KR101275393B1 - Heater control device for use in injection molding apparatus - Google Patents

Abstract

A heater control device suitable for use in an injection molding machine is disclosed. Such a heater control device includes: a first driver for controlling a phase of an AC power source to be applied to the heater in response to a first drive control signal applied; A second driver for directly switching the AC power to the heater in response to an applied second drive control signal; And a controller for generating the first driving control signal and the second driving control signal together when the set temperature of the mold is greater than a predetermined range than the measured current temperature of the mold. The life of the power control device can be extended.

Description

Heater control device for use in injection molding apparatus

TECHNICAL FIELD The present invention relates to heater control, and more particularly, to a heater controller suitable for use in mold heating of an injection molding machine.

As is known, an injection molding machine is a molding apparatus which injects molten resin into a cavity in a mold to obtain an injection product in the shape of the cavity. Injection molding machines and molds are indispensable for mass production because injection molding machines can be repeatedly used to obtain the same shape in a short time.

The mold which is essentially mounted on the injection molding machine is provided with a heater for heating the mold or a heater for heating the hot runner in the mold, and a controller for controlling such heaters is almost necessarily employed.

In order to achieve completeness of the injection molded product and homogenization between the products, the temperature of the heater needs to be kept constant while the injection molding operation is maintained.

Conventionally, in order to maintain a constant temperature of a mold or a hot runner in a mold by controlling the heating of a heater, a mold power controller or a hot runner heater controller includes a general-purpose temperature controller and a triac (TRIAC) or thyristor. Element is employed.

Such a conventional heater control device has a full load on the heater through the semiconductor power control element when heating from the current temperature to the target set temperature due to the temperature change due to the initial driving or the mold replacement. Allow the current to be the heating source to be applied. When the temperature difference is relatively large and current is supplied to the heater at full load (100%), heat generation is increased in the semiconductor power control device. In particular, when the heater capacity is relatively large, the semiconductor power control element, such as triac or thyristor, is raised to a high temperature by heat generation. When the semiconductor power control device is heated to a high temperature by heat generation, the accuracy of temperature control is reduced, and the lifespan of the semiconductor power control device itself and the surrounding components are affected by the high heat.

Therefore, the size of the heat sink or heat sink installed in the heater control unit should be large, and a cooling fan for forcibly dissipating heat inside the control box containing the heater control unit should be provided and operated from time to time or for precise temperature control. There is a problem.

The problem to be solved by the present invention is to provide a heater control device suitable for an injection molding machine that can suppress or minimize the temperature rise inside the control box or the temperature rise of the electronic components.

Another object of the present invention is to provide a heater control apparatus suitable for a device employing a semiconductor power control element that can reduce or minimize the heat generation problem of the semiconductor power control element due to an increase in current when the heater temperature rises.

Another object of the present invention is to provide an improved heater control device capable of more precisely controlling the heat generation of the heater by suppressing heat generation in the heater control device.

Another object of the present invention is to provide a heater control device capable of making the size of the heater control device compact by making the size of the heat sink provided in the heater control device relatively small.

Another problem to be solved by the present invention is to provide a heater control device that can increase the life of the triac or thyristor.

According to an exemplary aspect of the present invention for achieving the above technical problem, a heater control device having a heater to control the mold of the injection molding machine to a set temperature:

A first driving unit controlling a phase of an AC power to be applied to the heater in response to the first driving control signal applied;

A second driver for directly switching the AC power to the heater in response to an applied second drive control signal; And

And a control unit for generating the first driving control signal and the second driving control signal together when the set temperature of the mold is a predetermined range or more than the measured current temperature of the mold.

In an embodiment of the present disclosure, the first driver may be a semiconductor power control device including a triac or thyristor.

In an embodiment of the present disclosure, the first driving control signal may be generated in a pulse form.

In an embodiment of the present disclosure, the second driver may be a DC relay element.

In an embodiment of the present disclosure, the controller may store heat generation history management data of the semiconductor power control device.

In an embodiment of the present disclosure, the heater control apparatus may further include a communication unit to transmit the heat generation history management data to the outside.

In an embodiment of the present disclosure, the heater controller may further include an operation setting unit to protect the first driving unit in various modes according to a user's mode selection.

In an embodiment of the present disclosure, the heater controller may perform a heating operation amount calculation based on a difference between the current temperature and a set temperature in a driving mode of the heater by default and drive the DC relay element according to the calculated heating operation amount. have.

According to another aspect of an embodiment of the present invention for achieving the above technical problem, a heater control device having a heater to control the hot runner in the mold of the injection molding machine to a set temperature:

A first driving unit controlling a phase of an AC power to be applied to the heater in response to the first driving control signal applied;

A second driver for directly switching the AC power to the heater in response to an applied second drive control signal; And

When the set temperature of the hot runner is a predetermined range or more than the measured current temperature of the hot runner may be provided with a control unit for generating the first drive control signal and the second drive control signal together.

In an embodiment of the present disclosure, the controller may vary the predetermined range according to the internal temperature of the control box in which the heater control device is located.

In an embodiment of the present disclosure, the controller may transmit heat management data of the first driver to the outside in a communication mode.

According to the exemplary configuration of the present invention as described above, the temperature rise inside the control box of the injection molding machine or the temperature rise of the electronic component may be suppressed or minimized.

In a heater control device suitable for a device employing a semiconductor power control device, a heat generation problem of the semiconductor power control device due to an increase in current when the heater temperature rises may be reduced or minimized.

By suppressing the heat generation in the heater control device there is an advantage that can more precisely control the heat generation of the heater.

By making the size of the heat sink provided in the heater control device relatively small, the size of the heater control device can be made more compact.

By minimizing the heat generation of components, there is an advantage that can increase the life of the triac or thyristors used in the heater control device.

1 is a block diagram of a heater control apparatus according to an embodiment of the present invention;
2 is a circuit block diagram according to a detailed implementation example of FIG. 1;
3 is a table illustrating a setting of operation modes related to FIG. 2;
4 is a flowchart illustrating a heating operation control according to FIG. 2;
5 is a flowchart illustrating a part management operation control according to FIG. 2, and
6 is a flowchart illustrating a heating operation control for each mode setting according to FIG. 2.

Hereinafter, according to a preferred embodiment of the present invention, the configuration and operation of the heater control device will be described in detail with reference to the accompanying drawings. Meanwhile, in describing the embodiments of the present invention, detailed descriptions of well-known functions or configurations of related circuit blocks will be omitted if it is determined that the present invention may unnecessarily obscure the subject matter of the present invention. For example, the details of the power control mechanism of the triac or thyristor are well known in the art, and thus detailed description thereof is omitted.

In the embodiment of the present invention, as shown in FIG. 1, a microcomputer is employed as the control unit 10 of the heater control device, and a relay element or the like is used to reduce or minimize the heat generation problem of the main drive unit 20 including triac or thyristor. The auxiliary drive unit 30 is further employed. Here, the auxiliary driver 30 is connected to the heater 40 in parallel with the main driver 20. 1 is a block diagram of a heater control apparatus according to an embodiment of the present invention, which is simplified and illustratively configured.

The control unit 10 checks the sensing output of the temperature detecting unit 50 and determines that the set temperature of the mold or hot runner is greater than a predetermined range than the measured current temperature of the mold or hot runner by the first and second output terminals ( The main driving unit 20 and the auxiliary driving unit 30 are simultaneously driven by generating the first driving control signal and the second driving control signal through P1 and P2. Accordingly, the heat generation of the semiconductor power control element constituting the main driver 20 is reduced or minimized due to the current driving operation of the auxiliary driver 30. If it is determined that the temperature of the mold or hot runner rises near the set temperature, the controller 10 disables the current driving operation of the auxiliary driving unit 30 and allows the current driving to be performed only by the main driving unit 20. In this way, the load on the operation amount, that is, the current amount for heating the heater, is continuously calculated by the controller 10, and the operation of the auxiliary driver 30 is determined according to the magnitude of the load.

Therefore, even when the heater temperature is to be increased, the heat generation of the semiconductor power control element is greatly reduced, so that the size of the heat sink to enter the control box can be made smaller. In addition, since the temperature rise in the control box and the main drive unit can be suppressed or minimized, the temperature of the heater is precisely controlled so that the temperature of the mold or the hot runner is always maintained at the set temperature. .

FIG. 2 is a circuit block diagram according to the detailed implementation example of FIG. 1, and a wiring structure of the main driver 20, the auxiliary driver 30, and the heater 40 is shown in detail in comparison with FIG. 1. 2, in addition to the temperature sensing unit 50, the operation setting unit 60, the display unit 70, and the communication unit 80 are further connected to the control unit 10.

In FIG. 2, the resistors 21 and 24, the photo triac 22, and the triac 23 are included in the main driver 20. When the first driving control signal is applied through the resistor 21, the photo triac 22 is activated to control the gate of the triac 23. As a result, the AC power P1 is controlled by the gate and applied to the heater 40.

In addition, the transistor 31 and the relay element 32 are included in the auxiliary driver 30. The relay element 32 may include a switch (SW), an inductor (L), and a diode (D). When a voltage of a predetermined level is applied to the base of the transistor 31 and the transistor 31 is turned on, the voltage is supplied from the collector of the transistor 31 to the emitter through the inductor L at the power supply voltage VDD. Current flows along the current path. As a result, the switch SW for switching the AC power P1 is closed, and the AC power P1 is supplied to the heater 40. As a result, the control unit 10 outputs the second driving control signal to the second output terminal P2 when the amount of operation exceeds a predetermined range so that the switch SW of the relay element 32 which is a DC relay element is switched. do.

When the temperature rises rapidly and reaches a predetermined range, the control unit 10 causes the relay element 32 to be disabled and controls the driving of the triac 23 only with the first driving control signal. Therefore, when the operation amount is large, the triac 23 may minimize or reduce element heat generation with the help of the relay element 32. Here, the first driving control signal may be generated in the form of a pulse such as PWM. Here, the triac 23 may be embodied as "BTA41600B".

The controller 10 may store heat generation management data of the semiconductor power control device in an internal memory. The memory is a memory for storing program and work data, and may include a DRAM and a flash memory.

The communication unit 80 not only performs the function of transmitting the heating history management data to the outside, but also receives various data applied from the outside such as a remote control unit or a communication network and transmits the data to the port P6 of the control unit 10. Can be. The communication unit 80 may be connected to a remote main controller of the injection molding machine through an RS 485 communication line, or may be connected to various controllers through wireless communication. Accordingly, various injection molding environments can be changed by transmitting a program mounted on a computer or a smart phone to the controller 10, and the preventive maintenance can be performed by checking the heat generation history management data of the semiconductor power control device from an external remote location. Provide a factor.

The operation setting unit 60 may be connected to the port P3 of the control unit 10 to protect the first driving unit 20 in various modes according to the user's mode selection. The engraving setting unit 60 may include a setting keypad having various functions and an operation interface. An operation signal generated in response to a user's touch or key operation is applied to the controller 10 through an operation interface. The keypad and the operation interface of the operation setting unit 60 are HT100A-NDOBP02 and HT-EBS4-1. Each can be configured as / RS232C.

On the other hand, without selecting such various modes, the control unit 10 performs a heating operation amount calculation according to the difference between the current temperature and the set temperature in the driving mode of the heater 40 as a default, and according to the calculated heating operation amount, the DC relay The element 32 can be driven. The DC relay device may be implemented as a general-purpose device, “HR85AKSW DC24”.

The heater 40 may be a heater for controlling not only the mold of the injection molding machine but also a hot runner in the mold at a set temperature. Although one heater is shown in the figure, it can be increased by the required number if necessary. For example, in the case of three heaters and a three-phase three-wire type, each heater may be connected to the AC power supply phases R, S, and T, and may be connected to each other by a shared delta.

The display unit 70 connected to the control unit 10 through the port P5 may be implemented as an LCD, and may include a driving unit for driving the LCD. In this case, the LCD and the driver may be implemented using "digital RGB" and "AT070TN83", respectively. If necessary, when the display unit 70 adopts a touch screen, the manipulation setting unit 60 may be provided integrally with the display unit 70.

The temperature sensing unit 50 connected to the control unit 10 through the port P4 may include a plurality of temperature sensors and a sensor interface. When the plurality of temperature sensors are three and distributed in the vicinity of a mold on which the heater 40 is mounted or in the vicinity of a hot runner, the three sensing signals S1, S2, and S3 are controlled through the sensor interface. Can be applied as

FIG. 3 is an example table of setting operation modes related to FIG. 2, which may be provided as an option according to need.

Referring to the drawings, the standard mode M31, the first safety mode M32, the second safety mode M33, and the manual mode M34 may be displayed on the display unit 70 of FIG. 2. When the operator selects, for example, the first safety mode through the operation setting unit 60, the controller 10 receives data "01" and recognizes that there is an operation selection of the first safety mode. Accordingly, the controller 10 performs the parallel mode of driving the auxiliary driver 30 in the range of the first load (eg, 30% remaining) set for device protection (triac or thyristor protection) of the main driver 20. do. Here, it is assumed that the range of the first load is set wider than the range of the third load. For example, if the set temperature is 250 degrees Celsius (° C.) and the current mold or the internal hot runner temperature is 200 degrees Celsius, the relay element, which is the auxiliary driver 30, is not driven because it is already over 30%. .

On the other hand, when the operator selects the second safety mode, the operation is performed in the range of the second load (eg, 10% remaining), and the relay element 32 remains closed until it rises to 225 degrees Celsius. As a result, in the second safe mode, much more attention is paid to device protection than the first safe mode.

In addition, even in the standard mode for driving only the main drive unit 20 or in the first and second safety modes, when the quality and precision of the injection-molded product are not satisfactory due to element protection or heat generation inside the control box, the amount of load is increased. The manual mode that adjusts to the user's discretion can be selected. Therefore, when the injection operation is carried out in the tropics or tundra region, the appropriate protection mode can be selected.

On the other hand, even without the selection operation of Figure 3, the heater controller performs a heating operation amount calculation according to the difference between the current temperature and the set temperature in the drive mode of the heater by default and as shown in Figure 4 according to the calculated heating operation amount The DC relay device may be driven by performing a control flow.

4 is a flowchart illustrating a heating operation control according to FIG. 2.

The control flow of FIG. 4 shows a case where the control unit 10 of FIG. 2 is performed as default operation control.

In operation S40, an initialization operation of the device is performed. In this step, the control unit 10 sets the stored values of various flags and registers in the microprocessor to an initial step. In step S41, it is checked whether the heater is in drive mode. Here, the heater driving mode may be a mode that is automatically set while the injection molding operation or the injection molding is prepared.

If it is the driving mode of the heater, the current temperature and the set temperature are read in step S42. Here, the set temperature means the temperature of the mold or the temperature of the hot runner to be maintained in the injection molding and is a target temperature. As a result, the heater control is to repeatedly perform the operation of supplying the heater current when the current temperature is lower than the set temperature, and stopping the supply of the heater current when the current temperature reaches the set temperature. The current temperature is the temperature of the mold or hot runner sensed by the temperature sensor 50.

The controller 10 calculates an operation amount to know how much current should be supplied to the heater in step S43. Here, the manipulated variable may be represented by the amount of power and the time calculated according to the difference between the set temperature and the present temperature. In the case of large temperature differences, the manipulated value is calculated by supplying the maximum current by X (X is a natural number of 1 or more). In the case where there is little temperature difference, the manipulated value can be calculated by supplying a driving current X seconds lower than the maximum current. Of course, in this case, the current supply through the DC relay element 32 may be blocked.

In step S44, it is checked whether the operation amount is equal to or larger than the set value. The set value may be a value representing a difference between the set temperature and the present temperature as a ratio. In other words, if the set value is 10%, the current temperature is 260 degrees Celsius and the set temperature is 300 degrees Celsius, the current temperature does not yet have a difference of 10%. In this case, step S45 is performed. The step S45 is a step of performing main and auxiliary drive control, and the controller 10 generates the first drive control signal and the second drive control signal together through the first and second output terminals P1 and P2. do. Thus, AC power is provided to the heater 40 in parallel via the triac 23 and the relay element 32 of FIG. 2. In this case, the current amount through the relay element 32 is not controlled, the full current amount of the AC power supply P1 is applied to the heater 40 as it is. Therefore, since the current supply time of the triac 23 is shortened, heat generation of the triac 23 is reduced or minimized.

If the present temperature is steadily raised toward the set temperature and the operation amount falls within the range of the set value, step S46 is performed to perform only main drive control. The controller 10 changes the second driving control signal from a high level to a low level through the second output terminal P2. Accordingly, the transistor 31 of FIG. 2 is turned off so that the switch SW of the relay element 32 is opened. The operation of the main drive continues until the present temperature reaches the set temperature.

If the mode is off in step S46, the controller 10 ends the heating driving mode.

Although not described in FIG. 4, the controller 10 continuously reads the current temperature and continuously calculates the manipulated variable in order to maintain the set temperature at all times.

5 is a flowchart illustrating a part management operation control according to FIG. 2.

After the initialization of step S51, the controller 10 of FIG. 2 reads the heating history information in step S52. Here, the heat generation history information may be information on the heat generation history of the heater and may be history data obtained by sensing a current temperature over time.

In step S53, the controller 10 reads the temperature inside the control box. It is possible to install a separate temperature sensor in the vicinity of the triac 23 and obtain an internal sensing temperature therefrom.

In step S54, it is checked whether the parallel mode of supplying heater power in parallel is being performed. In the parallel mode, the control unit 10 adjusts the load for the main driving control according to the internal temperature in step S55. If the internal temperature is relatively hot, the load is lowered to reduce the control load through the triac 23. As such, the device protection is optimally considered by allowing a certain range of the control load to be varied according to the internal temperature of the control box.

If it is the communication mode in step S56, management data is transmitted and received in step S57. The management data transmitted may be the heat generation history information and the main driving control load adjustment data, and the management data received may be data given from a remote control unit or other connected control unit. The format of the management data can be largely composed of head, body, and tail regions. The body region may consist of a location, a command, and arguments.

6 is a flowchart illustrating a heating operation control for each mode setting according to FIG. 2.

The heating operation control flow according to the user selection mode may be based on PID control. PID control (proportional integral derivative control) is a type of feedback control that allows the output of the system to maintain a reference voltage based on the error between the control variable and the reference input. It is known to combine proportional control, proportional-integral control, and proportional-derivative control. . P control (proportional) produces a control signal by multiplying the error signal between the reference signal and the current signal by an appropriate proportional constant gain. I control (proportional integration) uses integral control in parallel to proportional control, which integrates the error signal to produce a control signal. D control (proportional derivative) uses differential control in parallel to proportional control to differentiate the error signal to produce a control signal. The control is a control method used not only to measure the reaction of the automation system but also to control the reaction, and is used to control temperature, pressure, flow rate, rotation speed, and the like. The control can improve the disadvantages of the PI or PD control, such as the nature of the transient state.

After the PID initialization in step S60, the controller 10 reads the current temperature in step S61 and reads the set temperature in step S62.

In step S63, whether the standard mode is set or not is checked. When the standard mode is set as described in FIG. 3, step S64 of controlling the main driving, step S65 of checking the arrival of the set temperature, step S66 of performing the main driving stop when the set temperature is reached, and returning to step S61 Step S67 is performed in turn. That is, by checking the existence of the standard mode and performing only the main drive control in the standard mode. Accordingly, current is supplied for heating of the heater 40 by driving only the triac 23.

In step S68, it is checked whether or not the parallel mode is set. In this case, the parallel mode includes the first and second safety modes of FIG. 3 and the manual mode.

Therefore, if it is checked in parallel mode, the manipulated variable is calculated in step S69 and main and auxiliary drive control are performed in step S70. As a result, the relay element 32 is further driven so that current is supplied to the heater 40 through the relay switch SW. When the predetermined temperature is reached in step S71, the auxiliary drive is stopped in step S72. As a result, in the final temperature increase process in which the present temperature reaches the set temperature, the auxiliary driving through the relay element 32 is stopped, and the current is supplied only by the triac 23. The triac 23 may control the phase of the AC power P1 to be applied to the heater 40 according to a control signal of a gate terminal to which one end of the resistor 24 is connected.

Through the control flow of FIG. 6, the protection of the semiconductor power control device may be performed at an application site and user-customized.

In the above-described embodiments of the present disclosure, the control operation for controlling the heating may include a computer readable medium including program instructions for performing operations implemented by various computers. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.

In the above description, the embodiments of the present invention have been described with reference to the drawings. . For example, in other cases, the circuit configuration or elements of the auxiliary driver may be variously changed without departing from the technical spirit of the present invention. In addition, of course, the communication method through the communication unit can be changed or changed in other communication methods or various.

Description of the Related Art [0002]
10:
20: main drive unit
30: auxiliary drive unit
40: heater

Claims (12)

In a heater control device having a heater to control a mold of an injection molding machine to a set temperature:
A first driving unit controlling a phase of an AC power to be applied to the heater in response to the first driving control signal applied;
A second driver connected to the heater in parallel with the first driver and directly switching the AC power to the heater in response to an applied second drive control signal; And
And a controller for generating the first driving control signal and the second driving control signal together when the set temperature of the mold is a predetermined range or more than the measured current temperature of the mold.
The heater control apparatus of claim 1, wherein the first driving unit is a semiconductor power control device.
The heater control apparatus according to claim 2, wherein the semiconductor power control element comprises a triac or thyristor.
The heater control apparatus of claim 1, wherein the first driving control signal is generated in a pulse form.
The heater control apparatus according to claim 2, wherein the second driving unit is a DC relay element.
The heater control apparatus according to claim 2, wherein the controller stores heat generation history management data of the semiconductor power control device.
The heater control apparatus of claim 6, wherein the heater control apparatus further includes a communication unit to transmit the heat generation history management data to the outside.
The heater control apparatus of claim 6, wherein the heater control unit further includes an operation setting unit to protect the first driving unit in various modes according to a user's mode selection.
6. The heater control apparatus of claim 5, wherein the heater controller performs a heating operation amount calculation based on a difference between the current temperature and the set temperature in a driving mode of the heater by default and drives the DC relay element according to the calculated heating operation amount. Heater control device.
A heater control apparatus comprising a heater for controlling a hot runner in a mold of an injection molding machine to a set temperature:
A first driving unit controlling a phase of an AC power to be applied to the heater in response to the first driving control signal applied;
A second driver connected to the heater in parallel with the first driver and directly switching the AC power to the heater in response to an applied second drive control signal; And
And a controller for generating the first driving control signal and the second driving control signal together when the set temperature of the hot runner is a predetermined range or more than the measured current temperature of the hot runner.
The heater control apparatus of claim 10, wherein the controller varies the predetermined range according to an internal temperature of a control box in which the heater control apparatus is located.
The heater control apparatus of claim 10, wherein the controller transmits heat management data of the first driver to the outside in a communication mode.

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