WO2008004968A1

WO2008004968A1 - Device at lateral heated ingot mould including adjustable radial torpedo points

Info

Publication number: WO2008004968A1
Application number: PCT/SE2007/050488
Authority: WO
Inventors: Hans Müller
Original assignee: Mueller Hans
Priority date: 2006-07-06
Filing date: 2007-07-03
Publication date: 2008-01-10
Also published as: SE0601497L; SE529794C2

Abstract

The claimed invention concerns a device (1) at a lateral heated ingot mould (2) having a number of lateral outlets from channels intended for throughput of molten plastic material. Said outlets are equipped with movably adjustable torpedoes (6) that can be displaced axially (8) in displacement channels (16) extending substantially radially in the ingot mould. A turnable mot ion- transfer shaft (9) extends transverse to the displacement path of the torpedo, said shaft is co-operable with the torpedo regarding the transfer of said turning motion (10) by gripping members (12), said shaft and torpedo thus being in turning co-operation with each other, at least during the time of displacement. The adjustable shaft (9) is provided with indication means arranged to indicate the axial position of the torpedo (9).

Description

Device at lateral heated ingot mould including adjustable radial torpedo points

The present invention relates to a device at a lateral heated ingot mould having a number of feeding-out openings going laterally from a channel intended for the throughput of plasticizable plastic material, which openings are provided with movably actuatable torpedo points, which, by means of means regulating from the outside of said ingot mould, are actuatable to be displaced axially between a retracted position and a projected position in displacement channels extending substantially radially in the ingot mould, a turnable motion- transfer shaft extending transverse to the displacement path of the torpedo point, which shaft, on one hand, is actuatable to be turned, and on the other hand is co-operable with the torpedo point in question for the transfer of said turning motion into displacement motion of the torpedo point by means of gripping members in the form of grooves arranged between said motion-transfer shaft and a torpedo point and being in turning co-operation with each other, at least during the time of displacement .

It is previously known to actuate radially movable torpedo points in a heated ingot mould from the outside of the heated ingot mould. See for instance EP 0200048 A2 and

GB 2085350 A, respectively, by which it is previously known to arrange axially movable torpedo points at an ingot mould, remote controllable, however movable only in the axial direction common with the injection direction of the plastic mate- rial, i.e., that said known ingot mould is not a lateral heated ingot mould.

By US 3912133 A, a nozzle is shown having a likewise axially movable point actuatable by a turnable rod. There are lateral heated ingot moulds for plastic materials and that work with so-called slug systems, which via fixed outlets push a plastic cold slug into a laterally- displaced cavity in question before the filling therein can take place. This entails that the remaining steel of the tool between a gating system and an accomplished plastic detail in question in prior art is not so large.

Furthermore, there is lateral heated ingot mould that has a few, one or two fixed torpedo plastic injec- tion points. Thereby, said remaining steel surface of the tools is increased, but on the other hand, it has the disadvantage that the gating system cannot be built in, in case tool plates are not divided along the centre line. In that connection, the number of outlets is also limited to at most two. In order to try to solve the above said assembling problem, tool plates have also been formed that are partable along the longitudinal direction of the tool, for instance that loose insertion pieces of tool plates enable the assembling of the tool into the complete state, but this has turned out to be cumbersome, expen- sive and has not been so reliable.

By the Swedish patent application No. 9203783- 7, settable lateral heated ingot moulds are previously known and that are constructed in such a way that the torpedo points can be returned in such a way that the gating system can be installed and dismounted in unparted tool plates. The remaining steel between the gating system and plastic the detail is substantially greater than in gating systems with "cold slug".

Such a gating system has also the advantage that a plurality of outlets can be placed along the circumfer- ence. The torpedo points can, by virtue of the setability, exactly be adapted to the plunge depths in question. The gating system can be built with centrally controlled mobility of the torpedo or with separate movable torpedo points. However, it has turned out that the adjustability has not been so easy to bring about due to the lack of markings. Furthermore, set values could have been affected during operation as well as that the existing seal has not effi- 5 ciently prevented the penetration of plastic material into undesired spaces in the heated ingot mould, as well as that the action on the seal has a detrimental effect.

It is also known with adjustable radial points, but each time, the ingot mould first has to be dismounted from

LO the bottom thereof and in that connection clear away all remaining plastic before the points can be detached and then also be adjusted axially in the radial direction of the ingot mould.

A lateral heated ingot mould, also previously

L5 known by SE 505 685 C2 , is known to be remote controlled axially or by oblique points. There are problems in all previously known solutions. On one hand, plastic extruded into spaces between movable parts penetrates and clogs the spaces therein in such a way that the mobility decreases, and on the other

20 hand, it is hard to exactly know the position of the pro- jectable gating points when the gating system is installed and in use. For instance, position marking is lacking for the installed gating point, which also makes it hard to exactly know the position thereof.

15 Thus, there are, among others, the following problems in known solutions:

^■ Adjustment of the gating point unmanageable after the installation of the gating body.

^■ The leakage of the gear wheel fixture of the older applica- }0 tion.

^■ The difficult dismounting of the gating body after some time of use (the points cannot be retracted) . Therefore, the main object of the present invention is primarily to solve the above first-mentioned problem and then also the additional ones.

Said object is attained by means of a device according to the present invention, which essentially is characterized in that the respective sealed actuatable motion- transfer shaft is provided with an indication means arranged to indicate the axial position of the torpedo point in question in the appurtenant radially extending displacement channel. The advantages that the invention, among other things, entails are the following:

^■ One does not have to use a washer as in earlier solutions.

^■ One can easily preset a determined measure of the torpedo points . ■ One can now clearly see the position, i.e., retracted or extended position, of the point from the topside of the ingot mould.

^■ One does not need to mess about with plastic for the dismounting and adjustment of the points. ■ One can easily install and dismount, respectively, the points and the appurtenant parts in the ingot mould.

^■ Replacement of the heating coil is now possible, also when the tool is in the heated state.

The invention is described below in the form of a number of preferred embodiment examples, reference being made to the accompanying drawings, in which,

Fig. 1 shows a heated ingot mould in the dismounted state outside a machine and having radial torpedo points shown in the projected position, Fig. 2 shows a longitudinal section of said heated ingot mould and in partly shown built-in position in the machine, Fig. 3 shows a cross-section view of the lower portion of the ingot mould and with motion action of the shown torpedo points,

Fig. 4 shows a section view along the line A-A 5 in Fig. 2,

Fig. 5 shows the heated ingot mould as seen in the direction of the arrow B but without cap,

Figs. 6-8 show variants of indication, clamping and sealing at a said lateral heated ingot mould,

-0 Figs. 9-11 show an additional embodiment example of the invention where,

Fig. 9 shows a longitudinal section view of a heated ingot mould having a lower loosenable plate,

Fig. 10 shows a cross-section view of said L5 heated ingot mould along the line X-X, and

Fig. 11 shows a side view of the lower portion of said heated ingot mould.

A device 1 at a lateral heated ingot mould 2 for plastic and having a number of feeding-out openings 5 going 10 laterally 3 from a channel 4 intended for the throughput of plasticizable plastic material, which openings are provided with movably actuatable torpedo points 6, which, by means of means regulating from the outside 7 of said ingot mould, are actuatable to be displaced axially 8 between a retracted posi- _5 tion I and a projected position II in channels 16 extending substantially radially in the ingot mould, is shown in the drawings .

Transverse to the displacement path of the torpedo point, a turnable sealed motion-transfer shaft 9 extends, 10 which, on one hand, is actuatable to be turned, and on the other hand is co-operable with the torpedo point in question for the transfer of said turning motion 10 into displacement motion 11 of the torpedo point 6 by means of gripping members 12 in the form of grooves 13, 14, i.e., teeth arranged between said motion-transfer shaft 9 and a torpedo point 6 and being in turning co-operation with each other, at least during the time of displacement. According to the invention, the respective actuatable sealed motion-transfer shaft 9 is provided with an indication means 15 arranged to indicate the axial position of the torpedo point 6 in question in the appurtenant radially extending displacement channel 19. In that connection, the indication means consists of a marking 15 movable in relation to the lateral heated ingot mould 2 and the motion-transfer shaft 9 and being in the form of one or more marking lines and suitably then also a fixed zero point 17 or a marking scale, etc., in such a way that a certain position on the marking 15 along said zero point or marking scale indicates in which radially displaced position the appurtenant point 6 is set after turning actuation of the appurtenant motion-transfer shaft 9. In that connection, a marking 15 is arranged on the turnable head 18 of the motion- transfer shaft 9 arranged to be turned a determined part of a revolution when an appurtenant torpedo point 6 is actuated to be displaced radially in the appurtenant axial channel 16.

In that connection, there is a locking means 20 to allow locking of the set motion-transfer shaft 9 in the desired set turned position and this is preferably formed of a radial locking screw 20. Said locking screw 20 is arranged actuatably received in an appurtenant radially threaded hole 21 in a covering cap 22. The locking screw 20 locks the continued turning motion of the motion-transfer shaft, with the point 23 on the locking screw 20.

Said point 23 or a spherical washer is preferably arranged to abut and be pressed against the circumference 24A of a hood 24 threadable over the actuatable head 18 of the motion-transfer shaft, which hood internally 24B is shape- adapted to said head 18, the same being locked effectively by means of a said locking screw 20.

A common cap 22 is arranged to cover all heads 18 and hoods 24. Said cap 22 is arranged to be detachably fastened to the rear body 25 of said lateral heated ingot mould 2, by means of bolts 31.

The hoods 24 are shape-adapted externally 24A to the internal space 22 A of the cap and are preferably round while the heads of the respective locking screw 20 are formed of Allen-key openings 310 and that the head of the respective motion-transfer shaft 9 preferably is formed of square or hexagonal screw heads .

A sealing bushing 150, clearly shown in Fig. 8 and formed of two ring-shaped cylindrical parts 151, 152, surrounds said motion-transfer shaft 9 at the lower end thereof and is, by one of the parts 152, partly threaded on the other part 151. This bushing 150 is arranged to, at increasing injection pressure from the plastic injection material in question, be pressed inward toward a surrounded motion-transfer shaft 9 received internally in the same. Suitably, said bushing 150 is situated straight above and at the area of a cogwheel 60. Furthermore, a support ring 250 is arranged to carry axial action from the connecting motion-transfer shaft 9 and thereby said seal bushing 150 is protected from being damaged by excessive axial force action. Furthermore, the hoods 124 may be provided with resilient gripping members 155 that engage mating recesses 156 of the appurtenant head 118 of the shaft 9.

The nature and function of said invention should have been clear from what has been described and shown.

The advantages of the invention are now, among other things, that differently sized torpedo points need not be marketed. Thus, it is enough with one and the same size of the torpedo points that simply can be adjusted to accommodate different conditions, and that are easy to install, and that can be preadjusted according to the particular measure of the customer's gating system in question. It is namely important that the point 6 with the conical outer portion 6A thereof does not reach too far out. Then, a scratch on the formed part of plastic may be formed.

In order for the expansion of the points 6 to be limited, the same may be selected from a suitable metal, e.g., copper or steel, and in order to prevent the plastic from sticking and in order to provide a hard surface on the point to prevent oxidation thereon, the points may be covered by a suitable means, e.g., tin nickel or Balanite™. Furthermore, the function of the invention is that when the cap 22 is opened, it possible to see in which position the respective point is, thanks to the measuring lines, etc. , 15.

Turning of the motion-transfer shaft 9 in either direction 200 and 300, respectively, making the motion to be transferred via the cogwheels 60 and the teeth 13 thereof to the teeth 14 of the points 6. That is, the turning motion 10 is transferred into linear motion 11. Then, retraction of the points 6, 6A in the ingot mould 2 from the appurtenant recep- tion space 600 thereof and the openings 5 in the tool plate 100 is made possible.

Thus, extrusion of plastic can be effected under exact conditions as regards the width of the extrusion opening 75, thanks to the regulation of the points under clear conditions.

The new is also that a sealing bushing 150, at increasing injection pressure, is pressed against the movable shaft 9 for absolute tightness. The support ring 250 prevents the bushing 150 from being damaged by axial action. The sealing principle also allows small axial motions caused by different thermal expansions, since part 2 can be made of copper and part 9 is made of steel. The nozzle jacket consists of part 700 and 800.

Part 700 has to be dismounted when the heating coil 1000 is replaced. Easy access to the element 1000 is required, since the points cannot be moved in a cold nozzle.

New is also a preadjustment principle for the point 6. The final position of the point 6 can now be pread- justed before the nozzle is installed. The point 6 is turned accurately into the desired position by means of an altimeter. Next, the hood 24 is installed, which has an interior hexagon or profile on the shaft 9. Then, the cap 22 is installed. The fixation of this preadjusted position is effected by means of screw 31. A washer 23 including the sphere thereof contributes to a reliable locking of the hood 24. Next, the cap 22 is dismounted in such a way that the point 6 can be retracted, and now the nozzle 2 can be installed in the tool . After that, the locking of the hood 24 must not be loosened so that the correct position of the point 6 cannot be found again when the nozzle is installed.

According to an alternative embodiment of the invention and as is seen in Figs. 9-11, the problem of removing clogged plastic in the bottom 200 of the gating system 202 is solvable. For certain plastics, under long term and unfavourable heating conditions, the plastic may harden, "coke".

It is important to be able to remove this if it occurs, so that the tool is not clogged and becomes unusable. Upon dismounting and removal, the bottom plate remains in the machine .

The torpedo points 206, in the present embodiment described below, are installed in bores 201 positioned in the solid intermediate part 203 of the gating system 202. When extruding a plastic material susceptible to coke and harden, a solution has to be at hand allowing the nozzle to be dismounted after a longer time of use. A proposal to solve this is that a thin bottom plate 204 is screwed onto the underside of the nozzle using long screws 205, and where the bores 201 for the torpedo points 206 are situated one half in the bottom plate 204 and the other half in the body 203 of the nozzle.

If it turns out, in this alternative embodi- ment, that the points 206 cannot be returned by means of the cogwheels, the fittings 205 of the bottom plate 204 are easily loosened and the bottom plate 204 and the intermediate part 203 of the gating system are lifted apart from each other. Then, the bottom plate 204 as well as the torpedo points 206 remain in the tool plate 207 when the gating system 202 is lifted out.

Adjustment of the depth of the points 206 in the vertical direction may be made using similar means as in the embodiment examples described above, i.e., by means of an elongate axially situated motion-transfer shaft 209 for each point 206 inside the gating system 202. Also this shaft 209 has a seal 275 according to the embodiment described above and shown in the drawings, and having a function similar to the same .

A seal for each point 206 may also be arranged to prevent plastic from penetrating into the appurtenant bore 201 thereof or recesses formed in another way. Pressures up to approx. 2000 bar are common. Suitably, said additional seals 210 are arranged at the front motion space of the points in the bores 201. Said additional seals 210 may be of a type similar to the seals 275, or of another suitable efficient type. Also, locking hoods 224, which are internally shape-adapted to the upper, wrench-opening shaped head 218 of the transfer shaft 209, are arranged to lock the transfer shafts 209 in the adjusted position by means of externally actuatable locking screws 220.

Said locking screws 205 for the clamping of the bottom plate 204 may be formed of long screws that have a thread 230 at the outer end 205A and that are received in a threaded hole 231 in the bottom plate 204. Access to said screws 205 is not provided until a cap 222 and a jacket part 270 have been removed from the ingot mould. Alternatively, reception holes 232 for said locking screws 205 may extend all the way up to the upper portion 222A of the cap 222, shown line-mounted in Fig. 9.

Also here, transfer of motion from rotary motion from the shaft 209 into radial motion of the points 206 may be effected by means of cogwheels 260 and a rack 214. Internally in the ingot mould 202, inlet channels 233, 234 extend for the supply of heat-hold plastic/metal to the points 206 of the nozzles that regulate the discharge of the compound by axial displacement of the points 206.

Adjustment after the installation of the parts may be effected as follows:

^■ Careful adjustment of the gating point before the installation of the gating body upon use of measuring means.

^■ Putting the hood 24 on the (hexagon) heads 18 of the shaft 9. ■ Putting the cap 22 on the hoods 24.

^■ Locking the stop screw 20. Thereby, the hoods 24 in the cap become fixed.

^■ Taking off the cap and turning back the gating point into the gating body. ■ Coarse adjustment of the gating system by the use of a pointer 15.

^■ Fine adjustment by putting on the cap 20 by the use of the hoods 24. Here is considered the particular fact that the hoods 24 primarily have the function of safeguarding the correct angular position of the shaft 9, i.e., in the first stage the hoods adapt to the position of the shaft. After the fixa- tion thereof in the cap, they now serve as a gauge for the correct position of the shaft. In addition, the hoods 24 and/or the heads 18 show adjustment diagonals that provide for the levelling of the small erroneous angular positions of the shaft 9 upon the putting on of the cap, i.e., that a quasi-automatic position adjustment takes place, which is fixed in the extended state.

The number of points may be varied according to the need and space, e.g., two, three, four, six and eight, etc.

Axial projection of the points is described and shown, but the points may also be arranged to be displaced at another angle than right from the centre axis 251 of the gating system, i.e., oblique. The transfer shafts 209 may, in that connection, also be obliquely arranged in relation to said centre axis 251. Naturally, the invention is not limited to the embodiments described above and shown in the accompanying drawings. Modifications are feasible, particularly as for the nature of the different parts, or by using an equivalent technique, without departing from the protection area of the inven- tion, such as it is defined in the claims.

Claims

5 1. Device (1) at a lateral heated ingot mould (2) having a number of feeding-out openings (5) going laterally (3) from a channel (4) intended for the throughput of plasticizable plastic material, which openings are provided with movably actuatable torpedo points (6) , which, by means of means regu-

LO lating from the outside (7) of said ingot mould, are actuatable to be displaced axially (8) between a retracted position (I) and a projected position (II) in displacement channels (16) extending substantially radially in the ingot mould, a turnable motion-transfer shaft (9) extending transverse to the displace-

L5 ment path of the torpedo point, which shaft, on one hand, is actuatable to be turned, and on the other hand is co-operable with the torpedo point (6) in question for the transfer of said turning motion (10) into displacement motion (11) of the torpedo point (6) by means of gripping members (12) in the form of

20 grooves (13, 14) arranged between said motion-transfer shaft (9) and a torpedo point (6) and being in turning co-operation with each other, at least during the time of displacement, characterized in that a means is arranged to provide a predetermined adjustment of the turning position of the shaft (9)

25 after the installation of the gating body (2) in the tool plate (100) in question.

2. Device according to claim 1, characterized in that the respective sealed actuatable motion-transfer shaft (9) 30 is provided with an indication means (15) , which consists of a marking (15) movable in relation to the lateral heated ingot mould (2) and the motion-transfer shaft (9) , and which is arranged to indicate the axial position of the torpedo point (6) in question in the appurtenant radially extending displacement channel (16) , the marking (15) on the turnable head (18) of the motion-transfer shaft (9) being arranged to be turned a determined part of a revolution when the appurtenant torpedo point (6) is displaced radially in the appurtenant axial channel (16) .

3. Device according to any one of the preceding claims, characterized in that there is a locking means (20) to lock the set motion-transfer shaft (9) in the desired set position.

4. Device according to claim 3, characterized in that a radial locking screw (20) is arranged to lock the con- tinued turning motion of the motion-transfer shaft (9) .

5. Device according to claim 4, characterized in that an internally (24B) shape-adapted hood (24) over the actuatable head (18) of the motion-transfer shaft is arranged to be locked by means of a said locking screw (20) .

6. Device according to claim 5, characterized in that a common cap (22), which is arranged to cover all heads (18) and hoods (24) , is arranged to be detachably fastened to the rear body (25) of said lateral heated ingot mould.

7. Device according to claim 6, characterized in that the hoods (24) are shape-adapted externally (24A) to the internal space of the cap.

8. Device according to claim 7, characterized in that the hoods (24) are round while the heads (18) of the respective motion-transfer shaft (9) are formed of Allen-screw heads .

9. Device according to claim 7, characterized in that the heads of the respective motion-transfer shaft are formed of square or hexagonal screw heads (18) .

10. Device according to any one of the preceding claims, characterized in that a sealing bushing (150) surrounds the motion-transfer shaft (9) and is, at increasing injection pressure, arranged to be pressed inward toward said surrounded motion-transfer shaft (9) received internally in the same.

11. Device according to claim 10, characterized in that a support ring (250) is arranged to carry axial action from the surrounding motion-transfer shaft (9) , thereby the seal bushing (150) being protected from being damaged by axial action.

12. Device according to any one of the preceding claims, characterized in that seal (210) is present at the points (206) in order to prevent, or at least make more difficult, penetration of flowing compound into the drive mechanism (260, 214) of the points.

13. Device according to any one of the preceding claims, characterized in that a bottom plate (204) is fas- tenable by screws on the underside of the nozzle.

14. Device according to claim 13, characterized in that the bottom plate (204) is tightened by long screws (205) that are actuatable from the topside of the nozzle.

15. Device according to any one of claims 13-14, characterized in that bores (201) for the torpedo points (206) are situated in the bottom plate (204) and in the body (203) of the nozzle.