JP4782395B2 - Front underrun protector - Google Patents

Description

  The present invention relates to a front underrun protector provided at a lower front portion of a vehicle in order to prevent one vehicle from entering under the other vehicle at the time of a collision between vehicles.

  The front underrun protector is installed in the lower front part of heavy-duty vehicles such as trucks. When a collision with a light-weight vehicle such as a passenger car (a rear-end collision, frontal collision, etc.) occurs, It is intended to prevent you from diving down and avoid a major accident. That is, the front underrun protector can be said to be a vehicle dive prevention device at the time of a collision (see Patent Document 1).

  As shown in FIG. 7, the front underrun protector mainly includes an FUP main body 2 arranged to extend in the vehicle width direction at the front lower part of the vehicle, and a mounting bracket 4 attached to the FUP main body 2. The mounting bracket 4 and the support 5 for connecting the vehicle body frame 6 are composed of three types and five parts.

  The FUP body 2 has a substantially rectangular closed cross-sectional shape, and in many cases, both ends in the longitudinal direction are curved toward the vehicle rear side due to restrictions on the vehicle layout. In other words, the FUP main body 2 is formed at the central portion in the longitudinal direction, and is formed continuously from the central portion 3 extending substantially parallel to the vehicle width direction of the vehicle and both longitudinal ends of the central portion 3. And a curved portion 7 that curves backward, so that it does not protrude forward from the bumper of the vehicle.

Special table 2001-515432 gazette

  By the way, as described above, the front underrun protector supports a collision load, and thus is required to have high rigidity. Therefore, as shown in the figure, as one form of simulation at the time of a vehicle collision, a test is performed in which a predetermined load P (for example, 50% of the vehicle weight) is applied to a position inside a predetermined distance (for example, 200 mm) from the outermost side of the vehicle. Is called. For example, in Europe and the like, it is known that the test is performed under the above load condition.

  However, when the FUP body 2 has the curved portion 7 as shown in the figure, the load P is applied to the curved portion 7, so that stress concentrates on the rear surface of the FUP body 2 and deforms (folds). There was a case. More specifically, the rear surface 7a of the curved portion 7 is a vehicle that is caused by the stress concentration caused by the rear surface 7a being bent backward and the curved portion 7 being inclined with respect to the load P. Since the stress generated by the component force F1 (see FIG. 8) inward in the width direction is combined, a large compressive stress is generated, and thereby the FUP body 2 is deformed. Alternatively, when a load P is applied to the FUP main body 2, as shown in FIG. 8, a moment M centering on the mounting portion A between the FUP main body 2 and the mounting bracket 4 is generated, so that stress concentrates on the mounting portion A. Thus, the FUP body 2 may be deformed.

  Here, when the FUP main body 2 is manufactured by bending a pipe, it is considered that wrinkles are generated on the rear surface 7a of the curved portion 7 during manufacturing, and stress is concentrated on the wrinkled portions. In order to prevent the generation of the wrinkles, it is necessary to increase the bending radius of the bending portion 7. However, in this case, the FUP body 2 may protrude forward from the bumper of the vehicle and may not be established in the layout.

  Therefore, as shown in FIG. 9, the FUP main body 2 is divided into a central part 3 and a curved part 7, and only the central part 3 is manufactured from a pipe material. It can be considered to have a divided structure. In this way, wrinkles that cause stress concentration are not formed on the rear surface 7a of the curved portion 7. However, this structure does not solve the fundamental causes of the deformation of the FUP main body 2 such as the stress concentration caused by the curved rear surface 7a and the stress caused by the component force F1 of the load P. Furthermore, in this structure, since the rigidity of the joint portion between the central portion 3 and the curved portion 7 is lower than that of other portions, stress may be concentrated on this portion.

  After all, in order to increase the rigidity of the FUP main body 2 and prevent deformation, it is necessary to increase the plate thickness of the FUP main body 2 or to attach a reinforcing member separately, which increases the weight and manufacturing cost. Was the current situation.

  Accordingly, an object of the present invention is to provide a front underrun protector capable of solving the above-mentioned problems and increasing the rigidity of the FUP main body without increasing the weight and the manufacturing cost.

In order to achieve the above object, the present invention comprises an FUP main body arranged at a lower front portion of a vehicle, a mounting bracket attached to a rear portion of the FUP main body, and a support for connecting the mounting bracket and the vehicle body frame, The FUP body is made of a steel pipe having a rectangular cross section extending in the vehicle width direction. The FUP body is formed at a central portion having an upper surface portion, a front surface portion, a lower surface portion, and a rear surface portion, and at both ends of the central portion and the central portion. A U-shaped curved portion having a front-rear width that is narrower than the front-rear width of the upper and lower surface portions between the front surface portion and the rear surface portion , continuous in the vehicle width direction from the front surface portion of the center portion, and curved toward the vehicle rear side. The mounting bracket attached to the support is formed of a U-shaped steel plate that is fitted to the outside of the FUP main body from the rear side of the vehicle, and its rear surface portion is formed from the rear surface portion of the central portion of the FUP main body. It is formed by linearly extending in the vehicle width direction so as to be located at the rear of the vehicle by a predetermined distance X and straddling the central portion and the curved portion, and the inner end portion in the vehicle width direction is further the rear surface portion, in which vehicle width direction outer end connected to part after the bend.

Moreover, vehicle width direction outer side end portion of the mounting bracket is formed to be curved toward the front of the vehicle and may be connected to vertical made directly with respect to the curved portion.

  According to the present invention, the load applied to the curved portion of the FUP main body can be received by the mounting bracket extending linearly. Therefore, it is possible to avoid “stress concentration due to the curved rear surface”, which is a cause of deformation in the conventional FUP body. Further, since the mounting bracket extends in the vehicle width direction, a component force inward in the vehicle width direction can be received as an in-plane force. Therefore, the rigidity of the FUP main body is remarkably improved as compared with the conventional case. Furthermore, according to the present invention, there is no need to increase the plate thickness of the FUP main body or separately provide a reinforcing member, so that the weight and manufacturing cost are not significantly increased.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  1 is a partially enlarged perspective view of a front underrun protector according to the present embodiment, FIG. 2 is a top view thereof, FIG. 3A is a sectional view taken along line IIIa-IIIa in FIG. 1, and FIG. FIG. 3 is a sectional view taken along line IIIb-IIIb.

  The basic structure of the front underrun protector (hereinafter referred to as FUP) of this embodiment is the same as that shown in FIG. Therefore, here, the configuration of the FUP main body and the mounting bracket, which are characteristic parts of the FUP of the present embodiment, will be described.

  As shown in the figure, the FUP main body 20 of the present embodiment is formed at the center portion in the longitudinal direction, and extends in a straight line substantially parallel to the vehicle width direction of the vehicle, and the length of the center portion 21. And bending portions 22 that are attached to both ends of the direction and are curved toward the vehicle rear side. In FIGS. 1 and 2, only one bending portion 22 is shown.

  In the present embodiment, the central portion 21 is made of a steel pipe having a rectangular cross section extending linearly in the vehicle width direction, and includes an upper surface portion 21a, a front surface portion 21b, a lower surface portion 21c, and a rear surface portion 21d.

The bending portion 22 is made of press-formed article formed by bending a steel plate into a U-shape, Ru includes a top portion 22a, and a front portion 22b, and a lower surface portion 22c. The front and rear widths of the upper surface portion 22a and the lower surface portion 22c of the curved portion 22 are formed narrower than the front and rear widths of the upper and lower surface portions 21a and 21c between the front surface portion 21b and the rear surface portion 21d of the central portion 21. The curved portion 22 is curved so that the front surface portion 22b is continuous in the vehicle width direction from the front surface of the central portion 21 and is located on the vehicle rear side toward the outer side in the vehicle width direction. )) So that it does not protrude forward. An insertion portion 23 that is reduced with respect to other portions is formed at the inner end in the vehicle width direction of the bending portion 22, and the insertion portion 23 can be inserted into the central portion 21. When the insertion portion 23 is inserted into the end portion of the center portion 21 with the front surface portion 22b of the bending portion 22 facing the front side of the vehicle, the upper surface portion 22a, the front surface portion 22b, and the lower surface portion 22c of the bending portion 22 are The upper surface portion 21a, the front surface portion 21b, and the lower surface portion 21c are continuously disposed, and in this state, the central portion 21 and the curved portion 22 are joined by welding or the like.

  The mounting bracket 40 is made of a press-formed product obtained by bending a steel plate into a U-shape, and includes an upper surface portion 40a, a lower surface portion 40c, and a rear surface portion 40d. The mounting bracket 40 extends in a straight line substantially parallel to the vehicle width direction, and is attached to the FUP main body 20 so as to straddle the central portion 21 and the curved portion 22. That is, the inner end portion in the vehicle width direction of the mounting bracket 40 is connected to the rear portion of the central portion 21, and the outer end portion in the vehicle width direction is connected to the rear portion of the curved portion 22. In short, the mounting bracket 40 of the present embodiment is formed longer in the vehicle width direction than the conventional mounting bracket 4 as shown in FIG. 7 and is mounted not only on the central portion 21 but also on the rear portion of the curved portion 22. .

  The mounting bracket 40 is fitted to the outside of the FUP main body 20 from the rear side of the vehicle. The upper surface portion 40a is formed on the upper surface portions 21a and 22a of the central portion 21 and the curved portion 22, and the lower surface portion 40c is formed on the central portion 21 and the curved portion 22. Attached to the lower surface portions 21c and 22c by welding or the like. At this time, the mounting bracket 40 is mounted such that the rear surface portion 40d is positioned on the vehicle rear side by a predetermined distance X (see FIG. 2) from the rear surface portion 21d of the central portion 21. The offset distance X of the mounting bracket 40 is such that the outer end of the mounting bracket 40 in the vehicle width direction applies the load P described in the column “Problems to be solved by the invention” (for example, 200 mm inside from the outermost side of the vehicle). It is set so as to be connected to the bending portion 22 outside the position). In addition, the vehicle width direction outer side edge part of the upper surface part 40a and the lower surface part 40c of the mounting bracket 40 is curved and formed on the vehicle rear side with substantially the same curvature as the curved part 22, and is ahead of the front part 22b of the curved part 22. It is designed not to protrude.

  In the FUP of this embodiment provided with the FUP main body 20 as described above, when a load P is applied to the front surface portion 22b of the bending portion 22, a part of the load P is positioned behind the bending portion 22. 40 is transmitted to the rear surface portion 40d. At this time, since the rear surface portion 40d of the mounting bracket 40 extends linearly, stress concentration on the curved portion as described in the section “Problems to be solved by the invention” does not occur. That is, in the FUP of this embodiment, it is possible to avoid “stress concentration due to the curved rear surface”, which is a cause of deformation in the conventional FUP main body.

  Further, since the mounting bracket 40 extends in the vehicle width direction, the component force F1 (see FIG. 2) inward in the vehicle width direction generated when the curved portion 22 is inclined with respect to the load P is applied to the plate surface. It can be received as an internal force. That is, since the rear surface portion 40d of the mounting bracket 40 extends in parallel with the component force F1, the rigidity with respect to the component force F1 is significantly higher than that of the conventional case.

Furthermore, in the FUP of the present embodiment, the mounting portion A (see FIG. 2) between the FUP main body 20 and the mounting bracket 40 is located on the outer side in the vehicle width direction from the position where the load P is applied. There is no concentration. That is, since there is no discontinuity of rigidity on the rear surface portion of the FUP body 20, stress concentration can be avoided. In the FUP of the present embodiment, it is considered that a load is applied to the mounting portion B (see FIG. 2) between the mounting bracket 40 and the support 5, and this load is applied to the mounting bracket 40 and the central portion 21 of the FUP main body 20. Because it can be received by both, it does not matter.

  For the above reasons, the FUP main body 20 of this embodiment has extremely superior rigidity as compared with the conventional one.

  Further, if the FUP of the present embodiment is used, there is no need to increase the plate thickness of the FUP main body 20 or separately provide a reinforcing member, so that the weight and manufacturing cost are not significantly increased.

  The present invention is not limited to the above embodiment, and various modifications can be considered.

  For example, in the above embodiment, the end portion of the bending portion 22 is inserted into the central portion 21, but the present invention is not limited in this respect, and the bending portion 22 may be fitted to the outside of the central portion 21 and joined. good.

  If it is desired to further increase the rigidity of the FUP main body 20, as shown in FIG. 4, a closing member 25 made of a steel plate having a U-shaped cross section covering the rear portion of the curved portion 22 is provided inside the mounting bracket 40. Also good. The closing member 25 may be curved toward the rear side of the vehicle in the same manner as the curved portion 22, but it is more preferable that the closing member 25 is linearly extended substantially parallel to the vehicle width direction as shown in the figure.

  Next, still another embodiment of the present invention will be described with reference to FIG.

  In this embodiment, the entire FUP main body 20 'is divided into two parts. That is, the FUP main body 20 ′ includes a front member 26 made of a substantially U-shaped steel plate located on the front side of the vehicle and a rear member 27 made of a substantially U-shaped steel plate connected to the rear portion of the front member 26. It consists of.

  The front member 26 is formed at the central portion in the longitudinal direction, and is formed continuously from the central portion 26a extending linearly substantially parallel to the vehicle width direction of the vehicle, and at both longitudinal ends of the central portion 26a. And a bending portion 26b that curves backward.

  The rear member 27 extends linearly substantially parallel to the vehicle width direction over the entire longitudinal direction, and is attached to the rear portion of the central portion 26a of the front member 26 to form a closed cross section. That is, in the present embodiment, the central portion 26a and the rear member 27 of the front member 26 constitute the same member as the central portion 21 of the form shown in FIG.

  Since the structure of the mounting bracket 40 is the same as that shown in FIG. 1, the description thereof is omitted here.

  Also in this embodiment, since the load P applied to the curved portion 26b of the front member 26 can be received by the mounting bracket 40 extending linearly in the vehicle width direction, the same effect as that of the embodiment shown in FIG. Can be obtained. Further, in the embodiment shown in FIG. 1, the FUP main body 20 is composed of three parts of a central portion 21 and two curved portions 22 and 22, whereas in this embodiment, the FUP main body 20 ′ is a front member. 26 and the rear member 27, the number of parts is small, leading to a reduction in manufacturing cost.

  In this embodiment, the rear member 27 may extend to the rear of the curved portion 26b of the front member 26.

  Next, still another embodiment will be described with reference to FIG.

  Since this embodiment is the same as that shown in FIG. 1 except for the structure of the mounting bracket 40 ', only the structure of the mounting bracket 40' will be described here.

  As shown in the figure, the mounting bracket 40 ′ of the present embodiment is formed such that the outer end portion in the vehicle width direction of the rear surface portion 40′d is curved in the direction opposite to the curved portion 22, that is, the vehicle front side, and A flange portion 41 curved at the vehicle rear side with the same curvature as that of the curved portion 22 is provided at the distal end portion. As can be seen from the figure, the flange portion 41 is directly joined to the back surface of the front surface portion 22b of the curved portion 22, and the outer end portion in the vehicle width direction of the rear surface portion 40'd (the portion continuing to the flange 41) is It is disposed substantially perpendicular to the front surface portion 22b.

  In this form, the rear surface portion 40 ′ d of the mounting bracket 40 ′ can receive the entire load P applied to the curved portion 22 as an in-plane force. That is, since the bending portion 22 is inclined with respect to the load P, the force F input to the rear surface portion 40′d of the mounting bracket 40 ′ via the flange 41 is applied to the bending portion 22 as shown in the figure. However, as described above, the outer end portion in the vehicle width direction of the rear surface portion 40′d of the mounting bracket 40 ′ is also attached perpendicularly to the curved portion 22 as described above. All F can be received as an in-plane force. Therefore, the rigidity with respect to the load P is further improved.

It is a partial expansion perspective view of the front underrun protector concerning one embodiment of the present invention. It is a partial expanded top view of the front underrun protector concerning one embodiment of the present invention. (A) is the IIIa-IIIa sectional view taken on the line of FIG. 1, (b) is the IIIb-IIIb sectional view taken on the line of FIG. It is a partial expanded top view of the front underrun protector concerning other embodiments of the present invention. It is a partial expansion perspective view of the front underrun protector concerning other embodiments of the present invention. It is a partial expanded top view of the front underrun protector concerning other embodiments of the present invention. It is a perspective view of the conventional front underrun protector. It is a figure for demonstrating the component force and moment which generate | occur | produce when a load is applied to a FUP main body. It is a partial expansion perspective view of the conventional front underrun protector.

Explanation of symbols

5 Support 20 FUP body 21 Center 22 Curvature 40 Mounting bracket

Claims (2)

A FUP main body arranged at the lower front of the vehicle, a mounting bracket attached to the rear of the FUP main body, and a support for connecting the mounting bracket and the vehicle body frame;
The FUP body is made of a steel pipe having a rectangular cross section extending in the vehicle width direction. The FUP body is formed at a central portion having an upper surface portion, a front surface portion, a lower surface portion, and a rear surface portion, and at both ends of the central portion and the central portion. A U-shaped curved portion having a front-rear width that is narrower than the front-rear width of the upper and lower surface portions between the front surface portion and the rear surface portion, continuous in the vehicle width direction from the front surface portion of the center portion, and curved toward the vehicle rear side. Prepared,
The mounting bracket attached to the support is formed of a U-shaped steel plate that is fitted to the outside of the FUP main body from the rear side of the vehicle, and the rear surface portion is a predetermined distance X from the rear surface portion of the central portion of the FUP main body. It is formed by linearly extending in the vehicle width direction so as to be located at the rear of the vehicle and straddling the central portion and the curved portion, and the inner end in the vehicle width direction is on the rear surface portion of the central portion, A front underrun protector characterized in that an outer end portion in the vehicle width direction is connected to a rear portion of the curved portion. The front underrun protector according to claim 1 , wherein an outer end portion in the vehicle width direction of the mounting bracket is formed to be bent toward the front side of the vehicle and connected to be perpendicular to the curved portion .

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