JP2001021146A - Heating and cooking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To employ a DC brush-less motor as a fan motor, enable a thermal influence against the motor to be avoided and make a small-sized hot air generating device. SOLUTION: In a device for heating and cooking cooked item in which hot air generated by a hot air generating device arranged at one side of an oven housing is supplied into the oven housing and the cooked item, a fan motor constituting the hot air generating device 29 is applied as a DC brush-less motor 38 and there is provided a rotating shaft 40 connected to a rotor 41 of the motor in such a way that its rotation can be transmitted. A connecting location 41a in at least the rotating shaft 40 of the rotor 41 of the motor is made of a heat-resistance resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating cooker provided with a hot air generating unit for supplying hot air into an oven for heating and cooking an object to be cooked with hot air.

[0002]

2. Description of the Related Art Conventionally, this type of heating cooker has, as schematically shown in FIG. 5, for example, an oven storage 3 having an open front surface in an outer box 2 of the heating cooker 1, and this oven. An RT motor 4 is provided below the storage 3, and a metal disk-shaped rotary net 5 disposed at a lower portion in the oven storage 3 is rotatably provided by the RT motor 4. And
Inside the oven storage 3, for example, metal-made substantially square-shaped square dishes 6 a, 6 b arranged in upper and lower two stages are detachably provided, and a door for opening and closing a front opening of the oven storage 3 is provided in front of the oven storage 3. 7 are provided.

[0003] A hot air generating unit 8 for supplying hot air to the inside of the oven is provided on one side of the oven cabinet 3, for example, on the back side of the back wall 3a. The hot air generating unit 8 includes an annular heater 9 composed of a sheathed heater and a hot air fan 10 arranged side by side, and a hot air casing 11 surrounding the heater 9 and attached to the back wall 3a, and rotationally driving the hot air fan 10. The hot air casing 11 as a fan motor
And an AC shading motor 12 attached and fixed to the outer surface of the motor, and a cooling fan 14 as a self-cooling fan is mounted on a rotating shaft 13 of the motor 12. still,
The cooling fan 14 is, specifically,
Is disposed in a fan casing 15 attached and fixed to the outer surface of the AC motor. The casing 15 also serves to attach and fix the AC dark motor 12.

Accordingly, in such a hot air generating unit 8, when the AC blackening motor 12 and the heater 9 are energized, the hot air fan 10 rotates and the hot air is generated by the heated heater 9. is there. At the same time, the cooling fan 14 is driven to rotate, and the cooling air blows to cool the AC darkening motor 12 itself. On the other hand, the back wall 3a of the oven storage 3 provided with the hot air generation unit 8 as described above.
The upper and lower outlets 1 each have a plurality of through-holes 16 on the center suction side of the hot air fan 10 and a plurality of through-holes on the discharge side corresponding to the heater 9 on the outer side.
7, 18 are formed respectively.

[0005] A cover member 19 is attached to the rear surface of the outer box 2 so as to cover the rear portion of the hot air generating unit 8 having the above-described configuration. Heating cooker 1 as well as a protective cover
It is configured to also serve as a rear plate of a barrel product, and has a shape protruding rearward at a certain distance, particularly in accordance with the protruding form of the AC dark motor 12. The hot-air casing 11 is composed of two heat-shielding plates 11a and 11b as a heat-shielding measure for the heater 9, and has a structure having a space in the double structure to increase the heat-shielding effect. A part of the heat is dissipated outside the hot-air casing 11 to achieve thermal insulation to the surrounding members, and the heater 9
So that the heating efficiency against hot weathering caused by heat is not reduced.

[0006] In the heating cooker 1 having the above-described configuration, when cooking objects (not shown) stored in the upper and lower square dishes 6a and 6b in the oven storage 3, heating and cooking are performed using AC.
By energizing the shader motor 12 and the heater 9,
The air blown by the hot air fan 10 is heated by the heater 9 to generate hot air. The hot air generated by the hot air generating unit 8 is supplied to the upper and lower outlets 17, 18 on the inner wall 3a.
From the oven storage 3. Of these, the upper outlet 1
The hot air supplied from 7 flows in the upper space above the upper square plate 6a as shown by the solid line arrow A in the figure, reaches the inner surface of the front door 7 and circulates downward, and the upper and lower square plates 6a, 6b and the hot air casing 11
Then, the hot air is again heated to a high temperature by the heater 9 and the so-called hot air circulation is performed. On the other hand, the hot air supplied from the lower outlet 18 to the space below the lower square plate 6b reaches the inner surface of the door 7 as shown by the dashed arrow B and goes upward, and also passes through the central space into the hot air casing 11. Return hot-air circulation is performed, and thus the object to be cooked is subjected to desired heating and cooking in a hot-air atmosphere by the hot-air circulation.

[0007] In addition, this type of bear motor 12, which is a fan motor, has a low driving efficiency and generates heat due to its own heat loss. During the heating cooking, the cooling fan 14 is also driven to rotate. As a result, the AC darkening motor 12 itself is cooled to prevent a rise in temperature.

[0008]

According to the above configuration, the hot-air generating unit 8 has the hot-air casing 11 in the axial dimension from the heater 9 and the hot-air fan 10 to the AC shading motor 12 located rearward in the axial direction. It is unavoidable that the motor becomes relatively large due to the presence of the cooling fan 14 and the like. In particular, in the case of the AC shading motor 12, there is a limit to a thin configuration including the coil 12a and the bearing bracket 12b of the rotor. Thus, the motor 12 is configured to protrude greatly rearward.

Moreover, the internal temperature of the hot-air casing 11 becomes a high temperature of about 400 to 500 ° C. due to the heat generated by the heater 9, but part of the heat is directly transmitted through the rotating shaft 13 to which the hot-air fan 10 is connected. The heat is directly conducted to the AC shading motor 12, and in addition to the heat generated by the motor 12 itself, the temperature is further increased to deteriorate the driving efficiency, or the lubricating property is impaired due to seizure of the bearing bracket 12 b and the like, so that the fan motor as a fan motor can be used. Reliability decreases. For that purpose, it is necessary to increase the blowing capacity of the cooling fan 14 to increase the size.

Accordingly, the cover member 19 surrounding the hot air generating unit 8 with a predetermined distance therebetween has a shape protruding rearward as shown in the figure, and has a protruding dimension up to the cover member 19 behind the oven storage 3. Increase S0,
As a result, the depth dimension W0 of the product as the heating cooker 1 is increased, so that the installation area is increased and the volume ratio in the oven occupied by the oven storage 3 is deteriorated. The shape protruding rearward of the member 19 not only has a poor external appearance even though it is the rear surface of the product, but also has a problem that the material cost increases as the external dimensions in the front-rear direction of the product increase.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and therefore has as its object to adopt a DC brushless motor as a fan motor and to suppress heat conduction to the motor.
An object of the present invention is to provide a heating cooker in which a highly reliable hot air generation unit is reduced in size.

[0012]

In order to achieve the above object, a heating cooker according to the present invention supplies hot air generated by a hot air generating unit provided on one side of an oven storage into an oven storage. In the apparatus for cooking an object to be cooked, the hot-air generating unit includes a hot-air casing attached to a side wall of an oven storage and having a heater and a hot-air fan inside, and the hot-air fan provided outside the casing at one end. A fan motor having a connected rotating shaft, wherein the fan motor is a DC brushless motor, and at least a portion of the rotor of the motor that connects and supports the rotating shaft is made of a heat-resistant resin. (Invention of claim 1).

[0013] According to such a configuration, the connecting portion is made of a heat-resistant resin with respect to heat conduction from the rotating shaft to the rotor, so that the rotor is not thermally affected by thermal deformation or the like. When employing a DC brushless motor as a fan motor, this is one of the factors for ensuring the life or reliability of this type of DC brushless motor 38.
It is effective for maintaining the straightness of the rotating shaft with respect to the rotor for a long period of time, and it can make full use of the features of the original DC brushless motor, such as thinning, low heat loss, and good driving efficiency. Since the axial dimension can be reduced, the depth dimension of the heating cooker as a product can be reduced and the product can be installed efficiently, and at the same time, the appearance of the rear portion of the product can be improved.

According to the first aspect of the present invention, there is further provided a metal cooling fan attached to and fixed to the rotating shaft and disposed between the DC brushless motor and the hot air casing. Invention).

According to this configuration, the provision of the cooling fan allows the DC brushless motor to be blown and cooled by the generation of cooling air accompanying the rotation thereof, as well as to cool the periphery of the hot-air casing on the heat generation source side. Since the metal cooling fan has good thermal conductivity, it absorbs and radiates the heat transmitted through the rotating shaft, which is more effective in avoiding thermal influence on the motor side.

[0016] Further, in the second aspect, the DC
The brushless motor includes a chassis formed of a spoke integrally formed with the stator side and extending in a direction perpendicular to the axis, and a cylindrical portion extending in the axial direction from an extended end of the spoke. A cooling fan is disposed at the end (the invention of claim 3).

According to such a configuration, the chassis is connected to the DC
Not only for mounting the brushless motor, but also by integrally providing the cylindrical portion containing the cooling fan, it can function effectively as a fan casing of the cooling fan and improve the air blowing efficiency of the cooling fan, and therefore the number of parts The expected cooling effect can be expected with a simple configuration that suppresses the increase in the temperature.

According to a second or third aspect of the present invention, the cooling fan is a centrifugal fan (the invention of the fourth aspect).

According to this configuration, since the cooling fan is a centrifugal fan, the fan has excellent ventilation performance in the radial direction. Therefore, even when the rotating shaft is not directly located in the cooling air blowing direction, the cooling fan is in contact with the cooling air. Are prosperous and are cooled effectively.

Further, in any one of the second to fourth aspects, the cooling fan is formed of an aluminum alloy or an aluminum-coated steel sheet (the invention of the fifth aspect).

According to this structure, since the aluminum-based material has a particularly high thermal conductivity, the heat-dissipating action is large accordingly. Therefore, the heat-dissipating action from the cooling fan is further enhanced because the cooling fan itself receives the cooling action. Most of the heat that has been promoted and transmitted from the hot air casing to the rotating shaft is released from the cooling fan, and as a result, the thermal effect on the DC brushless motor due to heat conduction through the rotating shaft can be effectively avoided.

Further, in any one of the second to fifth aspects, the connecting portion between the cooling fan and the rotating shaft has a surface extending over a side surface of the cooling fan facing the hot air casing and a surface of the rotating shaft. 7. A heat conductive conductor made of metal that is in contact with the device is attached.

According to such a configuration, much of the heat transmitted to the rotating shaft is efficiently transmitted to the good heat conductor that is in wide surface contact, and thereafter is efficiently taken into the cooling fan and is so-called heat absorbed. Accordingly, the cooling fan itself is cooled by the rotation of the cooling fan, so that the heat radiation action is promoted, and thus the thermal effect on the DC brushless motor side due to the heat conduction of the rotating shaft can be effectively avoided. This is advantageous in that the durability of a bearing mechanism that supports a rotating shaft built in the motor is increased, and that the life and reliability of the motor are extended.

[0024] In the first aspect, the DC
The rotary shaft of the brushless motor is formed of a heat insulating ceramic (the invention of claim 7).

According to this configuration, since the rotating shaft is formed of ceramic having a low thermal conductivity, the thermal effect due to heat conduction to the bearing mechanism of the rotating shaft incorporated in the DC brushless motor can be avoided more reliably. Therefore, there is an advantage that other heat-resistant structures can be simplified accordingly.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Hereinafter, a first embodiment of a heating cooker according to the present invention will be described with reference to FIGS. First, FIG.
FIG. 1 shows a schematic vertical sectional side view of a metal oven cabinet 23 having a front opening inside an outer box 22 and a plurality of upper and lower metal oven cabinets 23 arranged in the oven cabinet 23, for example. Square plates 24 and 25 are detachably accommodated through a front opening, and a metal disk-shaped rotating net 26 is provided below the lower square plate 25 in the lower portion of the outer box 22. R
It is provided so as to be rotatable by a T motor 27. A door 28 is provided at the front opening of the oven storage 23 so as to be openable and closable, and a hot air generation unit 29 to be described later is provided at a rear side on one side of the oven storage 23.
Is attached to the rear portion of the outer box 22.

FIG. 1 is an enlarged longitudinal sectional view showing a rear portion of the cooking device 21 having the hot air generating unit 29 shown in FIG. 2, and the hot air generating unit 29 shown in FIG.
The back wall 23a, which is one of the side walls forming the oven chamber 23, has a metal hot air casing 31 attached to the back side thereof by screws or the like. In order to enhance the heat shielding effect so that the heat of a heater 34 to be described later is not radiated to the outside, for example, the two heat shielding plates 31a and 31b form a double structure having a space and the outer heat shielding plate 31a. A heat insulator 32 made of glass wool is adhered to the outer surface of the glass to further enhance the heat shielding effect.

In such a hot air casing 31, a centrifugal hot air fan 33 rotatably arranged and an annular heater 34 composed of a season heater arranged on the discharge side of the outer periphery of the hot air fan 33 are provided. In addition to the hot air fan 3
In the back wall 23a corresponding to the suction side of No. 3, a suction port 35 composed of a plurality of through-hole groups is formed, and a plurality of through-hole groups is formed near the heater 34 on the discharge side with the suction port 35 interposed therebetween. An upper outlet 36 and a lower outlet 37 are respectively formed.

A DC brushless motor 38 as a fan motor is provided outside the hot air casing 31. The motor 38 has a magnet 39 on its inner peripheral side.
And a resin outer rotor 41 connected and supported by a metal rotary shaft 40, a coil 42 disposed inside the rotor 41, and an oil-impregnated bearing 43 rotatably supporting the rotary shaft 40. And a stator 45 having a resin housing 44 provided therein. One end of the rotating shaft 40 penetrates through the hot air casing 31 and the heat insulator 32 to connect the hot air fan 33 to a tip end thereof. .

In such a configuration, at least the connecting portion 41a of the rotor 41 with the rotating shaft 40 is
It is made of a resin material that is rigid, has low thermal conductivity, and has high heat resistance, such as polybutylene terephthalate, and is particularly tough because of its excellent long-term heat resistance and flame retardancy. In order to connect the rotor 41 having such a configuration to the rotating shaft 40, the fitting position of the rotating shaft 40 is subjected to, for example, knurling, and the connecting portion 41a is press-fitted to the processed portion. Thus, the rotating shaft 40 is connected to and supported by the rotor 41 so that rotation can be transmitted. However, the connecting portion 41a of the rotor 41 is integrated by molding or welding when the rotor 41 is manufactured.

Further, in the DC brushless motor 38 of the present embodiment, a self-cooling cooling fan 46 composed of a propeller fan protruding radially from the outer peripheral side of the rotor 41 is integrally formed. From the stator 45 side, a plurality of, for example, three spokes 47 extend in a direction perpendicular to the axis (radial direction) from the housing 44, and extend in the axial direction from the extending end to enclose the rotor 41 and the cooling fan 46. A chassis 49 having a skeleton structure including the shape portions 48 is integrally formed. The cylindrical portion 48 has a substantially double cylindrical structure as shown in FIG.
Is a cooling fan 46 which is cylindrical and is disposed inside thereof.
And has a function as a fan casing.
8b is formed in the shape of a substantially square square tube inscribed in the inner tube 48a, and this double tube structure makes the chassis 49 a rigid structure.

The DC brushless motor 38 configured as described above is mounted and fixed to the outer surface side of the hot air casing 31 via the chassis 49. That is, the chassis 49
At the four corners of the outer tube 48b of the cylindrical portion 48
A columnar fixing member 50 made of, for example, a ceramic material having a high heat resistance and a low thermal conductivity is joined by an adhesive or the like,
The fixing member 50 is connected and fixed by screwing in a state where the fixing member 50 penetrates the heat insulator 32 and abuts on the hot air casing 31.

Therefore, the configuration of the hot air generating unit 29 provided on the rear side, which is one side of the oven storage 23, consists of the hot air fan 33 and the heater 3 provided in the hot air casing 31.
4 and a DC brushless motor 38 for driving the hot air fan 33 to rotate.
Is fixed to the hot-air casing 31 via a chassis 49 and a fixing member 50, and a cooling fan 46 for self-cooling integrally formed with the rotor 41 has a cylindrical portion 48 functioning as a fan casing when it rotates. Inner cylinder 48
A generates cooling air in the axial flow direction, and cools the periphery thereof together with the DC brushless motor 38 itself.

On the other hand, as shown in FIG. 1, a cover member 30 provided at the rear portion of the outer box 22 has a large number of transparent members on a rear surface area opposed to the DC brushless motor 38 for sucking outside air for cooling. An intake port 30a composed of a group of holes is provided, and an exhaust port 30b for exhaust is provided in an outer peripheral side surface area.
An air passage is formed through the cooling fan 46 interposed between the suction and exhaust ports 30a and 30b inside the cylindrical portion 48, so that a so-called cooling air passage is formed.

The operation of the heating cooker 21 of the present embodiment constructed as described above will be described. For example, in the case of so-called oven cooking for cooking a cookie, a roll pan or the like, two square plates 24 and 25 are provided. An object to be cooked (dough) is stored and placed, and is stored in the oven storage 23 and is set up and down in two stages. After the door 28 is closed, a setting operation such as menu selection is performed by an operation control unit (not shown) and a start operation is performed.

Thus, the heater 34 of the hot air generating unit 29 is energized to generate heat, and the DC brushless motor 38 is energized to drive the hot air fan 33.
The air blown by the rotation of is heated to be hot-airized, and the hot air is
The air is supplied from the upper and lower outlets 36 and 37 into the oven chamber 23 and flows in the directions of arrows A and B shown in FIG. That is, first, the air in the oven chamber 23 is taken into the hot air casing 31 from the suction port 35 of the rear wall 23a with the rotation of the hot air fan 33, and is heated by the heater 34 in the casing 31 to become hot air. The gas is discharged from the upper and lower outlets 36 and 37 into the oven chamber 23. And these upper and lower outlets 36, 37
The hot air flows from the inside of the compartment partitioned by the square plates 24 and 25 arranged in two stages, reaches the inner surface of the front door 28, passes through the central space, and returns to the suction port 35 of the back wall 23 a again.
The hot air is further sucked into the hot air casing 31, heated by the heater 34, and hot-airized, and the hot air circulation is performed by this repetition, so that the hot air is evenly distributed throughout the inside of the refrigerator. Then, the hot air supplied into the oven storage 23 as described above keeps the inside of the storage at a high temperature, and the objects stored in the square dishes 24 and 25 are evenly heated and cooked.

During the heating and cooking, the temperature around the hot air generating unit 29 is inevitably increased due to the heat generated by the heater 34. Therefore, in the present embodiment, the hot air casing 31 has a double structure including the heat shielding plates 31a and 31b having a space in order to increase the heat shielding effect on the heater 34,
Further, in order to reduce heat dissipation from the outer surface of the hot air casing 31, the heat insulating material 3 made of glass wool is used.
2 is affixed. Thus, heat dissipation from the heater 34 is prevented as much as possible, and a decrease in heating efficiency during heating cooking is suppressed. However, it is still unavoidable that a part of the heat is radiated to the surroundings through the hot air casing 31, and heat conduction is performed through the metal rotating shaft 40 which extends into the high temperature hot air casing 31 and connects the hot air fan 33. As a result, part of the heat is directly extracted to the outside. Also,
Heat conduction from the high-temperature hot-air casing 31 is also conceivable to the cylindrical portion 48 of the chassis 49 through the fixing member 50 connected and fixed to the hot-air casing 31.

However, the cooling fan 46 integral with the rotor 41 of the DC brushless motor 38 is simultaneously driven to rotate, and the cylindrical inner tube 48a of the cylindrical portion 48 containing the cooling fan 46 effectively functions as a fan casing. hand,
Cooling air in the direction of arrow C shown in FIG. 1 is generated by efficiently taking in outside air. That is, the intake port 30 at the rear of the cover member 30
The outside air introduced from a and passing through the chassis 49 of the skeleton structure and therefore between the spokes 47 is used as cooling air,
In addition to the cooling of the DC brushless motor 38 in the cooling air passage, the chassis 49, which is concerned about the heat conduction,
Cools the peripheral members such as the heat insulating body 32 on the outer surface of the hot air casing 31 including the periphery of the fixing member 50 between the connecting portions of the hot air casing 31 and the cooling air. After cooling, the air is discharged from the exhaust port 30b on the side of the cover member 30.

Therefore, by the rotational drive of the cooling fan 46 as described above, the cooling air is effectively blown to the connecting portion to the chassis 49 and the rotating shaft 40 where heat conduction is directly concerned from the high-temperature hot-air casing 31 side. The fixing member 50 made of a heat-resistant material having a low heat conductivity and having a low heat conductivity is particularly employed in the connection portion with the chassis 49 because the heat is easily concentrated, so that further heat insulation can be expected. On the other hand, the DC brushless motor 38 which may be heated by the heat radiation action from the hot air casing 31 or the oven chamber 23 side.
In addition, the resin chassis 49 which is easily deformed by heat is effectively blown and cooled, so that any thermal influence of heat conduction or heat radiation can be avoided.

In addition, the above-described chassis 49 of this configuration is constructed by the DC brushless motor 38 by the outer cylinder 48b of the cylindrical portion 48.
Of the cooling fan 46,
Such as a fan casing.
It can be provided with a simple configuration while suppressing an increase in the number of parts, and since the cylindrical portion 48 has a substantially double cylindrical structure, the chassis 49 made of resin can have a rigid structure as a whole.
This is particularly advantageous when mechanical strength is required. However, the outer cylinder 48b of the cylindrical portion 48 is not necessarily limited to a rectangular cylindrical shape, and may have a configuration in which mounting legs having an arbitrary shape are protruded for mounting on the hot air casing 31 side. good.

As described above, the rotating shaft 40 receiving heat conduction is blown and cooled by the cooling fan 46 to suppress the temperature rise. However, the heat is further increased at the connecting portion between the rotating shaft 40 and the DC brushless motor 38. In order to achieve security,
At least the rotating shaft 40 of the outer rotor 41
Is formed of a resin material having a low thermal conductivity, particularly a heat resistant resin, so that even if the rotor 41 receives heat conduction from the rotating shaft 40, it can sufficiently resist heat deformation and the like. Can be prevented. This is especially true for this type of DC.
One of the factors for ensuring the life or reliability of the brushless motor 38 is to maintain the straightness of the rotating shaft 40. Therefore, in this configuration, the straightness between the rotor 41 and the rotating shaft 40 is thermally controlled. It is extremely effective because it can be maintained for a long time without being affected.

Thus, according to the present embodiment, it is possible to avoid any thermal effects of heat conduction or heat radiation from the oven storage 23 on the heat generation source side and particularly from the hot air casing 31 side during oven cooking. As a result, the reliability of the DC brushless motor 38 as a fan motor is increased, and stable and fixed mounting for a long time can be maintained.

The DC adopted as the fan motor
The brushless motor 38 is a conventional AC dark motor 1
As compared with 2, the driving efficiency is better, the heat loss of the motor itself is small, the power consumption can be reduced and the noise can be reduced, and the thickness can be greatly reduced, and the axial dimension including the motor 38 can be minimized. Accordingly, the entire hot air generating unit 29 can be reduced in size by thinning, and the cover member 30 does not need to be configured to protrude greatly rearward, and the rearward protrusion dimension S1 can be effectively reduced. Therefore, not only the appearance is good, but also the depth dimension W1 in the front-rear direction of the heating cooker 21, which is a product, can be reduced, so that the installation conditions can be eased accordingly, and the oven storage 23 occupies the entire product. It is possible to provide the heating cooker 21 suitable for actual use, which is expected to improve the volume ratio in the refrigerator.

FIG. 4 shows a second embodiment of the present invention, in which the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Only mentioned.

(Second Embodiment) FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment of the present invention. The structure and mounting structure of the cooling fan 51 are different from those of the first embodiment. The cooling fan 51 is attached and fixed to the rotating shaft 52 between the DC brushless motor 38 and the hot air casing 31. Specifically, the cooling fan 51 is made of a metal having a large heat conductivity, for example, an aluminum alloy or The centrifugal fan is made of aluminum coated (plated) steel plate.

The rotating shaft 52 of the cooling fan 51
The mounting structure of the rotary shaft 52 is provided with a screw groove 52a.
Are formed, and the retaining ring 5
After fitting the cooling fan 51 and then fitting the cooling fan 51, a female screw portion is provided inside, and a heat-resistant conductor 54 made of a metal having a nut function, for example, made of stainless steel is screwed and fixed. In particular, the heat good conductor 54 is provided at least in the hot air casing 31 of the cooling fan 51 in the mounting state.
It has a shape that makes wide surface contact over the side surface of the side and the surface of the rotating shaft 52, and a nut-shaped head is formed at the outer end so that the screwing operation can be easily performed. I have to.

The operation of the second embodiment having the above-described structure will be described.
Just like the embodiment, the hot air generated by the hot air generation unit 29 is circulated and supplied into the oven cabinet 23, so that the objects to be cooked stored in the square plates 24 and 25 (see FIG. 2) are simultaneously heated and cooked. During the cooking, cooling air is generated by the rotation of the cooling fan 51 attached to the rotating shaft 52, and FIG.
The DC brushless motor 38 in the cooling air passage as in the first embodiment by the cooling air in the direction indicated by the arrow D therein,
The connecting portion between the chassis 49 and the hot air casing 31 and its peripheral members are cooled.

On the other hand, part of the heat in the hot air casing 31 is taken out through the metal rotary shaft 52 and reaches the mounting base of the cooling fan 51 by heat conduction, first of all, comes into wide surface contact with the surface of the rotary shaft 52. A large amount of heat is taken in by conducting heat to the good heat conductor 54, and the heat is conducted to the cooling fan 51 through a portion in wide surface contact with the side surface of the other cooling fan 51, so-called heat is absorbed and the temperature tends to increase. . However, since the cooling fan 51 of this configuration is made of a metal having a high thermal conductivity such as an aluminum alloy, the cooling fan 51 has a large heat radiating action. The operation is further enhanced, and much of the heat transmitted to the rotating shaft 52 is released from the cooling fan 51. In addition, the above-mentioned heat conductor 54 in the present configuration also serves to attach and fix the cooling fan 51 at the same time as the attachment of itself to the rotating shaft 52, thereby suppressing an increase in the number of parts and the number of assembling steps.

In addition, in this configuration, since the cooling fan 51 is a centrifugal fan, the cooling fan 51 is excellent in the blowing performance in the radial direction. Therefore, the cooling fan 51 is not directly located in the blowing direction of the cooling wind. The contact becomes active and is cooled effectively. Thus, heat conduction to the DC brushless motor 38 side after the cooling fan 51 via the rotating shaft 52 is suppressed, that is, transmission of high-temperature heat to the rotor 41 can be prevented. Therefore, thermal influence on the rotor 41 side can be reliably avoided, and there is no possibility that a thermal deformation of the resin-made rotor 41 itself or a demagnetization effect due to an increase in temperature of the magnet 39 will occur. One of the factors for obtaining the life and reliability of the motor 38 is the rotation shaft 5 described above.
In addition to the straightness of 2, the performance of the bearing mechanism of the rotating shaft 52 depends on the performance, but the oil-impregnated bearing 43 in the housing 44, which is a bearing mechanism for rotatably supporting the rotating shaft 52, has a sufficient rotating shaft 52. The oil-impregnated bearing 43 is less likely to cause an early running out of oil, a seizure phenomenon, or the like, and has excellent durability.

Therefore, when the DC brushless motor 38 is adopted as the fan motor, it can be mounted and fixed stably without any problem, and the height dimension (axial dimension) of the hot air generating unit 29 having such a configuration is kept small. In addition to the thinning of the DC brushless motor 38 and the downsizing of the hot air generating unit 29 as in the first embodiment, the rearward projection S1 can be reduced, and the The cooking device 21 having a reduced depth dimension (corresponding to W1 in FIG. 1) can be provided. In this embodiment,
The heat good conductor 54 is provided with a female thread portion and has a nut function, and is directly screwed and fixed. However, the present invention is not limited to this. For example, the heat good conductor 54 may be configured to simply fit on the rotating shaft 52. The mounting means may be variously modified, for example, a configuration may be adopted in which a separately prepared original nut is screwed in to pinch and fix the thermal good conductor 54.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings. For example, in each of the above embodiments, the rotating shaft 40 or 52 is made of metal. If it is formed of a material having a low conductivity, for example, a heat insulating ceramic, the thermal effect due to heat conduction to the DC brushless motor 38 can be more reliably avoided, and other heat-resistant structures can be omitted or simplified as necessary. Yes,
Further, the hot air casing 31 is divided into two heat shield plates 31a, 31.
b, and further, a heat insulating body 32 is provided on the outer surface of the casing 31 to disclose a hot air generating unit 29 having a higher heat shielding effect and a higher heating efficiency. The hot air generating unit 29 may be provided on the rear wall 23a at the rear side, which is one side of the oven chamber 23, but may be provided on any one of the peripheral side walls. For example, the present invention can be appropriately modified and implemented without departing from the gist of the present invention.

[0052]

As described above, according to the present invention, a hot air generating unit is provided on one side of an oven chamber, and the hot air generated from the hot air generating unit is circulated in the oven to heat and cook. A DC brushless motor is adopted as a fan motor to be configured, and at least a portion of the motor for connecting and supporting the rotating shaft of the rotor is made of a heat-resistant resin, so that one end of the rotating shaft connected to a hot-air fan in a hot-air casing. And the thermal effect on the rotor due to the heat conduction through the DC motor can be avoided, so that the characteristics of the original DC brushless motor can be effectively used, and the hot air generation unit can be made thinner and smaller. Thus, a cooking device suitable for practical use can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a main part showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing the overall schematic configuration.

FIG. 3 is a rear view of the hot air generation unit.

FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 5 is a diagram corresponding to FIG. 2 showing a conventional example.

[Explanation of symbols]

21 is a cooking device, 22 is an outer box, 23 is an oven, 2
3a is a back wall (side wall), 29 is a hot air generation unit, 30 is a cover member, 31 is a hot air casing, 33 is a hot air fan, 34 is a heater, 35 is a suction port, 36 is an upper outlet,
37 is a lower outlet, 38 is a DC brushless motor, 4
Reference numerals 0 and 52 indicate a rotating shaft, 41 indicates a rotor, 41a indicates a connecting portion,
45 is a stator, 46 and 51 are cooling fans, 47 is a spoke, 48 is a cylindrical portion, 49 is a chassis, and 54 is a heat conductor.

Claims (7)

[Claims] 1. An apparatus for supplying hot air generated by a hot air generation unit provided on one side of an oven storage to an oven storage to heat and cook an object to be cooked, wherein the hot air generation unit includes a side wall of the oven storage. A hot-air casing having a heater and a hot-air fan attached to the inside thereof, and a fan motor having a rotating shaft provided outside the casing and having one end connected to the hot-air fan, wherein the fan motor is a DC brushless motor. A heating cooker characterized in that at least a part of the rotor of the motor for connecting and supporting the rotating shaft is made of a heat-resistant resin. 2. The cooking device according to claim 1, further comprising a metal cooling fan fixed to the rotating shaft and disposed between the DC brushless motor and the hot air casing. 3. A DC brushless motor includes a chassis formed of a spoke integrally formed with a stator side thereof and extending in a direction perpendicular to an axis, and a cylindrical portion extending in an axial direction from an extended end of the spoke. The heating cooker according to claim 2, wherein a cooling fan is disposed inside the cylindrical portion of the chassis. 4. The cooking device according to claim 2, wherein the cooling fan is a centrifugal fan. 5. The heating cooker according to claim 2, wherein the cooling fan is formed of an aluminum alloy or an aluminum-coated steel plate. 6. The connecting portion between the cooling fan and the rotating shaft,
The heating cooker according to any one of claims 2 to 5, further comprising a metal heat conductor that is in surface contact with the cooling fan side surface facing the hot air casing side and the rotating shaft surface. 7. The DC brushless motor according to claim 1, wherein the rotating shaft is formed of a heat insulating ceramic.
The heating cooker as described.