JPH0353860Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a hollow plastic insert for a foamed molded product that is embedded in the molded product at the same time as the molding of the foamed product. The present invention relates to hollow plastic inserts formed of.

(Prior Art) The above-mentioned hollow plastic inserts having a partially formed opening are used in various foam molded products such as vehicle headrests and armrests.

FIG. 6 is a perspective view of an example 10 of a conventional hollow plastic insert with an opening formed therein.
This insert 10 is used as an insert for a headrest, and has an opening 1 formed as an insertion hole for a stay 12 for attaching the headrest.
It has 4. This insert 10 is attached to the stay 12
The vertical position of the headrest can be adjusted by moving the insert 10 up and down relative to the headrest. Therefore, the opening 14 for inserting the stay is made larger than the outer diameter of the stay 12 so as not to impede smooth vertical movement of the insert 10. And this insert 10 is the seventh
As shown in the partially cutaway perspective view of the headrest 16 shown in the figure, it is embedded within the foam 18 of the headrest and also has the effect of reinforcing the headrest 16. 2
0 is the epidermis.

By the way, in order to manufacture foam molded products with embedded inserts, from the viewpoint of workability and product appearance, the insert is placed in a mold, the foamed resin raw material is injected into the mold, foamed, and the area around the insert is In most cases, this is done by a method of forming a foam, a so-called integral foam molding method.

However, if the hollow plastic insert with the openings formed therein is used as is for integral foam molding, when the foamed resin raw material is foamed in the mold, the foamed resin raw material will enter the insert through the openings and foam inside the insert as well. That will happen. If foamed resin raw material enters the insert,
If the foam formed around the insert is smaller than the standard size, or if there is an internal vertical adjustment mechanism such as the insert 10 that moves up and down, that mechanism may not operate properly. Problems such as loss of information may occur.

Therefore, when manufacturing a foamed molded product using a hollow plastic insert in which an opening is conventionally formed, the stay insertion opening 14 of the insert 10 is The stay insertion opening 14 is sealed by disposing a packing 24 on the outer surface of the insert 10 and sandwiching the packing 24 between the outer surface of the insert 10 and the cavity surface 26 of the mold. The mold 22 has a dividing plane parallel to the plane of the paper, and FIG. 8 shows a cross section taken parallel to the dividing plane. Furthermore, for ease of understanding, the vertical adjustment mechanism is not shown.

(Problems to be solved by this invention) However, when the insert 10 is installed in the mold 22, the packing 24 tends to shift from its normal position or easily fall off from the insert, making it difficult to maintain a good quality. There was a problem where it was difficult to get the sticker. Further, there were also problems in that it took time to set up the gasket 24 and that the cost of parts for the gasket 24 increased unnecessarily.

This invention solves the above-mentioned problems of conventional hollow plastic inserts, namely, the difficulty of sealing the opening well, the time-consuming sealing process, and the high cost of parts for the seal. This is what I am trying to do.

(Means for solving the problem) This invention is a hollow plastic insert for a foamed molded product that is installed in a mold for a foamed molded product and embedded in the molded product at the same time as the foamed molded product is formed. The end of the opening formed in a part of the insert is made into a thin cylindrical shape and serves as a sealing part, and when the insert is installed in a mold, the sealing part is crimped onto the mold cavity surface. It is characterized by:

(Function) When molding a foamed product, this insert is placed at a predetermined position within the mold. At this time, a thin cylindrical seal formed at the end of the opening of the insert is crimped onto the mold cavity surface, and the crimping seals the end of the opening. Then, in this state, a foamed resin raw material is injected into the mold, and a foamed molded product is formed. Since the end of the opening is thus sealed by the thin seal portion, the foamed resin raw material injected into the mold foams to form a foam around the insert without entering into the insert. As a result, the resulting foamed molded product has the risk of the foam surrounding the insert becoming smaller than the standard size, or the adjustment mechanism inside the insert not working properly due to the foamed resin material entering the insert. It becomes something that does not exist.

In addition, sealing the insert opening can be done simply by placing the insert in a predetermined position within the mold without using any separate parts, which simplifies the process and ensures a reliable sealing effect at all times. Moreover, the product price is low.

(Example) This invention will be explained below using a headrest insert as an example. However, the present invention is not limited to headrests, and can be similarly applied to other articles such as armrests.

FIG. 1 is a perspective view of a headrest insert 30 and a stay 12 inserted into the insert 30 according to this invention.

This insert 30 consists of an upper part 31 and a bottom part 33 that are integrated by bolts or the like, and is hollow inside. Top 31 and bottom 33
is obtained by blow molding or injection molding a thermoplastic such as polypropylene or ABS resin, and the bottom part 33 has an opening 32 for inserting the stay 12 that projects outward in a cylindrical shape. There is. The inner diameter of the opening 32 is larger than the outer diameter of the stay 12 so that the insert 30 can move up and down with respect to the stay 12. A thin cylindrical seal portion 34 is formed at the end of the opening 32. The shape of the seal portion 34 is a lattice shape with an enlarged tip as shown in FIG.
Alternatively, the shape shown in FIGS. 2a to 2d or other shapes may be used. The seal portion 34a shown in FIG. 2a is the same as the seal portion 34 shown in FIG. The seal portion 34c shown in FIG. 2c has vertical folds 37.
The seal portion 34d shown in FIG. 2d
is bellows-shaped. Furthermore, the seal portion 34
A protruding piece similar to the protruding piece 35 in FIG. 2a may be provided on the outer peripheral surface of b. Note that the shape of the seal portion is optimized depending on the shape of the opening, the thickness of the seal portion, and the like.

On the other hand, a rib (FIG. 3 30a) is formed on the inner surface of the bottom portion 33 of the insert 30 to restrict the range of vertical movement of the insert 30.

Further, an insert vertical adjustment mechanism is provided inside the insert 30. The vertical adjustment mechanism is as follows:
No. 15489, the stay 1 is engaged with a notch formed in a part of the stay 12 in stages.
A simple mechanism is one consisting of a spring-like clip that fixes the vertical movement of the insert 30 relative to the insert 2. Note that the vertical adjustment mechanism is not the gist of the present invention, and will therefore be omitted in this description.

The stay 12 is made of a solid or hollow metal rod, and in addition to the U-shaped one shown in this example shown in Fig. 3, the stay 12 can be made of two separate pieces, or one with one leg. be. Also, stay 1
2 is formed with a positioning recess 13 for positioning the insert 30 at a proper position in the mold during headrest manufacturing.

The insert 30 thus formed is placed in the mold 22 as shown in FIG. 3 during the manufacture of the headrest. FIG. 3 is a sectional view of the mold 22 taken at the same position as FIG. 8.

A cavity 23 having the same shape as the outer shape of the head rest is formed in the mold 22.
An insert is installed in the cavity 23 at a predetermined position. The insert device includes an insert 30 and a stay 1 inserted into the insert.
After placing the stay 12 in the cavity 23, a part of the stay 12 is inserted into the rib 3 in the insert 30.
Pull it out of the mold 22 until it hits 0a,
This is done by engaging the positioning recess 13 with the stopper 25 of the mold. Thereby, the insert 30 is fixed at a predetermined position within the cavity 23, and at the same time, the seal portion 34 at the opening end is pressed against the cavity surface 23a, and the end of the opening 32 is sealed. Note that the cavity surface to which the seal portion 34 is crimped is the mold 2 shown in FIGS. 4 and 5.
It is also a preferable embodiment to form uneven shapes 23a and 23b in accordance with the shapes of the seal portions 34 and 34b, as shown in 2a and 22b, to improve sealing performance.

Then, a foamed resin raw material such as a urethane foam raw material is injected into the cavity 23 and foamed in a closed mold state. At this time, since the end of the opening 32 of the insert is sealed by pressure bonding between the sealing part 34 and the cavity surface 23a, the foamed resin raw material foams without entering the insert 30 and forms a foam around the insert 30. Form.

After foaming is completed, the molded product is removed from the mold and covered with a skin material to obtain a headrest.

Note that if a skin material is provided in the cavity 23 and the foamed resin raw material is injected and foamed, a molded article covered with the skin material, that is, a headrest, can be manufactured at the same time as the foam is molded.

(Effects of the invention) This invention uses a thin-walled cylindrical seal at the end of the opening of a hollow plastic insert for foam molded products, and when this insert is installed in a mold for molding a foam molded product. , since the seal part is crimped onto the mold cavity surface,
We were able to achieve the following effects.

That is, when molding a foamed product, by simply placing this insert in a predetermined position in the mold, the sealing part can be pressed against the cavity surface and the opening end can be reliably sealed, thereby preventing the foam from forming. This made it possible to prevent the resin raw material from entering the insert. Therefore, it was possible to eliminate the need for separate parts such as packing, and it was possible to simplify the work during foam molding. Moreover, it is possible to eliminate sealing defects at openings that conventionally occur due to poor packing, and it has become possible to always obtain good foam molded products.
Furthermore, since packing was no longer necessary, the cost of foam molded products could be reduced. Further, since the seal portion is molded at the same time as blow molding or injection molding of the insert, molding of the insert does not become complicated or difficult.

[Brief explanation of the drawing]

Figures 1 to 5 relate to embodiments of this invention; Figure 1 is a perspective view of the headrest insert with the stay inserted; Figures a to d in Figure 2 show embodiments of the seal portion; FIG. 3 is a perspective view, FIG. 3 is a sectional view of the mold showing a state in which an insert is installed in the mold, and FIGS. 4 and 5 are sectional views of essential parts of each embodiment of the mold. Also, Figures 6 to 8
The figures relate to a conventional insert for a headrest, and FIG. 6 is a perspective view of the insert, FIG. 7 is a partially cutaway perspective view of the headrest, and FIG. 8 is a view of the mold showing the state in which the insert is installed in the mold. FIG. 32...Opening part, 34...Seal part.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A hollow plastic insert for a foamed molded product that is installed in a mold for a foamed molded product and embedded in the molded product at the same time as the molded product is formed; The end of the opening formed in the part is formed into a thin-walled cylindrical shape and serves as a sealing part, and when the insert is installed in a mold, the sealing part is crimped onto the mold cavity surface. Hollow plastic inserts for foam molded products. (2) A hollow plastic insert for a foam molded product according to claim 1 of the utility model registration claim, in which the cylindrical seal portion has a tupular shape with an enlarged tip. (3) The cylindrical seal part has a concave shape,
A hollow plastic insert for a foamed molded product according to claim 1 of the utility model registration claim. (4) A hollow plastic insert for a foamed molded product according to claim 1, in which the cylindrical seal portion has a bellows shape. (5) A hollow plastic insert for a foam molded product according to claim 2 of the utility model registration claim, which has a protruding piece on the inner peripheral surface of the cylindrical seal part. (6) A hollow plastic insert for a foamed molded product according to claim 2 of the utility model registration claim, wherein vertical pleats are formed in the cylindrical seal portion. (7) A hollow plastic insert for a foamed molded product according to claim 3 of the utility model registration, wherein a protruding piece is provided on the outer peripheral surface of the cylindrical seal part.