JP2002098088A - Blower device and driving device for fluid force-feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost blower device provided with constant air quantity performance of high accuracy. SOLUTION: This blower device is provided with a rotating speed detecting means 12 for detecting the rotating speed of a motor 5 for rotating an impeller; an arithmetic control part 10 for controlling a current applied to the motor 5; a current detecting means 13 for detecting a current applied to the motor 5; and an air quantity setting means 14 for setting the air quantity. The rotating speed of the motor 5 and the current value applied to the motor respectively detected by the rotating speed detecting means 12 and the current detecting means 13 are current-controlled to the rotating speed and current value corresponding to the value set by the air quantity setting means 14, by the arithmetic control part 10 on the basis of a relational expression of C determined by a working point based on the air quantity/rotating speed and K determined by a working point based on the square of current value/rotating speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower and a drive unit for a fluid pressure feeder including the blower.

[0002]

2. Description of the Related Art In recent years, in buildings and highly airtight and highly insulated houses, there has been a demand for energy saving and a function of controlling the air volume relating to ventilation, and in response to a request for improvement of the indoor air environment, a high performance filter for removing dust and a function for deodorizing. Blowers equipped with filters have been developed. In response to such demands, conventional air blowers use a small differential pressure sensor to control the air flow, because the air flow changes due to pressure loss due to the duct piping configuration, external air pressure, and pressure loss due to clogging of filters. Control is being performed. For residential use, fan motors have been developed using DC brushless motors of a constant air volume control type that can perform a constant operation at an indicated air volume without using an expensive fine differential pressure sensor. This type of fan motor is disclosed, for example, in JP-A-8-140390 and JP-A-8-1.
Many configurations as shown in Japanese Patent No. 52165 are adopted. In addition, an fan motor using a DC brushless motor of a constant air volume control type as disclosed in Japanese Patent Application No. 12-7838 has been proposed.

FIG. 7 shows a fan motor 50 using a DC brushless motor of a constant air volume control system disclosed in Japanese Patent Application Laid-Open No. 8-140390, and an air volume designated in advance for each ambient temperature. And fan motor 5
The required number of rotations for each applied voltage is stored in the number-of-rotations storage means 51 in order to operate 0. The ambient temperature detecting means 52 detects the ambient temperature at which the fan motor 50 is installed, detects the number of operating revolutions from the change time of the gate signal of the energization controlling means 53, and uses the detected ambient temperature and the applied voltage of the rotational speed storing means 51. The voltage applied to the DC brushless motor is changed by the switching power supply while controlling the air flow rate of the fan motor 50 while comparing with the rotation speed corresponding to.

FIG. 8 shows a fan motor 50 using a DC brushless motor 54 of a constant air volume control system disclosed in Japanese Patent Application Laid-Open No. 8-152165. The DC brushless motor 54 is driven by the current, the ventilation load is calculated from the rotation speed of the fan motor 50, and the target rotation speed for the target air volume is set. A motor that performs constant rotation control using a DC brushless motor can perform high-precision constant rotation control by performing feedback control of a speed command voltage based on rotation pulse output from a rotation speed output terminal.

Japanese Patent Application No. Hei 12-7838 discloses a technique relating to a constant air volume, which is a control of a fan motor using a DC brushless motor of a constant air volume control method. And the energizing current of the DC brushless motor detected by the current detecting means, and the current for each air volume stored in the control unit in advance.
The number of revolutions or the current is changed so as to approach the target airflow from the number of revolutions line. That is, with respect to the changing pressure loss, the current value I / the number of revolutions N / the air volume Q is focused on, and the air volume Q set by the air volume setting means is different from the current value I corresponding to the different rotation speeds of the impeller. By determining and controlling the DC brushless motor based on the determination, constant air volume is obtained.

[0006]

SUMMARY OF THE INVENTION The above-mentioned JP-A-8-1
In the method disclosed in Japanese Patent No. 40390, in which the relationship between the applied voltage and the rotation speed is corrected by the temperature correction sensor, the air flow is a value determined by the relationship between the current and the rotation speed. It is difficult to correct and absorb the variation in resistance during the manufacture of the motor winding coil, which causes the motor drive current to fluctuate and causes an error in the rotational speed. In addition, not only the wiring system becomes complicated with the installation of the temperature correction sensor, but also the capacity of the program for performing the correction and the ROM for storage increases.
It becomes difficult to set various air volumes.

Further, in the conventional fan motor 50 as disclosed in Japanese Patent Application Laid-Open No. 8-152165, various duct pressure loss paths such as a ventilation ventilation path in a building and the like, and an outside like a high-rise building. It is difficult to configure different pressure loss systems by installing various filters in buildings where the wind pressure changes greatly and in highly airtight housing so that a constant air volume can be obtained with high accuracy and low price according to different set air volume. is there. In other words, from the determination of the number of rotations under a constant current every fixed time, the installation conditions such as pressure loss conditions are estimated,
In a method of controlling the airflow by the rotation speed target by correcting the target rotation speed with respect to the set airflow, constant current control is required, and it is difficult to perform control using only simple voltage control. In addition, the load condition can be read under a fixed pressure loss such as a duct,
If there is a constantly fluctuating pressure loss such as outside wind, it is not possible to read an accurate load state, and it becomes difficult to control the constant air volume.

In the control disclosed in Japanese Patent Application No. 12-7838 based on the fact that the air flow is proportional to the ratio between the current and the rotation speed, when the air flow is set to a low value, the air flow is reduced by the current and the rotation speed. , The operation at a constant air volume becomes impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem.
The aim is to obtain an inexpensive blower with high-precision constant air volume performance, to promote the improvement of the maintainability of the blower, and to provide the high-precision constant flow performance of the fluid pressure blower including the blower. Is to obtain a driving device.

[0010]

According to one aspect of the present invention, there is provided a rotating speed detecting means for detecting a rotating speed of a motor for rotating an impeller, and a control means for controlling energization of the motor. And a current detection means for detecting a current supplied to the motor, and an air flow setting means for setting an air flow. The rotation speed detection means and the motor rotation speed detected by the current detection means and the current value to be supplied to the motor are determined by the air flow rate. The rotation speed and current value according to the set value by the setting means
A means for controlling the energization by the control means based on a relational expression between C determined by the operating point by the rotation speed and K determined by the operating point by the square of the current value / the rotation speed is adopted.

According to a second aspect of the present invention, there is provided the control means according to the first aspect, wherein the control means includes a measurement error of the current detecting means and a circuit based on the number of rotations and the current value of the motor at a constant pressure loss. Means for providing an error correction setting means for correcting and setting an error in current consumption is employed.

According to a third aspect of the present invention, there is provided a control device according to the first or second aspect of the present invention, wherein the control means in the means according to any one of the first and second aspects has a function of controlling the number of rotations of the impeller exceeding a reference with respect to a set airflow. Means for providing an abnormality determination means for determining and reporting an abnormality at the time of the current value is employed.

According to a fourth aspect of the present invention, there is provided a rotation speed detecting means for detecting a rotation speed of a motor for rotating a blade for pumping a fluid, a control means for controlling energization of the motor, A current detecting means for detecting a current flowing through the motor; and a flow rate setting means for setting a flow rate, wherein the number of rotations of the motor detected by the rotation number detecting means and the current detecting means and a current value to be supplied to the motor are determined by the flow rate setting means. The rotation speed and current value according to the set value by
A means for controlling the energization by the control means based on a relational expression between C determined by the operating point by the rotation speed and K determined by the operating point by the square of the current value / the rotation speed is adopted.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 The present embodiment shown in FIGS. 1 to 5 relates to a blower that can obtain a target air volume even under conditions with different pressure losses. Blowers are those that ventilate indoor air by venting it to the outside, ventilate it by taking in outdoor air into the room, ventilate by air supply, and ventilate by air supply and exhaust. Includes those that perform ventilation while replacing, and those that circulate indoor air. The blower of the present embodiment exemplifies a blower that sucks outdoor air through a duct 1 and blows air into the room through the duct 1 to ventilate the room for convenience of explanation (see FIG. 1). ).

The blower is composed of a blower unit 2, a filter unit 3, and a control unit 4.
The blowing unit 2 is a DC brushless motor 5 (hereinafter DC
The motor 1 is mainly composed of a fan motor 7 comprising an impeller 6 mounted on an output shaft of the motor, a filter unit 3 is connected to its suction side, and a duct 1 whose one end communicates with the inside of the room is connected to an outlet side. It is connected. The filter unit 3 is provided with a high-performance filter for removing dust in the air, a filter 8 such as a pollen removal filter and a functional filter for deodorization according to the application, and the blower unit 2 It is positioned together with the duct 1 as a pressure loss element.

The control unit 4 controls the air flow of the blower unit 2, and includes a converter unit 9 for converting an AC voltage to a DC voltage, an arithmetic control unit 10 for controlling the energization of the DC motor 5, and a DC motor 5 Drive unit 11 for driving the motor, a rotation speed detection unit 12 for detecting the rotation speed, a current detection unit 13 for detecting the current of the DC motor 5, an air flow setting unit 14 for setting the air flow, and a state output unit 15. It is composed of The arithmetic control unit 10 includes an error correction setting unit 16 and an abnormality determination unit 17 according to a program. The abnormality determination unit 17 outputs a state notification signal to the state output unit 15.

The air blow unit 2 is controlled by the control unit 4 so as to blow air at the air volume set by the air volume setting means 14 irrespective of fluctuations in pressure loss elements such as the duct 1 and the filter unit 3. The control operation of the control unit 4 is such that the current flowing through the DC motor 5 at the rotation speed of the DC motor 5 detected by the rotation speed detection means 12 is calculated from the current value at the rotation speed of the DC motor 5 detected by the current detection means 13. The energization control is performed by the arithmetic and control unit 10 to the rotation speed and the current value according to the values set by the air volume setting means 14.

The same operating point in the air volume relational expression of the blower
(With the same pressure loss), P∝N^Three・ D^Five, Q∝ND
^Three, H∝N^Two・ D^TwoThere is. In these equations, P is
The driving force of the fan motor, N is the rotation speed of the fan motor,
D is the blade diameter of the impeller, and H is the static pressure. Where Q∝N
・ D^ThreeQ / N = C ・ D^Three(C is determined by pressure loss
Number). Also, drive the fan motor
P = KT
N is K = K as a characteristic of the DC motor._T・ I was known
I have. From these two equations, P = K · T · N = K · (K_T・
I) ・ N = KK ・ K_TN · I is derived. Where P
Is the driving force of the fan motor, K is various constants, T is torque,
N is the number of revolutions, K_TIs a torque constant, and I is a current value. the above
Equation (P∝N^Three・ D^Five, P = KK_T・ N ・ I) to N^Three・
D^Five= KK_T・ N ・ I and D^Five/ KK _T= I / N^TwoWhen
expressed. The two equations calculated as above (Q / N = C · D^ThreePassing
And D^Five/ KK_T= I / N^Two), Impeller for each blower
Since the constants are set, Q / N
= C, I / N^Two= K is derived. These constants C and K are
Since it is a constant determined by the pressure loss,
From the relationship between C and K, the air flow Q
Can be estimated. For example, the function C = α · K
If it is a relation (α is a constant for convenience), Q / N = α ·
I / N^TwoAnd Q = α · I / N
Can be derived.

With respect to the air flow rate of the blower, when the pressure loss changes, the rotation speed of the impeller 6 changes at a constant current, and the current value changes at a constant rotation speed control. In addition, constant air volume cannot be obtained at a constant rotation speed. This can be explained by the static pressure air volume characteristic (hereinafter referred to as QH characteristic) of the blower shown in FIG. For the sake of clarity in FIG. 2, the impeller 6 in the constant current drive I ₁ (or I ₁ under a constant voltage control in conditions that do not change in temperature), for example, the duct 1 in the pressure loss condition D ₁ line (designated duct (It is assumed that the duct length is equivalent to 10m in pipe diameter)
, The air flow is only balanced at the intersection Q ₁ H ₁ of the QH characteristic I ₁ and the duct loss curve D ₁ . At this time, clogging of the filter 8, the pressure loss by the pressure loss factor shifts to increase line D _X increases, the air volume is the intersection point Q _X
Go to H _X, the motor rotation speed is increased to the N _X from N ₁ on Figure 2 the upper portion of the motor rotation curve I1, the air volume Q ₁
Decreases in Q _X from.

The air blower of the present embodiment is capable of controlling the air volume Q with respect to changing pressure loss, such as different duct piping conditions, selection of various filters, and constantly changing ventilation conditions such as outside air conditions.
Is determined by the current value I and the rotation speed N, and the air volume Q set by the air volume setting means 14 is determined by different current values I corresponding to different rotation speeds of the impeller 6, and based on this, Control to obtain a constant air volume. That is, when subjected only to the constant current control as described above at a set air volume Q ₁ in FIG. 2, since the result in balanced at the intersection Q _X H _X with an increase in pressure loss, QH characteristics in order to maintain the constant air volume Moreover, it is not performing control to move the intersection Q1H _m point. This will be described from the air volume rotational speed characteristics (referred to hereinafter QN characteristics) in FIG. 2 performs a control to move the intersection N _m I _m point on QN characteristics corresponding to QxHx point on QH characteristics in an increase in pressure loss That is. That is, rather than the N _X I ₁ point ends up air volume decreases, it is the converging as a target value for controlling the N _m I _m points is constant air volume intersection.

The arithmetic control unit 10 of the control unit 4
The relationship between C and K in the case of an arbitrary pressure loss is stored as shown in FIG. 2, and either the rotation speed or the current value is controlled as a control parameter in accordance with the set airflow, and the other control parameter is not used. The current detection result or the rotation speed detection result is compared with a control parameter and a calculated value based on a stored relationship, and the control parameter side is changed based on the comparison to make the air flow asymptotic to a target air volume. In the present embodiment, a case where the control parameter is the number of rotations will be described.

The relationship between C and K as shown in FIG. 3 is measured and designed in advance, and is stored and set in the arithmetic and control unit 10 as an approximate expression. This approximation formula may be one approximation formula or two or more approximation formulas. The power supply starts and the current value and the rotation speed in a stable state are read, and the arithmetic control unit 1
The air volume Q is calculated by the approximate expression stored in 0 and compared with the set air volume value. If the value of the calculated airflow is different from the set airflow, the number of revolutions is changed by driving the inverter drive unit 11 to the speed increasing side or the deceleration side, and the current value at that time is read from time to time, compared with the calculated air flow and converged. (Refer to the standard operation flow indicated by A in FIG. 4 showing the flowchart of the operation program). At this time, by providing a determination width as an asymptotic method according to the air volume accuracy and responsiveness required of the blower, or by increasing the average value, fluctuations in the rotation speed can be minimized and noise can be reduced. .

As shown in the operation flow of FIG. 4B, the error correction setting means 16 determines the measurement error of the current detection means 13 and the error of the circuit current consumption from the rotation speed and the current value of the DC motor 5 at a constant pressure loss. Etc. to set the correction,
For example, a circuit is set to an error correction mode in a production line. A constant pressure loss is applied to the blower with no duct connection or by a prescribed standard pressure jig or the like, and the blower is operated in this mode to obtain a predetermined rotation speed and a current consumption value of the fan motor 7. By correcting and setting the measurement error of the current detecting means 13 and the error of the circuit current consumption, and storing the corrected values in the arithmetic and control unit 10, the airflow accuracy can be improved.

In the error correction setting means 16, since the pressure loss is defined, the constant air volume Q1 is guaranteed under the constant rotation speed N1, so that the target value I1 at the constant rotation speed N1 is determined by the correction program. Is a method of storing the current consumption value of the DC motor 5 measured by the circuit in a non-volatile storage element or the like when the number of rotations reaches the constant rotation speed N1,
By adopting a method of storing a difference from a predefined reference current value in a nonvolatile storage element or the like, the accuracy of current measurement, that is, the accuracy of airflow can be easily improved. The error correction setting unit 16 may employ a method of correcting the detected current value by setting the resistance value of the current detection unit 13 using a semi-fixed VR or the like.

The abnormality judging means 17 is a self-diagnosis program for judging an abnormality when the rotational speed or the current value of the impeller 6 exceeds the set airflow exceeding the reference and notifying the abnormality by the state output section 15. Thus, a visual or auditory notification is made possible. It is possible to self-determine and report an installation condition of the blower that exceeds the assumed capacity, an abnormal rotation speed due to abrasion of a bearing or the like over time, an abnormal current consumption, and the like. By performing two types of abnormality determination when the rotational speed of the impeller 6 is abnormally high or abnormally low with respect to the upper limit or the lower limit of the rotational speed set from the airflow instruction value in C in the flowchart of FIG. Then, the current state of the fan motor 7 can be issued to the user as a maintenance alarm or a failure alarm.

In the air blower provided with the filter 8 and the heat exchanger, if the initial rotation speed of the impeller 6 is stored in a nonvolatile memory element or the like, the filter 8 or the heat exchanger may be clogged. Due to the increase in rotation speed due to the increase in pressure loss, clogging of the filter 8 and the heat exchanger can be detected,
A wide range of applications are possible, such as prompting the user to clean or replace. Even if the user forgets to install the filter 8 or the heat exchanger, the pressure loss is reduced, so that detection and notification can be performed in a similar manner.

In addition, as long as the general formulas for the blower and the motor are satisfied, the present invention can be applied to a blower using various motors other than the DC motor 5, and the constant air volume can be improved. In addition, since the rotation speed is used as a basic parameter for control, a rotation speed jump function for avoiding the rotation speed of the impeller 6, which is a resonance point of the device, can be easily obtained. Contrary to the present embodiment, it is also possible to control the current value as a control parameter and control the rotation speed.In this case, the current consumption under the voltage control is averaged, and the current consumption is not constant current by using as a control parameter. The air volume can be determined by simple voltage control and average current measurement during the control time.

Embodiment 2 In the present embodiment shown in FIG. 6, a drive device in which the configuration of the blower shown in Embodiment 1 with the DC motor 5 and the control unit 4 can be applied to various non-displacement type fluid pressure feeders including a blower. 18
The basic configuration is the same as that of the first embodiment. Therefore, the same portions as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof will be omitted.

As a non-volume type fluid pumping device for pumping a fluid by rotation of a blade (impeller 6), there are various devices other than the blower described in the first embodiment. A drive device corresponding to the fan motor 7 of the first embodiment is provided for a fluid such as a gas, a liquid, and powders or granules that behave substantially in the same manner as the fluid. The present embodiment relates to a driving device 18 applicable to such a non-volume type fluid pumping device.
And a control unit 4 for calculating and controlling the rotation speed of the DC motor 5 according to the flow rate of the target fluid and the current consumption thereof.

The rotation command input to the DC motor 5 is given to the terminal V _S, the DC motor 5 is rotated indicated by the inverter driving unit 11 by the flow rate setting means 19 calculation control unit 10 which corresponds to the air volume setting means 14 . The rotation speed detecting means 12 is constituted by a Hall element or the like, and a Hall element or the like for detecting the rotor position can be used as it is. The arithmetic and control unit 10 of the control unit 4 stores the relationship between C and K in the case of an arbitrary pressure loss as described in the first embodiment, and according to the set flow rate, either the rotation speed or the current value. Is controlled as a control parameter, the other current detection result or rotation speed detection result which is not set as a control parameter is compared with the control parameter and a value calculated by a stored relational expression (C = α · K), and control is performed based on this. By changing the parameter side, asymptotic to the target flow rate.

The drive unit 18 of this embodiment employs a configuration for inputting a rotational speed command input. However, control data of the rotational speed and current value, which are the core of the flow rate control function, are externally set by communication means or the like. By storing these functions, such as setting the flow rate setting input mode, etc., in a motor, it is possible to obtain a general-purpose motor for a constant flow rate whose output characteristics can be changed.

[0032]

According to the first aspect of the present invention, it is possible to obtain an inexpensive air blower having a high-accuracy constant air flow performance, which can obtain a target air flow even under conditions with different pressure losses.

According to the second aspect of the present invention, the air volume accuracy is further improved together with the effect according to the first aspect.

According to the third aspect of the present invention, it is possible to determine and report an abnormality by self-determination together with the effect according to any one of the first and second aspects, thereby improving maintainability.

According to the fourth aspect of the present invention, it is possible to obtain an inexpensive drive device for a fluid pumping device having a high accuracy and a constant flow rate performance capable of obtaining a target flow rate even under different load conditions.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a blower according to a first embodiment.

FIG. 2 is an explanatory diagram showing air volume-static pressure and air volume-revolution characteristics of the air blower according to the first embodiment.

FIG. 3 is an explanatory diagram showing a characteristic of air volume / rotation speed-current value / square of rotation speed of the air blower according to the first embodiment.

FIG. 4 is a flowchart showing an operation program of the blower according to the first embodiment.

FIG. 5 is an explanatory diagram of the flowchart in FIG. 4;

FIG. 6 is a block diagram illustrating a configuration of a driving device of a fluid pressure feeding device according to a second embodiment.

FIG. 7 is a block diagram showing a configuration of a conventional blower.

FIG. 8 is a block diagram showing a configuration of another conventional blower.

[Explanation of symbols]

5 DC motor, 6 impeller, 7 fan motor, 10 arithmetic control unit, 12 rotation speed detecting means,
13 current detection means, 14 air flow setting means, 16 error correction setting means, 17 abnormality determination means, 19 air flow setting means.

Claims (4)

[Claims] A motor for rotating the impeller; a rotation speed detector for detecting a rotation speed of the motor; a control unit for controlling energization of the motor; a current detection unit for detecting a current flowing through the motor; It has an air volume setting means to set,
The number of rotations of the motor detected by the number of rotations detecting means and the current detecting means and the current value to be supplied to the motor are converted into the number of rotations and the current value according to the set value by the air volume setting means, at the operating point based on the air volume / number of rotations. A blower in which the control means controls the energization based on a relational expression between C determined and K determined by an operating point based on the square of the current value / the number of revolutions. 2. The blower according to claim 1, wherein the control means corrects the measurement error of the current detection means, the error of the circuit current consumption, and the like based on the number of rotations of the motor and the current value at a constant pressure loss. A blower provided with an error correction setting unit that performs the correction. 3. The blower according to claim 1, wherein the control means determines an abnormality when the rotation speed or the current value of the impeller exceeds a reference with respect to the set airflow. An air blower provided with an abnormality determining means for notifying. 4. A rotational speed detecting means for detecting a rotational speed of a motor for rotating a blade for pumping a fluid, a control means for controlling energization of the motor, and a current detecting means for detecting an energizing current of the motor. A flow rate setting means for setting a flow rate, the rotation number of the motor detected by the rotation speed detection means and the current detection means and the current value to be supplied to the motor, the rotation speed and the current according to the set value by the flow rate setting means The drive of the fluid pumping device, in which the control means controls the energization based on a relational expression of C determined by the operating point based on the flow rate / rotational speed and K determined by the operating point determined by the square of the current value / rotational speed. apparatus.