JPH0664829U - Hot nozzle for runnerless injection molding - Google Patents

Abstract

(57) [Abstract] [Purpose] Even if the wear of the outlet 9 of the nozzle portion 1B progresses, the outlet 9 is repaired by a simple means of exchanging the tip 11 constituting the outlet 9. The repair workability is greatly improved, and dumping of the hot nozzle 1 is avoided, which is economically advantageous. [Structure] An outlet 9 of a nozzle portion 1B of a hot nozzle 1 is composed of a tip 11 which is detachably attached.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hot nozzle for runnerless injection molding.

[0002]

[Prior art]

 Conventionally, as a hot nozzle for runnerless injection molding, one described in Japanese Examined Patent Publication No. 1-59895 is known. According to this type of hot nozzle, the structure can be simplified compared to the internal heating method in which a heater is built in the nozzle and the external heating method in which a band heater is attached to the outer circumference of the nozzle. By forming the part with a thin wall, the heat capacity is reduced, the temperature rise and fall time due to energization and de-energization is shortened, responsiveness is improved to facilitate temperature control, and thermal decomposition of resin due to excessive heating It has various advantages that it is possible to prevent the occurrence of inconveniences, such as the retention of the resin in the nozzle portion due to the thermal decomposition and the color mixture at the time of color change due to the retention.

By the way, in the case of performing injection molding using the conventional hot runnerless injection molding nozzle, no problem occurs in injection molding of only molten resin, but for example, a hard material such as glass fiber, mica, or fine metal powder. When a composite material of resin and resin is injection-molded, the outlet of the hot nozzle is worn in a relatively short period of time, which hinders proper molding. Therefore, if the wear of the outlet progresses, the outlet must be repaired by welding or thermal spraying, such as build-up and grinding. However, in order to restore the caliber with a finishing accuracy within the allowable tolerance, skilled and sophisticated technology is required, and the work itself is extremely complicated, resulting in poor workability. For this reason, there is an economical inconvenience of abandoning repair work and discarding hot nozzles.

[0004]

[Problems to be solved by the device]

 The problem to be solved is that if wear at the outlet of the hot nozzle progresses, troublesome repair work such as overlaying or grinding by welding or thermal spraying must be performed, or abandon the repair work. The point is that hot nozzles must be discarded.

[0005]

[Means for Solving the Problems]

 The present invention has a nozzle portion that is inserted into a nozzle hole formed in communication with the cavity of a resin molding die, and a base portion that guides molten resin injected from a nozzle of an injection molding machine into the nozzle portion. In a runnerless injection molding hot nozzle in which at least a portion of the nozzle portion and the base portion corresponding to the nozzle portion is formed of a conductive metal having a predetermined electric resistance, the outlet of the nozzle portion is detachably attached. Even if the outlet of the nozzle part is worn out, the outlet can be repaired by a simple means of exchanging the tip forming the outlet, greatly improving the repair workability. In addition to the above, the objective of ensuring economic advantage was achieved by avoiding the dumping of hot nozzles.

[0006]

[Action]

 According to the present invention, even if the wear of the outlet progresses, it can be easily repaired by exchanging the tip by a simple attachment / detachment work.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic vertical cross-sectional view of the present invention, and FIG. 2 is an enlarged vertical cross-sectional view of a main part. In these drawings, a hot nozzle 1 is a base integrally formed of a conductive metal having a predetermined electric resistance. 1A and a tapered nozzle portion 1B. The base portion 1A receives the molten resin P injected from a nozzle of an injection molding machine (not shown), and is locked to a manifold 2 by a fixing member 4 fixed via a bolt 3 and the nozzle portion 1B. Is inserted into the nozzle hole 6 formed in the cavity core 5 of the mold. A molten resin passage 7 is provided inside the hot nozzle 1. The inlet of the passage 7 communicates with a resin distribution passage 8 in the manifold 2, and an outlet 9 of the passage 7, that is, an outlet 9 of the nozzle portion 1B. Communicates with the cavities 10.

The outlet 9 of the nozzle portion 1B is composed of a tip 11 detachably attached to the nozzle portion 1B by press fitting. The tip 11 has a frustoconical cylindrical cross section and is formed of a material having excellent wear resistance, for example, carbon steel, high speed steel or other superhard metal that has been heat treated such as quenching. . In the figure, reference numeral 12 represents a conducting wire.

As described above, since the outlet 9 of the nozzle portion 1B is constituted by the tip 11 having excellent wear resistance, not only during injection molding of only the molten resin, but also for example, glass fiber, mica or fine metal powder. Even when a composite material such as a hard material and a resin is injection-molded, the wear of the outlet 9 can be reduced. Moreover, even if the outlet 9 is worn out, the tip 11 can be removed by replacing the tip 11 by removing the tip 11 and press-fitting a new tip 11 into it. In other words, it is possible to easily perform repairs without requiring highly sophisticated techniques, such as complicated repair work such as welding or thermal spraying, which has been conventionally performed on the worn outlet 9, such as build-up and grinding. You can Therefore, the repair workability is greatly improved, and the economical inconvenience of giving up the repair work and discarding the hot nozzle 1 cannot occur.

In the above-described embodiment, the tip 11 is press-fitted and attached to the nozzle portion 1B, but the mounting means of the tip 11 is not limited to press-fitting, and it is possible to tighten with a screw or the like. Other attachment means may be used. In short, all removable attachment means can be adopted. Further, the metal material forming the chip 11 is not necessarily required to have wear resistance. That is, the tip 11 may be formed of a metal material having slightly lower wear resistance. However, by using the tip 11 having excellent wear resistance, the wear can be reduced, and therefore, there is an effect that the replacement frequency of the tip 11 can be reduced.

[0011]

[Effect of device]

 As described above, according to the present invention, even if the wear of the outlet progresses, it can be easily repaired by exchanging the tip by a simple detaching operation. Therefore, the repair workability is greatly improved, and the economical inconvenience of abandoning the repair work and discarding the hot nozzle cannot occur.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part.

[Explanation of symbols]

 1 Hot Nozzle 1A Base of Hot Nozzle 1B Nozzle of Hot Nozzle 6 Nozzle Hole 9 Outlet of Nozzle 10 Cavity 11 Chip P Molten Resin

Claims (1)

[Scope of utility model registration request] 1. A nozzle part which is inserted into a nozzle hole formed in communication with the cavity of a resin molding die, and a base part which guides a molten resin injected from a nozzle of an injection molding machine into the nozzle part. In a runnerless injection molding hot nozzle in which at least a portion corresponding to the nozzle portion of the nozzle portion and the base portion is formed of a conductive metal having a predetermined electric resistance, the outlet of the nozzle portion is detachably attached. A hot nozzle for runnerless injection molding, characterized in that it is composed of chips.