JPH05172767A - Measuring instrument for chill depth of original molten metal and inoculation amount operation device - Google Patents

Abstract

PURPOSE:To accurately calculate the chill depth and necessary inoculation amount of the original molten metal. CONSTITUTION:A wedge-shaped chill container 10 cooling the original molten metal, the thermocouple 20 arranged to a part generating no chill and detecting the temp. of a molten metal, cooling curve measuring means 31, 37, 32, 33 measuring the timewise change of the temp. of the molten metal, characteristic point detection means 32, 33 detecting primary crystal temp., supercooling temp. and eutectic temp. from a cooling curve, chill depth operation means 32, 33 operating the chill depth of the original molten metal on the basis of primary crystal temp., supercooling temp. and eutectic temp. and a chill depth display means 36 displaying chill depth are provided. Further, a characteristic storage means 33 storing the relation between the chill depth of the original molten metal and an inoculation amount after inoculation using chill depth as a parameter, an inoculation amount operation means 32 operating the inoculation amount corresponding to the chill depth of the original molten metal operated using the characteristic selected from the characteristics stored in the characteristic,y' means corresponding to the desired chill depth after inoculation and a display means 36 displaying an inoculation amount are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus capable of automatically measuring a chill depth of cast iron of a hot water from a cooling curve of the hot water and automatically calculating an inoculation amount from the chill depth in real time.

[0002]

2. Description of the Related Art Conventionally, the chill depth has been measured by pouring hot water into a wedge-shaped mold, cooling it, and after dividing the mold, taking out the chill test piece of the casting and performing visual inspection to check the chill depth. There is a way to measure.

As another method, the hot water is poured into a cylindrical container, the cooling curve of the hot water is measured by a thermocouple placed in the center of the cylindrical container, and the chill of cast iron is determined from the characteristics. I try to measure the depth. Also, the inoculation amount is 2 above
It is empirically determined from the chill depth obtained by one method.

[0004]

However, the first method described above has poor workability because it is necessary to manufacture test pieces one by one, and the chill depth is measured by visual inspection. There is a problem that measurement accuracy is poor.

The second method is to put a chill in the cast iron of the original hot water in order to measure the cooling curve of the original hot water in a relatively large cylindrical container and measure the cooling curve of the original hot water in a state where the cooling rate is slow. Does not occur. Therefore, since the cooling curve is not measured in the state where the chill occurs, the relationship between the chill depth and the cooling curve does not necessarily correlate, and it is difficult to measure the chill depth with high accuracy. The present invention was made to solve the above problems, and its purpose is to accurately measure the chill depth of Motoyu and automatically determine the optimum inoculation amount from the chill depth. That is.

[0006]

The structure of the invention for solving the above-mentioned problems is to provide a wedge-shaped chill container for pouring and cooling the extracted hot water, and a chill container in which a chill does not occur. The thermocouple that detects the temperature of the molten metal at that position, the cooling curve measuring means that measures the time change of the temperature by inputting the output from the thermocouple, and the primary crystal temperature, the supercooling temperature, and the Feature point detecting means for detecting the crystal temperature, primary crystal temperature, supercooling temperature, based on the eutectic temperature, chill depth calculating means for calculating the chill depth in the cast iron of the original hot water,
And a display means for displaying the calculated chill depth. The second characteristic is that a wedge-shaped chill container for pouring and cooling the taken-out original hot water, and a thermoelectric device installed in the chill container where chill does not occur and detecting the temperature of the molten metal at that position. Pair, and a cooling curve measuring means for measuring the time change of the temperature by inputting the output from the thermocouple, a feature point detecting means for detecting the primary crystal temperature, the supercooling temperature and the eutectic temperature from the cooling curve, and the primary crystal Chill depth calculation means that calculates the chill depth in cast iron of the original hot water based on the temperature, supercooling temperature, and eutectic temperature, and the relationship between the chill depth of the original hot water and the inoculation amount is stored with the chill depth after inoculation as a parameter. Characteristic storage means,
Inoculation for calculating the inoculation amount corresponding to the chill depth of the original hot water calculated by the chill depth calculation means using the characteristics selected in accordance with the desired post-inoculation chill depth from the characteristics stored in the characteristic storage means That is, the amount calculation means and the display means for displaying the inoculation amount are provided.

[0007]

The hot water is poured into the chill container, and the time course characteristic (cooling curve) of the temperature of the hot water is measured by the thermocouple provided at the position where chill does not occur. Next, the primary crystal temperature, the supercooling temperature, and the eutectic temperature are detected from the cooling curve of the original hot water. Then, based on the primary crystal temperature, the supercooling temperature, and the eutectic temperature,
The chill depth in the cast iron of the hot water is calculated, and the chill depth of the calculation result is visually displayed.

In the second aspect of the invention, a characteristic corresponding to a desired chill depth after inoculation is selected from a plurality of characteristics stored in the characteristic storage means, and the chill depth calculation means is selected from the characteristics. The inoculation amount corresponding to the chill depth of Motoyu calculated by is calculated and displayed visually.

[0009]

According to the present invention, the original hot water is poured into a wedge-shaped container having the same shape as when the chill test piece is manufactured, and the cooling curve of the original hot water is measured by a thermocouple placed at a position where chill does not occur. The chill depth is calculated according to the detected primary crystal temperature, supercooling temperature, and eutectic temperature. Therefore, since the cooling curve of the original hot water is measured at the position where chill does not actually occur, the correlation between the characteristics of the cooling curve and the chill depth is improved. As a result, it becomes possible to accurately predict the chill depth when cast iron is manufactured in the state of the original hot water before inoculation.

On the other hand, the second feature is that the relationship between the chill depth of the original hot water and the inoculation amount is stored in the characteristic storage means using the chill depth after inoculation as a parameter, and the chill depth after inoculation is selected from the stored plurality of characteristics. The characteristic is selected according to the desired chill depth of, and the inoculation amount corresponding to the measured chill depth of the original hot water is calculated. Therefore, since the chill depth of the molten metal after inoculation can be accurately predicted in the state of the original hot water, the inoculation amount for obtaining the desired chill depth can be accurately determined.

[0011]

EXAMPLES The present invention will be described below based on specific examples. FIG. 1 is a block diagram showing the configuration of a chill depth / inoculation dose measuring device according to an embodiment. The chill cup 10 is a container for pouring and cooling the hot water, and its detailed shape is shown in FIG. The container portion into which the hot water is poured has a wedge shape with respect to the vertical direction (Y axis), and has a rectangular shape in the lateral direction (X axis). The upper surface 11 of the chill cup 10 is provided with a recess 12 for storing an excess of the original hot water poured over the upper surface 11. When pouring hot water into the chill cup 10, excess hot water is made to overflow into the recess 12. As a result, due to the action of the recess 12, the liquid level of the hot water poured into the chill cup 10 is always constant. In this way, the molten metal surface is always kept constant and the cooling curve can be measured under the same conditions.

The thermocouple 20 is arranged at a central position in the lateral direction (X axis) of the chill cup 10 and at a height position sufficient to remove the chilled portion at the tip of the wedge shape in the longitudinal direction (Y axis). ing. The thermocouple 20 is connected to the temperature detector 31. The analog detected temperature output from the temperature detector 31 is input to the A / D converter 37, sampled and converted into a digital detected temperature. The detected temperature of the digital amount is read by the CPU 32. CP
A ROM 33, a RAM 34, and an input / output interface 35 are connected to the U32.
A CRT 36 is connected to.

The ROM 33 has a program area 33 in which a program for calculating the chill depth and the inoculation amount is stored.
1, a calculation formula region 332 that stores a calculation formula for calculating the chill depth, and an inoculation amount characteristic region 3 that stores the relationship between the inoculation amount with the post-inoculation chill depth as a parameter and the chill depth of Motoyu
And 33 are formed. Further, the RAM 34 has a detection temperature region 341 for storing the detected temperature and a characteristic temperature region 342 for storing the characteristic temperatures of the primary crystal temperature, the supercooling temperature and the eutectic temperature detected from the cooling curve. ..

Next, the processing procedure of the CPU 32 will be described with reference to the flowcharts of FIGS. 3, 4 and 5. When the device 30 is reset and started, the flags G1 and G
2, G3 are all initialized to 0. Next, the hot water is poured into the chill cup 10 and cooled. When the device 30 is reset and started, the program shown in FIG. 3 is executed at predetermined minute time intervals.

In step 100, the A / D converter 3
The detected temperature output by 2 is input. This detected temperature is
The detection temperature areas 341 are sequentially stored in order of oldness. next,
In step 102, it is determined whether the flag G1 indicating that the primary crystal temperature detection is completed is 1, that is, whether the primary crystal temperature detection is completed. If the primary crystal temperature detection is not completed, the process proceeds to step 104 and the primary crystal temperature detection process is executed. In step 106, it is determined whether or not the primary crystal temperature detection process is completed in the current execution cycle. If the primary crystal temperature detection is not completed, step 1
08, the primary crystal detection flag G1 is set to 0 indicating that the detection is not completed, and when the detection of the primary crystal temperature is completed, the processing proceeds to step 110 and the primary crystal detection flag G1 is set to 1 indicating the detection completion. Then, the execution cycle of this time is ended.

In step 102, if the primary crystal detection flag G1 is 1 in the current execution cycle, that is, if the primary crystal temperature detection has already been completed, step 112 and the following steps are executed. The processing of steps 112 to 120 is
It is a processing procedure for detecting the supercooling temperature. The procedure is Step 102 to Step 110, which is the procedure for detecting the primary crystal temperature.
Is the same as. Of these, in step 114, the process for detecting the supercooling temperature is executed.

If the supercooling detection flag G2 is 1 in the current execution cycle in step 122, that is, if the supercooling temperature detection has already been completed, step 122 and subsequent steps are executed. The processing of steps 122 to 130 is
It is a processing procedure for eutectic temperature detection. The procedure is Step 102 to Step 110, which is the procedure for detecting the primary crystal temperature.
Is the same as. Of these, in step 126, the process for detecting the eutectic temperature is executed.

Next, the procedure for detecting the primary crystal temperature, the supercooling temperature, and the eutectic temperature executed in steps 104, 114, and 124 will be described. The primary crystal temperature, the supercooling temperature, and the eutectic temperature are defined as temperature stagnation points in the cooling curve shown in FIG. This stagnation point is a point existing in a section where the differential coefficient of the cooling curve exists in a certain range. Hereinafter, this section is referred to as a stagnant section. The distinction between primary crystal, supercooling, and eutectic is determined by the order in which stagnant sections appear, the stagnant time, and whether the cooling curve changes upward or downward after exiting the stagnant section.

For example, the stagnation section is a range in which the differential coefficient of the cooling curve exists within the range of ± 1 ° F / sec and the duration of time is 0.66 seconds or more. Further, the primary crystal temperature is the first stagnant section, the stagnant section is smaller than 0.66 seconds, and is detected as an intermediate value of the stagnant section in which the curve moves downward after leaving the stagnant section. Further, the supercooling temperature is the first or second stagnation section, and the minimum value of the stagnation section where the curve moves upward after exiting the stagnation section, or when the above conditions are not satisfied , Of the stagnation sections where the eutectic temperature is detected, the eutectic temperature is detected as the minimum value that appears earlier than the eutectic temperature. Also, the eutectic temperature is the second or third stagnation section, the maximum value of the stagnation section where the curve moves downward after exiting the stagnation section, or the first value of 1.65. It is detected as the maximum value of the stagnant section that continues for more than a second. The detected primary crystal temperature, supercooling temperature, and eutectic temperature are stored in the characteristic temperature area 342.

Next, the procedure for calculating the chill depth of the original hot water from the detected primary crystal temperature, supercooling temperature, and eutectic temperature will be described. When the detection of the characteristic temperature is completed, the program shown in FIG. 5 is executed. In step 200, the chill depth D is calculated by the following formula stored in the calculation formula area 332.

[Equation 1] D = (TL-TC-120) × (TE-TC) × S / (TC-2000) (1) where TL is the primary crystal temperature, TC is the supercooling temperature, and TE is the eutectic temperature. All units are ° F. Also, S is a coefficient, TL <21
S = 0.2 for 50 ° F, S for TL> 2150 ° F
= 0.8.

A chill test piece having the same shape as that of the chill cup 10 was prepared by using the chilled hot water of various components used to determine the chill depth D of the hot water by measuring the cooling curve using the chilled cup 10. Then, the actual chill depth of the chilled toe piece was measured with respect to the hot water of the various components. Then, the relationship between the calculated chill depth D of the Motoyu and the actual chill depth was measured. The result is shown in FIG. As described above, it is understood that the chill depth D of the hot water calculated by the above formula accurately represents the actual chill depth.

When the original hot water is poured into a cylindrical container and the cooling curve of the original hot water is measured, the correlation between the chill depth and the degree of supercooling, which is the difference between the supercooling temperature and the eutectic temperature, is found. I couldn't get it. In the case of this cylindrical container, since the degree of chilling varies depending on the cooling rate, it was not possible to obtain a constant cooling curve governed only by the original hot water components. The inventors of the present invention measured the cooling curve of the original hot water in a state in which a certain amount of chills that forcedly depend only on the components of the original hot water were generated by using a wedge-shaped container. It has been found that it depends only on. Then, they found that there was a strong correlation between the chill depth and the primary crystal temperature, the supercooling temperature, and the eutectic temperature of the cooling curve measured in that state. Although it was understood that the chill depth and the above formula (1) can be measured well, the present invention does not limit the calculation formula to the formula (1), but limits each constant to the above formula. is not. Firstly, it was found that the chill depth D changes in proportion to the difference between the eutectic temperature TE and the supercooling temperature TC, that is, the degree of supercooling (TE-TC). Then, in the equation (1), the proportional coefficient is determined by a function of the primary crystal temperature TL and the supercooling temperature TC.

Next, in step 202, the calculated chill depth D is displayed on the CRT 36. Next, in step 204, the desired chill depth Dd required in the hot water after inoculation is input. Next, in step 206, a characteristic showing the relationship between the inoculation amount W corresponding to the desired chill depth Dd and the calculated chill depth D of the original hot water from among the plurality of characteristics stored in the inoculation amount characteristic region 333. Is selected.

The plurality of characteristics stored in the inoculation amount characteristic region 333 are as shown in FIG. 7, and show the relationship between the inoculation amount with the post-inoculation chill depth as a parameter and the calculated chill depth of Motoyu. It is a characteristic to show. Next, in step 208, the inoculation amount W corresponding to the calculated chill depth D of the original hot water is determined from the selected characteristics. A desired chill depth Dd can be obtained by inoculating Motoyu with this inoculation amount W. next,
In step 210, the inoculation dose W is displayed on the CRT 36.

Next, the inoculation amount W calculated in this way
Based on the above, the automatic inoculant injection device is operated to perform automatic inoculation.

As described above, the cooling curve of the original hot water was measured by using the wedge-shaped chill cup, and the primary crystal temperature of the cooling curve,
The chill depth of the hot water is calculated from the supercooling temperature and the eutectic temperature.
Therefore, the chill depth of the original hot water can be detected easily and accurately without making a test piece. In addition, the inoculation amount necessary to obtain the desired chill depth after inoculation from the calculated chill depth of Motoyu is calculated from a plurality of characteristics. Therefore, the predictability of the chill depth after inoculation becomes high, and the quality control ability of the product is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a chill depth / inoculation dose measuring device according to a specific embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a chill cup used in the apparatus of the embodiment.

FIG. 3 is a flowchart showing a processing procedure of a CPU used in the apparatus of the embodiment.

FIG. 4 is a flowchart showing a processing procedure of a CPU used in the apparatus of the embodiment.

FIG. 5 is a flowchart showing a processing procedure of a CPU used in the apparatus of the embodiment.

FIG. 6 is an explanatory diagram showing an example of a cooling curve.

FIG. 7 is a characteristic diagram showing the relationship between the chill depth of Motoyu and the inoculation amount calculated using the chill depth after inoculation as a parameter.

FIG. 8 is a measurement diagram showing the relationship between the calculated chill depth of the hot water and the actual chill depth.

[Short description of reference numeral] 10 ... Chill cup 11 ... Upper surface 12 ... Recess 20 ... Thermocouple 32 ... CPU 34 ... RAM

Front page continued (72) Inventor Takeshi Adachi Aisin Takaoka Co., Ltd.

Claims (2)

[Claims] 1. A wedge-shaped chill container for pouring and cooling the taken-out original hot water, a thermocouple installed in a portion where chill does not occur in the chill container, and detecting the temperature of the molten metal at that position, Cooling curve measuring means for measuring the time change of temperature by inputting the output from the thermocouple, feature point detecting means for detecting the primary crystal temperature, the supercooling temperature, and the eutectic temperature from the cooling curve, the primary crystal A chill depth measuring device for a hot water, comprising: a chill depth calculating means for calculating a chill depth in cast iron of the hot water based on a temperature, a supercooling temperature, and a eutectic temperature, and a display means for displaying the calculated chill depth. 2. A wedge-shaped chill container for pouring and cooling the taken out hot water, a thermocouple installed in a chill-free portion of the chill container for detecting the temperature of the molten metal at that position, Cooling curve measuring means for measuring the time change of temperature by inputting the output from the thermocouple, feature point detecting means for detecting the primary crystal temperature, the supercooling temperature, and the eutectic temperature from the cooling curve, the primary crystal Chill depth calculation means that calculates the chill depth in cast iron of the original hot water based on the temperature, supercooling temperature, and eutectic temperature, and the relationship between the chill depth of the original hot water and the inoculum amount is stored with the chill depth after inoculation as a parameter. The characteristic storage means and the characteristic selected according to the desired post-inoculation chill depth from among the characteristics stored in the characteristic storage means, to the chill depth of the original hot water calculated by the chill depth calculation means. Calculate the corresponding inoculation dose An inoculation amount calculation device comprising: an inoculation amount calculating means for displaying the inoculation amount;