JP2003061818A - Lid of heat insulation container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the stripping of a protection cover consisting of a metal plate and the like and a resinous lid by strengthening the bond of the metal plate and insert molded resin constituting the lid of a heat insulation container and to provide the lid with excellent design, and with high insulation effect by providing a space part in a molded article. SOLUTION: The lid of the heat insulation container consists of the metal plate given laminate resin finish and is insert molded to provide the space part inside the molded article in the lid of the heat insulation container consisting of a container body and the resinous lid opening and shutting the container body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lid for a heat insulating container, and more particularly to a lid for a heat insulating container formed by insert molding a metal plate having a resin sheet previously laminated on its inner surface.

[0002]

2. Description of the Related Art Insulating containers include rice cookers, electric pots, mugs and the like. Since the lids of these heat insulating containers are often made of resin, they have problems in heat insulation, impact resistance, appearance, and the like. In order to solve these difficulties,
The applicant has already proposed the invention described in Japanese Patent Laid-Open No. 10-272068, that is, the invention in which a metal plate is directly insert-molded on the outer surface of the lid of the heat insulating container.

The present invention will be described in brief. As shown in FIG. 14, this heat insulating container comprises a container body a made of a vacuum double container made of stainless steel, and a lid b capable of opening and closing the opening of the container body a. It is composed by. The lid b is
It is composed of two members, a lid body c and a cap d, which are removable and each made of resin, and a heat insulating space e is formed therein. Further, at the center of the bottom portion of the lid body c, there is provided a valve body f that is opened when the inside of the container body a becomes a negative pressure and introduces air for releasing the negative pressure.

The cap d is made of resin and has a cylindrical top shape, and the outer peripheral surface thereof is covered with a protective cover g formed of a stainless metal plate. The lower end of the protective cover g is integrally formed with an inwardly projecting flange portion h, and is formed inward by directly insert-molding the cap d on the inner side surface of the protective cover g. The brim portion h is integrally molded in a state of being bitten into the lower end portion of the cap d. With such a structure, the protective cover g is directly integrated with the cap d, and is formed so that water does not enter between the protective cover g and the cap d. An annular line is formed at the boundary of, which also contributes to improvement in design.

However, in the conventional case, the protective cover g is made of metal and the cap d is made of resin. Therefore, even if both are integrally formed by directly insert-molding the cap d on the inner surface of the protective cover g, it is difficult to integrate the both, and even if they are integrated at the time of insert-molding,
At the time of cooling after molding, or after that, peeling is caused by vibration, temperature change, etc., resulting in a gap between the two,
There was a risk that water would enter the gap.

Further, as described above, when the protective cover g is attached by fixing the protective cover g and the cap d with the collar portion h at the lower end of the protective cover g, the cap d
It is necessary to provide a protective cover g on the entire peripheral surface of the cap, and the design is limited. For example, a protective cover g having various shapes is provided on a part of the cap d to enhance the design effect. I couldn't expect that.

[0007]

The object of the present invention is to adopt the structure described in the claims and to strengthen the connection between the metal plate forming the lid of the heat insulation container and the insert molding resin. The problem is to solve the above problem and to provide a lid having a high heat insulating effect by providing a void in the molded product.

[0008]

In order to achieve the above object, the present invention adopts the following configuration.

According to the first aspect of the present invention, in a lid of a heat-insulating container including a container body and a resin lid for opening and closing the container body, the lid is formed by inserting a metal plate processed with a laminated resin. It is formed by molding, and a void is provided inside the molded product. In the invention according to claim 2, the void is provided within the range of the metal plate in plan view.

With such a structure, as will be described later, the metal plate and the laminating resin originally have a high adhesiveness, and the resin is insert-molded on the laminated metal plate and the lid is formed. When the resin is molded, the laminating resin and the resin for insert molding are well welded and bonded, and the bonding between the metal plate and the resin for laminating is significantly different compared to the conventional example in which the resin is directly insert-molded on the metal plate. Improve to. Therefore, water does not enter between the metal plate and the insert molding resin, and it is not necessary to provide a flange portion for fixing the metal plate on the outer peripheral end portion of the metal plate as in the conventional example, and a part of the lid. The metal plate can be provided only on the. Further, by providing a closed void inside the lid, the heat insulating effect is further enhanced.

According to a third aspect of the invention, a resin coating is applied to the surface of the metal plate opposite to the laminated surface. With such a configuration, during insert molding,
When the metal plate is put into the mold, the coating resin is interposed between the metal plate and the mold, and the adhesion between the metal plate and the mold is enhanced.

In the invention according to claim 4, the resin of the same material is used for the laminating and molding members, and the melting temperature of the laminating resin is lower than that of the molding resin. With this configuration, since the laminating resin and the molding resin are the same at the time of insert molding, the weld bondability is remarkably improved as compared with that between different resins. Also, during insert molding,
When the melted insert molding resin is injected into the mold, the laminating resin melts earlier because the laminating resin has a lower melting temperature than the molding resin.
Immediately welds and integrates with insert molding resin.

In the invention according to claim 5, the melting temperature of the coating resin is higher than that of the laminating resin. With this configuration, when the insert molding resin melted is injected into the mold during insert molding, even if the laminating resin is immediately welded and integrated with the insert molding resin, the coating resin remains Since it does not melt, the coating resin melts during insert molding, and a gap is created between the metal plate and the mold, so that the metal plate does not shift within the mold.

In the invention according to claim 6, a non-circular hole is provided in the metal plate, and an end portion of the hole is bent, and the metal plate is fixed using the hole. With such a configuration, at the time of insert molding, the metal plate can be easily fixed in the mold by utilizing the non-circular hole, and by the bending process provided at the end of the hole, The bond between the metal plate and the insert molding resin is further strengthened.

In the invention according to claim 7, in order to prepare for the temporal change after the molding of the molded product, the molded product is bent in a direction opposite to the deforming direction. In the invention according to claim 8, a correction jig is used. The structure to bend and bend. With such a configuration, the difference in shrinkage rate between the metal plate and the resin due to the temperature change does not cause the resin portion to warp, and the predetermined molded product cannot be molded. This warping means may be one in which the size inside the mold is widened in advance in an amount corresponding to the amount of deformation, and it may be manually or automatically changed depending on the shape and size of the molded product. A straightening jig may be used.

According to a ninth aspect of the present invention, the straightening by the straightening jig is performed for a predetermined time, and then heat treatment is performed for a predetermined time at a temperature lower than the molding temperature. That is, according to the structure of claim 8, it is possible to prevent the generation of defective products due to warpage of the molded product, but forcibly bending the molded product means that internal stress remains in the molded product and this internal stress Tries to restore the molded product. Therefore, internal stress can be removed by subjecting the molded product to an annealing treatment, which is a kind of annealing, and a molded product having a predetermined shape can be obtained.

According to a tenth aspect of the invention, the cavity is formed by gas injection. With such a configuration, it is possible to more easily form the void portion that is the closed space having the predetermined shape.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a lid of a heat insulating container, and as the heat insulating container, there are various things such as a rice cooker, an electric pot, and a mug bottle. In the following, a rice cooker will be taken as an example. Explain.

FIG. 1 is a sectional view showing the rice cooker to which the present invention is applied. As shown in FIG. 1, the rice cooker is roughly divided into a container body 1 capable of accommodating an inner pot 6, and a lid 40 closing an upper opening of the container body 1. The container body 1 is made of resin and includes an outer case 2, an inner case 3 and a shoulder body 4. A bottom coil 5a and a corner coil 5b, which are work coils, are provided at the bottom of the inner case 3 and at the corners from the bottom to the side surface, respectively. Current control is performed. Also, inner case 3
A heat-retaining heater 5c attached by an adhesive tape or the like is disposed above the side surface of the outer peripheral surface, and similarly the energization is controlled by the control device during heat retention. Reference numeral 5d is a heat insulating material provided on the outer periphery of the heat retaining heater 5c in order to enhance the heat retaining efficiency.

The coils 5a and 5b are mounted on the coil base 7, and the central portion of the coil base 7 is
A center sensor 8 including a reed switch for detecting the set state of the inner pot 6 and a thermistor for detecting the temperature of the inner pot 6.
Is provided.

The center sensor 8 has a built-in spring. When the inner pot 6 is not set, the tip of the center sensor 8 projects above the bottom of the inner case 3, and when the inner pot 6 is set, A safety device is formed which is pushed down while being in contact with the outer surface of the bottom of the inner pot 6 to be activated by the reed switch, but which does not operate unless the inner pot 6 is set.

The inner pot 6 has the work coils 5a and 5a.
It is formed of an iron-based metal such as stainless steel capable of self-heating due to an eddy current induced inside by b. The shape is substantially W-shaped in cross section, which is almost the same as the inner case 3. By setting the inner pot 6 in the inner case 3, the center sensor 8 is turned on and the coils 5a, 5b are energized. And the inner pot 6 is heated by the Joule heat caused by the eddy current.
Is heated and the contents such as rice and rice put inside are efficiently cooked.

The shoulder body 4 is integrated with the container body 1 by a forceful fitting means, a shoulder heater 4a for heating the heat dissipation plate 13 is attached to the inner upper portion thereof, and a handle 9 is attached to the side wall portion thereof. To be A display device 10 including various switches and a display panel is arranged on the front side of the container body 1. In addition, 10 a is a lock member for locking the lid 40 to the container body 1.

The lid 40 comprises an outer lid 11, a vacuum heat insulating structure 12 and a heat radiating plate 13 forming an inner lid. The outer lid 11 is an integrally molded member made of synthetic resin, the details of which will be described later, but a cylindrical body 15 having a circular opening 14 serving as a steam passage is integrally formed in the central portion thereof. At the bottom of the tubular body 15, the first hollow body 16
Are integrally connected by means such as a force fit or an adhesive agent, and a second hollow body 17 is screwed onto the outer periphery of the first hollow body 16 so that both hollow bodies 16 and 17 can be screwed together. The vacuum heat insulating structure 12 described later is fixed by screwing.

The vacuum heat insulating structure 12 includes an outer member 12a.
And the inner and outer peripheral ends of the inner member 12b are welded together, and both members 1
2a made of stainless steel with a vacuum inside 2a and 12b
It is composed of a heavy structure and is provided so as to cover the upper opening of the inner pot 6 as a whole, and prevents heat from escaping from the upper opening of the inner pot 6. Further, the vacuum heat insulating structure 12 has a circular opening formed in the center thereof, and the second hollow body 17 can be locked at the opening end.
The vacuum heat insulating structure 12 is held by the lid 40 by screwing the hollow body 17 of the above into the first hollow body 16.

The heat radiating plate 13 provided inside the vacuum heat insulating structure 12 is fitted with a rivet at the center of the heat radiating plate 13.
8 is attached, the fitting cylinder 18 can be fitted into the first hollow body 16 freely. Further, when the lid is closed, its outer peripheral end contacts the upper surface of the shoulder heater 4a provided on the shoulder body 4, is heated by the shoulder heater 4a, and efficiently cooks rice and keeps heat from the upper portion of the inner pot 6 as well. .

Furthermore, a pressure adjusting unit 19 is detachably attached to the cylindrical body 15 at the center of the lid 40. The pressure adjusting unit 19 includes a valve body 20 arranged in the unit 19 and a pressure adjusting cap 2 covering the upper portion of the unit 19.
1, the valve body 20 is pushed up when the steam pressure in the inner pot 6 becomes a predetermined value or more and discharges excess steam to the outside from a plurality of steam discharge ports provided in the pressure regulating cap 21.

A hinge 2 is provided at the rear end of the shoulder body 4 of the container body 1.
The lid 40 is rotatably pivoted by the arc 2 and the upper opening of the container body 1 is opened by pivoting the lid 40 upward about the pivot point, and the lid 4 is opened from this opened state.
The upper opening is closed by rotating 0 downwards.
That is, in the hinge cover 23 fixed to the rear end of the shoulder body 4,
Connect the upper arm cover 24 and the lower arm cover 25 to the pivot 2
6 is pivotally supported in an arc rotatable manner, and a leaf spring 27 is interposed between the upper arm cover 24 and the lower arm cover 25. The leaf spring 27 always applies a force in the opening direction to the lid 40, but is closed by the lock member 10a when the lid is closed. Then, when the lock of the locking member 10a is released, the lid 40 is opened, and the lid 40 can be removed by pulling it upward with a hand in an opened state (upright state). Allows washing in whole.

The outer lid 11 will be described.
Reference numeral 1 denotes an integrally molded synthetic resin member, which can be molded by an injection molding machine, for example, injection injection molding, injection needle injection molding, or other suitable injection molding method. . At the same time, a ring-shaped void 28 is formed by gas injection molding on the outer peripheral portion of the outer lid 11 at a position that covers at least the vicinity of the outer peripheral portion of the inner pot 6 in the closed state.

The gas injection molding method is also called a gas-assisted injection molding method. In injection molding of a thermoplastic resin, high-pressure nitrogen gas is injected into the mold cavity following injection of the resin, whereby a general method is used. This is a molding method in which voids are formed in a molded product by operating a pressure-holding step of injection molding, and at the same time, warpage, sink marks and the like in the molded product are prevented.

Also in the present invention, such an injection molding machine is used to form a void in the lid. Specifically, when the molten resin enters the mold about 2/3, the cavity is formed. Gas injection port 2 with a smaller diameter than the needle-shaped nozzle provided
A high-pressure nitrogen gas is injected via 9 to form a substantially ring-shaped void 28, and after the formation, the gas inlet 29 is closed by welding to make the inside a closed space. Although polypropylene (PP) having a melting point of 220 to 230 ° C. is used as the molding resin, any resin may be used as long as it is the same as the laminating resin described later. Its form is shown in FIG. 1 in cross section and in FIG. 2 in its entire plane.

Reference numeral 30 denotes a metal plate or the like integrally formed on the upper surface of the outer lid 11 of the rice cooker according to the present invention. The metal plate 30 and the like are a metal plate 31 made of stainless steel (SUS304), The sheet resin 32 is laminated on one side of the metal plate 31. A partially enlarged cross section of the metal plate 30 is shown in FIG. That is, on a metal plate (iron, aluminum, stainless steel, etc.) 31, polyethylene (PE), polyester (PET), polypropylene (PP), nylon (P
A film resin 32 such as A) is laminated with no adhesive or solvent, and the molding method is, for example, Japanese Patent Publication No.
As disclosed in Japanese Unexamined Patent Publication No. -100350, a product is already sold by the applicant, Laminate Industry Co., Ltd., and the present invention can also use such a product.

The metal plate 31 of the present invention has a thickness of 0.
3 mm to 1.0 mm is used, and the laminating resin 32 has a thickness of 30 μm to 150 μm.
The micron used has a melting point of 110 to 150 ° C. By thus lowering the melting temperature (110 to 150 ° C.), which is the melting temperature of the laminating resin 32, to that of the molding resin (220 to 230 ° C.) for insert molding, the resin is melted in the mold during insert molding. When the insert molding resin is injected, the laminating resin melts quickly and is immediately fused and integrated with the insert molding resin. In addition, when laminating the laminating resin 32 on the metal plate 31, if the metal plate 31 is subjected to a concavo-convex process, the adhesion between the two may be further improved.

FIG. 2 shows the entire shape of the metal plate 30 etc. integrally insert-molded on the outer lid 11 of the rice cooker. The outline of the processing steps for molding the lid is as follows. A metal plate 30 in which a laminating resin 32 is attached to the metal plate 31 is prepared. A metal plate or the like 30 which is integrally formed with the lid is formed by a pressing machine. A metal plate or the like 30 is placed in a mold and insert-molded with an insert-molding resin. Take out the molded product from the mold and correct it to eliminate warpage.

Description will be given according to each step. "Metal plate, etc. 3
As described above, as shown in FIG. 5, the metal plate 30 is made of stainless steel (SUS30).
Since the metal plate 31 of 4) and the sheet resin 32 laminated on one surface of the metal plate 31 are used, and such a product is already on the market, such a product can be used.

Regarding the "molding process by the press machine", those already processed are shown in FIG. 3 and FIG. 3A shows the same thing, and FIG. 3A is a plan view.
4B is a front view, FIG. 4C is a side view, and FIG.
Shows a side sectional view. First, the shape of the metal plate 30 will be described. The metal plate 30 has a substantially triangular shape as shown in FIG. 3 (A), and has a main body 31a and a recess 31.
c, and the whole is curved in a bowl shape around the recess 31c, and forms the outer surface of the lid 40 after being integrated with the outer lid 11 by insert molding. Body 31
The outer peripheral end 31b of a is subjected to a bending process such as having a spherical surface R toward the back surface to improve the bite with the insert molding resin during insert molding.

The recess 31c has a ring-shaped inclined portion 31d inclined toward the center and a horizontal bottom 31e formed at the center thereof, and the horizontal bottom 31e has a rectangular opening 31f. Is formed, and a bent portion 31g having a spherical surface R or the like is formed at the entire peripheral end of the rectangular opening 31f by bending in the back surface direction. The square opening 31f is used as a hole for fixing the metal plate 30 or the like in the mold, and the bent portion 31f thereof is used.
g improves the bite with the insert molding resin during insert molding.

These shapes are formed by a pressing machine once or by several steps of pressing.
The shape of the metal plate or the like 30 is not limited to the above-mentioned one, but may be variously changed according to the shape of the lid or design requirements. The bent portion 31g having the spherical surface R may be subjected to edge treatment such as curling.

The "insert molding process" will be described. FIG. 2 shows a state in which the metal plate 30 is attached to the outer lid 11 of the rice cooker by insert molding. As shown in the figure, the metal plate 30 is provided on a part of the outer lid 11. The center of the rectangular opening 31f provided in the horizontal bottom 31e of the metal plate 30 is provided substantially in the center of the outer lid 11, and the circular opening 14 into which the pressure adjusting unit 19 is inserted.
It is arranged to be the center of. Therefore, after the pressure regulating unit 19 covered with the pressure regulating cap 21 is inserted into the circular opening 14 of FIG. 2, the bottom portion of the pressure regulating unit 19 abuts the horizontal bottom portion 31e of the recess 31c, and FIG.
As shown in FIG. 5, the pressure adjusting cap 21 is inserted and arranged so as to cover almost the entire recess 31c. Thus, when the metal plate or the like 30 of the present invention is applied to the rice cooker or the outer lid 11 of the electric pot, the rectangular opening 31f used for fixing during insert molding can be used as the steam passage. .

Further, the front end 31h of the metal plate or the like 30 is retracted by about 2 mm from the front end of the outer lid 11 in order to prevent the die from hitting the metal plate or the like 30 during insert molding. In addition, as shown in FIG. 2, by providing the void portion 28 within the range of the metal plate 30 or the like in a plan view, the heat insulating effect can be enhanced in combination with the arrangement of the metal plate 30 or the like.

By the way, at the time of insert molding, some fixing means is required in order to arrange the metal plate 30 in the mold beforehand.
A non-circular hole is provided in the, and this hole is used for fixing the metal plate 30 and the like, and after the molding, the hole is used as a vapor passage for the product.

Explaining the insert molding process,
FIG. 6 is a cross-sectional view showing a state in which the metal plate 30 is attached to the mold. The mold 33 has a recess 33a for outer lid and a recess 33b for metal plate or the like on one wall surface thereof, and the recess 33b for metal plate or the like is almost the same as the square opening 31f into which the square opening 31f can be inserted. A protrusion 33c having the same shape is formed, and when the metal plate 30 is fixed in the mold 33, the rectangular opening 31f is inserted into the protrusion 33c. Further, a vacuum evacuation passage 33d communicates with the recess 33b for the metal plate or the like, and the rectangular opening 31f of the metal plate 30 or the like is inserted into the protrusion 33c, and the surface of the metal plate 30 (for laminating) is inserted. The air in the space formed between the wall surface of the surface opposite to the resin) and the recess 33b for metal plate or the like is evacuated through the vacuum evacuation passage 33d. The surface of the metal plate or the like 30 is adsorbed on the wall surface, and as a result, the metal plate or the like 30 is firmly fixed to the recess 33b for the metal plate or the like. In the figure, the outer lid recess 33a and the metal plate etc. recess 33b are shown.
Although it is illustrated that there is a stepped portion in the and, it is needless to say that the outer lid 11 and the metal plate 30 are flush with each other without the stepped portion.

However, as described above, when the surface of the metal plate 30 is adsorbed on the wall surface of the recess 33b for metal plate etc. and the metal plate 30 is firmly fixed to the recess 33b for metal plate etc., the metal plate etc. Since the metal mold 30 and the metal mold 33 are made of metal, and the adhesion between them is not always good when vacuumed, the means shown in FIG. 7 can be adopted.

That is, the resin 32 for laminating the metal plate 31.
The resin 32a is coated on the surface on the side opposite to (the surface closely contacting the wall surface of the recess 33b for a metal plate or the like).
The coating resin 32a has a melting point of about 170 ° C. (higher than 110 ° C., which is the melting point of the laminating resin 32) and a clear lacquer varnish having a thickness of 5 to 10 microns or an epoxy resin sheet applied or adhered. By doing so, the contact between the metal plate 30 or the like and the recess 33b for the metal plate or the like is strengthened, and as a result, both can be fixed more firmly. In this case, by setting the melting temperature of the coating resin 32a higher than that of the laminating resin 32, the coating resin does not melt during insert molding, so the coating resin 32a melts during insert molding. ,
A gap is formed between the metal plate 30 or the like and the mold 33, and the two are prevented from being displaced.

After fixing the metal plate 30 in the mold 33,
A molding resin space is formed inside the mold by attaching molds on the other side (not shown), and the molding resin 11 of the same material as the laminating resin 32 is injected into the space, for example, by injection injection molding. , Injection needle injection molding or other suitable injection molding method. Then, the lid 4 formed by integrally and firmly bonding the metal plate 31 and the molding resin 11 via the laminating resin 32.
Mold 0.

When the molded product processed as described above is taken out of the mold, the molded product tends to shrink due to the temperature drop. However, the molded product is an integrally molded product of a metal plate and a resin, and the two naturally have different shrinkage rates. FIG. 8 schematically shows a deformed state of the molded product due to a temperature drop after molding. That is, the cross section of the lid of the heat insulating container such as the rice cooker or the electric pot has a shape curved downward as shown in FIG. 8, and the metal plate 30 is integrally insert-molded on the upper surface thereof. . When such an overall shape and arrangement of each member have the relationship shown in the figure when cooled, the molded product is deformed in the direction indicated by the white arrow in the figure due to the difference in shrinkage rate of both. To do. In other words, warpage will occur. If such warpage occurs, it cannot be used as a product, so after insert molding (correction before insert molding will be described later).
A process to correct the warp is required. In the figure, reference numeral 32 indicates a laminating resin, but after insert molding, it is integrated with the insert molding resin so that the boundary between them disappears and it is impossible to distinguish between them, but it is shown by a wavy line for convenience.

The "correction process" will be described. Figure 9
Shows an example of a straightening device. The straightening device 35 includes the cradle 3
6 and a pressing device 37 and the like. On the pedestal 36, a receiving plate 36a for mounting the molded product, a positioning plate 36b for positioning the molded product, a pressing device 37, etc. are placed. The pedestal 36 is a pedestal on which the left and right ends of the molded product are placed, and two rectangular members elongated in the front-rear direction are arranged on the left and right sides. The positioning plate 36b is a rectangular block base. The positioning plate 36b having this shape is particularly suitable for a lid of a rice cooker. That is, the lid 4 of the rice cooker
No. 0 is removable, and a recess 11a for receiving a hinge is formed in the rear portion of the lid 40, and the positioning plate 36b has the shape of the recess 11a. Of course, in the shape of the molded product, this positioning plate 36
It goes without saying that the shape of b is different.

The pressing device 37 has a pressing mechanism 37a such as hydraulic and electric mechanism (not shown).
7a has a pressing rod 37b, a pressing piston 37c attached to the tip of the pressing rod 37b, and the like, and moves the pressing rod 37b and the pressing piston 37c up and down in the direction of the double-headed arrow.

Reference numeral 40 denotes a lid as a molded product which has already been described, and shows a state in which the lid 40 is placed on the pedestal 36. That is, the concave portion 11a formed at the rear portion is positioned by being placed on the positioning plate 36b, and the left and right ends thereof are placed on the receiving plate 36a. After that, the pressing piston 37c connected to the pressing device 37 is brought into contact with the horizontal bottom portion 31e formed on the metal plate 30 or the like, and the pressing piston 37c is pushed down in the direction of the hollow single arrow to open the lid 40. Will be pressed against.
The pressing device 37 may be manual or automatic. In the automatic device, as described above, the pressing mechanism 37a such as the hydraulic pressure and the electric mechanism causes the pressing piston 37c to move a predetermined amount by a predetermined force via the pressing rod 37b. It will be pressed.

When the molded product is a rice cooker, it is deformed in a direction opposite to the deformation direction due to the temperature drop by pressing it with a predetermined force for about 6 to 7 mm, which is also for about 7 to 10 minutes. In this case, if the pushing-down distance is known in advance, a stopper having a height such that the pushing-down amount can be provided between the receiving plates 36a.

Incidentally, forcibly bending the molded product means that internal stress remains in the molded product, and this internal stress tends to restore the molded product to its original state. Therefore, the internal stress can be removed by subjecting the molded product to an annealing treatment which is a kind of annealing. This annealing process is performed, for example,
It is performed by heating at a temperature of 100 to 120 ° C. for about 30 seconds.

The above-mentioned straightening process is an indispensable process when deformation occurs as a result of temperature change, but there is also a molding method in which this process may be omitted.

That is, a molded product is produced in a shape in which the amount of deformation due to a temperature drop after molding is assumed in advance. For that purpose, a mold having a shape that is wider than the shape of the finished product is prepared in advance, and insert molding is performed using the mold to make a molded product. Although the molded product is deformed by the temperature drop after molding, the molded product is preliminarily expanded by the amount of the deformation, so that the molded product has a predetermined shape after the deformation.

In the present invention, as shown in FIG. 8, since the metal plate 30 is integrally formed on the upper convex portion of the outer lid 11, the deformation after the temperature drop occurs in the direction of the white arrow.
As a means for preventing the deformation after the temperature drop, as shown in FIG. 10, the same metal plate or the like 30 is integrally formed on the upper convex surface portion and the lower concave surface portion on the opposite side of the outer lid 11 in the figure, so that Can be prevented from being deformed. In this case, the deformation in the direction opposite to the direction of the white arrow in FIG.
In, the direction of the white arrow occurs, but the amount of deformation from the shape of the lid in that direction is small.

On the contrary, when the lid of the heat insulating container for heating the contents such as the rice cooker is formed by adopting this structure, the lid is also heated at the same time when the contents are heated. Since this causes expansion deformation in the direction of, and deforms so as to eliminate the gap between the container body and the lid, such a form is preferable if the deformation amount is set to a predetermined amount in advance.

Of course, it is also possible to integrally form a metal plate or the like 30 on both the upper convex surface portion of the outer lid 11 and the lower concave surface portion on the opposite side. In this case, the difference in shrinkage factor cancels each other and almost no deformation occurs. It is preferable because it does not occur. An example thereof is shown in FIG. Although FIG. 11 also shows the lid 40 of the rice cooker, it may of course be the lid of another container. That is, the outer lid 11 is provided with the void portion 28 by gas injection, and the metal plate 3 is provided on the upper convex portion and the lower concave portion of the outer lid 11.
A metal plate 30 made of 1 and a laminating resin 32 is integrally molded.

12 and 13 show an example in which the present invention is applied to a lid of a mug bottle, and FIG.
3 shows a partially enlarged sectional view of the lid. The mug bottle is a container that is easy to carry and is widely used, including a container body 1 having a wide mouth and a lid 40 screwed onto the container body 1. The container body 1 is a heat insulating container composed of a stainless steel vacuum double container similar to that of the conventional example of FIG. 14, and an upper outer end portion thereof has a female screw (not shown) similar to that of the conventional example. Has been done.

The lid 40 is composed of a lid 11 and a metal plate 30 and the like.
A male screw 38 that engages with a female screw of the container body 1 is provided,
In addition, a ring-shaped void 28 is formed on the upper inner peripheral surface. The metal plate 30 is composed of a metal plate 31 and a laminating resin 32. The materials and processing steps for the metal plate 30 and the lid 11 are the same as those described in the embodiment of the rice cooker, and thus the repetitive description thereof will be omitted. By thus providing the stainless cover on the surface of the lid 40, various designs of designs can be applied to the stainless cover, so that the designability can be improved and the luxury can be further enhanced.

The invention of the present application is not limited to the configuration of the above-mentioned embodiment, and it goes without saying that the design can be changed as appropriate without departing from the gist of the invention.

[0060]

According to the first and second aspects of the present invention, the lid of the heat insulating container is formed by insert molding a metal plate processed with a laminate resin to provide a void portion inside the molded article, or the void portion thereof. By providing in the range of the metal plate in a plan view, the connection between the metal plate and the laminating resin is
The laminating resin and the insert molding resin are fusion-bonded to each other, which is a marked improvement over the conventional example in which the resin is simply insert-molded directly on the metal plate. Therefore, the molded product of the resin is reinforced, the impact resistance is improved, and the chemical resistance is improved. Further, since the metal plate and the resin for insert molding are closely bonded to each other over the whole, the lid can be washed completely, and a collar for fixing the metal plate to the outer peripheral end of the metal plate as in the conventional example. Since it is not necessary to provide a part, the production cost can be reduced. Further, the metal plate can be provided in a free shape only on a part of the lid, and the design can be improved. Furthermore, by providing a closed space inside the lid, the heat insulating effect can be enhanced in combination with the arrangement of the metal plate.

According to the third aspect of the present invention, resin coating is applied to the surface of the metal plate opposite to the laminated surface, so that when the metal plate is inserted into the mold during insert molding, it is placed between the metal plate and the mold. Since the coating resin can intervene and the adhesion between the metal plate and the mold can be improved, the metal plate will not be displaced during insert molding, and the precision of the molded product can be improved.

In the invention according to claim 4, the resin of the same material is used for the laminating and molding members, and the melting temperature of the laminating resin is set lower than that of the molding resin, so that the insert molding is performed. Since the laminating resin and the molding resin are the same, the weld bondability can be significantly improved as compared with that between different resins. Also, when the melted insert molding resin is injected into the mold during insert molding, the laminating resin has a lower melting temperature than the molding resin, so it is possible to melt the laminating resin earlier. Therefore, the metal plate and the resin for insert molding can be tightly bonded to each other immediately and reliably.

In the invention according to claim 5, by making the melting temperature of the coating resin higher than that of the laminating resin, when the molten insert molding resin is injected into the mold during insert molding, The laminating resin is immediately welded and integrated with the insert molding resin, but the coating resin does not melt, so
The coating resin melts during insert molding, and a gap is created between the metal plate and the mold, so that the metal plate does not shift in the mold and the precision of the molded product can be further improved.

In the invention according to claim 6, a non-circular hole is provided in the metal plate, and the end portion of the hole is bent,
By fixing the metal plate using this hole, the metal plate can be easily and surely fixed in the mold during insert molding, so that the production cost can be reduced. Further, the bending process provided at the ends of the holes can strengthen the bond between the insert-molded metal plate and the insert-molding resin, so that the tight bond between the two can be further enhanced.

According to the seventh and eighth aspects of the invention, the metal product is warped in a direction opposite to the direction of deformation, or is warped by using a straightening jig, in order to prepare for a change with time after molding of the molded product. Even if a warp occurs in the resin portion due to the difference in shrinkage rate between the plate and the resin due to temperature change, the warp can be easily removed, and the yield of the molded product can be increased.

In the invention according to claim 9, after the straightening is performed by the straightening jig for a predetermined time, the warp of the molded product is forcibly removed by performing the heat treatment at a temperature lower than the molding temperature for a predetermined time. Since the internal stress that remains in the molded product later can be effectively removed, the accuracy of the molded product can be increased and the yield of the molded product can be further increased.

According to the tenth aspect of the present invention, by forming the void portion by gas injection, it is possible to easily and reliably form the void portion, which is a closed space having a predetermined shape, and in combination with the arrangement of the metal plate. The heat insulation effect can be enhanced.

[Brief description of drawings]

FIG. 1 is an overall cross-sectional view of a heat insulating container (rice cooker) of the present invention.

FIG. 2 is a plan view of the lid of the heat insulating container of the present invention.

3A is a plan view of a metal plate or the like of the present invention, and FIG. 3B is a front view of the metal plate or the like of the present invention.

4 (C) is a side view of the metal plate or the like viewed from the line AA of FIG. 3 (A), and FIG. 4 (D) is a side of the metal plate or the like viewed from the line BB of FIG. 3 (A). Sectional view.

FIG. 5 is a partially enlarged sectional view of a metal plate or the like of the present invention.

FIG. 6 is a cross-sectional view showing a state in which a metal plate or the like of the present invention is attached to a mold.

FIG. 7 is another partially enlarged sectional view of the metal plate or the like of the present invention.

FIG. 8 is a sectional view schematically showing the warp of the lid of the heat insulating container of the present invention.

FIG. 9 is a perspective view schematically showing a correction jig for correcting the warp of the lid of the heat insulating container of the present invention.

FIG. 10 is a cross-sectional view schematically showing a state where the warp of the lid of the heat insulating container of the present invention is corrected.

FIG. 11 is another sectional view schematically showing a state where the warp of the lid of the heat insulating container of the present invention is corrected.

FIG. 12 is an overall sectional view of a heat insulating container (mug bottle) of the present invention.

FIG. 13 is a cross-sectional view of the lid of the heat insulating container (mug bottle) of the present invention.

FIG. 14 is a cross-sectional view of a lid of a conventional heat insulating container.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Container body 2 ... Outer case 3 ... Inner case 4 ... Shoulder body 6 ... Inner pot 7 ... Coil stand 8 ... Center sensor 9 ... Handle 10 ... Display device 11 ... Outer lid 12 ... Vacuum heat insulating structure 13 ... Heat sink 14 ... Circular opening 15 ... Cylindrical body 16 ... 1st hollow body 17 ... 2nd hollow body 18 ... Fitting cylinder 19 ... Pressure regulation unit 21 ... Pressure regulation cap 22 ... Hinge 23 ... Hinge cover 24 ... Upper arm cover 25 ... Lower arm cover
26 ... Axis 27 ... Leaf spring 28 ... Void 29 ... Gas injection port 30 ... Metal plate 31 ... Metal plate 32 ... Laminating resin 33 ... Mold 35 ... Straightening device 36 ... Cradle 37 ... Pressing device 38 ... Male screw 40 ... Lid 4a ... Shoulder heater 5a ... Bottom coil 5b ... Corner coil 5c ... Heat insulation heater 10a ... Lock member 11a ...
Recess 12a ... Outer member 12b ... Inner member 31a ...
Body part 31b ... Outer peripheral end part 31c ... Recessed part 31d ...
Inclined part 31e ... Horizontal bottom part 31f ... Rectangular opening part 31g ...
Processing part 31h ... Front end 32a ... Coating resin 3
3a ... Outer lid recess 33b ... Metal plate etc. recess 33c ... Projection 33d ...
Vacuum evacuation passage 36a ... Receiving plate 36b ... Positioning plate 37a ...
Pressing mechanism 37b ... Pressing rod 37c ... Pressing piston

Claims (10)

[Claims] 1. A lid of a heat insulating container comprising a container body and a resin lid for opening and closing the container body, wherein the lid is
A lid for a heat insulating container, characterized in that a metal plate treated with a laminated resin is insert-molded, and a void is provided inside the molded product. 2. The lid of the heat insulating container according to claim 1, wherein the void portion is provided within a range of the metal plate in a plan view. 3. The lid for a heat insulating container according to claim 1, wherein the surface of the metal plate opposite to the laminated surface is coated with a resin. 4. The heat insulation according to claim 1, wherein a resin made of the same material is used as the laminating and molding members, and the melting temperature of the laminating resin is lower than that of the molding resin. Container lid. 5. The melting temperature of the coating resin is
The lid of the heat insulating container according to claim 3, wherein the lid is higher than that of the laminating resin. 6. The metal plate is provided with a non-circular hole, the end portion of the hole is bent, and the metal plate is fixed using the hole. The lid of the heat insulating container according to 5. 7. Preparing for a change with time after molding of the molded article,
The lid for the heat insulating container according to claim 1, wherein the lid is bent in a direction opposite to the direction of deformation. 8. The lid of the heat insulating container according to claim 7, which is bent by using a straightening jig. 9. The lid of the heat insulating container according to claim 8, wherein the straightening by the straightening jig is performed for a predetermined time and then a heat treatment is performed at a temperature lower than a molding temperature for a predetermined time. 10. The lid for a heat insulating container according to claim 1, wherein the void is formed by gas injection.