JPH0230246B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a headrest and a method for manufacturing the same.

In order to ensure the safety of the driver's or passenger's neck, a headrest is attached to the upper part of the backrest of the seat, and a large transparent lens is installed in the center of the headrest to prevent the rear field of view from being narrowed due to the existence of this headrest. A head rest with a window has been proposed and has been well received. However, providing this see-through window complicates the manufacturing process of the headrest, and there is a risk that the headrest itself may be weakened.

The headrest according to the present invention has a reinforcing bridge attached across the center of a large see-through window in the center of the headrest main body, and a specific example thereof will be explained with reference to the drawings. Then, the headrest 1 is formed by bending a bar to form a rectangular core frame 2, and both end extensions of the core frame 2 extend downward to form a pair of stays 3, 3.
Further, a single crosspiece 4 is extended across the center of the rectangular core frame 2 to form a core body 5 of the headrest. And core frame 2 including crosspiece 4
and a part of the stay 3 are covered with an elastic foam 6 around the core material, the outer surface of the elastic foam is further covered with a skin layer 7, and the core frame 2 is embedded in the center. A pair of stays 3, 3 forming a part of the core body 5 are provided below the headrest main body 8 to form headrest mounting legs, and a crosspiece 4 is provided in the center of the headrest main body 8. Two large viewing windows 10, 10 are formed separated by a bridge 9 embedded in the center.

As shown in FIG. 1, this bridge 9 can be extended vertically to the window opening in the headrest body 8, and two see-through windows can be provided on the left and right sides of the bridge 9, or it can be extended horizontally. It is also possible to provide two viewing windows above and below the bridge 9. (Figure 2).

By arranging the bridge 9 to divide the window in the center of this large window, the headrest itself can be strengthened, and the original effect of the see-through headrest is also impaired. There's nothing wrong with that.

By arranging the bridge in the see-through window formed in the headrest main body as described above, it becomes extremely easy to manufacture an annular headrest with this kind of core inside, and it also produces excellent quality effects. This brought about disastrous results.

Next, we will move on to an explanation of the manufacturing method of the headrest in which the bridge part is attached to the central part of the see-through window.
First, for a conventional headrest with one large see-through window in the center, a hollow outer skin of an annular body with a core inside is manufactured by known blow molding, and then molded with metal. The hollow skin body was removed from the mold, and as shown in Fig. 3,
When the foaming stock solution injection hole 19 is located on the upper side and a foaming stock solution such as polyurethane foam is injected from the injection hole, the foaming stock solution flows in left and right directions as shown by the arrows in the figure, and flows into the annular skin body. The foaming concentrates merge in the lower central part B, and in this confluence zone, an air pocket is generated in which the gas containing residual air is pushed from the back by the concentrate and remains, and the resulting foam is obtained. There was a risk that the headrest would produce a defective product with localized weak parts that would reduce the product's value by half.

In this invention, a bridge section is provided in the center of the see-through window of the headrest main body, and the bridge section is actively used as a flow path for the foaming solution, thereby preventing the formation of the air pocket. A specific method for manufacturing the head rest will be explained using the drawings.

First, as shown in FIGS. 4 and 5, an annular hollow body containing a core 5 forming the skin layer 7 of the headrest 1 is made of chloride extruded from a die 11 of an extruder. The tip of the approximately semi-cylindrical parison 12 made of vinyl or ABS resin is held in a flat plate shape by holding a pair of rod-shaped members initially positioned directly below the die 11 with a gripping member 13 assembled with a predetermined gap. It is held in an extended state. Next, the gripping member 13 holding the parison in an expanded flat plate shape is moved on the same level plane as indicated by the arrow in FIGS. 4 and 5, and the parison 12 is continuously pushed out. It hangs down in a U-shape due to its own weight, and a large space 14 is formed between a pair of facing parison walls.

Note that instead of moving the gripping member 13 on the same plane, the gripping member 1 is positioned directly below the die of the extruder.
3 is moved in a U-shape according to the locus of the desired spread shape of the parison as the parison 12 is pushed out, thereby forming a space 1 between a pair of walls of the parison facing each other.
4 can also be formed.

Next, a wire rod, for example, a metal rod, is bent into a rectangular shape to form two parts of the core frame.
A core body 5 is formed by connecting a pair of stays 3, 3 to the core frame 2 with an extension part of the core frame.
is moved in the direction of the arrow in FIG. Half-split molds 15 and 15 are respectively located, and the core frame 2 and a portion of the pair of stays 3 fit into both inner surfaces of the half-split molds 15, and the metal forming the core frame 2 A semicircular circumferential groove 17 is carved with a semicircular groove sufficiently larger than the radius of the rod, and matches the shape of the core frame 2 and the stay 3.
A semi-annular guide groove 18 that serves as a nozzle port for injection of compressed air is connected to the holder.

The half-split molds are heated to approximately 40 to 60°C, and the pair of molds 15 and 15 form a parison 1 with the core body 5 sandwiched therein.
2 is sandwiched and closed from both sides, and the half-split mold is closed, so that the semi-annular circumferential groove 17 and the guide groove 18 are combined to form a substantially cylindrical groove, and from this guide groove part, for example, air can be A blow-out nozzle connected to the cylinder is inserted into the parison 12, and a blowout of 1 to 6 kg/cm ² is inserted into the parison 12.
Compressed air is injected to expand and bring the parison into close contact with the surface of the circumferential groove 17 of the mold.

After a cooling process, the half-split molds 15, 15 are opened to take out the annular hollow body in which the core body serving as the skin of the head rest is housed, and the burrs existing around the hollow body are removed.

The annular hollow body (outer skin of the headrest) in which the core is housed is inserted into a cylindrical parison having one slit extruded from a die of an extruder. After inserting the core frame part with the crosspiece in the center, molding work is done using a half-mold mold, or a pair of band-shaped parisons are extruded face-to-face from the die of an extruder, and the above-mentioned It is also possible to insert a core frame portion in which a crosspiece in the core body is arranged in the center, and perform molding work using a post-mold.

The skin body (annular hollow body) 7a of the headrest with the thus obtained core inside is fitted into a foam mold for shape retention, and the hollow bridge part 9a of the hollow skin body 7a is positioned vertically. The foaming of polyurethane resin, etc. is then carried out through the injection hole 19 (preferably combined with the pressurized air injection hole during the blow molding) which is opened in the upper part of the bridge part 9a and located in the lower surface of the headrest main body. The stock solution is first injected into the hollow bridge 9a, and the foaming stock solution is first poured into the hollow bridge 9a as shown by the arrow in the figure.
It flows down part a, and is split in both left and right directions at the lower end of the dividing part B, and while the stock solution pushes up the air in the hollow skin body 7a from behind, it does not merge at a certain point, but rises inside the hollow body and enters the body. When the foaming solution is uniformly dispersed in the hollow skin body and about 70 to 80% of the volume of the foaming solution is injected into the hollow skin body, the gas generated by the foaming reaction is pushed upward and discharged to the outside through the solution injection hole 19. At the same time, the remaining portion inside the skin body is filled with the foam layer 6 due to the reaction of the foaming stock solution. By locating the foaming stock solution injection hole 19 on the bottom of the headrest main body 8, more specifically between the pair of stays, even if the foam 6 overflows from the injection port 19, the appearance of the headrest main body will be greatly damaged. Never. Of course, when the hollow bridge portion 9a is arranged in the horizontal direction of the headrest main body as illustrated in FIG.

In this invention, the annular hollow skin body 7a
A hollow bridge part 9a is provided across the center of the large window part of the foaming solution, and the foaming stock solution is first injected and flowed down into this hollow bridge part 9a, so that the stock solution can always push up the remaining and generated gas toward the injection port 19 from behind. By forming a distribution channel, we were able to divide the flow so that the raw solution does not merge in one place, which prevents the formation of gas pockets in the skin, and also prevents the residual gas caused by the foaming reaction. Since the foam can be reliably removed, the interior of the hollow skin body can be uniformly filled with foam, and the resulting headrest also has a high level of safety.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view of a head rest embodying the present invention, Fig. 2 is a view corresponding to Fig. 1 showing another embodiment, and Fig. 3 is a flow of foaming stock solution during the conventional head rest manufacturing process. Explanatory diagram showing the situation, No. 4
The figure is an explanatory diagram at the initial stage of the manufacturing process once the present invention is carried out, Figure 5 is an explanatory diagram showing one manufacturing process of an annular hollow body with a core frame inside, and Figure 6 is an explanatory diagram according to the present invention. FIG. 2 is an explanatory diagram showing the flow of the foaming stock solution during the headrest manufacturing process. In the figure, 1 is a headrest, 2 is a core frame, 3, 3 is a stay, 4 is a crosspiece, 5 is a core body, 6 is an elastic foam, 7
is a skin layer, 7a is a hollow skin layer, 8 is a headrest main body, 9 is a bridge, 9a is a hollow bridge part,
10, 10 is a window, 11 is a die, 12 is a parison,
14 is a space, 15 and 15 are half-split molds, 17 is a semi-annular circumferential groove, 18 is a semi-annular guide groove, and 19 is an injection hole for the foaming stock solution.

Claims (1)

[Scope of Claims] 1. A rod-shaped core is embedded in the center of an annular elastic foam, the surface of the elastic foam is entirely covered with a skin layer to form a headrest body, and the rod-shaped core is embedded in the lower surface of the main body. A headrest is formed by extending a part of the headrest to form a leg part, and opening a see-through window in the headrest main body, and a bridge with a rod-shaped core arranged in the center arranged across the window. . 2 A core that is extruded into a belt shape from the die of an extruder and has a bar arranged in the center of a core frame formed by bending a bar into a rectangle between the walls of a parison that forms a pair of facing walls. A pair of half-split molds placed on both sides of the parison are closed to produce an annular hollow body containing the core frame, and a hollow bridge portion is formed in the center of the hollow body. A method for producing a headrest by injecting and flowing a foaming stock solution from above.