JPS58168538A - Controlling device for nozzle touch and amount of nozzle retreat of injection molding machine - Google Patents

Abstract

PURPOSE:To eliminate the adjustment due to the dimensions of a metal mold and consequently enable the accurate control by a method wherein the inner pressure of a hydraulic cylinder, which presses against an injection nozzle on the metal mold, is detected by a pressure switch in order to confirm the nozzle touch and at the same time to issue an injection starting signal. CONSTITUTION:In the injection molding machine, which engages and disengages the metal mold 5 from the injection nozzle 2, a controlling device 11 changes- over a solenoid controlled change-over valve 7 by receiving a mold closing completion signal issues from a mold closing mechanism, resulting in urging the metal mold 5 on the injection nozzle 2 by supplying pressure oil to the hydraulic cylinder 6. The inner pressure of said hydraulic cylinder 6 or the inner pressure of a pressure oil supply pipe is detected by the pressure switch 10. When said inner pressure exceeds a set value, the switch is put into operation and detects the nozzle touch and the injection starting signal is outputted from the controlling device 11 based upon said detection signal.

Description

[Detailed Description of the Invention] This invention uses a pressure switch to confirm the touch between the injection molding machine mold and the injection nozzle, which engage and disengage each other each time an injection is performed. The present invention also relates to an injection molding machine which outputs this detection signal as an injection start signal for the next process, and which retracts the nozzle in response to a metering completion or cooling start signal and controls the amount of retraction using a timer.

Conventionally, in this type of injection molding machine, as shown in Fig. 2,
A limit switch 14 is attached to the molding machine frame 13, and a cam is attached to a cam slide 15 attached to the injection device (injection nozzle side) 1 so that its position can be adjusted. limit switch 1
4, it is troublesome to have to adjust the position of the cam 16 each time the mold is replaced, and this adjustment is delicate and requires skill, and the amount of retraction must also be adjusted each time. Problems such as having to adjust the position of the cam slide were inevitable.

This invention was made in view of the above, and
By detecting the contact between the injection nozzle and the nozzle (injection device) by the internal pressure of the nozzle (injection device) moving cylinder or the supply pipe internal pressure using a pressure switch, nozzle touch can be easily detected by simply adjusting the set pressure of the pressure switch, and This detection signal is output as an injection start signal, and the amount of retraction of the nozzle can be arbitrarily and easily changed by setting a timer.

The following will explain the embodiments shown in the drawings.

2 is an injection device, and an injection nozzle 2 is attached to the tip of the injection device 1. Reference numeral 3 denotes a fixed platen, and a mold clamping mechanism (not shown) is mounted through tie bars 4 connected to the fixed platen.

5 is a mold (fixed side) attached to the fixed platen 3. A movable cylinder 6 is disposed between the injection device l and the fixed platen 3, and the movable cylinder 6 is connected to a hydraulic power source 8 and a tank 9 via an electromagnetic switching valve 7.

10 is a pre-7 gear connected to the cylinder chamber or hydraulic pressure supply pipe on the side 3- of the movable cylinder 6 where the injection nozzle 2 and the mold 5 are brought into contact; 11 is installed in a control panel (not shown); 12 is a timer for controlling the amount of retraction of the injection nozzle 2; In the present invention, first, the control device 11 receives a mold clamping completion signal issued from the mold clamping mechanism and issues a forward command signal to the electromagnetic switching valve 7. In response to this signal, the switching valve 7 supplies pressure oil to the moving cylinder 6 so as to bring the injection nozzle 2 and the mold 5 into contact.

When the injection nozzle 2 and the mold 5 come into contact with each other, the internal pressure in the cylinder chamber and the hydraulic pressure supply line increases.

When this internal pressure reaches the preset pressure of the pressure switch 10, the switch is activated, detects contact between the injection nozzle 2 and the mold 5, and inputs the detection signal to the control device 1.

The control device 11 issues a command signal to the injection device 1 based on this detection signal, and processes such as injection, metering, cooling, mold opening, mold release, etc. are performed sequentially by known means.

Further, the control device 11 receives a measurement completion or cooling start signal during the various steps, and outputs a backward command signal to the electromagnetic switching valve 7 for a preset time of the timer 12, and according to the signal, The electromagnetic switching valve 7 is energized and pressurized oil is supplied to the moving cylinder 6 so as to move the injection nozzle 2 back from the mold 5, and at the same time, it is demagnetized and the supply is stopped when the time is up. In other words, the amount of retraction of the injection nozzle 2 is controlled by the set time of the timer 12.

As described above, according to the present invention, the injection nozzle 2 and the mold 10 are operated so as to come into contact with each other based on the mold clamping completion signal, and this contact is detected by the pressure switch 18, and the injection is performed based on this detection signal. In addition to performing the following steps, the amount of retraction of the injection nozzle can be set arbitrarily using a timer, so there is no need to make delicate adjustments to the limit switch unlike in conventional equipment, and simply adjust the set pressure of the pressure switch and set the timer. It is very easy to operate because all you need to do is to do the following, and there are almost no malfunctions due to incorrect adjustment, etc., which improves molding efficiency and enables remote control, making it possible to fully automate the molding work. It has the following effects.

=5-

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of the present invention, and FIG. 2 is a perspective view of a limit switch section of a conventional device. 2: Injection nozzle 5: Mold 6:
Moving cylinder 7: Solenoid switching valve 10: Pressure switch 12: Timer 6- Fig. 1-185-

Claims (2)

[Claims] (1) In an injection molding machine that engages and disengages the mold and injection nozzle each time an injection is made, the switching valve is controlled by a mold clamping completion signal to move the injection nozzle toward the mold. Nozzle touch control for injection molding machines that controls the cylinder, detects the cylinder's internal pressure or supply pipe internal pressure with a pressure switch, confirms nozzle touch to the mold, and outputs this detection signal as an injection start signal. Device. (2) In an injection molding machine in which the mold and injection nozzle are connected and uncoupled each time an injection is made, the electromagnetic 1-