KR20120030836A - Apparatus for inspecting coating layer of inner pot for induction heating cooker and method for using the same - Google Patents

Abstract

PURPOSE: An inspection apparatus for a thermal spray layer of an inner pot of an IH(Induction Heating) cooker and the use thereof are provided to ensure improved inspection accuracy by vertically moving a guide frame up and down with a cylinder device to detect electromagnetic properties. CONSTITUTION: An inspection apparatus for a thermal spray layer of an inner pot of an IH cooker comprises a coil and a detector(150). The coil is wound a fixed number of times into a geometrically set dimension and shape. The detector applies power with a set voltage and frequency to the coil and detects the electromagnetic properties induced to the coil when the end of the coil contacts the exterior surface of a thermal spray layer of an inner pot of an IH cooker.

Description

Apparatus for inspecting coating layer of inner pot for induction heating cooker and method for using the same}

The present invention relates to a spray layer inspection apparatus of the inner pot for induction heating cooker, and more particularly, to a spray layer inspection apparatus of the inner pot for induction heating cooker to easily and efficiently determine whether the spray layer of the inner pot.

In general, a cooker refers to a utensil used to cook food, and is classified into a resistance heater heating method and an induction heating method according to a heating method for cooking. The induction heating method refers to a method of induction heating (IH) of the inner pot accommodated inside the main body by electromagnetic induction when a high frequency current is supplied to a coil wound around the lower part of the main body.

1 is a view showing an example of the cross section of the inner pot for a general induction heating cooker.

As shown in Figure 1, the inner pot 10 for an induction heating cooker is made of a material such as aluminum or clad, the body 20 made of a container shape, and a sprayed layer formed by spraying for electric induction heating on the outer surface of the body ( 30).

Here, the sprayed layer 30 is made of a magnetic metal material such as stainless iron, steel, etc. are formed by spraying on the outer surface of the body. When a high frequency current controlled by a controller is applied to the induction heating coil of the cooker body disposed around the thermal spray layer 30, the thermal spray layer 30 is heated by electromagnetic induction to heat the food for cooking. Used as Here, the thermal spray (溶 射) refers to a technique for forming a thermal spray layer is formed by changing the metal powder from a high temperature heat source into molten droplets to collide with the outer surface of the body at high speed to form a thermal spraying layer to be rapidly cooled and solidified.

On the other hand, the thermal spray layer should be formed in accordance with the thickness profile set to be suitable for heating along the vertical profile of the inner pot for the induction heating cooker. However, due to an operation error or a change in the working environment of the equipment in which the thermal spraying process is performed, a part of the thermal spraying layer formed on the outer surface of the inner pot may be formed to be very thinner than the set thickness profile, and in this case, the amount of induction heating in the corresponding part is significantly Degrades.

When cooking or cooking objects in such a state, the cooking objects located in the corresponding portions are not heated properly, and convection of the rice is not made smoothly, which causes serious problems such as poor cooking or poor cooking. It was.

Therefore, conventionally, by comparing the mass of the inner pot before the spraying and the mass of the inner pot after the spraying was judged whether the product is defective only by checking whether the sprayed mass is appropriate. However, in this case, the failure of the thermal sprayed layer in the local part cannot be determined, and if the inner pot containing the local thermal sprayed failure is applied to an induction heating cooker such as a rice cooker, the core cooking performance of the product may be poor. There was nothing but a problem.

In order to solve the above problems, the present invention relates to a spray layer inspection apparatus of the inner pot for induction heating cooker to easily and efficiently determine whether the spray layer of the inner pot.

In order to solve the above problems, the present invention is a coil wound and provided with a set number of geometrically set dimensions and appearance; And a detection device for applying an electric power having a voltage and frequency set to the coil, and detecting an electromagnetic property value induced by the coil when an end of the coil is interviewed with an outer surface of the spray layer of the inner pot for the induction heating cooker. Provided is a thermal spray inspection apparatus for the inner pot for the cooker.

Here, the end is made of a non-conductor further extends to a length set to contact the outer surface of the thermal spray layer of the inner pot for the induction heating cooker, the coil is wound around the outer circumference of the non-conductor as an enamel wire insulated It is preferred to be provided.

In this case, it is preferable that the non-conductor includes a winding part in which the coil is wound and a grip part extending at a rear end of the winding part.

In addition, the detection device is preferably an LCR inspection device for detecting the electromagnetic properties induced by the coil when interviewing the outer surface of the thermal spray layer.

In addition, the electromagnetic property value detected by the detection device is preferably a resistance value induced in the coil during the interview on the outer surface of the thermal spray layer.

Furthermore, it is preferable to further include a comparison means including a comparison value for determining whether the thermal spray layer is defective at a point corresponding to the inspection point where the electromagnetic property value is detected by the detection device.

On the other hand, the present invention is a first step of applying the power of the voltage and the frequency set to the coil is wound in a number of times set to the geometrically set dimensions and appearance of the spray layer inspection apparatus of the inner pot for induction heating cooker; A second step of detecting electromagnetic properties of each point guided to the coil in a state in which the spray layer inspection apparatus of the inner pot for the induction heating cooker is in contact with a plurality of points set along the outer surface of the inner pot for the induction heating cooker; A third step of comparing the detected electromagnetic properties of each point with a preset comparison value; And a fourth step of determining that the thermal spraying layer is defective when there is an electromagnetic property value having a deviation of the tolerance range or more from the preset comparison value. do.

Here, in the second step, the detection of the electromagnetic property value preferably includes the step of detecting the resistance value induced by the coil when the interview on the outer surface of the sprayed layer by the LCR inspection device.

In addition, in the second step, the plurality of set points is preferably arranged along the spray layer vertical profile of the inner pot.

And, in the second step, the moving unit coupled to the inspection unit is transferred to the inspection point set along the guide frame formed corresponding to the vertical profile of the inner pot for the induction heating cooker to be inspected, and toward the outer surface of the inspection point It is preferable to include the step of detecting the electromagnetic properties after descending vertically and interviewing the inspection unit, and raising the inspection unit, and repeating the transfer and detection process to the next set inspection point.

As described above, the sprayed layer inspection apparatus and its method of using the inner pot for induction heating cooker according to the present invention provides the following effects.

First, it is possible to easily and accurately determine whether the thermal spray layer is defective by comparing the electromagnetic properties detected by the inspection apparatus of the present invention with a comparison value without cutting the inner pot for the induction heating cooker.

Second, by accurately determining whether the thermal spray layer on the outer surface of the inner pot, which is an essential part of the induction heating cooker, can reduce the defect rate of the related induction cooking cooker significantly, thereby significantly improving the reliability of the product.

Third, it is possible to quickly and efficiently move the inspection device along the guide frame formed corresponding to the vertical profile of the inner pot, and to detect the electromagnetic properties as the cylinder device moves up and down toward the inspection point under certain conditions. As a result, inspection speed and accuracy can be improved.

1 is a schematic cross-sectional view of a pressure cooker which is a general induction heating cooker.
Figure 2a and Figure 2b is a perspective view showing the main part of the sprayed layer inspection apparatus of the inner pot for induction heating cooker according to an embodiment of the present invention.
Figure 3 is a schematic diagram showing a sprayed layer inspection device of the inner pot for induction heating cooker according to an embodiment of the present invention.
Figure 4 is a flow chart illustrating a method of using a sprayed layer inspection apparatus of the inner pot for induction heating cooker according to an embodiment of the present invention.
Figure 5 is a graph showing an example of extraction of the comparative value applied to the spray layer inspection apparatus of the inner pot for induction heating cooker according to an embodiment of the present invention.
Figure 6 is a graph showing an example of determining whether the sprayed layer failure of the inner pot for the plurality of induction heating cooker through the comparison value extracted in FIG.

Hereinafter, an induction heating cooker according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2a and Figure 2b is a perspective view showing the main part of the sprayed layer inspection apparatus of the inner pot for induction heating cooker according to an embodiment of the present invention.

As shown in Figure 2a, the spray layer inspection apparatus of the inner pot for the induction heating cooker comprises a coil 55, and the detection device (see 150 of FIG. 3). The coil 55 end of the inspection device configured as described above may detect electromagnetic properties in the state of being interviewed in a manner of being in close contact with the outer surface of the sprayed layer formed on the inner pot for an induction heating cooker, and estimate the thickness of the sprayed layer. By doing so, it can be efficiently applied to determine the presence of a defect. As such, the coil 55 is wound alone or to the non-conductor 51 to form the inspection unit 50.

In detail, the coil 55 is provided to be wound in a set number of geometrically set dimensions and appearance. To this end, the coil 55 may be provided wound around the outer circumference of the non-conductor 51 made of synthetic resin, etc. as an insulating material, the end of the non-conductor 51 on the sprayed layer outer surface of the inner pot for an induction heating cooker. It is preferably provided extending to a length set for the interview. At this time, the non-conductor 51 can be changed into various shapes and structures if the coil 55 can be wound a predetermined number of times, the coil 55 is preferably made of enameled wire insulated from the outer circumference. Both ends of the wound coil 55 is exposed through the rear end of the non-conductor 51, the exposed both ends are extended to be connected to the detection device by a coated wire 56.

In addition, the non-conductor 51 preferably includes a winding portion on which the coil 51 is wound, and a grip portion 59 extending at a rear end of the winding portion. Accordingly, while the user grips the grip 59 or moves the inspection unit 50 to a plurality of inspection points disposed on the inner surface of the inner pot in which the spray layer is formed in a state where the grip 59 is coupled to other movement aids. The spray layer can be inspected for defects.

In addition, as shown in Figure 2b, it is preferable that the insulating material 57 is attached to the outer peripheral surface of the coil 55 wound on the non-conductor 51. That is, the insulating material 57 prevents accidental hand contact with the coil 55 even when the user grips the grip 59 by hand and improves the measurement accuracy of the inspection unit 50. To perform.

On the other hand, Figure 3 is a schematic diagram showing a spray layer inspection apparatus of the inner pot for induction heating cooker according to an embodiment of the present invention.

As shown in FIG. 3, the inspection unit 50, in which the coil 55 is wound around the non-conductor 51, is coupled to the moving device 120, and the moving device 120 includes an inner pot having a sprayed layer. Preferably, the guide frame 101 is movably mounted in a shape corresponding to the outer circumferential profile of the inspection object. Here, the scale 102 may be displayed on the edge of the guide unit 101 corresponding to the plurality of inspection points.

In addition, the support frame 110, the inner pot 10 is placed on the lower portion of the guide frame 100 is installed, the fixing frame for fixing the fixed position is formed in the upper surface of the support frame 110 and the opening of the inner pot (10) Preferably, 111 is protruded. In addition, the moving unit 120 to which the inspection unit 50 is coupled includes a plurality of rollers and a motor for conveying along the cylinder and the guide unit 101 for the shangdong, the cylinder, the roller and the motor The driving is controlled by the controller 160 to perform an automated inspection operation. To this end, the controller 160 is preferably connected to the mobile device 120 and the detection device 150 and the wires (151,161).

As such, the inspection unit 50 may minimize the measurement error by allowing the mobile device 120 to accurately measure the electromagnetic property values while being interviewed precisely at each inspection point as the direction and the uniform pressing force at the correct position.

Here, the detection device 150 is preferably made of an LCR inspection device for detecting the electromagnetic properties induced by the coil 55 when interviewing the outer surface of the sprayed layer. The LCR test apparatus is a device for measuring electromagnetic properties such as resistance, capacitance, impedance, reactance, conductance, and susceptance.

On the other hand, the inspection unit 50 is disposed perpendicular to the surface of the inspection point of the inner pot 10 while moving along the guide portion 101, and performs the inspection process in the state interviewed at the inspection point while moving up and down do. In detail, both ends of the coil 55 of FIGS. 2A and 2B extend to the outside and are connected to the detection device 150. The power source having the frequency and voltage value set by the detection device 150 is the coil 55. Is applied.

In this case, the detection device 150 applies power to the coil 55 to detect resistance, etc. induced in the sprayed layer. In this case, the resistance value induced and detected is relatively different depending on the frequency or voltage value of the input power. do. Therefore, the power applied to the coil 55 has a frequency and voltage value set as 100 kHz, 1V.

As such, in the thermal spraying layer perpendicular to the ends of the coils 55 to the non-conductor 51 of the inspection unit 50, resistance and reactance may be detected by electromagnetic induction. Here, the resistance detected when the inspection unit 50 is interviewed at the inspection point has a correlation according to the geometric shape of the thermal sprayed layer and the thickness of the thermal sprayed layer, and the resistance detected when the thickness of the thermal sprayed layer is thick in a straight plane. Also linearly increased. On the other hand, it is understood that the reactance is influenced not only by the geometric shape of the thermal sprayed layer and the thickness of the thermal sprayed layer but also by the thickness of the aluminum body forming the inner pot.

That is, the electromagnetic properties such as resistance, capacitance, impedance, reactance, conductance, and susceptance detected by the LCR inspection apparatus have a correlation with the thickness of the thermal sprayed layer depending on the material and the geometrical conditions. Although it may be used for the layer inspection, it is preferable to check whether the thermal spray layer is defective by using a resistance value that provides more accurate information when inspecting the thermal spray layer as described above.

Therefore, it is possible to inspect whether the thermal spray layer is defective based on a resistance value among electromagnetic property values detected when power is applied to the coil 55. To this end, the inspection apparatus further comprises a comparison means including a comparison value for determining whether the thermal spray layer is defective at a point corresponding to the inspection point where the electromagnetic property value is detected. The comparison value is provided as data in a graph format. Accordingly, the comparison means may be included in the controller 160 as a storage medium including a digitized comparison value and a comparison operation device.

On the other hand, according to various experimental results, it is understood that the thickness of the thermal spray layer increases as the measured resistance value increases in the flat portion of the inner surface of the inner pot for induction heating cooker, the portion that is bent round in the outer surface of the inner pot The measured resistance was relatively small due to the rapid change in geometrical shape. This result seems to partially contribute to the tolerance due to the curvature of the surface contact position between the inspection portion and the inspection point of the spray layer inspection apparatus of the inner pot for induction heating cooker according to the present invention in the rounded bent portion.

However, there was a correlation in which the thickness of the thermal sprayed layer was increased in the comparison between the local parts even in the portion bent roundly in the outer surface of the inner pot.

As described above, the process of inspecting the sprayed layer by measuring the electromagnetic properties in the state interviewed on the outer surface of the sprayed layer of the inner pot as follows.

Figure 4 is a flow chart illustrating a method of using a spray layer inspection apparatus of the inner pot for induction heating cooker according to an embodiment of the present invention.

As shown in FIG. 4, first, a power having a set frequency and voltage is applied to the coil 55 provided and wound to the inspecting unit 50 according to the present invention.

In this way, power is applied to the coil 55, and the inspection unit is in contact with a plurality of inspection points set along the outer surface of the inner pot for the induction cooking object to be inspected (S110), each of which is guided to the coil 55. Electrical properties of each inspection point are detected (S120). At this time, the detection of the electrical property value is preferably detected by the detection device 150, such as the LCR tester to detect the resistance value induced in the coil 55 when the interview on the outer surface of the sprayed layer.

In this case, the set plurality of inspection points, as shown in Figure 3, is preferably arranged along the vertical profile of the sprayed layer of the inner pot. As such, the moving device 120 for repeatedly measuring the plurality of inspection points on the vertical profile is preferably controlled by the controller 160. In detail, referring to FIG. 3, the moving unit 120 to which the inspection unit 50 is coupled is transferred to an inspection point set along the guide frame 100 formed corresponding to the vertical profile of the inner pot for the inspection target induction cooker. Here, as shown in FIG. 3, the vertical profile refers to an outer circumferential profile along one direction among radial to radial directions of the inner pot outer surface.

Thereafter, the test unit 50 is vertically lowered toward the outer surface of the test spot, and the electromagnetic properties are detected after the test part 50 is interviewed with the sprayed layer. Next, by raising the inspection unit 50 and repeating the transfer and detection process to the next set inspection point, the electromagnetic property values of the plurality of inspection points can be detected quickly and efficiently.

Furthermore, as shown in Fig. 3, after the plurality of points on the vertical profile in one direction are inspected, the inner pot is rotated a predetermined angle in the circumferential direction and then examined in detail by inspecting the plurality of points on the vertical profile in the other direction. You can also check for local defects in the thermal spray layer.

Thereafter, the electromagnetic property values for each point are compared with a preset comparison value. In this case, as will be described later, the comparison value may be provided as data in a graph format for determining whether the thermal spray layer is defective at a point corresponding to an inspection point at which the electromagnetic property value is detected, and the comparison value is digitized data. It is preferably stored in a storage medium.

Through this, when there is an electrical property value having a deviation of the tolerance range or more from the preset comparison value, it may be determined that the thermal sprayed layer is defective.

In detail, referring to Figures 5 and 6, the extraction of the comparison value applied to the spray layer inspection apparatus of the inner pot for induction heating cooker according to an embodiment of the present invention and to determine whether the spray layer failure through the extracted comparison value An example is as follows. Each test point on the graph is arranged in horizontal coordinates sequentially with a predetermined distance from the bottom surface to the side of the inner pot.

5 is a graph showing resistances (units) respectively detected by the inspection apparatus of the present invention at a plurality of inspection points along the vertical profile of the inner pot for an induction heating cooker. Here, the inner pot for the induction heating cooker is further verified as being good through detailed experiments such as cooking test and measurement of the sprayed layer thickness after cutting. Nevertheless, as shown, the measuring points 3 to 5 were rounded curved edge portions of the inner pot, and the resistance values measured at the corresponding portions were detected to be relatively small.

However, as a result of the additional verification as described above, the sprayed layer of the inspection target inner pot corresponding to the graph shown in FIG. Therefore, the upper and lower reference lines (A) and the lower limit reference lines (by applying the upper and lower tolerances based on the average values of the resistances Rs detected in the plurality of good inner pots (lines 1 to 4) as described above). Each of B) can be set and presented as a comparison value.

Of course, the comparison value is provided differently for each model, the tolerance may be set differently for each inspection point in consideration of the degree of contribution to the induction heating performance for each point of the thermal spray layer.

On the other hand, Figure 6 is a graph showing the resistance value detected for each point on the vertical profile of the plurality of inspection target inner pot by the spray layer inspection apparatus of the inner pot for induction heating cooker according to the present invention.

As shown in Figure 6, the resistance (Rs) detected in some of the sprayed layers on the inner surface of the plurality of inspection targets is a value deviated from the comparison value set by the upper reference line (A) and the lower reference line (B). Have For example, at the measurement point 3, some of the inspection inner pots (lines 5 to 8) belong to the resistance area C separated from the lower limit reference line B, and thus the inner pots belonging to the resistance area C separated through the measurement. It can be determined that the thermal sprayed layer is defective.

Such comparison value data may be digitized and stored in a storage medium. The resistance value detected by a detection device such as an LCR inspection device may be quickly converted by a comparison operation previously stored in a controller and a comparison operation by a calculation processing circuit. It may be determined whether or not there is a failure to output the result through the warning sound or the display.

Through this process, it is possible to significantly reduce the defective rate of the related induction cooker by accurately determining whether the thermal spray layer on the outer surface of the inner pot, which is an essential part of the induction cooker, is significantly reduced, thereby contributing to improving the reliability of the product. have.

As described above, the present invention is not limited to the above-described specific preferred embodiments, and modifications apparent by those skilled in the art to which the present invention pertains without departing from the technical spirit of the present invention claimed in the claims. Implementations are possible and such modifications are within the scope of the present invention.

10: inner pot 20: body
30: thermal spray layer 50: inspection unit
51: non-conductor 55: coil
100: guide frame 101: guide
110: support frame 120: moving device
150: detection device 160: controller

Claims (10)

A coil wound and provided with a set number of geometrically set dimensions and appearances; And
Induction heating cooking comprising a detection device for applying the power of the voltage and frequency set to the coil and detecting the electromagnetic properties induced by the coil when the end of the coil is interviewed on the outer surface of the spray layer of the inner pot for the induction heating cooker Spraying layer inspection device for inner pot. The method of claim 1,
The end is made of a non-conductor further extends to a length set to contact the outer surface of the sprayed layer of the inner pot for induction cooking,
The coil is sprayed layer inspection apparatus of the inner pot for induction heating cooker, characterized in that the outer circumference is insulated enameled wire wound around the non-conductor. The method of claim 2,
The non-conductor is a spraying layer inspection device of the inner pot for induction heating cooker, characterized in that it comprises a winding portion that the coil is wound, and a grip portion extending to the rear end of the winding portion. The method of claim 1,
The detection device is a spray layer inspection device, characterized in that the LCR inspection device for detecting the electromagnetic properties induced by the coil when interviewing the outer surface of the sprayed layer. The method of claim 1,
Electromagnetic property value detected by the detection device is a spray layer inspection apparatus of the inner pot for induction heating cooker, characterized in that the resistance value induced by the coil when interviewing the outer surface of the sprayed layer. The method of claim 1,
A spraying layer of the inner pot for an induction cooker, further comprising a comparison means including a comparison value for determining whether the thermal spraying layer is defective at a point corresponding to an inspection point where the electromagnetic property value is detected by the detection device. Inspection device. A first step of applying power of a voltage and a frequency set to a coil wound and provided at a number of times geometrically set to the inspection unit and set to an outline;
A second step of detecting electromagnetic property values of each point guided to the coil in a state in which the inspection unit is in contact with a plurality of inspection points set along the outer surface of the inner pot for the induction cooking object to be inspected;
A third step of comparing the detected electromagnetic properties of each point with a preset comparison value; And
And a fourth step of determining that the thermal spraying layer is defective when there is an electromagnetic property value having a deviation greater than or equal to a tolerance range from the preset comparison value. The method of claim 7, wherein
In the second step, the detection of the electromagnetic material property value of the inner pot for induction heating cooker comprising the step of detecting the resistance value induced by the coil when the interview on the outer surface of the sprayed layer by an LCR inspection device. How to use the spray layer inspection device. The method of claim 7, wherein
In the second step, the set plurality of points are sprayed layer inspection method of the inner pot for induction heating cooker, characterized in that arranged along the vertical profile of the sprayed layer of the inner pot. The method of claim 7, wherein
In the second step,
Transferring the mobile unit coupled to the inspection unit to an inspection point set along a guide frame formed corresponding to the vertical profile of the inner pot for the induction heating cooker to be inspected;
Vertically descending toward an outer surface of the inspection point to interview the inspection unit, and then detecting electromagnetic property values;
The method of using a spray layer inspection apparatus of the inner pot for induction heating cooking, characterized in that the step of raising the inspection unit, and repeating the transfer and detection process to the next set inspection point.

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