Shaping machine and method of operating a shaping machine

Abstract

A shaping machine includes a stationary first mold mounting plate, a second mold mounting plate movable with respect to the first mold mounting plate, a tubular snorkel fixedly secured to the second mold mounting plate, and an injection unit for plasticizing and injecting a molding material. An abutment is designed so that, in the opened condition of the closing unit, the injection unit can be braced against the abutment, and so that, in a closed condition of the closing unit, the injection unit is freed from the abutment by the force action of the snorkel on the injection unit.

Claims

1. A shaping machine comprising: a closing unit which includes a stationary first mold mounting plate, a second mold mounting plate movable with respect to the first mold mounting plate, and at least one tubular snorkel, wherein the at least one snorkel is fixedly secured to the second mold mounting plate; and an injection unit for plasticizing and injecting a molding material, wherein there is provided at least one abutment, the at least one abutment being configured such that in an opened condition of the closing unit the injection unit can be braced against the at least one abutment, and that in a closed condition of the closing unit the injection unit is freed from the at least one abutment by a force action of the at least one snorkel on the injection unit.

2. The shaping machine as set forth in claim 1, further comprising a third mold mounting plate movable with respect to the first mold mounting plate and/or the second mold mounting plate.

3. The shaping machine as set forth in claim 2, wherein the second mold mounting plate is arranged between the first mold mounting plate and the third mold mounting plate.

4. The shaping machine as set forth in claim 1, wherein the injection unit is biased by force actuation by means of at least one spring element.

5. The shaping machine as set forth in claim 4, wherein the at least one spring element is in the form of a mechanical and/or hydraulic spring element.

6. The shaping machine as set forth in claim 1, wherein the at least one abutment is provided at the first mold mounting plate.

7. The shaping machine as set forth in claim 1, wherein the at least one abutment has a bar-shaped configuration at a side of the first mold mounting plate that faces away from the second mold mounting plate.

8. The shaping machine as set forth in claim 1, wherein the at least one abutment has a multi-part configuration, wherein a length of the at least one abutment is variable by a relative movement of the parts of the at least one abutment relative to each other.

9. The shaping machine as set forth in claim 1, wherein the injection unit includes a drive unit configured to move the injection unit relative to the first mold mounting plate.

10. The shaping machine as set forth in claim 4, wherein the at least one spring element can be acted upon with a force by means of a drive unit of the injection unit.

11. The shaping machine as set forth in claim 1, wherein the injection unit is embodied by an axially and rotatably movable plasticizing screw, the plasticizing screw being arranged in a plasticizing cylinder.

12. The shaping machine as set forth in claim 11, wherein in the opened condition of the closing unit the injection unit can be braced directly or indirectly with the plasticizing cylinder against the at least one abutment.

13. The shaping machine as set forth in claim 1, wherein the injection unit has at least one injection nozzle, and wherein the at least one injection nozzle can be braced against the at least one snorkel.

14. The shaping machine as set forth in claim 1, wherein the at least one snorkel projects into an opening in the first mold mounting plate.

15. A method of operating a shaping machine, the shaping machine having a closing unit which includes a stationary first mold mounting plate, a second mold mounting plate movable with respect to the first mold mounting plate, and at least one tubular snorkel fixedly secured to the second mold mounting plate, an injection unit for plasticizing and injecting a molded material, and at least one abutment, the method comprising: bracing the injection unit against the at least one abutment in an opened condition of the closing unit; closing the closing unit by displacement of the second mold mounting plate in a direction of the first mold mounting plate; and upon closure of the closing unit lifting the injection unit off the at least one abutment by a force action of the at least one tubular snorkel on the injection unit.

16. The method as set forth in claim 15, further comprising, upon closure of the closing unit, introducing the at least one tubular snorkel arranged at the second mold mounting plate into an opening in the first mold mounting plate.

17. The method as set forth in claim 15, further comprising, upon opening of the closing unit, moving the second mold mounting plate together with the at least one snorkel in a direction facing away from the first mold mounting plate, whereby the biased injection unit which is lifted off the at least one abutment moves in the direction of the first mold mounting plate until the injection unit contacts the at least one abutment.

18. The method as set forth in claim 15, further comprising, in a shaping cycle of the shaping machine starting from an opened condition of the closing unit, closing the second mold mounting plate in the direction of the first mold mounting plate by means of the closing unit, and with the closing unit closed, feeding molding material by means of the injection unit by way of the at least one snorkel arranged at the second mold mounting plate to a mold tool arranged at the first mold mounting plate and at the second mold mounting plate.

19. The method as set forth in claim 18, further comprising, by means of the closing unit prior to the feeding of plasticized molding material, positioning a mold tool portion arranged at the second mold mounting plate so as to define a stamping gap relative to a mold tool portion arranged at the first mold mounting plate.

20. The method as set forth in claim 19, wherein a width of the stamping gap is selected to be between 1.6 mm and 0.2 mm.

21. The method as set forth in claim 19, further comprising, after the feeding of plasticized molding material, moving the second mold mounting plate in the direction of the first mold mounting plate by the closing unit.

22. The method as set forth in claim 15, further comprising, prior to the bracing of the injection unit against the at least one abutment, setting the at least one abutment arranged at a side of the first mold mounting plate that faces away from the second mold mounting plate, the setting of the at least one abutment comprising: closing the closing unit until a mold tool portion arranged at the second mold mounting plate bears against a mold tool portion arranged at the first mold mounting plate; adjusting a gap dimension between the at least one abutment and the injection unit, with the mold tool portions of the first and second mold mounting plates being in contact with each other, by altering a length of the at least one abutment; and opening the closing unit.

23. The method as set forth in claim 22, wherein the gap dimension is between 0.1 mm and 0.4 mm plus a provided stamping gap.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further details and advantages of the invention are discussed more fully hereinafter by the specific description with reference to the embodiments by way of example illustrated in the Figures, in which:

(2) FIG. 1 shows a first embodiment of a shaping machine according to the invention,

(3) FIGS. 2a-2c show adjustment of an abutment of the FIG. 1 embodiment,

(4) FIGS. 3a-3d show a shaping cycle of the FIG. 1 embodiment

(5) FIG. 4 shows a second embodiment of a shaping machine according to the invention, and

(6) FIGS. 5a-5c show adjustment of an abutment of the FIG. 1 embodiment.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIG. 1 shows a first embodiment of a shaping machine 1 according to the invention. That shaping machine 1 has a closing unit 9 (which can be driven by means of a drive (not shown)) and an injection unit 6. In that arrangement the stationary first mold mounting plate 2 is fixedly connected to the machine frame (also not shown here for the sake of clarity). Secured to the stationary first mold mounting plate 2 is a mold tool portion 15 whose counterpart portion—the mold tool portion 16—is secured to a movable second mold mounting plate 3. A further mold tool portion 19 is further secured to the second mold mounting plate 3, the counterpart portion of the mold tool portion 19—the mold tool portion 20—being secured to a further mold mounting plate 4. Provided at the second mold mounting plate 3 is a snorkel 5 fixedly connected to the second mold mounting plate 3. Subsequently by way of that snorkel 5 a plasticized molding material coming from an injection unit 6 can be fed to the second mold mounting plate 3 which can pass the plasticized molding material 7 to the mold tool portions 16, 19 by way of internal conduits.

(8) The snorkel 5 projects with its free end into an opening 14 in the first mold mounting plate 2. In this embodiment there are two abutments 8 at the side of the first molding mounting plate 2, facing away from the mold tool portion 15.

(9) In this embodiment the injection unit 6 has a drive unit in the form of a spindle drive. That spindle drive is secured to the first mold mounting plate 2 by way of the spring element 10. In addition the injection unit 6 has a plasticizing cylinder 12 which can be brought into communication with the snorkel 5 by means of an injection nozzle 13.

(10) FIGS. 2a through 2c show adjustment of an abutment of the embodiment of FIG. 1. In that case in a first method step (shown in FIG. 2a) the closing unit 9 is closed until a mold tool 16 arranged at the second mold mounting plate 3 bears against a mold tool 15 arranged at the first mold mounting plate 2 and until a mold tool portion 20 arranged at the further mold mounting plate 4 bears against a mold tool portion 19 arranged at the second mold mounting plate 3, as shown in FIG. 2a. In addition a closing force can be built up, as can occur for example at the end of a stamping method. It can be clearly seen by the mold tool portions 20, 19 and the mold tool portions 16, 15 bearing against each other. The injection unit 6 however is always still in a contact-less condition relative to the first mold mounting plate 2, in which case the spring element 10 is released and is without any biasing effect.

(11) In a second method step (see FIG. 2b) the injection unit 6 is now moved by means of its drive unit 11 in the direction of the first mold mounting plate 2 until the injection unit 6 bears with its injection nozzle 13 against the snorkel 5 and the spring element 10 is stressed to a predetermined value. The abutments 8 are then oriented with a gap dimension 18 relative to the injection unit 6. In this respect the abutments 8 in this embodiment are variable in length by being of a two-part configuration. Thus those two-part abutments 8 can be screwed into each other to adjust the length of the abutments 8. The gap dimension 18 in this embodiment is selected at 1 mm, wherein the gap dimension 18 is composed of a safety margin value of 0.2 mm plus an intended stamping gap 17 of 0.8 mm for a later stamping cycle.

(12) In a third method step (see FIG. 2c) the closing unit 9 is opened again, in which case now the injection unit 6 bears against the pre-adjusted abutments 8. As the snorkel 5 was moved away from the injection nozzle 13 by opening of the closing unit 9 the injection unit 6 is thus no longer lifted off the abutments 8 by the snorkel 5. The snorkel 5 is moved away from the injection unit 6 by the opening movement of the closing unit 9 as same is fixedly connected to the second mold mounting plate 3, through the opening 14 in the first mold mounting plate 2. With opening of the closing unit 9 the adjustment method of the first embodiment of a shaping machine 1 according to the invention ends and the shaping cycle of the shaping machine 1 can begin, this being shown by FIGS. 3a through 3d.

(13) In a first step (as shown in FIG. 3a) in that case the closing unit 9 of the shaping machine 1 is closed until the mold tool portions 19, 20 and the mold tool portions 15, 16 are only still spaced relative to each other with a stamping gap 17. In this specific embodiment there is a stamping gap of a size of 0.8 mm. By virtue of closure of the closing unit 9 the snorkel 5 is moved by the second mold mounting plate 3 towards the injection nozzle 13 of the injection unit 6 and the injection unit 6 is freed from the abutments 8 by the force action of the snorkel 5 on the injection nozzle 13.

(14) An impact against the injection nozzle 6 is avoided by virtue of the fact that the abutments 8 position the injection unit 6 in such a way that the injection nozzle 13 and the snorkel 5 meet only when the speed of the second mold mounting plate 3 is already markedly reduced.

(15) In a next step (as shown in FIG. 3b) plasticized molding material 7 is now injected by the injection unit 6, in which case the molding material 7 which is plasticized by the plasticizing cylinder 12 is injected by the injection nozzle 13 into the snorkel 5 which passes the molding material 7 to the second mold mounting plate 3. The arrangement has a hot runner system (not shown) which passes the molding material 7 coming from the snorkel 5 to the mold tool portions 16, 19. The molding material 7 is now passed through the mold tool portions 16, 19 into the cavities provided between the mold tool portions 19, 20 and the mold tool portions 15, 16.

(16) In a next method step of the shaping cycle of the shaping machine 1 (shown in FIG. 3c) the stamping gap 17 between the mold tool portions 19, 20 and the stamping gap 17 between the mold tool portions 15, 16 is now closed by the closing unit 9. That relative movement (closure of the stamping gap 17 between the mold tool portions 15, 16) is compensated by the spring element 10 whereby the injection nozzle 13 still remains pressed against the snorkel 5. The spacing between the abutments 8 and the injection unit 6 however increases from the previously selected safety margin of 0.2 mm (this can be seen in FIGS. 3a and 3b) to a gap of 1 mm which is afforded by closure of the gap 17 of 0.8 mm and the safety margin of 0.2 mm. Upon closure of the stamping gap 17 of the closing unit 9 in that case the volume between the mold tool portions 19, 16 and the injection unit 6 remains unchanged.

(17) In a last step in the shaping cycle the closing unit 9 is now opened again in order to be able to remove the components produced from the mold tools 15, 20. That opened condition of the closing unit 9 is clearly shown in FIG. 3d. The shaping cycle can then begin again from the start (FIG. 3a).

(18) FIG. 4 shows a second embodiment of a shaping machine 1 according to the invention. The structure of the shaping machine 1 is substantially identical to that of the first embodiment shown in FIG. 1, with the exception of the arrangement of the abutments 8. In this embodiment there are no abutments 8 at a side of the first mold mounting plate 2, that is remote from the mold tool 15, but there is an abutment 8 at the spindle of the drive unit 11 of the injection unit 6. Precisely how that abutment can be designed will now be described hereinafter with reference to FIGS. 5a through 5c, wherein FIGS. 5a through 5c show adjustment of the abutment 8 of this embodiment shown in FIG. 4.

(19) For that purpose firstly the closing unit 9 is completely closed until a mold tool portion 16 at the second mold mounting plate 3 bears against a mold tool portion 15 at the first mold mounting plate 2 and a mold tool portion 20 arranged at the further mold mounting plate 4 bears against a mold tool portion 19 disposed at the second mold mounting plate 3, as shown in FIG. 5a.

(20) In a second method step for adjustment of the abutment 8 (shown in FIG. 5b) a gap dimension 18 is now adjusted between the abutment 8 and the injection unit 6 with the mold tool portions 15, 16 bearing against each other, by the length of the at least one abutment 8 being altered. More precisely here a gap dimension 18 of 1.0 mm is set, which is composed of a safety margin spacing of 0.2 mm and a stamping gap 17 of 0.8 mm.

(21) In a last method step (to be seen in FIG. 5c) for adjustment of the abutment 8 of the shaping machine 1 the closing unit 9 is opened again, in which case now the injection unit 8 is biased against the abutment 8 by the spring elements 10.

(22) The actual shaping cycle can be carried out similarly to FIGS. 3a through 3d.

LIST OF REFERENCES

(23) 1 shaping machine 2 first mold mounting plate 3 second mold mounting plate 4 further mold mounting plate 5 snorkel 6 injection unit 7 molding material 8 abutment 9 closing unit 10 spring element 11 drive unit 12 plasticizing cylinder 13 injection nozzle 14 opening 15 mold tool portion 16 mold tool portion 17 stamping gap 18 gap dimension 19 mold tool portion 20 mold tool portion