JPS58116334A - Electric cleaner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum cleaner, and an object of the present invention is to improve the control response of an energy-saving vacuum cleaner that does not allow more than necessary input power to be passed to an electric blower.

In general, when the filter of a vacuum cleaner becomes clogged and the air volume decreases, there is a device shown in FIG. 1 that increases the input power of an electric blower to compensate for this decrease. That is, 1 is a case of the vacuum cleaner body, 2 is a filter, and an electric blower 3 is provided behind it. 4 is a hose, and 5 is a connecting pipe that connects the case 1 and the hose 4. The dust-containing air sucked through the hose 4 is separated from dust by the filter 2 5, and purified air is discharged from the exhaust port 6. 7 is an air volume sensor provided between the front of the electric blower 3 and the filter 2. As shown in FIG. 2, this function involves inputting a signal from the air volume sensor 7 to a control circuit 8, and operating the electric blower 3 using its output. The configuration of the control circuit 8 is as shown in FIG. 3, in which the output of the sensor 7 is used in a comparison circuit 9 to determine whether the air volume is small or appropriate relative to the set value. When the output of the comparator circuit 9 is larger or smaller than the set value, the value in the memory circuit 1o is increased or decreased. Do not change when appropriate. Then, the input power control circuit 11 determines the input to the electric blower 3 based on the value of the memory circuit 10. By the way, conventionally, the configuration of the sensor 7 is as shown in FIG. 4, in which a hot wire 12 and a resistor 13 are connected in series to which a voltage is applied. The hot wire 12 is made of metal such as platinum or tungsten. The voltage of the resistor 13 becomes an input to the control circuit 8. When the air volume is large, the temperature of the hot wire 12 becomes low and its resistance value becomes small. Therefore, the current flowing through the hot wire 12 and the resistor 13 increases, and the voltage applied to the resistor 13 increases. Therefore, sensor 7
The output becomes larger, indicating that the air volume is large. Conversely, when the air volume decreases, the temperature of the hot wire 12 increases and its resistance increases, so the current flowing through the hot wire 12 and the resistor 13 decreases, the voltage across the resistor 13 decreases, and the sensor 7
output decreases. In other words, the air volume is low. In this way, while the output of the sensor 7 is high or low, the value in the memory circuit 1o continues to increase or decrease, and therefore the input to the electric blower 3 continues to increase or decrease. When the air volume reaches the set value, the output of the sensor 7 becomes a proper value, the memory circuit 1o stops increasing and decreasing, and the input power of the electric blower 3 is maintained at the value at that time.

In the above configuration, the input power of the electric blower 3 is supplied to the memory circuit 1.
The comparison circuit 9 determines the output of the sensor 7 when the air volume is larger or smaller than the set value, and increases or decreases the value of the storage circuit 1o based on the output. therefore,
Since the value of the memory circuit 1o changes, the input power control circuit 1
The output of 1 increases or decreases. Therefore, the input power of the electric blower 3 increases or decreases. When the air volume reaches the set value, the output of the comparison circuit 9 that compares and judges the output of the sensor indicates that it is an appropriate value, and the value in the memory circuit 11 is not increased or decreased, so the input power of the electric blower 3 is maintained at the input at that time. dripping

However, since the sensor 7 is configured with a hot wire 12, it is necessary to heat the hot wire 12 to a high temperature in order to increase its sensitivity.

For this purpose, as shown in FIG. 4, it is necessary to lower the voltage from the AC commercial power source to low-voltage AC using a transformer 14, and to flow a large amount of current from a DC power source 16 rectified using a diode 15. This DC power supply 16 is also necessary to operate the control circuit 8, but since the control circuit 8 is a semiconductor element, it can be driven with a low current, but a large current must be passed through the sensor 7, and the rating of the transformer 14 is This has the drawbacks of requiring a large size, increasing costs, being heavy, having a large shape, and being subject to major restrictions on space for installation inside the vacuum cleaner, cooling, etc.

The present invention aims to eliminate the above-mentioned conventional drawbacks and provide a sensor that is inexpensive and has fewer design restrictions by reducing the size of the transformer.Examples of the present invention will be described below with reference to the accompanying drawings.

In Fig. 6, to explain the sensor and power supply part, AC
The electric blower 3 and the control circuit 8 are connected in series from the power source,
Power is supplied to the control circuit 8 from an AC power supply by a DC power supply 19 composed of a transformer 17, a diode 18, etc., and the sensor 7 is supplied with power from a DC power supply 22 rectified by a diode 21 from a field coil 20 of the electric blower 3. Power is supplied. For the electric blower 3, a commutator motor is normally used in the case of a vacuum cleaner, and its configuration is such that a field coil 20, an armature 23, and another field coil 24 are connected in series. coil 20
The voltage of ACl is about 0 to 20 V, and as a driving power source for the electronic circuit, it is composed of a heating wire 25 and a resistor 26, and its output is connected to the control circuit 8. ing.

With the above configuration, when the air flow rate decreases below the set value, the temperature of the hot wire 26 increases, the resistance value increases, the current decreases, and the output of the sensor 7 decreases.

Therefore, the control circuit 8 increases the input to the electric blower 3, and the air volume returns to its original value. Conversely, if the floor nozzle is separated from the floor and the air flow is too large, the temperature of the hot wire 26 decreases, the resistance value decreases, the current increases, and the output of the sensor 8 increases.

For this reason, the control circuit 8 reduces the input to the electric blower 3, restores the air volume to the original value, and cuts unnecessary power. Conventionally, a transformer was required to drive the hot wire, and the extra transformer needed to be large, but according to the present invention, the power for the hot wire can be taken from the field coil 20 of the electric blower 3, and the control Since the circuit transformer consumes almost no power, it can be made small, and the cost is low, and the installation space inside the vacuum cleaner can be easily secured.

FIG. 6 shows the relationship between the air volume and the vacuum seat of a vacuum cleaner using such a sensor.

As described above, according to the present invention, the set air volume can be kept below a certain level, which is economical, and at the same time, it is possible to reliably secure the air volume necessary for one cleaning.

Although the sensor has been described on the intake side of the electric blower, it may be provided anywhere in the air flow path and on the exhaust side. Also, although the power supply for the control circuit and the sensor were separate, the power supply for the control circuit was taken from the power supply for the sensor, and the power supply was made into one from the field coil of the electric blower, eliminating the transformer and diode for the control circuit. In addition, further cost reduction and compactness can be achieved.

Also, although the sensor has been explained as a hot wire, it does not have to be a hot wire such as platinum or tungsten, but any material whose resistance value changes due to heat, such as a thermistor or resistor, can be used.
Similar effects can be obtained.

Further, it is not necessary to use all of the field coil of the electric blower as a power source, and a part of the field coil may be used by drawing out the IJ+ from the middle of the field coil.

As described above, according to the present invention, the air volume sensor installed in the air flow path of the vacuum cleaner is driven by the DC power source taken from the field coil of the electric blower, and the output is compared to the set value by the comparison circuit. By detecting whether the airflow is appropriate, increasing or decreasing the value in a memory circuit when it is large or small, and setting the input power of the electric blower based on the value in the memory circuit, the airflow is controlled to always maintain a constant air volume. Even if the filter becomes clogged with dirt, it can be cleaned without reducing the cleaning ability, and when the floor nozzle is away from the floor, the air volume is kept constant, reducing unnecessary power consumption. With no,
This can be achieved at low cost and compactly, and its effects and effects are outstanding.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a vacuum cleaner, Figs. 2 and 3 are block diagrams of its control circuit, Fig. 4 is a conventional circuit diagram of an air volume sensor and a power supply section, and Fig. 5 is a nine-dimensional diagram of the present invention. '・-"〆The circuit diagram of the air volume sensor and power supply section showing the embodiment, and Fig. 6 is the same characteristic diagram. 3... Electric blower, 7... Air volume sensor, 8...control circuit, 9...comparison circuit,
1o... Memory circuit, 11... Input power control circuit, 20... Field coil. Figure 1 Figure 2 and Figure 3 Figure 4

Claims (1)

[Claims] An air volume sensor installed in the air flow path whose resistance changes depending on temperature, a comparison circuit that compares the output of this air volume sensor with a set value, and an input power control circuit that sets the input power of the electric blower based on the output of this comparison circuit. What is claimed is: 1. A vacuum cleaner having a constant air volume control device, and having an air volume sensor driven by a DC power source obtained from a field coil of an electric blower.