JPH03213308A - Manufacturing device for curved plywood - Google Patents

Abstract

PURPOSE:To manufacture a plurality of curved plywoods of same curvature radius simultaneously by placing spacers with their recessed surfaces having the curvature radius same as that of a press mold and their recessed surfaces having the curvature radius larger than that of the press mold by the plate thickness of one plywood between one plywood and another plywood and clamping the same with the press molds while heating and forming. CONSTITUTION:A plurality of thin plates coated with a bonding agent are overlapped to form a flat plywood 4a. Spacers 3 are placed respectively between a plurality of said plywoods 4a and clamped by press molds 1 and 2, curved and deformed, and steam is applied through heating tubes 7 of the spacers to heat the plywoods 4a. All the plywoods are in contact with the spacers and heated uniformly. When the bonding agent is hardened by heating, the plywood is released and forms a curved playwood. As only the projected surface of the spacer 3 is provided with the same curvature radius R as that of the press mold and the recessed surface is provided with the curvature radius larger by the plate thickness (t) of one plywood, all the manufactured plywoods are of same curvature.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an apparatus for manufacturing curved plywood used for concrete formwork and the like.

(Prior Art) Fig. 6 shows a conventional apparatus for manufacturing curved plywood, in which reference numeral 1 is a press die, and numeral 2 is a press die.
is a press mold. The plywood 4a, which has just been coated with adhesive and laminated with thin sheets, is sandwiched between press molds 1 and 2 and deformed into a curve (FIG. 7). The plywood 4a is heated in this state, and when the adhesive is cured, it is released from the mold to obtain a curved plywood. For heating, a hot air heater or a high frequency heating device is used.

The problem with such conventional equipment is that it can only produce one plywood sheet at a time. This is because if a plurality of plywood sheets were stacked and molded at once, as shown by the chain lines in FIG. 6, the radius of curvature of the lower plywood sheet would become larger.

(Problems to be Solved by the Invention) In view of the above-mentioned problems of the conventional apparatus, an object of the present invention is to obtain an apparatus that can simultaneously manufacture a plurality of curved plywood sheets having the same curvature.

(Means for Solving the Problems) The curved plywood manufacturing apparatus of the present invention includes a press mold having a curved convex surface, a press receiving mold corresponding thereto, and a plurality of sheets of plywood sandwiched between these press molds. The spacer has a convex surface having the same radius of curvature as the press mold, and a concave surface having a radius of curvature larger than that by the thickness of one plywood sheet. have.

As the heating means, a steam heating tube can be inserted inside the spacer.

(Operation) Apply adhesive and stack several thin sheets to make a flat plywood board. Before the adhesive hardens, place a spacer between them and firmly sandwich them with a press mold. In this way, each plywood is deformed into a curve according to the press mold. After doing this, heat the plywood. Wait for the adhesive to harden and release the mold to create curved plywood.

The convex surface of the spacer has the same radius of curvature as the press mold, and the concave surface has a radius of curvature larger than that by the thickness of one plywood sheet, so that all the plywood molded in this way has the same radius of curvature. .

(Embodiment) In FIG. 1, reference numeral 1 indicates a press die having a curved convex surface with a radius of curvature R, and reference numeral 2 indicates a press receiving die corresponding thereto. The receiving mold 2 is simply a flat steel plate, and elastically deforms depending on the shape of the object pressed against it.

Reference numeral 3 indicates a curved plate-shaped spacer. As shown in detail in FIG. 4, the spacer 3 has a steam heating pipe 7 placed between two steel plates 5.6. A liner 8 having different thicknesses is placed between the steel plate 6 and the heating tube 7. The thickness of the liner 8 gradually decreases from the center to the left and right. By doing this, the radius of curvature of the convex surface of the spacer 3 is the same R as that of the press die 1, and the radius of curvature of the concave surface is larger than that by the thickness t of one plywood sheet.

The steam heating pipes 7 are connected in series, as shown in FIG.

To manufacture curved plywood, first, apply adhesive and overlap several thin sheets 9 to obtain flat plywood 4a.0 plywood 4
The plate thickness t of a is, for example, between 12 and 12.

Immediately (before the adhesive hardens) this plywood 4a,
A plurality of pieces (three pieces in the figure) are strongly sandwiched with a spacer 3 between them using a press mold 1.2, and the pieces are bent and deformed (Fig. 2).

In this way, steam is passed through the heating tube 7 of the spacer to heat the plywood 4a. All the plywood is in contact with the spacer, so it heats up evenly. Heating temperature is 100-130
It is ℃.

The adhesive is cured by heating for several tens of minutes, and the mold is released to obtain a curved plywood 4b as shown in FIG. In the spacer 3, the convex surface has the same radius of curvature R as the press die, and the concave surface has a radius of curvature larger than that by the thickness t of one plywood sheet, so that all the finished plywood sheets 4b have the same curvature. Become.

(Effect of the invention) According to this invention, a spacer whose convex surface has the same radius of curvature as the press die and whose concave surface has a radius of curvature larger than that by the thickness of one plywood sheet is placed between the plywood sheets. By placing the pieces on the board and sandwiching them between the press molds, it is possible to simultaneously form many pieces of curved plywood with the same curvature.

By heating the plywood by passing a steam pipe through the spacer, multiple sheets of plywood can be heated evenly.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a curved plywood manufacturing device, Fig. 2 is an explanatory diagram of the same equipment when pressed, Fig. 3 is an explanatory diagram of curved plywood,
Figure 4 is a partial sectional view of the spacer, Figure 5 is a partially cutaway plan view of the spacer, Figure 6 is an explanatory diagram of a conventional curved plywood manufacturing apparatus, and Figure 7 is an explanatory diagram of the same apparatus during pressing. It is.

Claims (1)

[Claims] 1. Between a press mold (1) having a curved convex surface, a corresponding press mold (2), and a plurality of plywood sheets (4a) sandwiched between these press molds. The spacer consists of a curved plate-shaped spacer (3) placed on the plywood and a means for heating the plywood. A manufacturing device for curved plywood having a radius of curvature (R+t) as large as the board thickness. 2. The apparatus for manufacturing curved plywood according to claim 1, wherein said heating means comprises a steam heating tube (7) incorporated inside said spacer.