The present invention relates to a centrifugal fan and an electronic device.
An electronic device such as a portable Laptop Personal Computer includes a centrifugal fan that radiates heat generated from electronic components in a chassis to the outside (refer to Japanese Unexamined Patent Application Publication No. 2011-227925, for example). Radiating fins are provided in an air exhaust port of this centrifugal fan.
In a centrifugal fan, since centrifugal force is applied to discharge fluid, which makes a fluid flow at an air exhaust port uneven, the fluid sometimes hits against only a part of the radiating fins.
The present invention has been made in view of the above-described problem, and aims at improving the cooling performance of the centrifugal fan.
In order to solve the above-described problem, a centrifugal fan according to one aspect of the present invention includes a fan rotating about a central axis and a fan casing enclosing the fan and having an air intake port formed in an axial direction in which the central axis extends and an air exhaust port formed in an orthogonal direction orthogonal to the central axis, radiating fins being provided in the air exhaust port, wherein a tongue portion close to the fan and an inner flow channel going around the fan from the tongue portion to the air exhaust port are formed in the fan casing, and the fan casing has a metallic plate forming at least one of a top face and a bottom face facing each other in the axial direction, and a protruding portion formed on the metallic plate and projecting toward a blow-out side of the inner flow channel opposite the tongue portion.
In addition, in the above-described centrifugal fan, the metallic plate may be a copper plate.
In addition, in the above-described centrifugal fan, the protruding portion may be formed by recessing a part of the metallic plate.
In addition, in the above-described centrifugal fan, the protruding portion may assume a triangular shape having a hypotenuse extending in a direction of crossing a main flow direction on the blow-out side of the inner flow channel when viewed from the axial direction.
In addition, in the above-described centrifugal fan, a plurality of the protruding portions may be provided with space in the main flow direction on the blow-out side of the inner flow channel when viewed from the axial direction.
In addition, in the above-described centrifugal fan, the protruding portion may be provided on the air exhaust port side from the central axis in the main flow direction on the blow-out side of the inner flow channel when viewed from the axial direction.
In addition, in the above-described centrifugal fan, the protruding portion may be formed on one of the top face and the bottom face, and a heat pipe connected to the radiating fins may be provided on the other of the top face and the bottom face.
In addition, an electronic device according to one aspect of the present invention includes the centrifugal fan described before.
The above-described aspects of the present invention can improve the cooling performance of the centrifugal fan.
The electronic device 1 includes a chassis 10 and a lid 20. This electronic device 1 is a clam shell type Laptop Personal Computer (a so-called note-type Personal Computer).
The chassis 10 is formed in a flat box shape. A keyboard 11 and a touch pad 12 are provided on an upper face 10a of the chassis 10. The keyboard 11 is disposed at a far side of the upper face 10a and the touch pad 12 is disposed at a near side of the upper face 10a. In addition, palm rest portions 13 are formed at both right and left sides of the touch pad 12 on the upper face 10a.
The lid 20 includes a display device 21 on its face facing the upper face 10a of the chassis 10. The display device 21 is formed of a liquid crystal display or an organic EL display, for example. A lower end of the lid 20 is coupled to a hinge (not shown) provided on a rear side of the chassis 10 so as to rotate around an axis extending in the right/left direction.
When the lid 20 is opened as shown in
A motherboard 30, a centrifugal fan 31, and a battery (not shown) etc. are provided in the chassis 10. Air exhaust ports 14 and a USB (Universal Serial Bus) receptacle 32 are opened in the left side face 10b of the chassis 10. A plurality of the air exhaust ports 14 are formed from the far side to the near side of the left side face 10b.
The motherboard 30 is fixed by screwing to a plurality of bosses (not shown) provided upright on the bottom of the chassis 10 and is disposed with space and in substantially parallel oppositely to the bottom. This motherboard 30 is disposed at the back side of the keyboard 11 and provided over an area approximately half the size of the chassis 10.
The centrifugal fan 31 is disposed in the far left corner of the chassis 10. The centrifugal fan 31 cools the motherboard 30 via a heat pipe 31a and exhausts air in the chassis 10 to the outside through the air exhaust ports 14. It is to be noted that air intake ports or gaps (not shown) for taking in outside air into the chassis 10 are formed in the upper face 10a or a bottom face etc. of the chassis 10.
As illustrated in
The centrifugal fan 31 includes a fan 40 rotating about a central axis O and a fan casing 50 enclosing the fan 40. An air intake port 50a and the air exhaust port 50b are formed in the fan casing 50. The air intake port 50a is opened in an axial direction in which the central axis O of the fan 40 extends, and the air exhaust port 50b is opened in an orthogonal direction orthogonal to the axial direction. The above-described plurality of radiating fins 34 are disposed in the air exhaust port 50b.
The fan casing 50 includes a cover 51 enclosing an upper part of the fan 40 and a frame 52 enclosing a lower part of the fan 40. The above-described air intake port 50a is formed in the cover 51. In addition, a plurality of air intake ports 50a are also formed in the frame 52 as illustrated in
The fan 40 includes a hub 41 rotating about a central axis O and a plurality of blades 42 provided on an outer periphery of the hub 41. The fan 40 according to the present embodiment includes a ring plate 43 to which ends of the plurality of blades 42 are annularly connected in a circumferential direction around the central axis O. These hub 41, blades 42, and ring plate 43 are integrally formed of resin material. It is to be noted that at least one of the hub 41, the blades 42, and the ring plate 43 may be formed of metallic material.
The hub 41 is formed in a topped cylindrical shape and connected to a motor (not shown) fixed to the frame 52 of the fan casing 50. The plurality of blades 42 are formed in a substantially S-shape when viewed from the axial direction in which the central axis O extends. This shape of the blades 42 makes noise relatively low even at time of high wind pressure. Such a centrifugal fan 31 is also referred to as a silent fan.
As shown in
The cover 51 and the frame 52 are connected via connecting pins 53 on a blow-out (exhaust) side of the inner flow channel 55 opposite the tongue portion 54 on which side the clearance between the fan 40 and the fan casing 50 in the inner flow channel 55 becomes larger. It is to be noted that the blow-out side of the inner flow channel 55 refers, when a first straight line L1 connecting the central axis O and the air exhaust port 50b in the shortest distance among orthogonal directions orthogonal to the central axis O is regarded as a border line, to a side of the inner flow channel 55 opposite the side where the tongue portion 54 is disposed across the first straight line L1 (that is, it refers to a side of the page lower than the first straight line L1 in
Protruding portions 60 are protrusively provided on the blow-out side of the inner flow channel 55. The protruding portions 60 are provided on the cover 51, of the cover 51 forming a top face 50d (refer to
As shown in
In addition, the protruding portion 60 assumes a triangular shape having a hypotenuse 61 extending in a direction of crossing the main flow direction F when viewed from the axial direction. The hypotenuse 61 makes an acute angle (for example, about 30° to 60°) with the main flow direction F. The radiating fins 34 are disposed on an extension of the hypotenuse 61. The slope of the hypotenuse 61 may be such that the extension of the hypotenuse 61 heads toward the radiating fins 34 disposed in the center of the air exhaust port 50b.
In addition, the protruding portions 60 are provided on the air exhaust port 50b side from the central axis O in the main flow direction F when viewed from the axial direction. That is, the protruding portions 60 are provided on a side of the inner flow channel 55 where the air exhaust port 50b is disposed, when a second straight line L2 orthogonal to the above-described first straight line L1 among orthogonal directions orthogonal to the central axis O is regarded as a border line (that is, they are provided on the left side of the page from the second straight line L2 in
Such protruding portions 60 are formed by recessing a part of the cover 51 (copper plate) as shown in
As shown in
In addition, since the cover 51 on which the protruding portions 60 are formed, is a copper plate in the present embodiment, it has excellent thermal conductivity and good workability. Thus, the protruding portion 60 can be easily formed by recessing a part of the cover 51 by press working etc. It is to be noted that no fluid leaks out from the inner flow channel 55 since forming the protruding portion 60 by recessing does not form any gap or hole in the cover 51 in working compared to the protruding portion 60 of the modified example (cutting and bending) shown in
In addition, in the present embodiment, since the protruding portion 60 assumes a triangular shape having the hypotenuse 61 extending in a direction of crossing the main flow direction F on the blow-out side of the inner flow channel 55 when viewed from the axial direction as shown in
Two (performance “Excellent”) or three (performance “Good”) protruding portions 60 are more preferable in performance than one protruding portion 60 (performance “Fair”) as shown in
In addition, two protruding portions 60 (performance “Excellent”) are more preferable in performance than three protruding portions 60 (performance “Good”). This is thought to be because the protruding portion 60 at the position indicated by the symbol (C) in
Although the embodiments of this invention have been described in detail with reference to the drawings, specific structures are not limited to the above-described embodiments and design etc. without departing from the scope of this invention is also included. Each structure described in the above-described embodiments can be optionally combined unless they are inconsistent with each other.
Although the embodiment of forming the protruding portions 60 on the cover 51 forming the top face 50d is illustrated by an example in the above-described embodiments, for example, the protruding portions 60 may be formed on the frame 52 forming the bottom face 50e. In addition, the protruding portions 60 may be formed on both the cover 51 and the frame 52.
Furthermore, when the fan casing 50 intakes the fluid from its top and bottom parts as the present embodiment, the protruding portions 60 may be provided on a part whose fluid intake amount is smaller (that is, the part opposed to a part whose fluid intake amount is larger (the cover 51 or the frame 52)).
Moreover, although the above-described embodiments have been described using a Laptop Personal Computer as one example of an electronic device, for example, the present invention is not limited thereto but may be applied to other electronic devices such as a tablet.
Number | Date | Country | Kind |
---|---|---|---|
2019090984 | May 2019 | JP | national |