JP2010059876A - Fan and motor driven blower equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fan for reducing the allowance of the coaxiality of axes passing through the centers of a front plate and a rear plate without reducing the blowing efficiency. <P>SOLUTION: A groove 42a is formed in the root of one of a first connection protrusion 42 of a blade 41 which is inserted through a front connection hole 34 of the front plate 32 and caulked, and a second connection protrusion of the blade 41 which is inserted through a rear connection hole of the rear plate and caulked. Into the groove 42a, a hole edge 34a of the front connection hole 34 or a hole edge of the rear connection hole can be inserted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a centrifugal fan and an electric blower including the fan and used as a negative pressure generation source of a vacuum cleaner, for example.

  Conventionally, an impeller is formed by connecting a front plate having an air intake portion (air intake port) in the center portion to the front edge of the blade and connecting a rear plate having a rotation shaft connecting hole in the center portion to the rear edge of the blade. (Fan) is known. The rear plate of the impeller is fixed to the rotating shaft of the electric motor passed through the rotating shaft connecting hole using a nut. Therefore, when the impeller is rotated at a high speed by driving the electric motor, the airflow sucked in from the intake port of the casing (fan cover) covering the impeller and flowing into the intake portion of the impeller is compressed and accelerated to exhaust the air around the impeller. The air blown to the part can be made.

The blade of the impeller and both plates are connected as follows. That is, the blade and the front plate are connected by caulking a plurality of protrusions integrally protruding from the front edge of the blade through a plurality of connection holes provided in the front plate corresponding to these. Similarly, the blade and the rear plate are connected by caulking a plurality of protrusions integrally protruding from the rear edge of the blade through the corresponding connection holes provided in the rear plate. Each protrusion which the blade has is formed straight, and the connection hole of both plates through which these blades are inserted is formed in a slit shape matching the shape of the protrusion (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 3-160196 (prior art column, problem to be solved by the invention, example column, and FIGS. 1 to 6)

  Since the fan is rotated at a high speed when it is used, it is desired to reduce the amount of unbalance of rotation as much as possible. When this unbalance amount is large, vibration of the electric blower and accompanying noise increase. At the same time, the load caused by the contact between the seal member attached to the rear surface of the edge of the air intake port of the fan cover and the edge of the air intake port of the front plate increases, and the air blowing efficiency of the electric blower decreases.

  The unbalanced amount of rotation of the fan is the degree of coaxiality (also referred to as concentricity) between the axis passing through the center of the air inlet of the front plate and the axis passing through the center of the rotating shaft connecting hole of the rear plate, that is, the above-mentioned. It is determined by the degree to which both axes do not match. This coaxiality depends on the accuracy of the mounting position of the front plate and the rear plate with respect to the blade.

  In the conventional fan, the adjustment of the mounting position of both plates with respect to the blade is only possible within the range of the fitting gap between the connecting hole of both plates and the protrusion of the blade inserted into the plate. Not suitable for reducing tolerance.

  As one of the measures for reducing the tolerance of the coaxiality, it is conceivable to enlarge the fitting hole between each plate and the projection of the blade by increasing the connecting hole of each plate. However, in this measure, since the connecting hole is large, it is not reliable to completely close the connecting hole with the caulking traces of the blade, and therefore, the portion where the connecting hole is not closed tends to remain as a hole. Therefore, when the fan is painted after its assembly, the part where the connection hole is not blocked becomes easy to be visually recognized as a hole, so not only the merchantability is impaired but also the part where the connection hole is not blocked. Part of the airflow that flows through the fan through the air leaks out of the fan, and the air blowing efficiency decreases.

  The objective of this invention is providing the electric fan provided with the fan which can make small the tolerance of the coaxiality of the axis line which passes along the center of a front plate and a rear plate, and this fan, without causing the fall of ventilation efficiency.

  The fan according to the present invention includes at least one of the first connection protrusion of the blade inserted through the front connection hole of the front plate and the second connection protrusion of the blade inserted through the rear connection hole of the rear plate. A groove is formed at the base of the protrusion, and a hole edge of the front connection hole or the rear connection hole can be inserted into the groove. The electric blower of the present invention is characterized by including the fan having the above-described configuration.

  In the fan of the present invention, the fitting gap between the connecting protrusion and the connecting hole through which the connecting protrusion is inserted without increasing the front connecting hole or the rear connecting hole is largely secured according to the depth of the groove of the protrusion. Using this fitting gap, the coaxiality of the axis passing through the center of the front plate and the rear plate can be adjusted.

  ADVANTAGE OF THE INVENTION According to this invention, the fan which can make small the tolerance of the coaxiality of the axis line which passes along the center of a front plate and a rear plate, and an electric blower provided with this fan can be provided, without causing the fall of ventilation efficiency.

  An embodiment of the present invention will be described with reference to FIGS.

  Reference numeral 1 in FIG. 1 indicates an electric blower that is built in, for example, a vacuum cleaner main body of a vacuum cleaner (not shown) and performs a dust-blowing operation. The electric blower 1 includes an electric motor frame 2, a stator 11, a rotor 15, a pair of brush devices 21, a centrifugal fan 31, a diffuser 47, a fan cover 51, and the like. The electric motor frame 2, the stator 11, the rotor 15, and the pair of brush devices 21 form an electric motor part M that forms an electric motor.

  The metal motor frame 2 is formed by connecting a frame body 3 and a frame end face plate 4 having a vent hole. The frame main body 3 is formed in a bottomed cylindrical shape, and the opening edge 3a is bent outwardly and has an annular shape. The frame end face plate 4 crosses the opening of the frame body 3, and both ends thereof are screwed to the opening edge 3a. A bearing 5 is housed in a bearing support portion 4 a formed at the center in the longitudinal direction of the frame end face plate 4. The end wall 3b of the frame body 3 is located on the side opposite to the opening of the frame body 3, and a bearing support portion 3c is formed at the center of the end wall 3b, and the bearing 6 is accommodated in the bearing support portion 3c. ing.

  The stator 11 includes a stator core 12, and the stator core 12 is annular and has a substantially square outer shape when viewed in plan. The stator core 12 is fixed in the motor frame 2 with its four corners being in pressure contact with the inner surface of the cylindrical peripheral wall of the frame body 3. An in-frame air passage 3d (only one is shown in FIG. 1) is formed between the outer surface of the stator core 12 and the inner surface of the cylindrical peripheral wall facing the stator core 12. A plurality of exhaust holes 3e (only one is shown in FIG. 1) are formed in the cylindrical peripheral wall located downstream of the in-frame air passage 3d, that is, between the stator 11 and the end wall 3b. .

  As shown in FIG. 1, the rotor 15 includes a rotating shaft 16, a laminated iron core 17 that forms an armature core fixed to the rotating shaft 16, a commutator 18 fixed to the rotating shaft 16, and a commutator 18. And a rotor winding 19 that forms an armature winding that is wound around the laminated iron core 17 by connecting a winding terminal portion.

  The rotor 15 is attached to the motor frame 2 through the inside of the stator 11 by rotatably supporting the rotating shaft 16 on the bearings 5 and 6. By this attachment, the commutator 18 is disposed between the laminated iron core 17 and the bearing 6. At the same time, the rotating shaft 16 penetrates the bearing 5 and the bearing support portion 4a and protrudes to the outside of the electric motor frame 2.

  As shown in FIG. 1, the pair of brush devices 21 are attached to the frame body 3 by being electrically insulated, and are provided so as to penetrate the frame body 3 in the radial direction. The carbon brushes 21a included in these brush devices 21 are pressed against the commutator 18 by coil springs 21b.

  The fan 31, the diffuser 47, and the fan cover 51 form a fan part F.

  As shown in FIGS. 1 and 3, the fan 31 includes a front plate 32, a rear plate 35, and a plurality of blades 41. The front plate 32, the rear plate 35, and the blade 41 are made of metal, preferably light metal, specifically aluminum or an alloy thereof. In FIG. 1 and FIG. 3, reference numeral 31 a indicates a discharge port of the fan 31, and the discharge port 31 a is formed in the outer peripheral portion of the fan 31.

  As shown in FIGS. 2 and 3, the front plate 32 is circular and has a circular air inlet 33 at the center thereof. A portion 32 a on the air suction port 33 side of the front plate 32 is bent at a steep inclination with respect to other portions, that is, the periphery of the air suction port 33, thereby forming a cylindrical shape.

  The front plate 32 has a plurality of front connection holes 34 (only one is shown in FIGS. 5 and 6) around the air suction port 33. These front connection holes 34 are slit-like long holes. Several front connection holes 34 are used as a set, and the front connection holes 34 of each set are arranged at intervals from each other so that the longitudinal direction thereof matches the direction in which the blade 41 extends.

  As shown in FIG. 3, the rear plate 35 is made of a flat knitted board having the same diameter as the front plate 32, and has a circular rotating shaft connecting hole 36 at the center thereof. The rotation shaft connection hole 36 has a smaller diameter than the air suction port 33.

  The rear plate 35 has a plurality of rear connection holes 37 formed of slit-like elongated holes around the rotation shaft connection hole 36. A part of these rear connection holes 37 is shown in FIG. Several rear connection holes 37 are used as a set, and the rear connection holes 37 of each set are aligned with the longitudinal direction thereof aligned with the direction in which the blade 41 extends and spaced from each other. Each rear connection hole 37 corresponds to each front connection hole 34. For example, as a preferable example, each rear connection hole 37 is provided to face the front connection hole 34 in the thickness direction of the fan 31, but each rear connection hole 37 is provided. The connection hole 37 and each front connection hole 34 may be provided so as not to face each other in the thickness direction of the fan 31.

  As shown in FIG. 4A, each blade 41 is bent in an arc shape. As shown in FIG. 4B, each of these blades 41 includes a plurality of first connecting projections 42 for caulking that integrally project from the front edge and a plurality of second connecting projections 43 for caulking that integrally project from the rear edge. Have. The first connection protrusions 42 are provided in the same arrangement corresponding to the front connection holes 34 of each set, and similarly, the second connection protrusions 43 correspond to the rear connection holes 37 of the sets. They are provided in the same arrangement.

  The first connection protrusion 42 is slightly smaller than the front connection hole 34, and the height of the protrusion is higher than the thickness of the front plate 32. Thereby, the front connection hole 34 and the first connection protrusion 42 can be fitted, and the first connection protrusion 42 is inserted into the front connection hole 34 in this fitted state. The dimension A in FIG. 5A is a state in which the respective axes passing through the centers of the first connection projection 42 and the front connection hole 34 are coincident, that is, the first connection projection 42 and the front connection so as to have a common axis. The dimensional difference of the longitudinal direction of the 1st connection protrusion 42 and the front connection hole 34 in the state by which the hole 34 is arrange | positioned is shown. Therefore, the total dimensional difference between the two is 2A. This dimensional difference 2A is set to the minimum necessary for fitting the front connecting hole 34 and the first connecting protrusion 42 together.

  As shown in FIGS. 4 (B), 5 (A), and 6, a groove 42a is formed at the base of the first connecting protrusion 42 over the entire circumference of the base. The groove 42a is provided using a press die. The width h of the groove 42a (the dimension along the protruding direction of the first connecting protrusion 42) is slightly larger than the thickness of the front plate 32. Therefore, the hole edge 34a of the front connection hole 34 can be inserted into the groove 42a. Note that a dimension B in FIGS. 5A and 6 indicates the depth of the groove 42a.

  The second connection protrusion 43 is formed in the same manner as the first connection protrusion 43. That is, the second connection protrusion 43 is slightly smaller than the rear connection hole 37, and the protrusion height is higher than the plate thickness of the rear plate 35. Therefore, the rear connection hole 37 and the second connection protrusion 43 can be fitted, and the second connection protrusion 43 can be inserted into the rear connection hole 37 in this fitted state. The longitudinal dimension difference (not shown) between the second coupling protrusion 43 and the rear coupling hole 37 is the same as the longitudinal dimension difference between the first coupling protrusion 42 and the front coupling hole 34.

  As shown in FIG. 4B, a groove 43a is formed at the base of the second connection protrusion 43 over the entire circumference of the base. The groove 43a is provided using a press die. The width of the groove 43a (the dimension along the protruding direction of the second connecting protrusion 43) is slightly larger than the thickness of the rear plate 35. Therefore, the hole edge (not shown) of the rear connection hole 37 can be inserted into the groove 43a. The depth of the groove 43a is the same as the depth of the groove 42a.

  The fan 31 is assembled as follows.

  First, the front plate 32, the rear plate 35, and the plurality of blades 41 are set on a jig (not shown). With this setting, each of the first connection protrusions 42 of each blade 41 is inserted into the corresponding front connection hole 34 of the front plate 32, and each of the second connection protrusions 43 of each blade 41 corresponds to the rear plate 35. These three members are temporarily assembled by being inserted into the rear connection hole 37. In this temporarily assembled state, each blade 41 is disposed across the two plates at right angles to the front plate 32 disposed at one end in the width direction and the rear plate 35 disposed at the other end in the width direction.

  In the temporary assembly, the three parties are positioned with a jig. Thereby, an axis line (not shown) passing through the center of the air suction port 33 of the front plate 32 (note that this center and the center of the front plate 32 are the same) and the center of the rotating shaft connecting hole of the rear plate 35 (note that The center and the center of the rear plate 35 are the same.) A coaxiality is secured so that an axis (not shown) passing through the center becomes a common axis.

  In this case, a fitting clearance between the first connection protrusion 42 and the front connection hole 34 through which the first connection protrusion 42 is inserted can be largely ensured according to the depth B of the groove 42a of the first connection protrusion 42, and the second connection protrusion 43 and Since the fitting clearance with the rear connection hole 37 through which this is inserted can be ensured largely according to the depth B of the groove 43a of the second connection projection 43, the tolerance of the coaxiality can be reduced.

  That is, with reference to FIGS. 5A and 5B, the relationship between the first connection protrusion 42 and the front connection hole 34 will be described as a representative. As shown in FIG. 5A, the total dimensional difference between the portion of the first connecting protrusion 42 excluding the groove 42 a and the front connecting hole 34 is 2 A, but the front plate 32 is properly combined with the blade 41. In this state, the size of the fitting gap between the hole edge 34a of the front connection hole 34 and the bottom of the groove 42a of the first connection protrusion 42 is 2 (A + B). That is, the size of the fitting clearance between the first connection protrusion 42 and the front connection hole 34 in a state where the coaxiality is secured is larger than the dimensional difference 2A by an amount corresponding to twice the depth B of the groove 42a. large. The size of the fitting gap formed by the total value of the dimensional difference A and the depth B of the groove 42a is indicated by a symbol G here.

  On the other hand, since the width h of the groove 42a is larger than the plate thickness of the front plate 32, when the parts of the fan 31 are positioned and temporarily assembled by a jig, the front plate 32 is connected to the first connection protrusion 42 and the front connection hole 34. It is possible to adjust the position of the front plate 32 by moving within the range indicated by the symbol G without being restricted by the dimensional difference A for allowing the fitting. Thus, the degree of freedom of moving the front plate 32 with respect to the first connection protrusion 42 of the blade 41, in other words, a large adjustment amount is ensured, so that the positioning accuracy of the front plate 32 with respect to the blade 41 is improved. Such an improvement in positioning accuracy can also be obtained for the positioning of the rear plate 35 with respect to the blade 41 for the same reason.

  Accordingly, the coaxiality is ensured so that the axis passing through the center of the air suction port 33 of the front plate 32 using the jig and the axis passing through the center of the rotating shaft coupling hole 36 of the rear plate 35 are a common axis. The

  Next, in the temporarily assembled state in which the coaxiality is ensured as described above, all of the first connection protrusions 42 of the blade 41 protruding from the front plate 32 and all of the second connections protruding from the rear plate 35. The protrusions 43 are simultaneously crimped by a press machine. By this caulking operation, the first connection protrusion 42 is crushed as shown in FIG. 5B, and plastically deforms over the front connection hole 34. Thereby, the front plate 32 is connected to the blade 41. At the same time, the rear plate 35 and the blade 41 are similarly connected.

  FIG. 5B shows a state in which the position adjustment of the front plate 32 with respect to the blade 41 is performed to the maximum and the second connection protrusion 42 is caulked. Even under such maximum position adjustment, the front connection hole 34 is completely covered by the plastically deformed first connection protrusion 42, so that a part of the front connection hole 34 is not blocked and remains as a hole. There is no.

  The reason is that the fitting gap G is not secured by enlarging the first connecting protrusion 42 but by providing a groove 42a at the base of the first connecting protrusion 42 so that the first connecting protrusion 42 is not enlarged. It depends on what you need to do. The same applies to the relationship between the rear connection hole 37 of the rear plate 35 and the second connection protrusion 43 caulked by the blade 41.

  Therefore, when the fan 31 is painted after the above fan 31 is assembled, a part of the front connection hole 34 and the rear connection hole 37 is visually recognized, and the merchantability is not impaired. At the same time, when the electric blower 1 is operated, a part of the airflow flowing in the fan 31 does not leak out of the fan 31 through the front connecting hole 34 and the rear connecting hole 37, so that the blowing efficiency can be improved.

  As described above, according to the fan 31 having the above-described configuration and the electric blower 1 including the fan 31, the tolerance of the coaxiality of the axis passing through the centers of the front plate 32 and the rear plate 35 is reduced without causing a reduction in the blowing efficiency. In addition to this, the unbalance amount of rotation of the fan 31 can be reduced accordingly. Therefore, vibration and noise of the electric blower 1 can be reduced, and a load caused by contact between a seal member 52 (to be described later) and an edge 33a (see FIGS. 2 and 3) of the air suction port 33 of the front plate 32 is reduced. Thus, the blowing efficiency of the electric blower 1 can be improved.

  As shown in FIG. 1, the shaft end portion of the rotating shaft 16 protruding outside the motor frame 2 is passed through the rotating shaft coupling hole 36 of the rear plate 35 of the assembled fan 31. The fan 31 is fixed to the rotating shaft 16 by tightening the screwed nut 45. In order to receive the tightening force of the nut 45, a ring-shaped spacer member (not shown) is interposed between the bearing support portion 4a and the rear surface of the central portion of the rear plate 35 so as to be sandwiched between them.

  As shown in FIG. 1, the diffuser 47 is disposed between the fan 31 and the electric motor frame 2, and is fixed to the frame end face plate 4 and the opening edge 3 a of the frame body 3. The diffuser 47 statically converts the airflow discharged from the discharge port 31 a of the fan 31 and guides it to the in-frame air passage 3 d of the motor frame 2.

  As shown in FIG. 1, the fan cover 51 is attached by fitting its peripheral portion to the opening edge 3 a of the electric motor frame 2, and covers the peripheral portion of the diffuser 47 and the fan 31. The fan cover 51 has a suction port 51 a facing the air suction port 33 at the center thereof. A ring-shaped sealing material 52 is attached to the rear surface of the edge of the suction port 51a. The seal material 52 is in contact with the edge 33 a of the air suction port 33 of the fan 31.

  The electric blower 1 having the above configuration can rotate the fan 31 together with the rotor 15 by energizing the electric motor unit M. As a result, the airflow flows through the suction port 51a, the fan 31, the diffuser 47, the in-frame air passage 3d, and the exhaust hole 3e in this order, and the air blowing operation for dust suction of the vacuum cleaner is performed.

  In the configuration of the one embodiment, since the positions where the front plate and the rear plate are attached to the blade can be adjusted respectively, it is possible to further reduce the allowable value of the coaxiality between the front plate and the rear plate. Excellent in terms. However, the present invention can be implemented only for at least one of the front plate and the rear plate. In this case, for example, only the adjustment of the mounting position of the front plate with respect to the blade can be performed. Moreover, an electric blower is not limited to the thing for vacuum cleaners, It can be used for another use.

The side view shown in the state where a part of electric fan provided with the fan concerning one embodiment of the present invention was notched. FIG. 2 is a front view showing a part of the fan included in the electric blower of FIG. 1. The side view shown in the state where a part of fan of FIG. 2 was notched. (A) is a top view which shows the braid | blade with which the fan of FIG. 2 is provided. (B) is a side view showing the blade. (A) is a figure which expands and shows F5 part in FIG.4 (B) with the partial cross section of a front plate. (B) is sectional drawing which shows the state by which the front plate was connected to F5 part in FIG. 4 (B). Sectional drawing shown along F6-F6 line in FIG. 5 (A).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric blower, M ... Electric motor part, 16 ... Rotating shaft, 31 ... Fan, 32 ... Front plate, 33 ... Air inlet, 33a ... Edge of air inlet, 34 ... Front connecting hole, 34a ... Front connecting hole Hole edge, 35 ... rear plate, 36 ... rotating shaft connecting hole, 37 ... rear connecting hole, 41 ... blade, 42 ... first connecting protrusion, 42a ... groove of first connecting protrusion, 43 ... second connecting protrusion, 43a ... Second connecting projection groove 51, fan cover 52, sealing material

Claims (2)

A front plate having an air suction port in the center and a plurality of front connection holes around the suction port, and a rotation shaft connection hole in the center and corresponding to the front connection hole around the connection hole A rear plate having a plurality of rear connection holes; a plurality of first connection protrusions that are caulked through the front connection holes; and a plurality of second connection protrusions that are caulked through the rear connection holes. In a fan comprising a plurality of blades sandwiched between the two plates and connecting these plates,
A groove into which a hole edge of the front connection hole or the rear connection hole into which the protrusion is inserted is formed at the base of at least one of the first connection protrusion and the second connection protrusion. A fan to do. An electric motor section having a rotating shaft;
2. The fan according to claim 1, wherein the rear plate is connected to the rotating shaft by screwing a nut into the rotating shaft passed through the rotating shaft connecting hole.
A fan that covers the fan and is supported by the electric motor unit, has a suction port in the center, and has a sealing material attached to the back of the edge of the suction port that contacts the edge of the air suction port of the fan A cover,
An electric blower comprising:

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