JPS59108531A - 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 (Field of Industrial Application) The present invention relates to a pressure-controlled vacuum cleaner that reduces operating force by controlling the pressure within a dust box to a constant level.

(Configuration of the conventional example and its problems) 3. Explaining the conventional example with reference to FIGS. 1 and 2.
Figure 1 shows the overall configuration of a conventional pressure-controlled vacuum cleaner, where 1 is the vacuum cleaner body, 2 is the filter, :( is the electric blower, 4 is the hose inserted into the intake port 5, and 6 is the exhaust air). Reference numeral 8 denotes a pressure detector placed in the chamber 7 of the vacuum cleaner body. Based on the detection signal of the pressure detector 8, the voltage applied to the electric blower 3 can be changed to control the stain vacuum cleaner. The suction pressure is controlled to be kept constant.As shown in FIG. The fixed electrode 12 and the pressure detection plate 1 are arranged opposite to each other.
Pressure is detected using changes in capacitance between
A so-called capacitive pressure sensor or the like is used. However, such conventional pressure-controlled vacuum cleaners are expensive because the pressure sensor requires a precise structure, and the pressure sensor is placed inside the vacuum cleaner, so it is difficult to remove dust. This has disadvantages such as pressure leakage and the risk of entering the detector, causing malfunction of the pressure detector.

(Objective of the Invention) An object of the present invention is to eliminate the drawbacks of the conventional pressure-controlled large vacuum cleaner as described above, and to provide a vacuum cleaner of this type that is inexpensive and less likely to malfunction.

(Structure of the Invention) The pressure-controlled vacuum cleaner according to the present invention detects the suction pressure from the rotation speed and applied voltage of the electric blower, without using a pressure detector like in the past, and detects the suction pressure of the electric blower based on the detected rotation speed and applied voltage. The suction pressure is controlled by changing the rotation speed.

(Explanation of Embodiments) The basis for explaining specific embodiments of the present invention. First, the relationship between suction pressure and air volume of a vacuum cleaner, rotation speed and air volume of an electric blower, rotation speed and suction pressure of an electric blower, etc. This will be explained with reference to FIGS. 3 to 6.

Figures 3 and 4 show the relationship between suction pressure P and wind i (Q) in a vacuum cleaner, and the rotational speed N of an electric blower, respectively.
This graph shows the relationship between Q and air volume Q, and when the voltage V applied to the electric blower is changed, the characteristic curve moves approximately in parallel as shown. The relationship between the suction pressure F and the rotational speed N of the electric blower is shown in Fig. 5, and in this case as well, when the voltage V applied to the electric blower is changed, the characteristic curve becomes approximately Move parallel. When the voltage V applied to the electric blower changes from V+ to V2 to V3 with respect to the rotational speed nl, the suction pressure P becomes P+ lP2 1P3.

Focusing on this point, the present invention calculates the suction pressure of a vacuum cleaner from the rotation speed and applied voltage of the electric blower, and maintains the suction pressure constant by changing the applied voltage to the electric blower based on this. It is. Next, the principle of the present invention will be explained with reference to FIG. In FIG. 6, a shows a characteristic curve showing the relationship between the rotation speed N of the electric blower and the suction pressure P, and b shows a load curve of the vacuum cleaner. First, for a load of LI, the electric blower has a rotation speed n on the ml curve.
', the engine is operated at a position where the suction pressure is Pl. Next, when the load increases and changes from L2 to L2, the rotation speed of the electric blower changes from nl to n3 and the pressure changes from pl to p2. If this pressure change is detected from the rotational speed and applied voltage of the electric blower as described above, and the rotational speed is changed from n3 to 02 by changing the applied voltage to the electric blower based on that, the suction pressure will be p2. It is possible to return to pI and maintain the pressure of pI.

Next, an embodiment of a constant pressure control circuit in a pressure-controlled vacuum cleaner according to the present invention will be described with reference to FIG. In the figure, 14 is a rotation speed detector that detects the rotation speed of the electric blower. For example, it uses a tacho generator, a photo sensor, a Hall element, etc., and 1 and 15 are installed at appropriate locations on the electric blower. A voltage detection circuit for detecting voltage, l61d, an operational amplifier, 17 a feedback element such as a resistor and a capacitor, 18 a phase control circuit that controls the bidirectional thyristor 19 according to the output of the operational amplifier 16, and 20 an electronic 21 and the bidirectional thyristor 19 are connected in series. By appropriately selecting the value of the feedback element 17 of the operational amplifier 16 that calculates the output of the rotation detector 14 and the output of the voltage detection circuit 15, the suction pressure of the vacuum cleaner becomes constant.

(Effects of the Invention) As explained above, the present invention makes it possible to detect and control the suction pressure of a vacuum cleaner without using a conventional pressure detector. Therefore, according to the present invention, it is possible to provide a pressure-controlled vacuum cleaner that is inexpensive and has fewer failures.

[Brief explanation of the drawing]

Figure 1 is a schematic overall configuration diagram of a conventional pressure-controlled vacuum cleaner, Figure 2 is a sectional view showing an example of the pressure detector in Figure 1, and Figure 3 is the air volume and suction in a pressure-controlled vacuum cleaner. Figure 4 is a characteristic diagram showing the relationship between pressure, and Figure 4 is a characteristic diagram showing the relationship between air volume and electric blower rotation speed. Figure 5 is a characteristic diagram showing the relationship between suction pressure and electric blower rotation speed, and Figure 6 is a characteristic diagram showing the relationship between suction pressure and electric blower rotation speed. 7 is a diagram showing the relationship between rotational speed and suction pressure and a load curve of an electric blower for detailed explanation of the present invention, and FIG. 7 is an embodiment of a constant pressure control circuit in a pressure-controlled vacuum cleaner according to the present invention. FIG. ■... Vacuum cleaner body, 2... Filter, ; 3- Electric blower, 4... Hose, 5... Intake port, 6... Exhaust port, 7... Chamber, 8... Pressure detection 14... Rotation speed detector, 15... Voltage detection circuit, 16... Operational amplifier, 17... Feedback element, 18... Phase control circuit, 1
9... Bidirectional thyristor, 20... Motor. Figure 1 Figure 2 Figure 3 O. Figure 4 Figure 5

Claims (1)

[Claims] In a pressure-controlled vacuum cleaner that has an electric blower, filter, etc. inside the main body and maintains the suction pressure constant, the suction pressure is detected from the rotation speed of the electric blower and the applied voltage.
Based on this, a vacuum cleaner is characterized by an electric blower (the suction pressure is controlled by changing the rotation speed of the shell).