JPS5937323Y2 - Internal molten state detection device for castings - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an apparatus for detecting the shape of a molten part remaining inside a cast product during solidification in a continuous casting process or the like.

In the continuous casting process, long L rod-shaped slabs are produced by sequentially cooling and solidifying the castings.

In the process of cooling and solidifying this slab, cooling naturally progresses from the outside to the inside of the slab, so even if the outside has already solidified, there will still be some molten parts left inside. .

Controlling the process in which the molten parts remaining inside the slab gradually solidify by cooling, etc. according to a predetermined program is considered an important issue in maintaining the quality of castings, but it has not yet been realized at present. Not yet.

The reason for this is that in order to perform the above control, it is first necessary to detect the distribution state of the molten zone in advance, but since this detection exists inside the slab, there is no way to determine the molten zone from the outside. There are many things that can be mentioned.

This idea was developed in view of the above-mentioned conventional circumstances, and utilizes the difference in ultrasonic transmission characteristics between the solid metal state and the liquid state to detect the distribution shape of the molten part inside the slab. It is something.

Hereinafter, the structure of one embodiment of the device for detecting the internal molten state of a casting according to this invention will be described in detail with reference to the drawings.

In the figure, 1 is a casting that moves continuously in the direction of the arrow in the figure, 2 is a molten portion remaining in the casting 1, and 3.4 is a fountain 3a that constitutes a transmission medium for the casting 1.

A plurality of ultrasonic transmitters and ultrasonic receivers facing each other via 4a, 5 a power source for driving each ultrasonic transmitter 3, 6 a plurality of amplifying signals received by each ultrasonic receiver 4, respectively. 7 is a detection circuit that compares the signal value amplified by each amplifier circuit 6 with a preset signal reference value and detects the amount of attenuation of the ultrasonic wave at each position. constitutes a comparison circuit 8.

9 is a processing circuit that determines the distribution of the amount of attenuation of the ultrasonic waves detected by each comparison circuit 8 and extracts the shape of the molten part 2 existing inside the casting 1.

Compared to when ultrasonic waves propagate through normal solid metal, when there is metal molten at a high temperature, the passing ultrasonic waves are attenuated due to scattering of many particles and bubbles in the molten metal. receive.

It is thought that the amount of ultrasound transmitted depends on the size of the melted part.

Also in the embodiment of this invention constructed as shown in the above figure, the respective ultrasonic transmitters 3 and ultrasonic receivers 4 are placed facing each other on both sides of the casting 1, so that they are transmitted with the same energy. However, it is clear that the energy of the ultrasonic waves that reach the ultrasonic receiver 4 differs depending on the position, and in the case of the figure, as the cooling progresses, the melted part 2 becomes smaller and the amount of ultrasonic waves transmitted decreases. increases.

The ultrasonic energy that has reached each ultrasonic receiver 4 is converted to the magnitude of an electric signal, and after being amplified by each amplifier 6, this electric signal value is compared with a preset signal reference value in each detection circuit 7, and each The amount of attenuation of the ultrasonic wave at the position is detected.

Furthermore, the processing circuit 9 analyzes the distribution of these attenuation amounts to determine the molten zone 2.
The shape can be extracted and output in a predetermined output format.

In addition, each fountain 3at4a is connected to the casting 2 from the ultrasonic transmitter 3.
, the casting 2 also serves as a transmission medium for injecting and extracting ultrasonic energy from the ultrasonic receiver 4.

Further, in the above embodiment, the attenuation amount is detected by comparing the ultrasonic energy received by each ultrasonic receiver 4 with a reference value set in advance in each detection circuit 7, but each ultrasonic wave Depending on the case, it is also possible to detect the amount of attenuation only by relative comparison of the ultrasonic energies received by the receiver 4.

Furthermore, ultrasonic waves can be transmitted and received using either continuous waves or pulsed waves, and in order to avoid noise and mutual interference between the transmitting and receiving systems, continuous waves may be given a unique frequency, while pulsed waves may be given specific characteristics in the receiving circuit. It goes without saying that signal processing means such as using a gate pulse matched to the timing at which the signal arrives at the receiver can be applied.

In summary, the device for detecting the internal molten state of a casting according to this invention detects the distribution of the amount of ultrasound transmitted and extracts the shape of the molten part remaining inside the casting, which was difficult to do in the past. This method has a great practical effect in that it makes it possible to control the molten state inside the cast product according to a predetermined program during the continuous casting process.

[Brief explanation of drawings]

The figure is an explanatory view showing the configuration of the internal molten state detection device for a casting according to this invention. In the figure, 1 is a casting, 2 is a melting part, 3 is an ultrasonic transmitter, 4 is an ultrasonic receiver, 3a and 4a are fountains forming a heat transfer medium, 8 is a comparison circuit, and 9 is a processing circuit. . Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A plurality of pairs of ultrasonic transmitters and ultrasonic receivers are arranged facing each other along the movement direction on both sides of the continuously moving casting via a transmission medium consisting of a fountain, and the ultrasonic receiver receives signals. A plurality of comparison circuits detect the amount of attenuation of the ultrasonic waves by comparing the amount of ultrasonic waves generated with a preset reference amount, and the inside of the casting is determined based on the distribution of the amount of attenuation compared by each of the comparison circuits. A processing circuit for calculating the shape of a molten part of a casting.