JP2015108586A - Method for evaluating front face collision performance of front side member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for evaluating the front face collision performance of a front side member capable of reproducing axial compression flexure deformation like a case where a full vehicle is used by a front face collision test using a partial model.SOLUTION: A method for evaluating front face collision performance evaluates a front side member having a bumper beam 2 and left and right side members 1. An inertia mass 4 is rotatably supported by a fixed shaft 3 installed at a position away from the extension line of the side member 1. Impact is applied by an impact head 8 onto the forward end of the side member 1 under a state where the inertia mass 4 being an evaluation object is fixed at the rear end of the side member 1. Thus, axial compression and flexure deformation can be continuously generated in the side member 1.

Description

  The present invention relates to a method for evaluating a frontal collision performance of a front side member using a partial model, which is performed in a development and design stage of an automobile.

  Evaluation of the collision performance of the car body is inevitable at the stage of development and design of automobiles, and automobile manufacturers make prototype vehicles (full vehicles) and conduct performance evaluations. However, since the prototype vehicle is expensive, it is not easy to carry out the evaluation test, and the evaluation opportunities are limited. In addition, since it takes a long time to perform the test, when a problem occurs, it often leads to a delay in the development process. For this reason, it is not easy to mount new materials and new structures on prototype vehicles. Even if it is mounted, many materials and structures cannot be evaluated within a limited number.

  In addition, it was difficult for non-automobile manufacturers to evaluate the collision performance of the car body from the cost-effectiveness and equipment aspects, and it was almost impossible for steel makers and parts manufacturers to evaluate the collision performance of their products. .

  Accordingly, the present inventors have developed a technique for evaluating collision performance using a partial model obtained by extracting a structural member having a large contribution rate of collision energy absorption, and have already obtained a patent (Patent Document 1). The technique of this patent document 1 is particularly suitable for collision performance evaluation such as a center pillar that bends and deforms at the time of a side collision, and can perform accurate performance evaluation using a partial model without creating a full vehicle. Has a large practical effect.

  However, the front side member of an automobile has a complicated deformation behavior in which the evaluation target part moves and collides at the time of a frontal collision and becomes a bending deformation after axial compression. There remains a problem that it is difficult to reproduce the same deformation as when the front wall collides with a rigid wall or an aluminum honeycomb barrier.

Japanese Patent No. 4902027

  Therefore, the object of the present invention is to solve the above-mentioned conventional problems and to reproduce the axial compression-bending deformation similar to the frontal collision test using the full vehicle by the frontal collision test using the partial model. It is to provide a method for evaluating the frontal collision performance of members.

  The present invention made to solve the above problems is a method for evaluating the frontal collision performance of a front side member including a bumper beam and left and right side members, and is installed at a position deviated from the extension line of the side member. The inertial mass is rotatably supported on the fixed shaft, and the inertial mass is fixed to the rear end of the side member to be evaluated, and an impact is applied to the front end of the side member. Is generated continuously.

  As in claim 2, the fixed shaft is preferably a vertical shaft located inside the extension line of the side member. Further, as in claim 3, it is preferable that the maximum backward rotation angle of the inertial mass is regulated by a stopper provided at a rear position of the fixed shaft. Further, as in claim 4, it is preferable that a wire is stretched between the left and right side members to prevent outward deformation and to control the vertical behavior. Further, as in claim 5, it is preferable that the rear end of the side member not to be evaluated is completely fixed.

  According to the front side member frontal collision performance evaluation method of the present invention, first, the side member is impacted to cause axial crushing, and the inertial mass fixed to the rear end of the side member is rotated, followed by axial crushing. The side member can be bent and deformed. By adjusting the size of the inertial mass and the position of the fixed shaft, it is possible to reproduce the axial compression-bending deformation similar to the frontal collision test using the full vehicle. Therefore, according to the present invention, it is possible to perform the same performance evaluation as the frontal collision test using the full vehicle by the frontal collision test using the partial model.

  According to the invention of claim 2, since the rotational direction of the inertial mass fixed to the rear end of the side member is specified, it is possible to reproduce the axial compression-bending deformation similar to the frontal collision test using the full vehicle. .

  According to the invention of claim 3, excessive deformation of the side member can be suppressed by restricting the maximum rearward rotation angle of the inertial mass.

  According to the fourth aspect of the present invention, the influence of the engine on the deformation behavior of the front side member can be simulated by stretching the wire in the middle of the left and right side members.

  According to the invention of claim 5, rattling can be eliminated by completely fixing the rear end of the side member not to be evaluated, and the impact force can be concentrated on the side member to be evaluated.

It is a top view which shows a deformation | transformation of the front side member at the time of a front collision. It is a top view which shows embodiment of this invention. It is a front view which shows embodiment of this invention. It is a perspective view which shows embodiment of this invention. It is a comparison figure of the deformation mode of this invention and a full vehicle test. It is a comparison figure of the deformation mode of this invention and a full vehicle test. It is a comparison figure of the deformation mode of this invention and a full vehicle test. It is explanatory drawing of the target mark in an Example. It is a graph which shows the relationship between a displacement amount and a load. It is a graph which shows the relationship between displacement amount and integrated energy.

Embodiments of the present invention will be described below.
FIG. 1 is a plan view showing the deformation of the front side member at the time of a frontal collision. The front side member includes left and right side members 1 and a bumper beam 2. When a frontal collision test using a full vehicle is performed, as shown in FIG. 1, first, axial crushing occurs in the side member 1 on the impacted side, and subsequently bending deformation due to compression occurs. Therefore, when a frontal collision test using a partial model is performed, it is possible to evaluate the frontal collision performance of the front side member by generating the same deformation behavior. As shown in FIG. 1, the rear part of the side member 1 is a part having high strength and is difficult to deform. Therefore, the side member 1 excluding the rear part is used as a partial model in the test.

  2 to 4 are explanatory diagrams of the frontal collision test method of the present invention. In the present invention, the fixed shaft 3 is vertically installed at a position that is inward of the extension line of the side member 1 on the side that is the object of evaluation and to which the impact is applied, and the inertial mass 4 is pivoted on the fixed shaft 3. Let me support you. In this embodiment, the inertial mass 4 has a structure in which a bearing portion 6 having a U-shaped cross section is formed at one end of a flat plate 5 and a weight 7 is fixed to the other end of the flat plate 5. The inertial mass 4 is pivotally supported through the bearing 6 through the fixed shaft 3, and the rear end of the side member 1 is fixed to the front surface of the inertial mass 4.

  The main role of the inertial mass 4 is to cause the side member 1 to continuously produce axial compression in response to impact and bending deformation within a short time. For this purpose, a preliminary test is performed to adjust the mass of the inertial mass 4 and the position of the fixed shaft 3. The mass of the inertial mass 4 may be adjusted according to the vehicle model to be evaluated and the material / structure of the front side member, and is about 100 to 400 kg. In this embodiment, it is 200 kg.

  Reference numeral 8 denotes an impact head for applying an impact to the front end of the side member 1 to be evaluated, and has a mass of 300 to 400 kg. The impact head 8 is driven at a desired collision speed by an appropriate actuator such as a hydraulic cylinder. The inertia mass 4 rotates around the fixed shaft 3 by this impact, but a stopper 9 is provided at the rear position of the fixed shaft 3 to regulate the maximum rearward rotation angle of the inertia mass 4. In this embodiment, the maximum rotation angle is set to 45 °, but can be appropriately changed within a range of about 30 ° to 60 °.

  In the present embodiment, the rear end of the side member 1 on the side not to be evaluated is completely fixed by the plate 10. Thereby, the rattling of the front side member is eliminated, and the impact of the impact head 8 can be concentrated on the side member 1 to be evaluated.

  In this embodiment, a partial model in which a radiator support 11 is attached between the left and right side members 1 and 1 is used. However, a partial model in which the radiator support 11 is omitted can be used.

  Further, in the present embodiment, the wire 12 is stretched at an intermediate position between the left and right side members 1 and 1 to prevent the side member 1 from being deformed to the outside. Further, a wire 12 is stretched between the left and right side members 1 (one side member to be evaluated) to control the vertical behavior. This simulates the effect of the engine mount mounted on the front side member in the actual vehicle on the deformation of the front side member, and is preferably used with tension applied to the wire 12. The position of the wire 12 and the magnitude of the tension are adjusted according to the actual vehicle.

  As described above, the front side member is set in the test apparatus, and the impact head 8 is caused to collide with the front end of the side member 1 to be evaluated. As a result, an impact load in the axial direction is applied to the side member 1, but since the inertial mass 4 is fixed to the rear end of the side member 1, the inertial mass 4 is “compressed” by the impact load at the moment of impact. 1 acts on the side member 1 first to cause the axial compression and buckling shown in FIG.

  During this axial compression, the inertial mass 4 starts to rotate backward about the fixed shaft 3. The angular acceleration is determined by the impact load and the mass of the inertial mass 4. By this rotation, the rear end of the side member 1 is inclined with respect to the compression direction, and changes to a “receiving surface that is not perpendicular to the compression direction”. Accordingly, the rear end of the side member 1 is bent and deformed, and stops at a position where the inertial mass 4 hits the stopper 9. Thereby, the same compression bending as that of the full vehicle shown in FIG. 1 can be reproduced.

  As described above, in order to reproduce the deformation behavior of the structural member at the time of the collision, the “receiving surface perpendicular to the compression direction” for axially crushing the side member 1 and the “compression” for causing the bending deformation. It is necessary to have a receiving surface that is not perpendicular to the direction, and the change must occur continuously within a very short time. Although it is difficult to perform this change using another power, the present invention succeeded in establishing this change in a short time by using the inertial mass 4.

  Therefore, according to the present invention, it is possible to evaluate the frontal collision performance of the front side member without performing an expensive full vehicle test, and it is possible for steel makers and parts manufacturers to evaluate the collision performance of their products. It became.

  5, 6, and 7, the deformation mode is illustrated in comparison with the case where the collision test is performed using the above-described test apparatus according to the embodiment of the present invention and the case where the full vehicle test is performed. In each figure, the upper row shows the present invention, and the lower row shows the full vehicle test. In addition, the situation of arrow A is also shown.

  As shown in FIG. 5, immediately after the collision, the front part of the E / G mount of the side member 1 is buckled, and subsequently the rear part of the E / G mount is bent as shown in FIG. 6, and finally the E / G mount as shown in FIG. G mount is lifted. Although these deformations progress about 0 to 400 mm, it was confirmed that the deformation of the side member 1 was almost the same as that in the full vehicle test even by the evaluation method of the present invention.

  Next, as shown in FIG. 8, two target marks T were set on the side member, and how the distance between them changed during the collision test was measured. In addition, a load cell was installed at the rear end of the side member, and the load acting on the “receiving surface perpendicular to the compression direction” of the side member was measured to calculate the integrated energy.

  FIG. 9 is a graph showing the relationship between the amount of deformation between the target marks TT and the load. It was confirmed that the method of the present invention using the partial model can obtain almost the same result as the full vehicle test.

  FIG. 10 is a graph showing the relationship between the amount of deformation between the target marks TT and the accumulated energy (absorbed energy due to deformation). It has been shown that the method of the present invention using the partial model can obtain almost the same result as the full vehicle test.

DESCRIPTION OF SYMBOLS 1 Side member 2 Bumper beam 3 Fixed shaft 4 Inertial mass 5 Flat plate 6 Bearing part 7 Weight 8 Impact head 9 Stopper 10 Plate 11 Radiator support 12 Wire

Claims (5)

A method for evaluating the frontal collision performance of a front side member having a bumper beam and left and right side members,
An inertial mass is pivotally supported on a fixed shaft installed at a position off the extension line of the side member, and the inertial mass is fixed to the rear end of the side member to be evaluated and impacted on the front end of the side member. And a method of evaluating the frontal collision performance of the front side member, wherein the side member is continuously subjected to axial compression and bending deformation.   2. The front side member frontal collision performance evaluation method according to claim 1, wherein the fixed axis is a vertical axis located on the inner side of the extension line of the side member.   The front side member front collision performance evaluation method according to claim 1, wherein a maximum rotation angle of the inertial mass to the rear is regulated by a stopper provided at a rear position of the fixed shaft.   The front side member front impact performance evaluation method according to claim 1, wherein a wire is stretched between intermediate portions of the left and right side members to prevent outward deformation and to control vertical behavior.   2. The front side member frontal collision performance evaluation method according to claim 1, wherein the rear end of the side member on the side not to be evaluated is completely fixed.