JPH0247370Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Purpose of the invention (field of industrial application) This invention relates to an improvement of a cooking start switch for a microwave oven.

(Prior Art) In a microwave oven, it is dangerous if electromagnetic waves for cooking flow when the door is opened, so a safety device is provided in the double structure. One is the door switch, which is generally turned off when the door opens.
The other was a relay switch consisting of a monitor relay that was energized when the door switch was closed due to a failure, and a relay contact corresponding to the monitor relay.

However, the cost of the other relay switch is very high, and there has been a desire for a switch that is low in cost and has a structure that reliably performs its safety function.

(Problems to be solved by the invention) This invention was made in view of the above points, and provides a cooking start switch that is low in cost and has excellent safety performance and incorporates a microwave oven safety device in a simple configuration. It is something to do.

(b) Structure of the invention In this invention, the cooking start switch is composed of three contact elements, one of which is a safety device, and has two contacts.The more detailed structure is that of the cooking button. This is a cooking start switch for a microwave oven that is linked to the operation, and has a first contact element that moves back and forth in conjunction with the operation of the cooking button, and when the first contact element moves in one direction based on the ON operation of the cooking button. a second contact element whose one end is connected to the first contact element; a third contact element which is connected to the other end of the second contact element; and an elastic member configured to constantly connect the second contact element to the third contact element. At the same time, the first contact element is welded to the second contact element, and the first contact element is attached to the cooking button.
A control means for the second contact element that functions to prevent the second contact element from being connected to the third contact element again in a state in which the second contact element is disconnected from the third contact element due to an operation of moving in the other direction based on the OFF operation. This is a cooking start switch for a microwave oven.

(Example) First, prior to explaining the cooking start switch of this invention, the configuration of a microwave oven using the cooking start switch of this invention will be briefly explained with reference to FIG.

The microwave oven 1 has a heating chamber 2 inside, and a door 3 is attached to the front surface of the heating chamber 2. Reference numeral 4 denotes an operation panel, which has two cooking tips 5 provided at the top, and upper and lower cooking buttons 6 and a door opening button 7 provided at the bottom.

Figure 2 shows the circuit configuration, where 8 is an electromagnetic wave generating section;
9 is a timer, 10 is a contact corresponding to the timer 9, 11 is a fan motor, and a door switch 13 and a cooking start switch 14 are arranged in series between a power source 12 and an electromagnetic wave generating section 8. In this configuration, electromagnetic waves are not generated from the electromagnetic wave generating section 8 unless both the door switch 13 and the cooking start switch 14 are turned on.

The structure and operation of the cooking start switch of this invention will be explained below with reference to FIGS. 3A, B to 5A, B.

The cooking start switch 14 is provided at the rear of the cooking button 6, and is divided into two parts, which are integrated with the operating plate 15 of the cooking button 6 from the front and perform reciprocating motion in conjunction with the operation of the cooking button 6. the first contact element 16 and the first contact element 16 of the cooking button;
Two second contacts whose one end connects to the first contact element when moved in the direction of arrow A based on the ON operation.
It consists of a contact element 17 and a third contact element 18 connected to the other end of the second contact element 17.

The second contact element 17 integrally includes an operating body 19,
This operating body 19 is housed in a case 20.

And this case 20 has a spring body 21 and a ball 2.
Control means 23 for the second contact element 17 are provided. As shown in FIG. 3, the ball 22, which is biased by the spring body 21, normally
9 is elastically pressed and fixed, and the second contact element 17 and the third contact element 18 are maintained in a connected state.

In the state shown in Figure 3, the door is open and the lever 24 is
The cooking button 6 cannot be pushed in due to the presence of the button. When the door 3 is closed, the lever 24 rotates in conjunction with the door 3, allowing the cooking button 6 to be pressed as shown in FIG. 4, and cooking begins. When the cooking button 6 is pushed in, the lever 25 engages with a portion of the operating plate 15 as shown in FIG. 4, and the pushed state is maintained. Then, with the cooking button 6 pressed in, the first contact element 16 moves rearward and connects to the second contact element 17.

Since the second contact element 17 and the third contact element 18 are always kept in a connected state, when the cooking button 6 is pushed in, the first, second, and third contact elements
The contact elements are connected, and the entire cooking start switch 14 is turned on. The configuration of the second contact element 17 and the third contact element 18 described above constitutes a safety device.

When the door opening button 7 is pressed after cooking is completed, the lever 25 moves and normally the first contact element 16 and the second contact element 17 are separated as shown in FIG. However, if a large current flows during cooking, the first contact element 16 and the second contact element 17 will be welded together as shown in FIG. At this time, the second contact element 17 is pulled out from the third contact element 18.
and disconnect it. Then, the ball 23 pushed by the spring body 21 fits into the space where the pressed part 26 by the ball 22 of the operating body 19 in the case 20 is located, and the operating body 19 cannot return to its original position. Therefore, even if you try to push the cooking button 6 again with the door 3 closed, the operating body 19 of the third contact element 18 will come into contact with the ball 22 and you will not be able to push it in. Connection with three contact elements 18 is blocked.

In order to restore the normal state, it is sufficient to inspect the circuit, remove the welding between the first contact element 16 and the second contact element 17, and then push the ball 22 further to return the operating body 19 to its original position.

(c) Effects of the invention This invention is constructed as described above, and is a cooking start switch that has a simple structure and is integrated with a safety device that operates reliably. If used, a microwave oven with low production costs and excellent safety performance can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the external appearance of a microwave oven using this invention, Fig. 2 is an embodiment circuit diagram, and Figs. 3A, B to 5A, B are respective cooking start switches of this invention. FIG. 7 is a vertical cross-sectional view and a corresponding plan view showing different states. 6... Cooking button, 14... Cooking start switch, 16... First contact element, 17... Second contact element, 18... Third contact element, 23... Control means.

Claims (1)

[Scope of utility model registration request] This is a cooking start switch for a microwave oven that is linked to the operation of the cooking button, and includes a first contact element that moves back and forth in conjunction with the operation of the cooking button, and a first contact element that moves in one direction based on the ON operation of the cooking button. A second contact element whose one end connects to the first contact element when moved, a third contact element which connects to the other end of the second contact element, and the second contact element is constantly connected to the third contact element. The first contact element is welded to the second contact element, and as the first contact element moves in the other direction based on the OFF operation of the cooking button, the second contact element moves to the third A second element that functions to prevent connection from being made again in a state where the connection with the contact element is released.
A cooking start switch for a microwave oven comprising a contact element control means.