JP2014097772A - Torsion beam type suspension for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torsion beam type suspension for a vehicle that can easily form a flange-like flange supporting portion at one end of a boss without occurence of cracks and prevent deformation of a flange of an outer cylinder of a bush.SOLUTION: A torsion beam type suspension 1 for a vehicle is configured by: connecting a pair of left and right tray ring arms 2 to a front end of which is bound a cylindrical boss 4, with a torsion beam arranged in a vehicle width direction; slidably supporting the left and right tray ring arms 2 in a vehicle body side bracket 51 through a bush 5 to be inserted into the boss 4 bound to the front end; and forming a flange 5b1 in the outer periphery of one end of an outer cylinder 5b of the bush 5. The boss 4 is cylindrically molded by rounding a plate material, butting ends of the material and welding the butted part, and also the diameter of one end in a shaft direction thereof is increased to form a flange supporting portion 4a and then the flange supporting portion 4a is contacted with the flange 5b1 of the outer cylinder 5b.

Description

  The present invention relates to a torsion beam suspension for a vehicle in which a pair of left and right trailing arms are connected by a torsion beam arranged in the vehicle width direction.

  For example, a torsion beam suspension is used as a rear suspension for a front-wheel drive vehicle. In this torsion beam suspension, a pair of left and right trailing arms with a cylindrical boss attached to the front end are connected by a torsion beam arranged in the vehicle width direction, and the left and right trailing arms are inserted into the front end boss. It is supported by a bracket on the vehicle body through a bushing that can swing. The bush is configured by filling an elastic body between an inner cylinder and an outer cylinder, and a flange for transmitting a force to the bracket via the elastic body is provided on an outer periphery of one end of the outer cylinder of the bush. Formed and configured. Here, the structure of the boss part at the tip of the left and right trailing arms of the conventional torsion beam suspension will be described with reference to FIGS.

  6 is a plan sectional view of a boss portion of a conventional trailing arm suspension. FIG. 7 is an enlarged detail view of a portion C in FIG. 6. A pair of left and right trailing arms 102 (only one is shown in FIG. 6). Cylindrical bosses 104 are respectively attached to the front ends, and bushes 105 are inserted into the bosses 104, respectively. Here, each bush 105 is configured by filling (baking) an elastic body 105c such as rubber between a metallic inner cylinder 105a and an outer cylinder 105b that are concentrically arranged, and vibration from the road surface, etc. Is transmitted to the vehicle body by the elastic body 105c.

  In addition, brackets 151 (only one is shown in FIG. 6) that are open toward the rear of the vehicle are attached to the left and right sides of the vehicle body. The front ends of the left and right trailing arms 102 are attached by bolts 108 through bushes 105 inserted therethrough, and the trailing arms 102 are attached and supported so as to swing up and down.

  Incidentally, a flange-like stopper 105c1 that is in contact with the inner surface of the bracket 151 is integrally formed at the inner end portion of the elastic body 105c of the bush 105, and this stopper 105c1 is formed at the inner end portion of the outer cylinder 105b. It is received by the flange 105b1. The flange 105 b 1 of the outer cylinder 105 b of the bush 105 is received by the inner end face of the boss 104. With this configuration, when the vehicle turns to the right, for example, the lateral force acting on the rear wheel causes the flange 105b1 formed on the outer cylinder 105b of the bush 105 from the boss 104 via the left trailing arm 102. Then, it is applied to the stopper 105c1 of the elastic body 105c, and the lateral force is finally received by the vehicle body via the bracket 151.

JP 2007-137087 A

  By the way, conventionally, the boss 104 is made of a pipe material having a constant inner and outer diameter, and the outer diameter of the flange 105b1 of the outer cylinder 105b of the bush 105 ensures a contact area of the stopper 105c1 of the elastic body 105c with the bracket 151. Therefore, it is set larger than the outer diameter of the boss 104. For this reason, as shown in detail in FIG. 7, the flange 105 b 1 of the outer cylinder 105 b of the bush 105 protrudes radially outward from the boss 104, and this protruding portion is not received by the boss 104. Therefore, there is a possibility of deformation due to contact with the inner surface of the bracket 151.

  Therefore, it is considered that one end of the boss 104 is expanded in a trumpet shape to form a flange-shaped flange support portion, and this flange support portion is brought into contact with the entire flange formed on the outer cylinder of the bush. It is not easy to form a flange support part by expanding one end of the boss 4 made of the above, and problems such as cracking of the flange support part occur.

  The present invention has been made in view of the above problems, and the object of the present invention is to easily form a flange-shaped flange support portion at one end of the boss without causing cracks, and the flange support portion allows the outer cylinder of the bush to be formed. An object of the present invention is to provide a torsion beam suspension for a vehicle that can receive the entire flange and prevent deformation of the flange.

In order to achieve the above object, the invention according to claim 1 is characterized in that a pair of left and right trailing arms each having a cylindrical boss bound to the front end are connected by a torsion beam disposed in the vehicle width direction, and the left and right trailing rings are connected. The arm is supported swingably on the bracket on the vehicle body side via a bush inserted through the boss at the front end thereof,
A vehicle in which a flange for transmitting a force to the bracket via the elastic body is formed on an outer periphery of one end of the outer cylinder of the bush configured by filling an elastic body between an inner cylinder and an outer cylinder. In the torsion beam suspension,
The boss is formed into a cylindrical shape by rounding a plate material, butting ends thereof, and welding the butted portions, and expanding the diameter of one end in the axial direction to form a flange support portion. Is brought into contact with the flange of the outer cylinder.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, a notch is formed at one end of the butted portion of the boss on the flange support portion side.

  According to the first aspect of the present invention, the boss is formed into a cylindrical shape by rounding the plate material, butting the ends of the bosses, and welding the butted portions. The flange support portion can be easily formed without causing cracks. And since this flange support part was made to contact | abut to the flange of the outer cylinder of a bush, the whole flange of the outer cylinder of a bush is supported by the flange support part of a boss, and the lateral force from a rear wheel is the flange of an outer cylinder from a boss. Even if it acts on, the deformation of the flange is prevented. As a result, the lateral force is reliably transmitted from the flange of the outer cylinder to the bracket on the vehicle body via the elastic body, the performance of the torsion beam suspension can be improved, and the plate thickness of the flange of the outer cylinder can be reduced. It is possible to reduce weight and improve productivity. Further, since the flange support portion of the boss functions as a stopper when the bush is press-fitted, the press-fitting work of the bush to the boss is facilitated.

  According to the second aspect of the present invention, since the notch is formed at one end of the boss butting portion on the flange support portion side, the flange support portion is not formed in the notch portion, and the flange support is provided in a portion other than the notch. The part can be formed more easily. And, if the tip of the trailing arm is welded to both sides of the boss abutting portion, the joining strength of the boss abutting portion is enhanced by the trailing arm, so that the durability of the torsion beam suspension is improved. Enhanced. In the flange support portion of the boss, excessive force acts on the opposite side (front side of the vehicle) to the welded portion between the boss and the trailing arm (the portion where the notch is formed in the boss butting portion). Even if the notch is formed in the butt-matching portion, there is no particular problem, and the weight of the boss can be reduced by the notch.

1 is a plan view of a torsion beam suspension of a vehicle according to the present invention. FIG. 2 is a detailed cross-sectional view of a part A in FIG. 1. It is the B section enlarged detail drawing of FIG. It is a perspective view of the boss | hub of the torsion beam type suspension of the vehicle which concerns on this invention. It is the fragmentary perspective view which looked at the one side front end part of the torsion beam type suspension of the vehicle concerning the present invention from the vehicle width direction inside. It is a plane sectional view of a boss portion of a conventional trailing arm type suspension. It is the C section enlarged detail drawing of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a plan view of a torsion beam suspension of a vehicle according to the present invention, FIG. 2 is a detailed sectional view of part A of FIG. 1, FIG. 3 is an enlarged detailed view of part B of FIG. FIG. 5 is a partial perspective view of the front end portion on one side of the torsion beam suspension as viewed from the inner side in the vehicle width direction.

  A torsion beam type suspension 1 according to the present invention supports left and right rear wheels of a vehicle so as to be swingable up and down with respect to a vehicle body 50. As shown in FIG. A pair of left and right trailing arms 2 extending in the direction) are connected by a torsion beam 3 arranged in the vehicle width direction (left and right direction in FIG. 1).

  Cylindrical bosses 4 are welded to the respective ends of the pair of left and right trailing arms 2, and bushes 5 are respectively fitted into the bosses 4 by press-fitting as shown in FIG. Here, each bush 5 is configured by filling (baking) an elastic body 5c such as rubber between a metallic inner cylinder 5a and an outer cylinder 5b that are concentrically arranged, and vibrations from a road surface, etc. Is transmitted to the vehicle body by the elastic body 5c.

  As shown in FIG. 2, a flange-like stopper 5c1 that abuts against the inner surface of a bracket 51, which will be described later, is integrally formed at the inner end of the elastic body 5c of each bushing 5. It is received by a flange 5b1 formed at the inner end of the cylinder 5b.

  Thus, in the present embodiment, the boss 4 is formed into a cylindrical shape by rolling the plate material, butting the end portions together as shown in FIG. 4, and welding the butted portion 4A. In this way, one end (inner end) in the axial direction of the boss 4 formed into a cylindrical shape by bending and welding is formed with a flange support portion 4a having a flange-like diameter expanded outwardly in the radial direction by bending. As shown in FIGS. 2 and 3, the flange support portion 4 a is in contact with the entire back surface of the flange 5 b 1 of the outer cylinder 5 b of the bush 5. In other words, the inner end portion of the boss 4 that is the left and right center side of the vehicle is expanded radially outward to form a bowl-shaped receiving surface that becomes the flange support portion 4a, and is brought into contact with the entire rear surface of the flange 5b1 to The force from 4 is applied to the entire flange 5b1.

  Further, as shown in FIG. 4, a U-notch-shaped notch 4a1 is formed at one end of the butted portion 4A of the boss 4 on the flange support portion 4a side (inner end side) by notching the butted end portion. As shown in FIG. 5, the front ends of the left and right trailing arms (only one is shown in FIG. 5) are welded to both sides of the boss 4 butt portion 4 </ b> A. Therefore, the boss 4 is welded to each trailing arm in a state where the notch 4a1 formed in the flange support portion 4a is located on the side where the trailing arm 2 extends (the vehicle rear side). That is, when the boss 4 is viewed from the axial direction, the notch 4a1 is formed in the flange support portion 4a that overlaps the trailing arm 2 on the side where the trailing arm 2 of the boss 4 extends (the rear side of the vehicle). Is formed. Further, as shown in FIG. 1, shock absorber mounting shafts 6 that protrude horizontally inward are respectively attached to the rear end portions of the left and right trailing arms 2. 6, the lower ends of left and right shock absorbers (not shown) are respectively attached. A spindle bracket for attaching a spindle for rotatably supporting the rear wheel is welded to the upper part of the rear end of each of the left and right trailing arms 2. In FIG. 1, reference numeral 7 denotes a spring receiver that receives a lower end of a cushion spring (not shown).

  By the way, in order to ensure high running stability in the vehicle, it is necessary to perform toe control of the rear wheels during steering operation. Specifically, for steering at a slight angle when the vehicle is running, the rear wheel (more precisely, the rear wheel located outside the steering direction) is understeered as a toe-in state. On the other hand, when the running stability is improved and the vehicle is making a hard cornering, the rear wheels are reversed toe-out and the direction of the vehicle is actively changed. For this purpose, the lateral force acting on the torsion beam type suspension 1 as it is steered brings the stopper 5c1 of the bush 5 into contact with the inner surface of the bracket 51, and the bracket 51 is inclined with respect to the lateral direction of the vehicle. The boss 4 is moved in the longitudinal direction of the vehicle along the inner surface of the vehicle, and the position of the left and right bosses 4 in the longitudinal direction of the vehicle is changed to change the posture of the torsion beam suspension 1.

  Therefore, the boss 4 bonded to each end of the left and right trailing arms 2 and the bush 5 press-fitted thereto are inclined outwardly by an angle α shown in the drawing with respect to the vehicle longitudinal direction, as shown in FIG. Is provided. Accordingly, the left and right brackets 51 of the vehicle body 50 are also attached to the vehicle body 50 so as to be inclined by the angle α shown in the drawing with respect to the vehicle longitudinal direction as shown in the drawing.

  As shown in FIG. 1, the brackets 51 are each formed in a substantially horizontal U shape in plan view that opens toward the rear of the vehicle or toward the center of the left and right sides of the vehicle, and the front ends of the trailing arms 2 are formed therein. 2 and a bush 5 press-fitted into the boss 4 are fitted as shown in FIG. Then, a bolt 8 is passed from the outer side to each of the left and right brackets 51 and the inner cylinder 5a of the bush 5 fitted therein, and a nut 9 that is screwed into an end portion projecting inward from the bracket 51 of the bolt 8. The front end portions of the left and right trailing arms 2 are supported by the bracket 51 via the bush 5 so as to be swingable up and down. Accordingly, the left and right rear wheels rotatably supported by the rear end portions of the left and right trailing arms 2 swing up and down with respect to the vehicle body 50 around the bolt 8, but the relative displacement of the left and right rear wheels is caused by the torsion beam. 3 is controlled by the torsional resistance.

  Thus, in the torsion beam suspension 1 according to the present invention configured as described above, the boss 4 is formed into a cylindrical shape by rounding the plate material, butting the ends of each other and welding the butted portion 4A. Therefore, it is possible to easily form the flange support portion 4a without causing cracks by expanding the diameter of one end (inner end) in the axial direction. And since this flange support part 4a was made to contact | abut to flange 5B1 of the outer cylinder 5b of the bush 5, the whole flange 5b1 of the outer cylinder 5b of the bush 5 was supported by the flange support part 4a of the boss | hub 4, and from the rear wheel Even if the lateral force acts on the flange 5b1 of the outer cylinder 5b from the boss 4 and the stopper 5c1 strongly contacts the bracket 51, deformation of the flange 5b1 is prevented. As a result, the lateral force is reliably transmitted from the flange 5b1 of the outer cylinder 5b to the bracket 51 on the vehicle body 50 side through the elastic body 5c, and the performance of the torsion beam suspension 1 is improved, and the flange 5b1 of the outer cylinder 5b is improved. The plate thickness can be reduced, and weight reduction and productivity improvement can be achieved. Further, since the flange support portion 4a of the boss 4 functions as a stopper when the bush 5 is press-fitted, an effect of facilitating the press-fitting work of the bush 5 to the boss 4 is also obtained.

  Further, in the torsion beam suspension 1 according to the present invention, the notch 4a1 is formed at one end of the butted portion 4A of the boss 4 on the flange support portion 4a side, and therefore the flange support portion 4a is not formed in the notch 4a1 portion. The flange support portion 4a can be more easily formed at a portion other than the notch 4a1. And in this Embodiment, since each front-end | tip of the left and right trailing arms 2 was welded to the both sides of the abutting portion 4A of the boss 4 respectively, the joining strength of the abutting portion 4A of the boss 4 is trailing. The arm 2 increases the durability of the torsion beam suspension 1. Note that, in the boss 4 flange support portion 4a, an excessive force is generated when the trailing arm 2 swings up and down with the stopper 5c1 of the bush 5 strongly contacting the inner surface of the bracket 51. Because this occurs in the front side portion of the boss 4, it acts on the opposite side (vehicle front side) to the welding location between the boss 4 and the trailing arm 2 (location where the notch 4 a 1 is formed in the butted portion 4 A of the boss 4). Even if the notch 4a1 is formed in the butt portion 4A of the boss 4, there is no particular problem, and the weight of the boss 4 can be reduced by the notch 4a1.

DESCRIPTION OF SYMBOLS 1 Torsion beam type suspension 2 Trailing arm 3 Torsion beam 4 Boss 4A Boss butt part 4a Boss flange support part 5 Bush 5a Bush inner cylinder 5b Bush outer cylinder 5b1 Outer cylinder flange 5c Bush elastic body 50 Car body 51 Bracket

Claims (2)

A pair of left and right trailing arms with a cylindrical boss bound to the front end are connected by a torsion beam arranged in the vehicle width direction, and the vehicle body is connected to the left and right trailing arms through a bush that passes through the front end boss. It is supported on the side bracket so that it can swing,
A vehicle in which a flange for transmitting a force to the bracket via the elastic body is formed on an outer periphery of one end of the outer cylinder of the bush configured by filling an elastic body between an inner cylinder and an outer cylinder. In the torsion beam suspension,
The boss is formed into a cylindrical shape by rounding a plate material, butting ends thereof, and welding the butted portions, and expanding the diameter of one end in the axial direction to form a flange support portion. A torsion beam suspension for a vehicle, wherein the torsion beam suspension is abutted against a flange of the outer cylinder. 2. The torsion beam suspension for a vehicle according to claim 1, wherein a notch is formed at one end of the boss butting portion on the flange support portion side.

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