Patent Application
20120156022
1. Field of the Invention
The present invention relates to a blower fan and a method of manufacturing the blower fan.
2. Description of the Related Art
FIG. 2A of JP-A 2006-207578 discloses a horizontal blower 100. Paragraph [0010] of JP-A 2006-207578 states that the horizontal blower 100 is made up of a housing 102 and an impeller 108. Paragraph [0012] of JP-A 2006-207578 states that the housing 102 is made up of outer frames 102a and 102b joined to each other, and that the outer frames 102a and 102b can be joined to each other through, for example, coupling, riveting, locking, adhesion, or the like.
FIG. 4 of US 2009/0230798 discloses a fan motor 1, a plate member 2, a coupling barrel 3, and an outer case 4. Paragraph [0019] of US 2009/0230798 states that the plate member 2 is made of metal, and that the coupling barrel 3 and the outer case 4 are made of plastic. According to paragraphs [0020] and [0021] of US 2009/0230798, the coupling barrel 3, to which the fan motor 1 is attached, is coupled to a through-hole 23 of the plate member 2 through insert molding. In addition, the plate member 2 includes a plurality of positioning legs 24 arranged to extend obliquely from a periphery of the through-hole 23. The positioning legs 24 are embedded in the coupling barrel 3. According to paragraph [0022] of US 2009/0230798, the outer case 4 includes a case body 41 and a cover body 42. The cover body 42 is arranged to extend from the case body 41 to cover a side of the plate member 2 opposite to a side thereof which faces the fan motor 1.
Achieving a reduced thickness of a blower fan as described in US 2009/0230798 is not easy to perform because the cover body 42 of the outer case 4 is arranged below the plate member 2 in an overlapping manner. This being the case, regarding the blower fan of US 2009/0230798, it is only conceivable to join an edge portion of a lower plate portion, to which a motor portion is fixed, to a lower end portion of a side wall portion of a housing through insert molding. In this case, it is necessary to ensure sufficient joint strength between the lower plate portion and the side wall portion to prevent removal of the lower plate portion from the side wall portion.
Here, the blower fan is used, for example, to cool an interior of a case of a notebook personal computer (hereinafter referred to as a “notebook PC”). Regarding the notebook PC, there is a desire to avoid arranging the blower fan such that the blower fan visually stands out when the interior of the case, which is colored black, for example, is viewed through an air inlet defined in the case. It is therefore necessary that a lower surface of the lower plate portion of the blower fan should be colored black. In the case where the lower plate portion is colored black through electrodeposition coating, an outer circumferential surface of the lower plate portion is also coated with a smooth coat of paint, and therefore, only a limited increase in the joint strength between the lower plate portion and the side wall portion can be achieved because of the need to apply paint through, for example, an electrodeposition coating.
A preferred embodiment of the present invention provides a blower fan which includes an impeller centered on a central axis extending in a vertical direction, a motor portion arranged to rotate the impeller about the central axis, and a housing arranged to accommodate the impeller. The housing preferably includes an upper plate portion arranged to cover an upper side of the impeller; a lower plate portion arranged to cover a lower side of the impeller, and having the motor portion fixed thereto; and a side wall portion arranged to cover a side of the impeller, and to define an air outlet in combination with the upper plate portion and the lower plate portion. At least one of the upper plate portion and the lower plate portion preferably includes an air inlet defined therein. The lower plate portion is preferably defined by, for example, a steel sheet which includes a lower surface that is coated with paint beforehand and which is then subjected to, for example, a press forming process and a stamping process. The lower plate portion will then include an outer circumferential cut surface as a result of the stamping process. The side wall portion is preferably made of, for example, a resin. A lower end portion of the side wall portion and an edge portion of the lower plate portion are joined to each other through, for example, insert molding, with the outer circumferential cut surface of the lower plate portion arranged in contact with the side wall portion at a joint located between the lower end portion of the side wall portion and the edge portion of the lower plate portion.
A blower fan according to preferred embodiments of the present invention is able to achieve an increase in joint strength between the lower plate portion and the side wall portion of the housing.
The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is assumed herein that an upper side and a lower side in a direction parallel or substantially parallel to a central axis of a blower fan illustrated in
The blower fan 1 includes a motor portion 2, a housing 3, and an impeller 4. The impeller 4 is centered on a central axis J1 extending in the vertical direction. The motor portion 2 is arranged to rotate the impeller 4 about the central axis J1. The housing 3 is arranged to accommodate the motor portion 2 and the impeller 4.
The housing 3 preferably includes an upper plate portion 31, a lower plate portion 32, and a side wall portion 33. The upper plate portion 31 is arranged to cover an upper side of the impeller 4 in
Both the upper plate portion 31 and the lower plate portion 32 are preferably made of, for example, a metal. The side wall portion 33 is preferably made of, for example, a resin. A lower end portion 332 of the side wall portion 33 and an edge portion 328 of the lower plate portion 32 are preferably joined to each other through, for example, insert molding. The edge portion 328 of the lower plate portion 32 refers to a portion in the vicinity of an outer circumference of the lower plate portion 32. The upper plate portion 31 is fixed to an upper end portion of the side wall portion 33 through, for example, screwing or the like. A lower surface 325 of the lower plate portion 32 is colored black through, for example, a coat of paint, so that the blower fan 1 is prevented from visually standing out when an interior of the case of the notebook PC, which is colored black, is viewed through an air inlet defined in the case. An upper surface 326 of the lower plate portion 32 is preferably not provided with a coat of paint. Note that the color of the coat is not limited to black in other preferred embodiments of the present invention and can instead be any other desirable color.
Referring to
The three ribs 323 are arranged between the three lower air inlets 321, which are arranged in the circumferential direction to substantially surround an outer circumference of the motor fixing portion 322. In other words, each of the three lower air inlets 321 is defined between the motor fixing portion 322, the outer portion 324, and a pair of adjacent ones of the ribs 323.
As illustrated in
The stationary portion 21 preferably includes a stator 210 and a bearing support portion 24. The bearing support portion 24 is arranged to accommodate the sleeve 23. The bearing support portion 24 is substantially in the shape of a cylinder and centered on the central axis J1, and is preferably made of, for example, a resin. The bearing support portion 24 is arranged to project upward from the motor fixing portion 322 of the lower plate portion 32. The bearing support portion 24 is fixed to a hole portion 327 defined in the motor fixing portion 322. A lower end portion of the bearing support portion 24 and a portion surrounding the hole portion 327 of the motor fixing portion 322 are joined to each other preferably through insert molding, for example.
The stator 210 is provided with an annular shape and arranged to be centered on the central axis J1, and is attached to an outside surface of the bearing support portion 24. The stator 210 preferably includes a stator core 211, an insulator 212, and coils 213. The stator core 211 is preferably defined by laminated silicon steel sheets each of which is in the shape of a thin plate, although any other desirable type of stator core could be used instead. The insulator 212 is arranged to cover a surface of the stator core 211.
The rotating portion 22 includes a shaft 221, a yoke 222, a rotor magnet 223, and a cup 224. The cup 224 preferably is substantially in the shape of a covered cylinder and centered on the central axis J1, and includes a downward opening. The shaft 221 is arranged to have the central axis J1 at its center, and an upper end portion of the shaft 221 is fixed to the cup 224. The yoke 222 is substantially in the shape of a cylinder and centered on the central axis J1, and is fixed to an inside surface of the cup 224. The rotor magnet 223 preferably is substantially in the shape of a cylinder and centered on the central axis J1, and is fixed to an inside surface of the yoke 222.
The shaft 221 is inserted inside the sleeve 23. The sleeve 23 is preferably made of an oil-bearing porous metal, for example. The sleeve 23 is inserted in and fixed to the bearing support portion 24. Note that a ball bearing, for example, may be used as a bearing mechanism in other preferred embodiments of the present invention.
The impeller 4 includes a plurality of blades 41. The blades 41 are preferably arranged to have an annular shaped arrangement around the outside of the cup 224, and centered on the central axis J1. A radially inner end portion of each blade 41 is fixed to an outside surface of the cup 224. A current is supplied to the stationary portion 21 to produce a torque centered on the central axis J1 between the rotor magnet 223 and the stator 210. The impeller 4 is thereby arranged to rotate about the central axis J1 together with the rotating portion 22 in response to the torque produced between the rotor magnet 223 and the stator 210. The rotation of the impeller 4 causes air to be introduced into the housing 3 through the upper air inlet 311 and the lower air inlets 321, and sent out through the air outlet 331.
Next, a method of manufacturing the blower fan 1 will now be described below.
In the production of the blower fan 1, at first, a flat pre-coated steel sheet whose lower surface is coated with a black paint beforehand is prepared (step S11). An upper surface of the precoated steel sheet is preferably not provided with a coat of paint. Note that the upper surface of the precoated steel sheet may be provided with a coat of paint in other preferred embodiments of the present invention. Next, the precoated steel sheet is subjected to, for example, a press forming process and a stamping process to define the lower plate portion 32 of the housing 3 as illustrated in
When the stamping process is performed at step S12, an outer circumferential cut surface 328a is formed at a side surface of the lower plate portion 32. In addition, the lower air inlets 321 and an inner circumferential cut surface 321a of each of the lower air inlets 321, and the hole portion 327 and a cut surface 327a of the hole portion 327 are also formed at this time. The portion surrounding the hole portion 327 is deformed to project upward as a result of the press forming process, with the result that the cut surface 327a faces upward.
Referring to
Assume, for example, a steel sheet is subjected to press forming process and a stamping process, and that the resulting steel sheet is subjected to electrodeposition coating or the like to define the lower plate portion. In this case, an outer circumferential surface of the lower plate portion will be a smooth surface with a coat of paint. In contrast, the outer circumferential cut surface 328a of the lower plate portion 32 of the blower fan 1 is an uncoated cut surface resulting from the stamping process, as described above. The outer circumferential cut surface 328a is therefore rougher than the outer circumferential surface with the coat of paint. This contributes to an increase in the joint strength between the lower plate portion 32 and the side wall portion 33, which in turn contributes to an improvement in strength of the housing 3.
As a result of the stamping process performed at step S12, an upward facing burr 328b is defined at the outer circumferential cut surface 328a of the lower plate portion 32. The burr 328b is arranged inside the lower end portion 332 of the side wall portion 33 and in contact with the side wall portion 33. This burr 328b and its arrangement inside the lower end portion 332 of the side wall portion 33 contributes to an additional increase in the joint strength between the lower plate portion 32 and the side wall portion 33.
At the joint between the side wall portion 33 and the lower plate portion 32, the lower end portion 332 of the side wall portion 33 is also arranged in contact with an upper surface of the edge portion 328 of the lower plate portion 32. This makes it easier to determine the position of the lower plate portion 32 relative to the side wall portion 33 during the insert molding at step S13. The insert molding is thus easily accomplished.
Referring to
After step S14 is completed, the stator 210 illustrated in
The upper plate portion 31 is thereafter fixed to the upper end portion of the side wall portion 33 to define the housing 3 having the air outlet 331 on its side (step S16). A lower boundary of the air outlet 331 is defined by a portion of the outer circumferential cut surface 328a of the lower plate portion 32. In other words, a portion of the outer circumferential cut surface 328a of the lower plate portion 32 is exposed below the air outlet 331. This portion of the outer circumferential cut surface 328a will be hereinafter referred to as an “exposed portion”. In the present preferred embodiment, the exposed portion of the outer circumferential cut surface 328a is preferably not provided with a coat of paint. Note that the exposed portion of the outer circumferential cut surface 328a may be colored black through, for example, an oil-based ink or the like in other preferred embodiments of the present invention.
While preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described preferred embodiments, but a variety of modifications are possible.
For instance, the blower fan 1 may be installed inside a case of a notebook PC with the upper plate portion 31 of the blower fan 1 being visible from outside the notebook PC. In this case, the upper plate portion 31 needs to be colored and thus the upper plate portion 31 may also be defined by, for example, subjecting a precoated steel sheet whose principal surface corresponding to the upper surface of the upper plate portion 31 is coated with a paint beforehand to, for example, a press forming process and a stamping process. Alternatively, a steel sheet without a coat of paint may be subjected first to electrodeposition coating or the like and thereafter to press forming process and a stamping process to define the upper plate portion 31 with the upper surface thereof coated with paint. Only the upper plate portion 31 may be made from a precoated steel sheet to have the upper surface coated with paint, depending on the arrangement of the blower fan 1 inside the case of the notebook PC and on the structure of the housing 3.
Although the upper air inlet 311 and the lower air inlets 321 are preferably provided in the housing 3 of the blower fan 1 according to the above-described preferred embodiments, only either the upper air inlet 311 or the lower air inlet(s) 321 may be provided in other preferred embodiments of the present invention, depending on the purpose of the blower fan. In other words, it is enough that at least one of the upper plate portion 31 and the lower plate portion 32 of the housing 3 includes an air inlet defined therein.
Note that features of the above-described preferred embodiments and modifications thereof may be combined appropriately as long as no conflict occurs.
Blower fans according to preferred embodiments of the present invention can be used to cool a device inside a case of a notebook PC or a desktop PC, to cool other devices, to supply air to a variety of objects, and so on. Blower fans according to preferred embodiments of the present invention are also usable for other purposes.
While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-278291 | Dec 2010 | JP | national |
| Number | Date | Country | |
|---|---|---|---|
| 61360023 | Jun 2010 | US |
