JP2002307506A - Method and apparatus for setting temperature of injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for setting the temperature of an injection molding machine for controlling by lowering a control temperature of a heater by a predetermined temperature evenly from a molding temperature to a heat insulation temperature. SOLUTION: A temperature setting unit 1 has a temperature display/setter 10, a temperature controller 20, and solid state relays 51 to 54. The setter 10 calculates the set value of the heat insulation temperature obtained by evenly reducing a temperature width input from the set temperatures of heaters HN/41, H1/42 to H3/44. The controller 20 controls the relays 51 to 54 based on the calculated set temperature, controls the power supply of a heater power source 90, and holds the temperatures of the heaters HN/41, H1/42 to H3/44 at the control temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature of an injection molding machine in which the control temperature of a plurality of heaters provided in a heating cylinder can be controlled by switching the setting at a time to a heat retaining temperature of the same decreasing width. The present invention relates to a setting method and a temperature setting device.

[0002]

2. Description of the Related Art In order to inject a resin material supplied from a hopper into a heating cylinder of an injection molding machine in a proper molten state from a nozzle, the heating cylinder is divided into a plurality of heating zones, and the temperature of each zone can be controlled. A method of providing a heater and controlling the temperature distribution of the heating cylinder is used. FIG. 3 is a conceptual diagram showing a conventional heating cylinder temperature setting device. In FIG.
Heaters 121 and three heaters 122 to 1 in the cylinder
The control temperature is set by the temperature setting device 100 and the temperature of the heaters 121 to 124 is controlled. The temperature setting device 100 has control temperature setting circuits 101 to 104 for each heater.
In order to control the temperature of the heater 121, the molding temperature Tn
However, the heaters 122 to 124 have respective molding temperatures T1 to T1.
T3 is set. Molding temperature T set for each heater
Since n and T1 to T3 are set so that the heating cylinder has an appropriate temperature gradient, they are not set to the same temperature, but are generally set to have a temperature gradient as shown by a temperature curve 201 shown in FIG. .

When the operation of the injection molding machine is temporarily stopped at night or during a break, or when the operation is temporarily stopped for repair or the like, the temperature of the heating cylinder is maintained at the molding temperature. Problems such as melting of the material and wrapping around the screw valley to make it impossible to send the resin material first occur. Further, when the power supply of the heater is turned off, when the operation is resumed and the molding is started, there arises a problem that the resin material is re-melted and the physical properties are changed. As such a problem does not occur, when the pause operation, the switcher 111 to 114, is switched to the temperature setting circuit 105, the set temperature of all heaters is set to retained temperature T _H shown in FIG. 4 Is done.

[0004]

[SUMMARY OF THE INVENTION However, since the method of setting the temperature of the conventional injection molding machine, when the heating cylinder thermal insulation temperature, the temperature of all the heaters are set to the same heat retention temperature T _H, As shown in FIG. 4, the difference Δ from the molding temperature
T is different in each temperature zone, and since the temperature difference ΔT2 in the highest temperature zone of the heating cylinder becomes larger than the optimum temperature difference ΔT1, it takes time when the temperature is raised from the heat retention temperature to the molding temperature. There was a problem that the effect was lost. In addition, if the difference between the molding temperature and the heat retention temperature is reduced in a zone where the temperature of the heating cylinder is high, and the heat retention temperature is set to Ta so that the optimum temperature difference ΔT1 in the high temperature zone, for example, the temperature zone on the hopper side becomes higher. Insulation temperature is higher than molding temperature by Δ
There is a problem that T3 becomes high and excessive melting of the resin material occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to keep the control temperature of all heaters uniformly lower than a molding temperature by a predetermined temperature when the heating cylinder is kept in a heat-retaining state. It is an object of the present invention to provide a temperature setting method and a temperature setting device for an injection molding machine, which can control the temperature to be optimally maintained in all temperature zones.

[0006]

According to a first aspect of the present invention, there is provided a heater provided in a plurality of heating zones of a heating cylinder, and the temperature of the plurality of heaters is set. A temperature setting device for controlling the temperature of the injection molding machine, wherein when the heating cylinder is to be kept in a heat-retaining state, the temperature of the heater is controlled from a first set temperature set in advance. A temperature range to be uniformly lowered is input to the temperature setting device, and the temperature setting device calculates a second set temperature obtained by subtracting the input temperature range from the first set temperature, and calculates the calculated second set temperature. A temperature setting method for an injection molding machine, wherein the temperature of the heater is controlled based on a set temperature to maintain the temperature at a heat retaining temperature.

[0007] The invention described in claim 2 is the first invention.
The method for setting a temperature of an injection molding machine according to claim 1, wherein
If the temperature obtained by subtracting the temperature range input to the temperature setting device from the set temperature is lower than a predetermined lower limit temperature,
The control temperature is set to a predetermined lower limit temperature.

[0008] The invention described in claim 3 is the first invention.
Alternatively, in the temperature setting method for the injection molding machine according to claim 2, when the heat retaining state of the heating cylinder is stopped, the temperature setting device returns the control temperature of the heater to the first set temperature, and Is heated.

According to a fourth aspect of the present invention, the temperature of a plurality of heaters provided in a heating cylinder of an injection molding machine is set,
A temperature setting device for controlling, comprising: input means for inputting a set value for controlling the heater to be a molding temperature and a temperature range to be uniformly lowered from the set value in order to obtain a heat retaining temperature, and input from the input means. First storage means for storing a set value of the molding temperature, and reading and outputting the set temperature from the first storage means, or the temperature range inputted by the input means from the read set temperature. Calculating means for calculating the heat retention temperature by subtracting the temperature, setting switching means for switching the set temperature for controlling the heater output from the calculation means to the molding temperature or the heat retention temperature, and based on the set temperature inputted from the calculation means. And a temperature control means for controlling the temperature of the heater.

The invention described in claim 5 is the same as the invention in claim 4.
In the temperature setting device for an injection molding machine described in (1), when the setting switching means switches the control temperature setting of the heater from the holding temperature to the molding temperature, the calculating means is stored in the first storage device. It is characterized in that a set value of the molding temperature is read and output to the temperature control means.

[0011] The invention according to claim 6 is the invention according to claim 4.
6. The temperature setting device for an injection molding machine according to claim 5, wherein the temperature control means has a second storage means, and stores a set temperature for controlling the temperature of the heater input from the arithmetic means. And controlling the heater based on the stored set temperature.

[0012] Further, the invention according to claim 7 is based on claim 4.
7. The temperature setting device for an injection molding machine according to claim 6, wherein the temperature control means includes a solid state relay for controlling a current supplied from a heater power supply to the heater.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a heating cylinder of an injection molding machine and a diagram showing a configuration of a temperature setting device 1 according to the embodiment. As shown in the figure, the cylinder portion 60 of the heating cylinder is divided into three heating zones, and each heating zone has heaters H1.42 to H3.444 and a temperature sensor 3
2 to 34 are provided, respectively. The nozzle 70, the heater H _N · 41 and the temperature sensor 31 is provided. The temperature setting device 1 includes heaters H _N · 41, H 1 · 42
To H3 · 44 and a temperature display / setting device 10 for displaying the set temperature and the temperature of each heating zone during operation, and a heater H _N · 4 from the temperature display / setting device 10.
1, a temperature controller 20 for controlling the temperature of each heater in response to the control temperatures of H1 · 42 to H3 · 44, and a solid state relay 5 for controlling the power supply of a heater power supply 90
1-54.

Numeral 12 has an input key, and the heater H _N · 4
1, an input unit for inputting a set temperature for controlling H1 · 42 to H3 · 44 and a temperature range to be lowered when the temperature is kept at the heat retention temperature, and 13 is used to calculate the set temperature to be kept warm and to control the operation of each unit. It is a CPU (Central Processing Unit). 1
Reference numeral 4 denotes a memory that stores the set temperature input from the input unit 12 and a temperature reduction range during the heat retention. Reference numeral 11 denotes a display unit for displaying the set temperature and the temperature of each heating zone during operation. Reference numeral 15 denotes a setting switch button for setting the set temperature to a heat retaining temperature. Reference numeral 21 denotes a memory for storing the set temperature input from the temperature display / setting device 10, and reference numeral 22 denotes a heater H _N · 4 based on the set temperature stored in the memory 21.
1, a CPU that controls the temperature of H1.42 to H3.44 and controls the operation of each unit. 23 has an A / D converter (analog / digital converter) and has a temperature sensor 31
This is an input unit that converts the measured temperature values output from the digital-to-analog converters into digital signals and supplies them to the CPU 22. 24 is
With D / A converter (digital / analog converter), C
An output unit that converts a control signal from the PU 22 into an analog signal. 51 to 54, light emitting diode and a solid state relay composed of a semiconductor control element, the heater H _N · 4 from the heater power source 90 by the output of the output section 24
1. Control power supply to H1.42 to H3.444.

Next, the operation of the temperature setting device configured as described above will be described with reference to FIGS. FIG. 2 is a diagram showing the flow of the heat retention temperature setting process. First,
The setting of the molding temperature will be described. The input keys of the input unit 12, a heater _{H N · 41, H1 · 42~H3} · 44
Enter and set the temperature to control. The control temperature of each heater is set to have an optimal temperature gradient in consideration of the molten state of the resin moving in the heating cylinder. Temperature curve 201 of FIG. 4, the heater _{H N · 41, H1 · 42~H3} · 4
4 shows an example of a control temperature when molding is set to 4.
The CPU 13 receives the heater H _N input from the input unit 12.
・ 41, H1 ・ 42 ~ H3 ・ 44 Set temperature in memory 1
4 and display on the display unit 11. Then, the set temperature is sent to the temperature controller 20. CPU ・ 22
Causes the memory 21 to store the input set temperature.

When the operation of the injection molding machine is started, the CPU
22 reads out the set temperature stored in the memory 21, compares it with the temperature of each heating zone measured by the temperature sensors 31 to 34, and outputs a control signal. Output unit 24
Converts the digital control signal output from the CPU 22 to generate an analog control signal for controlling the solid state relays 51 to 54. Light emitting diode of the solid state relay 51 to 54, by changing the light-emitting state by a control signal supplied from the output unit 24, and controls the semiconductor control element, the heater H _N · 41 from the heater power source 90,
The current supplied to H1 · 42 to H3 · 44 is turned “ON”, and each heater is heated to the set temperature. Input unit 23
Converts the measured temperature values output from the temperature sensors 31 to 34 into digital signals and sends them to the CPU 22. CPU ・
Reference numeral 22 compares the measured temperature value with the control temperature set in each of the heaters H _N · 41 and H 1 · 42 to H 3 · 44 stored in the memory 21. _When the control temperatures of _N · 41 and H1.42 / H3 · 44 are reached, a signal for controlling the heater power supply of the heating zone is generated. The output unit 24 outputs a control signal to the corresponding solid state relays 51 to 54 based on this signal, and outputs the current supplied from the heater power supply 90 to “OF”.
F ". Further, the temperature controller 20 outputs the measured temperature value to the temperature display / setting device 10. The temperature display / setting device 10 causes the display unit 11 to display the temperature of each heating zone based on the measured temperature value.

Next, the setting of the heat retaining temperature when the operation of the injection molding machine is temporarily stopped to be kept warm will be described in detail with reference to FIG. First, heaters H _N · 41, H1 ·
In order to set the set temperature of 42 to H3 · 44 to the insulation temperature,
With the input keys of the input unit 12, a temperature range (ΔT) for uniformly lowering the set temperature is input (step S11). The optimum temperature is determined in consideration of the molten state of the resin in the heating cylinder in the heat retaining state. Next, the set temperature is switched to the heat retention setting by the setting switching button 15 (step S12). The CPU 13 receives the signal of the setting switching button 15 and reads out the set values of the molding temperature stored in the memory 14 and calculates the set value of the heat retention temperature obtained by subtracting the set temperature from the set values. (Step S1
3). The calculated set value is, as shown by the temperature curve 202 in FIG. 4, a temperature obtained by uniformly subtracting the temperature range ΔT1 from the molding temperature, and has a temperature gradient similarly to the molding temperature.

Next, the calculated heaters H _N · 41 and H 1
• The set values of 42 to H3 · 44 are compared with the lower limit temperatures stored in the memory 14, respectively, and it is determined whether the lower limit temperature is exceeded (step S14). If the calculated set value is lower than the lower limit temperature and is “NO”, step S15
The CPU 13 outputs the lower limit temperature as the set value of the temperature control of the corresponding heater. If the result of the determination in step S14 is "YES", the CPU 13 outputs the calculated set value. The set temperature output from the CPU 13 is displayed on the display unit 11 and sent to the temperature controller 20.
This set temperature is stored in the memory 21 (step S1).
6). Then, a control signal based on the set temperature is output.

The output unit 24 generates a control signal for controlling the solid state relays 51 to 54 based on the signal output from the CPU 22. Solid state relay 5
1-54 is Hitahita from the heater power source 90 by a control signal supplied from the output section _{24 H N · 41, H1 ·} 4
The current supplied to 2 to H3 · 44 is turned “OFF”, and the temperature of each heating zone is lowered to the heat retention temperature. CPU ・ 22
Receives the temperature measurements of the temperature sensors 31 to 34 via the input unit 23 compares the set temperature stored in the temperature measurement value and the memory 21, the heater H _N · 41, H1 · 4
Control is performed so that the temperatures of 2 to H3 · 44 are maintained at the set temperature. In addition, the temperature measurement value is output to the temperature display / setting device 10, and the temperature display / setting device 10 causes the display unit 11 to display the temperature of each heating zone in the warming state based on the temperature measurement value.

When the operation of the injection molding machine is restarted, the heat retention state is set to "OFF" by the setting switching button 15. C
The PU 13 receives the “OFF” signal from the setting switching button 15, reads out the set value of the molding temperature from the memory 14, and outputs it to the temperature controller 20. The display unit 11 displays the molding temperature read from the memory 14. The temperature controller 20 causes the memory 21 to store the set temperature input from the CPU 13. Hereinafter, the above-described operation, the temperature controller 20, heater H _N · 41 controls the solid state relay 51 to 54, H1 ·
42 to H3 · 44 are heated to the set temperature stored in the memory 21.

[0021]

As described above, according to the present invention,
When the heating cylinder of the injection molding machine is kept warm, the optimal temperature range from the molding temperature can be entered and the set temperature can be lowered uniformly to set the warming temperature. Since the gradient is maintained and the temperature of the heating cylinder can be maintained in an optimum state, there is no problem due to thermal degradation of the resin material and the effect that the operating cost of the injection molding machine can be reduced. Also, in the heating zone where the temperature is high, the reduction of the molding temperature and the heat retention temperature can be set to the optimum values, so that the time until the operation is restarted and the temperature of the heating cylinder stabilizes can be shortened, thereby saving power consumption. The effect that it can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a temperature setting device of an injection molding machine according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a flow of a heat retention temperature setting process.

FIG. 3 is a conceptual diagram of a conventional temperature setting device of an injection molding machine.

FIG. 4 is a diagram showing a setting example of a forming temperature and a heat retaining temperature of a heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Temperature setting device of injection molding machine 10 Temperature display / setting device 11 Display unit 12, 23 Input unit 13, 22 CPU 14, 21 Memory 15 Setting switch button 20 Temperature controller 24 Output unit 51-54 Solid state relay

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4F206 JA07 JL02 JL08 JM01 JN03 JP13 JP17

Claims (7)

[Claims] 1. A temperature setting method for an injection molding machine, comprising: a heater provided in a plurality of heating zones of a heating cylinder; and a temperature setting device for setting and controlling the temperatures of the plurality of heaters. When the cylinder is to be kept warm, a temperature range that is uniformly reduced from a first set temperature set in advance to control the temperature of the heater is input to the temperature setting device, and the temperature setting device is input. Calculating a second set temperature obtained by subtracting the set temperature range from the first set temperature, and calculating the calculated second set temperature.
And controlling the temperature of the heater based on the set temperature to maintain the temperature of the injection molding machine. 2. A control temperature is set to a predetermined lower limit temperature when a temperature obtained by subtracting the temperature range inputted to the temperature setting device from the first set temperature is lower than a predetermined lower limit temperature. The method for setting a temperature of an injection molding machine according to claim 1, wherein: 3. When the heat retaining state of the heating cylinder is stopped,
The temperature setting device sets the control temperature of the heater to the first temperature.
The temperature setting method for an injection molding machine according to claim 1, wherein the temperature is returned to the preset temperature, and the heater is heated. 4. A temperature setting device for setting and controlling the temperature of a plurality of heaters provided in a heating cylinder of an injection molding machine, comprising: a set value for controlling the heater to a molding temperature; Input means for inputting a temperature range to be uniformly lowered from the set value, a first storage means for storing a set value of the molding temperature input from the input means, and a set temperature from the first storage means. Calculating means for calculating the heat retention temperature obtained by subtracting the temperature range input from the input means from the read set temperature, and setting for controlling the heater output from the calculating means. Injection, comprising: setting switching means for switching a temperature to a molding temperature or a heat retaining temperature; and temperature control means for controlling the temperature of the heater based on the set temperature input from the arithmetic means. Temperature setting device in the form machine. 5. When the setting switching means switches the control temperature setting of the heater from the warming temperature to the molding temperature, the arithmetic means reads the molding temperature setting value stored in the first storage device. 5. A temperature setting device for an injection molding machine according to claim 4, wherein the temperature is output to said temperature control means. 6. The temperature control means has a second storage means, stores a set temperature for controlling the temperature of the heater input from the arithmetic means, and sets the heater based on the stored set temperature. The temperature setting device for an injection molding machine according to claim 4, wherein the temperature is controlled. 7. The injection molding machine according to claim 4, wherein said temperature control means includes a solid state relay for controlling a current supplied from a heater power supply to said heater. Temperature setting device.