Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/84—Safety devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/76—Measuring, controlling or regulating
  • B29C45/78—Measuring, controlling or regulating of temperature

Definitions

• the present invention relates to an injection motor control method for an injection molding machine, and in particular, can surely set injection molding conditions under which the injection motor does not become overmature.
• the present invention relates to an injection motor control method having an overheat prevention function.
• a periodic motor (hereinafter, referred to as an injection motor) is used as a drive source of the injection equipment in the injection molding machine, and the injection motor is used to perform injection, pressure holding, and measurement. It is known to apply a back pressure.
• the output torque of the injection motor during the injection operation and the application of back pressure is small, and extremely small for the injection motor.
• the emission motor is selected in consideration of various design conditions such as economy, and therefore, the driving current is always larger than the continuous current rated current. It is generally not possible to use a motor as a firing motor. As a result, the driving current during holding pressure greatly exceeds the continuous rated current,
• the average value of the drive current flowing to the injection motor during the injection molding cycle may exceed the continuous rated current. In such a case, the injection motor may be overheated. Disclosure of the invention
• the present invention is intended to solve the problems of the conventional injection motor control, because the average injection motor drive current is higher than the continuous rated current and the overheat is easy. Injection motor conditions can be easily checked in advance whether or not the injection motor can become over-ripened prior to the execution of the injection molding cycle under the conditions. It is an object of the present invention to provide an injection motor control method for an injection molding machine that can prevent the heat of a child from being overheated.
• the injection motor control method having an overmaturation prevention function according to the present invention is applied to one injection molding cycle prior to executing the injection molding cycle under various set injection molding conditions. Injection molding conditions over which the integrated value of the ripening amount due to the drive motor current exceeds the allowable integrated value of the amount of heat generated when the continuous rated current flows. It is determined in advance based on the new set value, and when it is determined that the overheat condition can occur, a warning output is issued.
• the product of the heat generation amount due to the injection motor drive current over the injection molding cycle is determined in advance based on the set input value of the injection molding conditions whether or not an overheating state that may exceed the allowable integral value of the ripening amount when the continuous rated current flows is determined.
• a warning output will be issued when it is determined that an overmaturation state may occur.Therefore, while the injection molding cycle is being executed or the execution is stopped.
• Setting of injection molding conditions to be performed It is possible to easily confirm in advance whether or not an overheating state of the injection motor can occur at the time of input, and it is possible to prevent the occurrence of an overmature state of the injection motor. Wear .
• FIG. 1 is a flowchart of a control program for implementing an injection motor control method according to an embodiment of the present invention.
• FIG. 2 is a diagram for explaining the concept of the injection motor control according to the embodiment
• FIG. 3 is a schematic diagram showing the main parts of an injection molding machine to which the control method of the embodiment is applied. It is a configuration diagram.
• FIG. 3 shows a main part of an injection molding machine to which an injection motor control method according to the present invention is applied, and the injection molding machine is a computer.
• Built-in numerical control device (hereinafter referred to as NC device) 1 Supports each axis for emission, clamp, screw rotation, and edge Icta.
• the motor and various actuators (only the injection motor 3 that drives the screw 2 in the injection direction are shown) are provided for driving and controlling the motor.
• the NC device 1 has a numerical control microprocessor (hereinafter referred to as an NC CPU) 10 and a programmable machine controller.
• a microprocessor (hereinafter referred to as PMC CPU) 20 is provided.
• the CPU 10 for the NC has a ROM 11 that stores a management program that controls the injection molding as a whole, and the data is temporarily stored during various arithmetic processing.
• RAM 12 are connected to each other, and each axis is connected via a servo interface 13. Circuit (only the servo circuit 14 for the injection motor 3 is shown) is connected.
• R0M2 which stores the sequence program of the injection molding machine, etc.
• RAM22 which stores the calculation results in a timely manner, Is connected.
• the R 0 M 21 has the following minimum cycle time DT, the maximum pressure MP at the time of maximum torque output of the injection motor 3, a predetermined allowable ratio R max, a warning and an allowable message.
• the diary is pre-recorded.
• a pass erbiter controller 3 is connected to both CPUs 10 and 20 via a path.
• the passivator controller 31 includes a control program for various controls of the injection molding machine, a non-volatile shared RAM 3 for storing various set values described later. 2, an operator panel controller 34 to which the MDIZGRT 33 is connected, an input circuit 35, and an output circuit 36 are connected to each other via a path. Although not shown, various actuators and the like are connected to the circuits 35 and 36.
• the NC unit 1 operates the setting key (software shown in the illustration) provided on the MDIZCRT 33 by an operator to display the molding condition setting screen on the MDIZCRT 33.
• the setting key software shown in the illustration
• the set values are stored in the first predetermined storage area of the shared RAM 32. It is.
• the NC device 1 When the talent reader operates the registration key of the MDI / CRT 33, the NC device 1 The setting molding condition set and stored in the first predetermined storage area is held in the area, and is transferred and stored in the second predetermined storage area of the shared RAM 32. Then, the injection molding machine is to execute the injection molding cycle according to the stored set molding conditions.
• FIG. 1 the injection motor control executed by the injection molding machine having the above configuration will be described with reference to FIGS. 1 and 2.
• FIG. 1 is a diagrammatic representation of the injection motor control executed by the injection molding machine having the above configuration.
• the concept of the emission motor control according to one embodiment of the present invention will be described with reference to FIG.
• the injection motor, the injection motor driven by the injection motor 3, and the pressure holding and pressure measurement are performed. It is assumed that the operation and the mold opening operation performed by the mold clamping device are performed.
• the injection motor 3 has a very small drive current flowing during injection, weighing and kneading, and a very large drive current during holding pressure. Flowing.
• the integral value of the ripening amount due to the drive current flowing to the injection motor 3 during one injection molding cycle is approximated by the integral value of the ripening amount due to the drive current flowing during the holding pressure. it can .
• the continuous rated current of the injection motor 3 is the maximum torque output.
• the motor drive current is proportional to the motor output torque ⁇ . Therefore, the continuous rated current is at the maximum torque output.
• the pressure is proportional to the generated pressure.
• the sum of the injection molding cycle time that is, the mold closing time CT, the injection time IT, the set holding pressure time HT i, the set cold time ET, and the mold opening time 0 T are the sum of The value DT + ⁇ HT i + ET never exceeds ⁇ .
• DT is the minimum dry cycle time, that is, the sum of the two when the mold closing rush GT and the mold opening time OT are determined by the mechanical configuration of the injection molding machine. Represents the minimum value of. Note that the injection time takes a very small value compared to other time parameters CT and the like.
• the amount of heat generated by the drive current when the drive current flows equal to the continuous rated current over one injection molding cycle is equal to the generated pressure MP at the time of the maximum torque output of the injection motor 3.
• the value obtained by multiplying the value obtained by squaring the value obtained by multiplying the proportional constant by the sum of the set dwell time ⁇ ⁇ Ti, the set cold S3 time ET, and the minimum dry cycle time DT Can be approximated to the safety side.
• This embodiment pays attention to the above points, and when the injection motor 3 is operated under the injection molding condition that is set to a different value, the motor is over-ripened.
• the feature is that it is determined in advance as to whether or not it is described below.
• ⁇ The integrated value of the amount of heat generated by the drive current during the injection molding cycle is Judge whether the ripening amount exceeds the allowable integral value when the continuous rated current flows. Then, in order to make this determination, the product of the value obtained by squaring the set dwell pressure HP i for each dwell stage of the injection molding cycle and the set dwell time ⁇ ⁇ ⁇ Sum ⁇
• FIG. 1 shows an overripening prevention control program executed by a PMC CPU 20 for controlling an injection motor according to an embodiment of the present invention.
• the program is, for example, an operator.
• the setting key of MDI / CRT 33 is operated, the injection condition setting mode is displayed, and the molding condition setting screen is displayed. It is executed periodically at that time.
• the CPU 20 monitors the operation state of the operation panel of the MDIZCRT 33 in the injection molding condition setting mode while the injection molding cycle is being executed or stopped, and the injection molding cycle is performed.
• the pressure operation and the pressure-holding time and the cooling time are all newly set or changed. It is determined whether or not it has been performed (step S1 to step S3).
• the set pressure HP i (HP It is determined whether any of the errors 1 to 3) has been input (Step S ⁇ ). If there is no input, it is determined whether or not the set value HT i of the dwell time has been input. Is determined (step S2), and if there is no such input, it is determined whether or not the set value ET of the cold SI time has been input (step S3). Then, if there is no input under any of the injection molding conditions, the program ends.
• the PMC CPU 20 follows the control program (not shown) according to the shared RAM. 32 The contents of the memory in the first predetermined memory area of 2 are rewritten only according to the above set values, and are also applied to steps S1 to S3 of the program. Detect the input operation of.
• step S4 the program shifts to step S4, and the CPU 20 sets the holding pressure time from the first predetermined storage area of the shared RAM 32 to the holding pressure HP.
• ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ Reads the cold time ⁇ PM, and reads the minimum dry cycle time D ⁇ and the maximum pressure from the R0 ⁇ 2 PM on the PMC ⁇ CPU 20 side.
• step S5 the sum of the product of the value obtained by squaring the set dwell pressure and the set dwell time and the pressure generated at the time of the maximum torque output of the injection motor 3 are calculated.
• the CPU 20 determines whether or not the ratio thus calculated exceeds a predetermined allowable ratio Rmax (step S6).
• step S7 If the calculated ratio R exceeds the predetermined allowable ratio Rmax, immediately when the injection motor 3 is operated under the new molding conditions to be set, the motor is activated. If it is overheated, the CPU 20 will write a warning message such as “The injection motor may be overripened,” which is stored in the ROM 21 in advance. As a warning output Example ⁇ ⁇ Display at a predetermined part of the molding condition setting screen (step S7). This ends the program. On the other hand, in step S6, if it is determined that the calculated ratio R is larger than the allowable ratio Rmax, the CPU 20 stores the information in the “injection mode” that has been stored in a weekly manner. Display an acceptable message such as “The data is too mature.” (Step S8), and terminate this program.
• the ratio R is calculated each time the talent writer inputs the set value of the molding condition, and the molding condition to be newly set is determined by the injection motor 3.
• the display indicates whether the operation is acceptable. After inputting all the newly set values, the alerter will warn the user to avoid setting inappropriate injection molding conditions carelessly. Check if the message is displayed. If the warning message does not go away, change the set value of the dwelling pressure and dwelling time to a slightly smaller value, or change the dwelling time of the dwelling time. After changing the set value to a larger value, check if a warning message is still displayed, and change the set value until the display disappears.
• the above-mentioned permissible message will be displayed instead of a warning message, and the talent collector will confirm this and register MDIZCRT 33.
• the setting molding conditions set in the first predetermined storage area of the shared RAM 32 are transferred and stored in the second predetermined storage area of the shared RAM 32.
• an appropriate injection molding cycle is executed without the injection motor 3 becoming over-ripened. You can simply delete the warning message in step S8.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Injection Moulding Of Plastics Or The Like (AREA)
• Stopping Of Electric Motors (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=15600112

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (16)

Citations (1)

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• 1986
  • 1986-07-03 JP JP61155174A patent/JPS6311320A/ja active Granted
• 1987
  • 1987-06-23 DE DE8787904110T patent/DE3772183D1/de not_active Expired - Lifetime
  • 1987-06-23 US US07/163,817 patent/US4847023A/en not_active Expired - Lifetime
  • 1987-06-23 WO PCT/JP1987/000413 patent/WO1988000123A1/ja not_active Ceased
  • 1987-06-23 EP EP87904110A patent/EP0273981B1/en not_active Expired

Patent Citations (1)

Non-Patent Citations (1)

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