JP4602774B2 - Molded parts - Google Patents

Description

  The present invention relates to a technique for preventing sinking of a thick part in molding using a resin or the like. More specifically, the present invention relates to the matching of molded parts when a plurality of molded parts are combined into a finished product. The present invention relates to a shape of a surface and a forming method thereof.

FIG. 7 is a sectional view on the front end side (the side opposite to the mirror surface) of the door mirror 2, and shows a joint portion between the visor 4 which is a main body portion of the door mirror 2 and the cover 5 attached to the visor 4. The cover 5 is attached such that the lower edge 5 b of the periphery is in contact with the assembly surface 4 a of the visor 4. The resin cover 5 is formed by injection molding, and the lower edge portion 5b contacting the assembly surface 4a is formed thick for reinforcement.
When molding a molded part using a molding material such as resin, if the thickness of the part is not constant and uneven depending on the location, the shrinkage of the material during cooling will generally result in a `` sink '' in the thick part. The deformation called is easy to occur.
Therefore, the thick lower edge portion 5b has a larger material shrinkage than other portions, and the warped shape 5f due to “sink” is likely to occur. The warped shape 5f not only deteriorates the appearance, but also the wind w flowing on the surface of the door mirror 2 is disturbed by the warped shape 5f when the vehicle is running, thereby increasing air resistance and generating unpleasant wind noise. was there.
Further, in Patent Document 1 below, in molding a door mirror housing of an automobile, a portion having a large thickness where “sink” is likely to occur is made hollow by a gas-assisted injection molding method. ”Is disclosed.
JP-A-9-58345

However, the countermeasure in Patent Document 1 requires the introduction of equipment dedicated to the gas assist injection molding method. Moreover, in order to make the inside of the thick portion hollow, a certain amount of size (thickness) is required, and there are restrictions on the applicable locations.
In addition, since the interior is hollow, for example, in places where rigidity is required to apply a load, or in a continuous long thick shape, it is difficult to ensure dimensional accuracy with other loads applied. It was.
In view of the conventional problems, the present invention does not require a special molding facility, does not select the size of a location to be applied, and further, a location where rigidity is required to add a load or a continuous long thick shape However, it is an object of the present invention to provide a molded part for preventing “sink marks” that can ensure dimensional accuracy in a state where a load from other sources is applied.

In order to achieve the above object, a molded part of the present invention is a molded part formed by melting a molding material and flowing it into a mold, wherein the peripheral part of the molded part is provided in another part. A plurality of solids that are configured to abut against the attachment surface and protrude so as to secure the area of the surface that abuts against the assembly surface of the other component by partially increasing the thickness of the peripheral edge. Are formed on the peripheral edge, and the plurality of convex shapes are arranged apart from each other in the circumferential direction of the peripheral edge .
In the molded part of the present invention, when the molded part is molded , the plurality of convex shapes are arranged corresponding to the portion where the molding material injected from the molding material injection port in the molding die is finally filled. Has been .
In the molded part of the present invention, the molded part is configured as a design part, the surface of the molded part is configured as a design surface, and the plurality of convex shapes are disposed on the back side opposite to the design surface. It is . The design surface is a surface that appears in the appearance of the molded part.
In the molded part of the present invention, the molded part is a cover that constitutes a surface of the door mirror of the automobile facing the front of the vehicle body, and the injection port of the molding material is arranged on the vehicle upper side of the peripheral part of the cover The plurality of convex shapes are arranged on the vehicle lower side of the peripheral edge portion of the cover .

In the present invention, the shape in which the plurality of solid convex shapes are arranged apart from each other is arranged at a location where the molding material injected from the injection port of the molding material is finally filled.
As a result, the injection pressure of the material is difficult to be transmitted at the location where the molding material is finally filled, and the amount of filling is small, so that “sink” is likely to occur. Can be prevented.

In the present invention, a shape in which the plurality of solid convex shapes are arranged apart from each other is provided at a mating portion with another component.
In this way, in order to secure the area of the mating surface with other parts, even in the mating part that tends to be generally thick, against the load caused by other parts abutting while preventing “sinking” , Rigidity can be secured, and deformation and deterioration of the dimensional accuracy of the mating portion can be prevented.

Furthermore, in the present invention, a shape in which the plurality of solid convex shapes are arranged apart from each other is provided at a mating portion with another component, and is disposed at a position that is covered with the other component and cannot be seen from the design surface. ing.
This makes it possible to prevent “sinking” without affecting the appearance shape.
Further, in the present invention, the “sink” prevention technology is applied to a cover portion having a surface facing the front of a vehicle body of an automobile door mirror, and the injection port for the molding material is provided at an upper edge of the cover portion, A shape in which a plurality of solid convex shapes are arranged apart from each other is provided on the lower edge of the cover portion.

  Therefore, by providing the vicinity of the injection port of the molding material, where the amount of injection and the momentum of injection are relatively high, which is unlikely to cause “sinking”, at the upper edge of the cover portion, an easily visible upper appearance is ensured. be able to. In addition, even at the bottom of the cover part, which is far from the injection port and filled with the material at the end, by providing a shape in which a plurality of solid convex shapes are arranged apart from each other, the curved shape of the edge part due to “sink” Can be prevented from being formed. This warped shape not only deteriorates the appearance, but also disturbs the flow of air from the front of the vehicle, increasing the air resistance and generating an unpleasant wind noise. However, the application of the present invention can prevent this problem, improve the appearance, reduce the air resistance due to the smooth air flow, and prevent the generation of wind noise.

Molded part of the present invention is a molded part formed by flowing into the mold to melt the molding material, as the peripheral portion of the molded part, contact assembly surface and provided on the other part A plurality of solid convex shapes that are configured and protruded so as to ensure an area of a surface that abuts against an assembly surface of the other component by partially increasing the thickness of the peripheral edge portion. The plurality of convex shapes are spaced apart from each other in the circumferential direction of the peripheral edge.
This makes it possible to cope with ordinary injection molding without using a special molding method such as gas assist injection molding of the prior art. Compared to the conventional method in which a cavity is provided in the thick part, it is not necessary to ensure the thickness necessary for forming the cavity, so the degree of freedom of the application location is increased. Convex shapes arranged apart from each other are solid, not hollow, and each size is compact and stronger than conventional gas-assisted injection molding methods. When provided, it is difficult to be deformed even when subjected to a load caused by the contact of other components, and the dimensional accuracy of the mating portion can be ensured. Compared to conventional continuous thick portion, since there is provided a partially thick portion, it is possible to reduce the amount of the molding material, also resulting product weight reduction at the same time.

In the molded part of the present invention, when the molded part is molded, it corresponds to a portion (position opposite to the injection port) where the molding material injected from the molding material injection port in the molding die is finally filled. The plurality of convex shapes are arranged . In such places, the amount of material filling and injection pressure are difficult to be transmitted, so that “sinks” are likely to occur during molding, but “sinks” can be effectively prevented even in such places.
In the molded part of the present invention, the molded part is configured as a design part, the surface of the molded part is configured as a design surface, and the plurality of convex shapes are arranged on the back side opposite to the design surface since the prevention of "shrinkage" is possible without affecting the external shape.

In the molded part of the present invention, the molded part is a cover that constitutes a surface of the door mirror of the automobile facing the front of the vehicle body, and the injection port of the molding material is arranged on the vehicle upper side of the peripheral part of the cover The plurality of convex shapes are arranged on the vehicle lower side of the peripheral edge portion of the cover .
Therefore, when the door mirror is attached to the vehicle body by providing the vicinity of the injection port of the molding material, which is less likely to cause “sinking” due to the relatively large injection amount and injection momentum, on the vehicle upper side of the periphery of the cover. While it is possible to ensure the appearance of the upper side of the door mirror that is easy to stick to, the curvature of the peripheral edge due to “sinks” is also formed on the lower side of the cover that is far from the inlet and filled with the material at the end. Therefore, it is possible to reduce the air resistance due to the flow of air hitting the door mirror while the vehicle is running and to prevent the generation of wind noise.

As described above, in the present invention, a continuous thick portion where “sink marks” are likely to occur is formed by arranging a plurality of solid convex shapes apart from each other, in other words, the thick portion is partially provided with a concave shape. The shape prevents the occurrence of “sink marks”.
This makes it possible to cope with ordinary injection molding without using a special molding method such as gas assist injection molding of the prior art. In addition, compared to the conventional method of providing a cavity in the thick part, it is not necessary to ensure the thickness necessary for forming the cavity, so that the degree of freedom of application is high. In addition, the convex shapes arranged apart from each other are solid rather than hollow, and each size is compact, so that the strength is higher than the conventional one. Therefore, even when it is provided at a mating portion with another component, it is difficult to be deformed even if it receives a load caused by the contact of the other component, and the dimensional accuracy of the mating portion can be ensured.
Furthermore, compared with the conventional continuous thick part, the thick part remains partially, so that the amount of the molding material used can be reduced, and at the same time, an effect of reducing the weight of the product is produced.

Hereinafter, it demonstrates in detail using the example which applied the shaping | molding component by embodiment of this invention to the door mirror of a motor vehicle.
FIG. 1 is a perspective view of a vehicle having a door provided with a door mirror as viewed from the rear side, FIG. 2 is an enlarged view of the door mirror, and FIG. 3 is an exploded perspective view of the door mirror.
A door mirror 2 is attached to an outer front portion of the front door 1 a of the automobile 1, and the door mirror 2 mainly includes three parts: a mirror (mirror body) 3, a visor 4, and a cover 5. The substantially casing-like visor 4 accommodates the mirror 3 in an opening formed on the rear side of the vehicle body, and a cover 5 is attached on the front side. A substantially rectangular frame portion 4b is formed around the place where the mirror 3 is disposed, and an assembly surface 4a is formed in an opening formed in front of the frame portion 4b.

The cover 5 according to the present invention is formed by injection molding in the present embodiment, and has a smooth curved surface as a design surface 5a on the outside, and a plurality of portions to be attached to the visor 4 on the back surface side of the cover 5. A locking claw 5c is formed. The peripheral shape of the mating surface 5 g of the cover 5 is formed in a shape corresponding to the entire circumference of the assembly surface 4 a of the visor 4. When the cover 5 is attached to the visor 4, the mating surface 5 g is aligned with the assembly surface 4 a, and the locking claw 5 c is locked to a locking hole or an edge (not shown) formed in the visor 4. In a state in which these are assembled, the reference (front) surfaces of the frame 4b and the cover 5 are curved or planar with no step.
The mating surface 5g of the cover 5 is thicker than the lower edge portion 5 at the peripheral edge portion (upper edge portion and both side edge portions) excluding the lower edge portion 5b shown in FIG. In other words, in the mating surface 5g, the lower edge portion 5b is formed with the same thickness as the inner portion of the cover 5, and the peripheral edge portion of the mating surface 5g excluding the lower edge portion 5b is more than the inner portion of the cover 5. It is thick.

  An injection port 5e for injecting a molding material into the molding die when the cover 5 is molded is formed at the upper edge of the mating surface 5g inside the cover 5. The injection port 5e is a place where the molding material melted by the injection molding machine is injected into the cavity of the molding die. The injection port 5e is provided at the upper edge on the back side of the cover 5 because the injection pressure of the injection molding machine is high in the vicinity of the injection port 5e and the flow rate of the molding material to be filled is large. The part where the surface condition of the product is the best. Further, the upper edge portion of the cover 5 is easily visible when the cover 5 is attached to the door mirror 2, and therefore, it is desirable to place the injection port 5 e close to that portion.

On the other hand, in the lower edge portion 5b far from the injection port 5e, the injection pressure is difficult to be transmitted and the flow rate of the molding material to be filled is small, so that “sinking” easily occurs on the other mating surfaces 5g.
Therefore, in the present embodiment, the mating shape of the lower edge portion 5b is not a continuous thick-walled shape like the both edge portions of the upper edge portion of the mating surface 5g, and a plurality of solid convex shapes 5bb are separated from each other. And arranged in a line.
As shown in FIGS. 4 and 5, a plurality of triangular convex shapes 5bb are provided along the lower edge portion 5b on the back surface side of the cover 5 so as to protrude toward the visor 4 side. Further, on the visor 4 side, in addition to the lower edge portion 5b of the cover 5, a contact surface 4c serving as a receiving surface of the convex shape 5bb is formed. In the present embodiment, the protruding height of the convex shape 5bb is made smaller than the thickness of the lower edge portion 5b. FIG. 6 shows a joint portion between the visor 4 and the cover 5 at a portion where the convex shape 5bb is not formed. As shown in this joint portion, the thickness of the lower edge portion 5b of the cover 5 is the same as the inner thickness thereof, and the end surface of the lower edge portion 5b and the assembly surface 4a are brought into contact with each other. Yes.
The number of convex shapes 5bb is not particularly defined. In this embodiment, three convex shapes 5bb of 5 to 8 mm are arranged in the range of the lower edge portion 5b of 155 mm. However, if the rigidity and area necessary for forming the assembly surface with the visor 4 can be secured. It is preferable that the number is as small as possible and the size is small.

  With such a configuration, when the cover 5 is molded by an injection molding machine, the material at the upper and side edges of the cover 5 is relatively close to the injection port 5e serving as the material injection port in the mold due to the pressure during injection. Even if it spreads and forms a compact part, sink marks are unlikely to occur. Further, as shown in FIG. 6, the lower edge portion 5 b where the pressure is relatively weak is thin, so that there is no sink. Further, the thickness of the convex shape 5bb changes, but the size of the convex shape 5bb is not small and continuous, and the convex shape is also small, so that the shrinkage rate of the molding material is suppressed as shown in FIG. Can prevent the occurrence of “sink”.

In addition, since the convex shape 5bb is hidden inside the mating portion when the visor 4 is assembled, even when the door mirror 2 is looked into from below, the visor 4 and the cover 5 are designed in appearance. The surface is in a smooth and continuous state.
In the conventional method, since the thick-walled matching shape (see the two-dot chain line portion in FIG. 3) is provided over the entire lower edge portion 5b, the material contraction is large compared to other portions, As shown in FIG. 7, the warped shape 5 f due to “sink” was likely to occur at the edge. This warping not only deteriorates the appearance but also causes the wind flowing on the surface of the door mirror 2 to be disturbed by the warping shape 5f when the vehicle 1 is running, thereby increasing air resistance and generating unpleasant wind noise. It was. However, according to the present invention, the occurrence of the warped shape 5f can be prevented and it can be smoothly connected to the surface of the visor 4, so that the appearance is improved and the flow of wind is smoothly guided, air resistance is reduced, and wind noise is prevented. can do.
Therefore, the injection port 5e is provided in the vicinity of the upper surface, and it is possible to secure a preferable shape with respect to the air flow at the lower end while improving the design of the portion that is easily noticeable.

Although the embodiments of the present invention have been described above, the present invention is of course not limited thereto, and various modifications and changes can be made based on the technical idea of the present invention.
When a plurality of molded parts are combined into a finished product, the present invention can be applied particularly when it is necessary to improve the external appearance of the part due to unpainted resin parts.
Although the molded part has been described with the cover of the door mirror, it can be applied to other molded parts as long as it is a resin material.

It is a perspective view from the back of the motor vehicle provided with the door mirror which employ | adopted the molded component by embodiment of this invention. It is an enlarged view of the door mirror of the motor vehicle of FIG. It is a disassembled perspective view of the door mirror of the motor vehicle of FIG. FIG. 4 is an enlarged perspective view of a convex shape in a circle indicated by arrow X in FIG. 3. It is sectional drawing of the AA line direction of FIG. It is sectional drawing of the BB line direction of FIG. It is sectional drawing which shows the connection part of the visor and cover of the conventional door mirror.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car 2 Door mirror 3 Mirror 4 Visor 4a Assembly surface 5 Cover 5a Design surface 5b Lower edge 5bb Convex shape 5e Inlet 5g Mating surface

Claims (4)

In molded parts formed by melting the molding material and flowing it into the mold,
The peripheral part of the molded part is configured to come into contact with an assembly surface provided in another part,
A plurality of solid convex shapes are formed on the peripheral portion so as to project the area of the surface that contacts the assembly surface of the other component by partially increasing the thickness of the peripheral portion. ,
The molded part , wherein the plurality of convex shapes are spaced apart from each other in the circumferential direction of the peripheral edge . The plurality of convex shapes are arranged corresponding to a location where the molding material injected from the injection port of the molding material in the molding die is finally filled when molding the molded part. The molded part according to claim 1. The molded part is configured as a design component, the and the surface of the molded part is configured as a design surface, and the plurality of convex shape is protruded from the back surface opposite to the said design surface, wherein Item 3. The molded part according to Item 1 or 2. The molded part is a cover that constitutes a surface facing the front of the vehicle body of an automobile door mirror ,
The injection port of the molding material is disposed on the vehicle upper side of the peripheral edge of the cover,
Wherein the plurality of convex shape, characterized in that it is arranged on the vehicle lower side of the peripheral edge of the cover, the molded part according to any one of claims 1-3.

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