JPS5921768B2 - mold for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding die used for plastic molding of synthetic resin products, and its purpose is to heat a molding material such as a synthetic resin material, When compressing and molding, we have created a mold that prevents as much as possible the molten molding material from flowing into the gaps between female mold blocks and between the female mold blocks and the base plate and hardening, resulting in thin burrs. This is what we provide.

Such thin burrs deteriorate the finished product of molded products such as synthetic resin products, and the removal work for this thin burr is extremely difficult to work with. Not only is a large number of molds required, but the positional deviation between the female mold blocks also causes the positional relationship with the male mold that fits into the female mold block to be distorted, resulting in dimensional fluctuations in the molded product and female mold blocks. The mold may be damaged due to collision between the block and the male mold, so eliminating thinning burrs is an important issue for molding molds and the products molded by the molding molds. becomes.

The results of the molding work show that even if there are no gaps between the female blocks a and the joint surfaces g, g, etc. between the female blocks a and a and between the female block a and the base plate b in Fig. 1, it is possible to use the mold for a long period of time. Thin burrs may appear later on the joint surfaces g, g, etc., and from this, the use of female blocks a, a and base plate b is caused by heating and compression of about 180°C during molding work. If there is a difference in expansion coefficient due to the difference in materials, the joint surfaces g, g,
A very small gap is created between the two, and as the molding material flows into this gap, a thin burr f is generated in the vertical direction, and between the female blocks A and a, and between the female block A and the base plate. It was found that this caused a misalignment between the molds b and the male mold e, which resulted in the mold being damaged.

By eliminating such thin longitudinal burrs f, the male die e and the base plate b are
This type of mold requires only a thin lateral burr f' at the abutting surface S between the two. The present invention has been made in view of the above considerations.

The mold for molding of the present invention will be described in detail below with reference to the drawings listed as examples. In FIGS. 2 and 3, reference numeral 1 denotes a base plate, and a recess 2 is provided on the surface. This base plate 1 is usually made of carbon steel or die steel for machine structures. 3 is a female block, which is formed according to the shape of the molded product and has a well-shaped recess 4.
will be established.

This depression 4 forms the outer surface of the molded product.
The female button 3 is made of, for example, sintered tungsten carbide powder or a superhard metal material whose main component is titanium carbide. This female type block 3 is made by combining a plurality of them as necessary, and forming the recess 2 of the base plate 1.
Bury and secure with an appropriate seal.

Reference numeral 5 denotes a joint surface, which is formed by joining the female blocks 3, 3.

6 is an embedded metal fitting, for example, the width is 4 to 5 [11]. It is formed into a square rod shape with a thickness of 2 to 3 [fins].

Then, it is buried across the joint surface 5, and is arranged at a slight distance H (for example, 1 to 2 squares) from the surface of the base plate 1 or the female blocks 3, 3. This embedded metal fitting 6 is not limited to the joint surface 5 of the female blocks 3, 3. Of course, it is also desirable to provide it on the joint surface 5' between the female block 3 and the base plate 1. The material used for this embedded metal fitting 6 may be the same as or different from that of the base plate 1 or the female type plate 3. Reference numeral 7 denotes a male block, and a protruding member Ta forming the inside of the molded product is fitted into the female block 3.

The male die 7 and the base plate 1 are mounted on a molding machine in the down position shown in FIG.

In the figure, a molding material is put into a female block 3 and a male die 7 is butted against each other and heated and compressed to obtain a molded product.
In this case, when the width dimension A of the depression 2 of the base plate 1 increases due to heating, the joint surfaces 5, 5 open between the female protrusions 3, 3 made of a cemented carbide metal material with a smaller expansion coefficient. A slight gap is formed.

Therefore, the molten molding material is the male mold 7 and the female mold block 3.
, 3 through the butting surface 8. The inflow of the molding material into the joint surfaces 5, 5 hardens and produces a thin burr in the vertical direction, but since the inflow of the molding material is blocked by the embedded metal fitting 6, the length of the thin burr is short and only the dimension of the distance H is formed. Become something. Then, when the molded product and the lateral thin burr of the abutting surface 8 are taken out, they are simultaneously released from the female mold block 3. As described above, according to the mold of the present invention, the female block 3 is embedded in the recess 2 provided in the base plate 1, and the male die 7 is fitted into the female block 3.
In a molding die in which a molding material is charged between the female block 3, the female block 3,
Embed the embedded fitting 6 across the joint surface 5 between 3 and 6.
By shortening the distance H from the abutting surface 8 of the male die 7 and the female die block 3 to the embedded metal fitting 6, the longitudinal thin burr can be made as short as possible, and the molded product and the abutting surface 8 can be made as short as possible. It is possible to suppress the lateral thinning that occurs in the mold to the extent that it can be released from the mold, and it is possible to eliminate damage to the mold and improve the quality of the molded product produced from the mold. .

[Brief explanation of drawings]

FIG. 1 is a sectional front view showing a conventional example of the present invention. Figures 2 and 3 show embodiments of the molding die of the present invention6.
FIG. 2 is a sectional front view, and FIG. 3 is a sectional front view of the set state in combination with the male mold. 1... Base plate 62...
... Recess in the base plate, 3 ... Female block 6
４・・・・・・Recess of female type block, ５・・・・・・
Joint surface, 6...Embedded metal fittings. 7...Male type.

Claims (1)

[Claims] 1. A molding die in which a female block is buried in a recess provided in a base plate, and a molding material is placed between the female block and a male die that fits into the female block, heated and compressed to obtain a molded product. The molding metal is characterized in that an embedding fitting is embedded across the joint surfaces between the female blocks, and the distance from the abutting surfaces of the male and female blocks to the embedding fitting is made shorter. Type.