Low noise refrigerator and noise control method thereof

• US 5,127,235 A
• Filed: 12/14/1990
• Issued: 07/07/1992
• Est. Priority Date: 12/18/1989
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Toshiba Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sekiguchi, Yasuyuki, Nakanishi, Keiji
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US07/626,042
• Time in Patent Office: 571 Days
• Field of Search: 381/71, 381/73.1, 381/94, 62/296, 62/115, 417/14, 417/312, 181/202, 181/200, 181/206
• US Class Current: 62/115
• CPC Class Codes: F25B 2500/12 Sound
• 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 11/17817 between the output signals and the error signals, i.e. secondary path
• 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 11/17883 the reference signal being derived from a machine operating condition, e.g. engine RPM or vehicle speed
• 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
• CPC Class Codes: G10K 2210/3229 Transducers

Abstract

In a low noise refrigerator, a rotary 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 having a cross-sectional dimension which is small relative to trhe wavelength of the noise which is to be reduced. A vibration pick-up being located in the vicinity of the rotary compressor. The vibration pick-up detects compressor vibrations which correlate to the compressor noise, in the tangential direction 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 rotary compressor for compressing a refrigerant, the rotary compressor constituting a substantial noise source;

a machine chamber for accommodating said rotary 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 sufficiently small relative to the wavelength of said compressor noise to be reduced;

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

a control circuit for processing an output signal of said vibration 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, further comprising means for mounting said vibration pick-up, the mounting means being a projection on a circumferential surface of said rotary compressor.

3. A refrigerator as recited in claim 2, wherein said mounting means is a plate-shaped jig.

5. 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 rotary compressor and said opening, G_SM is a sound transfer function between said rotary compressor and said vibration pick-up.

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

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

8. A refrigerator as recited in claim 6, wherein said sound generator is provided in said machine chamber close to said opening.

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

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

10. A refrigerator having a silence system comprising:

a rotary compressor including a motor unit for compressing a refrigerant, the rotary compressor constituting a substantial noise source;

a machine chamber for accommodating said rotary compressor, wherein the machine chamber is provided with an opening in one location, the 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 in the tangential direction of said rotary compressor, wherein the compressor vibrations are representative of said compressor noise, the vibration pick-up being located in close vicinity to said motor unit of said rotary compressor;

a control circuit for processing an output signal of said vibration 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.

11. A refrigerator as recited in claim 10, wherein said vibration pick-up is mounted on an end face of said motor unit.

12. A refrigerator as recited in claim 10, further comprising means for mounting said vibration pick-up, the mounting means being a projection on an end face of said motor unit.

13. A refrigerator as recited in claim 12, said mounting means is a bolt.

14. A method for noise controlling a refrigerator eqiupped with a vibration pick-up located in the vicinity of a rotary compressor and a sound generator provided in a machine chamber of the refrigerator, the machine chamber having a 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, the method comprising the steps of:

detecting a tangential component of said rotary compressor vibrations with said vibration pick-up, said vibrations representing the noise generated from said rotary compressor;

processing an output signal of sid vibration pick-up to determine amplitude and frequency of a control sound to be generated in response to said rotary compressor noise; and

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