JP4720203B2 - Centrifugal blower, air conditioner - Google Patents

Description

  The present invention relates to a centrifugal blower used in an air conditioner or the like.

  Centrifugal blowers used in conventional air conditioners are provided with an inclined portion with a constant angle until the middle of the vortex in the middle of the vortex, so that the axial distance increases, and the axial distance is constant from the middle of the vortex. Thus, the cross-sectional area is increased in proportion to the rotation angle, and the inclination angle of the inclined surface is increased. (For example, see Patent Document 1)

  Further, the spiral angle in the scroll casing is set to a specific large angle, and the axial scroll width on the discharge side is gradually enlarged from the specific position. (For example, see Patent Document 2)

Also, a spiral-shaped casing having a substantially circular suction port on at least one side surface and having a substantially rectangular discharge port on the front surface, and a centrifugal fan provided in an air passage connecting these suction port and discharge port; And the outer peripheral surface of the suction port is formed so as to be sequentially expanded from both sides of the winding start nose portion to both sides of the discharge port. (For example, see Patent Document 3)
JP-A-60-145497 (2nd page, FIG. 2) JP 64-41700 (2nd page, Fig. 1) JP-A-9-287756 (2nd to 3rd pages, FIG. 1)

  The conventional centrifugal blower has a radius R that has been increased from the height of the casing, and the casing has an enlarged shape extending from the tongue to the air outlet 4 in order to reduce operating noise and improve blowing performance. There is a problem that it is necessary to ensure a large expansion of the casing radius R, and the casing height is also increased.

  Further, by setting a region where the casing radius R is constant from the tongue to the rotation direction of the multi-blade fan, and by making the ratio of the casing expansion start radius and the casing expansion end radius equal, However, there has been a limit to achieving further performance improvement and downsizing.

  The present invention has been made to solve the above-described problems, and this object is to provide a centrifugal fan used in a combination of at least one or more installed in a limited space in a more compact shape and a required air volume. This ensures a casing shape that can suppress operating noise.

The centrifugal blower according to the present invention is a centrifugal blower having a multiblade fan , wherein a radial direction from the center of the multiblade fan to a radial casing in a casing shape starts from a straight line connecting the center of the multiblade fan and a tongue portion. The distance is equal to the tongue distance between the center of the multi-blade fan and the tongue in the direction of rotation of the multi-blade fan , and the axial end face of the multi-blade fan and the air suction port to the multi-blade fan are provided. A first section that is a constant section in which an axial distance between the formed casing side face is equal to a distance between the axial end face of the multi-blade fan and the casing side face at the tongue portion , and continuous to the first section Then, the second section is a section in which the radial distance increases spirally starting from the first section end point and the axial distance increases in accordance with the rotation angle.

The centrifugal blower of the present invention is a centrifugal blower having a multiblade fan , wherein a radial distance from the center of the multiblade fan to a radial casing in a casing shape starts from a straight line connecting the center of the multiblade fan and a tongue portion. Is equal to the tongue distance between the center of the multi-blade fan and the tongue in the direction of rotation of the multi-blade fan , and forms an axial end surface of the multi-blade fan and an air intake port to the multi-blade fan. A first section that is a constant section in which an axial distance between the casing side surface and the axial end surface of the multi-blade fan is equal to a distance between the casing side surface of the tongue , and the first section. Since the radial distance is spirally expanded starting from the first section end point, and the second section is a section in which the axial distance increases according to the rotation angle, the installation space is limited. It is possible to improve the blowing performance by securing the air path area without enlarging the casing height has the effect that can be achieved also miniaturization of the centrifugal blower.

Embodiment 1 FIG.
1 is a side structural view showing a centrifugal fan according to Embodiment 1 of the present invention, and FIG. 2 is a longitudinal sectional view showing the centrifugal fan according to Embodiment 1 of the present invention. In the figure, the centrifugal blower main body 1 includes a multi-blade fan 4 supported by a fan shaft 3 by a central partition plate 2, has a shape that expands in the radial direction and the axial direction, and smoothes the air flow. Are formed of one or more air inlets 6 forming the bell mouth 5 and a fan casing body 9 having an air passage 8 formed by the air outlet 7. The fan casing body 9 has a tongue portion whose radial distance shown in the drawing is rotated at least 90 ° or more from the linear shaft 10a connecting the center of the multi-blade fan 4 and the tongue portion 10 in the direction in which the multi-blade fan 4 rotates. The first section side plate 11 which is a fixed section determined by θ0 equal to the distance, and the casing circumference that expands in a spiral shape starting from the first section side plate end point 11a continuously to the first section side plate 11 A second section side plate 12 that is determined by θ1 that expands in the axial direction in accordance with the rotation angle of the direction, and a casing that expands in the radial direction continuously from the second section side plate 12 and starting from the second section side plate end point 12a. It is formed by a third section side plate 14 having a straight line portion 13 that is in contact with the circumference of 9 and connected to the air outlet 7.

  The first section side plate 11 axial width A of the casing body 9 and the third section side plate 14 axial width B after being expanded in the axial direction have a relationship of A <B.

Next, the operation of the centrifugal blower according to Embodiment 1 will be described.
In the centrifugal blower according to the first embodiment configured as described above, when the multiblade fan 2 is driven in the rotational direction 15, the inside of the multiblade fan 4 becomes negative pressure, and the flow of air sucked from the air suction port 6 is first. The direction 8a flows in, and the air flow second direction 8b is changed to the outer periphery of the multiblade fan 4. The third direction 8c of the air flow whose direction is changed increases the wind speed from the tongue 10 toward the multiblade fan rotation direction 15 and is blown to the air outlet 7.

  This means that when the conventional centrifugal blower and the casing width A and the casing height C have the same dimensions, the casing internal effective air passage cross section 16 on the air blowing side increases the casing width A and increases the area. In the case of the same air volume, it means that the wind speed can be reduced and the dynamic pressure can be suppressed.

  Moreover, when it is set as the axial direction expansion casing which the casing internal effective air path cross section 16 becomes the same, it means reducing casing height L2 without inferior ventilation performance.

  As described above, a constant section in which the radial distance of the casing shape is equal to the tongue portion distance, and a constant section having a section that spirally expands and the axial distance is equal to the distance between the tongue casing side surfaces; By having both sections where the distance increases according to the rotation angle, it becomes possible to construct a centrifugal fan that is smaller than ever, and in a limited space of an air conditioner in which the centrifugal fan is mounted. Makes it possible to make more effective use of effects such as low noise and increased air volume.

  Further, in another example in the first embodiment, the casing shape axial expansion start angle θ0 is set to an arbitrary position, but the same effect is secured when the air suction position is limited next. Another example of the first embodiment will be described. It is an adjacent figure of the centrifugal blower in the other example of Embodiment 1 of this invention. FIG. 3 shows an air suction direction a as an example. In the situation where a plurality of centrifugal blowers 1 shown in FIG. 3 are arranged close to each other, the air suction air passage 8d is narrowed from the tongue 10 toward the air outlet 14 by enlarging the casing body 9 in the axial direction. A situation occurs.

  In the above case, the axial expansion start angle θ0 of the casing is set near the air suction direction a (for example, θ0 ≧ 90 °) rather than the vicinity of the tongue portion 10, and a certain section 14 in which the axial direction of the casing does not expand is secured. To do.

  As described above, particularly when a plurality of adjacent centrifugal fans are used, the increase in suction air pressure loss is minimized by securing the casing axial expansion start angle θ0 of 90 ° or more according to the air suction port. It is possible to obtain the same effect as in the first mode.

Embodiment 3 FIG.
Another example in the first embodiment will be described. The case where a casing is comprised with several components is demonstrated. 4 is a side structural view showing another centrifugal fan according to Embodiment 1 of the present invention, and FIG. 5 is a cross-sectional view showing a plurality of other centrifugal fans according to Embodiment 1 of the present invention.

  In the figure, the centrifugal blower main body 1 includes a multi-blade fan 4 supported by a fan shaft 3 by a central partition plate 2, has a shape that expands in the radial direction and the axial direction, and smoothes the air flow. Are formed of one or more air inlets 6 forming the bell mouth 5 and a fan casing body 9 having an air passage 8 formed by the air outlet 7. The fan casing main body 9 rotates at least 180 ° or more in the direction in which the multiblade fan 4 rotates, with the radial distance shown in the figure starting from a linear shaft 10a connecting the center of the multiblade fan 4 and the tongue 10. Up to the dividing surface 16a, a fourth section side plate 17 that is a constant section determined by θ2 equal to the tongue distance, and a spiral that starts from the fourth section side plate end point 17a continuously to the fourth section side plate 17 A fifth section side plate 18 determined by θ3 that expands in the shape of the casing and expands in the axial direction according to the rotation angle in the circumferential direction of the casing, and a fifth section side plate end point 18a that is continuous with the fifth section side plate 18 In addition, it is formed of a sixth section side plate 19 having a straight portion 13 that is parallel to the fourth section side plate end point 16a that is the dividing surface and is connected to the air outlet 7.

  When a plurality of other centrifugal blowers of the first embodiment are arranged close to each other and the air suction possible range is wider, in order to secure a larger amount of air, the air suction air passage 8e is expanded to the dividing surface 16a, It is possible to obtain an effect similar to that of the first embodiment or other embodiments while minimizing an increase in the pressure loss of the intake air.

  Further, an example in which the centrifugal blower in the first embodiment or the other example of the first embodiment is incorporated in an air conditioner will be described. FIG. 6 is a side view showing an example in which the centrifugal blower according to the present invention is mounted on an air conditioner, FIG. 7 is a plan view showing the main part of the centrifugal blower according to the present invention mounted on an air conditioner, and FIG. It is a rear view which shows the principal part which mounted the air blower in the air conditioner.

  In the figure, the air conditioner body 20 has a component structure that is closed as an air passage 8 except for an air inlet and an outlet (both not shown). It has at least one multi-blade fan 4 and a casing 9 similar to the first embodiment, and includes a fan motor 4a for driving the multi-blade fan 4, a shaft 3 for transmitting power, and a bearing portion. 3a and the like, and an air suction port is provided on the lower surface 21a or the rear surface 21b of the blower chamber portion 21 forming the air conditioner 20. Further, the air suction side air passage 20a and the blowout side air passage 20c are divided on the front surface of the blower chamber portion 21 forming the air conditioner 20 to partition the heat exchanger chamber portion 23 in which the heat exchanger 22 is arranged. A partition plate 24 is provided, and is provided with a drain pan 25 on the lower surface of the heat exchanger 22 and a wind direction vane 26 that discharges air after heat exchange of the blowing side air passage 20c, for example, a ceiling installation surface 27. Used fixed to. The air conditioner 20 is mainly used as an indoor unit, and is used in combination with an outdoor unit.

  Next, the operation of an example in which the centrifugal fan according to the present invention is mounted on an air conditioner will be described. The suction side air passage air 20a is sucked from the lower surface 21a or the rear surface 21b of the air conditioner 20 in which the air suction port is installed. The air is blown out from the casing 9 to the heat exchanger 22 through the centrifugal blower 1 as shown in the air flow path 20b. The air passing through the heat exchanger 22 is cooled via the refrigerant in the cooling operation, and is overheated in the heating operation to cause a temperature change. The air with the temperature change is adjusted in the blowing direction by the wind direction vane 26, and air conditioning is realized by the air flow 20c. Further, during the cooling operation, the drain generated from the air cooled by the heat exchanger 22 is transmitted through the heat exchanger 22 and accumulated in the drain pan 25 and has a function of being discharged to the outside of the air conditioner 20.

  In the air conditioner having the centrifugal blower as described above, this centrifugal blower is used in a plurality of arrangements that are continuous in the axial direction, and when the air intake port of the air conditioner is orthogonal to the axial direction, adjacent casings are used. By securing the suction side air passage area in the meantime, it is possible to suppress the pressure loss of the suction, and to achieve an increase in the air volume by increasing the casing blowout area.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side structure figure which shows the centrifugal blower in Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the centrifugal blower in Embodiment 1 of this invention. It is a longitudinal cross-section adjacent view which shows the centrifugal blower in other forms of Embodiment 1 of this invention. It is a side structure figure which shows the centrifugal blower in the other form of Embodiment 1 of this invention. It is a longitudinal cross-section adjacent view which shows the centrifugal blower in other forms of Embodiment 1 of this invention. It is a schematic sectional drawing which shows the air conditioner carrying the centrifugal blower in Embodiment 1 of this invention. It is a top view which shows the principal part which mounted the centrifugal air blower in Embodiment 1 of this invention in the air conditioner. It is a rear view which shows the principal part which mounted the centrifugal blower in Embodiment 1 of this invention in the air conditioner.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Centrifugal blower, 2 Center partition plate, Casing, 3 axis | shaft, 4 multiblade fan, 5 bell mouth, 6 Air inlet, 7 Air outlet, 8 Air path, 8a Air flow 1st direction, 8b Air flow Second direction, 8c Air flow third direction, 9 Casing body, 10 tongue, 10a linear axis, 11 first section side surface, 11a first section end point, 12 second section, 12a second section end point, 13 straight section , 14 3rd section, 15 Multi-blade fan rotation direction, 16 Casing internal effective air path cross section, 17 4th section, 17a 4th section end point, 18 5th section, 18a 5th section end point, 19 6th section, 20 Air Harmonic machine, 21 Blower chamber, 21a Blower chamber lower surface, 21b Blower chamber rear, 22 heat exchanger, 23 heat exchanger chamber, 24 partition plate, 25 drain pan, 26 wind direction vane, 27 Ceiling installation surface.

Claims (4)

In a centrifugal blower having a multiblade fan, a radial distance from the center of the multiblade fan to a radial casing in a casing shape is a multiblade fan rotation direction starting from a straight line connecting the center of the multiblade fan and a tongue. It is equal to the tongue distance between the center of the multiblade fan and the tongue, and between the axial end surface of the multiblade fan and the casing side surface forming the air inlet to the multiblade fan. A first section that is a constant section in which an axial distance is equal to a distance between an axial end face of the multiblade fan and a casing side surface of the tongue; and a first section end point that is continuous with the first section And a second section that is a section in which the radial distance increases spirally and the axial distance increases according to the rotation angle. The position where the distance between the axial end face of the multiblade fan and the casing side surface starts to expand in the axial direction starting from the end point of the first section of the casing shape is a straight line connecting the center of the multiblade fan and the tongue. The centrifugal blower according to claim 1, wherein the centrifugal fan is at a position rotated at least 90 ° or more in the direction in which the multiblade fan rotates from the starting point. It has the 3rd section which is a fixed section which has a straight part connected to a blower outlet in contact with the end of the 2nd section following the 2nd section of the casing shape, and the axial direction distance does not increase. The centrifugal blower according to claim 1. An air conditioner comprising the centrifugal blower according to any one of claims 1 to 3.

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