JPH07333309A - Magnetic characteristic measurement device - Google Patents

Abstract

PURPOSE:To discriminate nondefective and defective goods at a step of core, by, in the state where d.c. current is made to flow through a coil wound around a magnetic path wherein a core is inserted into a gap for magnetic characteristic measurement, measuring inductance, for measuring a dc current redundancy characteristic of care. CONSTITUTION:In the state where a dc power source 4 makes dc current I flow through a coil 3 wound around a magnetic path 2 wherein a core 1 is inserted in a gap for magnetic characteristic measurement, inductance L is measured with a measurement equipment 5. A controller 6 calculates dc current I' and inductance L' of the core 1 based on the measured dc current I and inductance L, and then measures dc current redundancy characteristic of the core 1. The controller 6 considers, based on the dc current I' and inductance L' of core 1 calculated or the inductance L' when the dc current I' is assumed 1, the core 1 as good when they are within a specified range, and not good when outside of the specified range, or otherwise, the core 1 is selected for each specified range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic characteristic measuring device for measuring the magnetic characteristic of the core itself and determining whether it is a good product or a defective product.

[0002]

2. Description of the Related Art Conventionally, a ferrite core is wound to complete a choke coil or a transformer, and the magnetic characteristics of this finished product are measured to determine whether the product is a good product or a defective product.

[0003]

As described above, conventionally, in order to obtain the DC superimposition characteristics of the choke coil and the coil of the transformer, it is necessary to measure the finished product and then measure it to determine whether it is a good product or a defective product. When it is determined that the product is defective, there is a problem that the existing windings are wasted and cannot be manufactured efficiently. For this reason, it is desirable to find the good and defective products at an early stage by obtaining the DC superposition characteristics and coil characteristics at the stage of the core before applying windings, etc. It is rare.

The present invention solves these problems.
By measuring the DC superimposition characteristics of the core, the good / defective product can be discriminated and selected at the core stage, and I'and L'when further wound can be calculated to determine the good / defective product at the core stage. The purpose is to discriminate and to repair at the core stage by increasing or decreasing the number of turns when defective.

[0005]

FIG. 1 is a block diagram showing the principle of the present invention. In FIG. 1, a core 1 is a core whose DC superposition characteristics and the like are measured.

The magnetic path 2 is equivalent to winding a coil 3 and flowing a magnetic flux through a core 1 inserted in a gap for measuring magnetic characteristics, so that a coil is artificially wound around the core 1.
The coil 3 is wound around the magnetic path 2 to flow an electric current to generate a magnetic flux and to measure the inductance at that time.

The DC power supply 4 supplies a predetermined DC current I to the coil 3. The measuring device 5 measures the inductance L in the state where the direct current I is passed through the coil 3, and is, for example, an LCR meter.

The controller 6 controls the entire system and performs various calculations. Shape database 7
Is a database in which various shapes of the core 1 are registered.
The material database 8 is a database in which various materials of the core 1 are registered.

The function decision matrix 9 decides a function based on the shape and the material. Function database 10
Is a database in which the estimation function is registered. The core characteristic data 11 stores the characteristic data of the core 1.

[0010]

In the present invention, as shown in FIG. 1, a DC power source 4 supplies a DC current I to a coil 3 wound around a magnetic path 2 in which a core 1 is inserted in a magnetic characteristic measuring gap, and a DC current I is passed through the measuring instrument. 5 measures the inductance L at that time, and the controller 6
Calculates the DC current I ′ and the inductance L ′ of the core 1 based on the measured DC current I and the inductance L, and measures the DC superposition characteristic of the core 1.

Regarding the calculated DC current I'and the inductance L'of the core 1 or the inductance L'when the DC current I'is set to 1,
The core 1 is determined to be non-defective when it is within the predetermined range, and the core 1 is determined to be defective when it is out of the predetermined range, or the core 1 is selected for each predetermined range.

Further, the direct current I and the inductance L measured by the controller 6 are substituted into the estimation function 12 in consideration of the number of turns of the core 1 to obtain the direct current I'and the inductance L'of the core 1, and the obtained direct current I When I'and the inductance L'are within the predetermined range, it is determined that the number of coil turns is good,
At other times, the number of coil turns is incremented by +1 or -1 and the re-obtained DC current I'and the inductance L'are determined to be good when the number of coil turns is not within a predetermined range. Otherwise, the predetermined number of turns is not exceeded. Sometimes, this is repeated, and on the other hand, when the number of times exceeds a predetermined number, it is determined as a defect.

At this time, as the estimation function 12 considering the number of turns of the core 1, the corresponding estimation function 12 is selected from the function database 10 based on the input shape, material and number of turns of the core 1.

Therefore, the direct current superposition characteristics of the core 1 are measured to discriminate good products / defective products at the stage of the core 1 and to select, and I'and L'when further wound are calculated to obtain good products / good products. It has become possible to discriminate defective products at the core 1 stage, and to remedy at the core 1 stage by increasing or decreasing the number of turns when defective.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the construction and operation of an embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 2 shows a flow chart for judging a non-defective product / defective product of the present invention. In FIG. 2, S1 inputs a specified current. For this, the operator inputs a specified DC superimposed current I ₀ by keying.

In S2, the upper limit is set. This is set by inputting the upper limit value L _u of the inductance of the core 1 when the operator applies the specified DC superimposed current I ₀ . S
3 sets the lower limit. This configuration by entering the lower limit value L _l of the inductance of the core 1 when the operator flowing DC bias current I ₀ of the provision.

S4 is I₀Calculate the calculated value in. this
Is the DC superimposed current I defined in S1.₀When you throw
Inductance L of core 1_I0To calculate. this is,
Under the configuration of FIG. 1, the DC current I of various values is applied to the coil 3.
Measure the inductance L when flowing
Based on these measured I and L, DC weight for core 1 only
The tatami current I'and the inductance L'at that time are obtained in advance.
The inductance of core 1 is calibrated by the coefficient
L_I0Is calculated (inductance L where I ′ is 1) _I0To
calculate).

[0019] S5 is, L _'I0> L _u or discrimination. In the case of YES, the calculated inductance L' _I0 of the core 1 is S
Greater than the upper limit value L _u set in 2, because it is out of range, it is determined that NG (core 1 defective). On the other hand, if NO, the process proceeds to S6.

[0020] S6 is, L _'I0 or to determine _{<L l.} In the case of YES, the calculated inductance L' _I0 of the core 1 is S
Since it is smaller than the lower limit value L ₁ set in 3 and is out of the range, it is determined to be NG (core 1 is a defective product). On the other hand, in the case of NO, it is found that the inductance L _I0 is within the range between the upper limit and the lower limit, so the core 1 is determined to be a good product.

As described above, if the specified current I ₀ is designated, the DC superimposition current I of the core 1 measured by the configuration of FIG. 1 at that time and the actually measured inductance L at that time are calculated as follows.
Calibrated to I'and L'of core 1 only, and I'after this calibration
(Normalized to 1), when L'is within the specified upper and lower limits, the core 1 is determined to be a good product, and the rest is determined to be a defective product. It is possible to determine that the product is a good product or a defective product at the stage of the core 1 before being wound into a transformer or a choke coil. Further, in this flowchart, the non-defective product and the defective product are determined, but the cores 1 may be selected for each predetermined range based on the I ′ and L ′ of the core 1 itself at that time.

Next, the calculation of the core characteristic and the coil characteristic will be described in detail with reference to FIGS. 3 to 7. Figure 3
Shows a flowchart for explaining the operation of the present invention.

In FIG. 3, the operator inputs the material in S11. For example, enter Material: Ferrite as described on the right.

In S12, the operator inputs the shape.
For example, enter “Shape: Drum” as described on the right.

In S13, the operator inputs the number of turns.
For example, enter the number of turns: n as described on the right.

In step S14, the estimation function 12 is determined according to the conditions. This determines the corresponding estimation function 12 based on the material input in S11, the shape input in S12, and the number of turns n input in S13. To be more specific, (1) From the shape database 7 of FIG.
The shape data (D ₁ , D ₂ , H _1, etc.) corresponding to the shape, for example, “drum type” input in step S1 is extracted.

(2) The material input in S11 from the material database 8 of FIG. 4B, for example, "ferrite"
Retrieve the material data (μ ₀ etc.) corresponding to. (3) For example, based on the shape “drum type” and the material “ferrite” taken out in (1) and (2), refer to the function determination matrix 9 in FIG. Then, the "function" is determined.

(4) With respect to the function name "function" determined in (3), the function f having the function name is determined as the estimation function 12 from the function database 10 in FIG. 4 (d). Here, it is determined as shown below.

I ′ = a ₁ I + b ₁ + c ₁ L (Formula 1) L ′ = A ₁ I + B ₁ + C ₁ L (Formula 2) S15 measures the core characteristics. In the configuration of FIG. 1, various DC superimposed currents I flowing in the coil 3 and the inductance L at that time are measured with the core 1 inserted in the gap. These measured I and L
The set of is stored as a core characteristic data in a file.

In step S16, the coil characteristic is calculated. This is to calculate the coil characteristics by substituting the set of I and L of the core characteristic data measured in S15 into the estimation function 12 determined in S14, that is, the set of I and L of the measured core characteristic data,
I'and L'are calculated by substituting them into the estimation function 12 (Equation 1) and (Equation 2).

In step S17, the result is displayed. This is S1
The core characteristic data (set of I'and L ') calculated in 6 is displayed on the screen. Based on the above, the shape, material, and number of turns n of the core 1 are input, and the measured values of the DC superimposed current I and the inductance L at that time when the core 1 is inserted into the gap are the estimation function 12 (Equation 1). And (Equation 2)
It is possible to calculate the DC superimposed current I ′ and the inductance L ′ in consideration of the number of turns of itself. This will be specifically described below with reference to FIGS. 4 to 7.

FIG. 4 shows an explanatory diagram of the present invention. FIG. 4A shows an example of the shape database. The shape database 7 is a shape in which the shape is registered in advance in association with the shape name of the core 1, and is registered, for example, as shown below.

Shape name D ₁ mm D ₂ H ₁ drum type 10.0 2.0 12.0 FIG. 4B shows an example of a material database. The material database 8 is the one in which the characteristics of the material are registered in advance in association with the material name of the core 1. For example, the material database 8 is registered as shown below.

Material name μ ₀ Ferrite 500 (c) of FIG. 4 shows an example of a function decision matrix. This corresponds to the shape name registered in the shape database 7 of FIG. 4A, for example, “drum type”, and the material name registered in the material database 8 of FIG. 4B, for example, “ferrite”. Then, the function names used in these combinations are registered, and in the case of this combination, the "function" is registered as shown in the figure. Therefore, when the shape name and the material name are determined, the function name to be automatically used is uniquely determined by the function determination matrix 9.

FIG. 4D shows an example of the function database. This is a function f and the coefficients 1 to n at that time are preset in association with the function name. Here, for example, in the case of the function name “function”, it is registered as shown below.

Function name Coefficient 1 2 3 4 5 6 Function f Function a ₁ b ₁ c ₁ A ₁ B ₁ C ₁ I ′ = a ₁ I + b ₁ + c ₁ L L ′ = A ₁ I + B ₁ + C ₁ L FIG. An example of measurement data of the present invention is shown.

FIG. 5A shows a curve in which measured data are plotted. Here, the horizontal axis is based on the configuration of FIG.
The DC superimposed current I flowing through the coil 3 is shown, and the vertical axis shows the inductance L actually measured at that time. These are actually measured at the positions of ×.

FIG. 5B shows the measurement data. This represents the measured values of the current I flowing in the coil 3 of FIG. 1 and the inductance L at that time, and the plotted values are points x in the curve of FIG. 5A.

FIG. 6 shows a flowchart for calculating I ', L'of the core of the present invention. This is the measurement data I of FIG.
I ', L'of the core 1 itself is calculated from L, that is, I, L is added to the above-mentioned estimation functions (Equation 1) and (Equation 2).
Is a flowchart when I ′ and L ′ are calculated by substituting

In FIG. 6, in S21, i = 1 is initialized. In S22, the coil characteristics are calculated. this is,
As described on the right side, coil characteristics (I _i ', L _i ') = f (function name; function parameter material parameter shape parameter other parameters (number of turns, etc.) Core characteristic data (I _i , L _i ) Calculate I ', L'of 1 itself, that is,
For example, (Equation 1) and (Equation 2), which are the estimation functions 12 described above, are substituted with a pair of I and L to calculate I ′ and L ′.

In S23, i = i + 1 is set. In S24, it is determined whether it is the end. In the case of YES, the calculation to I ′, L ′ has been completed for all the sets of I, L, so the processing ends. On the other hand, in the case of NO, the calculation for the next set of I and L is repeated.

As described above, the I's and L'of the cores shown in FIG. 7 are substituted into the estimation function 12 (for example, (Equation 1) and (Equation 2)) based on the set of I and L actually measured in FIG. It becomes possible to calculate.

FIG. 7 shows examples I ', L'of the core of the present invention. This is an example of I ′ and L ′ of the core 1 calculated from the actual measurement data of FIG. 5 according to the flowchart of FIG.
FIG. 7A shows a curve in which the values of I ′ and L ′ of core 1 are plotted. The positions of × are the calculated I ′ and L ′ values. The horizontal axis represents the direct current I'estimated to flow through the core 1, and the vertical axis represents the estimated inductance L'of the core 1.

FIG. 7B shows the estimated I'of core 1,
The data example of L'is shown. Next, the creation of the correlation coefficient table will be described in detail with reference to FIGS. Figure 8
FIG. 7 shows a flowchart for creating a correlation coefficient table of the present invention.

In FIG. 8, S31 repeats S32 and S33 for all the samples (1 to N). S32 is
Measure the characteristics of the core only with a core characteristic measuring instrument.

In S33, the DC superposition characteristic of the coil is measured (measured by the configuration of FIG. 1). By the above S31 to S33, the characteristics of only the cores of the cores 1 of all the samples are measured by a core characteristics measuring device (not shown), and
That is, the characteristics are measured by the configuration of FIG.

S34 is a current I _core whose core characteristics are measured.
(1 to M). S35 is repeated for the current I _coil whose coil characteristics have been measured (1 to K). S3
6 is L _core VS L in each current combination
Determine the model function from the scatter plot of the _coil .

In step S37, the parameters of the model function are obtained. In S38, a correlation coefficient table is created. Above S34
From S38 to S38, the core characteristic data (corresponding to I'and L'described above) measured only in the core 1 in S31 to S33 and the coil characteristic data measured in the configuration of FIG. Corresponding) and the correlation coefficient table has been created.

FIG. 9 shows an example of core / coil characteristic data of the present invention. FIG. 9A shows an example of core characteristic data.
This is a schematic representation of the measurement data of the inductance L _core when the DC superimposed current I _{core is made} to flow alone in the core 1 of all the samples in S32 of FIG. Here, for the samples 1 to N, the inductance L _core is measured for each of the M sets of the DC superimposed currents I _{core 1} to I _{core M,} and is _tabulated .

FIG. 9B shows an example of coil characteristic data. This is a schematic representation of the measurement data of the inductance L _coil when the DC superimposed current I _coil is passed through the coils 3 of all the samples in S33 of FIG. 8 under the configuration of FIG. Here, for the samples 1 to N, the inductance L _coil is measured for each of the K sets of the DC superimposed currents I _{coil 1} to I _{coil k,} and is _tabulated .

FIG. 10 shows an example (actual measurement) of core / coil characteristic data of the present invention. This is an example of actually measured characteristic data when the number of samples is 16. FIG. 10A shows an example (actual measurement) of core characteristic data. This is an actual measurement example of (a) of FIG. 9, in which 16 pieces of Nos. 0 to F in the horizontal direction represent the numbers of the core 1 of the sample, and 1 to 9 in the vertical direction represent the current values shown. Represent A respectively. Then, the inductance L (μh) corresponding to each in the table is a measured value.

FIG. 10B shows an example (actual measurement) of core characteristic data. This is the actual measurement example of FIG. 9B,
Here, 16 numbers from No0 to F in the horizontal direction represent the numbers of the core 1 of the sample, and 1 to 26 in the vertical direction represent the illustrated current value A, respectively. Then, the inductance L (μh) corresponding to each in the table is a measured value.

FIG. 11 shows an example of a correlation coefficient table of the present invention.
This is an example of the core characteristic data shown in FIG.
11 is a correlation coefficient table between the coil characteristic data example (actual measurement) in FIG. This correlation coefficient is calculated as follows.

When I _{core m} and I _{coil k} In other words, the correlation coefficient r _mk is r _mk = (S _{core m coil k} ) / (S _{core m} · S _{coil k} ).
Calculated as ^1/2 .

The regression line at this time is expressed as L _{coil xk} = a + b · L _{core xm,} where a = average L _{coil k-} b average L _{core m} b = (S _{core m coil k} ) / S _{core m.} .

Here, L _{core xm} is the value of a certain sample measured by the core characteristic measuring instrument, and L _{coil xk} is the value of the estimated coil. Example 1: The calculation of the regression line when estimating the coil 0.84A from the core 0.18A will be described below.

From the data, the case of I _{core 5} and the case of I _{coil 17} are averaged so that the average L _{core 5} = 67.55 average L _{coil 17} = 766.21.

Further, the sum of squared deviations and the sum of products are: S _{core 5} = 6.13 S _{coil 17} = 88.27 S _{core 5 coil 17} = 19.65

Therefore, b = 3.21 a = 549.68 and L _{coil x17} = a + bL _{core x5} .

Example 2: Estimate the inductance of the coil at 0.84A. From the correlation coefficient table, the current value of the core characteristic having the highest correlation is obtained. From the correlation coefficient table of FIG. 11, the core characteristic of 0.18 A is maximum at the correlation coefficient r = 0.845.

Therefore, the coil characteristic at 0.84 A is estimated from the core characteristic at 0.18 A. The regression line at that time is as calculated above. Next, with reference to FIG. 12, the operation for repairing a defective product by increasing or decreasing the number of windings of the core will be described in detail.

FIG. 12 shows a defective product relief flowchart of the present invention. In FIG. 12, S41 inputs the specified current I ₀ . For this, the operator inputs a specified DC superimposed current I ₀ by keying.

In S42, the upper limit setting L _u is set. this is,
The upper limit value L _u of the inductance of the core 1 when the operator applies the specified direct current superimposed current I ₀ is set. In S43, the lower limit setting L ₁ is performed. This configuration by entering the lower limit value L _l of the inductance of the core 1 when the operator flowing DC bias current I ₀ of the provision.

In S44, the specified number of turns N is set. S4
5 sets other conditions. S46 is the maximum number of turns N
_{The max} and the minimum number of turns N _min are set.

In S47, S48 to S58 are repeated for each sample. In S48, n = N is initialized.
This initializes the number of turns n to the specified number of turns N.

In S49, the calculated value L' _IO at I ₀ is obtained. This determines the inductance L _'I0 obtained by calculation when a current of defined current I _0. S50 is L '
_{It is} determined whether _I0 > L _u . In the case of YES, the calculated L ′ _{I 0} is larger than the upper limit value _Lu and is out of the range. Therefore, the number of turns n is −1 in S54 and −1 in S55, and the number n of turns is N. When it is found that it is smaller than _min , N in S58
The process ends as G, and when it is found to be large, the process returns to S49 to recalculate. On the other hand, if NO in S50, S5
Go to 1.

[0067] S51 is, L _'I0 or to determine _{<L l.} YE
In the case of S, the calculated L ′ _{I 0} is smaller than the lower limit value L ₁ and is found to be out of the range.
Then, when it is found that the number of turns n after +1 in S57 is larger than N _max , the process ends as NG in S58, and when it is found to be small, the process returns to S49 and recalculates. On the other hand, S5
In the case of NO in S1, it is determined to be OK in S52, and the number of turns n is displayed in S53.

As described above, when the specified current I ₀ is set, based on the DC superimposed current I of the core 1 actually measured by the configuration of FIG. 1 and the actually measured inductance L at that time,
L ′ _IO of only core 1 is calculated, and when this L ′ _IO is within the set upper limit L _u and lower limit L _l , it is determined to be a good core 1, and otherwise, the number of turns n is +1 or -1 is set and the number of turns n is corrected until the number of turns is out of the range of the maximum number of turns N _max or the minimum number of turns N _min , and the defective product is remedied, whereby a coil is wound around the core 1 to complete a transformer or a choke coil. Even if the product is found to be defective at the previous stage of core 1, it can be remedied if it becomes a non-defective product by correcting the winding number n.

[0069]

As described above, according to the present invention,
A DC current I'and an inductance L'corresponding to the core 1 are calculated on the basis of the DC current I and the inductance L measured by inserting the core 1 into the gap for measuring the magnetic characteristics, and when they are within a predetermined range, they are non-defective products. , A defective product when it is out of the range, and a configuration in which the number of turns n is corrected and the defective product is relieved to a good product, therefore, the non-defective product / defective product of the core 1 is discriminated or selected at the stage of the core 1. Alternatively, I'and L'when further wound are calculated to determine a non-defective product / defective product at the core 1 stage, and when defective, the number of turns is increased / decreased to repair at the core 1 stage. I was able to do it.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is a flowchart for determining a non-defective product / defective product according to the present invention.

FIG. 3 is a flowchart for explaining the operation of the present invention.

FIG. 4 is an explanatory diagram of the present invention.

FIG. 5 is an example of measurement data of the present invention.

FIG. 6 is a flowchart for calculating I ′ and L ′ of the core of the present invention.

FIG. 7 is an example of I ′ and L ′ of the core of the present invention.

FIG. 8 is a flowchart for creating a correlation coefficient table of the present invention.

FIG. 9 is an example of core / coil characteristic data of the present invention.

FIG. 10: Example of core / coil characteristic data of the present invention (actual measurement)
Is.

FIG. 11 is an example of a correlation coefficient table of the present invention.

FIG. 12 is a defective product relief flowchart of the present invention.

[Explanation of symbols]

 1: Core 2: Magnetic path 3: Coil 4: DC power supply 5: Measuring instrument 6: Controller 7: Shape database (shape DB) 8: Material database (material DB) 9: Function determination matrix 10: Function database (function DB) 11: Core characteristic data 12: Estimating function

Claims (4)

[Claims] 1. A magnetic path (2) having a gap into which a core (1) to be measured is inserted, and a DC power supply (4) for supplying a DC current I by winding a coil (3) around the magnetic path (2). ) And a measuring instrument (5) for measuring the inductance L at that time, and a direct current I flowing by inserting the core (1) into the gap.
Based on the measured inductance L and the core (1)
And a controller (6) for calculating the DC current I'and the inductance L'or calculating the inductance L'when the DC current I'is 1. 2. The core (1) is regarded as a non-defective product when the calculated DC current I'and the inductance L'or the inductance L'when the DC current I'is set to 1, and the core (1) is out of the specified range. In addition, the controller (6) for discriminating the core (1) as a defective product, or selecting the inductance L'when the direct current I'and the inductance L'or the direct current I'is 1 in a predetermined range is provided. The magnetic characteristic measuring apparatus according to claim 1, wherein the magnetic characteristic measuring apparatus is a magnetic characteristic measuring apparatus. 3. The direct current I'and the inductance L'of the core (1) are substituted by substituting the measured direct current I and the inductance L into an estimation function (12) considering the number of turns of the core (1).
A controller (6) for determining the above is provided. When the obtained DC current I ′ and inductance L ′ are within a predetermined range, it is determined that the number of coil turns is good, and at other times, the number of coil turns is obtained by +1 or −1. When the DC current I ′ and the inductance L ′ are within the predetermined range, it is determined that the number of coil turns is good. In other cases, it is repeated when the predetermined number of times has not been exceeded, while when it exceeds the predetermined number of times, it is determined that the coil is defective. The magnetic characteristic measuring apparatus according to claim 2, wherein 4. The input shape and material of the core (1) as an estimation function (12) considering the number of turns of the core (1),
The magnetic characteristic measuring apparatus according to claim 3, wherein the corresponding estimation function (12) is selected from the function database (10) based on the number of turns.