JPH0315312B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an improvement of a control panel for an appliance equipped with a door, and is intended to innovate the structure of embedding the control panel in the door of, for example, a microwave oven or an electric oven.

2. Description of the Related Art Devices equipped with a door and an operation panel include microwave ovens, electric ovens, and composite devices thereof. These have a heating chamber in which an object to be heated is placed, and a door is pivotally supported in the opening of the heating chamber so as to be openable and closable. The operation panel is equipped with operation pieces for controlling heat sources such as magnetrons. For such devices, many structures have already been proposed in which the operation panel is embedded in the door. The best example is shown in US Pat. No. 4,255,640 (Bressler). This device has an operating piece and a controller embedded in the door, and this controller controls the magnetron and other devices placed on the main body. The controller and components such as the magnetron are connected by flexible cables that pass near or through the door hinge. This configuration not only makes effective use of the door space and allows for a compact design, but it also allows for signal transmission between the door and the main body by passing a flexible cable through the vicinity of the hinge. became easier.

Problems to be Solved by the Invention However, this system still has the fundamental problem of cable durability. In the case of microwave ovens, the lifespan of the door is set to be at least 100,000 times. It was extremely difficult to select a flexible printed cable or optical fiber that could withstand repeated bending 100,000 times at a low price for consumer use.

Next, if the cable were to short circuit, would there be any danger? When the magnetron continuously oscillates, the temperature outside the aircraft becomes extremely high, posing a high risk of fire or burns. In this respect, the cable method had a fail-safe problem.

The cited document also points out that the signal transmission between the door and the main body is made more resistant to noise caused by microwaves and the like because the controller is built into the door. However, the gap between the door and the main body, called the hinge part,
Can we really say that a structure that allows cables to pass through areas where microwaves are likely to leak is resistant to noise? There remains a high risk that the cable itself will pick up noise and cause the magnetron to malfunction.

In view of these conventional problems, the present invention realizes a system that is excellent in durability, takes into account fail-safe aspects, and is resistant to noise.

Means for Solving the Problems In order to solve the above problems, the heating device of the present invention includes a relay for controlling power supply to the heating means, a conductive piece connected to the operating coil of this relay, and a heating device for heating the heating means. A main body with built-in means, relays, conduction pieces, etc., an operation piece for setting the heating time limit, etc., a display section for displaying the set heating time limit, etc., an operation panel including these operation pieces and the display section, and an operation panel. A main control unit that decodes the signal input from the main control unit, displays it on the display unit, and controls the power supply to the heating means, a contact piece connected to the signal line output from this main control unit, and a contact piece that operates these parts. It consists of a door that is openable and closably supported at the opening of a heating chamber that houses a display section, a main control section, and a contact section.

Effect The heating device of the present invention connects the main control part in the door and the heating means in the main body by a contact piece and a conductive piece that are electrically connected only when the door is closed, without using a cable or the like.
When the door is opened, this connection is released, and the battery or capacitor inside the door continues to supply power to the main control unit.The set heating time limit, etc. is maintained without being lost even when the door is opened, and the power line There is no danger that the heating means will continue to operate due to contact between the control signal lines.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of the main body of a microwave oven showing an embodiment of the present invention. The main body 1 houses various controlled parts and a heating chamber 2. Its front opening is door 3
The door 3 is rotatably supported. The oven lever 4 is an operating piece for unlocking the door 3 and opening the door.
The door key 5 engages the body and locks the door 3 in the closed position. Of course, it doesn't matter if it's a handle.

An operation panel 6 is embedded above the door 3. This operation panel 6 includes an operation piece 7 and a display section 8,
A user's heating command is input to the controller.
The controller is arranged on the back side of the operation panel 6, and is connected to a controlled part such as a magnetron on the main body 1 side by a connecting means. The contact window 9 is an opening provided in the main body for this purpose, and is provided with a conductive piece inside. A similar contact window is provided on the inside of the opposing door 3, and a contact piece is provided inside.

FIG. 2 is a cross section taken along line XX of such a heating device.
The operation panel 6 has a thin structure like a card calculator, and is attached to the position where the screen 10 is attached. The operation panel 6 includes a controller, and is connected to the controlled section 11 on the main body 1 side by a connecting means 12. The specific structure of this connecting means will be explained in detail with reference to FIG.

Now, the controlled part 11 is equipped with parts that are difficult to incorporate into the operation panel 6, such as a relay that controls the power supply to the magnetron 13, which is a heating means, a capacitor that cannot be made into chip parts, and a power transformer. In particular, the relay is large and requires a relatively large amount of power, so it was placed on the main body rather than built into the door. This allows the door to be configured compactly, and also prevents significant consumption of power from batteries and capacitors inside the door, which will be described later.

A rotary mounting table 14 is provided in the heating chamber 2 to improve uneven baking of the object to be heated 15. Reference numeral 16 denotes a motor serving as a driving source for this rotary mounting table 14.

Next, we will discuss the specific configuration example of the connection means in the third section.
This will be explained using figures. In this embodiment, pins and sockets were used as the connection means. A signal line 17 is drawn out from the back side of the operation panel 6 and guided through a shield sleeve 18. The shield sleeve 18 passes through the inside of the yoke 19 and prevents the signal line 17 from picking up microwave noise. 20 is a dielectric material such as plastic that closes the cheese yoke opening. A pin 21 as a contact piece is fixed to this dielectric 20,
Connected to signal line 17. On the other hand, a socket 22 serving as a conductive piece is arranged on the controlled part 11 on the main body side, and is fitted with the pin 21 when the door is closed. A shield sleeve is used as appropriate, and a shield wire also has an effect.

Now, the structural example of the present invention has been described above, and next, the circuit structure will be explained.

FIG. 4 is a circuit diagram showing one embodiment of the present invention. A controller 23 built into the operation panel includes a microcomputer 24 (hereinafter abbreviated as "microcomputer") as a main control section, and controls the entire system. The operation pieces 7 are arranged in a matrix and input various operation commands to the microcomputer 24. The display section 8 is, for example, a liquid crystal display, and is dynamically turned on by the microcomputer output Do-27.

This controller 23 is equipped with a battery 25 . This allows the controller 23 to operate even when the door is opened.
can operate independently of the main body. As this battery, a lithium battery as a primary battery or a NiCd battery as a secondary battery that is charged when the door is closed can be used. Of course, it may also be a solar cell.

Note that 26 is a clock oscillation circuit for a timer, whose frequency is appropriately divided within the microcomputer 24, and is used as a clock base for decrementing heating time, etc.

On the other hand, controlled parts and a DC power source are arranged in the controlled section 11 . The DC power supply 27 consists of a low-voltage transformer and a rectifier circuit, and supplies power to components that require relatively large amounts of power, such as relays and buzzers.

The main relay 28 functions as a time switch that remains on during cooking, and the power intermittent relay 29
functions as an output switching means that changes the average output of the magnetron periodically intermittently during cooking.
Of course, if output switching is not required, there is no need for a power intermittent relay. The buzzer 30 is used to notify the completion of cooking and the valid input of the operation piece 7.

Now, the controller 23 and the controlled part 11 are connected by the contact piece 21 and the conductive piece 22, which are connection means, when the door is closed. O ₂ , O ₃ , O ₄ are each buzzer 3
0, a signal that controls the power intermittent relay 29 and main relay 28. These signals are each connected to a contact piece 21, and contact a conductive piece 22 to which a corresponding controlled component is connected.

On the other hand, the signal _O5 is output from the microcomputer 24,
It is connected to the contact piece 31a. A contact piece 31b electrically separated from this is connected to the input terminal IN of the microcomputer 24. A shorting piece 32 is provided on the main body side at a position corresponding to the pair of contact pieces 31.
will be provided. With this configuration, when the door is opened,
No signal is input to the IN input, and the output is O ₅ when the door is closed.
is shorted and input. Therefore, it is possible to detect whether the door is opened or closed. The contact piece 31a may be connected to a +5V potential or the like. As described above, according to this embodiment, the opening and closing of the door can be detected without using the conventional microswitch.

Next, another embodiment of the present invention will be described with reference to FIG. There are three major differences between this embodiment and the previous embodiment (FIG. 4).

First of all, the method of detecting door opening/closing is different. In the previous example, a shorting piece 32 was provided on the main body side, but in this example, it is replaced with a conductive piece 33, which is connected to a pulse power source. Therefore, the controller 23 receives a pulse signal from this pulse power source when the door is closed, and the IN input has no signal when the door is opened. Therefore, opening and closing of the door can be detected. Note that the conductive piece 33 is +
It may also be connected to a 5V potential.

The second pulse power source is formed by a clock pulse circuit 34 that rectifies the AC commercial power source. Therefore, the microcomputer 24 can decrement the timer by counting the clock pulses when the door is closed. Yotsute controller 23
No clock oscillator is required on top. Since the clock pulse does not come when the door is opened, the timer's daily increment is automatically stopped. In addition, a failure in the clock circuit is handled in the same way as a door opening operation, and safety can be maintained without any special software considerations for the microcomputer 24.

Third, a capacitor 35 is installed in the controller 23 in place of the battery 25, and power supply voltage is supplied through a contact piece 36 and a conductive piece 37.

The capacitor 39 is charged when the door is closed, and supplies power to the controller 27 instead of the battery when the door is opened.

Effects of the Invention As described above, the heating device of the present invention has the following effects. First, since the controller and the main body can be connected without a cable, there is no need to disconnect the cable due to opening and closing of the door, dramatically extending the service life. Second, the controller and the main body can be connected over the shortest distance, and are much less susceptible to noise caused by microwaves, etc., than in the conventional example in which the cable detours around the hinge. Thirdly, in conventional cable connections, the control line and power line may come into contact due to disconnection.
Since there is no cable in the present invention, such crosstalk is not possible, whereas there is a risk that the relay may become stuck on. Fourthly, since the controller is equipped with a battery or a capacitor, even after the heating time limit is set, the set time limit, etc. is maintained without being lost even if the door is opened. Additionally, since relays that require large amounts of power are placed on the main body side, the power consumption of batteries and capacitors can be kept to a minimum. Furthermore, even if a power outage occurs, the controller continues to operate without any problems. Since such an abnormality on the main body side can be detected by an abnormality in the door signal or clock signal, it is possible to interrupt cooking if it is in progress, and the cooking can be restarted automatically after the failure is recovered, greatly increasing safety. Fifth, when the door is opened, the relay is placed on the main body side, so it is forcibly turned off and the microwave oscillation is stopped, making it safe.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the main body of a heating device showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line XX of the same, and FIG. 3 is a sectional view of essential parts showing a specific example of the configuration of the contact means. FIG. 4 is a circuit diagram showing one embodiment of the circuit of the same device, and FIG. 5 is a circuit diagram showing another embodiment. 1...Main body, 2...Heating chamber, 3...Door, 6...
...Operation panel, 7...Operation piece, 11...Controlled part, 1
2... Connection means, 13... Heating means (magnetron), 15... Heated object, 21... Contact piece (pin), 22... Conductive piece (socket), 24... Main control unit.

Claims (1)

[Claims] 1. A heating chamber in which an object to be heated is placed, a heating means coupled to this heating chamber, a relay that controls power supply to this heating means, a conductive piece connected to the operating coil of the relay, and A main body containing a chamber, a heating means, a relay, a conductive piece, etc., an operation piece for setting the heating time limit, etc., a display section for displaying the set heating time limit, etc., and an operation panel including these operation pieces and the display section. a main control unit that decodes the signal input from the operation piece and displays it on the display unit and controls power supply to the heating means; and a contact piece connected to the signal line output from the main control unit. and a door supported to be openable and closable at the opening of a heating chamber containing these operation pieces, a display part, a main control part, and a contact piece, and the main control part can be opened and closed by the contact piece and the conduction piece. The device is electrically connected to the heating means via the relay when the door is opened, and the electrical connection is disconnected when the door is opened, and the operation panel has a built-in capacitor connected to a battery or a power supply line. , a heating device configured to supply power to the main control unit by the battery or a capacitor connected to the power supply line at least when the door is opened.