JP2005194899A - Blower module, its manufacturing method, and electronic apparatus with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blower module which is low-cost, low-noise and has a high airflow volume supplying capacity without increasing its outside dimension such as a height and a width of a fan. <P>SOLUTION: The blower module includes a housing with an annular wall at a position spaced from the distal end of fan blades, spokes for joining a rotary driving unit arranged at the center of the fan and the housing together. A ring is arranged at a sucking side of the fan so arranged that a spoke side becomes the sucking side and is fixed to the spokes. As a result, the blower module can be realized in which a loss due to secondary flows and turbulent-flow noises can be reduced without increasing the outside dimension. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a blower.

  In recent years, high-density mounting of electric circuits has been actively used due to downsizing and digitization of devices. Along with this, the heat generation density of the electronic equipment also increases, so that a blower is used for equipment cooling.

  As shown in FIG. 7, in the conventional blower, a fan 2 having a plurality of blades 1 is rotatably arranged, and an annular wall 3 is formed at an interval from the tip of the fan. In the blowing state, the axial flow fan rotates in the direction of the rotation direction 4 around the shaft, and an air flow 5 from the suction side toward the discharge side is generated.

  However, in the above air blowing state, the speed of the air flow is increased on the back pressure side of the blade tip, and a low energy region is generated on the blade trailing edge side where this is converted into pressure energy due to the influence of the inter-blade secondary flow. This part has a large loss and is easy to cause separation of the flow, and the air flow is separated from the blade surface, and the vortex is generated in the separation region, thereby increasing the turbulent noise and deteriorating the noise level. is there.

In order to solve this problem, a method is known in which a ring is provided on the suction side of the fan in order to separate the reverse flow and suction flow from the blade tip positive pressure side and suppress vortices. (For example, see Patent Document 1)
Japanese Patent Laid-Open No. 02-005799

  However, such a method requires a sufficient ring installation area on the suction side, and in general blower devices used for cooling small electronic devices whose outer dimensions such as height and width are limited, a ring installation is required. It is not desirable to increase the size of the blower by providing the region. In addition, since the housing and ring cannot be molded integrally, the housing manufacturing method becomes complicated, such as attaching a separate ring to the housing, resulting in problems such as reduced productivity and increased manufacturing costs. Not applicable to fans.

  The present invention solves such a conventional problem, and provides a blower that has low noise, low noise, and high airflow performance without increasing the external dimensions such as the height and width of the fan. With the goal.

  In order to solve the above-mentioned problems, the present invention has a housing having an annular wall at a position spaced from the blade tip of the fan, a rotary drive unit disposed at the center of the fan, and a spoke for coupling the housing. A ring is arranged on the suction side of the fan, which is arranged so that the spoke side becomes the suction side of the fan, and this ring is fixed to the spoke.

  By the above means, the leakage flow flowing from the positive pressure side to the back pressure side of the blade tip when the fan is under pressure is separated from the suction flow, thereby reducing the loss due to the vortex flow such as the secondary flow and the turbulent flow noise. be able to. Moreover, when the above-described air blower is provided as an electronic device, for example, in a personal computer or the like, it is possible to reduce the noise and improve the cooling efficiency as the electronic device.

  The invention according to the present application for solving the above problems will be described below.

  The present invention has a housing having an annular wall at a position spaced from the blade tip of the fan, and a spoke that couples the housing to the rotary drive unit disposed at the center of the fan, and the spoke side is a suction In the structure arranged so as to be on the side, a ring is disposed on the suction side of the fan, and the ring is fixed to the spoke.

  The present invention also includes a housing having an annular wall at a position spaced from the blade tip of the fan, and a spoke for coupling the rotary drive unit disposed at the center of the fan and the housing. A ring is arranged on the suction side of the fan arranged so that the suction side is the suction side, this ring is fixed to the spoke, and a current plate is arranged between the ring and the annular wall It is the air blower characterized by being made.

  The present invention has a configuration in which the diameter d of the ring disposed on the suction side of the fan satisfies the relational expression of (Di + Do) / 2 ≦ d ≦ Do with respect to the fan outer diameter Do and the boss diameter Di.

  Moreover, the present invention is a blower characterized in that a ring and a housing arranged on the suction side of the fan are integrally formed.

  Further, in the present invention, the annular wall of the housing is cut off on the discharge side, and an air pocket portion opened on the discharge side is formed between the annular wall and the outer peripheral portion of the housing. A blower characterized by having a configuration.

  Further, according to the present invention, in the method of manufacturing a blower device when the blower device of the above invention is manufactured, the blower device is characterized in that the housing molding method is formed by a mold having only an upper core and a lower core. It is a manufacturing method.

  Moreover, this invention is an electronic device which has a ventilation apparatus of said invention.

  Among the inventions according to the present application, according to the invention according to claims 1 to 5, the reverse flow generated at the blade tip is separated from the suction flow, and the loss due to the blade tip vortex is reduced by suppressing the blade tip vortex, Loss that occurs when pressure is applied to the fan can be suppressed. As a result, the air volume-static pressure characteristics can be improved.

  Moreover, turbulent noise can be reduced by suppressing turbulent vortices due to leakage flow.

  Further, since the spoke side becomes the suction side, foreign matter can be prevented from being mixed.

  According to the fifth aspect of the present invention, when the housing is molded, since the molding can be performed only with the upper and lower molds, the production cost can be suppressed.

  Furthermore, according to the seventh aspect of the invention, it is possible to improve the cooling efficiency of the electronic device and reduce the noise.

  Embodiments of the present invention will be described below.

(Embodiment 1)
FIG. 1 is a structural diagram of a blower according to Embodiment 1 of the present invention. A fan 2 having a plurality of blades 1, a housing 6 including an annular wall 3 spaced from the blade tips of the fan 2, a motor unit 7 that rotationally drives the fan 2, and a spoke 8 that couples the housing 6, The fan 2 is arranged so that the spoke side is the suction side of the fan. A ring 9 is provided on the suction side of the fan 2, and this ring 9 is fixed to the spoke 8.

  As shown in FIG. 7, in the conventional air blower, the fan 2 is rotationally driven in the direction of the rotation direction 4 by the motor unit 7 to generate an air flow 5 from the suction side to the discharge side. However, when the fan 2 is used with pressure applied, the flow from the suction side toward the discharge side is pushed back by the pressure, and a leakage flow from the positive pressure side to the back pressure side occurs between the blade tips and the blades. Part of this flow flows back to the back pressure surface from the gap between the blade tip and the housing annular wall, and interferes with the suction flow to form the blade tip vortex 10. Also, as shown in the flat cross-sectional view across the blade in FIG. 2, when the fan 2 is pressurized, the flow rate decreases, thereby increasing the angle of attack by 11 and causing flow separation on the blade back pressure surface. . The separation flow generates inter-blade vortex 13 and turbulent flow with the next blade behind the rotation direction, or flows backward to the suction side and flows into the back side of the next blade, thereby causing stall. Such turbulence in the flow between the blades is likely to occur on the outer peripheral side of the fan having a high flow velocity, turbulent noise increases due to the stall, and the noise level and the air volume-static pressure characteristics deteriorate.

  To solve this problem, a method of providing a suction ring on the suction side to improve flow-static pressure characteristics and reducing noise is well known, but this is a cylindrical and long housing in the axial direction. It is common to apply to a fan having By confining the reverse flow between the housing and the suction ring, the reverse flow and the suction flow interfere with each other to prevent a vortex from being generated on the suction side. Therefore, the suction ring does not affect the suction flow. Thus, a certain length is required in the axial direction. Since it is such a structure, it is not applied to the small fan for electronic device cooling which has a restriction | limiting in an external dimension.

  In the embodiment of the present invention shown in FIG. 1, by making the suction side of the fan 2 in the same direction as the spoke side, the ring 9 can be provided on the suction side in the same size as the conventional blower.

  Originally, in such a small fan for cooling electronic equipment, the spokes 8 are generally arranged on the discharge side of the fan 2 as shown in FIG. This is because if there is an obstacle such as a spoke on the suction side, the suction flow collides with the spoke, resulting in variations and disturbances in the inflow speed. When the suction flow is disturbed, air flows in at an angle of attack different from the angle at which it should originally flow, so that portions where the flow behavior on the blade surface is different partially occur, and the flow is complicated. Further, since the positions of the blades 1 and the spokes 8 are relatively changed by the rotation of the fan 2, the disturbance of the suction flow also rotates on the blade surface in the direction opposite to the rotation direction 4 of the fan 2. In other words, when viewed from a certain wing surface, the flow is disturbed as it crosses the spoke, and is affected by temporally unsteady disturbance. This is because it causes turbulent noise.

  However, when the ring 9 as shown in the first embodiment of the present invention is arranged on the suction side, the inflow velocity can be reduced constantly over the entire circumference, so that the disturbance of the inflow flow due to the spokes 8 is also affected by the inflow velocity. Decreases in proportion to the decrease. Therefore, the noise caused by the disturbance of the suction flow can be kept low. In addition, since the noise generated when the discharge flow having a high flow velocity collides with the spoke is eliminated, the total noise can be suppressed to the same level or less.

  For this reason, in the present invention, it is possible to arrange the spoke on the suction side of the fan.

  Since the suction flow 14 generated on the suction side collides with the ring 9 as shown in FIG. 1, the radial component of the suction flow is reduced, so that the speed of the suction flow 14 between the ring 9 and the annular wall 3 is reduced. descend. As a result, the leakage flow pushed back from the pressure surface to the back pressure surface easily passes between the ring 9 and the annular wall 3, and the flow pushed back to the pressure side again is prevented from generating vortices on the pressure side.

  Further, when the flow separated at the blade back pressure surface generates a vortex and grows up to the leading edge of the blade, the formation of the inter-blade vortex is hindered by the ring, so that the effect of eliminating the vortex is brought about.

  Further, since the ring according to the present invention is short in the axial direction, reducing the reverse flow speed between the ring and the housing as shown in the prior art has little effect on eliminating the influence on the inflow speed. However, since the reverse flow and the suction flow are separated by a ring that is short in the axial direction, the blade tip vortex 10 that has grown near the leading edge can be stabilized around the ring 9. In general, when vortices exist, energy stagnates in that part, which deteriorates the characteristics of the fan, but rather than the case where inter-blade flow and blade tip vortex interfere with each other to create complex turbulence, By stably generating vortices, it is possible to suppress a decrease in flow rate-static pressure characteristics and turbulent noise. In addition, the reverse flow that is insufficient to generate a vortex centered on the ring becomes a hindrance to the ring and cannot grow on the leading edge side.

  As described above, since turbulent flow generated in the vicinity of the blade can be suppressed, even when static pressure is high, turbulent noise can be reduced without deteriorating flow rate-static pressure characteristics.

The flow generated by the rotation of the fan 2 passes through a cylindrical region from the outer diameter of the boss 15 at the center of the fan to the annular wall 3. Assuming that the outer diameter of the fan is Do and the boss diameter at the center of the fan is Di, the suction flow viewed from the cross section perpendicular to the axis is the center of the blade in the radial direction (radius = (Di + Do) / 4) as shown in FIG. It flows toward. Also, the outer peripheral side is faster than the inner peripheral side of the blades, both the peripheral speed and the axial flow speed are faster, and the work rate is higher on the outer peripheral side.
The flow velocity in the region where the radius r is (Di + Do) / 4 ≦ r ≦ Do / 2 is faster. In order to suppress the radial component of the suction flow toward the central direction generated in this region, the ring diameter d is
It is more effective to install in a region that satisfies (Di + Do) / 2 ≦ d ≦ D.

  Thereby, the effect which suppresses the disturbance of the flow which arises when a suction flow collides with the spoke 8 becomes high, and the effect which suppresses the turbulent flow which arises by a blade edge flow and the flow between blades also becomes high.

  With the above configuration, turbulent vortices generated between the blade tips and between the blades are alleviated, and the noise level can be reduced and the air volume-static pressure characteristics can be improved. Further, by disposing the ring 9 on the suction side of the fan, it is possible to prevent foreign matter from being mixed, particularly on the outer peripheral side of the fan.

  In addition, when a ring is installed in a blower provided with spokes on the side opposite to the fan suction side as in the conventional example, the housing 6 and the ring 9 having a base for fixing the spokes and the motor part are integrally formed. Is impossible. However, by providing the suction side of the fan and the spoke in the same direction and fixing the ring to the spoke, the housing and the ring can be integrally formed with a mold structure as shown in FIG. Thereby, a manufacturing process becomes easy, and it becomes possible to improve productivity and reduce manufacturing cost. FIG. 8 is a perspective view showing the structure of the first embodiment. Similarly, FIG. 9 is a structural diagram (sixth view) of the first embodiment.

(Embodiment 2)
FIG. 4 is a structural diagram of the housing of the blower according to Embodiment 2 of the present invention. A housing 6 including an annular wall 3 spaced from the blade tip of the fan 2, a motor unit 7 that rotationally drives the fan 2, and a spoke 8 that couples the housing 6, and the blade tip of the fan 2 and the housing annular wall 3 A ring 9 is provided therebetween, and a current plate 16 is provided between the ring 9 and the housing annular wall 3.

  In the above configuration, since the suction flow generated on the suction side collides with the ring 9 and the current plate 16, the radial component and the swirl component of the suction flow are suppressed. That is, the speed of the suction flow 14 at the outer periphery of the fan is further reduced as compared with the case of only the ring, and the leakage flow 14 pushed back from the positive pressure side to the back pressure side of the blade tip is transferred to the ring 9, the current plate 16, and the annular wall 3. Encourage them to pass between.

  Further, as shown in FIG. 4, the vortex tip vortex 10 having a strong swirling component caused by the flow pushed back from the pressure side to the back pressure side is generated between the blade tip, that is, between the fan outer periphery and the housing annular wall, is suppressed by the rectifying plate 16. be able to.

  In addition, since static pressure is applied to the fan, the flow is pushed back from the pressure surface to the back pressure surface at the trailing edge of the blade, and the angle of attack increases due to the decrease in the flow rate. The separated flow is generated in the vicinity of the leading edge of the blade and forms a vortex, or flows into the back pressure surface of the next blade located behind in the rotational direction and causes stall. At a certain operating point, this stall causes a swivel stall that moves the cascade as the fan rotates, but not only prevents the vortex generated between the blades by providing a rectifying plate, but also the separated flow causes the next blade to move. Therefore, it is possible to prevent the stalled region from moving in the blade row and to suppress the turning stall.

  Thereby, the turbulent vortex generated in the vicinity of the blade is relaxed, the effect of suppressing the blade tip vortex is further enhanced, and the noise level can be reduced and the air volume-static pressure characteristic can be improved.

  Further, providing the current plate 16 increases the strength of the ring 9 as compared with the case where the ring 9 is fixed only to the spoke 8. FIG. 10 is a structural diagram (sixth view) of the second embodiment.

(Embodiment 3)
FIG. 5 is a structural diagram of a blower according to Embodiment 3 of the present invention. The annular wall 3 of the housing is interrupted on the discharge side, and an air pocket portion 17 opened on the discharge side is formed between the annular wall 3 and the outer periphery of the housing.

  In the blower in the conventional example, when the fan is driven to rotate in the direction of rotation, an air flow from the suction side to the discharge side is generated, and an air flow is also sucked from the blade tip portion, and particularly the low pressure There is an effect of increasing the air volume in the state. Since this portion has a wide clearance with the blade tip, the influence of air viscosity is small, and the air volume can be increased efficiently. However, if the part with the enlarged inner diameter is provided, the air volume can be increased at low pressure, but when used under a certain pressure, the leakage vortex flowing from the blade pressure side to the back pressure side grows greatly as shown in the figure. The air flow is separated from the blade surface, and a turbulent vortex is generated in the separation region, thereby increasing the turbulent noise and deteriorating the noise level and the air volume-static pressure characteristics.

  FIG. 5 is a diagram showing an air flow according to the third embodiment of the present invention. In FIG. 5, in the present embodiment, by providing an air pocket portion 17 between the annular wall 3 and the outer peripheral portion of the housing, the blade tip leakage vortex 18 that has grown greatly after the blade tip intermediate portion is generated on the fan discharge side. The noise level and the air volume-static pressure characteristics can be improved by once attenuating to some extent in the air pocket and then discharging to the discharge side.

  Moreover, the housing of this air blower can improve productivity. In general, when performing injection molding using a resin or metal material, in order to suppress the distortion of the shape due to material shrinkage, the housing shape is recessed on the outer periphery so that the thickness of each part is almost constant. Provided structure. As shown in the schematic view of the mold structure in the case of molding the housing of the first embodiment in FIG. 2, the upper and lower cores 19 and 20 and the two slide cores 21 and 22 that slide in a perpendicular direction to the upper and lower cores 19 and 20 are shown. The method of forming is common.

  FIG. 7 shows a mold structure for molding the housing of the blower according to the third embodiment. The housing according to the third embodiment is formed by only the dies 19 and 20 from the upper and lower directions without the slide cores 21 and 22. Thereby, a metal mold | die is simplified and productivity improvement and cost reduction are attained.

  By forming the housing into a shape as in the embodiment of the present invention, a portion that becomes an air suction port, a mounting hole for mounting the blower, a boss portion to which the motor portion is fixed, and a spoke portion that indicates the boss portion Air pockets that can improve fan characteristics can be molded with a mold with a much simpler structure than before, reducing mold production costs or downsizing the mold. It is possible to improve productivity and reduce costs due to the fact that it can be molded by equipment, etc. At the same time, the mold structure is simplified and the number of moving parts is reduced, so that product accuracy is stabilized and mold maintenance is performed. Can also be obtained.

  Furthermore, the housing of the present embodiment is provided with an air pocket portion, so that the overall wall thickness is kept substantially constant, so that sink marks during molding can be suppressed, accuracy can be improved, and at the same time, unnecessary material is eliminated. As a result, the weight can be reduced and the material cost can be reduced.

  In addition, by incorporating and using the blower of the above-described embodiment in a device, the air volume increases even when a static pressure is applied due to an improvement in fan efficiency, and an effect of improving the cooling capacity of the device is obtained. FIG. 11 is a structural diagram (sixth view) of the third embodiment.

  The blower device of the present invention, the method of manufacturing the blower device, and the electronic device having the blower device are effective in improving the cooling efficiency, quieting, and reducing power consumption of the electronic device, and are useful for improving the characteristics of the device. A simple motor can be provided.

Explanatory drawing of the air blower of Embodiment 1 of this invention, (a) is a front view of the air blower by Embodiment 1 of this invention, (b) is sectional drawing of the air blower by Embodiment 1 of this invention. Cylindrical cross section Structure diagram of the mold according to the first embodiment of the present invention Front view of an air blower according to Embodiment 2 of the present invention Sectional drawing of the air blower by Embodiment 3 of this invention Structural diagram of the mold according to the third embodiment of the present invention Explanatory drawing of the conventional air blower, (a) is a front view of the conventional air blower, (b) is sectional drawing of the conventional air blower. The perspective view which shows the structure of Embodiment 1. FIG. Structure diagram of Embodiment 1 (sixth view) Structure diagram of Embodiment 2 (sixth view) Structure diagram of Embodiment 3 (six views)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 wing | blade 2 fan 3 annular wall 4 rotational direction 5 air flow 6 housing 7 motor part 8 spoke 9 ring 10 blade tip vortex 11 angle of attack 12 separation flow 13 blade vortex 14 suction flow 15 boss 16 current plate 17 air pocket 18 blade tip Leakage vortex 19 Upper core 20 Lower core 21 Slide core 22 Slide core

Claims (7)

A housing having an annular wall at a position spaced from the blade tip of the fan, and a spoke that couples the rotary drive unit disposed in the center of the fan and the housing so that the spoke side becomes the suction side In the structure arrange | positioned in this, the ring is arrange | positioned at the suction side of the said fan, This ring is being fixed to the said spoke, The air blower characterized by the above-mentioned. A housing having an annular wall at a position spaced from the blade tip of the fan, and a spoke that couples the rotary drive unit disposed in the center of the fan and the housing so that the spoke side becomes the suction side A ring is disposed on the suction side of the fan disposed on the ring, the ring is fixed to the spoke, and a current plate is disposed between the ring and the annular wall. Blower to do. The diameter d of the ring disposed on the suction side of the fan has a configuration satisfying a relational expression of (Di + Do) / 2 ≦ d ≦ Do with respect to the fan outer diameter Do and the boss diameter Di. Or the air blower of Claim 2. The blower according to any one of claims 1 to 3, wherein a ring and a housing arranged on the suction side of the fan are integrally formed. The annular wall of the housing is configured to be interrupted on the discharge side, and an air pocket portion opened on the discharge side is formed between the annular wall and the outer peripheral portion of the housing. The air blower according to any one of claims 1 to 4. 6. The method of manufacturing a blower according to claim 5, wherein the housing is molded by a mold having only an upper core and a lower core. The electronic device which has a ventilation apparatus as described in any one of Claims 1-5.

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