JPH05273282A - Inspection apparatus of variable porcelain capacitor - Google Patents

Abstract

PURPOSE:To guarantee the high quality of a variable porcelain capacitor in a short time by a method wherein one of terminals for the variable porcelain capacitor is connected to the ground side, the other is connected to a measuring terminal and the capacitor is inspected continuously in a turning state. CONSTITUTION:A variable porcelain capacitor 7 is put into a pallet 1; a motor holding part 4 is lowered. A rotor at the capacitor 7 is connected to a driver 2, and a measuring terminal part 8 and a ground connection part 9 are connected to a stator terminal and a rotor terminal. When a coupling operation is finished, a pulse motor 3 is driven, and the rotor at the capacitor 7 is turned via the driver 2. When the rotor is turned, reference signals for measurement are supplied from the terminal part 8 and the connection part 9. A continuous capacity change signal which corresponds to the rotation is amplified by means of an amplification part 10 and output to a capacity measuring part 11. In the measuring part 11, a sinusoidal-wave voltage signal due to a change in the capacity of the capacitor 7 and a stray capacity cancellation signal are analog- operated, and are converted into capacity change signals. In a judgment part 12, the maximum value and the minimum value of the change in the capacity are judged, a capacity change waveform is processed and a deflection part is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention automatically and accurately measures the maximum and minimum values of the capacitance of a variable porcelain capacitor such as a variable porcelain capacitor whose capacitance value can be varied, and adjusts the capacitance to a specified value. The present invention relates to an inspection device for a variable porcelain capacitor, which is capable of judging whether a component such as a defective assembly or a porcelain crack is defective.

[0002]

2. Description of the Related Art A variable porcelain capacitor is required to be compact and highly accurate as electronic circuits are highly integrated, miniaturized, and surface mounted.

A conventional variable porcelain capacitor inspection device will be described below. Capacitance measurement by a conventional variable porcelain capacitor inspection device is mainly based on the automatic balancing bridge method as shown in FIG. 6, and this measurement method is based on a measurement signal source 30, a measurement sample C _x 31, Standard resistance R _s 32, buffer amplifier 33 and voltage-current converter 34
The balance of the current flowing through the measurement sample C _x 31 and the current flowing through the standard resistance R _s 32 is controlled so that the potential at the point G becomes zero, and the measurement sample C _x 31 and the standard resistance R _{s are controlled.}
Two vector voltages E _x and E _s applied to a series circuit of 32 are measured, and a standard resistance R _s 32 of which the value is known beforehand is measured.
This is a method of calculating the capacity of the measurement sample C _x 31 by performing the calculation according to (Equation 1).

[0004]

[Equation 1]

[0005]

However, such a conventional variable porcelain capacitor inspection device can only measure the capacitance value at one point in the unit of capacitance of the variable porcelain capacitor, so that the change in capacitance is continuously measured. However, in the case of measuring a plurality of capacitances simultaneously, it is necessary to separate each capacitance and measure it separately from the others.

Further, in the conventional inspection apparatus, since the capacitance is measured by a bridge, if one terminal of the capacitance is grounded or connected to another capacitance, the measurement cannot be performed or a large measurement error occurs. Was occurring. Further, when a plurality of the same inspection devices are used to measure a plurality of points, mutual interference between the devices occurs and accurate measurement cannot be performed. Furthermore, in order to inspect component parts such as cracks in porcelain and defective assembly, it is necessary to manually check the capacitance change signal, which requires time and labor for product transportation and inspection due to the configuration of the production line. There were many problems.

The present invention solves the above problems and provides a variable porcelain capacitor inspecting device capable of high quality assurance in a short time by inspecting the rotating state of a variable porcelain capacitor at high speed and with high precision. The purpose is that.

[0008]

In order to solve the above problems, the present invention provides a ground connecting portion for connecting either the stator terminal or the rotor terminal of a variable porcelain capacitor to the ground side, and the other terminal. A driver that has a measuring terminal part to be connected and that engages with the rotor-side rotating body of the variable porcelain capacitor to control the rotation of the rotor, and the capacity of the variable porcelain capacitor that changes as the driver rotates the rotor. It has a capacity measuring part for measuring and a judging part for detecting cracks in porcelain, and when measuring multiple capacities, it has one signal source for measurement and a plurality of standard capacitors ( The same number), a standard capacitor and a capacitor to be measured are placed in series, and multiple circuits that perform analog calculation of the voltage generated at both are placed in parallel to eliminate mutual interference between the circuits. It is obtained by a structure capable of measuring the number of volume at the same time.

[0009]

With the above structure, the change of the variable capacitance can be read in real time by directly looking at the output of the analog calculator in the capacitance measuring section, and as a result, the maximum and minimum values of the capacitance can be measured and the target value can be obtained. It becomes possible to automatically adjust. In addition, it is possible to detect the assembled state of the variable capacitor and the crack of the porcelain by arithmetically processing this waveform.

Further, one measuring reference signal generating section is provided, a plurality of measuring circuits are arranged in parallel, and one terminal is connected to the ground to eliminate mutual interference between the circuits and simultaneously measure a plurality of capacitances. By arranging the standard capacitor and the capacitor to be measured in series, the smaller the capacitance of the capacitor to be measured is, the higher the voltage generated across the capacitor is, so that the measurement accuracy of the minute capacitance can be improved. ..

[0011]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a variable porcelain capacitor 7
Is a pallet portion that holds the variable porcelain capacitor 7, and is configured to hold the attitude of the variable porcelain capacitor 7 against the external force from the measurement terminal portion 8, the ground connection portion 9 and the driver 2.

Reference numeral 2 is a driver for engaging the rotor of the variable porcelain capacitor 7 to rotate the rotor, 3 is a pulse motor for driving the driver 2, 4 is for holding the pulse motor 3, and the pulse motor 3 is placed above and below. A motor holding unit that engages and disconnects the rotor of the variable porcelain capacitor 7 and the driver 2 by performing 5 is a pulse motor driver unit that drives the pulse motor 3, and 6 controls the motor driver unit 5. A motor control unit, 8 is a measurement terminal unit that contacts the stator terminal of the variable porcelain capacitor 7, 9 is a ground connection unit that connects the rotor terminal of the variable porcelain capacitor 7 to the ground side, 10 is an amplification unit that amplifies a minute signal, 11 Is a capacitance measuring unit that performs analog calculation of the capacitance value of the variable porcelain capacitor 7 and continuously measures changes in the capacitance value, 1
Reference numeral 2 is a determination unit that determines the maximum value and the minimum value of the capacity and performs arithmetic processing on cracks in the porcelain, 13 is an inspection control unit that controls the motor and the determination unit 12 and manages the entire device, and 14 is a reference for capacity measurement. A reference signal generating unit for measurement that generates a reference signal, and 29 is a floating capacitance canceling unit that erases the floating capacitance generated in the measurement terminal unit 8 and the ground connection unit 9 by analog calculation.

The operation of the variable porcelain capacitor inspection device of the present invention having the above-described structure will be described below.

First, the variable porcelain capacitor 7 to be inspected is put into the pallet 1, the pallet 1 is moved to the positions of the driver 2, the measuring terminal portion 8 and the ground connecting portion 9, and the motor holding portion 4 is lowered to change the pallet 1. The rotor of the porcelain capacitor 7 is brought into contact with the driver 2, and the stator terminal and the rotor terminal are brought into contact with the measuring terminal portion 8 and the ground connecting portion 9.

When the driver 2 is engaged with the variable porcelain capacitor 7, the inspection control section 13 outputs a driver rotation signal to the pulse motor control section 6, and the pulse motor driver 5 is driven to connect the driver 2 to the pulse motor 3. Rotates and the rotor of the variable porcelain capacitor 7 starts rotating.

When the rotor of the variable porcelain capacitor 7 rotates, the measurement reference signal from the measurement reference signal generator 14 is applied from the measurement terminal portion 8 and the ground connection portion 9, and the continuous capacitance change signal corresponding to the rotation is amplified. It is output to the capacitance measuring unit 11 through the unit 10.

In the capacitance measuring unit 11, the sine wave voltage signal accompanying the capacitance change of the variable porcelain capacitor 7 and the floating capacitance canceling signal output from the floating capacitance canceling unit 29 are subjected to analog calculation and converted into a capacitance changing signal.

The determination unit 12 determines the maximum value and the minimum value of the capacitance change, performs the arithmetic processing of the capacitance change waveform, and inspects the defective assembly and the cracks of the porcelain. Further, when it is necessary to adjust the capacitance value, a motor stop signal is output to the inspection control unit 13, and the pulse motor 3 is stopped when the adjustment value is reached. At that time, the measurement terminal portion 8, the ground connection portion 9, and the driver 2 are connected to the variable porcelain capacitor 7
Get away from. After that, the pallet 1 moves and the next product is supplied. By repeating this operation, the variable porcelain capacitor 7 can be continuously inspected.

Next, the measuring circuit system will be described. Figure 2
FIG. 3 is a schematic diagram showing a measurement circuit system of the present device.

Reference numeral 10 denotes an amplifying unit, which is
In the figure, 26 is the inspected capacity C for measurement._xAnd fifteen
Is the inspected capacity C_xStandards for measuring 26
Capacity C _sAnd are arranged so that they are in series.
Reference numeral 16 is a level that facilitates signal processing in the capacitance measuring unit 11.
It is an amplifier to obtain

Reference numeral 11 denotes a capacitance measuring unit, and 14 is a measuring reference signal generating unit for generating a sine wave having a voltage V _s which serves as a reference for inspection.

Reference numeral 17 is a detection section for envelope-detecting the inspection signal and converting it into a direct current, 18 is a subtraction section for subtracting the detected direct current signal with an analog signal, 19 is a division section for performing division with the analog signal, 21 Is an analog-to-digital conversion unit that converts an analog voltage into a digital signal in order to perform arithmetic processing by a microcomputer. Further, 24 is a digital to generate a voltage for erasing the stray capacitance C _o 25 generated in the measuring terminal 8 - an analog conversion unit. Reference numeral 20 is a subtraction unit that performs subtraction to obtain the true value of the measured capacitance C _x 26 including the stray capacitance C _o 25. That is, the stray capacitance canceling unit 29 described in claim 2 has the subtracting unit 20.
And an analog-digital converter 21. The determination unit 12 includes an arithmetic processing unit 22 that arithmetically processes the data sent from the measurement unit 11 and a determination unit (microcomputer) 23.

Regarding the measurement circuit system configured as described above,
The operation will be described with reference to FIG. 3 is the same as FIG. 2 above.
It is a block diagram which shows a specific example. V_sIs the reference signal for measurement
Reference voltage for measurement output from the generator 14, V_xIs
Measuring capacity C_x26 and stray capacitance C_o25 to be measured
Represents a constant voltage. The subtraction unit 18 performs the subtraction shown in (Equation 2) below.
I do. The division unit 19 performs the division shown in (Equation 3) below.
U Output C of division unit 19 _x′ Is the inspected capacity C_x26 and
And stray capacitance C_o25 is the apparent value added
And the true inspected capacitance value C_x26 is obtained by the following (Equation 4)
Be done. The capacity is measured in advance by knowing the capacity.
Standard capacity C_s15 and measured capacitance C_x26 and connect in series
And the voltage generated in each is V_sAnd V_xIs
Then, C is easier than the following (Equation 5)._xThe value of can be calculated.

The advantage of this circuit system is that by connecting C _s 15 and C _x 26 in series, the smaller the value of C _x 26 is, the larger the value of V _x is. It will also be less affected. Further, since the measurement system is an analog circuit, even if the value of C _x 26 changes with time, the value of C _x 26 can be observed according to the change, so that the change in capacitance of the variable porcelain capacitor 7 can be easily measured. it can.

[0026]

[Equation 2]

[0027]

[Equation 3]

[0028]

[Equation 4]

[0029]

[Equation 5]

The operation of the stray capacitance canceling section 29 is as follows.
This is done as follows. Stray capacitance C _oThe value of 25 means
Before the variable porcelain capacitor 7 hits the constant terminal part 8,
Measurement is performed with the output of the digital-to-analog converter 24 set to zero.
You can get it. Therefore, measure this value in advance.
C_oThe voltage corresponding to the value of 22 is digital-analog
By outputting from the conversion unit 24, the true measured volume is always
Quantity C_xA measured voltage output corresponding to a value of 26 is obtained.

The detection of defective assembly of the variable porcelain capacitor 7 and cracks of the porcelain will now be described. The signal obtained from the subtraction unit 20 shown in FIG.
As shown in (A), it is normal to simply increase and decrease sinusoidally. However, if there is an abnormality in the assembly or there is a crack in the porcelain, either
As shown in the figure, the sine wave is distorted, or a phenomenon having an extreme value occurs during the increase and decrease. Therefore, the signal obtained from the subtraction unit 20 is converted into data by the analog-digital conversion unit, and by processing this, it is possible to detect an assembly defect or a crack of the variable porcelain capacitor 7.

Further, in order to adjust the capacitance value of the variable porcelain capacitor 7, the determination unit 12 monitors the capacitance change signal obtained from the subtraction unit 20 in real time to detect the capacitance value to be finally adjusted. A stop signal is output to the inspection control unit 13 to stop the driver 2. In this way, it is also possible to adjust the capacitance value of the variable porcelain capacitor 7.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a diagram of a capacitance and crack measurement system in the case where one side terminals of a plurality of variable porcelain capacitors according to the second embodiment of the present invention are connected. In FIG. 5, reference numeral 10 is an amplifier, 11 is a capacitance measuring unit, 12 is a determining unit, and 14 is a measuring reference signal generating unit. The above is the same as the configuration of FIG. Figure 5
If the amplification unit 10 and the capacitance measurement unit 11 are combined into a capacitance measurement unit 27, a plurality of capacitance measurement units 27 are prepared.
This shows that a plurality of measured capacitances C _xn can be measured at the same time. The output power supply capacity of the measurement reference signal generator 14 is required to have a capacity capable of sufficiently driving a plurality of measured capacitors C _xn . Further, as shown in FIG. 5, each measured capacitance C _xn may be grounded.

[0034]

As described above, the present invention is provided with a measuring terminal that is connected to an electric terminal of a variable porcelain capacitor and that engages with a rotor-side rotor of the variable porcelain capacitor to rotate the rotor. It has a capacity measuring unit that measures the capacitance value of the variable porcelain capacitor that changes with the rotation of the rotor, and a determination unit that detects cracks in the porcelain.
By providing a measurement reference signal generator, a pulse motor for driving the driver, a pulse motor driver, and a motor controller, the maximum and minimum capacitance values can be accurately measured when the rotor of the variable porcelain capacitor is rotated. At the same time, it is possible to inspect for defective assembly and cracks in porcelain, adjust the capacitance value, and the present invention can also be applied to a variable porcelain capacitor in which a plurality of measuring systems are connected and a plurality of terminals on one side are connected. , Can greatly contribute to the improvement of the productivity of variable porcelain capacitors.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an overall configuration in a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a measurement circuit system in the same embodiment.

FIG. 3 is a block diagram for explaining the operation of the measuring circuit system in the embodiment.

FIG. 4A is a normal output waveform diagram when an assembly defect of a variable porcelain capacitor and a crack of a porcelain are inspected in the same embodiment. FIG. 4B is an output waveform diagram showing the same abnormality. Output waveform diagram

FIG. 5 is a schematic diagram showing a measuring circuit system according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating a conventional capacitance measuring method.

[Explanation of symbols]

 1 Pallet 2 Driver 3 Pulse Motor 4 Motor Holding Section 5 Pulse Motor Driver 6 Motor Control Section 7 Variable Ceramic Capacitor 8 Measuring Terminal Section 9 Earth Connection Section 10 Amplifying Section 11 Capacity Measuring Section 12 Judgment Section 13 Inspection Control Section 14 Measurement Reference Signal Generator 29 Stray capacitance canceler

Claims (2)

[Claims] Claim: What is claimed is: 1. A variable porcelain capacitor is provided with a ground terminal for connecting one of a stator terminal and a rotor terminal to a ground side and a measuring terminal section for connecting the other terminal, and the rotor side of the variable porcelain capacitor. Of the variable porcelain capacitor that changes with the rotation of the rotor by this driver, and the capacity measured by this capacity measuring section. A device for inspecting a variable porcelain capacitor, which comprises a determination unit that compares the change with a basic characteristic to detect a characteristic change due to a crack in a porcelain and an assembly defect to detect the presence or absence of a crack in the porcelain and an assembly defect. 2. The variable porcelain capacitor inspection device according to claim 1, further comprising a stray capacitance canceling unit for canceling a stray capacitance of a connecting portion with the variable porcelain capacitor to be measured as the capacitance measuring unit.