JP2540216Y2 - Screw movement lock device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw moving lock device for keeping a screw retreat position constant after a weighing process of an injection molding machine is completed.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open Publication No. Sho 61 discloses a method in which the retreat position of a screw after completion of a measuring step is kept at a constant position, and the stop position is used as the starting point of the injection step to keep the amount of resin measured constant.
-290023.

[0005] This method will be described with reference to FIG.
Reference numeral 1 denotes an injection cylinder having a nozzle 2 attached to the tip (left side in the figure) and a material input port 3 at the rear. A screw 4 is provided inside the cylinder so as to rotate and move forward and backward. The rear part of the screw 4 is connected to a ram 8 in a hydraulic cylinder 7 connected to the rear end of the cylinder 1, and the ram 8 is connected to a rotating shaft 9 such as a motor so as to be movable in the axial direction.

A flange 10 is fixed to the rear end of the screw 4, and a member 11 rotatably mounted on the flange 10 projects outward from a hole 12 formed in the side of the cylinder, and extends laterally on the side of the cylinder. A stopper member 14 for restricting retraction of the member 11 is movably attached to the guide rod 13 when the end is inserted into the bridged guide rod 13.

[0005] The material is measured by rotating the screw 4 while applying a back pressure as usual. The screw 4 retreats due to the pressure in the cylinder 1 generated by the rotation, the rotation of the screw 4 is stopped at the position where the member 11 has operated the detector 15, and the back pressure is reduced to complete the measurement.

After the rotation is stopped, the screw 4 is retracted by the internal pressure of the cylinder.

[0007] The stop position of the screw 4 is set by moving the position of the stopper member 14 forward and backward during injection adjustment performed at the start of injection molding.

[0008]

However, in this method, the screw stop position is forcibly set to release the pressure in the resin after the completion of the measuring process every time during the injection adjustment work performed at the start of the injection molding. In addition to the setting position in consideration of the suck-back for retreating the screw, the setting must be changed many times during the adjustment, which is troublesome and hinders the workability.

In recent years, the detection of the screw position has been automated using an optical scale or the setting of the signal transmission position has been remote-controlled to improve the operability and improve the operability. Has to be moved to a required position and a screw stop position has to be set, which cannot be handled by a conventional manual device.

An object of the present invention is to provide a screw movement lock device which eliminates the above-mentioned disadvantages, has good workability, and automatically locks the screw.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a screw moving lock device for maintaining a fixed screw retreat position after a weighing process of an injection molding machine is completed.
A mounting member that moves in synchronization with the screw advance / retreat operation, a support member fixed to a fixed portion such as a frame and facing the mounting member near the screw retreat limit, and a mating member on either one of the two members. Attached so as to maintain a slight gap between them, excited by the completion signal of the suck-back process for releasing the pressure of the measuring resin after the completion of the measuring process, the two members are brought into contact by their magnetic force, and the movement of the screw is stopped. A screw movement lock device comprising an electromagnet.

[0012]

The electromagnet is excited by an output signal from the completion position of the suck-back step, and the screw can be automatically locked by the magnetic force.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. 1 to 3. Reference numeral 20 denotes a heating barrel having a nozzle (not shown) attached to the tip (left side in the drawing), and a screw on the inner diameter surface. 21 is inserted so as to be rotatable and advance / retreat by a stroke S in the axial direction.

An injection cylinder 22 is provided at the rear end of the screw 21.
Is connected to a hydraulic ram 23 slidably mounted on the ram 23, and a rotary shaft 25 of a motor 24 is connected to the ram 23.

The injection cylinder 22 to which the heating barrel 20 is mounted is integrally assembled on an injection bracket 27 which is on a sliding plate (not shown) on a frame 26 and can be moved when necessary.

A guide bar 28 is provided on the injection bracket 27, and a mounting plate 29 on which a motor 24 that moves in synchronization with the reciprocating operation of the screw 21 is mounted on the guide bar 28.
And the screw 2 guided by the rotating shaft 25 of the motor 24.
It advances and retreats by the same length S as one stroke S.

An electromagnet 30 is fixed to the side surface of the mounting plate 29, and is excited by a completion signal of a suck-back process for releasing the resin pressure of the resin material measured in the heating barrel 20 after the completion of the measuring process. It has become so.

The frame 2 near the retreat limit of the mounting plate 29
6 has a slight gap with the electromagnet 30 fixed to the side surface of the mounting plate 29, and when the electromagnet 30 is excited, abuts on the electromagnet 30 by its magnetic force.
9, a support member 31 for securely locking the screw 21 so as not to move is provided.

Since the metering process is completed as described above, the screw 21 retreats to near the retreat limit and a suckback process completion signal is transmitted, the electromagnet 30 is excited by the output signal, Due to the magnetic force, the support member 31 and the mounting plate 29 come into contact with each other and are firmly locked.

In the above description, an example is described in which an electromagnet is provided on a mounting plate on which a motor is mounted. However, the present invention is not limited to this, and the electromagnet may be mounted on either the mounting plate or the support member. The member is not limited to the mounting plate as long as the member moves in synchronization with the screw advance / retreat operation. For example, a member 40 for attaching the electromagnet 30 to the screw 21 as shown in FIG. The mating support member is not only fixed to the frame 26, but also a member to which the screw 21 relatively moves by the distance S, for example, the injection bracket 27.
It may be attached to.

[0021]

According to the present invention, the disadvantage that the operation of adjusting the stop at the screw retreat limit by variously setting the position of the stopper in the injection molding, which has been conventionally performed, is troublesome and the workability is poor is eliminated. The backward limit stop position of the screw can be easily set, and the screw is automatically locked by the completion signal of the suck-back process, so that automation and remote operability are facilitated unlike the conventional manual adjustment method.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a front view of the embodiment of the present invention.

FIG. 3 is a side view of the embodiment of the present invention.

FIG. 4 is a view showing another embodiment of the present invention.

FIG. 5 is a diagram showing a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Heating barrel 21 Screw 22 Injection cylinder 23 Hydraulic ram 24 Motor 25 Rotating shaft 26 Frame 27 Injection bracket 28 Guide bar 29 Mounting plate 30 Electromagnet 31 Support member 40 Mounting member

Claims (1)

(57) [Scope of request for utility model registration] 1. A screw movement lock device for keeping a screw retreat position constant after completion of a weighing process of an injection molding machine, comprising: a mounting member that moves in synchronization with a screw advance / retreat operation;
A supporting member fixed to a fixed portion such as a frame and opposed to the mounting member near the screw retreat limit, and mounted on any one of the two members so as to maintain a small gap between the supporting member and a measuring member; An electromagnet that is excited by a completion signal of a suck-back step of releasing the pressure of the measured resin after completion, causes the two members to abut by their magnetic force, and stops the movement of the screw. .