JPH0248126Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a mold protection device for injection molding machines, etc., and detects foreign matter when it is present on the parting line of the mold, and provides alarms and other detection. It is designed to send out signals.

[Prior art]

Protective devices that detect foreign objects that fit into the parting line of a mold and send out a detection signal have been used for a long time. It looked like the one shown in the figure.

That is, the tie bar 2 is integrated with the movable template 20.
The first switch operating rod 23 is fixed to the movable mounting plate 22 that moves on the first switch operating rod 2.
The first switch 26 whose tip end of the switch 3 is fixed to the fixed floating plate 25 is opposed to the first switch 26 at a predetermined interval. In addition, a second switch operating rod 27 is fixed to the fixed-side floating plate 25, and the tip of the second switch operating rod 27 faces a second switch 29 fixed to the fixed-side mounting plate 28 at a predetermined distance. I'm letting you do it. In addition, the fixed side mounting plate 28 and the fixed side floating plate 25
A return spring 30 is interposed between them.

The above device is determined to be normal if the second switch 29 operates after the first switch 26 operates, and is determined to be abnormal if only the second switch 29 operates and the first switch 26 does not operate. and sends out a foreign object detection signal.

However, in the above device, since it is necessary to compress the return spring 30, the pressing force applied from the movable side to the fixed side becomes considerably strong.
The pressing force strongly presses the foreign matter, and in some cases, the mold may be destroyed.

Moreover, what is shown in FIG.
A first switch operating rod 33 is fixed upward to the mounting plate 32 of the first switch operating rod 33, and the tip of the first switch operating rod 33 is fixed at a predetermined interval to the first switch 36 fixed to the mounting plate 35 of the fixed side template 34. They are facing each other.
The mounting plate 35 mentioned above can move up and down on the tie bar 37 from a predetermined height until it hits the stopper 38. Further, a fixing plate 39 is provided on the top of the tie bar 37. A second switch operating rod 40 is fixed downward to the fixed plate 39, and a second switch 41 is fixed to the fixed dive plate 35 opposite the tip of the second switch operating rod 40.

In the above device as well, foreign matter is detected in the same manner as in the above case by activating/deactivating the first switch 36 and the second switch 41, but in this case, the movable template 31 As a result, it is necessary to push up the stationary mold plate 34 and its mounting plate 35, so if there is a foreign object on the parting line, the pressing force applied to the foreign object will be excessive and the mold will be damaged, as in the case described above. It may be destroyed.

[Problem that the invention attempts to solve]

As mentioned above, the conventional mold protection device uses a first switch to detect whether both mold plates are closed, and a second switch to detect whether the mold clamping operation is in progress.
This is detected by a switch, but in order to detect whether the mold clamping operation is in progress, the fixed side floating plate 25 is used in the case of Fig. 4, and the fixed side mounting plate 35 is used in the case of Fig. 5. Detection is based on whether each object has moved beyond a certain level. Therefore, in the former case, the return spring 3 is attached to the fixed side floating plate 25.
In the latter case, the fixed side mounting plate 35 and the fixed side mold plate 34 are returned to their original positions by their own weight.

However, if such a return means is adopted, a large pressing force is required as described above, which causes the problem of breaking the mold.

Therefore, the purpose of this invention is to protect the mold without increasing the pressing force for mold clamping.

[Means for solving the problem] In order to solve the above problem, this invention arranges a movable side template and a fixed side template facing each other, and places a required distance behind the fixed side template, In a mold protection device installed in an injection molding apparatus that is provided with a fixed side member that comes into contact with the fixed side member during mold clamping, a contact detection device that detects contact between a movable side mold plate and a fixed side mold plate, and a fixed side mold plate. The contact detection device consists of a retraction detection device that detects the retraction of the template, and a discrimination device that determines whether the tightness of both templates is complete or incomplete. The above-mentioned retreat detection device is constructed by attaching an operating rod to the mold plate that activates the first switch when both mold plates come into contact with each other. and an operating rod that operates the second switch when the stationary mold plate retreats.
It has an electric element operated by a switch, and the electric element constitutes a discrimination circuit, and it is determined that the switch is fully tightened when both switches are on, and incompletely tightened when the first switch is off and the second switch is on. That is.

[Effect]

In normal molding conditions, when the movable mold plate moves toward the stationary mold plate and both mold plates come into contact, the first switch of the contact detection device is operated by the operating rod opposite the switch, and is turned on. becomes. When the stationary mold plate is further pushed backward, the second switch of the backward detection device is operated by the operating rod opposite to the second switch and turned on. In this case, the determining circuit of the determining device determines that both mold plates are completely tightened.

However, if the second switch of the reversing detection device is activated even though the first switch of the contact detection device is inactive, the determination circuit of the determination device determines that the tightening is incomplete and a required signal is sent.

〔Example〕

The injection mold shown in FIG. 1 is a so-called three-plate type.

The movable side consists of a movable side mounting plate 1 and a movable side template plate 2. The fixed side consists of a fixed side mounting plate 3, a runner stripper plate 4, and a fixed side template 5. The runner stripper plate 4 and the fixed side mold plate 5 are slidable on guide pins 6 provided on the mounting plate 3, and in the state before mold clamping, the runner stripper plate 4 is attached to the mounting plate. The runner stripper plate 4 and the stationary mold plate 5 are also spaced apart from each other by a required distance.

In the above injection mold, the first limit switch 7 is attached to the movable side die plate 2, and the operating rod 8 with an adjustment screw is attached to the stationary side die plate 5 opposite to this, so that both the die plates 2, The limit switch 7 is adjusted so that it comes into contact with the operating rod 8 when the limit switch 5 comes into contact with the operating rod 8.

Further, a second limit switch 9 is attached to the stationary side mold plate 5, and an operating rod 10 with an adjustment screw is attached to the runner stripper plate 4 opposite to this.

A spring 11 for gate cutting is inserted into the guide pin 6 between the runner stripper plate 4 and the stationary template 5.

Next, the operation of the above device will be explained.

Now, move the movable side from the state shown in Figure 1,
When the movable mold plate 2 and the fixed mold plate 5 come into contact, the operating rod 8 contacts the first limit switch 7 and operates it. Further, when the movable mold plate 2 pushes the fixed mold plate 5 from this state, the operating rod 10 contacts the second limit switch 9 and operates it.

However, if a foreign object 12 exists between both templates 2 and 5 as shown in FIG. 2nd limit switch 9
only works.

Next, Figure 3 shows the circuit of the discriminator, and shows the rectification and
A DC circuit is formed through the smoothing circuit 13, and the B contact ^R2 of the second relay and the contact ^L1 of the first limit switch ⁷ are connected in series to the winding R1 of the first relay, and the B contact R2 and the contact L1 of the first limit switch ⁷ are connected in series. Self-holding contact ^R1 is connected in parallel. Further, the contact L 2 of the second limit switch ⁹ is connected in series to the winding R ² of the second relay. Furthermore, the a contact r ¹ of the first relay and the b contact of the second relay
The contact ^R2 is connected in series to the winding ^R3 of the third relay, the A contact ^R3 of the third relay is connected in series to the winding B of the buzzer, and the other A contact ^R3 is connected to the control circuit 14. An abnormality detection signal is sent out.

The second limit switch 9 may be attached to the movable attachment plate 1, and the operating rod 10 thereof may be attached to the fixed attachment plate 3, as shown by the dashed line in FIG.

The embodiment described above is a so-called three-plate type in which the fixed side is divided into three parts: the mounting plate 3, the runner stripper plate 4, and the fixed side template 5. In the case of the so-called standard type, which consists of a mounting plate, the protection device of this invention can be used as described above by attaching the fixed side mold plate so that it can slide freely on the mounting plate and making contact with the fixed side mold plate when clamping the mold. It can be applied in the same way as in the case of

In the ``utility model registration claims'' of this invention, the term ``fixed side member'' includes not only the runner stripper plate 4 described above, but also the mounting plate of the standard type described above.

[Effect of idea]

As mentioned above, in an injection molding machine that has a fixed side member that is placed at a required distance behind the fixed side mold plate and comes into contact with the fixed side member during mold clamping, the device is fixed between the fixed side mold plate and the fixed side member. Since the side mold plate is equipped with a backward detection device, the pressing force of the fixed side mold plate is only the mold clamping force necessary to move the fixed side mold plate, so even if a foreign object is caught, the mold will not be damaged. It does not destroy the mold and has the effect of reliably detecting foreign matter if it exists.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the embodiment, Fig. 2 is a plan view of the same operating state, Fig. 3 is a circuit diagram of the discrimination device, and Fig. 4 is a plan view of the embodiment.
The figure is a plan view of a conventional example, and FIG. 5 is a front view of another conventional example. 1...Movable side mounting plate, 2...Movable side template, 3...
...Fixed side mounting plate, 4...Runner stripper plate, 5...Fixed side template, 6...Guide pin, 7
...First limit switch, 8...Operation rod, 9...
...Second limit switch, 10...Operation rod.

Claims (1)

[Scope of Claim for Utility Model Registration] Injection in which a movable mold plate and a fixed mold plate are arranged facing each other, and a fixed side member is provided behind the fixed mold plate at a required distance and comes into contact with the mold plate during mold clamping. The mold protection device installed in the molding equipment includes a contact detection device that detects contact between the movable mold plate and the fixed mold plate, a retreat detection device that detects the retreat of the fixed mold plate, and a tightening of both mold plates. It consists of a discriminator that determines whether the condition is complete or incomplete. The above-mentioned retraction detection device is constructed by attaching an operating rod that operates the switch, and a second switch is attached to either the stationary template or the stationary member, and the second switch is attached to the other when the stationary template moves backward. The above discriminating device is constructed by attaching an operating rod that operates two switches, and the above discriminating device is configured by attaching an operating rod that operates two switches.
It has an electric element operated by a switch, and the electric element constitutes a determination circuit, and when both switches are on, it is determined to be completely tightened, and when the first switch is off and the second switch is on, it is determined that it is incompletely tightened. A mold protection device featuring: