JPH05113378A - Device for measuring contact state of gland packing - Google Patents

Abstract

PURPOSE:To enhance the reliability in the measurement of the contact stress of a gland packing by displaying a multiple reflected echo at the almost central part of the waveform display region of a display device. CONSTITUTION:A flaw detector part 1 transmits a pulse signal, to a probe 16 from a transmission terminal 11 and the echo receiving signal from the probe 16 is received by a receiving terminal 16 to be outputted to an A/D converter circuit 2. The circuit 2 successively transmits the echo receiving signal to the multiple reflected echo Bi from the contact surface 19 of a gland packing 17 and the inner peripheral surface of an object 18 to be inspected obtained from the flaw detector part 1 to a waveform data memory 3. The memory 3 issues a sampling completion signal to a microprocessor MPU 5 when the number of data sampled by the circuit 2 is stored up to a predetermined final address. The MPU 5 receives the completion signal from the memory 3 to stop the sampling processing of the circuit 2 and collects measured data from the memory 3 to form the display data of an A scope image and the A scope image is displayed on a CRT 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gland packing contact state measuring device, and more specifically, it measures the level of multiple reflection echoes of ultrasonic waves to measure the reflectivity at the contact surface of the gland packing. To an ultrasonic measuring device for measuring the tightened state of the gland packing.

[0002]

2. Description of the Related Art The applicant of the present application is Japanese Patent Application No. Hei 2-320686 which measures the tightening state of the gland packing by measuring the level of multiple reflection echoes of ultrasonic waves on the contact surface of the gland packing. In the patent application. The model is the same as a valve or cylinder that uses a gland packing, and the contact pressure is measured with a strain gage using this model, and the reflectance of ultrasonic waves at the contact surface of the gland packing for each contact pressure is specified. It is obtained by measuring the level of multiple reflection echo after multiple reflections. Then, at this time, using the measured data of the relationship between the level of the multiple reflection echoes at the contact surface of the gland packing and the contact pressure obtained by this model at this time, the valve or cylinder of the actually used valve or cylinder corresponding to this model is used. The contact pressure of the gland packing in an actually used valve or cylinder is obtained by measuring the current level of multiple reflection echoes for the gland packing.

In the measurement, the length of the measurement time axis given as an initial condition is set to a time slightly longer than the propagation time to the target multiple reflection echo. Then, the maximum echo height (peak value) and beam path length (time value up to that point) of the target multiple reflection echo are multiplied by the position of the target multiple reflection echo through the gate, and the received voltage value and the time count value of the path length counter Then, the measurement data such as the contact pressure is calculated by capturing the data with a microprocessor (MPU) or the like and processing the data.

[0004]

The position of the gate to be set in this measurement is selected from multiple reflected echoes displayed on the display. Figure 4
Shows a display state of the multiple reflection echoes B _{1 to} B ₉ when the gate 21 is set for measurement. In addition,
In the figure, 22 is a multiple reflection echo (B ₉ ) corresponding to the desired number of reflections, and 23 is a part of the waveform of the transmission wave T. When measuring the tightening state of the gland packing in this way, in order to handle the multiple reflection echoes after being reflected a certain number of times, as shown in the figure, many multiple reflection echoes B _{1 to} B ₉ are displayed on the screen 20 of the display. Is very difficult to see. Therefore, there is a high risk of misreading the multiple reflection echo B ₉ after the target number of multiple reflections, and there is a drawback that the measurement condition and the echo actually extracted by the gate are different and the reliability of the measurement is lowered. An object of the present invention is to solve such a problem, and it is possible to accurately capture an echo after a desired number of multiple reflections, and to improve reliability of contact stress measurement of a gland packing. An object of the present invention is to provide a contact state measuring device for a gland packing that can be performed.

The contact state measuring device of the gland packing of the present invention for attaining the above object is characterized in that it is reflected a predetermined number of times based on the sound velocity of the object, the wall thickness, and the predetermined number of multiple reflections to be measured. The propagation time until the occurrence of the subsequent multiple reflection echo is calculated, and the multiple reflection echo after a predetermined number of reflections is displayed according to this propagation time and is displayed in the substantially central portion of the waveform display area on the screen of the display device.

[0006]

As described above, by displaying only the target multiple reflected waves in the substantially central portion of the waveform display area of the display device, the multiple reflected echoes to be gated are not mistaken. In addition, the target multiple reflection echo can be easily extracted by directly A / D converting the echo reception signal and processing the data, so the gate setting work in manual processing becomes unnecessary, and in a more reliable state. It enables measurement of multiple reflected wave echoes.

[0007]

1 is a block diagram of a contact state measuring device for a gland packing according to the present invention, FIG. 2 is an explanatory diagram of a display state of the Nth multiple reflection wave, and FIG. 3 is its reflectance and the like. 3 is a flowchart of the overall processing of the measurement state of FIG.
In FIG. 1, 10 is a gland packing contact state measuring device, and 1 is a flaw detector part thereof. The flaw detector 1 is composed of a pulser / receiver, etc., and sends a pulse signal from the transmission terminal 11 to the probe 16 according to a control signal from the microprocessor (MPU) 5 and an echo reception signal from the probe 16 to the reception terminal 12 The received signal is amplified by the receiver and output to the A / D conversion circuit 2 as an analog signal. As will be described later, the gain (amplification factor) of the receiver can be increased or decreased by a control signal from the MPU 5.

The A / D conversion circuit 2 is provided with a contact surface 19 between the gland packing 17 obtained from the flaw detector 1 in response to a control signal from the MPU 5 and the inner peripheral surface of a cylindrical object 18 such as a valve or a cylinder. Multiple reflection echo Bi of the object 18
(Corresponding to the bottom surface echo of), an echo reception signal (RF signal or a video signal obtained by detecting this) is, for example,
Sampling is performed at a high frequency of about 20 MHz, and the digital values are sequentially sent to the waveform data memory 3.

The waveform data memory 3 has a storage capacity for storing a predetermined number of measured data which is n times (n is an integer of 2 or more) the measured data displayed on the display screen, for example, about 4000 points. However, the digital value data sampled by the A / D conversion circuit 2 is stored while sequentially updating (incrementing) its address. Then, when the number of data sampled by the A / D conversion circuit 2 is stored up to a predetermined final address, a sampling end signal is sent to the MPU 5. As a result, the measured data of a predetermined sampling number that is twice or more the number of measured data displayed as an image in the waveform data memory 3 (for example, if the number of measured data is 200 points, the above 4000 points is 20 times), the measured data is digital The value is sequentially stored for each address. At this time, the measurement data of each address is A /
It is stored as a function of time in units of the sampling cycle of the D conversion circuit 2.

Upon receiving the sampling end signal from the waveform data memory 3, the MPU 5 stops the sampling process of the A / D conversion circuit 2, collects the measurement data from the waveform data memory 3 via the bus 13, and outputs the A scope image data. Generate display data. The generated display data is stored in an image memory area of the RAM 6 (an image memory unit 61 described later), which is transferred to the display device (CRT) 8 and is then displayed by the display device 8 on the A-scope image corresponding to the generated display data. Is displayed.

Reference numeral 4 denotes an operation panel having a gain dial, a cursor dial, a display position designating knob, a sheet key, etc., which is connected to the bus 13. MPU5
Receives a set value set by a dial and various key input signals from this circuit via the bus 13. When the gain setting value (adjustment value) for the flaw detector unit 1 is input by the gain dial, the MPU 5 controls the gain of the receiver (the high frequency amplifier) of the flaw detector unit 1 and the gain setting value input by the gain dial. Set the gain of the receiver so that the gain corresponds to.

Reference numeral 6 denotes a RAM, which is connected to the bus 13 and is designated by digital display data of the echo reception signal which is A / D converted, various application processing programs loaded from the outside, and an input key. Various information such as a flag indicating the flaw detection mode and various data are stored. The RAM 6 includes an image memory section 61 for bit-expanding and storing image display data and a waveform data memory 3.
A sampling condition parameter storage area 62 and a measurement data storage area 63 for determining the conditions for collecting data from are provided.

Reference numeral 7 denotes a ROM, in which, in addition to the A-scope image calculation processing program 71 executed by the MPU 5, a multiple reflection wave processing program 72, a normalized gain setting program 73, a reflectance calculation program 74, a tolerance determination program. 75, and various basic programs are stored. The display device 8 has a video memory interface and a video memory for displaying various measured values in addition to the A-scope image and the like, and a video memory controller for reading out information from the video memory and generating a video signal. , Is connected to the bus 13 via the video memory interface.

Here, the A-scope image calculation processing program 71 is usually started by the MPU 5 which has received the measurement data collection end from the waveform data memory 3, and the waveform data memory according to the conditions stored in the data collection condition storage area 62. The display data is generated by accessing the address No. 3 and stored in the image memory unit 61. As a result, predetermined measurement data is displayed on the screen of the display device 8.

In addition, a storage area 62 for collecting sampling condition parameters and the like.
The information stored in is the sound velocity inside the object 18 such as a valve or cylinder input from the operation panel 4 as an initial measurement condition, the wall thickness of the object 18, the number of reflections of multiple reflection waves to be used, and others. These are parameters that determine the measurement conditions necessary for measurement. Further, here, there is a condition of how to collect the measurement data of the waveform data memory 3 from the start address and the end address for reading the measurement data of the waveform data memory 3 and the measurement data of the waveform data memory 3 stored at the addresses between these. For example, parameter information such as whether to collect every few addresses, how many average values are collected from the collected data to be used as display data, or the highest value of multiple measurement data to be used as display data is stored. Has been done.

The multiple reflection wave processing program 72 is started when the function key for multiple reflection echo measurement is input and executed by the MPU 5, and the number of reflections of multiple reflection waves input from the operation panel 4, sound velocity, and wall thickness. And are obtained by referring to the storage area 62 such as the sampling condition parameters, and first, the propagation time t to the target multiple reflection echo is calculated. The propagation time t to the target multiple reflection echo is calculated by t = 2NT / V, where N is the number of input reflections, V is the sound velocity, and T is the wall thickness. The multiple reflected wave processing program 72 calculates the read start time ts by ts = T (2N-1) / V in order to obtain the address of the read start point in the waveform data memory 3 for the target multiple reflected echo. Then, the address of the time position corresponding to this is obtained as the starting point address As. Further, the time point te of the end point of the display data is calculated by te = T (2N + 1) / V, and the address of the time position corresponding to this is obtained as the end point address Ae. Then, the values of the start point and end point addresses As and Ae obtained here are stored in the sampling condition parameter storage area 62. The calculation of the start point and end point addresses As and Ae results in time-axis calibration of the measurement data display of the multiple reflection echoes displayed by the A-scope image calculation processing program 71. Thereafter, the multiple reflected wave processing program 72 starts ultrasonic measurement processing on the object 18 such as the valve or cylinder packed by the gland packing 17 according to the parameters stored in the storage area 62 such as the sampling condition parameters. , The measurement data is stored in the waveform data memory 3. Then, the A-scope image calculation processing program 71 is started next.

A scope image calculation processing program 71
Is a sampling condition parameter based on the total number of display pixels on the side (time axis) that displays the path length of the A scope image on the display screen of the display device 8 for the measurement data stored in the waveform data memory 3 by the MPU 5. Equivalent storage area 6
First, the number of measurement data to be collected is determined according to the parameters stored in 2. For example, if the number of pixels in the lateral direction measured data display pixel number of the display device 8 that is the display corresponding to the road length is 200 pixels assigned as the road length display, it is collected as display data from the waveform data memory 3. The measured data is 200 pieces. Note that 2 pixels are 1
If allotted to the measurement data, half that number, 100, will suffice. Therefore, here, the number of data collected from the waveform data memory 3 will be 200, and will be described below.

A scope image calculation processing program 71
Is calculated by generating a parameter indicating what kind of measurement data 200 pieces are to be collected from the waveform data memory 3. That is, the A-scope image calculation processing program 71
The 200 pieces of data collected by are collected when the start and end addresses As and Ae are present, and when they are not stored, the data of the display start position and the display end position input from the operation panel 4 and the data are collected. It is determined by the processing of the A-scope image calculation processing program 71 based on the conditions. This is because, first, when there are addresses As and Ae at the start point and the end point, based on this, based on the addresses of the waveform data memory 3 corresponding to the display start position and the display end position, respectively, between them. When a certain number of measurement data is calculated and is 200 or more, depending on the numerical value m determined by m = M / 200 with respect to the number M, for example, when m = 3 or 2.5 ≦ m When <3.5, generate a parameter that collects data every 3rd item. Such parameters are stored in the storage area 62 such as the sampling condition parameter corresponding to the addresses As and Ae of the start and end points. If not, the data is stored in the storage area 62 such as the sampling condition parameter together with the addresses of the display start position and the display end position that have been calculated previously. Further, when the average value is designated as the collection condition, the measurement data for every three pieces is treated as a group, and the parameters for calculating the average value are set. Further, when collecting the maximum value, a parameter for selecting the maximum value of the group is set. On the other hand, when the total number of measurement data including the display start position and the display end position is 200 or less, a parameter for generating data interpolated to 200 is generated and stored in the storage area 62 such as the sampling condition parameter. To do.

As a result, when the function key for multiple reflection echo measurement is input, the A scope image arithmetic processing program 71 causes the start point and end point addresses As and Ae.
The multi-reflection echo image specified as the measurement image according to is such that the data from the display start position to the display end position of the display image fills the screen (if there is a waveform display area, the area is full), and the echo position is in the center. The display data of 200 points is generated. 200 pieces of data for that purpose are sampled from the waveform data memory 3 in accordance with the number of pixels on the path side of the display screen according to the parameters, and the image memory unit 61 is obtained.
Process to transfer to. The image displayed at this time becomes an image as shown in FIG. 2A, and an echo as shown by Bn is obtained as a multiple reflection echo of the contact surface 19.
In addition, 8a is a screen of the display device 8, the horizontal X-axis is the time axis, and the vertical Y-axis is the echo level (%).

By performing such a display, only the target multiple reflection echo Bn is displayed on the screen, and therefore the target for setting the gate or the like is not mistaken. In addition,
In this embodiment, as can be understood from the processing described later,
Since the echo reception signal is A / D converted as it is for data processing, the echo level of the multiple reflection echo Bn and the measured value of the path length can be easily obtained without setting a gate.

The normalized gain setting program 73 automatically sets the measurement gain for normalizing the value of the multiple reflection echo Bn in order to obtain the reflectance without performing the gate setting operation for the multiple reflection echo Bn. It is a processing program. In this program, 200 pieces of data are collected from the waveform data memory 3 and transferred to the image memory unit 61,
It is activated by the A-scope image calculation processing program 71 after the previous multiple reflection echo Bn is displayed. When this is started and executed by the MPU 5, the measurement for the subject 18 is repeated so that the level of the multiple reflection echo Bn becomes a predetermined reference value, and the measurement is automatically performed as indicated by the dotted line in FIG. 2 (a). The gain of the receiver of the flaw detector 1 is set to.

This is to automatically adjust the gain of the receiver of the flaw detector 1 so that the multiple reflection echo Bn obtained as the measurement value in the first measurement becomes a predetermined constant value (for example, level 100%). The gain is adjusted in accordance with the reference level value (here, it corresponds to the level of 100% on the screen of the display device 8) recorded in the storage area 63 of the measurement data and the like (sequentially to the receiver by the control of the MPU 5). The gain is adjusted by increasing / decreasing the control value) and the echo level of the multiple reflection echo Bn is set to 100%.
Set the gain to the level of and set it as the gain of the receiver at the time of measurement. It should be noted that this may be adjusted by gain setting by the operation of the operator.

As a result, as shown in FIG. 2A, the level of the multiple reflection echo Bn is increased or decreased according to the execution of the normalized gain setting program 73 or the operator's gain control operation to reach 100%. The gain of the receiver of the flaw detector 1 is set to such a value. After this, this program activates the reflectance calculation program 74. Note that, once the gain of the receiver is set once, the normalized gain setting program 73 is not started until the function key for multiple reflection echo measurement is input next time. Therefore, the gain set here is not changed until the measurement is completed.

The reflectance calculation program 74 is used for the first measurement.
The second time is started by the normalized gain setting program 73, and the second and subsequent measurements are started by the A-scope image calculation processing program 71 after the previous multiple reflection echo Bn is displayed. When this program is executed by the MPU 5, the MPU 5 calculates the echo level and the propagation time (path length) of the multiple reflection echo Bn obtained by the measurement by referring to the data in the waveform data memory 3, and measures them. The reflectance is calculated by storing the value in the equal storage area 63 and further taking the ratio of the normalized value to a calculation reference value provided in advance. This reflectance is obtained by taking the difference between the adjacent echoes of the multiple reflection echoes B ₁ to Bn (see FIGS. 4B _{1 to} B ₉ ) which are normalized and measured, and further taking the average value of them. May be stored in the storage area 63 such as the measurement data as the reflectance. After this,
The tolerance determination program 75 is started by this program.

The tolerance judgment program 75 is executed by the MPU 5, and the MPU 5 thereby obtains the multiple reflection echo Bn obtained by the current measurement stored in the measurement data storage area 63 by the processing of the reflectance calculation program 74. It is determined whether or not there is a difference of a certain value or more with respect to the peak value and the road distance stored as a reference for any of the peak value and the road distance of, and when there is a difference of a certain value or more, as an error,
This error is recorded as a flag corresponding to the data stored in the storage area 63 such as the measurement data, and the alarm device is driven.

Next, the overall operation will be described with reference to FIG. 3. First, in step 101, initial processing for initial setting for setting the apparatus in the flaw detection mode is performed. In step 102, the sound velocity V at the subject 18, the wall thickness T, the number of multiple reflections N, the reference value of the tolerance,
The measurement interval, measurement time, number of measurements, etc. are input from the operation panel 4.

In the next step 103, a key input waiting loop is entered, and when the function key for multiple reflection echo measurement is entered from the operation panel 4, the multiple reflection echo measurement mode is set in step 104, The multiple reflected wave processing program 72 is executed by the MPU 5 to calibrate the time axis of the measurement data display. As a result, the time axis of the multiple reflection echo displayed on the display device 8 is T (2N−V) with T2N / V as the center, as shown in FIG.
1) / V to T (2N-1) / V. As a result, only the Nth multiple reflection echo Bn is displayed as shown in the figure. In the next steps 105 and 106,
The normalized gain setting program 73 is started, the measurement is repeated, the automatic gain adjustment is performed, the gain of the receiver of the flaw detector 1 is set, and the level of the multiple reflection echo Bn becomes 100%. ) Is normalized.

In the next step 107, the reflectance calculation program 74 is started, and the echo height, the beam path and the reflectance of the multiple reflection echo Bn at that time are stored in the measurement data storage area 63 of the memory 6. And step 1
At 08, the tolerance judgment program 75 is started to judge whether both the echo level of the multiple reflection echo Bn and the path length are within the tolerance range, and if within the range,
The determination as to whether or not the measurement is completed in step 109 is made by comparing with the input number of measurements M. If the measurement is not completed, the number of measurements M is updated in step 110 and the process moves to the next measurement process. Returning to step 107, the measurement result is output in step 111 after the measurement of the number of times M has been completed. On the other hand, if the result of determination in step 108 is not within the tolerance range, the alarm device is driven in step 112 and the process proceeds to step 109. In this case, the measured values that are not within the tolerance range are marked in step 111 according to the flag stored in the measured data storage area 63, and the data is output.

As described above, in the embodiment, the echo Bn of the multiple reflection wave is displayed in the center of the screen of the display device. However, since only one echo is displayed, it is displayed almost in the center. The position to be displayed may be substantially the center of the waveform display area when it is allocated on the screen. In the embodiment, the echo reception signal is A / D converted and each measured value is obtained according to the data stored in the waveform data memory. The peak detection circuit and the counter measure the peak value and the path length of the echo reception signal. May be detected by and after this, each data is A / D converted and M
It may be processed by the PU and stored in the memory, and the measured values such as the peak value and the path length of the multiple reflection echo may be obtained based on these data.

In the embodiment, the waveform data memory is an A / D
Although it is inserted between the conversion circuit and the MPU, if the processing speed of the MPU is high, the data of the A / D conversion circuit will be MP
It is also possible for U to receive the data once, transfer it to the waveform data memory, and collect the measurement data. Further, in the embodiment, one pixel on the side corresponding to the road length is displayed corresponding to the time corresponding to one measurement data, but it goes without saying that n pixels may be displayed corresponding to one measurement data. is there.

[0031]

As can be understood from the above description, in the present invention, since only the intended multiple reflection echo is displayed in the substantially central portion of the waveform display area of the display device, the gate setting is performed. Do not mistake the target multiple reflected waves. In addition, the target multiple reflection echo can be easily extracted by directly A / D converting the echo reception signal and processing the data, so the gate setting work in manual processing becomes unnecessary, and in a more reliable state. It enables measurement of multiple reflected wave echoes.

[Brief description of drawings]

FIG. 1 is a block diagram of a gland packing contact state measuring device of the present invention.

FIG. 2 is an explanatory diagram of a display state of the Nth multiple reflection wave.

FIG. 3 is a flowchart of the overall processing of the measurement state of the reflectance and the like.

FIG. 4 is an explanatory diagram showing a display state of multiple reflection echoes when a gate is set for measurement in the prior art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic flaw detector part, 2 ... A / D conversion circuit, 3 ... Waveform data memory, 4 ... Operation panel, 5 ... Microprocessor (MPU), 6 ... RAM, 10 ... Gland packing contact state measuring device, 61 ... Image memory unit, 62 ... Storing condition parameter storage area, 63 ... Measurement data storage area, 7
1 ... A scope image calculation processing program, 72 ... Multiple reflection wave display processing program, 73 ... Normalized gain setting program, 74 ... Reflectance calculation program, 75 ... Tolerance determination program.

Front page continuation (72) Inventor Shin-ichi Hara, Osaka Prefecture Osaka City, Kita-ku, 3-3-22 Nakanoshima Kansai Electric Power Co., Inc. (72) Inventor Isao Yamamoto 2-1-1 Kitamura, Taisho-ku, Osaka City, Osaka Prefecture Utsue Valve Co., Ltd. (72) Inventor Hiroo Ueda 2-1-1 Kitamura, Taisho-ku, Osaka-shi, Osaka Utsue Valve Co., Ltd. (72) Inventor Takuya Miyaguchi 2-1-1 Kitamura, Taisho-ku, Osaka-shi, Osaka Utsue Valve Co., Ltd. In-house (72) Inventor Takeshi Miyajima 650 Jinrachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd.Tsuchiura factory (72) Inventor Yoshimi Shiba, 650 Jin-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. (72) Inventor Toshio Takishita, 650 Kintate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd.

Claims (1)

[Claims] 1. A gland packing is obtained by obtaining a peak value and a path length of a multi-reflection echo after a predetermined number of reflections of ultrasonic waves reflected from a contact surface with the gland packing for an object having a gland packing. In the ultrasonic measuring device for measuring the contact state of the
Based on the predetermined number of times, calculate the propagation time until the occurrence of multiple reflection echoes after the predetermined number of reflections, and according to this propagation time the multiple reflection echoes after the predetermined number of reflections of the waveform display area on the screen of the display device. A device for measuring the contact state of a gland packing, which is displayed in almost the center.