JPS6326955Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an improvement of a turntable device for a high-frequency heating device.

[Technical background of the invention and its problems]

In microwave ovens (high-frequency heating devices), a turntable device is used as a measure to uniformly apply microwaves to the object to be heated, such as food, for good heating.

Conventionally, this type of turntable device was
As shown in FIG. 1, a gear motor f is installed on the bottom wall of a heating chamber a, independent of a fan motor e of a fan d that cools electrical components such as a magnetron b and a high voltage transformer c. f
A structure is used in which a rotating plate h in a heating chamber a is connected to an output shaft g of the rotating plate h using a gear motor f as a power source.
is being driven.

However, in addition to such a fan motor e for cooling, a gear motor f is provided separately, and the rotary plate h is
The structure for driving this has the disadvantage of being extremely expensive. Moreover, since the gear motor f includes a gear system and an electric part, it is heavy, and therefore the bottom wall of the heating chamber a is extremely susceptible to deformation. In particular, if an external force is applied to the microwave oven by dropping it during transportation, the bottom wall may be significantly deformed downward by the weight of the gear motor f, and if this deformation occurs, the electric field in the heating chamber a will Not only does this turbulence prevent stable microwave cooking, but in severe cases there is a risk of sparks. Furthermore, since the gear motor f has a large deceleration (the rotating plate h is about 8 to 10 rpm), the overall size inevitably increases, and the installation height l between the heating chamber a and the main body i needs to be wide. There is a problem with
This has become a key factor in making microwave oven products more compact.

Therefore, in recent years, a turntable device as shown in FIGS. 2 to 4 has been commercialized, which rotates a rotary plate h using the power of a fan motor e of a fan d for cooling electrical components.

That is, this turntable device has a small pulley k provided at the rear end of a fan motor e provided in the upper stage of a machine room j, and a shaft n connected to a large diameter pulley m on the bottom wall of a heating chamber a. A gear case p is rotatably supported and further includes a built-in worm gear mechanism o as shown in FIG. 4 at the lower stage of the machine room j. A large pulley r is provided at the end of the worm shaft q, and a small pulley t is provided at the end of the worm wheel shaft s. The small pulley t of the mechanism o and the pulley m connected to the rotary plate h are connected by a belt u, and as the fan motor e rotates, the small pulley k, belt u, large pulley r, worm gear mechanism o, and small pulley t, belt u, pulley m, and shaft n in order to rotate the rotary plate h.

However, in this structure in which the belt U is hung around the shaft n that receives the rotary plate h, the belt tension is applied to the heating chamber a through the bearing part v that supports the shaft n.
There is the disadvantage that the force constantly acts to deform the bottom wall of the tube as shown in FIG. For this reason, during cooking,
When the temperature of the inner bottom surface of the heating chamber a rises, the bottom wall deforms along with the applied force. If such deformation occurs, not only will the electric field in the heating chamber a be disturbed, making it impossible to perform stable cooking as mentioned earlier, but also the rotating plate h will be distorted due to the inclination θ of the shaft n.
Due to the inclination of the rotating plate h, the food w on the rotary plate h moves outward due to the centrifugal force, causing a problem that it collides with the side wall of the heating chamber a. Therefore, such 2
In a turntable device using book belts u, u, reinforcing plates x, x are attached to the bottom wall of the heating chamber a, but this increases the cost and is not very effective. In other words, even if it does not deform, as shown in Fig. 6, belt tension is constantly applied to the bearing part v in the thrust direction, so it tends to wear out on one side, and as a result, after long-term use, the shaft n tends to tilt as described above. The rotary plate h is tilted because of this.

Moreover, since the belt U is stretched horizontally, it is easily detached due to falling or vibration due to the influence of gravity, and due to the reduction ratio, the belt U is not placed against the bottom wall of the heating chamber A. It was necessary to tighten it tightly, and it was not easy to assemble.

In addition, the transmission efficiency of the system that uses two belts u and u to transmit the rotation of the fan motor e to the shaft n is not good, and since each pulley system is fixed to separate members, the shaft relative to the belts u and u There are also problems in that it is difficult to set the distance accurately and adjustment is required, which is a factor that reduces assembly efficiency, and improvements in these are desired.

[Purpose of invention]

This idea was devised in light of the above circumstances, and its purpose is to provide a highly reliable product that can perform heating in a stable electric field, as well as improve durability and ease of assembly. An object of the present invention is to provide a turntable device for a high frequency heating device.

[Summary of the idea]

That is, in this invention, a fan motor system in which a small pulley is provided on the output shaft of the fan motor is configured as a unit, and is attached to the side wall of the heating chamber, and the output shaft passes through the bottom wall of the heating chamber. By providing a gear unit that is locked to the rotating plate and having a large pulley on the input shaft, and connecting the small pulley and large pulley with a belt, the bottom wall of the heating chamber and the rotating plate can be fixed without the need for a reinforcing plate. The aim is to prevent the shaft from being deformed, to make it more compact by making it into a unit, and to accurately determine the distance between belt axes while improving transmission efficiency.

[Example of idea]

This invention will be explained below based on an embodiment shown in the drawings. Figure 7 shows the appearance of a microwave oven as a high-frequency heating device, Figure 8 shows its front cross section, and Figure 9 shows the appearance of a microwave oven as a high-frequency heating device.
The figures also show a side cross section, FIG. 10 a back cross section, and FIG. 11 a plane cross section. In the figures, 1 is the main body. A heating chamber 2 is provided on the left side of the main body 1, and a machine chamber 3 is formed on the right side of the main body 1. Further, a magnetron 4 is provided at the center of the upper stage of the machine room 3. The magnetron 4 is connected to the center of the upper wall of the heating chamber 2 via a waveguide 5, so that microwaves can be oscillated into the heating chamber 2 through the waveguide 5. In addition, in the machine room 3, there is a heat shield plate 6 located at the boundary between the machine room 3 and the heating chamber 2.
is interposed to block heat from the heating chamber 2 side toward the machine room 3. In the figure, 7 is a door that opens and closes the opening of the heating chamber 2, which is pivotally supported on the front side of the main body 1, and 8 is an operation panel provided adjacent to the door 7. On the other hand, reference numeral 9 in the figure is a partition plate installed in the machine room 3 and located downstream of the magnetron 4. This partition plate 9 has a width corresponding to the dimension between the heat shield plate 6 and the main body 1, and has a width corresponding to the dimension between the heat shield plate 6 and the main body 1, and
It is composed of an L-shaped plate having a length corresponding to the height of the machine room 3, and divides the machine room 3 into a front side and a rear side. A bell mouth (orifice for preventing backflow) 10 is provided in the upper part of the partition plate 9 facing the magnetron 4, and
A fan 11 is disposed within this bell mouth 10. Further, a fan motor 12 for driving a fan 11 is attached to the bell mouth 10 of the partition plate 9 via a fan motor mounting plate 13 formed in a U-shape. A small pulley 15 is provided at the rear end of the output shaft 14 passing through the mounting plate 13 of the fan motor 12.
2. The fan motor system 16 is constructed into a compact unit by using the fan motor mounting plate 13 as a unit component. Further, a mounting plate 17 is formed on the fan motor mounting plate 13, and the fan motor system 16 is fixed to the side wall portion of the heating chamber 2 through this mounting plate 17. However, the fan motor system 16 is attached to the side wall of the heating chamber 2. Note that the small pulley 15 is arranged so as to protrude rearward within the main body 1. On the other hand, at the bottom of the rear machine room 3 partitioned by the partition plate 9, there is provided an intake port 18 formed by drilling a large number of small holes, and a high-frequency oscillation circuit is configured on the intake port 18. A high voltage transformer 19 is installed. Further, the bottom of the front machine room 3 partitioned by the partition plate 9 is provided with an exhaust port 20 made of a large number of small holes, and the side of the partition plate 9 facing the machine room 3 is provided with an exhaust port 20 made of a large number of small holes. High voltage capacitor 21 which also constitutes the high frequency oscillation circuit
is provided, and as the fan 11 rotates,
Air is taken in from the intake port 18 and the machine room 3 is transferred to the exhaust port 20.
Electrical components such as the high-voltage transformer 19, magnetron 4, and high-voltage capacitor 21 can be cooled with the outside air blown toward the outside. Further, on the front side of the magnetron 4, an intake duct 22 that guides the cooling air reaching the magnetron 4 into the heating chamber 2 is connected. An exhaust port (not shown) and an exhaust duct 23 that communicates the exhaust port with the outside of the main body 1 are provided in the directional portion, and the inside of the heating chamber 2 can be ventilated with cooling air reaching the magnetron 4. It's becoming like that.

On the other hand, a rotary plate 24 is located in the center of the inner bottom of the heating chamber 2.
is rotatably arranged. Also, this heating chamber 2
As shown in FIG. 12, a gear unit 25 is provided on the back side of the bottom wall of. The external appearance of this gear unit 25 is shown in FIG. 13, and the detailed internal structure is shown in FIG. 14. here,
To explain the structure of the gear unit 25, 26 in the figure is a case (corresponding to the gear unit case). This case 26 is composed of a box-shaped lower mounting plate 27 whose interior is divided into two spaces, and a plate-shaped upper mounting plate 28 that closes the opening of the left side space of this lower mounting plate 27. . In addition, 29 is a fixing flange provided at the open end of the lower mounting plate 27;
0 is a partition wall that partitions the inside of the lower mounting plate 27 and has a fixing flange 31 at its upper end. The space on the left side of the lower mounting plate 27 is used as a gear chamber 36, and a large-diameter spur gear 32 and a small-diameter spur gear 33 are placed in the center of the bottom of the gear chamber 36.
An output shaft 34 is rotatably arranged in an upright manner. Note that 35 is a bearing that thrust-bears the lower end of the output shaft 34. Further, at the bottom of the gear chamber 36, adjacent to the output shaft 34, a small-diameter spur gear 3 that meshes with the spur gear 32 is provided.
7. A worm wheel shaft 39 on which worm wheels 38 are arranged in a superposed manner is rotatably disposed. On the other hand, numeral 40 in the figure is a wormshaft that penetrates the gear chamber 36 and a space adjacent to the gear chamber 36 and constitutes an input shaft that is rotatably installed in a horizontal position. At the end of the wormshaft 40 that projects into the gear chamber 36,
A worm 41 that meshes with the worm wheel 38 is provided, and a reduction gear mechanism 43 that is compact and includes a worm gear mechanism 42 with a large deceleration is configured in the gear chamber 36. Further, a large pulley 44 is provided at the end projecting from the lower mounting plate 27 to the outside. In addition, 45 is the wormshaft 40
46 is a bearing that supports the externally projecting end of the wormshaft 40. On the other hand, on the back side of the upper mounting plate 28,
A bearing portion 47 for bearing the output shaft 34 is provided in the center, and adjacent to the bearing portion 47, a small-diameter spur gear 48 and a cam 49 that mesh with the spur gear 33 of the output shaft 34 are mounted in an overlapping manner. A rotary shaft 50 disposed on the shaft 50 is rotatably protruded. The lower mounting plate 27 is arranged in correspondence with the cam surface of the cam 49.
A micro switch 51 is provided for changing the output of microwave oscillation, and the upper mounting plate 28 can be screwed to the lower mounting plate 27 using mounting holes 52 formed on its periphery. , a state in which a deceleration mechanism 43 including a worm gear mechanism 42 is housed inside the case 26, the tip side of the output shaft 34 projects upward from the bearing part 47, and the large pulley 44 projects from the case 26, that is,
As shown in FIG. 13, the gear unit 25 has a compact structure.

And the gear unit 2 configured in this way
5 is a state in which the upper surface of the case 26 is brought into close contact with the bottom wall of the heating chamber 2, and the tip of the output shaft 34, with the strong rear corner of the heating chamber 2 serving as a fixed part 53, as shown in FIG. The screw 53 is passed through from the center of the bottom of the heating chamber 2 to the inside.
It is fixed using a... With this fixation, the large pulley 44 is arranged to protrude toward the rear, which is the side of the heating chamber 2. Further, a circular recess 5 is formed in the area around the output shaft 34 of the upper mounting plate 28, which is the wall opposite to the bottom wall of the heating chamber 2 of the case 26.
4 is provided, and together with a convex portion 55 formed around the output shaft 34 on the bottom wall of the heating chamber 2, it is possible to prevent microwaves from leaking from inside the heating chamber 2 through the output shaft through hole 56. I'm starting to be able to do it. That is, a sufficient cavity 57 is formed within the recess space. Further, as shown in FIGS. 13 and 14, each mounting hole 52 of the upper mounting plate 28 is provided with a respective fixing flange 29,
15, a gap 58 formed between the contact portion of the upper mounting plate 28 and the lower mounting plate 27 is used as a ventilation hole. The interior of the gear unit 25 and further the lower space between the heating chamber 2 and the main body 1 can be ventilated.

Then, the gear unit 25 installed in this way
The rotary plate 24 is removably locked to the tip of the output shaft 34 of the heating chamber 2, and the large pulley 44 of the gear unit 25 and the small pulley 15 of the fan motor 12 are arranged along the rear surface, which is the outer surface of the heating chamber 2. The turntable device 60 is connected by a single belt 59 arranged in parallel and rotates the rotary plate 24 using the power source of the fan motor 12 used for cooling electrical parts.

However, when cooking food,
Food is placed on the rotating plate 24 and stored in the heating chamber 2,
Thereafter, necessary operations can be performed through the operation panel 8. That is, the magnetron 4 and the fan motor 12 function in accordance with the operation, and the magnetron 4 oscillates microwaves into the heating chamber 2 through the waveguide 5. On the other hand, in the fan motor 12, the fan 11 rotates as the fan motor 12 operates, takes in outside air from the intake port 18, and distributes the air into the machine room 3.
Electrical components such as the high-voltage transformer 19, high-voltage condenser 21, and magnetron 4 are cooled by this air distribution, and the cooling air reaching the front of the machine room 3 is exhausted to the outside of the main body 1 through the exhaust port 20. Further, the cooling air that has cooled the magnetron 4 is introduced into the heating chamber 2 through the intake duct 22, ventilates the inside of the heating chamber 2, and then exhausted to the outside of the main body 1 through the exhaust duct 23. On the other hand, the small pulley 15 is rotating with the operation of the fan motor 12, and is connected to the large pulley 4 of the gear unit 25 through the belt 59.
The driving force is transmitted to 4. Then, in the gear unit 25, the driving force is received by the worm gear mechanism 42 to further decelerate, and the deceleration output is transmitted to the spur gear 37.
The information is transmitted from the large diameter spur gear 32 to the output shaft 34.
The rotary plate 24 is rotated at the final deceleration rotation obtained by. While driving the rotary plate 24, the micro switch 51 turns ON/OFF based on the rotation of the cam 49 to change the output of the magnetron 4, thereby properly heating the food.

Thus, as the turntable device 60,
It is now possible to directly transmit the drive from the fan motor 12 to the rotating plate 24 without applying any biasing force to the output shaft 34, which reduces the output that would otherwise be a factor in disturbing the electric field when the food hits the heating chamber 2. Axis 3
4 and the deformation of the bottom wall of the heating chamber 2, stable heating and cooking can be performed with high transmission efficiency. Moreover, since the gear unit 25 does not have an electric part, it is extremely compact and lightweight.Furthermore, since the gear unit 25 is fixed using the strong corner of the heating chamber 2 as a fixed part, the heating chamber 2 will not be deformed. It is reliable, reliable, and excellent for life's work. Furthermore, since the fan motor system 16 and the gear unit 25 are integrated into one unit, assembly is easy, and since they are both fixed to the heating chamber 2, it is possible to accurately determine the distance between the axes of the belt 59. This eliminates the need for adjustment and assembly, making it possible to improve assembly efficiency.

Furthermore, by providing the recess 54 in the case 26,
Main body 1 from inside heating chamber 2 through around output shaft 34
It is possible to prevent the microwaves from leaking inward with a sufficient chiyork gearing effect, and by forming the gap 58 that serves as a ventilation hole in the case 26, the ventilation inside the main body 1 is improved. It has the advantage of being able to achieve

[Effect of idea]

As explained above, according to this invention, by direct transmission using gears, deformation of the bottom wall of the heating chamber and the shaft that receives the rotary plate can be prevented without the need for a reinforcing plate, and By integrating the fan motor system and gear unit, it is possible to make the product more compact and improve assembly efficiency. Moreover, since the unitized fan motor system and gear unit are fixed to the heating chamber, the distance between the belt axes can be determined accurately, improving transmission efficiency and eliminating adjustment and assembly. As a result, it is possible to provide a turntable device that is highly durable, easy to assemble, and highly reliable, and can be heated in a stable electric field.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view showing a conventional turntable device, Figs. 2 and 3 are a front sectional view and a side sectional view showing different turntable devices, and Fig. 4 is a front sectional view showing a conventional turntable device.
The figure is a perspective view showing the transmission system, FIG. 5 is a partial front sectional view showing the deformation of the heating chamber caused by the belt tension, FIG. 6 is a sectional view showing the shaft area, and FIGS. The figure shows an embodiment of this invention, and FIG. 7 is a perspective view showing a high-frequency heating device.
Fig. 8 is a front sectional view, Fig. 9 is a side sectional view, Fig. 10 is a back sectional view, Fig. 11 is a plan sectional view, Fig. 12 is a sectional view showing the gear unit, and Fig. 13. 14 is an exploded perspective view of the gear unit, and FIG. 15 is a sectional view taken along line X-X in FIG. 14. 2... Heating chamber, 4, 19, 21... Magnetron, high voltage transformer, high voltage capacitor (electrical parts),
11...Fan, 12...Fan motor, 15...
...Small pulley, 16...Fan motor system, 24...
Rotating plate, 25... Gear unit, 26... Case (gear unit case), 34... Output shaft, 40...
...Wormshaft (input shaft), 44...Large pulley, 59...Belt, 60...Turntable device.

Claims (1)

[Claims for Utility Model Registration] (1) A turntable device of a high-frequency heating device in which a small pulley is provided on the output shaft of a fan motor that drives a fan for cooling electrical parts, and a rotating plate in a heating chamber is driven through this small pulley. In this case, the fan motor system is configured as a unit and attached to the side wall of the heating chamber, and below the heating chamber there is a gear unit case fixed to the lower surface of the bottom wall of the heating chamber, and one end of the gear unit case is rotatable. an output shaft supported by the heating chamber and whose other end passes through the bottom wall of the heating chamber and engages with the rotary plate; an input shaft connected to the output shaft via a reduction gear mechanism; and a large pulley provided on the input shaft. 1. A turntable device for a high-frequency heating device, characterized in that a gear unit is provided, and a large pulley of the gear unit and the small pulley are connected by a belt. (2) The gear unit case is characterized in that a concave portion is formed in the peripheral portion of the output shaft of the wall portion opposite to the bottom wall of the heating chamber. Heating device turntable device.