JP2001239544A - Resin part having skin and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin part enhanced in the appearance quality of the parting part of its skin layer and reduced in impingement sound without altering a mold structure. SOLUTION: In a method for manufacturing the resin part wherein the boundary part of a skin and a base material is exposed on a design surface, the skin 2 is arranged in a mold and, when the base material integrated with the rear surface of the skin 2 is formed by injection molding, an elastic projected part 22 is formed on the rear surface of the skin in the vicinity of the boundary line 12 so as to be projected on the rear surface side of the skin to come into contact with the other molding surface of the mold and injection molding is performed in such a state that the elastic projected part 22 is compressed by the mold. Since the skin 2 is brought into contact with the molding surface of the mold under pressure by the elastic projected part 22 to be sealed, the leak of a resin is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin part having a skin, such as an instrument panel of an automobile, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Interior parts such as an instrument panel of an automobile need to have both strength and soft touch, so that a hard resin base material and a soft skin layered on the base material surface are required. It is composed of As the epidermis, those made of soft PVC or TPO are predominant, and urethane or P is used to give a soft touch.
In many cases, a foam layer such as P is interposed between the skin layer and the base material.

In order to manufacture such a resin part, a skin layer is formed into a predetermined shape by vacuum forming, a base material is formed by injection molding or the like, and the formed skin and the base material are placed in a mold. There is a method of arranging and foaming the foam layer.

However, this method requires three molds, one for forming a shaped skin, one for forming a base material, and one for forming a foam layer. However, there is a problem that the cost required for the method becomes a problem and the number of steps is increased.

[0005] For this purpose, first, a skin layer and a foam layer are laminated, and then shaped into a predetermined shape by vacuum molding or the like to obtain a shaped body.
A method of arranging the shaped body in a mold and molding a base material by injection molding or the like is also known. However, even with this method, a vacuum forming step is required, and the number of steps is increased.

Therefore, in recent years, a skin layer is first formed by injection molding, and then the foam layer is formed by slightly opening the other mold with the skin layer adhered to the mold surface, and then separating the other mold. A method of extruding a base material by exchanging the mold with another mold has been studied. According to this method, since all can be formed by injection molding and one of the molds can be shared, the cost and man-hours of the mold can be greatly reduced.

[0007]

[0005] By the way, in a resin part used as an interior part of an automobile, a part of an end portion of a skin layer and a foam layer on a design surface is buried in the base material, and the skin layer and the base material are formed. Are exposed. In such a resin part, it is necessary to clearly form the parting part of the skin layer, otherwise the appearance quality will be greatly reduced.

However, in a method in which a skin layer and a foam layer are arranged in a mold and a substrate is formed by injection molding,
Since both the skin layer and the foam layer are soft, the ends may be deformed by the pressure of the molten resin forming the base material, and the resin may enter the interface between the skin layer and the mold surface from the ends. In this case, resin leakage occurs at the parting portion of the skin layer, resulting in poor appearance quality, and a step of cutting off the resin that has protruded by manual work or the like is required, resulting in a large number of steps.

As described in JP-A-8-300380, JP-A-10-109333, etc., such a problem occurs when the skin layer and the foam layer are firmly held in a mold. This can be prevented by injection molding the substrate. Alternatively, as shown in FIG. 8, a groove 101 is formed in the base material 100 at the parting-off portion, and the ends of the skin layer 200 and the foam layer 300 are sealed in the groove 101. In this way, even if resin leakage occurs, the groove 101
Because it fits inside, it is possible to hide the leaked resin.

However, in order to firmly hold the skin layer and the foam layer in the mold, it is necessary to improve the mold structure, and there is a problem that the mold cost increases. Groove 1
In the case where 01 is formed, the groove 101 is exposed, so that the appearance is poor, and there is a problem that dust or the like enters the groove 101 so that it is easily stained.

Further, in the conventional resin parts, since the back side is formed only of the hard base material surface, a collision sound may be generated when other parts such as a harness and an air conditioner unit interfere with each other due to vibration or the like. Since such a collision sound contributes to vehicle interior noise, it is desirable to further suppress the collision sound. However, forming a soft sound absorbing material or the like on the surface of the base material in order to reduce the impact sound has problems in terms of man-hours and costs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a resin part in which the appearance quality of a parting portion of a skin layer is improved and collision noise is reduced without changing the mold structure. The purpose is to:

[0013]

Means for Solving the Problems The features of the method for producing a resin part having a skin according to the present invention that solves the above-mentioned problems are that a resin base material and a soft and elastic skin material laminated on the surface of the base material are provided. A method for producing a resin component comprising a design surface, wherein a part of an end of a skin is buried in a base material and a boundary between the skin and the base material is exposed, wherein the soft and elastic skin source is provided. Forming a base material into a predetermined shape to form a skin, and forming a base material integrated with the back surface side of the skin by injection molding by arranging the skin in a mold along one mold surface. The back surface of the skin has an elastic protrusion protruding toward the back surface in the vicinity of the boundary portion and abutting against the other mold surface of the mold, and the injection molding is performed in a state where the elastic protrusion is compressed by the mold. .

The resin component of the present invention manufactured by the above manufacturing method is characterized by comprising a resin base material and a soft and elastic skin layered on the surface of the base material. A part of the part is a resin component in which the boundary between the skin and the base material is exposed by being buried in the base material, and the base material has a through hole penetrating in the thickness direction near the boundary part, A part of the skin covers the inside of the through-hole and is exposed on the back side of the base material.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the manufacturing method of the present invention, the back surface of the skin has an elastic protrusion protruding toward the back surface near the boundary and abutting on the other mold surface, and the elastic protrusion is formed of metal. The base material is formed by injection molding in a state where the base material is compressed. That is, since the elastic convex portion is compressed by the mold, the surface of the skin at a position opposite to the elastic convex portion is pressed against the mold surface by an elastic reaction force to be sealed, and the boundary portion, that is, the skin is cut off. The sealing pressure of the part increases. In addition, since the rigidity of the skin near the boundary is improved by the elastic convex portion, the deformation of the skin is less likely to occur. Due to these synergistic effects,
The molten resin is prevented from leaking to the surface of the skin during injection molding.

Therefore, according to the manufacturing method of the present invention, a substrate can be formed using a conventional mold as it is,
There is no increase in mold cost. In addition, since a post-processing step is not required, the cost of the obtained resin component can be reduced.

In the resin component of the present invention manufactured by the above-described manufacturing method, the elastic projection penetrates the base material and the elastic projection is exposed on the surface of the base material. In addition, since the elastic convex portion is in a compressed state at the time of molding of the base material, after releasing the resin component, it tries to restore to its original shape by elastic reaction force, and the surface of the elastic convex portion rises from the surface of the base material State.

Therefore, in the resin component of the present invention, even if another component such as a harness interferes during use, the collision noise can be reduced by arranging the other component so as to interfere with the surface of the elastic convex portion. In addition, if the elastic projections are formed of a foam, a sound absorbing effect is also exerted by the exposed elastic projections, so that the collision sound can be further reduced. Furthermore, the synergistic effect of the sound insulation effect of the base material and the sound absorption effect of the elastic protrusions can effectively suppress the noise and the like of the engine room from entering the vehicle interior, thereby improving the quietness of the vehicle interior.

In the step of shaping the skin source into a predetermined shape to form the skin, for example, the skin layer is shaped in advance by vacuum molding or the like, and the skin layer is placed in a mold and a soft elastic material is provided on the back side of the skin layer. This can be done by integrally molding the layers. Alternatively, it is also possible to use a skin source in which a skin layer and a soft elastic layer are laminated in advance by a laminating method or the like, and form the skin into a predetermined shape by vacuum molding or press molding.

Further, a skin source having a predetermined shape is formed by injection molding from a soft resin material to which a chemical foaming agent has been added, and then the inside of the skin source is foamed by opening a mold at a predetermined interval to form a soft elastic layer. You can also. According to this method, a skin formed of a skin layer and a soft elastic layer and shaped into a predetermined shape can be manufactured by one injection molding.

When a skin composed of a skin layer and a soft elastic layer is used, a skin layer made of PVC or TPO can be used.
The soft elastic layer may be a soft foam layer formed of urethane foam, foam PP, foam rubber, or the like, or a soft solid layer formed of an elastic body such as rubber or thermoplastic elastomer.

The elastic projections formed on the skin protrude to the back side near the boundary between the skin and the base material and come into contact with the other mold surface, and are compressed by the die during the injection molding of the base material. It is formed as follows. The elastic projection may be in the form of a protrusion or a bank. Further, it is particularly desirable to form it at a site where resin easily leaks, and the number is not particularly limited. The elastic projections may be formed integrally with the skin, or may be formed separately and attached to a predetermined surface on the back side of the skin.

The height of the elastic projection is about 1.01 to about 1.01 of the clearance between the mold surfaces when molding the base material.
It is desirable that the height be about 2.00 times. If the elastic projection is too low, the amount of compression at the time of mold clamping decreases, and the sealing pressure decreases, so that resin leakage easily occurs. On the other hand, if the height of the elastic protrusion is too high, the elastic protrusion may be easily deformed in a direction other than the height direction due to the stress caused by the compression during mold clamping, and the resin may leak more easily. In order to prevent such a problem, it is also preferable that the height of the elastic convex portion is formed so as to gradually change from the general portion. This can prevent deformation toward the gradually changing portion during compression, and can regulate the direction in which the elastic projection deforms.

When a plurality of elastic projections are provided, the flow of the molten resin at the time of molding the base material differs depending on the presence or absence of the elastic projections. May act locally. In such a case, a defect such as wrinkling of the skin is likely to occur, and it is conceivable that resin leakage may occur at that portion.

Therefore, it is desirable to form a thin partition between the elastic protrusions and connecting the elastic protrusions at the same height as the elastic protrusions. In this case, since the flow of the resin is regulated by the partition, the above-described problem can be avoided. Then, when the resin reaches the entire elastic convex portion and the partition, the partition is broken by the resin pressure, and the molten resin passes through the partition at the final stage of molding and is filled at the tip, so an excessive pressure is applied to the tip. It is prevented from acting on the epidermis. It is also preferable that a notch or the like is formed in the partition wall so that the partition wall is easily broken.

[0026]

The present invention will be described below in detail with reference to examples. In this embodiment, the present invention is applied to an instrument panel of an automobile (hereinafter referred to as an instrument panel).

(Embodiment 1) FIG. 1 is a sectional view showing a main part of an instrument panel manufactured by the manufacturing method of this embodiment. This instrument panel includes a substrate 1 made of PP and a TP laminated on the surface of the substrate 1.
And a skin 2 made of O (thermoplastic olefin). The skin 2 has a structure in which a solid skin layer 20 is formed on the entire surface and a foam layer 21 is encapsulated inside. The skin layer 20 is soft and has a good tactile sensation, and becomes elastic by the presence of the foam layer 21. Rich.

The skin 2 has a tip portion buried in the base material 1, and a boundary line 12 between the base material 1 and the skin 2 is exposed. Also skin 2
At a position corresponding to the boundary line 12, a plurality of elastic projections 22 protruding to the rear surface side are arranged in rows at intervals, and are exposed from the through holes 10 of the base material 1 to the rear surface side. The surface of the elastic projection 22 exposed from the substrate 1 is slightly raised from the surface of the substrate 1. There is no gap between the base material 1 and the skin 2, and the boundary line 12 is formed very finely.

Hereinafter, a method for producing the instrument panel will be described.
Instead of a detailed description of the configuration.

First, a TPO to which a chemical foaming agent was added was used as a molding material, and a substantially plate-like molded body having a predetermined instrument panel shape and a substantially uniform thickness was formed by injection molding. Next, the mold was opened at a predetermined interval while the inside of the molded body was in a molten state, and the inside of the molded body was foamed. Thus, the skin 2 comprising the skin layer 20 and the foam layer 21 and having a predetermined shape and having the elastic projections 22 at predetermined positions was manufactured.

The obtained epidermis 2 is shown in FIG. 2 and FIG.
A plurality of the elastic protrusions 22 are arranged at intervals on the back surface side of the skin 2 along the boundary line 12. The thickness (t) of the portion where the elastic protrusion 22 exists is formed so as to be 1.05 times the clearance between the mold surfaces of the mold described later.

Next, the outer skin 2 is arranged at a predetermined position between the pair of fixed molds 30 and the movable mold 31 as shown in FIG. 4, and the fixed mold 30 and the movable mold 31 are clamped. Since the thickness (t) of the portion where the elastic convex portion 22 exists is 1.05 times the clearance between the mold surfaces of the fixed mold 30 and the movable mold 31, the elastic convex portion 22 is compressed by the mold clamping. Due to the elastic reaction force, the surface of the skin 2 opposite to the elastic convex portion 22 is strongly pressed against the mold surface of the movable mold 31.

In this state, the molten resin 4 is injected between the skin 2 and the mold surface of the fixed mold 30 as shown in FIG. The molten resin 4 that has reached the position of the elastic protrusions 22 proceeds further forward between the elastic protrusions 22 and flows into the cavity where the skin 2 does not exist. At this time, the outer skin 2 is
2 is strongly pressed against the mold surface of the movable mold 31,
In addition, the end of the skin 2 is thickened by the presence of the elastic projections 22 to increase rigidity. Therefore, the molten resin 4
Is prevented from entering between the surface of the skin 2 and the mold surface of the movable mold 31 at the end of the skin 2.

After the cavity is filled with the molten resin 4 and cooled and solidified, the movable mold 31 is opened from the fixed mold 30 and the instrument panel is released. Then, since the compression from the mold surface is released, the elastic convex portion 22 slightly protrudes from the through hole 10.

In the instrument panel thus obtained, no resin leaks from the boundary between the base material 1 and the skin 2, and the boundary line 12
Is formed finely and has high appearance quality. Therefore, a post-processing step such as a step of cutting off the leaked resin is unnecessary. In addition, the fixed mold 30 and the movable mold 31 can use the conventional molds as they are, and can suppress the mold cost.

In the instrument panel of this embodiment, the elastic projections 22 are exposed on the back side of the substrate 1, and the surface of the elastic projections 22 slightly protrudes from the surface of the substrate 1. Therefore, when this instrument panel is used in an automobile,
The other parts such as the harness and the air conditioner unit arranged on the side interfere with the exposed elastic protrusions 22, so that even if the base material 1 interferes with the other parts due to vibration or the like, the other parts are elastically connected. Interference with the convex portion 22 can be obtained, and the collision sound at the time of interference can be reduced. This improves the quietness of the vehicle interior.

Further, the sound insulation effect of the base material 1 and the elastic projections 2
Due to the synergistic effect of the sound absorbing effect of the second embodiment, it is possible to effectively suppress the noise of the engine room from entering the vehicle interior, thereby improving the quietness of the vehicle interior.

(Embodiment 2) FIG. 6 is a sectional view of a main part of the skin 2 used in this embodiment. The skin 2 is made of an elastic convex portion 22.
The second embodiment is the same as the first embodiment except that it has a gradually changing portion 23 whose thickness gradually increases toward.

In the manufacturing method of this embodiment, when the elastic convex portion 22 is compressed at the time of mold clamping or when the base material 1 is formed, the elastic convex portion 22 is moved rearward (the skin 2 (The side opposite to the tip of the front end) is prevented from being deformed so as to bend. In addition, due to the presence of the gradually changing portion 23, the epidermis 2
Has an even higher rigidity. Therefore, epidermis 2
The contact pressure between the tip of the mold and the mold surface is further increased, so that resin leakage can be further prevented.

(Embodiment 3) FIG. 7 is a perspective view of a main part of the skin 2 used in this embodiment as viewed from the back. This laminated product has the same configuration as that of the first embodiment except that thin partition walls 24 connecting the elastic protrusions 22 at the same height as the elastic protrusions 22 are formed. Notches 25 extending in the height direction of the partitions 24 are formed in the partitions 24.

In this embodiment, the molten resin 4 is
When the resin reaches the position, the presence of the partition wall 24 makes it difficult for the molten resin 4 to move forward from the elastic projection 22. Therefore, the molten resin 4 uniformly fills all the cavities up to the elastic projections 22 and the partition walls 24. Then, since the pressure of the molten resin 4 in contact with the partition wall 24 increases, the partition wall 2
4 is broken by a notch 25, whereby the molten resin 4 is allowed to pass through the partition wall 24, and the molten resin 4 flows into a cavity where the skin 2 does not exist. This prevents local excessive pressure from acting on the end of the skin 2,
The problem that wrinkles and the like are generated on the surface is prevented.

At this time, since the temperature of the molten resin 4 has decreased to some extent and the viscosity has increased, the molten resin whose pressure has decreased due to the flow resistance enters the front cavity. Therefore, compared to the first and second embodiments,
The molten resin can be further prevented from entering between the surface of the skin 2 and the mold surface of the movable mold 31, and leakage of the resin can be further prevented.

In this embodiment, the partition 24 is formed by the elastic projection 2.
2, but may be provided inside. Partition wall 2
If the thickness of the notch 4 is sufficiently small, the notch 25 may not be necessary, and the direction in which the notch 25 extends is not particularly limited.

In the above embodiment, the skin 2 having the sandwich structure having the foam layer 21 inside is used. However, the skin is not limited to this structure, and various skins may be used as long as they are soft and elastic. be able to.

[0045]

That is, according to the resin part having a skin of the present invention, the parting portion between the skin layer and the base material is fine, and the appearance quality is excellent. Since the elastic convex portion is exposed on the back surface side of the base material, it is possible to reduce a collision sound due to interference with other components, and to have a sound absorbing effect.

According to the manufacturing method of the present invention, it is possible to easily and stably manufacture the above-described resin parts having excellent appearance quality without changing the conventional mold, and the mold cost and the number of man-hours are increased. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a resin component (instrument panel) according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a skin used in the manufacturing method according to one embodiment of the present invention.

FIG. 3 is a perspective view of a main part of a skin used in the manufacturing method according to one embodiment of the present invention.

FIG. 4 is a cross-sectional view of a main part showing a state in which a skin is arranged in a mold in the manufacturing method according to one embodiment of the present invention.

FIG. 5 is a cross-sectional view of a main part showing a state where a base material is being formed by injection molding in the manufacturing method according to one embodiment of the present invention.

FIG. 6 is a sectional view of a main part of a skin used in a manufacturing method according to a second embodiment of the present invention.

FIG. 7 is a perspective view of a main part of a skin used in a manufacturing method according to a third embodiment of the present invention.

FIG. 8 is a sectional view of a main part of a conventional resin component (instrument panel).

[Explanation of symbols]

1: base material 2: skin
4: molten resin 10: through hole 12: boundary line 2
0: skin layer 21: foam layer 22: elastic projection 2
3: Gradual change part 24: Partition wall 25: Notch

Claims (3)

[Claims] 1. A base material made of a resin, and a soft and elastic skin layered on the surface of the base material, and a part of an end of the skin is buried in the base material on a design surface. A resin part in which a boundary between the skin and the base material is exposed, wherein the base material has a through hole penetrating in a thickness direction in the vicinity of the boundary, and a part of the skin is formed through the through hole. A resin part having a skin, wherein the resin part fills the holes and is exposed on the back side of the base material. 2. A base material made of a resin, and a soft and elastic skin layered on the surface of the base material, and a part of an end of the skin is buried in the base material on the design surface. A method for producing a resin component in which a boundary between the skin and the base material is exposed, wherein a step of shaping a soft and elastic skin source into a predetermined shape to form the skin, Forming the base material integrated with the back side of the skin by injection molding in a mold so as to be along the mold surface of the skin. A method of manufacturing a resin part having a skin, comprising: an elastic projection projecting from the mold and abutting against the other mold surface of the mold, wherein the elastic projection is injection-molded in a state compressed by the mold. . 3. A plurality of elastic protrusions are provided, and a thin partition wall connecting the elastic protrusions at the same height as the elastic protrusions is formed between the elastic protrusions. The method for producing a resin part having a skin according to claim 2, characterized in that: