WO2011092756A1

WO2011092756A1 - Ventilation device

Info

Publication number: WO2011092756A1
Application number: PCT/JP2010/004931
Authority: WO
Inventors: 列樹中島; 徹市川
Original assignee: パナソニック株式会社
Priority date: 2010-02-01
Filing date: 2010-08-05
Publication date: 2011-08-04
Also published as: CN102741619B; CN102741619A

Abstract

Disclosed is ventilation device wherein the air volume can be varied, and which is provided with a DC motor for driving blades, and a control circuit for controlling the DC motor. The control circuit is provided with a first current detection unit for detecting the current applied to the DC motor; a rotation speed detection unit for detecting the rotation speed of the DC motor; and a control unit for controlling the DC motor on the basis of the rotation speed detected by the rotation speed detection unit and the current detected by the first current detection unit. The current detection unit is provided with a plurality of low resistors, uses the partial voltage amounts of the low resistors to detect the motor current, and finds a ventilation air volume from the rotation speed detected by the rotation speed detection unit and the current detected by the first current detection unit.

Description

Ventilation system

The present invention relates to a ventilating apparatus that constantly ventilates a room so as to obtain a set air volume regardless of the duct length and the influence of external wind pressure.

Conventionally, this type of ventilation device includes a box-shaped ventilation fan main body 103, a motor 101 provided inside the ventilation fan main body 103, and a blade 102 driven by the motor 101. The ventilation fan main body 103 is provided on the ceiling portion 104. Further, this kind of ventilator includes a rotation speed detection unit 105 that detects the rotation speed of the motor 101, and a current detection unit 106 that detects a current flowing through the motor. Such a ventilator controls the motor 101 based on the number of rotations detected by the number-of-rotations detection unit 105 and the current detected by the current detection unit 106. Furthermore, the total ventilation air volume ventilated in a period of a predetermined cycle is determined from the rotation speed detected by the rotation speed detection unit 105 and the current detected by the current detection unit 106. The excess and deficiency of the air volume is determined by comparing the total air volume obtained and the target total ventilation air volume of the predetermined cycle, and the total ventilation air volume of the next cycle period becomes a value obtained by adding the excess and deficiency to the target total ventilation air volume. To control the ventilation air volume of the next cycle period. Such control is performed every cycle.

In such a conventional ventilating apparatus, DC motors are often used as drive motors for driving the blades, and air volumes are often set in multiple stages (for example, rapid, strong, weak). When the air volume of the ventilator is set in multiple stages, for example, the air volume control is performed with a very wide range of 100 m ³ / h to 400 m ³ / h. In order to control the air volume in a very wide range and to control the air volume so that the air volume becomes constant using the current-rotational speed flowing to the motor, it is necessary to detect the current more accurately.

JP 2004-340490 A

The present invention can accurately detect the current flowing to the motor, and thus provides a ventilation device that can keep the air volume constant even if the ventilation device has a very wide range of air volume.

The ventilating apparatus of the present invention is a ventilating apparatus that can change the air volume, and includes a DC motor that drives blades and a control circuit that controls the DC motor. The control circuit includes a first current detection unit that detects a current flowing through the DC motor, a rotation speed detection unit that detects the rotation speed of the DC motor, and a rotation speed and a first current detection unit that are detected by the rotation speed detection unit. And a controller configured to control the DC motor based on the current detected by the controller. The first current detection unit includes a plurality of low resistances, detects a motor current using a low resistance divided voltage value, and detects the number of rotations detected by the rotation speed detection unit and the first current detection unit. It is characterized in that the ventilation air volume is obtained from the current and the current.

FIG. 1 is an attachment state diagram of a ventilating apparatus according to a first embodiment of the present invention. FIG. 2 is a mounting view showing a state in which the ventilating apparatus according to the first embodiment of the present invention is attached to a ceiling. FIG. 3 is a block diagram showing the configuration of the control circuit of the ventilator according to the first embodiment of the present invention. FIG. 4 is a configuration diagram of a current detection unit of the ventilation device according to the first embodiment of the present invention. FIG. 5 is a static pressure (Pa) -ventilated air volume (Q) characteristic curve diagram of the ventilating apparatus according to the first embodiment of the present invention. FIG. 6 is a flow chart showing the operation of the ventilation system of the first embodiment of the present invention. FIG. 7 is a block diagram of a current detection unit according to a second embodiment of the present invention. FIG. 8 is a flowchart showing the driving operation of the ventilating apparatus according to the second embodiment of the present invention. FIG. 9 is a block diagram showing the configuration of a control circuit according to a third embodiment of the present invention. FIG. 10 is a flowchart showing the driving operation of the ventilating apparatus according to the third embodiment of the present invention. FIG. 11 is an attachment diagram of a ventilator according to a fourth embodiment of the present invention. FIG. 12 is a flowchart showing the driving operation of the ventilation system of the fourth embodiment of the present invention. FIG. 13 is a configuration diagram of a current detection unit of a ventilation system according to a fifth embodiment of the present invention. FIG. 14 is a diagram showing the relationship between the current linear correction value and the current of the ventilator of the fifth embodiment of the present invention. FIG. 15 is a diagram showing a configuration in which a differential is provided for the current threshold value of the ventilator of the fifth embodiment of the present invention. FIG. 16 is a flowchart showing the driving operation of the ventilating apparatus according to the fifth embodiment of the present invention. FIG. 17 is a block diagram showing the configuration of the control circuit of the fifth embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 17.

Embodiment 1
As an example of the ventilation system of the present invention, a ventilation system provided on a ceiling in a building will be described as an example.

As shown in FIG. 1 and FIG. 2, the main body 3 of the ventilator is installed, for example, on the ceiling 2 of the room 1. Below the main body 3, a suction port 3a is provided. An adapter 4 is provided on the side surface of the main body 3, and one end of an exhaust duct 5 is connected to the adapter 4. The other end of the exhaust duct 5 is connected to an exhaust port 6 provided on a wall surface in the room. With the above configuration, the air sucked from the suction port 3 a is exhausted to the outside air from the exhaust port 6 through the exhaust duct 5.

Inside the main body 3, a blade 7 and a DC motor 8 for rotating the blade 7 are provided. The suction port 3a is provided with a louver 9 having a vent that covers the suction port 3a.

Moreover, the control circuit 10 which drives the DC motor 8 is arrange | positioned at the ceiling surface side of the main body 3 of a ventilator. The switch 11 (an integrated switch) is disposed on the wall of the room and connected to the main body 3 of the ventilator. The switch 11 is used to switch on / off the commercial power supply and to switch the fan notch by the user switching.

FIG. 3 is a block diagram showing the configuration of the control circuit 10 of the main body 3 of the ventilator. In FIG. 3, the rectifier circuit 13 is connected to the commercial power supply 12. The rectifying circuit 13 is connected to a smoothing capacitor 13 a that smoothes the voltage to a DC voltage. A voltage detection unit 14 for detecting a DC voltage and a DC motor 8 are connected in parallel to the smoothing capacitor 13a. The switching power supply circuit 15 (for example, an AC-DC converter) is further connected to the smoothing capacitor 13a.

The DC motor 8 incorporates a control circuit that controls the DC motor 8. The control circuit includes a control drive IC 8a for DC motor control and a Hall element 18b which is a position detection sensor for detecting the position of the rotor of the DC motor 8 and a drive circuit 8b for energizing the stator winding of the DC motor 8 A three-phase winding (not shown) which is a daughter winding is provided. The ground of the control drive IC 8a and the ground of the drive circuit 8b are connected in common. Therefore, the current flowing to the ground (GA) side of the DC motor 8 is the sum of the current flowing to the control drive IC 8a, that is, the DC motor driving current, and the current flowing to the three-phase winding through the driving circuit 8b, that is, the current flowing to the motor itself That is, it is a total current.

The switching power supply circuit 15 outputs a voltage (for example, +15 V) of the control drive IC 8 a and a voltage (for example, +5 V) for operating the control unit 16 (for example, a microcomputer). In the vicinity of the switching power supply circuit 15, a temperature detection unit 17 that measures the temperature of the switching power supply circuit 15 is provided. The temperature measured by the temperature detection unit 17 is input to the control unit 16. In addition, a current detection unit 18 (first current detection unit) that detects the current flowing through the DC motor 8 is provided. The current detection unit 18 detects the current flowing to the ground (GA) of the DC motor 8 and inputs the current to the control unit 16.

The control unit 16 outputs a control signal VSP to the DC motor 8 based on the current detected by the current detection unit 18. The DC motor 8 varies the applied voltage in accordance with the voltage value (motor command voltage) of the control signal VSP.

The control signal VSP is configured to output a pulse from the control unit 16, smooth the output value with the smoothing capacitor 18 a, and apply the smoothed DC voltage to the DC motor 8. The smoothing capacitor 18 a is connected to the ground (GA) of the DC motor 8. The smoothing capacitor 18 a smoothes the control signal VSP based on the potential of the ground (GA).

When the voltage of the control signal VSP is applied to the DC motor 8, the drive circuit 8b is driven by the control drive IC 8a, and a current flows in the three-phase winding. When current flows in the three-phase winding, the rotor of the DC motor 8 rotates. The rotation of the rotor is detected by, for example, the Hall element 18b. Then, the Hall element 18 b outputs an output according to the rotation of the DC motor 8 to the rotation speed detection unit 19. Thus, the rotation speed detection unit 19 can detect the rotation speed of the DC motor 8.

Further, the control unit 16 determines in advance the relationship between the current and the number of revolutions when the static pressure is varied from P0 to Pmax in the ventilation air volume, and stores it as a data table (not shown).

FIG. 4 is a diagram showing the configuration of the current detection unit 18. In FIG. 4, the current detection unit 18 is configured of a low resistance of 1.5 Ω or less. For example, two low resistors 20a are arranged in series in the ground (GA) of the DC motor 8, and one side of the low resistors 20a arranged in series is connected to the ground of the switching power supply circuit 15. Further, a first resistor 20b (low resistor) and a second resistor 20c (low resistor) are provided so as to be connectable in parallel with the low resistor 20a. The first resistor 20b or the second resistor 20c is configured to be connectable to the low resistor 20a by the first switching unit 20d or the second switching unit 20e, respectively. The resistance value of the current detection unit 18 can be switched by switching the first switching unit 20 d and the second switching unit 20 e which are low resistance switching units.

Then, the potential of the ground (GA) of the DC motor 8 is amplified by the amplifier 21 (for example, an operational amplifier).

Further, the temperature detection unit 17 is configured of, for example, a thermistor. A thermistor is one that changes its resistance when it is given heat.

Further, as shown in FIG. 3, values detected by the temperature detection unit 17, the current detection unit 18, the rotation speed detection unit 19, and the voltage detection unit 14 are input to the control unit 16 (microcomputer). A program capable of performing a series of operations is written in the control unit 16 based on the detection values of the input detection units.

That is, when the current detection unit 18 detects the current of the DC motor 8, the first switching unit 20d and the second switching unit 20e are switched as needed to detect the current. As described above, the voltage value of the control signal VSP supplied to the DC motor 8 is connected to the ground (GA) of the DC motor 8 as a reference. Therefore, if the first switching unit 20d and the second switching unit 20e are switched to connect the first resistor 20b, the resistance value of the current detection unit 18 changes from 3Ω to 1Ω. Then, the ground level of the DC motor 8 changes with respect to the ground level of the control unit 16, and the voltage value of the control signal VSP to be actually applied changes. Therefore, a program for correcting the control signal VSP is also written in the control unit 16.

The specific operation of the ventilating apparatus of the present embodiment configured as described above will be described using FIGS. 5 and 6. FIG. 5 is a static pressure (Pa) -ventilated air volume (m ³ / h) characteristic curve, and FIG. 6 is a flowchart showing the operation of the ventilator of the present embodiment.

For example, as shown in FIG. 6, when the switch 11 is operated by the ventilator user and the weak notch is set as the turning on of the commercial power supply 12 and the fan notch, the ventilator 3 is powered on and controlled. Power is applied to the circuit 10. As shown in FIG. 5, when the weak notch is set, 100 m ³ / h is selected as the air volume.

Further, as shown in FIG. 6, the temperature detected by the temperature detection unit 17 is input to the control unit 16. When the fan notch is set, in order to operate the DC motor 8 reliably, the control unit 16 is in a standby state for 3 seconds after the application of the power. Thereafter, a control signal VSP (hereinafter referred to as start-up compensation VSP) as a start-up compensation value is applied to the DC motor 8. Since there is a possibility that the DC motor 8 can not start due to a low temperature or the like, it is preferable to select a value that can operate the DC motor 8 even under a low temperature or the like.

Here, the standby state refers to a state in which the control unit 16 is left as it is without immediately driving the DC motor 8.

The reason for maintaining the DC motor 8 in the standby state for 3 seconds after applying the power is as follows. The ventilating apparatus of the present embodiment is configured to be able to directly turn on / off the commercial power source 12 by the switch 11. Therefore, when the ventilation system user turns on the ventilation system continuously as entering / turning off / on, the DC motor 8 may rotate with inertia even when the power is turned off. If the power is turned on in that state, a voltage is generated by the rotation of the motor, and a regenerative current may flow to break the element. In order to prevent this, a standby state is provided to wait for the DC motor 8 to stop completely.

When the start-up compensation VSP is input to the DC motor 8, a current flows in the three-phase winding of the DC motor 8, and the DC motor 8 rotates. The current detected by the current detection unit 18, the number of rotations detected by the rotation speed detection unit 19, and the value of the voltage detected by the voltage detection unit 14 are input to the control unit 16.

At this time, both the first switching unit 20d and the second switching unit 20e of the current detection unit 18 are open.

Next, when the value detected by the current detection unit 18 does not reach, for example, 3.0 V, the control unit 16 keeps the first switching unit 20 d and the second switching unit 20 e as they are, and then the control unit 16. The detection value of the current detection unit 18 input to the control unit 16 is compared with the data table stored in advance in the control unit 16. As a result, when it is determined that the rotation speed of the rotor of the DC motor 8 is higher than the specified rotation speed for obtaining the specified ventilation air volume, the control unit 16 raises the DUTY every three seconds. When this operation is repeated and the difference in rotational speed from the prescribed rotational speed disappears, the control unit 16 determines that the ventilation air volume is the prescribed and stops the variation of the DUTY.

Further, for example, when the duct resistance is increased due to the influence of the external wind or the like, the number of rotations is decreased and the current is increased. For example, when the value detected by the current detection unit 18 becomes 3.0 V or more as a result of the above, the first switching unit 20 d is turned on (ON). Thereby, the first resistor 20b is connected in parallel with the low resistor 20a. That is, the resistance value of the current detection unit 18 is 1Ω. If the value detected by the current detection unit 18 does not reach 3.0 V when the first switching unit 20 d is turned on, the state is maintained as it is. Then, similarly to the above, the detection value of the current detection unit 18 input to the control unit 16 is compared with the data table stored in advance in the control unit 16. When the rotational speed of the rotor of the DC motor 8 is higher or lower than the specified rotational speed, the DUTY is changed every three seconds. This is repeated, and when there is no rotational speed difference with respect to the prescribed rotational speed, the control unit 16 determines that the prescribed ventilating air flow rate has been obtained and stops the variation of the DUTY.

On the other hand, when the value detected by the current detection unit 18 becomes 3.0 V or more when the first switching unit 20 d is turned on, the second switching unit 20 e is further turned on. As a result, the second resistor 20c is connected in parallel to the low resistor 20a and the first resistor 20b. That is, the resistance value of the current detection unit 18 is 0.6Ω. Then, similarly to the above, the detection value of the current detection unit 18 input to the control unit 16 is compared with the data table stored in advance in the control unit 16. When the rotational speed of the rotor of the DC motor 8 is higher or lower than the specified rotational speed, the DUTY is changed every three seconds. This is repeated, and when there is no rotational speed difference with respect to the prescribed rotational speed, the control unit 16 determines that the prescribed ventilating air flow rate has been obtained and stops the variation of the DUTY.

As described above, the ventilation air volume is adjusted by raising and lowering the DUTY every 3 seconds. Control unit 16 includes an instruction voltage change unit 200 that corrects the voltage value of control signal VSP. As described above, when the first switching unit 20d or the second switching unit 20e is switched to connect the first resistor 20b or the second resistor 20c, the command voltage changing unit 200 controls the control signal according to the switching state. The voltage value of VSP is corrected, and a correction value is given to the DC motor 8.

The current flowing through the three-phase winding of the DC motor 8 is calculated by subtracting the current flowing through the control drive IC 8 a from the current detected by the current detection unit 18 of the DC motor 8. As shown in FIG. 4, the current flowing in the control drive IC 8 a is detected by the current detection unit 18 c, and the detected value is input to the control unit 16 via the amplifier 21. Further, since the standby current of the DC motor 8 changes linearly with the ambient temperature, the temperature correction coefficient is calculated from the temperature detected by the temperature detection unit 17 to calculate the temperature correction.

The ventilator configured as described above switches the first switching unit 20d and the second switching unit 20e according to the detected value of the current flowing through the DC motor 8. Thereby, the resistance value of the current detection unit 18 is switched, and the current detection is performed by always selecting the optimum resistance with respect to the current flowing through the DC motor. As a result, the current flowing through the DC motor can be detected accurately, so that the ventilation air volume can be kept constant even when the duct resistance changes due to the influence of the external air or the like.

Although the change of the DUTY described in the present embodiment is made to have a period of 3 seconds, the effect is the same even if the period is made shorter or made longer.

Further, although the switching threshold of the first switching unit 20d and the second switching unit 20e is set to 3.0 V, the effect is the same even when the threshold is changed.

Further, although the number of the first switching unit 20d, the second switching unit 20e, and the corresponding resistors is two, the effect is the same when adjusting by changing the number of switching units and resistors. .

Further, although the current detection method of the current detection unit 18 is configured by the low resistance switching method, the effect is the same even when using a method including an amplification factor change unit (not shown) that switches the amplification factor of the amplifier 21 It is.

Second Embodiment
A second embodiment of the present invention will be described with reference to FIGS. 7 to 8. The description of the same components as in the first embodiment will be omitted. FIG. 7 is a block diagram of a current detection unit according to a second embodiment of the present invention. FIG. 8 is a flowchart showing the driving operation of the ventilating apparatus according to the second embodiment of the present invention.

As shown in FIG. 7, the current detection unit 18 of the present embodiment includes the ground (GA) of the DC motor 8 and the switching power supply circuit 15 instead of the first switching unit 20d or the second switching unit 20e of the first embodiment. A plurality of low resistances are arranged in series between the grounds of to detect the current.

Further, as in the first embodiment, in order to detect the current flowing in the control drive IC 8a, a current detection unit 18c (second one) is provided between the power supply line (+15 V) of the switching power supply circuit 15 and the control drive IC 8a. (Current detection unit) of

In the above configuration, the operation of the ventilation system of the present embodiment will be described using the flowchart shown in FIG.

The description of the same operations as in the first embodiment will be omitted. For example, when the switch 11 is operated by the ventilator user and the weak notch is set as the turning on of the commercial power supply and the fan notch, the ventilator 3 is powered on and the control circuit 10 is energized. . As shown in FIG. 8, when the weak notch is set, 100 m ³ / h is selected as the air volume.

When the fan notch is set, the control unit 16 provides the start compensation VSP three seconds after the application of the power to operate the DC motor 8. When the start compensation VSP is applied to the DC motor 8, the current detection unit 18c that detects the current flowing to the control drive IC 8a detects the current. The detection value detected by the current detection unit 18 c is input to the control unit 16.

The control unit 16 detects a plurality of detection values detected by the current detection unit 18 that detects the current of the DC motor 8 (for example, in the case where three low resistances are connected in series as shown in FIG. The optimum detection value is selected from the current detection value, the second current detection value, and the third current detection value. The current flowing through the three-phase winding is calculated from the difference between the selected detection value and the detection value of the current detection unit 18c.

Then, the rotation speed of the rotor of the DC motor 8 is calculated by comparing the value input to the control unit 16 with the table data set in advance in the control unit 16. The comparison method and the subsequent control are the same as in the first embodiment.

The criteria for selecting an optimal detection value from a plurality of current detection values are, for example, as follows. For example, when the control unit 16 is applied with a power supply of +5 V and the control unit 16 has a resolution of 10 bits, it has the highest resolution among the plurality of detection values detected by the current detection unit 18 Choose a value.

For example, when a current of 50 mA flows through the DC motor 8, the total low resistance is 4.5Ω, and the voltage generated in each low resistance with respect to the ground of the switching power supply circuit 15 is 0.225 V, 0.15 V, It becomes 0.075V. In this case, if the amplification capacity of the amplifier 21 is, for example, 10 times, the values input to the control unit 16 are 2.25 V, 1.5 V, and 0.75 V, respectively. At this time, 2.25 V is selected as the detection value of the current detection unit 18 because 2.25 V can be the highest with respect to 5 V at full scale.

Further, when the current flowing to the DC motor 8 changes from 50 mA to 100 mA due to the influence of the external air, etc., the values inputted to the control unit 16 are 3.5 V, 3.0 V, and 1. in the same manner. It becomes 5V. In this case, 3.5 V, which can be as high as 5 V originally from the resolving power, is selected as the detection value. However, when this is applied at +5 V as the power supply of the amplifier, the amplifier may exceed the allowable range of the input value due to the characteristics of the amplifier, so that the correct value may not be output from the amplifier. Therefore, in this case, 3.0 V, which has the next highest resolving power, is selected as the detection value of the current detection unit 18.

The ventilation device configured as described above can accurately detect the current flowing through the three-phase winding of the DC motor 8, so that the ventilation air volume can be constant even when the duct resistance changes due to the influence of the external air or the like. You can keep

In addition, since the current detection unit 18 detects a plurality of current values without switching the switching device or the like, it is possible to eliminate the ground change that occurs at the time of switching and to eliminate noise and the like caused by the ground change.

In the present embodiment, the current flowing through the winding is determined by subtracting the current (drive current) detected by the current detection unit 18 c from the current flowing through the DC motor 8 detected by the current detection unit 18. . In addition, a temperature detection unit is provided in the vicinity of the DC motor 8 to detect the temperature of the DC motor 8, calculate the drive current of the DC motor 8 from the detected value, and subtract it from the detection value of the current detection unit 18 It is also possible to detect the current flowing in the Further, even if the winding current is directly detected by a current sensor or the like, the effect is equivalent.

Third Embodiment
In the first and second embodiments, the current detection is performed with high accuracy to keep the ventilation air volume constant.

In the third embodiment of the present invention, in order to maintain the ventilation air volume accurately and accurately, the history of energization of the ventilator is recognized, and an embodiment in which the influence of turning on / off of the power is less affected is shown in FIGS. It explains, referring to it. The description of the same components as in the first embodiment will be omitted.

In the ventilating apparatus according to the present embodiment, as shown in FIG. 9, the control circuit 10 stores a storage unit 22 (not shown) for storing ON / OFF of the power source, a humidity detection unit 23 for detecting humidity, and a secondary The battery 24 and the diode 201 are further provided. In the control circuit 10, when the power is turned off, the cathode side of the diode 201 is connected to the power supply (+5 V side) of the control circuit 10, and the anode side of the diode 201 is connected to the positive side of the secondary battery 24 (for example, button cell) Be done. Further, the negative side of the secondary battery 24 is connected to the ground.

Further, in order to confirm turning on / off of the commercial power supply 12, a control circuit 10 is provided with a zero cross circuit (not shown). The zero crossing circuit is a circuit that detects the passage of the zero point of the AC voltage.

In the above configuration, the operation of the ventilator will be described with reference to the flowchart shown in FIG.

For example, when the switch 11 is operated by the ventilator user and the weak notch is set as the turning on of the commercial power and the fan notch, the power of the main body 3 of the ventilator is turned on and the power is applied to the control unit 16 . When the power is applied, the zero cross is input to the control unit 16, and the control unit 16 recognizes that the power is input. The humidity detection unit 23 starts the detection of the humidity, and is input to the control unit 16. When the detection result of humidity is input to the control unit 16, control is started with reference to table data (not shown) set in advance.

As for the current of the DC motor 8 in the table data, the value when the DC motor 8 is stabilized is stored. In order to control the start compensation VSP to be applied to the DC motor 8 three seconds after the application of the power, the DC motor 8 is in a standby state for three seconds after the application of the power. The current detection unit 18 detects the current in the standby state and stores the current in the storage unit 22. Three seconds after the power is applied, the DC motor 8 starts to rotate, and the current detection unit 18 detects the current including the standby current. Therefore, a difference is subtracted from the standby current stored in the storage unit 22 to calculate the winding current. Also, the control unit 16 starts counting time starting from the time when the DC motor 8 starts to rotate, and then counts the time until the power is set to OFF and the energization to the DC motor 8 is cut off.

After that, when the switch 11 is operated by the ventilator user and the commercial power is set to off, the zero cross is not input to the control unit 16. Therefore, power is supplied from the secondary battery 24 to the control unit 16, and counting of the time when the power is turned off (ie, the shut-off time of the DC motor 8) is started.

Thereafter, when the switch 11 is operated again to turn on the commercial power supply, the control unit 16 makes the following determination.

First, when the shutoff time of the DC motor 8 has passed for 5 minutes or more after the DC motor 8 has been energized for 1 hour or more, the control unit 16 determines that there is no influence of the temperature rise of the DC motor 8 and stands by Keep the same without detecting the current of

On the other hand, if the cut-off time of DC motor 8 is extremely short (e.g., less than 5 minutes) after the passage of current to DC motor 8 for one hour or more, control unit 16 determines that the temperature rise of DC motor 8 is affected. Then, the standby current is measured again to calculate the winding current of the DC motor 8. At this time, it may be further determined whether or not the shutoff time of the DC motor 8 is less than one minute, and the standby current may be measured again only in the case of less than one minute.

The ventilator configured as described above can further detect humidity, and thus can detect the specific gravity of air, so that the influence on humidity can be eliminated. In addition, since the current flowing through the winding of the DC motor 8 can be accurately detected without providing a thermistor to specially change the change in the standby current due to the temperature rise of the DC motor 8, the duct resistance Even if it changes due to the influence of air, the ventilation air volume can be kept constant.

Embodiment 4
The fourth embodiment will be described with reference to FIGS. 11 to 12. The description of the same components as in the first embodiment will be omitted.

As shown in FIG. 11, the ventilation device of the present embodiment further includes an orifice (not shown) so that a differential pressure difference is generated inside the exhaust duct 5. The differential pressure detection unit 25 installed on the side surface of the exhaust duct 5 is installed. The HIGH side pressure inlet (not shown) of the differential pressure detection unit 25 is disposed in front of the orifice of the exhaust duct 5 and the LOW side pressure inlet (not shown) is provided behind the orifice of the exhaust duct 5. The differential pressure detection unit 25 is connected to the control circuit 10 installed in the main body 3 by a signal line (not shown).

The configuration of the differential pressure detection unit 25 uses, for example, a differential pressure sensor (50 Pa) to accurately detect a low ventilation air flow. The differential pressure sensor has a symmetrical structure in which the pressure receiving surface is a silicon diaphragm, and when the pressure is received, the diaphragm fluctuates and the electrostatic capacitance changes, so that the change of the electrostatic capacitance is electrically output.

In the above-described configuration, the operation of the ventilator will be described using the flowchart shown in FIG.

As described in the first embodiment, the ventilating apparatus is configured to be able to vary the ventilation air volume in multiple stages, particularly for a ventilating apparatus using a DC motor. In addition, when the ventilation air volume is varied, the current flowing to the DC motor is also varied naturally.

For example, in the case where 30 mA current flows using the current detection unit 18 described in the second embodiment, the current detected by the current detection unit 18 is amplified and the voltage input to the control unit 16 has a resolution Even if the optimum value of is selected, it is very difficult to control the air volume at 1.35 V because it is only 1.35 V. Therefore, in the present embodiment, the differential pressure detection unit 25 is provided, and the configuration in which the current detection unit 18 detects the current value is used in combination.

For example, when the switch 11 is operated by the ventilator user and the weak notch is set as the turning on of the commercial power and the fan notch, the power of the main body 3 of the ventilator is turned on and the power is applied to the control unit 16 . The control unit 16 detects the value of the differential pressure detection unit 25 for three seconds in the standby state after the power is applied. If the value of the differential pressure detection unit 25 is output even though the DC motor 8 is not rotating, the attachment state of the differential pressure detection unit 25 has an effect, and therefore, the control unit 16 is provided. The output voltage of the differential pressure detection unit 25 is voltage corrected by the differential pressure adjustment unit (not shown) (a zero point adjustment is performed).

Depending on the mounting state, the silicon diaphragm type differential pressure sensor adds weight to the diaphragm and outputs it as a differential pressure signal, so it is necessary to adjust the output.

Three seconds after the power is applied, the DC motor 8 starts to rotate, and the current detection unit 18 detects the current flowing through the DC motor 8, and the current is input to the control unit 16. When the current flowing through the DC motor 8 is small (for example, 30 mA or less), the value of the differential pressure detection unit 25 is used to start operation of the DC motor 8 with reference to the differential pressure data table set in advance. .

In addition, when the current flowing through the DC motor 8 becomes larger than a predetermined current (for example, 30 mA or more) when the influence of outside air or the switch 11 changes the notch from weak to rapid (for example, 30 mA or more), It changes to the data table and continues the operation of the DC motor 8.

The ventilator configured as described above can detect the differential pressure accurately even if the ventilation volume is small, but the differential pressure is detected by the differential pressure detection unit, so that the ventilation volume can be accurately detected.

Although a small ventilation air volume can be detected by the differential pressure detection unit 25, when a large air volume is detected, the differential pressure range may be swung out and undetectable. However, in the case of a large air volume, a large current flows, so the value measured by the current detection unit 18 can be used. As described above, in the case of a small air volume and in the case of a large air volume, by selecting the objects to be detected, the duct resistance changes due to the influence of external wind or the like, or the notch is changed by the ventilator user. , Can keep the ventilation air volume constant.

Fifth Embodiment
A fifth embodiment will be described with reference to FIGS. 13 to 17. The description of the same components as in the first embodiment will be omitted.

In the first embodiment, the temperature detection unit 17 for measuring the temperature of the switching power supply circuit 15 is provided in the vicinity of the switching power supply circuit 15. However, in the present embodiment, as shown in FIG. Instead, the DC motor 8 is configured to include a temperature detection unit 28 that detects the temperature of the Hall element.

The relationship between the input resistance of the Hall element (in the absence of a magnetic field and the resistance between the input terminals when the output terminal is open) and the temperature is that the resistance is quadratically curved as the temperature is higher and the temperature is lower when the temperature is low. It has a characteristic that becomes low (for example, at -40 ° C: 1800 Ω, 25 ° C: 240 Ω, 50 ° C: 100 Ω).

In addition, the control unit 16 is configured to include a storage unit 29 that stores a value for correcting the variation of the electronic component in a non-volatile storage device or the like.

For example, an EEPROM is used as the non-volatile storage device. An EEPROM is a semiconductor memory device in which data can be erased or rewritten by voltage operation.

The variation in the electronic components causes a decrease in motor current detection accuracy. Therefore, in order to improve the detection accuracy of the motor current, the microcomputer power supply that affects the detection accuracy of the motor current, and the resistors constituting the current detection unit 18 that detects the current flowing through the DC motor 8 are calibrated.

Calibration is performed as follows. First, as shown in FIG. 13, for example, a current of 100 mA is supplied between VM and G, and the first switching unit 20d and the second switching unit 20e are turned off. In this manner, the variation in the resistance value of the low resistor 20a provided as one of the resistors of the current detection unit 18 is calibrated. Next, the first switching unit 20d is turned on, and the resistance value of the first resistor 20b is similarly calibrated. Finally, the second switching unit 20e is also turned on to calibrate the resistance value of the second resistor 20c. The results of the above calibrations are sequentially stored in the storage unit 29. Hereinafter, for example, a method of converting the current value when the low resistance 20a is used will be described. As shown in FIG. 17, the control unit 16 further includes a current value calculation unit 202, and the current value calculation unit 202 compares the value stored in the storage unit 29 with the theoretical value obtained by calculation, and converts the value Figure out (For example, the theoretical value of the resistance of the low resistor 20a should be 3.0 Ω × 100 mA = 0.3 V, but the value stored in the storage unit 29 is (2.8 Ω × 100 mA =) 0.28 V In other words, the data table is referenced with a value obtained by multiplying 0.3 × 0.28 = 1.07 times the voltage corresponding to the actually measured current value to obtain the number of rotations corresponding to the current. Also in the case where the first resistor 20 b and the second resistor 20 c are connected, the current value is converted in the same manner.

Further, as described in the first embodiment, when detecting the current of the DC motor 8, the current detection unit 18 switches the first switching unit 20d and the second switching unit 20e to detect the current. In such a configuration, as shown in FIG. 14, the detected value of the current input to the control unit 16 is an AD value (analog digital value read by the microcomputer according to the open / close state of the first switching unit 20d and the second switching unit 20e. The relationship between the converted value) and the current (AD value-current) flowing through the current detection resistor occurs in three steps. Therefore, by switching the low resistance switching unit which is the first switching unit 20d or the second switching unit 20e, the result obtained in each case becomes discontinuous. Therefore, appropriate control can not be performed. That is, three current values exist in one AD value, and control can not be performed. Therefore, in the present embodiment, the current value calculation unit 202 included in the control unit 16 multiplies the raw data of the AD value by a predetermined magnification. For example, when reading the voltage value of only the low resistor 20a, the AD value is tripled, when reading the voltage value obtained by adding the

first resistor

20b, 4 times when reading the voltage value added with the second resistor 20c The current detection value which becomes non-continuous by 12 times is converted to the continuous value. This enables one-to-one correspondence between the current value and the AD value.

The above conversion formula is shown below. That is, converted value = (raw AD value) × (magnification factor k / microcomputer AD value resolution (1024)) × (theoretical value (calculation result) / resistance adjustment AD value).

Further, in the present embodiment, in order to switch a plurality of low resistances having different resistance values, as shown in FIG. 15, the current threshold is provided with a differential.

Further, the control unit 16 outputs the control signal VSP to the DC motor 8 based on the current value detected by the current detection unit 18 while confirming the response of the rotational speed from the DC motor 8. The DC motor 8 varies the applied voltage in accordance with the value of the control signal VSP. However, when the control signal VSP is output but there is no reply of the rotational speed, it is determined that the DC motor 8 has some abnormality and all switching units are stopped.

The description of the same operations as in the first embodiment will be omitted.

The temperature detected by the temperature detection unit 28 that detects the temperature of the Hall element is input to the control unit 16. The current flowing through the winding of the DC motor 8 is calculated by subtracting the current flowing through the Hall element from the current detected by the current detection unit 18 of the DC motor 8. The current flowing through the Hall element is converted from the detection value of the temperature detection unit 28. Further, since the current flowing through the winding of the DC motor 8 changes depending on the ambient temperature, the current flowing through the Hall element is determined from the temperature detected by the temperature detection unit 28 and the Hall element temperature correction unit (shown in FIG. Temperature correction is performed.

When the control signal VSP is input to the DC motor 8 as a start compensation value, a current flows in the winding of the DC motor 8 and the DC motor 8 rotates. Then, the current detected by the current detection unit 18 at this time and the rotation speed detected by the rotation speed detection unit 19 are input to the control unit 16.

Also, at this time, when the information on the rotational speed is not input to the control unit 16, it is determined that there is an abnormality, and all switching means are turned off.

When the information on the number of revolutions is input to the control unit 16, the current value calculation unit 202 sets the values actually stored in the current detection unit 18 to the values stored in the storage unit 29 according to the above-described method. A correction is made from the theoretical value to calculate a converted value.

When the conversion value from the value detected by the current detection unit 18 has not reached, for example, 3.0 V, the first switching unit 20 d and the second switching unit 20 e maintain the state as they are. Then, the control unit 16 refers to the rotation speed corresponding to the conversion value from the value detected by the current detection unit 18 from the data table and compares it with the actual rotation speed detected by the rotation speed detection unit 19. As a result of comparison, when it is determined that the rotational speed is high, the control unit 16 raises the DUTY every three seconds. If this operation is repeated and the rotational speed difference disappears, it is determined that the regulated ventilation air flow rate, and the variable of the duty is stopped.

Further, for example, when the duct resistance is increased due to the influence of the external wind or the like, the number of rotations is decreased and the current is increased. For example, when the conversion value from the value detected by the current detection unit 18 becomes 3.0 V or more as a result of the above, the first switching unit 20 d is turned on. Thereby, the first resistor 20b is connected in parallel with the low resistor 20a. That is, the resistance value of the current detection unit 18 is 1Ω. If the conversion value does not reach 3.0 V when the first switching unit 20 d is turned on, the state as it is is maintained. Then, similarly to the above, the detection value of the current detection unit 18 input to the control unit 16 is compared with the data table stored in advance in the control unit 16. When the rotational speed of the rotor of the DC motor 8 is higher or lower than the specified rotational speed, the DUTY is changed every three seconds. This is repeated, and when there is no rotational speed difference with respect to the prescribed rotational speed, the control unit 16 determines that the prescribed ventilating air flow rate has been obtained and stops the variation of the DUTY.

On the other hand, if the value detected by the current detection unit 18 exceeds 3.0 V when the first switching unit 20 d is turned on, the second switching unit 20 e is further turned on. Then, similarly to the above, the conversion value from the detection value of the current detection unit 18 input to the control unit 16 is compared with the data table stored in advance in the control unit 16. When the rotational speed of the rotor of the DC motor 8 is higher or lower than the specified rotational speed, the DUTY is changed every three seconds. This is repeated, and when there is no rotational speed difference with respect to the prescribed rotational speed, the control unit 16 determines that the prescribed ventilating air flow rate has been obtained and stops the variation of the DUTY.

As described above, the ventilation air volume is adjusted by raising and lowering the DUTY every 3 seconds.

In addition, when the second switching unit 20e is in the ON state, the influence of the external air or the like is eliminated and the static pressure is lowered, the duct resistance is eliminated, and the current flowing to the DC motor 8 is reduced. Therefore, when the conversion value from the value detected by the current detection unit 18 due to the current reduction is 2.7 V, that is, the second switching unit 20 e is turned off with a differential current threshold of 0.3 V with respect to 3.0 V. Do. In addition, even if the second switching unit 20e is turned off, if the detection value is still 3.0 V or more, the first switching unit 20d is turned off.

As described above, the ventilation air volume is adjusted by raising and lowering the DUTY every 3 seconds. Control unit 16 includes an instruction voltage change unit that corrects the voltage value of control signal VSP. As described above, when the first switching unit 20d or the second switching unit 20e is switched to connect the first resistor 20b or the second resistor 20c, the command voltage changing unit controls the control signal VSP according to the switching state. And corrects the voltage value of V.sub.0 and supplies the correction value to the DC motor 8.

The ventilator configured as described above switches the resistance value using the first switching unit 20d and the second switching unit 20e while detecting the current flowing through the DC motor 8, and always selects the optimum resistance value for the current. To perform current detection while securing the required resolution. Therefore, since the current can be detected accurately, the ventilation air volume can be kept constant even when the duct resistance changes due to the influence of the external wind or the like.

The ventilating device attached to a building according to the present invention is widely useful in products that can obtain an air volume within a predetermined time regardless of duct resistance and external wind pressure.

DESCRIPTION OF SYMBOLS 1 indoor 2 ceiling back 3 main body 4 adapter 5 exhaust duct 6 exhaust port 7 blade | wing 8 DC motor 8a drive IC for control
8b drive circuit 9 louver 10 control circuit 11 switch 12 commercial power supply 13 rectification circuit 14 voltage detection unit 15 switching power supply circuit 16 control unit 17 temperature detection unit 18 current detection unit 18c current detection unit 19 rotation speed detection unit 20a low resistance 20b REFERENCE SIGNS LIST 1 resistor 20 c second resistor 20 d first switching unit 20 e second switching unit 21 amplifier 22 storage unit 23 humidity detection unit 24 secondary battery 25 differential pressure detection unit 28 temperature detection unit 29 storage unit 200 indication voltage change unit 201 diode 202 Current value calculator

Claims

It is a ventilator that can change the air volume,
A DC motor for driving a blade, and a control circuit for controlling the DC motor,
The control circuit includes a first current detection unit that detects a current flowing through the DC motor, a rotation number detection unit that detects the rotation number of the DC motor, and a rotation number that is detected by the rotation number detection unit. A control unit that controls the DC motor based on the current detected by the current detection unit 1;
The first current detection unit includes a plurality of low resistances, and detects a motor current using a voltage division value of the low resistances.
A ventilating apparatus characterized in that a ventilation air volume is obtained from the number of rotations detected by the number of rotations detection unit and the current detected by the first current detection unit.
A low resistance switching unit for switching connection / disconnection of the plurality of low resistances;
The ventilator according to claim 1, wherein the control unit switches the low resistance switching unit based on a current detected by the first current detection unit.
The amplifier includes: an amplifier that amplifies a ground potential of the DC motor; and an amplification factor change unit that changes an amplification factor of the amplifier.
The ventilator according to claim 1, wherein the control unit switches the amplification factor change unit based on a current detected by the first current detection unit.
The ventilator according to claim 1, further comprising: a voltage detection unit that detects a voltage applied to a motor, wherein the ventilation air volume is determined based on the number of rotations, the current, and the voltage.
The current detection value of the first current detection unit, which is discontinuous by switching the resistance value of the first current detection unit by the low resistance switching unit, is calculated as a continuous value based on the ratio of each of the resistance values. The ventilator according to claim 2, further comprising a current value calculation unit.
A storage unit which stores voltage values generated at both ends of the low resistor in a state in which a specified current value is supplied to the low resistor as a stored value in association with the specified current value in a nonvolatile storage device; A DC voltage generator according to claim 5, further comprising: a current value calculation unit for obtaining the current value by comparing a voltage value generated at both ends of the low resistor during DC motor operation with the stored value stored in the storage unit. Ventilator as described.
The ventilator according to claim 2, wherein a differential is provided in a current threshold value for switching the resistance value of the first current detection unit by the low resistance switching unit.
3. The ventilator according to claim 2, further comprising an instruction voltage change unit that changes a motor instruction voltage to the DC motor when switching the resistance value of the first current detection unit by the low resistance switching unit. .
The ventilator according to claim 2, wherein when the motor is locked, all switching units of the low resistance switching unit are turned off.
A differential pressure detection unit is provided, and when the current value detected by the first current detection unit is equal to or less than a predetermined value, the ventilation air volume is determined based on the detection value of the differential pressure detection unit. The ventilator according to claim 1.
11. The ventilator according to claim 10, further comprising: a differential pressure adjustment unit that performs voltage correction on the output voltage according to the attachment state of the differential pressure detection unit.
A second current detection unit for detecting a motor drive current for driving the DC motor flowing to a control drive IC, and the DC motor drive from a total current flowing to the DC motor detected by the first current detection unit The ventilator according to claim 1, wherein the current value is calculated by subtracting the current.
The ventilator according to claim 4, further comprising: a current detection unit that detects a current flowing through a winding of the DC motor.
The ventilator according to claim 1, further comprising a temperature detection unit inside the control circuit.
The ventilator according to claim 1, further comprising a temperature detection unit inside the DC motor.
The ventilating apparatus according to claim 15, further comprising a Hall element temperature correction unit that measures the temperature inside the DC motor and corrects the temperature characteristic of a Hall element built into the motor.
The ventilator according to claim 1, further comprising a humidity measuring unit that measures the humidity around the ventilator.
The control circuit includes a storage unit for storing power on / off and a secondary battery for supplying power to the control circuit at the time of power off, and the control unit constantly monitors power on / off. The ventilator according to claim 1, characterized in that: