JPS6013522A - Vacuum formed piece and vacuum forming mold thereof - Google Patents

Abstract

PURPOSE:To form a door-back keeping strength as a shelf and having an increased storing space by a method wherein a vacuum forming mold is provided with a retaining part capable of bridging a reinforcing part and a sheet between the reinforcing pieces is stuck closely to each other from projection. CONSTITUTION:Synthetic resin sheet 13 is fixed at four corners, heated by a heater and platisized. Then, chamber 30 is lifted to be stuck closely to a clamping frame and the opening part of the chamber 30 is blocked by the sheet 13. The pressure in the chamber 30 is increased by the discharge of the air to blow the sheet 13. Forming mold 17 retaining reinforcing parts 16 is elevated and the plastisized and blown sheet 13 covers the vacuum forming mold 17. Since lower hollow portion 34 of the vacuum forming mold 17 is made vacuous, the sheet 13 is stuck closely to the forming mold 17, the sheet surfaces 14a, 14b located at the space from the surface of the forming mold 17 to the reinforcing part 16 are stuck to each other to produce a sticking shelf. Then, when the sheet 13 is cooled the mold 17 is lowered, and separated from the sheet 13, the door-back is formed as the reinforcing parts 16 are buried in the sheet 13.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to vacuum-formed products made by vacuum-forming thermoplastic synthetic resin, such as door bags used in refrigerators, freezers, etc., and molds for vacuum-forming the same. .

Structure of a conventional example and its problems A conventional vacuum forming mold and a refrigerator door bag (molded product) obtained using this mold will be explained with reference to FIGS. 1 and 2. In the figure, reference numeral 1 denotes a door bag having a protruding hole 3 and a shelf 4.4 on opposing surfaces and a lower surface. As a method of molding this door back 1, the protrusion 2. 2. A vacuum forming mold 7 has a U-shaped rising portion 6a forming a 3, a rising portion 6b forming a shelf 4, 4, and an appropriate number of vacuum holes 6 at predetermined positions. By covering with a synthetic resin sheet 8 such as heated and plasticized polypropylene, and drawing air through the vacuum hole 6,
The sheet 8 is vacuum formed into a predetermined shape. Therefore, the external shape of the molding die 7 directly becomes the shape of the molded product, that is, the shape of the door back 1.

When vacuum forming the door bag 1 having such a configuration, the thickness of the rising portion 6b of the molding die 7 is determined in order to maintain the strength of the door bag 1 as the shelf 4.
In order to release the sheet 8 that is in close contact with the mold, it is necessary to have an appropriate draft angle, and if the shelf has an undercut part, it is necessary to have a built-in undercut mechanism. It was something. If the thickness of the rising portion 6b is large as described above, the wall thickness of the shelf 4 increases, and the storage space of the door bag 1 is significantly reduced. Furthermore, since the thickness of the sheet 8 that forms the shelf section 4 is heated, stretched, and thinned, its strength as a shelf is weak, and there is a problem that stored items are likely to hit it and break due to repeated opening and closing of the trench door. .

OBJECTS OF THE INVENTION The present invention provides a vacuum-formed product capable of forming a thin-walled shelf portion that can increase the storage space for door banks and the like while maintaining the strength of the shelf, and a mold for forming the product. With the goal.

Structure of the Invention In order to achieve this object, the present invention provides a sheet part having a reinforcing part when forming a shelf part, and the vacuum forming mold of the shelf part has an upright part located on the shelf part. Providing a holding part that can bridge the reinforcing part without providing a part,
A continuous raised part and a vacuum hole are provided at the top of the continuous raised part at a position facing the reinforcing part, and the sheets between the reinforced parts are brought into close contact with each other from this raised part to form a strong thin shelf part.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 to 12. First, a door bag as a vacuum-formed product of the present invention will be explained with reference to FIGS. 3 and 4. The door back 1o has protrusions 11, 11.12 formed on both opposing side and lower surfaces as in the conventional case, and further includes both protrusions 11.12.
11, the sheet surface 14a and the sheet surface 14b of the synthetic resin sheet 13 forming the door back 10 are thin.
A close-contact shelf 16 is formed in which the two are in close contact with each other, and a holding portion 15' is formed inside the frontmost end of the close-contact shelf 15, on which a reinforcing component 16 such as an iron rod or wire is held. That is, reinforcement part 1
6 is interposed so as to be surrounded by both sheet surfaces 15a and 15b.

Next, about the vacuum forming mold for the door bag 1o, Part 6
This will be explained along with FIGS. The molding die 17 forms the protruding parts 11, 11.12 of the door back 1Q, with rising parts 18° 19 on opposite sides and rising parts 2o on the lower surface.
and has. The above-mentioned reinforcing part 16 is attached to the holding part 21.1 at a predetermined height of the opposing rising part 18.19 of the molding die 17.
22 bridges the top grooves 23, 24 formed between them.

Further, a continuous tapered raised part 25 is formed on the surface of the molding die 17 facing the reinforcing part 16 and on the surface of the holding part 21.22, and a predetermined number of vacuum holes are formed in the top part 26 of the raised part 25. There is a 2nd period.

Next, the vacuum forming method for the door bag 1Q using the molding die 1 will be explained step by step with reference to FIGS. 8 to 12. A synthetic resin sheet 13 made of polypropylene or the like is fixed on four sides by clamps 28, and is heated and plasticized by upper and lower heaters 29 (FIG. 8).

Next, after moving the heater 29, the chamber 30 located below the clamp 28 rises, and the clamp 28
The opening 32 of the chamber 30 is closed by the sheet 13. Furthermore, air is discharged from the discharge port 33, the pressure inside the chamber 30 increases, and the sheet 13 that has been plasticized by heating is blown. (Figure 9)
Then, the molding die 17 holding the reinforcing component 16 in the chamber 30 rises, and the plasticized and blown sheet 13 is placed over the vacuum molding die 17. (
(Fig. 10) Next, by evacuating the lower cavity 34 under the vacuum forming mold 1, the pressure in the space 36 formed by the forming mold 17 and the sheet 13 is reduced through the vacuum hole 27, and the sheet 13 is It is brought into close contact with the molding die 17 and vacuum-formed into a predetermined shape. However, at this time, the heated and plasticized sheet 13
is prevented from deforming by the reinforcing part 16 held at a predetermined height on the rising parts 18 and 19, so it is stretched from both sides so as to wrap around the reinforcing part 16, and a continuous raised part is formed at a position facing the reinforcing part 16. The vacuum hole 27 provided at the apex 26 of the reinforcing component 16 reliably reduces the pressure between the sheet surfaces 16a and 15b on both sides surrounding the reinforcing component 16, and the holding portion 15'
is formed.

Furthermore, a sheet surface 14a located in a space extending from the molding die 1γ surface where the vacuum hole 27 is located to the reinforcing component 16
, 14b come into close contact with each other, and since the raised portion 25 acts as a guide for the place where they come into close contact, a contact plate 16 is formed at a fixed position. (
(Fig. 11) After that, the sheet 13 is cooled, and the molding die 1
7 is lowered and the molding die 17 and sheet 13 are released, the reinforcing component 16 is embedded in the sheet 13 and integrated, thereby forming the desired door pack 10. (Fig. 12) The door pack 10 formed in this manner is reinforced by integrating the reinforcing parts 16, and the wall thickness of the adhesion plate 15 is only as thick as two stretched sheets 13. The plate thickness at the contact area becomes thicker due to the close contact between the two sheets. Therefore, unlike the conventional example, the wall thickness of the shelf does not become thick and the storage space does not decrease, the strength of the adhesive layer 15 is maintained by the reinforcing component 18, and the adhesive plate 15 formed by the adhesive layer has a thickness is doubled, significantly improving durability against contact with stored items. The molding die 17 for producing such a door pack 10 has a continuous raised part 26 at a position facing the reinforcing part 16 and an apex 26 of the raised part 26.
By providing a vacuum hole 27 in the sheet 13,
The position where the members come into close contact with each other is determined, and the positioning of the contact plate 16 is easily and reliably formed.

Effects of the Invention As is clear from the above explanation, when the vacuum-formed product of the present invention is used as a door bank, the adhesion part serves as a shelf to significantly improve the storage space, and the strength of the reinforcing parts and the adhesion part is also great. . Furthermore, the vacuum forming mold includes a holding part that bridges the reinforcing part, a continuous raised part at a position opposite to the reinforcing part, and a predetermined number of vacuum holes at the top of the raised part, and the bottom of the mold. The sheet can be closely molded in the space formed by the reinforcing parts, and the relationship between the reinforcing parts, the raised portions, and the vacuum holes allows for a complete adhesion sheet layer to be obtained, and the molding die itself can be simplified.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view of a conventional door pack, Fig. 2 is a vertical cross-sectional view of a conventional vacuum forming mold and door knob, and Fig. 3 is a vacuum formed product according to an embodiment of the present invention. 4 is a longitudinal cross-sectional view of the door bank, FIG. 5 is a cross-sectional view of a vacuum forming mold according to an embodiment of the present invention, and FIG. 6 is a cross-sectional view of the same molding die. Enlarged perspective view of reinforcing part holding part, 10th door bank (vacuum formed product),
13... Synthetic resin sheet, 16... Adhering plate (adhering part), 16'... Holding part, 16...
... Reinforcement parts, 17 ... Vacuum forming mold, 1
8, 19... Rising portion, 26... Raised portion, 27... Vacuuming hole. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure/ Figure 3 1θ Figure 4 Figure 5 Figure 6 Figure 7 Figure 7 Figure 10

Claims (2)

[Claims] (1) It is constructed by vacuum forming a thermoplastic synthetic resin sheet, and includes opposing protrusions, a holding part that holds the reinforcing component at a predetermined height position between the two protrusions, and a holding part that holds the reinforcing component from the bottom of the sheet. A vacuum-formed product consisting of a close contact part formed by closely contacting sheet parts facing each other in the space leading to the part. (2) An opposing rising part forming a protrusion on the thermoplastic synthetic resin sheet, a holding part formed on the opposite surface of the rising part and bridging the reinforcing component at a predetermined height position, and a holding part formed between the rising parts. A mold for vacuum forming, comprising a raised part formed opposite to the reinforcing part, and a predetermined number of vacuum holes for sucking the synthetic resin sheet at the top of the raised part.