KR20200109736A - Cross member for car - Google Patents

Abstract

The present invention relates to a cross member for a vehicle, which can reduce the number of parts and processes through integration and optimization of a shape, thereby reducing weight and costs. The cross member for a vehicle according to an embodiment includes: a first tubular unit extended in a longitudinal direction; and a second tubular unit extended in the longitudinal direction and having a cross-sectional shape different from that of the first tubular unit. The first tubular unit and the second tubular unit are integrally formed.

Description

Cross member for car {Cross member for car}

The present invention relates to a cross member for a vehicle such as a cowl cross member, which is capable of reducing weight and cost by reducing the number of parts and processes through integration and optimization of shape.

In general, in a vehicle, a cross member is installed in the width direction of the vehicle body to increase the strength or rigidity of the vehicle body and prevent the vehicle body from twisting or bending in the front and rear and left and right directions.

For example, a cross member such as a cowl cross member is a structure that is installed in the width direction at the rear of the cowl panel to provide rigidity to the front of the vehicle body to protect passengers in a frontal collision. In addition, the cowl cross member supports the steering column and is designed to have a rigid structure capable of sufficiently absorbing the vibration of the engine transmitted from the steering column. In addition, since brackets for installing instrument panels, air conditioning ducts, sound devices, fuse boxes, airbags, pedals, etc. are installed on the cowl cross member, the cowl cross member must have rigidity to support the above-described mechanism or device. .

In the conventional cowl cross member, a pipe with a circular cross section is applied.For light weight and support rigidity, a pipe with a large diameter is arranged on the driver's seat side and a pipe with a relatively small diameter is arranged on the passenger side. I am using it.

Separate additional parts are required for the connection of two pipes of different diameters, and a welding process for fixing each pipe to these parts is also added. In addition, in order to install a steering system, an air conditioning system, an instrument panel, and various devices and devices for providing safety and convenience to the driver on the cowl cross member, various brackets must be welded and attached.

(Patent Document 1) JP 5667518 B2

Accordingly, an object of the present invention is to provide a cross member for a vehicle capable of reducing weight and cost by reducing the number of parts and processes through integration and optimization of shape.

A vehicle cross member according to an embodiment of the present invention includes a first tubular portion extending in a longitudinal direction, and a second tubular portion extending in the longitudinal direction and having a different cross-sectional shape from the first tubular portion, and the first It is characterized in that the first tubular portion and the second tubular portion are integrally molded.

A vehicle cross member according to another embodiment of the present invention includes a first tubular portion extending in a longitudinal direction, and a second tubular portion extending in the longitudinal direction and having a different number of closed cross-sections than the first tubular portion, It characterized in that the first tubular portion and the second tubular portion is integrally molded.

As described above, according to the present invention, in terms of performance, the rigidity of the cross member may be improved by integrating the conventional separated pipes, and the strength may be increased by removing a welding part for connecting the separated pipes.

In addition, according to the present invention, in terms of weight reduction, since stiffness can be improved through cross-sectional design and optimization of the cross member, it is possible to reduce the weight by reducing the material used compared to the same stiffness.

Moreover, according to the present invention, in terms of cost, additional brackets attached to the cross member can be integrated, so that a separate welding process for attaching these brackets can be reduced, thereby reducing time to improve productivity as well as cost. You will get the effect that can be saved.

1 is a perspective view showing a cowl cross member to which a vehicle cross member according to a first embodiment of the present invention is applied.
2 is a partially enlarged view and a cross-sectional view taken along line II′ of a vehicle cross member according to the first embodiment of the present invention.
3 is a partially enlarged view and a cross-sectional view taken along line II-II' of a vehicle cross member according to the first embodiment of the present invention.
4 is a plan view showing a blank to be molded into a vehicle cross member according to a first embodiment of the present invention.
5 is a perspective view showing a cowl cross member to which a vehicle cross member according to a second embodiment of the present invention is applied.
6 is a partially enlarged view and a cross-sectional view taken along line III-III' of a vehicle cross member according to a second embodiment of the present invention.
7 is a partially enlarged view and a cross-sectional view taken along line IV-IV' of a vehicle cross member according to the second embodiment of the present invention.
8 is a plan view showing a blank to be formed into a vehicle cross member according to a second embodiment of the present invention.

Hereinafter, the present invention will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible even if they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

1 is a perspective view showing a cowl cross member to which a vehicle cross member according to a first embodiment of the present invention is applied, and FIG. 2 is a partially enlarged view of a vehicle cross member according to a first embodiment of the present invention and I-I' 3 is a partial enlarged view and a cross-sectional view taken along line II-II' of the vehicle cross member according to the first embodiment of the present invention.

As shown in these drawings, the vehicle cross member 10 according to the first embodiment of the present invention includes a first tubular portion 11 extending in the longitudinal direction, and a first tubular portion and a cross-section extending in the longitudinal direction. It includes a second tubular portion 12 having a different shape, and characterized in that the first tubular portion and the second tubular portion are integrally molded.

In describing the vehicle cross member according to the present invention, for convenience, in the present specification, an example in which the cross member is applied to the cowl cross member will be described. However, the application example of the vehicle cross member according to the present invention is not necessarily limited thereto.

For example, the cowl cross member includes a cross member 10 extending in the width direction of the vehicle body, and a connection stay 31 for connecting the cross member to the cowl panel of the vehicle body by welding at one end to the cross member. Can be equipped.

The cross member 10 includes a first tubular portion 11 constituting a driver's seat side portion and a first tubular portion extending from the first tubular portion and extending in the longitudinal direction, and the first tubular portion and the cross-sectional shape are formed differently to form the passenger seat side portion. It includes a second tubular portion 12 constituting.

The vehicle cross member 10 according to the first embodiment of the present invention may be formed by a roll forming process, and through the design of a forming blank 1 (see FIG. 4) in consideration of the characteristics of the roll forming process. The first tubular portion 11 and the second tubular portion 12 having different cross-sectional shapes can be integrated and the rigidity of the cross member can be increased.

More specifically, in the vehicle cross member 10 according to the first embodiment of the present invention, the first tubular portion 11 constituting the driver's seat side portion is made of a substantially rectangular metal plate, as shown in FIG. 2. The blank 1 is processed by a roll forming process, and is generally formed in a substantially'Japanese' shape.

For example, the blank 1 is moved from one end (p1) side to the other end (p2) side toward the first side (s1), the first corner (a1), the second side (s2), and the second corner (a2). , After bending the third side (s3), the third edge (a3) and the fourth side (s4) three times in the same direction by approximately 90°, the fourth edge (a4), the fifth side (s5), The fifth corner (a5), the sixth side (s6), the sixth corner (a6), and the seventh side (s7) are bent 3 times in a reverse direction of about 90°, so that a part of the blank is approximately'日'. It can be formed in a cross section of a shape.

Then, one end p1 is welded to the fifth side s5 to form a first joint w1, and the other end p2 is welded to the third side s3 to form a second joint w2. Here, the positions of the first bonding portion w1 and the second bonding portion w2 are not necessarily limited to the example shown in FIG. 2.

Preferably, the first side (s1) and the fifth side (s5) leading to an approximately straight line, and the third side (s3) and the seventh side (s7) leading to an approximately straight line are parallel with the same length, and the second side (s2), the fourth side (s4), and the sixth side (s6) have the same length and are parallel to each other.

Accordingly, the cross-sectional shape of the first tubular portion 11 is symmetric with respect to the support portion 13 composed of the fourth side s4, and two closed cross-sectional portions 15 and 16 separated by the support portion may be provided. have.

The first closed section 15 includes a first side (s1), a first corner (a1), a second side (s2), a second corner (a2), a third side (s3), a third corner (a3), Includes a fourth side (s4) and a first junction (w1), and the second closed cross-section (16) includes a fourth side (s4), a fourth edge (a4), a fifth side (s5), and a fifth edge ( a5), a sixth side s6, a sixth edge a6, a seventh side s7, and a second junction w2.

The two closed cross-sectional portions 15 and 16 formed in the first tubular portion 11 by the support portion 13 may be formed in the same cross-sectional area and the same shape, but are not limited thereto, and the position of the support portion is changed. It is also possible to form the two closed cross-sectional areas to have different cross-sectional areas and different shapes.

In addition, the direction of bending the blank 1, the bending angle, the number of bending, the position at which the joint is formed by welding, etc. are not limited to the above-described examples, and the overall cross-sectional shape is not limited only to the rectangular cross-section, and an arbitrary polygon Of course, it may have a cross-sectional shape of a circle or an ellipse.

When the overall cross-sectional shape of the first tubular portion 11 is a circle or an ellipse, the blank 1 may be formed by bending the blank 1 from one end to the other end at least twice.

In the vehicle cross member 10 according to the first embodiment of the present invention, the support portion 13 is arranged in a form that divides the inner space of the cross section of the first tubular portion 11 constituting the driver's seat side portion, thereby While minimizing the increase in weight, there is an advantage of controlling the stiffness of the cross section by reinforcing the stiffness.

In the first tubular portion 11 constituting the driver's seat side portion of the cross member 10, for example, when the cross member is applied to the cowl cross member, a connection stay for connecting the cross member to the cowl panel of the vehicle body ( One end of 31) may be joined by welding or the like.

On the other hand, in the vehicle cross member 10 according to the first embodiment of the present invention, the second tubular portion 12 constituting the passenger seat side portion is, as shown in FIG. 3, the blank made of a substantially rectangular metal plate. (1) is processed by a roll forming process, and the whole is formed into a substantially'口' shape.

For example, the blank 1 is moved from one end (p1) side to the other end (p2) side toward the first side (s1), the first corner (a1), the second side (s2), and the second corner (a2). , The third side (s3), the third edge (a3), and the fourth side (s4) are bent three times in the same direction in the same direction by about 90° so that a part of the blank can be formed in an approximately'口'-shaped cross section. have.

Subsequently, the other end p2 is welded to the first side s1 to form a third joint w3. Here, the position of the third bonding portion w3 is not necessarily limited to the example shown in FIG. 3.

Preferably, the first side (s1) and the third side (s3) are of the same length and are parallel to each other, and the second side (s2) and the fourth side (s4) are of the same length and are parallel to each other.

Accordingly, the cross-sectional shape of the second tubular portion 12 may include one closed cross-sectional portion 18, and the closed cross-sectional portion is a first side (s1), a first edge (a1), a second side (s2) , A second edge (a2), a third side (s3), a third edge (a3), a fourth side (s4), and a third junction (w1).

The closed cross-sectional portion 18 of the second tubular portion 12 may have the same shape and the same size as the first closed cross-sectional portion 15 of the first tubular portion 11, but is not limited thereto.

In addition, the overall cross-sectional shape of the second tubular portion 11 is not limited only to a polygon. For example, when the cross-sectional shape of the second tubular portion 11 is a circle or an elliptical shape, the blank 1 is moved from one end to the other. It may be formed by bending toward the side at least once.

In the vehicle cross member 10 according to the first embodiment of the present invention, in the second tubular portion 12 constituting the passenger seat side portion, for example, when the cross member is applied to the cowl cross member, an additional mechanism or The bracket 32 for installing the device may be integrally formed.

The brackets 32 may be formed in plural, and in this case, the plurality of brackets may be integrally formed with the second tubular portion 12 at a predetermined interval along the longitudinal direction of the cross member 10.

As described above, in the cross member 10 of the present invention, instead of connecting pipes separated by welding or the like and attaching brackets in the prior art, a first having a different cross-sectional shape from a single blank 1 by a roll forming process The tubular portion 11 and the second tubular portion 12 are integrally formed, and, for example, a substantially plate-shaped bracket 32 may be integrally formed with the cross member to be implemented.

Accordingly, the cross member 10 of the present invention can secure the dimensional accuracy of the first tubular portion 11, the second tubular portion 12, and the bracket 32 integrally formed. In addition, since the cross member is integrally molded without a separate welding process, the cross member of the present invention can reduce the welding process, as well as positional shift, distortion, deformation, etc. that occur in the case of conventional welding or the like. Can be prevented at the source.

In particular, the vehicle cross member 10 according to the present invention has excellent workability and assembly properties, and has an advantage that can be formed at low cost. In addition, productivity can be improved by increasing the speed of the production line, which is slowed down by the welding process, and costs related to welding are reduced, so that cost reduction is also possible.

In addition, for example, when the vehicle cross member 10 according to the first embodiment of the present invention is applied to the cowl cross member, the connecting plate 33 is at the end of the second tubular portion 12 on the passenger side of the cross member. Can be joined by welding.

Likewise, the connection plate 33 may be joined to the end of the first tubular portion 11 on the driver's seat side of the cross member 10 by welding.

Each connection plate 33 may have a bolt hole for connecting the cross member 10 to one frame of the vehicle body with a bolt. However, the method for connecting the vehicle body and the cross member is not necessarily limited thereto, and any other method may be selected as necessary.

Hereinafter, the manufacturing process of the vehicle cross member according to the first embodiment of the present invention will be briefly described.

First, a process of preparing a blank 1 made of a metal plate having the same shape as in the plan view of FIG. 4 is required.

For example, it can be prepared by forming a blank 1 having a shape matching the developed view of the cross member 10 through an uncoiler through an uncoiler, such as a coil-shaped steel sheet, using a press or the like. have.

The blank 1 includes, for example, a first portion 3 having a substantially constant width to form the first tubular portion 11 of the cross member 10 of the cowl cross member, which is a final product, and one end of the first portion in the longitudinal direction. The second part 4 is connected to and decreases in width to form the second tubular part 12, and the bracket 32 protrudes so as to extend in the width direction of the second part from the middle of the second part in the longitudinal direction. It may include at least one extension part 5 to form.

The blank 1 may be bent several times by a roll forming process, so that the overall cross-sectional shape may be formed into a substantially rectangular shape. However, as described above, the overall cross-sectional shape is not limited to a rectangular cross-section, and may have an arbitrary polygonal, circular, or elliptical cross-sectional shape.

For example, by a roll forming process, the first closed end portion 15 of the first tubular portion 11 and the closed end face portion 18 of the second tubular portion 12 are molded together, and then the first tubular portion The second closed section 16 may be molded.

Next, in order to fix and complete the shape of each of the closed cross-sections, the ends are welded to other parts of the blank, such as adjacent sides or corners, to form a corresponding joint.

When the vehicle cross member 10 according to the first embodiment of the present invention is applied to the cowl cross member, the extension part 5 is selectively bent or molded using, for example, a press, and the extension part A hole of a predetermined shape can be drilled to form a perforation.

After that, for example, it is cut or finished, leaving only the dimensions of the cross member 10 of the final product, the cowl cross member.

Accordingly, the vehicle cross member 10 according to the first embodiment of the present invention includes a first tubular portion 11 and a second tubular portion having a cross-sectional shape different from that of the cross-sectional shape of the first tubular portion ( 12) can be integrally molded together. In addition, a plurality of brackets 32 may be integrally formed in the vehicle cross member according to the first embodiment of the present invention.

For the vehicle cross member 10 according to the first embodiment of the present invention, the present applicant performed a three-point bending analysis to verify its performance. For example, a cross member in which pipes were welded according to the prior art, and both ends of the cross member in the longitudinal direction of the present invention were fixed, and a reduction of about 30 mm was applied to a portion where the cross-sectional shape is changed.

Compared to the prior art, the load point reaction force of the cross member of the present invention is increased, and in particular, the cross member of the present invention exhibits a reaction force value of twice or more compared to the prior art.

In the cross member according to the prior art, two pipes having different diameters are welded to each other, whereas the vehicle cross member 10 according to the first embodiment of the present invention has a first tubular portion 11 and a second tubular portion ( Since 12) is integrally molded and connected, it can be seen that it is advantageous in terms of reaction force performance.

In addition, with respect to the vehicle cross member 10 according to the first embodiment of the present invention, the present applicant performed a torsional strength analysis in order to verify its performance. For example, in the longitudinal direction of the cross member according to the prior art and the cross member of the present invention, one end, that is, the passenger seat side is fixed, and the driver's seat side is twisted by about 30 degrees.

Compared to the prior art, the torsional strength of the cross member of the present invention was equal to or higher than that of the prior art.

In the cross member according to the prior art, two pipes having different diameters are connected to each other by welding, so that a phenomenon in which stress is concentrated near the welded portion occurs, whereas the vehicle cross member 10 according to the first embodiment of the present invention Since the first tubular portion 11 and the second tubular portion 12 are integrally formed and connected without a welding portion, it is possible to increase the torsional strength.

5 is a perspective view showing a cowl cross member to which a vehicle cross member according to a second embodiment of the present invention is applied, and FIG. 6 is a partial enlarged view of a vehicle cross member according to the second embodiment of the present invention and III-III' 7 is a partial enlarged view and a cross-sectional view taken along line IV-IV' of a vehicle cross member according to a second embodiment of the present invention.

As shown in these drawings, the vehicle cross member 20 according to the second embodiment of the present invention includes a first tubular portion 21 extending in the longitudinal direction and a first tubular portion 21 extending in the longitudinal direction and different from the first tubular portion. It includes a second tubular portion 22 having a number of closed cross-sections, characterized in that the first tubular portion and the second tubular portion are integrally molded.

In the vehicle cross member 20 according to the second embodiment of the present invention, only the cross-sectional shape of the first tubular portion 21 and the number of the closed cross-sectional portions are different, and the remaining configurations are the cross member 10 of the first embodiment described above. ). Accordingly, in describing the vehicle cross member according to the second embodiment of the present invention, detailed descriptions of the configuration and operation of the same components as those of the cross member according to the first embodiment will be omitted.

The vehicle cross member 20 according to the second embodiment of the present invention may be formed by a roll forming process, and the closed cross-section through the design of the forming blank 1'(see FIG. 8) in consideration of the characteristics of the roll forming process The first tubular portion 21 and the second tubular portion 22 having different numbers of can be integrated and the rigidity of the cross member can be increased.

More specifically, in the vehicle cross member 20 according to the second embodiment of the present invention, the first tubular portion 21 constituting the driver's seat side portion is made of a substantially rectangular metal plate, as shown in FIG. 6. The blank 1'is processed by a roll forming process to form a plurality of, for example, three closed cross-sections.

From the middle of the blank (1') toward the end (p1) side, the first side (s1), the first edge (a1), the second side (s2), the second edge (a2) and the third side (s3) After bending twice in the same direction in the same direction in the order of about 90°, bending in the opposite direction at the third corner (a3), and then again, the fourth side (s4), the fourth corner (a4), the fifth side (s5), The fifth edge (a5), the sixth side (s6), the sixth edge (a6), and the seventh side (s7) are bent three times in the same direction in the same direction by about 90°.

In addition, from the middle of the blank 1'toward the other end (p2) side, the first side (s1), the seventh edge (a7), the eighth side (s8), the eighth edge (a8) and the ninth side ( After bending twice about 90° in the same direction in the order of s9), bending it in the opposite direction at the ninth edge (a9), and then again, the tenth side (s10), the tenth edge (a10), and the eleventh side (s11) ), the eleventh corner (a11), the twelfth side (s12), the twelfth corner (a12), and the thirteenth side (s13) are bent three times in the same direction in the same direction by approximately 90°.

As a result, a part of the blank may be formed in an approximately'品'-shaped cross section.

Subsequently, the third edge (a3) and the ninth edge (a9) are welded to each other to form a first junction (w1), and one end (p1) is welded to the fourth side (s4) to form a second junction (w2). And the other end (p2) is welded to the tenth side (s10) to form a third joint (w3). Here, the positions of the first bonding portion w1, the second bonding portion w2, and the third bonding portion w3 are not necessarily limited to the example shown in FIG. 6.

Accordingly, the cross-sectional shape of the first tubular portion 21 is symmetric with respect to the welding line of the first joint w1 formed by welding of the third corner a3 and the ninth corner a9, while three closed cross-sectional portions 25 , 26, 27) can be provided.

The first closed section 25 includes a first side (s1), a first corner (a1), a second side (s2), a second corner (a2), a third side (s3), a third corner (a3), Includes a first junction (w1), a ninth edge (a9), a ninth side (s9), an eighth edge (a8), an eighth side (s8), and a seventh edge (a7), and a second closed cross-section (26) is the fourth side (s4), the fourth edge (a4), the fifth side (s5), the fifth edge (a5), the sixth side (s6), the sixth edge (a6), the seventh side ( s7) and a second junction (w2), and the third closed cross-section (27) includes a tenth side (s10), a tenth edge (a10), an eleventh side (s11), an eleventh edge (a11), and It may include a 12 side (s12), a 12th edge (a12), a 13th side (s13), and a third junction (w3).

Among the three closed cross-sections formed in the first tubular portion 21, the second and third closed cross-sections 26 and 27 may have the same cross-sectional area and the same shape, but are not necessarily limited thereto, and welding It is also possible to change the position to form the second and third closed cross-sections to have different cross-sectional areas and different shapes.

In addition, the direction of bending the blank 1', the bending angle, the number of bending, and the position at which the joint is formed by welding are not limited to the above-described examples, and the cross-sectional shape and number of the closed cross-section are also limited to the above-described examples. It can be modified and changed in various ways without being used.

On the other hand, in the vehicle cross member 10 according to the second embodiment of the present invention, the second tubular portion 22 constituting the passenger seat side portion is, as shown in FIG. 7, the blank made of a substantially rectangular metal plate. (1') is processed by a roll forming process, and it is formed in an approximately'口' shape as a whole.

For example, from the middle of the blank (1') toward the end (p1) side, the first side (s1), the first edge (a1), the second side (s2), the second edge (a2) and the third After bending two times in the same direction in the order of the sides (s3) by approximately 90°, bending the third edge (a3) in the opposite direction, and then removing the blank (1') from the middle toward the other end (p2). 1 side (s1), the fourth edge (a4), the fourth side (s4), the fifth edge (a5), and the fifth side (s5) are bent twice in the same direction in the same direction by approximately 90° to form part of the blank. It may be formed in an approximately'口'-shaped cross section.

Subsequently, the other end p2 is welded to the third edge s3 to form a fourth joint w4. Here, the position of the fourth junction w4 is not necessarily limited to the example shown in FIG. 7.

Preferably, the second side s2 and the fourth side s4 have the same length and are parallel to each other, and the third side s3 and the fifth side s5 have the same length and are symmetrical.

Accordingly, the cross-sectional shape of the second tubular portion 22 may have one closed cross-sectional portion 28, and the closed cross-sectional portion is a first side (s1), a first edge (a1), and a second side (s2). ), the second edge (a2), the third side (s3), the fourth junction (w4), the fifth side (s5), the fifth edge (a5), the fourth side (s4), and the fourth edge (a4) ) Can be included.

The closed cross-sectional portion 28 of the second tubular portion 22 may have the same shape and the same size as the first closed cross-sectional portion 25 of the first tubular portion 21, but is not limited thereto.

In the vehicle cross member 20 according to the second embodiment of the present invention, in the second tubular portion 22 constituting the passenger seat side portion, for example, when the cross member is applied to the cowl cross member, an additional mechanism or The bracket 32 for installing the device may be integrally formed.

The brackets 32 may be formed in plural, and in this case, the plurality of brackets may be integrally formed with the second tubular portion 22 at a predetermined interval along the longitudinal direction of the cross member 20.

As described above, in the cross member 20 of the present invention, instead of connecting pipes separated by welding or the like and attaching brackets in the prior art, different cross-sectional shapes and different closing ends from a single blank 1'by a roll forming process. The first tubular portion 21 and the second tubular portion 22 having the number of surface portions are integrally formed, and, for example, a substantially plate-shaped bracket 32 can be integrally formed with the cross member.

Hereinafter, the manufacturing process of the vehicle cross member according to the second embodiment of the present invention will be briefly described.

A process of preparing a blank 1'made of a metal plate having the same shape as in the plan view of FIG. 8 is required.

For example, it may be prepared by forming a blank 1'having a shape matching the developed view of the cross member 20 through an uncoiler through a metal base material such as a coil-shaped steel plate using a press or the like.

The blank 1'is, for example, a first portion 3 having a substantially constant width to form the first tubular portion 21 of the cross member 20 of the final product, the cowl cross member, and the longitudinal direction of the first portion A second portion 4 connected to one end and decreasing in width to form a second tubular portion 22, and a bracket 32 protruding so as to extend in the width direction of the second portion from the middle of the second portion in the longitudinal direction. It may include at least one extension part 5 to form a ).

The blank 1 ′ may be bent several times by a roll forming process so that the overall cross-sectional shape may be formed into an approximately polygonal shape. However, the overall cross-sectional shape is not limited thereto, and may have a circular or elliptical cross-sectional shape other than a polygon.

In addition, some of the blanks 1'may be bent several times by a roll forming process to form a plurality of closed cross-sections.

For example, by a roll forming process, the first closed end portion 25 of the first tubular portion 21 and the closed end portion 28 of the second tubular portion 22 are molded together, and then the first tubular portion The second and third closed cross-sections 26 and 27 may be molded.

Next, in order to fix and complete the shape of each of the closed cross-sections, the ends are welded to other parts of the blank, such as adjacent sides or edges, to form a corresponding joint. In addition, adjacent edges may be welded to each other to form a joint.

Optionally, preferably prior to welding, bead portions 23 for reinforcing stiffness partially in the first portion 3 which will form the second and third closed cross-section portions 26, 27 of the first tubular portion 21. ) Can be formed (see Fig. 6).

When the vehicle cross member 20 according to the second embodiment of the present invention is applied to the cowl cross member, the extension portion 5 is selectively bent or molded using, for example, a press, and the extension portion is A hole of a predetermined shape can be drilled to form a perforation.

After that, for example, it is cut or finished, leaving only the dimensions of the cross member 20 of the final product, the cowl cross member.

Accordingly, the vehicle cross member 20 according to the second embodiment of the present invention includes a first tubular portion 21 and a second tubular portion 22 having a different number of closed cross-sections than the first tubular portion. It can be integrally molded. In addition, a plurality of brackets 32 may be integrally formed in the vehicle cross member according to the second embodiment of the present invention.

As described above, according to the present invention, when manufacturing a vehicle cross member, the first tubular portion, the second tubular portion, and a plurality of the first tubular portions and the plurality of tubular portions are Brackets can be implemented, thereby improving the rigidity of the cross member, reducing the number of parts and processes, thereby reducing cost and improving productivity.

Therefore, according to the present invention, it is possible to meet the unique structural requirements of the cowl cross member that the first tubular portion on the driver's seat side and the second tubular portion on the passenger side are different by the configuration of the vehicle cross member that can be manufactured at low cost. It becomes.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

1, 1': blank 10, 20: cross member
11, 21: first tubular portion 12, 22: second tubular portion
13: support 15, 25: first closed section
16, 26: second closed section 18, 28: closed section
23: bead part 27: 3rd closed section
31: connection stay 32: bracket
33: connecting plate

Claims (15)

A first tubular portion extending in the longitudinal direction,
A second tubular portion extending in the longitudinal direction and having a different cross-sectional shape from the first tubular portion
Including,
A vehicle cross member in which the first tubular portion and the second tubular portion are integrally formed.
The method of claim 1,
The first tubular portion is formed by bending a metal blank from one end to the other end at least twice,
And a support portion disposed inside the first tubular portion and configured to divide an inner space of a cross-section of the first tubular portion.
The method of claim 2,
In the first tubular portion, a first closed cross-sectional portion is formed by bending the blank in one direction from one end side to the other end side in order from a first corner, a second corner, and a third corner, and then the blank is formed at a fourth corner. , A second closed cross-section is formed by bending in the reverse direction of the one direction at the fifth and sixth corners,
The support portion is a vehicle cross member, characterized in that formed as a side between the third edge and the fourth edge.
The method of claim 3,
The second tubular portion is formed by bending the blank from one end toward the other end at least once.
The method of claim 4,
A cross member for a vehicle, wherein the second tubular portion has a closed cross-section formed by bending the blank from one end side to the other end side in one direction at a first corner, a second corner, and a third corner.
The method of claim 5,
A cross member for a vehicle, wherein the closed cross-sectional portion of the second tubular portion has the same shape and size as the first closed cross-sectional portion of the first tubular portion.
A first tubular portion extending in the longitudinal direction,
A second tubular portion extending in the longitudinal direction and having a different number of closed cross-sections than the first tubular portion
Including,
A vehicle cross member in which the first tubular portion and the second tubular portion are integrally formed.
The method of claim 7,
The first tubular portion is formed by bending a metal blank from one end to the other end at least twice.
The method of claim 8,
The first tubular portion, after bending the blank in one direction at the first and second corners in order from the middle of the blank toward one end side, and then bent at the third corner in the reverse direction of the one direction, and again at the fourth corner, The fifth and sixth edges are bent in the one direction, and the seventh and eighth edges are bent in the reverse direction of the one direction from the middle of the blank toward the other end side, and then bent in the one direction from the ninth corner. And, by bending the tenth, eleventh, and twelfth corners in the reverse direction of the one direction, the vehicle cross member comprising three closed cross-sections.
The method of claim 9,
The second tubular portion is formed by bending the blank from one end toward the other end at least once.
The method of claim 10,
The second tubular portion is bent in one direction at the first and second corners in order from the middle of the blank toward one end, and then bent at the third corner in the reverse direction of the one direction, and the other end at the middle of the blank A cross member for a vehicle, characterized in that the closed cross-section is formed by bending the fourth edge and the fifth edge in the reverse direction of the one direction in order toward the side.
The method of claim 11,
A cross member for a vehicle, wherein the closed cross-section of the second tubular portion has the same shape and size as one of the closed cross-sectional portions of the first tubular portion.
The method according to claim 2 or 8,
The first tubular portion and the second tubular portion are each formed by bending the blank by roll forming, and welding at least one of one end and the other end of the blank to another portion of the blank. .
The method according to claim 2 or 8,
The blank includes at least one extension portion extending and protruding in the width direction of the blank,
The cross member for a vehicle, wherein the extension portion constitutes a bracket in which the second tubular portion is integrated.
The method according to claim 2 or 8,
A cross member for a vehicle, wherein a bead portion for reinforcing rigidity is formed at least partially in the first tubular portion.

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