JPH0121977B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a power control device for a vacuum cleaner used in general households.

Conventional configuration and problems thereof FIG. 1 is a schematic configuration diagram of a vacuum cleaner. 1 is the vacuum cleaner body, 2 is the remote control switch, and hose 3
installed at the tip of the 4 is a floor nozzle, and 5 is an exhaust port provided at the rear of the cleaner body 1. Here, when the floor nozzle 4 is brought into contact with the floor surface during the cleaning operation, there is a problem in that the floor nozzle 4 comes into close contact with the floor surface depending on the type of floor surface, increasing resistance and making the cleaning operation heavier. In addition, when the floor nozzle 4 is separated from the floor surface, that is, when no cleaning work is being performed, the input and output of the electric blower inside the vacuum cleaner body is at its maximum, which increases the power consumption of the vacuum cleaner and reduces energy conservation. From the face of it, there was always a lot of waste.

OBJECTS OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, improve operability, and provide an energy-saving power control device for a vacuum cleaner.

Structure of the Invention A power control device for a vacuum cleaner according to the present invention includes a pressure sensor disposed on the suction side of an electric blower, and a wind pressure sensor disposed on the exhaust side of the electric blower to detect air volume. an amplifier that amplifies outputs of a pressure sensor and a wind pressure sensor, respectively; a circuit that switches between an amplifier output of the pressure sensor and an amplifier output of the wind pressure sensor using a switching signal according to an amplifier output signal of the wind pressure sensor; A constant pressure/constant air volume control device that controls the electric blower according to the output of the wind pressure sensor in a predetermined air volume region using the output of the circuit, and controls the electric blower with the output of the pressure sensor in a lower air volume region. The structure is as follows.

With this configuration, during normal work, the constant pressure/constant air volume control device is operated by the amplifier output of the wind pressure sensor to control the electric blower.
When the intake air volume decreases and the wind pressure becomes low, a switching signal is used to perform control using the amplifier output of the pressure sensor. Since it is controlled in this manner, the electric blower operates under an appropriate load condition.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is an enlarged sectional view of essential parts of the vacuum cleaner of the present invention. Here, the dust and air sucked in through the hose 3 are separated by a filter 6, the dust accumulates in a dust box 7, and the air is discharged from an exhaust port 5. 8 is an electric blower. Further, 9 is a pressure sensor provided in a space surrounded by the front part of the suction port of the electric blower 8 and the rear part of the filter 6, and 10 is a wind pressure sensor provided in the air flow path at the rear part of the blower port of the electric blower. be.

FIG. 3 shows the degree of vacuum (P) vs. air volume (Q) characteristics of a vacuum cleaner controlled by the power control device of the present invention. In the figure, Q1 is the initial value of the air volume set in advance, and the air volume inside the vacuum cleaner is detected by the wind pressure sensor 10, and the air volume is controlled to always maintain Q1. However, when the floor nozzle 4 starts to come into close contact with the floor surface, it goes out of the constant air volume control area and automatically enters the constant pressure control area via the P-Q curve, and the pressure inside the vacuum cleaner 1 becomes constant. Controlled to maintain a constant pressure control area. In this way, the present vacuum cleaner normally operates in the constant air volume control range, and when the floor nozzle 4 comes into close contact with the floor surface, it is controlled to operate in the constant pressure control range, so the electric blower 8 is also controlled to operate in the constant pressure control range. It does not create a load and can operate with energy savings and low noise.

FIG. 4 is a block diagram showing one embodiment of the power control device of the present invention.

In the figure, an electric blower 8 and a bidirectional thyristor 11 are connected in series to the AC power source.
The gate terminal of the bidirectional thyristor 11 is connected to the emitter terminal of the transistor 12, and the collector terminal is connected to a DC power supply via a low resistor 13. Further, the output of the wind pressure sensor 10 is amplified by an amplifier 14 and connected to an input terminal of an analog multiplexer 16. Similarly, the output of the pressure sensor 9 is also amplified by the amplifier 15, and the output of the pressure sensor 9 is amplified by the analog multiplexer 1.
is connected to the other input terminal of 6. moreover,
The output of the comparator 17 is connected to the input switching terminal of the analog multiplexer 16, the reference power supply 18 is connected to the non-inverting terminal of the comparator 17, and the output of the amplifier 14 of the wind pressure sensor 10 is added to the inverting terminal. There is. Furthermore, analog multiplexer 16
The output is applied to the inverting terminal of the comparator 19, and the triangular wave 20 synchronized with the AC power supply is applied to the non-inverting terminal.The output is differentiated by a capacitor 21 and a resistor 22, and is applied to the base of the transistor 12. It is given. Resistor 23 is transistor 12
This is a stabilizing resistor. The circuit from the comparator 19 to the bidirectional thyristor 11 constitutes a constant pressure/constant air volume control device.

In the above circuit configuration, the characteristics of the amplifier 14 output of the wind pressure sensor 10 in FIG. 4A and the amplifier 15 output of the pressure sensor 9 in FIG. 4B are shown in FIG.
It is shown in FIG. In FIG. 5, when the air volume increases, the output of the amplifier 14 of the wind pressure sensor 10 increases, and when the air volume decreases, the output also decreases. Similarly for the pressure sensor 9, the sixth
As shown in the figure, when the pressure inside the vacuum cleaner increases, the output of the amplifier 15 of the pressure sensor 9 also increases, and when the pressure decreases, the output of the amplifier 15 also decreases.

FIG. 7 shows waveforms at each part of the power control device of the present invention, and a, b, c, and d show waveforms at positions corresponding to each part in FIG. 4, respectively. FIG. 7A shows a triangular waveform applied to the non-inverting terminal of the comparator 19, and this triangular wave is synchronized with the power cycle of the AC power source. C is the output potential of the analog multiplexer 16, and the potential of the output C increases or decreases depending on the outputs of the wind pressure sensor 10 and the pressure sensor 9. For example, when the air volume inside the vacuum cleaner increases, the potential C increases and intersects the triangular wave 20 at a at the position X, in which case the output b of the comparator 19 becomes a square wave as shown in FIG. Become. Furthermore, the square wave is differentiated by a differentiator circuit consisting of a capacitor 21 and a resistor 22, and a differential pulse shown in FIG. 7 is applied to the base of the transistor 12, turning the transistor 12 ON.
state, current flows into the gate of the bidirectional thyristor 11 via the resistor 13, the bidirectional thyristor 11 is turned on, and current is supplied to the electric blower 8. The waveform in this case is shown in FIG. Conversely, when the air volume decreases, the potential of the output C decreases and intersects the triangular wave 20 at the y position, so each waveform changes as shown in FIG. In this way, when the air volume decreases, it works to increase the air volume, and when the air volume increases, it works to decrease the air volume, so constant air volume control is performed.

In the case of a pressure sensor, constant pressure control is also possible in the same way as above.

Also, according to FIG. 4, analog multiplexer 1
The output of the comparator 17 is applied to the input switching terminal of the wind pressure sensor 10, and the output A of the amplifier 14 of the wind pressure sensor 10 and the reference power source 18 are compared by the comparator 17. Here, when the potential of the reference power source 18 is low, the comparator 17 sends a switching signal such that the analog multiplexer 16 selects the input A, and operates in the constant air volume control region. On the other hand, if the air volume decreases and the amplifier output A becomes smaller than the reference power supply 18, the comparator 1
7 sends a switching signal so that the analog multiplexer 16 selects input B, and automatically switches to the constant pressure control region. In other words, as shown in the P-Q characteristic in Fig. 3, when the air volume fluctuates within a certain range, the operation is in the constant air volume control range, and the floor nozzle 4 is in close contact with the floor surface and the air volume is within the certain range. When the pressure drops further, the control will automatically switch to the constant pressure control area.

Effects of the Invention As described above, the present invention controls the electric power of the electric blower by disposing pressure detection and air volume detection sensors on the intake and exhaust sides of the electric blower.
The following excellent effects can be obtained.

Normally, an electric blower is controlled by a wind pressure sensor to maintain a constant air volume, allowing for reliable cleaning.

When the above-mentioned constant air volume cannot be controlled, the rotation of the electric blower is regulated by the pressure sensor so that the vacuum pressure does not exceed a predetermined value, which may cause the blower to rotate at an abnormally high speed and cause a malfunction. can be prevented.

Therefore, the floor nozzle part does not come into close contact with the floor surface, etc., which improves operability and is also effective in reducing noise.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a vacuum cleaner, Fig. 2 is an enlarged sectional view of main parts of the vacuum cleaner of the present invention, Fig. 3 is a graph showing the vacuum degree P - air volume Q characteristic, and Fig. 4 is the invention of the present invention. Figures 5 and 6 are graphs showing the input/output characteristics of the wind pressure sensor and pressure sensor amplifiers, respectively, and Figure 7 shows the waveforms of each part of the power controller shown in Figure 4. This is a graph showing. 8... Electric blower, 9... Pressure sensor, 10... Wind pressure sensor, 11... Bidirectional thyristor, 14, 15
...Amplifier, 16...Analog multiplexer, 1
7, 19... Comparator, 18... Reference power supply.

Claims (1)

[Claims] 1. A vacuum cleaner includes a pressure sensor disposed on the suction side of an electric blower provided in the vacuum cleaner, and a wind pressure sensor disposed on the exhaust side of the electric blower to detect air volume, and the output of the pressure sensor and the wind pressure sensor is an amplifier that amplifies each; a circuit that switches between the amplifier output of the pressure sensor and the amplifier output of the wind pressure sensor using a switching signal according to the amplifier output signal of the wind pressure sensor; and a predetermined air volume by the output of this circuit. A power control device for a vacuum cleaner comprising a constant pressure/constant air volume control device that controls the electric blower in accordance with the output of the wind pressure sensor in the air volume range, and controls the electric blower with the output of the pressure sensor in the air volume region below that range.