JPH0531452B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ejector control device for an injection molding machine that facilitates the release of a product and shortens the operating cycle time.

BACKGROUND OF THE INVENTION Mechanical and hydraulic ejector devices are used in injection molding machines to eject products from molds. For example, the mechanical type is configured to use the mold opening force of the mold clamping ram to drive an ejecting rod integrated with a protruding plate disposed between the mold clamping ram and the movable platen, and the rod pushes out the product. The speed depends on the mold opening speed of the mold and cannot be controlled independently, causing problems in controlling product release. Additionally, a hydraulic ejector device extrudes the product using an ejector rod that is linked to the piston of a hydraulic cylinder built into an injection molding machine, and generally this ejector rod is driven at the same speed in the ejection direction and return direction. For example, if the ejector operation speed is made low to take out a thin product, there is a problem that the operation cycle time of the ejector device becomes longer.

Problems to be Solved by the Invention The present invention variably controls the ejection operation speed depending on the type of product to smoothly release the product from the mold, and can shorten the operation cycle time even when ejection operation is performed at low speed. An object of the present invention is to provide an ejector control device for an injection molding machine that contributes to improving the productivity of the injection molding machine.

Means for Solving the Problems The ejector control device for an injection molding machine of the present invention has the following features:
As shown in FIG. 1, a servo motor 2 for driving an ejector device 1, a position detector A for detecting the operating position of the ejector pin of the ejector device 1, a setting means B for setting at least the ejection speed of the ejector pin, and the setting means B for setting at least the ejection speed of the ejector pin. Storage means C for storing values
and a discriminating means D for discriminating the operating position of the ejector pin from the position detector A, and when the discriminating means D detects the ejection completion position, the servo motor 2
and set speed switching means E for switching the output of the driving means F for driving the ejection speed from the stored set value of the ejection speed to the maximum return operating speed.

Operation: The ejection speed setting value set by the setting means B and stored in the storage means C according to the product is supplied to the drive means F via the switching means E. The driving means F drives the ejector device 1 via the servo motor 2 so that the ejector device 1 operates at the set ejection speed. When the determining means D detects and determines that the ejecting operation is complete based on the signal from the position detector A, the output of the switching means E switches from the set ejecting speed to the maximum return operating speed, and the ejector device 1 moves in the opposite direction to the ejecting operation. is driven to return to the above-mentioned return operating speed, and quickly return to the original operating position.

Embodiment FIG. 2 shows an ejector control device for an injection molding machine according to an embodiment of the present invention. It is equipped with a servo motor 2 that drives forward and backward in the return direction (partially not shown). 3 is the servo circuit of the servo motor 2, and the pulse distributor 15 of the numerical control device (hereinafter referred to as CNC) 10 with a built-in computer.
The servo motor 2 is provided with an incremental encoder 4 as a position detector, which feeds back to the servo circuit 3 and controls the CNC 10. Reversible counter 1
6 to detect the operating position of the ejector pin of the ejector device 1.

The CNC 10 has a built-in computer (hereinafter referred to as CPU) 11 that functions as a position determination and switching means, and the CPU 11 is equipped with a counter that counts the number of times the eject is executed. 12 stores a control program for controlling the injection molding machine
ROM, 13 is a RAM used for temporary storage of data for calculations, etc.; 14 is a non-volatile memory as a storage means; (hereinafter referred to as ejection speed and return speed) and the number of times of ejection are stored.
15 is a pulse distributor connected to the servo circuit 3, as described above. 16 is a reversible counter that counts the pulses of the encoder 4 provided on the servo motor 2 and detects the operating position of the ejector device 1; 17 is a manual input device as a setting means for setting various commands and various set values; 18 is a bus.

In the above configuration, the operation of this embodiment will be explained along with the operation processing flow shown in FIG. 3.

First, the CPU 11 clears the eject execution count value C (step S1), and compares the count value C with the set eject count value CE stored in the non-volatile memory 14 (step S2). Here, if the set number of ejects CE is the value "0", that is, the eject operation of the injection molding machine is prohibited, then the count value C and the set number of times CE are both "0" and equal, so this program is immediately terminated. .

As a result of the determination in step S2 above, the count value C (=0) is usually smaller than the set number of times CE (>0), so the process moves to step S3, and the CPU 11 changes to the set ejection speed stored in the non-volatile memory 14. Three corresponding speed commands are sent to the servo circuit via the pulse distributor 15, and the servo motor 2 driven by the servo circuit 3 starts driving the ejector device 1. As a result, the ejector pin of the ejector device 1 advances at a set ejection speed depending on the product to be taken out, in other words, the operating position of the ejector device 1 changes and the product is gradually released from the mold (not shown) of the injection molding machine. do. During this ejecting operation, the reversible counter 16 that responds to the pulse output from the encoder 4 attached to the servo motor 2 constantly detects the operating position of the ejector device 1, while the CPU
11 monitors this detection operation position and determines whether or not the ejector device 1 has reached the ejector operation completion position (step S4).

The ejecting operation progresses, and when the CPU 11 determines that the ejector device 1 has reached the ejecting completion position based on the count value of the reversible counter 16, the CPU 11 determines that the product has been released from the mold and changes the ejecting speed to the set ejecting speed. , sends out a speed command according to the set return speed stored in the nonvolatile memory 14. As a result, the servo motor 2 is driven in reverse by the servo circuit 3, and the ejector pin of the ejector device 1 is moved backward at the set return speed (step S5).
During this return operation, the CPU 11 uses the reversible counter 16.
Based on the count value of , it is monitored and determined whether or not the ejector device 1 has returned to its initial operating position, that is, the operating position at the start of ejection (step S6). The return operation of the ejector device 1 proceeds quickly, since the set return speed is set to a value that makes it possible to shorten the operating cycle time of the device 1, preferably to the maximum operating speed specific to the ejector device 1. Then, when the operating position of the ejector device 1 returns to the initial position,
CPU11 is the count value C of the number of times the eject is executed.
After adding the value "1" to (step S7), the series of operations described above is executed for the set number of ejects CE, and the program ends.

Figure 4 shows the eject operation cycle time according to the above embodiment in comparison with that of the conventional example. When the maximum operating speed Vr of the ejector device 1 is set to
The required operating cycle time varies depending on the product, such as T and T'. This required operation cycle time, for example T, is significantly reduced compared to the conventional required time T'' when the ejection speed is set to the same value as the value Ve, as shown by the broken line.

Effects of the Invention As described above, according to the present invention, the ejector device ejects at a set ejection speed depending on the product and then returns at the maximum speed, so that various products can be easily removed from the mold. The mold can be released smoothly, and after the mold is released, the ejector device quickly returns to its initial operating position, thus reducing the required operating cycle time. As a result, the total operating time of the ejector device, which repeats the operating cycle consisting of ejecting and returning operations many times, can be significantly shortened regardless of the type of product, and the productivity of the injection molding machine can be improved.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing means for solving the problem, Fig. 2 is a block diagram showing an ejector control device for an injection molding machine according to an embodiment of the present invention, and Fig. 3 is a diagram showing a means for solving the problem.
The figure is a flowchart of an ejector control program executed in the device of the same embodiment, and FIG. 4 is a diagram showing the relationship between the set operating speed and the operating cycle time in the device of the same embodiment. 1... Ejector device, 2... Servo motor,
3... Servo circuit, 4... Encoder, 10...
Numerical control device, 11... Computer, 14...
Non-volatile memory, 16... Reversible counter, 17...
...Manual input device.

Claims (1)

[Claims] 1. A servo motor that drives an ejector device;
a position detector for detecting the operating position of the ejector pin of the ejector device; a setting means for setting at least the ejection speed of the ejector pin; a storage means for storing the set value; and determining the operating position of the ejector pin from the position detector. Discrimination means;
an ejector control device for an injection molding machine, comprising: set speed switching means for switching an output of a driving means for driving the servo motor from a stored ejection speed setting value to a maximum return speed when the discriminating means detects an ejection completion position; . 2. The setting means has a means for setting the number of ejects, the storage means has a storage section for storing the set number of ejects, and a counting means is provided for counting the number of times the ejector pin protrudes, and the counting means has a number of times the ejector pin has been ejected. The ejector control device for an injection molding machine according to claim 1, wherein the ejector operation is terminated when a set number of times is reached.