JPH0732026Y2 - Control device for mold clamping cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for controlling a hydraulic pressure supplied to a mold clamping cylinder in a mold clamping device of an injection molding machine.

(Prior Art) Conventionally, a molding material that is heated and fluidized in a heating cylinder is injected into a mold by high pressure, cooled and solidified or hardened therein, and then the mold is opened to take out a molded product. In the injection molding machine, the mold clamping device and the injection device are installed on the machine base. Then, by the mold clamping device, a high-speed mold closing process of bringing the movable mold into contact with the fixed mold, a high-pressure mold clamping process of clamping the mold against the high pressure of the molding material at the time of injection, and a mold opening under high pressure. The high pressure mold opening process and the high speed mold opening process for opening the mold at high speed are performed.

FIG. 2 shows a hydraulic circuit diagram in the above-described conventional mold clamping cylinder control device.

In the figure, reference numeral 1 is a mold clamping cylinder arranged so that pressure oil can be supplied to the oil chambers 3 and 4 on both sides of the piston 2, and the piston 2 is moved in the direction of arrow A by supplying and discharging hydraulic pressure. The mold is opened and moved in the direction of arrow B to close the mold. Therefore, the rod 5 extending from the piston 2 is connected to the movable platen that holds the movable mold.

6 is a variable displacement hydraulic pump that supplies oil, and 7 is a filter that is located between the hydraulic pump and the oil tank 8 to filter the oil.

Reference numeral 9 is an electromagnetic switching valve for selectively supplying pressure oil from the hydraulic pump 6 to the oil chambers 3 and 4 of the mold clamping cylinder 1,
The pressure oil is supplied into the oil chamber 3 by moving the valve to the I position, the pressure oil is supplied into the oil chamber 4 by moving the valve to the II position, and the mold clamping cylinder is set to the neutral state by moving the valve to the N position. To do. Reference numeral 10 is a check valve for preventing the pressure oil in the oil chamber 3 from flowing back due to the pressure of the molding material or the like.

Reference numeral 11 is an oil passage for supplying pressure oil from the hydraulic pump 6 to another actuator.

The hydraulic pump 6 includes a pump body 16 rotated by a motor 15, a pressure sensor 17 for detecting the pressure of oil discharged from the pump body 16, a comparator 18 for comparing the oil pressure and flow rate with a set value, and a pressure. And valves 19 and 19 'for maintaining the flow rate at a set value, an actuator 20 for operating a mechanism for varying the capacity of the hydraulic pump 6, a sensor 21 for detecting the state of the mechanism, and a relief valve 22. Built-in. The pressure setting and the flow rate setting are performed by the control device 25 connected to the comparator 18.

In the mold clamping cylinder control device having the above-described configuration, the electromagnetic switching valve 9 is switched, the flow rate and pressure of the hydraulic pump 6 having the pressure sensor 17 incorporated therein are controlled, and the mold clamping cylinder 1 is driven.

Then, when the mold clamping cylinder 1 advances to close the mold at a high speed and the mold is closed, the comparator 18 of the hydraulic pump 6 continues.
A control signal from the control device 25 is input to the mold clamping force setting signal for high-pressure mold clamping. Pressure control is performed so that the pressure detected by the pressure sensor 17 becomes equal to the set value, and high pressure oil is supplied to the oil chamber 3 of the mold clamping cylinder 1.

Further, in order to confirm the pressurization of oil in the process of high-pressure die clamping, a pressurization confirmation dedicated pressure switch 26 is provided, and the pressure inside the oil chamber 3 is detected by the pressurization confirmation dedicated pressure switch 26 to raise the pressure. It can be determined whether or not it has been done.

(Problems to be solved by the invention) However, in the above-described conventional mold clamping cylinder control device, the pressure confirmation exclusive pressure switch 26 is provided in the mold clamping cylinder 1.
It is necessary to connect the oil chamber 3 to the oil chamber 3 and increase the cost.

Further, the mold clamping force in the mold clamping device is changed by changing the hydraulic pressure to the mold clamping cylinder 1, but once the hydraulic pressure to the mold clamping cylinder 1 is changed, the set pressure of the pressure check dedicated pressure switch is also changed. If you do not change it, you will not be able to check the boost, and the operability will be poor.

The object of the present invention is to solve the above-mentioned problems of the conventional control device for the mold clamping cylinder and to eliminate the need for disposing a pressure switch dedicated to checking the pressure rise during high-pressure mold clamping, and even when the mold clamping force is changed. It is an object of the present invention to provide a mold clamping cylinder control device that does not impair operability.

(Means for Solving the Problem) Therefore, in the mold clamping cylinder control device of the present invention, a mold clamping cylinder connected to the hydraulic pump and a hydraulic pump having a built-in pressure sensor via an electromagnetic switching valve is used. A means for setting the discharge hydraulic pressure of the hydraulic pump and a means for setting the hydraulic pressure for confirming the pressure increase during high-pressure mold clamping are provided, and both setting means are connected to the pressure sensor.

(Operation) According to the present invention, the hydraulic pump having the pressure sensor built therein as described above, the mold clamping cylinder connected to the hydraulic pump through the electromagnetic switching valve, and means for setting the discharge hydraulic pressure, Since the means for setting the hydraulic pressure for confirming the pressure increase at the time of high-pressure mold clamping and the both setting means are connected to the pressure sensor, the discharge hydraulic pressure is detected by the pressure sensor,
It is possible to confirm the pressure increase of oil when the high pressure mold is clamped.

(Embodiment) An embodiment of the present invention will be described in detail below with reference to FIG.

FIG. 1 is a hydraulic circuit diagram in the mold clamping cylinder control device of the present invention.

In the figure, reference numeral 1 is a mold clamping cylinder arranged so that pressure oil can be supplied to the oil chambers 3 and 4 on both sides of the piston 2, and the piston 2 is moved in the direction of arrow A by supplying and discharging hydraulic pressure. The mold can be opened and moved in the direction of arrow B to close the mold. Therefore, the rod 5 extending from the piston 2 is connected to a movable platen (not shown) that holds the movable mold.

Reference numeral 6 is a variable displacement hydraulic pump having a built-in pressure sensor for supplying oil, and 7 is a filter provided between the hydraulic pump and the oil tank 8 for filtering oil.

Reference numeral 9 is an electromagnetic switching valve for selectively supplying pressure oil from the hydraulic pump 6 to the oil chambers 3 and 4 of the mold clamping cylinder 1,
When the valve is in the I position, it is supplied into the oil chamber 3 to move the piston 2 to the right, and when it is in the II position, the pressure oil is supplied into the oil chamber 4 to move the piston 2 to the right. At the same time, the mold clamping cylinder is set to the N position to bring the piston 2 into a neutral state. Reference numeral 10 is a check valve for preventing the pressure oil in the oil chamber 4 from flowing backward due to the pressure of the molding material, and 11 is an oil passage for supplying the pressure oil from the hydraulic pump 6 to other actuators. .

The hydraulic pump 6 includes a pump body 16 rotated by a motor 15, a pressure sensor 17 for detecting the pressure of oil discharged from the pump body 16, a comparator 18 for comparing the oil pressure and flow rate with a set value, a pressure and flow rate. Valve 19 and 19 'for maintaining the hydraulic pressure at a set value, an actuator 20 for operating a mechanism for varying the capacity of the hydraulic pump 6, a sensor 21 for detecting the state of the mechanism, and a relief valve 22. ing. The pressure setting and the flow rate setting are performed by the control device 25 connected to the comparator 18.

In the mold clamping cylinder control device having the above-described configuration, the electromagnetic switching valve 9 is switched, the flow rate and pressure of the hydraulic pump 6 having the pressure sensor 17 incorporated therein are controlled, and the mold clamping cylinder 1 is driven.

Then, the mold clamping cylinder 1 advances to perform high-speed mold closing,
When the mold is closed, the comparator of the hydraulic pump 6 is subsequently connected.
A control device 25 inputs a mold clamping force setting signal for high-pressure mold clamping to the controller 18. Pressure control is performed so that the pressure detected by the pressure sensor 17 is equal to the set value, and high-pressure pressure oil is supplied to the oil chamber 3 of the mold clamping cylinder 1 to perform high-pressure mold clamping.

Further, the signal of the pressure sensor 17 for detecting the oil pressure of the oil discharged from the hydraulic pump 16 is sent to the comparator 18 and also to the booster confirmation comparator 30.

The comparator 30 for confirming pressure increase is for confirming the pressure increase of oil in the process of high-pressure mold clamping, and the set pressure for pressure increase confirmation set by the controller 25 and the pressure sensor 17 detect the pressure. Compare the output with the pressure and control the output
It is supposed to be sent to 25.

Therefore, the pressure sensor 17 for detecting the discharge hydraulic pressure can be used also as a sensor for confirming the pressure increase.

After confirming the pressurization in this way, the nozzle is advanced and the process proceeds to the injection step.

The present invention is not limited to the above embodiment,
Various modifications are possible based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

For example, although the injection molding machine is described in the present embodiment, the above-described configuration may be adopted in a die casting machine, a rubber molding machine, or a control device of a mold clamping cylinder of an IC sealing device (transfer machine). .

(Effect of the Invention) As described above, according to the present invention, the hydraulic pump having the pressure sensor built therein, the mold clamping cylinder connected to the hydraulic pump through the electromagnetic switching valve, and the discharge hydraulic pressure are set. Means, the means for setting the hydraulic pressure for confirming the pressure increase at the time of high-pressure mold clamping, and the both setting means are connected to the pressure sensor, so that the pressure sensor detects the pressure at the time of high-speed mold closing. At the same time, it becomes possible to confirm the pressure increase of the oil when the high pressure mold is clamped.

Therefore, it is not necessary to dispose a pressure switch exclusively for checking the pressure rise, so that the cost can be reduced.

Further, when the mold clamping force is changed, it is not necessary to change the set value for confirming the pressure increase, so that the operability can be improved.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a mold clamping cylinder control device of the present invention, and FIG. 2 is a hydraulic circuit diagram of a conventional mold clamping cylinder control device. 1 ... Mold clamping cylinder, 2 ... Piston, 3,4 ... Oil chamber, 5 ... Rod, 6 ... Hydraulic pump, 9 ... Electromagnetic switching valve, 10 ... Check valve, 15 ... Motor, 16 ... Pump body, 17 ... Pressure sensor , 1
8,30 ... Setting device, 25 ... Control device.

Claims (1)

[Scope of utility model registration request] 1. A hydraulic pump having a built-in pressure sensor, (b) a mold clamping cylinder connected to the hydraulic pump via an electromagnetic switching valve, and (c) for setting a discharge hydraulic pressure of the hydraulic pump. And (d) means for setting a hydraulic pressure for confirming a pressure increase during high-pressure mold clamping, and (e) both setting means are connected to the pressure sensor.