Method and apparatus for operating vacuum cleaner

• US 4,958,406 A
• Filed: 12/14/1988
• Issued: 09/25/1990
• Est. Priority Date: 12/15/1987
• Status: Expired

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Jyoraku, Fumio, Koharagi, Haruo, Miyashita, Kunio, Tahara, Kazuo, Endo, Tunehiro, Saito, Kouichi, Ishii, Yoshitaro, Toyoshima, Hisanori, Watanabe, Syuji, Hishi, Wakichiro
• Primary Examiner(s): Moore, Chris K.
• Application Number:
  US07/284,382
• Time in Patent Office: 650 Days
• Field of Search: 15/319, 15/339
• US Class Current: 15/319
• CPC Class Codes: A47L 9/2821 Pressure, vacuum level or airflow
• CPC Class Codes: A47L 9/2826 the condition of the floor
• CPC Class Codes: A47L 9/2831 Motor parameters, e.g. motor load or speed
• CPC Class Codes: A47L 9/2842 Suction motors or blowers
• CPC Class Codes: A47L 9/2889 Safety or protection devices or systems, e.g. for prevention of motor over-heating or for protection of the user
• CPC Class Codes: A47L 9/2894 Details related to signal transmission in suction cleaners
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

In a vacuum cleaner comprising an electric blower and a speed control unit to operate the electric blower at a variable speed, a plurality of kinds of operation control rules of the electric blower are previously stored in the speed control unit, a load current value of the electric blower is continuously detected during the cleaning and the type of the surface to be cleaned is estimated from the load current value. Thereafter, the operation control rule suitable for the estimated cleaning surface is selected from the operation control rules stored in the speed control unit and the electric blower is driven on the basis of the selected operation control rule.

Claims

1. A method of operating a vacuum cleaner having at least an electric blower and a speed control unit for controlling the operating speed of said electric blower, said speed control unit having stored therein a plurality of operation control rules for controlling said electric blower, said method comprising the steps of:

detecting continuously a value of a load current of said electric blower during a cleaning operation;

determining a type of surface being cleaned in response to said detected load current;

selecting one of said plurality of operation control rules based upon the determination of the type of surface being cleaned; and

controlling said electric blower in accordance with said selected one of said plurality of operation control rules.

2. A method according to claim 1, wherein said plurality of operation control rules for said electric blower include at least:

a first operation control rule in which a rotational speed of said electric blower is controlled to be constant;

a second operation control rule in which said rotational speed of said electric blower increases when an air flow rate decreases;

a third operation control rule in which said rotational speed of said electric blower decreases when said air flow rate decreases; and

a fourth operation control rule in which an input to said electric blower is reduced during a predetermined period when said vacuum cleaner is not performing a cleaning operation.

3. A method according to claim 1, wherein said plurality of operation control rules stored in said speed control unit include operation control rules for at least four cleaning surfaces, said at least four surfaces including at least a floor plate, a tatami, a carpet, and a curtain.

4. A method according to claim 1, wherein said selected one of said plurality of operation control rules causes said electric blower to be controlled by said speed control unit in accordance with a shunt-wound characteristic.

5. A method according to claim 1, wherein said determining step determines said cleaning surface based on a fluctuation range of said load current value over a predetermined period of time.

6. A method according to claim 1, wherein said selected operation control rule is automatically selected from among said plurality of operation control rules stored in said speed control unit in response to the determination of type of surface being cleaned, and wherein at least one of said plurality of operation control rules stored in said speed control unit can be manually selected.

7. A method according to claim 1, wherein said speed control unit includes a microcomputer and said plurality of operation control rules for said electric blower are stored in said microcomputer.

8. A vacuum cleaner comprising:

an electric blower for collecting dust in a dust chamber through a suction port, said electric blower creating a suction pressure;

blower control means for controlling a rotational speed of said electric blower;

control rule generating means for generating a plurality of control rules for controlling the operation of said vacuum cleaner;

means for selecting one of said plurality of control rules generated by said control rule generating means; and

signal processing means for processing said selected one of said plurality of operation control rules and for outputting a control signal to said blower control means so as to control operation of said electric blower in accordance with said selected control rule.

9. A vacuum cleaner according to claim 8, wherein said signal processing means comprises a microcomputer and said control rule generating means comprises a plurality of memories in which data relating to predetermined operating parameters of said vacuum cleaner are stored.

10. A vacuum cleaner according to claim 8, wherein said signal processing means comprises a microcomputer, said control rule generating means includes a plurality of dependent memories for storing data relating to predetermined operating parameters of said vacuum cleaner, and said means for selecting selects one of said plurality of control rules by switching between said plurality of independent memories.