JPH04138235A - Mold monitoring method - Google Patents

Abstract

PURPOSE:To set accurately and easily the reference image information of a mold storing device at the time of replacing a mold by storing the first and second stages as the reference image information for monitoring the mold when the second state is different from the first state. CONSTITUTION:The image information of a mold 2 molded in a molding machine before carrying out molding is stored in a storing circuit 44 as the first state through a camera 5 and an image recognition means 42. Then, molds 1 and 2 are closed, and resin is filled and molded, and further the image information of the mold 2 is stored in the storing circuit 44 as the second state in the state that the molds 1 and 2 are opened. When the second state is judged different from the first state by a comparison circuit 45, the first and second states are used as the reference image information for monitoring the mold 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mold monitoring method, and more specifically to a method for setting mold monitoring conditions in a mold monitoring device.

[Prior art] In injection molding, etc., in order to monitor whether there is any resin remaining in the mold, the system is
The mold is monitored visually.

By the way, in order to perform image monitoring of a mold, it is necessary to memorize an image of a normal mold as a reference image and compare the reference image with the inspection image. A reference image of the mold must first be obtained.

Conventionally, when replacing a mold, a test molded product was formed using the new mold, and when the molded product was still in the mold, a human being could visually check whether the molded product was normal or not. After confirming that there is nothing in the mold in a normal state, take an image of it and store it as a reference image, then take the molded product out of the mold and confirm that nothing is in the mold After confirming visually, take this image and store it as another reference image. From now on, these reference images will be used to determine the inspection image when there is a molded product in the mold and the inspection image when there is nothing in the mold. The inspection images were inspected at the time (for example, the
(Disclosed in Publication No. 58).

[Problem to be solved] Therefore, when setting reference image information every time a mold is replaced, it is necessary to ensure that a normal molded product exists in the mold in a normal state, and that the molded product is removed from the mold. When the mold was taken out, a person visually confirmed that there was nothing in the mold and that it was in a normal state, and the image was stored as a reference image, which required human intervention each time the mold was replaced. This was an obstacle to continuous and unmanned molding operations using different molds.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a mold monitoring method that enables unmanned and labor-saving setting of reference image information when replacing a mold.

[Means for Solving the Problem] In order to achieve the above object, the mold monitoring method of the present invention has the following features:
In the molding cycle, which repeats the steps of closing the mold, filling the mold with resin and performing molding, then opening the mold and ejecting the molded product, the state of the mold before ejection after the mold opening is completed, and the state of the mold before mold opening. This is a mold monitoring method that monitors the mold by image recognition of the state of the mold after completion and ejection, and the image information of the mold installed in the molding machine and before molding is stored as the first state. Then, the mold is closed, resin is filled and molded, image information of the mold is stored as a second state with the mold open, and when the second state is different from the first state. First, the first state and the second state are used as reference image information for monitoring the mold.

[Function] Before installing a new mold into the molding machine and starting molding,
Since this is a normal state in which nothing exists in the new mold, this state can be memorized as the correct first state without being visually confirmed by a human.

Next, molding is performed using this mold, and if the image information of this mold before ejecting the molded product from the mold is different from the first state, this image information is stored as the second state. However, if this second state is equal to the first state, it is assumed that an abnormality has occurred during this molding process, so the second state is not set as the reference image and the work is stopped. Ru.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail based on the flowchart in FIG. 1, the block diagram in FIG. 2, and the configuration diagram of a molding machine and a monitoring device in FIG. 3.

Fig. 3 shows how the molds are monitored in an injection molding machine, and resin is poured into the cylinder 3 with the movable mold 1 and the stationary mold 2 clamped together (not shown). is injected into the mold, and after cooling, the mold is opened. At this time, the molded product 4 must be held toward the movable mold 1. The camera 5 takes an image of the movable mold 1 at this time as an inspection image and compares it with the reference image. If the inspection image is deemed to match the reference image, the molded product 4 is moved toward the fixed mold 2. It is determined that it does not exist.

If the inspection image differs from the reference image, the molded product 4 is present in the stationary mold 2, so if the mold is clamped as is, unreasonable force will be applied to the mold, or the injection will fail after clamping. When this is done, all of the measured amount of resin cannot be injected, which creates abnormal pressure on the resin in the cavity, causing problems such as breaking the mold. Therefore, in this case, the work is stopped.

Next, the molded product held in the movable mold 1 is ejected by the ejector pin 7 fixed to the ejector plate 6. After that, the camera 5 again takes an image of the movable mold 1 as an inspection image and compares it with another reference image. If the inspection image is deemed to match the reference image, the molded product 4
It is determined that the above does not exist. If the inspection image differs from the reference image, there may be a molded product 4, etc. in the moving mold 1, and there may be excessive force acting on the mold as described above, or abnormal pressure of the injected resin. The work will be stopped as this will cause problems such as the formation of molds and the destruction of the mold.

When the inspection image matches the reference image, the movable mold 2 and the fixed mold 2 are clamped again, and the next molded product is molded in the same manner as above with monitoring.Next, the new mold is molded. The process of molding will be explained in detail.

In response to a command from the CPU 41 (shown in the second figure), a new movable side mold and a new fixed side mold are automatically installed by an automatic mold changer (not shown) in the open state of the mold (see 1 in Figure 1).
1).

Next, in response to a command from the CPU 41, the image recognition means 42 recognizes an image of the surface of the new movable mold 2 that is still attached, on which the cavity is formed, through the camera 5.
The image information is stored in the storage circuit 44 as a state gA (first state!F3) (12 This image information is, for example,
The amount of reflected light may be measured by irradiating light onto the surface where the cavity is formed. Since the value in state A is the value before molding is performed after installing a new mold, there is no case where a molded product or the like remains in the mold, and it can be considered as a correct value.

Next, when the state A is memorized, the molds 1 and 2 are closed by the mold opening/closing means 43 and the resin is injected by the injection means 3.
), and after the resin has cooled, the mold is opened (14).

Then, the image of the surface of the movable mold 2 in which the molded product is held, where the cavity is formed, is recognized in the same manner as described above, and the image information is stored in the memory circuit 44 as state B (second state g). Remember (15).

Then, in response to a command from the CPU 41, the comparator circuit 45 determines the status! f3A and condition! ! Compare the image information with B (16)
, A and B are equal including the error range, an abnormality signal is generated and the machine is stopped (17).

In this case, the operator needs to remove the cause of the abnormality and start the work again.

If A and B are not equal, state B is a state in which the molded product or the cavity of the movable mold 2 is formed, and the value of B is considered to be correct. In this way, when state A and state B are different, they are set as reference image information for mold monitoring.

Then, production continues, and the molded product is ejected by the ejecting means 7 (18). The image of the surface where the cavity is formed after the molded product has been ejected (state C) is recognized19), and the image information is compared by the comparison circuit 4520), so that C and A are calculated except for the error range. If they are not equal, the machine is stopped (21), and if A and C are equal, the mold is closed and the resin is injected (22).

Then, the mold is opened (2B), and the molding condition of the surface where the cavity is formed is determined by image recognition (24).
), the state B is compared with the state B (25). If the state is not equal to the state B, it is determined that the state is not equal to the reference value B, and the machine is stopped (26).

If the state is equal to state B, production is continued and the molded product is ejected (27). And the protruding state (state!!E
), and if E and A are not equal, stop the machine.30) If E and A are equal, it is assumed that there is no molded product left in the mold, and this is done. The molding of one product is completed.

Therefore, it is decided whether or not to continue production with this mold (31), and the cycle of mold closing, injection (22), mold opening (23), etc., is continued in the same way as above until the planned production volume is reached. . When production is completed as planned (31
) The series of production steps ends (32).

In addition, if an abnormality is recognized in the image judgment during the above process (
Nos. 17, 21, 26, and 30) are safe because the machine stops before the mold is damaged. Only at this time does the worker need to perform recovery work.

In the second manner, accurate setting of reference image information of the mold monitoring device during mold replacement can be done unmanned. Therefore, there is no need to temporarily stop the molding machine when automatically replacing the mold.
It becomes possible to automate and make the molding machine continuous.

Effect C: By the method of the present invention described above, it is possible to easily and accurately set the reference image information of the mold monitoring device when replacing the mold, and it is also possible to do it unmanned. Furthermore, since no human effort is required, it is possible to shorten the time required to set up the mold monitoring device.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the method of the present invention, with Figure 1 being a flowchart, Figure 2 being a block diagram, and Figure 3 being a front view showing how the mold is monitored. It is a diagram. 1... Movable side mold, 2... Fixed side die, 4... Molded product. that's all

Claims (1)

[Claims] In a molding cycle in which the steps of closing a mold, filling the mold with resin and performing molding, and then opening the mold and ejecting the molded product are sequentially repeated, after the mold opening is completed and before ejection. A mold monitoring method for monitoring the mold by image-recognizing the state of the mold after the mold is opened and the state of the mold after ejection after completion of mold opening, and the mold is mounted on a molding machine and before molding. Image information of the mold is stored as a first state, then the mold is closed, resin is filled and molded, and image information of the mold is stored as a second state with the mold open. and storing the first state and the second state as reference image information for monitoring the mold when the second state is different from the first state. Type monitoring method.