JPH05104530A - Mold - Google Patents

Abstract

PURPOSE:To obtain a mold generating no unfilled part in a molded product even in continuous molding and easily removing generated flash. CONSTITUTION:In a mold having a fixed mold 1, a movable mold 2 and the knockout pin 6 incorporated as a part of the wall surface of the cavity 4 molding a molded product from the resin 3 injected n the space between the molds 1, 2 and allowing the molded product to protrude, the grooves 7 formed to the columnar knockout pin 6 from the wall surface end part of the cavity 4 have depressions 8 on the way thereof and the other ends of the grooves 7 are allowed to meet with the groove 9 going round the column of the knockout pin 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die for improving the filling property of a molded product.

[0002]

2. Description of the Related Art Heretofore, as a method for improving the filling property of a molded product, the knockout pin has been worked so as to remove volatile components generated from the air in the cavity and the molding material. FIG. 3 is a perspective view of a knockout pin of the conventional example. The knock-out pin 6 for ejecting the molded product from the mold is cut off into three surfaces from the tip portion, and the other end is the knock-out pin 6 communicating with the groove 9 that makes a circle. When this knockout pin is used, air in the cavity and volatile components generated from the molding material can be removed from the cut-off surface and the groove that goes around.

[0003]

However, when the molding is continued, the molding material is clogged in the air of the knockout pin or the portion where the volatile components generated from the molding material escape, and the movement of the knockout pin is hindered or the air after that is blocked. Moreover, there was a problem in that the volatile component could not escape and the molded product was not filled. Further, there is also a problem that the burr of the molding material generated in the groove that goes around the cut-off surface and the groove that goes around the cutting-off surface is integrated into a ring shape and cannot be easily removed.

Therefore, it is an object of the present invention to provide a molding die in which unfilling of a molded product does not occur even in continuous molding and the generated burr is easily removed.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is characterized in that a movable mold, a fixed mold, and a resin are injected between these molds for molding. In a knockout pin for projecting a molded product incorporated as a part of a cavity wall surface for molding a product, a groove formed along the pillar from the cavity wall surface end of the columnar knockout pin has a recess in the middle, A knockout pin formed so as to join the groove at the other end around a circle of a cylinder is provided.

[0006]

[Operation] Volatile components generated from the air in the cavity and the molding material pass through grooves, dents, grooves, and grooves that go around the circle from the top of the tip of the knockout pin that forms a part of the cavity wall. , Released outside the mold. Even if the molding material flows out with the air and the volatile components generated from the molding material, the groove formed along the column of the column from the top of the tip of the knockout pin is very small,
Blocked at the entrance. Even when the molding material flows through the groove formed along the cylinder, the molding material stays at a hollow in the middle. Therefore, burrs will be generated only in the grooves and dents along the cylinder, and the molding material will not flow into the grooves that go around the circle of the cylinder to form a ring-shaped burr. Being independent, it can be easily removed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings of the embodiments. The present invention is not limited to these examples.

FIG. 1 shows a molding for one embodiment of the present invention. FIG. 3 is a cross-sectional view of a knockout pin portion of the mold, in which a cavity 4 for molding a resin 3 into a plate shape by injecting a resin 3 is formed between the fixed mold 1 and the movable mold 2. A columnar knockout pin 6 is inserted into a through hole 5 formed in the movable mold 2 so as to form a part of the wall surface of the cavity 4. The through hole 5 and the knockout pin 6 inserted into the hole are finished with a dimensional difference that allows them to move in contact with each other. A groove 7 is formed along the pillar from the top of the tip of the columnar knockout pin 6, and the groove 7 has a recess 8 in the middle thereof. Furthermore, the other end of this groove 7 is a groove 9 that goes around a circular column.
Is formed so as to join. Therefore, the volatile components generated from the air and the molding material in the cavity 4 are discharged from the cavity 4 to the outside of the mold through the groove 7, the recess 8, the groove 7, and the groove 9 that surrounds the circle. . The exhaust hole 10 provided in the movable mold 2 facing the groove 9 that goes around the circle can be connected to an external depressurizing device to more efficiently process by depressurizing discharge. In this case, the knockout pin 6 is sealed by the O-ring 11 arranged on the movable mold 2. The knockout pin 6 may be arranged in the fixed mold in the opposite case.

The number, width, and length of the grooves 7 and the depressions 8 formed along the pillar are not particularly limited, and the material to be injected may form the depressions 8 depending on the viscosity of the molding material used, the curing speed, and the molding conditions. It can be set as appropriate under conditions that do not satisfy. Further, its shape can be appropriately selected and used such as a semicircular cross section, a V-shape, a U-shape. 2 is the MN of FIG.
It is a cross-sectional view, and eight grooves 7 having a semicircular cross section are formed along a cylinder. Further, the shape of the depression 8 provided in the middle of the groove is not particularly limited, and the shape of the quadrangle 8
An appropriate shape such as a, an elliptical shape 8 or a circular shape can be selected. Further, the shape of the groove 9 that goes around the circle is the same as the shape of the groove 7.

The knockout stroke is set to be equal to or larger than the distance between the top of the tip of the knockout pin 6 forming a part of the wall surface of the cavity 4 and the position where the groove 9 is formed around the circle which is the side surface of the cylinder of the knockout pin. Is preferred. After knocking out the molded product after molding by making a knockout stroke having such a dimensional relationship, the grooves 7, 9 and the recess 8 of the knockout pin are completely exposed from the arranged movable mold 2. It is extremely easy to remove the burrs that are formed in the series of grooves 7 and depressions 8 of the knockout pin, independently of each other by air or the like.

[0011]

EFFECTS OF THE INVENTION According to the present invention, the movement of the knockout pin is not obstructed even when molding is continuously performed, and the volatile components generated from the air and the molding material in the cavity are well escaped, and the cavity is sufficiently filled with the molding material. However, an unfilled molded product can be obtained, and burrs of the molding material generated on the knockout pin can be easily removed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a part of a molding die according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line MN in FIG.

FIG. 3 is a perspective view showing a tip apex of a knockout pin of a conventional example.

[Explanation of symbols]

 1 Fixed mold 2 Movable mold 3 Resin 4 Cavity 5 Through hole 6 Knockout pin 7, 9 Groove 8 Dimple

Claims (2)

[Claims] 1. Molding having a movable mold, a fixed mold, and a knockout pin for projecting a molded product incorporated as a part of a cavity wall surface where a resin is injected between these molds to mold the molded product. In the mold, the knockout pin is formed so that the groove formed along the column from the end of the cavity wall of the columnar knockout pin has a recess in the middle, and the other end merges with the groove that goes around the circle of the column. A molding die having a pin arranged therein. 2. A molding die, wherein a stroke of the knockout pin according to claim 1 is equal to or larger than a dimension of a cavity wall surface end portion of the knockout pin and a groove surrounding a circle of a cylinder.