CN111746216A - Torsion beam type suspension - Google Patents

Abstract

The invention provides a torsion beam type suspension, in the torsion beam type suspension, a welding part is set corresponding to a seat part arranged on an upper wall part of a torsion beam, a bottom wall part is abutted against the seat part and is welded at the welding part, and the seat part is a part of the upper wall part which is arranged in a protruding direction (an upper direction) far away from an inner area of the torsion beam.

Description

torsion beam suspension

technical field

The invention relates to a torsion beam type suspension, in particular to a torsion beam type suspension mounted on vehicles such as four-wheeled vehicles.

Background technique

In recent years, as a suspension device for a vehicle such as a four-wheeled vehicle, a torsion beam type suspension, which has a small number of components, a relatively simple structure, and excellent space efficiency, has been widely used mainly in small-displacement vehicles.

This torsion beam type suspension is required to ensure required strength and rigidity while suppressing unnecessary influence on the productivity, etc. Therefore, it has been proposed to connect the left and right trailing arms and The structure of the torsion beam.

In this case, the specification of European Patent Application Publication No. 2896522 relates to a motor vehicle axle 1, which discloses the following structure: the motor vehicle axle 1 is provided with two longitudinal supports (trailing arms) 3 which extend along the vehicle The transverse support body 2, which extends in the transverse direction of the vehicle and combines the two trailing arms 3 with each other; and the reinforcing sheet 4, which respectively combines the two trailing arms 3 and the transverse support body 2, In the end region 10 of the reinforcement sheet 4 on the side of the lateral support body 2 , a point-like joint 11 such as plug welding is provided to join the bottom web 7 of the metal profile 5 of the lateral support body 2 and the reinforcement sheet 4 .

SUMMARY OF THE INVENTION

However, according to the study of the present inventors, in the structure of the specification of European Patent Application Laid-Open No. 2896522, by providing the point-like joint portion 11, the force acting on the joint portion is better distributed, thereby intending to reduce the pressure on the reinforcing sheet 4. The stress is generated in the terminal region 10 on the side of the lateral support 2, but the point-shaped joints 11 are arranged relative to the oval or long hole extending in the longitudinal direction of the vehicle, and are connected with the flat plate in the metal profile 5 of the lateral support 2. The bottom web 7 is combined, so there is a natural limit to the degree of stress reduction, and there is room for improvement in this regard.

In addition, according to the research of the present inventors, in the torsion beam type suspension, it is required to optimize the torsional rigidity of the torsion beam while ensuring the joint strength between the torsion beam and the trailing arm and the bending rigidity of the torsion beam. When the torsion beam and the trailing arm are connected by a reinforcing member in order to enhance the joint strength of the torsion beam and the flexural rigidity of the torsion beam, especially if the structure of the reinforcing member is adjusted to adjust the torsional rigidity of the torsion beam, stress concentrates on the torsion beam. The tendency of the joint portion with the reinforcing member becomes stronger. That is, in this case, the degree of freedom of design in optimizing the torsional rigidity of the torsion beam is limited to a low level, and it is currently expected that the degree of freedom of design in optimizing the torsional rigidity of the torsion beam will be improved. new structure.

The present invention has been accomplished through the above studies, and an object of the present invention is to provide a torsion beam type suspension capable of securing the joint strength between the torsion beam and the trailing arm when the torsion beam and the trailing arm are connected by a reinforcing member The torsion characteristics of the torsion beam can be set with a high degree of freedom in such a manner that the bending rigidity of the torsion beam and the torsion beam are suppressed, and the concentration of stress on the joint portion of the torsion beam and the reinforcing member is suppressed.

In order to achieve the above object, the torsion beam type suspension in the first aspect of the present invention includes: a left trailing arm extending in the longitudinal direction of the vehicle body on the left side in the width direction of the vehicle body, and extending in the longitudinal direction of the vehicle body The front side is supported on the vehicle body, and the wheels are supported on the rear side in the longitudinal direction; the right trailing arm extends along the longitudinal direction on the right side in the width direction and is on the front side in the longitudinal direction. The vehicle body is supported on the vehicle body, and the wheel is supported on the rear side in the longitudinal direction. an open cross-sectional shape having a pair of wall portions facing each other and a connecting wall portion connecting the pair of wall portions, and connecting the left trailing arm and the right trailing arm; The left side extends in the width direction, and has an inner left attachment portion that is attached to the torsion beam in an inner region surrounded by the pair of wall portions and the connecting wall portion of the torsion beam ; an outer left mounting portion, which is mounted on the left trailing arm; and a middle left connecting portion, which connects the inner left mounting portion and the outer left mounting portion, and the left reinforcing member connects the torsion force a beam and the left trailing arm; and a right stiffener extending in the width direction on the right side and having: an inner right mounting portion mounted to the torsion beam in the inner region; an outer right an installation part, which is installed on the right trailing arm; and a middle right connecting part, which connects the inner right installation part and the outer right installation part, and the right reinforcement connects the torsion beam and the the right trailing arm, the torsion beam has in the connecting wall part: a left seat part, which is configured with a left welding part, in the left welding part, the inner left mounting part is welded to the connecting wall part; and a right seat portion provided with a right welding portion in which the inner right mounting portion is welded to the connecting wall portion, the left seat portion being the distance from the connecting wall portion to the inner region The right seat part is the part of the connecting wall part that protrudes in the protruding direction.

In addition, the second aspect of the present invention is based on the first aspect, wherein the left welding portion is disposed at a left plug welding hole provided in one of the connecting wall portion and the inner left mounting portion, so The left plug welding hole is a pair of long holes with different diameters of arcs opposite to each other in a direction perpendicular to the protruding direction, and the right welding portion is disposed on the connecting wall portion and the inner right mounting portion. In one of the right plug welding holes, the right plug welding holes are long holes with different diameters of a pair of arcs facing each other in a direction perpendicular to the protruding direction.

In addition, in the third aspect of the present invention, based on the second aspect, the left plug welding hole is provided in the inner left mounting portion, and the right plug welding hole is provided in the inner right mounting portion.

In addition, based on the third aspect of the present invention, the fourth aspect is that the left seat portion has a portion recessed toward the inner region in such a manner that a portion of the left seat portion enters the left plug welding hole, and the right seat portion is recessed toward the inner region. The portion has a portion recessed toward the inner region in such a way that a portion thereof enters the right plug welding hole.

In addition, in the fifth aspect of the present invention, based on the second aspect, the left plug welding hole is provided in the left seat portion, and the right plug welding hole is provided in the right seat portion.

In addition, in the sixth aspect of the present invention, based on the third aspect, the inner left mounting portion has a portion recessed toward the inner region in such a manner that a portion of the inner left mounting portion is away from the left plug welding hole, and the inner left mounting portion is recessed toward the inner region. The right mounting portion has a portion recessed toward the inner region such that a portion thereof is away from the right plug welding hole.

In addition, the present invention is based on any one of the first to sixth aspects, and a seventh aspect is that, in the inner left mounting portion, the inner left mounting portion is arranged to extend from the right end portion of the inner left mounting portion to the outer side. A left flat wall portion is provided in a manner that the left mounting portion is laterally offset and is separated from the connecting wall portion, and the left flat wall portion is a portion of the inner left mounting portion that is recessed toward the connecting wall portion, and is provided with a left flat wall portion. The right end portion of the inner left mounting portion and the left flat wall portion are connected by a left inclined wall portion, and in the inner right mounting portion, from the left end portion of the inner right mounting portion to the outside A right flat wall portion is provided in a manner that the right mounting portion is laterally offset and is separated from the connecting wall portion, and the right flat wall portion is a portion of the inner right mounting portion that is recessed toward the connecting wall portion, and is provided with a right flat wall portion. The left end portion of the inner right mounting portion and the right flat wall portion are connected by a right inclined wall portion.

In addition to the seventh aspect of the present invention, an eighth aspect of the present invention resides in that the portion on the front side of the right end portion of the left flat wall portion and the portion on the rear side of the right end portion have respective The right protruding portion protruding from the right side, the portion on the front side of the left end portion of the right flat wall portion and the portion on the rear side of the left end portion have left protruding portions extending toward the left side, respectively. extension.

According to the structure of the first aspect of the present invention, the torsion beam has, in the connecting wall portion, the left seat portion provided with the left welding portion at which the inner left mounting portion of the left reinforcement member is welded to the connecting wall portion ; and a right seat portion, which is provided with a right welding portion in which the inner right mounting portion of the right reinforcement is welded to the connecting wall portion, the left seat portion being the projection of the connecting wall portion toward the inner region away from the torsion beam The part protruding in the direction, the right seat part is the part where the connecting wall part protrudes in the protruding direction away from the inner region of the torsion beam, and thus, when the torsion beam and the trailing arm are connected by the reinforcing member, the height including the left seat can be improved. The rigidity of the connecting wall portion of the torsion beam and the right seat portion disperses the force that should be applied to the joint portion of the torsion beam and the reinforcing member, thereby ensuring the joint strength of the torsion beam and the trailing arm and the bending rigidity of the torsion beam, and The torsional characteristics of the torsion beam can be set with a high degree of freedom by suppressing stress concentration in the joint portion of the torsion beam and the reinforcement member.

Further, according to the structure in the second aspect of the present invention, the left welding portion is disposed at the left plug welding hole provided in one of the connecting wall portion and the inner left mounting portion, and the left plug welding hole is in a direction perpendicular to the protruding direction. A pair of long holes with different diameters of arcs facing each other, the right welding part is arranged at the right plug welding hole provided on one of the connecting wall part and the inner right mounting part, and the right plug welding hole is perpendicular to the protruding direction. A pair of long holes with different diameters of arcs facing each other in the direction of each other can reliably suppress stress concentration at the joint portion of the torsion beam and the reinforcing member, and can set the torsional characteristics of the torsion beam with a high degree of freedom.

In addition, according to the configuration of the third aspect of the present invention, the left plug welding hole is provided in the inner left mounting portion, and the right plug welding hole is provided in the inner right mounting portion, whereby the left reinforcement member and the right side generally facing downward of the vehicle can be reinforced. By setting the welded part on the part side, it is possible to reliably prevent stress from concentrating on the joint part of the torsion beam and the reinforcing member, and at the same time, prevent the occurrence of dust, moisture, etc. staying on the welded part.

In addition, according to the structure of the fourth aspect of the present invention, the left seat has a portion recessed toward the inner region such that a portion thereof enters the left plug welding hole, and the right seat has a portion facing inward such that a portion thereof enters the right plug welding hole It is possible to set through holes that function as drainage holes in the recessed parts, and to improve the rigidity of the left seat and right seat, and to reliably suppress the concentration of stress on the torsion beam and the reinforcement The combined part of the part.

In addition, according to the configuration of the fifth aspect of the present invention, the left plug welding hole is provided in the left seat portion, and the right plug welding hole is provided in the right seat portion, whereby a portion that is generally covered by the peripheral member on the relatively upper side of the vehicle can be By setting the welded portion, it is possible to reliably prevent stress from concentrating on the joint portion of the torsion beam and the reinforcing member, and to prevent foreign matter such as debris from coming into contact with the welded portion while the vehicle is running.

In addition, according to the structure of the sixth aspect of the present invention, the inner left mounting portion has a portion recessed toward the inner region such that a portion thereof is away from the left plug welding hole, and the inner right mounting portion has a portion thereof that is away from the right plug welding hole Parts recessed toward the inner area allow through holes that function as drain holes to be set in these recessed parts, while increasing the rigidity of the inner left mounting portion and the inner right mounting portion, and reliably suppressing stress concentration in The joint part of the torsion beam and the reinforcement member.

Further, according to the configuration in the seventh aspect of the present invention, the inner left mounting portion is provided with the inner left mounting portion offset from the right end portion of the inner left mounting portion to the outer left mounting portion side and facing away from the connecting wall portion. The left flat wall portion is the part where the inner left mounting portion is recessed toward the connecting wall portion, and the right end portion of the inner left mounting portion and the left flat wall portion are connected by the left inclined wall portion, and the inner right The mounting portion is provided with a right flat wall portion that is offset from the left end portion of the inner right mounting portion to the outer right mounting portion side and faces away from the connecting wall portion, and the right flat wall portion is the inner right mounting portion facing the connecting wall. The left end portion of the inner right mounting portion and the right flat wall portion are connected by the right inclined wall portion, so that the rigidity of the inner left mounting portion and the inner right mounting portion can be improved, and the stress can be suppressed reliably. Focus on the joint part of the torsion beam and the reinforcement part.

Further, according to the configuration in the eighth aspect of the present invention, the portion on the front side of the right end portion of the left flat wall portion and the portion on the rear side of the right end portion of the left flat wall portion have right projecting portions projecting to the right, respectively, and the right flat wall portion The front part of the left end part and the rear part of the left end part have left extension parts respectively protruding to the left side, so that the right end part of the inner left mounting part and the left end part of the inner right mounting part can be surrounded. The joint parts increase their rigidity and more reliably suppress the stress concentration in the joint parts of the torsion beam and the reinforcement member.

Description of drawings

FIG. 1 is a partial plan view of a torsion beam suspension in an embodiment of the present invention.

FIG. 2 is a partial rear view of the torsion beam suspension in the present embodiment.

FIG. 3A is a partial bottom view of the torsion beam suspension in the present embodiment.

FIG. 3B is an enlarged view of the plug welding hole in FIG. 3A .

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 1 .

FIG. 5 is a cross-sectional view taken along line B-B of FIG. 1 .

FIG. 6 is a cross-sectional view of a torsion beam suspension according to a modification of the present embodiment, and corresponds to FIG. 4 in position.

FIG. 7 is a cross-sectional view of a torsion beam suspension according to a modification of the present embodiment, and corresponds to FIG. 5 in position.

Label description

1, 1': torsion beam suspension;

10: torsion beam;

11: Front longitudinal wall;

12: rear longitudinal wall;

13: upper wall;

14: seat;

15: depression setting part;

16: through hole;

17: Plug welding hole;

20, 120: trailing arm;

30, 130: reinforcement;

31: bottom wall;

32: front flange;

33: rear flange;

34: plug welding hole;

34a, 34b: arc;

34c, 34d: connecting lines;

35: flat wall part;

36: inclined part;

37: recess setting part;

38: through hole;

39C: middle part;

39F: front extension;

39R: rear extension;

40: External installation part;

50: Internal installation part;

60: Intermediate connecting part;

80, 180: spring seat;

90, 190: shock absorber bracket; 100: collar part;

110: wheel support parts;

W: welding part;

I: inner area;

S: closed section;

B1: body mounting part;

D1: shock absorber installation part;

W1: Wheel side mounting part;

S1: Spring mounting part.

Detailed ways

Hereinafter, the torsion beam type suspension in the embodiment of the present invention including modified examples will be described in detail with reference to FIGS. 1 to 7 as appropriate. In addition, in the figure, the x-axis, the y-axis, and the z-axis constitute a three-axis orthogonal coordinate system. Further, the positive direction of the x-axis is the forward direction of the vehicle body, the positive direction of the y-axis is the left direction of the vehicle body, and the positive direction of the z-axis is the upward direction of the vehicle body. In addition, the direction of the x-axis is sometimes referred to as the longitudinal direction or the front-rear direction, the direction of the y-axis is referred to as the width direction or the left-right direction, and the direction of the z-axis is referred to as the vertical direction.

1 is a partial plan view of the torsion beam type suspension in the present embodiment, FIG. 2 is a partial rear view of the torsion beam type suspension in the present embodiment, and FIG. 3A is a schematic diagram of the torsion beam type suspension in the present embodiment. Partial bottom view, FIG. 3B is an enlarged view of the plug welding hole in FIG. 3A. 4 is a cross-sectional view taken along line A-A of FIG. 1 (a longitudinal cross-sectional view taken along a plane parallel to the y-z plane, that is, a plane perpendicular to the longitudinal direction), and FIG. 5 is a cross-sectional view taken along line B-B of FIG. 1 (with a plane parallel to the x-z plane) A plane, that is, a longitudinal cross-sectional view cut along a plane perpendicular to the width direction). 6 is a cross-sectional view of a torsion beam suspension according to a modification of the present embodiment, which corresponds to FIG. 4 in position, and FIG. 7 is a cross-sectional view of a torsion beam suspension according to a modification of the present embodiment, in position The above is equivalent to Figure 5. 1 to 7 mainly show the components on the left side of the torsion beam suspension, and the components on the right side of the torsion beam suspension have a bilaterally symmetrical structure with respect to the structure on the left side. In addition, in the drawings, for convenience of explanation, the components on the right side of the torsion beam suspension are indicated by reference numerals in parentheses.

First, the structure of the torsion beam type suspension 1 in the present embodiment will be described in detail with reference to FIGS. 1 to 5 .

The torsion beam type suspension 1 is mounted on a vehicle body such as a rear side frame of a motor vehicle (not shown), and supports a suspension spring (hereinafter referred to as a spring), a suspension damper (hereinafter referred to as a damper), and wheels Wait.

Specifically, the torsion beam type suspension 1 mainly includes a torsion beam 10 , a pair of left and right trailing arms 20 , 120 , and a pair of left and right reinforcements 30 , 130 . In addition, the torsion beam type suspension 1 may include a pair of left and right spring seats 80 , 180 and a pair of left and right damper brackets 90 , 190 .

The torsion beam 10 is typically a plate member composed of a metal plate such as a steel plate that protrudes upward by press forming or the like. The torsion beam 10 extends in the width direction and is welded to each other by arc welding or the like. The pair of left and right trailing arms 20 and 120 are connected to both ends.

Specifically, the torsion beam 10 includes a front vertical wall portion 11, a rear vertical wall portion 12, and an upper wall portion 13, which face each other in the front-rear direction, in a longitudinal section cut along a plane perpendicular to the width direction. The upper wall portion 13 connects the respective upper end portions of the front vertical wall portion 11 and the rear vertical wall portion 12 in the front-rear direction, and is provided with a seat portion 14 protruding upward. The inner region I surrounded by the wall portion 12 and the upper wall portion 13 has an open cross-sectional shape that opens downward at the same time. Typically, the front vertical wall portion 11 hangs down slightly obliquely forward from the upper wall portion 13 , and the rear vertical wall portion 12 hangs down slightly obliquely rearward from the upper wall portion 13 . Further, typically, when the torsion beam type suspension 1 is subjected to a static load due to the vehicle weight, it can be considered that the upper wall portion 13 is in a substantially horizontal position. In addition, the torsion beam 10 may have an open cross-sectional shape that is open obliquely downward in the front or obliquely downward in the rear, as required. In addition, the lower end portion of the front vertical wall portion 11 and the lower end portion of the rear vertical wall portion 12 are typically set so as to go from the central portion in the width direction to the left in accordance with the relationship with the required torsional characteristics of the torsion beam 10, respectively. and gradually decreased downwards.

Here, the torsion beam type suspension 1 typically has a substantially bilaterally symmetrical shape with respect to a central plane perpendicular to the width direction and passing through the center of the widthwise direction, so the torsion beam 10 has a bilaterally symmetric shape with respect to the central plane, The seat portion 14 is also provided on the upper wall portion 13 as a pair of left-right symmetrical members. Also, the left and right trailing arms 20 and 120, the left and right stiffeners 30 and 130, the left and right spring seats 80 and 180, and the left and right shock absorber brackets 90 and 190 are respectively relative to the The central planes have shapes that are bilaterally symmetrical to each other, and are arranged at positions symmetrical to each other. Hereinafter, for the convenience of explanation, the left trailing arm 20 is used as the left trailing arm 20 for the left and right trailing arms 20 and 120 , the left and right reinforcement members 30 and 130 , the left and right spring seats 80 and 180 , and the left and right damper brackets 90 and 190 . , The left reinforcement 30 , the left spring seat 80 and the left shock absorber bracket 90 are taken as examples for representative description.

The left trailing arm 20 is typically a tubular plate member made of a metal plate such as a steel plate having a closed cross-sectional shape, and extends in the longitudinal direction.

Specifically, in the left trailing arm 20, a collar member 100, which is typically formed by rolling a metal plate such as a steel plate to be supported on the vehicle body, is welded to its front end by arc welding or the like. On the other hand, in the left trailing arm 20 A wheel support member 110 made of a metal such as a typical steel for supporting the wheel is welded to the rear end portion by arc welding or the like so that a part thereof is inserted. In addition, according to need, the left trailing arm 20 may be constructed by preparing two components formed by forming a flat plate member made of a metal plate such as a steel plate into a substantially U-shaped longitudinal section, and forming these two components so that they are The left trailing arm 20 may be formed of a single pipe member made of metal such as a steel pipe, so as to face each other in the width direction or the vertical direction by welding by arc welding or the like. In addition, the wheel support member 110 may be welded by arc welding or the like so as to only abut against the rear end portion of the left trailing arm 20 .

The left reinforcement 30 is typically a plate member formed of a metal plate such as a steel plate formed by press forming or the like, and is disposed between the torsion beam 10 and the left trailing arm 20 to extend in the width direction, and the left and right end portions thereof are arranged to extend in the width direction. The torsion beam 10 and the left trailing arm 20 are respectively welded to connect them.

Specifically, the left reinforcement 30 includes a bottom wall portion 31 that is a main body portion of a molded product, a front flange 32 erected downward from the front end portion of the bottom wall portion 31 , and downward from the rear end portion of the bottom wall portion 31 . The upright rear flange 33, the front flange 32 and the rear flange 33 respectively extend in the width direction.

The left reinforcement 30 is provided with an outer mounting portion 40 as a left end portion outside the left end of the torsion beam 10 . The outer mounting portion 40 typically has a notch portion which is notched so as to have a shape along the outer contour shape of the left trailing arm 20 , and the notch portion passes through the arc so as to abut on the outer peripheral surface of the left trailing arm 20 . Welding etc. on it.

The left reinforcement 30 also includes an inner mounting portion 50 as a right end portion inside the torsion beam 10 . The inner mounting portion 50 has a right end portion of the bottom wall portion 31 formed in a shape along the shape of the inner wall surface of the upper wall portion 13 of the torsion beam 10, and a right end portion of the front flange 32 formed in a shape along the torsion beam The shape of the shape of the inner wall surface of the front vertical wall portion 11 of the torsion beam 10 ;

Here, in the right end portion of the bottom wall portion 31 of the inner mounting portion 50, a welding portion W is set corresponding to the seat portion 14 provided on the upper wall portion 13 of the torsion beam 10, and at the welding portion W, the bottom wall is The right end portion of the portion 31 abuts on the seat portion 14 and is welded. The seat portion 14 is a portion of the upper wall portion 13 that protrudes in a protruding direction (upward direction) away from the inner region I of the torsion beam 10 , so that when the torsion beam 10 and the left trailing arm 20 are connected by the left reinforcement 30 Therefore, the rigidity of the upper wall portion 13 including the seat portion 14 can be increased, and the force to be applied to the welding portion W that is the joint portion of the torsion beam 10 and the left reinforcement member 30 can be dispersed, thereby ensuring that the torsion beam 10 and the left reinforcement 30 are connected. The joint strength of the left trailing arm 20 and the flexural rigidity of the torsion beam 10 suppress stress concentration in the welded portion W of the torsion beam 10 and the left stiffener 30 , thereby setting the torsional characteristics of the torsion beam 10 with a high degree of freedom. In addition, from the viewpoint of dispersing the force to be applied to the welded portion W more, it is preferable that the front end portion and the rear end portion of the seat portion 14 are directly connected to the front vertical wall portion 11 and the rear vertical wall portion 12 corresponding to the seat portion 14 . It extends to the front vertical wall portion 11 and the rear vertical wall portion 12 .

In addition, from the viewpoint of reliably suppressing the concentration of stress on the welded portion W between the torsion beam 10 and the left reinforcement 30 , the welded portion W is preferably arranged at the right end portion of the bottom wall portion 31 of the inner mounting portion 50 which is perforated and connected to the seat portion 14 . Correspondingly provided plug welding holes 34 . By providing the plug welding hole 34 in the bottom wall portion 31, it is possible to suppress the concentration of stress on the welded portion W between the torsion beam 10 and the left stiffener 30, and at the same time, the welded portion W can be set on the left stiffener 30 side generally facing downward, and it is possible to The occurrence of accumulation of dust, moisture, etc. on the welded portion W is suppressed. The welded portion W is a plug welded portion obtained by welding at least the peripheral wall portion of the plug welding hole 34 and the lower wall surface of the seat portion 14 by arc welding or the like. If necessary, the entire plug welding hole 34 may be filled with a welding material. In addition, from the viewpoint of more reliably suppressing the concentration of stress on the welded portion W between the torsion beam 10 and the left reinforcement 30, the plug welding hole 34 is preferably an elongated hole connected by a pair of connecting wires 34c, 34d facing each other. A pair of circular arcs 34a, 34b facing each other in a predetermined direction X perpendicular to the upward direction, which is the protruding direction of the seat portion 14, have different diameters. The predetermined direction X is determined from the viewpoint that the stress to be applied to the welded portion W, which is the joint portion of the torsion beam 10 and the left reinforcement member 30 , is balanced between the stress of the welded portion W and the periphery of the plug welding hole 34 . dispersion. In addition, typically, the centers C1, C2 of the pair of arcs 34a, 34b are arranged on a straight line L parallel to the direction X which is when the torsion beam 10 is twisted (particularly in the width direction of the torsion beam 10). When both ends of the torsion beam are twisted in opposite phases) the direction of propagation of the stress generated in the torsion beam is typically the direction crossing the front-rear direction, and the pair of connecting lines 34c and 34d are straight lines or convex toward the outside of the plug welding hole 34 The shape of the plug welding hole 34 is set to be a line-symmetric shape with respect to the straight line L such that the tip portion of the teardrop shape is rounded. In addition, from the viewpoint of achieving stress balance around the plug welding hole 34, the small-diameter arc of the pair of arcs 34a, 34b is preferably closer to the front longitudinally than the large-diameter arc of the pair of arcs 34a, 34b Either one of the wall portion 11 and the rear vertical wall portion 12 is arranged.

Further, the seat portion 14 preferably has a recessed portion 15 that is recessed toward the inner region I so that a part of the seat portion 14 enters the plug welding hole 34 . This allows setting of the through holes 16 functioning as drain holes in the recessed portion 15 , while increasing the rigidity of the seat portion 14 , and reliably suppressing stress concentration on the welded portion W of the torsion beam 10 and the left reinforcement 30 . In addition, from the viewpoint of further improving the rigidity of the seat portion 14 , the recessed portion 15 preferably surrounds the peripheral wall portion of the plug welding hole 34 .

In addition, it is preferable that the inner mounting portion 50 is provided with a flat wall portion 35 which is separated from the upper wall portion 13 at a position offset from the right end portion of the bottom wall portion 31 to the outer mounting portion 40 side and faces the upper wall portion 13 . The wall portion 35 is a portion where the inner mounting portion 50 is recessed toward the upper wall portion 13 , and the right end portion of the inner mounting portion 50 and the flat wall portion 35 are connected by the inclined wall portion 36 . Thereby, the rigidity of the inner mounting portion 50 can be improved, and the stress concentration on the welded portion W of the torsion beam 10 and the left reinforcement 30 can be suppressed reliably.

Moreover, it is preferable that the front side part of the right end part and the rear side part of the right end part of the flat wall part 35 have the front protrusion part 39F and the rear protrusion part 39R which respectively protrude to the right side rather than the intermediate part 39C. Thereby, the welded portion W of the right end portion of the inner mounting portion 50 can be surrounded to further increase the rigidity of the portion, and the force to be applied to the welded portion W of the torsion beam 10 and the left reinforcement 30 can be dispersed.

The left reinforcement 30 further includes an intermediate connecting portion 60 that connects the outer mounting portion 40 and the inner mounting portion 50 . The intermediate connection portion 60 is an inclined portion extending in the width direction while gradually rising from the outer attachment portion 40 toward the inner attachment portion 50 . By adopting such an oblique portion in the intermediate connection portion 60 , it is possible to suppress abrupt shape change in the longitudinal cross-sectional shape of the torsion beam 10 in the width direction, and to alleviate stress concentration in the portion where the shape of the torsion beam 10 changes.

In addition, from the viewpoint of improving the strength and bending rigidity of the torsion beam 10 and improving the joint strength of the torsion beam 10 and the left trailing arm 20, the torsion beam 10 and the left reinforcement member 30 may cooperate to divide the closed cross-section portion S. The closed cross-section portion S that emerges is set so as to extend between the outer mounting portion 40 and the inner mounting portion 50 with the intermediate connection portion 60 interposed therebetween.

In addition, in the left reinforcement 30 , the front flange 32 and the rear flange 33 may be in contact with the inner wall surface of the front vertical wall portion 11 and the inner wall surface of the rear vertical wall portion 12 in the torsion beam 10 corresponding to each other. method, and welding is performed by arc welding or the like corresponding to them.

The left spring seat 80 is typically a plate member made of a metal plate such as a steel plate formed by press forming or the like, and is welded to the torsion beam 10 and the left trailing arm 20 by arc welding or the like, and supports the lower end of the spring.

The shock absorber bracket 90 is typically a plate member formed of a metal plate such as a steel plate formed by press molding or the like, and is welded to the left trailing arm 20 and the left spring seat 80 by arc welding or the like, and supports the lower end of the shock absorber.

In the torsion beam type suspension 1 having the above structure, a vehicle body mounting portion B1 is set as a portion to be mounted on the vehicle body, and a wheel side is set as a mounting portion for mounting various external force applying members. The wheel side mounting portion W1 of the components, the spring mounting portion S1 for mounting the spring, and the damper mounting portion D1 for mounting the shock absorber.

Specifically, the vehicle body attachment portion B1 is arranged corresponding to the collar member 100 provided at the front end portion of the left trailing arm 20 . In this vehicle body mounting portion B1, the front end portion of the left trailing arm 20 is fastened by a bush member (not shown in the figure) that is press-fitted into the collar member 100 by a typical fastening member such as a bolt (not shown in the figure), Thereby, it is attached to the vehicle body.

The wheel-side mounting portion W1 is arranged corresponding to the wheel support member 110 provided at the rear end portion of the left trailing arm 20 . In this wheel-side mounting portion W1, a typical bearing member not shown in the figure is fastened to the wheel support member 110 by a fastening member such as a bolt not shown in the figure, and is attached.

The spring mounting portion S1 is arranged corresponding to the bottom wall portion of the left spring seat 80 . In this spring mounting part S1, the spring not shown in figure is mounted by being mounted on the upper surface part of the bottom wall part of the left spring seat 80. As shown in FIG. In addition, in order to reduce the friction noise of the spring, etc., a disk-shaped elastic member may be placed on the bottom wall portion, and the spring may be placed thereon.

The damper mounting portion D1 is arranged corresponding to the left side wall portion of the damper bracket 90 and the right side wall portion of the left spring seat 80 . In this shock absorber mounting portion D1, the lower end of the shock absorber (not shown in the figure) is fastened by a typical bolt, etc., not shown, through through holes provided in the left side wall portion and the right side wall portion, respectively. is fastened and installed.

In addition, the above-mentioned various wheel support members and nut members are typically made of metal such as steel.

Next, a modification of the torsion beam type suspension 1 in the present embodiment will be described in detail with reference to FIGS. 6 and 7 .

As shown in FIGS. 6 and 7 , in the torsion beam type suspension 1 ′ of the present modification, the main difference from the above-described torsion beam type suspension 1 is that the components for providing the plug welding holes are changed, and the remaining structure is In principle the same. Hereinafter, focusing on this difference, the left reinforcement 30 and its related structure are taken as an example, and the structure of this modification is demonstrated typically.

Specifically, in the torsion beam type suspension 1 ′ in the present modification, the seat portion 14 provided in the upper wall portion 13 of the torsion beam 10 is perforated to provide the plug welding hole 17 , and the inner part of the left reinforcement 30 is drilled. A welding portion W where the right end portion of the bottom wall portion 31 of the mounting portion 50 is in contact with the seat portion 14 and welded is disposed in the plug welding hole 17 . By providing the plug welding hole 17 in the seat portion 14 , the welding portion W can be provided at a portion surrounded by peripheral members generally on the upper side of the vehicle, and it is possible to suppress the occurrence of foreign matter such as debris coming into contact with the welded portion when the vehicle is running. . In addition, this plug welding hole 17 has a structure or the like that exhibits the same shape as the plug welding hole 34 provided in the bottom wall portion 31 of the inner mounting portion 50 .

Further, the inner mounting portion 50 preferably has a recessed setting portion 37 recessed toward the inner region I so that a portion thereof is away from the plug welding hole 17 . This allows the through hole 38 to function as a drain hole to be set in the recessed portion 37 , while increasing the rigidity of the inner mounting portion 50 and improving the reliability of welding between the torsion beam 10 and the reinforcing member. In addition, this recessed installation part 37 has a structure which exhibits the same shape as the recessed installation part 15 provided in the seat part 14, etc., as shown in FIG.

According to the torsion beam type suspensions 1 and 1 ′ of the present embodiment including the above modification examples, the welded portion W is set corresponding to the seat portion 14 provided on the upper wall portion 13 of the torsion beam 10 , and the welded portion W is , the right end portion of the bottom wall portion 31 in the inner mounting portion 50 of the left reinforcement member 30 abuts against the seat portion 14 and is welded. The seat portion 14 is a portion of the upper wall portion 13 that protrudes in a protruding direction (upward direction) away from the inner region I of the torsion beam 10 , so that when the torsion beam 10 and the left trailing arm 20 are connected by the left reinforcement 30 Therefore, the rigidity of the upper wall portion 13 including the seat portion 14 can be increased, and the force to be applied to the welding portion W that is the joint portion of the torsion beam 10 and the left reinforcement member 30 can be dispersed, thereby ensuring that the torsion beam 10 and the left reinforcement 30 are connected. The joint strength of the left trailing arm 20 and the flexural rigidity of the torsion beam 10 suppress stress concentration in the welded portion W of the torsion beam 10 and the left stiffener 30 , thereby setting the torsional characteristics of the torsion beam 10 with a high degree of freedom.

In addition, according to the torsion beam type suspensions 1 and 1 ′ of the present embodiment including the modified examples, the welded portion W is arranged at the right end portion of the bottom wall portion 31 of the inner mounting portion 50 of the left reinforcement member 30 that is perforated to be connected to the seat portion. The plug welding hole 34 provided correspondingly to 14 or the seat portion 14 provided in the upper wall portion 13 of the torsion beam 10 is perforated and arranged in the plug welding hole 17 . When the plug welding hole 34 is provided in the bottom wall portion 31 , in addition to reliably dispersing the force to be applied to the welding portion W, the welding portion W can be set on the left reinforcement 30 side generally facing downward, and it is possible to suppress the Occurs when dust, moisture, etc. stay on the welded portion W. In addition, when the plug welding hole 17 is provided in the seat portion 14 , in addition to reliably dispersing the force to be applied to the welding portion W, the welding portion can also be set at a location surrounded by peripheral members generally on the upper side of the vehicle. W, it is possible to suppress the occurrence of foreign matter such as debris coming into contact with the welded portion when the vehicle is running.

In addition, in the present invention, the type, shape, arrangement, number, etc. of the components are not limited to the above-described embodiments, and of course, the constituent elements can be appropriately replaced with those having equivalent effects without departing from the gist of the invention. make appropriate changes within the range.

As described above, according to the present invention, it is possible to provide a torsion beam type suspension in which, when the torsion beam and the trailing arm are connected by the reinforcing member, the joint strength of the torsion beam and the trailing arm and the strength of the torsion beam can be ensured. The torsional characteristics of the torsion beam can be set with a high degree of freedom by suppressing the concentration of stress on the joint portion of the torsion beam and the reinforcement member with bending rigidity. Therefore, it is expected to be widely used in moving objects such as vehicles due to its general properties. of torsion beam suspension.

Claims (8)

1. A torsion beam suspension comprising: A left trailing arm extending in the longitudinal direction of the vehicle body on the left side in the width direction of the vehicle body, supported by the vehicle body on the front side in the longitudinal direction, and supporting wheels on the rear side in the longitudinal direction ; a right trailing arm that extends along the longitudinal direction on the right side in the width direction, is supported on the vehicle body on the front side in the longitudinal direction, and supports wheels on the rear side in the longitudinal direction; The torsion beam extends along the width direction, and has a pair of wall portions facing each other and a pair of wall portions that is positioned between the pair of wall portions in a longitudinal section cut along a plane perpendicular to the width direction. an open cross-sectional shape of the connected connecting wall portion, and connects the left trailing arm and the right trailing arm; a left reinforcement member extending in the width direction on the left side, and having an inner left attachment portion in the interior surrounded by the pair of wall portions and the connecting wall portion of the torsion beam It is installed on the torsion beam in the area; the outer left installation part is installed on the left trailing arm; and the middle left connection part is connected between the inner left installation part and the outer left installation part, so the left stiffener connects the torsion beam and the left trailing arm; and a right reinforcement extending in the width direction on the right side and having: an inner right mounting portion mounted to the torsion beam in the inner region; an outer right mounting portion mounted to the right a trailing arm; and a middle right connecting portion that connects the inner right mounting portion and the outer right mounting portion, the right reinforcement member connects the torsion beam and the right trailing arm, in, The torsion beam has in the connecting wall part: a left seat part provided with a left welding part where the inner left mounting part is welded to the connecting wall part; and a right seat part, It is provided with a right welding portion where the inner right mounting portion is welded to the connecting wall portion, The left seat portion is a portion of the connecting wall portion that protrudes in a protruding direction away from the inner region, The right seat portion is a portion of the connecting wall portion protruding in the protruding direction. 2. The torsion beam suspension of claim 1, wherein: The left welding portion is arranged at a left plug welding hole provided on one of the connecting wall portion and the inner left mounting portion, The left plug welding hole is a pair of long holes with different diameters of arcs opposite to each other in a direction perpendicular to the protruding direction, The right welding portion is disposed at a right plug welding hole provided on one of the connecting wall portion and the inner right mounting portion, The right plug welding hole is a pair of long holes with different diameters of circular arcs opposed to each other in a direction perpendicular to the protruding direction. 3. The torsion beam suspension of claim 2, wherein: the left plug welding hole is arranged on the inner left mounting part, The right plug welding hole is arranged in the inner right mounting portion. 4. The torsion beam suspension of claim 3, wherein: The left seat portion has a portion recessed toward the inner region in such a manner that a portion thereof enters the left plug welding hole, The right seat has a portion recessed toward the inner region in such a manner that a portion thereof enters the right plug welding hole. 5. The torsion beam suspension of claim 2, wherein: the left plug welding hole is arranged on the left seat part, The right plug welding hole is arranged on the right seat portion. 6. The torsion beam suspension of claim 3, wherein: The inner left mounting portion has a portion recessed toward the inner region in such a way that a portion thereof is away from the left plug welding hole, The inner right mounting portion has a portion recessed toward the inner region in such a manner that a portion thereof is away from the right plug welding hole. 7. The torsion beam suspension of claim 1, wherein: In the inner left mounting portion, a left flat wall portion is provided so as to be offset from the right end portion of the inner left mounting portion to the outer left mounting portion side and to be separated from the connecting wall portion, and a left flat wall portion is provided. The flat wall portion is a portion of the inner left mounting portion that is recessed toward the connecting wall portion, and the right end portion of the inner left mounting portion and the left flat wall portion are connected by a left inclined wall portion, In the inner right mounting portion, a right flat wall portion is provided so as to be offset from the left end portion of the inner right mounting portion toward the outer right mounting portion side and opposed to the connecting wall portion separately. The flat wall portion is a portion in which the inner right mounting portion is recessed toward the connecting wall portion, and the left end portion of the inner right mounting portion and the right flat wall portion are connected by a right inclined wall portion. 8. The torsion beam suspension of claim 7, wherein: A portion of the front side of the right end portion of the left flat wall portion and a portion of the rear side of the right end portion have right projecting portions projecting toward the right side, respectively, The portion on the front side of the left end portion of the right flat wall portion and the portion on the rear side of the left end portion have left protruding portions protruding toward the left side, respectively.

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