JP5518565B2 - Method for controlling molding machine and molding machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a molding machine control method and a molding machine in which a rotating disk to which a mold is attached is rotatably provided by an electric motor.

  As a molding machine in which a rotating plate to which a mold is attached is provided so as to be rotatable by an electric motor, those described in Patent Document 1 to Patent Document 3 are known. In Patent Document 1, a rotating plate (rotating plate) is attached to a movable plate of a horizontal injection molding machine. Further, Patent Document 2 discloses a mold half support (rotation) which is rotated between a fixed mold clamping plate and a movable mold clamping plate in a horizontal injection molding machine about an axis perpendicular to the mold opening / closing direction. Board), and another mold half (mold) is attached to both surfaces of the mold half support. In Patent Document 3, a rotating plate is attached to a movable plate of a vertical injection molding machine. In these injection molding machines, in order to shorten the molding cycle, it is preferable to improve the rotation speed of the rotating disk. In order to improve the rotation speed of the rotating disk, it may be possible to make the electric motor for rotating the rotating disk have a large rated output, but this leads to an increase in cost.

  In these injection molding machines, the mold attached to the turntable and the mold on the opposite board surface side are exchanged according to the molded product, and the weight of the mold varies depending on the exchange of the mold. The weight of the mold to be attached also affects the rotational speed of the rotating disk and the load of the electric motor. Conventionally, however, it has been difficult to obtain an optimum rotational speed for each attached mold, and in most cases, all molds are rotated at the same rotational speed. Further, in Patent Document 3, the weight of the moving body is calculated and calculated by detecting the hydraulic pressure of the mold opening chamber of the mold opening / closing device, and the rotation speed is changed according to the calculated weight of the moving body. Also, in Patent Document 3, when the mold opening / closing mechanism uses a servo motor, the current value during operation is detected, the mold weight is calculated, and the rotating disc is calculated according to the calculated weight of the moving body. The rotation speed is changed.

JP 2001-162642 A (Claim 1, FIG. 1) JP-A-11-105072 (Claim 1, FIG. 1) JP 2002-321262 A (Claim 1, 0015, FIG. 2)

  However, in the control method of Patent Document 3, since it is unclear how much load is actually applied to the motor when rotating the rotating disk, it is appropriate within a range in which an excessive load is not applied to the motor according to the mold weight. There was a problem that it was difficult to achieve a rotational speed. Also, the load on the motor when the rotating disk rotates is not only the weight of the rotating disk including the mold, but also the mold shape, mold mounting position (distance from the shaft center), temperature, wear degree of the rotating mechanism, etc. Therefore, even if the weight could be detected accurately, it was unclear whether it would directly affect the setting of the optimum rotational speed. Furthermore, the relationship between the speed curve during rotation of the rotating disk and the load on the motor is unclear, and there is a possibility that the speed curve is not appropriate.

  In the present invention, in view of the above problems, in a molding machine in which a rotating plate to which a mold is attached is provided so as to be rotatable by an electric motor, even if the die attached to the rotating plate is changed, the rotating plate is rotated at an appropriate rotational speed. It is an object of the present invention to provide a molding machine control method and a molding machine that can be rotated or prevented from being damaged or shortened in service life of an electric motor or the like.

According to a first aspect of the present invention, there is provided a molding machine control method comprising: a molding machine control method in which a rotating plate provided with a mold is rotatably provided by an electric motor; and the rotational speed of the rotating plate is settable. Detecting the peak torque of the motor during acceleration or deceleration of the rotation of the rotating disk, and generating an alarm signal when it is detected that the peak torque exceeds a predetermined value or exceeds a predetermined value a plurality of times. A warning message is issued so as to change the rotation speed of the turntable to the low speed side .

According to a second aspect of the present invention, there is provided a molding machine control method according to a molding machine control method in which a rotating plate provided with a mold is rotatably provided by an electric motor, wherein the rotational speed of the rotating plate is settable. The peak torque of the motor at the time of acceleration or deceleration of rotation of the rotating disk is obtained by detection, and when it is detected that the detected value of the peak torque is a predetermined value more than a predetermined value or exceeding a predetermined value, a plurality of times . The rotation speed or the rotation time of the rotating disk is controlled so that the peak torque of the motor at the time of acceleration or deceleration of the rotating disk is lower than a predetermined value or lower than a predetermined value.

According to a third aspect of the present invention, there is provided a molding machine control method according to the first or second aspect, wherein the peak torque during acceleration and the peak during deceleration when the rotating disk is rotated forward 180 degrees in the forward direction. Detecting torque and peak torque during acceleration and deceleration when decelerating 180 degrees in the reverse direction in the next molding, respectively.

According to a fourth aspect of the present invention, there is provided a molding machine in which a rotating disk provided with a mold is rotatably provided by an electric motor, the rotational speed of the rotating disk is settable, and the rotation of the rotating disk is controlled. the torque of the electric motor detects the peak torque during acceleration or deceleration, a plurality of times said peak torque, when exceeding a predetermined value or more or a predetermined value set, an alarm signal, the rotational speed of the rotating disk low speed side It is characterized by issuing a warning message to change to .

A molding machine control method and a molding machine according to the present invention are provided in a molding machine control method in which a rotating disk provided with a mold is rotatably provided by an electric motor. detects the peak torque of the electric motor during acceleration or deceleration of rotation, the peak torque multiple times, when it is detected that exceeds a predetermined value or more or a predetermined value set, an alarm signal, the rotating disk A warning message is issued to change the rotation speed of the machine to the low speed side, so even if the mold attached to the turntable is changed, the turntable can be rotated at an appropriate rotation speed, or to a servo motor or reducer. Can always be within an appropriate range.

It is a front view of the vertical rotary injection molding machine of this embodiment. It is the figure which looked at the turntable and upper movable metal mold | die of the vertical rotary molding machine of this embodiment from the downward direction. It is a block diagram which shows the control system of the servomotor of this embodiment. It is a figure which shows the rotational speed and torque of the servomotor for rotating disk rotation at the time of rotation of the rotating disk of the vertical rotary molding machine of this embodiment (at the time of normal rotation). It is a figure which shows the rotational speed and torque of the servo motor for rotating disk rotation at the time of reverse rotation of the rotating disk of the vertical rotary molding machine of this embodiment.

A vertical rotary injection molding machine 11 according to an embodiment of the present invention will be described with reference to FIG. A vertical rotary injection molding machine 11, which is a type of molding machine, is composed of a mold clamping device 12 and a first injection device 13 and a second injection device 14 provided on both sides thereof. In the mold clamping device 12, four tie bars 16 are fixed in an upright direction on a fixed plate 15 provided below, and an upper plate 17 is fixed above the tie bar 16. A movable platen 18 is inserted through the tie bar 16, and the movable platen 18 is movable in the vertical direction. A mold clamping cylinder 19 is provided on the upper board 17, and a ram 20 of the mold clamping cylinder 19 is fixed to the back surface of the movable board 18. A mold opening / closing mechanism (not shown) is provided between the upper board 17 and the movable board 18. The mold opening / closing mechanism may use a servo motor and a ball screw mechanism, or may use a hydraulic cylinder.

As shown in FIGS. 1 and 2, a disk-shaped rotating disk 21 (rotary table) having a certain thickness is rotatably attached to the lower surface of the movable disk 18. A central shaft 22 is fixed upward at the center of the rotary plate 21, and the central shaft 22 is supported by a bearing or the like provided on the movable plate 18. A servo motor 23 that is an electric motor for rotating the rotating disk is attached to the side of the movable panel 18. A timing belt 26 is stretched around a toothed pulley 25 fixed to the drive shaft 24 of the servomotor 23 and a toothed portion of the outer peripheral surface 28 of the rotating disk 21. The timing belt 26 is stretched by a tension pulley 27 provided on the movable platen 18 to prevent the timing belt 26 from skipping teeth. The drive shaft 24 and the rotating disk 21 of the servo motor 23 may be one in which a driving force is transmitted to the outer periphery of the rotating disk 21 by a gear mechanism, and a timing belt or a gear mechanism is used for the central axis of the rotating disk 21. A driving force may be transmitted by a reduction mechanism. In the type using a reduction gear, it is necessary to consider the load capacity of the reduction gear in addition to the electric motor. The electric motor used in the molding machine is preferably a servo motor 23, but may be another motor.

  Upper movable molds 29 a and 29 b are respectively attached to the lower surface of the turntable 21 by mold clampers at opposite positions spaced apart from the axis of the turntable 21. In addition, two lower fixed molds 30a and 30b corresponding to the upper movable molds 29a and 29b are attached to the upper surface of the lower fixed platen 15 by a mold clamper. The number of molds attached to the turntable 21 or the opposing board is not limited to two, and may be one or more than three. Further, a positioning engagement pin (not shown) for fixing the rotation of the rotating plate 21 is provided between the rotating plate 21 and the movable plate 18 so as to advance and retract.

Next, the control system of the servo motor 23 will be described with reference to the block diagram of FIG. The control device 31 of the vertical rotary injection molding machine 11 is a controller that controls the entire molding machine. The control device 31 is connected via an input unit 33 and an output unit 34 to a setting display unit 32 that inputs various numerical values and displays data of the molding machine. Further, the control device 31 is provided with a speed command unit 35 that commands the rotation speed of the servo motor 23, and is connected to the speed command unit 35 from the setting display unit 32 via the input unit 33. Other data such as rotational speed (including acceleration / deceleration time) and gain are stored in the condition storage unit 36, and a speed command is issued based on these conditions. In addition, a torque value or the like of the servomotor 23 is sent to the input unit 33 from a servo amplifier 37 described later. Based on the detected value such as the torque value, the calculation unit (torque monitoring unit) 38 makes a comparison, and an alarm signal message is generated and displayed on the setting display unit 32 via the output unit 34.

The control device 31 is connected to a servo amplifier 37 that is a driver of the servo motor 23. A speed command signal is sent to the servo amplifier 37 from the speed command unit 35 of the control device 31 (only the speed command is displayed for explanation), and feedback control is performed together with the signal from the encoder 42 of the servo motor 23 to set the speed. A speed signal is generated by the unit 39, and a current sent from the power conversion unit 40 to the servo motor 23 is output. The current value of the current is detected by the current detector 41 and feedback controlled in the servo amplifier 37. The current value is also sent to the input unit 33 of the control device 31 as a torque value.

In the present embodiment, the rotation speed of the rotating disk 21 that is input from the setting display unit 32 and stored in the condition storage unit 36 is three stages of “high speed”, “standard”, and “low speed”. However, the rotational speed stage may be further finely provided. When accelerating (starting) or decelerating (stopping) rotation, prepare many changes in the pattern of acceleration, etc. during rotation, such as by providing a low-speed section at the beginning or just before stopping. May be. Furthermore, stepless rotation speed (or rotation time), time to reach the highest speed in the acceleration section (or acceleration), time from the highest speed to the stop in the deceleration section (acceleration during deceleration), etc. It is possible to input settings and save them. In consideration of the load on the servo motor 23 and the speed reducer, the rotation speed of the rotating disk 21 is important for acceleration and deceleration, so the intermediate speed is within the capability of the servo motor 23. The speed may be controlled by the fastest method. By doing so, it is possible to reduce the load on the servo motor 23 and the like by optimizing the acceleration at the time of acceleration and deceleration which are problematic.

Next, molding of the vertical rotary injection molding machine 11 of this embodiment will be described. First, when molding of a certain molded product is completed and the process proceeds to molding of the next molded product, the mold is exchanged. In the mold exchange, the molds removed from the molding machine are set up and down, taken out from one side of the molding machine in the horizontal direction, and then a new set of upper and lower molds are carried onto the fixed platen 15 and the movable platen including the turntable 21 is moved. The board 18 is lowered. The lower fixed molds 30a and 30b are attached to the fixed platen 15, and the upper movable molds 29a and 29b are attached to the rotary platen 21 by a mold clamper (not shown).

Various molding conditions are input or set, and molding is started. First, the movable platen 18 is lowered by a mold opening / closing mechanism (not shown) and clamped by a mold clamping cylinder 19, and then one cavity between one lower fixed mold 30a and one upper movable mold 29a from the first injection device 13. The molten resin is injected into the primary molded product. Also, the molten resin is injected from the second injection device 14 into the other cavity between the other lower fixed mold 30b and the upper movable mold 29b, and secondary molding is performed. Next, the mold clamping is released, and the movable platen 18 is again moved upward by the die opening / closing mechanism, the servomotor 23 for rotating the rotary plate is operated, and the rotary plate 21 is rotated 180 degrees (forward rotation). As a result, the primary molded product released from the state of adhering to the upper movable mold 29a is moved to the other secondary side. Then, the positions of the movable platen 18 and the rotary platen 21 are fixed by the positioning engagement pins. The movable platen 18 is lowered again to perform mold clamping, and primary molding is performed in the one cavity, and secondary molding is performed in addition to the primary molded product in the other cavity. Then, in the next mold opening, the secondary molded product is taken out, this time, the positioning engagement pin is removed, and the rotating disk 21 is rotated 180 ° (reversely) in the opposite direction to the previous one and returned to the original position. The positioning engagement pin is engaged again.

Next, the relationship between the rotational speed control of the rotating disk 21 by the servo motor 23 for rotating the rotating disk and the torque (speed torque) will be described with reference to FIG. The torque of the servo motor 23 is obtained by actually measuring the current value sent from the power conversion unit 40 to the servo motor 23. The torque of the servo motor 23 may be obtained by calculation by measuring a speed command signal or a torque command signal (voltage value) sent from the control device 31 to the servo amplifier 37, or may be other known torque detecting means. . With respect to the rotation of the rotating table 21 and the upper driving molds 29a and 29b, which are heavy objects, the current value sent to the servomotor 23 is highest when the motor is started and accelerated, and the peak torque pt1 is generated. Thereafter, the torque decreases in the high speed section, and the peak torque pt2 is generated at the time of deceleration for decelerating and stopping the rotation of the turntable 21 as in acceleration. Therefore, by detecting the peak torques pt1 and pt2 and keeping them within a predetermined range, it is possible to reduce the load on the servomotor 23 and its reduction gear.

In the present embodiment, the values of the detected peak torques pt1 and pt2 are transmitted to the control device 31, and are monitored torque values (Sys values) stored in the condition storage unit 36 by the calculation unit (torque monitoring unit) 38. Is compared. In the present embodiment, 50% of the maximum allowable peak torque value determined for each servomotor 23 is the monitored torque value (Sys value) (predetermined value). When the calculation unit (torque monitoring unit) 38 confirms that one of the detected peak torques pt1 and pt2 exceeds the monitored torque value (Sys value), for example, three times, the calculation unit ( Torque monitoring unit 38 issues an alarm signal that the predetermined value has been exceeded. The alarm signal is sent from the control device 31 to the setting display unit 32 and issues a warning message to the setting display unit 32. As an example of a warning message, if the peak torque pt1 during acceleration exceeds, “The servo motor torque during table rotation acceleration operation is the limit. Change the molding pattern surface acceleration time setting to standard or low speed. Please lower the table rotation speed setting on the molding pattern screen. " Then, the operator who sees it changes the rotation speed of the turntable 21 from “high speed” to “standard”, for example. A warning message is similarly displayed when the peak torque pt2 during deceleration exceeds, and the operator changes the rotation speed.

The alarm signal and the warning message are not limited to the case where either one of the peak torques pt1 or pt2 exceeds the monitored torque value (Sys value) (predetermined value) three times. You may make it come out at the time. In addition, the operator may correct only the acceleration / deceleration time (acceleration) when the warning message at the time of acceleration or deceleration is issued (in particular, when using a speed reducer, the peak torque during acceleration is generally used). pt1 is larger than the peak torque pt2 during deceleration). Further, an alarm sound may be generated based on an alarm signal from the control device 31. Further, based on an alarm signal, the detected peak torques pt1 and pt2 are automatically controlled to a rotational speed (or rotational time) within 50% as an example of an allowable peak torque value, or the molding machine is stopped urgently. Good. In addition to the peak torques pt1 and pt2, if the servo motor 23 or the speed reducer can be detected to be in an overload state, the average torque in a certain time during acceleration or deceleration is used. It may be detected that the value (or integrated value) exceeds a predetermined value. Alternatively, an alarm signal may be generated by detecting that the peak torques pt1, pt2, etc. of the servo motor 23 have reached or exceeded a predetermined value (including a predetermined value).

In the present embodiment, the rotating plate 21 and the upper movable dies 29a and 29b rotated in the forward direction (0 ° → 180 °) as shown in FIG. 4 in the first molding are shown in FIG. Rotated in the reverse direction (180 ° → 0 °) as shown in FIG. However, since the same peak torques pt3 and pt4 are detected when the turntable 21 is rotated in the reverse direction (180 ° → 0 °), the peak torques pt3 and pt4 are detected in the same manner as described above, and the peak torque is detected. Control is performed to issue an alarm signal when pt3 or pt4 reaches a set predetermined value or exceeds a set predetermined value.

Alternatively, as another method for controlling the rotation speed of the turntable 21, the rotation speed (or rotation time) of the turntable 21 may be automatically set instead of being operated by the operator. In this case, first, automatic setting such as the rotation speed of the turntable 21 is performed before starting molding. The acceleration / deceleration automatic setting mode switch on the screen of the setting display section 32 is turned on to rotate the rotating disk 21. First, the turntable 21 is rotated with the slowest acceleration time and deceleration time (system value) or the slowest acceleration (deceleration). If the peak torques pt1 and pt2 are not present during acceleration or deceleration, or if the peak torques pt1 and pt2 are considerably smaller than 50% of the maximum allowable peak torque value, the acceleration / deceleration time is automatically shortened. Then, an acceleration time and a deceleration time at which the peak torques pt1 and pt2 are 50% of the maximum allowable peak torque value are obtained. Then, a preset time (system value) is added thereto, and an acceleration time and a deceleration time for rotating the turntable 21 at the time of molding are calculated, stored in the condition storage unit 36 of the control device 31, and used at the time of molding. Since these operations are performed automatically, the operator can perform another operation, and the operation time can be shortened with respect to the setting of the rotation speed. In these automatic setting methods before molding, a trial may be started first from the “high speed” or “standard” mode, the peak torques pt1 and pt2 are detected, and the rotational speed may be changed.

Further, the acceleration / deceleration time that would be the desired peak torque pt1, pt2 value (50% as an example) is calculated from the detected values of the peak torques pt1, pt2, by simulation, and the turntable 21 is rotated by the acceleration time or the deceleration time. You may make it. Accordingly, even when the rotational speed is automatically obtained, the rotational speed (acceleration) may be obtained so that the torque of the servo motor 23 is lower than a predetermined value, and may be less than a predetermined value (including those set to a predetermined value). The rotational speed (acceleration) may be obtained so that the primary molded product is attached to the mold before and during molding, and the friction caused by thermal expansion of the movable platen 18 and the rotary platen 21. It should be taken into account that there may be a slight difference between both peak torques pt1 and pt2 due to changes in the coefficient and the like.

Or the peak torque pt1, pt2, etc. that would be generated from the set value or measured value of the rotational speed (rotation time), acceleration (acceleration time), acceleration during deceleration (deceleration time), mold weight, etc. Is calculated by the calculation unit 38, and it is compared whether or not the peak torques pt1, pt2, etc. are lower than the predetermined value or lower than the predetermined value with respect to the allowable peak torque, and the rotation speed is automatically calculated based on the comparison result. Or you may correct | amend manually.

Further, in the present embodiment, the rotating disk 21 has been described as rotating 180 degrees and then rotating 180 degrees, but all may be continuously rotated in the forward direction. In addition, depending on the number of molds attached to the turntable 21, the turntable 21 may be rotated 120 ° or 90 ° at a time. Further, the example in which the turntable 21 to which the mold is attached is rotatably attached to the upper movable platen 18 has been described, but the turntable can be mounted on any of the upper fixed platen, the lower movable platen, and the lower fixed platen. May be attached. Further, in the present embodiment, the number of molds on the board side facing the rotating board 21 is the same, but it may be different. Further, the number of injection devices is not limited. For example, after setting the insert on the first stage, the rotating disk may be rotated to move to the molding position and injection may be performed from the injection device. The mold clamping mechanism and the mold opening / closing mechanism are not limited to those described above, and a toggle mechanism or the like may be used as an example. Further, the molding machine is not limited to a vertical type, and a horizontal type can perform the same control. The present invention can also be applied to the type shown in Patent Document 2. In that case, the part of the turntable may move in the mold opening / closing direction or may not move.

The present invention is also useful for the following purposes in addition to selecting the optimum rotation speed of the turntable 21 when the mold weight is changed by mold replacement. For example, if a machine breaks down due to another factor while molding continues and an abnormal torque (such as peak torque) is output, the abnormal torque is detected to detect the machine failure early and stop the machine. You can take measures such as checking. Alternatively, tooth skipping generated between the drive shaft 25 and the timing belt 26 can be prevented in advance.

  Further, the molding machine of the present invention may be one that performs injection molding using a metal or an inorganic material other than one that performs injection molding with a resin. In addition to injection molding, a semi-solid material may be molded by stamping molding, transfer molding, or the like, or a solid material may be molded by pressing, as long as the mold can be attached to the rotating disk.

DESCRIPTION OF SYMBOLS 11 Vertical rotary injection molding machine 12 Clamping apparatus 13 1st injection apparatus 14 2nd injection apparatus 15 Fixed board 16 Tie bar 17 Upper board 18 Movable board 19 Clamping cylinder 21 Turning board (rotary board)
23 Servo motor (electric motor)
29a, 29b Upper movable mold (mold)
30a, 30b Lower fixed mold 31 Control device 38 Calculation unit (torque monitoring unit)
41 Current detector pt1, pt2, pt3, pt4 Peak torque

Claims (4)

In the control method of the molding machine in which the turntable to which the mold is attached is rotatably provided by the electric motor,
The rotation speed of the turntable is settable,
When the peak torque of the electric motor is detected at the time of acceleration or deceleration of rotation of the rotating disk, and when it is detected that the peak torque exceeds a predetermined value or more than a predetermined value , a plurality of times ,
A method for controlling a molding machine, characterized in that an alarm signal is issued and a warning message is issued so as to change the rotation speed of the rotating disk to a low speed side . In the control method of the molding machine in which the turntable to which the mold is attached is rotatably provided by the electric motor,
The rotation speed of the turntable is settable,
By detecting the peak torque of the motor at the time of acceleration or deceleration of rotation of the rotating disk, and when it is detected that the detected value of the peak torque is more than a predetermined value or exceeds a predetermined value, a plurality of times ,
A method for controlling a molding machine, comprising: controlling a rotation speed or a rotation time of a rotating disk so that a peak torque of an electric motor during acceleration or deceleration of the rotating disk is lower than a predetermined value or lower than a predetermined value. Peak torque during acceleration and deceleration when the rotating disk is rotated forward 180 degrees in the forward direction, and peak during acceleration when the rotating disk is reversed 180 degrees in the reverse direction in the next molding The method for controlling a molding machine according to claim 1 or 2, wherein torque and peak torque during deceleration are detected . In a molding machine in which a turntable with a mold attached is rotatably provided by an electric motor,
The rotation speed of the turntable is settable,
When the peak torque is detected for the torque of the motor at the time of acceleration or deceleration of rotation of the rotating disk, and the peak torque exceeds a predetermined value or exceeds a predetermined value, a plurality of times ,
A molding machine that issues an alarm signal and issues a warning message to change the rotation speed of the rotating disk to a low speed side .

Images