JPS6226294B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an integrally foamed sheet cushion body made of a spring and a foamable synthetic resin, such as urethane. Provided is a method for producing an integrally foamed seat cushion body, which allows the production of a seat cushion body that exhibits various damping properties as required, by a relatively simple method. There is something to do.

This type of integrally foamed sheet cushion body is made by embedding an S spring with a fixed mouth or a spring-and-frame assembly fitted with a formed wire while foaming a synthetic resin such as urethane. In order for the spring body to exhibit the desired damping performance with the optimum amount of urethane, it is necessary to effectively place urethane in the mouth of the spring.

That is, the seat cushion body shown in FIG. 1 has a structure in which the crown portion 1b of the spring of the spring and frame assembly 1 is embedded in the urethane 2, and the fish mouth portion 1a of the spring is exposed. With this configuration, the amount of urethane used can be saved, but since the spring mouth portion 1a is not embedded in the urethane, the spring exerts a normal spring effect and does not exhibit the desired damping performance at all, resulting in a fluffy sheet. . Also the second
The seat cushion body shown in the figure has a structure in which a spring and frame assembly 1 is entirely embedded in urethane 2. With this configuration, the damping performance of the cushion body can be fully demonstrated, but on the other hand, the crown part 1 of the spring does not have much influence on this damping performance.
As a result, more urethane 2 than necessary is placed in the lower part of b, which increases the amount of urethane used, resulting in a seat cushion that has no merits in terms of both weight and cost.

Therefore, the upper mold of the foaming mold is constructed with a protruding upper mold, and the upper mold is used to form a recess with a rectangular cross section or an undercut portion 4a as shown in FIGS. 3 and 4 at the lower part of the crown portion 1b of the spring. The manufacturing method for forming parts 3 and 4 was adopted, but the third
The cushion body shown in the figure still has insufficient savings in the amount of urethane used, and the cushion body shown in Figure 4 has an undercut portion 4a that can only be provided on either the front or the rear due to the nature of the mold. The depth of the portion 4a cannot be made very deep, and these manufacturing methods have various drawbacks.

The present invention has been made in view of the above-mentioned circumstances, and is a novel method for obtaining a sheet cushion body that exhibits the desired damping performance with an optimum amount of synthetic resin by an extremely simple method of using a mold and an independent core. It is an object of the present invention to provide a method for manufacturing an integrally foamed sheet cushion body.

The present invention will be described in detail below based on illustrated embodiments. Note that parts common to the conventional example will be explained using common symbols.

As shown in FIG. 5, a spring-and-frame assembly 1 using an S spring or formed wire having a fish mouth 1a is set in a predetermined position on a lower die 5 that forms the outline of the seat cushion body, and the assembly is shaped into an appropriate shape. The cores 6 and 7 formed in the above shape are removably locked to the fish mouth 1a so as to be housed in the fish mouths 1a and 1a formed at the front or rear of the spring while maintaining an appropriate distance from the spring. After pouring the urethane foaming stock solution into the lower mold 5, the upper mold 8 having a substantially square cross-sectional shape with a concave portion 8a is placed over the opening of the lower mold 5, and then foaming is carried out in accordance with a conventional method. When the upper mold 8 is placed over the opening of the lower mold 5, the mold wall surface 8b of the recessed part 8a is in close contact with one side of 6 and 7, and the bottom part 8c of the recessed part 8a is in contact with the crown part 1b of the spring. They are formed so as to maintain the minimum required distance. When the synthetic resin is foamed, the upper mold 8 and the cores 6 and 7 act as if they were an integral mold.

After foaming, the upper mold 8 is released, and the core 6,
7 is removed from the fish mouth 1a and the lower mold 5 is released, thereby molding the seat cushion body 9 having the cross-sectional shape shown in FIG. This seat cushion body 9 has a concave portion 10 having undercut portions 10a and 10b of sufficient depth formed on the back side thereof, so that the amount of synthetic resin can be sufficiently saved, and the spring and frame assembly 1 can be sprung. Since the entire structure is embedded in the synthetic resin 2, it can exhibit an excellent damping effect.

Although two cores 6 and 7 are used in the above-described embodiment, it is of course possible to manufacture the seat cushion body using only one of them, if necessary.

As detailed above, according to the present invention, despite the extremely simple method of using a core independent of the formwork, it is possible to sufficiently save the amount of synthetic resin used and to achieve an excellent damping effect. By appropriately changing the design of the core shape, it is possible to extremely easily manufacture a seat cushion body that exhibits a desired damping effect.

[Brief explanation of the drawing]

1 to 4 are sectional views of a conventional seat cushion body, FIG. 5 is a sectional view of the seat cushion body before release according to the present invention, and FIG. 6 is a sectional view of the seat cushion body after release from the mold according to the present invention. be. 1...Spring and frame attachment, 2...
... Foamable synthetic resin, 3, 4... Concave portion, 5... Lower die, 6, 7... Core, 8... Upper die, 9... Seat cushion body, 10... Concave portion.

Claims (1)

[Claims] 1. In integral foam molding of a sheet cushion body in which an S spring or formed wire having a fishing mouth is embedded in a foamable synthetic resin,
At least one core having an appropriate shape is placed in the fish mouth so that one side of the core is in close contact with the wall surface of the mold forming the back of the sheet cushion body and most of the core is contained within the fish mouth. A method for manufacturing an integrally foamed sheet cushion body, characterized in that the mold and the core are removably locked and act as if they were an integral mold when the synthetic resin is foamed.