JPH0570536B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for horizontal continuous casting of metal tubes.

[Prior art] Regarding the continuous casting method of metal tubes, Japanese Patent Application Laid-Open No. 1986-
As described in Publication No. 54255, a molding device is installed at the pouring port of a molten metal holding furnace, the molten metal is cooled in this molding device to form a casting tube, and this casting tube is drawn and cast by a drawing roller device. .

[Problems to be Solved by the Invention] Incidentally, the above-mentioned cast pipe needs to be appropriately solidified in a molding device before being drawn out.

If the drawing speed is too slow, the solidification and shrinkage of the cast tube in the mold will be excessive, resulting in excessive adhesion and friction between the inner surface of the cast tube and the core of the molding device, resulting in damage to the cast tube. If a breakout or breakage of the core occurs and the drawing speed is too fast, the solidification and shrinkage of the molten metal in the mold will not be sufficient, resulting in flaws, holes, breakouts, etc. in the cast tube. arise.

Furthermore, JP-A-60-15427 states that when continuously casting a solid bar, the surface temperature of the cast bar at the outlet side of the mold device is measured, and if the surface temperature is higher than the reference temperature, the drawing waiting time is determined. Techniques have been disclosed that prevent hot water from leaking by increasing the temperature, and if the surface temperature is lower than a reference temperature, shorten the waiting time for extraction to prevent overcooling.

However, even if the above-mentioned conventional technology is applied to continuous casting of metal tubes, it is not possible to accurately estimate the contact state between the inner surface of the cast tube and the core portion of the mold device based only on the surface temperature state of the cast tube.

An object of the present invention is to appropriately solidify a cast pipe within a mold device and stably draw and cast the pipe.

[Means for Solving the Problems] The present invention as set forth in claim 1 provides a metal pipe in which a molten metal contained in a molten metal holding furnace is solidified into a tubular shape in a molding device to form a cast pipe, and the cast pipe is drawn out. In the horizontal continuous casting method, the pull-out load of the cast pipe is measured,
The pull-out control is performed so that if the pull-out load is larger than a predetermined standard pull-out load, the pull-out speed is increased, and if the pull-out load is smaller than the pre-determined reference pull-out load, the pull-out speed is decreased. It is.

The present invention as set forth in claim 2 is characterized in that the molten metal contained in the molten metal holding furnace is solidified into a tubular shape using a molding device to form a cast tube, and the cast tube is pulled out at a constant drawing speed during the drawing time. In the horizontal continuous casting method for metal tubes, which repeats one cycle of stopping drawing during the waiting period, the drawing load of the cast tube is measured, and in a steady state where the drawing load is approximately equal to a predetermined standard drawing load, the above drawing is performed. time and waiting time
In a steady drawing process where tw is predetermined Teo and two, and in a state where the pullout load is larger than the predetermined standard pullout load, the above pullout time te is maintained at teo,
A high-load pulling process in which the waiting time tw is made shorter than two, and a low-load pulling process in which the waiting time tw is kept longer than two while the pulling time te is maintained at teo in a state where the pulling load is smaller than a predetermined standard pulling load. This includes a load pulling process.

The present invention according to claim 3 includes a mold device that is disposed at the pouring port of a molten metal holding furnace and that solidifies the molten metal into a tubular shape to form a cast pipe, and a mold device that forms a cast pipe by pulling out the cast pipe formed by the mold device. In a horizontal continuous casting machine for metal tubes having a drawing roller device, the drawing load measuring device measures the drawing load of the cast tube by the drawing roller device, and the measurement results of the drawing load measuring device are obtained, and the drawing load is determined. and a control device for controlling the pulling so that the pulling speed is increased if the pulling load is larger than a predetermined standard pulling load, and the pulling speed is decreased if the pulling load is smaller than the predetermined standard pulling load. It was made so that it would become so.

[Function] According to the present invention as set forth in claims 1 and 3, if the measured pull-out load is larger than the predetermined reference pull-out load, "solidification shrinkage of the cast pipe in the mold is excessive, and the inner surface of the cast pipe is It was determined that "excessive adhesive force and frictional force were generated between the tube and the core part of the molding device," and the drawing speed was increased so as to weaken the cooling that the casting device applied to the cast tube. Also, if the measured pull-out load is smaller than the predetermined standard pull-out load,
It is determined that "the solidification shrinkage within the mold is not sufficient", and the drawing speed is reduced so that the mold device strengthens the cooling provided to the cast tube. Therefore,...
As a result, the cast pipe can be appropriately solidified in the mold device and drawn and cast stably, without causing breakout of the cast pipe or damage to the mold device (core portion).

Further, according to the present invention as set forth in claim 2, in a state where the measured drawing load is larger than the predetermined standard drawing load, "the solidification shrinkage of the cast pipe in the mold is excessive, and the inner surface of the cast pipe is It was determined that the process was during a high-load drawing process that caused excessive adhesive force and frictional force between the molding machine and the core part of the machine, and the drawing waiting time was shortened to weaken the cooling that the molding machine applies to the cast pipe. do. In addition, if the measured drawing load is smaller than the predetermined reference drawing load, it is determined that the mold is in the low-load drawing process where solidification and shrinkage is not sufficient in the mold, and the cooling applied to the cast pipe by the mold equipment is reduced. Increase the waiting time for extraction to strengthen the condition. In addition, when the drawing operation of the cast pipe is performed intermittently with one cycle of drawing/stopping of drawing as in the present invention as set forth in claim 2, the cooling effect applied to the casting pipe by the mold device is performed at the time of stopping the drawing. (that is, during the above-mentioned withdrawal waiting time). Therefore, the casting pipe can be appropriately solidified in the molding device and stably drawn and cast.
There is no breakout of the casting tube or damage to the mold device (core part).

[Embodiment] FIG. 1 is a control system diagram showing an embodiment of the present invention.
FIG. 2 is a sectional view showing the mold device, and FIG. 3 is an end view showing the mold device.

As shown in FIG. 1, the continuous casting apparatus 10 includes a molding device 13 attached to a pouring port 12 formed at the lower side of a molten metal holding furnace 11. The continuous casting device 10 cools the molten metal using a mold device 13 to form a casting tube 14, which is drawn and cast.

The continuous casting device 10 includes a guide roller 15 that supports the casting tube 14 on the exit side of the casting device 13, and also includes a drawing roller device 16 for pulling out the casting tube 14. Pulling roller device 16
consists of a pinch roller 17 and a presser roller 18. The drawing roller device 16 has a hydraulic motor 16B driven by a hydraulic pump 16A, and this hydraulic motor 16B drives a pinch roller 17, thereby applying drawing to the cast pipe 14.

The mold device 13, as shown in FIGS. 2 and 3,
A mold 19 made of graphite or ceramics and a core 20 made of graphite or ceramics.
It is composed of.

The mold 19 has a hollow shape and includes a core holding inner diameter part 21 at the end on the molten metal inflow side, and a tube outer surface forming inner diameter part 22 around the mold center axis extending substantially over the entire length excluding the core holding inner diameter part 21.

The core 20 is inserted into the mold 19 and has a flange portion 23 fitted to the core holding inner diameter portion 21 of the mold 19 at the end on the molten metal inflow side, and has a mold center axis extending over substantially the entire length excluding the flange portion 23. A tube inner surface molding outer diameter portion 2 that is provided around the tube outer surface molding inner diameter portion 22 of the mold 19 and forming a tube forming passage 25 therebetween.
4. The core 20 also includes molten metal injection passages 26 that communicate with the tube forming passage 25 at each of a plurality of positions (four positions in this embodiment) around the mold center axis in the flange portion 23 . Each molten metal injection passage 26 has a cross-sectional shape of an arc. In addition,
Joint portion 2 sandwiched between adjacent molten metal injection passages 26
It is preferable to make the thickness g of 7 as small as possible in terms of strength, and to make the passage area of each molten metal injection passage 26 larger.

That is, the mold device 13 fits and fixes the flange portion 23 of the core 20 into the core holding inner diameter portion 21 of the mold 19, and the molten metal injection passage 26 and the tube forming passage 25
and communicate in a straight manner. Reference numeral 28 in FIG. 2 is a fixing pin between the mold 19 and the core 20.

Note that the mold device 13 specifically includes a mold 19
A water-cooled jacket body 30 made of copper is inserted through a graphite or ceramic liner 29 at the end of the molten metal outflow side.
At the same time, insert rings 31 and 32 made of bricks are fitted to the molten metal inflow side end of the mold 19, and an iron plate 33 is fitted between the water cooling jacket body 30 and the insert ring 30. As a result, the mold device 13 uses the water-cooled jacket body 30 as a cooling part for solidifying the molten metal, the insert ring 31 as a non-cooling part, and the insert ring 32 as a cooling part for solidifying the molten metal. It is used as a mounting part.

Further, in the continuous casting apparatus 10 of this embodiment, a hole-shaped recess 20A is provided at the end of the molten metal inflow side of the core 20 so that the molten metal flowing into the mold apparatus 13 is not overcooled, and 13 is made to protrude into the furnace.

Thus, the continuous casting apparatus 10 includes a drawing load measuring device 41 and a control device 42.

The pulling load measuring device 41 is the pulling roller device 1
The operating pressure of the hydraulic pump 16A constituting the casting pipe 6 is detected, and the pulling load of the cast pipe 14 by the drawing roller device 16 is thereby measured.

The control device 42 obtains the measurement result of the pull-out load measuring device 41, and controls the hydraulic pump drive control unit 43 to increase the pull-out speed if the pull-out load is larger than a predetermined reference pull-out load. If the load is smaller than a predetermined standard pulling load, the hydraulic pump drive control section 43 is controlled to reduce the pulling speed. Here, the drawing speed of the cast tube 14 is fed back to the control device 42 via a drawing speed detector 44 connected to the output shaft of the hydraulic motor 16B.

That is, according to the continuous casting apparatus 10,
If the measured pull-out load is larger than the predetermined standard pull-out load, it means that the solidification shrinkage of the cast tube 14 in the mold device 13 is excessive, and the inner surface of the cast tube 14 is too close to the core 20 of the mold device 13. The drawing speed is increased so as to weaken the cooling applied to the cast tube 14 by the mold device 13. In addition, if the measured pull-out load is smaller than the predetermined standard pull-out load, "Mold device 13
The coagulation shrinkage is not sufficient.
The drawing speed is reduced so that the mold device 13 provides more cooling to the cast tube 14. Therefore,...
As a result, the casting tube 14 can be appropriately solidified inside the molding device 13 and can be drawn and cast stably, thereby preventing the casting tube 14 from breaking (breakout) and the core 20 of the molding device 13 from breaking. do not have.

In the continuous casting apparatus 10 of the above embodiment, the intermittent drawing control by the control device 42 causes the drawing roller device 16 to perform the drawing operation of the cast tube 14 at a constant drawing speed for the drawing time (te).
Stopping the drawing during the waiting time (tw) after drawing can be repeated as one cycle. At this time, the control device 42 obtains the measurement result of the above-mentioned drawing load measuring device 41, and controls the casting tube 14 to be pulled out in one of the steady drawing process, high load drawing process, or low overload drawing process. The drawing speed of 14 is controlled.

Each of the above-mentioned drawing processes is as follows.

The steady-state drawing process is a steady state in which the drawing load is approximately equal to a predetermined standard drawing load, and the above-mentioned drawing time te and waiting time tw are set at predetermined teo and
Two.

In the high-load pulling process, the pulling load is greater than the predetermined standard pulling load, and the pulling time is
This is to maintain te at teo and make the above waiting times tw and two shorter.

In the low-load pulling process, the pulling load is lower than the predetermined standard pulling load, and the pulling time is
te is maintained at teo, and the waiting time tw is made longer than two.

That is, in the continuous casting apparatus 10,
When the measured drawing load is larger than the predetermined standard drawing load, the solidification shrinkage of the casting tube 14 in the mold device 13 becomes excessive, and the inner surface of the casting tube 14 is separated from the core 20 of the casting device 13. The waiting time tw is shortened so that the cooling applied to the casting tube 14 by the molding device 13 is weakened.
In addition, when the measured drawing load is smaller than the predetermined reference drawing load, it is determined that the mold device 13 is in a low-load drawing process where solidification and shrinkage is not sufficient, and the mold device 13 applies the load to the cast tube 14. Increase the waiting time tw to strengthen the cooling.
In addition, when the drawing operation of the cast pipe 14 is performed intermittently with one cycle of drawing/stopping as described above, the cooling effect applied by the mold device 13 to the casting pipe 14 is performed at the time of stopping the drawing (i.e., when the drawing is stopped). during the waiting time tw). Therefore,
, it is possible to solidify the casting tube 14 appropriately inside the molding device 13 and perform stable pultrusion casting, thereby preventing breakout of the casting tube 14 and damage to the core 20 of the molding device. do not have.

According to the inventor's experimental results, the continuous casting apparatus 10 described above can produce cast pipes "32A, 65A,
80A, wall thickness 4.2 to 4.5mm], the appropriate standard pull-out load is about 42Kg/ ^cm2 , and if the pull-out load is larger or smaller than this, casting problems will occur as mentioned above. One thing was recognized.

[Effects of the Invention] As described above, according to the present invention, a cast pipe can be appropriately solidified in a mold device and stably drawn and cast.

[Brief explanation of the drawing]

FIG. 1 is a control system diagram showing an embodiment of the present invention;
FIG. 2 is a sectional view showing the mold device, and FIG. 3 is an end view showing the mold device. 10... Continuous casting device, 11... Molten metal holding furnace,
12... Casting port, 13... Mold device, 14... Casting pipe, 16... Drawing roller device, 20... Core, 41... Pulling load measuring device, 42... Control device, 44... Drawing speed detector.

Claims (1)

[Scope of Claims] 1. In a horizontal continuous casting method for metal tubes, in which a molten metal contained in a molten metal holding furnace is solidified into a tubular shape in a molding device to form a cast tube, and the cast tube is pulled out, the drawing load of the cast tube is is measured, and if the pullout load is larger than a predetermined standard pullout load, the pullout speed is increased, and if the pullout load is smaller than the predetermined reference pullout load, the pullout speed is controlled to be decreased. A method for horizontal continuous casting of metal tubes. 2 The molten metal contained in the molten metal holding furnace is solidified into a tubular shape in a mold arrangement to form a cast pipe, and the cast pipe is pulled out at a constant drawing speed during the drawing time, and the drawing is stopped during the waiting time after this drawing. In the horizontal continuous casting method for metal tubes, which is repeated as one cycle, the pull-out load of the cast tube is measured, and in a steady state where the pull-out load is approximately equal to a predetermined standard pull-out load, the above-mentioned pull-out time te and waiting time tw are set in advance. determined teo and
a steady drawing process in which the drawing load is larger than a predetermined standard drawing load; a high-load drawing process in which the drawing time te is maintained at teo when the drawing load is greater than a predetermined standard drawing load; and a high-load drawing process in which the waiting time tw is shorter than two; is smaller than the predetermined standard pull-out load, the above-mentioned pull-out time
A method for horizontal continuous casting of metal tubes, comprising a low-load drawing process in which te is maintained at teo and the waiting time tw is made longer than two. 3. A mold device that is disposed at the pouring port of a molten metal holding furnace and solidifies the molten metal into a tubular shape to form a cast tube, and a drawing roller device that pulls out the cast tube formed by the mold device. In a horizontal continuous casting machine for metal pipes, we obtained the measurement results of a pull-out load measuring device that measures the pull-out load of the cast pipe by a pull-out roller device and a pull-out load measuring device, and confirmed that the pull-out load is greater than the predetermined standard pull-out load. A control device for controlling the drawing so that if the drawing load is smaller than a predetermined reference drawing load, the drawing speed is increased, and if the drawing load is smaller than a predetermined standard drawing load, the drawing speed is reduced. Horizontal continuous casting equipment.