CN104691464A - Vehicular longitudinal metal energy absorbing box with variable wall thickness and preparation method thereof - Google Patents

Abstract

A metal energy-absorbing box with longitudinally variable wall thickness for vehicles and a preparation method thereof belong to the technical field of metal products. It is characterized in that the wall thickness of the energy-absorbing box consists of at least one thickness transition zone, or at least one equal thickness zone and at least one thickness transition zone. The form of the thickness transition zone can be linear, and can also be in the form of curves, broken lines or multi-segment curves. The cross-section of the energy-absorbing box with variable wall thickness can be in various forms such as circular, elliptical or polygonal; its preparation method is to roll the variable-thickness plate according to its thickness requirements, and cut it into blanks; cold-bend the blanks and weld them into the Variable wall thickness crash boxes required. Compared with the energy-absorbing box with equal thickness and induction groove, the variable-wall-thickness energy-absorbing box has the advantages of optimizing crash performance, reducing weight, and reducing cost.

Description

A metal energy-absorbing box with longitudinally variable wall thickness for vehicles and its preparation method

technical field

The invention belongs to the field of metal material products, in particular to a metal energy-absorbing box for vehicles and a preparation method thereof.

Background technique

The number of automobiles in our country is increasing rapidly, and traffic accidents are also increasing year by year. Among them, frontal or mainly frontal collision accidents account for about 66.9% of all collision accidents. How to improve the anti-collision performance of automobiles in the process of frontal collision has become a crucial link. The energy-absorbing box is installed between the anti-collision beam and the longitudinal beam of the car body, and is an important component of the front and rear buffer energy-absorbing areas of the car. When the vehicle collides with other vehicles or obstacles, in order to protect the personal safety of the passenger compartment and passengers, the energy-absorbing box first deforms and absorbs a large part of the collision kinetic energy. Therefore, it is of practical significance to carry out research on the characteristics of automobile crash boxes to improve automobile safety and protect the health and life of occupants.

The existing energy-absorbing box has a welded structure of equal wall thickness made of steel materials, but there are the following problems:

1. In order to exert the energy-absorbing effect when the car is hit, and to control the directional and positioning deformation during its crushing process, it is necessary to laterally press the induction groove on the energy-absorbing box so that the collapsed part of the car will be damaged when it is hit. However, when the induction groove is made on the energy-absorbing box, it is necessary to add a forming process, which significantly increases the processing cost of the energy-absorbing box;

2. The equal-wall thickness energy-absorbing box with induction grooves has a small range of external force required for collapse, and the energy-absorbing effect is limited, and when the crushing condition is reached (that is, the overall crushing occurs), it cannot achieve the following Gradual crushing method to increase the energy absorption effect.

Aiming at the above-mentioned technical problems, a plan for a longitudinally variable wall-thickness energy-absorbing box is proposed in order to improve the performance and cost of the currently used energy-absorbing box materials.

Contents of the invention

The invention aims to provide an energy-absorbing box with longitudinally variable wall thickness for vehicles and a preparation method thereof. Compared with an energy-absorbing box with equal-wall thickness with induction grooves, the energy-absorbing effect can be improved while reducing weight and cost.

The energy-absorbing box provided by the present invention is a metal energy-absorbing box with longitudinally variable wall thickness. The installation position of the energy-absorbing box is shown in Figure 1. The two ends of the energy-absorbing box 3 pass through the front connecting plate 2 and the rear connecting plate. 4 is installed between the anti-collision beam 1 and the longitudinal beam 5 of the vehicle body. Crushing deformation occurs when the vehicle collides, thereby reducing the damage to the passenger compartment and occupants caused by the impact force.

The invention provides a novel metal energy-absorbing box with the characteristic of longitudinally variable wall thickness and a manufacturing method thereof. The specific structure of the crash box is shown in Fig. 2 to Fig. 13 .

According to one aspect of the present invention, a metal crash box for vehicles is provided, which is characterized in that the wall thickness of the crash box in the longitudinal or axial direction consists of at least one thickness transition zone, or at least one equal thickness zone It is composed of at least one thickness transition area, and the thicknesses of different equal thickness areas can be the same or different, and the equal thickness areas of different thicknesses are connected by thickness transition areas. For example:

(1) The wall thickness of the energy-absorbing box mentioned above can be changed in the way of thinning in the middle and thickening at both ends in the longitudinal direction, as shown in Figure 2 and Figure 3, at this time, yielding occurs first in the middle;

(2) The above-mentioned way of changing the wall thickness of the energy-absorbing box can be thick in the middle along the longitudinal direction and thin at both ends, as shown in Figure 2 and Figure 4, at this time, the two ends yield first;

(3) The way of changing the thickness of the wall thickness of the energy-absorbing box mentioned above can be gradually thickened from one end to the other end, as shown in Figure 2 and Figure 5, at this time, yielding occurs first from the thin end;

According to an exemplary embodiment of the present invention, the thickness transition zone that connects the equal-thickness zones with the same or different thicknesses can be in a linear form, or in the form of curves, broken lines and multi-segment curves. The shape of the thickness transition curve can be a straight line, a curved line, a broken line or a multi-segment curve. The length and shape of a straight line or curve with variable thickness can be designed according to the load of the energy-absorbing box and the energy-absorbing requirements, as shown in Figure 6, Figure 7 and Figure 8 .

According to an exemplary embodiment of the present invention, the cross-section of the metal crash box with longitudinally variable wall thickness for vehicles can be circular, oval, square, rectangular and polygonal, as shown in Fig. 9, Fig. 10, Fig. 11, Fig. 12 and Fig. As shown in 13, one end of the energy-absorbing box is connected with the anti-collision beam of the automobile, and the other end is connected with the longitudinal beam of the vehicle body.

According to another aspect of the invention, a production process for preparing the above-mentioned metal energy-absorbing box with longitudinally variable wall thickness for vehicles is provided as follows:

1. Use variable thickness rolling technology to roll equal-thickness steel plates into longitudinally variable-thickness plates, and the method of longitudinally variable thickness is the same as that required for energy-absorbing boxes;

2. Cut the above-mentioned variable-thickness steel plate according to the specifications and sizes required by the energy-absorbing box, and use it as the blank of the energy-absorbing box;

3. Form the above-mentioned blank into the shape of the energy-absorbing box by cold bending forming method, as shown in Fig. 9, Fig. 10, Fig. 11, Fig. 12 and Fig. 13;

4. Weld the formed energy-absorbing box along the gap formed after forming to form a closed energy-absorbing box component.

The above-mentioned parts of the energy-absorbing box are assembled between the anti-collision beam and the longitudinal beam of the vehicle body to form an anti-collision-energy-absorbing structure.

The energy-absorbing box realized by the present invention has the following characteristics:

(1) The novel variable-wall-thickness energy-absorbing box of the present invention adopts the idea that the wall thickness changes gradually along the longitudinal direction, and is made of differential-thickness steel plates with the characteristic of longitudinally variable thickness. The energy-absorbing box has the characteristic of first yielding at the thinner wall, even if it is not pressed, it will also yield in orientation and positioning when it is hit, thereby simplifying the production process and reducing production costs;

(2) Due to the feature of variable wall thickness, the novel energy-absorbing box of the present invention can reduce structural weight, save metal materials, and reduce production costs;

(3) By controlling the degree of variable wall thickness, it can be controlled that after the initial crushing of the energy-absorbing box, it is necessary to increase the load to continue to increase the crushing amount, thereby controlling the overall energy-absorbing effect.

Description of drawings

Figure 1 is a schematic diagram of the assembly of energy-absorbing components for vehicles. Among them, 1 is the anti-collision beam, 2 is the front connecting plate, 3 is the energy-absorbing box, 4 is the rear connecting plate, and 5 is the longitudinal beam of the vehicle body.

Fig. 2 is a schematic diagram of a crash box according to an exemplary embodiment of the present invention. Wherein 6 is the front end face and 8 is the rear end face, which are respectively connected to the front connecting plate (2) and the rear connecting plate (4) during installation and use; 7 is the box body part with wall thickness variation.

Fig. 3 is a cross-sectional view taken along the A-A plane of Fig. 2, and the wall thickness variation mode is thick at both ends and thin in the middle. 9 is the thickness transition area, and the thickness transition form can be linear, and can also be in the form of curves, broken lines and multi-segment curves.

Fig. 4 is a cross-sectional view taken along the A-A plane of Fig. 2, and the wall thickness variation mode is thin at both ends and thick in the middle. 10 is a thickness transition zone, and the thickness transition form can be linear, or in the form of curves, broken lines and multi-segment curves.

Fig. 5 is a cross-sectional view taken along the A-A plane of Fig. 2, and the wall thickness variation mode is thick at one end and thin at the other end. 11 is the thickness transition area, and the thickness transition form can be linear, and can also be in the form of curves, broken lines and multi-segment curves.

Fig. 6 is a partial enlarged view of the area indicated by 9 in Fig. 3, showing that the thickness transition form is in the form of a curve, but in fact it can also be in the form of a linear, broken line or multi-segment curve.

Fig. 7 is a partial enlarged view of the area indicated by 10 in Fig. 4, showing that the thickness transition form is in the form of multi-segment broken lines, and in fact it can also be in the form of linear, curved or multi-segment curves.

Fig. 8 is a partially enlarged view of the area indicated by 11 in Fig. 5, showing that the thickness transition form is linear, but in fact it can also be in the form of broken lines, curves or multi-segment curves.

Fig. 9 is a schematic diagram of the circular end face of the crash box.

Fig. 10 is a schematic diagram of the square end face of the crash box.

Fig. 11 is a schematic diagram of an elliptical end face of a crash box.

Fig. 12 is a schematic diagram of the rectangular end face of the crash box.

Fig. 13 is a schematic diagram of the hexagonal end face of the crash box.

Detailed ways

Example 1:

Using the variable thickness rolling technology, the periodical variable thickness strip steel is rolled out with a width of 440mm. The length in one cycle is 200mm, and the thickness gradually transitions from 2mm to 1mm and then to 2mm, and the thickness transition form is the curved transition form shown in Figure 6.

The periodically variable thickness strip is cut into a differential thickness plate blank with a length of 200mm and a width of 440mm. The thickness of the two ends of the differential thickness plate in the length direction is 2mm, and the middle thickness gradually transitions to 1mm, and then transitions to 2mm.

The difference thickness plate blank is rolled and welded into a circular cross-section energy-absorbing box with a diameter of 140mm. The wall thickness at both ends is 2mm, and the middle wall thickness gradually transitions to 1mm. The longitudinal section is shown in Figure 3.

The prepared energy-absorbing box with circular section with variable wall thickness has no induction groove, which simplifies the production process and reduces the cost. At the same time, since the thickness of the middle part is only half of that of the constant-thickness crash box, the weight of the variable-wall-thickness crash-absorbing box is about 1/4 less than that of the constant-thickness crash-absorbing box, realizing lightweight.

The prepared energy-absorbing box with variable wall thickness was fixed between the anti-collision beam and the longitudinal beam of the vehicle body with a connecting plate, and the collision test was carried out. The test results show that when the energy-absorbing box with variable wall thickness is thick at both ends and thin in the middle, it first collapses in the middle thin area, and then expands to the entire energy-absorbing box, finally forming a stable symmetrical telescopic deformation.

Compared with a crash box of the same size and equal wall thickness, the total absorbed energy and the peak value of the collision force are equivalent when the two ends are thick and the middle is thin and the wall thickness is changed, but the energy absorption is much higher.

Example 2:

Using the variable thickness rolling technology, the periodical variable thickness strip steel is rolled out with a width of 360mm. The length in one cycle is 250mm, and the thickness gradually transitions from 1mm to 2mm, and the thickness transition form is the linear transition form shown in Figure 8.

The periodically variable thickness strip steel is cut into a differential thickness plate blank with a length of 250 mm and a width of 360 mm. The thickness of one end of the length direction of the blank is 1 mm, the thickness of the other end is 2 mm, and the thickness between the two ends is linearly transitioned.

Cold-bending and welding the difference-thickness plate blank into a square-section energy-absorbing box with a side length of 90 mm. The thickness of one end of the energy-absorbing box is 1 mm, and the thickness of the other end is 2 mm. The longitudinal section is shown in Figure 5.

The prepared energy-absorbing box with variable wall thickness and square section has no induction groove, which simplifies the production process and reduces the cost. At the same time, the weight of this energy-absorbing box with variable wall thickness is reduced by about 1/4 compared with that of the original energy-absorbing box with equal thickness, which realizes light weight.

The prepared square-section energy-absorbing box with variable wall thickness was fixed between the anti-collision beam and the longitudinal beam of the vehicle body with a connecting plate, and the crash test was carried out. The test results show that the variable-wall-thickness energy-absorbing box with a uniform linear transition from thin to thick will first be crushed in the thin area, and then spread to the entire energy-absorbing box, finally forming a stable symmetrical telescopic deformation.

Compared with the same size and constant wall thickness crash box, the total absorbed energy and specific energy of the variable wall thickness crash box with uniform transition from thin to thick are both higher, and the peak value of the impact force is reduced.

Claims (4)

1. an automobile-used longitudinally change wall thickness metal energy-absorption box, it is characterized in that the longitudinal direction of described automobile-used longitudinally change wall thickness metal energy-absorption box or be called that the wall thickness on axial direction is at least made up of a thickness transitions district, or be at least made up of an equal thickness district and at least one thickness transitions district, and the thickness in equal thickness district is identical or different, be connected by thickness transitions district between equal thickness district.

2. automobile-used longitudinally change wall thickness metal energy-absorption box according to claim 1, it is characterized in that connecting in energy-absorption box wall thickness the thickness transitions form with the thickness transitions district in the equal thickness district of identical or different thickness is linear, curve, broken line or multistage curve form, and the Varying-thickness junction curve shape of steel plate used is straight line, curve, broken line or multistage curve.

3. according to claim 1ly automobile-usedly longitudinally become wall thickness metal energy-absorption box, it is characterized in that the automobile-used cross-sectional plane longitudinally becoming wall thickness metal energy-absorption box is circular, oval, square, rectangle or polygon.

4. the automobile-used preparation method longitudinally becoming wall thickness metal energy-absorption box as claimed in claim 1, is characterized in that described preparation method carries out according to the following steps:

(1) utilize Varying-thickness rolling technique that equal thickness steel plate rolling is become longitudinal variable-thickness plate, wherein, the mode of the longitudinal variable-thickness of longitudinal variable-thickness plate is identical with the change wall thickness mode required for energy-absorption box;

(2) above-mentioned Varying Thickness Plates is cut off according to the specification required for energy-absorption box, use as energy-absorption box blank;

(3) utilize cold bending mode that above-mentioned energy-absorption box blank is configured as the shape of energy-absorption box;

(4) gap that the energy-absorption box after shaping occurs after shaping is welded, form the energy-absorption box parts closed, thus obtain automobile-used longitudinal change wall thickness metal energy-absorption box.