JPH0510205B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a foamed resin heat insulating cover and a manufacturing apparatus used for the manufacturing, and specifically relates to a foamed resin heat insulating cover used for pipes, etc. When manufacturing two-piece insulation covers that are mainly used for curved pipe parts such as elbows, the two pieces are molded at the same time so that foaming pressure is evenly applied to the manufacturing equipment, and the insulation material is applied to the inner mold. Prevent heat dissipation by using
The present invention relates to a method for producing a heat insulating cover made of foamed resin, which makes it possible to eliminate the residual heat of the mold or shorten the preheating time, and to reduce the weight of the mold by using a thin plate for the outer mold, and to an apparatus for manufacturing the same.

Liquefied natural gas and liquefied petroleum gas have been widely used as fuel for power generation and city gas due to the effects of the recent oil crises and for the purpose of controlling pollution. As is well known, since these liquefied gases are stored or transported at low temperatures, their storage tanks, piping, etc. must be insulated. These storage tanks, piping, etc. have recently become larger and larger. Taking piping as an example, the size ranges from 20 ^B to 40 ^B , and the insulation thickness needs to be 150 to 250 mm. FIG. 1 (A is a sectional view, B is a front view) is a diagram showing an example of such a piping insulation method. In the figure, a heat insulating cover 2 is attached to the outside of the pipe 1. The heat insulating cover 2 has the shape of a cylinder divided in half, and is molded to a predetermined length for ease of handling. Meji 3 is filled between the piping 1 and the heat insulating cover 2 and between the heat insulating covers 2 and fixed to each other. When the diameter of the pipe is large and the insulation thickness is large, a heat insulation cover with a cylinder divided into three or four parts may be used.

Foaming urethane resin is often used as the material for this heat insulating cover. This is because, in addition to its extremely excellent insulation performance, it can be easily foamed on-site, which has the advantage of significantly reducing transportation costs.

Conventionally, a heat insulating cover made of this foamable urethane resin has been molded using a mold as shown in FIG. 2 (perspective view). That is, in the figure, the mold 11 has a female mold 12, a male mold 13, and two end plates 14.
It consists of A half-cylindrical space 12A having a diameter approximately equal to the outer diameter of the required heat insulating cover is provided in the center of the female mold 12.
A half-cylindrical convex portion 13A having an outer diameter approximately equal to the inner diameter of the required heat insulating cover is provided at the center of the heat insulating cover 3 . The lengths of the space portion 12A and the convex portion 13A are both made to substantially match the length of the required heat insulating cover. The end plate 14 is a plate having a height and width approximately equal to the height and width of the female mold 12.

The following procedure is used to mold a heat insulating cover using this mold 11.

Two end plates 14 are attached to the female mold 12.

Set the male mold 13 onto the female mold 12.

The female mold 12 and the male mold 13 are tightened using a tightening tool (not shown in FIG. 2).

Mix and stir the foaming urethane resin stock solution.

A foamable urethane resin stock solution is poured into the space 12A of the female mold 12.

After foaming and a predetermined curing period after foaming, the mold is disassembled in the reverse order to take out the heat insulating cover 2 (shown on the recess 12A of the female mold 12 in FIG. 2).

The conventional method of forming a heat insulating cover described above did not have any major drawbacks while the size of the heat insulating cover was small, but as the size of the heat insulating cover gradually increases, the following drawbacks appear. It became.

When foaming urethane resin, foaming pressure is applied to each part of the mold, which tends to cause mold deformation.Especially, half-split molds have a mechanically disadvantageous shape against pressure, so the mold should be made with a thick wall and rigid structure. It is necessary to have a high degree of strength, and the mold is effective.

Since each component of the mold is heavy, it takes a lot of time to disassemble and assemble it, and a large crane is also required, which increases equipment costs and ultimately increases the cost of the heat insulating cover.

It is desirable to preheat the mold to 40° to 50°C to promote foaming, but since each component is thick, it has a large heat capacity, takes time to heat, and wastes heating energy. many.

Insulating covers are needed not only for straight pipes, but also for curved pipes such as elbows, but the molds used to mold such insulating covers for curved pipes are more irregular than those for straight pipes, and require material mechanics. Since it has a more disadvantageous shape in terms of its shape, the disadvantages mentioned above are even greater than those for straight pipes.

The present invention solves the above-mentioned drawbacks of the conventional manufacturing method for foam resin insulation covers, and provides a method for easily and inexpensively manufacturing high-quality foam resin insulation covers, and a manufacturing apparatus used in the manufacturing method. is intended to provide.

The present invention focuses on the fact that a curved pipe with strong pressure resistance against internal pressure can be easily made by joining thin plates of metal etc., and uses this for the main part of the outer mold, and also uses a curved pipe that can withstand external pressure such as foam glass. The pressure is strong;
Moreover, we focused on the fact that there are materials with good insulation performance,
The above objective is achieved by using this for the main part of the inner mold.

Embodiments of the present invention will be described below based on the drawings. FIG. 3 is an exploded perspective view showing an apparatus for manufacturing a foamed resin heat insulating cover according to the present invention. In the figure, the manufacturing equipment includes an inner mold 21 and a pair of upper and lower outer molds 3.
It consists of one or four ring frames 41, several fasteners 42, etc. 4 to 8 (in each case, A is a front view and B is a right side view) are views showing details of the components of the inner mold 21. That is, the fourth
The flat plate 22 shown in the figure is a part of a ring and has a substantially fan-like shape, and engaging protrusions 22A are provided at both ends of both surfaces thereof. What is shown in Fig. 5 is the mandrel 23, which includes a part of the annular plate (the one shown is approximately 1/4 part) and a part of the halved donut (the one shown is approximately 1/4 part). The engagement recess 23A that engages the engagement protrusion 22A described above is provided at both ends of the flat portion.

Figure 6 shows reinforcing material 24 made of cloth, asphalt roofing, etc., and Figure 7 shows 24 restraining metals (large).
5. A retainer (small) 26 is shown in FIG. The reinforcing member 24 has a shape similar to the developed view of the outer surface of the mandrel 23 described above, and the retainer (large) 25 and retainer (small) 26 are both approximately part of an annular plate (the one shown is a circle). It has the shape of 1/4 part of the ring plate).
The inner mold 21 has a pair of core metals 23 on both sides of a flat plate 22,
It is attached by engaging the engagement recess 23A with the engagement protrusion 22A, and then the reinforcing member 24 is attached to the outer surface of the mandrel 23 (this state is shown in the center of FIG. 3). , Furthermore, on the outer surface and inner surface portion of the core metal 23, a presser metal (large) 25,
Each pair of retainers (small) 26 are attached to the flat plate 22 with the end portions of the reinforcing material 24 sandwiched therebetween. The assembly of the inner mold 21 is now completed.

FIG. 9 shows the outer mold 31, with A being a front view and B being a right side view. In the same figure, the outer mold 31 is a part of an approximately half-split hollow donut-shaped ring formed from a thin plate of metal (in the case of this figure, it is a quarter of the ring).
It consists of a cover plate 32 having the shape of , and a flange 33 attached to the outer half of the cover plate 32. A resin injection port 34 is bored near the inner side of the cover plate 32, and a plurality of protrusions 35 are formed on the inner surface of the semicircular openings at both ends of the cover plate 32.
is removably attached with screws etc.

FIG. 10 shows the ring frame 41, with A being a front view and B being a right side view. In the figure, a ring frame 41 is made of a half-circular plate. FIG. 11 is a perspective view showing the stop plate 43, and FIG. 12 is a perspective view of the stop metal fitting 42. In both figures, the stop plate 43 is made of a rectangular plate, and the stop metal fitting 42 has a shape and structure similar to a so-called cylindrical vice.

Next, a method for manufacturing a foamed resin heat insulating cover using the manufacturing apparatus described above will be explained according to its process steps.

(a) A pair of outer molds 31 for an assembled product of inner mold 21
is attached, and the thickness of the space forming a part of the half-split hollow donut-shaped ring formed by the outer surface of the core metal 23 of the inner mold and the inner surface of the cover plate 32 of the outer mold is constant. After that, the flat plate 22 of the inner mold and the outer flange 33 are fixed using the fasteners 42.

(b) Four ring frames 4 are installed in the opening of the end face of the space forming a part of the half-split hollow donut-shaped ring.
1 is inserted, the inner surface of the protrusion 35 of the outer mold is brought into contact with the outer surface of the ring frame 41, and the eight stop plates 43 are attached to the legs of the ring frame 41.
3 and the flat plate 22 of the inner mold are fixed using a fastener 42. The assembly of the manufacturing apparatus is completed in this step, and the completed state is as shown in FIG. 13 (A is a front view, B is a bottom view). In order to simplify the drawings, the stopper 42 is shown only along its center line in this figure and in FIG. 14, which will be described later.

(c) Inject foamed resin from the resin injection port 34 of the outer mold. It goes without saying that for this injection, preparations such as mixing the foamable resin stock solution must be made in advance. In addition, it is desirable that the injection be carried out using the method shown in FIG. That is, the manufacturing apparatus is placed on a horizontal surface of a workbench or the like 44 so that its resin injection port is directly above it, and resin is injected as shown by arrow X.

(d) After a predetermined curing period, the stopper 42
is removed, the inner mold 21, outer mold 31, and ring frame 41 are divided and the molded product is taken out.

Although the manufacturing method and manufacturing apparatus for the foamed resin insulation cover described above were mainly for 90° elbows, the present invention is also effective for insulation covers for 45° elbows, 135° elbows, U-bends, etc. It goes without saying that it can be implemented. It goes without saying that the present invention can also be effectively applied to a heat insulating cover for straight pipes.

In the present invention, by molding the two divided pieces at the same time when manufacturing the heat insulation cover in two, it is possible to prevent excessive force from acting on the manufacturing equipment, and to make the cover plate of the outer mold a thin sheet of metal or the like. The mold is made lighter by using a heat insulating material in the core of the inner mold to prevent heat dissipation, resulting in the following excellent effects: There is.

The weight of the mold can be reduced, and the cost of the mold can be reduced.

Since the mold is light, it is extremely convenient to handle, and there is no need for a large crane, so equipment costs can be significantly reduced.

Since there is little heat dissipation and the mold itself is lightweight, preheating time is extremely short, and in some cases, preheating can be omitted altogether, preventing energy loss and reducing costs.

The thin metal plates used for the cover plate are extremely easy to process, and multiple pieces can be easily and firmly joined together using seams, etc., making it easy to create complex shapes. be able to. Furthermore, if foam glass or plastic foam is used as the insulating material for the mandrel, it is also extremely easy to process and can be easily formed into complex curved surfaces. Therefore, it is extremely convenient for manufacturing heat insulating covers for bent pipes.

In summary, since insulation covers made of foamed resin such as polyurethane can be easily and inexpensively manufactured, cold insulation work can be carried out easily and inexpensively on liquefied natural gas and liquefied petroleum gas storage tanks, piping, etc. Since it can quickly adapt to larger sizes, it can make a major contribution to overcoming the energy crisis.

[Brief explanation of the drawing]

Figure 1 shows an example of the insulation method used for piping for liquefied natural gas and liquefied petroleum gas, where A is a cross-sectional view, B is a front view, and Figure 2 is a mold for a conventional insulation cover. FIG. 3 is an exploded perspective view showing an apparatus for manufacturing a foamed resin heat insulating cover according to the present invention, and FIGS. 4 to 8 are views showing details of the components of the inner mold. is a front view, B is a right side view, Figure 9 is a diagram showing the outer mold, A is a front view, B is a right side view, and Figure 10 is a diagram showing the ring frame, A is a front view, B is a right side view. 11 is a perspective view showing the retaining plate, FIG. 12 is a perspective view showing the retaining metal fittings, FIG. 13 is a diagram showing the heat insulating cover manufacturing apparatus after assembly, and A is a front view. 14 is a bottom view, FIG. 14 is a diagram showing the situation in which resin is injected, A is a front view, and B is a view seen from the upper right. 1...Piping, 2...Insulation cover, 3...Meji,
11... Molding mold, 12... Female mold, 13... Male mold, 14... End plate, 21... Inner mold, 22... Flat plate, 22A... Engaging protrusion, 23... Core metal, 23A
... Engagement recess, 24 ... Reinforcement material, 25 ... Holder metal (large), 26 ... Holder metal (small), 31 ... Outer mold, 3
2...Cover plate, 33...Flange, 34...Resin injection port, 35...Protrusion, 41...Ring frame, 42
... stopper, 43 ... stop plate, 44 ... workbench, etc.

Claims (1)

[Scope of Claims] 1. A flat plate that is a part of a circular ring and has a substantially fan-shaped shape, and a roughly halved donut-shaped circle that is attached to both sides of the flat plate and that is formed by rotating the semicircle around an axis. A pair of mandrels made of heat insulating material in the shape of a part of a ring, a reinforcing material made of fabric, asphalt roofing, etc. wrapped around the surface of the mandrel, and a reinforcing material made of asphalt roofing, etc., on the outside and inside of the mandrel. an inner mold consisting of a pair of large and small clasps each having a shape of a part of a ring and attached to the flat plate with the reinforcing material in between; two concentric semicircles arranged around one axis; A pair of thin plate cover plates each having a shape of a part of a rotating substantially half-split hollow donut-shaped ring, a flange attached to the outer side of the half-split surface of the cover plate, and a flange attached to the side of the half-split surface of the cover plate; A pair of outer molds consisting of a resin injection port; four half-circular ring frames; and a plurality of fasteners are used to perform the following (a) to (d). A method for manufacturing a foamed resin heat insulating cover, characterized by molding it according to the process steps shown in the following. (a) A pair of outer molds are attached to the outside of the pair of mandrels of the inner mold, and a half-split hollow donut-shaped ring is formed by the outer surface of the mandrel and the inner surface of the cover plate. Adjust the thickness of the space forming the part to be constant, and fix the flat plate of the inner mold and the flange of the outer mold with a stopper. (b) Part of the half-split hollow donut-shaped ring. (c) Inject foamed resin from the resin injection port of the outer mold. (d) After a predetermined curing period, remove the inner mold, outer mold, and ring frame. Disassemble and take out the molded product. 2 The diameter of the ring of the flat plate constituting the inner mold, the radius of rotation of the mandrel, and the radius of rotation of the cover plate constituting the outer mold are all infinite, so the formed heat insulating cover is suitable for straight pipes. A method for manufacturing a foamed resin heat insulating cover according to claim 1, characterized in that the method comprises: 3. The shape of the mandrel constituting the inner mold is a part of a half donut-shaped ring with a central angle of approximately 90°, and the shape of the cover plate constituting the outer mold has a central angle of approximately 90°.
It is part of a 90° half-split donut-shaped ring,
The method for producing a foamed resin heat insulating cover according to claim 1, wherein the heat insulating cover to be molded is for a 90° elbow. 4. A flat plate in the shape of a substantially fan-shaped part made up of a part of a circular ring, and a part of a roughly half-donut-shaped circular ring attached to both sides of the flat plate and made by rotating a semicircle around an axis. A pair of mandrels made of a heat insulating material, a reinforcing material made of cloth wrapped around the surface of the mandrel, asphalt roofing, etc., and the reinforcing material sandwiched between the outside and inside of the mandrel. an inner mold that is attached to the flat plate and is made up of a pair of large and small clasps each shaped like a part of a circular ring; A pair of cover plates made of thin plates in the shape of a part of a split hollow donut-shaped ring, a flange plate attached to the outer side of the half-split surface of the cover plate, and a resin injection port provided in the cover plate. A pair of outer molds consisting of; four half-circular ring frames; and a plurality of fasteners, the outer mold is attached to the outside of the core of the inner mold, and the inner mold A ring frame is attached to the end face of the space forming a part of the half-split hollow donut-shaped ring formed by the inner die and the outer die, and after the inner die and the outer die are attached with fasteners, resin is poured. A manufacturing device for a foamed resin insulation cover, which is characterized by injection from an inlet and molding. 5 The diameter of the ring of the flat plate constituting the inner mold, the radius of rotation of the mandrel, and the radius of rotation of the cover plate constituting the outer mold are all infinite, so the formed heat insulating cover is suitable for straight pipes. An apparatus for manufacturing a foamed resin heat insulating cover according to claim 4, characterized in that the apparatus is an apparatus for producing a heat insulating cover made of foamed resin according to claim 4. 6. The shape of the mandrel constituting the inner mold is a part of a half donut-shaped ring with a central angle of approximately 90°, and the shape of the cover plate constituting the outer mold has a central angle of approximately 90°.
It is part of a 90° half-split donut-shaped ring,
5. The apparatus for producing a foamed resin heat insulating cover according to claim 4, wherein the heat insulating cover to be molded is for a 90° elbow.