JPH0733033B2 - Injection mold - Google Patents

Description

TECHNICAL FIELD The present invention relates to an injection molding die provided with a cavity at a joint between a cavity plate and a core plate.

"Prior Art" Conventionally, as the above-mentioned injection mold, an injection mold 11 as shown in Fig. 4 is known. The injection molding die 11 includes a cavity plate 13 and a core plate 15 that are butted against each other, and a cavity 17 is formed at the butted portion of both plates, and the molded product formed in the cavity is ejected. A protruding pin 19 is provided for this purpose. In such an injection molding die 11, the cavity plate 13 is fixed to the fixed side mounting plate 21, and the core plate 15 is used.
Is fixedly mounted on the movable side mounting plate 23, and is clamped by the clamping force C by both mounting plates 21 and 23.

"Problems to be Solved by the Invention" By the way, in the case of the injection molding die 11 described above, only one molding product can be molded by one set of molds, and molding efficiency cannot be improved. There was a problem.

That is, during injection molding, a force F in the direction opposite to the mold clamping force C is applied to the cavity plate 13 and the core plate 15, and this force F is the product of the cross-sectional area of the cavity 17 and the injection pressure at the parting line Q. be equivalent to. Therefore, in the case where the cross-sectional area of the cavity 17 at the parting line Q is large, such as the injection molding die 11, the force F becomes extremely large and approaches the limit value of the mold clamping force C. For this reason, only one cavity can be provided per set of dies, and the molding efficiency cannot be improved.

"Means for Solving Problems" The present invention has been made to solve the above problems, and includes a parting line of a cavity formed in the shape of a flat plate, a cavity plate and a core plate. It is provided so as to be inclined with respect to the mold clamping direction. Further, according to the present invention, a parting line of a cavity formed in the shape of a flat plate is provided to be inclined with respect to a mold clamping direction between a cavity plate and a core plate, and a protrusion pin is provided on the core plate. It has been configured.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a diagram showing an injection molding die 31 according to the present invention, and is a half cross-sectional view passing through the central axis A thereof. The injection molding die 31 includes a fixed mold plate 33 fixed to the injection molding machine. A back plate 35 is fixed to the movable side of the fixed mold plate 33. The back plate 35 is provided with a through hole 37 whose diameter increases from the fixed side toward the movable side around the axis A.

Two cavity plates 39, 39 are provided on the inner surface of the through hole 37 at symmetrical positions with respect to the axis A.
It should be noted that two core plates, cavities, parting lines, protruding pin rods, cylinders, lid members, and the like, which will be described below, are also arranged at symmetrical positions with respect to the axis A, like the cavity plate 39. Inside the cavity plate 39, a core plate 41 is arranged so as to abut against the cavity plate 39.
A cavity 43 in the shape of a flat-plate molded product is formed at the abutting portion of the cavity plate 39 and the core plate 41, and a cavity is formed on the abutting surface of the cavity plate 39 and the core plate 41. A long line P is formed. The parting line P is arranged so as to be inclined with respect to the axis A so that the distance from the axis A increases from the fixed side toward the movable side.

A V-shaped core 45 is fixed to the core plate 41. The V-shaped core 45 is provided so as to penetrate into the back plate 35, and is formed to have a diameter that is hard to extend from the fixed side toward the movable side. The V-shaped core
A movable template 47 is fixed to the movable side of 45. The movable mold plate 47 is pressed toward the fixed mold plate 33 by a drive source provided in the injection molding machine and clamped.

On the other hand, a hole portion 33a penetrating from the fixed side to the movable side is provided in the central portion of the fixed mold plate 33, and an annular manifold mounting plate 49 is fixed to the fixed side of the hole portion 33a. There is. A locate ring 51 is provided on the fixed side of the inner peripheral portion of the manifold mounting plate 49. A nozzle touch 53 is provided on the movable side of the inner peripheral portion of the manifold mounting plate 49, and a manifold 55 is provided on the movable side of the nozzle touch 53 and the manifold mounting plate 49. A fixed receiving plate 57 is provided on the movable side of the manifold 55, and the outer peripheral portion of the fixed receiving plate 57 is in contact with the cavity plate 39. Then, the locate ring 51, the manifold mounting plate 49, the nozzle touch 53, and the manifold 55 have a molten resin injection path 59 formed therethrough, and a gate 61 communicating with the cavity 43 is formed at the tip thereof. Is provided. Then, the molten resin is injected into the cavity 43 through the resin injection path 59.

Further, the core plate 41 is provided with a protruding pin rod (projecting pin) 63. The protruding pin rod 63 includes a protruding portion 65 having a small diameter and a piston portion 67 having a large diameter. The protruding portion 65 is disposed so as to penetrate the core plate 41 with its tip end surface facing the cavity 43. Further, the V-shaped core 45 is provided with a cylinder portion 69 which is fitted in the piston portion 67 in a liquid-tight state. Further, the protruding portion is provided on the cavity 43 side of the cylinder portion 69.
A lid member 71 that fits in a liquid-tight state with the 65 is provided. The lid member 71 constitutes a cylinder together with the cylinder portion 69, and by engaging with the large-diameter piston portion 67, the protrusion pin rod 63 is prevented from protruding beyond a predetermined protrusion stroke.

Next, the operation and action of such an injection molding die 31 will be described with reference to FIGS. 1 to 3.

First, referring to FIG. 1, the cavity of the injection molding die 31.
Molten resin is injected into the nozzle 43 from the nozzle touch 53 through the injection path 59 to perform molding. At this time, a force X equal to the product of the sectional area of the cavity 43 on the parting line P and the injection pressure acts on the cavity plate 39 and the core plate 41 perpendicularly to the section on the parting line P. However, in this injection molding die 31,
The parting line P is arranged not at right angles to the axis A, which is the mold clamping direction, but at an angle. Therefore, since the force X acts with an inclination with respect to the axis A, the component Y of the force X in the direction of the axis A can be made smaller than the force X, and the mold clamping force required for each cavity Can be reduced. Therefore, it is possible to improve the molding efficiency by providing two cavities in one mold.

Next, when the resin in the cavity 43 is solidified, the mold is opened as shown in FIG.

Then, as shown in FIG. 3, hydraulic oil is injected into the space in the cylinder portion 69 opposite to the core plate 41 of the piston portion 67. This allows the protruding pin rod
63 is projected and the molded product M is released. At this time,
The amount of protrusion of the protruding pin rod 63 is restricted by the piston portion 67 coming into contact with the lid member 71.

As described above, in the injection molding die 31, the cross section of the cavity 43 in the shape of a flat plate molded product at the parting line P is inclined with respect to the axis A which is the mold clamping direction. Since it is provided, the force applied during injection molding can be inclined with respect to the mold clamping direction, and the mold clamping force required for each cavity can be reduced. Therefore, two cavities can be formed in one set of dies, and the molding efficiency can be improved. Further, since the cavities 43 are arranged symmetrically with respect to the axis A, the components Z of the force F applied during injection molding in the direction perpendicular to the axis A can be balanced with each other. Further, since the protruding pin rod 63 is provided on the core plate 41, the molded product M can be easily released from the mold.

In the above embodiment, two cavity plates, core plates, cavities, protruding pin rods, etc. are provided at symmetrical positions with respect to the axis A. However, the invention is not limited to this. Alternatively, they may be provided at equal intervals in the circumferential direction.

"Effects of the Invention" As described above, according to the present invention, the parting line of the cavity having the shape of a flat plate-shaped molded product
Since the cavity plate and the core plate are provided so as to be inclined with respect to the mold clamping direction, it is possible to reduce the force applied in the mold clamping direction. Therefore, a large number of cavities are formed in one mold, and at the same time a large number of cavities are formed. The effect that a molded product can be molded is obtained. Further, according to the present invention, the parting line of the cavity having the shape of a flat plate-shaped molded article is provided so as to be inclined with respect to the mold clamping direction of the cavity plate and the core plate, and the protruding pin is provided on the core plate. Since the above is provided, the same effect as described above can be obtained, and an effect that the molded product can be easily released from the mold is obtained.

[Brief description of drawings]

1 to 3 are views showing an embodiment of the present invention, in which FIG. 1 is a sectional view showing a state at the time of molding, FIG. 2 is a sectional view showing a state in which a mold is opened, FIG. FIG. 3 is a sectional view showing a state where a molded product is released from the mold, and FIG. 4 is a sectional view showing an example of a conventional injection molding die. 31 …… Injection mold, 39 …… Cavity plate, 41
…… Core plate, 43 …… Cavity, P …… Parting line, 63 …… Extrusion pin rod (extrusion pin).

Claims (2)

[Claims] 1. A cavity having the shape of a flat plate molded product to be molded at a joint between a cavity plate and a core plate is formed, and a parting line of the cavity is formed by the cavity plate and the core plate. An injection molding die, which is provided so as to be inclined with respect to the die clamping direction. 2. A cavity formed in the shape of a flat plate-like molded product to be molded at the joint between the cavity plate and the core plate is formed, and the parting line of the cavity is defined by the cavity plate and the core plate. An injection mold, wherein the core plate is provided with an ejecting pin while being inclined with respect to the mold clamping direction.