JPH04319419A - Extrusion molding method and its device - Google Patents

Abstract

PURPOSE:To set automatically various kinds of optimum extrusion conditions by measuring the transverse sectional shape of an extrusion molded product, inputting the same into a foregoing section of Fuzzy rule and controlling respective extrusion conditions individually by means of the extrusion conditions set in the following section. CONSTITUTION:A circuit for processing a signal of dimension sensing sensor SD by buffers B3 and B4, resistors R4-R6 and variable resistors VR2 is connected with output terminals of knot gates NOT3 and NOT4. Therefore, in the case a switch SW is connected with an initial setting terminal T3, the value adjusted by the variable resistor VR2 can be output into a Fuzzy theory section 11, while in the case the switch SW is changed over and connected with an automatic operation terminal T4, the value corresponding to the sensed value of the dimension sensing sensor SD can be output into the Fuzzy theory section 11. The optimum number of screw rotations corresponding to the external dimension of an extrusion molded product is presumed by the Fuzzy theory section 11.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is an extrusion method that can extrude rubber or synthetic resin as an extrusion material into a desired cross-sectional shape or with a desired gloss by performing fuzzy reasoning. This invention relates to a molding method and apparatus.

0002

2. Description of the Related Art An example of a conventional extrusion molding apparatus is an extrusion molding apparatus that extrudes a water supply pipe having a ring-shaped cross section.

[0003] This device automatically detects the outer diameter D1 of the extruded pipe at the exit of the extrusion die and determines the reference diameter D1.
2, if the extrusion diameter D1 is smaller than the reference diameter D2, the rotation speed of the motor that drives the screw of the extruder is increased by a predetermined number of rotations, and conversely, when the extrusion diameter D1 is larger than the reference diameter D2, the rotation speed is increased. is lowered so that the extrusion diameter D1 falls within the allowable tolerance of the reference diameter D2.

However, in this type of extrusion device, the extrusion diameter D1 is not only affected by the extrusion speed, but also by the extrusion temperature, such as variations in material properties, material temperature, and the temperature of the adapter or extrusion die. It is not possible to achieve the desired control only by automatically controlling the rotational speed of the screw drive motor, and in order to obtain extruded products with accurate dimensions, each extrusion condition must be adjusted by a skilled person with considerable experience. I had to. The automatic rotational speed control system for the screw drive motor described above, once adjusted by an experienced person, is effective as long as extrusion molding is continued under the same conditions.

[0005] Extrusion molded products are also required to have decorative properties, so it is not enough just to have their shape and dimensions within tolerances; on the other hand, the glossiness, that is, the smoothness of the surface, is also an important factor. Therefore, adjusting each extrusion condition is a difficult task not only for an unskilled person but also for an experienced person, and is especially difficult for a product with an irregular cross-sectional shape.

[0006]

As mentioned above, the conventional extrusion molding apparatus has the problem that extrusion conditions such as temperature and extrusion speed must be adjusted again and again by a skilled person each time.

[0007] Furthermore, even if each extrusion condition is adjusted by a skilled person, the adjustment work is difficult and there is a problem in that a considerable amount of material is used before the optimum extrusion conditions can be set.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an extrusion molding method and apparatus that can optimally automatically set various extrusion conditions by performing fuzzy reasoning based on knowledge data of an experienced person. .

[0009]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an extrusion molding method and an apparatus therefor as set forth in the claims.

0010

[Operation] In the extrusion molding method and apparatus of the present invention, in the above configuration, the cross-sectional shape or outer surface condition of the extruded product extruded from the die is measured. That is, the measured value is input into the antecedent part of the fuzzy rule, and the extrusion conditions are determined in the consequent part of the fuzzy rule. The cross-sectional shape of the molded product may be measured using, for example, a laser type non-contact profile measuring device. In addition, the measurement of the outer surface condition is
For example, a method may be used in which surface gloss is measured by light reflectance, or an image obtained by a CCD camera is processed to measure gloss or surface roughness.

Therefore, according to the extrusion molding method and the extrusion molding apparatus of the present invention, by inputting the measurement or measured value of the cross-sectional shape or the outer surface condition into the antecedent part of the fuzzy rule based on the knowledge data of an experienced person. , the extrusion temperature and extrusion speed can be optimally automatically set to optimally maintain these factors.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram showing an example of the configuration of an extruder in which the present invention can be carried out. In the figure, an extrusion die 3 is fixed to the front of the cylinder 1 (on the right side in the figure) via an adapter 2, and the material is extruded from the front side of the die 3 to obtain an extrusion molded product 4. Let A be the extrusion direction.

A screw 6 having a supply zone, a compression zone, and a measuring zone for extruding the raw material made of rubber or synthetic resin stored in the hopper 5 from the die 3 is rotatably built inside the cylinder 1. . As the screw 6 rotates, the material in the hopper 5 is sent to the compression zone via the supply zone by the fins 6F of the screw 6, where it receives heat from the cylinder 1 and compressive shear force due to the rotation of the screw, and the material It melts as its temperature rises. Further, in the metering zone, a fixed amount of resin is extruded per unit time and is supplied to the die 3 through the flow path in the adapter 2.

A flywheel 7 is connected to the rear end of the screw 6, and the flywheel 7 is connected via a belt or chain 8 to a pulley 9 which is rotationally driven by a screw driving motor M1. Further, the rotation speed of the screw 6 is detected by a screw rotation speed detection sensor SR.

[0016] When there is no force transmission slip between the drive motor M1 and the screw 6, or when it can be virtually ignored, a motor with a built-in rotation speed detection function can be used, and the following explanation will be based on this example. It depends on

On the other hand, in the extruder of this example, the cylinder 1, the adapter 2, and the die 3 are equipped with a cylinder heater HS, an adapter heater HA, and a nichrome wire, respectively.
A die heater HD is provided so that each member can be heated individually. When the heater stops heating, each member is cooled by natural or forced heat radiation or by the material passing through it. Further, each member 1, 2, and 3 is provided with a cylinder temperature detection sensor TS, an adapter temperature detection sensor TA, and a die temperature detection sensor TD that detect the current temperature of each member. Furthermore, a cylinder cooling fan 10 is provided outside the cylinder 1 and is rotationally driven by a cooling fan drive motor M2 in order to forcibly cool the outer wall of the cylinder 1 with cold air. In an actual extrusion molding machine, 1
Each cylinder 1 is provided with 3 to 6 separate heaters and an associated cooling fan, and the die 3 is also provided with 2 to 3 heaters; For simplicity and ease of understanding, the heater and fan are described as one for each member.

Furthermore, in the extruder of this example, in order to detect the shape and gloss of the molded product 4 in front of the die 3,
A dimension detection sensor SD and a glossiness detection sensor SG are provided. The dimension detection sensor SD is composed of, for example, a laser type non-contact external shape measuring device, and measures the cross-sectional dimension of the molded product 4 at an appropriate position. Further, the gloss detection sensor SG is composed of, for example, a pair of light receiving and emitting devices, and measures the glossiness of the molded product 4 according to the amount of light input to the light receiving device.

In the above configuration, each actuator M
1, M2, HS, HA, HD, each sensor SR, TS, T
A, TD, SD, and SG are connected to each signal input/output terminal of a control circuit that controls the entire extruder.

FIGS. 2 and 3 are explanatory diagrams showing one embodiment of the control circuit. Although the circuits shown in FIGS. 2 and 3 are shown separately for reasons of space, they are actually connected integrally via intermediate terminals T1 and T2.

In FIG. 2, a pair of NAND gates (NA
Each signal input terminal T3, T4 of the RS flip-flop composed of
The power supply voltage (
+E) is supplied, and each terminal T3, T4 is connected to a switch S
It is designed to be grounded by switching W. Terminal T3 is a terminal for initial setting, and terminal T4 is a terminal for automatic operation. Therefore, when the switch SW on the initial setting terminal T3 side is switched to the automatic operation terminal T4 side, the RS flip-flop operates inverted, and each NAND gate NAND
1 and 2 output L and H signals from H (high level) and L (low level), respectively.

Two NOT gates NOT1 and NOT are connected to each output terminal of the NAND gates NAND1 and NAND2, respectively.
3, NOT2, and NOT4 are connected in parallel. One set of knot gates NOT1 and NOT2 is related to gloss control, and the other set of knot gates NOT3 and NOT4 is related to external dimension control.

The output terminal of the NOT gate NOT1 is
It is connected to a power supply voltage (+E) supply terminal via a resistor R7, and is also connected to the glossiness detection sensor SG via a series circuit of an amplifier A1 and a diode D1. Connection direction of diode D1 from amplifier A1 to not gate N
This is the forward direction when looking at OT1. Also, amplifier A
1 is connected to one input terminal of an operational amplifier OPA1 whose other input terminal is grounded via a buffer B1 and a resistor R1. The output terminal of the operational amplifier OPA1 is connected to a computer system 11 equipped with a fuzzy inference section (hereinafter simply referred to as a fuzzy inference section). A resistor R2 is connected between one input terminal and the output terminal of the operational amplifier OPA1.
is mediated.

The output terminal of the NOT gate NOT2 is grounded via a buffer B2 and a variable resistor VR1. A contact point of this variable resistor VR1 is connected to one input terminal of the operational amplifier OPA1 via a resistor R3.

Therefore, the switch SW is connected to the initial setting terminal T.
3, and when the output of the NOT gate is at a low level (zero) and the output of the NOT gate NOT2 is at a high level (+E), the output terminal of the amplifier A1 is connected to the NOT gate via the diode D1. Since the output voltage of the glossiness detection sensor is always zero, the value adjusted by the variable resistor VR1 is output from the operational amplifier OPA1 to the fuzzy inference section 11. Furthermore, when the switch SW is switched to the automatic operation terminal T4, the output of the amplifier A1 is inputted to one input terminal of the operational amplifier OPA1 via the buffer B1 and the resistor R1, and the detected value of the glossiness detection sensor SG is input. The corresponding value is the fuzzy inference part 1
It is input to one input terminal of 1.

The output terminals of the NOT gates NOT3 and NOT4 are connected to the already mentioned node gates NOT1 and NOT.
Similarly in case 2, buffers B3, B4, resistors R4 to R
6. A circuit for processing the signal of the dimension detection sensor SD is connected to the variable resistor VR2. Therefore, switch S
When W is connected to the initial setting terminal T3, the value adjusted by the variable resistor VR2 is sent to the fuzzy inference unit 11.
When the switch SW is switched and connected to the automatic operation terminal T4, the dimension detection sensor SD
A value corresponding to the detected value can be output to the fuzzy inference section 11. In this example, the fuzzy inference unit 11 infers the optimum screw rotation speed and die temperature, and outputs the respective inference results to terminals T1 and T2 via buffers B6 and B7. The content of the inference by the fuzzy inference unit 11 will be described later.

In FIG. 3(a), the terminal T1 is
It is connected to one input terminal of the operational amplifier POA3 via a resistor R10. The other input terminal of the operational amplifier OPA3 is connected to the die temperature detection sensor TD via a series circuit of an amplifier A3, a buffer B5, and a resistor R9. A resistor R12 whose one end is grounded is connected to the connection line between the resistor R10 and the operational amplifier OPA3. operational amplifier OP
A resistor R11 is connected between the connection line between A3 and the resistor R9 and the output terminal of the operational amplifier OPA3. Also,
The output terminal of the operational amplifier OPA3 is connected to the phase control type voltage control device 1 that drives the die heater HD via the buffer B8.
2 is connected.

In FIG. 3(a), when the optimum temperature is commanded from the terminal T1, the deviation between the command value and the detected value is detected by the operational amplifier OPA3, and the die heater HD is controlled so that this deviation becomes zero.

On the other hand, in FIG. 3(b), the terminal T2 is connected to the screw rotation speed control device 13. This screw rotation speed control device 13 is connected to a motor drive unit 14 that drives the motor M1. Therefore, when the optimum rotational speed of the motor M1 is output from the terminal T2, the screw rotation control device 13 can rotate the motor M1 at the optimum speed while obtaining a feedback signal of the motor rotational speed from the motor drive unit 14. In other words, it is possible to optimally control the screw rotation speed, that is, the material feed rate which is proportional to the screw rotation speed.

The fuzzy inference section 11 infers the optimum screw rotation speed and die temperature according to the external dimensions and glossiness of the extruded product using the fuzzy rules shown in the following table. FIG. 4 shows an example of the membership function that determines the screw rotation speed and die temperature.

In FIG. 4, the membership function represents the screw rotation speed or the die temperature, and the horizontal axis represents the external dimensions or the degree of gloss.

[0032]

[Table 1]

To give an example of fuzzy reasoning, in Table 1, if the external dimensions of the extruder are normal (within tolerance) and the outer surface has normal gloss (desired gloss), the screw rotation There is no need to change the number or extrusion temperature, but
When the external dimensions increase, it is necessary to lower the screw rotation speed, and when the external surface has no (low) gloss, it is necessary to increase the extrusion temperature. These factors are interrelated, and unilaterally changing the screw rotation speed will have a negative effect on the other factors, making adjustment extremely difficult. However, in this example, the fuzzy reasoning shown in Table 1 and Figure 4 Since the optimum value can be inferred, the screw rotation speed and extrusion temperature can be optimally controlled. The extrusion temperature is generally the die temperature, but the cylinder temperature, adapter temperature, and die temperature can also be controlled together.

[0034] In the extrusion molding apparatus having the above configuration, when a pellet-shaped resin, for example, is put into the hopper 5 as a raw material and the temperatures of the cylinder, adapter, and die are initially set,
After waiting a predetermined time, each part is heated to the set temperature.

Next, when the screw rotation speed is initialized and the motor M1 is driven, the material in the hopper 5 is sent to the outlet side through the supply zone in the cylinder 1 as the screw 6 rotates, and is compressed. In the zone, the resin is melted by heat from the cylinder 1 and compression shearing force due to the rotation of the screw, and a fixed amount of resin is extruded per unit time from the die 3 through the metering zone.

Then, it was confirmed that a molded product with a predetermined cross-sectional shape was extruded from the exit of the die 3, and the dimension detection sensor SD
When the glossiness detection sensor SG is turned on and the switch SW shown in FIG. 2 is switched to the automatic operation terminal T4 side, automatic operation based on the inference of the fuzzy inference section 11 is started.

[0037] In automatic operation, NAND gate NAND1,
Due to the inversion operation of the RS flip-flop consisting of 2,
The cathode sides of diodes D1 and D2 are at high level (+E
), and the detected values of glossiness and external dimensions amplified and adjusted by amplifiers A1 and A2 are changed to buffers B1 and B3 and resistor R.
1 and R4 to the operational amplifiers OPA1 and OPA2, respectively. At this time, the outputs of buffers B2 and B4 become zero due to the inversion operation of the RS flip-flop accompanying the switching operation to automatic operation, so variable resistor VR1
, VR2 to the operational amplifiers OPA1 and OPA2 also become zero.

Therefore, during automatic driving, the fuzzy inference unit 1
The detected values of glossiness and external dimensions are now input to motor M1, and the fuzzy inference results of screw rotation speed and die temperature are output according to the above-mentioned fuzzy rules.
And the die heater HD is optimally controlled.

In the above example, the external dimensions and external surface gloss of the extruded product were taken as the antecedents of the fuzzy rules in Table 1, and the screw rotation speed and the temperature of the extrusion die were taken as the consequents. Dimensions and gloss can also be handled separately. In addition, it is possible to incorporate the temperature of cylinder 1 and the temperature of adapter 2 as a consequent,
This is actually more practical.

Furthermore, in the above embodiment, the control circuit shown in FIGS. 2 and 3 is connected to the extruder shown in FIG. The fuzzy rules of the fuzzy inference unit 11 shown in Table 1 and FIG. The user may be able to select any desired factor. In this way, each user can
It becomes possible to create fuzzy rules based on experience and perform desired control using desired factors.

Furthermore, in the above example, the outer surface condition of the molded product was expressed by the glossiness measured by the light receiving and emitting device, but the outer surface condition is not limited to this, and other conditions such as surface roughness and color tone may be used. It may be. It is also possible to enter visual inspection values into the control panel. Furthermore, the sensor for detecting the outer surface state may be configured with a CCD camera and an image processing device.

In the above embodiment, the temperature of the cylinder and die was measured as a substitute for the temperature of the resin or rubber. You can measure it.

The present invention is not limited to the above-mentioned embodiments, but can be implemented in any appropriate manner by making appropriate design changes.

[0044]

[Effects of the Invention] As described above, the present invention is an extrusion molding method and an apparatus therefor as described in the claims.
The cross-sectional shape or outer surface condition of the extruded product extruded from the die is measured or measured, and this is input into the antecedent part of the fuzzy rule, and the extrusion conditions are determined in the consequent part of the fuzzy rule. By automatically inputting the measured values of the cross-sectional shape or outer surface condition into the antecedent part of the fuzzy rule based on the knowledge data of experienced people, the extrusion temperature and extrusion speed can be optimized to optimally maintain these factors. can be set automatically.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of an extrusion molding machine that can carry out the present invention.

FIG. 2 is a circuit diagram showing a front part of a control circuit that controls the extrusion molding machine.

FIG. 3 is a circuit diagram showing the latter part of the control circuit that controls the extrusion molding machine.

FIG. 4 is an explanatory diagram of a membership function showing an example of the consequent part of the fuzzy rule used in the fuzzy inference part of FIG. 2;

[Explanation of symbols]

1 Cylinder 2 Adapter 3 Die 4 Molded products 6 Screw 11 Fuzzy reasoning part M1 Screw drive motor HS Cylinder heater HA adapter heater HD die heater SG Glossiness detection sensor SD External dimension detection sensor

Claims (4)

[Claims] Claim 1: The temperature and extrusion speed of the extruded material as extrusion conditions can be individually controlled, and the extruded material at the controlled temperature is extruded from a die at the controlled speed to form an extruded product with a desired cross-sectional shape. In the extrusion molding method to obtain, the cross-sectional shape of the extruded product extruded from the die is measured and inputted into the antecedent part of the fuzzy rule,
An extrusion molding method characterized in that the extrusion conditions are set in the consequent part of the fuzzy rule, and each extrusion condition is individually controlled using the set extrusion conditions. 2. The temperature and extrusion speed of the extruded material as extrusion conditions can be individually controlled, and the extruded material at the controlled temperature is extruded from a die at the controlled speed to form an extruded product with a desired cross-sectional shape. In the extrusion molding method to obtain, the outer surface condition of the extruded product extruded from the die is measured and inputted into the antecedent part of the fuzzy rule,
An extrusion molding method characterized in that the extrusion conditions are set in the consequent part of the fuzzy rule, and each extrusion condition is individually controlled using the set extrusion conditions. 3. The temperature and extrusion speed of the extruded material as extrusion conditions can be individually controlled, and the extruded material at the controlled temperature is extruded from a die at the adjusted speed to form an extruded product with a desired cross-sectional shape. In the extrusion molding method to obtain An extrusion molding method characterized by setting conditions and individually controlling each extrusion condition under the set extrusion conditions. 4. The temperature and extrusion speed of the extruded material as extrusion conditions can be individually controlled, and the extruded material at the controlled temperature is extruded from a die at the adjusted speed to obtain an extruded product with a desired cross-sectional shape. In the extrusion molding apparatus, an appropriate number of sensors are provided to measure the cross-sectional shape or outer surface condition of the extruded product extruded from the die, and the detection values detected by these sensors are input into the antecedent part of the fuzzy rule, and the The invention is characterized by comprising a fuzzy inference section that sets extrusion conditions in the consequent part of the fuzzy rule, and an extrusion control device that individually controls each extrusion condition using the extrusion conditions set by the fuzzy inference section. Extrusion molding equipment.