INJECTION MOLD FOR TUBULAR PLASTIC PARTS

Abstract

An injection mold (1) for the manufacturing of at least one tubular plastic part comprising a first mold half (2) comprising a first mold plate (3) and a second mold half (4) comprising a second mold plate (5) being arranged displaceable with respect to each other in an axial direction (Z) between an open position and a closed position. The injection mold further comprises at least one core (6) protruding from the first mold plate (3) and the second mold plate (4) comprising at least one cavity (7) suitable to receive the core (6) of the first mold half (2) to form a molding cavity (8) in the closed position of the injection mold (1) for receiving molten plastic material therein to form the tubular plastic part. A bushing (9) is advantageously arranged in the second mold half (4) adjacent to a dorsal end (10) of the cavity (7) at least partially displaceable with respect to the second mold plate (4), said bushing (9) comprising a bore (11) in a closed position of the injection mold (1) suitable to receive a tip (12) of the core (6).

Claims

1. An injection mold for the manufacturing of at least one tubular plastic part, comprising: a. a first mold half comprising a first mold plate and a second mold half comprising a second mold plate arranged displaceable with respect to each other in an axial direction (Z) between an open position and a closed position; and b. at least one core protruding from the first mold plate; and c, the second mold plate comprising at least one cavity suitable to receive the core of the first mold half to form a molding cavity in the closed position of the injection mold for receiving molten plastic material therein to form the tubular plastic part; and d. a bushing arranged in the second mold half adjacent to a dorsal end of the cavity at least partially displaceable with respect to the second mold plate, said bushing comprising a bore in a closed position of the injection mold suitable to receive a tip of the core.

2. The injection mold according to claim 1, wherein the bushing is at least partially arranged in a lateral direction (L) in a floating manner.

3. The injection mold (1) according to claim 1, wherein the bushing is at least partially arranged in the axial direction (Z) in a displaceable manner.

4. The injection mold according to claim 1, wherein the bushing comprises a conical first surface arranged at the outside of the bushing coaxially with respect to the bore interacting in the closed position of the injection mold with a conical second surface arranged at the second mold half such that the tip of the core is centered with respect to the bore.

5. The injection mold according to claim 1, wherein the bushing comprises in a circumferential direction several clamping segments arranged displaceable with respect to each other in a radial direction with respect to the bore such that the tip of the core in the closed position of the injection mold is clamped in the bore.

6. The injection mold according to claim 5, wherein the clamping segments are interconnected to each other by a common base.

7. The injection mold according to claim 1, wherein the bushing is in the closed position of the injection mold at least partially displaceable and/or clampable with respect to the second mold plate by an actuator arranged at least partially displaceable with respect to the second mold plate.

8. The injection mold according to claim 7, wherein the actuator comprises at least one displaceable hydraulic piston and/or a pneumatic piston.

9. The injection mold according to claim 8, wherein the piston is ring shaped.

10. The injection mold according to claim 7, wherein the actuator comprises a spring loaded actuation plate.

11. The injection mold according to claim 10, wherein the actuator comprises a rod-shaped pusher mechanically interconnecting the first mold half and the spring loaded actuation plate in the closed position, such that actuation plate is displaceable with respect to the second mold plate by the rod-shaped pusher.

12. The injection mold according to claim 1, wherein at least one sensor is arranged in or adjacent to the bushing.

13. The injection mold according to claim 1, wherein the bushing is held with respect to the second mold plate or the actuator by a holding means.

14. The injection mold according to claim 1, wherein the bushing comprises at least one cut-out arranged laterally and connecting the bore and the outside of the bushing.

15. The injection mold according to claim 5, wherein the bushing comprises a front segment being arranged during operation between the dorsal end of the cavity and the clamping segments, the front segment comprising an undisrupted inlet opening of the bore for receiving the tip of the core.

16. A method for manufacturing at least one tubular plastic part with an injection mold according to claim 1, said method comprising the following steps: a. closing the injection mold by displacing the mold halves relative to each other from the open position into the closed position, wherein i. the core of the first mold plate is received in the cavity of the second mold plate and the tip of the core projects in the axial direction (Z) from the dorsal end of the cavity, and ii. said tip of the core is received by the bore of the bushing arranged adjacent to the dorsal end of the cavity; b. injecting molten plastic material into the molding cavity to form the tubular plastic part; c. opening the injection mold after the plastic material is sufficiently cured and removing the tubular plastic part.

17. The method according to claim 16 further comprising the following steps: a. clamping in the closed position of the injection mold the tip of the core in the bore of the bushing by displacing the piston in the axial direction (Z) towards the dorsal end the cavity and thereby displacing the clamping segments inwardly in a radial direction (r) via the conical second surface interacting with the conical first surface; and b. releasing in the closed position of the injection mold the tip of the core from the clamping in the bore by displacing the piston in the axial direction (Z) away from the dorsal end the cavity.

Description

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0025] The herein described disclosure will be more fully understood from the detailed description given herein below and the accompanying drawings which should not be considered limiting to the disclosure described in the appended claims. The drawings are showing:

[0026] FIG. 1 shows a sectioned view of a first variation of an injection mold according to the disclosure;

[0027] FIG. 2 shows a detailed view of the first variation shown in FIG. 1 indicated in FIG. 1 with the letter E;

[0028] FIG. 3 shows a sectioned view of a second variation of an injection mold according to the disclosure;

[0029] FIG. 4 shows a detailed view of the second variation shown in FIG. 3 indicated in FIG. 3 with the letter D;

[0030] FIG. 5 shows a perspective view of the bushing of the first variation as shown in FIGS. 1 and 2;

[0031] FIG. 6 shows a perspective view of the bushing of the second variation as shown in FIGS. 3 and 4;

[0032] FIG. 7 shows a perspective view of the bushing of a third variation as shown in FIG. 8;

[0033] FIG. 8 shows a (partial) sectioned view of a third variation of an injection mold according to the disclosure

DETAILED DESCRIPTION OF THE INVENTION

[0034] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

[0035] FIG. 1 shows a sectioned view of a first variation of an injection mold 1 according to the disclosure. FIG. 2 shows a detailed view of the first variation shown in FIG. 1 indicated in FIG. 1 with the letter E. FIG. 3 shows a sectioned view of a second variation of an injection mold 1 according to the disclosure and FIG. 4 shows a detailed view of the second variation shown in FIG. 3 indicated in FIG. 3 with the letter D. In FIG. 5 a perspective view of the bushing 9 of the first variation as shown in FIGS. 1 and 2 is displayed. FIG. 6 shows a perspective view of the bushing 9 of the second variation as shown in FIGS. 3 and 4. FIG. 8 shows a sectioned view of a third variation of an injection mold 1 according to the disclosure and FIG. 7 shows the bushing 9 of the third variation of FIG. 8 in a perspective and exploded view.

[0036] The variations of the injection mold 1 shown in FIGS. 1 and 3 are displayed in a closed position and comprise a first mold half 2 and a second mold half 4. To reach the closed position the two mold halves 2 and 4 are displaced towards each other in an axial direction z from an open position until they are in direct contact. The first mold 2 half comprises a first mold plate 3 and the second mold half 4 comprises a second mold plate 5. The Injection mold 1 further comprises at least one core 6 protruding from the first mold plate 3, in the variations shown several cores 6 protrudes from the first mold half 3. The second mold plate 5 comprises at least one cavity 7 to receive the core 6 of the first mold half 3 to form a molding cavity 8 in the closed position of the injection mold 1, as best visible in FIGS. 2, 4 and 8. A bushing 9 is arranged in the second mold half 4 adjacent to a dorsal end 10 of the cavity 7 at least partially displaceable with respect to the second mold plate 5. The bushing 9 comprises a bore 11 to receive a tip 12 of the core 6 in a closed position of the injection mold 1. As can be seen in FIGS. 2, 4 and 8 the bushing closes in combination with the tip 12 of the core 6 the molding cavity 8 at the dorsal end 10 of the cavity 7 in a molten plastic material tight manner.

[0037] FIGS. 2, 4 and 8 further show that the bushing 9 is arranged in lateral direction L in a floating manner. This is made possible by a holding means 22.

[0038] In order to center the bushing 9 with respect to the cavity 7 the bushing 9 comprises a conical first surface 13 arranged at the outside of the bushing 9 coaxially with respect to the bore 11. The first conical surface 13 interacts in the closed position of the injection mold 1 with a conical second surface 14 arranged at the second mold half 4 such that the tip 12 of the core 6 is centered with respect to the bore 11. In the first variation, visible in FIG. 2, the conical second surface 14 is formed as part of the second mold plate 5 and is arranged in the axial direction z stationary with respect to the cavity 7, between the cavity 7 and the bushing 9.

[0039] In the second variation visible in FIG. 4 the bushing 9 comprises in a circumferential direction several clamping segments 15 arranged displaceable in a radial direction R with respect to the bore 11, such that the tip 12 of the core 6 is in the closed position of the injection mold 1 accommodated and preferably clamped in the bore 11. The clamping segments 15 are mechanically interconnected to the conical first surface 13 on the outside of the bushing 9. This variation of the bushing 9 can best be seen in FIG. 6. In this case the bushing is held essentially stationary in the axial direction z with respect to the cavity 7 by a holding means 22 formed as a circlip 24. The clamping segments 15 are separated by several slits 26 in the bushing 9 extending at least partially in the axial direction z. In the shown variation, the clamping segments 15 are interconnected to each other by a common base 16. In addition, the bushing comprises several cut-outs 23 arranged laterally, each connecting the bore 11 and the outside of the bushing 9 respectively. The cut-outs 23 are each arranged between two clamping segments 15 and the common base 16. Each of the slits 26 discharge in the axial direction in the respective cut-out 23.

[0040] The third variation, as visible in FIG. 8, differs from the second variation, in that the bushing 9 comprises a dedicated front segment 27, here formed as a separate part. In the shown third variation the front segment 27 is formed as a washer-type part, as best visible in FIG. 7. During operation, the front segment 27 is arranged between the dorsal end 10 of the cavity 7 and the several clamping segments 15, extending essentially perpendicular to the axial direction Z. The bore 11 is partially arranged in the front segment 27 comprising an undisrupted inlet opening 28 of the bore 11 for receiving the core 6 in a low-friction manner. As can be seen in FIG. 8, in the closed position, the core 6 is received in the bore 11, the core extending via the inlet opening 28 through the front section 27, such that the tip 12 of the core 6 is in the closed position of the injection mold 1 accommodated and preferably clamped in the bore 11, in particular by the clamping segments 15.

[0041] As best visible in FIGS. 2, 4 and 8 the bushing 9 is in the closed position of the injection mold 1 displaceable and clampable with respect to the second mold plate 5 by an actuator 17 arranged displaceable with respect to the second mold plate 5. The bushing 9 is therefore arranged in the axial direction Z between the dorsal end 10 of the cavity 7 and the actuator 17. The actuator 17 comprises a ring shaped pneumatic piston 18, which is displaceable in the axial direction z to induce a relative force between the conical first surface 13 and the conical second surface 14. In the first variation, shown in FIG. 2, this leads an alignment between the bushing 9 and the cavity 7, and therefore an alignment between the core 6 and the cavity 7, as the core 6 with its tip 12 in the bore 11 of the bushing 9 is guided into this alignment by the bushing 9. In the second and third variation, as shown in FIGS. 4 and 8, the actuator comprises a pusher insert 25 and an alignment is achieved an analogous way. Here, the conical second surface 14 is formed as part of the actuator 17, in particular as part of the pusher insert 25 and is in the axial direction z displaceable with respect to the cavity 7. The actuator 17 further comprises a spring loaded actuation plate 19, which is configured to exert a restoring force in the axial direction z. The actuation plate 19 is in the shown variation ring shaped similar to shape of the piston 18 and further comprises through bores to partially accommodate the pusher inserts 25.

[0042] To monitor the manufacturing of the tubular plastic parts at least one sensor 21 is arranged in or adjacent to the bushing 9.

[0043] Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the scope of the disclosure.