JP5100711B2 - Turbo fan - Google Patents

Description

  The present invention relates to a turbofan that is applied to a hand dryer, a vacuum cleaner, or the like, and more particularly, to an improvement in mechanical strength thereof.

  The turbo fan is fixed to a rotation shaft such as a motor as a rotation drive source, and blows air by rotating with the rotation of the rotation shaft. The turbofan is arranged with a boss part fixed to the rotating shaft of the motor, a disk-shaped main plate part joined to the boss part, and opposed to the main plate part, and an opening serving as an air suction port at the center of rotation. It is comprised from the disk-shaped side-plate part provided with the hole, and the some wing | blade part arrange | positioned radially at equal intervals with respect to the rotating shaft between the main-plate part and the side-plate part.

  Such a turbofan requires high-speed rotation in order to obtain the desired air blowing performance, but there are problems in weight reduction and improvement in strength (durability). Therefore, conventionally, a circular or semicircular curled portion is provided around the outer peripheral edge of the main plate portion, or a bead portion (swelling) is provided around the boss portion (see, for example, Patent Document 1). ).

JP 61-25999 A

  The turbofan described in Patent Document 1 described above is such that the outer peripheral edge of the main plate portion is reinforced by a curled portion, and the periphery of the boss portion is reinforced by a bead portion. These curled portions and bead portions are locally It increases the strength. If the strength is increased locally in this way, problems such as an increase in stress at other parts may occur even if the stress at that part decreases, so additional measures are required to reinforce the part. is there. As a result, the effects of weight reduction and reduction in production cost and improvement in air blowing performance due to weight reduction are hindered.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a turbofan capable of reducing the weight and improving the overall strength and durability.

  In order to solve the above-described problems and achieve the object, the present invention provides a boss portion fixed to a rotating shaft, a main plate portion joined to the boss portion, and an opening hole serving as an air suction port in the center of rotation. A side plate portion disposed opposite to the main plate portion, and a blade composed of a plurality of wing portions arranged radially at equal intervals with respect to the rotation axis between the main plate portion and the side plate portion. The axis parallel to the rotation axis from the plane perpendicular to the rotation axis to the center of gravity of the blade is passed through a joint point at the joint portion between the boss portion and the main plate portion. In a mode in which the directional distance is reduced, the thickness of the main plate portion is gradually increased from the center of rotation toward the outer peripheral edge.

  According to the present invention, since the stress generated in the main plate portion, the side plate portion and the wing portion forming the blades is reduced, the weight can be reduced without excessively increasing the thickness, and the strength and durability of the entire turbofan can be improved. Can be improved.

FIG. 1 is a perspective view of the turbo fan according to the first embodiment of the present invention as viewed from the side plate portion side. FIG. 2 is a perspective view of the turbo fan according to the first embodiment of the present invention viewed from the main plate portion side. FIG. 3 is a partial cross-sectional perspective view of the turbofan. FIG. 4 is a conceptual diagram of a turbo fan. FIG. 5 is a schematic cross-sectional view of a turbo fan. FIG. 6 is a conceptual diagram of a turbofan in which the center side of the main plate portion is curved. FIG. 7 is a conceptual diagram of the turbo fan according to the second embodiment of the present invention. FIG. 8 is a partial cross-sectional view of the turbo fan according to the third embodiment of the present invention. FIG. 9 is a partial cross-sectional view of the turbo fan according to the third embodiment of the present invention.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
As shown in FIGS. 1 to 3, the turbo fan 100 includes a boss portion 1, a main plate portion 2, a side plate portion 3, and a wing portion 4, and is rotationally driven by a rotational drive source such as a motor (not shown). Is. The turbofan 100 is formed by integrally forming or welding or welding the metal material or resin material having the above-described configuration, or by combining the metal material and resin material having the above-described configuration with welding or welding. It is formed or formed by welding, welding or the like by combining different kinds of metal materials or different kinds of resin materials having the above-mentioned configuration.

  The boss portion 1 is formed in a cylindrical shape, and a rotation shaft C of a rotation drive source (not shown) is inserted and joined therein. That is, the boss portion 1 rotates around the rotation axis C as the rotation axis C rotates.

  The main plate portion 2 is joined to the outer periphery of the boss portion 1. The main plate portion 2 is formed in a substantially disk shape having a rotationally symmetric shape with respect to the rotation axis C, and the boss portion 1 is arranged at the center in a manner that the center of the main plate portion 2 coincides with the rotation axis C. Yes.

  The side plate portion 3 has a rotationally symmetric shape with respect to the rotation axis C, is formed in a disk shape having substantially the same outer diameter as the main plate portion 2, and the main plate portion 2 has a center that coincides with the rotation axis C. Are arranged opposite to each other. Further, the side plate portion 3 is formed with an opening hole 3a penetrating in the center thereof, and presents a hollow disk. The side plate portion 3 is formed such that the inner peripheral edge of the opening hole 3a is farthest from the main plate portion 2 and gradually approaches the main plate portion 2 toward the outer peripheral edge.

  The wing part 4 is joined to the main plate part 2 and the side plate part 3 between the main plate part 2 and the side plate part 3. A plurality of wing parts 4 are provided, and are arranged radially at equal intervals with respect to the rotation axis C. The wing portion 4 connects the main plate portion 2 and the side plate portion 3 so that the center of the side plate portion 3 coincides with the rotation axis C and the main plate portion 2 and the side plate portion 3 face each other.

  In the present embodiment, for convenience of explanation, a configuration in which the main plate portion 2, the side plate portion 3, and the wing portion 4 are combined is referred to as a blade 10.

  In the turbofan 100, the blade 10 (the main plate portion 2, the side plate portion 3, and the wing portion 4) is rotated around the rotation axis C by rotating the boss portion 1 around the rotation axis C by a rotation drive source (not shown). Is done. Then, due to the action of the wing part 4, air is sucked in between the main plate part 2 and the side plate part 3 from the opening hole 3 a of the side plate part 3, and this air is directed toward the outer periphery from between the main plate part 2 and the side plate part 3. Be blown.

  In the turbofan 100 configured as described above, the hollow disk such as the side plate portion 3 is subjected to the highest stress on the inner peripheral edge of the opening hole 3a and the stress decreases toward the outer peripheral edge due to the centrifugal force during rotation. Therefore, as shown in FIG. 3, the side plate portion 3 is formed so that the plate thickness gradually decreases from the inner peripheral edge to the outer peripheral edge of the opening hole 3 a. As a result, the weight can be reduced and the strength and durability can be improved. Further, as shown in FIGS. 1 and 3, the side plate portion 3 is provided with a standing piece 3 b that rises outward so as to be separated from the main plate portion 2 at the inner peripheral edge of the opening hole 3 a. As a result, it is possible to prevent leakage of air while improving strength and durability.

  Further, in the turbo fan 100 having the above-described configuration, when rotating, the blade 10 (the main plate portion 2, the side plate portion 3, and the wing portion 4) has the boss portion 1 and the main plate portion at the center of gravity G as shown in FIG. 2, an axis perpendicular to the rotation axis C while passing through a joint point P (here, the center of the plate thickness of the main plate part 2 joined to the boss part 1 is a joint point P) at the joint part with the boss part 1. Centrifugal force F parallel to R works. This centrifugal force F is applied to the blade 10 as a tensile component force F1 in the direction of the centroid line L connecting the junction point P and the centroid G and a bending component force F2 in the direction perpendicular to the centroid line L. Regarding the centrifugal force F, the bending component force F2 becomes smaller as the axial distance h parallel to the rotation axis C from the axis perpendicular plane R to the center of gravity G shown in FIG. Becomes smaller. Moreover, if the bending component force F2 becomes small, the stress which generate | occur | produces in the main plate part 2, the side plate part 3, and the wing | blade part 4 which make the blade | wing 10 will also become small.

  As described above, in order to reduce the weight and improve the strength and durability of the side plate portion 3, the thickness of the inner peripheral edge of the opening hole 3 a where the stress is increased is increased and the stress is reduced toward the outer peripheral edge. The thickness is gradually reduced. In the case of the shape of the side plate portion 3, the center of gravity G of the blade 10 is located closer to the side plate portion 3 than the axis perpendicular plane R as shown in FIG. 5.

  Then, in order to shorten the axial distance h parallel to the rotation axis C from the axis perpendicular surface R to the center of gravity G, the main plate portion is outside the main plate portion 2 on the side away from the center of gravity G with respect to the axis orthogonal surface R. The plate thickness 2 is gradually increased from the center of rotation joined to the boss 1 toward the outer peripheral edge. As a result, the stress generated at the joint point P is reduced, the bending thickness of the main plate portion 2 is suppressed by relatively increasing the thickness of the outer peripheral edge of the main plate portion 2, and the stress generated in the wing portion 4 is also reduced. The As a result, the stress generated in the main plate portion 2, the side plate portion 3 and the wing portion 4 constituting the blade 10 is reduced, so that the weight can be reduced without excessively increasing the plate thickness, and the strength and durability of the turbofan 100 as a whole. It becomes possible to improve the property. In addition, the plate | board thickness of the main-plate part 2 changes gradually, and may be smooth continuously or may be stepped.

  In the above configuration, the main plate portion 2 may be formed of a material having a high density with respect to the side plate portion 3 and the wing portion 4. For example, the side plate portion 3 and the wing portion 4 are molded from a resin material (including integral molding and separate molding), and the main plate portion 2 is molded from a metal material and joined to the wing portion 4 to thereby form the side plate portion 3 and The wing part 4 is formed of a material having a relatively low density, and the main plate part 2 is formed of a material having a relatively high density. In this way, by using different materials having different densities for the side plate portion 3 and the wing portion 4 and the main plate portion 2, the center of gravity from the axis perpendicular to the axis R passing through the junction P between the boss portion 1 and the main plate portion 2. The axial distance h of G can be further shortened, and the strength and durability of the entire turbo fan 100 can be improved.

  In addition, as a structure which forms the main board part 2 with a material with a high density with respect to the side board part 3 and the wing | blade part 4, other than the combination of said resin material and a metal material, the side board part 3 and the wing | blade part 4 are made comparatively. It includes molding with a resin material having a low density, and molding the main plate portion 2 with a resin material having a relatively high density and joining the main plate portion 2 with the wing portion 4. Further, the side plate portion 3 and the wing portion 4 are formed from a metal material having a relatively low density, and the main plate portion 2 is formed from a metal material having a relatively high density and joined to the wing portion 4.

  By the way, in general, when the respective components are joined by welding or the like, the strength of the joined portion is lowered, and therefore, a portion requiring strength is preferably integrally formed. In the turbo fan 100 according to the present embodiment, the root portion 4a (see FIG. 3) of the wing portion 4 joined to the main plate portion 2 and the side plate portion 3 by centrifugal force, and the inner periphery of the opening hole 3a in the side plate portion 3 are provided. Since the generated stress becomes relatively high, when it is difficult to integrally form the main plate portion 2, the side plate portion 3, and the wing portion 4, the side plate portion 3 and the wing portion 4 are integrally formed, and the wing portion 4 and the main plate portion are formed. Joining 2 to each other by welding or the like is advantageous in terms of strength.

  In addition, as shown in FIG. 6, when the main plate portion 2 is formed in a shape like a reverse bowl shape in which the center side is curved and bulges inward, the axis of the center of gravity G from the axis perpendicular surface R The position of the junction point P may be set so that the directional distance h is as short as possible (or the axial distance h is 0). When the center of gravity G deviates from the axis perpendicular to the axis R, the plate thickness of the main plate portion 2 is changed as described above to make the axial distance h smaller.

  Although not clearly shown in the drawing, the thickness of the wing portion 4 can be reduced by forming the side plate portion 3 side thin and the main plate portion 2 side thick on the rotation axis C from the axis perpendicular to the center of gravity G to the center of gravity G. This is effective for shortening the parallel axial distance h.

  Although not clearly shown in the drawing, when the center of gravity G is located below the axis perpendicular to the axis R and far from the side plate portion 3 due to the shape of the blades 10, the rotation from the axis perpendicular to the axis R to the center of gravity G is performed. In order to shorten the axial distance h parallel to the axis C, the thickness of the main plate portion 2 is joined to the boss portion 1 on the inner side of the main plate portion 2 on the side away from the center of gravity G with respect to the axis perpendicular to the axis R. What is necessary is just to form gradually thicker toward the outer periphery from the center side of the rotation.

Embodiment 2. FIG.
The turbo fan 100 according to the second embodiment is configured when it is difficult to change the plate thickness itself of the main plate portion 2 or when the main plate portion 2 is formed of a steel plate having a single plate thickness. The configuration is the same as that of the first embodiment described above. Therefore, in the second embodiment described below, the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  In the turbofan 100 according to the second embodiment, as shown in FIG. 7, it is difficult to form the main plate portion 2 by changing the plate thickness itself, or the main plate portion 2 is made of a steel plate having a single plate thickness. In order to shorten the axial distance h of the center of gravity G from the axis perpendicular to the axis R, instead of changing the plate thickness of the main plate portion 2, the plate thickness including the main plate portion 2 is rotated by being joined to the boss portion 1. A plate material 7 is separately attached to the main plate portion 2 in such a manner that the thickness gradually increases from the center side toward the outer peripheral edge. In order to avoid the boss 1, the plate member 7 is configured as a hollow disc having an open center. The plate 7 as a hollow disc is formed such that the plate thickness including the main plate portion 2 is gradually increased from the center of rotation joined to the boss portion 1 toward the outer peripheral edge, and the center of gravity G from the axis perpendicular to the axis R is formed. If the axial distance h can be shortened, the number is not limited to one, and a plurality of sheets may be combined. When there are a plurality of plate members 7, the size of the opening of the hollow disk may not be the same or may be the same.

  Even with such a configuration, the plate thickness of the main plate portion 2 can be gradually increased from the center of rotation joined to the boss portion 1 toward the outer peripheral edge. As a result, the stress generated at the joint point P is reduced, the bending thickness of the main plate portion 2 is suppressed by relatively increasing the thickness of the outer peripheral edge of the main plate portion 2, and the stress generated in the wing portion 4 is also reduced. The As a result, the stress generated in the main plate portion 2, the side plate portion 3 and the wing portion 4 constituting the blade 10 is reduced, so that the weight can be reduced without excessively increasing the plate thickness, and the strength and durability of the turbofan 100 as a whole. It becomes possible to improve the property.

Embodiment 3 FIG.
The turbo fan 100 of the third embodiment is characterized in the joint portion between the main plate portion 2 and the wing portion 4 in the first embodiment or the second embodiment described above, and the other configurations are the same as those of the above-described embodiment. This is the same as 1 or Embodiment 2. Therefore, in the third embodiment described below, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the turbo fan 100 of the third embodiment, as shown in FIGS. 8 and 9, the side plate portion 3 and the wing portion 4 are integrally formed, and the wing portion 4 and the main plate portion 2 are joined. It is advantageous. In general, in the turbofan 100, the stress of the root portion 4a of the wing portion 4 joined to the main plate portion 2 and the side plate portion 3 is increased. Therefore, by integrally molding the side plate portion 3 and the wing portion 4, the strength of the root portion 4a of the wing portion 4 on the side plate portion 3 side becomes close to the base material of the wing portion 4. On the other hand, when the main plate part 2 and the wing part 4 are to be joined by welding or the like, the root part 4a having high stress overlaps with the joining part having reduced strength. It is desirable not to match.

  Therefore, as shown in FIG. 8, the overlay portion 21 protruding from the inner surface of the main plate portion 2 is formed as a part of the main plate portion 2 at the joint portion. And while the build-up part 21 is made into a concave shape in cross section, the root part 4a of the wing part 4 is made into a convex shape in cross section, and the concave part 21a of the build-up part 21 and the convex part 4b of the base part 4a are fitted and welded. . Alternatively, as shown in FIG. 9, the build-up portion 21 has a convex cross section, while the base portion 4 a of the wing portion 4 has a cross-sectional concave shape, and the convex portion 21 b of the build-up portion 21 and the concave portion 4 c of the base portion 4 a Fit and weld. In this way, by joining the main plate portion 2 and the root portion 4a of the wing portion 4 by fitting the concave and convex portions, the joint portion can be separated from the root portion 4a where the stress becomes high, and strength and durability can be increased. It is possible to avoid a drop.

  Further, since bending stress due to centrifugal force acts on the root portion 4 a of the wing portion 4, providing the build-up portion 21 also has an effect of increasing the strength of the wing portion 4. In addition, even if the build-up part 21 is not the case where the main board part 2 and the wing | blade part 4 are joined by uneven | corrugated fitting, as shown in FIG. 3, in the site | part used as the root part of the wing | blade part 4 in the main plate part 2. By providing, it is effective to shorten the axial distance h parallel to the rotation axis C from the axis perpendicular plane R to the center of gravity G.

  As described above, the turbofan according to the present invention is suitable for reducing the weight and improving the overall strength and durability.

DESCRIPTION OF SYMBOLS 1 Boss part 2 Main plate part 21 Overlay part 21a Concave part 21b Convex part 3 Side plate part 3a Opening hole 3b Standing piece 4 Wing part 4a Root part 4b Convex part 4c Concave part 7 Plate material 10 Blade 100 Turbo fan C Rotating shaft G Center of gravity P Joint point h Axial direction distance R Axis perpendicular plane L Center of gravity line F Centrifugal force F1 Tensile force F2 Bending force

Claims (5)

A boss portion fixed to the rotation shaft;
A main plate portion joined to the boss portion, a side plate portion having an opening hole serving as an air suction port at the center of rotation and disposed opposite to the main plate portion, and between the main plate portion and the side plate portion Blades composed of a plurality of wings arranged radially at equal intervals with respect to the rotation axis;
In a turbofan equipped with
In a mode in which the axial distance parallel to the rotation axis from the axis perpendicular to the rotation axis to the center of gravity of the blade is reduced while passing through the connection point at the connection portion between the boss part and the main plate part. The turbofan is characterized in that the thickness of the main plate portion is gradually increased from the center of rotation toward the outer peripheral edge.   The turbofan according to claim 1, wherein the main plate portion is formed of a material having a high density with respect to the side plate portion and the wing portion.   The turbofan according to claim 1, wherein the main plate portion is formed by overlapping plate materials.   The turbofan according to any one of claims 1 to 3, wherein the main plate portion and the wing portion are joined together by concave and convex fitting.   The turbofan according to any one of claims 1 to 4, wherein the main plate portion is formed with a built-up portion at a root portion to which the wing portion is joined.

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