JPH0571011B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for molding a frame-integrated foam pad, and more particularly to a method for preventing non-uniform foaming due to uneven distribution of resin during resin injection.

[Prior Art] Recently, a method has been adopted in which a frame is integrated at the same time as the foam pad is molded, thereby saving the labor of assembly work after molding.

By the way, as a method for molding a foam pad in a mold, there is a method in which a foaming resin stock solution is poured into the mold in an open state, the mold is then closed, and the pad is foamed inside.
A resin injection head is installed in the center of the upper mold in advance,
There is a method of injecting into the mold through this injection head while the mold is closed, and causing internal foaming.

According to the former method, the steps from injection to mold clamping are time-consuming, and especially when the frame is temporarily fixed to the upper mold, the weight is increased, so the mold clamping operation takes time.

Therefore, when this type of heavy upper mold is used, the latter injection method using a resin injection head is a practical molding method.

[Problems to be Solved by the Invention] However, according to this method, since there is only one injection point, the injected resin concentrates in one place in the mold, and foaming starts from there, causing air to flow into the molded product. Foaming defects such as pooling and lack of thickness at the farthest point from the injection position on the periphery were likely to occur.

As a countermeasure to this problem, it has been considered to receive the resin injection head at multiple locations, but in this case, the configuration would be complicated, and furthermore, it would be necessary to mix the foamable resin stock solution and then branch it and supply it to the injection head. This was difficult due to factors such as viscosity.

This invention solves the above-mentioned problems, and in particular, provides a method for molding a frame-integrated foam pad in which a frame is used to diffuse injected resin inside the pad. The purpose is to provide

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a lower mold and an upper mold, a frame is temporarily fixed to the upper mold, and the upper mold is engaged with the lower mold. In a method for molding a frame-integrated foam pad in which a foamed synthetic resin stock solution is injected through a resin injection head provided in an upper mold and the foam is foam-molded integrally with the frame, the surface of the frame facing the resin injection head A diffusion plate was previously provided in the mold, and the resin stock solution injected into the mold through the injection head hit the diffusion plate and was dispersed and injected into various parts of the mold from the periphery of the diffusion plate.

[Operation] Since the resin stock solution injected into the mold is supplied to each part of the mold through the diffusion plate, the foaming state can be made uniform. Further, since the diffusion plate is embedded inside the foamed resin, it is possible to strengthen the integral bond with the foamed resin.

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

1 to 3 show a foam molding method in which the present invention is applied to a skin material and a frame integral foam molding method.

In the figure, 1 is a lower mold having a mold surface corresponding to the surface shape of the seat cushion, and 2 is an upper mold that engages with the lower mold 1.

A skin material 3 is installed in advance on the mold surface of the lower mold 1.

Further, a resin injection head 4 is provided in the center of the upper mold 2, from which a foamable resin stock solution is injected into the mold.

Furthermore, a cushion frame 5 is placed on the mold surface of the upper mold 2.
is temporarily fixed.

As shown in FIG. 2, this cushion frame 5 has a plurality of S springs 5b suspended inside a frame main body 5a formed in a frame shape.

Further, the resin injection head 4 of this frame 5
A diffusion plate 6 is arranged at a position facing the injection surface. The diffusion plate 6 has a predetermined diffusion area that is integrated with the inside of the frame body 5a by welding or the like, and a small through hole 6a is formed in a part of the diffusion plate 6.

In the above configuration, the upper and lower molds 1 and 2 are engaged with the peripheral edge of the skin material 3 being clamped and fixed between the flanges formed on the peripheral edges of the lower mold 1 and the upper mold, and the foamable resin stock is poured into the resin injection head 4. When the liquid is injected into the mold, the stock solution discharged from the injection head 4 falls onto the diffusion plate 6 as shown in FIG. , and others are dropped in a dispersed state from the periphery of the diffusion plate 6.

Therefore, the resin stock solution is dispersed and injected into each part of the mold, and foaming starts in this state. On the front side, the foaming hardening is completed in a state where it is integrated with the skin material 3, and on the back side, the cushion The molding is completed with the frame 5 integrated in a buried or semi-buried state.

Here, the diffusion plate 6 is completely embedded inside the foam pad, and serves to strengthen the integral connection between the foam pad and the frame 5.

In addition, when the skin material 3 is a one-piece type as in the example, in the conventional method, the foamable resin stock solution injected into the mold concentrates in one place of the skin material 3, and impregnation is particularly easy to proceed in the concentrated area. A problem has occurred. This problem is fully solved by the present invention, and it is possible to sufficiently prevent the degree of impregnation from increasing locally.

[Effects of the Invention] As described above in detail using the embodiments, the method for molding a frame-integrated foam pad according to the present invention has the following effects.

That is, since the resin stock solution injected into the mold is supplied to each part of the mold through the diffusion plate, the foaming state can be made uniform even when the resin stock solution is injected from one resin injection head.

Furthermore, since the diffusion plate is embedded within the foamed resin upon completion of foam molding, it is possible to strengthen the integral bond between the foamed resin and the frame.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the entire foam molding mold to which the method of the present invention is applied, Fig. 2 is a plan view of a cushion frame applied to the same molding method, and Fig. 3 is a view during injection of the foamable resin stock solution. FIG. 3 is a partially enlarged sectional view. 1...Lower mold, 2...Upper mold, 4...Resin injection head, 5...Cushion frame, 6...Diffusion plate.

Claims (1)

[Claims] 1 A lower mold and an upper mold are provided, a frame is temporarily fixed to the upper mold, and the foamed synthetic resin stock solution is injected through the resin injection head provided on the upper mold with the upper mold engaged on the lower mold to form a foam. In the method of molding a frame-integrated foam pad, in which a diffusion plate is provided in advance on the surface of the frame facing the resin injection head, and the resin stock solution injected into the interior through the injection head is A method for molding a frame-integrated foam pad, characterized in that the foam pad hits the diffuser plate and is dispersed and injected from the periphery of the diffuser plate into various parts of the mold.