JPS62167013A - Mold - Google Patents

Abstract

PURPOSE:To improve the workability at the removal of a molded part from molds by a structure wherein auxiliary grooves formed on one mold of a pair of the molds are made to be molded part holding grooves, the adhesion of which to the molded part is larger, while auxiliary grooves formed on the other mold are made to be molded parts earlier separating grooves, the adhesion force of which to the molded part is smaller. CONSTITUTION:The cross-sectional shape of an earlier separating groove 10 is of some part of a circle or nearly semicircular shape, while the area of the inner surface of a holding groove 9 is set larger than that of the inner surface of the earlier separating groove 10 or the cross-sectional shape of the holding groove is made into the shape of an inverted trapezoid. When molding material such as ring-shaped performed rubber or the like is charged in the cavity grooves 6 and 6 of the molds 1 and 2, which are constituted as mentioned above, and the molds 1 and 2 are heated under pressure, the molding material is first filled in the cavity grooves 6 and 6 and then flowed through film-shaped communicating passages 8 and 8 on the inner and outer peripheral sides of the cavity grooves 6 and 6 over the whole periphery at a time into the holding grooves 9 and 9 and the earlier separating grooves 10 and 10, when the pressure in the cavity grooves 6 and 6 reaches a predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mold for producing various molded products of rubber or plastic.

[Prior art and its problems] Conventionally, a preformed molding material such as rubber is charged between a pair of molds and pressurized, and the inside of a cavity groove etc. formed in each mold is pressed. When manufacturing various molded products by being fascinated by
For example, a molded product b... such as an O-ring is formed in both molds a,
It adhered to mold a in pieces, and there was no consistency as to which mold a it remained on. For this reason, there was a problem in that the workability of taking out the molded product from the molds a and a was poor, and the taking out work could not be automated. The cause of the above is the cross-sectional shape of the cavity grooves c and c provided in each mold a and a, and the cross-sectional shape of the sub-grooves (not shown) such as relief grooves attached to the binding section. are each mold a, a
Since these grooves and the above molded product b are symmetrical,
It can be mentioned that there is no difference in the adhesion force between the molds a and a.

An object of the present invention is to provide a molding die that solves the above problems.

[Means for solving problems]

The present invention comprises a pair of molds whose parting surfaces are mutually polymerizable and separable, and each of the parting surfaces has a cavity groove corresponding to the shape of the molded product and a secondary mold disposed in the vicinity of the groove. The groove is recessed, and further, the minor groove of one of the pair of molds is used as a molded product holding groove that has a strong adhesive force with the molded product, and the minor groove of the other mold is used as a molded product holding groove that has a large adhesion force with the molded product. It has grooves for early separation of molded parts with low adhesion force.

[Effect]

The adhesion force with the molded product in the molded product early separation groove is small, and the adhesion force with the molded product holding groove is large, so (even if the shape of the cavity groove is the same in a pair of molds) When the mold is opened, due to this difference in adhesion force,
It always adheres intensively to the latter side where the molded product holding groove is located.

〔Example〕

Embodiments of the present invention will be explained in detail based on the drawings.

In FIGS. 1 to 3, numerals 1 and 2 are a pair of upper and lower molds, which are arranged facing each other on a press mounting board and fixed thereto, and are moved toward and away from each other. 3 and 4 are parting surfaces of both molds 1.2, and cavity a6.6 corresponding to the shape of the molded product 5 such as an O-ring is recessed in the parting surfaces 3 and 4. .

. . . is a sub-groove, which is disposed along the entire circumference of the inner and outer circumferential sides of the vicinity of the cavity groove 6.6, via a film-like communicating path 8.8.

The above-mentioned sub-grooves 7... have different cross-sectional shapes for the upper and lower molds 1.2, and one mold has a stronger adhesion force with the molded product 5 compared to the molded product early separation groove 10 described later. However, a large molded product holding groove 9 and a molded product early separation groove 10 with a small adhesion force to other molds are formed, respectively. In the illustrated embodiment, the holding groove 9 is provided in the lower mold 2 and the early separation groove 10 is provided in the upper mold 1.

Therefore, while the cross-sectional shape of the early separation groove 10 is a part of a circle or a substantially semicircular shape, the area of the inner surface of the holding tj9 is larger than that of the inner surface of the early separation groove 10. In the embodiment, it is formed into an inverted trapezoid shape. By charging a preformed ring-shaped molding material such as rubber into the cavity grooves 6 and 6 of the molds 1 and 2 configured as described above, and heating the molds 1 and 2 under pressure. The molding material first fills the cavity grooves 6, 6, and when a certain pressure is reached, the molding material flows from the film-like communication passages 8.8 on the inner and outer circumferential sides of the cavity grooves 6, 6 to the holding grooves 9.9 and the entire circumference at once. into the early separation groove 10.10.

In order to take out the molded product 5 formed in this way from the mold 1.2, as shown in FIG. It remains on the lower mold 2 provided. In other words, if special shapes are excluded, the difference in adhesion between both grooves 9 and 10 and the molded product 5 is greater than the valley groove 9.
, 10 depends on the size of the inner surface area. Furthermore, since there is no difference in the shape of the cavity grooves 6, 6 of the two molds 1, 2, there is no difference in the adhesion force between the two molds 1, 2 and the molded product 5.

Therefore, the inner surface of the early separation groove 10 and the molded product 5 are relatively easily separated, so when the upper mold 1 is raised, outside air enters in the direction of arrow A, and first the early separation groove 10 Next, the vacuum between the inner surface of the communication passage 8 (on the upper mold side) and the inner surface of the cavity groove 6 (on the upper mold side) is broken, respectively.

Thus, the molded product 5 is not pulled upward any further and the vacuum state between it and the lower mold 2 is maintained, so that the molded product 5 is held in the lower mold 2. In addition, after taking out the
The portion of the molded product 5 closer to the end than the film-like communication path 8 can be easily torn off and removed. Since the cross-sectional shape of both grooves 9 and 10 may be such that there is a relative difference in the adhesion force with the molded product 5, it is preferable that the cross-sectional shape is as shown in FIG. 5 as another embodiment. . That is, in the figure, both grooves 9
, 10 have almost the same area, but the side wall portion 11 is formed in the holding groove 9 so as to be approximately perpendicular to the parting surface 4 or at an angle close to this. By increasing the side wall portion 11 in proportion to the total area of the inner surface of the retaining groove 9, the adhesive force with the molded product 5 can be increased, and this increases the resistance to separation of the molded product 5 and the retaining groove 9. It acts as force F.

Furthermore, as another example, the cross-sectional shape of the holding groove 9 can be changed to an inverted equilateral trapezoid, a rectangle, a part of an ellipse, and a circle, respectively, as shown in FIG. There is no problem with each shape of a part of. However, in FIG. 3, the diameter of the circular shape of the holding groove 9 is set to be sufficiently larger than that of the early separation groove 10 to increase the contact area and the adhesion force. Next, as shown in FIG. 3, the early separation groove 10 is also made to have a rectangular cross section, but its depth may be made shallow, and the other holding groove 9 may be made sufficiently deep.

FIG. 7 shows a case where the molded product 5 is a diaphragm, and the holding groove 9 and the early separation groove 10 having the same cross-sectional shape as in each of the above embodiments may be provided at predetermined positions of the mold 2.1, respectively. Similar effects can be achieved.

The embodiment shown in FIGS. 8 and 9 is applied to injection molding, and the molded product 5 to be manufactured is an O-ring, and a cavity groove 6 corresponding to the cross-sectional shape of the molded product 5 is formed. ，
6 are formed on each parting surface 3.4 of the upper and lower molds 1, 2, and a groove made of injected rubber or plastic is formed near the inner circumferential side of the cavity grooves 6, 6. Sub-groove 7 having a runner function as a passage for molding material
7 is formed. Regarding the sub-grooves 7, 7, the cross-sectional shapes of the early separation groove 10 provided in the upper mold 1 and the retaining groove 9 provided in the lower mold 2 were almost the same as those in the first embodiment. . In the figure, 12 is an injection nozzle, and 13 is a sprue following the injection nozzle, and the sprue 13 is connected to one location of the sub-groove 7 provided in the upper mold 1.

The molding material injected from the injection nozzle 12 flows through a film-like communication path 8 having a minute gap formed between the sub-grooves 7 and 7 on the entire inner circumferential side of the cavity grooves 6 and 6. The resistance is large, so it first spreads over the entire minor groove 7.
Thereafter, as the pressure increases, it simultaneously flows from the communication path 8 in the form of a film from all around the circumference and fills the cavity grooves 6, 6. By opening the upper and lower molds 1.2 after molding, the molded product 5 adhered to the lower mold 2, which is provided with the holding groove 9 that has a greater adhesion force to the molded product 5, as in the above embodiment. taken out in good condition.

By making the area of the inner surface of the molded product holding groove 9 larger than the area of the inner surface of the early separation groove 10 as described above, the holding groove 9 has a greater adhesive force with the molded product 5.

In addition, when the areas of the inner surfaces of both grooves 9 and 10 are approximately the same, the retaining groove 9 can be provided with a side wall 11 that is orthogonal to the parting surface 4 or close to this. The adhesion force can be relatively increased compared to that of the early separation groove 10.

The shapes of the holding grooves 9 and the early separation grooves 10 are not limited to a specific cross-sectional shape, etc., and the adhesion between the holding grooves 9 and the molded product 5 depends on the adhesion between the early separation grooves 10 and the molded product 5. Any shape may be used as long as it is relatively larger than the adhesion force.

〔Effect of the invention〕

In this way, in the present invention, when the mold 1.2 is opened after molding, the mold to which the molded product 5... remains attached can always be kept constant, and the molded product 5... can be kept constant. Workability when taking out from the mold 1.2 is improved.

Furthermore, since it is possible to leave all of the molded products 5 in the desired mold, automation of the work of taking out the molded products 5 is facilitated.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
FIG. 3 is an enlarged sectional view of the main part of FIG. 1, FIG. 4 is a sectional view explaining the operation, FIG. 5 is a sectional view of the main part showing another embodiment, The figure is a sectional view of a main part showing still another embodiment, FIG. 7 is a sectional view showing another embodiment, FIG. 8 is a sectional view showing still another embodiment, and FIG. 9 is an enlarged sectional view of the same main part. It is a diagram. FIG. 10 is a perspective view showing a conventional example. 1... Upper mold, 2... Lower mold, 3.4... Parting surface, 5... Molded product, 6... Groove for cavity,
7... Minor groove, 9... Molded product holding groove, 10... Molded product early bone Fa groove. Patent applicant: Dainichi Nippon Electric Cable Co., Ltd. Figure 7 Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] 1. Equipped with a pair of molds whose parting surfaces can be mutually polymerized and separated, and each of the parting surfaces has a cavity groove corresponding to the shape of the molded product and a sub-groove arranged in the vicinity of the groove. furthermore, the sub-groove of one of the pair of molds is a molded product holding groove that has a large adhesion force to the molded product;
A molding die characterized in that the other sub-groove is a molded product early separation groove with a small adhesion force to the molded product.