Low noise refrigerator and noise control method thereof

• US 5,117,642 A
• Filed: 12/14/1990
• Issued: 06/02/1992
• Est. Priority Date: 12/18/1989
• Status: Expired due to Term

• Current Assignee: Toshiba Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sekiguchi, Yasuyuki, Nakanishi, Keiji
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US07/626,705
• Time in Patent Office: 536 Days
• Field of Search: 381/71, 381/73.1, 381/94, 62/296, 62/115, 417/14, 181/202, 181/200, 181/206
• US Class Current: 62/115
• CPC Class Codes: F25D 2201/30 with respect to sound
• CPC Class Codes: F25D 23/00 General constructional features F25D21/00 takes precedence
• CPC Class Codes: G10K 11/17815 between the reference signals and the error signals, i.e. primary path
• CPC Class Codes: G10K 11/17817 between the output signals and the error signals, i.e. secondary path
• CPC Class Codes: G10K 11/17819 between the output signals and the reference signals, e.g. to prevent howling
• CPC Class Codes: G10K 11/17853 of the filter
• CPC Class Codes: G10K 11/17857 Geometric disposition, e.g. placement of microphones
• CPC Class Codes: G10K 11/17861 using additional means for damping sound, e.g. using sound absorbing panels
• CPC Class Codes: G10K 11/17879 using both a reference signal and an error signal
• CPC Class Codes: G10K 11/17881 the reference signal being an acoustic signal, e.g. recorded with a microphone
• CPC Class Codes: G10K 2210/1054 Refrigerators
• CPC Class Codes: G10K 2210/109 Compressors, e.g. fans
• CPC Class Codes: G10K 2210/3036 Modes, e.g. vibrational or spatial modes
• CPC Class Codes: G10K 2210/3045 Multiple acoustic inputs, single acoustic output

Abstract

In a low noise refrigerator, a compressor constituting a noise source is arranged within a machine chamber provided with an opening in one location, which chamber has a one-dimensional duct construction in which its cross-sectional dimension is small relative to the wavelength of the noise which is to be reduced. A vibration pick-up is located in the vicinity of the compressor. The vibration pick-up detects compressor vibrations which correlate to the compressor noise of the compressor. There is provided a control circuit that processes the output signal of the vibration pick-up. In the machine chamber, a sound generator is driven by the output signal of the control circuit to generate a control sound, so that the compressor noise which tries to issue from the opening is canceled by the control sound.

Claims

1. A refrigerator having a silencer system comprising:

a compressor for compressing a refrigerant, the compressor constituting a substantial noise source;

a machine chamber for accommodating said compressor, wherein the machine chamber is provided with an opening in one location, the machine chamber having a one-dimensional duct construction in which a cross-sectional dimension of the duct is small relative to the wavelength of said compressor noise to be reduced;

a vibration pick-up for detecting compressor vibrations of said compressor, wherein the compressor vibrations are representative of said compressor noise, the vibration pick-up being located in the vicinity of said compressor;

a control circuit for processing an output signal of said pick-up; and

a sound generator for generating a control sound corresponding to said compressor noise, wherein the sound generator is driven by an output signal from said control circuit.

2. A refrigerator as recited in claim 1, wherein said machine chamber is located substantially at the lowest part at the back face of said refrigerator.

3. A refrigerator as recited in claim 1, wherein an elastic tape is mounted to the inner wall surface of said machine chamber.

4. A refrigerator as recited in claim 1, wherein said machine chamber has a duct length of approximately 640 mm.

5. A refrigerator as recited in claim 1, wherein said machine chamber has a duct length of approximately 880 mm.

6. A refrigerator as recited in claim 1, wherein the frequencies to be silenced are between 100 Hz and 800 Hz.

7. A refrigerator as recited in claim 1, wherein said control circuit is equipped with a finite impulse response filter for processing a signal in the time domain.

8. A refrigerator as recited in claim 1, wherein said control circuit has a transfer function G, whereby the transfer function G is determined by the following equations:

space="preserve" listing-type="equation">G=-G.sub.MR /G.sub.AR

space="preserve" listing-type="equation">G.sub.MR =G.sub.SR /G.sub.SM

where G_AR is a sound transfer function between said sound generator and said opening, G_SR is a sound transfer function between said compressor and said opening, G_SM is a sound transfer function between said compressor and said pick-up.

9. A refrigerator as recited in claim 1, wherein said compressor is arranged substantially at the farthest position from said opening within said machine chamber.

10. A refrigerator as recited in claim 1, wherein said sound generator is provided in said machine chamber close to said opening.

11. A refrigerator as recited in claim 9, wherein said sound generator is provided in said machine chamber close to said opening.

12. A refrigerator as recited in claim 1, wherein said sound generator is a speaker.

13. A refrigerator having a silencer system comprising:

a compressor for compressing a refrigerant, the compressor constituting a substantial noise source;

a machine chamber for accommodating said compressor, wherein the machine chamber is provided with an opening in one location, the machine chamber having a one-dimensional duct construction in which a cross-sectional dimension of the duct is small relative to the wavelength of said compressor noise to be reduced;

a vibration pick-up for detecting compressor vibrations of said compressor, wherein the compressor vibrations are representative of said compressor noise, the vibration pick-up is mounted on said compressor;

a control circuit for processing an output signal of said pick-up; and

a sound generator for generating a control sound corresponding to said compressor noise, wherein the sound generator is driven by an output signal from said control circuit.

14. A refrigerator as recited in claim 13, wherein said machine chamber is located substantially at the lowest part at the back face of said refrigerator.

15. A refrigerator as recited in claim 13, wherein said machine chamber having a duct length of approximately 640 mm.

16. A refrigerator as recited in claim 13, wherein said machine chamber having a duct length of approximately 880 mm.

17. A refrigerator as recited in claim 13, wherein the frequencies to be silenced are between 100 Hz and 800 Hz.

18. A refrigerator as recited in claim 13, wherein said control circuit is equipped with a finite impulse response filter for processing a signal directly in the time domain.

19. A refrigerator as recited in claim 13, wherein said control circuit has a transfer function G, whereby the transfer function G is determined by the following equations:

space="preserve" listing-type="equation">G=-G.sub.MR /G.sub.AR

space="preserve" listing-type="equation">G.sub.MR =G.sub.SR /G.sub.SM

where G_AR is a sound transfer function between said sound generator and said opening, G_SR is a sound transfer function between said compressor and said opening, G_SM is a sound transfer function between said compressor and said pick-up.

20. A refrigerator as recited in claim 13, wherein said compressor is arranged substantially at the farthest position from said opening within said machine chamber.

21. A refrigerator as recited in claim 13, wherein said sound generator is provided in said machine chamber close to said opening.

22. A refrigerator as recited in claim 20, wherein said sound generator is provided in said machine chamber close to said opening.

23. A refrigerator as recited in claim 13, wherein said sound generator is a speaker.

24. A refrigerator having a silencer system comprising:

a compressor for compressing a refrigerant, the compressor constitutes a noise source substantially;

a suction pipe for introducing the refrigerant to said compressor, wherein the suction pipe is connected to said compressor;

a machine chamber for accommodating said compressor, wherein the machine chamber is provided with an opening in one location, the machine chamber having a one-dimensional duct construction in which a cross-sectional dimension of the duct is small relative to the wavelength of said compressor noise to be reduced;

a vibration pick-up for detecting compressor vibrations of said compressor, wherein the compressor vibrations are representative of said compressor noise, the vibration pick-up is mounted on said suction pipe;

a control circuit for processing an output signal of said pick-up; and

a sound generator for generating a control sound corresponding to said compressor noise, wherein the sound generator is driven by an output signal from said control circuit.

25. A refrigerator as recited in claim 24, wherein said pick-up is mounted at the base portion of said suction pipe.

26. A refrigerator as recited in claim 24, wherein said compressor is arranged substantially at the farthest position from said opening within said machine chamber.

27. A refrigerator as recited in claim 24, wherein said sound generator is provided in said machine chamber close to said opening.

28. A method for noise controlling a refrigerator equipped with a vibration pick-up located in the vicinity of a compressor and a sound generator provided in a machine chamber of the refrigerator, the machine chamber being provided with an opening in one location and having a one-dimensional duct construction in which a cross-sectional dimension of the duct is sufficiently small relative to the wavelength of a compressor noise to be reduced, the method including the steps of:

detecting vibrations of the compressor by said vibration pick-up, said vibrations representing the noise generated from said compressor;

processing an output signal of said vibration pick-up in the time domain by a finite impulse response filter for determining amplitude and phase of a control sound to be generated in response to said compressor noise; and

driving said sound generator to generate said control sound for canceling said compressor noise by said interference action.

29. A method for reducing compressor noise of a refrigerator equipped with a compressor, located in a machine chamber with an opening on one side, comprising the steps of:

providing said machine chamber with one dimensional duct construction in which a cross-sectional dimension of the duct is sufficiently small relative to the wavelength of said compressor noise to be reduced;

detecting vibrations of said compressor with a vibration pick-up located in the vicinity of said compressor, said vibrations corresponding to said compressor noise;

processing an output signal of said vibration pick-up in the time domain by a finite impulse response filter for determining amplitude and phase of a control sound to be generated in response to said compressor noise; and

driving a sound generator, located in said machine chamber, to generate said controlled sound for canceling said compressor noise by sound interference action.