JPH07120333A - Method for measuring tension by attenuating vibrating - Google Patents

Abstract

PURPOSE:To measure a tension highly accurately without generating measuring errors, by vibrating a object to be measured by applying an external force, detecting a change of shifting amount of the object during a resonance/attenuating vibration after the external force is stopped, and obtained a resonant frequency. CONSTITUTION:When a grid element 7a is vibrated from the outside and then the vibration is stopped, a resonance/attenuating motion of the grid element 7a is detected by a displacement sensor 53. More specifically, an analog output voltage waveform is input to an HPF 61 to cut direct current components and low frequency components. Thereafter, the waveform is amplified at an amplifier 62 and further high frequency components are cut at an LPF 63. The processed waveform is input to a waveform- converting part 64, where a sine wave is converted to a rectangular wave. Then, the rectangular wave is input to a cycle-measuring part 65 and a cycle (T) of the rectangular wave is measured. A value of the cycle is taken into a control part 66 and converted into a frequency (f) according to f=1/T/. A memory 67 stores distance data and data of measuring positions in the right and left directions of the grid element 7a which are different depending on the kind of pipes. The data are supplied to the control part 66 correspondingly to the kind of pipes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the tension of a grid element which constitutes a color selection electrode of a cathode ray tube, and more specifically, by detecting a change in the displacement amount of an object to be measured in a damping vibration process. , The grid element is measured.

[0002]

2. Description of the Related Art In the process of assembling a color selection electrode for a cathode ray tube, the tension of a grid element constituting a grid structure is measured for quality control of the color selection electrode. As an example of the tension measuring method of this type for performing the measurement while continuously vibrating the grid element, for example, the one described in Japanese Patent Laid-Open No. 4-136729 will be described with reference to FIG. FIG. 8 is a principle view showing a conventional tension measuring method. As shown in the figure,
In the conventional method, air is continuously blown from the air nozzle 1 to the grit element body 2 which is the object to be measured, and the grit element body 2 is caused to resonate while being continuously vibrated. It was measured by the minute distance measuring means 3, the peak part of the wave was counted for 1 second by the counter, and the number of peak parts was read to be the frequency. Then, this operation is continuously repeated a plurality of times (for example, three times), and if each data is almost the same, the average value of these data is used as the resonance frequency, and this is determined as the tension of the grit element body 2. It was.

[0003]

However, in the conventional tension measuring method, in order to measure the resonance frequency of the grit element body 2, it is necessary to continuously repeat counting a plurality of times. The grit element body 2 had to continue to resonate. And, to vibrate the grit element body 2 for several seconds while continuously vibrating from the outside,
It was very difficult, and in particular, it was virtually impossible to continue to resonate an extremely fine grid element for a high definition tube with a fine pitch. Further, in the conventional method, since the grid element body is resonated in a state where vibration is continuously applied from the outside, an error may occur in the measured resonance frequency. Further, when air is used for the vibration exciter, in order to obtain stable vibration, fine adjustment of the angle of the air nozzle 1, the air flow rate, etc. is always required, which makes maintenance extremely complicated.
The present invention has been made in view of the above situation, and by making it possible to measure the resonance frequency without continuously resonating the grit element body, it is possible to measure the tension of an extremely thin grid element body, and a measurement error occurs. The purpose of the present invention is to provide a tension measuring method which does not exist, thereby improving the measuring ability and the measuring accuracy.

[0004]

A tension measuring method by damping vibration according to the present invention for achieving the above object vibrates an object to be measured by applying an external force, and resonates after the external force is stopped. It is characterized in that a change in the displacement amount of the object to be measured during the damping vibration process is detected, a resonance frequency is obtained from the change in the displacement amount, and the resonance frequency is obtained as the tension of the object to be measured. Further, the tension measurement method using damped vibration preferably measures the cycle of resonance / damped vibration and obtains the resonance frequency by converting this cycle. Further, these tension measuring methods may detect resonance / damped vibration with a displacement sensor and input an analog output voltage waveform from the displacement sensor to a high-pass filter and a low-pass filter for processing.

[0005]

When the vibration is stopped after the object to be measured is vibrated from the outside, the object to be measured starts resonance / damped vibration with a stable waveform without distortion by the force from the outside. If the change in the displacement of the DUT during the resonance / damping vibration process is detected, it is not necessary to continuously vibrate the DUT in order to measure the change in the displacement of the DUT. Difficult vibration control of the object to be measured becomes unnecessary, and the change in displacement amount can be detected with a stable waveform without distortion. Further, if the cycle of resonance / damped vibration is measured and the resonance frequency is obtained by converting this cycle, it is not necessary to repeat the pulse counting operation for a predetermined time multiple times, and high-speed frequency measurement becomes possible. . Furthermore, if the analog output voltage waveform from the displacement sensor is input to the high-pass filter and the low-pass filter, the DC component, low frequency component, and high frequency component are cut, and the noise caused by the distortion in the vibration direction is removed, and the distortion It will be possible to extract a waveform with no noise.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a tension measurement method by damping vibration according to the present invention will be described in detail below with reference to the drawings.
1 is a block diagram for explaining the measuring method of the present invention, FIG. 2 is a layout of the measuring unit, FIG. 3 is a front view of the measuring unit, FIG. 4 is a plan view in which a part of the measuring unit is omitted, and FIG. 5 is a measuring unit. FIG. As shown in FIG. 2, this tension measuring method measures the tensions of the grid element body 7a at the center and the grid element bodies 7b at both ends of the grid structure 6 stretched on the frame 5 of the color selection electrode. The measurement units 8 and 9 are arranged at the respective measurement points. That is, the first measuring unit 8 for measuring the tension of the grit element body 7a at the central portion is arranged on the back surface side of the grit element body 7a, and the second measuring unit for measuring the tension of the grid element body 7b at both end portions. 9 is arranged on the front surface side of the grid element body 7b. The second measuring unit 9 has substantially the same configuration as the first measuring unit 8 and is attached to an arm provided along the curved tangential direction of the grid element body 7b, and a tension measuring means described later. The only difference is that the position of is upside down. Therefore, the description of the configuration will be omitted with the description of the first measurement unit 8 described below.

As shown in FIG. 3, the first measuring unit 8
Is a first slide device 11 and a second slide device 12
The first slide device 11 is slidably attached to the two rails 15a and 15b attached to the side plate 14 installed in the vertical direction with respect to the base 13 by screwing or the like. The slide plate 16 and the first slide plate 18 rotatably attached to the slide plate 16 via a link mechanism 17.
6 is moved in the x direction by a male screw 20 (longitudinal in the x direction) attached to a deceleration rotation mechanism 19 driven by a belt and a feed screw mechanism 22 by a nut 21 attached to the slide plate 16 by screwing or the like. It is designed to slide.

The deceleration rotation mechanism 19 is, as shown in FIG.
The drive pulley includes a drive motor 23, a drive pulley 24 attached to the tip of the shaft of the drive motor 23, and a drive pulley 25 attached to the tip of the male screw 20.
The male screw 20 is rotated by applying the rotational movement of No. 4 to the driven pulley 25 via the belt (shown by the chain double-dashed line) 26. The rotation of the male screw 20 moves the nut 21 in the axial direction of the male screw 20, and slides the slide plate 16 in the x direction. The link mechanism 17 includes the slide plate 1
6, a nut 28 rotatably attached by a shaft 27 and a nut 30 rotatably attached by a shaft 29 to the first sliding plate 18 are bite-in joint 31.
It is configured by connecting. Therefore, the first sliding plate 18
Are rotatable with respect to the shaft 27 and the shaft 29, respectively.

The first sliding plate 18 has two curved rails 3 attached to the side plate 14 by screwing or the like.
It is also slidable with respect to 2a and 32b. That is,
Curved surface 33 provided on the upper part of the first curved rail 32a
a and the V grooves of the two rotary plates 34 attached to the first sliding plate 18 are brought into contact with each other, and the curved surface 33b provided under the second curved rail 32b and the first curved surface 33b are similarly provided. By abutting the V groove of one rotary plate 35 attached to the sliding plate 18 (see FIG. 5), the first sliding plate 18 can also slide on these curved rails 32a and 32b. Is configured to be. In particular, the rotating plate 35 is replaced by the spring 36.
Since the two rotating plates 34 press the first curved rail 32a downward and the rotating plate 35 presses the second curved rail 32b upward, the two rotating plates 34 press the first curved rail 32a upward. Becomes The curvature surfaces 33a and 33b of the first and second curved rails 32a and 32b have substantially the same radius of curvature, and the grid structure 6 is used.
The radius of curvature is almost the same. Therefore, the first slide plate 18 is the slide plate 16 of the first slide mechanism 11.
Slides in the x direction, it slides in the x direction while slightly moving up and down along the curvature of the curvature rails 32a and 32b. Note that reference numerals 38 and 39 in the figure denote rolling bearings that also serve as supports for the side plate 14 of the male screw 20.

The second slide mechanism 12 has a rail 41 (see FIG. 5) attached to the first slide plate 18,
It has a second sliding plate 42 that is slidably mounted, and this second sliding plate 42 is attached to the shaft of a drive motor 43 that is mounted on the first sliding plate 18 by screwing or the like. A male screw 45 connected via a shaft coupling 44 and a feed screw mechanism 47 including a nut 46 attached to the second sliding plate 42 by screwing or the like slides in the y direction. Incidentally, reference numeral 48 in the figure denotes a rolling bearing which also functions as a support for the male screw 45 with respect to the first sliding plate 18.

The second sliding plate 42 of the first measuring unit 8
An L-shaped plate 49 is attached to the upper part by screwing,
The L-shaped plate 49 holds the tension measuring means 50. The tension measuring means 50, as shown in FIG.
And an air nozzle 52 and a micro distance measuring device (hereinafter, referred to as “displacement sensor”) 53 by laser irradiation. The displacement sensor 53 includes a transmitter 53a and a receiver 53.
b. The positional relationship among the members 51, 52 and 53 is
From the side plate 18 side, the proximity switch 51, the air nozzle 52,
The displacement sensor 53 is sequentially arranged. The transmitter 53a of the displacement sensor 53 is in a state of protruding to the outermost side. In particular, the receiving portion 53b of the displacement sensor 53 is located above the transmitting portion 53a and has an inclination angle θ (about 30 °) with respect to the x direction.
Are arranged so as to have an inclination of.

Next, a tension measuring procedure by the first measuring unit 8 thus constructed will be described. FIG. 6 is an enlarged view for explaining the operation of the first slide mechanism, and FIG. 7 is a waveform diagram during the damping process of the grid element body. First, the first slide plate 18 is slid in the x direction by the first slide mechanism 11, and the tension measuring means 50 is arranged on the back surface of the central portion of the grid element body 7a. Next, by the second slide mechanism 12,
By sliding the second sliding plate 42 upward, the tension measuring means 5
0 is brought close to the grid element body 7a. At this time, the distance n between the transmitter 53a of the displacement sensor 53 and the grid element body 7a
The proximity switch 51 operates (for example, turns on) when the distance (see FIG. 5) becomes about 40 mm, and the second slide mechanism 12
Stop the operation of.

Next, the first slide mechanism 11 is caused to scan in a fixed direction, and the slits S on both sides of the grid element body 7a.
1, S2 (see FIG. 6) is detected, a drive pulse is supplied to the drive motor 23 from the control unit described later, and the first slide mechanism 11 is moved in the left-right direction (FIG. Middle, arrow x direction). As a result, the spot of the displacement sensor 53 is aligned with the center a of the grid element body 7a. After the displacement sensor 53 is aligned with the center of the grid base body 7a, the grid base body 7a is vibrated from the outside by the air nozzle 52 which is a vibrator. In addition,
In this embodiment, air is used for the vibrator, but the vibration means is not limited to this, and in addition, an impact is applied directly to the frame 5 holding the grid structure 6 by, for example, a hammer or the like. Alternatively, the grit element body 7a may be vibrated.

After the vibration is applied from the outside, the vibration is stopped, and the resonance / damping vibration of the grid element 7a (see FIG. 7) is detected by the displacement sensor 53. That is, as shown in FIG. 1, the analog output voltage waveform is converted into a high-pass filter 6
1 to cut the direct current component and low frequency component, and then amplifies by the amplifier 62, and further the low pass filter 6
At 3, the high frequency components are cut. Then, the waveform subjected to these processes is input to the waveform conversion unit 64, the sine wave is converted to a square wave, and then input to the period measurement unit 65 to measure the period (T) of the square wave. This value is taken into the control unit 66, and the control unit 66 converts it into a frequency from the relational expression of f (frequency) = 1 / T. In the figure, 67 is a memory that stores the distance data and the measurement position data in the left-right direction of the grid element body 7a that differs depending on the tube type, and supplies the data to the control unit 66 corresponding to the tube type. ing. Then, the control unit 66 supplies a drive pulse based on this data to the drive motor 23.

In the frequency measurement of this method, frequency measurement can be performed at extremely high speed as compared with the method of counting the number of pulses per second in the conventional method. For this reason, it is possible to sufficiently measure the resonance frequency even during a short period of time during which the grit element body 7a undergoes damped oscillation, which is not possible with the conventional method. Further, the resonance / damped vibration of the grid element body 7a after the vibration is stopped is obtained as an extremely stable stable waveform without distortion, as compared with the case where the grid element body 7a is continuously excited as in the conventional case. . As a result, a stable waveform without distortion can be frequency-measured at high speed. The 0N / 0FF operation control of the shaker is performed by the control unit 66. In this case, for example, even when air is used for the exciter, it is sufficient to perform the excitation only once, so that it is not necessary to continue to excite the grid element body 7a as in the conventional case, and the flow rate of the air is automatically adjusted. Feedback control for controlling is also unnecessary.

[0016]

As described in detail above, according to the tension measuring method by the damping vibration of the present invention, it becomes unnecessary to control the vibration of the object to be measured, and the change of the displacement amount can be detected. Since it can be performed with a stable waveform with no distortion, it is possible to measure the tension of an extremely thin grid element for a high-definition tube with a fine pitch. Then, since the change in the displacement amount of the object to be measured is detected after the vibration to the grit element body is stopped, an error does not occur in the measurement resonance frequency, and the measurement accuracy can be improved. Further, if the cycle of resonance / damped vibration is measured, it is not necessary to repeat the pulse counting operation for a predetermined time, and high-speed frequency measurement can be performed. Further, since it is not necessary to continuously vibrate the object to be measured, fine adjustment of the vibration exciter is not necessary to obtain stable vibration, and maintenance is improved.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a measuring method of the present invention.

FIG. 2 is a layout view of a measurement unit.

FIG. 3 is a front view of a measurement unit.

FIG. 4 is a plan view in which a part of the measurement unit is omitted.

FIG. 5 is a side view of the measurement unit.

FIG. 6 is an enlarged view for explaining the operation of the first slide mechanism.

FIG. 7 is a waveform diagram in the attenuation process of the grid element body.

FIG. 8 is a principle view showing a conventional tension measuring method.

[Explanation of symbols]

 7a Grid element (measurement object) 53 Displacement sensor 61 High-pass filter 63 Low-pass filter

Claims (3)

[Claims] 1. A change in the amount of displacement of the measured object is detected in the resonance / damping vibration process after the external force is applied to vibrate the object to be measured and the external force is stopped. A resonance frequency is obtained from the resonance frequency, and the resonance frequency is obtained as the tension of the object to be measured. 2. The tension measurement method according to claim 1, wherein the resonance frequency is obtained by measuring a cycle of the resonance / damped vibration and converting the cycle. 3. The resonance / damped vibration is detected by a displacement sensor, and the analog output voltage waveform of the displacement sensor is input to a high-pass filter and a low-pass filter for processing. Method of measuring tension by damping vibration of.