JP4440044B2 - Temperature control method for hot air dryer and hot air dryer - Google Patents

Description

  The present invention relates to a temperature control method for a hot air drying device for drying wet warp yarns and the hot air drying device.

  For example, the one described in Patent Document 1 is known as one of hot air drying apparatuses that are used in a warp glue sizing machine that glues sheet-like warp yarns and winds them around a beam. . The hot air drying apparatus described in Patent Document 1 includes a drying chamber, a temperature detector that detects the temperature inside the drying chamber as a drying chamber temperature, a blower that sends air into the drying chamber, and air that is fed into the drying chamber. To heat the air by the air heater based on the deviation between the air heater arranged in the air blowing path, the setting device for setting the target temperature inside the drying chamber, and the target temperature of the drying chamber temperature And a temperature controller for controlling the amount.

  Further, in the hot air drying device, in order to increase the control accuracy of the internal temperature of the drying chamber, as a temperature controller in recent years, for example, the deviation of the detected internal temperature from the target temperature and predetermined constants of proportionality, integral and derivative are set. Based on the PID calculation, the one that adjusts the opening / closing time of the control valve that controls the air heating amount based on the PID calculation result is used. Such a hot air dryer maintains a constant temperature inside the drying chamber based on one PID constant.

Japanese Patent Laid-Open No. 9-209258, FIG.

  However, the set temperature (target temperature) in the drying chamber in the hot air drying apparatus is frequently changed in accordance with the change in the conditions of the warp sizing machine such as the type of warp and the running speed of the warp. However, there has not been a technique for selectively using a PID constant that is a basis of PID calculation in the temperature control in the drying chamber corresponding to the target temperature. When the same PID constant is used regardless of the target temperature as in the prior art, the internal temperature of the drying chamber of the hot air drying device causes a delay in hunting or settling due to the set target temperature. As a result, the accuracy of temperature control is deteriorated, and the warp dryness is uneven, resulting in a decrease in the quality of the warp beam.

  The object of the present invention is to always maintain the internal temperature of the drying chamber with high accuracy even if the target temperature is changed in accordance with the change in the conditions of the warp sizing machine such as the type of warp and the feed speed of the wet warp. There is to keep on.

Temperature control method according to the present invention is applied to a hot-air drying apparatus for Drying by passing the wet warp the drying chamber. The temperature control method is used in a hot air drying device that passes a wet warp through a drying chamber and dries it. During operation of the hot air drying device, based on the deviation of the detected internal temperature of the drying chamber from the set target temperature, The present invention is applied to a hot air drying apparatus that performs PID calculation with a temperature controller and controls the amount of heating of the air that is fed in according to the PID calculation result with an air superheater . Temperature control method of the hot air drying apparatus, the one-way also less of integration constant and differential constant used in the PID calculation and the proportionality constant, advance to correspond to pre Symbol憶to each of the plurality of target temperatures, When the target temperature is set, and select the constant number that corresponds to how we set the target temperature in the stored plurality of constant output PID constants including the selected constant to the temperature controller and, during operation of the hot-air drying apparatus,-out based on the PID constant output as the deviation, temperature controller, together executes PID calculation, air superheater heat control signal according to a result of the PID calculation Output to

A hot air drying apparatus according to the present invention includes a drying chamber that passes wet warp to dry, a temperature detector that detects an internal temperature of the drying chamber, a blower that sends air into the drying chamber, and a heat amount control signal. An air heater for heating the air fed into the drying chamber according to the above, a setter for setting the target temperature inside the drying chamber, and a PID constant and the detected internal temperature of the drying chamber for the set target temperature and a temperature controller for outputting a heat quantity control signal according to the PID calculation result based on the deviation a including the heat-air drying apparatus, the hot air drying apparatus further includes a low without the hand also the integration constant and differential constant a proportionality constant, allowed to advance more stored in correspondence to each of the plurality of target temperatures, and select the constant corresponding to the set target temperature, the temperature control of the PID constants including the selected constant Includes a PID constant output unit for outputting, during operation, the temperature controller, to the deviation of the set target temperature of the internal temperature of the drying chamber it is detected that the outputted PID constants from the PID constant output device a heat control signal according to the PID calculation result based you output to the air superheater.

  Further, the temperature controller outputs a predetermined heat amount control signal for a target temperature to the air heater in response to the input of the tuning command signal, and calculates each constant from the detected change in the drying chamber temperature during this time. It has a tuning function. The PID constant output unit may store the PID constant obtained by the tuning function in correspondence with the target temperature.

  According to the temperature control method and hot air drying apparatus of the present invention, even if the target temperature setting value is changed, a PID constant suitable for the changed target temperature setting value is automatically selected. Regardless of whether the target temperature is high or low, it is possible to prevent temperature control hunting or settling delay caused by using the same PID constant, and the hot air temperature can always be kept at the changed target temperature.

  According to a more preferable hot air drying apparatus, since the storage unit stores each constant obtained by executing the tuning function in response to the input of the tuning command signal, the storage unit stores the constant corresponding to the target temperature. The constant is a suitable constant, and the accuracy of temperature control is further increased.

  Referring to FIG. 1, a hot air drying device 10 such as a warp gluing machine performs drying in which hot air is blown through a plurality of wet warp yarns 12 which are arranged in a sheet shape and glued in a previous process (not shown). Pass through the room and dry. Thereafter, the warp yarn 12 is fed into a cylinder drying section (not shown) and further dried in a subsequent process.

  The hot-air drying apparatus 10 is roughly composed of a drying chamber 14, a blower 20 disposed in an air blowing path 18 that sends air into the drying chamber 14, and an air heater disposed to heat the air supplied to the blower 20. 22.

  The drying chamber 14 has a rectangular shape in cross section, and has a cylindrical shape in which openings 24 and 26 are provided on one side and the other side. A hot air blowing port 28 and a hot air exhaust port 30 are provided near one end and the other end in the longitudinal direction of the drying chamber 14.

  A temperature detector 16 is disposed inside the drying chamber 14 between the hot air inlet 28 and the hot air outlet 30. The temperature detector 16 is a known temperature sensor such as a thermocouple.

  The air blowing path 18 is a path for sending air from the hot air exhaust port 30 to the hot air blowing port 28. More specifically, the air blowing path 18 roughly includes a duct 18 a that connects the hot air exhaust port 30 of the drying chamber 14 and the introduction portion of the air superheater 22, a lead-out portion of the air superheater 22, and an intake port of the blower 20. And a duct 18c connected to the outlet of the air superheater 22 and the hot air inlet 28 of the drying chamber 14, and heats the air from the drying chamber 14 via the air superheater 22. In addition, an air circulation path that returns to the drying chamber 14 by the blower 20 is configured. In the air blowing path 18, an air heater 22 and a blower 20 are arranged in series.

  A hot air exhaust port 31 for exhaust is provided in the vicinity of the hot air exhaust port 30 for circulating hot air, and an exhaust duct 36 and an exhaust machine 32 are disposed with respect to the hot air exhaust port 31. The exhaust machine 32 includes an exhaust fan 34 and an exhaust motor 35 that rotates the exhaust fan 34. The air sucked from the hot air exhaust port 31 is discharged from the opening 38 of the exhaust fan 34 to the outside of the hot air drying device 10 through the exhaust duct 36.

  The air heater 22 includes a heat source (not shown) that generates water vapor, a control valve 40 that adjusts the steam supplied from the heat source, and a radiator 42 that dissipates the heat of the supplied steam. It is connected airtight through. However, the air heater 22 may include an electric heater that generates heat according to a temperature control command signal, which will be described later, or a gas heater that generates heat according to the amount of combustion of the fuel gas. Good.

  The control valve 40 that adjusts the steam supply amount is, for example, an on-off valve. The on-off valve is fully opened or closed by an on or off signal output from a temperature controller 52 described later. However, the regulating valve 40 may be a throttle valve, and the throttle amount may be controlled based on a signal output from the temperature controller 52.

  The blower 20 takes in the heated air by passing the air from the hot air exhaust port 30 through the air heater 22 by setting the intake port to a negative pressure state by the operation of the blower 20, and its blowout port. Further, the heated air is sent into the hot air inlet 28.

  The blower 20 includes a blower motor 46 and a blower fan 48 that is rotated by rotation of the output shaft of the blower motor 46. The blower motor 46 is controlled by a main controller 50 described later.

  The air heated by the air heater 22 flows through the inside of the drying chamber 14 from the hot air inlet 28 to the hot air outlet 30 via the fan 20 mainly by the suction force of the fan 20.

  The plurality of warps 12 pass through the inside of the drying chamber 14 from one opening 24 of the drying chamber 14 toward the other opening 26 in a wet state. The plurality of warps 12 located inside the drying chamber 14 are dried by the heated air flowing inside the drying chamber 14. The moving direction of the plurality of warps 12 inside the drying chamber 14 is preferably opposite to the moving direction of the heated air flowing inside the drying chamber 14.

  FIG. 2 shows a control block diagram of the hot air drying apparatus 10. The hot air drying apparatus 10 generally includes a main controller 50, a temperature controller 52, and a setting device 66.

  The main controller 50 receives signals from the operation button 54, the heat button 56, the stop button 58 and the automatic tuning operation button 60 operated by the operator. The operation button 54, the heat button 56, the stop button 58, and the automatic tuning operation button 60 function as an operation controller.

  The main controller 50 is composed of a known controller such as a programmable controller. The main controller 50 includes a drying control unit 62, a control unit of a warp gluing machine (not shown), for example, a winding control unit 64, and a tension control unit (not shown) that controls the warp tension. The main controller 50 can output the temperature control command signal S3 and the automatic tuning command signal S7 to the temperature controller 52 by pressing each button as follows.

  In addition, it is also possible to process with well-known controllers, such as a programmable controller, which integrated each loom such as the main controller 50, the drying controller 62, the winding controller 64, and the tension controller.

  When the operator presses the operation button 54 or the heat button 56, the operation signal S1 or the heat signal S2 is input to the main controller 50. Thereby, the main controller 50 outputs an operation command signal to the corresponding current generator, and puts the blower 20 into an operating state. The main controller 50 also outputs a temperature control command signal S3 to the temperature controller 52. As will be described in detail later, the temperature controller 52 starts temperature control for controlling the amount of heat to heat the circulating air so that the drying chamber 14 reaches a predetermined target temperature. Thus, the operation of the hot air drying device 10 is started.

  The heat button 56 is a button that is operated in advance when the internal temperature of the drying chamber is lowered prior to the start of operation by pressing the operation button 54, and more specifically, the temperature of the drying chamber 14 is set in advance. It is operated to prevent drying unevenness immediately after the start of operation by raising the temperature to a desired target temperature.

  Accordingly, when the operation button 54 is pressed, the main controller 50 outputs an operation signal S1, and any of the pasting control units (not shown) such as the winding control unit 64 and the tension control unit (not shown). Put into operation. As a result, the specific configuration of the warp gluing machine is not shown below, but the wet warp on the sheet drawn out from the delivery beam and immersed in the glue solution is squeezed in the drying chamber 14 and further in the next step. The warp yarn 12 is dried through a certain cylinder drying section, and the warp yarn 12 is run while maintaining a predetermined warp yarn tension, and is eventually wound around the warp beam.

  The exhaust device 32 is provided for the purpose of discharging moisture in the drying chamber by discharging a part of the circulating air during operation of the warp gluing machine, and enhancing the drying effect. Are appropriately activated in accordance with the operation status of the warp glue machine under an algorithm not described in detail.

  When a stop cause occurs during the operation of the warp gluing machine or when the operator presses the stop button 58 and the stop signal S4 is input to the main controller 50, the main controller 50 The glueing machine (not shown) is immediately stopped, and the blower 20 and the exhaust machine 32 are deactivated. Further, the main controller 50 outputs an off temperature control command signal S3 to the temperature controller 52, and immediately suspends the execution of the temperature control.

  The temperature control of the temperature controller 52 will be described in detail later. At the time of delivery and installation of the warp gluing machine, an operator of the warp gluing machine manufacturer (manufacturer) makes a control gain (more than Specifically, the PID constant) is determined to an appropriate value. In contrast, warp preparation factories with warp sizing machines often renew facilities such as steam boilers, which are used as heat sources, and relocate the warp sizing machines to different locations in different seasons or different altitudes. . Such a change in the surrounding environment may change the control gain for the temperature control system. In other words, as a result of the previously determined control gain becoming a value that is not suitable for changes in the surrounding environment, there is a risk that the functionality of temperature regulation is impaired.

  For this reason, in the temperature controller 52 of the hot air drying apparatus 10 as the present apparatus, the operator operates a tuning operation button to execute predetermined heat control instead of executing the normal temperature control function. A tuning function for automatically determining a PID constant that is a control gain is configured to be selectively executed.

  More specifically, in response to such changes in the surrounding environment, the operator of the warp preparation factory depresses the tuning operation button 60, so that the main controller 50 determines the operating state of the blower 20. The tuning command S7 is output to the temperature controller 52.

  The automatic tuning needs to be performed under the condition that the blower 20 is in operation, and should be performed after the heat button 56 is pressed or during operation of the gluing machine.

  Therefore, the operator presses the heat button 56 prior to the start of the operation of the gluing machine, and the main controller 50 that has received the heat signal S2 operates the hot air drying device 10. The heat button 56 is operated while the gluing machine is stopped.

  By preliminarily circulating the heated air by the air heater 22 through the air blowing path 18 and the drying chamber 14 and maintaining a predetermined temperature, the glued warp 12 immediately after the start of the operation of the gluing machine. Prevent poor drying.

  The setting device 66 is configured by a touch panel or the like that has both functions of an input device and a display device for the seed controller 50 and the temperature controller 52. The setter 66, the main controller 50, and the temperature controller 52 are connected so that information can be transmitted and received in both directions.

  The setting device 66 stores a program created in advance by the manufacturer of the hot air drying apparatus 10, and the setting device 66 switches the display of the screen of the display device and the input device (not shown) by an operation performed by the operator. The setting value input by the touch operation performed by the operator is output to the main controller 50. Further, the setting device 66 reads information (for example, stop information, winding length control information) held by the main controller 50 and displays it on the screen of a display device (not shown) of the setting device 66.

  The operator switches the screen of the setting device 66 to another screen in an interactive manner with the worker to display information, and inputs the target temperature T inside the drying chamber 14. The setter 66 outputs the input target temperature T to the temperature controller 52. The setter 66 also functions as a PID constant output device that outputs a PID constant corresponding to the target temperature T to the temperature controller 52, details of which will be described later.

  The setting device 66 may display the temperature inside the drying chamber 14 detected by the temperature detector 16 as the drying chamber temperature. The setting device 66 records the detected drying chamber temperature over time according to the operation of the operator, and outputs the recorded drying chamber temperature to the display screen over time with the horizontal axis as the time axis. It may be.

  The temperature controller 52 calculates a deviation of the drying room temperature To from the target temperature T, performs a PID calculation based on the calculated deviation, and calculates the amount of air heated by the air heater 22 based on the result of the PID calculation. Outputs a heat control signal for control. In the PID calculation, the sum of the operation amounts of the proportional element (P operation), the integral element (I operation), and the differential element (D operation) is output as an operation amount.

  The proportionality constant (P constant) on which the proportional element (P operation) is based is determined in the form of a proportional band. Here, the proportional band refers to a region in which an operation amount proportional to the deviation is output, and is a width α centered on the set value of the target temperature T.

  When the measured temperature To in the drying chamber is equal to or lower than the starting point of the proportional band (that is, To ≦ T−α / 2), the output of the manipulated variable is fixed to 100%, and conversely, is equal to or higher than the end point of the proportional band (that is, To ≧ In the case of T + α / 2), the output of the manipulated variable is fixed at 0%.

  The manipulated variable ranges from 100% to 0% depending on the deviation from the target temperature T when the measured temperature To is from the start point to the end point of the proportional band (ie, T−α / 2 <To <T + α / 2). Is output. The smaller the proportional band width, the greater the manipulated variable with respect to the deviation amount.

  The integration constant (I constant) that is the basis of the integration element (I operation) is determined in the form of integration time. Here, the integration time is a time required for the integration operation amount to reach the same operation amount as the operation amount by the proportional operation when a step-like deviation is input.

  The shorter the integration time, the larger the change amount of the manipulated variable with respect to the deviation amount with time.

  The differential constant (D constant) that is the basis of the differential element (D operation) is determined in the form of differential time. Here, the derivative time is defined as the time required for the differential manipulated variable to reach the same manipulated variable as the proportional manipulated variable when a ramp ramp-shaped deviation whose deviation is increased at a constant rate over time is input. The

  The longer the derivative time, the greater the manipulated variable with respect to the deviation amount change.

  In this way, the PID calculator is used as a control signal for the amount of heating of air corresponding to the sum of the manipulated variables in each element of the proportional element (P action), the integral element (I action), and the derivative element (D action). An operation amount signal to the open / close valve 40 can be output. For example, when the on-off valve 40 connected to this via a current generator is a so-called ON / OFF-controlled on-off valve, the ratio between the predetermined unit period and the on-off valve 40 opened state However, an open / close command signal that provides an open / close ratio (duty ratio) corresponding to the operation amount by the sum of the above elements is output as a control signal for the amount of heating of air.

  By the operation of the heat button 56 by the operator, the temperature controller 52 opens and closes the on-off valve 40 according to the calculated operation amount so that the temperature inside the drying chamber 14 becomes the target temperature T, and the air The air flowing inside the heater 22 is heated.

  Preferably, the main controller 50 until the temperature inside the drying chamber 14 reaches within a few percent of the target temperature T (for example, when the target temperature T is 80 ° C., the range is 73 ° C. to 78 ° C.). The operation signal S1 from the operation button 54 is invalidated. When the temperature inside the drying chamber 14 reaches within a few percent of the target temperature T, the main controller 50 outputs an operation signal to the winding control unit 64 or the like according to the operation signal S1 from the operation button 54, The warp sizing machine is operated to dry the supplied wet warp 12.

  Thereby, the quality defect of the warp beam due to the drying failure that the warp yarn 12 is dried in a state where the temperature inside the drying chamber 14 is lower than the target temperature T can be prevented.

  FIG. 3 shows a series of processing flows when the temperature controller 52 calculates PID constants corresponding to each of the high temperature region, the medium temperature region, and the low temperature region.

  For example, when the operator sequentially selects and displays a menu for entering the automatic tuning mode with respect to the menu displayed on the touch panel of the setting device 66, the setting device 66 performs main control on the information to that effect. The main controller 50 switches to the automatic tuning mode (ST101).

  In the tuning mode, the main controller 50 prohibits the operation of the warp gluing machine, calculates the PID constant for the target temperature using the tuning function of the temperature controller 52, and calculates the obtained PID constant. A series of processes for storing in the setter 66 for each target temperature can be executed. In the embodiment described below, an assumed set target temperature region is divided into three regions, a low temperature region, a medium temperature region, and a high temperature region, and each reference temperature serving as a target temperature representing each region is used. It is an example which calculates the PID constant with respect to a temperature range.

  First, the operator inputs the reference temperature in the low temperature region to the setter 66 as the set value of the target temperature (ST102).

  Next, the operator performs a tuning operation. The tuning operation is performed by pressing the heat button 56 and the tuning operation button 60 (ST103).

  More specifically, the set value of the target temperature previously input to the setter 66 is sent to the temperature controller 52 as the target temperature.

  Therefore, when the operation signal from the heat button is turned on, the main controller 50 immediately turns on the blower blower as the blower 22, while the temperature controller 52 immediately switches the temperature control mode to “temperature control OFF mode”. Is switched to the “temperature control ON mode” and an operation amount signal (not shown) is output to the air heater 22, so that the internal temperature of the drying chamber detected via the temperature sensor 16 is directed from the room temperature to the target temperature T. Rise rapidly.

  Next, when the operator operates the tuning operation button and generates a tuning operation signal when the room temperature in the drying chamber rises to some extent, the temperature controller 52 switches the control mode to the “automatic tuning mode”.

  Operation in Automatic Tuning Mode The so-called automatic tuning operation starts from a state where the actual room temperature To is slightly lower than the target temperature T, for example. More specifically, by performing temperature control that fully opens the on-off valve 40 until the internal temperature To of the actual drying chamber reaches the target temperature T, and then fully closes the on-off valve until it falls below the target temperature T, While the temperature in the drying chamber is hunted, the temperature fluctuation width W1 in the hunting, the time Td1 until the measured temperature To reaches the maximum value after the on-off valve 40 is fully closed by the temperature control, and the measured temperature To The time T1 until the measured temperature To starts to rise in a state where the temperature is below the target temperature T and the on-off valve 40 is fully opened is measured, and each data obtained by repeating such hunting operation about twice. Based on the above, a PID constant is calculated and automatically determined.

  When such an automatic tuning operation is completed, the temperature controller 52 switches the temperature control mode to the “temperature control OFF mode” and outputs a signal (not shown) to the main controller 50 and the setting unit 66. For this reason, the main controller 50 immediately turns off the blower blower as the blower 22, while the setter 66 reads out the calculated PID constant from the temperature controller 52, and the PID corresponding to the temperature region to which the target temperature belongs. The constant is stored in a built-in memory (not shown) (ST104).

  When the storage process is finished, the setter 66 displays a display on the touch panel prompting the user to input whether or not to finish the tuning process of the PID constant for another temperature range (ST105). Since the operator needs to calculate PID constants for other temperature regions such as the intermediate temperature region, the operator returns to the processing step ST102 by inputting selection information indicating that the operation is continued to the setting device 66. Thereafter, the reference temperature for the intermediate temperature region and the high temperature region is set as the target temperature, and the PID constant for each temperature region is calculated by pressing the heat button and the tuning operation button in this order, and is not shown in the setting device 66. It is stored in the memory as a PID constant corresponding to the target temperature. In this way, PID constants corresponding to each of the high temperature region, the medium temperature region, and the low temperature region are obtained in a one-to-one manner, and the obtained PID constants together with the reference temperature are stored in the setting device 66 (not shown). Remember me.

  Then, after calculating the PID constants for the high temperature region, the medium temperature region, and the low temperature region, the operator ends the automatic tuning mode by a selection operation to “end work” in response to the above-described display in the processing step ST105. (ST106).

  Table 1 shows the PID constants thus obtained. The setter 66 has a PID constant corresponding to each of the high temperature region, the intermediate temperature region, and the low temperature region obtained in this manner.

  Prior to the operation of the warp gluing machine, the stored PID constants are output from the setter 66 to the temperature controller 52 together with the target temperature information, the PID constant corresponding to the input target temperature T.

  FIG. 4 shows an internal processing flow of the setting unit 66 for changing the PID constant when the operator changes the warp type.

  First, when the operator changes the warp type, a new set value of the target temperature Ts is input to the setter 66 almost simultaneously (ST201). The setter 66 to which the new target temperature Ts is input determines whether the input set value of the target temperature T belongs to a low temperature region, a medium temperature region, or a high temperature region (ST202).

  When the setting device 66 determines that the target temperature Ts falls within the low temperature region, the setting device 66 reads out from the low temperature PID constant and a storage device (not shown) incorporated therein and outputs it to the temperature controller 52 (ST203).

  If the setting device 66 determines that the target temperature Ts falls within the intermediate temperature region, the setting device 66 reads out the intermediate temperature PID constant from a storage device (not shown) incorporated therein, and outputs it to the temperature controller 52 (ST204). ).

  If the setting device 66 determines that the target temperature Ts falls within the high temperature region, the setting device 66 reads a PID constant for high temperature from a storage device (not shown) built therein, and outputs it to the temperature controller 52 (ST205).

  As described above, even if the set value of the target temperature T is changed in accordance with the change of the warp beam types produced by the operator, the setter 66 automatically selects a PID constant suitable for the changed set value Ts. Since the temperature is output to the temperature controller 52, the hot air temperature can always be kept at the changed target temperature Ts.

  The control block diagram of the hot air drying apparatus 10 shown in FIG. 5 is an embodiment in which a temperature controller 52a having no automatic tuning function is used instead of the temperature controller 52 shown in the first embodiment (FIG. 2).

  The setting device 66 is connected to a storage device 68 provided separately to store a database relating to PID constants, and the storage device 68 and the setting device 66 constitute a PID constant output device. The database stored in the storage device 68 is systematically configured so that PID constants can be searched based on, for example, the target temperature T, machine setting parameters, environmental conditions (elevation, average temperature) in which the machine is installed, etc. is doing.

  The database is provided by the manufacturer of the hot air drying device 10a, but may be rewritten by the user of the hot air drying device 10a.

  Further, the storage device 68 may be built in the setting device 66 or may be a host computer connected via a communication line, and the specific form is not limited. The host computer may be a database provided by the manufacturer of the hot air drying device 10, for example.

  Table 2 shows, as an example of a database, a set value set in the setting device 66 when the hot air drying device for our warp gluing machine is installed on a flat ground (elevation of 500 m or less) and an annual average temperature of 20 ° C.

  The control block diagram of the hot air drying apparatus 10 shown in FIG. 6 is configured by configuring the setting device 66 shown in the first embodiment (FIG. 2) with a variable resistor 66a such as a potentiometer that outputs a target temperature as an analog electric signal. It is.

  The variable resistor 66a outputs an analog electric signal as a set value signal of the target temperature corresponding to the memory to the temperature controller 52 and the constant signal generator 70 by the operator's operation.

  The constant signal generator 70 functioning as a PID constant output device according to the present invention includes a comparator 72 that compares an input value of an analog electric signal with a plurality of preset threshold values, and a plurality of PID constants set with different PID constants. PID constant setting device 74, a plurality of PID constant setting devices 74, and a switch 76 connected to the comparator 72. The plurality of threshold values set in the comparator 72 correspond to a temperature region (low temperature region, middle temperature region, high temperature region, etc.).

  The switch 76 selects one from a plurality of PID constant setting units 74 based on the signal output from the comparator 72, and uses the PID constant stored in the selected PID constant setting unit 74 as the temperature controller 52. Output to.

  In this way, even if the operator operates the variable resistor 66a to change the set value of the target temperature T, the constant signal generator 70 automatically selects a PID constant suitable for the changed set value Ts. Since the temperature is output to the temperature controller 52, the temperature controller 52 can adjust the control valve 40 so as to always keep the hot air temperature at the changed target temperature Ts.

  The fourth embodiment shows a modification to the second and third embodiments. In this embodiment, the PID constants are accumulated and stored for each target temperature that is divided more finely instead of the rough temperature divisions such as the three temperature regions as in the previous embodiment. PID constants are accumulated and stored for each altitude, annual average temperature, and steam pressure supplied from the steam boiler as environmental conditions for installing the accessory.

  Regarding environmental conditions, for example, heat boiler capacity and steam temperature are related to the heat source, and machine specifications include manufacturer model, production lot number, warp winding width, etc. It is conceivable to store PID constants corresponding to these. As shown in Table 3, the PID constant may be extracted according to other environmental conditions, for example, specifications of other devices.

  Instead of automating the determination processing of the setting value set in the setting device 66, the operator may select a PID constant corresponding to the setting value from a plurality of PID constant setting devices.

  Although the number of divisions of the temperature region in the above embodiment is three, it may be four or more. Moreover, it is preferable that the number of divisions of the temperature region is the same as the number of set target temperatures. The target temperature is generally determined in a range from 50 ° C to 200 ° C.

  The temperature region may be set at equal intervals, and the range of the predetermined temperature region may be wider or narrower than other temperature regions.

  For the embodiment in which PID constants are selected according to the environmental conditions and machine usage conditions described above, the PID constants that are set and stored in advance are all those listed above for each condition, and all those that are considered otherwise. It is conceivable to store them in correspondence with each other, but for simplification, it is conceivable to store them in correspondence with one or more of the above listed items having a high degree of influence. For example, the average temperature as an environmental condition or the supply pressure of steam as a machine specification condition can be considered as a high influence level.

  In the above embodiment, the function of outputting the PID constant corresponding to the target temperature is provided outside the temperature controller 52. However, the temperature controller 52 may be provided with such a function. For example, when the main controller 50 and the temperature controller 52 are configured by a known controller such as a programmable controller, for example, such a PID constant is stored in advance in a memory (not shown) incorporated therein, It is also possible to read from the built-in storage device by inputting the target temperature from the setting device 66.

  Regarding the PID constants corresponding to each target temperature, in Table 1, Table 2, and Table 3 above, all the proportional, integral and derivative constants are set independently with respect to the target temperature. If simplified, a constant that is considered to have a small influence, for example, one of integral constant and differential constant is used in a fixed manner regardless of the target temperature, that is, proportional to either integral constant or differential constant. A plurality of constants can be determined corresponding to the target temperature, and the above-described constants corresponding to the set target temperature can be selected as appropriate.

  The present invention is not limited to the above embodiments, and can be modified within the scope of the gist of the present invention.

It is a conceptual diagram which shows one Example of the hot air drying apparatus which concerns on this invention. It is a block diagram of the hot air drying apparatus shown in FIG. It is a flowchart figure which shows the processing flow of automatic tuning operation of the main controller shown in FIG. The internal processing flow of the setting device shown in FIG. 2 is shown. It is a conceptual diagram which shows another Example of the hot air drying apparatus which concerns on this invention. It is a conceptual diagram which shows another Example of the hot air drying apparatus which concerns on this invention.

Explanation of symbols

S1 Operation signal S2 Heat signal S3 Temperature control command signal S4 Stop signal S5 Tuning operation signal S7 Tuning command signal To Actual detection temperature T Target temperature 10 Hot air dryer 12 Warp 14 Drying chamber 16 Temperature detector 18 Air blower path 20 Blower 22 Air heaters 24, 26 Opening 28 Hot air inlet 30 Hot air exhaust 32 Exhaust machine 34 Exhaust fan 35 Exhaust motor 36 Exhaust duct 38 Opening 40 Control valve 42 Radiator 46 Blower motor 48 Blower fan 50 Main controller 52, 52a Temperature controller 54 Operation button 56 Heat button 58 Stop button 60 Tuning operation button 62 Drying control unit 64 Winding control unit 66 Setting unit 66a Variable resistor 68 Memory unit 70 Constant signal generator 72 Comparator 74 Constant setting unit 76 Switcher

Claims (3)

Used in a hot air dryer that dries a wet warp through a drying chamber,
During the operation of the hot air drying apparatus, based on the deviation of the detected internal temperature of the drying chamber from the set target temperature, a PID calculation is performed by the temperature controller, and the air sent to the drying chamber is sent to the drying chamber according to the result of the PID calculation. In the method of controlling the temperature of the hot air drying device, in which the heating amount is controlled by an air superheater,
A plurality of integral constants and differential constants used in the PID calculation and a proportionality constant are stored in advance in correspondence with each of a plurality of target temperatures;
When the target temperature is set, a constant corresponding to the set target temperature is selected from the stored constants, a PID constant including the selected constant is output to the temperature controller, and hot air drying is performed. During operation of the apparatus, the temperature controller performs a PID calculation based on the deviation and the output PID constant, and outputs a heat amount control signal to the air heater according to the result of the PID calculation. The temperature control method of a hot air dryer. A drying chamber for passing the wet warp and drying;
A temperature detector for detecting the internal temperature of the drying chamber;
A blower for sending air into the drying chamber;
An air heater for heating the air fed into the drying chamber according to a calorie control signal;
A setter for setting a target temperature inside the drying chamber;
A hot air drying apparatus including a temperature controller that outputs a heat amount control signal according to a PID calculation result based on a PID constant and a detected deviation of the internal temperature of the drying chamber with respect to a set target temperature,
The hot air drying device further stores in advance a plurality of integral constants and / or differential constants and proportional constants corresponding to each of the plurality of target temperatures, and selects a constant corresponding to the set target temperature. A PID constant output unit that outputs a PID constant including the selected constant to the temperature controller;
During operation, the temperature controller outputs a heat control signal according to a PID calculation result based on a PID constant output from the PID constant output unit and a detected deviation of the internal temperature of the drying chamber from a set target temperature. A hot air dryer that outputs to the superheater. The temperature controller outputs a predetermined heat amount control signal with respect to a target temperature to the air heater in response to the input of a tuning command signal, and has a tuning function for calculating a PID constant from a change in internal temperature during this period,
The hot air drying apparatus according to claim 2, wherein the PID constant output unit stores the PID constant obtained by the tuning function as a PID constant corresponding to a target temperature.

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