JP2014034058A - System and method for control of casting quality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control casting quality, and furthermore quality of castings, by successively measuring a temperature of a molten metal in teeming.SOLUTION: A casting quality control system is a system for measuring a temperature of a molten metal poured from a ladle to a mold and controlling casting quality based on the temperature. The system is configured by providing a thermometer immersed in the molten metal in pouring opening of the ladle, successively measuring the temperature of the molten metal passing through the pouring opening and poured in each mold by the thermometer, controlling the successively measured temperature data in association with each data, and feeding back the data to each mold.

Description

  The present invention relates to a technique for measuring the temperature of molten metal poured into a plurality of molds from a ladle and managing the casting quality in each mold based on the temperatures.

Patent Document 1 discloses a technique that estimates a temperature drop associated with tapping from the furnace and contributes to improving the quality of the casting by matching the temperature of the molten metal at the time of pouring into the mold to an appropriate temperature.
In patent document 1, while considering the temperature drop amount resulting from the ladle temperature at the time of tapping, and the temperature drop amount resulting from the operation conditions, the temperature drop amount of the molten metal is estimated, and the time required for pouring according to the operation conditions Thus, based on these results, the amount of decrease in the molten metal temperature that occurs in the entire process is obtained, whereby the molten metal temperature is managed to control the casting quality.

  Moreover, in a general automatic pouring line, the casting quality is controlled by measuring the pouring temperature for each frame using a radiation thermometer.

Japanese Patent Laid-Open No. 9-201666

The molten metal placed in the ladle has a temperature distribution, and the temperature in the ladle inner wall, the center, and the vicinity of the pouring spout may vary significantly, so the temperature of the molten metal that is actually poured can be accurately estimated, etc. It was difficult to do. For these reasons, it has been difficult to prevent the occurrence of defects due to variations in molten metal temperature in a series of casting processes.
Also, the radiation thermometer is very difficult to install and the measurement accuracy is not good. Therefore, the pouring temperature for each frame cannot be managed with high accuracy, and the causal relationship cannot be specified even if a casting defect due to the molten metal temperature occurs.

  The casting quality control system of the present invention is a system for measuring the temperature of molten metal poured from a ladle into a plurality of molds and managing the casting quality in each mold based on the temperature, and the pouring spout of the ladle Provided with a thermometer immersed in the molten metal, and continuously measured the temperature of the molten metal passed through the pouring port by the thermometer and poured into each mold, and the temperature data measured continuously Management is performed in association with each mold, and feedback is provided for each mold.

  In the continuously measured temperature data, a point at which the temperature suddenly rises is determined as a casting start time, a point at which the temperature suddenly falls is determined as a casting end time, and casting from the casting start time to the casting end time is cast into each mold. Manage casting quality as time.

  The casting quality control method of the present invention is a method for measuring the temperature of molten metal poured from a ladle into a plurality of molds and managing the casting quality in each mold based on the temperature, and the pouring spout of the ladle Provided with a thermometer immersed in the molten metal, and continuously measured the temperature of the molten metal passed through the pouring port by the thermometer and poured into each mold, and the temperature data measured continuously Management is performed in association with each mold, and feedback is provided for each mold.

  In the continuously measured temperature data, a point at which the temperature suddenly rises is determined as a casting start time, a point at which the temperature suddenly falls is determined as a casting end time, and casting from the casting start time to the casting end time is cast into each mold. Manage casting quality as time.

  According to the present invention, the molten metal temperature at the time of the actual pouring is continuously measured, and the temperature data and the mold are managed in association with each other, thereby accurately controlling the casting quality and eventually the casting quality. it can.

It is a figure which shows a casting line. It is a figure which shows the structure of a ladle and a molten metal temperature measurement system. It is a block diagram which shows the molten metal temperature measurement system provided in a casting line. It is a figure which shows the inclination of the thermometer at the time of pouring a molten metal into a casting_mold | template. It is a graph which shows the measurement result by the thermometer in a series of casting processes in a casting line. It is a graph which shows an example of casting quality control using the measurement result by a thermometer. It is a graph which shows another example of casting quality control using the measurement result by a thermometer.

  FIG. 1 shows a casting line 1. The casting line 1 is a production line that performs a series of casting processes for producing a casting according to the mold shape by casting molten metal into the mold 2 and holding it in the mold 2 for a predetermined time.

As shown in FIG. 1, a plurality of molds 2 are arranged on the casting line 1 in a state in which the molten metal inlets 3 are arranged in a line with the melt inlet 3 facing one side. A molten metal 6, which is a molten metal, is placed in a ladle 5 suspended from the hanger 4. The hanger 4 is attached with a moving device (not shown) such as a crane that can move in the plane direction.
The operator turns the handle 7 of the ladle 5 to tilt the ladle 5 and pours the molten metal 6 toward the molten metal inlet 3 of the mold 2. When casting into one mold 2 is completed, the ladle 5 is moved so as to align the position with the next mold 2. This operation is repeated to perform a series of casting operations.

FIG. 2 shows the structure of the ladle 5 and the temperature measurement system 10. FIG. 3 shows an apparatus configuration of the temperature measurement system 10.
The temperature measurement system 10 measures the outlet temperature of the molten metal 6 poured from the ladle 5 into the mold 2. At the same time, the temperature measurement system 10 records and displays the measurement result.

As shown in FIG. 2, a thermometer 11 is provided at the pouring port 8 of the ladle 5, and the temperature of the molten metal 6 passing through the pouring port 8 is continuously measured by the thermometer 11.
The thermometer 11 includes an immersion 12 provided at the tip. The immersion 12 is a temperature measurement unit including a thermocouple capable of measuring the temperature range of the molten metal 6.

The thermometer 11 is an immersion type thermometer that continuously measures the temperature by immersing the immersion 12 at the tip in the molten metal 6. Since the immersion 12 is used as a consumable item, it is detachably attached to the tip of the thermometer 11.
In this way, by using the thermometer 11 having the measurement part as the immersion 12 that is continuously immersed in the molten metal 6 during pouring and directly measures the temperature, the temperature can be measured with high accuracy.

The thermometer 11 is attached to the edge of the ladle 5 via the base 13, the holder 14, and the attachment portion 15.
The base 13 is detachably attached to the edge of the ladle 5, and two bases 13 are arranged at symmetrical positions across the pouring gate 8. The base 13 has, for example, a U-shaped or O-shaped support portion, and supports the holder 14 so as to be swingable by supporting the holder 14 with the support portion. The number of the bases 13 may be one, and the holder 14 and the attachment portion 15 may be supported at one point.
The holder 14 is a cylindrical member that is passed between the bases 13 and 13, and the attachment portion 15 is fixed at the center. The attachment portion 15 is a cylindrical member that extends downward from the center of the holder 14, that is, toward the molten metal 6. An immersion 12 (thermometer 11) is detachably attached to the tip of the attachment portion 15. The holder 14 may be fixed to the base 13 and the mounting portion 15 may be swingable with respect to the holder 14.

When the ladle 5 is tilted during pouring, the base 13 attached to the ladle 5 is tilted, the holder 14 rotates, and the mounting portion 15 swings (or the mounting portion 15 swings). At this time, the thermometer 11 assumes a vertical posture according to gravity. In this way, by supporting the thermometer 11 so as to be able to swing and maintaining the thermometer 11 at a position above the pouring port 8, the immersion 12 is always in contact with the molten metal 6 in the middle of pouring and can maintain a state where it is immersed. Yes (see FIG. 4).
As described above, the thermometer 11 is attached to a position where it can contact the molten metal 6 being poured into the mold 2 from the pouring port 8 of the ladle 5 and the position of the immersion 12 provided at the tip of the thermometer 11. Can change the relative position with respect to the ladle 5 according to the inclination at the time of pouring of the ladle 5, and by continuously contacting the molten metal 6 passing through the pouring port 8 by changing the position, It is possible to continuously measure the temperature of the molten metal 6 during pouring.

When there is much quantity of the molten metal 6 in the ladle 5, the inclination of the ladle 5 becomes small. In such a case, as shown in FIGS. 4A and 4B, the immersion 12 can be surely immersed in the molten metal 6 by installing the thermometer 11 at a predetermined angle. That is, by installing the thermometer 11 so that the angle does not become smaller than a predetermined angle, the distance from the pouring port 8 can be prevented from becoming too large. At the same time, the thermometer 11 is installed so that the angle of the thermometer 11 does not become larger than a predetermined angle in order to prevent the immersion 12 from moving away from the molten metal 6 by the momentum of pouring.
In this way, the position of the immersion 12 of the thermometer 11 can be fixed within an arbitrary angle range, so that the tilt angle of the ladle 5, the remaining amount of the molten metal 6, the momentum, etc. can be automatically considered. The structure which can always contact with the molten metal 6 is realizable.
For example, this can be realized by providing a stopper between the base 13 and the holder 14 so that the rotation angle of the holder 14 falls within a predetermined angle range.

  Further, as described above, the mounting angle of the thermometer 11 may be fixed by providing a stopper between the base 13 and the holder 14. That is, the position of the immersion 12 may be fixed at an arbitrary angle. In this case, the attachment structure of the thermometer 11 can be simplified. For example, when the molten metal 6 is automatically poured, it is suitable when the flow of the molten metal 6 is constant.

As shown in FIGS. 2 and 3, a compensation lead wire 16 is connected to the immersion 12. The compensating lead wire 16 is drawn out to the handle 7 side through the inside of the mounting portion 15 and the holder 14 configured in a cylindrical shape, and is connected to the transmission unit 17. The transmission unit 17 is an electronic device that transmits an electric signal by wireless communication. The transmission unit 17 is detachably attached to the ladle 5. The installation position of the transmission unit 17 is not limited to this, and the transmission unit 17 may be attached to a position such as the hanger 4 that is not affected by the inclination of the ladle 5.
The temperature data of the molten metal 6 measured by the thermometer 11 is converted into an electric signal and transmitted to the transmission unit 17. Thus, the temperature data of the molten metal 6 is transmitted from the transmission unit 17 as an electrical signal.

As shown in FIG.2 and FIG.3, the electric signal transmitted from the transmission unit 17 is received by the receiving unit 20 provided in the position away from the ladle 5 (casting line 1). The receiving unit 20 is connected to the personal computer 21 and transmits an electrical signal related to the temperature of the molten metal 6 received from the transmitting unit 17 to the personal computer 21. The personal computer 21 is a general personal computer having an HDD, a CPU, and the like.
The personal computer 21 converts the electrical signal received by the receiving unit 20 into temperature data, automatically records it in time series, and displays the measurement result on the display device 22. The display device 22 is installed in the casting line 1 such as in the vicinity of the ladle 5 and is used for performing temperature management during pouring in real time.

  As described above, the temperature of the molten metal 6 at the time of pouring is measured, the temperature data is recorded in the personal computer 21 via the wireless communication (transmitting unit 17 and receiving unit 20), and further displayed on the display device 22. Thus, the temperature control of the molten metal 6 for each mold 2 can be clearly performed.

In addition, by controlling the temperature of the molten metal 6, troubles such as gas defects that occur when the pouring temperature is low, poor water circulation, and shrinkage nests and seizures that occur when the pouring temperature is high. Can be prevented. In this way, by performing the correlation analysis between the pouring temperature and the occurrence of defects, the management range of the pouring temperature can be optimized for each model, and the quality can be improved.
Furthermore, by continuously measuring the temperature of the molten metal 6 during pouring, the time required for pouring (casting time) can be specified, and the casting time can be managed. Thereby, it is possible to prevent problems such as gas defects and poor hot water that occur when the casting time is long. As described above, by managing the casting time, it is possible to reduce work variation.

  Temperature data obtained on a one-to-one basis for the molds 2-1 to 2-6 is recorded in the personal computer 21 as data associated with each mold 2. By managing the castings obtained from the molds 2-1 to 2-6 in a series of casting processes with serial numbers, when defective products are found, they are fed back to specific molds, pouring conditions, etc. It is possible to specify the conditions that cause At the same time, it is possible to contribute to the quality assurance of the casting by associating the data related to the casting quality of the casting with the temperature data recorded in the personal computer 21.

  FIG. 5 to FIG. 7 show an example of the measurement result of the thermometer 11 in a series of casting processes and a casting quality control using the measurement result. The result of having measured the temperature of the molten metal 6 at the time of pouring using the thermometer 11 when casting the molten metal 6 continuously in the six casting_mold | templates 2 (2-1 to 2-6) is shown. As shown in FIG. 5, the temperature rapidly increases when the immersion 12 is immersed in the molten metal 6, and the temperature rapidly decreases when the immersion 12 is separated from the molten metal 6.

As shown in FIG. 6, the quality of casting is controlled by determining whether or not the temperature of the molten metal 6 during pouring is within an appropriate temperature range. When it is not within the predetermined temperature range, it is determined as a defect due to the molten metal temperature.
Further, as shown in FIG. 7, a point at which the temperature rapidly rises is managed as a casting start time, and a point at which the temperature suddenly falls is regarded as a casting end time, and this time is managed as a casting time. If the casting time exceeds a predetermined length, it is determined as a defect due to the casting time.
As described above, the cause of the failure is specified by feeding back the temperature data continuously measured by the thermometer 11.

In the above embodiments, the thermometer 11 is dipped from above into the pouring port 8 of the ladle 5, but the immersion 6 is applied to the molten metal 6 that passes through the pouring port 8 regardless of the inclination of the ladle 5. The thermometer 11 may be attached so that the immersion 12 can come into contact with the molten metal 6 from the side of the pouring port 8 or from the lower side as long as 12 is disposed at a position where it can always contact.
Moreover, the specific apparatus configuration of the temperature measurement system 10 such as the manner in which the thermometer 11 is attached to the ladle 5 is not limited to the above-described one, and depends on the inclination of the ladle 5, the amount of the molten metal 6, the flow, and the like. As long as the immersion 12 that is the temperature measuring part of the thermometer 11 can be always immersed in the molten metal 6 at the time of pouring, it is sufficient.

  1: casting line, 2: mold, 5: ladle, 6: molten metal, 8: pouring spout, 10: temperature measuring system, 11: thermometer, 12: immersion

Claims (4)

A system that measures the temperature of the molten metal poured into a plurality of molds from a ladle and manages the casting quality in each mold based on the temperature,
A thermometer that is immersed in the molten metal is provided in the pouring port of the ladle, the temperature meter passes through the pouring port, and continuously measures the temperature of the molten metal poured into each mold,
A casting quality control system characterized in that the continuously measured temperature data is managed in association with each mold and fed back to each mold.   In the continuously measured temperature data, a point at which the temperature suddenly rises is determined as a casting start time, a point at which the temperature suddenly falls is determined as a casting end time, and casting from the casting start time to the casting end time is cast into each mold. The casting quality control system according to claim 1, wherein the casting quality is managed as time. A method of measuring the temperature of the molten metal poured into a plurality of molds from a ladle and managing the casting quality in each mold based on the temperature,
A thermometer that is immersed in the molten metal is provided in the pouring port of the ladle, the temperature meter passes through the pouring port, and continuously measures the temperature of the molten metal poured into each mold,
A casting quality control method characterized in that the continuously measured temperature data is managed in association with each mold and fed back to each mold.   In the continuously measured temperature data, a point at which the temperature suddenly rises is determined as a casting start time, a point at which the temperature suddenly falls is determined as a casting end time, and casting from the casting start time to the casting end time is cast into each mold. The casting quality control method according to claim 3, wherein the casting quality is managed as time.

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