Fan control system, fan system, active ingredient generation system, fan control method, and program

Abstract

A fan control system according to the present disclosure includes a control unit that selects a control mode from among a plurality of control modes including a first mode and a second mode. The first mode is a control mode in which an electric signal is supplied to a fan motor to cause the fan motor to operate at a first rotational speed. The second mode is a control mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a second rotational speed that is lower than the first rotational speed. The control unit has a function of selecting the second mode during a period after the fan motor is started and before the first mode is selected.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to a fan control system, a fan system, an active ingredient generation system, a fan control method, and a program. More specifically, the present disclosure relates to a fan control system, a fan system, an active ingredient generation system, a fan control method, and a program that control a fan motor having an impregnated bearing in which a lubricant is impregnated. BACKGROUND

[0002] In Patent Literature 1, there is described a fan motor (DC brushless motor fan) that has an impregnated bearing (porous bearing) and a shaft that is inserted through the impregnated bearing and is held by the impregnated bearing in a rotatable manner. The fan motor also has a rotor that is fixed to the shaft and has a permanent magnet and a blade (fin). In this fan motor, the impregnated bearing is shaped by sintering metal powder and has voids (pores) for impregnating (soaking) a lubricant (lubricating oil).

[0003] In this fan motor, the lubricant impregnated in the impregnated bearing achieves lubrication between the impregnated bearing and the shaft.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2013-63009 SUMMARY

[0007] In the above-described fan motor, in a case where the impregnation amount of the lubricant in the impregnated bearing is lower than an appropriate amount, for example, there is a possibility that a problem such as an abnormal noise due to shrinkage of the lubricant occurs in a special environment such as a low-temperature environment.

[0008] The present disclosure was achieved in view of the above-described circumstances, and aims to provide a fan control system, a fan system, an active ingredient generation system, a fan control method, and a program that are less likely to cause a problem such as an abnormal noise even in a special environment.

[0009] A fan control system according to an embodiment of the present disclosure is a fan control system that controls a fan motor. The fan motor has a rotor including a blade, a stator, and an impregnated bearing in which a lubricant is impregnated, and the fan motor holds the rotor in a rotatable manner by the impregnated bearing. The fan control system includes a control unit that selects a control mode from among a plurality of control modes including a first mode and a second mode. The first mode is a control mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a first rotational speed. The second mode is a control mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a second rotational speed that is lower than the first rotational speed. The control unit has a function of selecting the second mode during a period after the fan motor is started and before the first mode is selected.

[0010] A fan system according to an embodiment of the present disclosure includes the fan control system and the fan motor.

[0011] An active ingredient generation system according to an embodiment of the present disclosure includes the fan system and a discharge unit that generates an active ingredient. The fan motor generates an airflow for discharging the active ingredient.

[0012] A fan control method according to an embodiment of the present disclosure is a fan control method that controls a fan motor, and a control mode can be selected from among a plurality of control modes including a first mode and a second mode. The fan motor has a rotor including a blade, a stator, and an impregnated bearing in which a lubricant is impregnated, and the fan motor holds the rotor in a rotatable manner by the impregnated bearing. The first mode is a control mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a first rotational speed. The second mode is a control mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a second rotational speed that is lower than the first rotational speed. The fan control method has a process of selecting the second mode during a period after the fan motor is started and before the first mode is selected.

[0013] A program according to an embodiment of the present disclosure is a program for causing one or more processors to execute the fan control method.

[0014] According to the present disclosure, there are advantages in that it is difficult to generate abnormal noise and the like even in a special environment. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a schematic block diagram of an active ingredient generation system including the fan control system according to Embodiment 1.

[0016] Figure 2Ais a schematic sectional view of an impregnated bearing of the fan motor described above.

[0017] Figure 2B is a schematic sectional view of an impregnated bearing of the fan motor described above.

[0018] Figure 2C is a schematic sectional view of an impregnated bearing of the fan motor described above.

[0019] Figure 3 is a graph showing an electric signal supplied from the fan control system described above to the fan motor.

[0020] Figure 4A is a perspective view of the active ingredient generating system described above.

[0021] Figure 4B is a perspective view of the active ingredient generating system described above, viewed from another direction.

[0022] Figure 5 is an exploded perspective view of the active ingredient generating system described above.

[0023] Figure 6A is an exploded perspective view showing a housing and internal components of the active ingredient generating system described above.

[0024] Figure 6B is a schematic perspective view in which a region Z1 of Figure 6A is enlarged.

[0025] Figure 7 is a flowchart showing an operation of the fan control system described above.

[0026] Figure 8A is a graph showing an electric signal supplied from the fan control system related to the modification of Embodiment 1 to the fan motor.

[0027] Figure 8B is a graph showing an electric signal supplied from the fan control system related to the modification of Embodiment 1 to the fan motor.

[0028] Figure 9 is a graph showing an electric signal supplied from the fan control system related to Embodiment 2 to the fan motor.

[0029] Figure 10 is a graph showing an electric signal supplied from the fan control system related to the modification of Embodiment 2 to the fan motor. DETAILED DESCRIPTION

[0030] (Embodiment 1)

[0031] (1) Schematic

[0032] Next, a summary of the fan control system 10, the fan system 100, and the active ingredient generation system 1 according to the present embodiment will be described with reference to Figures 1-3

[0033] The active ingredient generation system 1 according to the present embodiment includes the discharge section 21, and generates active ingredients by the discharge section 21. In the present embodiment, the discharge section 21 has a discharge electrode 211 (see Figure 6B ) and an opposing electrode 212 (see Figure 6B ), and generates discharge by applying a voltage between the discharge electrode 211 and the opposing electrode 212. The "active ingredient" in the present disclosure is a component generated by discharge in the discharge section 21, and refers to, for example, a charged fine particle liquid containing OH radicals, OH radicals, O2 radicals, negative ions, positive ions, ozone, or nitrate ions. These active ingredients are not limited to sterilization, deodorization, moisturization, freshness preservation, or inactivation of viruses, but also become the basis for useful effects in various scenarios.

[0034] The active ingredient generation system 1 according to the present embodiment includes, in addition to the internal components 2 including the discharge section 21 (see Figure 5 ), a housing 3 (see Figure 5 ). The housing 3 constitutes the outer shape of the active ingredient generation system 1, and by housing the internal components 2 in the housing 3, a unitized active ingredient generation system 1 is constituted. In the housing 3, a discharge port 31 (see Figure 5 ) for discharging active ingredients and an air supply port 32 (see Figure 5 ) for introducing air into the housing 3 are formed. Furthermore, in the present embodiment, the internal components 2 also include a fan motor 22 (see Figure 5 ). The fan motor 22 functions as an air supply section that generates an air current (wind) that flows from the air supply port 32 toward the discharge port 31. As a result, air introduced into the housing 3 from the air supply port 32 is discharged to the outside of the housing 3 from the discharge port 31. The active ingredients generated by the discharge section 21 are discharged to the outside of the housing 3 from the discharge port 31 along with the air current generated by the fan motor 22 as the air supply section.

[0035] In addition, in the present embodiment, as shown in Figure 2A , the fan motor 22 has a rotor 101, a stator 102, and an impregnated bearing 103. The rotor 101 includes a blade 104. The impregnated bearing 103 is impregnated with a lubricant 105 (see Figure 2B and Figure 2C ​). As an example, the impregnated bearing 103 is formed by sintering metal powder, and has voids (pores) for impregnating the lubricant 105. The fan motor 22 holds the rotor 101 in a rotatable manner by the impregnated bearing 103. In this configuration, the lubricant 105 impregnated in the impregnated bearing 103 achieves lubrication between the impregnated bearing 103 and the rotor 101.

[0036] The fan control system 10 according to the present embodiment is a system that controls the fan motor 22 having the impregnated bearing 103 as described above as a control target. That is, the fan control system 10 has the rotor 101 including the blade 104, the stator 102, and the impregnated bearing 103 in which the lubricant 105 is impregnated, and controls the fan motor 22 that holds the rotor 101 in a rotatable manner by the impregnated bearing 103. The fan control system 10 includes the control section 11 that selects a control mode from among a plurality of control modes including a first mode and a second mode. The first mode is a control mode in which an electric signal (in the example of FIG. 1, a first voltage V1) is supplied to the fan motor 22 to cause the fan motor 22 to operate at a first rotational speed. The second mode is a control mode in which an electric signal (in the example of FIG. 1, a second voltage V2) is supplied to the fan motor 22 to cause the fan motor 22 to operate at a second rotational speed that is lower than the first rotational speed. The control section 11 has a function (hereinafter referred to as an "idling function") of selecting the second mode during a period (in the example of FIG. 1, a period T2) after the fan motor 22 is started and before the first mode is selected. Figure 3 Figure 3 Figure 3

[0037] According to this configuration, the second mode is selected during a period after the fan motor 22 is started and before the first mode is selected by the idling function of the control section 11. Therefore, the fan motor 22 operates at the second rotational speed that is lower than the first rotational speed before the fan motor 22 operates at the first rotational speed. Thus, even in a special environment such as a low-temperature environment, the impregnated bearing 103 is heated during the period in which the fan motor 22 operates at the second rotational speed, and thus it is difficult to cause a problem such as an abnormal noise due to shrinkage of the lubricant 105.

[0038] In addition, the fan control system 10 according to the present embodiment constitutes a fan system 100 together with the fan motor 22. In other words, the fan system 100 according to the present embodiment includes the fan control system 10 and the fan motor 22. The fan control system 10 controls the fan motor 22 by supplying an electric signal to the fan motor 22. That is, the fan motor 22 operates in response to the electric signal from the fan control system 10.

[0039] ​​​In addition, the fan system 100 according to the present embodiment constitutes an active ingredient generation system 1 together with the active ingredient generation portion 21. In other words, the active ingredient generation system 1 according to the present embodiment is provided with the fan system 100 and the active ingredient generation portion 21. The active ingredient generation portion 21 generates an active ingredient. The fan motor 22 generates an airflow for discharging the active ingredient. That is, in the active ingredient generation system 1, the active ingredient generated by the active ingredient generation portion 21 can be efficiently discharged to the outside of the housing 3 along the airflow generated by the fan motor 22 as the air supply portion.

[0040] (2) Details

[0041] Hereinafter, details of the fan control system 10, the fan system 100, and the active ingredient generation system 1 according to the present embodiment will be described with reference to Figures 1-7

[0042] (2.1) Definitions

[0043] The "impregnation" in the present disclosure refers to a state in which, for example, a fluid in a liquid or gel state is impregnated into an object having a porous structure or a fibrous structure with a large number of gaps (voids) so that the fluid in a liquid or gel state is held in the gaps of the object. That is, as an example, the impregnated bearing 103 for impregnating the lubricant 105 is a porous structure formed by sintering metal powder and having a large number of gaps for impregnating the lubricant 105. The lubricant 105 in a liquid or gel state can be impregnated into such an impregnated bearing 103 so as to be in a state in which the lubricant 105 is held in the large number of gaps of the impregnated bearing 103. This state is referred to as a state in which the impregnated bearing 103 is impregnated with the lubricant 105.

[0044] In addition, the "gel state" in the present disclosure refers to a state having properties between a liquid and a solid, including a state of a colloid composed of two phases of a liquid phase and a solid phase. For example, a state of an emulsion in which a dispersion medium is a liquid phase and a dispersed phase is a liquid phase, a suspension in which a dispersion medium is a liquid phase and a dispersed phase is a solid phase, and the like, which is referred to as a gel or a sol, is included in the "gel state". In addition, a state in which a dispersion medium is a solid phase and a dispersed phase is a liquid phase is also included in the "gel state". That is, the lubricant 105 impregnated in the impregnated bearing 103 is an object having properties as a fluid in which a volume is constant if temperature and pressure are constant and which does not have a definite shape. In other words, the lubricant 105 impregnated in the impregnated bearing 103 is a fluid (flowing body) other than a gas. The "fluid" referred to here includes both Newtonian fluid and non-Newtonian fluid. In the present embodiment, as an example, a lubricant 105 in a liquid state composed of a synthetic oil or a mineral oil or the like is impregnated in the impregnated bearing 103.​

[0045] The term "electrical signal" as used in this disclosure refers to all signals that transmit information electrically. This includes not only signals that transmit information by changing the amplitude, frequency, or phase of a carrier wave (modulation), but also signals that transmit information based on the magnitude of voltage or current. Furthermore, electrical signals include both digital and analog signals. In this embodiment, as an example, the electrical signal used by the fan control system 10 to control the fan motor 22 is a DC voltage applied to the fan motor 22. That is, the electrical signal composed of the DC voltage applied to the fan motor 22 can transmit information based on the magnitude of the voltage, and the fan motor 22 can be controlled by changing the magnitude of this voltage.

[0046] Furthermore, the term "integrated" as used in this disclosure refers to a method in which multiple elements (parts) can be physically treated as a single unit. In other words, multiple elements integrated means that multiple elements can be combined into one and treated as a single component. In this case, the multiple elements can be inseparable, like a single molded article, or they can be mechanically coupled, for example, through riveting, bonding, welding, or threading. As an example, the upstream and downstream blocks included in the airflow component 5 described later can be integrated in an appropriate manner.

[0047] Below, as an example, we define three mutually orthogonal axes: the X-axis, the Y-axis, and the Z-axis. In particular, we define the axis along the long side of the housing 3 as the "X-axis," and the axis along the junction of the housing 3 and the cover 4 (see reference). Figure 4A The axis of the combined directions is designated as the "Z-axis". The "Y-axis" is an axis orthogonal to either the X-axis or the Z-axis and along the short side of the housing 3. Furthermore, the direction in which the active ingredient is discharged from the outlet 31 is defined as the positive direction of the X-axis, and the positive direction of the housing 3 as viewed from the cover 4 is defined as the positive direction of the Z-axis. Additionally, the view viewed from the positive direction of the Z-axis is referred to below as a "top view". The X-axis, Y-axis, and Z-axis are all imaginary axes; the arrows indicating "X", "Y", and "Z" in the accompanying drawings are merely illustrative and do not represent actual objects. Furthermore, these directions are not intended to define the orientation of the active ingredient generation system 1 during use.

[0048] Below, as an example, we assume that the active ingredient generation system 1 is used in a vehicle. That is, the active ingredient generation system 1 is used, for example, in the following manner: it is disposed inside the dashboard or the like, discharges the active ingredient into the duct of the vehicle's air conditioning equipment, and discharges the active ingredient into the vehicle through the air outlet of the air conditioning equipment.

[0049] (2.2) Overall Structure

[0050] First, refer toFigure 1 , Figures 4A-6B The overall structure of the effective ingredient generation system 1 involved in this embodiment will be described.

[0051] like Figure 1 As shown, the active ingredient generating system 1 according to this embodiment includes a fan system 100 and a discharge unit 21 for generating active ingredients. The fan system 100 includes a fan control system 10 and a fan motor 22. The fan motor 22 included in the fan system 100 functions as an air supply unit in the active ingredient generating system 1 to generate airflow for discharging active ingredients.

[0052] Furthermore, as described above, the active ingredient generating system 1 according to this embodiment, in addition to the internal component 2 including the discharge section 21, also includes a housing 3. The housing 3 is formed in the shape of a box with a discharge port 31 for discharging the active ingredient. In addition to the internal component 2 and the housing 3, the active ingredient generating system 1 according to this embodiment also includes a cover 4 and a buffer body 41 (see reference 1). Figure 5 ) and air duct components 5.

[0053] The cover 4 is joined to the housing 3. The housing 3 has an opening 33 that is separate from the outlet 31 (see reference). Figure 5 The cover 4 is engaged with the housing 3 in a manner that blocks the opening 33, with the internal component 2 housed between the cover 4 and the housing 3. That is, the housing 3 is formed as a box with one surface (orthogonal to the Z-axis) as the opening 33. The cover 4 blocks the opening 33 by engaging with the housing 3, thus forming the outline of the effective ingredient generation system 1 together with the housing 3. The internal component 2 is housed within the internal space of the housing 3, which is surrounded by the housing 3 and the cover 4. Therefore, when the internal component 2 is assembled into the housing 3 from the opening 33, it is covered by the cover 4 to prevent the internal component 2 from being exposed from the opening 33.

[0054] In this embodiment, the housing 3 has a base plate 35, a peripheral wall 36, and a flange 37. The peripheral wall 36 protrudes from the outer periphery of the base plate 35 in the negative direction of the Z-axis. Furthermore, the surface of the base plate 35 facing the negative direction of the Z-axis, that is, the surface surrounded by the peripheral wall 36, becomes the bottom surface 310 of the housing 3 (see reference). Figure 6A The flange 37 extends outward from the front end of the peripheral wall 36. The housing 3 is engaged with the cover 4 via the flange 37.

[0055] In this embodiment, the housing 3 has a metal body 30. The metal body 30 surrounds at least the discharge portion 21 in the internal component 2. The metal body 30 has a seamless portion 301 at the corner between two adjacent faces facing different directions.

[0056] The "seamless portion" in the present disclosure refers to a portion that connects two adjacent faces without a seam between the two adjacent faces at a corner portion facing in different directions. That is, the seamless portion 301 connects two adjacent faces without a seam by filling at least a portion of a gap between the two adjacent faces at a corner portion, thereby making the two adjacent faces continuous without a seam. The seamless portion 301 is a structure that reduces the gap in at least a portion of the gap between the two adjacent faces by filling the gap, and includes both a structure that completely fills the gap and a structure that fills only a portion of the gap. That is, the seamless portion 301 is a structure that plugs at least a portion of the gap between the two adjacent faces at a corner portion of the metal body 30 in a manner that reduces the gap. Therefore, in the active ingredient generation system 1 according to the present embodiment, although the seamless portion 301 is provided, a small gap or a hole can be present at a corner portion between two adjacent faces facing in different directions in the metal body 30.

[0057] Here, the housing 3 is formed by performing drawing processing (square tube drawing processing) on a metal plate. In the thus-formed housing 3, the corner portion between the bottom plate 35 and the peripheral wall 36, needless to say, and the four corner portions located at the four corners in plan view in the peripheral wall 36 are also free from a seam. In other words, in the present embodiment, the gap at the corner portion between two adjacent faces facing in different directions in at least the peripheral wall 36 is completely filled with the seamless portion 301. Therefore, the peripheral wall 36 of the housing 3 that surrounds the bottom surface 310 is formed of one metal plate that is continuous without a seam in the circumferential direction of the bottom surface 310.

[0058] According to the active ingredient generation system 1 according to the present embodiment, at least the discharge portion 21 is surrounded by the metal body 30 of the housing 3, and thus the metal body 30 functions as a shield against electromagnetic noise generated when discharging in the discharge portion 21. Moreover, the metal body 30 is a seamless structure having the seamless portion 301 at a corner portion between two adjacent faces facing in different directions. The electromagnetic noise leaking from the gap at the corner portion between the two adjacent faces can be reduced by the seamless portion 301.

[0059] In the present embodiment, the housing 3 is formed of a metal plate having electrical conductivity. Therefore, the housing 3 as a whole is a metal body 30 made of metal. Also, the cover body 4 is formed of a metal plate having electrical conductivity, like the housing 3. Therefore, the cover body 4 as a whole is made of metal. Thus, the internal component 2 is housed in a space surrounded by the metal members (the housing 3 and the cover body 4) made of metal. The internal component 2 is fixed to the housing 3 in the housing 3. The circuit board 230 of the internal component 2 is fixed to the fixing portion 61 by a screw 71 and a nut 72, and thus the internal component 2 is fixed to the bottom surface 310 of the housing 3. That is, the housing 3 has the fixing portion 61 that fixes the circuit board 230 to the bottom surface 310 of the housing 3.

[0060] Further, the housing 3 has a support portion 62. The support portion 62 has a function of supporting the circuit board 230 included in the internal member 2. In the present embodiment, a pair of support portions 62 is provided on a pair of inner sides of the peripheral wall 36 facing each other in the Y-axis direction. The pair of support portions 62 protrude from the portions facing each other in the pair of inner sides in a direction in which they approach each other.

[0061] Further, the housing 3 has a restriction portion 63. The restriction portion 63 is located between the bottom surface 310 of the housing 3 and the circuit board 230. The restriction portion 63 has a function of restricting movement of the circuit board 230 in a direction in which it approaches the bottom surface 310. In the present embodiment, a pair of restriction portions 63 is provided on a pair of inner sides of the peripheral wall 36 facing each other in the Y-axis direction. The pair of restriction portions 63 protrude from the portions facing each other in the pair of inner sides in a direction in which they approach each other.

[0062] The cover 4 is formed in a rectangular shape in plan view (viewed from the positive direction of the Z-axis) with the X-axis direction as the long side direction and the Y-axis direction as the short side direction. The cover 4 has a first plug piece 42 that plugs a portion of the discharge port 31 of the housing 3, and a second plug piece 43 that plugs a portion of the connector port 34 of the housing 3. The first plug piece 42 and the second plug piece 43 are each formed of a cut-and-raised portion (cut-and-bent portion) of a metal plate that constitutes the cover 4. Further, the cover 4 has a rib 44 that extends in the long side direction (X-axis direction) thereof, and the cover 4 is reinforced by the rib 44.

[0063] Here, the dimension of the cover 4 in the long side direction is larger than the dimension of the housing 3. Also, in a state in which the cover 4 is joined to the housing 3, at least both end portions of the cover 4 in the long side direction are exposed to the outside from the housing 3 in plan view. In other words, the cover 4 has a protruding portion 45 that protrudes outward from the outer periphery of the housing 3 in plan view. The active ingredient generation system 1 is mounted to a mounting object (in the present embodiment, a vehicle) by fixing the protruding portion 45 of the cover 4 to the mounting object, for example, with a screw.

[0064] The buffer 41 is sandwiched between the cover 4 and a portion of the internal member 2. That is, the internal member 2 and the buffer 41 are accommodated in the internal space of the housing 3 surrounded by the housing 3 and the cover 4. In the present embodiment, the buffer 41 is attached to the facing surface of the cover 4 that faces the housing 3.

[0065] Further, in the present embodiment, the buffer 41 is arranged to be sandwiched between the fan motor 22, which is a portion of the internal member 2, and the cover 4. That is, as described above, the internal member 2 includes the fan motor 22 as a blower that generates an airflow for outputting the active ingredient from the discharge port 31 to the outside of the housing 3. Also, the buffer 41 is in contact with at least the fan motor 22.

[0066] Therefore, the fan motor 22, which is part of the internal component 2, does not directly contact the cover 4, but a buffer 41 is inserted between the fan motor 22 and the cover 4. The buffer 41 is elastic and, for example, is made of a cushioning material such as EPDM foam. Therefore, when the cover 4 is engaged with the housing 3, the buffer 41 is compressed between the cover 4 and the fan motor 22, which is part of the internal component 2, and the internal component 2 is pushed towards the bottom surface 310 of the housing 3 (see reference 310) by the elastic force of the buffer 41. Figure 6A The side is pushed. As a result, the movement of the internal component 2 (especially the fan motor 22) in the direction away from the bottom surface 310 of the housing 3 and the vibration of the internal component 2 (especially the fan motor 22) are suppressed. In this embodiment, in particular, since the buffer body 41 is in contact with the fan motor 22, which is prone to mechanical vibration due to its movable part, the mechanical vibration generated by the fan motor 22 is easily suppressed.

[0067] The airflow component 5 is housed within the housing 3. That is, the internal components 2 and the buffer body 41, as well as the airflow component 5, are housed within the internal space of the housing 3, which is surrounded by the housing 3 and the cover 4. In this embodiment, the airflow component 5 is disposed between the internal components 2 and the cover 4, fixed to the cover 4. The airflow component 5 forms an airflow path between the air supply port 32 and the exhaust port 31 of the housing 3 for airflow (wind) to pass through. In other words, the airflow component 5 forms an airflow path within the housing 3 by dividing the internal space of the housing 3 into a space for airflow and a space outside that space.

[0068] Here, the fan motor 22 and the discharge section 21 of the internal component 2 are arranged in the middle of the air passage formed by the air passage component 5. The fan motor 22 generates airflow (wind) that passes through the air passage and flows from the air supply port 32 toward the exhaust port 31. In this embodiment, the discharge section 21 is arranged downstream of the fan motor 22 in the air passage, that is, between the fan motor 22 and the exhaust port 31.

[0069] Therefore, the air introduced into the housing 3 from the air supply port 32 moves through the air passage formed by the air passage member 5 within the housing 3 to the outlet 31, and is discharged from the outlet 31 to the outside of the housing 3. Furthermore, the active ingredient generated by the discharge section 21 is discharged from the outlet 31 to the outside of the housing 3 along with the airflow generated by the fan motor 22. In other words, a fan motor 22, serving as an air supply section, is disposed between the air supply port 32 and the discharge section 21 in the air passage, and the active ingredient generated by the discharge section 21 is pushed out by the fan motor 22 and discharged to the outside of the housing 3.

[0070] The airflow formed by the airflow component 5 includes an air supply airflow upstream of the fan motor 22 and an exhaust airflow downstream of the fan motor 22. That is, the air supply airflow connects the fan motor 22 to the air supply port 32, and the exhaust airflow connects the fan motor 22 to the exhaust port 31. The airflow component 5 controls the flow of air (containing the active ingredient) to ensure that the active ingredient is efficiently discharged to the outside of the housing 3. Here, the airflow component 5 has an upstream block and a downstream block integrally formed. The upstream block forms the air supply airflow upstream from the view of the fan motor 22. The downstream block forms the exhaust airflow downstream from the view of the fan motor 22. In this way, the airflow component 5 forms an airflow within the housing 3 that includes an air supply airflow and an exhaust airflow for airflow.

[0071] Furthermore, in this embodiment, the airflow component 5 is made of synthetic resin. That is, the airflow component 5, made of molded resin, is fixed to the cover 4, which is made of a metal plate. Figure 5 As shown, the airflow component 5 is fixed to the cover 4, for example, by means of thermal riveting. That is, the airflow component 5 has multiple (three in this case) riveting portions 55. By riveting these multiple riveting portions 55 to multiple (three in this case) riveting holes formed in the cover 4, the airflow component 5 is fixed to one side (the positive side of the Z-axis) of the cover 4. Furthermore, the airflow component 5 is integrally formed with a nozzle 51 for discharging air containing the active ingredient. That is, the active ingredient generating system 1 according to this embodiment includes a nozzle 51, which is integrated with the airflow component 5. The nozzle 51 is disposed within the outlet 31 of the housing 3, and air to be discharged from the outlet 31 to the outside of the housing 3 is discharged to the outside of the housing 3 through the nozzle 51.

[0072] (2.3) Structure of internal components

[0073] Next, refer to Figure 5 , Figure 6A as well as Figure 6B Let me explain the structure of internal component 2.

[0074] In addition to the discharge unit 21 and the fan motor 22, the internal component 2 also includes a fan control system 10, a drive circuit 23, and a liquid supply unit 24 (see reference). Figure 6B ) and the second temperature sensor 28 (refer to Figure 6B ).

[0075] like Figure 6B As shown, the discharge section 21 has a discharge electrode 211 and a counter electrode 212. The discharge section 21 also includes a retaining block 213 made of synthetic resin with electrical insulation properties. As described above, the discharge section 21 generates discharge by applying a voltage between the discharge electrode 211 and the counter electrode 212.

[0076] The discharge electrode 211 is a cylindrical electrode extending along the X-axis. The discharge electrode 211 is a needle electrode in which at least its front end 211a in the long side direction (X-axis direction) is formed into a tapered shape. The term "tapered shape" as used herein is not limited to a pointed shape, but also includes a shape with rounded corners at the front. Specifically, in... Figure 6B In this example, the front end portion 211a of the discharge electrode 211 is spherical, and the half of the front end portion 211a closest to the discharge electrode 211 (that is, the hemisphere on the positive side of the X-axis) forms a tapered shape with rounded corners. As an example, the discharge electrode 211 is made of a conductive metallic material such as titanium alloy (Ti alloy).

[0077] The counter electrode 212 is configured to face the front end portion 211a of the discharge electrode 211. In this embodiment, the counter electrode 212 is made of a metal plate and is positioned separately from the front end portion 211a of the discharge electrode 211 along the positive X-axis. A through hole 212a is formed in a portion of the counter electrode 212, penetrating the metal plate in the thickness direction (X-axis direction). The counter electrode 212 includes a plurality of (four in one example) protruding electrode portions 212b protruding from the periphery of the through hole 212a toward the center of the through hole 212a. As an example, the counter electrode 212 is made of a conductive metal material such as titanium alloy (Ti alloy).

[0078] The retaining block 213 holds the discharge electrode 211 and the counter electrode 212. As an example, the retaining block 213 is coupled to the counter electrode 212 by means of thermal riveting or the like. Thus, the counter electrode 212 is held in the retaining block 213. With the discharge electrode 211 and the counter electrode 212 held in the retaining block 213, viewed from the central axis of the discharge electrode 211, the center of the through hole 212a is located on the central axis of the discharge electrode 211.

[0079] The fan motor 22 functions as an air supply unit that generates airflow for expelling the active ingredient. As described above, the fan motor 22 has a rotor 101 and a stator 102. The fan motor 22 receives an electrical signal (in this embodiment, a DC voltage) from the fan control system 10 to rotate the rotor 101. When the rotor 101 of the fan motor 22 rotates, airflow (wind) is generated as the blades 104 included in the rotor 101 rotate. In this embodiment, as an example, the fan motor 22 is an axial flow fan that generates airflow along the rotation axis of the rotor 101. The fan motor 22 is configured such that the rotation axis of the rotor 101 is parallel to the X-axis. Therefore, the fan motor 22 generates airflow that flows from the air supply port 32 along the X-axis toward the exhaust port 31, that is, airflow that flows in the positive direction of the X-axis. The fan motor 22 will be described in detail in the section “(2.5) Structure of the Fan Motor”.

[0080] The fan control system 10 controls the fan motor 22. In the present embodiment, the fan control system 10 has, for example, a microcontroller having one or more processors and one or more memories as a main structure. That is, the functions of the fan control system 10 are realized by the processors of the microcontroller executing programs recorded in the memories of the microcontroller. The programs can be recorded in the memories in advance, can be provided through an electric communication line such as the Internet, or can be recorded in a non-transitory recording medium such as a memory card. Also, in the present embodiment, the fan control system 10 controls the fan motor 22 by applying a direct-current voltage as an electric signal to the fan motor 22, and thus has a voltage conversion circuit 13 for converting the direct-current voltage (see FIG. 1). The fan control system 10 will be described in detail in the section "(2.6) Structure of the fan control system". Figure 1 ) The fan control system 10 will be described in detail in the section "(2.6) Structure of the fan control system".

[0081] The drive circuit 23 includes a circuit board 230 and various mounting components such as the transformer 25. The mounting components such as the transformer 25 are mounted to the circuit board 230. Also, in the present embodiment, not only the mounting components (the transformer 25 and the like) that constitute the drive circuit 23 are directly or indirectly mounted to the circuit board 230, but also the fan control system 10, the discharge portion 21, the fan motor 22, and the liquid supply portion 24 are directly or indirectly mounted to the circuit board 230. In addition, a connector 27 for electrically connecting the drive circuit 23 to an external circuit is also mounted to the circuit board 230. The mounting referred to here means mechanical and electrical connection with the circuit board 230. That is, the mounting components (the transformer 25 and the like), the fan control system 10, the discharge portion 21, the fan motor 22, the liquid supply portion 24, and the connector 27 are mechanically and electrically connected to the circuit board 230, for example, by welding or connector connection. In the present embodiment, the mechanical connection of the fan motor 22 to the circuit board 230 is realized by a snap-fit for hanging a claw (hook) provided to the fan motor 22 to the circuit board 230.

[0082] The drive circuit 23 is a circuit that drives the discharge portion 21. That is, the drive circuit 23 is a circuit that causes the discharge portion 21 to generate discharge by applying an applied voltage between the discharge electrode 211 and the counter electrode 212 that constitute the discharge portion 21. The "applied voltage" referred to in the present disclosure means a voltage applied by the drive circuit 23 between the discharge electrode 211 and the counter electrode 212 in order to generate discharge.

[0083] The drive circuit 23 receives a power supply from a power source to generate a voltage (applied voltage) to be applied to the discharge section 21. The "power source" referred to here is a power source that supplies a driving power to the drive circuit 23 and the like, and is a power source circuit that generates a direct current voltage of several to several tens of volts, for example. The drive circuit 23 boosts an input voltage from the power source using a transformer 25, for example, and outputs the boosted voltage as the applied voltage. That is, in the drive circuit 23, a high voltage (applied voltage) for causing the discharge section 21 to generate a discharge is generated at a secondary side of the transformer 25.

[0084] Here, the drive circuit 23 includes a reference potential point. The reference potential point is electrically connected to the metal body 30. In the present embodiment, the reference potential point is a ground in the drive circuit 23. That is, the metal body 30 of the housing 3 is electrically connected to the ground as the reference potential point of the drive circuit 23, thereby realizing a frame ground.

[0085] Further, the drive circuit 23 is electrically connected to the discharge section 21 (the discharge electrode 211 and the counter electrode 212). Specifically, a terminal at the secondary side of the transformer 25 in the drive circuit 23 is electrically connected to the discharge section 21 through a harness 26. In the present embodiment, the drive circuit 23 applies a high voltage between the discharge electrode 211 and the counter electrode 212 with the discharge electrode 211 as a negative electrode (ground) and the counter electrode 212 as a positive electrode. Therefore, the terminal at the secondary side of the transformer 25 is connected to the counter electrode 212 in the discharge section 21, and the ground is connected to the discharge electrode 211 as the reference potential point provided in the circuit board 230. Thus, the drive circuit 23 applies a high voltage with the discharge electrode 211 as a low potential side and the counter electrode 212 as a high potential side to the discharge section 21. The "high voltage" referred to here is a voltage set to generate a full path breakdown discharge or a partial breakdown discharge in the discharge section 21 as described later, and is a voltage of about 6.0 kV in peak value, for example. The full path breakdown discharge and the partial breakdown discharge will be described in detail in the item "(2.4) Action of the active ingredient generation system".

[0086] The liquid supply section 24 supplies a liquid to the discharge electrode 211. In the active ingredient generation system 1, the liquid is electrostatically atomized by a discharge generated by the discharge section 21. That is, for example, in a state where the liquid supplied from the liquid supply section 24 adheres to the surface of the discharge electrode 211 and the liquid is held in the discharge electrode 211, an applied voltage is applied to the discharge section 21, and thus the discharge section 21 generates a discharge. In this configuration, the liquid held by the discharge electrode 211 is electrostatically atomized by the discharge generated by the discharge section 21. In the present disclosure, the liquid held by the discharge electrode 211, that is, the liquid that is the object of electrostatic atomization, is also simply referred to as "liquid".

[0087] The liquid supply portion 24 supplies a liquid for electrostatic atomization to the discharge electrode 211. As an example, the liquid supply portion 24 includes a Peltier element, and supplies the liquid by cooling the discharge electrode 211 with the Peltier element to cause dew to occur on the discharge electrode 211. In this liquid supply portion 24, the discharge electrode 211 that is thermally coupled to the Peltier element is cooled by energizing the Peltier element from the drive circuit 23. At this time, moisture in the air condenses and adheres to the surface of the discharge electrode 211 as dew. That is, the liquid supply portion 24 cools the discharge electrode 211 to generate dew as a liquid on the surface of the discharge electrode 211. In this configuration, the liquid supply portion 24 can supply the liquid (dew) to the discharge electrode 211 using the moisture in the air, and thus does not need to supply and replenish the liquid to the active ingredient generation system 1.

[0088] In addition, the second temperature sensor 28 directly or indirectly detects the temperature of the surroundings of the fan motor 22. The second temperature sensor 28 is constituted by, for example, a thermistor. The active ingredient generation system 1 outputs the detection result of the second temperature sensor 28 to the fan control system 10. As shown in FIG. 2, the second temperature sensor 28 is mounted to the circuit board 230, for example, together with the discharge portion 21, and detects the temperature of the circuit board 230 or the temperature of the internal space of the housing 3, thereby directly detecting the temperature of the surroundings of the fan motor 22. Figure 6B

[0089] (2.4) Operation of the active ingredient generation system

[0090] The active ingredient generation system 1 of the configuration described above generates discharge in the discharge portion 21 (the discharge electrode 211 and the counter electrode 212) by the drive circuit 23 operating as follows.

[0091] That is, the operation mode of the drive circuit 23 includes two modes of a discharge mode and a cutoff mode. The discharge mode is a mode for causing the applied voltage to rise with the passage of time and develop from corona discharge to form a discharge path in which at least a part is insulatively broken down between the discharge electrode 211 and the counter electrode 212 to generate a discharge current. The cutoff mode is a mode for causing the discharge portion 21 to be in an overcurrent state to cut off the discharge current. The "discharge current" in the present disclosure refers to a relatively large current that flows through the discharge path, and does not include a small current of several μA or so that is generated in the corona discharge before the discharge path is formed. The "overcurrent state" in the present disclosure refers to a state in which a current above a set value flows through the discharge portion 21 because the load is reduced due to discharge.

[0092] ​In the present embodiment, during the driving period, the driving circuit 23 operates in a manner that alternately repeats the discharge mode and the cut-off mode. Here, the driving circuit 23 switches between the discharge mode and the cut-off mode at a driving frequency, so that the magnitude of the applied voltage to the discharge section 21 periodically varies at the driving frequency. The "driving period" in the present disclosure is a period during which the driving circuit 23 operates to cause the discharge section 21 to generate a discharge.

[0093] That is, the driving circuit 23 does not maintain the magnitude of the voltage applied to the discharge section 21 including the discharge electrode 211 at a constant value, but causes the magnitude of the voltage to periodically vary at the driving frequency within a prescribed range. The driving circuit 23 intermittently generates a discharge by causing the magnitude of the applied voltage to periodically vary. That is, a discharge path is periodically formed in cooperation with the variation period of the applied voltage, so that a discharge is periodically generated. Hereinafter, the period during which a discharge (full-path breakdown discharge or partial-breakdown discharge) is generated will also be referred to as a "discharge period".

[0094] By the above-described operation, the magnitude of the electric energy acting on the liquid held by the discharge electrode 211 periodically varies at the driving frequency, as a result of which the liquid held by the discharge electrode 211 mechanically vibrates at the driving frequency.

[0095] In summary, by applying a voltage from the driving circuit 23 to the discharge section 21 including the discharge electrode 211, a force generated by an electric field acts on the liquid held by the discharge electrode 211 to deform the liquid. In particular, in the present embodiment, a voltage is applied between the opposing electrode 212 facing the tip portion 211a of the discharge electrode 211 and the discharge electrode 211, and thus a force in a direction in which the opposing electrode 212 is stretched by an electric field acts on the liquid. As a result, the liquid held by the tip portion 211a of the discharge electrode 211 is expanded toward the opposing electrode 212 along the central axis of the discharge electrode 211 (that is, along the X-axis) by the force generated by the electric field, and forms a conical shape called a Taylor cone. If the voltage applied to the discharge section 21 decreases, the force acting on the liquid due to the electric field also decreases, and the liquid deforms from the state of the Taylor cone. As a result, the liquid held by the tip portion 211a of the discharge electrode 211 contracts.

[0096] Furthermore, the magnitude of the voltage applied to the discharge section 21 periodically varies at the driving frequency, and thus the liquid held by the discharge electrode 211 expands and contracts along the central axis of the discharge electrode 211 (that is, along the X-axis). In particular, since a discharge is generated due to the electric field being concentrated at the tip portion (apex portion) of the Taylor cone, an insulation breakdown is generated in a state in which the tip portion of the Taylor cone is sharp. Thus, a discharge (full-path breakdown discharge or partial-breakdown discharge) is intermittently generated in cooperation with the driving frequency.

[0097] That is, if the liquid held by the discharge electrode 211 is formed into a Taylor cone by the force generated by the electric field, the electric field is easily concentrated between the tip (apex) of the Taylor cone and the counter electrode 212, for example. Thus, a discharge of a relatively high energy is generated between the liquid and the counter electrode 212, and the corona discharge generated in the liquid held by the discharge electrode 211 can develop into a discharge of a higher energy. As a result, at least a part of the discharge path between the discharge electrode 211 and the counter electrode 212 is intermittently formed to be insulation breakdown.

[0098] Thus, the liquid held by the discharge electrode 211 is electrostatically atomized by the discharge. As a result, in the effective component generation system 1, a nanometer-sized charged fine particle liquid containing OH radicals is generated. That is, a charged fine particle water as an effective component is generated by the discharge section 21. The generated charged fine particle liquid is discharged to the outside of the casing 3 through the discharge port 31.

[0099] Next, the full-path breakdown discharge and the partial breakdown discharge as discharge modes will be described.

[0100] The full-path breakdown discharge is a discharge mode generated by developing a corona discharge to full-path breakdown between a pair of electrodes (the discharge electrode 211 and the counter electrode 212). That is, in the full-path breakdown discharge, a discharge path in which the entire insulation is broken down is generated between the discharge electrode 211 and the counter electrode 212.

[0101] The "insulation breakdown" in the present disclosure means that the electrical insulation of an insulator (including a gas) for isolating conductors is broken down so that the insulation state cannot be maintained. The insulation breakdown of a gas is generated, for example, by ionization of ionizable molecules due to collision with other gas molecules after being accelerated by an electric field, a sharp increase in ion concentration, and gas discharge.

[0102] On the other hand, the partial breakdown discharge is a discharge mode in which a corona discharge develops to form a discharge path in which insulation is locally broken down between a pair of electrodes (the discharge electrode 211 and the counter electrode 212). That is, in the partial breakdown discharge, a discharge path in which insulation is locally broken down is generated between the discharge electrode 211 and the counter electrode 212. That is, in the partial breakdown discharge, a discharge path in which insulation is locally (partially) broken down is formed between the discharge electrode 211 and the counter electrode 212. As such, in the partial breakdown discharge, a discharge path is formed between the discharge electrode 211 and the counter electrode 212, which is locally insulation breakdown and does not reach full-path breakdown.

[0103] However, in the present embodiment, regardless of which of the full-path breakdown discharge and the partial breakdown discharge, the insulation breakdown between the pair of electrodes (the discharge electrode 211 and the counter electrode 212) is not continuously generated, but is intermittently generated. Therefore, the discharge current generated between the pair of electrodes (the discharge electrode 211 and the counter electrode 212) is also intermittently generated.

[0104] That is, in a case where the power supply (the drive circuit 23) does not have a current capacity required to maintain the discharge path, or the like, the voltage applied between the pair of electrodes is reduced from the time when the corona discharge just develops to the insulation breakdown, the discharge path is interrupted, and the discharge stops. The "current capacity" referred to here is a capacity of a current that can be discharged in a unit time. By repeating the generation and the stop of the discharge like this, the discharge current intermittently flows. Like this, the discharge method in the active ingredient generation system 1 according to the present embodiment is different from the glow discharge and the arc discharge in which the insulation breakdown is continuously generated (that is, the discharge current is continuously generated) in that the discharge method repeats a state in which the discharge energy is high and a state in which the discharge energy is low.

[0105] Further, in the full-path breakdown discharge or the partial breakdown discharge, compared to the corona discharge, the active ingredients such as the free radicals are generated with a larger energy, and a large amount of the active ingredients is generated that is about two to ten times larger than that of the corona discharge. The active ingredients generated like this are not limited to sterilization, deodorization, moisturization, freshness preservation, and virus inactivation, but also become a basis for playing a useful effect in various scenes.

[0106] In addition, in the partial breakdown discharge, compared to the full-path breakdown discharge, it is also possible to suppress the disappearance of the active ingredients due to an excessive energy, and it is also possible to achieve an improvement in the generation efficiency of the active ingredients. That is, in the full-path breakdown discharge, the energy involved in the discharge is excessively high, and therefore a part of the active ingredients generated disappears, which can lead to a decrease in the generation efficiency of the active ingredients. In contrast, in the partial breakdown discharge, compared to the full-path breakdown discharge, the energy involved in the discharge is suppressed to be small, and therefore it is possible to reduce the amount of the disappearance of the active ingredients due to exposure to an excessive energy, and thus achieve an improvement in the generation efficiency of the active ingredients.

[0107] Also, in the partial breakdown discharge, compared with the full-path breakdown discharge, the concentration of the electric field is mitigated. That is, in the full-path breakdown discharge, a large discharge current momentarily flows between the discharge electrode 211 and the counter electrode 212 through a discharge path in which breakdown occurs in all paths, and at this time, the resistance becomes very small. In contrast, in the partial breakdown discharge, the concentration of the electric field is mitigated, and thus the maximum value of the current momentarily flowing between the discharge electrode 211 and the counter electrode 212 when a discharge path in which breakdown occurs locally is formed is suppressed to be smaller than in the full-path breakdown discharge. Thus, in the partial breakdown discharge, compared with the full-path breakdown discharge, the generation of nitrogen oxides (NOx) is suppressed, and also the generation of electromagnetic noise is suppressed.

[0108] (2.5) Structure of fan motor

[0109] Next, the structure of the fan motor 22 according to the present embodiment will be described with reference to Figures 1-2C .

[0110] As shown in Figure 1 , the fan motor 22 includes a driver 227 and a coil 222. The driver 227 receives an electric signal from the fan control system 10 to drive the coil 222. The coil 222 is driven by the driver 227 to provide a rotational force to the rotor 101 to rotate the rotor 101.

[0111] In the present embodiment, the fan motor 22 has a DC (direct current) brushless motor as a main structure that operates by being applied with a direct current voltage. The fan motor 22 having the DC brushless motor as the main structure drives the coil 222 included in the stator 102 in accordance with the magnitude of the direct current voltage input (applied) thereto, thereby rotating the rotor 101 including the permanent magnet 226 (see Figure 2A ). That is, the fan motor 22 rotates the rotor 101 by changing the magnetic field generated by the coil 222 of the stator 102 to provide a rotational force to the permanent magnet 226 of the rotor 101. Therefore, in the present embodiment, the driver 227 includes, for example, a semiconductor element or the like, and controls the current flowing through the coil 222 in accordance with the direct current voltage input as an electric signal from the fan control system 10, thereby changing the magnetic field generated by the coil 222.

[0112] In the present embodiment, it is assumed that the fan motor 22 operates at a rotational speed and a torque proportional to the magnitude of the direct-current voltage input (applied) thereto. That is, if the direct-current voltage as an electric signal applied to the fan motor 22 from the fan control system 10 becomes higher, the driver 227 drives the coil 222 in a manner such that the rotational speed of the fan motor 22 increases in proportion to the increase in the direct-current voltage. Conversely, if the direct-current voltage as an electric signal applied to the fan motor 22 from the fan control system 10 becomes lower, the driver 227 drives the coil 222 in a manner such that the rotational speed of the fan motor 22 decreases in proportion to the decrease in the direct-current voltage.

[0113] Figure 2A is a schematic cross-sectional view that schematically shows the structure of the fan motor 22. That is, the fan motor 22 has a rotor 101, a stator 102, and an impregnated bearing 103. In the present embodiment, the fan motor 22 further has a driver 227. Here, the stator 102 includes a coil 222, a housing 223, and a cylindrical portion 224. The rotor 101 includes a vane 104, a shaft 225, and a permanent magnet 226.

[0114] The housing 223 is formed in a box shape, constituting the outer shape of the fan motor 22. In the present embodiment, the housing 223 is made of synthetic resin, for example, and is integrally molded with the cylindrical portion 224. The cylindrical portion 224 protrudes from the central portion of the bottom surface of the housing 223. Inside the housing 223, the rotor 101 including the vane 104, the impregnated bearing 103, the driver 227, the coil 222, and the like are housed.

[0115] The cylindrical portion 224 functions to hold the impregnated bearing 103 inside the housing 223. The cylindrical portion 224 holds the impregnated bearing 103 by housing the impregnated bearing 103 inside thereof. Inside the cylindrical portion 224, in addition to the impregnated bearing 103, a nonwoven fabric impregnated with a lubricant 105 is housed. That is, the lubricant 105 is impregnated not only in the impregnated bearing 103 but also in the nonwoven fabric. Thus, by impregnating the impregnated bearing 103 with the lubricant 105 impregnated in the nonwoven fabric, the lubricant 105 of the impregnated bearing 103 is less likely to run out even without replenishing the lubricant 105 into the cylindrical portion 224. However, the nonwoven fabric is not essential to the fan motor 22, and for example, the nonwoven fabric can be omitted, and a space in which the lubricant 105 is stored can be provided around the impregnated bearing 103.

[0116] The coil 222 is formed in a circular ring shape, and is disposed around the cylindrical portion 224. Further, the permanent magnet 226 of the rotor 101 is disposed around the coil 222. That is, the coil 222 is disposed at a position surrounded by the permanent magnet 226 of the rotor 101. The coil 222 is a part of the stator 102, and is thus fixed in a manner such that it does not relatively move with respect to the housing 223.

[0117] The impregnated bearing 103 is a cylindrical component that is held within the cylindrical portion 224 by the cylindrical portion 224. The shaft 225 of the rotor 101 is inserted into the impregnated bearing 103. Thus, the impregnated bearing 103 supports the shaft 225 of the rotor 101 in a rotatable manner. In other words, the stator 102 supports the rotor 101 in a rotatable manner via the cylindrical portion 224 and by means of the impregnated bearing 103. Here, the rotor 101 rotates about the central axis of the shaft 225. That is, the axis of rotation of the rotor 101 coincides with the central axis of the shaft 225.

[0118] The blade 104 is mechanically coupled to the front end of the shaft 225. Thus, by rotating the rotor 101 about its rotation axis (the central axis of the shaft 225), the blade 104 is rotated. In this embodiment, the fan motor 22 is an axial fan, therefore, by rotating the blade 104, airflow is generated along the rotation axis of the rotor 101 (the central axis of the shaft 225).

[0119] The permanent magnet 226, together with the blade 104, is mechanically coupled to the front end of the shaft 225. The permanent magnet 226 is positioned within the area surrounded by the blade 104. The permanent magnet 226 is positioned around the coil 222 with a certain gap between it and the coil 222. Therefore, the rotor 101 receives a rotational force corresponding to the change in the magnetic field generated by the coil 222 through the permanent magnet 226, and rotates around the axis of rotation of the rotor 101 (the central axis of the shaft 225).

[0120] In addition, in this embodiment, the fan motor 22 also has a first temperature sensor 221 (see reference). Figure 1 The first temperature sensor 221 directly or indirectly detects the temperature of the impregnated bearing 103. The first temperature sensor 221 is, for example, composed of a thermistor. The fan motor 22 outputs the detection result of the first temperature sensor 221 to the fan control system 10. The first temperature sensor 221 indirectly detects the temperature of the impregnated bearing 103, for example, by detecting the temperature of the shaft 225 or the temperature of the internal space of the cylindrical portion 224.

[0121] In addition, such as Figure 2B and Figure 2C As shown, the impregnated bearing 103 is impregnated with lubricant 105. Figure 2B and Figure 2Cis a schematic cross-sectional view that schematically represents a main portion of the vicinity of a cross section of the impregnated bearing 103. In the present embodiment, as an example, the impregnated bearing 103 is formed by sintering metal powder, and is capable of impregnating the lubricant 105. That is, the impregnated bearing 103 realizes a porous structure having a large number of gaps (voids) by a sintered body of metal powder, and is used in a state in which the lubricant 105 is impregnated in the large number of gaps. The impregnated bearing 103 basically uses a capillary phenomenon to suck the lubricant 105 into the large number of gaps, and maintains a state in which the lubricant 105 is held in the large number of gaps. In the present embodiment, as an example, the lubricant 105 is constituted by a lubricating oil (oil) such as synthetic oil or mineral oil. Therefore, the impregnated bearing 103 impregnates (soaks) the oil as the lubricant 105, and is also called an "oil-impregnated bearing".

[0122] According to the impregnated bearing 103 of this structure, when the rotor 101 rotates, the shaft 225 rotates, whereby a pumping action is generated, and the lubricant 105 impregnated in the impregnated bearing 103 seeps to the surface of the impregnated bearing 103. Also, the lubricant 105 generally has a positive coefficient of thermal expansion, and therefore even if the lubricant 105 expands due to friction heat generated by friction between the shaft 225 and the impregnated bearing 103, the lubricant 105 impregnated in the impregnated bearing 103 seeps to the surface of the impregnated bearing 103. In this way, since the lubricant 105 impregnated in the impregnated bearing 103 seeps to the surface of the impregnated bearing 103, a liquid film (oil film) constituted by the lubricant 105 (oil) is formed on the surface (including the inner peripheral surface) of the impregnated bearing 103 as shown in FIG. 2. As a result, the lubricant 105 realizes a lubricating action between the impregnated bearing 103 and the rotor 101. Figure 2B

[0123] On the other hand, if the rotor 101 stops, the pumping action is lost, and in addition, the friction heat is also lost, and therefore the temperature of the lubricant 105 decreases and the lubricant 105 contracts. At this time, the impregnated bearing 103 uses a capillary phenomenon to suck the lubricant 105 into the large number of gaps, and returns to a state in which the lubricant 105 is held in the large number of gaps. This action is repeated, and therefore the impregnated bearing 103 is capable of maintaining the lubricating action even without replenishing the lubricant 105.

[0124] However, in the fan motor 22 using the impregnated bearing 103, in a case in which the amount of impregnation of the lubricant 105 in the impregnated bearing 103 is lower than an appropriate amount, for example, it is possible that the lubricant 105 excessively contracts in a special environment such as a low-temperature environment. Figure 2C The state of the impregnated bearing 103 when the lubricant 105 excessively contracts is schematically represented. In the present embodiment, as an example, the lubricant 105 excessively contracts due to a low-temperature environment, and the amount of impregnation of the lubricant 105 in the impregnated bearing 103 is lower than an appropriate amount. Figure 2C ​In the example of FIG. 10, the lubricant 105 excessively shrinks, so that when a cross section of the impregnated bearing 103 is divided into an outer peripheral portion and an inner portion surrounded by the outer peripheral portion, a state where the lubricant 105 exists only in the inner portion is assumed. In other words, the lubricant 105 does not exist in the vicinity of the surface (including the inner peripheral surface) of the impregnated bearing 103, and the shrunk lubricant 105 exists in a portion (the inner portion) away from the surface of the impregnated bearing 103. In this state, the lubricant 105 impregnated in the impregnated bearing 103 is difficult to seep to the surface of the impregnated bearing 103, so that a good liquid film (oil film) composed of the lubricant 105 (oil) is difficult to form on the surface (including the inner peripheral surface) of the impregnated bearing 103.

[0125] Thus, if the fan motor 22 using the impregnated bearing 103 is driven in a state where the lubricant 105 is excessively shrunk as described above, a good liquid film composed of the lubricant 105 cannot be formed, and sometimes, friction occurs between the impregnated bearing 103 and the shaft 225. That is, if "slip" in which the shaft 225 moves while rubbing the impregnated bearing 103 occurs in a state where the impregnated bearing 103 and the shaft 225 directly contact without the lubricant 105, abnormal noise such as slip noise, vibration, or loss can occur.

[0126] (2.6) Structure of fan control system

[0127] Next, the structure of the fan control system 10 according to the present embodiment will be described with reference to Figure 1 and Figure 3

[0128] The fan control system 10 controls the fan motor 22 by supplying an electric signal to the fan motor 22. As shown in Figure 1 , the fan control system 10 has a control section 11, a switching section 12, and a voltage switching circuit 13. In the present embodiment, as described above, the fan control system 10 has a microcontroller as a main structure, and functions of at least the control section 11 and the switching section 12 are implemented by the microcontroller.

[0129] The control section 11 selects a control mode from among a plurality of control modes including a first mode and a second mode. The first mode is a control mode in which an electric signal is supplied to the fan motor 22 to cause the fan motor 22 to operate at a first rotational speed. The second mode is a control mode in which an electric signal is supplied to the fan motor 22 to cause the fan motor 22 to operate at a second rotational speed lower than the first rotational speed. The control section 11 has a function of selecting the second mode during a period after the fan motor 22 is started and before the first mode is selected (idling function).

[0130] ​That is, the control section 11 has a function of selecting a control mode from among a plurality of control modes to act in a manner of supplying an electric signal corresponding to the selected control mode to the fan motor 22. For example, during the period in which the control section 11 selects the first mode, the control section 11 supplies an electric signal to the fan motor 22 to cause the fan motor 22 to act at the first rotational speed. On the other hand, during the period in which the control section 11 selects the second mode, the control section 11 supplies an electric signal to the fan motor 22 to cause the fan motor 22 to act at the second rotational speed. Also, the control section 11 selects the second mode during the period after the start of the fan motor 22 and before the selection of the first mode by the idling function, thereby controlling the fan motor 22 to suppress the rotational speed of the fan motor 22 immediately after the start to be low (to the second rotational speed).

[0131] In the present embodiment, the fan control system 10 applies a direct current voltage as an electric signal to the fan motor 22, and controls the fan motor 22 by varying the magnitude of the direct current voltage. That is, the electric signal used in the control of the fan motor 22 is the direct current voltage applied to the fan motor 22. Therefore, as for the direct current voltage as an electric signal applied to the fan motor 22 by the fan control system 10 in the first mode and the direct current voltage as an electric signal applied to the fan motor 22 by the fan control system 10 in the second mode, the magnitudes of the voltages are different.

[0132] However, the fan control system 10 controls the fan motor 22 by the electric signal supplied to the fan motor 22, rather than directly determining the rotational speed of the fan motor 22. Also, the fan motor 22 needs time to reach a desired rotational speed even if the same electric signal (direct current voltage) is supplied, and for example, a deviation in the rotational speed can occur due to individual differences of the fan motor 22. Therefore, the fan control system 10 merely supplies the determined electric signal to the fan motor 22 in each control mode to cause the fan motor 22 to ideally act at a desired rotational speed. In other words, the control section 11 switches the electric signal supplied to the fan motor 22 according to the control mode to supply the electric signal determined for each control mode to the fan motor 22.

[0133] In the present embodiment, basically, the fan motor 22 acts at a rotational speed and a torque proportional to the magnitude of the direct current voltage applied to the fan motor 22, and therefore the direct current voltage applied to the fan motor 22 can be regarded as a value corresponding to the rotational speed of the fan motor 22. Therefore, the direct current voltage (first voltage V1) applied to the fan motor 22 by the fan control system 10 in the first mode is higher than the direct current voltage (second voltage V2) applied to the fan motor 22 by the fan control system 10 in the second mode (V1>V2).

[0134] In summary, the first mode is always a control mode in which an electric signal for causing the fan motor 22 to operate at the first rotational speed is supplied to the fan motor 22, and the rotational speed of the fan motor 22 in the first mode is not necessarily the first rotational speed. Therefore, the fan control system 10 supplies, in the first mode, an electric signal set so as to cause the fan motor 22 to ideally operate at the first rotational speed to the fan motor 22, and the electric signal (direct current voltage) at this time is defined as "first voltage V1".

[0135] Likewise, the second mode is always a control mode in which an electric signal for causing the fan motor 22 to operate at the second rotational speed is supplied to the fan motor 22, and the rotational speed of the fan motor 22 in the second mode is not necessarily the second rotational speed. Therefore, the fan control system 10 supplies, in the second mode, an electric signal set so as to cause the fan motor 22 to ideally operate at the second rotational speed to the fan motor 22, and the electric signal (direct current voltage) at this time is defined as "second voltage V2".

[0136] In the present embodiment, the first voltage V1 is a rated voltage of the fan motor 22. Therefore, the fan motor 22 operates at a rated rotational speed when the first voltage V1 is applied thereto. As an example, the first voltage V1 is determined in a range of 6.0 (V) or more and 10.0 (V) or less, and the second voltage V2 is determined in a range of 3.0 (V) or more and 5.0 (V) or less. Also, as an example, it is assumed that the rotational speed of the fan motor 22 when the first voltage V1 is applied thereto is 7000 (rpm) or more and 10000 (rpm) or less. In this regard, as an example, it is assumed that the rotational speed of the fan motor 22 when the second voltage V2 is applied thereto is 3500 (rpm) or more and 5000 (rpm) or less.

[0137] In addition, the control section 11 selects the second mode during a period after the fan motor 22 is started and before the first mode is selected by the idling function, and thus switching from the second mode to the first mode is performed at a certain switching timing. That is, according to the idling function of the control section 11, the control section 11 first selects the second mode as the control mode after the fan motor 22 is started, and thereafter, at a certain switching timing, switches the selected control mode from the second mode to the first mode. Here, the switching timing at which the switching from the second mode to the first mode is performed is determined in accordance with satisfaction of a determination condition described below. That is, the control section 11 determines the switching timing in accordance with satisfaction of a determination condition for starting the first mode. Here, the timing at which the determination condition is satisfied becomes the switching timing.

[0138] In the present embodiment, the determination condition includes a time condition. The time condition is a condition determined with respect to elapsed time after the fan motor 22 is started. As an example, a prescribed idling time (e.g., several tens of seconds to several minutes or so) elapses from a start time point of the second mode is determined as the time condition. In this case, the control section 11 determines that the time condition in the determination condition is satisfied at a time point at which the idling time elapses after the second mode is selected and the fan motor 22 is started, and switches the control mode from the second mode to the first mode. In summary, in the present embodiment, the determination condition for the control section 11 to start the first mode in the idling function includes the time condition related to elapsed time after the fan motor 22 is started.

[0139] In addition, in the present embodiment, the determination condition includes a temperature condition. The temperature condition is a condition determined with respect to the temperature of the impregnated bearing 103. As an example, the temperature of the impregnated bearing 103 being equal to or higher than a prescribed idling temperature is determined as the temperature condition. In this case, the control section 11 determines that the temperature condition in the determination condition is satisfied at a time point at which the temperature of the impregnated bearing 103 rises to the idling temperature after the second mode is selected and the fan motor 22 is started, and switches the control mode from the second mode to the first mode. In summary, in the present embodiment, the determination condition for the control section 11 to start the first mode in the idling function includes the temperature condition related to the temperature of the impregnated bearing 103.

[0140] The temperature of the impregnated bearing 103 is detected by the first temperature sensor 221 of the fan motor 22. Therefore, the control section 11 receives a detection result of the first temperature sensor 221 of the fan motor 22, and determines the temperature condition based on the detection result. That is, if the temperature detected by the first temperature sensor 221 is equal to or higher than the idling temperature, the control section 11 determines that the temperature condition is satisfied. In addition, elapsed time after the fan motor 22 is started is measured, for example, by a timer or the like included in the fan control system 10.

[0141] In the present embodiment, as an example, the control section 11 takes a logical sum of the above-described time condition and the temperature condition as the determination condition. That is, the control section 11 determines that the determination condition is satisfied in accordance with either one of the time condition and the temperature condition being satisfied.

[0142] Figure 3 is a graph showing an electric signal (direct current voltage) supplied from the fan control system 10 to the fan motor 22 at the time of starting the fan motor 22. In Figure 3 , the horizontal axis represents time, and the vertical axis represents voltage. That is, the direct current voltage applied to the fan motor 22 is changed as shown in Figure 3 by the idling function of the control section 11.

[0143] In summary, the control portion 11 selects the second mode during a period after the fan motor 22 is started by the idling function and before the first mode is selected. In the present embodiment, the control portion 11 selects the second mode at a time point tl at which the fan motor 22 is started by being supplied with electric power, and thereafter, switches from the second mode to the first mode at a time point t2 at which either one of the time condition and the temperature condition is satisfied. That is, in the present embodiment, the fan control system 10 is configured to select the second mode at the time point tl at which the fan motor 22 is started, and thereafter, select the first mode at the time point t2 at which either one of the time condition and the temperature condition is satisfied. Figure 3 In the present embodiment, the time point tl is a time point at which the fan motor 22 is started, and the time point t2 is a switching time at which either one of the time condition and the temperature condition is satisfied. Therefore, the control portion 11 selects the second mode during a period T2 from the time point tl to the time point t2, and selects the first mode during a period Tl after the time point t2.

[0144] Thus, during the period T2 in which the second mode is selected, the second voltage V2 is applied to the fan motor 22 to cause the fan motor 22 to operate at the second rotational speed lower than the first rotational speed. That is, during the period T2 immediately after the fan motor 22 is started, the rotational speed of the fan motor 22 is suppressed to be lower than the rated rotational speed by applying the second voltage V2, which is suppressed to be lower than the first voltage VI as the rated voltage, to the fan motor 22.

[0145] On the other hand, during the period Tl in which the first mode is selected, the first voltage VI is applied to the fan motor 22 to cause the fan motor 22 to operate at the first rotational speed higher than the second rotational speed. That is, during the period Tl after the determination condition is satisfied, the rotational speed of the fan motor 22 is gradually increased to the first rotational speed as the rated rotational speed by applying the first voltage VI as the rated voltage to the fan motor 22.

[0146] Here, in the present embodiment, the fan motor 22 is started in the second mode, and therefore, the second voltage V2 is equal to or higher than a minimum voltage (hereinafter referred to as "minimum starting voltage") VO required to start the fan motor 22. Therefore, the second voltage V2 applied to the fan motor 22 in the second mode is set in a range lower than the first voltage VI and equal to or higher than the minimum starting voltage VO. That is, the fan control system 10 according to the present embodiment causes the fan motor 22 to operate in the second mode at a torque equal to or higher than a minimum torque required to start the fan motor 22. In the example shown in FIG. 6, the second voltage V2 is set to be higher than the minimum starting voltage VO. Figure 3

[0147] ​The switching section 12 switches between making the idle function of the control section 11 effective (function of selecting the second mode) and making the function ineffective. The switching section 12 makes the idle function ineffective based on at least environmental information related to the temperature of the surroundings of the fan motor 22. That is, in the present embodiment, the idle function of the control section 11 is not always effective, and can be inactivated by the switching section 12. If the idle function is effective, the control section 11 selects the second mode during a period after the fan motor 22 is started and before the first mode is selected. On the other hand, if the idle function is ineffective, the control section 11 selects the first mode from when the fan motor 22 is started. That is, in the case where the switching section 12 makes the idle function ineffective, the control section 11 does not select the second mode, but selects the first mode from when the fan motor 22 is just started.

[0148] In particular, the switching section 12 makes the idle function ineffective based on environmental information related to the temperature of the surroundings of the fan motor 22, and thus can make the idle function effective to select the second mode only in the case where the temperature of the surroundings of the fan motor 22 satisfies a specific condition. In the present embodiment, as an example, the specific condition for making the idle function effective is set to the temperature of the surroundings of the fan motor 22 being equal to or lower than a threshold temperature Tthl (15°C, as an example). Thus, if the temperature of the surroundings of the fan motor 22 is higher than the threshold temperature Tthl at the time when the fan motor 22 is started, the switching section 12 makes the idle function of the control section 11 ineffective, and causes the control section 11 to select the first mode from when the fan motor 22 is just started.

[0149] The temperature of the surroundings of the fan motor 22 is detected by the second temperature sensor 28. Thus, the switching section 12 receives the detection result of the second temperature sensor 28, and judges the effectiveness / ineffectiveness of the idle function based on the detection result. That is, if the temperature detected by the second temperature sensor 28 at the time when the fan motor 22 is started is equal to or lower than the threshold temperature Tthl, the switching section 12 makes the idle function of the control section 11 effective.

[0150] The voltage conversion circuit 13 converts a direct-current voltage applied to the fan motor 22 as an electric signal. The fan control system 10 according to the present embodiment applies the first voltage VI to the fan motor 22 in the first mode, and applies the second voltage V2 to the fan motor 22 in the second mode. Thus, in the voltage conversion circuit 13, voltage conversion is performed so that at least two stages of the first voltage VI and the second voltage V2 can be output as a direct-current voltage applied to the fan motor 22.

[0151] In the present embodiment, the voltage conversion circuit 13 is implemented by a dropper-type power supply circuit such as a series regulator, for example. Specifically, the voltage conversion circuit 13 switches a direct current voltage applied to the fan motor 22 in accordance with a control signal from the control section 11. Here, when the control section 11 selects the first mode, the voltage conversion circuit 13 applies the first voltage VI as the direct current voltage to the fan motor 22, and when the control section 11 selects the second mode, the voltage conversion circuit 13 applies the second voltage V2 as the direct current voltage to the fan motor 22. As described above, the second voltage V2 is lower than the first voltage VI, and thus the voltage conversion circuit 13 steps down the direct current voltage at least when the second voltage V2 is applied.

[0152] (2.7) Operation of the fan control system

[0153] Next, the operation of the fan control system 10 according to the present embodiment will be described with reference to the flowchart of FIG. 8. Figure 7

[0154] If the fan control system 10 is not powered on (S1: No), the fan control system 10 does not start operation, and the fan control system 10 starts operation by being powered on (S1: Yes).

[0155] When the fan control system 10 starts being powered on (S1: Yes), the fan control system 10 first acquires the ambient temperature of the fan motor 22 (S2). At this time, the fan control system 10 acquires a detection result of the ambient temperature of the fan motor 22 from the second temperature sensor 28. Then, the fan control system 10 determines whether to enable or disable the idle function of the control section 11 by the switching section 12 based on environmental information related to the ambient temperature of the fan motor 22 (S3).

[0156] If the ambient temperature of the fan motor 22 is equal to or lower than the threshold temperature Tthl (S3: Yes), the switching section 12 enables the idle function of the control section 11. Therefore, if the ambient temperature is equal to or lower than the threshold temperature Tthl (S3: Yes), the fan control system 10 selects the second mode by the control section 11 (S4), and applies the second voltage V2 as an electric signal (direct current voltage) to the fan motor 22 (S5). Then, the fan control system 10 determines whether the determination condition is satisfied by the control section 11 (S6), and continues to apply the second voltage V2 (S5) if the determination condition is not satisfied (S6: No).

[0157] In the present embodiment, the determination condition includes a time condition and a temperature condition. Therefore, for example, if a point in time at which the second mode is selected and the fan motor 22 is started up is the time condition, and the ambient temperature of the fan motor 22 is the temperature condition, the fan control system 10 determines whether the determination condition is satisfied based on the time condition and the temperature condition. Figure 3 ​predetermined idling time elapses from the time point t1), the control section 11 determines that the determination condition is satisfied (S6: YES) based on the time condition. Alternatively, for example, if the temperature of the impregnated bearing 103 rises to a predetermined idling temperature after the time point t1) at which the second mode is selected and the fan motor 22 is started (S3: YES), the control section 11 determines that the determination condition is satisfied (S6: YES) based on the temperature condition. Figure 3

[0158] When the determination condition is satisfied (S6: YES), the fan control system 10 selects the first mode by the control section 11 (S7), and applies the first voltage VI as the electric signal (direct current voltage) to the fan motor 22 (S8). Then, if the power-on to the fan control system 10 is not ended (S9: NO), the fan control system 10 continues to apply the first voltage VI (S8).

[0159] When the power-on to the fan control system 10 is ended (S9: YES), the fan control system 10 ends the series of actions including the application of the direct current voltage to the fan motor 22.

[0160] Figure 7 The flowchart is only an example of the actions of the fan control system 10, and the processing can be appropriately omitted or added, and the order of the processing can be appropriately changed.

[0161] The fan control method according to the present embodiment is embodied by the fan control system 10. That is, the actions of the above-described fan control system 10 correspond to the fan control method. Therefore, the fan control method according to the present embodiment controls the fan motor 22 having the rotor 101 including the blade 104, the stator 102, and the impregnated bearing 103 in which the lubricant 105 is impregnated, which holds the rotor 101 in a rotatable manner by the impregnated bearing 103. The fan control method can select the control mode from among a plurality of control modes including the first mode and the second mode. The first mode is a control mode in which the fan motor 22 is supplied with the electric signal (the first voltage VI in the example) to act at the first rotational speed. The second mode is a control mode in which the fan motor 22 is supplied with the electric signal (the second voltage V2 in the example) to act at the second rotational speed lower than the first rotational speed. The fan control method has an idling processing (the processing "S4" to the processing "S8") of selecting the second mode during a period (the period T2 in the example) after the start of the fan motor 22 and before the selection of the first mode. Figure 3 Figure 3 Figure 3 Figure 7

[0162] ​​​​​Further, in the present embodiment, the above-described fan control method can be embodied by a program in a microcontroller or the like. That is, the program according to the present embodiment is a program for embodying the above-described fan control method by one or more processors.

[0163] (3) Effects

[0164] Next, the effects of the fan control system 10 according to the present embodiment will be described.

[0165] First, in an environment at normal temperature (for example, 25°C), when the fan motor 22 is started, a liquid film (oil film) composed of the lubricant 105 (oil) is formed on the surface (including the inner circumferential surface) of the impregnated bearing 103 (refer to Figure 2B ). Thus, the lubricant 105 achieves the lubricating effect between the impregnated bearing 103 and the rotor 101, and therefore, even if the fan motor 22 is controlled in the first mode to operate at the first rotational speed from immediately after the start, no particular problem occurs. In the present embodiment, if the temperature around the fan motor 22 at the time when the fan motor 22 is started is higher than the threshold temperature Tthl, the switching section 12 invalidates the idle function. Therefore, in an environment at normal temperature (for example, 25°C), the fan control system 10 controls the fan motor 22 in the first mode from immediately after the start of the fan motor 22 to operate the fan motor 22 at the first rotational speed.

[0166] On the other hand, in a case where the impregnation amount of the lubricant 105 in the impregnated bearing 103 is lower than the appropriate amount, for example, it is difficult to form a good liquid film composed of the lubricant 105 on the surface of the impregnated bearing 103 in a special environment such as a low-temperature environment (refer to Figure 2C ). In such a condition where the lubricant 105 excessively shrinks, the switching section 12 of the fan control system 10 according to the present embodiment validates the idle function of the control section 11.

[0167] Further, according to the idle function of the control section 11, the second mode is selected during a period from the start of the fan motor 22 and before the selection of the first mode. Therefore, the fan motor 22 operates at the second rotational speed lower than the first rotational speed before the fan motor 22 operates at the first rotational speed. Thus, it is possible to make the fan motor 22 operate in a state where the rotational speed of the fan motor 22 is suppressed to be low immediately after the start of the fan motor 22, and during this period, the impregnated bearing 103 is heated by the friction heat or the like generated by the friction between the shaft 225 and the impregnated bearing 103. When the impregnated bearing 103 is warmed up, the lubricant 105 expands and thus the excessive shrinkage of the lubricant 105 is mitigated, and therefore, the lubricant 105 impregnated in the impregnated bearing 103 seeps to the surface of the impregnated bearing 103, and a good liquid film composed of the lubricant 105 is formed on the surface of the impregnated bearing 103.

[0168] In this case, in the second mode, the rotation speed of the fan motor 22 is suppressed to be low, and thus even in a state where the lubricant 105 is excessively shrunk, it is difficult to cause a problem due to "slipping" in which the shaft 225 moves while rubbing against the impregnated bearing 103. That is, in the second mode, even if slipping occurs, the rotation speed of the fan motor 22 is suppressed to be lower than the first rotation speed, and thus it is difficult to cause a problem such as generation of a noise such as a slipping sound, generation of vibration, or generation of a loss. As a result, according to the fan control system 10 according to the embodiment, it is difficult to cause a problem such as a noise due to shrinkage of the lubricant 105.

[0169] Also, in the embodiment, the fan motor 22 is used as a blower unit that generates an airflow for discharging the active ingredient in the active ingredient generation system 1, and in the second mode, the amount of generation of the active ingredient is also suppressed. That is, the fan motor 22 is used as a blower unit for discharging the active ingredient in the active ingredient generation system 1, rather than for a purpose such as cooling, but even in the active ingredient generation system 1, the active ingredient is not sufficiently generated immediately after startup. In particular, in the embodiment, the liquid supply unit 24 of the active ingredient generation system 1 supplies liquid by causing dew to be generated at the discharge electrode 211, and thus before a time of several tens of seconds to several minutes or so elapses after startup depending on the environment and the like, a sufficient amount of the active ingredient is not generated. The period during which the fan control system 10 controls the fan motor 22 in the second mode overlaps at least a part of the period immediately after startup of the active ingredient generation system 1 in which the amount of generation of the active ingredient is suppressed as described above.

[0170] In summary, in the embodiment, the fan motor 22 is used as a blower unit that generates an airflow for discharging the active ingredient in the active ingredient generation system 1 including the discharge unit 21 that generates the active ingredient. During the period in which the second mode is selected in the idle function, the discharge unit 21 generates the active ingredient in a smaller amount per unit time than the amount of generation during the period in which the first mode is selected. Thus, according to the fan control system 10 according to the embodiment, it is possible to suppress the rotation speed of the fan motor 22 to be low during the period in which the amount of generation of the active ingredient is small, and it is difficult to cause a problem such as a noise due to shrinkage of the lubricant 105.

[0171] (4) Modification

[0172] Embodiment 1 is only one of various embodiments of the present disclosure. Embodiment 1 can be variously changed according to design and the like as long as the object of the present disclosure can be achieved. Also, the drawings referred to in the present disclosure are schematic drawings, and the size and the thickness ratio of each of the structural elements in the drawings do not necessarily reflect the actual size ratio. Hereinafter, a modification of Embodiment 1 will be described. The modifications described below can be appropriately combined and applied.

[0173] The same functions as those of the fan control system 10 described in Embodiment 1 can also be embodied by a fan control method, a (computer) program, or a non-transitory recording medium on which the program is recorded, and the like.

[0174] The direct current voltage applied to the fan motor 22 in the second mode (second voltage V2) is not limited to a voltage higher than the minimum startup voltage V0, as long as it is set in a range lower than the first voltage VI and equal to or higher than the minimum startup voltage V0. Among others, the direct current voltage applied to the fan motor 22 in the second mode is set to a rotational speed of the fan motor 22 in the second mode that is suppressed to be a rotational speed at which a problem such as generation of a sliding sound or the like, vibration, or loss is unlikely to occur even in a state in which the lubricant 105 is excessively shrunk. For example, the second voltage V2 can be the same value as the minimum startup voltage V0.

[0175] Also, the direct current voltage applied to the fan motor 22 in the second mode can be varied during the period in which the control section 11 selects the second mode, rather than being a constant value (fixed value). For example Figure 8A and Figure 8B as illustrated, the direct current voltage can be varied within the period T2 in which the second mode is selected. Figure 8A and Figure 8B are graphs illustrating an electric signal (direct current voltage) supplied from the fan control system 10 to the fan motor 22 at the time of startup of the fan motor 22. In Figure 8A and Figure 8B , the horizontal axis represents time, and the vertical axis represents voltage.

[0176] That is, in the modified example illustrated in Figure 8A , according to the idle function of the control section 11, the direct current voltage applied to the fan motor 22 in the second mode is continuously raised from the voltage V2 at the time point tl at which the fan motor 22 is started up, as time elapses. Then, at the time point t2 at which the determination condition is satisfied, the second mode is switched to the first mode, and thus the direct current voltage applied to the fan motor 22 is switched to the first voltage VI.

[0177] In the modified example illustrated in Figure 8B , according to the idle function of the control section 11, the direct current voltage applied to the fan motor 22 in the second mode is raised stage by stage (discretely) from the voltage V2 at the time point tl at which the fan motor 22 is started up, as time elapses. That is, at the time point t3 before the time point t2 at which the determination condition is satisfied is reached, the direct current voltage applied to the fan motor 22 is non-continuously switched from the voltage V2 to the voltage V4. Then, at the time point t2 at which the determination condition is satisfied, the second mode is switched to the first mode, and thus the direct current voltage applied to the fan motor 22 is switched to the first voltage VI.

[0178] In addition, the first voltage VI applied to the fan motor 22 in the first mode is not limited to the rated voltage of the fan motor 22, but can be set to a range higher than the second voltage V2.

[0179] The fan control system 10 in the present disclosure includes a computer system. The computer system has a processor and a memory as main structures of hardware. The functions as the fan control system 10 in the present disclosure are realized by executing a program recorded in the memory of the computer system by the processor. The program can be recorded in the memory of the computer system in advance, can be provided through an electric communication line, or can be recorded in a non-transitory recording medium such as a memory card, an optical disc, a hard disk drive, or the like that can be read by the computer system. The processor of the computer system is constituted by one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuit such as the IC or LSI is called in different ways depending on the degree of integration, and includes an integrated circuit called a system LSI, a VLSI (Very Large Scale Integration), or a ULSI (Ultra Large Scale Integration). Also, a FPGA (Field-Programmable Gate Array) programmed after the LSI is manufactured, or a logic device capable of reconfiguring the connection relationship inside the LSI or reconfiguring the circuit division inside the LSI can also be used as the processor. The plurality of electronic circuits can be integrated on one chip or can be provided separately on a plurality of chips. The plurality of chips can be integrated in one device or can be provided separately in a plurality of devices. The computer system described here includes a microcontroller having one or more processors and one or more memories. Thus, with respect to the microcontroller, one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit are constituted.

[0180] In addition, it is not a necessary structure of the fan control system 10 that at least a part of the functions of the fan control system 10 are integrated in one housing. The structural elements of the fan control system 10 can be provided separately in a plurality of housings. Conversely, all the functions of the fan control system 10 can be integrated in one housing.

[0181] The use of the active ingredient generation system 1 is not limited to vehicle-mounted use, and the active ingredient generation system 1 can be used in, for example, a refrigerator, a washing machine, a dryer, an air conditioner, an electric fan, an air cleaner, a humidifier, or a beauty device used in a house or an office, or the like.

[0182] In addition, it is not essential that the fan motor 22 is mainly structured as a DC (direct current) brushless motor, and the fan motor 22 can be, for example, a brush DC (direct current) motor, or an AC (alternating current) motor that operates by being applied with an alternating voltage, or the like. In the case where the fan motor 22 is mainly structured as an AC motor, the electric signal that the fan control system 10 provides to the fan motor 22 is not a direct current voltage but an alternating voltage. Therefore, the fan control system 10 can also control the fan motor 22 by varying the amplitude, frequency, or phase of the alternating voltage as the electric signal.

[0183] In addition, the fan control system 10 can also provide the electric signal to the fan motor 22 separately from the electric power for driving the fan motor 22. In this case, the electric signal is, for example, a signal for communication that transmits information by varying (modulating) the amplitude, frequency, or phase of a carrier, or the like, and the signal is transmitted from the fan control system 10 to the fan motor 22 by an appropriate communication method of wired communication or wireless communication.

[0184] In addition, the determination condition for the control section 11 to start the first mode in the idle function can not include both the time condition and the temperature condition. That is, the determination condition can include only the time condition or only the temperature condition. In the case where the determination condition includes only the time condition, the control section 11 starts the first mode in accordance with the time condition being satisfied regardless of the temperature of the immersed bearing 103. In the case where the determination condition includes only the temperature condition, the control section 11 starts the first mode in accordance with the temperature condition being satisfied regardless of the elapsed time after the fan motor 22 is started.

[0185] In addition, the control section 11 can take the logical product of the time condition and the temperature condition as the determination condition. In this case, the control section 11 determines that the determination condition is satisfied in accordance with both the time condition and the temperature condition being satisfied.

[0186] In addition, the first temperature sensor 221 is not an essential structure of the fan system 100, and can be appropriately omitted. The second temperature sensor 28 is also the same, and is not an essential structure of the effective component generating system 1, and can be appropriately omitted.

[0187] In addition, the first temperature sensor 221 is not limited to a structure that detects the temperature of the shaft 225 or the temperature of the internal space of the cylindrical portion 224. For example, the first temperature sensor 221 can also be housed inside the housing 223, and indirectly detect the temperature of the immersed bearing 103 by detecting the temperature inside the housing 223. Alternatively, the first temperature sensor 221 can also directly detect the temperature of the immersed bearing 103, for example.

[0188] Further, the second temperature sensor 28 is not limited to a structure that detects the temperature of the circuit board 230 or the temperature of the inside of the case 3. For example, the second temperature sensor 28 can also be provided separately from the active ingredient generation system 1 and indirectly detect the ambient temperature of the fan motor 22 by detecting the temperature outside the case 3. Alternatively, the second temperature sensor 28 can also directly detect the ambient temperature of the fan motor 22, for example, by being mounted to the fan motor 22.

[0189] Further, one temperature sensor can also be shared by the first temperature sensor 221 and the second temperature sensor 28. That is, for example, one temperature sensor can also be used in place of the first temperature sensor 221 and the second temperature sensor 28 by detecting both the temperature of the impregnation bearing 103 and the ambient temperature of the fan motor 22 with one temperature sensor mounted to the circuit board 230.

[0190] Further, the timing of switching from the second mode to the first mode is not limited to the timing at which the determination condition is satisfied and can be, for example, after a certain time elapses from the timing at which the determination condition is satisfied. In this case, the first mode is started after a certain time elapses from the determination condition being satisfied, in other words, a time lag can be given from the determination condition being satisfied to the first mode actually being started.

[0191] Further, the voltage conversion circuit 13 is not limited to a drip-type power supply circuit such as a series regulator and can be implemented by a switching-type power supply circuit such as a step-down chopper circuit, for example.

[0192] Further, the discharge electrode 211 and the counter electrode 212 are not limited to titanium alloy (Ti alloy) and can be copper alloy such as copper-tungsten alloy (Cu-W alloy), for example. Further, the discharge electrode 211 is not limited to a shape in which the tip is tapered and can be a shape in which the tip is raised, for example.

[0193] Further, the high voltage applied from the drive circuit 23 to the discharge section 21 is not limited to about 6.0 kV and can be appropriately set depending on the shape of the discharge electrode 211 and the counter electrode 212 or the distance between the discharge electrode 211 and the counter electrode 212, for example.

[0194] Further, the fixing structure of the internal component 2 is not limited to the structure described in Embodiment 1. For example, the fixing of the circuit board 230 to the fixing section 61 is not limited to a structure implemented using fasteners such as screws 71 and nuts 72 and can be implemented by rivet joining, adhesion, or snap fitting, for example. Adhesion includes joining using an adhesive or an adhesive tape, and the like.

[0195] In addition, the liquid supply portion 24 is not a structure necessary for the active ingredient generation system 1, and can be appropriately omitted. In this case, the discharge portion 21 generates active ingredients such as negative ions by discharge (all-path breakdown discharge or partial breakdown discharge) generated between the discharge electrode 211 and the counter electrode 212.

[0196] In addition, the liquid supply portion 24 is not limited to the structure that cools the discharge electrode 211 and causes dew water to be generated at the discharge electrode 211 as in Embodiment 1. The liquid supply portion 24 can be, for example, a structure that supplies liquid from a tank to the discharge electrode 211 using a capillary phenomenon or a pump or the like as a supply mechanism. Also, the liquid is not limited to water (including dew water), and can be a liquid other than water.

[0197] In addition, the drive circuit 23 can be configured to apply a high voltage between the discharge electrode 211 and the counter electrode 212 with the discharge electrode 211 as the positive electrode and the counter electrode 212 as the negative electrode (ground). Also, as long as a potential difference (voltage) is generated between the discharge electrode 211 and the counter electrode 212, the drive circuit 23 can apply a negative voltage to the discharge portion 21 by taking the electrode on the high potential side (positive electrode) as ground and taking the electrode on the low potential side (negative electrode) as a negative potential.

[0198] In addition, in the comparison between two values, "or more" includes both cases where the two values are equal and where one of the two values exceeds the other. However, this is not limiting, and "or more" here can be synonymous with "greater than" that includes only the case where one of the two values exceeds the other. That is, whether or not to include the case where the two values are equal can be arbitrarily changed according to the setting of a threshold or the like, and thus there is no technical difference between "or more" and "greater than". Similarly, "less than" can be synonymous with "or less".

[0199] (Embodiment 2)

[0200] The fan control system 10 according to the present embodiment differs from the fan control system 10 according to Embodiment 1 in that the plurality of control modes from which the control portion 11 can select includes a third mode. Hereinafter, the same structures as in Embodiment 1 are denoted by common reference numerals and appropriate description is omitted.

[0201] The third mode is a control mode in which the electric signal that causes the fan motor 22 to operate at the third rotation speed is supplied to the fan motor 22 all the time. The rotation speed of the fan motor 22 in the third mode is not necessarily the third rotation speed. Therefore, the fan control system 10 supplies the electric signal (direct current voltage) set to cause the fan motor 22 to ideally operate at the third rotation speed to the fan motor 22 in the third mode, and defines the electric signal (direct current voltage) at this time as "third voltage V3".

[0202] The third mode is a control mode in which the electric signal that causes the fan motor 22 to operate at the third rotation speed is supplied to the fan motor 22 all the time. The rotation speed of the fan motor 22 in the third mode is not necessarily the third rotation speed. Therefore, the fan control system 10 supplies the electric signal (direct current voltage) set to cause the fan motor 22 to ideally operate at the third rotation speed to the fan motor 22 in the third mode, and defines the electric signal (direct current voltage) at this time as "third voltage V3".

[0203] In the present embodiment, the third voltage V3 is a voltage higher than the second voltage V2 applied to the fan motor 22 in the second mode and lower than the first voltage VI applied to the fan motor 22 in the first mode.

[0204] That is, according to the fan control system 10 related to the present embodiment, the direct current voltage applied to the fan motor 22 changes as shown in FIG. 7. Figure 9 Figure 9 is a graph showing the electric signal (direct current voltage) supplied from the fan control system 10 to the fan motor 22 at the time of startup of the fan motor 22. In Figure 9 , the horizontal axis represents time, and the vertical axis represents voltage.

[0205] That is, according to the fan control system 10 related to the present embodiment, the direct current voltage applied to the fan motor 22 changes as shown in FIG. 7. Figure 9 ​In this embodiment, the time point t0 is when the fan motor 22 is started, and the time point tl is when the start time has elapsed from the time point t0. Therefore, the control section 11 selects the third mode during the period T3 from the time point t0 to the time point tl, and selects the second mode during the period T2 after the time point tl.

[0206] Thus, during the period Tl in which the third mode is selected, the third voltage V3 is applied to the fan motor 22 to start the fan motor 22 at the third rotational speed higher than the second rotational speed. That is, during the period T3 for starting the fan motor 22, the third voltage V3 higher than the second voltage V2 is applied to the fan motor 22, thereby easily starting the fan motor 22.

[0207] On the other hand, during the period T2 in which the second mode is selected, the second voltage V2 is applied to the fan motor 22 to operate the fan motor 22 at the second rotational speed lower than the third rotational speed. That is, during the period T2 after the fan motor 22 is started, the second voltage V2 lower than the third voltage V3 is applied to the fan motor 22, thereby suppressing the rotational speed of the fan motor 22 to be lower than the rotational speed at the time of start. The subsequent operation is the same as the fan control system 10 related to Embodiment 1.

[0208] Here, in this embodiment, since the fan motor 22 is started in the third mode, the third voltage V3 is equal to or higher than the minimum start voltage V0 required to start the fan motor 22. On the other hand, in the second mode, it is sufficient to maintain the rotation of the fan motor 22 so as not to stop the fan motor 22 which has been started, and thus the second voltage V2 is equal to or higher than the minimum voltage (hereinafter referred to as "minimum maintenance voltage") V5 required to maintain the rotation of the fan motor 22 which has been started. That is, the minimum maintenance voltage V5 is a voltage lower than the minimum start voltage V0. If the direct current applied to the fan motor 22 which has been started is equal to or higher than the minimum maintenance voltage V5, the fan motor 22 continues to rotate, and if it is lower than the minimum maintenance voltage V5, the fan motor 22 stops.

[0209] In this embodiment, since the start of the fan motor 22 is performed in the third mode, the second voltage V2 is set in a range lower than the minimum start voltage V0 and equal to or higher than the minimum maintenance voltage V5. In other words, in the second mode, the fan motor is operated with a torque equal to or higher than a maintenance torque which is lower than the start torque and is the minimum torque required to maintain the rotation of the rotor 101 in the fan motor 22 which has been started. In Figure 9 In the example, the second voltage V2 is set to be lower than the minimum start voltage V0 and higher than the minimum maintenance voltage V5.

[0210] As a modification of Embodiment 2, as Figure 10In the third mode, the third voltage applied to the fan motor 22 can also be the same value as the first voltage VI applied to the fan motor 22 in the first mode, as shown. That is, in the present modification, the electric signal supplied to the fan motor 22 is the same in the first mode and the third mode. In this case, when the fan motor 22 is started, the direct current voltage applied to the fan motor 22 is the first voltage VI as the rated voltage in the third mode, is lowered to the second voltage V2 in the second mode, and is then returned to the first voltage VI in the first mode. In the present modification, the direct current voltage applied to the fan motor 22 can be switched in two stages as long as it can be switched.

[0211] In addition, as another modification of Embodiment 2, the direct current voltage applied to the fan motor 22 in the third mode can be varied during the period in which the control section 11 selects the third mode, instead of being a constant value (fixed value).

[0212] In addition, in Embodiment 2, the direct current voltage (second voltage V2) applied to the fan motor 22 in the second mode can also be the lowest starting voltage VO or more.

[0213] The various structures (including modifications) described in Embodiment 2 can be appropriately combined with the various structures (including modifications) described in Embodiment 1 to be employed.

[0214] (SUMMARY)

[0215] As described above, the fan control system (10) according to the first aspect is a fan control system (10) that controls a fan motor (22). The fan motor (22) has a rotor (101) including a blade (104), a stator (102), and an impregnated bearing (103) in which a lubricant (105) is impregnated, and the fan motor (22) holds the rotor (101) in a rotatable manner by the impregnated bearing (103). The fan control system (10) includes a control section (11) that selects a control mode from among a plurality of control modes including a first mode and a second mode. The first mode is a control mode in which an electric signal is supplied to the fan motor (22) to cause the fan motor (22) to operate at a first rotational speed. The second mode is a control mode in which an electric signal is supplied to the fan motor (22) to cause the fan motor (22) to operate at a second rotational speed that is lower than the first rotational speed. The control section (11) has a function of selecting the second mode during a period after the fan motor (22) is started and before the first mode is selected.

[0216] According to this aspect, the second mode is selected during a period after the fan motor (22) is started and before the first mode is selected by the function of the control section (11). Therefore, the fan motor (22) operates at the second rotational speed lower than the first rotational speed before the fan motor (22) operates at the first rotational speed. Thus, even in a special environment such as a low-temperature environment, the impregnated bearing (103) is heated during the period in which the fan motor (22) operates at the second rotational speed, so that it is difficult to cause a problem such as an abnormal noise due to shrinkage of the lubricant (105).

[0217] In the fan control system (10) according to the second aspect, in the first aspect, the plurality of control modes includes a third mode. The third mode is a control mode in which an electric signal is supplied to the fan motor (22) to cause the fan motor (22) to operate at a third rotational speed higher than the second rotational speed and at a rotational torque higher than a start-up torque required to start the fan motor (22). The control section (11) also has a function of selecting the third mode during a period after the fan motor (22) is started and before the second mode is selected.

[0218] According to this aspect, the start-up of the fan motor (22) becomes easy.

[0219] In the fan control system (10) according to the third aspect, in the second aspect, in the second mode, the fan motor (22) is caused to operate at a rotational torque higher than a maintenance torque required to maintain rotation of a rotor (101) in the fan motor (22) after the start-up and lower than the start-up torque.

[0220] According to this aspect, in the second mode, the rotational torque of the fan motor (22) can be reduced to be lower than the start-up torque, so that it is more difficult to cause a problem such as an abnormal noise due to shrinkage of the lubricant (105).

[0221] In the fan control system (10) according to the fourth aspect, in the second aspect or the third aspect, in the first mode and the third mode, the electric signal supplied to the fan motor (22) is the same.

[0222] According to this aspect, compared with a case in which different electric signals are used in the first mode and the third mode, it is possible to simplify the circuit structure.

[0223] In the fan control system (10) according to the fifth aspect, in the first aspect or the second aspect, in the second mode, the fan motor (22) is caused to operate at a rotational torque higher than a start-up torque required to start the fan motor (22).

[0224] According to this aspect, even in the second mode, the fan motor (22) is easily started.

[0225] In the fan control system (10) according to the sixth aspect, in any one of the first to fifth aspects, the determination condition for the control section (11) to start the first mode includes a time condition related to an elapsed time after the start of the fan motor (22).

[0226] According to this aspect, the switching from the second mode to the first mode can be realized by a simple structure such as a timer.

[0227] In the fan control system (10) according to the seventh aspect, in any one of the first to sixth aspects, the determination condition for the control section (11) to start the first mode includes a temperature condition related to a temperature of the immersed bearing (103).

[0228] According to this aspect, the switching from the second mode to the first mode can be realized in accordance with the temperature of the immersed bearing (103) rather than a certain time, and the anti-interference is strengthened.

[0229] In the fan control system (10) according to the eighth aspect, in any one of the first to seventh aspects, the switching section (12) is further provided. The switching section (12) switches between making the function of the control section (11) to select the second mode effective and making the function ineffective. The switching section (12) makes the function to select the second mode ineffective based on at least environmental information related to the temperature of the surroundings of the fan motor (22).

[0230] According to this aspect, in a situation where the function to select the second mode is not needed, such as when the temperature of the surroundings of the fan motor (22) is sufficiently high, the function to select the second mode is made ineffective, and the startability of the fan motor (22) can be improved.

[0231] In the fan control system (10) according to the ninth aspect, in any one of the first to eighth aspects, the electric signal is a direct-current voltage applied to the fan motor (22).

[0232] According to this aspect, the control of the fan motor (22) becomes simple.

[0233] In the fan control system (10) according to the tenth aspect, in any one of the first to ninth aspects, the fan motor (22) is used as a blowing section that generates an airflow for discharging an active ingredient in an active ingredient generation system including a discharge section that generates the active ingredient. During the selection of the second mode, the discharge section generates the active ingredient at a smaller amount per unit time than during the selection of the first mode.

[0234] According to this aspect, the rotational speed of the fan motor (22) can be suppressed to be low in the second mode at the time of startup of the fan motor (22), while suppressing the influence on the generation of the active ingredient to be small.

[0235] The fan system according to the eleventh aspect includes the fan control system (10) according to any one of the first aspect to the tenth aspect and the fan motor (22).

[0236] According to this aspect, even in a special environment such as a low-temperature environment, the impregnated bearing (103) is heated during the operation of the fan motor (22) at the second rotational speed, so that it is difficult to generate a problem such as an abnormal noise due to shrinkage of the lubricant (105).

[0237] The active ingredient generation system according to the twelfth aspect includes the fan system according to the eleventh aspect and a discharge unit that generates an airflow for discharging the active ingredient.

[0238] According to this aspect, even in a special environment such as a low-temperature environment, the impregnated bearing (103) is heated during the operation of the fan motor (22) at the second rotational speed, so that it is difficult to generate a problem such as an abnormal noise due to shrinkage of the lubricant (105).

[0239] The fan control method according to the thirteenth aspect is a fan control method of controlling a fan motor (22), and is capable of selecting a control mode from among a plurality of control modes including a first mode and a second mode. The fan motor (22) has a rotor (101) including a blade (104), a stator (102), and an impregnated bearing (103) in which a lubricant (105) is impregnated, and the rotor (101) is held in a rotatable manner by the impregnated bearing (103). The first mode is a control mode in which an electric signal is supplied to the fan motor (22) to cause the fan motor (22) to operate at a first rotational speed. The second mode is a control mode in which an electric signal is supplied to the fan motor (22) to cause the fan motor (22) to operate at a second rotational speed that is lower than the first rotational speed. The fan control method has a process of selecting the second mode during a period after startup of the fan motor (22) and before selection of the first mode.

[0240] According to this aspect, even in a special environment such as a low-temperature environment, the impregnated bearing (103) is heated during the operation of the fan motor (22) at the second rotational speed, so that it is difficult to generate a problem such as an abnormal noise due to shrinkage of the lubricant (105).

[0241] The program according to the fourteenth aspect is a program for causing one or more processors to execute the fan control method according to the thirteenth aspect.

[0242] According to this mode, even in a special environment such as a low-temperature environment, the impregnated bearing (103) is heated during the period in which the fan motor (22) is operating at the second rotational speed, so that it is difficult to cause a problem such as a noise due to shrinkage of the lubricant (105).

[0243] As for the structures involved in the second mode to the tenth mode, structures that are not necessary for the fan control system (10) can be appropriately omitted.

[0244] Explanation of Reference Signs

[0245] 10: fan control system; 11: control section; 12: switching section; 22: fan motor; 101: rotor; 102: stator; 103: impregnated bearing; 104: blade; 105: lubricant.

Claims

1. A fan control system that controls a fan motor having a rotor including a blade, a stator, and an impregnated bearing in which a lubricant is impregnated, the fan motor holding the rotor in a rotatable manner by the impregnated bearing, the fan control system having a control section that selects a control mode from among a plurality of control modes including a first mode and a second mode, the first mode being a mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a first rotational speed, the second mode being a mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a second rotational speed that is lower than the first rotational speed, the control section having a function of selecting the second mode during a period after the fan motor is started and before the first mode is selected, wherein the plurality of control modes including a third mode that is a mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a third rotational speed that is higher than the second rotational speed and at a torque that is higher than a start-up torque that is a minimum torque required to start the fan motor, the control section further having a function of selecting the third mode during the period after the fan motor is started and before the second mode is selected.

2. The fan control system according to claim 1, wherein in the second mode, the fan motor is caused to operate at a torque that is higher than a maintenance torque that is lower than the start-up torque and is a minimum torque required to maintain rotation of the rotor in the fan motor after the start-up.

3. The fan control system according to claim 1 or 2, wherein in the first mode and the third mode, the electric signal supplied to the fan motor is the same.

4. The fan control system according to claim 1, wherein in the second mode, the fan motor is caused to operate at a torque that is higher than a start-up torque that is a minimum torque required to start the fan motor.

5. The fan control system according to claim 1 or 2, wherein a determination condition for the control section to start the first mode includes a time condition related to an elapsed time after the fan motor is started.

6. The fan control system according to claim 1 or 2, wherein a determination condition for the control section to start the first mode includes a temperature condition related to a temperature of the impregnated bearing.

7. The fan control system according to claim 1 or 2, wherein a switching section that switches between making the function of the control section to select the second mode effective and making the function ineffective is further provided, the switching section makes the function to select the second mode ineffective based on at least environmental information related to a temperature around the fan motor.

8. The fan control system according to claim 1 or 2, wherein the electric signal is a direct-current voltage applied to the fan motor.

9. The fan control system according to claim 1 or 2, wherein The fan motor is used as a blowing section for generating an airflow for discharging the active ingredient in an active ingredient generation system including a discharge section that generates the active ingredient, The discharge section generates a smaller amount of the active ingredient per unit time during a period when the second mode is selected than during a period when the first mode is selected.

10. A fan system comprising: The fan control system according to any one of claims 1 to 9; and The fan motor.

11. An active ingredient generation system comprising: The fan system according to claim 10; and a discharge section that generates an active ingredient, wherein, The fan motor generates an airflow for discharging the active ingredient.

12. A fan control method for controlling a fan motor having a rotor including a blade, a stator, and an impregnated bearing in which a lubricant is impregnated, the fan motor holding the rotor in a rotatable manner by the impregnated bearing, The fan control method is capable of selecting a control mode from among a plurality of control modes including a first mode and a second mode, The first mode is a mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a first rotational speed, The second mode is a mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a second rotational speed that is lower than the first rotational speed, The fan control method has a process of selecting the second mode during a period after the fan motor is started and before the first mode is selected, wherein The plurality of control modes includes a third mode that is a mode in which an electric signal is supplied to the fan motor to cause the fan motor to operate at a third rotational speed that is higher than the second rotational speed and at a torque that is higher than a start-up torque required to start the fan motor, The fan control method further has a process of selecting the third mode during a period after the fan motor is started and before the second mode is selected.

13. A computer program product including a program for causing one or more processors to execute the fan control method according to claim 12.

14. A computer-readable storage medium storing a program for causing one or more processors to execute the fan control method according to claim 12.

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