JP2562897B2 - Injection molding machine monitoring method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a method for monitoring an injection molding machine, and more particularly, to a method capable of reliably detecting a deterioration in monitoring function.

[Outline of Invention]

The present invention provides a monitoring device for an injection molding machine that monitors whether or not an abnormality has occurred in an injection molding operation based on the brightness data after the mold opening and before the projection and the brightness data after the projection and the value of the brightness data is effective. By making it possible to surely detect when a value that cannot perform such a determination operation is reached, it is possible to realize a monitoring device that can prevent a secondary abnormal operation from occurring.

[Conventional technology]

Conventionally, for example, as a monitoring device for monitoring the injection molding operation of an injection molding machine for injection molding a synthetic resin material, JP-A-60-39
As disclosed in Japanese Patent No. 581, a plurality of monitoring areas are provided on an image obtained based on a video signal obtained by imaging a main body of an injection molding machine with a television camera, and a luminance change in the monitoring area. There has been proposed a method in which whether or not the injection molding machine main body is normal is determined by using.

As shown in FIG. 6, the monitoring device for an injection molding machine of this type, in a state where the movable side mold 2 of the injection molding machine main body 1 is in pressure contact with the fixed side mold 3 (this state is called a mold clamping state), By injecting the synthetic resin material through the conduit 4, an injection molded product is molded in the movable side mold 2 and the fixed side mold 3. This injection-molded product is attached to the inner surface of the movable side mold 2 when the movable side mold 2 is retracted from the fixed side mold 3 to a position separated along the guide 5 (this state is called a mold open state). It is brought to the mold open position. After that, the injection-molded product attached to the movable side mold 2 is pushed down from the movable side mold 2 by a protruding pin (not shown) protruding from the rear side of the movable side mold 2 (this operation is called a protruding operation).

Thus, when one injection-molded product is taken out by dropping from the movable side mold 2, the one-cycle operation of the injection-molding process ends and the next injection-molding process starts. At this time, first, the movable side mold 2 advances toward the fixed side mold 3, and the movable side mold 2 returns to the clamped state where the movable side mold 2 is pressed against the fixed side mold 3, and in this state, the synthetic resin material is injected through the conduit 4. A new injection molded product is molded. Every time the injection-molded product is molded in the same manner, the movable side mold 2 is retracted to the mold open state with the injection-molded product adhered thereto, and thereafter the operation of dropping the injection-molded product is executed.

The injection molding machine main body 1 having such a configuration is driven by the drive control signal S1 formed based on the sequencer provided in the injection molding machine main body drive control device 6. The so-called "remaining mold remaining" in which the injection molded product remains attached to the fixed mold 3 when the mold is opened.
Or the so-called "sheath mold" in which the injection molded product is not completely molded and a part is missing, or the movable side mold 2 is displaced from the regular mounting position, so-called "slide core". There is a possibility that an abnormality may occur, such as being in the “positional deviation” state.

In addition, after the ejecting operation, the injection molding product remains in the movable mold 2 without being ejected, resulting in a so-called “falling defect” state, or when the injection molding product is ejected, a protruding pin is broken or a so-called “pin break” state occurs. There is a risk of abnormalities such as swelling.

When these abnormalities occur, if you leave this state,
In the next injection molding cycle, if the movable side mold 2 and the fixed side mold 3 are damaged or a defective product is molded, a secondary accident such as an accident may occur. 7 is provided.

The monitoring device 7 has a television camera 8, takes an image of, for example, the periphery of the movable mold 2 of the injection molding machine body 1, and inputs the video signal VD thus obtained to the monitoring control device 9.

The supervisory controller 9 sends a sequence control signal IN indicating the injection molding work step from the injection molding machine main body drive controller 6.
In response to this, a judgment operation is performed in synchronism with the operation of the injection molding machine main body 1 to determine whether or not an abnormality has occurred, and a monitoring control signal OUT is sent to the injection molding machine main body drive control device 6 based on the judgment result.
Is sent to control the operation of the injection molding machine body 1.

[Problems to be solved by the invention]

By the way, when determining whether or not there is an abnormality in the injection molding machine body 1, the monitoring control device 9 of the monitoring device 7 sets the brightness of the monitoring regions in advance for a plurality of monitoring regions measured on the screen represented by the video signal VD. The movement of the movable mold 2 of the injection molding machine body 1 and the state of the injection-molded product that has been molded are sensed depending on whether or not the set reference brightness is exceeded.

By the way, in general, it is unavoidable that the magnitude of the luminance of each monitoring region is subject to a change with time due to various conditions.

In particular, when the characteristics of the components forming the television camera 8 and the monitoring control device 9 that form the monitoring device 7 are deteriorated, the characteristics that change due to a change in ambient temperature change, or the injection molding machine body 1 When the amount of light of the illumination light source provided for it is too large or too small and the amount of light incident on the television camera 8 exceeds the proper range and becomes too large or too small, or the television camera 8 is preset. If you move from the position for some reason,
It is unavoidable that the brightness of each part of the image obtained by the video signal VD changes.

Particularly problematic is that due to such changes over time,
If the brightness level that should be determined to be normal and the brightness level that is to be determined to be abnormal approach each other due to the narrowing of the variation range of the brightness that occurs in the video signal VD when the injection molding machine body 1 operates, a correct determination is made. There is a risk that it will be impossible.

When such a change with time occurs, from the viewpoint of the function of the monitoring device 7, when it is abnormal, it should not be judged as normal.

Actually, in the case of the monitoring device 7 of the injection molding machine, the brightness level when the injection molded product is attached to the movable side mold 2 after the mold is opened and before the projection, and the injection molded product is pushed down by the projecting operation. If the brightness level in the closed state approaches, it may not be possible to make a correct determination.

Further, as in the case of FIG. 6, a monitoring area is set on the screen obtained by the video signal VD, and whether the injection molding machine body 1 is normal or abnormal is determined based on the change in the brightness of the monitoring area. In such a case, if the position of the television camera 8 with respect to the injection molding machine body 1 shifts, the timing of capturing luminance data from the video signal VD shifts, or the stop position of the movable side mold 2 fluctuates, the luminance difference is almost eliminated. There is a possibility that the brightness data may be taken in from a region where there is no such a case, and in such a case, an erroneous determination may result.

The present invention has been made in consideration of the above points, and when obtaining luminance data from a video signal obtained by a television camera, a detected luminance level that should be determined as normal and a detected luminance level that should be determined as abnormal. It is intended to propose a monitoring method for an injection molding machine that can prevent the possibility of erroneous determination by detecting in advance before the determination cannot be made when the difference from the level approaches. is there.

[Means for solving problems]

In order to solve such a problem, in the present invention, the first detection data DA representing the brightness of the monitoring target after the mold opening and before the protrusion.
Injection molding that monitors whether or not an abnormality has occurred in the injection molding operation of the injection molding machine main body based on the presence or absence of a change between TA and the second detection data DATA that indicates the brightness of the monitoring target after the mold has opened and has protruded. In the machine monitoring method, the change width evaluation data in which the difference between the values of the first determination data BOP1 to BOP16 and the values of the second determination data BDR1 to BDR16 obtained based on the first detection data DATA has a predetermined value. Whether or not it becomes impossible to correctly determine the occurrence of an abnormality because the value is smaller than ΔD1 to ΔD16
1st step for judging whether or not the first detection data DATA
Alternatively, the upper limit evaluation data in which the values of the third determination data BOP1 _{max to} BOP16 _max obtained based on the second detection data DATA are lower than the value of the full scale FS that can be taken in by a predetermined upper limit margin value ΔF (FS-ΔF) 1- (FS-Δ
F) A second step of making a second determination as to whether or not the monitoring target becomes too bright for correctly determining the occurrence of an abnormality due to a value higher than 16, and the first detection data.
Lower limit evaluation data ΔU1 having values of the fourth determination data BOP1 _{max to} BOP16 _max obtained based on DATA or the second detection data DATA is higher than the value when the brightness is 0 by a predetermined lower limit margin value. And a third step for making a third judgment as to whether or not the monitoring target becomes too dark to correctly judge the occurrence of an abnormality due to a value lower than ΔU16,
When a negative determination result is obtained in any one of the first, second, and third steps, it is determined that the monitoring operation for the abnormality occurrence in the injection molding operation is impossible.

[Action]

First and second detection data DA representing the brightness of the monitoring target
First and second determination data BOP1 to be formed based on TA
The difference between BOP16 and BDR1 to BDR16 is determined by the predetermined change width evaluation data Δ
Compared with the values of D1 to ΔD16, the third judgment data BOP1 _max
~ BOP16 _max is the upper limit rating data (FS-ΔF) 1- (FS-Δ
F) Compared with the value of 16, the fourth judgment data BOP1 _max
~ BOP16 _max is compared with the values of the lower limit rating data ΔU1 to ΔU16 to perform the determination operation, respectively, so that even if the first and second detection data determined to be normal are obtained, the entire monitoring device As a result, it is possible to promptly determine when the tendency is such that the determination cannot be performed, and thus it is possible to prevent occurrence of a secondary abnormality on the injection molding machine body 1 side.

〔Example〕

 An embodiment of the present invention will be described in detail with reference to the drawings.

[1] Configuration of the embodiment In FIG. 2 in which parts corresponding to those in FIG. 6 are assigned the same reference numerals, the supervisory control device 9 sends the video signal VD generated in the television camera 8 to the video data input unit 11 ,
In addition to being received by the timing control unit 12, the monitor unit 13 receives it by the monitor 15 via the superimposing circuit 14. The timing control unit 12 receives a sync signal SY (which is a horizontal sync signal and a vertical sync signal) included in the video signal VD in a sync signal generation circuit 21, and a clock signal synchronized with the horizontal sync signal and the vertical sync signal. CL is the timing generator
Give to 22.

The timing generation circuit 22 counts the clock signal CL and forms position data representing the current scan position for each line of the video signal VD. Then, the injection molding machine main body drive control device 6 outputs a mold opening signal IN1 (indicating that the movable side mold 2 of the injection molding machine main body 1 has performed a mold opening operation) or a protrusion completion signal IN2 (a protrusion pin has completed the protrusion operation. It means that)
Is given, the timing generation circuit 22 outputs the scan position data of the video signal VD to the central processing unit (CPU) 2
When the position data included in the timing control data TIMD given via the bus 23 under the control of 4 coincides, the sampling pulse SMP having the pulse width corresponding to the width data of the timing control data TIMD is generated to generate the video. The marker display signal MKS can be supplied to the hold circuit 25 of the data input section 11 and the marker generation circuit 26 of the monitor section 13.

In the case of this embodiment, the timing generation circuit 22 displays an image based on the video signal VD on the display screen 15A (third part) of the monitor 15.
When the timing control data TIMD is given from the bus 23 in the state shown above, the display screen 15
A marker MK representing a plurality (for example, 16 monitoring areas A1, A2, ... A16) on A is superimposed and displayed together with the cursor K0.

Further, the timing generation circuit 22 causes the hold circuit 25 to sample the sampling pulse SM when the monitoring device 7 is in the inspection mode.
By giving P, analog video information about the video signal VD for one frame is taken into the hold circuit 25, and when the scan for the frame is finished, the output pulse OUT is given to the hold circuit 25. The analog video information held in the hold circuit 25 is taken into the bus 23 as video data DATA via the analog / digital conversion circuit 27.

Here, the timing control data TI given from the bus 23
The MD assigns x-coordinates and y-coordinates to the horizontal and vertical directions of the display screen 15A for the video information of the video signal VD, and accordingly the image to be displayed on the display screen 15A (Fig. 3) of the monitor 15, to monitor the area One point of A1, A2 ... A16 (for example, the point (x ₁ , y ₁ ) in the upper left corner, (x ₂ , y ₂ ) …… (x ₁₆ , y ₁₆ ))
Position data and the x of monitoring areas A1, A2 ... A16
The width W _{x in the} axial direction and the width data designating the width W _y in the y-axis direction are included in the timing generation circuit 22.
When the count content of matches the specified position data,
A sampling pulse SMP having a pulse width corresponding to the width data W _x and W _y and a marker display signal MKS are generated.

In the case of this embodiment, the television camera 8 sends out the non-interlace type video signal VD, and the hold circuit 25
Of the video signal VD captures the luminance signal at a timing corresponding to the monitoring areas A1, A2, ... A16, accumulates this in an analog manner, and converts it into 8-bit luminance data in the analog / digital conversion circuit 27. This is sent as video data DATA.

The CPU 24 has a video data input unit 11 and a timing control unit 1.
2. While responding to the operation input of the operation switch unit 30, the monitor unit 13 according to the program data stored in the program memory of the ROM 31 and using the register (FIG. 4) of the RAM 32 as necessary. ,Control.

In the case of this embodiment, the RAM 32 (Fig. 4) includes a cursor position register 32A, a monitoring area preset register 32B, a video data register 32C, a normal / abnormal data register 32D, a judgment possibility evaluation data register 32E, and a brightness average value data register 32F. , Maximum luminance average value data register 32G.

The cursor position register 32A is displayed on the monitor 15 display screen 15A.
(FIG. 3) The data (consisting of position data in the x and y directions) representing the position of the cursor K0 displayed above is stored.

The monitoring area preset register 32B is used for monitoring areas A1 and A2.
…… A16 position (x ₁ , y ₁ ), (x ₂ , y ₂ ) …… (x ₁₆ ,
position data representing y ₁₆ ) and width data W _{x in the} x and y directions
And W _y are stored.

The video data register 32C, when the luminance information about the 16 monitoring areas A1 to A16 integrated and held in the hold circuit 25 is converted into the video data DATA in the analog / digital conversion circuit 27 and taken into the bus 23, Store this.

The normal / abnormal rating data register 32D stores rating reference data for determining whether or not the luminance data taken into the video data register 32C is normal. When monitoring area A1 ~ A1
For 6 brightness data, the rating reference data OP which is the average value of the brightness data in the past multiple injection molding cycles
1 to OP16 are stored as a first evaluation reference data group, and the evaluation reference data DR1 to DR16 which is the average value of past N injection molding cycles for the brightness data of the monitoring areas A1 to A16 in the state after the protrusion. Is stored as a second evaluation standard data group.

In practice, the rating reference data OP1 to OP16 and DR1 to DR16 are pre-stored by the CPU 24 by the operator using the operation switch unit 30 (FIG. 2).

Here, the first rating reference data OP1 to OP16 indicate whether or not an abnormality such as “short mold”, “remaining of cavities”, or “positional deviation of slide core” has occurred in the state after the mold is opened and before the protrusion. The second rating reference data DR1 to DR16 are used in the first monitoring step for determining, and the second evaluation reference data DR1 to DR16 are used to determine whether or not an abnormality such as "falling defect" or "pin break" has occurred in the state after projection. 2 monitoring step.

The judgment possibility evaluation register 32E stores the evaluation reference data for judging whether or not the monitoring areas A1 to A16 are in the judgment impossible state, and the variation range evaluation data ΔD1 to ΔD16 for the monitoring areas A1 to A16. And upper limit luminance rating data (FS-ΔF) 1 to (FS-ΔF) 16 and lower limit luminance rating data ΔU1 to ΔU16.

These judgment applicability evaluation data, that is, change range evaluation data ΔD1 to ΔD16, upper limit brightness evaluation data (FS-ΔF) 1
~ (FS-ΔF) 16, lower limit luminance rating data ΔU1 to ΔU16
Is the video data input unit 11 based on the current video signal VD.
It is the brightness information for judging whether the video data taken in from the video data register 32C is at a brightness level that can be judged properly, and when one of the three judgment conditions described below is not satisfied, Is determined by the CPU 24 to be in a state where a normal determination operation cannot be performed (that is, a determination impossible state).

In the first determination condition, the i-th (i = 1, 2 ...
16) Monitoring area Ai, luminance average data after mold opening and before projecting captured for past multiple injection molding cycles
The absolute value of the difference between BOPi (that is, BOP1 to BOP16) and the projected brightness average value data BDRi (that is, BDR1 to BDR16) is the following equation: | BOPi−BDRi | <ΔDi (i = 1, 2 ... 16) ... ... As represented by (1), change range rating data ΔDi (i = 1, 2
...... 16) When it is smaller, it is judged that the rating operation in the monitor control device 9 cannot be executed without malfunction (that is, in the undecidable state).

In the formula (1), the variation range evaluation data ΔDi is a variation due to a change in external light (for example, flicker of brightness due to a fluorescent lamp), periodic external noise, accuracy of the analog / digital conversion circuit 27, or an object to be inspected. In consideration of the variation in the brightness and position of the injection-molded product, the variation range evaluation data ΔDi or less is determined in consideration of the limit that cannot be determined.

Incidentally, since the first and second monitoring steps are based on the principle that the determination is made based on the change in the brightness of the part corresponding to the monitoring areas A1 to A16 in the video signal VD after the mold opening, If the range of change in is extremely small, it becomes undecidable due to the influence of noise components.

In practice, the change range rating data ΔD1 to ΔD16 are stored in advance by the CPU 24 by the operator using the operation switch unit 30 (FIG. 2).

The brightness average value data BOP1 to BOP16 and BDR1 to BDR16 are updated by the CPU 24 each time the injection molding cycle is repeated.

In the second judgment condition, the upper limit brightness rating data (FS-
ΔF) i (i = 1, 2 ... 16) can process the video data input based on the video signal VD of the television camera 8 when the illumination intensity for the injection molding machine body 1 is too strong. There is a possibility that the range will be exceeded, and in this case the data will overflow and correct evaluation cannot be performed. Therefore, as in the following equation BOPi _max > (FS−ΔF) i (i = 1, 2 …… 16) …… (2) , Upper limit luminance representing a value FS−ΔF obtained by subtracting the upper limit margin value ΔF from the full scale value FS that can be captured by the maximum luminance average value data BOPi _max for all the monitoring areas Ai (i = 1, 2 ... 16) Rating data (FS-ΔF) i
When it becomes larger, it is judged that the judgment cannot be made effectively.

Here, the maximum luminance mean value data BOPI _max, when limited reference data OPi per injection molding cycle to be repeated is updated, this maximum luminance CPU24 as the maximum luminance mean value data BOPI _max time has decreased to the maximum value Store in average value data register 32G.

Further, FS is a full-scale value of the video data DATA that can be taken into the monitor control device 9, and in this embodiment, the analog / digital conversion circuit of the video data input section.
FS = 255 is selected by using 8 bits as 27. Further, ΔF indicates a margin value from the full-scale value FS, and in this embodiment, ΔF = 4 is selected.

Actually, the full-scale data FS and the margin value data ΔF are obtained by the operator operating the operation switch unit 30.
Is entered.

Thus, in the i-th monitoring area Ai, brightness average value data BOPi obtained for past N injection molding cycles
Is reached to the maximum value, the data of the maximum value is obtained as BOPi _max so that the determination of the equation (2) can be executed.

Thirdly, the lower limit luminance rating data ΔU1 to ΔU16 have a luminance data value of 0 which can be fetched from the video signal VD of the television camera 8 into the video data input section 11 when the illumination intensity of the injection molding machine body 1 is too weak. Since it becomes impossible to make a decision because of approaching to, the maximum value BOPi _max of the brightness average value data BOPi is the brightness as shown in the following equation, BOPi _max <ΔUi (i = 1, 2 …… 16) (3). Lower limit luminance rating data ΔUi that represents the lower limit margin value from 0
When it becomes smaller, it is determined that it cannot be determined.

In the case of this embodiment, the value of the lower limit luminance evaluation data ΔUi is selected to ΔUi = 10 based on the analog / digital conversion circuit 27 of the video data input unit 11 having an 8-bit configuration, and the operator operates the switch unit in advance. Input by operating 30.

Thus, in the i-th monitoring area, when the maximum value BOPip _max of the average values BOPi of the brightness data fetched during the past N times of injection molding cycles becomes less than ΔUi = 10, the CPU 24 cannot determine. judge.

In the above-described embodiment, the relationship of the brightness data levels determined by the expressions (1) to (3) can be expressed as shown in FIG.

That is, first, the luminance data that can be fetched from the video data input unit 11 is FS = 255 (decimal number) for full scan S as 8-bit data, while the margin value ΔF is ΔF = 4. Therefore, as shown in the equation (2), the range FR1 is the undecidable range in which the maximum brightness average value data BOPi _max is larger than the value (FS-ΔF) i = 251 of the upper limit brightness rating data (FS-ΔF) i. .

Next, since the value of the lower limit luminance rating data ΔUi is ΔUi = 10, the range ER2 in which the maximum luminance average value data BOPi _max is smaller than the lower limit luminance rating data ΔUi cannot be determined as expressed by the equation (3). It becomes the range.

Then, even in the range ER3 from the lower limit luminance rating data ΔUi to the upper limit luminance rating data (FS−ΔF) i, (1)
As expressed by the formula, the brightness average value data after the mold opening and before the protrusion
Absolute value of the difference between BOPi and brightness average value data BDRi after protrusion | B
When OPi−BDRi | is smaller than the change width rating data ΔDi, the determination cannot be made.

[2] Injection Molding Cycle In the above-described configuration, the monitoring control device 9 and the injection molding machine main body drive control device 6 together with the injection molding machine main body drive controller 6 according to the processing procedure of FIG. Determine whether it is occurring.

The injection molding machine main body drive controller 6 is a step SP shown in FIG.
In step 1 of the injection molding cycle, after the injection molding machine body 1 is clamped in step SP2,
The injection molding material is injected in step SP3, and the mold opening operation is performed in step SP4.

At this time, the injection molding machine main body drive control device 6 inputs the mold opening signal IN1 to the timing generation circuit 22 of the monitoring control device 9, and the timing generation circuit 22 sends this to the CPU 24 via the bus 23 as timing control data TIMD. Forward.

Here, the CPU 24 moves to step SP5, and the above equation (1)
The undecidable condition in the equation (3) is judged. Ie CP
U24 reads out the brightness average value data BOP1 to BOP16 after mold opening and before projection and the brightness average value data BDR1 to BDR16 after projection from the brightness average value data register 32F (Fig. 4), and determines whether or not the judgment is possible. Change range Rating data ΔD
1 to ΔD16 are read out, and the determination operation of the equation (1) is executed for all the monitoring areas A1 to A16.

If an affirmative result is obtained as a result, the monitoring control device 9 when a change in luminance occurs in the movable mold 2 of the injection molding machine body 1 (that is, when the injection molded product is changed from a certain state to a pushed-down state). Means that it has been confirmed that can make an effective determination operation.

Next, the CPU 24 reads the maximum brightness average value data BOP1 _{max to} BOP16 _max from the maximum brightness average value data register 32G, and the upper limit brightness rating data (FS-ΔF) 1 to (FS-ΔF) 16 from the judgment acceptability rating data register 32E. Is read and the determination operation of the equation (2) is executed.

If a positive result is obtained as a result, it means that the illumination intensity for the injection molding machine body 1 is not too bright,
Thus, the video data input section 11 does not overflow (that is, the analog / analog having only 8-bit conversion capability).
It can be confirmed that effective luminance data (not to overflow the digital converter 27) can be captured.

Subsequently, the CPU 24 is the maximum brightness average value data register 32G.
The maximum brightness average value data BOP1 _{max to} BOP16 _max are read from the same, and the lower limit brightness rating data ΔU1 to ΔU16 are read from the judgment possibility evaluation data register 32E to execute the judgment of the formula (3).

If a positive result is obtained as a result, it means that the illumination intensity of the injection molding machine main body 1 is not too dark, and thus the video data input unit 11 has a signal level of a luminance large enough to make an effective determination operation. You can verify that you can capture the data.

Thus, when a positive result is obtained for all the determination operations of the expressions (1) to (3), the CPU 24 moves to step SP6 and executes the first monitoring processing.

The first monitoring process is a step of processing data for determining whether or not there is an abnormality such as "short mold", "remaining gear bit", or "misalignment of slide core". Luminance data about A1 to A16 is captured as the first detection data in the video data input unit 11 and then transferred to the video data register 32C, and the data is sequentially read out for each monitoring area A1, A2, ... The rating reference data OP1, OP2, ... OP16 are sequentially read and compared and judged. When the comparison judgments for all the monitoring points are finished, the CPU 24 moves to step SP7 and judges whether the state of the injection molding machine body 1 before the protrusion after the mold opening is normal.

When a positive result is obtained in step SP7, the CPU 24 sends the protrusion command signal OUT1 via the control signal generation circuit 35, and thus the injection molding machine main body drive control device 6 is stepped.
In SP8, the injection molding machine 1 is caused to project.

When the ejection is completed, the injection-molding machine main body drive control device 6 sends the ejection completion signal IN2 to the timing generation circuit 22 of the monitoring control device 9, and the timing generation circuit 22 transfers this to the CPU 24 as timing control data TIMD. .

Therefore, the CPU 24 moves to step SP9 and executes the second monitoring process. The second monitoring process is a step for monitoring abnormalities such as “falling defect” and “pin break”, and the CPU 24 uses the video data as the second detection data in the video data input unit 11 based on the projected video signal VD. After capturing, transfer to video data register 32C. The CPU 24 reads out this data sequentially, and the normal / abnormal judgment data register 32D
The rating reference data DR1 to DR16 are read from and the comparison judgment is made.

When the comparison / determination processing is completed for all the monitoring areas A1 to A16, the CPU 24 moves to step SP10 and determines whether or not the state of the injection molding machine body 1 after the projection is normal.

If an affirmative result is obtained as a result, the CPU 24 determines the first and second luminance data stored in the video data register 32C in the next step SP11 as the first and second detection data before and after projection. And the brightness average value data BOP1 to BOP16 and BDR1 to BDR16 as the first and second determination data based on the second detection data in all monitoring areas.
A1 to A16 are recalculated and updated to the data of the brightness average value data register 32F, and the brightness average value data BOP1 to BO before the protrusion after the mold opening is included in the updated data.
If P16 is the maximum value, it is stored in the maximum brightness average value data register 32G as maximum brightness average value data BOP1 _{max to} BOP16 _max (this is used as the third and fourth determination data).

Thus, one injection molding cycle is completed when the injection molding machine main body 1 is operating normally, and the CPU 24 sends the mold clamping command signal OUT2 via the control signal generation circuit 35 to drive the injection molding machine main body. The controller 6 moves to the above-mentioned step SP2 and executes the mold clamping process in the next injection molding cycle.

By the way, when a negative result is obtained in the above step SP5, this means that the change width of the luminance data captured in the video data input unit 11 becomes narrow, or the illumination intensity becomes excessive or excessive, which causes the monitoring control device. 9 means that there is a possibility that the judgment cannot be made.

Therefore, the CPU 24 moves to step SP12 and sends the stop command signal OUT3 to the injection molding machine drive control device 6 via the control signal generation circuit 35, and also drives the alarm device 40 (Fig. 2) to turn on the buzzer 40A. The alarm display lamp 40B is lit and displayed at the same time as the sounding operation is performed to notify the operator that an abnormality has occurred.

In the case of this embodiment, the CPU 24 additionally sends a marker display signal to the marker generation circuit 26 via the timing generation circuit 22.
By sending MKS, the cursor K0 displayed on the display screen 15A (FIG. 3) is caused to blink so that the operator who visually monitors the monitor 15 is notified of the occurrence of the abnormality. There is.

In this way, the injection molding machine main body drive control device 6 forcibly shifts the injection molding machine main body 1 as a whole to the stopped state, thereby performing processing work for eliminating the cause of the operator's indecisability in the next step SP13. Await.

At this time, when the operator determines that the cause of the undecidability is that the variation range of the brightness data is narrow based on the equation (1), the characteristics of the components of the television camera 8 and the monitor control device 9 that configure the monitor 7 are deteriorated. After performing work for recovering abnormal conditions such as changes in characteristics due to changes in ambient temperature and movement of the position of the television camera 8 with respect to the injection molding machine body 1, the injection molding machine body drive control device 6 is operated. The injection molding cycle is restarted.

At this time, the injection-molding machine main body drive control device 6 returns to the above-mentioned step SP2 and starts a new injection molding cycle.

When a negative result is obtained in step SP7 or step SP10 described above, the CPU 24 proceeds to step SP14 to send a stop command signal OUT3 to the injection molding machine main body drive control device 6 and activate the alarm device 40. At the same time, the cursor K0 on the monitor 15 is displayed blinking.

Here, when an abnormality is determined in step SP7, it means that an abnormality such as "short mold", "remaining cavities", or "misalignment of slide core" has occurred in the injection molding machine main body 1 before protruding after mold opening. Accordingly, the operator removes the injection-molded product remaining in the injection-molding machine body 1 at step SP15, or performs recovery work such as repositioning the movable side mold 2 at a predetermined mounting position, and then performs injection molding. The operation of the machine body drive control device 6 is restarted.

On the other hand, when the abnormality is determined in step SP10 described above, it means that the injection molding machine main body 1 after the protrusion has "falling defect" and "pin break",
At this time, the operator restarts the operation of the injection molding machine main body drive controller 6 after performing recovery work such as removing the injection molded product remaining in the injection molding machine main body 1 or replacing the broken protruding pin in step SP15. Let

[3] Effects of the Embodiments According to the above configuration, only the luminance data that the monitoring device 7 cannot perform an effective determination operation is the video data input unit.
A state in which the monitoring device 7 cannot perform an effective determination operation by stopping the injection molding machine main body and issuing an alarm to the operator when it is no longer possible to take it into 11 ( That is, the injection molding machine main body 1 damages the mold while it is in the undecidable state),
It is possible to prevent occurrence of abnormal operation such as injection molding of a defective product.

[4] Other Embodiments (1) In the embodiment shown in FIG. 1, the embodiment in which the confirmation as to whether or not the judgment is possible is executed at step SP5 immediately after the mold opening is described. Instead, the brightness average value data BOP1 to BOP16, BDR1 in step SP11
Even if it is confirmed whether or not determination is possible after obtaining ~ BDR16, the same effect as in the above case can be obtained.

Incidentally, in the case of the embodiment of FIG. 1, the determination is made in step SP5 based on the brightness data obtained up to the previous injection molding cycle.
If the judgment of step SP11 is executed after step SP11, it can be judged whether or not it can be judged based on the luminance data obtained up to the injection molding cycle, and thus a judgment more suited to the current situation can be made. can do.

(2) In the above-described embodiment, the CPU 24 uses the step SP5
In making the determination, the change range rating data ΔDi (i = 1 to 16) for each of the plurality of monitoring areas A1 to A16 is used. However, these change range rating data ΔDi (i = 1 to 1) are used.
Even if the same data is used as part or all of 6), the same effect as the above case can be obtained.

(3) In the above embodiment, the brightness average value data BO
Multiple Pi (i = 1 to 16) and BDRi (i = 1 to 16) past N
Although the luminance data of one time is used, the luminance data of the past one time may be used.

(4) In the above-described embodiment, in determining whether the injection molding machine main body 1 is normal, the brightness data before the protrusion after mold opening is compared with the first rating reference data OP1 to OP16, and the protrusion is performed. The subsequent brightness data is the second rating reference data DR1 to D
I described the case of configuring to compare with R16,
Instead of this, the present invention can be applied to a case where it is determined whether or not the brightness is normal by directly comparing the brightness data after the mold opening and before and after the projection.

〔The invention's effect〕

As described above, according to the present invention, it is possible to surely determine in advance that the monitoring device will be unable to make a determination when the determination data that prevents the monitoring device from making an effective determination is captured. With such a configuration, it is possible to easily realize the monitoring method of the injection molding machine that can effectively avoid the possibility that a subsequent accident will occur.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of a method for monitoring an injection molding machine according to the present invention, FIG. 2 is a systematic connection diagram showing the overall configuration of the monitoring apparatus, and FIG. 3 is a method for setting a monitoring area. 4 is a schematic diagram showing the detailed structure of the RAM 32 of FIG. 2, FIG. 5 is a schematic diagram for explaining the undecidable range, and FIG. 6 is a conventional injection molding machine. 3 is a schematic system diagram showing the monitoring device of FIG. 1 ... Injection molding machine main body, 2 ... Movable side mold, 3 ... Fixed side mold, 6 ... Injection molding machine main body drive control device, 7 ... Monitoring device, 8 ... Television camera, 9 ... Monitoring Control device.

Claims (2)

(57) [Claims] 1. Based on the presence or absence of a change between first detection data indicating the brightness of a monitoring target after the mold opening and before the protrusion and second detection data indicating the brightness of the monitoring target after the mold opening after protruding. In a method of monitoring an injection molding machine for monitoring whether or not an abnormality has occurred in an injection molding operation of an injection molding machine main body, a value of the first determination data obtained based on the first detection data and a value of the second determination data. Second obtained based on detection data
The first step of making a first judgment as to whether or not the occurrence of the abnormality cannot be correctly judged due to the difference in the value of the judgment data being smaller than that of the change width evaluation data having a predetermined value; The value of the third determination data obtained based on the first detection data or the second detection data is higher than the upper limit rating data having a value lower than the full scale value that can be captured by a predetermined upper limit margin value. The second step of making a second judgment as to whether or not the monitored object becomes too bright to correctly judge the occurrence of the abnormality, and the first detection data or the second Occurrence of the above abnormality due to the value of the fourth determination data obtained based on the detection data becoming lower than the lower limit rating data having a value higher than the value when the brightness is 0 by a predetermined lower limit margin value. Positive And a third step of making a third judgment as to whether or not the monitoring target becomes too dark to make a negative judgment, and a negative judgment is made in any one of the first, second or third steps. When such a judgment result is obtained, it is judged that the monitoring operation for the occurrence of abnormality in the injection molding operation is impossible. A method for monitoring an injection molding machine, comprising: 2. The method of monitoring an injection molding machine according to claim 1, wherein the judgment operation is executed when the injection molding machine body performs an injection molding cycle operation.