JP2002321266A - Mold monitoring system and mold monitoring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold monitoring system which internally processes timely monitoring by the mold monitoring system and automates the setting of such appropriate time for monitoring the mold. SOLUTION: The system for monitoring the mold comprises a camera 9 which is positioned and fixed at a specified spot, an image analyzing means 32 which analyzes a photographic image photographed by the camera 9 and decides in which way a mold is transferred, in a mold opening direction or a mold clamping direction, based on a change in the photographic image, storage means 33 and 34 which store an inspection spot set in a transfer path of the mold in a clamped state and the photographic image at the inspection spot, and a comparison and decision means 36 which compares the photographic image at the inspection spot with a photographic image of a neighborhood of the same spot as shot previously and stored by the storage means 33 and 34 and decides to stop the mold when the comparison results show a non- coincidence between the photographic images.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a molded article remaining in a mold in a resin or metal molding machine and prevents the mold from being clamped while the molded article remains. TECHNICAL FIELD The present invention relates to a mold monitoring device and a mold monitoring method capable of performing the same.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Publication No. 60-5057
As described in Japanese Unexamined Patent Publication No. 3 (1999), a plurality of signal lines required for timing processing of a mold monitoring device from a molding machine such as an injection molding machine are connected to the mold monitoring device, and the timing is controlled by the plurality of signal lines. The signal is taken into the mold monitoring device, and the mold monitoring device monitors the mold according to the timing signal, and a command signal is output to the injection molding machine based on the monitoring result.

This will be described along the steps of an injection molding machine according to a timing chart shown in FIG. First, the resin is injected into the mold with the movable mold and the fixed mold of the injection molding machine closed, and when the injection is completed, the movable mold is moved by the mold opening signal a to perform mold opening b. Here, when the movable mold reaches the release position, the mold opening completion signal c is output to the mold monitoring device, and the mold monitoring device performs primary monitoring d and monitors whether or not all the molded products remain in the fixed mold. For this purpose, a movable video signal is captured from a camera of the mold monitoring device.

Next, the video signal is converted into luminance information,
The converted luminance information is compared with the reference luminance information, and if there is no problem in the comparison result, the mold monitoring device issues an ejection command signal e for dropping the molded product attached to the movable mold to the injection molding machine. Is output to The injection molding machine that has received the ejection command signal operates the ejection pin for peeling the molded product provided on the movable mold from the movable mold one or more times, and pushes the molded article from the movable mold.

When the ejection operation is completed, an ejection completion signal g is output from the injection molding machine to the mold monitoring device,
The die monitoring device that has received the protrusion completion signal performs secondary monitoring h of the movable die, and monitors whether or not a molded product remains in the movable die. For this purpose, as in the case of the primary monitoring, a movable video signal is fetched, converted into luminance information, and compared with a reference value. If there is no problem in the comparison result, the mold monitoring device outputs a mold closing command signal j to the injection molding machine, and the injection molding machine moves the movable mold and starts mold closing. This is the one-step operation of the injection molding machine and the mold monitoring device that has been conventionally performed.

[0006]

However, in the conventional case, the monitoring device starts monitoring after receiving a monitoring timing signal from the injection molding machine, makes a comparison judgment, and based on the result, causes the injection molding machine to perform the next operation. In order to proceed, the injection molding machine needs to synchronize its operation with the mold monitoring device. For this reason, there is a problem in that the processing time of capturing the video signal of the die monitoring apparatus, converting the video signal into luminance information, and comparing and judging is added, and the operation of the injection molding machine is delayed. Particularly in an injection molding machine, from the viewpoint of cost reduction of molded products, it is desired to produce many molded products in a short time. In addition, since there are a plurality of signal lines for signal control between the injection molding machine and the mold monitoring device, there are problems that the man-hour is required at the time of on-site installation and that a special technique is required. In addition, there is a demand for a mold monitoring apparatus that can automate the setting for monitoring a mold as much as possible and can perform highly reliable mold monitoring.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and reduces the time for timing processing, reduces the number of signal lines for timing processing, and monitors a mold instead of the signal lines. An object of the present invention is to provide a highly reliable mold monitoring apparatus and a mold monitoring method capable of processing monitoring timing of the apparatus in the mold monitoring apparatus and automating the setting for mold monitoring. I do.

[0008]

According to a first aspect of the present invention, there is provided a movable mold having a movable mold, a fixed mold, and a cavity. Is provided in a mold of an injection molding machine for molding a molded product by filling the cavity with a molten material in a state where the mold is clamped, and at least when the molded product is discharged from the mold when the mold is opened. In the mold monitoring device for monitoring, a camera positioned and fixed at a predetermined position and a photographed image taken by this camera are analyzed, and a change in the photographed image indicates whether the mold is moving in the mold opening direction or the mold closing direction. Image analysis means for determining whether or not the mold is moving, an inspection position set on the movement path of the mold with the mold closed, storage means for storing a photographed image near the inspection position, and the inspection while the mold is closed. The captured image near the position Compared with the stored one shot or shots before the same position near the photographed image in the storage means,
When the comparison result is inconsistent, a configuration is provided that includes a comparison determination unit that determines to stop the mold.

According to this configuration, it is possible to automatically determine the moving speed and the moving direction of the mold based on the luminance in the photographed image and the change in the shape of the specific portion. Therefore, by taking a photographed image at a predetermined inspection position and comparing the photographed image with a photographed image in the vicinity of the same position of the immediately preceding or a plurality of previous shots, the molded article can be reliably removed from the mold when the mold is closed. It is possible to determine whether or not it has been discharged.
That is, since the shot image at the same position one shot before or a plurality of shots before is used as the model image, it is not necessary to set the model image by manual input or the like, and it is possible to automate the setting for die monitoring. . Also, the signal exchange between the injection molding machine or the like and the mold monitoring device need only be a stop signal when it is determined that there is an abnormality, so that the number of signal lines can be greatly reduced, and the timing of monitoring can be almost completely reduced. Processing can be performed in the mold monitoring device.

[0010] The invention according to claim 2, wherein the storage means has an inspection position set on a moving path of the mold during mold opening;
The captured image near the inspection position is stored, and the comparison determination unit compares the captured image near the inspection position during mold opening with the captured image near the same position of the previous shot stored in the storage unit, When the comparison result is inconsistent, the molded product is determined to be defective. According to this configuration, the inspection can be performed not only when the mold is closed but also when the mold is opened, and it is possible to determine whether the molded product is a good product or a defective product.

According to a third aspect of the present invention, a photographed image with the mold open and a photographed image with the mold closed within the same shot are compared at the corresponding inspection positions, and based on the coincidence or non-coincidence of the two photographed images, whether the image is normal or not. The configuration is such that comparison determining means for determining an abnormality is provided. With this configuration, in addition to determining whether the molded article has been reliably ejected by comparing the previous shot with the photographed image, the molded image is compared with the photographed image when the mold is opened and the photographed image when the mold is closed. The discharge of articles can be confirmed, and a more reliable monitoring device can be obtained. In this case, as in the invention according to claim 4, the comparison determining means determines based on a comparison result between the photographed image during mold opening and the photographed image during mold closing in the same shot; When the judgment based on the comparison result between the photographed image and the photographed image near the same position of the previous shot stored in the storage means is inconsistent, the die may be stopped to notify the fact.

According to a fifth aspect of the present invention, the image analysis means takes an image of the mold moving in the mold opening direction or the mold closing direction at predetermined time intervals, and takes one photographed image immediately before another. The change amount of the photographed image is obtained by comparing with the photographed image, and the change amount of the photographed image is compared with the change amount of the immediately preceding photographed image. It is configured to determine that the moving speed has been switched from high speed to low speed or from low speed to high speed. The invention according to claim 6 determines the transition based on a difference in a change amount of a captured image, and
It is configured to determine whether the moving direction of the mold is the mold opening direction or the mold closing direction based on the sign of the difference. With this configuration, regardless of the molding machine,
The mold monitoring device can automatically determine a change in the mold moving direction and the mold moving speed.

According to a seventh aspect of the present invention, the amount of change in the photographed image is a change in luminance in the photographed image or a change in shape in the photographed image. Usually, when photographing an object to be photographed with a camera, illumination is used. Illumination light is reflected on the mold, which is the object to be photographed, to be photographed brightly, and the other parts are photographed darkly. Therefore, it is easy to determine the ratio of the luminance distribution (bright and dark distribution) in the captured image, and easily determine whether the mold is moving away from or close to the camera based on how this ratio changes. Become.
Further, the moving speed of the mold can be obtained from the degree of the transition, that is, the magnitude of the change in luminance.

According to an eighth aspect of the present invention, the inspection position of the photographed image is set within a low speed region of the mold moving speed. The captured image is sharper as the moving speed of the mold is lower. Therefore, more accurate inspection can be performed by performing the inspection in the low speed range.

According to a ninth aspect of the present invention, during the movement of the mold, a portion where the photographed image data is stably obtained in the photographed image is registered as a marker in the storage means, and the photographing of the marker is performed. The inspection position is determined based on the position in the image. Mold position,
For example, the distance from the origin set at the predetermined position can be obtained based on the position of an arbitrary point (marker) in the captured image. In order to accurately determine this position, it is preferable that the change in the position of the arbitrary point changes as much as possible as the mold moves. Therefore, it is possible to accurately determine the position of the mold by analyzing the lines and points in the captured image, the degree of change in the predetermined shape and luminance, and using the marker that changes the most as a marker. become. In addition, automatic selection of a marker and determination of an inspection position can be performed.

According to a tenth aspect of the present invention, the comparing and judging means compares the photographed images when the mold is opened or when the mold is closed with respect to a plurality of inspection positions, and obtains two or more inspection results at the plurality of inspection positions. Are determined to be normal or abnormal when are continuously the same. In this way, by repeating the process for checking a plurality of times, it is possible to avoid the operation stop of the molding machine due to erroneous determination as much as possible.

An object of the present invention is to provide a molded product having a movable mold, a fixed mold, and a cavity, wherein the cavity is filled with a molten material in a state where the movable mold and the fixed mold are clamped. Provided in a mold of an injection molding machine for molding, at least, in a mold monitoring method for monitoring whether the molded product is discharged from the mold when the mold is opened, a camera fixed at a predetermined position, The step of photographing the mold during the mold opening or the mold closing and the photographed images photographed by the camera are sequentially compared, and the mold is moving in the mold opening direction or moving in the mold closing direction from a change in the photographed image. A step of determining whether the mold is in the middle, a step of setting the inspection position on the movement path of the mold during the mold opening and the mold closing, and a photographed image near the inspection position during the mold opening, the same position of the previous shot. Compare with the nearby image and before closing the mold The present invention can also be achieved by a mold monitoring method including a step of comparing a photographed image near the inspection position with a photographed image near the same position of the previous shot and a step of determining that the image is normal when the comparison result matches. .

According to this method, normal or abnormal is determined while comparing the image taken before one shot or a plurality of shots as a model image while the mold is opened and when the mold is closed. It is not necessary to photograph the model image to be registered in the memory in advance, and the work for the inspection can be simplified. In addition, since the operation of creating a model image can be omitted, the operation rate of a molding machine or the like does not decrease.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing a state in which a cavity of a movable mold is formed by a camera according to an embodiment of the mold monitoring apparatus of the present invention, and FIG. 2 is a camera and a photograph taken by the camera. FIG. 4 is a perspective view showing a surface of a movable mold on which a cavity is formed.

As shown in FIG. 1, the mold of the injection molding machine 1 has a fixed mold 2 and a movable mold 3. The movable mold 3 moves forward and backward while being guided by the tie bar 4, and the fixed mold 2 is clamped and opened. A cavity formed between the fixed mold 2 and the movable mold 3 is filled with a molten material from a nozzle 5 provided in the fixed mold 2 in a clamped state. After the material filled in the cavity is solidified and cooled, the movable mold 3 moves along the tie bar 4 in the mold opening direction. When the movable mold 3 moves rearward (to the left in FIG. 1) and comes into contact with the projecting portion 7, the projecting pin 8 provided on the movable mold 3 is advanced by the projecting portion 7,
The molded product is protruded from the movable mold 3. After the protrusion of the molded product, the movable mold 3 is moved forward (to the right in FIG. 1) to perform mold clamping.

As shown in FIG. 2, the mold of this embodiment has six molds, and six cores are formed on the inner surface of the movable mold 3 in accordance with the six molded products 13 to 18 to be molded. A part is formed. A camera 9 for photographing the inner surface of the movable mold 3 is positioned and fixed in the vicinity of a moving path along which the movable mold 3 moves. It is preferable that the camera 9 is positioned and fixed such that at least all of the six core portions and the molded products 13 to 18 are within the photographing screen during the movement of the movable mold 3. Further, in order to make the captured image of the movable mold 3 clear, it is preferable to provide a lighting device such as a lamp in parallel.

Further, the camera 9 has a CCD type or M-type which can output data of a photographed image as binary data.
This is a camera having an OS type image sensor. Camera 9
It may be either color or monochrome, but monochrome is advantageous in that the image processing speed is faster. Further, the camera is not limited to a camera using a CCD type or MOS type image pickup device, but may be a camera that outputs a captured image as an analog signal. In this case, an A / D converter for converting an analog signal into a digital signal may be provided.

FIG. 3 is a block diagram of a mold monitoring apparatus according to the present invention. The mold monitoring device is a model image that is used as a reference when checking whether the molded product is properly molded when the mold is opened and whether the molded product is securely discharged from the mold when the mold is closed. A model image creation unit I for creating
And an inspection unit II for actually performing an inspection. Camera 9
The image photographed by is input to the first image processing unit 30a of the model image creation unit I and the second image processing unit 30b of the inspection unit II.

[Model Image Creation Unit I] The model image creation unit I includes a first image processing unit 30a, a working memory 31, an image analysis unit 32, a primary memory 33, and a secondary memory 34.
Etc. The first image processing unit 30a includes, for example,
The captured images extracted at preset time intervals are input to the working memory 31 and also to the image analysis unit 32 that analyzes the brightness distribution of the captured images, the shapes included in the images, and the like. In the working memory 31, the captured images input at predetermined time intervals are sequentially accumulated. In the image analysis unit 32, a certain time Tn (n = 1, 2, 3,...)
The photographed image captured in step (1) is compared with the photographed image immediately before in the working memory 31, that is, the photographed image at time Tn-1, and the amount of change is determined. The contents to be compared include, for example, the luminance and the shape in the captured image.

This will be described with reference to FIG. FIG.
FIG. 5A is a diagram showing a relationship between the position of the movable mold 3 and an image photographed by the camera 9, and FIG.
5 (b) shows a photographed image. The positions indicated by in FIG. 5A correspond to the captured images indicated by in FIG. Also, in FIG.
The range within the frame indicated by 95 is a photographed image at the position photographed by the camera 9. The mold 3 shown in FIG.
It is assumed that the robot moves at a high speed within the range indicated by and moves at a low speed within the range indicated by.

When the movable mold 3 is moving at a high speed in the mold opening direction, the movable mold 3 rapidly moves away from the camera 9, so that the size of the movable mold 3 in the captured image is rapidly reduced. Become. Since the camera 9 is usually provided with illumination for photographing, the movable mold 3 that reflects the illumination light is provided.
Are bright in the captured images 91 to 95, and the other portions appear dark. Therefore, the captured images 91 to 9
By analyzing the degree of lightness and darkness in 5, it is possible to analyze the luminance distribution in the captured images 91 to 95 at the respective positions. And, based on the luminance distribution of each position ~
The position, the position, the position, and the magnitude of the luminance change at the position can be obtained. These are referred to as luminance change amounts C1, C2, C3, and C4.

When the movable mold 3 is moving at high speed, the change in luminance is large, and when the movable mold 3 moves at low speed, the change in luminance is small. In FIG. 5, the change of the luminance change amount is represented by a difference δ1, δ2, δ3 (δ1 = C1-C2, δ2 = C2-C3, δ3 = C3 when the mold is opened).
−C4, δ1 = C2-C1, δ2 = C3-C when the mold is closed
2, δ3 = C4-C3). Image analysis unit 32
Can be determined that the movable mold 3 has changed from high speed to low speed at the portion of δ1 where the difference in the amount of change in brightness is the largest, that is, at the position. Furthermore, the difference δ1, δ2, δ
Whether the movable mold 3 is moving in the mold opening direction or the mold closing direction can be determined from the sign of the mold 3.

Next, the image analysis unit 32 searches for a portion where the amount of change in the shape or the amount of change in the position in the captured image is remarkable in the captured image in the low-speed region. For example, the image analysis unit 32 focuses on horizontal horizontal lines in the captured images 92 to 95 as shapes, and selects the upper edge 3a of the movable mold 3 having the largest change amount. The image analysis unit 32 includes a pin 1
Focusing on the positions 9 and 20, it is also possible to select the pins 19 whose distance from the origin in the captured image (the positional relationship with respect to the origin) changes significantly. And, according to the above-mentioned example, the shape of the upper edge 3a of the movable mold 3 or the position of the pin 19 is used as a marker for each position or position. decide. This marker is used when determining an inspection position which is a reference position when performing an inspection.

The image analysis unit 32 stores the captured images 92 to 95 of the position of the low-speed area during the mold opening in the primary memory 33 as a model image.
Is stored in the primary memory 33. Similarly, the position of the low-speed region during mold closing
Are stored in the secondary memory 34 as model images, and the marker selected at the position 1 is stored in the secondary memory 34.

As shown in FIG. 4, the memory areas of the primary side memory 33 and the secondary side memory 34 are stored in the immediately preceding shot (a series of operations for forming a molded product is described as "shot"). Area 33 for storing created model image
a (34a) and an area 33b (34b) for storing the model image created by the current shot. In the inspection of the current shot (hereinafter, this shot), the previous shot (hereinafter, this shot)
Model image, ie, the region 33a (34)
The model image stored in a) is used, and the model image created in the current shot is used in the inspection of the next shot (hereinafter, referred to as the next shot). As the marker, the marker selected in the inspection shot performed immediately after the start of the operation of the molding machine may be used as it is after the next shot.

[Inspection Unit II] The inspection unit II has a second image processing unit 30b, a reading unit 35, and a comparison judging unit 36. The reading unit 35 reads a captured image (model image) from the inspection position to the primary memory 33 or the secondary memory 34 and sends the image to the comparing / determining unit 36. The second image processing unit 30b compares the marker for each of the inspection positions stored in the primary memory 33 or the secondary memory 34 with the shape or position of the corresponding part of the captured image captured by the camera 9, When the two coincide, it is determined that the movable mold 3 has reached the inspection position. Then, the captured image at that time is sent to the comparison / judgment unit 36.

In the comparison / judgment section 36, when the movable mold 3 being photographed by the camera 9 is moving in the mold opening direction,
The model image of the primary memory 33 and the second image processing unit 3
0b is compared with the captured image. When the movable mold 3 is moving in the mold closing direction, the model image in the secondary memory 34 is compared with the photographed image sent from the second image processing unit 30b. As a result, when they match, it is determined that the molded state of the molded article and the ejection of the molded article have been performed normally. If they do not match, it is determined that the molding of the molded article is abnormal or that the molded article has not been discharged. If it is determined in the inspection during the mold opening that there is an abnormality, the mold opening operation is continued and the movable mold 3 is opened.
The molded product taken out from is processed as a defective product. If the inspection during mold closing is determined to be abnormal, the mold closing operation is immediately stopped.

In order to prevent the movable mold 3 from being stopped due to an erroneous judgment and to treat a non-defective product as a defective product, it is preferable to perform the comparison judgment work a plurality of times. For example, only when it is determined that both the two or more consecutive inspection positions, for example, both consecutive inspection positions are abnormal, a command to process the molded product as a defective product or to stop the movement of the movable mold 3 is issued. It is also possible to configure to output. Further, in this embodiment, for convenience of explanation, the number of inspection positions has been described as being four, but this number is arbitrary, and it goes without saying that the number may be four or more.

[Other Embodiments] Next, another embodiment of the present invention will be described with reference to FIG. FIG. 6 is a block diagram of a mold monitoring device according to another embodiment of the present invention. In this other embodiment, a model image created at each of the inspection positions when the mold is opened is compared with a photographed image at the position of the movable mold 3 when the mold is closed corresponding to the inspection position. ing. As shown in FIG. 6, the mold monitoring device of this embodiment extracts a photographed image when the mold is closed based on the inspection position of the current shot stored in the primary memory 33 when the mold is opened. It has an image processing unit 30c. Further, in addition to the first reading unit 35a for reading the model image created in the previous shot from the primary memory 33 or the secondary memory 34, the model image (model 33b in FIG. Has a second reading unit 35b for reading the model images 92 to 95) stored in the primary memory 33.

Further, in addition to the first comparison / determination section 36a for comparing the model image of the previous shot read by the first reading section 35a with the photographed image of the current shot, the second reading section 35b reads the model image. And a second comparison / determination unit 36b for comparing the model image of the current shot when the mold is opened with the photographed image of the current shot when the mold is closed. When the comparison results of the two images in the second comparison judging section 36b match, a command to stop the mold closing operation is output by judging that the molded article has not been discharged, that is, abnormal.

As described above, the photographed image at the time of mold opening and the photographed image at the time of mold closing in the same shot are compared, and when it is determined that there is an abnormality, the mold closing operation is immediately stopped, thereby further improving the reliability of the inspection. Can be enhanced. Also in this embodiment, the comparison between the photographed image when the mold is opened and the photographed image when the mold is closed in the same shot is performed at a plurality of inspection positions, and when the coincidence determination is performed twice or more consecutively. In addition, it is also possible to stop the movable mold 3 by determining that it is abnormal.
By doing so, it is possible to avoid an operation stop due to an erroneous determination.

[Die Monitoring Method] Next, the die monitoring method of the present invention will be described with reference to the flowchart of FIG. In the following description, the mold monitoring device shown in FIGS. 3 to 5 will be referred to as appropriate. The monitoring work starts with the start of the mold opening operation (step S1).
0). The camera 9 constantly photographs the mold (step S
11). A timer or the like (not shown) counts the time (step S12), and when the time is up (step S13), the first image processing unit 30a stores the image at the time up in the working memory 31 as a photographed image. Remember.

The image analysis unit 32 compares the latest photographed image at the time-up with the previous photographed image at the time-up stored in the working memory 31 and determines the luminance variation (Cn). It is obtained by calculation (step S15). Next, the image analysis unit 32 obtains a difference δn in the amount of change in luminance. The difference δn in the luminance change amount can be obtained by subtracting the immediately preceding luminance change amount Cn−1 from the luminance change amount Cn obtained in step S15. Then, it is possible to determine whether the movable mold 3 is moving at a high speed or at a low speed based on the difference δ of the luminance change amount. In addition, it is possible to determine whether the moving direction is the mold opening direction or the mold closing direction based on whether the sign of the luminance change amount δ is positive or negative (steps S17 and S18).

Since the flowchart shown in FIG. 7 is for when the mold is opened, when it is determined that the moving direction is the mold closing direction, the flow for closing the mold is executed (step S17).
In addition, since what is at the time of mold closing is basically the same as that at the time of mold opening shown in FIG. 7, illustration and detailed description are omitted here. If it is determined in step S17 that the moving direction of the movable mold 3 is the mold opening direction, the process proceeds to step S1.
8 and below are executed. Next, on condition that the moving speed of the movable mold 3 is low (step S18), the image analysis unit 32 searches for a portion where the shape change is remarkable from the captured image (step S19). Then, when the relevant portion is found (step S20), the relevant portion is registered as a marker (step S21), and the inspection position (corresponding to the position of FIG. 5B) is determined based on the marker (step S21). Step S22).

Further, each inspection position is associated with a photographed image and stored in the primary memory 33 as shown in FIG. The captured image stored in this manner is a model image that is used as a basis for inspection in the next shot (step S
25). If the corresponding part is not found (step S20), the worker is notified by an alarm or the like (step S2).
3) Prompt for manual input of inspection position (step S2)
4). The inspection position thus set is also stored in the primary memory 33 together with the corresponding photographed image.

The second image processing section 30b reads out the inspection position created in the previous shot and stored in the primary memory 33, and determines that the movable mold 3 has reached this inspection position (step S26), and send the photographed image at the inspection position to the comparison / determination unit 36. On the other hand, the reading unit 35 reads the model image at the time of opening the mold created by the previous shot from the primary memory 33 (step S27), and sends the model image to the comparison determining unit 36. The comparison determining unit 36 compares the captured image sent from the second image processing unit 30b with the model image read by the reading unit 35 (step S28).
It is determined whether the two images match (step S2).
9).

The comparing and judging section 36 compares the photographed image and the model image in order for each of the corresponding inspection positions.
If the coincidence determination between the captured image and the model image is performed twice consecutively (step S30), it is determined that the image is normal and the molding operation is continued (step S32). If the mismatch between the captured image and the model image is determined twice consecutively (step S3
1) It is determined to be abnormal (step S33), and the molded product formed by the shot is processed as a defective product. In addition,
If it is determined that there is an abnormality at the time of closing the mold, the movable mold 3 is immediately stopped at that time, and the operator is notified of the abnormality. Thus, the processing for one cycle is completed (step S4).
0).

[Other Embodiment of Die Monitoring Method] Next, another embodiment of the die monitoring method will be described with reference to the flowchart of FIG. In this embodiment, in addition to the processing according to the flowchart in FIG. 7, the processing according to the flowchart in FIG. 8 is additionally performed. In other words, the respective photographed images are compared at the inspection positions corresponding to the time when the mold is opened and the time when the mold is closed in the same shot, and when the two coincide, it is determined that the molded product has not been discharged from the movable mold 3. The movable mold 3 is stopped. In the following description, the block diagram of the die monitoring device shown in FIG. 6 will be referred to as appropriate.

Step S17 in the flowchart of FIG.
Then, when it is determined that the moving direction of the movable mold 3 is the mold closing direction, the processing of this embodiment is started (Step S).
50). The second image processing unit 30b reads the inspection position determined in the current shot from the primary memory (step S
51), it is determined whether or not the movable mold 3 has reached the inspection position (step S52). If the movable die 3 has reached the inspection position, the captured image at that time is compared with the second comparison determination unit 36b. (Step S53). Next, the second reading unit 35b reads the model image created at the time of opening the mold of the current shot from the primary memory 33 (Step S).
54), and sends it to the second comparison / determination unit 36b (step S5).
5).

The second comparison / determination unit 36b compares the two images (step S56) and determines whether they match (step S57). If the two images match, it is determined that the molded product has not been ejected from the movable mold 3, that is, it is determined to be abnormal (step S59), and the movable mold 3 is immediately stopped (step S60). If the two images do not match, it is determined that the image is normal and the subsequent molding is continued (step S5).
8). Thus, the process ends (step S61). Also in this embodiment, when the coincidence determination of the two images is performed twice or more consecutively, it is possible to determine that there is an abnormality and stop the movable mold 3.

Although the preferred embodiments of the present invention have been described, the present invention is not limited to the above embodiments. For example, in the description of the above embodiment and FIGS. 3 and 6, for convenience of explanation, it is assumed that there are a plurality of memories, an image processing unit, a reading unit, and a comparison determining unit, but these are a common memory, an image processing unit, It may be a reading section, a comparing / determining section, or the like, or a single processing device may include these functions.

In the above description, the inspection for monitoring the mold is performed both when the mold is opened and when the mold is closed. However, it is only necessary to monitor whether or not the discharge of the molded product is performed reliably. , The above processing may be performed only when the mold is closed. Further, in the above description, the model image one shot before and the shot image of the current shot are compared. However, the comparison may be made using the model images of a plurality of shots before. . Note that, as in the above-described embodiment, there is an advantage that by creating a model image based on the previous shot, it is possible to adapt to environmental changes in order to make an accurate determination. In addition, as a portion in which captured image data is stably obtained in a captured image, a change in luminance, a change in shape, or a change in position is described as an example.
Any other data may be used as long as the captured image data can be obtained stably.

[0048]

According to the present invention, the mold monitoring device can be made almost completely independent of the injection molding machine and the mold. That is, since the mold monitoring device independently determines the inspection timing, a signal line for transmitting the inspection timing signal from the injection molding machine to the mold monitoring device is not required. In addition, it is possible to automate the setting of the model image and the inspection position for performing the inspection, and the setting work for the inspection becomes almost unnecessary. Further, since the operation state is monitored by comparing the photographed images, it is possible to monitor not only defective discharge of the molded product but also defective molded products such as defective casting. Furthermore, it is possible to monitor the mold in both the mold opening direction and the mold clamping direction, and in this way, whether the molded product is reliably removed from the movable mold at the time of mold clamping. In addition to the monitoring, it is also possible to monitor whether the transfer of the molded article from the fixed mold to the movable mold at the time of opening the mold is surely performed.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a mold monitoring device according to the present invention,
It is a top view which shows a mode that the surface where the cavity of the movable metal mold was formed is imaged with a camera.

FIG. 2 is a perspective view showing a camera and a surface on which a cavity of a movable mold photographed by the camera is formed.

FIG. 3 is a block diagram of a mold monitoring device of the present invention.

FIG. 4 is a diagram illustrating memory areas of a primary memory and a secondary memory.

5A and 5B are diagrams illustrating a relationship between a position of a movable mold and an image captured by a camera. FIG. 5A illustrates a position of the movable mold, and FIG. 5B illustrates a captured image. ing.

FIG. 6 is a block diagram of a mold monitoring device according to another embodiment of the present invention.

FIG. 7 is a flowchart illustrating an embodiment of a mold monitoring method according to the present invention.

FIG. 8 is a flowchart for explaining another embodiment of the mold monitoring method of the present invention.

FIG. 9 is a diagram illustrating a timing chart of a mold monitoring device according to a conventional example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection molding machine 2 Fixed mold 3 Movable mold 4 Tie bar 5 Nozzle 7 Projection section 8 Projection pin 9 Camera 13-18 Molded product 30a First image processing section 30b Second image processing section 30c Third image processing section 31 working memory 32 image analysis unit 33 primary memory 34 secondary memory 35 reading unit 36 comparison and judgment unit 91-95 photographed image

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiko Inoue 658, Nishinomiya-cho, Naka-gun, Kanagawa Prefecture (72) Inventor Yoshiaki Nakanishi 2-13-10 Shibusawa, Hadano-shi, Kanagawa F-term (reference) 4F202 AM04 AM09 AM22 AP06 AR07 CA11 CB01 CS07 4F206 AM04 AM19 AM22 AP06 AP07 AR07 JA07 JL02 JP05 JP15 JP30

Claims (16)

[Claims] 1. An injection molding machine having a movable mold, a fixed mold, and a cavity, wherein the cavity is filled with a molten material in a state where the movable mold and the fixed mold are clamped. In a mold monitoring device provided in a mold of a molding machine and monitoring whether or not the molded article has been discharged from the mold at least when the mold is opened, a camera fixed and positioned at a predetermined position, Image analysis means for analyzing the photographed image and determining whether the mold is moving in the mold opening direction or the mold closing direction based on a change in the photographed image; and a moving path of the mold during mold closing. Inspection position set above, storage means for storing a captured image at this inspection position, and a captured image at the inspection position during mold closing, a captured image near the same position of the previous shot stored in the storage means Compare and compare this And a comparison determining means for determining whether to stop the mold when the results do not match each other. 2. The storage means stores an inspection position set on a movement path of a mold during mold opening, and a photographed image in the vicinity of the inspection position. The captured image near the position is compared with the captured image near the same position of the previous shot stored in the storage unit,
The mold monitoring apparatus according to claim 1, wherein when the comparison result is inconsistent, the molded article is determined to be defective. 3. A comparison judgment for comparing a photographed image during mold opening and a photographed image during mold closing in the same shot in the vicinity of a corresponding inspection position, and judging normality or abnormality based on coincidence / mismatch of both photographed images. The mold monitoring device according to claim 1 or 2, further comprising means. 4. The comparison determining means determines based on a comparison result between a captured image during mold opening and a captured image during mold closing in the same shot, and stores the captured image during mold closing and the storage means. The die monitoring apparatus according to claim 3, wherein when the determination based on the comparison result of the previous shot with the photographed image at the same position is inconsistent, the die is stopped and the effect is notified. 5. The image analysis means captures an image of a mold moving in a mold opening direction or a mold closing direction at predetermined time intervals, and compares one captured image with another immediately preceding captured image. The amount of change in the image is obtained, the amount of change in the captured image is compared with the amount of change in the immediately preceding captured image, and when the change in the amount of change greatly changes, the moving speed of the mold is changed from high speed to low speed or 2. The method according to claim 1, wherein the determination is made that the speed has been switched from a low speed to a high speed.
The mold monitoring device according to any one of claims 1 to 4. 6. The method according to claim 1, wherein the transition is determined based on a difference in a change amount of the captured image, and whether the moving direction of the mold is a mold opening direction or a mold closing direction is determined based on the sign of the difference. The die monitoring apparatus according to claim 5, wherein 7. The mold according to claim 1, wherein the amount of change in the photographed image is a change in luminance in the photographed image or a change in shape in the photographed image. Monitoring method. 8. The die monitoring apparatus according to claim 1, wherein the inspection position of the photographed image is set within a low-speed region of the die moving speed. 9. A part in which the photographed image data is stably obtained in the photographed image is registered as a marker in the storage means while the mold is moving, and a position of the marker in the photographed image is determined based on the position of the marker in the photographed image. The die monitoring apparatus according to claim 1, wherein the inspection position is determined. 10. The comparing and judging means compares the photographed images when the mold is opened or when the mold is closed with respect to a plurality of inspection positions, and two or more inspection results are continuously the same at the plurality of inspection positions. The mold monitoring apparatus according to any one of claims 1 to 9, wherein when it is determined that the state is normal or abnormal. 11. An injection molding apparatus having a movable mold, a fixed mold, and a cavity, wherein the cavity is filled with a molten material in a state where the movable mold and the fixed mold are clamped to form a molded product. A mold monitoring method that is provided on a mold of a molding machine and monitors whether or not the molded article has been discharged from the mold when the mold is opened, with a camera fixed at a predetermined position, during mold opening or The step of photographing the mold while the mold is closed, and sequentially comparing the photographed images photographed by the camera, and determining whether the mold is moving in the mold opening direction or moving in the mold closing direction based on a change in the photographed image. Determining, and setting the inspection position on the movement path of the mold during mold opening and mold closing, the photographed image near the inspection position during mold opening, the photographed image at the same position of the previous shot Comparison and near the inspection position during mold closing And comparing the captured images of the same position before the shot the definitive captured image, when the comparison result matches, die monitoring method characterized by having a step of determining as normal. 12. A step of comparing a photographed image during mold opening and a photographed image during mold closing within the same shot at corresponding inspection positions, and judging normality or abnormality based on the coincidence / mismatch of the two photographed images. The mold monitoring method according to claim 11, further comprising: 13. The image analysis means photographs a mold moving in a mold opening direction or a mold closing direction at predetermined time intervals, and compares one photographed image with another immediately preceding photographed image. The amount of change in the image is obtained, the amount of change in the captured image is compared with the amount of change in the immediately preceding captured image, and when the change in the amount of change greatly changes, the moving speed of the mold is changed from high speed to low speed or 12. The die monitoring method according to claim 10, wherein it is determined that the speed has been switched from a low speed to a high speed. 14. The mold according to claim 11, wherein the change amount of the photographed image is a change amount of luminance in the photographed image or a change amount of a shape in the photographed image. Monitoring method. 15. A part in which captured image data is stably obtained in a captured image captured in the memory while the mold is moving is registered in the memory as a marker, and the marker is included in the captured image in the captured image. The method according to any one of claims 11 to 14, wherein the inspection position is set based on the position. 16. The photographed image at the time of mold opening or mold closing is compared for a plurality of inspection positions, and when two or more inspection results are continuously the same at the plurality of inspection positions, a normal or normal state is determined. The method according to any one of claims 11 to 15, wherein the method is determined to be abnormal.