JP4865515B2 - Molding machine - Google Patents

Description

  The present invention relates to a molding machine such as an injection molding machine or a die casting machine, and more particularly to a molding machine in which a movable die plate on which a movable mold is mounted is moved forward and backward by a driving force of a servo motor.

  Molding machines such as injection molding machines are shifting to electric molding machines that are clean and free of oil stains compared to hydraulic machines. In such electric molding machines, such as electric injection molding machines, The mold can be opened and closed by moving the movable die plate carrying the movable die forward and backward with respect to the fixed die plate carrying the fixed die by the drive force of the servo motor (electric servo motor for mold opening and closing). To do.

  In the electric molding machine as described above, a servo motor for opening and closing the mold is assumed on the assumption that the user uses a mold having a weight range recommended by the manufacturer as the movable mold to be mounted on the movable die plate. Generally, the manufacturer side uniquely sets the drive control conditions such as gain (servo gain) and acceleration / deceleration conditions at the time of shipment of the molding machine.

  By the way, there is a demand for the molding machine user who purchased the molding machine to use a mold outside the weight range recommended by the manufacturer, and the die plate (movable die plate and fixed die plate) is a manufacturer. Since it is possible to mount a mold outside the weight range recommended by the manufacturer, for example, a mold with a weight more than twice the mold weight set by the manufacturer as the standard weight is mounted on the die plate and molded. There was a short period of time. In such a case, the servo motor gain and acceleration / deceleration control conditions are set to be optimal when the above-mentioned standard weight mold is mounted. It was unreliable. In other words, the weight of the movable die mounted on the movable die plate is too large for the set gain for opening and closing the mold and the acceleration / deceleration control conditions, so the acceleration and deceleration performance is stable. In addition, there is a problem in that the time until stabilization (posture stabilization at the stop position) varies. In addition, since the mold opening / closing control is performed by force, the servo motor may oscillate.

  On the other hand, for example, it is conceivable to perform a molding operation by mounting a movable mold having a weight about ½ times the mold weight set by the manufacturer as a standard weight on a movable die plate. As described above, the gain and acceleration / deceleration control conditions for mold opening and closing are set to be optimal when a standard weight mold is mounted, so the mold is significantly lighter than the standard weight. On the other hand, it becomes a control condition with too much (excessive) specifications, and shortens the time from the start of driving the movable die plate to the stop of driving (that is, the time for mold opening, mold closing and clamping). Despite being able to plan, it has the problem that it is not realized.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a suitable mold opening / closing control in accordance with the mold weight even when a movable mold having an arbitrary weight is mounted on the movable die plate. The condition is to enable automatic setting.

In order to achieve the above-described object, the present invention provides a molding machine that opens and closes a mold by moving a movable die plate mounted with a movable mold forward and backward by a driving force of a servo motor.
Mold opening / closing control means for giving a drive command to a servo driver for driving the servo motor;
Control condition storage means for storing control conditions used by the mold opening / closing control means for mold opening / closing control during molding operation;
Candidate control condition storage means for storing a plurality of sets of candidate control conditions suitably determined according to the mold weight for storing in the control condition storage means;
By previously driving the movable die plate in which the movable molds corresponding to the candidate control conditions of each set stored in the candidate control condition storage unit are mounted based on predetermined test mold opening / closing control conditions Reference torque measurement data storage means for storing the obtained measurement torque data of the servo motor as reference measurement torque data in association with the candidate control conditions of each set;
Measurement torque data of the servo motor obtained by driving the movable die plate based on the predetermined test mold opening / closing control conditions in a state where a movable mold for actually forming is mounted, and the reference measurement torque By comparing the measured torque data for reference stored in advance in the data storage means, the measured torque data for reference that is closest to the measured torque data of the servo motor obtained by performing the test driving is specified, and this Control condition selection / setting means for storing the candidate control condition corresponding to the identified reference measurement torque data in the control condition storage means as a control condition when actually performing molding,
Take the configuration provided.

  In the present invention, in a state where the movable mold for actual molding is mounted on the movable die plate, the servo die is driven in a test operation based on a predetermined test mold opening / closing control condition by the servo motor. Acquire measured torque data, compare this measured torque data with a plurality of pre-stored reference measured torque data, identify the reference measured torque data closest to the measured torque data, and specify the specified reference Suitable candidate control conditions stored in advance corresponding to the measured torque data are automatically used as the control conditions for actual molding, so depending on the weight of the movable die mounted on the movable die plate It is possible to perform suitable mold opening / closing control.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 6 relate to an injection molding machine according to an embodiment of the present invention (hereinafter referred to as this embodiment), and FIG. 1 is a simplified diagram showing a mold opening / closing system mechanism of the injection molding machine of this embodiment. And it is the front view which fractured | ruptured one part.

  In FIG. 1, 1 is a fixed die plate fixed to an appropriate holding frame, 2 is a fixed side mold fixed to the fixed die plate 1, and 3 is a tailstock that holds a fixed position in a molding operation state. Reference numeral 4 denotes a plurality of tie bars connecting the fixed die plate 1 and the tail stock 3, and reference numeral 5 denotes a movable body that is inserted and guided by the tie bar 4 so as to move forward and backward between the fixed die plate 1 and the tail stock 3. The die plate 6 is a movable die fixed to the movable die plate 5, 7 is a mold opening / closing servo motor (electric servo motor for mold opening / closing) mounted on the tailstock 3, and 8 is a servo motor 7. A drive pulley 9 fixed to the output shaft of the ball screw mechanism 9 is a ball screw mechanism that converts the rotation of the servo motor 7 into a linear motion, and 10 is a ball screw mechanism 9 that is rotatably held by the tailstock 3. The nut body 11 is screwed to the nut body 10 and the screw shaft 12 of the ball screw mechanism 9 that moves forward and backward by the rotation of the nut body 10 is fixed to the nut body 10 to drive the rotation of the servo motor 7. A pulley 8 and a driven pulley 13 that is transmitted via a timing belt (not shown) connect the tailstock 3 and the movable die plate 5, and are driven to extend or fold when the screw shaft 11 of the ball screw mechanism 9 moves forward or backward. Thus, the toggle link mechanism moves the movable die plate 5 forward or backward.

  In the configuration shown in FIG. 1, although not shown, in the mold open state, the toggle link mechanism 13 is in the most folded state and the movable die plate 5 is in the most retracted mold closing start position (mold opening completion position). . When the servo motor 7 is rotationally driven in a predetermined direction from the mold open state, the nut body 10 of the ball screw mechanism 9 is rotationally driven through the driving pulley 8, the timing belt (not shown), and the driven pulley 12, thereby the ball screw As the screw shaft 11 of the mechanism 9 advances, the toggle link mechanism 13 is driven to extend, and the movable die plate 5 advances. Then, as the movable die plate 5 advances, the movable mold 6 touches the fixed mold 2, and the servomotor 7 is further rotated in the predetermined direction by a predetermined amount even after this mold touch. Thus, the toggle link mechanism 13 shifts to a fully extended state, whereby the mold clamping is completed and the rotation of the servo motor 7 is stopped. In the state where mold clamping is completed, the tie bar 4 is stretched and deformed by receiving a predetermined tensile load, and a predetermined mold clamping force is applied to both molds 2 and 6 by the elastic restoring force of the tie bar 4 to which the tensile load is applied. Is to be granted.

  At a predetermined timing after completion of mold clamping, a molten resin is injected and filled into a cavity (molding space) formed by both molds 2 and 6 by an injection unit (not shown), and a known pressure holding process and cooling process are performed. After that, mold opening is performed. In this mold opening, the servo motor 7 is rotationally driven in the opposite direction, and the nut body 10 of the ball screw mechanism 9 is opposite to the previous direction via the drive pulley 8, the timing belt (not shown), and the driven pulley 12. When the screw shaft 11 of the ball screw mechanism 9 is moved backward by this, the toggle link mechanism 13 is driven to be folded and the movable die plate 5 is moved backward, and the movable die plate 5 is moved to the mold opening completion position (mold closing start). The servo motor 7 stops rotating when it is retracted to the position), and the mold opening is completed.

  FIG. 2 is a block diagram showing the configuration of the mold opening / closing control system. In FIG. 2, 20 is a system controller that controls the overall control of the injection molding machine, and this system controller cooperates with hardware resources such as arithmetic functional elements and memory and software resources such as various application software held in advance. By the operation, various processing such as various arithmetic processing, data writing / calling processing, display control processing, command output processing and the like are executed. In FIG. 2, only the functional blocks related to the mold opening / closing control are depicted in the system controller 20, and the details of these functional blocks will be described later. Each functional block is based on the above hardware resources and software resources. The functional block in the system controller 20 may be implemented so that one functional block has a function that also serves as another functional block.

  In FIG. 2, reference numeral 31 denotes control target data given from the system controller 20 according to a command from the system controller 20, an output of an encoder (not shown) attached to the servo motor 7, and torque attached to the servo motor 7. A mold opening / closing control unit 33 that controls the drive of the servo motor 7 via the servo driver 32 based on the output of the detection unit 33 is attached to the servo motor 7, and the motor torque is calculated from the actual drive current value of the servo motor 7. The torque detector 34 measures the rotation of the servo motor 7 to the ball screw mechanism 9, and includes a reduction rotation transmission system (deceleration rotation transmission mechanism) composed of the drive pulley 8, a timing belt (not shown), and the driven pulley 12. Servo motor 7 → Deceleration and rotation transmission system 34 → Ball screw mechanism 9 → Toggle link In the transmission path of force of structure 13, the movable die plate 5 is driven forward or backward as described above.

  In the system controller 20, 21 is a general control unit that controls each unit in the system controller 20, and 22 is a control condition storage that stores control conditions used by the mold opening / closing control unit 31 for mold opening / closing control during molding operation. , 23 is a test mold opening / closing control condition storage section for storing control conditions used by the mold opening / closing control section 31 for mold opening / closing control during a test mold opening / closing operation described later, and 24 is a control condition storage section 22 or a test mold. Using the condition data of any one of the opening / closing control condition storage unit 23, the output of the encoder attached to the servo motor 7 and the torque detection unit are controlled under the control of the overall control unit 21 that grasps the operation state of each part of the machine. A control command value output unit that outputs control target data (command value) to the mold opening / closing control unit 31 while referring to the output of 33. The control condition storage unit 22 includes an encoder output pulse value required for mold closing and clamping, an encoder output pulse value required for mold opening, a speed / pressure control condition divided into mold closing sections, and a mold clamping pressure. In addition to the control conditions and speed / pressure control conditions divided into mold opening sections, servo gain conditions, acceleration conditions, deceleration conditions, and the like are stored. The test mold opening / closing control condition storage unit 23 includes an encoder output pulse value required for mold closing and clamping, an encoder output pulse value required for mold opening, speed / pressure control conditions divided into mold closing sections, mold clamping In addition to pressure control conditions, speed / pressure control conditions divided into mold opening sections, and test mold opening / closing frequency values, for example, standard servo gain conditions, acceleration conditions, deceleration conditions, etc. used in test mold opening / closing operations are stored. The

  In the system controller 20, reference numeral 25 denotes a candidate control condition storage unit that stores a plurality of sets of candidate control conditions that are suitably determined in accordance with the mold weight, for storage in the control condition storage unit 22. The movable die plate 5 on which the movable molds 6 corresponding to each set of candidate control conditions stored in the candidate control condition storage unit 25 are respectively mounted is stored in the test mold opening / closing control condition storage unit 23. The measured torque data for reference stored in the measured torque data for reference stored in correspondence with the candidate control conditions for each set of the measured torque data of the servo motor 7 obtained by performing mold opening / closing drive in advance based on the test mold opening / closing control conditions Data storage unit (The data stored in the reference measurement torque data storage unit does not need to be stored by performing a test-type opening / closing operation for each machine. 27, in which the machine (injection molding machine) 27 is mounted with the movable mold 6 that actually performs molding before the molding operation is performed by the user of the machine (injection molding machine). Measured torque data of the servo motor 7 obtained by the torque detector 33 by driving the movable die plate 5 based on predetermined test mold opening / closing control conditions stored in the test mold opening / closing control condition storage unit 23. The measured torque data holding unit 28 stores the measured torque data held by the measured torque data holding unit 27 and a plurality of types of reference measured torque data stored in advance in the reference measured torque data storage unit 26. Thus, the reference measurement torque data closest to the measurement torque data of the servo motor 7 obtained by opening and closing the test mold is specified, and the specified reference measurement torque is specified. The candidate control conditions corresponding to Kudeta is read from the candidate control condition storage unit 25, a control condition selection and setting means for storing and setting the control condition memory unit 22 as the control condition at the time of performing actual molding.

  Next, the automatic setting operation of the mold opening / closing control condition according to the present embodiment will be described with reference to FIGS. FIG. 3 is a flowchart showing the flow of the control condition storage / setting process to the control condition storage unit 22 in the present embodiment, and FIG. 4 is an explanatory diagram schematically showing the data process.

  First, before performing the molding operation, the movable die 6 used in the next molding operation is mounted on the movable die plate 5, and the predetermined test mold stored in the test mold opening / closing control condition storage unit 23 in step S1. Based on the opening / closing control conditions, the movable die plate 5 is driven to open / close the test die (ie, the die opening / closing drive is performed a plurality of times), and the measured torque data of the servo motor 7 measured by the torque detector 33 is acquired to The data holding unit 27 stores the measured torque data of the test type opening / closing operation for a plurality of times. The measured torque data to be acquired may be data only for the mold closing / clamping process, data for only the mold opening process, or data for both the mold closing / clamping process and the mold opening process. Good. In the present embodiment, under the control of the overall control unit 21, the average value of the measured torque data of a plurality of test mold opening / closing operations, that is, the measured torque of the mold closing / clamping process of the plurality of test mold opening / closing operations. The average value of the data and / or the average value of the measured torque data in the mold opening process of the test mold opening / closing operation for a plurality of times are obtained by an appropriate arithmetic processing function unit (not shown), and the measured torque data holding unit 27 To memorize. FIG. 4A shows an example of a pattern (graphic pattern) based on the measured torque data of the average value of the mold opening process stored in the measured torque data holding unit 27.

  Next, in step S <b> 2, the control condition selection / setting unit 28 stores the average measured torque data pattern (graphic pattern) stored in the measured torque data holding unit 27 and the reference measured torque data storage unit 26. By comparing each pattern (each graphic pattern) with a plurality of kinds of reference measurement torque data stored in advance, that is, an average value of the mold closing / clamping process stored in the measurement torque data holding unit 27 The pattern based on the measured torque data is compared with the patterns based on the measured torque data for reference in a plurality of types of mold closing / clamping processes stored in advance in the reference measured torque data storage unit 26, or the measured torque data is held. The pattern based on the measured torque data of the average value of the mold opening process stored in the unit 27 and the reference meter The patterns of the plurality of types of mold opening processes stored in advance in the torque data storage unit 26 are compared with the patterns based on the reference measurement torque data, or the mold closing / clamping process stored in the measured torque data holding unit 27 is performed. The pattern based on the average measured torque data and the pattern based on the average measured torque data of the mold opening process, and the reference measurement of the plural types of mold closing / clamping processes stored in advance in the reference measured torque data storage unit 26 By comparing each pattern based on the torque data and each pattern based on the measured torque data for reference in a plurality of types of mold opening processes, the pattern based on the measured torque data for reference that is most similar to the pattern based on the measured torque data is specified. FIG. 4B shows an example of a pattern of the mold opening process based on the reference measurement torque data. Here, in the reference measurement torque data storage unit 26, the mold weight is large, medium, or small. Three types of reference measurement torque data are stored, and (1) in FIG. 4B is a pattern based on the reference measurement torque data in the mold opening process corresponding to a small mold weight, and (b) in FIG. (2) in FIG. 4 is a pattern based on the reference measurement torque data for the mold opening process corresponding to the mold weight, and (3) in FIG. 4B is a reference to the mold opening process corresponding to a large mold weight. Examples of patterns based on measured torque data are shown. The number of reference measurement torque data for the mold closing / clamping process and / or the number of reference measurement torque data for the mold opening process stored in advance in the reference measurement torque data storage unit 26 is four types. Needless to say, the number may be any number as described above. In the pattern comparison process performed by the control condition selection / setting unit 28, the degree of approximation between patterns is determined by comparing the peak waveform, peak level, etc. of the graphic pattern. Techniques can be adopted.

  Next, in step S3, the control condition selection / setting unit 28 sets candidate control conditions optimized according to the mold weight corresponding to the reference measurement torque data specified in step S2 to the candidate control condition storage unit 25. Is stored and set in the control condition storage unit 22 as a control condition for actual molding. In the example shown in FIG. 4, it is determined that the pattern (reference measurement torque data) in (b) of FIG. 4 is closest to the measurement torque data in the test-type opening / closing operation. The candidate control condition 41 corresponding to the pattern (2) (reference measurement torque data) of (b) is set in the control condition storage unit 22. Here, the data items included in the candidate control conditions include at least servo gain conditions, acceleration conditions, and deceleration conditions, which are stored and set in the form of constants used for calculation of each condition control in this embodiment. It has come to be.

  As described above, in the present embodiment, by performing the test mold opening / closing operation based on the predetermined test mold opening / closing control conditions in a state where the movable mold 6 to be actually molded is mounted on the movable die plate 5, The measurement torque data of the servo motor 7 is acquired, the measurement torque data is compared with a plurality of reference measurement torque data stored in advance, and the reference measurement torque data closest to the measurement torque data is specified, Since a suitable candidate control condition stored in advance corresponding to the specified reference measurement torque data is automatically used as a control condition when actually forming, the movable side plate mounted on the movable die plate 5 is used. Suitable mold opening / closing control according to the weight of the mold 6 can be performed. Therefore, for example, even when a mold with a weight more than twice the mold weight set by the manufacturer as a standard weight is mounted on the movable die plate 5, the standard weight mold is mounted for the time required to open and close the mold. However, the acceleration and deceleration performance is stable and no overshoot occurs, and the time until stabilization (posture stabilization at the stop position) is also constant (stabilized). In addition, for example, when a mold having a weight that is about ½ times the weight of the mold set by the manufacturer as a standard weight is mounted on the movable die plate 5, the acceleration and deceleration curves can be sharpened, and the mold opening and closing can be performed. The time can be shortened, and the time until settling can be made constant.

It is the front view which simplified and showed one part fracture | rupture which shows the type | mold opening-and-closing system mechanism in the injection molding machine which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of the mold opening / closing control system in the injection molding machine which concerns on one Embodiment of this invention. It is a flowchart which shows the processing flow of the automatic setting of the mold opening / closing control conditions in the injection molding machine which concerns on one Embodiment of this invention. It is explanatory drawing which shows typically the data processing for the automatic setting of the mold opening / closing control conditions in the injection molding machine which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed die plate 2 Fixed side metal mold 3 Tail stock 4 Tie bar 5 Movable die plate 6 Movable side metal mold 7 Servo motor for mold opening / closing 8 Drive pulley 9 Ball screw mechanism 10 Nut body 11 Screw shaft 12 Driven pulley 13 Toggle link mechanism 20 System controller 21 Overall control unit 22 Control condition storage unit 23 Test type opening / closing control condition storage unit 24 Control command value output unit 25 Candidate control condition storage unit 26 Reference measurement torque data storage unit 27 Measurement torque data holding unit 28 Control condition selection / Setting means 31 Mold opening / closing control unit 32 Servo driver 33 Torque detection unit 34 Deceleration rotation transmission system

Claims (3)

In a molding machine that opens and closes a mold by moving a movable die plate mounted with a movable mold back and forth with the driving force of a servo motor.
Mold opening / closing control means for giving a drive command to a servo driver for driving the servo motor;
Control condition storage means for storing control conditions used by the mold opening / closing control means for mold opening / closing control during molding operation;
Candidate control condition storage means for storing a plurality of sets of candidate control conditions suitably determined according to the mold weight for storing in the control condition storage means;
By previously driving the movable die plate in which the movable molds corresponding to the candidate control conditions of each set stored in the candidate control condition storage unit are mounted based on predetermined test mold opening / closing control conditions Reference torque measurement data storage means for storing the obtained measurement torque data of the servo motor as reference measurement torque data in association with the candidate control conditions of each set;
Measurement torque data of the servo motor obtained by driving the movable die plate based on the predetermined test mold opening / closing control conditions in a state where a movable mold for actually forming is mounted, and the reference measurement torque By comparing the measured torque data for reference stored in advance in the data storage means, the measured torque data for reference that is closest to the measured torque data of the servo motor obtained by performing the test driving is specified, and this Control condition selection / setting means for storing the candidate control condition corresponding to the identified reference measurement torque data in the control condition storage means as a control condition when actually performing molding,
A molding machine characterized by comprising. The molding machine according to claim 1,
The molding machine characterized in that the control conditions stored in the control condition storage means by the control condition selection / setting means are at least a gain condition, an acceleration condition, and a deceleration condition. The molding machine according to claim 1,
The control condition selection / setting means compares the torque data patterns from the start of driving to the stop of driving of the movable die plate, thereby making the reference closest to the measured torque data of the servo motor obtained by driving the test drive. A molding machine characterized by performing a determination process for specifying measured torque data.

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