JP2672708B2 - Resin mold - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin molding die for obtaining a molded product by injecting a molten resin into a cavity having a predetermined shape and curing the resin, and particularly to a molded product. The present invention relates to a resin molding die suitable for providing an undercut portion.

[Conventional technology]

FIG. 7 is a sectional view showing a conventional example of a resin molding die, and FIG. 8 is a sectional view taken along the line CC of FIG.

The molded product 1 shown in FIG. 7 has a pair of protrusions 2 and 3. The tips of the protrusions 2 and 3 form undercut portions 2a and 3a formed in a direction orthogonal to the mold opening / closing direction and face each other.

Conventionally, a resin molding die for molding such a molded article 1 is formed on a movable die 4 and a fixed die 5 and a joint surface between the movable die 4 and the fixed die 5, and the illustration thereof is omitted. The cavity 6 filled with the molten resin and the protrusions 2 and 3
And a slide core 7 that is provided on the side of and that forms the inner portion of the protrusions 2 and 3. This slide core 7
Is movable in a direction orthogonal to the mold opening / closing direction. For example, it moves to the right in FIG. 8 with the mold opening operation, and moves to the left in FIG. 8 with the mold closing operation. It is about to move.

In this conventional resin mold, when the movable mold 4 is closed with respect to the fixed mold 5 when molding the molded product 1, the slide core 7 moves leftward in FIG. as a result,
Since the cavity 6 is formed by the movable die 4, the fixed die 5 and the slide core 7, the cavity 6 is filled with a molten resin and cured. Next, when taking out the molded product 1, when the movable mold 4 is opened with respect to the fixed mold 5, the slide core 7 moves to the right in FIG. Undercut parts 2a, 3a of 7
Is released. After that, the molded product 1 is removed from the movable mold 4 by a protruding pin (not shown) protruding.

[Problems to be solved by the invention]

By the way, in the above-described conventional resin molding die, since the moving portion of the slide core 7 located on the side of the protruding bodies 2 and 3 needs to be kept in a flat state, the protruding portion is designed when the molded product 1 is designed. There is a problem that the degree of freedom in design is small because of restrictions such as the provision of protrusions on the sides of the bodies 2 and 3 and disposition of protrusion pins.

The present invention has been made in view of the actual situation in the prior art, and an object thereof is to provide an undercut portion without requiring a slide core that moves in a direction orthogonal to a mold opening / closing direction. An object is to provide a resin molding die capable of molding a molded product.

[Means for solving the problem]

In order to achieve this object, the present invention provides a movable mold and a fixed mold, a cavity formed on a joint surface of the movable mold and the fixed mold and filled with a molten resin, and the movable mold. In the resin molding die, which is provided so as to be movable relative to one another, and which has an ejection pin for excluding a molded article formed in the cavity from the movable die, and an operating body for moving the ejection pin by a predetermined distance, the ejection pin is The movable die is provided with a slide cam that is arranged in parallel and that forms an undercut portion of the molded product, and a contact portion that abuts when the slide cam moves a predetermined distance smaller than the predetermined distance. ,
Either one of the slide cam and the actuating body,
A long hole parallel to the moving direction of the actuating body is formed, and a connecting pin to be inserted into the long hole is provided on the other side.

[Action]

Since the present invention is configured as described above, after molding the molded product with the movable mold closed with respect to the fixed mold and opening the mold, the movable body is moved in the forward direction through the ejector pin. As the molded product moves, the slide cam engages with the undercut part of the molded product, so that the slide cam also moves, and when it moves a predetermined distance thereafter, the contact part contacts the contact part. It abuts and the slide cam stops.

Then, since the actuation body tries to continue moving further, the connecting pin provided on the other side moves along the movement direction of the actuation body in the elongated hole formed in either one of the actuation body and the slide cam. As it does, the ejector pin moves further. As a result, even though the slide cam is stopped as described above, the molded product is pressed by the protrusion pin, so that the undercut portion of the molded product is elastically deformed and separated from the slide cam, The molded product is removed from the movable mold.

Then, as the actuating body moves in the backward direction, the protruding pin is returned to the original position, and the slide cam is also returned to the original position via the connecting pin, so that the mold can be closed.

As a result, it is possible to mold a molded product having an undercut portion without requiring a slide core that moves in a direction orthogonal to the mold opening / closing direction.

〔Example〕

Embodiments of the resin molding die of the present invention will be described below with reference to the drawings.

1 to 6 are views for explaining one embodiment of the resin molding die of the present invention. FIG. 1 (a) is a perspective view of a molded product seen from the front side, and FIG. 1 (b) is FIG. 2 is a perspective view of the molded product viewed from the back side, FIG. 2 is a plan view of the molding die, FIG.
(B) is a sectional view showing a state at the time of molding, FIG. 4 is an enlarged sectional view showing a state where the slide cam engages with the undercut portion of the molded product, and FIGS. 5 (a) and 5 (b) are actuating bodies. FIG. 6 (a) is a cross-sectional view showing a state in which is raised to the middle of a predetermined distance.
(B) is a cross-sectional view showing a state in which the actuating body is raised to the moving end. 3 (a), 5 (a) and 6 (a) are sectional views taken along the line AA of FIG. 2, respectively.
FIG. 3 (b), FIG. 5 (b) and FIG. 6 (b) are sectional views taken along the line BB of FIG.

The molded product 11 shown in FIGS. 1 (a) and 1 (b) is made of synthetic resin and has projections 12, 13, 14, 15 on the back surface side.
Of these protrusions 12 to 15, for example, a pair of protrusions 12,
Each tip of 13 constitutes undercut portions 12a and 13a formed in a direction orthogonal to the mold opening / closing direction and face each other. Similarly, the other protrusions 14 and 15 are provided with undercut portions 14a and 15a, respectively. A wall 16 is formed on the sides of the protrusions 12 and 13, and a wall 17 is also formed on the sides of the protrusions 14 and 15.

As shown in FIGS. 3 (a) and 3 (b), the resin molding die of this embodiment for molding such a molded product 1 has a movable mold 21.
And a fixed die 22, a cavity 23 formed on a joint surface of the movable die 21 and the fixed die 22 and filled with a molten resin (not shown), and the movable die 21 are provided so as to be movable relative to each other. And a protruding pin 24 for removing the molded product 11 molded in the cavity 23 from the movable mold 21, an operating body for moving the protruding pin 24 by a predetermined distance, for example, 20 mm, for example, the protruding plate 25, and this protruding plate. A return pin 26 whose lower part is fixed to 25, a return spring 27 which is inserted into the return pin 26 and applies a force to the protruding plate 25 and the movable mold 21 in a direction separating from each other, and a molded product.
It has a relatively movable slide cam 28 for molding the inside of the protrusions 12, 13 of 11 and a similar slide cam 29 for molding the inside of the other protrusions 14, 15.

The movable mold 21 described above is located above the protruding plate 25, and the mold plate 31 into which the return pin 26 is inserted and the mold plate 31.
The backing 32 provided on the top and the main nest 33 provided on the backing 32 and for molding the lower side of the molded product 11.
And pressing plates 34 and 35 that are fastened on the template 31 and press the slide cams 28 and 29, respectively. The main insert 33 has contact portions 36 and 37 that come into contact with the slide cams 28 and 29 when they are raised by a predetermined distance, for example, 10 mm. The above-mentioned predetermined distance is set to be smaller than the predetermined distance that the protrusion pin 24 moves.

The fixed mold 22 described above includes another mold plate 38 that comes into contact with the mold plate 31 of the movable mold 21, and a main insert 39 that is held by this mold plate 38 and molds the upper side and the side part of the molded product 11. It comes from.

The slide cam 28 described above is erected parallel to the protrusion pin 24, has a long hole 41 formed in the lower portion in parallel with the moving direction of the protrusion plate 25, and has an undercut portion 12 in the upper portion.
A constricted portion 42 of FIG. 4 for molding the inner portions of a and 13a is formed, and a protrusion 43 is formed in the middle portion. This protrusion 43
The lower part contacts the upper surface of the pressing plate 35 at the original position of the slide cam 28, and the upper part contacts the contact part 36 when the slide cam 28 moves up by 10 mm. Other slide cams
29 is similarly configured.

A lower portion of the protrusion pin 24 is fixedly mounted on the protrusion plate 25 described above, and a cam bracket 45 for holding the connecting pin 44 inserted into the elongated hole 41 and another bracket 46 having the same structure. Is provided.

In this embodiment, when molding the molded article 11, the third
As shown in FIGS. (A) and (b), the cavity 23 is filled with molten resin and hardened with the movable die 21 closed with respect to the fixed die 22.

Next, when the molded product 11 is taken out, after opening the movable mold 21 with respect to the fixed mold 22, the protrusion plate 25 is moved in the forward direction, that is, as the upward movement of FIGS. 3 (a) and 3 (b) occurs. Then, the molded product 11 rises via the protrusion pin 24, and since the slide cams 28 and 29 are engaged with the protrusions 12 to 15 of the molded product 11, respectively, the slide cams 28 and 29 also rise.
At this time, the ejection plate 25 approaches the movable mold 21 against the return spring 27 and is guided by the movable mold 21 via the return pin 26. Then, as shown in FIGS. 5 (a) and 5 (b), when the ejecting plate 25 is raised by 10 mm, the slide cams 28 and 29 are also raised to abut the abutting portions 36 and 37, respectively. 28 and 29 stop.

After that, since the ejecting plate 25 tries to continue to move upward, the connecting pin 44 of the cam bracket 45 moves from the lower end side to the upper end side in the long hole 41 of the slide cam 28, and the connecting pin 44a of the other cam bracket 46. Moves in the long hole 41a of the slide cam 29 in the same manner, and the protrusion pin 24 further rises. Then, as shown in FIGS. 6 (a) and 6 (b), when the ejecting plate 25 further rises to 10 mm (20 mm in total), the slide cams 28 and 29 cause the protruding portions 12 to 15 to move as described above.
Although the molded product 11 is pushed up even though it is stopped in the state of engaging with, the projecting portions 12 to 15 are elastically deformed and disengage from the slide cams 28 and 29, respectively, and as a result,
The molded product 11 is removed from the movable mold 21. At this time, the connecting pin 44 described above is located near the upper end of the elongated hole 41 as shown in FIG. 6 (a), and the connecting pin 44a is also located near the upper end of the elongated hole 41a. There is.

Next, the return spring 27
6 is moved in the backward direction, that is, in the downward direction of FIGS. 6 (a) and 6 (b), the protruding pin 24 is returned to its original position, and the above-mentioned connecting pin 44 is connected to the upper end of the long hole 41 and the connecting pin.
After the 44a reach the upper ends of the long holes 41a, the slide cams 28, 29 are also returned to their original positions via the connecting pins 44, 44a, so that the mold can be closed.

In the embodiment configured in this way, the molded product 11 including the undercut parts 12a, 13a can be molded without the need for the slide core that moves in the direction orthogonal to the mold opening / closing direction. . Since the slide core is not required as described above, the protrusion 12 of the molded product 11
Walls 16, 17 and the like can be provided on the side of ~ 15 without any hindrance.

In this embodiment, a long hole 41 is formed in the slide cam 28, a cam bracket 45 for holding the connecting pin 44 is provided in the protruding plate 25, and a long hole 41a is formed in the slide cam 29 so that the protruding plate 25 is formed. A cam bracket 46 for holding the connecting pin 44a is provided, but instead of these, the protruding plate 25
To form a long hole parallel to the moving direction of the protruding plate 25,
Insert the connecting pin that is inserted into each long hole into the slide cam 2
It is possible to prepare for 8 and 29.

〔The invention's effect〕

Since the present invention is configured as described above, it is possible to mold a molded product having an undercut portion without requiring a slide core that moves in a direction orthogonal to the mold opening / closing direction. By the way, when designing a molded product, there are no restrictions such as the provision of a protrusion on the side part of the undercut part or the disposition of an ejector pin.
The degree of freedom in design can be increased.

[Brief description of the drawings]

1 to 6 are views for explaining one embodiment of the resin molding die of the present invention. FIG. 1 (a) is a perspective view of a molded product seen from the front side, and FIG. 1 (b) is FIG. 2 is a perspective view of the molded product viewed from the back side, FIG. 2 is a plan view of the molding die, and FIGS. 3 (a) and 3 (b).
Is a sectional view showing a state at the time of molding, FIG. 4 is an enlarged sectional view showing a state in which the slide cam engages with an undercut portion of the molded product, and FIGS. 5 (a) and 5 (b) show an operating body at a predetermined distance. Sectional view showing a state of being raised to the middle of FIG. 6 (a), (b)
Is a cross-sectional view showing a state where the actuating body is lifted to the moving end, FIG. 7 is a cross-sectional view showing a conventional example of a resin molding die, and FIG. 8 is a cross-sectional view taken along the line CC of FIG. . 11 …… Molded product, 12 ～ 15 …… Projection body, 12a ～ 15a …… Undercut part, 21 …… Movable mold, 22 …… Fixed mold, 23 ……
Cavity, 24 …… Extrusion pin, 25 …… Extrusion plate (actuator), 26 …… Return pin, 27 …… Return spring, 28,29 …… Slide cam, 36,37 …… Abutting part,
41, 41a ...... slot, 44, 44a ...... connecting pin, 45, 46 ...... cam bracket.

Claims (1)

(57) [Claims] 1. A movable mold and a fixed mold, a cavity formed on a joint surface of the movable mold and the fixed mold, and filled with a molten resin, and a movable mold provided relative to the movable mold. In a resin molding die having a protrusion pin for removing a molded product molded in the cavity from the movable mold and an actuating body for moving the protrusion pin by a predetermined distance, the resin is disposed in parallel with the protrusion pin. The movable die is provided with a slide cam for forming an undercut portion of the product, and an abutting portion that abuts when the slide cam moves a predetermined distance smaller than the predetermined distance. A long hole parallel to the moving direction of the actuating body is formed in one of the actuating bodies, and a connecting pin to be inserted into the long hole is provided in the other of the actuating bodies. Resin molding die, characterized in that the.