JPS6246335B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-color molding die that can produce a molded product in which resin is poured into the lower side of the primary molded product.

Conventionally, toy automobile tires have been manufactured by separately molding a wheel body and a tire, and manually fitting the tire into the wheel body. However, manufacturing using this method had the disadvantage that the tire easily came off the wheel body, and the process was inefficient and troublesome, resulting in high costs.

Therefore, a method of manufacturing tires by placing a pre-formed wheel body into a mold and pouring resin into the mold was considered, but this method still requires the work of putting the wheel body into a mold, which reduces productivity. The results were unsatisfactory in terms of cost reduction.

One possible method for molding such tires at once is to use a two-color molding machine. However, it is preferable to form a protrusion on the outer periphery of the wheel body to prevent the tire from coming off.
When two-color molding is performed using the usual method, there is a problem in that the resin does not get under the protrusions during secondary molding after primary molding. If you don't need to add a radius to the outer circumference of the tire, you can solve this problem by using a complicated split mold structure, but if you want to manufacture a tire with a radius around the outer circumference, you can simply create a split mold structure. It would have been impossible or extremely difficult to do so simply by devising ways to do so.

The inventor focused on this point and as a result of intensive research,
The nest fitted into the lower mold of the two-color molding mold,
We have discovered that by raising and lowering using a cam mechanism, it is possible to automatically and extremely easily mold products in two colors, such as toy car tires, which cannot be molded in two colors using conventional methods, and have arrived at the present invention. did.

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a sectional view of the two-color molding machine of the present invention with the mold attached, and FIG. 2 is a partially enlarged view of FIG. 1.

In the figure, numerals 1, 1' are the lower molds, 2,
2' is a nest fitted into the lower mold, and 3 and 4 are upper molds. And the lower mold 2, 2' is the upper mold 3.
and 4.

The upper molds 2, 2' have a cam plate 6,
side plate 5 for laterally moving 6';
5' is provided. When the upper mold is closed, this side plate moves downward, and the tapered portion formed at the lower end of the side plate pushes against the tapered portion of the cam plate, causing the cam plate to move laterally.

7 and 7' are driven plates, and the surface in contact with the cam plate has a concave and convex part similar to that of the cam plate, and when the convex part of the cam plate is located on the convex part of the driven plate, the driven plate nest will move upward. When the cam plate is pushed up and the convex portion of the cam plate is located in the concave portion of the driven plate, it returns to its original position.

Next, a method of molding a toy tire using the above-mentioned molding mold will be explained. After the mold clamping is completed, the upper mold 3, the lower mold 1, and the insert 2 fitted into the lower mold 1 are The primary molding material (ABS) is poured from the nozzle into the formed primary molding cavity 8.
Inject. After a certain period of time, the lower mold, with the primary molded product on it, rotates 180 degrees and retreats, moves to the secondary mold and fits into the upper mold. Next, upper mold 4
When closed, the side plate 5' fixed to the upper die 4
is lowered, the tapered portion at the lower end of the side plate pushes the tapered portion of the cam plate 6', and the cam plate 6' is moved to the left in FIG. When the convex part of the cam plate 6' and the convex part of the driven plate 7' come into contact with each other, the driven plate 7' is pushed upward, and as a result, the nest 2' is also pushed upward.
In this way, the primary molding material consisting of the wheel body 10 is lifted upward, and a gap is formed between the protrusion 9 on the outer circumference of the wheel and the lower die 1'. By injecting the material for secondary molding (synthetic rubber) from the nozzle into the cavity 11 for secondary molding formed in this way, the resin also enters the lower side of the wheel protrusion, as shown in Fig. 3. A tire 12 for a toy is obtained. Then, the lower mold 1' is moved back, the product is ejected, and then rotated 180 degrees. Before the cam plate rotates,
Although it protrudes to the left on the secondary side in FIG. 1, by rotating it becomes a state in which it protrudes to the right on the primary side in FIG. When the upper mold is closed, the side plate 5 pushes the cam plate 6 to the left in FIG. As a result, the driven plate 7 and the nest 2 are lowered. Thereafter, the above operations may be repeated in the same manner for molding. Although the above explanation has been made with respect to only one mold, when primary molding is performed with one mold, secondary molding is performed with the other mold. Therefore, one molded product is completed each time the mold rotates once.

The present invention introduces a cam mechanism that moves the nest up and down into a two-color mold, but the type of two-color mold is particularly limited as long as such a cam mechanism can be introduced. Not limited.

Further, the two-color molding mold of the above embodiment is the same as a normal two-color molding mold except that it includes a side plate, a cam plate, and a driven plate.

Incidentally, reference numerals 13, 13', and 14 in the figure are rounded portions provided on the upper mold and the lower mold, which are, of course, unnecessary if the rounded portion is not formed on the outer periphery of the molded product.

The molding mold of the present invention is applicable not only to the production of toy tires as shown in FIG. 3, but also as shown in FIGS.
This method is suitable for manufacturing a molded product in which resin is poured into the lower side of the primary molded product as shown in the figure.

The present invention is constructed as described above, and by the extremely simple operation of moving the nest up and down, molded products such as toy car tires, which were conventionally considered to be extremely difficult or impossible to mold all at once, can be produced. Since it is easy to manufacture, it has significantly improved the productivity of this type of molded product and made it possible to significantly reduce costs.In addition, the mechanism for moving the nest up and down of the present invention is extremely simple, making it easy to operate. In addition, there are fewer failures, and when manufacturing tires for toy vehicles, there are no problems with burrs or uneven thickness, and very precise molded products can be obtained. It also has many advantages such as being smooth.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
The figures are an enlarged view of the secondary molding mold shown in FIG. 1, FIG. 3 is a sectional view of a toy automobile tire molded using the molding mold of the present invention, and FIGS. 4 to 6 FIG. 2 is a cross-sectional view of another molded product molded using the mold of the present invention. In the figure, 1, 1'...lower mold, 2, 2'...nest,
3... Upper mold for primary molding, 4... Upper mold for secondary molding,
5, 5'... Side plate, 6, 6'... Cam plate, 7, 7'... Driven plate, 8... Cavity for primary molding, 11... Cavity for secondary molding,
12...Toy tires.

Claims (1)

[Claims] 1 One mold forms a primary molding cavity with an upper mold, a lower mold, and a vertically movable nest fitted into the lower mold, and the other mold has an upper mold, a lower mold, and a nest fitted into the lower mold. A cavity for secondary molding is formed by the insert and the primary molded product, and the lower die and the insert on the primary molded product side are moved to the cavity on the secondary molded product side with the primary molded product attached, and the secondary molding is performed. In a two-color mold that moves the product to the cavity on the primary molded product side after protruding, a side plate is provided on the upper mold, and the upper mold is closed and the side plate is removed. A cam plate that moves laterally when pushed by the side plate and a driven plate that moves up and down due to the movement of the cam plate are provided, and uneven portions are formed on each surface where the cam plate and the driven plate are in contact with each other. When the convex part of the cam plate and the convex part of the driven plate come into contact with each other, the driven plate and the nest connected to the driven plate are lifted up, and the convex part of the cam plate and the concave part of the driven plate come into contact with each other. A two-color molding die, characterized in that the driven plate and the nest connected to the driven plate are lowered.