JP2014025367A - Electric blower and vacuum cleaner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric blower which is capable of performing fan case fixation at low cost and surely both in an axial direction and in a radial direction with excellent accuracy.SOLUTION: An electric blower of this invention is configured by including: a cylindrical shape part 5 at a flange folded cylindrical part 11 fitted with a fan case 1; and an inclination conical part 4 inclined in a small diameter direction from an end part side toward a root part, alternately disposed at two or more parts. An outer diameter of the cylindrical shape part 5 is equal to or more than the maximum outer diameter of the inclination conical part 4, and by holding the fan case 1 by the fitting with the flange folded cylindrical part 11, the fan case fixation can be performed surely in an axial direction and in a radial direction with excellent accuracy at low cost.

Description

  The present invention relates to an electric blower and a vacuum cleaner including the same.

  A conventional electric blower for an electric vacuum cleaner has a drive unit configured by rotatably sandwiching an armature by a bracket and a frame with a built-in field, and a centrifugal fan is attached to an armature rotating shaft protruding from the frame. A fan case is attached to the flange portion of the bracket so as to cover the fan and the air guide that guides the air emitted from the fan into the bracket.

  In a general electric blower, the fan case and the bracket are manufactured by pressing a steel plate from the viewpoint of ensuring strength and mass productivity. However, due to demands for weight reduction, a bracket formed from an alloy material made of aluminum or magnesium Although the electric blower which uses is also adopted, the mounting method of the fan case was the same form.

  As shown in FIG. 9 of Patent Document 1, an example of this configuration is a cylindrical flange folded cylindrical portion 11 in which the outer peripheral end of the flange portion of the bracket 2 is bent from the centrifugal direction toward the axial direction. The fan case outer peripheral cylindrical end 17 is press-fitted into the portion (see, for example, Patent Document 1).

Japanese Patent No. 4512619

  However, in the case of the conventional structure, the inner diameter of the fan case outer peripheral cylindrical end portion 17 and the outer diameter of the flange folded cylindrical portion 11 of the bracket 2 are contact-fitted all around, so that the cylindricity is highly accurate and fitted. If the allowance is not set to an appropriate fitting tolerance, there is a problem that the fan case 1 cannot be press-fitted into the bracket 2 and gets on or conversely falls off. In addition, when the press-fit holding force is low, there is a problem that not only the drop strength in the axial direction is lowered but also rotational movement in the radial direction.

  In addition, due to recent demands for weight reduction, the bracket 2 is manufactured by molding an alloy material using aluminum or magnesium having a low specific gravity, or the fan case outer peripheral cylindrical end 17 is set to be short so as to reduce the weight. Have been adopted.

  However, in the former case, a draft taper is always necessary, and particularly in the case of a magnesium alloy, a large draft taper of about 2 to 5 degrees is required. In the latter case, the bending cannot be sufficiently performed by the spring back, and the end of the fan case 1 has a trumpet shape that opens in the outer circumferential direction. Therefore, in both cases, since the contact portion with the fan case 1 is an inclined surface, the contact portion becomes a line contact, resulting in a decrease in holding force. In addition, since the fan case is press-fitted from the large diameter side of the inclined surface, there is a problem that the fan case rides on or becomes galling.

Further, the length of the fan case outer peripheral cylindrical end portion 17 is set so that the position of the fan case outer peripheral cylindrical end portion 17 after the fan case 1 is press-fitted into the bracket 2 is set substantially at the same position as the root position of the flange folded cylindrical portion 11. Can be shortened, and the weight and material cost can be reduced. However, a part of the outer peripheral cylindrical end 17 of the fan case is bent toward the center, and the flange-turned cylindrical portion 1 of the bracket 2 is folded.
There is a problem that it is difficult to prevent the cover 1 from being removed by covering the base side of the cover 1, and the drop strength is reduced.

  As a countermeasure, there is a method of making the inclined portion into a cylinder by cutting the outer periphery of the flange-turned cylindrical portion 11 of the bracket 2. However, contact fitting is performed on the entire periphery, and the cylindricity is increased as in the conventional configuration. If the accuracy and the fitting allowance are not set to an appropriate fitting tolerance, there is a problem that the fan case 1 cannot be press-fitted into the bracket 2 and gets up or falls off.

  Further, in the case of a molded product, a fitting portion with other parts such as a field core press-fitting portion and a bearing insertion portion also generates a taper and needs to be cut, and the degree of coaxiality with the flange-turned cylindrical portion 11 of the bracket 2 is required. It was very difficult to maintain high precision.

  The present invention solves the above-described conventional problems, and provides a highly reliable electric blower in which the fan case 1 is securely fixed to the bracket 2 with high accuracy, and a highly reliable electric vacuum cleaner equipped with the electric blower. For the purpose.

  In order to solve the above-described conventional problems, an electric blower of the present invention has a centrifugal fan attached to a rotating shaft of an armature, and a fan case mounted on a bracket that is molded with an alloy material using magnesium or aluminum. In the electric blower that is fitted and fixed, a flange folded cylindrical portion formed by bending the outer peripheral end of the bracket from the centrifugal direction toward the rotation axis direction on the fan side, and a fan case outer peripheral cylindrical end portion provided with the fan case, The flange folded cylindrical portion includes a cylindrical shape portion having a vertical arc surface substantially in the same direction as the rotation axis, and an inclination inclined in a small diameter direction from the end side of the flange folded cylindrical portion toward the root portion. The cylindrical portion is configured to have two or more conical portions alternately. The outer diameter of the cylindrical portion is greater than or equal to the maximum outer diameter of the inclined conical portion. The cylindrical case portion and the inclined conical portion are provided in the flange folded cylindrical portion, and the fan case is press-contacted with a part of the flange folded cylindrical portion. With this simple method, the area that requires high accuracy can be reduced, so that processing and management become easy, and coaxiality and cylindricity can be maintained with high accuracy. In addition, since the inclined cone part is non-contact or linear contact, the fan case outer peripheral cylindrical end can be bent to absorb the dimensions, so that a spring-like effect is produced, and the control range of the mating margin is increased. Even if it is spread out, the drop strength can be prevented from decreasing.

  The electric blower of the present invention can securely fix the fan case both in the axial direction and in the radial direction with low cost and accuracy.

DD sectional drawing of FIG. 2 which shows the electric blower in Embodiment 1 of this invention The AA sectional view of Drawing 1 showing an electric blower same The top view from the upper part of bracket 2 of the electric blower (A) The principal part enlarged view of the BB cross section of FIG. 1 which shows an electric blower, (b) The principal part enlarged view of the AA cross section of FIG. (A) The cross-sectional enlarged view which shows arrangement | positioning of the fan case outer periphery cylindrical end part 17 and the inclination cone part 4 of an electric blower, (b) The fan case outer periphery cylindrical end part 17 of an electric blower is the concave bending part 13 from the same. Cross-sectional enlarged view showing a state in contact with the bent inclined cone portion 4 Same part enlarged view of the upper left part of FIG. 1 showing the electric blower The cross-sectional enlarged view showing a state in which a large-diameter portion 14 is provided at an intermediate portion between the end portion and the root portion of the inclined cone portion 4 of the electric blower, and a gap is provided at each of the upper and lower end portions of the large-diameter portion 14. (A) The principal part sectional drawing which shows the inclination cone part 4 of the flange folding | turning cylindrical part 11 of the bracket 2 of an electric blower, (b) The main shape of the thickness of the flange folding cylindrical part 11 of the bracket 2 of an electric blower 23 is a cross-sectional view of a main portion showing the cutting surface 24 of the flange-turned cylindrical portion 11 of the bracket 2 of the electric blower. FIG. 11D is a cross-sectional view of the main portion of the flange-turned cylindrical portion of the bracket 2 of the electric blower. 11 is a cross-sectional view of the main part showing the cylindrical portion 5 and the inclined conical portion 4 after cutting. (A) Main part sectional drawing which shows the fitting state of the fan case outer periphery cylindrical edge part 17 of the conventional electric blower, and the flange folding | turning cylindrical part 11 (fan side bending), (b) Same as the fan case outer periphery cylinder of an electric blower Main part sectional drawing which shows the fitting state of the edge part 17 and the flange folding | returning cylindrical part 11 (non-fan side bending)

  The invention according to claim 1 is an electric blower having a centrifugal fan attached to a rotary shaft of an armature, and fitting and fixing a fan case to a bracket molded with an alloy material using magnesium or aluminum. A flange folded cylindrical portion formed by bending the outer peripheral end of the bracket from the centrifugal direction toward the rotation axis direction on the fan side, and a fan case outer circumferential cylindrical end portion provided with the fan case, wherein the flange folded cylindrical portion is Two or more alternating cylindrical portions having a vertical arc surface substantially in the same direction as the rotation axis and inclined conical portions inclined in the direction of decreasing diameter from the end side of the flange folded cylindrical portion toward the root And the outer diameter of the cylindrical portion is not less than the maximum outer diameter of the inclined conical portion, and the fan case is connected to the outer cylindrical end portion of the fan case and the frame. With a simple method of holding a cylindrical shape portion and an inclined conical portion in the flange folded cylindrical portion by holding it by fitting with the folded folded cylindrical portion, and making a press fit contact with the fan case at a part of the flange folded cylindrical portion, Since the area required for high accuracy can be reduced, processing and management are facilitated, and coaxiality and cylindricity can be maintained with high accuracy. In addition, since the inclined cone part is non-contact or linear contact, the fan case outer peripheral cylindrical end can be bent to absorb the dimensions, so that a spring-like effect is produced, and the control range of the mating margin is increased. Even if it is spread out, the drop strength can be prevented from decreasing.

  The invention according to claim 2 is a concave shape that is extruded from the outer peripheral side to the center side with respect to the fan case outer peripheral cylindrical end portion that is fitted in a state having a gap at the inclined conical portion, particularly in the first invention. A bent portion is provided, the inner diameter of the tip of the concave bent portion is set smaller than the outer diameter of the tip of the inclined cone, and the tip of the concave bent portion is in contact with the vicinity of the base of the inclined cone. The fan case outer peripheral cylindrical end is inclined by a simple method in which a fan case outer peripheral cylindrical end having a gap with the base side of the flange folded cylindrical portion is pushed toward the center to provide a concave bent portion. Not only does it cover the conical part and prevent it from coming off in the axial direction, but also the cylindrical part in the flange-turned cylindrical part acts as a stopper to prevent rotation in the rotational direction. Do not perform fixed. Further, since the gap passage generated between the inclined cone portion and the cylindrical portion can be narrowed, the leakage wind passing through the clearance can be prevented, and the suction force can be reduced and the noise increase due to the leakage wind can be prevented.

  The invention according to claim 3 is the first invention, in particular, in the first invention, a large-diameter portion is provided at an intermediate portion between the end portion and the root portion of the inclined cone portion, and the diameter between the fan case outer peripheral cylindrical end portion and the inclined cone portion is set. By having a gap at each of the upper and lower ends of the most part, it is possible to provide a large diameter portion at the end of the inclined conical portion of the flange folded cylindrical portion and the intermediate portion of the root portion. The risk of being caught at the end when the fan case is press-fitted can be reduced, and the press-fitting from the smooth insertion becomes possible, improving the productivity. In addition, the inclined conical section has inclined surfaces on both the upper and lower sides from the large diameter part, so that the difference between the maximum outer diameter and the minimum outer diameter is reduced, and the gap passage between the fan case and the bracket can be narrowed. This can prevent leakage of the wind and reduce the suction force and increase the noise caused by the leakage. Furthermore, the inclination angle of the inclined cone portion can be increased, and the effect as a stopper for preventing the fan case from being removed can be increased.

  The invention according to claim 4 is arranged so as to be substantially line symmetrical when the plurality of cylindrical portions and the plurality of inclined conical portions are viewed from the axial direction, particularly in any one of the first to third inventions. As a result, the fan case and the bracket are evenly held, and the fan case can be stably held. Moreover, since the fan case edge part bending part is also equal, more stable holding can be realized.

  The invention according to claim 5 is the inclined portion, particularly in any one of the first to fourth inventions, by setting the ratio of the cylindrical portion in the overall circumferential length of the flange folded cylindrical portion of the bracket to 50 to 70%. Therefore, the ratio of the cylindrical portion is set to be higher than that, so that both the securing of the fan case pull-out strength and the reduction of the press-fit resistance can be achieved.

  The invention according to claim 6 provides a highly reliable vacuum cleaner by mounting the electric blower according to any one of the first to fifth inventions on the vacuum cleaner.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiment.

(Embodiment 1)
The configuration of the electric blower will be described with reference to FIG. A general electric blower for a vacuum cleaner forms a drive unit by sandwiching an armature 9 between a bracket 2 having a built-in field 10 and a frame 8, and the armature 9 protruding from the frame 8 rotates. A centrifugal fan 6 is attached to the shaft 16, and the fan case 1 is mounted on the flange 2 of the bracket 2 so as to cover the centrifugal fan 6 and the air guide 7 that guides the air from the centrifugal fan 6 into the bracket 2. Is attached. The fan case 1 is formed by pressing a steel plate.

  The flange-turned cylindrical portion 11 has a cylindrical shape in which the outer peripheral end is bent from the centrifugal direction toward the rotation axis direction on the fan side, and the fan case outer peripheral cylindrical end portion 17 is press-fitted into that portion. .

  The flange-folded cylindrical portion 11 of the conventional electric blower is bent on the fan side as shown in FIG. 9 (a) or bent on the anti-fan side as shown in FIG. 9 (b). Exists. Further, the fan case outer peripheral cylindrical end portion 17 is set as short as possible in the rotational axis direction for weight reduction, and the position of the fan case outer peripheral cylindrical end portion 17 in the rotational axis direction after press-fitting the fan case 1 into the bracket 2 is the bracket. In many cases, the arrangement is set substantially on the same plane as the lower end position of the second flange-turned cylindrical portion 11.

  However, in the case of the above-described conventional configuration, the inner diameter of the fan case outer peripheral cylindrical end portion 17 and the outer diameter of the flange folded cylindrical portion 11 of the bracket 2 are contact-fitted all around, so that the cylindricity is highly accurate and fitted. If the fitting tolerance, which is a joint allowance, is not set appropriately, there is a problem that the fan case 1 cannot be press-fitted into the bracket 2 and climbs up or falls off.

  Further, when the press-fit holding force is low, there is a problem that not only the axial pull-out strength is reduced but also rotational movement in the radial direction is caused. Further, since the fan case outer peripheral cylindrical end portion 17 is set to be short in the rotation axis direction, a part of the fan case outer peripheral cylindrical end portion 17 is bent to the center side, and the lower end side of the flange folded cylindrical portion 11 of the bracket. It has become difficult to prevent the cover from being slipped off, resulting in a decrease in the pull-out strength.

1-4, the structure of the electric blower of this invention is demonstrated. The electric blower for an electric vacuum cleaner according to the present invention has a flange-folded cylindrical portion 11 in which the outer peripheral end of the flange portion of the bracket 2 is bent from the centrifugal direction toward the fan-side rotating shaft. A cylindrical portion 5 having a vertical arc surface and a mortar-shaped inclined conical portion 4 inclined in a small diameter direction from the end side of the flange folded cylindrical portion 11 toward the root portion, A plurality of inclined cone portions 4 are provided, and the fan case outer peripheral cylindrical end portion 17 is press-fitted into the cylindrical portion 5.

  By adopting this configuration, the number of contact points between the fan case outer peripheral cylindrical end portion 17 and the flange folded cylindrical portion 11 of the bracket 2 that require high accuracy can be reduced, so that processing and management are facilitated, and the coaxiality and cylindricity are reduced. High accuracy can be maintained.

  Further, since the contact between the inclined cone portion 4 and the fan case outer peripheral cylindrical end portion 17 is non-contact or linear contact, the fan case outer peripheral cylindrical end portion 17 is curved at this portion so that the dimensions can be absorbed. As a result, the dropout strength can be prevented from being lowered even if the control range of the mating margin is widened.

  In the formation of the inclined cone portion 4 and the cylindrical portion 5, when the bracket 2 is formed by die-casting an alloy material using magnesium or aluminum, it is formed as follows.

  As shown in FIG. 8 (a), the inclined conical portion 4 is formed with a core at the inner peripheral side of the flange-turned cylindrical portion 11, a cavity at the outer peripheral side, and a part portion 20, with a taper of about 2 to 5 degrees. Configure. That is, the inclined surface a <b> 21 of the inclined cone portion 4 is set by the draft taper angle.

  Subsequently, as shown in FIG. 8B, the cylindrical portion 5 has a shape in which the inner peripheral side of the flange-turned cylindrical portion 11 is the core, the outer peripheral side is the cavity, and the part portion 20, and the taper is 2 to 5 degrees. The main shape 23 of the compacted wall is configured as a pre-cutting stage. The inclined surface b22 of the main shape 23 of the compacted wall at this stage protrudes from the inclined surface a21 of the inclined cone portion 4 to the outer periphery, and is set at an angle of the taper similarly to the inclined cone portion 4.

  Next, as shown in FIG. 8C, the circumference of the thick main shape 23 is circled by a cutting surface 24 that is straight in the direction of the rotation axis 16 with a radius close to the inclined surface a21 of the inclined cone portion 4. By removing in the direction, the cylindrical portion 5 having the vertical surface 25 in the same direction as the rotation shaft 16 is formed.

  By such a forming method, as shown in FIG. 8 (d), the inclined surface a21 of the inclined cone portion 4 is formed in a state where the molded taper is utilized, and the cylindrical portion 5 has a vertical surface 25. Formed with. However, these do not limit the manufacturing method, and the shapes of the inclined cone portion 4 and the cylindrical portion 5 may be realized by press molding.

  Further, as shown in FIGS. 5 and 6, the outer periphery of the fan case outer peripheral cylindrical end 17 fitted with the gap 12 in the inclined conical portion 4 of the flange folded cylindrical portion 11 of the bracket 2 is By providing a concave bent portion 13 extruded from the side to the center side, and setting the inner diameter of the distal end portion of the concave bent portion 13 to be smaller than the outer diameter of the distal end portion of the inclined cone portion 4, the distal end of the concave bent portion 13 is provided. The portion contacts the vicinity of the base of the inclined cone portion 4.

  With this configuration, the fan case outer peripheral cylindrical end 17 in the range of the concave bent portion 13 covers the inclined conical portion 4, and not only prevents the fan case 1 from coming off in the rotation axis direction. Instead, the cylindrical portion 5 in the flange-turned cylindrical portion 11 abuts on the concave bent portion 13, thereby serving as a stopper for preventing rotation of the fan case 1, and can be reliably fixed.

  Moreover, since the clearance path which generate | occur | produces in the inclination cone part 4 and the cylindrical-shaped part 5 can be narrowed, the leakage wind which passes a clearance gap can be prevented and a suction force fall and the noise increase by a leakage wind can be prevented.

  In addition, as shown in FIG. 7, the inclined conical portion 4 is provided with a large-diameter portion 14 at an intermediate portion between the end portion and the root portion, so that a gap between the fan case outer peripheral cylindrical end portion 17 and the inclined conical portion 4 is reduced. A gap is provided at each of the upper and lower end portions of the large-diameter portion 14.

  By adopting this configuration, when the fan case 1 is press-fitted, the inner diameter of the end of the inclined cone 4 is smaller than the inner diameter of the fan case due to the reverse inclined surface. Productivity can be reduced, and press-fitting from smooth insertion becomes possible, improving productivity.

  Further, the inclined conical portion 4 has inclined surfaces on both sides in the vertical direction from the large-diameter portion 14, so that a narrow gap between the inclined surfaces on both sides and the fan case outer peripheral cylindrical end 17 exhibits the effect of a labyrinth seal, It is possible to prevent leakage from passing through the gap, and it is possible to prevent a reduction in suction force and increase in noise due to leakage. Furthermore, the inclination angle on the base side of the inclined cone portion 4 can be increased, and the effect of preventing the fan case from falling off can be further exhibited.

  Further, as shown in FIG. 3, by arranging the plurality of cylindrical portions 5 and the plurality of inclined conical portions 4 in the flange folded cylindrical portion 11 substantially in line symmetry, the fan case outer peripheral cylindrical end 17 and the flange folded back are arranged. The contact portion with the cylindrical portion 11 is kept in balance.

  By adopting this configuration, when the fan case 1 and the bracket 2 are fitted, the load can be evenly distributed, and the fan case 1 can be prevented from being distorted or disconnected.

  Further, as shown in FIG. 3, the ratio of the total cylindrical portion 5 to the entire circumferential length of the flange folded cylindrical portion 11 is set to 50 to 70%, and the fan case outer circumferential cylindrical end portion 17 and the flange folded cylindrical portion 11 are set. By limiting the contact area with the fan case 1, it becomes possible to achieve both the removal strength and workability of the fan case 1.

  Moreover, by mounting the electric blower having the configuration of the present embodiment on a vacuum cleaner, a more reliable vacuum cleaner is provided.

  As described above, the electric blower according to the present invention can fix the fan case with high accuracy, can reliably fix the axial direction and the radial direction, and can improve the reliability. And can be applied to commercial vacuum cleaners.

DESCRIPTION OF SYMBOLS 1 Fan case 2 Bracket 4 Inclined cone part 5 Cylindrical part 6 Centrifugal fan 8 Frame 9 Armature 11 Flange folding cylinder part 12 Gap 13 Concave bending part 14 Large diameter part 16 Rotating shaft 17 Fan case outer periphery cylindrical edge part

Claims (6)

An electric blower having a centrifugal fan attached to a rotating shaft of an armature and having a fan case fitted and fixed to a bracket molded with an alloy material using magnesium or aluminum. A flange folded cylindrical portion formed by bending toward the rotation axis direction of the side,
A fan case outer peripheral cylindrical end provided with the fan case, and
The flange folded cylindrical portion includes a cylindrical portion having a vertical arc surface substantially in the same direction as the rotation axis, and an inclined conical portion inclined in a small diameter direction from the end side of the flange folded cylindrical portion toward the root portion. Is composed of two or more places alternately,
The outer diameter of the cylindrical portion is equal to or greater than the maximum outer diameter of the inclined cone portion, and the fan case is held by fitting the outer peripheral cylindrical end portion of the fan case and the flange-turned cylindrical portion. Electric blower. The fan case outer peripheral cylindrical end fitted with a gap at the inclined conical portion is provided with a concave bent portion pushed out from the outer peripheral side to the center side, and the inner diameter of the tip end of the concave bent portion is 2. The electric blower according to claim 1, wherein the electric blower is configured to be smaller than an outer diameter of a tip portion of the inclined cone portion, and a tip portion of the concave bent portion is in contact with a vicinity of a root of the inclined cone portion. A large-diameter portion is provided at an intermediate portion between the end portion and the root portion of the inclined cone portion, and there is a gap between the upper and lower end portions of the large-diameter portion between the fan case outer peripheral cylindrical end portion and the inclined cone portion. The electric blower according to claim 1 configured as described above. The electric blower according to any one of claims 1 to 3, wherein the plurality of cylindrical portions and the plurality of inclined cone portions are arranged so as to be substantially line-symmetric when viewed from the axial direction. The electric blower according to any one of claims 1 to 4, wherein the ratio of the cylindrical portion in the entire circumference of the flange-turned cylindrical portion of the bracket is set to 50 to 70%. An electric vacuum cleaner comprising the electric blower according to any one of claims 1 to 5.

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