JP2000272536A - Body member for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently enhance collision performance and rigidity performance compared with a conventional body member, and reduce vehicle weight and a cost. SOLUTION: In this body member, a rear side member 21 of a body member has a part of a U-shaped cross-section and flange parts formed in both end parts of the U-shaped part to be directed outwards and is formed into a basic cross-section of a substantially hat shape, the rear side member 21 is constituted of both side parts 21a, 21b connected to a rear side extension member 41 and the like, and of a main body part 21c located in the central part surrounded with the both side parts 21a, 21b. A plate thickness of the main body part 21c is formed thicker than those of the both side parts 21a, 21b, and both end parts of the main body 21c are welded by continuous welding while fellow one-end parts of the both side parts 21a, 21b are butted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body member member constituting a vehicle body member such as a rear side member or a rear side extension member of a vehicle.

[0002]

2. Description of the Related Art As shown in FIGS. 4 and 5, a body member member of an automobile is, for example, a rear side member 1 and has a U-shaped cross-section 2 and outwards at necessary positions at both ends of the U-shape. , And has a substantially hat-shaped basic cross-section, and is connected to other body member members, for example, the rear side extension member 6.
The main body 1c at the center between the mounting portion of the rear suspension bracket 4 and the mounting portion of the rear suspension mounting 5 is formed by integral molding between the mounting portion of the rear suspension bracket 4 and the mounting portion of the rear suspension mounting 5. The outer peripheral portion of the reinforcing member 7 and the main body 1c are welded to each other by intermittent welding by spot welding with the letter-shaped reinforcing member 7 attached.

As another example, there is a rear side extension member 6 shown in FIG.
A U-shaped reinforcing member 12 is attached to the inside thereof, and is welded to the rear extension member 6 by intermittent welding by spot welding, and a mounting point at which the rear suspension bracket 14 is mounted with the mounting piece 13 interposed therebetween. Have strengthened.

[0004]

However, the rear side member 1 shown in FIGS. 4 and 5 will be described as a representative example. A reinforcing member 7 is added to the main body 1c, and the two are intermittently spot-welded. , It is inevitable that the overall weight of the member will increase, and moreover, because of the intermittent welding by the spot welding 10, the inner ridge line (in the circular portion) that the spot welding 10 cannot perform. In (2), the rear side member 1 and the reinforcing member 7 have a two-plate shape, but the collision performance and rigidity performance of the two-plate shape cannot be obtained. That is, the collision performance is determined by the thickness of the ridge line and the absorbed energy of the tensile strength.
Although it is determined by the thickness of the ridge and the size of the U-shaped cross section, the main body 1c and the reinforcing member 7 are connected by spot welding 1
Because of the intermittent welding according to No. 0, a stress with the longitudinal direction of the rear side member 1 as an axis is applied as a concentrated load to the spot welded portion 10, and an additional portion between the main body portion 1 c where the spot weld 10 is not applied and the reinforcing member 7. In this case, only the performance of the thicker one can be exhibited.
No synergistic effect between the thickness of c and the thickness of the reinforcing member 7 can be obtained.

For this reason, measures to increase the number of spots of the spot welding 10 are taken. However, this not only increases the number of working steps but also naturally limits the number of spots of the spot welding, and has a sufficient rigidity. Performance and collision performance cannot be obtained. As a result, measures such as increasing the thickness of the reinforcing member 7 and taking other measures such as adding another reinforcing member to both sides 1a and 1b are taken. And cost increase.

It is also adopted that a box structure is formed between the rear side member 1 and the rear side member 1 by a reinforcing member 11 on the side of the rear suspension bracket 4 or the rear suspension mount bracket 5 for reinforcement. Even if the box structure as described above is used because it does not have sufficient rigidity performance and collision performance, the box structure may be displaced and the desired rigidity may not be obtained.

Further, in the case of the rear side extension member 6 shown in FIG. 6, since the U-shaped reinforcing member 12 is additionally welded by spot welding, it is necessary to obtain desired rigidity and collision performance. As a result, the weight of the vehicle body increases and the cost increases.

Accordingly, an object of the present invention is to provide a vehicle body member member capable of sufficiently improving the collision performance and rigidity performance as compared with the conventional vehicle body member member, and further reducing the vehicle weight and cost. And

[0009]

In order to achieve the above object, a vehicle body member according to the present invention has a U-shaped cross section and outward flanges formed at both ends of the U-shaped part. And a vehicle body member having a substantially hat-shaped basic cross section, wherein the vehicle body member is constituted by at least one pair of divided members, and the thickness of one of the pair of divided members is set to another plate thickness. It is characterized in that it is formed thicker than the plate thickness of the divided members, and the ends of these two divided members are butted together and welded by continuous welding.

[0010] With the above configuration, since the plate thickness of one of the pair of divided members is formed larger than the plate thickness of the other divided member, improvement in rigidity performance and collision performance can be expected. In conjunction with this, since the two divided members are joined by continuous welding without any gap (so-called tailored blank welding), even if a torsional moment about the longitudinal direction of the vehicle body member is applied, it is not affected. The shear force generated by the above can be distributed over the entire joint to eliminate partial stress concentration, and sufficient rigidity performance and collision performance can be obtained without using a conventional reinforcing member, and the vehicle Weight reduction and cost reduction can be achieved.

According to a second aspect of the present invention, there is provided a vehicle body member having a substantially hat-shaped basic cross section having a U-shaped cross section and outward flanges formed at both ends of the U-shaped section. A member, wherein the vehicle body member member is composed of at least a pair of divided members, and one of the pair of divided members is formed of a material having a tensile strength higher than a tensile strength of a material forming the other divided member. The ends of these two divided members are butted and welded by continuous welding.

With the above configuration, the material tensile strength of one of the pair of divided members is set to be higher than the material tensile strength of the other divided member.
The rigidity performance and the collision performance can be expected to be improved, and in conjunction with this, since the two divided members are joined by continuous welding without any gap, a torsional moment about the longitudinal direction of the body member member is applied. As a result, the shear force generated thereby can be distributed over the entire joint to eliminate partial stress concentration, and sufficient rigidity performance and collision performance can be obtained without using a conventional reinforcing member. Thus, the weight and cost of the vehicle can be reduced.

According to a third aspect of the present invention, the vehicle body member is composed of three divided members, and the thickness of one of the three divided members is reduced by the thickness of the other two divided members. It is formed so as to be thicker than the plate thickness, and both ends of the thicker divided member are respectively welded by continuous welding while butting against one ends of the other two divided members.

According to the above configuration, the thickness of one of the three divided members is made larger than the thickness of the other two divided members. It is expected that the performance will be improved, and together with this, both ends of one split member are joined to one ends of the other two split members by continuous welding without gaps, so that the vehicle body member Even if a torsional moment about the longitudinal direction of the member is applied, the resulting shear force is distributed over the entire joint to eliminate partial stress concentration, and without using a conventional reinforcing member, Sufficient rigidity and collision performance can be obtained, and the weight and cost of the vehicle can be reduced.

According to a fourth aspect of the present invention, the vehicle body member comprises a divided member divided into three, and one of the three divided members is replaced with the other two divided members. It is made of a material having a higher tensile strength than the constituent material, and both ends of a divided member made of a material having a high tensile strength are welded by continuous welding by abutting against one ends of the other two divided members. It is assumed that.

According to the above configuration, the material tensile strength of one of the three divided members is set higher than the material tensile strength of the other two divided members. And the collision performance can be expected to be improved. In conjunction with this, both ends of one divided member are joined to one ends of the other two divided members by continuous welding without gaps. Even if a torsional moment about the longitudinal direction of the vehicle body member is applied, the shear force generated by the torsion moment is distributed over the entire joint and partial stress concentration can be eliminated, eliminating the need for a conventional reinforcing member. In both cases, sufficient rigidity performance and collision performance can be obtained, and the weight and cost of the vehicle can be reduced.

According to a fifth aspect of the present invention, the vehicle body member is a rear side member, and the sixth aspect of the present invention is arranged such that the vehicle body member is a rear side extension. It is characterized by being a member.

With the above structure, the rigidity performance and the collision performance of the rear side member or the rear side extension member can be improved, and the reinforcement member can be eliminated, so that the weight and cost of the vehicle can be reduced.

[0019]

Next, a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an exploded perspective view showing a rear side member which is a vehicle body member member showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line II-II of FIG. 1 with a rear suspension bracket attached. .

In the figure, reference numeral 21 denotes a rear side member, and the rear side member 21 has a basic section formed of a U-shaped section 22 and an outwardly directed flange 23 at an appropriate position of the U-shaped section 22. Both sides 21a and 21b are formed in a substantially hat shape and are connected to a body member, for example, a rear side extension member 26.
And a main body 21c located at the center between the two side parts 21a and 21b.

The main body 21c has two side parts 21a,
Compared to 21b, a material having a larger plate thickness and / or a material having a higher tensile strength are used. For example, although it is common to use a high-tensile steel material having a tensile strength of 38 Kg / mm ² , the sheet thickness is a press-formed product using a sheet material of 1.4 mm on both sides 21 a and 21 b. On the other hand, the main body 21c has a length of 1.8 mm or more.
It is a press-formed product using a 2.3 mm plate material. Alternatively, it is common to use a plate having a thickness of 1.4 mm to 2.0 mm, but it is a press-formed product using a high-tensile steel material having a tensile strength of 38 kg / mm ² on both sides 21 a and 21 b. On the other hand, in the main body 21c,
It is a press-formed product using 60 kg / mm ² ultra high tensile steel. Further, it is conceivable to use a body having a high tensile strength and a large plate thickness for the both sides 21a and 21b.

Further, both end portions of the main body portion 21c are connected to both side portions 21c.
The rear side member 21 is formed by abutting against one end of each of the a and 21b and performing continuous welding 33 by a so-called tailored blanking method on the abutting portion by welding.

A rear suspension bracket 24 is mounted on one end of the main body 21c, and a rear suspension mount bracket 25 is mounted on one end of one side 21b. Thus, the rear suspension mount bracket 25 is attached to one of the two side portions 21b.
The cross member 34 is mounted on one of the two side portions 21b, and the desired rigidity performance and collision performance can be obtained by mounting the cross member 34. When the cross member is not mounted on one of the two side parts 21b, the rear suspension mount bracket 25 is mounted on the main body part 21c side.

The rear suspension bracket 24 includes
A reinforcing member 27 is provided, and the reinforcing member 27
A box structure is formed between the main suspension 21c and the main body 21c to provide a reinforcing structure for the rear suspension bracket 24.

In the case of the above construction, the rear side member 21 is set such that the body thickness and / or the tensile strength of the main body portion 21c are higher than those of the both side portions 21a and 21b. And the main body portion 21c are continuously welded by the continuous welding portion 33, so that when a torsional stress is applied around the longitudinal direction of the rear side member 21, the main body portion 21c is first received, and If it cannot be received at 21c, both sides 21a,
21b.

Therefore, the collision performance of the rear side member 21 is determined by the thickness of the ridge portion 22a of the U-shaped section 22 and the absorbed energy of the tensile strength, and the rigidity performance is determined by the ridge portion of the U-shaped section 22. And the size of the U-shaped cross section.

Then, the plate thickness of the main body 21c is
When a material thicker than the plate thickness of 1a, 21b is used, the collision performance can be increased correspondingly, but rather, it is adopted as a case where importance is placed on rigidity performance. When a material having a high stiffness is used, the rigidity performance can be increased correspondingly, but rather, the employment of a material with an emphasis on the collision performance is adopted.

Therefore, both sides 21a, 21b and main body 2
By appropriately selecting the plate thickness and the tensile strength in 1c, the same improvement in the collision performance and the rigidity performance can be achieved.

If the torsion stress cannot be received by the main body portion 21c, the torsion stress propagates to the both side portions 21a and 21b via the continuous welded portion 33.
Since the continuous welding portion 33 welds the main body portion 21a and the main body portion 21c without any gap including the ridge line portion 22a in the circle of FIG. 2, a stress concentration that occurs in the conventional spot welding portion may occur. Instead, the stress is dispersed over the entire circumference of the U-shaped section 22, so that a synergistic effect between the both sides 21a, 21b and the main body 21c is obtained, and both the impact performance and the rigidity performance are further improved. be able to.

For this reason, the conventional reinforcing member 7 can be eliminated, and the side portions 21a and 21b do not need to be so thick.
Naturally, the reinforcing members and the like attached and fixed to the a and 21b are not required, so that the impact performance and the rigidity performance of the entire rear side member 21 can be improved, and the weight and cost of the vehicle body can be reduced. become.

Next, the second embodiment of the present invention will be described with reference to FIG.
An embodiment will be described.

In the second embodiment, the present invention is applied to a rear side extension member.
The rear side extension member 41 has a substantially U-shaped cross section having a U-shaped section 42 and outward flange portions 43 formed at both ends of the U-shaped section 42.

The rear side extension member 41 has a straight shape in the longitudinal direction.
It is composed of two divided members consisting of a main body 41a on which the tie-down hook 49 is mounted with the mounting piece 48 interposed, and a side 41b.

The main body portion 41a and the side portion 41b are butted against each other, and the butt portion is welded and connected by applying a continuous welded portion 53 by a so-called tailored blank system, thereby forming the rear side extension member 41. .

In order to mainly support the stress applied from the tie-down hook 49, the body portion 41a is made of a material having a greater thickness than the side portion 41b, as in the first embodiment. (In the case shown), or ultra high tensile steel having high tensile strength is used. Alternatively, a case of using a high-thickness steel plate having a plate thickness is also conceivable.

With the above structure, the rear side extension member 41 is attached to the main body 41 with respect to the side 41b.
The thickness and / or tensile strength of a are set high.
In addition, the side part 41b and the main body part 41a are
When the torsion stress is applied to the rear side extension member 41 in the longitudinal direction, the main body portion 41a first receives the torsion stress.
If it cannot be received by the main body portion 41a, it propagates to the side portion 41b and is received.

Therefore, the collision performance of the rear side extension member 41 is determined by the thickness of the ridge portion of the U-shaped section 42 and the absorbed energy of the tensile strength.
The rigidity performance is determined by the thickness of the ridge line portion of the U-shaped section 42 and the size of the U-shaped cross section.

The thickness of the main body portion 41a is
When a material thicker than the plate thickness b is used, the collision performance can be increased accordingly, but rather, it is adopted as a case where importance is placed on rigidity performance, and the main body portion 41a has a high tensile strength. When using materials,
Rigidity performance can be increased accordingly, but rather, it has been adopted with emphasis on collision performance.

Therefore, by appropriately selecting the thickness and tensile strength of the side portion 41b and the main body portion 41a,
The same improvement in crash performance and stiffness performance can be achieved.

If the torsion stress cannot be received by the main body portion 41a, the torsion stress propagates to the side portion 41b through the continuous welding portion 53, but the side portion 41b and the main body portion 41a are continuously welded. U-shaped section 42 by section 53
Because it is welded without gaps including the ridge line part, stress concentration that occurs in spot welds as in the past can not occur,
Since the stress is dispersed over the entire circumference of the U-shaped section 42, a synergistic effect between the side section 41b and the main body section 41a is obtained, and both the impact performance and the rigidity performance can be further improved.

For this reason, the conventional reinforcing member 12 can be eliminated, and the rear side extension member 4 can be omitted.
(1) The overall impact performance and rigidity performance can be improved, which leads to weight reduction and cost reduction of the vehicle body.

In the above embodiment, the main body portion 21c and the side portions 21a and 21b of the rear side member 21 are formed into a predetermined shape and then welded by continuous welding. However, the present invention is not limited to this. Instead, it is also conceivable to form the main body 21c and both sides 21a, 21b into a predetermined shape after the main body 21c and both sides 21a, 21b are welded by continuous welding in advance.

[0044]

As described below, the vehicle body member according to the present invention has a substantially hat-shaped basic cross-section having a U-shaped cross section and outward flanges formed at both ends of the U-shaped section. A vehicle body member configured, wherein the vehicle body member member is constituted by at least a pair of divided members, and a plate thickness of one of the pair of divided members is formed to be larger than a plate thickness of another divided member. Then, since the end portions of these two divided members are butted and welded by continuous welding, the thickness of one of the pair of divided members is reduced by the thickness of the other divided member. Since it is formed thicker, rigidity performance and collision performance can be expected to be improved, and in conjunction with this, both divided members are joined by continuous welding without any gap (so-called tailored blank welding). From the car body Even if a torsional moment about the longitudinal direction of the member is applied, the resulting shear force is distributed throughout the joint, eliminating partial stress concentration, and eliminating the need for a conventional reinforcing member. As a result, sufficient rigidity performance and collision performance can be obtained, and the weight and cost of the vehicle can be reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a rear side member as a vehicle body member member of an automobile according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG. 1 with a rear suspension bracket attached.

FIG. 3 is an exploded perspective view showing a rear side extension member as a vehicle body member member according to a second embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a rear side member which is a conventional vehicle body member member.

FIG. 5 is a sectional view taken along line VV of FIG. 4 with the rear suspension bracket attached.

FIG. 6 is an exploded perspective view showing a rear side extension member which is a conventional vehicle body member member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Rear side member 21a, 21b Both sides 21c Main part 22 U-shaped section 23 Flange part 24 Rear suspension bracket 25 Rear suspension mount bracket 33 Continuous welded part 41 Rear side extension member 41a Main part 41b Side part 42 U-shaped section 43 Flange 53 Continuous weld

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Fujio Toyama 19-1 Gomishima, Fuji-shi, Shizuoka Prefecture Inside Unipres Co., Ltd. (72) Inventor Kenichi Watanabe 1 Kanazawacho, Kakogawa-shi, Hyogo Prefecture Kobe Steel Works Kakogawa Corporation Inside the steelworks (72) Inventor Michiharu Nakaya 1 Kanazawa-cho, Kakogawa-shi, Hyogo Kobe Steel, Ltd.Kakogawa Works

Claims (6)

[Claims] 1. A vehicle member having a substantially U-shaped cross section and outwardly formed flanges formed at both ends of the U-shaped section and having a substantially hat-shaped basic cross section. The member is constituted by at least a pair of divided members, and the thickness of one of the divided members is formed to be greater than the thickness of the other divided member, and the ends of these divided members are butted together. A vehicle body member member characterized by being welded by continuous welding. 2. A body member member having a substantially U-shaped cross section and a substantially hat-shaped basic cross section having a U-shaped section and outward flanges formed at both ends of the U-shaped section. The member is composed of at least a pair of divided members, and one of the pair of divided members is formed of a material having a tensile strength higher than the tensile strength of the material forming the other divided member. A body member for an automobile, wherein the members are butted together by continuous welding. 3. The vehicle body member member is composed of three divided members, and one of the three divided members is formed to be thicker than the other two divided members. 2. The vehicle body member member according to claim 1, wherein both ends of the thicker divided member are welded by continuous welding to respective one ends of the other two divided members. 4. The vehicle body member member is composed of three divided members, and one of the three divided members is higher in tensile strength than the material forming the other two divided members. The two ends of the divided member made of a material having high tensile strength
3. The vehicle body member member according to claim 2, wherein the two divided members are welded by continuous welding to one end of the two divided members. 5. The vehicle body member according to claim 1, wherein the vehicle body member is a rear side member. 6. The vehicle body member according to claim 1, wherein the vehicle body member is a rear side extension member.