JPH10258449A - Mold closing control method of injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold closing control method capable of achieving an increase in the cycle of an injection molding machine without requiring the high response and high speed operation of an ejector device and a mold opening and closing device. SOLUTION: A cycle is completed by the advance limit of the ejector 3a of an ejector device 3 in a process of an injection molding machine and initial mold closing operation is started before the recession of the ejector 3a is confirmed. That is, when mold closing operation is completed before the ejector 3a recedes completely, there is possibility applying damage to molds 2a, 2b or a machine and, therefore, the mold is closed regardless of the ejected state of the ejector 3a until the set value of a mold closing operation possible range position in the ejected state of the ejector 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold closing control method for an injection molding machine, and more particularly, to a mold closing control method at the start of mold closing in a mold opening / closing device of an injection molding machine.

[0002]

2. Description of the Related Art In a conventional mold closing control at the time of starting mold closing of an injection molding machine, usually, after confirming retreat of an ejector of an ejector device ejected in a previous cycle, the cycle is reset, and the next cycle is reset. A method of starting a mold closing step is employed.

[0003]

In the above-described conventional mold closing control method at the time of starting the mold closing, the cycle ends when the ejector of the ejector device is completely retracted. Therefore, as shown in FIG. The closing step is performed after the product is taken out by the ejector ejecting step and after the ejector retreating step is completed.

In order to realize a high cycle of an injection molding machine, a high response and a high speed operation of an ejector device and a mold opening / closing device are required. In the case of an electric injection molding machine, the motor for the ejector device and the motor for opening and closing the mold have to select a motor having a rating higher than that required for normal operation in order to bring out acceleration characteristics. Similarly, in the case of a hydraulic injection molding machine, in order to make the hydraulic mechanism of the ejector device and the mold opening / closing device operate with high response and high speed, for example, it is necessary for normal operation to increase the amount of oil sent to the hydraulic cylinder. Therefore, it is necessary to select a pump having a rated discharge rate larger than the above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to increase the cycle of an injection molding machine by using an ejector device and a mold opening / closing device with high response and high speed operation. Is to provide a mold closing control method at the time of mold closing start that can be achieved without the need for the following.

[0006]

The present inventor has made intensive studies to solve the above-mentioned problems, and as a result, has found that the operating conditions of each of the ejector device and the mold opening / closing device, for example, the set value of the ejector retreat speed of the ejector device and the ejector advance. By accurately grasping and setting the balance between the stroke set value and the mold closing speed set value of the mold opening / closing device and the mold closing completion stroke setting value, the mold opening / closing device is completed before the ejector retreating process is completed as shown in FIG. It has been found that the mold closing step can be performed, and that a high cycle of the injection molding machine can be realized.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mold closing control method for an injection molding machine according to the present invention is characterized in that an initial mold closing operation of the injection molding machine is started before confirmation of retreat of an ejector of an ejector device.

More specifically, the initial mold closing operation is controlled by an ejector forward stroke set value. In this control, it is preferable that the mold is closed up to the ejector forward stroke set value + α (a margin value in consideration of safety) regardless of the ejector protruding state.

More specifically, the initial mold closing operation is controlled by an ejector retreat speed set value and an ejector forward stroke set value. In this control, it is preferable that the mold closing speed set value in the initial mold closing operation is equal to or less than the ejector retreat speed set value, and a position obtained by subtracting the ejector forward stroke set value from the mold opening stroke set value is an initial mold closing completion position. .

[0010]

Embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a view showing a mold opening state of a mold opening / closing device of an injection molding machine. As shown in the figure, the point O of the mold opening / closing stroke of the mold opening / closing device is the mold 2 attached to the fixed platen 1.
In the front position A of FIG. 3A, the point O of the ejector ejecting stroke of the ejector device 3 is the product end surface of the mold 2b attached to the movable platen 4 (the ejector retreat limit position B). The distance between the front positions of the mold 2a and the mold 2b in this mold open state is the same as the mold opening completion stroke set value L, and the distance between the product end face of the mold 2b and the forward limit position C of the ejector 3a is the ejector. It is the same as the forward stroke set value E.

If the mold closing operation is completed before the ejector 3a of the ejector device 3 is completely retracted, the dies 2a and 2b and the machine may be damaged. In order to prevent damage to the machine and the molds 2a and 2b even when the mold closing operation is performed without returning the ejector 3a, a set value of the mold closing operable range position in the ejected state of the ejector 3a is provided. The cycle is ended with the advance limit of 3a, and the molding machine is operated by an algorithm that starts the mold closing operation simultaneously with the retreat operation of the ejector 3a.

The set value of the mold closing operable range position is treated as a set value similar to the set value of the mold opening and closing, and can be expressed by, for example, Equation 1.

[0013]

[Equation 1] Set value of mold-closing operable range position = Ejector forward stroke set value (E) + α (margin value in consideration of safety) That is, ejector 3a is ejected during automatic operation, and ejection holding operation is completed. At the same time, simultaneously with the retreat operation of the ejector 3a, the mold 2b attached to the movable platen 4 is closed to a preset mold closing operable range position regardless of the ejecting state of the ejector 3a.

Next, the mold closing operation according to the present invention will be described with reference to the flowchart shown in FIG.

In the process of the injection molding machine, when the ejector ejection process is completed, the mold closing process of the next cycle is started as one cycle of operation is completed, and the retreating operation of the ejector 3a and the mold closing operation of the mold opening / closing device are simultaneously started. (Step 1). In the mold closing operation, the mold is closed to a preset mold closing operable range position regardless of the retreat condition of the ejector device 3. When the mold 2b attached to the movable platen 4 has reached the mold-closing operable range position, it is determined whether or not the ejector 3a has been completely retracted (step 2). When the retreat is completed, the mold closing operation is continued (step 3), and the mold closing step is ended. If the retreat is not completed, the mold closing operation is interrupted (step 4), and the process returns to step 2.

When there is a multi-stage ejection operation, the mold ejection operation of the next cycle is similarly started with the final ejection operation as one cycle of operation completion.

The retreat operation of the ejector does not necessarily have to start simultaneously with the mold closing operation. (Embodiment 2) In this embodiment, the mold closing operation is performed by using the operating conditions of the ejector device 3 so as not to damage the machine and the molds 2a and 2b even if the mold closing operation is performed without the ejector 3a returning. Is performed in a new mold closing process, the cycle is terminated with the advance limit of the ejector 3a, and the molding machine is operated by an algorithm that starts the mold closing operation simultaneously with the retreat operation of the ejector 3a.

That is, in FIG. 1, when the ejector 3a is ejected during the automatic operation and the ejection holding operation is completed, the following initial mold closing step is operated simultaneously with the retreat operation of the ejector 3a. That is, the mold closing speed set value is set to the ejector retreat speed set value or a set value lower than that considering the safety factor, and the position obtained by subtracting the ejector forward stroke set value E from the mold opening completion stroke set value L is set to the initial mold closing speed. As the completion position, the mold 2b attached to the movable platen 4 is operated.

At this time, the front position A of the mold 2a on the fixed platen side.
Thus, the distance between the tip positions of the ejectors 3a can be controlled without falling below the distance (LE) during ejector protrusion in FIG. 1 during the retreat of the ejector 3a. After the above-described initial mold closing step, the process proceeds to a normal mold closing step.

Next, a control example of the mold closing control method will be described.

Table 1 shows an example of ejector retreat condition setting.

[0022]

[Table 1] Table 2 shows an example of a conventional mold closing condition setting. As described in the related art, the start of mold closing in the next cycle is performed after the retreat operation of the ejector is completed.

[0023]

[Table 2] Table 3 shows an example of mold closing condition setting of this embodiment. In this setting example, the initial mold closing process sets the ejector retreat speed set value as the mold closing speed set value, and sets the mold opening completion stroke set value L (300.0 m
m) to ejector forward stroke set value E (80.Omm)
Is set as the initial mold closing completion position at the same time as the retracting operation of the ejector 3a. The speed was changed when the mold closing position was 230 mm (the ejector was 70 mm).

[0024]

[Table 3] Whether or not to display the initial mold closing process in Table 3 on the screen is an operational problem, and either may be used.

[0025]

Since the present invention is configured as described above, the following effects can be obtained. That is, since the mold closing operation is performed while performing the ejector retreating operation, the cycle of the ejector retreating time can be reduced more reliably than in the conventional mold closing start method.

In order to realize a high cycle, there is no need for a motor or a hydraulic device for the ejector device and the mold opening / closing device to have high response and high speed operation, which is very economical.

Further, the safety of the machine and the mold can always be ensured without being affected by the retreat operation condition and the mold closing operation condition of the ejector device.

[Brief description of the drawings]

FIG. 1 is a view showing a mold opening state of a mold opening / closing device of an injection molding machine.

FIG. 2 is a flowchart showing a mold closing operation according to the first embodiment.

FIG. 3 is a view showing a mold closing step according to the present invention.

FIG. 4 is a view showing a conventional mold closing step.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Fixed board 2a, 2b Die 3 Ejector device 3a Ejector 4 Movable board A Fixed board side mold front position (O of mold opening / closing stroke
Point) B Ejector retreat limit position (ejector ejection stroke O point) C Ejector advance / retreat position E Ejector advance stroke set value L Mold opening completion stroke set value

Claims (5)

[Claims] 1. A mold closing control method for an injection molding machine, wherein an initial mold closing operation of the injection molding machine is started before confirmation of retreat of an ejector (3a) of an ejector device (3). 2. The mold closing control method for an injection molding machine according to claim 1, wherein said initial mold closing operation is controlled by an ejector forward stroke set value (E). 3. The injection molding according to claim 2, wherein the mold is closed up to the ejector forward stroke set value (E) + α (a margin value in consideration of safety) irrespective of the ejection state of the ejector (3a). Machine mold closing control method. 4. The mold closing control method for an injection molding machine according to claim 1, wherein said initial mold closing operation is controlled by an ejector retreat speed set value and an ejector forward stroke set value (E). 5. A mold closing speed set value in the initial mold closing operation is equal to or less than an ejector retreat speed set value, and a position obtained by subtracting an ejector forward stroke set value (E) from a mold open completion stroke set value (L) is set as an initial mold. 5. The method according to claim 4, wherein the closing position is a closing completion position.