JP2015131598A - Torsion beam and torsion beam type suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torsion beam which is high in stiffness, reducible in weight, and can obtain sufficient durability rigidity.SOLUTION: A torsion beam is formed into a shape which comprises a pair of opposing sidewalls and a ceiling wall for connecting end edges of a pair of the sidewalls, has a substantially-U-shaped cross section, and is opened at one side. Furthermore, the torsion beam comprises: high-rigidity parts which are arranged at both sides of the torsion beam, whose ceiling walls are formed into flat plate shapes, in which side walls and the ceiling walls are connected to each other in bent states, and whose cross sections are rectangular; and low-rigidity parts which are arranged between the high-rigidity parts while continuing to the high-rigidity parts, whose ceiling walls are bent, and in which sidewalls and the ceiling walls are continuously connected to each other.

Description

  The present invention relates to a torsion beam used for a vehicle suspension system.

  A torsion beam suspension using a torsion beam has a structure in which a pair of trailing arms provided on the left and right sides of a vehicle are connected by a torsion beam, and the torsion beam allows the operation of the trailing arm by bending and twisting. Since the vehicle is always returned to and held in a predetermined state, the structure is relatively simple, and there are advantages such as reduction in vehicle cost and weight.

  It is known that the torsion beam is generally superior in terms of torsion when the cross-section is made close to a circle even if members of the same thickness are used, and the rigidity increases and holding power prevails when the cross-section is made close to a rectangle. ing.

JP 2011-88461 A JP 2013-60177 A

  However, when the rigidity of the torsion beam is increased, a high stress is generated at the joint portion with the trailing arm when the torsion beam is twisted or the like. Therefore, the conventional torsion beam type suspension has been used for a vehicle having a relatively light weight by reducing the rigidity of the torsion beam to make it easy to twist in consideration of durability.

  For large vehicles that require rigidity, it is conceivable to supplement the rigidity of the suspension with, for example, an anti-roll bar. However, this increases the cost and increases the weight, resulting in a torsion beam. The advantage of using a suspension was offset.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a torsion beam that can achieve high rigidity, light weight, and sufficient durability, and a torsion beam suspension using the torsion beam.

  In order to solve the above-mentioned problems, the present invention is configured as follows in a torsion beam suspension for a vehicle in which a torsion beam is provided between a pair of left and right trailing arms.

  The torsion beam has a shape in which one of the substantially U-shaped cross sections is open, including a pair of opposed side walls and a ceiling wall that connects the edges of the pair of side walls. Further, the torsion beam is provided on both sides of the torsion beam, the ceiling wall is flat, and the side wall and the ceiling wall are connected in a bent state. A low-rigidity portion having an inverted U-shaped cross section, wherein the ceiling wall is curved, and the side wall and the ceiling wall are continuously connected between the rigid portions. And configured.

  According to the present invention, it is possible to provide a torsion beam of a torsion beam type suspension that can achieve high rigidity and light weight and satisfy durability.

The perspective view which shows the vehicle provided with the torsion beam of one Embodiment concerning this invention. The perspective view which shows the torsion beam type suspension which has the torsion beam. The perspective view which shows the torsion beam. The side view which shows the torsion beam. The top view which shows the torsion beam. The bottom view which shows the torsion beam. Sectional drawing which fractures | ruptures and shows the torsion beam of FIG. 4 by F7-F7 line | wire. Sectional drawing which fractures | ruptures and shows the torsion beam of FIG. 4 by the F8-F8 line. Sectional drawing which fractures | ruptures and shows the torsion beam of FIG. 4 at the F9-F9 line. The top view which shows a torsion beam type suspension. The perspective view which expands and shows a part of the torsion beam type suspension. The perspective view which expands and shows a part of the torsion beam type suspension. The cross-sectional perspective view which expands and shows a part of the torsion beam type suspension.

  A torsion beam 10 according to an embodiment of the present invention will be described. FIG. 1 is a perspective view showing a vehicle 12 provided with a torsion beam suspension 14 using a torsion beam 10 on a suspension of a rear wheel 18. FIG. 2 is a perspective view showing a state in which the torsion beam type suspension 14 is viewed from an obliquely forward position. FIG. 3 is a perspective view showing a state in which the torsion beam 10 is viewed from an obliquely forward position. FIG. 4 is a side view showing the torsion beam 10 as viewed from the front.

  Hereinafter, in the state where the torsion beam 10 is provided on the vehicle 12, the forward direction of the vehicle 12 is defined as the front, the opposite direction is defined as the rear, the left and right are determined based on them, and the direction of gravity is defined as the downward direction. In the following description, the opposite is the upper direction, basically the side toward the center of the vehicle 12 is the inner side or the inner side, and the opposite is the outer side or the outer side.

  FIG. 1 shows a vehicle 12. The vehicle 12 is a passenger car and uses a torsion beam suspension 14 as a suspension device for the rear wheel 18. As shown in FIG. 2, the torsion beam type suspension 14 includes a pair of trailing arms 20 on the left and right sides, and the pair of trailing arms 20 are joined by a torsion beam 10 provided therebetween.

  The trailing arm 20 includes a connecting portion 22 at one end on the front side, and an attachment base 24 on the other end side. The connecting portion 22 is attached to the vehicle 12 so as to be rotatable in the vertical direction, and the rear wheel 18 is assembled to the attachment base 24 via a hub. In addition, other components such as shock absorbers and coil springs are attached between the torsion beam suspension 14 and the vehicle 12.

  The torsion beam 10 is made of, for example, a thin metal plate, and has a generally U-shape that is surrounded by side walls 40 and 42 and a ceiling wall 44 and has an open lower surface, as shown in FIGS. As shown in FIGS. 4 to 6, the torsion beam 10 is generally bilaterally symmetric, has substantially the same height in the longitudinal direction, and is basically formed with a uniform thickness. FIG. 5 is a plan view of the torsion beam 10, and FIG. 6 is a bottom view of the torsion beam 10.

  The torsion beam 10 has a left end edge 26 formed in accordance with the left trailing arm 20 at the left end portion (to the right in FIG. 4) of the torsion beam 10, and the right trailing arm 20 at the right end portion. A right end edge 28 formed in conformity with the above is provided.

  As shown in FIG. 3 and the like, a first high-rigidity portion 30, a low-rigidity portion 34, and a second high-rigidity portion 38 are formed on the torsion beam 10 from the left end edge 26 side. More specifically, the torsion beam 10 is formed with a first high-rigidity portion 30 in a portion from the left end edge 26 to the length a, and then a low-rigidity portion 34 having a length b across the first transition portion 32. Further, a second high-rigidity portion 38 having a length a is formed up to the right end edge 28 with the second transition portion 36 interposed therebetween.

  Next, each part of the torsion beam 10 will be described. The first high-rigidity portion 30 and the second high-rigidity portion 38 are formed substantially symmetrically with the low-rigidity portion 34 interposed therebetween. Therefore, the first high-rigidity portion 30 will be described and the second high-rigidity portion 38 will be described. The same reference numerals are given to the same parts as those of the first high-rigidity part 30, and the description thereof is omitted.

  FIG. 7 shows a cross-sectional view of the torsion beam 10 in FIG. 4 taken along line F7-F7. As shown in FIG. 7, the first high-rigidity portion 30 includes a pair of side walls 40a and 42a provided on the front and rear sides, and a ceiling wall 44a. The side wall 40a, the side wall 42a, and the ceiling wall 44a are all flat, and the side wall 40a and the ceiling wall 44a, and the side wall 42a and the ceiling wall 44a are bent at substantially right angles at the corners 33, respectively. doing.

  The height of the side walls 40a and the like is H1, and the length of the ceiling wall 44a in the lateral direction is L2, and they have substantially the same length and width. Therefore, the first high-rigidity portion 30 has a U-shaped cross section formed in a substantially square shape over the length a.

  An edge 31 bent outward is formed at the lower part of the side wall 40a and the side wall 42a. The edge 31 is formed with substantially the same width throughout the torsion beam 10. The first high-rigidity portion 30 is provided from the position of the left end edge 26 to the length a, and the length a is about ¼ of the entire length L1 of the torsion beam 10.

  A low rigidity portion 34 is provided between the first high rigidity portion 30 and the second high rigidity portion 38 as shown in FIG. As shown in FIG. 9, the low-rigidity portion 34 includes side walls 40b and 42b and a semicircular ceiling wall 44b. FIG. 9 is a cross-sectional view of the torsion beam 10 in FIG. 3 taken along line F9-F9.

  The side walls 40b and 42b are flat and have a height of H2. H2 is about 1/2 the height of H1. The ceiling wall 44b is substantially semicircular, and both end edges of the ceiling wall 44b are continuously connected to the upper edge of the side wall 40b and the side wall 42b, respectively. The term “continuously connected” means that the side wall 40b, the side wall 42b, and the ceiling wall 44b continue in a smooth curve without bending. Therefore, as shown in FIG. 9, the low-rigidity portion 34 has an inverted U-shaped cross-sectional shape from the side wall 40b, the side wall 42b, and the semicircular ceiling wall 44b.

  Further, in the low rigidity portion 34, the height H3 from the lower end of the edge portion 31 to the top portion 55 of the ceiling wall 44b is substantially the same as the height H1. Therefore, as shown in FIG. 4, the low rigidity portion 34 is continuously formed at the same height as the first high rigidity portion 30 and the second high rigidity portion 38.

  As shown in FIG. 3, a first transition portion 32 is provided between the first high-rigidity portion 30 and the low-rigidity portion 34, and a second transition portion is provided between the low-rigidity portion 34 and the second high-rigidity portion 38. 36 is provided. The first transition part 32 and the second transition part 36 each have a length c.

  The first transition portion 32 and the second transition portion 36 connect the first high-rigidity portion 30 and the low-rigidity portion 34, and the low-rigidity portion 34 and the second high-rigidity portion 38 with curved surfaces that continuously change. . FIG. 8 shows a cross-sectional view of the torsion beam 10 in FIG. 3 taken along line F8-F8. FIG. 8 is a cross-sectional view in which the first transition portion 32 is broken at the central portion of the first transition portion 32.

  As shown in FIG. 8, the central portion of the first transition portion 32 has a cross-sectional shape that is intermediate between the cross-sectional shape of the first high-rigidity portion 30 and the low-rigidity portion 34. As a result, when the first transition portion 32 or the like is displaced between the first high-rigidity portion 30 and the low-rigidity portion 34 or the like, between the first high-rigidity portion 30 and the low-rigidity portion 34. Thus, stress is transmitted without causing stress concentration.

  As shown in FIG. 4, reinforcing members 60 are attached to the insides of the first high-rigidity portion 30 and the second high-rigidity portion 38 in an inclined manner. As shown in FIGS. 11 and 12, the reinforcing member 60 includes a substrate 62 and side plates 64 provided on both sides of the substrate 62.

  11 and 12 show the vicinity of the second high-rigidity portion 38 of the torsion beam 10. The reinforcing member 60 is provided symmetrically in the first high-rigidity portion 30 as in the second high-rigidity portion 38. The substrate 62 is substantially flat, and the side plates 64 are provided at the front and rear ends of the substrate 62 at an angle substantially perpendicular to the substrate 62. The reinforcing member 60 has a U-shape with a flat cross section due to the substrate 62 and the side plate 64. Further, the outer end portion 61 and the inner end portion 63 of the reinforcing member 60 are each formed in parallel with the longitudinal direction of the torsion beam 10.

  The reinforcing member 60 is provided obliquely inside the second high-rigidity portion 38, and the outer end portion 61 of the reinforcing member 60 is joined to the lower end of the right end edge 28 of the torsion beam 10. Further, the outer end portion 61 of the reinforcing member 60 is formed along the shape of the trailing arm 20 and is fixed to the trailing arm 20 by welding together with the right end edge 28 of the torsion beam 10.

  The inner end 63 of the reinforcing member 60 is joined at the boundary between the second transition portion 36 and the second high-rigidity portion 38 with a slight gap between the ceiling wall 44a as shown in FIG. ing. The reinforcing member 60 is fixed inside the torsion beam 10 by welding. The welding location of the reinforcing material 60 and the torsion beam 10 is shown in FIG. As shown in FIG. 13, the welding is performed on the reinforcing material 60 at a position marked with a cross in FIG.

  Next, the effect of the torsion beam 10 will be described. As shown in FIGS. 2 and 10, the torsion beam 10 is provided between a pair of trailing arms 20 and constitutes a torsion beam suspension 14. As shown in FIG. 1, the torsion beam suspension 14 is attached to the vehicle 12 and supports the rear wheel 18.

  While the vehicle 12 is traveling, for example, when the rear wheel 18 moves up and down through the road surface unevenness, or when the vehicle 12 turns and a so-called roll is generated in the vehicle 12, the left and right trailing arms 20 are The torsion beam 10 is operated separately on the left and right sides, and the torsion beam 10 is twisted and bent.

  In FIG. 10, for example, when the right rear wheel 18 rises with respect to the left rear wheel 18, the left trailing arm 20 rises, and the displacement of the right rear wheel 18 changes from the first high-rigidity portion 30 to the first transition portion 32. To the low-rigidity portion 34. On the other hand, if the left rear wheel 18 does not rise, a twist occurs between the torsion beam 10, that is, between the first high-rigidity portion 30 and the second high-rigidity portion 38.

  Since the cross sections of the first high-rigidity portion 30 and the second high-rigidity portion 38 are rectangular, between the trailing arm 20 and the first high-rigidity portion 30 and between the trailing arm 20 and the second high-rigidity portion 38. In between, it is difficult to deform in any direction of up, down, left and right. Therefore, the twisting force is transmitted from the first high-rigidity portion 30 to the low-rigidity portion 34 via the first transition portion 32 and from the second high-rigidity portion 38 via the second transition portion 36.

  Since the low-rigidity portion 34 is formed in an inverted U-shaped cross section, when a reverse twisting force is transmitted from the first high-rigidity portion 30 and the second high-rigidity portion 38 to the low-rigidity portion 34, It is appropriately deformed along the curve of the semicircular ceiling wall 44b. Since the torsion is absorbed by the low-rigidity portion 34, no great stress is generated at the joint portion between the first high-rigidity portion 30 and the trailing arm 20, the second high-rigidity portion 38 and the trailing arm 20, or the like.

  Further, torsional force is transmitted from the first high-rigidity portion 30 to the low-rigidity portion 34 and from the second high-rigidity portion 38 to the low-rigidity portion 34 via the first transition portion 32 and the second transition portion 36. Therefore, stress concentration does not occur even in such a portion. The ease of twisting of the torsion beam 10 is appropriately increased or decreased according to the length b of the low-rigidity portion 34 and the lengths c of the first transition portion 32 and the second transition portion 36.

  As a result, the trailing arm 20 operates smoothly, and the rear wheel 18 moves up and down following the road surface. In addition, since excessive stress is not generated in any part of the torsion beam 10, there is no problem in durability.

  Then, when the travel path becomes flat or the vehicle 12 shifts to straight travel, the torsion beam 10 eliminates the twist by the restoring force and returns to a predetermined state. When the torsion beam 10 returns, the first high-rigidity portion 30 and the second high-rigidity portion 38 respectively hold the trailing arm 20 in the torsion beam suspension 14, thereby stabilizing the rear wheel 18 in a predetermined state.

  Further, when a roll is generated in the vehicle 12, the first high-rigidity portion 30 and the second high-rigidity portion 38 having a rectangular cross section are connected to the trailing arm 20 with a predetermined length a. 18 is held stably.

  In addition, when a stress is applied that causes the rear wheel 18 to be displaced in the left-right direction relative to the traveling direction, that is, in the direction of R1 in FIG. 10, the low-rigidity portion 34 is appropriately deformed to absorb excessive force and (1) The ceiling wall 44a such as the high-rigidity portion 30 and the outer end portion 61 of the reinforcing member 60 mainly correspond to the stress and stably hold the trailing arm 20.

  Similarly, when a stress is applied to move the rear wheel 18 in the up / down direction, ie, in the direction of the camber, the low-rigidity portion 34 is appropriately deformed to absorb excessive force and The side walls 40a and 42a of the high-rigidity portion 30 and the like mainly correspond to the stress and stably hold the trailing arm 20.

  Further, when the torsion beam 10 is twisted, stress may concentrate on the corner portions 33 of the first high-rigidity portion 30 and the second high-rigidity portion 38. On the other hand, since the reinforcing member 60 is welded and joined to the torsion beam 10 at a position avoiding the corner portion 33 (20 mm to 30 mm), the stress applied to the first high-rigidity portion 30 and the second high-rigidity portion 38. Can be dispersed to prevent stress concentration. Further, since the reinforcing member 60 is welded to the torsion beam 10 at a position avoiding the corner portion 33, the corner portion 33 is formed in a so-called angled state close to a right angle.

  Thus, even when a stress that causes torsion or deflection occurs in the torsion beam 10, the first high-rigidity portion 30 and the second high-rigidity portion 38 have a rectangular cross section. Such a displacement is unlikely to occur in the trailing arm 20.

  Therefore, the torsion beam type suspension 14 appropriately escapes torsion and deflection at the low-rigidity portion 34, and the first high-rigidity portion 30 and the second high-rigidity portion 38 securely hold the trailing arm 20, thereby preventing the vehicle 12 from being damaged. Don't make it stable.

  Further, since the reinforcing member 60 is provided obliquely in the vertical direction inside the first high-rigidity portion 30 and the second high-rigidity portion 38, twisting and deflection are generated in joining with the trailing arm 20. In addition to being suppressed more strongly, the trailing arm 20 and the first transition portion 32 and the like are strongly joined so that there is no problem in durability or the like. As a result, the torsion beam suspension 14 can be used for heavy vehicles while having the advantage of the light weight and simple structure of the torsion beam suspension.

  In addition, this invention is not restricted to the said embodiment, In the range which does not deviate from the range demonstrated, it can change suitably.

  The present invention can be used for a torsion beam suspension of a vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Torsion beam, 12 ... Vehicle, 14 ... Torsion beam type suspension, 18 ... Rear wheel, 20 ... Trailing arm, 22 ... Connecting part, 24 ... Mounting base, 26 ... Left edge, 28 ... Right edge, 30 ... 1st High rigidity portion, 31 ... edge portion, 32 ... first transition portion, 33 ... corner portion, 34 ... low rigidity portion, 36 ... second transition portion, 38 ... second high rigidity portion, 40, 42 ... side wall, 44 ... Ceiling wall, 55 ... top, 60 ... reinforcing material, 61 ... outer end, 62 ... substrate, 63 ... inner end, 64 ... side plate

Claims (5)

In a torsion beam suspension for a vehicle in which a torsion beam is provided between a pair of left and right trailing arms,
The torsion beam includes a pair of opposed side walls and a ceiling wall that connects the edges of the pair of side walls, and has a shape in which one of the substantially U-shaped cross sections is open,
Furthermore, the torsion beam is
A high-rigidity portion having a rectangular cross section, which is provided on both sides of the torsion beam, the ceiling wall is flat, and the side wall and the ceiling wall are connected in a bent state;
Between the high-rigidity parts, the ceiling wall that is provided continuously to the high-rigidity part is curved, and the side wall and the ceiling wall are continuously connected. A torsion beam comprising a rigid portion. In the high rigidity portion, the height width of the side wall and the length width of the ceiling wall between the side walls are substantially the same,
The torsion beam according to claim 1, wherein a reinforcing material is provided inside the high-rigidity portion.   The reinforcing member has a U-shaped cross section including a substrate and side plates provided at both ends of the substrate, one end is provided at a lower end of the edge of the torsion beam, and the other ends are the high-rigidity portion and the low-rigidity portion. The torsion beam according to claim 2, wherein the torsion beam is provided in the vicinity of the ceiling wall at a boundary portion of the torsion beam.   The said reinforcing material is welded to the said highly rigid part at the said other end, avoiding the corner | angular part where the said ceiling wall and the said side wall of the said highly rigid part cross | intersect. Torsion beam.   A torsion beam type suspension comprising a trailing arm provided at both ends of the torsion beam according to claim 1.

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