JP2020164092A - Torsion beam type suspension - Google Patents

Abstract

To provide a torsion beam type suspension capable of setting a torsion characteristic of the torsion beam to a high degree of freedom in a mode in which bond strength between the torsion beam and a trailing arm and flexural rigidity of the torsion beam are secured and stress concentration on a coupling section between the torsion beam and a reinforcing member is suppressed, when the torsion beam is connected to the trailing arm by the reinforcing member.SOLUTION: In each of torsion beam type suspensions 1 and 1', a weld portion W in which a bottom wall section 31 abuts on a seat section 14 and is welded is set corresponding to the seat section 14 provided on an upper wall section 13 of a torsion beam 10. The seat section 14 is a portion where the upper wall section 13 is projectingly provided in a projecting direction (upper direction) away from an internal region I of the torsion beam 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a torsion beam type suspension, and more particularly to a torsion beam type suspension mounted on a vehicle such as a four-wheeled vehicle.

In recent years, torsion beam suspensions, which have a small number of parts, a relatively simple structure, and excellent space efficiency, have been widely adopted for suspension devices for vehicles such as four-wheeled vehicles, mainly for small displacement vehicles. There is.

Since it is required to secure the required strength and rigidity while suppressing unnecessary influence on the productivity of such a torsion beam type suspension, the left and right trailing arms and the torsion beam are used. , A configuration has been proposed in which the torsion beam is connected by an extending reinforcing member.

Under such circumstances, Patent Document 1 describes two vertical supports (trailing arms) 3 arranged in the longitudinal direction of the vehicle and two trailing arms 3 extending in the lateral direction of the vehicle with respect to the automobile axle 1. In the terminal region 10 on the lateral support 2 side of the reinforcing sheet 4, the lateral support 2 for connecting the two trailing arms 3 and the reinforcing sheet 4 for connecting between the two trailing arms 3 and the lateral support 2 are provided. Discloses a configuration in which a punctate bond 11 such as a plug weld for connecting the bottom web 7 of the metal profile 5 of the lateral support 2 and the reinforcing sheet 4 is provided.

European Patent Application Publication No. 2896522

However, according to the study of the present inventor, in the configuration of Patent Document 1, by providing the point-shaped coupling 11, the force acting on the coupling portion is better distributed, and the lateral support in the reinforcing sheet 4 is provided. Although it is intended to reduce the stress generated in the end region 10 on the second side, the point-shaped joint portion 11 is arranged with respect to an ellipse or an elongated hole extending in the longitudinal direction of the vehicle to be a lateral support. Since it is bonded to the flat bottom web 7 in the metal profile 5 of No. 2, there is naturally a limit to the degree of stress reduction, and there is room for improvement in this respect.

Further, according to the study of the present inventor, 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 connecting these with reinforcing members in order to enhance the joint strength between the torsion beam and the trailing arm and the bending rigidity of the torsion beam, especially when trying to adjust the torsional rigidity of the torsion beam by adjusting the configuration of the reinforcing member, The tendency for stress to concentrate on the joint between the torsion beam and the reinforcing member becomes stronger. In other words, since such a situation limits the degree of freedom in design when optimizing the torsional rigidity of the torsion beam to a low level, it is expected to realize a new configuration that increases the degree of freedom in design when optimizing the torsional rigidity of the torsion beam. It is in a situation where it is being done.

The present invention has been made through the above studies. When the torsion beam and the trailing arm are connected by a reinforcing member, the joint strength between the torsion beam and the trailing arm and the bending rigidity of the torsion beam are ensured, and the torsion beam and the trailing arm are reinforced. It is an object of the present invention to provide a torsion beam type suspension in which the torsional characteristics of the torsion beam can be set with a high degree of freedom in a manner in which stress is suppressed from being concentrated on a joint portion with a member.

In order to achieve the above object, the torsion beam type suspension according to the first aspect of the present invention extends in the longitudinal direction of the vehicle body on the left side in the width direction of the vehicle body and is supported by the vehicle body on the front side in the longitudinal direction. A left trailing arm that supports the wheels on the rear side in the longitudinal direction, and a left trailing arm that extends in the longitudinal direction on the right side in the width direction and is supported by the vehicle body on the front side in the longitudinal direction and is rearward in the longitudinal direction. A pair of wall portions facing each other and a pair of wall portions facing each other in a vertical cross section formed by a right trailing arm that supports a wheel on the side and a plane extending in the width direction and orthogonal to the width direction. A torsion beam having an open cross-sectional shape having a contacting wall portion and connecting the left trailing arm and the right trailing arm, and the pair of walls of the torsion beam extending in the width direction on the left side. The inner left mounting portion attached to the torsion beam, the outer left mounting portion attached to the left trailing arm, and the space between the inner left mounting portion and the outer left mounting portion in the internal region surrounded by the portion and the connecting wall portion. A left stiffener that has an intermediate left connecting portion that connects the torsion beam and the left trailing arm, and an inner right attachment that extends in the width direction on the right side and is attached to the torsion beam in the internal region. The torsion beam and the right trailing arm are connected to each other by having a portion, an outer right mounting portion attached to the right trailing arm, and an intermediate right connecting portion connecting the inner right mounting portion and the outer right mounting portion. The torsion beam includes a left seat portion in which the inner left mounting portion is welded to the connecting wall portion and a left seat portion and the inner right mounting portion are arranged in the connecting wall portion. The left seat portion has a right seat portion on which a right welded portion to be welded is arranged on the connecting wall portion, and the left seat portion is a portion in which the connecting wall portion is projected in a protruding direction away from the internal region. The seat portion is a portion where the connecting wall portion is projected in the protruding direction.

Further, in the present invention, in addition to the first aspect, the left welded portion is arranged in a left plug welded hole provided in one of the connecting wall portion and the inner left mounting portion, and the left plug welded hole is provided. , The pair of arcs facing each other in the direction orthogonal to the protruding direction are elongated holes having different diameters, and the right welded portion is a right plug weld provided on one of the connecting wall portion and the inner right mounting portion. The second aspect is that the right plug weld hole arranged in the hole is an elongated hole having different diameters of a pair of arcs facing each other in a direction orthogonal to the protruding direction.

Further, in the present invention, in addition to 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. It is a phase.

Further, in addition to the third aspect, the present invention has a portion of the left seat portion recessed toward the internal region so that a part thereof penetrates into the left plug weld hole. The fourth aspect of the right seat portion is that the right seat portion has a portion recessed toward the internal region so that a part thereof penetrates into the right plug welding hole.

Further, in the present invention, in addition to 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, as a fifth aspect. To do.

Further, in the present invention, in addition to the third aspect, the inner left mounting portion has a portion recessed toward the inner region so that a part thereof is away from the left plug welding hole. The sixth aspect of the inner right mounting portion is that the inner right mounting portion has a portion recessed toward the inner region so as to be partially away from the right plug welding hole.

Further, in the present invention, in addition to any of the first to sixth aspects, the inner left mounting portion is displaced from the right end portion of the inner left mounting portion to the side of the outer left mounting portion. A left flat wall portion, which is a portion in which the inner left mounting portion is recessed toward the connecting wall portion, is provided so as to face the connecting wall portion at a distance from the connecting wall portion, and the right end portion of the inner left mounting portion is provided. And the left flat wall portion is connected by a left inclined wall portion, and the connecting wall is displaced from the left end portion of the inner right mounting portion to the side of the outer right mounting portion to the inner right mounting portion. A right flat wall portion, which is a portion in which the inner right mounting portion is recessed toward the connecting wall portion, is provided so as to face the portion apart from the portion, and the left end portion of the inner right mounting portion and the said The seventh aspect is that the right flat wall portion is connected by the right inclined wall portion.

Further, in the present invention, in addition to the seventh aspect, the left flat wall portion is a right overhanging portion in which the front side portion of the right end portion and the rear side portion of the right end portion project to the right side. The eighth aspect is that the right flat wall portion has a left overhanging portion in which the front side portion of the left end portion and the rear side portion of the left end portion respectively project to the left side. ..

According to the configuration in the first aspect of the present invention, the torsion beam is provided in the left seat portion and the right stiffener where the left welded portion in which the inner left mounting portion of the left stiffener is welded to the connecting wall portion is arranged in the connecting wall portion. The right mounting portion has a right seat portion on which the right welded portion to be welded to the connecting wall portion is arranged, and the left seat portion is a portion where the connecting wall portion is projected in a protruding direction away from the internal region of the torsion beam. , The left seat and the right seat are used when the torsion beam and the trailing arm are connected by a reinforcing member because the right seat is a portion where the connecting wall is projected in the protruding direction away from the internal region of the torsion beam. By increasing the rigidity of the connecting wall including the portion and distributing the force to be applied to the joint portion between the torsion beam and the reinforcing member, the joint strength between the torsion beam and the trailing arm and the bending rigidity of the torsion beam are secured. , The torsional characteristics of the torsion beam can be set with a high degree of freedom in a manner in which stress is suppressed from being concentrated on the joint portion between the torsion beam and the reinforcing member.

Further, according to the configuration in the second aspect of the present invention, the left welded portion is arranged in the left plug welded hole provided in one of the connecting wall portion and the inner left mounting portion, and the left plug welded hole is in the protruding direction. It is an elongated hole having different diameters of a pair of arcs facing each other in the direction orthogonal to the right plug, and the right welded portion is arranged in the right plug welded hole provided on one of the connecting wall portion and the inner right mounting portion. Since the weld holes are elongated holes having different diameters of a pair of arcs facing each other in the direction orthogonal to the protruding direction, stress is surely suppressed from being concentrated on the joint portion between the torsion beam and the reinforcing member, while being suppressed. The torsional characteristics of the torsion beam can be set with a high degree of freedom.

Further, according to the configuration in 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, so that the vehicle is generally provided. Welds can be set on the left and right stiffeners facing downwards, ensuring that stress is not concentrated on the joint between the torsion beam and the reinforcing member, while dust and moisture are removed from the weld. It is possible to suppress the occurrence of a situation in which the top accumulates.

Further, according to the configuration in the fourth aspect of the present invention, the left seat portion has a portion recessed toward the internal region so that a part thereof penetrates into the left plug weld hole, and the right seat portion has a portion. However, by having a recessed portion toward the internal region so that a part thereof penetrates into the right plug welding hole, a through hole that can function as a drain hole is set in the recessed portion. The rigidity of the left seat portion and the right seat portion can be increased, and the concentration of stress on the joint portion between the torsion beam and the reinforcing member can be surely suppressed.

Further, according to the configuration in 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, so that the vehicle is generally relative to the vehicle. Welded parts can be set on the upper side of the part covered with peripheral parts, and while surely suppressing the concentration of stress on the joint part between the torsion beam and the reinforcing member, chipping during vehicle running, etc. It is possible to suppress the occurrence of a situation in which foreign matter comes into contact with the welded portion.

Further, according to the configuration in the sixth aspect of the present invention, the inner left mounting portion has a portion recessed toward the inner region so that a part thereof is away from the left plug welding hole, and the inner right mounting portion is mounted. Setting through holes that can function as drainage holes in those recessed parts by having the portions recessed towards the internal region so that some of them are away from the right plug weld holes. While allowing the above, the rigidity of the inner left mounting portion and the inner right mounting portion can be increased, and the concentration of stress on the joint portion between the torsion beam and the reinforcing member can be reliably suppressed.

Further, according to the configuration in the seventh aspect of the present invention, the inner left mounting portion faces the connecting wall portion while being displaced from the right end portion of the inner left mounting portion toward the outer left mounting portion. As described above, the left flat wall portion, which is the portion where the inner left mounting portion is recessed toward the connecting wall portion, is provided, and the left inclined wall portion is provided between the right end portion and the left flat wall portion of the inner left mounting portion. The inner right mounting part is connected to the inner right mounting part so that the inner right mounting part faces the connecting wall part while being displaced from the left end part of the inner right mounting part toward the outer right mounting part. A right flat wall portion, which is a portion recessed toward the surface, is provided, and an inner left mounting portion is connected between the left end portion and the right flat wall portion of the inner right mounting portion by a right inclined wall portion. In addition, the rigidity of the inner right mounting portion can be increased to reliably suppress the concentration of stress on the joint portion between the torsion beam and the reinforcing member.

Further, according to the configuration in the eighth aspect of the present invention, the left flat wall portion has a right overhanging portion in which the front side portion of the right end portion and the rear side portion of the right end portion project to the right side, respectively. The right flat wall portion has a left overhanging portion in which the front portion of the left end portion and the rear portion of the left end portion project to the left side, respectively, so that the right end portion of the inner left mounting portion and the left end of the inner right mounting portion are provided. These rigidity can be increased by surrounding the joint portion in the portion, and the concentration of stress on the joint portion between the torsion beam and the reinforcing member can be more reliably suppressed.

It is a partial top view of the torsion beam type suspension in embodiment of this invention. It is a partial rear view of the torsion beam type suspension in this embodiment. FIG. 3A is a partial bottom view of the torsion beam suspension according to the present embodiment, and FIG. 3B is an enlarged view of a plug weld hole in FIG. 3A. FIG. 1 is a sectional view taken along the line AA of FIG. It is BB sectional view of FIG. It is sectional drawing of the torsion beam type suspension of the modification of this embodiment, and it corresponds to FIG. 4 in position. It is sectional drawing of the torsion beam type suspension of the modification of this embodiment, and it corresponds to FIG. 5 in position.

Hereinafter, the torsion beam type suspension according to the embodiment of the present invention including the modification will be described in detail with reference to FIGS. 1 to 7 as appropriate. In the figure, the x-axis, y-axis, and z-axis form a three-axis Cartesian coordinate system. Further, the positive direction of the x-axis is the front 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. Further, the x-axis direction may be referred to as a longitudinal direction or a front-rear direction, the y-axis direction may be referred to as a width direction or a left-right direction, and the z-axis direction may be referred to as a vertical direction.

FIG. 1 is a partial top view of the torsion beam suspension according to the present embodiment, FIG. 2 is a partial rear view of the torsion beam suspension according to the present embodiment, and FIG. 3A is a partial rear view of the torsion beam suspension according to the present embodiment. 3 (b) is an enlarged view of the plug weld hole in FIG. 3 (a). Further, FIG. 4 is a cross-sectional view taken along the line AA of FIG. 1 (a plane parallel to the yz plane: a vertical cross-sectional view cut by a plane orthogonal to the longitudinal direction), and FIG. 4 is a cross-sectional view taken along the line BB of FIG. It is a cross-sectional view (a plane parallel to an xz plane: a vertical cross-sectional view cut by a plane orthogonal to the width direction). Further, FIG. 6 is a cross-sectional view of the torsion beam suspension of the modified example of the present embodiment and corresponds to FIG. 4 in terms of position, and FIG. 7 is a cross-sectional view of the torsion beam suspension of the modified example of the present embodiment. Yes, it corresponds to FIG. 5 in terms of position. Although FIGS. 1 to 7 mainly show the components on the left side of the torsion beam suspension, the components on the right side of the torsion beam suspension have a symmetrical configuration with respect to the configuration on the left side. Further, in the figure, for convenience of explanation, the components on the right side of the torsion beam suspension are indicated by reference numerals in parentheses.

First, the configuration 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 supports a suspension spring (hereinafter referred to as a spring), a suspension damper (hereinafter referred to as a damper), wheels, and the like while being mounted on a vehicle body such as a rear side frame of an automobile or the like (not shown).

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 stiffeners 30, 130. Further, the torsion beam type suspension 1 may include a pair of left and right spring seats 80 and 180 and a pair of left and right damper brackets 90 and 190.

The torsion beam 10 is typically a plate member made of a metal plate such as a steel plate having an upwardly convex shape by press forming or the like, and is welded to each other by arc welding or the like while extending in the width direction. As a result, a pair of left and right trailing arms 20, 120 are connected to both ends thereof.

Specifically, the torsion beam 10 has a front vertical wall portion 11 and a rear vertical wall portion 12 facing each other in the front-rear direction, and a front vertical wall portion 11 and a rear vertical wall portion 12 in a vertical cross section cut by a plane orthogonal to the width direction. The upper wall portion 13 is provided with a seat portion 14 projecting upward while connecting the upper end portions of each in the front-rear direction, and is surrounded by the front vertical wall portion 11, the rear vertical wall portion 12, and the upper wall portion 13. It exhibits an open cross-sectional shape that opens downward while defining the internal region I. Typically, the front vertical wall portion 11 hangs down slightly forward from the upper wall portion 13, and the rear vertical wall portion 12 hangs down slightly backward 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, the upper wall portion 13 may be considered to be substantially in a horizontal position. If necessary, the torsion beam 10 may have an open cross-sectional shape that opens diagonally forward and diagonally downward and backward and diagonally downward. Further, the lower end portion of the front vertical wall portion 11 and the lower end portion of the rear vertical wall portion 12 typically go to the left from the central portion in the width direction in relation to the required torsional characteristics of the torsion beam 10, respectively. Therefore, it is set to gradually lower downward.

Here, the torsion beam type suspension 1 is typically a plane orthogonal to the width direction and basically has a symmetrical shape with respect to the central plane passing through the center in the width direction. The torsion beam 10 has a shape symmetrical to each other with respect to the central plane, and the seat portion 14 is also provided on the upper wall portion 13 as a pair symmetrical to each other. In addition, the left trailing arm 20, the right trailing arm 120, the left stiffener 30, the right stiffener 130, the left spring seat 80 and the right spring seat 180, and the left damper bracket 90 and the right damper bracket 190 are respectively such a central plane. On the other hand, they have symmetrical shapes and are arranged at symmetrical positions. Hereinafter, for convenience of explanation, the left trailing arm 20, left with respect to the pair of left and right trailing arms 20, 120, the pair of left and right stiffeners 30, 130, the pair of left and right spring seats 80, 180, and the pair of left and right damper brackets 90, 190. The stiffener 30, the left spring seat 80, and the left damper bracket 90 will be described as examples.

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 a rolled metal plate such as a steel plate, is welded to the front end portion thereof by arc welding or the like, while the rear end portion thereof. A metal wheel support member 110, typically made of steel or the like, for supporting the wheels is inserted into the portion, and is welded by arc welding or the like. If necessary, the left trailing arm 20 prepares two constituent parts obtained by molding a flat plate member made of a metal plate such as a steel plate into a substantially U-shaped vertical cross section, and these are formed in the width direction or the vertical direction. It may be welded and integrated by arc welding or the like so as to face each other, or it may be composed of a single metal pipe member such as a steel pipe. Further, the wheel support member 110 may be welded by arc welding or the like in a manner in which the wheel support member 110 is simply abutted against the rear end portion of the left trailing arm 20.

The left stiffener 30 is typically a plate member made of a metal plate such as a steel plate formed by press forming or the like, and is arranged extending in the width direction between the torsion beam 10 and the left trailing arm 20. At the same time, the left end and the right end are welded corresponding to the torsion beam 10 and the left trailing arm 20, respectively, to connect them.

Specifically, the left stiffener 30 is a bottom wall portion 31 which is a main body portion of a molded product, a front flange 32 erected above the front end portion of the bottom wall portion 31, and an upward portion from the rear end portion of the bottom wall portion 31. The rear flange 33 is provided upright, and the front flange 32 and the rear flange 33 each extend in the width direction.

The left stiffener 30 includes an outer mounting portion 40 which is a left end portion outside the left end of the torsion beam 10. The outer mounting portion 40 typically has a notch that is cut out so as to follow the outer contour shape of the left trailing arm 20, and the notch is the outer circumference of the left trailing arm 20. It is welded to this by arc welding or the like in a manner of contacting the surface.

The left stiffener 30 further includes an inner mounting portion 50 which is a right end portion inside the torsion beam 10. The inner mounting portion 50 has the shape of the right end of the bottom wall portion 31 formed so as to follow the shape of the inner wall surface of the upper wall portion 13 of the torsion beam 10 and the shape of the inner wall surface of the front vertical wall portion 11 of the torsion beam 10. It has a right end portion of the front flange 32 formed so as to have a shape along the shape, and a right end portion of the rear flange 33 formed so as to have a shape conforming to the shape of the inner wall surface of the rear vertical wall portion 12 of the torsion beam 10.

Here, at the right end portion of the bottom wall portion 31 in the inner mounting portion 50, the right end portion of the bottom wall portion 31 abuts on the seat portion 14 corresponding to the seat portion 14 provided on the upper wall portion 13 of the torsion beam 10. The welded portion W to be welded is set. Since the seat portion 14 is a portion where the upper wall portion 13 projects in the projecting direction (upward direction) away from the internal region I of the torsion beam 10, the torsion beam 10 and the left trailing arm 20 are separated by the left stiffener 30. The torsion beam is formed by increasing the rigidity of the upper wall portion 13 including the seat portion 14 and dispersing the force to be applied to the welded portion W which is the connecting portion between the torsion beam 10 and the left stiffener 30. The torsional characteristics of the torsion beam 10 are adjusted in such a manner that the joint strength between the 10 and the left trailing arm 20 and the bending rigidity of the torsion beam 10 are ensured, and stress is suppressed from being concentrated on the welded portion W between the torsion beam 10 and the left stiffener 30. It can be set with a high degree of freedom. Further, from the viewpoint of more dispersing the force to be applied to the welded portion W, 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. It is preferable that the seat portion 14 extends over the front vertical wall portion 11 and the rear vertical wall portion 12.

Further, from the viewpoint of surely suppressing the concentration of stress on the welded portion W between the torsion beam 10 and the left stiffener 30, the welded portion W is seated by perforating the right end portion of the bottom wall portion 31 of the inner mounting portion 50. It is preferably arranged in the plug welding hole 34 provided so as to correspond to the portion 14. By providing the plug welding hole 34 in the bottom wall portion 31, stress is suppressed from being concentrated on the welded portion W between the torsion beam 10 and the left stiffener 30, and generally, the side of the left stiffener 30 facing downward is suppressed. The welded portion W can be set to, and it is possible to suppress the occurrence of a situation in which dust, moisture, etc. are accumulated on the welded portion W. Such a welded portion W is a plug welded portion in which at least the peripheral wall portion of the plug welded hole 34 and the lower wall surface portion of the seat portion 14 are welded by arc welding or the like, and if necessary, the entire plug welded hole 34 is made of a welding material. It may be filled with. Further, from the viewpoint of more reliably suppressing the concentration of stress on the welded portion W between the torsion beam 10 and the left stiffener 30, the plug weld hole 34 is a predetermined position orthogonal to the upward direction, which is the protruding direction of the seat portion 14. It is preferable that the pair of arcs 34a and 34b facing each other in the direction X are connected by a pair of connecting lines 34c and 34d facing each other, and the pair of arcs 34a and 34b have different diameters. The predetermined direction X is from the viewpoint of balancing the stress around the welded portion W and the plug weld hole 34 and dispersing the force to be applied to the welded portion W which is the joint portion between the torsion beam 10 and the left stiffener 30. It will be decided. Further, typically, the centers C1 and C2 of the pair of arcs 34a and 34b become a torsion beam when the torsion beam 10 is twisted (particularly when both ends in the width direction of the torsion beam 10 are twisted in opposite phases). It is arranged on one straight line L parallel to the direction X, which is the direction in which the generated stress propagates and typically intersects the front-back direction, and the pair of connecting lines 34c and 34d are straight lines or plug welds. The curve is convex toward the outside of the hole 34, and the shape of the plug weld hole 34 is set to be line-symmetric with respect to a straight line L such that the tip of a so-called drop shape is rounded. .. Further, from the viewpoint of balancing the stress around the plug weld hole 34, the one having a small diameter among the pair of arcs 34a and 34b has a front vertical wall portion more than the one having a large diameter among the pair of arcs 34a and 34b. It is preferable that the 11 and the rear vertical wall portion 12 are arranged close to each other.

Further, it is preferable that the seat portion 14 has a recessed portion 15 that is recessed toward the internal region I so that a part thereof penetrates into the plug welding hole 34. As a result, while allowing the recessed portion 15 to have a through hole 16 that can function as a drainage hole, the rigidity of the seat portion 14 is increased, and stress is concentrated on the welded portion W between the torsion beam 10 and the left stiffener 30. It can be surely suppressed. Further, from the viewpoint of further increasing the rigidity of the seat portion 14, it is preferable that the recessed portion 15 orbits along the peripheral wall portion of the plug weld hole 34.

Further, on the inner mounting portion 50, the inner mounting portion 50 is opposed to the upper wall portion 13 at a portion displaced from the right end portion of the bottom wall portion 31 toward the outer mounting portion 40. It is preferable that the flat wall portion 35, which is a portion recessed toward 13, is provided, and that the right end portion of the inner mounting portion 50 and the flat wall portion 35 are connected by an inclined wall portion 36. As a result, it is possible to reliably suppress the concentration of stress on the welded portion W between the torsion beam 10 and the left stiffener 30 while increasing the rigidity of the inner mounting portion 50.

Further, it is preferable that the flat wall portion 35 has a front overhanging portion 39F and a rear overhanging portion 39R in which the front side portion of the right end portion and the rear side portion of the right end portion project to the right side of the intermediate portion 39C, respectively. As a result, it is possible to surround the welded portion W at the right end of the inner mounting portion 50 to further increase the rigidity of that portion and to disperse the force to be applied to the welded portion W between the torsion beam 10 and the left stiffener 30.

The left stiffener 30 further includes an intermediate connecting portion 60 that connects the outer mounting portion 40 and the inner mounting portion 50. The intermediate connecting portion 60 is an oblique portion extending in the width direction while gradually rising from the outer mounting portion 40 toward the inner mounting portion 50. When the intermediate connecting portion 60 takes such an aspect of the oblique portion, a sudden change in the vertical cross-sectional shape in the width direction of the torsion beam 10 can be suppressed, and stress concentration in the portion where the shape of the torsion beam 10 has changed can be suppressed. It can be relaxed.

Further, from the viewpoint of improving the strength and bending rigidity of the torsion beam 10 and improving the joint strength between the torsion beam 10 and the left trailing arm 20, the torsion beam 10 and the left stiffener 30 cooperate to form the closed cross-section portion S. The closed cross-section portion S defined may be set so as to extend between the outer mounting portion 40 and the inner mounting portion 50 with the intermediate connecting portion 60 in between.

Further, in the left stiffener 30, the front flange 32 and the rear flange 33 correspond to 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 corresponding torsion beams 10, respectively. It may be welded by arc welding or the like.

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 a spring. It supports the lower end of the.

The damper bracket 90 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 left trailing arm 20 and the left spring seat 80 by arc welding or the like. It supports the lower end of the damper.

In the torsion beam type suspension 1 having the above configuration, the vehicle body mounting portion B1 is set as a portion to be mounted on the vehicle body, and the wheel side mounting is provided as a mounting portion for mounting various external force applying parts. A portion W1, a spring mounting portion S1 for mounting a spring, and a damper mounting portion D1 for mounting a damper are set.

Specifically, the vehicle body mounting portion B1 is arranged corresponding to the collar member 100 provided at the front end portion of the left trailing arm 20. In the vehicle body mounting portion B1, the front end portion of the left trailing arm 20 is fastened to the collar member 100 via a bush member (not shown) that is press-fitted into the collar member 100, and is typically fastened with a fastening member such as a bolt (not shown). By being 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 such a wheel side mounting portion W1, a bearing member (not shown) is typically mounted by being fastened to the wheel support member 110 with a fastening member such as a bolt (not shown).

The spring mounting portion S1 is arranged so as to correspond to the bottom wall portion of the left spring seat 80. In such a spring mounting portion S1, a spring (not shown) is mounted by being mounted on the upper surface portion of the bottom wall portion of the left spring seat 80. In addition, in order to reduce the rubbing noise of the spring, a disk-shaped elastic member may be placed on the bottom wall portion, and the spring may be placed on the disk-shaped elastic member.

The damper mounting portion D1 is arranged so as to correspond to the left wall portion of the damper bracket 90 and the right wall portion of the left spring seat 80. In the damper mounting portion D1, the lower end portion of the damper (not shown) is typically fastened with a bolt or the like (not shown) through through holes provided in each of the left side wall portion and the right side wall portion. It is attached by being fastened with a member.

The various wheel support members and nut members described above are typically made of metal such as steel.

Next, a modified example 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, the main difference between the torsion beam type suspension 1'in this modified example is that the member provided with the plug weld hole is changed from the above-mentioned torsion beam type suspension 1. Yes, the composition of the remainder is the same in principle. Hereinafter, while paying attention to such a difference, the configuration of the present modification will be typically described by taking the left stiffener 30 and its related configuration as an example.

Specifically, in the torsion beam type suspension 1'in this modified example, the seat portion 14 provided in the upper wall portion 13 of the torsion beam 10 is perforated to provide a plug welding hole 17, and the inner mounting portion 50 in the left stiffener 30 is provided. The welded portion W in which the right end portion of the bottom wall portion 31 of the bottom wall portion 31 abuts on the seat portion 14 and is welded is arranged in the plug welding hole 17. By providing the plug welding hole 17 in the seat portion 14, it is possible to set the welded portion W in a portion surrounded by peripheral parts on the upper side of the vehicle in general, and foreign matter such as chipping during vehicle traveling can be set. It is possible to suppress the occurrence of a situation where the welded portion comes into contact with the welded portion. Further, the plug welding hole 17 has a structure having a shape similar to that of the plug welding hole 34 provided in the bottom wall portion 31 of the inner mounting portion 50.

Further, it is preferable that the inner mounting portion 50 has a recessed portion 37 that is recessed toward the internal region I so that a part thereof is away from the plug welding hole 17. As a result, while allowing the recessed portion 37 to have a through hole 38 that can function as a drainage hole, the rigidity of the inner mounting portion 50 is increased to improve the reliability of welding between the torsion beam 10 and the reinforcing member. can do. Further, the recessed portion 37 has a configuration having the same shape as that of the recessed portion 15 provided in the seat portion 14.

According to the torsion beam type suspensions 1 and 1'of the present embodiment including the above modification, the bottom of the left stiffener 30 in the inner mounting portion 50 corresponding to the seat portion 14 provided on the upper wall portion 13 of the torsion beam 10. A welded portion W is set in which the right end portion of the wall portion 31 abuts on the seat portion 14 and is welded. Since the seat portion 14 is a portion where the upper wall portion 13 projects in the protruding direction (upward direction) away from the internal region I of the torsion beam 10, the torsion beam 10 and the left trailing arm 20 are connected by the left stiffener 30. In this case, the rigidity of the upper wall portion 13 including the seat portion 14 is increased, and the force to be applied to the welded portion W, which is the joint portion between the torsion beam 10 and the left stiffener 30, is dispersed to the torsion beam 10. The torsional characteristics of the torsion beam 10 are flexible in a manner in which the joint strength with the left trailing arm 20 and the bending rigidity of the torsion beam 10 are ensured and stress is suppressed from being concentrated on the welded portion W between the torsion beam 10 and the left stiffener 30. Can be set high.

Further, according to the torsion beam type suspensions 1 and 1'of the present embodiment including the modification, the welded portion W is formed into the seat portion 14 by perforating the right end portion of the bottom wall portion 31 in the inner mounting portion 50 of the left stiffener 30. A corresponding plug welding hole 34 or a 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 weld hole 34 is provided in the bottom wall portion 31, in addition to reliably dispersing the force to be applied to the welded portion W, it is generally welded to the side of the left stiffener 30 facing downward. The portion W can be set, and it is possible to suppress the occurrence of a situation in which dust, moisture, etc. are accumulated on the welded portion W. Further, 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 welded portion W, it is generally surrounded by peripheral parts on the upper side of the vehicle. The welded portion W can be set at the portion to be welded, and it is possible to suppress the occurrence of a situation in which a foreign matter such as chipping when the vehicle is running comes into contact with the welded portion.

It should be noted that the present invention is not limited to the above-described embodiment in terms of the type, shape, arrangement, number, etc. of the members, and the gist of the invention is described by appropriately replacing the constituent elements with those having the same effect and effect. Of course, it can be changed as appropriate without deviation.

As described above, in the present invention, when the torsion beam and the trailing arm are connected by the reinforcing member, the joint strength between the torsion beam and the trailing arm and the bending rigidity of the torsion beam are ensured, and the torsion beam and the reinforcing member are connected. Since it is possible to provide a torsion beam type suspension in which the torsional characteristics of the torsion beam can be set with a high degree of freedom in a manner in which stress is suppressed from being concentrated on a portion, the vehicle is widely used due to its general-purpose universal character. It is expected that it can be applied to the field of torsion beam type suspension of moving objects such as.

1, 1'... Torsion beam type suspension 10 ... Torsion beam 11 ... Front vertical wall part 12 ... Rear vertical wall part 13 ... Upper wall part 14 ... Seat part 15 ... Indentation part 16 ... Through hole 17 ... Plug welding holes 20, 120 ... Trailing arms 30, 130 ... Stiffener 31 ... Bottom wall 32 ... Front flange 33 ... Rear flange 34 ... Plug welding holes 34a, 34b ... Arc 34c, 34d ... Connection line 35 ... Flat wall 36 ... Inclined portion 37 ... Indentation Part 38 ... Through hole 39C ... Intermediate part 39F ... Front overhanging part 39R ... Rear overhanging part 40 ... Outer mounting part 50 ... Inner mounting part 60 ... Intermediate connecting part 80, 180 ... Spring seat 90, 190 ... Damper bracket 100 ... Color member 110 ... Wheel support member W ... Welded part I ... Internal area S ... Closed cross section B1 ... Body mounting part D1 ... Damper mounting part W1 ... Wheel side mounting part S1 ... Spring mounting part

Claims (8)

A left trailing arm that extends in the longitudinal direction of the vehicle body on the left side in the width direction of the vehicle body, is supported by the vehicle body on the front side in the longitudinal direction, and supports wheels on the rear side in the longitudinal direction.
A right trailing arm that extends in the longitudinal direction on the right side in the width direction, is supported by the vehicle body on the front side in the longitudinal direction, and supports wheels on the rear side in the longitudinal direction.
In a vertical cross section extending in the width direction and cut by a plane orthogonal to the width direction, it exhibits 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. With the torsion beam connecting the left trailing arm and the right trailing arm,
It extends in the width direction on the left side, and is attached to the inner left mounting portion and the left trailing arm attached to the torsion beam in the internal region surrounded by the pair of wall portions and the connecting wall portion of the torsion beam. A left stiffener having an outer left mounting portion and an intermediate left connecting portion connecting the inner left mounting portion and the outer left mounting portion to connect the torsion beam and the left trailing arm.
The inner right mounting portion that extends in the width direction on the right side and is mounted on the torsion beam in the internal region, the outer right mounting portion that is mounted on the right trailing arm, and the inner right mounting portion and the outer right mounting portion. A right stiffener that has an intermediate right connecting part that connects the parts and connects the torsion beam and the right trailing arm.
With
The torsion beam is such that in the connecting wall portion, the left seat portion where the left welding portion where the inner left mounting portion is welded to the connecting wall portion is arranged and the right side where the inner right mounting portion is welded to the connecting wall portion. It has a right seat on which the weld is placed
The left seat portion is a portion where the connecting wall portion is projected in a protruding direction away from the internal region.
The right seat portion is a torsion beam type suspension in which the connecting wall portion is projected in the protruding direction. The left welded portion is arranged in a left plug welded hole provided in one of the connecting wall portion and the inner left mounting portion.
The left plug weld hole is an elongated hole having different diameters of a pair of arcs facing each other in a direction orthogonal to the protruding direction.
The right welded portion is arranged in a right plug welded hole provided in one of the connecting wall portion and the inner right mounting portion.
The torsion beam suspension according to claim 1, wherein the right plug weld hole is an elongated hole having different diameters of a pair of arcs facing each other in a direction orthogonal to the protruding direction. The left plug welding hole is provided in the inner left mounting portion.
The torsion beam type suspension according to claim 2, wherein the right plug welding hole is provided in the inner right mounting portion. The left seat portion has a portion recessed toward the internal region so that a part thereof penetrates into the left plug weld hole.
The torsion beam suspension according to claim 3, wherein the right seat portion has a portion recessed toward the internal region so that a part thereof penetrates into the right plug welding hole. The left plug welding hole is provided in the left seat portion.
The torsion beam type suspension according to claim 2, wherein the right plug welding hole is provided in the right seat portion. The inner left mounting portion has a portion recessed toward the inner region so that a part thereof is away from the left plug welding hole.
The torsion beam suspension according to claim 3, wherein the inner right mounting portion has a portion recessed toward the inner region so that a part thereof is away from the right plug welding hole. The inner left mounting portion communicates with the inner left mounting portion so that the inner left mounting portion faces the connecting wall portion while being displaced from the right end portion of the inner left mounting portion toward the outer left mounting portion. A left flat wall portion, which is a portion recessed toward the wall portion, is provided, and the right end portion and the left flat wall portion of the inner left mounting portion are connected by a left inclined wall portion.
The inner right mounting portion communicates with the inner right mounting portion so that the inner right mounting portion faces the connecting wall portion while being displaced from the left end portion of the inner right mounting portion toward the outer right mounting portion. A claim in which a right flat wall portion, which is a portion recessed toward the wall portion, is provided, and a right inclined wall portion communicates between the left end portion and the right flat wall portion of the inner right mounting portion. The torsion beam type suspension according to any one of 1 to 6. The left flat wall portion has a right overhanging portion in which the front side portion of the right end portion and the rear side portion of the right end portion project to the right side.
The torsion beam suspension according to claim 7, wherein the right flat wall portion has a left end portion having a front portion thereof and a rear portion of the left end portion projecting to the left side.

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