JPH04166313A - Mold for molding resin - Google Patents

Abstract

PURPOSE:To mold the molded object with under cut part, while a slide core in made unnecessary by a method in which the oval hole parallel to the moving direction of a working body is molded on either a slide cam or the working body, and a connecting pin to be inserted into the oval hole is provided on the other thereof. CONSTITUTION:When a molded object 11 is molded, a movable mold 21 is closed for a stationary mold 22, and the cavity 23 is filled with molten resin, and then the resin is cured. When the molded object is taken out, when an ejector plate 25 is raised, slide cams 28, 29 are also raised and is made to abut on parts 36, 37, and then it is stopped. Then, the connecting pins 44, 44a of cam bracket move the oval holes 41, 41a of the slide cams 28, 29 to upper end from lower end, and an ejector pin 24 is also raised further. When the ejector plate 25 is further raised, since a molded object 11 is pushed up in spite of the stop at the state where the slide cams 28, 29 engage with projected parts 12-15, the projected parts 12-15 are released from the slide cams 28, 29 with their elastic deformation, and the molded object 11 is taken out from the movable mold 21.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a resin molding die for producing a molded product by injecting a molten resin into a cavity of a predetermined shape and curing the resin, and particularly relates to a mold for producing 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 line CC in FIG. 7.

The molded article 1 shown in FIG. 7 has a pair of protrusions 2.3. The tips of these protruding parts 2.3 constitute undercut parts 2a and 3a formed in a direction perpendicular to the mold opening/closing direction, and are opposed to each other.

Conventionally, a resin molding die for molding such a molded product 1 is
A movable mold 4 and a fixed mold 5, a cavity 6 formed at the joint surface of these movable mold 4 and fixed mold 5 and filled with molten resin (not shown), and a side of the protrusion 2.3. It has a slide core 7 which is provided on one side and forms the inner part of the protrusion 2.3. This slide core 7 is
It is movable in a direction perpendicular to the mold opening/closing direction, for example, it moves to the right in Figure 8 as the mold opens and moves to the left in Figure 8 as the mold closes. It looks like this.

In this conventional resin molding die, when the movable die 4 is closed with respect to the fixed die 5 when molding the molded product 1, the slide core 7 moves to the left in FIG. As a result, a cavity 6 is formed by the movable mold 4, fixed mold 5, and slide core 7, and this cavity 6 is filled with molten resin and hardened. Next, when the movable mold 4 is opened relative to the fixed mold 5 when taking out the molded product 1, the slide core 7 moves to the right in FIG. 7 undercut parts 2a, 3
The engagement state with a is released. Thereafter, an ejector pin (not shown) ejects the molded product 1 into the movable mold 4.
exclude from

[Plot 111 to be solved by the invention By the way, in the above-mentioned conventional resin molding die, the protrusion 2
．． Since the movable part of the slide core 7 located on the side of the protrusion 2.3 needs to be kept flat, when designing the molded product 1, it is necessary to provide a protrusion on the side of the protrusion 2.3 or use an ejector pin. There were restrictions such as not being able to place a

The present invention has been made in view of the actual situation in the prior art, and its purpose is to provide an undercut portion without requiring a slide core that moves in a direction perpendicular to the mold opening/mold closing direction. An object of the present invention 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, and a movable mold and a fixed mold formed on the joint surfaces of the movable mold and the fixed mold and filled with molten resin. a cavity, an ejection pin that is movably provided in the movable mold and that removes a molded product molded in the cavity from the movable mold, and an actuator that moves the ejection pin by a predetermined distance. In a resin molding mold, a slide cam that is arranged parallel to the ejector pin and forms an undercut portion of the molded product, and a contact portion that comes into contact when the slide cam moves a predetermined distance smaller than the predetermined distance. is provided in the movable mold, and a long hole parallel to the moving direction of the working body is formed in either the slide cam or the working body, and the slide cam is inserted into the long hole in either one of the slide cam and the working body. The structure is equipped with a connecting pin.

[Function] Since the present invention is constructed as described above, after a molded product is molded with the movable mold closed with respect to the fixed mold and the mold is opened, the movable mold is ejected as the actuating body moves in the forward direction. As the molded product moves through the pin, the slide cam engages with the undercut of the molded product, so the slide cam also moves, and after that, when it has moved a predetermined distance, the corresponding The slide cam comes into contact with the contact portion and stops.

Next, since the actuating body attempts to continue moving further, the connecting pin provided on the other side moves within the elongated hole formed in either the actuating body or the slide cam along the moving direction of the actuating body. At the same time, the ejector pin also moves further. As a result, even though the slide cam is stopped as described above, the molded product is pressed by the ejector pin, so the undercut part of the molded product is elastically deformed and detached from the slide cam, causing the molded product to is removed from the movable mold.

Next, as the operating body moves in the backward direction, the ejector pin is returned to its original position, and the slide cam is also returned to its original position via the connecting pin, so that the mold can be closed.

As a result, a molded product having an undercut portion can be molded without requiring a slide core that moves in a direction perpendicular to the mold opening/closing direction.

[Example] Hereinafter, an example of the resin molding die of the present invention will be described based on the drawings.

1 to 6 are diagrams explaining one embodiment of the resin molding mold of the present invention, in which FIG. 1(a) is a perspective view of the molded product seen from the surface side, and FIG. 1(b) is a A perspective view of the molded product seen from the back side, Figure 2 is a plan view of the molding die, Figures 3 (a) and (b)
is a sectional view showing the state during molding, FIG. 4 is an enlarged sectional view showing the state in which the slide cam engages with the undercut part of the molded product, and FIGS. 5 (a) and (b) are 6(a) and (b) are cross-sectional views showing the state where it has risen to the middle of
FIG. 3 is a sectional view showing a state in which the actuating body has risen to the moving end. In addition, Fig. 3(a), Fig. 5(a) and Fig. 6(
a) is a cross-sectional view taken along line A-A in Figure 2, and Figures 3(b), 5(b), and 6(b) are cross-sectional views taken along line BB in Figure 2, respectively. It is a diagram.

The molded product 11 shown in the first EU (a) and (b) is made of synthetic resin and includes protrusions 12, 13, 14, and 15 on the back side. Among these protrusions 12 to 15, for example, each tip of a pair of protrusions 12.13 has an undercut portion 1 formed in a direction perpendicular to the mold opening/closing direction.
2a and 13a, which face each other. Similarly, each of the other protrusions 14 and 15 has an undercut portion 14a.
, 15a. A wall 16 is formed on the side of the protrusion 12.13, and a wall 17 is also formed on the side of the protrusion 14.15.

The resin molding mold of this embodiment for molding such a molded product l has a movable mold 21 as shown in FIGS. 3(a) and 3(b).
and a fixed mold 22, a cavity 23 formed at the joint surface of the movable mold 21 and the fixed mold 22, and filled with molten resin (not shown), and a cavity 23 provided movably in the movable mold 21. an ejector pin 2 for removing the molded product 11 molded in the cavity 23 from the movable mold 21;
4 and this ejecting pin 24 at a predetermined distance, for example, 20
An actuating body that moves by a certain amount, for example, an ejector plate 25, and a return pin 26 whose lower part is fixed to the ejector plate 25.
is inserted into this return pin 26, and the ejecting plate 25
and a return spring 27 that applies force to the movable mold 21 in a direction that separates them from each other, and a protrusion 12 of the molded product 11.
．． 13 and a similar sliding cam 29 shaping the inside of the other projection 14.15.

The above-mentioned movable mold 21 includes a mold plate 31 located above the ejecting plate 25 and into which the return pin 26 is inserted, a backing 32 provided on this mold plate 31, and a backing 32 provided on this backing 32 to perform molding. It includes a main insert 33 for molding the lower side of the product 11, and press plates 34 and 35 that are fastened onto the mold plate 31 and press down the slide cams 28 and 29, respectively. The main nest 33 has abutment portions 36,37 with which the slide cams 28,29 come into contact when the slide cams 28,29 are raised by a predetermined distance, for example 10 degrees. Note that the above predetermined distance is set smaller than the predetermined distance that the ejector 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 template 38 and molds the upper and side parts of the molded product 11. It consists of

The slide cam 28 described above is erected in parallel with the ejector pin 24, has a long hole 41 formed in its lower part parallel to the moving direction of the ejector plate 25, and has an upper part formed with the inner parts of the undercuts 12a and 13a. A constricted portion 42 shown in FIG. 4 is formed, and a protrusion 43 is formed in the intermediate portion. The lower part of this protrusion 43 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 is raised by 10 mm. Note that the other slide cams 29 are similarly configured.

The lower part of the ejector pin 24 is fixed to the ejector plate 25 described above, and a cam bracket 45 that holds the connecting pin 44 inserted into the elongated hole 41 and another bracket 46 configured similarly. is provided.

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

Next, when taking out the molded product 11, after opening the movable mold 21 with respect to the fixed mold 22, as the ejecting plate 25 moves in the forward direction, that is, in the upward direction in FIGS. 3(a) and 3(b), As the molded product 11 rises via the ejector pin 24, the slide cams 28,29 also rise, since the slide cams 28,29 are respectively engaged with the protrusions 12-15 of the molded product 11. At this time, the ejecting 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. As shown in FIGS. 5(a) and 5(b), when the ejector plate 25 rises by 10 mm, the slide cams 28 and 29 also rise and abut against the abutting portions 36 and 37, respectively. 28.29 will stop.

Thereafter, since the ejector plate 25 continues to rise, the connecting pin 44 of the cam bracket 45 moves from the lower end side to the upper end side within the elongated hole 41 of the slide cam 28, and the connecting pin 44a of the other cam bracket 46 moves from the lower end side to the upper end side. is slide cam 29
While similarly moving in the elongated hole 41a, the ejector pin 24 also rises further. And, Fig. 6(a),(b)
), the protrusion plate 25 extends further up to 10 strokes (
20 mm in total), the molded product 11 is pushed up even though the slide cams 28 and 29 are stopped in a state where they are engaged with the protrusions 12 to 15 as described above, so the protrusions 12 to 15 are raised. 15 are separated from the slide cams 28 and 29 while being elastically deformed, and as a result, the molded product 11 is removed from the movable mold 21. At this time, the above-mentioned connecting pin 44 is located near the upper end of the elongated hole 41, as shown in FIG. 6(a), and the connecting pin 44a is similarly located near the upper end of the elongated hole 41a. There is.

Next, the ejecting plate 2 is moved by the return spring 27.
5 moves in the return direction, that is, downward in FIGS. 6(a) and 6(b), the ejector pin 24 is returned to its original position, and the connecting pin 44 is placed at the upper end of the elongated hole 41, and the connecting pin After the slide cams 44a reach the upper ends of the elongated holes 41a, the slide cams 28 and 29 are also returned to their original positions via these connecting pins 44 and 44a, so that the mold can be closed.

In the embodiment configured in this way, a molded product 11 having undercut portions 12a, 13a, etc. can be molded without requiring a slide core that moves in a direction perpendicular to the mold opening/closing direction. . Furthermore, since a slide core is not required as described above, the wall portions 16, 17, etc. can be provided on the sides of the protrusions 12 to 15 of the molded product 11 without any problem.

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 ejecting plate 25, a elongated hole 41a is formed in the slide cam 29, and a elongated hole 41a is formed in the ejecting plate 25. The cam bracket 46 that holds the connecting pins 44a is provided, but instead of these, long holes are formed in the ejecting plate 25 parallel to the moving direction of the ejecting plate 25, and connecting pins are inserted into each elongated hole. can also be provided on the slide cams 28 and 29.

[Effects of the Invention] Since the present invention is configured as described above, a molded product having an undercut portion can be molded without requiring a slide core that moves in a direction perpendicular to the mold opening/closing direction. Therefore, when designing a molded product, there is no restriction such as not being able to provide a protrusion on the side part of the undercut or place an ejector pin, giving a greater degree of freedom in design. can do.

[Brief explanation of the drawing]

1 to 6 are diagrams explaining one embodiment of the resin molding mold of the present invention, in which FIG. 1(a) is a perspective view of the molded product seen from the surface side, and FIG. 1(b) is a A perspective view of the molded product seen from the back side, Figure 2 is a plan view of the molding die, Figures 3 (a) and (b)
is a sectional view showing the state during molding, FIG. 4 is an enlarged sectional view showing the state in which the slide cam engages with the undercut part of the molded product, and FIGS. 5 (a) and (b) are 6(a) and (b) are cross-sectional views showing the state where it has risen to the middle of
7 is a sectional view showing a conventional example of a resin molding die, and FIG. 8 is a sectional view taken along line C-C in FIG. 7. . 11...Molded product, 12-15...Protrusion body, 12a-15a...Undercut portion, 2
1...Movable mold, 22...Fixed mold, 23
...Cavity, 24...Ejection pin, 25...Ejection plate (operating body), 26...
...Return pin, 27...Return spring, 28.29...Slide cam, 36.37
...Abutment part, 41.41a...Elongated hole, 4
4.44a...Connecting pin, 45.46...
・Cam bracket. 1st page, 2nd figure, 3rd figure (G) 39 21: Kagemeki type 28,29 Varnish 7 nimu 22: Fixed gold g 36,37 'Touryuu Iku 23: Ki7goti 41,4ia
:+ Hole δ: Tsuchieshikura (actuating body) 4μ4c
:ren dt” so26: wataso jin 0 so
45. g: Kamuf” Fukechde/Return Suff 1 Wang. Figure 3 (b)

Claims (1)

[Claims] a movable mold and a fixed mold; a cavity formed at a joint surface of the movable mold and the fixed mold and filled with molten resin; and a cavity provided so as to be movable relative to the movable mold,
A resin molding mold having an ejector pin that removes the molded product molded in the cavity from the movable mold, and an actuator that moves the ejector pin by a predetermined distance,
A slide cam that is arranged parallel to the ejection pin and forms an undercut portion of the molded product, and a contact portion that comes into contact when the slide cam moves a predetermined distance smaller than the predetermined distance are attached to the movable mold. In addition, either the slide cam or the actuating body is provided with a long hole parallel to the moving direction of the actuating body, and either of the slide cam and the actuating body is provided with a connecting pin to be inserted into the long hole. A resin molding mold characterized by: