JP2010274716A - Hollow stabilizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hollow stabilizer suppressing thickness reduction and flatness due to bending of a pipe-like material, and preventing the deterioration of durability even when saving weight by reducing the thickness of the material. <P>SOLUTION: The hollow stabilizer includes a torsion part extended in the width direction of a vehicle, arm parts positioned on both end parts of the torsion part, and a bent part connecting the torsion part to the arm part. When expressions are as follows by using thickness t<SB>1</SB>outside the bent part 30, thickness t<SB>2</SB>inside the bent part 30, and thickness t<SB>0</SB>of the pipe-like material (material before bending) shown in Fig.11: thickness reduction rate &delta;<SB>1</SB>outside the bent part 30=(t<SB>0</SB>-t<SB>1</SB>)/t<SB>0</SB>&times;100(%); thickness increase rate &delta;<SB>2</SB>inside the bent part 30=(t<SB>2</SB>-t<SB>0</SB>)/t<SB>0</SB>&times;100(%), the ratio of the thickness reduction rate &delta;<SB>1</SB>outside the bent part 30 to the thickness increase rate &delta;<SB>2</SB>inside the bent part 30 (=bent part inner and outer thickness variation ratio &delta;<SB>2</SB>/&delta;<SB>1</SB>) satisfies &delta;<SB>2</SB>/&delta;<SB>1</SB>&ge;1.75. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a hollow stabilizer that suppresses a roll generated in a vehicle, and more particularly, to setting a thickness of the hollow stabilizer.

  As shown in FIG. 7, the stabilizer 1 includes a torsion part 11 extending in the vehicle width direction, arm parts 12 positioned at both ends of the torsion part 11, and a curve connecting the torsion part 11 and the arm part 12. A portion 13 (shoulder) is provided. In the stabilizer 1, the arm part 12 changes the input of the up-down direction which becomes a right-and-left reverse phase into a torsion moment, and the torsion part 11 receives the torsion moment. Reference numeral 14 denotes a bush.

  In the stabilizer 1, the torsion part 11 is supported on the vehicle body side via a support member 18 such as a bush 14 and a bracket, and the arm part 12 is connected to an axle side member such as a suspension arm via a stabilizer link (not shown). The In the stabilizer 1, when vertical loads in opposite directions are input to the arm portion 12 during turning of the vehicle, the arm portion 12 is bent in the opposite direction and the torsion portion 12 is twisted. Thus, the roll which generate | occur | produces in a vehicle body is suppressed by the spring effect | action which arises in each site | part of the stabilizer 1. FIG.

  Solid materials and hollow materials are used as stabilizer materials (for example, Patent Documents 1 to 3). Under the circumstance that reducing carbon dioxide emissions is an important issue in the world, the demand for weight reduction of automobile parts is strong, so the use of hollow materials is being attempted, and hollow materials are applied to materials with relatively low stress. . As the hollow material, an electric sewing tube or a pipe material obtained by drawing an electric sewing tube into a predetermined size is used.

  The hollow stabilizer is manufactured by using a pipe bender 20 shown in FIG. 8 and bending a pipe P, which is a hollow material, into a predetermined shape. FIG. 8 is a perspective view showing a schematic configuration of the entire pipe bender 20 and showing a state in which the pipe P is being bent. The pipe bender 20 includes a rotary bending die 21, a clamping die 22, and a pressure die 23. The rotary bending die 21 has an arc-shaped molding surface and is rotated by a rotation drive mechanism (not shown). The clamping die 22 fixes the pipe P. The pressure die 23 is pressed toward the center of the rotary bending die 21 and pinches the pipe P with the rotary bending die 21.

  In the pipe vendor 20, the pipe P is fixed to the clamping die 22 as shown in FIG. 9, and the clamping die 22 to which the pipe P is fixed is a rotary bending die as shown in FIGS. 10 (A) and 10 (B). Rotate with 21. Thereby, the pipe P is bent so as to be wound around the rotary bending die 21. In this case, the pipe P is drawn in the direction of the clamping die 22, and the pressure die 23 moves together with the pipe P while maintaining the pressing force toward the center of the rotary bending die 21.

JP-A-8-142632 Japanese Patent No. 3886106 Patent No. 4087765

A curved portion 30 shown in FIG. 11A is formed on the pipe P obtained by the bending process as described above. Symbol C indicates the bending center. Bending stress is applied to the bending portion 30 (tensile stress on the outside of the bending portion and compressive stress on the inside of the bending portion), and the thickness of the bending portion 30 is thick on the inside of the bending and thin on the outside of the bending. The inside of the bending portion is the bending center C side, and the outside of the bending portion is the opposite side to the bending center C side. Here, when the thickness on the outer side of the bending portion 30 is t ₁ , the thickness on the inner side of the bending is t ₂ , and the thickness of the pipe material (pipe before bending) is t ₀ , as shown in FIG. When the thickness reduction rate δ _{1 on the} outer side of the bending portion 30 and the thickness increase rate δ ₂ on the inner side of the bending portion are expressed as follows, in the normal hollow stabilizer, the ratio of change rate δ ₂ / δ ₁ is about 0.45 to 1.5.
δ ₁ = (t ₀ −t ₁ ) / t ₀ × 100 (%)
δ ₂ = (t ₂ −t ₀ ) / t ₀ × 100 (%)

Moreover, in the bending part 30, as shown to FIG. 11 (B), the flatness which becomes a short diameter in the bending radial direction of a pipe cross section and becomes a long diameter in the perpendicular | vertical direction arises. When the major axis is D ₁ , the minor axis is D ₂ , and the material diameter is D ₀ , the outer diameter increase rate γ _{1 in the} direction perpendicular to the bending radius direction (that is, the minor axis direction) and the outer diameter decrease rate γ in the bending radius direction ₂ is expressed as follows, and γ ₁ is 4% or less because γ ₁ is constrained by a bending die (see FIG. 10B), but γ ₂ is about ₂ to 15%.
γ ₁ = (D ₁ −D ₀ ) / D ₀ × 100 (%)
γ ₂ = (D ₀ −D ₂ ) / D ₀ × 100 (%)

However, in general, a curved portion has a maximum stress in a hollow stabilizer. When the thickness on the outside of the bending portion is reduced, the section modulus of the bending portion is decreased, so that the response of the bending portion is increased and the spring constant is decreased. As a result, since durability is lowered, it is necessary to increase the thickness of the pipe material in consideration of thinning of the curved portion. Also, bending the flat is gamma ₂ increases occurred in processing, similar to the thinning, since the section modulus of the bending portion is reduced, the stress increases with the spring constant reduction of bend occurs. As a result, durability is reduced.

  Therefore, the present invention provides a hollow stabilizer that can suppress a reduction in thickness and flatness due to bending of a pipe material, and can reduce the thickness of the pipe material and reduce the weight without impairing durability. The purpose is that.

A hollow stabilizer according to the present invention is a hollow stabilizer including a torsion portion extending in the width direction of a vehicle, arm portions located at both ends of the torsion portion, and a curved portion connecting the torsion portion and the arm portion. The thickness reduction rate δ ₁ = (t ₀ −t ₁ ) on the outside of the curved portion is calculated using the thickness t _{1 on the} outside of the curved portion, the thickness t _{2 on the} inside of the curved portion, and the thickness t ₀ of the pipe-shaped material. / T ₀ × 100 (%), the thickness increase rate δ ₂ inside the curved portion δ ₂ = (t ₂ −t ₀ ) / t ₀ × 100 (%), the thickness decrease rate δ ₁ outside the curved portion The ratio δ ₂ / δ ₁ between the thickness increase rate δ ₂ on the inner side of the curved portion satisfies δ ₂ / δ ₁ ≧ 1.75.

In the hollow stabilizer of the present invention, the ratio of the thickness reduction rate δ ₁ outside the curved portion and the thickness increase rate δ ₂ inside the curved portion satisfies δ ₂ / δ ₁ ≧ 1.75. The thickness reduction and flatness due to bending can be suppressed, and the thickness of the pipe material can be reduced and the weight can be reduced without impairing the durability.

Various configurations can be used for the hollow stabilizer of the present invention. For example, the radial cross section of the material in the bending portion has a flat shape in which the bending direction of the material is the short diameter and the direction substantially orthogonal to the bending direction is the long diameter, and the short diameter is D ₂ and the material outer diameter D ₀ is set. used, when expressed as the outside diameter reduction rate in the short radial _{γ 2 = (D 0 -D 2} ) / D 0 × l00 (%), the outer diameter reduction rate gamma ₂ satisfies gamma ₂ ≦ 5 (percent) be able to.

  According to the hollow stabilizer of the present invention, thickness reduction and flatness due to bending of a pipe material can be suppressed, and the thickness of the pipe material can be reduced and reduced in weight without impairing durability. .

It is a sectional side view showing the schematic structure of the MOS bending apparatus used for the bending process of the hollow stabilizer which concerns on one Embodiment of this invention. The ratio (= t / D) between the thickness t of the material and the material diameter D (= t / D) and the movement distance L in the direction of arrow C (FIG. 1) and the rotation angle α in the direction of arrow B (FIG. 1) (= L / It is a graph showing the relationship with (α). The ratio of the thickness reduction rate δ ₁ (%) on the outside of the curved portion and the thickness increase rate δ ₂ (%) on the inside of the curved portion (= ratio of change in thickness between the inside and outside of the curved portion δ ₂ / δ ₁ ) and the bending radius And a graph showing the relationship between the outer diameter reduction rate γ ₂ (%) and the bending radius. It is a perspective view showing the schematic structure of the pipe bender used for the bending process of the hollow stabilizer which concerns on one Embodiment of this invention. It is a perspective view showing the structure of the hollow stabilizer manufactured in the Example. It is a sectional side view showing the state where buckling occurred in a MOS bending apparatus. It is a perspective view showing the structure of a hollow stabilizer. It is a perspective view showing schematic structure of the conventional pipe bender used for the bending process of a hollow stabilizer. It is a side view showing the process of bending by the conventional pipe bender. 9A shows a process of bending by a conventional pipe bender, FIG. 9A is a side view showing a process following the process of FIG. 9, and FIG. 9B shows a state in which the material is constrained by a rotary bending die in the process of FIG. It is radial direction sectional drawing showing. The structure of the curved part of a hollow stabilizer is represented, (A) is a side view showing the curved part of a hollow stabilizer, (B) is sectional drawing for demonstrating each parameter in the radial direction cross section of a curved part.

  Embodiments of the present invention will be described below with reference to the drawings. The hollow stabilizer of this embodiment is configured from the same portion as the conventional hollow stabilizer shown in FIG. 7, for example, but in order to improve durability, various values relating to the outer diameter and thickness of the curved portion are predetermined. This is different from the conventional hollow stabilizer in that it is set within the range.

That is, as shown in FIG. 11, the hollow stabilizer of the present embodiment has a wall thickness t _{1 on the} outside of the bending portion 30, a wall thickness t _{2 on the} inside of the bending portion 30, and a wall thickness t of the pipe material (material before bending). ₀ , the thickness decrease rate δ ₁ = (t ₀ −t ₁ ) / t ₀ × 100 (%) outside the curved portion 30, and the thickness increase rate δ ₂ = (t ₂ −t ₀ inside the curved portion 30. ) / T ₀ × 100 (%), the ratio of the thickness reduction rate δ ₁ outside the bending portion 30 to the thickness increase rate δ ₂ inside the bending portion 30 (= the ratio of the thickness change rate inside and outside the bending portion 30) δ ₂ / δ ₁ ) satisfies δ ₂ / δ ₁ ≧ 1.75. In this case, the radial cross section of the material in the bending portion has a flat shape in which the bending direction of the material has a short diameter and the direction substantially orthogonal to the bending direction has a long diameter, the short diameter D _{2 of} the bending portion, When the diameter D ₀ is used and the outer diameter reduction rate γ ₂ = (D ₀ −D ₂ ) / D ₀ × 100 (%) in the minor axis direction of the curved portion, the outer diameter reduction rate γ ₂ is γ ₂ ≦ 5 (%) can be satisfied.

  The manufacturing method of the hollow stabilizer of this embodiment is demonstrated with reference to drawings. FIG. 1 is a side cross-sectional view illustrating a schematic configuration of a MOS bending apparatus 100 that performs the method for manufacturing the hollow stabilizer of the present embodiment. The MOS bending apparatus 100 includes a first support portion 101, a second support portion 102 (hydraulic cylinder rod), a hydraulic cylinder 103, a first hinge mechanism 104, a second hinge mechanism 105, a movable jig 111, and a fixed jig. A tool 112 is provided.

  The upper end portion of the first support portion 101 is rotatably provided on the first hinge mechanism 104 fixed to the lower surface of the device member 201. The lower end portion of the first support portion 101 is rotatably provided at the left end portion of the second support portion 102 via the second hinge mechanism 105. The right end portion of the second support portion 102 is movably provided in a hydraulic cylinder 103 fixed to the device member 202. A movable jig 111 (for example, a die) is fixed to the first support portion 101 by a fastening jig (not shown).

  The movable jig 111 is movable in the arrow B direction and the arrow C direction. With respect to the direction of the arrow C, when the axial center of the fixed jig 112 and the movable jig 111 coincides with each other as a reference, when the arrow B direction is +, the arrow C direction also moves in the + direction. At-, the direction of arrow C also moves in the-direction. At this time, the device members 201 and 202 move in conjunction with each other.

  In the MOS bending apparatus 100, the pipe P (pipe material) is guided through the opening of the fixed jig 112 toward the movable jig 111 and passes through the opening of the movable jig 111. In this case, the pipe P is sent forward (left side in the figure) while applying a predetermined pushing force F from the rear end (right end in the figure) of the pipe P. At this time, the pipe P is rotated in the A direction at a predetermined position in the longitudinal direction, and the angle and the vertical position of the movable jig 111 are changed. Thereby, a hollow stabilizer having a predetermined bending radius and bending angle is obtained. When the B direction is + (C direction is also +), the pipe is bent upward in FIG. 1 (the state shown in FIG. 1). When the B direction is − (C direction is also −), the pipe is bent downward in FIG.

  For example, the pipe P is fed forward (left side in FIG. 1) while applying a pressing force F, and bending is performed at a position of 200 mm from the tip with a bending radius of 100 mm and a bending angle of 60 °. . Next, after the pipe P further moves forward by 50 mm, the pipe P is rotated by 30 ° in the direction of arrow A in FIG. 1, and then bending is performed by setting the bending radius to 50 mm and the bending angle to 20 °. In this way, a hollow stabilizer can be obtained by continuing the bending process in which various parameters are appropriately set at predetermined positions while feeding the pipe P to the left in FIG.

  FIG. 2 shows the ratio between the material thickness t and the material diameter D of the pipe P (= t / D) and the ratio of the movement distance L in the direction of arrow C to the rotation angle α in the direction of arrow B (= L / α). It is a graph showing the relationship. As L / α increases, the axial centers of the movable jig 111 and the fixed jig 112 are shifted, so that the bending resistance of the movable jig 111 increases (that is, the pushing force to the pipe P increases). ). When bending is performed with L / α set to an appropriate range, the compressive stress acting on the pipe P can be increased, so that the compressive stress of the curved portion 30 can be increased. As a result, the thickness reduction rate outside the curved portion can be reduced.

It was confirmed that δ ₂ / δ ₁ was 1.75 or more by molding in the bending region (mesh region) shown in FIG. Further, in this case, it was confirmed that the flatness γ _{2 of} the pipe can be similarly reduced. On the other hand, in the region where L / α is larger than the bending region in FIG. 2 (the region above line X), the pipe P is bent between the fixed jig 112 and the movable jig 111 as shown in FIG. It was confirmed that bending G occurred and bending could not be performed.

FIG. 3 shows the relationship between the bending radius of a hollow stabilizer bent by the MOS bending apparatus 100 and δ ₂ / δ ₁ . As can be seen from FIG. 3, δ ₂ / δ ₁ ≧ 1.75 was obtained, which was not obtained by conventional bending.

As described above, in the present embodiment, the ratio of the thickness reduction rate δ ₁ outside the curved portion and the thickness increase rate δ ₂ inside the curved portion satisfies δ2 / δ1 ≧ 1.75. It is possible to suppress the thickness reduction and flattening due to the bending process, and to improve the durability. As a result, even when the thickness of the pipe P is reduced, the same durability as the conventional one can be obtained.

  In the present embodiment, the MOS bending apparatus 100 is used for manufacturing the hollow stabilizer, but the apparatus used for manufacturing the hollow stabilizer is not limited to this, and various modifications are possible. For example, in bending by the conventional pipe bender 20 shown in FIG. 8, the rear end portion of the pipe P and the vicinity of the bending portion of the pipe P are chucked (not shown), and a pressing force F is applied to the pipe P, thereby The hollow stabilizer of the invention can be obtained. In this case, by setting the clearance of the pressure die 23 as appropriate, buckling does not occur even when the necessary pressing force F is applied, so that it is possible to suppress a decrease in thickness outside the bending portion of the bending portion.

    Hereinafter, the present invention will be described in more detail with reference to specific examples.

In the examples, pipes are used as materials, and as shown in Table 1, the bending radius, material diameter D ₀ , and material thickness t ₀ are changed for each material, and samples 11 to 16 are subjected to MOS bending, and comparative samples 11 to 11 are used. 16 was manufactured with a conventional pipe vendor. The shape of the hollow stabilizer was set to a substantially trapezoidal shape as shown in FIG. A hollow stabilizer 300 shown in FIG. 5 includes a torsion portion 301 extending in the vehicle width direction, arm portions 302 located at both ends of the torsion portion 301, and a bending portion 303 that connects the torsion portion 301 and the arm portion 302. And provided. The length of the torsion part 301 was 786 mm, and the length of the arm part 302 was 410 mm. The ratio of the thickness reduction rate δ ₁ outside the curved portion of the hollow stabilizer and the thickness increase rate δ ₂ inside the curved portion of each sample (= the ratio of the thickness change rate inside and outside the curved portion δ ₂ / δ ₁ ) and the outside diameter reduction rate The measured values of γ ₂ are shown in Table 1. In addition, the definitions of the inner / outer wall thickness change rate ratio δ ₂ / δ ₁ and the outer diameter reduction rate γ ₂ are the same as those in the embodiment.

Durability tests of the hollow stabilizers of Samples 11 to 16 and Comparative Samples 11 to 16 were performed. In the durability test, a constant load was applied to both sides of the hollow stabilizer. Using a pipe material diameter of φ24.2 mm and a thickness of 5 mm, the samples 11 to 13 are the bending method of the present application, and the comparative samples 11 to 13 are the conventional bending methods to manufacture the hollow stabilizer shown in FIG. 5, and 1800 N is provided on both sides of the stabilizer. In addition, a durability test was conducted. Similarly, a pipe material diameter of φ 26.5 mm and a thickness of 3.5 mm was used, samples 14 to 16 were manufactured by the bending method of the present application, and comparative samples 14 to 16 were manufactured by the conventional bending method to produce the hollow stabilizer shown in FIG. An endurance test was conducted with 2700 N added on both sides. The results of the durability test are shown in Table 1.

As can be seen from Table 1, with respect to the hollow stabilizers of Samples 11 to 16 and Comparative Samples 11 to 16, the results of comparing those having the same bending radius, material diameter D ₀ , and material thickness t ₀ (that is, Sample 11 and Comparison sample 11 comparison, sample 12 and comparison sample 12 comparison, sample 13 and comparison sample 13 comparison, sample 14 and comparison sample 14 comparison, sample 15 and comparison sample 15 comparison, sample 16 and comparison sample 16), the hollow stabilizers of Samples 11 to 16 in which the ratio of change in wall thickness δ ₂ / δ ₁ in the curved portion is large and set to 1.75 or more are the hollow stabilizers of Comparative Samples 11 to 16. It was found that the durability was better than that. As described above, it was confirmed that the durability was improved when the ratio of thickness change rate δ ₂ / δ _{1 in} the curved portion of the hollow stabilizer was within the range of the present invention.

  Stabilizer manufactured by a conventional bending method using a pipe having an outer diameter of 24.2 mm × wall thickness of 5 m, and a hollow stabilizer manufactured by the bending method of the present application using a pipe having an outer diameter of 24.2 mm × wall thickness of 3.5 mm When the same load was applied to both sides of the stabilizer and the durability test was conducted, it was found that both of them had almost the same durability. That is, it was found that the hollow stabilizer manufactured within the scope of the present invention can reduce the weight of the hollow stabilizer by 7.6%.

  DESCRIPTION OF SYMBOLS 1,300 ... Hollow stabilizer, 11, 301 ... Torsion part, 12, 302 ... Arm part, 13, 303 ... Curved part, P ... Pipe (pipe material)

Claims (2)

In a hollow stabilizer comprising a torsion part extending in the width direction of the vehicle, arm parts located at both ends of the torsion part, and a curved part connecting the torsion part and the arm part,
Using the outer wall thickness t _{1 of} the curved portion, the inner thickness t ₂ of the curved portion, and the thickness t ₀ of the pipe-shaped material,
Thickness reduction rate δ ₁ = (t ₀ −t ₁ ) / t ₀ × 100 (%) outside the curved portion,
When the thickness increase rate inside the curved portion δ ₂ = (t ₂ −t ₀ ) / t ₀ × 100 (%),
The ratio δ ₂ / δ ₁ between the thickness reduction rate δ ₁ outside the curved portion and the thickness increase rate δ ₂ inside the curved portion is:
Hollow stabilizer characterized by satisfying δ ₂ / δ ₁ ≧ 1.75. The cross section of the material in the radial direction in the curved portion has a flat shape in which the bending direction of the material has a short diameter, and the direction substantially perpendicular to the bending direction has a long diameter,
Using short diameter D ₂ and the material outer diameter D ₀ of the curved portion,
When the outer diameter reduction rate γ ₂ = (D ₀ −D ₂ ) / D ₀ × 100 (%) in the minor axis direction of the curved portion is expressed,
The hollow stabilizer according to claim 1, wherein the outer diameter reduction rate γ ₂ satisfies γ ₂ ≦ 5 (%).

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