JPH0635137B2 - Direct pressure burrless mold - Google Patents

Description

TECHNICAL FIELD The present invention relates to a direct pressure burrless mold. More specifically, the present invention relates to a direct pressure burrless mold capable of producing a resin molded product by direct pressure molding without generating burrs in the opening.

(Prior Art) Conventionally, an injection molding method has been basically used to manufacture a resin molded product such as a thermosetting resin having an opening.

However, not all resin molded products can be manufactured by this injection molding method. For example, if the desired quality cannot be obtained by the injection molding method, or the resin can be molded by the injection molding method. In the case of the material, for example, a direct pressure molding method is used in which a resin material such as a thermosetting resin is pressure-molded by a vertically divided mold as shown in FIG.

For example, when a resin molded product having an opening is manufactured by this direct pressure molding method, (a) first, at a predetermined position on the bottom of the lower mold (a),
An insert mold (a) is arranged, and a resin tablet (d) is supplied between the lower mold (a) and the upper mold (c).

(B) Next, the lower die (a) is moved upward and the upper die (c) is moved downward, and the tablet (d) is clamped and cured.

(C) After curing, the molded product (e) is taken out from the lower and upper molds (a) and (c).

(Problems to be Solved by the Invention) However, when the conventional direct pressure molding die as illustrated in FIG. 6 is used, burrs are formed on the upper surface of the opening (f) of the molded product (e). There was a drawback that the occurrence of (g) was unavoidable. Therefore, it was necessary to remove the burr from the opening after the direct pressure molding. This burr removal work is troublesome and time-consuming, and in addition, this causes a large amount of finishing cost for the molded product, resulting in a high manufacturing cost.

The present invention has been made in view of the above circumstances, solves the drawbacks of the conventional direct pressure molding die, and manufactures a molded product having an opening by direct pressure molding without generating burrs. The purpose of the present invention is to provide a new direct pressure burrless die that can be used.

(Means for Solving the Problems) As a solution to the above problems, the present invention is directed to at least a vertically divided direct pressure molding die, in which a pin facing an insert die arranged at the bottom of a lower die is provided. Provided is a direct pressure burrless mold, which is arranged in an upper mold so as to be vertically movable via a driving means.

(Operation) In the direct pressure burrless mold of the present invention, at least the pin facing the insert mold arranged at the bottom of the lower mold of the mold divided into upper and lower parts can be vertically moved to the upper mold through the driving means. By arranging the pin, the molten resin material can be prevented from invading the insert mold by this pin, or the infiltrated material can be eliminated. Therefore, it is possible to prevent the occurrence of burrs in the upper part of the opening, which is inevitable in the past.

(Example) Hereinafter, an example is shown according to drawings and the direct pressure burrless metallic mold of the present invention is explained still in detail.

FIG. 1 is a sectional view showing an embodiment of a direct pressure burrless die of the present invention.

The direct pressure burrless mold shown in FIG. 1 is divided into, for example, four molds (1), (2), (3) and (4) which are vertically and horizontally divided.
It is composed by. The upper die (1) can move up and down with respect to the left and right dies (3) and (4) moving in the left-right direction. Needless to say, the mold of the present invention is not limited to the divided structure illustrated in FIG. 1 and may have any structure.

At the center of the lower mold (2), a support rod (6) for placing the insert mold (5) and two take-out rods (7) for taking out the molded product from the lower mold (2). ) Is provided. The support rod (6) and the take-out rod (7) are vertically movable. The insert mold (5) automatically feeds the support rod (6) when manufacturing a molded product.

On the other hand, at the center of the upper mold (1), a pin (8) facing the insert mold (5) arranged in the lower mold (2) can be moved up and down via a spring (9) as a driving means. It is installed in. The drive means for supporting the pin (8) is not limited to this spring (9), and may be any suitable one such as a hydraulic cylinder or an air cylinder.

For example, when manufacturing a resin molded product having an opening using the direct pressure burrless mold of the present invention having the above structure, first, as shown in FIG. 2, the insert mold (5) and the molding resin material are used. The tablet (10) is automatically supplied to a predetermined position of the lower mold (2). Then
As shown in FIG. 3, the upper mold (1) and the left and right molds (3) and (4) are moved in the direction of the arrow shown in the drawing to move the upper and lower molds (1) ) (2) (3) (4) start the mold clamping of the tablet (10). At this time, the pin (8) is arranged on the upper surface of the insert mold (5) and rises, contrary to the lowering of the upper mold (1). As a result, the pin (8) and the insert mold (5) are in close contact with each other, so that the molding resin material can be prevented from entering the insert mold (5) or the invading material can be eliminated.
For this reason, it is possible to prevent the occurrence of burrs in the openings of the molded product, which conventionally cannot be avoided after molding.

After this, as shown in FIG. 4, the mold clamping is completed and the tablet (10) is cured. After curing, as shown in FIG. 5, the upper mold (1) and the left and right molds (3)
(4) and should be opened in the upper and left and right directions. At this time, the pin (8) is pushed back downward by the elastic force of the spring (9). Next, the support rod (6) and the take-out rod (7) are raised, and the molded product (11) is removed from the lower mold (2). After this, the molded product (11) is automatically transferred from the mold.

In this way, a resin molded product having an opening can be manufactured by direct pressure molding without generating burrs. The finishing process for removing burrs, which is conventionally required, can be omitted, and the manufacturing cost of the molded product can be reduced. Further, even in the case of a resin material that can be manufactured only by direct pressure molding, insert molding can be easily performed. Furthermore, insert molding by direct pressure molding can be performed on a molded product having a complicated shape such as a spline, a screw, and the like, which requires precision. For example, the direct pressure burrsless mold of the present invention also facilitates the manufacture of pulleys, sealing plates, and the like.

Of course, the present invention is not limited to the above examples. It is needless to say that various aspects are possible in details such as shapes, structures and configurations of molds and insert molds of upper, lower, left and right parts, types of driving means, structures and configurations, types of resin materials and the like.

(Effects of the Invention) As described in detail above, according to the present invention, a direct pressure molding die capable of preventing the occurrence of burrs in the opening is provided. Even in the case of a resin material that can be molded only by direct pressure molding, or in the case of a molded product having a complicated shape and requiring high accuracy, insert molding can be easily performed.
Further, the finishing process of the molded product is not required, and the manufacturing cost of the molded product becomes low.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a direct pressure burrless die of the present invention. 2, 3, 4, and 5 are process cross-sectional views showing a method for manufacturing a resin molded product using the direct pressure burrless mold illustrated in FIG. 1, respectively. FIG. 6 is a process sectional view showing a conventional direct pressure molding method. 1 …… Upper mold 2 …… Lower mold 3,4 …… Left and right mold 5 …… Insert mold 6 …… Support rod 7 …… Ejecting rod 8 …… Pin 9 …… Spring 10 …… Tablet 11… …Molding

Claims (2)

[Claims] 1. A direct pressure molding die which is at least divided into upper and lower parts, wherein a pin facing an insert mold arranged at a bottom portion of a lower mold is vertically movably arranged in an upper mold through a driving means. Direct pressure burrless mold which is characterized by 2. The direct pressure burrless mold according to claim 1, wherein the driving means is a spring, a hydraulic cylinder, or an air cylinder.