JP5041864B2 - Truck underrun protector - Google Patents

Description

  The present invention relates to a structure of an underrun protector attached to the front and rear of a truck body.

  The underrun protector is installed in the vehicle width direction at the front and rear of a large truck. When a collision with a light and medium class vehicle such as a passenger car (collision from the front, rear collision from the rear) occurs, (See Patent Documents 1 to 3).

JP 2000-272444 A JP 2002-362267 A JP 2004-231044 A

In recent years, the standards for impact strength of underrun protectors have been strengthened, while there is a demand to increase the load weight. For this reason, aluminum alloy extruded materials and high-tensile steel are used as materials in order to achieve both high strength and light weight. ing.
The under-run protector 1 illustrated in FIG. 5 is made of an aluminum alloy extruded material, and has a cross-section of a collision side flange 2 and a mounting side flange 3 that are parallel to each other, and a web 4 to 6 that connects them vertically. The mounting side flange 3 is formed with a mounting bolt hole 7 to the vehicle body frame side, and the mounting work hole 8 is formed at a position (front position) opposite to the bolt hole 7 of the collision side flange 2.
The under-run protector 1 is generally provided with a bent portion bent on the vehicle body side on both sides in the vehicle width direction installed on the front side (see FIG. 6), and generally has a linear shape installed on the rear side. In addition, the collision side flange 2 and the attachment side flange 3 are attached to the vehicle body frame on the left and right sides of the straight portion by bolts and nuts in a form that is substantially vertical (see FIG. 1). In many cases, the underrun protector 1 is attached to the vehicle body frame via a mediating part, and FIGS. 6 and 7 illustrate the attachment form. 6 and 7, the intermediate part 10 (in this example, the underrun protector stay 10 </ b> A and the energy absorbing member 10 </ b> B) is installed with the lower surface of the side rail 9 (or the vehicle body outer side surface) as an installation surface, and below the side rail 9. The underrun protector 1 is fastened to the intermediate part 10 (in this example, the end face of the energy absorbing member 10B) with bolts and nuts.

When the truck collides with another vehicle, if the vehicle collides with a position away from the mounting portion (in the example of FIG. 6, the vehicle V collides with the end of the underrun protector 1), the underrun protector 1 This part is bent and deformed as a fulcrum (shown by an ellipse in FIG. 6), which causes a breakage from the mounting work hole 8, preventing sufficient collision energy from being absorbed and preventing the vehicle V from sinking under the truck. There was a problem that I could not.
The present invention has been made in view of this problem, and an object of the present invention is to prevent the breakage from the mounting work hole even when the underrun protector is bent and deformed with the mounting portion as a fulcrum at the time of collision.

The underrun protector according to the present invention is attached to the body frame of a truck with bolts and nuts, and is made of an extruded aluminum alloy member having a hollow section having a collision side flange, an attachment side flange, and a plurality of webs for connecting the flanges. The collision side flange has a thin wall portion and a thick wall portion above and below, a bolt hole is formed in a mounting portion of the mounting side flange with the vehicle body frame, and the thin wall portion is positioned in front of the bolt hole of the collision side flange. There is a mounting work hole corresponding to the bolt hole. Therefore, in the collision side flange, the thickness of the upper and lower portions is set larger than the thickness of the mounting work hole portion.
The underrun protector may be directly attached to a vehicle body frame such as a side rail with bolts and nuts, or may be attached via an intermediate part such as a stay. In the latter case, it is attached with bolts and nuts to intermediate parts (generally extending downward from the body frame) installed on the body frame of the truck.
In the present invention, the front position of the bolt hole means the front side of the vehicle body in the case of the front-side underrun protector, and the rear side of the vehicle body in the case of the rear-side underrun protector.

According to the present invention, since the thickness of the upper and lower portions of the mounting work hole is set large, the tensile stress (tensile force / cross-sectional area) generated around the mounting work hole can be reduced, and breakage from the mounting work hole can be prevented. . By preventing the under-run protector from being broken during bending deformation, it is possible to sufficiently absorb the collision energy and prevent the collision vehicle from getting under the truck. It should be noted that by setting the thickness of the mounting work hole portion of the collision side flange to be relatively small, it is not necessary to increase the overall cross-sectional area of the extruded profile (the weight of the underrun protector).
Further, by reducing the thickness of the mounting work hole portion, the mounting work hole can be easily drilled. For example, in the case of drilling, the machining time can be shortened, and in the case of press drilling, the punching load is reduced and the core may be unnecessary.

  The underrun protector according to the present invention is made of an aluminum alloy extruded profile, and its cross section is made up of a collision side flange, a mounting side flange, upper and lower webs connecting both, and, if necessary, one or more intermediate webs. The substantially rectangular cross section constituted by the collision side flange, the attachment side flange, and the upper and lower webs can be used as a basic shape, and various modifications can be added to this as required. Bolt holes for mounting are formed in the mounting side flange, and mounting work holes are formed in the collision side flange, and the thickness of the upper and lower portions is thicker than the thickness of the mounting work hole portion of the collision side flange. Is formed. As shown in FIG. 6, there are cases where there are bent portions bent mainly on the vehicle body side on both sides in the vehicle width direction (mainly on the front side of the vehicle) and cases where there are no bent portions (mainly on the rear side of the vehicle).

Hereinafter, the underrun protector according to the present invention will be described more specifically with reference to FIGS.
The underrun protector 11 shown in FIG. 1 includes a collision side flange 12 and a mounting side flange 13 that are parallel to each other, and upper and lower webs 14 and 15 that connect the two vertically, and both flanges 12 and 13 and both webs 14 and 15. Thus, a substantially rectangular cross section is formed. The attachment-side flange 13 and the webs 14 and 15 are all uniform in thickness. The central portion in the vertical direction of the collision side flange 12 is a thin portion 12a having a uniform thickness, and the upper and lower portions thereof are a thick portion 12b having a uniform thickness until reaching the webs 14 and 15. The front surface of the collision side flange 12 is flat, and continues from the thin portion 12a to the thick portion 12b via a transition portion whose rear surface side is inclined.

A mounting bolt hole 16 is formed at the center in the vertical direction of the mounting side flange 13, and a thin portion 12 a of the collision side flange 12 is formed at a front position of the bolt hole 16, and a mounting work hole 17 is formed here. . Looking at the cross section of the collision side flange 12, the mounting work hole 17 substantially fills the thin portion 12a in the vertical direction, and the upper and lower portions of the mounting work hole 17 are thick portions 12b having a larger thickness.
The plan view of the under-run protector 11 is the same as that of the under-run protector 1 shown in FIG. 6, and the under-run protector 11 generally extends below a body frame such as a side rail like the under-run protector 1. It is attached to the intermediate part to be placed, and is arranged at a position below the body frame. Referring to FIGS. 1, 6, and 7, the intermediate component 10 is installed with the lower surface (or the vehicle body outer side surface) of the side rail 9 as an installation surface, and extends below the side rail 9. 1 is fastened to the intermediate part 10 (specifically, the end surface flange 10Ba of the energy absorbing member 10B constituting the intermediate part 10) by a bolt 18 and a nut 19.

When the underrun protector 11 shown in FIG. 1 is used for a normal large truck, items to be generally considered in design will be described below. The following items are applicable not only to the underrun protector 11 but also to all underrun protectors according to the present invention. However, the present invention is not limited to the items described below.
(1) Material of aluminum alloy extruded profile The material strength of the aluminum alloy extruded profile used for the underrun protector is desirably 200 to 500 MPa, and if it is less than this, it is necessary to greatly increase the plate thickness in order to reduce deformation at the time of collision. Therefore, the weight cannot be reduced, and if it exceeds this, the extrudability (die life, extrusion speed) is poor and the cost cannot be reduced.
(2) External dimensions Lf, Lw (unit: mm)
Considering a collision with a vehicle such as a passenger car with a low vehicle height, the dimension in the height direction of the cross section, that is, the flange height Lf is required to be 50 mm or more. On the other hand, considering the cooling of the design and the radiator, the upper limit of Lf The value needs to be 300 mm or less.
The cross-sectional dimension in the longitudinal direction of the vehicle body, that is, the web width Lw needs to be 40 mm or more in order to ensure the collision strength. The greater the Lw, the easier it is to ensure the collision strength, but if it is too large, it will be difficult to ensure clearances with the air conditioning parts, engine parts, electronic parts, etc. on the rear side (vehicle body center side) of the underrun protector. 120 mm or less is desirable.

(3) Web wall thickness Tw (unit: mm)
When another vehicle collides with the underrun protector at a position away from the mounting portion with the vehicle body frame (see FIG. 6), the bending deformation amount is smaller as the bending moment (resistance force against bending) is larger. Therefore, when it is not necessary to consider the strength reduction due to buckling, the web thickness Tw (Tw1, Tw2) is reduced to the minimum thickness that can be extruded, and the collision side flange thickness Tf (thickness portion) is reduced. If the weighted average value of the wall thickness Tf1 and the wall thickness Tf2 of the thin wall portion) and the mounting-side flange wall thickness Tf3 are increased to the required bending moment, the lightest cross section can be designed. .
On the other hand, when colliding with the vicinity of the attachment part with the body frame, the larger the web wall thickness Tw (Tw1, Tw2), the larger the deformation load of the underrun protector can be secured. can do. However, if the crushing deformation load is too large, the intermediate part and the side rail are deformed before the under-run protector, so that the damage is large and the repair cost is high. Further, if the web thickness Tw is large, the remaining crushing increases, and the effective stroke for energy absorption becomes small.
Considering the above points, the web wall thickness Tw is generally desirably 0.8 mm or more, and desirably 1/10 or less of the web width Lw. If the web wall thickness Tw is less than 0.8 mm, the extrudability (die life, extrusion speed) is lowered, depending on the size and shape of the cross section and the strength of the aluminum alloy.

(4) Flange thickness Tf (unit: mm)
The thickness of the thick part of the collision side flange is Tf1, the thickness of the attachment side flange is Tf3, the diameter of the attachment work hole is φf, and the number of attachment work holes on one side of the right and left attachment parts is n (see FIG. 1). In this case, when n = 1), the appropriate value of Tf1 is as follows.
0.8 × Tf3 ≦ Tf1 ≦ Tf3 × (Lf / (Lf−n × φf))
When Tf1 is smaller than the above range, the neutral axis of bending moves too much backward (mounting surface side), so the rate of increase of the total plastic moment is small with respect to the increase in plate thickness, and it is difficult to reduce the weight. On the other hand, if it is larger than the above range, the neutral axis of bending moves too far forward (impact surface side), so the rate of increase of the total plastic moment is small with respect to the increase in plate thickness, making it difficult to reduce the weight.
When the thickness of the thin portion of the collision side flange is Tf2, the appropriate value of Tf2 is as follows.
0.7 ≦ Tf2 ≦ 0.95 × Tf3
When Tf2 is smaller than the above range, the extrudability is deteriorated, and when Tf2 is larger than the above range, the effect of reducing the thickness of the mounting work hole portion (thin wall portion) (increasing the other wall thickness) cannot be obtained.
In addition, the vertical width of the thin portion is formed to be slightly larger than the diameter φf of the mounting work hole in consideration of processing variation in drilling.

2 to 4 show other cross-sectional forms of the underrun protector according to the present invention.
The under-run protector shown in FIGS. 2 (a) and 2 (b) has a substantially rectangular cross section and a substantially cross-sectional cross section, respectively, and the size of the flange height Lf (see FIG. 1) together with the substantially mouth-shaped cross section shown in FIG. Is appropriately selected.
The underrun protector 21 shown in FIG. 2 (a) includes a collision side flange 22 and a mounting side flange 23 that are parallel to each other, upper and lower webs 24, 25 that vertically connect both, and a web 26 in the center in the vertical direction. The flanges 22 and 23 and the upper and lower webs 24 and 25 form a substantially rectangular cross section. The attachment side flange 23 and the webs 24 to 26 are all uniform in thickness.
When the cross section is divided into approximately two equal parts in the vertical direction to form the upper part and the lower part, respectively, the vertical central part of the collision-side flange 22 is a uniform thin part 22a in each of the upper part and the lower part. The upper and lower portions are the thick portions 22b having a uniform thickness until reaching the webs 24, 26 or the webs 26, 25. The front surface of the collision side flange 22 is flat, and continues from the thin portion 22a to the thick portion 22b via a transition portion having an inclined rear surface side.

In each of the upper part and the lower part of the cross section, a mounting bolt hole 16 is formed in the central part in the vertical direction of the mounting side flange 23, and a thin part 22a of the collision side flange 22 is located in front of the bolt hole 16, here. The attachment work hole 17 is formed so as to substantially fill the cross section of the thin portion 22a, and the upper and lower portions of the attachment work hole 17 are thick portions 22b having a larger thickness.
The underrun protector 21 is fastened to an intermediate member 10 installed on a body frame such as a side rail in the same form as the underrun protector 11.

The under-run protector 31 shown in FIG. 2B includes a collision side flange 32 and a mounting side flange 33 that are parallel to each other, upper and lower webs 34 and 35 that vertically connect both, and both flanges 32 and 33 in the vertical direction. It consists of webs 36 and 37 arranged at positions equally divided into three, and both flanges 32 and 33 and upper and lower webs 34 and 35 form a substantially rectangular cross section. The attachment-side flange 33 and the webs 34 to 37 are all uniform in thickness.
When the cross section is divided into approximately three equal parts in the vertical direction to form an upper part, an intermediate part, and a lower part, respectively, the vertical central part of the collision side flange 32 is formed into a thin part 32a having a uniform thickness in the upper part and the lower part. The upper and lower portions are formed as thick portions 22b having a uniform thickness until reaching the webs 34, 36 or the webs 37, 35. Further, the collision side flange 32 has a uniform thickness at the intermediate portion, and the thickness thereof is intermediate between the thin portion 22a and the thick portion 22b. The front surface of the collision side flange 32 is flat, and continues from the thin portion 32a to the thick portion 32b via a transition portion having an inclined rear surface side.

In each of the upper part and the lower part of the cross section, a mounting bolt hole 16 is formed at the center in the vertical direction of the mounting side flange 33, and a thin part 32a of the collision side flange 32 is located in front of the bolt hole 16, and here The attachment work hole 17 is formed so as to substantially fill the thin portion 32a, and the upper and lower portions of the attachment work hole 17 are thick portions 32b having a larger thickness.
The underrun protector 31 is fastened to an intermediate member 10 installed on a body frame such as a side rail in the same form as the underrun protector 11.

The underrun protector 41 shown in FIG. 3 (a) includes a collision side flange 42 and a mounting side flange 43 that are parallel to each other, upper and lower webs 44 and 45 that vertically connect both, and a web 46 in the center in the vertical direction. The flanges 42 and 43 and the upper and lower webs 44 and 45 form a substantially rectangular cross section (a general cross section as a whole when the web 46 is inserted). The mounting side flange 43 and the webs 44 to 46 are all uniform in thickness.
This underrun protector 41 is different from the underrun protector 21 shown in FIG. 2A in that the collision side flange 42 and the attachment side flange 43 are vertically extended from the webs 44 and 45. This is basically the same as the underrun protector 21.

In FIG. 3 (a), 42a is a thin portion of the collision side flange 42, 42b is a thick portion, and the thickness of the portion extending above the web 44 and below the web 45 is the same as that of the thick portion 42b. Is set to Further, 16 is a bolt hole, and 17 is a mounting work hole.
The under-run protector 41 has the collision-side flange 42 and the attachment-side flange 43 extended vertically from the webs 44 and 45, so that buckling deformation at the time of collision is suppressed and a sufficient energy absorption amount can be secured. . This extension can be performed on both or either of the collision side flange 42 and the attachment side flange 43, either on the upper side or on the lower side, and has a corresponding effect.

The under-run protector 51 shown in FIG. 3B includes a collision side flange 52 and a mounting side flange 53, upper and lower webs 54, 55 that vertically connect both, and a web 56 in the center in the vertical direction. , 53 and the upper and lower webs 54, 55 constitute a substantially rectangular cross section (generally a general cross section with the web 56 inserted). However, when the cross section is divided into approximately two equal parts in the vertical direction to be the upper part and the lower part, respectively, the part connecting the upper part and the lower part of the collision side flange 52, that is, the central part is bent. And it is a substantially sun-shaped cross section. The attachment side flange 53 and the webs 54 to 56 are all uniform in thickness. Further, in each of the upper part and the lower part, the collision side flange 52 and the attachment side flange 53 are parallel to each other.
The under-run protector 51 is different from the under-run protector 21 shown in FIG. 2A in that the collision side flange 52 is bent at the center (bent so that the lower part protrudes forward). This is basically the same as the run protector 21.

In FIG. 3B, 52a is a thin portion of the collision side flange 52, 52b is a thick portion, 16 is a bolt hole, and 17 is a mounting work hole. The front surface of the collision side flange 52 is flat above and below the bent portion.
For example, depending on the design of the track, it is conceivable to adopt a vertically asymmetrical one such as the underrun protector 51. Contrary to the under protector 51, the upper portion may protrude forward.

The underrun protector 61 shown in FIG. 3C includes a collision side flange 62 and a mounting side flange 63 which are parallel to each other, upper and lower webs 64 and 65 which are parallel to each other, and a web 66 in the center in the vertical direction. The two flanges 62 and 63 and the upper and lower webs 64 and 65 constitute a substantially rectangular cross section (a generally cross section having a general shape when the web 66 is inserted). However, since the webs 64 to 66 are slightly tilted from the vertical with respect to the collision side flange 62 and the attachment side flange 63, they have a slightly deformed substantially rectangular cross section and substantially sun-shaped cross section. The attachment side flange 63 and the webs 64 to 66 are all uniform in thickness.
The under-run protector 61 is different from the under-run protector 21 shown in FIG. 2A in that the webs 64 to 66 are slightly inclined from the vertical with respect to the collision side flange 62 and the mounting side flange 63. Then, it is basically the same as the underrun protector 21.

In FIG. 3 (c), 62a is a thin part of the collision side flange 62, 62b is a thick part, 16 is a bolt hole, and 17 is a mounting work hole. When the collision side flange 62 and the attachment side flange 63 are divided into approximately two equal parts at the upper part and the lower part with the web 66 as a boundary, the webs 64 to 66 are inclined, so that the bolt hole 16 and the attachment work hole 17 are respectively attached to the attachment side flange. 63 and the center side of the collision side flange 62 are slightly shifted up and down.
In addition, by giving an initial fraud with an up-down asymmetry like the underrun protector 61, it is possible to adjust the crushing deformation load peak value when the collision vehicle collides with the vicinity of the attachment portion with the vehicle body frame. Contrary to the underrun protector 61, the web can be inclined in the direction in which the rear side is lowered.

The underrun protector 71 shown in FIG. 4 (a) includes a collision side flange 72 and a mounting side flange 73 that are parallel to each other, upper and lower webs 74, 75 that vertically connect both, and a web 76 at the center in the vertical direction. Both flanges 72 and 73 and upper and lower webs 74 and 75 form a substantially rectangular cross section. The attachment side flange 73 and the webs 74 to 76 are all uniform in thickness. The underrun protector 71 differs from the underrun protector 21 only in the cross-sectional shape of the collision side flange 72, and is basically the same as the underrun protector 21 in other points.
In FIG. 4A, 72a is a thin part, 72b is a thick part, 16 is a bolt hole, and 17 is an attachment work hole. Unlike the collision side flange 22 of the underrun protector 21, the collision side flange 72 is flat on the rear side of the cross section, and continues from the thin part 72a to the thick part 72b via a transition part inclined on the front side.

The underrun protector 81 shown in FIG. 4B is composed of a collision side flange 82 and a mounting side flange 83 that are parallel to each other, upper and lower webs 84 and 85 that vertically connect both, and a web 86 at the center in the vertical direction. Both flanges 82 and 83 and the upper and lower webs 84 and 85 form a substantially rectangular cross section. The attachment-side flange 83 and the webs 84 to 86 are all uniform in thickness. The under-run protector 81 differs from the under-run protector 21 only in the cross-sectional shape of the collision side flange 82 and is basically the same as the under-run protector 21 in other points.
In FIG. 4 (b), 82a is a thin part, 82b is a thick part, 16 is a bolt hole, and 17 is a mounting work hole. Unlike the collision side flange 22 of the under-run protector 21, the collision side flange 82 is continuous from the thin portion 82a to the thick portion 82b via a transition portion inclined on the front side and the rear side of the cross section.

  The underrun protector 91 shown in FIG. 4C includes a collision side flange 92 and a mounting side flange 93 that are parallel to each other, upper and lower webs 94 and 95 that vertically connect both, and a web 96 in the center in the vertical direction. Both flanges 92 and 93 and upper and lower webs 94 and 95 form a substantially rectangular cross section. However, the corners of the flanges 92 and 93 and the webs 94 to 96 are provided with a large R (curvature radius). The attachment-side flange 93 and the webs 94 to 96 are all uniform in thickness except for the vicinity of the corner portion. The under-run protector 91 differs from the under-run protector 21 only in that a large R is added to the corner portion, and is basically the same as the under-run protector 21 in other points.

In FIG. 4 (c), 82 a is a thin part, 82 b is a thick part, 16 is a bolt hole, and 17 is an attachment work hole 17.
In the under-run protector 91, the flanges 92 and 93 and the corners of the webs 94 to 96 are all provided with a large R, but either of the inner corner portion Ra or the outer corner portion Rb of both the flanges 92 and 93 is provided. Only one side is provided with a large R, or either one of the flanges 92 and 93 is large in both the inner corner portion Ra and the outer corner portion Rb, or only in one of the inner corner portion Ra and the outer corner portion Rb. R can be attached. By attaching a large R to the outer corner portion Rb of the attachment-side flange 93, the crushing deformation load peak value when the collision vehicle collides with the vicinity of the attachment portion with the vehicle body frame can be adjusted.

In addition, the following points are supplemented as a precaution for the underrun protector shown in FIGS.
(1) Even under lamp protectors other than the under lamp protector 91 shown in FIG. 4 (c), generally small corners R are formed at the respective inner and outer corner portions. The illustration is only simplified.
(2) The thickness of the flange and the web may not be strictly uniform. Further, it is not necessary to place the intermediate web at exactly two equal parts or three equal parts.
(3) The forms of the underrun protector shown in FIGS. 1 to 4 can be combined. For example, there may be an under protector having the features of both (a) and (c) of FIG. Moreover, it is not limited to the form of FIGS.

It is sectional drawing which shows the cross-sectional shape and attachment form of the underrun protector which concerns on this invention. It is sectional drawing of another underrun protector which concerns on this invention. It is sectional drawing of another underrun protector which concerns on this invention. It is sectional drawing of another underrun protector which concerns on this invention. It is sectional drawing of the conventional underrun protector. It is a top view explaining the fracture | rupture of the underrun protector at the time of the attachment form to the vehicle body frame of an underrun protector and an edge collision. It is a side view explaining the attachment form to the vehicle body frame of an under lamp protector.

Explanation of symbols

11, 21, 31, 41, 51, 61, 71, 81, 91 Underrun protector 12, 22, 32, 42, 52, 62, 72, 82, 92 Collision side flanges 12a, 22a, 32a, 42a, 52a, 62a, 72a, 82a, 92a Thin portion 12b, 22b, 32b, 42b, 52b, 62b, 72b, 82b, 92b Thick portion 13, 23, 33, 43, 53, 63, 73, 83, 93 Mounting side flange 14 , 24, 34, 44, 54, 64, 74, 84, 94 Upper web 15, 25, 35, 45, 55, 65, 75, 85, 95 Lower web 26, 36, 37, 46, 56, 66, 76 , 86, 96 Intermediate web 16 Bolt hole 17 Installation hole

Claims (2)

It is an under-run protector that is attached to the body frame of a truck with bolts and nuts, and is made of an aluminum alloy extruded profile with a hollow cross section having a collision side flange, a mounting side flange, and a plurality of webs that connect both, and the collision side flange is A thin wall portion and a thick wall portion above and below it, a bolt hole is formed in the mounting portion of the mounting side flange with the vehicle body frame, and the thin wall portion is located in front of the bolt hole of the collision side flange. An underrun protector for a track, wherein a mounting hole corresponding to the bolt hole is formed. A hollow section having an underrun protector that is installed on a body frame of a truck and is attached to an intermediate part extending downward from the body frame with bolts and nuts, and having a collision side flange, an attachment side flange, and a plurality of webs for connecting the flanges The collision-side flange has a thin-walled portion and a thick-walled portion above and below it, and a bolt hole is formed in the attachment portion with the intermediate part of the attachment-side flange. An under-run protector for a truck, wherein the thin portion is provided at a front position of the hole, and an attachment work hole corresponding to the bolt hole is formed therein.

Images