JP4181630B2 - Shock absorber for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a vehicle component such as a door or a body side panel so that an occupant collides with the inner wall of the vehicle component , or an external impact such as a collision with another vehicle. it relates a vehicle shock absorber for absorbing an impact applied from.
[0002]
[Prior art]
As a shock absorber for this type of vehicle, a thermoplastic resin is blow-molded to have a hollow portion with a hollow double wall structure, and concave ribs are formed from the front and back walls to join the tip portions of each other. And those that are intended to improve impact absorption are described in JP-A-2002-187508. Moreover, what consists of a polypropylene component and a copolymer component of propylene and ethylene as a polypropylene resin composition is described in Unexamined-Japanese-Patent No. 2002-201322.
[0003]
[Problems to be solved by the invention]
By the way, in the vehicle shock absorber shown in the above-mentioned Japanese Patent Application Laid-Open No. 2002-187508, the structure is devised to improve shock absorption, such as a connecting rib that integrally connects a plurality of concave ribs. However, it has been pointed out that sufficient shock absorption cannot be obtained particularly at low temperatures.
[0004]
Accordingly, the present invention is integrally molded by blow molding, and the shock absorbing body formed by a concave ribs, flexural modulus for the polyolefin resin which is a base resin is 2000 kg / cm ² or less of resin It is an object of the present invention to provide a shock absorber for a vehicle which is excellent in impact absorbability at a low temperature of minus 30 ° C. or less , by comprising a thermoplastic resin containing 3 to 20 parts by weight of the above.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a vehicle shock absorber according to claim 1 of the present invention is a vehicle shock absorber provided in a vehicle component, wherein the shock absorber is integrally formed by blow molding. A main body made of a thermoplastic resin and having a hollow portion, and a concave rib forming a pair in which the one surface and the other surface of the main body facing each other are recessed in the facing direction and the tip portions are joined to each other to form a result, the shock absorber, that the flexural modulus for the polyolefin resin as a base resin is composed of a thermoplastic resin containing 3 to 20 parts by weight of 2000 kg / cm ² or less of resin It is a feature.
[0006]
According to a second aspect of the present invention, there is provided a vehicle impact absorber according to a second aspect of the present invention, wherein the impact absorber is made of a thermoplastic resin integrally formed by blow molding. a body having a hollow portion, or by depressing toward another surface direction joining the tip to the other surface opposing the one surface of the main body, or towards the other surface to the one surface opposite directions recessed so it forms a concave rib is joined to the distal end portion on one side and Te, shock absorber, flexural modulus for the polyolefin resin as a base resin a 2000 kg / cm ² or less of resin It is composed of a thermoplastic resin containing 3 to 20 parts by weight .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
1 is a perspective view of a shock absorber for a vehicle according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view taken along the line AA of FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing a mode in which a vehicle shock absorber according to the present invention is installed in a rear pillar of an automobile, and FIG. 5 is a cross-sectional view showing a mode in which the vehicle shock absorber according to the present invention is installed. FIG. 6 is a graph showing the results of measuring the displacement (change in compression strain) with respect to the compression load by compressing the vehicle impact absorber 1 obtained by blow molding with a tensile tester. is there.
[0008]
1 and 2, reference numeral 1 denotes a vehicle shock absorber. The vehicle shock absorber for 1 each opposing direction of both one surface 4 and the other surface 5 facing each other of the main body 3 having a hollow portion 2 which is made of thermoplastic resin are integrally molded by blow molding A large number of pairs of concave ribs 6, 7 are formed so as to be recessed toward each other, and the tip portions of the concave ribs 6, 7 are in contact with each other to form a joint 8.
[0009]
Or vehicle impact absorbing body 1 according to the present invention, a concave ribs, is bonded to the other surface 5 of the tip by depressing toward the one surface 4 facing each other of the main body 3 to the other side 5 direction, or it can be the other surface 5 by depressing toward one surface four directions a structure obtained by bonding the tip portion on one surface 4. This configuration is not shown.
[0010]
Furthermore, the vehicle impact absorber 1 according to the present invention is made of a thermoplastic resin in which 3 to 20 parts by weight of a soft resin having a flexural modulus of 2000 kg / cm ² or less is blended with a polyolefin resin. As a result, the shock absorption at a low temperature of −30 ° C. or less is improved due to the synergistic effect of adding the concave rib provided on the shock absorber and the soft resin.
[0011]
The vehicle impact absorber 1 obtained by blow molding was compressed by a tensile tester, and the displacement (change in compression strain) with respect to the compression load was measured. The result is shown in FIG. The curve (a) shown in the graph of FIG. 6 shows the displacement with respect to the compressive load of the vehicle shock absorber 1 having a concave rib to which no soft resin is added at normal temperature. The displacement of the shock absorber exceeds 15 mm. It is clear that even at times, the impact is satisfactorily absorbed by supporting a high load without lowering the compression load. On the other hand, the curve (c) shown in the graph shows the displacement with respect to the compression load of the vehicle shock absorber 1 having a concave rib to which no soft resin is added at minus 30 ° C., and the displacement of the shock absorber is 10 mm. It is clear that the compressive load decreases from around the point where good shock absorption is not obtained. In other words, in the vehicle impact absorber 1 to which no soft resin is added at low temperatures, embrittlement failure occurs in the concave ribs, and the required impact absorbability cannot be obtained due to the formation of cracks.
[0012]
Therefore, by adding a soft resin, the impact absorbability can be improved even at low temperatures as shown by the curve (b) shown in the graph. The curve (b) shown in the graph shows the displacement with respect to the compressive load at minus 30 ° C. when the soft resin is added, and the displacement of the shock absorber is reduced by adding the soft resin compared to the curve (c). A decrease in compressive load from around 10 mm is suppressed, and good shock absorption is exhibited. In other words, heat in which the impact absorber 1 for a vehicle having concave ribs is made of a polyolefin resin such as polypropylene as a base resin and 3 to 20 parts by weight of an olefin elastomer soft resin having a flexural modulus of 2000 kg / cm ² or less is blended. By using the plastic resin, the temperature dependence can be suppressed, and the impact absorber 1 for the vehicle is not cured even at a low temperature of minus 30 ° C., and the occurrence of embrittlement failure against the impact is prevented. A suitable shock absorption can be obtained. Further, since the impact absorber for vehicles is required to have an impact absorbability at minus 30 ° C., the added soft resin is required to have a glass transition temperature or an embrittlement temperature of minus 30 ° C. or less.
[0013]
As a resin having a flexural modulus of 2000 kg / cm ² or less, it is necessary to have good mixing with a polyolefin resin as a base resin, and an olefin elastomer, a styrene elastomer, a low density polyethylene, a straight chain Low density polyethylene, ultra-low density polyethylene, and linear ultra-low density polyethylene are suitable, and particularly good impact is obtained by blending 3 to 20 parts by weight of olefin elastomer to polyolefin resin as a base resin. Absorbability is obtained.
[0014]
Examples of olefin elastomers include ethylene-propylene copolymer rubber, ethylene-butene copolymer rubber, propylene-butene copolymer rubber, butadiene-styrene copolymer rubber hydrogenated products, and styrene elastomers such as styrene. A butadiene block copolymer, a styrene-butadiene-styrene block copolymer, a styrene-isoprene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated product thereof, and the like are preferably used. These elastomers have good mixing properties with polyolefin resins.
[0015]
The vehicle impact absorber 1 according to the present invention is installed in a door of a car, a body side panel, a roof panel, a pillar, a bumper, and the like. FIG. 3 shows an example in which the vehicle shock absorber 1 according to the present invention is installed in the door trim 10 of the door 9, FIG. 4 in the rear pillar 11 of the automobile, and FIG. 5 in the rear bumper 12, respectively. In FIG. 4, A shows the head of the passenger.
[0016]
【The invention's effect】
According to the present invention, are integrally molded by blow molding, and the shock absorbing body formed by a concave ribs, flexural modulus for the polyolefin resin which is a base resin is 2000 kg / cm ² or less of resin By using a thermoplastic resin blended with 3 to 20 parts by weight of a vehicle, it is possible to obtain a vehicle impact absorber that is particularly excellent in impact absorption at low temperatures of minus 30 ° C. or lower.
[Brief description of the drawings]
FIG. 1 is a perspective view of a vehicle shock absorber according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view taken along line AA in FIG.
FIG. 3 is a cross-sectional view showing a mode in which a vehicle shock absorber according to the present invention is installed in a door of an automobile.
FIG. 4 is a cross-sectional view showing a mode in which a vehicle shock absorber according to the present invention is installed in a rear pillar of an automobile.
FIG. 5 is a rear view of a rear bumper provided with a vehicle shock absorber according to the present invention.
FIG. 6 is a graph showing a result of measuring a displacement (change in compressive strain) with respect to a compressive load by compressing a vehicle impact absorber 1 obtained by blow molding using a tensile tester.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle shock absorber 2 Hollow part 3 Main body 4 Contact surface 5 Support surface 6,7 Concave rib 8 Joint part 9 Door 10 Door trim 11 Rear pillar 12 Rear bumper A Head

Claims (2)

In a shock absorber for a vehicle installed in a vehicle component,
Shock absorber includes a body having a hollow portion which is made of thermoplastic resin are integrally molded by blow molding, the one surface and the other surface opposite to each other of the body by depressing towards each to the opposite direction Forming a pair of concave ribs joined to each other's tip,
Shock absorber, shock vehicle, characterized in that the flexural modulus for the polyolefin resin as a base resin is composed of a thermoplastic resin containing 3 to 20 parts by weight of 2000 kg / cm ² or less of resin Absorber. In a shock absorber for a vehicle installed in a vehicle component,
The shock absorber is made of a thermoplastic resin integrally formed by blow molding and has a hollow body, and one surface of the main body is recessed toward the other surface facing the other, and the tip portion is made the other. if is bonded to the surface, or recessed so it forms a concave rib is joined to the distal end portion on one side and toward the other one surface opposite directions surfaces,
Shock absorber, shock vehicle, characterized in that the flexural modulus for the polyolefin resin as a base resin is composed of a thermoplastic resin containing 3 to 20 parts by weight of 2000 kg / cm ² or less of resin Absorber.

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