JPH0482088B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a cross-integrated injection molded article,
In particular, the present invention relates to a structure that eliminates the problem of resin flow in a molded body in which a hole is formed in a part of the molded body.

[Prior Art] Recently, in automotive interior materials, there has been a tendency to use resin molded products with a cloth attached to the surface, especially in order to improve the appearance design.

As a means for attaching the cloth to this resin molded product, for example, there is a method using injection molding means.

To explain the outline of this molding method, first, a cloth is set in the cavity of an injection mold,
Subsequently, after the mold is clamped, a molten thermoplastic resin is injected into the cavity and integrated with the cloth to obtain a laminate molded product in which both are integrated.

With this technology, it is necessary to equalize the flow of the resin and to equalize the elongation of the cloth located on the surface of the resin, and it is necessary to set the gate at the center of the back surface of the molded product.

[Problems to be Solved by the Invention] However, as shown in FIG. 6, for example, when it becomes necessary to form a square hole 2 in a corner of a molded product 1 for placing a finger, The molten resin flowing from the gate 3 set at the center to each part joins at a corner part 1a of the molded product on the opposite side of the square hole 2 from the gate 3. Therefore, a weld line WL is generated at the confluence point, causing turbulence in the resin flow and applying a large load, resulting in a large tensile force on the back side, that is, the cross (not shown) on the surface of the molded product. As a result, wrinkles occur in these, which causes poor appearance.

The present invention has been made in view of the above problems, and by alleviating the sudden change in resin flow at the hole forming site, it is possible to eliminate the wrinkles of the cloth that is integrally attached to the surface, and the appearance of the product. The object of the present invention is to provide a cross-integrated injection molded body that can improve the

[Means for Solving the Problems] In order to achieve the above-mentioned object, this invention lays a cloth in the cavity of an injection mold, and after the mold is clamped, injects molten resin into the cavity through a sprue and a gate, A cross-integrated injection-molded product that is molded by integrating the cloth onto the surface,
In a molded body having a shape in which a hole is formed at a position away from a gate of the molded body, and resin flowing from the gate flows from both sides of the hole and merges at the periphery of the hole at a portion on the opposite side from the gate. , a thin-walled bridging portion for resin flow connecting the gate side and the opposite side portion is formed at least in the central portion of the hole, and the resin flowing from the gate side is connected to both sides of the opposite side portion of the hole and the bridge portion; I made it so that it joins from three sides of the hanging part.

[Function] According to the above configuration, in addition to the conventional case where the flowing resin merges from two directions at the portion of the periphery of the hole opposite to the gate, it also flows through at least the thin-walled bridging portion provided in the center of the hole. However, since the weld lines merge from three directions in total, the weld lines at the merged portion are dispersed, and the tensile force on the cloth is accordingly reduced, reducing the degree of wrinkling on the product surface.

Since the thin-walled bridging portion is cut together with the cloth covering the surface of the hole in the secondary processing step after the product is demolded, even if the bridging portion is provided, it does not affect the shape of the product.

[Example] Hereinafter, an example of the present invention will be described in detail using the drawings.

1 to 4 show a first embodiment of the present invention, FIG. 1 is a perspective view showing the overall structure of the cross-integrated injection molded article according to the present invention, and FIG. It is an enlarged sectional view of part A.

In this example, the cross-integrated injection molded product was applied to a glove box slide in the form of a rectangular shallow container. This lid 10 includes a resin molded body 12 forming a core material, and a resin molded body 12 that forms a core material.
A skin material 14 is laminated on the surface of the material.

This resin molded body 12 is made of polypropylene resin,
Thermoplastic resins such as polyethylene resin, polyamide resin, and ABS resin are used.

The skin material 14 is a laminate of a cloth 16, a plastic foam 18 and a knitted fabric 20 laminated on the back surface of the cloth 16.

More specifically, the cloth 16 is preferably a cloth with good elongation, and materials such as sinker pile, tricot, jersey, etc. made of polyester or nylon satisfy this condition, and the elongation rate of these cloths at the breaking point is 100 to 100. A value of 150% is desirable.

On the other hand, the plastic foam 18 has a density of
0.02~0.04g/ ^cm3 is suitable, and its elongation rate is
It is 200-400%. The material may be appropriately selected from polyurethane foam, polyethylene foam, polypropylene foam, etc.

Furthermore, the above-mentioned knitted fabric 20 is preferably one having high elasticity and good heat resistance, such as woolly nylon, and has a basis weight of 100 g/m ² or less, preferably 15 to 60 g/m ² .

The skin material 14 consisting of the three layers of the above material structure is laminated together by fusion or adhesive means. In particular, the skin material 14 laminated with the stockinette 20 has a property that the elongation rate varies depending on the fiber direction of the original fabric, that is, it has anisotropy, and a gate 12a formed in the center of the resin molded body 12
The elongation rate is adapted to the length depending on the direction of resin flow.

Note that the knitted material 20 is not necessarily an essential material, and by appropriately setting molding conditions such as molding temperature and molding pressure during injection molding and appropriately selecting the material for the cloth 16, the knitted material 20 can be
Even without it, it is possible to perform molding according to the appropriate elongation rate and resin fluidity.

A plurality of ribs 12b protruding from the surface of the molded body 12 are integrally formed on the inner surface of the lid 10, and a plurality of hinges 12c are integrally formed on one edge of the lid 10 in a state protruding from the surface. is formed.

A locking mechanism (not shown) is attached to the central corner 10a of the lid 10 on the side opposite to the hinge 10c, and a square hole 22 is formed into which a finger can be inserted to open and close the lid.

Of course, during molding, the square hole 22 is covered with the skin material 14, and only a concave portion is formed with a concave surface side depending on the shape, and this portion is punched out using a punch press or the like after demolding the molded product. The square hole 22 may be formed as described above.

The shape of the square hole 22 before punching is different from the conventional one, and as shown in FIG.
The corner portion 10a of the lid 10 is formed in communication with the corner portion 10a of the lid 10.

By adopting this shape, the square hole 22 can be passed through the molten thermoplastic resin gate 12.
When the fluid flows toward the periphery of the corner 10a, as shown by the arrows in FIG. 4, it flows toward both the corners 10a and at the same time flows along the hook 26, converging at the corner 10a from three sides.

Therefore, the weld line WL is not very conspicuous, and sudden changes in flow at this location are unlikely to occur.

Next, FIG. 5 shows a second embodiment of the present invention.

In this embodiment, the bridging portion 30 is formed in a thin shape over the entire surface of the square hole 22.

Therefore, even in this embodiment, the corner 10a
It flows from three directions. In addition, in this embodiment, since the resin flows over the entire surface of the square hole 22 toward the corner, the thickness of the bridging portion 30 can be made thinner than in the previous embodiment, making it easier to punch out in the subsequent cutting process. It's easy to do.

[Effects of the Invention] As explained in detail through each of the embodiments above,
In this invention, in addition to the conventional case in which the flowing resin flows from two directions at a portion of the periphery of the hole opposite to the gate, it flows at least through a thin-walled bridging portion provided in the center of the hole. Since the weld lines join from three sides, the weld line at the joining part is dispersed, which reduces the tensile force on the cloth, reduces the degree of wrinkling on the product surface, and improves the product appearance. do.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, FIG. 1 is an overall perspective view showing an embodiment of a cross-integrated injection molded body when the present invention is applied to a glove box, and FIG. is an enlarged sectional view of part A in FIG. 1, FIG. 3 is a partially sectional perspective view showing the shape of the square hole before press punching, FIG. 4 is a diagram for explaining resin flow near the square hole, FIG. 5 is a partially sectional perspective view showing a second embodiment of the present invention, and FIG. 6 is a diagram for explaining resin flow near a square hole in a conventional cross-integrated injection molded body. DESCRIPTION OF SYMBOLS 10... Glove box slid (cross integrated injection molded body), 10a... Corner, 12... Molded body, 12a... Gate, 14... Skin material, 16...
...Cross, 22...Square hole, 26, 30...Bridge part.

Claims (1)

[Claims] 1. A cross-integrated injection molded product that is formed by laying a cloth inside the cavity of an injection mold, and after the mold is clamped, molten resin is injected into the cavity through a sprue and a gate, and the cloth is integrated into the surface. , a molded body having a shape in which a hole is formed at a position away from a gate of the molded body, and resin flowing from the gate flows from both sides of the hole and merges at the periphery of the hole at a portion on the opposite side from the gate. A thin-walled bridging portion for resin flow connecting the gate side and the opposite side part is formed in at least the center part of the hole, and the resin flowing from the gate side reaches both sides of the opposite side part of the hole, A cross-integrated injection molded body characterized by a bridge part that joins from three sides.