JPS5829724B2 - Chip structure of extrusion die - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chip shape of an extrusion die for producing resin raw material pellets, and its purpose is to improve the abrasion resistance of the surface of the extrusion die and to improve the abrasion resistance of the die surface. The purpose is to maintain the chip strength of the die surface against a rotating cutter, and to provide an extrusion die with a nitrogen structure that is inexpensive and has good productivity.

In general, wear resistance is important for the surface of resin raw material pellet extrusion dies, and wear resistance is usually imparted by thermally spraying a hardening material onto the alloy surface that will become the cutter surface, but this is superior to surface hardening thermal spraying. It has been found that the life of the die is longer when a hard tip is attached, and the use of carbide tips is currently increasing.

When considering the chip shape, it is known that the chip strength increases when the hole and outer walls are as thick as possible.

However, increasing the wall thickness reduces the number of holes that can be buttoned within a defined space, resulting in a disadvantage that the productivity of raw material pellets is poor.

That is, as shown in FIG. 1, in an extrusion die device 2 for forming resin raw material pellets 1, a resin raw material 3 is force-fed in the direction of arrow A and poured out from a nozzle hole 5 formed in a die 4.

The raw material 3 poured out from the nozzle hole 5 is cut into predetermined particles by a predetermined rotary cutter 6 to form resin raw material pellets 1. As shown in FIG. A chip 7 made of wear-resistant material is attached by silver brazing or the like, and a predetermined nozzle hole 5 is bored.

The shapes of the carbide chips 7 in the conventional example attached to the surface of the die 4 are fan-shaped as shown in FIGS. 3 and 4, round chips as shown in FIG. 5, and as shown in FIGS. 6 and 7. Although there are rectangular chips, the conventional fan-like arrangement or base-like arrangement described above makes it easier to braze the chips to the die, but the number of holes drilled within a predetermined area is small, resulting in poor pellet productivity.

Although the number of holes can be effectively increased by arranging scraped round chips, it is difficult to braze, and the die button and processing costs increase.

Furthermore, if the square chip described above has the same number of holes as the round chip, the wall thickness between the holes will become narrower and the chip strength will decrease! There were some drawbacks, such as:

This invention improves the above-mentioned drawbacks, has a die chip structure that effectively arranges the number of nozzle holes within a predetermined area of the die, has good workability for brazing the die surface, and maintains sufficient chip strength. It provides:

Embodiments of the present invention will be described below with reference to FIGS. 8 to 9.
This will be explained in detail based on the following.

Chip 7 attached to the surface of die 4 of extrusion device 2
As is clear from the conventional example, it has been found that it is best to arrange the chips 7 in a triangular shape in order to maximize the nozzle hole 5.

Additionally, it has been found that a round chip is more effective in increasing the chip wall thickness in order to increase the strength of the chip 70.

In consideration of the above points, in the present invention, a regular hexagonal chip is formed, and the nozzle hole 5 is formed in the center thereof.

For this reason, within a predetermined area of the die 4, if the number of holes is the same as before, the chip wall thickness will increase, and if the chip wall thickness is the same, the number of nozzle holes 5 will increase, and the die 4 itself will also increase. Wall processing for adhering the chip 7 is no longer necessary, and processing costs are also reduced.

As described above, the regular hexagonal chip of the present invention has nozzle holes arranged without waste, has good bonding workability such as brazing, and has sufficient chip strength.
Productivity of resin raw material pellets is improved.

A-1 A comparison of the wall thickness of the chip according to the present invention with that of the conventional example is as shown in FIG.

When the pitch pb of the nozzle holes and the hole diameter d are the same, the chip wall thickness l is as follows for the conventional square chip, and for the square chip according to the present invention. For a square chip, -d ■=.

Therefore, the order of wall thickness l is regular hexagonal chip, round chip, and square chip, and the shape of the regular hexagonal chip is superior in terms of strength.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the extrusion die device, Fig. 2 is a front view of the die of the extrusion device, Figs. 3 and 4 are partial front views showing the arrangement of chips of a conventional fan-shaped die, and Fig. 5 The figure shows a conventional round chip arrangement, FIGS. 6 and 7 are a partial front view showing an arrangement of square chips, and FIG. 8 is a partial front view showing an arrangement of regular hexagonal chips according to an embodiment of the present invention. Figures 9A, 9A and 9C are comparison diagrams of wall thicknesses for each chip shape. 1... Raw material pellet, 2... Extrusion die device, 3... Resin raw material, 4... Dice, 5... Nozzle hole, 6... Cutter, 7... Chip, ■... Chip wall thickness, d... Nozzle hole diameter, p... Hole hit.

Claims (1)

[Claims] 1. A hard chip such as a cemented carbide nap is attached to the die surface of an extrusion die device for producing resin raw material pellets, and the chip shape is formed into a regular hexagon, and an extrusion nozzle hole is formed within a predetermined area of the die. The chip structure of the extrusion die is characterized by maintaining the number and chip strength in the best condition.