JPH03151116A - Control method of high-speed extrusion of extruded metallic material - Google Patents

Abstract

PURPOSE:To enable extrusion at the maximum speed without generating surface flaw by increasing or decreasing extrusion speed so as to bring a measured temp. close to the maximum set temp. and fixing extrusion speed when the measured temp. is in the set temp. range and is brought closest to the maximum set temp. CONSTITUTION:A temp. comparator 2 with which the surface temp. T of extruded material B just after extrudion is measured and also that measured temp. T is compared with the set temp. range (Tmin - Tmax) and a speed control device 3 with which the extrusion speed V of a extruder A is automatically controlled corresponding to the output of the temp. comparator are equipped on the outlet side of the extruder A. The surface temp. range just after extrusion in which the extruded material can be extruded without generating surface flaw is previously determined and it is taken as the set temp. range (Tmin - Tmax). The extrusion speed V is increased or decreased and, when the measured temp. is in the set temp. range (Tmin - Tmax) and brought closest to the maximum set temp. Tmax, the extrusion speed is made to fix. In this way, the extrusion at maximum speed in the range that surface flaw isn't generated is done and productivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of extruding a metal extruded material, such as aluminum or its alloy, so that the extruded material is extruded at the maximum speed within a range that does not cause surface defects in the extruded material.

Conventional technology Improve productivity when extruding various extruded materials,
Furthermore, in order to reduce costs, it is important to increase the extrusion speed.

However, if the extrusion speed is increased unnecessarily, surface defects will only occur in the extruded material, and it is necessary to set the extrusion speed to the maximum within a range where such defects do not occur. By the way, if the surface temperature of the extruded material becomes too high above a certain point, cracks will occur on the surface of the extruded material, and if it becomes too low, die lines will occur, and if the extrusion speed is increased, the surface temperature of the extruded material will increase. It is empirically known that the surface temperature also increases, and conversely, if the extrusion speed is decreased, the surface temperature also decreases. Therefore, conventionally, based on such empirical rules, the extruded material was extruded at a speed as high as possible within a range that did not cause surface defects.

Problems to be Solved by the Invention However, the extrusion speed setting is based on experience, and extrusion is not always performed at the maximum extrusion speed for the billet, leaving room for productivity improvement. It was something.

The present invention has been made in order to solve the above-mentioned problems, and aims to provide a high-speed extrusion control method for metal extruded materials that always extrudes at the maximum extrusion speed and improves productivity to the utmost. This is the purpose.

As a means to solve the problem, the present invention provides an extruded material immediately after extrusion that can be extruded without causing surface defects such as cracks or die lines on the surface of the extruded material, which has been known only empirically in the past. While quantitatively understanding the surface temperature range of the extruded material, by continuously measuring the surface temperature of the extruded material immediately after extrusion and comparing the measured temperature with the set temperature, it is possible to determine whether the measured temperature is the set maximum temperature. The maximum extrusion speed of the billet is achieved by controlling the extrusion speed so as to be closest to the maximum extrusion speed of the billet.

That is, in this invention, the surface temperature range of the extruded material immediately after extrusion that can be extruded without causing surface defects in the extruded material is determined in advance, this is set as the set temperature range, and when extrusion molding is performed, the surface temperature range of the extruded material immediately after extrusion is determined. Continuously measure the surface temperature of The gist of this is a high-speed extrusion control method for metal extrusions, which is characterized by controlling the extrusion speed to the maximum extrusion speed for the billet by keeping the extrusion speed constant at the point when it approaches the set maximum temperature. be.

In this invention, it is necessary to quantitatively understand in advance the relationship between the surface temperature of the extruded material immediately after extrusion and the surface texture of the extruded material. Specifically, by repeating extrusion tests with various extrusion speeds and billet temperatures set in advance, we determined the lower limit (T■In) and upper limit ( T■aX
) is quantitatively understood, and this is set as a predetermined set temperature range (Tsln - Tsax). By the way, if it is less than the lower limit value (Twin), die lines will occur, and if it exceeds the upper limit value (Tsax) t'', cracks will occur. A temperature sensor is attached to measure the surface temperature of the extruded material. As this sensor, for example, a radiation thermometer that converts the intensity of infrared rays into temperature is suitably used.

Extrusion shall be started after making the above preparations.

The control method of the present invention will be explained below based on the flowchart shown in FIG.

First, it is determined whether the measured temperature (T) of the extruded material immediately after extrusion is within the set temperature range (TIlin - Tmax). The results are: a) if the measured temperature (T) is within the set temperature range (Twin - Tsax); (b) if it is less than the set minimum temperature (Tmln); and c)
This belongs to any of the cases where the set maximum temperature (Tmax) is exceeded, and each case will be explained separately.

b) The measured temperature (T) immediately after the start of extrusion is within the set temperature range (T
m1n - Tmax ) (see the part surrounded by the broken line (A) in Figure 1) If the extrusion speed (V) is not the upper limit (V x ax ), increase the extrusion speed (V). The measured temperature (T) and the set maximum temperature (Tmax) are compared. If the measured temperature (T) has not reached the set maximum temperature (TaX), the extrusion speed (V) is further increased. This is repeated until the measured temperature (T) approaches the set maximum temperature (TxaX), at which point the extrusion speed (V) is kept constant and extrusion is continued. This extrusion speed (V) becomes the maximum extrusion speed. On the other hand, when the extrusion speed (V) reaches a predetermined upper limit value (Vmax) while the extrusion speed is increasing, extrusion is continued at the upper limit value (Va+ax). In this case, this extrusion speed (V) becomes the maximum extrusion speed.

) The measured temperature (T) immediately after the start of extrusion is the set minimum temperature (T
If the extrusion speed (V) is not the upper limit value, the extrusion speed (V
) to increase the measured temperature (T) and the set minimum temperature (T
ffiin). If the measured temperature (T) does not exceed the set minimum temperature (Tmln), the extrusion speed (V) is further increased. This is repeated until the extrusion speed (V) is increased until the measured temperature (T) exceeds the set minimum temperature (Tn+in). If the measured temperature (T) exceeds the set minimum temperature (Tfllin), then
As in the case of , the measured temperature (T) is the set maximum temperature (Tm
ax) or the extrusion speed (V) reaches the upper limit value (VBax), and the extrusion speed (V) is increased to the maximum extrusion speed.

C) The measured temperature (T) immediately after the start of extrusion is the set maximum temperature (T)
o+ax) (see the part surrounded by the broken line (c) in Figure 1) If the extrusion speed (V) is not the lower limit value (Vain), lower the extrusion speed (V) and adjust the measured temperature. (T) and the set minimum temperature (Ti1n) are compared. If the measured temperature (T) is not lower than the set maximum temperature (Tmax), the extrusion speed (V) is further decreased. Repeat this process until the measured temperature (T) reaches the set temperature range (Twin -T).
The extrusion speed (V) is decreased until it is within the maximum set temperature (TaX) and closest to the set maximum temperature (TaX). If the measured temperature (T) is lower than the set maximum temperature (Tmax), as in the case of (a) above, if the measured temperature (T) is lower than the set maximum temperature (Tsax) or the extrusion speed (V) is lower than the upper limit. (V
The extrusion speed (V) is increased until reaching sax) to reach the maximum extrusion speed.

In addition, when the measured temperature (T) immediately after the start of extrusion is outside the set temperature range (Tg + in - Tmax), that is, in the case of (a) and (c), the extrusion speed (V) is increased as described above, Or even if it is lowered, the initial temperature of the billet is inappropriate, or the measured temperature (T) does not fall within the set temperature range (Twin - Ta + ax) due to the limit of the extrusion speed control range. Cases may also occur. In this case, the extrusion speed of the billet is set to the upper limit value (Va+ax) or lower limit value (Vwln) of the extrusion speed.
to complete extrusion. However, it goes without saying that the extruded material thus obtained has surface defects such as cracks and die lines on its surface. Therefore,
If the temperature does not fall within the set temperature range (rIllin - TIIlax) even though the extrusion speed (V) has been increased this time, the billet temperature will be set higher than the current extrusion for the next extrusion. Make it. Conversely, if the temperature does not fall within the set temperature range (Tmin - Tmax) even though the extrusion speed (V) is lowered this time, the billet temperature will be lowered when extruding the next billet than during the current extrusion. Set and extrude.

It is desirable to perform the above speed control completely automatically, but it is also possible to manually control the speed while watching the measured temperature display of the temperature sensor so that the measured temperature falls within the set temperature range. good.

Example Hereinafter, the present invention will be explained based on examples.

The example shows a case where A6063 alloy is automatically controlled to be extruded at the maximum extrusion speed when extruding an extruded material having a U-shaped cross section using a flat die.

As a result of repeating various extrusion tests with billets made of A6063 alloy at different billet temperatures and extrusion speeds, we determined the surface temperature range of the extruded material immediately after extrusion when it can be extruded without causing defects on the surface of the extruded material. This was quantitatively determined in advance. As a result, the surface temperature was 510
If the temperature is less than 540℃, die lines will appear on the surface.
It has been found that when the temperature exceeds 100%, staleness occurs. Based on the results, set the temperature range to 510 (Twin) to 540.
(Tsax) ”C. Also, the temperature of the billet was set at 400℃ (Tbmln) to 550℃ (Tbsax
), extrusion speed 10 m/min (Vmln) ~
Each extrusion was initially set to 100 m/min (Vmax).

On the other hand, as shown in Fig. 2, a radiation thermometer (1) for measuring the surface temperature (T) of the extruded material (B) immediately after extrusion is installed on the exit side of the extruder (A), and A temperature comparison device (2) that compares the temperature (T) with the set temperature range (Tm1n - Taax), and a speed control device that automatically controls the extrusion speed (V) of the extruder (A) according to its output. (3) was equipped.

Then, the extrusion speed (V) is set within the initial setting range (Vwin −
While setting the billet temperature (Tb) to an arbitrary speed (vl) within the initial setting range, Tb
m1n, Tb1, Tb2, T1)3, Tb4
, Tb5ax (however, Tb5In<Tb1<T
b2 < Tb3 <"Tb4< Tbmax ) and extrusion was performed.

a) Billet temperature (Tbt) The measured temperature (T) immediately after the start of extrusion is shown in Figure 3 (
As shown in a), the measured temperature (T) is lower than the set minimum temperature (T
win). Therefore, the extrusion speed (V
) was automatically increased, but the extrusion speed (V) reached the upper limit value (VSaX ) before the measured temperature (T) reached the set maximum temperature (To + aX), so this speed was held constant and extrusion It was done. In this case, the upper limit of the extrusion speed of the extruder was the maximum extrusion speed.

b) In the case of billet temperature (Tb2) As shown in (b) in Figure 3, the measured temperature immediately after the start of extrusion is lower than the set minimum temperature (Tsln).
). Therefore, the extrusion speed (V) was automatically increased so that the measured temperature (T) approached the set maximum temperature (Tmax), but the extrusion speed (V)
) until the measured temperature (T) reaches the set maximum temperature (Tma
X), this speed was held constant from then on and extrusion was carried out. In this case, the extrusion speed determined by the measured temperature was the maximum extrusion speed.

C) In the case of billet temperature (Tba) As shown in (c) in Figure 3, the measured temperature immediately after the start of extrusion is within the set temperature range (Twin - Tba).
max). Therefore, the extrusion speed (V
) was automatically increased, but the measured temperature (T
) reached the set maximum temperature (Tmax), this speed was held constant thereafter for extrusion. In this case, the extrusion speed determined by the measured temperature was the maximum extrusion speed.

d) In the case of billet temperature (Tba) As shown in (d) in Figure 3, the measured temperature immediately after the start of extrusion is the set maximum temperature (Twax).
) exceeded. Therefore, the measured temperature (T) is the set maximum temperature (T
The extrusion speed (V) was automatically lowered to approach the maximum value (Vain), but the measured temperature (T) reached the set maximum temperature (Tmax) before the extrusion speed (V) reached the lower limit value (Vain). Therefore, from then on, this speed was held constant for extrusion. In this case, the extrusion speed determined by the measured temperature was the maximum extrusion speed.

e) In the case of billet temperature (Tb) The measured temperature immediately after the start of extrusion was lower than the set minimum temperature (Tsln), as shown in (e) in FIG. Therefore, the extrusion speed (V) was automatically increased so that the measured temperature (T) approached the set maximum temperature (Tsax), but before the measured temperature (T) entered the set temperature range (T■1n - Tmax). Since the extrusion speed (V) reached the upper limit value (Vg+ax), the upper limit extrusion speed was held constant thereafter for extrusion. In this case, the measured temperature (T) is within the set temperature range (Twin −
T+*ax), an extruded material (B) with defects on the surface was obtained.

Therefore, when extruding the next billet, it is necessary to set the billet temperature higher than the current one.

f) In the case of billet temperature (TbIlax) The measured temperature immediately after the start of extrusion is as shown in (f) in FIG.
The set maximum temperature (Tmax) was exceeded. Therefore, the extrusion speed (V) was automatically lowered so that the measured temperature (T) approached the set maximum temperature (Tmax), but the extrusion stopped before the measured temperature (T) entered the set temperature range (Twin - Tmax). Since the speed (V) has reached the lower limit value (Va+1n),
Thereafter, extrusion was carried out while keeping the lower limit extrusion speed constant.

In this case, Δ or 1 constant temperature (T) is the set temperature range (Tln
-TIIax), an extruded material (B) with defects on the surface was obtained.

Therefore, when extruding the next billet, it is necessary to set the billet temperature lower than the current one.

Effects of the Invention As described above, the present invention is capable of extruding an extruded material at the maximum speed within a range without causing surface defects, rather than based on experience as in the past. The surface temperature range of the extruded material immediately after extrusion is determined in advance, this is set as the temperature range, and when extrusion molding is performed, the surface temperature of the extruded material immediately after extrusion is continuously measured,
the? #1 Compare the constant temperature and the set temperature, increase or decrease the extrusion speed so that the measured temperature approaches the set maximum temperature, and make sure that the measured temperature is within the set temperature range and closest to the set maximum temperature. By keeping the extrusion speed constant at the point in time, the extrusion speed is controlled to the maximum extrusion speed for the billet, so when extruding metal extruded materials, it is necessary to extrude at the maximum speed within a range that does not cause surface defects. Can be done. Therefore, productivity can be greatly improved and manufacturing costs can be reduced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a flowchart of the control system, FIG. 2 is a control block diagram, and FIG. 3 is a graph showing the relationship between billet temperature, #J constant temperature, and extrusion speed. It is. (A)... Extruder, (B)... Extruded material, (T)...
・Measurement temperature, (Twin)... Set minimum temperature, (T+
1aX)...maximum set temperature, (V)...extrusion speed,
(Vln)...minimum extrusion speed, (Vgax)...
Maximum extrusion speed. that's all

Claims (1)

[Claims] A surface temperature range of the extruded material immediately after extrusion that can be extruded without causing surface defects in the extruded material is determined in advance, and this is set as a set temperature range (Tmin to Tmax), and when performing extrusion molding, Continuously measure the surface temperature (T) of the extruded material immediately after extrusion, compare the measured temperature (T) with the set temperature (Tmin - Tmax), and calculate the measured temperature (T).
The extrusion speed is increased or decreased so that T) approaches the set maximum temperature (Tmax), and the measured temperature (T) is within the set temperature range (Tmin to Tmax) and is closest to the set maximum temperature (Tmax). 1. A method for controlling high-speed extrusion of a metal extruded material, the method comprising controlling the extrusion speed to the highest extrusion speed for the billet by keeping the extrusion speed constant at a point when the billet approaches the extrusion speed.