JPH07103147A - Output control method of diaphragm and circuit thereof - Google Patents

Abstract

PURPOSE:To provide a diaphragm pump output control method and its circuit, capable of controlling the pump output in a simple control circuit in addition to operation excellent in efficiency. CONSTITUTION:Output of a diaphragm pump 1 is controlled by A pulse generator 5 generating a pulse signal while a gate circuit 4 generates an operation control signal of an SSR 3 according to these pulse and control signals. This SSR 3 is switched by this operation control signal, and in the case where low speed operation is carried out, a driving current of AC power 2 is intermitted according to a pulse of the pulse generator 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm pump output control method and its circuit. For more details,
The present invention relates to an output control method and a circuit of a diaphragm pump that can operate at both a rated output and an output that is about half of the rated output.

[0002]

2. Description of the Related Art A diaphragm pump is composed of a vibrator connected to the diaphragm and having a permanent magnet, and an electromagnetic coil provided on the outer peripheral portion of the vibrator and driven by an AC power source. , Oscillator,
As a result, the diaphragm connected to the vibrator is reciprocated in response to the cycle of the AC power source to suck the fluid and then discharge the fluid.

In this diaphragm pump, since the pumping amount is reduced according to the water level, it is necessary to control the output of the pump.

As a conventional method for controlling the output of the diaphragm pump, a thyristor is used to control the phase shift part of each cycle of the AC power source by a phase shift control, or an intermediate tap is derived from an electromagnetic coil. Then
A method of tap switching is used to switch the taps.

[0005]

In the method based on phase shift control, it is easy to include high frequency components in the AC current that drives the pump, it is difficult to take measures against noise without lowering the pump characteristics, and the pump characteristics without lowering the pump characteristics. In order to control the output of, there is a problem that it has to be controlled using complicated circuit means.

Further, the tap switching method has a problem that it has a contact point and a mechanical failure is likely to occur.

Furthermore, in this type of diaphragm pump, it is easy to vibrate at a frequency that matches the mechanical impedance determined by the spring constant (Young's modulus) of the diaphragm, the mass of the rod, the damping factor on the pump side, etc. Although it is preferable to lower the frequency as well, in all of the conventional methods, the excitation frequency remains the frequency of the commercial AC power supply, and it is not matched with the mechanical impedance and noise is likely to occur.

The frequency matching the mechanical impedance means a frequency at which the diaphragm is easily excited, which is determined by mechanical constants such as the spring constant of the diaphragm, the mass of the rod, and the damping factor on the pump side.

The present invention solves the above-mentioned problems and provides a diaphragm pump output control method and a circuit having a simple structure and capable of operating efficiently even when the output is controlled to about 1/2. With the goal.

[0010]

The output control method for a diaphragm pump according to the present invention is an output control method for a diaphragm pump having an electromagnet that is operated by a commercial AC power supply.
It is characterized in that the output of the diaphragm pump is lowered by switching the commercial AC power supply with a pulse.

It is preferable to adjust the frequency of the pulse to a frequency that matches the mechanical impedance of the pump in order to increase the efficiency of the pump.

The output control circuit of the diaphragm pump of the present invention is an output control circuit of a diaphragm pump having an electromagnet that operates with a commercial AC power supply, and a solid state is provided at one of two terminals connected to the commercial AC power supply. A relay is connected, a gate circuit is connected to an input side of the solid state relay, a pulse generator is connected to a first input terminal of the gate circuit, and a control signal is connected to a second input terminal of the gate circuit. Is input, and the commercial AC power source is applied to the pump by switching the commercial AC power source directly or by the pulse of the pulse generator according to the control signal, and thereby controlling the output of the pump.

It is convenient for the pulse generator to be of a variable frequency type in order to match the mechanical impedance of the pump.

It is preferable that the solid-state relay is a zero-cross type from the viewpoint of reducing noise accompanying output switching.

[0015]

According to the present invention, when the commercial AC power supply is switched by the pulse when the low speed operation for reducing the output of the pump is performed, the excitation frequency of the diaphragm during the low speed operation can be changed by the pulse frequency. It is possible to excite the diaphragm at a frequency that matches the mechanical impedance that was in operation. As a result, the efficiency of the pump is improved, the efficiency of power consumption versus the discharge amount is increased, and the pulsation of the discharge amount is small even if the excitation frequency of the diaphragm is lowered. Further, by matching with the mechanical impedance, the high frequency component of the noise generated by the vibration of the diaphragm is reduced, and the operation becomes quiet.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An output control method for a diaphragm pump and a circuit thereof according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of an output control circuit of a diaphragm pump of the present invention.

In FIG. 1, reference numeral 1 is a movable magnet diaphragm air pump (hereinafter referred to as a pump), and one input terminal 1a for driving current is 100 V, 50 Hz or 60 Hz.
Is connected to one terminal 2b of the commercial AC power supply (hereinafter referred to as AC power supply) 2 and the other input terminal 1b of the driving current of the pump 1 is connected to the output terminals 3a and 3b of the solid state relay (hereinafter referred to as SSR) 3. It is connected to the other terminal 2a of the AC power supply 2 through. The positive terminal of the DC power supply 6 is connected to one input side terminal 3c of the SSR3,
The output of the gate circuit 4 is input to the other input terminal 3d of R3, and when the output of the gate circuit 4 is positive, SS
When R3 is turned off, the power from the AC power supply 2 is cut off, and the output of the gate circuit 4 is minus (0), SS
R is turned on, and the power of the AC power supply 2 is applied to the pump 1. A pulse signal from the pulse generator 5 is input to one input terminal 4a of the gate circuit 4, and the other input terminal 4b of the gate circuit 4 drives the pump at a rated output or a low speed of about 1/2. When a control signal indicating whether the operation is performed is input, and when the operation is performed at the rated output, the gate circuit 4 outputs a negative (0) signal, the SSR3 is turned on, and the AC signal is output.
When the electric power of the power source 2 is applied to the pump 1 and a low speed operation is performed, a pulse signal is applied to the input terminal 3d of the SSR3, and when the pulse is positive, the SSR3 is turned off,
When the pulse is minus (0), the SSR 3 is turned on, the power of the AC power source 2 is applied to the pump 1 in a pulsed manner, and the low speed operation is performed. A power supply voltage is supplied to each of the pulse generator 5 and the gate circuit 4 from a DC power supply 6. In the present embodiment, the AC power supply 2 is connected to the DC power supply 6, and the DC power supply 6 rectifies the AC voltage of the AC power supply 2 to generate the DC voltage.

The SSR 3 is preferably a zero-cross type SSR because it is less likely to generate noise. Moreover, the output switching operation must completely follow the ON and OFF signals of the input pulse.

FIG. 2 shows a circuit diagram of an example of the DC power supply of this embodiment. The primary side terminals 61a and 61b of the transformer 61 are the AC power source 2
The secondary side terminals 61c and 61d are connected to a rectifier 62 including a rectifying circuit in which four rectifying diodes are bridge-connected. The positive side output terminal of the rectifier 62 is further connected to the three-terminal regulator 63, and the negative side output terminal is connected to the ground. Smoothing capacitors C ₁ and C ₂ are respectively connected between the input and output terminals of the three-terminal regulator 63 and the ground, and both ends of the smoothing capacitor C ₂ serve as output terminals of the DC power supply 6 to supply the DC voltage Vcc. .

The DC power supply 6 is not limited to this example, and a general DC power supply such as a battery or a commercially available DC power supply can be used.

Next, an example of the pulse generator 5 and the gate circuit 4 of this embodiment will be described with reference to FIG.
The pulse generator 5 has, for example, a CR oscillation circuit composed of a resistor R ₁ and a capacitor C _3, and a pulse generation circuit composed of a blocking oscillator capable of adjusting an oscillation cycle by adjusting a bias voltage and a pulse generated by the pulse generation circuit. The frequency dividing circuit divides the signal into a pulse signal having a desired period and a frequency dividing circuit. The voltage converter Rv converts the output voltage Vcc of the DC power supply 6 shown in FIG.
_2, R _3, R ₄₎ separated by and converts into a desired DC voltage, the fundamental frequency adjusting voltage. Accordingly, by adjusting the period of the pulse signal, the excitation frequency of the diaphragm can be lowered to a frequency that matches the mechanical impedance of the diaphragm pump.

The gate circuit 4 has a structure in which two NAND circuits 41 and 42 are connected in series. Two input terminals of the NAND circuit 41 become the input terminals 4a and 4b of the gate circuit 4,
The pulse signal and the control signal of the pulse generator 5 are input to the respective input terminals. The output of the NAND circuit 41 is
It is input to the NAND circuit 42, and the output of the NAND circuit 42 is output from the output terminal 4c of the gate circuit 4.

Next, the operation of the gate circuit 4 will be described. In FIG. 4A, when the control signal is H (the output is about 1
4 (b) is the case where the control signal is L (rated operation), and the waveform of the control signal, the waveform of the pulse signal, and the output signal of the NAND circuit 41 are shown from above, respectively. Waveforms and output signal waveforms of the gate circuit 4 are shown. In FIG. 4A, when the control signal is H, the output of the NAND circuit 41 becomes a signal obtained by inverting the pulse signal, this signal is further inverted by the NAND circuit 42, and the output of the gate circuit 4 is the same as the pulse signal. Become a signal. In addition, FIG.
In, when the control signal is L, the output of the NAND circuit 41 becomes H, which is inverted by the NAND circuit 42, and the output of the gate circuit 4 becomes L.

Therefore, when an L control signal is input to the input terminal 4b of the gate circuit 4 (rated operation), the output of the gate circuit 4 is always an L output signal to the output terminal 4c. This output signal becomes the operation control signal of the SSR3. When an L signal is input from the gate circuit 4 to the input terminal 3d of the SSR3, the terminals 3a and 3b of the SSR3 are always O.
N. Therefore, the driving current is constantly supplied to the pump 1 from the AC power source 2 via the SSR 3, and the pump 1
Is operated continuously. Therefore, the output becomes the rated output.

On the other hand, when the H control signal is input to the input terminal 4b of the gate circuit 4 (low speed operation), the output of the gate circuit 4 is a pulse signal having the same cycle as the pulse signal is output to the output terminal 4c. . This output signal becomes the operation control signal of the SSR3. The gate circuit 4 is connected to the input terminal 3d of the SSR3.
When the pulse signal is input from SSR3, the SSR3 is turned on when the pulse signal is L and turned off when the pulse signal is H. Therefore, when the SSR 3 is ON, the pump 1 has the AC power supply 2
More drive current is supplied, and it is not supplied when it is OFF. As a result, the pump 1 is intermittently driven periodically, and its output is reduced as compared with the rated output during continuous driving. The output of the pump 1 can be controlled even if the ratio of the ON time and the OFF time of the pulse signal is not necessarily 1. Even if the ON time and the OFF time are not the same, the output of the pump 1 is 1 / of the rated output by the ON / OFF control of a specific cycle.
It becomes possible to control to 2.

During low speed operation, the diaphragm of the pump 1 periodically oscillates in synchronization with the pulse signal. Therefore, the diaphragm can be excited at a frequency matched with the mechanical impedance of the pump 1 and the diaphragm vibrates. The high-frequency component of the noise generated by is reduced, and quiet operation is possible. Further, the efficiency of power consumption vs. discharge amount is increased, and even if the vibration frequency of the diaphragm is lowered, pulsation of discharge amount is small.

In this embodiment, the gate circuit is an example in which two NAND circuits are connected in series, but the NAND circuit 42 may be another circuit such as an inverter.

Next, a more detailed description will be given with reference to specific examples. Pump 1 has a rated output of 100 liters /
Minute (0.15 kgf / cm ² ) diaphragm type air pump is used, AC power supply 2 uses single phase 100 V, 60 Hz power supply, and control signal turns ON / OFF the output voltage of the DC power supply via a toggle switch. Caused by.

The pulse of the pulse generator 5 is turned on for 12 milliseconds,
The characteristics of the pump 1 as a 12-millisecond OFF pulse were measured by the following procedure using the measuring device shown in FIG. 5, and the results are shown in FIG. 6A is a graph of rated operation, and B is
Is a graph of low speed operation. That is, a digital manometer 12 and a float type flow meter 13 are connected to the output port of the pump 1 by a hose 15, and a power meter 14 is connected between the AC power supply 2 and the control circuit 11 of the pump 1.

The measurement method is as follows. First, the control signal is set to L, and (a)
After operating pump 1 at the rated speed, digital manometer 12
Adjust the squeezing valve of the flow meter 13 with the flow squeezing dial 13a of the float type flow meter 13 so as to display the intended back pressure. (B) Next, the flow rate value of the flow meter 13, the back pressure value of the digital manometer 12, and the power value of the power meter 14 are recorded.
(C) Then, the control signal is set to H to switch to the low speed operation. Since the back pressure changes even if the restriction valve of the flow meter 13 is kept constant, the flow rate value of the flow meter 13, the back pressure value of the digital manometer 12, and the power value of the power meter 14 are recorded again. (D)
Return to rated operation, change the back pressure by the procedure of (a),
(B) Repeat the following procedure.

An example of the measured values thus obtained is shown in Table 1.
Shown in.

[0032]

[Table 1]

Since the flow rate of the hose 15 is the discharge rate of the pump 1, the discharge rate is the same as the flow rate.

As can be seen from the above measured values, in the low speed operation, the electric power is reduced to 50% as compared with the rated operation, while the discharge amount is 63% and the efficiency is increased by 1.26 times.

In some application examples of the diaphragm air pump, the air discharge amount does not have to be the rated value at all times as in the case of a septic tank, and the discharge amount may be limited according to external conditions. There is a case In such a case, an external condition can be detected and the signal can be input as a control signal for the pump of the present invention to construct a control system for the energy-saving pump.

When it is necessary to take noise into consideration, such as at night, the ambient brightness is detected and its signal is used. It is effective to switch to the low-speed operation operation by inputting the above signal as a control signal into the control circuit of the present invention.

Furthermore, a pressure sensor and a flow rate sensor are attached,
When monitoring back pressure and discharge rate, switching to low speed operation limits back pressure and discharge rate and facilitates sensor selection.

[0038]

According to the present invention, since the AC drive current is controlled by the pulse by the pulse generator, the gate circuit and the SSR, the output of the pump can be controlled with a simple structure and the frequency of the pulse can be controlled. The diaphragm excitation frequency can be adjusted with. As a result, it is possible to match the mechanical impedance of the pump even during low-speed operation, the high-frequency component of noise is reduced, quiet operation is possible, and the efficiency of the discharge amount with respect to power consumption is increased.

Further, the circuit structure is simple and can be formed at low cost, and since the non-contact SSR is used, the service life is long and no noise countermeasure is required. As a result, it contributes to the establishment of a high-level energy-saving system in combination with a sensor or the like, for example, automatic monitoring of the water level in the septic tank.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of an output control circuit of a diaphragm pump of the present invention.

FIG. 2 is a circuit diagram of an example of a DC power supply used in the output control circuit of the present invention.

FIG. 3 is a circuit diagram of an example of a pulse generator and a gate circuit used in the output control circuit of the present invention.

4A and 4B are diagrams showing signal waveforms of respective parts of the gate circuit of FIG. 3, where FIG. 4A is for low speed operation, and FIG. 4B is for rated operation.

FIG. 5 is an explanatory diagram of an apparatus for measuring characteristics of a diaphragm pump.

FIG. 6 is a graph showing characteristics of a diaphragm pump using the control circuit of the present invention.

[Explanation of symbols]

 1 Pump 2 AC Power Supply 3 SSR 4 Gate Circuit 5 Pulse Generator

Claims (5)

[Claims] 1. An output control method for a diaphragm pump having an electromagnet that is operated by a commercial AC power supply, wherein the output of the diaphragm pump is reduced by switching the commercial AC power supply with a pulse. Control method. 2. The output control method for a diaphragm pump according to claim 1, wherein the frequency of the pulse is adjusted to a frequency that matches the mechanical impedance of the pump. 3. An output control circuit of a diaphragm pump having an electromagnet that operates on a commercial AC power supply, wherein a solid state relay is connected to one of two terminals connected to the commercial AC power supply, and an input of the solid state relay. To the gate circuit, a pulse generator is connected to the first input terminal of the gate circuit, and a control signal is input to the second input terminal of the gate circuit, and the control signal is input in response to the control signal. An output control circuit for a diaphragm pump, in which a commercial AC power source is directly or switched by a pulse of the pulse generator and applied to the pump to control the output of the pump. 4. The output control circuit of the diaphragm pump according to claim 3, wherein the pulse generator is a frequency variable type. 5. The output control circuit for a diaphragm pump according to claim 3, wherein the solid state relay is a zero cross type.