JP3259898B2 - Injection mold release device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold releasing apparatus for an injection molding die, and more particularly to a multi-projecting type.

[0002]

2. Description of the Related Art FIG. 10 shows a conventional apparatus and a reference example. FIG. 1A shows a conventional example, in which an injection-molded article 2 having a mold 1 formed thereon.
The injection molded article 2 is formed in a multi-step process in which the amount of protrusion is partially changed in accordance with a partial change in the magnitude of the release resistance by the protrusion pin 4 attached to the protrusion plate 3 and the pin 6 of the cylinder 5. Releases to prevent whitening and cracking.

FIGS. 10B and 10C show a reference example in which the release mechanism changes in two stages. A boss 7 integral with the injection-molded product 2 is moved around the pin 6 provided on the cylinder 5. This is an example in which the boss 7 and the pin 6 are injection-molded and joined together with a large release resistance. Reference numeral 8 in the figure indicates the cylinder 5
This is a stationary part that supports

In this case, first, from the state (B) in which the pins 6 enter the boss 7 and are integrally connected, the pins 6 are retracted and removed from the boss 7 (C), and thereafter, the protrusion 6 is integrally formed with the protrusion plate 3. The whole injection molded article 2 is released by the pins 4.

[0005]

If there is a part having a remarkable mold release resistance due to the shape of the injection molded product, such as a boss formed around the pin, if this part is forcibly protruded with a protruding pin or the like, May cause cracking and whitening.

On the other hand, such a problem can be solved by projecting in multiple stages as in the above-mentioned conventional example, but a complicated and expensive metal mold is required, and the whole becomes large and maintenance is required. It becomes troublesome.

[0007]

The present invention will be described with reference to FIG. 1 showing the principle of the present invention. 1A shows an injection molding step, B shows a mold opening step, C shows an initial release position protruding step, and D shows a final release position protruding step.

As shown in FIG. 1, a molten resin is injected into a cavity formed in a mating surface of a male mold 10 and a female mold 11, which are injection molds, to form an injection molded product 12 having a predetermined shape. The male mold 10 has a protruding pin 1
The slide core 4 and the slide core 16 are provided so as to be movable forward and backward.

The tip 30 of the slide core 16 is exposed into the cavity during injection molding, and a boss 18 integral with the injection molded product 12 is formed around the tip. The boss 18 and the distal end 30 of the slide core 16 have a relatively strong coupling relationship, and are the parts that generate the greatest release resistance.

The protruding pin 14 is protruded from the mold surface at the time of release by a mechanism (not shown), and is released around the boss 18.
The portion where the resistance is small is pushed, and the amount of protrusion is slightly increased from the mold surface 32 integrally with the slide core 16 (the amount of protrusion s) integrated with the boss 18 at the initial release position (C). Boss 1 of the injection-molded product 12
8 to a final release position (D) where the slide 8 is separated from the tip 30 of the slide core 16.

The movement of the slide core 16 in the protruding direction is as follows.
When the injection-molded product 12 is pushed out to the initial release position, the boss 18 is connected to the tip 30 and moves by the resilient force of the push-out spring 27, which is an example of a spring member, and the force of the push-out pin 14. Stops before the release position or the final release position.

However, the movement of the slide core 16 may be synchronized with the push-out pin 14 and performed by an independent force by a mechanism different from the push-out mechanism on the push-out pin 14 side.

The stop position of the slide core 16 is set such that the boss 18 is sufficiently separated from the tip 30 at the final release position.

In the present invention, the presence of the boss 18 is not always necessary, and the release resistance is larger than that of the other parts in the state where the tip 30 of the slide core 16 bites into a part of the injection molded product 12. It is sufficient if they are connected to each other as required.

[0015]

As shown in FIG. 1, as shown in FIG.
The molten resin is injected into a cavity formed on the mating surface of the slide core 16 to form an injection molded product 12 having a predetermined shape, and at the same time, a boss 18 integral with the injection molded product 12 is formed around the distal end 30 of the slide core 16 (A). ) And then open the mold (B).

[0016] The pin 14 followed by projecting Shi protrude only s
Press release resistance is small portion around the boss 18 Te strike, the initial release position releases slightly entire injection molded article 12 from the mold surface 32 of the male 10 (C).

At this time, since the boss 18 and the tip 30 of the slide core 16 have a relatively stronger connection relationship than the other parts to be released, the slide core 16 is integrated with the injection-molded product 12 and is pushed out by the pushing spring 27. It moves with the resilience and the force of the protruding pin 14.

That is, in the injection-molded article 12, at the initial release position, a portion having a small release resistance first separates from the mold surface 32 first.
A portion where the release resistance between the boss 18 and the tip 30 of the slide core 16 is large is left without being released.

When the protruding pin 14 is further protruded from this state (protruding amount Ss), the final release position is reached (D). Since the slide core 16 has stopped moving at the initial release position or thereafter, the boss The tip 18 is also separated from the tip 30, and the entire injection molded article 12 is completely released.

In this way, since the protrusion load can be dispersed in multiple stages, the mold can be easily released without causing whitening or cracking, and the structure of the slide core 16 can be made simpler than in the case where a conventional cylinder is used. Therefore, the entire mold structure can be made simple and small in size, cost can be reduced, and maintenance becomes easy.

Further, the slide core 16 is moved by the elastic force of the pushing spring 27 and the force of the projecting pin 14,
And since constitute a part of the slide core 16 between the initial release position of the final release position so as to stop by abutting to the stationary portion of the mold side, leaving the structure of the slide core 16 more easily .

Further, the injection molded article 12 is formed by integrally forming the boss 18 and the tip 30 of the slide core 16 is fitted to the boss 18 so that the boss 18 is formed.
Even when the release resistance is the largest in the portion, the release can be easily performed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 2 is a cross-sectional view of the entire mold structure, FIG. 3 is a cross-sectional structure of a main part of injection molding, FIG. 4 is a cross-sectional structure of a main part when the mold is opened, FIG. 6 is a sectional view of a main part in a step of projecting the final release position, FIG. 7 is a sectional view of a guide member side portion of the slide core at a stage corresponding to the fourth position, FIG. 8 is a similar view at a stage corresponding to FIG. FIG. 9 is a view similar to that of FIG.

First, in FIG. 2, this injection molding die has a divided structure of a male die 10 and a female die 11, a cavity is formed in the mating surface, and a predetermined shape is formed by injecting a molten resin into the cavity. An injection molded product 12 is formed.

The male mold 10 is provided with a release mechanism 20. The release mechanism 20 includes a protruding rod 21 (FIG. 4).
6), a protrusion pin 14 attached to the protrusion plate 13 which moves forward and backward, and a slide core 16 supported by the immovable member 15 and moving independently of the protrusion plate 13.

As shown in FIG. 7, the base portion 22 of the slide core 16 has a concave space 2 formed on the side surface of the immobile member 15.
3 can be moved in the long axis direction, and when the projecting portion 24 in the direction perpendicular to the axis is in the initial release position, it comes into contact with the stopper 17 on the stationary member 15 side to stop the movement. Has a movable stroke d.

The end of the base 22 is prevented from coming off by a pressing member 25, and the pressing member 25 is mounted in the recessed space 23 with a bolt 26, and a pushing spring 27 is elastically mounted between the pressing member 25 and the base 22. I have.

Reference numeral 28 in FIG. 2 denotes a return pin for the entire projecting plate 13, and 29 denotes a spring for pushing the projecting plate 13.

Further, a boss 18 is integrally formed with a part of the injection-molded article 12 so as to enter into the thickness of the male mold 10, and this boss 18 is exposed at the tip 3 exposed into the cavity.
It is formed around 0.

Since the boss 18 is relatively long, the space between the boss 18 and the tip 30 corresponds to a portion having a remarkably large release resistance as compared with other portions. The depth of the fitting portion between the boss 18 and the tip 30 is It is equal to the length D of the boss 18.

Next, the operation of the present embodiment will be described. FIG.
A, FIG. 2 and FIG. 3 show the same steps at the time of injection molding, respectively. In this step, the protruding plate 13 contacts the immovable member 15 and is in a state before protruding, and the boss 1 integrated with the injection molded product 12 around the distal end 30 of the slide core 16.
8 are formed.

FIGS. 1B, 4 and 7 show the same steps when the mold is opened. At this stage, only the female die 11 is separated from the male die 10, and the release mechanism 20 side is not changed. As shown in FIG. Is formed with a movable stroke d.

FIGS. 1C, 5 and 8 are views showing the same process at the stage of projecting to the initial releasing position. At this stage, the projecting plate 13 moves toward the female mold 11 by a dimension of s. .

As a result, each end 31 of the protruding pin 14
Is low in the mold release resistance around the boss 18 in the injection molded product 12
The part is pressed slightly to separate the whole from the mold surface 32 of the male mold 10, and the part having a small release resistance is the initial release position where the mold is released.

At this time, the slide core 16 has a part where the boss 18 and the front end 30 are fitted to each other with a remarkably large release resistance, and the extrusion spring 27 is elastically mounted on the base of the slide core 16. It moves together with the product 12 and consequently moves in synchronization with the protruding pin 14.

When the slide core 16 moves by the dimension corresponding to the movable stroke d, as shown in FIG. 8, the projecting portion 24 comes into contact with the stopper 17, and further movement in the projecting direction is restricted. When the movement is restricted at the initial release position, d = s.

FIGS. 1D, 6 and 9 show the same step in the step of projecting the final release position. The projecting plate 13 is further moved, and the projecting pin 14 at this time is moved.
Is defined as S.

However, the slide core 16 is not
4 is in contact with the stopper 17 so that the movement of the injection molded product 12 is restricted.
Of the slide core 16 is separated from the tip 30 of the slide core 16.

That is, when the length of the boss 18 is D and the movable stroke is d and substantially equal to s, the stroke (S-S) of the ejection pin 14 from the initial release position to the final release position is determined.
If s) is greater than D, the boss 18 separates from the tip 30.

As described above, in the first-stage protrusion at the initial release position, a portion having a relatively small release resistance is released first, and then at the second-stage protrusion at the final release position. Since only the portion having a remarkably large release resistance is released, the concentration of the protruding load can be reduced, and the injection molded product having a relatively complicated shape can be easily released.

Further, since it is not necessary to use a complicated mold release mechanism using a cylinder or the like as in the prior art, and a simple structure can be realized, the overall size and cost can be reduced, and the maintainability is improved.

In addition, the slide core 16 is protruded by using the resilience of the pushing spring 27 mounted on the base of the slide core 16 and the mold release resistance between the tip 30 of the slide core 16 and the boss 18. Since the force is used to push out the pin 14,
There is no need to provide a tuning mechanism for the above. Therefore, it is particularly effective for molding an injection molded article having a boss.

Further, the movement of the slide core 16 is restricted.
Since the movement is performed by the contact between the overhang portion 24 and the stopper 17, the movement of the slide core 16 can be controlled with a simple structure.

The present invention is not limited to the above-described embodiment, but can be variously modified. For example, the number of protruding steps is 2
The above plurality of stages can be arbitrarily performed. In this case, the separation between the tip 30 of the slide core 16 and the boss 18 may be performed before the final stage.

When a large number of bosses are provided, the slide cores fitted with the bosses can be separated at different stages. Further, an independent projection mechanism for the slide core 16 can be provided. In addition, as the push-out spring 27, not only a coil spring but also a suitable spring member such as a leaf spring can be used.

[Brief description of the drawings]

FIG. 1 is a diagram showing each process from injection molding to release.

FIG. 2 is a cross-sectional view of the entire injection molding die.

FIG. 3 is a sectional view of an injection molding process.

FIG. 4 is a sectional view of a mold opening process.

FIG. 5 is a cross-sectional view of a step of projecting an initial release position.

FIG. 6 is a cross-sectional view of a step of protruding a final release position.

FIG. 7 is a sectional view of a slide core base in a mold opening process.

FIG. 8 is a sectional view of the same in a step of protruding an initial release position.

FIG. 9 is a sectional view of the same in a step of projecting a final release position.

FIG. 10 is a diagram showing a release method of a conventional example and a reference example.

[Explanation of symbols]

10: male mold, 11: female mold, 12: injection molded product, 13: protrusion plate, 14: protrusion pin, 15: immovable member, 1
6: slide core, 17: stopper, 18: boss, 2
7: Extrusion spring, 30: Tip

Claims (2)

(57) [Claims] 1. A mold release device for an injection molding die provided for releasing an injection molded product, comprising: a protruding pin and a slide core, wherein the protruding pin slides the entire injection molded product when releasing the mold. what to change to the initial release position projecting slightly from the die surface together, and the final release position to separate from the slide core injection molded article protrude further increased from this position and
In addition, the protruding pin reduces the release resistance of the injection molded product at the time of release.
Press again portion, the slide core is partially injection-molded article during the injection molding
Release resistance formed integrally with and around the slide core
Is combined with the large part and moves in the protruding direction together with the injection molded product by the spring member , and a part of the slide core
The contact between the stationary portion of the mold-side as well as stop moving before the final release position, the mold release resistance is large portions slide in the initial release position
The slide core does not separate from the
The ejection pin pushes out the injection molded product to the final release position.
A mold release device for an injection mold, wherein the mold is separated from the slide core by the following steps . 2. The injection molding apparatus according to claim 1, wherein
The mold release device for an injection mold according to claim 1, wherein the boss is formed integrally with the molded product .