Locking device, closing unit and forming machine

Abstract

Locking device for locking a mold mounting plate (8) to at least two differently positioned tie bars (6) of a clamping unit of a molding machine, comprising: - at least two locking nuts having a height (H), each assigned to one of the differently positioned stiles (6) and each having at least a first and a second nut part (5, 5'), wherein at least approximately at half the height (H) of the locking nuts an imaginary plane (E) runs perpendicular to a longitudinal axis of the locking nuts extending over the height (H). - a rotatably arranged synchronization element (2) - at least two rods (1, 3), wherein a first nut part (5) of one of the at least two locking nuts and a second nut part (5') of another of the at least two locking nuts are pivotally connected to the synchronization element (2) via one of the at least two rods (1, 3). - at least two synchronization rods (12), wherein a second nut part (5') of one of the at least two locking nuts and a first nut part (5) of the other of the at least two locking nuts are connected to each other via one of the at least two synchronization rods (12), characterized by - a linear drive (4) which is connected to the synchronization element (2) eccentrically via a pivot joint (13) on the one hand for rotating the synchronization element (2) and is mounted on the other hand on the locking nut, preferably the first or second nut part (5, 5'), wherein the linear drive (4), the synchronization element (2) and the at least two rods (1, 3) are aligned relative to the imaginary plane (E) in such a way that a force exerted by the linear drive (4) via the synchronization element (2) on the nut parts (5, 5') connected to the at least two rods (1, 3) is in or symmetrical to the imaginary plane (E).

Description

[0001] The present invention relates to a locking device for locking a mold mounting plate to at least two differently positioned tie bars of a clamping unit of a molding machine, a clamping unit for a molding machine with such a locking device and a molding machine with such a clamping unit.

[0002] DE 10 2012 000 741 B4 and DE 10 2012 025 759 B3 each disclose such a locking device, such a closing unit and such a forming machine, comprising: - four locking nuts of a certain height, each assigned to one of four differently positioned stiles and each having a first and a second nut part - a rotatably arranged synchronization element for two locking nuts each - at least two rods for each synchronization element, wherein a first nut part of one of the locking nuts and a second nut part of another of the locking nuts are pivotally connected to one of the synchronization elements via one of the at least two rods. - four synchronization rods for two locking nuts each, wherein a second nut part of one locking nut and a first nut part of the other locking nut are connected to each other via two of the four synchronization rods each. - a rotary drive aligned parallel to the heights of the locking nuts for each of the two synchronization elements

[0003] A locking device of a different design type is in the Fig. Figures 8 to 10 of DE 200 06 618 U1 show this. A linear drive in the form of a hydraulic piston-cylinder unit is provided for rotating the synchronization elements, wherein the synchronization rods, the synchronization elements and the linear drive are arranged in different imaginary planes (which run perpendicular to a longitudinal axis of the locking nuts extending over the height).

[0004] Further embodiments known from the prior art are described in KR 10 1 335 037 B1, DE 21 00 868 A or CN 1 11 152 426 A.

[0005] The current state of the art exhibits the problem of so-called "nut tilting." This occurs when the ends of the locking nuts furthest from the plate tilt towards the respective frame, causing excessive wear.

[0006] The object of the invention is to provide a locking device for locking a mold mounting plate to at least two differently positioned tie bars of a clamping unit of a molding machine in which the problem of nut tilting is at least reduced, preferably eliminated, compared to the prior art, and to provide a clamping unit for a molding machine with such a locking device and a molding machine with such a clamping unit.

[0007] This problem is solved by a locking device having the features of claim 1, a clamping unit for a forming machine with such a locking device, and a forming machine with such a clamping unit. Advantageous embodiments of the invention are defined in the dependent claims.

[0008] Because it is designed that the linear drive, the synchronizing element, and the at least two rods are aligned relative to the imaginary plane such that the force exerted by the linear drive via the synchronizing element on the nut parts connected to the at least two rods is in or symmetrical to the imaginary plane. The closer the imaginary plane is to half the height of the locking nuts, the less nut tilting occurs. If the imaginary plane is exactly at half the height of the locking nuts, no nut tilting occurs at all.

[0009] The use of a linear drive results in a reduced size compared to the use of a rotary drive arranged on the axis of the synchronization element.

[0010] The locking in the locked state can be achieved in a known manner by pressing grooves, slots or teeth arranged on the nut parts against complementary sections of a pilaster.

[0011] It may be provided that, in the event of a rotation of the synchronization element in a first direction of rotation caused by the linear drive, - the first nut part of one of the at least two locking nuts and the second nut part of the other of the at least two locking nuts are movable towards each other. and at the same time - the second nut part of one of the at least two locking nuts and the first nut part of the other of the at least two locking nuts are movable away from each other. and in the event of a rotation of the synchronization element in a second direction of rotation caused by the linear drive - the second nut part of one of the at least two locking nuts and the first nut part of the other of the at least two locking nuts are movable towards each other. and at the same time - the first nut part of one of the at least two locking nuts and the second nut part of the other of the at least two locking nuts are movable away from each other.

[0012] Rotation in one of the two directions of rotation causes the nut parts to be moved into a locked state, while rotation in the other of the two directions of rotation causes the nut parts to be moved into an open state.

[0013] It is preferably intended that - one of the rods is mounted together with the linear drive at a nut connection and together with the linear drive and the synchronization element forms an imaginary triangle, at least in the locked state, which lies in the imaginary plane, or - one of the rods is connected to the linear drive via a drive connection and, together with this and the synchronization element, forms an imaginary polygon of order greater than or equal to four (e.g., a square or pentagon) at least in the locking state, which lies in the imaginary plane

[0014] Both measures ensure that the rods do not fully extend even when the locking device is locked, thus always maintaining a reserve for a locking movement. Furthermore, this results in favorable kinematics, as the movement of the nut parts slows down near the locked position, making it preferentially unnecessary to provide a damping device without adversely affecting noise levels or causing damage to the nut parts due to excessively rapid impact.

[0015] The linear drive can be dimensioned with a lower power output.

[0016] The linear actuator can be designed as a hydraulic piston-cylinder unit, an electric linear actuator, or similar. If it is ensured that the rods do not extend fully in the locked position, a check valve can prevent the flow of hydraulic oil in the locked position in the case of a hydraulic piston-cylinder unit, thus preventing the hydraulic pump supplying the hydraulic piston-cylinder unit from having to continuously generate pressure in the locked position.

[0017] It is preferably provided that the at least two synchronization rods are arranged symmetrically to each other relative to the height of the locking nuts and preferably in edge regions of the nut parts.

[0018] In one embodiment of the invention, it is provided that one of the rods (of the at least two rods for each synchronization element, wherein a first nut part of one of the locking nuts and a second nut part of another of the locking nuts are pivotally connected to one of the synchronization elements via one of the at least two rods) is formed by the linear drive itself.

[0019] The locking device according to the invention is preferably used in a two-plate locking unit.

[0020] Preferably, in a locking unit according to the invention, a separate energy source or energy storage device is provided for driving the locking device, so that a movement of one of the mold mounting plates and a driving of the locking device can be carried out independently of each other.

[0021] It may be provided that an energy storage device for supplying the linear drive of the locking device is arranged on the mold mounting plate on which the locking device is mounted. In the case of a linear drive in the form of a hydraulic piston-cylinder unit, the energy storage device may, for example, be a hydraulic pressure accumulator; in the case of a linear drive in the form of an electric actuator, the energy storage device may, for example, be an electric battery.

[0022] In a closing unit according to the invention, it is preferably provided that a locking device with four locking nuts is arranged on a mold mounting plate, wherein a common synchronization element is provided for every two locking nuts.

[0023] It may be provided that either - a separate linear drive is provided for each of the two synchronization elements, or - a common linear drive is provided for both synchronization elements, by which an actuating lever connecting the two synchronization elements can be driven.

[0024] Examples of forming machines include injection molding machines, especially plastic injection molding machines, injection presses and injection compression molding machines.

[0025] Exemplary embodiments of the invention are discussed with reference to the figures. They show: Fig. 1 a top view of a forming machine according to the invention along a longitudinal axis of the forming machine Fig. 2 a side view of the forming machine shown in the preceding figure Fig. 3 an isometric view of the mold mounting plate visible in the two preceding figures in isolation Fig. 4 An embodiment of the locking device according to the invention in the locked position Fig. 5 the embodiment shown in the preceding figure in the unlocked position Fig. 6 a side view of Fig. 4 Fig. 7-9 figures analogous to the Fig. 4 to 6 to a further embodiment of the locking device Fig. 10 a top view of a part of a forming machine according to the invention Fig. 11 - 13 analogous to the preceding figure for further embodiments Fig. 14 a top view of a part of a forming machine according to the invention in a further embodiment Fig. 15 a top view of a part of a forming machine according to the invention in a further embodiment

[0026] The Fig. Figures 1 to 3 show a clamping unit of a forming machine according to the invention (here in the form of a plastic injection molding machine, the injection unit not being shown as it corresponds to the prior art). The clamping unit is designed as a two-platen clamping unit with a mold mounting plate 8 fixedly connected to a machine bed 7 (in Fig. 2 right) and a mold mounting plate movable relative to the machine bed 7 (in Fig. 2 (left). Rapid-closing cylinders 11 are provided for a rapid lifting operation. The closing force is generated via pressure cushions 10.

[0027] To supply the linear drives 4, which are designed here as hydraulic piston-cylinder units, a hydraulic pressure accumulator 9 is provided on the mold mounting plate 8, which can be charged via a hydraulic system of the clamping unit (not shown).

[0028] Two locking devices are provided for locking a mold mounting plate 8 to a total of four differently positioned tie bars 6 of the molding machine. Each of the locking devices has: - two locking nuts having a height H, each assigned to one of the differently positioned stiles 6 and each having a first and a second nut part 5, 5', wherein at half the height H of the locking nuts an imaginary plane E runs perpendicular to a longitudinal axis of the locking nuts extending over the height H - a synchronization element 2 rotatably arranged on the mold mounting plate 8 via a bolt 17 - two rods 1, 3, wherein a first nut part 5 of one of the locking nuts and a second nut part 5' of another of the locking nuts are pivotally connected to the synchronization element 2 via one of the two rods 1, 3 - four synchronization rods 12, wherein a second nut part 5' of one locking nut and a first nut part 5 of the other locking nut are connected to each other via two synchronization rods 12 - a linear drive 4, which is eccentrically connected to the synchronization element 2 via a rotary joint 13 for rotating the synchronization element 2

[0029] As can be seen in particular from the descriptions of the Fig. 4 and Fig. 5 (these are mirrored to each other, and shown once open and once closed) show that when the synchronization element 2 is rotated in a first direction of rotation by the linear drive - the first nut part 5 of one of the at least two locking nuts and the second nut part 5' of the other of the at least two locking nuts can be moved towards each other and simultaneously - the second nut part 5' of one of the at least two locking nuts and the first nut part 5 of the other of the at least two locking nuts can be moved away from each other and in a second direction of rotation caused by the linear drive of the synchronizing element 2 - the second nut part 5' of one of the at least two locking nuts and the first nut part 5 of the other of the at least two locking nuts can be moved towards each other and simultaneously - the first nut part 5 of one of the at least two locking nuts and the second nut part 5' of the other of the at least two locking nuts can be moved away from each other

[0030] The movement of the nut parts 5, 5' of the different locking nuts that are arranged closer to each other is effected by the rods 1, 3. The movement of the nut parts 5, 5' of the different locking nuts that are further apart is effected by the synchronization rods 12, wherein two synchronization rods 12 connect the nut parts 5 of the different locking nuts that always move in the same direction, and two synchronization rods 12 connect the nut parts 5' of the different locking nuts that always move in the same direction (in the Fig. 4 and Fig. In 5 only one synchronization rod 12 is visible, cf. but Fig. 6).

[0031] In Fig. Figure 4 shows the locked state of the locking nuts. Fig. Figure 5 shows the open state of the locking nuts.

[0032] Guide pieces 16 are provided for the translational guidance of the mother parts 5, 5'.

[0033] A drive rod 15 of the linear drive 4 (which here is designed as a hydraulic piston-cylinder unit) is connected to the joint 13 that connects the synchronizing element 2 to one of the rods 3. In this embodiment, a piston receiving the drive rod 15 is mounted on a drive connection 19 formed on the other rod 1, so that the linear drive 4 can move with the rods 1 and 3. The linear drive 4, the synchronizing element 2, and the rod 1 together with the drive connection 19 are arranged in the form of an imaginary quadrilateral lying in the imaginary plane E.

[0034] The in the Fig. The embodiment shown in Figures 7 to 9 differs from this in that the piston is not pivotally mounted on the other rod 1, but directly on one of the nut connections 14. The linear drive 4, the synchronizing element 2, and the rod 1 are arranged in the form of an imaginary triangle lying in the imaginary plane E.

[0035] In the exemplary embodiment of the Fig. 10 is different from that of the Fig. 4 to 6 the drive rod 15 of the linear drive 4 is not connected to the rod 3, but to a cam part of the synchronization element 2 in a pivotal manner.

[0036] Such a measure is also taken in the exemplary embodiment of the Fig. 11, however, rod 1 is also shorter and, compared to the Fig. The missing length of 10 is compensated for by a lever part of the synchronization element 2. Here, the linear drive 4, the synchronization element 2, and the rod 1 together with the drive connection 19 form an imaginary pentagon, which lies in the imaginary plane E.

[0037] The linear drive 4, the synchronizing element 2, and the two rods 1, 3 are aligned relative to the imaginary plane E (which is located here at half the height H / 2) such that the force exerted by the linear drive 4 via the synchronizing element 2 on the nut parts 5, 5' connected to the rods 1, 3 is symmetrical to the imaginary plane E (see the illustration of the Fig. 6) via the tabs arranged symmetrically to the imaginary plane E of a nut connection 14 provided with the respective nut part 5, 5' (the pivot pins of the nut connections 14 are located on the rods 1, 3). In contrast to the illustration, the tabs of the nut connection 14 could be provided on the rods 1, 3 and the pivot pin arranged on the respective nut parts 5, 5'.

[0038] The difference in the exemplary embodiments of the Fig. The difference between 10 and 13 lies in the design of the synchronization elements 2, which results in a different connection point for the linear drive 4 and consequently different strokes of the linear drive 4. This changes the speed profile of the entire kinematic system as well as the start and end positions (open and closed state) of the various levers.

[0039] In the exemplary embodiment of the Fig. 14 only one common linear drive 4 (please show) is provided for both locking devices, wherein the drive of the synchronization elements 2 is carried out via an actuating lever 18.

[0040] In the exemplary embodiment of the Fig. 15 is one of the rods 1, 3 formed by the linear drive 4 itself.

[0041] In all embodiments, a particularly preferred arrangement of the synchronization rods 12 is shown, in which the synchronization rods 12 are arranged symmetrically to each other relative to the height H of the locking nuts and preferably in edge regions of the nut parts 5, 5'.

[0042] The different geometric configurations of the rods 1, 3, the synchronization element 2 and the linear drive 4 shown in the figures allow for different desired kinematic trajectories of the movement of the nut parts 5, 5' to be achieved. Reference symbol list: 1 bar 2 Synchronization element 3 bars 4 Linear actuators 5 first mother part, 5' second mother part 6 Holm 7 Machine bed 8 Mold clamping plate 9 hydraulic pressure accumulators 10 pressure pads 11 quick-closing cylinders 12 Synchronization rod 13 joint 14 nut connection 15 Drive rod 16 guide piece 17 bolts 18 operating levers 19 Drive connection H Height of the locking nut E imaginary plane through locking nut

Claims

[1] Locking device for locking a mold mounting plate (8) to at least two differently positioned tie bars (6) of a clamping unit of a molding machine, comprising: - at least two locking nuts having a height (H), each assigned to one of the differently positioned stiles (6) and each having at least a first and a second nut part (5, 5'), wherein at least approximately at half the height (H) of the locking nuts an imaginary plane (E) runs perpendicular to a longitudinal axis of the locking nuts extending over the height (H). - a rotatably arranged synchronization element (2) - at least two rods (1, 3), wherein a first nut part (5) of one of the at least two locking nuts and a second nut part (5') of another of the at least two locking nuts are pivotally connected to the synchronization element (2) via one of the at least two rods (1, 3). - at least two synchronization rods (12), wherein a second nut part (5') of one of the at least two locking nuts and a first nut part (5) of the other of the at least two locking nuts are connected to each other via one of the at least two synchronization rods (12). characterized by - a linear drive (4) which is connected to the synchronization element (2) eccentrically via a pivot joint (13) on the one hand for rotating the synchronization element (2) and is mounted on the other hand on the locking nut, preferably the first or second nut part (5, 5'), wherein the linear drive (4), the synchronization element (2) and the at least two rods (1, 3) are aligned relative to the imaginary plane (E) in such a way that a force exerted by the linear drive (4) via the synchronization element (2) on the nut parts (5, 5') connected to the at least two rods (1, 3) is in or symmetrical to the imaginary plane (E). [2] Locking device according to the preceding claim, wherein one of the rods (1, 3) is mounted together with the linear drive (4) on a nut connection (14) and together with the linear drive (4) and the synchronization element (2) forms an imaginary triangle at least in the locking state which lies in the imaginary plane (E). [3] Locking device according to claim 1, wherein one of the rods (1, 3) is connected to the linear drive (4) via a drive connection (19) formed on the synchronization element (2) and together with the linear drive and the synchronization element (2) forms, at least in the locking state, an imaginary polygon of order greater than or equal to four, which lies in the imaginary plane (E). [4] Locking device according to at least one of the preceding claims, wherein the at least two synchronization rods (12) are arranged symmetrically to each other relative to the height of the locking nuts and preferably in edge regions of the nut parts (5, 5'). [5] Locking device according to at least one of the preceding claims, wherein one of the rods (1, 3) is formed by the linear drive (4) itself. [6] Locking unit, in particular a two-plate locking unit, with a locking device according to at least one of the preceding claims. [7] Locking unit according to the preceding claim, wherein a separate energy source or energy storage device is provided for driving the locking device, so that a movement of one of the mold mounting plates (8) and a driving of the locking device can be carried out independently of each other. [8] Locking unit according to the preceding claim, wherein an energy storage device for supplying the linear drive (4) of the locking device is arranged on the mold mounting plate (8) on which the locking device is arranged. [9] Locking unit according to at least one of claims 6 to 8, wherein a locking device with four locking nuts is arranged on a mold mounting plate (8), wherein a common synchronization element (2) is provided for each pair of locking nuts. [10] Closing unit according to the preceding claim, wherein either - a separate linear drive (4) is provided for each of the two synchronization elements (2), or - a common linear drive (4) is provided for both synchronization elements (2), by which an actuating lever (18) connecting the two synchronization elements (2) can be driven [11] Forming machine with a clamping unit according to at least one of claims 6 to 10.

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