JPH07121409B2 - Method and apparatus for controlling extrusion of extruded profile - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a method for controlling extrusion of an extruded shape and an apparatus therefor, and more specifically, in a step of extruding a shape using an extruder, the surface temperature of the shape immediately after extrusion is measured to obtain a shape. The present invention relates to a method and apparatus for controlling extrusion of an extruded shape material which can improve the quality and productivity of the material.

[Prior art]

Generally, surface defects of extruded profile during extrusion molding of aluminum extruded profile (hereinafter referred to as extruded profile) include peeling (pickup), lines (die line), gloss difference (streak) and cracking (tearing). Etc. These defects are affected by the extrusion rate, billet preheating temperature, and workability. In particular, tearing depends on the temperature at which the profile exits the die hole, and it significantly occurs near the melting point (solidus temperature) of the aluminum alloy. To do. This phenomenon occurs even below the melting point at which the aluminum alloy melts, and particularly in the portion where segregation of elements remains in the material (billet). In a conventional extrusion molding factory, the above-mentioned extrusion defects were visually judged by an operator during extrusion molding, and it was dealt with by lowering the extrusion speed or correcting the die based on the judgment. Frequent defects due to dropping and a decrease in yield were likely to occur. Therefore, as a means for solving the above problem, for example, an infrared thermometer that measures infrared rays (radiant energy) is used to continuously measure the surface temperature of the profile during extrusion, and the measured value and the preset upper limit temperature are measured. And a method and an apparatus for controlling the ram speed of the extruder or the billet preheating temperature according to the size of the above (Japanese Patent Application Laid-Open No. 61-11).
See 9324).

[Problems to be Solved by the Invention]

However, of the infrared thermometers, the monochromatic infrared radiation thermometer is sensitive to disturbances such as lighting and dirt, and requires special measures to measure the true temperature. On the other hand, the multicolor infrared radiation thermometer is an improvement on the above disturbance,
It is composed of two monochromatic thermometers, and the ratio of emissivity in different wavelength bands tends to show a constant value. Therefore, since the two-color type can be measured while suppressing the influence of the emissivity, it is possible to accurately measure a value very close to the actual temperature.
Therefore, if it is determined that the defect generation temperature is 600 ° C. for an aluminum alloy, for example, the defect generation can be sufficiently detected by this multicolor infrared thermometer. However, as described above, it is difficult to detect the surface defect generation temperature which is influenced by the extrusion rate, billet preheating temperature, working degree and the like. Therefore, the conventional method and device can measure the surface temperature of the extruded profile, but detect surface properties (oxidation state, roughness, gloss, etc.) and surface defects (tearing, pickup, die mark, die line, etc.) during extrusion. There is a problem that the quality of the extruded shape cannot be improved and the productivity cannot be improved. This invention has been made in view of the above circumstances, and simultaneously measures the actual temperature of the surface of the extruded profile and the surface defect generation temperature, and controls the ram speed and billet heating temperature of the extruder based on the measured values. Accordingly, the present invention aims to provide an extrusion control method and apparatus for extruded profiles, which can improve the quality and productivity of the profiles.

[Means for Solving the Problems]

In order to achieve the above object, a first method for controlling an extruded profile according to the present invention is a surface defect capable of detecting a surface temperature of a profile immediately after extrusion, a surface substance temperature detecting means and a change in the surface temperature of the profile. Continuous measurement is performed by the temperature detecting means, and at that time, the measured value (Ct) of the surface substance temperature detecting means does not exceed a preset upper limit temperature (Ctmax.), And the surface defect temperature detecting means measures the temperature. Generated surface defect temperature (C
s) and the temperature difference (C ₀ ) between the surface body temperature (Ct) measured by the surface body temperature detection means or the temperature change rate (R) measured by the surface defect temperature detection means is a constant value ( It is characterized in that the ram speed of the extruder and the billet heating temperature are controlled so as to be within C or C '). In the second extruded profile control device of the present invention, the surface substantial temperature detection means for measuring the surface substantial temperature of the profile immediately after extrusion and the surface defect of the profile occur simultaneously with the surface substantial temperature detection means. Temperature detecting means for measuring temperature change, signal judging means for comparing and calculating the signals from the both temperature detecting means and a preset value, and the extruder receiving the signal from the signal judging means. And a heating temperature controller for controlling the heating temperature of the billet in response to a signal from the signal determining means. In the present invention, the surface substance temperature detecting means may be any as long as it can detect the surface substance temperature of the extruded profile, and for example, a multicolor infrared radiation thermometer or an eddy current measuring device can be used. . Further, the surface defect temperature detecting means may be any as long as it detects a temperature change that causes a surface defect of the extruded shape member, for example, a monochromatic infrared radiation thermometer, an image sensor in which a photo sensor is linearly arranged. It is possible to use a sensor device composed of a scanning drive circuit and an image processing circuit, or a photoelectron amplification tube using a laser. In this case, both temperature detecting means simultaneously measure the surface temperature of the profile immediately after extrusion, and the measurement position may be any position immediately after extrusion, but it is preferable that the temperature is within the die of the extruder. It is better that the positions are close to each other. More preferably, the measuring position should extend to the circumferential direction of the extruded profile. The signal judging means compares the measured values from the surface substance temperature detecting means and the surface defect temperature detecting means with preset values (upper limit temperature, upper limit of temperature difference, upper limit of temperature change rate, etc.). So, for example, the central processing unit (CPU)
It is possible to use a microcomputer having

[Operation] With the above configuration, the surface temperature of the extruded profile extruded by the extruder is continuously measured by the surface substance temperature detection means and the surface defect temperature detection means, and the measured value is obtained. Among them, the measured value of the surface substance temperature detecting means is subjected to comparison calculation processing with a preset upper limit temperature, and the temperature difference between the surface substance temperature measured by both temperature detecting means and the surface defect occurrence temperature is preset. The temperature difference upper limit value and the temperature change rate measured by the surface defect temperature detecting means are compared and calculated with the preset temperature change rate upper limit value. Then, the ram speed of the extruder and the heating temperature of the billet are controlled based on the signal subjected to the comparison calculation process. Therefore, it is possible to improve quality and productivity while controlling the surface temperature of the extruded profile.

【Example】

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a schematic configuration diagram of an extrusion control device of the present invention. The extrusion control device of the present invention comprises a surface substance temperature detecting means 3 for measuring the surface substance temperature of an extruded shape material 2 (hereinafter referred to as a shape material) immediately after extrusion which is extruded by an extruder 1, and a surface substance temperature detecting means. At the same time as 3, the surface defect temperature detecting means 4 for measuring the surface defect generating temperature of the profile and both temperature detecting means 3, 4
Signal judging means 5 for comparing and calculating a signal from the controller and a preset setting value, a speed regulator 6 for controlling the ram speed of the extruder 1 by receiving a signal from the signal judging means 5, and a signal judging means 5 And a heating temperature controller 7 that controls the heating temperature of the billet heating device 7a in response to a signal from the main part. The surface substance temperature detecting means 3 is formed by, for example, a multicolor infrared radiation thermometer that detects infrared rays (radiant energy) of a plurality of wavelengths, and the surface defect temperature detecting means 4 is a monochromatic color that detects infrared rays (radiant energy) of a single wavelength. It is formed by an infrared radiation thermometer. That is, as the multicolor infrared radiation thermometer 3, a measuring instrument having the following specifications can be used. Specifications of multicolor infrared thermometer ・ Accuracy: ± 1% (full scale) ・ Temperature measurement range: 400 to 600 ℃ ・ Reproducibility: ± 0.5% ・ Ambient environment temperature: 5 to 45 ℃ ・ Response time: 0.5 to 15 Seconds (adjustable) ・ Linear output: 0 to 10 mVdc, 0 to 100 mVdc, 0 to 1 Vdc, 1 to 5 mA, or 4 to 20 mA ・ Power supply: 100/200 Vac, 50/60 Hz By using the above multicolor infrared thermometer The partial change in the surface temperature of the extruded profile 2 immediately after extrusion can be averaged to measure a temperature very close to the actual temperature. Further, as the monochromatic infrared radiation thermometer 4, a thermo spot sensor having the following specifications can be used. Specifications of monochromatic infrared radiation thermometer ・ Accuracy: Within ± 1% (full scale) ・ Temperature measurement range: 100 to 2000 ℃ ・ Ambient environment temperature: 10 to 42 ℃ (Circuit part) ・ Response time: 0.1 seconds (standard specification)・ Linear output: 0 to 1V, mV / ℃ ・ Linear output: Linear ・ Power supply: Any one of 100Vac, 120Vac, 200Vac, 220Vac, 240Vac specified, 50 / 60Hz Single color infrared thermometer is single It is composed of a wavelength detector, and it is used to measure infrared rays (radiant energy) emitted from the object to be measured, such as a profile.
It does not radiate 100% of the radiant energy, and it changes depending on the type of profile, surface condition, etc. This changing rate (efficiency of radiation or absorption) is defined as emissivity. In the case of aluminum, this emissivity is in a wide range of 0.01 to 0.2, and it is said to be difficult to measure because it is low. Further, this monochromatic infrared radiation thermometer is capable of emissivity correction, and it is possible to detect the actual temperature by setting the emissivity before measurement. By using the monochromatic infrared radiation thermometer, a change in the surface temperature (for example, a change that causes gloss immediately before tearing occurs), which is slightly deviated from the actual temperature of the profile 2, is detected. The temperature (temperature at which surface defects occur) can be measured. As shown in FIG. 2 and FIG. 3, both infrared radiation thermometers 3 and 4 are located on the surface of the profile 2 immediately after being molded by the die 8 of the extruder 1, that is, inside the platen 9. It is arranged so that the surface of the profile 2 can be detected. 2 and 3, reference numeral 10 is a container, reference numeral 11 is a ram for pressing the billet 12 in the container 10, and a reference numeral
Reference numeral 13 is a table, and reference numeral 14 is an optical axis of the multicolor infrared thermometer 3 and the monochromatic infrared thermometer 4. The signal judging means 5 is formed by a microcomputer having a central processing unit (CPU). Next, the extrusion control method of the present invention will be described with reference to the flowchart shown in FIG. First, as shown in step A, the billet heating temperature T ₀ is initialized, the billet 12 is carried into the extruder 1 (step B), and then the first ram speed Rv is set (Rv = V), start extrusion. Then, the multicolor infrared radiation thermometer 3 and the monochromatic infrared radiation thermometer 4 simultaneously measure the surface substance temperature and the surface defect generation temperature of the profile 2 immediately after extrusion (step D, step M). The measurement value Ct measured by the multicolor infrared thermometer 3 is compared with a preset profile upper limit temperature setting value Ctmax. (Step E). Here, the profile upper limit temperature set value Ctmax. Varies depending on the material of the profile 2, but for A2014 alloy, for example, 500 ° C is set as the set value from the graph showing the relationship between the tearing depth and the profile temperature shown in FIG. . In the case of the A5056 alloy, 500 ° C is set as the set value from the graph showing the relationship between the temperature difference between monochromatic / multicolored and the maximum temperature of the polychromatic infrared thermometer 3 shown in Fig. 6. When the measured value Ct is lower than the profile upper limit temperature set value Ctmax. Set in this way, a comprehensive judgment is made (step F). On the other hand, as shown in step M, a monochromatic infrared radiation thermometer 4
As shown in step N, the measured value Cs (surface defect generation temperature) measured with the multicolor infrared thermometer 3 is the difference between the measured value Ct (surface actual temperature), that is, Cs.
-Ct = C ₀ is less than or equal to a preset temperature difference upper limit value C? Is determined (step N), and whether the temperature change rate R is equal to or lower than the temperature change rate upper limit value C '. Is determined (step O). Here, as shown in FIG. 7, the temperature difference C ₀ is the surface substantial temperature (7th
It is the difference between the surface color (shown as multicolor in the figure) and the surface defect generation temperature (shown as single color in FIG. 7), but the effect of the number of billets is that the surface deteriorates with extrusion when the number of billets is about 5 or more. , Here the temperature difference of the 7th billet
Represents C ₀ . Although the temperature difference upper limit value C differs depending on the material of the shape member 2, for example, in the case of the A2014 alloy, 10 ° C. is set as the temperature difference upper limit value from the graph of the surface temperature vs. time shown in FIG. In the case of the A5056 alloy, 5 ° C. is set as the upper limit of the temperature difference from the graph of the relationship between the temperature difference and the time shown in FIG. As can be understood from FIG. 8, the surface temperature of the profile is
During extrusion, the temperature rises to a certain temperature (about 520 ℃ for A2014 alloy) and becomes almost constant. On the other hand, the surface temperature measured by the monochromatic infrared radiation thermometer from a certain point during extrusion (about 15 seconds after the start of extrusion) becomes an abnormal curve or a curve different from the actual temperature curve. This is because the surface of the shape member suddenly became glossy or caused tearing, and the set emissivity of the monochromatic infrared radiation thermometer became inappropriate. The temperature change rate R of the monochromatic infrared radiation thermometer 4 is defined as follows (see FIG. 9). R = (Cs′−Cs) / (s′−s) (° C./sec) where:
If Cs′-Cs = 20 ° C. and s′-s = 0.2 to 1 (sec), the temperature change rate R = 20 to 100 (° C./sec). The temperature change rate upper limit value C ′ is a constant value with respect to the temperature change rate R of the monochromatic infrared radiation thermometer 4. From the graph of the relationship between the temperature change rate upper limit value C ', the profile extrusion standard speed W and the temperature measurement time interval (s'-s) shown in FIG. 10, the temperature change rate upper limit value C'and the temperature measurement time interval (s' -S) can be obtained. Here, for example, the relationship between the aluminum alloy and the standard extrusion speed of the profile is as shown in Table 1 below. As described above, when the temperature difference C ₀ and the temperature difference change rate R are equal to or less than the set value C or C ′, a comprehensive judgment is made (step F). That is, is the measured value Ct greater than or equal to the profile lower limit temperature setting value D? Whether the temperature difference C ₀ between the measured values Ct and Cs of the multicolor infrared thermometer 3 and the monochromatic infrared thermometer 4 is the temperature difference lower limit value E or more? Is determined (step F).
Here, the lower limit temperature setting value D of the profile differs depending on the material of the profile 2. For example, in the case of the A2014 alloy, 400 ° C. is set as the set value from the graph showing the relationship between the tearing depth and the profile temperature shown in FIG. Below this temperature, there are few surface defects, but the mechanical strength (property) decreases. Also, with the A5056 alloy,
As can be seen from the graph showing the relationship between the monochromatic / multicolor temperature difference and the maximum temperature of the multicolor infrared thermometer 3 shown in FIG. 6, the setting value of the lower limit temperature setting value D of the profile does not need to be specified. . Further, the lower limit value F of the temperature difference similarly varies depending on the material of the shape member 2, but here is set to 2 to 5 ° C. Step F
When the comprehensive judgment is made and the conditions are satisfied as shown in, whether the billet extrusion is completed or not? Is determined (step G). Then, as shown in step H, is the last billet of one lot extruded? Is judged, and in the case of the last billet, the extrusion molding is completed. On the other hand, when the measured multicolor temperature Ct is equal to or higher than the profile upper limit temperature set value Ctmax. In step E, the signal is sent to the speed adjuster 6 to change the ram speed Rv _{n + 1} (step I). That is, the ram speed set value Vn of the previous time is changed and controlled to the speed (Rv _{n + 1} ) obtained by multiplying the ram speed coefficient A. Here, the ram speed coefficient A may be a value smaller than 1, but it is preferably determined in consideration of the extrudability and productivity of the profile 2.
For the 000 series and A6000 series, A = 0.95, and for the A2000 series and A5000 series, A = 0.8. Further, the signal is transmitted to the heating temperature controller 7 to control the next billet heating temperature (step J). That is, the next billet heating temperature T _{n + 1} = Tn × B is set by multiplying the previous billet heating temperature Tn by the next billet heating temperature coefficient B. Here, B is the next billet heating coefficient, which may be a value smaller than 1, but is preferably determined in consideration of the extrudability and productivity of the profile.
In the case of the system, A5000 system, B = 0.98, and in the case of A1000 system, A6000 system, B = 0.95. If the temperature difference C ₀ is equal to or higher than the temperature difference upper limit value C in step N, or if the temperature change rate R is equal to or higher than the temperature change rate upper limit value C ′ in step O, the signal is adjusted in the same manner as above. The ram speed and the next billet heating temperature are transmitted to the heater 6 and the heating temperature controller 7 (step I, step J). Further, in step F, when the multicolor temperature measurement value Ct is less than the profile lower limit temperature setting value D or the temperature difference C ₀ is less than the temperature difference lower limit value E, the signal is sent to the speed regulator 6 and the heating temperature regulator 7. After being transmitted, the next billet heating temperature Tn + 1 = Tn ×
B'is controlled and the next ram speed Rv _{n + 1} = Vn ×
A'is controlled (step K, step L). Here, B'is the next billet heating temperature coefficient and may be a value greater than 1, but it is desirably determined in consideration of the extrudability and productivity of the profile 2. In the case of A2000 series and A5000 series, B '= 1.02, A1
For 000 series and A6000 series, B '= 1.05. Also,
A'is the next ram speed coefficient, which may be a value greater than 1,
Desirably, it is similarly determined in consideration of the extrudability and productivity of the profile 2, and in the case of A2000 series and A5000 series, A '= 1.02, A100.
In the case of 0 system and A6000 system, A '= 1.1. In the above embodiments, the case where the surface substance temperature detecting means of the profile 2 is the multicolor infrared radiation thermometer 3 has been described, but an eddy current measuring instrument should be used instead of the multicolor infrared radiation thermometer 3. You can also Further, in the above embodiment, the case where the monochromatic infrared radiation thermometer 4 is used as the surface defect temperature detecting means has been described, but the surface defect temperature detecting means does not necessarily have to be the monochromatic infrared radiation thermometer 4. A sensor device composed of an image sensor, a scan drive circuit, and an image processing circuit arranged in a straight line, or
A photoelectron amplification tube using a laser or the like can be used.

【The invention's effect】

As described above, since the present invention is configured as described above, the following effects can be obtained. 1) The surface temperature of the extruded profile is measured immediately after extrusion and the surface defect generation temperature is measured, and the ram speed and the billet heating temperature are controlled based on the measured values, so that the surface temperature of the profile can be controlled. Quality (shape, surface defects, texture, etc.) can be improved. 2) Since the ram speed can be increased as much as possible within the range where surface defects do not occur, productivity is improved. 3) Prevent the occurrence of defects due to oversight of surface defects on the profile,
The yield can be improved.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an extruded profile control device of the present invention,
FIG. 2 is a schematic configuration diagram showing an arrangement state of the surface substance temperature detecting means and the surface defect temperature detecting means in the present invention.
Fig. 4 is a side view of Fig. 2, Fig. 4 is a flowchart for explaining the control method of the present invention, Fig. 5 is a graph showing the relationship between tearing depth and profile temperature, and Fig. 6 is temperature difference and multicolor infrared radiation. Fig. 7 is a graph showing the relationship between the maximum temperature of the thermometer, Fig. 7 is a graph showing the relationship between the surface temperature of the profile and time, Fig. 8 is a graph showing the relationship between the surface temperature of another profile and time, and Fig. 9 Is an enlarged graph showing a part of the relationship between the surface temperature of the profile and the time measured by the monochromatic infrared thermometer shown in Fig. 8. Fig. 10 is the relationship between the rate of temperature change, the standard extrusion speed of the profile and the temperature measurement time interval. It is a graph which shows. Explanation of code (1) …… Extruder (2) …… Extruded profile (3) …… Surface substance temperature detection means (multicolor infrared radiation thermometer) (4) …… Surface defect temperature detection means (single color infrared radiation temperature) (5) …… Signal judging means (6) …… Speed adjuster (7) …… Heating temperature adjuster

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-49-123960 (JP, A) JP-A-58-32518 (JP, A) JP-A-61-119324 (JP, A)

Claims (2)

[Claims] 1. The surface temperature of a profile immediately after extrusion is continuously measured by a surface temperature detecting means and a surface defect temperature detecting means capable of detecting a change in the surface temperature of the profile, at which time the surface temperature is detected. The measured value (Ct) of the means is the preset upper limit temperature (Ct
max.) and the temperature difference between the surface defect generation temperature (Cs) measured by the surface defect temperature detecting means and the surface body temperature (Ct) measured by the surface body temperature detecting means. (C ₀ ) or the ram speed of the extruder and the billet heating temperature are controlled so that the temperature change rate (R) measured by the surface defect temperature detecting means is within a constant value (C or C ′). A method for controlling extrusion of an extruded profile, characterized in that. 2. A surface substance temperature detecting means for measuring a surface substance temperature of a shaped material immediately after extrusion, and a surface defect temperature detecting means for measuring a temperature change causing a surface defect of the shape material at the same time as the surface substance temperature detecting means. A signal judging means for comparing and calculating a signal from both the temperature detecting means and a preset value, and a speed adjuster for controlling the ram speed of the extruder by receiving the signal from the signal judging means. An extrusion control device for extruded profile, comprising: a heating temperature controller for controlling the heating temperature of the billet in response to a signal from the signal determining means.