JPH09193173A - Mold assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a mold body in which a slant hole forming an undercut is formed operate certainly. SOLUTION: A fixed mold 11 is divided into a cavity formed body opening and closing in a main mold opening and closing direction of the fixed mold and a movable mold 12, and a substrate 21. A slant hole formed mold 13 is, in a freely shiftable manner, incorporated in a main mold opening and closing direction into the cavity formed body 20. The slant hole formed mold 13 is pushed in a direction being apart from the cavity 15 with a coil spring 31. A hook part 42 is provided, in addition to a presser part 41 pressing the slant hole formed mold 13 against the coil spring 31, to the substrate 21. A receiving part 32 on which the hook part 42 hooks is provided to the slant hole formed mold 13. When the cavity formed body and the substrate 21 are opened, the slant hole formed mold 13 is moved basically by force of the coil spring 31. Even though force of the coil spring is shorted, the slant hole formed mold 13 starts to be certainly moved by pulling the slant hole formed mold 13 by the hook part 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold apparatus used for resin injection molding, and more particularly to a mold apparatus for molding a product having an undercut portion.

[0002]

2. Description of the Related Art For example, consider forming a product 1 as shown in FIG. This product 1 has an inclined hole 2. The inclined hole 2 is inclined with respect to the opening / closing direction of the fixed die 3 and the movable die 4, which are the main die bodies that form the outer shape of the product 1, and thus forms an undercut portion. To form such an inclined hole 2,
For example, the tilt pin 5 is incorporated in the fixed mold 3 so as to be slidable in the axial direction of the tilt hole 2. Then, prior to the mold opening of the fixed mold 3 and the movable mold 4, or with the mold opening, the inclined pin 5 is slid with respect to the fixed mold 3 to pull out from the product 1.
Do not interfere with the release of the product 1 from.

The problem is how to operate the tilt pin 5. Conventionally, the tilt pin 5 is operated by a hydraulic cylinder or an air cylinder independent of a mechanism for opening and closing the fixed mold 3 and the movable mold 4. This is to remove the tilting pin 5 with a hydraulic cylinder or an air cylinder before opening the mold, unless the hydraulic cylinder or the air cylinder itself is obstructed.
It is possible to secure certainty regarding the operation of. However, the problem is that the mold cost becomes high. Further, if there is an oil leak or an air leak, the inclined pin 5 will not operate as a matter of course, and if oil leaks, problems such as stain will occur.

[0004]

On the other hand, a mechanism for opening and closing the fixed die 3 and the movable die 4 causes the tilted pin 5 to move.
It is also possible to activate To do this, see FIG.
As shown in FIG. 3, the fixed mold 3 is divided into a cavity forming body 6 forming a cavity 6 and a base body 7, and the cavity forming body 6 and the base body 7 are arranged in the main opening / closing direction between the fixed mold 3 and the movable mold 4. It can be opened and closed freely. Then, for example, if a spring is interposed between the cavity forming body 6 and the base body 7, the cavity forming body 6 and the base body 7 are separated from each other before the cavity forming body 6 and the movable mold 4 are opened when the mold is opened. It will open.
Therefore, the tilt pin 5 may be operated in conjunction with the opening and closing of the cavity forming body 6 and the movable die 4.

Various mechanisms are conceivable for this interlocking. For example, as shown in FIG. 5, the tilt pin 5 is slidably supported on the base body 7 in the direction A orthogonal to the main opening / closing direction, and is added to the tilt pin 5 as the cavity forming body 6 and the base body 7 are opened. It is conceivable that the tilt pin 5 is pulled out from the product 1 while sliding the tilt pin 5 with respect to the base body 7 by the component force in the A direction. However, in this configuration,
The tilted pin 5 is burdened, and problems such as wear and deformation, malfunctions and molding defects due to these tend to occur. Further, even if the cam is used to operate the tilt pin 5, the same problem occurs.

In order to reduce the load applied to the tilt pin 5, as shown in FIG. 6, the tilt pin 5 is urged toward the base 7 by the spring 8 with respect to the cavity forming member 6 so that the cavity forming member 6 and the base member 6 are supported. When 7 and 7 are opened, the force of spring 8 causes tilt pin 5
Should be activated. However, at this time, the inclined pin 5 slides with respect to the base body 7. Therefore, if the spring 8 is made too strong, it may also cause wear and malfunction. On the other hand, when the force of the spring 8 is weak, the inclined pin 5 cannot follow the opening of the cavity forming body 6 and the base body 7 due to the frictional resistance between the molded product 1 and the inclined pin 5, and the product 1 There is a risk that it will remain without falling out.

The present invention is intended to solve such a problem, and an object thereof is to provide a mold apparatus capable of reliably operating the mold body without causing inconvenience such as abrasion. To do.

[0008]

In order to achieve the above-mentioned object, a first mold body, a second mold body and a first mold body which are opened and closed to form a cavity between them when the mold is closed. A mold including three molds, and the third mold is incorporated in the first mold so as to be movable in a direction inclined with respect to the opening / closing direction of the first mold and the second mold. In the apparatus, the first mold body has a cavity forming body that forms a cavity, and a base body that opens and closes in the opening and closing direction of the first mold body and the second mold body with respect to the cavity forming body. , Incorporating a third mold body into the cavity forming body,
A spring for urging the third mold body toward the cavity forming body in a direction away from the cavity is provided, and a pressing portion for pressing the third mold body against the spring is provided on the base body, and a hook portion. And a receiving portion on which the hooking portion is hooked from the cavity forming body side is provided on the third mold body.

Then, the molding material is filled in the cavity with the mold closed, and when the molding material filled in the cavity is solidified, the mold is opened and the molded product is taken out.
When the mold is opened, the base body and the cavity forming body of the first mold body are opened before opening the cavity forming body and the second mold body of the first mold body. The third mold body is pressed against the spring by the pressing portion of the base body, but as the base body and the cavity forming body are opened, the third mold body moves in a direction away from the cavity with respect to the base body by the force of the spring. . At this time, even if the frictional resistance between the third mold body and the product is greater than the force of the spring, the hooking portion of the base body catches on the receiving portion of the third mold body. Pull the mold towards the substrate. Therefore, the third mold body surely comes off from the product and does not remain without coming off from the product. After the third mold body is removed from the product, the cavity forming body of the first mold body and the second mold body are opened, and the product is taken out.

According to a second aspect of the present invention, in the mold apparatus according to the first aspect of the present invention, the hooking portion is disengaged from the receiving portion when the opening amount between the cavity forming body and the base body becomes a predetermined amount or more. is there.

By the hook portion being hooked on the receiving portion,
When the third mold body starts moving with respect to the product, the frictional resistance decreases, so it is not necessary to pull the third mold body by the hook portion. Therefore, when the cavity forming body and the base body are opened by a predetermined amount or more, the hooking portion is disengaged from the receiving portion.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a mold apparatus of the present invention will be described below with reference to FIGS. Reference numeral 11 is a fixed mold that is the first mold body, and 12 is a movable mold that is the second mold body. These fixed mold 11 and movable mold 12 move in the vertical direction in the drawing (hereinafter referred to as the main mold opening / closing direction). It opens and closes. The fixed mold 11 incorporates a tilt hole forming mold 13 which is a third mold body and a vertical hole forming pin 14 which is a fourth mold body. When the mold is closed, a product-shaped cavity 15 is formed between the fixed mold 11 including the inclined hole forming mold 13 and the vertical hole forming pin 14 and the movable mold 12. An inclined hole 17 is formed by the inclined hole forming die 13 and a vertical hole 18 is formed by the vertical hole forming pin 14 in the molded product 16. The inclined hole 17 is inclined with respect to the main mold opening / closing direction and is undercut.

The fixed mold 11 comprises a cavity forming body 20 forming a cavity 15 and a base body 21 located on the back side of the cavity forming body 20, that is, on the side opposite to the movable mold 12. The cavity forming body 20 and the base body 21 are adapted to be opened and closed by a predetermined amount in the main opening and closing direction. That is, this mold device is a so-called three-piece mold, and in addition to the first parting line PL1 between the cavity forming body 20 of the fixed die 11 and the movable die 12, the cavity forming body 20 and the base 21 are provided. Has a second parting line PL2 between them. The cavity forming body 20 and the base body 21 are configured to open and close mechanically in conjunction with opening and closing of the fixed side platen of the injection molding machine to which the base body 21 is attached and the movable side platen to which the movable mold 12 is attached. There is. Various mechanisms such as a pull link and a parting lock can be used as the mechanism for this interlocking. For example,
A spring (not shown) provided between the cavity forming body 20 and the base body 21 for urging the two in the opening direction, or
A magnet or the like that is provided between the cavity forming body 20 and the movable die 12 and attracts them can be used. As a result, when the mold is opened, first the second parting line PL2
Opens, and then the first parting line PL1 opens.

The cavity forming body 20 includes a cavity 15
The fixed-side receiving plate 24 is fixed to the back surface of the fixed-side template 23 in which the insert 22 forming the is embedded. The inclined hole forming die 13 is slidably incorporated in the cavity forming body 20 in a direction inclined with respect to the main mold opening / closing direction. The inclined hole forming die 13 includes a tubular body 25 and an inclined pin 26 coaxially fixed in the tubular body 25, and the tubular body 25 includes a fixed side mold plate 23 and a fixed side receiving plate 24. It is slidably fitted in a sleeve 27 fixed in between. Further, the inclined pin 26 has its flange-shaped head portion 28 pressed by two screws 29 and 30,
It is securely fixed to the tubular body 25. The tip end of the inclined pin 26 penetrates the fixed-side mold plate 23 and projects into the cavity 15 to form the inclined hole 17 of the product 16. Further, the inclined hole forming die 13 is urged in a direction away from the cavity 15 with respect to the cavity forming body 20 by a coil spring 31 provided between the cylindrical body 25 and the fixed side mold plate 23. Further, on the outer peripheral surface of the tubular body 25, a notch-shaped receiving portion 32 is formed at a position facing the base 21. Note that the inclined hole forming die 13 is excessively
A stopper 33 for preventing removal is provided for restricting movement in a direction away from 15.

The base body 21 has a fixed side mounting plate 36 mounted on the fixed side platen. The locking block 37 and the hook 38 are fixed to the surface of the fixed side attachment plate 36 on the side of the cavity forming body 20 by bolts 39 and 40. The locking block 37 has a front end surface that forms a pressing portion 41 that presses the inclined hole forming die 13 against the coil spring 31. The pressing portion 41 has a planar shape and is orthogonal to the moving direction of the inclined hole forming die 13. On the other hand, at the tip of the hook 38, a hooking portion 42 that hooks on the receiving portion 32 of the inclined hole forming die 13 from the cavity forming body 20 side in the main die opening / closing direction is formed. However, in this hooking portion 42, the second parting line PL2 is opened and the inclined hole forming die 13 is used as a cavity forming body.
When moving toward the base 21 with respect to 20, when the opening amount of the second parting line PL2 becomes a predetermined amount or more, it is disengaged from the receiving portion 32 in the direction orthogonal to the main mold opening / closing direction, You can't get caught. Further, the pressing portion 41
In the state where the struck the inclined hole forming die 13, a slight gap is formed between the receiving portion 32 and the hooking portion 42.
In addition, the surfaces of the receiving portion 32 and the hook portion 42 that contact each other are
It is parallel to the holding portion 41. Therefore, the receiving portion 32
Even if the hooking portion 42 is hooked on, the operation of the inclined hole forming die 13 is not hindered.

A fixed plate 46 is fixed to the surface of the fixed side mounting plate 36 on the side of the cavity forming body 20 by bolts 47. The vertical hole forming pin 14 is fixed by the flange-shaped head portion 48 being sandwiched between the fixed side attachment plate 36 and the fixed plate 46. And the vertical hole forming pin 14 is
The axial direction thereof coincides with the opening / closing direction of the main mold, the cavity forming body 20 is slidably penetrated, and the tip end portion is projected into the cavity 15.

Further, a locating ring 51 and a sprue bush 52 are fixed to the fixed side mounting plate 36. This sprue bush 52 is a cavity forming body.
It penetrates 20 slidably. The sprue 53 in the sprue bush 52 communicates with the cavity 15 via a runner 54 formed between the fixed mold 11 and the movable mold 12 that are closed.

The movable die 12 has a movable side receiving plate on the back surface of a movable side die plate 62 in which an insert 61 forming a cavity 15 is embedded.
63 and 64 are fixed. Although not shown, the movable type 12
Has a movable-side mounting plate and a protruding plate that are mounted on the movable-side platen. To this ejector plate, ejector pins 66 and 67 for ejecting the molded product 16, the sprue 53, and the resin 65 solidified in the runner 54 and releasing it from the movable die 12 are fixed.

Next, the operation of the above configuration will be described. At the time of molding, in a state where the mold is closed as shown in FIG. 1, a molten resin as a molding material is injected from a nozzle of an injection molding machine and flows into the cavity 15 through the sprue 53 and the runner 54. After the resin filled in the cavity 15, that is, the product 16, is cooled and solidified, the mold opening is performed. With this mold opening, as shown in FIG. 2, first, the cavity forming body 20 of the fixed mold 21 and the base body 21 are opened (the second parting line PL2 is opened). Along with this, the vertical hole forming pin 14 comes out of the vertical hole 18 of the product 16. At the same time, the inclined hole forming die 13 moves in a direction away from the cavity 15 with respect to the cavity forming body 20 by the force of the coil spring 31 while being pressed by the pressing portion 41 of the locking block 37, and the inclined hole of the product 16 is formed. Exit from 17. At that time, the inclined hole forming die 13 slides on the pressing portion 41.

When the second parting line PL2 starts to open, even if the frictional resistance between the inclined hole forming mold 13 and the product 16 exceeds the force of the coil spring 31, the hook 38 of the base 21 is pulled. The hanging portion 42 is hooked on the receiving portion 32 of the inclined hole forming die 13, and the inclined hole forming die 13 is pulled toward the base 21 in the main mold opening / closing direction. Therefore, the inclined hole forming mold 13 is
It surely comes out from the inclined holes 17 of the 16 and never remains without coming off from the product 16. Since the positional relationship between the base body 20 and the inclined hole forming die 13 changes also in the direction orthogonal to the main mold opening / closing direction, when the second parting line PL2 is opened by a predetermined amount, the hooking portion 42 receives the receiving portion 32. Get out of. However, once the inclined hole forming die 13 starts to move with respect to the product 16, the resistance decreases, so that the inclined hole forming die 13 continues to move only by the force of the coil spring 31. Therefore, when the second parting line PL2 is opened to some extent, the hooking portion 42 does not come off the receiving portion 32, which causes no problem. Rather, by allowing the hook portion 42 to come off the receiving portion 32, the hook portion 42
Also, the receiving portion 32 can be made small, and a manufacturing advantage can be obtained.

When the second parting line PL2 is completely opened, this time, as shown in FIG. 3, the cavity forming body 20 of the fixed mold 11 and the movable mold 12 start to open (the first parting line PL1 is Start opening). Accordingly, the product 16 separates from the fixed mold 11 and remains on the movable mold 12 due to the difference in the mold release resistance of the product 16 with respect to the fixed mold 11 and the movable mold 12. Similarly, the resin for the sprue 53 and runner 54 is also fixed
It moves away from 11 and stops at the movable mold 12. Before the first parting line PL1 is opened, not only the inclined hole forming mold 13 but also the vertical hole forming pin 14 is removed from the product 16 by reducing the mold release resistance. This is to ensure that the product 16 separates from the fixed mold 11 when the PL1 opens.

Then, the resin 16 in the product 16, the sprue 53 and the runner 54 is ejected by the ejecting pins 66 and 67, separated from the movable die 12, and taken out. Thereafter, the mold is closed again, and the above steps are repeated. When the mold is closed, the first parting line PL1 is first closed and then the second parting line PL2 is closed, which is the reverse of the mold opening. Then, the inclined hole forming die 13 is pushed and moved by the pressing portion 41 of the locking block 37, and is regulated by the pressing portion 41 to be located at a predetermined position in the mold closed state. In this state, the inclined hole forming die 13 is in contact with the movable die 12.

As described above, according to the structure of the above-described embodiment, the inclined hole forming die 13 forming the inclined hole 17 which is the undercut portion is operated by the spring 31 when the die is opened,
In addition, a hook portion is provided to assist in starting the inclined hole forming mold 13.
By providing 42 and the receiving portion 32, the inclined hole forming die 13 can be reliably operated without causing inconveniences such as wear and deformation.

By the way, the inclined pin 26 of the inclined hole forming die 13 forming the inclined hole 17 of the product 16 is relatively easily worn,
When the inclined pin 26 is worn out, it can be dealt with by replacing only the inclined pin 26.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the above-described embodiment, the undercut portion of the product 16 is the inclined hole 17
However, the undercut portion is not limited to the hole, and may be a cutout portion or the like. Further, various detailed configurations of the mold device are possible.

[0026]

According to the invention of claim 1, of the first mold body, the second mold body and the third mold body forming the cavity, the first mold body is the first mold body. And a cavity forming body that opens and closes in the opening and closing direction of the second mold body, and a third mold body is movably incorporated in the cavity forming body in a direction inclined with respect to the opening and closing direction. Three
A spring for urging the mold body away from the cavity is provided, and a pressing portion for pressing the third mold body against the spring and a hooking portion are provided on the base body. Since the hanging portion is provided with the receiving portion that is hooked from the cavity forming body side, when opening the die, first opening the base body and the cavity forming body to remove the third die body from the molded product, Even if the frictional resistance between the mold and the product of No. 3 is greater than the force of the spring, the hook portion of the base body catches on the receiving portion of the third mold body, and the third mold body is moved toward the base body. By pulling in, the third mold is surely removed from the product. Therefore,
Since it is not necessary to make the spring force excessively strong, problems such as wear do not occur.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the hooking portion is disengaged from the receiving portion when the opening amount between the cavity forming body and the base body becomes a predetermined amount or more. Therefore, the hooking portion and the receiving portion can be made small, which is advantageous in manufacturing.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment of a mold device of the present invention in a mold closed state.

FIG. 2 is a sectional view showing a state in which a second parting line is opened in the same as above.

FIG. 3 is a sectional view showing a state in which a first parting line is also opened.

FIG. 4 is a cross-sectional view showing an example of a conventional mold device.

FIG. 5 is a cross-sectional view showing an example conceivable as a mold device for forming an inclined hole.

FIG. 6 is a cross-sectional view showing another example that can be considered as a mold device that forms an inclined hole.

[Explanation of symbols]

 11 Fixed mold (first mold body) 12 Movable mold (second mold body) 13 Inclined hole forming mold (third mold body) 15 Cavity 20 Cavity forming body 21 Base 31 Coil spring 32 Receiving part 41 Holding part 42 Hooking part

Claims (2)

[Claims] 1. A first mold body, a second mold body, and a third mold body that open and close each other to form a cavity between the mold bodies when the mold is closed, and the third mold body is the first mold body. In the mold device in which the first mold body and the second mold body are movably installed in a direction inclined with respect to the opening / closing direction, the first mold body is a cavity forming body that forms a cavity. A base that opens and closes in the opening and closing direction of the first mold body and the second mold body with respect to the cavity forming body, and incorporates a third mold body into the cavity forming body, and
A spring for urging the mold body with respect to the cavity forming body in a direction away from the cavity, and a pressing portion for pressing the third mold body against the spring against the spring, and a hooking portion, A mold device, wherein the third mold body is provided with a receiving portion for catching the catching portion from the cavity forming body side. 2. The mold apparatus according to claim 1, wherein the hooking portion is disengaged from the receiving portion when an opening amount between the cavity forming body and the base body becomes a predetermined amount or more.