JPH07323429A - Method and device for die-monitoring - Google Patents

Abstract

PURPOSE:To comply with a change in external environments, inhibit the generation of a faulty interpretation, and detect correctly and accurately the presence of a molding in a die without a false operation. CONSTITUTION:A die 1 after its opening, and a die 1 wherein a molding removal step has been finished are photographed using a camera 8 at a predetermined position and from in a predetermined direction, and their images are stored in photographed image memory 14-2, 14-1. The difference between the photographed image data of the die 1 after it opening and that of the die 1 wherein a molding removal step has been finished is obtained, and a histogram is prepared based on the difference. Further, the presence of a molding in the die is interpreted, for example, based on (1) data, of the binary coded data comprising two levels (1) and (0) obtained by binaryzing the histogram using a threshold value as a standard.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold monitoring apparatus and method for monitoring the presence / absence of a molded product after molding in a mold used for a molding apparatus for plastics and the like.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing a case where a mold is monitored in a general injection molding apparatus (for example,
JP-B-58-4616 or JP-A-4-13823
(See No. 5). In FIG. 4, 1 is a movable mold, 2 is a fixed mold, 3 is a tie bar, 4 is a cylinder, 5 is a protruding part,
6 is a protruding pin, 7 is a molded product, 8 is a television camera (hereinafter, simply referred to as a camera) as an imaging means, and 9 is an image processing system. The movable side mold 1 is shown along the tie bar 3 in the figure. It is configured to move in the direction indicated by arrow A.

The image processing system 9 also compares the image data from the camera 8 with preset first and second reference image data to determine the degree of coincidence between the captured image data and the reference image data. Here, the first reference image data refers to image data obtained by previously capturing an image of the movable-side mold 1 that is mounted on the molding apparatus and before molding. On the other hand, the second reference image data is image data obtained by previously capturing an image of the movable mold 1 that holds the molded product 7 in a good state at the time of opening the mold after molding.

In this injection molding apparatus, with the movable mold 1 and the fixed mold 2 clamped, resin is injected by the cylinder 4 into the cavity formed by both molds 1, 2.
Molding is performed. Then, after the resin is cooled, the mold opening in the state as shown in FIG. 4 is performed. At this time, the molded product 7 is held by the movable mold 1 and moved to a predetermined position.

The camera 8 is fixed at a position where the molded product holding surface of the movable side mold 1 at the mold opening completion position can be imaged from a predetermined position and direction, and when the mold opening is completed, the camera 8 is fixed. The movable die 1 is imaged by 8. Image data captured by the camera 8 at this time is input to the image processing system 9 and compared with preset second reference image data to determine the degree of coincidence between the two.

As a result of the judgment, when it is considered that the picked-up image data substantially coincides with the second reference image data, it is judged that the molded product 7 does not remain in the fixed-side mold 2 and that the mold opening is properly performed. Then, the process proceeds to the next molded product removing step.

On the other hand, when the image processing system 9 determines that the picked-up image data is different from the second reference image data, the molded product 7 remains in the stationary mold 2 and remains as it is. When the next mold clamping is performed through the molded product taking out process, the mold work may be stopped because the mold may be damaged due to an unreasonable force acting on the mold.

When the process moves to the next step of taking out the molded product, the projecting portion 5 is moved to the right in the figure, and the projecting pin 6 provided on the movable mold 1 is pushed to the right. As a result, the molded product 7 is projected from the movable mold 1. Molded product 7
When the protrusion of is completed, the protrusion 5 is moved to the left and returned to its original position. Here, the molded product 7 is taken by the camera 8.
The movable die 1 is imaged after the is ejected. Image data captured by the camera 8 at this time is input to the image processing system 9 and compared with preset first reference image data to determine the degree of coincidence between the two.

As a result of the judgment, when it is considered that the picked-up image data substantially coincides with the first reference image data, the molded product 7 does not remain in the movable side mold 1 and the molded product 7 is projected well. This is judged to be the case, and the process moves to the next mold clamping process.

On the other hand, when the image processing system 9 determines that the picked-up image data is different from the first reference image data, the molded product 7 remains in the movable mold 1 and remains as it is. If the mold is clamped at, there is a possibility that the mold may be damaged due to an unreasonable force acting on the mold, so that the molding operation is stopped.

As described above, by using the mold monitoring device, the movable mold 1 and the fixed mold 2 can be accurately monitored in a short time without damaging the mold.

[0012]

By the way, in the above-mentioned conventional apparatus, as a method for setting the reference image data,
The first reference image data is obtained by previously capturing the image of the movable side mold 1 that is mounted on the molding device and before molding, and is in a good state when the mold is opened after the first molding. By capturing an image of the movable mold 1 holding the molded product 7 in advance, the second reference image data is obtained.
After that, the method of using these as fixed data is adopted. Therefore, when the external environment for obtaining the captured image data that is the comparison target of these fixed reference image data gradually changes, the old fixed reference image data cannot follow this new external environment change, and the normal type There is a problem that even if the molded product is opened and the molded product is ejected, it is determined to be abnormal. In addition, there is a problem that an erroneous determination that is erroneously determined is likely to occur when there is a large luminance unevenness or the like on the die surface.

The present invention has been made in view of the above circumstances, and an object thereof is not only to be able to follow changes in the external environment, but also to prevent erroneous determination from occurring and to detect the presence / absence of a molded product in a mold. It is an object of the present invention to provide a die monitoring apparatus and a method therefor that can be performed accurately and accurately without the need.

[0014]

In order to achieve the above object, the mold monitoring apparatus of the present invention has a mold after opening a mold and a predetermined position of the mold after a molded product removing step, After the image pickup means for picking up images from the direction, the first data holding means for holding the imaged image data of the mold after mold opening obtained by the image pickup means, and the step of taking out the molded product obtained by the image pickup means Based on the difference between the image data held by the second data holding means and the image data held by the second data holding means. Binarization processing is performed on the histogram based on a predetermined threshold value, and the data at any one of the two levels of the binarized data is compared with the data in a predetermined area of the captured image data. do it And a judging means for judging whether the molded article.

According to the mold monitoring method of the present invention, the mold after the mold opening and the mold after the molding product take-out step are imaged from a predetermined position and direction, and the mold is imaged after the mold opening. The difference between the image data and the imaged image data of the mold after the molded product taking out step is obtained, a histogram based on the difference is created, and the histogram is binarized based on a predetermined threshold value. The presence / absence of a molded product in the mold is determined based on the data at any one of the two levels of binary data.

[0016]

According to the mold monitoring apparatus of the present invention, when the molding is completed in the mold clamped state, the mold is opened. The mold image after the mold opening is picked up by the image pickup means, and the picked-up image data is held in the first data holding means. Next, the molded product is taken out from the mold after opening the mold, and when the process of taking out the molded product is completed, the image of the mold after the removal of the molded product is captured by the image pickup means, and the captured image data is the second image data.
Is held by the data holding means of. The image data held in the first and second data holding means is input to the judging means. The determination means performs binarization processing on the histogram based on the difference between the two input image data with a predetermined threshold value as a reference. And two levels, "0",
Any one of the binary data that takes "1",
For example, the presence / absence of a molded product in the mold is determined based on the data of "1".

Further, according to the mold monitoring method of the present invention, first, the mold after opening the mold and the mold after the molding product take-out step are imaged from a predetermined position and direction. Next, the difference between the imaged image data of the mold after opening the mold and the imaged image data of the mold after the molded product takeout step is obtained, and subsequently a histogram based on this difference is created. Then, the histogram is binarized based on a predetermined threshold value, and the presence or absence of a molded product in the mold is determined based on the data at any one of the two levels of the binarized data. It

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of a mold monitoring device and an injection molding device according to the present invention.
The same components as those of the conventional example shown in FIG. 4 are designated by the same reference numerals. That is, 1 is a movable side mold, 2 is a fixed side mold, 3 is a tie bar, 4 is a cylinder, 5 is a protruding portion, 6 is a protruding pin, 7 is a molded product, and 8 is a camera (television camera) as an imaging means. 10 is analog / digital (hereinafter referred to as A / D
A converter, 11 is a control circuit, 12 is the latest image memory, 13 is a program memory, 14-1 and 14-2.
Represents a captured image memory, and 15 represents a difference memory.

The A / D converter 10 converts analog image data obtained by the camera 8 into digital image data,
Output to the control circuit 11.

The control circuit 11 stores or reads the latest digital captured image data IMD input from the A / D converter 10 into or from the latest image memory 12, reads desired data from the program memory 13, and the A / D converter. 1
The digital captured image data IMD input from 0 is stored in or read out from the captured image memories 14-1 and 14-2, and the difference data between the captured image data IMD1 and IMD2 stored in the captured image memories 14-1 and 14-2. D
Calculation of EF and storage in the difference memory 15, generation of a threshold value from a histogram based on the calculated data to obtain difference data D
The EF is binarized, only the "1" data of the binarized data DEF (i) is recognized, the presence or absence of a molded product in the mold after mold opening is determined based on the recognition data, and the determination result Based on the above, processing such as continuing or stopping the molding operation is performed.

The control circuit 11 includes a picked-up image memory 14-1.
The image data IMD1 of the movable mold 1 after the mold is opened in the molding process and the protrusion of the molded product 7 is completed is stored in the table. On the other hand, the captured image memory 14-2 stores the captured image data IMD2 of the movable mold 1 immediately after the mold is opened in the molding process.

FIG. 2 is a flow chart showing a data preparation procedure for determining the presence / absence of a molded product in the mold of the control circuit 11.

First, imaged image data IM of the movable side mold 1 after being imaged by the camera 8 and opening the mold in the molding process via the A / D converter 10 to complete the protrusion of the molded product 7.
D1 and the captured image data IMD2 of the movable side mold 1 immediately after the mold is opened in the molding process are stored in the captured image memory 1
The data are stored in 4-1 and 14-2, respectively (S1).

Next, the corresponding pixel numbers i (i = 0, 1, 2, ..., M-) of the respective picked-up image memories 14-1, 14-2.
The data P _{1 (i)} and P _{2 (i)} of _{1 )} are extracted (S2). Then, the difference between the extracted data P _{1 (i)} and P _{2 (i)} (| P _{1 (i)} −
P _{2 (i)} |) data DEF (i) is obtained and stored in the difference memory 15 (S3).

Next, based on the difference data DEF (i) stored in the difference memory 15, a histogram is created as shown in FIG. 3 (a) (S4). In FIG. 3 (a),
The horizontal axis represents the gradation difference, and the vertical axis represents the frequency. In the case of this example, the mold 1 itself, which is the background of the molded product 7, has a small gradation difference and a large frequency. Therefore, it is predicted that the region having a large gradation difference and a small frequency is the molded product holding region of the mold 1. Next, the threshold value TH _DEF for binarizing the difference data DEF (i) is obtained based on the created histogram (S5).

Then, the difference data DEF (i) is binarized based on the obtained threshold value TH _DEF (S6). Figure 3
(B) shows the relationship between the binarized data “1” and “0” in the histogram in this case and the threshold value TH _DEF . Thus, the difference data DEF (i) is equal to the threshold value T
If it is more than H _DEF, data "1", difference data DEF
If (i) is smaller than the threshold value TH _DEF, it is binarized as data “0”.

Then, only the pixel number of the binary data "1" is recognized (S7). In this case, the pixel number of data "0" is not recognized. Then, a table of the recognized pixel number (i) is created (S8), and the presence or absence of the molded product 7 in the mold 1 is determined based on the table. For example, the captured image data IMD immediately after mold opening stored in the latest image memory 12 and the data in the creation table are compared in a specific area, and the presence or absence of the molded product 7 is determined based on the comparison result.

Next, the operation of the configuration shown in FIG. 1 will be described.
In the injection molding apparatus, in a state where the movable mold 1 and the fixed mold 2 are clamped (not shown), resin is injected by the cylinder 4 into the cavity formed by the molds 1 and 2, Molding is performed. Then, after the resin is cooled, the mold opening in the state as shown in FIG. 1 is performed. At this time, the molded product 7 is held by the movable mold 1 and moved to a predetermined position.

The camera 8 is fixed at a position where the molded product holding surface of the movable side mold 1 at the mold opening completion position can be imaged from a predetermined position and direction, and when the mold opening is completed, the camera 8 is fixed. The movable die 1 is imaged by 8. The analog imaged image data taken by the camera 8 at this time is converted into digital data by the A / D converter 10 and input to the control circuit 11.

The picked-up image data input to the control circuit 11 is stored in the latest image memory 12 after being subjected to a predetermined binarization process and the predetermined noise data removed, and the picked-up image memory 14 is also stored. -2 is stored.

Next, in the step of taking out the molded product, the projecting portion 5 is moved to the right in the drawing, and the projecting pin 6 provided on the movable mold 1 is pushed to the right. As a result, the molded product 7 is projected from the movable mold 1. Molded product 7
When the protrusion of is completed, the protrusion 5 is moved to the left and returned to its original position. Here, the molded product 7 is taken by the camera 8.
The movable die 1 is imaged after the is projected. The analog captured image data from the camera 8 at this time is converted into digital data by the A / D converter 10, and the control circuit 1
Input to 1. The picked-up image data input to the control circuit 11 is subjected to a predetermined binarization process, the predetermined noise data is removed, and the picked-up image memory 14-1 is stored.

Next, in the control circuit 11, the corresponding pixel number i (i) of each of the picked-up image memories 14-1 and 14-2.
= 0,1,2, ..., m-1 ) of the data P _{1 (i),} extracted P _{2 (i)} is extracted data P _{1 (i)} and P _{2 (i)} the difference between the data DEF ( i) is calculated and stored in the difference memory 15. Then, the difference data DEF stored in the difference memory 15
A histogram is created based on (i), and a threshold TH _DEF for binarizing the difference data DEF (i) is obtained based on the created histogram. Next, based on the obtained threshold value TH _DEF , the difference data DEF
(I) is binarized, and among the binarized data “1” and “0”, only the pixel number of the binarized data “1” is recognized,
A table of the recognized pixel numbers (i) is created.

Then, the captured image data IMD immediately after mold opening stored in the latest image memory 12 is compared with the data in the preparation table in a specific area, and the presence or absence of the molded product 7 is determined based on the comparison result. If it is determined that the molded product 7 does not remain in the fixed-side mold 2 and that the mold is opened satisfactorily as a result of the determination, for example, an image is taken in a condition where there is no molded product in the molded product holding area of the mold 1. Captured image memory 1 and reference data given in advance based on the captured image data
4-1 is compared with the held data, and when both data substantially match, the molded product 7 does not remain in the fixed mold 1 and the molded product 7 is projected well. It is judged and the process moves to the next mold clamping process.

On the other hand, when it is determined that the molded product 7 remains in the stationary mold 2, the next mold clamping operation in that state causes an unreasonable force to act on the mold. Since a harmful effect such as damage to the die occurs, the molding operation is stopped without shifting to the operation of comparing with the reference data.

Further, even if it is judged that the molded product 7 does not remain in the fixed side mold 2 and that the mold opening is performed satisfactorily, after the protrusion, the comparison data do not match and the mold 1 is molded. If it is determined that the product 7 remains, if the mold is clamped in that state, an unreasonable force acts on the mold and the mold is damaged, so that the molding operation is stopped. .

As described above, according to this embodiment,
The camera 1 picks up the mold 1 after opening the mold and the mold 1 after the molded product take-out process from predetermined positions and directions, and stores them in the picked-up image memories 14-2 and 14-1, respectively, The difference between the picked-up image data of the mold 1 after opening and the picked-up image data of the mold 1 after the molded product taking out step is obtained, and a histogram based on this difference is created,
Molding in the mold on the basis of any one of the two levels "1" and "0" of binary data obtained by binarizing the histogram based on a predetermined threshold value, for example "1" data. Since the presence / absence of a product is determined, it is possible to detect the presence / absence of a molded product in the mold, in addition to being able to follow changes in the external environment and suppressing the occurrence of erroneous determination even if there is a large brightness unevenness on the mold surface. Can be performed accurately and accurately without malfunction.

[0037]

As described above, according to the present invention,
In addition to being able to follow changes in the external environment, the advantage of being able to suppress the occurrence of erroneous judgments even if there is a large amount of uneven brightness on the mold surface and to detect the presence or absence of molded products in the mold accurately and accurately without malfunctions is an advantage. is there.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a mold monitoring device and an injection molding device according to the present invention.

FIG. 2 is a flowchart showing a data creation procedure for determining the presence / absence of a molded product in the mold of the control circuit according to the present invention.

FIG. 3 is a diagram for explaining a histogram creation and binarization procedure.

FIG. 4 is a diagram for explaining a conventional mold monitoring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Movable side mold 2 ... Fixed side mold 3 ... Tie bar 4 ... Cylinder 5 ... Projection part 6 ... Projection pin 7 ... Molded product 8 ... Television camera (imaging means) 10 ... A / D converter 11 ... Control circuit 12 ... Latest image memory 13 ... Program memory 14-1, 14-2 ... Captured image memory 15 ... Difference memory

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication B29C 45/84 7365-4F G01N 21/84 Z G01V 8/10 G06T 7/00

Claims (2)

[Claims] 1. A mold monitoring device for detecting the presence / absence of a molded product in a mold after molding, wherein the mold after mold opening and the mold after the molded product take-out step are predetermined. An image pickup means for picking up an image from a position and a direction; a first data holding means for holding the imaged image data of the mold after mold opening obtained by the image pickup means; and a molded product taking out step obtained by the image pickup means. Second data holding means for holding the picked-up image data of the die after passing, difference between the image data held in the first data holding means and the image data held in the second data holding means Binarization processing is performed on a histogram based on a predetermined threshold value as a reference, and data in any one of two levels of binarized data and data in a predetermined area of captured image data The ratio Die monitoring device and a judging means for judging whether the molded article. 2. A mold monitoring method for monitoring the presence / absence of a molded product in a mold after molding, wherein the mold after mold opening and the mold after the molded product take-out step are determined in advance. Images are taken from the position and direction, and the difference between the imaged image data of the mold after mold opening and the imaged image data of the mold after the molded product taking out step is obtained,
A histogram based on the difference is created, the histogram is binarized based on a predetermined threshold value, and the binarized data having two levels is used to generate the data in the mold based on the data at any level. Mold monitoring method to determine the presence of molded products.