JP3115012B2 - Method and apparatus for manufacturing thick-walled tubular body made of foamed resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a thick-walled tube made of a foamed resin, which is used as a heat retaining member such as a heat medium feed pipe for air conditioning.

[0002]

2. Description of the Related Art Conventionally, a tubular body made of a heat-resistant foamed resin has a very wide range of application fields.
Integrally molding the foamed resin into a tube not only involves various difficulties such as in molding technology, especially for those having a large wall thickness and a large diameter, but also it is not possible to form a pipe body for each various diameters. Manufacturing efficiency is extremely poor. For this reason, a technique has been adopted in which one foamed resin sheet is curved and formed into a cylindrical shape and both ends facing each other at the time of bending are fused.

However, in this method, when manufacturing pipes of various diameters, particularly those having a large thickness, it is difficult to obtain a thick foamed resin sheet. Etc. are likely to occur and the yield is poor.

[0004] Therefore, in order to solve the problem in manufacturing such a thick-walled tubular body, for example, one disclosed in Japanese Patent Application Laid-Open No. 2-160535 has been disclosed. according to this,
A plurality of foamed resin sheets having different sheet widths in a stepwise manner are prepared in a state of being laminated so that the sheet width gradually increases, and this is inserted between a pair of pressure rolls, and each foamed resin sheet is immediately before the insertion. Sending hot air in between,
The laminated foamed resin sheet is formed into a forming member (forming die).
By fusing both ends in the sheet width direction,
Thus, a thick-walled pipe (pipe cover) Q as shown in FIG. 8 is formed. Therefore, the thick-walled tube Q manufactured by such a method is connected to the respective joints Q of the foamed resin sheets Q1, Q2, and Q3 constituting the tube Q.
a, Qb, and Qc are formed at the same location on the pipe circumference.

[0005]

However, in the configuration of the prior art as described in the above-mentioned publication, since the foamed resin sheet curved and formed by the molding member has a considerable thickness, the elasticity of the foamed resin material is increased. As a result, the joints Qa, Qb, Qc at both ends of each foamed resin sheet Q1, Q2, Q3 are easily separated from each other. As a result, as the number of foamed resin sheets to be laminated increases, in other words, the wall thickness increases. Hod Q
Defective products easily occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a thick-walled pipe capable of always producing a good product even with a thick-walled pipe, and an object of the present invention.

[0007]

According to a first aspect of the present invention, there is provided a first step of preparing a plurality of raw foamed resin sheets having different sheet widths in a stepwise manner. A second step of joining both end portions in the sheet width direction of the first foamed resin raw sheet having the first sheet width of the anti-sheet, and the above-mentioned around the core tube body formed by the step; The second foamed resin raw sheet having a second sheet width wider than the first sheet width is formed by joining a joint portion at both ends thereof to a joint portion of the core tube in a circumferential direction of the core tube. And a third step of laminating at predetermined intervals.

Further, according to the present invention, a first sending means for sending out the first raw foamed resin sheet, and both ends of the fed first foamed resin raw sheet in the sheet width direction are provided. A guide member for curving the portions so as to face each other, heating means provided near the guide member for heating the first foamed resin raw sheet, and provided subsequent to the guide member; A pair of formed belts, each having a belt surface facing each other, and a guide groove having a semicircular cross section formed on each of both belt surfaces along the belt length direction.
A step forming section and a step section provided subsequent to the first step forming section;
Second feeding means for feeding the second raw foamed resin sheet, and a guide member for bending the fed second foamed resin raw sheet so that both ends in the sheet width direction are opposed to each other. The second member provided near the guide member.
Heating means for heating the foamed resin raw sheet of, and provided subsequent to the guide member, the belt surfaces face each other,
And, a pair of formed belts each having a guide groove having a semicircular cross-section formed on both belt surfaces along the belt length direction,
And a second-stage molding portion comprising:

[0009]

When the first foamed resin sheet passes through the first-stage molded portion, a core tube is formed. When the core tube passes through the second-stage molded portion together with the second foamed resin sheet, The second foamed resin sheet is laminated around the core tubular body to form a two-layer thick-walled tubular body. In this case, the joint of the second foamed resin sheet is formed by joining the first foamed resin sheet. The portion is formed at a position slightly separated in the circumferential direction of the core tube.

[0010]

FIG. 1 shows an embodiment of the present invention.
The manufacturing apparatus includes a first-stage forming section 1 and a second
The first and second forming sections 1 and 2 have forming belts 3, 4 and 5 and 6, respectively, which are arranged in upper and lower two steps. Here, the two forming portions 1 and 2 are disposed so as to cascade along the running direction of the belt, and the forming belts 3 and 4 are formed of a pair of pulleys 3A and 3A.
B, are wound around pulleys 4A and 4B, respectively. Similarly, the forming belts 5 and 6 are wound around a pair of pulleys 5A and 5B and pulleys 6A and 6B, respectively.

Also, the first and second stage forming sections 1,
The first material reel 7 is disposed on each of the introduction sides (left side in FIG. 1) of
(First sending means) and a second material reel 8 (second sending means) are provided, respectively.
The foamed resin sheet 7A is wound around the second raw material reel 8 with the second foamed resin sheet 8A, and the first foamed resin sheet 7A is formed wider than the second foamed resin sheet 8A. Have been.

Further, first and second feed rolls 9 and 10 are arranged on the lead-out side (right side in FIG. 1) of the first material roll 7 in that order. On the side, the first heater 11A, the first primary forming guide 12 as a guide member
And a second secondary forming guide 13 are provided in that order, and a second heater 11 </ b> B is provided above the lead-out side of the first primary forming guide 12. Similarly, third and fourth feed rolls 14 and 15 are arranged in this order on the outlet side of the second raw material reel 8, and the first heater 16 </ b> A, A second primary forming guide 17 and a second secondary forming guide 18, which are other guide members, are provided in that order, and a second heater 16B is provided above the second primary forming guide 17. Here, the first heater 11
A, 16A and the second heaters 11B, 16B are configured to have nozzles for blowing hot air onto the product.

As understood from FIG. 3, the second
Primary forming guide 17 (same for first primary forming guide 12)
Has a tubular shape as a whole, is expanded in the form of a skirt crack from the middle part toward the introduction side, and has a circular hole 17a formed from the middle part toward the outlet side.

A relay roll 19 is provided between the first-stage forming portion 1 and the second-stage forming portion 2, and a guide tube 20 is provided on the outlet side of the relay roll 19. ing.

FIG. 2 shows details of the vicinity of the introduction-side end of the second-stage molding portion 2 (the same applies to the first-stage molding portion 1). As shown in detail in FIG. 4, the upper forming belt 5 and the lower forming belt 6 have forming holes 5 having a semicircular cross section.
a and 6a are formed so as to face each other, and a circular guide hole is formed by the two forming holes 5a and 6a.

As shown in FIGS. 2 and 5, the second primary forming guide 17 (similar to the first primary forming guide 12) has a guide hole 17a whose diameter is reduced from the introduction side to the discharge side.
As shown in FIGS. 2 and 5, a guide hole 18a having a semicircular cross section is formed in the second secondary forming guide 18 (the same is true for the first secondary forming guide 13).
Has a radius reduced from the introduction side to the exit side, and the curved surface faces downward.

Next, the operation of the embodiment constructed as described above will be described. The first foamed resin sheet 7A unwound from the first web reel 7 is entirely in the first heater 1
While being heated by 1A, it is inserted into the first primary molding guide 12, and at least both ends in the sheet width direction are heated by the second heater 11B to form a first molded body having a substantially C-shaped cross section. .

Subsequently, when the first molded body having the C-shaped cross section is inserted into the first secondary molding guide 13, the heated opposite ends are fused to form the first semi-molded body having an annular cross section. A core tube is formed.

Further, the first semi-molded core tube becomes a first core tube 21 formed in a state of being pressed between the molding holes 3a, 4a of the belts 3, 4, and the first core tube 21 is formed. The first bonding portions 21a at both ends are fixed to 21 (see FIG. 6).

The first core tube 21 passes through the guide tube 20 via the relay roll 19 and thereafter is inserted into the second primary forming guide 17. At this time, the second foamed resin sheet 8A is fed from the second raw material reel 8, and the second foamed resin sheet 8A is transferred to the second primary forming guide 17 so as to cover the first core tube 21. Inserted.

Here, the second foamed resin sheet 8A is entirely formed in the first heater 16A in the same manner as in the case of the first foamed resin sheet 7A inserted into the first primary molding guide 12.
The sheet is inserted into the second primary forming guide 17 in a state where the sheet is heated by the heating, and both ends in the sheet width direction are heated by the second heater 16B to form a second formed body having a substantially C-shaped cross section. Subsequently, when the second molded body is inserted into the second secondary molding guide 18, the opposite heated ends of the second foamed resin sheet 7A are fused (see FIG. 5), and a two-layer structure is formed. A second semi-molded core tube is formed. Further, the second semi-molded core tube becomes a second core tube 22 molded in a state of being pressed between the molding holes 3a, 4a of both belts 3, 4, and both ends of the second foamed resin sheet 8A. The second joint portion 22a of the portion is fixed.

As shown in FIG. 6, the second core tube 2
2 is formed such that the second joint portion 22a is separated from the first joint portion 21a by a predetermined distance in the circumferential direction of the core tube body 22. Therefore, for example, the second foamed resin sheet 8A
Is inserted into the second primary molding guide 17 to adjust the interval.

In the above embodiment, the molded portion is formed in two stages. However, it is a matter of course that a configuration having three or more molded portions can be made according to the specifications of the product. FIG. 7 shows an example of a thick-walled tube 23 having a three-layer structure. Needless to say, the third foamed resin sheet 2 forming the third layer
4 is a bonding portion 21a of the first and second layers.
a, 22a.

When the thickness of the foamed resin sheet constituting each layer is too thin, it is effective to laminate a plurality of thin sheets in advance to increase the thickness.

[0025]

As described above, according to the first aspect of the present invention,
A first step of preparing a plurality of foamed resin raw sheets having different sheet widths in a stepwise manner, and a sheet width of the first foamed resin raw sheet having the first sheet width among the foamed resin raw sheets A second step of joining both end portions in the direction, and a second foamed resin material having a second sheet width wider than the first sheet width around the core tube formed by the step. A third step of laminating the sheet so that the joints at both ends thereof are joined with the joints of the core tube at predetermined intervals in the circumferential direction of the core tube. The elasticity of each component of the thick-walled pipe as a product is dispersed, and the occurrence of defective products in the pipe can be prevented.

According to the second aspect of the present invention, the first feeding means for feeding the first raw foamed resin sheet is provided;
A guide member for curving the fed first foamed resin raw sheet so that both ends in the sheet width direction face each other, and the first foamed resin raw sheet provided near the guide member And heating means for heating the guide member, and guide grooves having a semicircular cross section are formed on both belt surfaces so as to extend along the belt length direction. A first forming section comprising a pair of formed forming belts, and a second feeding means provided subsequent to the first forming section for feeding out a second raw foamed resin sheet. A guide member for curving the fed second foamed resin sheet so that both ends in the sheet width direction are opposed to each other; and a second foamed resin sheet provided near the guide member. Heating means for heating the sheet; A pair of formed belts, each of which has a belt surface facing each other, and a guide groove having a semicircular cross section formed on both belt surfaces along the belt length direction. And a molding portion, so that the invention of claim 1 can be easily configured by diverting the conventional components.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an apparatus provided for carrying out a manufacturing method of the present invention.

FIG. 2 is an enlarged cross-sectional view showing the vicinity of an introduction-side end of a second-stage forming section.

FIG. 3 is a plan view taken along line WW of FIG. 1;

FIG. 4 is a sectional view taken along line XX of FIG.

FIG. 5 is a sectional view taken along the line YY of FIG. 1;

FIG. 6 is a sectional view taken along the line ZZ in FIG. 1;

FIG. 7 is a perspective view showing a process of manufacturing a thick-walled tube having a three-layer structure.

FIG. 8 is an end view for explaining a configuration of a thick-walled tube manufactured by a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st stage molding part 2 ... 2nd stage molding part 3, 4 ... molding belt 5, 6 ... molding belt 7A ... 1st foaming resin sheet 8A ... 2nd foaming resin sheet 12 ... 1st primary molding guide ( Guide member) 13: First secondary forming guide (guide member) 17: Second primary forming guide (guide member) 18: Second secondary forming guide (guide member) 21: Core tube 22: Thick tube

Claims (2)

(57) [Claims] 1. A first step of preparing a plurality of raw foamed resin sheets having different sheet widths in a stepwise manner, and a first foamed resin raw material having a first sheet width among the foamed resin raw sheets. A second step of joining both ends of the anti-sheet in the sheet width direction, and around the core tube body formed by the step,
A second foamed resin sheet having a second sheet width wider than the first sheet width is formed by joining a joint portion at both ends thereof to a joint portion of the core tube in a circumferential direction of the core tube. And a third step of laminating the pipes at predetermined intervals. 2. A first feeding means for feeding out a first foamed resin raw sheet, and the sent first foamed resin raw sheet is curved such that both ends in the sheet width direction are opposed to each other. A guide member for causing the first foamed resin raw sheet to be provided in the vicinity of the guide member, and a heating means for heating the first foamed resin raw sheet, and provided subsequent to the guide member; And a pair of forming belts having a pair of forming belts each having a guide groove having a semicircular cross section formed along both belt surfaces along the belt length direction. A second feeding means provided subsequently to feed the second raw foamed resin sheet, and the second raw foamed resin sheet fed so that both ends in the sheet width direction face each other. A guide member for bending, and a guide member provided near the guide member. A heating means for heating the second foamed resin sheet, and a heating means provided subsequent to the guide member, wherein the belt surfaces are opposed to each other, and both of the belt surfaces are cross-sectioned along the belt length direction. An apparatus for manufacturing a thick-walled pipe, comprising: at least a second-stage forming portion including a pair of forming belts each having a semicircular guide groove formed therein.