JP2011007080A - Centrifugal fan and heating cooker using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal fan which realizes reduction in cost and performance variation, compactification and enhancement of strength and reliability.SOLUTION: The fan includes a resin made blade portion 82 formed by integrally molding a plurality of blades 83 radially arranged and annular connection part 84 for connecting the blades 83, and a metal disc 81 covering one face in an axial direction of the blade portion 82. The disc 81 is provided with a plurality of engaging holes 81b thereon. Engaging claws 83a inserted into the engaging holes 81b in a radial width narrower than the engaging holes 81b and engaged therewith, are projected to one ends in the axial directions of the blades 82.

Description

  The present invention relates to a centrifugal fan in which a plurality of blades are arranged radially on a disk. The present invention also relates to a cooking device using a centrifugal fan.

  A conventional centrifugal fan has a plurality of blades standing radially on a disc, and sucks in an axial direction from the opposite side of the disc and guides the gas radially outward by a centrifugal force to be exhausted. This centrifugal fan is formed of a resin in which a disc and a blade are integrally formed. A centrifugal fan in which a metal disk and blades are integrated by caulking or the like is also known.

  Patent Documents 1 and 2 disclose a mixed flow fan in which a plurality of resin blades are integrated by a metal holding member. In this mixed flow fan, a metal spider (arm portion) is integrated with a resin blade by insert molding. Spiders are radially welded to a metal ring member. Thereby, a blade | wing can be formed in a complicated shape and the intensity | strength of a fan can be improved with a metal ring-shaped member and a spider.

Japanese Patent Application Laid-Open No. 2002-195190 (page 3 to page 6, FIG. 2) Japanese Patent Laid-Open No. 2002-242886 (pages 4-10, FIG. 2)

  A centrifugal fan in which the above-described disk and blade are integrally formed of resin can reduce the cost. However, in order to ensure the strength of the disk that collides with the gas flowing in the axial direction, there has been a problem that the thickness of the disk becomes large and the centrifugal fan becomes large. Moreover, when the disc and the blade are formed of metal, it is difficult to form a blade having a complicated shape. In addition, since a work for attaching a plurality of blades to the disk is required, there is a problem that the cost is increased and the variation in performance is increased depending on the assembly accuracy.

  Also, as in Patent Documents 1 and 2, it is possible to attach each blade made of resin to a metal disk. However, as in the above case, the number of assembling steps increases, and the variation in performance due to the assembling accuracy increases. In addition, in a high temperature environment such as a heating cooker, the metal part and the resin part may be detached due to a difference in thermal expansion due to a temperature change, and there is a problem that the reliability of the centrifugal fan is lowered.

  An object of the present invention is to provide a centrifugal fan that is low in cost, has little performance variation, is small in size, and has high strength and reliability, and a cooking device using the centrifugal fan.

  In order to achieve the above object, a centrifugal fan according to the present invention includes a resin blade portion integrally formed with a plurality of radially arranged blades and an annular connecting portion for connecting the blades, and an axial direction of the blade portion. A disk made of metal that covers one surface, and has a plurality of engagement holes on the disk, and is inserted into and engaged with the engagement holes with a width smaller in the radial direction than the engagement holes. An engaging claw is provided at one end of the blade in the axial direction.

  According to this configuration, the end surface opposite to the intake side of the resin blade portion in which a plurality of blades are integrated by the annular connecting portion is covered with the metal disk. The disk is provided with an engagement hole, and the blade is provided with an engagement claw that is inserted through the engagement hole and engaged therewith. The engaging claw has a radial width smaller than that of the engaging hole, and has a radial play and is inserted into the engaging hole. When the temperature of the centrifugal fan rises, the difference in thermal expansion between the blade part and the disk is absorbed by the play between the engagement hole and the engagement claw.

  According to the present invention, in the centrifugal fan configured as described above, the engagement hole and the engagement claw are provided on the outer peripheral side and the inner peripheral side of the blade portion, and the radial width of the engagement hole on the outer peripheral side is set to the inner side. It is characterized by being larger than the circumferential side.

  According to the present invention, in the centrifugal fan configured as described above, the centrifugal fan includes a turbo fan in which the blades are arranged rearward with respect to the rotation direction.

  Moreover, the heating cooker of this invention connects the centrifugal fan of said each structure, the heating chamber which accommodates a foodstuff, the suction inlet and outlet which open to the said heating chamber, and the said inlet and said outlet. And a circulation duct in which the centrifugal fan is arranged, and a heater provided in the circulation duct, and the centrifugal fan takes in the circulation duct from the suction port by the centrifugal fan and heats it by the heater. The cooking device which blows out from a blower outlet WHEREIN: The suction side of the said centrifugal fan is arrange | positioned facing the said suction inlet, It is characterized by the above-mentioned.

  According to this structure, the gas which consists of air or a vapor | steam in a heating chamber flows in into a circulation duct from a suction inlet by the drive of a centrifugal fan. The gas flowing through the circulation duct is heated by the heater, and blown out from the outlet into the heating chamber. Thereby, a cooking item is cooked by heating. In the centrifugal fan, the suction side is disposed opposite to the suction port, and the gas flowing in from the suction port in the axial direction of the centrifugal fan collides with a disk facing the suction port and is guided in the radial direction.

  Moreover, the present invention is characterized in that, in the cooking device configured as described above, the disk is larger than the opening of the suction port.

  Moreover, the present invention is characterized in that, in the cooking device configured as described above, the connecting portion connects an end face on the suction side of the blade and is disposed outside the opening of the suction port. According to this configuration, collision between the gas flowing into the centrifugal fan from the suction port and the connecting portion is avoided.

  According to the present invention, the centrifugal fan has a resin blade part integrally formed by connecting a plurality of blades at the connection part and a metal disk, and is engaged with the plurality of engagement holes provided in the disk. The blades are attached to the disk by engaging the claws. As a result, the assembling work can be simplified to reduce the cost, and the variation in assembling accuracy can be reduced. Further, since the blade is made of resin, a complicated shape can be easily formed, and the metal disk can be small and ensure the strength in the axial direction.

  In addition, since the engaging claw is formed with a width smaller than the engaging hole in the radial direction, even if the temperature of the centrifugal fan mounted on the heating cooker rises, the difference in thermal expansion between the disk and the blade is absorbed. Thus, the engaged state can be maintained. Accordingly, it is possible to prevent the disc and the blade portion from being detached due to thermal expansion, and to prevent the centrifugal fan from being deformed, thereby improving the reliability of the centrifugal fan.

Front sectional drawing which shows the heating cooker of embodiment of this invention The block diagram which shows the structure of the heating cooker of embodiment of this invention. The top view which shows the circulation fan of the heating cooker of embodiment of this invention The top view which shows the disc of the circulation fan of the heating cooker of embodiment of this invention Sectional drawing which shows the principal part of the circulation fan of the heating cooker of embodiment of this invention The top view which shows the principal part of the circulation fan of the heating cooker of embodiment of this invention

  Embodiments of the present invention will be described below with reference to the drawings. Drawing 1 is a front sectional view showing the cooking-by-heating machine of one embodiment. The heating cooker 1 includes a heating chamber 20 in which a cooked product 90 is stored in the main body casing 10. The heating chamber 20 is formed in a box shape having an open front surface that is opened and closed by a door (not shown). A heat insulating material 14 is provided on the peripheral surface of the heating chamber 20, and a temperature sensor 76 is provided on the ceiling surface in the heating chamber 20.

  Protrusions 23 and 25 are provided vertically on the left wall of the heating chamber 20, and protrusions 24 and 26 are provided on the right wall at the same height as the protrusions 23 and 25. A tray 21 having a placement net 22 on which the food 90 is placed is bridged between the projections 23 and 24 and between the projections 25 and 26.

  A circulation duct 27 is provided behind the heating chamber 20. The circulation duct 27 is provided with a suction port 20a that opens in the center of the back surface of the heating chamber 20, and air outlets 20b, 20c, 20d, 20e, 20f, and 20g that open in the periphery of the back surface. A circulation fan 80 (see FIG. 2) and a heater 29 (see FIG. 2) are provided in the circulation duct 27. By driving the circulation fan 80 and the heater 29, steam or air in the heating chamber 20 flows into the circulation duct 27 through the suction port 20a, is heated, and is blown out from the outlets 20b to 20g.

  An outside air inflow duct 56 in which a cooling fan 53, a waveguide 60, and a magnetron 50 are arranged is provided below the heating chamber 20. The outside air inflow duct 56 opens the outside air flow inlet 62 on the lower surface of the main body housing 10, and the cooling fan 53 is arranged facing the outside air flow inlet 62. The magnetron 50 supplies microwaves into the heating chamber 20 through the waveguide 60. Thereby, the food 90 can be microwave-heated. The waveguide 60 is provided with an antenna 51 that is rotated by an antenna motor 52 to uniformize the microwave supplied to the heating chamber 20.

  An air supply port 57 and an exhaust port 58 are provided on the right side wall of the heating chamber 20. An air supply fan 55 is disposed at a position facing the air supply port 57 in the outside air inflow duct 56. The outside air inflow duct 56 is partitioned from the upper right part of the heating chamber 20 by the partition plate 34. An exhaust duct 72 having an opening 73 on the upper surface of the main body housing 10 is led out to the exhaust port 58. The exhaust duct 72 is provided with a humidity sensor 75 and a temperature sensor 74.

  A removable water tank 30 is disposed above the right partition plate 34 of the heating chamber 20. A water storage unit 31 is provided on the side of the water tank 30. The water storage unit 31 is connected to the water tank 30 by a communication passage 32 via a water stop valve (not shown) provided on the back side of the water tank 30, and the water in the water tank 30 flows in when the water tank 30 is attached.

  The water reservoir 31 is provided with a water level sensor 36 (see FIG. 2) that detects the water level by immersing in water flowing from the water tank 30. The water level sensor 36 has a plurality of electrodes (not shown), and detects the water level in the water level tank 30 by conduction between the electrodes.

  A steam generator 40 is provided at the upper part of the right side wall of the heating chamber 2. The steam generating device 40 is provided with a steam generating heater 42 in a metal housing 41. A water supply pipe 33 led out from the water storage unit 31 is connected to the housing 41, and a discharge port 44 facing the heating chamber 2 is opened.

  Water is supplied from the water storage section 31 into the housing 41 by driving a water supply pump 35 provided in the path of the water supply pipe 33. The water in the housing 41 is evaporated by the heating of the steam generating heater 42, and the steam is discharged from the discharge port 44 into the heating chamber 2. Thereby, the cooked product 90 can be cooked with saturated steam or superheated steam.

  FIG. 2 is a block diagram showing the configuration of the heating cooker 1. The heating cooker 1 has a control unit 2 that controls each unit. The control unit 2 includes a circulation fan 80, a heater 29, a cooling fan 53, an air supply fan 55, a magnetron 50, an antenna motor 52, a water supply pump 35, a steam generation heater 42, temperature sensors 76 and 74, a humidity sensor 75, and a water level sensor. 36, the operation part 3, the display part 4, and the memory | storage part 5 are connected.

  The operation unit 3 is provided on a door (not shown) of the main body housing 10 and performs a cooking menu selection operation and the like. The display unit 4 is composed of a liquid crystal panel or the like provided on a door (not shown) of the main body housing 10 and displays selection items by the operation unit 3, cooking progress, notification contents to the user, and the like. The storage unit 5 includes a ROM, a RAM, and the like. The storage unit 5 stores an operation program of the cooking device 1, a cooking menu database, and the like, and temporarily stores calculations by the control unit 2.

  FIG. 3 shows a plan view of the circulation fan 80. The circulation fan 80 is a centrifugal fan, and sucks in the axial direction from the suction port 20a to guide the airflow radially outward. The circulation fan 80 has a disk 81 made of metal such as stainless steel and a blade portion 82 made of a resin molded product. The blade portion 82 is integrally formed by connecting a plurality of radially disposed blades 83 with an annular connecting portion 84. Each blade 83 is arranged rearward with respect to the rotation direction A, and the circulation fan 80 is a turbo fan.

  The connecting portion 84 connects the end faces of the blades 83 on the suction port 20a side, and is arranged outside the suction port 20a with a diameter larger than that of the suction port 20a. Thereby, the fall of the ventilation efficiency by the airflow taken in from the suction inlet 20a colliding with the connection part 84 can be avoided. In addition, although the connection part 84 may be provided in the intermediate | middle of the axial direction of the blade | wing 83, or a root, providing in the front-end | tip at the side of the inlet 20a is more desirable. Thereby, while being able to shape | mold the blade part 82 easily, the collision with the air current guided to radial direction and the connection part 84 can be avoided.

  The disc 81 covers one surface of the blade portion 82 opposite to the suction port 20a in the axial direction, and is formed to have a larger diameter than the suction port 20a. Thereby, the fall of the ventilation efficiency by the airflow which flows into the axial direction from the suction inlet 20a leaks behind the circulation fan 80 can be prevented.

  FIG. 4 shows a plan view of the disc 81. A mounting hole 81 a is provided at the center of the disc 81 to be inserted through the motor shaft of the circulation fan 81. Further, the disc 81 is provided with a plurality of engagement holes 81b on a plurality of concentric circles.

  FIG. 5 shows a cross-sectional view in the circumferential direction of the blade 83 portion of the circulation fan 80. An engagement claw 83 a having an L-shaped cross section is provided on the bottom surface of the blade 83. The engaging claw 83a is inserted into the engaging hole 81b and engages with the engaging hole 81b by rotating the blade portion 82 in the direction opposite to the rotation direction A of the circulation fan 80. Thereby, the disc 81 and the blade | wing part 82 are integrated.

  Further, the engaging claw 83a is bent in the direction opposite to the rotation direction A, and the disk 81 to which the motor shaft is coupled is driven in the rotation direction A when the circulation fan 80 is driven. Thereby, detachment | leave with the engaging hole 81b and the engaging claw 83a is prevented. When the motor shaft of the circulation fan 80 is connected to the blade portion 82, the engagement claw 83a may be bent in the rotation direction A in the opposite direction to the drawing.

  FIG. 6 is a plan view showing details of the engagement hole 81b portion on the outer side of the disc 81. As shown in FIG. A radial width W2 of the engaging claw 83a is formed smaller than a radial width W1 of the engaging hole 81b. Thereby, the engaging claw 83a has a play in the radial direction and engages with the engaging hole 81b.

  Since the gas flowing through the circulation duct 27 (see FIG. 1) is at a high temperature, the resin blade portion 82 is larger in thermal expansion than the metal disk 81. At this time, the engagement state between the engagement claw 83a and the engagement hole 81b is maintained, and deformation of the circulation fan 80 due to the engagement claw 83a coming into contact with the radial end surface of the engagement hole 81b by play is prevented. Can do. Thereby, the circulation fan 80 can maintain the stable ventilation state. Since the engagement hole 81b is inserted with the L-shaped engagement claw 83a, the engagement claw 83a engages with the engagement hole 81b with play in the circumferential direction.

  Further, the radial width W1 of the outer peripheral engagement hole 81b is formed larger than the width W1 '(see FIG. 4) of the inner peripheral engagement hole 81b. The difference in thermal expansion between the blade 82 and the disk 81 due to the temperature rise is smaller on the inner peripheral side than on the outer peripheral side. For this reason, the deformation of the circulation fan 80 can be prevented even if the width W1 'of the engagement hole 81b on the inner peripheral side is reduced to reduce the play with the engagement claw 83a. Thereby, the strength reduction of the disk 81 can be prevented.

  When cooking with microwaves (range cooking) is started in the heating cooker 1 having the above configuration, the magnetron 50 and the antenna motor 52 are driven. Further, the cooling fan 53 and the air supply fan 55 are driven. A microwave is supplied into the heating chamber 20 via the waveguide 60 by the magnetron 50, and the cooked product 90 is microwave-heated.

  Outside air flows into the outside air inflow duct 56 through the outside air inlet 62 by the cooling fan 53. The outside air that has flowed into the outside air inflow duct 56 is heated by cooling the magnetron 50, and is supplied to the heating chamber 20 from the air supply port 57 by the air supply fan 55. The air in the heating chamber 20 flows into the exhaust duct 72 through the exhaust port 58 due to the supply from the supply port 57 and is released to the outside through the opening 73 on the top surface.

  When steam is generated from the cooked product 90 by microwave heating and the inside of the heating chamber 20 reaches a predetermined humidity, the end time of cooking is determined by detection of the humidity sensor 75. Thereby, cooking by a microwave is complete | finished. Moreover, cooking is interrupted when the abnormally high temperature in the heating chamber 20 is detected by the temperature sensors 74 and 76.

  When cooking with hot air (oven cooking) is started, the circulation fan 80 and the heater 29 are driven. The air in the heating chamber 20 flows into the circulation duct 27 from the suction port 20a. At this time, the air flowing in the axial direction from the suction port 20 a into the circulation fan 80 collides with the disk 81 and is guided radially outward by the blades 83.

  The air flowing into the circulation duct 27 is heated by the heater 29 and blown out from the outlets 20b to 20g. Thereby, the air in the heating chamber 20 is circulated while being maintained at a predetermined temperature, and the cooked product 90 is cooked. When the timer 6 detects that the cooking time has elapsed, cooking ends. Moreover, cooking is interrupted when an abnormally high temperature in the heating chamber 20 is detected by the temperature sensor 76.

  When cooking with steam (steam cooking) is started, the water level in the water tank 30 is detected by the water level sensor 36. When the amount of water in the water tank 30 is not insufficient for cooking, the steam generating heater 42 and the water supply pump 35 are driven. Thereby, the water in the water storage unit 31 is supplied into the housing 41 of the steam generator 40 at a predetermined flow rate, and the steam generated by the heating of the steam generator heater 42 is supplied to the heating chamber 20.

  When the heating chamber 20 is filled with steam, the circulation fan 80 and the heater 29 are driven. The steam in the heating chamber 20 flows into the circulation duct 27 from the suction port 20a. At this time, the steam that has flowed in the axial direction from the suction port 20 a into the circulation fan 80 collides with the disc 81 and is guided radially outward by the blades 83.

  The steam flowing into the circulation duct 27 is heated by the heater 29 and blown out from the outlets 20b to 20g. Thereby, the steam in the heating chamber 20 is circulated while being maintained at a predetermined temperature, and the cooked product 90 is cooked by saturated steam or superheated steam. And when cooking time passes, the circulation fan 80, the heater 29, the feed water pump 35, and the steam generation heater 42 are stopped.

  According to the present embodiment, the circulation fan 80 has a resin blade portion 82 and a metal disk 81 that are integrally formed by connecting a plurality of blades 83 with a connecting portion 84, and is provided on the disk 81. The blade 82 is attached to the disc 81 by engaging the engaging claws 83a with the plurality of engaging holes 81b. As a result, the assembling work can be simplified to reduce the cost, and the variation in assembling accuracy can be reduced. Further, since the blade 83 is made of resin, a complicated shape can be easily formed, and the metal disk 81 can be small and ensure the strength in the axial direction.

  In addition, since the radial width W2 of the engaging claw 83a is formed smaller than the radial width W1 of the engaging hole 81b, the disk is maintained even if the circulating fan 80 mounted on the heating cooker 1 rises in temperature. The engagement state can be maintained by absorbing the difference in thermal expansion between 81 and the blade portion 82. Accordingly, it is possible to prevent the disc 81 and the blade portion 82 from being detached due to thermal expansion, and it is possible to prevent the circulation fan 80 from being deformed, thereby improving the reliability of the circulation fan 80.

  Further, since the radial width W1 of the outer peripheral engagement hole 81b is larger than the inner peripheral width W1 ′, deformation of the circulation fan 80 due to thermal expansion can be prevented and strength reduction of the disc 81 can be prevented. be able to.

  Further, since the circulation fan 80 is composed of a turbo fan, it is possible to secure a predetermined air volume by reducing the number of blades 83. Thereby, since the number of the engagement holes 81b can be reduced, the strength reduction of the disc 81 can be prevented.

  Moreover, since the suction side of the circulation fan 80 is opposed to the suction port 20a that opens to the heating chamber 20 of the heating cooker 1, a reduction in reliability due to high-temperature gas flowing into the circulation fan 80 from the suction port 20 is prevented. Can do.

  Further, since the circular plate 81 is formed to have a larger diameter than the opening of the suction port 20a, it is possible to prevent a reduction in blowing efficiency due to the airflow flowing in the axial direction from the suction port 20a leaking behind the circulation fan 80. it can.

  Moreover, since the connection part 84 connects the end surface of the suction | inhalation side of the blade | wing 83 and is distribute | arranged outside the opening of the suction inlet 20a, the ventilation efficiency by the airflow taken in from the suction inlet 20a colliding with the connection part 84 is provided. A decrease can be avoided.

  In the present embodiment, the circulation fan 80 formed of a centrifugal fan is mounted on the heating cooker 1, but may be mounted on other devices. At this time, if the circulation fan 80 is mounted on a high-temperature device, a greater effect can be obtained.

  According to this invention, it can utilize for a centrifugal fan and a heating cooker using the same.

DESCRIPTION OF SYMBOLS 1 Heating cooker 2 Control part 3 Operation part 4 Display part 5 Memory | storage part 10 Main body housing | casing 20 Heating chamber 20a Suction inlet 20b-20g Outlet 21 Tray 27 Circulation duct 29 Heater 30 Water tank 31 Water storage part 35 Water supply pump 36 Water level Sensor 40 Steam generator 41 Housing 42 Steam generator heater 44 Discharge port 50 Magnetron 51 Antenna 53 Cooling fan 55 Air supply fan 56 Outside air inflow duct 57 Air supply port 58 Exhaust port 60 Waveguide 72 Exhaust duct 74, 76 Temperature sensor 75 Humidity Sensor 80 Circulation fan 81 Disk 81b Engagement hole 82 Blade part 83 Blade 83a Engagement claw 84 Connection part 90 Cooked food

Claims (6)

  A plurality of blades arranged radially and an annular connecting portion for connecting the blades; a resin blade portion; and a metal disc that covers one surface in the axial direction of the blade portion; A plurality of engaging holes are formed on the plate, and an engaging claw that is inserted and engaged with the engaging hole with a smaller width in the radial direction than the engaging hole protrudes from one end in the axial direction of the blade. Centrifugal fan characterized by   The engagement hole and the engagement claw are provided on an outer peripheral side and an inner peripheral side of the blade portion, and the radial width of the engagement hole on the outer peripheral side is made larger than that on the inner peripheral side. Item 4. The centrifugal fan according to Item 1.   The centrifugal fan according to claim 1, wherein the blade is a turbofan disposed rearward with respect to a rotation direction.   The centrifugal fan according to any one of claims 1 to 3, a heating chamber for storing a cooked product, a suction port and a blower opening that open to the heating chamber, and the suction port and the blower outlet are connected. And a circulation duct in which the centrifugal fan is disposed, and a heater provided in the circulation duct, and the centrifugal fan takes in the gas in the heating chamber from the suction port and heats it with the heater to The heating cooker which blows out from a blower outlet, The suction side of the said centrifugal fan is opposingly arranged by the said suction inlet.   The cooking device according to claim 4, wherein the disk is larger than the opening of the suction port.   The cooking device according to claim 4 or 5, wherein the connecting portion connects an end face on the suction side of the blade and is disposed outside the opening of the suction port.

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