JPS60193622A - Mold for two color molding - Google Patents

Abstract

PURPOSE:To contrive to achieve two color molding automatically by raising and lowering the core member fitted into the bottom force of a mold by a cam mechanism. CONSTITUTION:A bottom force is retracted, while carrying a primary product and rotating by 180 deg., and then is moved to the mold for secondary molding and is fitted to a top force. When the top force 4 is closed, a plate 5' is lowered, thereby pushing the tapering part of a cam plate 6' and moving it left. Consequently, the cam plate 6' is caused to be in contact with the projected part of a follower plate 7, and the follower plate and a core member 2' are pushed up, whereby a cavity is formed in between a projected portion 9 and the bottom force 1. Secondary molding material is injected into this cavity for secondary molding, and the product in which resin enters under side of the projected portion, is obtained. Next, the bottom force 1 is retracted, and it is turned by 180 deg. after a product has been pushed out, and then the top force is closed. Then, the side plate 5 pushes the cam plate 6 left, and the cam plate 6 is caused to be in contact with the recessed part of the follower plate 7, thereby lowering the follower plate 7 and the core member 2. The molding is achieved, repeating these operations automatically. The molded product which has been impossible to be molded by one time up to now, may be automatically produced by such simple operation raising and lowering the core member.

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 second 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, when manufactured using this method, there was a problem that the tire was easily detached from 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 all the protrusions on the outer periphery of the wheel body to prevent the tire from coming off, but if two-color molding is performed using the usual method, the lower part of this protrusion will There was a problem that the resin did not enter. If you don't need to add a radius to the outer circumference of the tire, you can solve this problem by creating a complex split-shaped structure, but if you want to manufacture a tire with a radius on the outer circumference, you can simply create a split-shaped structure. It was impossible or extremely difficult to do so simply by devising the mold structure.

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

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

FIG. 1 is a cross-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, 1.1' is a lower mold, 2.2' is a nest fitted into the lower mold, and 3 and 4 are upper molds. The lower molds 2, 2' are designed to be shared with both the upper molds 3 and 4.

The upper molds 2, 2' are provided with side plates 5.5' for laterally displacing the cam plates 6, 6'. When the upper mold is closed, this side plate is tilted downward, and the taper part formed at the lower end of the side plate fully presses the taper part of the cam plate, causing the cam plate to move laterally.

7.7' is a driven plate, and the surface in contact with the cam plate has an uneven 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 grate and the nest are pushed upward, and when the convex part of the cam plate is located in the recessed part of the driven plate, they are lowered to their original positions.

Next, to explain the method of molding a toy tire using the above-mentioned molding mold, when the mold clamping is completed, the upper mold 3, the lower mold l, and the insert 2 fitted into the lower mold 1 are A primary molding material (ABS) is injected from a nozzle into the formed cavity 8 for primary molding. After a certain period of time, the lower mold moves back while rotating 180 degrees with the primary molded product still on it.
It moves to the secondary molding mold and fits into the upper mold. Next, when the upper mold 4 is closed, the side plate 5' fixed to the upper mold 4 is lowered, and the tapered part of the lower end of the side plate is attached to the cam plate 6'.
Press the tapered part of the cam plate 6' to move it 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, the driven plate 7'
is pushed up, and as a result, the nest 2' is also pushed up. 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 for secondary molding formed in this way, the resin is also applied to the lower side of the wheel protrusion, as shown in Fig. 3. A filled toy tire 12 is obtained. Then, the lower mold 1' is moved back, and after ejecting the product, it is rotated 180°. Before rotation, the cam plate protrudes to the left on the forward side in Figure 1, but as it rotates, it protrudes to the right on the forward side in Figure 1. When the upper mold is closed, the side plate 5 pushes the cam plate 6 to the left in FIG. As a result, driven plate 7 and nest 2
and goes down. Thereafter, the above operations may be repeated in the same manner for molding. Although the above explanation was given only for 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 different from a normal two-color molding mold except for the provision of a side plate, a cam plate, and a driven plate.
Reference numeral 14 is a radiused portion provided on the upper mold and the lower mold, and is of course unnecessary if the radiused portion is not formed on the outer periphery of the molded product.

The molding mold of the present invention is not limited to manufacturing toy tires as shown in Fig. 3, but can also be used to pour resin into the T side of the next molded product as shown in Figs. 4 to 6. Suitable for producing molded products.

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 that were conventionally considered to be extremely difficult or impossible to mold all at once can be easily produced. Since it can be manufactured easily, 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 nested consonant up and down according to the present invention is extremely simple, so it is easy to operate and prevents failure. In addition, when manufacturing all tires for toy vehicles, there are no problems with cracking or uneven thickness, and very precise molded products can be obtained, so toy cars using these tires run smoothly. It has many advantages such as:

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of the present invention, Fig. 2 is an enlarged view of the secondary molding die shown in Fig. 1, and Fig. 3 is a cross-sectional view showing an embodiment of the molding die of the present invention. A sectional view of a molded toy automobile tire. FIGS. 4 to 6 are sectional views of other molded products molded using the mold of the present invention. In the figure, 1.1'...lower mold, 2.2'...nest, 3.-
Upper mold for blow molding, 4... Upper mold for secondary molding, 5.5'...
・Side plate, 6.6'...Cam plate, 7.7'
...driven plate, 8...-cavity for fire forming,
11...Cavity for secondary molding, 12...Toy tire representative Patent attorney Hitoyoshi Inagaki

Claims (3)

[Claims] (1) A two-color molding die characterized in that a cam mechanism for moving the nest up and down is disposed below the eight-fold nest fitted into the lower mold. (2) The cam mechanism includes a side plate provided on the upper mold, a cam grate that is pushed by the side plate and moves laterally when the upper mold is fully closed and the side plate is lowered, and the cam plate. 2. The two-color molding die according to claim 1, further comprising a driven plate that moves up and down according to the movement of the driven plate. (3) An uneven portion is formed on each contacting surface of the cam plate and the driven plate, and when the protruding portion of the cam plate and the protruding portion of the driven plate come into contact with each other, the driven plate is lifted up, and the protruding portion of the cam plate A two-color mold according to claim 1 or 2, which is lowered into the driven plate' by contacting the recessed portion of the driven plate.