JP2634475B2 - Hydraulic ejector position control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydraulic ejector position control device.

(Prior Art) Conventionally, a molding material heated and fluidized in a heating cylinder is injected into a mold under high pressure, cooled and solidified or cured therein, and then the mold is opened to remove a molded product. In the injection molding machine described above, a protruding device is provided for removing a molded product from a mold.

The ejecting device includes an ejector pin, an ejector sleeve, a stripper,
Various types such as those using air pressure are provided. Among them, in the case of an ejector pin, a protruding plate is provided at the tip of an ejector rod, and an ejector pin fixed to the protruding plate faces a cavity of a mold. It is arranged in.

The ejector rod is moved by an electric motor, a hydraulic cylinder, or the like, and projects an ejector pin into the cavity to drop the molded product from the mold.

FIG. 3 is a control block diagram of a conventional hydraulic ejector position control device.

In the figure, 1 is a cylinder for a hydraulic ejector, 2 is an ejector rod fixed to the piston 1a of the cylinder 1, 3 is a potentiometer for confirming the position of the ejector rod 2, 4 is an electromagnetic proportional valve, and The supplied oil is discharged to the cylinder 1 and the oil supplied to the cylinder 1 is discharged to the tank T. The supply destination and supply amount of the oil are proportionally set by the current supplied to the solenoids 4a and 4b at both ends of the electromagnetic proportional valve 4.

Reference numeral 5 denotes a comparator for comparing a signal from the potentiometer 3 with a reference signal. Reference numeral 6 denotes an amplifier of the electromagnetic proportional valve 4, reference numeral 7 denotes a controller for controlling an ejector operation by receiving an output from the comparator 5, reference numeral 8 denotes a position setting device for setting an ejector protrusion / return position, and reference numeral 9 denotes an ejector speed setting device. is there.

In the hydraulic ejector position control device having the above configuration, when the speed set by the ejector speed setting device 9 is sent to the amplifier 6, a predetermined signal is sent to the solenoids 4a, 4
The ejector rod 2 moves at a set speed after a predetermined amount of oil is supplied to the cylinder 1 and the cylinder 1 is supplied.

The moving position of the ejector rod 2 is detected by the potentiometer 3, and the position set by the position setting device 8 and the position detected by the potentiometer 3 are compared by the comparator 5, and when they match, the electromagnetic proportional valve 4 is turned off. , Stopped.

(Problems to be Solved by the Invention) However, in the hydraulic ejector position control device having the above configuration, the electromagnetic proportional valve 4 is excited until the potentiometer 3 detects that the position of the piston 1a of the cylinder 1 has reached the set position. When the position is detected, the magnet is demagnetized to the neutral position.

However, even when the electromagnetic proportional valve 4 is in the neutral position, the piston 1a may continue to move due to inertia and cause overrun, so that the accuracy of the stop position of the piston is not improved.

Therefore, there has been a method of controlling by a closed loop, but in this method, since the control system is closed, hunting may occur and it takes time to stop.

In particular, when the speed setting is increased, the inertia force is further increased, the overrun amount is increased, and the mold and the molded product take-out machine may be damaged. Conversely, if the speed setting is reduced in order to improve the accuracy of the stop position, the molding cycle time becomes longer.

The present invention solves the problems of the above-described conventional hydraulic ejector position control device, and when the ejector rod reaches a set position, improves the accuracy of the cylinder stop position and increases the molding cycle time. It is an object of the present invention to provide a hydraulic ejector position control device that does not have any problem.

(Means for Solving the Problems) For this purpose, in a hydraulic ejector position control device of the present invention, a cylinder having a piston connected to an ejector rod, an electromagnetic proportional valve connected to the cylinder to supply oil, and an ejector Means for detecting the position of the rod, a position setting device for setting the projecting / returning position of the ejector rod, a speed setting device for setting the speed of the ejector rod, and setting values of the position setting device and the speed setting device,
Means are provided for calculating and setting the deceleration start position of the ejector rod, the deceleration speed, and the demagnetization position of the electromagnetic proportional valve.

According to the present invention, according to the present invention, a cylinder having a piston connected to an ejector rod as described above, an electromagnetic proportional valve connected to the cylinder to supply oil, and means for detecting a position of the ejector rod, Ejector rod protrusion /
A position setting device that sets the return position, a speed setting device that sets the speed of the ejector rod, and the deceleration start position of the ejector rod, deceleration speed, and demagnetization of the solenoid proportional valve are set according to the setting values of the position setting device and the speed setting device. Since there is a means for calculating and setting the position, when the ejector rod moving at a predetermined speed reaches a predetermined position, the position detecting means detects this and sends a signal to the controller. The controller receives the signal and sends a deceleration signal to the solenoid proportional valve to decelerate the ejector rod.

And when the ejector rod reaches the degaussing position,
When this is detected, the solenoid proportional valve is set to the neutral position and the ejector rod is stopped.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a control block diagram of the hydraulic ejector position control device of the present invention.

In the figure, 1 is a cylinder for a hydraulic ejector, 2 is an ejector rod fixed to the piston 1a of the cylinder 1, 3 is a potentiometer for confirming the position of the ejector rod 2, 4 is an electromagnetic proportional valve, and The supplied oil is discharged to the cylinder 1 and the oil supplied to the cylinder 1 is discharged to the tank T. The supply destination and supply amount of the oil are proportionally set by the current supplied to the solenoids 4a and 4b at both ends of the electromagnetic proportional valve 4.

Reference numeral 5 denotes a comparator for the position of the ejector rod, which compares a signal from the potentiometer 3 with a reference signal. Reference numeral 6 denotes an amplifier of the electromagnetic proportional valve 4, reference numeral 7 denotes a controller which receives an output from the comparator 5, and controls an ejector operation, reference numeral 8 denotes a position setting device for setting an ejector protrusion / return position, and reference numeral 9 denotes an ejector speed setting. .

In the hydraulic ejector position control device having the above configuration, when the speed set by the ejector speed setting device 9 is sent to the amplifier 6, a predetermined signal is sent to the solenoids 4a, 4
The ejector rod 2 moves at a set speed after a predetermined amount of oil is supplied to the cylinder 1 and the cylinder 1 is supplied.

The moving position of the ejector rod 2 is detected by the potentiometer 3, and the position set by the position setting device 8 and the position detected by the potentiometer 3 are compared by the comparator 5, and when they match, the electromagnetic proportional valve 4 is closed. ,Stop.

An ejector position 10 calculates and sets a deceleration start position, a deceleration speed, and an electromagnetic proportional valve degaussing (stop) position based on a setting of the position setting device 8 and the speed setting device 9 based on a table or a calculation formula obtained in advance. / Speed switching calculation setting device. The ejector rod 2 is calculated by the ejector position / speed switching setting device, and deceleration is started when the ejector rod 2 reaches the set position. When the electromagnetic proportional valve reaches the degaussing position, the solenoid proportional valve is demagnetized, and accurately stops at the stop position.

In the hydraulic ejector position control device having the above configuration,
Instead of setting the settings of the position setting device 8 and the speed setting device 9 to the comparator 5 and the amplifier 6 as they are, the above-described ejector position / speed switching calculation setting device 10 performs calculation and setting to perform a deceleration process and an electromagnetic proportional valve. Stop by the demagnetization step.

FIG. 2 is a control flowchart of the hydraulic ejector position control device of the present invention.

Step The moving speed of the ejector rod 2 is set by the deceleration setting device 9.

Step The stop position of the ejector rod 2 is set by the position setting device 8.

Step The values of the deceleration start position, deceleration speed, and electromagnetic proportional demagnetization position are calculated based on the speed and position set in step.

In this case, first, the speed is gradually increased with the ejector rod stop position set constant, the overrun amount from the set stop position is measured, and the relationship between speed and overrun amount is obtained. Next, the speed of the ejector rod 2 is kept constant, the stop position is changed, and the amount of overrun from each position is determined. The above is exhaustively performed, and the amount of overrun at a stop position at a certain speed is obtained. Based on the overrun amount, the deceleration start position, deceleration, and demagnetization position of the solenoid proportional valve when a predetermined speed and stop position are set can be calculated.

Step The deceleration start position obtained in step is set in the comparator 5.

Step The moving speed set in the step is set in the amplifier 6.

Step The movement of the ejector rod 2 is started at the speed set in the step.

If the position matches the position set in the step, the deceleration speed obtained in the step is set in the amplifier 6.

Step The demagnetizing position of the proportional solenoid valve 4 determined in the step is set in the comparator 5.

The ejector rod 2 operates at the deceleration speed set in steps 1 to 3, and when the position matches the set position, the electromagnetic proportional valve 4 is demagnetized. The ejector rod 2 overruns from the degaussing position and stops at the ejector rod stop position.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the gist of the present invention.
They are not excluded from the scope of the present invention.

(Effect of the Invention) As described above in detail, according to the present invention, a cylinder having a piston connected to an eject rod,
An electromagnetic proportional valve connected to the cylinder to supply oil, a means for detecting the position of the ejector rod, a position setting device for setting the projecting / returning position of the ejector rod, and a speed setting device for setting the speed of the ejector rod And means for calculating and setting the deceleration start position of the ejector rod, deceleration and the demagnetization position of the solenoid proportional valve based on the set values of the position setting device and the speed setting device. When the ejector rod reaches the set position,
The position detecting means detects this and sends a signal to the controller. The controller receives the signal and sends a deceleration signal to the electromagnetic proportional valve to decelerate the ejector rod.

And when the ejector rod reaches the degaussing position,
When that is detected, the solenoid proportional valve is placed in the neutral position and the ejector rod can be stopped after overrunning the ejector rod by a predetermined amount.

Therefore, the stopping accuracy of the ejector rod can be improved.

Further, since the control system is open, only the output system is controlled, and the ejector rod can be quickly stopped.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a hydraulic ejector position control device of the present invention, FIG. 2 is a control flowchart of a hydraulic ejector position control device of the present invention, and FIG. 3 is a control block diagram of a conventional hydraulic ejector position control device. . 1 ... cylinder, 2 ... ejector rod, 3 ... potentiometer, 4 ... electromagnetic proportional valve, 5 ... comparator, 6 ...
... Amplifier, 7 ... Controller, 8 ... Position setting device, 9
…… Speed setting device, 10… Position / speed switching calculation setting device.

Claims (1)

(57) [Claims] (A) a cylinder having a piston connected to an ejector rod; (b) an electromagnetic proportional valve connected to the cylinder to supply oil; and (c) means for detecting a position of the ejector rod. (D) a position setting device for setting the projecting / return position of the ejector rod; (e) a speed setting device for setting the speed of the ejector rod; and (f) a setting value of the position setting device and the speed setting device. A hydraulic ejector position control device comprising means for calculating and setting a deceleration start position of an ejector rod, a deceleration speed, and a demagnetization position of an electromagnetic proportional valve.