JPH0453933Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mold used when molding a material for a tubular auxiliary nozzle used in an air injection loom by injection molding, powder molding, or the like.

[Conventional technology]

A large number of the above-mentioned auxiliary nozzles are arranged on the side of the weft insertion passage, and they sequentially blow the wefts ejected from the main nozzle into the weft insertion passage to insert the weft into the warp opening. It intrudes into the opening while pushing through the row, and in the latter stroke escapes below the row while sliding in contact with the warp threads.

As shown in FIG. 4, the auxiliary nozzle 1 has a tubular shape with its upper end closed, and its cross section is usually circular at the lower part, and the upper part is oval as shown in FIG. This makes it easy to separate and invade. Then, a nozzle hole 2 is bored in the above-mentioned closed upper end, and the pressurized air fed through the inner cavity 3 is jetted out from this nozzle hole in a predetermined direction at high speed.

On the other hand, as mentioned above, since the auxiliary nozzle intervenes in the warp row before and after the weft insertion process, its outer diameter should be made as small as possible, and the inner diameter must be dimensioned to reduce air resistance within the inner cavity 3. Sufficient capacity must be secured. As a result, the auxiliary nozzle 1 is formed into a tubular shape with a small diameter and a thin wall, and the short axis of the ellipse is, for example, an outer diameter D of 3 mm, an inner diameter d of 2 mm, and a wall thickness t of about 0.5 mm. However, if the nozzle holes 2 are drilled in such a thin-walled tubular body, variations will occur in the directivity of the ejected airflow.
A thick wall portion 4 is formed around this perforation site to increase the nozzle hole length. Therefore, the above-mentioned injection or powder molding is suitable for mass producing auxiliary nozzles having such a shape.

FIG. 6 shows an example of a conventional mold used for this molding. The mold 10 is a fixed lower mold 11
, an upper mold 13 that can be opened upwards with respect to the lower mold, and a side frame 16 that can be moved in and out from the side with respect to both of these molds, and has a mold surface on the lower mold 11 and the upper mold 13, respectively. 12 and 14 are carved to form a space corresponding to the outer shape of the auxiliary nozzle 1, and a pin-shaped core 17 corresponding to the inner cavity 3 of the nozzle is cantilevered with its base end 17a on the side frame 16. Support the mold surface 1
A molding space 18 is formed by disposing the molding parts between the molding parts 2 and 14. Gate 19 is placed in this molding space.
The auxiliary nozzle 1 is cast in a conventional manner by casting a heated and pressurized resin material through the auxiliary nozzle 1, or by blowing a powder material such as iron, nickel, or ceramics coated with a binder, or an appropriate mixture thereof together with high-pressure air. Form the rough profile. After releasing the rough shape material, or after releasing it and sintering it, the excess portion 5 (FIG. 4) is cut off, and the nozzle hole 2 is bored to form the auxiliary nozzle 1.

[Problem that the invention attempts to solve]

However, with such conventional molds, there has been a problem in that it is difficult to improve the product yield of the rough shaped material.

When the resin material or powder material is cast under high pressure, the elongated pin-shaped core supported on a cantilever cannot sufficiently resist the casting pressure, causing it to bend or vibrate. This is because, as a result, uneven thickness occurs in the product.

Note that when this uneven thickness occurs, a thinner part is formed on the nozzle tube wall, which is already thin, and at the same time, as mentioned above, the auxiliary nozzle Since a bending force is applied to the nozzle, bending stress concentrates on the thin wall portion, causing the nozzle to bend or break. When looms are required to operate continuously without stopping, as is the case these days, the occurrence of defects such as those described above is extremely undesirable, so the wall thickness is strictly checked.

Therefore, the problem of the present invention is to stably hold the pin-shaped core.

[Means for solving problems]

The means of the present invention that solves this problem is to form a chevron-shaped protrusion on at least one mold surface, which cuts across the molding space from this mold surface and can come into contact with or come close to the core. In addition, the corners of the periphery of the recess formed by this chevron-shaped protrusion are obtuse angles, so even if these corners appear on the surface, when the auxiliary nozzle comes into contact with the warp threads, the warp threads will be It won't hurt you.

[Effect]

According to this means, the pin-shaped core is not only supported at its proximal end in a cantilevered manner, but also supported by the protrusion at all times or during casting, so that the casting pressure acts on it. Harmful deflections and vibrations are also suppressed and the device is held stably.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The mold 20 is a pair of molds that can be opened from each other, for example, a fixed lower mold 21, an upper mold 23 that can be moved upward, and a side frame 26 that can move forward and backward from the sides of both molds, as shown in FIG. 6.
The lower die 21 and the upper die 23 are provided with die faces 22 and 24, respectively, which are symmetrical to the die mating faces 25 of the two dies.
When the auxiliary nozzle has the elliptical cross section, its major axis is aligned with the die mating surface 25. A pin-shaped core 27 corresponding to the inner cavity 3 of the auxiliary nozzle 1 is inserted into the nozzle.
The mold cavity 28 is formed by disposing the mold cavity 28 between the mold surfaces 22, 24 with its base end 27a supported by the side frame 26 in a cantilever manner.

Furthermore, the mold surface 22 is formed at the intermediate portion of the molding space 28
and protrusions 31 and 32 from 24, respectively. These protrusions 31 and 32 are arranged on one minor axis of the ellipse and have a mountain-shaped longitudinal section,
Each molding space 28 is cut horizontally, and the tip of each chevron is brought into contact with the core 27. Further, each protrusion is desirably formed as small as possible in consideration of strength; for example, the diameter of the base of the chevron is approximately 0.3 mm.

Therefore, the base end 27a of the core 27 is supported by the side frame 26, and the intermediate portion is supported by the protrusion 3.
1 and 32 from the short axis direction, that is, from the direction in which it is easy to bend, the heated and pressurized resin material is cast through the gate 29, or the powder material is blown in with high pressure air to cast the mold. Even if the core 27 tries to bend or vibrate when doing so, the protrusions 31 and 32 counteract and stop it. This prevents harmful uneven thickness from occurring in the product.

Once the molding is completed in this way, the side frame 26
is retracted to pull out the core 27, then the upper mold 23 is moved upward to open the mold, and the molded body is released to form the auxiliary nozzle 1 as described above. At this time, although holes remain in the positions relative to the protrusions 31 and 32,
Since these holes have small diameters and expand outward in accordance with the size and shape of the projections described above, they can be easily and completely closed by injecting an adhesive or the like into them. In addition, in the case of powder compacts, these pores shrink by approximately 20% during the subsequent sintering process, so if these pores are filled with the same type of powder material and sintered after the mold is released, a solid plug can be formed. I can do it. Furthermore, according to this embodiment, the corners of the periphery of the recess formed by the chevron-shaped protrusions have an obtuse angle, so even if this corner appears on the surface, the auxiliary nozzle will not connect to the warp. The warp threads will not be damaged during contact.

FIG. 3 shows another embodiment of the invention.

The molding die 40 of this embodiment is mainly intended for a rough-shaped material of a straight tube-shaped auxiliary nozzle that does not have the aforementioned elliptical cross section. The auxiliary nozzle is inserted into the guide when the weft entry passage is substantially closed by a row of flat guides having air guide holes formed therein. 3
Since the diameter of the auxiliary nozzle is limited to about mm, the inner and outer diameters of the auxiliary nozzle are further reduced than those described above.

In the mold 40, semicircular mold surfaces 42 and 44 are formed on the fixed lower mold 41 and the movable upper mold 43 from the mold mating surface 45, respectively, to form a space corresponding to the outer shape of the straight tubular auxiliary nozzle. A small-diameter pin-shaped core 47 with a circular cross section corresponding to the inner cavity of the auxiliary nozzle is arranged between the mold surfaces 42 and 44, and its base end is supported by the side frame 46 to form a molding space 48. . A protrusion 49 is made to protrude from the mold surface 44 and two protrusions 50 and 51 are made to protrude from the mold surface 42 at an intermediate portion of this molding space. These protrusions have a small-diameter chevron shape similar to the protrusions 31 and 32 (FIGS. 1 and 2), and their tops are close to the core 47 with a small gap δ in between. Then, the protrusion 49 is connected to a radius line OA perpendicular to the mold matching surface 45.
The tops of protrusions 50 and 51 are arranged on radius lines OB and OC that are equiangular with respect to this radius line, respectively, and the opposing side surfaces 50a and 51a of these protrusions are molded. It is oriented in a direction perpendicular to the mating surface 45.

Therefore, when casting, it is necessary to use a small diameter pin-shaped core 4.
Even if 7 tries to bend in a random direction, it will come into contact with one of the protrusions and this bending will be restricted, so the dimension of the gap δ should be adjusted so that harmful uneven thickness does not occur in the resulting molded product. This is done by setting the following.

The side surfaces 50a and 51a of the protrusions 50 and 51 are oriented as described above to enable release from the lower mold 41, but when the molded product is still soft at the time of release, such as a resin molded product, In this case, these protrusions can also be made symmetrical with respect to the radial lines OB and OC.

Furthermore, in each of the above embodiments, the protrusions are arranged in sets of two or three in the middle part of the molding space, but the important point is that the relationship between the molding space, the shape of the core, the position of the casting gate, etc. It is only necessary to arrange an appropriate number of protrusions at one or more parts that can most effectively suppress the deflection, vibration, etc. of the core under the following conditions:
Also, based on the above relationship, if the core is only deflected in one direction, the protrusion may be formed only on the mold surface on this side.

[Effect of idea]

As explained above, according to the present invention, it is possible to prevent the occurrence of harmful uneven thickness that would affect the strength of the auxiliary nozzle when molding the auxiliary nozzle material in the form of an elongated thin-walled tube. The retention is greatly improved. Furthermore, according to this embodiment, the corners of the periphery of the recess formed by the chevron-shaped protrusions have an obtuse angle, so even if this corner appears on the surface, the auxiliary nozzle will not connect to the warp. The warp threads will not be damaged during contact.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a main part of a mold according to an embodiment of the present invention, Fig. 2 is an enlarged cross-sectional view taken along the - line in Fig. 1, and Fig. 3 is a longitudinal cross-sectional view of a main part of a mold according to an embodiment of the present invention. A cross-sectional view of such a mold, FIG. 4 is a vertical cross-sectional view illustrating an auxiliary nozzle targeted by the present invention, and FIG.
FIG. 6 is an enlarged cross-sectional view taken along the line - in the figure, and FIG. 6 is a vertical cross-sectional view illustrating a conventional mold. 20,40...Mold, 21,41...Lower mold,
22, 42... Mold surface, 23, 43... Upper mold, 2
2,44...mold surface, 27,47...core, 28,
48...Molding space, 31, 32...Protrusion, 49,
50, 51...Protrusion.

Claims (1)

[Claims for Utility Model Registration] Pair molds 21, 23, 41, 43 that can be opened
Pin-shaped cores 27, 47 whose proximal ends are supported are placed between mold surfaces 22, 24, 42, 44 formed in
In the molds 20, 40 forming the cores 8, 48, at least one mold surface has chevron-shaped protrusions 31, 32, 49, 50, 51 that cut across the molding space from this mold surface and abut or are close to the core. A mold for forming an auxiliary nozzle on a loom.