JP3573994B2 - Cooking device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooker that performs heating cooking. An example of the cooker is a high-frequency heating device such as a microwave oven.
[0002]
[Prior art]
When high-frequency heating cooking is performed in a microwave oven, power is supplied from a commercial power supply to a high-frequency oscillation circuit including a magnetron.
[0003]
Normally, energization and cutoff of the high-frequency oscillation circuit are performed by a relay provided on a power supply line connecting the commercial power supply and the high-frequency oscillation circuit.
[0004]
Originally, the relay requires a certain time from the energization of the electromagnetic mechanism to the closing of the contact mechanism. Further, the operation time varies depending on the structure of the relay. Therefore, the drive timing of the relay is appropriately set in consideration of the energization timing of the high-frequency oscillation circuit depending on the type of relay used.
[0005]
[Problems to be solved by the invention]
By the way, when high-frequency heating cooking is performed in a state where the microwave oven is not used for a long time, such as when the microwave oven is used for the first time in one day, the operation time of the relay is longer than when the high-frequency heating cooking is performed several times. , 1.2 to 1.5 times.
[0006]
If the operation time of the relay is delayed as described above, the energization timing of the high-frequency oscillation circuit is incorrect, and an excessive rush current is generated.
[0007]
On the other hand, for example, as shown in Japanese Patent Publication No. 2-160393, it is considered to reduce the operation time of the relay by supplying a bias current to the coil of the relay. This requires an excessive bias current, which is not preferable.
[0008]
In view of such circumstances, an object of the present invention is to prevent a delay in the operation time of a relay when starting heating cooking from a state where heating cooking is not performed for a long time in a cooking device.
[0009]
[Means for Solving the Problems]
The cooking device according to the first aspect of the present invention performs heating cooking by a heating unit, and sets a relay that permits or shuts off energization to the heating unit at a required time before a heating cooking execution command is issued by a user. Drive to warm up.
[0010]
In the cooker according to the second aspect of the present invention, in the first aspect, the time for performing the warm-up is set when a power-on operation is performed by a user.
[0011]
In the cooker according to a third aspect of the present invention, in the first aspect, the time for performing the warm-up is set when a user opens and closes a cooking chamber door.
[0012]
In the cooker according to a fourth aspect of the present invention, in the cooker according to any one of the first to third aspects, the time for performing the warm-up is a required time from the time when the relay was driven in association with the previous warm-up or the start of the heating cooking. Is performed when elapses.
[0013]
A cooking device according to a fifth aspect of the present invention is a cooking device that includes a heating unit that heats a cooking chamber, a power switch that is operated by a user, a relay that allows or blocks energization of the heating unit, Control means for controlling the operation, wherein when the power switch is turned on, the control means drives the relay in a state in which power supply to the heating means is cut off to warm up the relay.
[0014]
A cooking device according to a sixth aspect of the present invention is a heating device for heating a cooking chamber, a power switch operated by a user, two relays for allowing or interrupting energization of the heating device, and each relay and the heating device. And control means for controlling the operation of the means. When the power switch is turned on, the control means drives the other relay while the contacts of the one relay are open to warm up.
[0015]
A cooking device according to a seventh aspect of the present invention is a heating device for heating a cooking chamber, a power switch operated by a user, a detecting means for detecting an opening / closing operation of a cooking chamber door, and energizing the heating means. Or a relay that shuts off, and a control unit that controls the operation of the relay and the heating unit.When the control unit detects the opening / closing operation of the cooking chamber door by the detection unit in an ON state of a power switch, Then, the relay is driven and warmed up in a state where the power supply to the heating means is cut off.
[0016]
The cooking device according to the invention of claim 8 is a heating means for heating the cooking chamber, a power switch operated by the user, a detecting means for detecting the opening / closing operation of the cooking chamber door, and permitting electricity to the heating means. Or two relays for shutting off, and control means for controlling the operation of each relay and the heating means, wherein the control means detects the opening / closing operation of the cooking chamber door by the detection means in an ON state of a power switch. Sometimes, the other relay is driven to warm up while the contact of the one relay is open.
[0017]
The cooking device according to the ninth aspect of the present invention provides the cooking device according to the seventh or eighth aspect, wherein the control unit is configured to detect the opening / closing operation of the cooking chamber door by the detection unit first after the power switch is turned on. The relay is to be warmed up.
[0018]
A cooker according to a tenth aspect of the present invention provides the cooker according to any one of the seventh to ninth aspects, wherein the control unit controls the control means according to any one of the seventh to ninth embodiments when a required time has elapsed since the relay was driven in connection with the previous warm-up or the start of the heating cooking. Warm-up is performed again.
[0019]
In short, according to the present invention, when there is no instruction to start heating and cooking, the relay is driven to warm up. Thereby, even when receiving and executing a heating cooking start command from a state in which heating cooking has not been performed for a long time, the operation time of the relay is stabilized without delay, and the occurrence of inrush current can be suppressed. Become.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
The details of the present invention will be described based on an embodiment shown in the drawings.
[0021]
Here, a microwave oven is taken as an example of the cooker. 1 and 2 show an embodiment of the present invention. FIG. 1 is a diagram showing a circuit configuration of a microwave oven, and FIG. 2 is a flowchart for explaining the operation.
[0022]
In the figure, 1 is a commercial power supply, 2 is a fuse, 3 is an interior light, 4 is a blower motor, 5 is a high frequency oscillation circuit, 6 is a power supply circuit, 7 is an operation panel, 8 is a control circuit, 9 is a relay drive circuit, 10 Is a door switch, 11 is a monitor switch, 12 is a power switch, 13 is a power relay, and 14 and 15 are first and second start relays, respectively.
[0023]
Although not shown in detail, the high-frequency oscillation circuit 5 includes a step-up transformer, a magnetron, a diode, a capacitor, and the like, and corresponds to a heating unit described in claims.
[0024]
The power supply circuit 6 converts an AC voltage supplied from the commercial power supply 1 into a DC voltage and supplies the DC voltage to the control circuit 8 and the relay drive circuit 9, and detects a 90-degree phase position of the AC voltage supplied from the commercial power supply 1. And input it to the control circuit 7.
[0025]
The operation panel 7 is provided on a front surface of a microwave oven case (not shown) and has at least a power key 7a and a start key 7b.
[0026]
The control circuit 8 comprises a microcomputer and executes at least the processing shown in FIG.
[0027]
The relay drive circuit 9 drives the power supply relay 13 and the first and second start relays 14 and 15, and has three transistors Tr1 to Tr3 whose on / off control is performed by the control circuit 8.
[0028]
The power supply relay 13 and the coils 13a, 14a, and 15a of the two start relays 14 and 15 are connected between the transistors Tr1 to Tr3 and the power supply circuit 6, and both ends of each of the coils 13a, 14a, and 15a are connected. Are connected to surge absorbing diodes D1 to D3, respectively.
[0029]
The door switch 10 opens and closes in conjunction with the opening and closing operation of a cooking chamber door (not shown), and is open when the door is open and closed when the door is closed.
[0030]
The monitor switch 11 performs the reverse operation of the door switch 10, and is for blowing the fuse 2 when the door switch 10 or the like fails.
[0031]
The power switch 12 is opened and closed in response to a human operation of a power key 7 a provided on the operation panel 7, and is provided on a power supply line connecting the commercial power supply 1 and the power supply circuit 6.
[0032]
The power supply relay 13 has its contact 13b connected in parallel with the power supply switch 12 to a power supply line connecting the commercial power supply 1 and the power supply circuit 6, and closes when the power supply switch 12 is closed. The state is self-maintained.
[0033]
The first and second start relays 14 and 15 have their contacts 14b and 15b at required positions in the power supply line connecting the commercial power supply 1 with the interior light 3, the blower motor 4 and the high-frequency oscillation circuit 5, respectively. They are connected in series and are opened and closed in response to a manual operation of a start key 7b provided on the operation panel 7.
[0034]
Next, the operation of the microwave oven configured as described above will be described with reference to the flowchart of FIG.
[0035]
That is, when the user turns on the power key 7 a provided on the operation panel 7, the power switch 12 is closed and the AC voltage is supplied from the commercial power supply 1 to the power supply circuit 6. Is converted to a DC voltage and supplied to the control circuit 8 to activate the control circuit 8. In addition, a voltage of a required potential is applied from the commercial power supply 1 to the input terminal of the power supply circuit 6, A required signal is input from the power supply circuit 6 to the control circuit 8.
[0036]
As a result, the control circuit 8 applies a base current to the first transistor Tr1 in step S1 to make it conductive, thereby energizing the coil 13a of the power supply relay 13 and closing the contact 13b. Thus, the power supply relay 13 self-holds the closed state of the contact 13b. Thus, voltage application from the commercial power supply 1 to the power supply circuit 6 is continued.
[0037]
Subsequently, in step S2, the second start relay 15 is opened and closed one or more times to warm up.
[0038]
That is, by applying a base current to the third transistor Tr3 to make the third transistor Tr3 conductive while keeping the contact 14b of the first start relay 14 open, the coil 15a of the second start relay 15 is energized to close the contact 15b. The supply of the base current to the third transistor Tr3 is stopped, and the contact 15b of the third start relay 15 is opened.
[0039]
Then, in step S3, the process waits until the user operates the start key 7b provided on the operation panel 7.
[0040]
Here, when the start key 7b is turned on, the control circuit 8 recognizes this and executes high-frequency heating cooking in step S4.
[0041]
That is, a base current is applied to the second transistor Tr2 to make the second transistor Tr2 conductive, thereby energizing the coil 14a of the first start relay 14 and closing the contact 14b.
[0042]
Thereby, the interior light 3 and the blower motor 4 are energized and driven. Thereafter, a base current is applied to the third transistor Tr3 to turn on the third transistor Tr3, thereby energizing the coil 15a of the second start relay 15 and closing the contact 15b.
[0043]
As a result, the high-frequency oscillation circuit 5 is energized to execute high-frequency heating cooking. The operation continuation time of the high-frequency oscillation circuit 5 is managed by a timer built in the control circuit 8. This timer time is set by a timer setting key or the like (not shown) before operating the start key 7b.
[0044]
When the timer expires, the supply of the base current to the second and third transistors Tr2 and Tr3 is stopped, and the contacts 14b and 15b of the first and second start relays 14 and 15 are opened to open the high-frequency oscillation circuit. The power supply to 5 is stopped, and the high-frequency heating cooking is terminated.
[0045]
When the high-frequency heating cooking is completed in this way, in step S5, the process waits for a time T1 (for example, one minute) to elapse from the end of the high-frequency heating cooking. When the time T1 has elapsed, the supply of the base current to the first transistor Tr1 is stopped in step S6, the contact 13b of the power supply relay 13 is opened, and the power supply from the commercial power supply 1 to each unit is stopped.
[0046]
As described above, in the standby state waiting for the start key 7b to be turned on, the second start relay 15 is warmed up. Thereafter, the start key 7b is turned on to start high-frequency heating cooking. When starting the operation, the operation time required from energization of the coil 15a of the second start relay 15 to closing of the contact 15b is stabilized without delay.
[0047]
Therefore, it is possible to prevent a difference in the energization timing with respect to the high-frequency oscillation circuit 5, so that it is possible to avoid occurrence of an inrush current.
[0048]
Note that the present invention is not limited to only the above-described embodiment, and various applications and modifications are conceivable.
[0049]
(1) In the above embodiment, an example is described in which the warm-up process of the second start relay 15 is set to be performed after the power supply relay 13 is driven in accordance with the operation of the power supply key 7a. In the standby state in which the power supply relay 13 is driven in accordance with the operation described above, the warm-up process can be performed when a cooking chamber door (not shown) is opened and closed.
[0050]
(2) In the above (1), when the cooking chamber door is opened / closed and the door switch 10 is turned on / off, it is checked whether or not the warm-up process of the second start relay 15 is necessary. Preferably, the warm-up process is performed.
[0051]
Specifically, as shown in FIG. 3, steps S10 to S13 are added between step S1 and step S2 in the flowchart of FIG. 2 described in the above embodiment.
[0052]
That is, it is determined in step S10 whether or not the cooking chamber door has been opened and closed. If it is determined that the cooking chamber door has been opened and closed, the number of opening and closing operations n of the cooking chamber door is integrated in step S11, and cooking is performed in step S12. It is determined whether or not the number n of opening / closing operations of the room door is “1”.
[0053]
If it is determined in step S12 that n = 1, the warm-up process of the second start relay 15 is performed in step S2. If it is not n = 1, that is, if it is determined that the warm-up process has been performed before, In the following step S13, it is determined whether or not the time T2 (for example, 30 minutes) has elapsed from the previous warm-up process.
[0054]
If it is determined in step S13 that the time T2 has elapsed, the warm-up process of the second start relay 15 is performed in step S2. If it is determined that the time T2 has not elapsed, the process proceeds to step S3 and the start key 7b is turned off. Wait for on operation.
[0055]
In this manner, the warm-up process is not performed every time the cooking chamber door is opened and closed, but the required time T2 has elapsed since the cooking chamber door was first opened and closed in the standby state or the previous warm-up process. Only when it is recognized that the warm-up process of the second start relay 15 is necessary and this warm-up process is performed, it is possible to prevent the second start relay 15 from opening and closing more than necessary. As a result, the service life of the second start relay 15 can be extended.
[0056]
【The invention's effect】
According to the first to tenth aspects of the present invention, the relay is warmed up in a state of waiting for a heating cooking start command, so that when the heating cooking is started thereafter, the operation time of the relay is stabilized without delay. Can be made.
[0057]
For this reason, the timing of energizing the heating means can be made appropriate, so that generation of an inrush current can be avoided.
[0058]
In particular, in the inventions according to claims 3, 7, and 8, when the cooking is performed, the cooking chamber door is opened and closed and the object to be cooked is put into the cooking chamber. Since the warm-up is performed, the relay can be driven to start heating and cooking as early as possible after the warm-up of the relay.
[0059]
Therefore, when the relay is driven to start heating and cooking, the operation time of the relay can be stabilized as designed, so that the energization timing to the heating means can be more appropriately set.
[0060]
According to the ninth aspect of the present invention, the relay is not warmed up every time the cooking chamber door is opened and closed, but only when the cooking chamber door is opened and closed for the first time in the standby state of the start of heating and cooking. Since the processing is performed, it is possible to prevent the relay from being opened and closed more than necessary, which contributes to a longer life of the relay.
[0061]
According to the fourth and tenth aspects of the present invention, when the required time has elapsed from the previous warm-up processing, the relay is warmed up again. , The relay can be warmed up repeatedly. Therefore, even when heating and cooking is performed in a state where the standby time is prolonged, the relay can operate stably, which is more effective.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a circuit configuration of a microwave oven according to an embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation of the microwave oven in FIG. 1;
FIG. 3 is a flowchart for explaining the operation of a microwave oven according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Commercial power supply 5 High frequency oscillation circuit 6 Power supply circuit 7 Operation panel 7a Operation panel power key 7b Operation panel start key 8 Control circuit 9 Relay drive circuit 10 Door switch 12 Power switch 13 Power supply relay 14 First start relay 15 Second start relay

Claims (10)

A cooker for performing cooking by heating means,
A cooker, wherein a relay for allowing or interrupting energization to the heating means is driven to warm up at a required time before a heating cooking execution command is issued by a user. The cooker according to claim 1,
The cooker is characterized in that the warm-up time is set when a power-on operation is performed by a user. The cooker according to claim 1,
The cooker is characterized in that the warm-up time is set when the cooking chamber door is opened and closed by a user. The cooker according to any one of claims 1 to 3,
The cooker is characterized in that the warm-up is performed when a required time has elapsed since the relay was driven in connection with the previous warm-up or the start of heating cooking. Heating means for heating the cooking chamber, a power switch operated by the user, a relay for allowing or interrupting energization to the heating means, and a control means for controlling the operation of the relay and the heating means,
The cooking device, wherein when the power switch is turned on, the control means drives the relay and warms up in a state in which power supply to the heating means is cut off. A heating means for heating the cooking chamber, a power switch operated by a user, two relays for allowing or interrupting the supply of electricity to the heating means, and control means for controlling the operation of each relay and the heating means. ,
The cooker is characterized in that, when a power switch is turned on, the other relay is driven to warm up while the contact of the one relay is open. Heating means for heating the cooking chamber, a power switch operated by a user, detection means for detecting the opening / closing operation of the cooking chamber door, a relay for permitting or interrupting energization of the heating means, Control means for controlling the operation of the means,
The control means, when the power switch is turned on, when the detection means detects the opening / closing operation of the cooking chamber door, drives the relay in a state where the power to the heating means is cut off to warm up. Cooker characterized by the following. A heating unit for heating the cooking chamber, a power switch operated by a user, a detection unit for detecting an opening / closing operation of a cooking chamber door, two relays for allowing or interrupting energization to the heating unit, Control means for controlling the operation of the heating means,
The control means, in the on state of the power switch, when detecting the opening and closing operation of the cooking chamber door by the detection means, to drive the other relay in a state of opening the contact of the one relay, to warm up, A cooker characterized by that: The cooker according to claim 7 or 8,
The cooking device, wherein the control means causes the relay to warm up only when the detection means first detects the opening / closing operation of the cooking chamber door after the power switch is turned on. The cooker according to any one of claims 7 to 9,
The cooking device, wherein the control means causes the warm-up to be performed again when a required time has elapsed since the relay was driven in association with the previous warm-up or the start of the heating cooking.

Images