JP5965282B2 - Exterior beam for vehicles - Google Patents

Description

  The present invention relates to a vehicular exterior beam disposed on a vehicle in order to prevent a dive when the vehicles collide with each other.

  In general, a vehicle with a high vehicle height, such as a truck, has a front under-run protector (FUP) or a RUP (RUP) in a lower position in the front and rear of the vehicle in order to prevent a car from falling when a vehicle with a low vehicle height collides. A vehicular exterior beam called “Rear Under-run Protector” is provided. These exterior beams for vehicles are formed in a substantially rectangular tube shape, and various measures have been taken, such as increasing the plate thickness or providing reinforcing members in order to prevent deformation at the time of collision. Yes. However, when the plate thickness is increased, an increase in weight and an increase in manufacturing cost are problematic.

Therefore, in Patent Document 1 and Patent Document 2, in order to improve load bearing performance (strength) without increasing the thickness of the exterior beam (underrun protector) or providing a reinforcing member, It has been proposed that a substantially central portion in the vertical direction bends or bends so that a substantially central portion in the vertical direction protrudes rearward in the vehicle traveling direction from both ends in the vertical direction at the back surface portion of the exterior beam located on the rear side in the traveling direction. And as a material of these exterior beams, a high-tensile material (high tensile steel) is applied.
By making the shape of the back part a convex shape that protrudes backward, the rigidity of the center part of the back face can be increased, so that the compressive stress of the back face that occurs with respect to the load received from the front face is It is said that it can be prevented from being concentrated locally in the central part.

  Further, in Patent Document 3, the thickness of the front plate of the exterior beam (impact buffer absorbing member) is made larger than the thickness of the back plate, and in the cross-sectional shape, on both sides of the intermediate connecting plate orthogonal to the front plate, The two connecting plates are symmetrically arranged so as to expand toward the front plate, and both end portions in the width direction of the front plate and the back plate are extended outward from the connecting plates on both sides. Thus, it is disclosed that the impact energy absorbability can be effectively improved.

JP 2004-299556 A JP 2005-225327 A JP 2012-081861 A

  However, demands for reducing the weight of the exterior beam and increasing the load-bearing performance are increasing, and there is a need for further weight reduction and improved load-bearing performance.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an exterior beam for a vehicle capable of reducing weight and improving load bearing performance.

  The vehicle exterior beam of the present invention is a vehicle exterior beam having a rectangular tube-shaped beam body extending in the vehicle width direction at a position below a front portion or a rear portion of the vehicle, and mounting the beam body to the vehicle. The height H0 of the surface is formed to be larger than the height of the front surface located on the opposite side, and at least the upper surface of the beam main body extends from the upper end of the mounting surface toward the upper end of the front of the beam main body. A slope portion extending inwardly so as to gradually reduce the height, and a flat portion extending horizontally from the slope portion to the upper end portion of the front surface, and the slope portion with respect to the width W0 of the upper surface. The ratio W1 / W0 of the width W1 is 0.3 or more and less than 0.7 and the ratio H1 / H0 of the height H1 of the inclined surface portion to the height H0 of the mounting surface is 0.01 or more and less than 0.03, or Ratio W1 / 0 and the ratio H1 / H0 is less than 0.2 to 0.3 is characterized in that it is set to less than 0.02 or more 0.04.

  Further, in the vehicle exterior beam according to the present invention, an inclined surface extending downwardly from the lower end portion of the mounting surface toward the lower end portion of the front surface while the lower surface of the beam body extends toward the inner side of the beam body, and the inclined surface It is good to form with the plane part extended horizontally from a part to the lower end part of the front, and the slope part and plane part of the lower surface are good to be formed symmetrically with the slope part and plane part of the upper surface.

It is conceivable that a load per piece is applied to the upper end of the front of the beam main body at the time of a vehicle collision, but at least the upper surface of the beam main body is formed by a slope portion and a flat portion set in the above range, The buckling strength against the load can be increased.
Further, by setting the shape of the upper surface and the lower surface of the beam body in the above range, the buckling strength against the load can be increased when receiving a load from the front. Therefore, when the cross section is designed with the same strength as the conventional one, the beam body can be reduced in weight. Further, since no additional reinforcement or the like is required, it can be easily mounted on the vehicle.
When a load higher than the design strength (buckling strength) is applied, first, the upper surface and the lower surface of the beam body are deformed so as to bend inwardly of the beam body. Thereby, the impact at the time of a vehicle collision can be absorbed, other parts can be prevented from being deformed, and the vehicle can be surely prevented from entering. In a design out of the above range, the upper and lower surfaces of the beam body may be bent and deformed so as to swell outward in the beam body. In this case, the corner portion between the mounting surface and the slope portion and the inner surface side of the corner portion between the front surface and the flat surface portion become the starting point of deformation and cause wall buckling. Is difficult to obtain.

In the vehicle exterior beam of the present invention, the upper surface and the back surface side of the lower surface of the beam main body may be formed by a plane extending horizontally from the mounting surface to the front surface along the plane portion.
The slopes on the upper and lower surfaces of the beam body are formed thicker than the planar part by forming the back side as a flat surface, so that the rigidity is enhanced and the load applied at the time of a vehicle collision on the slope part is increased. Since it can receive in a dispersed manner, the buckling strength can be increased.

In the vehicle exterior beam of the present invention, a corner portion between the mounting surface and the slope portion and a corner portion between the front surface and the flat portion are provided in an arc shape, and the inner surface side of these corner portions The radius R is preferably set to 3 mm or more and 6 mm or less.
Since the radius on the outer surface side of the corner portion remains constant, the stress concentration at the corner portion is suppressed as the radius R on the inner surface side increases, so that the buckling strength can be increased. When the radius R is less than 3 mm, the required buckling strength (for example, 50 kN or more) cannot be obtained. Further, when the radius R exceeds 6 mm, the buckling strength can be increased, but this is not preferable because the corner portion becomes thick and the weight of the beam body increases.

In the vehicle exterior beam of the present invention, it is preferable that the connection portion between the slope portion and the flat portion is provided in an arc shape.
By forming the connection portion between the slope portion and the flat portion on the upper surface and the lower surface of the beam body in an arc shape, stress concentration in the connection portion is suppressed, and the buckling strength can be increased.

In the vehicular exterior beam of the present invention, the upper surface and the lower surface may be provided with a thin portion at an intermediate portion in the width direction.
By providing a moderately thin portion at the intermediate portion in the width direction of the upper surface and the lower surface, when receiving a load from the front, the upper surface and the lower surface can be triggered to be deformed inward of the beam body.

In the vehicle exterior beam according to the present invention, the beam body may be formed of an extruded material of an aluminum alloy.
The above-mentioned shape can be easily formed by forming the beam body from an aluminum alloy extruded material. Moreover, the said shape is applicable to the extrusion material of cross-sectional shapes, such as a substantially square shape, a substantially day shape, and a substantially square shape.

  According to the present invention, when the beam body is subjected to a load, the upper surface and the lower surface are deformed inwardly of the beam body, so that the buckling strength can be increased, and the cross-section design is made with the same strength as before. In this case, the beam body can be reduced in weight. Therefore, it is possible to reduce the weight of the vehicle exterior beam and improve the load bearing performance.

It is a perspective view which shows the exterior beam for vehicles of 1st Embodiment of this invention. It is sectional drawing of the beam main body of the exterior beam for vehicles shown in FIG. It is a principal part cross-section part of the lower surface part of the beam main body shown in FIG. It is a graph which shows the relationship between the buckling strength of the beam main body just above a stay, and the inner side radius R of a corner part. It is principal part sectional drawing of the beam main body of the exterior beam for vehicles of 2nd Embodiment of this invention. It is a figure explaining the load per piece applied to a beam main part. It is sectional drawing of the beam main body of the exterior beam for vehicles of 3rd Embodiment of this invention. It is sectional drawing of the beam main body of the exterior beam for vehicles of other embodiment of this invention. It is the table | surface which showed the relationship between the ratio W1 / W0 of the width | variety of a beam main body, the ratio H1 / H0 of height, and buckling strength in the area | region for every magnitude | size of buckling strength.

Hereinafter, an embodiment of a vehicle exterior beam according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the exterior beam 100 for a vehicle according to the first embodiment includes a rectangular tube-shaped beam body 10 that extends in the vehicle width direction at a position below a front portion or a rear portion of a vehicle (not shown). The beam body 10 is configured to be attached to a vehicle body frame 20 via a stay 21. Then, as shown by a load F in FIG. 1, when the vehicle collides with the front surface 12 of the beam main body 10 and a load is applied, the vehicle is prevented from entering.

  As shown in FIG. 1, the beam body 10 is formed in a rectangular tube shape by extrusion molding of an aluminum alloy or the like, and is formed to have a length comparable to the width dimension of the vehicle to be attached. As the material of the beam body 10, for example, aluminum of 6000 series alloy or 7000 series alloy can be used.

The height H0 of the mounting surface 11 of the beam body 10 to the vehicle is formed to be larger than the height of the outwardly facing front surface 12 located on the opposite side. Further, the upper surface 13 and the lower surface 14 of the beam body 10 are inclined and extend inward so as to gradually decrease the height of the beam body 10 from the upper and lower ends of the mounting surface 11 toward the upper and lower ends of the front surface 12. A portion 15 and a flat portion 16 extending horizontally from the slope portion 15 to the upper and lower end portions of the front surface 12 are formed. And the connection part 23 between the slope part 15 and the plane part 16 is formed in circular arc shape, as shown in FIG. Further, the ratio W1 / W0 of the width W1 of the inclined surface portion 15 to the width W0 of the upper surface 13 and the lower surface 14 is 0.3 or more and less than 0.7, and the ratio of the height H1 of the inclined surface portion 15 to the height H0 of the mounting surface 11 H1 / H0 is 0.01 or more and less than 0.03, or the ratio W1 / W0 is 0.2 or more and less than 0.3, and the ratio H1 / H0 is 0.02 or more and less than 0.04. Is set.
In addition, the corner portion 17 between the mounting surface 11 and the slope portion 15 and the corner portion 18 between the front surface 12 and the flat portion 16 are provided in an arc shape. The radius R is set to 3 mm or more and 6 mm or less.
Moreover, the horizontal horizontal rib 19 is provided in the intermediate position of the height direction, and the cross section is formed in the shape of a Japanese character.

  The outer dimensions of the beam body 10 are such that the height H0 of the mounting surface 11 is 75 mm to 170 mm, and the widths W0 of the upper surface 13 and the lower surface 14 are 50 mm to 110 mm. The plate thickness of the peripheral wall of the beam body 10 is set such that the plate thickness on the mounting surface 11 side and the front surface 12 side is 4 mm to 9 mm, and the plate thickness of the upper surface 13 side and the lower surface 14 side and the lateral rib 19 is 2 mm to 6 mm. Is set.

  By setting the shape of the beam body 10 in the above range, the exterior beam 100 for a vehicle has a buckling strength against this load when a load is applied from the front surface 12 side like the load F shown in FIG. Can be increased. As shown in FIG. 2, the width W0 of the upper surface 13 and the lower surface 14, which is an important parameter affecting the buckling strength, has a slope portion 15 inclined inward of the beam body 10, and the width thereof. The effective length W2 with respect to W0 (Euler's formula effective length regarding buckling) can be shortened, and the buckling strength with respect to the load F can be increased. Therefore, when the cross section is designed with the same strength as the conventional one, the beam body can be reduced in weight.

Moreover, the connection part 23 of the slope part 15 and the plane part 16 of the upper surface 13 and the lower surface 14 of the beam body 10 is formed in an arc shape as shown in FIG. 3, and stress concentration at the connection part 23 can be alleviated. And the buckling strength at the time of impact can be increased.
Further, since the outer surface side radius of the arc-shaped corner portions 17 and 18 is kept constant, the stress concentration of the corner portions 17 and 18 is suppressed as the inner surface side radius R increases, so that the buckling strength is further increased. Can be increased.
For example, the graph of FIG. 4 shows that the ratio H1 / H0 of the height H1 of the slope 15 to the height H0 of the mounting surface 11 is 0.01, and the ratio of the width W1 of the slope 15 to the width W0 of the upper surface 13 and the lower surface 14. The relationship between the buckling strength of the beam body directly above the stay 21 and the inner radius R of the corner portions 17 and 18 when W1 / W0 is 0.4 is shown, and the necessary buckling strength (for example, about It can be seen that the radius R should be set to 3 mm or more in order to obtain 50 kN).
If the radius R is less than 3 mm, the required buckling strength cannot be obtained. Further, when the radius R exceeds 6 mm, the buckling strength can be increased, but it is not preferable because the corner portions 17 and 18 are thick and the weight of the beam body is increased.
Thus, the buckling strength can be easily adjusted by appropriately setting the radius R of the corner portions 17 and 18.

Further, since the beam body 10 has the slope portion 15 with respect to the direction in which the load F is applied (the width direction of the beam body 10), a load greater than the design strength (buckling strength) is applied to the front surface 12. In this case, first, the upper surface 13 and the lower surface 14 of the beam body 10 are deformed in the inner direction of the beam body 10 from the vicinity of the connection portion 23 between the slope portion 15 and the flat portion 16. Thereby, the impact at the time of the vehicle collision can be absorbed and other parts such as the stay 21 can be prevented from being deformed, so that the vehicle can be surely prevented from entering.
Furthermore, like the beam main body 30 shown in FIG. 5, by providing an appropriate thin portion 31 having a thickness smaller than that of the front surface 12 side and the mounting surface 11 side at the intermediate portion in the width direction of the lower surface 14 (and the upper surface 13), The lower surface 14 (and the upper surface 13) can be used as a trigger to deform the beam body 30 in the inner direction.

Incidentally, as shown in FIG. 6, in the event of a vehicle collision, there may be a case where a load F ′ per piece is applied to the upper end portion of the front surface 12 of the beam body 40, but the beam body 40 shown in FIGS. 6 and 7. If the upper surface 13 is formed of the inclined surface portion 15 and the flat surface portion 16 and the lower surface 14 is formed of the flat surface portion 16 and the inclined surface portion 15 is provided at least on the upper surface 13, the load per piece is particularly reduced. The buckling strength can be increased.
In the beam body 40, as in the beam body 10 of the first embodiment, the ratio W1 / W0 of the width W1 of the inclined surface portion 15 to the width W0 of the upper surface 13 and the lower surface 14 is 0.3 or more and less than 0.7. Thus, the ratio H1 / H0 of the height H1 of the slope 15 to the height H0 of the mounting surface 11 is 0.01 or more and less than 0.03, or the ratio W1 / W0 is 0.2 or more and less than 0.3. Thus, the buckling strength at the time of the vehicle collision can be increased by setting the slope portion 15 and the flat portion 16 so that the ratio H1 / H0 is 0.02 or more and less than 0.04.

Further, like the beam main body 50 shown in FIG. 8, the rear surface 27 side (inner surface) of the upper surface 13 is formed by a plane extending horizontally from the mounting surface 11 to the front surface 12 along the plane portion 16, thereby further increasing the vehicle. It is also possible to increase the buckling strength at the time of collision.
In this case, the inclined surface portion 15 of the upper surface 13 is formed thicker than the flat surface portion 16 by forming the back surface 27 side as a flat surface. Therefore, the rigidity of the slope portion 15 is increased, and the slope portion 15 can receive the load applied at the time of a vehicle collision in a distributed manner.
Although not shown in the drawing, the back surface of the upper surface 13 and the lower surface 14 is also provided in the configuration having the slope portions 15 on both the upper surface 13 and the lower surface 14 as in the beam main body 10 shown in FIG. By forming the side as a plane extending horizontally from the mounting surface 11 to the front surface 12 along the flat portion 16, it is possible to increase the buckling strength at the time of a vehicle collision.
Other configurations are the same as those of the beam body 10 of the first embodiment, and the same reference numerals are given to the common parts and the description thereof is omitted.

Next, examples according to the vehicle exterior beam of the present invention will be described.
In the code | symbol shown in FIG. 2, about the sample (beam main body) of length: 2330mm formed with the frame material of height H0: 120mm, width W0: 75mm, thickness of a surrounding wall: 3.5mm, and length: 3.5mm The relationship between the ratio W1 / W0 of the slope portion width W1 to the lower surface width W0 and the ratio H1 / H0 of the slope portion height H1 to the mounting surface height H0 was produced under various conditions. Then, an exterior beam for a vehicle is assembled using these samples, and as shown in FIG. 1, the load F is applied to the front surface 12 and the load F is applied until the beam body is buckled. It was confirmed. As the material of the frame material, 6000 series aluminum alloy according to JIS standard was used.
The result is shown in FIG. In FIG. 9, the square of each ratio indicates that it is greater than or equal to the numerical value described in the square and less than the numerical value described in the next square. For example, the mass of 0.2 in W1 / W0 is 0.2 or more and less than 0.3.

  Under the conditions in the range indicated by the arrow a in FIG. 9, the upper and lower surfaces were deformed and buckled outside the beam body, and both had a buckling strength of less than 50 kN. Under the conditions in the range indicated by the arrow b, the upper and lower surfaces were deformed inside the beam body, but the buckling strength was less than 50 kN, and no buckling strength of 50 kN or more was obtained. Under the conditions indicated by the arrow c, the upper and lower surfaces were deformed inside the beam body, and a buckling strength of 50 kN or more was obtained. Further, under the conditions in the range indicated by the arrow d, the upper surface and the lower surface were greatly deformed inside the beam body, and the buckling strength was less than 50 kN.

Thus, the conditions of the range indicated by the arrow c, that is, the ratio W1 / W0 is 0.3 or more and 0.7
The ratio H1 / H0 of the height H1 of the slope 15 to the height H0 of the mounting surface 11 is 0.01 or more and less than 0.03, or the ratio W1 / W0 is 0.2 or more and 0.3. When the load is applied from the front surface 12 side by setting the ratio H1 / H0 to be 0.02 or more and less than 0.04, it can be seen that the buckling strength against this load can be increased. .

In addition, this invention is not limited to the thing of the structure of the said embodiment, In a detailed structure, a various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, the case where the present invention is applied to a vehicle exterior beam disposed at the front portion or the rear portion of the vehicle has been described, but this exterior beam is also applied to a side guard or the like provided on the side of the vehicle. can do.
In addition, the beam main body may be made of not only an aluminum alloy but also other materials such as steel.

DESCRIPTION OF SYMBOLS 10 Beam body 11 Mounting surface 12 Front surface 13 Upper surface 14 Lower surface 15 Slope portion 16 Plane portion 17 Corner portion 18 Corner portion 19 Horizontal rib 20 Body frame 21 Stay 23 Connection portion 27 Back surface 30, 40, 50 Beam body 31 Thin portion 100 For vehicle Exterior beam

Claims (7)

  A vehicle exterior beam having a rectangular tube-shaped beam main body extending in the vehicle width direction at a position below a front portion or a rear portion of a vehicle, and a height H0 of an attachment surface of the beam main body to the vehicle is opposite to The beam body is formed to be larger than the height of the front surface, and at least the upper surface of the beam body is arranged so that the height of the beam body gradually decreases from the upper end portion of the mounting surface toward the upper end portion of the front surface. And a ratio W1 / W0 of the width W1 of the slope with respect to the width W0 of the upper surface is 0. .3 or more and less than 0.7 and the ratio H1 / H0 of the slope portion height H1 to the mounting surface height H0 is 0.01 or more and less than 0.03, or the ratio W1 / W0 is 0.2 or more. Less than 0.3 One said ratio H1 / H0 is exterior beam for a vehicle, characterized in that it is set to less than 0.02 or more 0.04.   A lower surface of the beam body extends obliquely from the lower end portion of the mounting surface toward the lower end portion of the front surface and inclines toward the inner side of the beam main body, and extends horizontally from the inclined surface portion to the lower end portion of the front surface. 2. The vehicular exterior beam according to claim 1, wherein the lower surface slope portion and the plane portion are formed symmetrically with the upper surface slope portion and the plane portion.   3. The vehicle exterior beam according to claim 1, wherein a back surface side of the upper surface and the lower surface of the beam body is formed by a plane extending horizontally from the mounting surface to the front surface along the planar portion. .   A corner portion between the mounting surface and the slope portion and a corner portion between the front surface and the flat portion are provided in an arc shape, and a radius R on the inner surface side of these corner portions is 3 mm or more and 6 mm or less. The exterior beam for vehicles as described in any one of Claim 1 to 3 characterized by the above-mentioned.   5. The vehicle according to claim 1, wherein in the exterior beam for a vehicle according to the present invention, the connection portion between the slope portion and the flat portion is provided in an arc shape. Exterior beam.   The vehicular exterior beam according to any one of claims 1 to 5, wherein the upper surface and the lower surface are provided with a thin portion at an intermediate portion in a width direction.   The vehicular exterior beam according to any one of claims 1 to 6, wherein the beam body is formed of an extruded material of an aluminum alloy.

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