TIE-BAR-LESS CLAMPING UNIT

Abstract

A tie-bar-less clamping unit for a moulding machine includes a machine frame formed for absorbing clamping forces, and a fixed platen arranged stationary in relation to the machine frame. A movable platen can move relative to the machine frame, and at least one push rod is preferably arranged substantially centrally with respect to the movable platen. At least one pressure pad is arranged between the push rod and the movable platen.

Claims

1. A tie-bar-less clamping unit for a moulding machine, comprising: a machine frame, which is formed for absorbing clamping forces, and a fixed platen arranged stationary in relation to the machine frame, and a movable platen that can move relative to the machine frame, and at least one push rod, preferably arranged substantially centrally with respect to the movable platen, wherein at least one pressure pad is arranged between the push rod and the movable platen.

2. The clamping unit according to claim 1, wherein a movable ejector support plate that can move is arranged between the at least one push rod and the movable platen.

3. The clamping unit according to claim 2, wherein at least one pressure pad is arranged between the at least one push rod and the ejector support plate.

4. The clamping unit according to claim 2, wherein at least one pressure pad is arranged between the ejector support plate and the movable platen.

5. The clamping unit according to claim 1, wherein at least one force transmission unit is arranged between the at least one push rod and the movable platen.

6. The clamping unit according to claim 5, wherein the force transmission unit comprises at least one piston rod and/or one rod and/or one flexure hinge.

7. The clamping unit according to claim 1, wherein at least one mould platen is mounted in a fluid bed within the fixed platen and/or the movable platen.

8. The clamping unit according to claim 7, wherein, if the mould platen is mounted in a fluid bed, the movement of the fixed platen and/or the movable platen and/or the mould platen is guided.

9. The clamping unit according to claim 7, wherein the fluid bed and the fixed platen and/or the movable platen and/or the at least one mould platen are designed, in particular by a protrusion on the mould platen, such that together they have the function of an in particular double-acting hydraulic cylinder.

10. The clamping unit according to claim 1, wherein the clamping unit has at least one, preferably hydraulically and/or electromechanically driven, fast stroke drive mechanism for carrying out a fast stroke movement.

11. The clamping unit according to claim 1, wherein the clamping unit comprises a measuring unit for capturing data, wherein the measuring unit is designed at least to capture data relating to the application of the clamping force and/or the parallelism of the fixed platen and the movable platen.

12. The clamping unit according to claim 1, wherein the clamping unit comprises a control or regulation unit for controlling or regulating the clamping unit, in particular on the basis of data relating to the application of the clamping force and/or the parallelism of the fixed platen and the movable platen.

13. The clamping unit according to claim 12, wherein the at least one pressure pad is a first pressure pad of at least two pressure pads, and the control or regulation unit is formed to control or to regulate the first and a second of the at least two pressure pads depending on each other, and/or preferably also independently of each other.

14. A moulding machine, in particular comprising a substantially C-shaped machine frame, with the clamping unit according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0112] Further advantages and details of the invention are revealed by the figures and the associated description of the figures, in which:

[0113] FIG. 1 shows a first embodiment of a clamping unit according to the invention,

[0114] FIG. 2 shows a second embodiment of a clamping unit according to the invention,

[0115] FIG. 3 shows a third embodiment of a clamping unit according to the invention,

[0116] FIG. 4 shows examples of possible arrangements of pressure pads on a platen,

[0117] FIGS. 5a-b show a fourth embodiment of a clamping unit according to the invention,

[0118] FIG. 6 shows two embodiments of a fluid mounting of a platen,

[0119] FIG. 7 shows a moulding machine with a clamping unit and

[0120] FIG. 8 shows a fifth embodiment of a clamping unit according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0121] FIG. 1 shows a section through a first embodiment of a tie-bar-less clamping unit 1 according to the invention for a moulding machine 16, comprising [0122] a machine frame 2, which is formed for absorbing clamping forces, and [0123] a fixed platen 3 arranged stationary in relation to the machine frame 2, and [0124] a movable platen 4 that can move relative to the machine frame 2, and [0125] at least one push rod 5, preferably arranged substantially centrally with respect to the movable platen 4,
wherein at least one pressure pad 6 is arranged between the push rod 5 and the movable platen 4.

[0126] In this embodiment, the end of the push rod 5 facing the movable platen 4 is arranged adjacent to the piston rod 10 of the at least one pressure pad 6.

[0127] It is preferably to be understood that the left end of the push rod 5 extends further to the left of FIG. 1 (away from the movable platen 4) and that the pressure pad 6, in particular the piston rod 10, is arranged at the right end of the push rod 5 in FIG. 1.

[0128] Preferably, exactly one pressure pad 6 is arranged substantially centrally with respect to the movable platen 4.

[0129] This embodiment has a movable ejector support plate 7 that can move between the at least one push rod 5 and the movable platen 4, wherein at least one pressure pad 6 is arranged between the ejector support plate 7 and the push rod 5.

[0130] As is preferable, FIG. 1 shows at least one force transmission unit 8 arranged between the at least one push rod 5 and the movable platen 4.

[0131] The force transmission unit 8 particularly preferably comprises at least one piston rod 10 and/or one rod and/or one flexure hinge.

[0132] The force transmission unit 8 can generally comprise a combination of a wide variety of force-transmitting elements with a wide variety of arrangements in relation to each other and in relation to other component parts of the clamping unit.

[0133] In the case of this first embodiment the introduction of force is thus effected through the pressure pad 6 directly into the ejector support plate 7, from where it is transferred to the movable platen 4 by means of the force transmission unit 8.

[0134] A locking unit can be located at the end of the push rod 5 opposite the movable platen 4.

[0135] In addition, an ejector device 17, which comprises an ejector bolt 18, ejector plates 19 and ejectors 20 and is used to eject a moulded part, is shown in FIG. 1.

[0136] In this and all following embodiments, the at least one pressure pad 6 is located in the movable part of the clamping unit 1.

[0137] To avoid repetition, it is primarily the differences from the first embodiment that are discussed in the following description of further embodiments. Otherwise, the above description of the first embodiment also holds, where applicable, for the embodiments still to be described below.

[0138] FIG. 2 shows a section through a second embodiment of a clamping unit 1 according to the invention.

[0139] This embodiment has a movable ejector support plate 7 that can move between the at least one push rod 5 and the movable platen 4, wherein at least one pressure pad 6 is arranged between the ejector support plate 7 and the movable platen 4.

[0140] Here, for a preferably symmetrical application of the clamping force, two pressure pads 6 are preferably arranged on the ejector support plate 7, in particular substantially on both sides of the force transmission unit 8.

[0141] However, several pressure pads 6 can also be arranged between the ejector support plate 7 and the movable platen 4, beneficially with at least single symmetry.

[0142] This embodiment also comprises an ejector device 17, wherein the whole ejector bolt 18 is shown in this figure.

[0143] The relatively long at least one piston rod 10 of the at least one pressure pad 6 of this embodiment can be understood to be a subcomponent of the force transmission unit 8.

[0144] A type of force distribution plate is beneficially located at the end of the piston rod 10 facing the movable platen 4 as a further subcomponent of the force transmission unit 8.

[0145] FIG. 3 shows a section through a third embodiment of a clamping unit 1 according to the invention, which is largely the same as the second embodiment of FIG. 2.

[0146] This embodiment differs from the second embodiment in that the piston rod 10 of the at least one pressure pad 6 is designed shorter and a further rod is arranged following the piston rod 10.

[0147] This further rod can be regarded as a subcomponent of the force transmission unit 8.

[0148] With such a combination of piston rod 10 and rod or force transmission element it is possible, for example, to adapt the rigidities and/or the deformation behaviour of the force transmission unit 8 and consequently to exert influence on the tilting behaviour of the movable platen 4.

[0149] FIG. 4 shows six views of examples of possible and preferred arrangements of pressure pads 6 on a fixed platen 3 and/or movable platen 4.

[0150] As can be seen in FIG. 4, it is particularly preferable that the at least one pressure pad 6 is arranged substantially symmetrically, preferably with double symmetry, on the platen, with the result that as symmetrical an application of the clamping force as possible is achieved.

[0151] The at least one pressure pad 6 preferably has a circular or annular shape. However, other shapes, e.g. rectangular shapes, are also possible.

[0152] The first example at the top left in FIG. 4, which has a centrally arranged pressure pad 6, can correspond to the first embodiment, shown in FIG. 1, for example.

[0153] The last example at the bottom right in FIG. 4, which has two symmetrically arranged pressure pads 6, can correspond to the second embodiment, shown in FIG. 2, and/or the third embodiment, shown in FIG. 3.

[0154] Through individual actuation of the pressure pads 6, a different, preferably optimized, introduction of force is possible, whereby the platen parallelism and/or the distribution of the clamping force can be regulated.

[0155] FIG. 5a shows a perspective partial view of a fourth embodiment of a clamping unit 1 according to the invention, which has four pressure pads 6 arranged symmetrically on the movable platen 4.

[0156] FIG. 5b shows a view, associated with this embodiment, of the arrangement of the pressure pads 6 on the movable platen 4. In contrast to all previous embodiments, this embodiment has no ejector support plate 7.

[0157] This embodiment has at least one fast stroke drive mechanism 14 for carrying out a fast stroke movement. The fast stroke drive mechanism 14 is preferably driven hydraulically using a fast stroke cylinder but can also be driven electromechanically by means of a spindle drive mechanism.

[0158] In this embodiment the force transmission unit 8 substantially consists of compression rods. However, other force transmission elements are also conceivable.

[0159] The fast stroke drive mechanisms 14 are beneficially different from the hydraulic cylinders of the pressure pads 6.

[0160] This embodiment has a support plate 15 at least on the drive-side end of the machine frame 2, on which the drive mechanisms, in particular the fast stroke drive mechanisms 14 and/or the pressure pads 6, can be supported.

[0161] The clamping unit 1 particularly preferably has a control or regulation unit for controlling or regulating the clamping unit 1, but this is not represented in the figures.

[0162] If there is more than one pressure pad 6, such as is the case e.g. in the embodiment of FIG. 5, the control or regulation unit is preferably formed to control or to regulate the pressure pads 6 depending on each other, and preferably also independently of each other.

[0163] FIG. 6 shows sections of two embodiments of a fluid mounting of platens or mould platens 13, wherein at least one mould platen 13 is mounted in a fluid bed 9 within the fixed platen 3 and/or the movable platen 4 in each case.

[0164] The fluid bed 9 can be viewed as a replacement for at least one pressure pad 6.

[0165] It may be noted that the mould, not represented, is located on the right-hand side in each case in these sections.

[0166] The movement of the fixed platen 3 and/or the movable platen 4 and/or the mould platen 13, preferably including the mould, is particularly preferably guided, with the result that an involuntary and/or unwanted tilting cannot take place.

[0167] In the right-hand embodiment, the mould platen 13 beneficially has a protrusion 12 along its edge, such that the fixed platen 3 or the movable platen 4 and the mould platen 13 together have the function of an in particular double-acting hydraulic cylinder.

[0168] However, it is also possible that the movement of the fixed platen 3 and/or the movable platen 4 and/or the at least one mould platen 13 is guided in another way, for example by means of at least one guide rod and/or a guide.

[0169] It can also be the case that the movement of the mould itself is guided.

[0170] FIG. 7 shows a moulding machine 16 with the fourth embodiment of a clamping unit 1, already shown in FIG. 5, which has four pressure pads 6 arranged symmetrically on the movable platen 4.

[0171] The fixed platen 3 of the clamping unit 1 is also shown in this figure.

[0172] An injection unit 21 of the moulding machine 16 is also represented.

[0173] The clamping unit 1 and/or moulding machine 16 particularly preferably has at least one measuring unit for capturing data, wherein the measuring unit is not represented in the figures, however.

[0174] The measuring unit is preferably formed at least to capture data relating to the application of the clamping force and/or the parallelism of the fixed platen 3 and the movable platen 4.

[0175] FIG. 8 shows a longitudinal section of a fifth embodiment of a clamping unit 1 according to the invention, wherein the clamping unit 1 does not comprise an ejector support plate 7 and wherein exactly two pressure pads 6 are positioned at and act directly on the movable platen 4.

[0176] The control unit or regulation unit is preferably designed to control or regulate the two pressure pads 6 in dependence of each other, and/or preferably also independently of each other.

[0177] In particular, the upper pressure pad 6, which is positioned further away from the machine frame 2, can be controlled or regulated such that it exerts higher forces on the movable platen 4 compared to the forces exerted by the lower pressure pad 6, which is positioned closer to the machine frame 2.

LIST OF REFERENCE NUMBERS

[0178] 1 clamping unit according to the invention [0179] 2 machine frame [0180] 3 fixed platen [0181] 4 movable platen [0182] 5 push rod [0183] 6 pressure pad [0184] 7 ejector support plate [0185] 8 force transmission unit [0186] 9 fluid bed [0187] 10 piston rod [0188] 11 piston head [0189] 12 protrusion [0190] 13 mould platen [0191] 14 fast stroke drive mechanism [0192] 15 support plate [0193] 16 moulding machine [0194] 17 ejector device [0195] 18 ejector bolt [0196] 19 ejector plates [0197] 20 ejector [0198] 21 injection unit