JPH0480294B2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a high frequency heating device,
To provide a door switch safety device for a high-frequency heating device that is inexpensive, has excellent durability, and is highly mass-producible.

Conventional Structure and Problems Conventionally, as shown in FIG. 1, when the door 1 is closed, a door key 3 is attached to the door 1 and pulled downward by a spring 2, and a lever is attached to the hook 4. By pushing downward a metal lever 6 supported by a shaft 5, an actuator 9 of a micro switch 8 fixed to a frame 7 with machine screws 10 is pushed and the micro switch 8 is operated. Therefore, since it is composed of several parts, it causes problems of malfunction. In addition, the lever 6 is a rigid body made of sheet metal, and because it has little cushioning properties, the impact force of closing the door 1 is directly applied to the micro switch 8, and the actuator 9 of the micro switch 8, contact springs, etc. are damaged or worn, resulting in operating force. There was a problem that the life of the micro switch 8 was shortened, such as by causing significant changes.

In addition, in the control circuit shown in FIG. 2, as one of the safety devices for the power transformer 11 that forms the oscillation circuit of the high-frequency heating device, a micro switch 1 is used which is linked to the opening and closing of the door 1 at the front of the heating chamber through which objects to be heated are taken in and taken out.
2, 13, and micro switch A12, B13
When the door malfunctions due to welding of the contacts and is fired, a micro switch 8 that is turned on when the door opens is provided before supplying power to the power transformer 11 that generates radio waves, and the micro switches 8, 12, 1
3 and fuse 14, which forms the short circuit, are turned off (OFF) and no radio waves are emitted.

Therefore, there are at least three micro switches 8, 12, and 13 that are linked to the opening and closing of the door, and if the micro switch 8 is operated by the door key 3 as shown in Figure 1, the state shown in Figure 1 will occur. Three items are required. Therefore, each of them had the problem of shortening the life of the microswitch 8 as described above.

Next, examples shown in FIGS. 3 to 6 have been put into practical use as improved versions of the above.

FIG. 3 is a diagram showing the door 1 closed and the lever 6 pressed by the door key 3 to turn on the switch 8.

In FIG. 3, the switch fixing part 1 fixes the hook 4, lever 6, and micro switch 8.
1 is integrally molded with resin, and a micro switch 8 is fitted into it. The lever 6 uses the support part A as a fulcrum, pushes the actuator 9 of the micro switch 8 with the switch operation part B, and presses the actuator 9 of the micro switch 8.
The door key 3 is pressed by the door key 3. This results in
The door key 3 requires about 70% of the load required to operate the micro switch 8, making it easy to operate.

When an attempt is made to open the door 1, the door key 3 moves upward as indicated by the dotted line, the door 1 is released, the switch lever 6 becomes as indicated by the dotted line, and the switch 8 is turned off. Next, the shape of the switch lever 6 will be described. A thin section D is formed near the fulcrum A section, and a bent section E is formed.
When the lever head C comes into contact with the door key 3,
It branches into an operating section C that pushes the actuator 9 of the micro switch 8. Therefore, the movement of the door key 3 is transmitted to a certain extent, but if the door key 3 is pushed beyond a certain amount of movement, there is a bent part on the side of the head lever C near the branching point G, so the lever on the head C will move further. As a result, the actuator 9 receives less impact and the durability of the micro switch is improved.

In addition, since the thin wall portion is provided in areas other than the vicinity of the fulcrum A, the amount of movement of the thin wall portion D near the fulcrum A is also small.
In addition, the thin wall portion H is also reduced. This made it possible to significantly improve the repeated flexibility of the resin lever 6 when opening and closing the door 1. Also, both thin parts D and H
By providing this, the durability, restorability, and creep characteristics of the switch lever 6 itself are improved.

FIG. 4 shows an external perspective view with only the switch lever 6 removed.

Next, the other micro switch 12 will be described.

In FIG. 3, the switch fixing part 15 that fixes the hook 4 and the micro switch 12, and the pivot axis 17 of the hook spacer 16 are integrally molded with resin, and the micro switch 12 is fitted into the switch fixing part 15. It is composed of

When the hook spacer 16 is inserted as shown by the arrow in FIG.
The L-shaped protrusion 18 of the rotation center shaft 17 will fall inward as shown by the dotted line, and when pushed further, the hook spacer 16 will be engaged with the L-shaped protrusion 18 as shown in FIG. 6, and will not fall off. ing.

When the entire unit shown in FIG. 6 is fixed to the main body, it is fixed to the main body at two places: the integrally formed boss and the rotation center shaft 17. Therefore, due to the advantages that the main body and the door 1, the door key 3 and the hook 4, and the door key 3 and the hook spacer 16 are each integrally molded, and the rotation center shaft 17 also serves as a boss for fixing the main body, the dimensions are stably fixed. It can be done. However, there are limits to further simplifying the current simplified safety equipment.

OBJECT OF THE INVENTION The present invention overcomes the above-mentioned conventional drawbacks.
The purpose is to create a safety device with a configuration that is highly suitable for mass production and to improve its durability.

Structure of the Invention In order to achieve the above object (l), the present invention has the following structure.

That is, a heating chamber for heating food, a high-frequency power source for supplying high-frequency output to the heating chamber, a door provided in the front opening of the heating chamber so as to be openable and closable, and a plurality of door keys provided on the door. a plurality of switch levers operated by the plurality of door keys; a plurality of hook parts with which the plurality of door keys removably engage; a plurality of switches that turn on and off the high frequency power source; The switch levers, the hook parts, and the switch fixing parts are integrally molded from resin. In this configuration, the plurality of switches include at least two switches that are turned on and off by the plurality of switch levers to open and close the main circuit of the high frequency power source, and at least two switches that are turned on when the door is opened to open and close the main circuit. The switch lever is configured to include at least one switch that turns off the power supply to the high-frequency power source when an abnormality such as contact welding occurs, and the switch lever is connected to the vicinity of its fulcrum and the door key. A thin wall portion is provided between the head for operating the door key and the switch operating section, and at least one switch lever is configured to branch into a head that connects to the door key and an operating section for operating the switch.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 7 shows that the door 21 is closed and the door keys 22, 2 are closed.
3, the levers 24, 25, 26 are pushed and the switches 8, 12, 13 are turned on.

In FIG. 8, levers 24, 25, 26,
Micro switches 8, 12, and 13 are fixed. The switch fixing parts 27, 28, 29, hooks 30, 31, etc. are integrally molded with resin, and the micro switches 8, 12, 13 are fitted into the switch fixing parts 27, 28, 29, hooks 30, 31, and the like.

The lever A24 has a shape in which the support part A is used as a fulcrum, the switch operating part B pushes the actuator of the micro switch 8, and the head part C is pushed by the door key 22. As a result, the door key 22 only requires about 70% of the load required to operate the micro switch 8, making operation easier.

On the other hand, the lever B25 uses the support part J as a fulcrum, and the switch operating part K operates the micro switch 12.
Press the actuator and press the L part of the head with door key 2.
2 to press the shape. As a result, the door key 22
The load required to operate the micro switch 12 is about 70%, making operation easier. Further, the distance (l) from the fulcrum position of the lever B25 to the point pressed by the door key 22 is longer than the distance (m) from the actuator to the fulcrum. In addition, the lever 25 is provided with thin parts P and Q near the fulcrum part J and between the head L part and the switch operation part K, respectively, to improve the restorability of the lever 25 and to It also improves the impact force buffering effect and the creep characteristics of the lever itself.

Next, the lever C26 uses the supporting part R as a fulcrum, and the micro switch 13 is activated by the switch operating part S.
Press the actuator and insert the head T into the door key 2.
3 to press the shape. As a result, the door key 23
The load required to operate the micro switch 13 is approximately 70%, making the operation easier. Further, the distance from the fulcrum position of the lever C26 to the point pressed by the door key 23 is longer than the distance between the actuator and the fulcrum.

In addition, the lever C26 is provided with thin parts U and W near the fulcrum part R and between the head T part and the switch operation part S, respectively, to improve the restorability and creep characteristics of the lever 26. Micro switch 13
It also has a good buffering effect on impact forces.

When an attempt is made to open the door 21, the door keys 22, 23 move upward as shown by the dotted lines, the door 21 is moved away, the levers 24, 25, 26 move as shown by the dotted lines, and the switches 8, 12, 13 are turned off.

FIG. 8 shows a perspective view of the levers 24, 25, and 26 taken out.

When fixing the entire unit to the main body as shown in Figure 9,
Bosses 32 and 33 that are integrally molded are fixed to the main body. Therefore, the main body, door 21, door key 22,
The dimensions of 23, hooks 30, 31, door keys 22, 23, and levers 24, 25, 26 are stably fixed.

As mentioned above, the hook, multiple levers, multiple switch fixing parts, mounting bosses, etc. are integrally molded with resin, and the structure in which the switches 8, 12, and 13 are fitted allows for a simple structure and simple assembly work. With reliable operation,
Moreover, it has the effect of making it possible to provide a safety device that is inexpensive and has good durability.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) The switch lever has a thin wall section, which has an extremely good buffering effect, and since the impact force when the door is closed is not applied directly to the switch, the switch actuator can prevent damage to the contact springs, etc. Since the wear of the microswitch is also significantly reduced, there are fewer changes in the operating force of the microswitch, and its durability is improved.

(2) Since the number of component parts is only an integrally molded product and multiple switches, workability is extremely improved and mass production is highly possible.

(3) Since multiple switch levers, multiple hook parts, and multiple switch fixing parts are integrally molded with resin, dimensional stability is improved, such as completing the assembly by fitting the switches without adjusting the design dimensions. It is easy to assemble and can be mass-produced.

[Brief explanation of drawings]

Fig. 1 is a partially sectional side view showing a safety device of a conventional high-frequency heating device, Fig. 2 is a schematic control circuit diagram of the conventional safety device, and Fig. 3 is a safety device of another conventional high-frequency heating device. FIG. 4 is an external perspective view of the switch lever of the same device shown in FIG. 2, FIG. 5 is an explanatory cross-sectional view taken along the line X-X' in FIG. FIG. 7 is a partial sectional view showing a safety device of a high-frequency heating device according to an embodiment of the present invention, and FIG. 8 is a perspective view of the same device as shown in FIG. 8 according to an embodiment of the present invention. FIG. 9 is an external perspective view of the main part of the device shown in FIG. 7, which is an embodiment of the present invention. 8...Switch C (for short circuit), 12...
(Main circuit opening/closing) switch, 13... (main circuit opening/closing) switch, 11... Power transformer, 14...
fuse, 21...door, 22...door key, 2
3...Door key, 24...Lever, 25...Lever, 26...Lever, 27...Switch fixing part,
28...Switch fixing part, 29...Switch fixing part, 30...Hook, 31...Hook, 32...
Boss part, 33...Boss part.

Claims (1)

[Claims] 1. A heating chamber that accommodates food; a high-frequency power supply that supplies high-frequency output to the heating chamber; a door that can be opened and closed at the front opening of the heating chamber; a plurality of door keys provided on the door; a plurality of switch levers operated by a plurality of door keys; a plurality of hook portions with which the plurality of door keys removably engage; and a main circuit of the high frequency power source that is turned on and off by the plurality of switch levers; at least two switches that open and close the switch, and at least one switch that turns on when the door is opened and turns off the power supply that supplies power to the high-frequency power source when the main circuit open/close switch has an abnormality such as contact welding. and a plurality of switch fixing parts for fixing the plurality of switches, the plurality of switch levers, the plurality of hook parts, and the plurality of switch fixing parts are integrally molded with resin, The switch lever has a thin section near its fulcrum and between the head that connects to the door key and the switch operating section, and at least one switch lever has a thin wall section between the head that connects to the door key and the switch operating section. The high-frequency heating device has a configuration that branches into an operating section and an operating section.