JPH0511234B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an operation inspection device for a rotary compressor, and more specifically, for automatically determining abnormal operation caused by the so-called flying phenomenon of rotary compressor blades. Concerning what was chosen to be inspected.

(Prior Art) Conventionally, there are rotary compressors used in refrigeration equipment. This one, for example,
As disclosed in Japanese Patent Application No. 57-178116, the rotor includes a cylinder, a rotor that rotates eccentrically while being inscribed in the cylinder, and a blade that moves in and out of the cylinder according to the eccentric rotation of the rotor, and the blade allows
The space formed by the cylinder and rotor is divided into a suction chamber and a compressor, and the volume is changed according to the rotation of the rotor, thereby compressing and discharging the refrigerant.

(Problems to be Solved by the Invention) By the way, once the production of a rotary compressor as described above is completed, a test run is usually conducted to check whether the input voltage, input current, suction pressure, operating noise, etc. are normal. A driving test is being conducted. In this case, abnormal operating noise caused by the so-called blade flying phenomenon, in which the blades cannot properly follow the eccentric rotation of the rotor of the rotary compressor, is generally determined by a sound test by an expert. The current situation is that

However, regular acoustic tests for driving sound caused by the blade flying phenomenon described above tend to be subjective, resulting in variations in judgment due to the fatigue of experts, and the drawbacks are that objective and quantitative tests cannot be performed. be.

Therefore, the present inventors collected the inspection sounds of good products that do not cause the blade flying phenomenon and defective products that do, using a noise sensor such as a microphone, and at the same time collected the test sounds using a vibration sensor such as a microphone. When measured using a non-defective product, the repetition period of the waveform was constant, as shown in Figure 7 (a), whereas in the defective product, as shown in Figure 7 (b), this was not constant. It turned out that there was.

The present inventor has focused on this point, and the purpose is to investigate the aperiodicity (standard deviation of the period) of the period of the operating sound or vibration of the rotary compressor as described above. To objectively and quantitatively automatically inspect abnormal operating noise caused by a blade flying phenomenon without relying on experts.

[Means for Solving the Problems] In order to achieve the above object, the solving means of the present invention includes a cylinder 4 and a rotor 6 that rotates eccentrically within the cylinder 4, as shown in FIG. Detection means for detecting operating noise or operating vibration of the rotary compressor A for the rotary compressor A whose volume is changed by blades 8 that appear and retract according to the eccentric rotation of the rotor 6. 15 or 16
and a period calculation means 3 which receives the output of the detection means 15 or 16 and calculates the period of driving noise or vibration.
0 and the output of the period calculation means 30, and calculates the aperiodicity S in the plurality of cycles based on the period of the driving sound or vibration.
and a signal generating means 32 which receives the output of the aperiodicity means 31 and generates an abnormal operation signal when the aperiodicity S is equal to or greater than a predetermined value Smax.

(Function) As described above, in the present invention, the non-periodic degree S of the period of the operating sound or vibration of the rotary compressor A is set to a predetermined value Smax in a non-defective product based on the characteristics of the period of the waveforms shown in Fig. 7 A and B. On the other hand, in the case of a defective product in which the blade flying phenomenon occurs, the noise level becomes larger than the predetermined value Smax and an abnormal operation signal is generated from the signal generating means 32. It is automatically detected objectively and quantitatively without relying on the pitch sense of an expert.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings from FIG. 2 onwards.

2 and 3 show a fixed blade rotary compressor A, which includes a drive motor 2 and a drive motor 2 in a casing 1.
The compressor is a hermetic compressor in which a compressor 3 driven by a compressor 3 is hermetically sealed, and the compressor 3 is connected to a cylindrical cylinder 4 and a lower part of the drive shaft 2a of the drive motor 2 via a crankshaft 5. The rotor 6 rotates eccentrically while being inscribed in the inner circumferential surface 4a of the cylinder 4.
and S can freely appear and retract from the inner circumferential surface 4a of the cylinder 4.
A blade 8 is provided which is biased toward the rotor 6 side by letter-shaped wire springs 7, 7 and is in sliding contact with the outer peripheral surface of the rotor 6, and the space 9 formed by the cylinder 4 and the rotor 6 is The chamber is divided into a suction chamber 10 and a compression chamber 11, and the volume is changed according to the eccentric rotation of the rotor 6.
Further, a suction port 12 that opens into the suction chamber 10 and the compression chamber 11 is provided on the inner circumferential surface 4a of the cylinder 4.
and a discharge port 13 are provided. Therefore, by operating the drive motor 2, the rotor 6 is inscribed in the inner peripheral surface of the cylinder 4 and eccentrically rotated in the direction of the arrow in FIG. The refrigerant gas in the compression chamber 11 is compressed as the compression chamber 11 contracts and is discharged from the discharge port 13 to the outside.

In the vicinity of the rotary compressor A, a noise sensor 15 is arranged as a first detection means, such as a microphone, for detecting the operating sound of the compression section 3 in close proximity to the casing 1.
A vibration sensor 16 consisting of an acceleration sensor or the like as a second detection means for detecting operational vibration of the compression section 3 is detachably attached to the casing 1 by a magnet or the like, and the detection signals of both the sensors 15 and 16 are are connected to a discriminating device 17 so as to be able to send and receive signals, and the discriminating device 17 determines whether the blades 8 of the compression section 3 do not follow the eccentric rotation of the rotor 6 and are temporarily removed from the outer peripheral surface of the rotor 6. It is designed to distinguish and detect the so-called blade flying phenomenon.

Inside the discrimination device 17, as shown in FIG.
9, a multiplexer 20 which selects and inputs one of the signals from each of the amplifiers 18 and 19 based on a command signal from the CPU 23 (described later), and an A/D interface which inputs the operating sound signal or the operating vibration signal from the multiplexer 20. an analyzer 22 that receives the signal through the face 21 and analyzes the frequency, and the analyzer 2
The CPU 23 receives the frequency-analyzed driving sound signal or driving vibration signal from 2.
The CPU 23 operates based on the operation flow shown in FIG. 5, and outputs an abnormal operation signal when the blade 8 of the compression section 3 flies off.
An abnormality detection relay RY is connected to the CPU 23, which turns on when the abnormal operation signal is received through the I/O port 24, and the abnormality detection relay RY is connected to the abnormality detection relay RY, which turns on when the abnormality detection relay RY turns on. An operational abnormality display lamp 25 that lights up is connected. Further, a model setting device 26 is connected to the CPU 23 via the I/O port 24, and the model of the rotary compressor A is selected and set by the operator. A ROM 27 and a RAM 28 are connected to input and store a plurality of aperiodic degrees Smax corresponding to the occurrence of a blade flying phenomenon set for each time.

Next, the operation flow of the CPU 23 shown in FIG. 5 will be explained. After starting, first, in step _S1 , the input level Lin of the operating sound signal or operating vibration signal is adjusted so that the measurement start point is at the approximate discharge start level L _B as shown in the waveform of Fig. 6. Compare the size with the measurement start level L _A shown in , and find that Lin>L _A.
Wait for YES and initialize the period measurement time t to "0" in step _S2 , then proceed to step _S3.
Compare the cycle measurement time t with a predetermined time t ₀ shorter than the discharge start cycle D in the same figure, and find out that t≧t ₀ .
Wait until it becomes YES and set the input level in step _S4 .
Wait for Lin to reach the discharge start level L _B.

Then, in order to measure the cycle a predetermined number of times when the input level Lin exceeds the discharge start level L _B in step _S4 , the number of cycle measurements i is initialized to "0" in step _S5 , and then At _{step 6} , the cycle measurement time t is reset to "0" and "1" is added to the cycle measurement number i. After that, in step _S7 , the cycle measurement time t is compared in magnitude with a predetermined time _t0 , and after waiting for t≧ _t0 (YES), in step _S8 , the input level Lin is compared in magnitude with the discharge start level _LB. , when Lin>L _B becomes YES, the value of the period measurement time t is stored in the period array D[i] in step _S9 . Next, in step _S10 , it is determined whether the number of cycle measurements i has reached a predetermined number n, and if i<n,
If NO, the process returns to step _S6 and the period measurement is repeated.

Thereafter, when the number of period measurements i reaches the predetermined number n in step _S10 , the calculation number counter J is started in step _S11 to calculate the aperiodic degree (standard deviation).
After initializing to "0", in step _S12 , "1" is added to the calculation number counter J, the period array D[J] is added to the period total value D, and the period array D[J] is added to the period multiplication value DD. Square D of array D[J]
Add the multiplication results of [J]×D[J], then determine the number of times the above operation is repeated in step _S13 ,
If J<n is NO, repeat the operation in step _S12 , while if J≧n is YES, proceed to step _S14 , where _the standard deviation S is calculated using the following formula: S= √(−×(−1)) Then, in step _S15 , this standard deviation S is calculated as the ROM corresponding to when the blade flying phenomenon occurs.
The process is compared in size with the predetermined value Smax of 27, and if S<Smax, no blade flying phenomenon has occurred, the process ends immediately, while if S≧Smax, NO, where a blade flying phenomenon is occurring, In step _S16 , the operation abnormality signal is output to the abnormality detection relay RY, and the operation abnormality display lamp 25 is turned on to indicate the occurrence of the blade flying phenomenon, and the process ends.

Therefore, in the operation flow of the CPU 23 shown _{in FIG} . It constitutes a calculating means 30, and receives the output of the period calculating means 30 in steps _S11 to _S14 , and calculates the aperiodic value in the plurality of periods D[i] based on the period t of the driving sound or vibration. This constitutes an aperiodic degree calculating means 31 configured to calculate degrees, that is, standard deviation S. Also, step S ₁₅ ,
_S16 receives the output of the aperiodicity calculating means 31, and starts operation when the aperiodicity S is equal to or greater than a predetermined value Smax, which corresponds to the occurrence of a blade flying phenomenon, that is, the failure of the blade 8 to follow the rotor 6 of the compression section 3. Signal generating means 32 configured to generate an abnormal signal
It consists of

Therefore, in the above embodiment, the operating sound signal or operating vibration signal of the rotary compressor A detected by the noise sensor 15 or the vibration sensor 16 is as shown in FIG. While the repetition of the waveform is constant as shown in A,
In the case of a defective product that causes a blade flying phenomenon, the repetition of the waveform is not constant as shown in FIG. period D
When the non-periodic degree (standard deviation) S in [i] is calculated, in the case of the above-mentioned non-defective product, this aperiodic degree S is less than the predetermined value Smax, whereas in the case of a defective product, the aperiodic degree S is becomes larger than the predetermined value Smax, an abnormal operation signal is generated from the signal generating means 32, and the abnormal operation indicator lamp 25 lights up. It is possible to objectively and quantitatively automatically detect the occurrence of the skipping phenomenon of No. 8. In addition, since it is a simple configuration of calculating the degree of aperiodism, high-speed processing can be expected, and the predetermined value Smax of the degree of aperiodism, which serves as a criterion, can be flexibly set, making it highly practical.

Now, as shown in Figure 8, the number of period measurements N is 5.
When the non-periodic degree (standard deviation) S is calculated four times for a good product and five times for a defective product, the non-periodic degree S is less than 1 and the length of the period t is uniform for a good product. On the other hand, for defective products, the aperiodic degree S
is extremely large in the range of 5 to 23, and the length of the period t is non-uniform.This shows that according to the present invention, it is possible to accurately and reliably determine the occurrence of the blade flying phenomenon.

In the above embodiment, as the rotary compressor A,
Although the fixed blade type in which the tip of the blade 8 slides on the outer peripheral surface of the rotor 6 has been described, the present invention
The present invention can also be applied to a sliding blade type in which one or more blades are provided on the rotor side and the tips of the blades slide into contact with the inner peripheral surface of the cylinder according to the eccentric rotation of the rotor.

Further, although the driving abnormality display lamp 25 is turned on by the driving abnormality signal from the signal generating means 32, other abnormality expression modes such as sounding a warning buzzer may be adopted. Further, as the vibration sensor 16, in addition to the acceleration sensor, an eddy current detection type non-contact transducer, a speed transducer, etc. may be used.

(Effects of the Invention) As explained above, according to the present invention, the occurrence of the blade flying phenomenon of a rotary compressor can be automatically detected by calculating the non-periodicity of the period of the operating sound or operating vibration. As a result, it is possible to objectively and quantitatively automatically inspect abnormal operation due to the blade flying phenomenon, and it is also convenient in practice, as high-speed processing is possible and judgment criteria can be set flexibly.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of the present invention, Figs. 2 to 8 show embodiments of the invention, Fig. 2 is a cross-sectional plan view of the rotary compressor, and Fig. 3 is a longitudinal sectional front view of the same main part. ,
Figure 4 is a diagram showing the internal configuration of the discrimination device, and Figure 5 is a diagram showing the internal configuration of the discriminator.
Figure 6 is a flowchart showing the operation of the CPU, Figure 6 is a signal waveform diagram showing the basic waveform of operating noise or vibration, Figure 7 A and B are a non-defective product that does not cause the blade flying phenomenon and a defective product that does, respectively. FIG. 8 is a signal waveform diagram showing how the waveform of driving sound or driving vibration is repeated in FIG. A... Rotary compressor, 3... Compression section, 4... Cylindrical cylinder, 6... Rotor, 8... Blade, 15... Noise sensor, 16... Vibration sensor, 17... Discrimination device, 2
3...CPU, 30...Period calculation means, 31...Aperiodicity calculation means, 32...Signal generation means.

Claims (1)

[Claims] 1 Operation of a rotary compressor A in which the volume of a space formed by a cylinder 4 and a rotor 6 that rotates eccentrically within the cylinder 4 is changed by blades 8 that come and go in response to the eccentric rotation of the rotor 6. The inspection device includes detecting means 15 and 16 for detecting operating noise or operating vibration of the rotary compressor A, and a period for receiving the outputs of the detecting means 15 and 16 and calculating the cycle of the operating noise or operating vibration. a calculation means 30; an aperiodicity calculation means 31 that receives the output of the periodicity calculation means 30 and calculates the aperiodicity S in a plurality of periods based on the period of driving noise or vibration; and the aperiodicity calculation means 31 and a signal generating means 32 which generates an abnormal operation signal when the non-periodicity S is equal to or greater than a predetermined value Smax.