JPH06285924A - Injection molding machine - Google Patents

Abstract

PURPOSE:To miniaturize an injection molding machine having an air blowoff device and to prevent the scattering of a molded product at the time of air blowoff. CONSTITUTION:In a movable mold 13, an ejector plate 16 having an ejector pin 17 driven in a mold opening state and thrusting out a molded product fixed thereto is provided and an air jet shaft 18 operated in connection with the displacement of the ejector plate 16 is provided in the vicinity of the ejector pin 17 and an air passage is provided to the air jet shaft 18. The air jet orifice communicating with the air passage and injecting air to the molded product held to a state thrust out by the ejector pin 17 is provided to the protruding end part of the air jet shaft 18 and the air taking-in orifice communicating with the air passage is provided at the intermediate side surface part of the air jet shaft 18 and provided at the position communicating with the air supply passage provided to a movable mold Q in such a state that the air jet shaft 18 protrudes from the movable mold Q.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding die apparatus which employs a method of ejecting a molded product from a cavity by using an ejector pin.

[0002]

2. Description of the Related Art In a conventional injection molding die apparatus, a method of ejecting a molded product from a mold at the time of completion of molding adopts a method of ejecting the molded product from a cavity by using an ejector pin. In the case of a small molded product that is hard to drop by just pushing it down, it was blown off with air from above the die when the ejector pin was ejected.

[0003]

According to the conventional configuration,
Since the air blowing means is provided outside the die device, the molding die device including the air blowing means becomes large, and the injected air spreads over a wide area, so it is blown away. The molded products are scattered and some of them fall into the molded product collection space as intended, but some of them are separated from the ejector pins but fly outside the molded product collection space. In the worst case, the mold parting line surface (hereinafter PL
However, there is a problem in that the mold may be damaged by continuing the molding without being able to detect the adhesion of the molded product.

Therefore, an object of the present invention is to miniaturize an injection molding die apparatus having a device for blowing a molded product with air when the mold is opened, and to improve reliability of molded product recovery.

[0005]

In order to achieve the above object, the present invention comprises a fixed side mold and a movable side mold,
The movable mold has an ejector plate that is driven by the ejector rod of the molding machine when the mold is opened.The ejector plate is fixed with ejector pins that project through the movable mold and eject the molded product when the mold is open. In the injection molding die device, the movable side mold is provided with an air injection shaft that protrudes through the movable side mold in association with the displacement of the ejector plate in the mold open state in the vicinity of the ejector pin. The injection shaft is provided with an air passage whose both ends are closed along the axial direction at the center of the injection shaft. There is an air injection port that injects air into the molded product that is in communication and is ejected by the ejector pin.
An air inlet communicating with the air passage is provided on the intermediate side surface of the air injection shaft, and the air inlet is provided only when the air injection shaft protrudes from the movable mold in the mold open state.
It is in a position where it communicates with the air supply passage provided in the movable mold.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the preferred embodiments shown in the accompanying drawings.

As shown in FIG. 1, the injection mold apparatus according to the present invention is roughly divided into a fixed mold P and a movable mold Q.
Composed of and.

The fixed mold P will be described. A nozzle bush 2 having a sprue 2a formed therein is attached via a locate ring 3 to a fixed side mounting plate 1 fixed to a main body of an injection molding machine (not shown) by a mounting hole 1a. The nozzle bush 2 has a nozzle (not shown) of an injection molding machine.
Are fitted. Further, four support pins 4 are fixed to the fixed side mounting plate 1 (only one is shown). The tip of the nozzle bush 2 is supported by a runner protruding plate 5 that is in contact with the front surface of the fixed-side mounting plate 1.
The fixed-side template 6 is in contact with the front surface of the runner protruding plate 5. The runner projecting plate 5 and the fixed-side mold plate 6 are guided by the support pins 4 by the guide bushes 7a and 7b provided respectively, and the fixed-side mold plate 6 is connected to the movable-side mold Q by a limiting bolt 8 The runner ejecting plate 5 is also limited by the same limiting bolt (not shown) in accordance with the movement of the movable mold Q to limit the separation distance between the molds when they are opened.

A guide pin 9 is fixed to the front surface of the fixed mold plate 6 for aligning with the movable mold plate 13 when the mold is clamped. A cavity portion (not shown) is formed on the front surface of the fixed-side mold plate 6, and is combined with a cavity portion 13a (FIG. 2) of the movable-side mold plate 13 described later by mold clamping to form the cavity of the molded product W. To form a section. A runner portion (not shown) is provided on the back surface of the fixed-side template 6, and the runner portion extends from the back surface toward the front surface of the fixed-side template 6, and its tip has a small diameter. A gate (not shown) is formed by narrowing down. The runner portion provided on the back surface of the fixed-side mold plate 6 is fixed to the fixed-side mounting plate 1 and the tip of a runner lock pin (not shown) provided through the runner protruding plate 5 is projected. is there.

The movable die Q will be described. As shown in FIG. 1, the movable side mold Q includes a movable side mounting plate 10 fixed to a cylinder rod (not shown) by a mounting hole 10a,
The front surface (left side in FIG. 1) is provided with a spacer block 11, a front surface thereof is provided with a receiving plate 12, and a front surface thereof is provided with a movable side mold plate 13, and each is fixed by a bolt 14. The movable side mold Q is guided by the guide pin 9 of the fixed side mold P by the guide bush 15 provided on the movable side mold plate 13 and is movable back and forth with respect to the fixed side mold P. The movable die Q is provided with an ejection mechanism. The ejecting mechanism consists of two plates 16
An ejector pin 17 and an air jet shaft 18 fixed to an ejector plate 16 composed of a and 16b are housed in a space formed inside the spacer block 11. A return pin 19 is fixed to the ejector plate 16 and
A compression coil spring 20 is provided between the movable mold plate 13 and the movable mold plate 13 with the return pin 19 as the center, and the ejector plate 16 is biased in the backward direction.

2 and 3A and 3B, the ejector pin 17 fixed to the ejector plate 16 is shown.
The details of the protruding portion of the air injection shaft 18 are shown. Figure 2
Shows the state before the protrusion and FIG. 3 shows the state before the protrusion.

From the ejector plate 16 to the receiving plate 12,
The ejector pin 17 provided through the movable side mold plate 13 extends to the cavity portion 13 a of the movable side mold plate 13. An air injection shaft 18 that is provided so as to penetrate from the ejector plate 16 to the receiving plate 12 and the movable-side mold plate 13.
Has an air passage 18a formed in the center thereof in the axial direction, and one end (left in the drawing) is sealed with a bush 18b to form an air passage 18a with both ends closed. The air passage 18a has an air intake port 1 on the rear end side (right in the figure).
8c is provided, and an oblique air injection port 18d is provided toward the ejector pin tip portion 17a located below on the front end side that is sealed by the bush 18b. on the other hand,
In the movable side mold plate 13, an air supply passage 13b is guided from the upper part of the movable side mold plate 13, and an air supply branch passage 13c exists at the air injection shaft 18.

The operation of the mold apparatus having the above-described structure will be described. The movable mold Q is moved forward by a cylinder (not shown) to perform mold clamping.
Then, the PL surfaces of the fixed-side mold plate 6 and the movable-side mold plate 13 are closed, and the respective cavity portions are united to form a cavity for a molded product on the PL surface of the mold device. Next, the resin material heated and melted by the injection molding machine is injected from the nozzle,
The cavity is filled through the sprue 2a, the runner portion and the gate. The molding material in the cavity is cooled after a lapse of a predetermined time. When the mold opening is started after the cooling is completed, the space between the runner ejecting plate 5 and the fixed side mold plate 6 is first opened by the force of a spring (not shown) or the like, and the runner is attached to the runner ejecting plate 5 by the runner lock pin. Since it is attracted, it is cut at the weakest gate part. When the mold opening is further advanced, the PL surface is opened by the limiting bolt, and the molded product W can be taken out. Here, the molded product W needs to remain in the cavity portion 13 a of the movable-side mold plate 13. When the mold opening between the runner dropping part and the product dropping part becomes full, and the mold opening further progresses, the runner ejecting plate 5 is pulled, and the connecting part of the runner lock pin and the runner is forcibly separated. At this time, the runner is dropped by using the power of a runner ejecting device (not shown). After the mold opening is completed, the cylinder rod of the molding machine enters through the through hole 21, and the ejector pin 17 and the air injection shaft 18 are pressed by the cylinder rod.
The ejector plate 16 holding the nozzles advances and ejects the molded product W, and at the same time, the molded product W attached to the ejector pin tip portion 17a drops by aiming the tip portion with air from the air injection shaft 18 and falls. Let

When the molded product W is dropped from the mold, only the ejector pin 17 is provided on the ejector plate 16.
There is no problem as long as the molded product W drops by simply ejecting the molded product W with the ejector pin 17 when the mold is opened. However, in general, the small molded product W remains attached to the tip 17a of the ejector pin 17 protruding and does not drop. Therefore,
As shown in FIG. 3A, the ejector plate 16 is provided with an air ejecting shaft 18 that is fixed similarly to the ejector pin 17, and when the ejector pin 17 is ejected, the air ejecting shaft 18 is ejected at the same time, and the air ejecting shaft 18 is ejected. Passage 18a
The air intake port 18c of the
Air communicates with the air supply branch 13c of b, and air is injected from the air injection port 18d at the tip of the air injection shaft 18. This air injection is not the conventional method of blowing the molded product W projected by the ejector pin 17 indefinitely from the upper side of the mold, so that the molded product W may scatter and the above-mentioned problem may occur. Absent. Further, as the ejector plate 16 retracts, the ejector pin 17 and the air injection shaft 18 retreat, and the air intake port 18c of the air injection shaft 18 communicating with the air supply branch 13c is closed from the air supply branch 13c. Supply is cut off. The reason why the tip of the air injection shaft 18 is recessed from the PL surface when the air injection shaft 18 is retracted is to prevent the upper molded product W from dropping in the vertically arranged cavities.

Then, the mold clamping is started again, the PL surfaces of the fixed side mold plate 6 and the movable side mold plate 13 are closed, and the above operation is repeated.

As described above, since the air is jetted to each molded product W from the same directional position, the blown molded product W falls into the molded product collection space without scattering.

[0017]

Other Embodiments In the above embodiments, the air injection shaft 1
The air intake port 18c provided on the opposite side to the protruding direction of the air passage 18a of No. 8 communicates with the air supply branch 13c only when the ejector plate 16 moves forward. However, when the ejector plate 16 is retracted, the air injection shaft 18 is completely moved to the movable side mold plate 13
Since it is pulled in, the air jet shaft 18 and the movable side mold plate 1
If the fitting accuracy of the shaft and hole with 3 is good,
The air intake port 18c is provided over the entire air passage 18a without making the air intake port 18c and the air supply branch 13c communicate with each other only when the air injection shaft 18 projects when the mold is opened. There is no problem even if the air is supplied to the air passage 18a. Therefore, an air groove is always provided on the side opposite to the air injection port 18d in the circumferential direction so as to communicate with the air supply branch 13c, and an air communication hole is opened from the air groove toward the air injection port 18d. Even if it does, the purpose is achieved.

[0018]

According to the effects of the present invention, since it can be carried out by a built-in method in a general-purpose mold mechanism, it is not necessary to provide a robot or the like for blowing off a molded product, and the production facility cost can be reduced. The installation space of the entire injection molding system including the air blowing device can be reduced. In addition, the possibility of damaging the mold is greatly reduced due to the fact that the molded product is reliably dropped, the molding stop is reduced accordingly, and the molding time can be shortened. By increasing the pressure, the reliability of the molded product drop is further improved.

[Brief description of drawings]

FIG. 1 is a main cross-sectional view of an injection molding die device of the present invention.

FIG. 2 is a cross-sectional view showing details of an ejector pin and an air injection shaft during mold clamping.

3A and 3B show details of the ejector pin and the air injection shaft when the mold is opened, FIG. 3A is a sectional view, and FIG. 3B is a view of FIG.

[Simple explanation of symbols]

 13b Air supply path 16 Ejector plate 17 Ejector pin 18 Air injection shaft 18a Air passage 18c Air intake 18d Air injection port P Fixed side mold Q Movable side mold W Molded product

Claims (1)

[Claims] 1. A fixed-side mold and a movable-side mold, wherein the movable-side mold is provided with an ejector plate driven by an ejector rod of a molding machine when the mold is opened, and the ejector plate includes a mold. In an injection-molding die apparatus in which ejector pins for projecting a molded product through the movable side mold in an open state are fixed, the movable side mold is interlocked with the displacement of the ejector plate in the mold opened state. And an air injection shaft penetrating and projecting through the movable mold is provided in the vicinity of the ejector pin, and the air injection shaft is provided with an air passage whose both ends are closed along the axial direction at the center thereof. In the mold open state, the protruding end portion of the air injection shaft that protrudes through the movable side mold is connected to the air passage and is ejected to the molded product in a state of being ejected by the ejector pin. Is provided, and an air inlet communicating with the air passage is provided at an intermediate side surface portion of the air ejecting shaft. Is in a position in communication with an air supply path provided in the movable mold only when the is protruded from the movable mold.