JP2009023521A - Shock absorbing body for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve shock absorbing performance of a shock absorbing body for a vehicle, to generate stable deformation by fixed load from an initial stage to a final stage of displacement of the shock absorbing body, and to prevent hindrance of deformation due to overlapping of wall surfaces when the shock absorbing body is crushed and generation of lowering of maximum displacement possible amount. <P>SOLUTION: This shock absorbing body 1 has a shock absorbing rib 6 and a recessed part 8 formed on a peripheral wall 5 and constituted of a symmetrical structure. The recessed part 8 is constituted of a substantially triangular shaped welding surface 10, a pair of flat surfaces 11 for connecting the welding surface 10, a surface wall 3 and a rear surface wall 4, and a pair of other flat surfaces 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a vehicle component such as a door, door trim or body side panel, roof panel, pillar, bumper (especially bumper fascia), etc. so that when a crew member or a pedestrian collides with the vehicle component. The present invention relates to a vehicle shock absorber for absorbing the shock.

Conventionally, bumpers, bumper beams, and the like have been developed as vehicle impact absorbing members that generally have an impact buffering function, provide cushioning properties in the event of a vehicle collision, and reduce vehicle damage and impact to passengers. .
Japanese Patent No. 3561007 discloses an impact absorbing member such as a bumper beam in which a plurality of concave portions are arranged in a staggered manner on the front wall and bonded to ribs formed on the back wall.

  Furthermore, various safety standards have been strengthened for the purpose of reducing damage caused by a crew member or a pedestrian coming into contact with a vehicle structural member at the time of a vehicle collision. 2. Description of the Related Art Impact absorbing members for vehicles such as injection molding and blow molding have been developed. The impact absorbing member formed in a hollow shape by blow molding exhibits desired impact absorbing performance by deforming the wall surface constituting the impact absorbing member by the stress applied at the time of collision. That is, the impact energy at the time of collision is consumed in the process of deforming the impact absorbing member. Therefore, it is a necessary condition for this type of vehicle impact absorbing member that a predetermined amount of displacement is generated with a load within a range in which a crew member or a pedestrian who collides with the vehicle component member is not damaged.

  Furthermore, from the viewpoint of improving shock absorption, it is preferable that the target load is reached early in the initial stage of the displacement in the process of deformation of the shock absorbing member, and the target load is maintained even in the final stage of the displacement.

For this reason, the shock absorbing member formed in a hollow shape is generally provided with a shock absorbing rib having a symmetrical structure projecting into the hollow portion so as to be deformed by a constant target load from the beginning to the end of the displacement, and around the shock absorbing member. A wall is also provided with a recessed portion to adjust the shock absorption characteristics.
Specifically, a thermoplastic resin is blow-molded to have a hollow portion with a hollow double wall structure, a concave rib is formed from the front wall and the back wall, and the respective tip portions are joined and integrated, Further, Japanese Patent Application Laid-Open No. 2002-29341 and Japanese Patent Application Laid-Open No. 2006-96308 have been proposed in which a part of the side wall of the shock-absorbing member is recessed toward the hollow part to improve the shock-absorbing property as a semicircular concave rib whose side is opened It is described in.
Japanese Patent No. 3561007 JP 2002-29341 A JP 2006-96308 A

  By the way, as disclosed in Patent Document 1, it is sufficient to provide a shock absorbing member for a hollow vehicle formed by blow molding and provided with shock absorbing ribs and substantially triangular recessed portions arranged in a staggered manner. An impact buffering function can be exhibited.

  However, the substantially triangular recess is welded to the shock absorbing rib formed from the back wall, and unlike the shock absorbing member for the purpose of protecting the occupant or pedestrian, it does not have a symmetric structure. The impact absorbing member cannot be deformed by the load (see Comparative Example 1 in FIG. 8).

  Further, as disclosed in Patent Documents 2 and 3, a semicircular concave rib having a side surface opened by denting a part of the side wall of the shock absorbing member to the hollow portion side is provided, and the concave rib having the side surface opened is provided. By adjusting the distance from the open end to the opposing top wall, it is possible to set the load of the shock absorbing member, particularly in the final stage of displacement, to a predetermined value.

  However, when the distance (depth) from the open end of the semicircular concave rib (a) whose side surface is open to increase the load value to the opposite top wall is increased, the semicircular concave rib (a) becomes vertical. It is crushed in the direction and no deformation occurs at a constant load. That is, as the semicircular concave rib (a) is crushed, the wall surface of the semicircular concave rib is folded to inhibit the deformation of the shock absorbing member. For this reason, a phenomenon of so-called bottoming in which the load suddenly increases from a certain displacement amount occurs, and the substantial maximum displaceable amount as the shock absorbing member is lowered (see Comparative Example 2 and FIG. 9 in FIG. 8). . Here, the maximum displaceable amount refers to an amount or a displacement rate that can be deformed within a range that does not exceed a load value (for example, 5 kN) set as a range in which the passenger or pedestrian is not damaged. Further, the displacement rate is calculated by the ratio of the thickness when the deformation occurs to the thickness of the shock absorbing member before the deformation occurs.

  On the other hand, if the distance (depth) from the open end of the semicircular concave rib (b) whose side surface is opened to reduce the load value to the opposite top wall is reduced, the semicircular concave rib (b) is reduced. The desired reaction force cannot be generated because it bends in a letter shape, and the value of the load decreases particularly when the displacement of the shock absorbing member is 50% or more, making it difficult to increase the desired amount of shock absorption (see FIG. 8 See Comparative Example 3 and FIG.

  Therefore, the present invention aims to improve the shock absorbing performance of the shock absorber for a vehicle, and further, it causes a stable deformation by a constant load from the beginning to the end of the displacement of the shock absorber and the shock absorber is pushed. The object is to prevent the wall surface from being folded and deformed when it is crushed to prevent the maximum displacement from being reduced.

  In order to achieve the above object, the present invention provides a vehicle shock absorber according to claims 1 to 3. That is, the vehicle shock absorber according to claim 1 is installed in the vehicle component member to absorb the shock energy at the time of collision, and the shock absorber is on the side receiving the shock. A surface wall to be disposed and a back wall facing the space wall with a space therebetween, and a shock absorbing rib formed by recessing the surface wall and the back wall and joining together in the hollow portion. In addition, a plurality of concave portions are formed in the peripheral wall connecting the front wall and the back wall, and the concave portions are the bottom side, the first side, and the first side located on the parting line formed in the peripheral wall. A substantially triangular weld surface comprising two sides, a pair of flat surfaces extending from the first side to the front wall and the back wall, and another pair extending from the second side to the front wall and the back wall. of And Tanmen and is characterized in that it consists of.

  In the vehicle impact absorber according to claim 2, the first side and the second side constituting the welding surface are formed to be equal in length, and the first side and the second side corresponding to the apex angle are formed. The formed angle is in the range of 90 to 120 °.

  In the vehicle impact absorber according to claim 3, the pair of flat surfaces and the other pair of flat surfaces are formed with an inclination angle larger than 90 ° with respect to the weld surface, and the bottoms constituting the weld surface Is formed in the range of 6 to 25 mm.

  According to the vehicle shock absorber according to the present invention, the shock absorbing rib is provided between the front wall disposed on the shock receiving side and the opposite back wall, the concave wall is provided on the peripheral wall, and the concave wall is further provided. By forming the welded surface arranged in the part into a substantially triangular shape and forming the recessed part with a flat surface extending from the welded surface to the front and back walls, the recessed part is crushed by a constant load from the initial stage to the final stage of deformation. Thus, the effect of improving the shock absorbing performance by securing a sufficient amount of displacement can be obtained.

  1 to 4, reference numeral 1 denotes a part of a vehicle shock absorber according to an embodiment of the present invention. This vehicle impact absorber 1 is formed by blow molding a thermoplastic plastic into a hollow shape, 2 is a hollow portion, 3 is a front wall, 4 is a back wall, and 5 is a peripheral wall. In the present embodiment, the vehicle impact absorber 1 includes a front wall 3 and a back wall 4 that are opposed to each other with a space therebetween via a hollow portion 2, and a peripheral wall 5 that connects the front wall 3 and the back wall 4. It is formed in a scale.

  Since the vehicle shock absorber 1 is designed in a shape that matches the internal space of the vehicle component, the front wall 3 and the back wall 4 are not necessarily flat, and the distance between the front wall 3 and the back wall 4 is not constant. In general, there are some places where the width of the hollow portion 2 is wide or narrow depending on the part. However, since the shock absorption amount of the shock absorber 1 depends on the displaceable amount, it is preferable that the space between the front wall 3 and the back wall 4 is maximized within the range allowed by the internal space of the vehicle component. Specifically, the surface wall 3 and the back wall 4 are generally formed with an interval of 30 to 110 mm through the hollow portion 2, and the average thickness is within a range of 0.3 mm to 6.0 mm, particularly preferably. Is adjusted in the range of 0.5 to 3.0 mm.

  Further, the vehicle impact absorber 1 is installed so that the surface wall 3 is disposed on the vehicle component side. Preferably, at least a part of the surface wall 3 is placed in contact with a vehicle component, and is fixed by screwing or the like via a fixing piece (not shown) provided on the vehicle shock absorber 1. As a result, when a pedestrian's leg or the like comes into contact with an exterior vehicle component such as a bumper fascia at the time of a vehicle collision, the passenger's head or waist, etc. Can be absorbed by the vehicle impact absorber 1 being crushed. In addition, the aspect which mounted | wore each vehicle structural member with the shock absorber 1 for vehicles in FIG. 14 is a bumper fascia, 15 is a bumper beam, 16 is a roof panel, 17 is a passenger's head, 18 is a door trim, and 19 is a door.

Further, the vehicle shock absorber 1 has a plurality of shock absorbing ribs 6 in which a part of the front surface wall 3 and the back surface wall 4 arranged opposite to each other is recessed toward the other wall. The absorption ribs 6 are joined together by welding their tip portions at intermediate positions between the front wall 3 and the back wall 4 and have a symmetrical structure at the joint.

  In the present embodiment, the shock absorbing rib 6 is formed in a groove shape arranged along the longitudinal direction of the vehicle shock absorber 1, and the groove is directed toward the back wall 4 facing the front surface wall 3. The grooved rib 6a is formed into one groove-like rib 6a, and the back wall 4 is recessed into a grooved shape toward the opposite surface wall 3 to form the other grooved rib 6b. Thus, the welded portion 7 is formed by joining in the hollow portion 2. The welded portion 7 is disposed in the center between the front surface wall 3 and the back wall 4, and the one grooved rib 6 a and the other grooved rib 6 b have a symmetrical structure in the welded portion 7.

  Thereby, the shock absorbing rib 6 composed of one groove-like rib 6a and the other groove-like rib 6b is deformed while maintaining a constant reaction force against the stress at the time of collision, and is collapsed. Energy corresponding to the amount of displacement is consumed to absorb the impact. In the present embodiment, the shock absorbing rib 6 is a pair of concave ribs. However, the shape is appropriately selected from, for example, a cylindrical shape, a prismatic shape, a V-shaped groove shape or the like as long as the above effect is achieved. Is possible.

  Furthermore, a plurality of concave portions 8 are formed in the peripheral wall 5 constituting the vehicle shock absorber 1, and these concave portions 8 are formed on the bottom side 10a, the first side 10b and the first side 10b located on the parting line 9. The substantially triangular welding surface 10 having two sides 10c has a symmetric structure.

  In the present embodiment, the recessed portions 8 are arranged at equal intervals along the longitudinal direction of the peripheral wall 5 of the vehicle shock absorber 1, and are formed from a substantially triangular weld surface 10 and a first side 10b. It consists of a pair of flat surfaces 11 extending to the surface wall 3 and the back wall 4 and another pair of flat surfaces 12 extending from the second side 10 c to the surface wall 3 and the back wall 4. The first side 10b and the second side 10c are formed to have the same length, and the pair of flat surfaces 11 and the other pair of flat surfaces 12 are positions corresponding to the apex angle of the substantially triangular welding surface 10. The ridge line 13 is formed at a position where the surfaces intersect each other. The concave portion 8 is formed as one triangular prism-shaped concave portion 8a in which the boundary portion between the front wall 3 and the peripheral wall 5 is recessed to open the side surface, and the boundary portion between the back wall 4 and the peripheral wall 5 is recessed to open the side surface. The other triangular prism-shaped concave portion 8b is formed, and the concave portions are welded to form the welding surface 10, thereby forming a symmetrical structure.

  Thereby, the recessed part 8 which consists of one recessed part 8a and the other recessed part 8b cooperates with the said shock absorption rib 6, and absorbs the impact at the time of a collision. Here, it is considered that the recessed portion 8 formed in the peripheral wall 5 mainly affects the final stage of displacement of the vehicle shock absorber 1 in shock absorption. That is, in the process in which the shock absorbing member is crushed and displaced, first, the vicinity of the center is crushed and deformed by the stress at the time of collision. After that, it is considered that the displacement progresses and the influence of the load appears near the surrounding wall.

  In the recessed portion 8 according to the present embodiment, the wall surface of the recessed portion 8 is formed by a substantially triangular welding surface 10 and a pair and other pairs of flat surfaces 11 and 12. So that the so-called bottoming phenomenon is less likely to occur, and it is further bent into a square shape, and in particular at the end of displacement with a displacement rate of 60% or more, there is no sudden drop in load (see FIGS. 4 and 4). See Example 8).

  The aspect of the recessed portion 8 formed in the vehicle impact absorber 1 according to the present invention can be changed as appropriate for the purpose of adjusting the impact absorption characteristics within the range in which the above effect is achieved. Specifically, the angle formed by the first side 10b and the second side 10c corresponding to the apex angle of the welding surface 10 is adjusted in the range of 90 to 120 °, and the distance from the bottom side of the welding surface 10 to the apex angle. (Depth) is adjusted in the range of 3 to 7 mm. Increasing the angle formed above or decreasing the distance from the base to the apex angle can suppress the increase in load at the end of displacement, increasing the maximum amount of displacement of the shock absorber for vehicles and increasing the amount of shock absorption. Can be improved. Further, the length of the base is adjusted in the range of 6 to 25 mm depending on the angle and depth formed by the welding surface 10.

  Further, the ridge line 13 formed at a position where the pair of flat surfaces 11 and the other pair of flat surfaces 12 intersect is a linear portion formed by contact of the flat surfaces with curved surfaces of 2R or less. . The ridge line 13 is formed with a gradient in the range of 3 to 8 ° from the perpendicular to the welding surface 10.

  In the present embodiment, the parting line 9 is formed over the entire circumference of the peripheral wall 5 at the center between the front surface wall 3 and the rear wall 4. By request, the portion not corresponding to the recessed portion 8 can be formed at a position deviated from the center between the front wall 3 and the back wall 4 toward the front wall or the back wall.

  The vehicle impact absorber 1 according to the present invention can be molded by a known method such as blow molding or sheet blow molding using a thermoplastic resin. Thermoplastic resins include polyolefin resins such as polyethylene and polypropylene, styrene resins such as polystyrene, high impact polystyrene (HIPS) and ABS resins, polyester resins such as polyethylene terephthalate, polyamide, polyphenylene ether resins, and more. These blends or polymer alloys can be suitably used.

  FIG. 8 is a graph obtained as a result of applying a blow molded vehicle shock absorber as described below to a collision tester. In the examples and comparative examples 1 to 3, the shape of the recessed portion (concave rib) formed on the peripheral wall was changed. The dimensions of the vehicle impact absorber were 300 mm × 45 mm × 100 mm (W × D × H), and the average wall thickness was 1.3 mm. Polypropylene “AD571” (flexural modulus 1050 MPa) manufactured by Sumitomo Mitsui Chemicals, Inc. was used as the material constituting the vehicle impact absorber. This collision tester was a collision tester manufactured by Hodogaya Giken Co., Ltd., and collided with a collider having a mass of 20 kg and a tip of φ75 mm at a speed of 20 km / hour.

  As is apparent from FIG. 8, when the target load is 5 kN from the viewpoint of preventing the passenger or pedestrian from being damaged, the comparative example has a smaller effective shock absorption than the example. It was. The shock absorption amount is the area of the portion surrounded by the curve below the curve and the horizontal axis (excluding the range exceeding the target load).

  Comparative Example 1 is based on the disclosure of Example 1 of a blow molded vehicle impact absorber described in Patent Document 1. In Comparative Example 1, the target load is exceeded at a displacement rate of 50%, and an effective shock absorption amount cannot be obtained until the end of the displacement. In addition, the amount of absorption is small because the inclination is gentle even in the initial stage of displacement. Further, Comparative Example 2 is based on a vehicle shock absorber having a semicircular concave rib with an increased depth from the open end to the opposing top wall. In Comparative Example 2, the value of the load increases rapidly from the vicinity of the displacement rate of 60%, which exceeds the target load. For this reason, an effective shock absorption amount cannot be obtained until the end of the displacement. Furthermore, Comparative Example 3 is based on a vehicle shock absorber having a semicircular concave rib with a reduced depth from the open end to the opposing top wall. In Comparative Example 3, although the target load does not exceed the displacement rate near 80%, the value of the load sharply decreases at the end of the displacement.

  On the other hand, in the embodiment, the target load is reached at the initial stage of the displacement, and thereafter the target load is maintained until the displacement rate is close to 80%. It was.

  The vehicle shock absorber according to the present invention is installed in a vehicle component such as a door of an automobile, a door trim or a body side panel, a roof panel, a pillar, and a bumper fascia, and the shock absorption of those portions is markedly increased. It can be enhanced and greatly contributes to improving the safety of automobiles.

FIG. 1 is a partially cutaway perspective view showing a vehicle shock absorber according to an embodiment of the present invention. It is an enlarged view of the principal part same as the above. It is AA sectional drawing of FIG. It is sectional drawing which shows the process in which the impact absorber for vehicles which concerns on one embodiment of this invention is crushed by the impact. It is a figure which shows the structure which mounted | wore the bumper fascia which is a vehicle structural member with the shock absorber for vehicles which concerns on this invention. It is a figure which shows the structure where the shock absorber for vehicles which concerns on this invention was mounted | worn in the roof panel which is a vehicle structural member. It is a figure which shows the structure which mounted | wore the door trim which is a vehicle structural member with the vehicle impact absorber which concerns on this invention. It is a graph which shows the relationship between the load and displacement rate of the impact absorber for vehicles which concerns on one embodiment of this invention. It is sectional drawing which shows the process in which the impact absorber for vehicles which concerns on the comparative example 2 is crushed by an impact. It is sectional drawing which shows the process in which the impact absorber for vehicles which concerns on the comparative example 3 is crushed by an impact.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle shock absorber 2 Hollow part 3 Front wall 4 Back wall 5 Peripheral wall 6 Shock absorption rib 6a One groove-shaped rib 6b Other groove-shaped rib 7 Welding part 8 Recessed part 9 Parting line 10 Welding surface 10a Bottom 10b First side 10c Second side 11 Pair of flat surfaces 12 Other pair of flat surfaces 13 Edge line 14 Bumper fascia 15 Bumper beam 16 Roof panel 17 Passenger's head 18 Door trim 19 Door (a), (b) Semi-circular Concave rib

Claims (3)

In a vehicle shock absorber for absorbing shock energy at the time of collision by being installed in a vehicle component member,
The shock absorber has a front wall disposed on the side receiving the shock and a back wall facing the front wall with a space therebetween through a hollow portion,
A shock absorbing rib formed by recessing the front wall and the back wall and joining together in the hollow portion;
Furthermore, a plurality of concave portions are formed in the peripheral wall connecting the front wall and the back wall, and the concave portions are a bottom side, a first side and a second side located on a parting line formed in the peripheral wall. A substantially triangular welding surface comprising: a pair of flat surfaces extending from the first side to the surface wall and the back surface wall; and another pair of flat surfaces extending from the second side to the surface wall and the back surface wall. Surface,
A shock absorber for a vehicle comprising: The first side and the second side constituting the welding surface are formed to have an equal length,
2. The vehicle impact absorber according to claim 1, wherein an angle formed by the first side and the second side corresponding to the apex angle is in a range of 90 to 120 [deg.]. The pair of flat surfaces and the other pair of flat surfaces are formed with an inclination angle larger than 90 ° with respect to the welding surface,
2. The vehicle impact absorber according to claim 1, wherein a length of a bottom side constituting the welding surface is formed in a range of 6 to 25 mm.

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