JP3517282B2 - Ejector condition setting monitoring method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ejector condition setting monitoring method for detecting the presence or absence of a setting abnormality relating to ejector operating conditions.

[0002]

2. Description of the Related Art An injection molding machine capable of arbitrarily setting a mold opening speed, a ejecting limit of an ejector and the like is already known. However, if you eject the ejector before the mold opening is insufficient, the tip of the ejector pin may interfere with the fixed-side mold. Generally, the ejecting operation of the ejector is started, and since the mold opening operation and the ejector operation are performed independently, there is a difficulty in shortening the cycle time. In order to deal with such a problem, an injection molding machine in which a mold opening position for starting the operation of the ejector is set, and the mold opening operation and the ejector ejecting operation are superposed from the stage before the completion of the mold opening. Is proposed. Of course, if the ejector ejecting operation is started immediately after the mold opening, the cycle time of the injection molding work will be shortened by that much, but as mentioned above, if the ejector is ejected before the mold opening is insufficient. There is a risk that the tip of the ejector pin will interfere with the fixed mold. The operator avoids such a risk, and at the same time, in order to shorten the cycle time as much as possible and to ensure that the product is released from the mold, the start timing of the ejector operation, the ejecting speed and the protruding amount of the ejector, and the maximum mold The opening distance and the mold opening speed are set, but these setting operations are carried out depending on the intuition of the operator until tired, and sometimes a serious accident such as damage to the mold is caused.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to carry out an actual injection molding work to determine whether the mold opening operation and the ejector operation are matched. It is an object of the present invention to provide an ejector condition setting monitoring method capable of easily making a determination and preventing accidents such as damage to a mold associated with ejector operation.

[0004]

SUMMARY OF THE INVENTION An ejector condition setting monitoring method of the present invention is based on a set mold opening operation condition and an ejector operation condition, and the mold opening between the ejecting start and the ejecting completion of the ejector. The object is achieved by a configuration in which the amount and the ejecting amount of the ejector are compared with each other, and when the amount obtained by subtracting the ejecting amount of the ejector from the mold opening amount falls below a preset clearance, an abnormality detection signal is output as a deficiency in the setting condition.

Further, the mold opening amount at the time when the ejecting operation of the ejector is completed is obtained based on the set condition of the mold opening operation and the condition of the ejector operation, and the ejecting amount of the ejector when the ejecting operation is completed is calculated from the mold opening amount. The same object was achieved by a configuration in which when the amount obtained by subtracting the protrusion amount falls below a preset clearance, an abnormal condition detection signal is output because the setting conditions are inadequate.

[0006]

According to the set conditions of the mold opening operation and the conditions of the ejector operation, the mold opening amount and the ejecting amount of the ejector are compared in correspondence with each timing from the start of the ejection of the ejector to the completion of the ejection. Alternatively, the mold opening amount at the time when the ejecting operation of the ejector is completed is obtained based on the above condition, and the opening amount of the mold is compared with the ejecting amount of the ejector when the ejecting operation is completed. If the amount obtained by subtracting the ejector projection amount from the mold opening amount is less than the preset clearance, the ejector pin tip and the fixed mold may interfere during mold opening. Output the detection signal. Since the process of determining the possibility of interference between the tip of the ejector pin and the fixed-side mold based on the condition of the mold opening operation and the condition of the ejector operation is possible at any time after the setting of the operating condition is completed, By performing this process before the actual injection molding work, it is possible to prevent accidents such as mold damage due to the ejector operation.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an essential part of an electric injection molding machine Sa and a control device Na of the injection molding machine Sa to which an ejector condition setting confirmation method according to the present invention is applied. Reference numeral 1 is an injection molding machine Sa. Is an injection cylinder, and reference numeral 2 is a screw. The screw 2 is driven in the injection axis direction by the injection servomotor Ms, and is also metered and rotated by the screw rotation servomotor Mr via the power transmission mechanism 3 including a timing belt, a toothed pulley, and the like. A pressure detector 4 for detecting a resin reaction force acting in the axial direction of the screw 2 is provided at the base of the screw 2 so that the injection pressure in the injection holding process and the screw back pressure in the measuring and kneading process are detected. It has become. Further, the injection servomotor Ms is provided with a pulse coder Ps for detecting the position and moving speed of the screw 2, and the screw rotation servomotor Mr is provided with a pulse coder P for detecting the rotation speed of the screw 2.
r is deployed.

A front platen 6 is fixed to the base of the injection molding machine Sa, and a movable platen 5 slidably mounted on a tie bar that fastens the front platen 6 and the rear platen is provided on the rear platen side. It is driven by a tightening servomotor Mc along a tie bar (not shown) via a direct pressure type mold clamping mechanism including a ball screw or the like. The mold clamping servomotor Mc is equipped with a pulse coder Pc for position and speed detection. Further, the rear platen is provided with a mold thickness adjusting mechanism, and the mold at an optimum position is selected according to the thickness of the movable mold 7 mounted on the movable platen 5 and the fixed mold 8 mounted on the front platen 6. Opening and closing and mold clamping operations can be performed. The movable platen 5 is provided with an ejector servomotor Me for causing the ejector pin to project into the cavity of the movable mold 7, and the servomotor Me is similar to the servomotors for the respective axes described above. , A pulse coder Pe for position and velocity detection is provided. Strictly speaking, the ejector servomotor M is provided between the ejector servomotor Me and the ejector pin of the movable mold 7.
The power transmission means on the movable platen 5 side, which is a ball screw or the like for converting the rotational movement of e into a linear motion and causing the ejector rod that is standardly equipped on the movable platen 5, to be pushed by the projecting ejector rod. Generally, an ejector plate on the movable mold 7 side for ejecting the ejector pin is interposed, but accurate adjustment work is performed so that the return position of the ejector rod matches the return position of the ejector plate. As long as the ejector rod returns to the zero position, the protrusion amount of the ejector rod is exactly equal to the protrusion amount of the ejector rod where the cavity surface of the movable mold 7 is zero reference. It will be called "the ejector protrusion amount" without distinction. Strictly speaking, the mold opening amount is the distance between the parting surface of the fixed side mold 8 and the parting surface of the movable side mold 7, and the value is the mold of the movable platen 5. It is equal to the retracted amount of the movable platen 5 with the tightening completion position as the zero reference. Therefore, here, they are referred to as “die opening amount” without distinguishing them. As described above, the ejection amount of the ejector can be detected by the pulse coder Pe, and the mold opening amount can be detected by the pulse coder Pc.

The control unit Na of the injection molding machine Sa includes a CNC CPU 17, which is a numerical control microprocessor,
CPU 16 for PMC which is a microprocessor for programmable machine controller, servo CPU 18 which is a microprocessor for servo control, and A / D
It has a monitor CPU 33 for performing sampling processing of injection pressure and screw back pressure via the converter 34,
Information can be transmitted between the microprocessors by selecting mutual input / output via the bus 28.

The PMC CPU 16 is connected to a ROM 20 storing a sequence program for controlling the sequence operation of the injection molding machine and a RAM 23 used for temporary storage of operation data, and the CNC CPU 17 is connected.
A ROM 21 that stores a program for controlling each axis of the injection molding machine and a RAM 27 that is used for temporary storage of operation data are connected to the. The nonvolatile memory 26 connected to the CNC CPU 17 is a molding condition storage memory that stores various molding conditions and set values, parameters, macro variables, and the like. The mold opening operation conditions and the ejector operation conditions are also non-volatile. It is set and stored in the memory 26.

Further, the servo CPU 18 and the monitor C
Each of the PUs 33 has a ROM 22 that stores a control program dedicated to servo control, a RAM 24 that is used for temporary storage of data, and a ROM 3 that stores a control program related to sampling processing for obtaining pressure data and the like.
A RAM 32 used for temporary storage of 1 or data is connected. Further, the servo CPU 18 has the CPU 18
Servo amplifiers 11 to 14 for driving servo motors for each axis for ejector, mold clamping, screw rotation, injection, etc. are connected via a servo interface 15 based on a command from the. Further, each of the outputs from the pulse coders Pe to Ps provided on the servo motors of the respective axes is fed back to the servo CPU 18 via the servo interface 15, and the ejector protrusion amount calculated by the servo CPU 18 based on the feedback pulse of the pulse coder or The amount of mold opening of the fixed mold 7 and its moving speed, the current position of the screw 2, and the values of its moving speed and rotation speed are stored in the current position storage register and the current speed storage register of the RAM 24.

The input / output circuit 29 is an input / output interface for receiving a signal from a limit switch provided on each part of the injection molding machine or a control panel, and for transmitting various commands to peripheral equipment of the injection molding machine. In addition, the communication interface 30 is an input / output interface for performing data transmission with a host computer or the like as necessary.

A manual data input device 19 with a display is connected to a bus 28 via a CRT display circuit 25 so that a monitor display screen and a function menu can be selected and various data can be input. A numeric keypad and various function keys are provided. In this embodiment, as the conditions for the mold opening operation, the mold opening speed VC, the maximum mold opening distance CT, etc.
The ejector projection speed V is the condition for ejector operation.
E1, the ejector retracting speed VE2, the mold opening position CT1 when the ejector starts the ejecting operation, the ejector ejecting stroke ET2, and the like are interactive operations using the manual data input device 19 with a display (interaction).
Thus, the setting can be arbitrarily stored in the non-volatile memory 26 as in the conventional case. Further, in this embodiment, the value of the clearance α can be arbitrarily set in the non-volatile memory 26 as data unique to the embodiment, which is different from the conventional one.

The value of the clearance α basically needs to be within the range of α ≧ 0. However, if α = 0 is actually set, the product remains on the fixed side mold 8 and is released from the mold. Since it may become impossible, it is generally desirable to set in the range of α> 0 (for example, the ejecting operation of the ejector pin is started at the same speed as the mold opening speed at the same time when the mold opening operation is started. If so, the condition of α = 0 is satisfied, and at the same time, the fixed side remains.) Also, since there is a gap in the mold opening direction that is comparable to the product thickness between the tip of the ejector pin and the fixed side mold 8 at the time of starting mold opening, α should be 0 or a value slightly smaller than that. Even if it is set, the tip of the ejector pin does not directly interfere with the fixed side mold, but the product may be crushed by the ejector pin protrusion, so naturally the clearance setting range is α ≥ Must be 0. That is, preventing the interference between the tip of the ejector pin and the fixed-side die 8 is a convenient expression, and actually,
Crushing of the product due to the ejector pin protruding (in some cases, the ejector pin may buckle),
Also, the interference between the tip of the ejector pin and the fixed-side mold 8 is prevented. The operator considers the thickness and shape of the product, the draft of the fixed side mold 8 and the like, and determines the value of α and sets it in the non-volatile memory 26 so that the problem such as remaining on the fixed side does not occur. As long as at least α ≧ 0, damage to the mold and ejector pin at the time of first mold opening is prevented, but at the time of the next mold closing operation, the product remaining on the fixed side may be pinched and damage to the mold may occur. Because there is.

With the above configuration, the CNC CPU 17 distributes pulses to the servo motors for each axis based on the control program in the ROM 21 and the data such as the molding conditions in the non-volatile memory 26, and the servo CPU 18 for each axis. Based on the movement command distributed by the pulse and the position feedback signal and the speed feedback signal detected by the detectors such as the pulse coders Pe to Ps, the position loop control, the speed loop control and the current loop control are performed in the same manner as in the conventional case. Servo control is performed, and so-called digital servo processing is executed.

FIG. 2 is a flow chart showing an outline of the "condition setting monitoring process" executed by the PMC CPU 16.
In this embodiment, a function menu such as "confirm ejector conditions" is provided as a new selection function, and "condition setting monitoring processing" is executed in response to the operator's selection operation using the function keys. ,
It is also possible to automatically start the "condition setting monitoring process" by causing the PMC CPU 16 to detect that the condition of the mold opening operation or the condition of the ejector operation is newly set or changed. Naturally, when the operator sets or changes the conditions of the mold opening operation and the conditions of the ejector operation, interactive screens such as "clamp setting" and "ejector setting" are displayed on the display of the manual data input device 19 with a display. As a matter of fact, the data to be displayed in the "condition setting monitoring process" may be displayed using the margin of the display. In any case, this “condition setting monitoring process” is a process executed based on the conditions of the mold opening operation and the conditions of the ejector operation stored in the non-volatile memory 26 at that time. If so, there is no particular restriction on when to do this.

The PMC CPU 16 which has started the "condition setting monitoring process" firstly sets the conditions VC (mold opening speed), CT (maximum mold opening distance) of the mold opening operation which are currently set.
And ejector operation condition VE1 (ejector ejecting speed),
VE2 (ejector retraction speed), CT1 (die opening position when ejector starts ejecting operation), ET2 (ejector ejecting stroke) and clearance α are read from the non-volatile memory 26 (step A1), and die opening is started. From the start of ejector ejection to T1 (= C
T1 / VC), the time required from the start of mold opening to the completion of ejector ejection T2 (= T1 + ET2 / VE1), the time required from the start of mold opening to the return of the ejector to its original position T3 (T2 + ET2 /
VE2), the time required from the start of mold opening to the completion of mold opening T4
Each of (= CT / VC) is obtained (step A2).

FIG. 4 is a diagram showing the relationship between the die opening amount of the movable side die 7 (movable platen 5) and the ejecting amount of the ejector in the direct pressure type die clamping mechanism, corresponding to the elapsed time after the start of die opening. Yes, the solid line indicates the mold opening amount of the movable mold 7, and the alternate long and short dash line indicates the ejector protrusion amount. Naturally, only the mold opening operation of the movable mold 7 is performed in the time section from the mold opening start time to T1, and the mold opening operation of the movable mold 7 and the ejector ejecting operation are performed in the time section from T1 to T2. Are polymerized. Similarly, in the time section from T2 to T3, the mold opening operation of the movable side mold 7 and the retracting operation of the ejector are overlapped with each other, and in the time section from T3 to T4, the mold of the movable side mold 7 is overlapped. Only the opening operation will be performed.

Therefore, the PMC CPU 16 once initializes the value of the elapsed time setting register t to 0 (step A).
3) Subsequently, until the value of the elapsed time setting register t reaches the time T4 required for completion of mold opening, the value of the register t is sequentially increased by a predetermined step width Δt (step A
8) According to the value of the elapsed time setting register t at that time (steps A4 to A7), the relationship between the mold opening amount of the movable side mold 7 and the ejector protrusion amount at each time point is displayed with a manual data input device with a display. A graph is displayed on the display 19 and the tip of the ejector pin and the fixed-side mold 8 at each time point are displayed based on the value of the clearance α.
The presence or absence of interference with the
(Processes from (A) to SUB (C)). Here, only the judgment result of the presence / absence of interference and the result of the graph display are finally required. However, if the value of the elapsed time setting register t is increased in synchronization with the real time, the mold opening is performed. It is also possible to draw the operating positions of the ejector and the ejector in time series.

First, the value of the elapsed time setting register t is 0≤
If t≤T1, the determination results of steps A4 to A7 of the processing of the main routine shown in FIG. 2 are all true, and the elapsed time t after the mold opening is started in the processing of SUB (A) of FIG. And the mold opening amount Pt of the movable side mold 7 are displayed in a graph. Needless to say, the value of the mold opening amount Pt is VC × t. The PMC CPU 16 executes the process of SUB (A) every time the value of the elapsed time setting register t is updated in the process of step A8 in the main routine, and obtains the mold opening amount Pt according to the above equation (step a1). , Elapsed time t after starting mold opening and mold opening amount Pt
Is plotted on the display of the manual data input device 19 with a display, and the graph display by the solid line showing the mold opening position is executed (step a2). It should be noted that at this stage, the ejecting operation of the ejector is not started, and naturally there should be no interference between the tip of the ejector pin and the fixed-side die 8, so that the graph display of the ejecting amount of the ejector also determines whether or not there is interference. No processing is required.

The value of the elapsed time setting register t is T
1, that is, when the value reaches the value at the time when the ejecting operation of the ejector is started, the determination result from step A4 to step A6 in the main routine is true, and step A7
Since the determination result of is false, the process of SUB (B) in FIG. 3 is started. The value of the mold opening amount Pt is VC as in the above.
Xt. Further, since the elapsed time after the start of the ejecting operation of the ejector is t-T1, the ejecting amount Qt of the ejector in this section is the ejector ejecting speed VE1 × (t-T1
) Is required. In order to secure a predetermined clearance α between the tip of the ejector pin and the fixed-side mold 8, the value Rt obtained by adding the clearance α to the ejecting amount Qt of the ejector at that time is smaller than the mold opening amount Pt. Must also be smaller. That is, if the condition of Pt> Rt is not satisfied, there is a risk of interference. The PMC CPU 16 uses the elapsed time setting register t
Each time the value of is updated in the process of step A8 in the main routine, the process of SUB (B) is carried out, the mold opening amount Pt and the ejector protrusion amount Qt are obtained according to the above-mentioned formulas, and the presence / absence of interference is determined. A value Rt to be used is obtained (step b1), and the relationship between the elapsed time t after starting the mold opening, the mold opening amount Pt, the ejector protrusion amount Qt, and the value Rt used for the determination process is displayed. Plotted on the display of 19, and the straight line (the mold opening amount Pt) and the alternate long and short dash line (the ejector protrusion amount Qt) are plotted.
), A graph display by a broken line (protrusion amount Rt with clearance added) is executed (step b2), and the magnitude relationship between the mold opening amount Pt and the value Rt used for the judgment process is compared (step b3). , Pt ≤ Rt and there is a danger of interference, a warning message such as "interference" is displayed on the display (step b4). Furthermore, in addition to displaying the warning message, the display color of the plot of Rt may be changed from green to red to call attention.

When it is determined that there is interference, it is necessary to reset the operating conditions of the mold opening and the operating conditions of the ejector so that Pt ≤ Rt. Therefore, at the stage when it is determined that there is interference, that is, When the phenomenon of Pt ≤ Rt occurs, "Interference" is displayed and immediately "condition setting monitoring process"
However, if the interference condition is displayed as a graph when resetting the mold opening operation conditions and ejector operation conditions, how much should the ejector protrusion stroke ET2 be reduced? , How much the mold opening position CT1 at which the projecting operation is started should be shifted, or
Since it is convenient to decide how fast the mold opening speed VC should be increased, in this embodiment, even if Pt≤Rt, a warning message is displayed and the subsequent graph display is continued. I am trying to do it.

Then, the value of the elapsed time setting register t is T
2, that is, when the value reaches the value at which the ejector retracting (returning to the original position) operation is started, the determination results of steps A4 to A5 in the main routine are true, and the determination result of step A6 is false. , S in FIG.
The process of UB (C) is started. The value of the mold opening amount Pt is
As above, VC × t. Further, since the elapsed time after the start of the retracting operation of the ejector is t-T2, the ejecting amount Qt of the ejector in this section is ET2-VE2 * (t-T2) with the ejecting stroke ET2 of the ejector as an initial value.
Required by. As already mentioned, VE2 is the degeneration speed of the ejector. The PMC CPU 16 executes the process of SUB (C) every time the value of the elapsed time setting register t is updated in the process of step A8 in the main routine, and the mold opening amount Pt and the ejector protrusion amount Qt are calculated according to the above-described formulas. And the value of the protrusion amount Rt to which the clearance α is added (step c1), the elapsed time t after the mold opening is started
And the mold opening amount Pt, the ejector protrusion amount Qt, and the value Rt in consideration of the clearance α are plotted on the display of the manual data input device 19 with a display, and the graph display by the straight line, the one-dot chain line, and the broken line is executed, respectively. (Step c2). Since the tip of the ejector pin does not interfere with the fixed-side mold 8 when the ejector retracts, at this stage, step b3 in SUB (B) is performed.
Also, the processing of step b4 is unnecessary.

The value of the elapsed time setting register t is T
3, that is, when the value at the time when the ejector's original position returning operation is completed is reached, the determination result of step A4 in the main routine becomes true and the determination result of step A5 becomes false, so SUB (A ) Is started, and only the mold opening amount of the movable side mold 7 is displayed in a graph.

Finally, when the value of the elapsed time setting register t reaches the mold opening required time T4 and all of the graph displays concerning the mold opening of the movable side mold 7 are completed, this "condition setting monitoring process" is ended.

In the graph shown in FIG. 4, the projection amount Rt, which is the clearance α added in the vicinity of the time T2 at which the ejector ejecting operation is completed, exceeds the die opening amount Pt, and the tip of the ejector pin and the fixed side die 8 are shown. This is an example of a case where interference may occur between the two. In such a case, the conditions of mold opening operation and ejector operation must be set again to avoid interference, but the operator can set the condition by checking the interference state by referring to the graph on the display. Can be easily modified. Figure 4
In the above example, the ejecting stroke ET2 of the ejector is slightly reduced, the mold opening position CT1 at which the ejecting operation is started is slightly shifted in the positive direction, or the mold opening speed VC is slightly increased to make the linear inclination of Pt. By increasing the number, the interference state can be easily avoided.

Further, in the injection molding machine to which the direct pressure type mold clamping mechanism in which the mold opening speed is always maintained at the set value VC is applied, the projection amount Rt obtained by adding the clearance α at the time T2 when the ejecting operation of the ejector is completed. As long as does not exceed the mold opening amount Pt, it can be guaranteed that no interference occurs in the entire time period from the mold opening start (t = 0) to the mold opening completion (t = T4). That is, since the ejecting motion of the ejector is started after the mold opening is started, Rt <Ct1 is generally satisfied at the start time T1 of the ejector operation, and generally, the ejecting speed VE1 of the ejector is higher than the mold opening speed VC. Since it is set at high speed, the slope of the straight line of Rt is Pt.
Since it becomes larger than the slope of the straight line, if Rt does not even exceed Pt at the time T2 when the ejector protrusion amount becomes maximum, Rt <Pt in the entire time period from the start of mold opening to the completion of mold opening. It can be said.

Therefore, if it is only necessary to confirm the presence or absence of interference without displaying the graph as shown in FIG. 4, use the process of FIG. 5 instead of the process of FIGS. 2 and 3. Defective setting conditions can be detected. That is, the mold opening speed VC, the ejector protruding speed VE1, which are the conditions required to obtain the mold opening amount Pt at the time T2 when the ejecting operation of the ejector is completed, the mold opening position CT1 when the ejecting operation is started, and the ejector. Only the protrusion stroke ET2 and the set value α of the clearance (step B1), the time required until the ejector ejecting is completed T2 = (CT1 / VC) + (ET2 / V
E1) is obtained, the value of the mold opening amount Pt at the ejecting operation completion time T2 of the ejector is calculated from the relationship between T2 and the mold opening speed VC, and the value obtained by subtracting the ejecting stroke ET2 of the ejector from the mold opening amount Pt is less than α. The presence or absence of interference is determined depending on whether it is large (step B2), and the determination result is displayed (step B3).

In the above two embodiments, the operator sets the clearance value α in advance. However, the C for PMC is set according to the set value VE1 of the ejector protrusion speed.
The PU 16 may automatically calculate the clearance value α. For example, it is possible to determine only the value of the coefficient k in advance and obtain the value of α by the arithmetic expression of α = k × VE1.

The case of the injection molding machine to which the direct pressure type mold clamping mechanism is applied has been described above with reference to two embodiments.
Also for the injection molding machine to which the toggle type mold clamping mechanism is applied, in which the mold opening speed is not always maintained at the set value VC,
By slightly modifying the processes shown in FIGS. 2 and 3, the presence or absence of interference of the ejector pins can be easily determined. In the toggle type mold clamping mechanism, since the mold opening speed is given by the moving speed VC of the crosshead, the actual mold opening speed, that is, the moving speed of the movable mold 7 is not constant, but this has an effect. This is limited to the case where the required times T1 and T4 are obtained in the process of step A2 in FIG. 2 and the case where the mold opening amount Pt is obtained in the processes of step a1, step b1 and step c1 in FIG. Therefore, as long as the time T1 required to start the ejecting operation of the ejector, the time T4 required to complete the mold opening, and the mold opening amount Pt corresponding to the elapsed time t can be obtained, the results shown in FIGS. Such processing can be directly applied to an injection molding machine having a toggle type mold clamping mechanism.
As already disclosed in Japanese Patent Laid-Open No. 62-160219, an arithmetic expression for obtaining the crosshead position Yc from the position x of the movable platen 7 and the crosshead position Y
The arithmetic expressions for obtaining the position x of the movable platen 7 from c are equation 1 (equation (6) in JP-A-62-160219) and equation 2 (equation (24) in JP-A-62-160219). ).

[0031]

[Equation 1]

[0032]

[Equation 2] Therefore, in the injection molding machine having the toggle type mold clamping mechanism, the time T1 required for starting the ejecting operation of the ejector
In order to obtain, the CT1 is substituted for the position x of the movable platen 7 in the equation 1, and the obtained value is taken as the crosshead position Yc at the start of the ejector ejecting operation. If it is divided by VC, the required time T1 until the ejector ejecting operation is started can be obtained. This is exactly the same in the case of the time T4 required to complete the mold opening. The position x of the movable platen 7 in Equation 1 is set as CT, and the obtained value is set as the crosshead position Yc at the completion of the mold opening. If Yc is divided by the set value VC of the moving speed of the crosshead, the time T4 required to complete the mold opening can be obtained. The above is the process for obtaining the time T1 required to start the ejecting operation of the ejector and the time T4 required to complete the mold opening in the injection molding machine having the toggle type mold clamping mechanism. Needless to say, the values of CT1, VC, and CT are the set values read in the process of step A1, and the required time T1 is set as described above.
As long as it is obtained, the required times T2 and T3 can be obtained in the same manner as in the case of the injection molding machine having the direct pressure type mold clamping mechanism by the same processing as the above-mentioned step A2. The processing of SUB (A) to SUB (C) relating to display and determination of the presence / absence of interference can be carried out according to the case classification for each time section.

Further, in each process corresponding to SUB (A) to SUB (C), the mold opening amount Pt of the injection molding machine having the toggle type mold clamping mechanism is obtained corresponding to the elapsed time t after the mold opening is started. At this time, the value of VC × t may be substituted for the crosshead position Yc of the equation 2, and the value x obtained by the equation of the equation 2 is exactly the value of the mold opening amount Pt. Therefore, SUB (A)
It is also easy to obtain the mold opening amount Pt in the toggle type mold clamping mechanism in place of the processes of step a1, step b1 and step c1 in each process of SUB (C), and the injection has the toggle type mold clamping mechanism. Even in the case of molding machines,
The graph display and the presence / absence of interference can be performed in substantially the same manner as the processing shown in FIG.

In the above embodiments, the time required for acceleration / deceleration until the mold opening speed, the ejecting speed and the retracting speed of the ejector reach the desired speed is zero, but the time constant of the acceleration / deceleration required time is taken into consideration. Then, the same processing as in the above-described embodiment can be performed. The time constant mentioned here is a time (set value) required for the mold opening speed, the ejecting speed and the contracting speed of the ejector to reach a desired speed, and has a different meaning from the generally known time constant.

Therefore, assuming that the acceleration / deceleration time constant of the mold opening is τc and the acceleration / deceleration time constant of the ejector is τe, linear acceleration / deceleration is performed in both cases, the relationship between the time and the mold opening speed and the relationship between the time and the ejector speed. Are as shown in FIGS. 6 and 7, respectively. Therefore, the mold opening amount Pt is 0 ≦.
In the interval of t ≦ τc, Pt = {VC / (2 × τc)} × t ² τc <t ≦ CT / VC, in the interval of Pt = VC × τc / 2 + VC × (t−τc) CT / VC <t In the section of ≦ τc + CT / VC, Pt = CT− (VC × τc) / 2 + VC × (t−CT / VC) −
It becomes {VC / (2 × τc)} × (t-CT / VC) ² .

Further, the time T1 required until the protrusion starts depends on the value of the mold opening position CT1 when the protrusion starts, CT1
≤τc × VC / 2, T1 = (2 × τc × CT1 / VC) ^1/2 CT1> τc × VC / 2, T1 = τc + {(CT1-τc × VC / 2) / VC } Becomes.

Further, the protrusion amount Qt until the protrusion is completed
Depending on the value of the time t, with 0 ≦ t ≦ T1 interval, Qt = 0 at T1 ≦ t ≦ T1 + τe section, Qt = {VE1 / (2 × τe)} × (t-T1) 2 T1 + τe <T≤T1 + ET2 / VE1 interval, Qt = VE1 * [tau] e / 2 + VE1 * (t-T1- [tau] e) T1 + ET2 / VE1 <t≤T1 + [tau] e + ET2 / VE1 interval, Qt = ET2- (VE1 * [tau] e) / 2 + VE1 x (t-T1-
ET2 / VE1)-{VE1 / (2 × τe)} × (t−T1−
It becomes ET2 / VE1) ² .

As a result, the value at time t is set to the predetermined step width Δ.
While sequentially increasing by t, the mold opening amount Pt and the protruding amount Qt are obtained according to the value at the time t, and the interference is determined by whether the value obtained by adding α to the protruding amount Qt is larger than the mold opening amount Pt. To do. Even after the completion of the protrusion, the protrusion amount Qt can be obtained and determined in the same manner as above. It is also possible to display a graph.

Even with exponential acceleration / deceleration other than linear acceleration / deceleration, the mold opening amount Pt and the protrusion amount Qt at each time can be obtained from the acceleration / deceleration formula and the determination can be performed in the same manner as described above. For example, the speed V when accelerating from speed 0 to speed V by exponential acceleration / deceleration
(T) is V (t) = V × {1-exp (-t / τ)}
Therefore, the speed when decelerating from speed V to speed 0 by exponential acceleration / deceleration is V (t) = V × exp (−t / τ).
However, τ represents a time constant, exp represents an exponential function, and the time at the acceleration start point / deceleration start point is t = 0.

Also, when the mold opening speed and the ejecting speed are set to be switched during the mold opening and during the ejecting (in the case of multi-stage mold opening speed / multi-stage ejecting speed), the mold opening amount and the protruding amount at the time t. The speed may be switched and the mold opening amount and the protrusion amount may be obtained to perform the determination and the graph display while determining whether or not has reached the position for switching the speed.

Further, even when the mold opening is temporarily stopped during the mold opening, the determination and the graph are performed by considering the set value of the position where the mold opening is temporarily stopped and the set value of the time when the mold opening is temporarily stopped. Can be displayed.

[0042]

According to the ejector condition setting monitoring method of the present invention, based on the set mold opening operation condition and the set ejector operation condition, the amount of opening of the mold and the ejector from the start to the end of the protrusion of the ejector. Compared with the protrusion amount, if the amount obtained by subtracting the ejector protrusion amount from the mold opening amount falls below the preset clearance, the abnormal condition detection signal is output as a deficiency in the setting conditions, so the actual injection molding work is performed. It is possible to determine whether or not the matching between the mold opening operation and the ejector operation is good, and it is possible to prevent accidents such as damage to the mold associated with the ejector operation.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of an electric injection molding machine of an embodiment to which an ejector condition setting confirmation method according to the present invention is applied.

FIG. 2 is a flowchart showing an outline of condition setting monitoring processing in the same embodiment.

FIG. 3 is a flowchart showing a part of condition setting monitoring processing.

FIG. 4 is a diagram showing an example of a graph display drawn by a condition setting monitoring process.

FIG. 5 is a flowchart showing an outline of a condition setting monitoring process of another embodiment.

FIG. 6 is a diagram illustrating an example of acceleration / deceleration control.

FIG. 7 is a diagram illustrating an example of acceleration / deceleration control.

[Explanation of symbols]

7 Movable mold 8 Fixed mold 16 PMC CPU 19 Manual data input device with display 26 Non-volatile memory Servo motor for Me ejector

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-97813 (JP, A) JP-A-62-161516 (JP, A) JP-A-7-304072 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (2)

(57) [Claims] 1. An injection molding machine in which the conditions of the mold opening operation and the conditions of the ejector operation can be changed, based on the set conditions of the mold opening operation and the conditions of the ejector operation, from the start of ejection of the ejector. Comparing the mold opening amount until the protrusion completes with the ejector protrusion amount, and if the amount obtained by subtracting the ejector protrusion amount from the mold opening amount falls below the preset clearance, an abnormal condition detection signal is output as a setting condition deficiency. The ejector condition setting monitoring method characterized in that 2. In an injection molding machine in which the conditions of the mold opening operation and the conditions of the ejector operation can be changed, the ejecting operation of the ejector is based on the set conditions of the mold opening operation and the ejector operation. The mold opening amount at the time of completion is calculated, and when the amount obtained by subtracting the protrusion amount of the ejector at the time of completion of the protrusion operation from the mold opening amount falls below a preset clearance, an abnormality detection signal is output as a setting condition deficiency. The ejector condition setting monitoring method characterized by the above.