WO2001085423A1

WO2001085423A1 - Portable and independent support for compression moulding, especially for rim compression moulding

Info

Publication number: WO2001085423A1
Application number: PCT/EP2001/005090
Authority: WO
Inventors: Manfred Holzner; Andreas Karantonis; Wolfgang Fechter
Original assignee: Krauss-Maffei Kunststofftechnik Gmbh
Priority date: 2000-05-09
Filing date: 2001-05-05
Publication date: 2001-11-15
Also published as: DE10022324A1

Abstract

The invention relates to a portable and independent support (1) for compression moulding, especially for so-called RIM compression moulding in plastics technology. Said support (1) comprises an upper platen (9) which is fixed to the upper part (6) of the support and which can be pivoted about a horizontal axis (8) by electromotive means. Vertical guides (18, 19) on which the lower platen (16) can be vertically displaced and pivoted about a horizontal axis (28), by electromotive means, are provided on two opposite sides of the support (1). The invention is characterised in that the axis of rotation (28) of the lower platen (16) is centrally located and an electromotive drive device (29) is provided for pivoting. This enables the lower platen (16) to be pivoted in almost any vertical position in two directions. As a result, the production process can be configured more flexibly than has been the case up until now.

Description

Portable and self-sufficient support for presses, especially for RIM presses

description

The invention relates to a portable and self-sufficient carrier for presses, in particular for so-called RIM presses, which are plastic-processing machines which operate according to the reaction molding process (reaction injection molding).

A portable and self-sufficient carrier according to the preamble of claim 1 is known from the generic state of the art, WO 99/10155. This carrier has a RIM press and is suspended from a single-track rail system as a self-propelled carrier with several holding and guide rollers. A first frequency-controlled electric motor, which is arranged on the upper side of the carrier and which drives a roller which is in engagement with a rail, is used for locomotion along the rail system. To pivot the upper platen, it has a swivel joint on one side of the carrier and there are two further electric motors on the upper part of the carrier, the pinions of which engage in a rack that is curved in accordance with the pivoting radius of the upper platen. The upward and downward movement of the lower platen takes place along vertical guides on both sides of the carrier by means of spindles which are driven by a fourth electric motor attached to the upper carrier part. The closing pressure is built up with another fifth electric motor attached below the lower platen, with which the spindle nuts arranged in the lower area of the spindles are rotated via a worm gear and which move the previously rotationally blocked spindles upwards, whereby the lower platen firmly against the upper platen is pressed. By means of position sensors arranged on the spindles, the axial displacement of the spindles is kept within predetermined limits when the closing pressure is built up. After opening the RIM press the downward movement of the lower platen on one side can be done at a certain height by extending it at this height on the side Guides attached stop bolts can be stopped. These stop bolts are provided on the same side as the rotary fastening of the upper platen. The lower platen has a swivel on its side opposite the stop pin. As the downward movement continues, the lower platen rotates about this swivel joint. The Drehbzw. Swivel axes of the upper and lower platen are thus provided on different and opposite sides of the carrier.

Only a load power supply is required to move the carrier along the rails and to operate the RIM press. The disadvantages of hydraulically operated presses, as they are mentioned in this document, in particular the low energy efficiency, a high sound level when operating the hydraulic cylinders and the risk of leakages in the hydraulic fluid circuit are already eliminated with the purely electrical RIM press according to WO99 / 10155.

In contrast to the known rotary table arrangements of several RIM presses, the rail system according to WO99 / 10155 has the advantage that the upper mold half and the lower mold half of the press can be accessed by two operators simultaneously in the open state. Thus, for example, the finished part can be removed from the upper mold half on one side by a first operator, while on the other side a second operator cleans and reloads the lower mold half. This makes it possible to reduce the production cycle.

A first and essential disadvantage of the carrier according to W099 / 10155 is the lack of flexibility when pivoting the lower platen. Since the stop bolts are only attached to the side guides at a fixed height on one side, the lower platen can only be swiveled to one side. If the production of the plastic parts makes a swiveling movement to the opposite side meaningful or necessary, both the stop bolts and the swivel joint on the current side must be removed and reattached on the other side. Changing the swivel direction During a production cycle, it is not possible at all because of the fixed vertical position of the stop pins, the pivoting movement of the lower platen cannot be initiated at any time, although this can help to reduce the cycle time be pivoted when the mold exceeds a certain size, the pivoting movements of the upper and lower platen must be carried out sequentially if the stop bolts are not to be attached to another vertical position

Another disadvantage is the curved toothed racks projecting upwards into the space for pivoting the upper mold mounting plates.If the vertical dimensions of the support are to be made as small as possible, these toothed racks are annoying.One can also easily injure themselves on these protruding parts during maintenance work on the RIM press

The invention is therefore based on the object of making the carrier for RIM presses known from W099 / 10155 more flexible with regard to the accessibility of the lower mold mounting plate, independently of the tools to be used and independent of the pivoting movement of the upper mold mounting plate

This task is solved by a carrier with the features of claim 1. Advantageous refinements and developments are specified in subclaims 2 to 7. The main advantage of the mold carrier according to the invention lies in the high flexibility of the lower platen due to the central arrangement of the axis of rotation and the electromotive drive of the axis of rotation, the lower platen can be rotated or swiveled in almost any vertical position in two directions.Therefore, this mold carrier can be operated optimally according to the respective production process. Advantageously, at least one angle measuring device is provided according to subclaim 3, so that with the lower platen each within the maximum swivel positions Moved to any pivot position and thus the best access position for the respective work step can be achieved.

The design according to subclaims 4 and 5 eliminates the disadvantages of the curved rack projecting into the space according to the prior art.

With suitable means for determining the height position of the lower platen. With a linear absolute displacement measurement system, each vertical position of the lower platen can be approached as desired and the initiation of the pivoting movement of the lower platen can be initiated in any vertical position.

The carrier is self-sufficient, i.e. it can be operated in a monorail system, on a rotary table, on an oval or as a stationary mold carrier. The only form of energy supply from the outside is the electrical power supply. An outstanding advantage over the prior art is the user-friendliness and flexibility of the carrier, which is determined by the stepless, freely selectable tool mold position in terms of height and the angular positions of the lower tool mold carrier, i.e. of the lower platen.

The invention will be explained in more detail below with reference to FIGS. 1 and 2 in connection with a monorail system. Show it:

Fig.1 carrier in front view, on monorail system; Fig.2 Carrier in side view, on monorail system.

According to FIG. 1 and FIG. 2, a carrier 1 is fastened to the lower holding rail 2 of a self-driving trolley 3, which moves on a rail 4 by means of an electric motor 5 through the production line for the production of a plastic part according to the RIM method. Two hinges (mounting) 7 for the pivot axis 8 of the upper platen 9 are attached to the upper carrier part 6. 2 is the upper platen 9 shown once in the 0 ° position (swung-in state) and once in the 90 ° position (swung-out state). The upper platen is pivoted out via the electrically operated spindle motor 10. The spindle 1 1 of this electric motor 10 is articulated like the piston rod of a cylinder directly on the bell crank 12 of the upper platen. Depending on the selected direction of rotation of the spindle motor, the spindle is pivoted out or in about the hinge 7. A first advantage of this construction is that few mechanical parts are moved. The second advantage is that the construction is very low and therefore takes up little space. The swivel positions are queried via a first angle measuring device assigned to the upper platen, which is mounted directly on the swivel axis 8. The swivel holding positions can thus be freely selected and any angular position can be approached. The end positions of the upper platen are also queried via proximity switches. In the upper position (0 ° position), the pivoting movement of the upper platen 9 is blocked by two locking bolts 13. These locking bolts are actuated by an electric motor 14. Depending on the selected direction of rotation of the electric motor 14, the two locking bolts 13 move into the "locked" or "unlocked" positions. The locking bolts are connected to the axis of the electric motor 14 in a floating manner. The end positions of the locking bolts are queried via proximity switches.

The advantage of the electric motor-driven spindle motor is that it is self-locking in the event of a power failure.

The lower carrier part 15 consists of the lower platen 16 for receiving the lower mold half (not shown here) and the pressing unit 17 for applying the required closing force.

To close and open the mold, the lower platen 16 can be moved vertically, ie it can be raised and lowered. This movement is guided by laterally arranged roller guides 18 and 19 on both sides of the carrier 1. To drive the lower platen, there are two in the middle Spindles 20 and 21 are also provided on both sides of the carrier 1. These spindles 20 and 21 are mechanically coupled to one another via a chain drive 22 and are driven via a centrally arranged electric geared motor 23 with a brake. A linear absolute displacement measurement system is provided for measuring the distance and thus for detecting the vertical position of the lower platen, as a result of which the vertical travel positions can be freely adjusted. The linear movement is also self-locking; in the event of a chain or gear motor malfunction or in the event of a power failure, this does not lead to any uncontrolled movements. The minimum height of the lower platen to the hall floor can also be minimized and the overall height of the beam is comparatively low.

The closing force is applied via a plurality of evenly distributed air cushions 24, which ensure an even distribution of force. The compressed air required for this is fed from compressed air containers 25, which are supplied by a small electrical compressed air generator attached to the carrier. The movement when the clamping force is built up is limited and guided by four guide rods 26. Retraction springs 27 are constructed on the guide rods for applying the tear force and for quick venting.

The lower platen 16 is centered at both ends (28) and can be rotated about its own axis by + -30 °. This movement is driven and held by an electric gear motor 29 which is flanged to a bearing point. The pivot position is queried via a second angle measuring device 30, which is built directly on the axis. The swivel positions can be freely adjusted using the angle measuring system and it can be swiveled in both directions. The rotation is also self-locking; in the event of malfunction of the mechanical components or in the event of a power failure, this does not lead to uncontrolled movements. The lower platen is accessible from both sides and the access position, ie the swivel direction, can be selected and adjusted according to the respective requirements. The entire electrical control system, which essentially consists of a PLC control system and an integrated display unit, on which the current operating data, such as closing pressure, closing speed and swivel angle of the two, is located by means of soft key buttons, is located in a control cabinet 31 which is pivotably mounted on the support 1 Platen and the speed of the trolley can be adjusted. In addition, all safety-relevant control elements for the operation of a monorail system with several mold carriers 1 and several carriages 3 are already implemented in the control of each carrier, such as the emergency stop function, the hardware shutdown of the carriage and the carrier in the operating area or the external one Specification of three different driving speeds. Each carrier thus has its own intelligence and can therefore very easily be linked to existing RIM systems as a stationary unit, since it requires no other supply medium apart from a load power supply. Since all motion sequences realized on the carrier can be monitored and set by means of absolute value encoders, the adaptation to the most varied tool types and production sequences is very simple. The data exchange required for communication with a higher-level control system is implemented using an infrared-based data light barrier (infrared interface). In this way, an interface can be set up for, for example, tool number, carrier number, fault message, lock release, etc.

Portable and self-sufficient support for presses, especially for RIM presses

LIST OF REFERENCE NUMBERS

1 carrier

2 holding rails

3 carriages

4 rails

5 electric motor for the trolley

6 upper part of the beam

7 hinge

8 swivel axis for upper platen

9 Upper platen

10 Electric motor for spindle of the swiveling movement of the upper platen

11 Spindle for swiveling the upper platen

12 bellcranks

13 locking bolts

14 electric motor for locking bolts

15 lower beam

16 Lower platen

17 pressing unit

18 Lateral roller guide

19 Lateral roller guide

20 spindle

21 spindle

22 chain drive

23 electric motor for the spindles 20, 21 of the lifting movement

24 air cushions

25 compressed air tanks

26 guide rods

27 return springs Rotary mounting of the lower platen, electric motor for swiveling movement of the lower platen, angle measuring device, control cabinet

Claims

Portable and self-sufficient support for presses, especially for RIM presses

1. Portable and self-sufficient support for presses, in particular for RIM presses, with an upper mold mounting plate fastened to the upper support part, which can be pivoted by a horizontal axis by an electric motor, with vertical guides on two opposite sides of the support, with a lower guide that can be moved vertically along these guides by an electric motor and a mold clamping plate which can be pivoted about a horizontal axis, characterized in that the axis of rotation of the lower mold clamping plate is arranged in the center and an electric motor drive is provided for pivoting.

2. Carrier according to claim 1, characterized in that an electric gear motor is provided at one or at both ends of the horizontal axis of rotation of the lower platen.

3. Carrier according to claim 1 or 2, characterized in that at least one angle measuring device is provided on the axis of rotation of the lower platen.

4. Carrier according to one of claims 1 to 3, characterized in that for pivoting the upper platen one or more actuating lever with a linear drive are attached to the upper platen.

5. Carrier according to claim 4, characterized in that one or more electromotive spindles are provided as a linear drive, which are preferably arranged horizontally.

6. Carrier according to one of claims 1 to 5, characterized in that means are provided for determining the height position of the lower platen, in particular a linear absolute path measurement system.

7. Carrier according to one of claims 1 to 6, characterized in that means are provided for fastening the carrier to a self-propelled trolley of a monorail system.