JPH05305647A - Extrusion controlling device of extrusion molder - Google Patents

Abstract

PURPOSE:To make it possible to control the outline dimensions of a product by a method wherein an extrusion molder can be controlled on the basis of the threshold value of extrusion speed exactly corresponding to the actual extrusion speed and, at the same time, the scattering of the characteristics of molding material and of foaming characteristics can be treated. CONSTITUTION:The outline dimensions of an expanded workpiece 30 are detected with a second outline dimension detecting means 18, while the outline dimensions of a workpiece 20 just after the extrusion from the die 6 of an extrusion molder 1 are detected with a first outline dimension detecting means 8. By comparing the detected outline dimensions with the standard outline dimensions, and correcting the dimensional change due to foaming, the extrusion standard corrected dimensions is obtained corresponding to which the corrected speed is determined. The rotational frequency of the screw 3 of the extrusion molder 1 is determined on the basis of the corrected speed corresponding to the extrusion standard corrected dimensions through a screw controlling means 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber extrusion molding machine for foaming, and more particularly to an extrusion control device for making a cross-sectional dimension of an extruded product constant.

[0002]

2. Description of the Related Art Generally, the dimensional accuracy of an extruded product depends on the extrusion amount of a work extruded from a die of an extrusion molding machine. If the extrusion amount is unstable, the dimensional accuracy of the molded product naturally varies. In order to make the extrusion rate constant, first, it is necessary to measure the actual extrusion rate to know the characteristics of the extruder.

Conventionally, as a method for measuring the extrusion rate, a sample is produced by extruding a work for a certain period of time and then cutting it to prepare a plurality of samples, and measuring the weights of the respective samples to compare with each other. The law is known. However, according to this sampling measurement method, not only the measurement efficiency is poor, but also the sampling is intermittently performed, so that the variation in the extrusion amount cannot be continuously obtained. In addition, there is a problem that the measurement accuracy of the extrusion rate is lowered when the cutting accuracy of the sample is poor. In particular, in order to make the cross-sectional size of an extruded product made of a foaming rubber work constant, it was not possible to reduce the variation in the extruded amount without relying on experience.

Therefore, conventionally, the extrusion rate is automatically measured,
A technique has been proposed in which the extruder is feedback-controlled based on the measured value to make the extrusion amount constant. For example, in the method of controlling the extrusion amount disclosed in Japanese Patent Publication No. 62-54654, the viscosity is calculated from the resin pressure measured by the pressure gauge at the tip of the screw and the die inlet resin pressure is measured by another pressure gauge. Detected, the extrusion amount is calculated based on the die inlet resin pressure and the viscosity,
The rotation speed of the screw of the extruder is controlled so that the calculated extrusion amount becomes equal to the preset extrusion amount.

Further, the automatic outer diameter dimension control device for an extrusion molded article disclosed in Japanese Patent Publication No. 56-5178 measures the outer diameter dimension of a work extruded from a die with a non-contact type measuring instrument, and measures it. When the value deviates from the upper limit value and the lower limit value set in advance, the screw speed of the extruder or the rotation speed of the take-up roller is controlled.

[0006]

However, according to the former method of controlling the extrusion amount, the extrusion amount is measured based on the die inlet resin pressure and the viscosity, which are both factors based on the factors in the head. Depending on the operating conditions of
There was a possibility that the measured value did not correspond to the actual extrusion rate. In addition, a special calculation program for calculating the viscosity is required, which complicates the configuration of the control system. In addition, the latter automatic external dimension control device for extruded products performs feedback control of the outer diameter dimension of the work, so a time lag (delay) occurs between the external dimension detection unit and the screw rotation control, and The variation of the extrusion rate due to the change of the extrusion speed cannot be grasped, and the characteristics of the extrusion molding machine cannot be controlled accurately.

Further, in the case of controlling by the extrusion speed of the work, the response is fast and the above-mentioned time lag does not occur, but in the case of, for example, supplying the extrusion molding material by kneading in lots, the material distribution and the time The extrusion molding material and the ambient temperature change from lot to lot, and it is not possible to improve the accuracy of the external dimensions of the product simply by controlling the extrusion speed of the work, especially in the case of an extruded product made of foaming rubber work. The foaming state varies depending on the physical properties of the rubber material (kneading condition, state, heat history, etc.), and the work size after vulcanization (finished product) changes its characteristics in lot units of unvulcanized material. Therefore, when the lot of unvulcanized material is changed, it is difficult to control the extrusion rate of the work so that the work size is always uniform.

Therefore, the object of the present invention is to control the extrusion molding machine based on the threshold value of the extrusion speed that accurately corresponds to the actual extrusion speed, and also to deal with the variations in the characteristics of the molding material and the foaming characteristics. An object of the present invention is to provide an extrusion control device of an extrusion molding machine capable of controlling the external dimensions of a product.

[0009]

In order to solve the above-mentioned problems, an extrusion control device of an extrusion molding machine according to the present invention comprises an extrusion speed detecting means for detecting an extrusion speed of a work extruded from a die of the extrusion molding machine. A first outer dimension detecting means for detecting the outer dimension of the work immediately after being extruded from the die of the extrusion molding machine, and a second outer dimension detecting means for detecting the outer dimension of the work changed by foaming. And a screw control means for controlling the number of revolutions of the screw of the extrusion molding machine so that the extrusion speed of the extrusion speed detection means becomes equal to a predetermined extrusion speed, and foaming detected by the second external dimension detection means. The external dimensions of the work that have changed due to
By comparing with the external dimensions detected by the first external dimension detecting means, an extrusion reference correction dimension in which the dimensional change due to foaming is corrected is calculated, a correction speed corresponding to the extrusion reference correction dimension is determined, and the correction is performed. The speed is used to determine the rotation speed of the screw.

[0010]

In the extrusion controller of the extrusion molding machine of the present invention, the outer dimensions of the work immediately after being extruded from the die of the extrusion molding machine are detected by the first outer dimension detection means, and the work changed by foaming. The outer dimension of the second outer dimension is detected by the second outer dimension detecting means, and compared with the set outer dimension reference dimension, and the outer dimension immediately after extrusion is changed by foaming. The change in the external dimension changed due to this foaming is corrected and used as the extrusion reference corrected dimension. Then, the extrusion speed corresponding to the extrusion reference correction dimension is determined, and the screw control means determines the rotation speed of the screw based on the extrusion speed. As a result, it is possible to match the outer dimensions of the workpiece, which have been detected by the second outer dimension detecting means and have changed due to foaming, with the particular outer dimensions.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a structural explanatory view showing an extrusion control device of an extrusion molding machine according to an embodiment of the present invention, and FIG. 2 is a flow chart explaining the operation of the extrusion control device of an extrusion molding machine according to an embodiment of the present invention. is there.

As shown in FIG. 1, a screw 2 is built in a cylinder 2 of an extruder 1, and the screw 3 is rotated by a driver 4. The rubber material in the cylinder 2 is supplied from the outside as a tape-shaped unvulcanized rubber material 10 and is kneaded by the screw 3 to form the head 5
It is extruded with a predetermined cross-sectional shape from the die 6 provided in the.

An extrusion speed detecting means 9 is arranged near the die 6 outside the head 5. The extrusion speed detecting means 9 of the present embodiment is composed of, for example, a roller that comes into contact with the work 20 and rotates, and an encoder that detects the number of rotations of the roller, but a non-contact type speed detector is used. It is also possible to use.

In this embodiment, the work extruded by the extrusion molding machine 1 and vulcanized is the unvulcanized rubber material 10 of the material.
An unfoamed product immediately after being extruded by the extrusion molding machine 1 will be referred to as a work 20, and a product that has been foamed or has completed foaming through a vulcanization step will be referred to as a work 30.

A first external dimension detecting means 8 for detecting the external dimension of the work 20 immediately after being extruded from the die 6 is provided near the die 6 outside the head 5. As the first external dimension detecting means 8 of this embodiment, a laser type detector capable of detecting in a non-contact state is used.

Then, the work 20 extruded from the die 6 of the head 5 is supported by the roller conveyor 7 or the like and conveyed to the UHF tank 11 for vulcanization by microwave heating. In this UHF tank 11, the conveyed work 20 is heated by microwaves to about 160 to 180 degrees to cause foaming, and then it is sent to the first HAV tank 12. In the first HAV tank 12, the work 30 during vulcanization is stabilized by exposing it to a hot air of about 200 to 220 degrees. Even in the same second HAV tank 13 that is continuously arranged, the vulcanization is finished by exposing the work 30 to hot air of about 200 to 220 degrees to remove the strain and bring the work 30 to a steady state and stabilize it.

The first HAV tank 12 and the second HAV tank 13
A second external dimension detecting means 18 for detecting the external dimension of the work 30 in the middle of vulcanization is provided between the and. As the second external dimension detecting means 18 of this embodiment, the same laser type detector as the first external dimension detecting means 8 is used. In particular, in the present embodiment, the second external dimension detecting means 18 completes the vulcanization sent from the second HAV tank 13 and does not detect the external dimension of the work 30 in the shape of the product. This is to reduce the time lag between the work 20 extruded from the die 6 of 5 and the work 30 that has been completely vulcanized. Of course, when the response may be slightly delayed, the outer dimensions of the vulcanized work 30 delivered from the second HAV tank 13 may be detected. However, since the second HAV tank 13 generally has a length of about 8 to 16 m or more, by improving the responsiveness,
The quality of the entire work 30 can be improved.

In FIG. 1, a take-up machine (not shown) is provided on the right side of the second HAV tank 13.

Next, the structure of the control circuit in the extrusion controller of the extrusion molding machine of this embodiment will be described.

The external dimension De signal of the second external dimension detecting means 18 for detecting the external dimension of the work 30 during vulcanization is
It is input to the set size comparison means 21 for comparison with the set outer shape reference size Dte signal. This setting outline reference dimension Dte signal is
It is a preset external dimension of the vulcanized work 30 delivered from the second HAV tank 13. Then, the outer dimension of the work 30 in the course of vulcanization sent from the first HAV tank 12 is detected by the second outer dimension detecting means 18 and the outer dimension De is compared with the set outer dimension reference dimension Dte. The outside reference dimension Dte (= De) is used.

By the set dimension comparison means 21, the outer dimension De signal of the work 30 during vulcanization and the set outer dimension reference dimension D are obtained.
When the difference from the te signal ± α = De-Dte (the positive and negative signs indicate positive and negative with respect to the set outer shape reference dimension) is calculated, it is input to the extrusion reference dimension correction means 22, and therein, the work being vulcanized. A correction value β for comparison with the external dimension Di signal of the work 20 immediately after being extruded from the die 6 is obtained corresponding to the difference α signal between the external dimension De signal of 30 and the set external reference dimension Dte signal.

Then, the correction value β from the extrusion reference dimension correcting means 22 is inputted to the extrusion dimension comparing means 23, and here the first external dimension for detecting the external dimension of the work 20 immediately after being extruded from the die 6 is detected. The value obtained by comparing the output Di signal of the detection means 8 and the extrusion reference dimension Dti signal is corrected. This correction is based on the difference between the output Di signal of the first outer dimension detecting means 8 which has detected the outer dimension of the work 20 immediately after being extruded from the die 6 and the extrusion reference dimension Dti signal. The output correction value β is subtracted. As a result, the error in the external dimensions after vulcanization is γ = Di-Dti
Expressed as a -β signal, which is the reference speed correction means 24
Entered in.

The reference speed correction means 24 inputs the reference speed Vt signal of the work 20 immediately after being extruded, and when the extruded dimension comparison means 23 outputs the γ signal, the speed comparison means 26 outputs. The reference speed Vt that becomes the threshold value δ
Correct the signal. As a result, the threshold value δ of the speed comparison means 26 becomes the threshold value δ = Vt −γ after the reference speed Vt signal is corrected by the γ signal of the extrusion size comparison means 23.

Further, the speed comparison means 26 is a threshold value δ = Vt-γ obtained by correcting the reference speed Vt signal by the γ signal of the extrusion size comparison means 23, and the movement of the work 20 is rotated by the extrusion speed detection means 9. Is detected and compared with the extrusion speed V of the work 20 whose speed has been converted, and the screw control means 2 is used as a specified speed ε = Vt−V−γ signal.
The rotation of the screw 3 is controlled via 7. The screw control means 27 of the present embodiment normally controls the rotation speed of the screw 3 via the driving machine 4 so that the extrusion speed becomes equal to the threshold value δ = Vt−γ obtained by correcting the reference speed Vt signal. Have control.

In this embodiment, the set dimension comparison means 21, the extrusion reference dimension correction means 22, the extrusion dimension comparison means 23, the reference speed correction means 24, and the speed comparison means 26 are converted into a digital circuit as a calculation means 50 composed of a microcomputer. There is.

A keyboard as an input means is connected to the computing means 50, and the set outer shape reference dimension Dte is set.
Signals, extrusion reference dimension Dti signals, reference speed Vt signals, etc. can be input. Of course, external dimension display means such as a CRT or liquid crystal for displaying the external dimensions of the works 20 and 30 and extrusion speed display means such as a character display for displaying the extrusion speed V of the works 20 and 30 can be connected. .. It is also possible to connect a recorder to the calculation means 50, record each of the above-mentioned data, and print it by a printer.

Next, the overall operation of the extrusion control device of the extrusion molding machine of the present embodiment configured as described above will be described with reference to the flow chart of FIG. This program is executed simultaneously with turning on the power of the extruder 1.

When the power of the extruder 1 is turned on, this program starts, and first, in step S1, the memory, output port, predetermined constants and the like necessary for executing this program are initialized. In step S2, the screw 4 starts to rotate at a constant speed by the driver 4 of the extrusion molding machine 1 at a predetermined initial speed. In step S3, using the input means such as a keyboard, the set outer shape reference dimension Dte of the work 30 being foamed, and the work 20 immediately after being extruded from the die 6.
The reference speed Vt for extruding the extrusion reference dimension Dti which is the outer dimension of the workpiece and the extrusion reference dimension Dti of the work 20 immediately after being extruded are set. The work 2 immediately after being extruded at this time
The extrusion reference dimension Dti of 0 can be uniquely associated with the reference speed Vt for extruding the extrusion reference dimension Dti.

In step S4, the second external dimension detecting means 1
External dimension De detected by 8 and set external dimension reference dimension D
Comparing with te, the difference ± α (the positive / negative sign indicates positive / negative with respect to the set outer shape reference dimension) is calculated. And step S
5 by using the difference ± α, the second outer dimension detecting means 18
A correction value β for correcting the outer dimension of the work 30 during vulcanization detected in step S1 is obtained. Next, in step S6, the correction value β
The output Di of the first outer dimension detecting means 8 for detecting the outer dimension of the work 20 immediately after being extruded from the die 6 is compared with the extrusion reference dimension Dti to extrude the work 20 immediately after being extruded from the die 6. Difference from standard size γ = Di -Dti-
Calculate β.

In step S4, the set dimension comparison means 2 is used.
1, and the step S5 is the extrusion reference dimension correction means 2
2. Step S6 constitutes the extrusion size comparison means 23.

In step S7, the difference signal .gamma.
The threshold value δ of the standard speed is corrected by the reference speed signal Vt of, and the threshold value δ = Vt−γ is calculated. Next, step S8
The threshold value δ = Vt−γ corrected by the reference speed signal Vt is compared with the extrusion speed V of the work 20 detected by the extrusion speed detecting means 9 to calculate a speed designation ε = Vt−V−γ, and step 9 is executed. Then, the rotation speed of the driving machine 4 is output to the screw control means 27 as a speed designation ε signal.

In step S7, the reference speed correction means 2 is used.
4 and step S8 constitutes the speed comparison means 26.

In this way, by repeatedly executing the routines from step S4 to step S9, the screw control means 27 controls the rotation speed of the screw 3 via the drive unit 4.

As described above, the extrusion control device of the extrusion molding machine 1 of the present embodiment detects the extrusion speed of the work 20 extruded from the die 6 of the extrusion molding machine 1 by the extrusion speed detecting means 9
And the first external dimension detecting means 8 for detecting the external dimension of the work 20 immediately after being extruded from the die 6 of the extrusion molding machine 1.
And second outer dimension detecting means 18 for detecting the outer dimension of the work 30 that has undergone foaming change due to vulcanization of the first HAV tank 12.
And a screw control means 27 for controlling the rotation speed of the screw 3 of the extrusion molding machine 1 so that the extrusion speed of the extrusion speed detection means 9 becomes equal to a predetermined extrusion speed threshold value Vt. The outer dimension of the work 30 foamed and changed by the outer dimension detecting means 18 is compared with the outer dimension and the set outer dimension detected by the first outer dimension detecting means 8, and the extrusion reference dimension of the work 20 immediately after being extruded. From the difference .gamma. = Di-Dti-.beta. To calculate the extrusion reference correction dimension in which the dimension change due to foaming is corrected, and the speed designation .epsilon. Calculated using the threshold value .delta. = Vt-.gamma. The rotation speed of the screw 3 of the control means 27 is determined.

Therefore, the extrusion control device of the extrusion molding machine 1 of the above embodiment can control the extrusion molding machine 1 based on the actual extrusion speed based on the extrusion speed corresponding to the product size in consideration of the foaming state, Since the accuracy of the external dimensions of the product can be improved, even if the extruding material is changed for each lot, or if the foaming conditions are changed for each lot due to the composition ratio of the extruding material or the composition such as the temperature, it can be changed. By making the correction, the dimensional accuracy of the extruded and vulcanized product can be increased.

By the way, in the above-mentioned embodiment, when comparing the outer dimension of the work 30 foamed and changed by the second outer dimension detecting means 18 with the outer dimension detected by the first outer dimension detecting means 8, first. , The difference α between the external dimension De signal of the work 30 during vulcanization and the set external reference dimension Dte signal is calculated, the correction value β is obtained, and the output Di of the first external dimension detection means 8 is calculated. The value obtained by comparing the signal with the extrusion reference dimension Dti signal is corrected. However, when the present invention is carried out, the conditions of the set outer reference dimension Dte and the extrusion reference dimension Dti are removed, and the outer dimension of the work 30 that has been foamed and changed by the second outer dimension detection means 18 and the first outer dimension are simply changed. The external dimension detected by the external dimension detecting means 8 of No. 1 is compared, and the obtained value is converted into the second value by using an arbitrary parameter for converting the extrusion dimension to the extrusion speed.
Of the external dimensions detected by the external dimension detection means 18 of
It is possible to set the extrusion reference corrected dimension by correcting the dimension change due to foaming obtained by comparing the outer dimension detected by the outer dimension detection means 8 of FIG. Therefore, the calculation of the extrusion reference correction dimension in which the dimension change due to foaming is compensated is calculated by the work 30 that is changed by the foaming detected by the second external dimension detecting means 18.
It can also be obtained by comparing the outer dimensions of the workpiece with the outer dimensions of the workpiece 20 detected by the first outer dimension detecting means 8.

Further, the rotation speed of the screw 3 of the screw control means 27 is determined by using the correction speed corresponding to the extrusion reference correction dimension in the above embodiment, and the work 2 immediately after being extruded is determined.
A difference from the extrusion reference dimension of 0 is calculated as γ = Di-Dti-β to calculate an extrusion reference correction dimension in which a dimensional change due to foaming is corrected, and a threshold value δ = Vt-γ in which the reference speed signal Vt is corrected.
The rotation speed of the screw 3 is determined by the speed designation ε calculated using. However, when the present invention is carried out, the threshold value δ = Vt obtained by correcting the reference speed signal Vt is not always required.
It does not have to be −γ. For example, depending on the control method of the driving machine 4 that controls the rotation speed of the screw 3, only the correction speed requirement for the reference speed signal Vt may be used.

When the present invention is carried out, the shapes of the works 20 and 30 are not particularly limited and can be carried out as an extrusion control device for the works 20 and 30 of various shapes. Further, the positions of the extrusion speed detecting means 9 for detecting the extrusion speed of the work 20 extruded from the die 6 of the extrusion molding machine 1 and the first outer dimension detecting means 8 for detecting the outer dimension of the work 20 are: Either the extrusion speed detecting means 9 or the first external dimension detecting means 8 may be disposed on the die 6 side.

[0040]

As described above, the extrusion control device of the extrusion molding machine of the present invention is configured such that the outer shape of the work changed by the foaming by the second outer dimension detecting means and the extrusion molding by the first outer dimension detecting means. The outer dimensions of the work immediately after being extruded from the die of the machine are detected, and the outer dimensions are compared with the outer dimension serving as a reference to calculate an extrusion reference correction dimension in which a dimensional change due to foaming is corrected, and A correction value corresponding to the extrusion reference correction dimension is determined, and the rotation speed of the screw is determined via the screw control means using the correction value corresponding to the extrusion reference correction dimension.

Therefore, the first outer dimension detecting means for detecting the outer dimension of the work immediately after being extruded from the extruder and the second outer dimension detecting means for detecting the outer dimension of the work foamed and changed by vulcanization. Since the size of the work before and after vulcanization is detected by, the physical properties of the work (kneading conditions,
Even if the foaming state varies depending on the state, heat history, etc.), it is possible to control so that the work size after vulcanization is always uniform. Further, the extrusion molding machine can be controlled based on the extrusion speed corresponding to the product dimension in which the foaming state is taken into consideration with respect to the actual extrusion speed, and the accuracy of the external dimensions of the product can be improved. For example, the dimensional accuracy of the extruded product can be increased even if the extruded material is changed on a lot-by-lot basis and the foaming conditions are changed on a lot-by-lot basis by changing the mixing ratio of the extruded material or physical properties such as temperature.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an extrusion control device of an extrusion molding machine according to an embodiment of the present invention.

FIG. 2 is a flow chart for explaining the operation of the extrusion controller of the extruder according to the embodiment of the present invention.

[Explanation of Codes] 1 Extrusion Molding Machine 6 Dies 8 and 18 External Dimension Detection Means 9 Extrusion Speed Detection Means 11 UHF Tank 12 1st HAV Tank 13 2nd HAV Tank 20 and 30 Work 21 Set Dimension Comparison Means 22 Extrusion Reference Dimension Correction Means 23 Extrusion dimension comparison means 24 Reference speed correction means 26 Speed comparison means 27 Screw control means 50 Computing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masaki Mori Inventor Nagahata, Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi 1st in Toyoda Gosei Co., Ltd. Address inside Toyota Gosei Co., Ltd.

Claims (1)

[Claims] 1. An extrusion speed detecting means for detecting an extrusion speed of a work extruded from a die of an extrusion molding machine, and a first outer shape for detecting an outer dimension of the work immediately after being extruded from the die of the extrusion molding machine. The dimension detecting means, a second outer dimension detecting means which is arranged apart from the first outer dimension detecting means and detects the outer dimension of the work changed by foaming, and the extrusion speed of the extrusion speed detecting means are predetermined. And an external dimension detected by the second external dimension detecting means in an extrusion control device of an extruder, which comprises a screw control means for controlling the rotation speed of the screw of the extrusion molding machine so as to be equal to the extrusion speed of By comparing with the external dimensions detected by the first external dimension detecting means, an extrusion reference correction dimension in which a dimensional change due to foaming is corrected is calculated, and a correction corresponding to the extrusion reference correction dimension is calculated. Determining the degree, using said correction rate corresponding to the extrusion reference correction size, extrusion control system of extruder and determines the rotation speed of the screw of the extruder by the screw control means.