Patent Application
20190316601
The present disclosure relates to a fan unit.
A heat dissipation device (fan main body) may be attached to an electric device to dissipate heat generated internally to the outside. As a fixing structure of such a heat dissipation device, one employing screw fixing is known (JP 2000-209717 A).
It is conceivable to reduce costs by adopting a snap fit as a fixing structure of a heat dissipation device. However, in general, a fixing structure using a snap fit has a problem that it is easily loosened and rattled.
Example embodiments of the present disclosure provide fan assemblies that each include a fixing structure that reduces costs and suppresses loosening and rattling.
One example embodiment of a fan assembly of the present disclosure includes a fan main body including a blade that rotates and a frame that rotatably supports the blade, and a casing including a main body provided with a housing recess in which the fan main body is to be housed, and a snap-fit portion to fix the frame in the housing recess. The housing recess includes a housing bottom including a surface facing upward and a housing inner circumferential portion extending upward from the housing bottom, and opens upward. The snap-fit portion includes an elastic portion extending upward along the housing inner circumferential portion, and a claw portion projecting horizontally from a tip end portion of the elastic portion. A lower surface of the claw portion is inclined upward toward the tip of the claw portion. The frame is interposed between and in contact with the lower surface of the claw portion and the housing bottom.
According to one example embodiment of the present disclosure, it is possible to provide a fan assembly including a fixing structure that reduces costs and suppresses loosening and rattling.
The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.
Hereinafter, a fan assembly 1 according to an example embodiment of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, an xyz coordinate system is shown appropriately as a three-dimensional orthogonal coordinate system. In the xyz coordinate system, a z-axis direction is assumed to be a direction parallel to a central axis J of a fan main body 5. A y-axis direction is assumed to be a direction orthogonal to the z-axis direction, extending from the upper right to the lower left in
In the following description, the positive side (+z side, one side) in the z-axis direction is referred to as an “upper side”, and the negative side (−z side, the other side) in the z-axis direction is referred to as a “lower side”. It should be noted that the definitions of the upper side and the lower side are made simply for the sake of description, and are not meant to restrict actual relative positions or directions. Also, unless otherwise explained, a direction (z-axis direction) parallel to the central axis J is simply referred to as an “axial direction” or a “vertical direction”, a radial direction having its center on the central axis J is simply referred to as a “radial direction”, and a circumferential direction having its center on the central axis J, that is, a direction about the central axis J, is simply referred to as a “circumferential direction”.
The fan main body 5 has an impeller (blade portion) 50 that rotates around a central axis J extending in the vertical direction, a motor (not shown) that causes the impeller 50 to rotate, and a frame 55 that supports the impeller 50 and the motor.
The impeller 50 has a cylindrical impeller cup 50a connected to the rotation shaft of the motor along the central axis J, and a plurality of wings 50b arranged along the circumferential direction from the outer peripheral surface of the impeller cup 50a. The impeller 50 rotates in a counterclockwise direction as viewed from above, for example. The motor is disposed inside the impeller 50.
The frame 55 is in a form of a rectangular tube extending in the vertical direction. The outer shape of the frame 55 is substantially square when viewed from the vertical direction. The frame 55 circumferentially surrounds the impeller 50 and the motor from the radially outer side. The frame 55 rotatably supports the impeller 50. The frame 55 also supports the motor from below. The frame 55 has corner portions 55a arranged at the four corners. The corner portion 55a is substantially triangular when viewed from the vertical direction. The corner portion 55a has a through hole 55b. A screw for fixing the frame 55 to the casing 2 can be inserted into the through hole 55b. Such a screw is used as a backup for a snap fit fixing structure described later. That is, the frame 55 can be fixed to the casing 2 with a screw inserted into the through hole 55b and fastened to the casing 2, even if the fixing structure by the snap fit is damaged for any reason.
The frame 55 has an upper surface 55c facing upward and a lower surface 55d facing downward. The upper surface 55c and the lower surface 55d are provided with openings at least in a portion overlapping with the impeller 50 when viewed from the vertical direction, so that the air flow accompanying the rotation of the impeller 50 is not hindered.
As viewed from the upper side, the edge of the frame 55 is provided with four upper holding portions (first holding portions) 56. The upper holding portion 56 is in the form of a plate substantially parallel to the upper surface 55c. The upper holding portion 56 is located below the upper surface 55c. The upper holding portion 56 is recessed downward with respect to the upper surface 55c. As shown in
As viewed from below, the edge of the frame 55 is provided with four lower holding portions (second holding portions) 59 having the same configuration as that of the upper holding portion 56. The lower holding portion 59 is located above the lower surface 55d and below the upper holding portion 56. The lower holding portion 59 is recessed upward with respect to the lower surface 55d. The lower holding portion 59 has a shape in which the upper holding portion 56 is vertically inverted. The lower holding portion 59 overlaps with the upper holding portion as viewed from the vertical direction. The lower holding portion 59 includes a second holding upper surface (upper surface) 59a facing upward when the fan main body 5 is inverted, and a second holding lower surface (inversion lower surface) 59b located opposite to the second holding upper surface 59a. In
According to the present example embodiment, the fan main body 5 has the upper holding portion 56 and the lower holding portion 59 which are disposed at different positions in the vertical direction and overlap with each other when viewed from the vertical direction. In the upper holding portion 56 and the lower holding portion 59, claw portions are hooked to either the upper holding portion 56 or the lower holding portion 59 when the fan main body 5 is inverted. As a result, the fan main body 5 can be housed in the housing recess 30 in an inverted manner, and the air blowing direction to the casing 2 can be easily changed.
As shown in
The main body 3 has a rectangular shape in a plan view in which one direction (in the present example embodiment, the y-axis direction) has long sides 3a and 3b when viewed from the vertical direction. The main body 3 has a symmetrical shape with respect to a center line L passing through the center of the pair of long sides 3a and 3b when viewed from the vertical direction. The main body 3 has an upper surface 3c facing upward.
The housing recess 30 is recessed downward from the upper surface 3c of the main body 3 and opens to the upper side. The two housing recesses 30 are provided side by side in the direction in which the long sides 3a and 3b of the main body 3 extend. The housing recess 30 has a substantially square shape as viewed from above. The housing recess 30 has a housing bottom 31 having a bottom surface (a surface facing upward) 31a, and a housing inner circumferential portion 32 extending upward from the housing bottom 31.
The housing bottom 31 is substantially square when viewed from above. The housing bottom 31 has an opening 31h penetrating in the vertical direction. The opening 31h of the housing bottom 31 overlaps with at least the impeller 50 of the fan main body 5 when viewed from the vertical direction, and does not inhibit the air flow accompanying the rotation of the impeller 50.
The bottom surface 31a of the housing bottom 31 is provided with positioning pins 33 for positioning the fan main body 5 in the housing bottom 31. The positioning pin 33 extends upward from the housing bottom 31. The positioning pin 33 is to be inserted into a positioning hole 57 provided in the frame 55.
The housing inner circumferential portion 32 surrounds the housing recess 30 from the radially outer side (horizontal direction). The housing inner circumferential portion 32 extends upward in an angular tube shape from the outer edge of the bottom surface 31a. As shown in
As shown in
The elastic portion 41 extends upward from the recessed bottom surface 32b of the recess 32a. As shown in
The claw portion 42 is located at an upper end portion of the elastic portion 41. The claw portion 42 has a tip 42t located inside the housing recess 30. The claw portion 42 protrudes from the front surface 41a of the elastic portion 41 toward the tip 42t. The claw portion 42 also has a claw upper surface (upper surface) 42b facing upward and a claw lower surface (lower surface) 42a located on the opposite side thereof and facing downward.
In the process of housing the fan main body 5 in the housing recess 30, when the fan main body 5 is moved downward toward the housing recess 30, the first holding lower surface 56b of the fan main body 5 slides on the claw upper surface 42b, and the elastic portion 41 bends and the claw portion 42 moves to the outside of the housing recess 30. Furthermore, at the stage when the first holding upper surface 56a reaches below the claw lower surface 42a, the claw portion 42 moves to the inside of the housing recess 30, and the claw portion 42 is caught by the upper holding portion 56.
The claw lower surface 42a faces the bottom surface 31a of the housing bottom 31 in a state where the fan main body 5 is not housed in the housing recess 30. The claw lower surface 42a inclines upward toward the tip 42t of the claw portion 42. As shown in
In the conventional snap-fit structure, when the dimensions of the object to be fixed by the snap-fit structure vary and become smaller, a gap is generated between the parts engaged with each other. Therefore, the object fixed by the snap fit structure may rattle by the amount of the gap generated.
On the other hand, in the present example embodiment, the distance from the base end in the projecting direction of the claw lower surface 42a to the bottom surface 31a is smaller than the distance along the vertical direction between the first holding upper surface 56a and the lower surface 55d of the frame 55. Meanwhile, the distance along the vertical direction from the tip in the projecting direction of the claw the lower surface 42a to the bottom surface 31a is larger than the distance along the vertical direction between the first holding upper surface 56a and the lower surface 55d of the frame 55. In the claw portion 42, the claw lower surface 42a is inclined as described above. Since the claw lower surface 42a of the claw portion is pressed to the inside of the housing recess 30 by the elasticity of the elastic portion 41, even if the dimensions along the vertical direction of the first holding upper surface 56a and the lower surface 55d of the frame 55 vary, the claw lower surface 42a contacts the first holding upper surface 56a at somewhere in the projecting direction. Thus, the frame 55 can be vertically interposed between the claw lower surface 42a and the bottom surface 31a, and a stress due to the elasticity of the elastic portion 41 can be applied. The frame 55 is interposed in a state of being in contact with the claw lower surface 42a and the housing bottom 31, and rattling of the frame 55 is suppressed.
As shown in
According to the present example embodiment, it is possible to suppress loosening and rattling of the fan main body housed in the housing recess 30, without using a fastening structure such as a screw. As a result, the number of components can be reduced, the assembly process can be simplified, and cost reduction can be realized.
In the snap-fit portion 4, the pair of claw portions 42 may not necessarily be disposed to face each other. As an example, the snap-fit portion 4 may be disposed only on one long side 3a of the pair of long sides 3a and 3b. In that case, the snap-fit portion 4 generates a stress that presses the fan main body 5 against the housing inner circumferential portion 32 on the other long side 3b of the housing recess 30, thereby suppressing rattling of the fan main body 5.
The inclination angle θa (see
The claw upper surface 42b is inclined downward toward the tip 42t of the claw portion 42.
The claw upper surface 42b is curved in a circular arc, and the inclination with respect to the projecting direction (−x direction in
The inclination angle of the claw upper surface 42b with respect to the projecting direction of the claw portion 42 is referred to as an upper surface inclination angle. When the upper surface inclination angle approaches 90°, the ratio of the component force in the lateral direction, of the force exerted from the first holding lower surface 56b to the claw upper surface 42b, increases in the housing process of the fan main body 5. Accordingly, the elastic portion 41 can be elastically deformed with a small force. Therefore, although the fan main body 5 can be housed in the housing recess 30 with a small force, the dimension along the vertical direction of the claw portion 42 is increased.
In the present example embodiment, the claw upper surface 42b is curved and the inclination of the claw upper surface 42b with respect to the projecting direction of the claw portion 42 is increased and gradually approached to 90° toward the tip 42t. As a result, the housing operation of the fan main body 5 can be facilitated, and the dimension of the claw portion 42 in the vertical direction can be sufficiently reduced. In addition, according to the present example embodiment, since the claw upper surface 42b has the above-described configuration, even when the posture of the claw portion 42 is inclined to the outside of the housing recess 30 due to the elastic deformation of the elastic portion 41, the inclination angle of the claw upper surface 42b is secured to enable smooth housing operation.
The grip portion 43 protrudes upward from the claw portion 42. By gripping the grip portion 43, the operator can elastically deform the elastic portion 41 so as to move the claw portion 42 toward the outside of the housing recess 30. As a result, the operator can release the engagement of the claw portion 42 with the upper holding portion 56 and take out the fan main body 5 from the housing recess 30.
As shown in
The positioning pin 33 has a pin main body 34 extending in the vertical direction along an axis O1 parallel to the vertical direction, and a plurality of ribs 35 provided to the outer peripheral surface of the pin main body 34.
The pin main body 34 has a cylindrical portion 34b and a tapered portion 34a. That is, the positioning pin 33 has the cylindrical portion 34b and the tapered portion 34a. The cylindrical portion 34b extends along the axis O1 about the axis O1. The diameter of the cylindrical portion 34b is uniform. The tapered portion 34a is located above the cylindrical portion 34b. In the tapered portion 34a, the diameter of the positioning pin 33 decreases, from base end 33b side of the positioning pin 33 toward the tip 34t. Since the tapered portion 34a is provided, it facilitates insertion of the positioning pin 33 into the positioning hole 57. That is, the operator can insert the positioning pin 33 into the positioning hole 57 along the tapered portion 34a only by moving the fan main body 5 downward toward the housing bottom 31. Thereby, positioning can be realized easily.
As shown in
The plurality of ribs 35 project radially outward in the radial direction of the axis O1 from the cylindrical portion 34b of the pin main body 34. Also, the ribs 35 extend along the axis O1. In the present example embodiment, the rib 35 has a prismatic shape elongated in the vertical direction. The rib 35 extends upward along the outer peripheral surface of the cylindrical portion 34b from the bottom surface of the recess 33h. The plurality of ribs 35 are equally spaced along the axis O1. In the present example embodiment, four ribs 35 are provided at intervals of 90° around the axis O1 with respect to one pin main body 34.
When the positioning pin 33 is inserted into the positioning hole 57, the plurality of ribs 35 contact the inner circumferential surface of the positioning hole 57. Therefore, the positioning pin 33 can be press-fit into the positioning hole by elastically deforming the ribs 35 inward in the radial direction. Thus, the position of the positioning pin 33 can be suppressed from being shifted with respect to the positioning hole 57. Therefore, the fan main body 5 can be fixed in the housing recess 30 with high positional accuracy without being displaced. Further, as shown in
When the positioning pin 33 is pressed into the positioning hole 57, part of the rib 35 that elastically deforms may be scraped off. According to the present example embodiment, since the recess 33h is provided, part of the scraped rib 35 falls into the recess 33h. Therefore, the scraped rib 35 is not pinched between the lower surface 55d of the frame 55 of the fan main body 5 and the bottom surface 31a of the housing recess 30, so that the fan main body 5 can be suppressed from rising from the bottom surface 31a.
The present disclosure is not limited to the above-described example embodiment, and other configurations can be adopted. For example, the number of fan main bodies 5 attached to the casing 2 is not limited to that described in the example embodiment. Moreover, the number of snap-fit portions 4 with respect to one housing recess 30 is not limited to that described in the example embodiment. Further, in the case of having a plurality of snap-fit portions, the claw lower surface 42a of at least one snap-fit portion 4 may be inclined. Further, the shape of the claw upper surface 42b is not limited to that described in the example embodiment. Moreover, although the case where the claw portion 42 hooks on the upper holding portion 56 has been illustrated in the example embodiment, it is also possible to employ a structure that it hooks on the upper surface 55c of the frame 55. Further, the above-described example embodiment employs the configuration in which the lower holding portion 59 is provided to the frame 55 so that the fan main body 5 can be attached to the casing 2 even when the fan main body 5 is inverted. However, it is possible to adopt a structure in which the lower holding portion 59 is not provided, and the fan main body 5 may not be attached to the casing 2 when it is inverted. In that case, it can suppress the case where the fan main body 5 is assembled while being inverted.
The respective configurations can be appropriately combined within a range not inconsistent with each other.
While example embodiments of the present disclosure 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 disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-024095 | Feb 2017 | JP | national |
This is the U.S. national stage of PCT Application No. PCT/JP2018/004224, filed on Feb. 7, 2018, and priority under 35 U.S.C. § 119(a) and 35 U.S.C. § 365(b) is claimed from Japanese Application No. 2017-024095, filed Feb. 13, 2017; the entire disclosures of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/004224 | 2/7/2018 | WO | 00 |
