JPS6364208B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum cleaner, and an object thereof is to provide a vacuum cleaner with a dust clogging alarm device that can be expected to operate reliably.

Traditionally, dust clogging alarm devices in vacuum cleaners have been used to warn people that if the dust box becomes excessively clogged with dust, the degree of vacuum inside the vacuum cleaner will increase, and the difference in pressure between the outside pressure and the inside of the vacuum cleaner will increase. When the air protector is operated, the resonance sound generated by the air flow is used as a clogging alarm. However, due to variations in the characteristics of the springs constituting the air protector and incomplete air tightness, the operation itself includes considerable instability, and reliable operation cannot be expected.
Furthermore, since a horn is emitted when the electric blower is in operation, it is difficult to hear the alarm sound.

Therefore, the present invention provides a detector that detects the intake air volume or exhaust air volume by an electric blower and generates a signal according to the detected air volume, and detects the signal by comparing the signal of this detector with a reference signal corresponding to the lowest air volume detection signal. and an alarm control circuit that turns off the power supply circuit of the electric blower via a time constant circuit and emits an alarm sound when the air volume is less than the minimum air volume and the electric blower is energized, so that the alarm sound is easy to hear, and It is designed to operate more accurately than the conventional one, and one embodiment of the present invention will be described below as a first embodiment.
This will be explained based on FIGS.

FIG. 1 is a cross-sectional view of a vacuum cleaner. Reference numeral 1 denotes a main body case of the vacuum cleaner, in which a filter 2 and an electric blower 3 disposed behind the filter 2 are built. 4 is a hose, 5 is the main body case 1
A connecting pipe 6 connects the hose 4 to the exhaust port, and the air and dust sucked from the hose 4 are separated by the filter 2, the dust is stored in the dust box 7, and the air is released to the atmosphere from the exhaust port 6. be done.
8 is an airflow sensor that detects the airflow inside the vacuum cleaner; for example, when the airflow increases, the output voltage decreases;
When the air volume decreases, the output voltage increases.

FIG. 2 shows the configuration of the power supply circuit of the electric blower 3 and the clogging alarm control circuit. 9 is a commercial power source, and 10 is a terminal to which the output voltage of the air volume sensor 8 is applied. 11 is a hand switch, 12 is a hand switch drive circuit, and 13 is a DC power supply circuit. One end of the hand switch drive circuit 12 is connected to the connection point between one end of the commercial power supply 9 and one end of the electric blower 3, and the hand switch 12 The other end is the DC power supply circuit 13
It is connected to the other end of the commercial power supply 9 via. That is, when the hand switch 11 is turned on, current is supplied to the DC power supply circuit 13 for the first time, and
A DC voltage is generated in the DC power line 14 of the DC power supply circuit 13 . A comparator 15 compares the reference voltage generated by the DC power supply circuit 13 with the voltage at the terminal 10, and its output is input to the time constant circuit 16. Note that both the comparator 15 and the time constant circuit 16 are configured to be supplied with current from the DC power supply circuit 13. The output of the time constant circuit 16 is connected to the gate terminal of the thyristor 17.
An alarm circuit 18 is interposed between the anode terminal and the DC power line 14, and the thyristor 17
The cathode terminal of is connected to the other end of the commercial power supply 9. The alarm circuit 18 referred to herein is constituted by a combination circuit of a buzzer or an oscillator and a sounding body, or a circuit that generates such an alarm sound and a light emitting element. In addition, in FIG. 2, the DC power supply line 14 and the bidirectional high sensitivity control rectifier 1
The gate terminal of 9 [hereinafter referred to as SCR ₁ ] is resistor 2.
A diode 21 is interposed between the gate terminal of the SCR ₁ 19 and the anode terminal of the thyristor 17. Furthermore, SCR ₁ 19
The T ₂ terminal and the other end of the electric blower 3 are connected via a resistor 22, and the T ₁ terminal of the SCR ₁ 19 is connected to a gate terminal of a bidirectional control rectifier 23 (hereinafter referred to as SCR ₂ ). . The T ₂ terminal and the T ₁ terminal of the SCR ₂ 23 are interposed between the other end of the electric blower 3 and the other end of the commercial power source 9 .

Because of this configuration, the hand switch 11 can be operated without dust being clogged in the dust box 7.
When the switch becomes ON, the hand switch drive circuit 12
A current is supplied to the DC power supply circuit 13 via the DC power supply line 14, and a DC voltage is generated in the DC power supply line 14. As a result, SCR ₂ 23 is electrically connected via SCR ₁ 19, and electric blower 3 is operated. Here, as mentioned above, since the dust box 7 is not clogged with dust, the air volume does not decrease, and the output voltage of the air volume sensor 8 is lower than the comparison reference potential created by the DC power supply circuit 13.
The output of the comparator 15 becomes Low level, the output of the time constant circuit 16 also becomes Low level, and the gate voltage of the thyristor 17 does not reach its trigger voltage.
Thyristor 17 is turned off. Further, since the diode 21 also remains reverse biased, no current is supplied to the alarm circuit 18. In other words, if the dust box 7 is not clogged with dust, the on/off operation of the hand switch 11 will turn it off.
The input power of the electric blower 3 can be turned on and off, but in that case, no current is supplied to the alarm circuit 18.

Next, when the dust box 7 is clogged with dust and the air volume is reduced, the output voltage of the air volume sensor 8 becomes higher than the comparison reference potential created by the DC power supply circuit 13, and the output of the comparator 15 becomes Hi. level, the output of the time constant circuit 16 also becomes Hi level, the thyristor 17 becomes conductive, current is supplied to the alarm circuit 18, and an alarm sound is emitted. Furthermore, as the thyristor 17 becomes conductive, the diode 21 is biased in the forward direction and the SCR ₁ 19 is reversed to the OFF state, thereby the SCR ₂ 23 is also reversed to the OFF state, and the electric blower 3 is automatically energized. is turned off. In this way, since the operation of the electric blower 3 is stopped and the alarm sound is generated, the alarm sound can be reliably heard. This state is maintained until the hand switch 11 is turned off.

The time constant circuit 16 is interposed to prevent malfunction due to temporary clogging of the hose 4, so that accurate operation can be expected.

FIG. 3 shows a specific example of the air volume sensor 8. 2
Reference numeral 4 denotes a wind receiving plate attached to the rotating shaft 26 of the variable resistor 25, which is disposed within the air flow path and is connected to the spring 2.
7 in one direction, and is configured to extract the magnitude of the air flow 28 as a change in the resistance value of the variable resistor 25. In addition, in FIG. 1, the air volume sensor 8 is arranged on the suction side of the electric blower 3, but
This is the same even if it is disposed on the discharge side, and it is also the same even if it is configured so that the air volume is extracted as a change in current.

As explained above, according to the vacuum cleaner of the present invention, an alarm sound is emitted when the garbage is clogged, and the operation of the electric blower is stopped, so the alarm sound is not only easier to hear than the conventional one, but also It is now possible to perform more accurate operations than before, greatly improving usability, and its practical value is extremely high. Further, since a time constant circuit is provided, for example, even if a hose or the like is temporarily clogged, the electric blower will not stop or an alarm will be generated, and so-called malfunctions can be prevented.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the vacuum cleaner of the present invention, Fig. 2 is a configuration diagram of the electric blower power supply circuit and alarm control circuit of the device shown in Fig. 1, and Fig. 3 is a perspective view of an example of the air volume sensor. It is. 1...Body case, 2...Filter, 3...Electric blower, 4...Hose, 5...Connection pipe, 6...Exhaust port,
7...Dust box, 8...Air volume sensor [detector],
9...Commercial power supply, 11...Hand switch, 12...Hand switch drive circuit, 13...DC power supply circuit, 14...
DC power supply line, 15... Comparator, 16... Time constant circuit, 17... Thyristor, 18... Alarm circuit, 1
9...Bidirectional high-sensitivity control rectifier element, 20, 22...
Resistor, 21... Diode, 23... Bidirectional control rectifier, 24... Wind receiving plate.

Claims (1)

[Claims] 1 A detector that detects the suction air volume or exhaust air volume by an electric blower and generates a signal according to the detected air volume, and compares the signal of this detector with a reference signal corresponding to the minimum air volume detection signal to determine whether the detected air volume is the lowest air volume. A vacuum cleaner according to the following, further comprising: an alarm control circuit that turns off a power supply circuit of the electric blower via a time constant circuit and generates an alarm sound when the electric blower is energized.