JPH03128116A - Automatic extrusion molding system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an automatic extrusion molding system, particularly an automatic extrusion system that automatically controls the extrusion speed to an optimum state by detecting the temperature of the shape extruded from a die. It concerns a molding system.

(Prior Art) In extrusion molding systems, it is necessary to accurately control the temperature during molding when a molding material such as an aluminum alloy passes through a die. For example, if the temperature of the molding material becomes too high, the surface of the shaped material extruded from the die will melt, resulting in surface defects in the product. On the other hand, if the temperature is too low, there will be no hardening effect and sufficient mechanical strength will not be obtained. Therefore, in current extrusion molding systems, the billet temperature and extrusion speed are appropriately set based on the molding material used, the extrusion ratio of the product to be manufactured, the die shape, etc. For example, when trying to manufacture a product with a high extrusion ratio, the billet temperature is set low,
On the other hand, when attempting to manufacture a product with a low extrusion ratio, the billet temperature is set high. In reality, these conditions are set manually based on past results.

(Problem to be solved by the invention) In the current extrusion molding system, the conditions are set manually based on the operator's experience, so there is a limit to maintaining the quality of the extruded shape and there is a problem with the yield. Not only that, but there were also limits to production efficiency. Especially the die shape,
Because the processing heat generated by the die varies depending on the extrusion ratio, it is difficult to set appropriate manufacturing conditions. For example, if the conditions are set incorrectly, the temperature of the molding material will rise too much, resulting in defects on the surface of the shaped material. occurs, resulting in a significant decrease in yield.

Furthermore, in order to prevent the occurrence of defective products due to surface defects, the extrusion speed is set to be low, resulting in a decrease in production efficiency.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an automatic extrusion molding system which eliminates the above-mentioned drawbacks, automatically extrudes at an optimum extrusion speed, and further increases product quality and production efficiency.

(Means for Solving the Problems) The automatic extrusion molding system according to the present invention includes a means for detecting the maximum temperature in the width direction of the shape immediately after being extruded from the die, and a means for detecting the maximum temperature in the width direction of the shape immediately after being extruded from the die, and comparing the detected maximum temperature and the optimum extrusion temperature of the molding material. and a means for controlling the extrusion speed of the extruder based on the determined temperature difference, so that the temperature of the molding material during extrusion molding is always maintained at a constant temperature. This is a characteristic feature.

(Function) In extrusion molding systems, the maximum and minimum allowable temperatures are determined by the molding material used; for example,
In the case of 6063 aluminum alloy specified in LIS H4100, the maximum allowable temperature is about 580°C and the minimum allowable temperature is about 520°C. If the temperature of the forming material when passing through the die exceeds the maximum allowable temperature, the surface of the shape will melt and surface defects will occur, and if it falls below the minimum allowable temperature, the quenching effect cannot be expected and the mechanical strength of the shape will deteriorate. It becomes enough.

On the other hand, the processing heat generated during extrusion molding is closely related to the extrusion speed; as the extrusion speed increases, the processing heat generated increases, and as the extrusion speed decreases, the processing heat decreases. Therefore,
By appropriately controlling the extrusion speed, the shape temperature can be maintained constant.

On the other hand, the processing heat generated differs in various ways depending on the extrusion ratio, die shape, etc. For example, edges tend to be hotter than flat parts, and the higher the extrusion ratio, the higher the processing heat generated. also increases. Furthermore, not only does the amount of heat generated vary depending on other manufacturing conditions, but it is also difficult to accurately control the billet temperature. Therefore, in an extrusion molding system, there are too many factors that affect the temperature of the molding material during extrusion molding, and it is extremely difficult to unambiguously determine the relationship between the optimum temperature of the molding material and the extrusion speed.

Therefore, in the present invention, the maximum temperature in the width direction of the shape material immediately after exiting from the die is detected, and the extrusion speed of the extruder is controlled based on the detected maximum temperature. That is, the optimal extrusion temperature of the molding material to be used is set in advance, the temperature difference between the detected maximum temperature of the shaped material and the optimal extrusion temperature is determined, and the extrusion speed is corrected and controlled based on the determined temperature difference. When controlling this extrusion speed, the molding material used, the extrusion ratio of the shape material,
Consider billet diameter, cross-sectional shape of profile, etc. For example, the relationship between the extrusion ratio and extrusion speed and the processing heat generated is determined in advance and stored in the computer's memory, and the extrusion speed is corrected to become faster or slower depending on the obtained temperature difference. Control. In this way, by detecting the maximum temperature of the shaped material immediately after injection and controlling the extrusion speed of the extruder, automatic extrusion molding with feedback control can be realized, and various factors such as extrusion ratio, billet temperature, and environmental conditions can be realized. Even if the extrusion temperature changes, the temperature of the molding material during extrusion molding can always be maintained at the optimum extrusion temperature, thereby further stabilizing the quality of the product and improving the yield. Furthermore, since the maximum temperature of the shaped material immediately after ejection is controlled to approximately match the optimum extrusion temperature, the extrusion speed can be set higher and production efficiency is also improved.

(Example) FIG. 1 is a diagram showing the configuration of an example of an automatic extrusion molding system according to the present invention, and FIG. 2 is a block diagram showing the configuration of its control circuit. The billet is heated to a predetermined temperature, and the heated billet 7) is placed in the container of the extruder 1. The extruder I can change the extrusion speed by controlling a hydraulic system controlled by an electronic circuit.

The billet is extruded through a die 2, and sections 3 are continuously extruded. A temperature detection sensor 4 for detecting the temperature of the extruded section 3 is arranged on the exit side of the die. This temperature detection sensor uses a radiation thermometer to detect the temperature of the shape in a non-contact manner and continuously over time.

Further, as will be described later, this temperature detection sensor scans in the width direction perpendicular to the extrusion direction and detects the maximum temperature in the width direction of the extruded shape. During extrusion molding, data such as the type of molding material to be used and the extrusion ratio are manually input to a central processing unit (CPU) 11 via a human input device 10. The central processing unit 11 determines the optimum extrusion temperature, optimum extrusion speed, etc. based on the input data and the data stored in the memory. The optimum extrusion temperature is slightly lower than the maximum allowable temperature of the profile. Note that the determined conditions are
It can also be displayed in 3. From CPUII, extruder 1
A control signal is supplied to an extruder drive circuit 14 that controls the drive of the extruder 1, and a drive signal is supplied from the drive circuit 14 to the extruder 1 to start extrusion work at an extrusion speed determined by the CPU. CPtJll sequentially takes in the scan temperature and maximum temperature of the profile detected by the temperature detection circuit 4, and compares the maximum temperature with the optimum extrusion temperature to determine the temperature difference AT. Then, a correction signal for correcting and controlling the extrusion speed is created from the obtained temperature difference AT, the data stored in the memory, and the time interval of the maximum temperature taken in sequentially, and sent to the extruder drive circuit 14. Then, a drive signal for correcting and controlling the extrusion speed of the extruder 1 is generated in the extruder drive circuit to control the extrusion speed.

In this case, if the detected maximum temperature of the shaped material is lower than the optimum extrusion temperature, the extrusion speed is controlled to be faster, and if it is higher, the extrusion speed is controlled to be slower. in this way,
Temperature difference AT between the detected maximum temperature of the shaped material and the optimal extrusion temperature
By determining the temperature difference and controlling the extrusion speed based on this temperature difference, a feedback loop is formed, so that the profile temperature can be automatically maintained at the optimum extrusion temperature.

Figure 3 shows the configuration of the temperature detection system, and Figure 3a
is a plan view, and the third part is a side view. The radiation type temperature detection sensor 20 is attached to a support member 21 so as to face the profile 3, and this support member is attached to the guide shaft 22 and the drive shaft 23. Both ends of the guide shaft 22 are fixed to a pair of housings 24a and 24b, and both ends of the drive shaft 23 are rotatably mounted via bearings.

One end of the drive shaft is connected to a servo motor 25. Drive shaft 2
3 has a spiral groove formed on its outer periphery, and the servo motor 2
5 rotates, the support member 21 and the temperature detection sensor 20 are moved along the arrow a or b direction, that is, in a direction perpendicular to the extrusion direction of the section 3. The amount of movement of the temperature detection sensor 20 is determined from the amount of rotation of the servo motor 25. In addition, a photoelectric remic switch (
A photoelectric switch (not shown) is provided in the center to determine the movement limit position of the sensor, and a photoelectric switch (not shown) is also provided in the center to determine the reference position of the temperature detection sensor at the time of starting measurement. The temperature detection sensor 20 is assumed to move intermittently,
For example, if the amount of movement in one scan is 5 mm, the movement amount is 1 in 1 second.
The temperature of each part is detected for each scan and sent to the arithmetic processing unit.The arithmetic processing unit calculates the actual temperature of the shape and supplies it to the CPU II. Therefore, CP[1
11, the temperature information measured for each scan is sequentially entered manually. Note that the scan width and scan speed can be freely set depending on the type and structure of the shape.

FIG. 4 is a block diagram showing the configuration of a control circuit for detecting the maximum temperature of the profile. A detection signal from the temperature detection sensor 20 is converted into a digital signal by an A/D converter 30 and then supplied to an arithmetic processing circuit 31 for arithmetic processing to determine the temperature of the shaped material. The obtained temperature signal is supplied to a comparator 32 and a register 33. Then, the output part of the register 33 is connected to the other human power part of the comparator 32, and the latch circuit 3
Also connect to 4. The register 33 sequentially stores new measured values for each measurement and sequentially outputs the previously stored measured values. Therefore, the comparator 32 compares the current measurement value with the previous measurement value, and outputs a positive signal if the current measurement value is greater than or equal to the previous measurement value, and outputs a negative signal if it is smaller. Output. The motor drive circuit 35 generates a motor drive signal based on the positive or negative signal output from the comparator 32, and when a positive signal is supplied, moves the temperature detection sensor 20 one pitch in the same direction as the previous movement direction. A drive signal for movement is generated, and when a negative signal is input manually, that is, when a temperature lower than the previous time is detected, a drive signal for movement by one pitch in the opposite direction of movement to the previous movement direction is generated. Therefore, the temperature detection sensor continues to move toward the section of the section with the highest temperature in the width direction, and when it passes through the section with the highest temperature in the width direction one pitch, the section with the highest temperature is detected, and the direction of movement is reversed. Move in the opposite direction. As a result, the temperature detection sensor scans the profile along the width direction, centering on the area with the highest temperature. On the other hand, the latch circuit 34 sequentially captures the measured values output from the register 33.
Ki. Then, based on the positive or negative signal from the comparator 32, when a positive signal is input, the launched measurement value is reset, and when the force detection temperature is reversed to a lower temperature and a negative signal is input manually, the latched measurement value is reset. 1 shift is supplied to CPU II. As a result, the highest temperature detected by the temperature detection sensor while scanning in the width direction is supplied to CPIJII. Note that the signal processing operation of the control circuit for detecting the maximum temperature is performed under the control of CPt1ll.

With this configuration, the temperature detection sensor quickly detects the maximum temperature in the width direction of the profile, and scans along the width direction centering on the area with the highest temperature.
The maximum temperature is detected without scanning the entire width of the profile, and the detected maximum temperature is output to CPt1ll. - In extrusion molding for boat fishing, it is extremely inefficient to scan the entire width of the profile due to the high extrusion speed and short extrusion time per piece. On the other hand, the part that will reach the highest temperature can be predicted to some extent based on the shape of the die and other factors. Therefore, the technology used in this example, which detects the maximum temperature of a shaped material in a short time by sequentially comparing the detected temperatures, can detect the maximum temperature in a short time without scanning the entire width, and can improve the extrusion molding system. This is an extremely advantageous method for automation.

(Effects of the Invention) As explained above, according to the present invention, the temperature difference between the maximum temperature of the shape extruded from the die and the optimum extrusion temperature is determined, and the extrusion speed of the extruder is determined based on the determined temperature difference. Since it is configured to control, the temperature of the molding material during extrusion molding can be automatically maintained at the optimum extrusion temperature. As a result, product quality can be further improved and production efficiency can be further increased.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an example of an automatic extrusion molding system according to the present invention, FIG. 2 is a block diagram showing the configuration of the control circuit, and FIGS. 3 a and b are plan views showing the configuration of the temperature detection system. The side view and FIG. 4 are block diagrams showing the configuration of the control circuit of the temperature detection system.

Claims (1)

[Claims] 1. Means for detecting the maximum temperature in the width direction of the shaped material immediately after extrusion from the die; Means for determining the temperature difference between the detected maximum temperature and the optimum extrusion temperature of the molding material; 1. An automatic extrusion molding system characterized by comprising means for controlling the extrusion speed of an extruder based on the temperature difference between the extrusion molding and the extrusion molding system, and configured so that the temperature of the molding material during extrusion molding is always maintained at a constant temperature. 2. The maximum temperature detection means includes a temperature detection sensor that sequentially detects the temperature of the shaped material extruded from the die at a predetermined cycle, and a drive device that moves this temperature detection sensor one pitch at a time in a direction perpendicular to the extrusion direction. and a comparator that sequentially compares the detected temperatures that have changed over time, and a drive signal that generates a drive signal that moves the temperature detection sensor in the same direction as the previous movement direction if the current detection temperature is higher than the previous detection temperature. a drive signal generation circuit that generates a drive signal to move in the opposite direction when the temperature is lower, and an output circuit that outputs the previously detected temperature as the maximum temperature when the current detected temperature is lower than the previous detected temperature. The automatic extrusion molding system according to claim 1, characterized in that it comprises: