WO2015186700A1 - Torsion beam suspension - Google Patents

Abstract

A torsion beam suspension according to one aspect of the present invention is provided with a pair of trailing arms, a torsion beam, a pair of first reinforcement members, and a pair of second reinforcement members. Each of the first reinforcement members is welded to the torsion beam so that at least a portion of the first reinforcement member, said at least portion of the first reinforcement member being that in which stress concentration caused by the torsion of the torsion beam occurs, is located within a region surrounded by a weld line along which the corresponding second reinforcement member is welded to the torsion beam.

Description

Torsion beam suspension Cross-reference of related applications

This international application claims priority based on Japanese Patent Application No. 2014-115004 filed with the Japan Patent Office on June 3, 2014. The entire contents are incorporated herein by reference.

The present invention relates to a torsion beam suspension.

A torsion beam suspension is known in which a torsion beam is connected to a trailing arm by bringing the outer surface of the trailing arm into contact with a notch provided at the end of the torsion beam and welding the contacted portion. However, the torsion beam suspension having such a structure tends to have low roll rigidity.

Therefore, a technique for improving roll rigidity using a reinforcing member called a gusset has been proposed (Patent Document 1). This gusset is a member to be welded on the outer surfaces of both ends of the torsion beam, and has a notch continuous with the notch of the torsion beam.

In this case, the trailing arm is connected to the torsion beam by bringing the outer surface into contact with the notch formed by the continuous notch and welding the portion with which the notch is in contact.

In this case, since the trailing arm and the torsion beam are firmly connected, the roll rigidity is improved as compared with the structure in which the gusset is not used.

Japanese Patent No. 4340480

However, in the configuration provided with this gusset, there is a problem that stress accompanying torsion of the torsion beam concentrates in the vicinity of the tip portion of the gusset, specifically, in the vicinity of the end portion in the direction from the trailing arm toward the torsion beam.

When such stress concentration occurred, there was a concern that the torsion beam would crack from that part, or that the gusset might peel off from the torsion beam at that part.

In one aspect of the present invention, it is desirable to provide a torsion beam type suspension that has a configuration using a gusset, is less likely to break at a stress concentration portion, and can increase roll rigidity.

A torsion beam suspension according to one aspect of the present invention is
A pair of trailing arms;
A torsion beam connected to each of the trailing arms at both ends in the axial direction;
A pair of first reinforcing members welded across the outer surface of the torsion beam and the respective trailing arms at both axial end portions of the torsion beam, wherein the outer edge portions of the first reinforcing members are welded. A pair of first reinforcing members (corresponding to gussets) fixed to the torsion beam and each trailing arm,
A pair of second reinforcing members welded across the inner surface of the torsion beam and each trailing arm at both axial end portions of the torsion beam, and outer edges of the second reinforcing members are welded. A pair of second reinforcing members fixed to the torsion beam and each of the trailing arms,
With
Each of the first reinforcing members is
At least a portion of the first reinforcing member where stress concentration due to torsion of the torsion beam is generated is located inside a welding range surrounded by a weld line where the corresponding second reinforcing member is welded to the torsion beam. In this way, it is welded to the torsion beam.

If it does in this way, even if it will be a case where a twist arises in a torsion beam, the inside of the welding range surrounded by a welding line will become difficult to twist by the 2nd reinforcement member.
In the torsion beam type suspension, the first reinforcing member is welded to the torsion beam at the portion where the torsion beam is difficult to be twisted. The concentration of stress on the part that was damaged is alleviated.

Further, in the torsion beam type suspension, stress due to torsion of the torsion beam is distributed to the first reinforcing member and the second reinforcing member, so that the roll rigidity is also improved.
Therefore, the torsion beam type suspension is less likely to break due to stress concentration, and the roll rigidity is improved.

The weld line is not necessarily continuous, and may be discontinuous.
By the way, each 1st reinforcement member is the front-end | tip of the side in which the part which the stress concentration generate | occur | produces among the welding parts of a 1st reinforcement member and a torsion beam generate | occur | produces in the said 1st reinforcement member. As a rule of thumb, it is known that it is located in a quarter portion along the longitudinal direction of the torsion beam.

For this reason, each first reinforcing member has a pair of first reinforcing members located within the range surrounded by the welded line-like portion where the corresponding second reinforcing member is welded to the torsion beam. It may be welded to the torsion beam so that a quarter portion is located along the longitudinal direction of the torsion beam from the tip on the side.

In addition, each first reinforcing member is positioned with respect to the torsion beam so that the entire first reinforcing member is positioned inside a range surrounded by a welded line portion where the corresponding second reinforcing member is welded to the torsion beam. It may be welded.

Next, the first reinforcing member and the torsion beam are notched portions formed over the first reinforcing member and the torsion beam, and include a notch portion that grips the outer surface of the trailing arm in the range of 180 degrees or more around the axis. The trailing arm, the torsion beam, and the first reinforcing member may be welded via the notch.

In this way, the trailing arm and the torsion beam can be structurally coupled, so that the trailing arm and the torsion beam can be firmly connected.

Next, the torsion beam may be a member formed in a bowl shape having an opening facing downward.
In this way, since the torsion beam can be formed by bending the sheet metal, the torsion beam type suspension can be manufactured at low cost.

Also, if this torsion beam is used, it is possible to produce a torsion beam by bending a sheet metal even in an area where there is no technology for forming a cylindrical torsion beam.

The first reinforcing member and the second reinforcing member may be formed by bending a plate member.

FIG. 1A is a perspective view of a torsion beam suspension in one embodiment, and FIG. 1B is a cross-sectional view taken along the line IB-IB in FIG. 1A. It is II-II sectional drawing in FIG. 1A. FIG. 3A is a plan view of the torsion beam suspension according to the embodiment, and FIG. 3B is a front view of the torsion beam suspension when the torsion beam suspension according to the embodiment is viewed from the rear side in the vehicle traveling direction. It is a top view of one modification of a torsion beam type suspension, and is a partial view showing only a portion where a left trailing arm and a torsion beam are connected. It is a top view of another modification of a torsion beam type suspension, and is a partial view showing only a portion where a left trailing arm and a torsion beam are connected.

DESCRIPTION OF SYMBOLS 1 ... Torsion beam suspension 2 ... Trailing arm 3 ... Torsion beam 4 ... 1st reinforcement member 5 ... 2nd reinforcement member 6 ... Notch part 20 ... Collar 21 ... Carrier 30 ... Notch 40 ... Notch

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1A, the torsion beam suspension 1 of the present embodiment includes a pair of trailing arms 2 and a torsion beam 3 that connects these trailing arms 2.

Each trailing arm 2 is formed by bending a hollow pipe having a circular cross section. The pair of trailing arms 2 are formed symmetrically with each other.
A collar 20 is fixed to one end of each trailing arm 2 by welding. Each trailing arm 2 is supported by a vehicle body (not shown) via the collar 20 so as to be swingable.

A carrier 21 is fixed to the other end of each trailing arm 2 by welding. A wheel (not shown) is rotatably supported by the trailing arm 2 via the carrier 21.
As shown in FIG. 1B, the torsion beam 3 is formed in a bowl shape, and is a member formed by bending a plate member so that a cross-sectional shape thereof becomes a V shape or a U shape. The torsion beam 3 is disposed so as to open toward the lower side of the vehicle body. For this reason, the shape of the torsion beam 3 is also called a saddle shape.

As shown in FIG. 2, notches 30 are formed at both ends of the torsion beam 3 in the axial direction. Each notch 30 is formed in an arc shape along the shape of the outer surface of the trailing arm 2.

As shown in FIGS. 3A and 3B, the torsion beam 3 is welded with a first reinforcing member 4 (gusset) and a second reinforcing member 5 (reinforce) at both ends in the axial direction.

Each first reinforcing member 4 is a member formed by bending a plate member by pressing or the like and formed in a U-shaped cross section that opens downward, and is a torsion beam opposite to the opening side of the torsion beam 3. 3 is welded onto the upper outer surface.

As shown in FIG. 3A, each first reinforcing member 4 is formed so that the width of its cross-sectional shape gradually decreases from the trailing arm 2 side toward the torsion beam 3 side (tip end side).

Further, as shown in FIG. 2, each first reinforcing member 4 is formed with a notch 40 at an end portion on the side from the torsion beam 3 toward the trailing arm 2 (hereinafter referred to as “rear end side”). Each notch 40 is formed in an arc shape along the shape of the outer surface of the trailing arm 2.

The notches 40 formed in the first reinforcing members 4 and the notches 30 formed at both axial ends of the torsion beam 3 form continuous notches 6 along the outer surface of the trailing arm 2. .

Each notch 6 is formed to have a size for gripping the outer surface of the trailing arm 2 within a range of 180 degrees or more around the axis.
In the present embodiment, the trailing arm 2, the torsion beam 3, and the first reinforcing member 4 come into contact with each other through the notches 6, and the contacted parts are welded to connect them. .

Further, as shown in FIGS. 3A and 3B, the first reinforcing member 4 comes into contact with the torsion beam 3 at the portion corresponding to the edge of the plate member, and the portion with which the edge contacts is welded. To be welded to the torsion beam 3.

The second reinforcing member 5 is a member obtained by bending a plate member by pressing or the like, like the first reinforcing member 4, and is welded to the side surface above the torsion beam 3 among the inner surfaces of the torsion beam 3.

Further, the second reinforcing member 5 is formed so that the width of the cross-sectional shape gradually decreases from the trailing arm 2 side toward the torsion beam 3 side, similarly to the first reinforcing member 4.

However, the second reinforcing member 5 is formed longer than the first reinforcing member 4, and the position of the tip in the direction from the trailing arm 2 side toward the torsion beam 3 side is the position of the second reinforcing member 5. It is welded so that the direction is far from the first reinforcing member 4.

The second reinforcing member 5 is formed wider than the first reinforcing member 4.
The second reinforcing member 5 is arranged so that the portion corresponding to the edge of the plate member abuts against the trailing arm 2 and the torsion beam 3, and the portion where the edge abuts is welded to the tray. It is welded to the ring arm 2 and the torsion beam 3.

Since the second reinforcing member 5 is wider than the first reinforcing member 4 and the length along the axial direction of the torsion beam 3 is also longer than the first reinforcing member 4, the second reinforcing member 5 is welded to the torsion beam 3. The welding is performed so that the first reinforcing member 4 is located inside the range surrounded by the welding line 100 at the time.

For this reason, in the torsion beam type suspension 1 of the present embodiment, even if the torsion beam is twisted, the inside of the range surrounded by the weld line 100 is hardly twisted by the second reinforcing member 5.

And the 1st reinforcement member 4 is welded to the torsion beam 3 through the part which became difficult to twist.
Therefore, in this torsion beam type suspension 1, a portion where stress concentration caused by torsion of the torsion beam 3 occurs in the welded portion between the first reinforcing member 4 and the torsion beam 3 (indicated by reference numeral 200 shown in FIG. 3A). The stress concentration on the portion corresponding to the stress concentration portion is alleviated.

Moreover, in this embodiment, since the stress accompanying the twist of the torsion beam 3 is distributed to the first reinforcing member 4 and the second reinforcing member 5, the roll rigidity is also improved.
Therefore, according to the torsion beam suspension 1 of the present embodiment, breakage due to stress concentration is unlikely to occur, and roll rigidity can be increased.

[Other Embodiments]
(1) The torsion beam suspension 1 described in the above embodiment is merely an example, and the present invention is not limited to this.

(2) In the above embodiment, the example using the saddle-shaped torsion beam 3 has been described. However, a torsion beam 3 having a shape other than this (for example, a cylindrical shape) may be used.
(3) In the above-described embodiment, the first reinforcing member 4 and the second reinforcing member 5 having a size in which the entire first reinforcing member 4 is positioned inside the welding range of the second reinforcing member 5 are used. The reinforcing member 4 and the second reinforcing member 5 are not limited to this. It is only necessary that the portion where the stress concentration occurs is at least within the welding range.

For example, the portion where the stress concentration occurs is a ¼ portion from the front end portion to the rear end side of the first reinforcing member 4, and as shown in FIG. 4, at least this portion (reference numeral 300 in FIG. 4). (The portion indicated by) may fall within the welding range.

(4) In the above embodiment, the first reinforcing member 4 has been described as a member having a rounded tip, but the first reinforcing member 4 has a straight tip as shown in FIG. May be.

In this case, since the stress generated by the twist is generated in the corner portions 400 on both sides of the tip portion, the corner portions 400 may be positioned within the welding range of the second reinforcing member 5.
(5) In the above embodiment, each notch 6 is formed to a size that allows the outer surface of the trailing arm 2 to be gripped in the range of 180 degrees or more around the axis. It is not limited to.

(6) In the above embodiment, the portion where the notch 40 is formed is directly welded. However, a flange is provided along the notch 40 and the flange is welded to attach the first reinforcing member 4 to the trailing arm 2. You may make it join.

Claims (7)

A pair of trailing arms;
A torsion beam connected to each of the trailing arms at both ends in the axial direction;
A pair of first reinforcing members welded across the outer surface of the torsion beam and the respective trailing arms at both axial end portions of the torsion beam, wherein the outer edge portions of the first reinforcing members are welded. A pair of first reinforcing members fixed to the torsion beam and each trailing arm;
A pair of second reinforcing members welded across the inner surface of the torsion beam and each trailing arm at both axial end portions of the torsion beam, and outer edges of the second reinforcing members are welded. A pair of second reinforcing members fixed to the torsion beam and each of the trailing arms,
With
Each of the first reinforcing members is
At least a portion of the first reinforcing member where stress concentration due to torsion of the torsion beam is generated is located inside a welding range surrounded by a weld line where the corresponding second reinforcing member is welded to the torsion beam. A torsion beam suspension that is welded to the torsion beam. The torsion beam suspension according to claim 1,
Each of the first reinforcing members is
From the front end portion of the first reinforcing member on the side where the paired first reinforcing member is located inside the range surrounded by the welded line-like portion where the corresponding second reinforcing member is welded to the torsion beam A torsion beam suspension that is welded to the torsion beam so that a quarter portion is located along the longitudinal direction of the torsion beam. In the torsion beam suspension according to any one of claims 1 to 2,
Each of the first reinforcing members is
A torsion beam type in which the corresponding second reinforcing member is welded to the torsion beam so that the entirety of the first reinforcing member is located inside a range surrounded by a welded line portion welded to the torsion beam. suspension. In the torsion beam type suspension according to any one of claims 1 to 3,
The first reinforcing member and the trailing arm are:
A cutout portion formed across the first reinforcing member and the trailing arm, the cutout portion gripping an outer surface of the trailing arm in a range of 180 degrees or more around an axis, and through the cutout portion A torsion beam type suspension in which the trailing arm, the torsion beam and the first reinforcing member are welded. In the torsion beam suspension according to any one of claims 1 to 4,
The torsion beam is
A torsion beam suspension formed in a bowl shape having an opening facing downward. The torsion beam suspension according to any one of claims 1 to 5,
The first reinforcing member is a torsion beam suspension formed by bending a plate member. In the torsion beam type suspension according to any one of claims 1 to 6,
The second reinforcing member is a torsion beam suspension formed by bending a plate member.

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