JP4333310B2 - Automotive bumper equipment - Google Patents

Description

  The present invention relates to an automobile bumper device that efficiently absorbs impact energy with respect to a frontal collision including an oblique direction and a pole collision.

  A bumper device for an automobile includes a bumper beam (also referred to as a bumper inhose) that extends in the width direction of the vehicle body and is disposed in front (and rearward) of the vehicle, and a side frame that extends in the front-rear direction on both sides of the vehicle body. And a bumper stay that is disposed between the bumper beam and fixes the bumper beam to the side frame.

  The bumper beam is made of an aluminum alloy extruded shape or a pressed steel plate, and its cross-sectional shape is often U-shaped, B-shaped, Sun-shaped or eye-shaped. There has been proposed a hollow main body portion fixed to the rear wall portion of the bumper beam and an insertion portion extending integrally from the main body portion and inserted into a side frame (Japanese Patent Application Laid-Open No. 2002-234409). See the official gazette).

Japanese Patent Laid-Open No. 2002-234409 proposes welding a bumper beam and a bumper stay, and bolting the side frame and the bumper beam via a bumper stay flange.
Separately, Japanese Patent Laid-Open No. 7-186849 discloses that a bumper beam is composed of a center beam (center portion) and corner beams (corner portions) on both sides of the bumper beam, and these are connected by welding or the like. Therefore, it is proposed that the corner beam is orthogonal to the load direction with respect to the collision in the oblique direction and efficiently absorbs the impact energy in the oblique direction.

  Japanese Patent Application Laid-Open No. 7-186849 proposes that a corner portion is integrally provided with a stem portion and the stem portion is fixed to a side frame of a vehicle body.

JP 2002-234409 A JP-A-7-186849

In the bumper device of the conventional example, a collision from an oblique direction of the automobile is crushed from the end portion of the bumper beam, so that the initial load is low and the energy loss is large.
This state is indicated by a dotted line in FIG. 6. The dotted line in FIG. 6 shows the energy absorption amount of the 30 degree (angle) barrier load, but the initial load with respect to the stroke is small and the energy absorption efficiency is poor.

  In the conventional bumper device, a large moment is applied to the bumper beam terminal with respect to the frontal collision of the automobile or the pole collision at the center, and the welded portion is cracked, thereby reducing the energy absorption efficiency.

  Therefore, this invention makes it the subject which should be solved to eliminate the malfunction of the prior art mentioned above.

In order to solve the above-described problems, the present invention causes the end portion of the bumper beam to bite into the bumper stay, the inner rib of the bumper stay is made into a curved shape in advance, and the rear mounting wall portion of the bumper stay is welded to the side frame. Use technical means.
Preferably, the bumper beam, the bumper stay, and the side frame are formed from an aluminum alloy material.

  The use of this basic technical means prevents the welded part (bumper stay and bumper beam and between the bumper stay and the side frame) at the time of collision from cracking, and makes the ribs curved instead of buckling. It enables the action of maintaining the load by bending deformation. Thereby, the energy absorption curve shown by the straight line in FIG. 6 is obtained, the load at the initial stage of the collision can be increased, and the energy absorption amount can be increased.

  According to the present invention, the front mounting wall portion includes a bumper beam extending in the vehicle width direction of the automobile, and a bumper stay disposed between the side frame of the vehicle body and each end portion of the bumper beam. A curved surface having a rear mounting wall, an inner rib and an outer rib that connect the two mounting walls, and a reinforcing portion that is integrally coupled to the rear mounting wall and the inner rib, and the inner rib bulges outward. The outer rib and the rear mounting wall portion are coupled via the curved surface portion, and each end portion of the bumper beam is inserted between the mounting piece of the front mounting wall portion and the mounting piece of the reinforcing portion and welded. An automobile bumper device is provided in which a flange at a front end portion of a side frame is fitted to a curled portion of a rear mounting wall portion of a bumper stay.

  The end of the bumper beam is inserted between the opposing mounting pieces of the bumper stay and welded to the mounting pieces, but this configuration reduces stress concentration on the welded portion, particularly with respect to a collision in an oblique direction. Can be prevented from cracking.

  Furthermore, in the event of an oblique collision, the impact energy is efficiently absorbed by the collapse of the cross-sectional shape of the mounting piece and the rib between the mounting pieces.

A large moment is applied to both ends of the bumper beam during a collision with the flat barrier, that is, in front of the bumper beam, but in addition to fitting the flange of the side frame to the curl of the bumper stay and preferably welding between the side frame and the bumper stay. The bumper beam's holding onto the bumper stay can take this moment firmly.
In particular, the fitting of the side frame flange and the bumper stay into the curled portion, that is, the fitting of the side frame flange and the bumper stay into the curled portion can reduce welding or welded portions.

  In the event of a 30-degree (angle) barrier collision, a force is applied in the lateral (vehicle width) direction of the vehicle, but this force is firmly received by the fitting structure of the side frame flange to the bumper stay curl, so welding is not required. Or it can be set as the structure which has the minimum welding part.

  Please refer to FIG. A bumper apparatus 1 for an automobile according to a preferred embodiment includes a bumper beam (also referred to as a bumper inhose) 2 made of an aluminum alloy extruded shape, and a bumper stay 3 made of an aluminum alloy extruded shape welded to both ends thereof. The bumper stay 3 is welded to the side frame 4 on the vehicle body side made of an extruded shape of an aluminum alloy.

  As shown in FIG. 2, the bumper beam 2 is composed of an aluminum alloy extruded shape having a cross-sectional shape. However, the cross-sectional shape is not limited to the illustrated example, and the cross-sectional shape is a square shape or a square shape. The shape may be sufficient, and the press work product of a steel plate may be sufficient. Reference numeral 17 denotes a bumper cover.

  As shown in FIG. 3, the bumper stay 3 has a front mounting wall portion 7 along the shape of the front wall portion 6 of the bumper beam 2, and a rear mounting along the end surface of the side frame 4, facing the front mounting wall portion 7. The wall 8, the inner and outer ribs 9, 10 that connect the both mounting walls 7, 8, the inner rib 9, and the rear mounting wall 8 are integrally coupled and face the mounting piece 11 of the front mounting wall 7. And a hollow reinforcing portion 13 having a mounting piece 12. The attachment piece 12 may extend laterally inward from the inner rib 9, and the attachment piece 12 and the rear attachment wall portion 8 may be coupled by the reinforcing portion 13.

  A groove portion, that is, a curled portion 14 having a substantially U-shaped cross section is provided at both ends of the rear mounting wall portion 8, and the side frame 4 is moved rearward with the flange portion 15 of the side frame 4 fitted in the curled portion 14. Weld to the mounting wall 8.

  The inner rib 9 has a curved surface that bulges outward between the attachment piece 12 of the reinforcing portion 13 and the attachment piece 11 of the front attachment wall portion 7, and a joint portion 16 with the rear attachment wall portion 8 of the outer rib 10. Is positioned on the inner side than the other parts, and the curved surface portion is provided.

  The end portion of the bumper beam 2 is inserted between the mounting pieces 11 and 12, and the end portion of the bumper beam 2 is welded to the bumper stay 3. As a result, the bumper stay 3 is composed of an extension portion in the longitudinal direction of the bumper beam 2 and a portion located between the bumper beam 2 and the side frame 4, and the end surface of the bumper beam 2 is opposed to the inner rib 9.

FIG. 7 shows the flange portion 15 of the side frame 4. Cut in the longitudinal direction at the corners of the side frame 4 made of an extruded shape of aluminum alloy (in the illustrated example, the shape of the cross-sectional mouth), cut the upper and lower walls, and bend the opposing side wall at a substantially right angle A flange portion 15 is formed on the frame 4.
The flange portion 15 is held in the curled portion 14 of the rear wall portion 8 of the bumper stay 3, and an external force acting in the vehicle width direction is received by the holding portion. As a result, this external force can be absorbed efficiently.
A curled portion may be provided on the flange portion of the side frame, and the side edge of the rear mounting wall portion may be fitted to the curled portion.

  Even if the welding between the rear wall portion 8 of the bumper stay 3 and the upper and lower wall portions of the side frame 4 is temporary welding, the external force is supported by the holding of the curled portion 14 and the flange portion. There is no change in the absorbed energy curve.

A bumper beam 2 and a bumper stay 3 formed from an extruded shape of an aluminum alloy are fixed to a side frame made of an extruded shape of an aluminum alloy as shown in FIGS. 1 and 3, and a flat barrier test indicated by A in FIG. The 30 degree (angle) barrier test shown in B was performed.
In the flat barrier test A, a large moment was applied to the end portion of the bumper beam 2, but no cracks were observed in the welded portion. This contributes to the fact that the end portion of the bumper beam 2 is inserted between the pair of attachment pieces 11 and 12 to alleviate stress concentration and suppress cracking of the welded portion.

FIG. 5 shows the 30-degree barrier test B, and FIG. 6 shows the relationship between the resulting stroke and load.
In FIG. 5, a dotted line shows the shape of the bumper stay 3 of the bumper device before the 30-degree barrier test, and a solid line shows the shape of the bumper stay 3 deformed by the test. When the 30-degree barrier surface pushes the front mounting wall portion 7 of the bumper stay 3, the inner rib 9 first bulges while deforming outward by the arrow C, and the end portion of the bumper beam 2 is compressed and deformed, so that the dotted line shape changes to a solid line shape. Deform. Next, the coupling portion 16 of the outer rib 10 is deformed in the direction of the arrow D, the ribs 9 and 10 are deformed so that the front mounting wall portion 7 moves rearward.

  The dimension between the mounting pieces 11 and 12 of the bumper beam 2 decreases while compressing the end portion of the bumper beam 2. Such plastic deformation of the end portion of the bumper beam 2 and the ribs 9 and 10 increases the load at the beginning of the collision, and shows an impact energy absorption amount shown by a solid line in FIG. As is clear from the figure, the load value close to the upper limit load corresponding to the proof stress of the member is shown from the early stage of the stroke, and the amount of energy absorption is increased compared to the conventional example. Stroke can be reduced.

It is a top view of the bumper device for cars of an example of the present invention. It is sectional drawing seen from the arrow II-II of FIG. It is a perspective view which shows a bumper stay. It is sectional drawing seen from the arrow IV-IV of FIG. It is a top view which shows the deformation | transformation of the bumper stay by a 30 degree | times barrier test. It is a graph which shows the relationship between the stroke and load by a 30 degree | times barrier test. It is a fragmentary perspective view which shows the flange part of a side frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automobile bumper apparatus 2 Bumper beam 3 Bumper stay 4 Side frame 7, 8 Mounting wall part 9,10 Rib 11,12 Mounting piece 13 Reinforcement part 14 Curl part 15 Flange part

Claims (3)

A bumper beam extending in the vehicle width direction of the automobile, and a bumper stay disposed between the side frame of the vehicle body and each end portion of the bumper beam,
The front mounting wall and the rear mounting wall that the bumper stays face and separate from each other, the inner rib and the outer rib that connect the both mounting walls, and the reinforcing portion that is integrally coupled to the rear mounting wall and the inner rib. The inner rib has a curved surface that bulges outward, and the outer rib and the rear mounting wall portion are joined via the curved surface portion;
Each end of the bumper beam is inserted and welded between the mounting piece on the front mounting wall and the mounting piece on the reinforcing part, and the flange on the front end of the side frame is fitted to the curl on the rear mounting wall of the bumper stay A bumper device for an automobile characterized by the above.   The bumper device for an automobile according to claim 1, wherein the mounting piece of the front mounting wall portion has a shape along the extension line of the front wall of the bumper beam, and the rear mounting wall portion has a shape along the end surface of the side frame. Bumper beam, an automotive bumper system according to claim 1 or 2 bumper stay and the side frame is made of aluminum alloy material.

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