JPH10291232A - Molding method for instrument panel with integrated air bag door section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the lowering of the outer appearance quality in a resin joining section. SOLUTION: A heat insulation material 36 is embedded in a site forming a joining section of resin from an air bag door section with resin from a main body section on a top force 30 forming the design face side of an instrument panel. A seal face 40A of a slide core 40 is brought into contact with the insulation material 36, and a cavity 34 is divided by the slide core 40. Because of the above arrangement, the cooling for an extreme front face 42 of a resin joining boundary section 26 is delayed by the insulation material 36, and the resin pressure is actuated securely to the last stage while the resin is in the molten state to reduce the weld sink marks formed on the joining boundary section 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming an instrument panel having an airbag door unit and a door unit of an airbag device for a passenger seat.

[0002]

2. Description of the Related Art An instrument panel integrally having an airbag door is known, and an example of a molding method thereof is disclosed in Japanese Patent Application Laid-Open No. Hei 8-192666.

In this method of molding an instrument panel integrally having an airbag door, the main body of the instrument panel having an opening for the airbag door is injection molded, and then the airbag door is injection molded. Thereby, the main body of the instrument panel and the airbag door are integrally formed.

[0004]

However, in such a method of forming an instrument panel integrally having an airbag door portion, as shown in FIG. 14, the main body portion 100 of the instrument panel and the airbag door portion 1 are formed.
At the boundary of the resin confluence with No. 02, the resin surface is cooled and the fluidity is reduced due to a decrease in the temperature of the injection resin due to the mold. As a result, the resin pressure does not act reliably to the end, and weld sink marks 106 are apt to occur in the appearance of the resin junction boundary portion 104 between the main body portion 100 of the instrument panel and the airbag door portion 102, and the appearance quality is deteriorated. .

In view of the above, an object of the present invention is to provide a method of forming an instrument panel integrally having an airbag door portion capable of preventing a deterioration in appearance quality at a resin merging portion.

[0006]

According to a first aspect of the present invention, there is provided an instrument panel having an airbag door integrally formed with an instrument panel body and an airbag door by injection molding. In the method, a heat insulating means is provided in a mold on a design side at a junction of a resin of an airbag door portion and a resin of a main body portion, and a sealing surface of a slide core is brought into contact with or close to the heat insulating means. A first molding step of injection-molding one resin in this state, and a second molding step of retracting the slide core after the first molding step and injecting the other resin in this state, It is characterized by including.

Accordingly, the heat insulation means provided on the design side mold delays the cooling of the outermost surface at the junction of the resin, and the resin pressure reliably acts on the resin in the molten state until the end.
Weld sink can be reduced, and a decrease in appearance quality can be prevented.

According to a second aspect of the present invention, there is provided a method of molding an instrument panel integrally including an airbag door portion for integrally molding a main body portion of the instrument panel and an airbag door portion by injection molding. Insulating means is arranged on the mold on the design side at the junction of the resin of the main part and the resin of the main part, and the cavity is divided by bringing the sealing surface of the slide core into contact with or close to the heat insulating means. A first molding step of injection molding both resins, and a second molding step of retracting the slide core and joining both resins in this state in the final stage of the first molding step. Features.

Therefore, the heat insulation means provided on the mold on the design side delays the cooling of the outermost surface at the junction of the resin, and the instrument panel body and the airbag door are simultaneously molded in a molten state. In addition, the appearance of the surface layer is good, and the injection molding time can be shortened, thereby improving the productivity.

According to a third aspect of the present invention, there is provided a method of molding an instrument panel integrally including an airbag door portion for integrally molding a body portion of the instrument panel and an airbag door portion by injection molding. The cavity is divided by bringing a slide core having a portion with a triangular cross section into contact with or near the design side mold surface,
In this state, a first molding step of injection molding one of the resin of the airbag door portion and the resin of the main body portion, and after the first molding step, the slide core is retracted, and in this state, the other resin is injection molded. And a second molding step.

Therefore, the joining portion of the resin has an inclined surface due to the slide core having a portion having a substantially triangular cross section at the tip, and the leading end width of the slide core is reduced, so that the cooling performance of the leading end of the core is reduced. The resin merging length also becomes shorter. As a result, the resin merging time is short, and the resin from the design side is merged, so that both are hard to cool down, so that weld sink at the merging boundary can be reduced and the appearance quality can be prevented from deteriorating. Further, since the cross-sectional shape of the preceding resin is inclined at the junction boundary, the resin injected later is unlikely to sneak into the resin design side, and the parting line does not meander.

According to a fourth aspect of the present invention, there is provided a method of forming an instrument panel integrally having an airbag door portion for integrally forming a main body portion of the instrument panel and an airbag door portion by injection molding. The cavity is divided by bringing a slide core having a portion with a triangular cross section into contact with or near the design side mold surface,
A first molding step of injection molding both resins in this state;
The final stage of the first molding step includes a second molding step of retracting the slide core and joining both resins in this state.

[0013] Therefore, the joining portion of the resin has an inclined surface due to the slide core having a portion having a substantially triangular cross-sectional shape at the tip, and the leading end width of the slide core is reduced, so that the cooling performance of the leading end of the core is reduced. Since the main body of the ment panel and the airbag door are simultaneously molded in a molten state, the appearance of the surface layer is good, the injection molding time can be shortened, and the productivity is improved.

According to a fifth aspect of the present invention, there is provided a method of molding an instrument panel integrally including an airbag door portion for integrally molding a main body portion of the instrument panel and an airbag door portion by injection molding. The cavity is divided by bringing the slide core inclined with respect to the side mold surface into contact with or close to the design side mold surface, and in this state, one of the resin of the airbag door portion and the resin of the main body portion is injection-molded. The method is characterized by including one molding step and a second molding step of, after the first molding step, retracting the slide core and injecting the other resin in this state.

Accordingly, since the leading end width of the slide core is reduced, the cooling performance at the leading end of the core is reduced, and the length at which the resin joins becomes shorter. As a result, the resin merging time is short, and the resin from the design side is merged, so that both are hard to cool down, so that weld sink at the merging boundary can be reduced and the appearance quality can be prevented from deteriorating. Further, since the cross-sectional shape of the preceding resin is inclined at the junction boundary, the resin injected later does not easily enter the resin design side, and the parting line does not meander.

According to a sixth aspect of the present invention, there is provided a method of molding an instrument panel integrally including an airbag door portion for integrally molding a main body portion of the instrument panel and an airbag door portion by injection molding. A first molding step of dividing the cavity by abutting or approaching a slide core inclined with respect to the side mold surface to the design side mold surface, and injecting both resins in this state;
At the final stage of the molding process, the slide core is retracted,
And a second molding step of combining both resins in this state.

Accordingly, since the tip width of the slide core is reduced, the cooling of the tip portion of the core is reduced, and the body portion of the instrument panel and the airbag door portion are simultaneously molded in a molten state, so that the appearance of the surface layer portion is improved. In addition, the injection molding time can be shortened, and the productivity is improved.

According to a seventh aspect of the present invention, there is provided a method of forming an instrument panel integrally having an airbag door portion according to any one of the third to sixth aspects, wherein a design side is provided at a tip end of the slide core. It is characterized in that a projection having a rectangular cross section that is in contact with or close to the mold surface is formed.

Therefore, the protrusion formed at the tip of the slide core increases the thickness space at the tip of the gap between the slide core and the design-side mold surface, so that the resin filling that portion is less likely to be cooled. Therefore, the resin pressure reliably acts on the resin in the molten state to the end, so that weld sink can be reduced, and a decrease in appearance quality can be prevented.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of an instrument panel having an airbag door unit according to the present invention.
This will be described with reference to FIG.

As shown in FIG. 4, an instrument panel 10 provided in the cabin of the vehicle includes an airbag device 12 (FIG. 3) on the inward side of the passenger seat (left side in FIG. 4).
Is partially shown).

As shown in FIG. 3, the airbag device 12
The airbag case 14 is fixed to an instrument panel reinforcement (not shown).
In the airbag case 14, an inflator 16 and an airbag 18 in a folded state are accommodated.

A portion of the instrument panel 10 substantially opposed to the airbag case 14 is an airbag door portion 20. The airbag door portion 20 is made of a soft resin such as TPO (thermoplastic olefin) or TPE.
(Thermoplastic elastomer, for example, flexural modulus 100 to 5
(00 MPa, elongation at -35 ° C 50 to 300%). On the other hand, the main body part 22 of the instrument panel 10 other than the airbag door part 20 is made of T
SOP [Bloomization of elastomer (rubber) and PP (polypropylene) (technology to produce a high-molecular-weight multi-component material that can be expected to have a synergistic effect), and the addition of talc for composite reinforcement, which has impact resistance and rigidity And a low-density PP resin having good fluidity and suitable for thin-walled products, for example, a flexural modulus of 150
0 to 3000 MPa], a PP resin, a PC / ABS resin, a modified PPO resin, an ASG resin, and the like.

The airbag device 12 detects an abrupt deceleration of the vehicle by a mechanical or electrical acceleration sensor (not shown) or the like.
Operates to inflate the airbag body 18 folded and housed in the airbag case 14 toward the airbag door portion 20 of the instrument panel 10.
The airbag body 18 presses the airbag door portion 20 of the instrument panel 10 to press the airbag door portion 20.
To be unfolded and deployed in the cabin. In addition,
As the airbag device 12, a conventionally known general configuration can be applied.
The detailed description of is omitted.

An upright wall 20A is provided upright from the periphery of the airbag door 20 to surround the outer periphery of the opening of the airbag case 14. Further, by surrounding the outer periphery of the opening of the airbag case 14 with the upright wall portion 20A, it is possible to prevent the airbag bag body 18 from expanding along the back surface of the main body portion 22 when inflated.

A thin portion 24 (notch portion) is formed in an H shape in a plan view at a substantially central portion in the front-rear direction and at both ends in the left-right direction of the airbag door portion 20. A thin hinge portion 25 is formed along the vehicle width direction. Accordingly, when the airbag door section 20 is pressed by the inflating airbag body 18 during deployment of the airbag, the airbag door section 20 is torn along the thin portion 24, and the torn airbag door section 20 is rotated, and the airbag door section 20 is rotated. An opening is formed so that the bag bag body 18 can be deployed into the vehicle interior.

A junction 26 with the main body 22 is formed on the outer periphery of the airbag door 20.

Next, a method for forming an instrument panel according to the first embodiment of the present invention will be described in detail.

First, as shown in FIG. 1, an upper mold 30 as a mold on the design side of the instrument panel, and a cavity 34 of the upper mold 30 and the lower mold 32 are provided with a predetermined gate (not shown). The airbag door section 20 is molded by injecting a soft resin (the airbag door section molding step as a first molding step). At this time, a heat insulating material 36 as heat insulating means is buried in the upper mold 30 at a portion where the resin of the airbag door portion and the resin of the main body portion meet.
Are disposed on the molding surface 30A of the upper die 30. Insulation material 3
The seal surface 40A of the slide core 40 is in contact with 6, and the slide core 40 divides the cavity 34 into a cavity forming the airbag door portion and a cavity forming the main body portion.

Therefore, in this airbag door molding step, the cooling of the outermost surface portion 42 of the resin merging boundary 26 is delayed by the heat insulating material 36 provided on the upper mold 30 on the design side. Works reliably to the end, so that weld sink at the junction boundary 26 can be reduced.

As shown in FIG. 5, the slide core 40 has a box shape having a substantially rectangular sealing surface 40A corresponding to the outer peripheral edge of the airbag door.

Further, as shown in FIG. 6, the slide core 40 is disposed in the lower mold 32 so as to be movable in the direction of coming and going with respect to the upper mold 30 (the directions of arrows A and B in FIG. 6). The bottom 40B of the slide core 40 is fixed to the upper surface 44A of the slide plate 44. The slide plate 44 is fixed to a stopper cylinder 48 via a cylinder mounting plate 46. By driving the stopper cylinder 48, the slide core 40 moves in the arrow A direction or the arrow B direction in FIG. ing.

In the main body forming step as the second forming step, as shown in FIG.
It moves to a position (a position indicated by a solid line in FIG. 2) lowered by a predetermined amount L in a direction away from a position (a position indicated by a two-dot chain line in FIG. 2) contacting 0 (a direction indicated by an arrow B in FIG. 2). Hard resin is injected into the cavity 34 between the upper mold 30 and the lower mold 32 to form the main body 2.
2 is injection molded.

At this time, the heat insulating material 36 provided on the upper mold 30 on the design side delays the cooling of the outermost surface portion 50 of the resin merging boundary portion 26, and the resin pressure reliably acts in the molten state to the end. , Weld sink at the junction boundary 26 can be reduced.

Therefore, in the method of forming an instrument panel according to the first embodiment of the present invention, the heat insulating material 36 provided on the upper mold 30 on the design side allows the resin of the airbag door portion 20 and the resin of the main body portion 22 to be combined. Since weld sink marks at the junction 26 can be reduced, a decrease in appearance quality can be prevented.

As shown in FIG. 7, the inside of the slide core 40 is processed by an under part 52, and the inside of the slide core 40 is passed through a tunnel gate 54 inserted into an opening 40C formed in the slide core 40. The resin of the airbag door section 20 is injected from the nozzle 56.
At this time, a portion 58 connecting the airbag door portion 20 and the tunnel gate 54 is cut and removed by post-processing.

The same effect can be obtained even if the heat insulating material 36 as a heat insulating means is a heat-treated surface treatment layer.

Next, a second embodiment of the present invention will be described with reference to FIGS. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 8, in the method of forming an instrument panel having an airbag door unit according to the second embodiment of the present invention, the tip 60 of the slide core 40 has a substantially triangular cross section. The slide core 40
Is, for example, 90 degrees.

Accordingly, in the second embodiment, the tip 60 of the slide core 40 is placed in the upper mold 30 with the gap T (0 <T ≦ 2L).
/ 3) is opened and brought into proximity to divide the cavity 34 into a cavity forming the airbag door portion and a cavity forming the main body portion, and in this state, the resin of the airbag door portion 20 is injection-molded (first molding). Airbag door molding process as a process). At this time, the tip 60 of the slide core 40
Has a substantially triangular cross section, so that the slide core 40
Since the leading end of the core becomes smaller, the cooling performance of the leading end of the core becomes less noticeable, and the length at which the resin joins becomes shorter. As a result, the resin merging time is short, and the resin from the design side is merged, so that both are hardly cooled, the weld sink at the merging boundary 26 can be reduced, and the appearance quality can be prevented from deteriorating.

In the next main body forming step as the second forming step, as shown in FIG.
Move to a position (a position indicated by a solid line in FIG. 9) lowered by a predetermined amount N in a direction away from 0 (direction of arrow B in FIG. 9), and in this state, hard resin is poured into the cavity 34 between the upper mold 30 and the lower mold 32. The main body 22 is injection-molded.

At this time, since the leading end 60 of the slide core 40 has a substantially triangular cross-sectional shape, the leading end of the slide core 40 becomes smaller, so that the cooling performance of the leading end of the core is reduced, and the length of the resin confluence also becomes shorter. . As a result, since the resin merging time is short and the resin from the design side is merged, both are hardly cooled, weld sink at the merging boundary 26 can be reduced, and the appearance quality can be prevented from deteriorating.

The junction 26 between the resin of the airbag door portion 20 and the resin of the main body portion 22 has a substantially triangular cross-sectional tip, and the cross-sectional shape of the preceding resin is inclined. To the resin of the injected airbag door part 20,
It is possible to prevent the resin of the main body 22 injected after the core back from sneaking in, and the parting line does not meander.

Therefore, in the method of forming an instrument panel according to the second embodiment of the present invention, the airbag door section 20 is provided.
The appearance quality of the junction 26 between the resin and the resin of the main body 22 can be prevented from deteriorating.

In the second embodiment, a gap T (0 <T ≦ 2) is provided between the tip 60 of the slide core 40 and the upper die 30.
L / 3) is opened to eliminate the interference between the slide core 40 and the upper mold 30 and improve the durability. However, even when the gap T = 0, the tip 60 of the slide core 40 is brought into contact with the upper mold 30. Good.

As shown by a two-dot chain line in FIG. 8, the molding surface 30 of the upper die 30 is
A protruding portion 60 </ b> A having a predetermined width W and having a rectangular cross section that comes into contact with A may be formed. In this case, the tip portion 60 of the slide core 40
Is formed, the thickness space M at the tip of the cavity 34 between the slide core 40 and the upper die 30 is increased, so that the resin is hardly cooled down to the tip of the cavity 34, that is, the junction 26. I do. As a result, the appearance quality is improved.

Next, a third embodiment of the present invention will be described with reference to FIGS. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 10, in the method of forming an instrument panel integrally having an airbag door according to the third embodiment of the present invention, the tip 62 of the slide core 40 is provided.
Are inclined with respect to the molding surface 30A of the upper die 30. The inclination angle α of the tip 62 of the slide core 40 is, for example, 45 degrees or less.

Therefore, in the second embodiment, the tip 62 of the slide core 40 is inserted into the upper die 30 with the gap T (0 <T ≦ 2L).
/ 3) is opened and brought close to each other, the cavity 34 is divided into a cavity forming the airbag door portion and a cavity forming the main body portion, and in this state, the resin of the airbag door portion 20 is injection-molded (first molding). Airbag door molding process as a process). At this time, the tip 62 of the slide core 40
Are inclined with respect to the molding surface 30A of the upper mold 30,
Since the leading end of the slide core 40 is small, the cooling ability of the leading end of the core is reduced, and the length of resin consolidation is also reduced. As a result, since the resin merging time is short and the resin from the design side is merged, both are hardly cooled, weld sink at the merging boundary 26 can be reduced, and the appearance quality can be prevented from deteriorating.

In the main body molding step as the second molding step, as shown in FIG. 11, the slide core 40 is lowered by a predetermined amount M in the direction away from the upper die 30 (the direction of arrow B in FIG. 11). (The position indicated by the solid line in FIG. 11). In this state, the hard resin is injected into the cavities 34 of the upper mold 30 and the lower mold 32, and the main body 22 is injection molded.

At this time, since the junction 26 between the resin of the airbag door section 20 and the resin of the main body section 22 is at the tip of the inclined surface 20B and the sectional shape of the preceding resin is inclined, the preceding injection is performed. The resin of the main body 22 injected after the core back into the resin of the airbag door 20 can be prevented from getting into the resin, and the parting line does not meander.

Accordingly, in the method for forming an instrument panel according to the third embodiment of the present invention, the airbag door section 20 is provided.
The appearance quality of the junction 26 between the resin and the resin of the main body 22 can be prevented from deteriorating.

In the third embodiment, a gap T (0 <T ≦ 2) is provided between the tip 60 of the slide core 40 and the upper die 30.
L / 3) is opened to eliminate the interference between the slide core 40 and the upper mold 30 and improve the durability. However, even when the gap T = 0, the tip 60 of the slide core 40 is brought into contact with the upper mold 30. Good.

As shown in FIG. 12, a projecting portion 62A having a rectangular cross section with a predetermined width W may be formed at the tip end portion 62 of the slide core 40 so as to be in contact with the molding surface 30A of the upper die 30. In this case, the protrusion 62A formed at the distal end portion 62 of the slide core 40 increases the thickness space M at the distal end of the cavity 34 between the slide core 40 and the upper die 30. Therefore, as shown in FIG.
, That is, the resin is hardly cooled down to the merging boundary 26 and is filled. As a result, the appearance quality is improved.

In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to such an embodiment, and various other embodiments are included within the scope of the present invention. It is clear to a person skilled in the art that is possible. For example, in the present embodiment, the airbag door unit 20
After molding the first, the instrument panel body 22
, But on the contrary, the instrument panel body 22
The airbag door section 20 may be molded after molding. Further, the slide core 40 divides the cavity 34 into a cavity forming the airbag door portion and a cavity forming the main body portion, and in this state, injects both the resin of the airbag door portion and the resin of the main body portion. In the final stage of the first molding step, the slide core 40 is retracted, and in this state, both the resin of the airbag door portion and the resin of the main body portion merge (the second molding step). ). In this case, since the resin of the airbag door portion and the resin of the main body portion are molded in a molten state, the appearance of the surface layer portion is good, and the injection molding time can be shortened, so that the productivity is also improved. .

In this embodiment, the resin of the airbag door 20 and the resin of the main body 22 are different from each other. However, the resin of the airbag door 20 and the resin of the main body 22 are replaced with each other. May be the same resin.

[0057]

According to the first aspect of the present invention, there is provided a method of molding an instrument panel integrally having an airbag door portion for integrally molding an instrument panel body portion and an airbag door portion by injection molding. Insulating means is disposed on the mold on the design side at the junction of the resin of the bag door portion and the resin of the main body portion, and the cavity is divided by contacting or approaching the sealing surface of the slide core to the insulating means. Since the method includes a first molding step of injection molding one resin in this state, and a second molding step of retracting the slide core after the first molding step and injecting the other resin in this state, weld sink is reduced. This has an excellent effect that the appearance quality can be prevented from deteriorating at the resin merging portion.

According to a second aspect of the present invention, there is provided a method of molding an instrument panel integrally having an airbag door portion for integrally molding a main body portion of the instrument panel and an airbag door portion by injection molding. Insulation means is arranged on the mold on the design side at the junction of the resin of the part and the resin of the main body part, and the cavity is divided by bringing the slide surface of the slide core into contact with or close to the heat insulation means. Since a first molding step of injection molding both resins and a second molding step of retreating the slide core and joining both resins in this state at the final stage of the first molding step, the resin joining section Has an excellent effect that deterioration in appearance quality can be prevented. Further, it has an excellent effect that the injection molding time can be shortened and the productivity is improved.

According to a third aspect of the present invention, there is provided a method of molding an instrument panel integrally including an airbag door portion for integrally molding the main body portion of the instrument panel and the airbag door portion by injection molding. The cavity is divided by bringing a slide core having a portion with a triangular cross section into contact with or near the design side mold surface,
In this state, a first molding step of injection-molding one of the resin of the airbag door part and the resin of the main body part, and after the first molding step, the slide core is retracted, and in this state, the other resin is injection-molded. Since the method includes the two molding steps, it has an excellent effect that deterioration of the appearance quality at the resin confluence portion can be prevented. Further, there is an excellent effect that the parting line does not meander.

According to a fourth aspect of the present invention, there is provided a method of molding an instrument panel integrally including an airbag door portion for integrally molding a main body portion of the instrument panel and an airbag door portion by injection molding. The cavity is divided by bringing a slide core having a portion with a triangular cross section into contact with or near the design side mold surface,
A first molding step of injection molding both resins in this state;
At the final stage of the first molding process, the slide core is retracted,
Since the method includes the second molding step of joining both resins in this state, it has an excellent effect that weld sink can be reduced and deterioration in appearance quality at the resin joining portion can be prevented. Further, it has an excellent effect that the injection molding time can be shortened and the productivity is improved.

According to a fifth aspect of the present invention, there is provided a method of molding an instrument panel integrally having an airbag door portion for integrally molding a main body portion of the instrument panel and an airbag door portion by injection molding. The cavity is divided by bringing the slide core inclined with respect to the side mold surface into contact with or close to the design side mold surface, and in this state, one of the resin of the airbag door portion and the resin of the main body portion is injection-molded. Since the method includes the first molding step and the second molding step in which the slide core is retracted after the first molding step and the other resin is injection-molded in this state, weld sink can be reduced, and the appearance quality at the resin merging portion is reduced. Has an excellent effect that it can be prevented. Further, there is an excellent effect that the parting line does not meander.

According to a sixth aspect of the present invention, there is provided a method of molding an instrument panel integrally having an airbag door portion for integrally molding a main body portion of the instrument panel and an airbag door portion by injection molding. A first molding step in which the cavity is divided by bringing a slide core inclined with respect to the mold surface into contact with or close to the design-side mold surface and injecting both resins in this state, and a final stage of the first molding step And a second molding step of retracting the slide core and joining both resins in this state.
It has an excellent effect that the appearance quality can be prevented from lowering at the resin merging portion. Further, it has an excellent effect that the injection molding time can be shortened and the productivity is improved.

According to a seventh aspect of the present invention, there is provided a method of forming an instrument panel integrally having an airbag door portion according to any one of the third to sixth aspects, wherein a design side mold is provided at a tip end of the slide core. Since the projection having a rectangular cross section that is in contact with or close to the surface is formed, in addition to the effect according to any one of claims 3 to 6, the pre-injected resin is hardly cooled to the junction boundary and is filled. It has an excellent effect that the appearance quality is further improved.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an airbag door forming step in a method of forming an instrument panel integrally including an airbag door according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a main body forming step in a method of forming an instrument panel integrally including an airbag door according to the first embodiment of the present invention.

FIG. 3 is a sectional view taken along line 3-3 in FIG.

FIG. 4 is a perspective view showing an instrument panel integrally including an airbag door according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing a slide core in the method for forming an instrument panel integrally including the airbag door portion according to the first embodiment of the present invention.

FIG. 6 is a schematic sectional side view showing a slide core and a drive unit of the slide core in the method of forming an instrument panel having an airbag door unit according to the first embodiment of the present invention;

FIG. 7 is a schematic cross-sectional view showing a resin supply in an airbag door portion forming step in a method of forming an instrument panel integrally including an airbag door portion according to the first embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view showing an airbag door portion forming step in a method of forming an instrument panel integrally including an airbag door portion according to a second embodiment of the present invention.

FIG. 9 is a schematic cross-sectional view showing a main body forming step in a method of forming an instrument panel integrally including an airbag door according to a second embodiment of the present invention.

FIG. 10 is a schematic cross-sectional view showing an airbag door portion forming step in a method of forming an instrument panel integrally including an airbag door portion according to a third embodiment of the present invention.

FIG. 11 is a schematic cross-sectional view showing a main body forming step in a method of forming an instrument panel integrally including an airbag door according to a third embodiment of the present invention.

FIG. 12 is a schematic cross-sectional view showing an airbag door portion forming step in a method of forming an instrument panel integrally including an airbag door portion according to a modification of the third embodiment of the present invention.

FIG. 13 is a schematic cross-sectional view showing a main body forming step in a method of forming an instrument panel integrally including an airbag door according to a modification of the third embodiment of the present invention.

FIG. 14 is a perspective view showing a resin confluence boundary portion between a body of an instrument panel integrally having an airbag door portion according to a conventional embodiment and an airbag door portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Instrument panel 12 Airbag apparatus 20 Airbag door part 22 Main body part 26 Confluence boundary part 30 Upper die (a mold on the design side) 32 Lower die 34 Cavity 36 Heat insulating material 40 Slide core 40A Seal surface 42 Resin confluence boundary part 50 A top surface of the junction of the resin 60 A tip of the slide core 62 A tip of the slide core 62A A projection with a rectangular cross section formed at the tip of the slide core

Claims (7)

[Claims] 1. A method of molding an instrument panel integrally including an airbag door portion for integrally molding a main body portion of an instrument panel and an airbag door portion by injection molding. Insulating means is provided on the mold on the design side at the junction with the resin, and the cavity is divided by bringing the sealing surface of the slide core into contact with or close to the insulating means. In this state, one of the resins is injection-molded. And a second molding step of, after the first molding step, retracting the slide core and injecting the other resin in this state. Method for forming an instrument panel having the same. 2. A method of molding an instrument panel integrally including an airbag door portion for integrally molding a main body portion of an instrument panel and an airbag door portion by injection molding. A heat insulating means is arranged in a mold on the design side at a junction with the resin, and the cavity is divided by bringing the slide surface of the slide core into contact with or close to the heat insulating means, and in this state, both resins are injection-molded. An airbag door portion, comprising: a first molding step to perform; and, in a final stage of the first molding step, a second molding step of retracting the slide core and merging both resins in this state. Method of forming an instrument panel integrally having 3. A method of molding an instrument panel integrally having an airbag door portion for integrally molding a body portion of the instrument panel and an airbag door portion by injection molding, wherein a portion having a tip having a substantially triangular cross-sectional shape is provided. A first molding step of injecting or molding one of the resin of the airbag door portion and the resin of the main body portion in this state by abutting or approaching the slide core having the design side mold surface to or near the design side mold surface; A second molding step of retreating the slide core after one molding step and injecting the other resin in this state, a method of molding an instrument panel integrally having an airbag door portion. 4. A method for molding an instrument panel integrally including an airbag door portion for integrally molding a body portion of the instrument panel and an airbag door portion by injection molding, wherein a portion having a tip having a substantially triangular cross-sectional shape is provided. A cavity is divided by bringing or bringing the slide core into contact with or near the design side mold surface, and in this state, a first molding step of injection molding both resins; And a second molding step of combining both resins in this state. A method of molding an instrument panel integrally having an airbag door portion. 5. A method for molding an instrument panel integrally having an airbag door portion for integrally molding a body portion of the instrument panel and an airbag door portion by injection molding, wherein a tip is inclined with respect to a design side mold surface. A first molding step of injecting or molding one of the resin of the airbag door portion and the resin of the main body portion in this state by bringing the slide core into or out of contact with the design-side mold surface to divide the cavity; A second molding step of retreating the slide core after one molding step and injecting the other resin in this state, a method of molding an instrument panel integrally having an airbag door portion. 6. A method of molding an instrument panel integrally having an airbag door portion for integrally molding a body portion of the instrument panel and an airbag door portion by injection molding, wherein a tip is inclined with respect to a design side mold surface. The cavity is divided by bringing the slide core into contact with or close to the design side mold surface, and in this state, a first molding step of injection molding both resins; And a second molding step of combining both resins in this state. A method of molding an instrument panel integrally having an airbag door portion. 7. The airbag according to claim 3, wherein a protrusion having a rectangular cross section that is in contact with or near the design side mold surface is formed at a tip end of the slide core. A method for molding an instrument panel having a door unit.