JPH0742688Y2 - Mold opening interlock circuit of injection molding machine - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlock circuit for preventing damage of a molded product takeout machine when a mold of an injection molding machine is opened.

[0002]

2. Description of the Related Art For example, in a production process of a synthetic resin injection-molded article, a molding die is opened (so-called mold opening) and an injection-molded article is taken out every time a molding cycle of an injection molding machine is completed. If this type of product is produced in relatively large quantities,
An automatic take-out machine for taking out these molded products is adopted, and the operation is started in synchronization with the opening of the mold, and the molded product is grasped and automatically taken out, and this is discharged onto, for example, a conveyor. .

These devices are installed on the upper part of the mold, and are structured so that the gripping parts move up and down and in the front-rear direction with respect to the mold by, for example, air pressure or electric power. ) And (b) show a schematic front view and a side view of an example of this type of unloader. 1 is a take-out machine, 2 is a mold of an injection molding machine, 3 is its fixed mold, 4 is a moving mold, 5
Is an injection nozzle. The unloader 1 includes an openable gripper (or grip, for gripping or releasing a molded product,
A gripping part 6 having a lower end (for example, a chuck) can be moved vertically between the ascending limit U and the descending limit L (grip) position by the respective air cylinders 7 for vertical movement, and the electric motor 8 allows the gripping part 6 to move in the front-back direction. Is configured so that it can travel between the forward limit F and the backward limit R (molded product discharge) positions.
The molds are controlled to perform a predetermined operation when the mold is opened.

[0004]

However, when the injection molding machine is in operation, for example, due to a temporary supply stop of the air pressure source of the air cylinder of the unloader 1, a piping failure, etc., the grip portion 6 causes the grip portion 6 to move to the mold 2. If the mold opening operation is performed at the timing of normal operation without noticing this, such as when it is in the state of descending upwards, in unattended operation, etc., the grip part 6 and the molded product extracting mechanism are damaged. There was a possibility to do.

The present invention has been made in view of the problems of the conventional example as described above. When the above-mentioned accident occurs, the mold opening is automatically stopped so that the extraction period or the extraction mechanism can be achieved. The purpose is to provide a means for preventing the possibility of damage such as.

[0006]

Therefore, in the present invention, between the mold opening control circuit of the injection molding machine and the driving power source thereof, the grip portion of the product unloader is located at the ascending limit position and its retracting limit position, respectively. The object is to achieve the above object by inserting an interlock circuit in which the normally open contacts that are closed at certain times are connected in parallel.

[0007]

Since the interlock circuit as described above is interposed between the power supply for operating the mold opening actuator of the movable mold and the control circuit, the molded product is automatically opened. Since the operation is prohibited, it is possible to prevent the possibility of damage due to mold opening of the unloader or the like.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment. FIG. 1 is an example of an interlock circuit according to the present invention. In the figure, 10 and 11 are relay contacts which are connected in parallel to each other and which are normally open, and 10 is closed by a limit switch (not shown) provided at the raised position of the unloader grip 6 and 11 is A limit switch (not shown) provided at the retreat limit R (release of molded product) position of the grip 6 is also used to close the circuit.

The interlock circuit 9 is a solenoid of a solenoid valve for operating a mold opening actuator such as a hydraulic cylinder in the mold opening control circuit 12 of the mold 2,
It is inserted and connected between the drive sources 13.

Therefore, when the grip portion 6 is above the mold 2 and drops onto the mold 2 due to an accident, the mold is not opened, so that the possibility of accidental damage is prevented. obtain. Further, at the retracted limit R (mold product release) position, since it is not on the mold 2, there is no problem even if the mold is opened.

[0011]

[Effects of the Invention] By inserting the interlock circuit as described above between the mold opening control circuit and its driving power source, when the grip part of the molded product take-out machine is dropped onto the mold due to an accident, it is automatically operated. Since the mold opening operation is prohibited, the possibility of damaging the unloader or the like can be prevented.

[Brief description of drawings]

FIG. 1 shows an example of an interlock circuit according to the present invention.

FIG. 2 is a schematic front view and a side view of an example of a unloader.

[Explanation of symbols]

 1 Unloader 2 Mold 6 Grip part 9 Interlock circuit 10/11 Up / reverse limit position contact U / L Up / down limit position F / R Forward / reverse limit position

Claims (1)

[Scope of utility model registration request] 1. Between the mold opening control circuit of the injection molding machine and its driving power source, in parallel, the normally open contacts that are closed when the grip portion of the product unloading machine is in the ascending limit position and its retracting limit position, respectively. A mold opening interlock circuit of the injection molding machine characterized by being connected.