JPH11314261A - Controlling method for bank amount of roller head rubber extruder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling bank amount of a roller head rubber extruder in which bank amount of rubber between a rubber extrusion port of the body of the extruder and calendering rolls is stabilized. SOLUTION: The roller head rubber extruder is equipped with the body 3 of the extruder having a screw 2 for extruding rubber, the upper and lower calendering rolls 5, 6 arranged near to the rubber extrusion port of the body 3 of the extruder and a guiding means which incorporates a side guide performing width decision of rubber extruded from the rubber extrusion port in the interval reaching the calendering rolls 5, 6 and forms a closed bank surrounding the rubber extrusion port and leading rubber. In the controlling method for bank amount, speed of rotation of the screw 2 or speed of rotation of the calendering rolls 5, 6 is regulated by detecting calender current of a calender motor Mc for driving the calendering rolls 5, 6 and comparing the detection value with preset value. Thereby, bank amount is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a bank amount of a roller head rubber extruder capable of stabilizing a rubber bank amount between a rubber extrusion port of a main body of an extruder and a calender roll.

[0002]

2. Description of the Related Art A roller head for directly extruding rubber into a sheet shape by a calender roll by arranging a calender roll in the transverse direction perpendicular to the extrusion direction near a rubber extrusion port of an extruder body. A rubber extruder is used. In such a roller head rubber extruder, there is a roller head rubber extruder that forms a closed bank for preventing rubber leakage between a rubber extrusion port and a calender roll by guide means including a side guide for determining the width of a molded product. .

On the other hand, in order to continuously form the molded body while stabilizing its shape, it is necessary to stabilize the rubber amount in the closed bank, that is, the bank amount within a predetermined range. When it is, the molded product is likely to have a chipped portion of rubber, and when it is excessively large, it will cause rubber leakage from the closed bank, and in any case, the cross-sectional shape of the molded product will fluctuate and the quality will vary. Become.

Therefore, for stabilizing the bank amount, for example, Japanese Patent No. 2698035 discloses a roll housing for supporting a calender roll, or a side guide provided with a detecting means such as a load cell for detecting a rubber pressure in a closed bank. Propose that. This proposal also discloses a case where the output of the detecting means controls the screw of the extruder body and the rotation speed of the calender roll.

[0005]

However, in the closed bank, the change in the rotational speed of the screw is easily increased and decreased immediately by expanding the internal pressure, and the pressure distribution in the rubber in the closed bank is uneven and unintended. As described above, when the rubber pressure in the close bank directly connected to the rubber extrusion port is directly detected without passing through a buffer, the pressure change applied to the load cell is sudden, large, and partial. There is a problem to be solved such that a command hunting is likely to occur due to a case where pressure is detected and an unnecessary change is detected in some cases, and vibration is generated in a machine and noise is increased.

The present invention provides a method for controlling a bank amount of a roller head rubber extruder which can solve the above-mentioned problems, such as preventing hunting, based on detecting and controlling the current of a calender motor for driving a calender roll. The purpose is.

[0007]

In order to achieve the above object, the invention of a bank amount control method for a roller head rubber extruder according to the first aspect of the present invention is directed to an extruder body having a screw for rubber extrusion, and the extruder body. It is arranged near the rubber extrusion port of
A roller head including a lower calender roll, and a guide means including a side guide for deciding the width of the rubber extruded from the rubber extrusion opening to the calender roll, and forming a closed bank for guiding the rubber around the rubber extrusion opening; A method for controlling a bank amount of a rubber extruder, comprising detecting a calender current of a calender motor Mc for driving the calender roll, comparing the detected value with a preset set value, and determining a rotational speed or a rotational speed of the screw. It is characterized in that the bank amount is stabilized by adjusting the rotation speed of the calendar roll.

According to a second aspect of the present invention, when the detected value of the calendar current is larger than the set value, the rotational speed of the screw is reduced or the rotational speed of the calender roll is increased. When the rotation speed is small, the rotation speed of the screw is increased or the rotation speed of the calender roll is decreased.

As described above, in a roller head rubber extruder having a closed bank, since the calendar current of the electric motor for driving the calendar roll is detected and controlled, the rubber in the closed bank becomes a buffer and the closed bank is extruded. By absorbing and controlling sudden changes, variations, and unintended changes in the internal pressure, the pressure over the entire closed bank can be correctly detected and controlled, thereby preventing command hunting and suppressing mechanical vibration and noise.

In the second aspect of the present invention, a preferable adjustment can be performed by performing the above-described control by the feedback control.

[0011]

Preferred embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a roller head rubber extruder 1 to which the method of the present invention is applied is disposed near an extruder main body 3 having a screw 2 and a rubber extrusion port 4 (shown in FIG. 2) of the extruder main body 3. And a guide means 9 including upper and lower calender rolls 5, 6 and side guides 7, 7 for guiding the rubber around the rubber extrusion opening 4. Further, the method of the present invention comprises the steps of:
Detecting the calendar current of the calendar motor Mc that drives the motor, and comparing the detected value Ic with a preset set value Ia to adjust the rotation speed of the screw 2 or the rotation speed of the calendar rolls 5 and 6. To stabilize the bank amount.

The extruder main body 3 is provided with, for example, an extrusion cylinder 15 that accommodates the screw 2 and is provided with a rubber input port 14 at a speed reducing portion 13 disposed on a base 12, for example. The motor rotates by being linked to the screw motor Mr, which is flanged to the speed reducer 13 via the speed reducer 13, for example. By rotation, the kneaded rubber is extruded from the rubber extrusion port 4 formed at the tip of the extrusion cylinder 15.

The extruding cylinder 15 is supported at its tip end by a receiving stand 17 erected on the base 12, and both ends of the calender rolls 5, 6 are pivotally mounted on the receiving stand 17 with the both ends up and down. The roll stand 21 is fixed. The center axes of the calender rolls 5 and 6 are orthogonal to the direction in which the rubber is extruded from the rubber extrusion port 4 and are laterally oriented.

As shown in FIG. 1, the roll stand 21 pivotally supports the lower calender roll 6 at the lower end thereof at substantially the same height as the rubber extrusion port 4, and is provided above the lower calender roll 6. The upper calender roll 5 is supported by a bearing box 24 which can be moved up and down while being guided by the guide window 23. The bearing box 24 is rotatably attached to the bearing box 24 and is moved up and down by appropriate lifting means using a linear motion device such as a screw shaft and other cylinders screwed to the upper end of the roll stand 21. The thickness of the molded product can be adjusted by adjusting the gap between the calender roll 6.

In this embodiment, for example, the rotating shaft of the lower calender roll 6 is linked to a calender motor Mc for driving the calender roll via a speed reducer provided on one of the roll stands 21, and the upper calender roll 6 is connected. 5 is freely rotatable.

The upper calendar roll 5 may be driven, or both calendar rolls 5 and 6 may be driven. At that time, a calendar electric motor Mc may be used for each axis, or both may be driven by a transmission means using one calendar electric motor Mc.

The rubber extrusion port 4 and the calender roll 5,
The guide means 9 is provided between the guide means 9 and the guide means 9. The guide means 9 includes the side guides 7 and 7 and forms a closed bank that surrounds the rubber extrusion port 4 and guides the rubber to the calender rolls 5 and 6.

In the present embodiment, the side guide 7 is shown in FIG.
As shown in FIG. 3, the rubber extruder 4 is formed at the end of the extruder main body 3 and is disposed between the upper and lower leak prevention members 27 on both sides of the flange portion 26 where the rubber extrusion opening 4 is opened. . Further, the side guide 7 has a substantially triangular pyramid shape whose cross-sectional area decreases toward the protruding end side, and the inner side surface 7A facing the rubber extrusion port 4 is inclined laterally outward toward the protruding end side, so that the rubber is formed. The rubber from the extrusion port 4 can flow while widening.

The upper and lower surfaces of the side guide 7 protrude from the leak preventing member 27.
In cooperation with the front of the above, the upper and lower calendar rolls 5,
6 so as not to cause rubber leakage, the front surface of the flange portion 26 and the inner surface 7 of the side guide 7 are formed.
A, and the peripheral surfaces of the upper and lower calender rolls 5 and 6 form the closed bank that seals the rubber together with the leak preventing material 27.

Note that the protruding end portion of the side guide 7 is
While extending between the calendar rolls 5, 6 below,
The side guides 7 are attached to the flange portion 26 by suitable attaching means so as to be displaceable in the lateral direction, so that the side guides 7 on both sides are formed in a lateral length of a molded product formed by the protruding end of the inner side surface. That is, the width can be changed.
It is to be noted that an appropriate structure can be adopted such that the leakage prevention member 27 is integrated with the flange portion 26 and the lateral movement of the side guide 7 is simultaneously adjusted using a screw shaft.

By driving the screw motor Mr, the extruder main body 3 kneads the rubber supplied from the rubber input port 14 and extrudes the rubber from the rubber extrusion port 4 into the closed bank under predetermined conditions. Fill the bank. In addition to the rotation of the calender roll 6 by the calender motor Mc, the calender roll 5 is also rotated and the molded article having a predetermined width is set by the side guides 7 while keeping the rubber amount in the closed bank, that is, the bank amount constant. Molds stably under given conditions. The molded product is sent out from the take-out conveyor 28, for example.

For this purpose, the roller head rubber extruder 1 employs control means C schematically shown in FIG.

The control means C includes, for example, a current sensor 30 for detecting the current of the calendar motor Mc, and a differential amplifier 32 for comparing the detected value Ic of the current sensor 30 with the set value Ia preset by the setting device 31. Equipped. A selective distribution means 40 is provided between the differential amplifier 32 and the adders 35 and 39. The adder 35
The output from the selection distribution means 40 and the calendar motor Mc
And the set value of the calendar setting device 41 for setting the steady-state rotation speed during the steady-state operation, and controls the calendar electric motor Mc via the motor controller 34. Adder 39
Is the output from the selective distribution means 40 and the screw motor Mr.
And the set value of the screw setting device 42 for setting the steady rotation speed during the steady operation of the screw motor is controlled via the motor controller 37.

The selective distribution means 40 can selectively transmit the output of the differential amplifier 32 to the adder 35 and / or the adder 39 according to a command from the command means 45. When transmitting to both, the distribution ratio of the adder 35 and the adder 39 (the ratio of increase / decrease rotational speed per time of each motor) is determined. It is preferable to distribute in the range of about 1/4 to 4/1, and more preferably in the range of about 1/2 to 2/1, and set so that the distribution ratio to the adder 39 for controlling the current of the screw motor Mr becomes large. It is good to do. When controlling only one of the calendar motor Mc and the screw motor Mr, the differential amplifier 32 and the adder 35 or the adder 39 may be directly connected, and the selective distributor 40 may be omitted.

As described above, the control device C activates the roller head rubber extruder 1 and operates the screw motor M
r, stabilizes the steady operation state of the calendar motor Mc.

FIG. 4 shows a flowchart. The current sensor 30 detects the current of the calendar motor Mc. The current of the calendar motor Mc varies the rubber resistance acting on the calender rolls 5 and 6 due to the change in the rubber pressure due to the variation of the bank amount in the closed bank, the fluctuation of the bearing resistance of the calender rolls 5 and 6 due to the rubber pressure, and the like. Varies by. Therefore, the current value of the calendar motor Mc is detected, and the detected value Ic is set by the setting device 3.
By comparing with the set value Ia at 1, the difference from the expected steady state can be obtained. In this example, hunting is prevented by setting an upper limit value Ia1 and a lower limit value Ia2 as the set value Ia, and setting a range therebetween as a dead zone. The set value Ia is set in advance according to various operating conditions.

Therefore, when the detected value Ic is larger than the set value Ia1, that is, when the bank amount is large (Ic> Ia1),
Motor controllers 34 and 37 are provided by adders 35 and 39.
, The amount of extrusion is reduced by reducing the rotation speed of the screw motor Mr, and / or the rotation speed of the calendar motor Mc is increased to increase the outflow amount from the closed bank, thereby reducing the bank amount and detecting the detected value Ic. The predetermined control is performed until the value is not larger than the set value Ia1. On the other hand, the detection value Ic is not larger than the set value Ia1 and the detection value Ic
Is smaller than the set value Ia2 (Ic <Ia2), the control is reversed. By continuously performing such control, a molded product can be stably produced.

In order to facilitate the control by making the current value and the torque substantially proportional to each other, in this embodiment, a DC motor is used as the screw motor Mr and the calendar motor Mc.

In the control method of the present invention, a twin-screw extruder body is used as the extruder main body, and the calender roll is used for molding not only a sheet-shaped molded product but also a molded product having an uneven shape, a rod shape and the like. Can be formed into various modes.

[0030]

As described above, according to the first aspect of the present invention, in a roller head rubber extruder having a closed bank, the amount of the bank in the closed bank is determined by the calender of the calendar motor including the load fluctuation, the resistance fluctuation, and the like due to the bank amount. Because the current is detected and controlled as a current, the rubber in the closed bank has a buffering action, and the sudden change in the internal pressure of the closed bank due to a change in the screw rotation speed is not detected as it is, and the inside of the closed bank is not detected. It is possible to correctly detect the pressure over the entire closed bank without being affected by the variation in the rubber pressure and to reduce the detection of unintended fluctuations as it is. Hunting can be prevented, and mechanical vibration and noise can be suppressed.

According to the second aspect of the present invention, when the detected value is larger than a set value by the feedback control, the rotational speed of the screw is reduced or the rotational speed of the calender roll is increased. Is smaller than the set value, a preferable adjustment can be made by increasing the rotation speed of the screw or decreasing the rotation speed of the calender roll.

[Brief description of the drawings]

FIG. 1 is a front view illustrating one embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view illustrating a closed bank portion;

FIG. 3 is a perspective view illustrating a side guide.

FIG. 4 is a flowchart diagram that can be employed in the method of the present invention.

[Explanation of symbols]

 2 Screw 3 Extruder main body 4 Rubber extrusion port 5, 6 Calendar roll 7 Side guide 9 Guide means Mc calendar motor Mr screw motor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29L 7:00

Claims (2)

[Claims] 1. An extruder main body having a screw for extruding rubber, disposed near a rubber outlet of the extruder main body, a lower calender roll, and a rubber extruded from the rubber extruder reaching a calender roll. A bank amount control method for a roller head rubber extruder, comprising a guide means for forming a closed bank for guiding rubber around the rubber extrusion opening, including a side guide for determining a width between the rolls, wherein the calender driving the calender roll is provided. Motor Mc
And comparing the detected value with a preset value to adjust the rotation speed of the screw or the rotation speed of the calendar roll to stabilize the bank amount. A method for controlling the bank amount of a roller head rubber extruder. 2. The method according to claim 1, wherein when the detected value of the calendar current is larger than a set value, the rotational speed of the screw is decreased or the rotational speed of the calender roll is increased, and the detected value is smaller than the set value. 2. The method according to claim 1, wherein the rotational speed of the screw is increased or the rotational speed of the calender roll is decreased.