JP3941697B2 - Induction heating cooker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction heating cooker that reduces noise during cooking.
[0002]
[Prior art]
Conventionally, as this type of induction heating cooker, for example, there has been one described in Patent Document 1. FIG. 8 shows a conventional induction heating cooker described in the publication. In FIG. 8, 1 is a pan to be heated, 2 is a top plate, 3 is a heating coil provided below the top plate 2, 4 is an inverter for supplying high-frequency current to the heating coil, and 5 is a configuration of the inverter. An aluminum radiator 6 is attached as a power switching element.
[0003]
Reference numeral 7 denotes a cooling fan for cooling the heat generating components, and 8 denotes a power cord. Reference numeral 9 denotes cooling fan speed control means for controlling the voltage supplied to the cooling fan 7 to control the speed of the cooling fan. The cooling fan speed control means 9 operates according to a temperature detected by a thermistor which is a temperature detection means 10 attached to the radiator 6.
[0004]
Prior Symbol configuration, when the power supply is a heating coil 4 is turned on is energized, cooking pot 1 is heated is started by induction heating. At this time, the power switching element 5 generates heat. This heat generation increases as the output increases, that is, as the current flowing through the heating coil 3 increases. In order to prevent the power switching element 5 from rising in temperature due to heat generation and being thermally damaged, a radiator 6 is attached and further cooled by a cooling fan 7. Since the noise is generated when the cooling fan 7 is operated, it is necessary to suppress the speed of the cooling fan 7 as much as possible to reduce the noise. Therefore, the temperature detector 10 is provided in the radiator 6 and the speed of the cooling fan is varied according to the detected temperature. That is, when the detected temperature is low, the speed of the cooling fan 7 is reduced, the cooling capacity is reduced, and at the same time the level of noise generated from the cooling fan 7 is kept low.
[0005]
Moreover, the induction heating cooker shown in FIG. 9 has already been proposed by the same applicant.
[0006]
In FIG. 9, reference numeral 11 denotes a main body that constitutes the outline of the heating cooker. Further, on the top surface of the top plate 12, there are provided a heating coil 14 for induction heating of the pan, an induction heating means 16 comprising an inverter 15, and a heating means 17 for heating the radial heater. In addition, a cooling fan 18 is provided below the intake portion 13, and an inverter 15 is arranged in the blowing direction of the cooling fan 18.
[0007]
Further, on the left side of the circuit unit such as the inverter 15, heating means 19 for heating the roaster heater in the heating chamber is provided below the heating coil 14. An input unit 20 is provided next to the heating chamber, that is, on the front surface of the main body 11.
[0008]
In the above configuration, the fan speed is determined according to the heating output as shown in FIG. 10, and the rotation speed of the cooling fan changes according to the heating output set by the input means 20. While maintaining sufficient cooling of the equipment, the noise was reduced by minimizing the number of rotations of the cooling fan.
[0009]
[Patent Document 1]
JP 6-4 5 058 (page 3-5, FIG. 1)
[0010]
[Problems to be solved by the invention]
However, both when the output is increased to the current set thermal power and when the output is decreased, the rotation speed of the cooling fan and the heating output are varied almost simultaneously. If the set thermal power is reduced in a stable state near the heat-resistant temperature, the output decreases and the cooling fan speed also decreases. When the temperature rise rate is higher, the temperature of the component transiently exceeds the heat-resistant temperature, causing a problem that the reliability is impaired.
[0011]
The present invention solves the above-described conventional problems. When the output is reduced to reach the currently set thermal power, the number of cooling fan rotations is not immediately reduced, thereby preventing thermal destruction due to insufficient cooling of the heat generating components. It aims at providing the induction heating cooker which prevented.
[0012]
[Means for Solving the Problems]
In order to solve the above-described conventional problems, the induction heating cooker of the present invention does not simultaneously change the heating output and the rotation speed of the cooling fan, and the heating output and the rotation of the cooling fan according to an increase in the set thermal power. In this configuration, the timing for changing the number is changed.
[0013]
As a result, it is possible to sufficiently maintain the cooling of the heat generating components while suppressing the number of rotations of the cooling fan to the minimum necessary to reduce noise.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 is an induction heating means, an input means for setting an output of the induction heating means, a cooling fan for cooling the induction heating means, and the cooling fan according to an input from the input means. A cooling fan rotation speed control means for changing the rotation speed of the cooling fan, and a control means for operating the induction heating means. The control means rotates the rotation speed of the cooling fan in response to a signal from the input means. Thermal breakdown due to insufficient cooling of heat-generating parts by preliminarily suppressing heat generation of parts that increase due to output increase by providing a delay time to the output increase timing to increase the output of the induction heating means and increase the output of the induction heating means Can be prevented.
[0015]
According to the second aspect of the present invention, in particular, the rotation speed of the cooling fan is controlled by the cooling fan rotational speed control means according to the first aspect of the invention, so that the cooling fan can be rotated even though the heat-generating component is hot. It is possible to prevent insufficient cooling due to the reduction in the number and to prevent the user from feeling uncomfortable due to a change in sound due to a change in the rotation speed of the fan.
[0016]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0017]
Example 1
FIG. 1 shows an operation characteristic diagram of the induction heating cooker in the first embodiment of the present invention.
[0018]
In FIG. 1, 21 is an induction heating means comprising a heating coil or an inverter, 22 is an input means for setting the output of the induction heating means 21, 23 is a microcomputer that operates the induction heating means in response to an input from the input means 22, etc. The control means 24 is a cooling fan for cooling the induction heating means 21, and 25 is a cooling fan rotation speed control means for changing the rotation speed of the cooling fan 24 in accordance with an input from the input means 22.
[0019]
In the induction heating cooker configured as described above, its operation and action will be described below with reference to FIG. 2 showing fluctuations in the output of the induction heating means and the rotation speed of the cooling fan.
[0020]
The user puts the food in the pan and places it on the top plate located on the induction heating means 21 (not shown). When the user sets the heating power “middle” (1400 W to 2000 W in this embodiment) by the input means 22, the control means 23 is set by operating the induction heating means 21 in response to a signal from the input means 22. Induction heating the pot with heat. When the induction heating means 21 is operated, the components of the inverter consisting of the heating coil and switching elements that constitute the induction heating means generate heat, and may exceed the heat-resistant temperature, resulting in thermal destruction. Therefore, the cooling fan 24 is driven. And cool the heat-generating parts. However, if the heating output is small, the loss of heat-generating parts is small. Therefore, when the fan rotation speed control means 25 receives a signal of the heating power “medium” from the input means 22, the cooling fan 24 has a medium speed (2300 rpm in this embodiment). Is transmitted to drive the cooling fan 24 at medium speed.
[0021]
Next, the setting is lowered to the heating power “weak” (300 W to 1000 W in this embodiment) by the input means 22. When receiving a signal for lowering the setting from the input means 22, the control means 23 first decreases the output of the induction heating means 21, contrary to when the set heating power is increased, and after a few seconds (20 seconds in this embodiment) the fan The rotational speed control means 25 drives the cooling fan 24 at a low speed (2000 rpm in the present embodiment) in order to perform cooling corresponding to the loss of the heat-generating component with the heat power “weak”. That is, when the set thermal power is decreased, the timing for decreasing the rotational speed of the cooling fan is delayed for several seconds.
[0022]
Further, the setting is increased to the heating power “strong” (3000 W in this embodiment) by the input means 22. Upon receiving a signal for raising the setting from the input means 22, before the control means 23 increases the output of the induction heating means 21, the fan rotation speed control means 25 performs cooling corresponding to the heat generation of the heat-generating component with the heating power “strong”. For this purpose, the cooling fan 24 is driven at a high speed (2800 rpm in this embodiment). After a few seconds (20 seconds in this embodiment), the output of the induction heating means is increased. That is, when the set heating power increases, the output increase timing of the induction heating means is delayed for several seconds.
[0023]
In this embodiment, the number of rotations of the cooling fan is controlled in three stages according to the set thermal power, but the number of rotations of the cooling fan is not limited.
[0024]
As described above, in this embodiment, the order or time for changing the output of the induction heating means and the number of rotations of the cooling fan is changed according to the increase or decrease of the set thermal power, thereby preventing thermal destruction of parts due to insufficient cooling. be able to.
[0025]
Further, in this embodiment, the timing for reducing the rotation speed of the cooling fan is delayed with respect to the timing for lowering the output of the induction heating unit, but the fluctuation timing is not particularly delayed, and the rotation speed of the cooling fan is set as the target rotation speed. For example, by gradually reducing the rotation speed by 20 rpm per second, it is possible to prevent the user from feeling uncomfortable due to a change in noise that occurs when the rotational speed of the fan fluctuates.
[0026]
( Reference Example 1 )
FIG. 3 shows an operational characteristic diagram of the induction heating cooker in the first embodiment of the present invention. In FIG. 3, reference numeral 26 denotes a delay time calculation means, which is configured to change the delay time according to the output of the induction heating means, and is different from the first embodiment in that a delay time calculation means is provided.
[0027]
The operation and action of the induction heating cooker configured as described above will be described below.
[0028]
As in the first embodiment, the user puts the food in the pan and places it on the top plate located on the induction heating means 21 (not shown). When the user sets the heating power “strong” (3000 W in this reference example) with the input means 22, the control means 23 receives the signal from the input means 22 and operates the induction heating means 21 to set the heating power set. Induction heating the pan at When the fan rotational speed control means 25 receives the signal of the heating power “strong” from the input means 22, it sends a signal to drive the cooling fan 24 at a high speed (2800 rpm in this reference example), and drives the cooling fan 24 at a high speed.
[0029]
Next, the setting is lowered to the heating power “medium” (1400 W to 2000 W in this reference example) by the input means 22. When receiving a signal to lower the setting to the heating power “medium” from the input means 22, the control means 23 reduces the output of the induction heating means 21, and the delay time calculation means 26 is determined according to the output of the induction heating means “medium”. The delay time (30 seconds in this reference example) is calculated. When the time determined by the delay time calculation means elapses, the fan rotation speed control means 25 drives the cooling fan 24 at medium speed (2400 rpm in this reference example). The heat generating component is sufficiently cooled by continuously driving the cooling fan at high speed for 30 seconds.
[0030]
Further, the setting is lowered to the heating power “weak” (300 W to 1000 W in this reference example) by the input means 22. When receiving a signal for reducing the setting to the heating power “weak” from the input means 22, the control means 23 reduces the output of the induction heating means 21, and the delay time calculating means 26 determines the delay time (corresponding to the heating power “weak” ( In this reference example, 15 seconds) is calculated. When the time determined by the delay time calculation means elapses, the fan rotation speed control means 25 drives the cooling fan 24 at a low speed (2000 rpm in this reference example). When the output of the induction heating means is reduced, the loss from the heat generating parts is reduced, so that sufficient cooling can be achieved even if the delay time is short.
[0031]
As described above, by changing the delay time according to the output of the induction heating unit in this reference example, the noise generated from the cooling fan 24 when the output of the induction heating unit is small is further reduced than in the first embodiment. In this state, it is possible to prevent thermal destruction of parts due to insufficient cooling.
[0032]
( Reference Example 2 )
FIG. 4 shows an operation characteristic diagram of the induction heating cooker in the second reference example of the present invention. 26 the delay time calculating means 4, 27 is a counting means for counting a continuous heating time, and is configured to change the delay time in response to input from the timer, differs clocking Reference Example 1 Means are provided, and the delay time is changed by an input from the time measuring means.
[0033]
In the induction cooking device configured as described above, the operation and action will be described below with reference to FIG. 5 showing the relationship between the continuous heating time and the delay time.
[0034]
As in the first embodiment, the user puts the food in the pan and places it on the top plate located on the induction heating means 21 (not shown). When the user sets the heating power “strong” (3000 W in this reference example) with the input means 22, the control means 23 receives the signal from the input means 22 and operates the induction heating means 21 to set the heating power to the set power. Induction heating the pan. When the fan rotational speed control means 25 receives the signal of the heating power “strong” from the input means 22, it drives the cooling fan 24 at a high speed (2800 rpm in this reference example).
[0035]
After 3 minutes, the input means 22 lowers the setting to “medium” (1400 W to 2000 W in this reference example). When receiving a signal for lowering the setting to “medium” from the input means 22, the control means 23 reduces the output of the induction heating means 21. The time measuring means 27 measures the continuous heating time as 3 minutes, and the delay time calculating means 26 calculates a delay time (30 seconds in this reference example) determined according to the continuous heating time input from the time measuring means. When the time determined by the delay time calculation means elapses, the fan rotation speed control means 25 drives the cooling fan 24 at medium speed (2400 rpm in this reference example). When the setting is lowered after 1 minute, the delay time calculation means calculates another delay time (10 seconds in this reference example) according to the continuous heating time of 1 minute. In this reference example, the delay time is proportional to the continuous heating time, but the delay time calculation method is not limited, such as changing the delay time by providing a threshold for the continuous heating time.
[0036]
As described above, by changing the delay time according to the continuous heating time in this reference example, the noise generated from the cooling fan 24 in a state where the continuous heating time is short and the parts do not generate much heat is obtained from the first embodiment. Furthermore, it is possible to prevent thermal destruction of parts due to insufficient cooling.
[0037]
( Reference Example 3 )
FIG. 6 shows an operation characteristic diagram of the induction heating cooker in the third reference example of the present invention. 26 the delay time calculating means 6, 28 is a temperature detecting means for detecting the temperature of the induction heating means, and is configured to change the delay time in response to an input from the temperature sensing means, as in Reference Example 2 The difference is that a temperature detecting means is provided, and the delay time is changed by an input from the temperature detecting means.
[0038]
In the induction cooking device configured as described above, its operation and action will be described below with reference to FIG. 7 showing the relationship between the temperature of the induction heating means and the delay time.
[0039]
When the user sets the heating power “strong” (3000 W in this reference example) with the input means 22 as in Reference Example 2 , the control means 23 receives the signal from the input means 22 and operates the induction heating means 21. , Induction heating the pot with the set heat. When the fan rotational speed control means 25 receives the signal of the heating power “strong” from the input means 22, it drives the cooling fan 24 at a high speed (2800 rpm in this reference example).
[0040]
Next, the setting is lowered to the heating power “medium” (1400 W to 2000 W in this reference example) by the input means 22. When receiving a signal for lowering the setting to “medium” from the input means 22, the control means 23 reduces the output of the induction heating means 21. When the temperature detection means 28 provided in the vicinity of the element of the inverter that generates heat, such as a heating coil or a switching element, detects the temperature of the induction heating means, the delay time calculation means 26 depends on the temperature of the induction heating means input from the temperature detection means. Calculate the delay time. In this reference example, the delay time is calculated as a value proportional to the input from the temperature detecting means, such as a delay time of 20 seconds if the detected temperature is 40 ° C., a delay time of 30 seconds if the detected temperature is 50 ° C. ing.
[0041]
In this reference example, the delay time is proportional to the continuous heating time, but the delay time calculation method is not limited, such as changing the delay time by providing a threshold for the continuous heating time.
[0042]
As described above, in this reference example, by changing the delay time according to the temperature of the induction heating means, it is possible to perform efficient cooling according to the degree of heat generation of the components, so that the noise generated from the cooling fan 24 Can be further reduced as compared with the first embodiment.
[0043]
【The invention's effect】
As described above, according to the first and second aspects of the invention, the timing for changing the heating output and the timing for changing the rotation speed of the cooling fan are separated, and the timing for changing the rotation speed of the cooling fan according to the increase of the heating output. By changing the configuration of the heat generating component, it is possible to sufficiently cool the heat generating component while suppressing the number of rotations of the cooling fan to the minimum necessary.
[Brief description of the drawings]
FIG. 1 is an operation characteristic diagram of an induction heating cooker in Embodiment 1 of the present invention. FIG. 2 is a graph showing the input means of the induction heating cooker, the output of the induction heating means, and the rotation speed of the cooling fan in Embodiment 1 of the present invention. FIG. 3 is a diagram showing the change over time. FIG. 3 is an operation characteristic diagram of the induction heating cooker in Reference Example 1 of the present invention. FIG. 4 is an operation characteristic diagram of the induction heating cooker in Reference Example 2 of the present invention. The figure which shows the relationship between the continuous heating time and delay time in the induction heating cooking appliance in the reference example 2 of FIG. 6 [FIG. 6] The operation characteristic figure of the induction heating cooking appliance in the reference example 3 of this invention [FIG. 7] The reference example of this invention The figure which shows the relationship between the temperature of the induction heating means and the delay time in the induction heating cooking appliance in 3 [FIG. 8] The exploded perspective view of the conventional induction heating cooking appliance [FIG. 9] The decomposition | disassembly of the induction heating cooking appliance already proposed Perspective view [Figure 10] Already proposed Figure [Description of symbols] of the induction heating output of the heating cooker that shows the relationship between the cooling fan speed
DESCRIPTION OF SYMBOLS 21 Induction heating means 22 Input means 23 Control means 24 Cooling fan 25 Fan rotation speed control means 26 Delay time calculation means 27 Timing means 28 Temperature detection means

Claims (2)

Induction heating means, input means for setting the output of the induction heating means, a cooling fan for cooling the induction heating means, and a cooling fan rotation for changing the number of rotations of the cooling fan according to the input from the input means Number control means and control means for operating the induction heating means, wherein the control means is the induction heating after a rotation speed increase timing for increasing the rotation speed of the cooling fan in response to a signal from the input means. An induction heating cooker provided with a delay time for delaying the output increase timing for increasing the output of the means. The induction heating cooker according to claim 1, wherein the cooling fan rotation speed control means gently changes the rotation speed.

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