JPH068290A - Adapter - Google Patents

Abstract

PURPOSE:To provide an easy maching for locking an ejector pin by a method wherein in an adapter body provided with a detent surface, a hole for inserting a head part of the ejector pin, and an abutting surface abutting against an ejector plate, a detent boss is projected on the abutting surface. CONSTITUTION:An adapter 40 is provided with a circular boss 42, which is axially projected on an abutting surface 41c of an adapter body 41 against a second ejector plate 25. A D-shaped hole 41a is formed on approximately the center of the adapter body 41. A part of the hole 41a is formed into a detent surface 41b. A head part 23a of an ejector pin 23 is fitted into the hole 41a. A detent surface 23b formed on the head part 23a of the ejector pin 23 is abutted on the detent surface 41b. The boss 42 is fitted into a hole 25a of the second ejector plate 25. This detent surface 23b can be easily machined. In addition, a top end surface can be machined slantly using the detent surface 23b as a reference surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adapter, and more particularly to an adapter for mounting an ejector pin for separating a molded product from a mold at a predetermined angular position between ejector plates.

[0002]

2. Description of the Related Art An injection molding machine is used to manufacture a resin molded product such as a plastic molded product. This injection molding machine mainly includes a pair of molds on the moving side and a fixed side, a mold clamping portion for pressing the molds against each other, and a resin for injecting resin into the molds. It is composed of an injection part.

In the case of molding using this injection molding machine, first, the movable die is pressed against the fixed die by a hydraulic cylinder or the like, and the fixed die and the movable die are clamped. The resin is injected into the mold from the injection part. After that, a mold such as a fixed mold and a moving mold is opened to obtain a molded product. At this time, due to the material contraction of the molded product, the molded product bites into the moving mold. The ejector pin method is generally used to automatically separate the molded product from the mold.

The ejector pin method is a method of separating the molded product from the moving mold by operating the ejector pin to project the bottom of the molded product. In this case, a first ejector plate for ejecting the ejector pin and a second ejector plate for retracting the ejector pin are provided. The head of the ejector pin is inserted into the counterbore hole formed in the second ejector plate on the die side. This is conventionally called a spot facing type and is widely used. On the other hand, as a method of mounting the ejector pin on the ejector plate, a spacer type has been used in recent years because it is easy to process. Conventional examples of the spacer type are shown in FIGS. In the spacer type,
As shown in FIG. 5, the first and second ejector plates 5
The head 54 of the ejector pin 53 is sandwiched between the first and the second 52. Such a spacer type does not require counter boring.

Incidentally, depending on the shape of the molded product, it becomes necessary to contact the tip of the ejector pin with the inclined surface. In this case, the tip of the ejector pin also becomes an inclined surface in accordance with the inclination of the abutting surface. Such an ejector pin whose tip is inclined needs to be prevented from rotating so as not to rotate when mounted on the ejector plate. In the case of the spacer type, as shown in FIGS. 5 to 7, notches are formed in the head portion 54 of the ejector pin 53 and a part of the ejector plate 52, and the pin 55a or the block 55b is fitted into these notches. I try to stop the rotation.

[0006]

In the conventional detent method as described above, the detent pin 55a shown in FIG. 6 is used.
In order to adopt (1), it is necessary to form an arcuate notch (rotation preventing surface) in the head portion 54 of the ejector pin 53, and this processing is very difficult. On the other hand, as shown in FIG. 7, in the detent block 55b having flat side surfaces, the head 54
The reference surface for the rotation stopper is relatively easy to process.
However, when forming the groove into which the whirl-stop block 55b is inserted in the ejector plate, processing by an end mill is required, which causes a problem that processing time becomes long.

An object of the present invention is to facilitate the processing for locking the ejector pin.

[0008]

An adapter according to the present invention is an adapter for mounting an ejector pin for separating a molded product from a mold at a predetermined angular position between ejector plates, and at least one adapter is provided. An adapter main body having a rotation stop surface and a hole into which the head of the ejector pin can be inserted, and a contact surface for contacting the ejector plate; and a rotation stop boss projecting from the contact surface of the adapter body. Is equipped with.

[0009]

In the adapter according to the present invention, first, the adapter body is mounted on the head of the ejector pin. At this time, the angular position of the ejector pin with respect to the adapter body is determined by the detent surface formed in the hole of the adapter body. Next, the ejector pin is mounted between the ejector plates together with the adapter body. At this time, a hole is formed in the ejector plate, and the boss of the adapter body is inserted into this hole. This determines the angular position between the adapter body and the ejector plate.

In this way, the ejector pin is prevented from rotating. In this case, the rotation stopping surface (notch) of the ejector pin may have, for example, the conventional shape shown in FIG. 7, and the machining becomes easy. Moreover, even in the case where the inclined surface is formed at the tip of the ejector pin, it is possible to perform processing with the anti-rotation surface as the reference surface, which facilitates processing of the inclined surface at the tip of the ejector pin. Further, the ejector plate side only needs to be formed with, for example, a circular hole, which is easy to process and can be performed in a short time.

[0011]

EXAMPLE FIG. 1 is a front view of an injection molding machine. In the figure, an injection molding machine 1 includes a body frame 2, a fixed platen 3 on which a fixed mold is mounted, and a movable platen 4 on which a movable mold is mounted.
Clamping section 5 having a hopper, an injection section 8 having a hopper 6 containing pellets and a nozzle 7 for injecting resin
It is mainly composed of and.

The body frame 2 has a mold clamping part 5 and an injection part 8 mounted thereon, and a drive system 9 is accommodated below the mold clamping part 5. A fixed-side mounting plate 11 and a fixed mold 12 having a spool bush 10 at the center are fixed to the fixed platen 3. The spool bush 10 is arranged at a portion joined to the nozzle 7, and guides the molten resin into the mold 12. The movable platen 4 is arranged on the left side of the fixed platen 3 in the figure. A movable side mounting plate 20 is fixed to the movable platen 4.
A movable die 22 is attached to the movable side mounting plate 20 via a spacer block 21. A cavity 31 into which the molten resin is introduced is formed between the movable mold 22 and the fixed mold 12. Movable plate 4 and movable side mounting plate 20
A through hole is formed in the center of the ejector rod 26, and the ejector rod 26 penetrates the through hole. The first ejector plate 24 is fixed to the tip of the ejector rod 26, and the second ejector plate 25 is arranged so as to face the first ejector plate 24 at a predetermined interval. The second ejector plate 25 has a hole 25 for inserting a rotation preventing boss described later.
a is formed. Both ejector plates 24, 25
The heads 23a of the plurality of ejector pins 23 are sandwiched between the ejector pins 23, and the ejector pins 23 penetrate through the through holes formed in the second ejector plate 25 and the movable die 22. Then, the tip reaches the surface of the moving die 22.

The tip of the ejector pin 23 is a molded product 3
The ejector pin 23 is processed to have a shape of 0, and the tip of the ejector pin 23 that abuts the inclined surface is obliquely processed at the same inclination angle as the inclination. The ejector pin 23 whose tip is obliquely processed needs a rotation stopper so as not to rotate when it is sandwiched between the pair of ejector plates 24 and 25.

In order to perform this rotation stop, FIG. 2 and FIG.
An adapter 40 as shown in is used. The head portion 23a of the ejector pin 23 whose tip is obliquely processed has a flat surface (rotation preventing surface) 23b in a part thereof and is formed in a substantially D shape. The adapter 40 has a disk-shaped adapter body 41, and a circular boss 42 provided on the contact surface 41c of the adapter body 41 with the second ejector plate 25 so as to project in the axial direction. Adapter body 4
A D-shaped hole 41a is formed substantially at the center of 1, and a rotation stopping surface 41b is formed in a part thereof. The head portion 23a of the ejector pin 23 is fitted into the hole 41a. And the rotation stop surface 4
A detent face 23b formed on the head portion 23a of the ejector pin 23 comes into contact with the 1b. The boss 42 is integrally molded with the adapter body 41 by resin. The boss 42 is fitted into the hole 25a of the second ejector plate 25.

The mold clamping portion 5 is supported by a plurality of tie bars 27 and 28 arranged in parallel with the ejector rod 26, and the drive system 9 causes the movable platen 4 to approach and separate from the fixed platen 3. It has become. In the injection molding machine 1 having such a configuration, the head 2 of the ejector pin 23 is
The adapter 40 is attached to 3a. At this time, the head 23a
The non-rotation surface 23b of the non-rotation surface 4 of the adapter body 41
1b, and ejector pin 2 against adapter 40
The angle of 3 is decided. Next, the ejector pin 23 to which the adapter 40 is attached is attached to the second ejector plate 25.
While aligning the boss 42 of the adapter 40 with the hole 25a of the adapter 40, the second ejector plate 25 and the movable die 22 are mounted through the through holes. In addition, the adapter 40 is second
The ejector pin 23 may be attached after the ejector plate 25 is attached.

After mounting the respective parts in this way, the movable platen 4 is pressed by the drive system 9 toward the fixed platen 3 side. The movable platen 4 moves in parallel along the upper and lower tie bars 27 and 28, and the moving die 22 comes into contact with the end surface of the fixed die 12. Then, the pressing force is maintained at a predetermined pressure to perform mold clamping. In this state, the nozzle 7 and the spool bush 10 are pushed from the injection unit 8.
Resin is injected into the cavity 31 via the.

When a predetermined time has passed after the resin injection, the movable platen 4 is retracted, and the movable mold 22 is separated from the fixed mold 12. As a result, the molded product 30 is obtained in the molding portion on the surface of the movable die 22 (FIG. 4). At this time, the molded product 30 is
The material contracts due to cooling and sticks to the surface of the moving die 22. Next, the ejector rod 26 is advanced, and the plurality of ejector pins 23 are advanced via the first ejector plate 24. The tip of the ejector pin 23 presses the bottom of the molded product 30, and the movable die 22 moves the molded product 30
To separate. At this time, since the ejector pin 23 is prevented from rotating by the adapter 40, the inclined surface formed at the tip of the ejector pin 23 accurately abuts at an angle matching the inclined surface of the bottom of the molded product 30.

In this embodiment, the rotation stopping surface 23b of the head portion 23a of the ejector pin 23 is easy to process. Further, the inclined surface at the tip can be processed by using the rotation stopping surface 23b as a reference surface, which facilitates the processing of the ejector pin 23. In addition, since a rotation stop can be provided by forming a drill hole into which the circular boss 42 is inserted in the second ejector plate 25, there is no need for processing using an end mill or the like, which facilitates manufacturing.

Other Embodiments (a) In the above embodiment, the head 2 of the ejector pin 23 is used.
Although 3a has a D-shape, it may have an oval shape, a polygonal shape, or any other structure as long as it has at least one detent surface. (B) In the above embodiment, the boss 42 is inserted into the second ejector plate 25, but it may be inserted into the first ejector plate 24. (C) Although the boss 42 has a circular shape in the above-described embodiment, it may have a quadrangular prism shape inscribed in the circular hole of the second ejector plate 25.

[0020]

As described above, by using the adapter according to the present invention, the head and the tip of the ejector pin can be easily processed, and the ejector plate can be easily processed to prevent the ejector pin from rotating. .

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of an injection molding machine according to an embodiment of the present invention.

FIG. 2 is a perspective view of an adapter and an ejector pin.

FIG. 3 is a vertical sectional view of an adapter.

FIG. 4 is a longitudinal sectional view of a main part showing the operation of the injection molding machine.

FIG. 5 is a vertical cross-sectional view showing a conventional example of an ejector plate.

FIG. 6 is a plan view showing a conventional example of a detent pin.

FIG. 7 is a plan view showing a conventional example of a rotation stop pin.

[Explanation of symbols]

 22 moving die 23 ejector pin 23b head 24, 25 ejector plate 30 molded product 40 adapter 41 adapter body 41a hole 41b non-rotating surface 41c contact surface 42 boss

Claims (1)

[Claims] 1. An adapter for mounting an ejector pin for separating a molded product from a mold at a predetermined angular position between ejector plates, the adapter head having at least one detent face. An adapter including: an adapter main body having a hole into which the portion can be inserted; a contact surface that contacts the ejector plate; and a rotation-stop boss that is provided so as to project from the contact surface of the adapter body.