JP2010132059A - Underrun protector fixing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underrun protector fixing structure for protecting a side frame from collision load during a slight collision. <P>SOLUTION: A web surface 5a fixed to a web surface of the side frame and a first flange surface 5b extended from one end of the web surface 5a to the outside in a vehicle width direction and fixed to the underrun protector, are disposed on a first member 5. An upper surface 6a fixed to the flange surface and the web surface 5a of the side frame, a front surface 6b extended vertically downward from one end of the upper surface 6a and fixed to the underrun protector, and a side surface 6c curvedly formed from the front surface 6b in a back and forth direction of the vehicle and fixed to the web surface 5b are disposed on a second member 6. In a region below the flange surface of the side frame and above the upper end of the underrun protector, the flange height of the first flange surface 5b is made small to form a clearance S between the upper surface 6a and the side surface 6c. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fixing structure for an underrun protector provided at front and rear ends of a chassis frame.

  Conventionally, a bumper member called an under-run protector is attached to a chassis frame of a large vehicle such as a truck or a tractor. The underrun protector is for preventing the other vehicle from getting into the lower part of the frame at the time of contact or collision with another vehicle. In general, the under-run protector is required to have a predetermined strength that can sufficiently withstand the load at the time of a collision, and the fixing structure from the under-run protector to the chassis frame is fastened or fixed by welding.

For example, in Patent Document 1, a mounting bracket having a T-shaped horizontal cross section is used as a bracket for fixing an underlamp protector (FUP main body) made of a hollow material to a chassis frame (side frame), and these are used as bolts and rivets. A structure that is rigidly fixed by welding or the like is disclosed. In this technique, it is said that by using a mounting bracket having a T-shaped cross-sectional structure, the strength equivalent to that of a box-shaped closed cross-sectional structure can be secured with a small amount of material.
JP 2008-062838 A

  However, in the conventional structure described in Patent Document 1, almost all of the load is input to the chassis frame regardless of the magnitude of the load input to the underrun protector. For example, even if a slight load is input to the underrun protector due to slight contact when entering the garage, the load may act on the chassis frame and cause slight deformation of the chassis frame. Absent. For this reason, even if a major collision as originally assumed in the underrun protector has not occurred, the chassis frame needs to be repaired or replaced, which is time and costly for the vehicle user. There is a problem that the burden will be forced.

  Further, in the conventional structure, the mounting bracket is extended below the chassis frame to support the underrun protector so that the ground clearance is less than the vehicle safety reference value. For this reason, when a load is applied to the underrun protector, there is also a problem that the mounting bracket is rotated inward of the vehicle body around the vicinity of the joint portion between the chassis frame and the mounting bracket and easily interferes with the chassis frame. In other words, the chassis frame may be deformed by the movement of the mounting bracket.

  The present invention has been made in view of such a problem, and an object thereof is to provide an underrun protector fixing structure capable of protecting a side frame from an impact load at the time of a slight collision.

  The underrun protector fixing structure of the present invention (Claim 1) is a vehicle having a vertically oriented frame web surface and a frame flange surface extending inwardly in the vehicle width direction from the lower end of the frame web surface. A fixing structure for fixing an under-run protector extending in a vehicle width direction below the frame flange surface to the side frame, the web surface being fixed to the frame web surface and vertically oriented; A first member having a first flange surface extending from one end of the web surface in the vehicle front-rear direction to the vehicle width direction and fixed to the underrun protector; and a horizontally oriented frame flange surface and the web An upper surface fixed to the surface, a front surface extending vertically downward from one end of the upper surface in the vehicle front-rear direction and fixed to the underrun protector, A second member having a side surface that is bent in the vehicle front-rear direction and fixed to the web surface of the first member. The horizontal width in the vehicle width direction in a portion where one flange surface is located below the frame flange surface and above the upper end of the under-run protector compared to a portion located below the upper end of the under-run protector The first deformable portion is formed small, and the side surface of the second member includes a second deformable portion formed as a gap between the upper surface and the second member.

  Moreover, in addition to the structure of Claim 1, the front surface of the underrun protector fixing structure of the present invention is located below the frame flange surface and above the upper end of the underrun protector. The part is characterized by comprising a third deformed part formed so as to have a smaller horizontal width in the vehicle width direction than a part located below the upper end of the underrun protector.

  The under-run protector fixing structure according to the present invention (Claim 3) has the structure according to claim 1 or 2, wherein the web surface is below the frame flange surface and above the upper end of the under-run protector. The vehicle is characterized by comprising a fourth deformed portion having a horizontal width in the vehicle front-rear direction smaller than that of the portion positioned above the frame flange surface.

  Moreover, in addition to the structure of any one of Claims 1-3, this 1st member is the other end of the vehicle surface front-back direction of this web surface. A second flange surface that extends outward in the vehicle width direction, and a reinforcing surface that horizontally connects the first flange surface and the second flange surface below the upper end of the underrun protector. And the second member extends vertically downward from the other end of the upper surface in the vehicle longitudinal direction and outward in the vehicle width direction, and below the upper end of the underrun protector, with respect to the second flange surface. It is characterized by further having a fixed rear surface.

  According to the underrun protector fixing structure of the present invention (Claim 1), the first deformed portion of the first member and the second deformed portion of the second member are both lower than the frame flange surface and more than the upper end of the underrun protector. By providing in the upper range, the first member and the second member can be easily deformed in the horizontal direction when an impact is input to the under-run protector, and the stress transmitted to the side frame can be reduced. Thereby, a side frame can be protected from a slight impact load.

Moreover, according to the under-run protector fixing structure of the present invention (Claim 2), the joint rigidity between the front surface and the upper surface of the second member can be reduced, and the deformation in the horizontal direction is more reliably promoted. can do.
Further, according to the underrun protector fixing structure of the present invention (Claim 3), the first member is arranged by aligning the disposition position of the first deformation portion and the disposition position of the fourth deformation portion in the height direction. It can be easily deformed in the horizontal direction.

  In addition, according to the underrun protector fixing structure of the present invention (Claim 4), the rigidity of the first member and the second member below the upper end of the underrun protector is ensured, so that it can be deformed in the horizontal direction. The upward movement can be suppressed, and the side frame can be more reliably protected.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 5 are for explaining an underrun protector fixing structure according to an embodiment of the present invention. FIG. 1 is a perspective view showing a front end portion of a chassis frame to which the fixing structure according to the present invention is applied. 2 (a) and 2 (b) are perspective views of the stay according to the present fixing structure, (a) is a view as seen from the arrow A in FIG. 1, and (b) is a view as seen from the arrow B in FIG. .

  FIGS. 3A to 3C are three views of the first member of the stay according to the present fixing structure, and FIGS. 4A to 4C are three views of the second member of the stay according to the fixing structure. FIGS. 5A and 5B are side views for explaining the operation of the present fixing structure.

[1. overall structure]
This fixing structure is applied as a fixing structure of a front under-run protector 3 (hereinafter referred to as FUP 3) fixed to the chassis frame of the vehicle shown in FIG. The chassis frame includes a pair of left and right side frames 1 that extend in the vehicle front-rear direction, and a cross member 2 that connects the side frames 1 in the vehicle width direction. The side frame 1 has a U-shaped frame web surface 1a and a frame flange surface 1b extending horizontally inward in the vehicle width direction from the upper and lower ends of the frame web surface 1a. The cross section is formed.

  The FUP 3 extends horizontally in the vehicle width direction below the front end of the side frame 1, and is fixed to the frame web surface 1 a and the frame flange surface 1 b of the side frame 1 via the bracket 4. Yes.

[2. Mounting structure]
2A and 2B are perspective views of the bracket 4 that connects the FUP 3 and the side frame 1 on the left side in the vehicle width direction. The bracket 4 includes a first member 5 and a second member 6. The first member 5 and the second member 6 are fixed to each other and formed integrally. The bracket 4 has a predetermined strength set in advance, and has a structure that absorbs the impact in a horizontal direction by slight deformation against a slight collision.

[2-1. First member]
As shown in FIG. 2A, the first member 5 includes a web surface 5a, a first flange surface 5b, a second flange surface 5c, a reinforcing surface 5d, and a bottom surface 5e. The web surface 5a is a flat portion fixed in a state of surface contact with the frame web surface 1a of the side frame 1, and is oriented vertically along the frame web surface 1a. A bolt hole (attachment hole) for fastening with the side frame 1 is formed in the vicinity of the upper end of the web surface 5a.

  A first flange surface 5b and a second flange surface 5c are extended from both ends of the web surface 5a in the vehicle front-rear direction. The first flange surface 5b is a portion erected from the front end (one end in the vehicle front-rear direction) of the web surface 5a toward the outside in the vehicle width direction, and is fixed in a state where the rear surface 3a of the FUP 3 is in surface contact therewith. Yes. Bolt holes (mounting holes) for fastening with the rear surface 3a of the FUP 3 are formed in the first flange surface 5b. Further, the second flange surface 5c is a portion that is erected from the rear end (the other end in the vehicle longitudinal direction) of the web surface 5a toward the outside in the vehicle width direction.

A reinforcing surface 5d is disposed between the first flange surface 5b and the second flange surface 5c. The reinforcing surface 5d is substantially the same height as the upper end of the FUP 3 that contacts the first flange surface 5b, and horizontally connects the first flange surface 5b and the second flange surface 5c.
Moreover, the bottom part 5e is fixed so that the lower end part of each of the web surface 5a, the 1st flange surface 5b, and the 2nd flange surface 5c may be plugged up from the downward direction. The bottom 5e is a member provided for placing the vehicle on a rigid rack after jacking up, and is horizontally oriented.

[2-2. Detailed configuration of first member]
3B and 3C, the alternate long and short dash line indicates the height of the frame flange surface 1b when the side frame 1 and the FUP 3 are fixed to the bracket 4, and the alternate long and two short dashes line indicates the upper end of the FUP 3 in the same state. Indicates the height.
As shown in FIG. 3 (c), the first flange surface 5b, the shape such that the height H ₁ of the flange is higher nears from one-dot chain line side to the two-dot chain line side is set. Further, below the two-dot chain line, the height H _{1 of the} flange is further increased in order to increase the contact area with the FUP 3. That first flange surface 5b, to the extent that is sandwiched between the one-dot chain line and two-dot chain line, two-dot vehicle width direction horizontal width H ₁ in comparison with the portion positioned below the chain line (i.e. the height of the flange) Is formed small. As a result, when a load is applied to the FUP 3, the portion having a small flange height H ₁ sandwiched between the one-dot chain line and the two-dot chain line functions as the first deformable portion 8 A that is more easily deformed than the other portions. It has become.

Further, as shown in FIG. 3B, the web surface 5a is formed in a shape extending toward the front of the vehicle above the two-dot chain line. That is, the first flange surface 5b is formed to be bent forward above the two-dot chain line. On the other hand, the second flange surface 5 is oriented substantially vertically even above the two-dot chain line. Further, above the one-dot chain line, the member width W ₁ of the web surface 5a is increased in order to increase the contact area of the side frame 1 with the frame web surface 1a. That is, in the range sandwiched between the web surface 5a and the alternate long and short dash line, the vehicle front-rear horizontal width W ₁ (that is, the member width) is formed smaller than the portion located above the alternate long and short dash line. . Thus, when a load is applied to the FUP3, as small sites member width W ₁ sandwiched between the dashed line and two-dot chain line, acts as a fourth modified portions 8D which easily deformed than other portions It has become.

  As shown in FIG. 3 (b), the reinforcing surface 5d is positioned below the two-dot chain line, so when a load is applied to the FUP 3, both the web surface 5a and the reinforcing surface 5d are used. A load is transmitted from the first flange surface 5b to the second flange surface 5c. In addition, the 1st member 5 is formed in the box shape by which the vehicle width direction outer side was open | released by the web surface 5a, the 1st flange surface 5b, the 2nd flange surface 5c, the reinforcement surface 5d, and the bottom face 5e. Since the inside of the box shape is hollow, bending deformation to the inside of the first flange surface 5b is allowed.

[2-3. Second member]
As shown in FIG. 2B, the second member 6 includes an upper surface 6a, a front surface 6b, a side surface 6c, a rear surface 6d, and a second reinforcing surface 6e. The upper surface 6a is a flat portion fixed in a state of surface contact with the frame flange surface 1b of the side frame 1, and is horizontally oriented along the frame flange surface 1b. Bolt holes (mounting holes) for fastening with the side frames 1 are drilled in the upper surface 6a. Further, the upper surface 6 a is fixed by welding to the web surface 5 a of the first member 5.

  A front surface 6b extends vertically downward from a front end portion (one end in the vehicle longitudinal direction) of the upper surface 6a. The front surface 6b is a flat portion fixed in a state of surface contact with the rear surface 3a of the FUP 3, and a fastening bolt hole (mounting hole) is drilled in the front surface 6b. On the other hand, a rear surface 6d extends from the rear end portion (the other end portion in the vehicle longitudinal direction) of the upper surface 6a. The rear surface 6d is a portion that extends vertically downward from the upper surface 6a and outward in the vehicle width direction, and is fixed to the second flange surface 5c of the first member 5 by welding at an end thereof.

  A side surface 6c that is bent toward the rear of the vehicle is provided at an end of the front surface 6b on the outer side in the vehicle width direction. The side surface 6 c is a flat portion that is welded and fixed to the web surface 5 a of the first member 5. The second reinforcing surface 6e is disposed orthogonally so as to be perpendicular to the front surface 6b and the side surface 6c.

[2-4. Detailed configuration of second member]
4A and 4B, the alternate long and short dash line indicates the height of the frame flange surface 1b when the side frame 1 and the FUP 3 are fixed to the bracket 4, and the alternate long and two short dashes line indicates the upper end of the FUP 3 in the same state. Indicates the height.

  As shown in FIG. 4B, the upper surface of the side surface 6c is disposed below the lower edge of the upper surface 6a so that a gap S is formed between the side surface 6c and the upper surface 6a. The gap S is located within a range sandwiched between the alternate long and short dash line. As a result, when a load is applied to the FUP 3, the gap S functions as a second deformable portion 8B (that is, a deformable portion) that allows relative displacement between the upper surface 6a and the side surface 6c.

When attention is paid to a portion where the upper surface 6a and the side surface 6c are connected, as shown in FIG. 4A, a notch 7 is cut on the side surface 6c side in the vicinity of the upper end portion of the front surface 6b. Notch 7 so as to reduce the member width W ₂ of the front 6b partly is a portion which is recessed inward. In other words, the front 6b, to the extent that is sandwiched between the one-dot chain line and two-dot chain line, compared with the portion positioned below the two-dot chain line, reduce the vehicle width direction horizontal width W ₂ (i.e. member width) formed Has been. Thereby, when a load is applied to the FUP 3, the portion where the horizontal width W ₂ is narrowed by the notch 7 between the one-dot chain line and the two-dot chain line is more easily deformed than the other portions. To work as.

  Note that the web member 5a, the upper surface 6a, the front surface 6b, and the rear surface 6d form the second member 6 in a box shape in which the inner side and the lower side in the vehicle width direction are opened. Since the inside of the box shape is hollow, bending deformation to the inside of the front surface 6b is allowed.

[3. Action]
As shown in FIG. 5A, when a horizontal load P is applied to the FUP 3, the load P is transmitted from the rear surface 3a of the FUP 3 to both the first member 5 and the second member 6.

In the first member 5, the load P acts horizontally in a range below the two-dot chain line in FIG. The first flange portion 5b, because they are formed so that the height H ₁ of the flange is small in a range sandwiched by the one-dot chain line and two-dot chain line, site sandwiched between the one-dot chain line and two-dot chain line Try to deform horizontally. Also in the web surface 5a, since the member width W ₁ is formed to be smaller in a range sandwiched by the one-dot chain line and two-dot chain line, a portion sandwiched between the dashed line and two-dot chain line horizontal Try to deform in the direction.

Similarly, in the second member 6, the load P acts horizontally in the range below the two-dot chain line in FIG. Since a gap S is formed between the upper surface 6a and the side surface 6c of the second member 6 in a range sandwiched between the alternate long and short dash line, the portion sandwiched between the alternate long and short dash line Tries to deform horizontally. Also in front 6b, because the members width W ₂ is formed to be small in the range sandwiched between the one-dot chain line and two-dot chain line, horizontally sandwiched sites in the chain line and two-dot chain line Try to transform into.

  By these actions, the bracket 4 is deformed in the horizontal direction while buffering the load P at a portion sandwiched between the one-dot chain line and the two-dot chain line. At this time, as shown in FIG. 5B, almost no displacement is generated on the upper surface 6a of the second member 6, and the upper surface 6a and the reinforcing surface 5d are located at a portion sandwiched between the alternate long and short dash line. Displacement occurs while maintaining a substantially parallel state. Since the bracket 4 does not rotate around the vicinity of the fixed portion between the side frame 1 and the bracket 4, there is no interference between the side frame 1 and the bracket 4.

  When a larger load P is applied, the front surface 6b tends to deform rearward of the vehicle while buffering the load P in a range below the two-dot chain line. On the other hand, the first member 5 and the second member 6 are provided with spaces that allow deformation of the first flange portion 5b and the front surface 6b, respectively. The whole member 5 and the second member 6 are deflected so as to be deformed inward, and deformed in the horizontal direction. Therefore, regardless of the magnitude of the load P, interference between the side frame 1 and the bracket 4 does not occur.

[4. effect]
As described above, according to the fixing structure of the underrun protector, both the first member 5 and the second member 6 are provided in the region between the one-dot chain line indicating the frame flange surface 1b and the two-dot chain line indicating the upper end of the FUP 3. By adopting a structure having a portion that is easily deformed, the bracket 4 can be easily deformed in the horizontal direction when a load is applied to the FUP 3, and the stress transmitted to the side frame 1 can be reduced. Thereby, the side frame 1 can be protected from a slight impact load.

Further, in the first member 5, a fourth of the mounting heights of the first deformed portion 8A of the height H ₁ of the first flange face 5b is formed to be smaller, the member width W ₁ of the web surface 5a is smaller By aligning the arrangement height of the deforming portion 8D, it can be easily deformed in the horizontal direction. Similarly, in the second member 6, the mounting heights of the second deformation portion 8B formed as a gap S, the mounting heights of the third modified portion 8C which member the width W ₂ of the front 6b is smaller By aligning, it can be easily deformed in the horizontal direction.

Moreover, by forming the notch 7 in the front surface 6b of the second member 6, the joint stiffness at the joint between the front surface 6b and the upper surface 6a can be reduced, and the deformation in the horizontal direction can be more reliably promoted. There is also an effect that can be done.
Furthermore, since both the first member 5 and the second member 6 are formed in a hollow box shape, the inner flange of the first flange surface 5b and the front surface 6b is allowed to be deformed. It can be reliably deformed in the horizontal direction. In addition, by securing the rigidity of the first member 5 and the second member 6 below the upper end of the FUP 3, it is possible to suppress the upward movement of the bracket 4 at the time of deformation in the horizontal direction, and more reliably. The side frame 1 can be protected.
As described above, according to the underrun protector fixing structure, the side frame 1 can be protected from an impact load at the time of a slight collision.

[5. Others]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment etc., It can implement in various deformation | transformation in the range which does not deviate from the meaning of this invention.
In the above-described embodiment, a structure in which the bracket 4 is provided with four types of deformable portions (first deformable portion 8A to fourth deformable portion 8D) is illustrated, but at least the first deformable portion 8A on the first member 5 side. And a second deformation portion 8B on the second member 6 side. By providing the members that allow deformation in both members, the same effects as in the above-described embodiment can be obtained.

  In the above-described embodiment, the fixing structure of the front under-run protector 3 provided at the front end of the chassis frame is shown. However, the structure may be applied as a fixing structure of the rear under-run protector provided at the rear end of the chassis frame. Good. The present invention can be applied not only to large vehicles such as trucks, tractors, and bus vehicles, but also to fixed structures for automobiles, box-type vehicles, and the like that have an underrun protector on a chassis frame.

  In addition, regarding the specific fixing method (for example, bolt fastening fixing, welding fixing, etc.) between members in the above-described embodiment, it may be appropriately changed according to design conditions such as rigidity and strength required for the members. .

It is a perspective view which shows the chassis frame front-end part to which the fixing structure based on this invention was applied. It is a perspective view of the stay which concerns on this fixed structure, (a) is A arrow directional view in FIG. 1, (b) is B arrow directional view in FIG. It is a three-plane view of the first member of the stay according to the present fixing structure, (a) is a top view, (b) is a side view on the outer side in the vehicle width direction, and (c) is a side view on the rear side of the vehicle. It is a three-view figure of the 2nd member of the stay which concerns on this fixed structure, (a) is a side view of a vehicle rear, (b) is a side view inside a vehicle width direction, (c) is a bottom view. It is a typical side view for demonstrating the effect | action by this fixed structure, (a) shows the state before a deformation | transformation by a horizontal load, (b) shows the state after a deformation | transformation.

Explanation of symbols

1 Side frame 1a Frame web surface 1b Frame flange surface 2 Cross member 3 Front underrun protector (FUP, underrun protector)
4 bracket 5 first member 5a web surface 5b first flange surface 5c second flange surface 5d reinforcing surface 5e bottom surface 6 second member 6a upper surface 6b front surface 6c side surface 6d rear surface 6e second reinforcing surface 7 notch 8A first deforming portion 8B Second deformation part 8C Third deformation part 8D Fourth deformation part

Claims (4)

With respect to a side frame of a vehicle having a vertically oriented frame web surface and a frame flange surface extending inwardly in the vehicle width direction from the lower end portion of the frame web surface, the vehicle width is below the frame flange surface. A fixing structure for fixing an underrun protector extending in a direction,
A web surface that is fixed to the frame web surface and is vertically oriented; and a first flange surface that extends outwardly from one end of the web surface in the vehicle longitudinal direction and is fixed to the underrun protector. A first member;
An upper surface that is horizontally oriented and fixed to the frame flange surface and the web surface; a front surface that extends vertically downward from one end in the vehicle longitudinal direction of the upper surface and is fixed to the underrun protector; and A second member having a side surface that is bent in the vehicle front-rear direction and fixed to the web surface of the first member from an end portion on the outer side in the vehicle width direction,
The first flange surface of the first member is lower than the frame flange surface and higher than the upper end of the under-run protector, compared with a portion positioned lower than the upper end of the under-run protector. And the first deformation part formed to reduce the horizontal width in the vehicle width direction,
The under-run protector fixing structure, wherein the side surface of the second member includes a second deformed portion formed as a gap with the upper surface. When the front surface is located below the frame flange surface and above the upper end of the underrun protector, the horizontal width in the vehicle width direction is larger than the portion located below the upper end of the underrun protector. The underrun protector fixing structure according to claim 1, further comprising a third deformation portion formed to be small. When the web surface is located below the frame flange surface and above the upper end of the under-run protector, the horizontal width in the vehicle front-rear direction is smaller than the portion located above the frame flange surface. The underrun protector fixing structure according to claim 1, further comprising a fourth deformed portion formed. The first member has a second flange surface extending outward in the vehicle width direction from the other end of the web surface in the vehicle front-rear direction, and below the upper end of the underrun protector, the first flange surface and the A reinforcing surface that horizontally connects the second flange surfaces, and
The second member extends vertically downward from the other end in the vehicle longitudinal direction on the upper surface and outward in the vehicle width direction, and is fixed to the second flange surface below the upper end of the underrun protector. The underrun protector fixing structure according to any one of claims 1 to 3, further comprising a rear surface.