|Title of Invention||
"A MOULD LOCKING UNIT"
|Abstract||This invention relates to a mould locking unit for an injection moulding machine having a short working stroke and a longer service stroke, particularly for production of disc-shaped parts, comprising a drive carrier plate (15) with at least one-electro-motoric servo shaft, whereby the drive carrier plate (15) can be locally connected on the side with a machine stand (8) of the injection moulding machine, or can be moved relative to a nozzle-end tool clamping plate.|
This invention relates to a mold locking unit Tor an injection molding machine having a short working stroke and a longer servicing stroke, especially for production of disc-shaped parts.
STATE OF THE ART
In injection molding of flat parts such as compact discs, the opening Stoke for the production cycle of the Injection molding machine should be kept only as large as necessary for unmolding. Such compact discs are a few millimeters thick. Thus, theoretically, an opening slightly larger than 1 cm would be sufficient. Recent trends have in fact been toward short strokes of 30 to 50 mm to minimize the so called dry run time. In changing molds, however the opening width must be increased relatively rapidly up to approx. 300 mm. This operation is known as a servicing stroke.
The data carriers known today as CDs have gained a key position in the economy and in also in the private sector that can no longer be overlooked. Digitized storage of data plus audio and video has set completely new standards. There are already known CDs which have a very high data density as well as new multilayer technologies with up to two information layers. MO (magnetic optical), CD-R (writable once, for photos, computer data, music/video recordings), CD-RW (multiply writable, for computer data and music recordings, video sequences), music CDs and CD-ROM. The constant increase in date volume and the associated data compression as well as the data storage technologies developed along with them demand ever greater precision, reproducibility and long-term stability iii the molding operations. This in turn makes maximum demands of the control rule accuracy of speeds, pressures, forces and
moulding machines are dependent on force transmitting systems for generating the locking force, like: ball spindle, toothed rack, lever systems etc., which e.g. a double toggle, strengthens the force on the joined head or cross head by a factor of say 24 to 50, in order to generate the locking force. Present day electro - mechanical injection moulding machines with toggle systems are however not suitable for short working strokes, because in that case the lubrication of the joint bolts can no longer be guaranteed. While working with fully hydrauficafly driven injection moulding machines, on the other hand, strokes of 70mm conform to the state - of - the - art technology,
OE 3244300 discloses an injection moulding machine which although has a short working stroke but does not have a longer service stroke. The drive carrier plate of the machine does not carry any electric motor. Thus, the machine of the cited reference is not capable of producing disc -- shaped parts.
PRESENTATION OF THE INVENTION
It is the task of this invention to develop a combination for short stroke - long stroke, which allows the highest possible productivity and quality as well as the least dry run time for production of flat parts. It further has the goal for developing a machine in as compact a structure as possible using one, two or more cavities, particularly even for a clean room usage.
The solution as per the invention has a special feature, that it has a drive carrier plate with atleast one electro - motoric servo axis, whereby the driver carrier plate is either fixed, can be joined on the end side with the machine stand of the injection moulding machine, or is movable relative to the nozzle - side tool clamping plate.
It has been recognized by the inventors that an optimum application for electro -mechanical driving agents, particularly also with respect to clean room viability can be guaranteed only when this is locally defined by a drive carrier plate, instead of dividing the driving agents of two carrier plates which is the case presently in the most successful hydraulic CD - machine.
This new solution opens up totally new design forms for the short stroke or the working stroke as well as for the long stroke or service stroke. A first design version has the feature, that for the short stroke it has an electro - motoric crank drive with ideally one servo motor, over which the movable tool clamping is quickly opened for the working stroke and can be closed. The crank drive has an eccentric shaft as well as two parallely arranged crank levers which can be driven by a asynchronous motor and symmetrically grip on to the movable mould plate. The movable tool clamping plate and the crank drive form in this way a compact assembly and are anchored on the drive carrier plate, whereby the movable tool clamping plate is guided on a guide. The enormous advantage obtained from a compact assembly consisting of the movable clamping tool plate and the crank device is primarily in the production of a total machine. The assembly allows the economic assembly mounting. If all elements within an assembly are produced with highest precision and adapted, then inspite of very short assembly time one gets the highest precision even for total functioning as one can fall back on the inner precision of the assembly group. The crank device can be optimally utilized over an eccentric shaft in the crank functioning, as purely impact function with the maximum required locking force and can be used in the corresponding dead point range of the crank for 100% release of the prior driving agents of their bearings. The maximum possible forces from the side of the mould locking get reduced to purely static support forces which actually can be easily overcome. A not significant advantage also lies in the fact, that not only can arbitrarily short working strokes be run.
The short stroke is held in the closed position of the crank drive atleast approximating towards the dead point position. On the other hand, for the open position outside the dead point position, it can be stopped at any desired point for reducing and optimizing the dry run time. For ensuring the maximum possible locking force or locking position, the crank drive runs atleast always approaching towards a fixed pre-selected optimum position. Changing mould thickness, e.g. conditioned by temperature, are set by means of position corrections of the nozzle - side tool clamping plate.
According to a second design version, the locking unit has the feature, that for the service stroke it has an electro - motoric column nut drive, over which a nozzle - side tool clamping plate is movable for the service stroke, relative to the drive carrier plate. Absolutely ideal would be if the columns themselves were driveable and the nozzle - side tool clamping plate is designed to be movable with the nuts supported on it. Thus the drive carrier plate becomes literally what the term expresses. The corresponding end plate becomes a carrier for the drives which are joined fixed to the machine stand. This immediately brings several advantages. The static forces can be closed on the shortest path. The highly dynamic forces are detoured or steered only from one side, i. e. only from the drive carrier plate. In this way, possible swing sequences could be better controlled or compensated and a simultaneous intervention even for corrections
can be ensured
The rotation drive of all columns takes place centrally through a cogged belt drive or a ring gear. It is further suggested that the central column nut drive be designed as controlling
5 EXPLANATION OF THE INVENTION
The object of this invention is to develop a short stroke/long-stroke combination which will allow the greatest possible productivity and the highes: quality as well as the shortest possible dry run time for production of flat parts. Another goal is to develop a machine with the most compact possible design using one, two or more cavities, in particular also for use in a clean room.
This object is achieved according to this invention by the fact that it has a drive carrier plate having at least one electric motor servo axle, where the drive carrier plate can be connected to the machine stand of the injection molding machine in a stationary position at the end or it may move relative to the mold backing plate on the nozzle end.
The inventors have recognized that optimum use of electromechanical driving means, especially with regard to suitability for use in a clean room, can be guaranteed in particular if they are defined locally starting from a drive carrier plate instead of dividing the drive means between two carrier plates, as is the case currently with the most successful hydraulic CD machine.
This new solution permits some entirely now designs for both the short stroke or the working stroke and the long stroke or servicing stroke. A first embodiment is characterized in that it has an electric motor crank mechanism, preferably with a servo motor for the short stroke, by means of which a movable mold backing plate can be opened and closed quickly for the working stroke. The crank mechanism has an eccentric shaft and preferably two crank levers arranged in parallel, driven by a synchronous or asynchronous motor and acting symmetrically on the movable mold plate. The movable mold backing plate and the crank mechanism thus form a compact module anchored on the drive carrier
plate, with the movable mold backing plate being guided on a guide. The enormous advantage achieved with a compact module consisting of the movable mold backing plate together with the crank mechanism is to be seen first of all in the production of an entire machine. The module permits economical modular assembly. If all the elements within one module are manufactured and fitted with the highest precision, this yields the highest precision for the overall functioning as well, despite the very short assembly time, because it can be based on the internal precision of the module. The crank mechanism can be utilized optimally in the crank function, as a pure impact function at the maximum required closing force by means of an eccentric shaft, and in the corresponding dead center range, the crank can be used for 100% unloading of the driving means or their bearings before this range. The greatest possible forces from the standpoint of mold closing can be reduced to purely static supporting forces which are more easily controlled per se. A not insignificant advantage is derived from the fact that not only any desired slot working strokes can be used, but also the short stroke is kept at least approximately in the dead center position when the crank mechanism is in the closed position. For the open position, however, it can be stopped in any desired position outside the dead center position to shorten and optimize the dry run time. To ensure the greatest possible closing force or the largest possible closed positions, the crank mechanism always moves at least approximately into a fixed preselected optimum position. Variations in mold thickness such as those due to temperature, for example, are adjusted by correcting the position of the mold backing plate on the nozzle end.
According to a second embodiment of this invention, the mold closing unit is characterized in that it has an electric motor column-type nut drive for the servicing stroke by means of which a mold backing plate on the nozzle end can be moved relative to the drive carrier plate for the servicing stroke. It is
especially preferable here for the columns themselves to be drivable and for the mold backing plate on the nozzle end with the nuts mounted on it to be designed to be movable. Thus, the drive carrier plate becomes what is indicated by the phrase to the full sense of the term. The corresponding end plate becomes a carrier for the drives and is preferably fixedly connected to the machine stand. This brings several advantages at once. The static forces can be closed in the shortest distance. The highly dynamic forces are diverted or controlled from only one side, namely only from the drive carrier plate. In this way, possible vibrational processes can be kept under control more easily or compensated, while access can be ensured at the same time, even for corrections.
The rotational drive for all columns takes place centrally, preferably by means of a toothed belt drive or a rim gear. It is also proposed that the central column-type nut drive should be designed as a final controlling element of the closing force regulation together with a force sensor arranged on a machine part as an actual value generator for detection of the closing force and a control device. Position detection of the stroke movement takes place advantageously by means of position detection in the servo motors themselves. These reproducible positions are used by the control/regulation and coordination of the various axles, e.g., also for control/regulation and synchronization of the actuation of the removing device and the mold closing axle. The control/regulation device is designed as a central adjustment for the servicing stroke and the working stroke with the required memories for storing formulations and programs. The control/regulation device is equipped for precise, coordinated control/regulation of the servo axles for the short stroke as well as the long stroke and with corresponding servo boosters for synchronous or asynchronous motors. It is important here that it has at least one independently controllable drive motor, preferably a servo motor for the working stroke and the servicing stroke. In the normal case, both drive sides are designed electromechanically for the working
stroke and for the servicing stroke, with the direction of impact of the crank mechanism being arranged at least approximately symmetrically inside the column axles. The movable mold backing piate and the moid backing plate on the nozzle end are guided on a common guide. The column-type nut drive has at least three driven columns, preferably four, with the overdrive for the three or four columns being arranged on the outer end of the drive carrier plate and the overdrive for the crank mechanism being arranged on the inner end of the drive carrier plate.
In a modification of the possible embodiments described above, the mold plates, e.g., also the short-stroke carrier plate and the long-stroke carrier plate, may each be designed as selectable fixed mold plates or movable mold plates for very specific applications, with a nut drive having a central axial drive again being provided here for the relative movement of the plates. All the movement functions are primarily movements of the components relative to one another and only secondarily are they movements of the components relative to the stationary machine stand. For example, if the long-stroke carrier piate is fixedly anchored on the machine stand, the movement functions of the injection end must be adapted and coordinated accordingly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
This novel solution will now be illustrated on the basis of a few embodiments with additional details, showing:
FIG. 1 an overall view of one solution according to the state of the art, specialized for production of compact discs (CDs);
FIG. 2 an example of a novel solution in a perspective diagram;
FIG. 3 the main elements of a short-stroke drive as another embodiment;
FIG. 4 a schematic diagram of a sectional view of a three-column machine along line IV--IV in FIG. 3;
FIG. 5a the theoretical force diagram at the end of the closing movement and in the buildup of the closing force:
FIG. 5b function of position and angle of rotation for the crank mechanism;
FIG. 6a a view of FIG. 2 from the rear according to arrow VI;
FIG. 6b a view of from above in FIG. 6a according to arrow VI;
FIG. 7 a section VII--VII from FIG. 6b;
FIG. 8a a crank mechanism shown in a schematic diagram;
FIG. 8b a view according to arrow IIX in FIG. 8a;
FIG. 9 a section IX--IX in FIG. 6a;
FIG. 10 an example of a central drive of the columns by a V-belt;
FIG. 11 the mounting of a column;
FIG. 12 an example of a mold having two cavities.
METHOD OF THE EMBODIMENT OF THE INVENTION
This novel solution makes it possible to design an entire machine for use in a clean room and to combine the advantages of machines equipped with a toggle system as well as those of machines equipped with fully hydraulic mold closing. An important advantage of the novel solution is that the dry run time can be designed to be extremely short, e.g., less than 0.3 second. In addition, even in the servicing stroke, movement with an accuracy in the micrometer range (thousandths of a millimeter) is guaranteed, so that the reproducibility of the closing movement operation, once it has been set, is fully guaranteed. The crank mechanism or eccentric drive also has the enormous advantage that the working stroke can be as small as desired, e.g., a crank radius of approx. 25-35 mm can be achieved easily.
With the solution according to FIG. 1, a CD can be produced in 3.7 seconds or less with the known state of the art. The known solution by the present applicant is a fully hydraulic machine 10 having very good properties with respect to machine stability, and it has three columns. The short stroke is 70 to 80 mm and the closing force is approx. 600 kN. The servicing stroke is a total of about 300 mm. Mold piate 1 is fixedly connected to a machine stand 8. Tension rods 2 are bolted to the mold plate 1, with a piston head 3 being arranged inside a cylinder 4 on the other end of the tension rod 2. The mold plate 5 is shown in a production position, with the piston head 3 constantly pressing against a shoulder or the tension rod 2. The force applied exceeds the closing force. With a relatively low force, a closing piston moves forward and in reverse by means of two auxiliary cylinders over the entire short stroke. The corresponding oil pressure is applied in a piston chamber only for application of the large closing force. For changing a stamper in the mold, the three cylinders are driven on the tension rods, and the mold plate 5 opens to the extent of the servicing stroke.
The machine 10 is shown with the safety door 6 opened, with a view of the mold closure and the injection cylinder 7. The raw material is supplied through filling tank 9.
FIG. 2 shows a perspective view of an example of the novel solution having four columns driven by toothed belts. FIGS. 3 and 4 show another example of the novel solution having three columns. On the left side of the figure can be seen the mold backing plate on the nozzle end or the long-stroke carrier plate 11 with one mold half 12 toward which the injection nozzle moves back and forth according to arrows 13. The long-stroke carrier plate 11 may be in a stationary mount or it may be arranged movably on the machine stand 8, depending on the design select d. The right side of the figure shows, for example, a crank mechanism a a compact modular unit 14. Modular unit 14 consists of a drive carrier plate 15 and a movable mold backing plate 16 which rests on the machine bed S on a guide 55 and a crank carrier structure 17. A crank mechanism 18 is mounted in an articulated manner on one end by a bolt 19 and the movable mold backing plate 16 and on the other end by a cam 21 in the crank carrier construction 17 in such a way that the crank 22 can execute the crank movement in accordance with an eccentricity e. Eccentricity e corresponds to half the stroke height (H/2). On the opposite end of the movable mold backing plate 16 is one mold half 23. Cavity 24 for insertion of the desired discshaped part is formed when the two mold halves 12 and 23 are closed. Usually, however, the CD is not cast directly in cavity 24 but instead a stamper 25, 26 having the negative mold for the CD is inserted into the cavity on one or both sides.
The movement of the mold half 12 relative to the carrier plate 15 essentially corresponds to what is known in the state of the art. The anchoring and holding force between the two plates is ensured by three columns (i.e., screws) (FIG. 4)
or optionally four columns (i.e., screws) 30 according to FIG. 2. Each column 30 is anchored on the mold backing plate 11 on the nozzle end by means of a nut 31. A rotationally movable collar 32 is secured on the drive carrier plate 15 and engages by means of a rim gear 33 in a toothed ring 34 (FIG. 4). The fixed nut 31 engages with the thread 35 on each column (i.e., screw) by means of an inside thread. A rotational movement of the rim gear or the toothed belt is converted by the rotation of the columns on nut 31 and thread 35 of the columns into a linear movement (arrows 36) of the mold backing plate 11 on the nozzle end. This movement represents the long stroke or servicing stroke and is needed primarily changing stampers quickly. The short working stroke, however, is executed by the crank mechanism 18 and the movable mold backing plate 16. FIG. 4 shows schematically the drive or overdrive for the column nuts and the long stroke with electric motor 40 having drive pinion 41 and the drive for the short stroke by means of an electric motor 42, a gear 43 and cam 21. The injection unit and the plastifying cylinder are assigned to the mold backing plate 11 on the nozzle end, and both electric motor drives are assigned to the other fixed carrier plate. The servicing stroke is operated with an essentially known "mold structural height adjustment" by means of a rim gear and gear wheels on the column nuts. As an alternative, the rotation of the columns can be implemented with a toothed belt. Higher adjustment rates and thus set-up times of less than 30 seconds can be achieved when changing the dies (stampers) due to the mounting of the columns with roller bearings in the mold plates and lubrication of the bearings and the adjusting thread. Therefore, it is also novel that an accurately positionable electric motor, preferably a servo motor with a gear with a low play, is also used for this drive. Between the crank mechanism and the electric drive motor, there is a gear, preferably a spur gear. C indicates a control/regulation intelligence with a memory which selects the required program sequences or formulations for the corresponding motor control/regulation. R1, R2, R3, etc. in box C indicate that any desired computation power can be
installed directly on-site and corresponding coordinations can be carried out directly. Accordingly, the control connections St1, St2, St3 may be provided, and a corresponding optimization of all control and regulatory sequences can be
Solid line 45 in FIG. 5a shows the theoretical force curve at the end of the closing movement. The bold line 44 shows the effective force curve on both halves of the mold on the basis of Hook's characteristic lines of deformation of the columns and plates in the case of a CD closing unit with a 50 mm opening distance. The lower line 46 in FIG. 5b shows the rate curve, and line 47 shows the path of movement of the cam for a CD mold closure.
Reference is made to FIGS. 6a and 6b below, showing a view from the side and from above (FIG. 6b). At the left side of the figure can be seen a drive carrier plate 50 with a module 51 for the working stroke of short stroke bolted tightly to it directly by connecting means 52 on the right. A mold backing plate 53 on the nozzle end is shown in the right half of the figure. The mold backing plate on the nozzle end is held by four columns 54 with respect to the drive carrier plate 50 and is guided at the lower end on a guide 55. Each of the four columns 54 is mounted by means of a column nut 63 in the mold backing plate 53 on the nozzle end in such a way that a rotational motion of the column axle yields a longitudinal displacement of mold half 12. In order for the column axle 56 not to become soiled due to generous lubrication of the high precision thread for the lowest possible friction, the column axle 56 is surrounded by a protective sleeve 57. The rotational motion of the column axles 56 is produced centrally by a toothed belt drive 58 and a drive motor or electric motor 40. The mold backing plate 53 on the nozzle end is guided with almost no play on both sides by means of friction blocks 62 for an accurate parallel guidance. Cam 21 is mounted freely so that the crank movement of crank mechanism 18 can be converted into a
linear motion without being hindered. Due to the movement of the mold backing plate 53 on the nozzle end by means of an appropriate rotational pulse on electric motor 42, the mold is opened widely, e.g., to a free clearance of 300 mm. The corresponding movement is indicated with arrow 64. Dt on the mold 12 indicates a thickness tolerance, e.g., due to changes in temperature of the molded body as a whole. If a correction is therefore necessary, it is detected automatically by the controller (change in closing force) and the position correction is implemented by the electric motor 40. The actual short stroke KH is executed merely by the cam movement over crank mechanism 19 and the obligatory horizontal linear motion of the movable mold backing plate 61. Another central function in production is removing the CD from the mold. FIG. 6b shows a CD removing robot 70 with a robot arm 71, a suction holding head 72 and a CD 73 held on it. The CD removing robot 70 has its own drive motor 74 and is fixedly connected to the machine bed as a removing unit 75. Complete coordination of the movement sequence of robot arm 71 and the short-stroke motion for opening the mold is important here. This coordination is in the millisecond range and is ensured through the use of suitable sensors, so there is no collision of moving parts under any circumstance.
FIG. 7 shows a section VII--VII in FIG. 6b. As explained above, the central column-type nut drive is preferably a final controlling element of the closing force control, which is used together with a force sensor as an actual value generator to detect the closing force, and a control device. The displacement measurement of the stroke movements takes place by means of a displacement measurement in the servo motor itself. The reproducible positions are used as the basis of the control/regulation and coordination of the various axles. To be able to guarantee the required accuracy after an adjustment of the servicing stroke, the bearing play and thread play required from a mechanical engineering standpoint are eliminated by a bias stress device 80 in each of the driven columns. The required
pressure to eliminate this play can be applied by means of springs or pneumatically, causing the play on the friction-engaged blank to be eliminated by means of a bias force between the support plate 15 and the mold plate 11. With cam 25, the cam radius is given as 25 mm only as an example, which would explain a total short stroke KH of 50 mm. The ejector device 81 will not be discussed in greater detail here. It may be designed with pneumatic operation, for example, and it may conform to the designs known in the state of the art.
FIGS. 8a and 8b show schematically the cam drive. The electric motor as servo motor 42 is arranged at the top, transmitting with its output shaft 82 and a pinion 83 the motion of the rotor from the servo motor 42 to an overdrive gear wheel 84 and by another pinion 85 to the driving gear wheel 86, which is fixedly mounted on the cam shaft 21. Cam shaft 21 is positively driven about the axle 87 of the driving gear wheel 86. The eccentric cam 21 is (driven) by the two roller bearings 88 in the bearing block 89. One bearing pin 90 with a rotational axle 91 projects on each side. The two crank arms 22 are mounted on the bearing pin 90 (FIG. 9) and generate a crank motion for the movable mold backing plate in accordance with the eccentricity Ex.
FIG. 9 shows in somewhat greater detail a horizontal section IX--IX from FIG. 6a. It can be seen here that cam 21 is freely mounted with respect to the drive carrier plate 50. The crank 22 is designed in duplicate, allowing a clearance between them for the entire ejector mechanism 81. It transmits the closing force uniformly, i.e., symmetrically, to the movable mold backing plate 61.
FIGS. 8, 9 and 10 each show an especially advantageous embodiment of the overdrive means. The term overdrive as used here is understood to refer to the technical gear means provided between the drive motor and the working parts to be given. A wide variety of means and transmission ratios can be used for the
overdrive to optimize the drive technology. The embodiments illustrated here are only examples
FIG. 10 shows a detail of a perspective view o the outer drive end of the drive carrier plate 50 for the central column nut adjustment. It is driven by an electric motor or servo motor 40 on which a toothed belt wheel 95 is arranged with tie toothed belt 96 running around it. The toothed belt 96 passes over the four belt overdrive wheels 97 as well as two bell tension wheels 98. This guarantees a precise drive of the four columns without any play.
FIG. 11 shows a section through a bearing journal 100 on the column axle 56. A gasket 101 or 102 is provided on the two outer sides This makes it possible to enclose grease lubrication in the interior of the bearing, so that here again, the requirement of a long lifetime and clean room use is guaranteed.
FIG. 12 shows in simplified form a dual cavity mold with two cavities 24, 24 accordingly for simultaneous production of the CDs. Through an appropriate design of the removal robot with a radius R, two or even more cavities may be provided, and CDs may optionally be removed on both sides (arrow 110). The angle of rotation depends on the specific relationships in each case.
1. Mould locking unit for an injection moulding machine having a short
working stroke and a longer service stroke, particularly for production
of disc-shaped parts, comprising
- a drive carrier plate (15) with at least one eletro-motoric servo
shaft, whereby the drive carrier plate (15) can be locally
connected on the side with a machine stand ( 8) of the injection
moulding machine, or can be moved relative to a nozzle-end
tool clamping plate.
2. Mould locking unit as claimed in claim 1, comprising
- an electro-motoric crank drive (18) with a servo motor for the
short stroke, through which a movable tool clamping plate (16,
61) can be opened and shut quickly for the working stroke.
3. Mould locking unit as claimed in one of the claims 1 or 2, wherein
- the crank drive ( 18) has an eccentric shaft and two parallely
arranged crank levers (22), which can be driven by a
synchronous or asynchronous motor and grip on symmetrically
to the movable tool clamping plate ( 16, 61).
4. Mould locking unit as claimed in one of claims 1 to 3, wherein the
short stroke in the closed position of the crank drive (18) holds prior
reaching the dead point position, and wherein for the open position of the crank drive (18) it holds outside the dead position, for optimization or reduction of dry run times.
5. Mould locking unit as claimed in one of the claims 1 to 4, wherein
- the crank drive (18) has a fixed given optimum crank position
for the locking position, and wherein the changing mould
thicknesses are adjusted by means of position corrections of a
nozzle-side tool clamping plate (16, 61).
6. Mould locking unit as claimed in one of the claims 1 to 5, comprising
- an electro-motoric column nut drive ( 96, 97, 98) for the service
stroke, through which a nozzle-side tool clamping plate ( 53) is
movable for the service stroke.
7. Mould locking unit as claimed in claim 6, wherein
- the columns ( 30, 54) are rotationally driveable and move the
nozzle -side clamping plate ( 53) over the nuts (31) supported
on them, and wherein each column ( 30, 54) has a pre-clamping
unit ( 20) for eliminating an axial clearance.
8. Mould locking unit as claimed in one of the claims 1 to 7, wherein the
rotation drive of the columns ( 30, 54) takes place by means of a
cogged belt drive ( 96) or a ring gear (33).
9. Mould locking unit as claimed in one of the claims 6 to 8, wherein the
bearing of the columns ( 30,. 54) is roller bearings.
10. Mould locking unit as claimed in one of the claims 1 to 9, wherein
the central column nut drive is used as a control member of the
locking force control, together with a force sensor for determining the
locking force and a regulating device, and wherein the path
determination of the stroke movements being carried out by means of
a path determination means in the servo motor, whereby the
corresponding rcproduceable position of control/regulation or
coordination of the various axes is taken as the basis.
11. Mould locking unit as claimed in one of the claims 1 to 10, comprising one independently controllable drive motor, designed as servo motor for the working and service stroke at least respectively whereby the control/ regulation device is designed as central adjustment for the service stroke and the working stroke, having the necessary storages for recipes or programmes.
12. Mould locking unit as claimed in one of the claims 1 to 11, comprising a control/ regulating device, for precise coordinated control of the regulation of the servo axes for the short stroke, and for the long stroke, whereby the servo axes with synchronous or
asynchronous motors, are equipped with corresponding servo amplifiers.
13. Mould locking unit as claimed in one of the claims 1 to 12, wherein both drive units ( 40, 42) are designed for working stroke and for service stroke electro-mechanically, whereby the impact direction of the crank drive (18) is arranged symmetrical within the column axes (56).
14. Mould locking unit as claimed in one of the claims 1 to 13, wherein
- the moving tool clamping plate (61) and the nozzle-side tool
clamping plate (53) are guided on a common guide on the
15.Mould locking unit as claimed in one of the claims 1 to 14, wherein
- the column nut drive (96, 97, 98) has at least three, preferably
four driven columns ( 30, 54) whereby the over drive for the
three or four columns is arranged on the outer end side of the
drive carrier plate (15) and the overdrive for the crank drive
(18) is arranged on the inner end side fo the drive carrier plate
16.Mould locking unit as claimed in one of claims 1 to 15, wherein
the mould plates can be selected as fixed mould plates or movable mould plates, whereby for the long stroke a nut drive with central axis drive is provided for the relative movement of the plates. 17.Mould locking unit as claimed in one of the claims 1 to 16, wherein
the control/ regulation is designed for synchronous activation of the removal device and the mould locking axis.
This invention relates to a mould locking unit for an injection moulding machine having a short working stroke and a longer service stroke, particularly for production of disc-shaped parts, comprising a drive carrier plate (15) with at least one-electro-motoric servo shaft, whereby the drive carrier plate (15) can be locally connected on the side with a machine stand (8) of the injection moulding machine, or can be moved relative to a nozzle-end tool clamping plate.
|Indian Patent Application Number||IN/PCT/2001/00932/KOL|
|PG Journal Number||06/2007|
|Date of Filing||10-Sep-2001|
|Name of Patentee||NETSTAL MASCHINEN AG.,|
|Applicant Address||OF INDUSTRIESTRASSE, CH-8752 NAFELS SWITZERLANDS A SWISS CO.|
|PCT International Classification Number||B 29C 45/17|
|PCT International Application Number||PCT/CH00/00069|
|PCT International Filing date||2000-02-09|