JPH0376713B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for determining the quality of various coils such as electromagnetic valve coils, motor coils, generator coils, transformers, etc., and particularly for detecting rare shoots (interlayer short circuits), incorrect wiring, etc. of various coils. The present invention relates to a determination device that can quickly and accurately determine a turn count error.

Conventionally, it is known that a Q meter is used to determine the quality of a coil. That is, when a capacitor is connected to the coil to be determined, the self-inductance of the coil is L, the resistance is R, and the capacitance of the capacitor is C, ωoL/R=1/
The determination was made by measuring the value of Q determined by ωoCR. However, in the conventional method using a Q meter, it is not easy to determine the occurrence of defects such as rare shoots and turn count errors based on the measured Q value, and the current method is to rely on the intuition of the measurer. However, the disadvantages were that quick and accurate judgments could not be expected, and the efficiency of the judgment work was poor. Furthermore, in recent years, coil scopes have come into use, and these coil scopes visually compare the transient response characteristics of a good coil and the coil to be measured by displaying an image on the scope surface. However, when determining the quality of the coil, in addition to the coil to be determined,
It is necessary to select and connect good coils each time, and the judgment work is not only cumbersome, but also to judge the quality by visual inspection. There were also problems in which it was not possible to determine whether the product was good or not, resulting in poor work efficiency.

In view of the above circumstances, the present invention makes it possible to directly read the determination results of coil quality by effectively applying microcomputers, which have come to be used in various fields in recent years, and which requires no skill. It is an object of the present invention to provide a determination device for various coils that can perform quick and accurate determination without causing problems, and can improve work efficiency.

In order to achieve the above object, the present invention includes a surge voltage generation circuit that supplies a surge voltage to a coil to be determined, and a microcomputer in which an ideal transient response waveform of the coil is digitally encoded and stored in advance. The microcomputer digitally encodes the transient response waveform generated in the coil to be determined by application of the surge voltage, and then performs a comparison operation with the digital code of the ideal transient response waveform of the coil stored in advance. The present invention is characterized by a determination device for various coils that outputs calculation results.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a determination device for various coils according to the present invention will be described below with reference to the drawings. First, if we explain the principle of the determination device with reference to Figures 1 and 2,
As shown in FIG. 1, the coil _LX to be determined has a self-inductance _L1 and a resistance _R1 ,
A capacitor C _S with a known capacitance including stray capacitance is added, and a discharge capacitor C ₀ is connected to the circuit via a switch SW ₁ . A predetermined voltage E _S is charged to the capacitor C ₀ in advance.
Then, when switch SW ₁ is turned on, the capacitor
The voltage E _S of C ₀ passes through the switch SW ₁ and the capacitor
The voltage is applied to _CS and coil _LX , and a transient response voltage waveform as shown in FIG. 2 is generated across the coil _LX . The coil L _X and capacitor C _S are R ₁ ² <4L ₁
<C _S If the condition is satisfied and it is oscillatory, the oscillation frequency f of the transient response voltage waveform in Fig. 2 is f≒1/
2π√ _{1 S.} Also, in Figure 2, if we take the ratio of the peak values of adjacent wave heights, we get E ₂ /E ₁ =
E ₃ /E ₂ = e−π/2Q. However, Q=ωL ₁ /R ₁ . Therefore, Q and inductance _L1 can be determined from the transient response waveform, and it is possible to determine whether the coil _LX is good or bad. For example, when the number of turns is different for a predetermined number of turns, so-called a difference in the number of turns, the vibration frequency f changes for a coil with a predetermined number of turns because the inductance _L1 is different. Coil _L
When L is in a rare shoot, not only the inductance changes but also energy loss occurs within the coil _LX , so the transient response waveform changes significantly. In other words, by observing the transient response waveform, it is possible to determine whether the coil _LX is a good product.

The present invention utilizes the above principle, and the third
As shown in the figure, a surge voltage generation circuit ₁ is connected to the coil _L A memory 2 is connected, and a microcomputer 3 performs a comparison operation between the digitally encoded transient response voltage waveform and the digitally encoded transient response voltage waveform of an ideal non-defective coil, and outputs the result of the operation. I'm starting to do that. The digital memory 2 used is one built into the microcomputer 3, and it goes without saying that a capacitor _CS as shown in FIG. 1 is connected to the coil _LX . As shown in FIG. 4, the digital memory 2 plots and digitally encodes a predetermined number of transient response voltage waveforms, for example, 50 comparison points, and stores the digital codes. On the other hand, the microcomputer 3 also stores in advance the digitally encoded transient response voltage waveform of the ideal coil, and also in the digital encoding, the transient response voltage waveform of the coil _L Of course, during encoding, the transient response voltage waveform can be plotted at the same time on the time axis (horizontal axis) as shown in FIG. 4 and digitally encoded. To store the digitally encoded transient response voltage waveform of an ideal coil in a microcomputer, it is sufficient to connect a good coil in place of the coil _L It is also possible to measure the transient response voltage waveform of the coil and store the average value internally. The microcomputer 3 compares and calculates the transient response voltage waveform of the ideal coil and the transient response voltage waveform of the coil _L
In addition to displaying the calculation result on a display device, it is also printed out on a printer, and furthermore, the transient response voltage waveform of the ideal coil and the transient response voltage waveform of the coil _L
(cathode-ray-tube), so that judgment can be made directly. The transient response voltage waveform W _O of the ideal good coil shown in Fig. 4 above
If the transient response voltage waveform of the coil _L .

To explain this in detail based on the circuit diagram shown in FIG.
1, 12, the signal is input to an analog-to-digital converter circuit (hereinafter referred to as A/D converter circuit) 14 via a signal hold circuit 13, and the A/D converter circuit 14 plots a predetermined number of transient response waveforms. After converting it into a digital signal, the buffer circuit 15
The data is stored at a predetermined address in a random access memory (hereinafter referred to as RAM) via a setter 16, and the allowable width T of the upper and lower limits is set by a setter 16.
The plot number is from oscillator 17 to AND gate 18
The division ratio of the oscillation frequency input via the switch _SW5 can be freely set.
The frequency divided signal from the frequency dividing circuit 19 is passed through the one-shot multivibrator 20 to the A/D conversion circuit 14.
is input. The digitally encoded transient response voltage waveform of this ideal good coil is stored in RAM.
The method for storing it in the coil to be determined is described later.
This is the same as when storing the transient response voltage waveform of _LX in RAM, only the address to be stored in RAM is different.

Next, to determine the quality of the coil _L
An operation start signal is sent from lines 21 and 22 to flip-flops 25 to 2 via OR gates 23 and 24.
7 and counters 28 and 29 to operate the flip-flops 25 to 27 and counters 28 and 29. It is also input to counter 32 from line 30 through OR gate 31 to prepare the counter 32 for operation. Moreover, although not shown, the RAM and the counter 32 receive a reset signal, and the transient response voltage waveform of the coil _LX stored in the RAM during the previous judgment operation is erased.
The contents of the counter 32 are also erased. Next, when the operation signal is inputted from the operation signal generation circuit 33 to the OR gate 34, it is inputted to the OR gate 35 via the flip-flops 26 and 27. The operation signal input to the OR gate 35 is
It is supplied to the frequency dividing circuit 19 via the inverter 38 to set it to be operable, and also to set the frequency dividing circuit 19 to be operable.
8 is opened, and the output of the oscillator 17 is connected to the AND gate 18.
The signal is supplied to the A/D conversion circuit 14 via the frequency dividing circuit 18 and the one-shot multivibrator 20. Therefore, the A/D conversion circuit 14 converts the transient response voltage waveform of the coil _L
A predetermined number of signals are plotted and digitally encoded as shown in FIG. The digital signal is transmitted to the data bus 39 and the buffer circuit 15.
After that, it is temporarily stored in RAM. Then the RAM
Data bus 39 from inside via buffer circuit 15
Then, the adder 40 and the subtracter 41 add the digital signal of the ideal transient response voltage waveform of the coil and the allowable width T to calculate the upper limit value for a good product. By subtracting the allowable width T from the digital signal, the lower limit value is calculated as a non-defective product. As a result, a permissible width T having upper and lower limits is calculated. In other words, even if the number of turns is the same as that of an ideal good coil and there are no defects such as rare shoot, the difference in resistance will result in a transient response voltage waveform that is slightly different from the ideal transient response voltage waveform. Since it is not preferable that even the coil _L The results of each operation of the adder 40 and subtracter 41 are provided to comparison circuits 42 and 43, respectively. A digitally encoded transient response voltage waveform of the coil _LX to be determined is also input from the RAM to each comparison circuit 42, 43 via a data bus 44.
Therefore, each comparison circuit 42, 43 compares the calculation results of adder 40 and subtracter 41 with the digitally encoded transient response voltage waveform of coil _LX to be determined. The comparison value is input to the counter 28 via the OR gate 45 and flip-flop 46,
At the same time when each counter 28, 29 is set to be operable, the counter 28, 29 is set to be operable.
9, the counters 28 and 29 count the number of times the digitally encoded transient response voltage waveform of the coil _L Donate to. After the operation start signal is input to the flip-flop 25, the operation signal is input from the OR gate 35 via the one-shot multivibrator 50 and the OR gate 23, and the flip-flop 25 maintains the operation state, and the operation of the adder 40 and the subtracter 41 is maintained. The result is inputted through the OR gate 51, and the various states of the coil _LX are displayed on the display device 52 based on the calculated results and the counts of the counters 28 and 29. That is, when the plotted points of the digitally encoded transient response voltage waveform of _the coil _L In the entire judgment process of the digitally encoded transient response voltage waveform of the coil _L In this case, the light emitting diode _D2 emits light to display an image. When either of the light emitting diodes D ₁ and D ₂ emits light, the light emitting diode D ₃ becomes a light emitting diode through the OR gate 53.
D ₃ is emitted and displayed, and the output terminal 54
The NG signal is output from the NG signal, and the above-mentioned determination operation is stopped. Or the above NG
A signal is sent to a discharge device built into the automatic coil manufacturing line to operate the discharge device, thereby discharging the defective coils measured as described above from the automatic coil manufacturing line. It's summery. Further, when an error occurs in the judgment operation, the light emitting diode _D4 emits light to display an indication. Furthermore, if a light emitting diode is provided that emits light depending on the manner in which the upper or lower limit is exceeded, the cause of the defective product can also be indicated. When the series of determination operations is completed, a termination signal is outputted from a termination circuit (not shown) or the one-shot multi-vibrator 69, and the flip-flop 25 receives the termination signal and causes the light emitting diode _D5 to emit light for display. Furthermore,
The digitally encoded transient response voltage waveform of the coil _L The resulting transient response voltage waveform is also
From RAM to buffer circuit 15 and data bus 5
8, the signal is further supplied to the CRT via a latch circuit 59 and an output circuit 60. Therefore, the CRT simultaneously images the respective transient response voltage waveforms, making it possible to directly read whether the coil _LX is good or not. A level sensitivity adjustment circuit 61 is interposed in the flip-flop 27, and the level sensitivity adjustment circuit 61 includes a variable resistor for level adjustment.
A comparator circuit 62 equipped with VR ₁ and a slave selection switch SW ₂ incorporating an inverter 63 generate a level sense trigger pulse. Inverter 63 and throttle selection switch SW ₂
This is to select when the starting point of the transient response voltage waveform of the coil _LX to be determined starts from a rising edge or when it starts from a falling edge. A delay circuit 64 and a flip-flop 65 are interposed between the flip-flop 26 and the OR gate 35, and the delay circuit 64 and flip-flop 65 control the circuit operation between each circuit such as the A/D conversion circuit 14 and RAM. In order to stabilize the
This is for opening the OR gate 35 with a delay from the time when the operation signal is input to the OR gate 34. The AND gate 36 has an A/D conversion circuit 1
A signal is supplied from the coil _L The data is plotted with a certain time relationship, and the time cycle operation when writing or reading data to/from the RAM is controlled in accordance with digital encoding.
Each time a signal is input to the RAM, the contents of the RAM are sequentially written or read, and the operation of supplying the contents of the counter 32 to the RAM is controlled. Writing to and reading from the RAM is performed by inputting write and read signals output from a control circuit (not shown) to line 78. The write and read signals are also input to the buffer circuit 15, so that the signal transmission direction of the buffer circuit 15 is controlled.
The output signal of the AND circuit 36 is ANDed via a delay circuit 70 and a one-shot multivibrator 71.
It is input to gate 47 to open AND gate 47 in order to time the comparison operations of comparison circuits 42 and 43, and to operate flip-flop 46. Further, an offset switch circuit 72 is interposed in the adder 40 and the subtracter 41 so that the output value becomes zero when the respective inputs are zero. The flip-flop 26,2
7, 65 and the counters 28, 29 are reset by receiving a termination signal from the one-shot multivibrator 69 via the OR gate 24 when a series of determination operations are completed.

External start switch circuits 73 and 74 are interposed in the flip-flops 26 and 27 so that they can be manually operated from the outside. That is, the external start switch circuit 73 is connected to the flip-flop 26 via the pulse code oscillation circuit 75 and the OR circuit 34, and the external start switch circuit 74 is connected to the pulse code generation circuit 76, the one-shot multivibrator 77, and the internal automatic operation. A flip-flop 27 is connected via an external manually operated changeover switch _SW3 . The external start switch circuit 73 and pulse code generation circuit 75 have the same functions as the operation signal generation circuit 33, and the external start switch circuit 74, pulse code generation circuit 76, and one-shot multivibrator 77 function as the level sensitivity adjustment circuit. It exhibits the same function as 61.
Note that VR ₃ is used to vary the level value output from the amplifier 12.

Next, as shown in FIGS. 6 to 9, the state in which the defective coil _L
0 is the ideal transient response voltage waveform of a good coil. Furthermore, in FIGS. 6 to 9, the vertical axis represents voltage and the horizontal axis represents time, similarly to FIGS. 2 and 4. If the coil _L
A transient response voltage waveform appears within. If the coil _L
As shown in the figure, the voltage level of the transient response voltage waveform 81 of the coil _LX to be determined is lower than that of the transient response voltage waveform 80, and the period of the transient response is short, that is, the vibration frequency is high. When the number of windings is different, as shown at 82 in FIG. 7, the vibration frequency of the transient response changes due to the difference in self-inductance. For example, when the number of turns is large, the vibration frequency becomes low. Also, if there is a short circuit between the terminals of the coil _L
When _LX is disconnected, as shown at 84 in Figure 9, only voltage appears between the terminals of coil _LX , and no current flows, resulting in an oscillating transient response.

In addition, the present invention uses the transient response waveform of the coil _L
Without storing it in RAM, it can be compared with that of a non-defective coil using the comparison circuits 42 and 43 as described above, and it can also be used as is for a withstand voltage test to determine the quality of the coil _L. By determining the waveform as described above, it is also possible to measure whether the welding condition is good or bad.

As described above, according to the determination device for various coils according to the present invention, the transient response waveform of the coil to be determined for defects such as rare shoot, difference in the number of turns, wire breakage, etc. of the various coils with respect to the reference waveform of the ideal coil. By digitally comparing and analyzing the
The peak value of the transient response waveform is ideal because it can automatically identify defective products and is ideal for incorporating into automatic manufacturing lines. Compared to methods that judge pass/fail based on the period and period, it is also possible to compare the part of the waveform from the peak of the transient response waveform to the zero crossing point, and in particular, it can be compared depending on various conditions such as winding resistance and winding condition. Transient response waveforms with different curvatures can also be taken in as pass/fail judgment elements, making it possible to judge the pass/fail of a coil with extremely high precision, and to fully satisfy recent demands for high quality. have

[Brief explanation of drawings]

The drawings show an embodiment of the determination device for various coils according to the present invention, FIG. 1 is a circuit diagram for explaining the principle of the determination device, FIG. 2 is a voltage waveform diagram of the transient response in FIG. 1, and FIG. 3 is a block diagram of the determination device of the present invention, FIG. 4 is a waveform diagram showing the plot state when the transient response voltage waveform obtained in FIG. 3 is digitally encoded, and FIG. The circuit diagrams of the determination device, FIGS. 6 to 9, are waveform diagrams on a CRT showing the defective state of the coil to be determined. L _X : Coil to be determined, L ₁ : Self-inductance of coil L _X , R ₁ : Resistance of coil L _X ,
C _O , C _S ... Capacitor, SW ₁ ... Switch, 1
...Surge voltage generation circuit, 2...Digital memory, 3...Microcomputer.

Claims (1)

[Claims] 1. A surge voltage generation circuit that supplies a surge voltage to the coil to be judged, and a value obtained by sampling at regular intervals a transient response waveform generated in the coil to be judged whether it is good or bad by supplying the surge voltage and converting it into a digital code, and the coil. a storage section that stores each value obtained by sampling the ideal transient response waveform at regular intervals and converting it into a digital code; and an upper limit value of the allowable range for the digital code value of the transient response waveform of the ideal coil in the storage section. and a lower limit value to calculate a reference value having an allowable range; and an adder/subtracter that calculates a reference value having an allowable range based on the ideal coil outputted from the adder/subtracter, and determining the acceptability of the above-mentioned storage unit. 1. A determination device for various coils, comprising a comparison circuit that compares and calculates a digital code value of a transient response waveform generated in a power coil, and an output section that outputs and displays the calculation result of the comparison circuit.