JPH10202704A - Two-stage mold release type injection mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the injection mold capable of taking out a molded product automatically, safely and certainly, which is good in productivity. SOLUTION: This mold is constituted so as to mold a molded product 21 having an undercut part 22 provided in the inside thereof. In this case, the mold in constituted of a fixed mold consisting of a fixed attaching plate 11 and a fixed template 12 and a movable mold successively consisting of a stripper plate 13, an intermediate plate 14, a movable template 15, a receiving plate 16, a spacer block 17 and a movable attaching plate 18. At the time of mold opening after molding, a molded product is fitted to a core upper part 24 of the movable mold from the fixed mold by its undercut part 22 and the intermediate plate of the movable mold is stopped on the way of mold opening by a connection part 31 of the fixed template of the fixed mold and the intermediate plate of the movable mold to separate a core main body 23 of the movable mold from the core upper part in a mold opening direction and the stripper plate 13 is moved toward the fixed mold by an ejection rod 32 immediately after the completion of mold opening to release the molded product fitted to the core upper part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-stage release type injection molding die for molding a molded article having an undercut portion inside.

[0002]

2. Description of the Related Art Conventionally, when molding a molded product having an undercut portion (a portion that is caught when being taken out from a mold) by an injection molding method, a two-stage release type injection molding die is used. During opening, the molded product that fits into the core of the movable mold at the inner undercut portion is released by a two-stage operation.

For example, in a conventional two-stage release type injection mold (10) shown in FIG. 2 (a), molten resin flows from a nozzle of an injection molding machine into a sprue (19) and a runner (20). Is injected from the gate into the cavity through the gate and cooled, and after the molded product (21) is formed, the mold is opened,
The fixed mold and the movable movable mold are separated from the parting line (PL), and the molded product (21) fits into the upper part (24) of the movable mold at the inner undercut (22). And release it from the fixed mold. Then, during the opening of the mold, the ejector plate (28) protrudes and the rod (32)
Mechanically at the step (3) inside the spacer block (17).
2 (b), the ejector plate (27) which comes into contact with the ejector plate (28) is also projected, and the core which is connected to the ejector plate (27) by the pin (25), as shown in FIG. 2 (b). From the upper part (24) and the stripper plate (13) connected to the ejector plate (28) by the pin (26), the core body (23) and the movable mold plate (1) are formed.
5) is separated, and the lower part of the undercut part (22) of the molded product (21) fitted to the upper part (24) of the core is in a free state. In addition, the movable mold is opened,
On the way, the stripper plate (13) stops at a connecting part (31) such as a link between the fixed mold and the fixed mold plate (12) as shown in FIG. When the core upper portion (24) connected by the pin (26) to the ejector plate (28) in contact with the step (30) inside the spacer block passes through the core insertion hole of (13), the outer side of the core upper portion is removed. The molded product (21) fitted to
The stripper plate (13) is repelled and released from the periphery of the core insertion hole of the stripper plate (13), and the mold opening is completed.

[0004]

However, in the above-mentioned conventional two-stage release type injection molding dies, recently, in order to perform automatic removal of a general molded product, the movable die is still moving. Since the molded product is released from the mold, it is difficult to obtain a timing by an electric signal for inserting the suction device for automatic removal of the molded product into the mold, and there is a fear that an accident is likely to occur.

The present invention solves the above-mentioned problem of the conventional two-stage release type injection molding die, and it is easy to take the timing of the automatic removal of the molded product by the electric signal, so that the automatic removal of the molded product is safe. It is intended to provide a two-stage release type injection molding die which can be surely performed with high productivity and has good productivity.

[0006]

That is, according to the present invention, as shown in FIG. 1A, an undercut portion (2
An injection mold for molding a molded product (21) having 2), comprising: a fixed mold comprising a fixed mounting plate (11) and a fixed mold plate (12); and a stripper plate (13). , Intermediate plate (14), movable mold plate (15) and receiving plate (16)
And a movable mold including a spacer block (17) and a movable mounting plate (18). When the mold is opened after molding, as shown in FIG. The molded product (21) is placed above the core of the movable mold (24).
To the undercut portion (22) and release the mold,
In the middle of mold opening, the fixed mold plate (12) of the fixed mold
Connecting part (3) between the movable side mold and the intermediate plate (14)
According to 1), the intermediate plate (14) of the movable mold is stopped, and the core body (23) of the movable mold is separated from the core upper part (24) in the mold opening direction. Next, as shown in FIG. 1C, the stripper plate (13) is moved in the direction of the fixed mold by the protruding rod (32), and the molded product ( 21) A two-stage release type injection molding die (10) characterized by releasing the mold from (21).

[0007]

In the two-stage release type injection molding mold of the present invention, immediately after the mold opening is completed, the stripper plate is moved in the direction of the fixed mold by the protruding rod to form the molded product fitted on the upper part of the core. Since the mold is released, the operation signal of the protruding rod can be used as the operation signal of the automatic removal device for the molded product. The timing of removal of the molded product is easy, and the molded product is removed because the movable mold is stopped. The position is stable, and the molded product can be safely and reliably removed from the mold by the automatic removal device.

Further, unlike a conventional two-stage release type injection molding die, since the molded product is not released while the movable die is moving, the speed of opening the mold is slowed down and the molded product is released. It is not necessary to perform the molding, and the molding time can be shortened, and the productivity is improved.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A two-stage release type injection molding die according to the present invention is for molding a molded product having an undercut portion inside, as shown in FIGS. 3 (a) and 3 (b). An undercut portion (22) on one side inside the molded product (21)
Or as shown in FIG. 4 (a) or (b),
Undercut part (22) inside the top part of molded product (21)
This is an injection molding die for molding a product having an undercut portion (22) below a peripheral wall of a molded product (21).

FIG. 1A, FIG. 1B and FIG. 1B show a two-stage release type injection molding die according to one embodiment of the present invention for molding a molded product having an undercut on one side inside. c)
This will be described with reference to FIG.

This two-stage release type injection mold is shown in FIG.
As shown in (a), a fixed mold including a fixed mounting plate (11), a sprue (19), a runner (20), a fixed mold plate (12) in which a gate and a cavity are provided, and
A movable die plate (15) into which a core body (23) having a core upper part (24) to be separated is inserted, a stripper plate (13) and an intermediate plate (14) forming a core insertion hole, and a receiving plate (1).
6) The movable mold includes a spacer block (17) for accommodating the two-stage ejector plate (28) inside, and a movable-side mounting plate (18) having a protruding lot hole. The stripper plate (13) includes a movable mold plate (15), a receiving plate (16), and a spacer block (17).
The intermediate plate (14) is connected to a pin (26) that penetrates through the ejector plate (28) inside and is inserted into a protruding lot hole of the movable-side mounting plate (18). And a pin (29) penetrating through the receiving plate (16) and connecting to the ejector plate (28) in the spacer block (17), and a connecting part such as a fixed mold plate (12) and a link. (31), and the upper part of the core is connected to a pin (25) that passes through the core body (23) and the receiving plate (16) and connects to the ejector plate (28) in the spacer block (17). I have.

Then, the molten resin is injected from the nozzle of the injection molding machine through the sprue (19) and the runner (20) from the gate into the cavity, and cooled to form a molded product (21).
Is formed, the mold is opened, the fixed mold and the movable mold are separated from the parting line (PL), and the molded product (21) is separated by the inner undercut (22) into the core of the movable mold. It is fitted to the upper part (24) and released from the fixed mold. Then, during the opening of the mold, as shown in FIG. 1 (b), the intermediate plate (14) of the movable mold is connected to the fixed mold plate (12) by the connecting part (31). The core body (23) is separated from the core upper part (24) in the mold opening direction by the movable side mold plate (15) which stops and mold is opened, thereby terminating the mold opening, and as shown in FIG. 1 (c). Then, the pin (26) inserted into the protruding lot hole of the movable-side mounting plate (18) is protruded by the protruding rod (32) of the protruding device of the molding machine, and the stripper plate (13) is moved in the direction of the fixed-side mold. Then, the molded product (21) fitted to the core upper part (24) is flipped up at the periphery of the core insertion hole of the stripper plate (13) and is released.

The operation timing of the overhang lot is as follows.
Since it can be set arbitrarily in terms of time, deformation of the undercut portion due to mold release can be minimized, and the operation signal of this protruding lot can be used as the operation signal of the automated removal device for molded products . Further, the total thickness of the mold can be relatively small.

[0014]

According to the present invention, when a molded article having an undercut portion inside is molded using the two-stage release type injection molding die of the present invention, the molded article can be safely and reliably taken out by an automatic ejection device. , The total thickness of the mold is relatively small,
Since there is no need to slow down the mold opening speed and release the molded product, the molding time can be reduced, and the productivity is good.

In the molded article molded by using the two-stage release type injection molding die of the present invention, since the operation timing of the protruding lot is appropriately performed, the deformation of the undercut portion at the time of release is extremely small. Less and good quality.

[Brief description of the drawings]

FIG. 1A is an explanatory diagram showing a state of a two-stage release type injection molding die according to an embodiment of the present invention at the time of mold clamping;
(B) is an explanatory view showing a state during the mold opening,
(C) is an explanatory view showing a state when the molded product is released from the mold.

FIG. 2 (a) is an explanatory view showing a state of a conventional example of a two-stage release type injection molding mold at the time of mold clamping, and FIG.
It is explanatory drawing which shows the state in the middle of the mold opening, (c) is
It is explanatory drawing which shows the state when the molded article is released.

FIG. 3A is a cross-sectional view of an example of a molded product having an undercut inside, and FIG. 3B is a bottom view thereof.

FIGS. 4A and 4B are cross-sectional views of another example of a molded product having an undercut on the inside, respectively.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Injection molding die 11 ... Fixed side mounting plate 12 ... Fixed side mold plate 13 ... Stripper plate 14 ... Intermediate plate 15 ... Movable side mold plate 16 ... Receiving plate 17 ... Spacer block 18 ... … Movable side mounting plate 19… sprue 20… runner 21… molded product 22… undercut part 23… core body 24… core upper part 25… pin 26… pin 27… ejector plate 28… Ejector plate 29 Pin 30 Step 31 Connecting part 32 Projecting rod PL Parting line

Claims (1)

[Claims] 1. An injection molding mold for molding a molded article having an undercut portion inside, comprising: a fixed mold having a fixed mounting plate and a fixed mold plate; a stripper plate and an intermediate plate in order. The movable mold includes a movable mold plate, a receiving plate, a spacer block, and a movable mounting plate.The mold is opened from the fixed mold when the mold is opened after molding. The undercut portion is fitted to the upper part of the core to release the mold. During opening of the mold, the movable part is fixed by a connecting part between the fixed mold plate of the fixed mold and the intermediate plate of the movable mold. The intermediate plate of the mold is stopped, and the core body of the movable mold is separated from the upper part of the core in the mold opening direction. Immediately after the mold opening is completed, the stripper plate is moved in the direction of the fixed mold by a projecting rod. To release the molded product that fits on top of the core. Two-stage release system injection mold for causing.