JPH0420780A - Manufacture of heat insulator and press jig for manufacturing heat insulator - Google Patents

Abstract

PURPOSE:To manufacture a pressing jig matched to an actual center shell configuration in a short time by pressing a transfer assembly to an outer shell surface before injection of a heat insulator raw material, said transfer assembly comprising many transfer members each being movable. CONSTITUTION:A group of pin assemblies 8 is applied onto a formation part of a shelf receiving lead 4 of an inner box 3 in an outer shell 1, and a group of pins 7 is pressed from the inside of the inner box 3 until an auxiliary jig 9 properly makes contact with a flattened surface of the inner box 3. Thereupon, each pin 7 is movable axially and hence the group of the pins 7 is moved in response to the uneven surface of the outer shell 1. Hereby, the tip ends of the group of the pins 7 provide their state where they go along the uneven surface of the outer shell 1. Thus, an adhesive such as epoxy resin is injected into the back surface of a substrate 5. Once the adhesive 10 is solidified, each pin 7 is restricted in its movement because of its being fixed to the substrate by the adhesive 10. Thus, the unevenness of the surface of the outer shell 1 is transferred to the group of the pins 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for manufacturing a heat insulator by a so-called in-situ foaming method, and a holding jig therefor.

(Prior Art) For example, a heat insulating box constituting the main body of a refrigerator is generally manufactured by a foaming-in-place method in which a foamable heat insulating material is filled into an outer shell and solidified. Specifically speaking, the outer shell is composed of an outer box made of steel plate with an open front and an inner box made of plastic. Filled with foamable insulation material. The filled insulation material foams and solidifies inside the outer shell, so in order to prevent the outer shell from deforming due to foaming pressure, the outside of the outer shell is shaped along the shape of the outer shell surface. It is necessary to hold it down with a shaped holding jig. Since the outer box of a refrigerator is generally a simple rectangular parallelepiped, the outer holding jig can be configured with a flat surface, causing fewer problems. However, since the inner box has a complicated shape due to bead formation for shelf supports, etc., a holding jig specifically for the inner box must be prepared according to the shape of the inner box, which differs depending on the model. There is a need.

Conventionally, this inner box holding jig has been manufactured as follows. Design the external shape of the presser jig based on the design drawing of the inner box and draw the drawing. Thereafter, the presser jig material is machined and processed based on this design drawing to produce the presser jig. This is then cut to the actual inner box and corrected and finished by cutting it again until it exactly matches the inner box, thereby completing the presser jig.

(Problem to be Solved by the Invention) However, in the method for manufacturing the heat insulating body described above, manufacturing of the presser jig for the inner box is finally completed after repeating the tedious steps of designing, drafting, cutting, and corrective cutting. Therefore, the manufacturing period for the jig is considerably long, and the manufacturing efficiency is poor.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for manufacturing a heat insulating body that can produce a holding jig that matches the actual shape of the outer shell in a short period of time, and a holding jig for manufacturing the heat insulating body.

[Means of the Invention (Means for Solving the Problems)] The method for manufacturing a heat insulating body according to the present invention includes assembling a large number of transfer bodies in a state in which each transfer body is movable before injecting a heat insulating material raw material. By pressing the transferred aggregate onto the surface of the outer shell,
The tip of the transfer body group of the transfer body is aligned with the uneven shape of the outer shell surface, and then the transfer body is directed against the surface of the shell and inside the shell while restraining the movement of the transfer body group. The method is to fill a heat insulating material raw material (invention of claim 1).

The holding jig for this method includes a number of transfer bodies that move along the uneven shape of the surface of the outer shell by pressing them against the surface of the outer shell, and a tip that moves along the uneven shape of the outer shell surface. and restraining means for restraining the movement of each transfer member (invention of claim 2).

In this case, the transfer body can also be composed of pins (
Invention of Claim 3).

Furthermore, in configuring this type of holding jig, each bottle is provided through a through hole formed in the substrate, and each pin whose tip follows the uneven shape of the outer shell surface is attached to the substrate. The substrate may be fixed and movable relative to the outer shell, and the substrate may be moved toward the outer shell by sealing a pressure medium in an airtight chamber formed on the back side of the substrate (Claim 4). invention).

(Function) According to the invention of claim 1 or 2, by pressing a transfer assembly, which is made up of a large number of transfer bodies in a state in which each transfer body is movable, against the surface of the outer shell, the unevenness of the surface of the outer shell is reduced. Each transfer body moves according to the shape, and the tip of the transfer body group follows the uneven shape of the outer shell surface. If the movement of the transfer body group is restrained in this state, a holding jig that matches the actual outer shell shape is completed. Therefore, the heat insulating material raw material may be filled into the outer shell while the material is applied to the outer shell, and the material may be foamed.

Further, according to the third aspect of the present invention in which the transfer body is a bottle, the transfer body can follow even a fine shape.

Furthermore, according to the fourth aspect of the invention, since the pressure medium applies pressure evenly over the entire area of the substrate in the hermetic chamber, the pressing jig can evenly press the outer shell.

Furthermore, by controlling the temperature of the pressure medium, it is also possible to control the temperature of the holding jig and, by extension, the temperature of the insulation material inside the outer shell.

(Example) An example in which the present invention is applied to a manufacturing process of a heat insulating box for a refrigerator will be described below with reference to FIGS. 1 to 6.

The heat insulating box is manufactured by injecting a foamed urethane stock solution as a heat insulating material raw material into the outer shell 1, and foaming and solidifying this. As shown in Fig. 3, the outer shell 1 is composed of an outer box 2 made of steel plate and a rectangular parallelepiped shape with an open front and an inner box 3 made of plastic.The inner box 3 has shelves arranged inside the refrigerator. (not shown)
A bead 4 is formed on the shelf support for receiving the shelf.

4 to 6 show a part of a presser jig for carrying out the method of the present invention. This includes a pin assembly 8 formed by forming a large number of through holes 6 in a substrate 5 and passing a bottle 7 serving as a transfer member through each through hole 6 so as to be movable in the axial direction. This pin assembly 8 corresponds to a part of the outer shell 1 that has an irregular surface shape (in this embodiment, the shelf support of the inner box 3 is a part where the bead 4 is formed), and the other part has a flat surface shape. An auxiliary jig 9 with a flat surface corresponds to the part (the auxiliary jig 9 is shown only in FIGS. 1 and 2). In addition,
In this embodiment, the substrate 5 is made of Bakelite, the bottles 7 are made of aluminum, the pitch of the through holes 6 is 2 to 3 mm, and the outer diameter of the bottles 7 is 0.5 m+i.

Now, in order to make this pin assembly 8 function as a holding jig, do as follows. First, in the shelf support of the inner box 3 of the outer shell 1, apply the 8 groups of pins to the part where the bead 4 is formed, and insert the 7 groups of pins until the auxiliary jig 9 tightly contacts the flat surface of the inner box 3. Press box 3 from inside. At this time, since each bottle 7 is movable in the axial direction, the group of pins 7 moves according to the uneven shape of the surface of the outer shell 1, and the tip of the group of pins 7 moves along the uneven shape of the surface of the outer shell 1. state (see Figure 5).

Therefore, an adhesive 10 such as epoxy resin is poured onto the back side of the substrate 5 (see FIG. 6). When the adhesive 10 hardens, each bottle 7 is fixed to the substrate 5 with the adhesive 10 and its movement is restricted, and the uneven shape of the surface of the outer shell 1 is transferred to the group of pins 7. become. Therefore, the adhesive 10 corresponds to a restraining means for restraining the movement of the pin group 7 in the axial direction.

Thereafter, the substrate 5 to which the group of pins 7 are fixed is set in a molding device as shown in FIG. This molding device has a structure in which fixing jigs 12 and 13 are fixedly attached to the top and bottom of a rectangular frame 11, and a substrate 5 to which seven groups of pins are fixed on the left and right sides is movably attached to the inner box 3. . Each board 5 has, for example, four guide bars 14 on the side wall of the frame 11, which are movable in the left-right direction in the figure via guide bars 14, and through holes 15 formed in the frame 11 through which the guide bars 14 pass. is provided with an O-ring 16 for air sealing. In addition, the fixing jig 12,
A bellows 17 is provided between the end of the frame 13 and the end of the substrate 5, and an airtight chamber is formed outside the frame 11 by a portion of the fixing jigs 12 and 13 and the substrate 5. Air chamber 1
8 can be held airtight regardless of movement of the substrate 5.

Although not shown, an air supply pipe is connected to the air chamber 18 so that air at a predetermined temperature can be transported into the air chamber 18 as a pressure medium.

Now, in order to fill the outer shell 1 with foamed urethane, the outer shell 1 is first set in a molding device as shown in FIG. In this setting state, the substrate 5 is in a retracted relationship with respect to the outer shell 1, so even if the inner box 3 of the outer shell 1 has an uneven shape, there is no problem in setting the outer shell 1. After that, when air is sealed in the air chamber 18, the board 5 moves to expand in the left and right direction in FIG. 1, and as shown in FIG. 4 is pressed against the formed part. It is sufficient that the pressure of the enclosed air is equal to or higher than the foaming pressure of urethane foam (for example, 0.3 Kg/cs2). In this state, when the urethane foam stock solution is injected into the outer shell 1, the urethane stock solution foams, and the foaming pressure of the urethane foam is applied to the pins 7 group, the auxiliary jig 9, and the fixing jig 12.
, 13, and no deformation of the outer shell 1 occurs.

As described above, according to this embodiment, the pin assembly 8 is molded onto the required part of the outer shell 1, and the adhesive is applied in that state.
By pouring and solidifying the bottle assembly 8, the bottle assembly 8 is held and fixed in a molded state, and a holding jig that matches the actual uneven shape of the surface of the outer shell 1 can be easily manufactured. Therefore,
Compared to the conventional method of machining materials, it can be manufactured in an extremely short period of time, greatly improving productivity. In addition, the substrate 5 can be heated using air as a pressure medium.
Since the structure is such that the substrate 5 is moved and pressed against the inner box 3, the structure for moving the substrate 5 is not only simpler than that using a link mechanism, but also allows pressure to be applied evenly to the entire area of the substrate 5. Therefore, local deformation of the outer shell 1 can be reliably prevented.

Note that the present invention is not limited to the above embodiments, and the following modifications are possible.

(a) The temperature of air as a pressure medium sealed in the air chamber 18, which is an airtight chamber, is controlled in accordance with the foaming process of the urethane foam. That is, the initially sealed air is at a high temperature (for example, 4
5° C.), and this brings the temperature close to the foaming temperature of the urethane foam stock solution to promote the foaming reaction. Next, at the final stage of foaming, cooled air at a temperature lower than room temperature is introduced to replace the air in the air chamber 18. This cools the urethane foam to promote curing, thereby making it possible to shorten cycle time. In addition, when performing such temperature control, if the transfer body is made of aluminum as in this embodiment, heat conduction is fast and effective.

(ro) As a means for restraining the movement of the bottle, thermal expansion of the material may be used instead of using adhesive.

That is, for example, if both the board and the bottle are made of metal, and the entire body is heated to a high temperature during molding so that the bottle can move freely relative to the board, and the movement of the pin group is to be restrained, Cool the whole thing to room temperature. This makes it possible to restrict the movement of each bottle based on the so-called burn-off principle.

(c) As a means for restraining the movement of each transfer body of the transfer assembly, frictional force between each transfer body may be used instead of using an adhesive. That is, as shown in FIG. 7, a large number of bottles 21 are stored in a bundle in the guide tube 20, and molding is performed without applying pressure to the pin group. After forming the mold, by tightening the tightening screw 22 provided on the guide cylinder 20, pressure is applied from the pressure plate 23 to the group of pins 21, and the movement of the pins 21 is restrained using the frictional force between the pins 21. .

(iv) Although air was used as the pressure medium in the above embodiments, other gases or liquids such as oil may also be used.

(e) In the above embodiment, air sealing was performed using the bellows 19, but the invention is not limited to this, as shown in FIG.
This may be made into an airtight chamber by using a flexible bag 3o such as a rubber tube.

(f) In the above embodiment, a bottle was used as the transfer body, but as shown in FIG. 9, a large number of thin plates 31 may be stacked to form a transfer assembly.

(g) In the above embodiment, the bottle assembly 8 was used only for a part of the presser jig, and the auxiliary jig 9 was placed on the other flat part, but the entire presser jig was used as a bottle assembly. It may be configured by the body.

(h) In the above embodiment, the application is shown to be applied to the manufacturing process of a heat insulating box for a refrigerator, but the invention is not limited to this, and the door of a refrigerator may also be used.
The point is that it can be widely applied as a holding jig for the outer shell filled with insulation material raw material.

[Effects of the Invention] As described above, according to the invention of claim 1 or 2, there is an excellent effect that a presser jig that matches the actual outer shell shape can be manufactured in a short period of time.

Further, according to the third aspect of the invention, the transfer body can also follow a fine shape. Furthermore, according to the invention of claim 4, since pressure can be applied uniformly to the entire area of the substrate by the pressure medium, the outer shell can be evenly pressed with the holding jig, and the temperature of the pressure medium can be controlled. This control has the effect of making it possible to control the temperature of the presser jig and, by extension, the temperature of the heat insulating material inside the outer shell.

[Brief explanation of drawings]

Figures 1 to 6 show one embodiment of the present invention, Figure 1 is a longitudinal sectional view showing the overall structure of the holding jig, and Figure 2 is equivalent to Figure 1 showing the outer shell in a pressed state. 3 is a perspective view of the outer shell, FIG. 4 is a perspective view of the pin assembly, FIG. 5 is a longitudinal sectional view thereof, and FIG. 6 is a longitudinal sectional view thereof after molding. 7th
The figure is a perspective view of a transfer assembly showing different embodiments of the present invention;
FIG. 8 is a view corresponding to FIG. 2 showing a further different embodiment of the present invention, and FIG. 9 is a perspective view showing a further different embodiment of the present invention. In the drawing, 1 is an outer shell, 5 is a substrate, 6 is a through hole, 7゜21 is a pin (transfer body), 8 is a pin assembly (transfer assembly), 10
18 is an adhesive (restraint means), 18 is an air chamber (airtight chamber), 31 is
is a thin plate (transfer body). Applicant: Toshiba Corporation

Claims (1)

[Claims] 1. A method of manufacturing a heat insulating body by injecting a heat insulating material into the inside of an outer shell formed into a predetermined shape, and foam-filling the heat insulating material while pressing the outside of the outer shell. , before the insulating material raw material is injected, a transfer assembly in which a large number of transfer bodies are assembled in a state in which each transfer body is movable is pressed against the surface of the outer shell; Then, the transfer assembly is applied to the surface of the outer shell while restraining the movement of the transfer body group, and the heat insulating material raw material is foamed inside the outer shell. A method for producing a heat insulating body, characterized by filling the heat insulating body. 2. When producing a heat insulator by injecting a heat insulating material raw material into the inside of a shell formed into a predetermined shape and foaming and filling it, in the case where it is applied to the surface of the shell, by pressing it against the surface of the shell. It is equipped with a large number of transfer bodies that move in the axial direction along the uneven shape of the surface thereof, and a restraining means for restraining the movement of each transfer body whose tip portion follows the uneven shape of the outer shell surface. Pressing jig for manufacturing insulation. 3. The holding jig for manufacturing a heat insulator according to claim 2, wherein the transfer body is a pin. 4. Each pin is provided to pass through a through hole formed in the substrate, and each pin whose tip portion follows the uneven shape of the outer shell surface is fixed to the substrate, and the substrate is attached to the outer shell. Claims characterized in that the substrate is movably provided to the substrate and is configured to move the substrate toward the outer shell by sealing a pressure medium in an airtight chamber formed on the back side of the substrate. 3. A presser jig for manufacturing a heat insulator according to 3.