JP2003220409A - Isothermal extrusion molding system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an isothermal extrusion molding system by which the temperature of extruded products can be controlled to be constant even if there is uneven heating in the longitudinal direction of billet temperature when a billet of such as aluminum material or the like is extruded by a dice. <P>SOLUTION: A temperature dropping part A can be produced in the measured temperature distribution Tb1 for the longitudinal direction of the billet when the billet is heated at the pre-determined billet temperature Tb0. When the billet is extruded isothermally according to a ram speed profile Vr0, the temperature of a extruded product does not become Tp0, a pre-determined isothermal extruding temperature, but becomes Tp1, a measured extruding temperature having a extruding temperature dropping part B. A corrective value S corresponding to the variation is added to a ram speed in a ram position corresponding to the temperature dropping part A in the temperature distribution for the longitudinal direction of the billet, and the isothermal extrusion molding is performed according to a corrective ram speed profile Vr1 that is corrected to elevate a ram speed in correspondence with the said part. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an isothermal control in which a temperature of an extruded product is controlled to be constant when a metal material which is easily processed, particularly a billet made of aluminum or its alloy is extruded by a die to be molded. The present invention relates to an extrusion molding system, and more particularly to an isothermal extrusion molding system that can control the temperature of an extruded product to be constant even when there is uneven heating in the longitudinal direction of the billet temperature.

[0002]

2. Description of the Related Art In recent years, aluminum or its alloys (hereinafter simply referred to as "aluminum") have been used in, for example, lightweight structural materials for structures, cooling fins for semiconductor products, sashes for window frames, etc. Material is used).

There are various methods for producing these products, but many products are continuously pressure-extruded using a die having slits corresponding to a predetermined cross-sectional shape of the product. The long shaped extruded shape member is cut into a predetermined length to be an individual product.

Therefore, FIG. 4 shows an outline of the system configuration of an aluminum material extrusion molding system using a commonly used die.

The aluminum material to be extruded is formed as a cylindrical billet having a predetermined size corresponding to the product to be manufactured, and the billet B1 is inserted into the billet storage portion provided in the container 1. To be done.

A die 2 having a sectional shape of the product is arranged at one end of the container 1, and a stem 3 for pressing the billet B1 is inserted from the other end. Usually, a dummy block is attached to the tip of the stem 3. Here, this block is also referred to as a stem.

The stem 3 is connected to a hydraulic cylinder 4 which is operated by oil discharged from a hydraulic pump 5 in order to press the billet B1. When the ram position of the hydraulic cylinder 4 moves by hydraulic pressure, the stem 3 also moves and presses the billet B1. Then, the billet B1 is pressurized in the container 1 by the stem 3, and the aluminum material thereof becomes the extruded profile W of the cross-sectional shape of the product from the die 2.
It is extruded continuously.

Further, the hydraulic cylinder 4 of the extrusion molding system.
A billet heating device 6 for heating the billet to a temperature suitable for extrusion is installed at a position side by side. The billet heating device 6 can heat the billet to a constant temperature in the longitudinal direction or a temperature having a taper, and while the billet B1 inserted into the billet storage portion of the container 1 is extruded. The billet B2 to be continuously extruded is heated to a predetermined billet temperature. After the billet B1 is extruded, the heated billet B2 is carried into the container 1 by the carrying device 7 and loaded.

It should be noted that the heating time of one billet is set in time for the next extrusion cycle, as shown in FIG.
It is heat-treated during extrusion and conveyed to the container 1 of the extrusion press. Then, in the billet heating device 6, the billet to be subsequently extrusion-molded is heated to enable continuous extrusion.

As the extruded profile W is a long one, which is continuously extruded, a puller device for pulling it with a constant pulling force is not shown in FIG. 4 so as not to cause bending. The extruded profile W is gripped at its end and travels at the extrusion speed of the extruded profile W.

A ram position / speed detector 8 for detecting the movement of the stem 3, that is, the ram position or speed is provided in order to control and quality control the extruded profile W.
A temperature detector 9 for measuring the extrusion temperature of the profile W is arranged near the die 2. Further, a billet temperature detector 10 for detecting the temperature of the billet is arranged near the billet outlet of the billet heating device 6.

The ram pressure applied to the billet B1 by the stem 3 is a function of the ram speed, and this ram speed is also a function of the oil discharge amount of the hydraulic pump 5. In order to realize the ram speed profile aiming at the isothermal extrusion, the discharge amount of the hydraulic pump 5 is controlled. In the extrusion molding system shown in FIG. 4, FIG. 5 shows a block configuration of a discharge rate control system that controls a hydraulic pump according to a set extrusion ram speed so that an extrusion product can be extruded at an isothermal temperature.

In the discharge rate control system having this control block configuration, input can be arbitrarily set so as to perform isothermal extrusion in which the extrusion temperature of the product is constant, and conditions for the input setting include the length of the initial velocity section and the ram speed. It is also possible to set a fixed ram speed profile for the ram speed in the fast extrusion section, and the end section length and the end ram speed. It is also possible to input and set the magnitude of speed to change to various ram speed profiles.

In the discharge rate control system of the hydraulic pump in the extrusion molding system of FIG. 5, when the extrusion molding start instruction button provided on the operation unit 14 is pressed, the extrusion press control unit 11 causes the ram position / speed detector to operate. According to the ram position detected by 8, the ram speed is sequentially read from the ram speed profile stored inside. The isothermal extrusion control unit 12 mainly controls the ram speed aiming at the isothermal extrusion of the product, calculates the discharge amount corresponding to the speed, and causes the pump drive control unit 13 to discharge the hydraulic pump 5. Send a command. The pump drive control unit 13 supplies the hydraulic pump 5 with drive power in accordance with the command value in accordance with the discharge amount command. The hydraulic pump 5 outputs the oil discharge amount corresponding to this command value and drives the hydraulic cylinder 4. In this way, the hydraulic cylinder 4 applies the extrusion pressure to the aluminum material of the billet B1 according to the set ram speed profile of the stem 3.

Here, the ram speed profile stored in the extrusion press control unit 11 is input and set by the operator using the touch panel 15 provided in the operation unit 14 based on the trial result of extrusion and the collected data by experience. The temperature of the product extruded from the die is detected by the product temperature detector 9, and when the temperature is lower than the preset temperature, the ram speed is increased, and when it is high, the ram speed is increased. May control to decrease the ram speed.
The ram speed profile can be modified in various other ways according to the type of die and extrusion molding, and numerical values for various conditions may be entered by using the provided numeric keypad or the like. It is also possible to prepare a plurality of numerical values for each condition in advance and input them by selecting from them. Therefore, the discharge rate control system of FIG. 5 is provided with the storage unit 16 and the set ram speed profile input from the operation unit 16 during extrusion molding can be stored in the storage unit 16, or a plurality of basic ram speed profiles can be stored. A ram speed profile having a pattern is stored in advance in the storage unit 16
It can also be stored in.

In the discharge rate control system of FIG. 5, the extrusion press control section 11 controls the discharge rate of the hydraulic pump 5 according to the ram speed profile stored in the storage section 16, or by the product temperature detection data. It is intended to realize the isothermal extrusion of the product by changing the ram speed up and down as described above.

The billet temperature detector 10 arranged near the billet outlet of the billet heating device 6
The surface temperature of the billet B2 that has been heated and carried out is detected. The detected billet temperature is displayed on the touch panel 15, and the temperature is monitored for abnormal heating of the billet. The billet temperature is also used as reference information when setting the ram speed profile during extrusion molding.

[0018]

By the way, in the discharge rate control system in the extrusion molding system shown in FIG. 5, the ram of the ram speed profile set according to the ram position detected by the ram position / speed detector 8 is used. Driving the stem 3 at a speed. Therefore, the extrusion temperature of the product is controlled only by adjusting the ram speed. However, the extrusion temperature of the product is not determined only by the magnitude of the ram speed, but changes depending on the type of die, the heating temperature of the billet, etc. in addition to the ram speed.

Now, paying attention to the billet temperature, the relationship between the temperature in the longitudinal direction of the billet to be extruded and the temperature of the profile W extruded as a product will be described with reference to FIG. The graph of FIG. 6A shows the temperature Tb of the billet surface with respect to the length L of the billet in the axial direction (longitudinal direction).
The graph of (b) shows the profile of the ram speed Vr when the billet is extruded, and the graph of (c) shows the profile of (b) for the billet.
The state of the temperature Tp of the extruded profile W when extruded with the ram speed profile shown in FIG. The horizontal axis of each graph is displayed corresponding to the billet length L.

The billet is heated to a preset billet temperature Tb0 by the billet heating device 6 by induction heating. FIG. 6A shows an example of taper heating that changes linearly from the billet end to the other end. In the figure, the measured billet temperature Tb1 is shown by a broken line. With respect to the billet that has been thus taper-heated, the ram speed Vr0 obtained as a result of trial and error depending on the type of die, or the like, so that the extrusion temperature Tp of the extrusion profile W can be isothermally extruded over the entire product, or The ram speed profile of the ram speed Vr0 stored in advance is selected, and the extrusion molding is performed according to the selected ram speed profile. The temperature Tp of the extruded profile W formed by extrusion is detected by the product temperature detector 9,
As shown in (c), the billet having the billet temperature Tb0 is extruded according to the ram velocity profile, and as a result, the temperature Tp of the extruded profile W becomes substantially equal over the billet length L. As a ram velocity profile for isothermal extrusion with respect to a taper-heated billet having a temperature gradient as shown in FIG.
As shown in, a flat billet is assumed over the entire billet length.

By the way, as shown in FIG. 6A, in the billet heating device 6, the set billet temperature Tb0.
Even if the billet is taper heated so that
It is deviated from the set temperature like the billet measured temperature Tb1. If this deviation is small, the result shown in FIG.
As shown in (c), the variation is absorbed and almost isothermal extrusion molding can be realized.

However, as shown in FIG.
As shown in the portion A, the actually heated billet actual temperature Tb1 with respect to the set billet temperature Tb0 may deviate greatly from the billet temperature Tb0, and heating may be partially insufficient. . Therefore, the ram speed profile is set on the assumption of the isothermal extrusion shown in FIG. 6C, and thus the billet having the portion A lower than the temperature Tb0 due to insufficient heating is shown in FIG. 6B. When extrusion molding is performed with a ram velocity profile, as shown in FIG.
As shown in the measured temperature Tp1, a portion B where p is lower than the set extrusion temperature Tp0 appears.

As described above, the portion B lower than the set extrusion temperature Tp0 has a great influence on the quality of the extruded profile as a product, and for example, the unevenness of the structure occurs and the color is generated in the final surface treatment (eg, alumite treatment). There is unevenness. Therefore, the occurrence of this temperature-reduced portion is a problem.

As shown in FIG. 7 (a), when there is only one temperature drop portion, for example, one billet is formed by adding a part of the next billet to the billet remaining in the previous extrusion molding. It occurs when the billet formed with is heated. It is considered that this is because the magnetic flux is disturbed in the additional part of the billet, the induction heating becomes insufficient at that part, and the temperature distribution does not become a straight line.

In this case, there is a problem on the billet side and the billet temperature becomes non-uniform, but it may be affected by the heating characteristics of the billet heating device. The billet heating device, which heats the billet by induction heating, usually includes three induction coils to which three-phase power is supplied. Two billets are inserted side by side in the longitudinal direction in the induction coils arranged side by side, and induction heating is performed in a batch system. Then, the next billet is inserted, the billet on the outlet side is taken out, and the billet on the inlet side is induction-heated twice. By this procedure, billet taper heating is performed.

However, when the billets are sequentially heated according to this procedure, depending on the arrangement interval of the three induction coils of the billet heating device, as shown in FIG. 8A, at the billet actual measurement temperature Tb1, the set billet temperature Tb is obtained.
The portions A1 and A2 lower than 0 may occur. Such temperature decreasing portions A1 and A2 are billet measured temperatures Tb.
If it exists in No. 1, as in the case of FIG. 7, a set extrusion temperature Tp0 that is isothermal at the time of extrusion molding should be obtained, but portions B1 and B2 in which the extrusion temperature is reduced corresponding to the temperature reduced portions A1 and A2 are generated. Will end up. Even in this case, as in the case of FIG. 7, the influence on the product quality becomes a problem.

Therefore, according to the present invention, the billet heating temperature is not set to a set value but extruded before the extrusion molding, by devising the billet forming process or devising the heating procedure or heating means in the billet heating device. In addition, by detecting the temperature distribution in the billet longitudinal direction and correcting the ram speed profile in accordance with the detected lowered part of the billet temperature,
An object of the present invention is to provide an isothermal extrusion molding system that realizes isothermal extrusion molding of a billet such as an aluminum material.

[0028]

In order to solve the above problems, the present invention provides an isothermal extrusion molding system for isolating a billet of an aluminum material or the like with a die according to the billet extrusion conditions. Based on the billet extrusion conditions for the billet, the billet extrusion control means for controlling the billet extrusion according to the billet extrusion conditions, the control means refers to the longitudinal temperature distribution of the billet, the billet extrusion The conditions were corrected, and the temperature distribution in the longitudinal direction of the billet was detected after the billet was heat-treated and before extrusion molding of the billet.

The billet extrusion conditions include a ram velocity profile with respect to a ram position, and when the control means detects a deviation from a specified value in the temperature distribution in the longitudinal direction of the billet, the ram velocity profile. With respect to the ram position, the ram speed related to the ram position corresponding to the shift position is corrected according to the amount of change in the shift.

Further, when there is the amount of change below the specified value in the temperature distribution in the longitudinal direction of the billet, the control means determines the ram speed related to the ram position corresponding to the shift position according to the amount of change. For the specified value, a distribution average value of the longitudinal temperature distribution of the billet is used, or the average value of each of a plurality of ranges in the longitudinal temperature distribution of the billet is averaged. We decided to use the distribution value.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of an isothermal extrusion molding system according to the present invention will be described with reference to the drawings.

In the discharge amount control in the isothermal extrusion molding system shown in FIG. 5, the ram speed with respect to the ram position is controlled so that the billet of aluminum or the like is extruded isothermally. The discharge amount control system is provided with a product temperature detector 9, a billet temperature detector 10, and a product speed detector for detecting the puller speed of the profile W, but the detection information by these is simply It was used to confirm product quality, etc., and was only reference information for the operator to correct the extrusion conditions when the next billet was extrusion-molded. Therefore, as mentioned above, if there is a temperature non-uniform portion in the billet longitudinal direction,
It was not possible to realize isothermal extrusion of the extruded shape.

Therefore, in the isothermal extrusion molding system according to the present embodiment, the temperature in the billet longitudinal direction is detected before the extrusion molding, and the ram speed profile is corrected in accordance with the detected lowered portion of the billet temperature. It is designed to realize isothermal extrusion molding of billets such as aluminum materials. The method will be described with reference to FIG. Figure 1
6 shows a graph corresponding to FIG. 6, and in FIG. 1A, regarding the billet that is taper-heated by the billet heating device 6, the billet measured temperature that can be detected in the billet longitudinal direction before extrusion molding the billet. In Tb1, the case where the temperature decreasing portion A exists is shown.

As shown in FIG. 7, when there is a temperature decreasing portion A in the longitudinal direction of the billet, when the billet is extruded at the ram speed Vr0 where the isothermal extrusion is planned, the isothermal temperature of the extruded profile W is increased. Tp0 cannot be maintained over the entire billet longitudinal direction. As shown in FIG. 1C, at the billet measured temperature Tp1, the extrusion temperature lowered portion B is generated at the billet measured temperature Tp1 corresponding to the temperature lowered portion A.

Therefore, in the isothermal extrusion molding system of this embodiment, paying attention to the fact that when the ram speed Vr is increased during extrusion, the extrusion temperature Tp of the profile is also increased, and the extrusion temperature is lowered to the measured billet temperature Tp1. When the portion B occurs, the ram speed profile set during the extrusion molding of the billet is corrected so that the ram speed during the billet extrusion molding of the portion can be increased.

FIG. 1B shows a state in which the ram velocity profile is corrected corresponding to the temperature decreasing portion A of the billet. In the same (b), the correction value S is added to the ram speed Vr0 corresponding to the temperature decreasing portion A in the billet longitudinal direction to create the corrected ram speed profile Vr1. With this correction value S, the extrusion temperature lowering portion B can be corrected to an isothermal setting extrusion temperature Tp0.

Here, in order to obtain the correction value S of the ram speed, the set billet temperature Tb0 is compared with the billet actual measurement temperature Tb1 in the billet longitudinal direction, and calculation is performed based on the amount of change. At this time, the change coefficient k of the extrusion temperature with respect to the change amount of the billet temperature is obtained in advance. This coefficient of change k has different values depending on the type of die used and the extrusion conditions, so it is acquired according to various cases. The arithmetic expression of this correction value S is expressed as follows.

S = k × (Tb0-Tb1) In this way, before extrusion molding of the billet, the temperature in the longitudinal direction of the billet heated by the billet heating device is detected, and the change amount is equal to the isothermal extrusion temperature Tp0. When the allowable range is exceeded, the correction value S of the ram speed is calculated according to the above-mentioned arithmetic expression. Then, the change amount is the isothermal extrusion temperature Tp0.
Position L in the longitudinal direction of the billet temperature exceeding the allowable range
The calculated correction value S is added to the ram speed Vr corresponding to the above to obtain the corrected ram speed Vr1.

Here, based on this corrected ram speed Vr1, as shown in FIG. 1 (c), a corrected ram speed profile in which the ram speed for the temperature decreasing portion A in the longitudinal direction of the billet is corrected is created. If the billet is extruded based on this corrected ram speed profile, the ram speed is adjusted and the billet is adjusted even if the temperature distribution in the longitudinal direction of the billet is uneven and there is a temperature drop. Extrusion temperature T that is isothermal over the entire length of
p0 can be maintained.

Next, FIG. 2 shows a block configuration of a discharge rate control system to which the isothermal extrusion molding system according to the present embodiment based on the corrected ram speed profile shown in FIG. 1 is applied. The ram speed control by this discharge amount control system is basically the same as the discharge amount control system shown in FIG. 5, and the extrusion press control unit 11, the isothermal extrusion control unit 12, and the pump drive control unit 13 are controlled. By adjusting the discharge amount of the hydraulic pump 5. When the discharge amount is adjusted, the stem 3 connected to the hydraulic pump 5 is driven and the ram speed according to the ram position detected by the ram position / speed detector 8 is output. The product temperature detector 9 detects the extrusion temperature Tp1.

However, in the discharge amount control system according to the present embodiment, the billet longitudinal direction temperature detector 17 for detecting the surface temperature in the longitudinal direction of the billet is arranged on the billet outlet side of the billet heating device 6. The discharge amount control system shown in FIG. 5 is provided with the billet temperature detector 10. However, in the discharge amount control system according to the present embodiment,
The difference is that the billet longitudinal direction temperature detector 17 is replaced.

The operation of the discharge rate control system according to the present embodiment shown in FIG. 2 will be described. First, while the billet B1 is being extruded, the billet longitudinal direction temperature sensor 17 is extruded. For the billet B2, the temperature Tb1 in the longitudinal direction of the billet B2, which is tapered by the billet heating device 6, is detected and transmitted to the isothermal extrusion control unit 12.

On the other hand, assuming that the billets B1 and B2 are extrusion-molded using the same die, the extrusion conditions for the dies of these billets are inputted and set by the operator in advance from the operation section 14. Has been done. The extrusion conditions include a ram velocity profile. This set ram speed profile is shown in Fig. 1.
As shown in (b), it is based on the ram speed Vr0 corresponding to the set billet temperature Tb0 taper-heated by the billet heating device 6.

However, as shown in FIG. 1A, the temperature Tb1 in the longitudinal direction of the billet heated by the billet heating device 6 may be different for each billet, and the temperature Tb1 in the longitudinal direction may be different. It may include a large temperature drop portion A. Therefore, the extrusion press control unit 11 compares the longitudinal temperature Tb1 input to the isothermal extrusion control unit 12 with the set billet temperature Tb0 before the extrusion molding of the billet B2 is started. Then, the correction value S for the ram speed is obtained according to the above-mentioned arithmetic expression. further,
When the correction value S is larger than the specified value in the billet longitudinal direction, the ram speed V with respect to the ram position
The correction value S is added to r0.

In this way, the corrected ram speed profile shown by the solid line in FIG. 1B is created and set. When the billet B2 is loaded into the container 1,
The extrusion press control unit 11 determines the ram speed corresponding to the ram position to the isothermal extrusion control unit 12 according to the corrected ram speed profile set according to the ram position information from the ram position / speed detector 8. Order. for that reason,
As the hydraulic pump 5 is driven in accordance with the corrected ram speed profile and the extrusion molding of the billet B2 proceeds, the corrected ram speed corresponding to the ram position is output even in the temperature decreasing portion A, and isothermal extrusion can be realized for the entire billet.

In the above, the temperature decrease portion A is determined based on the difference value between the set billet temperature Tp0 and the billet measured temperature Tp1. However, the temperature decrease portion A is determined by the averaging process of the billet measured temperature Tp1. The determination of A can also be performed. According to the average straight line value obtained by averaging the measured billet temperature Tb1 along the gradient of the set billet temperature Tp0, the measured billet temperature Tb1 is compared with this average straight line value, and the difference value deviates from the specified value or more. You may make it detect as a temperature fall part.

However, the temperature change at both ends of the heated billet is large, and it is difficult to perform the averaging process from one place to another. Moreover, the amount of calculation becomes large in order to calculate along the gradient of the set billet temperature Tp0. Therefore, it is efficient to perform the averaging process as shown in FIG. In the figure, the change of the billet temperature Tb with respect to the billet length L is shown, the set billet temperature Tb0 is a broken line, and
The actual billet temperature Tb1 is shown by a solid line. The billet measured temperature Tb1 has a temperature decreasing portion A.

Here, at the leading end and the rear end of the billet in the longitudinal direction, the ranges a and b which are considered to well indicate the actual measured temperature Tb1 of the billet are determined, and the billet measured in each of the ranges a and b. The average value of the temperature Tb1 is calculated. Then, a straight line is obtained from these two average values, and this straight line is used as the average value of the billet actual measurement temperature. Billet measured temperature Tb1
The position in the longitudinal direction deviating from the straight line by the specified value or more can be determined as the abnormal temperature portion. Further, the range of the averaging process is not limited to two places, and the abnormal temperature portion can be easily determined even if the broken line is obtained with a plurality of places. The method for obtaining the corrected ram speed profile after the abnormal temperature portion is determined is the same as in the above case.

The measured temperature of the billet in the longitudinal direction of the billet is input to the isothermal extrusion control unit for each billet to be extruded, and when the billet is extruded, the temperature drop portion is detected and the corrected ram speed is calculated. However, since the change coefficient k is obtained empirically for each die, it is possible to prepare a table of correction values according to the change amount of the temperature lowered portion. If there is a tendency for the location where the temperature drop occurs, the correction ram speed profile corresponding to the amount of change is stored and the correction ram speed profile is selected and set according to the change of the temperature drop. Good.

[0050]

As described above, according to the isothermal extrusion molding system of the present invention, the temperature in the longitudinal direction of the billet can be detected before the extrusion molding of the billet, and the temperature lowered portion can be detected. When extruding, the set ram speed profile can be corrected to the corrected ram speed profile corresponding to the temperature drop portion. It is not necessary to devise processing or to change the heating procedure or heating means in the billet heating device, and easily change the ram speed profile of the ram speed correction for the temperature decrease part to isothermal extrusion molding of billets such as aluminum materials. It can be realized and maintain stable product quality.

[Brief description of drawings]

FIG. 1 shows an isothermal extrusion molding system according to the present embodiment.
It is a figure explaining the temperature change of a billet longitudinal direction, a ram speed pattern with respect to a ram position, and extrusion temperature.

FIG. 2 is a diagram showing a control block configuration of the isothermal extrusion molding system according to the present embodiment.

FIG. 3 is a diagram illustrating another method of obtaining a difference value between a set value of the billet longitudinal direction temperature and an actually measured value.

FIG. 4 is a diagram showing a schematic cross section of a conventional extrusion molding apparatus used for extrusion molding of a billet such as an aluminum material.

FIG. 5 is a diagram showing a control block configuration of an isothermal extrusion molding system according to a conventional technique.

FIG. 6 is a diagram illustrating a temperature change in a billet longitudinal direction, a ram speed pattern with respect to a ram position, and an extrusion temperature in a conventional isothermal extrusion molding system.

FIG. 7 is a diagram illustrating an example of a relationship between a billet longitudinal direction temperature and a product extrusion temperature.

FIG. 8 is a diagram illustrating another example of the relationship between the billet longitudinal direction temperature and the product extrusion temperature.

[Explanation of symbols]

1 ... Container 2 ... Dice 3 ... Stem 4 ... Hydraulic cylinder 5 ... Hydraulic pump 6 ... Billet heating device 7 ... Billet conveyor 8 ... Ram position / speed detector 9 ... Product temperature detector 10 ... Billet temperature detector 11 ... Extrusion press control unit 12 ... Isothermal extrusion controller 13 ... Hydraulic pump drive controller 14 ... Operation unit 15 ... Touch panel 16 ... Storage unit 17 ... Billet longitudinal direction temperature detector B1, B2 ... Billets W ... Extruded profile

Claims (6)

[Claims] 1. An isothermal extrusion molding system for isolating a billet according to billet extrusion conditions, wherein the billet extrusion condition for the billet is set based on billet extrusion information, and the billet is extrusion controlled by the billet extrusion condition. The isothermal extrusion molding system is characterized in that the control means corrects the billet extrusion conditions with reference to the temperature distribution in the longitudinal direction of the billet. 2. The isothermal extrusion molding system according to claim 1, wherein the temperature distribution in the longitudinal direction of the billet is detected after the billet has been heat-treated and before the extrusion molding of the billet. . 3. The billet extrusion condition includes a ram velocity profile with respect to a ram position, and when the control means detects a deviation from a specified value in a temperature distribution in the longitudinal direction of the billet, the ram velocity profile with respect to the ram velocity profile is detected. The isothermal extrusion molding system according to claim 1, wherein the ram speed associated with the ram position corresponding to the offset position is corrected according to the amount of change in the offset. 4. The ram speed relating to the ram position corresponding to the shift position according to the variation when the variation in the temperature distribution in the longitudinal direction of the billet is equal to or less than the specified value. 4. The isothermal extrusion molding system according to claim 3, wherein the correction is performed so as to increase. 5. The isothermal extrusion molding system according to claim 3, wherein the control unit detects the deviation with the distribution average value of the temperature distribution in the longitudinal direction of the billet as the specified value. 6. The control means detects the deviation using a distribution value obtained by averaging average values of a plurality of ranges in a longitudinal temperature distribution of the billet as the prescribed value. Or the isothermal extrusion molding system according to item 4.