Molded product ejection checking device

Details Molded product ejection checking device Molded product ejection checking device

2000-12-26

2002-06-04

Heitbrink, Tim (Department: 1722)

Plastic article or earthenware shaping or treating: apparatus

Control means responsive to or actuated by means sensing or...

Means responsive to abnormal condition completely stop...

C425S139000, C425S165000

Reexamination Certificate

active

06398536

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to a device for checking that a molded product is projected (ejected) from a metal mold or a device for judging whether a molded product is normally molded or not in an injection molding machine.
In general, in an injection molding machine, melted resin is injected into a metal mold to mold molded products. In order to eject the molded product from the metal mold, an ejecting device is used. The ejecting device has an ejecting pin driven by a motor. When the molded product is ejected from the metal mold, the ejecting pin is inserted into the cavity of the metal mold to project the molded product from the metal mold to drop the molded product.
Incidentally, the molded product sometimes does not drop from the metal mold because of some cause (for example, the malfunction of the ejecting device). If a molding cycle is performed in this state, the metal mold may be broken or an over-packing may occur. In order to prevent such a malfunction, it is necessary to check that the molded product drops from the metal mold.
In order to check that the molded product drops, an image processing device is conventionally used. That is, the ejecting device is operated and then the picture of the inside of the metal mold is taken from outside with the image processing device. Then, it is checked from the obtained image whether the molded product is left in the metal mold or not, and if the molded product is left in the metal mold, the next molding cycle is stopped.
The above-mentioned checking method using the image processing device requires that the image processing device be adjusted every time the metal mold is replaced. Also, the image processing device is expensive.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a molded product ejection checking device which is capable of checking with reliability at low cost that a molded product is ejected.
It is another object of the present invention to provide a molded product ejection checking device which is capable of detecting the state of injection of resin and judging whether a molded product passes a pass/fail criteria.
A molded product ejection checking device according to the present invention is combined with an ejecting device for ejecting a molded product molded in an injection molding machine. The ejecting device is provided with an ejecting pin driven by a motor which is controlled by a servo controller. A torque of the motor is obtained from a torque command from the servo controller.
According to the preferred embodiment, the molded product ejection checking device includes a sampling device for sampling a torque waveform of the ejecting device to obtain a detected waveform when a molded product is ejected. Also, the molded product ejection checking device includes a memory device for memorizing the torque waveform of the ejecting device when the molded product is normally ejected as a normal waveform. Further, the molded product ejection checking device includes a controlling device for judging if the molded product is normally ejected or not by the results of comparison obtained by comparing the normal wave form with the detected waveform.


REFERENCES:
patent: 4368018 (1983-01-01), Rees et al.

Affiliated with

Also associated with

Rating

Molded product ejection checking device does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Molded product ejection checking device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Molded product ejection checking device will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2902765