JP2005271816A - Shock absorbing member for indoor of automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shock absorbing member for the indoor of an automobile improving impact energy absorbing performance without increasing member's height and having the high impact energy absorbing performance even under a low temperature environment. <P>SOLUTION: This synthetic resin made shock absorbing member absorbs a shock by ribs arranged between a cabin forming member and an interior parts of the automobile and extending in an impact load inputting direction, and the ribs are formed in a lattice-work having an intersection part 3 where the longitudinal ribs 1 and the lateral ribs 2 intersect with each other at right angles. A round part 3a is provided on the intersection part 3 so as to make it thicker than thickness of the longitudinal rib 1 and the lateral rib 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is arranged between a vehicle compartment forming member such as a pillar or a roof side rail and an interior part such as a garnish covering the inside of the vehicle compartment forming member in an automobile interior to absorb external impacts. The present invention relates to an automobile interior shock absorbing member.

  Conventionally, for example, in automobiles such as passenger cars, various types of pillars such as a roof panel, front pillars that support the roof panel, center pillars, rear pillars, and roof side rails that connect the upper sides of the various pillars are formed. A vehicle compartment forming member (body panel) is provided. And the inside of these vehicle compartment formation members is covered with interior parts, such as roof lining and pillar garnish formed with a synthetic resin etc., for the purpose of improving the designability of a vehicle interior.

  By the way, in recent years, the safety of passengers at the time of collision has been demanded at a higher level, and in particular, it is also higher for interior parts such as pillar garnishes where the head of the passenger is likely to collide. It is required to have an impact energy absorbing function.

  As countermeasures for this requirement, for example, in Patent Documents 1 to 4, an elastic material, a synthetic resin, or the like that is disposed between a vehicle compartment forming member and an interior part and absorbs an impact by a rib extending in an impact load input direction. An impact absorbing member made of In Patent Document 1, a thin-walled portion is formed at each lattice intersection of the lattice-shaped absorber body so as to assist the compression and buckling of the absorber body when it receives an impact, and finally break and absorb the impact. Thus, an impact absorbing member that can exhibit stable impact absorbing characteristics is disclosed. Patent Document 2 discloses an impact absorbing member in which a thin portion is formed at a connection portion between a beam member and a wall plate member, and the thin portion can be easily broken.

  Further, Patent Document 3 discloses an impact absorbing member in which notches are provided in the ribs so that the intersecting portions of the ribs can be independently deformed to prevent breakage of the intersecting portions of the ribs. Patent Document 4 discloses that as a material approach, a material having a large tensile elongation at break is used to prevent breakage of the intersecting portion of the ribs. However, in recent years, there has been a demand for further improvement in impact absorption characteristics, and these methods are not sufficient.

  By the way, the shock absorbing performance of the shock absorbing member is generally evaluated by the shape of a load displacement curve indicating the relationship between the load value applied at the time of impact and the amount of displacement of the shock absorbing member at that time. That is, as shown in FIG. 10, the load displacement curve shows that the load value increases as the displacement amount increases following the portion where the load suddenly rises with a small displacement amount at the initial stage of load input and the drop after the rising peak. Is composed of a portion that is in a horizontal state while increasing and decreasing, and a portion in which the load suddenly rises again with a small displacement. Here, the bottom of the shock-absorbing member occurs after the portion that is in a side-by-side state, and the point at which the load starts to rise rapidly is the crushing displacement of the shock-absorbing member.

  In this case, the energy absorption amount absorbed before the crushing displacement is represented by the area between the load displacement curve and the horizontal axis indicating the displacement amount, and the energy absorption amount increases as the area increases. Therefore, the amount of energy absorption can be increased by preventing a large drop in the load following the initial load peak and suppressing the load amplitude in a portion where the load value is in a sideways state while the load value fluctuates up and down. The energy absorption efficiency, which is an index for evaluating the impact energy absorption performance, is obtained by (energy absorption amount) / {(peak load) × (crushed displacement)} × 100, and the higher the energy absorption efficiency, the higher the impact. Energy absorption performance is evaluated to be high. Furthermore, the amount of energy absorption increases as the crushing displacement increases.

  In order to increase the impact energy absorbing performance of those impact absorbing members when the impact energy absorbing performance is insufficient or when higher performance is required, in order to increase the crushing displacement, the member (rib) It is necessary to increase the height. However, when the height of the shock absorbing member (rib) is increased, the interior of the vehicle is narrowed and visibility to the outside deteriorates.

In addition, since synthetic resin deteriorates in properties such as ductility and tensile elongation at break as the environmental temperature decreases, the impact absorbing member breaks down early in a low temperature environment and absorbs impact energy at all. There will be no or insufficient work.
JP-A-8-207578 JP-A-8-207580 JP 2002-302003 A JP 2000-170814 A

  The present invention has been made in view of the above circumstances, and can improve the impact energy absorption performance without increasing the member height, and has high impact energy absorption performance even in a low temperature environment. Providing a member is a problem to be solved.

  An automotive interior shock absorbing member of the present invention that solves the above-described problems is a synthetic resin shock absorbing member that is disposed between a vehicle interior forming member and an interior part and absorbs an impact by a rib that extends in an impact load input direction. The ribs are formed in a lattice shape having intersecting portions where the plate-shaped ribs intersect, and a radius is provided at the intersecting portions so as to be thicker than the thickness of the plate-shaped ribs. It is characterized by.

  The shock absorbing member for automobile interior according to the present invention is provided with a radius at the rib intersection, so that the energy absorption efficiency is greatly improved in a low temperature (3 ° C.) environment, and the radius is provided at the rib intersection. It has been confirmed by tests that the amount of energy absorption is improved by about 80% or more with substantially the same load and the same height of the member (rib) as compared with a conventional general shape that is not.

  This is because, when an impact load is input, the intersection of ribs is not easily broken, so in the load displacement curve, there is no large drop in load following the load peak that appears at the beginning of load input, and the amount of energy absorption increases. it is conceivable that. Also, the intersecting portion of the rib is deformed so as to be twisted when compressively deformed, but the deformation resistance is increased due to the provision of the round at the intersecting portion, and as a result of raising the load, in the load displacement curve, This is considered to be because the load amplitude in the portion where the load value fluctuates and becomes sideways is reduced, and the amount of energy absorption is increased.

  In the present invention, the radius provided at the intersecting portion of the rib is preferably formed in the range of 0.4 to 5.0 mm, more preferably in the range of 1.0 to 3.0 mm. If the size of the radius is less than 0.4 mm, it is difficult to obtain sufficient energy absorption efficiency. On the other hand, when the size of the radius exceeds 5.0 mm, the crushing displacement becomes small. Moreover, it is preferable that R is formed in the range of 0.5t to 5.0t, more preferably in the range of 1.5t to 3.0t with respect to the rib thickness t.

  On the other hand, the thickness t of the rib is preferably in the range of 0.6 to 3.0 mm. Since the impact absorbing member of the present invention is formed by resin molding, the thickness (t + Δt) on the other end side is thicker than the thickness t on one end side of the rib, because of die cutting. Moreover, when the rib is formed in a lattice shape having rectangular cells, the length of one side of the cells is preferably in the range of 10 to 50 mm, more preferably in the range of 20 to 30 mm. Moreover, it is preferable to make the length of the other side of a cell into the range of 10-100 mm, More preferably, it is the range of 20-50 mm.

  In the present invention, it is preferable that the intersecting portions of the ribs intersect at a right angle. If it does in this way, the size of the rounded arc surface provided in the intersection can be made uniform.

  Moreover, since the impact-absorbing member of this invention is a molded object obtained by shape | molding a synthetic resin material, it can form a rib in arbitrary shapes. For example, the plate-like vertical ribs extending in the vertical direction and the plate-like horizontal ribs extending in the horizontal direction may be grid-like ribs, or the ribs may be erected on the plate-like base. it can. As the synthetic resin material, for example, a thermoplastic resin such as polypropylene (PP) or ABS resin, or a thermoplastic resin composition (manufactured by Mirai Kasei Co., Ltd., product number “YV-20-2001”) is preferably used. Can do. In addition, a conventionally well-known method can be employ | adopted for a shaping | molding process, for example, injection molding, extrusion molding, etc. can be employ | adopted suitably.

  The shock absorbing member for automobile interior of the present invention is provided with a radius at the intersecting portion of the rib so as to be thicker than the thickness of the plate-like rib, so that the impact energy absorbing performance is improved without increasing the member height. And can have high impact energy absorption performance even in a low temperature environment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1
FIG. 1 is a partial plan view of a shock absorbing member for automobile interior according to the present embodiment, FIG. 2 is a partial side view of the shock absorbing member for automobile interior, and FIG. 3 is a perspective view of the shock absorbing member for automobile interior. FIG.

  The automobile interior shock absorbing member 1 of the present embodiment includes a roof side rail (not shown) that connects the upper sides of various pillars that support a roof panel of a passenger car, and an interior that covers the inside of the roof side rail and the roof panel. It is disposed between roof linings (not shown) as parts. This impact absorbing member is made of a resin molded body formed into a predetermined shape by injection molding using a synthetic resin material (product number “YV-20-2001” manufactured by Mirai Kasei Co., Ltd.).

As shown in FIG. 3, the shock absorbing member is formed in a lattice shape in which flat plate-like ribs 1 extending in the vertical direction and flat plate-like horizontal ribs 2 extending in the horizontal direction intersect at right angles. It has a plate-like rectangular shape that is long in the lateral direction. As shown in FIG. 1, the vertical ribs 1 are formed at an interval (W ₁ ) of about 26 mm, and the horizontal ribs 2 are formed at an interval (W ₂ ) of about 22 mm. A 3 mm round 3 a is provided at the intersection 3 where the vertical rib 1 and the horizontal rib 2 intersect so as to be thicker than the vertical rib 1 and the horizontal rib 2. As shown in FIG. 2, the vertical rib 1 and the horizontal rib 2 have a height (T) of about 25 mm, a thickness at one end (t ₁ ) of about 2.0 mm, and a thickness at the other end (t ₂ ) is 2.2 mm.

  As shown in FIG. 3, in the space (cell) surrounded by the longitudinal rib 1 and the lateral rib 2 in the longitudinal end portion and the substantially central portion of the impact absorbing member, the bottom plate 4 4, and the bottom plates 4 and 4 are provided with circular mounting holes 5 and 5. Further, a projecting piece 6 projecting outward in the longitudinal direction is provided at the other end in the longitudinal direction of the shock absorbing member, and a circular mounting hole 7 is also provided in the projecting piece 6.

  The impact absorbing member of the present embodiment configured as described above is attached to the interior side of the roof side rail of a passenger car with mounting bolts (not shown) inserted into the mounting holes 5, 5, 7. And between the roof side rail and roof lining. Thereby, the impact absorbing member is in a direction (height direction) in which the longitudinal rib 1 and the lateral rib 2 extend with respect to a direction (impact load input direction) in which the head of the occupant collides with the roof lining when the passenger car collides. It is arranged as follows.

  When the passenger's head collides with the roof lining due to the collision of the passenger car, the longitudinal ribs 1 and the lateral ribs 2 are plastically deformed through elastic-plastic deformation of the roof lining to absorb impact energy. At this time, since the shock absorbing member is provided with the radius 3a at the intersection 3 of the vertical rib 1 and the horizontal rib 2, it exhibits a high shock energy absorbing function not only in a normal temperature environment but also in a low temperature environment. , Absorb enough impact energy and protect the occupant. Therefore, the impact absorbing member of this embodiment has a high impact energy absorbing ability even in a low temperature environment.

  Note that the impact absorbing member of the present embodiment is disposed between the roof side rail and the roof lining, but the shape, size, etc. are appropriately changed, for example, between the center pillar and the pillar garnish. It is also possible to arrange in other parts of the passenger car.

[Test 1]
In order to confirm the excellent effect of the impact absorbing member of the present invention, as an example, a synthetic resin material (manufactured by Mirai Kasei Co., Ltd., product number “YV-20-2001”) was formed into a shape as shown in FIG. A test piece was prepared and a falling weight test was performed. As shown in FIG. 4, the test piece has a square flat plate-like base portion 50, two flat plate-like vertical ribs 51 erected on the base portion 50, and a horizontal portion erected on the base portion 50. It consists of two flat ribs 52 extending in the direction. The vertical ribs 51 and the horizontal ribs 52 intersect with each other at a right angle and are formed in a lattice shape. The base 50 has a thickness of 2.5 mm and a side length of 60 mm. The distance between the vertical rib 51 and the horizontal rib 52 (core-to-core distance: L) and the thickness (t, Δt) are as described in Table 1. As a comparative example, different test pieces were prepared only in that a radius was not provided at the intersection of the vertical rib and the horizontal rib.

  As shown in FIG. 5, the falling weight test is performed by placing test pieces on the mounting table 60 with the vertical ribs 51 and the horizontal ribs 52 facing down, and forming a hemispherical shape with aluminum on the upper surface of the base 50 of the test pieces. The spherical surface of the pressing portion 61 formed on (SR 82.5 mm) is caused to collide at a speed of 3.13 m / s, and the relationship between the load value (kN) applied at that time and the displacement amount (mm) of the test piece at that time is shown. And 20 ° C. (room temperature) and 3 ° C. (low temperature). The measurement result (load displacement curve) at 20 ° C. (normal temperature) is shown in FIG. 6, and the measurement result (load displacement curve) at 3 ° C. (low temperature) is shown in FIG. Further, the peak load, energy absorption amount and energy absorption efficiency of each test piece obtained at each environmental temperature are collectively described in Table 2. Here, the energy absorption amount is represented by the area between the load displacement curve and the horizontal axis indicating the displacement amount. Further, the energy absorption efficiency here is obtained by (energy absorption amount) / {(peak load) × (crushed displacement)} × 100.

  In the case of 20 ° C. (normal temperature), as is clear from FIG. 6 and Table 2, the results of the example were higher than the comparative example in both the energy absorption amount and the energy absorption efficiency. That is, the peak load is only a 16% increase, but the energy absorption efficiency is improved by 15%, and the amount of energy absorption is 61% higher than in the example.

  In addition, in the case of 3 ° C. (low temperature), as is clear from FIG. 7 and Table 2, in both the energy absorption amount and the energy absorption efficiency, the result of the example is significantly higher than the comparative example. Obtained. That is, the peak load is only increased by 16%, but the energy absorption efficiency is improved by 31%, so that the amount of energy absorption is 84% higher than that of the example. In particular, in the case of the comparative example, the energy absorption efficiency decreases from 50% at 20 ° C. (normal temperature) to 39% at 3 ° C. (low temperature), whereas in the case of the embodiment, 20%. The temperature rises from 65% at room temperature (normal temperature) to 70% at 3 ° C (low temperature). Therefore, in the case of the example, it can be seen that by providing a round at the intersection of the vertical rib 51 and the horizontal rib 52, it has a high impact energy absorption capability even in a low temperature (3 ° C.) environment.

  This is because, when an impact load is input, since the radius 53a is provided at the intersection 53 of the vertical rib 51 and the horizontal rib 52, the intersection 53 is not easily broken. Therefore, in the load displacement curve of FIG. It is considered that the large drop in load following the load peak appearing at the initial stage of input is smaller than that in the comparative example, and the amount of energy absorption is increased. In addition, the intersecting portion 53 of the vertical rib 51 and the lateral rib 52 is deformed so as to be twisted when compressively deformed. However, since the round portion 53a is provided at the intersecting portion 53, the deformation resistance is increased, and the load is raised. As a result, in the load displacement curve of FIG. 7, it is considered that the amplitude of the load in the portion where the load value is in a sideways state while the load value fluctuates increases and decreases and the energy absorption amount increases.

[Test 2]
The test piece of the example used in Test 1 was subjected to a test for examining the relationship between the energy absorption efficiency and the crushing displacement by variously changing the size of the radius of the intersection. The size of the radius of the crossing portion was changed to 0 mm, 2 mm, 3 mm, 5 mm, and 7 mm, and examined at ambient temperatures of 20 ° C. (normal temperature) and 3 ° C. (low temperature), respectively. The test results of the relationship between the size of the intersection and the energy absorption efficiency are shown in FIG. 8 and Table 3, and the test results of the size of the intersection and the crushing displacement are shown in FIG. 9 and Table 3.

  As is clear from FIG. 8 and Table 3, the energy absorption efficiency reaches a maximum at about 70% when the radius of the intersection is 2 to 3 mm, and then gradually decreases, and is about 60% even when the radius is 7 mm. Met. On the other hand, as is clear from FIG. 9 and Table 3, the crushing displacement decreases as the radius becomes larger. When the radius is 7 mm, the displacement is significantly reduced to about half of 2 mm. It was falling. That the crushing displacement is small is not desirable because the height of the vertical rib 51 and the horizontal rib 52 (the length of the portion extending in the load input direction) is not effectively utilized. Therefore, considering the results of energy absorption efficiency and crushing displacement, the radius of the intersection is preferably in the range of 0.4 to 5.0 mm, more preferably 1.0 to 3.0 mm. Was found to be in the range.

It is a partial top view of the shock absorption member for motor vehicle interior which concerns on embodiment of this invention. It is a partial side view of the shock absorbing member for automobile interior according to the embodiment of the present invention. 1 is a perspective view of a shock absorbing member for automobile interior according to an embodiment of the present invention. It is explanatory drawing which shows the shape and dimension of the test piece used by Test 1. FIG. 6 is an explanatory diagram showing a test method of Test 1. FIG. It is a graph which shows the load displacement curve of the Example in 20 degreeC (normal temperature) in the falling weight test of Test 1, and a comparative example. It is a graph which shows the load displacement curve of the Example in 3 degreeC (low temperature) in the falling weight test of Test 1, and a comparative example. It is a graph which shows the relationship between the magnitude | size of the cross | intersection part R in test 2, and energy absorption efficiency. It is a graph which shows the relationship between the magnitude | size of the cross | intersection part round in Test 2, and a crushing displacement. It is a graph which shows a load displacement curve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 51 ... Vertical rib 2, 52 ... Horizontal rib 3, 53 ... Crossing part 3a, 53a ... Earl 4 ... Bottom plate 5, 7 ... Mounting hole 6 ... Projection piece 50 ... Base 60 ... Mounting stand 61 ... Pressing part

Claims (5)

A shock absorbing member made of a synthetic resin that absorbs shock by a rib that is disposed between a vehicle compartment forming member and an interior part of an automobile and extends in the direction of impact load input,
The said rib is formed in the grid | lattice form which has a cross | intersection part where a plate-shaped rib cross | intersects, and the round is provided in the said cross | intersection part so that it may become thicker than the thickness of the said plate-shaped rib. Shock absorber for indoor use.   The automobile interior shock absorbing member according to claim 1 or 2, wherein the radius is formed in a range of 0.4 to 5.0 mm.   The shock absorbing member for automobile interior according to claim 1, wherein the intersecting portion of the rib intersects at a right angle.   The said rib is a shock absorption member for vehicle interiors of Claims 1-3 currently formed in the grid | lattice form where the plate-shaped vertical rib extended in a vertical direction and the plate-shaped horizontal rib extended in a horizontal direction cross | intersect.   The shock absorbing member for an automobile interior according to claim 1, wherein the rib is erected on a plate-like base.

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