JPH0857929A - Die monitoring apparatus and method therefor - Google Patents

Abstract

PURPOSE: To provide an apparatus and a method for monitoring a die wherein a fear of malfunction is eliminated. CONSTITUTION: A die monitoring apparatus monitors the presence of moldings 7 in a movable die 1 and defection of moldings after molding. The die monitoring apparatus comprises an optical sensor 15 for generating a position detecting signal by detecting the movable die 1 reaching a predetermined imaging position in a die moving stroke, and a camera 8 arranged to provide image pickup of the predetermined imaging position and perform image pickup in accordance with the position detecting signal to provide a pickup image data.

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 or absence of a molded product after molding in a mold mainly used for a molding machine for plastics and the like and a molding failure. It is a thing.

[0002]

2. Description of the Related Art Conventionally, a general injection molding apparatus monitors a mold, for example, Japanese Patent Publication No. 58 shown in FIG.
Those described in Japanese Patent Laid-Open No. 4616 or Japanese Patent Laid-Open No. 4-138235 are known. In FIG. 2, reference numeral 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, 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 mold 1 is configured to move along the tie bar 3 in a direction indicated by an arrow A in the figure.

The image processing system 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 is image data obtained by previously capturing an image of the movable side mold 1 which 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 side mold 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 molded by the molds 1 and 2,
Molding is performed. Then, after cooling the resin, FIG.
Mold opening is performed in a state as shown in FIG. At this time, the molded product 7 is held by the movable mold 1 and moved to a predetermined mold opening completion 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. At the same time, it is determined that there is no molding defect such as a sheet shot of the molded product 7, and the process proceeds to the next molded product takeout step.

On the other hand, when the image processing system 9 determines that the image pickup data is different from the second reference image data, whether the molded product 7 remains in the stationary mold 2 or
Depending on whether the molding is defective, if the mold is taken out and the mold is clamped the next time, the mold may be damaged due to excessive force acting on the mold, or the defective product continues. Therefore, the molding work is stopped because it may cause problems such as being produced.

When moving to the next step of taking out the molded product, the protruding portion 5 is moved rightward in the drawing and protruded from the movable side mold 1. When the protrusion of the molded product 7 is completed, the protrusion 5 is moved leftward and returned to its original position.
Here, the camera 8 images the movable mold 1 after the molded product 7 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 is
It is judged that the molded product 7 did not remain in the movable mold 1 and the molded product 7 was properly ejected, and the process proceeds to the next mold clamping step.

On the other hand, when the image processing system 9 determines that the image pickup data is different from the first reference image data, the molded product 7 remains in the movable mold 1 and remains as it is. When the next mold clamping is performed, an unreasonable force is exerted on the mold to cause damage to the mold, so that the molding operation is stopped.

[0012]

However, in such a conventional mold monitoring device, the camera 8 takes an image of the molded product holding surface of the movable mold 1 at the mold opening completion position from a predetermined position and direction. The movable side mold 1 is imaged by the camera 8 when it is fixed at a possible position and the mold opening is completed.

It is known that the mold opening completion position is not constant and varies due to mechanical error. For example, when a hydraulic actuator is used to move the movable mold 1,
There is a case where the play in the moving direction is large and the movable mold 1 does not stop at a predetermined position.

It is difficult to say that the accuracy of the obtained captured image data is good when the image is picked up at the mold opening completion positions which are not constant in this way, and it is compared with the preset first or second reference image data. Then, when determining the degree of coincidence between the two, there is a possibility that an erroneous determination may occur and a malfunction may occur.

Therefore, it is an object of the present invention to provide a mold monitoring apparatus and a method therefor, which are free from the risk of malfunction.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in the one described in claim 1, the presence or absence of a molded product in a mold after molding or defective molding is monitored. In the mold monitoring device to detect the arrival of the mold to a predetermined imaging position provided in the mold moving step,
A mold monitoring device having a position detection unit that outputs a position detection signal and an image pickup unit that is arranged so as to pick up the image pickup position in advance and picks up an image in accordance with the position detection signal to obtain picked-up image data. Is characterized by.

According to the second aspect of the present invention, in the mold monitoring method for monitoring the presence or absence of a molded product or defective molding in the molded mold, the position detecting means is provided in the mold moving step. When the arrival of the die at a predetermined image pickup position is detected and a position detection signal is output, the image pickup means receives the position detection signal and picks up the image pickup position to obtain imaged image data. It features a monitoring method.

[0018]

[Operation] According to this means, when the position detecting means detects the arrival of the die at a predetermined image pickup position provided in the die moving step, a position detection signal is output.

In response to the position detection signal, the image pickup means arranged in advance to pick up the image pickup position picks up the mold at the image pickup position to obtain picked-up image data.

Therefore, the die is always imaged at the image pickup position, and stable image pickup image data can be obtained without causing variations as in the conventional case.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. It should be noted that the same or equivalent parts as those of the conventional example will be described with the same reference numerals.

First, the structure will be described. In the mold monitoring apparatus for monitoring the presence or absence of molded products or defective molding in the molded mold of the injection molding machine of this embodiment, reference numeral 1 is a movable mold, and 2 is a movable mold. Fixed die, 3 tie bars, 4 cylinders, 5
Is a protruding portion, 6 is a protruding pin, 7 is a molded product, and 8 is
A television camera (hereinafter, simply referred to as a camera) as an imaging unit that is fixed to a predetermined position so as to capture the imaging position in advance, 10 is an analog / digital (hereinafter, A / D) converter, and 11 is a control circuit. , 12 is a program memory, 13 is a reference image memory, 14 is a captured image memory, 1
Reference numeral 5 is an optical sensor as a position detecting means, 16 is a reflecting mirror of the optical sensor 15, and 17 is a monitor.
The movable mold 1 is configured to move along the tie bar 3 in a direction indicated by an arrow A in the figure.

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

Further, the control circuit 11 controls the output of the reference image data and the picked-up image data to the monitor 17, the operation instruction control to the molding apparatus drive system, and the like. The control circuit 11 includes a signal processing / determination circuit 1
11 is provided.

The signal processing / judgment circuit 111 reads out desired data from the program memory 12 and the reference image memory 13 and stores the digital captured image data input from the A / D converter 10 in the captured image memory 14. Alternatively, the read processing is performed to determine whether or not the captured image data matches the basic image.

Therefore, in the signal processing / determination circuit 111, the image data from the camera 8 is compared with the preset first and second reference image data, and the degree of coincidence between the captured image data and the reference image data is determined. To be done. This determination process is performed by inputting a mold position detection signal from the optical sensor 15.

Here, the first reference image data refers to image data obtained by previously capturing an image of the movable mold 1 which 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. .

Further, the optical sensor 15 irradiates the reflecting mirror 16 with a light beam having a constant wavelength to detect the reflected light. Then, when the movable side mold 1 moves in the left-right direction in the figure along the tie bars 3 and 3, the optical path of this light beam is blocked by the movable side mold 1 at the time when it approaches the imaging position by the camera 8. Then, the mold position detection signal is output to the signal processing / determination circuit 111.

Next, the operation of the embodiment will be described.

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 molded by the molds 1 and 2,
Molding is performed. Then, after cooling the resin, FIG.
The mold moving step to the mold open state as shown in FIG.
At this time, the molded product 7 is held by the movable mold 1 and moves in the direction of the imaging position provided in a predetermined mold moving step. Then, when the optical sensor 15 detects the arrival at the image pickup position, a position detection signal is output.

Signal processing / determination circuit 1 of the control circuit 11
At 11, when the position detection signal is received, the camera 8 arranged to pick up the image pickup position in advance picks up an image of the molded product 7 held by the movable mold 1 at the image pickup position. The captured analog image data is converted into digital image data by the A / D converter 10, and the control circuit 1
It is output to 1.

The signal processing / judgment circuit 111 employs this digital image data as picked-up image data, compares this digital image data with preset second reference image data, and judges the degree of coincidence between the two. To be done.

During this time, the movable mold 1 is moved to the mold opening completion position.

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. At the same time, it is determined that there is no molding defect such as a sheet shot of the molded product 7, and the process proceeds to the next molded product takeout step.

On the other hand, when the image processing system 9 determines that the image pickup data is different from the second reference image data, whether the molded product 7 remains in the stationary mold 2 or
Depending on whether the molding is defective, if the mold is taken out and the mold is clamped the next time, the mold may be damaged due to excessive force acting on the mold, or the defective product continues. Therefore, the molding work is stopped because it may cause problems such as being produced.

When the process moves to the next molded product removing step, the protrusion 5 is moved to the right in the figure, and the protrusion 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. When the protrusion of the molded product 7 is completed, the protrusion 5 is moved leftward and returned to its original position.

Next, the process moves to the mold moving process, which is a previous stage before the process proceeds to the mold clamping process.

In this mold moving step, the movable mold 1 is moved rightward from the mold opening completion position in FIG.
Then, when the optical sensor 15 detects the arrival of the movable mold 1 at the image pickup position, a position detection signal is output.

When this position detection signal is input to the signal processing / judgment circuit 111 of the control circuit 11, the camera 8 arranged to pick up the image pickup position in advance picks up the movable side mold 1 at the image pickup position. Take an image with. The captured analog image data is converted into digital image data by the A / D converter 10 and output to the control circuit 11.

In the signal processing / judgment circuit 111, this digital image data is adopted as the picked-up image data, and this digital image data is compared with the preset first reference image data to judge the degree of coincidence between them. To be done.

As a result of the judgment, when it is considered that the picked-up image data substantially matches the first reference image data, the molded article 7 is
It is judged that the molded product 7 did not remain in the movable mold 1 and the molded product 7 was properly ejected, and the process proceeds to the next mold clamping step.

On the other hand, when the image processing system 9 determines that the image pickup data is different from the first reference image data, the molded product 7 remains in the movable mold 1 and remains as it is. When the next mold clamping is performed, an unreasonable force is exerted on the mold to cause damage to the mold, so that the molding operation is stopped.

Therefore, according to the mold monitoring apparatus and the method therefor, it is possible to obtain stable picked-up image data without causing variations in the picked-up position, and there is no fear of malfunction.

Further, in this embodiment, the signal processing / judgment circuit 111 can store or read the digital picked-up image data in the picked-up image memory 14. Therefore, the captured digital captured image data is once stored in the captured image memory 14, and when the optical sensor 15 detects the arrival of the movable mold 1 to the image capturing position, the digital image at the time of arrival is obtained. If the picked-up image data is read from the picked-up image memory 14, even if there is a gap between the detection by the optical sensor 15 and the pick-up by the camera 8, the picked-up image of the movable mold 1 at the pick-up position is obtained. It can be data. Further, if the time until the reading is made variable, it is possible to correct the timing deviation due to the die change.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and the present invention is applicable even if there is a design change or the like within the scope not departing from the gist of the present invention. include.

For example, in the above embodiment, the optical sensor 15 is used as the position detecting means, but the invention is not limited to this. For example, another optical sensor such as a laser sensor or an infrared sensor, a limit switch or the like. Any position detecting means such as an electric contact detecting means, a voltage change detecting means such as a potentiometer, an encoder and an ultrasonic sensor may be used to detect the die reaching the predetermined image pickup position.

Further, although the first and second reference image data are used in the above embodiment, the present invention is not limited to this, and the determination may be performed using only one of the reference image data. .

Furthermore, in the above-mentioned embodiment, the presence or absence of a molded product in the mold after molding or the molding defect is monitored, but only one of them may be monitored.

Further, in the above-mentioned embodiment, the light beam emitted by the optical sensor 15 is reflected by the reflecting mirror 16 and the position detection signal is output when the movable side mold 1 blocks this light beam. However, not limited to this, for example, a reflective portion is provided on the surface of the movable die 1 facing the optical sensor 15, and a position detection signal is output when the emitted light is reflected and returned. You may do it.

Further, in the above embodiment, the camera 8 and the picked-up image memory 14 are separately shown in FIG. 1, but the place where the picked-up image memory 14 is arranged is not limited to this, and the camera 8 is not limited thereto. The captured image memory 14 may be provided inside.
In addition, a dark current is previously applied to the camera 8,
The camera 8 may output the position detection signal to release the electronic shutter of the mold at the image capturing position to capture a still image and obtain the captured image data. In this case, the captured image memory 14 can be omitted.

[0052]

As described above, according to the present invention, when the position detecting means detects the arrival of the mold at the predetermined image pickup position provided in the mold moving step, the position detection signal is sent. Is output.

In response to this position detection signal, the image pickup means arranged in advance to pick up the image pickup position picks up the mold at the image pickup position to obtain picked-up image data.

For this reason, the die is always imaged at the image pickup position, stable image pickup image data can be obtained without causing variations as in the conventional case, and a die monitoring apparatus and method therefor which are not likely to malfunction. Can be provided,
It has a practically useful effect.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a mold monitoring device according to an embodiment of the present invention and illustrating a configuration of a main part.

FIG. 2 is a conceptual diagram illustrating a configuration of a conventional mold monitoring device.

[Explanation of symbols]

 1 Movable mold (one of molds) 7 Molded product 8 TV camera (imaging means) 11 Control circuit 15 Optical sensor (position detecting means)

Claims (2)

[Claims] 1. A mold monitoring apparatus for monitoring the presence or absence of a molded product in a mold after molding or defective molding, and detecting the arrival of the mold at a predetermined imaging position provided in a mold moving step. A position detection unit that outputs a position detection signal, and an image pickup unit that is arranged so as to pick up the image pickup position in advance, picks up an image in accordance with the position detection signal, and obtains picked-up image data. And mold monitoring equipment. 2. A mold monitoring method for monitoring the presence or absence of a molded product or defective molding in a mold after molding, wherein a position detecting means is provided for moving the mold to a predetermined image pickup position provided in a mold moving step. A method for monitoring a die, wherein when the arrival is detected and a position detection signal is output, the image pickup means receives an image of the image pickup position in response to the position detection signal to obtain imaged image data.