JP3370415B2 - Method and apparatus for controlling shape of extruded rubber member - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a shape of an extruded rubber for maintaining its shape by applying a tensile force or a compressive force to an extruded rubber extruded by an extruder to control the weight per unit length. The present invention relates to a control method and an apparatus thereof.

[0002]

2. Description of the Related Art As a conventional means for controlling the weight of an extruded rubber member, generally, the linear velocity of a drawing conveyor immediately after extrusion is controlled. A means called a weighted conveyor measured value feedback control has been proposed as such means (see Japanese Patent Publication No. 59-4340).
In this system, a weighing device is arranged on the weighing conveyor, and the linear velocity of the drawing conveyor is increased or decreased based on the deviation from the target weight value. According to this, it is not necessary for the operator to monitor, and by changing the target value, it is possible to cope with a large number of small-lot types.

However, since the weight for feedback is on the weight conveyor located on the downstream side of the pull-out conveyor, a control delay occurs at the initial stage, and the delay causes the tip portion of the member to be wasted. . Further, when a large correction is required, the speed of the drawing conveyor is rapidly increased or decreased, but in this case, even a member having elasticity such as extruded rubber may be plastically deformed, and this plastically deformed portion is also included. It is useless.

Therefore, the applicant of the present invention, for the purpose of keeping the weight of the extruded rubber per unit length uniform, conveys the extruded rubber while placing it on the draw-out conveyor, and the extruded rubber placed on the draw-out conveyor. Has been proposed, and the linear velocity of the drawing conveyor is increased or decreased based on the deviation between this measured value and a predetermined weight target value (Japanese Patent Application No. 4-334447).

To enumerate these characteristics, two or more variable speed conveyors having a weighing mechanism are combined, and the weight of the extruded rubber on each conveyor is adjusted by changing the conveyor speed to expand and contract the rubber and adjust the weight. The point is that two or more conveyor speed feedback loops based on the measured weight of extruded rubber are combined, and that feedback control is performed to correct the speed in a long cycle between two or more conveyors. The weight control is performed by giving plastic deformation to the extruded rubber which is caused by the expansion and contraction action generated from the speed difference between two or more conveyors, which is the main control means.

[0006] However, the extruded rubber must maintain a constant speed ratio (draw ratio) so as not to expand or contract when it is transferred using a conveyor at another stage. However, the operation of the conveyor speed (surface speed) by weight control interferes with the maintenance of this draw ratio, and the expansion and contraction may adversely affect the sectional shape. That is, even if the control for making the weight per unit length uniform is effectively performed, there still remains a problem.

Therefore, the speed ratio (draw ratio) between the conveyors is compared with a predetermined speed difference target value, and if there is a difference with the speed difference target value as a result of this comparison, this difference is calculated. Is calculated as the weight of the extruded rubber on the preceding conveyor, the target weight value on the preceding conveyor is corrected, and feedback is performed so that the difference converges (Japanese Patent Application No. 5-136199). ).

As a result, since the weight can be controlled while suppressing the speed difference between the conveyors within the allowable range in which plastic deformation does not occur, it is possible to maintain a uniform weight and a uniform cross-sectional shape.

[0009]

However, with regard to conveyor transportation during steady state, it has become possible to maintain a uniform weight and a uniform cross-sectional shape by the above-mentioned prior art, but in the transition period, that is, when the extruded rubber is For the initial stage of extrusion from the extruder, a target value is manually set as the initial speed of the drawing conveyor.

The following three points can be mentioned as the method of determining the initial speed of the drawing conveyor. Calculated and estimated from the cross-sectional shape of the extruded rubber and the extruder pressure. The speed value when the same member was controlled within the weight and shape standard last time is used as it is. Furthermore, the set value is corrected in consideration of the external environment conditions (temperature, humidity, etc.).

In any of the above methods, in terms of accuracy and reproducibility, set values are recorded for several hundred or more member types currently used,
Maintaining it is cumbersome and time consuming.

In addition, in terms of physical properties and cross-sectional shape, when a new size is newly added, it is very difficult to estimate the size, and the actual values often deviate greatly.

Furthermore, the physical properties of the extruded rubber depend on the external environment,
The speed of the extruded rubber discharged from the extruder greatly changes between lots because it changes depending on the quality of raw materials, the proportion of contaminants, and the like. Therefore, it is very difficult to predict and maintain the initial speed of the pull-out conveyor that receives and conveys it.

That is, at the initial stage of extruding the extruded rubber, the surface speed of the extruded rubber extruded cannot be grasped in advance, and the pull-out conveyor speed is determined by prediction. The difference between the initial speed of the surface speed of the drawing conveyor that receives and conveys the result is that the extruded rubber is given a stretching force. Therefore, the extruded rubber in the initial stage is out of the standard product, and the larger the difference is, the longer it takes until the feedback effect is obtained, and the wasteful material increases.

In consideration of the above facts, the present invention sets the initial speed of the drawing conveyor so as to match the speed at which the extruded rubber is first extruded from the extruder, and expands and contracts to the extruded rubber during the transition period. An object of the present invention is to provide a method and a device for controlling the shape of an extruded rubber member that can reduce the application of force and improve the yield.

[0016]

The invention according to claim 1 is a method for controlling the shape of an extruded rubber for applying a tensile force or a compressive force to an extruded rubber extruded by an extruder to maintain a constant shape. Then, at least the initial discharge speed of the extruded rubber extruded from the extruder is detected, and the linear velocity of the drawing conveyor arranged immediately after the extruder is instructed based on the detection result.

According to a second aspect of the present invention, the extruded rubber extruded from the extruder is disposed immediately after the extruder and is disposed between the extruder and the conveyor. Speed detection means for detecting the extrusion speed of the extruded rubber to be extruded, and at least the linear speed setting for setting the linear speed of the drawing conveyor based on the detection result by the speed detection means at the initial stage of extrusion of the extrusion rubber from the extruder. And a control means for operating the drawing conveyor based on the linear velocity set by the linear velocity setting means.

A third aspect of the present invention is a method for controlling the shape of an extruded rubber for applying a tensile force or a compressive force to the extruded rubber extruded by the extruder so as to maintain a constant shape, at least the extruder. Detects the discharge speed of the initial extruded rubber extruded from, sets the linear speed of the drawing conveyor arranged immediately after the extruder, operates the drawing conveyor at this set linear speed, and pushes the extruded rubber into the drawing conveyor. And, while carrying it while placing it on the transport conveyor of the next stage and thereafter, measure the weight of the extruded rubber on this pull-out conveyor and the transport conveyor, and compare the measured value on each conveyor with a predetermined weight target value. Then, the linear velocity of each conveyor is increased or decreased, and the speed ratio between the conveyors due to the increase or decrease of the linear velocity is compared with a predetermined speed difference target value, and this difference is calculated. Converted to the weight of the extruded rubber on the stepped conveyor, correct the weight target value and feed back so that the difference converges, and the weight measurement value measured on each conveyor, and the predetermined weight. It is characterized in that the weight target value in the preceding conveyor is corrected based on this deviation so that the steady deviation from the target value converges.

[0019]

According to the first aspect of the present invention, the extruded rubber is extruded from the extruder and the discharge speed of the extruded rubber is detected before reaching the drawing conveyor. Since the linear speed of the drawing conveyor is instructed based on the speed actually detected, it is possible to reduce the application of the stretching force to the extruded rubber due to the speed difference and improve the yield.

According to the second aspect of the invention, the speed detecting means is interposed between the extruder and the drawing conveyor, whereby the extruded rubber discharged from the extruder is detected before reaching the drawing conveyor. The speed is detected by the means.

The linear velocity setting means sets the linear velocity of the drawing conveyor based on the detected velocity of the extruded rubber. Since the control means controls the drawing conveyor to operate based on the set linear velocity, the extruded rubber can be stably conveyed without being expanded or contracted from the initial stage.

According to the third aspect of the present invention, in the initial stage of extruding the extruded rubber from the extruder, the speed of the extruded rubber extruded is detected, and the drawing conveyor is operated based on the detection result.

As a result, the transition period can be shortened and waste of the extruded rubber can be eliminated.

Then, the weight of the extruded rubber on each conveyor is measured, and the measured value is compared with a predetermined weight target value to increase or decrease the linear velocity of each conveyor. As a result, the extruded rubber is conveyed with a substantially constant weight without expanding and contracting.

Here, if the increase / decrease in linear velocity is controlled for each conveyor, that is, in a stand-alone manner, the extruded rubber stretched between a plurality of conveyors is plastically deformed and the cross-sectional shape becomes uneven. May be. Therefore, the speed ratio (draw ratio) between the conveyors is compared with a predetermined speed difference target value. As a result of this comparison, if there is a difference with the speed difference target value, convert this difference as the weight of the extruded rubber on the preceding conveyor and correct the weight target value on the preceding conveyor to obtain the difference. Feedback so that is converged.

As a result, the weight can be controlled while suppressing the speed difference between the conveyors within the allowable range in which plastic deformation does not occur, so that a uniform weight and a uniform sectional shape can be maintained.

When weight control is performed on each conveyor, a steady deviation may occur between the weight measurement value measured on each conveyor and a predetermined weight target value. By correcting the target weight value of the preceding conveyor based on this deviation, the weight can be converged by the weight control of the preceding conveyor, and stable weight control can be performed.

In this way, by correcting the adverse effect (plastic deformation or steady deviation) caused by the weight control,
A uniform weight can be maintained and a uniform cross-sectional shape can also be maintained, so that a high quality product can be produced.
Further, since the delicate adjustment that has hitherto relied on the skilled operator can be automated by the correction, the work efficiency is significantly improved.

Further, even in the initial stage of extruding the extruded rubber, the speed of the drawing conveyor can be set extremely close to an appropriate value, so that the product yield can be improved.

The speed of the extruded rubber discharged from the extruder may be constantly detected. For example, the linear speed of the drawing conveyor is set by detecting variations in speed that may occur during operation earlier than feedback control. By doing so, it is possible to reduce the occurrence of defective products due to speed variations.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an extruded rubber conveying device 10 according to this embodiment.

An extruder 12 is provided on the most upstream side of the conveying device 10.
And a flat plate-shaped extruded rubber 14 applied to a tread of a tire or the like from the mouthpiece 12B of the extruding head 12A by driving an extruding screw (not shown).
(Hereinafter, referred to as unvulcanized rubber 14) is extruded. The unvulcanized rubber 14 that has been pushed out is sent to a drawing conveyor 16 arranged on the downstream side of the extruder 12.

Here, a roller 70 is arranged between the extruder 12 and the drawing conveyor 16 (in FIG. 1, outside the bent portion whose direction is changed from the state of hanging from the extruder 12 to the horizontal state). . This roller 70 has an unvulcanized rubber surface 1
4 is attached in a state of being in contact with 4. In order to maintain this contact state, a small-diameter roller 72 is provided inside the bent portion of the unvulcanized rubber 14.

Thus, the roller 70 and the small diameter roller 72 are
Since the unvulcanized rubber 14 advances while being sandwiched by, the roller 70 rotates according to the moving speed of the unvulcanized rubber 14.

A pulse oscillator 74 is attached to the roller 70 for outputting a pulse every predetermined number of revolutions (for example, 1/2 revolution, which may be less than one revolution). Then, according to the rotation of the roller 70, a pulse is supplied to the drawing conveyor speed control unit 76.

As shown in FIG. 8, the pull-out conveyor speed control unit 76 is provided with a speed calculator 78 that receives a signal from the pulse oscillator 74. In this speed calculator 78,
The transport speed of the unvulcanized rubber 14 is calculated from the circumference of the roller 70 and the number of pulses per unit time.

The calculated result is sent to the calculator 80, and after the correction coefficient for each rubber type sent from the shrinkage suppression correction coefficient setting unit 82 is added, it is supplied to the drawing conveyor speed instruction and the controller 84. It has become. In the pull-out conveyor speed instruction / control unit 84, the speed instruction value of the pull-out conveyor 16 is converted into an electric signal from the obtained transport speed (corrected) of the unvulcanized rubber 14, and the output from the pull-out conveyor speed control unit 76 is output. The signal is sent to the pull-out conveyor speed setting device 86 as a signal.

The pull-out conveyor speed setting device 86 finally determines the speed of the pull-out conveyor 16 and can be manually set if necessary. However, normally, the signal from the pull-out conveyor speed control unit 76 is supplied to the comparison calculator 58 described later. The rotation speed of the motor 22 is controlled based on the signal from the comparison calculator 58.

The pull-out conveyor 16 is composed of a pair of rollers 18 and an endless belt 20 wound around these rollers 18. The drive shaft of the motor 22 is connected to the pair of rollers 18 via a connecting means (not shown). The endless belt 20 is driven in the direction of arrow A in FIG. 1 by driving the motor 22.

The unvulcanized rubber 14 extruded from the extruder 12 is placed on the endless belt 20 of the drawing conveyor 16 and is conveyed by driving the endless belt 20.

An intermediate portion of the pull-out conveyor 16 is recessed by a guide roller 23, and a mini continuous scale 24 is arranged in this recessed portion. In this mini continuous scale 24, the weight per unit length of the unvulcanized rubber 14 placed on the pull-out conveyor 16 is measured while the unvulcanized rubber 14 is conveyed. The placement surface is flush with the surface of the belt where the recess is not formed.
Further, in the mini continuous balance 24, the measured weight is converted into an electric signal by the signal converter 26 and input to the comparison calculator 28. A reference signal (mini scale weight setting value) corresponding to a predetermined target weight per unit length is input to the comparison calculator 28.

Further, a TUC sticking mechanism 30 is arranged in the middle of conveyance of the pull-out conveyor 16. This TUC
The sticking mechanism 30 is provided with a pair of rollers 32 that press the rubber member 34 into a thin shape, and sticks the rubber member 34 to the unvulcanized rubber 14 according to the type of product.

A continuous weighing conveyor 17 is arranged on the downstream side of the drawing conveyor 16. The continuous weighing conveyor 17 is composed of a pair of rollers 36 and an endless belt 38 wound around these rollers 36. The drive shaft of the motor 40 is connected to the pair of rollers 36 via a connecting means (not shown). When the motor 40 is driven, the endless belt 38 is driven in the direction of arrow B in FIG.

The unvulcanized rubber 14 extruded from the extruder 12 is placed on the endless belt 38 of the continuous weighing conveyor 17 via the pull-out conveyor 16 and is conveyed by driving the endless belt 38. ing.

The continuous balance conveyor 17 is recessed at its intermediate portion by the guide rollers 42, and the continuous balance meter 44 is disposed in this recessed portion. This main balance 44
In the above, the weight per unit length of the unvulcanized rubber 14 placed on the continuous weighing conveyor 17 is measured, and the placing surface is flush with the belt surface of the portion not recessed. Has become. Further, in the main scale 44, the measured weight is converted into an electric signal by the signal converter 46 and input to the comparison calculator 48. A reference signal (main scale weight setting value) corresponding to a predetermined target weight per unit length is input to the comparison calculator 48.

The continuous weighing conveyor 17 can be arranged in a plurality of stages as needed, and forms a conveying path for the unvulcanized rubber 14. In addition, in the present embodiment, in order to facilitate the description, one pull-out conveyor 16 and one continuous weighing conveyor 17 are used.

The comparison calculator 48 outputs the difference between the set weight of the main balance and the measured value from the signal converter 46, and inputs the difference to the main controller 50 and the bias correction controller 52. .

As shown in FIG. 2, the bias correction controller 52 has a condition judgment gate circuit 52A as an input terminal, and the gate is opened only when the input signal (deviation) does not exceed a predetermined threshold value. It is like this. When the gate of the condition determination gate circuit 52A is opened, the average value of the deviation of the input signal is calculated by the deviation average calculator 52B and sent to the weight converter 52C. A signal (weight conversion value) for changing the speed is output.

As shown in FIG. 3, the weight converter 5
The 2C includes an output gain calculator 52D, a manipulated variable-weight converter 52E, and a signal processor 52F, and the signal processor 52F gently changes the rise time of the signal obtained by the manipulated variable-weight converter 52E. The signal is output after being converted to a signal that has a positive rise time.
This gentle signal prevents an extreme speed change due to the correction.

In the main balance weight controller 50, the rotation speed of the motor 40 is set based on the difference, and the comparison calculator 54
It is designed to be input to. In the comparison calculator 54,
The rotation speed input from the main balance weight adjuster 50 is adjusted by a signal from a draw specific speed adjuster 56, which will be described later, and then supplied to the motor 40. Motor 40
Are driven to rotate based on the supplied rotation speed signal.

To the draw ratio speed controller 56, a signal (an output signal from the comparison calculator 58) corresponding to the rotation speed of the motor 22 on the side of the drawing conveyor 16 and a draw ratio set value are inputted, and Unvulcanized rubber 14 on conveyor 16
The transport speed of the unvulcanized rubber 14 on the continuous weighing conveyor 17 within a permissible range of the draw ratio set in advance at the transport speed of is determined, converted into weight, and input to the comparison calculator 54. Has become. Therefore, the comparison calculator 54
Then, it is possible to prevent the speed given from the main balance weight adjuster 50 from being far from the transfer speed on the drawing conveyor 16 (limitation of the adjustment range).

The output of the comparison calculator 54 is also input to the comparison calculator 60 to which the draw ratio set value is inputted, and the difference between the actual draw ratio and the set draw ratio is calculated, and the draw ratio correction adjuster is calculated. It is input to 62. The draw ratio correction controller 62 calculates a correction value for converging the difference (deviation) between the actual draw ratio that remains steadily and the set draw ratio by controlling the conveying speed on the side of the drawing conveyor 16, and the mini value is adjusted. The continuous balance weight set value is input to the comparison calculator 28.

As shown in FIG. 4, the draw ratio correction adjuster 62 comprises an output gain calculator 62A and a weight converter 62B for converting the manipulated variable into weight.

Therefore, after the control value obtained by the measured weight and the weight set value in the mini scale 24 is corrected by the correction value input from the draw ratio correction controller 62, the comparison calculator 28 corrects it. , Is input to the mini-repeating scale weight controller 64. In the mini continuous weighing controller 64,
The manipulated variable is output based on the signal from the comparison calculator 28, and is input to the comparison calculator 58. Therefore, the motor 22 is driven based on the difference between the signal from the pull-out conveyor speed setting device 86 and the operation amount.

The operation of this embodiment will be described below with reference to the flowchart of FIG. First, in step 100, control constants such as a mini-repeated balance weight set value, a main-retained balance weight set value, and a draw ratio set value are set, and in the next step 102, driving of the extruder 12 is started.

In the next step 103, the drawing conveyor linear velocity setting control (see FIG. 9) is executed. That is, when the extruder 12 is driven, the unvulcanized rubber 14 applied to the tread of the tire or the like causes the extruder head 1 of the extruder 12 to move.
The roller 70 is pushed out from the base 12B of 2A and hung down,
Also, the direction is changed to the horizontal state while being sandwiched by the small diameter rollers 72.

Here, the roller 70 is applied as a means for detecting the conveying speed of the unvulcanized rubber 14, rotates according to the conveyance of the unvulcanized rubber 14, and sends a signal to the signal converter 74 at a predetermined interval. Is output (step 20)
0). The signal converter 74 outputs a pulse proportional to the rotation of the roller 70, that is, the conveying speed of the unvulcanized rubber 14, to the pushing member speed calculator 78 (step 202). In the pushing member speed calculator 78, the conveying speed V ₁ 'of the unvulcanized rubber 14 is calculated from the pulse signal (step 204) and output to the calculator 80 (step 206).

In the calculator 80, a correction coefficient corresponding to the current rubber type is fetched from the shrinkage suppression correction coefficient setting section 82 together with the conveying speed of the unvulcanized rubber 14 (step 208).
A value V ₁ (= V ₁ '× α) to which the correction coefficient α is added is output to the drawing conveyor speed instruction and the controller 84 (step 210). Withdrawal conveyor speed instruction, controller 84,
The speed instruction value of the drawing conveyor 16 is converted into an electric signal from the obtained conveying speed (corrected) of the unvulcanized rubber 14 and sent to the drawing conveyor speed setter 86 as an output signal from the drawing conveyor speed control unit 76. . A signal is output from the pull-out conveyor speed setting device 86 to the calculator 58 (step 212). Thereby, the initial speed V of the pull-out conveyor 16
The setting of ₁ is made.

As shown in FIG. 5, in step 104, the operation of the drawing conveyor 16 and the continuous weighing conveyor 17 is started. By this operation, the drawing conveyor 16 conveys the unvulcanized rubber 14 at a speed V ₁ , and the continuous weighing conveyor 17 conveys the unvulcanized rubber 14 at a speed V ₂ .

As a result, the unvulcanized rubber 14 is extruded from the die 12B of the extrusion head 12A of the extruder 12,
The unvulcanized rubber 14 is placed on the pull-out conveyor 16 and conveyed by the endless belt 20. afterwards,
The unvulcanized rubber 14 is delivered to the continuous weighing conveyor 17 and is laid between the drawing conveyor 16 and the continuous weighing conveyor 17 except at the beginning and end of the operation.

In the next steps 106 to 116, weight feedback control on the pullout conveyor 16 is performed. The control system at this time has a flow indicated by a thick line in FIG.

At step 106, on the drawer conveyor 16
If there is unvulcanized rubber 14 in the
If it is determined, the process proceeds to step 108 and the mini continuous balance 24
By weight (W₁ ) Is measured. Then step 11
At 0, the weight setting value W_1rIs read and the next step 1
12, the measured weight W₁ And set value W_1rDifference from dW ₁ 
Is calculated (= W_1r-W₁ ), This deviation dW₁ On the basis of
Speed correction amount V₁ Is calculated (step 114). next
In step 116, the unvulcanized rubber on the pull-out conveyor 16 is
Transport speed V of the frame 14₁ To the correction amount V₁ ’,
New speed V₁Is set and the process proceeds to step 118.
As a result, the pull-out conveyor 16 has the corrected speed V₁ To
As a result, the unvulcanized rubber 14 is conveyed.

If a negative determination is made in step 106, the weight feedback control on the drawer conveyor 16 is not performed, and the routine proceeds to step 118.

In the next steps 118 to 128, weight feedback control on the continuous weighing conveyor 17 is performed. The control system at this time has a flow indicated by a thick line in FIG.

At step 118, it is judged whether or not the unvulcanized rubber 14 is present on the continuous weighing conveyor 17, and if the result is affirmative, the process proceeds to step 120 and the weight (W ₂ ) Is measured. Then step 122
Then, the weight setting value W _2r is read out, and the next step 12
4, the difference dW ₂ between the measured weight W ₂ and the set value W _2r is calculated (= W _2r −W ₂ ), and the speed correction amount V ₂ ′ is calculated based on this deviation dW ₂ (step 126). In the next step 128, the correction amount V ₂ ′ is added to the conveying speed V ₂ of the unvulcanized rubber 14 on the drawing conveyor 16 to set a new speed V ₂ , and the process proceeds to step 130. As a result, the continuous weighing conveyor 17 conveys the unvulcanized rubber 14 at the corrected speed V ₂ .

If a negative determination is made in step 118, the weight feedback control on the continuous weighing conveyor 17 is not performed, and the process proceeds to step 130.

In the next steps 130 to 142, bias correction control between the mini-series balance 24 and the main-series balance 44 is performed. The control system at this time has the flow indicated by the thick line in FIG.

First, at step 130, it is judged whether or not the unvulcanized rubber 14 is placed on both the drawing conveyor 16 and the continuous weighing conveyor 17, and if the judgment is negative, the bias correction control is not performed, The process moves to step 154 described later. When the determination is affirmative, the routine proceeds to step 132, where it is determined whether the latest measured value W ₂ of the main scale 44 is within the control range. That is, if it is out of the predetermined range (especially in the transitional period at the beginning of work), the bias correction control may cause a weight change, which may adversely affect the product. Therefore, when it is determined that the value is out of the range, the bias correction control is not performed, and the process proceeds to step 154 described later.

If it is determined in step 132 that the value is within the range, the process proceeds to step 134, and the weight (W ₂ ) of the unvulcanized rubber 14 is measured by the main scale 44. Next, the _{routine proceeds} to step 136, where the set value W _{2r and} this measured value W ₂
And the difference dW ₂ (= W _2r −W ₂ ) is calculated, and step 13
In step 8, the section average dW ₂ ′ of the deviation dW ₂ is calculated.

In the next step 140, this section average d
A correction amount W ₁ 'of the weight set value W _1r of the mini scale 24 is calculated based on W ₂ ', and then the set value W _1r is calculated in step 142.
Then, the correction amount W ₁ 'is added to obtain a new set value W _1r . As a result, without changing the set value of the main scale 44,
The bias between the serial balances can be converged.

In the next steps 144 to 152, correction control of the draw ratio between the drawing conveyor 16 and the continuous weighing conveyor 17 is performed. The control system at this time is shown in FIG.
The flow is indicated by the thick line in (D).

First, in step 144, the main scale 44
It is determined whether or not the weight measurement value in is within a predetermined range. If it is determined that the value is out of the range, the draw ratio correction control may cause a weight variation, which may adversely affect the product. Therefore, the draw ratio correction control is not performed, and the process proceeds to step 154 described later.

When it is determined in step 144 that it is within the range
Shifts to step 146 and the speed of the drawing conveyor 16
V₁ And the speed V of the continuous conveyor 17₂ And draw ratio dV
(V ₂ / V₁ ) Is calculated, and then in step 148
The difference d between this draw ratio dV and the preset draw ratio D
D (= D-dV) is calculated.

In the next step 150, the correction amount W ₁ "of the weight set value W _1r by the mini continuous balance 24 is calculated based on the deviation dD.
Calculated, then by adding the "correction amount W ₁ to the set value W _1r at step 152, a new set value W _1r, Step 15
Go to 4.

As a result, the set value W _1r of the mini scale 24 is calculated.
Is corrected by two types of correction amounts, the bias correction amount W ₁ 'and the draw ratio correction amount W ₁ ".

In step 154, it is judged whether or not the unvulcanized rubber 14 is present on the pull-out conveyor 16 and the continuous weigher conveyor 17. If it is judged that the unvulcanized rubber 14 is present, the routine returns to step 106 to repeat the above control. Also, negative judgment,
That is, if it is determined that there is not, the process ends.

A concrete example of the above control is shown in FIG. Figure 7
7A is a characteristic diagram of the control amount of the weight feedback control in the pull-out conveyor 16, and FIG. 7B is a characteristic diagram of the control amount of the weight feedback control in the continuous weighing conveyor 17, where the horizontal axis is the time and the vertical axis is the maximum. It is the control amount (%) against the speed (40.0m / min), and the set value B of the drawing conveyor speed is 67.2.
It is 26.9m / min of 5%. Further, the set value D of the draw ratio in the continuous weighing conveyor 17 is 1.016.

In such a setting, as shown in FIG. 7D, the control amount of the pull-out conveyor is negative as the weight of the mini-repeating balance 24 rapidly increases (arrow A in FIG. 7D). To the side (arrow B in FIG. 7A). Also, FIG.
As shown in FIG. 7E, the control amount of the continuous weighing conveyor shifts to the negative side as the weight of the continuous balance 44 rapidly increases (arrow C in FIG. 7E) (FIG. 7B). Arrow D). Then, as the weight is hunted, as shown in FIGS. 7 (A) and 7 (B).
The control amount of is shifting from the negative side to the positive side. Here, as shown by an arrow E in FIG.
There is a steady deviation of the measured weight in 4 (offset to the negative side), and in order to converge this to the set weight,
As shown by an arrow F in FIG. 7 (D), the set weight on the mini scale 24 is changed from the set weight (942 g) to the corrected set weight (93
Corrected to 1g). As a result, the weight is stabilized at the new set value of the mini scale 24 and the set value of the main scale 44. At this point (arrow F in FIG. 7D, arrow G in FIG. 7E), the control amount also becomes the set value (arrow H in FIG. 7A,
The arrow I in FIG. 7B). Thereby, the weight can be kept uniform.

However, as shown in FIG. 7C, the draw ratio is deviated from the set draw ratio even when the weight becomes stable (arrow J in FIG. 7C). Therefore, the weight of the unvulcanized rubber per unit length is uniform, but the cross-sectional shape changes. Therefore, in addition to the weight feedback control in each conveyor, the draw ratio correction control is started from the time point of arrow K in FIG. 7 (E). As a result, the set weight of the mini continuous balance 24 is further corrected, and the draw ratio converges to the set value, as can be seen from the arrow L onward in FIG. 7 (C).

As described above, in the conventional weight control,
Although only the weight is compensated by the continuous balance 44, the plastic deformation to the unvulcanized rubber 14 is performed by the correction of the continuous inter-balance bias and the function of converging the draw ratio to the set value in the present embodiment. The amount can be reduced. That is, in addition to the weight control, the cross-sectional shape, which is an important point in terms of quality, can be kept uniform.

Further, the shape of the mouthpiece 12B of the extruder 12, the draw ratio set value between the continuous balance conveyors 17 theoretically calculated from the physical properties of the rubber raw material, and the weight set value in the main continuous balance 44 are set. There is a case where the value does not match the other set values (the weight set value in the mini continuous balance 24, the transfer speed in the pull-out conveyor 16, etc.). For example, changes in some or all of the conditions (changes in the continuous weighing system, vertical or horizontal position of the conveyor), changes in the rubber type in the same manufacturing process, changes in the external environment, etc. And so on. Even in such a case, the control system can automatically make the correction.

Further, by using the optimum set value obtained as a result of performing the control corresponding to the inappropriate set value, the change of the external environment, and the change of the condition, the control from the next time onward can be performed.
It is possible to shorten the time required for stabilization in the earlier part, reduce the amount of defective products, and improve the production efficiency.

According to this embodiment, even at the initial stage of drawing the unvulcanized rubber 14, the conveying speed of the unvulcanized rubber 14 is positively detected, and the initial speed of the drawing conveyor 16 is set based on the detection result. Since this is done, it is possible to improve the yield which makes it possible to maintain the weight and shape within the standard from the tip of the unvulcanized rubber 14.

In this embodiment, only the speed setting of the drawing conveyor 16 in the initial drawing stage of the unvulcanized rubber 14 is described, but conventionally, during the production (at a steady state) due to the fluctuation of the pressure inside the extruder 12. The variation in the surface speed of the unvulcanized rubber 14 that occurs at 1) can be promptly dealt with by always detecting the variation by the roller 70. That is, conventionally, since this variation is adjusted by the feedback control in the steady state, a control delay occurs (about 3 to 5 minutes). However, by detecting the conveying speed of the unvulcanized rubber 14 by the roller 70, the speed of the pull-out conveyor 16 can be changed immediately, so that this control delay can be eliminated and the occurrence of defective products can be suppressed. can do.

Further, since it is possible to eliminate the management of data of hundreds or more rubber types and the manual setting based on this data as in the prior art, the operability is improved.

Further, the variation due to the external environment depends on the skill of the operator, but by actually measuring the unvulcanized rubber 14, it is not necessary to rely on the skill of the operator, and the working efficiency is improved. To do.

Further, the expansion and contraction suppression depending on the type of unvulcanized rubber was possible only between the conveyors in the latter stage, but in the present embodiment, the conveying speed of the unvulcanized rubber 14 immediately after the extruder 12 is. Since (measured value) can be corrected to suppress expansion and contraction,
Further, the accuracy can be improved.

FIG. 10 shows the actual conveyance speed of the unvulcanized rubber 14, the speed characteristic of the conventional drawing conveyor 16 by manual setting, and the speed specification by actual setting and comparison.

When the speed of the unvulcanized rubber 14 changes like the characteristic A (see the chain double-dashed line in FIG. 10), the conventional pull-out conveyor 16 which is manually set has feedback control (PID control) for a while. Is not performed, and then the characteristic A is gradually followed (see the chain line B in FIG. 10).

On the other hand, in this embodiment, since the conveying speed immediately after the discharge is detected, it is possible to immediately cope with the speed difference and to follow the speed change of the unvulcanized rubber 14 thereafter. (See solid line C in FIG. 10).
The time difference when the chain line B and the solid line C coincide with the two-dot chain line A is directly proportional to the generation of defective products,
According to this example, it can be seen that the number of defective products can be significantly reduced as compared with the conventional case.

In the present embodiment, the roller 70 is used to detect the conveying speed of the unvulcanized rubber 14. However, such contact-type detecting means is contacted with a limit switch, a sprocket or the like to convey the unvulcanized rubber 14. The pulse waveform may be generated by a member that moves in proportion. Further, instead of the contact-type detecting means, a non-contact-type detecting means may be used.

For example, a laser feed monitor (model FC series) manufactured by Keyence Corporation may be used. This device is an object to be measured (unvulcanized rubber 14 in this embodiment).
A one-dimensional image sensor receives a sepeckle pattern (bright and dark mottled pattern) generated by irradiating the surface of the laser with a laser beam to obtain a pulse waveform. Such a non-contact type has no fear of damaging the unvulcanized rubber 14.

[0093]

As described above, the method for controlling the shape of the extruded rubber member and the apparatus therefor according to the present invention are particularly applicable to the first operation of the drawing conveyor so as to match the speed at which the extruded rubber is first extruded from the extruder. It has an excellent effect that the speed can be set, the application of the stretching force to the extruded rubber during the transition period can be reduced, and the yield can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a conveyance device according to an embodiment.

FIG. 2 is a block diagram showing an internal configuration of a bias correction adjuster.

FIG. 3 is a block diagram showing an internal configuration of a weight converter of the bias correction controller.

FIG. 4 is a block diagram showing an internal configuration of a draw ratio correction controller.

FIG. 5 is a flowchart of speed control of each conveyor in a steady state.

FIG. 6 is a block diagram showing a control system related to each control.

FIG. 7 is a characteristic diagram showing a control state.

FIG. 8 is a block diagram showing an internal configuration of a drawing conveyor speed control unit.

FIG. 9 is a control flowchart showing a drawer conveyor initial setting routine.

FIG. 10 is a speed control characteristic diagram of the drawing conveyor.

[Explanation of symbols]

10 Conveyor 12 Extruder 12B base 14 Unvulcanized rubber (extruded rubber) 16 Drawer conveyor 17 Conveyor conveyor 22, 40 motor 24 mini scales 44-piece scale 50-piece scale weight controller 52 Bias correction controller 56 Draw specific speed controller 62 Draw ratio correction controller 64 Mini Scale Weight Controller

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Claims (3)

(57) [Claims] 1. A method of controlling the shape of an extruded rubber for applying a tensile force or a compressive force to an extruded rubber extruded by an extruder so as to maintain a constant shape, at least an initial extruded extruded from the extruder. A method for controlling the shape of an extruded rubber, which comprises detecting a discharging speed of rubber and instructing a linear speed of a drawing conveyor arranged immediately after the extruder based on the detection result. 2. An extruded rubber extruded from the extruder is disposed immediately after the extruder, and an extruding speed of the extruded rubber extruded from the extruder, which is disposed between the extruder and the extruding conveyor. A speed detecting means for detecting, a linear speed setting means for setting the linear speed of the drawing conveyor based on the detection result of the speed detecting means at least in the initial stage of extrusion of the extruded rubber from the extruder, and the linear speed setting means A shape control device for an extruded rubber member, comprising: a control unit that operates the drawing conveyor based on the linear velocity set in step 1. 3. A method of controlling the shape of an extruded rubber for applying a tensile force or a compressive force to an extruded rubber extruded by an extruder to maintain a constant shape, wherein at least an initial extruded rubber extruded from the extruder. The discharge speed of the extractor is detected, and the linear speed of the drawing conveyor placed immediately after the extruder is set, and the drawing conveyor is operated at this set linear speed. It is conveyed while being placed on it, the weight of the extruded rubber on this drawer conveyor and the conveyor is measured, and the linear velocity of each conveyor is compared by comparing the measured value on each conveyor with a predetermined weight target value. The speed ratio between the conveyors due to the increase or decrease of the linear velocity is compared with a predetermined speed difference target value, and this difference is pushed by the preceding conveyor. Converted to rubber weight, correct the weight target value and feed back so that the difference converges, and the steady state of the weight measurement value measured by each conveyor and a predetermined weight target value. A method for controlling the shape of an extruded rubber member, characterized in that the target weight value of the preceding conveyor is corrected based on this deviation so that the actual deviation is converged.