JPH10159789A - Cross-flow fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cross-flow fan which is embodied in a small size, can make uniform blowing to a wire area, and in which drop of the air quantity at each end is suppressed satisfactorily. SOLUTION: At least one of the air quantity determining factors for the air blowing out of a blow-in hole 11 toward a blow-out hole 12 is set as swung so that the air quantity is incremental at the two ends compared with the setting for the central part of a rotor 8, wherein the mentioned factors include the angle of blades 17, number of blades, thickness, the passage spacing between a guide 14 and the rotor 8, distance from an air scratch-off part 15 at the blow- out hole 12 to the rotor 8, and the outside diameter of the rotor 8. The blow-out quantity at the two ends of the rotor 8 is arranged incremental till that of the central part according to the normal design.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross flow fan, and is used, for example, for cooling and exhausting in an OA apparatus such as a copying machine.

[0002]

2. Description of the Related Art Conventionally, cross flow fans have been used for blowing air to a wide range. In a copying machine, for example, it is used to cool a platen glass on which a document is placed.

[0003] The cross flow fan is long in the axial direction to blow air to a wide range. As shown in FIG. 8, a conventional cross-flow fan has a rotor b having a number of blades a disposed around a rotation axis x, a suction port c for allowing external air to be involved in the rotation of the rotor b, and a rotor b. A guide portion d for guiding the air entrained and accompanying the air in a wind path along the outer periphery of the rotor b, and a scraping portion i for scraping off air that is swept away in the rotation direction of the rotor b along the air passage. When the rotor b is driven to rotate by the motor h connected thereto, the external air is sequentially swept by each blade a of the rotor b through the entire suction port c. It is engulfed in the whole area in the longitudinal direction of the rotor b.
The air entrained in the rotor b is swept in the direction of rotation of the rotor b along the air path formed by the guide portion d along with the rotation of the rotor b, reaches the outlet e, and the scraping portion of the outlet e. It is scraped off by i and is blown out from the whole area of the outlet e, and is blown over a wide range.

[0004]

However, in the above-mentioned conventional cross-flow fan, the air volume distribution becomes dense at the center, and drops occur at both ends. In the conventional example shown by the broken line A in FIG. 5, only about 70% of the air volume is obtained at both ends as compared with the central part. For this reason, in the conventional cross-flow fan, the amount of air blown at both ends is insufficient with respect to the center portion, and when the purpose is to cool platen glass or the like, the temperature of the portion to be cooled corresponding to both ends of the cross-flow fan increases. There is a problem.

Conventionally, to compensate for this, a louver is provided in an air passage such as a duct to correct the air flow distribution, or the size of the fan itself is increased to ensure the air flow at both ends. Louvre design and installation is difficult and costly. In addition, when the size of the fan is increased, the size and cost are increased, and the air volume in the central portion becomes excessive, which may cause a problem.

[0006] The inventors of the present invention have conducted various experiments on the drop of the air flow at both ends of the cross flow fan, and have considered that there are various factors related to the air flow in the structure of the cross flow fan. Regardless of the non-uniformity of the cross-flow fan, it was found that the design was made uniform in the longitudinal direction of the cross-flow fan.

[0007] An object of the present invention is to provide a cross-flow fan capable of sufficiently reducing the drop at both ends of the air volume, and having a small size and capable of evenly and uniformly blowing air over a wide range based on the above findings. is there.

[0008]

According to a first aspect of the present invention, there is provided a cross flow fan comprising: a rotor having blades arranged around a rotation axis; and external air being entrained in rotation of the rotor. A suction port, a guide portion for guiding air entrained in the rotor along an air path along the outer periphery of the rotor, and scraping air that is swept away in the direction of rotation of the rotor along the air path and externally. A casing having an outlet for blowing out to the outside, the blade angle, the number, the thickness, the passage interval between the guide portion and the rotor, the distance between the air scraping portion of the outlet and the rotor, the rotor At least one of the airflow-related elements, such as the outer diameter of the airflow, related to the airflow blown from the suction port toward the blowout port, has a smaller airflow at both ends compared to the setting at the center of the rotor. It is characterized in that the set waving on the side large.

In such a configuration, when the rotor is driven to rotate, the rotor is sequentially swept by the blades of the rotor through the entire suction port by the blades of the rotor and is rolled along with the entire area in the longitudinal direction of the rotor, thereby forming a guide portion. The air that has been swept away in the direction of rotation of the rotor along the air path and reached the outlet is blown out from the entire area of the scraper by the scraper of the outlet, and blown over a wide range, but the angle, number and thickness of the blades , The passage distance between the guide part and the rotor,
At least one of the air volume-related elements, such as the distance between the air scraping portion of the air outlet and the rotor, the outer diameter of the rotor, and the like related to the air volume blown from the air inlet toward the air outlet, is provided at the center of the rotor. The airflow at both ends of the rotor is increased as compared to the case where the airflow is increased at both ends compared to the setting, and the same setting as the central part which is usually designed as in the past is set. As a result, the difference between the air volume at the center and the air volume at the center can be eliminated, so that the air volume distribution between both ends of the rotor and the center can be made uniform without excess and deficiency, and the air blowing and cooling over a wide range become uniform as set. In addition, the size and cost of the crossflow fan are not particularly increased.

According to a second aspect of the present invention, in the first aspect of the present invention, a partition plate is further provided at a blade portion at a boundary position where the setting of the airflow-related element in the rotor can be changed.

In such a configuration, in addition to the first aspect of the present invention, the blade portion at the boundary position where the setting of the airflow-related elements at the center and both ends of the rotor can be changed is partitioned by the partition plate. The movement of the air between both ends and the central portion of the blade whose setting of the air flow rate-related element is changed can be prevented, and the increase of the air flow at the end can be easily guaranteed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) In Embodiment 1, as shown in FIG. 4, a platen glass 2 provided on a scanning optical system 1 of a copying machine and having a large area on which an original is placed is cooled. 3 shows the case of the cross flow fan 3 used for the above. The first slider 4, which is a scanner of the scanning optical system 1, moves in the direction of the arrow 5 to sequentially illuminate the scanning position of the original by the lamp 6 each time the original is scanned. The temperature is high during continuous copying of many sheets. The cross flow fan 3 is provided at one end of the scanning optical system 1 in the copying machine to cool the heated platen glass 2 and is driven to rotate by, for example, a directly connected motor 7 each time a copying operation is performed.

As shown in FIGS. 1 and 4, the cross flow fan 3 includes a rotor 8 attached to a rotating shaft 7a of a motor 7, an inlet 11 and an outlet 12 around the rotor 8, and a Guide 1 for forming air path 13
4, and a casing 16 forming a scraping portion 15 for scraping off the air flow accompanying the rotor 8 at the outlet 12 and blowing the airflow to the outlet 12.

As shown in FIGS. 1 to 3, the rotor 8 is provided with a number of blades 17 around the rotation axis X, and is provided at both end plates 21 attached to the rotation shaft 7a and at several points in the longitudinal direction. And supported by the blade partition plate 22. In the first embodiment, the blade 17 of the rotor 8 is partitioned by the blade partition plate 22 into five parts in the longitudinal direction, and the blade 17 in each of three central parts is shown in FIG. As shown in FIGS. 1 and 2, (b) of FIG. 1 and FIG.

When the rotor 8 is driven to rotate by the motor 7, the external air is sequentially swept by the blades 17 through the entire suction port 11, and is taken into the entire region in the longitudinal direction of the rotor 8 to accompany the rotor 8. The air that accompanies the rotor 8 flows along the air path 13 formed by the guide portion 14 along the arrow 3 of the rotor 8.
It is swept away in the rotation direction indicated by 1 and heads toward the outlet 12. The air that has reached the outlet 12 is scraped off by the scraper 15 of the outlet 12 and is blown out from the entire area of the outlet 12 to be blown over a wide range corresponding to the length of the rotor 8 in the rotation axis direction.

If the number of arranged blades 17 increases even if the outer diameter of the rotor 8 is the same, the amount of external air that is swept into the suction port 11 and the function of pushing the air into the blowout port 12 increase. The amount of air blown out increases. In other words, the number of blades 17 arranged is
This is one of the airflow-related factors involved in the airflow, and the airflow can be increased or decreased by increasing or decreasing the number of blades 17.

In the first embodiment, the number of blades 17 in each divided portion on each side of the rotor 8 by the blade partition plate 22 is larger than the number of blades 17 in the central three divided portions. Since the air volume at both ends of the rotor 8 can be increased as compared with the conventional case where the number of airflows is the same as that of the central portion and the difference in air volume from the central portion can be eliminated, the air volume at both ends and the central portion of the rotor 8 can be reduced. The distribution can be made uniform without excess and deficiency, and air blowing and cooling over a wide range become uniform as set. In addition, there is no increase in the size of the cross flow fan 3 or increase in cost.

Therefore, the blade 1 at the center of the rotor 8
The number of arrangements of 7 is set to the standard number of arrangements obtained in the normal design, and if the number of blades 17 at both ends is increased to the number of arrangements that can compensate for the air volume insufficient in the normal design, uniform air supply and cooling can be performed within the excess and shortage. .

The cross flow fan 3 according to the first embodiment
5 shows a characteristic as shown by a solid line B in FIG. 5, and is a substantially uniform distribution at a design air flow of almost 100%.

Moreover, as in the first embodiment, the blades 17 at the boundary positions where the setting of the airflow-related elements such as the number of blades 17 at the center and both ends of the rotor 8 can be changed.
Is separated by the blade partition plate 22, the movement of air between both ends and the center of the blade 17 in which the setting of the airflow-related element of the rotor 8 is changed is prevented, and An increase in the air volume can be easily guaranteed.

The rotor 12 is effective if it is divided into three or more. Also, as in the first embodiment, 5
When the number of blades 17 is more than the division, the number of blades 17 may be designed to increase sequentially as the position moves from the center division to the end division, so that the air volume can be stretched more finely. In short, the blades 1 at both ends rather than the center
The number of sheets 7 need only be large, and the blowing efficiency can be improved up to about 30 sheets.

In addition to the number of blades 17 arranged,
7, the distance between the passage between the guide portion 14 and the rotor 8, the distance between the air scraping portion 15 of the outlet 12 and the rotor 8, the outer diameter of the rotor 8, and the like also contribute to the increase and decrease of the air volume. It is an airflow-related element, and the airflow increases as the angle of the blade 17 with respect to the direction of the tangent to the rotor 8 increases, and if the thickness of the blades 17 is reduced even if the number of blades 17 is the same, the amount of external air scraped by the blades 17 increases. The airflow increases. As the passage interval between the guide portion 14 and the rotor 8 in the air passage 13 increases, the air volume increases. As the distance between the air scraper 15 of the outlet 12 and the rotor 8 is reduced, the amount of air scraped by the scraper 15 increases, and the amount of air blown out increases.

Therefore, the air flow distribution can be made uniform by changing at least one of the various air flow-related elements, not limited to the number of blades 17 arranged in the first embodiment, and two or more air flow-related elements can be used. Alternatively, they can be designed so that the air volume distribution is made uniform by their combined actions.

(Embodiment 2) This embodiment 2 is shown in FIG.
As shown in (a) and (b), the number of blades 17 at the central portion and both end portions is unified to, for example, 12 which can be obtained by a normal design, and the blades 17 at three central divided portions of the rotor 8 are formed.
The inclination of the blade 17 was set to 45 ° obtained by the normal design as shown in FIG. 6A, and the inclination of the blade 17 at the divided portion at each end was set to 60 °. Thereby, the air volume distribution of the blown air becomes uniform without excess and deficiency as in the case of the first embodiment shown by the solid line B in FIG. In addition, there is an advantage that the structure of the cross flow fan 3 is not complicated and the cost is not increased at all.

Since other structures are the same as those of the first embodiment, the same members are denoted by the same reference numerals, and overlapping description and illustration are omitted.

(Embodiment 3) In Embodiment 3, as shown in FIG.
The shape of the guide portion 14 is changed between the center portion and both end portions so that the interval between the guide portion 14 and the center portion is S2 as compared with the center portion which is S1 as normally designed. Thereby, the suction port 1
1 to the blade 17 of the rotor 8
, The amount of air to be blown toward the end can be made larger at both ends than at the center. Further, in the third embodiment, the shape of the scraping portion 15 is changed to the center portion so that the distance between the scraping portion 15 and the rotor 8 is narrower at both ends S4 compared to the center portion S3 as normally designed. And at both ends. As a result, the amount of air entrained by the blade 17 and scraped off and blown out to the blow-off opening 12 is increased at both ends as compared with the central portion, and the distribution of the blown-out air amount becomes uniform in the longitudinal direction. You can do so.

With these arrangements, the amount of air blown out at both ends can be made larger than the amount of air blown out of the central portion of the cross flow fan 3 by the usual design, so that the air flow distribution over the entire cross flow fan 3 is excessive. Can be uniform without shortage. It should be noted that the cross flow fan 3 is not particularly increased in size or cost. However, even with only one of the measures of the guide portion 14 and the scraping portion 15, it is possible to eliminate the difference in the distribution of the blown air volume.

Since other configurations are the same as those in the first embodiment, the same members are denoted by the same reference numerals, and overlapping drawings and descriptions are omitted.

[0030]

According to the first aspect of the present invention, at least one of the airflow-related elements is set so that the airflow increases at both ends as compared with the setting at the center of the rotor. It is possible to eliminate the difference between the air volume at the central portion and the air volume at the both ends of the rotor by increasing the air volume at both ends of the central portion as compared with the case where the air volume at the central portion is usually set to the same value as the conventional one. The air volume distribution can be made uniform without excess and deficiency, and air blowing and cooling over a wide range become uniform as set. In addition, the size and cost of the crossflow fan are not particularly increased.

According to the second aspect of the present invention, in addition to the first aspect of the present invention, the movement of air between both end portions and the center portion of the blade in which the setting of the airflow-related element of the rotor is changed is prevented. In addition, it is possible to easily guarantee an increase in the air volume at the end.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a cross flow fan according to a first embodiment of the present invention.

FIGS. 2A and 2B are cross-sectional views of a rotor of the cross-flow fan in FIG. 1, in which FIG.
Is a cross-sectional view of both ends.

FIG. 3 is a perspective view of a rotor of the cross flow fan of FIG. 1;

FIG. 4 is a perspective view showing a state in which the cross flow fan of FIG. 1 is used in a copying machine.

FIG. 5 shows the distribution of the blowing air volume of the cross flow fan of the first embodiment of the present invention and the conventional example, and the ratio of the actual air volume to the designed air volume.

6A and 6B are cross-sectional views of a rotor showing a cross-flow fan according to a second embodiment of the present invention, in which FIG. 6A is a cross-sectional view of a central portion, and FIG.

FIG. 7 is a longitudinal sectional view showing Embodiment 3 of the cross flow fan of the present invention.

FIG. 8 is a perspective view showing a conventional cross flow fan.

[Explanation of symbols]

 Reference Signs List 3 cross flow fan 7 motor 7a rotating shaft 8 rotor 11 suction port 12 outlet 13 air path 14 guide section 15 scraping section 16 casing 17 blade 21 both end plates 22 partition plate S1, S2 passage interval S3, S4 distance

Claims (2)

[Claims] 1. A rotor having blades arranged around a rotation axis, a suction port for allowing external air to be entrained in the rotation of the rotor, and air entrained by the entrained air being supplied to an air path along the outer periphery of the rotor. A cross-flow fan comprising: a guide portion for guiding the air through the air passage; and a casing having a blowout port for blowing the air swept away in the rotation direction of the rotor along the air path by the scraping portion and blowing the air to the outside. , Number, thickness, path spacing between the guide and rotor, distance between the air scraping part of the outlet and the rotor, outer diameter of the rotor, and the amount of air blown from the inlet to the outlet Wherein at least one of the airflow-related elements is set so that the airflow increases at both ends as compared with the setting at the center of the rotor. . 2. The cross-flow fan according to claim 1, wherein a partition plate is provided at a boundary position where the setting of the air volume-related element in the rotor can be changed.