JPH0242372Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mold clamping device for an injection molding machine, a die casting machine, etc. (hereinafter referred to as a molding machine).

For safety, the mold clamping device of a molding machine is provided with a safety door on the operation side and/or the non-operation side, and the mold clamping operation is not performed when the safety door is open. A conventional example will be described with reference to FIG. Fixed die plate 1 to which a fixed mold (not shown) is fixed
1 is attached to a frame 12, and a movable die plate 13 to which a movable mold (not shown) is fixed opposite to the fixed die plate 11 is attached to a tie bar 14.
The mold clamping cylinder 15 moves forward and backward to perform the mold clamping operation. A safety door 16 is provided on the operation side of the molding machine and is slid by a cylinder (not shown).
Dogs 17 and 18 are attached to the top and bottom of 6, respectively. A limit switch 19 is provided opposite the dog 17, and the limit switch 19 controls an electromagnetic switching valve (not shown) that supplies and discharges pressure oil to the mold clamping cylinder 15. The directional switching valve 20 is arranged in series with the electromagnetic switching valve. Therefore, when the safety door 16 is opened, the limit switch 19 sets the solenoid switching valve to a position where it does not supply pressure oil to the mold clamping cylinder 15, and at the same time, the mechanical directional switching valve 20 also operates to switch the pressure oil source from the electromagnetic switching valve. This is a double interlock that blocks the oil path leading to the valve.

Although such a mechanism is equipped with a safety mechanism, there are many cases in which a mold loading/unloading mechanism is installed on the non-operating side of a molding machine these days. It was impossible to install a safety gate because it would cause problems with the operation of the entrance mechanism, which would pose a safety problem and be dangerous.

The present invention eliminates such drawbacks, and its purpose is to provide a mold clamping device for a molding machine that takes safety measures by providing a non-contact type object detector in a place where a safety door cannot be installed.

The present invention will be explained below with reference to FIG. 2 showing one embodiment. Note that the same members as those in FIG. 1, which is a conventional example, are given the same reference numerals, detailed explanations are omitted, and only different parts will be explained. The figure shows an example in which the mold loading/unloading mechanism 41 is installed on the non-operating side of the molding machine. The piston rod 31A of the cylinder 31 fixed to the frame 12 is not shown, but the safety door 1
6, the safety door 16 can be slid. As shown in FIG. 3, the cylinder 31 is connected to one side of an electromagnetic switching valve 32, and the other side of the electromagnetic switching valve 32 is connected to an air pressure source or a pressure oil source 33, the atmosphere, or a tank (not shown). This electromagnetic switching valve 32 is connected to, for example, an optical transmitter 35 and a mold clamping cylinder 1 attached to the fixed die plate 11 via a piece 34.
5 is connected to a non-contact object detector consisting of a receiver 37 attached to the optical transmitter 35 via a piece 36, so that when a person or object crosses the light beam emitted from the optical transmitter 35, the receiver 37 detects this object. is detected and a detection signal is sent to the electromagnetic switching valve 32 and an electromagnetic switching valve (not shown) that supplies and discharges pressure oil to the mold clamping cylinder 15.
As a result, the electromagnetic switching valve 32 is switched from the illustrated position to send pressurized oil or compressed air to the piston side of the cylinder 31, so the piston rod 31A moves forward and the safety door 16 opens. When the safety door 16 is opened, the mold clamping cylinder 15 is prevented from performing the mold clamping operation as described in the conventional example. At the same time, the electromagnetic switching valve (not shown) that supplies and discharges pressure oil to the mold clamping cylinder 15 in response to the detection signal of the receiver 37 is placed in a position where it does not supply pressure oil to the mold clamping cylinder 15, so this point also doubles. interlock, increasing safety.

As described above, the mold clamping device for an injection molding machine or the like according to the present invention is a mold clamping device for an injection molding machine or the like that is provided with two or more interlock mechanisms to prevent the mold clamping operation when the safety door is opened. A cylinder that opens and closes the safety door, an electromagnetic switching valve that supplies and discharges fluid to and from the cylinder, and a cylinder that is installed in a place where the safety door can be accessed and exited from the injection molding machine, etc. other than the place where the safety door is installed, and where the safety door cannot be installed. It consists of a non-contact object detector for switching the electromagnetic switching valve.

For this reason, in injection molding machines, etc., by installing a non-contact object detector in the same place even in places where it is impossible to install a safety gate, the non-contact object detector will detect when a person or object crosses the same place. Based on the signal, the electromagnetic switching valve for supplying and discharging pressure oil to the mold clamping cylinder 15 is switched to a position where no pressure oil is supplied to the mold clamping cylinder 15, and at the same time, the safety door is opened. Since the mold clamping operation is not performed while the safety door is open, the safety of the injection molding machine and the like is extremely high according to the present invention.

[Brief explanation of the drawing]

Fig. 1 is a side view of a conventional example, Figs. 2 and 3 show an embodiment of the present invention, Fig. 2 is a top view, and Fig. 3 is a top view.
The figure is a connection diagram between a cylinder and an electromagnetic switching valve. 16...Safety door, 31...Cylinder, 32...
Electromagnetic switching valve, 35... optical transmitter, 37... receiver.

Claims (1)

[Scope of Claim for Utility Model Registration] Pressure oil acting on a mold clamping cylinder that performs a mold clamping operation when the safety door provided on the operation side of the mold clamping device of an injection molding machine is closed and performs the mold clamping operation when it is opened. An injection molding machine that has two or more interlock mechanisms, such as mechanically shutting off the oil passage of the pressurized oil that acts on the mold clamping cylinder, and positioning the electromagnetic switching valve installed in the oil passage of the pressure oil that acts on the mold clamping cylinder so that it does not act on the mold clamping cylinder. In the mold clamping device, a cylinder that opens and closes the safety door, an electromagnetic switching valve that supplies and discharges fluid to and from the cylinder, and a cylinder that can enter and exit the injection molding machine at a location other than the location where the safety door is installed, and where the safety door is not installed. An injection molding machine comprising a light transmitter and a receiver provided at a possible location, and a detector that switches the electromagnetic switching valve when a person or object crosses the light beam from the light transmitter. mold clamping device.