EP0190241B1 - Device for adjusting the milling gap in roll mills - Google Patents

Abstract

A grinding clearance adjustment device for milling roller frames is disclosed, in which a casing contains two grinding rollers, one of which is constructed as a pivotable loose roller. Adjustment members, for the rollers are provided, as well as a device for the automatic setting of the grinding clearance by means of a remotely controllable drive motor, the latter being coupled to the adjustment members via transmission means. The motor operates through a clutch. In the preferred embodiment, the adjustment members are constructed as a first closed standard component, which has a lever-transmitted setting part with a longer and a shorter lever arm and which is laterally positioned in the vicinity of the grinding rollers. The drive motor and clutch are constructed as a second closed standard component, which is spaced from the first standard component, and the adjustment forces derived from the drive motor are coupled to the longer lever arm of setting part. In addition, the adjustment members are provided with a manual setting means which can be utilized simultaneously with the automatic, motor adjustment.

Description

The invention relates to a grinding gap adjustment device for milling roller mills with a housing arranged in: a) two grinding rollers, one of which is designed as a pivotable loose roller; b) arranged laterally to the grinding rollers and acting on these adjusting elements for setting the grinding gap to a desired value and c) actuating devices coupled to the adjusting elements with c.1) a remotely controllable drive motor for automatic grinding gap adjustment and c.2) manual adjustment.

• Tritt ein grösserer Fremdkörper, etwa eine Schraube, in den Mahlspalt ein, so muss der auftretende Druckschlag sofort aufgefangen werden, was üblicherweise mit einer mechanischen Überlastsicherung für das Walzenpaar vorgenommen wird.

In the case of grinding gap adjustment devices for milling roll mills, three special operating states must be taken into special consideration:

• If a larger foreign body, such as a screw, enters the grinding gap, the pressure shock that occurs must be absorbed immediately, which is usually done with mechanical overload protection for the pair of rollers.

Secondly, in the absence of regrind (especially if there are corrugated rollers), the grinding rollers must automatically move into an apart position, since otherwise the two grinding rollers would rub against each other due to their different speeds and would damage each other.

Ultimately, the distance between the grinding rollers (“grinding gap”) must also be adjustable with great accuracy for the normal grinding area.

Experience to date has shown that a mechanical grinding gap setting device is superior to other, for example corresponding hydraulic setting devices, for setting the grinding gap. The grinding gap adjustment of a mill roller mill, as simple as the adjustment process is in and of itself, is altogether a quite complex process, as can be seen from the explanations from European Patent No. 13023. So it was until today z. B. not yet possible to determine in a satisfactory manner clear parameters (such as the grinding pressure or the motor power consumption) that would be suitable as suitable output parameters for the automatic setting of the grinding rollers or for the control of the grinding gap (roller spacing) according to the respective requirements. For economic reasons, it was also necessary to keep the number of influencing parameters that are required and determinable for regulation quite limited. Every automatic regulation carries out the control and regulation processes without direct insight from the outside and normally excludes manual intervention. If a mill system is to be optimally managed, humans still have an important share in the system management for all unpredictable disturbance variables that can have completely different causes. If there is a need for both automatic control and manual intervention, then very complex overall facilities have to be accepted.

Proceeding from this, the object of the invention is to find a particularly favorable solution for a combined automatic and manual adjustment of the adjustment device of a milling roller mill.

According to the invention, this is achieved in a device of the type mentioned at the outset in that d) the adjusting members form their own, first closed structural unit which d.1) has a lever-translated adjusting part with a longer and a shorter lever arm and d.2) has the manual setting; e) the drive motor is designed as a separate, second, connectable (29) structural unit; f) the second unit is mounted at a distance from the first unit; and g) attack the adjustment forces derived from the drive motor via overdrive means on the longer lever arm.

Previous solutions for automatically operated milling roller mills always assumed that, from a constructive point of view, the automatic should also give priority to devices for manual intervention.Accordingly, in the case of previously known solutions, a gear motor was usually connected directly to pulling elements for adjusting the grinding rollers (cf. 6 of European Patent No. 13023). In contrast, the solution of the present invention summarizes the traditional setting means as a separate, closed assembly, the path taken in accordance with the invention very quickly proving to be extremely expedient and surprisingly having many practical advantages. The solution according to the invention shows that the use of a previous manual setting by an automatic does not have to lead to a new type of grinding, for example by the rollers being “softer” or “harder”, etc. Rather, the stability of the setting of the Maintain grinding rollers.

The device according to the invention thus represents an addition to a rolling mill, which can be attached at any time later, for example if only a part of the roller mills of a mill is to be provided with an automatic system. Since a mill roller mill for the type of operation (processing floury goods) has previously been a very compact machine, the inventive arrangement of a second assembly at a distance from the pair of grinding rollers does not make it difficult to access the other elements. If necessary, the roller mill can even be operated without automatic control by manual adjustment of the adjustment elements.

In a very advantageous embodiment of the invention, the clutch is designed as an adjustable slip clutch, which is an elegant way an automatic grinding roller adjustment device according to predetermined setpoints, eg. B, the distance between the grinding rollers. The setting can be made here on the basis of a predetermined program or setpoint scheme Since faults are inevitable in practice, the slip clutch limits incorrect intervention. This can also prevent z. B. the grinding gap or pressure unintentionally set to undesirably high values and the rolling mill or the roller bearings could be destroyed.

It proves to be very convenient and advantageous if a first structural unit is provided on each of the bearing end sides of the grinding rollers, a second structural unit common to both bearing end sides, and furthermore means for automatic parallel adjustment of the loose roller, the first structural unit being a slip-free overdrive by the second Unit is controllable. This makes it possible to carry out a particularly simple retrofitting on roller mills that are already in operation, which also allows all existing milling roller mills to retain the larger economic values embodied in them and to be able to retrofit the roller mills for further automation without the need to purchase new roller mills.

A further advantageous embodiment of the invention with regard to ease of use also consists in the fact that the drive motor drives an adjusting spindle through the overdrive means, for example a chain, which is formed on the longer lever arm of the adjusting part, which is particularly preferably more than 3 times as long as the shorter lever arm is, attacks and on which a hand adjusting wheel is attached, which is preferably provided with a display device in the form of a display clock. The hand adjusting wheel is preferably provided with a display device or a position indicator, which in turn is preferably designed in the form of a display clock, which can be integrated directly in the handwheel as a dial gauge. In this way, the handwheel is carried accordingly for each automatic correction and the respective status is displayed on the handwheel. It is also particularly advantageous if the second structural unit is arranged in the region of the foot of the roller mill.

A further advantageous embodiment of the grinding gap adjustment device according to the invention also consists in that a position detector is provided which can be controlled by the overdrive means or by the adjustment elements. Preferably, such a position indicator, for. B. use a potentiometer. Particularly advantageously, the overdrive means transmit the adjusting force through a slipless overdrive, the position indicator being coupled directly via a chain either to the slipless overdrive or to the driven side of the clutch. A toothed belt or a chain or similar devices, which simultaneously move the position indicator, can preferably be used as a slip-free overdrive.

The position indicator, which is preferably connected to a suitable position indicator, allows the exact position of both grinding rollers to be displayed and reported back at any time, especially if the position indicator on the output side of the clutch, i. H. in direct positive connection with the adjusting elements. For practical operation, it has proven to be particularly expedient if a digital display and manual input keys are attached to the housing of the roller mill to control the drive motor by the operator for the position indicator. This enables the operator responsible, for example the head miller, to appropriately control the drive motor when the desired roller position values have been reached.

Another advantageous embodiment of the grinding gap adjustment device according to the invention further consists in that a digital display and manual input keys are attached to the housing of the roller mill to control the drive motor; a program-controlled computer is preferably also used for remote control of the drive motor, to which, in turn, preferably, a common computer connected upstream of the computers of a plurality of roller mills is connected in the sense of a superordinate order. In certain cases, however, it can also be of great advantage if a preliminary circuit is not provided here, but rather a common computer with one or more setpoint memories is assigned to a plurality of roller mills. The aforementioned measures can be used to directly control all roller mills according to predetermined setpoint value schemes, that is to say an actual control process.

In addition to the control process, the grinding gap adjustment device can also be part of an actual control device, the grinding result or the grain fineness resulting from the grinding gap width being selected as the size to be controlled and controlled according to the grinding gap.

At the input of said computer, preferably the output signals of a grinding pressure measuring device assigned to the grinding rollers and / or a pressure limit switch can be applied, optionally either a pressure limit switch and / or a position limit switch for overload protection for such accidents caused by faulty control commands for the setting of the Grinding gap can be triggered, can be used. The output signals of a power demand measuring device assigned to the grinding rollers and / or a power consumption limit switch are preferably applied to the input of the computer. Likewise, preferably, the output signals of a roller distance measuring device assigned to the grinding rollers and / or of a distance limit switch can also be applied to the input of the computer.

It is also advantageous if a safety element that can be set to selectable limit values for grinding pressure or power requirement or roller spacing is used both for the motor cal as well as for the manual setting device is effectively provided.

• Fig. 1 eine erfindungsgemässe Mahlspalteinstellvorrichtung eines Müllereiwalzwerkes mit motorischen Verstellmitteln;
• Fig. 2 eine schematische Vorderansicht eines Walzenstuhles gemäss Fig. 1, die beidseitig sowohl motorische wie Handeinstsellungen aufweist;
• Fig. 3 eine andere Ausführungsform zu der in Fig. 2 gezeigten, jedoch mit beidseitiger Handeinstellung und nur einem motorischen Antrieb für eine Parallelverstellung der Mahlwalzen sowie
• Fig. 4 eine schematische Darstellung der motorischen Verstell- wie auch Rechnermittel (Computer) einer erfindungsgemässen Mahlspaltverstellvorrichtung.

The invention is explained in more detail below in principle by way of example with reference to the drawing. Show it:

• 1 shows a grinding gap setting device according to the invention of a milling mill with motorized adjusting means;
• FIG. 2 shows a schematic front view of a roller mill according to FIG. 1, which has both motor and manual settings on both sides;
• Fig. 3 shows another embodiment of the one shown in Fig. 2, but with manual adjustment on both sides and only one motor drive for parallel adjustment of the grinding rollers and
• Fig. 4 is a schematic representation of the motorized adjustment and computer means (computer) of a grinding gap adjustment device according to the invention.

1 shows a mill roller mill with adjusting members as a first assembly 1 and with a controllable adjustment drive as a second assembly 2. Two grinding rollers 41 and 42 are supported on a common carrier 3. The idler roller 42 is pivotally attached to a stationary eccentric bolt 4, the engagement and disengagement being controlled by a lever 5 and a disengagement cylinder 6. Due to the pivoting movement of the lever 5, the eccentric pin 4 is rotated and causes a horizontal displacement of the lower part of the pivotable bearing housing 7, so that the distance between the two grinding rollers can be roughly adjusted. However, this device would be too imprecise for an exact setting; it is therefore only used to bring the grinding rollers 41, 42 into an engaged or disengaged position or into two fixed positions. The actual fine adjustment takes place via an adjusting spindle 8, which directly rotates an adjusting arm 9 about a fixed pivot bearing 10. The upper, shorter lever arm 9 "of the adjusting arm 9 is non-positively connected to the pivotable bearing housing 7 via a pull rod 11. The power transmission takes place via cutting edges, which are part of an overload spring lock 12 on one side. The pull rod 11 is on the opposite side an adjustable counter switch button 13 and a pressure measuring device 14 with pressure display device 15. In order to be able to adjust the grinding rollers in parallel during service work, a correction can be made on the respectively required side by means of adjusting screws 43, 44. The adjusting spindle 8 is held in place by bearings 10 'and can now be operated via a handwheel 16, which has a directly installed display clock 17 (FIG. 2), or via motor means, namely an overdrive chain 18 and a gear motor or drive motor 19. The drive motor 19 is fastened to the roller mill 26 and stands over a slip clutch 20 and a Kettenra d 21 in direct connection with the overdrive chain 18 or the adjusting spindle 8.

The adjusting motor 19 and the slip clutch 20 could also be located at any other suitable location, e.g. B. outside on the rolling mill. However, the free inner space of the stand base proves to be the most suitable place for the placement of the adjustment drive with a view to optimizing the overall conditions. Any suitable slip clutch can be used as the slip clutch 20, which can transmit minimum torques and can release the positive connection by slipping at a certain preselectable torque or can no longer transmit the adjusting force of the motor means beyond a certain torque. The minimum torque should, however, only be selected so large that it can be overcome with the handwheel 16 and a grinding gap setting can be effected by hand without turning the geared motor 19.

A position indicator 22 is also directly connected to the exaggeration chain 18 via a chain 23 and a sprocket 24, as a result of which every movement of the exaggeration chain 18 is registered in the position indicator 22 and forwarded to the desired locations. As can be seen from FIGS. 1 and 2, very few individual elements are required for the motorized adjusting means. The largest element, the drive motor 19 and the clutch 20, can preferably be arranged in the area of a lower free recess in the roller mill stand 26, so that the second assembly 2 or the automatic grinding gap setting can also be retrofitted at any time to correspondingly constructed older milling roller mills. With a suitable design, the assembly can also be designed in the form of a closed structural unit, so that subsequent installation is also facilitated and accelerated in this respect. Since mill roller mills are generally built in a double version, this is indicated in FIG. 1 with a dash-dotted center line 27. Each pair of rollers of the two halves of the roller mill can be equipped with or without such automatic adjustment means.

In the embodiment shown in FIG. 2, an assembly 1 and 2 is arranged on each end of the bearing. A handwheel 16 with an integrated display clock 17 is also shown as a possibility on both sides. Both sides of the bearing each have a drive motor 19, a position indicator 22 and an overdrive chain 18. The roller distance can thus be controlled on both sides of the bearing by the motor 19 and the chain 18 or set by the operator via the handwheel 16. Instead of the display clock 17, a digital display 45 and manual input keys 46 could also be used. It would also be conceivable that the handwheel 16 and the manual input keys 45 are provided at the same time for a certain start-up period in order to familiarize the operating personnel. It is also possible for the digital display 45 or the display clock 17 to be used alone or in each case use both at the same time, which can be an advantage in certain applications.

FIG. 3 shows an alternative to the embodiment according to FIG. 2. Only the handwheel 16 and the display clock 17 are provided for an individual correction on the left and right or twice. In a further simplification, only one handwheel 16 can be used instead of the handwheel on the left and right. A necessary correction on one side can be carried out using nuts 43, 44 (FIG. 1), so that only a handwheel 16 with a display clock 17 is required, for example for larger mills with a very rare change in the product mixture or with always the same end products. The setting of the grinding gap is also carried out in FIG. 3 via a drive motor 19, the adjustment path being transmitted to the other bearing side in each case via a chain 39 or 40. A parallel adjustment of the grinding rollers is carried out in this way via the corresponding automatic.

The illustration in FIG. 1 shows a drive 28 for the grinding rollers 41 and 42 (only in dash-dotted lines). It is also possible to provide an electrical power demand measurement and display device 29 in the drive system. So z. B. the electrical power consumption is limited to lower and upper values and if the preselected range is exceeded z. B. disengagement of the grinding rollers can be caused.

Another possibility for this is given by determining the effective distance between bearing housing parts using a roller distance measuring and display device 30 (cf. FIG. 1). Especially when using corrugated rolls, the roll gap monitoring can reliably prevent incorrect commands that would lead to mechanical destruction of at least parts of the rolling mill.

Such a device is shown again schematically in FIG. 4, supplemented with further control links. 4, all signals of a roller mill are coordinated and controlled by a computer 31, which can call up the required setpoints from a central computer 32 with memory 33. The position indicator 22 in the illustration according to FIG. 4 is also equipped with a position limit switch 34 which can be set to the desired limit values in order to thereby prevent incorrect setting by the automatic system. In the position shown, the position limit switch 34 has the advantage that incorrect manual adjustment can also be prevented, since the handwheel and automatic adjustment result in a corresponding displacement of the overdrive chain 18 and the chain 23. The position indicator 22, like the adjustment motor 19, can be connected to an input / output device 35 which receives or emits corresponding signals from the computer 31, corresponding to the digital display 45 and the manual input keys 46 in FIG. 2. In the same sense, the pressure measurement can - And display device 14, 15 are connected to the computer 31. Depending on the level of expansion of a rolling mill, one or more collateral can be provided on the same rolling mill. Are z. If, for example, corrugated rollers are installed, monitoring the grinding pressure is less sensible, but monitoring the distance between the grinding rollers via the position indicator 22 or a distance meter 36. Conversely, the situation is with smooth rollers, in which pressure monitoring brings greater advantages. A computer 37 and the signal lines 38 are intended to indicate in FIG. 4 that the computer 32 with its memory 33 can control a plurality, possibly even all, of the roller mills in a mill and, if necessary, coordinate control functions.

It has proven to be particularly advantageous if the digital display outputs 45 display values in the same way of displaying the values as the display of the handwheel, for example values according to a time display on a clock (e.g. the handwheel is at 3:30 p.m., the digital display shows to: 15.30). A great advantage is also shown in the fact that the empirical values of non-automated or non-remotely controllable roller mills are compared and can be used to set up or improve corresponding control programs.

Claims (10)

1. Nip adjusting apparatus for roll mills having the following arranged in a casing:

a) two milling rolls (41, 42), of which one is designed as a pivotal idling roll (42);

b) adjusting members (7-9, 11), arranged at the sides of the milling rolls (41, 42) and engaging them, for setting the nip to a desired value and

c) operating devices coupled to the adjusting members (7-9, 11) with

c.1) a remote-controllable drive motor (19) for automatic nip setting and

c.2) a manual setting (8, 16), characterized in that

d) the adjusting members (7-9, 11) form an independent first self-contained unit (1) which has

d.1) a lever-transmission setting part (9) with a longer lever arm (9') and a shorter lever arm (9") and

d.2) the manual setting (8, 16),

e) the drive motor (19) is designed as an independent second self-contained unit (2) capable of being coupled (20)

f) the second unit (2) is fitted at a distance from the first unit (1) and

g) the adjusting forces diverted from the drive motor (19) act via means of transmission (18; 39) on the longer lever arm (9').

2. Nip adjusting apparatus according to claim 1, characterized in that the coupling (20) is designed as a sliding coupling which can be set.

3. Nip adjusting apparatus according to claim 1 or 2, characterized in that the drive motor (19) drives, by the means of transmission, a spindle (8), which acts on the longer lever arm (9') of the setting part (9) and is fitted to the manual adjusting wheel (16), which is preferably provided with a display device (17) in the form of a display clock.

4. Nip adjusting apparatus according to one of claims 1 to 3, characterized in that the second unit (2) is arranged in the region of the foot of the roll mill.

5. Nip adjusting apparatus according to one of claims 1 to 4, characterized in that there are arranged on both bearing end sides of the milling rolls (41, 42) a first unit (1) each and a second unit (2) each.

6. Nip adjusting apparatus according to one of claims 1 to 3, characterized in that there are provided on both bearing end sides of the milling rolls (41, 42) a first unit (1) each, furthermore a second unit (2) provided jointly for both bearing end sides, and also means (39, 40) for automatic parallel adjustment of the idling roll (42), the first unit (1) being capable of being driven via a non-slipping transmission (39) by the second unit (2).

7. Nip adjusting apparatus according to one of claims 1 to 5, characterized in that the means of transmission (39) act without slipping and a position indicator (22) is coupled directly via a chain (23) either to the non-slipping transmission (39) or to the output side of the coupling (20).

8. Nip adjusting apparatus according to claim 7, characterized in that a digital display (45) and manual input keys (46) are fitted on the casing of the roll mill (26) for controlling the drive motor (19).

9. Nip adjusting apparatus according to one of claims 1 to 8, characterized in that a program- controlled computer (31) is provided for remote control of the drive motor (19), via which computer the drive motors of several roll mills can be controlled simultaneously.

10. Nip adjusting apparatus according to claim 9, characterized in that the output signals of a roll distance measuring instrument (30) and/or of a distance limit switch assigned to the milling rolls (41, 42) are passed to the input of the computer (31).

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