JP3301732B2 - Mounting structure of pillar garnish with built-in airbag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pillar garnish mounted on a front pillar portion of an automobile, and more particularly to a mounting structure of a pillar garnish incorporating an airbag.

[0002]

2. Description of the Related Art Conventionally, airbag devices have been provided on the front and side surfaces of a vehicle cabin in order to safely protect an occupant of an automobile from the impact of a collision. In particular, in order to prevent the occupant's head from colliding with the side glass or the like in response to an impact from the side of the automobile, in recent years, a pillar garnish 60 with an airbag A containing an airbag A as shown in FIG. Attachment to the pillar portion 75 has been performed. In the pillar garnish 60 with a built-in airbag, the airbag A is inflated as shown in FIG. 13 by the gas generated from the inflator I provided near the instrument panel P at the time of a vehicle collision, and is pushed toward the passenger compartment. From the gap between the bent side edge portion 61 of the pillar garnish 60 and the vehicle body pillar portion 75, the pillar garnish 60 swells and expands into the vehicle interior as shown by a chain line Bo in FIG. 12.

[0003] Pillar garnish 6 with built-in airbag
0, when the airbag A is inflated and deployed, an extremely large pressing force is applied to the pillar garnish 60 in the vehicle interior direction.
5 must be mounted so that it does not fall off.

Conventionally, as a mounting structure for preventing the pillar garnish from scattering, a bolt insertion hole is formed through the upper and lower middle portion of the pillar garnish, and a bolt inserted through the bolt insertion hole is fastened and fixed to a vehicle body pillar portion. is there. The lower end of the pillar garnish is inserted and fixed in a hole or the like formed in the instrument panel P.

However, in the case of mounting with the bolts, since the pillar garnish is completely fixed to the vehicle body pillar portion at the bolt fixing portion, an extremely large stress is generated when the side edge portion of the pillar garnish is pushed and bent due to the inflation of the airbag. Attached near the bolt fixing part, conventional ABS resin (acrylonitrile butadiene styrene resin) or PPF
A pillar garnish made of (inorganic-added propylene) resin cannot withstand the stress and may be cracked. In addition, in the mounting structure using the bolts, the bolt garnish must be able to be bolted from the design surface (inside the vehicle) of the pillar garnish, so that the head of the bolt appears on the design surface side of the pillar garnish. And, as it is, the beauty is impaired. In order to solve this problem, a blind cover is fitted into the bolt insertion hole from the design side of the pillar garnish.

[0006] As a solution to the problem of the cover, as shown in FIG.
0, a seat portion 62 is integrally formed on the back of the predetermined position, and a head 66 of a rod-shaped fixing bracket 65 such as a bolt is embedded in the seat portion 62, and the other end 69 of the rod-shaped fixing bracket 65 is connected to a vehicle body pillar. A structure that inserts and locks into a locking hole 76 formed in the inner panel 71 of the portion 75 is conceivable. The rod-shaped fixing bracket 65
Is made of metal, and one end of the shaft 67 is connected to a large-diameter head 66.
The locking portion 68 is provided on the other end 69 of the shaft portion 67, and the illustrated bar-shaped fixing bracket 65 is composed of a bolt and a nut as the locking portion 68. In the figure, reference numeral F denotes a windshield, 77 denotes an opening trim, 78 denotes a glass run channel, and 79 denotes a body frame.

However, when the mounting structure shown in FIG. 14 is adopted, the thickness of the pillar garnish 60 is locally changed by the presence of the side surface 63 of the seat portion 62.
As shown in FIG. 5, sink marks 64 easily occur on the design surface. As a method for preventing the generation of the sink marks 64, a side surface 63 of the seat portion 62 is provided.
It is conceivable that the thickness K2 is smaller than the thickness K1 outside the seat portion (preferably, K2 is 1/2 of K1). However, if the thickness K2 of the side surface 63 of the seat portion 62 is reduced until the sink marks 64 can be prevented, the side surface 63 of the seat portion 62 which becomes a hinge portion when the pillar garnish 60 is pushed and bent by the inflation of the airbag A as shown in FIG. Cracks are generated in the base 61a due to stress concentration.

Further, a pillar garnish 6 having this structure
In the case where the head 66 of the rod-shaped fixing bracket 65 made of a bolt or the like is directly insert-molded as shown in FIG. 0, the resin thickness of the pillar garnish above the head 66 by embedding the head 66, that is, the seat 62 When the resin thickness of the pillar garnish in the portion surrounded by the side surface 63 becomes uneven,
It has been found that sink marks easily occur on the design surface of the pillar garnish 60. However, in a normal pillar garnish, a portion fixed with the bolt or the like is often formed into a curved surface from the viewpoint of design. On the other hand, a commonly used rod-shaped fixing bracket 65 such as a bolt has a head 66. Since it is a flat surface, it is difficult to make the distance between the surface of the head 66 of the rod-shaped fixing bracket 65 and the design surface of the pillar garnish 60, that is, the resin thickness of the pillar garnish in that portion, difficult, and the occurrence of the sink occurs. It was inevitable. Further, in order to make the resin thickness of the pillar garnish surrounded by the side surface 63 of the seat part constant, it is possible to form the surface of the head 66 of the rod-shaped fixing bracket 65 in a shape corresponding to the design surface shape of the pillar garnish 60, A special rod-shaped fixing bracket is required, which increases the cost, which is not preferable.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a pillar garnish having a good appearance without sink marks, a simple structure, and a pillar garnish when the airbag is inflated and deployed. It is intended to provide a mounting structure for a pillar garnish with a built-in airbag which is unlikely to be detached or broken.

[0010]

That is, according to the first aspect of the present invention, there is provided a synthetic resin pillar garnish having a seat having a large diameter head at one end and a seat having a large diameter head. The head of the rod-shaped fixing bracket provided with a locking portion is buried at the time of injection molding of a pillar garnish, and the locking portion of the rod-shaped fixing bracket is inserted and locked in a locking hole of a vehicle body pillar portion, thereby forming the pillar garnish. When the pillar garnish is pressed and bent due to the inflation of the airbag accommodated on the back side of the pillar garnish, the pillar garnish has an airbag built-in pillar garnish in which the pillar garnish is prevented from coming off by engagement of the rod-shaped fixing bracket and the locking hole. In the mounting structure, a pillar garnish in which a head of the rod-shaped fixing bracket is covered with a coating layer of a synthetic resin and a surface of the coating layer is surrounded by a side surface of the seat portion. By making it equal to the surface shape, the thickness of the pillar garnish of the portion surrounded by the side surface of the seat is made substantially uniform, and the resin constituting the pillar garnish is made of a polyolefin-based thermoplastic elastomer, and the coating layer is formed. A peak area S1 indicating the heat of fusion of the polypropylene, wherein the constituent resin contains at least 40 wt% of polypropylene and represented by differential scanning calorimetry (DSC), and a peak indicating the heat of fusion of a component melting at a lower temperature than the polypropylene. The present invention relates to a mounting structure of a pillar garnish with a built-in airbag, characterized in that the area S2 is made of a polyolefin-based thermoplastic elastomer in which S2 / S1 <1/2.

According to a second aspect of the present invention, there is provided a mounting structure of a pillar garnish with a built-in airbag according to the first aspect, wherein reinforcing ribs are formed radially at least on the outer side surfaces of the seat portion on the airbag deployment side. According to.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing the interior of a vehicle to which a pillar garnish is mounted by the mounting structure of the present invention, FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 1, FIG. 5 is a partial perspective view showing a state where the pillar garnish of FIG. 1 is attached, FIG. 6 is a cross-sectional view showing an example without a seat bottom,
FIG. 7 is a perspective view showing another example of the rod-shaped fixing bracket, FIG. 8 is a sectional view taken along line 2-2 of FIG.
FIG. 10 is a sectional view showing the vicinity of the rod-shaped fixing bracket of FIG. 8, and FIG.
, And FIG. 11 is a DSC graph of the resin constituting the coating layer.

As shown in FIGS. 1 to 3, a pillar garnish 10 according to the present invention is attached to a vehicle body pillar portion 20 above an instrument panel P of an automobile with an airbag A folded on the back side. The inside of the cabin of the unit 20 is covered. In the event of a car collision, gas is pressed into the airbag A by the operation of the inflator I installed near the instrument panel P, and the airbag A inflates sequentially from the instrument panel P side (the lower side of the pillar garnish 10). , The rear side 11 of the pillar garnish 10 (that is, the side glass G
Side airbag A is bent inside the side glass G from the gap between the side edge 12 of the pillar garnish 10 and the vehicle body pillar portion 20, and the airbag A is deployed inside the side glass G. The part is protected.

The pillar garnish 10 is formed by injection molding, and is formed of a synthetic resin cover body having a required length and a curved cross-sectional shape bulging into the vehicle interior, and having a width corresponding to the vehicle longitudinal direction. Approximately center position 13 in the direction
The rear surface of the vehicle rear side 11 (side glass G side) is a portion for accommodating the airbag A, and the vehicle front side 14
The back surface (that is, the front glass F side) is a portion for accommodating the power cord C and the like from the engine room.
Reference numeral 22 denotes an opening trim, and reference numeral 23 denotes a glass run channel.

The resin constituting the pillar garnish 10 is an appropriate TPO (polyolefin-based thermoplastic elastomer). However, the pillar garnish 10
Is usually a long part of 50 cm or more, so it is easy for dimensional changes to occur due to thermal expansion due to high vehicle interior temperature in summer, and at high temperatures, the strength near the mounting part to the pillar part due to softening of the resin There is a tendency to decrease. Further, in consideration of the place of use and the season of the vehicle, it is necessary to prevent the pillar garnish from being broken or scattered when the airbag is inflated in a range from a low temperature (−35 ° C.) to a high temperature (90 ° C.). It is necessary to make the resin appropriate hardness (softness) from the viewpoint of workability in mounting to the vehicle body pillar portion. From this point, as the resin constituting the pillar garnish, Izod impact strength (-35 ° C, JIS K
7110) is greater than 20 kg · cm / cm, and the flexural modulus (JIS K 7203) is 4,500 kg / cm.
Larger than ² , heat-resistant deformation temperature (4.6 kg load, JIS
K 7207) is greater than 90 ° C. and the coefficient of linear expansion (−35 ° C.)
~ 90 ° C, ASTM D 696) is 10 ° C · cm / c
TPOs smaller than m are particularly preferred.

In the pillar garnish 10 of this embodiment, the lower end is inserted and fixed in a hole (not shown) formed in the instrument panel P, and the pillar garnish 10 has an intermediate portion.
Mounting portions 15, 15, 16, 1 along the longitudinal direction of
6 attaches to the vehicle body pillar section 20. The intermediate mounting portions 15, 15, 16, and 16 in this example include a mounting portion 15 for preventing the pillar garnish from coming off when the airbag A is inflated and a mounting portion 16 for preventing rattling in a normal state. The attachment portions 15 for preventing disengagement and the attachment portions 16 for preventing backlash are arranged alternately in this order.

The detachment-preventing mounting portion 15 has a seat 17 protruding from the back surface of the pillar garnish 10, and a head 31 of a rod-shaped fixing bracket 30 is embedded and fixed in the seat 17. The seat 17 has a side surface 17a and a bottom surface 17b, and the head 31 of the rod-shaped fixing bracket 30 is embedded in a portion surrounded by the side surface 17a and the bottom surface 17b. It should be noted that the bottom surface 17b is covered by the coating layer 40 described later with the pillar garnish 10.
When it is firmly fused to the back surface or the seat side surface 17a, the thickness may be zero, that is, it may not exist, as in the example shown in FIG.

The thickness T2 of the side surface 17a and the thickness T3 of the bottom surface 17b of the seat 17 are related to the thickness T1 of the pillar garnish 10 outside the seat 17 by T1.
>T2> T3 ≧ 0 is preferred. With such a thickness relationship, the rigidity of the side surface 17a of the seat portion 17 decreases, and when the pillar garnish 10 is pushed and bent toward the vehicle interior,
Stress concentration is reduced on the base 18 of the side surface 17a of the seat 17 serving as a hinge, and the seat 17 is inflated when the airbag A is inflated and deployed.
Cracks are less likely to occur at the base 18 of the side surface 17a.

The rod-shaped fixture 30 has a large diameter head 31 at one end of a shaft portion 32 and a locking portion 3 at the other end of the shaft portion 32.
3 is provided. The rod-shaped fixing bracket 30 of the embodiment
Is composed of a bolt and a nut. The head of the bolt forms the head 31 of the rod-shaped fixing bracket, and the nut forms the locking portion 33. The nut serving as the locking portion 33 is screwed to a bolt, and is fixed so as not to be displaced by welding or the like with a predetermined distance from the head 31. The head 3
The distance between the first garnish 10 and the locking portion 33 is
Is larger than the distance between the head 31 and the inner panel 21 of the vehicle body pillar portion 20 when the vehicle body pillar portion 20 is attached.

The rod-shaped fixing member 30 is not limited to a bolt and a nut. The head 31 and the locking portion 33 are larger than the diameter of the shaft portion 32 and the head 31 and the locking portion 33 What is necessary is that the interval is the predetermined interval. For example, rod-shaped fixing brackets 30A shown in FIGS.
30B, the heads 31A, 31B expanded at one end of the shafts 32A, 32B, and the locking parts 33A, 3 expanded at the other end.
An appropriate one such as one to which 3B is fixed by welding is used.

The head 31 of the rod-shaped fixing bracket 30 is previously coated with a synthetic resin coating layer 40 by injection molding or the like.
In this state, the pillar garnish 10 is buried in the seat portion 17 during injection molding. The surface 40s of the coating layer 40 located on the surface 31s of the head 31 is formed on the side surface 17
The surface shape is equal to the surface shape of the pillar garnish portion 10s surrounded by a. Thereby, the head 31
Of the pillar garnish 10 in the pillar garnish portion 10s covered with the side surface 17a of the seat portion 17, that is, the resin thickness T0 of the pillar garnish 10 is uniform. Sink can be prevented.

The head 31 of the rod-shaped fixture 30 is placed as an insert in a molding die while being covered with the coating layer 40. In this state, the pillar garnish 10 is injection-molded. The surface of the coating layer 40 is melted by the molding heat of
The head 31 of the rod-shaped fixture 30 is fused with the back surface of the pillar garnish 10 and the side surface 17a of the seat 17 via the coating layer 40 to be integrated. If the fusion strength during this injection molding is low,
The side surface 1 of the seat portion when the pillar garnish 10 is pressed and bent.
7a is peeled off from the coating layer 40, and the seat portion 17 serving as a hinge portion is removed.
Since stress concentrates on the base 18 of the steel and cracks easily occur,
It is preferable to increase the fusion strength.

The fusion at the time of the injection molding is performed by bringing the coating layer 40 into contact with the molten resin for pillar garnish injected into the molding die, and taking the heat of the molten resin so that the coating layer 40 melts. Done. However, the heat retained in the molten resin is not continuously replenished even after the injection, and the molten resin is in contact with the mold surface after the injection and is rapidly cooled and solidified. The amount of heat available is limited. For this reason, there is a possibility that the surface of the coating layer 40 is not sufficiently melted and a sufficient fusion strength between the coating layer 40 and the seat 17 or the like cannot be obtained.

In particular, when the resin constituting the pillar garnish 10 is TPO, the resin constituting the coating layer 40 should also be TPO compatible with the resin of the pillar garnish 10 in order to obtain reliable fusion. Is preferred. This TPO
Is based on PP (polypropylene)
Rubber such as EPR (ethylene / propylene rubber)
It contains PE (polyethylene), a softening agent, and the like as a rubber reinforcement, and the fusion property between TPOs is mainly obtained by PP. Therefore, in order to increase the fusion strength between the coating layer 40 and the seat portion 17 of the pillar garnish 10, the PP of the TPO constituting the coating layer 40 is added to the PP of the injection molten resin during the injection molding of the pillar garnish 10. Must be used sufficiently to ensure that the PP can be melted.

However, certain types of T constituting the coating layer 40 may be used.
When differential scanning calorimetry (referred to as DSC) was performed on PO, the results were as shown in FIG.
In PO, it was found that other components first melt at a lower temperature before the PP component, which is the main component, and then the PP component is melted. Therefore, during the injection molding of the pillar garnish, the heat of the injection molten resin is first used for melting other components having a lower melting point than the PP component in the TPO constituting the coating layer 40, and the remaining heat is used for the coating layer 40. PP in
Of the coating layer 40 and the T
Depending on the material of the PO, the PP component may not be sufficiently melted, and the bonding strength between the coating layer 40 and the seat 17 of the pillar garnish 10 may be insufficient.

The present inventor has studied variously the relationship between the DSC measurement result for the TPO and the fusion strength of the coating layer 40 to the seat portion 17 of the pillar garnish 10 (a crack in the hinge portion at the base of the seat portion). Then I found the following: That is, the TPO of the coating layer 40 contains at least 40 wt% of polypropylene, and the peak area S represented by DSC and representing the heat of fusion of the polypropylene.
1 and the peak area S2 indicating the heat of fusion of the component that melts at a lower temperature than polypropylene, the relationship S2 / S1 <1 /
If it is 2, it was found that when the pillar garnish 10 was opened due to the inflation of the airbag A, the hinge portion at the base portion 18 of the seat portion 17 did not crack.

Components that melt at a lower temperature than the polypropylene include high-density PE, low-density PE, ethylene-α
In addition to PE copolymers such as olefin copolymers and ethylene-acrylic acid copolymers, styrene-based polymers such as SE
Polymers that melt at a lower temperature than polypropylene, such as BS (styrene-ethylene-butene-styrene copolymer), may be used.

The bending elastic modulus F1 of the resin forming the coating layer 40 and the bending elastic modulus F2 of the synthetic resin forming the pillar garnish 10 (both ASTM D 790)
It is more preferable that the relationship of F1 <F2 is satisfied. By selecting the resin in this manner, it is possible to suppress the increase in the rigidity of the entire seat 17, and it becomes easy for the pillar garnish 10 to be bent in the vicinity of the seat 17 when the pillar garnish 10 is pressed by the inflation of the airbag A. The base portion 18 of the seat side surface 17a can be less likely to crack. Further, the range of the bending elastic modulus F1 of the resin constituting the coating layer 40 is 2000 to 7000 kg.
/ Cm ² , the range of the bending elastic modulus F2 of the resin constituting the pillar garnish 10 is 5,000 to 10,000 kg / cm
² is particularly preferred.

As shown in FIG. 4, the anti-rattle fixing portion 16 has a clip 45 made of metal or resin fixed to a clip seat 46 formed on the back surface of the pillar garnish 10. The clip 45 is inserted into and engaged with the clip hole 29 formed in the panel 21. The clip 45 of this example has a locking piece 45a bent so as to bulge outward, and by fixing the pillar garnish 10 to the vehicle body pillar portion 20, the pillar garnish 10 is fixed to the vehicle body pillar portion 20 without rattling, and the air is removed. When the pillar garnish 10 is pushed and bent by the inflation of the bag A, the clip 45 comes off from the clip hole 29 of the inner panel 21. Further, the clip seat 46 is formed in a thin rib shape so as not to cause sink marks on the design surface of the pillar garnish 10.

The vehicle body pillar portion 20 to which the pillar garnish 10 is attached has the clip hole 29 in the inner panel 21 and the locking hole 25 as shown in FIG. It is formed corresponding to the position. The locking hole 25 is formed of a long hole having a predetermined length along the longitudinal direction of the pillar garnish 10, and has a large-diameter hole 26 at the lower end through which the locking portion 33 of the rod-shaped fixing bracket 30 can be inserted. A shaft portion insertion passage 27 having a size smaller than the diameter of the locking portion 33 and large enough to allow the shaft portion 32 to pass therethrough is extended. And pillar garnish 10
At first, the locking portion 33 of the rod-shaped fixing bracket 30 is inserted into the large-diameter hole 26 of the locking hole 25 until the shaft portion 32 collides with the upper end 28 of the shaft portion insertion passage 27. The pillar garnish 10 is slid upward along the vehicle body pillar portion 20. As a result, the clip 45 moves onto the clip hole 29 of the inner panel 21. Then
At that position, insert the pillar garnish 10 into the inner panel 2
If the clip 45 is inserted into and engaged with the clip hole 29 by pushing strongly to the first side, the mounting of the pillar garnish 10 is completed.

When the pillar garnish 10 is attached to the vehicle body pillar portion 20 and the airbag A is expanded and the pillar garnish 10 is pushed and bent toward the vehicle interior, the locking portion 33 of the rod-shaped fixing bracket 30 is connected to the inner panel. The engagement with the shaft insertion passage 27 of the locking hole 25 of the 21 (that is, the engagement with the back surface of the shaft insertion passage 27) prevents the vehicle from being detached from the vehicle body pillar portion 20.

Table 1 shows specific examples and comparative examples of the fixing structure of the pillar garnish 10 with respect to the polypropylene weight% of the TPO constituting the coating layer 40, the peak area S1 indicating the heat of fusion of the polypropylene, and the peak area S1. It is a result of examining the relationship between the peak area S2 indicating the heat of fusion of the component that melts at a low temperature and the relationship between the presence or absence of a defect when the airbag A is deployed. The material of the pillar garnish 10 is TPO and S1
For the values of S2 and S2, the results obtained by DSC in a temperature rising process at a measurement condition of 10 ° C./min were used using Seiko Co., Ltd. as a measuring device. The presence or absence of a failure during the deployment of the airbag A was determined by mounting the pillar garnish 10 on an experimental jig and inflating the airbag A. Judgment was made based on the presence or absence of cracks or peeling of the pillar garnish 10 and the coating layer 40.

As is clear from Table 1, in Examples 1 to 3, cracks did not occur at the base portion 18 of the seat portion 17 when the airbag was deployed, and no problematic problem occurred.
In Comparative Examples 1 and 2, the side surface 17a of the seat 17 is peeled off from the coating layer 40 when the airbag A is deployed, and the base 18 of the seat 17 is opened.
A defect that caused cracks occurred. The flexural modulus F
1 and F2 were measured according to ASTM D790.

[0034]

[Table 1]

In the pillar garnish 10A shown in FIGS. 8 to 10, the reinforcing ribs 19 are formed radially outside the side surface 17a of the seat portion 17 as defined in claim 2, whereby the airbag A When the pillar garnish 10A is pushed and bent due to the expansion of the
Cracks at the base 18 of 7a can be more reliably prevented. The reinforcing rib 19 is used for the pillar garnish 10.
A 0.8-2.5mm thickness, taking into account sink marks on the design surface
Height 2-10mm, length 2-10mm, rib pitch 1
It is preferable that the diameter is set to 10 to 10 mm. Of course, also in this case, the bottom surface 17b of the seat 17 may be omitted. The reinforcing ribs 19 are preferably provided at least on the deployment side D of the airbag A of the seat 17.

[0036]

As described above, according to the mounting structure of the pillar garnish with the built-in airbag of the present invention, the pillar garnish can be prevented from coming off when the airbag inflates, and the design of the pillar garnish can be prevented. No concealment process is required on the surface, such as a cover
Moreover, since the occurrence of sink marks can be prevented, the appearance is improved. Furthermore, a general-purpose rod-shaped fixing bracket can be used, and it is not necessary to specially prepare a dedicated fixing rod, so that it does not lead to an increase in cost and has an effect of excellent economic efficiency.

Further, by increasing the fusion strength between the pillar garnish and the coating layer as in the structure of the present invention,
When the airbag is inflated, the pillar garnish and the coating layer do not peel off, so that the impact can be effectively absorbed and the generation of cracks at the base of the side surface of the seat can be prevented. Further, by forming the reinforcing ribs on the outside of the side surface of the seat portion, it is possible to more reliably prevent a crack from being generated when the airbag is deployed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a vehicle interior to which a pillar garnish is mounted by a mounting structure of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is an enlarged sectional view showing the vicinity of a rod-shaped fixing bracket of FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 1;

FIG. 5 is a partial perspective view showing a state where the pillar garnish of FIG. 1 is attached.

FIG. 6 is a sectional view showing an example without a seat bottom surface.

FIG. 7 is a perspective view showing another example of the rod-shaped fixing bracket.

FIG. 8 is a cross-sectional view of the embodiment of FIG.
It is sectional drawing.

9 is a cross-sectional view showing the vicinity of the rod-shaped fixing bracket of FIG.

FIG. 10 is a bottom view of the seat shown in FIG. 9;

FIG. 11 is a graph of a DSC of a resin constituting a coating layer.

FIG. 12 is a schematic diagram of a vehicle cabin to which a conventional pillar garnish with a built-in airbag is attached.

FIG. 13 is a schematic view showing an airbag when inflated.

FIG. 14 is a sectional view taken along line 14-14 of FIG.

FIG. 15 is an enlarged sectional view showing the vicinity of a rod-shaped fixing bracket of FIG.

FIG. 16 is an enlarged cross-sectional view showing the vicinity of a rod-shaped fixing bracket when the airbag is inflated and deployed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Pillar garnish 17 Seat part 20 Body pillar part 25 Locking hole 30 Bar-shaped fixing bracket 31 Bar-shaped fixing bracket head 33 Bar-shaped fixing bracket locking section 40 Coating layer

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60R 13/02 B60R 21/20 B60R 21/22

Claims (2)

(57) [Claims] 1. A rod-shaped fixture having a seat formed on the rear surface of a synthetic resin pillar garnish and having a large-diameter head at one end of a shaft and a locking portion provided at the other end of the shaft. The head is embedded during the injection molding of the pillar garnish, the locking portion of the rod-shaped fixing bracket is inserted and locked in the locking hole of the vehicle body pillar portion, the pillar garnish is attached, and the airbag accommodated on the back side of the pillar garnish is attached. At the time of pushing and bending the pillar garnish due to inflation, in the mounting structure of the airbag built-in pillar garnish configured to prevent the pillar garnish from coming off by engagement of the rod-shaped fixing metal with the locking hole, the head of the rod-shaped fixing metal is By covering the surface of the covering layer with a covering layer of a synthetic resin and making the surface of the covering layer equal to the pillar garnish surface shape of the portion surrounded by the side surface of the seat portion, The addition to the substantially uniform thickness of the pillar garnish of a portion surrounded by the side surface, the resin constituting the pillar garnish is made of a polyolefin-based thermoplastic elastomer, 40 wt resin is polypropylene which constitutes the coating layer
%, And the peak area S1 indicating the heat of fusion of the polypropylene, expressed by differential scanning calorimetry (DSC), and the peak area S2 indicating the heat of fusion of the component melting at a lower temperature than the polypropylene are represented by S2. / S1 <
A mounting structure of a pillar garnish with a built-in airbag, which is made of a 1/2 polyolefin-based thermoplastic elastomer. 2. The mounting structure for a pillar garnish with built-in airbags according to claim 1, wherein reinforcing ribs are formed radially at least on the outer side surfaces of the seat portion on the airbag deployment side.