JP2022104021A - Welding jig and molding method of molded body using jig - Google Patents

Abstract

To provide a welding jig capable of simultaneously welding resin sheets and removing excess resin sheets, thereby reducing manhour.SOLUTION: A welding jig has a pair of blades. At least one of the blades has a cut part for cutting and removing excess resin sheet and a weld part for welding the resin sheet connected to the cut part. Here, the cut part is formed as a corner part protruding toward the resin sheet. The corner part is formed by intersecting two inclined planes, and of these two inclined planes, the inclined plane with a smaller inclination angle to the resin sheet is the weld part. The weld part may have a separation part where the blade is retracted in connection with the weld part. In a molding method of a molded body for welding and integrating the pair of resin sheets into the molded body, the welding jig is used to simultaneously weld and integrate the resin sheets and cut and remove excess resin sheets.SELECTED DRAWING: Figure 4

Description

The present invention relates to a novel welding jig capable of deburring at the same time as welding, and further relates to a method for forming a molded product using a welding jig.

For example, as a method for manufacturing an automobile duct for ventilating air from an air conditioner, a blow method in which a foamed molten resin is molded by molding with a split mold is widely adopted. In blow molding, various types of ducts can be easily molded, and ducts having complicated shapes can be mass-produced.

However, in the production of a foam duct by blow molding, although a hollow body (duct) can be obtained in a small number of steps, there remains a problem that the expansion ratio is greatly limited and it is difficult to regulate the inner diameter.

Under such circumstances, a foamed resin sheet bonding duct for bonding a pair of vacuum-formed foamed resin sheets to a so-called hat shape (gutter shape) has also been proposed (see, for example, Patent Document 1).

Patent Document 1 discloses an air-conditioning duct in which a gutter-shaped duct half body is joined in a tubular shape and a method for manufacturing the same. As a manufacturing method, a foam sheet having a two-layer structure is heated to form a duct half body. A duct half body is formed by sucking a foam sheet having a two-layer structure and shaping it into a mold surface shape on the suction mold surface having the mold surface of the above, and the duct half bodies are joined to each other in a tubular shape. It is stated that.

Japanese Unexamined Patent Publication No. 2016-120735

The foamed resin sheet bonding duct has many advantages over blow-molded ducts, such as a high degree of freedom regarding the foaming ratio and the inner diameter can be reliably regulated by a mold or the like. When thinking about it, there is a problem that the number of man-hours is larger than that of blow molding. For example, in the case of a bonded duct, a process of welding a foamed resin sheet and a process of deburring to remove an excess resin sheet are required, but it is difficult to achieve both, and it is difficult to achieve both in manufacturing a bonded duct. This is a factor in the increase in man-hours.

The present invention has been proposed in view of such conventional circumstances, and can perform welding of a resin sheet and removal of an excess resin sheet at the same time, for example, reducing the number of steps when manufacturing a bonding duct. It is an object of the present invention to provide a welding jig that can be realized, and further, an object of the present invention is to provide a molding method of a molded product.

In order to achieve the above-mentioned object, the welding jig of the present invention is a welding jig having a pair of blades, and at least one of the blades has a cutting portion for cutting and removing an excess resin sheet and the cutting portion. It is characterized by having a welded portion for welding a continuous resin sheet.

Further, the molding method of the molded body of the present invention is a molding method of a molded body in which the molded bodies of a pair of resin sheets are welded and integrated, and the welding jig is used to weld and integrate the resin sheets and excess resin. It is characterized in that the sheet is cut and removed at the same time.

The welding jig of the present invention has a cutting portion and a welding portion, and a step of welding a resin sheet and a step of deburring removing a surplus resin sheet are performed at the same time. As a result, man-hours can be reduced.

According to the present invention, it is possible to weld the resin sheet and remove the excess resin sheet at the same time, and it is possible to reduce the number of man-hours when manufacturing the bonded duct, for example.

It is a schematic sectional drawing which shows an example of the foam resin sheet bonding duct. It is a figure which shows the molding process of the foam resin sheet bonding duct, (A) is a schematic cross-sectional view which shows the combination of a pair of molded foam resin sheets, (B) is the schematic sectional view which shows the welding and deburring process. .. It is a schematic perspective view of the welding jig used for welding and deburring of a foamed resin sheet. It is a figure which shows the welding and deburring process by a welding jig, (A) is a schematic cross-sectional view which shows the state which the blades of a welding jig are arranged facing each other, (B) is the schematic sectional view which shows the welding and deburring state. be. It is a figure for demonstrating the shape of a welding jig.

Hereinafter, embodiments of a welding jig to which the present invention is applied and a method for forming a molded product using the same will be described in detail with reference to the drawings. In the present embodiment, a foamed resin sheet bonding duct will be described as an example as a molded body to which the welding jig is applied.

As shown in FIG. 1, the foamed resin sheet bonding duct 1 is a foamed duct having a rectangular cross section by combining two foamed resin sheets 2 and 3 formed in a so-called hat shape, and is supplied from, for example, an air conditioner unit. It is a lightweight automobile duct for distributing the cold and warm air to a desired part. The hat shape is a shape that is analogically referred to because it resembles a cross section of a hat (hat), and is a shape that bulges into a rectangular shape.

The cross-sectional shape of the foamed resin sheet bonding duct 1 is not limited to the rectangular shape as shown in the example shown in FIG. It may be.

In any shape, the flange portions 2A and 3A are formed on the foamed resin sheets 2 and 3, respectively, and the flange portions 2A and 3A are overlapped and welded to form the foamed resin sheets 2 and 3. It is integrated and the foamed resin sheet bonding duct 1 is formed.

Each of the foamed resin sheets 2 and 3 is formed by vacuum-molding a foamed sheet obtained by adding a foaming agent to a thermoplastic resin, for example, into a hat shape or a gutter shape. The thermoplastic resin to be used is, for example, polypropylene-based. Examples thereof include resins, and blend resins in which 1 to 20% by mass of a polyolefin polymer and 5 to 40% by mass of a hydrogenated styrene-based thermoplastic elastomer are mixed can also be used.

Examples of the foaming agent include a physical foaming agent, a chemical foaming agent and a mixture thereof. Examples of the physical foaming agent include inorganic physical foaming agents such as air, carbon dioxide gas, nitrogen gas, and water, organic physical foaming agents such as butane, pentane, hexane, dichloromethane, and dichloroethane, and supercritical fluids thereof. Can be applied. As the supercritical fluid, it is preferable to make it using carbon dioxide, nitrogen, etc., for nitrogen, the critical temperature is -149.1 ° C, the critical pressure is 3.4 MPa or more, and for carbon dioxide, the critical temperature is 31 ° C, the critical pressure. It can be made by setting it to 7.4 MPa or more.

The foaming ratio of each of the foamed resin sheets 2 and 3 is arbitrary, and is composed of, for example, a closed cell structure having a plurality of bubble cells (with a closed cell ratio of 70% or more). In the case of a duct obtained by molding and combining foamed resin sheets 2 and 3, it is possible to form a duct having a higher degree of freedom in foaming ratio than a duct formed by blow molding, for example, a duct having a higher foaming ratio than a blow molded duct. Is. As a specific numerical value of the foaming ratio, for example, it can be 10 times or more, preferably 15 times or more, and further 20 times or more. The upper limit of the foaming ratio varies depending on the type of the thermoplastic resin used and the like, but is, for example, 30 times or less. By increasing the foaming ratio, the weight of the duct can be reduced, and the heat insulating performance and the soundproofing performance can be improved.

FIG. 2 shows a molding process of the foamed resin sheet bonding duct 1. In order to form the foamed resin sheet bonding duct 1, first, the foamed resin sheets 2 and 3 are formed into a hat shape having flange portions 2A and 3A by vacuum forming, thermoforming or the like.

Next, as shown in FIG. 2A, the flange portions 2A and 3A of the foamed resin sheets 2 and 3 are overlapped with each other so as to face each other so that a rectangular space is formed inside. After that, as shown in FIG. 2B, the flange portions 2A and 3A of the foamed resin sheets 2 and 3 are welded and integrated, and the excess portion Y at the tip of the flange portions 2A and 3A is cut off (burring). Take).

Welding of flanges 2A and 3A and cutting of excess portion Y have been difficult to achieve at the same time and have been performed as separate processes. Improvement is desired in terms of points. Therefore, in the present invention, by devising the blade shape of the welding jig used for welding, it has been improved so that the welding process and the deburring process can be performed at the same time. Hereinafter, the welding jig used in this embodiment will be described.

As shown in FIGS. 3 to 5, the welding jig has a pair of blades 11 and 12 facing each other with the two foamed resin sheets 2 and 3 interposed therebetween. The foamed resin sheets 2 and 3 are sandwiched between the pair of blades 11 and 12, and the foamed resin sheets 2 and 3 are welded and the excess portion is cut (deburring).

Each of the blades 11 and 12 has corner portions 11A and 12A protruding toward the foamed resin sheets 2 and 3, and when these corner portions 11A and 12A abut against each other, the foamed resin sheets 2 and 3 are cut off. Take shape. That is, the surplus portion Y is removed (deburring).

In the case of this example, the surplus portion Y is cut off by abutting the corner portions 11A and 12A, but it is also possible to cut the surplus portion Y by using, for example, a scissors-shaped shear structure.

Corner portions 11A and 12A are formed on the blades 11 and 12 by intersecting two inclined surfaces (inclined surface 11B and inclined surface 11D, inclined surface 12B and inclined surface 12D), and these corner portions 11A, With 12A as the tip, inclined surfaces 11B and 12B and inclined surfaces 11D and 12D are formed on both sides thereof. Here, the inclined surfaces 11D and 12D on the surplus portion Y side of the foamed resin sheets 2 and 3 are steep slopes with respect to the foamed resin sheets 2 and 3, and are formed from the surplus portion Y of the foamed resin sheets 2 and 3. It is shaped so that it can be quickly separated.

On the other hand, the inclined surfaces 11B and 12B are gentler inclined surfaces than the inclined surfaces 11D and 12D, and by sandwiching the foamed resin sheets 2 and 3 between the inclined surfaces 11B and 12B, the foamed resin sheet 2 , 3 are configured to be welded. That is, the inclined surfaces 11B and 12B (region A in FIG. 5) are welded portions.

The inclination angle θ of the inclined surfaces 11B and 12B with respect to the foamed resin sheets 2 and 3 is smaller than the inclination angle of the inclined surfaces 11D and 12D with respect to the foamed resin sheets 2 and 3, and is set in the range of, for example, 5 ° to 20 °. There is. The inclination angle θ is preferably optimized according to the thickness of the foamed resin sheets 2 and 3 and the welding size. Smooth welding is difficult if the inclination angle θ is too large or too small.

By installing the heater in the region corresponding to the inclined surfaces 11B and 12B of the blades 1 and 12, the foamed resin sheets 2 and 3 sandwiched between the inclined surfaces 11B and 12B can be quickly welded.

The welding jig of the present embodiment has the separating portions 11C and 12C in which the blade is retracted in connection with the welding portions (inclined surfaces 11B and 12B). The separation portions 11C and 12C (region B in FIG. 5) form a space for retracting the foamed resin sheets 2 and 3 from each other. For example, vacuum suction holes are provided in the separation portions 11C and 12C, and the foamed resin is provided on the surface thereof. If the sheets 2 and 3 are elastically deformed and sucked and held, welding of the foamed resin sheets 2 and 3 in this region is restricted. That is, the foamed resin sheets 2 and 3 are welded only to the inclined surfaces 11B and 12B (region A in FIG. 5) which are welded portions, and the welded end is restricted to the point C in FIG.

The tips of the separating portions 11C and 12C are inclined surfaces 11E and 12E, respectively, and are separated from the foamed resin sheets 2 and 3, respectively.

Next, a welding / cutting process using the above-mentioned welding jig will be described. In order to simultaneously weld the foamed resin sheets 2 and 3 and cut off the excess portion using the welding jig of the present embodiment, as shown in FIG. 4A, the pair of blades 11 and 12 are attached to the foamed resin sheet 2. , 3 are arranged so as to face each other, and as shown in FIG. 4B, the corner portions 11A and 12A of the blades 11 and 12 are abutted against each other. As a result, the excess portion Y of the foamed resin sheets 2 and 3 is cut off. At this time, the surplus portion Y may be completely cut and removed at this stage by abutting the corner portions 11A and 12A of the blades 11 and 12, or the cut portion exists as a cutting line and the surplus portion Y is removed. It may be separated by pulling.

By abutting the blades 11 and 12, at the same time as cutting off the excess portion Y, the foamed resin sheets 2 and 3 are sandwiched between the inclined surfaces 11B and 12B, and welding is performed. By sandwiching the foamed resin sheets 2 and 3 between the inclined surfaces 11B and 12B, the crimping strength gradually changes from the surplus portion Y side to the product side (to the right in FIG. 4), and the welding allowance and welding strength are increased. Secured.

The thickness of the welded portion after molding is not constant, it is thin on the surplus portion Y side and thick on the product side. Therefore, it is possible to obtain a molded product having higher rigidity against bending and superior strength as compared with the product welded by the conventional method.

Further, in the separated portions 11C and 12C connected to the welded portions (inclined surfaces 11B and 12B), the foamed resin sheets 2 and 3 are suction-held on the surface thereof by vacuum suction or the like, so that erroneous melting due to residual heat is prevented. This makes it possible to clarify the boundaries of the welded portion, which facilitates product warranty.

As described above, in the welding jig and the molding method of the molded body of the present embodiment, the welding of the resin sheet and the removal of the excess resin sheet can be performed at the same time, and the man-hours for manufacturing the bonded duct can be reduced. It is possible. In addition, in the molding of foam ducts, heating, shaping, and welding are conventionally performed with a large dedicated machine, making it difficult to handle small lot production, and it takes a lot of time for partial shape correction and maintenance. There is a problem that it costs money. The welding jig of the present embodiment has an advantage that it can be used for molding both large and small molded products, and simple trial production can be easily performed.

Although the embodiments to which the present invention has been applied have been described above, it goes without saying that the present invention is not limited to the above-described embodiments, and various changes may be made without departing from the gist of the present invention. It is possible.

For example, the molded body molded by using a welding jig is not limited to the foamed resin sheet bonding duct, and can be applied to the molding of various types of molded bodies (molded bodies formed by molding a resin sheet). It is possible. Further, the resin sheet is not limited to the foamed resin sheet, and may be, for example, a non-foamed (solid) resin sheet. The pair of blades have the same shape in the previous embodiment, but it is also possible that only one blade has the above-mentioned shape and the other has a different shape (for example, a flat shape).

1 Foam resin sheet bonding duct 2, 3 Foam resin sheet 2A, 3A Flange portion 11, 12 Blade 11A, 12A Square portion 11B, 12B Inclined surface (welded portion)
11C, 12C Separation part Y Surplus part

Claims (8)

A welding jig with a pair of blades
At least one blade is a welding jig characterized by having a cutting portion for cutting and removing an excess resin sheet and a welding portion for welding the resin sheet connected to the cutting portion. The cut portion is formed as a corner portion protruding toward the resin sheet, and the corner portion is formed by intersecting two inclined surfaces, and the corner portion is formed with respect to the resin sheet of one of the two inclined surfaces. The welding jig according to claim 1, wherein the inclination angle is smaller than the inclination angle of the other inclined surface with respect to the resin sheet, and the inclined surface having the small inclination angle is the welding portion. The welding jig according to claim 2, wherein the inclination angle of the welded portion with respect to the resin sheet is 5 ° to 20 °. The welding jig according to any one of claims 1 to 3, wherein the welding jig has a separating portion in which the blade is retracted in connection with the welding portion. The welding jig according to claim 4, wherein a vacuum suction hole is formed on the surface of the separated portion facing the resin sheet. It is a molding method of a molded body in which a molded body of a pair of resin sheets is welded and integrated.
A method for forming a molded product, which comprises using the welding jig according to any one of claims 1 to 5 to simultaneously perform welding integration of the resin sheet and cutting and removal of the excess resin sheet. The method for molding a molded product according to claim 6, wherein the resin sheet is a foamed resin sheet. The method for molding a molded body according to claim 7, wherein the molded body is a foamed resin sheet bonding duct.

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