CN1139602A

CN1139602A - Hot runner nozzle

Info

Publication number: CN1139602A
Application number: CN 95107858
Authority: CN
Inventors: H·冈特
Original assignee: Dipl-Ing Herbert Guenther GmbH
Current assignee: Dipl-Ing Herbert Guenther GmbH
Priority date: 1995-07-06
Filing date: 1995-07-06
Publication date: 1997-01-08
Also published as: TW289007B

Abstract

A casing of an injection molding machine including at least one hot runner nozzle retains the same by its shaft which extends into a mold insert and which supports at least one nozzle tip that projects over the shaft up to an article to be molded. The nozzle tips are inserted by a two-step movement, VIZ. e.g. in a first direction approximately parallel and then in a transversal direction relative to the axis of a flow tube that is heatable from its outside. The nozzle tips are fixed to a shaft foot portion so as not to contact the casing or a wall of the mold insert. A peripheral step centers the shaft whose high-strength foot portion heat-conductively retains the nozzle tips. A thermally separating sleeve joined to the foot portion is continued to wards the casing by a heat-conducting envelope tube. An inner heat-conductive bush is thermally insulated from the separating sleeve by air gaps and by a supporting ring.

Description

Hot-runner nozzle

The present invention relates to a kind of hot-runner nozzle that is used for injection mo(u)lding machine, this injection mo(u)lding machine has a molding box, a mold cavity plate and a mould shell that has a sidewall, this nozzle comprise a top that has a stream material opening and one by slender axles continuous wide edge body, these slender axles are retained in the molding box, extend in the mold cores and comprise the nozzle head that at least one outwards refers at angle with respect to the axis of a stream pipe, this stream pipe can be from its outside heating, and passing wide edge body and this axle, the wall that the free end of nozzle head passes mold cores non-contiguously reaches to the member for the treatment of die casting.

This nozzle is used for stream of plastic is sent into injection point in the mould from injection mo(u)lding machine.For this reason, must make the thermoplastic materials material in the stream guard system keep flow-like till it cools off in mould.Temperature at each transition point place reduces, and requires that skilled processing method is arranged and reduces so that power attenuation is reduced to.

Known hot-runner nozzle all has nozzle head in its lower end, so that from object of each some spray, perhaps process several objects simultaneously.Traditionally, be with two to four nozzle heads each all parallel with the axis of the stream pipe that passes hot-runner nozzle or be with it in foot that inserts a hot flow path on direction of 45.

Disclosed a kind of design form has been characterised in that a moving element in DE9003574U1, promptly one includes a nozzle body that flows pipe, with one have some radially driven retaining pieces of head, it is used for this device laterally is retained on a position around a narrow czermak space of each injection point maintenance.But, actual experience shows that some melt usually enters between the composition surface and solidifies there.Even consequent not controlled heat insulation radially head is that also can hindering of heat conduction is hot from the transmission of main jet parts to injection point, therefore, the quality of the object of being produced often has very big difference.

Always the objective of the invention is the hot-runner nozzle of prior art is being improved aspect their thermodynamic properties so that overcome above-mentioned defective.

An object of the present invention is to create a kind of simple in structure and firm hot runner nozzle device, it allows the best heat transfer of the injection point of the object for the treatment of die casting.

Another object of the present invention provides a kind of hot-runner nozzle, this nozzle is suitable for making economically, install apace, even using conventional nozzle to be not easy or can not insert fully under the situation of the mould in it and also can produce perfect plastic article in large quantity with cost-effective operation.

For be used for having a molding box, a mold cavity plate and a die casting device with mold cores of a sidewall, a kind of hot-runner nozzle is provided, this nozzle has a top and a wide edge body with a stream material opening, one is retained in the molding box, can and pass the bead body and nozzle head that the axis of the stream pipe of axle outwards refers to an angle so that stretch into slender axles in the mold cores and at least one from outside heating with respect to one, the object of die casting is treated in the wall arrival that the free end of nozzle head passes mold cores non-contiguously.Aspect improvement of the present invention, mold cores separately is made of two halfbodies and nozzle head is retained between them, and the core halfbody is suitable on direction top offset and the closing position in the wedged molding box transverse to this axis.Like this, just can before the assembling two halfbodies removed so that suitably locate nozzle head and fix them on two halfbody closures the time.This device also is specially adapted to the side direction injection, because the reaction force that occurs under injection pressure will only act on the very little terminal area of nozzle head.

For the embodiment of claim 2 seeks independent protection, wherein: mold cores comprises the undercutting that at least one is used to admit nozzle head, and those nozzle heads are installed with the two step motion at an angle direction mutually.In order to enter the rear side of undercutting, between nozzle and mold cores, must carry out a relative motion of bidimensional at least; In fact, this is easy to accomplish.An important advantage is, radially-protruding nozzle head also can make things convenient for and accurately be installed in the opening or vestibule of mold cores.Preferably, these two movement step are orthogonal (claims 3), and wherein first step is the axis that is arranged essentially parallel to the stream pipe, and second step and this axis are at angle, are in horizontal direction (claim 4) basically.

Advantageously, not contact between molding box and nozzle head, nozzle head is embedded into or is wedged in the foot of axle head by mould, the foot of this axle head also separates (claim 5 and 6) with molding box, but with nozzle head fixing and centering (claim 7), especially at step or the shoulder place outside slender axles of contracting again.

According to Claim 8 to 11 described preferred embodiments, this axle comprises a high-intensity foot, and this foot admits nozzle head with heat conduction and ined succession by a hot slider, and this hot slider then is connected on the high-intensity heat conducting element.Like this, axle changes aspect hot gradually; Hot slider, preferably a sleeve that is welded between an envelope tube and this foot is isolated with thermal element and molding box effectively.The heat that is produced is by the special heater that encases the stream pipe tightly, for example a trough of belt heating tube or a variable spiral heating coil, focus on the stream tube end, and the lower end of heater be connected to a mould be embedded into stream tube end and the axle foot on metal lining on (claim 12).

According to claim 13, between the cold joint face of metal lining and distance sleeve, can arrange a heat-resisting or adiabatic ring bearing spare of making by pottery money, titanium, nickel chromium triangle or some other material that hinder the heat transmission, and be advantageously provided conical the air gap at the upper area of metal lining and these elements of distance sleeve.Therefore, Re melt will arrive injection point reliably.In addition, even so fastening design that provides (is substantially equal to 2 to 13tonf/in at high temperature and 300 crust to 2 kilobars ²) also can guarantee economic operation under the actual stress effect of high pressure of scope.

According to claim 14, at least another nozzle head can with respect to stream tubular axis line with the fixed angle between 0 °-90 ° to the foot of axle.So just will promote to realize the cast of many cast gates widely, because nozzle head can very accurately be located, so that treat this object of die casting or the injection point of several objects has maximum heat transmission.

Other features of the present invention, details and advantage can accessory rights require describe and accompanying drawing shown in the following discloses content of preferred embodiment in learn:

Fig. 1 shows a partial sectional view through mounted parts;

Fig. 2 a shows the nozzle mount pad that is similar to Fig. 1;

Fig. 2 b shows the broken section bottom view corresponding to mount pad shown in Fig. 2 a;

Fig. 3 is the longitudinal sectional view of a hot-runner nozzle;

Fig. 4 is the schematic sectional view of another nozzle embodiment.

A hot-runner nozzle that indicates totally by label 10 has been shown among Fig. 1,2a and the 2b has been used in the molding box 12, this molding box 12 has a mold cavity plate 14 and a mold cores 16 in two.This nozzle 10 has a top, this top comprise one by slender axles 20 continuous wide edge body 18.One can be passed wide edge body 18 and axle 20 with one heart from the stream pipe 22 of outside heating.A thin electric insulation layer 24 will flow pipe 22 keeps apart with heater, and this heater can be the heating tube 26 (Fig. 3) of a part fluting.Around or be positioned at the insulating part 27,29 that is used for having other, for example a lining and/or a dish to lateral electrodes binding post 28 arrangement of heater supply capability.

Axle 20 is friendship gradually aspect hot.This axle 20 comprises an outside envelope tube 30, and the top of this pipe includes a flange 32 that meshes with mold cavity plate 14, and this 20 also comprises an inside step or a shoulder 34 that inwardly carries out the transition to slender axles 20 from the outside once more in its underpart.As can be seen from Figure 3, step 34 is rectangular cross sections, and the envelope tube 30 shown in Fig. 1 and 2 a shows the shoulder 34 of an inclination.

Envelope tube 30 is to use high-intensity material, makes as the big tool steel of thermal conductivity.In its bottom, envelope tube 30 is soldered on the distance sleeve 36, these distance sleeve 36 the most handy a kind of heat proof materials, and for example titanium, nickel-chromium steel, pottery etc. are made, and one also is high-termal conductivity, and preferably Huan Xing foot 38 is soldered on the sleeve 36.

A heat conduction lining 40 is inserted in the lower shaft portion 36,38.Its underpart 52 is connected on the lower end of stream pipe 22 and heating tube 26 by a pad 42.An inner conical gap 44 keeps apart this heat conduction lining 40 and the lower area of heating tube 26, has on this zone to be used to increase the line of rabbet joint 66 (Fig. 3) of resistance so that calorie output is focused on the stream tube end.An outer czermak space 54 is kept apart the heat conduction lining 40 and the major part of distance sleeve 36.A support ring 56 that adjoins between the face that is placed in lining 40 and envelope tube 30 provides mechanical stability, but has limited heat transmission there because of its low thermal conductivity.Ring 56 is preferably used a kind of as titanium, nickel-chromium steel, and materials such as pottery are made.

Nozzle head 50,50 ' be attached to thermal conductivity particularly is welded in the best foot 38 of being made by tool steel.Nozzle head 50,50 ' can be with respect to axis A inclination or any angle between outward-dipping 0 ° to 90 °, this depends on the shape of the headstock in the foot 38.Shown in right side among Fig. 1,2a and 2b and Fig. 3,50 an axis A that can be substantially perpendicular to stream pipe 22 extends, and this 22 of stream pipe passes whole hot-runner nozzle 10 and covered by a guard ring 60 at the top.On the contrary, vertical direction is pointed in nozzle head 50 ' (in the left side of Fig. 3), promptly is parallel to the axis A that flows pipe.Fig. 2 a, the 2b illustrated embodiment has only a nozzle head 50, and the axle 20 that has its envelope tube 30 fixed by a frame installed part 62, and frame installed part 62 then is positioned in the mold cavity plate 14 by a wedge shape part 64.

Embodiment illustrated in fig. 4 is same structure basically, and therefore, same element marks with label same among other figure.In addition, lid or guard ring 60 (not shown in Figure 4) also can cover at the top of stream pipe 22, and this stream Guan Zaiqi lower end includes a nozzle head 50 in axis A direction extends into the chamber H of mold cores 16 (also not shown) herein.

Forward on the direction opposite with pad 42, nozzle head 50 comprises the outer expansion section 51 in the lower end of a mould embedding inflow pipe 22.Sealing lip 46 will cover at the body of the nozzle head 50 in fixing zone, top and will flow pipe 22 continuity integrally.But, in its underpart major part, nozzle head 50 does not contact sealing lip 46.On the contrary, sealing lip 46 passes the lower end of heat conduction lining 40 and the foot 38 of axle, and its supporting snap ring 48 that slidably mates.So, when intermeshing element 38,40 (or 42, respectively) and the translation between 46 or translation be the thermal expansion that causes because of thermally equilibrated variation or disturbance or thermal contraction when causing, they will can not arrive obstruction.In operation, melt flows through pipe 22, and for example 1000 clings to (about in other words 6.5tonf/in ²) high pressure force sealing lip 46 to be attached on the snap ring 48, and not repression of swelling and contractile motion in the axial direction.

And between the part of the axle of heat conduction, promptly the distance sleeve 36 between foot 38 and the envelope tube 30 provides the heat insulation to molding box 12 (not being shown among Fig. 4).Because the very simple and economical feature of this kind just can obtain a kind of particularly advantageous energy operation.Opposite with traditional practice, can be to the melt of outflow through the end of arrival axles such as vestibule, passage.

From the example that Fig. 1,2a, 2b install as can be seen, axle 20 and envelope tube 30 are pressed in the mold cavity plate 14 of molding box 12 by embedding.Envelope tube 30 stretches in the mold cores 16 with its whole external diameter, and still, because inside step 34, elongated distance sleeve 36 is free shape in the H of chamber.Thereby the effect of step 34 and/or foot 38 is axle 20 to be felt relieved hot-runner nozzle 10 is felt relieved, and thus, has just guaranteed the accurate shape of the object K that produces.A plurality of nozzle heads 50,50 ' promptly can also can inject simultaneously from object K of each spray for the object of producing a plurality of separation.

Heater can be provided with low-voltage or supply voltage.Under latter instance, reversing the current flows through heater inside, and for low voltage operating, reversing the current then flows directly on the die casting instrument (molding box 12) through stream pipe 22 and wide edge body 18.

Fig. 1,2a, 2b, 3 illustrated embodiments have another heat power advantage.Be heated to operating temperature by flowing pipe 22, the stream pipe can longitudinal dilatation.But, axle 20 together with its

parts

30,36,38 interior, because good heat insulation and only keep quite low temperature levels.Therefore, although the supply of the heat concentrated is arranged, also can prevent widely nozzle head 50,50 ' expansion.This is a particular importance for the less injection point of diameter, because there is no need to revise for the accurate location of each nozzle head the length or the scope of shower nozzle.

Under the situation of an object K of spray who is laterally carrying out through mold wall, also be injected into the situation of product rejection of making in the plastic article K thereby some remaining cooling plastic takes place toward regular meeting.In order to prevent this situation, the present invention is delivered to heat on the surface of the object K that treats mould fully.For this reason, with the

nozzle head

50,50 of hot-runner nozzle 10 ' accurately be adjusted in the mould the tram or height on but any contact do not arranged with it; It is that heat-resisting thermoplastic melt's chamber H just can leak on the wall of mould that heat has only through filling with self.By seal, promptly gap 44 and 54 and support ring 56 and distance sleeve 36 stops along the conductivity of metals of axle 20 envelope tube 30.

The present invention is not limited to described embodiment, but should be understood that, in a preferred embodiment, hot-runner nozzle 10 with a lateral electrode binding post 28 is retained in the molding box 12 of injection mo(u)lding machine and comprises an axle 20 that stretches in the mold cores 16, this axle is supporting at least one nozzle head 50,50 ', this nozzle head stretches out this axle to the object K that treats die casting.Mold cores comprises a undercutting 70, nozzle head 50,50 ', promptly for example be arranged essentially parallel to the first direction S of the axis A of a stream pipe 22 that can heat from its outside by one two step motion, at transverse method Q, insert in this undercutting 70 then with respect to this axis A.Nozzle head 50,50 ' be fixed to is in the axle foot 38 and can not contact with the wall 17 of molding box 12 or mold cores 16.34 pairs of axles 20 of a circumferential step are felt relieved, this foot 38 from intensity can fix with heat

conduction nozzle head

50,50 '.But a hot distance sleeve 36 that joins in the foot 38 is connect to molding box 12 continuously by the envelope tube 30 of a heat conduction.But the neck bush 40 of a heat conduction by the air gap 54,44 and support ring 56 with itself and distance sleeve 36 thermal isolations.

Obviously diagram and description are made in preferred embodiment above, but the viewpoint of adhering to is, changeableization and change are conspicuous under the situation that does not break away from principle of the present invention for the people who is familiar with prior art, and therefore, the present invention should not be regarded as being limited to described special shape.

Claims

1. hot-runner nozzle that is used for injection mo(u)lding machine, this injection mo(u)lding machine has a molding box (12), a mold cavity plate (14) and a mold cores (16) that has a sidewall (17), this nozzle comprise a top (60) that has a stream material opening (19) and one by slender axles (20) continuous wide edge body (18), these slender axles (20) are retained in the molding box (12), extend in the mold cores (16) and comprise that at least one is with respect to the axis (A) of a stream pipe (22) the outside nozzle head (50 of finger at angle, 50 '), this stream pipe (22) can be from its outside heating, and pass wide edge body (18) and the axle (20), nozzle head (50,50 ') the free end wall (17) that passes mold cores (16) non-contiguously reach to the object for the treatment of die casting (K), wherein mold cores (16) separately is made of two halfbodies and with nozzle head (50,50 ') be retained between them, and wherein, the core halfbody be suitable on transverse to the direction of axis (A) displacement and wedged molding box (12) in closing position in.

2. hot-runner nozzle as claimed in claim 1, it is characterized in that: this mold cores (16) comprises that at least one is used to admit nozzle head (50,50 ') undercutting (70), those nozzle heads (50,50 ') be suitable for so that (Q, S) mode of the two step motion on is installed in mutual direction at an angle.

3. hot-runner nozzle as claimed in claim 2 is characterized in that: (Q is orthogonal basically S) to the direction of this two movement step.

4. hot-runner nozzle as claimed in claim 2, it is characterized in that: first movement step is the axis (A) that is arranged essentially parallel to the nozzle (10) of its stream pipe (22), and the direction (S) of second movement step and first movement step acutangulates or right angle and extend substantially transversely to axis (A).

5. hot-runner nozzle as claimed in claim 1 is characterized in that: this nozzle head (50,50 ') mould embedding or the foot (38) that is welded to axle go up and do not contact with mould or molding box (12).

6. hot-runner nozzle as claimed in claim 1 is characterized in that: the foot (38) of axle (20) is radially spaced with molding box (12) at least.

7. hot-runner nozzle as claimed in claim 1 is characterized in that: nozzle head (50,50 ') is by this foot's (38) fixing and centering, and step or shoulder (34) are located especially outside.

8. hot-runner nozzle as claimed in claim 1, it is characterized in that: axle (20) comprises a high-strength foot portion (38), this foot (38) is suitable for heat conduction ground and admits nozzle head (50,50 '), and ined succession by a hot slider (36), this hot slider is connected to again on the big high strength components of thermal conductivity (40).

9. hot-runner nozzle as claimed in claim 1 is characterized in that: axle (20) comprises an envelope tube (30), an annular foot (38) that is welded to distance sleeve (36) on this envelope tube and the nozzle head of ining succession (50,50 ').

10. hot-runner nozzle as claimed in claim 9 is characterized in that: the distance sleeve (36) of axle (20) can dwindle so that form a circumferential step or a shoulder (34) towards the inboard with respect to its envelope tube (30).

11. hot-runner nozzle as claimed in claim 8 is characterized in that: heat conducting element (40) is a metal lining, its underpart (52) be embedded into or be welded to by mould stream pipe (22), heater is (26) with the lower end of foot axle (38) on.

12. hot-runner nozzle as claimed in claim 8, it is characterized in that: between the top of heat conducting element (40) and hot slider (36) and heater (26), be provided with adiabatic apparatus, specifically the air gap (54,44), so that produce the conical gap (54) that at least one is upwards widened by the bottom (52) of heat conducting element (40).

13. hot-runner nozzle as claimed in claim 8 is characterized in that: the seat that adjoins between the face at heat conducting element (40) and hot slider (36) is equipped with at least one heat-resisting support ring (56).

14. hot-runner nozzle as claimed in claim 1 is characterized in that: at least another nozzle head (50 ") be suitable for with respect to the axis (A) of stream pipe (22) with in the foot (38) that is attached to axle between certain angle between 0 ° and 90 °.