JP2007052943A - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating cooker which can be used without anxiety wherein coming-off or cracks of a top plate does not occur. <P>SOLUTION: This induction heating cooker is provided with the top plate 2 located in an upper part of a product body 1, made of crystallized glass and covering the upper part of the product body 1 and a case made stainless steel or a resin fixing the periphery of the top plate 2. The case and the top plate 2 are bonded using a silicon-base adhesive, and the stress applied to a top plate 2 is relaxed be changing bonding strength according to a bonding place. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bonding configuration of a top plate of an induction heating cooker.

Conventionally, a box-shaped product body uses a top plate made of ceramic with a flat surface for ease of use, care, and design, and covers the periphery with a metal top frame or under frame. There is an induction heating cooker with a sealed configuration (see, for example, Patent Document 1). Specifically, it is an adhesive configuration in which a top plate made of ceramic on which a pan or the like is placed, and a metal top frame such as stainless steel and an under frame are joined by an adhesive, which is located at the top of the product body. In addition, in order to ensure the quality of the seal structure during bonding, the top frame and the under frame are thoroughly degreased and washed, and then a liquid adhesive is injected between the top plate and the top frame and the under frame to perform heat treatment under pressure. And integrated.
JP-A-11-239521

  However, in the above-described conventional configuration in which stainless steel or plated steel is used for the top frame and the under frame, machine oil used when these materials are processed into a predetermined shape is completely removed by degreasing cleaning. On the contrary, the detergent used as a detergent has a problem that it adheres as dirt and inhibits adhesion.

  For this reason, when bonding the top frame or the under frame to the top plate, it is necessary to pay close attention to suppress the stress and to ensure a certain level of bonding strength.

  In general, as a standard for judging whether or not the adhesive strength can be secured above a certain level, there is a method for confirming that the adhesive does not peel off at the boundary and the adhesive coheses and breaks.

  In addition, the induction heating cooker is used to place cooking utensils such as pots and pans with water and food on the top plate, so that the thermistor that detects the temperature on the back of the top plate pushes from below or adheres to the top plate. Since the parts to be bonded with the adhesive are bonded in a state of warping each other, the top plate is subjected to a very large load, which can lead to cracking of the top plate when the top plate is firmly bonded and fixed. There was sex.

  The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an induction heating cooker having an adhesive structure that suppresses stress on the top plate and has excellent adhesive strength.

  In order to solve the above-described conventional problems, an induction heating cooker according to the present invention fixes a top plate made of crystallized glass, which is located at the top of a product body and covers the top of the product body, and the periphery of the top plate. A case made of stainless steel or resin is provided, and the case and the top plate are bonded using a silicon-based adhesive, and the adhesive strength is changed depending on the bonding location to relieve the stress applied to the top plate.

  As a result, the top plate can be firmly bonded or fixed at the strongly bonded portion, and the stress generated on the top plate at the relatively weak bonding strength can be released.

  In the present invention, a silicon adhesive is used to bond and fix the case and the top plate, and by making a difference in the bonding strength at the bonding location, the stress generated on the top plate is firmly bonded or fixed. Can be released, and an induction heating cooker with reduced risk of dislodging or cracking the top plate can be realized.

  1st invention is located in the upper part of a product main body, The top plate which consists of crystallized glass which covers the upper part of a product main body, and the case which consists of stainless steel or resin which fixes the periphery of the said top plate, The said case, The top plate is bonded to the top plate using a silicon-based adhesive, and the top plate is strongly bonded by changing the bonding strength depending on the bonding position to reduce the stress applied to the top plate. Can be firmly bonded or fixed, and the stress generated on the top plate at a relatively weak bonding strength can be alleviated by slight movement or displacement of the bonding surface.

  According to the second aspect of the present invention, a strongly bonded portion is balanced by using an induction heating cooker having a substantially quadrangular shape and having a set of two opposing sides improved in adhesive strength over the other two opposing sides. In addition to being able to form well, it is easy for the operator to remember the position, so it can be efficiently formed without wondering where to bond strongly.

  The third aspect of the invention provides an induction heating cooker in which the adhesive strength of the adhesive portion in the vicinity of the four corners is improved from the other peripheral portions, so that a strongly bonded portion can be formed in the most balanced manner. Can be suppressed to a minimum, the adhesive strength can be secured, and the stress of the top plate can be minimized.

  According to a fourth aspect of the present invention, in order to improve the adhesive strength, a primer layer mainly composed of a silane coupling agent is formed in the lower layer of the adhesive layer, which is a silicon adhesive layer. It can be separated from the adhesive surface by dissolving in a solvent in the coupling agent.

  Furthermore, even if the adhesion point on the top plate side is small, the silane coupling agent in the silane coupling agent is bonded to the bonding point with a small amount by hydrogen bonding or van der Waals force, and the silane coupling reagent itself is also bonded to the layer. The primer layer having a large number of adhesion points and the silicon-based adhesive can be bonded, and the adhesive strength between the top plate and the silicon-based adhesive can be improved.

  The fifth invention uses an aliphatic hydrocarbon as a solvent for the silane coupling agent, so that the cracked gas generated during the thermal curing of the adhesive has little odor and can be operated with peace of mind. The upper soil can be dissolved with an aliphatic hydrocarbon in a silane coupling agent and separated from the adhesive surface.

  In the sixth invention, the use of alkoxysilane as a reagent for the silane coupling agent makes it possible to work safely with little odor, particularly in the decomposition gas generated during the thermal curing of the adhesive, and the top plate and silicon. The adhesive strength with the system adhesive can be improved.

  In the seventh invention, in order to improve the adhesive strength, the pretreatment using the silicon-based adhesive is subjected to laser processing, ultraviolet irradiation, plasma treatment, cleaning with a solvent, polishing or blasting, so that dirt on the top plate is obtained. The anchor effect can be improved by removing the surface or roughening the adhesive surface of the top plate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a perspective view of an induction heating cooker according to a first embodiment of the present invention, FIG. 2 is a perspective view of an essential portion of the induction heating cooker according to the first embodiment of the present invention, and FIG. 3 shows a plan view of the bonding surface side of the top plate with the underframe.

  In FIG. 1, a product main body 1 has a box shape, and a top plate 2 is provided to cover an upper portion of the box. The top plate 2 is made of crystallized glass on which a pan or the like is placed, and the periphery thereof has a case portion corresponding to a portion for fixing the top plate to the product main body 1.

  The case part is composed of a top frame 3 and an under frame 4, and constitutes the upper part of the product body 1 together with the top plate 2.

  The top frame 3 is made of SUS304, the underframe 4 is made of an aluminum-plated steel sheet with both sides of an iron base, and an adhesive layer 5 made of an addition reaction type silicon adhesive. It is integrated with the top plate 2.

  At this time, as shown in FIG. 3, the primer layer 6 made of a silane coupling agent is previously formed on the surface on which the adhesive layer 5 is formed on the side of the under frame 4 on the two sides of the outer peripheral portion in the longitudinal direction of the top plate 2. An adhesive layer 5 is formed thereon.

  As the silane coupling agent, 10 wt% of alkoxysilane and an aliphatic hydrocarbon solvent were used.

  A heating coil (not shown) and a thermistor (not shown) for detecting the back surface temperature of the top plate 2 from below are provided below the top plate 2.

  About the induction heating cooking appliance comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, a two-component addition reaction type silicon adhesive is applied to the top plate 2 by an automatic machine.

  And the top frame 3 previously degreased and washed is placed on this. Thereafter, the silicon adhesive is heated and cured at 120 ° C. for 5 minutes to form the adhesive layer 5.

  Thereafter, the top plate 2 is installed upside down, the silane coupling agent is thinly applied to the outer periphery of the top plate 2 on the two sides of the outer periphery in the longitudinal direction of the top plate 2, and left to stand for 30 seconds or more. A two-component type addition-reaction type silicon adhesive that exhibits liquid state is applied to the outer periphery of the substrate by an automatic machine, an underframe 4 previously degreased and washed is placed thereon, and the silicon adhesive is heated and cured to form an adhesive layer 5. Let

  In addition, the induction heating cooker of this embodiment like this is No. For comparison, a solution made of a silane coupling agent and a solvent is thinly applied to the entire circumference of the outer periphery of the top plate 2, and an underframe 4 previously degreased and washed is placed thereon, and a silicon adhesive is applied. Except that the adhesive layer 5 was formed by heating and curing, or the silane coupling agent was not used at all, induction heating cookers having the same configuration as described above were respectively No. Prepared as 2 and 3.

  Moreover, in order to compare the adhesive strength of each induction heating cooking appliance prepared in this way, it evaluated as follows. First, the top frame 3 or the under frame 4 is supported by a jig, a round bar having a diameter of 30 mm is pressed against the top plate 2 and the load when the top frame 3 and the top plate 2 are peeled, and the under frame 4 and the top plate 2. The load at the time of peeling was measured, and the results are shown in Table 1.

  As apparent from Table 1, No. 1 in which a primer layer was formed on the underframe 4 was obtained. No. 1 and 2 were No. which did not form a primer layer. The strength was higher than 3.

  Further, in the primer layer forming portion, the adhesive was almost coherently broken, whereas in the portions other than the primer layer forming portion, several points where the interface was peeled were confirmed.

  Next, in order to compare and evaluate the ease of cracking of the top plate, the following evaluation was performed. First, the top frame 3 and the under frame 4 that are bonded to the top plate 2 with the top frame 3 and the under frame 4 attached to the outer periphery of the top plate 2 in the state where the top plate 2 is lifted by 30 mm. A 20 kg weight was hung on each of the holes, and it was examined whether the top plate 2 was cracked after being left for 1 hour. Table 2 shows the results.

  In addition, the case where the top plate was cracked was rated as x, and the case where it was not cracked was marked as ◯.

  As shown in the results of Table 2, No. 1 in which a primer layer was formed on the entire circumference of the underframe 4 was obtained. No. 2 was broken in 3 out of 6 sheets, whereas No. 2 No. 1 and 3 do not break even one piece. No. 2 compared to 1 and 3 showed excellent characteristics against cracking.

  As shown in the above test test results, a strongly bonded portion is provided as in the induction heating cooker of the present embodiment, the top plate 2 is firmly bonded, and a portion having a relatively weak adhesive strength is provided. By suppressing cracking of the top plate, the risk of detachment or cracking of the top plate 2 can be further reduced.

  Although the effect can be obtained by using the primer layer 6 only for the under frame 4 as in the first embodiment, the primer layer 6 may be formed on a part of the top frame 3 in the same manner as the under frame 4. .

  Then, it is desirable that the top plate 2 is firmly bonded to either the top frame 3 or the under frame 4 so that the stress generated in the top plate 2 does not increase, and the rest is bonded auxiliary.

  Further, in the configuration in which the top frame 3 and the under frame 4 are provided as in the induction heating cooker of the present embodiment, the top frame 3 and the under frame 4 are fastened with screws or the like, and the adhesive force and the screws or the like are tightened. The top plate 2 can be fixed together with the force.

  However, care must be taken so that the top plate 2 is not excessively stressed by tightening at this time.

  In the first embodiment, n-heptane is used as the aliphatic hydrocarbon solvent. However, the present invention is not limited to this, and any material may be used as long as it is thinly applied with a brush and then allowed to dry within a few minutes. .

  The aliphatic hydrocarbon solvent is optimal because it has less odor in the cracked gas generated during the thermal curing of the adhesive, is safer than the aromatic hydrocarbon solvent, and can dissolve oil components often found in dirt.

  Moreover, although alkoxysilane was used as the silane coupling reagent, it is not limited to this, and an amine-based silane compound may be used, but the alkoxysilane has little odor to the decomposition gas generated when the adhesive is thermally cured. Is the best.

(Embodiment 2)
FIG. 4 is a plan view of the induction heating cooker according to Embodiment 2 of the present invention, FIG. 5 is a cross-sectional view of the main part of the induction heating cooker according to Embodiment 2 of the present invention, and FIG. FIG. 2 is a plan view of the bonding surface side.

  As shown in FIG. 4, the product main body 11 is a table-type induction heating cooker, and a top plate 12 is formed on the top of the product main body 11.

  The top plate 12 is made of crystallized glass on which a pan or the like is placed, and a case 13 made of PET / PBT resin is formed below the top plate 12.

  The case 13 is integrated with the top plate 12 with an adhesive layer 14 made of an addition reaction type silicon adhesive.

  At this time, a primer layer 15 made of a silane coupling agent is formed in advance on the adhesive layer 14 forming surface on the case 13 side at the outer periphery corresponding to the four corners of the top plate 12, and the adhesive layer 14 is formed on the primer layer 15. To be.

  Then, as shown in FIG. 6, a primer layer 15 made of a silane coupling agent is formed in advance on the surface on which the adhesive layer 14 is formed on the case 13 side at the outer periphery corresponding to the four corners of the top plate 12. The configuration is the same as that of the first embodiment except that the adhesive layer 5 is formed.

  Such an induction heating cooker of the present embodiment is No. 4. For comparison, a thin silane coupling agent is applied to the entire outer periphery of the top plate 12 on the case 13 side by brushing, and a case 13 that has been degreased and washed in advance is placed thereon, and the silicon adhesive is heat-cured and bonded. Except that the layer 14 was formed or no silane coupling agent was used, induction heating cookers having the same structure as described above were respectively No. Prepared as 5 and 6.

  In addition, in order to compare the adhesive strength of each induction heating cooker prepared as described above in the same manner as in the first embodiment, it was evaluated as follows. First, the case 13 was supported by a jig, a round bar having a diameter of 30 mm was pressed against the top plate 2, and the load when the case 13 and the top plate 12 were peeled off was measured. The results are shown in Table 3. .

  As apparent from Table 3, No. 1 in which a primer layer was formed on the case 13 was obtained. Nos. 4 and 5 were No. which did not form a primer layer. An adhesion strength higher than 6 was exhibited.

  Further, in the primer layer forming part as in the first embodiment, the adhesive was almost coherently broken, whereas in the areas other than the primer layer forming part, several points where the interface was peeled were confirmed.

  Next, in order to compare and evaluate the ease of cracking of the top plate, the following evaluation was performed. First, when the case 13 of the product body 11 and the top plate 12 are bonded, a hole of φ4 is formed in the case 13 near the center of the short side on both sides of the outer periphery of the top plate 12 with the top plate 12 floating 30 mm. It was hung and each weight of 20 kg was hung, and it was examined whether the top plate 12 or the case 13 was cracked after being left for 1 hour, and these results are shown in Table 4.

  As shown in the results of Table 4, No. 1 was obtained by forming a primer layer all around the outer periphery of the top plate 12 on the case 13 side. No. 5 is a case where 3 out of 6 cases 13 were cracked and one top plate 12 was cracked. As for 1 and 3, neither one piece is broken, and no. No. 2 compared to 1 and 3 showed the outstanding characteristic with respect to any crack.

  Unlike the first embodiment, in the second embodiment, the top plate 12 is cracked, and since the case is made of resin, the top plate 12 is not broken and the case 13 may be broken.

  However, as is apparent from the above results, a strongly bonded portion is provided as in the induction heating cooker of the second embodiment so that the top plate 12 is firmly bonded, and a portion having a relatively weak bonding strength is provided. By doing so, the crack of the case 13 can be suppressed similarly to the top plate 12.

  In the induction heating cooker often found in the type used in the desktop type as in the second embodiment, the top plate 12 is generally fixed only by the adhesive strength of the adhesive. The top plate 12 is required to be bonded or fixed more firmly and the stress of the top plate 12 is relieved.

  In the induction heating cooker according to the present embodiment, the primer layer is formed to improve the adhesive strength, but the laser is formed in the vicinity of a pair of two sides or four corners of the substantially rectangular top plate 12 facing each other. It is possible to obtain the same effect by improving the anchor of the adhesive by processing, ultraviolet irradiation, plasma treatment, cleaning with a solvent, polishing or blasting, and in addition to these treatments, a primer layer on these treatments By forming the adhesive strength can be further improved.

  In the present embodiment, the adhesive strength of the specific part is improved in order to change the adhesive strength of the adhesive at the specific part of the top plate. However, the adhesive strength of the top plate by the adhesive can be easily secured. In other cases or when the top plate is mechanically sandwiched, the stress of the top plate can be relaxed by reducing the adhesive strength of the adhesive at a specific location on the top plate.

  As described above, the induction heating cooker according to the present invention can reduce the stress applied to the top plate by changing the bonding strength depending on the bonding location, and therefore, the halogen heater having a bonding configuration using an adhesive. It can also be applied to cookers such as gas cookers and electric cooking heaters.

The perspective view of the induction heating cooking appliance in Embodiment 1 of this invention Sectional drawing of the principal part of the induction heating cooking appliance in Embodiment 1 of this invention Top view of the adhesive side with the underframe of the top plate The top view of the induction heating cooking appliance in Embodiment 2 of this invention Sectional drawing of the principal part of the induction heating cooking appliance in Embodiment 2 of this invention Top view of the adhesive side of the top plate with the case

Explanation of symbols

1, 11 Product body 2, 12 Top pout 3 Top frame 4 Under frame 5, 14 Adhesive layer 6, 15 Primer layer 13 Case

Claims (7)

A top plate made of crystallized glass that covers the top of the product body, and a case made of stainless steel or resin that fixes the periphery of the top plate; and the case and the top plate are made of silicon An induction heating cooker in which bonding is performed using an adhesive, and the stress applied to the top plate is reduced by changing the bonding strength depending on the bonding position. The induction heating cooker according to claim 1, wherein the shape of the top plate is substantially rectangular, and the adhesive strength of the two opposing sides of the set is improved over the other two opposing sides. The induction heating cooker according to claim 1 or 2, wherein the shape of the top plate is substantially quadrilateral, and the adhesive strength of the adhesive portion in the vicinity of the four corners is improved from that of the other peripheral portions. The induction heating cooking according to any one of claims 1 to 3, wherein a primer layer mainly composed of a silane coupling agent is formed in a lower layer of an adhesive layer that is a layer of a silicon-based adhesive in order to improve adhesive strength. vessel. The induction heating cooker according to claim 4, wherein an aliphatic hydrocarbon is used as a solvent for the silane coupling agent. The induction heating cooker according to claim 4, wherein alkoxysilane is used as a reagent for the silane coupling agent. The induction according to any one of claims 1 to 6, wherein laser processing, ultraviolet irradiation, plasma processing, cleaning with a solvent, polishing or blasting are performed as pretreatment using a silicon-based adhesive in order to improve adhesive strength. Cooker.