JPH03246472A - Winding abnormality detecting device for winding coil for motor - Google Patents

Abstract

PURPOSE:To easily detect a winding defective by applying an AC voltage within a specific range between the winding coil and an iron core and deciding the charge extent of discharging. CONSTITUTION:A body 10 to be tested is constituted by winding the iron core with the stator or rotor coil of a low-voltage, small-sized motor and when a switch SW2 is turned on with the signal from an inspection start switch SW1, a specific voltage is applied between the winding coil and iron core of the body 10 be tested through a slide voltage regulator SVR and a transformer T. At the same time, a measurement start signal is outputted to a corona meas uring instrument 1, which inputs information on discharged charges of the body 10 to be tested and output pulses of a pulse generator 3 through an input unit 2 and outputs data on the V-q characteristic and discharging start voltage of the body 10 to be tested to a quality decision circuit 5. The circuit 5 decides a winding defective which increases abruptly in discharged charges when a 800 - 1,100V AC voltage is applied according to the criterion of a decision value setting device 6.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to low-voltage small motors (100 to 200 V, 10 to 1
kW), the winding of the coil wrapped around the iron core is automatically inspected for defects.In particular, a discharge test is performed using a corona discharge tester, and a part of the coil is tested to detect defects within 1 am+ of the iron core. The present invention relates to a winding abnormality detection device for a motor winding coil that is capable of detecting a state in which the motor winding coil is approaching.

(Prior technology) When manufacturing low-voltage small motors used in home appliances, etc., normally a winding coil such as enameled wire is automatically wound around the iron core of the stator, and a rotor is mounted inside the stator. and configure the motor.

In the above-mentioned motor, a test line is provided after the stator winding process, and a visual inspection, a pressure test, etc. are performed to check for abnormalities in the winding of the winding.

For example, winding abnormalities in low-voltage small motors are caused by disturbances in the coil, bumps in the wire, and misalignment of the wedge (spacer). , and may hang very close to the iron core.

The above-mentioned disturbance of the coil occurs, for example, in the state shown in Figs. 3 to 3b, in which the hanging portion of the coil C comes into direct contact with the iron core t as shown in Fig. 3. Or, as shown in Fig. 3a, the coil C protrudes from the spacer S and comes into contact with the iron core t, or as shown in Fig. 3b, the coil C protrudes from the groove of the iron core. It appears in various conditions such as direct contact with the iron core.

As mentioned above, the state in which the coil is in direct contact with the iron core can be detected by visual inspection, and a defective product can easily be determined by a withstand voltage test that applies a voltage of about 2 kV. It is said that products with winding coil abnormalities will not be shipped as products.

(Problem to be Solved by the Invention) However, according to the conventional detection method described above, even if the disordered part of the coil due to poor winding as described above is not in direct contact with the iron core, it can be detected that it is only in one layer. If they are close to each other, if you perform a pressure test on the motor after combining the stator and rotor to form a motor, problems may occur such as the disordered parts of the coils short-circuiting and destroying the motor. .

Therefore, according to the conventional testing method, even a motor that is shipped as a good product may turn out to be a defective product that cannot be actually used, resulting in serious problems on the motor manufacturing side, such as reduced product reliability.

In addition, home appliance manufacturers are forced to perform extra work, such as removing a motor that has been installed in a device from a home appliance, and then reinstalling a different motor into the device. Problems also arise in terms of the manufacturing cost of the device.

However, in the manufacturing process of small motors, only inspections such as visual inspections and pressure tests as mentioned above can be applied, and the use of other testing methods is not considered and can be easily applied. The development of a suitable testing device was long awaited.

In response to this, it has been considered to use a partial discharge charge amount display device as shown in, for example, Japanese Patent Publication No. 63-31056.

However, the device shown in the above-mentioned conventional example is used to detect voids and voltage-resistant weak points in the internal insulator in large devices such as transformers, and the test voltage is extremely high. Therefore, there are many problems in applying it to a small motor.

Furthermore, the conventional device described above, such as a small motor,
When applying a low voltage of about 1000 V, it is difficult to obtain good measurement values, and the inspection time for one piece is about 10
There is a drawback that it cannot be applied to a production line that is limited to about seconds.

(Objective of the Invention) The present invention is intended to eliminate the drawbacks of conventionally used devices as described above, and is capable of easily detecting the approaching state of coils of about 11I11, which could not be detected by conventional pressure tests. To provide a device that can easily eliminate products with defects, as well as to greatly improve detection accuracy and efficiency, and to easily detect defective coil winding products. is intended to provide.

(Means and effects for solving the problems) The present invention provides a specimen in which a coil such as enameled wire constituting the stator or rotor of a low-voltage small motor is wound around an iron core, and a coil and an iron core in the specimen. This device is equipped with a corona measuring device that measures corona discharge during the corona measuring device, and a quality determining means that determines whether the coil winding state is good or bad, which is provided in the output side circuit of the corona measuring device.

The quality of the specimen in the device of the present invention is determined by determining that the specimen exhibits a discharge charge of 2000 pC (picocoulomb) or more when an AC voltage of 800 V to 1100 V is applied between the iron core of the winding coil and the wound coil as defective. It can be configured to discriminate.

The detection method of the present invention uses a corona discharge test device, which was not considered to be applicable in the past.
By using this method as a new means for testing abnormalities in the winding of coils in low-voltage small motors, defects in coil winding can be accurately detected even in specimens that could not be detected in pressure tests, etc. .

Therefore, the detection device of the present invention can reliably detect defective products and improve product reliability, especially when the coil is close to the iron core within 1alX due to coil disturbance etc. I can do it.

Further, in the winding abnormality detection device for a motor winding coil of the present invention, the applied voltage between the coil and the iron core is set in the range of 800V to 1100V, and the discharge charge obtained thereby is 2000 pC or less. By determining that a product is a good product, it is possible to prevent problems from occurring after it is incorporated into a device as a motor.

(Example) A winding abnormality detection device for a motor winding coil according to the present invention will be described according to an illustrated example. The winding abnormality detection device for motor winding coils of the present invention is applicable to low-voltage small motors (100 to 2
00ν, 100- to 1-), a winding defect is detected.

In addition, the device of the present invention detects coil winding abnormalities such as a state in which the winding coil of the low-voltage small motor is in contact with the iron core or approaches within 1W, and automatically rejects defective products. We are trying to make sure that it can be eliminated.

The embodiment shown in FIG. 1 is a block diagram showing the configuration of a device used for detecting abnormal winding of a motor winding coil according to the present invention. Connected to the application circuit.

A voltage application circuit for the specimen to which the input crab unit 2 is connected includes a switch SW2 and a sliding voltage regulator 5VR1.
The circuit is composed of a transformer T1, a blocking coil L1, and a coupling capacitor Ck, and the specimen 10 is connected to the circuit, and a predetermined voltage is applied to the circuit.

The specimen 10 is sequentially conveyed on a conveyor provided along the motor inspection line, and a corona discharge test is performed on the way. It is now connected.

Further, the test start signal for the specimen is turned on by a signal from the test start switch Sw1 provided in the motor test line, and switch SW2 is turned on, and at the same time, a measurement start signal for the corona measuring device 1 is output.

The corona measuring device 1 measures the partial discharge in the specimen 10 using the information on the discharge charge of the specimen inputted through the input crab unit 2 and the pulses output from the pulse generator 3. and the resulting V-
Obtain data on q characteristics and 08V (discharge starting voltage),
The data is outputted to the pass/fail judgment circuit 5.

A quality determination circuit 5 connected to the output side circuit of the corona measuring device 1 determines whether the motor is good or defective based on the output value from the corona measuring device 1. The reference value for this determination is as follows. , is configured to be variable by a judgment value setting device @6.

Then, the quality of the motor is determined as described above, and the output value is distributed to the conveyor line and given as an operation signal to the robot 7, and is conveyed along the test line by the quality determination circuit 7. The resulting test specimens are sorted and transferred to the non-defective product line 11 and the defective product line 12.

Using the inspection means of the present invention configured as described above,
Figure 2 shows the results of a corona discharge test between the motor coil and the iron core.

In the graph shown in Figure 2, ■ indicates the case of a good product;
■ indicates the case where the coil is in contact with the iron core, and ■ indicates the data when the hanging portion of the coil is close to the iron core by about 1#.

As shown in the above graph, when the motor as a specimen is a good product, the discharge charge increases rapidly when a voltage of 1200V or more is applied, but in the case of
The discharge charge increases rapidly from the stage where the voltage exceeds 0V.

In addition, in the case of ■, when a voltage of 700V or more is applied, the discharge charge increases rapidly, and in the cases of ■ and ■ above,
In both cases, when the applied voltage exceeds 800μ, the discharge charge increases by 20μ
It was found that the temperature exceeded 00 pC.

In other words, according to the winding abnormality detection device for motor winding coils of the present invention, if the coil is close to the iron core within one shoe, a defective product can be determined with an applied voltage of about 800 V. In the conventional motor inspection process, good results can be obtained with a lower voltage than in the case of a withstand voltage test in which a voltage of 2000 V or more is applied.

As mentioned above, according to the inspection method of the present invention, if a part of the coil is close to the iron core of the motor within 1jll1, the test piece is judged based on, for example, 2000E)C. It will be a good thing if you do it.

On the other hand, when the distance between the two is within 21, the applied voltage is set to 1000 to 1100V and the reference discharge charge is set to, for example, 200CIC to distinguish between good and defective products. It will also be possible to do this.

As mentioned above, in the motor winding coil winding abnormality detection device of the present invention, the voltage applied between the coil and the iron core can be set between 800V and 11V depending on the type of motor and other conditions.
It can be set within the range of 00V. Then, it is possible to arbitrarily set a reference value for determining pass/fail for the value of the discharged charge obtained as a result, and to distinguish between good and defective products. It is possible to accurately detect defects caused by defects.

Furthermore, when using the method of the present invention, the corona measuring device incorporated in the inspection circuit can be used to detect coil disturbances in places where it is difficult to detect by normal visual inspection, such as coil disturbances inside the stator. This makes it easy to discover.

Furthermore, the inspection device of the present invention can be used in a motor inspection line.
As 6 to 8 motors are transported per minute, each specimen can be inspected sequentially, so the inspection can be carried out continuously without affecting the line speed.
This makes it possible to perform inspections efficiently.

In addition, the output value from the corona measuring device 1 is inputted to a device 7 for distributing robots, etc. via a pass/fail judgment circuit 5. In addition, a display section is provided at a predetermined location on the inspection line. In addition to displaying the judgment results of the inspected objects on the display section at the end of each inspection, the judgment data can also be stored in a computer and used for other purposes.

(Effects of the Invention) The winding abnormality detection device for motor winding coils of the present invention uses the corona discharge test device as described above,
By using a device that was previously unthinkable to be used as a means of inspecting defective motors, it is now possible to detect special specimens such as small, low-voltage motors that could not be detected by pressure tests, etc. , accurately check the winding disturbance, etc.
Moreover, it can be detected efficiently.

Therefore, the detection device of the present invention reliably detects abnormal winding of the coil as a defective product, especially when the coil approaches the iron core within 1 inch due to coil disturbance etc. It is possible to improve the reliability of the product.

In addition, in the winding abnormality detection device for a winding coil for a low-voltage small motor of the present invention, the AC voltage applied between the coil and the iron core is set in the range of 500V to 1100V, and the discharge charge obtained thereby is set. , 2000 pC or less as a good product, it is possible to prevent problems from occurring after the motor is incorporated into a device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an inspection circuit used for detecting a winding defect in a low-voltage small motor according to the present invention, FIG. 2 is a graph of applied voltage versus discharge charge obtained in the apparatus of the present invention, and FIG.
FIG. 3a and FIG. 3b are explanatory diagrams each showing a defective state of the winding. Code 1 in the figure: corona measuring device, 3: pulse generator, pass/fail judgment circuit, 7: robot, 1... ...Specimen.

Claims (1)

[Claims] A specimen consisting of a coil such as enameled wire wrapped around an iron core that forms the stator or rotor of a small low-voltage motor;
A corona measuring device for measuring corona discharge between a winding coil and an iron core in a specimen, and a quality determining means for determining the quality of the coil winding state provided in the output side circuit of the corona measuring device, The test piece is judged to be defective if it shows a discharge charge of 2000 pC or more when an AC voltage of 800V to 1100V is applied between it and the iron core of the winding coil. A winding abnormality detection device for a motor winding coil.