JPH06182773A - Injection mold - Google Patents

Abstract

PURPOSE:To provide a small injection mold for use with an air blow device is attached and to prevent scattering of a molded article during air blowing. CONSTITUTION:A movable mold Q is provided with an ejector plate 16 which is driven at the time of mold opening and an ejector pin 17 piercing through the movable mold and projecting from it so as to push out a molded article W is fixed to the ejector plate 16, while an air passage 17a having the opposite ends closed is provided in the axial direction in the central part of the ejector pin 17. The fore end part 17d of the ejector pin piercing through the movable mold Q and projecting therefrom communicates with the air passage 17a. Besides, an air jetting port 17e for jetting air to the molded article W in a state of being pushed out by the ejector pin 17 is provided, while an air intake port 17c communicating with the air passage 17a is provided in the middle lateral side part of the ejector pin 17, and the air intake port 17c is located at a position where it communicates with an air supply passage 13b provided in the movable mold Q, only when the ejector pin 17 is in the state of projecting 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 device of a type in which a molded product is ejected 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 arranged outside the die device, the molding die device including the air blowing means becomes large in size, and the injected air spreads over a wide area and is blown away. The molded products are scattered and some of them fall into the molded product collection space as intended, but some 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 is equipped with 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 ejector pin is provided with an air passage whose both ends are closed along the axial direction at the center of the ejector pin. The end has an air injection port that communicates with the air passage and injects air to the molded product that is in a state of being ejected by the ejector pin. The middle side surface of the ejector pin communicates with the air passage. An air inlet is provided, and the air inlet is provided on the movable mold only when the ejector pin projects from the movable mold when the mold is open. In a position which communicates with the supply passage.

[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 is a movable side mold mounting plate 1 fixed to a cylinder rod (not shown) by a mounting hole 10a.
0, a spacer block 11 on its front surface (left side in FIG. 1), a receiving plate 12 on its front surface, and a movable mold plate 13 on its front surface.
Are arranged, 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 1
The ejector pin 17 fixed to the ejector plate 16 composed of 6a and 16b is the spacer block 11
It is housed in the space formed inside. Further, a return pin 18 is fixed to the ejector plate 16, and the ejector plate 16 and the movable side mold plate 13 are attached.
A compression coil spring 19 is provided centering on the return pin 18 between and, and the ejector plate 16 is biased in the backward direction.

2 and 3, the ejector plate 1 is shown.
6 shows the details of the cavity portion 13a of the ejector pin 17 fixed to 6. 2 shows the state before the protrusion, and FIG.
Indicates a protruding state.

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 passage 17a is formed in the center of the ejector pin 17 in the axial direction, and an air passage 17a having both ends closed is formed by sealing one end (left in the figure) with a bush 17b. The air passage 17a is provided with an air intake port 17c on the rear end side (right side in the figure), and an air injection port 17e that is slanted toward the upper and lower parts of the ejector pin tip 17d on the front end side that is sealed by a bush 17b.
Is provided. On the other hand, in the movable side mold plate 13, the air supply passage 13b is guided from the upper part of the movable side mold plate 13, and the air supply branch passage 13c exists at the ejector pin 17.

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 from the through hole 20, and the ejector plate 16 holding the ejector pin 17 moves forward by the pressing of the cylinder rod to eject the molded product W and at the same time ejector pin tip portion. The molded product W attached to 17d is dropped by blowing air from the air injection port 17e of the ejector pin 17 with air.

When the molded product W is dropped from the die, the ejector plate 16 is provided with only the ejector pin of the conventional solid round bar, and when the mold is opened, the molded product W is simply ejected by the conventional ejector pin. There is no problem if the molded product W falls. However, in general, the small molded product W remains attached to the ejector pin tip portion 17d protruding and does not drop. Therefore, as shown in FIG. 3, the ejector plate 16 is provided with the ejector pin 17, and the air intake port 17c is provided to the air passage 17a inside the ejector pin 17 formed when the ejector pin 17 is projected.
Air communicates with the air supply branch 13c of the third air supply passage 13b, and the air flows in, and the air is ejected from the air ejection port 17e of the ejector pin tip portion 17d. 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 retreats, the ejector pin 17 retreats, and the air intake port 17c of the through hole 17a of the ejector pin 17 communicating with the air supply branch 13c is displaced from the air supply branch 13c. Supply is cut off.

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 equally surely jetted to each of the molded products W, the blown-off molded products W fall into the molded product collecting space without being scattered.

[0017]

Other Embodiments In the above embodiment, the air intake port 1 provided in the air passage 17a of the ejector pin 17 is provided.
7c communicates with the air supply branch 13c only when the ejector plate 16 moves forward. However, when the ejector plate 16 is retracted, the ejector pin 17 is completely retracted into the movable-side mold plate 13. Therefore, only when the ejector pin 17 is projected when the mold is opened, the air intake port 17c and the air supply branch 13c. The air intake 17c through the through hole 17a
Of the air passage 17a
There is no problem if air is supplied to the.

[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 during mold clamping.

FIG. 3 is a cross-sectional view showing details of the ejector pin when the mold is opened.

[Simple explanation of symbols]

 13a Cavity 13b Air supply path 16 Ejector plate 17 Ejector pin 17a Air passage 17c Air intake 17d Ejector pin tip 17e 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 device in which ejector pins for projecting a molded product by projecting through the movable-side die in an open state are fixed, the ejector pin has an air outlet whose central portion is closed along both ends in the axial direction. The molded product is provided with a passage, and a protruding end portion of the ejector pin that projects through the movable die in a mold open state is in communication with the air passage and is ejected by the ejector pin. An air injection port for injecting air is provided on the intermediate side surface of the ejector pin, and an air intake communicating with the air passage is provided. In the mold open state the ejector pin is only in a state of protruding from the movable side mold, injection mold apparatus, characterized in that in a position communicating with the air supply passage is provided on the movable mold.