JPH0890615A - Injection molding die - Google Patents

Abstract

PURPOSE: To obtain an injection molding die for molding a satisfactory molded article free from a molding defect, such as sinkmark, by a method wherein a cooling pipe of a movable retainer plate is provided just below a sleeve pin to cool a mold rapidly and uniformly. CONSTITUTION: In an injection molding die consisting of a movable mold and a stationary mold, a movable retainer plate 2 having an L-shaped cross section is provided on the movable mold. A first movable insert 31 for forming a cavity is provided on the top of the movable retainer plate 2. A second movable insert 32 is provided in a space between the first movable insert 31 and the movable retainer plate 2 so as to abut on the movable retainer plate 2. Furthermore, a pushing mold 41 of an L-shaped cross section pushing a sleeve pin 6 is provided so as to be projected from an ejector plate 5 toward the first movable insert 31. The sleeve pin 6 and a pin insert 7 are respectively fitted into the pushing mold 41 and the second movable insert 32. A cooling pipe 8 of the movable retainer plate 2 is provided just below the sleeve pin 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection mold, and more particularly to an injection mold provided with a sleeve pin for extruding a molded product.

[0002]

2. Description of the Related Art Conventionally, a sleeve pin provided on a movable mold side for extruding a molded product and releasing it from a mold is usually a first protrusion plate provided between a movable mold plate and a movable mounting plate. And the second protrusion plate are provided so as to be fitted to each other (see JP-A-1-180315).

The injection molding die provided with the conventional sleeve pin will be specifically described below with reference to the drawings. In FIG. 3, the sleeve pin 100 is provided with a first protrusion plate 501 provided in contact with the outside of the movable side mold plate 300 of the injection molding die in which the fixed side mold plate 200 and the movable side mold plate 300 are provided. The fixing seat is fitted and fixed in the fitting hole of the first protrusion plate 501 of the second protrusion plate 502. In addition, the pin insert 6 is provided at the center of the sleeve pin 100.
00 is fixed to the movable mounting plate 400 and slidably inserted.

Reference numeral 700 denotes a cooling pipe provided on the movable side mold plate 300 in a direction intersecting with the sleeve pin 100. The cooling pipe 700 avoids collision with the sleeve pin 100.
The sleeve pin 100 is unavoidably sandwiched between the sleeve pin 100 and the sleeve pin 100, and the sleeve pin 100 is disposed at an escape position on both sides.

[0005]

However, in the injection molding die provided with the above-mentioned conventional sleeve pin, the sleeve pin 100 interferes with the sleeve pin 10.
Since the cooling pipe 700 cannot be arranged directly below 0, it is unavoidably arranged at a position avoided. Therefore, since the cooling pipe 700 does not pass through the portion where the sleeve pin 100 is present, cooling cannot be performed, or the cooling is insufficient, which requires a longer cooling time than necessary, resulting in poor productivity and uneven cooling. There is a problem that so-called sink marks are generated, which causes defective molding.

The present invention has been made in view of the above problems, and an object of the present invention is to solve these problems and to install a cooling pipe of a movable side mold plate in a sleeve pin. (EN) An injection-molding die which is provided directly below to cool a die rapidly and uniformly so that a good molded article free from molding defects such as sink marks can be obtained.

[0007]

In the injection mold of the present invention, in the injection mold comprising a movable mold and a fixed mold, the movable mold is provided with a movable side mold plate having an L-shaped cross section. , A first movable side insert forming a cavity on the tip side of the movable side mold plate, and a second movable side insert in the space between the first movable side insert and the movable side mold plate. An extrusion die of a sleeve pin having an L-shaped cross section is provided so as to abut the die plate, and the extrusion die is provided so as to protrude from the protruding plate toward the first movable side insert side. The sleeve pin and the second die are provided on the extrusion die. The movable side insert is fitted with the pin insert, and the cooling pipe of the movable side mold plate is provided directly below the sleeve pin.

[0008]

In the injection molding die of the present invention, the movable mold plate of the movable mold is provided with the second movable mold insert and the projecting plate is provided with the extrusion mold. The second movable mold insert and the extrusion mold are provided. Since the sleeve pin and the pin insert are fitted in the and, the cooling pipe of the movable side mold plate can be provided directly under the sleeve pin, and the mold can be cooled quickly and uniformly. Therefore, the occurrence of sink marks near the boss of the molded product due to insufficient cooling is prevented, and a good molded product without molding defects can be obtained.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an example of an injection molding die of the present invention. 2 is a view taken along the line AA of FIG. In FIG. 1, a cavity in which a molded product is molded is formed by a fixed-side mold plate 1 and a first movable-side insert 31 provided on the tip side of a movable-side mold plate 2 having an L-shaped cross section. The molded product 4 provided with the boss 4a is molded. A second movable side insert 32 is provided in a space formed between the first movable side insert 31 and the movable side mold plate 2 having an L-shaped cross section.

Further, an extrusion die 41 of a sleeve pin having an L-shaped cross section and a fixing plate 42 are fixed to the first projecting plate 5 by bolts so as to cover the second movable side insert 32 from above. It is provided. The sleeve pin 6 is fitted to the fixed plate 42 at the lower end of the fixed seat 6a from the back side of the fixed plate 42, and the fixed plate 4 is provided between the extrusion die 41 and the fixed plate 42.
It is fastened and fixed with bolts from the 2 side.

7 is a pin insert, and this pin insert 7 is
It is provided so as to penetrate through the central portion of the sleeve pin 6, and the tip of the sleeve pin 6 reaches the cavity surface forming the molded product 4. Further, the pin insert 7 is fixed by sandwiching the fixed seat 7 a at the lower end between the pin insert 7 and the movable mold plate 2 in a fitting hole provided in the second movable insert 32.

Reference numeral 8 denotes a cooling pipe. The cooling pipe 8 is provided on the movable side mold plate 2, and as shown in FIG. 2, is directly below the sleeve pin 6 and in a direction orthogonal to the sleeve pin 6. Has been drilled.

A second projecting plate 9 and a movable side mounting plate 10 are provided outside the first projecting plate 5 to which the extrusion die 41 is fixed, and the sleeve pin 6 is pushed out toward the cavity side when the die is opened. ing.

[Operation of Embodiment] When the molten resin is injected and filled into the cavity from the mold-closed state shown in FIG. 1 and cooling is completed, cooling is started. This cooling is performed by supplying cooling water to the cooling pipe 8 provided on the movable side mold plate 2. Therefore, starting from the movable side mold plate 2, the second movable side nest 3
2, the pin insert 7, the sleeve pin 6, etc. are also effectively cooled.

When this cooling is completed and the mold opening is started, the extrusion die 41 starts to operate, the sleeve pin 6 provided at the tip end of the extrusion die 41 moves forward to start extruding the molded product 4, and the first movable side. The molded product 4 is released from the insert 31.

Conventionally, as shown in FIG. 3, in the movable side mold plate 300 through which the sleeve pin 100 penetrates, the cooling pipe 700 could be arranged only at a position avoiding the sleeve pin 100. 1, a second movable-side insert 32 is newly provided on the tip side of the movable-side mold plate 2, and the pin insert 7 of the sleeve pin 6 is provided on the second movable-side insert 32. As shown in FIG. 2, the cooling pipe 8 can be provided directly below the sleeve pin 6 of the movable mold plate 2. Therefore, the mold can be cooled quickly and uniformly.

[0017]

In the injection molding die of the present invention, the movable movable mold plate of the movable mold is provided with the second movable mold insert, and the projecting plate is provided with the extrusion mold. Since the sleeve pin and the pin insert are fitted to the extrusion die, the cooling pipe of the movable side mold plate can be provided directly under the sleeve pin, and the die can be cooled quickly and uniformly. Therefore, the occurrence of sink marks in the vicinity of the boss of the molded product due to insufficient cooling is prevented, and a good molded product without molding defects can be obtained. Therefore, it is preferably used as an injection mold having a sleeve pin.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an injection molding die of the present invention.

FIG. 2 is a view on arrow AA of FIG.

FIG. 3 is a conventional injection mold provided with a sleeve pin.

[Explanation of symbols]

 1 Fixed-side mold plate 2 Movable-side mold plate 4 Molded product 4a Boss 5 First protruding plate 6 Sleeve pins 6a, 7a Fixed seat 7 Pin insertion 8 Cooling pipe 9 Second protruding plate 10 Movable-side mounting plate 31 First movable side Nesting 32 Second movable-side nesting 41 Extrusion type 42 Fixed plate

Claims (1)

[Claims] 1. An injection molding die comprising a movable die and a fixed die, wherein the movable die is provided with a movable side template having an L-shaped cross section, and a cavity is formed at a tip side of the movable side template. The first movable side insert and the second movable side insert are provided in contact with the movable side mold plate in a space between the first movable side insert and the movable side mold plate. An extrusion die of a die-shaped sleeve pin is provided so as to project from the projecting plate toward the first movable side insert side, and the sleeve pin is fitted to this extrusion die and the pin insert is attached to the second movable side insert. The mold for injection molding is characterized in that the cooling pipe of the movable side mold plate is provided directly below the sleeve pin.