12a (trailing arm) front portion 12b (trailing arm) rear portion 12c Attachment portion 12d Bending portion 13 Torsion beam 13a Torsion beam end portion 13b Torsion beam central portion 13c Inclined surface 14 Suspension bush 15 Axle bracket (mounting bracket)
15a front side part 15b rear side part 15c outer side part 15d first auxiliary member 15e second auxiliary member (arm part)
15f Notch portion 16 Spring seat 16a Bottom wall portion 16b Transition portion 16c Flange portion 16d Extension portion 16e Spring mounting portion 20 Inner panel (inner member)
25 Inner recess (recess)
30 Outer panel (outer member)
35 Outer recessed portion 51 Axle unit 52 Hub 52a Hub flange 52b Shaft portion 53 Housing 53a Housing flange portion 54 Ball 70 Damper bracket 100 Fastening member 101 Fastening bolt 121 Joining portion AC Axle (center axis of rear wheel)
AC1 straight line F fuel tank S vehicle rear suspension structure

Claims (9)

A rear portion of a vehicle comprising a torsion beam suspension having a pair of left and right trailing arms extending in the vehicle longitudinal direction and supporting left and right rear wheels, and a torsion beam extending in the vehicle width direction and connecting the trailing arms. Suspension structure,
The width of the torsion beam in the longitudinal direction of the vehicle gradually decreases from the trailing arm side toward the vehicle center,
The trailing arm includes a bent portion between the joint portion of the torsion beam and the mounting portion of the rear wheel,
A part or all of the bent portion is disposed below the central axis of the rear wheel ,
The vehicle in the vehicle width direction on the rear side of the bent portion of the trailing arm is larger than the width in the vehicle width direction on the front side of the bent portion of the trailing arm. Rear suspension structure. The rear suspension structure of the vehicle according to claim 1 ,
The vehicle rear suspension structure according to claim 1, wherein the bent portion includes a recess formed on an inner side in the vehicle width direction of the trailing arm. The vehicle rear suspension structure according to claim 2 ,
A pair of left and right spring seats arranged so as to span the torsion beam and the trailing arm at a corner portion formed on the inner rear side of the joint between the torsion beam and the trailing arm;
The torsion beam includes an inclined surface that is inclined from the rear toward the front center side on the joint portion side,
The rear suspension structure of a vehicle, wherein the spring seat is connected to the inclined surface. In the rear suspension structure of the vehicle according to claim 3 ,
A rear suspension structure of a vehicle, wherein an extension portion is formed at the front end of the spring seat so as to extend inward in the vehicle width direction and toward the center upward along the inclined surface. In the rear suspension structure of the vehicle according to any one of claims 1 to 4 ,
The rear wheel is supported on the outside of the trailing arm via a mounting bracket fixed to the mounting portion,
The rear suspension structure of a vehicle, wherein the mounting bracket includes an arm portion extending so as to hold the trailing arm from the outside to the inside of the trailing arm. In the rear suspension structure of the vehicle according to claim 5 ,
Each of the trailing arms includes an inner member disposed on the inner side in the vehicle width direction, and an outer member joined to the inner member and disposed on the outer side in the vehicle width direction,
The rear suspension structure of a vehicle, wherein an arm portion of the mounting bracket extends from the outer member to the inner member. The vehicle rear suspension structure according to claim 6 ,
The rear suspension structure of a vehicle, wherein a thickness of the outer member is larger than a thickness of the inner member. In the rear suspension structure of the vehicle according to any one of claims 1 to 7 ,
A rear suspension structure of a vehicle, wherein a fuel tank is disposed in front of the torsion beam. A rear portion of a vehicle comprising a torsion beam suspension having a pair of left and right trailing arms extending in the vehicle longitudinal direction and supporting left and right rear wheels, and a torsion beam extending in the vehicle width direction and connecting the trailing arms. Suspension structure,
The width of the torsion beam in the longitudinal direction of the vehicle gradually decreases from the trailing arm side toward the vehicle center,
The trailing arm includes a bent portion between the joint portion of the torsion beam and the mounting portion of the rear wheel,
A part or all of the bent portion is disposed below the central axis of the rear wheel,
The rear wheel is supported on the outside of the trailing arm via a mounting bracket fixed to the mounting portion,
The mounting bracket includes an arm portion extending so as to hold the trailing arm from the outside to the inside of the trailing arm,
Each of the trailing arms includes an inner member disposed on the inner side in the vehicle width direction, and an outer member joined to the inner member and disposed on the outer side in the vehicle width direction,
The arm portion of the mounting bracket extends so as to straddle from the outer member to the inner member,
The thickness of the outer member is greater than the thickness of the inner member
A rear suspension structure of a vehicle characterized by the above.

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