JPH0224444B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a running thickness gauge suitable for use in a running thickness gauge that is installed in a cold rolling mill, a continuous inspection machine, etc. and continuously measures the thickness of a plate during running. Regarding.

A roller-type running thickness gauge, which is one of the devices that can continuously measure the thickness of a plate rolled by a cold rolling mill, etc., uses two gauge rollers arranged one above the other as shown in Figure 1. The thickness of the plate 3 inserted between the gauge rollers 1 and 2 is measured based on the axis spacing x between the gauge rollers 1 and 2. The device is configured to control the rolling mill 5 and the like provided upstream of the device, and to display the measurement results on a meter and a recording paper (both not shown).

By the way, in such a roller type running thickness gauge 4, the gauge rollers (measuring stylus) 1 and 2 are eccentric with respect to the corresponding shafts 6 and 7, respectively, and the rotation angle of each of these gauge rollers 1 and 2 changes. When doing so, the interval x changes and accurate measurement becomes impossible.
In addition, an offset occurs between the gauge rollers 1 and 2 and a sensor (for example, a differential transformer) that converts the mechanical measurement results detected by the gauge rollers 1 and 2 into an electrical signal. Errors may occur and the measurement accuracy may deteriorate.

In view of the above circumstances, this invention eliminates the steady offset that occurs during measurement, reduces errors caused by eccentricity of a measuring element such as a gauge roller, and improves measurement accuracy. The purpose is to provide a thickness gauge.

In order to achieve this object, the running thickness meter of the present invention uses a differential transformer 12 to obtain the axial distance between the two gauge rollers 10 and 11 rotating in contact with the plate member 3 as a measurement signal S. The running thickness meter measures the thickness of the plate-shaped member, and in the correction amount calculation mode, the two gauge rollers are brought into contact with each other, and the motor 21 is energized to rotate the gauge roller at least once. At the same time, a control circuit 18 that controls the correction amount calculation circuit 14 and the switch 16 obtains a reference shaft spacing amount based on the output signal of the differential transformer in the correction amount calculation mode under the control of the control circuit, and Obtain the maximum increase and maximum decrease with respect to the reference axis spacing amount while the rollers are rotating, obtain the average change amount by arithmetic averaging, and then add the average change amount and the reference spacing amount to calculate the correction amount. A correction amount calculation circuit 14 calculates and outputs it to the differential amplifier 15, and a switch is switched under the control of the control circuit 18 to change the output of the differential transformer 12 to the measured value S based on the difference between the outputs of the correction amount calculation circuit 14. It is characterized by comprising a differential amplifier 15 that obtains a correction output.

The present invention will be described below with reference to an embodiment shown in the drawings.

FIG. 2 is a block diagram showing an embodiment of the running thickness meter according to the present invention. In this figure, 1
0 and 11 are gauge rollers, and the size of the axial spacing between these gauge rollers 10 and 11 is converted into a corresponding AC signal by a differential transformer 12, and is converted into a corresponding AC signal by an AC signal/DC signal conversion circuit 13 (hereinafter referred to as AC/DC signal converter circuit 13). (abbreviated as direct conversion circuit 13). The AC/DC conversion circuit 13 is composed of a synchronous detector and the like, and detects the output from the differential transformer 12, converts it into a DC signal, and supplies it to the correction amount calculation circuit 14 and the differential amplifier 15. Correction amount calculation circuit 14
is a peak hold circuit, analog adder, A/D
It is composed of a converter (analog/digital converter), a digital arithmetic circuit, a D/A converter (digital/analog converter), etc., and when the correction amount calculation mode is set, the AC/DC converter circuit 13 offset component in this output from the output of the gauge roller 10,
A correction voltage V _F that reduces the error component caused by the eccentricity of switch 11 is determined and applied to terminal 16 of switch 16.
a, the differential amplifier 15 via the common terminal 16c;
and when the measurement mode is set after this, the correction voltage V _F obtained in the correction amount calculation mode
Hold and output. The differential amplifier 15 detects and amplifies the difference between the output of the AC/DC conversion circuit 13 and the output (or ground voltage) of the correction amount calculation circuit 14.
The output is supplied to a meter 17 for display, and is also supplied to a control circuit 18. Control circuit 18
is composed of a microprocessor, RAM (random access memory), ROM (read-on memory), various interfaces, etc. When the correction amount calculation mode is set using the operation panel 19, Supplying a motor drive signal to the motor control circuit 20 to energize the motor 21 to rotate the gauge rollers 10 and 11,
A correction amount calculation signal is supplied to the correction amount calculation circuit 14 to put it in the correction amount calculation mode, and then when the gauge rollers 10 and 11 have rotated one rotation or more, the motor 21 is temporarily stopped, and then the correction amount calculation circuit 14
When outputs the correction voltage V _F , the motor 21 is rotated again.

Then, the value of the correction voltage V _F outputted by the correction amount calculation circuit 14 and the DC signal (measurement signal) S outputted by the AC/DC conversion circuit 13 are determined by the differential amplifier 15.
When a match with the value of
0, 11 and the motor 21 are separated. After this,
When the measurement mode is set by the operation panel 19, a measurement start signal is supplied to the correction amount calculation circuit 14 to set it to the measurement mode, and
At this time, if an absolute value display signal is supplied via the operation panel 19, the terminal 16b of the switch 16 and the common terminal 16c are connected, the ground voltage is supplied to one side of the differential amplifier 15, and the alternating voltage is supplied to the meter 17. The output value of the direct conversion circuit 13 is displayed as it is. That is, in this measurement mode, when the relative value display signal is supplied from the operation panel 19, the thickness of the plate 22 measured by the gauge rollers 10 and 11 is zero-corrected and displayed on the meter 17, and the When the absolute value display signal is supplied from the panel 19, the thickness of the plate 22 is displayed without zero correction.

Next, the operation of this embodiment configured as described above will be explained with reference to the flowchart shown in FIG. 3 and the voltage processing waveform diagram in the correction amount calculation circuit shown in FIG. 4.

Now, if you operate the operation panel 19 and set the circuit to the correction amount calculation mode at the time to shown in FIG.
The control circuit 18 executes step _S2 via step _S1 , sets the correction amount calculation circuit 14 to the correction amount calculation mode, and A/D converts the output (voltage A) of the AC/DC conversion circuit 13. After storing data as _data A, the motor ₂ is
1 to peak-hold the maximum increase Pmax and maximum decrease Pmin (see measurement signal S shown in FIG. 4) after the time to based on the output of the AC/DC conversion circuit 13 at the time to. . Next, the control circuit 18 controls the gauge rollers 10 and 11 to 1.
When the motor 21 is rotated more than one rotation, steps S ₆ and S ₇ are executed via step _S 5 to temporarily stop the motor 21 and set the current time in the correction amount calculation circuit 14.
After holding the output of the AC/DC conversion circuit 13 at _t1 , the process moves to step _S8 , where this held signal (voltage B) is A/D converted, and the data B
be memorized as Thereafter, the control circuit 18 controls the correction amount calculation circuit 14 in steps S ₉ and S ₁₀ and adds the maximum decrease Pmin (this maximum decrease) to the voltage B.
The polarity of Pmin is negative) is added, and
This addition result is A/D converted and converted into data.
The data is stored as MIN, and the maximum increment Pmax is added to the voltage B, which is A/D converted, and the conversion result is stored as data MAX. Then, the next step S ₁₁ , S ₁₂
The data MIN obtained in steps S ₉ and S ₁₀ above,
The data B obtained in step _S8 is subtracted from MAX, and the results are converted into data P _MIN and digital
Then, in step _S13 , the arithmetic average (P _MIN +P _MAX ) _/ 2 of these data P _MIN and P _MAX is calculated, and this is stored as the average value P _AVE .
Next, the control circuit 18 sends the average value _PAVE and the correction amount calculation circuit ₁₄ to the correction amount calculation circuit 14 in step S14.
The correction amount F is obtained by adding the data A obtained in step _S2 , and in step _S15 , this correction amount F is D/A converted and the correction amount calculation circuit 14 outputs a correction voltage V _F.
Then, in step _S16 , a motor drive signal is supplied to the motor control circuit 20 to connect the motor 21 and the gauge rollers 10, 11 again, and the motor 21 is energized to drive the gauge rollers 10, 11. Rotate again. As a result, the outputs of the differential transformer 12 and the AC/DC conversion circuit 13 start to fluctuate again according to the eccentricity of the gauge rollers 10 and 11, and the value of the output of the AC/DC conversion circuit 13 and the correction amount calculation circuit 14 start to fluctuate again. When the output value of the differential amplifier 15 matches the value of the output of the differential amplifier 15 and becomes zero, the control circuit 18 executes step _S18 via step _S17 , stops the motor 21, and disconnects the motor 21 and the gauge. Separate the rollers 10 and 11,
End the correction amount calculation mode.

That is, in this correction amount calculation mode, as shown in FIG. 4, the eccentricity and offset amount of the gauge rollers 10 and 11 are measured at times t ₀ to t ₁ when steps S ₂ to _{S 6} are executed. At times t ₁ to _{t 2} when subsequent steps S ₇ to _{S 15} are executed, voltages or data corresponding to each step S ₇ to S ₁₅ are obtained at times t ₇ to ts ₁₅ , and then in step S ₁₆ . The motor 21 is energized at the corresponding time _t3 , and the motor 21 is stopped at the time _t4 when the output of the AC/DC conversion circuit 13 matches the output (correction voltage V _F ) of the correction amount calculation circuit 14, and this mode is activated. The operation ends.

Next, when the operation panel 19 is operated to set the circuit to the measurement mode, the control circuit 18 executes step _S19 via step _S1 , and the correction amount calculation circuit 14
The corrected voltage V _F obtained in step _S15 is continuously outputted and held, and if a relative value display signal is supplied from the operation panel 19, the correction voltage V F obtained in step _S15 is outputted from step S20. Execute _{step 21} and connect terminal 16a of switch 16 and common terminal 16.
Keep the connection with c intact. Therefore, in this case, the thickness of the plate 22 corrected to zero is displayed on the meter 17. In addition, the control circuit 18
If the operation panel 19 is operated and an absolute value display signal is output from now on, step S22 is executed instead of step _S21 , the switch ₁₆ is changed, and the output of the AC/DC conversion circuit 13 is sent to the meter 17. Display it as is. If the mode is switched in this state, the control circuit 18 repeats the above-described operation via the first step _S1 .

Further, in the embodiment described above, steps S ₉ ,
In S ₁₀ , data P _MIN and P _MAX are obtained from voltages Pmin and Pmax using voltage B, but in this case, the voltage
The data P _MIN and P _MAX may be obtained directly from Pmin and Pmax, or the voltage A may be held, and then the voltages Pmin and Pmax are arithmetic averaged by an analog circuit, and this calculation result is used as the voltage A
The correction voltage V _F may also be directly obtained by adding it to .

Furthermore, in the embodiment described above, step _S7
In this case, the output of the AC/DC conversion circuit 13 is temporarily held, but since the motor 21 is stopped in this case, step 7 is omitted and the output of the AC/DC conversion circuit 13 is used directly.
_S8 to _S10 may also be executed.

As explained above, according to the running thickness meter according to the present invention, the diameter of the gauge roller, which is the measuring element that comes into direct contact with the object to be measured, changes overall, and the amount of displacement of the gauge roller, etc. can be measured. Offsets that occur when characteristics change on the circuit side occur can be removed, and errors caused by eccentricity of the gauge roller can be reduced, making it possible to further improve measurement accuracy.

Furthermore, in this invention, since the average amount of eccentricity is obtained when the gauge roller itself is rotated at least once to reach the initial measurement state, the correction corresponding to the amount of eccentricity of the gauge roller is made without requiring any special configuration. This has the effect that the amount can be determined easily and quickly, and measurement errors can be further reduced.

[Brief explanation of drawings]

Fig. 1 is a diagram for explaining measurement errors that occur in a roller-type running thickness meter, Fig. 2 is a block diagram showing an embodiment of a roller-type running thickness meter according to the present invention, and Fig. 3 is a diagram showing an embodiment of the roller-type running thickness meter. FIG. 4 is a flowchart for explaining the operation of the example, and is a voltage processing waveform diagram in the correction amount calculation circuit 14 shown in FIG. 2. 10, 11...Gauge roller, 12...Differential transformer (shaft distance measuring means), 14...Correction amount calculation circuit (displacement amount measurement means, change amount measurement means, averaging means, calculation means), 15...Difference dynamic amplifier (correction means), 22... plate (plate-like member);

Claims (1)

[Scope of Claims] 1. A driving method in which the thickness of the plate-shaped member is measured by obtaining the axial distance between the two gauge rollers 10 and 11 rotating in contact with the plate-shaped member 3 by a differential transformer 12 as a measurement signal S. In the thickness gauge, in the correction amount calculation mode, the two gauge rollers are brought into contact with each other, the motor 21 is energized to rotate the gauge roller at least once, and the correction amount calculation circuit 14 and the switch are activated. a control circuit 18 for controlling the reference shaft spacing 16; and a control circuit 18 for controlling the reference shaft spacing amount based on the output signal of the differential transformer during the correction amount calculation mode under the control of the control circuit; A maximum increase amount and a maximum decrease amount are obtained, and the arithmetic average is used to obtain an average change amount, and then the average change amount and the reference interval amount are added to calculate a correction amount, and the correction amount is output to the differential amplifier 15. a differential amplifier 15 which changes the switch under the control of the control circuit 18 and obtains a corrected output of the measured value S by the difference between the output of the differential transformer 12 and the output of the correction amount calculating circuit 14; A running thickness gauge characterized by comprising: