JPH0531446Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a door opening device for a microwave oven. This invention relates to an automatic door opening device in which a worm gear and worm are installed, and a door is automatically opened by lightly touching a soft touch push button attached to a front panel.

[Conventional technology]

The conventional door opening device, as shown in Figure 4,
A latch 21 is fixed to the door 20, and a rotary plate 26 having a hook 24 and a protruding rod 25 is rotatably installed on a support plate 23 fixed inside the microwave main body 22. A coil spring 27 is connected to the rotary plate 26 to resiliently support the rotating plate 26 in the counterclockwise direction. Further, a lift lever 28 is installed on the support plate 23 so as to be movable up and down, and a coil spring 29 is connected to the lift lever 28 and the support plate 23 to elastically support the lift lever 28 upward. ing. A locking surface 31 is formed at the upper end of the lift lever 28 to lock a rotation stop pin 30 fixed to the rotary plate 26 to restrict counterclockwise rotation of the rotary plate 26. An operating lever 32 is rotatably installed on a shaft 33 on the lower side of the lever 28, one end 32a of which presses a lifting stop pin 34 fixed to an intermediate portion of the lifting lever 28, and the other end The end portion 32b is in contact with an operating rod 37 of a push button 36 installed on the front panel 35 of the microwave main body 22. In the figure, 23a is a hole bored in the support plate 23, and 38 is a micro switch for controlling range operation which is activated as the operating surface 38' is pushed by the protruding rod 25 of the rotary plate 26.

As shown in FIG. 4, the conventional opening/closing device configured in this way opens and closes the door 20 when it is closed.
When the push button 36 is pressed, the operating lever 32 is rotated counterclockwise, and the lifting stop pin 34 of the lifting lever 28 is pushed, so that the rotation stopping pin 30 of the rotary plate 26 is released from the locking surface 31 of the lifting lever 28. The rotating plate 26 is rotated counterclockwise by the elasticity of the coil spring 27, and the latch 21 is unlocked, so that when the door knob is pulled, the door is released.

[The problem that the idea aims to solve]

However, such conventional door opening/closing devices have a complicated structure that requires a large number of parts, which increases manufacturing costs. The rotation stop pin 30 of the rotary plate 26 is latched onto the latching surface 31 of the lift lever 28 to maintain the locked state, so when an impact is applied to the range main body 22, the latch 2
There were concerns that the lock status of 1 could be released without permission. Furthermore, when the door 20 is closed, the stop pin 30 of the rotary plate 26 is engaged with the locking surface 31 of the elevating lever 28, and the latch 21 of the door 20 is engaged with the hook 24 of the rotary plate 26 while rotation is restricted. Since the door 20 is latched onto and locked, the door 20 is no longer in close contact with the microwave main body 22, and leakage of radio waves is not completely blocked. This poses an inconvenient problem as the door 20 must be opened by pulling the knob after the door is unlocked.

The present invention was devised to solve these drawbacks of the conventional technology, and its purpose is to release the locked state of the door hook by an electric signal instead of manual operation using a motor, worm, and worm gear. An object of the present invention is to provide an automatic door opening device capable of automatically opening a door.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an automatic door opening device for a microwave oven configured such that the door is opened and closed by the interaction of a latch fixed to the door and a latch piece fixed to the main body. , a contact portion is formed at the tip of the latch so as to protrude forward, a worm gear is disposed within the main body adjacent to the contact portion, and a wheel integrated with the worm gear is provided on one side of the worm gear. , one or more protrusions are formed on the side surface of the wheel for contacting and raising the abutting portion of the latch, and the outer circumferential surface of the wheel is provided with a bent portion of the secondary switch. one or more engaging grooves are provided;
Provided is an automatic door opening device for a microwave oven, characterized in that a worm drive motor is configured by connecting in parallel a primary switch that can be operated from outside the main body and a secondary switch that is operated by the wheel. do.

The primary switch is a soft-touch push button switch that operates to start the worm drive motor when the door is opened;
The secondary switch operates to rotate the wheel to open the door after the worm drive motor is started, and is comprised of an elastic plate switch that contacts the outer periphery of the wheel and the groove. This is convenient.

[Action]

When you turn on the primary switch to open the microwave door, the worm drive motor starts and drives the worm. After the motor starts, the primary switch is turned off, but the worm gear driven by the worm rotates and the wheel moves.
The bent part of the secondary switch that was engaged with the groove of the wheel comes off the groove and comes into contact with the outer periphery of the wheel, turning the secondary switch ON, and for this reason, the motor continues to run even after starting. Continue to rotate and rotate the wheel. At this time, the abutting part at the tip of the latch comes into contact with the protrusion on the side of the wheel and is pushed up, which causes the latch to disengage from the locking piece that had previously been used to close the door. door will be opened. When the wheel rotates further after the door is opened, the bent portion of the secondary switch engages with the concave groove of the wheel at the next position, turning the secondary switch OFF and stopping the rotation of the motor. When the door is closed, the latch engages with the locking piece again, and both the primary and secondary switches are closed.
It returns to the OFF state and waits for the next door to be opened.

〔Example〕

As shown in FIGS. 1 to 3, the shaft pin 2 fixed to the door 1 of the microwave oven has a locking step 3a.
A latch 3 having a tip end thereof is rotatably installed, and both ends of a coil spring 4 are fixed to a spring hook 3b protruding from the middle portion of the latch 3 and a spring hook 1b fixed to the door 1. A latching piece 7 is fixed to the inner surface of the front plate 6 of the microwave oven main body 5, to which the latching step 3a of the latch 3 is latched. A contact portion 3c is integrally formed at the upper end of the latch 3, and the microwave oven main body 5
On the inner surface of the front plate 6 is a bent end 8 on one side of the support plate 8.
A is fixed, and a shaft 9 is attached to the support plate 8. The shaft 9 has one or more abutting portions 3 on one side.
c. A wheel 12 is rotatably installed, on which a rising operating protrusion 10a is formed, one or more grooves 10b for switch operation are formed on the outer peripheral surface, and a worm gear 11 is integrally formed on the other side. ,
A one-way drive motor 14 having a worm 13 for driving the worm gear 11 is fixedly installed on the support plate 8, and a soft-touch push button switch 15, which is a primary switch, is exposed to the outside on the front plate 6 of the main body 5. fix the wheel 12
By fixing an elastic plate switch 16, which is a secondary switch, to one side support plate 8 of wheel 1
When inserted into the groove 10b of No. 2, the movable terminal 16' is connected to the fixed terminal 16''.
The drive motor 14 is operated by connecting the secondary switches 15 and 16 in parallel.

In the drawing, an unexplained reference numeral 17 is a safety switch that operates and shuts off the magnetron.

The operating state and effects of the present invention constructed as described above will be described in detail as follows.

In the state shown in FIG. 1A, when the user lightly touches the external operation primary switch, that is, the push button switch 15 attached to the front panel of the microwave oven in order to open the door 1, the The switch 15 is momentarily turned on and turned off again, and the drive motor 14 momentarily rotates, causing the worm 13 and worm gear 11 to rotate. Then, the wheel 12 formed integrally with the worm gear 11 instantly rotates at a certain angle, and the wheel 12
Secondary switch 1 inserted into groove 10b of
The protrusion 16'a of No. 6 is removed from the groove 10b.

The primary switch 15 and secondary switch 16 are connected in parallel to the drive motor 14, as shown in FIG. 1B.

When the protrusion 16'a of the secondary switch 16 is removed, the secondary switch 16 is removed as shown in FIG. 2A.
The movable terminal 16' is pushed downward and the fixed terminal 1
6'' and is turned on, the drive motor 14 is not stopped and can continue to rotate even if the primary switch 15 is turned off.

As the drive motor 14 continues to rotate in this manner, as shown in FIG. As shown in Fig. B, when the actuating protrusion 10a protruding from the wheel 12 comes into contact with the abutting portion 3c of the latch 3 and is pushed up to the top dead center by the rotation corner force and released from the latch piece 7, the lock is released. Microwave oven door 1 to release the condition
will be able to open up. Once this operation is completed, the wheel 12 or drive motor 14
When it is no longer necessary to operate the secondary switch 16 any more, the protrusion 16'a at the end of the secondary switch 16 is inserted into the next groove 10b, as shown in FIG. 2C, and the secondary switch 16 is turned off. Therefore, both the primary and secondary switches 15 and 16 are turned off, and the next door opening waiting state is entered.

[Effect of idea]

By implementing the present invention, the following effects can be achieved.

(1) The door opens automatically by lightly touching the soft-touch push button on the door, which has the advantage of making it easy to open and close the door.

(2) Even if a shock is applied to the microwave oven body, the latch is securely locked, so there is no risk of the door being unlocked or opening the closed door without permission.

(3) When the door is closed, the door and the oven body come into close contact, completely blocking power leakage.

(4) It has a relatively simple configuration and is advantageous in terms of cost.

[Brief explanation of the drawing]

[FIG. 1] The automatic door opening device according to the present invention is shown, FIG. 1A is a diagram of its installation, and FIG. 1B is a wiring diagram between a switch and a motor. [FIG. 2] The main parts of the present invention are shown in operation state. FIG. 2A is a diagram of the door closed state, B is a state diagram immediately before the door is opened, and C is a diagram of the door open state. [FIG. 3] It is a sectional view of the main part of the present invention. [FIG. 4] A cross-sectional view showing the configuration of a conventional device. Explanation of symbols, 1...Door, 3...Latch, 3c
...Abutment part, 7...Latching piece, 10a...Protrusion part,
10b...concave groove, 11...worm gear, 12...
...Wheel, 14...Motor, 15...Primary switch, 16...Secondary switch.

Claims (1)

[Claims for Utility Model Registration] 1. Automatic door opening device for a microwave oven configured such that the door 1 is opened and closed by the interaction between a latch 3 fixed to the door 1 and a latch piece 7 fixed to the main body 5. A contact portion 3c is formed at the tip of the latch 3 to protrude forward, and a worm gear 11 is disposed within the main body 5 adjacent to the contact portion 3c. Wheel 1 integrated with the worm gear 11
2, one or more protrusions 10a are formed on the side surface of the wheel 12 for contacting and raising the contact portion 3c of the latch 3, and the outer peripheral surface of the wheel 12 is provided with a secondary The worm drive motor 14 includes a primary switch 15 that can be actuated from the outside of the main body 5 and a two-way switch that is actuated by the wheel 12. An automatic door opening device for a microwave oven, characterized in that the next switch 16 is connected in parallel. 2 When the door 1 is opened, the primary switch 15
is operated to start the worm drive motor 14, and after the motor 14 is started,
The secondary switch 16 is composed of a soft-touch push button switch that turns OFF, and the secondary switch 16 turns OFF after the worm drive motor 14 is started.
When the bent portion of the secondary switch 16 comes off the groove 10b and comes into contact with the outer periphery of the wheel 12, the secondary switch 16 is turned on.
Subsequently, the wheel 12 is rotated to open the door 1, and when the wheel 12 is further rotated after the door 1 is opened, the second
The outer periphery of the wheel 12 is configured such that the bent portion of the secondary switch 16 engages with the concave groove 10b of the wheel 12 at the next position, turning the secondary switch 16 OFF and stopping the rotation of the motor 14. 2. The automatic door opening device for a microwave oven according to claim 1, further comprising an elastic plate switch that contacts the groove 10b. 3. When the door 1 is closed, the latch 3 is latched to the latching piece 7, and the primary switch 15 and the secondary switch 16 are both returned to the OFF state. Automatic door opening device for the microwave oven described.