JP2003130357A - Cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a quick cooker that can prevent generation of noise, reduction in blast volume and rotational failure of a fan and realizes a reduced manufacturing cost. SOLUTION: An inner circumference of a scroll portion 531 of a fan casing 53 is defined by a partial arc concentric with an outer circumference of a centrifugal fan 51, and the centrifugal fan 51 used is mounted with three blades. The design of the scroll portion 531 of the fan casing 53 dispenses with complex computation, and the number of parts of the centrifugal fan 51 is small to reduce manufacturing cost. The inner circumference of the scroll portion 531 of the fan casing 53 and the outer circumference of the centrifugal fan 51 are protected against having a partly extremely small clearance to prevent foreign matter from causing a clog under dust, oil and the like and prevent the centrifugal fan 51 from being in contact with the inner circumference of the scroll portion 531 of the fan casing 53 due to an error in the dimensions and mounting position of the centrifugal fan.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating cooker, such as a convection oven or a hot air impact type oven, which heats and cooks an object to be cooked.

[0002]

2. Description of the Related Art Generally, a heating cooker 1 for heating an object to be cooked, such as a convection oven or a hot air impact type oven, has a box body 2 which is heat-insulated by heat insulating means as shown in FIG. The box 2 is provided with a heating chamber 3 for storing the food to be cooked therein, a heating unit 4 for heating the food to be cooked in the heating chamber 3, and a blowing unit 5.
The blower means 5 includes a centrifugal fan 51 and a centrifugal fan 51.
Drive motor 52 for driving the suction port 6 and the air outlet 7
In the heating chamber 3 and a fan casing 53 axially supporting the centrifugal fan 51, and the hot air heated by the heating means 4 is heated by the blowing means 5 in the heating chamber 3. Introduce to cook food to be cooked.

As a conventional technique of this type of cooking device 1, for example, as disclosed in Japanese Utility Model Publication No. 6-23841, a blower 54 consisting of a so-called sirocco fan 51a is provided on the right side of the heating chamber 3. At the same time, the heater 41 is arranged as the heating means 4 on the suction port 6 side of the blower 54. Then, the blower 54 blows the high-temperature air heated by the heater 41 from the right side to the left side of the heating chamber 3, and a large number of food items such as bread are arranged on the shelf 31 of the heating chamber 3 for cooking. To be done.

In this conventional cooking device 1, as shown in FIG. 16, the fan casing 53a has a rectangular shape, and the centrifugal fan 51 is a multi-blade centrifugal fan 51a such as a so-called sirocco fan. Was used.

Further, as another conventional technique in the above-described heating cooker 1, as described in, for example, Japanese Unexamined Patent Publication No. 2000-329351, the blower 54 is rotated forward and backward at predetermined intervals. By sending uniform hot air into the heating chamber 3, the food to be cooked is suitably cooked.

In this other conventional heating cooker 1, FIG.
As shown in FIG. 7, the fan casing 53a has a rectangular shape, and the centrifugal fan 51 is adapted to be capable of forward rotation and reverse rotation (directions A and B in FIG. 17). A so-called radial fan 51b having a linear blade extending outward from the center has been used.

As another conventional technique, as described in, for example, Japanese Patent Publication No. 9-503334, a high temperature air heated by a heater 41 is blown by a blower 54.
Since the cooking is performed by the hot air impact method of colliding with the cooking object at high speed, the cooking object is heated and cooked in a short time.

In this hot-air shock type oven which is still another conventional heating cooker 1, as shown in FIG. 18, the inner shape of the fan casing 53b, that is, the so-called scroll portion 531 is the outer peripheral surface of the centrifugal fan 51. And a tongue portion 5 near the side end of the air outlet 7 in the air flow path.
32 were formed. As the centrifugal fan 51, a sirocco fan 51a, a radial fan 51b, and a turbo fan 51c have been used.

[0009]

However, the conventional heating cooker and other conventional heating cookers have a problem that the cooking time is long. In order to shorten the cooking time, the rotation speed of the centrifugal fan 51 may be set high, that is, the air volume may be increased and the heat amount of the heater 41 may be increased. However, this increases power consumption significantly. Not
There was a fatal problem that the noise increased significantly.

In still another conventional heating cooker,
The problem of long cooking time commonly found in the above conventional heating cookers and other conventional heating cookers is solved by performing cooking by the hot air shock method. In this method, the heater 41 is used. Although the cooking time can be greatly shortened while suppressing the increase in the power consumption of the device, there is a problem that the noise is extremely large and the convenience of the user is greatly impaired. Furthermore, since the scroll portion 531 of the fan casing 53 has a spiral internal shape, complicated calculation using an exponential function is required in designing, which causes a problem of increased manufacturing cost. Further, in the portion where the tongue portion 532 is formed, the distance between the outer peripheral surface of the fan and the inner peripheral surface of the scroll portion 531 of the fan casing 53 becomes extremely narrow, so that the air is introduced from the suction port into the scroll portion 531 of the fan casing 53. Foreign matter such as dust or oil that has flowed in is apt to be clogged in this portion, causing the rotating fan to come into contact with the foreign matter to generate noise, air to flow backward (8 in FIG. 18), and the problem that the fan cannot rotate. This is also caused by the fact that the outer peripheral surface of the fan comes into direct contact with the tongue portion 532 due to an error in the shape or mounting position of the fan. Further, in this case, there is a problem that the desired performance cannot be exhibited even if the fan is driven in reverse.

Further, in these conventional heating cookers,
Since it uses a multi-blade centrifugal fan, it not only causes an increase in manufacturing cost, but also because the gap between the blades is narrow, foreign matter such as dust and oil easily accumulates, which causes noise and reduces the amount of air blown. There was a problem, and there was a problem that frequent maintenance was required.

An object of the present invention is to reduce the manufacturing cost of the scroll portion of the fan casing and the fan, and to cause foreign matter such as dust to be clogged in the air passage and the fan in the fan scroll casing. It is an object of the present invention to provide a heating cooker capable of preventing generation of noise, reduction of air flow, and fan rotation failure.

[0013]

The cooking device according to the present invention comprises:
The following configuration is provided as a means for solving the above problems.

1) A box, a heating chamber provided in the box for accommodating an object to be cooked, a heating means for heating an object to be cooked in the heating chamber, and the hot air of the heating means for heating. And a blower that is introduced into the chamber, and the blower communicates with the centrifugal fan and the heating chamber at the inlet and the outlet,
Consisting of a fan casing supporting the centrifugal fan,
The internal shape of the scroll portion of the fan casing is characterized by being formed by an arc centered on the rotation axis of the centrifugal fan.

In this structure, the internal shape of the scroll portion of the fan casing through which the air in the heating chamber passes from the suction port toward the outlet port by the rotation of the centrifugal fan is
It is formed concentrically with the outer circumference of the centrifugal fan. Therefore, the interval between the inner peripheral surface of the scroll portion of the fan casing and the outer peripheral surface of the centrifugal fan becomes substantially uniform over the entire circumference,
Since the gap does not become extremely narrow partially, foreign matter such as dust and oil does not become clogged, and even if there is an error in the fan shape or mounting position, the outer peripheral surface of the fan is The convenience of not contacting the inner peripheral surface of the scroll part and causing noise or fan rotation failure due to these, and the hot air impact method of blowing high-speed hot air to the object to be cooked Both of the conveniences of shortening the cooking time can be realized at the same time by performing the cooking method. Further, even when the fan is rotated in the reverse direction as needed, a desired air volume can be sufficiently ensured. Further, there is no need for complicated calculation in designing the internal shape of the scroll portion of the fan casing.

2) The inner diameter D of the scroll portion of the fan casing is characterized by satisfying the relationship of 0.6≤d1 / D≤0.9, where d1 is the outer diameter of the centrifugal fan.

In this structure, the inner diameter D of the scroll portion of the fan casing for securing the air volume required for heating and cooking is calculated by an extremely simple algebraic calculation based on the outer diameter d1 of the centrifugal fan. Therefore, the internal shape of the scroll portion of the fan casing having a predetermined air volume can be designed very easily.

3) The inner diameter D of the scroll portion of the fan casing is characterized by satisfying the relationship of 0.75≤d1 / D≤0.85, where d1 is the outer diameter of the centrifugal fan.

In this structure, the inner diameter D of the scroll portion of the fan casing for making the air flow rate, the air blowing efficiency and the noise amount more appropriate is calculated by an extremely simple algebraic calculation based on the outer diameter d1 of the centrifugal fan. . Therefore, the internal shape of the scroll portion of the fan casing, which has a more appropriate air flow rate, blowing efficiency, and noise level, can be designed very easily. That is, it is possible to easily realize a low-noise, high-efficiency hot-air shock heating cooker.

The suction port is a circular hole having a constant inner diameter in the air passage direction.

In this structure, the inner diameter of the suction port is made constant in the air passage direction. Therefore, it is not necessary to form a special shape such as a throttle in the suction port, and the manufacturing cost of the fan casing can be reduced.

5) The inner diameter d2 of the suction port is characterized by satisfying the relationship of 0.3≤d2 / D≤0.8, where D is the inner diameter of the scroll portion of the fan casing.

In this structure, the inner diameter d2 of the suction port for allowing a large amount of air in the heating chamber to flow into the scroll portion of the fan casing from the suction port is extremely simple based on the inner diameter D of the scroll portion of the fan casing. It is calculated by calculation. Therefore, the shape of the scroll portion of the fan casing having an air volume sufficient for hot air shock type cooking can be designed very easily.

6) The inner diameter d2 of the suction port is characterized by satisfying the relationship of 0.4≤d2 / D≤0.6, where D is the inner diameter of the scroll portion of the fan casing.

In this configuration, the inner diameter d2 of the suction port for making the air flow rate, the air blowing efficiency, and the noise amount more appropriate is calculated by an extremely simple algebraic calculation based on the inner diameter D of the scroll portion of the fan casing. Therefore, the shape of the scroll portion of the fan casing having a more appropriate air flow rate, air blowing efficiency, and noise level can be designed very easily.

7) The suction port is composed of a plurality of holes.

In this structure, the suction port is formed of a plurality of punch-shaped or slit-shaped holes having appropriate sizes. Therefore, the user's hand and the food to be cooked do not enter the blower through the suction port, and the safety is improved.

8) The total area A of the suction port formed by the plurality of holes is D which is the inner diameter of the scroll portion of the fan casing.
As

[0029]

[Table 3]

It is characterized by satisfying the relationship of

In this structure, the total area A of the suction port for allowing a large amount of air in the heating chamber to flow into the scroll portion of the fan casing from the suction port is extremely simple based on the inner diameter D of the scroll portion of the fan casing. It is calculated by algebraic calculation. Therefore, the shape of the scroll portion of the fan casing having an air volume sufficient for hot air shock type cooking can be designed very easily.

9) The total area A of the suction port formed by the plurality of holes is the inner diameter D of the scroll portion of the fan casing.
As

[0033]

[Table 4]

It is characterized by satisfying the relationship of

In this structure, the total area A of the suction port for making the air volume, the air blowing efficiency and the noise volume more appropriate is calculated by an extremely simple algebraic calculation based on the inner diameter D of the scroll portion of the fan casing. . Therefore, the shape of the scroll portion of the fan casing having a more appropriate air flow rate, air blowing efficiency, and noise level can be designed very easily.

10) The centrifugal fan is characterized in that the number of blades is Z, the chord length is C, and the outer diameter is d1, and the relationship of CZ / d1≤5 is satisfied.

In this configuration, the blade number Z of the centrifugal fan is calculated by a very simple algebraic calculation based on the ratio of the product of the chord length C and the blade number Z to the outer diameter d1 of the centrifugal fan. Therefore, the centrifugal fan for ensuring a sufficient air volume in the hot air shock type cooking is extremely easily designed.

11) The centrifugal fan has two blades.

In this structure, a centrifugal fan having two blades is used. Therefore, compared to the case of using a multi-blade centrifugal fan, the cost of parts is reduced and the distance between the blades is maximized, so that the centrifugal fan may be clogged with foreign matter such as dust or oil. In addition, no loud noise is generated and the air volume does not decrease.

12) The centrifugal fan is characterized by being formed by a single plate-shaped member.

In this structure, the two blades are formed by a single plate-shaped body. Therefore, a centrifugal fan that does not generate a large amount of noise or reduce the air volume is extremely easily manufactured.

13) The centrifugal fan has three blades.

In this structure, a centrifugal fan having three blades is used. Therefore, compared to the case where a multi-blade centrifugal fan is used, the cost of parts is reduced and the distance between the blades is increased, so that foreign matter such as dust or oil may be clogged in the centrifugal fan. In addition, no loud noise is generated and the air volume does not decrease.

14) In the centrifugal fan, the angle θ formed by the straight line connecting the center of rotation and the inner end of the blade and the straight line connecting the inner end and the outer end of the blade is negative in the case of the forward blade and in the case of the backward blade. The case is positive, and the range is set to −40 ° ≦ θ ≦ 90 °.

In this specification, the forward blade means a blade whose inner end is located rearward of the outer end in the rotation direction of the centrifugal fan, and the rearward blade means that the inner end of the blade is the rotation of the centrifugal fan. A wing located forward of the outer edge in the direction.

In this structure, the blade angle of the centrifugal fan is set within a predetermined range. Therefore, the optimum shape of the centrifugal fan is selected according to the air volume required for the hot air shock type cooking and the rotation speed of the centrifugal fan.

15) In the centrifugal fan, an angle θ formed by a straight line connecting the center of rotation and the inner end of the blade and a straight line connecting the inner end and the outer end of the blade is set to be positive in the case of the rearward-directed blade and is 3
It is characterized in that it is set in the range of 0 ° ≦ θ ≦ 60 °.

In this structure, the blade angle of the centrifugal fan is set to a state in which the air flow rate, the blowing efficiency and the noise amount are made more appropriate. Therefore, in the hot air shock type cooking, a centrifugal fan having a more appropriate air flow rate, ventilation efficiency and noise level can be easily designed.

16) In the centrifugal fan, an angle θ formed by a straight line connecting the center of rotation and the inner end of the blade and a straight line connecting the inner end and the outer end of the blade is set to be positive in the case of the rearward-directed blade.
It is characterized by being set to 0 °.

In this structure, the blade angle of the centrifugal fan is set to a state that optimizes the air flow rate, the blowing efficiency and the noise level. Therefore, in the hot air shock type cooking, the centrifugal fan having the optimum air flow rate, blowing efficiency and noise level can be easily designed.

17) The centrifugal fan has a flat blade shape.

In this structure, a centrifugal fan having flat blades is used. Therefore, a centrifugal fan suitable for hot air shock type cooking is very easily designed and manufactured.

[0053]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side sectional view showing the configuration of a hot air shock heating cooker 1a according to the first embodiment of the present invention, and FIG. 2 is a hot air shock heating cooking according to the present embodiment. It is sectional drawing of the air blower 54 used for the container 1a. The hot-air shock heating cooker 1a of the present embodiment includes a box body 2 that is heat-insulated by a heat insulating means, a heat-insulating door 21 that opens and closes a front opening of the box body, and the box body 2. Is provided,
A heating chamber 3 for accommodating an object to be cooked, a shelf 31 for placing the object to be cooked, a heating means 4 for heating the object to be cooked placed on the shelf 31, and a blowing means 5. Consists of
Further, the blower unit 5 communicates with the centrifugal fan 51, a drive motor 52 that drives the centrifugal fan 51, the suction chamber 6 and the air outlet 7 to the heating chamber 3, and pivotally supports the centrifugal fan 51. The air blower 54 is composed of a fan casing 53 having a scroll portion 531 and the hot air heated by the heater 41 installed as the heating means 4 is introduced into the heating chamber 3 by the air blowing means 5. Cook the food. The shelf 31 may be replaced by a plate-shaped pan, and the heating means 4
As a substitute for the heater 41, a microwave heating device may be used.

As shown in FIG. 2, the fan casing 53
The inner peripheral surface of the scroll portion 531 is formed of a 3/4 arc concentric with the outer peripheral portion of the centrifugal fan 51. The suction port 6 is not given a complicated shape such as a so-called bell mouth, and the inner diameter of the suction port 6 is constant in the vertical direction, which is the ventilation direction. The inner diameter d2 of the suction port 6 is sized to satisfy the relationship of d2 / D = 0.5 with respect to the inner diameter D of the scroll portion 531 of the fan casing 53. Further, the outer diameter d1 of the centrifugal fan 51 is sized to satisfy the relationship of d1 / D = 0.8 with respect to the inner diameter D of the scroll portion 531 of the fan casing 53.

With this structure, inside the scroll portion 531 of the fan casing 53, the centrifugal fan 51 rotates in a state where an appropriate interval is formed over the entire circumference between the centrifugal fan 51 and the inner peripheral surface of the scroll portion 531 of the fan casing 53. In a part of the scroll portion 531 of the fan casing 53, the scroll portion 53 of the fan casing 53
The distance between the inner peripheral surface of 1 and the outer peripheral surface of the centrifugal fan 51 does not become narrow, and foreign matter such as dust and oil that has flowed in from the suction port 6 does not partly become clogged, and high speed is achieved from the air outlet 7 The hot air can be blown into the heating chamber 3, and the centrifugal fan 51 does not come into contact with a part of the inner peripheral surface of the scroll portion 531 of the fan casing 53 due to an error in the size or the mounting position of the centrifugal fan 51, and the centrifugal fan 51 sends the hot air. It is possible to prevent the reduction of the air flow, the generation of excessive noise, and the stoppage of the rotation of the centrifugal fan 51.

Further, since dust, oil and the like are less likely to stay in the scroll portion 531 of the fan casing 53, it is possible to reduce the frequency of maintenance of the blower 54 of the hot air shock heating cooker 1a.

Further, a partial backflow which is generated by the rotation of a general centrifugal fan is not generated, a sufficient air volume can be secured, and a large noise is not generated. Further, it is not necessary to provide the suction port 6 of the fan casing 53 with a complicated shape such as a so-called bell mouth and the scroll portion 531 of the fan casing 53.
Since it is not necessary to use an exponential function in designing, the manufacturing cost can be reduced.

The centrifugal fan 51 has a fan casing 53.
Rotates in the direction of arrow A in the scroll portion 531 of
Three flat blades 511 are attached at equal intervals (120 °) in the rotation plane. The blade 511 includes a straight line connecting the rotating shaft 512 of the centrifugal fan 51 and an inner end portion (front side edge in the rotation direction) of the blade 511, an outer end portion (rear side edge in the rotation direction) and an inner end portion of the blade 511. It is attached to the centrifugal fan 51 such that the angle θ formed by the straight line connecting the lines is 40 °. The chord length C of the blades 511 is set to a length that satisfies the relationship of CZ / d1 = 1.2 with respect to the number of blades Z in the centrifugal fan 51 and the outer diameter d1 of the centrifugal fan 51. Further, the height of the blades 511 of the centrifugal fan 51 is set to the maximum size within a range that does not hinder the rotation of the centrifugal fan 51 in the scroll portion 531 of the fan casing 53.

As described above, since the centrifugal fan 51 is provided with a small number of flat blades 511, the blade 511 can be easily designed and the number of parts of the centrifugal fan 51 can be reduced. The manufacturing cost can be further reduced. In addition, the distance between the blades 511 can be increased, foreign matter such as dust and oil does not clog the blades 511, and the amount of air blown does not decrease or the frequency of maintenance does not increase.

FIG. 3 shows the PQ characteristics, the efficiency and the specific noise value of the centrifugal fan 51 of the hot air shock heating cooker 1a according to the above-mentioned embodiment at the same power consumption (constant of 10 W), as well as other conventional cooking methods. So-called sirocco fan 51a used in the conventional hot air shock type cooking device which is the cooking device 1.
It is a figure which shows the result of having compared with. As shown in the figure,
Centrifugal fan 51 of the hot-air shock heating cooker 1a
Is equal to or higher than the so-called sirocco fan 51a used in the conventional hot-air shock heating cooker in all of the performance, efficiency and specific noise value.

FIG. 4 shows measurement of PQ characteristics, efficiency and specific noise value at the same power consumption (constant 10 W) when the outer diameter of the centrifugal fan in the hot air shock heating cooker 1a according to the above embodiment is changed. It is a figure which shows a part of result. Based on this result, the outer diameter d of the centrifugal fan 51 that is compatible with the inner diameter D of the scroll portion 531 of the fan casing 53 of the centrifugal fan 51 of the hot-air shock heating cooker 1a.
A range of 1 was determined. From various experimental results including results not shown, the outer diameter d1 of the centrifugal fan 51 used in the hot air shock heating cooker 1a is 0.6 ≦ d1 / D with respect to the inner diameter D of the scroll portion 531 of the fan casing 53. Reasonable performance could be secured in the range of ≤ 0.9. Particularly, in the range of 0.75 ≦ d1 / D ≦ 0.85, the optimum air volume, efficiency and specific noise value could be obtained.

FIG. 5 shows the PQ characteristics, the efficiency and the specific noise value at the same power consumption (constant 10 W) when the inner diameter of the suction port 6 in the hot air shock type cooking device 1a according to the above embodiment is changed. It is a figure which shows a part of result. Based on this result, the range of the inner diameter d2 of the suction port 6 that matches the inner diameter D of the scroll portion 531 of the fan casing 53 in the hot-air shock heating cooker 1a was determined. From various experimental results including results not shown, the inner diameter d2 of the suction port 6 in the hot-air shock heating cooker 1a is 0.3 ≦ d2 / D ≦ 0 with respect to the inner diameter D of the scroll portion 531 of the fan casing 53. A reasonable performance could be secured in the range of 0.8. Particularly, in the range of 0.4 ≦ d2 / D ≦ 0.6, the optimum air volume, efficiency and specific noise value could be obtained.

6 and 7 show the blades 5 of the centrifugal fan 51 of the hot-air shock heating cooker 1a according to the above embodiment.
At the same power consumption when the mounting angle of 11 is changed (10
It is a figure which shows the result of having measured PQ characteristic of W constant), efficiency, and a specific noise value. Based on this result, the range of the attachment angle θ of the blade 511 that fits the hot-air shock heating cooker 1a was determined. From the experimental results shown in the figure, it was possible to secure a proper performance in the range of −40 ° ≦ θ ≦ 90 ° for the mounting angle θ of the blade 511 in the hot-air shock heating cooker 1a. Particularly, in the range of -30 ° ≤ θ ≤ 60 °, the optimum air volume, efficiency and specific noise value can be obtained, and the maximum result was obtained at θ = 40 °.

In the results shown in FIGS. 6 and 7, the blade 51
The mounting angle θ of 1 has a positive value when the inner end of the blade 511 is located in front of the outer end in the rotation direction of the centrifugal fan 51 (in the case of a rearward-facing blade), and the inner end of the blade 511 is the centrifugal fan 51. A negative value is set when the position is located rearward of the outer end with respect to the rotation direction (in the case of the forward wing).

Based on the above experimental results, the centrifugal fan 5
By setting the outer diameter d1 of 1, the inner diameter d2 of the suction port 6 and the mounting angle θ of the blade 511 to be optimum values, simplification of the structure and reduction of manufacturing cost due to reduction of the number of parts can be achieved, while air volume and efficiency can be reduced. Heat cooker with excellent noise and noise 1
a can be obtained.

The blade 511 can have any shape other than a flat plate as long as the cost does not increase significantly. Further, although the blades 511 are not necessarily attached to the centrifugal fan 51 at equal intervals, if they are attached at unequal intervals, it is necessary to make the weight balance uniform in order to prevent uneven rotation of the centrifugal fan 51.

Further, the blades 51 attached to the centrifugal fan 51
The number Z of 1 can be increased or decreased based on CZ / d1 ≦ 5. Especially, in the range of 1.0 ≦ CZ / d1 ≦ 1.5, the manufacturing cost is low and the centrifugal fan is excellent in blowing performance. 51 can be obtained.

A mixed flow fan or a mixed flow fan may be used instead of the centrifugal fan 51. As shown in FIG.
The disk 513 of the centrifugal fan 51 may support the vertical middle portion of the blade 511. In this case, compared to the configuration shown in FIG.
A structure for strengthening the strength of the fixed portion with 11 is required.

In addition, a shape such as a so-called bell mouth can be added to the suction port 6 provided that the manufacturing cost does not increase significantly.

FIG. 9 is a side sectional view showing the structure of the hot air shock type cooking device 1b according to the second embodiment of the present invention. The hot-air shock heating cooker 1b according to this embodiment
Differs from the hot-air shock heating cooker 1a according to the first embodiment shown in FIG. 1 in that the suction port 6 is configured by a plurality of slits 61 instead of a single circular hole. There is. The total area A of the suction port 6 is the fan casing 53.
For the inner diameter D of the scroll portion 531 of

[0071]

[Table 5]

The size satisfies the relationship of Further, as is clear from the cross-sectional view of the blower 54 shown in FIG. 10, the number of blades 511 attached to the centrifugal fan 51 is two. In other respects, the hot-air shock heating cooker 1b is common to the hot-air shock heating cooker 1a, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

The PQ characteristics, the efficiency and the specific noise value at the same power consumption (constant 10 W) when the total area of the slit 61 of the suction port 6 in the hot air shock type cooking device 1b according to the above embodiment is changed are shown. Based on the measurement result (not shown) similar to 5, the range of the total area A of the slit 61 of the suction port 6 that matches the inner diameter D of the scroll portion 531 of the fan casing 53 in the hot air impact type cooking device 1b is determined. I asked. From various experimental results, the total area A of the suction port 6 in the hot-air shock heating cooker 1a is compared with the inner diameter D of the scroll portion 531 of the fan casing 53.

[0074]

[Table 6]

It was possible to secure an appropriate performance in the range of.
In particular,

[0076]

[Table 7]

It was possible to obtain the optimum air flow rate, efficiency and specific noise value in the range of.

According to the hot-air shock heating cooker 1b of the second embodiment shown in FIGS. 9 and 10, in addition to the effect of the hot-air shock heating cooker 1a of the first embodiment, suction There is no need for the user's hands or food to be cooked into the blower 54 through the mouth 6, and the effect of increasing the safety of the hot-air shock heating cooker 1b can be obtained. Also, the work of attaching the wing 511 to the disk 513 is reduced,
The manufacturing cost of the centrifugal fan 51 is further reduced.

Note that the two blades 511 attached to the centrifugal fan 51 can also be constituted by a single flat plate as shown in FIGS. 11 and 12, and in particular, as shown in FIG. By using the flat plate as it is, the manufacturing cost of the centrifugal fan 51 can be further reduced.

FIG. 13 is a side sectional view showing the structure of a hot air shock heating cooker 1c according to the third embodiment of the present invention, and FIG. 14 is a front sectional view showing the structure of the hot air shock heating cooker 1c. Is. Compared with the hot-air shock heating cooker 1a according to the first embodiment shown in FIG. 1, the hot-air shock heating cooker 1c according to this embodiment has a plurality of suction ports 6 instead of a single circular hole. The blade 511 of the centrifugal fan 51 is set to θ = 10 ° Z = 10 CZ / d1 = 1.5, and the space 514 inside the inner periphery of the blade 511 of the centrifugal fan 51 is formed. Large, centrifugal fan 51 and suction port 6
Between the plurality of punch holes 62, that is, the space 514
A honeycomb-shaped deodorizing material 9 is provided. Also, FIG.
As is clear from the cross-sectional view of the blower 54 shown in FIG. 5, the inner peripheral surface of the scroll portion 531 of the fan casing 53 is constituted by two quarter arcs that are concentric with the outer peripheral portion of the centrifugal fan 51. The air delivered by rotating in the direction of arrow A is branched in the fan casing 53 in the directions of arrows C and D shown in FIGS. 14 and 15, and the air delivered in the direction of C is directed to the upper surface of the heating chamber 3. The air blown out in the D direction from the provided upper surface outlet 71 is provided from the side surface outlet 72 provided on the side surface of the heating chamber 3,
Each of them is configured to be ejected into the heating chamber 3. In other respects, the hot-air shock heating cooker 1c is common to the hot-air shock heating cooker 1a, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

With this configuration, according to the hot-air shock heating cooker 1c according to the third embodiment, in addition to the effect obtained by the hot-air shock heating cooker 1a according to the first embodiment, the suction port 6 is provided. Therefore, the effect that the safety of the hot-air shock heating cooker 1c is increased without the user's hands or the food to be cooked entering the blower 54. Further, since the deodorizing material 9 is provided in the space 514 between the centrifugal fan 51 and the suction port 6, it is possible to efficiently deodorize smoke and odor generated when the food to be cooked is cooked in the heating chamber 3. The effect that can be obtained is obtained. Furthermore, since the hot air sent from the blower 54 can be branched into two directions of the upper surface and the side surface, and the hot air can be jetted from the upper surface outlet 71 and the side surface outlet 72 of the heating chamber 3, respectively, the food to be cooked can be more The effect that it can be cooked uniformly is obtained. In addition,
The rotation of the centrifugal fan can be normal rotation or reverse rotation (see Fig. 1).
5 arrow A direction, B direction).

[0082]

According to the present invention, the following effects can be obtained.

1) The internal shape of the scroll portion of the fan casing, through which the air in the heating chamber passes from the suction port toward the outlet port due to the rotation of the centrifugal fan, is formed concentrically with the outer periphery of the centrifugal fan. The inner peripheral surface of the scroll part and the outer peripheral surface of the centrifugal fan can be made substantially uniform over the entire circumference, and the interval between the inner peripheral surface of the scroll part of the fan casing and the outer peripheral surface of the centrifugal fan is partially It does not become extremely narrow, and it is possible to prevent foreign matter such as dust and oil from becoming clogged, and even if there is an error in the shape or mounting position of the fan, the outer peripheral surface of the fan will be the scroll part of the fan casing. It is possible to prevent contact with the inner peripheral surface of the fan, and to prevent noise and rotation failure of the fan due to these. Further, by performing the hot air impact type cooking method in which high-speed hot air is sprayed on the object to be cooked, both convenience of shortening the cooking time can be realized at the same time.
Further, even when the fan is rotated in the reverse direction as needed, a desired air volume can be sufficiently ensured. Further, the design of the internal shape of the scroll portion of the fan casing does not require complicated calculation, and the manufacturing cost can be reduced.

2) The inner diameter D of the scroll portion of the fan casing for securing the air volume required for heating and cooking is calculated by an extremely simple algebraic calculation based on the outer diameter d1 of the centrifugal fan to obtain a predetermined air volume. The internal shape of the scroll portion of the fan casing can be designed very easily, and the manufacturing cost of the low-noise, high-efficiency hot air shock type cooking device can be reduced.

3) Inner diameter D of the scroll portion of the fan casing for making the air flow rate, air flow efficiency and noise level more appropriate
Is calculated by an extremely simple algebraic calculation based on the outer diameter d1 of the centrifugal fan, the inner shape of the scroll portion of the fan casing, which has a more appropriate air volume, blowing efficiency, and noise amount, can be designed very easily. The manufacturing cost of the low-noise, high-efficiency hot-air shock heating cooker can be further reduced.

4) By making the inner diameter of the suction port constant in the air passage direction, it is not necessary to form a special shape such as a throttle on the suction port, and the manufacturing cost of the fan casing can be further reduced.

5) The inner diameter d2 of the suction port for inflowing a large amount of air from the heating chamber into the scroll portion of the fan casing is calculated by an extremely simple algebraic calculation based on the inner diameter D of the scroll portion of the fan casing. By doing so, it is possible to design the shape of the scroll portion of the fan casing with a sufficient air volume for hot air shock type cooking, and it is possible to reduce the manufacturing cost.

6) By calculating the inner diameter d2 of the suction port for making the air volume, the ventilation efficiency and the noise volume more appropriate on the basis of the inner diameter D of the scroll portion of the fan casing by an extremely simple algebraic calculation, The shape of the scroll portion of the fan casing, which has a more appropriate ventilation efficiency and noise amount, can be designed very easily, and the manufacturing cost can be further reduced.

7) By forming the suction port with a plurality of holes having a punch shape or slit shape of an appropriate size, it is possible to prevent the user's hand, food, etc. from entering the blower through the suction port. It is possible to realize a highly safe hot air shock type cooking device.

8) The total area A of the suction port for allowing a large amount of air in the heating chamber to flow from the suction port into the scroll portion of the fan casing is calculated by an extremely simple algebraic calculation based on the inner diameter D of the scroll portion of the fan casing. By the calculation, the shape of the scroll portion of the fan casing having a sufficient air volume for hot air shock type cooking can be designed very easily, and the manufacturing cost can be reduced.

9) By calculating the total area A of the suction port for making the air volume, the air blowing efficiency and the noise volume more appropriate by an extremely simple algebraic calculation based on the inner diameter D of the scroll portion of the fan casing, In addition, the shape of the scroll portion of the fan casing, which has a more appropriate ventilation efficiency and noise amount, can be designed very easily, and the manufacturing cost can be further reduced.

10) The number of blades Z of the centrifugal fan is calculated by a very simple algebraic calculation based on the ratio of the product of the chord length C and the number of blades Z to the outer diameter d1 of the centrifugal fan, and thus the hot air shock method is used. The centrifugal fan for ensuring a sufficient air volume in the above cooking can be designed very easily, and the manufacturing cost can be further reduced.

11) By using a centrifugal fan having two blades, the cost of parts can be reduced and the distance between the blades can be maximized as compared with the case of using a multi-blade centrifugal fan. Therefore, foreign matter such as dust and oil is not clogged in the centrifugal fan, and it is possible to prevent generation of large noise and reduction of air volume.

12) By forming the two blades by a single plate-like member, it is possible to extremely easily manufacture a centrifugal fan that does not generate a large amount of noise or reduce the air volume, and the manufacturing cost is reduced. It can be cheaper.

13) By using a centrifugal fan having three blades, the cost of parts can be reduced as compared with the case of using a multi-blade centrifugal fan, and the distance between the blades can be increased to centrifuge. It is possible to prevent clogging of foreign matters such as dust and oil in the fan, and it is possible to prevent generation of large noise and reduction of the air volume.

14) By selecting the angle of the blade of the centrifugal fan within a predetermined range, the optimum shape of the centrifugal fan is selected according to the air volume required for hot air shock cooking and the rotation speed of the centrifugal fan. You can

15) By setting the blade angle of the centrifugal fan to a state in which the air volume, the air blowing efficiency and the noise amount are more appropriate, the air volume, the air blowing efficiency and the noise amount are more appropriate in the hot air shock type cooking. Centrifugal fan can be designed easily.

16) By setting the blade angle of the centrifugal fan to a state in which the air volume, the air blowing efficiency and the noise amount are optimized, the centrifugal fan having the optimal air volume, air blowing efficiency and noise amount in the hot air shock type cooking is provided. Can be designed more easily.

17) By using a centrifugal fan equipped with flat blades, a centrifugal fan suitable for hot air shock type cooking can be designed and manufactured very easily, and the manufacturing cost can be further reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a configuration of a hot-air shock type heating cooker according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a blower in a hot-air shock heating cooker.

3A and 3B are a PQ characteristic, a noise value comparison diagram, and a fan efficiency comparison diagram between the same hot-air shock heating cooker and a conventional hot-air shock heating cooker.

FIGS. 4A and 4B are a PQ characteristic, a noise value comparison diagram, and a fan efficiency comparison diagram when the outer diameter of the centrifugal fan in the hot-air shock heating cooker is changed.

[Fig. 5] (A) and (B) are PQ characteristics when the inner diameter of the suction port in the same hot air shock heating cooker is changed,
It is a noise level comparison diagram and a fan efficiency comparison diagram.

6 (a) and 6 (b) are PQ characteristics when the mounting angle of the blades in the hot-air shock heating cooker is changed,
It is a noise level comparison diagram and a fan efficiency comparison diagram.

FIG. 7 is a diagram showing measurement results of blower performance, efficiency, and noise value when the mounting angle of the blades in the hot air shock heating cooker is changed.

FIG. 8 is a diagram illustrating another configuration of the centrifugal fan in the hot-air shock heating cooker.

FIG. 9 is a side sectional view showing a configuration of a hot-air shock heating cooker according to a second embodiment of the present invention.

FIG. 10 is a cross-sectional view of a blower in the hot air shock heating cooker.

FIG. 11 is a view showing a configuration of a centrifugal fan in the hot air shock type heating cooker.

FIG. 12 is a diagram showing another configuration of the centrifugal fan in the hot air shock type heating cooker.

FIG. 13 is a side sectional view showing a configuration of a hot air impact type heating cooker according to a third embodiment of the present invention.

FIG. 14 is a front cross-sectional view showing the configuration of the same hot-air shock heating cooker.

FIG. 15 is a cross-sectional view of a blower in the hot air shock heating cooker.

FIG. 16 is a cross-sectional view of a blower in a conventional heating cooker.

FIG. 17 is a sectional view of a blower in another conventional heating cooker.

FIG. 18 is a side sectional view showing the configuration of still another conventional hot air shock heating cooker.

FIG. 19 is a cross-sectional view of a blower in the hot air shock type cooking device.

[Explanation of symbols]

1 cooker 2 boxes 21 insulated door 3 heating chambers 31 shelves 4 heating means 41 heater 5 Blower means 51 Centrifugal fan 51a Sirocco fan 51b radial fan 51c turbo fan 511 wings 512 rotation axis 513 disc 52 Drive motor 53 fan casing 53a Rectangular fan casing 53b spiral fan casing 531 Scroll section 532 tongue 54 blower 6 Suction port 61 slits 62 punch holes 7 outlet 71 Upper surface outlet 72 Side outlet 8 reflux 9 Deodorant

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F04D 29/44 F04D 29/44 U X 29/58 29/58 L 29/66 29/66 MN F term (Reference) 3H033 AA02 AA13 BB02 BB06 BB20 CC01 CC03 DD03 DD06 DD27 3H034 AA02 AA13 BB02 BB06 BB20 CC03 DD08 DD25 EE02 EE06 EE08 3H035 CC01 CC02 CC06 DD04 DD05

Claims (17)

[Claims] 1. A box, a heating chamber provided in the box for accommodating an object to be cooked, a heating means for heating the object to be cooked in the heating chamber, and hot air of the heating means for heating. And a blower that is introduced into the chamber, wherein the blower is a centrifugal fan,
The fan casing is connected to the heating chamber at the suction port and the air outlet and axially supports the centrifugal fan, and the internal shape of the scroll portion of the fan casing is an arc centered on the rotation axis of the centrifugal fan. A cooker characterized by being 2. The inner diameter D of the scroll portion of the fan casing satisfies the relationship of 0.6 ≦ d1 / D ≦ 0.9, where d1 is the outer diameter of the centrifugal fan. Cooking device. 3. The inner diameter D of the scroll portion of the fan casing satisfies the relationship of 0.75 ≦ d1 / D ≦ 0.85, where d1 is the outer diameter of the centrifugal fan. Cooking device. 4. The heating cooker according to claim 1, wherein the suction port is a circular hole having a constant inner diameter in the air passage direction. 5. The inner diameter d2 of the suction port satisfies the relationship of 0.3 ≦ d2 / D ≦ 0.8, where D is the inner diameter of the scroll portion of the fan casing. Heating cooker. 6. The inner diameter d2 of the suction port satisfies the relationship of 0.4 ≦ d2 / D ≦ 0.6, where D is the inner diameter of the scroll portion of the fan casing. Heating cooker. 7. The cooking device according to claim 1, wherein the suction port is composed of a plurality of holes. 8. The total area A of the suction port formed by the plurality of holes is represented by the following formula, where D is the inner diameter of the scroll portion of the fan casing: The heating cooker according to claim 7, which satisfies the relationship. 9. The total area A of the suction port formed of the plurality of holes is represented by the following table, where D is the inner diameter of the scroll portion of the fan casing. The heating cooker according to claim 8, which satisfies the relationship. 10. The centrifugal fan satisfies the relationship of CZ / d1 ≦ 5, where Z is the number of blades, C is the chord length, and d1 is the outer diameter. The cooker described. 11. The cooking device according to claim 10, wherein the centrifugal fan has two blades. 12. The heating cooker according to claim 11, wherein the centrifugal fan is formed of one plate-shaped body. 13. The cooking device according to claim 10, wherein the centrifugal fan has three blades. 14. The centrifugal fan has an angle θ formed by a straight line connecting a center of rotation and an inner end of a blade and a straight line connecting an inner end and an outer end of the blade, with a forward blade having a negative angle and a backward blade having an angle θ. The heating cooker according to any one of claims 1 to 14, wherein the case is positive and the range is set to -40 ° ≤ θ ≤ 90 °. 15. The centrifugal fan has an angle θ formed by a straight line connecting a center of rotation and an inner end of a blade and a straight line connecting an inner end and an outer end of the blade, with a positive angle in the case of a rearward-directed blade, 30 °. 15. The heating cooker according to claim 14, wherein the range is ≦ θ ≦ 60 °. 16. The centrifugal fan has an angle θ formed by a straight line connecting a center of rotation and an inner end of a blade and a straight line connecting an inner end and an outer end of the blade, with a positive value in the case of a rearward-directed blade, 40.
The heating cooker according to claim 15, wherein the heating cooker is set to °. 17. The cooking device according to claim 1, wherein the centrifugal fan has a flat blade shape.