DK146844B - HEATING MACHINE DRIVE - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a drive mechanism for hot forming machines having at least one upward and downwardly movable support beam for the molding tools and their auxiliary means, such as dies and ejectors, the turning movement of one or more motors in the drive mechanism by means of curve guide discs sensed swinging bar shaped guide arms are reacted for the upward and downward movement of the support beam and for the advance movement of the ribbon or plate-shaped material to be formed, and possibly also the material which has already been formed.

From the disclosures of United States Patent No. 3,172,159 and Swiss Patent No. 369,893, such driving mechanisms are known in which a central shaft with waveguide discs is located below the support beam (s). These waveguide · 15 discs interact directly with thrust bars that are firmly connected to the support beam. Both waveguide discs and thrust bars must therefore be solidly constructed and subjected to hard wear and high force effects. These known drive mechanisms further include separate drive mechanisms for advancing the material belt to be formed or already formed, the abrupt movement of the up and down carrier beam mechanism being unsuitable for advancing the material belt.

From the disclosure of U.S. Patent No. 3,647,335, there is also known a drive mechanism for hot forming machines, in which a shaft with a pair of cam discs, which is scanned by pivot weights, is arranged on the machine set next to the molding tools, the opposite ends of which the cam discs perform. a reciprocating movement which is transmitted 30 to above and below the carrier, knee joint presses are applied to close the molds.

However, with all of these known driving mechanisms, it is a disadvantage that the stroke of the movement transmitted directly or through the knee joint presses to the support beam is up and down, and is constant and thus cannot be adapted to the size of the molds. This stroke length must be large enough to be able to close molds with maximum depth, so the beams must always work with great stroke, even if the molds are not quite deep. Therefore, the driving power of these machines is unnecessarily high, and the speed of the up and down movement cannot be increased when working with molds of low depth. The large constant stroke also causes undesirable shocks in the machine operation, so that the drive mechanism cannot be coupled to the mechanisms for advancing the material belt, because the shocks can then cause deformations of the material belt, which, especially after the extrusion, are highly plastic moldable.

The invention has for its object to create a driving mechanism of the kind mentioned, by which the stroke length of the carrier can be adjusted as needed, ie. the stroke length of the molding tools, 20 just as the work rate must be adjustable, and a smooth operation of the drive mechanism must be achieved.

According to the invention, this is achieved by inserting an additional lever for adjusting the strut length, arranged below the support beam and formed as a two-bar lever, between the support beam and the curvature steering wheel scaffolding disc or its guide rod. the carrier connecting link bar, the distance from the linkage point of the linkage on the control arm to the latter's pivot axis and / or the distance from the linkage point of the linkage on the lifter to the latter's pivot axis.

Hereby the stroke of the up and down movement of the support beam can be easily adjusted according to the depth of the mold by adjusting the linkage with respect to the control arm or the lifter or both. At the same time, it becomes possible to achieve faster work rates by working with small-depth molds, either by changing the speed of the drive motors or by changing the exchange ratio between the motor and the drive mechanism. Furthermore, it has been found that in this way a quieter passage of the drive mechanism is obtained, as shock can be avoided by setting the stroke to an optimum value. Finally, this setting option reduces the total energy consumption of the drive mechanism over a longer period.

According to the invention, a simple way of adjusting the stroke can be achieved by having the handrail connected to the control arm and / or the lifter by means of eccentric pins.

Another possibility according to the invention is that the handrail is connected to the control arm and / or the lifter by means of an adjustable sliding block.

In this last embodiment, it is possible to adjust the stroke length of the supporting beam without changing the once-set closing position of the molding tools, according to the invention the sliding block can be adjustable in a circular arc-shaped sliding track, the center of which when the mechanism is in the rest position , lies at the joint point at the opposite end of the handrail. This greatly facilitates the adjustment of the molding tools.

A preferred embodiment according to the invention is characterized in that the waveguide disk consists of two waveguides 25 which are arranged to be driven together, the control arm for each waveguide disk having a follower, e.g. a follower roll, in that each of these followers is constantly in contact with the assigned wafer. This results in a much quieter operation of the drive mechanism, and the wear on both the wafer discs 30 and the follower rollers is greatly reduced, compared with the traditional construction with only one wafer disc and one follower roller.

Due to the quieter workflow of the drive mechanism, it can be utilized directly for stepwise advancement of an even very delicate material web coming directly from an extruder, the material web being progressively passed to the molding tools. Preferably, such a combined drive mechanism forms a separate unit connected only through the linkage to the hot forming machine, thereby avoiding the transfer of vibrations to the hot forming machine frame.

An embodiment of the invention will be described in the following with reference to the partly schematic drawing, in which fig. 1 is a side elevational and partial sectional drive mechanism according to the invention; FIG. 2 shows a slightly altered part of the mechanism of FIG. 1, in section, FIG. Fig. 3 is a part of the mechanism according to Fig. 1, showing the mechanism parts which carry and move the upper tool carrier beam; 4 is a view similar to line IV-IV of FIG. 3, FIG. 5 is a partial section of the area V-V in FIG. 4; FIG. 6 is a partial sectional view taken along line VI-VI of FIG. 4, FIG. 7 is a sectional view taken along line VII-VII of FIG. 6, FIG. 8 is a partial sectional view of the control curve and drive unit of FIG. 1, and FIG. 9 shows a further embodiment of the drive mechanism according to the invention, shown in the same way as in FIG. 2nd

As shown in FIG. 1, the drive mechanism comprises a control curve and drive unit 1 driven by an electric motor not shown. The control curve and drive unit 1 includes a control arm 2, which is designed as a pivot bar and engages with control curves 5 within the unit, a sprocket 3 associated with internal drive means for transmitting an intermittent drive and feed movement, respectively, and a sprocket 4 for transmitting a continuous feed or drive movement, respectively.

5 In accordance with the simplified drawing of the drawing, the actual hot forming machine includes a lower, vertically upward and downwardly movable support beam 5 for molding tools and auxiliary means, respectively, and an upper, possibly also vertically upward and downwardly moving support beam 6 for molding tools and auxiliary means, respectively. Both support beams 5 and 6 are vertically slidably mounted on columns 7, which are mounted on the machine frame 8. Between the control curves and drive unit 1's control curves and the lower support beam 5, possibly also the upper support. rope bar 6, there is inserted a timing device adapted to the timing, which, in addition to the aforementioned control arm 2, includes a lifter 9, which is arranged under the support beam 5 and a guide rod 10, which connects the control arm 2 with the lifter 9, and a lifting rod 11 connecting the lifter 9 to the support beam 5, and optionally 20 a lifting rod 12 (cf. Fig. 3) connecting the lifter 9 to the upper support beam 6.

By means of eccentric pins 13 and 14, the handrail 10 is articulated with the guide arm 2 and the lifter 9. respectively. 2, the arm length a of the portion of the control arm 2 acting on the linkage arm 10 can be changed by adjusting the eccentric pin 13, and the arm length b of the part of the lifter 9 affected by the linkage arm 10 can be changed by adjusting the eccentric pin 14. If the arm length a of the control arm 2 is set to the maximum value and the arm length 30 b of the lifter 9 to the minimum value, then a maximum stroke is obtained for the support beam 5 and 6. However, a minimum stroke length for the support beam 5 and 6, respectively, is obtained if the center arm 13 of the control arm 2 is set to the minimum arm length a. 9's eccentric pin 35 14 at maximum arm length b. Between maximum and minimum stroke length, intermediate stroke lengths can be continuously adjusted. By appropriate selection of the eccentricity of the eccentric pins relative to the minimum values for the arm lengths a and b, an appropriate size of the stroke length setting range can be obtained. In the present example, it should be possible to set between a maximum and a minimum stroke in the ratio of 1: 1.5.

As FIG. 2 shows, the guide disc 15, which produces the stroke movement, is formed by two wafer discs 16 and 17. On each of these wafer discs, a follower roll 18 and 19 respectively run on the guide arm 2, which are pivotally mounted in two by means of pins 20 10 the control curve and drive unit 1's frame. The position of the follower rolls 18 and 19 on the guide arm 2 and the shape of the washers 16 and 17 are so mutually coordinated that the two follower rolls are in continuous contact with the respective curve disc 16 or 17. As soon as one follower roll 18 runs down a downpour 16a on curve guide 16, the second follower roll 19 runs up an upright portion 17a of the curve disc 17. Conversely, the follower roll 19 runs down a down portion 17b of the curve disc 17 as the follower owl 18 runs up an upright portion 16b of the curve disk 16. During this course, the control arm 2 -20 about its pivot 20 a forced pivotal movement, which in each phase is controlled by the two curve discs 16 and 17. The pivotal movements of the control arm 21 are transmitted through the eccentric pin 13 to the handrail 10, whose movement again through the eccentric pin 14 is converted to a pivotal movement of the lifter 9. 9's pivotal movement 9 is again transmitted by means of the lifting rod 11 to the lower support beam 5, and optionally by means of a pair of lifting rods 12 t. In the upper support beam 6. The guide disc 15 is continuously rotated by means of the electric motor, while the lifting and lowering movements of the supporting beams 5 and 6 are solely determined by the waveforms of the curved discs 16 and 17. The operating rate of the support beams 5 and 6 can be varied by means of a continuously variable reduction gear inserted between the drive motor and the control disc 15, or by adjusting the speed of the drive motor. In order to achieve a self-locking effect on the closed mold tool, it is convenient to place both the lifting shaft 21 and the lifting link 11's linkage points 22 and 23 and the lifting shaft 21 and the lifting link 12's linking points 24 and 25 in the same plane when the molding tool is in the closing tool. -

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1 position. To achieve this, the handrail 10 is longitudinally adjustable so that at any setting of the eccentric pins 13 and 14 it is possible to adjust the desired self-locking position of the various parts by a closed molding tool. To adjust the position of the support beam 5 only when the mold is closed, the lifting link 11 is also adjustable for length. Also, if desired, the lifting link 12 may be length adjustable.

In order to prevent shocks from moving upwardly 10 and downwardly of the support beam 5 and the molded parts or auxiliary means placed thereon, which are transmitted rearwardly to the control curve and drive unit and disturb the smooth running of the machine and its drive device, a weight equalization mechanism is provided. which is arranged to engage under the support beam 5 and 15 is provided with at least one force accumulating element. This weight equalization mechanism contains in the embodiment shown in FIG. 1 shows four compressed air cylinders 26 arranged for engagement under the four corner areas of the lower support beam 5 and whose pressure sides are connected in parallel to a compressed air container 27.

The air pressure of this container can be set to a desired value by means of a regulator 28 which measures the pressure in the container 27 and regulates the inlet and outflow of compressed air thereon.

Along with the pressurized compressed air container 27, the compressed air cylinders 26 form a force accumulator which, similar to 25 the set pressure in the container 27, counteracts the downward movement of the beam 5 and supports its upward movement to prevent the occurrence of harmful shocks. As shown in FIG. 2, the weight equalization mechanism may also be equipped with hydraulic cylinders 29 which are connected to an airbag 30 operating hydraulic reservoir 30. The hydraulic reservoir 30 is again provided with a regulator 28 for adjusting the pressure of the airbag. In the example of FIG. 4, only two hydraulic cylinders 29 are disposed diagonally below the lower support beam 5. Similarly to the example of FIG. 1, however, four such hydraulic cylinders could also be arranged 29. However, it is also conceivable that only a single pneumatic or hydraulic cylinder may be used, which could then be located below the center area of the lower support beam. As will be seen from FIG. 1 and 2, the piston rods 26 and 29 respectively of the pneumatic or hydraulic cylinders 26 are placed in contact only with the underside of the lower support beam 5. It is therefore possible to allow the forming machine to operate without the weight equalizing mechanism 5 simply by removing the pressure in the compressed air container. 27 and the hydraulic vessel 30. The pressure in the compressed air vessel 27 and the hydraulic vessel 30, respectively, can also be adjusted so low that some braking or damping effect is caused by the downward movement of the support beam 5, but the movement produced by the control disk 15 the carrier 5 becomes faster than the upward movement of the piston rods of cylinders 26 and 29, respectively, so that the upward movement of the carrier 5 for closure of the mold is not affected by the compressed air cylinders 26 and hydraulic cylinders 29. By means of a compressed-air nozzle valve, the driving means work practically weightless, ie that at a constant pressure against the pistons of cylinders 26 or 29, the same force is always produced at the same weight.

In the example shown in the drawing, the hot forming machine 20 is provided with a lower upward and downwardly movable support beam 5 and an upper upward and downwardly movable support beam 6. The invention is also of principle important for such machines having only a single upward and downwardly moving supporting beam and optionally one against this fixed carrier yoke. The example shown, however, constitutes a universally applicable hot forming machine having an upward and downwardly movable lower support 5, and an upper support 6 which may optionally be positioned stationary or adapted to be operated for upward and downward movement in reception with the lower support beam 5. For this purpose 30, for the mechanical connection between the lifter 9 and the upper support beam 6, the lift shaft 21 is provided with at least one crank 31 and a related concentric shaft pin 32 which can be axially recessed in the shaft 21. The lifting rod 12 can, with its lower eye 33, be optionally applied to the crank 31 35 or to the concentric shaft pin 32. If the lifting rod 12 is inserted on the crank 31, it goes without saying that the concentric shaft pin 32 must be recessed in the end surface of the shaft 21. As shown in FIG. 3, the placement of link points 22 and 24 with respect to shaft 21 causes the upper carrier 6 to move upwards and downwards in receptacle with the lower carrier 5. The stroke of the upper carrier 6 and downward movement must then be determined in relation to the stroke of the lower carrier 5 by appropriately selecting the distances from the link points 22 and 24 from the shaft 21. By extension, the stroke of the upper carrier 6T can be varied with the stroke of the lower carrier 5. described above.

10 If the lifting link 12 with its lower eye 33 is applied to the concentric shaft 32 after it has been pulled out from its recessed position in the shaft 21, at the rotation of the shaft 21, the shaft pin 32 will only rotate inside the eye 33 and the upper support beam 6 is stationary. .

As the upper support beam 6 is moved in receptacle with the lower support beam 5, the weight to be equalized becomes substantially smaller, so that in FIG. 3 hydraulic cylinder 30 (or a compressed air reservoir 27 present in FIG. 1) can be set at a substantially lower air pressure than in the case where the machine is stationary with the upper support 6 standing still.

FIG. 4-7 show details of the lifter 9. According to these, the lifter 9 has a lifter shaft 21 on which the individual lifter parts are attached. The lifter shaft 21 is mounted in bearings 35 in two bearing brackets 34, which are attached to a stable cross beam 36. The lifting shaft 21 carries a first lifting arm 37 which is mechanically connected to the control arm 2 by means of a support frame 21. of the bar 10.

Near the first lifting arm 27, a pair of additional lifting arms 38 are secured to the shaft 21 30, between which the lifting link 11 is mounted with a lower eye. If desired, two or more pairs of additional lifting arms 38 may be used. At each end of the lifting shaft 21, a crank arm 39 is provided with each crank 31 and associated concentric shaft 32.

35 In the left part of FIG. 4, the lifting rod 12 with its lower eye 33 is inserted on the crank 31, while the right of FIG. 4, the lifting rod 12 with its lower eye 33 is inserted on the concentric shaft pin 32 and the crank 31 runs freely.

As shown in FIG. 5, the crank 31 is inserted into the crank arm 39 at the end 5 and retained therein by clamping the slotted portion. The crank arm 39 is inserted at the end of the lift shaft 2 and secured to it by, for example, a groove 40. At each end of the lift shaft 21, it has an end bore 41 in which the concentric shaft pin 32 10 is inserted. The concentric shaft pin 32 can be retained in the extended or retracted position by means of a locking screw 43 which cooperates with ring grooves 42a and 42b on the shaft pin 32.

In addition, the concentric shaft pin 32 is provided with a threaded hole 44 formed at the end face, in which a suitable tool can be screwed in to pull the shaft pin 32 out through the end bore 41 and optionally also for inserting the shaft pin 32 into the end bore 41. The thread hole 44 can further be used for screwing a securing disc onto the end surface of the shaft pin 32 when the lower eye of the lifting rod 12 is inserted on the shaft pin 32.

FIG. 6 and 7 show the design of the first lifting arm 37 which is inserted on the lifting shaft 21 and is secured to it, e.g. by means of a notch wedge 45. The first lifting arm 25 37 is slit at the free end where it receives an eccentric foot 46. The eccentric pin 14 is formed eccentrically on the eccentric foot 46 located in the first lifting arm. at the end, the eccentric foot 46 is formed with two or three through holes 47 for receiving a tool, and with a radially projecting stop nose 48a. On the first lifting arm 37, stops are arranged to cooperate with the stop nose 48a, namely a stop 48b for the maximum position (smallest arm) and a stop 48c for the minimum position (largest arm), or stop pins with which the maximum and minimum positions can be adjusted. When the eccentric pin 14 is to be adjusted, the clamping screws 49 are loosened on one of the first lifting arms 37, after which the eccentric foot 46 can be turned to the desired position by means of suitable tools.

As shown in FIG. 8, the control curve and drive unit 1 comprise a synchronous with the drive control disk 15 driven feed control disk 50, which in turn drives the sprocket 3, which carries the belt conveyor 52's (see Fig. 9) drive chain 51. The feed wheel disk 50 is constructed of a pair of feed curve discs 50a and 50b. Each of the feed curve washers 10 50a and 50b has a cam 53 which is similar in shape but is directed towards each other. A follower 55, which sits on the same shaft as the sprocket 3, runs by means of two pairs of followers, preferably follower rollers 54, on the feed curve discs 50a and 50b. The follower rollers 54 are arranged so that at any one time 15 the one follower roll 54 runs in each pair on the surface of one of the feed curve discs. As soon as the feed curve disc in question with its cam 53 runs against the follower roller 54 with which it is currently cooperating, the follower disk 55 is rotated until the cam 53 of both feed curve 20 discs have passed past the follower rollers 50a and 50b running up to now 54, and the lugs 53 thereby lifting this pair of guide rollers and placing the second pair of guide rollers 54 on the circumferential surfaces of the feed curve discs 50a and 50b. This turns the follower 55 55 180 °. The second pair's follower rolls 54 then run on the circumferential faces of the feed curve discs 50a and 50b until the cams again reach their area. Until then, no further rotation of the follower disk 55 occurs. Only when the lugs 53 again pass the follower rollers 54 does 30 again a 180 ° turn of the follower disk 55. In the synchronous operation of the feed guide disc 50 with the impact control disc 15, in this way, the material web is always conveyed when the mold is open, ie. the supporting beams 5 and 6 (see Fig. 2) are moved away from each other and the molding tool 35 is thereby placed in an open position so that the mold bodies can pass.

FIG. 9 shows a hot forming machine in a somewhat modified configuration, based on the embodiment shown in FIG. 2. For the parts described in connection with FIG. 2 and which have not changed, the same reference numerals as in FIG. 2. The machine of FIG. 9 differs from that of FIG. 2 shows at 5 the following differences: 1. As can be seen from FIG. 9, the adjustment of the stroke is not made by means of those shown in FIG. 2, but by means of a slide block 13a inserted in the control arm 2, while the eccentric pin 14 is replaced by a normal bearing pin 14a. The stroke length adjustment of the sliding block 13a connected to the link rod 10 is effected by means of the spindle 13b. The use of the sliding block 13a inserted in the control arm 2 offers the advantage that both a larger setting range and a quick and stepless adjustment of stroke 15 are obtained. In the embodiment shown in FIG. 9, the sliding groove 13c extends along a circular arc around the axis of the bearing pin 14a, whereby the resting position of the lifter 9 remains unaffected by any adjustment of the sliding block 13a in the sliding groove 13c.

2. In the example of FIG. 9, the upper tool carrier 6a 20 is formed with several e.g. three, overlaid bores 25a, so that the articulation point 12 of the linkage rod 12 can be adjusted according to tool tops 90 of different height. (In Fig. 9, as an example of tool top 90, a clamping frame is indicated.) 25. 9 shows a double-acting, preferably pneumatic pressure cylinders 80 in place of the lower tool carrier and support beam 5, respectively, instead of the usual ones, in FIG. 2 ejector springs not shown. Such ejector springs are disadvantageous for several reasons; they require a lot of space in the tools, it is difficult to determine their torque, their power is not adjustable and they need to be replaced when using another tool. Relative to these springs, the pressure cylinders 80, such as throw-off or stripping cylinders, offer the advantage of requiring less space as they are located outside the tool and can be adjusted to the required torque at any time. In addition, the pressure cylinders must only be incorporated into the machine once, and by using double-acting cylinders, the piston rod 81 can also be used as a forced-acting ejector. All working parts, which have been placed in the tool so far using springs, are located after the incorporation of the pressure cylinders into the machine itself, thereby providing a simplification of the tools. Furthermore, the cylinder or cylinders can be assigned different tasks. Thus, e.g. two cylinders in conjunction with adjustable stops 84 for movement of the stripper plate 82 by means of connecting rods 83 are used as coercive ejectors, while one or two additional cylinders may be used for the design of double bottoms or for two-stage ejection, such as 15 it is indicated by the connecting plate 85 in the lower part of the molding tool 86.

The 9, three changes are not dependent on each other. They can be used individually or together and in any embodiment of the invention.

Claims (9)

A drive mechanism for hot forming machines having at least one upward and downwardly movable support beam (5,6) for the molding tools and their auxiliary means, such as matrices and ejectors, the turning movement of one or more motors in the drive mechanism by means of curve guide discs (15) be guided by the guide arms (2) designed as pivotal bars, translate upwardly and downwardly of the support beam (5,6) and to the advance movement of the ribbon or plate-shaped material to be formed, and possibly also the material which has already been formed shaped, characterized in that an additional, for adjusting the stroke length of the carrier, is inserted between the support beam (5,6) and the pivot steering wheel (15) sensing control arm (15) or its guide rod (10), adapted for adjusting the stroke length of the support beam ( 5, 15 6) lifts (9) and a lifter (9) and the supporting beam (5,6) connecting lever (11,12), arranged as a two-armed lever, the distance from the linkage coupling of the linkage (10) nct on the control arm (2) of the latter's pivot axis (20) and / or the distance from the link point of the lever (10) on the lifter (9) to the latter's pivot axis (21) is adjustable. Drive mechanism according to claim 1, characterized in that the handrail (10) is connected to the control arm (2) and / or the lifter (9) by means of eccentric pins (13 and 14, respectively). Drive mechanism according to claim 1, characterized in that the linkage rod (10) is connected to the control arm (2) and / or the lifter (9) by means of an adjustable slide block (13a). Drive mechanism according to claim 3, characterized in that the sliding block (13a) is adjustable in a circular arcuate sliding groove (13c), the center of which, when the mechanism is in the resting position, lies at the articulation point at the opposite end of the linkage (10). 15 146844 Drive mechanism according to claim 4, characterized in that the sliding block (13a) sits on a screw spindle (13b) which extends substantially along the sliding groove (13c) and is pivotally mounted at one end of the sliding groove (13c). Drive mechanism according to one of claims 1-5, characterized in that the waveguide disk (15) consists of two waveguides (16,17) arranged to be driven together, the control arm (2) for each waveguide (16,17). ) has a follower, e.g. a follower roll (18 and 19, respectively), with each of these followers being in continuous contact with the assigned wafer (16 and 17, respectively). Drive mechanism according to one of claims 1-6, and having a lower support beam (5) and an upper support beam (6), characterized in that both support beams (5,6) are mechanically connected to the lifter (9). the mechanical connection between the upper support beam (6) and the lifter (9) being arranged to be switchable between movement of the upper support beam (6) in reception with the lower support beam (5) and stationary state of the upper support beam (6). ). Drive mechanism according to claim 7, characterized in that the shaft (21) carrying the lifter (9) has at least one crank (31) with a corresponding shaft (32) extending in the shaft (21), at least one, preferably two lifting rods (12) is arranged to support the upper 25 support beam (6) and each with an eye (33) arranged at the lower end is adapted to be inserted on either the crank (31) or the said shaft pin (32). Drive mechanism according to one of claims 1-8, characterized in that the lifter (9) consists of a first lifting arm 30 (37), which is secured to the lifting shaft (21) and through the link rod (10) is mechanically connected to the control arm (2), as well as two or more additional lifting arms (38), which are also attached to the lifting shaft (21) and through each of its lifting links (11) are mechanically connected to the carrier (5).