JPS59156725A - Nozzle device of injection molding machine - Google Patents

Abstract

PURPOSE:To prevent the incorrect operation of a poppet and the overflow of molten resin by providing a poppet keeping hole such that said keeping hole has the nozzle hole integrally formed in a nozzle body and a common axis. CONSTITUTION:The poppet 37 having a common axis in a poppet keeping hole 34 is housed so as to be capable of sliding in axial direction. The poppet 37 is composed of the shaft part 37a passing through the poppet keeping hole 34, the head 37b formed on the sheet surface 38 of the tip engagable with and detachable from a nozzle 35, the small size engagable rod 37c passing through the control part of a step 26a and being attachable to a spring retainer 31. The drilling operation of the nozzle 35 and the poppet keeping hole 34 is simultaneously and integrally achieved, when the nozzle body 33 is machined, therefore both holes are drilled with good accuracy of centering. The clearance 12 between the poppet keeping hole 34 and the poppet 35 inserted loosely thereinto is remarkably reduced and both members are sealingly slid. Consequently, the incorrect operation of the poppet due to the accumulation of the resin in the clearance or the overflow of the resin through the clearance is perfectly prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nozzle device for an injection molding machine, and in particular,
The present invention relates to a nozzle device for an injection molding machine that makes it possible to improve the positioning accuracy of a nozzle hole and a poppet for opening and closing the nozzle hole.

In an injection molding machine, the mold is clamped after closing the mold, and during injection,
The molten resin pressurized by a plunger or screw is injected into the mold through the nozzle hole, and when the mold is opened after holding pressure, the nozzle hole is closed to prevent leakage of the molten resin. A nozzle device having the above function is attached to the tip of the heating cylinder.

FIGS. 1 and 2 show the structure of a nozzle device that has been used in such injection molding machines for some time.

In the figure, a plunger 2 is inserted into a heating cylinder 1 so as to be able to move forward and backward, and a nozzle device 3 is installed at the tip of the heating cylinder 1.
is fixed through an upper mold plate (not shown). This nozzle device 3 consists of a nozzle adapter 4 fixed to the tip of the heating cylinder 1, and a nozzle body 5 screwed to the tip of the nozzle adapter 4. The nozzle adapter 4 includes a pair of resin passages 6, A poppet holding hole T and a spring retainer through hole 8 are bored.

The resin passage 6 communicates the plasticizing chamber 9 defined by the heating cylinder 1 and the plunger 2 with the annular space 10 defined by the nozzle adapter 4 and the nozzle body 5, and serves to hold the poppet. The hole 7 is formed along the axis of the nozzle adapter 4, and the poppet 11 is housed therein so as to be freely slidable in the axial direction. This poppet 11 has a poppet holding hole 7
The shaft part 13 has a smaller diameter and forms the required amount of clearance 12 with the nozzle adapter 4, and the shaft part 13 projects into the annular space 10 and has a tip seat surface 14 and a step seat surface 15 (formed therein). It consists of a head part 16 and a stepped seat surface 15.
The gap 12 can be closed by coming into contact with and separating from the tip of the nozzle adapter 4. The spring retainer through hole 8 intersects with the poppet holding hole I and extends in a direction perpendicular to the paper plane in FIG. Since the spring 18 is compressed between the spring retainer 17 and the base of the nozzle adapter 4, the spring retainer 17 is always urged toward the tip of the nozzle adapter 4, and the poppet 11 The rear end of the shaft portion 13 is brought into contact with the rear end of the shaft portion 13 and pressed down.

On the other hand, the nozzle body 5 has a nozzle hole 19 bored on its axis, and the nozzle hole 19 connects the annular space 10 and the resin introduction passage 20 of the upper mold that is fastened to the upper mold plate. communicate,
It is opened and closed by the seat surface 14 at the tip end of the poppet 11. The nozzle body 5 has an annular step 5a that can be engaged with a step 4a formed at the tip of the nozzle adapter 4, and these steps 4a and 5a constitute a spigot mechanism 21 for positioning. are doing.

In the above conventional configuration, the poppet holding hole 7 and the nozzle hole 19 are separately formed in two independent members, that is, the nozzle adapter 4 and the nozzle body 5, and when assembling the poppet holding hole 7 and the nozzle hole 19, After fixing the nozzle adapter 4 to the tip of the heating cylinder 1, the poppet 11 is inserted into the poppet holding hole γ, the poppet 11 is brought into contact with the spring retainer 17, and then, while being positioned by the spigot mechanism 21, the nozzle is inserted. The nozzle body 5 was screwed onto the adapter 4.

In order for the tip sheet surface 14 to reliably close the nozzle hole 19, it is necessary to align the axis of the poppet 11 with the nozzle hole 19.
Therefore, in the conventional nozzle device 3, the nozzle body 5 was positioned and screwed onto the nozzle adapter 4 by the spigot mechanism 21.

However, when positioning using the spigot mechanism 21, it is difficult to accurately align the axis of the poppet 11 with that of the nozzle hole 19! ]L, so even if the poppet 11 is not aligned on the axis of the nozzle hole 19 after assembly, when the poppet 11 is pressed against the nozzle body 5, it can approach the nozzle hole 19 while searching for it. , it was necessary to previously drill the poppet holding hole I to a large diameter to define a large clearance 12 between the poppet 11 and the nozzle adapter 4. By the way, in such a conventional nozzle device 3, the mold During the closing and mold clamping process, the poppet 11 is urged by the elastic force of the spring 18 and comes into contact with the nozzle body 5, closing the isle hole 19, but when the injection process begins, the force is increased as the plunger 2 moves forward. When the pressurized molten resin is press-fitted into the annular space 10 through the resin passage 6, the poppet 11 resists the elastic force of the spring 1, separates from the nozzle body 5, and closes the nozzle hole 1.
Open 9. As a result, the molten resin is transferred to the plunger 2.
The resin flows into the mold engraving space through the resin introduction passage 20 of the mold while being pushed. This ml of molten resin reaches a pressure Sj, but since the step sheet surface 15 closes the clearance 12, the molten resin does not enter into the clearance 12. However, after the pressure holding work PA is completed, plunger 2 retreats and 7
When the pressure of the molten resin in the annular space 10 decreases, the poppet 11 is again urged by the elastic force of the spring 18 and descends to come into contact with the tip of the nozzle adapter 4.

At this time, the large clearance 12 formed based on the above-mentioned necessity communicates with the annular space 10, and the molten resin actively enters into the clearance 12. As a result, the molten resin gradually accumulates in the play gap 12, causing malfunction of the poppet 11.
Furthermore, there is a drawback that molten resin leaks out from the spring retainer through hole 8.

An object of the present invention is to form a poppet holding hole in the nozzle body integrally with the nozzle hole and having a common axis, based on the above-mentioned prior art (in view of problems such as poppet malfunction). This feature allows the poppet to be accurately aligned on the axis of the nozzle hole, thereby reducing play within the poppet holding hole and preventing poppet malfunction and molten resin from spilling out. (It is an object of the present invention to provide a nozzle device for an injection molding machine that has the same structure as above.6) In accordance with the above object, a nozzle body is connected to a nozzle adapter fixed to the tip of a heating cylinder, and the A nozzle hole is formed at the tip of the body, from which the molten phase Ili'? is injected into the mold, and inside the nozzle body extends along the same axis as the nozzle hole. A poppet holding hole is formed integrally with the nozzle hole, and a poppet having a common axis is inserted into the poppet holding hole so as to be slidable in the axial direction while being biased toward the distal end. , poppet 1
The centering accuracy of the holding hole with respect to the nozzle hole, in other words, the centering accuracy of the poppet with respect to the nozzle hole, is maintained at a high level, and the play between the outer periphery of the poppet and the inner periphery of the poppet holding hole is eliminated.
The gist is that the poppet can be tightly inserted into the poppet holding hole.

The structure and C masterpiece of this embodiment of the present invention will be described below with reference to FIGS. 31-6.

Each figure shows a nozzle pike for an injection molding machine according to an embodiment of the present invention. A nozzle adapter 26 is fixed to the tip of a heating cylinder 25, and a heating cylinder is installed inside the nozzle adapter 26. A pair of first resin passages 29 are bored through which the plastic chamber 28 defined by the plasticizing chamber 25 and the plunger 27 is communicated with the tip of the nozzle adapter 26. Furthermore, a storage hole 30 is formed in the center of the nozzle adapter 26 and extends in the axial direction. It intersects with the through hole 32 passing through it. An annular poppet regulating step 26a is bored at the lower end of the through hole 32. A nozzle body 33 is inserted into the storage hole 30, and the nozzle body 33 has a poppet 1 retaining hole 34 extending along its axis, and an opening at the tip aligned with the axis. The nozzle hole 35 and the first resin nozzle path 29 are communicated with the nozzle hole 35 within the tip end of the poppet holding hole 34.
A second resin passage 36 is bored. A poppet 37 having a common axis is housed in the poppet holding hole 34 so as to be slidable in the axial direction. The shaft 3 passing through the poppet maintenance hole 3A, the head 3γb formed on the tip sorting surface 38 that comes into contact with the nozzle hole 35, and the center of the step 26a A shaft portion 37a that extends freely through the splinter retainer 31 and extends from the small-diameter contact rod 3γ that contacts the splinter retainer 31, and from which the contact rod 37C protrudes.
The end face is formed in a direction 39 toward the stepped sheet that engages with the stepped portion 26a. In addition to the processing of the nozzle body 33, the nozzle hole 35 and the poppet [lol, the bud f of the hole 34]
11:J is drilled to a good centering viscosity.

Thus, the poppet holding hole 34 is connected to the shaft portion 37. , 71 yen diameter-C from shaft part 37a to facilitate I0J manual handling
However, the nozzle device 3 equivalent to the one in the conventional nozzle device 3 has not been defeated. If the word "I" is -, +1 in the middle city example, 1st ne, I month j'i 3 pus tract 29
, N, 2Pb passages 36 are a pair of passages 411.
Since there is a growing number C, the 1st and 2nd '91 pilgrimage passages 29.
Relative rotation between the nozzle tab 26 and the nozzle body 33 is prevented by installing locking pins 4o for positioning at positions spaced apart by 90 degrees from the nozzle body 36, respectively.

The nozzle body 331 includes a coupling ring 41 as a coupling means.
A step portion 33a is formed for locking the nozzle adapter 2, and an internal thread 41a screwed onto the coupling ring 41
It can be screwed onto an outer thread 26b screwed onto the tip of the holder 6.

A coil spring 42 is compressed between the splinter retainer 31 and the base end of the nozzle adapter 26, and the splinter 42 constantly urges the spring retainer 31 toward the distal end of the nozzle adapter 26. , the spring retainer 31 is brought into contact with the contact rod 37c. The nozzle device having a sagging structure passes through an upper mold plate (not shown) and an upper mold 44 which is cut in several cases on the lower surface of the upper mold plate.
It is connected to the resin introduction passage 45 of.

In the above configuration, during injection molding work, mold closing,
After mold clamping, when the blanket 27 is moved forward, the plasticizing chamber 28
The pressure of the molten resin in the first and second resin passages 29.3 is increased.
6 Furthermore, since the head 37b of the poppet 3γ is pressed through the tip of the poppet holding hole 34, the poppet 37 resists the biasing force from the spring 42 and moves to the stepped portion, as shown in FIG. The sheet surface 39 slides upward until it comes into contact with the stepped portion 26a, and the nozzle hole 35 is opened. When the plunger 27 continues to move forward after the nozzle hole 35 is opened, the molten resin in the plasticizing chamber 28 flows from the nozzle hole 35 into the resin introduction passage 45 of the upper mold 44 and reaches the mold engraving space. When the pressure of the molten resin is increased, the molten resin tries to flow into the poppet holding hole 34, but since no clearance is defined between the holding hole 34 and the poppet 37, the resin does not flow into the holding hole 34. There isn't.

Even if molten resin gradually enters the poppet holding hole 34 during long-term use, the molten resin will be blocked by the contact between the step sheet surface 39 and the step 26a. Therefore, water does not leak out from the through hole 32.

Subsequently, after the predetermined pressure holding step, when the plunger 27 retreats, the pressure of the molten resin decreases, and as a result, the 31st to
As shown in FIG. 5, the poppet 3γ has a spring 4
2, the tip sheet surface 3B closes the nozzle hole 35, making it possible to open the mold. At this time, since the centering accuracy of the poppet 37 and the nozzle hole 35 is sufficiently ensured, the tip sheet surface 38 does not probe the nozzle hole 35 (goes straight down and closes the nozzle hole 35). to be accomplished.

As described above, according to the present invention, the nozzle hole 35 and the poppet holding hole 34 coaxial therewith are integrally formed in the nozzle body 33, so that the nozzle hole 35 and the poppet holding hole The centering accuracy of 34 °C can be significantly improved, and the poppet 3 that is loosely inserted into the poppet holding hole 34, which was required in the conventional nozzle mechanism, can be improved significantly.
Since the play space 12 between the parts 5 and 5 is significantly reduced and both members are slid in close contact with each other, the poppet may malfunction due to resin accumulation in the play space or 1. This has the excellent effect of completely preventing resin from seeping out through the gaps.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the nozzle structure of the creation molding machine of sub-h11, Fig. 2 is a sectional view taken along arrow A-A in Fig. 1, and Figs.
Fig. 6 shows an embodiment of this invention, Fig. 3 is a sectional view showing the structure of the device, Fig. 4 is a sectional view taken along arrow B-13 in Fig. 3, and Fig. 5 is a sectional view taken along arrow B-13 in Fig. FIG. 6 is a sectional view taken at a different angle from section 90, and FIG. 6 is a sectional view taken at the same position as FIG. 3 during the injection process. 25... Heating cylinder 26... Nozzle adapter 29... First resin passage 30... Storage hole 33... Nozzle body 34...・・・・・・
Poppet 1 retaining hole 35... Nozzle hole 36.
...Second Lap] Grease route 37...Poppet 41...Connection means (connection link) 44...
・Mold (upper mold) 45...Resin introduction passage patented [
Acquaintance Sankyokutate Co., Ltd. (Iku Seisakusho No. 10 7772 Figure 2, Figure 4, Figure 5, 27)

Claims (1)

[Scope of Claims] A nozzle adapter 26 whose base end is fixed to the tip of a heating cylinder 25 and has a first resin passage 29 bored therein through which molten resin from the heating cylinder passes. The nozzle body 33 is connected to the tip of the nozzle adapter and intermittently injects the molten resin from the first resin passage into the resin passage 45 of the mold 44. Nostle hole 3 aligned with resin passage 45 of mold 44
5 is bored, and inside the nozzle body there is a poppet holding hole 34 extending along a common axis with the nozzle hole, and the first resin passage is connected to the poppet holding hole 34 through the tip of the poppet holding hole. A second resin passage 36 communicating with the nozzle hole is bored, and furthermore, a poppet 37 having a common axis with the poppet holding hole is inserted into the poppet holding hole so that its tip abuts and separates from the nozzle hole. 1. A nozzle device for an injection molding machine, wherein the nozzle device is biased toward the distal end and slidably inserted in the axial direction.