Vacuum molding device

Abstract

To restrain a wrinkle of a resin sheet.SOLUTION: An outer frame part 12 includes a first outer frame 21, a second outer frame 22, and a rotation center part 23 that becomes a rotation center of the first outer frame 21 and the second outer frame 22 when the first outer frame 21 and the second outer frame 22 are respectively driven and are in contact with a mold 11. The first outer frame 21 and the second outer frame 22 include holding parts 211, 221 that come into contact with a resin sheet 2 and projections 212, 222 that project to the side of a mold 11 at end parts 211b, 221a on the side of the rotation center part of the holding part 211, 221, a rotation center part 23 is arranged on the side of the mold 11 than respective holding parts 211, 221 of the first outer frame 21 and the second outer frame 22, respective projections 212, 222 disposed at the first outer frame 21 and the second outer frame 22 are arranged in contact with the rotation center part 23, and the outer frame part 12 bends in accordance with movement of the projections 212, 222 along the rotation center part 23.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to vacuum forming apparatus. [Background technology]

[0002] In recent years, vacuum forming has been performed in which a non-reinforced thermoplastic resin sheet is deformed together with a frame that restrains it, and then folded and molded. For example, as shown in Patent Document 1, molding is sometimes performed so that a molded product in which a sheet is laminated and integrated onto a surface has a shape that is largely bent in a two-dimensional direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-322501 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a process of folding a substantially flat resin sheet by closely contacting it with a convex mold, excess material may be generated in the resin sheet near the fulcrum of folding, resulting in wrinkles. In particular, if the resin sheet is a thick plate and excess material is generated at the fulcrum when the sheet is folded, wrinkles are likely to occur due to the weak tensile force near the fulcrum.

[0005] The present disclosure provides a vacuum forming apparatus that suppresses the occurrence of wrinkles near the folding points of a resin sheet when vacuum forming is performed. [Means for solving the problem]

[0006] The vacuum forming apparatus according to the present disclosure is a vacuum forming apparatus that bends and shapes a resin sheet by abutting an outer frame portion that restrains the resin sheet against a mold, the outer frame portion comprising a first outer frame, a second outer frame, and a rotation center portion that becomes the center of rotation of the first outer frame and the second outer frame when the first outer frame and the second outer frame are each driven to abut against the mold and the outer frame portion is bent, the first outer frame and the second outer frame have holding portions with which the resin sheet abuts, and protrusions that protrude toward the mold at the ends of the holding portions on the rotation center side, the rotation center portion is arranged on the mold side of the respective holding portions of the first outer frame and the second outer frame, the respective protrusions provided on the first outer frame and the second outer frame are arranged in abutment against the rotation center portion, and the outer frame portion bends in response to the respective protrusions moving around the rotation center portion. This allows a pulling force to be applied to the vicinity of the portion where the resin sheet is to be folded. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a vacuum forming apparatus capable of suppressing the occurrence of wrinkles in the vicinity of the folding points of a resin sheet when performing vacuum forming. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing a configuration of a vacuum forming apparatus according to a first embodiment. [Diagram 2] FIG. 1 is an enlarged view of a vacuum forming apparatus according to a first embodiment. [Diagram 3] 3A to 3C are diagrams illustrating a vacuum forming process and a state of a resin sheet according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First embodiment Hereinafter, a vacuum forming apparatus for a resin sheet according to the present embodiment will be described with reference to the drawings. The vacuum forming apparatus 1 is an apparatus that performs vacuum forming of a resin sheet 2 arranged in the vacuum forming apparatus 1. As shown in Fig. 1, the vacuum forming apparatus 1 includes a mold 11, an outer frame portion 12, a heating device 13, and an outer frame moving device 14. The resin sheet 2 is a thermoplastic resin sheet and contains polycarbonate.

[0010] For ease of explanation, as shown in Fig. 1, mold 11 is disposed below and heating device 13 is disposed above, and outer frame portion 12 and resin sheet 2 held by outer frame portion 12 are disposed between mold 11 and heating device 13. Fig. 2 is an enlarged view of the state in which outer frame portion 12 shown in Fig. 1 is in contact with mold 11 and bent, and the heating device 13 and outer frame moving device 14 are omitted.

[0011] The mold 11 has a generally convex shape with an apex at the center. As shown in Fig. 1, the mold 11 has a convex shape bent so that the ends in the left-right direction of the mold 11 are downward and the center is upward.

[0012] The outer frame portion 12 is composed of a first outer frame 21 disposed on the left side in FIGS. 1 and 2, a second outer frame 22 disposed on the right side, and a rotation center portion 23.

[0013] Here, the first outer frame 21 has a holding portion 211 that holds the resin sheet 2, and a protruding portion 212 that protrudes downward from the holding portion 211. Here, the left end of the holding portion 211 is referred to as a left end portion 211a, and the right end thereof is referred to as a right end portion 211b. In addition, the protruding portion 212 is formed to protrude downward from the right end portion 211b of the holding portion 211.

[0014] Similarly, the second outer frame 22 has a holding portion 221 that holds the resin sheet 2, and a protruding portion 222 that protrudes downward from the holding portion 221. Here, the left end of the holding portion 221 is referred to as a left end 221a, and the right end is referred to as a right end 221b. In addition, the protruding portion 222 is formed to protrude downward from the left end 221a of the holding portion 221.

[0015] 1 and 2, the right end 211b of the first outer frame 21 and the left end 221a of the second outer frame 22 are disposed adjacent to each other at approximately the same height. Furthermore, as shown in Fig. 1, before the outer frame portion 12 comes into contact with the upper part of the mold 11, the holding portion 211 of the first outer frame 21 and the holding portion 221 of the second outer frame 22 are disposed in an aligned state so as to be in a substantially straight line when viewed from the side.

[0016] 1 and 2, rotation center 23 is disposed below right end 211b of holding portion 211 of first outer frame 21 and below left end 221a of holding portion 221 of second outer frame 22. In other words, rotation center 23, which is the fulcrum for bending first outer frame 21 and second outer frame 22, is disposed outside the plane of resin sheet 2, that is, on the mold 11 side which is the inside when folded.

[0017] Furthermore, the rotation center 23 abuts against the protrusion 212 of the first outer frame 21, and serves as the rotation center when the first outer frame 21 rotates. Similarly, the rotation center 23 abuts against the protrusion 222 of the second outer frame 22, and serves as the rotation center when the second outer frame 22 rotates.

[0018] Here, the rotation center 23 may be any mechanism capable of bending the first outer frame 21 and the second outer frame 22, and may be, for example, a hinge.

[0019] Returning to Fig. 1, the heating device 13 is a heating device that heats the resin sheet 2 from one side in a non-contact manner. Here, the heating device 13 is disposed above the outer frame portion 12 and the resin sheet 2, and can heat the resin sheet 2 from above. Note that heating by the heating device 13 is not limited to heating from one side from above, but may be heating from one side from below or heating from both sides.

[0020] The outer frame moving device 14 is a device that moves the outer frame part 12. The outer frame moving device 14 can lower the outer frame part 12 from a state in which the outer frame part 12 provided with the resin sheet 2 is disposed a predetermined distance above the mold 11 until the resin sheet 2 comes into contact with the mold 11. More specifically, the outer frame moving device 14 can lower the outer frame part 12 so that the apex of the bend of the outer frame part 12 comes into contact with the apex of the mold 11, and can lower the end part of the outer frame part 12 so that the outer frame part 12 is bent to match the shape of the mold 11.

[0021] The outer frame moving device 14 can utilize a motor or the like that is driven by being supplied with power, but is not limited to this.

[0022] Generally, vacuum forming of a resin sheet is performed in the vacuum forming apparatus 1 according to the following procedure. Fig. 3(a) shows an example of the vacuum forming process, and Fig. 3(b) to Fig. 3(d) are diagrams showing examples of the state of the outer frame portion 12 and the resin sheet 2 in the process of Fig. 3(a).

[0023] First, the heating device 13 heats one side of the resin sheet 2 arranged on the outer frame portion 12 (step S1). At this time, the heating device 13 is provided above the outer frame portion 12 in a non-contact manner, and the mold 11 is arranged below the outer frame portion 12 in a separated state. FIG. 3(b) is an example of a top view of the outer frame portion 12 and the resin sheet 2 heated by the heating device 13.

[0024] Next, the outer frame moving device 14 moves the outer frame portion 12 downward until the lower side of the outer frame portion 12 and the resin sheet 2 come into contact with the upper surface of the mold 11. As a result, the outer frame portion 12 is bent around the rotation center 23 such that the left end 211a of the holding portion 211 of the first outer frame 21 and the right end 221b of the holding portion 221 of the second outer frame 22 are lowered (step S2). At this time, the resin sheet 2 is bent at the same time in response to the bending of the outer frame portion 12. FIG. 3(c) is a perspective view showing an example of a state immediately before the outer frame portion 12 is bent, and FIG. 3(d) is a perspective view showing an example of a state in which the outer frame portion 12 is bent.

[0025] Here, since the rotation center 23 of the outer frame portion 12 is provided below the holding portions 211, 221, when the outer frame portion 12 is bent around the rotation center 23, a pulling force is generated in the resin sheet 2 at the portion that is bent in response to the bending of the outer frame portion 12. In other words, a force is generated in the resin sheet 2 toward the left end portion 211a of the first outer frame 21 and a force is generated toward the right end portion 221b of the second outer frame 22, and the resin sheet 2 is in a pulled state.

[0026] Next, vacuum drawing is performed in the vacuum forming apparatus 1. As a result, the resin sheet 2 comes into close contact with the mold 11 (step S3). As a result, the vacuum forming apparatus 1 forms the resin sheet 2 by vacuum drawing.

[0027] Thereafter, in the vacuum forming apparatus 1, demolding is performed to remove the molded resin sheet 2 from the mold 11 (step S4). Then, in the vacuum forming apparatus 1, a trimming process is performed to remove excess portions from the demolded resin sheet 2 (step S5).

[0028] As a result, in the vacuum forming apparatus 1, by locating the fulcrum for folding the outer frame portion 12 outside the plane of the resin sheet 2, a pulling force is generated near the apex where the resin sheet 2 is folded, and it is possible to prevent wrinkles caused by excess material in the sheet. Therefore, the vacuum forming apparatus 1 can improve the accuracy of forming a vacuum formed product.

[0029] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present invention. In other words, the above description has been omitted or simplified as appropriate for the purpose of clarity, and a person skilled in the art can easily modify, add, or convert each element of the embodiment within the scope of the present invention.

[0030] For example, in the above description, the case where both ends in the left-right direction in FIG. 1 are folded is described, but a similar structure can also be adopted for folding in the depth direction in FIG. [Explanation of symbols]

[0031] 1 Vacuum forming equipment 2 Resin sheet 11-inch 12 Outer frame 13 Heating device 14 Outer frame moving device 21 First outer frame 22 Second outer frame 23 Rotation center 211 Holding part 211a Left end 211b Right end 212 Protrusion 221 Holding part 221a Left end 221b Right end 222 Protrusion

Claims

[Claim 1] A vacuum forming apparatus that bends and forms a resin sheet by contacting an outer frame portion that restrains the resin sheet against a mold, The outer frame portion is A first outer frame; A second outer frame; a rotation center portion that becomes a rotation center of the first outer frame and the second outer frame when the first outer frame and the second outer frame are driven to come into contact with the mold and the outer frame portion is bent, The first outer frame and the second outer frame are a holding portion against which the resin sheet abuts; a protrusion protruding toward the mold at an end of the holding portion on the side of the rotation center, the rotation center is disposed closer to the mold than the respective holding portions of the first outer frame and the second outer frame, The protrusions provided on the first outer frame and the second outer frame each include The outer frame portion is disposed in contact with the rotation center, and the outer frame portion is bent in response to the movement of each of the protrusions along the rotation center. Vacuum forming equipment.

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