JPS60232923A - Inspection of molding in injection molder - Google Patents

Abstract

PURPOSE:To arrange so that the quality of a finished product may precisely be judged by comparing with a reference value the temperature differential of a mold across a special section from a starting time for injection to a point of time when a certain time has elapsed. CONSTITUTION:An injection control device 6 outputs a molding process signal indicating a molding process per passing time such as injection start and termination to a temperature monitor 5. The monitor 5 calculates the temperature differential across a special section of molding cycle and judges the molding for qualitative acceptance through the comparison and arithmetic operation on said temperature differential with a model temperature differential across said section in a preset reference molding cycle model. Then the monitor outputs a molding evaluation signal to the injection control device 6 and a molding processor 8. When receiving a molding evaluation signal indicating ''unacceptable'', the molding processor 8 rejects the molding to a separate line which is different from a line for acceptable products.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for determining a molded product in an injection molding machine that performs molding by injecting resin into a mold.

BACKGROUND ART In general, in injection molding, a mold is filled with high temperature resin, so the temperature of the mold rises due to resin filling and then falls. Therefore, if you monitor the mold temperature rise due to resin filling, you will notice that the mold temperature rise is lower than normal when the resin is short shot, and the mold temperature rise is lower than normal when the resin is overpacked. is higher than normal.

Therefore, by detecting the rise in temperature of the mold due to resin filling, it is possible to determine the quality of the molded product.

Conventionally, the temperature of the injection molding machine mold during operation is constantly monitored and mold temperature is controlled, but the temperature control of the mold usually fluctuates by ±3 degrees Celsius from the set value. There is.

On the other hand, the temperature rise in the mold due to resin filling inside the mold was as low as about 2° C., and it was not possible to clearly distinguish the temperature rise in the metal mold due to resin filling. For this reason, it has not been possible to determine the quality of the molded product by simply monitoring the mold temperature using the method described above.

Purpose of the Invention Therefore, the present invention improves the disadvantages of the conventional mold temperature monitoring method as described above, monitors the molding status of a product by injection molding, and accurately determines the quality of the product.
The purpose of this invention is to provide a method for determining molded products for injection molding machines.

Structure of the Invention The molded product determination method for an injection molding machine of the present invention includes, for example, measuring the metal temperature at the injection start point and at a specific interval (at the end of resin injection) from the start point until a predetermined time has elapsed. The feature is that the molded product is determined by comparing the temperature difference in this specific section with a preset standard value.

Example DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to illustrated embodiments.

FIG. 1 shows a block diagram of an injection molding machine for carrying out the method of the present invention. The injection molding machine is equipped with a fixed mold 2 and a movable metal 5, and a temperature detection sensor 1 is installed in the fixed regular meeting fIi2. The output of the temperature detection sensor 1 is connected to a temperature monitoring device 5, and the output of the temperature detection sensor 1 is converted into a metal temperature ζζ.

The injection device 7 that injects resin into both the molds 2 and 3 is controlled by an injection control device 6.

Here, the injection control device 6 tells the temperature monitoring device 5 to start injection,
A molding process signal indicating the molding process at each elapsed time such as the end of injection is output. In this way, the temperature monitoring device inputting the molding process signal from the injection control device 6 calculates the temperature difference in a specific section of the molding cycle, and compares it with the model temperature difference in the corresponding section in a preset standard molding cycle model. do.

This comparison calculation determines whether the molded product is suitable or not, and outputs it as a molded product determination signal to the injection control device 6 and molded product processing device 8.

If the molded product is determined to be unsuitable by the input molded product determination signal, the molded product processing device 8 uses the unsuitable molded product determination signal from the temperature monitoring device 5 to treat the molded product injection molded in that cycle differently from the normal one. Discharge to a separate line.

Function In the above-described configuration, during injection molding using the apparatus of this embodiment, the injection control device 6 controls the injection device 7 to control the mold 2.
, 5 is injected.

The signal from the temperature detection sensor 1 attached to the fixing mold 2 is converted into a mold part temperature within the temperature monitoring device 5 to obtain the temperature characteristics shown in FIG. 2.

Here, in this example, the temperature difference in a specific section from injection start point A of the injection molding cycle to process point B after time T has elapsed! , XI is compared with the temperature difference in the corresponding section of the standard molding cycle model.

In this way, if an abnormality in the temperature difference in a specific injection molding section caused by resin short shot or overpack fogging is detected, a signal is sent to the molded product processing device 8 to determine that the molded product is unsuitable for molding during that cycle. The finished products are sent to a separate line for processing.

In this example, the temperature difference was compared using a specific period from the injection start point M to the process point B after 7 hours in the injection molding cycle, but the temperature difference is not limited to this period and may vary depending on the injection molding food. You can reset the settings.

Effects of the Invention The first embodiment of the molded product determination method for an injection molding machine according to the present invention is as described above, and it becomes possible to monitor the molding status of a product by injection molding and accurately determine the quality of the product.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an injection molding apparatus showing an embodiment of the present invention;
FIG. 2 is a temperature characteristic diagram of the mold. 1. Temperature detection sensor, 2. Fixed! Mold, 3. Movable mold, 4. Molded product, 5. Temperature monitoring device, 6. Injection control device, 7. Injection device, 8. Molded product processing device.

Claims (1)

[Claims] In an injection molding machine having a mold temperature monitoring device, the mold temperature difference between the injection start point of an injection molding cycle and a specific section from the start time/point is detected, and the temperature Compare the difference with a preset standard value to judge the molded product/I:
A molded product determination method for an injection molding machine, characterized in that: