JPH074834B2 - Injection nozzle of injection molding machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a nozzle of an injection molding machine, and more particularly to improvement of an injection nozzle of an injection molding machine for injecting a molten material from an injection nozzle to perform molding.

[Conventional technology]

Conventionally, in injection molding in which a molten material such as a resin in a heating cylinder is injected into a mold by bringing the injection nozzle into contact with the mold, the injection nozzle side is easily cooled by the cooling means of the mold,
For the purpose of preventing this, the injection nozzle itself is heated in addition to the heating cylinder.

However, since the tip of the injection nozzle is in contact with the mold set to a temperature much lower than the melting point of the molten material such as resin, it is usually about several tens of degrees lower than the temperature set value of the injection nozzle. Nevertheless, in order to withstand the pressure from the product part of the mold at a temperature of only one system, using a thick nozzle and heater, the tightening plate 101
The maximum outer diameter 103 (see Fig. 10) is increased by thickening and fixing with tightening bolts 102 (see Figs. 9 and 10). Since it is press-fitted, useless resin in that part (generally sprue)
However, there is a problem that the resin cost is wasted and the cost is increased accordingly. Further, there is a problem that when the set temperature is lowered, the resistance of the flow path at the tip of the nozzle increases, and conversely, when the set temperature is raised, burns and resin dripping phenomenon occur.

[Problems to be solved by the invention]

In view of the above-mentioned circumstances, the present invention is capable of individually controlling the temperature of a required portion of an injection nozzle, and by configuring the maximum outer diameter of the injection nozzle so that the maximum outer diameter does not become large, an injection molding machine that eliminates the above-mentioned drawbacks of the conventional technology is provided. It is to provide an injection nozzle.

[Means for solving problems]

In order to solve the above-mentioned problems, the injection nozzle of the injection molding machine of the present invention has a plurality of heating elements and temperature detecting elements that are provided at the required points of the injection nozzle main body that is projectingly provided at the tip of the heating cylinder and is detachable from the heating cylinder. In the injection nozzle of the injection molding machine which is provided with a control mechanism for individually controlling the plurality of heating bodies based on the temperature detection result of the temperature detection body, the outer periphery of the nozzle abdomen is wound and tightened. In addition to providing a mounting plate, a plurality of punch holes, hook-shaped parts or projecting parts are provided on the end edge of the tightening plate, and a tightening wire is attached to the engaging parts to attach the tightening plate. Are configured to be clamped to each other at their edges, and the lead wire of the heating body, the lead wire of the temperature detecting body, and the like are wired through a space formed between the edges of the tightening plate. It is characterized by being configured in.

[Action]

Since the present invention is configured as described above, for example, a coil heater as a heating body provided at the tip of the injection nozzle and a thermocouple for detecting the temperature of the coil heater and a hand heater as a heating body provided at the rear part of the injection nozzle and the same. A thermocouple for temperature detection is provided, the tip of the nozzle close to the mold is set to a high temperature, and the rear part of the nozzle is set to a normal temperature, so that each can be individually controlled, and the inside of the nozzle is wound and tightened. Since the tightening plate is narrowed down using the tightening wire and the wiring of the lead wire is made through the space formed between the edges of the tightening plate, the maximum outer diameter of the heater is not increased.

〔Example〕

An injection nozzle of an injection molding machine according to an embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 to 5, reference numeral 1 denotes a heating cylinder containing a screw, and a nozzle body 3 protruding at the tip thereof. Is detachably connected by screwing means or the like. The nozzle body 3 is provided internally with a flow path 4 and an insertion hole 5 in the axial direction, and a groove 6 is provided in the rear portion 3a of the nozzle body 3 in the axial direction.

A coil heater 7 as a first heating body having a rectangular cross section is wound around the outer peripheral surface of the tip portion 3b of the nozzle body 3, and a lead wire 8 is connected to the rear end.
The coil heater 7 is wound around the tip 3b of the nozzle by about 40 mm.

Further, a temperature detecting thermocouple 9 for the coil heater 7 is provided in the nozzle body 3 and is located in the insertion hole 5,
The tip is buried in the direction of the tip 3b of the nozzle body 3, and the temperature detecting thermocouple 9 is connected to a temperature controller (not shown) via an outlet 13.

On the outer peripheral surface of the middle rear part 3a of the nozzle body 3, a heater 10 for the rear part of the nozzle as a second heating body is wound.
A temperature detecting thermocouple 11 of the heater 10 is located in the groove 6 so as to be sandwiched between the thermocouple and the nozzle body 3.
11 is connected to a temperature controller (not shown) via an outlet 13.

Further, on the outer periphery of the nozzle rear-middle rear heater 10, wire means for the lead wire 8 of the coil heater 7 or the thermocouple lead wire 9a and tightening means for tightening the nozzle middle-rear heater 10 are provided. That is, a fastening plate 14 for fastening the heater 10 is provided on the outer periphery of the rear heater 10 in the nozzle, and the fastening plate 14 is paired with its ends 14a and 14b as locking portions. A plurality of projections (projections) 15 are provided, and a stainless steel wire 16 for tightening is applied to the projections 15, and the tightening plate 14 is narrowed down. The lead wire 8 of the coil heater 7 and the thermocouple lead wire 9a are wired in the space 17 formed by this narrowing.

A heater cover 12 that protects the first and second heating elements wound around the nozzle body 3 is provided so that its tip opening fits with the tip portion 3b of the nozzle body 3.

Needless to say, as the heating means, there are various means such as electromagnetic induction heating other than the general heating means.

FIGS. 6 to 8 show another example of the locking portion. A plurality of punch holes 18 forming a pair are formed in the end portions 14a and 14b of the tightening plate 14, and the punch holes 18 are made of stainless steel for tightening. This shows the tightening plate 14 that has been narrowed down through the wire 16. The lead wire 8 of the coil heater 7 and the lead wire 9a for the thermocouple are wired in the space portion 19 formed by narrowing the wire in the same manner as described above.

Needless to say, the locking portion may be any one other than the above-mentioned two examples, such as a hook-shaped portion, as long as the wire 16 can be wound and tightened.

As described above, the present invention provides the temperature detecting thermocouples at two locations, that is, a portion affected by the mold temperature and a portion particularly related to burning, dripping, etc. Thermocouple 9 connected to the coil heater 7
The thermocouple 11 controls the power supply to the rear heater 10 in the nozzle.
Since the coil heater 7 and the nozzle rear part heater 10 can be individually temperature-controlled because the energization to the nozzle is controlled, the nozzle tip part 3b having the highest resistance and being easily cooled can be heated to a high temperature. And by setting the inner rear portion 3a of the nozzle to a normal temperature, the drop in the nozzle tip temperature can be greatly improved.

Further, the plurality of protrusions 15 or punch holes 18 formed on the tightening plate 14
When the stainless steel wire 16 for tightening is narrowed down to form the space portions 17 and 19, and the lead wire 8 and the thermocouple lead wire 9a can be passed through the space portions 17 and 19, the maximum outer diameter of the heater can be obtained. Does not grow.

〔The invention's effect〕

As described above, the injection nozzle of the injection molding machine of the present invention is capable of individually controlling the temperature of the nozzle tip, the nozzle middle rear part, etc. to the required temperature, and the tightening plate for tightening by winding the inside of the nozzle. The maximum outer diameter of the heater does not increase because the wiring of the lead wire is conducted through the space formed between the edges of the tightening plate.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an injection nozzle of an injection molding machine as an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is a plan view showing the plate, FIG. 4 is a side view thereof, and FIG. 5 is a longitudinal sectional view thereof.
8 shows another modified example, FIG. 6 is a plan view showing a tightening plate for tightening a heater, FIG. 7 is a side view thereof, and FIG.
FIG. 9 is a vertical sectional view thereof, FIGS. 9 and 10 show a conventional example, FIG. 9 is a plan view showing a heater clamping plate, and FIG. 10 is a longitudinal sectional view thereof. 1 ... Heating cylinder, 3 ... Nozzle body, 3a ... Rear part of nozzle, 3b ... Nozzle tip part, 4 ... Flow path, 5 ... Insertion hole, 6 ... Groove, 7 ... As heating element Coil heater, 8
...... Lead wire, 9 ...... Temperature detecting thermocouple, 9a ...... Thermocouple lead wire, 10 ...... Nozzle rear heater, 11 ...... Temperature detecting thermocouple, 12 ...... Heater cover, 13 ...... Outlet, 14 ... Tightening plate, 14a, 14b ... End, 15 ... Protrusion (convex)
Section, 16 …… Stainless steel wire, 17 …… Space section, 18 ……
Punch hole, 19 ... Space section.

Claims (1)

[Claims] 1. A heating cylinder is provided with a plurality of heating elements and a temperature detecting element protruding from the tip of the heating cylinder at a required position of a detachable injection nozzle body, and based on a temperature detection result of the temperature detecting element. In an injection nozzle of an injection molding machine provided with a control mechanism for individually controlling the plurality of heating bodies, a tightening plate for winding and tightening the outer periphery of the nozzle abdomen is provided, and at the edge of the tightening plate. A plurality of locking portions are provided, and a fastening wire is wound around the locking portions so that the edges of the fastening plate are fastened to each other, and formed between the edges of the fastening plate. An injection nozzle of an injection molding machine, characterized in that the lead wire of the heating body, the lead wire of the temperature detecting body, and the like are wired through a space formed therein.