Range hood

Abstract

To provide a range hood that can accurately and quickly achieve a constant airflow in response to changes in the static pressure of the piping. [Solution] Voltage application control C4 is responsible for the stability determination process in constant airflow control, which determines the stability of the applied voltage corresponding to the low airflow based on the static pressure in the operating environment of the range hood 10. Here, the stability determination of the applied voltage corresponds to the determination of the set airflow. The constant control voltage Vlx is a provisional value of the constant control voltage before the execution of voltage application control C4, and becomes a determined value at timing t8 after the execution of voltage application control C4. The constant control voltage Vlx, which becomes a determined value after the execution of voltage application control C4, is stored in the storage unit 102 as the stored voltage for the low airflow. The constant control voltage Vlx stored in the storage unit 102 becomes available for use in the next operation.

Description

Technical Field

[0001] The present invention relates to a range hood, and more particularly to a range hood capable of realizing air volume control according to the duct static pressure.

Background Art

[0002] There is known an air volume control device for a range hood that can control the air volume to a desired set air volume and suppress the occurrence of abnormal noise from the fan motor due to an overcurrent flowing through the fan motor or the need for a long time until the air volume reaches the desired set air volume.

[0003] Such an air volume control device for a range hood is configured such that the control unit controls the electrical input value so as to match the relationship (set relationship) between the rotational speed of the fan motor and the electrical input value stored in the storage means according to the set air volume.

[0004] When starting the fan motor, the control unit starts the fan motor by applying a predetermined starting voltage to the fan motor. After the fan motor is started, when the normal control voltage corresponding to the electrical input value obtained to match the set relationship is higher than the predetermined starting voltage by a predetermined allowable voltage or more, the control unit increases the voltage applied to the fan motor from the predetermined starting voltage toward the normal control voltage at a predetermined rising speed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The operating environment of a range hood can change depending on factors such as whether windows are open or closed and the wind outside. For example, the static pressure in the range hood piping may differ between using it with the windows open during the day and using it with the windows closed at night. Similarly, the static pressure in the range hood piping may differ between a calm day and a windy day.

[0007] In other words, simply configuring the system to control the electrical input value so that the relationship between the fan motor's rotation speed stored in the memory means and the electrical input value matches the set airflow rate may not be able to keep up with changes in the piping's static pressure, making it difficult to achieve a constant airflow rate.

[0008] The present invention aims to provide a range hood that can accurately and quickly achieve a constant airflow in response to changes in the static pressure of the piping. [Means for solving the problem]

[0009] The range hood of the present invention comprises a blower driven by an electric motor, a control unit that controls the voltage applied to the electric motor, and a storage unit capable of storing a first applied voltage and a second applied voltage corresponding to a target airflow rate to the electric motor, wherein the storage unit pre-stores the first applied voltage and makes the second applied voltage available for storage by the control unit, and when the storage unit has stored the second applied voltage, the control unit increases the voltage applied to the electric motor after startup at a predetermined speed to the second applied voltage, searches for a voltage at which the voltage applied to the electric motor stabilizes at the target airflow rate after reaching the second applied voltage, and when the storage unit has not stored the second applied voltage, the control unit increases the voltage applied to the electric motor after startup at a predetermined speed to the first applied voltage, searches for a voltage at which the voltage applied to the electric motor stabilizes at the target airflow rate after reaching the first applied voltage, and stores the voltage at which the target airflow rate stabilizes as the second applied voltage in the storage unit. The first applied voltage corresponds to the initial voltage described in, for example, one embodiment of the present invention, and the second applied voltage corresponds to the storage voltage described in, for example, one embodiment of the present invention.

[0010] Furthermore, in the range hood of the present invention, the control unit searches for a voltage that stabilizes at the target airflow within a first time range, and if it detects a voltage that stabilizes at the target airflow within a second time range shorter than the first time range, it stores the voltage as the second applied voltage in the storage unit. The first time range corresponds to, for example, the first specified time range described in one embodiment of the present invention, and the second time range corresponds to, for example, the second specified time range described in one embodiment of the present invention.

[0011] Furthermore, in the range hood of the present invention, if the control unit does not detect a voltage that stabilizes at the target airflow rate during the second time period, it stores the voltage at the end of the first time period as the second applied voltage in the storage unit.

[0012] Furthermore, the range hood of the present invention allows for a change from a first target airflow to a second target airflow, and the control unit, when the storage unit stores a second applied voltage corresponding to the second target airflow, changes the applied voltage to the electric motor after the target airflow change at a predetermined speed to the second applied voltage corresponding to the second target airflow, and when the storage unit does not store a second applied voltage corresponding to the second target airflow, changes the applied voltage to the electric motor after the target airflow change at a predetermined speed to a third applied voltage obtained by adding a predetermined offset voltage to the applied voltage at the time the change operation to the second target airflow was performed. The first target airflow corresponds to any one of the airflow (small), airflow (medium), and airflow (large) described in, for example, one embodiment of the present invention, and the second target airflow corresponds to any one of the airflow (small), airflow (medium), and airflow (large) described in, for example, one embodiment of the present invention, that is different from the first target airflow. Furthermore, the offset voltage corresponds to, for example, the airflow difference offset voltage described in one embodiment of the present invention, and the third applied voltage corresponds to, for example, the target voltage of the airflow transition control process when the target airflow increases, or the target voltage of the airflow transition control process when the target airflow decreases, described in one embodiment of the present invention.

[0013] Furthermore, the range hood of the present invention is characterized in that the control unit sets the offset value to a positive voltage when the second target airflow is greater than the first target airflow, and sets the offset value to a negative voltage when the second target airflow is less than the first target airflow.

[0014] Furthermore, in the range hood of the present invention, when the control unit increases the voltage applied to the electric motor after startup at a predetermined speed to the first or second applied voltage, it increases the applied voltage at the first speed, and then increases the applied voltage at a second speed greater than the first speed. The first speed corresponds to the rate at which the applied voltage increases in the voltage application control C1 described as one embodiment of the present invention, and the second speed corresponds to the rate at which the applied voltage increases in the voltage application control C2 described as one embodiment of the present invention. [Effects of the Invention]

[0015] The range hood of this invention makes it possible to accurately and quickly achieve a constant airflow in response to changes in the static pressure of the piping.

[0016] Furthermore, the range hood of the present invention can accurately and quickly detect the voltage at which the target airflow rate stabilizes within a first time range, and in subsequent startups, it is possible to achieve a constant airflow rate even more quickly in response to changes in the static pressure of the piping.

[0017] Furthermore, the range hood of the present invention can accurately detect the voltage at which the target airflow rate stabilizes without exceeding the first time range, and can achieve a constant airflow rate even more quickly in response to changes in the static pressure of the piping during subsequent startups.

[0018] Furthermore, the range hood of the present invention enables airflow control that provides superior user experience when the target airflow volume is changed.

[0019] In addition, in the range hood of the present invention, when the change in the target air volume increases the air volume, it is possible to realize an air volume change control with excellent usability, and when the change in the target air volume decreases the air volume, it is also possible to realize an air volume change control with excellent usability.

[0020] In addition, in the range hood of the present invention, while suppressing the startup sound of the electric motor at startup, it is possible to more promptly realize a constant air volume in response to changes in the piping static pressure.

Brief Description of the Drawings

[0021] [Figure 1] It is a cross-sectional view for explaining a range hood which is an embodiment of the present invention. [Figure 2] It is a diagram showing the hardware configuration related to the electric motor control of a range hood which is an embodiment of the present invention. [Figure 3] It is a diagram showing a graph for explaining the relationship between the applied voltage and time in the control of the applied voltage to an electric motor which is an embodiment of the present invention. [Figure 4] It is a diagram showing a graph for explaining the relationship between the applied voltage and time in the control of the applied voltage to an electric motor which is an embodiment of the present invention. [Figure 5] It is a diagram showing a table for explaining the applied voltage stored in the storage unit in the initial state of a range hood which is an embodiment of the present invention. [Figure 6] It is a diagram showing a table for explaining the applied voltage stored in the storage unit in the operating state after startup of a range hood which is an embodiment of the present invention. [Figure 7] It is a diagram showing a flowchart for explaining the startup control process executed by the control unit which is an embodiment of the present invention. [Figure 8] It is a diagram showing a flowchart for explaining the air volume constant control process executed by the control unit which is an embodiment of the present invention. [Figure 9] It is a diagram showing a table for explaining the calculation of the target current value which is an embodiment of the present invention. [Figure 10]This diagram shows a flowchart illustrating the airflow transition control process performed by a control unit, which is one embodiment of the present invention, when the target airflow increases. [Figure 11] This diagram shows a flowchart illustrating the airflow transition control process performed by a control unit, which is one embodiment of the present invention, when the target airflow decreases. [Figure 12] This figure shows a table illustrating the calculation of the airflow difference offset voltage when switching airflow, which is one embodiment of the present invention. [Modes for carrying out the invention]

[0022] Hereinafter, a range hood 10 according to one embodiment of the present invention will be described in detail with reference to Figures 1 to 12. In the following description of this embodiment, the same reference numeral will be used for the same components in principle, and repeated explanations will be omitted. The vertical direction indicates the height direction of the range hood 10, the horizontal direction indicates the width direction of the range hood 10, and the front-to-back direction indicates the depth direction of the range hood 10. The left-to-right direction of the paper coincides with the radial direction of the rotation axis of the blower 17, and the front-to-back direction of the paper coincides with the thrust direction of the rotation axis of the blower 17.

[0023] Figure 1 is a cross-sectional view illustrating the range hood 10, showing the cross-section in the depth direction of the range hood 10 through the electric motor 19 provided by the range hood 10. As shown in Figure 1, the range hood 10 of this embodiment mainly comprises a thin hood body 11, a blower box 12, a blower unit 13, a smoke exhaust pipe 14, a plate-shaped rectifier plate 15, a control unit 100, and a user interface 40. The blower box 12 is disposed on the upper surface of the hood body 11. The blower unit 13 and the control unit 100 are disposed inside the blower box 12. The control unit 100 may be provided in a gap within the range hood 10 that does not obstruct airflow, not limited to the blower box 12, or it may be provided separately from the range hood 10 or integrated with the cooking surface. The smoke exhaust pipe 14 communicates with the blower box 12. The plate-shaped rectifier plate 15 is positioned below the hood body 11. The user interface 40 is positioned on the front side of the hood body 11. A filter 12B is positioned near the opening 12A of the blower box 12. The filter 12B is held in place by a structure that engages with a locking part (not shown), making it easy to attach to and detach from the blower box 12.

[0024] The range hood 10 is fixedly installed against a wall (not shown) above a cooking surface (not shown). The range hood 10 operates the blower 17 of the blower unit 13 to capture air containing oil fumes, water vapor, etc., that rises from the cooking surface during cooking, and discharges it outdoors through the exhaust pipe 14.

[0025] The hood body 11 is a thin, box-shaped body, with a large opening 11A formed on its bottom side. Below the hood body 11, a plate-shaped rectifier plate 15 is attached so as to cover most of the opening 11A. An annular gap 16 is formed between the hood body 11 and the plate-shaped rectifier plate 15, along the outer edge of the plate-shaped rectifier plate 15.

[0026] The hood body 11 utilizes the airflow generated by the blower 17, which constitutes the blower unit 13, to draw in the air containing oil fumes and other substances rising from the cooking surface through the gap 16 into the range hood 10. At this time, the gap 16 is a narrower opening area than the opening 11A of the hood body 11, which strengthens the force of the airflow generated by the blower 17, causing the air containing oil fumes and other substances to be forcefully drawn into the range hood 10.

[0027] The blower box 12 is a box-shaped body that houses the blower unit 13 inside. The blower box 12 is screw-fixed to the top surface of the hood body 11 so as to communicate with the hood body 11. A smoke exhaust pipe 14 is provided on the top panel of the blower box 12. The smoke exhaust pipe 14 communicates with the blower unit 13, which is installed inside the blower box 12, via a connection port 18.

[0028] The blower unit 13 mainly comprises a blower 17, an electric motor 19 that serves as the driving source for the blower 17, and a blower housing 20 that supports the blower 17 and the electric motor 19. The blower unit 13 also has a cylindrical rectifier plate placed at the air intake of the blower housing 20.

[0029] The blower 17 can be a centrifugal blower, an axial flow blower, a mixed flow blower, or the like. In this embodiment, for example, a sirocco fan, which is a type of centrifugal blower, is used. Alternatively, a limit load fan, which is also a type of centrifugal blower, may be used.

[0030] The blower housing 20 is fixed with screws to the top panel inside the blower box 12. The blower housing 20 forms an air passage for flowing air containing the oil mist, etc., around the outer periphery of the blower 17. This air passage communicates with the smoke exhaust pipe 14 via a connection port 18 on the top panel of the blower box 12.

[0031] Furthermore, the electric motor 19 is fixed to the blower housing 20 of the blower box 12. The blower 17 rotates via the electric motor 19, drawing in air containing oil fumes and the like into the range hood 10 and blowing the air containing oil fumes and the like outwards via the exhaust pipe 14 or the like. The electric motor 19 can be controlled by the control unit 100, and for example, a DC brushless motor is used.

[0032] Specifically, as indicated by arrow 25, the air containing the oil fumes, etc., flows into the range hood 10 through the gap 16 between the hood body 11 and the plate-shaped rectifier plate 15. Next, the air containing the oil fumes, etc., flows into the blower box 12 through the opening 12A of the blower box 12. Next, the air containing the oil fumes, etc., flows into the blower 17 through the intake port formed on the front of the blower housing 20. After that, as indicated by arrow 22, the air containing the oil fumes, etc., is blown out by the blower 17 into the air passage of the blower housing 20, flows into the smoke exhaust pipe 14, and is discharged outdoors.

[0033] The control unit 100 is housed in an empty space within the range hood 10 that does not obstruct the airflow path. For example, the control unit 100 is installed alongside the blower unit 13. The user interface 40 is located on the front side of the hood body 11. The control unit 100 controls the electric motor 19 based on the operation information received from the user interface 40. The user interface 40 includes an input interface for receiving operator input and an output interface for guiding the operator through the operation.

[0034] As shown in Figure 2, the input interface includes an airflow selection switch that allows selection of the airflow rate. The input interface may also include a lighting switch that accepts on and off operations for lighting (not shown). The output interface allows the operating status of the range hood 10 to be displayed using a display device such as an LED (Light Emitting Diode), LCD (Liquid Crystal Display), or OEL (Organic Electro Luminescence).

[0035] Figure 2 shows the hardware configuration for controlling the electric motor of the range hood 10 in this embodiment. The electric motor 19 and user interface 40 of the range hood 10 are controlled by a control unit 100. The control unit 100 includes a control unit 101, a storage unit 102, a current sensor 103, and a pulse sensor 104.

[0036] The control unit 101 controls the electric motor 19 based on the information detected by the current sensor 103, the information detected by the pulse sensor 104, the information input from the user interface 40, and the information stored in the memory unit 102. The control unit 101 also outputs necessary information to the user interface 40 based on the information input from the user interface 40 and various control information, informing the operator of the operation acceptance status and operating status of the range hood 10.

[0037] The control unit 101 is implemented by the processor executing a program. The processor is connected via a bus to the current sensor 103, pulse sensor 104, user interface 40, and memory unit 102. The control unit 101 is, for example, a CPU (Central Processing Unit), MPU (Micro Processing Unit), or DSP (Digital Signal Processor). The control unit 101 may also be implemented using electronic circuits such as an ASIC (Application Specific Integrated Circuit) or PLD (Programmable Logic Device).

[0038] The memory unit 102 is used as the main memory of the control unit 100. The memory unit 102 stores programs to be executed by the control unit 101. The memory unit 102 also stores various data used for processing by the processor and various data used for controlling the electric motor 19. The memory unit 102 includes, for example, RAM (Random Access Memory) as volatile memory and ROM (Read Only Memory) as non-volatile memory. The memory unit 102 is also capable of retaining various rewritable data even when the power is cut off. The memory unit 102 can retain various rewritable data even when the power is cut off by, for example, battery backup using a battery or supercapacitor, or by using non-volatile memory such as EEPROM (Electrically Erasable Programmable ROM). The memory unit 102 may be capable of initializing the data by cutting off the backed-up power supply, or by inputting a reset switch. The current sensor 103 is a sensor that measures the drive current of the electric motor 19. The pulse sensor 104 is a sensor that measures the pulse output associated with the rotation of the electric motor 19.

[0039] The range hood 10 can realize the processing functions of this embodiment with the hardware configuration described above. The program executed by the control unit 100 can be stored on various recording media. For example, the program executed by the control unit 100 can be stored on a portable recording media such as a memory device or memory card (not shown). The program stored on the portable recording media may be installed in the storage unit 102 under control from the control unit 101 and then become executable.

[0040] Next, the relationship between applied voltage and time in the control of the voltage applied to the electric motor 19 by the control unit 100 will be explained using the graphs shown in Figures 3 and 4. The memory unit 102 can store and retain the first applied voltage V1 and the second applied voltage V2. The graph shown in Figure 3 corresponds to the case when the memory unit 102 does not store and retain the second applied voltage V2, and the graph shown in Figure 4 corresponds to the case when the memory unit 102 stores and retains the second applied voltage V2. The first applied voltage V1 and the second applied voltage V2 are the target applied voltages for the electric motor 19 after startup. The first applied voltage V1 is a voltage that is stored in advance by the memory unit 102 and is information that is not updated or erased under the operating environment of the range hood 10. The second applied voltage V2 is a voltage that is made available for storage and retention by the memory unit 102 and is information that may be updated or erased under the operating environment of the range hood 10. When the memory unit 102 does not store the second applied voltage V2, i.e., in a new operating environment, the control unit 100 uses the first applied voltage V1 to control the voltage applied to the electric motor 19. After control using the first applied voltage V1, the control unit 100 stores the stable applied voltage to the electric motor 19 as the second applied voltage V2 in the memory unit 102. When the memory unit 102 stores the second applied voltage V2, the control unit 100 uses the second applied voltage V2 as a voltage that has a proven track record of stability in a known operating environment to control the voltage applied to the electric motor 19.

[0041] First, the control of the voltage applied to the electric motor 19 when the memory unit 102 does not store the second applied voltage V2 will be explained using the graph shown in Figure 3. First, the case in which the user interface 40 receives an operation command for the target airflow (small) will be explained. At timing t0, the control unit 101 starts voltage application control C1 from the applied voltage "0", and proceeds through voltage application control C2, voltage application control C3, voltage application control C4 to voltage application control C5.

[0042] Voltage application control C1 and voltage application control C2 are responsible for startup control from the applied voltage "0" up to the initial voltage Vl0. The initial voltage Vl0 corresponds to the first applied voltage V1 stored in the memory unit 102. Voltage application control C1 is responsible for the control that precedes the initial startup. The applied voltage is increased at a predetermined rate until the timing t1 becomes the applied voltage Vs. The rate at which the applied voltage increases in voltage application control C1 is a predetermined speed within a range where a discrepancy between the applied voltage and the rotational speed immediately after startup is unlikely to occur, and is smaller than that of voltage application control C2. As a result, the range hood 10 suppresses the discrepancy between the applied voltage immediately after startup and the rotational speed of the electric motor 19. In addition, the range hood 10 suppresses the startup noise of the electric motor 19 during startup. The timing t1 for the applied voltage Vs can be a timing based on the rotation detection of the electric motor 19. The timing t1 for the applied voltage Vs may be a predetermined timing for the applied voltage Vs or a predetermined timing.

[0043] Voltage application control C2 is responsible for the subsequent control in the startup control, taking over from voltage application control C1. Voltage application control C2 increases the applied voltage at a predetermined rate until the timing t2 reaches the initial voltage Vl0. The rate at which the applied voltage increases in voltage application control C2 is predetermined to increase within a range where a discrepancy between the applied voltage and the rotational speed is unlikely to occur, and is greater than that of voltage application control C1. As a result, the range hood 10 speeds up the time it takes for the electric motor 19 to reach the initial voltage Vl0.

[0044] Voltage application controls C3, C4, and C5 are responsible for constant airflow control after the initial voltage Vl0 is reached. Voltage application control C3 is responsible for the adjustment process of adjusting the applied voltage to correspond to the low airflow at the static pressure in the operating environment of the range hood 10. Voltage application control C3 is responsible for the period from timing t2 when the initial voltage Vl0 is reached to timing t5 when the constant control voltage Vlx is reached, at which point the airflow can be considered constant. Note that when voltage application control C3 is executed, the constant control voltage Vlx is not a predetermined value and is unknown before the execution of voltage application control C3. Also, when voltage application control C3 is executed, the rate of change of the applied voltage may increase or decrease, and the amount of change is not fixed in advance.

[0045] Voltage application control C4 is responsible for the stability determination process of the constant airflow control, which determines the stability of the applied voltage corresponding to the low airflow based on the static pressure in the operating environment of the range hood 10. Here, the stability determination of the applied voltage corresponds to the determination of the set airflow. The constant control voltage Vlx is a provisional value of the constant control voltage before the execution of voltage application control C4, and becomes a determined value at timing t8 after the execution of voltage application control C4. The constant control voltage Vlx, which becomes a determined value after the execution of voltage application control C4, is stored in the storage unit 102 as the stored voltage for the low airflow. The constant control voltage Vlx stored in the storage unit 102 corresponds to a second applied voltage V2 that the storage unit 102 can store.

[0046] Voltage application control C5 is responsible for the steady-state control process of constant airflow control. Until the end of operation or the airflow is changed, voltage application control C5 applies the constant control voltage Vlx determined by voltage application control C4 to the electric motor 19.

[0047] Next, we will explain the case where the user interface 40 receives an operation request for a target airflow rate (medium). The control unit 101 executes voltage application control C1 from timing t0 to timing t1, and then executes voltage application control C2 from timing t1 to timing t3, where the initial voltage Vm0 is reached. The control unit 101 executes voltage application control C3 from timing t3 to timing t6, and then proceeds through voltage application control C4 to timing t9, finally reaching voltage application control C5, where the constant control voltage Vmx determined in voltage application control C4 is applied to the electric motor 19 for steady-state operation. The constant control voltage Vmx, which is determined by the execution of voltage application control C4, is stored in the storage unit 102 as the stored voltage for the airflow rate (medium).

[0048] Next, we will explain the case where the user interface 40 receives an operation request for the target airflow rate, which is (high). The control unit 101 executes voltage application control C1 from timing t0 to timing t1, and then executes voltage application control C2 from timing t1 to timing t4, where the initial voltage Vh0 is reached. The control unit 101 executes voltage application control C3 from timing t4 to timing t7, and then proceeds through voltage application control C4 up to timing t10, finally reaching voltage application control C5, where the constant control voltage Vhx determined in voltage application control C4 is applied to the electric motor 19 for steady-state operation. The constant control voltage Vhx, which is determined by the execution of voltage application control C4, is stored in the storage unit 102 as the stored voltage for the (high) airflow rate.

[0049] Furthermore, regardless of whether the target airflow is set to (low), (medium), or (high), the rate at which the applied voltage rises in voltage application control C1 and voltage application control C2 is the same. As a result, the range hood 10 can quickly raise the applied voltage after startup to the initial voltages Vl0, Vm0, and Vh0, regardless of whether the target airflow is set to (low), (medium), or (high).

[0050] Next, the control of the voltage applied to the electric motor 19 when the memory unit 102 is storing the second applied voltage V2 will be explained using the graph shown in Figure 4. First, we will explain the case when the user interface 40 receives an operation command for the target airflow (low) airflow. At timing t0, the control unit 101 starts voltage application control C1 from the applied voltage "0", proceeds through voltage application control C2 and voltage application control C4, and then proceeds to voltage application control C5. Note that the control unit 101 may also require voltage application control C3 between voltage application control C2 and voltage application control C4.

[0051] The voltage application control C1 when the memory unit 102 stores and holds the second applied voltage V2 is the same as the voltage application control C1 when the memory unit 102 does not store and hold the second applied voltage V2.

[0052] The voltage application control C2 increases the applied voltage at a predetermined rate until the timing t11 reaches the initial voltage Vlx. The initial voltage Vlx is a value that has been proven to achieve constant airflow control in previous operations under the installation environment of the range hood 10. The initial voltage Vlx is a value that is expected to achieve constant airflow control earlier in the current operation under the installation environment of the range hood 10 than the initial voltage Vl0 (see Figure 3). Note that the initial voltage Vlx in Figure 4 is the same as the constant control voltage Vlx in Figure 3 that was stored in the memory unit 102 as a memory voltage in the previous operation of the range hood 10.

[0053] Voltage application control C3 is unlikely to be executed if the installation environment of the range hood 10 has not changed between the previous and current operation, because the adjustment process for the applied voltage corresponding to the low airflow at the static pressure in the operating environment of the range hood 10 will be the same as before. However, if the installation environment of the range hood 10 has changed between the previous and current operation, such as by opening or closing a window, voltage application control C3 may be executed as an adjustment process to adjust the applied voltage to the low airflow at the static pressure in the operating environment of the range hood 10.

[0054] The voltage application control C4 when the memory unit 102 stores and holds the second applied voltage V2 is the same as the voltage application control C4 when the memory unit 102 does not store and hold the second applied voltage V2. The initial voltage Vlx is a provisional value of the constant control voltage before the execution of the voltage application control C4, and becomes a determined value at timing t14 when the voltage application control C4 is executed. The constant control voltage is highly likely to be the same as the initial voltage Vlx if the installation environment of the range hood 10 has not changed between the previous operation and the current operation. Also, the constant control voltage may differ from the initial voltage Vlx if the installation environment of the range hood 10 has changed between the previous operation and the current operation. The constant control voltage that becomes a determined value when the voltage application control C4 is executed is stored in the memory unit 102 as the stored voltage for the airflow (low) setting.

[0055] The voltage application control C5 when the memory unit 102 stores and holds the second applied voltage V2 is the same as the voltage application control C5 when the memory unit 102 does not store and hold the second applied voltage V2.

[0056] Next, we will explain the case where the user interface 40 receives an operation request for a target airflow rate (medium). The control unit 101 executes voltage application control C1 from timing t0 to timing t1, and then executes voltage application control C2 from timing t1 to timing t12, when the initial voltage Vmx is reached. The control unit 101 executes voltage application control C4 from timing t12 to timing t15, and then proceeds to voltage application control C5, which uses the constant control voltage determined in voltage application control C4 as the applied voltage to the electric motor 19 for steady-state operation. The constant control voltage determined by the execution of voltage application control C4 is stored in the storage unit 102 as the stored voltage for the airflow rate (medium). If the installation environment of the range hood 10 has changed between the previous operation and the current operation, voltage application control C3 may be executed between voltage application control C2 and voltage application control C4.

[0057] Next, we will explain the case where the user interface 40 receives an operation request for the target airflow (high) setting. The control unit 101 executes voltage application control C1 from timing t0 to timing t1, and then executes voltage application control C2 from timing t1 to timing t13, where the initial voltage Vhx is reached. The control unit 101 executes voltage application control C4 from timing t13 to timing t16, and then proceeds to voltage application control C5, which uses the constant control voltage determined in voltage application control C4 as the applied voltage to the electric motor 19 for steady-state operation. The constant control voltage determined by the execution of voltage application control C4 is stored in the storage unit 102 as the stored voltage for the airflow (high) setting. If the installation environment of the range hood 10 has changed between the previous operation and the current operation, voltage application control C3 may be executed between voltage application control C2 and voltage application control C4.

[0058] Furthermore, regardless of whether the target airflow is set to (low), (medium), or (high), the rate at which the applied voltage rises in voltage application control C1 and voltage application control C2 is the same. As a result, the range hood 10 can quickly raise the applied voltage to the initial voltage after startup, regardless of whether the target airflow is set to (low), (medium), or (high). In particular, when the memory unit 102 stores the second applied voltage V2, the initial voltages Vlx, Vmx, and Vhx correspond to constant control voltages, so constant airflow control can be achieved even more quickly.

[0059] Next, the applied voltages stored by the memory unit 102 will be explained using Figures 5 and 6. The table shown in Figure 5 is the data stored by the memory unit 102 in the initial state of the range hood 10 in this embodiment. The initial state can be, for example, the state before the first operation of the range hood 10, the state in which the backup power supply for the stored voltage storage area has been lost, or the state in which the stored voltage storage area has been reset. The table shown in Figure 5 stores the initial voltage corresponding to the first applied voltage V1 for each of the airflow (low), airflow (medium), and airflow (high) settings, but does not store the stored voltage corresponding to the second applied voltage V2. For example, the memory unit 102 stores the initial voltage Vl0 for airflow (low), the initial voltage Vm0 for airflow (medium), and the initial voltage Vh0 for airflow (high).

[0060] The table shown in Figure 6 is the data stored by the storage unit 102 in the non-initial state of the range hood 10 in this embodiment. The non-initial state is, for example, a state in which the range hood 10 has an operating history up to timings t8, t9, and t10 in the graph shown in Figure 3. Another non-initial state is a state in which the range hood 10 has an operating history up to timings t14, t15, and t16 in the graph shown in Figure 4. The table shown in Figure 6 stores the initial voltage corresponding to the first applied voltage V1 and the stored voltage corresponding to the second applied voltage V2 for each of the airflow (low), airflow (medium), and airflow (high) settings. For example, the memory unit 102 stores the initial voltage Vl0 for low airflow, the initial voltage Vm0 for medium airflow, the initial voltage Vh0 for high airflow, the stored voltage Vlx for low airflow, the stored voltage Vmx for medium airflow, and the stored voltage Vhx for high airflow. Note that the stored voltages for low, medium, and high airflow are not necessarily stored by a single operation of the range hood 10, but require the operation history at each airflow level. Therefore, the stored voltages for low, medium, and high airflow are stored sequentially after operation at each airflow level.

[0061] Next, the startup control process performed by the control unit 101 at the start of operation will be explained using Figure 7. Figure 7 is a flowchart illustrating the startup control process performed by the control unit 101 in this embodiment. The startup control process is a process that rapidly increases the applied voltage from "0" to the target voltage.

[0062] In step S11, the control unit 101 sets the applied voltage to the electric motor 19 to "0". This timing corresponds to timing t0 in the graphs shown in Figures 3 and 4.

[0063] In step S12, the control unit 101 updates the applied voltage by adding a first increment value. The first increment value corresponds to the slope value in the voltage application control C1 of the graph shown in Figures 3 and 4, and defines the rate at which the applied voltage rises.

[0064] In step S13, the control unit 101 determines whether the applied voltage to the electric motor 19 exceeds the summation switching voltage. The summation switching voltage corresponds to the applied voltage Vs in the graphs shown in Figures 3 and 4. If the applied voltage to the electric motor 19 does not exceed the summation switching voltage, the control unit 101 proceeds to step S12, and if the applied voltage exceeds the summation switching voltage, it proceeds to step S14. The timing at which the applied voltage exceeds the summation switching voltage corresponds to timing t1 in the graphs shown in Figures 3 and 4. In other words, the voltage application control C1 is realized by the processing from step S11 to step S13.

[0065] In step S14, the control unit 101 determines whether or not a stored voltage corresponding to the specified airflow rate is stored in the storage unit 102. If the stored voltage corresponding to the specified airflow rate is not stored in the storage unit 102, the control unit 101 proceeds to step S15; if the stored voltage corresponding to the specified airflow rate is stored in the storage unit 102, it proceeds to step S16.

[0066] In step S15, the control unit 101 sets the initial voltage to the target voltage, which is the target value for the applied voltage to the electric motor 19, because the memory unit 102 does not have a memory voltage corresponding to the specified airflow rate stored therein.

[0067] In step S16, the control unit 101 sets the stored voltage to the target voltage, which is the target value for the applied voltage to the electric motor 19, since the stored voltage corresponding to the specified airflow rate is stored in the storage unit 102.

[0068] In step S17, the control unit 101 updates the applied voltage by adding a second increment value. The second increment value corresponds to the slope value in the voltage application control C2 of the graph shown in Figures 3 and 4, and defines the rate at which the applied voltage rises.

[0069] In step S18, the control unit 101 determines whether the applied voltage to the electric motor 19 exceeds the target voltage. The target voltage corresponds to the initial voltage in the graphs shown in Figures 3 and 4. For example, if the target airflow is set to low, the target voltage is the initial voltage Vl0 in the graph shown in Figure 3 and the initial voltage Vlx in the graph shown in Figure 4. If the applied voltage to the electric motor 19 has not reached the target voltage, the control unit 101 proceeds to step S17, and terminates the start control process if the applied voltage reaches the target voltage. The timing at which the applied voltage reaches the target voltage corresponds to timing t2 in the graph shown in Figure 3 or timing t11 in the graph shown in Figure 4 if the target airflow is low. Also, if the target airflow is set to medium, the timing at which the applied voltage reaches the target voltage corresponds to timing t3 in the graph shown in Figure 3 or timing t12 in the graph shown in Figure 4. The timing at which the applied voltage reaches the target voltage corresponds to timing t4 in the graph shown in Figure 3, or timing t13 in the graph shown in Figure 4, if the target airflow is set to high. In other words, the voltage application control C2 is achieved by the processing from step S14 to step S18.

[0070] Next, the constant airflow control process executed by the control unit 101 after the startup control process will be explained using Figures 8 and 9. Figure 8 is a flowchart illustrating the constant airflow control process executed by the control unit 101 in this embodiment. Figure 9 is a table illustrating the calculation of the target current value in this embodiment. The constant airflow control process is a process that searches for an applied voltage that stabilizes at a specified airflow rate over a set period of time.

[0071] In step S21, the control unit 101 clears the constant airflow flag. In other words, the control unit 101 sets the constant airflow flag to "0". The constant airflow flag is set to "0" when searching for stability of the target airflow, and to "1" when stability of the target airflow has been confirmed.

[0072] In step S22, the control unit 101 starts measuring the constant airflow control time. The constant airflow control time corresponds to a timer that limits the time required for constant airflow control so that it does not become excessive.

[0073] In step S23, the control unit 101 determines whether the constant airflow control time has exceeded the first specified time T1 and timed out. If the constant airflow control time has not timed out, the control unit 101 proceeds to step S24; if the constant airflow control time has timed out, it proceeds to step S34. The first specified time T1 is, for example, 5 minutes, but it can be shorter or longer. The first specified time T1 may be a predetermined fixed value, or it may be a variable value that can be set when the range hood 10 is installed. The first specified time T1 is common to the low, medium, and high airflow settings, but it may be a different value for each setting.

[0074] In step S24, the control unit 101 calculates the target current value for constant airflow control. The control unit 101 detects the rotational speed of the electric motor 19 from the information detected by the pulse sensor 104 and obtains the target current value from the table shown in Figure 9. For example, when the control unit 101 detects rotational speed N1, it can obtain the target current value I1. The table shown in Figure 9 is data experimentally obtained from a master motor that represents the electric motor 19, which have individual differences in performance. The table shown in Figure 9 lists the rotational speed (rpm) and target current value (A) that serve as the basis for determining the stability of constant airflow control at known static pressures (Pa). The static pressures P1 to P5 are values ​​arranged in ascending order at predetermined intervals, such as 5 Pa. The rotational speeds N1 to N5 are experimentally obtained values ​​corresponding to each of the static pressures P1 to P5 and are arranged in ascending order. The current values ​​I1 to I5 are also experimentally obtained values ​​corresponding to each of the static pressures P1 to P5 and are arranged in ascending order. Note that the table shown in Figure 9 consists of data corresponding to static pressures P1 to P5 for the sake of simplifying the drawing, but it may consist of any amount of data, such as data corresponding to static pressures P1 to P100.

[0075] In step S25, the control unit 101 obtains the measured current value, i.e., the current value of the electric motor 19, from the current sensor 103.

[0076] In step S26, the control unit 101 compares the target current value with the measured current value to determine whether the target has been acquired. The control unit 101 determines whether the target has been acquired with a predetermined margin, taking into account the variation of the electric motor 19, the measurement error of the pulse sensor 104, and the measurement error of the current sensor 103. For example, the predetermined margin can be defined by whether the difference between the target current value and the measured current value is within the tolerance, or, even if it is outside the tolerance, whether the deviation is below a predetermined number or percentage within a range of multiple occurrences. If the target has not been acquired, the control unit 101 proceeds to step S27, and if the target has been acquired, it proceeds to step S30. Continuous target acquisition means that the airflow is stable, and continuous failure to acquire the target means that the airflow is unstable.

[0077] In step S27, the control unit 101 clears the constant airflow flag. Note that if the constant airflow flag was cleared in step S21, the control unit 101 clears the constant airflow flag as a confirmation, and in step S31, described later, if the constant airflow flag is set, it clears it.

[0078] In step S28, the control unit 101 resets the airflow stabilization time. The airflow stabilization time is the time that is measured starting in step S32 (described later) and used to determine airflow stability in step S34 (described later).

[0079] In step S29, the control unit 101 performs an applied voltage change process. This process involves adding or subtracting to change the applied voltage to the electric motor 19 so that it can capture the target voltage. After performing the applied voltage change process, the control unit 101 proceeds to step S23. This allows the control unit 101 to change the applied voltage to the electric motor 19 so that the difference between the target current value and the measured current value is within the tolerance limit.

[0080] In step S30, the control unit 101 determines whether the constant airflow flag is set or not. If the constant airflow flag is not set, the control unit 101 proceeds to step S31; if the constant airflow flag is set, it proceeds to step S33.

[0081] In step S31, the control unit 101 sets the constant airflow flag. In other words, the control unit 101 sets the constant airflow flag to "1".

[0082] In step S32, the control unit 101 starts measuring the airflow stabilization time. After starting to measure the airflow stabilization time, the control unit 101 proceeds to step S23.

[0083] In step S33, the control unit 101 proceeds to step S34 if the airflow remains stable for a second specified time T2 from the start of measurement of the airflow stabilization time, and proceeds to step S23 if the airflow is stable for less than the second specified time T2. The second specified time T2 is, for example, 1 minute, but it can be shorter or longer. However, the second specified time T2 must not exceed the first specified time T1.

[0084] In step S34, the control unit 101 fixes the voltage applied to the electric motor 19 at the current applied voltage and stores the current applied voltage in the storage unit 102 as the stored voltage for that airflow. After fixing and storing the applied voltage, the control unit 101 terminates the constant airflow control process. Voltage application control C3 and voltage application control C4 are realized by the constant airflow control process. This constant airflow control process fixes and stores the applied voltage when the airflow is stable for a second specified time T2 within the first specified time T1, and when the first specified time T1 time-up without the airflow remaining stable for a second specified time T2. As a result, the range hood 10 can accurately and quickly detect the applied voltage that stabilizes at the target airflow within the range of the first specified time T1. Furthermore, the range hood 10 can achieve a constant airflow even more quickly in response to changes in piping static pressure during subsequent starts. In addition, the range hood 10 can achieve constant airflow control in response to variations between electric motors 19 products.

[0085] After the constant airflow control process is completed, the control unit 101 continues operation with the current applied voltage to the electric motor 19 until it receives an operation to change the airflow or stop operation. Voltage application control C5 is achieved by fixing the applied voltage after the constant airflow control process is completed. As a result, even if the static pressure changes due to disturbances such as opening and closing a window, the voltage applied to the electric motor 19 of the range hood 10 is fixed, thus suppressing changes in operating noise due to fluctuations in motor rotation speed.

[0086] Next, the airflow rate transition control process performed by the control unit 101 when the airflow rate is changed, specifically when the target airflow rate is increased and when the target airflow rate is decreased, will be explained using Figures 10 to 11. Figure 10 is a flowchart illustrating the airflow rate transition control process performed by the control unit 101 in this embodiment when the target airflow rate is increased. Figure 11 is a flowchart illustrating the airflow rate transition control process performed by the control unit 101 in this embodiment when the target airflow rate is decreased. Figure 12 is a table illustrating the calculation of the airflow rate difference offset voltage when the airflow rate is switched in this embodiment.

[0087] First, the airflow rate transition control process when the target airflow rate increases will be explained using Figures 10 and 12. The airflow rate transition control process when the target airflow rate increases is executed when there is a change operation that increases the airflow rate, such as from low to medium.

[0088] In step S41, the control unit 101 determines whether the memory voltage corresponding to the specified airflow rate, i.e., the airflow rate after the change operation, is stored in the memory unit 102. If the memory voltage corresponding to the specified airflow rate is stored in the memory unit 102, the control unit 101 proceeds to step S42; otherwise, it proceeds to step S43.

[0089] In step S42, the control unit 101 sets the target voltage to the stored voltage corresponding to the specified airflow rate stored in the memory unit 102. This enables the range hood 10 to change the airflow rate to one suitable for the installation environment when an operation to increase the airflow rate is performed.

[0090] In step S43, the control unit 101 adds the airflow difference offset voltage to the applied voltage at the time the target airflow change operation is performed. The airflow difference offset voltage is a voltage determined using the table shown in Figure 12, based on the airflow before and after the transition. The airflow difference offset voltage is a voltage that offsets the applied voltage at the time the target airflow change operation is performed, so that the operator can easily perceive the specific change in airflow when an airflow change operation occurs. The airflow difference offset voltage in the airflow transition control process when the target airflow is increased is a positive value. The table shown in Figure 12 specifies positive values ​​for the airflow difference offset voltage for airflow transitions that increase the airflow. For example, airflow difference offset voltage +V12, airflow difference offset voltage +V13, and airflow difference offset voltage +V23 are positive values.

[0091] In step S44, the control unit 101 updates the applied voltage to the electric motor 19 by adding a transition sum value. The transition sum value defines the rate at which the applied voltage increases.

[0092] In step S45, the control unit 101 determines whether the applied voltage to the electric motor 19 exceeds the target voltage. If the applied voltage to the electric motor 19 has not reached the target voltage, the control unit 101 proceeds to step S44, and if the applied voltage reaches the target voltage, it terminates the airflow transition control process when the target airflow increases.

[0093] The airflow difference offset voltage in the airflow transition control process when the target airflow is increased is useful when the difference between the applied voltage, which is fixed according to the current installation environment after the completion of the constant airflow control process, and the initial voltage corresponding to the specified airflow is too small or reversed. This allows the range hood 10 to suppress situations where no change in airflow is observed after the change operation, or where the change in airflow after the change operation changes in the opposite direction to the change operation. Such a range hood 10 enables airflow change control with superior usability when the change in the target airflow increases the airflow.

[0094] Next, the airflow transition control process when the target airflow decreases will be explained using Figures 11 and 12. The airflow transition control process when the target airflow decreases is executed when a change operation is performed that reduces the airflow, such as from high airflow to medium airflow.

[0095] In step S51, the control unit 101 determines whether the memory voltage corresponding to the specified airflow rate, i.e., the airflow rate after the change operation, is stored in the memory unit 102. If the memory voltage corresponding to the specified airflow rate is stored in the memory unit 102, the control unit 101 proceeds to step S52; otherwise, it proceeds to step S53.

[0096] In step S52, the control unit 101 sets the target voltage to the stored voltage corresponding to the specified airflow rate stored in the memory unit 102. This enables the range hood 10 to change the airflow rate to one suitable for the installation environment when a change operation is performed to reduce the airflow rate.

[0097] In step S53, the control unit 101 adds the airflow difference offset voltage to the applied voltage at the time the target airflow change operation is performed. Since the airflow difference offset voltage in the airflow transition control process when the target airflow decreases is a negative value, it is effectively a subtraction. The table shown in Figure 12 specifies negative values ​​for the airflow difference offset voltage for airflow transitions that decrease the airflow. For example, airflow difference offset voltage -V21, airflow difference offset voltage -V31, and airflow difference offset voltage -V32 are negative values.

[0098] In step S54, the control unit 101 updates the applied voltage to the electric motor 19 by subtracting a transition subtraction value. The transition subtraction value defines the rate at which the applied voltage decreases.

[0099] In step S55, the control unit 101 determines whether the applied voltage to the electric motor 19 has fallen below the target voltage. If the applied voltage to the electric motor 19 has not reached the target voltage, the control unit 101 proceeds to step S54, and if the applied voltage has fallen below the target voltage, it terminates the airflow transition control process when the target airflow decreases.

[0100] The airflow difference offset voltage in the airflow transition control process when the target airflow decreases is useful when the difference between the applied voltage, which is fixed according to the current installation environment after the completion of the constant airflow control process, and the initial voltage corresponding to the specified airflow is excessive, potentially causing an extreme reduction in airflow. This allows the range hood 10 to suppress situations where no change in airflow is observed after the change operation, or where the change in airflow after the change operation changes in the opposite direction to the change operation. Such a range hood 10 enables airflow change control with superior usability when the change in the target airflow reduces the airflow.

[0101] Furthermore, the control unit 101 executes constant airflow control processing after the completion of the airflow transition control processing when the target airflow increases, and after the completion of the airflow transition control processing when the target airflow decreases. As a result, the range hood 10 can perform constant airflow control according to the current installation environment even for the airflow after the change operation. As a result, the range hood 10 can fix and store the applied voltage according to the current installation environment even for the airflow after the change operation.

[0102] It should be noted that the disclosed embodiments are illustrative and not restrictive in all respects. Furthermore, the configurations of the above embodiments and modifications may be applied in combination. The scope of the present invention is indicated by the claims rather than the above description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of symbols]

[0103] 10 Range Hood 11 Hood body 11A opening 12 Blower box 12A opening 12B filter 13 Blower Unit 14 Smoke exhaust pipe 15 Plate-shaped rectifier 16 gaps 17 Blower 18 connection ports 19 Electric motor 20 Blower housing 40 User Interface 100 Control Units 101 Control Unit 102 Storage section 103 Current Sensor 104 Pulse Sensor

Claims

1. A blower driven by an electric motor, A control unit that controls the voltage applied to the electric motor, The system includes a storage unit capable of storing a first applied voltage and a second applied voltage corresponding to the target airflow rate to the electric motor, The aforementioned storage unit is The first applied voltage is stored in advance, The second applied voltage is made storeable by the control unit, The control unit, When the memory unit stores the second applied voltage, the voltage applied to the electric motor after startup is increased at a predetermined speed to the second applied voltage, and the voltage at which the applied voltage to the electric motor stabilizes at the target airflow after reaching the second applied voltage is searched for. When the memory unit does not store the second applied voltage, the voltage applied to the electric motor after startup is increased at a predetermined speed to the first applied voltage, and the voltage at which the applied voltage to the electric motor stabilizes at the target airflow after reaching the first applied voltage is searched for. A range hood characterized in that a stable voltage at the target airflow is stored in the memory unit as the second applied voltage.

2. The control unit, The search for a voltage that stabilizes at the aforementioned target airflow rate is performed within the first time range. The range hood according to claim 1, characterized in that when a voltage that stabilizes at the target airflow is detected during a second time shorter than the first time, the voltage is stored in the storage unit as the second applied voltage.

3. The control unit, The range hood according to claim 2, characterized in that if a voltage that stabilizes at the target airflow rate is not detected during the second time, the voltage at the end of the first time is stored in the storage unit as the second applied voltage.

4. It is possible to change from the first target airflow to the second target airflow, The control unit, When the memory unit stores the second applied voltage corresponding to the second target airflow, the applied voltage to the electric motor after the target airflow has been changed is changed at a predetermined speed to the second applied voltage corresponding to the second target airflow. The range hood according to claim 3, characterized in that, if the memory unit does not store the second applied voltage corresponding to the second target airflow, the applied voltage to the electric motor after the target airflow change is changed at a predetermined speed to a third applied voltage obtained by adding a predetermined offset voltage to the applied voltage at the time of the operation to change to the second target airflow.

5. The control unit, When the second target airflow is greater than the first target airflow, the offset voltage is set to a positive voltage. The range hood according to claim 4, characterized in that when the second target airflow is smaller than the first target airflow, the offset voltage is set to a negative voltage.

6. The control unit, The range hood according to any one of claims 1 to 5, characterized in that, when the voltage applied to the electric motor after startup is increased at a predetermined speed to the first applied voltage or the second applied voltage, the applied voltage is increased at the first speed first, and then the applied voltage is increased at the second speed which is greater than the first speed.

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