Balancing weight manufacturing method, balancing weight, and blower

Abstract

The invention provides a method for manufacturing a balance weight, a balance weight, and a blower. In the method for manufacturing the balance weight, the balance weight for adjusting the balance of the rotating body is formed on the rotating body, and the method for manufacturing the balance weight comprises the following steps: a coating step of coating the molten balance weight on the rotating body; a blowing step of blowing air to the balance weight coated on the rotating body to expand the balance weight on the rotating body; and a curing step for curing the balance weight.

Description

Technical Field

[0001] The invention relates to a manufacturing method of a balancing weight, a balancing weight and a blower. Background Art

[0002] There is known a motor in which a balancing weight is applied to a rotor yoke to correct unbalanced rotation of the rotor yoke (for example, Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2001-298929

[0004] In the above-mentioned motor, when the balance weight is applied to the rotor yoke by a scraper or the like, the thickness of the balance weight tends to become thicker, and it is difficult to increase the surface area of ​​the balance weight. Therefore, in the conventional motor, the man-hours for curing the balance weight tend to increase, resulting in an increase in the man-hours for manufacturing the balance weight. Summary of the invention

[0005] In view of the above circumstances, one aspect of the present invention has as one object to provide a method for manufacturing a balancing weight, a balancing weight, and a blower capable of suppressing an increase in the number of steps for manufacturing the balancing weight.

[0006] One embodiment of the present invention is a method for manufacturing a balancing weight, in which a balancing weight for adjusting the balance of a rotating body is molded on a rotating body, wherein the method for manufacturing the balancing weight includes the following steps: a coating step, in which the molten balancing weight is coated on the rotating body; a blowing step, in which air is blown to the balancing weight coated on the rotating body to expand the balancing weight on the rotating body; and a curing step, in which the balancing weight is cured.

[0007] One embodiment of the present invention is a balancing weight that adjusts the balance of a rotating body that can rotate around a central axis, wherein the balancing weight is molded on a molded surface on the side facing a first direction on the outer side surface of the rotating body, and a central portion of the balancing weight in a second direction that is a direction perpendicular to the first direction protrudes toward one side of the first direction, and a dimension of the balancing weight in the first direction is smaller than a dimension in the second direction.

[0008] One embodiment of the present invention is a blower having: the above-mentioned balance weight; a rotor rotatable about a central axis; and an impeller connected to the rotor and rotatable about the central axis. The rotating body is composed of the rotor and the impeller.

[0009] According to one aspect of the present invention, in a method for manufacturing a balance weight, a balance weight, and a blower, it is possible to suppress an increase in the number of steps required to manufacture the balance weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a top view which shows the air blower which concerns on 1st Embodiment.

[0011] Figure 2 The blower according to the first embodiment is shown. Figure 1 II-II sectional view.

[0012] Figure 3 It is a perspective view showing the impeller part according to the first embodiment.

[0013] Figure 4 It is a cross-sectional view showing the balance weight according to the first embodiment.

[0014] Figure 5 1 is a flowchart showing the method for manufacturing the balance weight according to the first embodiment.

[0015] Figure 6 This is a first cross-sectional view showing the method for manufacturing the balance weight according to the first embodiment.

[0016] Figure 7 This is a second cross-sectional view illustrating the method for manufacturing the balance weight according to the first embodiment.

[0017] Figure 8 It is a cross-sectional view showing a balance weight according to a second embodiment.

[0018] Description of symbols

[0019] 10, 210: blower; 12: rotating body; 20: rotor; 60: impeller part; 61a: first outer side surface; 61c: groove part; 61d: molding surface; 65, 265: balance weight; 65a: resin part; 65b: powder; 266, 267: molding layer; A: air; D1: first direction; D2: second direction; J: center axis; S03: coating process; S04: blowing process; S05: curing process. DETAILED DESCRIPTION

[0020] Hereinafter, the blower of the embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical concept of the present invention. In addition, in the following drawings, in order to facilitate the understanding of each structure, the scale, number, etc. in each structure are sometimes different from the actual structure.

[0021] In the following description, the XYZ coordinate system is appropriately shown in the figure as a three-dimensional orthogonal coordinate system. The Z-axis direction represents the direction in which the central axis J of the rotating body extends. The central axis J shown in each figure is an imaginary axis. In the following description, the direction parallel to the Z-axis direction is referred to as the "axial direction". The radial direction centered on the central axis J is referred to as the "radial direction". The circumferential direction centered on the central axis J is referred to as the "circumferential direction". The side (+Z side) to which the arrow of the Z-axis in the axial direction points is referred to as the "upper side". The opposite side (-Z side) to which the arrow of the Z-axis in the axial direction points is referred to as the "lower side". In addition, the upper side and the lower side are only names used to illustrate the relative positional relationship of each part, and the actual configuration relationship, etc. may also be a configuration relationship other than the configuration relationship represented by these names. The X-axis direction is a direction perpendicular to the Z-axis direction. The Y-axis direction is a direction perpendicular to both the Z-axis direction and the X-axis direction. In each figure, the circumferential direction is represented by an arrow θ.

[0022] The first direction D1 appropriately shown in each figure is the direction that the molding surface of the rotating body faces. In the present embodiment, the molding surface is the surface on which the balancing weight is molded. In the present embodiment, the first direction D1 is a direction parallel to the axial direction. The first direction D1 may be a direction intersecting the axial direction. In the following description, the side (+D1 side) to which the arrow of the first direction D1 points is referred to as "one side of the first direction D1", and the opposite side (-D1 side) to which the arrow of the first direction D1 points is referred to as "the other side of the first direction D1". The second direction D2 appropriately shown in each figure is a direction intersecting the first direction D1. In the present embodiment, the second direction D2 is a direction perpendicular to the first direction D1.

[0023] <First embodiment>

[0024] Figure 1 The blower 10 of the present embodiment shown in FIG. 1 is used, for example, as an electric cooling fan for air cooling electronic equipment. The blower 10 of the present embodiment is an axial flow fan that blows air in the axial direction. Figure 2 As shown, the blower 10 includes a motor 15, a housing 50, an impeller 60, and a balance weight 65. In addition, the blower 10 includes a rotating body 12.

[0025] The impeller portion 60 is rotatable about the central axis J. The impeller portion 60 includes an impeller cup 61 and a plurality of wing portions 62. The impeller cup 61 is substantially cylindrical and extends axially about the central axis J. The impeller cup 61 is open at the bottom. The motor 15 is accommodated inside the impeller cup 61. The impeller cup 61 includes a first outer side surface 61a, a groove portion 61c, and a molding surface 61d.

[0026] The first outer side surface 61a is a surface facing one side (+D1 side) of the outer side surface of the impeller portion 60 in the first direction D1. Figure 3 As shown, when viewed from the axial direction, the first outer side surface 61a is roughly circular with the central axis J as the center. The groove portion 61c is a groove that is recessed from the first outer side surface 61a to the other side (-D1 side) of the first direction D1. When viewed from the axial direction, the groove portion 61c is annular with the central axis J as the center. The groove portion 61c extends over the entire circumference along the circumferential direction. The molding surface 61d is a surface on the side facing the first direction D1 among the outer side surfaces of the impeller portion 60. In the present embodiment, the molding surface 61d is a surface on the side facing the first direction D1 among the inner side surfaces of the groove portion 61c. When viewed from the axial direction, the molding surface 61d is annular. The molding surface 61d extends over the entire circumference along the circumferential direction.

[0027] A plurality of wing portions 62 protrude radially outward from the outer peripheral surface of the impeller cup 61. Figure 1 As shown, the impeller portion 60 has five wing portions 62. The wing portions 62 are arranged in a circumferential direction along the outer peripheral surface of the impeller cup 61. When the impeller portion 60 rotates around the central axis J, the wing portions 62 send air in the axial direction.

[0028] like Figure 2 As shown in FIG. 1 , the housing 50 accommodates the motor 15 and the impeller 60 therein. The housing 50 holds the motor 15 and the impeller 60. The housing 50 has a peripheral wall portion 51 and a motor holding portion 55. Figure 1 and Figure 2 As shown in FIG. 5 , the peripheral wall portion 51 is in the shape of a square tube extending in the axial direction. Figure 2 As shown, the peripheral wall portion 51 surrounds the impeller portion 60 and the motor 15 from the radially outer side. The motor holding portion 55 has a cylindrical shape extending in the axial direction around the central axis J. The motor holding portion 55 is arranged inside the impeller cup 61 .

[0029] The motor 15 is housed inside the peripheral wall portion 51. The motor 15 includes a rotor 20, a shaft 23, a first bearing 24a, a second bearing 24b, a rotor bearing 25, a stator 30, and a circuit board 70. The motor 15 of the present embodiment is a motor in which an outer rotor of the rotor 20 is arranged radially outside the stator 30. The rotor 20 can rotate around the central axis J. The rotor 20 is held on the inner circumferential surface of the impeller cup 61. Thus, the impeller portion 60 is connected to the rotor 20. When the rotor 20 rotates around the central axis J, the impeller portion 60 rotates around the central axis J. The rotor 20 includes a magnet 22.

[0030] The shaft 23 is cylindrical and extends axially with the central axis J as the center. The shaft 23 is arranged inside the motor holding portion 55. The upper part of the shaft 23 is held rotatably by the first bearing 24a. The lower part of the shaft 23 is held rotatably by the second bearing 24b. The first bearing 24a and the second bearing 24b are respectively held on the inner circumferential surface of the motor holding portion 55. Thus, the shaft 23 can rotate around the central axis J. The rotor bearing 25 is roughly cylindrical with the central axis J as the center. The shaft 23 is inserted into the rotor bearing 25 in the axial direction. A portion including the upper end of the shaft 23 is embedded in the rotor bearing 25. The rotor bearing 25 supports the rotor 20 so that it can rotate around the central axis J.

[0031] The stator 30 has an annular shape surrounding the central axis J. The stator 30 is disposed inside the rotor 20. The stator 30 faces the magnet 22 with a gap therebetween in the radial direction. The stator 30 includes a stator core 31, a coil portion 35, an insulator 40, and a connection pin 80.

[0032] The stator core 31 is in the shape of a ring surrounding the central axis J. The stator core 31 has a core back 32 and a plurality of teeth 33. The core back 32 is in the shape of a ring centered on the central axis J. The core back 32 is fixed to the outer peripheral surface of the motor retaining portion 55. Each tooth 33 protrudes radially outward from the outer peripheral surface of the core back 32. Although not shown in the figure, each tooth 33 is arranged at intervals along the outer peripheral surface of the core back 32. The insulator 40 insulates the stator core 31 from the coil portion 35. The insulator 40 is mounted on the stator core 31.

[0033] The connecting pin 80 is in the shape of a column extending in the axial direction. The connecting pin 80 is conductive. Although not shown in the figure, the stator 30 has two connecting pins 80. Each connecting pin 80 is held by the insulating member 40. Although not shown in the figure, the lower end of each connecting pin 80 is connected to the circuit board 70.

[0034] The coil portion 35 is electrically connected to the circuit board 70 via the connection pin 80. When current is supplied from the circuit board 70 to the coil portion 35, a rotation torque is generated on the rotor 20 by the magnetic force between the magnetic poles of the electromagnet formed by the stator 30 and the magnet 22. The coil portion 35 has a plurality of coil main bodies 36 and coil lead wires 38.

[0035] Each coil body 36 is mounted on a different tooth portion 33 of the stator core 31 via an insulating member 40. A coil lead wire 38 is led out from the coil body 36. Although not shown in the figure, in the present embodiment, the stator 30 has two coil lead wires 38. Each coil lead wire 38 is connected to a different connecting pin 80. Thus, the coil portion 35 is electrically connected to the circuit board 70 via the connecting pin 80.

[0036] The circuit board 70 is disposed below the stator core 31. The circuit board 70 is in the shape of a plate extending in a direction perpendicular to the axial direction. As described above, the circuit board 70 is connected to the connection pin 80. The circuit board 70 supplies current to the coil portion 35 via the connection pin 80.

[0037] In the present embodiment, the rotating body 12 is a component that can rotate around the central axis J among the components of the blower 10. In the present embodiment, the rotating body 12 is composed of an impeller portion 60 and a rotor 20. In the present embodiment, a balancing weight 65 is molded on the rotating body 12. In the present embodiment, as described later, the balancing weight 65 is molded on the impeller portion 60. The balancing weight 65 may be molded on the rotor 20, or may be molded on the impeller portion 60 and the rotor 20 separately.

[0038] like Figure 3 As shown in FIG. 1 , the balance weight 65 is disposed inside the groove portion 61 c of the impeller portion 60. Figure 4 As shown, the balancing weight 65 is molded on the molding surface 61d. In the present embodiment, the balancing weight 65 is a weight for adjusting the balance of the rotating body 12. The balancing weight 65 of the present embodiment is composed of one molding layer. The number of layers Na of the balancing weight 65 of the present embodiment is 1. By molding a balancing weight 65 of a specified weight at a specified position in the circumferential direction of the molding surface 61d, the deviation of the center of gravity position of the rotating body 12 relative to the central axis J can be reduced. Thus, the rotating body 12 can stably rotate around the central axis J. In addition, the impeller portion 60 may not have the groove portion 61c. In this case, the balancing weight 65 may also be molded on the first outer surface 61a. In addition, the balancing weight 65 may also be molded on the rotor 20. For example, when the balancing weight 65 is formed on the radial surface of the rotor 20, the first direction D1 is a direction perpendicular to the axial direction, and the second direction D2 is a direction perpendicular to the radial direction.

[0039] In this embodiment, the balance weight 65 includes a metal powder 65b and a resin portion 65a containing the powder 65b. As a material constituting the powder 65b, metals such as tungsten and stainless steel can be used. The resin portion 65a is composed of a thermoplastic resin. As a material constituting the resin portion 65a, a thermoplastic resin such as polyethylene, polypropylene, and polyvinyl chloride can be used.

[0040] The balancing weight 65 of this embodiment is in the shape of a mountain that protrudes from the molding surface 61d to one side (+D1 side) in the first direction D1. More specifically, the dimension L1 of the balancing weight 65 in the first direction D1 is smaller than the dimension L2 in the second direction D2. In addition, the central portion of the balancing weight 65 in the second direction D2 protrudes to one side in the first direction D1. In addition, the portion of the balancing weight 65 on one side in the first direction D1 is in the shape of a plane that is narrow in the second direction D2. The balancing weight 65 is in the shape of a curved surface whose hem extends in the second direction D2. Figure 3 As shown, the surface of the balance weight 65 facing the first direction D1 is arranged at a distance from the first outer side surface 61 a.

[0041] Next, a manufacturing method Mb of the balancing weight 65 of the present embodiment will be described. In the manufacturing method Mb of the balancing weight 65, the balancing weight 65 is molded on the rotating body 12. Figure 5 As shown, the manufacturing method Mb of the balancing weight 65 of the present embodiment includes the following steps: a first inspection step S02, which inspects the balance of the rotating body 12; a coating step S03, which coats the melted balancing weight 65 on the rotating body 12; a blowing step S04, which blows air A to the balancing weight 65 coated on the rotating body 12 to spread the balancing weight 65 on the rotating body 12; a solidification step S05, which solidifies the balancing weight 65; and a second inspection step S08, which inspects the balance of the rotating body 12 formed with the balancing weight 65. In addition, in the following description, "operators, etc." include operators and assembly devices that perform various operations. Each operation may be performed only by the operator, only by the assembly device, or by the operator and the assembly device.

[0042] When the molding of the balancing weight 65 starts, the number of layers Nm of the molding layer molded on the rotating body 21 is 0 (S01). In addition, as described above, the number of layers Na of the balancing weight 65 in this embodiment is 1. In the first inspection step S02, the balance of the rotating body 12 is inspected. Although not shown in the figure, the operator or the like measures the offset of the center of gravity position of the rotating body 12 relative to the central axis J by a known balance measuring device. The balance measuring device can measure the offset by rotating the rotating body 12, or can measure the offset while the rotating body 12 is stationary. The operator or the like calculates the position of the molded balancing weight 65, that is, the molding position Pm, and the weight of the molded balancing weight 65, that is, the molding weight Wb, based on the offset. When the molding position Pm and the molding weight Wb are calculated, the first inspection step S02 ends. In addition, the molding position Pm and the molding weight Wb can also be calculated by the balance measuring device. In addition, in this embodiment, the molding position Pm is a part of the molding surface 61d. The molding position Pm may be a portion other than the molding surface 61 d of the impeller portion 60 , or may be a portion of the rotor 20 .

[0043] In the coating step S03, the melted balance weight 65 is coated on the rotating body 12. Figure 6 As shown, in the coating process S03, the operator or the like uses a coating device 91 disposed at a position on the side (+D1 side) closer to the first direction D1 than the impeller portion 60 to apply the heated and melted balancing weight 65 to the molding surface 61d. In the present embodiment, the balancing weight 65 contains a powder 65b, so the melted balancing weight 65 is in a paste state. In the present embodiment, the coating device 91 is a dispenser capable of ejecting a predetermined weight of the molten balancing weight 65. Therefore, the difference between the weight of the molten balancing weight 65 coated on the rotating body 12 and the molding weight Wb can be reduced. In addition, the coating device 91 is connected to the inside of a container having a heating unit such as a heater not shown. The balancing weight 65 melted by heating by the heating unit is stored inside the container. The molten balancing weight 65 inside the container is provided to the coating device 91. When the melted balance weight 65 of the molding weight Wb is applied to the molding position Pm of the molding surface 61d by the coating device 91, the coating step S03 is completed.

[0044] Since the molten balance weight 65 has a certain degree of viscosity, Figure 7 As shown, the shape of the balancing weight 65 applied to the molding surface 61d is roughly spherical. In addition, a protrusion 65c protruding to one side (+D1 side) of the first direction D1 is formed on the surface of the balancing weight 65. In this embodiment, the dimension L3 of the balancing weight 65 applied to the molding surface 61d in the first direction D1 is larger than the dimension L4 in the second direction D2. In addition, the dimension L3 of the balancing weight 65 applied to the molding surface 61d in the first direction D1 is larger than the dimension L4 in the first direction D1 of the groove portion 61c. In addition, the dimension L3 of the balancing weight 65 applied to the molding surface 61d in the first direction D1 may be smaller than the dimension L4 in the second direction D2, and the dimension L3 of the balancing weight 65 in the first direction D1 may be smaller than the dimension L4 in the second direction D2, and the dimension L3 of the balancing weight 65 in the first direction D1 may be smaller than the dimension L1 of the groove portion 61c in the first direction D1.

[0045] In the blowing process S04, air A is blown toward the balancing weight 65 coated on the rotating body 12, so that the balancing weight 65 is expanded on the rotating body 12. In the blowing process S04, the operator or the like blows air A toward the balancing weight 65 from one side of the first direction D1 through the blowing device 92 disposed at a position closer to the first direction D1 (+D1 side) than the impeller part 60. The air A is compressed air compressed by a compressor not shown. In addition, in the present embodiment, the temperature of the air A is a temperature higher than the melting point of the resin part 65a of the balancing weight 65. The temperature of the air A may be a temperature lower than the melting point of the resin part 65a of the balancing weight 65.

[0046] The melted balance weight 65 is expanded in the second direction D2 along the molding surface 61d by the wind pressure of the air A. In addition, the protrusion 65c enters the melted balance weight 65 by the wind pressure of the air A. As a result, the balance weight 65 becomes Figure 4 The mountain shape shown. In more detail, the dimension L1 of the balancing weight 65 in the first direction D1 is smaller than the dimension L2 in the second direction D2. In addition, the central portion of the balancing weight 65 in the second direction D2 protrudes to one side (+D1 side) of the first direction D1. In addition, the portion of the balancing weight 65 on one side in the first direction D1 is formed into a plane shape that is narrow in the second direction D2. In addition, the balancing weight 65 is formed into a curved surface shape whose hem extends along the second direction D2. In addition, the end portion of the balancing weight 65 on one side in the first direction D1 is located at a position closer to the other side (-D1 side) of the first direction D1 than the first outer side surface 61a. When the balancing weight 65 is extended on the rotating body 12, the blowing process S04 ends.

[0047] In the solidification step S05, the balancing weight 65 is solidified. In the solidification step S05, the operator solidifies the balancing weight 65 by cooling the melted balancing weight 65. The cooling of the balancing weight 65 may be performed in a room temperature atmosphere, or may be performed in a low temperature atmosphere by storing the rotating body 12 in a cooling furnace not shown in the figure. In addition, the solidification step S05 may also serve as the blowing step S04. When the balancing weight 65 is solidified, the solidification step S05 ends. In addition, in the present embodiment, the operator ends the solidification step S05 before the balancing weight 65 is completely solidified. In more detail, the operator solidifies the balancing weight 65 to the point where it can be maintained even if vibration is applied to the rotating body 12. Figure 4 When the balancing weight 65 has a hardness of the shape shown, the curing step S05 is terminated. Alternatively, the operator or the like may terminate the curing step S05 after the balancing weight 65 is completely cured.

[0048] like Figure 5 As shown, when the curing step S05 is completed, the number of layers Nm of the molded layers formed on the rotating body 21 becomes 1 (S06). In addition, as described above, since the number of layers Na of the molded balancing weight 65 is 1, the balancing weight 65 of the predetermined number of layers is formed on the rotating body 21. Therefore, the operator etc. performs the second inspection step S08 (S07).

[0049] In the second inspection step S08, the balance of the rotating body 12 on which the balancing weight 65 is formed is inspected. The operator measures the amount of deviation of the center of gravity of the rotating body 12 on which the balancing weight 65 is formed relative to the central axis J by using the above-mentioned balance measuring device (not shown) or the like. When the amount of deviation of the center of gravity of the rotating body 12 from the central axis J is less than a predetermined amount, that is, when the balance of the rotating body 12 is within the predetermined specification (S09), the operator ends the manufacture of the balancing weight 65. In addition, when the balance of the rotating body 12 is outside the predetermined specification (S09), the operator performs the second inspection step S08 after forming the balancing weight 65 of the forming weight Wb at the newly calculated forming position Pm (S03 to S06). The operator repeats the second inspection step S08 and the forming of the balancing weight 65 until the balance of the rotating body 12 is within the predetermined specification. When the balance of the rotating body 12 is within the predetermined specification, the operator ends the manufacture of the balancing weight 65 (S09).

[0050] The manufacturing method Mb of the balancing weight according to the present embodiment includes the following steps: a coating step S03 of coating the melted balancing weight 65 on the rotating body 12; a blowing step S04 of blowing air A to the balancing weight 65 coated on the rotating body 12 to spread the balancing weight 65 on the rotating body 12; and a solidification step S05 of solidifying the balancing weight 65. Therefore, when the balancing weight 65 is coated on the rotating body 12 in the coating step S03, the balancing weight 65 having a substantially spherical shape can be spread along the second direction D2 in the blowing step S04, so that the surface area of ​​the balancing weight 65 can be increased. As a result, the amount of heat dissipated from the surface of the balancing weight 65 to the atmosphere and the rotating body 12 in the solidification step S05 can be increased, so that the time for cooling the balancing weight 65 can be shortened. As a result, the time for solidification of the balancing weight 65 can be shortened, so that the increase in the manufacturing man-hours of the balancing weight 65 can be suppressed.

[0051] In addition, as described above, in the blowing step S04, the balancing weight 65 can be extended on the rotating body 12, so that the contact area between the balancing weight 65 and the rotating body 12 can be enlarged. As a result, the bonding strength between the balancing weight 65 and the rotating body 12 can be improved. Therefore, when the blower 10 is in operation, the balancing weight 65 can be prevented from being peeled off from the rotating body 12 due to the centrifugal force applied to the balancing weight 65 when the rotating body 12 rotates around the central axis J. Therefore, the rotational balance of the rotating body 12 can be appropriately stabilized, so that the rotating body 12 can be stably rotated around the central axis J. As a result, vibration and noise can be suppressed when the blower 10 is in operation. In addition, since the force applied to the rotor 20, that is, the rotor bearing 25 supporting the rotating body 12 can be suppressed from increasing, the deterioration of the rotor bearing 25 due to wear and the like can be suppressed.

[0052] In addition, in the present embodiment, since the air A is blown to the protrusion 65c formed on the surface of the balance weight 65 in the coating step S03 in the blowing step S04, the protrusion 65c can be inserted into the balance weight 65 as described above. Therefore, when the air blower 10 is operating, the protrusion 65c can be prevented from being separated from the balance weight 65, and thus, for example, the protrusion 65c between the rotor 20 and the stator 30 can be prevented from being bitten. Therefore, the stability of the operation of the air blower 10 can be improved.

[0053] In addition, when the balancing weight 65 is spread on the rotating body 12 by a scraper or other parts, a part of the paste-like balancing weight 65 is easily attached to the scraper or other parts, so it is difficult to stabilize the weight of the balancing weight 65 formed on the rotating body 12. In contrast, in the present embodiment, in the blowing step S04, the balancing weight 65 is spread on the rotating body 12 by air A, so that the weight of the balancing weight 65 can be appropriately stabilized. Therefore, the balance of the rotating body 12 can be adjusted with high precision, so that the rotating body 12 can be rotated more stably around the central axis J. Therefore, the vibration and noise when the blower 10 is in operation can be more appropriately suppressed, and the deterioration of the rotor bearing 25 can be more appropriately suppressed.

[0054] According to the present embodiment, the balancing weight 65 includes a metal powder 65b and a thermoplastic resin portion 65a containing the powder 65b. Therefore, compared with the case where the balancing weight 65 does not include the metal powder 65b, the specific gravity of the balancing weight 65 can be increased. As a result, the volume of the balancing weight 65 molded on the rotating body 12 can be reduced, so that the time for applying the balancing weight 65 to the rotating body 12 in the coating step S03 and the time for curing the balancing weight 65 in the curing step S05 can be suppressed from increasing. Therefore, the increase in the manufacturing man-hours of the balancing weight 65 can be suppressed.

[0055] In addition, in the present embodiment, as described above, the temperature of the air A is higher than the melting point of the resin portion 65a, and therefore, when the air A is blown toward the balancing weight 65 in the blowing step S04, it is possible to suppress the temperature of the resin portion 65a from decreasing and the viscosity of the resin portion 65a from increasing. Therefore, in the blowing step S04, the balancing weight 65 can be easily spread on the rotating body 12.

[0056] According to the present embodiment, the rotating body 12 is composed of the rotor 20 and the impeller part 60 of the blower 10. Therefore, the rotor 20 can be stably rotated around the central axis J, so that the radial position of the rotor 20 relative to the stator 30 can be suppressed from changing. Therefore, the magnetic force between the magnetic poles of the electromagnet formed by the stator 30 and the magnet 22 of the rotor 20 can be suppressed from changing, so the rotation speed and rotation torque of the rotor 20 and the impeller part 60 can be stabilized. As a result, the operation of the blower 10 can be stabilized.

[0057] According to the present embodiment, the balancing weight 65 is formed on the molding surface 61d on the side (+D1 side) facing the first direction D1 of the outer side surface of the rotating body 12, and the central part of the second direction D2 protrudes to the side of the first direction D1, and the dimension L1 of the first direction D1 is smaller than the dimension L2 of the second direction D2. Therefore, since it is easy to reduce the dimension of the balancing weight 65 in the first direction D1, that is, the dimension of the balancing weight 65 in the height direction, it is possible to suppress the increase of the air resistance applied to the balancing weight 65 when the rotating body 12 rotates. Therefore, the rotating body 12 can be stably rotated around the central axis J, and the driving efficiency of the blower 10 can be improved.

[0058] In addition, in the present embodiment, as described above, the dimension L1 of the balancing weight 65 in the first direction D1 is a mountain shape smaller than the dimension in the second direction D2, so that the surface area of ​​the balancing weight 65 can be increased. As a result, as described above, in the curing step S05, the curing time of the balancing weight 65 can be shortened. Therefore, the increase in the manufacturing man-hours of the balancing weight 65 can be suppressed. In addition, as described above, since the contact area between the balancing weight 65 and the rotating body 12 can be enlarged, the bonding strength between the balancing weight 65 and the rotating body 12 can be improved. Therefore, when the rotating body 12 rotates around the central axis J, the balancing weight 65 can be suppressed from peeling off from the rotating body 12.

[0059] According to the present embodiment, the portion of the balancing weight 65 on one side (+D1 side) of the first direction D1 is a plane shape narrow in the second direction D2, and the balancing weight 65 is a curved surface shape that is extended downward. Therefore, compared with the case where the balancing weight 65 has a protrusion 65c protruding to one side of the first direction D1, the air resistance applied to the balancing weight 65 when the rotating body 12 rotates can be more appropriately reduced. Therefore, the rotating body 12 can be rotated more stably around the central axis J, and the driving efficiency of the blower 10 can be more appropriately improved.

[0060] According to the present embodiment, the rotating body 12 has a first outer side surface 61a facing one side (+D1 side) of the first direction D1 and a groove portion 61c recessed from the first outer side surface 61a to the other side (-D1 side) of the first direction D1, and the molding surface 61d is a surface of the inner side surface of the groove portion 61c facing one side of the first direction D1, and the surface of the balancing weight 65 facing one side of the first direction D1 is arranged at a distance from the first outer side surface 61a. Therefore, the balancing weight 65 is easily arranged inside the groove portion 61c, so that the air resistance applied to the balancing weight 65 when the rotating body 12 rotates can be more appropriately reduced. Therefore, the rotating body 12 can be more appropriately rotated around the central axis J stably, and the driving efficiency of the blower 10 can be more appropriately improved.

[0061] According to the present embodiment, the groove portion 61c extends over the entire circumference. When the balancing weight 65 is applied to the inside of the groove portion 61c by a scraper or the like, ribs are sometimes provided inside the groove portion 61c in order to scrape the balancing weight 65 from the scraper or the like. In contrast, in the present embodiment, as described above, the balancing weight 65 is applied to the molding surface 61d by the coating device 91. Therefore, even in a structure in which the groove portion 61c extends over the entire circumference, that is, a structure in which no ribs are provided on the groove portion 61c, the balancing weight 65 can be easily applied to the molding surface 61d. Therefore, in the present embodiment, the shape of the groove portion 61c can be simplified, and thus the structure of the mold used when molding the impeller portion 60 can be simplified. Therefore, the increase in the manufacturing cost of the mold can be suppressed.

[0062] According to the present embodiment, the blower 10 includes a balancing weight 65, a rotor 20 that can rotate about a central axis J, and an impeller 60 that is connected to the rotor 20 and can rotate about the central axis J, and the rotating body 12 is composed of the rotor 20 and the impeller 60. Therefore, as described above, since the surface area of ​​the balancing weight 65 can be increased in the blowing step S04, the time for curing the balancing weight 65 can be shortened in the curing step S05. Therefore, the increase in the manufacturing man-hours of the balancing weight 65 can be suppressed, and thus the increase in the manufacturing man-hours of the blower 10 can be suppressed.

[0063] <Second embodiment>

[0064] like Figure 8 As shown, the balancing weight 265 included in the blower 210 of this embodiment is composed of a plurality of molded layers 266 and 267 stacked on the rotating body 12. In the following description, the same reference numerals are used to denote the same components as those of the first embodiment, and description thereof will be omitted.

[0065] The balancing weight 265 is in the shape of a mountain that protrudes from the molding surface 61d to one side (+D1 side) in the first direction D1. In more detail, the dimension L1 of the balancing weight 265 in the first direction D1 is smaller than the dimension L2 in the second direction D2. In addition, the central portion of the balancing weight 265 in the second direction D2 protrudes to one side in the first direction D1. In addition, the portion of the balancing weight 265 on one side in the first direction D1 is in the shape of a narrow plane in the second direction D2. The balancing weight 265 is in the shape of a curved surface whose hem extends along the second direction D2. Although not shown in the figure, the surface of the balancing weight 265 on the side facing the first direction D1 is arranged at a distance from the first outer side surface 61a. The balancing weight 265 of this embodiment is composed of two molding layers 266 and 267. The number of layers Na of the balancing weight 265 of this embodiment is 2. The balancing weight 265 can be composed of three or more molding layers. The balancing weight 265 of this embodiment is composed of a first molding layer 266 and a second molding layer 267.

[0066] The first molded layer 266 is molded on the molded surface 61d. The first molded layer 266 is in a mountain shape protruding from the molded surface 61d to one side (+D1 side) in the first direction D1. The second molded layer 267 is formed on the first molded layer 266. The second molded layer 267 is in a mountain shape protruding from the first molded layer 266 to one side in the first direction D1. The second molded layer 267 is connected to the first molded layer 266 in the first direction D1.

[0067] Next, the manufacturing method Mb of the balancing weight 265 of this embodiment is described. In this embodiment, the coating step S03, the blowing step S04 and the curing step S05 are respectively performed according to the plurality of molding layers 266 and 267. Thus, the second molding layer 267 is molded on the cured first molding layer 266. In the following description, the description of the same operations as those of the first embodiment is sometimes omitted. Figure 5 As shown, when the molding of the balance weight 265 starts, the number of layers Nm molded on the rotating body 21 is 0 (S01). In addition, as described above, in this embodiment, the number of layers Na of the molded balance weight 265 is 2.

[0068] In the first inspection process S02, the operator calculates the position of the molded balancing weight 265 in the rotating body 12, that is, the molding position Pm, and the weight of the molded balancing weight 265, that is, the molding weight Wb. Then, the operator molds the first molded layer 266 on the molding surface 61d. First, in the coating process S03, the operator coats the heated and melted balancing weight on the molding surface 61d through the coating device 91. At this time, the first weight Wb1, which is the weight of the balancing weight coated on the molding surface 61d, is less than the molding weight Wb. The first weight Wb1 is the weight of the first molded layer 266. Next, in the blowing process S04, the operator blows air A to the melted balancing weight through the blowing device 92, so that the melted balancing weight expands in the second direction D2 along the molding surface 61d. Thus, the first molded layer 266 is formed. Figure 8 Next, in the curing step S05 , the operator or the like forms the first molded layer 266 on the rotating body 12 while curing the first molded layer 266 by cooling it.

[0069] When the curing step S05 is completed, the number of layers Nm formed on the rotating body 21 becomes 1 (S06). In addition, as described above, since the number of layers Na of the molded balance weight 65 is 2, the operator then molds the second molded layer 267 on the first molded layer 266 (S07).

[0070] First, in the coating process S03, the operator or the like coats the heated and melted balancing weight on the solidified first molded layer 266. At this time, the second weight Wb2, which is the weight of the balancing weight coated on the first molded layer 266, is the weight of the difference between the molding weight Wb and the first weight Wb1. The second weight Wb2 is the weight of the second molded layer 267. Next, in the blowing process S04, the operator or the like blows air A toward the melted balancing weight through the blowing device 92, so that the melted balancing weight spreads in the second direction D2 along the surface of the first molded layer 266. Thus, the second molded layer 267 is formed. Figure 8 Next, in the curing step S05, the operator cools the second molded layer 267 to cure it. Thus, the second molded layer 267 is molded on the first molded layer 266, and the balancing weight 265 is molded on the rotating body 12. Figure 5 As shown, when the curing step S05 is completed, the number of layers Nm of the molded layer formed on the rotating body 21 becomes 2 (S06). In addition, as described above, since the number of layers Na of the molded balancing weight 265 is 2, the balancing weight 65 of the predetermined number of layers is formed on the rotating body 21. Therefore, the operator etc. performs the second inspection step S08 (S07).

[0071] In the second inspection step S08, the operator etc. inspects the balance of the rotating body 12 formed with the balancing weight 265. When the balance of the rotating body 12 is within the prescribed specifications (S09), the operator etc. completes the manufacture of the balancing weight 265. In addition, when the balance of the rotating body 12 is outside the prescribed specifications (S09), the operator etc. performs the second inspection step S08 after forming the balancing weight Wb at the newly calculated forming position Pm (S03 to S05). The operator etc. repeats the second inspection step S08 and the forming of the balancing weight 265 until the balance of the rotating body 12 is within the prescribed specifications. When the balance of the rotating body 12 is within the prescribed specifications, the operator etc. completes the manufacture of the balancing weight 265.

[0072] In addition, when the molding weight Wb of the balancing weight 265 calculated in the first inspection step S02 exceeds the weight that can be molded at one time, the molding of the balancing weight 265 can be performed without performing the second inspection step S08. In addition, when the balancing weight 265 is composed of three or more molding layers, the number of layers Na of the molded balancing weight 265 is set to the number of layers of the balancing weight 265, and the coating step S03, the blowing step S04, and the curing step S05 are performed for each molding layer. In this way, the balancing weight 265 with three or more molding layers stacked can be molded on the rotating body 12.

[0073] According to the present embodiment, the balancing weight 265 is composed of a plurality of molded layers 266 and 267 stacked on the rotating body 12, and the coating step S03, the blowing step S04, and the curing step S05 are performed for each molded layer 266 and 267, thereby forming the molded layer 267 on the solidified molded layer 266. In the case where the balancing weight 265 with a heavy weight is molded on the rotating body 12 by a single coating, the time for blowing the air A to the melted balancing weight 265 to expand the balancing weight 265 in the second direction D2 and the time for curing the balancing weight 265 are likely to increase. Therefore, the operation man-hours of the blowing step S04 and the operation man-hours of the curing step S05 are likely to increase. In contrast, in the present embodiment, after the first molded layer 266 is molded on the rotating body 12, the second molded layer 267 is molded on the first molded layer 266, so that the first weight Wb1 of the first molded layer 266 and the second weight Wb2 of the second molded layer 267 can be suppressed from increasing. Thus, when the first molded layer 266 and the second molded layer 267 are molded separately, the increase in the working hours of the blowing step S04 and the working hours of the curing step S05 can be suppressed. Therefore, even when molding a heavy balancing weight 265, the increase in the manufacturing hours of the balancing weight 265 can be suppressed.

[0074] According to the present embodiment, the balancing weight 265 is composed of a plurality of molded layers 266 and 267 stacked on the rotating body 12. Therefore, as described above, when the first molded layer 266 and the second molded layer 267 are molded separately, it is possible to suppress an increase in the number of man-hours for the blowing step S04 and the number of man-hours for the curing step S05. Therefore, even when molding a heavy balancing weight 265, it is possible to suppress an increase in the number of man-hours for manufacturing the balancing weight 265.

[0075] An embodiment of the present invention has been described above, but the various structures and their combinations in the embodiment are examples, and the addition, omission, replacement and other changes of the structure can be made without departing from the scope of the present invention. In addition, the present invention is not limited to the embodiment. For example, the use of the balancing weight, motor and blower shown in the above embodiment is not particularly limited.

[0076] The blower may be, for example, a centrifugal fan that blows air radially outward. In this case, by forming a balancing weight on the rotating body, the deviation of the center of gravity of the rotating body relative to the central axis can be reduced, so that the rotating body can be stably rotated around the central axis J.

[0077] The manufacturing method of the balancing weight is not limited to the present embodiment. For example, the blowing process and the curing process may be performed simultaneously. In this case, by setting the temperature of the air to a temperature lower than the melting point of the resin portion, the balancing weight can be cooled and solidified while the balancing weight is extended on the molding surface. Therefore, the increase in the manufacturing man-hours of the balancing weight can be more appropriately suppressed.

[0078] In addition, the present technology can adopt the following structures.

[0079] (1) A method for manufacturing a balancing weight, wherein a balancing weight for adjusting the balance of the rotating body is molded on a rotating body, wherein the method for manufacturing the balancing weight comprises the following steps: a coating step of coating the molten balancing weight on the rotating body; a blowing step of blowing air to the balancing weight coated on the rotating body so that the balancing weight spreads on the rotating body; and a curing step of curing the balancing weight.

[0080] (2) The method for manufacturing a balance weight according to (1), wherein the balance weight includes: a powder made of metal; and a resin part having thermoplasticity and containing the powder.

[0081] (3) A method for manufacturing a balancing weight according to (1) or (2), wherein the balancing weight is composed of a plurality of molded layers stacked on the rotating body, and a molded layer is molded on the cured molded layer by performing the coating process, the blowing process and the curing process on each molded layer.

[0082] (4) The method for manufacturing a balance weight according to any one of (1) to (3), wherein the rotating body is composed of a rotor and an impeller portion of a blower fan.

[0083] (5) A balancing weight for adjusting the balance of a rotating body that can rotate around a central axis, wherein the balancing weight is molded on a molded surface on the side facing a first direction among the outer side surfaces of the rotating body, a central portion of the balancing weight in a second direction which is a direction perpendicular to the first direction protrudes toward one side of the first direction, and a dimension of the balancing weight in the first direction is smaller than a dimension in the second direction.

[0084] (6) The balance weight according to (5), wherein a portion of the balance weight on one side in the first direction is in a planar shape that is narrow in the second direction, and the balance weight is in a curved surface shape that expands downward.

[0085] (7) The balance weight according to (5) or (6), wherein the balance weight is composed of a plurality of molded layers stacked on the rotating body.

[0086] (8) A balancing weight according to any one of (5) to (7), wherein the rotating body has a first outer side surface facing one side of the first direction and a groove portion recessed from the first outer side surface to the other side of the first direction, the molding surface is a surface of the inner side surface of the groove portion facing the first direction, and the surface of the balancing weight facing the first direction is arranged at a distance from the first outer side surface.

[0087] (9) The balance weight according to (8), wherein the groove portion extends along the entire circumference.

[0088] (10) A blower comprising: a balancing weight as described in any one of (5) to (9); a rotor capable of rotating about a central axis; and an impeller portion connected to the rotor and capable of rotating about the central axis, wherein the rotating body is composed of the rotor and the impeller portion.

Claims

1. A method for manufacturing a balancing weight, wherein a balancing weight for adjusting the balance of the rotating body is formed on a rotating body, wherein: The manufacturing method of the balancing weight comprises the following steps: A coating step of coating the molten balance weight on the rotating body; a blowing step of blowing air toward the balancing weight applied to the rotating body so that the balancing weight is spread on the rotating body; as well as The curing step is to cure the balancing weight.

2. The method for manufacturing a balancing weight according to claim 1, wherein: The balancing weight comprises: a powder made of metal; and The resin part has thermoplasticity and contains the powder.

3. The method for manufacturing a balancing weight according to claim 1, wherein: The balancing weight is composed of a plurality of molded layers stacked on the rotating body. By performing the coating step, the blowing step, and the curing step for each molding layer, a molding layer is molded on the cured molding layer.

4. The method for manufacturing a balancing weight according to any one of claims 1 to 3, wherein: The rotating body is composed of a rotor and an impeller portion included in the air-sending fan.

5. A balancing weight for adjusting the balance of a rotating body that can rotate about a central axis, wherein: The balancing weight is formed on a molding surface on one side of the outer side surface of the rotating body facing the first direction. The center portion of the balance weight in a second direction, which is a direction perpendicular to the first direction, protrudes toward one side in the first direction. The dimension of the balance weight in the first direction is smaller than the dimension of the second direction.

6. The balancing weight according to claim 5, wherein: A portion of the balance weight on one side in the first direction is in a planar shape that is narrow in the second direction, and the balance weight is in a curved surface shape that expands downward.

7. The balancing weight according to claim 5, wherein: The balance weight is composed of a plurality of molded layers stacked on the rotating body.

8. The balancing weight according to claim 5, wherein: The rotating body has a first outer side surface facing one side of the first direction and a groove portion recessed from the first outer side surface toward the other side of the first direction. The molding surface is a surface of the inner side surface of the groove portion that faces the first direction. A surface of the balance weight that faces one side in the first direction is disposed at a distance from the first outer side surface.

9. The balancing weight according to claim 8, wherein: The groove portion extends along the circumferential direction over the entire circumference.

10. A blower, comprising: The balancing weight according to any one of claims 5 to 9; a rotor rotatable about a central axis; and The impeller part is connected to the rotor and can rotate around the central axis. The rotating body is composed of the rotor and the impeller part.

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