JPH08118407A - Internal trim of resin-made speaker grille integrated type and its molding die - Google Patents

Abstract

PURPOSE: To mold integrally a speaker grille wherein a porous part of the grille is fine in texture and has a sophisticated feeling into an internal trim by a comparatively simple structure. CONSTITUTION: In an internal trim (a door pocket trim) 3 wherein a porous resin-made speaker grille 5 is integrally molded at a specific position, for the porous part of the speaker grille each hole diameter is set to 2.0mm or under, a pitch is set to 2.8mm or under, and a maximum wall thickness between adjacent holes is set to 0.6-0.8mm; the door pocket trim is molded by using polypropylene of 45 [g/10min] or over in melt flow rate as molding resin material. Further, in a molding die for molding that, plating treatment is applied onto a die surface corresponding to the porous part, and besides a negative pressure gas vent mechanism is provided onto at least any one die rear face side corresponding to the porous part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interior trim integrally formed with a porous resin speaker grill and a molding die for the trim.

[0002]

2. Description of the Related Art Conventionally, when a speaker such as an on-vehicle audio device is arranged in a vehicle in a vehicle such as an automobile, it is generally arranged on the back side of an interior trim as an interior member of the vehicle interior. For example, in a 4-speaker type audio system in which a pair of left and right speakers are arranged on the front side and the rear side of a vehicle compartment, generally, a front speaker is provided on the rear side of a door trim of a left and right front door, while a rear speaker is provided. Is located on the rear side of the rear package trim behind the rear seats.

When the speaker is arranged on the back side of the interior trim as described above, it is necessary to provide the speaker grill on the interior trim itself made of synthetic resin. In this case, prepare a speaker grill molded separately from the interior trim, and attach this speaker grill to the speaker grill opening provided at a predetermined location of the interior trim to integrate it. Conventionally, it is general. For example, in Japanese Utility Model Laid-Open No. 25395/1992, a resin-made interior trim in which reinforcing ribs are integrally provided in an opening portion for a speaker grill is formed, and a metal perforated plate (so-called punching metal) is separately provided. There is disclosed a structure in which a speaker grill made of metal is prepared and this punching metal is attached to the speaker grill opening of the interior trim. Also, for example, actual Kaihei 6-529
No. 0 gazette also discloses a resin-made interior trim to which a separate punching metal speaker grill is attached.

On the other hand, when the speaker grill is provided on the interior trim, it is considered that the speaker grill is integrally formed at the time of resin molding of the interior trim. By integrally molding the two in this way, there is no need to separately prepare a speaker grill, and the labor for assembling the speaker grill to the interior trim can be saved. Can be greatly simplified.

[0005]

However, when it is attempted to form the speaker grill integrally with the interior trim, the hole diameter and pitch of the perforated portion are ensured in order to ensure formability in the perforated portion of the speaker grill. Above a certain level (for example, if the hole diameter is about 3.0 mm or more and the pitch is
It is necessary to set a large value (about m or more). For this reason, the porous portion of the grill cannot be made very fine, and there is a problem in appearance that the speaker grill does not have a sufficient high-class feeling. In addition, since the hole diameter is large, foreign matter such as dust and dust is likely to be mixed into the speaker, which may adversely affect the characteristics and durability of the speaker, which is a practical problem.

That is, in the case where the speaker grill is integrally molded with the interior trim, when the molten resin injection gate is provided in the mold portion corresponding to the speaker grill portion where the passage of the molten resin becomes fine and complicated, the above-mentioned porous Since it becomes difficult for the resin to flow in the portion, it is difficult to sufficiently spread the molten resin over the entire trim, and it is easy to cause a thin wall. Further, if the injection pressure of the molten resin is set high in order to prevent the occurrence of this lack of thickness, there is a problem that burrs are likely to occur in the porous portion. On the other hand, when the injection gate is provided not in the porous portion but in the mold portion corresponding to an appropriate position of the trim portion which is apart from the porous portion to some extent, in the porous portion where the passage of the molten resin is fine and complicated. Air accumulates and becomes difficult to escape, it is difficult to spread the molten resin to this portion sufficiently, and again, it is easy to cause a thin wall. Therefore, it is necessary to increase the hole diameter and the pitch of the porous portion to a certain extent or more to facilitate the flow of the molten resin and to secure the moldability.

However, it is conceivable that injection gates are provided in both the porous portion and the trim portion, and the molten resin is injected from both gates at the same time. In this case, the injection pressure at both gates is adjusted. It is required to make the pressure the same, and it is very difficult to set this pressure condition, which is not practical. In addition, a so-called valve gate system in which injection gates with valves are provided in both the porous portion and the trim portion, and when one gate is used for injection, the other gate is closed and injection is performed stepwise from each gate By adopting, it is possible to reliably fill both the porous portion and the trim portion with the molten resin, but in this case, the molding process becomes complicated and the molding die is also complicated and expensive. There was a problem that it would be something.

The present invention has been made in view of the above problems, and is a resin speaker grill having a relatively simple structure and capable of integrally molding a high quality speaker grill with a fine porous portion of the grill. It is an object to provide an interior trim of a body shape and a mold for molding the same.

[0009]

Therefore, the invention according to claim 1 of the present application (hereinafter referred to as the first invention) is an interior trim in which a porous resin speaker grill is integrally formed at a predetermined position. In the interior trim, the hole diameter of the perforated portion of the speaker grill is 2.0 mm or less and the pitch is 2.8 mm or less, and the maximum wall thickness between adjacent holes is 0.6 to 0. It is set to 8 mm and is characterized by being molded using a polypropylene resin having a melt flow rate of 45 [g / 10 min] or more as a molding resin material.

Regarding the perforated portion of the speaker grill, the upper limit value of each hole diameter is set to 2.0 mm. When the hole diameter exceeds this value, the perforated portion becomes rough and the appearance as a speaker grill is improved. This is because the quality of the speaker is deteriorated and the sense of quality is impaired, and foreign matter such as dust and dust is easily mixed in the speaker, which may adversely affect the characteristics and durability of the speaker. Also, the upper limit of the pitch of the holes is set to 2.8 mm. When the pitch exceeds this value, the porous portion of the speaker grill becomes coarse and the appearance deteriorates and the high-class feeling is impaired. Because it is done. Furthermore, regarding the maximum wall thickness between adjacent holes,
The lower limit is set to 0.6 mm because this maximum wall thickness is 0.6
If it is less than mm, the flow of the molten resin in the above-mentioned porous portion will be deteriorated and molding will be hindered, and there is a possibility that a wall thickness will be generated in this portion, and the upper limit is set to 0.8 mm. When the maximum thickness exceeds 0.8 mm, the porous portion of the speaker grill becomes rough and the appearance is deteriorated and the high-class feeling is impaired. Also,
Further, the lower limit value of the melt flow rate of the molding resin material is set to 45 [g / 10 min] because the hole diameter, the pitch and the maximum wall thickness between adjacent holes are set as described above for the porous portion of the speaker grill. If polypropylene resin is used as the molding resin material, the melt flow rate will be 45
This is because if it is less than [g / 10 min], the flowability of the molten resin in the porous portion becomes poor, and it is difficult to secure sufficient moldability.

The invention according to claim 2 of the present application (hereinafter,
The second invention) is characterized in that, in the first invention, the aperture ratio of the porous portion of the speaker grill is set to 40% or more. The lower limit of the aperture ratio of the porous portion is set to 40%, because if the aperture ratio is less than 40%, it is difficult to secure good sound permeability of the speaker grill.

The invention according to claim 3 of the present application (hereinafter,
(Third invention) is a molding die for molding an interior trim in which a porous resin speaker grill is integrally molded at a predetermined location, and the interior trim is a porous part of the speaker grill. , Each hole diameter is 2.0mm
Polypropylene having a pitch of 2.8 mm or less, a maximum wall thickness between adjacent holes of 0.6 to 0.8 mm, and a melt flow rate of 45 [g / 10 min] or more as a molding resin material It is molded using a resin, and the mold surface corresponding to the above-mentioned porous portion is subjected to plating treatment, while a gas venting mechanism is provided on at least one mold back surface side corresponding to the above-mentioned porous portion. It is characterized by being.

Regarding the perforated portion of the speaker grill integrally formed with the interior trim by the above-mentioned molding die, the upper limit of each hole diameter is set to 2.0 mm. The reason is that if the hole diameter exceeds this value, the perforated portion will be textured. The external appearance of the speaker grille is deteriorated and the high-class feeling is impaired, and foreign matter such as dust and dust is easily mixed in the speaker, which may adversely affect the characteristics and durability of the speaker. Because it can be considered. Also, the upper limit of the pitch of the holes is set to 2.8 mm. When the pitch exceeds this value, the porous portion of the speaker grill becomes coarse and the appearance deteriorates and the high-class feeling is impaired. Because it is done.
Furthermore, the lower limit of the maximum wall thickness between adjacent holes is set to 0.6 mm, because when the maximum wall thickness is less than 0.6 mm, the flow of the molten resin in the above-mentioned porous portion becomes poor and molding is performed. This is because there is a risk that it may cause a lack of meat at this part, and the upper limit value was set to 0.8 mm. If the maximum thickness exceeds 0.8 mm, the speaker grill is This is because the porous portion has a rough texture and the appearance is deteriorated, and the high-class feeling is impaired. Further, the lower limit of the melt flow rate of the molding resin material is 45 [g / 1
0 min] is the melt flow rate when the hole diameter, pitch and maximum wall thickness between adjacent holes are set as described above for the porous portion of the speaker grill and polypropylene resin is used as the molding resin material. Is 45 [g / 10mi
If it is less than n], the flowability of the molten resin in the porous portion becomes poor, and it is difficult to secure sufficient moldability.

[0014]

According to the first invention of the present application, the hole diameter, the pitch and the maximum wall thickness between the adjacent holes are set as described above in the porous portion of the speaker grill, and the melt flow as the molding resin material is performed. Since polypropylene resin with a rate of 45 [g / 10 min] or more was used, when molding the speaker grill integrally with the interior trim, ensure sufficient moldability and mold without causing defects such as wall thickness. In addition, it is possible to effectively prevent foreign matter such as dust and dust from entering the inside of the speaker, and to make the perforated portion of the speaker grill fine and classy.

Further, according to the second invention of the present application, basically, the same effect as that of the first invention can be obtained. Moreover, since the aperture ratio of the porous portion is set to 40% or more, the volume transparency of the peaker grill can be well ensured.

Further, according to the third invention of the present application, the hole diameter, the pitch and the maximum wall thickness between the adjacent holes are set as described above in the porous portion of the speaker grill integrally molded with the interior trim by the molding die. With this setting, it is possible to effectively prevent foreign matter such as dust and dust from entering the inside of the speaker, and it is possible to integrally form a high-quality speaker grill with a fine porous portion. In this case,
Melt flow rate of 45 [g / 1 as resin material for molding
Since the polypropylene resin of 0 min] or more is used, when the speaker grill is integrally formed with the interior trim, sufficient moldability can be secured and the speaker grill can be formed without causing defects such as wall thickness. Further, since a gas venting mechanism is provided on at least one of the back surfaces of the molds corresponding to the porous portion, the air flowing into the mold molding portion corresponding to the porous portion will flow to this mold molding portion. It is smoothly discharged to the outside of the mold without accumulating, and the moldability can be secured more reliably. Furthermore, since the mold surface corresponding to the above-mentioned porous portion is plated, it is possible to improve the releasability when the molded product (interior trim) is demolded after molding.

[0017]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings in the case where the present invention is applied to, for example, a door trim of an automobile. FIG. 1 is a perspective view of a door trim 1 of a right front door of a vehicle according to the present embodiment. As shown in this figure, the door trim 1 is assembled to a door inner panel (not shown) and its interior The door trim main body 2 for covering the side and the door trim main body 2 are separately molded, and are assembled to the lower vehicle compartment side of the door trim main body 2 to form a door pocket 3a. A speaker grill 5 of an in-vehicle speaker (not shown) arranged on the back side of the front portion 3 (the left side portion in FIG. 1) is integrally formed.

The door trim main body 2 and the door pocket trim 3 are both molded by injection molding using a synthetic resin as a molding material, and the door trim main body 2 has a surface of an upper part 2a thereof such as a so-called fabric or the like skin. While the material is attached, the surface of the lower portion 2b is covered with, for example, a vinyl chloride skin material with a foam layer. As will be described in detail later, the door pocket trim 3 is molded by using a polypropylene resin having predetermined physical properties as a molding resin material, and the porous speaker grill 5 is integrally formed at the time of molding the resin. It is molded.

In this embodiment, the door pocket trim 3 is used.
In injection molding, as shown in FIG. 2, not a porous portion of the speaker grill 5, but an appropriate portion of a trim portion apart from this porous portion, more preferably,
Injection for injecting the molten resin material into the mold forming cavity into the mold portion corresponding to the portion 13 (the portion indicated by the broken line circle in FIG. 2) located substantially in the center of the door pocket trim 3. A gate (not shown) is provided,
This injection gate is connected to the mold molding part corresponding to the above-mentioned porous part.
Molten resin is supplied from (not shown) through a molding cavity in the middle. Further, in order to secure the fluidity of the molten resin to the end, a heating element pin gate type hot runner was used.

As shown in FIG. 11, the hot runner 20 is mounted on a lower mold 12 corresponding to the back side of the door pocket trim 3 among a pair of molds 11 and 12 for injection molding the door pocket trim 3. Attached, both molds 1 above
The tip is connected to an injection gate 10a (pin gate) for injecting the molten resin into the molding cavity 10 formed by 1 and 12. The hot runner 20 has a hollow cylindrical body 21 in which a molten resin passage 21a is formed.
And a heating element 22 that covers the outer peripheral side of the tubular body 21 as a main part, and a conductive cord that connects the heating element 22 and a power source (not shown) to the rear end flange portion 22a of the heating element 22. 19
Are tied together. A current is supplied to the conductive cord 19 at a low voltage of, for example, about 1 to 3 volts. Although not specifically shown, the hot runner 20 is provided with a temperature sensor for measuring the heating temperature of the heating element 22. By using the heating element pin gate type hot runner 20 as described above, the temperature of the molten resin can be controlled up to immediately before the pin gate 10a by the heating action of the heating element 22. When the resin is injected into the interior, the resin temperature may fluctuate, causing deficiency (when the resin temperature is too low) and burrs in the porous part of the speaker grill 5.
It is possible to effectively prevent (when the resin temperature is too high) from occurring.

As shown in FIG. 3, the porous portion of the speaker grill 5 is provided with a large number of ribs 6 having, for example, a hexagonal shape in plan view for reinforcing the porous portion.
A large number of ejector pins 7A, 7B, 7C of a plurality of types for pushing up and releasing the molded product when the molded product (door pocket trim 3) is taken out from the mold after injection molding are attached. In this embodiment, the width of the hexagon formed by the rib 6 is about 20 mm and the thickness of the rib 6 is about 1.3 mm.
The height of the rib 6 is set to about 2.4 mm. Further, as shown in detail in FIG. 4, ejector pins 7C and degassing pins 8 are alternately arranged at the joints of the reinforcing ribs 6. The degassing pin 8 can be seen in FIG.
For example, in the lower mold 12 of the upper and lower molds 11 and 12, it is arranged on the mold rear surface side, and more preferably at a portion corresponding to the lower part of the knot portion of the reinforcing rib 6. The ejector pin 7C or the degassing pin 8 may be arranged in the middle of the rib 6 instead of the knot portion of the rib 6.

As shown in FIG. 6, the gas vent pin 8 is provided with a plurality of vertical grooves 8a of a predetermined depth extending in the axial direction on the outer peripheral portion thereof, and each of the vertical grooves 8a is more preferable. The depth from the outer peripheral surface is set to 0.01 to 0.02 mm. By setting the groove depth of the vertical groove 8a in this way, during molding, the molten resin injected from the injection gate (not shown) passes through the molding cavity in the middle and the metal corresponding to the porous portion of the speaker grill 5 is formed. When the gas (air) in the molding cavity flows into the mold molding portion corresponding to this porous portion when reaching the mold molding portion, the air is supplied to the vertical groove 8a formed on the outer peripheral portion of the gas vent pin 8. , 8a and the inner peripheral surface of the pin insertion hole 12a provided in the lower die 12, the gas is discharged into the degassing cavity 9 below the pin insertion hole 12a.

The degassing cavity 9 is connected to a negative pressure pump (not shown) installed outside the mold, and by the action of the negative pressure pump (not shown), the mold corresponding to the porous portion is formed. The air that has flowed into the molding section is smoothly discharged to the outside of the mold 12 through the vertical grooves 8a, ..., 8a and the degassing cavity 9 without accumulating in the molding section. . That is, in this embodiment, the gas vent pin 8 and the negative pressure pump (not shown) constitute the gas vent mechanism described in claim 3 of the present application. On the other hand, when the molding resin material is polypropylene resin, it cannot pass through the gap of the above degree (0.01 to 0.02 mm) in the molten state, so that the molten resin may flow out of the mold. There is no.

Instead of using the gas venting pin 8 as described above in the gas venting mechanism, for example, as shown in FIG. 7, a metal mold corresponding to the perforated portion of the speaker grill is used, for example, porous metal such as sintered metal. A porous mold 23 made of a substance is mounted in the lower mold 12, and a gas in the molding cavity is discharged from a gas vent passage 24 provided on the back side of the porous mold 23.
It is also possible to discharge (air). in this case,
A negative pressure pump (not shown) may be connected to the gas vent passage 24 to vent gas. In addition, by flowing a fluid (for example, water) having a flow rate of a certain rate or higher through the gas vent passage 24, a negative pressure may be generated in the passage 24 so that the gas is vented.

Further, in this embodiment, the mold surface corresponding to the above-mentioned porous portion, that is, when the mold is clamped as shown in FIG.
In order to improve the releasability at the time of demolding after molding, for example, on the surfaces of the die-molding portions 11b, 12b having tooth-shaped cross-sections that contact each other at the mold splitting surface (see the broken line in FIG.
A plating treatment such as nickel alloy plating or chrome plating containing a powder of tetrafluoroethylene resin is performed. Further, a predetermined draft is provided in the tooth-shaped section of the die forming portions 11b, 12b. Incidentally, the speaker grill 5 is provided with a dummy portion 16 having a constant width along the periphery thereof. This dummy part 16
As can be seen from FIG. 5, is a portion that has a hole on the front surface side of the speaker grill 5 but does not penetrate to the rear surface side, and is provided along the outer peripheral rib 17 with a constant width inside thereof. Reinforcement along the periphery of the grill 5 can be performed.

By the way, in the present embodiment, when the resin speaker grill 5 and the door pocket trim 3 are integrally formed, the porous portion of the speaker grill 5 is made fine and has a high-class feeling, and there is a problem such as lack of thickness. In order to enable the molding without any occurrence, the hole diameter, the pitch, the maximum wall thickness between adjacent holes, etc. are set in the optimum range for the porous portion of the speaker grill 5, and the molding resin material is used. It is set so that the melt flow rate of (polypropylene resin) is above a certain level. Hereinafter, these set values will be described.

As is well known, the sound volume transmission characteristic of a speaker is determined by the aperture ratio of the porous portion of the speaker grill, that is,
The ratio of the total opening area of the opening holes per unit area in the speaker grill is affected, and it is usually necessary to secure an opening ratio of 40% or more in order to obtain good sound volume transparency. As shown in FIGS. 9 and 10, the aperture ratio β is such that the holes H, ..., H are arranged so that the distances between the centers of any three adjacent holes H are equal to each other.
When the hole diameter (hole inner diameter) of each hole H in the porous portion is D and the pitch is P, it is expressed by the following equation. β = {(D / 2) ² π · 1/2} / (P · P / 2 · 3 ^1/2 · 1
/ 2) Each hole H is formed by the molding part 1 having a tooth-shaped cross section of the molds 11, 12.
Corresponding to the drafts provided in 1b and 12b, both the front surface side and the back surface side are formed to have a tapered shape, but the hole diameter D adopts the value of the portion where the inner diameter is the smallest for each hole H. .

The value of the aperture ratio β when the hole diameter D is changed in the range of 1.5 to 2.3 mm and the pitch P is changed in the range of 2.1 to 3.2 mm by 0.1 mm, respectively. ,
It was calculated using the above formula. The calculation results are shown in Table 1.
In Table 1, the portion surrounded by the broken line has an aperture ratio β of 4
The area is 0% or more.

[0029]

[Table 1]

Further, Table 2 is adjacent to each other when the hole diameter D is changed within the range of 1.5 to 2.3 mm and the pitch P is changed within the range of 2.1 to 3.2 mm by 0.1 mm. The result of having calculated the maximum wall thickness B between holes is shown. This maximum wall thickness B is more advantageous for ensuring moldability as the value is larger, and when polypropylene resin is used as the molding resin material, if the value of B exceeds 0.8 mm, normal injection is performed. Even in molding, defects such as lack of thickness do not occur and molding can be performed without any problems, but as a speaker grill, the porous portion has a rough texture, the appearance is deteriorated, and the sense of quality is impaired. On the contrary, the smaller the value of the maximum wall thickness B is, the finer the porous portion becomes and the higher the sense of quality is obtained. However, when polypropylene resin is used as the molding resin material, the value of B is When the value is less than 0.6 mm, the flow of the molten resin becomes very bad, which tends to hinder the molding. Therefore, in this embodiment, the value of the maximum wall thickness B between the adjacent holes is set to be in the range of 0.6 to 0.8 mm. In Table 2, the range surrounded by the one-dot chain line is
It shows the region where the value of the maximum wall thickness B is 0.6 to 0.8 mm.

[0031]

[Table 2]

Regarding the value of the hole diameter D, the larger this value is, the more advantageous it is to secure the aperture ratio β. However, when the hole diameter D exceeds a certain value and becomes large, the speaker grill has a porous portion. It has a rough texture and deteriorates the appearance, impairs the high-class feeling, and foreign matter such as dust and dust easily mixes inside the speaker, which adversely affects the characteristics and durability of the speaker. There is a practical problem that this is also possible. Therefore, in this embodiment, the hole diameter D is set to 2.0 mm or less so that a finely textured porous portion can be obtained and a high-grade feeling can be obtained. Specifically, the hole diameter D is set to 1.8 mm, for example.

Further, with respect to the value of the pitch P, the larger this value is, the more advantageous it is to secure the formability. However, when the pitch P exceeds a certain value, the perforated portion of the speaker grill has a fine texture. It becomes rough and the appearance is deteriorated, and the high-class feeling is impaired. Therefore, in the present embodiment, the pitch P is set to 2.8 mm or less as a range in which a finely porous portion can be obtained and a high-quality feeling can be obtained. Specifically, this pitch P is 2.57 mm
And In Table 2, a region that satisfies all the setting conditions for the opening ratio β, the maximum wall thickness B between adjacent holes, the hole diameter D, and the pitch P is surrounded by a hatched frame.

Further, in this embodiment, more preferably, the detailed dimensional specifications of the porous portion of the speaker grill 5 are set as follows. That is, the gap A on the grill surface between the adjacent holes was set to 0.5 mm or more.
This is because if the interval A is less than 0.5 mm, it becomes extremely difficult to manufacture the mold, and this value becomes the limit value. The height E from the split surface to the grill surface and the height F from the grill back surface are both set to 0.6 mm or more. This is because if the heights E and F are less than 0.6 mm, the rigidity of the porous portion of the speaker grill 5 becomes too low, and the required rigidity value cannot be secured. Further, the draft angle θ on the grill surface side of the inner diameter portion of the hole H (that is, on the upper die 11 side) was set to 4.7 ° or more. This is because if the draft angle θ is less than 4.7 °, it will interfere with the die cutting after molding, and this value becomes the limit value.

Further, in this embodiment, sufficient moldability can be ensured without using a special injection molding method using a special mold apparatus such as the valve gate system described above. As the molding resin material (polypropylene resin), a material having a melt flow rate (hereinafter, abbreviated as MFR) of at least a certain level was used. As is well known, this MFR is one index for evaluating the fluidity of a molten resin material, and the larger this value, the richer the fluidity.

The door pocket trim 3 according to this embodiment.
Injection molding using various molding resin materials with different MFR values (all polypropylene resin),
Possibility of flowability and moldability of molten resin in the porous portion of the speaker grill 5 during molding (whether or not there is a wall deficiency)
I did a test to find out. Table 3 shows the type (product number) and MFR value of each molding resin material used in this test, and the test results. In addition, each molding resin material shown in Table 3
The manufacturers of (Material A to Material F) are as follows.・ Materials A, B, E and F: Mitsui Petrochemical Co., Ltd. ・ Materials C and D: Idemitsu Petrochemical Co., Ltd. Further, the MFR values of each material A to F in Table 3 are all measured in accordance with JIS K7210. It was done. Further, in the columns of "flowability" and "formability" in Table 3, ◯ indicates that they are good, and x indicates that they are defective.

[0037]

[Table 3]

As is clear from the test results in Table 3, M
When the FR value was 45 [g / 10 min] or more (materials D, E and F), the flowability of the molten resin in the porous portion of the speaker grill 5 was good, and the moldability was also good. From the above, as a molding resin material, the MFR value is 45 [g / 10
min] or higher polypropylene resin is used.

As described above, according to this embodiment, the hole diameter D, the pitch P, and the maximum wall thickness B between the adjacent holes B of the porous portion of the speaker grill 5 integrally formed with the door pocket trim 3. Was set as above,
It is possible to effectively suppress the entry of foreign matter such as dust and dust into the inside of the speaker, and it is possible to integrally form the speaker grill 5 with a fine porous portion and a high-class feeling. Further, since the aperture ratio of the porous portion is set to 40% or more, it is possible to ensure good sound volume transparency of the peaker grill. In this case, since polypropylene resin having a melt flow rate of 45 [g / 10 min] or more is used as the molding resin material, sufficient moldability is ensured when the speaker grill 5 and the door pocket trim 3 are integrally molded. As a result, molding can be performed without causing defects such as lack of thickness. Further, since the gas venting mechanism is provided on the back side of at least one of the molds (lower mold 12 in this embodiment) corresponding to the porous part, the air flowing into the mold forming part corresponding to the porous part is It is smoothly discharged to the outside of the lower mold 12 without accumulating in the mold molding portion, and the moldability can be ensured more reliably. Furthermore, since the mold surface corresponding to the above-mentioned porous portion is plated, it is possible to improve the releasability when the molded product (door pocket trim 3) is demolded after molding.

In the above embodiment, the speaker grill 5 is provided on the door trim 1 of the front door. However, the present invention is not limited to this case, and other interior trims, for example, FIG. As shown in FIG.
It is also effectively applied to the case where the rear package trim 33 made of resin disposed in the rear of the passenger compartment of the automobile 30 behind the rear seats is molded with the speaker grills 35, 35 for the rear speaker integrated. can do.

Further, it is needless to say that the present invention is not limited to the above embodiments, and various improvements and design changes can be made without departing from the scope of the invention.

[Brief description of drawings]

FIG. 1 is a perspective view of a vehicle door trim according to an embodiment of the present invention.

FIG. 2 is a perspective view of a door pocket trim of the door trim.

FIG. 3 is an explanatory view showing an arrangement of ejector pins and degassing pins when integrally forming a porous portion of the speaker grille according to the embodiment.

FIG. 4 is an explanatory view showing a part of FIG. 3 in an enlarged manner.

FIG. 5 is a vertical cross-sectional explanatory view of a mold molding portion corresponding to a porous portion of the speaker grill.

6 is an explanatory cross-sectional view in the XX direction of FIG.

FIG. 7 is a vertical cross-sectional explanatory view showing another embodiment of the gas venting mechanism.

FIG. 8 is an explanatory sectional view showing, on an enlarged scale, a surface portion of a mold molding portion corresponding to a porous portion of the speaker grill.

FIG. 9 is an explanatory plan view showing, on an enlarged scale, an opening hole in a porous portion of the speaker grill.

10 is a vertical cross-sectional explanatory view in the YY direction of FIG.

FIG. 11 is a vertical cross-sectional explanatory view of the hot runner used for forming the door pocket trim according to the above-described embodiment.

FIG. 12 is a perspective view of a rear portion of an automobile according to another embodiment of the present invention.

FIG. 13 is a perspective view of a rear package trim according to another embodiment.

[Explanation of symbols]

 3 ... Door pocket trim 5, 35 ... Speaker grill 8 ... Gas vent pin 11b, 12b ... Mold forming part 23 ... Porous mold 33 ... Rear package trim B ... Maximum wall thickness between adjacent holes D ... Hole diameter H … Hole P… Pitch

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Claims (3)

[Claims] 1. An interior trim in which a porous resin-made speaker grill is integrally formed at a predetermined location, wherein the interior trim has a hole diameter of 2.0 mm or less for each of the porous portions of the speaker grill. A polypropylene resin with a pitch of 2.8 mm or less, a maximum wall thickness between adjacent holes of 0.6 to 0.8 mm, and a melt flow rate of 45 [g / 10 min] or more as a molding resin material. An interior trim integrated with a resin speaker grill that is molded using. 2. A resin speaker grill integrated interior trim according to claim 1, wherein an aperture ratio of the porous portion of the speaker grill is set to 40% or more. 3. A molding die for molding an interior trim in which a porous resin-made speaker grill is integrally molded at a predetermined position, wherein the interior trim has holes for each of the porous parts of the speaker grill. The diameter is 2.0 mm or less, the pitch is 2.8 mm or less, the maximum wall thickness between adjacent holes is set to 0.6 to 0.8 mm, and the melt flow rate as the molding resin material is 45 [g / 10 min] or more is used for molding, and the mold surface corresponding to the above-mentioned porous portion is subjected to plating treatment, while at least one mold back surface corresponding to the above-mentioned porous portion is provided. Mold for interior trim with resin speaker grill integrated with a gas venting mechanism.