JPH03170728A - Oven range - Google Patents

Abstract

PURPOSE:To improve safety during a self-cleaning operation by constructing a switch group in the shape of a matrix, by disposing a start key and a stop key for some prescribed output port of a microcomputer and by disposing a stop key and a self-cleaning key for some prescribed input port. CONSTITUTION:A switch group 1 is so constructed as to be shaped in a matrix and a start key and a stop key are disposed for some prescribed output port D0 of a microcomputer 2, while a stop key and a self-cleaning(SC) key are disposed for some prescribed input port 12. All are set on the safe side when each port of the microcomputer 2 turns faulty. Accordingly, judgement of being critical is made on the UL standard ds well and such disadvantages that a demonstration test (DTM) is needed, that acquisition of the UL standard requires a very long term and that much cost is required are removed. According to this constitution, a self-cleaning operation can be executed safely.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a microwave oven equipped with a self-cleaning function. Conventional Technology In recent years, equipment products such as built-in ranges have been rapidly increasing, especially in the American market. Most built-in ovens have a self-cleaning function that raises the temperature inside the oven to about 500°C to burn off the oil. In addition, conventionally, many of the operating parts of microwave ovens were mechanical (mechanical type).
In recent years, electronic devices using a keyboard and controlled by a microcomputer have become mainstream. Problems to be Solved by the Invention The self-cleaning function is extremely dangerous because the temperature inside the refrigerator reaches approximately 500°C. In particular, due to the high temperature inside the refrigerator, there is a lack of oxygen inside the refrigerator, and if the door is opened under such conditions, an explosion may occur. Additionally, there is a possibility that carbon monoxide (CO) may be generated from inside the refrigerator due to component failure. In particular, in recent years, electronic control has become important on roads.
There have also been cases where the self-cleaning operation cannot be stopped when the microcomputer fails. Figure 4 shows a conventional key input circuit from switch group 1. The switch group 1 is arranged in a matrix. 2 is a control unit (i.e. microcomputer), and
D3 is the output port of the microcomputer, IO~■3 is the input port of the microcomputer, START means the start key, and RESET/STOP means the stop key. SC is a self-cleaning (hereinafter abbreviated as SC) key. Figure 5 is a timing flowchart for key capture. A time-sharing pulse is output from the output port DO-D3. ) key is pressed, a signal is input to the input port (TO) with a timing synchronized with the output port (DI), and the microcomputer determines that the SC key has been pressed.However, if the microcomputer is malfunctioning, for example, output port D3 is open. If this occurs, the stop key will no longer be accepted and the problem will occur that the SC will not be able to stop during operation.UL858A was established as a standard for such electronic control.This regulation is designed to take safety into consideration. This means that a short circuit/open in one case of an electronic component must not result in a dangerous condition.If a dangerous condition occurs, the component must be tested (i.e., DTM...D
emonstrate Test Method
) must match. This test is very time consuming and expensive.

FIG. 6 is a flowchart for determining safety by a seat/oven test regarding SC.

In this item, "2-operation ON, 1-operation OFF function (i.e., when you press the SC key and the START key, the
C works, and if you press the stop key, ゜SC will stop.
If this function disappears, it will be dangerous (Critic
al: Critical) and must undergo a demonstration test. FIGS. 7 and 8 are flowcharts showing what happens when a conventional circuit is subjected to a convenient seat/oven operation. Judging from this, there will be a very dangerous situation in which the stop key will not be accepted even when the microcomputer outputs D3 oven and the microcomputer is manually operated. Therefore, even in the UL standard, it is judged to be critical, and a demonstration test (DTM) is required, so it takes a very long time to obtain the UL standard, and it also costs a lot of money. This is a very big problem. Means for Solving Film In order to solve the above problems, the microwave oven of the present invention has the following features:
An oven equipped with a self-cleaning function, which is equipped with a group of switches such as a self-cleaning key and a stop key, and a control unit that determines information from the switch group using a plurality of output ports and a plurality of input ports. In the range, the switch group is arranged in a matrix, a time-division pulse train is generated from the plurality of output ports, and it is determined whether a switch in the switch group is pressed based on the presence or absence of a signal from the plurality of input ports. It has a horizontal switch group in which a start key and a stop key are arranged at the predetermined output port, and a stop key and a self-cleaning key are arranged at the predetermined input port. Function The microwave oven equipped with the self-cleaning function of the present invention has a group of switches arranged in a matrix,
A start key and a stop key are placed at a certain output port of the microcontroller, and a stop key and a self-cleaning key are placed at a certain input port. Be on the safe side. Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. 1st
The figure shows a circuit for capturing keys from switch group 1 of the present invention. 2 is a microcomputer, DO~D3 are output ports,
■0 to ■3 are input ports. Switch group 1 is configured in a matrix. Microcontroller output port DO
-D3 generates a pulse train in a time-division manner, and input port Do
-03 signal determines whether the microcontroller key has been pressed. Now, at a certain predetermined output baud}DO,
A start key and a stop key are arranged, and a stop key and a self-cleaning (SC) key are also arranged in a certain predetermined input port (2).

This will ensure that all ports on the microcontroller are safe from failure. Figure 2. Figure 3 is a flowchart showing what happens at each port of the microcontroller. First, if the output baud DO is an oven, the start key and stop key will not be accepted, so the SC will not operate and it is safe. Next, when using the output bow ID2 oven, the SC
Since the key is not accepted, it is safe without operating the SC. Next, when the input port IO is open, the start key is not accepted, so it is safe without SC operation. Finally, if the input port 2 is open, the SC key and stop key will not be accepted, so the SC will not operate and it is safe. Therefore, it is safe in all failure modes. Therefore, it passes the UL standard, UL858A.
Therefore, an electronically controlled microwave oven can be designed extremely safely. Furthermore, similar to the above example, the same effect can be obtained by arranging a stop key and an SC key in a certain predetermined output port, and arranging a stop key and a start key in a certain predetermined manual port.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained. (1) The safety during SC operation can be greatly improved and the quality can be improved by making an extremely easy change such as partially changing the key matrix. (2) It is now possible to pass the UL standard (UL858A), significantly shortening the acquisition period and greatly reducing costs. Figure 1 is a control circuit diagram showing an embodiment of the present invention, Figures 2 and 3 are Flowchart at the time of component failure, Figure 4 is the conventional control circuit diagram, Figure 5 is the key capture timing chart, Figure 6 is the timing chart for key capture.
The figure is a flowchart regarding SC of UL858A, No. 7
Figures 8 and 8 are flowcharts when parts fail. 1...Switch group, 2...Microconview evening.

Claims (1)

[Claims] Equipped with a self-cleaning function that includes a switch group consisting of a plurality of switches such as a self-cleaning key, a start key, and a to-kip key, and a control section that discriminates information from the switch group using a plurality of output ports and a plurality of input ports. In the microwave oven, the switch group is configured in a matrix, a time-division pulse train is generated from the plurality of output ports, and whether or not a switch in the switch group is pressed is determined based on the presence or absence of a signal from the plurality of input ports. The device is equipped with a self-cleaning function having a switch group configured to perform discrimination, a start key and a stop key are arranged at the certain predetermined output port, and a stop key and a self-cleaning key are arranged at the certain predetermined input port. Microwave oven.