CN101863115B - Molding control device of circular bar extruder and control method - Google Patents

Abstract

The invention discloses a molding control device of a circular bar extruder and a control method. The molding control device comprises a mouth die molding device and a process parameter control system; a gas-aid-free section mouth die of the mouth die molding device is provided with a melt parameter testing port, a mouth die gas inlet cover plate is provided with a lubricating gas flow measurement port, and a gas-aid mouth die and a gas-aid mouth die jacket are provided with lubricating gas pressure and temperature measurement ports; and the process parameter control system comprises a melt parameter control device and a lubricating gas parameter control device. The method comprises the steps of inputting a lubricating gas and implementing melt parameter control and lubricating gas parameter control. Extrusion molding is converted into an approximately full slippage non-adhesion extrusion mode from a non-slippage adhesion extrusion mode and the plastic melt is extruded in a plunger piston state in a flow passage so as to realize the reduction of extrusion pressure, save energy consumption, basically eliminate off-die expansion, improve product precision, reduce material waste, shorten the molding period and save the cost.

Description

A kind of molding control device of circular bar extruder and control method

Technical field

The present invention relates to a kind of polymer material molding process equipment, particularly a kind of molding control device of circular bar extruder and control method.

Background technology

The non-slippage adhesion of many employings sheared edge mould extrusion way during the extrusion molding of tradition circular bar, the plastic melt that is melting directly contacts with a mouthful mould internal face, increased the melt flows resistance, technological parameter adopts open-loop control system simultaneously, namely only enter molding extruder head advance trip temperature, pressure control at melt, the true melt state of molding port mould section is not monitored and is controlled, again because high viscosity, the viscoplasticity of polymer melt, so have following shortcoming during moulding:

1, be prone to extrusion swelling: extrusion swelling has increased the extrusion die design difficulty, affects the multiple tube precision;

2, the internal drop of extrusion die runner is large: make and extrude the increase of multiple tube internal stress, cause distortion to increase, also increased energy consumption simultaneously;

3, extrudate blemish: the critical extruded velocity that surpasses material owing to extruded velocity makes product surface produce " turtle skin " and extrudes the phenomenon such as break, and the appearance of extrudate surface quality defect has limited the raising of extruded velocity, affects production efficiency.

Above Three Difficult Issues have a strong impact on the goods precision, the restriction extruded velocity promotes, and cause extruding the energy consumption height.The key that solves traditional extruding-out process is reducing adhesion resistance and the control of extruding-out process parameter between mouthful mould and the melt.

Summary of the invention

The problems referred to above that exist for solving prior art, the present invention will design molding control device of circular bar extruder and the control method that a kind of formed precision is high, extruded velocity is fast, energy consumption is low.

To achieve these goals, technical scheme of the present invention is as follows:

A kind of molding control device of circular bar extruder, described extruder comprises extrusion screw rod machine, adjuster and molding control device, described molding control device comprises mouthful mold forming device and process parameter control system, described mouthful of mold forming device comprises without gas secondary segment mouth mould, mouthful mould air inlet cover plate, auxiliary mouthful of mould overcoat of gas, auxiliary mouthful of mould of gas and sealing ring, auxiliary mouthful of mould outside of described gas is equipped with auxiliary mouthful of mould overcoat of gas, and auxiliary mouthful of mould overcoat of described gas is connected with a mouthful mould air inlet cover plate by sealing ring; Described without gas secondary segment mouth mould, mouthful mould air inlet cover plate, sealing ring, the auxiliary mouth of gas mould overcoat, lubricated gas gas circuit of auxiliary mouthful of mould formation of gas, described without gas secondary segment mouth mould, the gentle auxiliary mouthful of mould formation closed air chamber of auxiliary mouthful of mould overcoat of gas; Described without radially having melt parameter testing mouth on the gas secondary segment mouth mould, have vertically lubricated gas inlet on the described mouthful of mould air inlet cover plate, as lubricated gas flow measurement mouth, the gentle auxiliary mouthful of mould overcoat of auxiliary mouthful of mould of described gas has lubricated gas pressure and temperature survey mouth vertically simultaneously;

Described process parameter control system comprises melt parameter controller and lubricated gas parameter control device, described melt parameter controller is by melt force sensor, melt temperature sensor, the melt temperature controller, the melt pressure controller, A/D converter, nerve network controller, D/A converter, described melt force sensor and melt temperature sensor are installed in respectively in the melt parameter testing mouth, by data wire successively with A/D converter, nerve network controller is connected with D/A converter, and described melt temperature controller is connected by data wire with the melt pressure controller and is connected with D/A converter; Described lubricated gas parameter control device comprises gas pressure sensor, gas temperature sensor, gas flow sensor, gas pressure regulator, gas flow controller, the gas temperature controller, A/D converter, nerve network controller, D/A converter, described gas pressure sensor and gas temperature sensor are installed in respectively in lubricated gas pressure and the temperature survey mouth, described gas flow sensor is installed in the lubricated gas flow measurement mouth, described gas pressure sensor, gas temperature sensor and gas flow sensor respectively by data wire successively with A/D converter, nerve network controller is connected with D/A converter, described gas pressure regulator, gas flow controller is connected by data wire with the gas temperature controller and is connected with D/A converter.

Nerve network controller of the present invention is the fuzzy neural network adaptive controller.

A kind of control method of molding control device of circular bar extruder may further comprise the steps:

A, by the plastic melt after the extrusion screw rod machine plasticizing, through consist of without gas secondary segment mouth mould without the gas assisted molding runner, enter the gas assisted molding runner; Simultaneously, have the lubricated gas of certain pressure via the closed air chamber of mouth mould air inlet cover plate, auxiliary mouthful of mould overcoat of gas, auxiliary mouthful of mould formation of gas, and penetrate into the gas assisted molding runner that is consisted of by auxiliary mouthful of mould of gas by auxiliary mouthful of mould of Porous gas;

B, when molten plastic melt and lubricated gas enter in the molding runners process, lubricated gas parameter control device is controlled melt parameter and lubricated gas parameter, concrete steps are as follows:

B1, melt parameter control: in without gas secondary segment mouth mould section plastic melt forming process, by the melt force sensor in the melt parameter testing mouth, melt temperature sensor detects the pressure of actual plastic melt in the current forming process, temperature feedback signal, and the temperature default with screw extruder, the pressure specification signal is made bias judge, carry out analog quantity to the conversion of digital quantity through A/D converter, then carry out digital quantity to the conversion of analog quantity with being input to D/A converter after the effect of deviation signal process nerve network controller, and the signal after will changing is input to the melt temperature controller, in the melt pressure controller, by the action of the adjuster on the extruder melt parameter is changed to the direction that reduces deviation, until deviation is zero;

B2, lubricated gas parameter control: in auxiliary mouthful of mould section of gas plastic melt forming process was arranged, a mouthful mould air inlet cover plate air inlet was equipped with gas flow sensor, the air inlet of lubricated gas flow inlet port mould air inlet cover plate behind gas flow sensor; Difference installing gas pressure sensor and gas temperature sensor in lubricated gas pressure and temperature survey mouth; Pass through gas pressure sensor, gas temperature sensor and gas flow sensor detect the pressure of lubricated gas in auxiliary mouthful of mould section of current gas, temperature and flow feedback signal, and with default temperature, pressure and flow specification signal are made bias judge, carry out analog quantity to the conversion of digital quantity through A/D converter, then with after the effect of deviation signal process nerve network controller, be input to D/A converter and carry out digital quantity to the conversion of analog quantity, and the signal after will changing is input to the gas temperature controller, gas pressure regulator and gas flow controller, by the action of the adjuster on the extruder gas parameter is changed to the direction that reduces deviation, until deviation is zero.

The network of nerve network controller of the present invention is the 5-N-1 structure, five inputs is namely arranged: be respectively melt extrusion pressure, melt temperature, gas pressure, gas flow and gas temperature; Output: die swell ratio; And comprise a hidden layer, hidden layer neuron is counted N and is drawn by following empirical equation:

$N=\sqrt{N_{\mathrm{in}}+N_{\mathrm{out}}+\mathrm{\α}}$

In the formula, N _InBe input neuron number, N _OutBe the output neuron number, α is a constant between 1 and 10, requires to determine that α is larger, and error precision is less in conjunction with different error precisions.

Compared with prior art, the present invention has following beneficial effect:

1, because the present invention is in the circular bar forming process, adopt the auxiliary die geometry of Porous gas, make to form between mouthful mould and the plastic melt and stablize air-cushion film, because the coefficient of friction of gas is extremely low, the air cushion rete drops to minimum to the frictional resistance of melt mouth mould inwall, characteristic by the ANN Control air-cushion film, make extrusion molding convert the approximate non-adhesion extrusion way of complete slippage to by non-slippage adhesion extrusion way, plastic melt is piston-shaped in runner extrudes, and has realized the reduction extrusion pressure, save energy consumption, elimination die swelling, improved the goods precision, reduced waste of material, shorten molding cycle, saved cost.

2, because the present invention is regional at gas assisted molding, auxiliary mouthful of mould of gas adopts porous material, guaranteed the uniformity of the lubricated gas in injection moulding district, strengthened the stability of air film.

3, the present invention has adopted closed loop line neural network control method to lubricated gas and plastic melt parameter in the circular bar forming process, therefore can realize the optimum process condition control under the best article quality.At first, adjust the input preset control parameters according to control target die swell ratio, such as melt pressure, temperature, lubricated gas temperature, pressure, flow etc., carry out bias judge by online detected parameters feedback and with input preset control parameters amount, drive parameter controller to the direction motion that deviation reduces, realize closed-loop control.Secondly, owing to adopted neural network control method, can make the vibration of system under external interference carry out better damping coupling, and different operating modes are kept the control effect of stable and consistent, embody very strong robustness.

Description of drawings

4 in the total accompanying drawing of the present invention, wherein:

Fig. 1 is the process parameter control system schematic of molding control device of circular bar extruder.

Fig. 2 is the mouth mold forming apparatus structure schematic diagram of molding control device of circular bar extruder.

Fig. 3 is melt parameter controller schematic diagram.

Fig. 4 is lubricated gas parameter control device schematic diagram.

Among the figure, 1, melt parameter testing mouth, 2, the melt temperature controller, 3, the melt pressure controller, 4, melt temperature sensor, 5, melt force sensor, 6, gas flow sensor, 7, gas temperature sensor, 8, gas pressure sensor, 9, gas flow controller, 10, the gas temperature controller, 11, gas pressure regulator, 12, A/D converter, 13, nerve network controller, 14, D/A converter, 15, lubricated gas pressure and temperature survey mouth, 16, without gas secondary segment mouth mould, 17, closed air chamber, 18, auxiliary mouthful of mould overcoat of gas, 19, sealing ring, 20, mouth mould air inlet cover plate, 21, auxiliary mouthful of mould of gas.

The specific embodiment

The below is described further the present invention with reference to the accompanying drawings.Shown in Fig. 1-4, a kind of molding control device of circular bar extruder, described extruder comprises extrusion screw rod machine, adjuster and molding control device, described molding control device comprises mouthful mold forming device and process parameter control system, described mouthful of mold forming device comprises without gas secondary segment mouth mould 16, mouthful mould air inlet cover plate 20, auxiliary mouthful of mould overcoat 18 of gas, auxiliary mouthful of mould 21 of gas and sealing ring 19, auxiliary mouthful of mould 21 outsides of described gas are equipped with auxiliary mouthful of mould overcoat 18 of gas, and auxiliary mouthful of mould overcoat 18 of described gas is connected with a mouthful mould air inlet cover plate 20 by sealing ring 19; Described without gas secondary segment mouth mould 16, mouthful mould air inlet cover plate 20, sealing ring 19, the auxiliary mouth of gas mould overcoat 18, lubricated gas gas circuit of auxiliary mouthful of mould of gas 21 formations, described without gas secondary segment mouth mould 16, auxiliary mouthful of mould overcoat of gas 18 gentle auxiliary mouthful of moulds 21 formation closed air chambers 17; Described without radially having melt parameter testing mouth 1 on the gas secondary segment mouth mould 16, have vertically lubricated gas inlet on the described mouthful of mould air inlet cover plate 20, as lubricated gas flow measurement mouth, auxiliary mouthful of mould of described gas 21 gentle auxiliary mouthful of mould overcoats 18 have lubricated gas pressure and temperature survey mouth 15 vertically simultaneously; Described process parameter control system comprises melt parameter controller and lubricated gas parameter control device, described melt parameter controller is by melt force sensor 5, melt temperature sensor 4, melt temperature controller 2, melt pressure controller 3, A/D converter 12, nerve network controller 13, D/A converter 14, described melt force sensor 5 and melt temperature sensor 4 are installed in respectively in the melt parameter testing mouth 1, by data wire successively with A/D converter 12, nerve network controller 13 is connected connection with D/A converter, described melt temperature controller 2 is connected with the melt pressure controller and is connected with D/A converter 14 by data wire respectively; Described lubricated gas parameter control device comprises gas pressure sensor 8, gas temperature sensor 7, gas flow sensor 6, gas pressure regulator 11, gas flow controller 9, gas temperature controller 10, A/D converter 12, nerve network controller 13, D/A converter 14, described gas pressure sensor 8 and gas temperature sensor 7 are installed in respectively in lubricated gas pressure and the temperature survey mouth 15, described gas flow sensor 6 is installed in the lubricated gas flow measurement mouth, described gas pressure sensor 8, gas temperature sensor 7 and gas flow sensor 6 respectively by data wire successively with A/D converter 12, nerve network controller 13 is connected connection with D/A converter, described gas pressure regulator 11, gas flow controller 9 is connected with the gas temperature controller and is connected with D/A converter 14 by data wire respectively.Described nerve network controller 13 is fuzzy neural network adaptive controllers.

A kind of control method of molding control device of circular bar extruder may further comprise the steps:

A, by the plastic melt after the extrusion screw rod machine plasticizing, through consist of without gas secondary segment mouth mould 16 without the gas assisted molding runner, enter the gas assisted molding runner; Simultaneously, have the lubricated gas of certain pressure via the closed air chamber 17 of mouth mould air inlet cover plate 20, auxiliary mouthful of mould overcoat 18 of gas, auxiliary mouthful of mould 21 formations of gas, and penetrate into the gas assisted molding runner that is consisted of by auxiliary mouthful of mould 21 of gas by auxiliary mouthful of mould 21 of Porous gas;

B, when molten plastic melt and lubricated gas enter in the molding runners process, lubricated gas parameter control device is controlled melt parameter and lubricated gas parameter, concrete steps are as follows:

B1, melt parameter control: in without 16 sections plastic melt forming processes of gas secondary segment mouth mould, by the melt force sensor 5 in the melt parameter testing mouth 1, melt temperature sensor 4 detects the pressure of actual plastic melt in the current forming process, temperature feedback signal, and the temperature default with screw extruder, the pressure specification signal is made bias judge, carry out analog quantity to the conversion of digital quantity through A/D converter 12, then be input to D/A converter 14 after deviation signal being acted on through nerve network controller 13 and carry out digital quantity to the conversion of analog quantity, and the signal after will changing is input to melt temperature controller 2, in the melt pressure controller 3, by the action of the adjuster on the extruder melt parameter is changed to the direction that reduces deviation, until deviation is zero;

B2, lubricated gas parameter control: in 21 sections plastic melt forming processes of auxiliary mouthful of mould of gas were arranged, mouthful mould air inlet cover plate 20 air inlets were equipped with gas flow sensor 6, the air inlet of lubricated gas flow inlet port mould air inlet cover plate 20 behind gas flow sensor 6; At lubricated gas pressure and temperature survey mouth 15 interior respectively installing gas pressure sensor 8 and gas temperature sensors 7; By gas pressure sensor 8, gas temperature sensor 7 and gas flow sensor 6 detects the pressure of lubricated gas in 21 sections of auxiliary mouthful of moulds of current gas, temperature and flow feedback signal, and with default temperature, pressure and flow specification signal are made bias judge, carry out analog quantity to the conversion of digital quantity through A/D converter 12, then after deviation signal being acted on through nerve network controller 13, be input to D/A converter 14 and carry out digital quantity to the conversion of analog quantity, and the signal after will changing is input to gas temperature controller 10, gas pressure regulator 11 and gas flow controller 9, by the action of the adjuster on the extruder gas parameter is changed to the direction that reduces deviation, until deviation is zero.

The network of nerve network controller 13 of the present invention is the 5-N-1 structure, five inputs is namely arranged: be respectively melt extrusion pressure, melt temperature, gas pressure, gas flow and gas temperature; Output: die swell ratio; And comprise a hidden layer, hidden layer neuron is counted N and is drawn by following empirical equation:

$N=\sqrt{N_{\mathrm{in}}+N_{\mathrm{out}}+\mathrm{\α}}$

In the formula, N _InBe input neuron number, N _OutBe the output neuron number, α is a constant between 1 and 10, requires to determine that α is larger, and error precision is less in conjunction with different error precisions.

Claims (4)

1. molding control device of circular bar extruder, described extruder comprises the extrusion screw rod machine, adjuster and molding control device, it is characterized in that: described molding control device comprises mouthful mold forming device and process parameter control system, described mouthful of mold forming device comprises without gas secondary segment mouth mould (16), mouth mould air inlet cover plate (20), auxiliary mouthful of mould overcoat (18) of gas, auxiliary mouthful of mould (21) of gas and sealing ring (19), auxiliary mouthful of mould of described gas (21) outside is equipped with auxiliary mouthful of mould overcoat (18) of gas, and auxiliary mouthful of mould overcoat of described gas (18) is connected with a mouthful mould air inlet cover plate (20) by sealing ring (19); Described without gas secondary segment mouth mould (16), mouthful mould air inlet cover plate (20), sealing ring (19), the auxiliary mouth of gas mould overcoat (18), lubricated gas gas circuit of auxiliary mouthful of mould of gas (21) formation, described without gas secondary segment mouth mould (16), the gentle auxiliary mouthful of mould of auxiliary mouthful of mould overcoat of gas (18) (21) formation closed air chamber (17); Described without radially having melt parameter testing mouth (1) on the gas secondary segment mouth mould (16), have vertically lubricated gas inlet on the described mouthful of mould air inlet cover plate (20), as lubricated gas flow measurement mouth, the gentle auxiliary mouthful of mould overcoat of auxiliary mouthful of mould of described gas (21) (18) has lubricated gas pressure and temperature survey mouth (15) vertically simultaneously; Described process parameter control system comprises melt parameter controller and lubricated gas parameter control device, described melt parameter controller is by melt force sensor (5), melt temperature sensor (4), melt temperature controller (2), melt pressure controller (3), A/D converter (12), nerve network controller (13), D/A converter (14), described melt force sensor (5) and melt temperature sensor (4) are installed in respectively in the melt parameter testing mouth (1), by data wire successively with A/D converter (12), nerve network controller (13) is connected 14 with D/A converter) connect, described melt temperature controller (2) is connected 3 with the melt pressure controller) be connected with D/A converter (14) by data wire respectively; Described lubricated gas parameter control device comprises gas pressure sensor (8), gas temperature sensor (7), gas flow sensor (6), gas pressure regulator (11), gas flow controller (9), gas temperature controller (10), A/D converter (12), nerve network controller (13), D/A converter (14), described gas pressure sensor (8) and gas temperature sensor (7) are installed in respectively in lubricated gas pressure and the temperature survey mouth (15), described gas flow sensor (6) is installed in the lubricated gas flow measurement mouth, described gas pressure sensor (8), gas temperature sensor (7) and gas flow sensor (6) respectively by data wire successively with A/D converter (12), nerve network controller (13) is connected 14 with D/A converter) connect described gas pressure regulator (11), gas flow controller (9) is connected 10 with the gas temperature controller) be connected with D/A converter (14) by data wire respectively.

2. a kind of molding control device of circular bar extruder according to claim 1, it is characterized in that: described nerve network controller (13) is the fuzzy neural network adaptive controller.

3. the control method of a molding control device of circular bar extruder is characterized in that: may further comprise the steps:

A, by the plastic melt after the extrusion screw rod machine plasticizing, through consist of without gas secondary segment mouth mould (16) without the gas assisted molding runner, enter the gas assisted molding runner; Simultaneously, have the lubricated gas of certain pressure via the closed air chamber (17) of mouth mould air inlet cover plate (20), auxiliary mouthful of mould overcoat (18) of gas, auxiliary mouthful of mould of gas (21) formation, and penetrate into the gas assisted molding runner that is consisted of by auxiliary mouthful of mould of gas (21) by auxiliary mouthful of mould of Porous gas (21);

B, when molten plastic melt and lubricated gas enter in the molding runners process, lubricated gas parameter control device is controlled melt parameter and lubricated gas parameter, concrete steps are as follows:

B1, melt parameter control: in without gas secondary segment mouth mould (16) section plastic melt forming process, by the melt force sensor (5) in the melt parameter testing mouth (1), melt temperature sensor (4) detects the pressure of actual plastic melt in the current forming process, temperature feedback signal, and the temperature default with screw extruder, the pressure specification signal is made bias judge, carry out analog quantity to the conversion of digital quantity through A/D converter (12), then be input to D/A converter (14) after deviation signal being acted on through nerve network controller (13) and carry out digital quantity to the conversion of analog quantity, and the signal after will changing is input to melt temperature controller (2), in the melt pressure controller (3), by the action of the adjuster on the extruder melt parameter is changed to the direction that reduces deviation, until deviation is zero;

B2, lubricated gas parameter control: in auxiliary mouthful of mould of gas (21) section plastic melt forming process is arranged, mouth mould air inlet cover plate (20) air inlet is equipped with gas flow sensor (6), the air inlet of lubricated gas flow inlet port mould air inlet cover plate (20) behind gas flow sensor (6); Difference installing gas pressure sensor (8) and gas temperature sensor (7) in lubricated gas pressure and temperature survey mouth (15); By gas pressure sensor (8), gas temperature sensor (7) and gas flow sensor (6) detect the pressure of lubricated gas in auxiliary mouthful of mould of current gas (21) section, temperature and flow feedback signal, and with default temperature, pressure and flow specification signal are made bias judge, carry out analog quantity to the conversion of digital quantity through A/D converter (12), then after deviation signal being acted on through nerve network controller (13), be input to D/A converter (14) and carry out digital quantity to the conversion of analog quantity, and the signal after will changing is input to gas temperature controller (10), gas pressure regulator (11) and gas flow controller (9), by the action of the adjuster on the extruder gas parameter is changed to the direction that reduces deviation, until deviation is zero.

4. the control method of a kind of molding control device of circular bar extruder according to claim 3, it is characterized in that: the network of described nerve network controller (13) is the 5-N-1 structure, five inputs is namely arranged: be respectively melt extrusion pressure, melt temperature, gas pressure, gas flow and gas temperature; Output: die swell ratio; And comprise a hidden layer, hidden layer neuron is counted N and is drawn by following empirical equation:

$N=\sqrt{N_{\mathrm{in}}+N_{\mathrm{out}}+\mathrm{\α}}$

In the formula, N _InBe input neuron number, N _OutBe the output neuron number, α is a constant between 1 and 10, requires to determine that α is larger, and error precision is less in conjunction with different error precisions.

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