JP2000296743A - Shock absorbing front underrun protector - Google Patents

Abstract

(57) [Problem] To provide a small and lightweight enough and smooth absorption of impact energy when an impact force is applied to a vehicle having a protector under a front surface of a chassis frame for preventing another low-height vehicle from sneaking into the vehicle. And a shock-absorbing front underrun protector. SOLUTION: Between a bracket 5 fixed below a front portion of a side member 8 of a chassis frame 7 and a protector 4, an impact energy absorbing device including an FRP energy absorber 2 and a tubular body 3 enclosing the FRP energy absorber. 1 is interposed. Since the tubular body 3 is provided with the slit 10, the fragments of the FRP energy absorber 2 are smoothly crushed when an impact force is applied, so that a sufficient impact energy absorbing effect is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock-absorbing type front under which is mounted on the front side of a vehicle such as a heavy-duty truck so as to prevent a vehicle having a low height from sneaking in and smoothly absorb shock energy. Regarding the run protector.

[0002]

2. Description of the Related Art As shown in FIG. 18, relatively high rigidity is provided on the front side of a vehicle such as a large truck having a high vehicle height to prevent a vehicle having a low vehicle height from sneaking in when an accident such as a frontal collision occurs. Protectors 4a are provided in some foreign vehicles and are being provided in Japan. The protector 4a is fixed to a bracket 5a arranged near the cross member 9 at the front end of the chassis frame 7, and constitutes a front underrun protector as a whole.

On the other hand, at the time of a collision, since a partner vehicle collides with the protector 4a, a considerably large impact force acts on the chassis frame 7 side. Therefore, an impact energy absorbing device that absorbs impact energy has been conventionally studied. FIG. 19 shows a schematic structure of the impact energy absorbing device connected to the bumper 17 which also functions as the protector 4a. This shock energy absorbing device is a bumper 1
It comprises an energy absorbing damper 18 and a fluid cylinder 19 interposed between the upper and lower portions of the chassis 7 and the chassis frame 7, and a control section 20 for controlling the hydraulic pressure of these components.

[0004]

The energy absorbing damper 18 and the fluid cylinder 19 of the impact energy absorbing device shown in FIG. 19 have a considerably long axial length, and such a long length is provided below the front surface of the chassis frame 7. If the above member is arranged, there is a problem in securing a space and the weight increases, which is not preferable. Therefore, a lightweight and small impact energy absorbing member is required.

[0005] On the other hand, as a known technique relating to a relatively lightweight and small impact energy absorber, for example, Japanese Patent Laid-Open No. 8-1 is disclosed.
Japanese Patent Application Laid-Open No. 21520, Japanese Patent Application Laid-Open No. 8-219215, Japanese Patent Application Laid-Open No. 6-307476, and the like. Each of these FRP energy absorbers has characteristics and can effectively absorb impact energy. However,
These FRP energy absorbers are mounted alone on the front surface of a chassis frame or the like of a vehicle, and do not have the function as the protector.

Therefore, a technique of providing a hard tubular body made of metal or the like which covers the conventional FRP energy absorber outside the conventional FRP energy absorber is adopted. FIG. 20 and FIG. 21 show a deformed state when an impact force acts on the impact energy absorbing device of such a form. Due to the action of the impact force, the front sides of the FRP energy absorber 2e and the tubular body 3e start to deform as shown in FIG. At this time, the FRP energy absorber 2
The debris 14 generated in e is bent outward and inward. At the same time, the tubular body 3e is deformed into a bellows shape. Therefore, the outer surface of the fragment 14 bent outwardly of the FRP energy absorber 2 e
Presses against the inner surface of e. As a result, even if a greater impact force acts, the FRP energy absorber 2e does not smoothly absorb the impact energy. On the other hand, as shown in FIG. 21, even when the inner diameter of the tubular body 3e is increased and the gap 21 is provided between the tubular body 3e and the FRP energy absorber 2e, the tubular body 3e is completely formed in a bellows shape by the action of the impact force. It is possible that the FRP energy absorber 2e will not be able to smoothly absorb the impact energy.

The present invention has been made in view of the above circumstances, and has a front underrun protector function, and can effectively and smoothly absorb impact energy, and has a small size and light weight. It is an object of the present invention to provide a mold front underrun protector.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention is to prevent a low-height vehicle from sneaking under a high-height vehicle and absorb the impact energy of the vehicle. A shock absorbing front underrun protector disposed below a front surface of a chassis frame, the shock absorbing front underrun protector being disposed along a vehicle width direction, and a lower surface of the chassis frame. And a tubular impact energy absorbing device interposed between the bracket and the protector or fixed to the front surface of the protector. The impact energy absorbing device has an FRP energy An impact-absorbing type filter comprising an absorber and a tubular body of a hard material enclosing the absorber, wherein the tubular body is formed with a slit communicating with the inner and outer surfaces. It constitutes a door underrun protector. More specifically, the FRP energy absorber is formed of a hollow cylinder, the tubular body is formed of a cylindrical pipe, and a tapered portion (trigger) is formed at one or both ends of the FRP energy absorber. A plurality of the slits are equally formed in the cylindrical pipe. Further, the FRP energy absorber is formed of a prismatic member, the tubular body is formed of a prismatic pipe having a cross-sectional shape similar to the energy absorber, and one end or both ends of the FRP energy absorber are tapered ( (Trigger) is formed, and the slit is formed at a corner of the prismatic pipe. Further, the FRP energy absorber is formed of a substantially H-shaped cross section, and the tubular body is formed of a prismatic pipe.
Is formed, and the slit is formed at a corner of the prismatic pipe.

[0009] The FRP energy absorber is encapsulated by a hard tubular body and is formed into a relatively rigid body having an integral shape. Therefore, the impact energy absorbing function can be added to the function of the protector by engaging the impact energy absorbing device composed of the two with the protector and disposing it on the front side below the chassis frame. Since the tubular body has a slit, the tubular body does not deform in a bellows shape when an impact force acts, and the FRP energy absorber can sufficiently and smoothly absorb the impact energy. Further, the shock-absorbing front underrun protector of the present invention is made of a compact body, and is formed small and light.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a shock absorbing type front underrun protector according to an embodiment of the present invention. FIGS. 1 to 4 show a shock-absorbing front underrun protector (hereinafter simply referred to as a shock-absorbing protector) of the present invention, and a structure of disposing the shock-absorbing protector below a front surface of a chassis frame 7. As shown in FIG. 1, the shock-absorbing protector includes a protector 4 and
It comprises a bracket 5 fixed to the chassis frame 7 and the impact energy absorbing device 1. In FIG. 1, the impact energy absorbing device 1 is provided between the protector 4 and the bracket 5, but in FIG. 4, the impact energy absorbing device 1 is provided between the front plate 6 and the protector 4. In this case, the protector 4 is fixed to the bracket 5. 1 to 4, the protector 4 is formed of a square, highly rigid cylindrical member having a gap therein. The bracket 5 fixed below the side members 8, 8 of the chassis frame 7 is made of a highly rigid block body. Also, the front plate 6 is formed of a rigid plate having an appropriate thickness to function as a protector.

The impact energy absorbing device 1 comprises an FRP energy absorber 2 and a tubular body 3 enclosing the same.
These are made of various shapes as described below, but all the tubular bodies 3 are provided with slits 10.

5 to 11 show components and the like in one embodiment of the impact energy absorbing device 1. FIG. As shown in FIGS. 5 and 6, in this embodiment, the FRP energy absorber 2a is formed of a hollow cylindrical member, and is entirely formed of, for example, a fiber-reinforced composite material, and has one end (side end receiving an impact force). Is formed with a tapered portion (trigger) (hereinafter, referred to as a trigger) 11a. The trigger 11a has a shape as shown in FIGS. 7 and 8 for smoothly starting crushing when an impact force is applied, and the inclination angle is appropriately set in consideration of the magnitude of the impact force and the like. . FIG. 9 shows a load-displacement curve of the FRP energy absorber 2a having the above structure. As shown in the figure, it can be seen that the change in load is small with respect to the change in displacement, and smooth deformation is performed.

FIGS. 10 and 11 show a tubular body 3 corresponding to the FRP energy absorber 2a having the shape described in FIG.
a. The tubular body 3a includes a hollow cylindrical tubular body 13a that houses an FRP energy absorber 2a therein and penetrates an inner hole 12a that covers the FRP energy absorber 2a, and flanges 15a and 16a formed on both sides thereof. Consists of The flange 15a is, for example, for fixing the tubular body 3a to the protector 4 in FIG. 1, and the flange 16a is for fixing the tubular body 3a to the bracket 5. The axial length of the tubular body 3a is substantially the same as the axial length of the FRP energy absorber 2a shown in FIG. FIG.
0, as shown in FIG. 11, a slit 10 is formed in the tubular body 13a of the tubular body 3a. In the present embodiment, the slit 10 is formed of a narrow slit 10a extending in the axial direction of the tube portion 13, and as shown in FIG.
It is formed in four equal parts along the circumferential direction of a. In addition,
The number of the slits 10a is not limited to four. The slit 10a penetrates through the inner hole 12a. This tubular body 3a is made of a hard material, for example, a metal pipe.

FIG. 12 shows a deformed state of the impact energy absorbing device 1 provided in contact with and fixed to the protector 4 or the like in the state shown in FIGS. When an impact force acts on the impact energy absorbing device 1 via the protector 4 or the front plate 6, the tubular body 3a and the FRP energy absorber 2a flex in the axial direction, and the FRP
The energy absorber 2a starts crushing from the portion of the trigger 11a. On the other hand, the tubular body 3a is deformed in a bellows shape in the related art, but the tubular body 3a of the present invention is bent and deformed outward as shown in the figure since the slit 10a is formed. Therefore, the fragments 14 of the FRP energy absorber 2a can escape outward while contacting the inner wall of the bent tubular body 3a. Therefore, the FRP energy absorber 2a can be smoothly deformed and crushed, and can sufficiently absorb impact energy. As described above, with a relatively simple structure in which the slit 10a is simply provided in the tubular body 3a, a sufficient impact energy absorbing effect can be improved.

FIGS. 13 and 14 show prismatic FRP energy absorbers 2b and 2c. FIG. 15 shows an FRP energy absorber 2d having a substantially H-shaped cross section. At one end of these, triggers 11b, 11c, 11d as shown are formed. On the other hand, FIGS. 16 and 17 show a tubular body 3b in which these FRP energy absorbers 2b, 2c and 2d are stored.
(The same applies to 3c and 3d). The tubular body 3b is made of a prismatic pipe, and includes a tubular body 13b having a prismatic inner hole 12b and flanges 15b, 16b formed on both sides thereof. FIG.
As shown in the figure, narrow slits 10b extending along the axial direction are formed at the four corners of the tubular body 13b of the tubular body 3b.
It is formed penetrating to the 2b side. By arranging the impact energy absorbing device 1 composed of the FRP energy absorbers 2b, 2c, 2d having the above structure and the tubular body 3b enclosing the same at a predetermined position in the same manner as described above, the impact of the above embodiment can be improved. Almost the same effects as the energy absorbing device 1 can be obtained.

The impact energy absorbing device is not limited to the above-mentioned embodiment, and various shapes of FRP energy absorbers and tubular bodies with slits for enclosing the FRP energy absorbers are applied. In addition, the method of attaching it to the chassis frame 7 is not limited to those shown in FIGS.
Further, the trigger of the FRP energy absorber is provided only at one end, but may be provided at both ends.

[0017]

According to the shock absorbing front underrun protector of the present invention, when an external force acts upon a collision or the like, the FRP energy absorber is smoothly crushed and the shock energy can be sufficiently absorbed, so that damage to the vehicle can be reduced. It can be reduced and also functions as a protector. In addition, the structure is simple, small, and lightweight.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a shock absorbing front underrun protector of the present invention in which a shock energy absorbing device is interposed between a bracket fixed below a chassis frame and a protector.

FIG. 2 is a top view of FIG. 1;

FIG. 3 is a front view of FIG. 1;

FIG. 4 is a cross-sectional view showing a shock absorbing front underrun protector of the present invention in which a shock energy absorbing device is interposed between a front plate and a protector fixed to a bracket fixed below a chassis frame.

FIG. 5 is an axial sectional view showing one embodiment of an FRP energy absorber of the impact energy absorbing device for the impact absorbing front underrun protector of the present invention.

FIG. 6 is a front view as viewed in the direction of arrow A in FIG. 5;

FIG. 7 is an external perspective view of the FRP energy absorber of FIG.

FIG. 8 is an enlarged sectional view showing a trigger portion of a circle B in FIG. 7;

FIG. 9 is a load-displacement diagram showing a deformed state of the FRP energy absorber shown in FIG. 5 and the like when an impact force is applied.

FIG. 10 is a plan view showing a tubular body in which the FRP energy absorber shown in FIG. 5 and the like is housed.

FIG. 11 is a sectional view taken along line CC of FIG. 10;

FIG. 12 is a schematic view showing a deformed state of the impact energy absorbing device of the present invention comprising the FRP energy absorber and the tubular body shown in FIGS.

FIG. 13 shows F in the impact energy absorbing device of the present invention.
The perspective view showing other embodiments of the RP energy absorber.

FIG. 14 shows F in the impact energy absorbing device of the present invention.
The perspective view which shows other embodiment of RP energy absorber.

FIG. 15 shows F in the impact energy absorbing device of the present invention.
The perspective view showing another embodiment of RP energy absorber.

FIG. 16 is a plan view showing one embodiment of the tubular body in which the FRP energy absorber shown in FIG. 13 and the like is housed.

FIG. 17 is a sectional view taken along line DD of FIG. 16;

FIG. 18 is a perspective view showing an arrangement structure of a conventional front underrun protector.

FIG. 19 is a configuration diagram showing a schematic structure of a conventional impact energy absorbing device having a front underrun protector function.

FIG. 20 is a schematic diagram showing a deformed state when an impact force is applied to an impact energy absorbing device including a conventional FRP energy absorber and a tubular body enclosing the same.

FIG. 21 is a schematic diagram showing a deformed state when an impact force is applied to an impact energy absorbing device including a conventional FRP energy absorber and a tubular body enclosing the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Impact energy absorption device 2 FRP energy absorber 2a FRP energy absorber 2b FRP energy absorber 2c FRP energy absorber 2d FRP energy absorber 3 Tubular body 3a Tubular body 3b Tubular body 4 Protector 5 Bracket 6 Front plate 7 Chassis frame 8 Side member 9 Cross member 10 Slit 10a Slit 10b Slit 11a Tapered portion (trigger) 11b Tapered portion (trigger) 11c Tapered portion (trigger) 11d Tapered portion (trigger) 12a Inner hole 12b Inner hole 13a Tube portion 13b Tube portion 14 Fragment 15a Flange 15b Flamb 16a Flange 16b Flange

Claims (4)

[Claims] 1. A shock absorbing front underrun protector disposed below a front surface of a chassis frame of a vehicle to prevent a vehicle having a low vehicle height from getting under a vehicle having a high vehicle height and to absorb impact energy. The shock-absorbing front underrun protector includes a protector provided along a vehicle width direction, a bracket fixed to a lower surface of the chassis frame, and an intervening portion provided between the bracket and the protector. Or an impact energy absorbing device in the form of a tube fixed to the front surface of the protector. The impact energy absorbing device includes an FRP energy absorber and a tubular body of a hard material enclosing the FRP energy absorber. A shock absorbing front underrun protector, wherein a slit communicating with the inner and outer surfaces is formed in the tubular body. 2. The FRP energy absorber comprises a hollow cylinder, the tubular body comprises a cylindrical pipe, and a tapered portion (trigger) is formed at one or both ends of the FRP energy absorber. 2. The shock absorbing front underrun protector according to claim 1, wherein a plurality of the slits are equally formed in the cylindrical pipe. 3. The FRP energy absorber has a prismatic shape, and the tubular body has a prismatic pipe having a cross-sectional shape similar to the energy absorber.
2. The shock absorbing front underrun according to claim 1, wherein a tapered portion (trigger) is formed at one or both ends of the energy absorber, and the slit is formed at a corner of the prismatic pipe. Protector. 4. The FRP energy absorber according to claim 1, wherein
The FRP energy absorber has a tapered portion (trigger) formed at one or both ends thereof, and the slit is formed at a corner of the prismatic pipe. The shock-absorbing front underrun protector according to claim 1, wherein: