JPH11129757A - Door guard bar for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a door guard bar which is capable of keeping the desired rigidity and strength, increasing the resistance against the bending moment, light in weight, and low in cost. SOLUTION: In a structure where a door guard bar is fitted inward of a door for automobile to keep the strength and rigidity of the door, a body part 3 of a door guard bar 2 is formed of a hollow moldings to provide a door guard bar which is gradually changed in section from the body part 3 of the circular section to the flat and rectangular section toward fitting brackets 4, 5 at each end. A notched part which is a working space for the welding is formed on one long side of the fitting bracket, and the diameter of a center part of the body part 3 of the circular section is larger than the diameter of other body part in the door guard bar. In addition, the body part 3 is of approximately rectangular section, and recessed parts are formed in a wall part opposed to the input of the bending moment from both the inside and the outside of the door.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door guard bar mounted inside a door for an automobile to improve the strength and rigidity of the door.

[0002]

2. Description of the Related Art Conventionally, means for improving door rigidity by mounting a door guard bar 2 on an inner lower side of an automobile door 1 shown in FIG. This door guard bar 2
FIGS. 9A and 9B show a state of attachment to a door according to a sectional view taken along the line A'-A 'in FIG. 8, and as shown in the plan view of FIG. The door guard bar 2 is inserted between the door inner panel 6 and the door outer panel 7 shown in FIG. 8, and the mounting brackets 4, 5 are welded. It is mounted inside the car door 1 by welding and fixing at 8 and 9.

[0003] By setting the section modulus and the second moment of area of the main body 3 to appropriate values, the door guard bar 2 is given appropriate rigidity and resistance to bending moment applied from the outside.

[0004]

In the case of such a conventional door guard bar for an automobile, the main body 3 is usually made of a metal pipe having a circular closed cross section, and a mounting bracket 4 separately prepared for the main body 3 is used. , 5 are fixed by welding or other means, so that the manufacturing process is complicated and heavy,
There is a disadvantage that the material cost is also increased.

Further, since a sudden change in strength is likely to occur between the main body 3 and the mounting brackets 4, 5, there is a problem that sufficient rigidity and resistance to bending moment cannot be obtained.

Accordingly, the present invention solves the above-mentioned problems of the conventional door guard bar for automobiles, and provides a lightweight and low-cost door guard which maintains desired rigidity and strength and has improved resistance to bending moment. It is intended to provide a bar.

[0007]

In order to achieve the above object, the present invention relates to a construction in which a door guard bar for maintaining the strength and rigidity of an automobile door is mounted inside an automobile door. Thus, a door guard bar is provided in which the main body of the door guard bar is formed of a hollow molded product and gradually changes to a flat rectangular cross-sectional shape from the main body having a circular cross-sectional shape toward the mounting brackets at both ends.

According to a second aspect of the present invention, a notch serving as a working space for welding is formed on one of the long sides of the rectangular mounting bracket having a flat cross-sectional shape. An automobile door guard bar is formed so that the diameter of the central portion of the main body is larger than the diameter of the other main body.

According to a fourth aspect of the present invention, the main body of the door guard bar has a substantially rectangular cross-sectional shape, a concave portion is formed in a wall portion facing the input of a bending moment from inside and outside of the door, and both ends are attached from the main body. Provided is a door guard bar for an automobile, which gradually changes to a flat rectangular cross-sectional shape toward a bracket.

According to the door guard bar for a vehicle according to the first aspect, the main body, which is a portion where the bending moment applied from the outside to the door guard bar in the vehicle-mounted state is the largest, has a circular cross-sectional shape, and is attached from the main body to both ends. Since it gradually changes to a flat rectangular cross-sectional shape as it goes toward the mounting bracket, such a change does not cause a sudden change in strength between the main body and the mounting bracket,
Strength and rigidity and resistance to bending moments are kept high.

The notch formed in the mounting bracket provides a working space for performing welding. According to the door guard bar of the third aspect, since the diameter of the central portion where the bending moment applied from the outside is the largest is configured to be larger than the diameter of the other main body, the bending against the bending moment is reduced. Improves resistance.

According to the door guard bar of the fourth aspect, since the concave portion opposes the input of the bending moment from inside and outside of the door to the door guard bar in the vehicle-mounted state, the resistance to the bending moment increases, The strength of the door guard bar itself is improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, a specific embodiment of a door guard bar for an automobile according to the present invention will be described.
The same components as those of the conventional configuration are denoted by the same reference numerals and will be described in detail. In the door guard bar 2 of the first embodiment shown in FIG. 1, reference numeral 3 denotes a main body formed of a hollow molded product, and mounting brackets 4, 5 are provided at both ends of the main body 3.
Are integrally formed. Therefore, the door guard bar 2 is constituted by the main body 3 and the mounting brackets 4 and 5.

FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG.
FIG. 3 is a cross-sectional view of B, and as shown in FIG. 2, the mounting bracket 4 has a structure in which a cross-sectional shape is a flat rectangular shape and a cutout 4 a is formed on one of the long sides. The same applies to the cross-sectional shape of the other mounting bracket 5. Further, as shown in FIG. 3, the main body 3 has a circular cross-sectional shape. As described later in detail, the notch 4a of the mounting brackets 4 and 5
Forms a working space for welding.

The door guard bar 2 in this embodiment is composed of a main body 3 having a circular cross section and mounting brackets 4 and 5 at both ends.
The shape gradually changes to a flat rectangular cross-sectional shape as it goes toward the main body 3.
There is a feature that a sudden change in strength does not occur between the mounting brackets 4 and 5.

As shown in FIG. 4, which is a cross-sectional view taken along the line CC of FIG. 1, in a vehicle mounted state, a welding operation utilizing the notch 4a with the door guard bar 2 in contact with the door inner panel 6 of the vehicle. By forming the welded portions 10 and fixing the mounting brackets 4 and 5 to the door inner panel 6 and further attaching the door outer panel 7 in a predetermined process,
The door guard bar 2 is welded and fixed to the door side to be in a vehicle-mounted state.

Therefore, according to the first embodiment, the main body 3, which is the portion where the bending moment applied from the outside to the door guard bar 2 in the vehicle-mounted state is the largest, has a circular cross-sectional shape.
The shape was gradually changed to a flat rectangular cross section from the main body portion 3 toward the mounting brackets 4 and 5 at both ends, and a cutout portion 4a serving as a working space for welding to the mounting brackets 4 and 5 was formed. This is a structural feature. By using such a door guard bar 2, it is possible to maintain high strength, rigidity and resistance to bending moment required for the door guard bar 2 in a vehicle-mounted state.

Further, since the door guard bar 2 of the present embodiment does not use a metal pipe having a circular closed cross section having a constant pipe diameter and a plate thickness unlike the conventional door guard bar, the weight of the door guard bar itself is reduced. In addition, there is a feature that the material cost is reduced.

FIG. 5 shows the structure of a door guard bar 2 according to a second embodiment of the present invention. Since the basic structure is the same as that of the first embodiment, the same reference numerals are used to denote them. I have. In this example, as shown in FIG. 6 which is a cross-sectional view taken along the line DD of FIG.
Was a substantially rectangular cross-sectional shape, and the input of the bending moment from the door and out M _1, the recess in the wall portion opposed to the M ₂ 3a, 3
b is formed. Other structures are the same as those of the first embodiment.

According to the second embodiment, the concave portions 3a and 3b oppose the bending moment inputs M ₁ and M ₂ from the inside and outside of the door to the door guard bar 2 in a vehicle-mounted state. The resistance to the bending moment increases, and as a result, the strength of the door guard bar 2 itself can be improved.

FIG. 7 shows the structure of a door guard bar 2 according to a third embodiment of the present invention. Since the basic structure is the same as that of the first embodiment, the same reference numerals are used. I have. In this example, the radius vector length K ₁ of a circular cross-sectional shape composed of a hollow molding body portion 3 of the central portion 3c (the hatched portion) is greater than the diameter length K ₂ for the other of the body portion 3 Have been.

At both ends of the main body 3, mounting brackets 4 and 5 are integrally formed. As described with reference to FIG. 2, the mounting brackets 4 and 5 have a flat rectangular cross section and have a structure in which a cutout 4a is formed on one of the long sides. The cross section gradually changes to a flat rectangular cross section from the central portion 3c of the circular cross section toward the main body 3 and the mounting brackets 4 and 5 at both ends.

According to the third embodiment, the diameter K ₁ of the central portion 3 c, which is the portion where the bending moment applied from the outside to the door guard bar 2 in the vehicle-mounted state is the maximum, is the diameter K of the other main body 3. _Since it is configured to be larger than ₂ , it is possible to withstand such a bending moment and to maintain the strength and rigidity required as a door guard bar higher, and to attach the mounting brackets at both ends from the central portion 3c. 4 and 5, the shape gradually changes to a flat rectangular cross-sectional shape. Such a change in the cross-sectional shape causes a sudden change in strength between the central portion 3c and the main body 3 and the mounting brackets 4 and 5. Is obtained.

[0024]

As described above in detail, according to the door guard bar for an automobile according to the first aspect of the present invention, the main body portion where the bending moment applied from the outside to the door guard bar is the largest has a circular cross-sectional shape. Since the shape gradually changes to a flat rectangular cross section from the main body to the mounting bracket at both ends, there is no sudden change in strength between the main body and the mounting bracket, and strength and rigidity And the resistance to bending moment can be maintained high.

According to the door guard bar of the third aspect,
By configuring the diameter of the central portion where the bending moment applied from the outside is the largest, larger than the diameter of the other main body, the resistance to the bending moment is improved. Further, according to the door guard bar of the fourth aspect, the main body has a substantially rectangular cross-sectional shape and a concave portion is formed in the wall facing the input of the bending moment from inside and outside of the door, so that the door guard bar can be bent from inside and outside of the door. The concave portion opposes the input of the moment, the resistance to the bending moment increases, and the effect of improving the strength of the door guard bar itself is obtained.

In particular, since a metal pipe having a circular closed cross section having a constant pipe diameter and plate thickness as in the conventional door guard bar is not used, the weight of the door guard bar itself is reduced,
In addition, the effect of reducing material costs can be obtained.

[Brief description of the drawings]

FIG. 1 is a first view of an automobile door guard bar according to the present invention.
FIG. 2 is a plan view showing the embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a cross-sectional view taken along the line CC of FIG. 1 in a vehicle-mounted state.

FIG. 5 is a plan view showing a second embodiment of the present invention.

FIG. 6 is a sectional view taken along line DD of FIG. 5;

FIG. 7 is a plan view showing a third embodiment of the present invention.

FIG. 8 is a side view showing an automobile door.

FIG. 9 is a view showing a state where the door guard bar is attached to the door.
A′-A ′ sectional view of FIG.

FIG. 10 is a plan view of a conventional door guard bar.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Door 2 ... Door guard bar 3 ... Body part 3a, 3b ... Recess 3c ... Central part 4, 5 ... Mounting bracket 6 ... Door inner panel 7 ... Door outer panel 10 ... Welded part

Claims (4)

[Claims] 1. A structure in which a door guard bar for maintaining strength and rigidity of a door is mounted inside a door for an automobile, wherein the main body of the door guard bar is formed of a hollow molded product, and has a circular cross-sectional shape. A door guard bar for an automobile, wherein the cross section is gradually changed to a flat rectangular cross section from a portion toward a mounting bracket at both ends. 2. A door guard bar for an automobile according to claim 1, wherein a notch portion serving as a working space for welding is formed on one of the long sides of the rectangular mounting bracket having a flat cross section. 3. A door guard bar for an automobile according to claim 1, wherein a diameter of a central portion of the main body having a circular cross-sectional shape is formed to be larger than a diameter of another main body. . 4. A structure in which a door guard bar for maintaining strength and rigidity of a door is mounted inside a door for an automobile, wherein the main body of the door guard bar has a substantially rectangular cross-sectional shape, and A door guard bar for an automobile, wherein a concave portion is formed in a wall portion facing the input of a bending moment, and the shape of the door guard bar is gradually changed to a flat rectangular cross section from the main body portion toward the mounting bracket at both ends.