Injection unit for multi-component injection molding

Abstract

The invention relates to an injection unit for multi-component injection molding with a plastic injection molding machine, comprising two plasticizing units (1, 2), which are arranged on a support (3) overlapping one another and each of which is configured for producing a melt and injecting the melt into a molding tool. In order to achieve a significant simplification when changing the lower plasticizing unit, according to the invention it is proposed that the upper plasticizing unit (2) is pivoted upward about a suitably arranged horizontal axis (9, 12) into a maintenance position relative to the lower plasticizing unit (1) and thereby creates a space for free access to the lower plasticizing unit. By means of suitable support elements (10, 13) the upper plasticizing unit (2) can be held in the maintenance position. The upper plasticizing unit (2) can be pivoted into the maintenance position via a first axis of rotation (9) together with a support frame (8) that supports the upper plasticizing unit or via a second axis of rotation (12) relative to the support frame (8).

Description

Technical Field

[0001] The present invention relates to an injection unit for multi-component injection molding using a plastic injection molding machine, the injection unit comprising two plasticizing units arranged to overlap each other. Background Technology

[0002] It is known from the prior art that, for multi-component injection molding, an injection unit with multiple plasticizing units is provided to prepare the desired melt components and inject the melt into the molding die. Different arrangements of these multiple plasticizing units relative to each other and relative to the molding die are possible (Dr.-Ing. Friedrich Johannaber, Plastic Machine Operator (Kunststoff-Maschinenführer), 4th Edition, 2004, p. 236, Fig. 164). In one of these known arrangements, a first lower plasticizing unit is provided, which is disposed at a central injection point located in the middle of the molding die. A second upper plasticizing unit is disposed obliquely above it, which is disposed at an injection point above the aforementioned central injection point.

[0003] In this type of injection unit, it is known that the upper plasticizing unit (DE4229254A1, DE202010002747U1) is moved relative to the lower plasticizing unit in the longitudinal direction of the machine by a linear drive device.

[0004] Regardless of the aforementioned aspects of the method for moving the upper plasticizing unit relative to the lower plasticizing unit, it may be necessary to replace the plasticizing component of the lower plasticizing unit with another plasticizing component. This may be the case, for example, when the plasticizing component of the lower plasticizing unit suffers a serious defect and must be replaced. Furthermore, if other materials or colors are to be processed, it may be necessary to replace the plasticizing component. High wear may also occur in corrosive materials, leading to failure of the plasticizing component, which similarly necessitates replacement.

[0005] It is known that, for this replacement, almost all connections between the upper and lower plasticizing units must be loosened, and the upper plasticizing unit, as a whole, must be lifted upwards from the lower plasticizing unit using a crane and lowered behind the lower plasticizing unit or to another location on a support. This allows free access to the lower plasticizing unit. After replacing the lower plasticizing unit, the upper plasticizing unit is lifted from the support using a crane, moved onto the lower plasticizing unit, and reconnected to it. The disadvantage of this is the relatively high time consumption associated with it. If only the plasticizing components of the lower plasticizing unit need to be replaced, the above applies in principle. In this case, it is sufficient to simply remove the plasticizing components from the upper plasticizing unit and lower them to another location. Summary of the Invention

[0006] Therefore, the present invention aims to provide an injection unit that can significantly simplify and save time when replacing the plasticizing components of the lower plasticizing unit.

[0007] The core idea is based on the following fundamental concept: the upper plasticizing unit is pivoted about a suitably positioned axis, thereby creating space for free access to the lower plasticizing unit. This free access is particularly possible when the plasticizing components of the upper plasticizing unit are also removed.

[0008] Therefore, according to the present invention, the upper plasticizing unit is pivotable relative to the lower plasticizing unit about a horizontal axis of rotation in at least two positions, namely a first position as an operating position and a second position as a maintenance position. In the operating position, the two plasticizing units are connected to the molding die, and in the maintenance position, the upper plasticizing unit pivots upward from the operating position relative to the operating position. In this document, "operating position" means that the injection unit and thus the two plasticizing units are in a position along the longitudinal axis of the machine, in which the injection unit has a reasonably large distance from the mold platen closest to the injection unit. This distance is sized such that the upper plasticizing unit can pivot freely between the two positions. Furthermore, the distance should be sized such that good access to the lower plasticizing unit is ensured. In this position, the two plasticizing units are connected to the molding die, particularly to the half of the molding die located on the mold platen provided for the injection unit. This mold platen is also called a nozzle plate. Typically, it refers to a stationary mold platen. The connection to the molding die is achieved by moving the two plasticizing units from the operating position toward the molding die and by mating or pressing the nozzles of the two plasticizing units onto the molding die. The maintenance position should be spaced apart from the operating position to ensure good access to the lower plasticizing unit, and in particular good access to the plasticizing components of the lower plasticizing unit.

[0009] It can be specified here that the upper plasticizing unit can pivot out of the operating position at a predetermined pivot angle α relative to the operating position. A predetermined reference point on the longitudinal axis of the upper plasticizing unit can therefore have a predetermined vertical distance from the longitudinal axis of the lower plasticizing unit. In this way, it can be specified how far the maintenance position should be spaced from the operating position.

[0010] According to an advantageous design of the invention, a support frame may be provided, extending at least partially above the lower plasticizing unit. The support frame may be supported by the lower plasticizing unit or detachably connected to it. In the injection unit according to the invention, this support frame facilitates the reception and placement of the upper plasticizing unit. The upper plasticizing unit is preferably detachably fixed to the frame and supported on the support frame.

[0011] According to a first embodiment of the present invention, the support frame can be pivotally connected to the support of the injection unit about a horizontal axis of rotation, the position of which is chosen such that the upper plasticizing unit can pivot together with the support frame between the operating position and the maintenance position.

[0012] According to a second embodiment of the invention, the upper plasticizing unit can be hingedly connected to the support frame such that the connection forms a horizontal axis of rotation, allowing the upper plasticizing unit to pivot relative to the lower plasticizing unit between the operating position and the maintenance position. For this purpose, a front support element and a rear support element are preferably provided on the support frame, with the weight of the upper plasticizing unit supported on the front and rear support elements. The upper plasticizing unit is hingedly connected to the rear support element and detachably fixed to the front support element. In this way, the upper plasticizing unit can pivot from the operating position to the maintenance position in a simple manner and method, without the support frame needing to move with it. It is important to note in this embodiment that the support frame is appropriately designed so that it remains well-accessible to the lower plasticizing unit even in the presence of the support frame, facilitating easy replacement.

[0013] In the injection process according to the invention, a support element should also be provided, by which the upper plasticizing unit can be held in the maintenance position. According to a preferred embodiment, the support element can rotate about the axis of rotation of a horizontal support element and can be positioned in at least two positions: a tilted-in position as a stationary position when the upper plasticizing unit is in the operating position, and a tilted-out position as a support position when the upper plasticizing unit is in the maintenance position. Preferably, the support element can be locked in the tilted-in position and / or in the tilted-out position.

[0014] A support element may be mounted on the support frame, and the support element may rotate relative to the support element about the axis of rotation of the horizontal support element. The position of the axis of the support element on the support frame is related to the structural design of the upper injection unit and, to a lesser extent, to the structural design of the support frame. Only the following is required: the weight of the upper plasticizing unit and the support frame located on the axis of rotation of the support frame away from the conveying side when viewed along the melt conveying direction can be reliably received by the support element and guided into the support.

[0015] Alternatively or additionally, a support element may be mounted on the upper plasticizing unit, and the support element may be rotatable relative to the upper plasticizing unit about a horizontal support axis. The position of the support axis is related to the structural design of the upper injection unit. It is essential that the weight of the upper plasticizing unit, viewed along the melt delivery direction, located on the side furthest from the delivery axis of the upper plasticizing unit's rotation, be reliably received by the support element and guided into a support structure.

[0016] Advantageously, a support element should be provided, which is constructed and arranged such that, in the flipped-out position of the support element, the section of the upper plasticizing unit located in front of the axis of rotation for pivoting the upper plasticizing unit is supported by the support element on the bracket and / or the lower plasticizing unit, and the upper plasticizing unit can be reliably held in the maintenance position. Attached Figure Description

[0017] Subsequently, with reference to the embodiments and references Figures 1 to 4 This invention will be explained in detail.

[0018] Figure 1 An injection unit with an upper plasticizing unit and a lower plasticizing unit in the operating position is shown;

[0019] Figure 2 This illustrates a first embodiment of the invention, wherein the upper plasticizing unit is in a maintenance position;

[0020] Figure 3 This illustrates a second embodiment of the invention, wherein the upper plasticizing unit is in a maintenance position;

[0021] Figure 4 Showing according to Figure 3 In the second embodiment, the plasticizing component is removed. Detailed Implementation

[0022] according to Figure 1 The machine is equipped with a first lower plasticizing unit 1 and a second upper plasticizing unit 2, which are supported together on a bracket 3 and can move forward and backward when viewed in the longitudinal direction of the machine. The lower plasticizing unit 1 can be moved in the longitudinal direction of the machine by means of linear drive devices 26a and 26b (see...). Figure 2 and Figure 3 Here, the upper plasticizing unit 2 can move together with the lower plasticizing unit 1 via a suitable support device or by connection with the lower plasticizing unit 1. Additionally, it can be specified that the upper plasticizing unit 2 can move relative to the lower plasticizing unit along the longitudinal direction of the machine via a suitable linear drive. The two plasticizing units 1 and 2 are arranged overlapping each other such that the longitudinal axes of the two plasticizing units lie in a vertical plane. Each plasticizing unit includes plasticizing components 22a, 23a and drive components 22b, 23b, which are detachably connected to each other at suitable interfaces 24, 25 (see...). Figure 2 and Figure 3 The corresponding drive components 22b and 23b essentially comprise actual drive units 5 and 7, respectively, which have rotational and linear drive mechanisms for manipulating the screw. The lower plasticizing unit 1 has a cylinder (here below the cover 4) in which the screw is rotatably and linearly driven by the first drive unit 5. The screw and cylinder of the lower plasticizing unit 1 constitute the main components of the plasticizing component 22a of the lower plasticizing unit 1. The second upper plasticizing unit 2 also has a cylinder (here below the cover 6), in which a screw and drive unit 7 are rotatably and linearly driven. The screw and cylinder of the upper plasticizing unit 2 constitute the main components of the plasticizing component 23a of the upper plasticizing unit 2. Here, the upper plasticizing unit 2 is supported on the support frame 8 via a front support element 20 and a rear support element 21, such that the upper plasticizing unit is inclined relative to the horizontal plane and thus has an inclined position. The support elements 20 and 21 are connected to the support frame 8 on a linear guide device, allowing them to move along the longitudinal direction of the machine. The support frame 8 is substantially L-shaped in the side view. The upper injection unit 2 is supported and fixed to the horizontal portion 8.1 or L-shaped horizontal leg 8.1 of the support frame 8 by means of support elements 20 and 21. This horizontal portion 8.1 of the support frame 8 is connected to the lower plasticizing unit 1 or bracket 3 in a suitable manner. The vertical portion 8.2 of the support frame 8 or the L-shaped vertical leg 8.2 terminates on the bracket 3 of the lower injection unit 1 and is connected thereto.

[0023] Figure 1 This diagram shows two plasticizing units 1 and 2 in the operating position, with both units potentially connected to the molding die. Depending on the design of the nozzle plate 27, the distance between the injection unit and the nozzle plate 27 can be greater than or must be greater than this corresponding to... Figure 1 As shown in the diagram. The distance is always determined in such a way that the upper plasticizing unit 2 can pivot freely upwards and occupy the space as shown in the diagram. Figure 2 and Figure 3 The position within. According to the invention, the upper plasticizing unit can pivot from the operating position to the position within. Figure 2 and Figure 3 The maintenance location is shown. This should be in... Figure 1 The arrow marked with the reference numeral α indicates this. (For) Figure 2 and Figure 3 References to the maintenance locations are given at the arrows. At interface 24 of the lower plasticizing unit 1, the lower plasticizing component 22a and the lower drive component 22b can be separated and reassembled from each other. At interface 25 of the upper plasticizing unit 2, the upper plasticizing component 23a and the upper drive component 23b can be separated and reassembled from each other. For this purpose, appropriate detachable connections are provided between the corresponding plasticizing components and the corresponding drive components at interfaces 24 and 25. Depending on the work to be performed on the plasticizing unit, both plasticizing components 22a and 23a or only a single plasticizing component 22a, 23a can be removed.

[0024] According to the first variant (see...) Figure 2 The support frame 8, as a whole, and the upper plasticizing unit 2, which is shared with the support frame, are rotatably connected to the bracket 3 about axis 9, so as to move the upper plasticizing unit from the operating position ( Figure 1 Pivot to maintenance position ( Figure 2 In the bracket 3, axis 9 is orthogonal to the machine's longitudinal axis. The horizontal portion 8.1 of the support frame 8 is removably connected to the lower plasticizing unit 1 or the bracket 3 in a suitable manner. Therefore, when the connection of the horizontal portion 8.1 is loosened, the upper plasticizing unit 2 can rotate together with the support frame 8 about axis 9 and be positioned in the... Figure 2 In the maintenance position shown, the first type of support element 10 is rotatably fixed to the support frame 8 about axis 11. The support element 10 can be flipped out from the tilted position (in Figure 2 The horizontal portion 8.1) parallel to the support frame 8 is placed in the flip-out position, where the support element can be locked in a suitable manner with the bracket 3 of the lower plasticizing unit 1. The positions of the rotation axes 11 and 9 on the one hand and the position where the support element 10 is locked with the bracket 3 on the other hand are chosen such that the weight of the upper plasticizing unit 1 and the support frame 8 located to the left of the rotation axis 9 is reliably supported.

[0025] According to the second variant (see Figure 3 Only the upper plasticizing unit 2 pivots from the operating position to the position where Figure 3 The maintenance position is shown in the diagram. Therefore, the support frame 8 can be fixedly or detachably connected to the bracket 3. The axis of rotation for pivoting the upper plasticizing unit 2 is provided in the rear support element 21. The upper plasticizing unit 2 is hingedly connected to the support element 21 there and is therefore also hingedly supported relative to the support frame 8. Therefore, a axis of rotation 12 is provided to move the upper plasticizing unit 2 away from the lower plasticizing unit 1 from the operating position (…). Figure 1 Pivot out and place in Figure 3The maintenance position is shown in the diagram. The second type of support element 13 is rotatably fixed to the upper plasticizing unit 2 about axis 14. The support element 13 can be rotated from the flip-in position (in...) Figure 3 The support element (parallel to the longitudinal axis of the upper plasticizing unit 2) is placed in the flip-out position, in which it can be locked in a suitable manner with the support frame 8 or the bracket 3 of the lower injection unit 1. The positions of the rotation axes 14 and 12, and the position where the support element 13 is locked with the support frame 8 or the bracket 3, are chosen such that the weight 12 of the upper plasticizing unit 2, located to the left of the rotation axis 12, is reliably supported.

[0026] When replacing the lower plasticizing component 22a, the following procedure is recommended. Remove the injection unit as a whole from the mold or nozzle plate 27 until a suitable distance is maintained from the nozzle plate 27. This occupies a position referred to herein as the running position on the machine's longitudinal axis. Now, hold the upper plasticizing component 23a in its position using a suitable holding device, for example, by means of a belt fixed to a crane. In the next step, loosen the connection between the upper plasticizing component 23a and the upper drive component 23b at interface 25. Using the holding device, the upper plasticizing component 23a can be removed from the upper drive component 23b and placed in the parking position. In this way, the space in front of the upper drive component 23b is vacated.

[0027] In the next step, it can be based on Figure 2 and 3 One of the variations involves pivoting the drive component 23b of the upper plasticizing unit 2 upwards and using the support element 10 ( Figure 2 ) or 13 ( Figure 3 Remain in this upward pivoting position. Then, as in Figure 4 China for Figure 3 The variant scheme shown in the text illustrates the situation. For Figure 2 The variant scheme in the middle will produce a similar situation.

[0028] Now, the lower plasticizing component 22a can be removed and taken off from its drive component 22b in a similar manner to the upper plasticizing component 23a. Because the upper drive component 23b (see...) Figure 4 The empty space in front can be achieved without any problems. Now, a new plasticizing component or another plasticizing component can be connected to the drive component 22b of the lower plasticizing unit 1 at interface 24.

[0029] Subsequently, the support element 10 or 13 can be flipped back in, and the drive component 23b of the upper plasticizing unit 2 can be moved back to its starting position. Next, the upper plasticizing component 23a can be connected to the drive component 23b of the upper plasticizing unit 2 at interface 25, so that the upper plasticizing unit 2 can be fully operational again. Finally, the two plasticizing units 1 and 2 can be brought out from their operating positions at a given time and connected to the molding die.

[0030] List of reference numerals

[0031] 1 Lower plasticizing unit

[0032] 2 Upper plasticizing unit

[0033] 3 supports

[0034] 4. Cylinder head of the lower plasticizing unit

[0035] 5 First Drive Unit

[0036] 6. Cylinder head of the upper plasticizing unit

[0037] 7 Second drive unit

[0038] 8 Support Frame

[0039] 8.1 First horizontal leg of support frame 8

[0040] 8.2 The first vertical leg of the support frame 8

[0041] 9. Rotation axis according to the first variant

[0042] 10 Type I support element

[0043] 11. Rotation axis of support element 10

[0044] 12. Rotation axis according to the second variant

[0045] 13 Second type of support element

[0046] 14. Rotation axis of support element 13

[0047] 20 Front support element

[0048] 21 Rear support element

[0049] Plasticizing component of plasticizing unit 1 in 22a

[0050] Drive components of plasticizing unit 1 (22b)

[0051] Plasticizing component of plasticizing unit 2 on 23a

[0052] Drive component of plasticizing unit 2 on 23b

[0053] 24 Interface of lower plasticizing unit 1

[0054] 25 Interface of upper plasticizing unit 2

[0055] 26a First Linear Drive Device

[0056] 26b Second Linear Drive Device

[0057] 27 Nozzle Plate

[0058] α is the pivot angle.

Claims

1. An injection unit for multi-component injection molding using a plastic injection molding machine, the injection unit comprising two plasticizing units disposed on a support (3) with the two plasticizing units overlapping each other, a lower plasticizing unit (1) and an upper plasticizing unit (2) disposed above it, each of the plasticizing units being configured to prepare a melt and inject the melt into the molding die via a nozzle that is joined or pressed onto the molding die by the two plasticizing units. Its features are, The upper plasticizing unit (2) is pivotable relative to the lower plasticizing unit (1) about a horizontal rotation axis (9, 12) in at least two positions, namely a first position as an operating position and a second position as a maintenance position. In the operating position, the lower plasticizing unit (1) and the upper plasticizing unit (2) are connected to the molding die. The connection to the molding die is made by moving the two plasticizing units from the operating position toward the molding die and by mating or pressing the nozzles of the two plasticizing units onto the molding die. In the maintenance position, the upper plasticizing unit (2) A support element (10, 13) is provided to pivot upward from the operating position relative to the operating position. With the support element, the upper plasticizing unit (2) can be held in the maintenance position. The support element (10, 13) can rotate about the rotation axis (11, 14) of the horizontal support element and can be placed in at least two positions, namely, the flip-in position as a stationary position when the upper plasticizing unit (2) is in the operating position and the flip-out position as a support position when the upper plasticizing unit (2) is in the maintenance position. The support element (10, 13) can be locked.

2. The injection unit according to claim 1, Its features are, The upper plasticizing unit (2) is capable of pivoting out of the operating position at a predetermined pivot angle (α) relative to the operating position, and a predetermined reference point on the longitudinal axis of the upper plasticizing unit (2) has a predetermined vertical distance from the longitudinal axis of the lower plasticizing unit (1).

3. The injection unit according to claim 1 or 2, Its features are, A support frame (8) is provided, which extends at least sectionally above the lower plasticizing unit (1), the support frame (8) being carried by or detachably connected to the lower plasticizing unit (1), and the upper plasticizing unit (2) is fixed and supported on the support frame.

4. The injection unit according to claim 3, Its features are, The upper plasticizing unit (2) can be loosely fixed and supported on the support frame (8).

5. The injection unit according to claim 3, Its features are, The support frame (8) is pivotally connected to the bracket (3) about a horizontal rotation axis (9), the position of which is selected such that the upper plasticizing unit (2) can pivot together with the support frame (8) between the operating position and the maintenance position.

6. The injection unit according to claim 3, Its features are, The upper plasticizing unit (2) is hinged to the support frame (8) such that the connection forms a horizontal rotation axis (12), and the upper plasticizing unit (2) can pivot about the horizontal rotation axis (12) relative to the lower plasticizing unit (1) between the operating position and the maintenance position.

7. The injection unit according to claim 6, Its features are, A front support element (20) and a rear support element (21) are provided on the support frame (8). The weight of the upper plasticizing unit (2) is supported on the front support element and the rear support element. The upper plasticizing unit (2) is hinged to the rear support element (21) and detachably fixed to the front support element (20).

8. The injection unit according to claim 1 or 2, Its features are, The support elements (10, 13) can be locked in the in-place position and / or in the out-of-place position.

9. The injection unit according to claim 3, Its features are, A support element (10) is mounted on the support frame (8), and the support element (10) is rotatable relative to the support frame about the horizontal support element rotation axis (11).

10. The injection unit according to claim 1 or 2, Its features are, A support element (13) is mounted on the upper plasticizing unit (2), and the support element (13) is rotatable relative to the upper plasticizing unit about the rotation axis (14) of the horizontal support element.

11. The injection unit according to claim 1 or 2, Its features are, A support element (10, 13) is provided, the support element (10, 13) being constructed and configured such that, in the flipped-out position of the support element (10, 13), the section of the upper plasticizing unit (2) located in front of the rotation axis (9, 12) for pivoting the upper plasticizing unit (2) is supported by the support element (10, 13) on the bracket (3) and / or the lower plasticizing unit (1), and the upper plasticizing unit (2) can be reliably held in the maintenance position.

12. The injection unit according to claim 1 or 2, Its features are, The upper plasticizing unit (2) includes a first plasticizing component (23a) and a first driving component (23b), which are detachably connected to each other at an interface (25).

13. The injection unit according to claim 1 or 2, Its features are, The lower plasticizing unit (1) includes a second plasticizing component (22a) and a second driving component (22b), which are detachably connected to each other at an interface (24).

14. The injection unit according to claim 1 or 2, Its features are, A support element (13) is mounted on the upper plasticizing unit (2), and the support element (13) is rotatable relative to the upper plasticizing unit about the rotation axis (14) of the horizontal support element. The upper plasticizing unit (2) includes a first plasticizing component (23a) and a first driving component (23b). The first plasticizing component and the first driving component are detachably connected to each other at the interface (25), and the rotation axis (14) of the horizontal support element is located at the interface (25), or on the side of the interface (25) where the first driving component (23b) is located, or on the first driving component (23b) itself.

15. The injection unit according to claim 14, Its features are, The rotation axis (14) of the horizontal support element is located on the lower side of the first drive component (23b).

16. The injection unit according to claim 12, Its features are, A support element (10, 13) is provided, which is constructed and configured such that the first drive component (23b) of the upper plasticizing unit (2) is supported and reliably held in the maintenance position when the support element (10, 13) is in the flipped-out position.

17. The injection unit according to claim 16, Its features are, The support elements (10, 13) are constructed and configured such that, in the flipped-out position of the support elements (10, 13), the first drive member (23b) of the upper plasticizing unit (2) is supported and reliably held in the maintenance position when the first plasticizing member (23a) is detached or moved away from the first drive member (23b).

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